Merge 3.10-rc6 into char-misc-next

We want the fixes in here.

9 files changed, 149 insertions, 150 deletions

diff --git a/drivers/md/bcache/Kconfig b/drivers/md/bcache/Kconfig
index 05c220d05e23..f950c9d29f3e 100644
--- a/drivers/md/bcache/Kconfig
+++ b/drivers/md/bcache/Kconfig
@@ -1,7 +1,6 @@
 
 config BCACHE
 	tristate "Block device as cache"
-	select CLOSURES
 	---help---
 	Allows a block device to be used as cache for other devices; uses
 	a btree for indexing and the layout is optimized for SSDs.
diff --git a/drivers/md/bcache/bcache.h b/drivers/md/bcache/bcache.h
index 340146d7c17f..d3e15b42a4ab 100644
--- a/drivers/md/bcache/bcache.h
+++ b/drivers/md/bcache/bcache.h
@@ -1241,7 +1241,7 @@ void bch_cache_set_stop(struct cache_set *);
 struct cache_set *bch_cache_set_alloc(struct cache_sb *);
 void bch_btree_cache_free(struct cache_set *);
 int bch_btree_cache_alloc(struct cache_set *);
-void bch_writeback_init_cached_dev(struct cached_dev *);
+void bch_cached_dev_writeback_init(struct cached_dev *);
 void bch_moving_init_cache_set(struct cache_set *);
 
 void bch_cache_allocator_exit(struct cache *ca);
diff --git a/drivers/md/bcache/stats.c b/drivers/md/bcache/stats.c
index 64e679449c2a..b8730e714d69 100644
--- a/drivers/md/bcache/stats.c
+++ b/drivers/md/bcache/stats.c
@@ -93,24 +93,6 @@ static struct attribute *bch_stats_files[] = {
 };
 static KTYPE(bch_stats);
 
-static void scale_accounting(unsigned long data);
-
-void bch_cache_accounting_init(struct cache_accounting *acc,
-			       struct closure *parent)
-{
-	kobject_init(&acc->total.kobj,		&bch_stats_ktype);
-	kobject_init(&acc->five_minute.kobj,	&bch_stats_ktype);
-	kobject_init(&acc->hour.kobj,		&bch_stats_ktype);
-	kobject_init(&acc->day.kobj,		&bch_stats_ktype);
-
-	closure_init(&acc->cl, parent);
-	init_timer(&acc->timer);
-	acc->timer.expires	= jiffies + accounting_delay;
-	acc->timer.data		= (unsigned long) acc;
-	acc->timer.function	= scale_accounting;
-	add_timer(&acc->timer);
-}
-
 int bch_cache_accounting_add_kobjs(struct cache_accounting *acc,
 				   struct kobject *parent)
 {
@@ -244,3 +226,19 @@ void bch_mark_sectors_bypassed(struct search *s, int sectors)
 	atomic_add(sectors, &dc->accounting.collector.sectors_bypassed);
 	atomic_add(sectors, &s->op.c->accounting.collector.sectors_bypassed);
 }
+
+void bch_cache_accounting_init(struct cache_accounting *acc,
+			       struct closure *parent)
+{
+	kobject_init(&acc->total.kobj,		&bch_stats_ktype);
+	kobject_init(&acc->five_minute.kobj,	&bch_stats_ktype);
+	kobject_init(&acc->hour.kobj,		&bch_stats_ktype);
+	kobject_init(&acc->day.kobj,		&bch_stats_ktype);
+
+	closure_init(&acc->cl, parent);
+	init_timer(&acc->timer);
+	acc->timer.expires	= jiffies + accounting_delay;
+	acc->timer.data		= (unsigned long) acc;
+	acc->timer.function	= scale_accounting;
+	add_timer(&acc->timer);
+}
diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index c8046bc4aa57..f88e2b653a3f 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -634,11 +634,10 @@ static int open_dev(struct block_device *b, fmode_t mode)
 	return 0;
 }
 
