Merge branch 'master' into for-next

author: Jiri Kosina <jkosina@suse.cz> 2010-06-16 18:08:13 +0200
committer: Jiri Kosina <jkosina@suse.cz> 2010-06-16 18:08:13 +0200
commit: f1bbbb6912662b9f6070c5bfc4ca9eb1f06a9d5b (patch)
tree: c2c130a74be25b0b2dff992e1a195e2728bdaadd /drivers/block
parent: fd0961ff67727482bb20ca7e8ea97b83e9de2ddb (diff)
parent: 7e27d6e778cd87b6f2415515d7127eba53fe5d02 (diff)
18 files changed, 1040 insertions, 539 deletions
diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig
index 77bfce52e9c..de277689da6 100644
--- a/drivers/block/Kconfig
+++ b/drivers/block/Kconfig
@@ -76,6 +76,17 @@ config BLK_DEV_XD
 
 	  It's pretty unlikely that you have one of these: say N.
 
+config GDROM
+	tristate "SEGA Dreamcast GD-ROM drive"
+	depends on SH_DREAMCAST
+	help
+	  A standard SEGA Dreamcast comes with a modified CD ROM drive called a
+	  "GD-ROM" by SEGA to signify it is capable of reading special disks
+	  with up to 1 GB of data. This drive will also read standard CD ROM
+	  disks. Select this option to access any disks in your GD ROM drive.
+	  Most users will want to say "Y" here.
+	  You can also build this as a module which will be called gdrom.
+
 config PARIDE
 	tristate "Parallel port IDE device support"
 	depends on PARPORT_PC
@@ -103,17 +114,6 @@ config PARIDE
 	  "MicroSolutions backpack protocol", "DataStor Commuter protocol"
 	  etc.).
 
-config GDROM
-	tristate "SEGA Dreamcast GD-ROM drive"
-	depends on SH_DREAMCAST
-	help
-	  A standard SEGA Dreamcast comes with a modified CD ROM drive called a
-	  "GD-ROM" by SEGA to signify it is capable of reading special disks
-	  with up to 1 GB of data. This drive will also read standard CD ROM
-	  disks. Select this option to access any disks in your GD ROM drive.
-	  Most users will want to say "Y" here.
-	  You can also build this as a module which will be called gdrom.
-
 source "drivers/block/paride/Kconfig"
 
 config BLK_CPQ_DA
diff --git a/drivers/block/brd.c b/drivers/block/brd.c
index 6081e81d573..f1bf79d9bc0 100644
--- a/drivers/block/brd.c
+++ b/drivers/block/brd.c
@@ -133,6 +133,28 @@ static struct page *brd_insert_page(struct brd_device *brd, sector_t sector)
 	return page;
 }
 
+static void brd_free_page(struct brd_device *brd, sector_t sector)
+{
+	struct page *page;
+	pgoff_t idx;
+
+	spin_lock(&brd->brd_lock);
+	idx = sector >> PAGE_SECTORS_SHIFT;
+	page = radix_tree_delete(&brd->brd_pages, idx);
+	spin_unlock(&brd->brd_lock);
+	if (page)
+		__free_page(page);
+}
+
+static void brd_zero_page(struct brd_device *brd, sector_t sector)
+{
+	struct page *page;
+
+	page = brd_lookup_page(brd, sector);
+	if (page)
+		clear_highpage(page);
+}
+
 /*
  * Free all backing store pages and radix tree. This must only be called when
  * there are no other users of the device.
@@ -189,6 +211,24 @@ static int copy_to_brd_setup(struct brd_device *brd, sector_t sector, size_t n)
 	return 0;
 }
 
+static void discard_from_brd(struct brd_device *brd,
+			sector_t sector, size_t n)
+{
+	while (n >= PAGE_SIZE) {
+		/*
+		 * Don't want to actually discard pages here because
+		 * re-allocating the pages can result in writeback
+		 * deadlocks under heavy load.
+		 */
+		if (0)
+			brd_free_page(brd, sector);
+		else
+			brd_zero_page(brd, sector);
+		sector += PAGE_SIZE >> SECTOR_SHIFT;
+		n -= PAGE_SIZE;
+	}
+}
+
 /*
  * Copy n bytes from src to the brd starting at sector. Does not sleep.
  */
@@ -300,6 +340,12 @@ static int brd_make_request(struct request_queue *q, struct bio *bio)
 						get_capacity(bdev->bd_disk))
 		goto out;
 
+	if (unlikely(bio_rw_flagged(bio, BIO_RW_DISCARD))) {
+		err = 0;
+		discard_from_brd(brd, sector, bio->bi_size);
+		goto out;
+	}
+
 	rw = bio_rw(bio);
 	if (rw == READA)
 		rw = READ;
@@ -320,7 +366,7 @@ out:
 }
 
 #ifdef CONFIG_BLK_DEV_XIP
-static int brd_direct_access (struct block_device *bdev, sector_t sector,
+static int brd_direct_access(struct block_device *bdev, sector_t sector,
 			void **kaddr, unsigned long *pfn)
 {
 	struct brd_device *brd = bdev->bd_disk->private_data;
@@ -437,6 +483,11 @@ static struct brd_device *brd_alloc(int i)
 	blk_queue_max_hw_sectors(brd->brd_queue, 1024);
 	blk_queue_bounce_limit(brd->brd_queue, BLK_BOUNCE_ANY);
 
+	brd->brd_queue->limits.discard_granularity = PAGE_SIZE;
+	brd->brd_queue->limits.max_discard_sectors = UINT_MAX;
+	brd->brd_queue->limits.discard_zeroes_data = 1;
+	queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, brd->brd_queue);
+
 	disk = brd->brd_disk = alloc_disk(1 << part_shift);
 	if (!disk)
 		goto out_free_queue;
diff --git a/drivers/block/cciss_scsi.c b/drivers/block/cciss_scsi.c
index e1d0e2cfec7..3381505c8a6 100644
--- a/drivers/block/cciss_scsi.c
+++ b/drivers/block/cciss_scsi.c
@@ -188,11 +188,11 @@ scsi_cmd_free(ctlr_info_t *h, CommandList_struct *cmd)
 
 	sa = h->scsi_ctlr;
 	stk = &sa->cmd_stack; 
+	stk->top++;
 	if (stk->top >= CMD_STACK_SIZE) {
 		printk("cciss: scsi_cmd_free called too many times.\n");
 		BUG();
 	}
-	stk->top++;
 	stk->elem[stk->top] = (struct cciss_scsi_cmd_stack_elem_t *) cmd;
 }
 
diff --git a/drivers/block/drbd/drbd_bitmap.c b/drivers/block/drbd/drbd_bitmap.c
index 3390716898d..e3f88d6e141 100644
--- a/drivers/block/drbd/drbd_bitmap.c
+++ b/drivers/block/drbd/drbd_bitmap.c
@@ -84,6 +84,9 @@ struct drbd_bitmap {
 #define BM_MD_IO_ERROR  1
 #define BM_P_VMALLOCED  2
 
+static int __bm_change_bits_to(struct drbd_conf *mdev, const unsigned long s,
+			       unsigned long e, int val, const enum km_type km);
+
 static int bm_is_locked(struct drbd_bitmap *b)
 {
 	return test_bit(BM_LOCKED, &b->bm_flags);
@@ -441,7 +444,7 @@ static void bm_memset(struct drbd_bitmap *b, size_t offset, int c, size_t len)
  * In case this is actually a resize, we copy the old bitmap into the new one.
  * Otherwise, the bitmap is initialized to all bits set.
  */
-int drbd_bm_resize(struct drbd_conf *mdev, sector_t capacity)
+int drbd_bm_resize(struct drbd_conf *mdev, sector_t capacity, int set_new_bits)
 {
 	struct drbd_bitmap *b = mdev->bitmap;
 	unsigned long bits, words, owords, obits, *p_addr, *bm;
@@ -516,7 +519,7 @@ int drbd_bm_resize(struct drbd_conf *mdev, sector_t capacity)
 	obits  = b->bm_bits;
 
 	growing = bits > obits;
-	if (opages)
+	if (opages && growing && set_new_bits)
 		bm_set_surplus(b);
 
 	b->bm_pages = npages;
@@ -526,8 +529,12 @@ int drbd_bm_resize(struct drbd_conf *mdev, sector_t capacity)
 	b->bm_dev_capacity = capacity;
 
 	if (growing) {
-		bm_memset(b, owords, 0xff, words-owords);
-		b->bm_set += bits - obits;
+		if (set_new_bits) {
+			bm_memset(b, owords, 0xff, words-owords);
+			b->bm_set += bits - obits;
+		} else
+			bm_memset(b, owords, 0x00, words-owords);
+
 	}
 
 	if (want < have) {
@@ -773,7 +780,7 @@ static void bm_page_io_async(struct drbd_conf *mdev, struct drbd_bitmap *b, int
 	/* nothing to do, on disk == in memory */
 # define bm_cpu_to_lel(x) ((void)0)
 # else
-void bm_cpu_to_lel(struct drbd_bitmap *b)
+static void bm_cpu_to_lel(struct drbd_bitmap *b)
 {
 	/* need to cpu_to_lel all the pages ...
 	 * this may be optimized by using
@@ -1015,7 +1022,7 @@ unsigned long _drbd_bm_find_next_zero(struct drbd_conf *mdev, unsigned long bm_f
  * wants bitnr, not sector.
  * expected to be called for only a few bits (e - s about BITS_PER_LONG).
  * Must hold bitmap lock already. */
-int __bm_change_bits_to(struct drbd_conf *mdev, const unsigned long s,
+static int __bm_change_bits_to(struct drbd_conf *mdev, const unsigned long s,
 	unsigned long e, int val, const enum km_type km)
 {
 	struct drbd_bitmap *b = mdev->bitmap;
@@ -1053,7 +1060,7 @@ int __bm_change_bits_to(struct drbd_conf *mdev, const unsigned long s,
  * for val != 0, we change 0 -> 1, return code positive
  * for val == 0, we change 1 -> 0, return code negative
  * wants bitnr, not sector */
-int bm_change_bits_to(struct drbd_conf *mdev, const unsigned long s,
+static int bm_change_bits_to(struct drbd_conf *mdev, const unsigned long s,
 	const unsigned long e, int val)
 {
 	unsigned long flags;
diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index e5e86a78182..485ed8c7d62 100644
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -132,6 +132,7 @@ enum {
 	DRBD_FAULT_DT_RA = 6,	/* data read ahead */
 	DRBD_FAULT_BM_ALLOC = 7,	/* bitmap allocation */
 	DRBD_FAULT_AL_EE = 8,	/* alloc ee */
+	DRBD_FAULT_RECEIVE = 9, /* Changes some bytes upon receiving a [rs]data block */
 
 	DRBD_FAULT_MAX,
 };
@@ -208,8 +209,11 @@ enum drbd_packets {
 	P_RS_IS_IN_SYNC	      = 0x22, /* meta socket */
 	P_SYNC_PARAM89	      = 0x23, /* data socket, protocol version 89 replacement for P_SYNC_PARAM */
 	P_COMPRESSED_BITMAP   = 0x24, /* compressed or otherwise encoded bitmap transfer */
+	/* P_CKPT_FENCE_REQ      = 0x25, * currently reserved for protocol D */
+	/* P_CKPT_DISABLE_REQ    = 0x26, * currently reserved for protocol D */
+	P_DELAY_PROBE         = 0x27, /* is used on BOTH sockets */
 
-	P_MAX_CMD	      = 0x25,
+	P_MAX_CMD	      = 0x28,
 	P_MAY_IGNORE	      = 0x100, /* Flag to test if (cmd > P_MAY_IGNORE) ... */
 	P_MAX_OPT_CMD	      = 0x101,
 
@@ -264,6 +268,7 @@ static inline const char *cmdname(enum drbd_packets cmd)
 		[P_CSUM_RS_REQUEST]     = "CsumRSRequest",
 		[P_RS_IS_IN_SYNC]	= "CsumRSIsInSync",
 		[P_COMPRESSED_BITMAP]   = "CBitmap",
+		[P_DELAY_PROBE]         = "DelayProbe",
 		[P_MAX_CMD]	        = NULL,
 	};
 
@@ -481,7 +486,8 @@ struct p_sizes {
 	u64	    u_size;  /* user requested size */
 	u64	    c_size;  /* current exported size */
 	u32	    max_segment_size;  /* Maximal size of a BIO */
-	u32	    queue_order_type;
+	u16	    queue_order_type;  /* not yet implemented in DRBD*/
+	u16	    dds_flags; /* use enum dds_flags here. */
 } __packed;
 
 struct p_state {
@@ -538,6 +544,18 @@ struct p_compressed_bm {
 	u8 code[0];
 } __packed;
 
+struct p_delay_probe {
+	struct p_header head;
+	u32	seq_num; /* sequence number to match the two probe packets */
+	u32	offset;	 /* usecs the probe got sent after the reference time point */
+} __packed;
+
+struct delay_probe {
+	struct list_head list;
+	unsigned int seq_num;
+	struct timeval time;
+};
+
 /* DCBP: Drbd Compressed Bitmap Packet ... */
 static inline enum drbd_bitmap_code
 DCBP_get_code(struct p_compressed_bm *p)
@@ -722,22 +740,6 @@ enum epoch_event {
 	EV_CLEANUP = 32, /* used as flag */
 };
 
-struct drbd_epoch_entry {
-	struct drbd_work    w;
-	struct drbd_conf *mdev;
-	struct bio *private_bio;
-	struct hlist_node colision;
-	sector_t sector;
-	unsigned int size;
-	struct drbd_epoch *epoch;
-
-	/* up to here, the struct layout is identical to drbd_request;
-	 * we might be able to use that to our advantage...  */
-
-	unsigned int flags;
-	u64    block_id;
-};
-
 struct drbd_wq_barrier {
 	struct drbd_work w;
 	struct completion done;
@@ -748,17 +750,49 @@ struct digest_info {
 	void *digest;
 };
 
-/* ee flag bits */
+struct drbd_epoch_entry {
+	struct drbd_work w;
+	struct hlist_node colision;
+	struct drbd_epoch *epoch;
+	struct drbd_conf *mdev;
+	struct page *pages;
+	atomic_t pending_bios;
+	unsigned int size;
+	/* see comments on ee flag bits below */
+	unsigned long flags;
+	sector_t sector;
+	u64 block_id;
+};
+
+/* ee flag bits.
+ * While corresponding bios are in flight, the only modification will be
+ * set_bit WAS_ERROR, which has to be atomic.
+ * If no bios are in flight yet, or all have been completed,
+ * non-atomic modification to ee->flags is ok.
+ */
 enum {
 	__EE_CALL_AL_COMPLETE_IO,
-	__EE_CONFLICT_PENDING,
 	__EE_MAY_SET_IN_SYNC,
+
+	/* This epoch entry closes an epoch using a barrier.
+	 * On sucessful completion, the epoch is released,
+	 * and the P_BARRIER_ACK send. */
 	__EE_IS_BARRIER,
+
+	/* In case a barrier failed,
+	 * we need to resubmit without the barrier flag. */
+	__EE_RESUBMITTED,
+
+	/* we may have several bios per epoch entry.
+	 * if any of those fail, we set this flag atomically
+	 * from the endio callback */
+	__EE_WAS_ERROR,
 };
 #define EE_CALL_AL_COMPLETE_IO (1<<__EE_CALL_AL_COMPLETE_IO)
-#define EE_CONFLICT_PENDING    (1<<__EE_CONFLICT_PENDING)
 #define EE_MAY_SET_IN_SYNC     (1<<__EE_MAY_SET_IN_SYNC)
 #define EE_IS_BARRIER          (1<<__EE_IS_BARRIER)
+#define	EE_RESUBMITTED         (1<<__EE_RESUBMITTED)
+#define EE_WAS_ERROR           (1<<__EE_WAS_ERROR)
 
 /* global flag bits */
 enum {
@@ -908,9 +942,11 @@ struct drbd_conf {
 	unsigned int ko_count;
 	struct drbd_work  resync_work,
 			  unplug_work,
-			  md_sync_work;
+			  md_sync_work,
+			  delay_probe_work;
 	struct timer_list resync_timer;
 	struct timer_list md_sync_timer;
+	struct timer_list delay_probe_timer;
 
 	/* Used after attach while negotiating new disk state. */
 	union drbd_state new_state_tmp;
@@ -1026,6 +1062,12 @@ struct drbd_conf {
 	u64 ed_uuid; /* UUID of the exposed data */
 	struct mutex state_mutex;
 	char congestion_reason;  /* Why we where congested... */
+	struct list_head delay_probes; /* protected by peer_seq_lock */
+	int data_delay;   /* Delay of packets on the data-sock behind meta-sock */
+	unsigned int delay_seq; /* To generate sequence numbers of delay probes */
+	struct timeval dps_time; /* delay-probes-start-time */
+	unsigned int dp_volume_last;  /* send_cnt of last delay probe */
+	int c_sync_rate; /* current resync rate after delay_probe magic */
 };
 
 static inline struct drbd_conf *minor_to_mdev(unsigned int minor)
@@ -1081,6 +1123,11 @@ enum chg_state_flags {
 	CS_ORDERED      = CS_WAIT_COMPLETE + CS_SERIALIZE,
 };
 
