Merge branch 'for-2.6.28' of git://git.kernel.dk/linux-2.6-block

* 'for-2.6.28' of git://git.kernel.dk/linux-2.6-block: (132 commits)
  doc/cdrom: Trvial documentation error, file not present
  block_dev: fix kernel-doc in new functions
  block: add some comments around the bio read-write flags
  block: mark bio_split_pool static
  block: Find bio sector offset given idx and offset
  block: gendisk integrity wrapper
  block: Switch blk_integrity_compare from bdev to gendisk
  block: Fix double put in blk_integrity_unregister
  block: Introduce integrity data ownership flag
  block: revert part of d7533ad0e132f92e75c1b2eb7c26387b25a583c1
  bio.h: Remove unused conditional code
  block: remove end_{queued|dequeued}_request()
  block: change elevator to use __blk_end_request()
  gdrom: change to use __blk_end_request()
  memstick: change to use __blk_end_request()
  virtio_blk: change to use __blk_end_request()
  blktrace: use BLKTRACE_BDEV_SIZE as the name size for setup structure
  block: add lld busy state exporting interface
  block: Fix blk_start_queueing() to not kick a stopped queue
  include blktrace_api.h in headers_install
  ...

124 files changed, 3838 insertions, 2637 deletions

diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt
index d8b63d164e4..b8e86460046 100644
--- a/Documentation/DMA-API.txt
+++ b/Documentation/DMA-API.txt
@@ -337,7 +337,7 @@ With scatterlists, you use the resulting mapping like this:
 	int i, count = dma_map_sg(dev, sglist, nents, direction);
 	struct scatterlist *sg;
 
-	for (i = 0, sg = sglist; i < count; i++, sg++) {
+	for_each_sg(sglist, sg, count, i) {
 		hw_address[i] = sg_dma_address(sg);
 		hw_len[i] = sg_dma_len(sg);
 	}
diff --git a/Documentation/DocBook/kernel-api.tmpl b/Documentation/DocBook/kernel-api.tmpl
index b7b1482f6e0..f5696ba9ae9 100644
--- a/Documentation/DocBook/kernel-api.tmpl
+++ b/Documentation/DocBook/kernel-api.tmpl
@@ -364,6 +364,10 @@ X!Edrivers/pnp/system.c
 !Eblock/blk-barrier.c
 !Eblock/blk-tag.c
 !Iblock/blk-tag.c
+!Eblock/blk-integrity.c
+!Iblock/blktrace.c
+!Iblock/genhd.c
+!Eblock/genhd.c
   </chapter>
 
   <chapter id="chrdev">
diff --git a/Documentation/block/deadline-iosched.txt b/Documentation/block/deadline-iosched.txt
index c23cab13c3d..72576769e0f 100644
--- a/Documentation/block/deadline-iosched.txt
+++ b/Documentation/block/deadline-iosched.txt
@@ -30,12 +30,18 @@ write_expire	(in ms)
 Similar to read_expire mentioned above, but for writes.
 
 
-fifo_batch
+fifo_batch	(number of requests)
 ----------
 
-When a read request expires its deadline, we must move some requests from
-the sorted io scheduler list to the block device dispatch queue. fifo_batch
-controls how many requests we move.
+Requests are grouped into ``batches'' of a particular data direction (read or
+write) which are serviced in increasing sector order.  To limit extra seeking,
+deadline expiries are only checked between batches.  fifo_batch controls the
+maximum number of requests per batch.
+
+This parameter tunes the balance between per-request latency and aggregate
+throughput.  When low latency is the primary concern, smaller is better (where
+a value of 1 yields first-come first-served behaviour).  Increasing fifo_batch
+generally improves throughput, at the cost of latency variation.
 
 
 writes_starved	(number of dispatches)
diff --git a/Documentation/cdrom/ide-cd b/Documentation/cdrom/ide-cd
index 91c0dcc6fa5..2c558cd6c1e 100644
--- a/Documentation/cdrom/ide-cd
+++ b/Documentation/cdrom/ide-cd
@@ -145,8 +145,7 @@ useful for reading photocds.
 
 To play an audio CD, you should first unmount and remove any data
 CDROM.  Any of the CDROM player programs should then work (workman,
-workbone, cdplayer, etc.).  Lacking anything else, you could use the
-cdtester program in Documentation/cdrom/sbpcd.
+workbone, cdplayer, etc.).
 
 On a few drives, you can read digital audio directly using a program
 such as cdda2wav.  The only types of drive which I've heard support
diff --git a/block/Makefile b/block/Makefile
index 208000b0750..bfe73049f93 100644
--- a/block/Makefile
+++ b/block/Makefile
@@ -4,8 +4,8 @@
 
 obj-$(CONFIG_BLOCK) := elevator.o blk-core.o blk-tag.o blk-sysfs.o \
 			blk-barrier.o blk-settings.o blk-ioc.o blk-map.o \
-			blk-exec.o blk-merge.o ioctl.o genhd.o scsi_ioctl.o \
-			cmd-filter.o
+			blk-exec.o blk-merge.o blk-softirq.o blk-timeout.o \
+			ioctl.o genhd.o scsi_ioctl.o cmd-filter.o
 
 obj-$(CONFIG_BLK_DEV_BSG)	+= bsg.o
 obj-$(CONFIG_IOSCHED_NOOP)	+= noop-iosched.o
diff --git a/block/as-iosched.c b/block/as-iosched.c
index cf4eb0eefbb..71f0abb219e 100644
--- a/block/as-iosched.c
+++ b/block/as-iosched.c
@@ -462,7 +462,7 @@ static void as_antic_stop(struct as_data *ad)
 			del_timer(&ad->antic_timer);
 		ad->antic_status = ANTIC_FINISHED;
 		/* see as_work_handler */
-		kblockd_schedule_work(&ad->antic_work);
+		kblockd_schedule_work(ad->q, &ad->antic_work);
 	}
 }
 
@@ -483,7 +483,7 @@ static void as_antic_timeout(unsigned long data)
 		aic = ad->io_context->aic;
 
 		ad->antic_status = ANTIC_FINISHED;
-		kblockd_schedule_work(&ad->antic_work);
+		kblockd_schedule_work(q, &ad->antic_work);
 
 		if (aic->ttime_samples == 0) {
 			/* process anticipated on has exited or timed out*/
@@ -745,6 +745,14 @@ static int as_can_break_anticipation(struct as_data *ad, struct request *rq)
  */
 static int as_can_anticipate(struct as_data *ad, struct request *rq)
 {
+#if 0 /* disable for now, we need to check tag level as well */
+	/*
+	 * SSD device without seek penalty, disable idling
+	 */
+	if (blk_queue_nonrot(ad->q)) axman
+		return 0;
+#endif
+
 	if (!ad->io_context)
 		/*
 		 * Last request submitted was a write
@@ -844,7 +852,7 @@ static void as_completed_request(struct request_queue *q, struct request *rq)
 	if (ad->changed_batch && ad->nr_dispatched == 1) {
 		ad->current_batch_expires = jiffies +
 					ad->batch_expire[ad->batch_data_dir];
-		kblockd_schedule_work(&ad->antic_work);
+		kblockd_schedule_work(q, &ad->antic_work);
 		ad->changed_batch = 0;
 
 		if (ad->batch_data_dir == REQ_SYNC)
diff --git a/block/blk-barrier.c b/block/blk-barrier.c
index a09ead19f9c..5c99ff8d2db 100644
--- a/block/blk-barrier.c
+++ b/block/blk-barrier.c
@@ -293,7 +293,7 @@ int blkdev_issue_flush(struct block_device *bdev, sector_t *error_sector)
 	bio->bi_end_io = bio_end_empty_barrier;
 	bio->bi_private = &wait;
 	bio->bi_bdev = bdev;
-	submit_bio(1 << BIO_RW_BARRIER, bio);
+	submit_bio(WRITE_BARRIER, bio);
 
 	wait_for_completion(&wait);
 
@@ -315,3 +315,73 @@ int blkdev_issue_flush(struct block_device *bdev, sector_t *error_sector)
 	return ret;
 }
 EXPORT_SYMBOL(blkdev_issue_flush);
+
+static void blkdev_discard_end_io(struct bio *bio, int err)
+{
+	if (err) {
+		if (err == -EOPNOTSUPP)
+			set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
+		clear_bit(BIO_UPTODATE, &bio->bi_flags);
+	}
+
+	bio_put(bio);
+}
+
+/**
+ * blkdev_issue_discard - queue a discard
+ * @bdev:	blockdev to issue discard for
+ * @sector:	start sector
+ * @nr_sects:	number of sectors to discard
+ * @gfp_mask:	memory allocation flags (for bio_alloc)
+ *
+ * Description:
+ *    Issue a discard request for the sectors in question. Does not wait.
+ */
+int blkdev_issue_discard(struct block_device *bdev,
+			 sector_t sector, sector_t nr_sects, gfp_t gfp_mask)
+{
+	struct request_queue *q;
+	struct bio *bio;
+	int ret = 0;
+
+	if (bdev->bd_disk == NULL)
+		return -ENXIO;
+
+	q = bdev_get_queue(bdev);
+	if (!q)
+		return -ENXIO;
+
+	if (!q->prepare_discard_fn)
+		return -EOPNOTSUPP;
+
+	while (nr_sects && !ret) {
+		bio = bio_alloc(gfp_mask, 0);
+		if (!bio)
+			return -ENOMEM;
+
+		bio->bi_end_io = blkdev_discard_end_io;
+		bio->bi_bdev = bdev;
+
+		bio->bi_sector = sector;
+
+		if (nr_sects > q->max_hw_sectors) {
+			bio->bi_size = q->max_hw_sectors << 9;
+			nr_sects -= q->max_hw_sectors;
+			sector += q->max_hw_sectors;
+		} else {
+			bio->bi_size = nr_sects << 9;
+			nr_sects = 0;
+		}
+		bio_get(bio);
+		submit_bio(DISCARD_BARRIER, bio);
+
+		/* Check if it failed immediately */
+		if (bio_flagged(bio, BIO_EOPNOTSUPP))
+			ret = -EOPNOTSUPP;
+		else if (!bio_flagged(bio, BIO_UPTODATE))
+			ret = -EIO;
+		bio_put(bio);
+	}
+	return ret;
+}
+EXPORT_SYMBOL(blkdev_issue_discard);
diff --git a/block/blk-core.c b/block/blk-core.c
index 2cba5ef97b2..2d053b58441 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -26,8 +26,6 @@
 #include <linux/swap.h>
 #include <linux/writeback.h>
 #include <linux/task_io_accounting_ops.h>
-#include <linux/interrupt.h>
-#include <linux/cpu.h>
 #include <linux/blktrace_api.h>
 #include <linux/fault-inject.h>
 
@@ -50,27 +48,26 @@ struct kmem_cache *blk_requestq_cachep;
  */
 static struct workqueue_struct *kblockd_workqueue;
 
-static DEFINE_PER_CPU(struct list_head, blk_cpu_done);
-
 static void drive_stat_acct(struct request *rq, int new_io)
 {
 	struct hd_struct *part;
 	int rw = rq_data_dir(rq);
+	int cpu;
 
 	if (!blk_fs_request(rq) || !rq->rq_disk)
 		return;
 
-	part = get_part(rq->rq_disk, rq->sector);
+	cpu = part_stat_lock();
+	part = disk_map_sector_rcu(rq->rq_disk, rq->sector);
+
 	if (!new_io)
-		__all_stat_inc(rq->rq_disk, part, merges[rw], rq->sector);
+		part_stat_inc(cpu, part, merges[rw]);
 	else {
-		disk_round_stats(rq->rq_disk);
-		rq->rq_disk->in_flight++;
-		if (part) {
-			part_round_stats(part);
-			part->in_flight++;
-		}
+		part_round_stats(cpu, part);
+		part_inc_in_flight(part);
 	}
+
+	part_stat_unlock();
 }
 
 void blk_queue_congestion_threshold(struct request_queue *q)
@@ -113,7 +110,8 @@ void blk_rq_init(struct request_queue *q, struct request *rq)
 	memset(rq, 0, sizeof(*rq));
 
 	INIT_LIST_HEAD(&rq->queuelist);
-	INIT_LIST_HEAD(&rq->donelist);
+	INIT_LIST_HEAD(&rq->timeout_list);
+	rq->cpu = -1;
 	rq->q = q;
 	rq->sector = rq->hard_sector = (sector_t) -1;
 	INIT_HLIST_NODE(&rq->hash);
@@ -308,7 +306,7 @@ void blk_unplug_timeout(unsigned long data)
 	blk_add_trace_pdu_int(q, BLK_TA_UNPLUG_TIMER, NULL,
 				q->rq.count[READ] + q->rq.count[WRITE]);
 
-	kblockd_schedule_work(&q->unplug_work);
+	kblockd_schedule_work(q, &q->unplug_work);
 }
 
 void blk_unplug(struct request_queue *q)
@@ -325,6 +323,21 @@ void blk_unplug(struct request_queue *q)
 }
 EXPORT_SYMBOL(blk_unplug);
 
+static void blk_invoke_request_fn(struct request_queue *q)
+{
+	/*
+	 * one level of recursion is ok and is much faster than kicking
+	 * the unplug handling
+	 */
+	if (!queue_flag_test_and_set(QUEUE_FLAG_REENTER, q)) {
+		q->request_fn(q);
+		queue_flag_clear(QUEUE_FLAG_REENTER, q);
+	} else {
+		queue_flag_set(QUEUE_FLAG_PLUGGED, q);
+		kblockd_schedule_work(q, &q->unplug_work);
+	}
+}
+
 /**
  * blk_start_queue - restart a previously stopped queue
  * @q:    The &struct request_queue in question
@@ -339,18 +352,7 @@ void blk_start_queue(struct request_queue *q)
 	WARN_ON(!irqs_disabled());
 
 	queue_flag_clear(QUEUE_FLAG_STOPPED, q);
-
-	/*
-	 * one level of recursion is ok and is much faster than kicking
-	 * the unplug handling
-	 */
-	if (!queue_flag_test_and_set(QUEUE_FLAG_REENTER, q)) {
-		q->request_fn(q);
-		queue_flag_clear(QUEUE_FLAG_REENTER, q);
-	} else {
-		blk_plug_device(q);
-		kblockd_schedule_work(&q->unplug_work);
-	}
+	blk_invoke_request_fn(q);
 }
 EXPORT_SYMBOL(blk_start_queue);
 
@@ -408,15 +410,8 @@ void __blk_run_queue(struct request_queue *q)
 	 * Only recurse once to avoid overrunning the stack, let the unplug
 	 * handling reinvoke the handler shortly if we already got there.
 	 */
-	if (!elv_queue_empty(q)) {
-		if (!queue_flag_test_and_set(QUEUE_FLAG_REENTER, q)) {
-			q->request_fn(q);
-			queue_flag_clear(QUEUE_FLAG_REENTER, q);
-		} else {
-			blk_plug_device(q);
-			kblockd_schedule_work(&q->unplug_work);
-		}
-	}
+	if (!elv_queue_empty(q))
+		blk_invoke_request_fn(q);
 }
 EXPORT_SYMBOL(__blk_run_queue);
 
@@ -441,6 +436,14 @@ void blk_put_queue(struct request_queue *q)
 
 void blk_cleanup_queue(struct request_queue *q)
 {
+	/*
+	 * We know we have process context here, so we can be a little
+	 * cautious and ensure that pending block actions on this device
+	 * are done before moving on. Going into this function, we should
+	 * not have processes doing IO to this device.
+	 */
+	blk_sync_queue(q);
+
 	mutex_lock(&q->sysfs_lock);
 	queue_flag_set_unlocked(QUEUE_FLAG_DEAD, q);
 	mutex_unlock(&q->sysfs_lock);
@@ -496,6 +499,8 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
 	}
 
 	init_timer(&q->unplug_timer);
+	setup_timer(&q->timeout, blk_rq_timed_out_timer, (unsigned long) q);
+	INIT_LIST_HEAD(&q->timeout_list);
 
 	kobject_init(&q->kobj, &blk_queue_ktype);
 
@@ -531,7 +536,7 @@ EXPORT_SYMBOL(blk_alloc_queue_node);
  *    request queue; this lock will be taken also from interrupt context, so irq
  *    disabling is needed for it.
  *
- *    Function returns a pointer to the initialized request queue, or NULL if
+ *    Function returns a pointer to the initialized request queue, or %NULL if
  *    it didn't succeed.
  *
  * Note:
@@ -569,7 +574,8 @@ blk_init_queue_node(request_fn_proc *rfn, spinlock_t *lock, int node_id)
 	q->request_fn		= rfn;
 	q->prep_rq_fn		= NULL;
 	q->unplug_fn		= generic_unplug_device;
-	q->queue_flags		= (1 << QUEUE_FLAG_CLUSTER);
+	q->queue_flags		= (1 << QUEUE_FLAG_CLUSTER |
+				   1 << QUEUE_FLAG_STACKABLE);
 	q->queue_lock		= lock;
 
 	blk_queue_segment_boundary(q, 0xffffffff);
@@ -624,10 +630,6 @@ blk_alloc_request(struct request_queue *q, int rw, int priv, gfp_t gfp_mask)
 
 	blk_rq_init(q, rq);
 
-	/*
-	 * first three bits are identical in rq->cmd_flags and bio->bi_rw,
-	 * see bio.h and blkdev.h
-	 */
 	rq->cmd_flags = rw | REQ_ALLOCED;
 
 	if (priv) {
@@ -888,9 +890,11 @@ EXPORT_SYMBOL(blk_get_request);
  */
 void blk_start_queueing(struct request_queue *q)
 {
-	if (!blk_queue_plugged(q))
+	if (!blk_queue_plugged(q)) {
+		if (unlikely(blk_queue_stopped(q)))
+			return;
 		q->request_fn(q);
-	else
+	} else
 		__generic_unplug_device(q);
 }
 EXPORT_SYMBOL(blk_start_queueing);
@@ -907,6 +911,8 @@ EXPORT_SYMBOL(blk_start_queueing);
  */
 void blk_requeue_request(struct request_queue *q, struct request *rq)
 {
+	blk_delete_timer(rq);
+	blk_clear_rq_complete(rq);
 	blk_add_trace_rq(q, rq, BLK_TA_REQUEUE);
 
 	if (blk_rq_tagged(rq))
@@ -917,7 +923,7 @@ void blk_requeue_request(struct request_queue *q, struct request *rq)
 EXPORT_SYMBOL(blk_requeue_request);
 
 /**
- * blk_insert_request - insert a special request in to a request queue
+ * blk_insert_request - insert a special request into a request queue
  * @q:		request queue where request should be inserted
  * @rq:		request to be inserted
  * @at_head:	insert request at head or tail of queue
@@ -927,8 +933,8 @@ EXPORT_SYMBOL(blk_requeue_request);
  *    Many block devices need to execute commands asynchronously, so they don't
  *    block the whole kernel from preemption during request execution.  This is
  *    accomplished normally by inserting aritficial requests tagged as
- *    REQ_SPECIAL in to the corresponding request queue, and letting them be
- *    scheduled for actual execution by the request queue.
+ *    REQ_TYPE_SPECIAL in to the corresponding request queue, and letting them
+ *    be scheduled for actual execution by the request queue.
  *
  *    We have the option of inserting the head or the tail of the queue.
  *    Typically we use the tail for new ioctls and so forth.  We use the head
@@ -982,8 +988,22 @@ static inline void add_request(struct request_queue *q, struct request *req)
 	__elv_add_request(q, req, ELEVATOR_INSERT_SORT, 0);
 }
 
-/*
- * disk_round_stats()	- Round off the performance stats on a struct
+static void part_round_stats_single(int cpu, struct hd_struct *part,
+				    unsigned long now)
+{
+	if (now == part->stamp)
+		return;
+
+	if (part->in_flight) {
+		__part_stat_add(cpu, part, time_in_queue,
+				part->in_flight * (now - part->stamp));
+		__part_stat_add(cpu, part, io_ticks, (now - part->stamp));
+	}
+	part->stamp = now;
+}
+
+/**
+ * part_round_stats()	- Round off the performance stats on a struct
  * disk_stats.
  *
  * The average IO queue length and utilisation statistics are maintained
@@ -997,36 +1017,15 @@ static inline void add_request(struct request_queue *q, struct request *req)
  * /proc/diskstats.  This accounts immediately for all queue usage up to
  * the current jiffies and restarts the counters again.
  */
-void disk_round_stats(struct gendisk *disk)
+void part_round_stats(int cpu, struct hd_struct *part)
 {
 	unsigned long now = jiffies;
 
-	if (now == disk->stamp)
-		return;
-
-	if (disk->in_flight) {
-		__disk_stat_add(disk, time_in_queue,
-				disk->in_flight * (now - disk->stamp));
-		__disk_stat_add(disk, io_ticks, (now - disk->stamp));
-	}
-	disk->stamp = now;
-}
-EXPORT_SYMBOL_GPL(disk_round_stats);
-
-void part_round_stats(struct hd_struct *part)
-{
-	unsigned long now = jiffies;
-
-	if (now == part->stamp)
-		return;
-
-	if (part->in_flight) {
-		__part_stat_add(part, time_in_queue,
-				part->in_flight * (now - part->stamp));
-		__part_stat_add(part, io_ticks, (now - part->stamp));
-	}
-	part->stamp = now;
+	if (part->partno)
+		part_round_stats_single(cpu, &part_to_disk(part)->part0, now);
+	part_round_stats_single(cpu, part, now);
 }
+EXPORT_SYMBOL_GPL(part_round_stats);
 
 /*
  * queue lock must be held
@@ -1070,6 +1069,7 @@ EXPORT_SYMBOL(blk_put_request);
 
 void init_request_from_bio(struct request *req, struct bio *bio)
 {
+	req->cpu = bio->bi_comp_cpu;
 	req->cmd_type = REQ_TYPE_FS;
 
 	/*
@@ -1081,7 +1081,12 @@ void init_request_from_bio(struct request *req, struct bio *bio)
 	/*
 	 * REQ_BARRIER implies no merging, but lets make it explicit
 	 */
-	if (unlikely(bio_barrier(bio)))
+	if (unlikely(bio_discard(bio))) {
+		req->cmd_flags |= REQ_DISCARD;
+		if (bio_barrier(bio))
+			req->cmd_flags |= REQ_SOFTBARRIER;
+		req->q->prepare_discard_fn(req->q, req);
+	} else if (unlikely(bio_barrier(bio)))
 		req->cmd_flags |= (REQ_HARDBARRIER | REQ_NOMERGE);
 
 	if (bio_sync(bio))
@@ -1099,7 +1104,7 @@ void init_request_from_bio(struct request *req, struct bio *bio)
 static int __make_request(struct request_queue *q, struct bio *bio)
 {
 	struct request *req;
-	int el_ret, nr_sectors, barrier, err;
+	int el_ret, nr_sectors, barrier, discard, err;
 	const unsigned short prio = bio_prio(bio);
 	const int sync = bio_sync(bio);
 	int rw_flags;
@@ -1114,7 +1119,14 @@ static int __make_request(struct request_queue *q, struct bio *bio)
 	blk_queue_bounce(q, &bio);
 
 	barrier = bio_barrier(bio);
-	if (unlikely(barrier) && (q->next_ordered == QUEUE_ORDERED_NONE)) {
+	if (unlikely(barrier) && bio_has_data(bio) &&
+	    (q->next_ordered == QUEUE_ORDERED_NONE)) {
+		err = -EOPNOTSUPP;
+		goto end_io;
+	}
+
+	discard = bio_discard(bio);
+	if (unlikely(discard) && !q->prepare_discard_fn) {
 		err = -EOPNOTSUPP;
 		goto end_io;
 	}
@@ -1138,6 +1150,8 @@ static int __make_request(struct request_queue *q, struct bio *bio)
 		req->biotail = bio;
 		req->nr_sectors = req->hard_nr_sectors += nr_sectors;
 		req->ioprio = ioprio_best(req->ioprio, prio);
+		if (!blk_rq_cpu_valid(req))
+			req->cpu = bio->bi_comp_cpu;
 		drive_stat_acct(req, 0);
 		if (!attempt_back_merge(q, req))
 			elv_merged_request(q, req, el_ret);
@@ -1165,6 +1179,8 @@ static int __make_request(struct request_queue *q, struct bio *bio)
 		req->sector = req->hard_sector = bio->bi_sector;
 		req->nr_sectors = req->hard_nr_sectors += nr_sectors;
 		req->ioprio = ioprio_best(req->ioprio, prio);
+		if (!blk_rq_cpu_valid(req))
+			req->cpu = bio->bi_comp_cpu;
 		drive_stat_acct(req, 0);
 		if (!attempt_front_merge(q, req))
 			elv_merged_request(q, req, el_ret);
@@ -1200,13 +1216,15 @@ get_rq:
 	init_request_from_bio(req, bio);
 
 	spin_lock_irq(q->queue_lock);
+	if (test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags) ||
+	    bio_flagged(bio, BIO_CPU_AFFINE))
+		req->cpu = blk_cpu_to_group(smp_processor_id());
 	if (elv_queue_empty(q))
 		blk_plug_device(q);
 	add_request(q, req);
 out:
 	if (sync)
 		__generic_unplug_device(q);
-
 	spin_unlock_irq(q->queue_lock);
 	return 0;
 
@@ -1260,8 +1278,9 @@ __setup("fail_make_request=", setup_fail_make_request);
 
 static int should_fail_request(struct bio *bio)
 {
-	if ((bio->bi_bdev->bd_disk->flags & GENHD_FL_FAIL) ||
-	    (bio->bi_bdev->bd_part && bio->bi_bdev->bd_part->make_it_fail))
+	struct hd_struct *part = bio->bi_bdev->bd_part;
+
+	if (part_to_disk(part)->part0.make_it_fail || part->make_it_fail)
 		return should_fail(&fail_make_request, bio->bi_size);
 
 	return 0;
@@ -1314,7 +1333,7 @@ static inline int bio_check_eod(struct bio *bio, unsigned int nr_sectors)
 }
 
 /**
- * generic_make_request: hand a buffer to its device driver for I/O
+ * generic_make_request - hand a buffer to its device driver for I/O
  * @bio:  The bio describing the location in memory and on the device.
  *
  * generic_make_request() is used to make I/O requests of block
@@ -1409,7 +1428,8 @@ end_io:
 
 		if (bio_check_eod(bio, nr_sectors))
 			goto end_io;
-		if (bio_empty_barrier(bio) && !q->prepare_flush_fn) {
+		if ((bio_empty_barrier(bio) && !q->prepare_flush_fn) ||
+		    (bio_discard(bio) && !q->prepare_discard_fn)) {
 			err = -EOPNOTSUPP;
 			goto end_io;
 		}
@@ -1471,13 +1491,13 @@ void generic_make_request(struct bio *bio)
 EXPORT_SYMBOL(generic_make_request);
 
 /**
- * submit_bio: submit a bio to the block device layer for I/O
+ * submit_bio - submit a bio to the block device layer for I/O
  * @rw: whether to %READ or %WRITE, or maybe to %READA (read ahead)
  * @bio: The &struct bio which describes the I/O
  *
  * submit_bio() is very similar in purpose to generic_make_request(), and
  * uses that function to do most of the work. Both are fairly rough
- * interfaces, @bio must be presetup and ready for I/O.
+ * interfaces; @bio must be presetup and ready for I/O.
  *
  */
 void submit_bio(int rw, struct bio *bio)
@@ -1490,11 +1510,7 @@ void submit_bio(int rw, struct bio *bio)
 	 * If it's a regular read/write or a barrier with data attached,
 	 * go through the normal accounting stuff before submission.
 	 */
-	if (!bio_empty_barrier(bio)) {
-
-		BIO_BUG_ON(!bio->bi_size);
-		BIO_BUG_ON(!bio->bi_io_vec);
-
+	if (bio_has_data(bio)) {
 		if (rw & WRITE) {
 			count_vm_events(PGPGOUT, count);
 		} else {
@@ -1517,9 +1533,90 @@ void submit_bio(int rw, struct bio *bio)
 EXPORT_SYMBOL(submit_bio);
 
 /**
+ * blk_rq_check_limits - Helper function to check a request for the queue limit
+ * @q:  the queue
+ * @rq: the request being checked
+ *
+ * Description:
+ *    @rq may have been made based on weaker limitations of upper-level queues
+ *    in request stacking drivers, and it may violate the limitation of @q.
+ *    Since the block layer and the underlying device driver trust @rq
+ *    after it is inserted to @q, it should be checked against @q before
+ *    the insertion using this generic function.
+ *
+ *    This function should also be useful for request stacking drivers
+ *    in some cases below, so export this fuction.
+ *    Request stacking drivers like request-based dm may change the queue
+ *    limits while requests are in the queue (e.g. dm's table swapping).
+ *    Such request stacking drivers should check those requests agaist
+ *    the new queue limits again when they dispatch those requests,
+ *    although such checkings are also done against the old queue limits
+ *    when submitting requests.
+ */
+int blk_rq_check_limits(struct request_queue *q, struct request *rq)
+{
+	if (rq->nr_sectors > q->max_sectors ||
+	    rq->data_len > q->max_hw_sectors << 9) {
+		printk(KERN_ERR "%s: over max size limit.\n", __func__);
+		return -EIO;
+	}
+
+	/*
+	 * queue's settings related to segment counting like q->bounce_pfn
+	 * may differ from that of other stacking queues.
+	 * Recalculate it to check the request correctly on this queue's
+	 * limitation.
+	 */
+	blk_recalc_rq_segments(rq);
+	if (rq->nr_phys_segments > q->max_phys_segments ||
+	    rq->nr_phys_segments > q->max_hw_segments) {
+		printk(KERN_ERR "%s: over max segments limit.\n", __func__);
+		return -EIO;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(blk_rq_check_limits);
+
+/**
+ * blk_insert_cloned_request - Helper for stacking drivers to submit a request
+ * @q:  the queue to submit the request
+ * @rq: the request being queued
+ */
+int blk_insert_cloned_request(struct request_queue *q, struct request *rq)
+{
+	unsigned long flags;
+
+	if (blk_rq_check_limits(q, rq))
+		return -EIO;
+
+#ifdef CONFIG_FAIL_MAKE_REQUEST
+	if (rq->rq_disk && rq->rq_disk->part0.make_it_fail &&
+	    should_fail(&fail_make_request, blk_rq_bytes(rq)))
+		return -EIO;
+#endif
+
+	spin_lock_irqsave(q->queue_lock, flags);
+
+	/*
+	 * Submitting request must be dequeued before calling this function
+	 * because it will be linked to another request_queue
+	 */
+	BUG_ON(blk_queued_rq(rq));
+
+	drive_stat_acct(rq, 1);
+	__elv_add_request(q, rq, ELEVATOR_INSERT_BACK, 0);
+
+	spin_unlock_irqrestore(q->queue_lock, flags);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(blk_insert_cloned_request);
+
+/**
  * __end_that_request_first - end I/O on a request
  * @req:      the request being processed
- * @error:    0 for success, < 0 for error
+ * @error:    %0 for success, < %0 for error
  * @nr_bytes: number of bytes to complete
  *
  * Description:
@@ -1527,8 +1624,8 @@ EXPORT_SYMBOL(submit_bio);
  *     for the next range of segments (if any) in the cluster.
  *
  * Return:
- *     0 - we are done with this request, call end_that_request_last()
- *     1 - still buffers pending for this request
+ *     %0 - we are done with this request, call end_that_request_last()
+ *     %1 - still buffers pending for this request
  **/
 static int __end_that_request_first(struct request *req, int error,
 				    int nr_bytes)
@@ -1539,7 +1636,7 @@ static int __end_that_request_first(struct request *req, int error,
 	blk_add_trace_rq(req->q, req, BLK_TA_COMPLETE);
 
 	/*
-	 * for a REQ_BLOCK_PC request, we want to carry any eventual
+	 * for a REQ_TYPE_BLOCK_PC request, we want to carry any eventual
 	 * sense key with us all the way through
 	 */
 	if (!blk_pc_request(req))
@@ -1552,11 +1649,14 @@ static int __end_that_request_first(struct request *req, int error,
 	}
 
 	if (blk_fs_request(req) && req->rq_disk) {
-		struct hd_struct *part = get_part(req->rq_disk, req->sector);
 		const int rw = rq_data_dir(req);
+		struct hd_struct *part;
+		int cpu;
 
-		all_stat_add(req->rq_disk, part, sectors[rw],
-				nr_bytes >> 9, req->sector);
+		cpu = part_stat_lock();
+		part = disk_map_sector_rcu(req->rq_disk, req->sector);
+		part_stat_add(cpu, part, sectors[rw], nr_bytes >> 9);
+		part_stat_unlock();
 	}
 
 	total_bytes = bio_nbytes = 0;
@@ -1641,88 +1741,14 @@ static int __end_that_request_first(struct request *req, int error,
 }
 
 /*
- * splice the completion data to a local structure and hand off to
- * process_completion_queue() to complete the requests
- */
-static void blk_done_softirq(struct softirq_action *h)
-{
-	struct list_head *cpu_list, local_list;
-
-	local_irq_disable();
-	cpu_list = &__get_cpu_var(blk_cpu_done);
-	list_replace_init(cpu_list, &local_list);
-	local_irq_enable();
-
-	while (!list_empty(&local_list)) {
-		struct request *rq;
-
-		rq = list_entry(local_list.next, struct request, donelist);
-		list_del_init(&rq->donelist);
-		rq->q->softirq_done_fn(rq);
-	}
-}
-
-static int __cpuinit blk_cpu_notify(struct notifier_block *self,
-				    unsigned long action, void *hcpu)
-{
-	/*
-	 * If a CPU goes away, splice its entries to the current CPU
-	 * and trigger a run of the softirq
-	 */
-	if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
-		int cpu = (unsigned long) hcpu;
-
-		local_irq_disable();
-		list_splice_init(&per_cpu(blk_cpu_done, cpu),
-				 &__get_cpu_var(blk_cpu_done));
-		raise_softirq_irqoff(BLOCK_SOFTIRQ);
-		local_irq_enable();
-	}
-
-	return NOTIFY_OK;
-}
-
-
-static struct notifier_block blk_cpu_notifier __cpuinitdata = {
-	.notifier_call	= blk_cpu_notify,
-};
-
-/**
- * blk_complete_request - end I/O on a request
- * @req:      the request being processed
- *
- * Description:
- *     Ends all I/O on a request. It does not handle partial completions,
- *     unless the driver actually implements this in its completion callback
- *     through requeueing. The actual completion happens out-of-order,
- *     through a softirq handler. The user must have registered a completion
- *     callback through blk_queue_softirq_done().
- **/
-
-void blk_complete_request(struct request *req)
-{
-	struct list_head *cpu_list;
-	unsigned long flags;
-
-	BUG_ON(!req->q->softirq_done_fn);
-
-	local_irq_save(flags);
-
-	cpu_list = &__get_cpu_var(blk_cpu_done);
-	list_add_tail(&req->donelist, cpu_list);
-	raise_softirq_irqoff(BLOCK_SOFTIRQ);
-
-	local_irq_restore(flags);
-}
-EXPORT_SYMBOL(blk_complete_request);
-
-/*
  * queue lock must be held
  */
 static void end_that_request_last(struct request *req, int error)
 {
 	struct gendisk *disk = req->rq_disk;
 
+	blk_delete_timer(req);
+
 	if (blk_rq_tagged(req))
 		blk_queue_end_tag(req->q, req);
 
@@ -1740,16 +1766,18 @@ static void end_that_request_last(struct request *req, int error)
 	if (disk && blk_fs_request(req) && req != &req->q->bar_rq) {
 		unsigned long duration = jiffies - req->start_time;
 		const int rw = rq_data_dir(req);
-		struct hd_struct *part = get_part(disk, req->sector);
-
-		__all_stat_inc(disk, part, ios[rw], req->sector);
-		__all_stat_add(disk, part, ticks[rw], duration, req->sector);
-		disk_round_stats(disk);
-		disk->in_flight--;
-		if (part) {
-			part_round_stats(part);
-			part->in_flight--;
-		}
+		struct hd_struct *part;
+		int cpu;
+
+		cpu = part_stat_lock();
+		part = disk_map_sector_rcu(disk, req->sector);
+
+		part_stat_inc(cpu, part, ios[rw]);
+		part_stat_add(cpu, part, ticks[rw], duration);
+		part_round_stats(cpu, part);
+		part_dec_in_flight(part);
+
+		part_stat_unlock();
 	}
 
 	if (req->end_io)
@@ -1762,17 +1790,6 @@ static void end_that_request_last(struct request *req, int error)
 	}
 }
 
-static inline void __end_request(struct request *rq, int uptodate,
-				 unsigned int nr_bytes)
-{
-	int error = 0;
-
-	if (uptodate <= 0)
-		error = uptodate ? uptodate : -EIO;
-
-	__blk_end_request(rq, error, nr_bytes);
-}
-
 /**
  * blk_rq_bytes - Returns bytes left to complete in the entire request
  * @rq: the request being processed
@@ -1803,74 +1820,57 @@ unsigned int blk_rq_cur_bytes(struct request *rq)
 EXPORT_SYMBOL_GPL(blk_rq_cur_bytes);
 
 /**
- * end_queued_request - end all I/O on a queued request
- * @rq:		the request being processed
- * @uptodate:	error value or 0/1 uptodate flag
- *
- * Description:
- *     Ends all I/O on a request, and removes it from the block layer queues.
- *     Not suitable for normal IO completion, unless the driver still has
- *     the request attached to the block layer.
- *
- **/
-void end_queued_request(struct request *rq, int uptodate)
-{
-	__end_request(rq, uptodate, blk_rq_bytes(rq));
-}
-EXPORT_SYMBOL(end_queued_request);
-
-/**
- * end_dequeued_request - end all I/O on a dequeued request
- * @rq:		the request being processed
- * @uptodate:	error value or 0/1 uptodate flag
- *
- * Description:
- *     Ends all I/O on a request. The request must already have been
- *     dequeued using blkdev_dequeue_request(), as is normally the case
- *     for most drivers.
- *
- **/
-void end_dequeued_request(struct request *rq, int uptodate)
-{
-	__end_request(rq, uptodate, blk_rq_bytes(rq));
-}
-EXPORT_SYMBOL(end_dequeued_request);
-
-
-/**
  * end_request - end I/O on the current segment of the request
  * @req:	the request being processed
- * @uptodate:	error value or 0/1 uptodate flag
+ * @uptodate:	error value or %0/%1 uptodate flag
  *
  * Description:
  *     Ends I/O on the current segment of a request. If that is the only
  *     remaining segment, the request is also completed and freed.
  *
- *     This is a remnant of how older block drivers handled IO completions.
- *     Modern drivers typically end IO on the full request in one go, unless
+ *     This is a remnant of how older block drivers handled I/O completions.
+ *     Modern drivers typically end I/O on the full request in one go, unless
  *     they have a residual value to account for. For that case this function
  *     isn't really useful, unless the residual just happens to be the
  *     full current segment. In other words, don't use this function in new
- *     code. Either use end_request_completely(), or the
- *     end_that_request_chunk() (along with end_that_request_last()) for
- *     partial completions.
- *
+ *     code. Use blk_end_request() or __blk_end_request() to end a request.
  **/
 void end_request(struct request *req, int uptodate)
 {
-	__end_request(req, uptodate, req->hard_cur_sectors << 9);
+	int error = 0;
+
+	if (uptodate <= 0)
+		error = uptodate ? uptodate : -EIO;
+
+	__blk_end_request(req, error, req->hard_cur_sectors << 9);
 }
 EXPORT_SYMBOL(end_request);
 
+static int end_that_request_data(struct request *rq, int error,
+				 unsigned int nr_bytes, unsigned int bidi_bytes)
+{
+	if (rq->bio) {
+		if (__end_that_request_first(rq, error, nr_bytes))
+			return 1;
+
+		/* Bidi request must be completed as a whole */
+		if (blk_bidi_rq(rq) &&
+		    __end_that_request_first(rq->next_rq, error, bidi_bytes))
+			return 1;
+	}
+
+	return 0;
+}
+
 /**
  * blk_end_io - Generic end_io function to complete a request.
  * @rq:           the request being processed
- * @error:        0 for success, < 0 for error
+ * @error:        %0 for success, < %0 for error
  * @nr_bytes:     number of bytes to complete @rq
  * @bidi_bytes:   number of bytes to complete @rq->next_rq
  * @drv_callback: function called between completion of bios in the request
  *                and completion of the request.
- *                If the callback returns non 0, this helper returns without
+ *                If the callback returns non %0, this helper returns without
  *                completion of the request.
  *
  * Description:
@@ -1878,8 +1878,8 @@ EXPORT_SYMBOL(end_request);
  *     If @rq has leftover, sets it up for the next range of segments.
  *
  * Return:
- *     0 - we are done with this request
- *     1 - this request is not freed yet, it still has pending buffers.
+ *     %0 - we are done with this request
+ *     %1 - this request is not freed yet, it still has pending buffers.
  **/
 static int blk_end_io(struct request *rq, int error, unsigned int nr_bytes,
 		      unsigned int bidi_bytes,
@@ -1888,15 +1888,8 @@ static int blk_end_io(struct request *rq, int error, unsigned int nr_bytes,
 	struct request_queue *q = rq->q;
 	unsigned long flags = 0UL;
 
-	if (blk_fs_request(rq) || blk_pc_request(rq)) {
-		if (__end_that_request_first(rq, error, nr_bytes))
-			return 1;
-
-		/* Bidi request must be completed as a whole */
-		if (blk_bidi_rq(rq) &&
-		    __end_that_request_first(rq->next_rq, error, bidi_bytes))
-			return 1;
-	}
+	if (end_that_request_data(rq, error, nr_bytes, bidi_bytes))
+		return 1;
 
 	/* Special feature for tricky drivers */
 	if (drv_callback && drv_callback(rq))
@@ -1914,7 +1907,7 @@ static int blk_end_io(struct request *rq, int error, unsigned int nr_bytes,
 /**
  * blk_end_request - Helper function for drivers to complete the request.
  * @rq:       the request being processed
- * @error:    0 for success, < 0 for error
+ * @error:    %0 for success, < %0 for error
  * @nr_bytes: number of bytes to complete
  *
  * Description:
@@ -1922,8 +1915,8 @@ static int blk_end_io(struct request *rq, int error, unsigned int nr_bytes,
  *     If @rq has leftover, sets it up for the next range of segments.
  *
  * Return:
- *     0 - we are done with this request
- *     1 - still buffers pending for this request
+ *     %0 - we are done with this request
+ *     %1 - still buffers pending for this request
  **/
 int blk_end_request(struct request *rq, int error, unsigned int nr_bytes)
 {
@@ -1934,22 +1927,20 @@ EXPORT_SYMBOL_GPL(blk_end_request);
 /**
  * __blk_end_request - Helper function for drivers to complete the request.
  * @rq:       the request being processed
- * @error:    0 for success, < 0 for error
+ * @error:    %0 for success, < %0 for error
  * @nr_bytes: number of bytes to complete
  *
  * Description:
  *     Must be called with queue lock held unlike blk_end_request().
  *
  * Return:
- *     0 - we are done with this request
- *     1 - still buffers pending for this request
+ *     %0 - we are done with this request
+ *     %1 - still buffers pending for this request
  **/
 int __blk_end_request(struct request *rq, int error, unsigned int nr_bytes)
 {
-	if (blk_fs_request(rq) || blk_pc_request(rq)) {
-		if (__end_that_request_first(rq, error, nr_bytes))
-			return 1;
-	}
+	if (rq->bio && __end_that_request_first(rq, error, nr_bytes))
+		return 1;
 
 	add_disk_randomness(rq->rq_disk);
 
@@ -1962,7 +1953,7 @@ EXPORT_SYMBOL_GPL(__blk_end_request);
 /**
  * blk_end_bidi_request - Helper function for drivers to complete bidi request.
  * @rq:         the bidi request being processed
- * @error:      0 for success, < 0 for error
+ * @error:      %0 for success, < %0 for error
  * @nr_bytes:   number of bytes to complete @rq
  * @bidi_bytes: number of bytes to complete @rq->next_rq
  *
@@ -1970,8 +1961,8 @@ EXPORT_SYMBOL_GPL(__blk_end_request);
  *     Ends I/O on a number of bytes attached to @rq and @rq->next_rq.
  *
  * Return:
- *     0 - we are done with this request
- *     1 - still buffers pending for this request
+ *     %0 - we are done with this request
+ *     %1 - still buffers pending for this request
  **/
 int blk_end_bidi_request(struct request *rq, int error, unsigned int nr_bytes,
 			 unsigned int bidi_bytes)
@@ -1981,13 +1972,43 @@ int blk_end_bidi_request(struct request *rq, int error, unsigned int nr_bytes,
 EXPORT_SYMBOL_GPL(blk_end_bidi_request);
 
 /**
+ * blk_update_request - Special helper function for request stacking drivers
+ * @rq:           the request being processed
+ * @error:        %0 for success, < %0 for error
+ * @nr_bytes:     number of bytes to complete @rq
+ *
+ * Description:
+ *     Ends I/O on a number of bytes attached to @rq, but doesn't complete
+ *     the request structure even if @rq doesn't have leftover.
+ *     If @rq has leftover, sets it up for the next range of segments.
+ *
+ *     This special helper function is only for request stacking drivers
+ *     (e.g. request-based dm) so that they can handle partial completion.
+ *     Actual device drivers should use blk_end_request instead.
+ */
+void blk_update_request(struct request *rq, int error, unsigned int nr_bytes)
+{
+	if (!end_that_request_data(rq, error, nr_bytes, 0)) {
+		/*
+		 * These members are not updated in end_that_request_data()
+		 * when all bios are completed.
+		 * Update them so that the request stacking driver can find
+		 * how many bytes remain in the request later.
+		 */
+		rq->nr_sectors = rq->hard_nr_sectors = 0;
+		rq->current_nr_sectors = rq->hard_cur_sectors = 0;
+	}
+}
+EXPORT_SYMBOL_GPL(blk_update_request);
+
+/**
  * blk_end_request_callback - Special helper function for tricky drivers
  * @rq:           the request being processed
- * @error:        0 for success, < 0 for error
+ * @error:        %0 for success, < %0 for error
  * @nr_bytes:     number of bytes to complete
  * @drv_callback: function called between completion of bios in the request
  *                and completion of the request.
- *                If the callback returns non 0, this helper returns without
+ *                If the callback returns non %0, this helper returns without
  *                completion of the request.
  *
  * Description:
@@ -2000,10 +2021,10 @@ EXPORT_SYMBOL_GPL(blk_end_bidi_request);
  *     Don't use this interface in other places anymore.
  *
  * Return:
- *     0 - we are done with this request
- *     1 - this request is not freed yet.
- *         this request still has pending buffers or
- *         the driver doesn't want to finish this request yet.
+ *     %0 - we are done with this request
+ *     %1 - this request is not freed yet.
+ *          this request still has pending buffers or
+ *          the driver doesn't want to finish this request yet.
  **/
 int blk_end_request_callback(struct request *rq, int error,
 			     unsigned int nr_bytes,
@@ -2016,15 +2037,17 @@ EXPORT_SYMBOL_GPL(blk_end_request_callback);
 void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
 		     struct bio *bio)
 {
-	/* first two bits are identical in rq->cmd_flags and bio->bi_rw */
+	/* Bit 0 (R/W) is identical in rq->cmd_flags and bio->bi_rw, and
+	   we want BIO_RW_AHEAD (bit 1) to imply REQ_FAILFAST (bit 1). */
 	rq->cmd_flags |= (bio->bi_rw & 3);
 
-	rq->nr_phys_segments = bio_phys_segments(q, bio);
-	rq->nr_hw_segments = bio_hw_segments(q, bio);
+	if (bio_has_data(bio)) {
+		rq->nr_phys_segments = bio_phys_segments(q, bio);
+		rq->buffer = bio_data(bio);
+	}
 	rq->current_nr_sectors = bio_cur_sectors(bio);
 	rq->hard_cur_sectors = rq->current_nr_sectors;
 	rq->hard_nr_sectors = rq->nr_sectors = bio_sectors(bio);
-	rq->buffer = bio_data(bio);
 	rq->data_len = bio->bi_size;
 
 	rq->bio = rq->biotail = bio;
@@ -2033,7 +2056,35 @@ void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
 		rq->rq_disk = bio->bi_bdev->bd_disk;
 }
 
-int kblockd_schedule_work(struct work_struct *work)
+/**
+ * blk_lld_busy - Check if underlying low-level drivers of a device are busy
+ * @q : the queue of the device being checked
+ *
+ * Description:
+ *    Check if underlying low-level drivers of a device are busy.
+ *    If the drivers want to export their busy state, they must set own
+ *    exporting function using blk_queue_lld_busy() first.
+ *
+ *    Basically, this function is used only by request stacking drivers
+ *    to stop dispatching requests to underlying devices when underlying
+ *    devices are busy.  This behavior helps more I/O merging on the queue
+ *    of the request stacking driver and prevents I/O throughput regression
+ *    on burst I/O load.
+ *
+ * Return:
+ *    0 - Not busy (The request stacking driver should dispatch request)
+ *    1 - Busy (The request stacking driver should stop dispatching request)
+ */
+int blk_lld_busy(struct request_queue *q)
+{
+	if (q->lld_busy_fn)
+		return q->lld_busy_fn(q);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(blk_lld_busy);
+
+int kblockd_schedule_work(struct request_queue *q, struct work_struct *work)
 {
 	return queue_work(kblockd_workqueue, work);
 }
@@ -2047,8 +2098,6 @@ EXPORT_SYMBOL(kblockd_flush_work);
 
 int __init blk_dev_init(void)
 {
-	int i;
-
 	kblockd_workqueue = create_workqueue("kblockd");
 	if (!kblockd_workqueue)
 		panic("Failed to create kblockd\n");
@@ -2059,12 +2108,6 @@ int __init blk_dev_init(void)
 	blk_requestq_cachep = kmem_cache_create("blkdev_queue",
 			sizeof(struct request_queue), 0, SLAB_PANIC, NULL);
 
-	for_each_possible_cpu(i)
-		INIT_LIST_HEAD(&per_cpu(blk_cpu_done, i));
-
-	open_softirq(BLOCK_SOFTIRQ, blk_done_softirq);
-	register_hotcpu_notifier(&blk_cpu_notifier);
-
 	return 0;
 }
 
diff --git a/block/blk-exec.c b/block/blk-exec.c
index 9bceff7674f..6af716d1e54 100644
--- a/block/blk-exec.c
+++ b/block/blk-exec.c
@@ -16,7 +16,7 @@
 /**
  * blk_end_sync_rq - executes a completion event on a request
  * @rq: request to complete
- * @error: end io status of the request
+ * @error: end I/O status of the request
  */
 static void blk_end_sync_rq(struct request *rq, int error)
 {
@@ -41,7 +41,7 @@ static void blk_end_sync_rq(struct request *rq, int error)
  * @done:	I/O completion handler
  *
  * Description:
- *    Insert a fully prepared request at the back of the io scheduler queue
+ *    Insert a fully prepared request at the back of the I/O scheduler queue
  *    for execution.  Don't wait for completion.
  */
 void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk,
@@ -72,7 +72,7 @@ EXPORT_SYMBOL_GPL(blk_execute_rq_nowait);
  * @at_head:    insert request at head or tail of queue
  *
  * Description:
- *    Insert a fully prepared request at the back of the io scheduler queue
+ *    Insert a fully prepared request at the back of the I/O scheduler queue
  *    for execution and wait for completion.
  */
 int blk_execute_rq(struct request_queue *q, struct gendisk *bd_disk,
diff --git a/block/blk-integrity.c b/block/blk-integrity.c
index 3f1a8478cc3..61a8e2f8fdd 100644
--- a/block/blk-integrity.c
+++ b/block/blk-integrity.c
@@ -108,51 +108,51 @@ new_segment:
 EXPORT_SYMBOL(blk_rq_map_integrity_sg);
 
 /**
- * blk_integrity_compare - Compare integrity profile of two block devices
- * @b1:		Device to compare
- * @b2:		Device to compare
+ * blk_integrity_compare - Compare integrity profile of two disks
+ * @gd1:	Disk to compare
+ * @gd2:	Disk to compare
  *
  * Description: Meta-devices like DM and MD need to verify that all
  * sub-devices use the same integrity format before advertising to
  * upper layers that they can send/receive integrity metadata.  This
- * function can be used to check whether two block devices have
+ * function can be used to check whether two gendisk devices have
  * compatible integrity formats.
  */
-int blk_integrity_compare(struct block_device *bd1, struct block_device *bd2)
+int blk_integrity_compare(struct gendisk *gd1, struct gendisk *gd2)
 {
-	struct blk_integrity *b1 = bd1->bd_disk->integrity;
-	struct blk_integrity *b2 = bd2->bd_disk->integrity;
+	struct blk_integrity *b1 = gd1->integrity;
+	struct blk_integrity *b2 = gd2->integrity;
 
-	BUG_ON(bd1->bd_disk == NULL);
-	BUG_ON(bd2->bd_disk == NULL);
+	if (!b1 && !b2)
+		return 0;
 
 	if (!b1 || !b2)
-		return 0;
+		return -1;
 
 	if (b1->sector_size != b2->sector_size) {
 		printk(KERN_ERR "%s: %s/%s sector sz %u != %u\n", __func__,
-		       bd1->bd_disk->disk_name, bd2->bd_disk->disk_name,
+		       gd1->disk_name, gd2->disk_name,
 		       b1->sector_size, b2->sector_size);
 		return -1;
 	}
 
 	if (b1->tuple_size != b2->tuple_size) {
 		printk(KERN_ERR "%s: %s/%s tuple sz %u != %u\n", __func__,
-		       bd1->bd_disk->disk_name, bd2->bd_disk->disk_name,
+		       gd1->disk_name, gd2->disk_name,
 		       b1->tuple_size, b2->tuple_size);
 		return -1;
 	}
 
 	if (b1->tag_size && b2->tag_size && (b1->tag_size != b2->tag_size)) {
 		printk(KERN_ERR "%s: %s/%s tag sz %u != %u\n", __func__,
-		       bd1->bd_disk->disk_name, bd2->bd_disk->disk_name,
+		       gd1->disk_name, gd2->disk_name,
 		       b1->tag_size, b2->tag_size);
 		return -1;
 	}
 
 	if (strcmp(b1->name, b2->name)) {
 		printk(KERN_ERR "%s: %s/%s type %s != %s\n", __func__,
-		       bd1->bd_disk->disk_name, bd2->bd_disk->disk_name,
+		       gd1->disk_name, gd2->disk_name,
 		       b1->name, b2->name);
 		return -1;
 	}
@@ -331,7 +331,8 @@ int blk_integrity_register(struct gendisk *disk, struct blk_integrity *template)
 			return -1;
 
 		if (kobject_init_and_add(&bi->kobj, &integrity_ktype,
-					 &disk->dev.kobj, "%s", "integrity")) {
+					 &disk_to_dev(disk)->kobj,
+					 "%s", "integrity")) {
 			kmem_cache_free(integrity_cachep, bi);
 			return -1;
 		}
@@ -375,7 +376,7 @@ void blk_integrity_unregister(struct gendisk *disk)
 
 	kobject_uevent(&bi->kobj, KOBJ_REMOVE);
 	kobject_del(&bi->kobj);
-	kobject_put(&disk->dev.kobj);
 	kmem_cache_free(integrity_cachep, bi);
+	disk->integrity = NULL;
 }
 EXPORT_SYMBOL(blk_integrity_unregister);
diff --git a/block/blk-map.c b/block/blk-map.c
index af37e4ae62f..4849fa36161 100644
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -41,10 +41,10 @@ static int __blk_rq_unmap_user(struct bio *bio)
 }
 
 static int __blk_rq_map_user(struct request_queue *q, struct request *rq,
-			     void __user *ubuf, unsigned int len)
+			     struct rq_map_data *map_data, void __user *ubuf,
+			     unsigned int len, int null_mapped, gfp_t gfp_mask)
 {
 	unsigned long uaddr;
-	unsigned int alignment;
 	struct bio *bio, *orig_bio;
 	int reading, ret;
 
@@ -55,15 +55,17 @@ static int __blk_rq_map_user(struct request_queue *q, struct request *rq,
 	 * direct dma. else, set up kernel bounce buffers
 	 */
 	uaddr = (unsigned long) ubuf;
-	alignment = queue_dma_alignment(q) | q->dma_pad_mask;
-	if (!(uaddr & alignment) && !(len & alignment))
-		bio = bio_map_user(q, NULL, uaddr, len, reading);
+	if (blk_rq_aligned(q, ubuf, len) && !map_data)
+		bio = bio_map_user(q, NULL, uaddr, len, reading, gfp_mask);
 	else
-		bio = bio_copy_user(q, uaddr, len, reading);
+		bio = bio_copy_user(q, map_data, uaddr, len, reading, gfp_mask);
 
 	if (IS_ERR(bio))
 		return PTR_ERR(bio);
 
+	if (null_mapped)
+		bio->bi_flags |= (1 << BIO_NULL_MAPPED);
+
 	orig_bio = bio;
 	blk_queue_bounce(q, &bio);
 
@@ -85,17 +87,19 @@ static int __blk_rq_map_user(struct request_queue *q, struct request *rq,
 }
 
 /**
- * blk_rq_map_user - map user data to a request, for REQ_BLOCK_PC usage
+ * blk_rq_map_user - map user data to a request, for REQ_TYPE_BLOCK_PC usage
  * @q:		request queue where request should be inserted
  * @rq:		request structure to fill
+ * @map_data:   pointer to the rq_map_data holding pages (if necessary)
  * @ubuf:	the user buffer
  * @len:	length of user data
+ * @gfp_mask:	memory allocation flags
  *
  * Description:
- *    Data will be mapped directly for zero copy io, if possible. Otherwise
+ *    Data will be mapped directly for zero copy I/O, if possible. Otherwise
  *    a kernel bounce buffer is used.
  *
- *    A matching blk_rq_unmap_user() must be issued at the end of io, while
+ *    A matching blk_rq_unmap_user() must be issued at the end of I/O, while
  *    still in process context.
  *
  *    Note: The mapped bio may need to be bounced through blk_queue_bounce()
@@ -105,16 +109,22 @@ static int __blk_rq_map_user(struct request_queue *q, struct request *rq,
  *    unmapping.
  */
 int blk_rq_map_user(struct request_queue *q, struct request *rq,
-		    void __user *ubuf, unsigned long len)
+		    struct rq_map_data *map_data, void __user *ubuf,
+		    unsigned long len, gfp_t gfp_mask)
 {
 	unsigned long bytes_read = 0;
 	struct bio *bio = NULL;
-	int ret;
+	int ret, null_mapped = 0;
 
 	if (len > (q->max_hw_sectors << 9))
 		return -EINVAL;
-	if (!len || !ubuf)
+	if (!len)
 		return -EINVAL;
+	if (!ubuf) {
+		if (!map_data || rq_data_dir(rq) != READ)
+			return -EINVAL;
+		null_mapped = 1;
+	}
 
 	while (bytes_read != len) {
 		unsigned long map_len, end, start;
@@ -132,7 +142,8 @@ int blk_rq_map_user(struct request_queue *q, struct request *rq,
 		if (end - start > BIO_MAX_PAGES)
 			map_len -= PAGE_SIZE;
 
-		ret = __blk_rq_map_user(q, rq, ubuf, map_len);
+		ret = __blk_rq_map_user(q, rq, map_data, ubuf, map_len,
+					null_mapped, gfp_mask);
 		if (ret < 0)
 			goto unmap_rq;
 		if (!bio)
@@ -154,18 +165,20 @@ unmap_rq:
 EXPORT_SYMBOL(blk_rq_map_user);
 
