Merge branch 'for-linus' of git://neil.brown.name/md

* 'for-linus' of git://neil.brown.name/md:
  md: tidy up device searches in read_balance.
  md/raid1: fix some typos in comments.
  md/raid1: discard unused variable.
  md: unplug writes to external bitmaps.
  md: use separate bio pool for each md device.
  md: change type of first arg to sync_page_io.
  md/raid1: perform mem allocation before disabling writes during resync.
  md: use bio_kmalloc rather than bio_alloc when failure is acceptable.
  md: Fix possible deadlock with multiple mempool allocations.
  md: fix and update workqueue usage
  md: use sector_t in bitmap_get_counter
  md: remove md_mutex locking.
  md: Fix regression with raid1 arrays without persistent metadata.

1 files changed, 127 insertions, 35 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 225815197a3..4e957f3140a 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -57,8 +57,6 @@
 #define DEBUG 0
 #define dprintk(x...) ((void)(DEBUG && printk(x)))
 
-static DEFINE_MUTEX(md_mutex);
-
 #ifndef MODULE
 static void autostart_arrays(int part);
 #endif
@@ -69,6 +67,8 @@ static DEFINE_SPINLOCK(pers_lock);
 static void md_print_devices(void);
 
 static DECLARE_WAIT_QUEUE_HEAD(resync_wait);
+static struct workqueue_struct *md_wq;
+static struct workqueue_struct *md_misc_wq;
 
 #define MD_BUG(x...) { printk("md: bug in file %s, line %d\n", __FILE__, __LINE__); md_print_devices(); }
 
@@ -149,6 +149,72 @@ static const struct block_device_operations md_fops;
 
 static int start_readonly;
 
+/* bio_clone_mddev
+ * like bio_clone, but with a local bio set
+ */
+
+static void mddev_bio_destructor(struct bio *bio)
+{
+	mddev_t *mddev, **mddevp;
+
+	mddevp = (void*)bio;
+	mddev = mddevp[-1];
+
+	bio_free(bio, mddev->bio_set);
+}
+
+struct bio *bio_alloc_mddev(gfp_t gfp_mask, int nr_iovecs,
+			    mddev_t *mddev)
+{
+	struct bio *b;
+	mddev_t **mddevp;
+
+	if (!mddev || !mddev->bio_set)
+		return bio_alloc(gfp_mask, nr_iovecs);
+
+	b = bio_alloc_bioset(gfp_mask, nr_iovecs,
+			     mddev->bio_set);
+	if (!b)
+		return NULL;
+	mddevp = (void*)b;
+	mddevp[-1] = mddev;
+	b->bi_destructor = mddev_bio_destructor;
+	return b;
+}
+EXPORT_SYMBOL_GPL(bio_alloc_mddev);
+
+struct bio *bio_clone_mddev(struct bio *bio, gfp_t gfp_mask,
+			    mddev_t *mddev)
+{
+	struct bio *b;
+	mddev_t **mddevp;
+
+	if (!mddev || !mddev->bio_set)
+		return bio_clone(bio, gfp_mask);
+
+	b = bio_alloc_bioset(gfp_mask, bio->bi_max_vecs,
+			     mddev->bio_set);
+	if (!b)
+		return NULL;
+	mddevp = (void*)b;
+	mddevp[-1] = mddev;
+	b->bi_destructor = mddev_bio_destructor;
+	__bio_clone(b, bio);
+	if (bio_integrity(bio)) {
+		int ret;
+
+		ret = bio_integrity_clone(b, bio, gfp_mask, mddev->bio_set);
+
+		if (ret < 0) {
+			bio_put(b);
+			return NULL;
+		}
+	}
+
+	return b;
+}
+EXPORT_SYMBOL_GPL(bio_clone_mddev);
+
 /*
  * We have a system wide 'event count' that is incremented
  * on any 'interesting' event, and readers of /proc/mdstat
@@ -300,7 +366,7 @@ static void md_end_flush(struct bio *bio, int err)
 
 	if (atomic_dec_and_test(&mddev->flush_pending)) {
 		/* The pre-request flush has finished */
-		schedule_work(&mddev->flush_work);
+		queue_work(md_wq, &mddev->flush_work);
 	}
 	bio_put(bio);
 }
@@ -321,7 +387,7 @@ static void submit_flushes(mddev_t *mddev)
 			atomic_inc(&rdev->nr_pending);
 			atomic_inc(&rdev->nr_pending);
 			rcu_read_unlock();
-			bi = bio_alloc(GFP_KERNEL, 0);
+			bi = bio_alloc_mddev(GFP_KERNEL, 0, mddev);
 			bi->bi_end_io = md_end_flush;
 			bi->bi_private = rdev;
 			bi->bi_bdev = rdev->bdev;
@@ -369,7 +435,7 @@ void md_flush_request(mddev_t *mddev, struct bio *bio)
 	submit_flushes(mddev);
 
 	if (atomic_dec_and_test(&mddev->flush_pending))
-		schedule_work(&mddev->flush_work);
+		queue_work(md_wq, &mddev->flush_work);
 }
 EXPORT_SYMBOL(md_flush_request);
 