-static int release_dev(struct gendisk *b, fmode_t mode)
+static void release_dev(struct gendisk *b, fmode_t mode)
 {
 	struct bcache_device *d = b->private_data;
 	closure_put(&d->cl);
-	return 0;
 }
 
 static int ioctl_dev(struct block_device *b, fmode_t mode,
@@ -732,8 +731,7 @@ static void bcache_device_free(struct bcache_device *d)
 
 	if (d->c)
 		bcache_device_detach(d);
-
-	if (d->disk)
+	if (d->disk && d->disk->flags & GENHD_FL_UP)
 		del_gendisk(d->disk);
 	if (d->disk && d->disk->queue)
 		blk_cleanup_queue(d->disk->queue);
@@ -756,12 +754,9 @@ static int bcache_device_init(struct bcache_device *d, unsigned block_size)
 	if (!(d->bio_split = bioset_create(4, offsetof(struct bbio, bio))) ||
 	    !(d->unaligned_bvec = mempool_create_kmalloc_pool(1,
 				sizeof(struct bio_vec) * BIO_MAX_PAGES)) ||
-	    bio_split_pool_init(&d->bio_split_hook))
-
-		return -ENOMEM;
-
-	d->disk = alloc_disk(1);
-	if (!d->disk)
+	    bio_split_pool_init(&d->bio_split_hook) ||
+	    !(d->disk = alloc_disk(1)) ||
+	    !(q = blk_alloc_queue(GFP_KERNEL)))
 		return -ENOMEM;
 
 	snprintf(d->disk->disk_name, DISK_NAME_LEN, "bcache%i", bcache_minor);
@@ -771,10 +766,6 @@ static int bcache_device_init(struct bcache_device *d, unsigned block_size)
 	d->disk->fops		= &bcache_ops;
 	d->disk->private_data	= d;
 
-	q = blk_alloc_queue(GFP_KERNEL);
-	if (!q)
-		return -ENOMEM;
-
 	blk_queue_make_request(q, NULL);
 	d->disk->queue			= q;
 	q->queuedata			= d;
@@ -999,14 +990,17 @@ static void cached_dev_free(struct closure *cl)
 
 	mutex_lock(&bch_register_lock);
 
-	bd_unlink_disk_holder(dc->bdev, dc->disk.disk);
+	if (atomic_read(&dc->running))
+		bd_unlink_disk_holder(dc->bdev, dc->disk.disk);
 	bcache_device_free(&dc->disk);
 	list_del(&dc->list);
 
 	mutex_unlock(&bch_register_lock);
 
 	if (!IS_ERR_OR_NULL(dc->bdev)) {
-		blk_sync_queue(bdev_get_queue(dc->bdev));
+		if (dc->bdev->bd_disk)
+			blk_sync_queue(bdev_get_queue(dc->bdev));
+
 		blkdev_put(dc->bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 	}
 
@@ -1028,73 +1022,67 @@ static void cached_dev_flush(struct closure *cl)
 
 static int cached_dev_init(struct cached_dev *dc, unsigned block_size)
 {
-	int err;
+	int ret;
 	struct io *io;
-
-	closure_init(&dc->disk.cl, NULL);
-	set_closure_fn(&dc->disk.cl, cached_dev_flush, system_wq);
+	struct request_queue *q = bdev_get_queue(dc->bdev);
 
 	__module_get(THIS_MODULE);
 	INIT_LIST_HEAD(&dc->list);
+	closure_init(&dc->disk.cl, NULL);
+	set_closure_fn(&dc->disk.cl, cached_dev_flush, system_wq);
 	kobject_init(&dc->disk.kobj, &bch_cached_dev_ktype);
-
-	bch_cache_accounting_init(&dc->accounting, &dc->disk.cl);
-
-	err = bcache_device_init(&dc->disk, block_size);
-	if (err)
-		goto err;
-
-	spin_lock_init(&dc->io_lock);
-	closure_init_unlocked(&dc->sb_write);
 	INIT_WORK(&dc->detach, cached_dev_detach_finish);
+	closure_init_unlocked(&dc->sb_write);
+	INIT_LIST_HEAD(&dc->io_lru);
+	spin_lock_init(&dc->io_lock);
+	bch_cache_accounting_init(&dc->accounting, &dc->disk.cl);
 
 	dc->sequential_merge		= true;
 	dc->sequential_cutoff		= 4 << 20;
 
-	INIT_LIST_HEAD(&dc->io_lru);
-	dc->sb_bio.bi_max_vecs	= 1;
-	dc->sb_bio.bi_io_vec	= dc->sb_bio.bi_inline_vecs;
-
 	for (io = dc->io; io < dc->io + RECENT_IO; io++) {
 		list_add(&io->lru, &dc->io_lru);
 		hlist_add_head(&io->hash, dc->io_hash + RECENT_IO);
 	}
 