+enum dds_flags {
+	DDSF_FORCED    = 1,
+	DDSF_NO_RESYNC = 2, /* Do not run a resync for the new space */
+};
+
 extern void drbd_init_set_defaults(struct drbd_conf *mdev);
 extern int drbd_change_state(struct drbd_conf *mdev, enum chg_state_flags f,
 			union drbd_state mask, union drbd_state val);
@@ -1113,7 +1160,7 @@ extern int drbd_send_protocol(struct drbd_conf *mdev);
 extern int drbd_send_uuids(struct drbd_conf *mdev);
 extern int drbd_send_uuids_skip_initial_sync(struct drbd_conf *mdev);
 extern int drbd_send_sync_uuid(struct drbd_conf *mdev, u64 val);
-extern int drbd_send_sizes(struct drbd_conf *mdev, int trigger_reply);
+extern int drbd_send_sizes(struct drbd_conf *mdev, int trigger_reply, enum dds_flags flags);
 extern int _drbd_send_state(struct drbd_conf *mdev);
 extern int drbd_send_state(struct drbd_conf *mdev);
 extern int _drbd_send_cmd(struct drbd_conf *mdev, struct socket *sock,
@@ -1311,7 +1358,7 @@ struct bm_extent {
 #define APP_R_HSIZE 15
 
 extern int  drbd_bm_init(struct drbd_conf *mdev);
-extern int  drbd_bm_resize(struct drbd_conf *mdev, sector_t sectors);
+extern int  drbd_bm_resize(struct drbd_conf *mdev, sector_t sectors, int set_new_bits);
 extern void drbd_bm_cleanup(struct drbd_conf *mdev);
 extern void drbd_bm_set_all(struct drbd_conf *mdev);
 extern void drbd_bm_clear_all(struct drbd_conf *mdev);
@@ -1383,7 +1430,7 @@ extern void drbd_resume_io(struct drbd_conf *mdev);
 extern char *ppsize(char *buf, unsigned long long size);
 extern sector_t drbd_new_dev_size(struct drbd_conf *, struct drbd_backing_dev *, int);
 enum determine_dev_size { dev_size_error = -1, unchanged = 0, shrunk = 1, grew = 2 };
-extern enum determine_dev_size drbd_determin_dev_size(struct drbd_conf *, int force) __must_hold(local);
+extern enum determine_dev_size drbd_determin_dev_size(struct drbd_conf *, enum dds_flags) __must_hold(local);
 extern void resync_after_online_grow(struct drbd_conf *);
 extern void drbd_setup_queue_param(struct drbd_conf *mdev, unsigned int) __must_hold(local);
 extern int drbd_set_role(struct drbd_conf *mdev, enum drbd_role new_role,
@@ -1414,7 +1461,8 @@ static inline void ov_oos_print(struct drbd_conf *mdev)
 }
 
 
-extern void drbd_csum(struct drbd_conf *, struct crypto_hash *, struct bio *, void *);
+extern void drbd_csum_bio(struct drbd_conf *, struct crypto_hash *, struct bio *, void *);
+extern void drbd_csum_ee(struct drbd_conf *, struct crypto_hash *, struct drbd_epoch_entry *, void *);
 /* worker callbacks */
 extern int w_req_cancel_conflict(struct drbd_conf *, struct drbd_work *, int);
 extern int w_read_retry_remote(struct drbd_conf *, struct drbd_work *, int);
@@ -1426,7 +1474,6 @@ extern int w_e_end_ov_req(struct drbd_conf *, struct drbd_work *, int);
 extern int w_ov_finished(struct drbd_conf *, struct drbd_work *, int);
 extern int w_resync_inactive(struct drbd_conf *, struct drbd_work *, int);
 extern int w_resume_next_sg(struct drbd_conf *, struct drbd_work *, int);
-extern int w_io_error(struct drbd_conf *, struct drbd_work *, int);
 extern int w_send_write_hint(struct drbd_conf *, struct drbd_work *, int);
 extern int w_make_resync_request(struct drbd_conf *, struct drbd_work *, int);
 extern int w_send_dblock(struct drbd_conf *, struct drbd_work *, int);
@@ -1438,6 +1485,8 @@ extern int w_e_reissue(struct drbd_conf *, struct drbd_work *, int);
 extern void resync_timer_fn(unsigned long data);
 
 /* drbd_receiver.c */
+extern int drbd_submit_ee(struct drbd_conf *mdev, struct drbd_epoch_entry *e,
+		const unsigned rw, const int fault_type);
 extern int drbd_release_ee(struct drbd_conf *mdev, struct list_head *list);
 extern struct drbd_epoch_entry *drbd_alloc_ee(struct drbd_conf *mdev,
 					    u64 id,
@@ -1490,7 +1539,7 @@ static inline void drbd_tcp_nodelay(struct socket *sock)
 
 static inline void drbd_tcp_quickack(struct socket *sock)
 {
-	int __user val = 1;
+	int __user val = 2;
 	(void) drbd_setsockopt(sock, SOL_TCP, TCP_QUICKACK,
 			(char __user *)&val, sizeof(val));
 }
@@ -1593,6 +1642,41 @@ void drbd_bcast_ee(struct drbd_conf *mdev,
  * inline helper functions
  *************************/
 
+/* see also page_chain_add and friends in drbd_receiver.c */
+static inline struct page *page_chain_next(struct page *page)
+{
+	return (struct page *)page_private(page);
+}
+#define page_chain_for_each(page) \
+	for (; page && ({ prefetch(page_chain_next(page)); 1; }); \
+			page = page_chain_next(page))
+#define page_chain_for_each_safe(page, n) \
+	for (; page && ({ n = page_chain_next(page); 1; }); page = n)
+
+static inline int drbd_bio_has_active_page(struct bio *bio)
+{
+	struct bio_vec *bvec;
+	int i;
+
+	__bio_for_each_segment(bvec, bio, i, 0) {
+		if (page_count(bvec->bv_page) > 1)
+			return 1;
+	}
+
+	return 0;
+}
+
+static inline int drbd_ee_has_active_page(struct drbd_epoch_entry *e)
+{
+	struct page *page = e->pages;
+	page_chain_for_each(page) {
+		if (page_count(page) > 1)
+			return 1;
+	}
+	return 0;
+}
+
+
 static inline void drbd_state_lock(struct drbd_conf *mdev)
 {
 	wait_event(mdev->misc_wait,
@@ -1641,7 +1725,7 @@ static inline void __drbd_chk_io_error_(struct drbd_conf *mdev, int forcedetach,
 	switch (mdev->ldev->dc.on_io_error) {
 	case EP_PASS_ON:
 		if (!forcedetach) {
-			if (printk_ratelimit())
+			if (__ratelimit(&drbd_ratelimit_state))
 				dev_err(DEV, "Local IO failed in %s."
 					     "Passing error on...\n", where);
 			break;
@@ -2138,7 +2222,7 @@ static inline int __inc_ap_bio_cond(struct drbd_conf *mdev)
 /* I'd like to use wait_event_lock_irq,
  * but I'm not sure when it got introduced,
  * and not sure when it has 3 or 4 arguments */
-static inline void inc_ap_bio(struct drbd_conf *mdev, int one_or_two)
+static inline void inc_ap_bio(struct drbd_conf *mdev, int count)
 {
 	/* compare with after_state_ch,
 	 * os.conn != C_WF_BITMAP_S && ns.conn == C_WF_BITMAP_S */
@@ -2160,7 +2244,7 @@ static inline void inc_ap_bio(struct drbd_conf *mdev, int one_or_two)
 		finish_wait(&mdev->misc_wait, &wait);
 		spin_lock_irq(&mdev->req_lock);
 	}
-	atomic_add(one_or_two, &mdev->ap_bio_cnt);
+	atomic_add(count, &mdev->ap_bio_cnt);
 	spin_unlock_irq(&mdev->req_lock);
 }
 
@@ -2251,7 +2335,8 @@ static inline void drbd_md_flush(struct drbd_conf *mdev)
 	if (test_bit(MD_NO_BARRIER, &mdev->flags))
 		return;
 
-	r = blkdev_issue_flush(mdev->ldev->md_bdev, NULL);
+	r = blkdev_issue_flush(mdev->ldev->md_bdev, GFP_KERNEL, NULL,
+			BLKDEV_IFL_WAIT);
 	if (r) {
 		set_bit(MD_NO_BARRIER, &mdev->flags);
 		dev_err(DEV, "meta data flush failed with status %d, disabling md-flushes\n", r);
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 93d1f9b469d..6b077f93acc 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -684,6 +684,9 @@ static int is_valid_state(struct drbd_conf *mdev, union drbd_state ns)
 	else if (ns.conn > C_CONNECTED && ns.pdsk < D_INCONSISTENT)
 		rv = SS_NO_REMOTE_DISK;
 
+	else if (ns.conn > C_CONNECTED && ns.disk < D_UP_TO_DATE && ns.pdsk < D_UP_TO_DATE)
+		rv = SS_NO_UP_TO_DATE_DISK;
+
 	else if ((ns.conn == C_CONNECTED ||
 		  ns.conn == C_WF_BITMAP_S ||
 		  ns.conn == C_SYNC_SOURCE ||
@@ -840,7 +843,12 @@ static union drbd_state sanitize_state(struct drbd_conf *mdev, union drbd_state
 			break;
 		case C_WF_BITMAP_S:
 		case C_PAUSED_SYNC_S:
-			ns.pdsk = D_OUTDATED;
+			/* remap any consistent state to D_OUTDATED,
+			 * but disallow "upgrade" of not even consistent states.
+			 */
+			ns.pdsk =
+				(D_DISKLESS < os.pdsk && os.pdsk < D_OUTDATED)
+				? os.pdsk : D_OUTDATED;
 			break;
 		case C_SYNC_SOURCE:
 			ns.pdsk = D_INCONSISTENT;
@@ -1205,8 +1213,6 @@ static void after_state_ch(struct drbd_conf *mdev, union drbd_state os,
 	&&  (ns.pdsk < D_INCONSISTENT ||
 	     ns.pdsk == D_UNKNOWN ||
 	     ns.pdsk == D_OUTDATED)) {
-		kfree(mdev->p_uuid);
-		mdev->p_uuid = NULL;
 		if (get_ldev(mdev)) {
 			if ((ns.role == R_PRIMARY || ns.peer == R_PRIMARY) &&
 			    mdev->ldev->md.uuid[UI_BITMAP] == 0 && ns.disk >= D_UP_TO_DATE) {
@@ -1232,7 +1238,7 @@ static void after_state_ch(struct drbd_conf *mdev, union drbd_state os,
 	    os.disk == D_ATTACHING && ns.disk == D_NEGOTIATING) {
 		kfree(mdev->p_uuid); /* We expect to receive up-to-date UUIDs soon. */
 		mdev->p_uuid = NULL; /* ...to not use the old ones in the mean time */
-		drbd_send_sizes(mdev, 0);  /* to start sync... */
+		drbd_send_sizes(mdev, 0, 0);  /* to start sync... */
 		drbd_send_uuids(mdev);
 		drbd_send_state(mdev);
 	}
@@ -1755,7 +1761,7 @@ int drbd_send_sync_uuid(struct drbd_conf *mdev, u64 val)
 			     (struct p_header *)&p, sizeof(p));
 }
 
-int drbd_send_sizes(struct drbd_conf *mdev, int trigger_reply)
+int drbd_send_sizes(struct drbd_conf *mdev, int trigger_reply, enum dds_flags flags)
 {
 	struct p_sizes p;
 	sector_t d_size, u_size;
@@ -1767,7 +1773,6 @@ int drbd_send_sizes(struct drbd_conf *mdev, int trigger_reply)
 		d_size = drbd_get_max_capacity(mdev->ldev);
 		u_size = mdev->ldev->dc.disk_size;
 		q_order_type = drbd_queue_order_type(mdev);
-		p.queue_order_type = cpu_to_be32(drbd_queue_order_type(mdev));
 		put_ldev(mdev);
 	} else {
 		d_size = 0;
@@ -1779,7 +1784,8 @@ int drbd_send_sizes(struct drbd_conf *mdev, int trigger_reply)
 	p.u_size = cpu_to_be64(u_size);
 	p.c_size = cpu_to_be64(trigger_reply ? 0 : drbd_get_capacity(mdev->this_bdev));
 	p.max_segment_size = cpu_to_be32(queue_max_segment_size(mdev->rq_queue));
-	p.queue_order_type = cpu_to_be32(q_order_type);
+	p.queue_order_type = cpu_to_be16(q_order_type);
+	p.dds_flags = cpu_to_be16(flags);
 
 	ok = drbd_send_cmd(mdev, USE_DATA_SOCKET, P_SIZES,
 			   (struct p_header *)&p, sizeof(p));
@@ -2180,6 +2186,43 @@ int drbd_send_ov_request(struct drbd_conf *mdev, sector_t sector, int size)
 	return ok;
 }
 
+static int drbd_send_delay_probe(struct drbd_conf *mdev, struct drbd_socket *ds)
+{
+	struct p_delay_probe dp;
+	int offset, ok = 0;
+	struct timeval now;
+
+	mutex_lock(&ds->mutex);
+	if (likely(ds->socket)) {
+		do_gettimeofday(&now);
+		offset = now.tv_usec - mdev->dps_time.tv_usec +
+			 (now.tv_sec - mdev->dps_time.tv_sec) * 1000000;
+		dp.seq_num  = cpu_to_be32(mdev->delay_seq);
+		dp.offset   = cpu_to_be32(offset);
+
+		ok = _drbd_send_cmd(mdev, ds->socket, P_DELAY_PROBE,
+				    (struct p_header *)&dp, sizeof(dp), 0);
+	}
+	mutex_unlock(&ds->mutex);
+
+	return ok;
+}
+
+static int drbd_send_delay_probes(struct drbd_conf *mdev)
+{
+	int ok;
+
+	mdev->delay_seq++;
+	do_gettimeofday(&mdev->dps_time);
+	ok = drbd_send_delay_probe(mdev, &mdev->meta);
+	ok = ok && drbd_send_delay_probe(mdev, &mdev->data);
+
+	mdev->dp_volume_last = mdev->send_cnt;
+	mod_timer(&mdev->delay_probe_timer, jiffies + mdev->sync_conf.dp_interval * HZ / 10);
+
+	return ok;
+}
+
 /* called on sndtimeo
  * returns FALSE if we should retry,
  * TRUE if we think connection is dead
@@ -2229,9 +2272,9 @@ static int we_should_drop_the_connection(struct drbd_conf *mdev, struct socket *
  * with page_count == 0 or PageSlab.
  */
 static int _drbd_no_send_page(struct drbd_conf *mdev, struct page *page,
-		   int offset, size_t size)
+		   int offset, size_t size, unsigned msg_flags)
 {
-	int sent = drbd_send(mdev, mdev->data.socket, kmap(page) + offset, size, 0);
+	int sent = drbd_send(mdev, mdev->data.socket, kmap(page) + offset, size, msg_flags);
 	kunmap(page);
 	if (sent == size)
 		mdev->send_cnt += size>>9;
@@ -2239,7 +2282,7 @@ static int _drbd_no_send_page(struct drbd_conf *mdev, struct page *page,
 }
 
 static int _drbd_send_page(struct drbd_conf *mdev, struct page *page,
-		    int offset, size_t size)
+		    int offset, size_t size, unsigned msg_flags)
 {
 	mm_segment_t oldfs = get_fs();
 	int sent, ok;
@@ -2252,14 +2295,15 @@ static int _drbd_send_page(struct drbd_conf *mdev, struct page *page,
 	 * __page_cache_release a page that would actually still be referenced
 	 * by someone, leading to some obscure delayed Oops somewhere else. */
 	if (disable_sendpage || (page_count(page) < 1) || PageSlab(page))
-		return _drbd_no_send_page(mdev, page, offset, size);
+		return _drbd_no_send_page(mdev, page, offset, size, msg_flags);
 