@@ -428,6 +494,8 @@ static void mddev_delayed_delete(struct work_struct *ws);
 
 static void mddev_put(mddev_t *mddev)
 {
+	struct bio_set *bs = NULL;
+
 	if (!atomic_dec_and_lock(&mddev->active, &all_mddevs_lock))
 		return;
 	if (!mddev->raid_disks && list_empty(&mddev->disks) &&
@@ -435,19 +503,22 @@ static void mddev_put(mddev_t *mddev)
 		/* Array is not configured at all, and not held active,
 		 * so destroy it */
 		list_del(&mddev->all_mddevs);
+		bs = mddev->bio_set;
+		mddev->bio_set = NULL;
 		if (mddev->gendisk) {
-			/* we did a probe so need to clean up.
-			 * Call schedule_work inside the spinlock
-			 * so that flush_scheduled_work() after
-			 * mddev_find will succeed in waiting for the
-			 * work to be done.
+			/* We did a probe so need to clean up.  Call
+			 * queue_work inside the spinlock so that
+			 * flush_workqueue() after mddev_find will
+			 * succeed in waiting for the work to be done.
 			 */
 			INIT_WORK(&mddev->del_work, mddev_delayed_delete);
-			schedule_work(&mddev->del_work);
+			queue_work(md_misc_wq, &mddev->del_work);
 		} else
 			kfree(mddev);
 	}
 	spin_unlock(&all_mddevs_lock);
+	if (bs)
+		bioset_free(bs);
 }
 
 void mddev_init(mddev_t *mddev)
@@ -691,7 +762,7 @@ void md_super_write(mddev_t *mddev, mdk_rdev_t *rdev,
 	 * if zero is reached.
 	 * If an error occurred, call md_error
 	 */
-	struct bio *bio = bio_alloc(GFP_NOIO, 1);
+	struct bio *bio = bio_alloc_mddev(GFP_NOIO, 1, mddev);
 
 	bio->bi_bdev = rdev->bdev;
 	bio->bi_sector = sector;
@@ -722,16 +793,16 @@ static void bi_complete(struct bio *bio, int error)
 	complete((struct completion*)bio->bi_private);
 }
 
-int sync_page_io(struct block_device *bdev, sector_t sector, int size,
-		   struct page *page, int rw)
+int sync_page_io(mdk_rdev_t *rdev, sector_t sector, int size,
+		 struct page *page, int rw)
 {
-	struct bio *bio = bio_alloc(GFP_NOIO, 1);
+	struct bio *bio = bio_alloc_mddev(GFP_NOIO, 1, rdev->mddev);
 	struct completion event;
 	int ret;
 
 	rw |= REQ_SYNC | REQ_UNPLUG;
 
-	bio->bi_bdev = bdev;
+	bio->bi_bdev = rdev->bdev;
 	bio->bi_sector = sector;
 	bio_add_page(bio, page, size, 0);
 	init_completion(&event);
@@ -757,7 +828,7 @@ static int read_disk_sb(mdk_rdev_t * rdev, int size)
 		return 0;
 
 
-	if (!sync_page_io(rdev->bdev, rdev->sb_start, size, rdev->sb_page, READ))
+	if (!sync_page_io(rdev, rdev->sb_start, size, rdev->sb_page, READ))
 		goto fail;
 	rdev->sb_loaded = 1;
 	return 0;
@@ -1850,7 +1921,7 @@ static void unbind_rdev_from_array(mdk_rdev_t * rdev)
 	synchronize_rcu();
 	INIT_WORK(&rdev->del_work, md_delayed_delete);
 	kobject_get(&rdev->kobj);
-	schedule_work(&rdev->del_work);
+	queue_work(md_misc_wq, &rdev->del_work);
 }
 
 /*
@@ -2108,6 +2179,8 @@ repeat:
 	if (!mddev->persistent) {
 		clear_bit(MD_CHANGE_CLEAN, &mddev->flags);
 		clear_bit(MD_CHANGE_DEVS, &mddev->flags);
+		if (!mddev->external)
+			clear_bit(MD_CHANGE_PENDING, &mddev->flags);
 		wake_up(&mddev->sb_wait);
 		return;
 	}
@@ -4192,10 +4265,10 @@ static int md_alloc(dev_t dev, char *name)
 	shift = partitioned ? MdpMinorShift : 0;
 	unit = MINOR(mddev->unit) >> shift;
 