-	bch_writeback_init_cached_dev(dc);
+	ret = bcache_device_init(&dc->disk, block_size);
+	if (ret)
+		return ret;
+
+	set_capacity(dc->disk.disk,
+		     dc->bdev->bd_part->nr_sects - dc->sb.data_offset);
+
+	dc->disk.disk->queue->backing_dev_info.ra_pages =
+		max(dc->disk.disk->queue->backing_dev_info.ra_pages,
+		    q->backing_dev_info.ra_pages);
+
+	bch_cached_dev_request_init(dc);
+	bch_cached_dev_writeback_init(dc);
 	return 0;
-err:
-	bcache_device_stop(&dc->disk);
-	return err;
 }
 
 /* Cached device - bcache superblock */
 
-static const char *register_bdev(struct cache_sb *sb, struct page *sb_page,
+static void register_bdev(struct cache_sb *sb, struct page *sb_page,
 				 struct block_device *bdev,
 				 struct cached_dev *dc)
 {
 	char name[BDEVNAME_SIZE];
 	const char *err = "cannot allocate memory";
-	struct gendisk *g;
 	struct cache_set *c;
 
-	if (!dc || cached_dev_init(dc, sb->block_size << 9) != 0)
-		return err;
-
 	memcpy(&dc->sb, sb, sizeof(struct cache_sb));
-	dc->sb_bio.bi_io_vec[0].bv_page = sb_page;
 	dc->bdev = bdev;
 	dc->bdev->bd_holder = dc;
 
-	g = dc->disk.disk;
-
-	set_capacity(g, dc->bdev->bd_part->nr_sects - dc->sb.data_offset);
-
-	g->queue->backing_dev_info.ra_pages =
-		max(g->queue->backing_dev_info.ra_pages,
-		    bdev->bd_queue->backing_dev_info.ra_pages);
+	bio_init(&dc->sb_bio);
+	dc->sb_bio.bi_max_vecs	= 1;
+	dc->sb_bio.bi_io_vec	= dc->sb_bio.bi_inline_vecs;
+	dc->sb_bio.bi_io_vec[0].bv_page = sb_page;
+	get_page(sb_page);
 
-	bch_cached_dev_request_init(dc);
+	if (cached_dev_init(dc, sb->block_size << 9))
+		goto err;
 
 	err = "error creating kobject";
 	if (kobject_add(&dc->disk.kobj, &part_to_dev(bdev->bd_part)->kobj,
@@ -1103,6 +1091,8 @@ static const char *register_bdev(struct cache_sb *sb, struct page *sb_page,
 	if (bch_cache_accounting_add_kobjs(&dc->accounting, &dc->disk.kobj))
 		goto err;
 
+	pr_info("registered backing device %s", bdevname(bdev, name));
+
 	list_add(&dc->list, &uncached_devices);
 	list_for_each_entry(c, &bch_cache_sets, list)
 		bch_cached_dev_attach(dc, c);
@@ -1111,15 +1101,10 @@ static const char *register_bdev(struct cache_sb *sb, struct page *sb_page,
 	    BDEV_STATE(&dc->sb) == BDEV_STATE_STALE)
 		bch_cached_dev_run(dc);
 
-	return NULL;
+	return;
 err:
-	kobject_put(&dc->disk.kobj);
 	pr_notice("error opening %s: %s", bdevname(bdev, name), err);
-	/*
-	 * Return NULL instead of an error because kobject_put() cleans
-	 * everything up
-	 */
-	return NULL;
+	bcache_device_stop(&dc->disk);
 }
 
 /* Flash only volumes */
@@ -1717,20 +1702,11 @@ static int cache_alloc(struct cache_sb *sb, struct cache *ca)
 	size_t free;
 	struct bucket *b;
 
-	if (!ca)
-		return -ENOMEM;
-
 	__module_get(THIS_MODULE);
 	kobject_init(&ca->kobj, &bch_cache_ktype);
 
-	memcpy(&ca->sb, sb, sizeof(struct cache_sb));
-
 	INIT_LIST_HEAD(&ca->discards);
 