+	msg_flags |= MSG_NOSIGNAL;
 	drbd_update_congested(mdev);
 	set_fs(KERNEL_DS);
 	do {
 		sent = mdev->data.socket->ops->sendpage(mdev->data.socket, page,
 							offset, len,
-							MSG_NOSIGNAL);
+							msg_flags);
 		if (sent == -EAGAIN) {
 			if (we_should_drop_the_connection(mdev,
 							  mdev->data.socket))
@@ -2288,9 +2332,11 @@ static int _drbd_send_bio(struct drbd_conf *mdev, struct bio *bio)
 {
 	struct bio_vec *bvec;
 	int i;
+	/* hint all but last page with MSG_MORE */
 	__bio_for_each_segment(bvec, bio, i, 0) {
 		if (!_drbd_no_send_page(mdev, bvec->bv_page,
-				     bvec->bv_offset, bvec->bv_len))
+				     bvec->bv_offset, bvec->bv_len,
+				     i == bio->bi_vcnt -1 ? 0 : MSG_MORE))
 			return 0;
 	}
 	return 1;
@@ -2300,15 +2346,56 @@ static int _drbd_send_zc_bio(struct drbd_conf *mdev, struct bio *bio)
 {
 	struct bio_vec *bvec;
 	int i;
+	/* hint all but last page with MSG_MORE */
 	__bio_for_each_segment(bvec, bio, i, 0) {
 		if (!_drbd_send_page(mdev, bvec->bv_page,
-				     bvec->bv_offset, bvec->bv_len))
+				     bvec->bv_offset, bvec->bv_len,
+				     i == bio->bi_vcnt -1 ? 0 : MSG_MORE))
+			return 0;
+	}
+	return 1;
+}
+
+static int _drbd_send_zc_ee(struct drbd_conf *mdev, struct drbd_epoch_entry *e)
+{
+	struct page *page = e->pages;
+	unsigned len = e->size;
+	/* hint all but last page with MSG_MORE */
+	page_chain_for_each(page) {
+		unsigned l = min_t(unsigned, len, PAGE_SIZE);
+		if (!_drbd_send_page(mdev, page, 0, l,
+				page_chain_next(page) ? MSG_MORE : 0))
 			return 0;
+		len -= l;
 	}
+	return 1;
+}
+
+static void consider_delay_probes(struct drbd_conf *mdev)
+{
+	if (mdev->state.conn != C_SYNC_SOURCE || mdev->agreed_pro_version < 93)
+		return;
+
+	if (mdev->dp_volume_last + mdev->sync_conf.dp_volume * 2 < mdev->send_cnt)
+		drbd_send_delay_probes(mdev);
+}
+
+static int w_delay_probes(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
+{
+	if (!cancel && mdev->state.conn == C_SYNC_SOURCE)
+		drbd_send_delay_probes(mdev);
 
 	return 1;
 }
 
+static void delay_probe_timer_fn(unsigned long data)
+{
+	struct drbd_conf *mdev = (struct drbd_conf *) data;
+
+	if (list_empty(&mdev->delay_probe_work.list))
+		drbd_queue_work(&mdev->data.work, &mdev->delay_probe_work);
+}
+
 /* Used to send write requests
  * R_PRIMARY -> Peer	(P_DATA)
  */
@@ -2357,11 +2444,11 @@ int drbd_send_dblock(struct drbd_conf *mdev, struct drbd_request *req)
 	p.dp_flags = cpu_to_be32(dp_flags);
 	set_bit(UNPLUG_REMOTE, &mdev->flags);
 	ok = (sizeof(p) ==
-		drbd_send(mdev, mdev->data.socket, &p, sizeof(p), MSG_MORE));
+		drbd_send(mdev, mdev->data.socket, &p, sizeof(p), dgs ? MSG_MORE : 0));
 	if (ok && dgs) {
 		dgb = mdev->int_dig_out;
-		drbd_csum(mdev, mdev->integrity_w_tfm, req->master_bio, dgb);
-		ok = drbd_send(mdev, mdev->data.socket, dgb, dgs, MSG_MORE);
+		drbd_csum_bio(mdev, mdev->integrity_w_tfm, req->master_bio, dgb);
+		ok = drbd_send(mdev, mdev->data.socket, dgb, dgs, 0);
 	}
 	if (ok) {
 		if (mdev->net_conf->wire_protocol == DRBD_PROT_A)
@@ -2371,6 +2458,10 @@ int drbd_send_dblock(struct drbd_conf *mdev, struct drbd_request *req)
 	}
 
 	drbd_put_data_sock(mdev);
+
+	if (ok)
+		consider_delay_probes(mdev);
+
 	return ok;
 }
 
@@ -2406,16 +2497,20 @@ int drbd_send_block(struct drbd_conf *mdev, enum drbd_packets cmd,
 		return 0;
 
 	ok = sizeof(p) == drbd_send(mdev, mdev->data.socket, &p,
-					sizeof(p), MSG_MORE);
+					sizeof(p), dgs ? MSG_MORE : 0);
 	if (ok && dgs) {
 		dgb = mdev->int_dig_out;
-		drbd_csum(mdev, mdev->integrity_w_tfm, e->private_bio, dgb);
-		ok = drbd_send(mdev, mdev->data.socket, dgb, dgs, MSG_MORE);
+		drbd_csum_ee(mdev, mdev->integrity_w_tfm, e, dgb);
+		ok = drbd_send(mdev, mdev->data.socket, dgb, dgs, 0);
 	}
 	if (ok)
-		ok = _drbd_send_zc_bio(mdev, e->private_bio);
+		ok = _drbd_send_zc_ee(mdev, e);
 
 	drbd_put_data_sock(mdev);
+
+	if (ok)
+		consider_delay_probes(mdev);
+
 	return ok;
 }
 
@@ -2628,16 +2723,24 @@ void drbd_init_set_defaults(struct drbd_conf *mdev)
 	INIT_LIST_HEAD(&mdev->unplug_work.list);
 	INIT_LIST_HEAD(&mdev->md_sync_work.list);
 	INIT_LIST_HEAD(&mdev->bm_io_work.w.list);
+	INIT_LIST_HEAD(&mdev->delay_probes);
+	INIT_LIST_HEAD(&mdev->delay_probe_work.list);
+
 	mdev->resync_work.cb  = w_resync_inactive;
 	mdev->unplug_work.cb  = w_send_write_hint;
 	mdev->md_sync_work.cb = w_md_sync;
 	mdev->bm_io_work.w.cb = w_bitmap_io;
+	mdev->delay_probe_work.cb = w_delay_probes;
 	init_timer(&mdev->resync_timer);
 	init_timer(&mdev->md_sync_timer);
+	init_timer(&mdev->delay_probe_timer);
 	mdev->resync_timer.function = resync_timer_fn;
 	mdev->resync_timer.data = (unsigned long) mdev;
 	mdev->md_sync_timer.function = md_sync_timer_fn;
 	mdev->md_sync_timer.data = (unsigned long) mdev;
+	mdev->delay_probe_timer.function = delay_probe_timer_fn;
+	mdev->delay_probe_timer.data = (unsigned long) mdev;
+
 
 	init_waitqueue_head(&mdev->misc_wait);
 	init_waitqueue_head(&mdev->state_wait);
@@ -2680,7 +2783,7 @@ void drbd_mdev_cleanup(struct drbd_conf *mdev)
 	drbd_set_my_capacity(mdev, 0);
 	if (mdev->bitmap) {
 		/* maybe never allocated. */
-		drbd_bm_resize(mdev, 0);
+		drbd_bm_resize(mdev, 0, 1);
 		drbd_bm_cleanup(mdev);
 	}
 
@@ -3129,7 +3232,7 @@ int __init drbd_init(void)
 	if (err)
 		goto Enomem;
 
-	drbd_proc = proc_create("drbd", S_IFREG | S_IRUGO , NULL, &drbd_proc_fops);
+	drbd_proc = proc_create_data("drbd", S_IFREG | S_IRUGO , NULL, &drbd_proc_fops, NULL);
 	if (!drbd_proc)	{
 		printk(KERN_ERR "drbd: unable to register proc file\n");
 		goto Enomem;
@@ -3660,7 +3763,8 @@ _drbd_fault_str(unsigned int type) {
 		[DRBD_FAULT_DT_RD] = "Data read",
 		[DRBD_FAULT_DT_RA] = "Data read ahead",
 		[DRBD_FAULT_BM_ALLOC] = "BM allocation",
-		[DRBD_FAULT_AL_EE] = "EE allocation"
+		[DRBD_FAULT_AL_EE] = "EE allocation",
+		[DRBD_FAULT_RECEIVE] = "receive data corruption",
 	};
 
 	return (type < DRBD_FAULT_MAX) ? _faults[type] : "**Unknown**";
@@ -3679,7 +3783,7 @@ _drbd_insert_fault(struct drbd_conf *mdev, unsigned int type)
 	if (ret) {
 		fault_count++;
 
-		if (printk_ratelimit())
+		if (__ratelimit(&drbd_ratelimit_state))
 			dev_warn(DEV, "***Simulating %s failure\n",
 				_drbd_fault_str(type));
 	}
diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
index 6429d2b19e0..632e3245d1b 100644
--- a/drivers/block/drbd/drbd_nl.c
+++ b/drivers/block/drbd/drbd_nl.c
@@ -510,7 +510,7 @@ void drbd_resume_io(struct drbd_conf *mdev)
  * Returns 0 on success, negative return values indicate errors.
  * You should call drbd_md_sync() after calling this function.
  */
-enum determine_dev_size drbd_determin_dev_size(struct drbd_conf *mdev, int force) __must_hold(local)
+enum determine_dev_size drbd_determin_dev_size(struct drbd_conf *mdev, enum dds_flags flags) __must_hold(local)
 {
 	sector_t prev_first_sect, prev_size; /* previous meta location */
 	sector_t la_size;
@@ -541,12 +541,12 @@ enum determine_dev_size drbd_determin_dev_size(struct drbd_conf *mdev, int force
 	/* TODO: should only be some assert here, not (re)init... */
 	drbd_md_set_sector_offsets(mdev, mdev->ldev);
 
-	size = drbd_new_dev_size(mdev, mdev->ldev, force);
+	size = drbd_new_dev_size(mdev, mdev->ldev, flags & DDSF_FORCED);
 
 	if (drbd_get_capacity(mdev->this_bdev) != size ||
 	    drbd_bm_capacity(mdev) != size) {
 		int err;
-		err = drbd_bm_resize(mdev, size);
+		err = drbd_bm_resize(mdev, size, !(flags & DDSF_NO_RESYNC));
 		if (unlikely(err)) {
 			/* currently there is only one error: ENOMEM! */
 			size = drbd_bm_capacity(mdev)>>1;
@@ -704,9 +704,6 @@ void drbd_setup_queue_param(struct drbd_conf *mdev, unsigned int max_seg_s) __mu
 	struct request_queue * const b = mdev->ldev->backing_bdev->bd_disk->queue;
 	int max_segments = mdev->ldev->dc.max_bio_bvecs;
 
-	if (b->merge_bvec_fn && !mdev->ldev->dc.use_bmbv)
-		max_seg_s = PAGE_SIZE;
-
 	max_seg_s = min(queue_max_sectors(b) * queue_logical_block_size(b), max_seg_s);
 
 	blk_queue_max_hw_sectors(q, max_seg_s >> 9);
@@ -1199,13 +1196,12 @@ static int drbd_nl_net_conf(struct drbd_conf *mdev, struct drbd_nl_cfg_req *nlp,
 	}
 
 	/* allocation not in the IO path, cqueue thread context */
-	new_conf = kmalloc(sizeof(struct net_conf), GFP_KERNEL);
+	new_conf = kzalloc(sizeof(struct net_conf), GFP_KERNEL);
 	if (!new_conf) {
 		retcode = ERR_NOMEM;
 		goto fail;
 	}
 
-	memset(new_conf, 0, sizeof(struct net_conf));
 	new_conf->timeout	   = DRBD_TIMEOUT_DEF;
 	new_conf->try_connect_int  = DRBD_CONNECT_INT_DEF;
 	new_conf->ping_int	   = DRBD_PING_INT_DEF;
@@ -1477,8 +1473,8 @@ static int drbd_nl_resize(struct drbd_conf *mdev, struct drbd_nl_cfg_req *nlp,
 {
 	struct resize rs;
 	int retcode = NO_ERROR;
-	int ldsc = 0; /* local disk size changed */
 	enum determine_dev_size dd;
+	enum dds_flags ddsf;
 
 	memset(&rs, 0, sizeof(struct resize));
 	if (!resize_from_tags(mdev, nlp->tag_list, &rs)) {
@@ -1502,13 +1498,17 @@ static int drbd_nl_resize(struct drbd_conf *mdev, struct drbd_nl_cfg_req *nlp,
 		goto fail;
 	}
 
-	if (mdev->ldev->known_size != drbd_get_capacity(mdev->ldev->backing_bdev)) {
-		mdev->ldev->known_size = drbd_get_capacity(mdev->ldev->backing_bdev);
-		ldsc = 1;
+	if (rs.no_resync && mdev->agreed_pro_version < 93) {
+		retcode = ERR_NEED_APV_93;
+		goto fail;
 	}
 
+	if (mdev->ldev->known_size != drbd_get_capacity(mdev->ldev->backing_bdev))
+		mdev->ldev->known_size = drbd_get_capacity(mdev->ldev->backing_bdev);
+
 	mdev->ldev->dc.disk_size = (sector_t)rs.resize_size;
-	dd = drbd_determin_dev_size(mdev, rs.resize_force);
+	ddsf = (rs.resize_force ? DDSF_FORCED : 0) | (rs.no_resync ? DDSF_NO_RESYNC : 0);
+	dd = drbd_determin_dev_size(mdev, ddsf);
 	drbd_md_sync(mdev);
 	put_ldev(mdev);
 	if (dd == dev_size_error) {
@@ -1516,12 +1516,12 @@ static int drbd_nl_resize(struct drbd_conf *mdev, struct drbd_nl_cfg_req *nlp,
 		goto fail;
 	}
 
-	if (mdev->state.conn == C_CONNECTED && (dd != unchanged || ldsc)) {
+	if (mdev->state.conn == C_CONNECTED) {
 		if (dd == grew)
 			set_bit(RESIZE_PENDING, &mdev->flags);
 
 		drbd_send_uuids(mdev);
-		drbd_send_sizes(mdev, 1);
+		drbd_send_sizes(mdev, 1, ddsf);
 	}
 
  fail:
@@ -1551,6 +1551,10 @@ static int drbd_nl_syncer_conf(struct drbd_conf *mdev, struct drbd_nl_cfg_req *n
 		sc.rate       = DRBD_RATE_DEF;
 		sc.after      = DRBD_AFTER_DEF;
 		sc.al_extents = DRBD_AL_EXTENTS_DEF;
+		sc.dp_volume  = DRBD_DP_VOLUME_DEF;
+		sc.dp_interval = DRBD_DP_INTERVAL_DEF;
+		sc.throttle_th = DRBD_RS_THROTTLE_TH_DEF;
+		sc.hold_off_th = DRBD_RS_HOLD_OFF_TH_DEF;
 	} else
 		memcpy(&sc, &mdev->sync_conf, sizeof(struct syncer_conf));
 
@@ -2207,9 +2211,9 @@ void drbd_bcast_ee(struct drbd_conf *mdev,
 {
 	struct cn_msg *cn_reply;
 	struct drbd_nl_cfg_reply *reply;
-	struct bio_vec *bvec;
 	unsigned short *tl;
-	int i;
+	struct page *page;
+	unsigned len;
 
 	if (!e)
 		return;
@@ -2247,11 +2251,15 @@ void drbd_bcast_ee(struct drbd_conf *mdev,
 	put_unaligned(T_ee_data, tl++);
 	put_unaligned(e->size, tl++);
 
-	__bio_for_each_segment(bvec, e->private_bio, i, 0) {
-		void *d = kmap(bvec->bv_page);
-		memcpy(tl, d + bvec->bv_offset, bvec->bv_len);
-		kunmap(bvec->bv_page);
-		tl=(unsigned short*)((char*)tl + bvec->bv_len);
+	len = e->size;
+	page = e->pages;
+	page_chain_for_each(page) {
+		void *d = kmap_atomic(page, KM_USER0);
+		unsigned l = min_t(unsigned, len, PAGE_SIZE);
+		memcpy(tl, d, l);
+		kunmap_atomic(d, KM_USER0);
+		tl = (unsigned short*)((char*)tl + l);
+		len -= l;
 	}
 	put_unaligned(TT_END, tl++); /* Close the tag list */
 
diff --git a/drivers/block/drbd/drbd_proc.c b/drivers/block/drbd/drbd_proc.c
index be3374b6846..d0f1767ea4c 100644
--- a/drivers/block/drbd/drbd_proc.c
+++ b/drivers/block/drbd/drbd_proc.c
@@ -73,14 +73,21 @@ static void drbd_syncer_progress(struct drbd_conf *mdev, struct seq_file *seq)
 	seq_printf(seq, "sync'ed:%3u.%u%% ", res / 10, res % 10);
 	/* if more than 1 GB display in MB */
 	if (mdev->rs_total > 0x100000L)
-		seq_printf(seq, "(%lu/%lu)M\n\t",
+		seq_printf(seq, "(%lu/%lu)M",
 			    (unsigned long) Bit2KB(rs_left >> 10),
 			    (unsigned long) Bit2KB(mdev->rs_total >> 10));
 	else
-		seq_printf(seq, "(%lu/%lu)K\n\t",
+		seq_printf(seq, "(%lu/%lu)K",
 			    (unsigned long) Bit2KB(rs_left),
 			    (unsigned long) Bit2KB(mdev->rs_total));
 