 /**
- * blk_rq_map_user_iov - map user data to a request, for REQ_BLOCK_PC usage
+ * blk_rq_map_user_iov - map user data to a request, for REQ_TYPE_BLOCK_PC usage
  * @q:		request queue where request should be inserted
  * @rq:		request to map data to
+ * @map_data:   pointer to the rq_map_data holding pages (if necessary)
  * @iov:	pointer to the iovec
  * @iov_count:	number of elements in the iovec
  * @len:	I/O byte count
+ * @gfp_mask:	memory allocation flags
  *
  * Description:
- *    Data will be mapped directly for zero copy io, if possible. Otherwise
+ *    Data will be mapped directly for zero copy I/O, if possible. Otherwise
  *    a kernel bounce buffer is used.
  *
- *    A matching blk_rq_unmap_user() must be issued at the end of io, while
+ *    A matching blk_rq_unmap_user() must be issued at the end of I/O, while
  *    still in process context.
  *
  *    Note: The mapped bio may need to be bounced through blk_queue_bounce()
@@ -175,7 +188,8 @@ EXPORT_SYMBOL(blk_rq_map_user);
  *    unmapping.
  */
 int blk_rq_map_user_iov(struct request_queue *q, struct request *rq,
-			struct sg_iovec *iov, int iov_count, unsigned int len)
+			struct rq_map_data *map_data, struct sg_iovec *iov,
+			int iov_count, unsigned int len, gfp_t gfp_mask)
 {
 	struct bio *bio;
 	int i, read = rq_data_dir(rq) == READ;
@@ -193,10 +207,11 @@ int blk_rq_map_user_iov(struct request_queue *q, struct request *rq,
 		}
 	}
 
-	if (unaligned || (q->dma_pad_mask & len))
-		bio = bio_copy_user_iov(q, iov, iov_count, read);
+	if (unaligned || (q->dma_pad_mask & len) || map_data)
+		bio = bio_copy_user_iov(q, map_data, iov, iov_count, read,
+					gfp_mask);
 	else
-		bio = bio_map_user_iov(q, NULL, iov, iov_count, read);
+		bio = bio_map_user_iov(q, NULL, iov, iov_count, read, gfp_mask);
 
 	if (IS_ERR(bio))
 		return PTR_ERR(bio);
@@ -216,6 +231,7 @@ int blk_rq_map_user_iov(struct request_queue *q, struct request *rq,
 	rq->buffer = rq->data = NULL;
 	return 0;
 }
+EXPORT_SYMBOL(blk_rq_map_user_iov);
 
 /**
  * blk_rq_unmap_user - unmap a request with user data
@@ -224,7 +240,7 @@ int blk_rq_map_user_iov(struct request_queue *q, struct request *rq,
  * Description:
  *    Unmap a rq previously mapped by blk_rq_map_user(). The caller must
  *    supply the original rq->bio from the blk_rq_map_user() return, since
- *    the io completion may have changed rq->bio.
+ *    the I/O completion may have changed rq->bio.
  */
 int blk_rq_unmap_user(struct bio *bio)
 {
@@ -250,7 +266,7 @@ int blk_rq_unmap_user(struct bio *bio)
 EXPORT_SYMBOL(blk_rq_unmap_user);
 
 /**
- * blk_rq_map_kern - map kernel data to a request, for REQ_BLOCK_PC usage
+ * blk_rq_map_kern - map kernel data to a request, for REQ_TYPE_BLOCK_PC usage
  * @q:		request queue where request should be inserted
  * @rq:		request to fill
  * @kbuf:	the kernel buffer
@@ -264,8 +280,6 @@ EXPORT_SYMBOL(blk_rq_unmap_user);
 int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf,
 		    unsigned int len, gfp_t gfp_mask)
 {
-	unsigned long kaddr;
-	unsigned int alignment;
 	int reading = rq_data_dir(rq) == READ;
 	int do_copy = 0;
 	struct bio *bio;
@@ -275,11 +289,7 @@ int blk_rq_map_kern(struct request_queue *q, struct request *rq, void *kbuf,
 	if (!len || !kbuf)
 		return -EINVAL;
 
-	kaddr = (unsigned long)kbuf;
-	alignment = queue_dma_alignment(q) | q->dma_pad_mask;
-	do_copy = ((kaddr & alignment) || (len & alignment) ||
-		   object_is_on_stack(kbuf));
-
+	do_copy = !blk_rq_aligned(q, kbuf, len) || object_is_on_stack(kbuf);
 	if (do_copy)
 		bio = bio_copy_kern(q, kbuf, len, gfp_mask, reading);
 	else
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 5efc9e7a68b..908d3e11ac5 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -11,7 +11,7 @@
 
 void blk_recalc_rq_sectors(struct request *rq, int nsect)
 {
-	if (blk_fs_request(rq)) {
+	if (blk_fs_request(rq) || blk_discard_rq(rq)) {
 		rq->hard_sector += nsect;
 		rq->hard_nr_sectors -= nsect;
 
@@ -41,12 +41,9 @@ void blk_recalc_rq_sectors(struct request *rq, int nsect)
 void blk_recalc_rq_segments(struct request *rq)
 {
 	int nr_phys_segs;
-	int nr_hw_segs;
 	unsigned int phys_size;
-	unsigned int hw_size;
 	struct bio_vec *bv, *bvprv = NULL;
 	int seg_size;
-	int hw_seg_size;
 	int cluster;
 	struct req_iterator iter;
 	int high, highprv = 1;
@@ -56,8 +53,8 @@ void blk_recalc_rq_segments(struct request *rq)
 		return;
 
 	cluster = test_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags);
-	hw_seg_size = seg_size = 0;
-	phys_size = hw_size = nr_phys_segs = nr_hw_segs = 0;
+	seg_size = 0;
+	phys_size = nr_phys_segs = 0;
 	rq_for_each_segment(bv, rq, iter) {
 		/*
 		 * the trick here is making sure that a high page is never
@@ -66,7 +63,7 @@ void blk_recalc_rq_segments(struct request *rq)
 		 */
 		high = page_to_pfn(bv->bv_page) > q->bounce_pfn;
 		if (high || highprv)
-			goto new_hw_segment;
+			goto new_segment;
 		if (cluster) {
 			if (seg_size + bv->bv_len > q->max_segment_size)
 				goto new_segment;
@@ -74,40 +71,19 @@ void blk_recalc_rq_segments(struct request *rq)
 				goto new_segment;
 			if (!BIOVEC_SEG_BOUNDARY(q, bvprv, bv))
 				goto new_segment;
-			if (BIOVEC_VIRT_OVERSIZE(hw_seg_size + bv->bv_len))
-				goto new_hw_segment;
 
 			seg_size += bv->bv_len;
-			hw_seg_size += bv->bv_len;
 			bvprv = bv;
 			continue;
 		}
 new_segment:
-		if (BIOVEC_VIRT_MERGEABLE(bvprv, bv) &&
-		    !BIOVEC_VIRT_OVERSIZE(hw_seg_size + bv->bv_len))
-			hw_seg_size += bv->bv_len;
-		else {
-new_hw_segment:
-			if (nr_hw_segs == 1 &&
-			    hw_seg_size > rq->bio->bi_hw_front_size)
-				rq->bio->bi_hw_front_size = hw_seg_size;
-			hw_seg_size = BIOVEC_VIRT_START_SIZE(bv) + bv->bv_len;
-			nr_hw_segs++;
-		}
-
 		nr_phys_segs++;
 		bvprv = bv;
 		seg_size = bv->bv_len;
 		highprv = high;
 	}
 
-	if (nr_hw_segs == 1 &&
-	    hw_seg_size > rq->bio->bi_hw_front_size)
-		rq->bio->bi_hw_front_size = hw_seg_size;
-	if (hw_seg_size > rq->biotail->bi_hw_back_size)
-		rq->biotail->bi_hw_back_size = hw_seg_size;
 	rq->nr_phys_segments = nr_phys_segs;
-	rq->nr_hw_segments = nr_hw_segs;
 }
 
 void blk_recount_segments(struct request_queue *q, struct bio *bio)
@@ -120,7 +96,6 @@ void blk_recount_segments(struct request_queue *q, struct bio *bio)
 	blk_recalc_rq_segments(&rq);
 	bio->bi_next = nxt;
 	bio->bi_phys_segments = rq.nr_phys_segments;
-	bio->bi_hw_segments = rq.nr_hw_segments;
 	bio->bi_flags |= (1 << BIO_SEG_VALID);
 }
 EXPORT_SYMBOL(blk_recount_segments);
@@ -131,13 +106,17 @@ static int blk_phys_contig_segment(struct request_queue *q, struct bio *bio,
 	if (!test_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags))
 		return 0;
 
-	if (!BIOVEC_PHYS_MERGEABLE(__BVEC_END(bio), __BVEC_START(nxt)))
-		return 0;
 	if (bio->bi_size + nxt->bi_size > q->max_segment_size)
 		return 0;
 
+	if (!bio_has_data(bio))
+		return 1;
+
+	if (!BIOVEC_PHYS_MERGEABLE(__BVEC_END(bio), __BVEC_START(nxt)))
+		return 0;
+
 	/*
-	 * bio and nxt are contigous in memory, check if the queue allows
+	 * bio and nxt are contiguous in memory; check if the queue allows
 	 * these two to be merged into one
 	 */
 	if (BIO_SEG_BOUNDARY(q, bio, nxt))
@@ -146,22 +125,6 @@ static int blk_phys_contig_segment(struct request_queue *q, struct bio *bio,
 	return 0;
 }
 
-static int blk_hw_contig_segment(struct request_queue *q, struct bio *bio,
-				 struct bio *nxt)
-{
-	if (!bio_flagged(bio, BIO_SEG_VALID))
-		blk_recount_segments(q, bio);
-	if (!bio_flagged(nxt, BIO_SEG_VALID))
-		blk_recount_segments(q, nxt);
-	if (!BIOVEC_VIRT_MERGEABLE(__BVEC_END(bio), __BVEC_START(nxt)) ||
-	    BIOVEC_VIRT_OVERSIZE(bio->bi_hw_back_size + nxt->bi_hw_front_size))
-		return 0;
-	if (bio->bi_hw_back_size + nxt->bi_hw_front_size > q->max_segment_size)
-		return 0;
-
-	return 1;
-}
-
 /*
  * map a request to scatterlist, return number of sg entries setup. Caller
  * must make sure sg can hold rq->nr_phys_segments entries
@@ -275,10 +238,9 @@ static inline int ll_new_hw_segment(struct request_queue *q,
 				    struct request *req,
 				    struct bio *bio)
 {
-	int nr_hw_segs = bio_hw_segments(q, bio);
 	int nr_phys_segs = bio_phys_segments(q, bio);
 
-	if (req->nr_hw_segments + nr_hw_segs > q->max_hw_segments
+	if (req->nr_phys_segments + nr_phys_segs > q->max_hw_segments
 	    || req->nr_phys_segments + nr_phys_segs > q->max_phys_segments) {
 		req->cmd_flags |= REQ_NOMERGE;
 		if (req == q->last_merge)
@@ -290,7 +252,6 @@ static inline int ll_new_hw_segment(struct request_queue *q,
 	 * This will form the start of a new hw segment.  Bump both
 	 * counters.
 	 */
-	req->nr_hw_segments += nr_hw_segs;
 	req->nr_phys_segments += nr_phys_segs;
 	return 1;
 }
@@ -299,7 +260,6 @@ int ll_back_merge_fn(struct request_queue *q, struct request *req,
 		     struct bio *bio)
 {
 	unsigned short max_sectors;
-	int len;
 
 	if (unlikely(blk_pc_request(req)))
 		max_sectors = q->max_hw_sectors;
@@ -316,19 +276,6 @@ int ll_back_merge_fn(struct request_queue *q, struct request *req,
 		blk_recount_segments(q, req->biotail);
 	if (!bio_flagged(bio, BIO_SEG_VALID))
 		blk_recount_segments(q, bio);
-	len = req->biotail->bi_hw_back_size + bio->bi_hw_front_size;
-	if (BIOVEC_VIRT_MERGEABLE(__BVEC_END(req->biotail), __BVEC_START(bio))
-	    && !BIOVEC_VIRT_OVERSIZE(len)) {
-		int mergeable =  ll_new_mergeable(q, req, bio);
-
-		if (mergeable) {
-			if (req->nr_hw_segments == 1)
-				req->bio->bi_hw_front_size = len;
-			if (bio->bi_hw_segments == 1)
-				bio->bi_hw_back_size = len;
-		}
-		return mergeable;
-	}
 
 	return ll_new_hw_segment(q, req, bio);
 }
@@ -337,7 +284,6 @@ int ll_front_merge_fn(struct request_queue *q, struct request *req,
 		      struct bio *bio)
 {
 	unsigned short max_sectors;
-	int len;
 
 	if (unlikely(blk_pc_request(req)))
 		max_sectors = q->max_hw_sectors;
@@ -351,23 +297,10 @@ int ll_front_merge_fn(struct request_queue *q, struct request *req,
 			q->last_merge = NULL;
 		return 0;
 	}
-	len = bio->bi_hw_back_size + req->bio->bi_hw_front_size;
 	if (!bio_flagged(bio, BIO_SEG_VALID))
 		blk_recount_segments(q, bio);
 	if (!bio_flagged(req->bio, BIO_SEG_VALID))
 		blk_recount_segments(q, req->bio);
-	if (BIOVEC_VIRT_MERGEABLE(__BVEC_END(bio), __BVEC_START(req->bio)) &&
-	    !BIOVEC_VIRT_OVERSIZE(len)) {
-		int mergeable =  ll_new_mergeable(q, req, bio);
-
-		if (mergeable) {
-			if (bio->bi_hw_segments == 1)
-				bio->bi_hw_front_size = len;
-			if (req->nr_hw_segments == 1)
-				req->biotail->bi_hw_back_size = len;
-		}
-		return mergeable;
-	}
 
 	return ll_new_hw_segment(q, req, bio);
 }
@@ -376,7 +309,6 @@ static int ll_merge_requests_fn(struct request_queue *q, struct request *req,
 				struct request *next)
 {
 	int total_phys_segments;
-	int total_hw_segments;
 
 	/*
 	 * First check if the either of the requests are re-queued
@@ -398,26 +330,11 @@ static int ll_merge_requests_fn(struct request_queue *q, struct request *req,
 	if (total_phys_segments > q->max_phys_segments)
 		return 0;
 
-	total_hw_segments = req->nr_hw_segments + next->nr_hw_segments;
-	if (blk_hw_contig_segment(q, req->biotail, next->bio)) {
-		int len = req->biotail->bi_hw_back_size +
-				next->bio->bi_hw_front_size;
-		/*
-		 * propagate the combined length to the end of the requests
-		 */
-		if (req->nr_hw_segments == 1)
-			req->bio->bi_hw_front_size = len;
-		if (next->nr_hw_segments == 1)
-			next->biotail->bi_hw_back_size = len;
-		total_hw_segments--;
-	}
-
-	if (total_hw_segments > q->max_hw_segments)
+	if (total_phys_segments > q->max_hw_segments)
 		return 0;
 
 	/* Merge is OK... */
 	req->nr_phys_segments = total_phys_segments;
-	req->nr_hw_segments = total_hw_segments;
 	return 1;
 }
 
@@ -470,17 +387,21 @@ static int attempt_merge(struct request_queue *q, struct request *req,
 	elv_merge_requests(q, req, next);
 
 	if (req->rq_disk) {
-		struct hd_struct *part
-			= get_part(req->rq_disk, req->sector);
-		disk_round_stats(req->rq_disk);
-		req->rq_disk->in_flight--;
-		if (part) {
-			part_round_stats(part);
-			part->in_flight--;
-		}
+		struct hd_struct *part;
+		int cpu;
+
+		cpu = part_stat_lock();
+		part = disk_map_sector_rcu(req->rq_disk, req->sector);
+
+		part_round_stats(cpu, part);
+		part_dec_in_flight(part);
+
+		part_stat_unlock();
 	}
 
 	req->ioprio = ioprio_best(req->ioprio, next->ioprio);
+	if (blk_rq_cpu_valid(next))
+		req->cpu = next->cpu;
 
 	__blk_put_request(q, next);
 	return 1;
diff --git a/block/blk-settings.c b/block/blk-settings.c
index dfc77012843..b21dcdb6415 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -33,6 +33,23 @@ void blk_queue_prep_rq(struct request_queue *q, prep_rq_fn *pfn)
 EXPORT_SYMBOL(blk_queue_prep_rq);
 
 /**
+ * blk_queue_set_discard - set a discard_sectors function for queue
+ * @q:		queue
+ * @dfn:	prepare_discard function
+ *
+ * It's possible for a queue to register a discard callback which is used
+ * to transform a discard request into the appropriate type for the
+ * hardware. If none is registered, then discard requests are failed
+ * with %EOPNOTSUPP.
+ *
+ */
+void blk_queue_set_discard(struct request_queue *q, prepare_discard_fn *dfn)
+{
+	q->prepare_discard_fn = dfn;
+}
+EXPORT_SYMBOL(blk_queue_set_discard);
+
+/**
  * blk_queue_merge_bvec - set a merge_bvec function for queue
  * @q:		queue
  * @mbfn:	merge_bvec_fn
@@ -60,6 +77,24 @@ void blk_queue_softirq_done(struct request_queue *q, softirq_done_fn *fn)
 }
 EXPORT_SYMBOL(blk_queue_softirq_done);
 
+void blk_queue_rq_timeout(struct request_queue *q, unsigned int timeout)
+{
+	q->rq_timeout = timeout;
+}
+EXPORT_SYMBOL_GPL(blk_queue_rq_timeout);
+
+void blk_queue_rq_timed_out(struct request_queue *q, rq_timed_out_fn *fn)
+{
+	q->rq_timed_out_fn = fn;
+}
+EXPORT_SYMBOL_GPL(blk_queue_rq_timed_out);
+
+void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn)
+{
+	q->lld_busy_fn = fn;
+}
+EXPORT_SYMBOL_GPL(blk_queue_lld_busy);
+
 /**
  * blk_queue_make_request - define an alternate make_request function for a device
  * @q:  the request queue for the device to be affected
@@ -127,7 +162,7 @@ EXPORT_SYMBOL(blk_queue_make_request);
  *    Different hardware can have different requirements as to what pages
  *    it can do I/O directly to. A low level driver can call
  *    blk_queue_bounce_limit to have lower memory pages allocated as bounce
- *    buffers for doing I/O to pages residing above @page.
+ *    buffers for doing I/O to pages residing above @dma_addr.
  **/
 void blk_queue_bounce_limit(struct request_queue *q, u64 dma_addr)
 {
@@ -212,7 +247,7 @@ EXPORT_SYMBOL(blk_queue_max_phys_segments);
  * Description:
  *    Enables a low level driver to set an upper limit on the number of
  *    hw data segments in a request.  This would be the largest number of
- *    address/length pairs the host adapter can actually give as once
+ *    address/length pairs the host adapter can actually give at once
  *    to the device.
  **/
 void blk_queue_max_hw_segments(struct request_queue *q,
@@ -393,7 +428,7 @@ EXPORT_SYMBOL(blk_queue_segment_boundary);
  * @mask:  alignment mask
  *
  * description:
- *    set required memory and length aligment for direct dma transactions.
+ *    set required memory and length alignment for direct dma transactions.
  *    this is used when buiding direct io requests for the queue.
  *
  **/
@@ -409,7 +444,7 @@ EXPORT_SYMBOL(blk_queue_dma_alignment);
  * @mask:  alignment mask
  *
  * description:
- *    update required memory and length aligment for direct dma transactions.
+ *    update required memory and length alignment for direct dma transactions.
  *    If the requested alignment is larger than the current alignment, then
  *    the current queue alignment is updated to the new value, otherwise it
  *    is left alone.  The design of this is to allow multiple objects
diff --git a/block/blk-softirq.c b/block/blk-softirq.c
new file mode 100644
index 00000000000..e660d26ca65
--- /dev/null
+++ b/block/blk-softirq.c
@@ -0,0 +1,175 @@
+/*
+ * Functions related to softirq rq completions
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/bio.h>
+#include <linux/blkdev.h>
+#include <linux/interrupt.h>
+#include <linux/cpu.h>
+
+#include "blk.h"
+
+static DEFINE_PER_CPU(struct list_head, blk_cpu_done);
+
+/*
+ * Softirq action handler - move entries to local list and loop over them
+ * while passing them to the queue registered handler.
+ */
+static void blk_done_softirq(struct softirq_action *h)
+{
+	struct list_head *cpu_list, local_list;
+
+	local_irq_disable();
+	cpu_list = &__get_cpu_var(blk_cpu_done);
+	list_replace_init(cpu_list, &local_list);
+	local_irq_enable();
+
+	while (!list_empty(&local_list)) {
+		struct request *rq;
+
+		rq = list_entry(local_list.next, struct request, csd.list);
+		list_del_init(&rq->csd.list);
+		rq->q->softirq_done_fn(rq);
+	}
+}
+
+#if defined(CONFIG_SMP) && defined(CONFIG_USE_GENERIC_SMP_HELPERS)
+static void trigger_softirq(void *data)
+{
+	struct request *rq = data;
+	unsigned long flags;
+	struct list_head *list;
+
+	local_irq_save(flags);
+	list = &__get_cpu_var(blk_cpu_done);
+	list_add_tail(&rq->csd.list, list);
+
+	if (list->next == &rq->csd.list)
+		raise_softirq_irqoff(BLOCK_SOFTIRQ);
+
+	local_irq_restore(flags);
+}
+
+/*
+ * Setup and invoke a run of 'trigger_softirq' on the given cpu.
+ */
+static int raise_blk_irq(int cpu, struct request *rq)
+{
+	if (cpu_online(cpu)) {
+		struct call_single_data *data = &rq->csd;
+
+		data->func = trigger_softirq;
+		data->info = rq;
+		data->flags = 0;
+
+		__smp_call_function_single(cpu, data);
+		return 0;
+	}
+
+	return 1;
+}
+#else /* CONFIG_SMP && CONFIG_USE_GENERIC_SMP_HELPERS */
+static int raise_blk_irq(int cpu, struct request *rq)
+{
+	return 1;
+}
+#endif
+
+static int __cpuinit blk_cpu_notify(struct notifier_block *self,
+				    unsigned long action, void *hcpu)
+{
+	/*
+	 * If a CPU goes away, splice its entries to the current CPU
+	 * and trigger a run of the softirq
+	 */
+	if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) {
+		int cpu = (unsigned long) hcpu;
+
+		local_irq_disable();
+		list_splice_init(&per_cpu(blk_cpu_done, cpu),
+				 &__get_cpu_var(blk_cpu_done));
+		raise_softirq_irqoff(BLOCK_SOFTIRQ);
+		local_irq_enable();
+	}
+
+	return NOTIFY_OK;
+}
+
+static struct notifier_block __cpuinitdata blk_cpu_notifier = {
+	.notifier_call	= blk_cpu_notify,
+};
+
+void __blk_complete_request(struct request *req)
+{
+	struct request_queue *q = req->q;
+	unsigned long flags;
+	int ccpu, cpu, group_cpu;
+
+	BUG_ON(!q->softirq_done_fn);
+
+	local_irq_save(flags);
+	cpu = smp_processor_id();
+	group_cpu = blk_cpu_to_group(cpu);
+
+	/*
+	 * Select completion CPU
+	 */
+	if (test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags) && req->cpu != -1)
+		ccpu = req->cpu;
+	else
+		ccpu = cpu;
+
+	if (ccpu == cpu || ccpu == group_cpu) {
+		struct list_head *list;
+do_local:
+		list = &__get_cpu_var(blk_cpu_done);
+		list_add_tail(&req->csd.list, list);
+
+		/*
+		 * if the list only contains our just added request,
+		 * signal a raise of the softirq. If there are already
+		 * entries there, someone already raised the irq but it
+		 * hasn't run yet.
+		 */
+		if (list->next == &req->csd.list)
+			raise_softirq_irqoff(BLOCK_SOFTIRQ);
+	} else if (raise_blk_irq(ccpu, req))
+		goto do_local;
+
+	local_irq_restore(flags);
+}
+
+/**
+ * blk_complete_request - end I/O on a request
+ * @req:      the request being processed
+ *
+ * Description:
+ *     Ends all I/O on a request. It does not handle partial completions,
+ *     unless the driver actually implements this in its completion callback
+ *     through requeueing. The actual completion happens out-of-order,
+ *     through a softirq handler. The user must have registered a completion
+ *     callback through blk_queue_softirq_done().
+ **/
+void blk_complete_request(struct request *req)
+{
+	if (unlikely(blk_should_fake_timeout(req->q)))
+		return;
+	if (!blk_mark_rq_complete(req))
+		__blk_complete_request(req);
+}
+EXPORT_SYMBOL(blk_complete_request);
+
+__init int blk_softirq_init(void)
+{
+	int i;
+
+	for_each_possible_cpu(i)
+		INIT_LIST_HEAD(&per_cpu(blk_cpu_done, i));
+
+	open_softirq(BLOCK_SOFTIRQ, blk_done_softirq);
+	register_hotcpu_notifier(&blk_cpu_notifier);
+	return 0;
+}
+subsys_initcall(blk_softirq_init);
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 304ec73ab82..21e275d7eed 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -156,6 +156,30 @@ static ssize_t queue_nomerges_store(struct request_queue *q, const char *page,
 	return ret;
 }
 
+static ssize_t queue_rq_affinity_show(struct request_queue *q, char *page)
+{
+	unsigned int set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags);
+
+	return queue_var_show(set != 0, page);
+}
+
+static ssize_t
+queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count)
+{
+	ssize_t ret = -EINVAL;
+#if defined(CONFIG_USE_GENERIC_SMP_HELPERS)
+	unsigned long val;
+
+	ret = queue_var_store(&val, page, count);
+	spin_lock_irq(q->queue_lock);
+	if (val)
+		queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
+	else
+		queue_flag_clear(QUEUE_FLAG_SAME_COMP,  q);
+	spin_unlock_irq(q->queue_lock);
+#endif
+	return ret;
+}
 
 static struct queue_sysfs_entry queue_requests_entry = {
 	.attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR },
@@ -197,6 +221,12 @@ static struct queue_sysfs_entry queue_nomerges_entry = {
 	.store = queue_nomerges_store,
 };
 
+static struct queue_sysfs_entry queue_rq_affinity_entry = {
+	.attr = {.name = "rq_affinity", .mode = S_IRUGO | S_IWUSR },
+	.show = queue_rq_affinity_show,
+	.store = queue_rq_affinity_store,
+};
+
 static struct attribute *default_attrs[] = {
 	&queue_requests_entry.attr,
 	&queue_ra_entry.attr,
@@ -205,6 +235,7 @@ static struct attribute *default_attrs[] = {
 	&queue_iosched_entry.attr,
 	&queue_hw_sector_size_entry.attr,
 	&queue_nomerges_entry.attr,
+	&queue_rq_affinity_entry.attr,
 	NULL,
 };
 
@@ -310,7 +341,7 @@ int blk_register_queue(struct gendisk *disk)
 	if (!q->request_fn)
 		return 0;
 
-	ret = kobject_add(&q->kobj, kobject_get(&disk->dev.kobj),
+	ret = kobject_add(&q->kobj, kobject_get(&disk_to_dev(disk)->kobj),
 			  "%s", "queue");
 	if (ret < 0)
 		return ret;
@@ -339,6 +370,6 @@ void blk_unregister_queue(struct gendisk *disk)
 
 		kobject_uevent(&q->kobj, KOBJ_REMOVE);
 		kobject_del(&q->kobj);
-		kobject_put(&disk->dev.kobj);
+		kobject_put(&disk_to_dev(disk)->kobj);
 	}
 }
diff --git a/block/blk-tag.c b/block/blk-tag.c
index ed5166fbc59..c0d419e84ce 100644
--- a/block/blk-tag.c
+++ b/block/blk-tag.c
@@ -29,7 +29,7 @@ EXPORT_SYMBOL(blk_queue_find_tag);
  * __blk_free_tags - release a given set of tag maintenance info
  * @bqt:	the tag map to free
  *
- * Tries to free the specified @bqt@.  Returns true if it was
+ * Tries to free the specified @bqt.  Returns true if it was
  * actually freed and false if there are still references using it
  */
 static int __blk_free_tags(struct blk_queue_tag *bqt)
@@ -78,7 +78,7 @@ void __blk_queue_free_tags(struct request_queue *q)
  * blk_free_tags - release a given set of tag maintenance info
  * @bqt:	the tag map to free
  *
- * For externally managed @bqt@ frees the map.  Callers of this
+ * For externally managed @bqt frees the map.  Callers of this
  * function must guarantee to have released all the queues that
  * might have been using this tag map.
  */
@@ -94,7 +94,7 @@ EXPORT_SYMBOL(blk_free_tags);
  * @q:  the request queue for the device
  *
  *  Notes:
- *	This is used to disabled tagged queuing to a device, yet leave
+ *	This is used to disable tagged queuing to a device, yet leave
  *	queue in function.
  **/
 void blk_queue_free_tags(struct request_queue *q)
@@ -271,7 +271,7 @@ EXPORT_SYMBOL(blk_queue_resize_tags);
  * @rq: the request that has completed
  *
  *  Description:
- *    Typically called when end_that_request_first() returns 0, meaning
+ *    Typically called when end_that_request_first() returns %0, meaning
  *    all transfers have been done for a request. It's important to call
  *    this function before end_that_request_last(), as that will put the
  *    request back on the free list thus corrupting the internal tag list.
@@ -337,6 +337,7 @@ EXPORT_SYMBOL(blk_queue_end_tag);
 int blk_queue_start_tag(struct request_queue *q, struct request *rq)
 {
 	struct blk_queue_tag *bqt = q->queue_tags;
+	unsigned max_depth, offset;
 	int tag;
 
 	if (unlikely((rq->cmd_flags & REQ_QUEUED))) {
@@ -350,10 +351,19 @@ int blk_queue_start_tag(struct request_queue *q, struct request *rq)
 	/*
 	 * Protect against shared tag maps, as we may not have exclusive
 	 * access to the tag map.
+	 *
+	 * We reserve a few tags just for sync IO, since we don't want
+	 * to starve sync IO on behalf of flooding async IO.
 	 */
+	max_depth = bqt->max_depth;
+	if (rq_is_sync(rq))
+		offset = 0;
+	else
+		offset = max_depth >> 2;
+
 	do {
-		tag = find_first_zero_bit(bqt->tag_map, bqt->max_depth);
-		if (tag >= bqt->max_depth)
+		tag = find_next_zero_bit(bqt->tag_map, max_depth, offset);
+		if (tag >= max_depth)
 			return 1;
 
 	} while (test_and_set_bit_lock(tag, bqt->tag_map));
diff --git a/block/blk-timeout.c b/block/blk-timeout.c
new file mode 100644
index 00000000000..972a63f848f
--- /dev/null
+++ b/block/blk-timeout.c
@@ -0,0 +1,238 @@
+/*
+ * Functions related to generic timeout handling of requests.
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/blkdev.h>
+#include <linux/fault-inject.h>
+
+#include "blk.h"
+
+#ifdef CONFIG_FAIL_IO_TIMEOUT
+
+static DECLARE_FAULT_ATTR(fail_io_timeout);
+
+static int __init setup_fail_io_timeout(char *str)
+{
+	return setup_fault_attr(&fail_io_timeout, str);
+}
+__setup("fail_io_timeout=", setup_fail_io_timeout);
+
+int blk_should_fake_timeout(struct request_queue *q)
+{
+	if (!test_bit(QUEUE_FLAG_FAIL_IO, &q->queue_flags))
+		return 0;
+
+	return should_fail(&fail_io_timeout, 1);
+}
+
+static int __init fail_io_timeout_debugfs(void)
+{
+	return init_fault_attr_dentries(&fail_io_timeout, "fail_io_timeout");
+}
+
+late_initcall(fail_io_timeout_debugfs);
+
+ssize_t part_timeout_show(struct device *dev, struct device_attribute *attr,
+			  char *buf)
+{
+	struct gendisk *disk = dev_to_disk(dev);
+	int set = test_bit(QUEUE_FLAG_FAIL_IO, &disk->queue->queue_flags);
+
+	return sprintf(buf, "%d\n", set != 0);
+}
+
+ssize_t part_timeout_store(struct device *dev, struct device_attribute *attr,
+			   const char *buf, size_t count)
+{
+	struct gendisk *disk = dev_to_disk(dev);
+	int val;
+
+	if (count) {
+		struct request_queue *q = disk->queue;
+		char *p = (char *) buf;
+
+		val = simple_strtoul(p, &p, 10);
+		spin_lock_irq(q->queue_lock);
+		if (val)
+			queue_flag_set(QUEUE_FLAG_FAIL_IO, q);
+		else
+			queue_flag_clear(QUEUE_FLAG_FAIL_IO, q);
+		spin_unlock_irq(q->queue_lock);
+	}
+
+	return count;
+}
+
+#endif /* CONFIG_FAIL_IO_TIMEOUT */
+
+/*
+ * blk_delete_timer - Delete/cancel timer for a given function.
+ * @req:	request that we are canceling timer for
+ *
+ */
+void blk_delete_timer(struct request *req)
+{
+	struct request_queue *q = req->q;
+
+	/*
+	 * Nothing to detach
+	 */
+	if (!q->rq_timed_out_fn || !req->deadline)
+		return;
+
+	list_del_init(&req->timeout_list);
+
+	if (list_empty(&q->timeout_list))
+		del_timer(&q->timeout);
+}
+
+static void blk_rq_timed_out(struct request *req)
+{
+	struct request_queue *q = req->q;
+	enum blk_eh_timer_return ret;
+
+	ret = q->rq_timed_out_fn(req);
+	switch (ret) {
+	case BLK_EH_HANDLED:
+		__blk_complete_request(req);
+		break;
+	case BLK_EH_RESET_TIMER:
+		blk_clear_rq_complete(req);
+		blk_add_timer(req);
+		break;
+	case BLK_EH_NOT_HANDLED:
+		/*
+		 * LLD handles this for now but in the future
+		 * we can send a request msg to abort the command
+		 * and we can move more of the generic scsi eh code to
+		 * the blk layer.
+		 */
+		break;
+	default:
+		printk(KERN_ERR "block: bad eh return: %d\n", ret);
+		break;
+	}
+}
+
+void blk_rq_timed_out_timer(unsigned long data)
+{
+	struct request_queue *q = (struct request_queue *) data;
+	unsigned long flags, uninitialized_var(next), next_set = 0;
+	struct request *rq, *tmp;
+
+	spin_lock_irqsave(q->queue_lock, flags);
+
+	list_for_each_entry_safe(rq, tmp, &q->timeout_list, timeout_list) {
+		if (time_after_eq(jiffies, rq->deadline)) {
+			list_del_init(&rq->timeout_list);
+
+			/*
+			 * Check if we raced with end io completion
+			 */
+			if (blk_mark_rq_complete(rq))
+				continue;
+			blk_rq_timed_out(rq);
+		}
+		if (!next_set) {
+			next = rq->deadline;
+			next_set = 1;
+		} else if (time_after(next, rq->deadline))
+			next = rq->deadline;
+	}
+
+	if (next_set && !list_empty(&q->timeout_list))
+		mod_timer(&q->timeout, round_jiffies(next));
+
+	spin_unlock_irqrestore(q->queue_lock, flags);
+}
+
+/**
+ * blk_abort_request -- Request request recovery for the specified command
+ * @req:	pointer to the request of interest
+ *
+ * This function requests that the block layer start recovery for the
+ * request by deleting the timer and calling the q's timeout function.
+ * LLDDs who implement their own error recovery MAY ignore the timeout
+ * event if they generated blk_abort_req. Must hold queue lock.
+ */
+void blk_abort_request(struct request *req)
+{
+	if (blk_mark_rq_complete(req))
+		return;
+	blk_delete_timer(req);
+	blk_rq_timed_out(req);
+}
+EXPORT_SYMBOL_GPL(blk_abort_request);
+
+/**
+ * blk_add_timer - Start timeout timer for a single request
+ * @req:	request that is about to start running.
+ *
+ * Notes:
+ *    Each request has its own timer, and as it is added to the queue, we
+ *    set up the timer. When the request completes, we cancel the timer.
+ */
+void blk_add_timer(struct request *req)
+{
+	struct request_queue *q = req->q;
+	unsigned long expiry;
+
+	if (!q->rq_timed_out_fn)
+		return;
+
+	BUG_ON(!list_empty(&req->timeout_list));
+	BUG_ON(test_bit(REQ_ATOM_COMPLETE, &req->atomic_flags));
+
+	if (req->timeout)
+		req->deadline = jiffies + req->timeout;
+	else {
+		req->deadline = jiffies + q->rq_timeout;
+		/*
+		 * Some LLDs, like scsi, peek at the timeout to prevent
+		 * a command from being retried forever.
+		 */
+		req->timeout = q->rq_timeout;
+	}
+	list_add_tail(&req->timeout_list, &q->timeout_list);
+
+	/*
+	 * If the timer isn't already pending or this timeout is earlier
+	 * than an existing one, modify the timer. Round to next nearest
+	 * second.
+	 */
+	expiry = round_jiffies(req->deadline);
+
+	/*
+	 * We use ->deadline == 0 to detect whether a timer was added or
+	 * not, so just increase to next jiffy for that specific case
+	 */
+	if (unlikely(!req->deadline))
+		req->deadline = 1;
+
+	if (!timer_pending(&q->timeout) ||
+	    time_before(expiry, q->timeout.expires))
+		mod_timer(&q->timeout, expiry);
+}
+
+/**
+ * blk_abort_queue -- Abort all request on given queue
+ * @queue:	pointer to queue
+ *
+ */
+void blk_abort_queue(struct request_queue *q)
+{
+	unsigned long flags;
+	struct request *rq, *tmp;
+
+	spin_lock_irqsave(q->queue_lock, flags);
+
+	elv_abort_queue(q);
+
+	list_for_each_entry_safe(rq, tmp, &q->timeout_list, timeout_list)
+		blk_abort_request(rq);
+
+	spin_unlock_irqrestore(q->queue_lock, flags);
+
+}
+EXPORT_SYMBOL_GPL(blk_abort_queue);
diff --git a/block/blk.h b/block/blk.h
index c79f30e1df5..e5c57976996 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -17,6 +17,42 @@ void __blk_queue_free_tags(struct request_queue *q);
 
 void blk_unplug_work(struct work_struct *work);
 void blk_unplug_timeout(unsigned long data);
+void blk_rq_timed_out_timer(unsigned long data);
+void blk_delete_timer(struct request *);
+void blk_add_timer(struct request *);
+
+/*
+ * Internal atomic flags for request handling
+ */
+enum rq_atomic_flags {
+	REQ_ATOM_COMPLETE = 0,
+};
+
+/*
+ * EH timer and IO completion will both attempt to 'grab' the request, make
+ * sure that only one of them suceeds
+ */
+static inline int blk_mark_rq_complete(struct request *rq)
+{
+	return test_and_set_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
+}
+
+static inline void blk_clear_rq_complete(struct request *rq)
+{
+	clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
+}
+
+#ifdef CONFIG_FAIL_IO_TIMEOUT
+int blk_should_fake_timeout(struct request_queue *);
+ssize_t part_timeout_show(struct device *, struct device_attribute *, char *);
+ssize_t part_timeout_store(struct device *, struct device_attribute *,
+				const char *, size_t);
+#else
+static inline int blk_should_fake_timeout(struct request_queue *q)
+{
+	return 0;
+}
+#endif
 
 struct io_context *current_io_context(gfp_t gfp_flags, int node);
 
@@ -59,4 +95,16 @@ static inline int queue_congestion_off_threshold(struct request_queue *q)
 
 #endif /* BLK_DEV_INTEGRITY */
 
+static inline int blk_cpu_to_group(int cpu)
+{
+#ifdef CONFIG_SCHED_MC
+	cpumask_t mask = cpu_coregroup_map(cpu);
+	return first_cpu(mask);
+#elif defined(CONFIG_SCHED_SMT)
+	return first_cpu(per_cpu(cpu_sibling_map, cpu));
+#else
+	return cpu;
+#endif
+}
+
 #endif
diff --git a/block/blktrace.c b/block/blktrace.c
index eb9651ccb24..85049a7e7a1 100644
--- a/block/blktrace.c
+++ b/block/blktrace.c
@@ -111,23 +111,9 @@ static int act_log_check(struct blk_trace *bt, u32 what, sector_t sector,
  */
 static u32 ddir_act[2] __read_mostly = { BLK_TC_ACT(BLK_TC_READ), BLK_TC_ACT(BLK_TC_WRITE) };
 
-/*
- * Bio action bits of interest
- */
-static u32 bio_act[9] __read_mostly = { 0, BLK_TC_ACT(BLK_TC_BARRIER), BLK_TC_ACT(BLK_TC_SYNC), 0, BLK_TC_ACT(BLK_TC_AHEAD), 0, 0, 0, BLK_TC_ACT(BLK_TC_META) };
-
-/*
- * More could be added as needed, taking care to increment the decrementer
- * to get correct indexing
- */
-#define trace_barrier_bit(rw)	\
-	(((rw) & (1 << BIO_RW_BARRIER)) >> (BIO_RW_BARRIER - 0))
-#define trace_sync_bit(rw)	\
-	(((rw) & (1 << BIO_RW_SYNC)) >> (BIO_RW_SYNC - 1))
-#define trace_ahead_bit(rw)	\
-	(((rw) & (1 << BIO_RW_AHEAD)) << (2 - BIO_RW_AHEAD))
-#define trace_meta_bit(rw)	\
-	(((rw) & (1 << BIO_RW_META)) >> (BIO_RW_META - 3))
+/* The ilog2() calls fall out because they're constant */
+#define MASK_TC_BIT(rw, __name) ( (rw & (1 << BIO_RW_ ## __name)) << \
+	  (ilog2(BLK_TC_ ## __name) + BLK_TC_SHIFT - BIO_RW_ ## __name) )
 
 /*
  * The worker for the various blk_add_trace*() types. Fills out a
@@ -147,10 +133,11 @@ void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
 		return;
 
 	what |= ddir_act[rw & WRITE];
-	what |= bio_act[trace_barrier_bit(rw)];
-	what |= bio_act[trace_sync_bit(rw)];
-	what |= bio_act[trace_ahead_bit(rw)];
-	what |= bio_act[trace_meta_bit(rw)];
+	what |= MASK_TC_BIT(rw, BARRIER);
+	what |= MASK_TC_BIT(rw, SYNC);
+	what |= MASK_TC_BIT(rw, AHEAD);
+	what |= MASK_TC_BIT(rw, META);
+	what |= MASK_TC_BIT(rw, DISCARD);
 
 	pid = tsk->pid;
 	if (unlikely(act_log_check(bt, what, sector, pid)))
@@ -382,7 +369,8 @@ int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
 	if (!buts->buf_size || !buts->buf_nr)
 		return -EINVAL;
 
-	strcpy(buts->name, name);
+	strncpy(buts->name, name, BLKTRACE_BDEV_SIZE);
+	buts->name[BLKTRACE_BDEV_SIZE - 1] = '\0';
 
 	/*
 	 * some device names have larger paths - convert the slashes
diff --git a/block/bsg.c b/block/bsg.c
index 0aae8d7ba99..56cb343c76d 100644
--- a/block/bsg.c
+++ b/block/bsg.c
@@ -283,7 +283,8 @@ bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr, int has_write_perm)
 		next_rq->cmd_type = rq->cmd_type;
 
 		dxferp = (void*)(unsigned long)hdr->din_xferp;
-		ret =  blk_rq_map_user(q, next_rq, dxferp, hdr->din_xfer_len);
+		ret =  blk_rq_map_user(q, next_rq, NULL, dxferp,
+				       hdr->din_xfer_len, GFP_KERNEL);
 		if (ret)
 			goto out;
 	}
@@ -298,7 +299,8 @@ bsg_map_hdr(struct bsg_device *bd, struct sg_io_v4 *hdr, int has_write_perm)
 		dxfer_len = 0;
 
 	if (dxfer_len) {
-		ret = blk_rq_map_user(q, rq, dxferp, dxfer_len);
+		ret = blk_rq_map_user(q, rq, NULL, dxferp, dxfer_len,
+				      GFP_KERNEL);
 		if (ret)
 			goto out;
 	}
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 1e2aff812ee..6a062eebbd1 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -39,6 +39,7 @@ static int cfq_slice_idle = HZ / 125;
 #define CFQ_MIN_TT		(2)
 
 #define CFQ_SLICE_SCALE		(5)
+#define CFQ_HW_QUEUE_MIN	(5)
 
 #define RQ_CIC(rq)		\
 	((struct cfq_io_context *) (rq)->elevator_private)
@@ -86,7 +87,14 @@ struct cfq_data {
 
 	int rq_in_driver;
 	int sync_flight;
+
+	/*
+	 * queue-depth detection
+	 */
+	int rq_queued;
 	int hw_tag;
+	int hw_tag_samples;
+	int rq_in_driver_peak;
 
 	/*
 	 * idle window management
@@ -244,7 +252,7 @@ static inline void cfq_schedule_dispatch(struct cfq_data *cfqd)
 {
 	if (cfqd->busy_queues) {
 		cfq_log(cfqd, "schedule dispatch");
-		kblockd_schedule_work(&cfqd->unplug_work);
+		kblockd_schedule_work(cfqd->queue, &cfqd->unplug_work);
 	}
 }
 
@@ -654,15 +662,6 @@ static void cfq_activate_request(struct request_queue *q, struct request *rq)
 	cfq_log_cfqq(cfqd, RQ_CFQQ(rq), "activate rq, drv=%d",
 						cfqd->rq_in_driver);
 
-	/*
-	 * If the depth is larger 1, it really could be queueing. But lets
-	 * make the mark a little higher - idling could still be good for
-	 * low queueing, and a low queueing number could also just indicate
-	 * a SCSI mid layer like behaviour where limit+1 is often seen.
-	 */
-	if (!cfqd->hw_tag && cfqd->rq_in_driver > 4)
-		cfqd->hw_tag = 1;
-
 	cfqd->last_position = rq->hard_sector + rq->hard_nr_sectors;
 }
 
@@ -686,6 +685,7 @@ static void cfq_remove_request(struct request *rq)
 	list_del_init(&rq->queuelist);
 	cfq_del_rq_rb(rq);
 
+	cfqq->cfqd->rq_queued--;
 	if (rq_is_meta(rq)) {
 		WARN_ON(!cfqq->meta_pending);
 		cfqq->meta_pending--;
@@ -878,6 +878,14 @@ static void cfq_arm_slice_timer(struct cfq_data *cfqd)
 	struct cfq_io_context *cic;
 	unsigned long sl;
 
+	/*
+	 * SSD device without seek penalty, disable idling. But only do so
+	 * for devices that support queuing, otherwise we still have a problem
+	 * with sync vs async workloads.
+	 */
+	if (blk_queue_nonrot(cfqd->queue) && cfqd->hw_tag)
+		return;
+
 	WARN_ON(!RB_EMPTY_ROOT(&cfqq->sort_list));
 	WARN_ON(cfq_cfqq_slice_new(cfqq));
 
@@ -1833,6 +1841,7 @@ cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq,
 {
 	struct cfq_io_context *cic = RQ_CIC(rq);
 
+	cfqd->rq_queued++;
 	if (rq_is_meta(rq))
 		cfqq->meta_pending++;
 
@@ -1880,6 +1889,31 @@ static void cfq_insert_request(struct request_queue *q, struct request *rq)
 	cfq_rq_enqueued(cfqd, cfqq, rq);
 }
 
+/*
+ * Update hw_tag based on peak queue depth over 50 samples under
+ * sufficient load.
+ */
+static void cfq_update_hw_tag(struct cfq_data *cfqd)
+{
+	if (cfqd->rq_in_driver > cfqd->rq_in_driver_peak)
+		cfqd->rq_in_driver_peak = cfqd->rq_in_driver;
+
+	if (cfqd->rq_queued <= CFQ_HW_QUEUE_MIN &&
+	    cfqd->rq_in_driver <= CFQ_HW_QUEUE_MIN)
+		return;
+
+	if (cfqd->hw_tag_samples++ < 50)
+		return;
+
+	if (cfqd->rq_in_driver_peak >= CFQ_HW_QUEUE_MIN)
+		cfqd->hw_tag = 1;
+	else
+		cfqd->hw_tag = 0;
+
+	cfqd->hw_tag_samples = 0;
+	cfqd->rq_in_driver_peak = 0;
+}
+
 static void cfq_completed_request(struct request_queue *q, struct request *rq)
 {
 	struct cfq_queue *cfqq = RQ_CFQQ(rq);
@@ -1890,6 +1924,8 @@ static void cfq_completed_request(struct request_queue *q, struct request *rq)
 	now = jiffies;
 	cfq_log_cfqq(cfqd, cfqq, "complete");
 
+	cfq_update_hw_tag(cfqd);
+
 	WARN_ON(!cfqd->rq_in_driver);
 	WARN_ON(!cfqq->dispatched);
 	cfqd->rq_in_driver--;
@@ -2200,6 +2236,7 @@ static void *cfq_init_queue(struct request_queue *q)
 	cfqd->cfq_slice[1] = cfq_slice_sync;
 	cfqd->cfq_slice_async_rq = cfq_slice_async_rq;
 	cfqd->cfq_slice_idle = cfq_slice_idle;
+	cfqd->hw_tag = 1;
 
 	return cfqd;
 }
diff --git a/block/cmd-filter.c b/block/cmd-filter.c
index 79c14996ac1..e669aed4c6b 100644
--- a/block/cmd-filter.c
+++ b/block/cmd-filter.c
@@ -211,14 +211,10 @@ int blk_register_filter(struct gendisk *disk)
 {
 	int ret;
 	struct blk_cmd_filter *filter = &disk->queue->cmd_filter;
-	struct kobject *parent = kobject_get(disk->holder_dir->parent);
 
-	if (!parent)
-		return -ENODEV;
-
-	ret = kobject_init_and_add(&filter->kobj, &rcf_ktype, parent,
+	ret = kobject_init_and_add(&filter->kobj, &rcf_ktype,
+				   &disk_to_dev(disk)->kobj,
 				   "%s", "cmd_filter");
-
 	if (ret < 0)
 		return ret;
 
@@ -231,7 +227,6 @@ void blk_unregister_filter(struct gendisk *disk)
 	struct blk_cmd_filter *filter = &disk->queue->cmd_filter;
 
 	kobject_put(&filter->kobj);
-	kobject_put(disk->holder_dir->parent);
 }
 EXPORT_SYMBOL(blk_unregister_filter);
 #endif
diff --git a/block/compat_ioctl.c b/block/compat_ioctl.c
index c23177e4623..1e559fba7bd 100644
--- a/block/compat_ioctl.c
+++ b/block/compat_ioctl.c
@@ -788,6 +788,7 @@ long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 		return compat_hdio_getgeo(disk, bdev, compat_ptr(arg));
 	case BLKFLSBUF:
 	case BLKROSET:
+	case BLKDISCARD:
 	/*
 	 * the ones below are implemented in blkdev_locked_ioctl,
 	 * but we call blkdev_ioctl, which gets the lock for us
diff --git a/block/deadline-iosched.c b/block/deadline-iosched.c
index 342448c3d2d..fd311179f44 100644
--- a/block/deadline-iosched.c
+++ b/block/deadline-iosched.c
@@ -33,7 +33,7 @@ struct deadline_data {
 	 */
 	struct rb_root sort_list[2];	
 	struct list_head fifo_list[2];
-	
+
 	/*
 	 * next in sort order. read, write or both are NULL
 	 */
@@ -53,7 +53,11 @@ struct deadline_data {
 
 static void deadline_move_request(struct deadline_data *, struct request *);
 
-#define RQ_RB_ROOT(dd, rq)	(&(dd)->sort_list[rq_data_dir((rq))])
+static inline struct rb_root *
+deadline_rb_root(struct deadline_data *dd, struct request *rq)
+{
+	return &dd->sort_list[rq_data_dir(rq)];
+}
 
 /*
  * get the request after `rq' in sector-sorted order
@@ -72,15 +76,11 @@ deadline_latter_request(struct request *rq)
 static void
 deadline_add_rq_rb(struct deadline_data *dd, struct request *rq)
 {
-	struct rb_root *root = RQ_RB_ROOT(dd, rq);
+	struct rb_root *root = deadline_rb_root(dd, rq);
 	struct request *__alias;
 
-retry:
-	__alias = elv_rb_add(root, rq);
-	if (unlikely(__alias)) {
+	while (unlikely(__alias = elv_rb_add(root, rq)))
 		deadline_move_request(dd, __alias);
-		goto retry;
-	}
 }
 
 static inline void
@@ -91,7 +91,7 @@ deadline_del_rq_rb(struct deadline_data *dd, struct request *rq)
 	if (dd->next_rq[data_dir] == rq)
 		dd->next_rq[data_dir] = deadline_latter_request(rq);
 
-	elv_rb_del(RQ_RB_ROOT(dd, rq), rq);
+	elv_rb_del(deadline_rb_root(dd, rq), rq);
 }
 
 /*
@@ -106,7 +106,7 @@ deadline_add_request(struct request_queue *q, struct request *rq)
 	deadline_add_rq_rb(dd, rq);
 
 	/*
-	 * set expire time (only used for reads) and add to fifo list
+	 * set expire time and add to fifo list
 	 */
 	rq_set_fifo_time(rq, jiffies + dd->fifo_expire[data_dir]);
 	list_add_tail(&rq->queuelist, &dd->fifo_list[data_dir]);
@@ -162,7 +162,7 @@ static void deadline_merged_request(struct request_queue *q,
 	 * if the merge was a front merge, we need to reposition request
 	 */
 	if (type == ELEVATOR_FRONT_MERGE) {
-		elv_rb_del(RQ_RB_ROOT(dd, req), req);
+		elv_rb_del(deadline_rb_root(dd, req), req);
 		deadline_add_rq_rb(dd, req);
 	}
 }
@@ -212,7 +212,7 @@ deadline_move_request(struct deadline_data *dd, struct request *rq)
 	dd->next_rq[WRITE] = NULL;
 	dd->next_rq[data_dir] = deadline_latter_request(rq);
 
-	dd->last_sector = rq->sector + rq->nr_sectors;
+	dd->last_sector = rq_end_sector(rq);
 
 	/*
 	 * take it off the sort and fifo list, move
@@ -222,7 +222,7 @@ deadline_move_request(struct deadline_data *dd, struct request *rq)
 }
 
 /*
- * deadline_check_fifo returns 0 if there are no expired reads on the fifo,
+ * deadline_check_fifo returns 0 if there are no expired requests on the fifo,
  * 1 otherwise. Requires !list_empty(&dd->fifo_list[data_dir])
  */
 static inline int deadline_check_fifo(struct deadline_data *dd, int ddir)
@@ -258,17 +258,9 @@ static int deadline_dispatch_requests(struct request_queue *q, int force)
 	else
 		rq = dd->next_rq[READ];
 
-	if (rq) {
-		/* we have a "next request" */
-		
-		if (dd->last_sector != rq->sector)
-			/* end the batch on a non sequential request */
-			dd->batching += dd->fifo_batch;
-		
-		if (dd->batching < dd->fifo_batch)
-			/* we are still entitled to batch */
-			goto dispatch_request;
-	}
+	if (rq && dd->batching < dd->fifo_batch)
+		/* we have a next request are still entitled to batch */
+		goto dispatch_request;
 
 	/*
 	 * at this point we are not running a batch. select the appropriate
diff --git a/block/elevator.c b/block/elevator.c
index ed6f8f32d27..04518921db3 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -34,8 +34,9 @@
 #include <linux/delay.h>
 #include <linux/blktrace_api.h>
 #include <linux/hash.h>
+#include <linux/uaccess.h>
 
-#include <asm/uaccess.h>
+#include "blk.h"
 
 static DEFINE_SPINLOCK(elv_list_lock);
 static LIST_HEAD(elv_list);
@@ -75,6 +76,12 @@ int elv_rq_merge_ok(struct request *rq, struct bio *bio)
 		return 0;
 
 	/*
+	 * Don't merge file system requests and discard requests
+	 */
+	if (bio_discard(bio) != bio_discard(rq->bio))
+		return 0;
+
+	/*
 	 * different data direction or already started, don't merge
 	 */
 	if (bio_data_dir(bio) != rq_data_dir(rq))
@@ -438,6 +445,8 @@ void elv_dispatch_sort(struct request_queue *q, struct request *rq)
 	list_for_each_prev(entry, &q->queue_head) {
 		struct request *pos = list_entry_rq(entry);
 
+		if (blk_discard_rq(rq) != blk_discard_rq(pos))
+			break;
 		if (rq_data_dir(rq) != rq_data_dir(pos))
 			break;
 		if (pos->cmd_flags & stop_flags)
@@ -607,7 +616,7 @@ void elv_insert(struct request_queue *q, struct request *rq, int where)
 		break;
 
 	case ELEVATOR_INSERT_SORT:
-		BUG_ON(!blk_fs_request(rq));
+		BUG_ON(!blk_fs_request(rq) && !blk_discard_rq(rq));
 		rq->cmd_flags |= REQ_SORTED;
 		q->nr_sorted++;
 		if (rq_mergeable(rq)) {
@@ -692,7 +701,7 @@ void __elv_add_request(struct request_queue *q, struct request *rq, int where,
 		 * this request is scheduling boundary, update
 		 * end_sector
 		 */
-		if (blk_fs_request(rq)) {
+		if (blk_fs_request(rq) || blk_discard_rq(rq)) {
 			q->end_sector = rq_end_sector(rq);
 			q->boundary_rq = rq;
 		}
@@ -745,7 +754,7 @@ struct request *elv_next_request(struct request_queue *q)
 		 * not ever see it.
 		 */
 		if (blk_empty_barrier(rq)) {
-			end_queued_request(rq, 1);
+			__blk_end_request(rq, 0, blk_rq_bytes(rq));
 			continue;
 		}
 		if (!(rq->cmd_flags & REQ_STARTED)) {
@@ -764,6 +773,12 @@ struct request *elv_next_request(struct request_queue *q)
 			 */
 			rq->cmd_flags |= REQ_STARTED;
 			blk_add_trace_rq(q, rq, BLK_TA_ISSUE);
+
+			/*
+			 * We are now handing the request to the hardware,
+			 * add the timeout handler
+			 */
+			blk_add_timer(rq);
 		}
 
 		if (!q->boundary_rq || q->boundary_rq == rq) {
@@ -782,7 +797,6 @@ struct request *elv_next_request(struct request_queue *q)
 			 * device can handle
 			 */
 			rq->nr_phys_segments++;
-			rq->nr_hw_segments++;
 		}
 
 		if (!q->prep_rq_fn)
@@ -805,14 +819,13 @@ struct request *elv_next_request(struct request_queue *q)
 				 * so that we don't add it again
 				 */
 				--rq->nr_phys_segments;
-				--rq->nr_hw_segments;
 			}
 
 			rq = NULL;
 			break;
 		} else if (ret == BLKPREP_KILL) {
 			rq->cmd_flags |= REQ_QUIET;
-			end_queued_request(rq, 0);
+			__blk_end_request(rq, -EIO, blk_rq_bytes(rq));
 		} else {
 			printk(KERN_ERR "%s: bad return=%d\n", __func__, ret);
 			break;
@@ -901,6 +914,19 @@ int elv_may_queue(struct request_queue *q, int rw)
 	return ELV_MQUEUE_MAY;
 }
 
+void elv_abort_queue(struct request_queue *q)
+{
+	struct request *rq;
+
+	while (!list_empty(&q->queue_head)) {
+		rq = list_entry_rq(q->queue_head.next);
+		rq->cmd_flags |= REQ_QUIET;
+		blk_add_trace_rq(q, rq, BLK_TA_ABORT);
+		__blk_end_request(rq, -EIO, blk_rq_bytes(rq));
+	}
+}
+EXPORT_SYMBOL(elv_abort_queue);
+
 void elv_completed_request(struct request_queue *q, struct request *rq)
 {
 	elevator_t *e = q->elevator;
diff --git a/block/genhd.c b/block/genhd.c
index e0ce23ac2ec..4cd3433c99a 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -16,6 +16,7 @@
 #include <linux/kobj_map.h>
 #include <linux/buffer_head.h>
 #include <linux/mutex.h>
+#include <linux/idr.h>
 
 #include "blk.h"
 
@@ -24,8 +25,194 @@ static DEFINE_MUTEX(block_class_lock);
 struct kobject *block_depr;
 #endif
 
+/* for extended dynamic devt allocation, currently only one major is used */
+#define MAX_EXT_DEVT		(1 << MINORBITS)
+
+/* For extended devt allocation.  ext_devt_mutex prevents look up
+ * results from going away underneath its user.
+ */
+static DEFINE_MUTEX(ext_devt_mutex);
+static DEFINE_IDR(ext_devt_idr);
+
 static struct device_type disk_type;
 