-	/* wait for any previous instance if this device
-	 * to be completed removed (mddev_delayed_delete).
+	/* wait for any previous instance of this device to be
+	 * completely removed (mddev_delayed_delete).
 	 */
-	flush_scheduled_work();
+	flush_workqueue(md_misc_wq);
 
 	mutex_lock(&disks_mutex);
 	error = -EEXIST;
@@ -4378,6 +4451,9 @@ int md_run(mddev_t *mddev)
 		sysfs_notify_dirent_safe(rdev->sysfs_state);
 	}
 
+	if (mddev->bio_set == NULL)
+		mddev->bio_set = bioset_create(BIO_POOL_SIZE, sizeof(mddev));
+
 	spin_lock(&pers_lock);
 	pers = find_pers(mddev->level, mddev->clevel);
 	if (!pers || !try_module_get(pers->owner)) {
@@ -5885,16 +5961,14 @@ static int md_open(struct block_device *bdev, fmode_t mode)
 	mddev_t *mddev = mddev_find(bdev->bd_dev);
 	int err;
 
-	mutex_lock(&md_mutex);
 	if (mddev->gendisk != bdev->bd_disk) {
 		/* we are racing with mddev_put which is discarding this
 		 * bd_disk.
 		 */
 		mddev_put(mddev);
 		/* Wait until bdev->bd_disk is definitely gone */
-		flush_scheduled_work();
+		flush_workqueue(md_misc_wq);
 		/* Then retry the open from the top */
-		mutex_unlock(&md_mutex);
 		return -ERESTARTSYS;
 	}
 	BUG_ON(mddev != bdev->bd_disk->private_data);
@@ -5908,7 +5982,6 @@ static int md_open(struct block_device *bdev, fmode_t mode)
 
 	check_disk_size_change(mddev->gendisk, bdev);
  out:
-	mutex_unlock(&md_mutex);
 	return err;
 }
 
@@ -5917,10 +5990,8 @@ static int md_release(struct gendisk *disk, fmode_t mode)
  	mddev_t *mddev = disk->private_data;
 
 	BUG_ON(!mddev);
-	mutex_lock(&md_mutex);
 	atomic_dec(&mddev->openers);
 	mddev_put(mddev);
-	mutex_unlock(&md_mutex);
 
 	return 0;
 }
@@ -6052,7 +6123,7 @@ void md_error(mddev_t *mddev, mdk_rdev_t *rdev)
 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
 	md_wakeup_thread(mddev->thread);
 	if (mddev->event_work.func)
-		schedule_work(&mddev->event_work);
+		queue_work(md_misc_wq, &mddev->event_work);
 	md_new_event_inintr(mddev);
 }
 
@@ -7212,12 +7283,23 @@ static void md_geninit(void)
 
 static int __init md_init(void)
 {
-	if (register_blkdev(MD_MAJOR, "md"))
-		return -1;
-	if ((mdp_major=register_blkdev(0, "mdp"))<=0) {
-		unregister_blkdev(MD_MAJOR, "md");
-		return -1;
-	}
+	int ret = -ENOMEM;
+
+	md_wq = alloc_workqueue("md", WQ_RESCUER, 0);
+	if (!md_wq)
+		goto err_wq;
+
+	md_misc_wq = alloc_workqueue("md_misc", 0, 0);
+	if (!md_misc_wq)
+		goto err_misc_wq;
+
+	if ((ret = register_blkdev(MD_MAJOR, "md")) < 0)
+		goto err_md;
+
+	if ((ret = register_blkdev(0, "mdp")) < 0)
+		goto err_mdp;
+	mdp_major = ret;
+
 	blk_register_region(MKDEV(MD_MAJOR, 0), 1UL<<MINORBITS, THIS_MODULE,
 			    md_probe, NULL, NULL);
 	blk_register_region(MKDEV(mdp_major, 0), 1UL<<MINORBITS, THIS_MODULE,
@@ -7228,8 +7310,16 @@ static int __init md_init(void)
 
 	md_geninit();
 	return 0;
-}
 
+err_mdp:
+	unregister_blkdev(MD_MAJOR, "md");
+err_md:
+	destroy_workqueue(md_misc_wq);
+err_misc_wq:
+	destroy_workqueue(md_wq);
+err_wq:
+	return ret;
+}
 
 #ifndef MODULE
 
@@ -7316,6 +7406,8 @@ static __exit void md_exit(void)
 		export_array(mddev);
 		mddev->hold_active = 0;
 	}
+	destroy_workqueue(md_misc_wq);
+	destroy_workqueue(md_wq);
 }
 
 subsys_initcall(md_init);