+	if (mdev->state.conn == C_SYNC_TARGET)
+		seq_printf(seq, " queue_delay: %d.%d ms\n\t",
+			   mdev->data_delay / 1000,
+			   (mdev->data_delay % 1000) / 100);
+	else if (mdev->state.conn == C_SYNC_SOURCE)
+		seq_printf(seq, " delay_probe: %u\n\t", mdev->delay_seq);
+
 	/* see drivers/md/md.c
 	 * We do not want to overflow, so the order of operands and
 	 * the * 100 / 100 trick are important. We do a +1 to be
@@ -128,6 +135,14 @@ static void drbd_syncer_progress(struct drbd_conf *mdev, struct seq_file *seq)
 	else
 		seq_printf(seq, " (%ld)", dbdt);
 
+	if (mdev->state.conn == C_SYNC_TARGET) {
+		if (mdev->c_sync_rate > 1000)
+			seq_printf(seq, " want: %d,%03d",
+				   mdev->c_sync_rate / 1000, mdev->c_sync_rate % 1000);
+		else
+			seq_printf(seq, " want: %d", mdev->c_sync_rate);
+	}
+
 	seq_printf(seq, " K/sec\n");
 }
 
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index 3f096e7959b..dff48701b84 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -42,7 +42,6 @@
 #include <linux/unistd.h>
 #include <linux/vmalloc.h>
 #include <linux/random.h>
-#include <linux/mm.h>
 #include <linux/string.h>
 #include <linux/scatterlist.h>
 #include "drbd_int.h"
@@ -80,30 +79,128 @@ static struct drbd_epoch *previous_epoch(struct drbd_conf *mdev, struct drbd_epo
 
 #define GFP_TRY	(__GFP_HIGHMEM | __GFP_NOWARN)
 
-static struct page *drbd_pp_first_page_or_try_alloc(struct drbd_conf *mdev)
+/*
+ * some helper functions to deal with single linked page lists,
+ * page->private being our "next" pointer.
+ */
+
+/* If at least n pages are linked at head, get n pages off.
+ * Otherwise, don't modify head, and return NULL.
+ * Locking is the responsibility of the caller.
+ */
+static struct page *page_chain_del(struct page **head, int n)
+{
+	struct page *page;
+	struct page *tmp;
+
+	BUG_ON(!n);
+	BUG_ON(!head);
+
+	page = *head;
+
+	if (!page)
+		return NULL;
+
+	while (page) {
+		tmp = page_chain_next(page);
+		if (--n == 0)
+			break; /* found sufficient pages */
+		if (tmp == NULL)
+			/* insufficient pages, don't use any of them. */
+			return NULL;
+		page = tmp;
+	}
+
+	/* add end of list marker for the returned list */
+	set_page_private(page, 0);
+	/* actual return value, and adjustment of head */
+	page = *head;
+	*head = tmp;
+	return page;
+}
+
+/* may be used outside of locks to find the tail of a (usually short)
+ * "private" page chain, before adding it back to a global chain head
+ * with page_chain_add() under a spinlock. */
+static struct page *page_chain_tail(struct page *page, int *len)
+{
+	struct page *tmp;
+	int i = 1;
+	while ((tmp = page_chain_next(page)))
+		++i, page = tmp;
+	if (len)
+		*len = i;
+	return page;
+}
+
+static int page_chain_free(struct page *page)
+{
+	struct page *tmp;
+	int i = 0;
+	page_chain_for_each_safe(page, tmp) {
+		put_page(page);
+		++i;
+	}
+	return i;
+}
+
+static void page_chain_add(struct page **head,
+		struct page *chain_first, struct page *chain_last)
+{
+#if 1
+	struct page *tmp;
+	tmp = page_chain_tail(chain_first, NULL);
+	BUG_ON(tmp != chain_last);
+#endif
+
+	/* add chain to head */
+	set_page_private(chain_last, (unsigned long)*head);
+	*head = chain_first;
+}
+
+static struct page *drbd_pp_first_pages_or_try_alloc(struct drbd_conf *mdev, int number)
 {
 	struct page *page = NULL;
+	struct page *tmp = NULL;
+	int i = 0;
 
 	/* Yes, testing drbd_pp_vacant outside the lock is racy.
 	 * So what. It saves a spin_lock. */
-	if (drbd_pp_vacant > 0) {
+	if (drbd_pp_vacant >= number) {
 		spin_lock(&drbd_pp_lock);
-		page = drbd_pp_pool;
-		if (page) {
-			drbd_pp_pool = (struct page *)page_private(page);
-			set_page_private(page, 0); /* just to be polite */
-			drbd_pp_vacant--;
-		}
+		page = page_chain_del(&drbd_pp_pool, number);
+		if (page)
+			drbd_pp_vacant -= number;
 		spin_unlock(&drbd_pp_lock);
+		if (page)
+			return page;
 	}
+
 	/* GFP_TRY, because we must not cause arbitrary write-out: in a DRBD
 	 * "criss-cross" setup, that might cause write-out on some other DRBD,
 	 * which in turn might block on the other node at this very place.  */
-	if (!page)
-		page = alloc_page(GFP_TRY);
-	if (page)
-		atomic_inc(&mdev->pp_in_use);
-	return page;
+	for (i = 0; i < number; i++) {
+		tmp = alloc_page(GFP_TRY);
+		if (!tmp)
+			break;
+		set_page_private(tmp, (unsigned long)page);
+		page = tmp;
+	}
+
+	if (i == number)
+		return page;
+
+	/* Not enough pages immediately available this time.
+	 * No need to jump around here, drbd_pp_alloc will retry this
+	 * function "soon". */
+	if (page) {
+		tmp = page_chain_tail(page, NULL);
+		spin_lock(&drbd_pp_lock);
+		page_chain_add(&drbd_pp_pool, page, tmp);
+		drbd_pp_vacant += i;
+		spin_unlock(&drbd_pp_lock);
+	}
+	return NULL;
 }
 
 /* kick lower level device, if we have more than (arbitrary number)
@@ -127,7 +224,7 @@ static void reclaim_net_ee(struct drbd_conf *mdev, struct list_head *to_be_freed
 
 	list_for_each_safe(le, tle, &mdev->net_ee) {
 		e = list_entry(le, struct drbd_epoch_entry, w.list);
-		if (drbd_bio_has_active_page(e->private_bio))
+		if (drbd_ee_has_active_page(e))
 			break;
 		list_move(le, to_be_freed);
 	}
@@ -148,32 +245,34 @@ static void drbd_kick_lo_and_reclaim_net(struct drbd_conf *mdev)
 }
 
 /**
- * drbd_pp_alloc() - Returns a page, fails only if a signal comes in
+ * drbd_pp_alloc() - Returns @number pages, retries forever (or until signalled)
  * @mdev:	DRBD device.
- * @retry:	whether or not to retry allocation forever (or until signalled)
+ * @number:	number of pages requested
+ * @retry:	whether to retry, if not enough pages are available right now
+ *
+ * Tries to allocate number pages, first from our own page pool, then from
+ * the kernel, unless this allocation would exceed the max_buffers setting.
+ * Possibly retry until DRBD frees sufficient pages somewhere else.
  *
- * Tries to allocate a page, first from our own page pool, then from the
- * kernel, unless this allocation would exceed the max_buffers setting.
- * If @retry is non-zero, retry until DRBD frees a page somewhere else.
+ * Returns a page chain linked via page->private.
  */
-static struct page *drbd_pp_alloc(struct drbd_conf *mdev, int retry)
+static struct page *drbd_pp_alloc(struct drbd_conf *mdev, unsigned number, bool retry)
 {
 	struct page *page = NULL;
 	DEFINE_WAIT(wait);
 
-	if (atomic_read(&mdev->pp_in_use) < mdev->net_conf->max_buffers) {
-		page = drbd_pp_first_page_or_try_alloc(mdev);
-		if (page)
-			return page;
-	}
+	/* Yes, we may run up to @number over max_buffers. If we
+	 * follow it strictly, the admin will get it wrong anyways. */
+	if (atomic_read(&mdev->pp_in_use) < mdev->net_conf->max_buffers)
+		page = drbd_pp_first_pages_or_try_alloc(mdev, number);
 
-	for (;;) {
+	while (page == NULL) {
 		prepare_to_wait(&drbd_pp_wait, &wait, TASK_INTERRUPTIBLE);
 
 		drbd_kick_lo_and_reclaim_net(mdev);
 
 		if (atomic_read(&mdev->pp_in_use) < mdev->net_conf->max_buffers) {
-			page = drbd_pp_first_page_or_try_alloc(mdev);
+			page = drbd_pp_first_pages_or_try_alloc(mdev, number);
 			if (page)
 				break;
 		}
@@ -190,62 +289,32 @@ static struct page *drbd_pp_alloc(struct drbd_conf *mdev, int retry)
 	}
 	finish_wait(&drbd_pp_wait, &wait);
 
+	if (page)
+		atomic_add(number, &mdev->pp_in_use);
 	return page;
 }
 
 /* Must not be used from irq, as that may deadlock: see drbd_pp_alloc.
- * Is also used from inside an other spin_lock_irq(&mdev->req_lock) */
+ * Is also used from inside an other spin_lock_irq(&mdev->req_lock);
+ * Either links the page chain back to the global pool,
+ * or returns all pages to the system. */
 static void drbd_pp_free(struct drbd_conf *mdev, struct page *page)
 {
-	int free_it;
-
-	spin_lock(&drbd_pp_lock);
-	if (drbd_pp_vacant > (DRBD_MAX_SEGMENT_SIZE/PAGE_SIZE)*minor_count) {
-		free_it = 1;
-	} else {
-		set_page_private(page, (unsigned long)drbd_pp_pool);
-		drbd_pp_pool = page;
-		drbd_pp_vacant++;
-		free_it = 0;
-	}
-	spin_unlock(&drbd_pp_lock);
-
-	atomic_dec(&mdev->pp_in_use);
-
-	if (free_it)
-		__free_page(page);
-
-	wake_up(&drbd_pp_wait);
-}
-
-static void drbd_pp_free_bio_pages(struct drbd_conf *mdev, struct bio *bio)
-{
-	struct page *p_to_be_freed = NULL;
-	struct page *page;
-	struct bio_vec *bvec;
 	int i;
-
-	spin_lock(&drbd_pp_lock);
-	__bio_for_each_segment(bvec, bio, i, 0) {
-		if (drbd_pp_vacant > (DRBD_MAX_SEGMENT_SIZE/PAGE_SIZE)*minor_count) {
-			set_page_private(bvec->bv_page, (unsigned long)p_to_be_freed);
-			p_to_be_freed = bvec->bv_page;
-		} else {
-			set_page_private(bvec->bv_page, (unsigned long)drbd_pp_pool);
-			drbd_pp_pool = bvec->bv_page;
-			drbd_pp_vacant++;
-		}
-	}
-	spin_unlock(&drbd_pp_lock);
-	atomic_sub(bio->bi_vcnt, &mdev->pp_in_use);
-
-	while (p_to_be_freed) {
-		page = p_to_be_freed;
-		p_to_be_freed = (struct page *)page_private(page);
-		set_page_private(page, 0); /* just to be polite */
-		put_page(page);
+	if (drbd_pp_vacant > (DRBD_MAX_SEGMENT_SIZE/PAGE_SIZE)*minor_count)
+		i = page_chain_free(page);
+	else {
+		struct page *tmp;
+		tmp = page_chain_tail(page, &i);
+		spin_lock(&drbd_pp_lock);
+		page_chain_add(&drbd_pp_pool, page, tmp);
+		drbd_pp_vacant += i;
+		spin_unlock(&drbd_pp_lock);
 	}
-
+	atomic_sub(i, &mdev->pp_in_use);
+	i = atomic_read(&mdev->pp_in_use);
+	if (i < 0)
+		dev_warn(DEV, "ASSERTION FAILED: pp_in_use: %d < 0\n", i);
 	wake_up(&drbd_pp_wait);
 }
 
@@ -270,11 +339,9 @@ struct drbd_epoch_entry *drbd_alloc_ee(struct drbd_conf *mdev,
 				     unsigned int data_size,
 				     gfp_t gfp_mask) __must_hold(local)
 {
-	struct request_queue *q;
 	struct drbd_epoch_entry *e;
 	struct page *page;
-	struct bio *bio;
-	unsigned int ds;
+	unsigned nr_pages = (data_size + PAGE_SIZE -1) >> PAGE_SHIFT;
 
 	if (FAULT_ACTIVE(mdev, DRBD_FAULT_AL_EE))
 		return NULL;
@@ -286,84 +353,32 @@ struct drbd_epoch_entry *drbd_alloc_ee(struct drbd_conf *mdev,
 		return NULL;
 	}
 
-	bio = bio_alloc(gfp_mask & ~__GFP_HIGHMEM, div_ceil(data_size, PAGE_SIZE));
-	if (!bio) {
-		if (!(gfp_mask & __GFP_NOWARN))
-			dev_err(DEV, "alloc_ee: Allocation of a bio failed\n");
-		goto fail1;
-	}
-
-	bio->bi_bdev = mdev->ldev->backing_bdev;
-	bio->bi_sector = sector;
-
-	ds = data_size;
-	while (ds) {
-		page = drbd_pp_alloc(mdev, (gfp_mask & __GFP_WAIT));
-		if (!page) {
-			if (!(gfp_mask & __GFP_NOWARN))
-				dev_err(DEV, "alloc_ee: Allocation of a page failed\n");
-			goto fail2;
-		}
-		if (!bio_add_page(bio, page, min_t(int, ds, PAGE_SIZE), 0)) {
-			drbd_pp_free(mdev, page);
-			dev_err(DEV, "alloc_ee: bio_add_page(s=%llu,"
-			    "data_size=%u,ds=%u) failed\n",
-			    (unsigned long long)sector, data_size, ds);
-
-			q = bdev_get_queue(bio->bi_bdev);
-			if (q->merge_bvec_fn) {
-				struct bvec_merge_data bvm = {
-					.bi_bdev = bio->bi_bdev,
-					.bi_sector = bio->bi_sector,
-					.bi_size = bio->bi_size,
-					.bi_rw = bio->bi_rw,
-				};
-				int l = q->merge_bvec_fn(q, &bvm,
-						&bio->bi_io_vec[bio->bi_vcnt]);
-				dev_err(DEV, "merge_bvec_fn() = %d\n", l);
-			}
-
-			/* dump more of the bio. */
-			dev_err(DEV, "bio->bi_max_vecs = %d\n", bio->bi_max_vecs);
-			dev_err(DEV, "bio->bi_vcnt = %d\n", bio->bi_vcnt);
-			dev_err(DEV, "bio->bi_size = %d\n", bio->bi_size);
-			dev_err(DEV, "bio->bi_phys_segments = %d\n", bio->bi_phys_segments);
-
-			goto fail2;
-			break;
-		}
-		ds -= min_t(int, ds, PAGE_SIZE);
-	}
-
-	D_ASSERT(data_size == bio->bi_size);
-
-	bio->bi_private = e;
-	e->mdev = mdev;
-	e->sector = sector;
-	e->size = bio->bi_size;
+	page = drbd_pp_alloc(mdev, nr_pages, (gfp_mask & __GFP_WAIT));
+	if (!page)
+		goto fail;
 
-	e->private_bio = bio;
-	e->block_id = id;
 	INIT_HLIST_NODE(&e->colision);
 	e->epoch = NULL;
+	e->mdev = mdev;
+	e->pages = page;
+	atomic_set(&e->pending_bios, 0);
+	e->size = data_size;
 	e->flags = 0;
+	e->sector = sector;
+	e->sector = sector;
+	e->block_id = id;
 
 	return e;
 
- fail2:
-	drbd_pp_free_bio_pages(mdev, bio);
-	bio_put(bio);
- fail1:
+ fail:
 	mempool_free(e, drbd_ee_mempool);
-
 	return NULL;
 }
 
 void drbd_free_ee(struct drbd_conf *mdev, struct drbd_epoch_entry *e)
 {
-	struct bio *bio = e->private_bio;
-	drbd_pp_free_bio_pages(mdev, bio);
-	bio_put(bio);
+	drbd_pp_free(mdev, e->pages);
+	D_ASSERT(atomic_read(&e->pending_bios) == 0);
 	D_ASSERT(hlist_unhashed(&e->colision));
 	mempool_free(e, drbd_ee_mempool);
 }
@@ -555,6 +570,25 @@ static int drbd_recv(struct drbd_conf *mdev, void *buf, size_t size)
 	return rv;
 }
 
+/* quoting tcp(7):
+ *   On individual connections, the socket buffer size must be set prior to the
+ *   listen(2) or connect(2) calls in order to have it take effect.
+ * This is our wrapper to do so.
+ */
+static void drbd_setbufsize(struct socket *sock, unsigned int snd,
+		unsigned int rcv)
+{
+	/* open coded SO_SNDBUF, SO_RCVBUF */
+	if (snd) {
+		sock->sk->sk_sndbuf = snd;
+		sock->sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
+	}
+	if (rcv) {
+		sock->sk->sk_rcvbuf = rcv;
+		sock->sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
+	}
+}
+
 static struct socket *drbd_try_connect(struct drbd_conf *mdev)
 {
 	const char *what;
@@ -576,6 +610,8 @@ static struct socket *drbd_try_connect(struct drbd_conf *mdev)
 
 	sock->sk->sk_rcvtimeo =
 	sock->sk->sk_sndtimeo =  mdev->net_conf->try_connect_int*HZ;
+	drbd_setbufsize(sock, mdev->net_conf->sndbuf_size,
+			mdev->net_conf->rcvbuf_size);
 