+/**
+ * disk_get_part - get partition
+ * @disk: disk to look partition from
+ * @partno: partition number
+ *
+ * Look for partition @partno from @disk.  If found, increment
+ * reference count and return it.
+ *
+ * CONTEXT:
+ * Don't care.
+ *
+ * RETURNS:
+ * Pointer to the found partition on success, NULL if not found.
+ */
+struct hd_struct *disk_get_part(struct gendisk *disk, int partno)
+{
+	struct hd_struct *part = NULL;
+	struct disk_part_tbl *ptbl;
+
+	if (unlikely(partno < 0))
+		return NULL;
+
+	rcu_read_lock();
+
+	ptbl = rcu_dereference(disk->part_tbl);
+	if (likely(partno < ptbl->len)) {
+		part = rcu_dereference(ptbl->part[partno]);
+		if (part)
+			get_device(part_to_dev(part));
+	}
+
+	rcu_read_unlock();
+
+	return part;
+}
+EXPORT_SYMBOL_GPL(disk_get_part);
+
+/**
+ * disk_part_iter_init - initialize partition iterator
+ * @piter: iterator to initialize
+ * @disk: disk to iterate over
+ * @flags: DISK_PITER_* flags
+ *
+ * Initialize @piter so that it iterates over partitions of @disk.
+ *
+ * CONTEXT:
+ * Don't care.
+ */
+void disk_part_iter_init(struct disk_part_iter *piter, struct gendisk *disk,
+			  unsigned int flags)
+{
+	struct disk_part_tbl *ptbl;
+
+	rcu_read_lock();
+	ptbl = rcu_dereference(disk->part_tbl);
+
+	piter->disk = disk;
+	piter->part = NULL;
+
+	if (flags & DISK_PITER_REVERSE)
+		piter->idx = ptbl->len - 1;
+	else if (flags & DISK_PITER_INCL_PART0)
+		piter->idx = 0;
+	else
+		piter->idx = 1;
+
+	piter->flags = flags;
+
+	rcu_read_unlock();
+}
+EXPORT_SYMBOL_GPL(disk_part_iter_init);
+
+/**
+ * disk_part_iter_next - proceed iterator to the next partition and return it
+ * @piter: iterator of interest
+ *
+ * Proceed @piter to the next partition and return it.
+ *
+ * CONTEXT:
+ * Don't care.
+ */
+struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter)
+{
+	struct disk_part_tbl *ptbl;
+	int inc, end;
+
+	/* put the last partition */
+	disk_put_part(piter->part);
+	piter->part = NULL;
+
+	/* get part_tbl */
+	rcu_read_lock();
+	ptbl = rcu_dereference(piter->disk->part_tbl);
+
+	/* determine iteration parameters */
+	if (piter->flags & DISK_PITER_REVERSE) {
+		inc = -1;
+		if (piter->flags & DISK_PITER_INCL_PART0)
+			end = -1;
+		else
+			end = 0;
+	} else {
+		inc = 1;
+		end = ptbl->len;
+	}
+
+	/* iterate to the next partition */
+	for (; piter->idx != end; piter->idx += inc) {
+		struct hd_struct *part;
+
+		part = rcu_dereference(ptbl->part[piter->idx]);
+		if (!part)
+			continue;
+		if (!(piter->flags & DISK_PITER_INCL_EMPTY) && !part->nr_sects)
+			continue;
+
+		get_device(part_to_dev(part));
+		piter->part = part;
+		piter->idx += inc;
+		break;
+	}
+
+	rcu_read_unlock();
+
+	return piter->part;
+}
+EXPORT_SYMBOL_GPL(disk_part_iter_next);
+
+/**
+ * disk_part_iter_exit - finish up partition iteration
+ * @piter: iter of interest
+ *
+ * Called when iteration is over.  Cleans up @piter.
+ *
+ * CONTEXT:
+ * Don't care.
+ */
+void disk_part_iter_exit(struct disk_part_iter *piter)
+{
+	disk_put_part(piter->part);
+	piter->part = NULL;
+}
+EXPORT_SYMBOL_GPL(disk_part_iter_exit);
+
+/**
+ * disk_map_sector_rcu - map sector to partition
+ * @disk: gendisk of interest
+ * @sector: sector to map
+ *
+ * Find out which partition @sector maps to on @disk.  This is
+ * primarily used for stats accounting.
+ *
+ * CONTEXT:
+ * RCU read locked.  The returned partition pointer is valid only
+ * while preemption is disabled.
+ *
+ * RETURNS:
+ * Found partition on success, part0 is returned if no partition matches
+ */
+struct hd_struct *disk_map_sector_rcu(struct gendisk *disk, sector_t sector)
+{
+	struct disk_part_tbl *ptbl;
+	int i;
+
+	ptbl = rcu_dereference(disk->part_tbl);
+
+	for (i = 1; i < ptbl->len; i++) {
+		struct hd_struct *part = rcu_dereference(ptbl->part[i]);
+
+		if (part && part->start_sect <= sector &&
+		    sector < part->start_sect + part->nr_sects)
+			return part;
+	}
+	return &disk->part0;
+}
+EXPORT_SYMBOL_GPL(disk_map_sector_rcu);
+
 /*
  * Can be deleted altogether. Later.
  *
@@ -43,14 +230,14 @@ static inline int major_to_index(int major)
 }
 
 #ifdef CONFIG_PROC_FS
-void blkdev_show(struct seq_file *f, off_t offset)
+void blkdev_show(struct seq_file *seqf, off_t offset)
 {
 	struct blk_major_name *dp;
 
 	if (offset < BLKDEV_MAJOR_HASH_SIZE) {
 		mutex_lock(&block_class_lock);
 		for (dp = major_names[offset]; dp; dp = dp->next)
-			seq_printf(f, "%3d %s\n", dp->major, dp->name);
+			seq_printf(seqf, "%3d %s\n", dp->major, dp->name);
 		mutex_unlock(&block_class_lock);
 	}
 }
@@ -136,6 +323,118 @@ EXPORT_SYMBOL(unregister_blkdev);
 
 static struct kobj_map *bdev_map;
 
+/**
+ * blk_mangle_minor - scatter minor numbers apart
+ * @minor: minor number to mangle
+ *
+ * Scatter consecutively allocated @minor number apart if MANGLE_DEVT
+ * is enabled.  Mangling twice gives the original value.
+ *
+ * RETURNS:
+ * Mangled value.
+ *
+ * CONTEXT:
+ * Don't care.
+ */
+static int blk_mangle_minor(int minor)
+{
+#ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT
+	int i;
+
+	for (i = 0; i < MINORBITS / 2; i++) {
+		int low = minor & (1 << i);
+		int high = minor & (1 << (MINORBITS - 1 - i));
+		int distance = MINORBITS - 1 - 2 * i;
+
+		minor ^= low | high;	/* clear both bits */
+		low <<= distance;	/* swap the positions */
+		high >>= distance;
+		minor |= low | high;	/* and set */
+	}
+#endif
+	return minor;
+}
+
+/**
+ * blk_alloc_devt - allocate a dev_t for a partition
+ * @part: partition to allocate dev_t for
+ * @gfp_mask: memory allocation flag
+ * @devt: out parameter for resulting dev_t
+ *
+ * Allocate a dev_t for block device.
+ *
+ * RETURNS:
+ * 0 on success, allocated dev_t is returned in *@devt.  -errno on
+ * failure.
+ *
+ * CONTEXT:
+ * Might sleep.
+ */
+int blk_alloc_devt(struct hd_struct *part, dev_t *devt)
+{
+	struct gendisk *disk = part_to_disk(part);
+	int idx, rc;
+
+	/* in consecutive minor range? */
+	if (part->partno < disk->minors) {
+		*devt = MKDEV(disk->major, disk->first_minor + part->partno);
+		return 0;
+	}
+
+	/* allocate ext devt */
+	do {
+		if (!idr_pre_get(&ext_devt_idr, GFP_KERNEL))
+			return -ENOMEM;
+		rc = idr_get_new(&ext_devt_idr, part, &idx);
+	} while (rc == -EAGAIN);
+
+	if (rc)
+		return rc;
+
+	if (idx > MAX_EXT_DEVT) {
+		idr_remove(&ext_devt_idr, idx);
+		return -EBUSY;
+	}
+
+	*devt = MKDEV(BLOCK_EXT_MAJOR, blk_mangle_minor(idx));
+	return 0;
+}
+
+/**
+ * blk_free_devt - free a dev_t
+ * @devt: dev_t to free
+ *
+ * Free @devt which was allocated using blk_alloc_devt().
+ *
+ * CONTEXT:
+ * Might sleep.
+ */
+void blk_free_devt(dev_t devt)
+{
+	might_sleep();
+
+	if (devt == MKDEV(0, 0))
+		return;
+
+	if (MAJOR(devt) == BLOCK_EXT_MAJOR) {
+		mutex_lock(&ext_devt_mutex);
+		idr_remove(&ext_devt_idr, blk_mangle_minor(MINOR(devt)));
+		mutex_unlock(&ext_devt_mutex);
+	}
+}
+
+static char *bdevt_str(dev_t devt, char *buf)
+{
+	if (MAJOR(devt) <= 0xff && MINOR(devt) <= 0xff) {
+		char tbuf[BDEVT_SIZE];
+		snprintf(tbuf, BDEVT_SIZE, "%02x%02x", MAJOR(devt), MINOR(devt));
+		snprintf(buf, BDEVT_SIZE, "%-9s", tbuf);
+	} else
+		snprintf(buf, BDEVT_SIZE, "%03x:%05x", MAJOR(devt), MINOR(devt));
+
+	return buf;
+}
+
 /*
  * Register device numbers dev..(dev+range-1)
  * range must be nonzero
@@ -157,11 +456,11 @@ void blk_unregister_region(dev_t devt, unsigned long range)
 
 EXPORT_SYMBOL(blk_unregister_region);
 
-static struct kobject *exact_match(dev_t devt, int *part, void *data)
+static struct kobject *exact_match(dev_t devt, int *partno, void *data)
 {
 	struct gendisk *p = data;
 
-	return &p->dev.kobj;
+	return &disk_to_dev(p)->kobj;
 }
 
 static int exact_lock(dev_t devt, void *data)
@@ -179,21 +478,46 @@ static int exact_lock(dev_t devt, void *data)
  *
  * This function registers the partitioning information in @disk
  * with the kernel.
+ *
+ * FIXME: error handling
  */
 void add_disk(struct gendisk *disk)
 {
 	struct backing_dev_info *bdi;
+	dev_t devt;
 	int retval;
 
+	/* minors == 0 indicates to use ext devt from part0 and should
+	 * be accompanied with EXT_DEVT flag.  Make sure all
+	 * parameters make sense.
+	 */
+	WARN_ON(disk->minors && !(disk->major || disk->first_minor));
+	WARN_ON(!disk->minors && !(disk->flags & GENHD_FL_EXT_DEVT));
+
 	disk->flags |= GENHD_FL_UP;
-	blk_register_region(MKDEV(disk->major, disk->first_minor),
-			    disk->minors, NULL, exact_match, exact_lock, disk);
+
+	retval = blk_alloc_devt(&disk->part0, &devt);
+	if (retval) {
+		WARN_ON(1);
+		return;
+	}
+	disk_to_dev(disk)->devt = devt;
+
+	/* ->major and ->first_minor aren't supposed to be
+	 * dereferenced from here on, but set them just in case.
+	 */
+	disk->major = MAJOR(devt);
+	disk->first_minor = MINOR(devt);
+
+	blk_register_region(disk_devt(disk), disk->minors, NULL,
+			    exact_match, exact_lock, disk);
 	register_disk(disk);
 	blk_register_queue(disk);
 
 	bdi = &disk->queue->backing_dev_info;
-	bdi_register_dev(bdi, MKDEV(disk->major, disk->first_minor));
-	retval = sysfs_create_link(&disk->dev.kobj, &bdi->dev->kobj, "bdi");
+	bdi_register_dev(bdi, disk_devt(disk));
+	retval = sysfs_create_link(&disk_to_dev(disk)->kobj, &bdi->dev->kobj,
+				   "bdi");
 	WARN_ON(retval);
 }
 
@@ -202,78 +526,71 @@ EXPORT_SYMBOL(del_gendisk);	/* in partitions/check.c */
 
 void unlink_gendisk(struct gendisk *disk)
 {
-	sysfs_remove_link(&disk->dev.kobj, "bdi");
+	sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi");
 	bdi_unregister(&disk->queue->backing_dev_info);
 	blk_unregister_queue(disk);
-	blk_unregister_region(MKDEV(disk->major, disk->first_minor),
-			      disk->minors);
+	blk_unregister_region(disk_devt(disk), disk->minors);
 }
 
 /**
  * get_gendisk - get partitioning information for a given device
- * @dev: device to get partitioning information for
+ * @devt: device to get partitioning information for
+ * @part: returned partition index
  *
  * This function gets the structure containing partitioning
- * information for the given device @dev.
+ * information for the given device @devt.
  */
-struct gendisk *get_gendisk(dev_t devt, int *part)
+struct gendisk *get_gendisk(dev_t devt, int *partno)
 {
-	struct kobject *kobj = kobj_lookup(bdev_map, devt, part);
-	struct device *dev = kobj_to_dev(kobj);
+	struct gendisk *disk = NULL;
+
+	if (MAJOR(devt) != BLOCK_EXT_MAJOR) {
+		struct kobject *kobj;
+
+		kobj = kobj_lookup(bdev_map, devt, partno);
+		if (kobj)
+			disk = dev_to_disk(kobj_to_dev(kobj));
+	} else {
+		struct hd_struct *part;
 
-	return  kobj ? dev_to_disk(dev) : NULL;
+		mutex_lock(&ext_devt_mutex);
+		part = idr_find(&ext_devt_idr, blk_mangle_minor(MINOR(devt)));
+		if (part && get_disk(part_to_disk(part))) {
+			*partno = part->partno;
+			disk = part_to_disk(part);
+		}
+		mutex_unlock(&ext_devt_mutex);
+	}
+
+	return disk;
 }
 
-/*
- * print a partitions - intended for places where the root filesystem can't be
- * mounted and thus to give the victim some idea of what went wrong
+/**
+ * bdget_disk - do bdget() by gendisk and partition number
+ * @disk: gendisk of interest
+ * @partno: partition number
+ *
+ * Find partition @partno from @disk, do bdget() on it.
+ *
+ * CONTEXT:
+ * Don't care.
+ *
+ * RETURNS:
+ * Resulting block_device on success, NULL on failure.
  */
-static int printk_partition(struct device *dev, void *data)
+struct block_device *bdget_disk(struct gendisk *disk, int partno)
 {
-	struct gendisk *sgp;
-	char buf[BDEVNAME_SIZE];
-	int n;
-
-	if (dev->type != &disk_type)
-		goto exit;
+	struct hd_struct *part;
+	struct block_device *bdev = NULL;
 
-	sgp = dev_to_disk(dev);
-	/*
-	 * Don't show empty devices or things that have been surpressed
-	 */
-	if (get_capacity(sgp) == 0 ||
-	    (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
-		goto exit;
+	part = disk_get_part(disk, partno);
+	if (part)
+		bdev = bdget(part_devt(part));
+	disk_put_part(part);
 
-	/*
-	 * Note, unlike /proc/partitions, I am showing the numbers in
-	 * hex - the same format as the root= option takes.
-	 */
-	printk("%02x%02x %10llu %s",
-		sgp->major, sgp->first_minor,
-		(unsigned long long)get_capacity(sgp) >> 1,
-		disk_name(sgp, 0, buf));
-	if (sgp->driverfs_dev != NULL &&
-	    sgp->driverfs_dev->driver != NULL)
-		printk(" driver: %s\n",
-			sgp->driverfs_dev->driver->name);
-	else
-		printk(" (driver?)\n");
-
-	/* now show the partitions */
-	for (n = 0; n < sgp->minors - 1; ++n) {
-		if (sgp->part[n] == NULL)
-			goto exit;
-		if (sgp->part[n]->nr_sects == 0)
-			goto exit;
-		printk("  %02x%02x %10llu %s\n",
-			sgp->major, n + 1 + sgp->first_minor,
-			(unsigned long long)sgp->part[n]->nr_sects >> 1,
-			disk_name(sgp, n + 1, buf));
-	}
-exit:
-	return 0;
+	return bdev;
 }
+EXPORT_SYMBOL(bdget_disk);
 
 /*
  * print a full list of all partitions - intended for places where the root
@@ -282,120 +599,145 @@ exit:
  */
 void __init printk_all_partitions(void)
 {
-	mutex_lock(&block_class_lock);
-	class_for_each_device(&block_class, NULL, NULL, printk_partition);
-	mutex_unlock(&block_class_lock);
+	struct class_dev_iter iter;
+	struct device *dev;
+
+	class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
+	while ((dev = class_dev_iter_next(&iter))) {
+		struct gendisk *disk = dev_to_disk(dev);
+		struct disk_part_iter piter;
+		struct hd_struct *part;
+		char name_buf[BDEVNAME_SIZE];
+		char devt_buf[BDEVT_SIZE];
+
+		/*
+		 * Don't show empty devices or things that have been
+		 * surpressed
+		 */
+		if (get_capacity(disk) == 0 ||
+		    (disk->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
+			continue;
+
+		/*
+		 * Note, unlike /proc/partitions, I am showing the
+		 * numbers in hex - the same format as the root=
+		 * option takes.
+		 */
+		disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
+		while ((part = disk_part_iter_next(&piter))) {
+			bool is_part0 = part == &disk->part0;
+
+			printk("%s%s %10llu %s", is_part0 ? "" : "  ",
+			       bdevt_str(part_devt(part), devt_buf),
+			       (unsigned long long)part->nr_sects >> 1,
+			       disk_name(disk, part->partno, name_buf));
+			if (is_part0) {
+				if (disk->driverfs_dev != NULL &&
+				    disk->driverfs_dev->driver != NULL)
+					printk(" driver: %s\n",
+					      disk->driverfs_dev->driver->name);
+				else
+					printk(" (driver?)\n");
+			} else
+				printk("\n");
+		}
+		disk_part_iter_exit(&piter);
+	}
+	class_dev_iter_exit(&iter);
 }
 
 #ifdef CONFIG_PROC_FS
 /* iterator */
-static int find_start(struct device *dev, void *data)
+static void *disk_seqf_start(struct seq_file *seqf, loff_t *pos)
 {
-	loff_t *k = data;
+	loff_t skip = *pos;
+	struct class_dev_iter *iter;
+	struct device *dev;
 
-	if (dev->type != &disk_type)
-		return 0;
-	if (!*k)
-		return 1;
-	(*k)--;
-	return 0;
+	iter = kmalloc(sizeof(*iter), GFP_KERNEL);
+	if (!iter)
+		return ERR_PTR(-ENOMEM);
+
+	seqf->private = iter;
+	class_dev_iter_init(iter, &block_class, NULL, &disk_type);
+	do {
+		dev = class_dev_iter_next(iter);
+		if (!dev)
+			return NULL;
+	} while (skip--);
+
+	return dev_to_disk(dev);
 }
 
-static void *part_start(struct seq_file *part, loff_t *pos)
+static void *disk_seqf_next(struct seq_file *seqf, void *v, loff_t *pos)
 {
 	struct device *dev;
-	loff_t k = *pos;
-
-	if (!k)
-		part->private = (void *)1LU;	/* tell show to print header */
 
-	mutex_lock(&block_class_lock);
-	dev = class_find_device(&block_class, NULL, &k, find_start);
-	if (dev) {
-		put_device(dev);
+	(*pos)++;
+	dev = class_dev_iter_next(seqf->private);
+	if (dev)
 		return dev_to_disk(dev);
-	}
+
 	return NULL;
 }
 
-static int find_next(struct device *dev, void *data)
+static void disk_seqf_stop(struct seq_file *seqf, void *v)
 {
-	if (dev->type == &disk_type)
-		return 1;
-	return 0;
-}
+	struct class_dev_iter *iter = seqf->private;
 
-static void *part_next(struct seq_file *part, void *v, loff_t *pos)
-{
-	struct gendisk *gp = v;
-	struct device *dev;
-	++*pos;
-	dev = class_find_device(&block_class, &gp->dev, NULL, find_next);
-	if (dev) {
-		put_device(dev);
-		return dev_to_disk(dev);
+	/* stop is called even after start failed :-( */
+	if (iter) {
+		class_dev_iter_exit(iter);
+		kfree(iter);
 	}
-	return NULL;
 }
 
-static void part_stop(struct seq_file *part, void *v)
+static void *show_partition_start(struct seq_file *seqf, loff_t *pos)
 {
-	mutex_unlock(&block_class_lock);
+	static void *p;
+
+	p = disk_seqf_start(seqf, pos);
+	if (!IS_ERR(p) && p && !*pos)
+		seq_puts(seqf, "major minor  #blocks  name\n\n");
+	return p;
 }
 
-static int show_partition(struct seq_file *part, void *v)
+static int show_partition(struct seq_file *seqf, void *v)
 {
 	struct gendisk *sgp = v;
-	int n;
+	struct disk_part_iter piter;
+	struct hd_struct *part;
 	char buf[BDEVNAME_SIZE];
 
-	/*
-	 * Print header if start told us to do.  This is to preserve
-	 * the original behavior of not printing header if no
-	 * partition exists.  This hackery will be removed later with
-	 * class iteration clean up.
-	 */
-	if (part->private) {
-		seq_puts(part, "major minor  #blocks  name\n\n");
-		part->private = NULL;
-	}
-
 	/* Don't show non-partitionable removeable devices or empty devices */
-	if (!get_capacity(sgp) ||
-			(sgp->minors == 1 && (sgp->flags & GENHD_FL_REMOVABLE)))
+	if (!get_capacity(sgp) || (!disk_partitionable(sgp) &&
+				   (sgp->flags & GENHD_FL_REMOVABLE)))
 		return 0;
 	if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)
 		return 0;
 
 	/* show the full disk and all non-0 size partitions of it */
-	seq_printf(part, "%4d  %4d %10llu %s\n",
-		sgp->major, sgp->first_minor,
-		(unsigned long long)get_capacity(sgp) >> 1,
-		disk_name(sgp, 0, buf));
-	for (n = 0; n < sgp->minors - 1; n++) {
-		if (!sgp->part[n])
-			continue;
-		if (sgp->part[n]->nr_sects == 0)
-			continue;
-		seq_printf(part, "%4d  %4d %10llu %s\n",
-			sgp->major, n + 1 + sgp->first_minor,
-			(unsigned long long)sgp->part[n]->nr_sects >> 1 ,
-			disk_name(sgp, n + 1, buf));
-	}
+	disk_part_iter_init(&piter, sgp, DISK_PITER_INCL_PART0);
+	while ((part = disk_part_iter_next(&piter)))
+		seq_printf(seqf, "%4d  %7d %10llu %s\n",
+			   MAJOR(part_devt(part)), MINOR(part_devt(part)),
+			   (unsigned long long)part->nr_sects >> 1,
+			   disk_name(sgp, part->partno, buf));
+	disk_part_iter_exit(&piter);
 
 	return 0;
 }
 
 const struct seq_operations partitions_op = {
-	.start	= part_start,
-	.next	= part_next,
-	.stop	= part_stop,
+	.start	= show_partition_start,
+	.next	= disk_seqf_next,
+	.stop	= disk_seqf_stop,
 	.show	= show_partition
 };
 #endif
 
 
-static struct kobject *base_probe(dev_t devt, int *part, void *data)
+static struct kobject *base_probe(dev_t devt, int *partno, void *data)
 {
 	if (request_module("block-major-%d-%d", MAJOR(devt), MINOR(devt)) > 0)
 		/* Make old-style 2.4 aliases work */
@@ -431,29 +773,29 @@ static ssize_t disk_range_show(struct device *dev,
 	return sprintf(buf, "%d\n", disk->minors);
 }
 
-static ssize_t disk_removable_show(struct device *dev,
+static ssize_t disk_ext_range_show(struct device *dev,
 				   struct device_attribute *attr, char *buf)
 {
 	struct gendisk *disk = dev_to_disk(dev);
 
-	return sprintf(buf, "%d\n",
-		       (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0));
+	return sprintf(buf, "%d\n", disk_max_parts(disk));
 }
 
-static ssize_t disk_ro_show(struct device *dev,
+static ssize_t disk_removable_show(struct device *dev,
 				   struct device_attribute *attr, char *buf)
 {
 	struct gendisk *disk = dev_to_disk(dev);
 
-	return sprintf(buf, "%d\n", disk->policy ? 1 : 0);
+	return sprintf(buf, "%d\n",
+		       (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0));
 }
 
-static ssize_t disk_size_show(struct device *dev,
-			      struct device_attribute *attr, char *buf)
+static ssize_t disk_ro_show(struct device *dev,
+				   struct device_attribute *attr, char *buf)
 {
 	struct gendisk *disk = dev_to_disk(dev);
 
-	return sprintf(buf, "%llu\n", (unsigned long long)get_capacity(disk));
+	return sprintf(buf, "%d\n", get_disk_ro(disk) ? 1 : 0);
 }
 
 static ssize_t disk_capability_show(struct device *dev,
@@ -464,73 +806,26 @@ static ssize_t disk_capability_show(struct device *dev,
 	return sprintf(buf, "%x\n", disk->flags);
 }
 
-static ssize_t disk_stat_show(struct device *dev,
-			      struct device_attribute *attr, char *buf)
-{
-	struct gendisk *disk = dev_to_disk(dev);
-
-	preempt_disable();
-	disk_round_stats(disk);
-	preempt_enable();
-	return sprintf(buf,
-		"%8lu %8lu %8llu %8u "
-		"%8lu %8lu %8llu %8u "
-		"%8u %8u %8u"
-		"\n",
-		disk_stat_read(disk, ios[READ]),
-		disk_stat_read(disk, merges[READ]),
-		(unsigned long long)disk_stat_read(disk, sectors[READ]),
-		jiffies_to_msecs(disk_stat_read(disk, ticks[READ])),
-		disk_stat_read(disk, ios[WRITE]),
-		disk_stat_read(disk, merges[WRITE]),
-		(unsigned long long)disk_stat_read(disk, sectors[WRITE]),
-		jiffies_to_msecs(disk_stat_read(disk, ticks[WRITE])),
-		disk->in_flight,
-		jiffies_to_msecs(disk_stat_read(disk, io_ticks)),
-		jiffies_to_msecs(disk_stat_read(disk, time_in_queue)));
-}
-
-#ifdef CONFIG_FAIL_MAKE_REQUEST
-static ssize_t disk_fail_show(struct device *dev,
-			      struct device_attribute *attr, char *buf)
-{
-	struct gendisk *disk = dev_to_disk(dev);
-
-	return sprintf(buf, "%d\n", disk->flags & GENHD_FL_FAIL ? 1 : 0);
-}
-
-static ssize_t disk_fail_store(struct device *dev,
-			       struct device_attribute *attr,
-			       const char *buf, size_t count)
-{
-	struct gendisk *disk = dev_to_disk(dev);
-	int i;
-
-	if (count > 0 && sscanf(buf, "%d", &i) > 0) {
-		if (i == 0)
-			disk->flags &= ~GENHD_FL_FAIL;
-		else
-			disk->flags |= GENHD_FL_FAIL;
-	}
-
-	return count;
-}
-
-#endif
-
 static DEVICE_ATTR(range, S_IRUGO, disk_range_show, NULL);
+static DEVICE_ATTR(ext_range, S_IRUGO, disk_ext_range_show, NULL);
 static DEVICE_ATTR(removable, S_IRUGO, disk_removable_show, NULL);
 static DEVICE_ATTR(ro, S_IRUGO, disk_ro_show, NULL);
-static DEVICE_ATTR(size, S_IRUGO, disk_size_show, NULL);
+static DEVICE_ATTR(size, S_IRUGO, part_size_show, NULL);
 static DEVICE_ATTR(capability, S_IRUGO, disk_capability_show, NULL);
-static DEVICE_ATTR(stat, S_IRUGO, disk_stat_show, NULL);
+static DEVICE_ATTR(stat, S_IRUGO, part_stat_show, NULL);
 #ifdef CONFIG_FAIL_MAKE_REQUEST
 static struct device_attribute dev_attr_fail =
-	__ATTR(make-it-fail, S_IRUGO|S_IWUSR, disk_fail_show, disk_fail_store);
+	__ATTR(make-it-fail, S_IRUGO|S_IWUSR, part_fail_show, part_fail_store);
+#endif
+#ifdef CONFIG_FAIL_IO_TIMEOUT
+static struct device_attribute dev_attr_fail_timeout =
+	__ATTR(io-timeout-fail,  S_IRUGO|S_IWUSR, part_timeout_show,
+		part_timeout_store);
 #endif
 
 static struct attribute *disk_attrs[] = {
 	&dev_attr_range.attr,
+	&dev_attr_ext_range.attr,
 	&dev_attr_removable.attr,
 	&dev_attr_ro.attr,
 	&dev_attr_size.attr,
@@ -539,6 +834,9 @@ static struct attribute *disk_attrs[] = {
 #ifdef CONFIG_FAIL_MAKE_REQUEST
 	&dev_attr_fail.attr,
 #endif
+#ifdef CONFIG_FAIL_IO_TIMEOUT
+	&dev_attr_fail_timeout.attr,
+#endif
 	NULL
 };
 
@@ -551,13 +849,87 @@ static struct attribute_group *disk_attr_groups[] = {
 	NULL
 };
 
+static void disk_free_ptbl_rcu_cb(struct rcu_head *head)
+{
+	struct disk_part_tbl *ptbl =
+		container_of(head, struct disk_part_tbl, rcu_head);
+
+	kfree(ptbl);
+}
+
+/**
+ * disk_replace_part_tbl - replace disk->part_tbl in RCU-safe way
+ * @disk: disk to replace part_tbl for
+ * @new_ptbl: new part_tbl to install
+ *
+ * Replace disk->part_tbl with @new_ptbl in RCU-safe way.  The
+ * original ptbl is freed using RCU callback.
+ *
+ * LOCKING:
+ * Matching bd_mutx locked.
+ */
+static void disk_replace_part_tbl(struct gendisk *disk,
+				  struct disk_part_tbl *new_ptbl)
+{
+	struct disk_part_tbl *old_ptbl = disk->part_tbl;
+
+	rcu_assign_pointer(disk->part_tbl, new_ptbl);
+	if (old_ptbl)
+		call_rcu(&old_ptbl->rcu_head, disk_free_ptbl_rcu_cb);
+}
+
+/**
+ * disk_expand_part_tbl - expand disk->part_tbl
+ * @disk: disk to expand part_tbl for
+ * @partno: expand such that this partno can fit in
+ *
+ * Expand disk->part_tbl such that @partno can fit in.  disk->part_tbl
+ * uses RCU to allow unlocked dereferencing for stats and other stuff.
+ *
+ * LOCKING:
+ * Matching bd_mutex locked, might sleep.
+ *
+ * RETURNS:
+ * 0 on success, -errno on failure.
+ */
+int disk_expand_part_tbl(struct gendisk *disk, int partno)
+{
+	struct disk_part_tbl *old_ptbl = disk->part_tbl;
+	struct disk_part_tbl *new_ptbl;
+	int len = old_ptbl ? old_ptbl->len : 0;
+	int target = partno + 1;
+	size_t size;
+	int i;
+
+	/* disk_max_parts() is zero during initialization, ignore if so */
+	if (disk_max_parts(disk) && target > disk_max_parts(disk))
+		return -EINVAL;
+
+	if (target <= len)
+		return 0;
+
+	size = sizeof(*new_ptbl) + target * sizeof(new_ptbl->part[0]);
+	new_ptbl = kzalloc_node(size, GFP_KERNEL, disk->node_id);
+	if (!new_ptbl)
+		return -ENOMEM;
+
+	INIT_RCU_HEAD(&new_ptbl->rcu_head);
+	new_ptbl->len = target;
+
+	for (i = 0; i < len; i++)
+		rcu_assign_pointer(new_ptbl->part[i], old_ptbl->part[i]);
+
+	disk_replace_part_tbl(disk, new_ptbl);
+	return 0;
+}
+
 static void disk_release(struct device *dev)
 {
 	struct gendisk *disk = dev_to_disk(dev);
 
 	kfree(disk->random);
-	kfree(disk->part);
-	free_disk_stats(disk);
+	disk_replace_part_tbl(disk, NULL);
+	free_part_stats(&disk->part0);
 	kfree(disk);
 }
 struct class block_class = {
@@ -578,83 +950,31 @@ static struct device_type disk_type = {
  * The output looks suspiciously like /proc/partitions with a bunch of
  * extra fields.
  */
-
-static void *diskstats_start(struct seq_file *part, loff_t *pos)
-{
-	struct device *dev;
-	loff_t k = *pos;
-
-	mutex_lock(&block_class_lock);
-	dev = class_find_device(&block_class, NULL, &k, find_start);
-	if (dev) {
-		put_device(dev);
-		return dev_to_disk(dev);
-	}
-	return NULL;
-}
-
-static void *diskstats_next(struct seq_file *part, void *v, loff_t *pos)
-{
-	struct gendisk *gp = v;
-	struct device *dev;
-
-	++*pos;
-	dev = class_find_device(&block_class, &gp->dev, NULL, find_next);
-	if (dev) {
-		put_device(dev);
-		return dev_to_disk(dev);
-	}
-	return NULL;
-}
-
-static void diskstats_stop(struct seq_file *part, void *v)
-{
-	mutex_unlock(&block_class_lock);
-}
-
-static int diskstats_show(struct seq_file *s, void *v)
+static int diskstats_show(struct seq_file *seqf, void *v)
 {
 	struct gendisk *gp = v;
+	struct disk_part_iter piter;
+	struct hd_struct *hd;
 	char buf[BDEVNAME_SIZE];
-	int n = 0;
+	int cpu;
 
 	/*
-	if (&gp->dev.kobj.entry == block_class.devices.next)
-		seq_puts(s,	"major minor name"
+	if (&disk_to_dev(gp)->kobj.entry == block_class.devices.next)
+		seq_puts(seqf,	"major minor name"
 				"     rio rmerge rsect ruse wio wmerge "
 				"wsect wuse running use aveq"
 				"\n\n");
 	*/
  
-	preempt_disable();
-	disk_round_stats(gp);
-	preempt_enable();
-	seq_printf(s, "%4d %4d %s %lu %lu %llu %u %lu %lu %llu %u %u %u %u\n",
-		gp->major, n + gp->first_minor, disk_name(gp, n, buf),
-		disk_stat_read(gp, ios[0]), disk_stat_read(gp, merges[0]),
-		(unsigned long long)disk_stat_read(gp, sectors[0]),
-		jiffies_to_msecs(disk_stat_read(gp, ticks[0])),
-		disk_stat_read(gp, ios[1]), disk_stat_read(gp, merges[1]),
-		(unsigned long long)disk_stat_read(gp, sectors[1]),
-		jiffies_to_msecs(disk_stat_read(gp, ticks[1])),
-		gp->in_flight,
-		jiffies_to_msecs(disk_stat_read(gp, io_ticks)),
-		jiffies_to_msecs(disk_stat_read(gp, time_in_queue)));
-
-	/* now show all non-0 size partitions of it */
-	for (n = 0; n < gp->minors - 1; n++) {
-		struct hd_struct *hd = gp->part[n];
-
-		if (!hd || !hd->nr_sects)
-			continue;
-
-		preempt_disable();
-		part_round_stats(hd);
-		preempt_enable();
-		seq_printf(s, "%4d %4d %s %lu %lu %llu "
+	disk_part_iter_init(&piter, gp, DISK_PITER_INCL_PART0);
+	while ((hd = disk_part_iter_next(&piter))) {
+		cpu = part_stat_lock();
+		part_round_stats(cpu, hd);
+		part_stat_unlock();
+		seq_printf(seqf, "%4d %7d %s %lu %lu %llu "
 			   "%u %lu %lu %llu %u %u %u %u\n",
-			   gp->major, n + gp->first_minor + 1,
-			   disk_name(gp, n + 1, buf),
+			   MAJOR(part_devt(hd)), MINOR(part_devt(hd)),
+			   disk_name(gp, hd->partno, buf),
 			   part_stat_read(hd, ios[0]),
 			   part_stat_read(hd, merges[0]),
 			   (unsigned long long)part_stat_read(hd, sectors[0]),
@@ -668,14 +988,15 @@ static int diskstats_show(struct seq_file *s, void *v)
 			   jiffies_to_msecs(part_stat_read(hd, time_in_queue))
 			);
 	}
+	disk_part_iter_exit(&piter);
  
 	return 0;
 }
 
 const struct seq_operations diskstats_op = {
-	.start	= diskstats_start,
-	.next	= diskstats_next,
-	.stop	= diskstats_stop,
+	.start	= disk_seqf_start,
+	.next	= disk_seqf_next,
+	.stop	= disk_seqf_stop,
 	.show	= diskstats_show
 };
 #endif /* CONFIG_PROC_FS */
@@ -690,7 +1011,7 @@ static void media_change_notify_thread(struct work_struct *work)
 	 * set enviroment vars to indicate which event this is for
 	 * so that user space will know to go check the media status.
 	 */
-	kobject_uevent_env(&gd->dev.kobj, KOBJ_CHANGE, envp);
+	kobject_uevent_env(&disk_to_dev(gd)->kobj, KOBJ_CHANGE, envp);
 	put_device(gd->driverfs_dev);
 }
 
@@ -703,42 +1024,29 @@ void genhd_media_change_notify(struct gendisk *disk)
 EXPORT_SYMBOL_GPL(genhd_media_change_notify);
 #endif  /*  0  */
 
-struct find_block {
-	const char *name;
-	int part;
-};
-
-static int match_id(struct device *dev, void *data)
+dev_t blk_lookup_devt(const char *name, int partno)
 {
-	struct find_block *find = data;
+	dev_t devt = MKDEV(0, 0);
+	struct class_dev_iter iter;
+	struct device *dev;
 
-	if (dev->type != &disk_type)
-		return 0;
-	if (strcmp(dev->bus_id, find->name) == 0) {
+	class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
+	while ((dev = class_dev_iter_next(&iter))) {
 		struct gendisk *disk = dev_to_disk(dev);
-		if (find->part < disk->minors)
-			return 1;
-	}
-	return 0;
-}
+		struct hd_struct *part;
 
-dev_t blk_lookup_devt(const char *name, int part)
-{
-	struct device *dev;
-	dev_t devt = MKDEV(0, 0);
-	struct find_block find;
+		if (strcmp(dev->bus_id, name))
+			continue;
 
-	mutex_lock(&block_class_lock);
-	find.name = name;
-	find.part = part;
-	dev = class_find_device(&block_class, NULL, &find, match_id);
-	if (dev) {
-		put_device(dev);
-		devt = MKDEV(MAJOR(dev->devt),
-			     MINOR(dev->devt) + part);
+		part = disk_get_part(disk, partno);
+		if (part) {
+			devt = part_devt(part);
+			disk_put_part(part);
+			break;
+		}
+		disk_put_part(part);
 	}
-	mutex_unlock(&block_class_lock);
-
+	class_dev_iter_exit(&iter);
 	return devt;
 }
 EXPORT_SYMBOL(blk_lookup_devt);
@@ -747,6 +1055,7 @@ struct gendisk *alloc_disk(int minors)
 {
 	return alloc_disk_node(minors, -1);
 }
+EXPORT_SYMBOL(alloc_disk);
 
 struct gendisk *alloc_disk_node(int minors, int node_id)
 {
@@ -755,32 +1064,28 @@ struct gendisk *alloc_disk_node(int minors, int node_id)
 	disk = kmalloc_node(sizeof(struct gendisk),
 				GFP_KERNEL | __GFP_ZERO, node_id);
 	if (disk) {
-		if (!init_disk_stats(disk)) {
+		if (!init_part_stats(&disk->part0)) {
 			kfree(disk);
 			return NULL;
 		}
-		if (minors > 1) {
-			int size = (minors - 1) * sizeof(struct hd_struct *);
-			disk->part = kmalloc_node(size,
-				GFP_KERNEL | __GFP_ZERO, node_id);
-			if (!disk->part) {
-				free_disk_stats(disk);
-				kfree(disk);
-				return NULL;
-			}
+		if (disk_expand_part_tbl(disk, 0)) {
+			free_part_stats(&disk->part0);
+			kfree(disk);
+			return NULL;
 		}
+		disk->part_tbl->part[0] = &disk->part0;
+
 		disk->minors = minors;
 		rand_initialize_disk(disk);
-		disk->dev.class = &block_class;
-		disk->dev.type = &disk_type;
-		device_initialize(&disk->dev);
+		disk_to_dev(disk)->class = &block_class;
+		disk_to_dev(disk)->type = &disk_type;
+		device_initialize(disk_to_dev(disk));
 		INIT_WORK(&disk->async_notify,
 			media_change_notify_thread);
+		disk->node_id = node_id;
 	}
 	return disk;
 }
-
-EXPORT_SYMBOL(alloc_disk);
 EXPORT_SYMBOL(alloc_disk_node);
 
 struct kobject *get_disk(struct gendisk *disk)
@@ -793,7 +1098,7 @@ struct kobject *get_disk(struct gendisk *disk)
 	owner = disk->fops->owner;
 	if (owner && !try_module_get(owner))
 		return NULL;
-	kobj = kobject_get(&disk->dev.kobj);
+	kobj = kobject_get(&disk_to_dev(disk)->kobj);
 	if (kobj == NULL) {
 		module_put(owner);
 		return NULL;
@@ -807,27 +1112,28 @@ EXPORT_SYMBOL(get_disk);
 void put_disk(struct gendisk *disk)
 {
 	if (disk)
-		kobject_put(&disk->dev.kobj);
+		kobject_put(&disk_to_dev(disk)->kobj);
 }
 
 EXPORT_SYMBOL(put_disk);
 
 void set_device_ro(struct block_device *bdev, int flag)
 {
-	if (bdev->bd_contains != bdev)
-		bdev->bd_part->policy = flag;
-	else
-		bdev->bd_disk->policy = flag;
+	bdev->bd_part->policy = flag;
 }
 
 EXPORT_SYMBOL(set_device_ro);
 
 void set_disk_ro(struct gendisk *disk, int flag)
 {
-	int i;
-	disk->policy = flag;
-	for (i = 0; i < disk->minors - 1; i++)
-		if (disk->part[i]) disk->part[i]->policy = flag;
+	struct disk_part_iter piter;
+	struct hd_struct *part;
+
+	disk_part_iter_init(&piter, disk,
+			    DISK_PITER_INCL_EMPTY | DISK_PITER_INCL_PART0);
+	while ((part = disk_part_iter_next(&piter)))
+		part->policy = flag;
+	disk_part_iter_exit(&piter);
 }
 
 EXPORT_SYMBOL(set_disk_ro);
@@ -836,18 +1142,15 @@ int bdev_read_only(struct block_device *bdev)
 {
 	if (!bdev)
 		return 0;
-	else if (bdev->bd_contains != bdev)
-		return bdev->bd_part->policy;
-	else
-		return bdev->bd_disk->policy;
+	return bdev->bd_part->policy;
 }
 
 EXPORT_SYMBOL(bdev_read_only);
 
-int invalidate_partition(struct gendisk *disk, int index)
+int invalidate_partition(struct gendisk *disk, int partno)
 {
 	int res = 0;
-	struct block_device *bdev = bdget_disk(disk, index);
+	struct block_device *bdev = bdget_disk(disk, partno);
 	if (bdev) {
 		fsync_bdev(bdev);
 		res = __invalidate_device(bdev);
diff --git a/block/ioctl.c b/block/ioctl.c
index 77185e5c026..38bee321e1f 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -12,11 +12,12 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user
 {
 	struct block_device *bdevp;
 	struct gendisk *disk;
+	struct hd_struct *part;
 	struct blkpg_ioctl_arg a;
 	struct blkpg_partition p;
+	struct disk_part_iter piter;
 	long long start, length;
-	int part;
-	int i;
+	int partno;
 	int err;
 
 	if (!capable(CAP_SYS_ADMIN))
@@ -28,8 +29,8 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user
 	disk = bdev->bd_disk;
 	if (bdev != bdev->bd_contains)
 		return -EINVAL;
-	part = p.pno;
-	if (part <= 0 || part >= disk->minors)
+	partno = p.pno;
+	if (partno <= 0)
 		return -EINVAL;
 	switch (a.op) {
 		case BLKPG_ADD_PARTITION:
@@ -43,36 +44,37 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user
 				    || pstart < 0 || plength < 0)
 					return -EINVAL;
 			}
-			/* partition number in use? */
+
 			mutex_lock(&bdev->bd_mutex);
-			if (disk->part[part - 1]) {
-				mutex_unlock(&bdev->bd_mutex);
-				return -EBUSY;
-			}
-			/* overlap? */
-			for (i = 0; i < disk->minors - 1; i++) {
-				struct hd_struct *s = disk->part[i];
 
-				if (!s)
-					continue;
-				if (!(start+length <= s->start_sect ||
-				      start >= s->start_sect + s->nr_sects)) {
+			/* overlap? */
+			disk_part_iter_init(&piter, disk,
+					    DISK_PITER_INCL_EMPTY);
+			while ((part = disk_part_iter_next(&piter))) {
+				if (!(start + length <= part->start_sect ||
+				      start >= part->start_sect + part->nr_sects)) {
+					disk_part_iter_exit(&piter);
 					mutex_unlock(&bdev->bd_mutex);
 					return -EBUSY;
 				}
 			}
+			disk_part_iter_exit(&piter);
+
 			/* all seems OK */
-			err = add_partition(disk, part, start, length, ADDPART_FLAG_NONE);
+			err = add_partition(disk, partno, start, length,
+					    ADDPART_FLAG_NONE);
 			mutex_unlock(&bdev->bd_mutex);
 			return err;
 		case BLKPG_DEL_PARTITION:
-			if (!disk->part[part-1])
-				return -ENXIO;
-			if (disk->part[part - 1]->nr_sects == 0)
+			part = disk_get_part(disk, partno);
+			if (!part)
 				return -ENXIO;
-			bdevp = bdget_disk(disk, part);
+
+			bdevp = bdget(part_devt(part));
+			disk_put_part(part);
 			if (!bdevp)
 				return -ENOMEM;
+
 			mutex_lock(&bdevp->bd_mutex);
 			if (bdevp->bd_openers) {
 				mutex_unlock(&bdevp->bd_mutex);
@@ -84,7 +86,7 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user
 			invalidate_bdev(bdevp);
 
 			mutex_lock_nested(&bdev->bd_mutex, 1);
-			delete_partition(disk, part);
+			delete_partition(disk, partno);
 			mutex_unlock(&bdev->bd_mutex);
 			mutex_unlock(&bdevp->bd_mutex);
 			bdput(bdevp);
@@ -100,7 +102,7 @@ static int blkdev_reread_part(struct block_device *bdev)
 	struct gendisk *disk = bdev->bd_disk;
 	int res;
 
-	if (disk->minors == 1 || bdev != bdev->bd_contains)
+	if (!disk_partitionable(disk) || bdev != bdev->bd_contains)
 		return -EINVAL;
 	if (!capable(CAP_SYS_ADMIN))
 		return -EACCES;
@@ -111,6 +113,69 @@ static int blkdev_reread_part(struct block_device *bdev)
 	return res;
 }
 
+static void blk_ioc_discard_endio(struct bio *bio, int err)
+{
+	if (err) {
+		if (err == -EOPNOTSUPP)
+			set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
+		clear_bit(BIO_UPTODATE, &bio->bi_flags);
+	}
+	complete(bio->bi_private);
+}
+
+static int blk_ioctl_discard(struct block_device *bdev, uint64_t start,
+			     uint64_t len)
+{
+	struct request_queue *q = bdev_get_queue(bdev);
+	int ret = 0;
+
+	if (start & 511)
+		return -EINVAL;
+	if (len & 511)
+		return -EINVAL;
+	start >>= 9;
+	len >>= 9;
+
+	if (start + len > (bdev->bd_inode->i_size >> 9))
+		return -EINVAL;
+
+	if (!q->prepare_discard_fn)
+		return -EOPNOTSUPP;
+
+	while (len && !ret) {
+		DECLARE_COMPLETION_ONSTACK(wait);
+		struct bio *bio;
+
+		bio = bio_alloc(GFP_KERNEL, 0);
+		if (!bio)
+			return -ENOMEM;
+
+		bio->bi_end_io = blk_ioc_discard_endio;
+		bio->bi_bdev = bdev;
+		bio->bi_private = &wait;
+		bio->bi_sector = start;
+
+		if (len > q->max_hw_sectors) {
+			bio->bi_size = q->max_hw_sectors << 9;
+			len -= q->max_hw_sectors;
+			start += q->max_hw_sectors;
+		} else {
+			bio->bi_size = len << 9;
+			len = 0;
+		}
+		submit_bio(DISCARD_NOBARRIER, bio);
+
+		wait_for_completion(&wait);
+
+		if (bio_flagged(bio, BIO_EOPNOTSUPP))
+			ret = -EOPNOTSUPP;
+		else if (!bio_flagged(bio, BIO_UPTODATE))
+			ret = -EIO;
+		bio_put(bio);
+	}
+	return ret;
+}
+
 static int put_ushort(unsigned long arg, unsigned short val)
 {
 	return put_user(val, (unsigned short __user *)arg);
@@ -258,6 +323,19 @@ int blkdev_ioctl(struct inode *inode, struct file *file, unsigned cmd,
 		set_device_ro(bdev, n);
 		unlock_kernel();
 		return 0;
+
+	case BLKDISCARD: {
+		uint64_t range[2];
+
+		if (!(file->f_mode & FMODE_WRITE))
+			return -EBADF;
+
+		if (copy_from_user(range, (void __user *)arg, sizeof(range)))
+			return -EFAULT;
+
+		return blk_ioctl_discard(bdev, range[0], range[1]);
+	}
+
 	case HDIO_GETGEO: {
 		struct hd_geometry geo;
 
diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
index ec4b7f23462..c34272a348f 100644
--- a/block/scsi_ioctl.c
+++ b/block/scsi_ioctl.c
@@ -185,6 +185,7 @@ void blk_set_cmd_filter_defaults(struct blk_cmd_filter *filter)
 	__set_bit(GPCMD_PREVENT_ALLOW_MEDIUM_REMOVAL, filter->write_ok);
 	__set_bit(GPCMD_LOAD_UNLOAD, filter->write_ok);
 	__set_bit(GPCMD_SET_STREAMING, filter->write_ok);
+	__set_bit(GPCMD_SET_READ_AHEAD, filter->write_ok);
 }
 EXPORT_SYMBOL_GPL(blk_set_cmd_filter_defaults);
 
@@ -313,11 +314,12 @@ static int sg_io(struct file *file, struct request_queue *q,
 			goto out;
 		}
 
-		ret = blk_rq_map_user_iov(q, rq, iov, hdr->iovec_count,
-					  hdr->dxfer_len);
+		ret = blk_rq_map_user_iov(q, rq, NULL, iov, hdr->iovec_count,
+					  hdr->dxfer_len, GFP_KERNEL);
 		kfree(iov);
 	} else if (hdr->dxfer_len)
-		ret = blk_rq_map_user(q, rq, hdr->dxferp, hdr->dxfer_len);
+		ret = blk_rq_map_user(q, rq, NULL, hdr->dxferp, hdr->dxfer_len,
+				      GFP_KERNEL);
 
 	if (ret)
 		goto out;
diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index f2dd99122bd..a93247cc395 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -33,6 +33,7 @@
  */
 
 #include <linux/kernel.h>
+#include <linux/blkdev.h>
 #include <linux/pci.h>
 #include <scsi/scsi.h>
 #include <scsi/scsi_host.h>
@@ -459,29 +460,29 @@ static void ata_eh_clear_action(struct ata_link *link, struct ata_device *dev,
  *	RETURNS:
  *	EH_HANDLED or EH_NOT_HANDLED
  */
-enum scsi_eh_timer_return ata_scsi_timed_out(struct scsi_cmnd *cmd)
+enum blk_eh_timer_return ata_scsi_timed_out(struct scsi_cmnd *cmd)
 {
 	struct Scsi_Host *host = cmd->device->host;
 	struct ata_port *ap = ata_shost_to_port(host);
 	unsigned long flags;
 	struct ata_queued_cmd *qc;
-	enum scsi_eh_timer_return ret;
+	enum blk_eh_timer_return ret;
 
 	DPRINTK("ENTER\n");
 
 	if (ap->ops->error_handler) {
-		ret = EH_NOT_HANDLED;
+		ret = BLK_EH_NOT_HANDLED;
 		goto out;
 	}
 
-	ret = EH_HANDLED;
+	ret = BLK_EH_HANDLED;
 	spin_lock_irqsave(ap->lock, flags);
 	qc = ata_qc_from_tag(ap, ap->link.active_tag);
 	if (qc) {
 		WARN_ON(qc->scsicmd != cmd);
 		qc->flags |= ATA_QCFLAG_EH_SCHEDULED;
 		qc->err_mask |= AC_ERR_TIMEOUT;
-		ret = EH_NOT_HANDLED;
+		ret = BLK_EH_NOT_HANDLED;
 	}
 	spin_unlock_irqrestore(ap->lock, flags);
 
@@ -833,7 +834,7 @@ void ata_qc_schedule_eh(struct ata_queued_cmd *qc)
 	 * Note that ATA_QCFLAG_FAILED is unconditionally set after
 	 * this function completes.
 	 */
-	scsi_req_abort_cmd(qc->scsicmd);
+	blk_abort_request(qc->scsicmd->request);
 }
 
 /**
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index fccd5e496c6..59fe051957e 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -1085,6 +1085,10 @@ static int ata_scsi_dev_config(struct scsi_device *sdev,
 
 		blk_queue_dma_drain(q, atapi_drain_needed, buf, ATAPI_MAX_DRAIN);
 	} else {
+		if (ata_id_is_ssd(dev->id))
+			queue_flag_set_unlocked(QUEUE_FLAG_NONROT,
+						sdev->request_queue);
+
 		/* ATA devices must be sector aligned */
 		blk_queue_update_dma_alignment(sdev->request_queue,
 					       ATA_SECT_SIZE - 1);
diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
index e96de96e302..fe2839e5877 100644
--- a/drivers/ata/libata.h
+++ b/drivers/ata/libata.h
@@ -155,7 +155,7 @@ extern int ata_bus_probe(struct ata_port *ap);
 /* libata-eh.c */
 extern unsigned long ata_internal_cmd_timeout(struct ata_device *dev, u8 cmd);
 extern void ata_internal_cmd_timed_out(struct ata_device *dev, u8 cmd);
-extern enum scsi_eh_timer_return ata_scsi_timed_out(struct scsi_cmnd *cmd);
+extern enum blk_eh_timer_return ata_scsi_timed_out(struct scsi_cmnd *cmd);
 extern void ata_scsi_error(struct Scsi_Host *host);
 extern void ata_port_wait_eh(struct ata_port *ap);
 extern void ata_eh_fastdrain_timerfn(unsigned long arg);
diff --git a/drivers/base/base.h b/drivers/base/base.h
index 31dc0cd84af..0a5f055dffb 100644
--- a/drivers/base/base.h
+++ b/drivers/base/base.h
@@ -54,7 +54,7 @@ struct driver_private {
  */
 struct class_private {
 	struct kset class_subsys;
-	struct list_head class_devices;
+	struct klist class_devices;
 	struct list_head class_interfaces;
 	struct kset class_dirs;
 	struct mutex class_mutex;
diff --git a/drivers/base/class.c b/drivers/base/class.c
index cc5e28c8885..eb85e431230 100644
--- a/drivers/base/class.c
+++ b/drivers/base/class.c
@@ -135,6 +135,20 @@ static void remove_class_attrs(struct class *cls)
 	}
 }
 
+static void klist_class_dev_get(struct klist_node *n)
+{
+	struct device *dev = container_of(n, struct device, knode_class);
+
+	get_device(dev);
+}
+
+static void klist_class_dev_put(struct klist_node *n)
+{
+	struct device *dev = container_of(n, struct device, knode_class);
+
+	put_device(dev);
+}
+
 int __class_register(struct class *cls, struct lock_class_key *key)
 {
 	struct class_private *cp;
@@ -145,7 +159,7 @@ int __class_register(struct class *cls, struct lock_class_key *key)
 	cp = kzalloc(sizeof(*cp), GFP_KERNEL);
 	if (!cp)
 		return -ENOMEM;
-	INIT_LIST_HEAD(&cp->class_devices);
+	klist_init(&cp->class_devices, klist_class_dev_get, klist_class_dev_put);
 	INIT_LIST_HEAD(&cp->class_interfaces);
 	kset_init(&cp->class_dirs);
 	__mutex_init(&cp->class_mutex, "struct class mutex", key);
@@ -269,6 +283,71 @@ char *make_class_name(const char *name, struct kobject *kobj)
 #endif
 
 /**
+ * class_dev_iter_init - initialize class device iterator
+ * @iter: class iterator to initialize
+ * @class: the class we wanna iterate over
+ * @start: the device to start iterating from, if any
+ * @type: device_type of the devices to iterate over, NULL for all
+ *
+ * Initialize class iterator @iter such that it iterates over devices
+ * of @class.  If @start is set, the list iteration will start there,
+ * otherwise if it is NULL, the iteration starts at the beginning of
+ * the list.
+ */
+void class_dev_iter_init(struct class_dev_iter *iter, struct class *class,
+			 struct device *start, const struct device_type *type)
+{
+	struct klist_node *start_knode = NULL;
+
+	if (start)
+		start_knode = &start->knode_class;
+	klist_iter_init_node(&class->p->class_devices, &iter->ki, start_knode);
+	iter->type = type;
+}
+EXPORT_SYMBOL_GPL(class_dev_iter_init);
+
+/**
+ * class_dev_iter_next - iterate to the next device
+ * @iter: class iterator to proceed
+ *
+ * Proceed @iter to the next device and return it.  Returns NULL if
+ * iteration is complete.
+ *
+ * The returned device is referenced and won't be released till
+ * iterator is proceed to the next device or exited.  The caller is
+ * free to do whatever it wants to do with the device including
+ * calling back into class code.
+ */
+struct device *class_dev_iter_next(struct class_dev_iter *iter)
+{
+	struct klist_node *knode;
+	struct device *dev;
+
+	while (1) {
+		knode = klist_next(&iter->ki);
+		if (!knode)
+			return NULL;
+		dev = container_of(knode, struct device, knode_class);
+		if (!iter->type || iter->type == dev->type)
+			return dev;
+	}
+}
+EXPORT_SYMBOL_GPL(class_dev_iter_next);
+
+/**
+ * class_dev_iter_exit - finish iteration
+ * @iter: class iterator to finish
+ *
+ * Finish an iteration.  Always call this function after iteration is
+ * complete whether the iteration ran till the end or not.
+ */
+void class_dev_iter_exit(struct class_dev_iter *iter)
+{
+	klist_iter_exit(&iter->ki);
+}
+EXPORT_SYMBOL_GPL(class_dev_iter_exit);
+
+/**
  * class_for_each_device - device iterator
  * @class: the class we're iterating
  * @start: the device to start with in the list, if any.
@@ -283,13 +362,13 @@ char *make_class_name(const char *name, struct kobject *kobj)
  * We check the return of @fn each time. If it returns anything
  * other than 0, we break out and return that value.
  *
- * Note, we hold class->class_mutex in this function, so it can not be
- * re-acquired in @fn, otherwise it will self-deadlocking. For
- * example, calls to add or remove class members would be verboten.
+ * @fn is allowed to do anything including calling back into class
+ * code.  There's no locking restriction.
  */
 int class_for_each_device(struct class *class, struct device *start,
 			  void *data, int (*fn)(struct device *, void *))
 {
+	struct class_dev_iter iter;
 	struct device *dev;
 	int error = 0;
 
@@ -301,20 +380,13 @@ int class_for_each_device(struct class *class, struct device *start,
 		return -EINVAL;
 	}
 