-	bio_init(&ca->sb_bio);
-	ca->sb_bio.bi_max_vecs	= 1;
-	ca->sb_bio.bi_io_vec	= ca->sb_bio.bi_inline_vecs;
-
 	bio_init(&ca->journal.bio);
 	ca->journal.bio.bi_max_vecs = 8;
 	ca->journal.bio.bi_io_vec = ca->journal.bio.bi_inline_vecs;
@@ -1742,18 +1718,17 @@ static int cache_alloc(struct cache_sb *sb, struct cache *ca)
 	    !init_fifo(&ca->free_inc,	free << 2, GFP_KERNEL) ||
 	    !init_fifo(&ca->unused,	free << 2, GFP_KERNEL) ||
 	    !init_heap(&ca->heap,	free << 3, GFP_KERNEL) ||
-	    !(ca->buckets	= vmalloc(sizeof(struct bucket) *
+	    !(ca->buckets	= vzalloc(sizeof(struct bucket) *
 					  ca->sb.nbuckets)) ||
 	    !(ca->prio_buckets	= kzalloc(sizeof(uint64_t) * prio_buckets(ca) *
 					  2, GFP_KERNEL)) ||
 	    !(ca->disk_buckets	= alloc_bucket_pages(GFP_KERNEL, ca)) ||
 	    !(ca->alloc_workqueue = alloc_workqueue("bch_allocator", 0, 1)) ||
 	    bio_split_pool_init(&ca->bio_split_hook))
-		goto err;
+		return -ENOMEM;
 
 	ca->prio_last_buckets = ca->prio_buckets + prio_buckets(ca);
 
-	memset(ca->buckets, 0, ca->sb.nbuckets * sizeof(struct bucket));
 	for_each_bucket(b, ca)
 		atomic_set(&b->pin, 0);
 
@@ -1766,22 +1741,28 @@ err:
 	return -ENOMEM;
 }
 
-static const char *register_cache(struct cache_sb *sb, struct page *sb_page,
+static void register_cache(struct cache_sb *sb, struct page *sb_page,
 				  struct block_device *bdev, struct cache *ca)
 {
 	char name[BDEVNAME_SIZE];
 	const char *err = "cannot allocate memory";
 
-	if (cache_alloc(sb, ca) != 0)
-		return err;
-
-	ca->sb_bio.bi_io_vec[0].bv_page = sb_page;
+	memcpy(&ca->sb, sb, sizeof(struct cache_sb));
 	ca->bdev = bdev;
 	ca->bdev->bd_holder = ca;
 
+	bio_init(&ca->sb_bio);
+	ca->sb_bio.bi_max_vecs	= 1;
+	ca->sb_bio.bi_io_vec	= ca->sb_bio.bi_inline_vecs;
+	ca->sb_bio.bi_io_vec[0].bv_page = sb_page;
+	get_page(sb_page);
+
 	if (blk_queue_discard(bdev_get_queue(ca->bdev)))
 		ca->discard = CACHE_DISCARD(&ca->sb);
 
+	if (cache_alloc(sb, ca) != 0)
+		goto err;
+
 	err = "error creating kobject";
 	if (kobject_add(&ca->kobj, &part_to_dev(bdev->bd_part)->kobj, "bcache"))
 		goto err;
@@ -1791,15 +1772,10 @@ static const char *register_cache(struct cache_sb *sb, struct page *sb_page,
 		goto err;
 
 	pr_info("registered cache device %s", bdevname(bdev, name));
-
-	return NULL;
+	return;
 err:
+	pr_notice("error opening %s: %s", bdevname(bdev, name), err);
 	kobject_put(&ca->kobj);
-	pr_info("error opening %s: %s", bdevname(bdev, name), err);
-	/* Return NULL instead of an error because kobject_put() cleans
-	 * everything up
-	 */
-	return NULL;
 }
 
 /* Global interfaces/init */
@@ -1833,12 +1809,15 @@ static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr,
 	bdev = blkdev_get_by_path(strim(path),
 				  FMODE_READ|FMODE_WRITE|FMODE_EXCL,
 				  sb);
-	if (bdev == ERR_PTR(-EBUSY))
-		err = "device busy";
-
-	if (IS_ERR(bdev) ||
-	    set_blocksize(bdev, 4096))
+	if (IS_ERR(bdev)) {
+		if (bdev == ERR_PTR(-EBUSY))
+			err = "device busy";
 		goto err;
+	}
+
+	err = "failed to set blocksize";
+	if (set_blocksize(bdev, 4096))
+		goto err_close;
 
 	err = read_super(sb, bdev, &sb_page);
 	if (err)
@@ -1846,33 +1825,33 @@ static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr,
 
 	if (SB_IS_BDEV(sb)) {
 		struct cached_dev *dc = kzalloc(sizeof(*dc), GFP_KERNEL);
+		if (!dc)
+			goto err_close;
 