        /* explicitly bind to the configured IP as source IP
 	*  for the outgoing connections.
@@ -654,6 +690,8 @@ static struct socket *drbd_wait_for_connect(struct drbd_conf *mdev)
 	s_listen->sk->sk_reuse    = 1; /* SO_REUSEADDR */
 	s_listen->sk->sk_rcvtimeo = timeo;
 	s_listen->sk->sk_sndtimeo = timeo;
+	drbd_setbufsize(s_listen, mdev->net_conf->sndbuf_size,
+			mdev->net_conf->rcvbuf_size);
 
 	what = "bind before listen";
 	err = s_listen->ops->bind(s_listen,
@@ -840,16 +878,6 @@ retry:
 	sock->sk->sk_priority = TC_PRIO_INTERACTIVE_BULK;
 	msock->sk->sk_priority = TC_PRIO_INTERACTIVE;
 
-	if (mdev->net_conf->sndbuf_size) {
-		sock->sk->sk_sndbuf = mdev->net_conf->sndbuf_size;
-		sock->sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
-	}
-
-	if (mdev->net_conf->rcvbuf_size) {
-		sock->sk->sk_rcvbuf = mdev->net_conf->rcvbuf_size;
-		sock->sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
-	}
-
 	/* NOT YET ...
 	 * sock->sk->sk_sndtimeo = mdev->net_conf->timeout*HZ/10;
 	 * sock->sk->sk_rcvtimeo = MAX_SCHEDULE_TIMEOUT;
@@ -902,7 +930,7 @@ retry:
 	if (!drbd_send_protocol(mdev))
 		return -1;
 	drbd_send_sync_param(mdev, &mdev->sync_conf);
-	drbd_send_sizes(mdev, 0);
+	drbd_send_sizes(mdev, 0, 0);
 	drbd_send_uuids(mdev);
 	drbd_send_state(mdev);
 	clear_bit(USE_DEGR_WFC_T, &mdev->flags);
@@ -946,7 +974,8 @@ static enum finish_epoch drbd_flush_after_epoch(struct drbd_conf *mdev, struct d
 	int rv;
 
 	if (mdev->write_ordering >= WO_bdev_flush && get_ldev(mdev)) {
-		rv = blkdev_issue_flush(mdev->ldev->backing_bdev, NULL);
+		rv = blkdev_issue_flush(mdev->ldev->backing_bdev, GFP_KERNEL,
+					NULL, BLKDEV_IFL_WAIT);
 		if (rv) {
 			dev_err(DEV, "local disk flush failed with status %d\n", rv);
 			/* would rather check on EOPNOTSUPP, but that is not reliable.
@@ -1120,6 +1149,90 @@ void drbd_bump_write_ordering(struct drbd_conf *mdev, enum write_ordering_e wo)
 }
 
 /**
+ * drbd_submit_ee()
+ * @mdev:	DRBD device.
+ * @e:		epoch entry
+ * @rw:		flag field, see bio->bi_rw
+ */
+/* TODO allocate from our own bio_set. */
+int drbd_submit_ee(struct drbd_conf *mdev, struct drbd_epoch_entry *e,
+		const unsigned rw, const int fault_type)
+{
+	struct bio *bios = NULL;
+	struct bio *bio;
+	struct page *page = e->pages;
+	sector_t sector = e->sector;
+	unsigned ds = e->size;
+	unsigned n_bios = 0;
+	unsigned nr_pages = (ds + PAGE_SIZE -1) >> PAGE_SHIFT;
+
+	/* In most cases, we will only need one bio.  But in case the lower
+	 * level restrictions happen to be different at this offset on this
+	 * side than those of the sending peer, we may need to submit the
+	 * request in more than one bio. */
+next_bio:
+	bio = bio_alloc(GFP_NOIO, nr_pages);
+	if (!bio) {
+		dev_err(DEV, "submit_ee: Allocation of a bio failed\n");
+		goto fail;
+	}
+	/* > e->sector, unless this is the first bio */
+	bio->bi_sector = sector;
+	bio->bi_bdev = mdev->ldev->backing_bdev;
+	/* we special case some flags in the multi-bio case, see below
+	 * (BIO_RW_UNPLUG, BIO_RW_BARRIER) */
+	bio->bi_rw = rw;
+	bio->bi_private = e;
+	bio->bi_end_io = drbd_endio_sec;
+
+	bio->bi_next = bios;
+	bios = bio;
+	++n_bios;
+
+	page_chain_for_each(page) {
+		unsigned len = min_t(unsigned, ds, PAGE_SIZE);
+		if (!bio_add_page(bio, page, len, 0)) {
+			/* a single page must always be possible! */
+			BUG_ON(bio->bi_vcnt == 0);
+			goto next_bio;
+		}
+		ds -= len;
+		sector += len >> 9;
+		--nr_pages;
+	}
+	D_ASSERT(page == NULL);
+	D_ASSERT(ds == 0);
+
+	atomic_set(&e->pending_bios, n_bios);
+	do {
+		bio = bios;
+		bios = bios->bi_next;
+		bio->bi_next = NULL;
+
+		/* strip off BIO_RW_UNPLUG unless it is the last bio */
+		if (bios)
+			bio->bi_rw &= ~(1<<BIO_RW_UNPLUG);
+
+		drbd_generic_make_request(mdev, fault_type, bio);
+
+		/* strip off BIO_RW_BARRIER,
+		 * unless it is the first or last bio */
+		if (bios && bios->bi_next)
+			bios->bi_rw &= ~(1<<BIO_RW_BARRIER);
+	} while (bios);
+	maybe_kick_lo(mdev);
+	return 0;
+
+fail:
+	while (bios) {
+		bio = bios;
+		bios = bios->bi_next;
+		bio_put(bio);
+	}
+	return -ENOMEM;
+}
+
+/**
  * w_e_reissue() - Worker callback; Resubmit a bio, without BIO_RW_BARRIER set
  * @mdev:	DRBD device.
  * @w:		work object.
@@ -1128,8 +1241,6 @@ void drbd_bump_write_ordering(struct drbd_conf *mdev, enum write_ordering_e wo)
 int w_e_reissue(struct drbd_conf *mdev, struct drbd_work *w, int cancel) __releases(local)
 {
 	struct drbd_epoch_entry *e = (struct drbd_epoch_entry *)w;
-	struct bio *bio = e->private_bio;
-
 	/* We leave DE_CONTAINS_A_BARRIER and EE_IS_BARRIER in place,
 	   (and DE_BARRIER_IN_NEXT_EPOCH_ISSUED in the previous Epoch)
 	   so that we can finish that epoch in drbd_may_finish_epoch().
@@ -1143,33 +1254,17 @@ int w_e_reissue(struct drbd_conf *mdev, struct drbd_work *w, int cancel) __relea
 	if (previous_epoch(mdev, e->epoch))
 		dev_warn(DEV, "Write ordering was not enforced (one time event)\n");
 
-	/* prepare bio for re-submit,
-	 * re-init volatile members */
 	/* we still have a local reference,
 	 * get_ldev was done in receive_Data. */
-	bio->bi_bdev = mdev->ldev->backing_bdev;
-	bio->bi_sector = e->sector;
-	bio->bi_size = e->size;
-	bio->bi_idx = 0;
-
-	bio->bi_flags &= ~(BIO_POOL_MASK - 1);
-	bio->bi_flags |= 1 << BIO_UPTODATE;
-
-	/* don't know whether this is necessary: */
-	bio->bi_phys_segments = 0;
-	bio->bi_next = NULL;
-
-	/* these should be unchanged: */
-	/* bio->bi_end_io = drbd_endio_write_sec; */
-	/* bio->bi_vcnt = whatever; */
 
 	e->w.cb = e_end_block;
-
-	/* This is no longer a barrier request. */
-	bio->bi_rw &= ~(1UL << BIO_RW_BARRIER);
-
-	drbd_generic_make_request(mdev, DRBD_FAULT_DT_WR, bio);
-
+	if (drbd_submit_ee(mdev, e, WRITE, DRBD_FAULT_DT_WR) != 0) {
+		/* drbd_submit_ee fails for one reason only:
+		 * if was not able to allocate sufficient bios.
+		 * requeue, try again later. */
+		e->w.cb = w_e_reissue;
+		drbd_queue_work(&mdev->data.work, &e->w);
+	}
 	return 1;
 }
 
@@ -1261,13 +1356,13 @@ static int receive_Barrier(struct drbd_conf *mdev, struct p_header *h)
 static struct drbd_epoch_entry *
 read_in_block(struct drbd_conf *mdev, u64 id, sector_t sector, int data_size) __must_hold(local)
 {
+	const sector_t capacity = drbd_get_capacity(mdev->this_bdev);
 	struct drbd_epoch_entry *e;
-	struct bio_vec *bvec;
 	struct page *page;
-	struct bio *bio;
-	int dgs, ds, i, rr;
+	int dgs, ds, rr;
 	void *dig_in = mdev->int_dig_in;
 	void *dig_vv = mdev->int_dig_vv;
+	unsigned long *data;
 
 	dgs = (mdev->agreed_pro_version >= 87 && mdev->integrity_r_tfm) ?
 		crypto_hash_digestsize(mdev->integrity_r_tfm) : 0;
@@ -1286,29 +1381,44 @@ read_in_block(struct drbd_conf *mdev, u64 id, sector_t sector, int data_size) __
 	ERR_IF(data_size &  0x1ff) return NULL;
 	ERR_IF(data_size >  DRBD_MAX_SEGMENT_SIZE) return NULL;
 
+	/* even though we trust out peer,
+	 * we sometimes have to double check. */
+	if (sector + (data_size>>9) > capacity) {
+		dev_err(DEV, "capacity: %llus < sector: %llus + size: %u\n",
+			(unsigned long long)capacity,
+			(unsigned long long)sector, data_size);
+		return NULL;
+	}
+
 	/* GFP_NOIO, because we must not cause arbitrary write-out: in a DRBD
 	 * "criss-cross" setup, that might cause write-out on some other DRBD,
 	 * which in turn might block on the other node at this very place.  */
 	e = drbd_alloc_ee(mdev, id, sector, data_size, GFP_NOIO);
 	if (!e)
 		return NULL;
-	bio = e->private_bio;
+
 	ds = data_size;
-	bio_for_each_segment(bvec, bio, i) {
-		page = bvec->bv_page;
-		rr = drbd_recv(mdev, kmap(page), min_t(int, ds, PAGE_SIZE));
+	page = e->pages;
+	page_chain_for_each(page) {
+		unsigned len = min_t(int, ds, PAGE_SIZE);
+		data = kmap(page);
+		rr = drbd_recv(mdev, data, len);
+		if (FAULT_ACTIVE(mdev, DRBD_FAULT_RECEIVE)) {
+			dev_err(DEV, "Fault injection: Corrupting data on receive\n");
+			data[0] = data[0] ^ (unsigned long)-1;
+		}
 		kunmap(page);
-		if (rr != min_t(int, ds, PAGE_SIZE)) {
+		if (rr != len) {
 			drbd_free_ee(mdev, e);
 			dev_warn(DEV, "short read receiving data: read %d expected %d\n",
-			     rr, min_t(int, ds, PAGE_SIZE));
+			     rr, len);
 			return NULL;
 		}
 		ds -= rr;
 	}
 
 	if (dgs) {
-		drbd_csum(mdev, mdev->integrity_r_tfm, bio, dig_vv);
+		drbd_csum_ee(mdev, mdev->integrity_r_tfm, e, dig_vv);
 		if (memcmp(dig_in, dig_vv, dgs)) {
 			dev_err(DEV, "Digest integrity check FAILED.\n");
 			drbd_bcast_ee(mdev, "digest failed",
@@ -1330,7 +1440,10 @@ static int drbd_drain_block(struct drbd_conf *mdev, int data_size)
 	int rr, rv = 1;
 	void *data;
 
-	page = drbd_pp_alloc(mdev, 1);
+	if (!data_size)
+		return TRUE;
+
+	page = drbd_pp_alloc(mdev, 1, 1);
 
 	data = kmap(page);
 	while (data_size) {
@@ -1394,7 +1507,7 @@ static int recv_dless_read(struct drbd_conf *mdev, struct drbd_request *req,
 	}
 
 	if (dgs) {
-		drbd_csum(mdev, mdev->integrity_r_tfm, bio, dig_vv);
+		drbd_csum_bio(mdev, mdev->integrity_r_tfm, bio, dig_vv);
 		if (memcmp(dig_in, dig_vv, dgs)) {
 			dev_err(DEV, "Digest integrity check FAILED. Broken NICs?\n");
 			return 0;
@@ -1415,7 +1528,7 @@ static int e_end_resync_block(struct drbd_conf *mdev, struct drbd_work *w, int u
 
 	D_ASSERT(hlist_unhashed(&e->colision));
 
-	if (likely(drbd_bio_uptodate(e->private_bio))) {
+	if (likely((e->flags & EE_WAS_ERROR) == 0)) {
 		drbd_set_in_sync(mdev, sector, e->size);
 		ok = drbd_send_ack(mdev, P_RS_WRITE_ACK, e);
 	} else {
@@ -1434,30 +1547,28 @@ static int recv_resync_read(struct drbd_conf *mdev, sector_t sector, int data_si
 	struct drbd_epoch_entry *e;
 
 	e = read_in_block(mdev, ID_SYNCER, sector, data_size);
-	if (!e) {
-		put_ldev(mdev);
-		return FALSE;
-	}
+	if (!e)
+		goto fail;
 
 	dec_rs_pending(mdev);
 
-	e->private_bio->bi_end_io = drbd_endio_write_sec;
-	e->private_bio->bi_rw = WRITE;
-	e->w.cb = e_end_resync_block;
-
 	inc_unacked(mdev);
 	/* corresponding dec_unacked() in e_end_resync_block()
 	 * respective _drbd_clear_done_ee */
 
+	e->w.cb = e_end_resync_block;
+
 	spin_lock_irq(&mdev->req_lock);
 	list_add(&e->w.list, &mdev->sync_ee);
 	spin_unlock_irq(&mdev->req_lock);
 
-	drbd_generic_make_request(mdev, DRBD_FAULT_RS_WR, e->private_bio);
-	/* accounting done in endio */
+	if (drbd_submit_ee(mdev, e, WRITE, DRBD_FAULT_RS_WR) == 0)
+		return TRUE;
 
-	maybe_kick_lo(mdev);
-	return TRUE;
+	drbd_free_ee(mdev, e);
+fail:
+	put_ldev(mdev);
+	return FALSE;
 }
 
 static int receive_DataReply(struct drbd_conf *mdev, struct p_header *h)
@@ -1552,7 +1663,7 @@ static int e_end_block(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
 	}
 
 	if (mdev->net_conf->wire_protocol == DRBD_PROT_C) {
-		if (likely(drbd_bio_uptodate(e->private_bio))) {
+		if (likely((e->flags & EE_WAS_ERROR) == 0)) {
 			pcmd = (mdev->state.conn >= C_SYNC_SOURCE &&
 				mdev->state.conn <= C_PAUSED_SYNC_T &&
 				e->flags & EE_MAY_SET_IN_SYNC) ?
@@ -1698,7 +1809,6 @@ static int receive_Data(struct drbd_conf *mdev, struct p_header *h)
 		return FALSE;
 	}
 
-	e->private_bio->bi_end_io = drbd_endio_write_sec;
 	e->w.cb = e_end_block;
 
 	spin_lock(&mdev->epoch_lock);
@@ -1894,12 +2004,8 @@ static int receive_Data(struct drbd_conf *mdev, struct p_header *h)
 		drbd_al_begin_io(mdev, e->sector);
 	}
 
-	e->private_bio->bi_rw = rw;
-	drbd_generic_make_request(mdev, DRBD_FAULT_DT_WR, e->private_bio);
-	/* accounting done in endio */
-
-	maybe_kick_lo(mdev);
-	return TRUE;
+	if (drbd_submit_ee(mdev, e, rw, DRBD_FAULT_DT_WR) == 0)
+		return TRUE;
 
 out_interrupted:
 	/* yes, the epoch_size now is imbalanced.
@@ -1945,7 +2051,7 @@ static int receive_DataRequest(struct drbd_conf *mdev, struct p_header *h)
 			    "no local data.\n");
 		drbd_send_ack_rp(mdev, h->command == P_DATA_REQUEST ? P_NEG_DREPLY :
 				 P_NEG_RS_DREPLY , p);
-		return TRUE;
+		return drbd_drain_block(mdev, h->length - brps);
 	}
 
 	/* GFP_NOIO, because we must not cause arbitrary write-out: in a DRBD
@@ -1957,9 +2063,6 @@ static int receive_DataRequest(struct drbd_conf *mdev, struct p_header *h)
 		return FALSE;
 	}
 