-	mutex_lock(&class->p->class_mutex);
-	list_for_each_entry(dev, &class->p->class_devices, node) {
-		if (start) {
-			if (start == dev)
-				start = NULL;
-			continue;
-		}
-		dev = get_device(dev);
+	class_dev_iter_init(&iter, class, start, NULL);
+	while ((dev = class_dev_iter_next(&iter))) {
 		error = fn(dev, data);
-		put_device(dev);
 		if (error)
 			break;
 	}
-	mutex_unlock(&class->p->class_mutex);
+	class_dev_iter_exit(&iter);
 
 	return error;
 }
@@ -337,16 +409,15 @@ EXPORT_SYMBOL_GPL(class_for_each_device);
  *
  * Note, you will need to drop the reference with put_device() after use.
  *
- * We hold class->class_mutex in this function, so it can not be
- * re-acquired in @match, otherwise it will self-deadlocking. For
- * example, calls to add or remove class members would be verboten.
+ * @fn is allowed to do anything including calling back into class
+ * code.  There's no locking restriction.
  */
 struct device *class_find_device(struct class *class, struct device *start,
 				 void *data,
 				 int (*match)(struct device *, void *))
 {
+	struct class_dev_iter iter;
 	struct device *dev;
-	int found = 0;
 
 	if (!class)
 		return NULL;
@@ -356,29 +427,23 @@ struct device *class_find_device(struct class *class, struct device *start,
 		return NULL;
 	}
 
-	mutex_lock(&class->p->class_mutex);
-	list_for_each_entry(dev, &class->p->class_devices, node) {
-		if (start) {
-			if (start == dev)
-				start = NULL;
-			continue;
-		}
-		dev = get_device(dev);
+	class_dev_iter_init(&iter, class, start, NULL);
+	while ((dev = class_dev_iter_next(&iter))) {
 		if (match(dev, data)) {
-			found = 1;
+			get_device(dev);
 			break;
-		} else
-			put_device(dev);
+		}
 	}
-	mutex_unlock(&class->p->class_mutex);
+	class_dev_iter_exit(&iter);
 
-	return found ? dev : NULL;
+	return dev;
 }
 EXPORT_SYMBOL_GPL(class_find_device);
 
 int class_interface_register(struct class_interface *class_intf)
 {
 	struct class *parent;
+	struct class_dev_iter iter;
 	struct device *dev;
 
 	if (!class_intf || !class_intf->class)
@@ -391,8 +456,10 @@ int class_interface_register(struct class_interface *class_intf)
 	mutex_lock(&parent->p->class_mutex);
 	list_add_tail(&class_intf->node, &parent->p->class_interfaces);
 	if (class_intf->add_dev) {
-		list_for_each_entry(dev, &parent->p->class_devices, node)
+		class_dev_iter_init(&iter, parent, NULL, NULL);
+		while ((dev = class_dev_iter_next(&iter)))
 			class_intf->add_dev(dev, class_intf);
+		class_dev_iter_exit(&iter);
 	}
 	mutex_unlock(&parent->p->class_mutex);
 
@@ -402,6 +469,7 @@ int class_interface_register(struct class_interface *class_intf)
 void class_interface_unregister(struct class_interface *class_intf)
 {
 	struct class *parent = class_intf->class;
+	struct class_dev_iter iter;
 	struct device *dev;
 
 	if (!parent)
@@ -410,8 +478,10 @@ void class_interface_unregister(struct class_interface *class_intf)
 	mutex_lock(&parent->p->class_mutex);
 	list_del_init(&class_intf->node);
 	if (class_intf->remove_dev) {
-		list_for_each_entry(dev, &parent->p->class_devices, node)
+		class_dev_iter_init(&iter, parent, NULL, NULL);
+		while ((dev = class_dev_iter_next(&iter)))
 			class_intf->remove_dev(dev, class_intf);
+		class_dev_iter_exit(&iter);
 	}
 	mutex_unlock(&parent->p->class_mutex);
 
diff --git a/drivers/base/core.c b/drivers/base/core.c
index d021c98605b..b98cb1416a2 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -536,7 +536,6 @@ void device_initialize(struct device *dev)
 	klist_init(&dev->klist_children, klist_children_get,
 		   klist_children_put);
 	INIT_LIST_HEAD(&dev->dma_pools);
-	INIT_LIST_HEAD(&dev->node);
 	init_MUTEX(&dev->sem);
 	spin_lock_init(&dev->devres_lock);
 	INIT_LIST_HEAD(&dev->devres_head);
@@ -916,7 +915,8 @@ int device_add(struct device *dev)
 	if (dev->class) {
 		mutex_lock(&dev->class->p->class_mutex);
 		/* tie the class to the device */
-		list_add_tail(&dev->node, &dev->class->p->class_devices);
+		klist_add_tail(&dev->knode_class,
+			       &dev->class->p->class_devices);
 
 		/* notify any interfaces that the device is here */
 		list_for_each_entry(class_intf,
@@ -1032,7 +1032,7 @@ void device_del(struct device *dev)
 			if (class_intf->remove_dev)
 				class_intf->remove_dev(dev, class_intf);
 		/* remove the device from the class list */
-		list_del_init(&dev->node);
+		klist_del(&dev->knode_class);
 		mutex_unlock(&dev->class->p->class_mutex);
 	}
 	device_remove_file(dev, &uevent_attr);
diff --git a/drivers/block/aoe/aoeblk.c b/drivers/block/aoe/aoeblk.c
index 0c39782b266..aa69556c348 100644
--- a/drivers/block/aoe/aoeblk.c
+++ b/drivers/block/aoe/aoeblk.c
@@ -109,12 +109,12 @@ static const struct attribute_group attr_group = {
 static int
 aoedisk_add_sysfs(struct aoedev *d)
 {
-	return sysfs_create_group(&d->gd->dev.kobj, &attr_group);
+	return sysfs_create_group(&disk_to_dev(d->gd)->kobj, &attr_group);
 }
 void
 aoedisk_rm_sysfs(struct aoedev *d)
 {
-	sysfs_remove_group(&d->gd->dev.kobj, &attr_group);
+	sysfs_remove_group(&disk_to_dev(d->gd)->kobj, &attr_group);
 }
 
 static int
@@ -276,7 +276,7 @@ aoeblk_gdalloc(void *vp)
 	gd->first_minor = d->sysminor * AOE_PARTITIONS;
 	gd->fops = &aoe_bdops;
 	gd->private_data = d;
-	gd->capacity = d->ssize;
+	set_capacity(gd, d->ssize);
 	snprintf(gd->disk_name, sizeof gd->disk_name, "etherd/e%ld.%d",
 		d->aoemajor, d->aoeminor);
 
diff --git a/drivers/block/aoe/aoecmd.c b/drivers/block/aoe/aoecmd.c
index 2f1746295d0..961d29a53ca 100644
--- a/drivers/block/aoe/aoecmd.c
+++ b/drivers/block/aoe/aoecmd.c
@@ -645,7 +645,7 @@ aoecmd_sleepwork(struct work_struct *work)
 		unsigned long flags;
 		u64 ssize;
 
-		ssize = d->gd->capacity;
+		ssize = get_capacity(d->gd);
 		bd = bdget_disk(d->gd, 0);
 
 		if (bd) {
@@ -707,7 +707,7 @@ ataid_complete(struct aoedev *d, struct aoetgt *t, unsigned char *id)
 	if (d->flags & (DEVFL_GDALLOC|DEVFL_NEWSIZE))
 		return;
 	if (d->gd != NULL) {
-		d->gd->capacity = ssize;
+		set_capacity(d->gd, ssize);
 		d->flags |= DEVFL_NEWSIZE;
 	} else
 		d->flags |= DEVFL_GDALLOC;
@@ -756,12 +756,17 @@ diskstats(struct gendisk *disk, struct bio *bio, ulong duration, sector_t sector
 	unsigned long n_sect = bio->bi_size >> 9;
 	const int rw = bio_data_dir(bio);
 	struct hd_struct *part;
+	int cpu;
 
-	part = get_part(disk, sector);
-	all_stat_inc(disk, part, ios[rw], sector);
-	all_stat_add(disk, part, ticks[rw], duration, sector);
-	all_stat_add(disk, part, sectors[rw], n_sect, sector);
-	all_stat_add(disk, part, io_ticks, duration, sector);
+	cpu = part_stat_lock();
+	part = disk_map_sector_rcu(disk, sector);
+
+	part_stat_inc(cpu, part, ios[rw]);
+	part_stat_add(cpu, part, ticks[rw], duration);
+	part_stat_add(cpu, part, sectors[rw], n_sect);
+	part_stat_add(cpu, part, io_ticks, duration);
+
+	part_stat_unlock();
 }
 
 void
diff --git a/drivers/block/aoe/aoedev.c b/drivers/block/aoe/aoedev.c
index a1d813ab0d6..6a8038d115b 100644
--- a/drivers/block/aoe/aoedev.c
+++ b/drivers/block/aoe/aoedev.c
@@ -91,7 +91,7 @@ aoedev_downdev(struct aoedev *d)
 	}
 
 	if (d->gd)
-		d->gd->capacity = 0;
+		set_capacity(d->gd, 0);
 
 	d->flags &= ~DEVFL_UP;
 }
diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
index b73116ef923..1e1f9153000 100644
--- a/drivers/block/cciss.c
+++ b/drivers/block/cciss.c
@@ -3460,8 +3460,8 @@ static int __devinit cciss_init_one(struct pci_dev *pdev,
 	       hba[i]->intr[SIMPLE_MODE_INT], dac ? "" : " not");
 
 	hba[i]->cmd_pool_bits =
-	    kmalloc(((hba[i]->nr_cmds + BITS_PER_LONG -
-		      1) / BITS_PER_LONG) * sizeof(unsigned long), GFP_KERNEL);
+	    kmalloc(DIV_ROUND_UP(hba[i]->nr_cmds, BITS_PER_LONG)
+			* sizeof(unsigned long), GFP_KERNEL);
 	hba[i]->cmd_pool = (CommandList_struct *)
 	    pci_alloc_consistent(hba[i]->pdev,
 		    hba[i]->nr_cmds * sizeof(CommandList_struct),
@@ -3493,8 +3493,8 @@ static int __devinit cciss_init_one(struct pci_dev *pdev,
 	/* command and error info recs zeroed out before
 	   they are used */
 	memset(hba[i]->cmd_pool_bits, 0,
-	       ((hba[i]->nr_cmds + BITS_PER_LONG -
-		 1) / BITS_PER_LONG) * sizeof(unsigned long));
+	       DIV_ROUND_UP(hba[i]->nr_cmds, BITS_PER_LONG)
+			* sizeof(unsigned long));
 
 	hba[i]->num_luns = 0;
 	hba[i]->highest_lun = -1;
diff --git a/drivers/block/cciss_scsi.c b/drivers/block/cciss_scsi.c
index e1233aabda7..a3fd87b4144 100644
--- a/drivers/block/cciss_scsi.c
+++ b/drivers/block/cciss_scsi.c
@@ -365,7 +365,7 @@ struct scsi2map {
 
 static int 
 cciss_scsi_add_entry(int ctlr, int hostno, 
-		unsigned char *scsi3addr, int devtype,
+		struct cciss_scsi_dev_t *device,
 		struct scsi2map *added, int *nadded)
 {
 	/* assumes hba[ctlr]->scsi_ctlr->lock is held */ 
@@ -384,12 +384,12 @@ cciss_scsi_add_entry(int ctlr, int hostno,
 	lun = 0;
 	/* Is this device a non-zero lun of a multi-lun device */
 	/* byte 4 of the 8-byte LUN addr will contain the logical unit no. */
-	if (scsi3addr[4] != 0) {
+	if (device->scsi3addr[4] != 0) {
 		/* Search through our list and find the device which */
 		/* has the same 8 byte LUN address, excepting byte 4. */
 		/* Assign the same bus and target for this new LUN. */
 		/* Use the logical unit number from the firmware. */
-		memcpy(addr1, scsi3addr, 8);
+		memcpy(addr1, device->scsi3addr, 8);
 		addr1[4] = 0;
 		for (i = 0; i < n; i++) {
 			sd = &ccissscsi[ctlr].dev[i];
@@ -399,7 +399,7 @@ cciss_scsi_add_entry(int ctlr, int hostno,
 			if (memcmp(addr1, addr2, 8) == 0) {
 				bus = sd->bus;
 				target = sd->target;
-				lun = scsi3addr[4];
+				lun = device->scsi3addr[4];
 				break;
 			}
 		}
@@ -420,8 +420,12 @@ cciss_scsi_add_entry(int ctlr, int hostno,
 	added[*nadded].lun = sd->lun;
 	(*nadded)++;
 
-	memcpy(&sd->scsi3addr[0], scsi3addr, 8);
-	sd->devtype = devtype;
+	memcpy(sd->scsi3addr, device->scsi3addr, 8);
+	memcpy(sd->vendor, device->vendor, sizeof(sd->vendor));
+	memcpy(sd->revision, device->revision, sizeof(sd->revision));
+	memcpy(sd->device_id, device->device_id, sizeof(sd->device_id));
+	sd->devtype = device->devtype;
+
 	ccissscsi[ctlr].ndevices++;
 
 	/* initially, (before registering with scsi layer) we don't 
@@ -487,6 +491,22 @@ static void fixup_botched_add(int ctlr, char *scsi3addr)
 	CPQ_TAPE_UNLOCK(ctlr, flags);
 }
 
+static int device_is_the_same(struct cciss_scsi_dev_t *dev1,
+	struct cciss_scsi_dev_t *dev2)
+{
+	return dev1->devtype == dev2->devtype &&
+		memcmp(dev1->scsi3addr, dev2->scsi3addr,
+			sizeof(dev1->scsi3addr)) == 0 &&
+		memcmp(dev1->device_id, dev2->device_id,
+			sizeof(dev1->device_id)) == 0 &&
+		memcmp(dev1->vendor, dev2->vendor,
+			sizeof(dev1->vendor)) == 0 &&
+		memcmp(dev1->model, dev2->model,
+			sizeof(dev1->model)) == 0 &&
+		memcmp(dev1->revision, dev2->revision,
+			sizeof(dev1->revision)) == 0;
+}
+
 static int
 adjust_cciss_scsi_table(int ctlr, int hostno,
 	struct cciss_scsi_dev_t sd[], int nsds)
@@ -532,7 +552,7 @@ adjust_cciss_scsi_table(int ctlr, int hostno,
 		for (j=0;j<nsds;j++) {
 			if (SCSI3ADDR_EQ(sd[j].scsi3addr,
 				csd->scsi3addr)) {
-				if (sd[j].devtype == csd->devtype)
+				if (device_is_the_same(&sd[j], csd))
 					found=2;
 				else
 					found=1;
@@ -548,22 +568,26 @@ adjust_cciss_scsi_table(int ctlr, int hostno,
 			cciss_scsi_remove_entry(ctlr, hostno, i,
 				removed, &nremoved);
 			/* remove ^^^, hence i not incremented */
-		} 
-		else if (found == 1) { /* device is different kind */
+		} else if (found == 1) { /* device is different in some way */
 			changes++;
-			printk("cciss%d: device c%db%dt%dl%d type changed "
-				"(device type now %s).\n",
-				ctlr, hostno, csd->bus, csd->target, csd->lun,
-					scsi_device_type(csd->devtype));
+			printk("cciss%d: device c%db%dt%dl%d has changed.\n",
+				ctlr, hostno, csd->bus, csd->target, csd->lun);
 			cciss_scsi_remove_entry(ctlr, hostno, i,
 				removed, &nremoved);
 			/* remove ^^^, hence i not incremented */
-			if (cciss_scsi_add_entry(ctlr, hostno,
-				&sd[j].scsi3addr[0], sd[j].devtype,
+			if (cciss_scsi_add_entry(ctlr, hostno, &sd[j],
 				added, &nadded) != 0)
 				/* we just removed one, so add can't fail. */
 					BUG();
 			csd->devtype = sd[j].devtype;
+			memcpy(csd->device_id, sd[j].device_id,
+				sizeof(csd->device_id));
+			memcpy(csd->vendor, sd[j].vendor,
+				sizeof(csd->vendor));
+			memcpy(csd->model, sd[j].model,
+				sizeof(csd->model));
+			memcpy(csd->revision, sd[j].revision,
+				sizeof(csd->revision));
 		} else 		/* device is same as it ever was, */
 			i++;	/* so just move along. */
 	}
@@ -577,7 +601,7 @@ adjust_cciss_scsi_table(int ctlr, int hostno,
 			csd = &ccissscsi[ctlr].dev[j];
 			if (SCSI3ADDR_EQ(sd[i].scsi3addr,
 				csd->scsi3addr)) {
-				if (sd[i].devtype == csd->devtype)
+				if (device_is_the_same(&sd[i], csd))
 					found=2;	/* found device */
 				else
 					found=1; 	/* found a bug. */
@@ -586,16 +610,14 @@ adjust_cciss_scsi_table(int ctlr, int hostno,
 		}
 		if (!found) {
 			changes++;
-			if (cciss_scsi_add_entry(ctlr, hostno, 
-
-				&sd[i].scsi3addr[0], sd[i].devtype,
+			if (cciss_scsi_add_entry(ctlr, hostno, &sd[i],
 				added, &nadded) != 0)
 				break;
 		} else if (found == 1) {
 			/* should never happen... */
 			changes++;
-			printk("cciss%d: device unexpectedly changed type\n",
-				ctlr);
+			printk(KERN_WARNING "cciss%d: device "
+				"unexpectedly changed\n", ctlr);
 			/* but if it does happen, we just ignore that device */
 		}
 	}
@@ -1012,7 +1034,8 @@ cciss_scsi_interpret_error(CommandList_struct *cp)
 
 static int
 cciss_scsi_do_inquiry(ctlr_info_t *c, unsigned char *scsi3addr, 
-		 unsigned char *buf, unsigned char bufsize)
+	unsigned char page, unsigned char *buf,
+	unsigned char bufsize)
 {
 	int rc;
 	CommandList_struct *cp;
@@ -1032,8 +1055,8 @@ cciss_scsi_do_inquiry(ctlr_info_t *c, unsigned char *scsi3addr,
 	ei = cp->err_info; 
 
 	cdb[0] = CISS_INQUIRY;
-	cdb[1] = 0;
-	cdb[2] = 0;
+	cdb[1] = (page != 0);
+	cdb[2] = page;
 	cdb[3] = 0;
 	cdb[4] = bufsize;
 	cdb[5] = 0;
@@ -1053,6 +1076,25 @@ cciss_scsi_do_inquiry(ctlr_info_t *c, unsigned char *scsi3addr,
 	return rc;	
 }
 
+/* Get the device id from inquiry page 0x83 */
+static int cciss_scsi_get_device_id(ctlr_info_t *c, unsigned char *scsi3addr,
+	unsigned char *device_id, int buflen)
+{
+	int rc;
+	unsigned char *buf;
+
+	if (buflen > 16)
+		buflen = 16;
+	buf = kzalloc(64, GFP_KERNEL);
+	if (!buf)
+		return -1;
+	rc = cciss_scsi_do_inquiry(c, scsi3addr, 0x83, buf, 64);
+	if (rc == 0)
+		memcpy(device_id, &buf[8], buflen);
+	kfree(buf);
+	return rc != 0;
+}
+
 static int
 cciss_scsi_do_report_phys_luns(ctlr_info_t *c, 
 		ReportLunData_struct *buf, int bufsize)
@@ -1142,25 +1184,21 @@ cciss_update_non_disk_devices(int cntl_num, int hostno)
 	ctlr_info_t *c;
 	__u32 num_luns=0;
 	unsigned char *ch;
-	/* unsigned char found[CCISS_MAX_SCSI_DEVS_PER_HBA]; */
-	struct cciss_scsi_dev_t currentsd[CCISS_MAX_SCSI_DEVS_PER_HBA];
+	struct cciss_scsi_dev_t *currentsd, *this_device;
 	int ncurrent=0;
 	int reportlunsize = sizeof(*ld_buff) + CISS_MAX_PHYS_LUN * 8;
 	int i;
 
 	c = (ctlr_info_t *) hba[cntl_num];	
 	ld_buff = kzalloc(reportlunsize, GFP_KERNEL);
-	if (ld_buff == NULL) {
-		printk(KERN_ERR "cciss: out of memory\n");
-		return;
-	}
 	inq_buff = kmalloc(OBDR_TAPE_INQ_SIZE, GFP_KERNEL);
-        if (inq_buff == NULL) {
-                printk(KERN_ERR "cciss: out of memory\n");
-                kfree(ld_buff);
-                return;
+	currentsd = kzalloc(sizeof(*currentsd) *
+			(CCISS_MAX_SCSI_DEVS_PER_HBA+1), GFP_KERNEL);
+	if (ld_buff == NULL || inq_buff == NULL || currentsd == NULL) {
+		printk(KERN_ERR "cciss: out of memory\n");
+		goto out;
 	}
-
+	this_device = &currentsd[CCISS_MAX_SCSI_DEVS_PER_HBA];
 	if (cciss_scsi_do_report_phys_luns(c, ld_buff, reportlunsize) == 0) {
 		ch = &ld_buff->LUNListLength[0];
 		num_luns = ((ch[0]<<24) | (ch[1]<<16) | (ch[2]<<8) | ch[3]) / 8;
@@ -1179,23 +1217,34 @@ cciss_update_non_disk_devices(int cntl_num, int hostno)
 
 
 	/* adjust our table of devices */	
-	for(i=0; i<num_luns; i++)
-	{
-		int devtype;
-
+	for (i = 0; i < num_luns; i++) {
 		/* for each physical lun, do an inquiry */
 		if (ld_buff->LUN[i][3] & 0xC0) continue;
 		memset(inq_buff, 0, OBDR_TAPE_INQ_SIZE);
 		memcpy(&scsi3addr[0], &ld_buff->LUN[i][0], 8);
 
-		if (cciss_scsi_do_inquiry(hba[cntl_num], scsi3addr, inq_buff,
-			(unsigned char) OBDR_TAPE_INQ_SIZE) != 0) {
+		if (cciss_scsi_do_inquiry(hba[cntl_num], scsi3addr, 0, inq_buff,
+			(unsigned char) OBDR_TAPE_INQ_SIZE) != 0)
 			/* Inquiry failed (msg printed already) */
-			devtype = 0; /* so we will skip this device. */
-		} else /* what kind of device is this? */
-			devtype = (inq_buff[0] & 0x1f);
-
-		switch (devtype)
+			continue; /* so we will skip this device. */
+
+		this_device->devtype = (inq_buff[0] & 0x1f);
+		this_device->bus = -1;
+		this_device->target = -1;
+		this_device->lun = -1;
+		memcpy(this_device->scsi3addr, scsi3addr, 8);
+		memcpy(this_device->vendor, &inq_buff[8],
+			sizeof(this_device->vendor));
+		memcpy(this_device->model, &inq_buff[16],
+			sizeof(this_device->model));
+		memcpy(this_device->revision, &inq_buff[32],
+			sizeof(this_device->revision));
+		memset(this_device->device_id, 0,
+			sizeof(this_device->device_id));
+		cciss_scsi_get_device_id(hba[cntl_num], scsi3addr,
+			this_device->device_id, sizeof(this_device->device_id));
+
+		switch (this_device->devtype)
 		{
 		  case 0x05: /* CD-ROM */ {
 
@@ -1220,15 +1269,10 @@ cciss_update_non_disk_devices(int cntl_num, int hostno)
 			if (ncurrent >= CCISS_MAX_SCSI_DEVS_PER_HBA) {
 				printk(KERN_INFO "cciss%d: %s ignored, "
 					"too many devices.\n", cntl_num,
-					scsi_device_type(devtype));
+					scsi_device_type(this_device->devtype));
 				break;
 			}
-			memcpy(&currentsd[ncurrent].scsi3addr[0], 
-				&scsi3addr[0], 8);
-			currentsd[ncurrent].devtype = devtype;
-			currentsd[ncurrent].bus = -1;
-			currentsd[ncurrent].target = -1;
-			currentsd[ncurrent].lun = -1;
+			currentsd[ncurrent] = *this_device;
 			ncurrent++;
 			break;
 		  default: 
@@ -1240,6 +1284,7 @@ cciss_update_non_disk_devices(int cntl_num, int hostno)
 out:
 	kfree(inq_buff);
 	kfree(ld_buff);
+	kfree(currentsd);
 	return;
 }
 
diff --git a/drivers/block/cciss_scsi.h b/drivers/block/cciss_scsi.h
index d9c2c586502..7b750245ae7 100644
--- a/drivers/block/cciss_scsi.h
+++ b/drivers/block/cciss_scsi.h
@@ -66,6 +66,10 @@ struct cciss_scsi_dev_t {
 	int devtype;
 	int bus, target, lun;		/* as presented to the OS */
 	unsigned char scsi3addr[8];	/* as presented to the HW */
+	unsigned char device_id[16];	/* from inquiry pg. 0x83 */
+	unsigned char vendor[8];	/* bytes 8-15 of inquiry data */
+	unsigned char model[16];	/* bytes 16-31 of inquiry data */
+	unsigned char revision[4];	/* bytes 32-35 of inquiry data */
 };
 
 struct cciss_scsi_hba_t {
diff --git a/drivers/block/cpqarray.c b/drivers/block/cpqarray.c
index 09c14341e6e..3d967525e9a 100644
--- a/drivers/block/cpqarray.c
+++ b/drivers/block/cpqarray.c
@@ -424,7 +424,7 @@ static int __init cpqarray_register_ctlr( int i, struct pci_dev *pdev)
 		hba[i]->pci_dev, NR_CMDS * sizeof(cmdlist_t),
 		&(hba[i]->cmd_pool_dhandle));
 	hba[i]->cmd_pool_bits = kcalloc(
-		(NR_CMDS+BITS_PER_LONG-1)/BITS_PER_LONG, sizeof(unsigned long),
+		DIV_ROUND_UP(NR_CMDS, BITS_PER_LONG), sizeof(unsigned long),
 		GFP_KERNEL);
 
 	if (!hba[i]->cmd_pool_bits || !hba[i]->cmd_pool)
diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index 395f8ea7981..cf64ddf5d83 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -423,8 +423,15 @@ static struct floppy_raw_cmd *raw_cmd, default_raw_cmd;
  * 1581's logical side 0 is on physical side 1, whereas the Sharp's logical
  * side 0 is on physical side 0 (but with the misnamed sector IDs).
  * 'stretch' should probably be renamed to something more general, like
- * 'options'.  Other parameters should be self-explanatory (see also
- * setfdprm(8)).
+ * 'options'.
+ *
+ * Bits 2 through 9 of 'stretch' tell the number of the first sector.
+ * The LSB (bit 2) is flipped. For most disks, the first sector
+ * is 1 (represented by 0x00<<2).  For some CP/M and music sampler
+ * disks (such as Ensoniq EPS 16plus) it is 0 (represented as 0x01<<2).
+ * For Amstrad CPC disks it is 0xC1 (represented as 0xC0<<2).
+ *
+ * Other parameters should be self-explanatory (see also setfdprm(8)).
  */
 /*
 	    Size
@@ -1355,20 +1362,20 @@ static void fdc_specify(void)
 	}
 
 	/* Convert step rate from microseconds to milliseconds and 4 bits */
-	srt = 16 - (DP->srt * scale_dtr / 1000 + NOMINAL_DTR - 1) / NOMINAL_DTR;
+	srt = 16 - DIV_ROUND_UP(DP->srt * scale_dtr / 1000, NOMINAL_DTR);
 	if (slow_floppy) {
 		srt = srt / 4;
 	}
 	SUPBOUND(srt, 0xf);
 	INFBOUND(srt, 0);
 
-	hlt = (DP->hlt * scale_dtr / 2 + NOMINAL_DTR - 1) / NOMINAL_DTR;
+	hlt = DIV_ROUND_UP(DP->hlt * scale_dtr / 2, NOMINAL_DTR);
 	if (hlt < 0x01)
 		hlt = 0x01;
 	else if (hlt > 0x7f)
 		hlt = hlt_max_code;
 
-	hut = (DP->hut * scale_dtr / 16 + NOMINAL_DTR - 1) / NOMINAL_DTR;
+	hut = DIV_ROUND_UP(DP->hut * scale_dtr / 16, NOMINAL_DTR);
 	if (hut < 0x1)
 		hut = 0x1;
 	else if (hut > 0xf)
@@ -2236,9 +2243,9 @@ static void setup_format_params(int track)
 			}
 		}
 	}
-	if (_floppy->stretch & FD_ZEROBASED) {
+	if (_floppy->stretch & FD_SECTBASEMASK) {
 		for (count = 0; count < F_SECT_PER_TRACK; count++)
-			here[count].sect--;
+			here[count].sect += FD_SECTBASE(_floppy) - 1;
 	}
 }
 
@@ -2385,7 +2392,7 @@ static void rw_interrupt(void)
 
 #ifdef FLOPPY_SANITY_CHECK
 	if (nr_sectors / ssize >
-	    (in_sector_offset + current_count_sectors + ssize - 1) / ssize) {
+	    DIV_ROUND_UP(in_sector_offset + current_count_sectors, ssize)) {
 		DPRINT("long rw: %x instead of %lx\n",
 		       nr_sectors, current_count_sectors);
 		printk("rs=%d s=%d\n", R_SECTOR, SECTOR);
@@ -2649,7 +2656,7 @@ static int make_raw_rw_request(void)
 	}
 	HEAD = fsector_t / _floppy->sect;
 
-	if (((_floppy->stretch & (FD_SWAPSIDES | FD_ZEROBASED)) ||
+	if (((_floppy->stretch & (FD_SWAPSIDES | FD_SECTBASEMASK)) ||
 	     TESTF(FD_NEED_TWADDLE)) && fsector_t < _floppy->sect)
 		max_sector = _floppy->sect;
 
@@ -2679,7 +2686,7 @@ static int make_raw_rw_request(void)
 	CODE2SIZE;
 	SECT_PER_TRACK = _floppy->sect << 2 >> SIZECODE;
 	SECTOR = ((fsector_t % _floppy->sect) << 2 >> SIZECODE) +
-	    ((_floppy->stretch & FD_ZEROBASED) ? 0 : 1);
+	    FD_SECTBASE(_floppy);
 
 	/* tracksize describes the size which can be filled up with sectors
 	 * of size ssize.
@@ -3311,7 +3318,7 @@ static inline int set_geometry(unsigned int cmd, struct floppy_struct *g,
 	    g->head <= 0 ||
 	    g->track <= 0 || g->track > UDP->tracks >> STRETCH(g) ||
 	    /* check if reserved bits are set */
-	    (g->stretch & ~(FD_STRETCH | FD_SWAPSIDES | FD_ZEROBASED)) != 0)
+	    (g->stretch & ~(FD_STRETCH | FD_SWAPSIDES | FD_SECTBASEMASK)) != 0)
 		return -EINVAL;
 	if (type) {
 		if (!capable(CAP_SYS_ADMIN))
@@ -3356,7 +3363,7 @@ static inline int set_geometry(unsigned int cmd, struct floppy_struct *g,
 		if (DRS->maxblock > user_params[drive].sect ||
 		    DRS->maxtrack ||
 		    ((user_params[drive].sect ^ oldStretch) &
-		     (FD_SWAPSIDES | FD_ZEROBASED)))
+		     (FD_SWAPSIDES | FD_SECTBASEMASK)))
 			invalidate_drive(bdev);
 		else
 			process_fd_request();
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 1778e4a2c67..7b3351260d5 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -403,7 +403,7 @@ static int nbd_do_it(struct nbd_device *lo)
 	BUG_ON(lo->magic != LO_MAGIC);
 
 	lo->pid = current->pid;
-	ret = sysfs_create_file(&lo->disk->dev.kobj, &pid_attr.attr);
+	ret = sysfs_create_file(&disk_to_dev(lo->disk)->kobj, &pid_attr.attr);
 	if (ret) {
 		printk(KERN_ERR "nbd: sysfs_create_file failed!");
 		return ret;
@@ -412,7 +412,7 @@ static int nbd_do_it(struct nbd_device *lo)
 	while ((req = nbd_read_stat(lo)) != NULL)
 		nbd_end_request(req);
 
-	sysfs_remove_file(&lo->disk->dev.kobj, &pid_attr.attr);
+	sysfs_remove_file(&disk_to_dev(lo->disk)->kobj, &pid_attr.attr);
 	return 0;
 }
 
diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index 29b7a648cc6..0e077150568 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -2544,7 +2544,7 @@ static int pkt_make_request(struct request_queue *q, struct bio *bio)
 		if (last_zone != zone) {
 			BUG_ON(last_zone != zone + pd->settings.size);
 			first_sectors = last_zone - bio->bi_sector;
-			bp = bio_split(bio, bio_split_pool, first_sectors);
+			bp = bio_split(bio, first_sectors);
 			BUG_ON(!bp);
 			pkt_make_request(q, &bp->bio1);
 			pkt_make_request(q, &bp->bio2);
@@ -2911,7 +2911,7 @@ static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev)
 	if (!disk->queue)
 		goto out_mem2;
 
-	pd->pkt_dev = MKDEV(disk->major, disk->first_minor);
+	pd->pkt_dev = MKDEV(pktdev_major, idx);
 	ret = pkt_new_dev(pd, dev);
 	if (ret)
 		goto out_new_dev;
diff --git a/drivers/block/ps3disk.c b/drivers/block/ps3disk.c
index d797e209951..936466f62af 100644
--- a/drivers/block/ps3disk.c
+++ b/drivers/block/ps3disk.c
@@ -199,7 +199,8 @@ static void ps3disk_do_request(struct ps3_storage_device *dev,
 		if (blk_fs_request(req)) {
 			if (ps3disk_submit_request_sg(dev, req))
 				break;
-		} else if (req->cmd_type == REQ_TYPE_FLUSH) {
+		} else if (req->cmd_type == REQ_TYPE_LINUX_BLOCK &&
+			   req->cmd[0] == REQ_LB_OP_FLUSH) {
 			if (ps3disk_submit_flush_request(dev, req))
 				break;
 		} else {
@@ -257,7 +258,8 @@ static irqreturn_t ps3disk_interrupt(int irq, void *data)
 		return IRQ_HANDLED;
 	}
 
-	if (req->cmd_type == REQ_TYPE_FLUSH) {
+	if (req->cmd_type == REQ_TYPE_LINUX_BLOCK &&
+	    req->cmd[0] == REQ_LB_OP_FLUSH) {
 		read = 0;
 		num_sectors = req->hard_cur_sectors;
 		op = "flush";
@@ -405,7 +407,8 @@ static void ps3disk_prepare_flush(struct request_queue *q, struct request *req)
 
 	dev_dbg(&dev->sbd.core, "%s:%u\n", __func__, __LINE__);
 
-	req->cmd_type = REQ_TYPE_FLUSH;
+	req->cmd_type = REQ_TYPE_LINUX_BLOCK;
+	req->cmd[0] = REQ_LB_OP_FLUSH;
 }
 
 static unsigned long ps3disk_mask;
@@ -538,7 +541,7 @@ static int ps3disk_remove(struct ps3_system_bus_device *_dev)
 	struct ps3disk_private *priv = dev->sbd.core.driver_data;
 
 	mutex_lock(&ps3disk_mask_mutex);
-	__clear_bit(priv->gendisk->first_minor / PS3DISK_MINORS,
+	__clear_bit(MINOR(disk_devt(priv->gendisk)) / PS3DISK_MINORS,
 		    &ps3disk_mask);
 	mutex_unlock(&ps3disk_mask_mutex);
 	del_gendisk(priv->gendisk);
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 42251095134..6ec5fc05278 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -47,20 +47,20 @@ static void blk_done(struct virtqueue *vq)
 
 	spin_lock_irqsave(&vblk->lock, flags);
 	while ((vbr = vblk->vq->vq_ops->get_buf(vblk->vq, &len)) != NULL) {
-		int uptodate;
+		int error;
 		switch (vbr->status) {
 		case VIRTIO_BLK_S_OK:
-			uptodate = 1;
+			error = 0;
 			break;
 		case VIRTIO_BLK_S_UNSUPP:
-			uptodate = -ENOTTY;
+			error = -ENOTTY;
 			break;
 		default:
-			uptodate = 0;
+			error = -EIO;
 			break;
 		}
 
-		end_dequeued_request(vbr->req, uptodate);
+		__blk_end_request(vbr->req, error, blk_rq_bytes(vbr->req));
 		list_del(&vbr->list);
 		mempool_free(vbr, vblk->pool);
 	}
@@ -84,11 +84,11 @@ static bool do_req(struct request_queue *q, struct virtio_blk *vblk,
 	if (blk_fs_request(vbr->req)) {
 		vbr->out_hdr.type = 0;
 		vbr->out_hdr.sector = vbr->req->sector;
-		vbr->out_hdr.ioprio = vbr->req->ioprio;
+		vbr->out_hdr.ioprio = req_get_ioprio(vbr->req);
 	} else if (blk_pc_request(vbr->req)) {
 		vbr->out_hdr.type = VIRTIO_BLK_T_SCSI_CMD;
 		vbr->out_hdr.sector = 0;
-		vbr->out_hdr.ioprio = vbr->req->ioprio;
+		vbr->out_hdr.ioprio = req_get_ioprio(vbr->req);
 	} else {
 		/* We don't put anything else in the queue. */
 		BUG();
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 3ca643cafcc..bff602ccccf 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -105,15 +105,17 @@ static DEFINE_SPINLOCK(blkif_io_lock);
 #define GRANT_INVALID_REF	0
 
 #define PARTS_PER_DISK		16
+#define PARTS_PER_EXT_DISK      256
 
 #define BLKIF_MAJOR(dev) ((dev)>>8)
 #define BLKIF_MINOR(dev) ((dev) & 0xff)
 
-#define DEV_NAME	"xvd"	/* name in /dev */
+#define EXT_SHIFT 28
+#define EXTENDED (1<<EXT_SHIFT)
+#define VDEV_IS_EXTENDED(dev) ((dev)&(EXTENDED))
+#define BLKIF_MINOR_EXT(dev) ((dev)&(~EXTENDED))
 
-/* Information about our VBDs. */
-#define MAX_VBDS 64
-static LIST_HEAD(vbds_list);
+#define DEV_NAME	"xvd"	/* name in /dev */
 
 static int get_id_from_freelist(struct blkfront_info *info)
 {
@@ -386,31 +388,60 @@ static int xlvbd_barrier(struct blkfront_info *info)
 }
 
 
-static int xlvbd_alloc_gendisk(int minor, blkif_sector_t capacity,
-			       int vdevice, u16 vdisk_info, u16 sector_size,
-			       struct blkfront_info *info)
+static int xlvbd_alloc_gendisk(blkif_sector_t capacity,
+			       struct blkfront_info *info,
+			       u16 vdisk_info, u16 sector_size)
 {
 	struct gendisk *gd;
 	int nr_minors = 1;
 	int err = -ENODEV;
+	unsigned int offset;
+	int minor;
+	int nr_parts;
 
 	BUG_ON(info->gd != NULL);
 	BUG_ON(info->rq != NULL);
 
-	if ((minor % PARTS_PER_DISK) == 0)
-		nr_minors = PARTS_PER_DISK;
+	if ((info->vdevice>>EXT_SHIFT) > 1) {
+		/* this is above the extended range; something is wrong */
+		printk(KERN_WARNING "blkfront: vdevice 0x%x is above the extended range; ignoring\n", info->vdevice);
+		return -ENODEV;
+	}
+
+	if (!VDEV_IS_EXTENDED(info->vdevice)) {
+		minor = BLKIF_MINOR(info->vdevice);
+		nr_parts = PARTS_PER_DISK;
+	} else {
+		minor = BLKIF_MINOR_EXT(info->vdevice);
+		nr_parts = PARTS_PER_EXT_DISK;
+	}
+
+	if ((minor % nr_parts) == 0)
+		nr_minors = nr_parts;
 
 	gd = alloc_disk(nr_minors);
 	if (gd == NULL)
 		goto out;
 
-	if (nr_minors > 1)
-		sprintf(gd->disk_name, "%s%c", DEV_NAME,
-			'a' + minor / PARTS_PER_DISK);
-	else
-		sprintf(gd->disk_name, "%s%c%d", DEV_NAME,
-			'a' + minor / PARTS_PER_DISK,
-			minor % PARTS_PER_DISK);
+	offset = minor / nr_parts;
+
+	if (nr_minors > 1) {
+		if (offset < 26)
+			sprintf(gd->disk_name, "%s%c", DEV_NAME, 'a' + offset);
+		else
+			sprintf(gd->disk_name, "%s%c%c", DEV_NAME,
+				'a' + ((offset / 26)-1), 'a' + (offset % 26));
+	} else {
+		if (offset < 26)
+			sprintf(gd->disk_name, "%s%c%d", DEV_NAME,
+				'a' + offset,
+				minor & (nr_parts - 1));
+		else
+			sprintf(gd->disk_name, "%s%c%c%d", DEV_NAME,
+				'a' + ((offset / 26) - 1),
+				'a' + (offset % 26),
+				minor & (nr_parts - 1));
+	}
 
 	gd->major = XENVBD_MAJOR;
 	gd->first_minor = minor;
@@ -699,8 +730,13 @@ static int blkfront_probe(struct xenbus_device *dev,
 	err = xenbus_scanf(XBT_NIL, dev->nodename,
 			   "virtual-device", "%i", &vdevice);
 	if (err != 1) {
-		xenbus_dev_fatal(dev, err, "reading virtual-device");
-		return err;
+		/* go looking in the extended area instead */
+		err = xenbus_scanf(XBT_NIL, dev->nodename, "virtual-device-ext",
+				   "%i", &vdevice);
+		if (err != 1) {
+			xenbus_dev_fatal(dev, err, "reading virtual-device");
+			return err;
+		}
 	}
 
 	info = kzalloc(sizeof(*info), GFP_KERNEL);
@@ -861,9 +897,7 @@ static void blkfront_connect(struct blkfront_info *info)
 	if (err)
 		info->feature_barrier = 0;
 
-	err = xlvbd_alloc_gendisk(BLKIF_MINOR(info->vdevice),
-				  sectors, info->vdevice,
-				  binfo, sector_size, info);
+	err = xlvbd_alloc_gendisk(sectors, info, binfo, sector_size);
 	if (err) {
 		xenbus_dev_fatal(info->xbdev, err, "xlvbd_add at %s",
 				 info->xbdev->otherend);
diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c
index 74031de517e..d47f2f80acc 100644
--- a/drivers/cdrom/cdrom.c
+++ b/drivers/cdrom/cdrom.c
@@ -2097,7 +2097,7 @@ static int cdrom_read_cdda_bpc(struct cdrom_device_info *cdi, __u8 __user *ubuf,
 
 		len = nr * CD_FRAMESIZE_RAW;
 
-		ret = blk_rq_map_user(q, rq, ubuf, len);
+		ret = blk_rq_map_user(q, rq, NULL, ubuf, len, GFP_KERNEL);
 		if (ret)
 			break;
 
diff --git a/drivers/cdrom/gdrom.c b/drivers/cdrom/gdrom.c
index 1231d95aa69..d6ba77a2dd7 100644
--- a/drivers/cdrom/gdrom.c
+++ b/drivers/cdrom/gdrom.c
@@ -624,14 +624,14 @@ static void gdrom_readdisk_dma(struct work_struct *work)
 		ctrl_outb(1, GDROM_DMA_STATUS_REG);
 		wait_event_interruptible_timeout(request_queue,
 			gd.transfer == 0, GDROM_DEFAULT_TIMEOUT);
-		err = gd.transfer;
+		err = gd.transfer ? -EIO : 0;
 		gd.transfer = 0;
 		gd.pending = 0;
 		/* now seek to take the request spinlock
 		* before handling ending the request */
 		spin_lock(&gdrom_lock);
 		list_del_init(&req->queuelist);
-		end_dequeued_request(req, 1 - err);
+		__blk_end_request(req, err, blk_rq_bytes(req));
 	}
 	spin_unlock(&gdrom_lock);
 	kfree(read_command);
diff --git a/drivers/char/random.c b/drivers/char/random.c
index 7ce1ac4baa6..6af435b8986 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -661,10 +661,10 @@ void add_disk_randomness(struct gendisk *disk)
 	if (!disk || !disk->random)
 		return;
 	/* first major is 1, so we get >= 0x200 here */
-	DEBUG_ENT("disk event %d:%d\n", disk->major, disk->first_minor);
+	DEBUG_ENT("disk event %d:%d\n",
+		  MAJOR(disk_devt(disk)), MINOR(disk_devt(disk)));
 
-	add_timer_randomness(disk->random,
-			     0x100 + MKDEV(disk->major, disk->first_minor));
+	add_timer_randomness(disk->random, 0x100 + disk_devt(disk));
 }
 #endif
 
diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c
index f16bb466723..03c2cb6a58b 100644
--- a/drivers/ide/ide-cd.c
+++ b/drivers/ide/ide-cd.c
@@ -1113,7 +1113,7 @@ static ide_startstop_t cdrom_start_rw(ide_drive_t *drive, struct request *rq)
 
 	if (write) {
 		/* disk has become write protected */
-		if (cd->disk->policy) {
+		if (get_disk_ro(cd->disk)) {
 			cdrom_end_request(drive, 0);
 			return ide_stopped;
 		}
diff --git a/drivers/ide/ide-disk.c b/drivers/ide/ide-disk.c
index 07ef88bd109..33ea8c04871 100644
--- a/drivers/ide/ide-disk.c
+++ b/drivers/ide/ide-disk.c
@@ -41,6 +41,12 @@
 #include <asm/io.h>
 #include <asm/div64.h>
 
+#if !defined(CONFIG_DEBUG_BLOCK_EXT_DEVT)
+#define IDE_DISK_MINORS		(1 << PARTN_BITS)
+#else
+#define IDE_DISK_MINORS		0
+#endif
+
 struct ide_disk_obj {
 	ide_drive_t	*drive;
 	ide_driver_t	*driver;
@@ -1151,8 +1157,7 @@ static int ide_disk_probe(ide_drive_t *drive)
 	if (!idkp)
 		goto failed;
 
-	g = alloc_disk_node(1 << PARTN_BITS,
-			hwif_to_node(drive->hwif));
+	g = alloc_disk_node(IDE_DISK_MINORS, hwif_to_node(drive->hwif));
 	if (!g)
 		goto out_free_idkp;
 
@@ -1178,9 +1183,11 @@ static int ide_disk_probe(ide_drive_t *drive)
 	} else
 		drive->attach = 1;
 
-	g->minors = 1 << PARTN_BITS;
+	g->minors = IDE_DISK_MINORS;
 	g->driverfs_dev = &drive->gendev;
-	g->flags = drive->removable ? GENHD_FL_REMOVABLE : 0;
+	g->flags |= GENHD_FL_EXT_DEVT;
+	if (drive->removable)
+		g->flags |= GENHD_FL_REMOVABLE;
 	set_capacity(g, idedisk_capacity(drive));
 	g->fops = &idedisk_ops;
 	add_disk(g);
diff --git a/drivers/ide/ide-probe.c b/drivers/ide/ide-probe.c
index a51a30e9eab..70aa86c8807 100644
--- a/drivers/ide/ide-probe.c
+++ b/drivers/ide/ide-probe.c
@@ -1188,7 +1188,7 @@ static struct kobject *exact_match(dev_t dev, int *part, void *data)
 {
 	struct gendisk *p = data;
 	*part &= (1 << PARTN_BITS) - 1;
-	return &p->dev.kobj;
+	return &disk_to_dev(p)->kobj;
 }
 
 static int exact_lock(dev_t dev, void *data)
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
index b262c0042de..5b919159f08 100644
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -426,7 +426,7 @@ static int list_devices(struct dm_ioctl *param, size_t param_size)
 				old_nl->next = (uint32_t) ((void *) nl -
 							   (void *) old_nl);
 			disk = dm_disk(hc->md);
-			nl->dev = huge_encode_dev(MKDEV(disk->major, disk->first_minor));
+			nl->dev = huge_encode_dev(disk_devt(disk));
 			nl->next = 0;
 			strcpy(nl->name, hc->name);
 
@@ -539,7 +539,7 @@ static int __dev_status(struct mapped_device *md, struct dm_ioctl *param)
 	if (dm_suspended(md))
 		param->flags |= DM_SUSPEND_FLAG;
 
-	param->dev = huge_encode_dev(MKDEV(disk->major, disk->first_minor));
+	param->dev = huge_encode_dev(disk_devt(disk));
 
 	/*
 	 * Yes, this will be out of date by the time it gets back
@@ -548,7 +548,7 @@ static int __dev_status(struct mapped_device *md, struct dm_ioctl *param)
 	 */
 	param->open_count = dm_open_count(md);
 
-	if (disk->policy)
+	if (get_disk_ro(disk))
 		param->flags |= DM_READONLY_FLAG;
 
 	param->event_nr = dm_get_event_nr(md);
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index c2fcf28b4c7..3d3848132c6 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -33,6 +33,7 @@ struct pgpath {
 	unsigned fail_count;		/* Cumulative failure count */
 
 	struct dm_path path;
+	struct work_struct deactivate_path;
 };
 
 #define path_to_pgpath(__pgp) container_of((__pgp), struct pgpath, path)
@@ -112,6 +113,7 @@ static struct workqueue_struct *kmultipathd, *kmpath_handlerd;
 static void process_queued_ios(struct work_struct *work);
 static void trigger_event(struct work_struct *work);
 static void activate_path(struct work_struct *work);
+static void deactivate_path(struct work_struct *work);
 
 
 /*-----------------------------------------------
@@ -122,8 +124,10 @@ static struct pgpath *alloc_pgpath(void)
 {
 	struct pgpath *pgpath = kzalloc(sizeof(*pgpath), GFP_KERNEL);
 
-	if (pgpath)
+	if (pgpath) {
 		pgpath->path.is_active = 1;
+		INIT_WORK(&pgpath->deactivate_path, deactivate_path);
+	}
 
 	return pgpath;
 }
@@ -133,6 +137,14 @@ static void free_pgpath(struct pgpath *pgpath)
 	kfree(pgpath);
 }
 
+static void deactivate_path(struct work_struct *work)
+{
+	struct pgpath *pgpath =
+		container_of(work, struct pgpath, deactivate_path);
+
+	blk_abort_queue(pgpath->path.dev->bdev->bd_disk->queue);
+}
+
 static struct priority_group *alloc_priority_group(void)
 {
 	struct priority_group *pg;
@@ -870,6 +882,7 @@ static int fail_path(struct pgpath *pgpath)
 		      pgpath->path.dev->name, m->nr_valid_paths);
 
 	queue_work(kmultipathd, &m->trigger_event);
+	queue_work(kmultipathd, &pgpath->deactivate_path);
 
 out:
 	spin_unlock_irqrestore(&m->lock, flags);
diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c
index 4de90ab3968..b745d8ac625 100644
--- a/drivers/md/dm-stripe.c
+++ b/drivers/md/dm-stripe.c
@@ -284,8 +284,8 @@ static int stripe_end_io(struct dm_target *ti, struct bio *bio,
 
 	memset(major_minor, 0, sizeof(major_minor));
 	sprintf(major_minor, "%d:%d",
-		bio->bi_bdev->bd_disk->major,
-		bio->bi_bdev->bd_disk->first_minor);
+		MAJOR(disk_devt(bio->bi_bdev->bd_disk)),
+		MINOR(disk_devt(bio->bi_bdev->bd_disk)));
 
 	/*
 	 * Test to see which stripe drive triggered the event
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index ace998ce59f..327de03a5bd 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -377,13 +377,14 @@ static void free_tio(struct mapped_device *md, struct dm_target_io *tio)
 static void start_io_acct(struct dm_io *io)
 {
 	struct mapped_device *md = io->md;
+	int cpu;
 
 	io->start_time = jiffies;
 
-	preempt_disable();
-	disk_round_stats(dm_disk(md));
-	preempt_enable();
-	dm_disk(md)->in_flight = atomic_inc_return(&md->pending);
+	cpu = part_stat_lock();
+	part_round_stats(cpu, &dm_disk(md)->part0);
+	part_stat_unlock();
+	dm_disk(md)->part0.in_flight = atomic_inc_return(&md->pending);
 }
 
 static int end_io_acct(struct dm_io *io)
@@ -391,15 +392,16 @@ static int end_io_acct(struct dm_io *io)
 	struct mapped_device *md = io->md;
 	struct bio *bio = io->bio;
 	unsigned long duration = jiffies - io->start_time;
-	int pending;
+	int pending, cpu;
 	int rw = bio_data_dir(bio);
 
-	preempt_disable();
-	disk_round_stats(dm_disk(md));
-	preempt_enable();
-	dm_disk(md)->in_flight = pending = atomic_dec_return(&md->pending);
+	cpu = part_stat_lock();
+	part_round_stats(cpu, &dm_disk(md)->part0);
+	part_stat_add(cpu, &dm_disk(md)->part0, ticks[rw], duration);
+	part_stat_unlock();
 
-	disk_stat_add(dm_disk(md), ticks[rw], duration);
+	dm_disk(md)->part0.in_flight = pending =
+		atomic_dec_return(&md->pending);
 
 	return !pending;
 }
@@ -885,6 +887,7 @@ static int dm_request(struct request_queue *q, struct bio *bio)
 	int r = -EIO;
 	int rw = bio_data_dir(bio);
 	struct mapped_device *md = q->queuedata;
+	int cpu;
 
 	/*
 	 * There is no use in forwarding any barrier request since we can't
@@ -897,8 +900,10 @@ static int dm_request(struct request_queue *q, struct bio *bio)
 
 	down_read(&md->io_lock);
 
-	disk_stat_inc(dm_disk(md), ios[rw]);
-	disk_stat_add(dm_disk(md), sectors[rw], bio_sectors(bio));
+	cpu = part_stat_lock();
+	part_stat_inc(cpu, &dm_disk(md)->part0, ios[rw]);
+	part_stat_add(cpu, &dm_disk(md)->part0, sectors[rw], bio_sectors(bio));
+	part_stat_unlock();
 
 	/*
 	 * If we're suspended we have to queue
@@ -1146,7 +1151,7 @@ static void unlock_fs(struct mapped_device *md);
 
 static void free_dev(struct mapped_device *md)
 {
-	int minor = md->disk->first_minor;
+	int minor = MINOR(disk_devt(md->disk));
 
 	if (md->suspended_bdev) {
 		unlock_fs(md);
@@ -1182,7 +1187,7 @@ static void event_callback(void *context)
 	list_splice_init(&md->uevent_list, &uevents);
 	spin_unlock_irqrestore(&md->uevent_lock, flags);
 
-	dm_send_uevents(&uevents, &md->disk->dev.kobj);
+	dm_send_uevents(&uevents, &disk_to_dev(md->disk)->kobj);
 
 	atomic_inc(&md->event_nr);
 	wake_up(&md->eventq);
@@ -1267,7 +1272,7 @@ static struct mapped_device *dm_find_md(dev_t dev)
 
 	md = idr_find(&_minor_idr, minor);
 	if (md && (md == MINOR_ALLOCED ||
-		   (dm_disk(md)->first_minor != minor) ||
+		   (MINOR(disk_devt(dm_disk(md))) != minor) ||
 		   test_bit(DMF_FREEING, &md->flags))) {
 		md = NULL;
 		goto out;
@@ -1318,7 +1323,8 @@ void dm_put(struct mapped_device *md)
 
 	if (atomic_dec_and_lock(&md->holders, &_minor_lock)) {
 		map = dm_get_table(md);
-		idr_replace(&_minor_idr, MINOR_ALLOCED, dm_disk(md)->first_minor);
+		idr_replace(&_minor_idr, MINOR_ALLOCED,
+			    MINOR(disk_devt(dm_disk(md))));
 		set_bit(DMF_FREEING, &md->flags);
 		spin_unlock(&_minor_lock);
 		if (!dm_suspended(md)) {
@@ -1638,7 +1644,7 @@ out:
  *---------------------------------------------------------------*/
 void dm_kobject_uevent(struct mapped_device *md)
 {
-	kobject_uevent(&md->disk->dev.kobj, KOBJ_CHANGE);
+	kobject_uevent(&disk_to_dev(md->disk)->kobj, KOBJ_CHANGE);
 }
 
 uint32_t dm_next_uevent_seq(struct mapped_device *md)
diff --git a/drivers/md/linear.c b/drivers/md/linear.c
index b1eebf88c20..b9cbee688fa 100644
--- a/drivers/md/linear.c
+++ b/drivers/md/linear.c
@@ -318,14 +318,18 @@ static int linear_make_request (struct request_queue *q, struct bio *bio)
 	mddev_t *mddev = q->queuedata;
 	dev_info_t *tmp_dev;
 	sector_t block;
+	int cpu;
 
 	if (unlikely(bio_barrier(bio))) {
 		bio_endio(bio, -EOPNOTSUPP);
 		return 0;
 	}
 
-	disk_stat_inc(mddev->gendisk, ios[rw]);
-	disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bio));
+	cpu = part_stat_lock();
+	part_stat_inc(cpu, &mddev->gendisk->part0, ios[rw]);
+	part_stat_add(cpu, &mddev->gendisk->part0, sectors[rw],
+		      bio_sectors(bio));
+	part_stat_unlock();
 
 	tmp_dev = which_dev(mddev, bio->bi_sector);
 	block = bio->bi_sector >> 1;
@@ -349,7 +353,7 @@ static int linear_make_request (struct request_queue *q, struct bio *bio)
 		 * split it.
 		 */
 		struct bio_pair *bp;
-		bp = bio_split(bio, bio_split_pool,
+		bp = bio_split(bio,
 			       ((tmp_dev->offset + tmp_dev->size)<<1) - bio->bi_sector);
 		if (linear_make_request(q, &bp->bio1))
 			generic_make_request(&bp->bio1);
diff --git a/drivers/md/md.c b/drivers/md/md.c
index deeac4b4417..0a3a4bdcd4a 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -1464,10 +1464,7 @@ static int bind_rdev_to_array(mdk_rdev_t * rdev, mddev_t * mddev)
 	if ((err = kobject_add(&rdev->kobj, &mddev->kobj, "dev-%s", b)))
 		goto fail;
 
-	if (rdev->bdev->bd_part)
-		ko = &rdev->bdev->bd_part->dev.kobj;
-	else
-		ko = &rdev->bdev->bd_disk->dev.kobj;
+	ko = &part_to_dev(rdev->bdev->bd_part)->kobj;
 	if ((err = sysfs_create_link(&rdev->kobj, ko, "block"))) {
 		kobject_del(&rdev->kobj);
 		goto fail;
@@ -3470,8 +3467,8 @@ static struct kobject *md_probe(dev_t dev, int *part, void *data)
 	disk->queue = mddev->queue;
 	add_disk(disk);
 	mddev->gendisk = disk;
-	error = kobject_init_and_add(&mddev->kobj, &md_ktype, &disk->dev.kobj,
-				     "%s", "md");
+	error = kobject_init_and_add(&mddev->kobj, &md_ktype,
+				     &disk_to_dev(disk)->kobj, "%s", "md");
 	mutex_unlock(&disks_mutex);
 	if (error)
 		printk(KERN_WARNING "md: cannot register %s/md - name in use\n",
@@ -3761,7 +3758,7 @@ static int do_md_run(mddev_t * mddev)
 	sysfs_notify(&mddev->kobj, NULL, "array_state");
 	sysfs_notify(&mddev->kobj, NULL, "sync_action");
 	sysfs_notify(&mddev->kobj, NULL, "degraded");
-	kobject_uevent(&mddev->gendisk->dev.kobj, KOBJ_CHANGE);
+	kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
 	return 0;
 }
 
@@ -5549,8 +5546,8 @@ static int is_mddev_idle(mddev_t *mddev)
 	rcu_read_lock();
 	rdev_for_each_rcu(rdev, mddev) {
 		struct gendisk *disk = rdev->bdev->bd_contains->bd_disk;
-		curr_events = disk_stat_read(disk, sectors[0]) + 
-				disk_stat_read(disk, sectors[1]) - 
+		curr_events = part_stat_read(&disk->part0, sectors[0]) +
+				part_stat_read(&disk->part0, sectors[1]) -
 				atomic_read(&disk->sync_io);
 		/* sync IO will cause sync_io to increase before the disk_stats
 		 * as sync_io is counted when a request starts, and
diff --git a/drivers/md/multipath.c b/drivers/md/multipath.c
index c4779ccba1c..8bb8794129b 100644
--- a/drivers/md/multipath.c
+++ b/drivers/md/multipath.c
@@ -147,6 +147,7 @@ static int multipath_make_request (struct request_queue *q, struct bio * bio)
 	struct multipath_bh * mp_bh;
 	struct multipath_info *multipath;
 	const int rw = bio_data_dir(bio);
+	int cpu;
 
 	if (unlikely(bio_barrier(bio))) {
 		bio_endio(bio, -EOPNOTSUPP);
@@ -158,8 +159,11 @@ static int multipath_make_request (struct request_queue *q, struct bio * bio)
 	mp_bh->master_bio = bio;
 	mp_bh->mddev = mddev;
 