-		err = register_bdev(sb, sb_page, bdev, dc);
+		register_bdev(sb, sb_page, bdev, dc);
 	} else {
 		struct cache *ca = kzalloc(sizeof(*ca), GFP_KERNEL);
+		if (!ca)
+			goto err_close;
 
-		err = register_cache(sb, sb_page, bdev, ca);
+		register_cache(sb, sb_page, bdev, ca);
 	}
-
-	if (err) {
-		/* register_(bdev|cache) will only return an error if they
-		 * didn't get far enough to create the kobject - if they did,
-		 * the kobject destructor will do this cleanup.
-		 */
+out:
+	if (sb_page)
 		put_page(sb_page);
-err_close:
-		blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
-err:
-		if (attr != &ksysfs_register_quiet)
-			pr_info("error opening %s: %s", path, err);
-		ret = -EINVAL;
-	}
-
 	kfree(sb);
 	kfree(path);
 	mutex_unlock(&bch_register_lock);
 	module_put(THIS_MODULE);
 	return ret;
+
+err_close:
+	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
+err:
+	if (attr != &ksysfs_register_quiet)
+		pr_info("error opening %s: %s", path, err);
+	ret = -EINVAL;
+	goto out;
 }
 
 static int bcache_reboot(struct notifier_block *n, unsigned long code, void *x)
diff --git a/drivers/md/bcache/writeback.c b/drivers/md/bcache/writeback.c
index 93e7e31a4bd3..2714ed3991d1 100644
--- a/drivers/md/bcache/writeback.c
+++ b/drivers/md/bcache/writeback.c
@@ -375,7 +375,7 @@ err:
 	refill_dirty(cl);
 }
 
-void bch_writeback_init_cached_dev(struct cached_dev *dc)
+void bch_cached_dev_writeback_init(struct cached_dev *dc)
 {
 	closure_init_unlocked(&dc->writeback);
 	init_rwsem(&dc->writeback_lock);
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 681d1099a2d5..9b82377a833b 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -5268,8 +5268,8 @@ static void md_clean(struct mddev *mddev)
 
 static void __md_stop_writes(struct mddev *mddev)
 {
+	set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
 	if (mddev->sync_thread) {
-		set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
 		set_bit(MD_RECOVERY_INTR, &mddev->recovery);
 		md_reap_sync_thread(mddev);
 	}
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 55951182af73..6e17f8181c4b 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -417,7 +417,17 @@ static void raid1_end_write_request(struct bio *bio, int error)
 
 		r1_bio->bios[mirror] = NULL;
 		to_put = bio;
-		set_bit(R1BIO_Uptodate, &r1_bio->state);
+		/*
+		 * Do not set R1BIO_Uptodate if the current device is
+		 * rebuilding or Faulty. This is because we cannot use
+		 * such device for properly reading the data back (we could
+		 * potentially use it, if the current write would have felt
+		 * before rdev->recovery_offset, but for simplicity we don't
+		 * check this here.
+		 */
+		if (test_bit(In_sync, &conf->mirrors[mirror].rdev->flags) &&
+		    !test_bit(Faulty, &conf->mirrors[mirror].rdev->flags))
+			set_bit(R1BIO_Uptodate, &r1_bio->state);
 
 		/* Maybe we can clear some bad blocks. */
 		if (is_badblock(conf->mirrors[mirror].rdev,
@@ -870,17 +880,17 @@ static void allow_barrier(struct r1conf *conf)
 	wake_up(&conf->wait_barrier);
 }
 