-	e->private_bio->bi_rw = READ;
-	e->private_bio->bi_end_io = drbd_endio_read_sec;
-
 	switch (h->command) {
 	case P_DATA_REQUEST:
 		e->w.cb = w_e_end_data_req;
@@ -2053,10 +2156,8 @@ static int receive_DataRequest(struct drbd_conf *mdev, struct p_header *h)
 
 	inc_unacked(mdev);
 
-	drbd_generic_make_request(mdev, fault_type, e->private_bio);
-	maybe_kick_lo(mdev);
-
-	return TRUE;
+	if (drbd_submit_ee(mdev, e, READ, fault_type) == 0)
+		return TRUE;
 
 out_free_e:
 	kfree(di);
@@ -2473,6 +2574,9 @@ static enum drbd_conns drbd_sync_handshake(struct drbd_conf *mdev, enum drbd_rol
 		     hg > 0 ? "source" : "target");
 	}
 
+	if (abs(hg) == 100)
+		drbd_khelper(mdev, "initial-split-brain");
+
 	if (hg == 100 || (hg == -100 && mdev->net_conf->always_asbp)) {
 		int pcount = (mdev->state.role == R_PRIMARY)
 			   + (peer_role == R_PRIMARY);
@@ -2518,7 +2622,7 @@ static enum drbd_conns drbd_sync_handshake(struct drbd_conf *mdev, enum drbd_rol
 		 * after an attempted attach on a diskless node.
 		 * We just refuse to attach -- well, we drop the "connection"
 		 * to that disk, in a way... */
-		dev_alert(DEV, "Split-Brain detected, dropping connection!\n");
+		dev_alert(DEV, "Split-Brain detected but unresolved, dropping connection!\n");
 		drbd_khelper(mdev, "split-brain");
 		return C_MASK;
 	}
@@ -2849,7 +2953,7 @@ static int receive_sizes(struct drbd_conf *mdev, struct p_header *h)
 	unsigned int max_seg_s;
 	sector_t p_size, p_usize, my_usize;
 	int ldsc = 0; /* local disk size changed */
-	enum drbd_conns nconn;
+	enum dds_flags ddsf;
 
 	ERR_IF(h->length != (sizeof(*p)-sizeof(*h))) return FALSE;
 	if (drbd_recv(mdev, h->payload, h->length) != h->length)
@@ -2905,8 +3009,9 @@ static int receive_sizes(struct drbd_conf *mdev, struct p_header *h)
 	}
 #undef min_not_zero
 
+	ddsf = be16_to_cpu(p->dds_flags);
 	if (get_ldev(mdev)) {
-	  dd = drbd_determin_dev_size(mdev, 0);
+		dd = drbd_determin_dev_size(mdev, ddsf);
 		put_ldev(mdev);
 		if (dd == dev_size_error)
 			return FALSE;
@@ -2916,33 +3021,21 @@ static int receive_sizes(struct drbd_conf *mdev, struct p_header *h)
 		drbd_set_my_capacity(mdev, p_size);
 	}
 
-	if (mdev->p_uuid && mdev->state.conn <= C_CONNECTED && get_ldev(mdev)) {
-		nconn = drbd_sync_handshake(mdev,
-				mdev->state.peer, mdev->state.pdsk);
-		put_ldev(mdev);
-
-		if (nconn == C_MASK) {
-			drbd_force_state(mdev, NS(conn, C_DISCONNECTING));
-			return FALSE;
-		}
-
-		if (drbd_request_state(mdev, NS(conn, nconn)) < SS_SUCCESS) {
-			drbd_force_state(mdev, NS(conn, C_DISCONNECTING));
-			return FALSE;
-		}
-	}
-
 	if (get_ldev(mdev)) {
 		if (mdev->ldev->known_size != drbd_get_capacity(mdev->ldev->backing_bdev)) {
 			mdev->ldev->known_size = drbd_get_capacity(mdev->ldev->backing_bdev);
 			ldsc = 1;
 		}
 
-		max_seg_s = be32_to_cpu(p->max_segment_size);
+		if (mdev->agreed_pro_version < 94)
+			max_seg_s = be32_to_cpu(p->max_segment_size);
+		else /* drbd 8.3.8 onwards */
+			max_seg_s = DRBD_MAX_SEGMENT_SIZE;
+
 		if (max_seg_s != queue_max_segment_size(mdev->rq_queue))
 			drbd_setup_queue_param(mdev, max_seg_s);
 
-		drbd_setup_order_type(mdev, be32_to_cpu(p->queue_order_type));
+		drbd_setup_order_type(mdev, be16_to_cpu(p->queue_order_type));
 		put_ldev(mdev);
 	}
 
@@ -2951,14 +3044,17 @@ static int receive_sizes(struct drbd_conf *mdev, struct p_header *h)
 		    drbd_get_capacity(mdev->this_bdev) || ldsc) {
 			/* we have different sizes, probably peer
 			 * needs to know my new size... */
-			drbd_send_sizes(mdev, 0);
+			drbd_send_sizes(mdev, 0, ddsf);
 		}
 		if (test_and_clear_bit(RESIZE_PENDING, &mdev->flags) ||
 		    (dd == grew && mdev->state.conn == C_CONNECTED)) {
 			if (mdev->state.pdsk >= D_INCONSISTENT &&
-			    mdev->state.disk >= D_INCONSISTENT)
-				resync_after_online_grow(mdev);
-			else
+			    mdev->state.disk >= D_INCONSISTENT) {
+				if (ddsf & DDSF_NO_RESYNC)
+					dev_info(DEV, "Resync of new storage suppressed with --assume-clean\n");
+				else
+					resync_after_online_grow(mdev);
+			} else
 				set_bit(RESYNC_AFTER_NEG, &mdev->flags);
 		}
 	}
@@ -3490,6 +3586,92 @@ static int receive_UnplugRemote(struct drbd_conf *mdev, struct p_header *h)
 	return TRUE;
 }
 
+static void timeval_sub_us(struct timeval* tv, unsigned int us)
+{
+	tv->tv_sec -= us / 1000000;
+	us = us % 1000000;
+	if (tv->tv_usec > us) {
+		tv->tv_usec += 1000000;
+		tv->tv_sec--;
+	}
+	tv->tv_usec -= us;
+}
+
+static void got_delay_probe(struct drbd_conf *mdev, int from, struct p_delay_probe *p)
+{
+	struct delay_probe *dp;
+	struct list_head *le;
+	struct timeval now;
+	int seq_num;
+	int offset;
+	int data_delay;
+
+	seq_num = be32_to_cpu(p->seq_num);
+	offset  = be32_to_cpu(p->offset);
+
+	spin_lock(&mdev->peer_seq_lock);
+	if (!list_empty(&mdev->delay_probes)) {
+		if (from == USE_DATA_SOCKET)
+			le = mdev->delay_probes.next;
+		else
+			le = mdev->delay_probes.prev;
+
+		dp = list_entry(le, struct delay_probe, list);
+
+		if (dp->seq_num == seq_num) {
+			list_del(le);
+			spin_unlock(&mdev->peer_seq_lock);
+			do_gettimeofday(&now);
+			timeval_sub_us(&now, offset);
+			data_delay =
+				now.tv_usec - dp->time.tv_usec +
+				(now.tv_sec - dp->time.tv_sec) * 1000000;
+
+			if (data_delay > 0)
+				mdev->data_delay = data_delay;
+
+			kfree(dp);
+			return;
+		}
+
+		if (dp->seq_num > seq_num) {
+			spin_unlock(&mdev->peer_seq_lock);
+			dev_warn(DEV, "Previous allocation failure of struct delay_probe?\n");
+			return; /* Do not alloca a struct delay_probe.... */
+		}
+	}
+	spin_unlock(&mdev->peer_seq_lock);
+
+	dp = kmalloc(sizeof(struct delay_probe), GFP_NOIO);
+	if (!dp) {
+		dev_warn(DEV, "Failed to allocate a struct delay_probe, do not worry.\n");
+		return;
+	}
+
+	dp->seq_num = seq_num;
+	do_gettimeofday(&dp->time);
+	timeval_sub_us(&dp->time, offset);
+
+	spin_lock(&mdev->peer_seq_lock);
+	if (from == USE_DATA_SOCKET)
+		list_add(&dp->list, &mdev->delay_probes);
+	else
+		list_add_tail(&dp->list, &mdev->delay_probes);
+	spin_unlock(&mdev->peer_seq_lock);
+}
+
+static int receive_delay_probe(struct drbd_conf *mdev, struct p_header *h)
+{
+	struct p_delay_probe *p = (struct p_delay_probe *)h;
+
+	ERR_IF(h->length != (sizeof(*p)-sizeof(*h))) return FALSE;
+	if (drbd_recv(mdev, h->payload, h->length) != h->length)
+		return FALSE;
+
+	got_delay_probe(mdev, USE_DATA_SOCKET, p);
+	return TRUE;
+}
+
 typedef int (*drbd_cmd_handler_f)(struct drbd_conf *, struct p_header *);
 
 static drbd_cmd_handler_f drbd_default_handler[] = {
@@ -3513,6 +3695,7 @@ static drbd_cmd_handler_f drbd_default_handler[] = {
 	[P_OV_REQUEST]      = receive_DataRequest,
 	[P_OV_REPLY]        = receive_DataRequest,
 	[P_CSUM_RS_REQUEST]    = receive_DataRequest,
+	[P_DELAY_PROBE]     = receive_delay_probe,
 	/* anything missing from this table is in
 	 * the asender_tbl, see get_asender_cmd */
 	[P_MAX_CMD]	    = NULL,
@@ -3739,7 +3922,7 @@ static void drbd_disconnect(struct drbd_conf *mdev)
 		dev_info(DEV, "net_ee not empty, killed %u entries\n", i);
 	i = atomic_read(&mdev->pp_in_use);
 	if (i)
-		dev_info(DEV, "pp_in_use = %u, expected 0\n", i);
+		dev_info(DEV, "pp_in_use = %d, expected 0\n", i);
 
 	D_ASSERT(list_empty(&mdev->read_ee));
 	D_ASSERT(list_empty(&mdev->active_ee));
@@ -4232,7 +4415,6 @@ static int got_NegRSDReply(struct drbd_conf *mdev, struct p_header *h)
 
 	sector = be64_to_cpu(p->sector);
 	size = be32_to_cpu(p->blksize);
-	D_ASSERT(p->block_id == ID_SYNCER);
 
 	update_peer_seq(mdev, be32_to_cpu(p->seq_num));
 
@@ -4290,6 +4472,14 @@ static int got_OVResult(struct drbd_conf *mdev, struct p_header *h)
 	return TRUE;
 }
 
+static int got_delay_probe_m(struct drbd_conf *mdev, struct p_header *h)
+{
+	struct p_delay_probe *p = (struct p_delay_probe *)h;
+
+	got_delay_probe(mdev, USE_META_SOCKET, p);
+	return TRUE;
+}
+
 struct asender_cmd {
 	size_t pkt_size;
 	int (*process)(struct drbd_conf *mdev, struct p_header *h);
@@ -4314,6 +4504,7 @@ static struct asender_cmd *get_asender_cmd(int cmd)
 	[P_BARRIER_ACK]	    = { sizeof(struct p_barrier_ack), got_BarrierAck },
 	[P_STATE_CHG_REPLY] = { sizeof(struct p_req_state_reply), got_RqSReply },
 	[P_RS_IS_IN_SYNC]   = { sizeof(struct p_block_ack), got_IsInSync },
+	[P_DELAY_PROBE]     = { sizeof(struct p_delay_probe), got_delay_probe_m },
 	[P_MAX_CMD]	    = { 0, NULL },
 	};
 	if (cmd > P_MAX_CMD || asender_tbl[cmd].process == NULL)
diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c
index de81ab7b462..654f1ef5cbb 100644
--- a/drivers/block/drbd/drbd_req.c
+++ b/drivers/block/drbd/drbd_req.c
@@ -102,32 +102,7 @@ static void _req_is_done(struct drbd_conf *mdev, struct drbd_request *req, const
 		}
 	}
 
-	/* if it was a local io error, we want to notify our
-	 * peer about that, and see if we need to
-	 * detach the disk and stuff.
-	 * to avoid allocating some special work
-	 * struct, reuse the request. */
-
-	/* THINK
-	 * why do we do this not when we detect the error,
-	 * but delay it until it is "done", i.e. possibly
-	 * until the next barrier ack? */
-
-	if (rw == WRITE &&
-	    ((s & RQ_LOCAL_MASK) && !(s & RQ_LOCAL_OK))) {
-		if (!(req->w.list.next == LIST_POISON1 ||
-		      list_empty(&req->w.list))) {
-			/* DEBUG ASSERT only; if this triggers, we
-			 * probably corrupt the worker list here */
-			dev_err(DEV, "req->w.list.next = %p\n", req->w.list.next);
-			dev_err(DEV, "req->w.list.prev = %p\n", req->w.list.prev);
-		}
-		req->w.cb = w_io_error;
-		drbd_queue_work(&mdev->data.work, &req->w);
-		/* drbd_req_free() is done in w_io_error */
-	} else {
-		drbd_req_free(req);
-	}
+	drbd_req_free(req);
 }
 
 static void queue_barrier(struct drbd_conf *mdev)
@@ -453,9 +428,6 @@ void __req_mod(struct drbd_request *req, enum drbd_req_event what,
 		req->rq_state |= RQ_LOCAL_COMPLETED;
 		req->rq_state &= ~RQ_LOCAL_PENDING;
 
-		dev_alert(DEV, "Local WRITE failed sec=%llus size=%u\n",
-		      (unsigned long long)req->sector, req->size);
-		/* and now: check how to handle local io error. */
 		__drbd_chk_io_error(mdev, FALSE);
 		_req_may_be_done(req, m);
 		put_ldev(mdev);
@@ -475,22 +447,21 @@ void __req_mod(struct drbd_request *req, enum drbd_req_event what,
 		req->rq_state |= RQ_LOCAL_COMPLETED;
 		req->rq_state &= ~RQ_LOCAL_PENDING;
 
-		dev_alert(DEV, "Local READ failed sec=%llus size=%u\n",
-		      (unsigned long long)req->sector, req->size);
-		/* _req_mod(req,to_be_send); oops, recursion... */
 		D_ASSERT(!(req->rq_state & RQ_NET_MASK));
-		req->rq_state |= RQ_NET_PENDING;
-		inc_ap_pending(mdev);
 
 		__drbd_chk_io_error(mdev, FALSE);
 		put_ldev(mdev);
-		/* NOTE: if we have no connection,
-		 * or know the peer has no good data either,
-		 * then we don't actually need to "queue_for_net_read",
-		 * but we do so anyways, since the drbd_io_error()
-		 * and the potential state change to "Diskless"
-		 * needs to be done from process context */
 
+		/* no point in retrying if there is no good remote data,
+		 * or we have no connection. */
+		if (mdev->state.pdsk != D_UP_TO_DATE) {
+			_req_may_be_done(req, m);
+			break;
+		}
+
+		/* _req_mod(req,to_be_send); oops, recursion... */
+		req->rq_state |= RQ_NET_PENDING;
+		inc_ap_pending(mdev);
 		/* fall through: _req_mod(req,queue_for_net_read); */
 
 	case queue_for_net_read:
@@ -600,6 +571,9 @@ void __req_mod(struct drbd_request *req, enum drbd_req_event what,
 		_req_may_be_done(req, m);
 		break;
 
+	case read_retry_remote_canceled:
+		req->rq_state &= ~RQ_NET_QUEUED;
+		/* fall through, in case we raced with drbd_disconnect */
 	case connection_lost_while_pending:
 		/* transfer log cleanup after connection loss */
 		/* assert something? */
@@ -722,6 +696,7 @@ static int drbd_make_request_common(struct drbd_conf *mdev, struct bio *bio)
 	struct drbd_request *req;
 	int local, remote;
 	int err = -EIO;
+	int ret = 0;
 
 	/* allocate outside of all locks; */
 	req = drbd_req_new(mdev, bio);
@@ -784,7 +759,7 @@ static int drbd_make_request_common(struct drbd_conf *mdev, struct bio *bio)
 			    (mdev->state.pdsk == D_INCONSISTENT &&
 			     mdev->state.conn >= C_CONNECTED));
 
-	if (!(local || remote)) {
+	if (!(local || remote) && !mdev->state.susp) {
 		dev_err(DEV, "IO ERROR: neither local nor remote disk\n");
 		goto fail_free_complete;
 	}
@@ -810,6 +785,16 @@ allocate_barrier:
 	/* GOOD, everything prepared, grab the spin_lock */
 	spin_lock_irq(&mdev->req_lock);
 