-	disk_stat_inc(mddev->gendisk, ios[rw]);
-	disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bio));
+	cpu = part_stat_lock();
+	part_stat_inc(cpu, &mddev->gendisk->part0, ios[rw]);
+	part_stat_add(cpu, &mddev->gendisk->part0, sectors[rw],
+		      bio_sectors(bio));
+	part_stat_unlock();
 
 	mp_bh->path = multipath_map(conf);
 	if (mp_bh->path < 0) {
diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index 18361063566..53508a8a981 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -399,14 +399,18 @@ static int raid0_make_request (struct request_queue *q, struct bio *bio)
 	sector_t chunk;
 	sector_t block, rsect;
 	const int rw = bio_data_dir(bio);
+	int cpu;
 
 	if (unlikely(bio_barrier(bio))) {
 		bio_endio(bio, -EOPNOTSUPP);
 		return 0;
 	}
 
-	disk_stat_inc(mddev->gendisk, ios[rw]);
-	disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bio));
+	cpu = part_stat_lock();
+	part_stat_inc(cpu, &mddev->gendisk->part0, ios[rw]);
+	part_stat_add(cpu, &mddev->gendisk->part0, sectors[rw],
+		      bio_sectors(bio));
+	part_stat_unlock();
 
 	chunk_size = mddev->chunk_size >> 10;
 	chunk_sects = mddev->chunk_size >> 9;
@@ -423,7 +427,7 @@ static int raid0_make_request (struct request_queue *q, struct bio *bio)
 		/* This is a one page bio that upper layers
 		 * refuse to split for us, so we need to split it.
 		 */
-		bp = bio_split(bio, bio_split_pool, chunk_sects - (bio->bi_sector & (chunk_sects - 1)) );
+		bp = bio_split(bio, chunk_sects - (bio->bi_sector & (chunk_sects - 1)));
 		if (raid0_make_request(q, &bp->bio1))
 			generic_make_request(&bp->bio1);
 		if (raid0_make_request(q, &bp->bio2))
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 03a5ab705c2..b9764429d85 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -779,7 +779,7 @@ static int make_request(struct request_queue *q, struct bio * bio)
 	struct page **behind_pages = NULL;
 	const int rw = bio_data_dir(bio);
 	const int do_sync = bio_sync(bio);
-	int do_barriers;
+	int cpu, do_barriers;
 	mdk_rdev_t *blocked_rdev;
 
 	/*
@@ -804,8 +804,11 @@ static int make_request(struct request_queue *q, struct bio * bio)
 
 	bitmap = mddev->bitmap;
 
-	disk_stat_inc(mddev->gendisk, ios[rw]);
-	disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bio));
+	cpu = part_stat_lock();
+	part_stat_inc(cpu, &mddev->gendisk->part0, ios[rw]);
+	part_stat_add(cpu, &mddev->gendisk->part0, sectors[rw],
+		      bio_sectors(bio));
+	part_stat_unlock();
 
 	/*
 	 * make_request() can abort the operation when READA is being
@@ -1302,9 +1305,6 @@ static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio)
 					sbio->bi_size = r1_bio->sectors << 9;
 					sbio->bi_idx = 0;
 					sbio->bi_phys_segments = 0;
-					sbio->bi_hw_segments = 0;
-					sbio->bi_hw_front_size = 0;
-					sbio->bi_hw_back_size = 0;
 					sbio->bi_flags &= ~(BIO_POOL_MASK - 1);
 					sbio->bi_flags |= 1 << BIO_UPTODATE;
 					sbio->bi_next = NULL;
@@ -1790,7 +1790,6 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, i
 		bio->bi_vcnt = 0;
 		bio->bi_idx = 0;
 		bio->bi_phys_segments = 0;
-		bio->bi_hw_segments = 0;
 		bio->bi_size = 0;
 		bio->bi_end_io = NULL;
 		bio->bi_private = NULL;
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index e34cd0e6247..8bdc9bfc288 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -789,6 +789,7 @@ static int make_request(struct request_queue *q, struct bio * bio)
 	mirror_info_t *mirror;
 	r10bio_t *r10_bio;
 	struct bio *read_bio;
+	int cpu;
 	int i;
 	int chunk_sects = conf->chunk_mask + 1;
 	const int rw = bio_data_dir(bio);
@@ -816,7 +817,7 @@ static int make_request(struct request_queue *q, struct bio * bio)
 		/* This is a one page bio that upper layers
 		 * refuse to split for us, so we need to split it.
 		 */
-		bp = bio_split(bio, bio_split_pool,
+		bp = bio_split(bio,
 			       chunk_sects - (bio->bi_sector & (chunk_sects - 1)) );
 		if (make_request(q, &bp->bio1))
 			generic_make_request(&bp->bio1);
@@ -843,8 +844,11 @@ static int make_request(struct request_queue *q, struct bio * bio)
 	 */
 	wait_barrier(conf);
 
-	disk_stat_inc(mddev->gendisk, ios[rw]);
-	disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bio));
+	cpu = part_stat_lock();
+	part_stat_inc(cpu, &mddev->gendisk->part0, ios[rw]);
+	part_stat_add(cpu, &mddev->gendisk->part0, sectors[rw],
+		      bio_sectors(bio));
+	part_stat_unlock();
 
 	r10_bio = mempool_alloc(conf->r10bio_pool, GFP_NOIO);
 
@@ -1345,9 +1349,6 @@ static void sync_request_write(mddev_t *mddev, r10bio_t *r10_bio)
 		tbio->bi_size = r10_bio->sectors << 9;
 		tbio->bi_idx = 0;
 		tbio->bi_phys_segments = 0;
-		tbio->bi_hw_segments = 0;
-		tbio->bi_hw_front_size = 0;
-		tbio->bi_hw_back_size = 0;
 		tbio->bi_flags &= ~(BIO_POOL_MASK - 1);
 		tbio->bi_flags |= 1 << BIO_UPTODATE;
 		tbio->bi_next = NULL;
@@ -1947,7 +1948,6 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, i
 		bio->bi_vcnt = 0;
 		bio->bi_idx = 0;
 		bio->bi_phys_segments = 0;
-		bio->bi_hw_segments = 0;
 		bio->bi_size = 0;
 	}
 
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 224de022e7c..ae16794bef2 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -101,6 +101,40 @@
 const char raid6_empty_zero_page[PAGE_SIZE] __attribute__((aligned(256)));
 #endif
 
+/*
+ * We maintain a biased count of active stripes in the bottom 16 bits of
+ * bi_phys_segments, and a count of processed stripes in the upper 16 bits
+ */
+static inline int raid5_bi_phys_segments(struct bio *bio)
+{
+	return bio->bi_phys_segments & 0xffff;
+}
+
+static inline int raid5_bi_hw_segments(struct bio *bio)
+{
+	return (bio->bi_phys_segments >> 16) & 0xffff;
+}
+
+static inline int raid5_dec_bi_phys_segments(struct bio *bio)
+{
+	--bio->bi_phys_segments;
+	return raid5_bi_phys_segments(bio);
+}
+
+static inline int raid5_dec_bi_hw_segments(struct bio *bio)
+{
+	unsigned short val = raid5_bi_hw_segments(bio);
+
+	--val;
+	bio->bi_phys_segments = (val << 16) | raid5_bi_phys_segments(bio);
+	return val;
+}
+
+static inline void raid5_set_bi_hw_segments(struct bio *bio, unsigned int cnt)
+{
+	bio->bi_phys_segments = raid5_bi_phys_segments(bio) || (cnt << 16);
+}
+
 static inline int raid6_next_disk(int disk, int raid_disks)
 {
 	disk++;
@@ -507,7 +541,7 @@ static void ops_complete_biofill(void *stripe_head_ref)
 			while (rbi && rbi->bi_sector <
 				dev->sector + STRIPE_SECTORS) {
 				rbi2 = r5_next_bio(rbi, dev->sector);
-				if (--rbi->bi_phys_segments == 0) {
+				if (!raid5_dec_bi_phys_segments(rbi)) {
 					rbi->bi_next = return_bi;
 					return_bi = rbi;
 				}
@@ -1725,7 +1759,7 @@ static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, in
 	if (*bip)
 		bi->bi_next = *bip;
 	*bip = bi;
-	bi->bi_phys_segments ++;
+	bi->bi_phys_segments++;
 	spin_unlock_irq(&conf->device_lock);
 	spin_unlock(&sh->lock);
 
@@ -1819,7 +1853,7 @@ handle_failed_stripe(raid5_conf_t *conf, struct stripe_head *sh,
 			sh->dev[i].sector + STRIPE_SECTORS) {
 			struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector);
 			clear_bit(BIO_UPTODATE, &bi->bi_flags);
-			if (--bi->bi_phys_segments == 0) {
+			if (!raid5_dec_bi_phys_segments(bi)) {
 				md_write_end(conf->mddev);
 				bi->bi_next = *return_bi;
 				*return_bi = bi;
@@ -1834,7 +1868,7 @@ handle_failed_stripe(raid5_conf_t *conf, struct stripe_head *sh,
 		       sh->dev[i].sector + STRIPE_SECTORS) {
 			struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector);
 			clear_bit(BIO_UPTODATE, &bi->bi_flags);
-			if (--bi->bi_phys_segments == 0) {
+			if (!raid5_dec_bi_phys_segments(bi)) {
 				md_write_end(conf->mddev);
 				bi->bi_next = *return_bi;
 				*return_bi = bi;
@@ -1858,7 +1892,7 @@ handle_failed_stripe(raid5_conf_t *conf, struct stripe_head *sh,
 				struct bio *nextbi =
 					r5_next_bio(bi, sh->dev[i].sector);
 				clear_bit(BIO_UPTODATE, &bi->bi_flags);
-				if (--bi->bi_phys_segments == 0) {
+				if (!raid5_dec_bi_phys_segments(bi)) {
 					bi->bi_next = *return_bi;
 					*return_bi = bi;
 				}
@@ -2033,7 +2067,7 @@ static void handle_stripe_clean_event(raid5_conf_t *conf,
 				while (wbi && wbi->bi_sector <
 					dev->sector + STRIPE_SECTORS) {
 					wbi2 = r5_next_bio(wbi, dev->sector);
-					if (--wbi->bi_phys_segments == 0) {
+					if (!raid5_dec_bi_phys_segments(wbi)) {
 						md_write_end(conf->mddev);
 						wbi->bi_next = *return_bi;
 						*return_bi = wbi;
@@ -2814,7 +2848,7 @@ static bool handle_stripe6(struct stripe_head *sh, struct page *tmp_page)
 				copy_data(0, rbi, dev->page, dev->sector);
 				rbi2 = r5_next_bio(rbi, dev->sector);
 				spin_lock_irq(&conf->device_lock);
-				if (--rbi->bi_phys_segments == 0) {
+				if (!raid5_dec_bi_phys_segments(rbi)) {
 					rbi->bi_next = return_bi;
 					return_bi = rbi;
 				}
@@ -3155,8 +3189,11 @@ static struct bio *remove_bio_from_retry(raid5_conf_t *conf)
 	if(bi) {
 		conf->retry_read_aligned_list = bi->bi_next;
 		bi->bi_next = NULL;
+		/*
+		 * this sets the active strip count to 1 and the processed
+		 * strip count to zero (upper 8 bits)
+		 */
 		bi->bi_phys_segments = 1; /* biased count of active stripes */
-		bi->bi_hw_segments = 0; /* count of processed stripes */
 	}
 
 	return bi;
@@ -3206,8 +3243,7 @@ static int bio_fits_rdev(struct bio *bi)
 	if ((bi->bi_size>>9) > q->max_sectors)
 		return 0;
 	blk_recount_segments(q, bi);
-	if (bi->bi_phys_segments > q->max_phys_segments ||
-	    bi->bi_hw_segments > q->max_hw_segments)
+	if (bi->bi_phys_segments > q->max_phys_segments)
 		return 0;
 
 	if (q->merge_bvec_fn)
@@ -3351,7 +3387,7 @@ static int make_request(struct request_queue *q, struct bio * bi)
 	sector_t logical_sector, last_sector;
 	struct stripe_head *sh;
 	const int rw = bio_data_dir(bi);
-	int remaining;
+	int cpu, remaining;
 
 	if (unlikely(bio_barrier(bi))) {
 		bio_endio(bi, -EOPNOTSUPP);
@@ -3360,8 +3396,11 @@ static int make_request(struct request_queue *q, struct bio * bi)
 
 	md_write_start(mddev, bi);
 
-	disk_stat_inc(mddev->gendisk, ios[rw]);
-	disk_stat_add(mddev->gendisk, sectors[rw], bio_sectors(bi));
+	cpu = part_stat_lock();
+	part_stat_inc(cpu, &mddev->gendisk->part0, ios[rw]);
+	part_stat_add(cpu, &mddev->gendisk->part0, sectors[rw],
+		      bio_sectors(bi));
+	part_stat_unlock();
 
 	if (rw == READ &&
 	     mddev->reshape_position == MaxSector &&
@@ -3468,7 +3507,7 @@ static int make_request(struct request_queue *q, struct bio * bi)
 			
 	}
 	spin_lock_irq(&conf->device_lock);
-	remaining = --bi->bi_phys_segments;
+	remaining = raid5_dec_bi_phys_segments(bi);
 	spin_unlock_irq(&conf->device_lock);
 	if (remaining == 0) {
 
@@ -3752,7 +3791,7 @@ static int  retry_aligned_read(raid5_conf_t *conf, struct bio *raid_bio)
 		     sector += STRIPE_SECTORS,
 		     scnt++) {
 
-		if (scnt < raid_bio->bi_hw_segments)
+		if (scnt < raid5_bi_hw_segments(raid_bio))
 			/* already done this stripe */
 			continue;
 
@@ -3760,7 +3799,7 @@ static int  retry_aligned_read(raid5_conf_t *conf, struct bio *raid_bio)
 
 		if (!sh) {
 			/* failed to get a stripe - must wait */
-			raid_bio->bi_hw_segments = scnt;
+			raid5_set_bi_hw_segments(raid_bio, scnt);
 			conf->retry_read_aligned = raid_bio;
 			return handled;
 		}
@@ -3768,7 +3807,7 @@ static int  retry_aligned_read(raid5_conf_t *conf, struct bio *raid_bio)
 		set_bit(R5_ReadError, &sh->dev[dd_idx].flags);
 		if (!add_stripe_bio(sh, raid_bio, dd_idx, 0)) {
 			release_stripe(sh);
-			raid_bio->bi_hw_segments = scnt;
+			raid5_set_bi_hw_segments(raid_bio, scnt);
 			conf->retry_read_aligned = raid_bio;
 			return handled;
 		}
@@ -3778,7 +3817,7 @@ static int  retry_aligned_read(raid5_conf_t *conf, struct bio *raid_bio)
 		handled++;
 	}
 	spin_lock_irq(&conf->device_lock);
-	remaining = --raid_bio->bi_phys_segments;
+	remaining = raid5_dec_bi_phys_segments(raid_bio);
 	spin_unlock_irq(&conf->device_lock);
 	if (remaining == 0)
 		bio_endio(raid_bio, 0);
diff --git a/drivers/memstick/core/mspro_block.c b/drivers/memstick/core/mspro_block.c
index d2d2318dafa..6e291bf8237 100644
--- a/drivers/memstick/core/mspro_block.c
+++ b/drivers/memstick/core/mspro_block.c
@@ -197,7 +197,7 @@ static int mspro_block_bd_open(struct inode *inode, struct file *filp)
 static int mspro_block_disk_release(struct gendisk *disk)
 {
 	struct mspro_block_data *msb = disk->private_data;
-	int disk_id = disk->first_minor >> MSPRO_BLOCK_PART_SHIFT;
+	int disk_id = MINOR(disk_devt(disk)) >> MSPRO_BLOCK_PART_SHIFT;
 
 	mutex_lock(&mspro_block_disk_lock);
 
@@ -828,7 +828,7 @@ static void mspro_block_submit_req(struct request_queue *q)
 
 	if (msb->eject) {
 		while ((req = elv_next_request(q)) != NULL)
-			end_queued_request(req, -ENODEV);
+			__blk_end_request(req, -ENODEV, blk_rq_bytes(req));
 
 		return;
 	}
diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index ebc8b9d7761..97156b689e8 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -83,7 +83,7 @@ static void mmc_blk_put(struct mmc_blk_data *md)
 	mutex_lock(&open_lock);
 	md->usage--;
 	if (md->usage == 0) {
-		int devidx = md->disk->first_minor >> MMC_SHIFT;
+		int devidx = MINOR(disk_devt(md->disk)) >> MMC_SHIFT;
 		__clear_bit(devidx, dev_use);
 
 		put_disk(md->disk);
diff --git a/drivers/mtd/ftl.c b/drivers/mtd/ftl.c
index f34f20c7891..9bf581c4f74 100644
--- a/drivers/mtd/ftl.c
+++ b/drivers/mtd/ftl.c
@@ -1005,6 +1005,29 @@ static int ftl_writesect(struct mtd_blktrans_dev *dev,
 	return ftl_write((void *)dev, buf, block, 1);
 }
 
+static int ftl_discardsect(struct mtd_blktrans_dev *dev,
+			   unsigned long sector, unsigned nr_sects)
+{
+	partition_t *part = (void *)dev;
+	uint32_t bsize = 1 << part->header.EraseUnitSize;
+
+	DEBUG(1, "FTL erase sector %ld for %d sectors\n",
+	      sector, nr_sects);
+
+	while (nr_sects) {
+		uint32_t old_addr = part->VirtualBlockMap[sector];
+		if (old_addr != 0xffffffff) {
+			part->VirtualBlockMap[sector] = 0xffffffff;
+			part->EUNInfo[old_addr/bsize].Deleted++;
+			if (set_bam_entry(part, old_addr, 0))
+				return -EIO;
+		}
+		nr_sects--;
+		sector++;
+	}
+
+	return 0;
+}
 /*====================================================================*/
 
 static void ftl_freepart(partition_t *part)
@@ -1069,6 +1092,7 @@ static struct mtd_blktrans_ops ftl_tr = {
 	.blksize 	= SECTOR_SIZE,
 	.readsect	= ftl_readsect,
 	.writesect	= ftl_writesect,
+	.discard	= ftl_discardsect,
 	.getgeo		= ftl_getgeo,
 	.add_mtd	= ftl_add_mtd,
 	.remove_dev	= ftl_remove_dev,
diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c
index 9ff007c4962..681d5aca2af 100644
--- a/drivers/mtd/mtd_blkdevs.c
+++ b/drivers/mtd/mtd_blkdevs.c
@@ -32,6 +32,14 @@ struct mtd_blkcore_priv {
 	spinlock_t queue_lock;
 };
 
+static int blktrans_discard_request(struct request_queue *q,
+				    struct request *req)
+{
+	req->cmd_type = REQ_TYPE_LINUX_BLOCK;
+	req->cmd[0] = REQ_LB_OP_DISCARD;
+	return 0;
+}
+
 static int do_blktrans_request(struct mtd_blktrans_ops *tr,
 			       struct mtd_blktrans_dev *dev,
 			       struct request *req)
@@ -44,6 +52,10 @@ static int do_blktrans_request(struct mtd_blktrans_ops *tr,
 
 	buf = req->buffer;
 
+	if (req->cmd_type == REQ_TYPE_LINUX_BLOCK &&
+	    req->cmd[0] == REQ_LB_OP_DISCARD)
+		return !tr->discard(dev, block, nsect);
+
 	if (!blk_fs_request(req))
 		return 0;
 
@@ -367,6 +379,10 @@ int register_mtd_blktrans(struct mtd_blktrans_ops *tr)
 
 	tr->blkcore_priv->rq->queuedata = tr;
 	blk_queue_hardsect_size(tr->blkcore_priv->rq, tr->blksize);
+	if (tr->discard)
+		blk_queue_set_discard(tr->blkcore_priv->rq,
+				      blktrans_discard_request);
+
 	tr->blkshift = ffs(tr->blksize) - 1;
 
 	tr->blkcore_priv->thread = kthread_run(mtd_blktrans_thread, tr,
diff --git a/drivers/s390/block/dasd_proc.c b/drivers/s390/block/dasd_proc.c
index 03c0e40a92f..e3b5c4d3036 100644
--- a/drivers/s390/block/dasd_proc.c
+++ b/drivers/s390/block/dasd_proc.c
@@ -76,7 +76,8 @@ dasd_devices_show(struct seq_file *m, void *v)
 	/* Print kdev. */
 	if (block->gdp)
 		seq_printf(m, " at (%3d:%6d)",
-			   block->gdp->major, block->gdp->first_minor);
+			   MAJOR(disk_devt(block->gdp)),
+			   MINOR(disk_devt(block->gdp)));
 	else
 		seq_printf(m, "  at (???:??????)");
 	/* Print device name. */
diff --git a/drivers/s390/block/dcssblk.c b/drivers/s390/block/dcssblk.c
index 711b3004b3e..9481e4a3f76 100644
--- a/drivers/s390/block/dcssblk.c
+++ b/drivers/s390/block/dcssblk.c
@@ -114,7 +114,7 @@ dcssblk_assign_free_minor(struct dcssblk_dev_info *dev_info)
 		found = 0;
 		// test if minor available
 		list_for_each_entry(entry, &dcssblk_devices, lh)
-			if (minor == entry->gd->first_minor)
+			if (minor == MINOR(disk_devt(entry->gd)))
 				found++;
 		if (!found) break; // got unused minor
 	}
@@ -397,7 +397,7 @@ dcssblk_add_store(struct device *dev, struct device_attribute *attr, const char
 		goto unload_seg;
 	}
 	sprintf(dev_info->gd->disk_name, "dcssblk%d",
-		dev_info->gd->first_minor);
+		MINOR(disk_devt(dev_info->gd)));
 	list_add_tail(&dev_info->lh, &dcssblk_devices);
 
 	if (!try_module_get(THIS_MODULE)) {
diff --git a/drivers/scsi/aacraid/aachba.c b/drivers/scsi/aacraid/aachba.c
index aa4e77c2527..8abfd06b5a7 100644
--- a/drivers/scsi/aacraid/aachba.c
+++ b/drivers/scsi/aacraid/aachba.c
@@ -1139,7 +1139,7 @@ static struct aac_srb * aac_scsi_common(struct fib * fib, struct scsi_cmnd * cmd
 	srbcmd->id       = cpu_to_le32(scmd_id(cmd));
 	srbcmd->lun      = cpu_to_le32(cmd->device->lun);
 	srbcmd->flags    = cpu_to_le32(flag);
-	timeout = cmd->timeout_per_command/HZ;
+	timeout = cmd->request->timeout/HZ;
 	if (timeout == 0)
 		timeout = 1;
 	srbcmd->timeout  = cpu_to_le32(timeout);  // timeout in seconds
diff --git a/drivers/scsi/gdth.c b/drivers/scsi/gdth.c
index 822d5214692..c387c15a212 100644
--- a/drivers/scsi/gdth.c
+++ b/drivers/scsi/gdth.c
@@ -464,7 +464,6 @@ int __gdth_execute(struct scsi_device *sdev, gdth_cmd_str *gdtcmd, char *cmnd,
 
     /* use request field to save the ptr. to completion struct. */
     scp->request = (struct request *)&wait;
-    scp->timeout_per_command = timeout*HZ;
     scp->cmd_len = 12;
     scp->cmnd = cmnd;
     cmndinfo.priority = IOCTL_PRI;
@@ -1995,23 +1994,12 @@ static void gdth_putq(gdth_ha_str *ha, Scsi_Cmnd *scp, unchar priority)
     register Scsi_Cmnd *pscp;
     register Scsi_Cmnd *nscp;
     ulong flags;
-    unchar b, t;
 
     TRACE(("gdth_putq() priority %d\n",priority));
     spin_lock_irqsave(&ha->smp_lock, flags);
 
-    if (!cmndinfo->internal_command) {
+    if (!cmndinfo->internal_command)
         cmndinfo->priority = priority;
-        b = scp->device->channel;
-        t = scp->device->id;
-        if (priority >= DEFAULT_PRI) {
-            if ((b != ha->virt_bus && ha->raw[BUS_L2P(ha,b)].lock) ||
-                (b==ha->virt_bus && t<MAX_HDRIVES && ha->hdr[t].lock)) {
-                TRACE2(("gdth_putq(): locked IO ->update_timeout()\n"));
-                cmndinfo->timeout = gdth_update_timeout(scp, 0);
-            }
-        }
-    }
 
     if (ha->req_first==NULL) {
         ha->req_first = scp;                    /* queue was empty */
@@ -3899,6 +3887,39 @@ static const char *gdth_info(struct Scsi_Host *shp)
     return ((const char *)ha->binfo.type_string);
 }
 
+static enum blk_eh_timer_return gdth_timed_out(struct scsi_cmnd *scp)
+{
+	gdth_ha_str *ha = shost_priv(scp->device->host);
+	struct gdth_cmndinfo *cmndinfo = gdth_cmnd_priv(scp);
+	unchar b, t;
+	ulong flags;
+	enum blk_eh_timer_return retval = BLK_EH_NOT_HANDLED;
+
+	TRACE(("%s() cmd 0x%x\n", scp->cmnd[0], __func__));
+	b = scp->device->channel;
+	t = scp->device->id;
+
+	/*
+	 * We don't really honor the command timeout, but we try to
+	 * honor 6 times of the actual command timeout! So reset the
+	 * timer if this is less than 6th timeout on this command!
+	 */
+	if (++cmndinfo->timeout_count < 6)
+		retval = BLK_EH_RESET_TIMER;
+
+	/* Reset the timeout if it is locked IO */
+	spin_lock_irqsave(&ha->smp_lock, flags);
+	if ((b != ha->virt_bus && ha->raw[BUS_L2P(ha, b)].lock) ||
+	    (b == ha->virt_bus && t < MAX_HDRIVES && ha->hdr[t].lock)) {
+		TRACE2(("%s(): locked IO, reset timeout\n", __func__));
+		retval = BLK_EH_RESET_TIMER;
+	}
+	spin_unlock_irqrestore(&ha->smp_lock, flags);
+
+	return retval;
+}
+
+
 static int gdth_eh_bus_reset(Scsi_Cmnd *scp)
 {
     gdth_ha_str *ha = shost_priv(scp->device->host);
@@ -3992,7 +4013,7 @@ static int gdth_queuecommand(struct scsi_cmnd *scp,
     BUG_ON(!cmndinfo);
 
     scp->scsi_done = done;
-    gdth_update_timeout(scp, scp->timeout_per_command * 6);
+    cmndinfo->timeout_count = 0;
     cmndinfo->priority = DEFAULT_PRI;
 
     return __gdth_queuecommand(ha, scp, cmndinfo);
@@ -4096,12 +4117,10 @@ static int ioc_lockdrv(void __user *arg)
             ha->hdr[j].lock = 1;
             spin_unlock_irqrestore(&ha->smp_lock, flags);
             gdth_wait_completion(ha, ha->bus_cnt, j);
-            gdth_stop_timeout(ha, ha->bus_cnt, j);
         } else {
             spin_lock_irqsave(&ha->smp_lock, flags);
             ha->hdr[j].lock = 0;
             spin_unlock_irqrestore(&ha->smp_lock, flags);
-            gdth_start_timeout(ha, ha->bus_cnt, j);
             gdth_next(ha);
         }
     } 
@@ -4539,18 +4558,14 @@ static int gdth_ioctl(struct inode *inode, struct file *filep,
                 spin_lock_irqsave(&ha->smp_lock, flags);
                 ha->raw[i].lock = 1;
                 spin_unlock_irqrestore(&ha->smp_lock, flags);
-                for (j = 0; j < ha->tid_cnt; ++j) {
+		for (j = 0; j < ha->tid_cnt; ++j)
                     gdth_wait_completion(ha, i, j);
-                    gdth_stop_timeout(ha, i, j);
-                }
             } else {
                 spin_lock_irqsave(&ha->smp_lock, flags);
                 ha->raw[i].lock = 0;
                 spin_unlock_irqrestore(&ha->smp_lock, flags);
-                for (j = 0; j < ha->tid_cnt; ++j) {
-                    gdth_start_timeout(ha, i, j);
+		for (j = 0; j < ha->tid_cnt; ++j)
                     gdth_next(ha);
-                }
             }
         } 
         break;
@@ -4644,6 +4659,7 @@ static struct scsi_host_template gdth_template = {
         .slave_configure        = gdth_slave_configure,
         .bios_param             = gdth_bios_param,
         .proc_info              = gdth_proc_info,
+	.eh_timed_out		= gdth_timed_out,
         .proc_name              = "gdth",
         .can_queue              = GDTH_MAXCMDS,
         .this_id                = -1,
diff --git a/drivers/scsi/gdth.h b/drivers/scsi/gdth.h
index ca92476727c..1646444e9bd 100644
--- a/drivers/scsi/gdth.h
+++ b/drivers/scsi/gdth.h
@@ -916,7 +916,7 @@ typedef struct {
         gdth_cmd_str *internal_cmd_str;         /* crier for internal messages*/
         dma_addr_t sense_paddr;                 /* sense dma-addr */
         unchar priority;
-        int timeout;
+	int timeout_count;			/* # of timeout calls */
         volatile int wait_for_completion;
         ushort status;
         ulong32 info;
diff --git a/drivers/scsi/gdth_proc.c b/drivers/scsi/gdth_proc.c
index ce0228e26ae..59349a316e1 100644
--- a/drivers/scsi/gdth_proc.c
+++ b/drivers/scsi/gdth_proc.c
@@ -748,69 +748,3 @@ static void gdth_wait_completion(gdth_ha_str *ha, int busnum, int id)
     }
     spin_unlock_irqrestore(&ha->smp_lock, flags);
 }
-
-static void gdth_stop_timeout(gdth_ha_str *ha, int busnum, int id)
-{
-    ulong flags;
-    Scsi_Cmnd *scp;
-    unchar b, t;
-
-    spin_lock_irqsave(&ha->smp_lock, flags);
-
-    for (scp = ha->req_first; scp; scp = (Scsi_Cmnd *)scp->SCp.ptr) {
-        struct gdth_cmndinfo *cmndinfo = gdth_cmnd_priv(scp);
-        if (!cmndinfo->internal_command) {
-            b = scp->device->channel;
-            t = scp->device->id;
-            if (t == (unchar)id && b == (unchar)busnum) {
-                TRACE2(("gdth_stop_timeout(): update_timeout()\n"));
-                cmndinfo->timeout = gdth_update_timeout(scp, 0);
-            }
-        }
-    }
-    spin_unlock_irqrestore(&ha->smp_lock, flags);
-}
-
-static void gdth_start_timeout(gdth_ha_str *ha, int busnum, int id)
-{
-    ulong flags;
-    Scsi_Cmnd *scp;
-    unchar b, t;
-
-    spin_lock_irqsave(&ha->smp_lock, flags);
-
-    for (scp = ha->req_first; scp; scp = (Scsi_Cmnd *)scp->SCp.ptr) {
-        struct gdth_cmndinfo *cmndinfo = gdth_cmnd_priv(scp);
-        if (!cmndinfo->internal_command) {
-            b = scp->device->channel;
-            t = scp->device->id;
-            if (t == (unchar)id && b == (unchar)busnum) {
-                TRACE2(("gdth_start_timeout(): update_timeout()\n"));
-                gdth_update_timeout(scp, cmndinfo->timeout);
-            }
-        }
-    }
-    spin_unlock_irqrestore(&ha->smp_lock, flags);
-}
-
-static int gdth_update_timeout(Scsi_Cmnd *scp, int timeout)
-{
-    int oldto;
-
-    oldto = scp->timeout_per_command;
-    scp->timeout_per_command = timeout;
-
-    if (timeout == 0) {
-        del_timer(&scp->eh_timeout);
-        scp->eh_timeout.data = (unsigned long) NULL;
-        scp->eh_timeout.expires = 0;
-    } else {
-        if (scp->eh_timeout.data != (unsigned long) NULL) 
-            del_timer(&scp->eh_timeout);
-        scp->eh_timeout.data = (unsigned long) scp;
-        scp->eh_timeout.expires = jiffies + timeout;
-        add_timer(&scp->eh_timeout);
-    }
-
-    return oldto;
-}
diff --git a/drivers/scsi/gdth_proc.h b/drivers/scsi/gdth_proc.h
index 45e6fdacf36..9b900cc9ebe 100644
--- a/drivers/scsi/gdth_proc.h
+++ b/drivers/scsi/gdth_proc.h
@@ -20,9 +20,6 @@ static char *gdth_ioctl_alloc(gdth_ha_str *ha, int size, int scratch,
                               ulong64 *paddr);
 static void gdth_ioctl_free(gdth_ha_str *ha, int size, char *buf, ulong64 paddr);
 static void gdth_wait_completion(gdth_ha_str *ha, int busnum, int id);
-static void gdth_stop_timeout(gdth_ha_str *ha, int busnum, int id);
-static void gdth_start_timeout(gdth_ha_str *ha, int busnum, int id);
-static int gdth_update_timeout(Scsi_Cmnd *scp, int timeout);
 
 #endif
 
diff --git a/drivers/scsi/ibmvscsi/ibmvscsi.c b/drivers/scsi/ibmvscsi/ibmvscsi.c
index 7b1502c0ab6..87e09f35d3d 100644
--- a/drivers/scsi/ibmvscsi/ibmvscsi.c
+++ b/drivers/scsi/ibmvscsi/ibmvscsi.c
@@ -756,7 +756,7 @@ static int ibmvscsi_queuecommand(struct scsi_cmnd *cmnd,
 	init_event_struct(evt_struct,
 			  handle_cmd_rsp,
 			  VIOSRP_SRP_FORMAT,
-			  cmnd->timeout_per_command/HZ);
+			  cmnd->request->timeout/HZ);
 
 	evt_struct->cmnd = cmnd;
 	evt_struct->cmnd_done = done;
diff --git a/drivers/scsi/ide-scsi.c b/drivers/scsi/ide-scsi.c
index 461331d3dc4..81c16cba541 100644
--- a/drivers/scsi/ide-scsi.c
+++ b/drivers/scsi/ide-scsi.c
@@ -612,7 +612,7 @@ static int idescsi_queue (struct scsi_cmnd *cmd,
 	pc->req_xfer = pc->buf_size = scsi_bufflen(cmd);
 	pc->scsi_cmd = cmd;
 	pc->done = done;
-	pc->timeout = jiffies + cmd->timeout_per_command;
+	pc->timeout = jiffies + cmd->request->timeout;
 
 	if (test_bit(IDESCSI_LOG_CMD, &scsi->log)) {
 		printk ("ide-scsi: %s: que %lu, cmd = ", drive->name, cmd->serial_number);
diff --git a/drivers/scsi/ipr.c b/drivers/scsi/ipr.c
index e7a3a655442..d30eb7ba018 100644
--- a/drivers/scsi/ipr.c
+++ b/drivers/scsi/ipr.c
@@ -3670,7 +3670,8 @@ static int ipr_slave_configure(struct scsi_device *sdev)
 			sdev->no_uld_attach = 1;
 		}
 		if (ipr_is_vset_device(res)) {
-			sdev->timeout = IPR_VSET_RW_TIMEOUT;
+			blk_queue_rq_timeout(sdev->request_queue,
+					     IPR_VSET_RW_TIMEOUT);
 			blk_queue_max_sectors(sdev->request_queue, IPR_VSET_MAX_SECTORS);
 		}
 		if (ipr_is_vset_device(res) || ipr_is_scsi_disk(res))
diff --git a/drivers/scsi/ips.c b/drivers/scsi/ips.c
index bc9e6ddf41d..ef683f0d2b5 100644
--- a/drivers/scsi/ips.c
+++ b/drivers/scsi/ips.c
@@ -3818,7 +3818,7 @@ ips_send_cmd(ips_ha_t * ha, ips_scb_t * scb)
 		scb->cmd.dcdb.segment_4G = 0;
 		scb->cmd.dcdb.enhanced_sg = 0;
 
-		TimeOut = scb->scsi_cmd->timeout_per_command;
+		TimeOut = scb->scsi_cmd->request->timeout;
 
 		if (ha->subsys->param[4] & 0x00100000) {	/* If NEW Tape DCDB is Supported */
 			if (!scb->sg_len) {
diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index 299e075a7b3..1eca82420aa 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -1476,12 +1476,12 @@ static void iscsi_start_tx(struct iscsi_conn *conn)
 		scsi_queue_work(conn->session->host, &conn->xmitwork);
 }
 
-static enum scsi_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *scmd)
+static enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *scmd)
 {
 	struct iscsi_cls_session *cls_session;
 	struct iscsi_session *session;
 	struct iscsi_conn *conn;
-	enum scsi_eh_timer_return rc = EH_NOT_HANDLED;
+	enum blk_eh_timer_return rc = BLK_EH_NOT_HANDLED;
 
 	cls_session = starget_to_session(scsi_target(scmd->device));
 	session = cls_session->dd_data;
@@ -1494,14 +1494,14 @@ static enum scsi_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *scmd)
 		 * We are probably in the middle of iscsi recovery so let
 		 * that complete and handle the error.
 		 */
-		rc = EH_RESET_TIMER;
+		rc = BLK_EH_RESET_TIMER;
 		goto done;
 	}
 
 	conn = session->leadconn;
 	if (!conn) {
 		/* In the middle of shuting down */
-		rc = EH_RESET_TIMER;
+		rc = BLK_EH_RESET_TIMER;
 		goto done;
 	}
 
@@ -1513,20 +1513,21 @@ static enum scsi_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *scmd)
 	 */
 	if (time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
 			    (conn->ping_timeout * HZ), jiffies))
-		rc = EH_RESET_TIMER;
+		rc = BLK_EH_RESET_TIMER;
 	/*
 	 * if we are about to check the transport then give the command
 	 * more time
 	 */
 	if (time_before_eq(conn->last_recv + (conn->recv_timeout * HZ),
 			   jiffies))
-		rc = EH_RESET_TIMER;
+		rc = BLK_EH_RESET_TIMER;
 	/* if in the middle of checking the transport then give us more time */
 	if (conn->ping_task)
-		rc = EH_RESET_TIMER;
+		rc = BLK_EH_RESET_TIMER;
 done:
 	spin_unlock(&session->lock);
-	debug_scsi("return %s\n", rc == EH_RESET_TIMER ? "timer reset" : "nh");
+	debug_scsi("return %s\n", rc == BLK_EH_RESET_TIMER ?
+					"timer reset" : "nh");
 	return rc;
 }
 
diff --git a/drivers/scsi/libsas/sas_ata.c b/drivers/scsi/libsas/sas_ata.c
index e1872989710..e1550117069 100644
--- a/drivers/scsi/libsas/sas_ata.c
+++ b/drivers/scsi/libsas/sas_ata.c
@@ -398,7 +398,7 @@ void sas_ata_task_abort(struct sas_task *task)
 
 	/* Bounce SCSI-initiated commands to the SCSI EH */
 	if (qc->scsicmd) {
-		scsi_req_abort_cmd(qc->scsicmd);
+		blk_abort_request(qc->scsicmd->request);
 		scsi_schedule_eh(qc->scsicmd->device->host);
 		return;
 	}
diff --git a/drivers/scsi/libsas/sas_internal.h b/drivers/scsi/libsas/sas_internal.h
index b4f9368f116..0001374bd6b 100644
--- a/drivers/scsi/libsas/sas_internal.h
+++ b/drivers/scsi/libsas/sas_internal.h
@@ -55,7 +55,7 @@ void sas_unregister_phys(struct sas_ha_struct *sas_ha);
 int  sas_register_ports(struct sas_ha_struct *sas_ha);
 void sas_unregister_ports(struct sas_ha_struct *sas_ha);
 
-enum scsi_eh_timer_return sas_scsi_timed_out(struct scsi_cmnd *);
+enum blk_eh_timer_return sas_scsi_timed_out(struct scsi_cmnd *);
 
 int  sas_init_queue(struct sas_ha_struct *sas_ha);
 int  sas_init_events(struct sas_ha_struct *sas_ha);
diff --git a/drivers/scsi/libsas/sas_scsi_host.c b/drivers/scsi/libsas/sas_scsi_host.c
index a8e3ef30907..744838780ad 100644
--- a/drivers/scsi/libsas/sas_scsi_host.c
+++ b/drivers/scsi/libsas/sas_scsi_host.c
@@ -673,43 +673,43 @@ out:
 	return;
 }
 
-enum scsi_eh_timer_return sas_scsi_timed_out(struct scsi_cmnd *cmd)
+enum blk_eh_timer_return sas_scsi_timed_out(struct scsi_cmnd *cmd)
 {
 	struct sas_task *task = TO_SAS_TASK(cmd);
 	unsigned long flags;
 
 	if (!task) {
-		cmd->timeout_per_command /= 2;
+		cmd->request->timeout /= 2;
 		SAS_DPRINTK("command 0x%p, task 0x%p, gone: %s\n",
-			    cmd, task, (cmd->timeout_per_command ?
-			    "EH_RESET_TIMER" : "EH_NOT_HANDLED"));
-		if (!cmd->timeout_per_command)
-			return EH_NOT_HANDLED;
-		return EH_RESET_TIMER;
+			    cmd, task, (cmd->request->timeout ?
+			    "BLK_EH_RESET_TIMER" : "BLK_EH_NOT_HANDLED"));
+		if (!cmd->request->timeout)
+			return BLK_EH_NOT_HANDLED;
+		return BLK_EH_RESET_TIMER;
 	}
 
 	spin_lock_irqsave(&task->task_state_lock, flags);
 	BUG_ON(task->task_state_flags & SAS_TASK_STATE_ABORTED);
 	if (task->task_state_flags & SAS_TASK_STATE_DONE) {
 		spin_unlock_irqrestore(&task->task_state_lock, flags);
-		SAS_DPRINTK("command 0x%p, task 0x%p, timed out: EH_HANDLED\n",
-			    cmd, task);
-		return EH_HANDLED;
+		SAS_DPRINTK("command 0x%p, task 0x%p, timed out: "
+			    "BLK_EH_HANDLED\n", cmd, task);
+		return BLK_EH_HANDLED;
 	}
 	if (!(task->task_state_flags & SAS_TASK_AT_INITIATOR)) {
 		spin_unlock_irqrestore(&task->task_state_lock, flags);
 		SAS_DPRINTK("command 0x%p, task 0x%p, not at initiator: "
-			    "EH_RESET_TIMER\n",
+			    "BLK_EH_RESET_TIMER\n",
 			    cmd, task);
-		return EH_RESET_TIMER;
+		return BLK_EH_RESET_TIMER;
 	}
 	task->task_state_flags |= SAS_TASK_STATE_ABORTED;
 	spin_unlock_irqrestore(&task->task_state_lock, flags);
 
-	SAS_DPRINTK("command 0x%p, task 0x%p, timed out: EH_NOT_HANDLED\n",
+	SAS_DPRINTK("command 0x%p, task 0x%p, timed out: BLK_EH_NOT_HANDLED\n",
 		    cmd, task);
 
-	return EH_NOT_HANDLED;
+	return BLK_EH_NOT_HANDLED;
 }
 
 int sas_ioctl(struct scsi_device *sdev, int cmd, void __user *arg)
@@ -1039,7 +1039,7 @@ void sas_task_abort(struct sas_task *task)
 		return;
 	}
 
-	scsi_req_abort_cmd(sc);
+	blk_abort_request(sc->request);
 	scsi_schedule_eh(sc->device->host);
 }
 
diff --git a/drivers/scsi/megaraid/megaraid_sas.c b/drivers/scsi/megaraid/megaraid_sas.c
index 97b763378e7..afe1de99876 100644
--- a/drivers/scsi/megaraid/megaraid_sas.c
+++ b/drivers/scsi/megaraid/megaraid_sas.c
@@ -1167,7 +1167,7 @@ static int megasas_generic_reset(struct scsi_cmnd *scmd)
  * cmd has not been completed within the timeout period.
  */
 static enum
-scsi_eh_timer_return megasas_reset_timer(struct scsi_cmnd *scmd)
+blk_eh_timer_return megasas_reset_timer(struct scsi_cmnd *scmd)
 {
 	struct megasas_cmd *cmd = (struct megasas_cmd *)scmd->SCp.ptr;
 	struct megasas_instance *instance;
@@ -1175,7 +1175,7 @@ scsi_eh_timer_return megasas_reset_timer(struct scsi_cmnd *scmd)
 
 	if (time_after(jiffies, scmd->jiffies_at_alloc +
 				(MEGASAS_DEFAULT_CMD_TIMEOUT * 2) * HZ)) {
-		return EH_NOT_HANDLED;
+		return BLK_EH_NOT_HANDLED;
 	}
 
 	instance = cmd->instance;
@@ -1189,7 +1189,7 @@ scsi_eh_timer_return megasas_reset_timer(struct scsi_cmnd *scmd)
 
 		spin_unlock_irqrestore(instance->host->host_lock, flags);
 	}
-	return EH_RESET_TIMER;
+	return BLK_EH_RESET_TIMER;
 }
 
 /**
diff --git a/drivers/scsi/ncr53c8xx.c b/drivers/scsi/ncr53c8xx.c
index c57c94c0ffd..3b7240e4081 100644
--- a/drivers/scsi/ncr53c8xx.c
+++ b/drivers/scsi/ncr53c8xx.c
@@ -4170,8 +4170,8 @@ static int ncr_queue_command (struct ncb *np, struct scsi_cmnd *cmd)
 	**
 	**----------------------------------------------------
 	*/
-	if (np->settle_time && cmd->timeout_per_command >= HZ) {
-		u_long tlimit = jiffies + cmd->timeout_per_command - HZ;
+	if (np->settle_time && cmd->request->timeout >= HZ) {
+		u_long tlimit = jiffies + cmd->request->timeout - HZ;
 		if (time_after(np->settle_time, tlimit))
 			np->settle_time = tlimit;
 	}
diff --git a/drivers/scsi/qla1280.c b/drivers/scsi/qla1280.c
index 37f9ba0cd79..b6cd12b2e99 100644
--- a/drivers/scsi/qla1280.c
+++ b/drivers/scsi/qla1280.c
@@ -2845,7 +2845,7 @@ qla1280_64bit_start_scsi(struct scsi_qla_host *ha, struct srb * sp)
 	memset(((char *)pkt + 8), 0, (REQUEST_ENTRY_SIZE - 8));
 
 	/* Set ISP command timeout. */
-	pkt->timeout = cpu_to_le16(cmd->timeout_per_command/HZ);
+	pkt->timeout = cpu_to_le16(cmd->request->timeout/HZ);
 
 	/* Set device target ID and LUN */
 	pkt->lun = SCSI_LUN_32(cmd);
@@ -3114,7 +3114,7 @@ qla1280_32bit_start_scsi(struct scsi_qla_host *ha, struct srb * sp)
 	memset(((char *)pkt + 8), 0, (REQUEST_ENTRY_SIZE - 8));
 
 	/* Set ISP command timeout. */
-	pkt->timeout = cpu_to_le16(cmd->timeout_per_command/HZ);
+	pkt->timeout = cpu_to_le16(cmd->request->timeout/HZ);
 
 	/* Set device target ID and LUN */
 	pkt->lun = SCSI_LUN_32(cmd);
diff --git a/drivers/scsi/qla4xxx/ql4_os.c b/drivers/scsi/qla4xxx/ql4_os.c
index 88bebb13bc5..de8279ad7d8 100644
--- a/drivers/scsi/qla4xxx/ql4_os.c
+++ b/drivers/scsi/qla4xxx/ql4_os.c
@@ -1542,7 +1542,7 @@ static int qla4xxx_eh_device_reset(struct scsi_cmnd *cmd)
 	DEBUG2(printk(KERN_INFO
 		      "scsi%ld: DEVICE_RESET cmd=%p jiffies = 0x%lx, to=%x,"
 		      "dpc_flags=%lx, status=%x allowed=%d\n", ha->host_no,
-		      cmd, jiffies, cmd->timeout_per_command / HZ,
+		      cmd, jiffies, cmd->request->timeout / HZ,
 		      ha->dpc_flags, cmd->result, cmd->allowed));
 
 	/* FIXME: wait for hba to go online */
@@ -1598,7 +1598,7 @@ static int qla4xxx_eh_target_reset(struct scsi_cmnd *cmd)
 	DEBUG2(printk(KERN_INFO
 		      "scsi%ld: TARGET_DEVICE_RESET cmd=%p jiffies = 0x%lx, "
 		      "to=%x,dpc_flags=%lx, status=%x allowed=%d\n",
-		      ha->host_no, cmd, jiffies, cmd->timeout_per_command / HZ,
+		      ha->host_no, cmd, jiffies, cmd->request->timeout / HZ,
 		      ha->dpc_flags, cmd->result, cmd->allowed));
 
 	stat = qla4xxx_reset_target(ha, ddb_entry);
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index ee6be596503..dbeb86cafc0 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -291,7 +291,6 @@ struct scsi_cmnd *scsi_get_command(struct scsi_device *dev, gfp_t gfp_mask)
 		unsigned long flags;
 
 		cmd->device = dev;
-		init_timer(&cmd->eh_timeout);
 		INIT_LIST_HEAD(&cmd->list);
 		spin_lock_irqsave(&dev->list_lock, flags);
 		list_add_tail(&cmd->list, &dev->cmd_list);
@@ -652,14 +651,19 @@ int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
 	unsigned long timeout;
 	int rtn = 0;
 
+	/*
+	 * We will use a queued command if possible, otherwise we will
+	 * emulate the queuing and calling of completion function ourselves.
+	 */
+	atomic_inc(&cmd->device->iorequest_cnt);
+
 	/* check if the device is still usable */
 	if (unlikely(cmd->device->sdev_state == SDEV_DEL)) {
 		/* in SDEV_DEL we error all commands. DID_NO_CONNECT
 		 * returns an immediate error upwards, and signals
 		 * that the device is no longer present */
 		cmd->result = DID_NO_CONNECT << 16;
-		atomic_inc(&cmd->device->iorequest_cnt);
-		__scsi_done(cmd);
+		scsi_done(cmd);
 		/* return 0 (because the command has been processed) */
 		goto out;
 	}
@@ -672,6 +676,7 @@ int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
 		 * future requests should not occur until the device 
 		 * transitions out of the suspend state.
 		 */
+
 		scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY);
 
 		SCSI_LOG_MLQUEUE(3, printk("queuecommand : device blocked \n"));
@@ -714,21 +719,9 @@ int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
 		host->resetting = 0;
 	}
 
-	/* 
-	 * AK: unlikely race here: for some reason the timer could
-	 * expire before the serial number is set up below.
-	 */
-	scsi_add_timer(cmd, cmd->timeout_per_command, scsi_times_out);
-
 	scsi_log_send(cmd);
 
 	/*
-	 * We will use a queued command if possible, otherwise we will
-	 * emulate the queuing and calling of completion function ourselves.
-	 */
-	atomic_inc(&cmd->device->iorequest_cnt);
-
-	/*
 	 * Before we queue this command, check if the command
 	 * length exceeds what the host adapter can handle.
 	 */
@@ -744,6 +737,12 @@ int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
 	}
 
 	spin_lock_irqsave(host->host_lock, flags);
+	/*
+	 * AK: unlikely race here: for some reason the timer could
+	 * expire before the serial number is set up below.
+	 *
+	 * TODO: kill serial or move to blk layer
+	 */
 	scsi_cmd_get_serial(host, cmd); 
 
 	if (unlikely(host->shost_state == SHOST_DEL)) {
@@ -754,12 +753,8 @@ int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
 	}
 	spin_unlock_irqrestore(host->host_lock, flags);
 	if (rtn) {
-		if (scsi_delete_timer(cmd)) {
-			atomic_inc(&cmd->device->iodone_cnt);
-			scsi_queue_insert(cmd,
-					  (rtn == SCSI_MLQUEUE_DEVICE_BUSY) ?
-					  rtn : SCSI_MLQUEUE_HOST_BUSY);
-		}
+		scsi_queue_insert(cmd, (rtn == SCSI_MLQUEUE_DEVICE_BUSY) ?
+						rtn : SCSI_MLQUEUE_HOST_BUSY);
 		SCSI_LOG_MLQUEUE(3,
 		    printk("queuecommand : request rejected\n"));
 	}
@@ -770,24 +765,6 @@ int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
 }
 
 /**
- * scsi_req_abort_cmd -- Request command recovery for the specified command
- * @cmd: pointer to the SCSI command of interest
- *
- * This function requests that SCSI Core start recovery for the
- * command by deleting the timer and adding the command to the eh
- * queue.  It can be called by either LLDDs or SCSI Core.  LLDDs who
- * implement their own error recovery MAY ignore the timeout event if
- * they generated scsi_req_abort_cmd.
- */
-void scsi_req_abort_cmd(struct scsi_cmnd *cmd)
-{
-	if (!scsi_delete_timer(cmd))
-		return;
-	scsi_times_out(cmd);
-}
-EXPORT_SYMBOL(scsi_req_abort_cmd);
-
-/**
  * scsi_done - Enqueue the finished SCSI command into the done queue.
  * @cmd: The SCSI Command for which a low-level device driver (LLDD) gives
  * ownership back to SCSI Core -- i.e. the LLDD has finished with it.
@@ -802,42 +779,7 @@ EXPORT_SYMBOL(scsi_req_abort_cmd);
  */
 static void scsi_done(struct scsi_cmnd *cmd)
 {
-	/*
-	 * We don't have to worry about this one timing out anymore.
-	 * If we are unable to remove the timer, then the command
-	 * has already timed out.  In which case, we have no choice but to
-	 * let the timeout function run, as we have no idea where in fact
-	 * that function could really be.  It might be on another processor,
-	 * etc, etc.
-	 */
-	if (!scsi_delete_timer(cmd))
-		return;
-	__scsi_done(cmd);
-}
-
-/* Private entry to scsi_done() to complete a command when the timer
- * isn't running --- used by scsi_times_out */
-void __scsi_done(struct scsi_cmnd *cmd)
-{
-	struct request *rq = cmd->request;
-
-	/*
-	 * Set the serial numbers back to zero
-	 */
-	cmd->serial_number = 0;
-
-	atomic_inc(&cmd->device->iodone_cnt);
-	if (cmd->result)
-		atomic_inc(&cmd->device->ioerr_cnt);
-
-	BUG_ON(!rq);
-
-	/*
-	 * The uptodate/nbytes values don't matter, as we allow partial
-	 * completes and thus will check this in the softirq callback
-	 */
-	rq->completion_data = cmd;
-	blk_complete_request(rq);
+	blk_complete_request(cmd->request);
 }
 
 /* Move this to a header if it becomes more generally useful */
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index 39ce3aba1da..fecefa05cb6 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -112,69 +112,8 @@ int scsi_eh_scmd_add(struct scsi_cmnd *scmd, int eh_flag)
 }
 
 /**
- * scsi_add_timer - Start timeout timer for a single scsi command.
- * @scmd:	scsi command that is about to start running.
- * @timeout:	amount of time to allow this command to run.
- * @complete:	timeout function to call if timer isn't canceled.
- *
- * Notes:
- *    This should be turned into an inline function.  Each scsi command
- *    has its own timer, and as it is added to the queue, we set up the
- *    timer.  When the command completes, we cancel the timer.
- */
-void scsi_add_timer(struct scsi_cmnd *scmd, int timeout,
-		    void (*complete)(struct scsi_cmnd *))
-{
-
-	/*
-	 * If the clock was already running for this command, then
-	 * first delete the timer.  The timer handling code gets rather
-	 * confused if we don't do this.
-	 */
-	if (scmd->eh_timeout.function)
-		del_timer(&scmd->eh_timeout);
-
-	scmd->eh_timeout.data = (unsigned long)scmd;
-	scmd->eh_timeout.expires = jiffies + timeout;
-	scmd->eh_timeout.function = (void (*)(unsigned long)) complete;
-
-	SCSI_LOG_ERROR_RECOVERY(5, printk("%s: scmd: %p, time:"
-					  " %d, (%p)\n", __func__,
-					  scmd, timeout, complete));
-
-	add_timer(&scmd->eh_timeout);
-}
-
-/**
- * scsi_delete_timer - Delete/cancel timer for a given function.
- * @scmd:	Cmd that we are canceling timer for
- *
- * Notes:
- *     This should be turned into an inline function.
- *
- * Return value:
- *     1 if we were able to detach the timer.  0 if we blew it, and the
- *     timer function has already started to run.
- */
-int scsi_delete_timer(struct scsi_cmnd *scmd)
-{
-	int rtn;
-
-	rtn = del_timer(&scmd->eh_timeout);
-
-	SCSI_LOG_ERROR_RECOVERY(5, printk("%s: scmd: %p,"
-					 " rtn: %d\n", __func__,
-					 scmd, rtn));
-
-	scmd->eh_timeout.data = (unsigned long)NULL;
-	scmd->eh_timeout.function = NULL;
-
-	return rtn;
-}
-
-/**
  * scsi_times_out - Timeout function for normal scsi commands.
- * @scmd:	Cmd that is timing out.
+ * @req:	request that is timing out.
  *
  * Notes:
  *     We do not need to lock this.  There is the potential for a race
@@ -182,9 +121,11 @@ int scsi_delete_timer(struct scsi_cmnd *scmd)
  *     normal completion function determines that the timer has already
  *     fired, then it mustn't do anything.
  */
-void scsi_times_out(struct scsi_cmnd *scmd)
+enum blk_eh_timer_return scsi_times_out(struct request *req)
 {
-	enum scsi_eh_timer_return (* eh_timed_out)(struct scsi_cmnd *);
+	struct scsi_cmnd *scmd = req->special;
+	enum blk_eh_timer_return (*eh_timed_out)(struct scsi_cmnd *);
+	enum blk_eh_timer_return rtn = BLK_EH_NOT_HANDLED;
 
 	scsi_log_completion(scmd, TIMEOUT_ERROR);
 
@@ -196,22 +137,20 @@ void scsi_times_out(struct scsi_cmnd *scmd)
 		eh_timed_out = NULL;
 
 	if (eh_timed_out)
-		switch (eh_timed_out(scmd)) {
-		case EH_HANDLED:
-			__scsi_done(scmd);
-			return;
-		case EH_RESET_TIMER:
-			scsi_add_timer(scmd, scmd->timeout_per_command,
-				       scsi_times_out);
-			return;
-		case EH_NOT_HANDLED:
+		rtn = eh_timed_out(scmd);
+		switch (rtn) {
+		case BLK_EH_NOT_HANDLED:
 			break;
+		default:
+			return rtn;
 		}
 
 	if (unlikely(!scsi_eh_scmd_add(scmd, SCSI_EH_CANCEL_CMD))) {
 		scmd->result |= DID_TIME_OUT << 16;
-		__scsi_done(scmd);
+		return BLK_EH_HANDLED;
 	}
+
+	return BLK_EH_NOT_HANDLED;
 }
 
 /**
@@ -1793,7 +1732,6 @@ scsi_reset_provider(struct scsi_device *dev, int flag)
 
 	blk_rq_init(NULL, &req);
 	scmd->request = &req;
-	memset(&scmd->eh_timeout, 0, sizeof(scmd->eh_timeout));
 
 	scmd->cmnd = req.cmd;
 
@@ -1804,8 +1742,6 @@ scsi_reset_provider(struct scsi_device *dev, int flag)
 
 	scmd->sc_data_direction		= DMA_BIDIRECTIONAL;
 
-	init_timer(&scmd->eh_timeout);
-
 	spin_lock_irqsave(shost->host_lock, flags);
 	shost->tmf_in_progress = 1;
 	spin_unlock_irqrestore(shost->host_lock, flags);
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 62307bd794a..e7686500e9d 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1181,7 +1181,6 @@ int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req)
 	
 	cmd->transfersize = req->data_len;
 	cmd->allowed = req->retries;
-	cmd->timeout_per_command = req->timeout;
 	return BLKPREP_OK;
 }
 EXPORT_SYMBOL(scsi_setup_blk_pc_cmnd);
@@ -1416,17 +1415,26 @@ static void scsi_kill_request(struct request *req, struct request_queue *q)
 	spin_unlock(shost->host_lock);
 	spin_lock(sdev->request_queue->queue_lock);
 
-	__scsi_done(cmd);
+	blk_complete_request(req);
 }
 
 static void scsi_softirq_done(struct request *rq)
 {
-	struct scsi_cmnd *cmd = rq->completion_data;
-	unsigned long wait_for = (cmd->allowed + 1) * cmd->timeout_per_command;
+	struct scsi_cmnd *cmd = rq->special;
+	unsigned long wait_for = (cmd->allowed + 1) * rq->timeout;
 	int disposition;
 
 	INIT_LIST_HEAD(&cmd->eh_entry);
 
+	/*
+	 * Set the serial numbers back to zero
+	 */
+	cmd->serial_number = 0;
+
+	atomic_inc(&cmd->device->iodone_cnt);
+	if (cmd->result)
+		atomic_inc(&cmd->device->ioerr_cnt);
+
 	disposition = scsi_decide_disposition(cmd);
 	if (disposition != SUCCESS &&
 	    time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) {
@@ -1675,6 +1683,7 @@ struct request_queue *scsi_alloc_queue(struct scsi_device *sdev)
 
 	blk_queue_prep_rq(q, scsi_prep_fn);
 	blk_queue_softirq_done(q, scsi_softirq_done);
+	blk_queue_rq_timed_out(q, scsi_times_out);
 	return q;
 }
 
diff --git a/drivers/scsi/scsi_priv.h b/drivers/scsi/scsi_priv.h
index 79f0f751120..6cddd5dd323 100644
--- a/drivers/scsi/scsi_priv.h
+++ b/drivers/scsi/scsi_priv.h
@@ -4,6 +4,7 @@
 #include <linux/device.h>
 
 struct request_queue;
+struct request;
 struct scsi_cmnd;
 struct scsi_device;
 struct scsi_host_template;
@@ -27,7 +28,6 @@ extern void scsi_exit_hosts(void);
 extern int scsi_dispatch_cmd(struct scsi_cmnd *cmd);
 extern int scsi_setup_command_freelist(struct Scsi_Host *shost);
 extern void scsi_destroy_command_freelist(struct Scsi_Host *shost);
-extern void __scsi_done(struct scsi_cmnd *cmd);
 #ifdef CONFIG_SCSI_LOGGING
 void scsi_log_send(struct scsi_cmnd *cmd);
 void scsi_log_completion(struct scsi_cmnd *cmd, int disposition);
@@ -49,10 +49,7 @@ extern int __init scsi_init_devinfo(void);
 extern void scsi_exit_devinfo(void);
 
 /* scsi_error.c */
-extern void scsi_add_timer(struct scsi_cmnd *, int,
-		void (*)(struct scsi_cmnd *));
-extern int scsi_delete_timer(struct scsi_cmnd *);
-extern void scsi_times_out(struct scsi_cmnd *cmd);
+extern enum blk_eh_timer_return scsi_times_out(struct request *req);
 extern int scsi_error_handler(void *host);
 extern int scsi_decide_disposition(struct scsi_cmnd *cmd);
 extern void scsi_eh_wakeup(struct Scsi_Host *shost);
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index ab3c71869be..7f618ee5ece 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -560,12 +560,15 @@ sdev_rd_attr (vendor, "%.8s\n");
 sdev_rd_attr (model, "%.16s\n");
 sdev_rd_attr (rev, "%.4s\n");
 
+/*
+ * TODO: can we make these symlinks to the block layer ones?
+ */
 static ssize_t
 sdev_show_timeout (struct device *dev, struct device_attribute *attr, char *buf)
 {
 	struct scsi_device *sdev;
 	sdev = to_scsi_device(dev);
-	return snprintf (buf, 20, "%d\n", sdev->timeout / HZ);
+	return snprintf(buf, 20, "%d\n", sdev->request_queue->rq_timeout / HZ);
 }
 
 static ssize_t
@@ -576,7 +579,7 @@ sdev_store_timeout (struct device *dev, struct device_attribute *attr,
 	int timeout;
 	sdev = to_scsi_device(dev);
 	sscanf (buf, "%d\n", &timeout);
-	sdev->timeout = timeout * HZ;
+	blk_queue_rq_timeout(sdev->request_queue, timeout * HZ);
 	return count;
 }
 static DEVICE_ATTR(timeout, S_IRUGO | S_IWUSR, sdev_show_timeout, sdev_store_timeout);
diff --git a/drivers/scsi/scsi_tgt_lib.c b/drivers/scsi/scsi_tgt_lib.c
index 257e097c39a..3117bb106b5 100644
--- a/drivers/scsi/scsi_tgt_lib.c
+++ b/drivers/scsi/scsi_tgt_lib.c
@@ -362,7 +362,7 @@ static int scsi_map_user_pages(struct scsi_tgt_cmd *tcmd, struct scsi_cmnd *cmd,
 	int err;
 
 	dprintk("%lx %u\n", uaddr, len);
-	err = blk_rq_map_user(q, rq, (void *)uaddr, len);
+	err = blk_rq_map_user(q, rq, NULL, (void *)uaddr, len, GFP_KERNEL);
 	if (err) {
 		/*
 		 * TODO: need to fixup sg_tablesize, max_segment_size,
diff --git a/drivers/scsi/scsi_transport_fc.c b/drivers/scsi/scsi_transport_fc.c
index 56823fd1fb8..9168883d0df 100644
--- a/drivers/scsi/scsi_transport_fc.c
+++ b/drivers/scsi/scsi_transport_fc.c
@@ -1950,15 +1950,15 @@ static int fc_vport_match(struct attribute_container *cont,
  * Notes:
  *	This routine assumes no locks are held on entry.
  */
-static enum scsi_eh_timer_return
+static enum blk_eh_timer_return
 fc_timed_out(struct scsi_cmnd *scmd)
 {
 	struct fc_rport *rport = starget_to_rport(scsi_target(scmd->device));
 
 	if (rport->port_state == FC_PORTSTATE_BLOCKED)
-		return EH_RESET_TIMER;
+		return BLK_EH_RESET_TIMER;
 
-	return EH_NOT_HANDLED;
+	return BLK_EH_NOT_HANDLED;
 }
 
 /*
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index e5e7d785645..c0cf4acda7d 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -86,6 +86,12 @@ MODULE_ALIAS_SCSI_DEVICE(TYPE_DISK);
 MODULE_ALIAS_SCSI_DEVICE(TYPE_MOD);
 MODULE_ALIAS_SCSI_DEVICE(TYPE_RBC);
 
+#if !defined(CONFIG_DEBUG_BLOCK_EXT_DEVT)
+#define SD_MINORS	16
+#else
+#define SD_MINORS	0
+#endif
+
 static int  sd_revalidate_disk(struct gendisk *);
 static int  sd_probe(struct device *);
 static int  sd_remove(struct device *);
@@ -159,7 +165,7 @@ sd_store_cache_type(struct device *dev, struct device_attribute *attr,
 			sd_print_sense_hdr(sdkp, &sshdr);
 		return -EINVAL;
 	}
-	sd_revalidate_disk(sdkp->disk);
+	revalidate_disk(sdkp->disk);
 	return count;
 }
 
@@ -377,7 +383,6 @@ static int sd_prep_fn(struct request_queue *q, struct request *rq)
 	sector_t block = rq->sector;
 	sector_t threshold;
 	unsigned int this_count = rq->nr_sectors;
-	unsigned int timeout = sdp->timeout;
 	int ret;
 
 	if (rq->cmd_type == REQ_TYPE_BLOCK_PC) {
@@ -578,7 +583,6 @@ static int sd_prep_fn(struct request_queue *q, struct request *rq)
 	SCpnt->transfersize = sdp->sector_size;
 	SCpnt->underflow = this_count << 9;
 	SCpnt->allowed = SD_MAX_RETRIES;
-	SCpnt->timeout_per_command = timeout;
 
 	/*
 	 * This indicates that the command is ready from our end to be
@@ -910,7 +914,7 @@ static void sd_rescan(struct device *dev)
 	struct scsi_disk *sdkp = scsi_disk_get_from_dev(dev);
 
 	if (sdkp) {
-		sd_revalidate_disk(sdkp->disk);
+		revalidate_disk(sdkp->disk);
 		scsi_disk_put(sdkp);
 	}
 }
@@ -1764,6 +1768,52 @@ static int sd_revalidate_disk(struct gendisk *disk)
 }
 
 /**
+ *	sd_format_disk_name - format disk name
+ *	@prefix: name prefix - ie. "sd" for SCSI disks
+ *	@index: index of the disk to format name for
+ *	@buf: output buffer
+ *	@buflen: length of the output buffer
+ *
+ *	SCSI disk names starts at sda.  The 26th device is sdz and the
+ *	27th is sdaa.  The last one for two lettered suffix is sdzz
+ *	which is followed by sdaaa.
+ *
+ *	This is basically 26 base counting with one extra 'nil' entry
+ *	at the beggining from the second digit on and can be
+ *	determined using similar method as 26 base conversion with the
+ *	index shifted -1 after each digit is computed.
+ *
+ *	CONTEXT:
+ *	Don't care.
+ *
+ *	RETURNS:
+ *	0 on success, -errno on failure.
+ */
+static int sd_format_disk_name(char *prefix, int index, char *buf, int buflen)
+{
+	const int base = 'z' - 'a' + 1;
+	char *begin = buf + strlen(prefix);
+	char *end = buf + buflen;
+	char *p;
+	int unit;
+
+	p = end - 1;
+	*p = '\0';
+	unit = base;
+	do {
+		if (p == begin)
+			return -EINVAL;
+		*--p = 'a' + (index % unit);
+		index = (index / unit) - 1;
+	} while (index >= 0);
+
+	memmove(begin, p, end - p);
+	memcpy(buf, prefix, strlen(prefix));
+
+	return 0;
+}
+
+/**
  *	sd_probe - called during driver initialization and whenever a
  *	new scsi device is attached to the system. It is called once
  *	for each scsi device (not just disks) present.
@@ -1801,7 +1851,7 @@ static int sd_probe(struct device *dev)
 	if (!sdkp)
 		goto out;
 
-	gd = alloc_disk(16);
+	gd = alloc_disk(SD_MINORS);
 	if (!gd)
 		goto out_free;
 
@@ -1815,8 +1865,8 @@ static int sd_probe(struct device *dev)
 	if (error)
 		goto out_put;
 
-	error = -EBUSY;
-	if (index >= SD_MAX_DISKS)
+	error = sd_format_disk_name("sd", index, gd->disk_name, DISK_NAME_LEN);
+	if (error)
 		goto out_free_index;
 
 	sdkp->device = sdp;
@@ -1826,11 +1876,12 @@ static int sd_probe(struct device *dev)
 	sdkp->openers = 0;
 	sdkp->previous_state = 1;
 
-	if (!sdp->timeout) {
+	if (!sdp->request_queue->rq_timeout) {
 		if (sdp->type != TYPE_MOD)
-			sdp->timeout = SD_TIMEOUT;
+			blk_queue_rq_timeout(sdp->request_queue, SD_TIMEOUT);
 		else
-			sdp->timeout = SD_MOD_TIMEOUT;
+			blk_queue_rq_timeout(sdp->request_queue,
+					     SD_MOD_TIMEOUT);
 	}
 
 	device_initialize(&sdkp->dev);
@@ -1843,24 +1894,12 @@ static int sd_probe(struct device *dev)
 
 	get_device(&sdp->sdev_gendev);
 
-	gd->major = sd_major((index & 0xf0) >> 4);
-	gd->first_minor = ((index & 0xf) << 4) | (index & 0xfff00);
-	gd->minors = 16;
-	gd->fops = &sd_fops;
-
-	if (index < 26) {
-		sprintf(gd->disk_name, "sd%c", 'a' + index % 26);
-	} else if (index < (26 + 1) * 26) {
-		sprintf(gd->disk_name, "sd%c%c",
-			'a' + index / 26 - 1,'a' + index % 26);
-	} else {
-		const unsigned int m1 = (index / 26 - 1) / 26 - 1;
-		const unsigned int m2 = (index / 26 - 1) % 26;
-		const unsigned int m3 =  index % 26;
-		sprintf(gd->disk_name, "sd%c%c%c",
-			'a' + m1, 'a' + m2, 'a' + m3);
+	if (index < SD_MAX_DISKS) {
+		gd->major = sd_major((index & 0xf0) >> 4);
+		gd->first_minor = ((index & 0xf) << 4) | (index & 0xfff00);
+		gd->minors = SD_MINORS;
 	}
-
+	gd->fops = &sd_fops;
 	gd->private_data = &sdkp->driver;
 	gd->queue = sdkp->device->request_queue;
 
@@ -1869,7 +1908,7 @@ static int sd_probe(struct device *dev)
 	blk_queue_prep_rq(sdp->request_queue, sd_prep_fn);
 
 	gd->driverfs_dev = &sdp->sdev_gendev;
-	gd->flags = GENHD_FL_DRIVERFS;
+	gd->flags = GENHD_FL_EXT_DEVT | GENHD_FL_DRIVERFS;
 	if (sdp->removable)
 		gd->flags |= GENHD_FL_REMOVABLE;
 
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 661f9f21650..ba9b9bbd4e7 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -47,7 +47,6 @@ static int sg_version_num = 30534;	/* 2 digits for each component */
 #include <linux/seq_file.h>
 #include <linux/blkdev.h>
 #include <linux/delay.h>
-#include <linux/scatterlist.h>
 #include <linux/blktrace_api.h>
 #include <linux/smp_lock.h>
 
@@ -69,7 +68,6 @@ static void sg_proc_cleanup(void);
 #endif
 
 #define SG_ALLOW_DIO_DEF 0
-#define SG_ALLOW_DIO_CODE /* compile out by commenting this define */
 
 #define SG_MAX_DEVS 32768
 
@@ -118,8 +116,8 @@ typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
 	unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
 	unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
 	unsigned bufflen;	/* Size of (aggregate) data buffer */
-	unsigned b_malloc_len;	/* actual len malloc'ed in buffer */
-	struct scatterlist *buffer;/* scatter list */
+	struct page **pages;
+	int page_order;
 	char dio_in_use;	/* 0->indirect IO (or mmap), 1->dio */
 	unsigned char cmd_opcode; /* first byte of command */
 } Sg_scatter_hold;
@@ -137,6 +135,8 @@ typedef struct sg_request {	/* SG_MAX_QUEUE requests outstanding per file */
 	char orphan;		/* 1 -> drop on sight, 0 -> normal */
 	char sg_io_owned;	/* 1 -> packet belongs to SG_IO */
 	volatile char done;	/* 0->before bh, 1->before read, 2->read */
+	struct request *rq;
+	struct bio *bio;
 } Sg_request;
 
 typedef struct sg_fd {		/* holds the state of a file descriptor */
@@ -175,8 +175,8 @@ typedef struct sg_device { /* holds the state of each scsi generic device */
 
 static int sg_fasync(int fd, struct file *filp, int mode);
 /* tasklet or soft irq callback */
-static void sg_cmd_done(void *data, char *sense, int result, int resid);
-static int sg_start_req(Sg_request * srp);
+static void sg_rq_end_io(struct request *rq, int uptodate);
+static int sg_start_req(Sg_request *srp, unsigned char *cmd);
 static void sg_finish_rem_req(Sg_request * srp);
 static int sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size);
 static int sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp,
@@ -188,17 +188,11 @@ static ssize_t sg_new_write(Sg_fd *sfp, struct file *file,
 			int read_only, Sg_request **o_srp);
 static int sg_common_write(Sg_fd * sfp, Sg_request * srp,
 			   unsigned char *cmnd, int timeout, int blocking);
-static int sg_u_iovec(sg_io_hdr_t * hp, int sg_num, int ind,
-		      int wr_xf, int *countp, unsigned char __user **up);
-static int sg_write_xfer(Sg_request * srp);
-static int sg_read_xfer(Sg_request * srp);
 static int sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer);
 static void sg_remove_scat(Sg_scatter_hold * schp);
 static void sg_build_reserve(Sg_fd * sfp, int req_size);
 static void sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size);
 static void sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp);
-static struct page *sg_page_malloc(int rqSz, int lowDma, int *retSzp);
-static void sg_page_free(struct page *page, int size);
 static Sg_fd *sg_add_sfp(Sg_device * sdp, int dev);
 static int sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
 static void __sg_remove_sfp(Sg_device * sdp, Sg_fd * sfp);
@@ -206,7 +200,6 @@ static Sg_request *sg_get_rq_mark(Sg_fd * sfp, int pack_id);
 static Sg_request *sg_add_request(Sg_fd * sfp);
 static int sg_remove_request(Sg_fd * sfp, Sg_request * srp);
 static int sg_res_in_use(Sg_fd * sfp);
-static int sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len);
 static Sg_device *sg_get_dev(int dev);
 #ifdef CONFIG_SCSI_PROC_FS
 static int sg_last_dev(void);
@@ -529,8 +522,7 @@ sg_new_read(Sg_fd * sfp, char __user *buf, size_t count, Sg_request * srp)
 		err = -EFAULT;
 		goto err_out;
 	}
-	err = sg_read_xfer(srp);
-      err_out:
+err_out:
 	sg_finish_rem_req(srp);
 	return (0 == err) ? count : err;
 }
@@ -612,7 +604,10 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
 	else
 		hp->dxfer_direction = (mxsize > 0) ? SG_DXFER_FROM_DEV : SG_DXFER_NONE;
 	hp->dxfer_len = mxsize;
-	hp->dxferp = (char __user *)buf + cmd_size;
+	if (hp->dxfer_direction == SG_DXFER_TO_DEV)
+		hp->dxferp = (char __user *)buf + cmd_size;
+	else
+		hp->dxferp = NULL;
 	hp->sbp = NULL;
 	hp->timeout = old_hdr.reply_len;	/* structure abuse ... */
 	hp->flags = input_size;	/* structure abuse ... */
@@ -732,16 +727,12 @@ sg_common_write(Sg_fd * sfp, Sg_request * srp,
 	SCSI_LOG_TIMEOUT(4, printk("sg_common_write:  scsi opcode=0x%02x, cmd_size=%d\n",
 			  (int) cmnd[0], (int) hp->cmd_len));
 
-	if ((k = sg_start_req(srp))) {
+	k = sg_start_req(srp, cmnd);
+	if (k) {
 		SCSI_LOG_TIMEOUT(1, printk("sg_common_write: start_req err=%d\n", k));
 		sg_finish_rem_req(srp);
 		return k;	/* probably out of space --> ENOMEM */
 	}
-	if ((k = sg_write_xfer(srp))) {
-		SCSI_LOG_TIMEOUT(1, printk("sg_common_write: write_xfer, bad address\n"));
-		sg_finish_rem_req(srp);
-		return k;
-	}
 	if (sdp->detached) {
 		sg_finish_rem_req(srp);
 		return -ENODEV;
@@ -763,20 +754,11 @@ sg_common_write(Sg_fd * sfp, Sg_request * srp,
 		break;
 	}
 	hp->duration = jiffies_to_msecs(jiffies);
-/* Now send everything of to mid-level. The next time we hear about this
-   packet is when sg_cmd_done() is called (i.e. a callback). */
-	if (scsi_execute_async(sdp->device, cmnd, hp->cmd_len, data_dir, srp->data.buffer,
-				hp->dxfer_len, srp->data.k_use_sg, timeout,
-				SG_DEFAULT_RETRIES, srp, sg_cmd_done,
-				GFP_ATOMIC)) {
-		SCSI_LOG_TIMEOUT(1, printk("sg_common_write: scsi_execute_async failed\n"));
-		/*
-		 * most likely out of mem, but could also be a bad map
-		 */
-		sg_finish_rem_req(srp);
-		return -ENOMEM;
-	} else
-		return 0;
+
+	srp->rq->timeout = timeout;
+	blk_execute_rq_nowait(sdp->device->request_queue, sdp->disk,
+			      srp->rq, 1, sg_rq_end_io);
+	return 0;
 }
 
 static int
@@ -1192,8 +1174,7 @@ sg_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 	Sg_fd *sfp;
 	unsigned long offset, len, sa;
 	Sg_scatter_hold *rsv_schp;
-	struct scatterlist *sg;
-	int k;
+	int k, length;
 
 	if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
 		return VM_FAULT_SIGBUS;
@@ -1203,15 +1184,14 @@ sg_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 		return VM_FAULT_SIGBUS;
 	SCSI_LOG_TIMEOUT(3, printk("sg_vma_fault: offset=%lu, scatg=%d\n",
 				   offset, rsv_schp->k_use_sg));
-	sg = rsv_schp->buffer;
 	sa = vma->vm_start;
-	for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
-	     ++k, sg = sg_next(sg)) {
+	length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
+	for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
 		len = vma->vm_end - sa;
-		len = (len < sg->length) ? len : sg->length;
+		len = (len < length) ? len : length;
 		if (offset < len) {
-			struct page *page;
-			page = virt_to_page(page_address(sg_page(sg)) + offset);
+			struct page *page = nth_page(rsv_schp->pages[k],
+						     offset >> PAGE_SHIFT);
 			get_page(page);	/* increment page count */
 			vmf->page = page;
 			return 0; /* success */
@@ -1233,8 +1213,7 @@ sg_mmap(struct file *filp, struct vm_area_struct *vma)
 	Sg_fd *sfp;
 	unsigned long req_sz, len, sa;
 	Sg_scatter_hold *rsv_schp;
-	int k;
-	struct scatterlist *sg;
+	int k, length;
 
 	if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
 		return -ENXIO;
@@ -1248,11 +1227,10 @@ sg_mmap(struct file *filp, struct vm_area_struct *vma)
 		return -ENOMEM;	/* cannot map more than reserved buffer */
 
 	sa = vma->vm_start;
-	sg = rsv_schp->buffer;
-	for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
-	     ++k, sg = sg_next(sg)) {
+	length = 1 << (PAGE_SHIFT + rsv_schp->page_order);
+	for (k = 0; k < rsv_schp->k_use_sg && sa < vma->vm_end; k++) {
 		len = vma->vm_end - sa;
-		len = (len < sg->length) ? len : sg->length;
+		len = (len < length) ? len : length;
 		sa += len;
 	}
 
@@ -1263,16 +1241,19 @@ sg_mmap(struct file *filp, struct vm_area_struct *vma)
 	return 0;
 }
 
-/* This function is a "bottom half" handler that is called by the
- * mid level when a command is completed (or has failed). */
-static void
-sg_cmd_done(void *data, char *sense, int result, int resid)
+/*
+ * This function is a "bottom half" handler that is called by the mid
+ * level when a command is completed (or has failed).
+ */
+static void sg_rq_end_io(struct request *rq, int uptodate)
 {
-	Sg_request *srp = data;
+	struct sg_request *srp = rq->end_io_data;
 	Sg_device *sdp = NULL;
 	Sg_fd *sfp;
 	unsigned long iflags;
 	unsigned int ms;
+	char *sense;
+	int result, resid;
 
 	if (NULL == srp) {
 		printk(KERN_ERR "sg_cmd_done: NULL request\n");
@@ -1286,6 +1267,9 @@ sg_cmd_done(void *data, char *sense, int result, int resid)
 		return;
 	}
 
+	sense = rq->sense;
+	result = rq->errors;
+	resid = rq->data_len;
 
 	SCSI_LOG_TIMEOUT(4, printk("sg_cmd_done: %s, pack_id=%d, res=0x%x\n",
 		sdp->disk->disk_name, srp->header.pack_id, result));
@@ -1296,7 +1280,6 @@ sg_cmd_done(void *data, char *sense, int result, int resid)
 	if (0 != result) {
 		struct scsi_sense_hdr sshdr;
 
-		memcpy(srp->sense_b, sense, sizeof (srp->sense_b));
 		srp->header.status = 0xff & result;
 		srp->header.masked_status = status_byte(result);
 		srp->header.msg_status = msg_byte(result);
@@ -1634,37 +1617,79 @@ exit_sg(void)
 	idr_destroy(&sg_index_idr);
 }
 
-static int
-sg_start_req(Sg_request * srp)
+static int sg_start_req(Sg_request *srp, unsigned char *cmd)
 {
 	int res;
+	struct request *rq;
 	Sg_fd *sfp = srp->parentfp;
 	sg_io_hdr_t *hp = &srp->header;
 	int dxfer_len = (int) hp->dxfer_len;
 	int dxfer_dir = hp->dxfer_direction;
+	unsigned int iov_count = hp->iovec_count;
 	Sg_scatter_hold *req_schp = &srp->data;
 	Sg_scatter_hold *rsv_schp = &sfp->reserve;
+	struct request_queue *q = sfp->parentdp->device->request_queue;
+	struct rq_map_data *md, map_data;
+	int rw = hp->dxfer_direction == SG_DXFER_TO_DEV ? WRITE : READ;
+
+	SCSI_LOG_TIMEOUT(4, printk(KERN_INFO "sg_start_req: dxfer_len=%d\n",
+				   dxfer_len));
+
+	rq = blk_get_request(q, rw, GFP_ATOMIC);
+	if (!rq)
+		return -ENOMEM;
+
+	memcpy(rq->cmd, cmd, hp->cmd_len);
+
+	rq->cmd_len = hp->cmd_len;
+	rq->cmd_type = REQ_TYPE_BLOCK_PC;
+
+	srp->rq = rq;
+	rq->end_io_data = srp;
+	rq->sense = srp->sense_b;
+	rq->retries = SG_DEFAULT_RETRIES;
 
-	SCSI_LOG_TIMEOUT(4, printk("sg_start_req: dxfer_len=%d\n", dxfer_len));
 	if ((dxfer_len <= 0) || (dxfer_dir == SG_DXFER_NONE))
 		return 0;
-	if (sg_allow_dio && (hp->flags & SG_FLAG_DIRECT_IO) &&
-	    (dxfer_dir != SG_DXFER_UNKNOWN) && (0 == hp->iovec_count) &&
-	    (!sfp->parentdp->device->host->unchecked_isa_dma)) {
-		res = sg_build_direct(srp, sfp, dxfer_len);
-		if (res <= 0)	/* -ve -> error, 0 -> done, 1 -> try indirect */
-			return res;
-	}
-	if ((!sg_res_in_use(sfp)) && (dxfer_len <= rsv_schp->bufflen))
-		sg_link_reserve(sfp, srp, dxfer_len);
-	else {
-		res = sg_build_indirect(req_schp, sfp, dxfer_len);
-		if (res) {
-			sg_remove_scat(req_schp);
-			return res;
+
+	if (sg_allow_dio && hp->flags & SG_FLAG_DIRECT_IO &&
+	    dxfer_dir != SG_DXFER_UNKNOWN && !iov_count &&
+	    !sfp->parentdp->device->host->unchecked_isa_dma &&
+	    blk_rq_aligned(q, hp->dxferp, dxfer_len))
+		md = NULL;
+	else
+		md = &map_data;
+
+	if (md) {
+		if (!sg_res_in_use(sfp) && dxfer_len <= rsv_schp->bufflen)
+			sg_link_reserve(sfp, srp, dxfer_len);
+		else {
+			res = sg_build_indirect(req_schp, sfp, dxfer_len);
+			if (res)
+				return res;
 		}
+
+		md->pages = req_schp->pages;
+		md->page_order = req_schp->page_order;
+		md->nr_entries = req_schp->k_use_sg;
 	}
-	return 0;
+
+	if (iov_count)
+		res = blk_rq_map_user_iov(q, rq, md, hp->dxferp, iov_count,
+					  hp->dxfer_len, GFP_ATOMIC);
+	else
+		res = blk_rq_map_user(q, rq, md, hp->dxferp,
+				      hp->dxfer_len, GFP_ATOMIC);
+
+	if (!res) {
+		srp->bio = rq->bio;
+
+		if (!md) {
+			req_schp->dio_in_use = 1;
+			hp->info |= SG_INFO_DIRECT_IO;
+		}
+	}
+	return res;
 }
 
 static void
@@ -1678,186 +1703,37 @@ sg_finish_rem_req(Sg_request * srp)
 		sg_unlink_reserve(sfp, srp);
 	else
 		sg_remove_scat(req_schp);
+
+	if (srp->rq) {
+		if (srp->bio)
+			blk_rq_unmap_user(srp->bio);
+
+		blk_put_request(srp->rq);
+	}
+
 	sg_remove_request(sfp, srp);
 }
 
 static int
 sg_build_sgat(Sg_scatter_hold * schp, const Sg_fd * sfp, int tablesize)
 {
-	int sg_bufflen = tablesize * sizeof(struct scatterlist);
+	int sg_bufflen = tablesize * sizeof(struct page *);
 	gfp_t gfp_flags = GFP_ATOMIC | __GFP_NOWARN;
 
-	/*
-	 * TODO: test without low_dma, we should not need it since
-	 * the block layer will bounce the buffer for us
-	 *
-	 * XXX(hch): we shouldn't need GFP_DMA for the actual S/G list.
-	 */
-	if (sfp->low_dma)
-		 gfp_flags |= GFP_DMA;
-	schp->buffer = kzalloc(sg_bufflen, gfp_flags);
-	if (!schp->buffer)
+	schp->pages = kzalloc(sg_bufflen, gfp_flags);
+	if (!schp->pages)
 		return -ENOMEM;
-	sg_init_table(schp->buffer, tablesize);
 	schp->sglist_len = sg_bufflen;
 	return tablesize;	/* number of scat_gath elements allocated */
 }
 
-#ifdef SG_ALLOW_DIO_CODE
-/* vvvvvvvv  following code borrowed from st driver's direct IO vvvvvvvvv */
-	/* TODO: hopefully we can use the generic block layer code */
-
-/* Pin down user pages and put them into a scatter gather list. Returns <= 0 if
-   - mapping of all pages not successful
-   (i.e., either completely successful or fails)
-*/
-static int 
-st_map_user_pages(struct scatterlist *sgl, const unsigned int max_pages, 
-	          unsigned long uaddr, size_t count, int rw)
-{
-	unsigned long end = (uaddr + count + PAGE_SIZE - 1) >> PAGE_SHIFT;
-	unsigned long start = uaddr >> PAGE_SHIFT;
-	const int nr_pages = end - start;
-	int res, i, j;
-	struct page **pages;
-
-	/* User attempted Overflow! */
-	if ((uaddr + count) < uaddr)
-		return -EINVAL;
-
-	/* Too big */
-        if (nr_pages > max_pages)
-		return -ENOMEM;
-
-	/* Hmm? */
-	if (count == 0)
-		return 0;
-
-	if ((pages = kmalloc(max_pages * sizeof(*pages), GFP_ATOMIC)) == NULL)
-		return -ENOMEM;
-
-        /* Try to fault in all of the necessary pages */
-	down_read(&current->mm->mmap_sem);
-        /* rw==READ means read from drive, write into memory area */
-	res = get_user_pages(
-		current,
-		current->mm,
-		uaddr,
-		nr_pages,
-		rw == READ,
-		0, /* don't force */
-		pages,
-		NULL);
-	up_read(&current->mm->mmap_sem);
-
-	/* Errors and no page mapped should return here */
-	if (res < nr_pages)
-		goto out_unmap;
-
-        for (i=0; i < nr_pages; i++) {
-                /* FIXME: flush superflous for rw==READ,
-                 * probably wrong function for rw==WRITE
-                 */
-		flush_dcache_page(pages[i]);
-		/* ?? Is locking needed? I don't think so */
-		/* if (!trylock_page(pages[i]))
-		   goto out_unlock; */
-        }
-
-	sg_set_page(sgl, pages[0], 0, uaddr & ~PAGE_MASK);
-	if (nr_pages > 1) {
-		sgl[0].length = PAGE_SIZE - sgl[0].offset;
-		count -= sgl[0].length;
-		for (i=1; i < nr_pages ; i++)
-			sg_set_page(&sgl[i], pages[i], count < PAGE_SIZE ? count : PAGE_SIZE, 0);
-	}
-	else {
-		sgl[0].length = count;
-	}
-
-	kfree(pages);
-	return nr_pages;
-
- out_unmap:
-	if (res > 0) {
-		for (j=0; j < res; j++)
-			page_cache_release(pages[j]);
-		res = 0;
-	}
-	kfree(pages);
-	return res;
-}
-
-
-/* And unmap them... */
-static int 
-st_unmap_user_pages(struct scatterlist *sgl, const unsigned int nr_pages,
-		    int dirtied)
-{
-	int i;
-
-	for (i=0; i < nr_pages; i++) {
-		struct page *page = sg_page(&sgl[i]);
-
-		if (dirtied)
-			SetPageDirty(page);
-		/* unlock_page(page); */
-		/* FIXME: cache flush missing for rw==READ
-		 * FIXME: call the correct reference counting function
-		 */
-		page_cache_release(page);
-	}
-
-	return 0;
-}
-
-/* ^^^^^^^^  above code borrowed from st driver's direct IO ^^^^^^^^^ */
-#endif
-
-
-/* Returns: -ve -> error, 0 -> done, 1 -> try indirect */
-static int
-sg_build_direct(Sg_request * srp, Sg_fd * sfp, int dxfer_len)
-{
-#ifdef SG_ALLOW_DIO_CODE
-	sg_io_hdr_t *hp = &srp->header;
-	Sg_scatter_hold *schp = &srp->data;
-	int sg_tablesize = sfp->parentdp->sg_tablesize;
-	int mx_sc_elems, res;
-	struct scsi_device *sdev = sfp->parentdp->device;
-
-	if (((unsigned long)hp->dxferp &
-			queue_dma_alignment(sdev->request_queue)) != 0)
-		return 1;
-
-	mx_sc_elems = sg_build_sgat(schp, sfp, sg_tablesize);
-        if (mx_sc_elems <= 0) {
-                return 1;
-        }
-	res = st_map_user_pages(schp->buffer, mx_sc_elems,
-				(unsigned long)hp->dxferp, dxfer_len, 
-				(SG_DXFER_TO_DEV == hp->dxfer_direction) ? 1 : 0);
-	if (res <= 0) {
-		sg_remove_scat(schp);
-		return 1;
-	}
-	schp->k_use_sg = res;
-	schp->dio_in_use = 1;
-	hp->info |= SG_INFO_DIRECT_IO;
-	return 0;
-#else
-	return 1;
-#endif
-}
-
 static int
 sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
 {
-	struct scatterlist *sg;
-	int ret_sz = 0, k, rem_sz, num, mx_sc_elems;
+	int ret_sz = 0, i, k, rem_sz, num, mx_sc_elems;
 	int sg_tablesize = sfp->parentdp->sg_tablesize;
-	int blk_size = buff_size;
-	struct page *p = NULL;
+	int blk_size = buff_size, order;
+	gfp_t gfp_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
 
 	if (blk_size < 0)
 		return -EFAULT;
@@ -1881,15 +1757,26 @@ sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
 		} else
 			scatter_elem_sz_prev = num;
 	}
-	for (k = 0, sg = schp->buffer, rem_sz = blk_size;
-	     (rem_sz > 0) && (k < mx_sc_elems);
-	     ++k, rem_sz -= ret_sz, sg = sg_next(sg)) {
-		
+
+	if (sfp->low_dma)
+		gfp_mask |= GFP_DMA;
+
+	if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
+		gfp_mask |= __GFP_ZERO;
+
+	order = get_order(num);
+retry:
+	ret_sz = 1 << (PAGE_SHIFT + order);
+
+	for (k = 0, rem_sz = blk_size; rem_sz > 0 && k < mx_sc_elems;
+	     k++, rem_sz -= ret_sz) {
+
 		num = (rem_sz > scatter_elem_sz_prev) ?
-		      scatter_elem_sz_prev : rem_sz;
-		p = sg_page_malloc(num, sfp->low_dma, &ret_sz);
-		if (!p)
-			return -ENOMEM;
+			scatter_elem_sz_prev : rem_sz;
+
+		schp->pages[k] = alloc_pages(gfp_mask, order);
+		if (!schp->pages[k])
+			goto out;
 
 		if (num == scatter_elem_sz_prev) {
 			if (unlikely(ret_sz > scatter_elem_sz_prev)) {
@@ -1897,12 +1784,12 @@ sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
 				scatter_elem_sz_prev = ret_sz;
 			}
 		}
-		sg_set_page(sg, p, (ret_sz > num) ? num : ret_sz, 0);
 
 		SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k=%d, num=%d, "
 				 "ret_sz=%d\n", k, num, ret_sz));
 	}		/* end of for loop */
 
+	schp->page_order = order;
 	schp->k_use_sg = k;
 	SCSI_LOG_TIMEOUT(5, printk("sg_build_indirect: k_use_sg=%d, "
 			 "rem_sz=%d\n", k, rem_sz));
@@ -1910,223 +1797,42 @@ sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size)
 	schp->bufflen = blk_size;
 	if (rem_sz > 0)	/* must have failed */
 		return -ENOMEM;
-
 	return 0;
-}
-
-static int
-sg_write_xfer(Sg_request * srp)
-{
-	sg_io_hdr_t *hp = &srp->header;
-	Sg_scatter_hold *schp = &srp->data;
-	struct scatterlist *sg = schp->buffer;
-	int num_xfer = 0;
-	int j, k, onum, usglen, ksglen, res;
-	int iovec_count = (int) hp->iovec_count;
-	int dxfer_dir = hp->dxfer_direction;
-	unsigned char *p;
-	unsigned char __user *up;
-	int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
-
-	if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_TO_DEV == dxfer_dir) ||
-	    (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
-		num_xfer = (int) (new_interface ? hp->dxfer_len : hp->flags);
-		if (schp->bufflen < num_xfer)
-			num_xfer = schp->bufflen;
-	}
-	if ((num_xfer <= 0) || (schp->dio_in_use) ||
-	    (new_interface
-	     && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
-		return 0;
-
-	SCSI_LOG_TIMEOUT(4, printk("sg_write_xfer: num_xfer=%d, iovec_count=%d, k_use_sg=%d\n",
-			  num_xfer, iovec_count, schp->k_use_sg));
-	if (iovec_count) {
-		onum = iovec_count;
-		if (!access_ok(VERIFY_READ, hp->dxferp, SZ_SG_IOVEC * onum))
-			return -EFAULT;
-	} else
-		onum = 1;
-
-	ksglen = sg->length;
-	p = page_address(sg_page(sg));
-	for (j = 0, k = 0; j < onum; ++j) {
-		res = sg_u_iovec(hp, iovec_count, j, 1, &usglen, &up);
-		if (res)
-			return res;
-
-		for (; p; sg = sg_next(sg), ksglen = sg->length,
-		     p = page_address(sg_page(sg))) {
-			if (usglen <= 0)
-				break;
-			if (ksglen > usglen) {
-				if (usglen >= num_xfer) {
-					if (__copy_from_user(p, up, num_xfer))
-						return -EFAULT;
-					return 0;
-				}
-				if (__copy_from_user(p, up, usglen))
-					return -EFAULT;
-				p += usglen;
-				ksglen -= usglen;
-				break;
-			} else {
-				if (ksglen >= num_xfer) {
-					if (__copy_from_user(p, up, num_xfer))
-						return -EFAULT;
-					return 0;
-				}
-				if (__copy_from_user(p, up, ksglen))
-					return -EFAULT;
-				up += ksglen;
-				usglen -= ksglen;
-			}
-			++k;
-			if (k >= schp->k_use_sg)
-				return 0;
-		}
-	}
-
-	return 0;
-}
+out:
+	for (i = 0; i < k; i++)
+		__free_pages(schp->pages[k], order);
 
-static int
-sg_u_iovec(sg_io_hdr_t * hp, int sg_num, int ind,
-	   int wr_xf, int *countp, unsigned char __user **up)
-{
-	int num_xfer = (int) hp->dxfer_len;
-	unsigned char __user *p = hp->dxferp;
-	int count;
+	if (--order >= 0)
+		goto retry;
 
-	if (0 == sg_num) {
-		if (wr_xf && ('\0' == hp->interface_id))
-			count = (int) hp->flags;	/* holds "old" input_size */
-		else
-			count = num_xfer;
-	} else {
-		sg_iovec_t iovec;
-		if (__copy_from_user(&iovec, p + ind*SZ_SG_IOVEC, SZ_SG_IOVEC))
-			return -EFAULT;
-		p = iovec.iov_base;
-		count = (int) iovec.iov_len;
-	}
-	if (!access_ok(wr_xf ? VERIFY_READ : VERIFY_WRITE, p, count))
-		return -EFAULT;
-	if (up)
-		*up = p;
-	if (countp)
-		*countp = count;
-	return 0;
+	return -ENOMEM;
 }
 
 static void
 sg_remove_scat(Sg_scatter_hold * schp)
 {
 	SCSI_LOG_TIMEOUT(4, printk("sg_remove_scat: k_use_sg=%d\n", schp->k_use_sg));
-	if (schp->buffer && (schp->sglist_len > 0)) {
-		struct scatterlist *sg = schp->buffer;
-
-		if (schp->dio_in_use) {
-#ifdef SG_ALLOW_DIO_CODE
-			st_unmap_user_pages(sg, schp->k_use_sg, TRUE);
-#endif
-		} else {
+	if (schp->pages && schp->sglist_len > 0) {
+		if (!schp->dio_in_use) {
 			int k;
 
-			for (k = 0; (k < schp->k_use_sg) && sg_page(sg);
-			     ++k, sg = sg_next(sg)) {
+			for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
 				SCSI_LOG_TIMEOUT(5, printk(
-				    "sg_remove_scat: k=%d, pg=0x%p, len=%d\n",
-				    k, sg_page(sg), sg->length));
-				sg_page_free(sg_page(sg), sg->length);
+				    "sg_remove_scat: k=%d, pg=0x%p\n",
+				    k, schp->pages[k]));
+				__free_pages(schp->pages[k], schp->page_order);
 			}
-		}
-		kfree(schp->buffer);
-	}
-	memset(schp, 0, sizeof (*schp));
-}
 
-static int
-sg_read_xfer(Sg_request * srp)
-{
-	sg_io_hdr_t *hp = &srp->header;
-	Sg_scatter_hold *schp = &srp->data;
-	struct scatterlist *sg = schp->buffer;
-	int num_xfer = 0;
-	int j, k, onum, usglen, ksglen, res;
-	int iovec_count = (int) hp->iovec_count;
-	int dxfer_dir = hp->dxfer_direction;
-	unsigned char *p;
-	unsigned char __user *up;
-	int new_interface = ('\0' == hp->interface_id) ? 0 : 1;
-
-	if ((SG_DXFER_UNKNOWN == dxfer_dir) || (SG_DXFER_FROM_DEV == dxfer_dir)
-	    || (SG_DXFER_TO_FROM_DEV == dxfer_dir)) {
-		num_xfer = hp->dxfer_len;
-		if (schp->bufflen < num_xfer)
-			num_xfer = schp->bufflen;
-	}
-	if ((num_xfer <= 0) || (schp->dio_in_use) ||
-	    (new_interface
-	     && ((SG_FLAG_NO_DXFER | SG_FLAG_MMAP_IO) & hp->flags)))
-		return 0;
-
-	SCSI_LOG_TIMEOUT(4, printk("sg_read_xfer: num_xfer=%d, iovec_count=%d, k_use_sg=%d\n",
-			  num_xfer, iovec_count, schp->k_use_sg));
-	if (iovec_count) {
-		onum = iovec_count;
-		if (!access_ok(VERIFY_READ, hp->dxferp, SZ_SG_IOVEC * onum))
-			return -EFAULT;
-	} else
-		onum = 1;
-
-	p = page_address(sg_page(sg));
-	ksglen = sg->length;
-	for (j = 0, k = 0; j < onum; ++j) {
-		res = sg_u_iovec(hp, iovec_count, j, 0, &usglen, &up);
-		if (res)
-			return res;
-
-		for (; p; sg = sg_next(sg), ksglen = sg->length,
-		     p = page_address(sg_page(sg))) {
-			if (usglen <= 0)
-				break;
-			if (ksglen > usglen) {
-				if (usglen >= num_xfer) {
-					if (__copy_to_user(up, p, num_xfer))
-						return -EFAULT;
-					return 0;
-				}
-				if (__copy_to_user(up, p, usglen))
-					return -EFAULT;
-				p += usglen;
-				ksglen -= usglen;
-				break;
-			} else {
-				if (ksglen >= num_xfer) {
-					if (__copy_to_user(up, p, num_xfer))
-						return -EFAULT;
-					return 0;
-				}
-				if (__copy_to_user(up, p, ksglen))
-					return -EFAULT;
-				up += ksglen;
-				usglen -= ksglen;
-			}
-			++k;
-			if (k >= schp->k_use_sg)
-				return 0;
+			kfree(schp->pages);
 		}
 	}
-
-	return 0;
+	memset(schp, 0, sizeof (*schp));
 }
 
 static int
 sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
 {
 	Sg_scatter_hold *schp = &srp->data;
-	struct scatterlist *sg = schp->buffer;
 	int k, num;
 
 	SCSI_LOG_TIMEOUT(4, printk("sg_read_oxfer: num_read_xfer=%d\n",
@@ -2134,15 +1840,15 @@ sg_read_oxfer(Sg_request * srp, char __user *outp, int num_read_xfer)
 	if ((!outp) || (num_read_xfer <= 0))
 		return 0;
 
-	for (k = 0; (k < schp->k_use_sg) && sg_page(sg); ++k, sg = sg_next(sg)) {
-		num = sg->length;
+	num = 1 << (PAGE_SHIFT + schp->page_order);
+	for (k = 0; k < schp->k_use_sg && schp->pages[k]; k++) {
 		if (num > num_read_xfer) {
-			if (__copy_to_user(outp, page_address(sg_page(sg)),
+			if (__copy_to_user(outp, page_address(schp->pages[k]),
 					   num_read_xfer))
 				return -EFAULT;
 			break;
 		} else {
-			if (__copy_to_user(outp, page_address(sg_page(sg)),
+			if (__copy_to_user(outp, page_address(schp->pages[k]),
 					   num))
 				return -EFAULT;
 			num_read_xfer -= num;
@@ -2177,24 +1883,21 @@ sg_link_reserve(Sg_fd * sfp, Sg_request * srp, int size)
 {
 	Sg_scatter_hold *req_schp = &srp->data;
 	Sg_scatter_hold *rsv_schp = &sfp->reserve;
-	struct scatterlist *sg = rsv_schp->buffer;
 	int k, num, rem;
 
 	srp->res_used = 1;
 	SCSI_LOG_TIMEOUT(4, printk("sg_link_reserve: size=%d\n", size));
 	rem = size;
 
-	for (k = 0; k < rsv_schp->k_use_sg; ++k, sg = sg_next(sg)) {
-		num = sg->length;
+	num = 1 << (PAGE_SHIFT + rsv_schp->page_order);
+	for (k = 0; k < rsv_schp->k_use_sg; k++) {
 		if (rem <= num) {
-			sfp->save_scat_len = num;
-			sg->length = rem;
 			req_schp->k_use_sg = k + 1;
 			req_schp->sglist_len = rsv_schp->sglist_len;
-			req_schp->buffer = rsv_schp->buffer;
+			req_schp->pages = rsv_schp->pages;
 
 			req_schp->bufflen = size;
-			req_schp->b_malloc_len = rsv_schp->b_malloc_len;
+			req_schp->page_order = rsv_schp->page_order;
 			break;
 		} else
 			rem -= num;
@@ -2208,22 +1911,13 @@ static void
 sg_unlink_reserve(Sg_fd * sfp, Sg_request * srp)
 {
 	Sg_scatter_hold *req_schp = &srp->data;
-	Sg_scatter_hold *rsv_schp = &sfp->reserve;
 
 	SCSI_LOG_TIMEOUT(4, printk("sg_unlink_reserve: req->k_use_sg=%d\n",
 				   (int) req_schp->k_use_sg));
-	if ((rsv_schp->k_use_sg > 0) && (req_schp->k_use_sg > 0)) {
-		struct scatterlist *sg = rsv_schp->buffer;
-
-		if (sfp->save_scat_len > 0)
-			(sg + (req_schp->k_use_sg - 1))->length =
-			    (unsigned) sfp->save_scat_len;
-		else
-			SCSI_LOG_TIMEOUT(1, printk ("sg_unlink_reserve: BAD save_scat_len\n"));
-	}
 	req_schp->k_use_sg = 0;
 	req_schp->bufflen = 0;
-	req_schp->buffer = NULL;
+	req_schp->pages = NULL;
+	req_schp->page_order = 0;
 	req_schp->sglist_len = 0;
 	sfp->save_scat_len = 0;
 	srp->res_used = 0;
@@ -2481,53 +2175,6 @@ sg_res_in_use(Sg_fd * sfp)
 	return srp ? 1 : 0;
 }
 
-/* The size fetched (value output via retSzp) set when non-NULL return */
-static struct page *
-sg_page_malloc(int rqSz, int lowDma, int *retSzp)
-{
-	struct page *resp = NULL;
-	gfp_t page_mask;
-	int order, a_size;
-	int resSz;
-
-	if ((rqSz <= 0) || (NULL == retSzp))
-		return resp;
-
-	if (lowDma)
-		page_mask = GFP_ATOMIC | GFP_DMA | __GFP_COMP | __GFP_NOWARN;
-	else
-		page_mask = GFP_ATOMIC | __GFP_COMP | __GFP_NOWARN;
-
-	for (order = 0, a_size = PAGE_SIZE; a_size < rqSz;
-	     order++, a_size <<= 1) ;
-	resSz = a_size;		/* rounded up if necessary */
-	resp = alloc_pages(page_mask, order);
-	while ((!resp) && order) {
-		--order;
-		a_size >>= 1;	/* divide by 2, until PAGE_SIZE */
-		resp =  alloc_pages(page_mask, order);	/* try half */
-		resSz = a_size;
-	}
-	if (resp) {
-		if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
-			memset(page_address(resp), 0, resSz);
-		*retSzp = resSz;
-	}
-	return resp;
-}
-
-static void
-sg_page_free(struct page *page, int size)
-{
-	int order, a_size;
-
-	if (!page)
-		return;
-	for (order = 0, a_size = PAGE_SIZE; a_size < size;
-	     order++, a_size <<= 1) ;
-	__free_pages(page, order);
-}
-
 #ifdef CONFIG_SCSI_PROC_FS
 static int
 sg_idr_max_id(int id, void *p, void *data)
diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
index 27f5bfd1def..0f17009c99d 100644
--- a/drivers/scsi/sr.c
+++ b/drivers/scsi/sr.c
@@ -331,7 +331,7 @@ static int sr_done(struct scsi_cmnd *SCpnt)
 
 static int sr_prep_fn(struct request_queue *q, struct request *rq)
 {
-	int block=0, this_count, s_size, timeout = SR_TIMEOUT;
+	int block = 0, this_count, s_size;
 	struct scsi_cd *cd;
 	struct scsi_cmnd *SCpnt;
 	struct scsi_device *sdp = q->queuedata;
@@ -461,7 +461,6 @@ static int sr_prep_fn(struct request_queue *q, struct request *rq)
 	SCpnt->transfersize = cd->device->sector_size;
 	SCpnt->underflow = this_count << 9;
 	SCpnt->allowed = MAX_RETRIES;
-	SCpnt->timeout_per_command = timeout;
 
 	/*
 	 * This indicates that the command is ready from our end to be
@@ -620,6 +619,8 @@ static int sr_probe(struct device *dev)
 	disk->fops = &sr_bdops;
 	disk->flags = GENHD_FL_CD;
 
+	blk_queue_rq_timeout(sdev->request_queue, SR_TIMEOUT);
+
 	cd->device = sdev;
 	cd->disk = disk;
 	cd->driver = &sr_template;
@@ -878,7 +879,7 @@ static void sr_kref_release(struct kref *kref)
 	struct gendisk *disk = cd->disk;
 
 	spin_lock(&sr_index_lock);
-	clear_bit(disk->first_minor, sr_index_bits);
+	clear_bit(MINOR(disk_devt(disk)), sr_index_bits);
 	spin_unlock(&sr_index_lock);
 
 	unregister_cdrom(&cd->cdi);
diff --git a/drivers/scsi/sym53c8xx_2/sym_glue.c b/drivers/scsi/sym53c8xx_2/sym_glue.c
index d39107b7669..f4e6cde1fd0 100644
--- a/drivers/scsi/sym53c8xx_2/sym_glue.c
+++ b/drivers/scsi/sym53c8xx_2/sym_glue.c
@@ -519,8 +519,8 @@ static int sym53c8xx_queue_command(struct scsi_cmnd *cmd,
 	 *  Shorten our settle_time if needed for 
 	 *  this command not to time out.
 	 */
-	if (np->s.settle_time_valid && cmd->timeout_per_command) {
-		unsigned long tlimit = jiffies + cmd->timeout_per_command;
+	if (np->s.settle_time_valid && cmd->request->timeout) {
+		unsigned long tlimit = jiffies + cmd->request->timeout;
 		tlimit -= SYM_CONF_TIMER_INTERVAL*2;
 		if (time_after(np->s.settle_time, tlimit)) {
 			np->s.settle_time = tlimit;
diff --git a/fs/bio-integrity.c b/fs/bio-integrity.c
index c3e174b35fe..19caf7c962a 100644
--- a/fs/bio-integrity.c
+++ b/fs/bio-integrity.c
@@ -107,7 +107,8 @@ void bio_integrity_free(struct bio *bio, struct bio_set *bs)
 	BUG_ON(bip == NULL);
 
 	/* A cloned bio doesn't own the integrity metadata */
-	if (!bio_flagged(bio, BIO_CLONED) && bip->bip_buf != NULL)
+	if (!bio_flagged(bio, BIO_CLONED) && !bio_flagged(bio, BIO_FS_INTEGRITY)
+	    && bip->bip_buf != NULL)
 		kfree(bip->bip_buf);
 
 	mempool_free(bip->bip_vec, bs->bvec_pools[bip->bip_pool]);
@@ -150,6 +151,24 @@ int bio_integrity_add_page(struct bio *bio, struct page *page,
 }
 EXPORT_SYMBOL(bio_integrity_add_page);
 
+static int bdev_integrity_enabled(struct block_device *bdev, int rw)
+{
+	struct blk_integrity *bi = bdev_get_integrity(bdev);
+
+	if (bi == NULL)
+		return 0;
+
+	if (rw == READ && bi->verify_fn != NULL &&
+	    (bi->flags & INTEGRITY_FLAG_READ))
+		return 1;
+
+	if (rw == WRITE && bi->generate_fn != NULL &&
+	    (bi->flags & INTEGRITY_FLAG_WRITE))
+		return 1;
+
+	return 0;
+}
+
 /**
  * bio_integrity_enabled - Check whether integrity can be passed
  * @bio:	bio to check
@@ -313,6 +332,14 @@ static void bio_integrity_generate(struct bio *bio)
 	}
 }
 
+static inline unsigned short blk_integrity_tuple_size(struct blk_integrity *bi)
+{
+	if (bi)
+		return bi->tuple_size;
+
+	return 0;
+}
+
 /**
  * bio_integrity_prep - Prepare bio for integrity I/O
  * @bio:	bio to prepare
diff --git a/fs/bio.c b/fs/bio.c
index 3cba7ae34d7..77a55bcceed 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -30,7 +30,7 @@
 
 static struct kmem_cache *bio_slab __read_mostly;
 
-mempool_t *bio_split_pool __read_mostly;
+static mempool_t *bio_split_pool __read_mostly;
 
 /*
  * if you change this list, also change bvec_alloc or things will
@@ -60,25 +60,46 @@ struct bio_vec *bvec_alloc_bs(gfp_t gfp_mask, int nr, unsigned long *idx, struct
 	struct bio_vec *bvl;
 
 	/*
-	 * see comment near bvec_array define!
+	 * If 'bs' is given, lookup the pool and do the mempool alloc.
+	 * If not, this is a bio_kmalloc() allocation and just do a
+	 * kzalloc() for the exact number of vecs right away.
 	 */
-	switch (nr) {
-		case   1        : *idx = 0; break;
-		case   2 ...   4: *idx = 1; break;
-		case   5 ...  16: *idx = 2; break;
-		case  17 ...  64: *idx = 3; break;
-		case  65 ... 128: *idx = 4; break;
-		case 129 ... BIO_MAX_PAGES: *idx = 5; break;
+	if (bs) {
+		/*
+		 * see comment near bvec_array define!
+		 */
+		switch (nr) {
+		case 1:
+			*idx = 0;
+			break;
+		case 2 ... 4:
+			*idx = 1;
+			break;
+		case 5 ... 16:
+			*idx = 2;
+			break;
+		case 17 ... 64:
+			*idx = 3;
+			break;
+		case 65 ... 128:
+			*idx = 4;
+			break;
+		case 129 ... BIO_MAX_PAGES:
+			*idx = 5;
+			break;
 		default:
 			return NULL;
-	}
-	/*
-	 * idx now points to the pool we want to allocate from
-	 */
+		}
 
-	bvl = mempool_alloc(bs->bvec_pools[*idx], gfp_mask);
-	if (bvl)
-		memset(bvl, 0, bvec_nr_vecs(*idx) * sizeof(struct bio_vec));
+		/*
+		 * idx now points to the pool we want to allocate from
+		 */
+		bvl = mempool_alloc(bs->bvec_pools[*idx], gfp_mask);
+		if (bvl)
+			memset(bvl, 0,
+				bvec_nr_vecs(*idx) * sizeof(struct bio_vec));
+	} else
+		bvl = kzalloc(nr * sizeof(struct bio_vec), gfp_mask);
 
 	return bvl;
 }
@@ -107,10 +128,17 @@ static void bio_fs_destructor(struct bio *bio)
 	bio_free(bio, fs_bio_set);
 }
 
+static void bio_kmalloc_destructor(struct bio *bio)
+{
+	kfree(bio->bi_io_vec);
+	kfree(bio);
+}
+
 void bio_init(struct bio *bio)
 {
 	memset(bio, 0, sizeof(*bio));
 	bio->bi_flags = 1 << BIO_UPTODATE;
+	bio->bi_comp_cpu = -1;
 	atomic_set(&bio->bi_cnt, 1);
 }
 
@@ -118,19 +146,25 @@ void bio_init(struct bio *bio)
  * bio_alloc_bioset - allocate a bio for I/O
  * @gfp_mask:   the GFP_ mask given to the slab allocator
  * @nr_iovecs:	number of iovecs to pre-allocate
- * @bs:		the bio_set to allocate from
+ * @bs:		the bio_set to allocate from. If %NULL, just use kmalloc
  *
  * Description:
- *   bio_alloc_bioset will first try it's on mempool to satisfy the allocation.
+ *   bio_alloc_bioset will first try its own mempool to satisfy the allocation.
  *   If %__GFP_WAIT is set then we will block on the internal pool waiting
- *   for a &struct bio to become free.
+ *   for a &struct bio to become free. If a %NULL @bs is passed in, we will
+ *   fall back to just using @kmalloc to allocate the required memory.
  *
  *   allocate bio and iovecs from the memory pools specified by the
- *   bio_set structure.
+ *   bio_set structure, or @kmalloc if none given.
  **/
 struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs)
 {
-	struct bio *bio = mempool_alloc(bs->bio_pool, gfp_mask);
+	struct bio *bio;
+
+	if (bs)
+		bio = mempool_alloc(bs->bio_pool, gfp_mask);
+	else
+		bio = kmalloc(sizeof(*bio), gfp_mask);
 
 	if (likely(bio)) {
 		struct bio_vec *bvl = NULL;
@@ -141,7 +175,10 @@ struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs)
 
 			bvl = bvec_alloc_bs(gfp_mask, nr_iovecs, &idx, bs);
 			if (unlikely(!bvl)) {
-				mempool_free(bio, bs->bio_pool);
+				if (bs)
+					mempool_free(bio, bs->bio_pool);
+				else
+					kfree(bio);
 				bio = NULL;
 				goto out;
 			}
@@ -164,6 +201,23 @@ struct bio *bio_alloc(gfp_t gfp_mask, int nr_iovecs)
 	return bio;
 }
 
+/*
+ * Like bio_alloc(), but doesn't use a mempool backing. This means that
+ * it CAN fail, but while bio_alloc() can only be used for allocations
+ * that have a short (finite) life span, bio_kmalloc() should be used
+ * for more permanent bio allocations (like allocating some bio's for
+ * initalization or setup purposes).
+ */
+struct bio *bio_kmalloc(gfp_t gfp_mask, int nr_iovecs)
+{
+	struct bio *bio = bio_alloc_bioset(gfp_mask, nr_iovecs, NULL);
+
+	if (bio)
+		bio->bi_destructor = bio_kmalloc_destructor;
+
+	return bio;
+}
+
 void zero_fill_bio(struct bio *bio)
 {
 	unsigned long flags;
@@ -208,14 +262,6 @@ inline int bio_phys_segments(struct request_queue *q, struct bio *bio)
 	return bio->bi_phys_segments;
 }
 