+	if (mdev->state.susp) {
+		/* If we got suspended, use the retry mechanism of
+		   generic_make_request() to restart processing of this
+		   bio. In the next call to drbd_make_request_26
+		   we sleep in inc_ap_bio() */
+		ret = 1;
+		spin_unlock_irq(&mdev->req_lock);
+		goto fail_free_complete;
+	}
+
 	if (remote) {
 		remote = (mdev->state.pdsk == D_UP_TO_DATE ||
 			    (mdev->state.pdsk == D_INCONSISTENT &&
@@ -947,12 +932,14 @@ fail_and_free_req:
 		req->private_bio = NULL;
 		put_ldev(mdev);
 	}
-	bio_endio(bio, err);
+	if (!ret)
+		bio_endio(bio, err);
+
 	drbd_req_free(req);
 	dec_ap_bio(mdev);
 	kfree(b);
 
-	return 0;
+	return ret;
 }
 
 /* helper function for drbd_make_request
@@ -962,11 +949,6 @@ fail_and_free_req:
  */
 static int drbd_fail_request_early(struct drbd_conf *mdev, int is_write)
 {
-	/* Unconfigured */
-	if (mdev->state.conn == C_DISCONNECTING &&
-	    mdev->state.disk == D_DISKLESS)
-		return 1;
-
 	if (mdev->state.role != R_PRIMARY &&
 		(!allow_oos || is_write)) {
 		if (__ratelimit(&drbd_ratelimit_state)) {
@@ -1070,15 +1052,21 @@ int drbd_make_request_26(struct request_queue *q, struct bio *bio)
 
 		/* we need to get a "reference count" (ap_bio_cnt)
 		 * to avoid races with the disconnect/reconnect/suspend code.
-		 * In case we need to split the bio here, we need to get two references
+		 * In case we need to split the bio here, we need to get three references
 		 * atomically, otherwise we might deadlock when trying to submit the
 		 * second one! */
-		inc_ap_bio(mdev, 2);
+		inc_ap_bio(mdev, 3);
 
 		D_ASSERT(e_enr == s_enr + 1);
 
-		drbd_make_request_common(mdev, &bp->bio1);
-		drbd_make_request_common(mdev, &bp->bio2);
+		while (drbd_make_request_common(mdev, &bp->bio1))
+			inc_ap_bio(mdev, 1);
+
+		while (drbd_make_request_common(mdev, &bp->bio2))
+			inc_ap_bio(mdev, 1);
+
+		dec_ap_bio(mdev);
+
 		bio_pair_release(bp);
 	}
 	return 0;
@@ -1115,7 +1103,7 @@ int drbd_merge_bvec(struct request_queue *q, struct bvec_merge_data *bvm, struct
 	} else if (limit && get_ldev(mdev)) {
 		struct request_queue * const b =
 			mdev->ldev->backing_bdev->bd_disk->queue;
-		if (b->merge_bvec_fn && mdev->ldev->dc.use_bmbv) {
+		if (b->merge_bvec_fn) {
 			backing_limit = b->merge_bvec_fn(b, bvm, bvec);
 			limit = min(limit, backing_limit);
 		}
diff --git a/drivers/block/drbd/drbd_req.h b/drivers/block/drbd/drbd_req.h
index 16119d7056c..02d575d2451 100644
--- a/drivers/block/drbd/drbd_req.h
+++ b/drivers/block/drbd/drbd_req.h
@@ -91,6 +91,7 @@ enum drbd_req_event {
 	send_failed,
 	handed_over_to_network,
 	connection_lost_while_pending,
+	read_retry_remote_canceled,
 	recv_acked_by_peer,
 	write_acked_by_peer,
 	write_acked_by_peer_and_sis, /* and set_in_sync */
diff --git a/drivers/block/drbd/drbd_strings.c b/drivers/block/drbd/drbd_strings.c
index 76863e3f05b..85179e1fb50 100644
--- a/drivers/block/drbd/drbd_strings.c
+++ b/drivers/block/drbd/drbd_strings.c
@@ -70,7 +70,7 @@ static const char *drbd_disk_s_names[] = {
 
 static const char *drbd_state_sw_errors[] = {
 	[-SS_TWO_PRIMARIES] = "Multiple primaries not allowed by config",
-	[-SS_NO_UP_TO_DATE_DISK] = "Refusing to be Primary without at least one UpToDate disk",
+	[-SS_NO_UP_TO_DATE_DISK] = "Need access to UpToDate data",
 	[-SS_NO_LOCAL_DISK] = "Can not resync without local disk",
 	[-SS_NO_REMOTE_DISK] = "Can not resync without remote disk",
 	[-SS_CONNECTED_OUTDATES] = "Refusing to be Outdated while Connected",
diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c
index d48a1dfd7b2..b623ceee2a4 100644
--- a/drivers/block/drbd/drbd_worker.c
+++ b/drivers/block/drbd/drbd_worker.c
@@ -47,8 +47,7 @@ static int w_make_ov_request(struct drbd_conf *mdev, struct drbd_work *w, int ca
 
 /* defined here:
    drbd_md_io_complete
-   drbd_endio_write_sec
-   drbd_endio_read_sec
+   drbd_endio_sec
    drbd_endio_pri
 
  * more endio handlers:
@@ -85,27 +84,10 @@ void drbd_md_io_complete(struct bio *bio, int error)
 /* reads on behalf of the partner,
  * "submitted" by the receiver
  */
-void drbd_endio_read_sec(struct bio *bio, int error) __releases(local)
+void drbd_endio_read_sec_final(struct drbd_epoch_entry *e) __releases(local)
 {
 	unsigned long flags = 0;
-	struct drbd_epoch_entry *e = NULL;
-	struct drbd_conf *mdev;
-	int uptodate = bio_flagged(bio, BIO_UPTODATE);
-
-	e = bio->bi_private;
-	mdev = e->mdev;
-
-	if (error)
-		dev_warn(DEV, "read: error=%d s=%llus\n", error,
-				(unsigned long long)e->sector);
-	if (!error && !uptodate) {
-		dev_warn(DEV, "read: setting error to -EIO s=%llus\n",
-				(unsigned long long)e->sector);
-		/* strange behavior of some lower level drivers...
-		 * fail the request by clearing the uptodate flag,
-		 * but do not return any error?! */
-		error = -EIO;
-	}
+	struct drbd_conf *mdev = e->mdev;
 
 	D_ASSERT(e->block_id != ID_VACANT);
 
@@ -114,49 +96,38 @@ void drbd_endio_read_sec(struct bio *bio, int error) __releases(local)
 	list_del(&e->w.list);
 	if (list_empty(&mdev->read_ee))
 		wake_up(&mdev->ee_wait);
+	if (test_bit(__EE_WAS_ERROR, &e->flags))
+		__drbd_chk_io_error(mdev, FALSE);
 	spin_unlock_irqrestore(&mdev->req_lock, flags);
 
-	drbd_chk_io_error(mdev, error, FALSE);
 	drbd_queue_work(&mdev->data.work, &e->w);
 	put_ldev(mdev);
 }
 
+static int is_failed_barrier(int ee_flags)
+{
+	return (ee_flags & (EE_IS_BARRIER|EE_WAS_ERROR|EE_RESUBMITTED))
+			== (EE_IS_BARRIER|EE_WAS_ERROR);
+}
+
 /* writes on behalf of the partner, or resync writes,
- * "submitted" by the receiver.
- */
-void drbd_endio_write_sec(struct bio *bio, int error) __releases(local)
+ * "submitted" by the receiver, final stage.  */
+static void drbd_endio_write_sec_final(struct drbd_epoch_entry *e) __releases(local)
 {
 	unsigned long flags = 0;
-	struct drbd_epoch_entry *e = NULL;
-	struct drbd_conf *mdev;
+	struct drbd_conf *mdev = e->mdev;
 	sector_t e_sector;
 	int do_wake;
 	int is_syncer_req;
 	int do_al_complete_io;
-	int uptodate = bio_flagged(bio, BIO_UPTODATE);
-	int is_barrier = bio_rw_flagged(bio, BIO_RW_BARRIER);
-
-	e = bio->bi_private;
-	mdev = e->mdev;
 
-	if (error)
-		dev_warn(DEV, "write: error=%d s=%llus\n", error,
-				(unsigned long long)e->sector);
-	if (!error && !uptodate) {
-		dev_warn(DEV, "write: setting error to -EIO s=%llus\n",
-				(unsigned long long)e->sector);
-		/* strange behavior of some lower level drivers...
-		 * fail the request by clearing the uptodate flag,
-		 * but do not return any error?! */
-		error = -EIO;
-	}
-
-	/* error == -ENOTSUPP would be a better test,
-	 * alas it is not reliable */
-	if (error && is_barrier && e->flags & EE_IS_BARRIER) {
+	/* if this is a failed barrier request, disable use of barriers,
+	 * and schedule for resubmission */
+	if (is_failed_barrier(e->flags)) {
 		drbd_bump_write_ordering(mdev, WO_bdev_flush);
 		spin_lock_irqsave(&mdev->req_lock, flags);
 		list_del(&e->w.list);
+		e->flags = (e->flags & ~EE_WAS_ERROR) | EE_RESUBMITTED;
 		e->w.cb = w_e_reissue;
 		/* put_ldev actually happens below, once we come here again. */
 		__release(local);
@@ -167,17 +138,16 @@ void drbd_endio_write_sec(struct bio *bio, int error) __releases(local)
 
 	D_ASSERT(e->block_id != ID_VACANT);
 
-	spin_lock_irqsave(&mdev->req_lock, flags);
-	mdev->writ_cnt += e->size >> 9;
-	is_syncer_req = is_syncer_block_id(e->block_id);
-
 	/* after we moved e to done_ee,
 	 * we may no longer access it,
 	 * it may be freed/reused already!
 	 * (as soon as we release the req_lock) */
 	e_sector = e->sector;
 	do_al_complete_io = e->flags & EE_CALL_AL_COMPLETE_IO;
+	is_syncer_req = is_syncer_block_id(e->block_id);
 
+	spin_lock_irqsave(&mdev->req_lock, flags);
+	mdev->writ_cnt += e->size >> 9;
 	list_del(&e->w.list); /* has been on active_ee or sync_ee */
 	list_add_tail(&e->w.list, &mdev->done_ee);
 
@@ -190,7 +160,7 @@ void drbd_endio_write_sec(struct bio *bio, int error) __releases(local)
 		? list_empty(&mdev->sync_ee)
 		: list_empty(&mdev->active_ee);
 
-	if (error)
+	if (test_bit(__EE_WAS_ERROR, &e->flags))
 		__drbd_chk_io_error(mdev, FALSE);
 	spin_unlock_irqrestore(&mdev->req_lock, flags);
 
@@ -205,7 +175,42 @@ void drbd_endio_write_sec(struct bio *bio, int error) __releases(local)
 
 	wake_asender(mdev);
 	put_ldev(mdev);
+}
+
+/* writes on behalf of the partner, or resync writes,
+ * "submitted" by the receiver.
+ */
+void drbd_endio_sec(struct bio *bio, int error)
+{
+	struct drbd_epoch_entry *e = bio->bi_private;
+	struct drbd_conf *mdev = e->mdev;
+	int uptodate = bio_flagged(bio, BIO_UPTODATE);
+	int is_write = bio_data_dir(bio) == WRITE;
+
+	if (error)
+		dev_warn(DEV, "%s: error=%d s=%llus\n",
+				is_write ? "write" : "read", error,
+				(unsigned long long)e->sector);
+	if (!error && !uptodate) {
+		dev_warn(DEV, "%s: setting error to -EIO s=%llus\n",
+				is_write ? "write" : "read",
+				(unsigned long long)e->sector);
+		/* strange behavior of some lower level drivers...
+		 * fail the request by clearing the uptodate flag,
+		 * but do not return any error?! */
+		error = -EIO;
+	}
+
+	if (error)
+		set_bit(__EE_WAS_ERROR, &e->flags);
 
+	bio_put(bio); /* no need for the bio anymore */
+	if (atomic_dec_and_test(&e->pending_bios)) {
+		if (is_write)
+			drbd_endio_write_sec_final(e);
+		else
+			drbd_endio_read_sec_final(e);
+	}
 }
 
 /* read, readA or write requests on R_PRIMARY coming from drbd_make_request
@@ -219,9 +224,6 @@ void drbd_endio_pri(struct bio *bio, int error)
 	enum drbd_req_event what;
 	int uptodate = bio_flagged(bio, BIO_UPTODATE);
 
-	if (error)
-		dev_warn(DEV, "p %s: error=%d\n",
-			 bio_data_dir(bio) == WRITE ? "write" : "read", error);
 	if (!error && !uptodate) {
 		dev_warn(DEV, "p %s: setting error to -EIO\n",
 			 bio_data_dir(bio) == WRITE ? "write" : "read");
@@ -252,20 +254,6 @@ void drbd_endio_pri(struct bio *bio, int error)
 		complete_master_bio(mdev, &m);
 }
 
-int w_io_error(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
-{
-	struct drbd_request *req = container_of(w, struct drbd_request, w);
-
-	/* NOTE: mdev->ldev can be NULL by the time we get here! */
-	/* D_ASSERT(mdev->ldev->dc.on_io_error != EP_PASS_ON); */
-
-	/* the only way this callback is scheduled is from _req_may_be_done,
-	 * when it is done and had a local write error, see comments there */
-	drbd_req_free(req);
-
-	return TRUE;
-}
-
 int w_read_retry_remote(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
 {
 	struct drbd_request *req = container_of(w, struct drbd_request, w);
@@ -275,12 +263,9 @@ int w_read_retry_remote(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
 	 * to give the disk the chance to relocate that block */
 
 	spin_lock_irq(&mdev->req_lock);
-	if (cancel ||
-	    mdev->state.conn < C_CONNECTED ||
-	    mdev->state.pdsk <= D_INCONSISTENT) {
-		_req_mod(req, send_canceled);
+	if (cancel || mdev->state.pdsk != D_UP_TO_DATE) {
+		_req_mod(req, read_retry_remote_canceled);
 		spin_unlock_irq(&mdev->req_lock);
-		dev_alert(DEV, "WE ARE LOST. Local IO failure, no peer.\n");
 		return 1;
 	}
 	spin_unlock_irq(&mdev->req_lock);
@@ -295,7 +280,34 @@ int w_resync_inactive(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
 	return 1; /* Simply ignore this! */
 }
 
-void drbd_csum(struct drbd_conf *mdev, struct crypto_hash *tfm, struct bio *bio, void *digest)
+void drbd_csum_ee(struct drbd_conf *mdev, struct crypto_hash *tfm, struct drbd_epoch_entry *e, void *digest)
+{
+	struct hash_desc desc;
+	struct scatterlist sg;
+	struct page *page = e->pages;
+	struct page *tmp;
+	unsigned len;
+
+	desc.tfm = tfm;
+	desc.flags = 0;
+
+	sg_init_table(&sg, 1);
+	crypto_hash_init(&desc);
+
+	while ((tmp = page_chain_next(page))) {
+		/* all but the last page will be fully used */
+		sg_set_page(&sg, page, PAGE_SIZE, 0);
+		crypto_hash_update(&desc, &sg, sg.length);
+		page = tmp;
+	}
+	/* and now the last, possibly only partially used page */
+	len = e->size & (PAGE_SIZE - 1);
+	sg_set_page(&sg, page, len ?: PAGE_SIZE, 0);
+	crypto_hash_update(&desc, &sg, sg.length);
+	crypto_hash_final(&desc, digest);
+}
+
+void drbd_csum_bio(struct drbd_conf *mdev, struct crypto_hash *tfm, struct bio *bio, void *digest)
 {
 	struct hash_desc desc;
 	struct scatterlist sg;
@@ -329,11 +341,11 @@ static int w_e_send_csum(struct drbd_conf *mdev, struct drbd_work *w, int cancel
 		return 1;
 	}
 
-	if (likely(drbd_bio_uptodate(e->private_bio))) {
+	if (likely((e->flags & EE_WAS_ERROR) == 0)) {
 		digest_size = crypto_hash_digestsize(mdev->csums_tfm);
 		digest = kmalloc(digest_size, GFP_NOIO);
 		if (digest) {
-			drbd_csum(mdev, mdev->csums_tfm, e->private_bio, digest);
+			drbd_csum_ee(mdev, mdev->csums_tfm, e, digest);
 
 			inc_rs_pending(mdev);
 			ok = drbd_send_drequest_csum(mdev,
@@ -369,23 +381,21 @@ static int read_for_csum(struct drbd_conf *mdev, sector_t sector, int size)
 	/* GFP_TRY, because if there is no memory available right now, this may
 	 * be rescheduled for later. It is "only" background resync, after all. */
 	e = drbd_alloc_ee(mdev, DRBD_MAGIC+0xbeef, sector, size, GFP_TRY);
-	if (!e) {
-		put_ldev(mdev);
-		return 2;
-	}
+	if (!e)
+		goto fail;
 
 	spin_lock_irq(&mdev->req_lock);
 	list_add(&e->w.list, &mdev->read_ee);
 	spin_unlock_irq(&mdev->req_lock);
 
-	e->private_bio->bi_end_io = drbd_endio_read_sec;
-	e->private_bio->bi_rw = READ;
 	e->w.cb = w_e_send_csum;
+	if (drbd_submit_ee(mdev, e, READ, DRBD_FAULT_RS_RD) == 0)
+		return 1;
 
-	mdev->read_cnt += size >> 9;
-	drbd_generic_make_request(mdev, DRBD_FAULT_RS_RD, e->private_bio);
-
-	return 1;
+	drbd_free_ee(mdev, e);
+fail:
+	put_ldev(mdev);
+	return 2;
 }
 
 void resync_timer_fn(unsigned long data)
@@ -414,13 +424,25 @@ void resync_timer_fn(unsigned long data)
 		drbd_queue_work(&mdev->data.work, &mdev->resync_work);
 }
 
+static int calc_resync_rate(struct drbd_conf *mdev)
+{
+	int d = mdev->data_delay / 1000; /* us -> ms */
+	int td = mdev->sync_conf.throttle_th * 100;  /* 0.1s -> ms */
+	int hd = mdev->sync_conf.hold_off_th * 100;  /* 0.1s -> ms */
+	int cr = mdev->sync_conf.rate;
+
+	return d <= td ? cr :
+		d >= hd ? 0 :
+		cr + (cr * (td - d) / (hd - td));
+}
+
 int w_make_resync_request(struct drbd_conf *mdev,
 		struct drbd_work *w, int cancel)
 {
 	unsigned long bit;
 	sector_t sector;
 	const sector_t capacity = drbd_get_capacity(mdev->this_bdev);
-	int max_segment_size = queue_max_segment_size(mdev->rq_queue);
+	int max_segment_size;
 	int number, i, size, pe, mx;
 	int align, queued, sndbuf;
 
@@ -446,7 +468,13 @@ int w_make_resync_request(struct drbd_conf *mdev,
 		return 1;
 	}
 
-	number = SLEEP_TIME * mdev->sync_conf.rate / ((BM_BLOCK_SIZE/1024)*HZ);
+	/* starting with drbd 8.3.8, we can handle multi-bio EEs,
+	 * if it should be necessary */
+	max_segment_size = mdev->agreed_pro_version < 94 ?
+		queue_max_segment_size(mdev->rq_queue) : DRBD_MAX_SEGMENT_SIZE;
+
+	mdev->c_sync_rate = calc_resync_rate(mdev);
+	number = SLEEP_TIME * mdev->c_sync_rate  / ((BM_BLOCK_SIZE / 1024) * HZ);
 	pe = atomic_read(&mdev->rs_pending_cnt);
 
 	mutex_lock(&mdev->data.mutex);
@@ -509,12 +537,6 @@ next_sector:
 		 *
 		 * Additionally always align bigger requests, in order to
 		 * be prepared for all stripe sizes of software RAIDs.
-		 *
-		 * we _do_ care about the agreed-upon q->max_segment_size
-		 * here, as splitting up the requests on the other side is more
-		 * difficult.  the consequence is, that on lvm and md and other
-		 * "indirect" devices, this is dead code, since
-		 * q->max_segment_size will be PAGE_SIZE.
 		 */
 		align = 1;
 		for (;;) {
@@ -806,7 +828,7 @@ out:
 /* helper */
 static void move_to_net_ee_or_free(struct drbd_conf *mdev, struct drbd_epoch_entry *e)
 {
-	if (drbd_bio_has_active_page(e->private_bio)) {
+	if (drbd_ee_has_active_page(e)) {
 		/* This might happen if sendpage() has not finished */
 		spin_lock_irq(&mdev->req_lock);
 		list_add_tail(&e->w.list, &mdev->net_ee);
@@ -832,7 +854,7 @@ int w_e_end_data_req(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
 		return 1;
 	}
 
-	if (likely(drbd_bio_uptodate(e->private_bio))) {
+	if (likely((e->flags & EE_WAS_ERROR) == 0)) {
 		ok = drbd_send_block(mdev, P_DATA_REPLY, e);
 	} else {
 		if (__ratelimit(&drbd_ratelimit_state))
@@ -873,7 +895,7 @@ int w_e_end_rsdata_req(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
 		put_ldev(mdev);
 	}
 
-	if (likely(drbd_bio_uptodate(e->private_bio))) {
+	if (likely((e->flags & EE_WAS_ERROR) == 0)) {
 		if (likely(mdev->state.pdsk >= D_INCONSISTENT)) {
 			inc_rs_pending(mdev);
 			ok = drbd_send_block(mdev, P_RS_DATA_REPLY, e);
@@ -921,7 +943,7 @@ int w_e_end_csum_rs_req(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
 
 	di = (struct digest_info *)(unsigned long)e->block_id;
 
-	if (likely(drbd_bio_uptodate(e->private_bio))) {
+	if (likely((e->flags & EE_WAS_ERROR) == 0)) {
 		/* quick hack to try to avoid a race against reconfiguration.
 		 * a real fix would be much more involved,
 		 * introducing more locking mechanisms */
@@ -931,7 +953,7 @@ int w_e_end_csum_rs_req(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
 			digest = kmalloc(digest_size, GFP_NOIO);
 		}
 		if (digest) {
-			drbd_csum(mdev, mdev->csums_tfm, e->private_bio, digest);
+			drbd_csum_ee(mdev, mdev->csums_tfm, e, digest);
 			eq = !memcmp(digest, di->digest, digest_size);
 			kfree(digest);
 		}
@@ -973,14 +995,14 @@ int w_e_end_ov_req(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
 	if (unlikely(cancel))
 		goto out;
 
-	if (unlikely(!drbd_bio_uptodate(e->private_bio)))
+	if (unlikely((e->flags & EE_WAS_ERROR) != 0))
 		goto out;
 
 	digest_size = crypto_hash_digestsize(mdev->verify_tfm);
 	/* FIXME if this allocation fails, online verify will not terminate! */
 	digest = kmalloc(digest_size, GFP_NOIO);
 	if (digest) {
-		drbd_csum(mdev, mdev->verify_tfm, e->private_bio, digest);
+		drbd_csum_ee(mdev, mdev->verify_tfm, e, digest);
 		inc_rs_pending(mdev);
 		ok = drbd_send_drequest_csum(mdev, e->sector, e->size,
 					     digest, digest_size, P_OV_REPLY);
@@ -1029,11 +1051,11 @@ int w_e_end_ov_reply(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
 
 	di = (struct digest_info *)(unsigned long)e->block_id;
 
-	if (likely(drbd_bio_uptodate(e->private_bio))) {
+	if (likely((e->flags & EE_WAS_ERROR) == 0)) {
 		digest_size = crypto_hash_digestsize(mdev->verify_tfm);
 		digest = kmalloc(digest_size, GFP_NOIO);
 		if (digest) {
-			drbd_csum(mdev, mdev->verify_tfm, e->private_bio, digest);
+			drbd_csum_ee(mdev, mdev->verify_tfm, e, digest);
 
 			D_ASSERT(digest_size == di->digest_size);
 			eq = !memcmp(digest, di->digest, digest_size);
diff --git a/drivers/block/drbd/drbd_wrappers.h b/drivers/block/drbd/drbd_wrappers.h
index f93fa111ce5..defdb5013ea 100644
--- a/drivers/block/drbd/drbd_wrappers.h
+++ b/drivers/block/drbd/drbd_wrappers.h
@@ -18,23 +18,9 @@ static inline void drbd_set_my_capacity(struct drbd_conf *mdev,
 
 #define drbd_bio_uptodate(bio) bio_flagged(bio, BIO_UPTODATE)
 
-static inline int drbd_bio_has_active_page(struct bio *bio)
-{
-	struct bio_vec *bvec;
-	int i;
-
-	__bio_for_each_segment(bvec, bio, i, 0) {
-		if (page_count(bvec->bv_page) > 1)
-			return 1;
-	}
-
-	return 0;
-}
-
 /* bi_end_io handlers */
 extern void drbd_md_io_complete(struct bio *bio, int error);
-extern void drbd_endio_read_sec(struct bio *bio, int error);
-extern void drbd_endio_write_sec(struct bio *bio, int error);
+extern void drbd_endio_sec(struct bio *bio, int error);
 extern void drbd_endio_pri(struct bio *bio, int error);
 
 /*
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index a90e83c9be9..6120922f459 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -485,7 +485,7 @@ static int do_bio_filebacked(struct loop_device *lo, struct bio *bio)
 				goto out;
 			}
 
-			ret = vfs_fsync(file, file->f_path.dentry, 0);
+			ret = vfs_fsync(file, 0);
 			if (unlikely(ret)) {
 				ret = -EIO;
 				goto out;
@@ -495,7 +495,7 @@ static int do_bio_filebacked(struct loop_device *lo, struct bio *bio)
 		ret = lo_send(lo, bio, pos);
 
 		if (barrier && !ret) {
-			ret = vfs_fsync(file, file->f_path.dentry, 0);
+			ret = vfs_fsync(file, 0);
 			if (unlikely(ret))
 				ret = -EIO;
 		}
diff --git a/drivers/block/swim3.c b/drivers/block/swim3.c
index 59ca2b77b57..ed6fb91123a 100644
--- a/drivers/block/swim3.c
+++ b/drivers/block/swim3.c
@@ -1004,7 +1004,7 @@ static const struct block_device_operations floppy_fops = {
 
 static int swim3_add_device(struct macio_dev *mdev, int index)
 {
-	struct device_node *swim = mdev->ofdev.node;
+	struct device_node *swim = mdev->ofdev.dev.of_node;
 	struct floppy_state *fs = &floppy_states[index];
 	int rc = -EBUSY;
 
@@ -1159,8 +1159,10 @@ static struct of_device_id swim3_match[] =
 
 static struct macio_driver swim3_driver =
 {
-	.name 		= "swim3",
-	.match_table	= swim3_match,
+	.driver = {
+		.name 		= "swim3",
+		.of_match_table	= swim3_match,
+	},
 	.probe		= swim3_attach,
 #if 0
 	.suspend	= swim3_suspend,
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 2138a7ae050..258bc2ae288 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -50,7 +50,7 @@ static void blk_done(struct virtqueue *vq)
 	unsigned long flags;
 
 	spin_lock_irqsave(&vblk->lock, flags);
-	while ((vbr = vblk->vq->vq_ops->get_buf(vblk->vq, &len)) != NULL) {
+	while ((vbr = virtqueue_get_buf(vblk->vq, &len)) != NULL) {
 		int error;
 
 		switch (vbr->status) {
@@ -70,6 +70,8 @@ static void blk_done(struct virtqueue *vq)
 			vbr->req->sense_len = vbr->in_hdr.sense_len;
 			vbr->req->errors = vbr->in_hdr.errors;
 		}
+		if (blk_special_request(vbr->req))
+			vbr->req->errors = (error != 0);
 
 		__blk_end_request_all(vbr->req, error);
 		list_del(&vbr->list);
@@ -103,6 +105,11 @@ static bool do_req(struct request_queue *q, struct virtio_blk *vblk,
 		vbr->out_hdr.sector = 0;
 		vbr->out_hdr.ioprio = req_get_ioprio(vbr->req);
 		break;
+	case REQ_TYPE_SPECIAL:
+		vbr->out_hdr.type = VIRTIO_BLK_T_GET_ID;
+		vbr->out_hdr.sector = 0;
+		vbr->out_hdr.ioprio = req_get_ioprio(vbr->req);
+		break;
 	case REQ_TYPE_LINUX_BLOCK:
 		if (req->cmd[0] == REQ_LB_OP_FLUSH) {
 			vbr->out_hdr.type = VIRTIO_BLK_T_FLUSH;
@@ -151,7 +158,7 @@ static bool do_req(struct request_queue *q, struct virtio_blk *vblk,
 		}
 	}
 
-	if (vblk->vq->vq_ops->add_buf(vblk->vq, vblk->sg, out, in, vbr) < 0) {
+	if (virtqueue_add_buf(vblk->vq, vblk->sg, out, in, vbr) < 0) {
 		mempool_free(vbr, vblk->pool);
 		return false;
 	}
@@ -180,7 +187,7 @@ static void do_virtblk_request(struct request_queue *q)
 	}
 
 	if (issued)
-		vblk->vq->vq_ops->kick(vblk->vq);
+		virtqueue_kick(vblk->vq);
 }
 
 static void virtblk_prepare_flush(struct request_queue *q, struct request *req)
@@ -189,12 +196,45 @@ static void virtblk_prepare_flush(struct request_queue *q, struct request *req)
 	req->cmd[0] = REQ_LB_OP_FLUSH;
 }
 
+/* return id (s/n) string for *disk to *id_str
+ */
+static int virtblk_get_id(struct gendisk *disk, char *id_str)
+{
+	struct virtio_blk *vblk = disk->private_data;
+	struct request *req;
+	struct bio *bio;
+
+	bio = bio_map_kern(vblk->disk->queue, id_str, VIRTIO_BLK_ID_BYTES,
+			   GFP_KERNEL);
+	if (IS_ERR(bio))
+		return PTR_ERR(bio);
+
+	req = blk_make_request(vblk->disk->queue, bio, GFP_KERNEL);
+	if (IS_ERR(req)) {
+		bio_put(bio);
+		return PTR_ERR(req);
+	}
+
+	req->cmd_type = REQ_TYPE_SPECIAL;
+	return blk_execute_rq(vblk->disk->queue, vblk->disk, req, false);
+}
+
 static int virtblk_ioctl(struct block_device *bdev, fmode_t mode,
 			 unsigned cmd, unsigned long data)
 {
 	struct gendisk *disk = bdev->bd_disk;
 	struct virtio_blk *vblk = disk->private_data;
 
+	if (cmd == 0x56424944) { /* 'VBID' */
+		void __user *usr_data = (void __user *)data;
+		char id_str[VIRTIO_BLK_ID_BYTES];
+		int err;
+
+		err = virtblk_get_id(disk, id_str);
+		if (!err && copy_to_user(usr_data, id_str, VIRTIO_BLK_ID_BYTES))
+			err = -EFAULT;
+		return err;
+	}
 	/*
 	 * Only allow the generic SCSI ioctls if the host can support it.
 	 */
@@ -258,7 +298,9 @@ static int __devinit virtblk_probe(struct virtio_device *vdev)
 	err = virtio_config_val(vdev, VIRTIO_BLK_F_SEG_MAX,
 				offsetof(struct virtio_blk_config, seg_max),
 				&sg_elems);
-	if (err)
+
+	/* We need at least one SG element, whatever they say. */
+	if (err || !sg_elems)
 		sg_elems = 1;
 
 	/* We need an extra sg elements at head and tail. */
diff --git a/drivers/block/xsysace.c b/drivers/block/xsysace.c
index e1c95e208a6..a7b83c0a7eb 100644
--- a/drivers/block/xsysace.c
+++ b/drivers/block/xsysace.c
@@ -1198,10 +1198,10 @@ ace_of_probe(struct of_device *op, const struct of_device_id *match)
 	dev_dbg(&op->dev, "ace_of_probe(%p, %p)\n", op, match);
 
 	/* device id */
-	id = of_get_property(op->node, "port-number", NULL);
+	id = of_get_property(op->dev.of_node, "port-number", NULL);
 
 	/* physaddr */
-	rc = of_address_to_resource(op->node, 0, &res);
+	rc = of_address_to_resource(op->dev.of_node, 0, &res);
 	if (rc) {
 		dev_err(&op->dev, "invalid address\n");
 		return rc;
@@ -1209,11 +1209,11 @@ ace_of_probe(struct of_device *op, const struct of_device_id *match)
 	physaddr = res.start;
 
 	/* irq */
-	irq = irq_of_parse_and_map(op->node, 0);
+	irq = irq_of_parse_and_map(op->dev.of_node, 0);
 
 	/* bus width */
 	bus_width = ACE_BUS_WIDTH_16;
-	if (of_find_property(op->node, "8-bit", NULL))
+	if (of_find_property(op->dev.of_node, "8-bit", NULL))
 		bus_width = ACE_BUS_WIDTH_8;
 
 	/* Call the bus-independant setup code */
@@ -1237,13 +1237,12 @@ static const struct of_device_id ace_of_match[] __devinitconst = {
 MODULE_DEVICE_TABLE(of, ace_of_match);
 
 static struct of_platform_driver ace_of_driver = {
-	.owner = THIS_MODULE,
-	.name = "xsysace",
-	.match_table = ace_of_match,
 	.probe = ace_of_probe,
 	.remove = __devexit_p(ace_of_remove),
 	.driver = {
 		.name = "xsysace",
+		.owner = THIS_MODULE,
+		.of_match_table = ace_of_match,
 	},
 };
author	Jiri Kosina <jkosina@suse.cz>	2010-06-16 18:08:13 +0200
committer	Jiri Kosina <jkosina@suse.cz>	2010-06-16 18:08:13 +0200
commit	f1bbbb6912662b9f6070c5bfc4ca9eb1f06a9d5b (patch)
tree	c2c130a74be25b0b2dff992e1a195e2728bdaadd /drivers/block
parent	fd0961ff67727482bb20ca7e8ea97b83e9de2ddb (diff)
parent	7e27d6e778cd87b6f2415515d7127eba53fe5d02 (diff)