-inline int bio_hw_segments(struct request_queue *q, struct bio *bio)
-{
-	if (unlikely(!bio_flagged(bio, BIO_SEG_VALID)))
-		blk_recount_segments(q, bio);
-
-	return bio->bi_hw_segments;
-}
-
 /**
  * 	__bio_clone	-	clone a bio
  * 	@bio: destination bio
@@ -350,8 +396,7 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page
 	 */
 
 	while (bio->bi_phys_segments >= q->max_phys_segments
-	       || bio->bi_hw_segments >= q->max_hw_segments
-	       || BIOVEC_VIRT_OVERSIZE(bio->bi_size)) {
+	       || bio->bi_phys_segments >= q->max_hw_segments) {
 
 		if (retried_segments)
 			return 0;
@@ -395,13 +440,11 @@ static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page
 	}
 
 	/* If we may be able to merge these biovecs, force a recount */
-	if (bio->bi_vcnt && (BIOVEC_PHYS_MERGEABLE(bvec-1, bvec) ||
-	    BIOVEC_VIRT_MERGEABLE(bvec-1, bvec)))
+	if (bio->bi_vcnt && (BIOVEC_PHYS_MERGEABLE(bvec-1, bvec)))
 		bio->bi_flags &= ~(1 << BIO_SEG_VALID);
 
 	bio->bi_vcnt++;
 	bio->bi_phys_segments++;
-	bio->bi_hw_segments++;
  done:
 	bio->bi_size += len;
 	return len;
@@ -449,16 +492,19 @@ int bio_add_page(struct bio *bio, struct page *page, unsigned int len,
 
 struct bio_map_data {
 	struct bio_vec *iovecs;
-	int nr_sgvecs;
 	struct sg_iovec *sgvecs;
+	int nr_sgvecs;
+	int is_our_pages;
 };
 
 static void bio_set_map_data(struct bio_map_data *bmd, struct bio *bio,
-			     struct sg_iovec *iov, int iov_count)
+			     struct sg_iovec *iov, int iov_count,
+			     int is_our_pages)
 {
 	memcpy(bmd->iovecs, bio->bi_io_vec, sizeof(struct bio_vec) * bio->bi_vcnt);
 	memcpy(bmd->sgvecs, iov, sizeof(struct sg_iovec) * iov_count);
 	bmd->nr_sgvecs = iov_count;
+	bmd->is_our_pages = is_our_pages;
 	bio->bi_private = bmd;
 }
 
@@ -493,7 +539,8 @@ static struct bio_map_data *bio_alloc_map_data(int nr_segs, int iov_count,
 }
 
 static int __bio_copy_iov(struct bio *bio, struct bio_vec *iovecs,
-			  struct sg_iovec *iov, int iov_count, int uncopy)
+			  struct sg_iovec *iov, int iov_count, int uncopy,
+			  int do_free_page)
 {
 	int ret = 0, i;
 	struct bio_vec *bvec;
@@ -536,7 +583,7 @@ static int __bio_copy_iov(struct bio *bio, struct bio_vec *iovecs,
 			}
 		}
 
-		if (uncopy)
+		if (do_free_page)
 			__free_page(bvec->bv_page);
 	}
 
@@ -553,10 +600,11 @@ static int __bio_copy_iov(struct bio *bio, struct bio_vec *iovecs,
 int bio_uncopy_user(struct bio *bio)
 {
 	struct bio_map_data *bmd = bio->bi_private;
-	int ret;
-
-	ret = __bio_copy_iov(bio, bmd->iovecs, bmd->sgvecs, bmd->nr_sgvecs, 1);
+	int ret = 0;
 
+	if (!bio_flagged(bio, BIO_NULL_MAPPED))
+		ret = __bio_copy_iov(bio, bmd->iovecs, bmd->sgvecs,
+				     bmd->nr_sgvecs, 1, bmd->is_our_pages);
 	bio_free_map_data(bmd);
 	bio_put(bio);
 	return ret;
@@ -565,16 +613,20 @@ int bio_uncopy_user(struct bio *bio)
 /**
  *	bio_copy_user_iov	-	copy user data to bio
  *	@q: destination block queue
+ *	@map_data: pointer to the rq_map_data holding pages (if necessary)
  *	@iov:	the iovec.
  *	@iov_count: number of elements in the iovec
  *	@write_to_vm: bool indicating writing to pages or not
+ *	@gfp_mask: memory allocation flags
  *
  *	Prepares and returns a bio for indirect user io, bouncing data
  *	to/from kernel pages as necessary. Must be paired with
  *	call bio_uncopy_user() on io completion.
  */
-struct bio *bio_copy_user_iov(struct request_queue *q, struct sg_iovec *iov,
-			      int iov_count, int write_to_vm)
+struct bio *bio_copy_user_iov(struct request_queue *q,
+			      struct rq_map_data *map_data,
+			      struct sg_iovec *iov, int iov_count,
+			      int write_to_vm, gfp_t gfp_mask)
 {
 	struct bio_map_data *bmd;
 	struct bio_vec *bvec;
@@ -597,25 +649,38 @@ struct bio *bio_copy_user_iov(struct request_queue *q, struct sg_iovec *iov,
 		len += iov[i].iov_len;
 	}
 
-	bmd = bio_alloc_map_data(nr_pages, iov_count, GFP_KERNEL);
+	bmd = bio_alloc_map_data(nr_pages, iov_count, gfp_mask);
 	if (!bmd)
 		return ERR_PTR(-ENOMEM);
 
 	ret = -ENOMEM;
-	bio = bio_alloc(GFP_KERNEL, nr_pages);
+	bio = bio_alloc(gfp_mask, nr_pages);
 	if (!bio)
 		goto out_bmd;
 
 	bio->bi_rw |= (!write_to_vm << BIO_RW);
 
 	ret = 0;
+	i = 0;
 	while (len) {
-		unsigned int bytes = PAGE_SIZE;
+		unsigned int bytes;
+
+		if (map_data)
+			bytes = 1U << (PAGE_SHIFT + map_data->page_order);
+		else
+			bytes = PAGE_SIZE;
 
 		if (bytes > len)
 			bytes = len;
 
-		page = alloc_page(q->bounce_gfp | GFP_KERNEL);
+		if (map_data) {
+			if (i == map_data->nr_entries) {
+				ret = -ENOMEM;
+				break;
+			}
+			page = map_data->pages[i++];
+		} else
+			page = alloc_page(q->bounce_gfp | gfp_mask);
 		if (!page) {
 			ret = -ENOMEM;
 			break;
@@ -634,16 +699,17 @@ struct bio *bio_copy_user_iov(struct request_queue *q, struct sg_iovec *iov,
 	 * success
 	 */
 	if (!write_to_vm) {
-		ret = __bio_copy_iov(bio, bio->bi_io_vec, iov, iov_count, 0);
+		ret = __bio_copy_iov(bio, bio->bi_io_vec, iov, iov_count, 0, 0);
 		if (ret)
 			goto cleanup;
 	}
 
-	bio_set_map_data(bmd, bio, iov, iov_count);
+	bio_set_map_data(bmd, bio, iov, iov_count, map_data ? 0 : 1);
 	return bio;
 cleanup:
-	bio_for_each_segment(bvec, bio, i)
-		__free_page(bvec->bv_page);
+	if (!map_data)
+		bio_for_each_segment(bvec, bio, i)
+			__free_page(bvec->bv_page);
 
 	bio_put(bio);
 out_bmd:
@@ -654,29 +720,32 @@ out_bmd:
 /**
  *	bio_copy_user	-	copy user data to bio
  *	@q: destination block queue
+ *	@map_data: pointer to the rq_map_data holding pages (if necessary)
  *	@uaddr: start of user address
  *	@len: length in bytes
  *	@write_to_vm: bool indicating writing to pages or not
+ *	@gfp_mask: memory allocation flags
  *
  *	Prepares and returns a bio for indirect user io, bouncing data
  *	to/from kernel pages as necessary. Must be paired with
  *	call bio_uncopy_user() on io completion.
  */
-struct bio *bio_copy_user(struct request_queue *q, unsigned long uaddr,
-			  unsigned int len, int write_to_vm)
+struct bio *bio_copy_user(struct request_queue *q, struct rq_map_data *map_data,
+			  unsigned long uaddr, unsigned int len,
+			  int write_to_vm, gfp_t gfp_mask)
 {
 	struct sg_iovec iov;
 
 	iov.iov_base = (void __user *)uaddr;
 	iov.iov_len = len;
 
-	return bio_copy_user_iov(q, &iov, 1, write_to_vm);
+	return bio_copy_user_iov(q, map_data, &iov, 1, write_to_vm, gfp_mask);
 }
 
 static struct bio *__bio_map_user_iov(struct request_queue *q,
 				      struct block_device *bdev,
 				      struct sg_iovec *iov, int iov_count,
-				      int write_to_vm)
+				      int write_to_vm, gfp_t gfp_mask)
 {
 	int i, j;
 	int nr_pages = 0;
@@ -702,12 +771,12 @@ static struct bio *__bio_map_user_iov(struct request_queue *q,
 	if (!nr_pages)
 		return ERR_PTR(-EINVAL);
 
-	bio = bio_alloc(GFP_KERNEL, nr_pages);
+	bio = bio_alloc(gfp_mask, nr_pages);
 	if (!bio)
 		return ERR_PTR(-ENOMEM);
 
 	ret = -ENOMEM;
-	pages = kcalloc(nr_pages, sizeof(struct page *), GFP_KERNEL);
+	pages = kcalloc(nr_pages, sizeof(struct page *), gfp_mask);
 	if (!pages)
 		goto out;
 
@@ -786,19 +855,21 @@ static struct bio *__bio_map_user_iov(struct request_queue *q,
  *	@uaddr: start of user address
  *	@len: length in bytes
  *	@write_to_vm: bool indicating writing to pages or not
+ *	@gfp_mask: memory allocation flags
  *
  *	Map the user space address into a bio suitable for io to a block
  *	device. Returns an error pointer in case of error.
  */
 struct bio *bio_map_user(struct request_queue *q, struct block_device *bdev,
-			 unsigned long uaddr, unsigned int len, int write_to_vm)
+			 unsigned long uaddr, unsigned int len, int write_to_vm,
+			 gfp_t gfp_mask)
 {
 	struct sg_iovec iov;
 
 	iov.iov_base = (void __user *)uaddr;
 	iov.iov_len = len;
 
-	return bio_map_user_iov(q, bdev, &iov, 1, write_to_vm);
+	return bio_map_user_iov(q, bdev, &iov, 1, write_to_vm, gfp_mask);
 }
 
 /**
@@ -808,18 +879,19 @@ struct bio *bio_map_user(struct request_queue *q, struct block_device *bdev,
  *	@iov:	the iovec.
  *	@iov_count: number of elements in the iovec
  *	@write_to_vm: bool indicating writing to pages or not
+ *	@gfp_mask: memory allocation flags
  *
  *	Map the user space address into a bio suitable for io to a block
  *	device. Returns an error pointer in case of error.
  */
 struct bio *bio_map_user_iov(struct request_queue *q, struct block_device *bdev,
 			     struct sg_iovec *iov, int iov_count,
-			     int write_to_vm)
+			     int write_to_vm, gfp_t gfp_mask)
 {
 	struct bio *bio;
 
-	bio = __bio_map_user_iov(q, bdev, iov, iov_count, write_to_vm);
-
+	bio = __bio_map_user_iov(q, bdev, iov, iov_count, write_to_vm,
+				 gfp_mask);
 	if (IS_ERR(bio))
 		return bio;
 
@@ -976,48 +1048,13 @@ static void bio_copy_kern_endio(struct bio *bio, int err)
 struct bio *bio_copy_kern(struct request_queue *q, void *data, unsigned int len,
 			  gfp_t gfp_mask, int reading)
 {
-	unsigned long kaddr = (unsigned long)data;
-	unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
-	unsigned long start = kaddr >> PAGE_SHIFT;
-	const int nr_pages = end - start;
 	struct bio *bio;
 	struct bio_vec *bvec;
-	struct bio_map_data *bmd;
-	int i, ret;
-	struct sg_iovec iov;
-
-	iov.iov_base = data;
-	iov.iov_len = len;
-
-	bmd = bio_alloc_map_data(nr_pages, 1, gfp_mask);
-	if (!bmd)
-		return ERR_PTR(-ENOMEM);
-
-	ret = -ENOMEM;
-	bio = bio_alloc(gfp_mask, nr_pages);
-	if (!bio)
-		goto out_bmd;
-
-	while (len) {
-		struct page *page;
-		unsigned int bytes = PAGE_SIZE;
-
-		if (bytes > len)
-			bytes = len;
-
-		page = alloc_page(q->bounce_gfp | gfp_mask);
-		if (!page) {
-			ret = -ENOMEM;
-			goto cleanup;
-		}
-
-		if (bio_add_pc_page(q, bio, page, bytes, 0) < bytes) {
-			ret = -EINVAL;
-			goto cleanup;
-		}
+	int i;
 
-		len -= bytes;
-	}
+	bio = bio_copy_user(q, NULL, (unsigned long)data, len, 1, gfp_mask);
+	if (IS_ERR(bio))
+		return bio;
 
 	if (!reading) {
 		void *p = data;
@@ -1030,20 +1067,9 @@ struct bio *bio_copy_kern(struct request_queue *q, void *data, unsigned int len,
 		}
 	}
 
-	bio->bi_private = bmd;
 	bio->bi_end_io = bio_copy_kern_endio;
 
-	bio_set_map_data(bmd, bio, &iov, 1);
 	return bio;
-cleanup:
-	bio_for_each_segment(bvec, bio, i)
-		__free_page(bvec->bv_page);
-
-	bio_put(bio);
-out_bmd:
-	bio_free_map_data(bmd);
-
-	return ERR_PTR(ret);
 }
 
 /*
@@ -1230,9 +1256,9 @@ static void bio_pair_end_2(struct bio *bi, int err)
  * split a bio - only worry about a bio with a single page
  * in it's iovec
  */
-struct bio_pair *bio_split(struct bio *bi, mempool_t *pool, int first_sectors)
+struct bio_pair *bio_split(struct bio *bi, int first_sectors)
 {
-	struct bio_pair *bp = mempool_alloc(pool, GFP_NOIO);
+	struct bio_pair *bp = mempool_alloc(bio_split_pool, GFP_NOIO);
 
 	if (!bp)
 		return bp;
@@ -1266,7 +1292,7 @@ struct bio_pair *bio_split(struct bio *bi, mempool_t *pool, int first_sectors)
 	bp->bio2.bi_end_io = bio_pair_end_2;
 
 	bp->bio1.bi_private = bi;
-	bp->bio2.bi_private = pool;
+	bp->bio2.bi_private = bio_split_pool;
 
 	if (bio_integrity(bi))
 		bio_integrity_split(bi, bp, first_sectors);
@@ -1274,6 +1300,42 @@ struct bio_pair *bio_split(struct bio *bi, mempool_t *pool, int first_sectors)
 	return bp;
 }
 
+/**
+ *      bio_sector_offset - Find hardware sector offset in bio
+ *      @bio:           bio to inspect
+ *      @index:         bio_vec index
+ *      @offset:        offset in bv_page
+ *
+ *      Return the number of hardware sectors between beginning of bio
+ *      and an end point indicated by a bio_vec index and an offset
+ *      within that vector's page.
+ */
+sector_t bio_sector_offset(struct bio *bio, unsigned short index,
+			   unsigned int offset)
+{
+	unsigned int sector_sz = queue_hardsect_size(bio->bi_bdev->bd_disk->queue);
+	struct bio_vec *bv;
+	sector_t sectors;
+	int i;
+
+	sectors = 0;
+
+	if (index >= bio->bi_idx)
+		index = bio->bi_vcnt - 1;
+
+	__bio_for_each_segment(bv, bio, i, 0) {
+		if (i == index) {
+			if (offset > bv->bv_offset)
+				sectors += (offset - bv->bv_offset) / sector_sz;
+			break;
+		}
+
+		sectors += bv->bv_len / sector_sz;
+	}
+
+	return sectors;
+}
+EXPORT_SYMBOL(bio_sector_offset);
 
 /*
  * create memory pools for biovec's in a bio_set.
@@ -1376,6 +1438,7 @@ static int __init init_bio(void)
 subsys_initcall(init_bio);
 
 EXPORT_SYMBOL(bio_alloc);
+EXPORT_SYMBOL(bio_kmalloc);
 EXPORT_SYMBOL(bio_put);
 EXPORT_SYMBOL(bio_free);
 EXPORT_SYMBOL(bio_endio);
@@ -1383,7 +1446,6 @@ EXPORT_SYMBOL(bio_init);
 EXPORT_SYMBOL(__bio_clone);
 EXPORT_SYMBOL(bio_clone);
 EXPORT_SYMBOL(bio_phys_segments);
-EXPORT_SYMBOL(bio_hw_segments);
 EXPORT_SYMBOL(bio_add_page);
 EXPORT_SYMBOL(bio_add_pc_page);
 EXPORT_SYMBOL(bio_get_nr_vecs);
@@ -1393,7 +1455,6 @@ EXPORT_SYMBOL(bio_map_kern);
 EXPORT_SYMBOL(bio_copy_kern);
 EXPORT_SYMBOL(bio_pair_release);
 EXPORT_SYMBOL(bio_split);
-EXPORT_SYMBOL(bio_split_pool);
 EXPORT_SYMBOL(bio_copy_user);
 EXPORT_SYMBOL(bio_uncopy_user);
 EXPORT_SYMBOL(bioset_create);
diff --git a/fs/block_dev.c b/fs/block_dev.c
index aff54219e04..d84f0469a01 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -540,22 +540,6 @@ EXPORT_SYMBOL(bd_release);
  *           /sys/block/sda/holders/dm-0 --> /sys/block/dm-0
  */
 
-static struct kobject *bdev_get_kobj(struct block_device *bdev)
-{
-	if (bdev->bd_contains != bdev)
-		return kobject_get(&bdev->bd_part->dev.kobj);
-	else
-		return kobject_get(&bdev->bd_disk->dev.kobj);
-}
-
-static struct kobject *bdev_get_holder(struct block_device *bdev)
-{
-	if (bdev->bd_contains != bdev)
-		return kobject_get(bdev->bd_part->holder_dir);
-	else
-		return kobject_get(bdev->bd_disk->holder_dir);
-}
-
 static int add_symlink(struct kobject *from, struct kobject *to)
 {
 	if (!from || !to)
@@ -604,11 +588,11 @@ static int bd_holder_grab_dirs(struct block_device *bdev,
 	if (!bo->hdev)
 		goto fail_put_sdir;
 
-	bo->sdev = bdev_get_kobj(bdev);
+	bo->sdev = kobject_get(&part_to_dev(bdev->bd_part)->kobj);
 	if (!bo->sdev)
 		goto fail_put_hdev;
 
-	bo->hdir = bdev_get_holder(bdev);
+	bo->hdir = kobject_get(bdev->bd_part->holder_dir);
 	if (!bo->hdir)
 		goto fail_put_sdev;
 
@@ -868,6 +852,87 @@ struct block_device *open_by_devnum(dev_t dev, unsigned mode)
 
 EXPORT_SYMBOL(open_by_devnum);
 
+/**
+ * flush_disk - invalidates all buffer-cache entries on a disk
+ *
+ * @bdev:      struct block device to be flushed
+ *
+ * Invalidates all buffer-cache entries on a disk. It should be called
+ * when a disk has been changed -- either by a media change or online
+ * resize.
+ */
+static void flush_disk(struct block_device *bdev)
+{
+	if (__invalidate_device(bdev)) {
+		char name[BDEVNAME_SIZE] = "";
+
+		if (bdev->bd_disk)
+			disk_name(bdev->bd_disk, 0, name);
+		printk(KERN_WARNING "VFS: busy inodes on changed media or "
+		       "resized disk %s\n", name);
+	}
+
+	if (!bdev->bd_disk)
+		return;
+	if (disk_partitionable(bdev->bd_disk))
+		bdev->bd_invalidated = 1;
+}
+
+/**
+ * check_disk_size_change - checks for disk size change and adjusts bdev size.
+ * @disk: struct gendisk to check
+ * @bdev: struct bdev to adjust.
+ *
+ * This routine checks to see if the bdev size does not match the disk size
+ * and adjusts it if it differs.
+ */
+void check_disk_size_change(struct gendisk *disk, struct block_device *bdev)
+{
+	loff_t disk_size, bdev_size;
+
+	disk_size = (loff_t)get_capacity(disk) << 9;
+	bdev_size = i_size_read(bdev->bd_inode);
+	if (disk_size != bdev_size) {
+		char name[BDEVNAME_SIZE];
+
+		disk_name(disk, 0, name);
+		printk(KERN_INFO
+		       "%s: detected capacity change from %lld to %lld\n",
+		       name, bdev_size, disk_size);
+		i_size_write(bdev->bd_inode, disk_size);
+		flush_disk(bdev);
+	}
+}
+EXPORT_SYMBOL(check_disk_size_change);
+
+/**
+ * revalidate_disk - wrapper for lower-level driver's revalidate_disk call-back
+ * @disk: struct gendisk to be revalidated
+ *
+ * This routine is a wrapper for lower-level driver's revalidate_disk
+ * call-backs.  It is used to do common pre and post operations needed
+ * for all revalidate_disk operations.
+ */
+int revalidate_disk(struct gendisk *disk)
+{
+	struct block_device *bdev;
+	int ret = 0;
+
+	if (disk->fops->revalidate_disk)
+		ret = disk->fops->revalidate_disk(disk);
+
+	bdev = bdget_disk(disk, 0);
+	if (!bdev)
+		return ret;
+
+	mutex_lock(&bdev->bd_mutex);
+	check_disk_size_change(disk, bdev);
+	mutex_unlock(&bdev->bd_mutex);
+	bdput(bdev);
+	return ret;
+}
+EXPORT_SYMBOL(revalidate_disk);
+
 /*
  * This routine checks whether a removable media has been changed,
  * and invalidates all buffer-cache-entries in that case. This
@@ -887,13 +952,9 @@ int check_disk_change(struct block_device *bdev)
 	if (!bdops->media_changed(bdev->bd_disk))
 		return 0;
 
-	if (__invalidate_device(bdev))
-		printk("VFS: busy inodes on changed media.\n");
-
+	flush_disk(bdev);
 	if (bdops->revalidate_disk)
 		bdops->revalidate_disk(bdev->bd_disk);
-	if (bdev->bd_disk->minors > 1)
-		bdev->bd_invalidated = 1;
 	return 1;
 }
 
@@ -927,10 +988,10 @@ static int __blkdev_put(struct block_device *bdev, int for_part);
 
 static int do_open(struct block_device *bdev, struct file *file, int for_part)
 {
-	struct module *owner = NULL;
 	struct gendisk *disk;
+	struct hd_struct *part = NULL;
 	int ret;
-	int part;
+	int partno;
 	int perm = 0;
 
 	if (file->f_mode & FMODE_READ)
@@ -948,25 +1009,27 @@ static int do_open(struct block_device *bdev, struct file *file, int for_part)
 
 	ret = -ENXIO;
 	file->f_mapping = bdev->bd_inode->i_mapping;
+
 	lock_kernel();
-	disk = get_gendisk(bdev->bd_dev, &part);
-	if (!disk) {
-		unlock_kernel();
-		bdput(bdev);
-		return ret;
-	}
-	owner = disk->fops->owner;
+
+	disk = get_gendisk(bdev->bd_dev, &partno);
+	if (!disk)
+		goto out_unlock_kernel;
+	part = disk_get_part(disk, partno);
+	if (!part)
+		goto out_unlock_kernel;
 
 	mutex_lock_nested(&bdev->bd_mutex, for_part);
 	if (!bdev->bd_openers) {
 		bdev->bd_disk = disk;
+		bdev->bd_part = part;
 		bdev->bd_contains = bdev;
-		if (!part) {
+		if (!partno) {
 			struct backing_dev_info *bdi;
 			if (disk->fops->open) {
 				ret = disk->fops->open(bdev->bd_inode, file);
 				if (ret)
-					goto out_first;
+					goto out_clear;
 			}
 			if (!bdev->bd_openers) {
 				bd_set_size(bdev,(loff_t)get_capacity(disk)<<9);
@@ -978,36 +1041,36 @@ static int do_open(struct block_device *bdev, struct file *file, int for_part)
 			if (bdev->bd_invalidated)
 				rescan_partitions(disk, bdev);
 		} else {
-			struct hd_struct *p;
 			struct block_device *whole;
 			whole = bdget_disk(disk, 0);
 			ret = -ENOMEM;
 			if (!whole)
-				goto out_first;
+				goto out_clear;
 			BUG_ON(for_part);
 			ret = __blkdev_get(whole, file->f_mode, file->f_flags, 1);
 			if (ret)
-				goto out_first;
+				goto out_clear;
 			bdev->bd_contains = whole;
-			p = disk->part[part - 1];
 			bdev->bd_inode->i_data.backing_dev_info =
 			   whole->bd_inode->i_data.backing_dev_info;
-			if (!(disk->flags & GENHD_FL_UP) || !p || !p->nr_sects) {
+			if (!(disk->flags & GENHD_FL_UP) ||
+			    !part || !part->nr_sects) {
 				ret = -ENXIO;
-				goto out_first;
+				goto out_clear;
 			}
-			kobject_get(&p->dev.kobj);
-			bdev->bd_part = p;
-			bd_set_size(bdev, (loff_t) p->nr_sects << 9);
+			bd_set_size(bdev, (loff_t)part->nr_sects << 9);
 		}
 	} else {
+		disk_put_part(part);
 		put_disk(disk);
-		module_put(owner);
+		module_put(disk->fops->owner);
+		part = NULL;
+		disk = NULL;
 		if (bdev->bd_contains == bdev) {
 			if (bdev->bd_disk->fops->open) {
 				ret = bdev->bd_disk->fops->open(bdev->bd_inode, file);
 				if (ret)
-					goto out;
+					goto out_unlock_bdev;
 			}
 			if (bdev->bd_invalidated)
 				rescan_partitions(bdev->bd_disk, bdev);
@@ -1020,19 +1083,24 @@ static int do_open(struct block_device *bdev, struct file *file, int for_part)
 	unlock_kernel();
 	return 0;
 
-out_first:
+ out_clear:
 	bdev->bd_disk = NULL;
+	bdev->bd_part = NULL;
 	bdev->bd_inode->i_data.backing_dev_info = &default_backing_dev_info;
 	if (bdev != bdev->bd_contains)
 		__blkdev_put(bdev->bd_contains, 1);
 	bdev->bd_contains = NULL;
-	put_disk(disk);
-	module_put(owner);
-out:
+ out_unlock_bdev:
 	mutex_unlock(&bdev->bd_mutex);
+ out_unlock_kernel:
 	unlock_kernel();
-	if (ret)
-		bdput(bdev);
+
+	disk_put_part(part);
+	if (disk)
+		module_put(disk->fops->owner);
+	put_disk(disk);
+	bdput(bdev);
+
 	return ret;
 }
 
@@ -1117,11 +1185,8 @@ static int __blkdev_put(struct block_device *bdev, int for_part)
 
 		put_disk(disk);
 		module_put(owner);
-
-		if (bdev->bd_contains != bdev) {
-			kobject_put(&bdev->bd_part->dev.kobj);
-			bdev->bd_part = NULL;
-		}
+		disk_put_part(bdev->bd_part);
+		bdev->bd_part = NULL;
 		bdev->bd_disk = NULL;
 		bdev->bd_inode->i_data.backing_dev_info = &default_backing_dev_info;
 		if (bdev != bdev->bd_contains)
@@ -1197,10 +1262,9 @@ EXPORT_SYMBOL(ioctl_by_bdev);
 
 /**
  * lookup_bdev  - lookup a struct block_device by name
+ * @pathname:	special file representing the block device
  *
- * @path:	special file representing the block device
- *
- * Get a reference to the blockdevice at @path in the current
+ * Get a reference to the blockdevice at @pathname in the current
  * namespace if possible and return it.  Return ERR_PTR(error)
  * otherwise.
  */
diff --git a/fs/fat/fatent.c b/fs/fat/fatent.c
index 302e95c4af7..fb98b3d847e 100644
--- a/fs/fat/fatent.c
+++ b/fs/fat/fatent.c
@@ -6,6 +6,7 @@
 #include <linux/module.h>
 #include <linux/fs.h>
 #include <linux/msdos_fs.h>
+#include <linux/blkdev.h>
 
 struct fatent_operations {
 	void (*ent_blocknr)(struct super_block *, int, int *, sector_t *);
@@ -535,6 +536,7 @@ int fat_free_clusters(struct inode *inode, int cluster)
 	struct fat_entry fatent;
 	struct buffer_head *bhs[MAX_BUF_PER_PAGE];
 	int i, err, nr_bhs;
+	int first_cl = cluster;
 
 	nr_bhs = 0;
 	fatent_init(&fatent);
@@ -551,6 +553,18 @@ int fat_free_clusters(struct inode *inode, int cluster)
 			goto error;
 		}
 
+		/* 
+		 * Issue discard for the sectors we no longer care about,
+		 * batching contiguous clusters into one request
+		 */
+		if (cluster != fatent.entry + 1) {
+			int nr_clus = fatent.entry - first_cl + 1;
+
+			sb_issue_discard(sb, fat_clus_to_blknr(sbi, first_cl),
+					 nr_clus * sbi->sec_per_clus);
+			first_cl = cluster;
+		}
+
 		ops->ent_put(&fatent, FAT_ENT_FREE);
 		if (sbi->free_clusters != -1) {
 			sbi->free_clusters++;
diff --git a/fs/partitions/check.c b/fs/partitions/check.c
index ecc3330972e..7408227c49c 100644
--- a/fs/partitions/check.c
+++ b/fs/partitions/check.c
@@ -120,22 +120,21 @@ static int (*check_part[])(struct parsed_partitions *, struct block_device *) =
  * a pointer to that same buffer (for convenience).
  */
 
-char *disk_name(struct gendisk *hd, int part, char *buf)
+char *disk_name(struct gendisk *hd, int partno, char *buf)
 {
-	if (!part)
+	if (!partno)
 		snprintf(buf, BDEVNAME_SIZE, "%s", hd->disk_name);
 	else if (isdigit(hd->disk_name[strlen(hd->disk_name)-1]))
-		snprintf(buf, BDEVNAME_SIZE, "%sp%d", hd->disk_name, part);
+		snprintf(buf, BDEVNAME_SIZE, "%sp%d", hd->disk_name, partno);
 	else
-		snprintf(buf, BDEVNAME_SIZE, "%s%d", hd->disk_name, part);
+		snprintf(buf, BDEVNAME_SIZE, "%s%d", hd->disk_name, partno);
 
 	return buf;
 }
 
 const char *bdevname(struct block_device *bdev, char *buf)
 {
-	int part = MINOR(bdev->bd_dev) - bdev->bd_disk->first_minor;
-	return disk_name(bdev->bd_disk, part, buf);
+	return disk_name(bdev->bd_disk, bdev->bd_part->partno, buf);
 }
 
 EXPORT_SYMBOL(bdevname);
@@ -169,7 +168,7 @@ check_partition(struct gendisk *hd, struct block_device *bdev)
 	if (isdigit(state->name[strlen(state->name)-1]))
 		sprintf(state->name, "p");
 
-	state->limit = hd->minors;
+	state->limit = disk_max_parts(hd);
 	i = res = err = 0;
 	while (!res && check_part[i]) {
 		memset(&state->parts, 0, sizeof(state->parts));
@@ -204,21 +203,22 @@ static ssize_t part_start_show(struct device *dev,
 	return sprintf(buf, "%llu\n",(unsigned long long)p->start_sect);
 }
 
-static ssize_t part_size_show(struct device *dev,
-			      struct device_attribute *attr, char *buf)
+ssize_t part_size_show(struct device *dev,
+		       struct device_attribute *attr, char *buf)
 {
 	struct hd_struct *p = dev_to_part(dev);
 	return sprintf(buf, "%llu\n",(unsigned long long)p->nr_sects);
 }
 
-static ssize_t part_stat_show(struct device *dev,
-			      struct device_attribute *attr, char *buf)
+ssize_t part_stat_show(struct device *dev,
+		       struct device_attribute *attr, char *buf)
 {
 	struct hd_struct *p = dev_to_part(dev);
+	int cpu;
 
-	preempt_disable();
-	part_round_stats(p);
-	preempt_enable();
+	cpu = part_stat_lock();
+	part_round_stats(cpu, p);
+	part_stat_unlock();
 	return sprintf(buf,
 		"%8lu %8lu %8llu %8u "
 		"%8lu %8lu %8llu %8u "
@@ -238,17 +238,17 @@ static ssize_t part_stat_show(struct device *dev,
 }
 
 #ifdef CONFIG_FAIL_MAKE_REQUEST
-static ssize_t part_fail_show(struct device *dev,
-			      struct device_attribute *attr, char *buf)
+ssize_t part_fail_show(struct device *dev,
+		       struct device_attribute *attr, char *buf)
 {
 	struct hd_struct *p = dev_to_part(dev);
 
 	return sprintf(buf, "%d\n", p->make_it_fail);
 }
 
-static ssize_t part_fail_store(struct device *dev,
-			       struct device_attribute *attr,
-			       const char *buf, size_t count)
+ssize_t part_fail_store(struct device *dev,
+			struct device_attribute *attr,
+			const char *buf, size_t count)
 {
 	struct hd_struct *p = dev_to_part(dev);
 	int i;
@@ -300,40 +300,34 @@ struct device_type part_type = {
 	.release	= part_release,
 };
 
-static inline void partition_sysfs_add_subdir(struct hd_struct *p)
-{
-	struct kobject *k;
-
-	k = kobject_get(&p->dev.kobj);
-	p->holder_dir = kobject_create_and_add("holders", k);
-	kobject_put(k);
-}
-
-static inline void disk_sysfs_add_subdirs(struct gendisk *disk)
+static void delete_partition_rcu_cb(struct rcu_head *head)
 {
-	struct kobject *k;
+	struct hd_struct *part = container_of(head, struct hd_struct, rcu_head);
 
-	k = kobject_get(&disk->dev.kobj);
-	disk->holder_dir = kobject_create_and_add("holders", k);
-	disk->slave_dir = kobject_create_and_add("slaves", k);
-	kobject_put(k);
+	part->start_sect = 0;
+	part->nr_sects = 0;
+	part_stat_set_all(part, 0);
+	put_device(part_to_dev(part));
 }
 
-void delete_partition(struct gendisk *disk, int part)
+void delete_partition(struct gendisk *disk, int partno)
 {
-	struct hd_struct *p = disk->part[part-1];
+	struct disk_part_tbl *ptbl = disk->part_tbl;
+	struct hd_struct *part;
 
-	if (!p)
+	if (partno >= ptbl->len)
 		return;
-	if (!p->nr_sects)
+
+	part = ptbl->part[partno];
+	if (!part)
 		return;
-	disk->part[part-1] = NULL;
-	p->start_sect = 0;
-	p->nr_sects = 0;
-	part_stat_set_all(p, 0);
-	kobject_put(p->holder_dir);
-	device_del(&p->dev);
-	put_device(&p->dev);
+
+	blk_free_devt(part_devt(part));
+	rcu_assign_pointer(ptbl->part[partno], NULL);
+	kobject_put(part->holder_dir);
+	device_del(part_to_dev(part));
+
+	call_rcu(&part->rcu_head, delete_partition_rcu_cb);
 }
 
 static ssize_t whole_disk_show(struct device *dev,
@@ -344,102 +338,132 @@ static ssize_t whole_disk_show(struct device *dev,
 static DEVICE_ATTR(whole_disk, S_IRUSR | S_IRGRP | S_IROTH,
 		   whole_disk_show, NULL);
 
-int add_partition(struct gendisk *disk, int part, sector_t start, sector_t len, int flags)
+int add_partition(struct gendisk *disk, int partno,
+		  sector_t start, sector_t len, int flags)
 {
 	struct hd_struct *p;
+	dev_t devt = MKDEV(0, 0);
+	struct device *ddev = disk_to_dev(disk);
+	struct device *pdev;
+	struct disk_part_tbl *ptbl;
+	const char *dname;
 	int err;
 
+	err = disk_expand_part_tbl(disk, partno);
+	if (err)
+		return err;
+	ptbl = disk->part_tbl;
+
+	if (ptbl->part[partno])
+		return -EBUSY;
+
 	p = kzalloc(sizeof(*p), GFP_KERNEL);
 	if (!p)
 		return -ENOMEM;
 
 	if (!init_part_stats(p)) {
 		err = -ENOMEM;
-		goto out0;
+		goto out_free;
 	}
+	pdev = part_to_dev(p);
+
 	p->start_sect = start;
 	p->nr_sects = len;
-	p->partno = part;
-	p->policy = disk->policy;
+	p->partno = partno;
+	p->policy = get_disk_ro(disk);
 
-	if (isdigit(disk->dev.bus_id[strlen(disk->dev.bus_id)-1]))
-		snprintf(p->dev.bus_id, BUS_ID_SIZE,
-		"%sp%d", disk->dev.bus_id, part);
+	dname = dev_name(ddev);
+	if (isdigit(dname[strlen(dname) - 1]))
+		snprintf(pdev->bus_id, BUS_ID_SIZE, "%sp%d", dname, partno);
 	else
-		snprintf(p->dev.bus_id, BUS_ID_SIZE,
-			 "%s%d", disk->dev.bus_id, part);
+		snprintf(pdev->bus_id, BUS_ID_SIZE, "%s%d", dname, partno);
 
-	device_initialize(&p->dev);
-	p->dev.devt = MKDEV(disk->major, disk->first_minor + part);
-	p->dev.class = &block_class;
-	p->dev.type = &part_type;
-	p->dev.parent = &disk->dev;
-	disk->part[part-1] = p;
+	device_initialize(pdev);
+	pdev->class = &block_class;
+	pdev->type = &part_type;
+	pdev->parent = ddev;
+
+	err = blk_alloc_devt(p, &devt);
+	if (err)
+		goto out_free;
+	pdev->devt = devt;
 
 	/* delay uevent until 'holders' subdir is created */
-	p->dev.uevent_suppress = 1;
-	err = device_add(&p->dev);
+	pdev->uevent_suppress = 1;
+	err = device_add(pdev);
 	if (err)
-		goto out1;
-	partition_sysfs_add_subdir(p);
-	p->dev.uevent_suppress = 0;
+		goto out_put;
+
+	err = -ENOMEM;
+	p->holder_dir = kobject_create_and_add("holders", &pdev->kobj);
+	if (!p->holder_dir)
+		goto out_del;
+
+	pdev->uevent_suppress = 0;
 	if (flags & ADDPART_FLAG_WHOLEDISK) {
-		err = device_create_file(&p->dev, &dev_attr_whole_disk);
+		err = device_create_file(pdev, &dev_attr_whole_disk);
 		if (err)
-			goto out2;
+			goto out_del;
 	}
 
+	/* everything is up and running, commence */
+	INIT_RCU_HEAD(&p->rcu_head);
+	rcu_assign_pointer(ptbl->part[partno], p);
+
 	/* suppress uevent if the disk supresses it */
-	if (!disk->dev.uevent_suppress)
-		kobject_uevent(&p->dev.kobj, KOBJ_ADD);
+	if (!ddev->uevent_suppress)
+		kobject_uevent(&pdev->kobj, KOBJ_ADD);
 
 	return 0;
 
-out2:
-	device_del(&p->dev);
-out1:
-	put_device(&p->dev);
-	free_part_stats(p);
-out0:
+out_free:
 	kfree(p);
 	return err;
+out_del:
+	kobject_put(p->holder_dir);
+	device_del(pdev);
+out_put:
+	put_device(pdev);
+	blk_free_devt(devt);
+	return err;
 }
 
 /* Not exported, helper to add_disk(). */
 void register_disk(struct gendisk *disk)
 {
+	struct device *ddev = disk_to_dev(disk);
 	struct block_device *bdev;
+	struct disk_part_iter piter;
+	struct hd_struct *part;
 	char *s;
-	int i;
-	struct hd_struct *p;
 	int err;
 
-	disk->dev.parent = disk->driverfs_dev;
-	disk->dev.devt = MKDEV(disk->major, disk->first_minor);
+	ddev->parent = disk->driverfs_dev;
 
-	strlcpy(disk->dev.bus_id, disk->disk_name, BUS_ID_SIZE);
+	strlcpy(ddev->bus_id, disk->disk_name, BUS_ID_SIZE);
 	/* ewww... some of these buggers have / in the name... */
-	s = strchr(disk->dev.bus_id, '/');
+	s = strchr(ddev->bus_id, '/');
 	if (s)
 		*s = '!';
 
 	/* delay uevents, until we scanned partition table */
-	disk->dev.uevent_suppress = 1;
+	ddev->uevent_suppress = 1;
 
-	if (device_add(&disk->dev))
+	if (device_add(ddev))
 		return;
 #ifndef CONFIG_SYSFS_DEPRECATED
-	err = sysfs_create_link(block_depr, &disk->dev.kobj,
-				kobject_name(&disk->dev.kobj));
+	err = sysfs_create_link(block_depr, &ddev->kobj,
+				kobject_name(&ddev->kobj));
 	if (err) {
-		device_del(&disk->dev);
+		device_del(ddev);
 		return;
 	}
 #endif
-	disk_sysfs_add_subdirs(disk);
+	disk->part0.holder_dir = kobject_create_and_add("holders", &ddev->kobj);
+	disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj);
 
 	/* No minors to use for partitions */
-	if (disk->minors == 1)
+	if (!disk_partitionable(disk))
 		goto exit;
 
 	/* No such device (e.g., media were just removed) */
@@ -458,41 +482,57 @@ void register_disk(struct gendisk *disk)
 
 exit:
 	/* announce disk after possible partitions are created */
-	disk->dev.uevent_suppress = 0;
-	kobject_uevent(&disk->dev.kobj, KOBJ_ADD);
+	ddev->uevent_suppress = 0;
+	kobject_uevent(&ddev->kobj, KOBJ_ADD);
 
 	/* announce possible partitions */
-	for (i = 1; i < disk->minors; i++) {
-		p = disk->part[i-1];
-		if (!p || !p->nr_sects)
-			continue;
-		kobject_uevent(&p->dev.kobj, KOBJ_ADD);
-	}
+	disk_part_iter_init(&piter, disk, 0);
+	while ((part = disk_part_iter_next(&piter)))
+		kobject_uevent(&part_to_dev(part)->kobj, KOBJ_ADD);
+	disk_part_iter_exit(&piter);
 }
 
 int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
 {
+	struct disk_part_iter piter;
+	struct hd_struct *part;
 	struct parsed_partitions *state;
-	int p, res;
+	int p, highest, res;
 
 	if (bdev->bd_part_count)
 		return -EBUSY;
 	res = invalidate_partition(disk, 0);
 	if (res)
 		return res;
-	bdev->bd_invalidated = 0;
-	for (p = 1; p < disk->minors; p++)
-		delete_partition(disk, p);
+
+	disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
+	while ((part = disk_part_iter_next(&piter)))
+		delete_partition(disk, part->partno);
+	disk_part_iter_exit(&piter);
+
 	if (disk->fops->revalidate_disk)
 		disk->fops->revalidate_disk(disk);
+	check_disk_size_change(disk, bdev);
+	bdev->bd_invalidated = 0;
 	if (!get_capacity(disk) || !(state = check_partition(disk, bdev)))
 		return 0;
 	if (IS_ERR(state))	/* I/O error reading the partition table */
 		return -EIO;
 
 	/* tell userspace that the media / partition table may have changed */
-	kobject_uevent(&disk->dev.kobj, KOBJ_CHANGE);
+	kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
 
+	/* Detect the highest partition number and preallocate
+	 * disk->part_tbl.  This is an optimization and not strictly
+	 * necessary.
+	 */
+	for (p = 1, highest = 0; p < state->limit; p++)
+		if (state->parts[p].size)
+			highest = p;
+
+	disk_expand_part_tbl(disk, highest);
+
+	/* add partitions */
 	for (p = 1; p < state->limit; p++) {
 		sector_t size = state->parts[p].size;
 		sector_t from = state->parts[p].from;
@@ -541,25 +581,31 @@ EXPORT_SYMBOL(read_dev_sector);
 
 void del_gendisk(struct gendisk *disk)
 {
-	int p;
+	struct disk_part_iter piter;
+	struct hd_struct *part;
 
 	/* invalidate stuff */
-	for (p = disk->minors - 1; p > 0; p--) {
-		invalidate_partition(disk, p);
-		delete_partition(disk, p);
+	disk_part_iter_init(&piter, disk,
+			     DISK_PITER_INCL_EMPTY | DISK_PITER_REVERSE);
+	while ((part = disk_part_iter_next(&piter))) {
+		invalidate_partition(disk, part->partno);
+		delete_partition(disk, part->partno);
 	}
+	disk_part_iter_exit(&piter);
+
 	invalidate_partition(disk, 0);
-	disk->capacity = 0;
+	blk_free_devt(disk_to_dev(disk)->devt);
+	set_capacity(disk, 0);
 	disk->flags &= ~GENHD_FL_UP;
 	unlink_gendisk(disk);
-	disk_stat_set_all(disk, 0);
-	disk->stamp = 0;
+	part_stat_set_all(&disk->part0, 0);
+	disk->part0.stamp = 0;
 
-	kobject_put(disk->holder_dir);
+	kobject_put(disk->part0.holder_dir);
 	kobject_put(disk->slave_dir);
 	disk->driverfs_dev = NULL;
 #ifndef CONFIG_SYSFS_DEPRECATED
-	sysfs_remove_link(block_depr, disk->dev.bus_id);
+	sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk)));
 #endif
-	device_del(&disk->dev);
+	device_del(disk_to_dev(disk));
 }
diff --git a/fs/partitions/check.h b/fs/partitions/check.h
index 17ae8ecd9e8..98dbe1a8452 100644
--- a/fs/partitions/check.h
+++ b/fs/partitions/check.h
@@ -5,15 +5,13 @@
  * add_gd_partition adds a partitions details to the devices partition
  * description.
  */
-enum { MAX_PART = 256 };
-
 struct parsed_partitions {
 	char name[BDEVNAME_SIZE];
 	struct {
 		sector_t from;
 		sector_t size;
 		int flags;
-	} parts[MAX_PART];
+	} parts[DISK_MAX_PARTS];
 	int next;
 	int limit;
 };
diff --git a/include/linux/Kbuild b/include/linux/Kbuild
index b68ec09399b..31474e89c59 100644
--- a/include/linux/Kbuild
+++ b/include/linux/Kbuild
@@ -180,6 +180,7 @@ unifdef-y += audit.h
 unifdef-y += auto_fs.h
 unifdef-y += auxvec.h
 unifdef-y += binfmts.h
+unifdef-y += blktrace_api.h
 unifdef-y += capability.h
 unifdef-y += capi.h
 unifdef-y += cciss_ioctl.h
diff --git a/include/linux/ata.h b/include/linux/ata.h
index a26ebd25bac..be00973d1a8 100644
--- a/include/linux/ata.h
+++ b/include/linux/ata.h
@@ -88,6 +88,7 @@ enum {
 	ATA_ID_DLF		= 128,
 	ATA_ID_CSFO		= 129,
 	ATA_ID_CFA_POWER	= 160,
+	ATA_ID_ROT_SPEED	= 217,
 	ATA_ID_PIO4		= (1 << 1),
 
 	ATA_ID_SERNO_LEN	= 20,
@@ -700,6 +701,11 @@ static inline int ata_id_is_cfa(const u16 *id)
 	return 0;
 }
 
+static inline int ata_id_is_ssd(const u16 *id)
+{
+	return id[ATA_ID_ROT_SPEED] == 0x01;
+}
+
 static inline int ata_drive_40wire(const u16 *dev_id)
 {
 	if (ata_id_is_sata(dev_id))
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 0933a14e641..ff5b4cf9e2d 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -26,21 +26,8 @@
 
 #ifdef CONFIG_BLOCK
 
-/* Platforms may set this to teach the BIO layer about IOMMU hardware. */
 #include <asm/io.h>
 
-#if defined(BIO_VMERGE_MAX_SIZE) && defined(BIO_VMERGE_BOUNDARY)
-#define BIOVEC_VIRT_START_SIZE(x) (bvec_to_phys(x) & (BIO_VMERGE_BOUNDARY - 1))
-#define BIOVEC_VIRT_OVERSIZE(x)	((x) > BIO_VMERGE_MAX_SIZE)
-#else
-#define BIOVEC_VIRT_START_SIZE(x)	0
-#define BIOVEC_VIRT_OVERSIZE(x)		0
-#endif
-
-#ifndef BIO_VMERGE_BOUNDARY
-#define BIO_VMERGE_BOUNDARY	0
-#endif
-
 #define BIO_DEBUG
 
 #ifdef BIO_DEBUG
@@ -88,25 +75,14 @@ struct bio {
 	/* Number of segments in this BIO after
 	 * physical address coalescing is performed.
 	 */
-	unsigned short		bi_phys_segments;
-
-	/* Number of segments after physical and DMA remapping
-	 * hardware coalescing is performed.
-	 */
-	unsigned short		bi_hw_segments;
+	unsigned int		bi_phys_segments;
 
 	unsigned int		bi_size;	/* residual I/O count */
 
-	/*
-	 * To keep track of the max hw size, we account for the
-	 * sizes of the first and last virtually mergeable segments
-	 * in this bio
-	 */
-	unsigned int		bi_hw_front_size;
-	unsigned int		bi_hw_back_size;
-
 	unsigned int		bi_max_vecs;	/* max bvl_vecs we can hold */
 
+	unsigned int		bi_comp_cpu;	/* completion CPU */
+
 	struct bio_vec		*bi_io_vec;	/* the actual vec list */
 
 	bio_end_io_t		*bi_end_io;
@@ -126,11 +102,14 @@ struct bio {
 #define BIO_UPTODATE	0	/* ok after I/O completion */
 #define BIO_RW_BLOCK	1	/* RW_AHEAD set, and read/write would block */
 #define BIO_EOF		2	/* out-out-bounds error */
-#define BIO_SEG_VALID	3	/* nr_hw_seg valid */
+#define BIO_SEG_VALID	3	/* bi_phys_segments valid */
 #define BIO_CLONED	4	/* doesn't own data */
 #define BIO_BOUNCED	5	/* bio is a bounce bio */
 #define BIO_USER_MAPPED 6	/* contains user pages */
 #define BIO_EOPNOTSUPP	7	/* not supported */
+#define BIO_CPU_AFFINE	8	/* complete bio on same CPU as submitted */
+#define BIO_NULL_MAPPED 9	/* contains invalid user pages */
+#define BIO_FS_INTEGRITY 10	/* fs owns integrity data, not block layer */
 #define bio_flagged(bio, flag)	((bio)->bi_flags & (1 << (flag)))
 
 /*
@@ -144,18 +123,31 @@ struct bio {
 /*
  * bio bi_rw flags
  *
- * bit 0 -- read (not set) or write (set)
+ * bit 0 -- data direction
+ *	If not set, bio is a read from device. If set, it's a write to device.
  * bit 1 -- rw-ahead when set
  * bit 2 -- barrier
+ *	Insert a serialization point in the IO queue, forcing previously
+ *	submitted IO to be completed before this oen is issued.
  * bit 3 -- fail fast, don't want low level driver retries
  * bit 4 -- synchronous I/O hint: the block layer will unplug immediately
+ *	Note that this does NOT indicate that the IO itself is sync, just
+ *	that the block layer will not postpone issue of this IO by plugging.
+ * bit 5 -- metadata request
+ *	Used for tracing to differentiate metadata and data IO. May also
+ *	get some preferential treatment in the IO scheduler
+ * bit 6 -- discard sectors
+ *	Informs the lower level device that this range of sectors is no longer
+ *	used by the file system and may thus be freed by the device. Used
+ *	for flash based storage.
  */
-#define BIO_RW		0
-#define BIO_RW_AHEAD	1
+#define BIO_RW		0	/* Must match RW in req flags (blkdev.h) */
+#define BIO_RW_AHEAD	1	/* Must match FAILFAST in req flags */
 #define BIO_RW_BARRIER	2
 #define BIO_RW_FAILFAST	3
 #define BIO_RW_SYNC	4
 #define BIO_RW_META	5
+#define BIO_RW_DISCARD	6
 
 /*
  * upper 16 bits of bi_rw define the io priority of this bio
@@ -185,14 +177,15 @@ struct bio {
 #define bio_failfast(bio)	((bio)->bi_rw & (1 << BIO_RW_FAILFAST))
 #define bio_rw_ahead(bio)	((bio)->bi_rw & (1 << BIO_RW_AHEAD))
 #define bio_rw_meta(bio)	((bio)->bi_rw & (1 << BIO_RW_META))
-#define bio_empty_barrier(bio)	(bio_barrier(bio) && !(bio)->bi_size)
+#define bio_discard(bio)	((bio)->bi_rw & (1 << BIO_RW_DISCARD))
+#define bio_empty_barrier(bio)	(bio_barrier(bio) && !bio_has_data(bio) && !bio_discard(bio))
 
 static inline unsigned int bio_cur_sectors(struct bio *bio)
 {
 	if (bio->bi_vcnt)
 		return bio_iovec(bio)->bv_len >> 9;
-
-	return 0;
+	else /* dataless requests such as discard */
+		return bio->bi_size >> 9;
 }
 
 static inline void *bio_data(struct bio *bio)
@@ -236,8 +229,6 @@ static inline void *bio_data(struct bio *bio)
 	((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
 #endif
 
-#define BIOVEC_VIRT_MERGEABLE(vec1, vec2)	\
-	((((bvec_to_phys((vec1)) + (vec1)->bv_len) | bvec_to_phys((vec2))) & (BIO_VMERGE_BOUNDARY - 1)) == 0)
 #define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \
 	(((addr1) | (mask)) == (((addr2) - 1) | (mask)))
 #define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
@@ -319,15 +310,14 @@ struct bio_pair {
 	atomic_t			cnt;
 	int				error;
 };
-extern struct bio_pair *bio_split(struct bio *bi, mempool_t *pool,
-				  int first_sectors);
-extern mempool_t *bio_split_pool;
+extern struct bio_pair *bio_split(struct bio *bi, int first_sectors);
 extern void bio_pair_release(struct bio_pair *dbio);
 
 extern struct bio_set *bioset_create(int, int);
 extern void bioset_free(struct bio_set *);
 
 extern struct bio *bio_alloc(gfp_t, int);
+extern struct bio *bio_kmalloc(gfp_t, int);
 extern struct bio *bio_alloc_bioset(gfp_t, int, struct bio_set *);
 extern void bio_put(struct bio *);
 extern void bio_free(struct bio *, struct bio_set *);
@@ -335,7 +325,6 @@ extern void bio_free(struct bio *, struct bio_set *);
 extern void bio_endio(struct bio *, int);
 struct request_queue;
 extern int bio_phys_segments(struct request_queue *, struct bio *);
-extern int bio_hw_segments(struct request_queue *, struct bio *);
 
 extern void __bio_clone(struct bio *, struct bio *);
 extern struct bio *bio_clone(struct bio *, gfp_t);
@@ -346,12 +335,14 @@ extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
 extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
 			   unsigned int, unsigned int);
 extern int bio_get_nr_vecs(struct block_device *);
+extern sector_t bio_sector_offset(struct bio *, unsigned short, unsigned int);
 extern struct bio *bio_map_user(struct request_queue *, struct block_device *,
-				unsigned long, unsigned int, int);
+				unsigned long, unsigned int, int, gfp_t);
 struct sg_iovec;
+struct rq_map_data;
 extern struct bio *bio_map_user_iov(struct request_queue *,
 				    struct block_device *,
-				    struct sg_iovec *, int, int);
+				    struct sg_iovec *, int, int, gfp_t);
 extern void bio_unmap_user(struct bio *);
 extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
 				gfp_t);
@@ -359,15 +350,25 @@ extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
 				 gfp_t, int);
 extern void bio_set_pages_dirty(struct bio *bio);
 extern void bio_check_pages_dirty(struct bio *bio);
-extern struct bio *bio_copy_user(struct request_queue *, unsigned long, unsigned int, int);
-extern struct bio *bio_copy_user_iov(struct request_queue *, struct sg_iovec *,
-				     int, int);
+extern struct bio *bio_copy_user(struct request_queue *, struct rq_map_data *,
+				 unsigned long, unsigned int, int, gfp_t);
+extern struct bio *bio_copy_user_iov(struct request_queue *,
+				     struct rq_map_data *, struct sg_iovec *,
+				     int, int, gfp_t);
 extern int bio_uncopy_user(struct bio *);
 void zero_fill_bio(struct bio *bio);
 extern struct bio_vec *bvec_alloc_bs(gfp_t, int, unsigned long *, struct bio_set *);
 extern unsigned int bvec_nr_vecs(unsigned short idx);
 
 /*
+ * Allow queuer to specify a completion CPU for this bio
+ */
+static inline void bio_set_completion_cpu(struct bio *bio, unsigned int cpu)
+{
+	bio->bi_comp_cpu = cpu;
+}
+
+/*
  * bio_set is used to allow other portions of the IO system to
  * allocate their own private memory pools for bio and iovec structures.
  * These memory pools in turn all allocate from the bio_slab
@@ -445,6 +446,14 @@ static inline char *__bio_kmap_irq(struct bio *bio, unsigned short idx,
 	__bio_kmap_irq((bio), (bio)->bi_idx, (flags))
 #define bio_kunmap_irq(buf,flags)	__bio_kunmap_irq(buf, flags)
 
+/*
+ * Check whether this bio carries any data or not. A NULL bio is allowed.
+ */
+static inline int bio_has_data(struct bio *bio)
+{
+	return bio && bio->bi_io_vec != NULL;
+}
+
 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 
 #define bip_vec_idx(bip, idx)	(&(bip->bip_vec[(idx)]))
@@ -458,14 +467,7 @@ static inline char *__bio_kmap_irq(struct bio *bio, unsigned short idx,
 #define bip_for_each_vec(bvl, bip, i)					\
 	__bip_for_each_vec(bvl, bip, i, (bip)->bip_idx)
 
-static inline int bio_integrity(struct bio *bio)
-{
-#if defined(CONFIG_BLK_DEV_INTEGRITY)
-	return bio->bi_integrity != NULL;
-#else
-	return 0;
-#endif
-}
+#define bio_integrity(bio) (bio->bi_integrity != NULL)
 
 extern struct bio_integrity_payload *bio_integrity_alloc_bioset(struct bio *, gfp_t, unsigned int, struct bio_set *);
 extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 53ea933cf60..a92d9e4ea96 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -16,7 +16,9 @@
 #include <linux/bio.h>
 #include <linux/module.h>
 #include <linux/stringify.h>
+#include <linux/gfp.h>
 #include <linux/bsg.h>
+#include <linux/smp.h>
 
 #include <asm/scatterlist.h>
 
@@ -54,7 +56,6 @@ enum rq_cmd_type_bits {
 	REQ_TYPE_PM_SUSPEND,		/* suspend request */
 	REQ_TYPE_PM_RESUME,		/* resume request */
 	REQ_TYPE_PM_SHUTDOWN,		/* shutdown request */
-	REQ_TYPE_FLUSH,			/* flush request */
 	REQ_TYPE_SPECIAL,		/* driver defined type */
 	REQ_TYPE_LINUX_BLOCK,		/* generic block layer message */
 	/*
@@ -76,19 +77,18 @@ enum rq_cmd_type_bits {
  *
  */
 enum {
-	/*
-	 * just examples for now
-	 */
 	REQ_LB_OP_EJECT	= 0x40,		/* eject request */
-	REQ_LB_OP_FLUSH = 0x41,		/* flush device */
+	REQ_LB_OP_FLUSH = 0x41,		/* flush request */
+	REQ_LB_OP_DISCARD = 0x42,	/* discard sectors */
 };
 
 /*
- * request type modified bits. first three bits match BIO_RW* bits, important
+ * request type modified bits. first two bits match BIO_RW* bits, important
  */
 enum rq_flag_bits {
 	__REQ_RW,		/* not set, read. set, write */
 	__REQ_FAILFAST,		/* no low level driver retries */
+	__REQ_DISCARD,		/* request to discard sectors */
 	__REQ_SORTED,		/* elevator knows about this request */
 	__REQ_SOFTBARRIER,	/* may not be passed by ioscheduler */
 	__REQ_HARDBARRIER,	/* may not be passed by drive either */
@@ -111,6 +111,7 @@ enum rq_flag_bits {
 };
 
 #define REQ_RW		(1 << __REQ_RW)
+#define REQ_DISCARD	(1 << __REQ_DISCARD)
 #define REQ_FAILFAST	(1 << __REQ_FAILFAST)
 #define REQ_SORTED	(1 << __REQ_SORTED)
 #define REQ_SOFTBARRIER	(1 << __REQ_SOFTBARRIER)
@@ -140,12 +141,14 @@ enum rq_flag_bits {
  */
 struct request {
 	struct list_head queuelist;
-	struct list_head donelist;
+	struct call_single_data csd;
+	int cpu;
 
 	struct request_queue *q;
 
 	unsigned int cmd_flags;
 	enum rq_cmd_type_bits cmd_type;
+	unsigned long atomic_flags;
 
 	/* Maintain bio traversal state for part by part I/O submission.
 	 * hard_* are block layer internals, no driver should touch them!
@@ -190,13 +193,6 @@ struct request {
 	 */
 	unsigned short nr_phys_segments;
 
-	/* Number of scatter-gather addr+len pairs after
-	 * physical and DMA remapping hardware coalescing is performed.
-	 * This is the number of scatter-gather entries the driver
-	 * will actually have to deal with after DMA mapping is done.
-	 */
-	unsigned short nr_hw_segments;
-
 	unsigned short ioprio;
 
 	void *special;
@@ -220,6 +216,8 @@ struct request {
 	void *data;
 	void *sense;
 
+	unsigned long deadline;
+	struct list_head timeout_list;
 	unsigned int timeout;
 	int retries;
 
@@ -233,6 +231,11 @@ struct request {
 	struct request *next_rq;
 };
 
+static inline unsigned short req_get_ioprio(struct request *req)
+{
+	return req->ioprio;
+}
+
 /*
  * State information carried for REQ_TYPE_PM_SUSPEND and REQ_TYPE_PM_RESUME
  * requests. Some step values could eventually be made generic.
@@ -252,6 +255,7 @@ typedef void (request_fn_proc) (struct request_queue *q);
 typedef int (make_request_fn) (struct request_queue *q, struct bio *bio);
 typedef int (prep_rq_fn) (struct request_queue *, struct request *);
 typedef void (unplug_fn) (struct request_queue *);
+typedef int (prepare_discard_fn) (struct request_queue *, struct request *);
 
 struct bio_vec;
 struct bvec_merge_data {
@@ -265,6 +269,15 @@ typedef int (merge_bvec_fn) (struct request_queue *, struct bvec_merge_data *,
 typedef void (prepare_flush_fn) (struct request_queue *, struct request *);
 typedef void (softirq_done_fn)(struct request *);
 typedef int (dma_drain_needed_fn)(struct request *);
+typedef int (lld_busy_fn) (struct request_queue *q);
+
+enum blk_eh_timer_return {
+	BLK_EH_NOT_HANDLED,
+	BLK_EH_HANDLED,
+	BLK_EH_RESET_TIMER,
+};
+
+typedef enum blk_eh_timer_return (rq_timed_out_fn)(struct request *);
 
 enum blk_queue_state {
 	Queue_down,
@@ -307,10 +320,13 @@ struct request_queue
 	make_request_fn		*make_request_fn;
 	prep_rq_fn		*prep_rq_fn;
 	unplug_fn		*unplug_fn;
+	prepare_discard_fn	*prepare_discard_fn;
 	merge_bvec_fn		*merge_bvec_fn;
 	prepare_flush_fn	*prepare_flush_fn;
 	softirq_done_fn		*softirq_done_fn;
+	rq_timed_out_fn		*rq_timed_out_fn;
 	dma_drain_needed_fn	*dma_drain_needed;
+	lld_busy_fn		*lld_busy_fn;
 
 	/*
 	 * Dispatch queue sorting
@@ -385,6 +401,10 @@ struct request_queue
 	unsigned int		nr_sorted;
 	unsigned int		in_flight;
 
+	unsigned int		rq_timeout;
+	struct timer_list	timeout;
+	struct list_head	timeout_list;
+
 	/*
 	 * sg stuff
 	 */
@@ -421,6 +441,10 @@ struct request_queue
 #define QUEUE_FLAG_ELVSWITCH	8	/* don't use elevator, just do FIFO */
 #define QUEUE_FLAG_BIDI		9	/* queue supports bidi requests */
 #define QUEUE_FLAG_NOMERGES    10	/* disable merge attempts */
+#define QUEUE_FLAG_SAME_COMP   11	/* force complete on same CPU */
+#define QUEUE_FLAG_FAIL_IO     12	/* fake timeout */
+#define QUEUE_FLAG_STACKABLE   13	/* supports request stacking */
+#define QUEUE_FLAG_NONROT      14	/* non-rotational device (SSD) */
 
 static inline int queue_is_locked(struct request_queue *q)
 {
@@ -526,7 +550,10 @@ enum {
 #define blk_queue_tagged(q)	test_bit(QUEUE_FLAG_QUEUED, &(q)->queue_flags)
 #define blk_queue_stopped(q)	test_bit(QUEUE_FLAG_STOPPED, &(q)->queue_flags)
 #define blk_queue_nomerges(q)	test_bit(QUEUE_FLAG_NOMERGES, &(q)->queue_flags)
+#define blk_queue_nonrot(q)	test_bit(QUEUE_FLAG_NONROT, &(q)->queue_flags)
 #define blk_queue_flushing(q)	((q)->ordseq)
+#define blk_queue_stackable(q)	\
+	test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
 
 #define blk_fs_request(rq)	((rq)->cmd_type == REQ_TYPE_FS)
 #define blk_pc_request(rq)	((rq)->cmd_type == REQ_TYPE_BLOCK_PC)
@@ -536,16 +563,18 @@ enum {
 #define blk_noretry_request(rq)	((rq)->cmd_flags & REQ_FAILFAST)
 #define blk_rq_started(rq)	((rq)->cmd_flags & REQ_STARTED)
 
-#define blk_account_rq(rq)	(blk_rq_started(rq) && blk_fs_request(rq))
+#define blk_account_rq(rq)	(blk_rq_started(rq) && (blk_fs_request(rq) || blk_discard_rq(rq))) 
 
 #define blk_pm_suspend_request(rq)	((rq)->cmd_type == REQ_TYPE_PM_SUSPEND)
 #define blk_pm_resume_request(rq)	((rq)->cmd_type == REQ_TYPE_PM_RESUME)
 #define blk_pm_request(rq)	\
 	(blk_pm_suspend_request(rq) || blk_pm_resume_request(rq))
 
+#define blk_rq_cpu_valid(rq)	((rq)->cpu != -1)
 #define blk_sorted_rq(rq)	((rq)->cmd_flags & REQ_SORTED)
 #define blk_barrier_rq(rq)	((rq)->cmd_flags & REQ_HARDBARRIER)
 #define blk_fua_rq(rq)		((rq)->cmd_flags & REQ_FUA)
+#define blk_discard_rq(rq)	((rq)->cmd_flags & REQ_DISCARD)
 #define blk_bidi_rq(rq)		((rq)->next_rq != NULL)
 #define blk_empty_barrier(rq)	(blk_barrier_rq(rq) && blk_fs_request(rq) && !(rq)->hard_nr_sectors)
 /* rq->queuelist of dequeued request must be list_empty() */
@@ -592,7 +621,8 @@ static inline void blk_clear_queue_full(struct request_queue *q, int rw)
 #define RQ_NOMERGE_FLAGS	\
 	(REQ_NOMERGE | REQ_STARTED | REQ_HARDBARRIER | REQ_SOFTBARRIER)
 #define rq_mergeable(rq)	\
-	(!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && blk_fs_request((rq)))
+	(!((rq)->cmd_flags & RQ_NOMERGE_FLAGS) && \
+	 (blk_discard_rq(rq) || blk_fs_request((rq))))
 
 /*
  * q->prep_rq_fn return values
@@ -637,6 +667,12 @@ static inline void blk_queue_bounce(struct request_queue *q, struct bio **bio)
 }
 #endif /* CONFIG_MMU */
 
+struct rq_map_data {
+	struct page **pages;
+	int page_order;
+	int nr_entries;
+};
+
 struct req_iterator {
 	int i;
 	struct bio *bio;
@@ -664,6 +700,10 @@ extern void __blk_put_request(struct request_queue *, struct request *);
 extern struct request *blk_get_request(struct request_queue *, int, gfp_t);
 extern void blk_insert_request(struct request_queue *, struct request *, int, void *);
 extern void blk_requeue_request(struct request_queue *, struct request *);
+extern int blk_rq_check_limits(struct request_queue *q, struct request *rq);
+extern int blk_lld_busy(struct request_queue *q);
+extern int blk_insert_cloned_request(struct request_queue *q,
+				     struct request *rq);
 extern void blk_plug_device(struct request_queue *);
 extern void blk_plug_device_unlocked(struct request_queue *);
 extern int blk_remove_plug(struct request_queue *);
@@ -705,11 +745,14 @@ extern void __blk_stop_queue(struct request_queue *q);
 extern void __blk_run_queue(struct request_queue *);
 extern void blk_run_queue(struct request_queue *);
 extern void blk_start_queueing(struct request_queue *);
-extern int blk_rq_map_user(struct request_queue *, struct request *, void __user *, unsigned long);
+extern int blk_rq_map_user(struct request_queue *, struct request *,
+			   struct rq_map_data *, void __user *, unsigned long,
+			   gfp_t);
 extern int blk_rq_unmap_user(struct bio *);
 extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, unsigned int, gfp_t);
 extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
-			       struct sg_iovec *, int, unsigned int);
+			       struct rq_map_data *, struct sg_iovec *, int,
+			       unsigned int, gfp_t);
 extern int blk_execute_rq(struct request_queue *, struct gendisk *,
 			  struct request *, int);
 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
@@ -750,12 +793,15 @@ extern int __blk_end_request(struct request *rq, int error,
 extern int blk_end_bidi_request(struct request *rq, int error,
 				unsigned int nr_bytes, unsigned int bidi_bytes);
 extern void end_request(struct request *, int);
-extern void end_queued_request(struct request *, int);
-extern void end_dequeued_request(struct request *, int);
 extern int blk_end_request_callback(struct request *rq, int error,
 				unsigned int nr_bytes,
 				int (drv_callback)(struct request *));
 extern void blk_complete_request(struct request *);
+extern void __blk_complete_request(struct request *);
+extern void blk_abort_request(struct request *);
+extern void blk_abort_queue(struct request_queue *);
+extern void blk_update_request(struct request *rq, int error,
+			       unsigned int nr_bytes);
 
 /*
  * blk_end_request() takes bytes instead of sectors as a complete size.
@@ -790,12 +836,16 @@ extern void blk_queue_update_dma_pad(struct request_queue *, unsigned int);
 extern int blk_queue_dma_drain(struct request_queue *q,
 			       dma_drain_needed_fn *dma_drain_needed,
 			       void *buf, unsigned int size);
+extern void blk_queue_lld_busy(struct request_queue *q, lld_busy_fn *fn);
 extern void blk_queue_segment_boundary(struct request_queue *, unsigned long);
 extern void blk_queue_prep_rq(struct request_queue *, prep_rq_fn *pfn);
 extern void blk_queue_merge_bvec(struct request_queue *, merge_bvec_fn *);
 extern void blk_queue_dma_alignment(struct request_queue *, int);
 extern void blk_queue_update_dma_alignment(struct request_queue *, int);
 extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *);
+extern void blk_queue_set_discard(struct request_queue *, prepare_discard_fn *);
+extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *);
+extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
 extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev);
 extern int blk_queue_ordered(struct request_queue *, unsigned, prepare_flush_fn *);
 extern int blk_do_ordered(struct request_queue *, struct request **);
@@ -837,6 +887,16 @@ static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
 }
 
 extern int blkdev_issue_flush(struct block_device *, sector_t *);
+extern int blkdev_issue_discard(struct block_device *,
+				sector_t sector, sector_t nr_sects, gfp_t);
+
+static inline int sb_issue_discard(struct super_block *sb,
+				   sector_t block, sector_t nr_blocks)
+{
+	block <<= (sb->s_blocksize_bits - 9);
+	nr_blocks <<= (sb->s_blocksize_bits - 9);
+	return blkdev_issue_discard(sb->s_bdev, block, nr_blocks, GFP_KERNEL);
+}
 
 /*
 * command filter functions
@@ -874,6 +934,13 @@ static inline int queue_dma_alignment(struct request_queue *q)
 	return q ? q->dma_alignment : 511;
 }
 
+static inline int blk_rq_aligned(struct request_queue *q, void *addr,
+				 unsigned int len)
+{
+	unsigned int alignment = queue_dma_alignment(q) | q->dma_pad_mask;
+	return !((unsigned long)addr & alignment) && !(len & alignment);
+}
+
 /* assumes size > 256 */
 static inline unsigned int blksize_bits(unsigned int size)
 {
@@ -900,7 +967,7 @@ static inline void put_dev_sector(Sector p)
 }
 
 struct work_struct;
-int kblockd_schedule_work(struct work_struct *work);
+int kblockd_schedule_work(struct request_queue *q, struct work_struct *work);
 void kblockd_flush_work(struct work_struct *work);
 
 #define MODULE_ALIAS_BLOCKDEV(major,minor) \
@@ -945,49 +1012,19 @@ struct blk_integrity {
 
 extern int blk_integrity_register(struct gendisk *, struct blk_integrity *);
 extern void blk_integrity_unregister(struct gendisk *);
-extern int blk_integrity_compare(struct block_device *, struct block_device *);
+extern int blk_integrity_compare(struct gendisk *, struct gendisk *);
 extern int blk_rq_map_integrity_sg(struct request *, struct scatterlist *);
 extern int blk_rq_count_integrity_sg(struct request *);
 
-static inline unsigned short blk_integrity_tuple_size(struct blk_integrity *bi)
-{
-	if (bi)
-		return bi->tuple_size;
-
-	return 0;
-}
-
-static inline struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
+static inline
+struct blk_integrity *bdev_get_integrity(struct block_device *bdev)
 {
 	return bdev->bd_disk->integrity;
 }
 
-static inline unsigned int bdev_get_tag_size(struct block_device *bdev)
+static inline struct blk_integrity *blk_get_integrity(struct gendisk *disk)
 {
-	struct blk_integrity *bi = bdev_get_integrity(bdev);
-
-	if (bi)
-		return bi->tag_size;
-
-	return 0;
-}
-
-static inline int bdev_integrity_enabled(struct block_device *bdev, int rw)
-{
-	struct blk_integrity *bi = bdev_get_integrity(bdev);
-
-	if (bi == NULL)
-		return 0;
-
-	if (rw == READ && bi->verify_fn != NULL &&
-	    (bi->flags & INTEGRITY_FLAG_READ))
-		return 1;
-
-	if (rw == WRITE && bi->generate_fn != NULL &&
-	    (bi->flags & INTEGRITY_FLAG_WRITE))
-		return 1;
-
-	return 0;
+	return disk->integrity;
 }
 
 static inline int blk_integrity_rq(struct request *rq)
@@ -1004,7 +1041,7 @@ static inline int blk_integrity_rq(struct request *rq)
 #define blk_rq_count_integrity_sg(a)		(0)
 #define blk_rq_map_integrity_sg(a, b)		(0)
 #define bdev_get_integrity(a)			(0)
-#define bdev_get_tag_size(a)			(0)
+#define blk_get_integrity(a)			(0)
 #define blk_integrity_compare(a, b)		(0)
 #define blk_integrity_register(a, b)		(0)
 #define blk_integrity_unregister(a)		do { } while (0);
diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h
index d084b8d227a..3a31eb50616 100644
--- a/include/linux/blktrace_api.h
+++ b/include/linux/blktrace_api.h
@@ -1,8 +1,10 @@
 #ifndef BLKTRACE_H
 #define BLKTRACE_H
 
+#ifdef __KERNEL__
 #include <linux/blkdev.h>
 #include <linux/relay.h>
+#endif
 
 /*
  * Trace categories
@@ -21,6 +23,7 @@ enum blktrace_cat {
 	BLK_TC_NOTIFY	= 1 << 10,	/* special message */
 	BLK_TC_AHEAD	= 1 << 11,	/* readahead */
 	BLK_TC_META	= 1 << 12,	/* metadata */
+	BLK_TC_DISCARD	= 1 << 13,	/* discard requests */
 
 	BLK_TC_END	= 1 << 15,	/* only 16-bits, reminder */
 };
@@ -47,6 +50,7 @@ enum blktrace_act {
 	__BLK_TA_SPLIT,			/* bio was split */
 	__BLK_TA_BOUNCE,		/* bio was bounced */
 	__BLK_TA_REMAP,			/* bio was remapped */
+	__BLK_TA_ABORT,			/* request aborted */
 };
 
 /*
@@ -77,6 +81,7 @@ enum blktrace_notify {
 #define BLK_TA_SPLIT		(__BLK_TA_SPLIT)
 #define BLK_TA_BOUNCE		(__BLK_TA_BOUNCE)
 #define BLK_TA_REMAP		(__BLK_TA_REMAP | BLK_TC_ACT(BLK_TC_QUEUE))
+#define BLK_TA_ABORT		(__BLK_TA_ABORT | BLK_TC_ACT(BLK_TC_QUEUE))
 
 #define BLK_TN_PROCESS		(__BLK_TN_PROCESS | BLK_TC_ACT(BLK_TC_NOTIFY))
 #define BLK_TN_TIMESTAMP	(__BLK_TN_TIMESTAMP | BLK_TC_ACT(BLK_TC_NOTIFY))
@@ -89,17 +94,17 @@ enum blktrace_notify {
  * The trace itself
  */
 struct blk_io_trace {
-	u32 magic;		/* MAGIC << 8 | version */
-	u32 sequence;		/* event number */
-	u64 time;		/* in microseconds */
-	u64 sector;		/* disk offset */
-	u32 bytes;		/* transfer length */
-	u32 action;		/* what happened */
-	u32 pid;		/* who did it */
-	u32 device;		/* device number */
-	u32 cpu;		/* on what cpu did it happen */
-	u16 error;		/* completion error */
-	u16 pdu_len;		/* length of data after this trace */
+	__u32 magic;		/* MAGIC << 8 | version */
+	__u32 sequence;		/* event number */
+	__u64 time;		/* in microseconds */
+	__u64 sector;		/* disk offset */
+	__u32 bytes;		/* transfer length */
+	__u32 action;		/* what happened */
+	__u32 pid;		/* who did it */
+	__u32 device;		/* device number */
+	__u32 cpu;		/* on what cpu did it happen */
+	__u16 error;		/* completion error */
+	__u16 pdu_len;		/* length of data after this trace */
 };
 
 /*
@@ -117,6 +122,23 @@ enum {
 	Blktrace_stopped,
 };
 
+#define BLKTRACE_BDEV_SIZE	32
+
+/*
+ * User setup structure passed with BLKTRACESTART
+ */
+struct blk_user_trace_setup {
+	char name[BLKTRACE_BDEV_SIZE];	/* output */
+	__u16 act_mask;			/* input */
+	__u32 buf_size;			/* input */
+	__u32 buf_nr;			/* input */
+	__u64 start_lba;
+	__u64 end_lba;
+	__u32 pid;
+};
+
+#ifdef __KERNEL__
+#if defined(CONFIG_BLK_DEV_IO_TRACE)
 struct blk_trace {
 	int trace_state;
 	struct rchan *rchan;
@@ -133,21 +155,6 @@ struct blk_trace {
 	atomic_t dropped;
 };
 
-/*
- * User setup structure passed with BLKTRACESTART
- */
-struct blk_user_trace_setup {
-	char name[BDEVNAME_SIZE];	/* output */
-	u16 act_mask;			/* input */
-	u32 buf_size;			/* input */
-	u32 buf_nr;			/* input */
-	u64 start_lba;
-	u64 end_lba;
-	u32 pid;
-};
-
-#ifdef __KERNEL__
-#if defined(CONFIG_BLK_DEV_IO_TRACE)
 extern int blk_trace_ioctl(struct block_device *, unsigned, char __user *);
 extern void blk_trace_shutdown(struct request_queue *);
 extern void __blk_add_trace(struct blk_trace *, sector_t, int, int, u32, int, int, void *);
@@ -195,6 +202,9 @@ static inline void blk_add_trace_rq(struct request_queue *q, struct request *rq,
 	if (likely(!bt))
 		return;
 
+	if (blk_discard_rq(rq))
+		rw |= (1 << BIO_RW_DISCARD);
+
 	if (blk_pc_request(rq)) {
 		what |= BLK_TC_ACT(BLK_TC_PC);
 		__blk_add_trace(bt, 0, rq->data_len, rw, what, rq->errors, sizeof(rq->cmd), rq->cmd);
diff --git a/include/linux/device.h b/include/linux/device.h
index 4d8372d135d..246937c9cbc 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -199,6 +199,11 @@ struct class {
 	struct class_private *p;
 };
 
+struct class_dev_iter {
+	struct klist_iter		ki;
+	const struct device_type	*type;
+};
+
 extern struct kobject *sysfs_dev_block_kobj;
 extern struct kobject *sysfs_dev_char_kobj;
 extern int __must_check __class_register(struct class *class,
@@ -213,6 +218,13 @@ extern void class_unregister(struct class *class);
 	__class_register(class, &__key);	\
 })
 
+extern void class_dev_iter_init(struct class_dev_iter *iter,
+				struct class *class,
+				struct device *start,
+				const struct device_type *type);
+extern struct device *class_dev_iter_next(struct class_dev_iter *iter);
+extern void class_dev_iter_exit(struct class_dev_iter *iter);
+
 extern int class_for_each_device(struct class *class, struct device *start,
 				 void *data,
 				 int (*fn)(struct device *dev, void *data));
@@ -396,7 +408,7 @@ struct device {
 	spinlock_t		devres_lock;
 	struct list_head	devres_head;
 
-	struct list_head	node;
+	struct klist_node	knode_class;
 	struct class		*class;
 	dev_t			devt;	/* dev_t, creates the sysfs "dev" */
 	struct attribute_group	**groups;	/* optional groups */
diff --git a/include/linux/elevator.h b/include/linux/elevator.h
index 639624b55fb..92f6f634e3e 100644
--- a/include/linux/elevator.h
+++ b/include/linux/elevator.h
@@ -112,6 +112,7 @@ extern struct request *elv_latter_request(struct request_queue *, struct request
 extern int elv_register_queue(struct request_queue *q);
 extern void elv_unregister_queue(struct request_queue *q);
 extern int elv_may_queue(struct request_queue *, int);
+extern void elv_abort_queue(struct request_queue *);
 extern void elv_completed_request(struct request_queue *, struct request *);
 extern int elv_set_request(struct request_queue *, struct request *, gfp_t);
 extern void elv_put_request(struct request_queue *, struct request *);
@@ -173,15 +174,15 @@ enum {
 #define rb_entry_rq(node)	rb_entry((node), struct request, rb_node)
 
 /*
- * Hack to reuse the donelist list_head as the fifo time holder while
+ * Hack to reuse the csd.list list_head as the fifo time holder while
  * the request is in the io scheduler. Saves an unsigned long in rq.
  */
-#define rq_fifo_time(rq)	((unsigned long) (rq)->donelist.next)
-#define rq_set_fifo_time(rq,exp)	((rq)->donelist.next = (void *) (exp))
+#define rq_fifo_time(rq)	((unsigned long) (rq)->csd.list.next)
+#define rq_set_fifo_time(rq,exp)	((rq)->csd.list.next = (void *) (exp))
 #define rq_entry_fifo(ptr)	list_entry((ptr), struct request, queuelist)
 #define rq_fifo_clear(rq)	do {		\
 	list_del_init(&(rq)->queuelist);	\
-	INIT_LIST_HEAD(&(rq)->donelist);	\
+	INIT_LIST_HEAD(&(rq)->csd.list);	\
 	} while (0)
 
 /*
diff --git a/include/linux/fd.h b/include/linux/fd.h
index b6bd41d2b46..f5d194af07a 100644
--- a/include/linux/fd.h
+++ b/include/linux/fd.h
@@ -15,10 +15,16 @@ struct floppy_struct {
 			sect,		/* sectors per track */
 			head,		/* nr of heads */
 			track,		/* nr of tracks */
-			stretch;	/* !=0 means double track steps */
+			stretch;	/* bit 0 !=0 means double track steps */
+					/* bit 1 != 0 means swap sides */
+					/* bits 2..9 give the first sector */
+					/*  number (the LSB is flipped) */
 #define FD_STRETCH 1
 #define FD_SWAPSIDES 2
 #define FD_ZEROBASED 4
+#define FD_SECTBASEMASK 0x3FC
+#define FD_MKSECTBASE(s) (((s) ^ 1) << 2)
+#define FD_SECTBASE(floppy) ((((floppy)->stretch & FD_SECTBASEMASK) >> 2) ^ 1)
 
 	unsigned char	gap,		/* gap1 size */
 
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 580b513668f..32477e8872d 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -86,7 +86,9 @@ extern int dir_notify_enable;
 #define READ_META	(READ | (1 << BIO_RW_META))
 #define WRITE_SYNC	(WRITE | (1 << BIO_RW_SYNC))
 #define SWRITE_SYNC	(SWRITE | (1 << BIO_RW_SYNC))
-#define WRITE_BARRIER	((1 << BIO_RW) | (1 << BIO_RW_BARRIER))
+#define WRITE_BARRIER	(WRITE | (1 << BIO_RW_BARRIER))
+#define DISCARD_NOBARRIER (1 << BIO_RW_DISCARD)
+#define DISCARD_BARRIER ((1 << BIO_RW_DISCARD) | (1 << BIO_RW_BARRIER))
 
 #define SEL_IN		1
 #define SEL_OUT		2
@@ -222,6 +224,7 @@ extern int dir_notify_enable;
 #define BLKTRACESTART _IO(0x12,116)
 #define BLKTRACESTOP _IO(0x12,117)
 #define BLKTRACETEARDOWN _IO(0x12,118)
+#define BLKDISCARD _IO(0x12,119)
 
 #define BMAP_IOCTL 1		/* obsolete - kept for compatibility */
 #define FIBMAP	   _IO(0x00,1)	/* bmap access */
@@ -1682,6 +1685,7 @@ extern void chrdev_show(struct seq_file *,off_t);
 
 /* fs/block_dev.c */
 #define BDEVNAME_SIZE	32	/* Largest string for a blockdev identifier */
+#define BDEVT_SIZE	10	/* Largest string for MAJ:MIN for blkdev */
 
 #ifdef CONFIG_BLOCK
 #define BLKDEV_MAJOR_HASH_SIZE	255
@@ -1718,6 +1722,9 @@ extern int fs_may_remount_ro(struct super_block *);
  */
 #define bio_data_dir(bio)	((bio)->bi_rw & 1)
 
+extern void check_disk_size_change(struct gendisk *disk,
+				   struct block_device *bdev);
+extern int revalidate_disk(struct gendisk *);
 extern int check_disk_change(struct block_device *);
 extern int __invalidate_device(struct block_device *);
 extern int invalidate_partition(struct gendisk *, int);
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index be4f5e5bfe0..206cdf96c3a 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -11,12 +11,15 @@
 
 #include <linux/types.h>
 #include <linux/kdev_t.h>
+#include <linux/rcupdate.h>
 
 #ifdef CONFIG_BLOCK
 
-#define kobj_to_dev(k) container_of(k, struct device, kobj)
-#define dev_to_disk(device) container_of(device, struct gendisk, dev)
-#define dev_to_part(device) container_of(device, struct hd_struct, dev)
+#define kobj_to_dev(k)		container_of((k), struct device, kobj)
+#define dev_to_disk(device)	container_of((device), struct gendisk, part0.__dev)
+#define dev_to_part(device)	container_of((device), struct hd_struct, __dev)
+#define disk_to_dev(disk)	(&(disk)->part0.__dev)
+#define part_to_dev(part)	(&((part)->__dev))
 
 extern struct device_type part_type;
 extern struct kobject *block_depr;
@@ -55,6 +58,9 @@ enum {
 	UNIXWARE_PARTITION = 0x63,	/* Same as GNU_HURD and SCO Unix */
 };
 
+#define DISK_MAX_PARTS			256
+#define DISK_NAME_LEN			32
+
 #include <linux/major.h>
 #include <linux/device.h>
 #include <linux/smp.h>
@@ -87,7 +93,7 @@ struct disk_stats {
 struct hd_struct {
 	sector_t start_sect;
 	sector_t nr_sects;
-	struct device dev;
+	struct device __dev;
 	struct kobject *holder_dir;
 	int policy, partno;
 #ifdef CONFIG_FAIL_MAKE_REQUEST
@@ -100,6 +106,7 @@ struct hd_struct {
 #else
 	struct disk_stats dkstats;
 #endif
+	struct rcu_head rcu_head;
 };
 
 #define GENHD_FL_REMOVABLE			1
@@ -108,100 +115,148 @@ struct hd_struct {
 #define GENHD_FL_CD				8
 #define GENHD_FL_UP				16
 #define GENHD_FL_SUPPRESS_PARTITION_INFO	32
-#define GENHD_FL_FAIL				64
+#define GENHD_FL_EXT_DEVT			64 /* allow extended devt */
+
+#define BLK_SCSI_MAX_CMDS	(256)
+#define BLK_SCSI_CMD_PER_LONG	(BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
+
+struct blk_scsi_cmd_filter {
+	unsigned long read_ok[BLK_SCSI_CMD_PER_LONG];
+	unsigned long write_ok[BLK_SCSI_CMD_PER_LONG];
+	struct kobject kobj;
+};
+
+struct disk_part_tbl {
+	struct rcu_head rcu_head;
+	int len;
+	struct hd_struct *part[];
+};
 
 struct gendisk {
+	/* major, first_minor and minors are input parameters only,
+	 * don't use directly.  Use disk_devt() and disk_max_parts().
+	 */
 	int major;			/* major number of driver */
 	int first_minor;
 	int minors;                     /* maximum number of minors, =1 for
                                          * disks that can't be partitioned. */
-	char disk_name[32];		/* name of major driver */
-	struct hd_struct **part;	/* [indexed by minor] */
+
+	char disk_name[DISK_NAME_LEN];	/* name of major driver */
+
+	/* Array of pointers to partitions indexed by partno.
+	 * Protected with matching bdev lock but stat and other
+	 * non-critical accesses use RCU.  Always access through
+	 * helpers.
+	 */
+	struct disk_part_tbl *part_tbl;
+	struct hd_struct part0;
+
 	struct block_device_operations *fops;
 	struct request_queue *queue;
 	void *private_data;
-	sector_t capacity;
 
 	int flags;
 	struct device *driverfs_dev;  // FIXME: remove
-	struct device dev;
-	struct kobject *holder_dir;
 	struct kobject *slave_dir;
 
 	struct timer_rand_state *random;
-	int policy;
 
 	atomic_t sync_io;		/* RAID */
-	unsigned long stamp;
-	int in_flight;
-#ifdef	CONFIG_SMP
-	struct disk_stats *dkstats;
-#else
-	struct disk_stats dkstats;
-#endif
 	struct work_struct async_notify;
 #ifdef  CONFIG_BLK_DEV_INTEGRITY
 	struct blk_integrity *integrity;
 #endif
+	int node_id;
 };
 
-/* 
- * Macros to operate on percpu disk statistics:
- *
- * The __ variants should only be called in critical sections. The full
- * variants disable/enable preemption.
- */
-static inline struct hd_struct *get_part(struct gendisk *gendiskp,
-					 sector_t sector)
+static inline struct gendisk *part_to_disk(struct hd_struct *part)
 {
-	struct hd_struct *part;
-	int i;
-	for (i = 0; i < gendiskp->minors - 1; i++) {
-		part = gendiskp->part[i];
-		if (part && part->start_sect <= sector
-		    && sector < part->start_sect + part->nr_sects)
-			return part;
+	if (likely(part)) {
+		if (part->partno)
+			return dev_to_disk(part_to_dev(part)->parent);
+		else
+			return dev_to_disk(part_to_dev(part));
 	}
 	return NULL;
 }
 
-#ifdef	CONFIG_SMP
-#define __disk_stat_add(gendiskp, field, addnd) 	\
-	(per_cpu_ptr(gendiskp->dkstats, smp_processor_id())->field += addnd)
+static inline int disk_max_parts(struct gendisk *disk)
+{
+	if (disk->flags & GENHD_FL_EXT_DEVT)
+		return DISK_MAX_PARTS;
+	return disk->minors;
+}
 
-#define disk_stat_read(gendiskp, field)					\
-({									\
-	typeof(gendiskp->dkstats->field) res = 0;			\
-	int i;								\
-	for_each_possible_cpu(i)					\
-		res += per_cpu_ptr(gendiskp->dkstats, i)->field;	\
-	res;								\
-})
+static inline bool disk_partitionable(struct gendisk *disk)
+{
+	return disk_max_parts(disk) > 1;
+}
 
-static inline void disk_stat_set_all(struct gendisk *gendiskp, int value)	{
-	int i;
+static inline dev_t disk_devt(struct gendisk *disk)
+{
+	return disk_to_dev(disk)->devt;
+}
 
-	for_each_possible_cpu(i)
-		memset(per_cpu_ptr(gendiskp->dkstats, i), value,
-				sizeof(struct disk_stats));
-}		
+static inline dev_t part_devt(struct hd_struct *part)
+{
+	return part_to_dev(part)->devt;
+}
 
-#define __part_stat_add(part, field, addnd)				\
-	(per_cpu_ptr(part->dkstats, smp_processor_id())->field += addnd)
+extern struct hd_struct *disk_get_part(struct gendisk *disk, int partno);
 
-#define __all_stat_add(gendiskp, part, field, addnd, sector)	\
-({								\
-	if (part)						\
-		__part_stat_add(part, field, addnd);		\
-	__disk_stat_add(gendiskp, field, addnd);		\
-})
+static inline void disk_put_part(struct hd_struct *part)
+{
+	if (likely(part))
+		put_device(part_to_dev(part));
+}
+
+/*
+ * Smarter partition iterator without context limits.
+ */
+#define DISK_PITER_REVERSE	(1 << 0) /* iterate in the reverse direction */
+#define DISK_PITER_INCL_EMPTY	(1 << 1) /* include 0-sized parts */
+#define DISK_PITER_INCL_PART0	(1 << 2) /* include partition 0 */
+
+struct disk_part_iter {
+	struct gendisk		*disk;
+	struct hd_struct	*part;
+	int			idx;
+	unsigned int		flags;
+};
+
+extern void disk_part_iter_init(struct disk_part_iter *piter,
+				 struct gendisk *disk, unsigned int flags);
+extern struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter);
+extern void disk_part_iter_exit(struct disk_part_iter *piter);
+
+extern struct hd_struct *disk_map_sector_rcu(struct gendisk *disk,
+					     sector_t sector);
+
+/*
+ * Macros to operate on percpu disk statistics:
+ *
+ * {disk|part|all}_stat_{add|sub|inc|dec}() modify the stat counters
+ * and should be called between disk_stat_lock() and
+ * disk_stat_unlock().
+ *
+ * part_stat_read() can be called at any time.
+ *
+ * part_stat_{add|set_all}() and {init|free}_part_stats are for
+ * internal use only.
+ */
+#ifdef	CONFIG_SMP
+#define part_stat_lock()	({ rcu_read_lock(); get_cpu(); })
+#define part_stat_unlock()	do { put_cpu(); rcu_read_unlock(); } while (0)
+
+#define __part_stat_add(cpu, part, field, addnd)			\
+	(per_cpu_ptr((part)->dkstats, (cpu))->field += (addnd))
 
 #define part_stat_read(part, field)					\
 ({									\
-	typeof(part->dkstats->field) res = 0;				\
+	typeof((part)->dkstats->field) res = 0;				\
 	int i;								\
 	for_each_possible_cpu(i)					\
-		res += per_cpu_ptr(part->dkstats, i)->field;		\
+		res += per_cpu_ptr((part)->dkstats, i)->field;		\
 	res;								\
 })
 
@@ -213,171 +268,107 @@ static inline void part_stat_set_all(struct hd_struct *part, int value)
 		memset(per_cpu_ptr(part->dkstats, i), value,
 				sizeof(struct disk_stats));
 }
-				
-#else /* !CONFIG_SMP */
-#define __disk_stat_add(gendiskp, field, addnd) \
-				(gendiskp->dkstats.field += addnd)
-#define disk_stat_read(gendiskp, field)	(gendiskp->dkstats.field)
 
-static inline void disk_stat_set_all(struct gendisk *gendiskp, int value)
+static inline int init_part_stats(struct hd_struct *part)
 {
-	memset(&gendiskp->dkstats, value, sizeof (struct disk_stats));
+	part->dkstats = alloc_percpu(struct disk_stats);
+	if (!part->dkstats)
+		return 0;
+	return 1;
 }
 
-#define __part_stat_add(part, field, addnd) \
-	(part->dkstats.field += addnd)
-
-#define __all_stat_add(gendiskp, part, field, addnd, sector)	\
-({								\
-	if (part)						\
-		part->dkstats.field += addnd;			\
-	__disk_stat_add(gendiskp, field, addnd);		\
-})
-
-#define part_stat_read(part, field)	(part->dkstats.field)
-
-static inline void part_stat_set_all(struct hd_struct *part, int value)
+static inline void free_part_stats(struct hd_struct *part)
 {
-	memset(&part->dkstats, value, sizeof(struct disk_stats));
+	free_percpu(part->dkstats);
 }
 
-#endif /* CONFIG_SMP */
+#else /* !CONFIG_SMP */
+#define part_stat_lock()	({ rcu_read_lock(); 0; })
+#define part_stat_unlock()	rcu_read_unlock()
 
-#define disk_stat_add(gendiskp, field, addnd)			\
-	do {							\
-		preempt_disable();				\
-		__disk_stat_add(gendiskp, field, addnd);	\
-		preempt_enable();				\
-	} while (0)
-
-#define __disk_stat_dec(gendiskp, field) __disk_stat_add(gendiskp, field, -1)
-#define disk_stat_dec(gendiskp, field) disk_stat_add(gendiskp, field, -1)
-
-#define __disk_stat_inc(gendiskp, field) __disk_stat_add(gendiskp, field, 1)
-#define disk_stat_inc(gendiskp, field) disk_stat_add(gendiskp, field, 1)
-
-#define __disk_stat_sub(gendiskp, field, subnd) \
-		__disk_stat_add(gendiskp, field, -subnd)
-#define disk_stat_sub(gendiskp, field, subnd) \
-		disk_stat_add(gendiskp, field, -subnd)
-
-#define part_stat_add(gendiskp, field, addnd)		\
-	do {						\
-		preempt_disable();			\
-		__part_stat_add(gendiskp, field, addnd);\
-		preempt_enable();			\
-	} while (0)
-
-#define __part_stat_dec(gendiskp, field) __part_stat_add(gendiskp, field, -1)
-#define part_stat_dec(gendiskp, field) part_stat_add(gendiskp, field, -1)
-
-#define __part_stat_inc(gendiskp, field) __part_stat_add(gendiskp, field, 1)
-#define part_stat_inc(gendiskp, field) part_stat_add(gendiskp, field, 1)
-
-#define __part_stat_sub(gendiskp, field, subnd) \
-		__part_stat_add(gendiskp, field, -subnd)
-#define part_stat_sub(gendiskp, field, subnd) \
-		part_stat_add(gendiskp, field, -subnd)
-
-#define all_stat_add(gendiskp, part, field, addnd, sector)	\
-	do {							\
-		preempt_disable();				\
-		__all_stat_add(gendiskp, part, field, addnd, sector);	\
-		preempt_enable();				\
-	} while (0)
-
-#define __all_stat_dec(gendiskp, field, sector) \
-		__all_stat_add(gendiskp, field, -1, sector)
-#define all_stat_dec(gendiskp, field, sector) \
-		all_stat_add(gendiskp, field, -1, sector)
-
-#define __all_stat_inc(gendiskp, part, field, sector) \
-		__all_stat_add(gendiskp, part, field, 1, sector)
-#define all_stat_inc(gendiskp, part, field, sector) \
-		all_stat_add(gendiskp, part, field, 1, sector)
-
-#define __all_stat_sub(gendiskp, part, field, subnd, sector) \
-		__all_stat_add(gendiskp, part, field, -subnd, sector)
-#define all_stat_sub(gendiskp, part, field, subnd, sector) \
-		all_stat_add(gendiskp, part, field, -subnd, sector)
-
-/* Inlines to alloc and free disk stats in struct gendisk */
-#ifdef  CONFIG_SMP
-static inline int init_disk_stats(struct gendisk *disk)
-{
-	disk->dkstats = alloc_percpu(struct disk_stats);
-	if (!disk->dkstats)
-		return 0;
-	return 1;
-}
+#define __part_stat_add(cpu, part, field, addnd)				\
+	((part)->dkstats.field += addnd)
+
+#define part_stat_read(part, field)	((part)->dkstats.field)
 
-static inline void free_disk_stats(struct gendisk *disk)
+static inline void part_stat_set_all(struct hd_struct *part, int value)
 {
-	free_percpu(disk->dkstats);
+	memset(&part->dkstats, value, sizeof(struct disk_stats));
 }
 
 static inline int init_part_stats(struct hd_struct *part)
 {
-	part->dkstats = alloc_percpu(struct disk_stats);
-	if (!part->dkstats)
-		return 0;
 	return 1;
 }
 
 static inline void free_part_stats(struct hd_struct *part)
 {
-	free_percpu(part->dkstats);
-}
-
-#else	/* CONFIG_SMP */
-static inline int init_disk_stats(struct gendisk *disk)
-{
-	return 1;
 }
 
-static inline void free_disk_stats(struct gendisk *disk)
-{
-}
+#endif /* CONFIG_SMP */
 
-static inline int init_part_stats(struct hd_struct *part)
+#define part_stat_add(cpu, part, field, addnd)	do {			\
+	__part_stat_add((cpu), (part), field, addnd);			\
+	if ((part)->partno)						\
+		__part_stat_add((cpu), &part_to_disk((part))->part0,	\
+				field, addnd);				\
+} while (0)
+
+#define part_stat_dec(cpu, gendiskp, field)				\
+	part_stat_add(cpu, gendiskp, field, -1)
+#define part_stat_inc(cpu, gendiskp, field)				\
+	part_stat_add(cpu, gendiskp, field, 1)
+#define part_stat_sub(cpu, gendiskp, field, subnd)			\
+	part_stat_add(cpu, gendiskp, field, -subnd)
+
+static inline void part_inc_in_flight(struct hd_struct *part)
 {
-	return 1;
+	part->in_flight++;
+	if (part->partno)
+		part_to_disk(part)->part0.in_flight++;
 }
 
-static inline void free_part_stats(struct hd_struct *part)
+static inline void part_dec_in_flight(struct hd_struct *part)
 {
+	part->in_flight--;
+	if (part->partno)
+		part_to_disk(part)->part0.in_flight--;
 }
-#endif	/* CONFIG_SMP */
 
 /* drivers/block/ll_rw_blk.c */
-extern void disk_round_stats(struct gendisk *disk);
-extern void part_round_stats(struct hd_struct *part);
+extern void part_round_stats(int cpu, struct hd_struct *part);
 
 /* drivers/block/genhd.c */
 extern int get_blkdev_list(char *, int);
 extern void add_disk(struct gendisk *disk);
 extern void del_gendisk(struct gendisk *gp);
 extern void unlink_gendisk(struct gendisk *gp);
-extern struct gendisk *get_gendisk(dev_t dev, int *part);
+extern struct gendisk *get_gendisk(dev_t dev, int *partno);
+extern struct block_device *bdget_disk(struct gendisk *disk, int partno);
 
 extern void set_device_ro(struct block_device *bdev, int flag);
 extern void set_disk_ro(struct gendisk *disk, int flag);
 
+static inline int get_disk_ro(struct gendisk *disk)
+{
+	return disk->part0.policy;
+}
+
 /* drivers/char/random.c */
 extern void add_disk_randomness(struct gendisk *disk);
 extern void rand_initialize_disk(struct gendisk *disk);
 
 static inline sector_t get_start_sect(struct block_device *bdev)
 {
-	return bdev->bd_contains == bdev ? 0 : bdev->bd_part->start_sect;
+	return bdev->bd_part->start_sect;
 }
 static inline sector_t get_capacity(struct gendisk *disk)
 {
-	return disk->capacity;
+	return disk->part0.nr_sects;
 }
 static inline void set_capacity(struct gendisk *disk, sector_t size)
 {
-	disk->capacity = size;
+	disk->part0.nr_sects = size;
 }
 
 #ifdef CONFIG_SOLARIS_X86_PARTITION
@@ -527,9 +518,12 @@ struct unixware_disklabel {
 #define ADDPART_FLAG_RAID	1
 #define ADDPART_FLAG_WHOLEDISK	2
 
-extern dev_t blk_lookup_devt(const char *name, int part);
-extern char *disk_name (struct gendisk *hd, int part, char *buf);
+extern int blk_alloc_devt(struct hd_struct *part, dev_t *devt);
+extern void blk_free_devt(dev_t devt);
+extern dev_t blk_lookup_devt(const char *name, int partno);
+extern char *disk_name (struct gendisk *hd, int partno, char *buf);
 
+extern int disk_expand_part_tbl(struct gendisk *disk, int target);
 extern int rescan_partitions(struct gendisk *disk, struct block_device *bdev);
 extern int __must_check add_partition(struct gendisk *, int, sector_t, sector_t, int);
 extern void delete_partition(struct gendisk *, int);
@@ -546,16 +540,23 @@ extern void blk_register_region(dev_t devt, unsigned long range,
 			void *data);
 extern void blk_unregister_region(dev_t devt, unsigned long range);
 
-static inline struct block_device *bdget_disk(struct gendisk *disk, int index)
-{
-	return bdget(MKDEV(disk->major, disk->first_minor) + index);
-}
+extern ssize_t part_size_show(struct device *dev,
+			      struct device_attribute *attr, char *buf);
+extern ssize_t part_stat_show(struct device *dev,
+			      struct device_attribute *attr, char *buf);
+#ifdef CONFIG_FAIL_MAKE_REQUEST
+extern ssize_t part_fail_show(struct device *dev,
+			      struct device_attribute *attr, char *buf);
+extern ssize_t part_fail_store(struct device *dev,
+			       struct device_attribute *attr,
+			       const char *buf, size_t count);
+#endif /* CONFIG_FAIL_MAKE_REQUEST */
 
 #else /* CONFIG_BLOCK */
 
 static inline void printk_all_partitions(void) { }
 
-static inline dev_t blk_lookup_devt(const char *name, int part)
+static inline dev_t blk_lookup_devt(const char *name, int partno)
 {
 	dev_t devt = MKDEV(0, 0);
 	return devt;
diff --git a/include/linux/klist.h b/include/linux/klist.h
index 06c338ef7f1..8ea98db223e 100644
--- a/include/linux/klist.h
+++ b/include/linux/klist.h
@@ -38,7 +38,7 @@ extern void klist_init(struct klist *k, void (*get)(struct klist_node *),
 		       void (*put)(struct klist_node *));
 
 struct klist_node {
-	struct klist		*n_klist;
+	void			*n_klist;	/* never access directly */
 	struct list_head	n_node;
 	struct kref		n_ref;
 	struct completion	n_removed;
@@ -57,7 +57,6 @@ extern int klist_node_attached(struct klist_node *n);
 
 struct klist_iter {
 	struct klist		*i_klist;
-	struct list_head	*i_head;
 	struct klist_node	*i_cur;
 };
 
diff --git a/include/linux/major.h b/include/linux/major.h
index 53d5fafd85c..88249452b93 100644
--- a/include/linux/major.h
+++ b/include/linux/major.h
@@ -170,4 +170,6 @@
 
 #define VIOTAPE_MAJOR		230
 
+#define BLOCK_EXT_MAJOR		259
+
 #endif
diff --git a/include/linux/mtd/blktrans.h b/include/linux/mtd/blktrans.h
index 310e6160641..8b4aa0523db 100644
--- a/include/linux/mtd/blktrans.h
+++ b/include/linux/mtd/blktrans.h
@@ -41,6 +41,8 @@ struct mtd_blktrans_ops {
 		    unsigned long block, char *buffer);
 	int (*writesect)(struct mtd_blktrans_dev *dev,
 		     unsigned long block, char *buffer);
+	int (*discard)(struct mtd_blktrans_dev *dev,
+		       unsigned long block, unsigned nr_blocks);
 
 	/* Block layer ioctls */
 	int (*getgeo)(struct mtd_blktrans_dev *dev, struct hd_geometry *geo);
diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
index f9f6e793575..855bf95963e 100644
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -75,7 +75,6 @@ struct scsi_cmnd {
 
 	int retries;
 	int allowed;
-	int timeout_per_command;
 
 	unsigned char prot_op;
 	unsigned char prot_type;
@@ -86,7 +85,6 @@ struct scsi_cmnd {
 	/* These elements define the operation we are about to perform */
 	unsigned char *cmnd;
 
-	struct timer_list eh_timeout;	/* Used to time out the command. */
 
 	/* These elements define the operation we ultimately want to perform */
 	struct scsi_data_buffer sdb;
@@ -139,7 +137,6 @@ extern void scsi_put_command(struct scsi_cmnd *);
 extern void __scsi_put_command(struct Scsi_Host *, struct scsi_cmnd *,
 			       struct device *);
 extern void scsi_finish_command(struct scsi_cmnd *cmd);
-extern void scsi_req_abort_cmd(struct scsi_cmnd *cmd);
 
 extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
 				 size_t *offset, size_t *len);
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index 44a55d1bf53..d123ca84e73 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -43,13 +43,6 @@ struct blk_queue_tags;
 #define DISABLE_CLUSTERING 0
 #define ENABLE_CLUSTERING 1
 
-enum scsi_eh_timer_return {
-	EH_NOT_HANDLED,
-	EH_HANDLED,
-	EH_RESET_TIMER,
-};
-
-
 struct scsi_host_template {
 	struct module *module;
 	const char *name;
@@ -347,7 +340,7 @@ struct scsi_host_template {
 	 *
 	 * Status: OPTIONAL
 	 */
-	enum scsi_eh_timer_return (* eh_timed_out)(struct scsi_cmnd *);
+	enum blk_eh_timer_return (*eh_timed_out)(struct scsi_cmnd *);
 
 	/*
 	 * Name of proc directory
diff --git a/include/scsi/scsi_transport.h b/include/scsi/scsi_transport.h
index 490bd13a634..0de32cd4e8a 100644
--- a/include/scsi/scsi_transport.h
+++ b/include/scsi/scsi_transport.h
@@ -21,6 +21,7 @@
 #define SCSI_TRANSPORT_H
 
 #include <linux/transport_class.h>
+#include <linux/blkdev.h>
 #include <scsi/scsi_host.h>
 #include <scsi/scsi_device.h>
 
@@ -64,7 +65,7 @@ struct scsi_transport_template {
 	 *			begin counting again
 	 * EH_NOT_HANDLED	Begin normal error recovery
 	 */
-	enum scsi_eh_timer_return (* eh_timed_out)(struct scsi_cmnd *);
+	enum blk_eh_timer_return (*eh_timed_out)(struct scsi_cmnd *);
 
 	/*
 	 * Used as callback for the completion of i_t_nexus request
diff --git a/init/do_mounts.c b/init/do_mounts.c
index 3715feb8446..d055b1914c3 100644
--- a/init/do_mounts.c
+++ b/init/do_mounts.c
@@ -263,6 +263,10 @@ retry:
 		printk("Please append a correct \"root=\" boot option; here are the available partitions:\n");
 
 		printk_all_partitions();
+#ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT
+		printk("DEBUG_BLOCK_EXT_DEVT is enabled, you need to specify "
+		       "explicit textual name for \"root=\" boot option.\n");
+#endif
 		panic("VFS: Unable to mount root fs on %s", b);
 	}
 
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 0b504814e37..7d7a31d0dde 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -624,6 +624,28 @@ config BACKTRACE_SELF_TEST
 
 	  Say N if you are unsure.
 
+config DEBUG_BLOCK_EXT_DEVT
+        bool "Force extended block device numbers and spread them"
+	depends on DEBUG_KERNEL
+	depends on BLOCK
+	default n
+	help
+	  Conventionally, block device numbers are allocated from
+	  predetermined contiguous area.  However, extended block area
+	  may introduce non-contiguous block device numbers.  This
+	  option forces most block device numbers to be allocated from
+	  the extended space and spreads them to discover kernel or
+	  userland code paths which assume predetermined contiguous
+	  device number allocation.
+
+	  Note that turning on this debug option shuffles all the
+	  device numbers for all IDE and SCSI devices including libata
+	  ones, so root partition specified using device number
+	  directly (via rdev or root=MAJ:MIN) won't work anymore.
+	  Textual device names (root=/dev/sdXn) will continue to work.
+
+	  Say N if you are unsure.
+
 config LKDTM
 	tristate "Linux Kernel Dump Test Tool Module"
 	depends on DEBUG_KERNEL
@@ -661,10 +683,21 @@ config FAIL_PAGE_ALLOC
 
 config FAIL_MAKE_REQUEST
 	bool "Fault-injection capability for disk IO"
-	depends on FAULT_INJECTION
+	depends on FAULT_INJECTION && BLOCK
 	help
 	  Provide fault-injection capability for disk IO.
 
+config FAIL_IO_TIMEOUT
+	bool "Faul-injection capability for faking disk interrupts"
+	depends on FAULT_INJECTION && BLOCK
+	help
+	  Provide fault-injection capability on end IO handling. This
+	  will make the block layer "forget" an interrupt as configured,
+	  thus exercising the error handling.
+
+	  Only works with drivers that use the generic timeout handling,
+	  for others it wont do anything.
+
 config FAULT_INJECTION_DEBUG_FS
 	bool "Debugfs entries for fault-injection capabilities"
 	depends on FAULT_INJECTION && SYSFS && DEBUG_FS
diff --git a/lib/klist.c b/lib/klist.c
index cca37f96faa..bbdd3015c2c 100644
--- a/lib/klist.c
+++ b/lib/klist.c
@@ -37,6 +37,37 @@
 #include <linux/klist.h>
 #include <linux/module.h>
 
+/*
+ * Use the lowest bit of n_klist to mark deleted nodes and exclude
+ * dead ones from iteration.
+ */
+#define KNODE_DEAD		1LU
+#define KNODE_KLIST_MASK	~KNODE_DEAD
+
+static struct klist *knode_klist(struct klist_node *knode)
+{
+	return (struct klist *)
+		((unsigned long)knode->n_klist & KNODE_KLIST_MASK);
+}
+
+static bool knode_dead(struct klist_node *knode)
+{
+	return (unsigned long)knode->n_klist & KNODE_DEAD;
+}
+
+static void knode_set_klist(struct klist_node *knode, struct klist *klist)
+{
+	knode->n_klist = klist;
+	/* no knode deserves to start its life dead */
+	WARN_ON(knode_dead(knode));
+}
+
+static void knode_kill(struct klist_node *knode)
+{
+	/* and no knode should die twice ever either, see we're very humane */
+	WARN_ON(knode_dead(knode));
+	*(unsigned long *)&knode->n_klist |= KNODE_DEAD;
+}
 
 /**
  * klist_init - Initialize a klist structure.
@@ -79,7 +110,7 @@ static void klist_node_init(struct klist *k, struct klist_node *n)
 	INIT_LIST_HEAD(&n->n_node);
 	init_completion(&n->n_removed);
 	kref_init(&n->n_ref);
-	n->n_klist = k;
+	knode_set_klist(n, k);
 	if (k->get)
 		k->get(n);
 }
@@ -115,7 +146,7 @@ EXPORT_SYMBOL_GPL(klist_add_tail);
  */
 void klist_add_after(struct klist_node *n, struct klist_node *pos)
 {
-	struct klist *k = pos->n_klist;
+	struct klist *k = knode_klist(pos);
 
 	klist_node_init(k, n);
 	spin_lock(&k->k_lock);
@@ -131,7 +162,7 @@ EXPORT_SYMBOL_GPL(klist_add_after);
  */
 void klist_add_before(struct klist_node *n, struct klist_node *pos)
 {
-	struct klist *k = pos->n_klist;
+	struct klist *k = knode_klist(pos);
 
 	klist_node_init(k, n);
 	spin_lock(&k->k_lock);
@@ -144,9 +175,10 @@ static void klist_release(struct kref *kref)
 {
 	struct klist_node *n = container_of(kref, struct klist_node, n_ref);
 
+	WARN_ON(!knode_dead(n));
 	list_del(&n->n_node);
 	complete(&n->n_removed);
-	n->n_klist = NULL;
+	knode_set_klist(n, NULL);
 }
 
 static int klist_dec_and_del(struct klist_node *n)
@@ -154,22 +186,29 @@ static int klist_dec_and_del(struct klist_node *n)
 	return kref_put(&n->n_ref, klist_release);
 }
 
-/**
- * klist_del - Decrement the reference count of node and try to remove.
- * @n: node we're deleting.
- */
-void klist_del(struct klist_node *n)
+static void klist_put(struct klist_node *n, bool kill)
 {
-	struct klist *k = n->n_klist;
+	struct klist *k = knode_klist(n);
 	void (*put)(struct klist_node *) = k->put;
 
 	spin_lock(&k->k_lock);
+	if (kill)
+		knode_kill(n);
 	if (!klist_dec_and_del(n))
 		put = NULL;
 	spin_unlock(&k->k_lock);
 	if (put)
 		put(n);
 }
+
+/**
+ * klist_del - Decrement the reference count of node and try to remove.
+ * @n: node we're deleting.
+ */
+void klist_del(struct klist_node *n)
+{
+	klist_put(n, true);
+}
 EXPORT_SYMBOL_GPL(klist_del);
 
 /**
@@ -206,7 +245,6 @@ void klist_iter_init_node(struct klist *k, struct klist_iter *i,
 			  struct klist_node *n)
 {
 	i->i_klist = k;
-	i->i_head = &k->k_list;
 	i->i_cur = n;
 	if (n)
 		kref_get(&n->n_ref);
@@ -237,7 +275,7 @@ EXPORT_SYMBOL_GPL(klist_iter_init);
 void klist_iter_exit(struct klist_iter *i)
 {
 	if (i->i_cur) {
-		klist_del(i->i_cur);
+		klist_put(i->i_cur, false);
 		i->i_cur = NULL;
 	}
 }
@@ -258,27 +296,33 @@ static struct klist_node *to_klist_node(struct list_head *n)
  */
 struct klist_node *klist_next(struct klist_iter *i)
 {
-	struct list_head *next;
-	struct klist_node *lnode = i->i_cur;
-	struct klist_node *knode = NULL;
 	void (*put)(struct klist_node *) = i->i_klist->put;
+	struct klist_node *last = i->i_cur;
+	struct klist_node *next;
 
 	spin_lock(&i->i_klist->k_lock);
-	if (lnode) {
-		next = lnode->n_node.next;
-		if (!klist_dec_and_del(lnode))
+
+	if (last) {
+		next = to_klist_node(last->n_node.next);
+		if (!klist_dec_and_del(last))
 			put = NULL;
 	} else
-		next = i->i_head->next;
+		next = to_klist_node(i->i_klist->k_list.next);
 
-	if (next != i->i_head) {
-		knode = to_klist_node(next);
-		kref_get(&knode->n_ref);
+	i->i_cur = NULL;
+	while (next != to_klist_node(&i->i_klist->k_list)) {
+		if (likely(!knode_dead(next))) {
+			kref_get(&next->n_ref);
+			i->i_cur = next;
+			break;
+		}
+		next = to_klist_node(next->n_node.next);
 	}
-	i->i_cur = knode;
+
 	spin_unlock(&i->i_klist->k_lock);
-	if (put && lnode)
-		put(lnode);
-	return knode;
+
+	if (put && last)
+		put(last);
+	return i->i_cur;
 }
 EXPORT_SYMBOL_GPL(klist_next);
diff --git a/mm/bounce.c b/mm/bounce.c
index b6d2d0f1019..06722c40305 100644
--- a/mm/bounce.c
+++ b/mm/bounce.c
@@ -267,7 +267,7 @@ void blk_queue_bounce(struct request_queue *q, struct bio **bio_orig)
 	/*
 	 * Data-less bio, nothing to bounce
 	 */
-	if (bio_empty_barrier(*bio_orig))
+	if (!bio_has_data(*bio_orig))
 		return;
 
 	/*