-static void freeze_array(struct r1conf *conf)
+static void freeze_array(struct r1conf *conf, int extra)
 {
 	/* stop syncio and normal IO and wait for everything to
 	 * go quite.
 	 * We increment barrier and nr_waiting, and then
-	 * wait until nr_pending match nr_queued+1
+	 * wait until nr_pending match nr_queued+extra
 	 * This is called in the context of one normal IO request
 	 * that has failed. Thus any sync request that might be pending
 	 * will be blocked by nr_pending, and we need to wait for
 	 * pending IO requests to complete or be queued for re-try.
-	 * Thus the number queued (nr_queued) plus this request (1)
+	 * Thus the number queued (nr_queued) plus this request (extra)
 	 * must match the number of pending IOs (nr_pending) before
 	 * we continue.
 	 */
@@ -888,7 +898,7 @@ static void freeze_array(struct r1conf *conf)
 	conf->barrier++;
 	conf->nr_waiting++;
 	wait_event_lock_irq_cmd(conf->wait_barrier,
-				conf->nr_pending == conf->nr_queued+1,
+				conf->nr_pending == conf->nr_queued+extra,
 				conf->resync_lock,
 				flush_pending_writes(conf));
 	spin_unlock_irq(&conf->resync_lock);
@@ -1544,8 +1554,8 @@ static int raid1_add_disk(struct mddev *mddev, struct md_rdev *rdev)
 		 * we wait for all outstanding requests to complete.
 		 */
 		synchronize_sched();
-		raise_barrier(conf);
-		lower_barrier(conf);
+		freeze_array(conf, 0);
+		unfreeze_array(conf);
 		clear_bit(Unmerged, &rdev->flags);
 	}
 	md_integrity_add_rdev(rdev, mddev);
@@ -1595,11 +1605,11 @@ static int raid1_remove_disk(struct mddev *mddev, struct md_rdev *rdev)
 			 */
 			struct md_rdev *repl =
 				conf->mirrors[conf->raid_disks + number].rdev;
-			raise_barrier(conf);
+			freeze_array(conf, 0);
 			clear_bit(Replacement, &repl->flags);
 			p->rdev = repl;
 			conf->mirrors[conf->raid_disks + number].rdev = NULL;
-			lower_barrier(conf);
+			unfreeze_array(conf);
 			clear_bit(WantReplacement, &rdev->flags);
 		} else
 			clear_bit(WantReplacement, &rdev->flags);
@@ -2195,7 +2205,7 @@ static void handle_read_error(struct r1conf *conf, struct r1bio *r1_bio)
 	 * frozen
 	 */
 	if (mddev->ro == 0) {
-		freeze_array(conf);
+		freeze_array(conf, 1);
 		fix_read_error(conf, r1_bio->read_disk,
 			       r1_bio->sector, r1_bio->sectors);
 		unfreeze_array(conf);
@@ -2780,8 +2790,8 @@ static int run(struct mddev *mddev)
 		return PTR_ERR(conf);
 
 	if (mddev->queue)
-		blk_queue_max_write_same_sectors(mddev->queue,
-						 mddev->chunk_sectors);
+		blk_queue_max_write_same_sectors(mddev->queue, 0);
+
 	rdev_for_each(rdev, mddev) {
 		if (!mddev->gendisk)
 			continue;
@@ -2963,7 +2973,7 @@ static int raid1_reshape(struct mddev *mddev)
 		return -ENOMEM;
 	}
 
-	raise_barrier(conf);
+	freeze_array(conf, 0);
 
 	/* ok, everything is stopped */
 	oldpool = conf->r1bio_pool;
@@ -2994,7 +3004,7 @@ static int raid1_reshape(struct mddev *mddev)
 	conf->raid_disks = mddev->raid_disks = raid_disks;
 	mddev->delta_disks = 0;
 
-	lower_barrier(conf);
+	unfreeze_array(conf);
 
 	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
 	md_wakeup_thread(mddev->thread);
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 59d4daa5f4c7..6ddae2501b9a 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -490,7 +490,17 @@ static void raid10_end_write_request(struct bio *bio, int error)
 		sector_t first_bad;
 		int bad_sectors;
 
-		set_bit(R10BIO_Uptodate, &r10_bio->state);
+		/*
+		 * Do not set R10BIO_Uptodate if the current device is
+		 * rebuilding or Faulty. This is because we cannot use
+		 * such device for properly reading the data back (we could
+		 * potentially use it, if the current write would have felt
+		 * before rdev->recovery_offset, but for simplicity we don't
+		 * check this here.
+		 */
+		if (test_bit(In_sync, &rdev->flags) &&
+		    !test_bit(Faulty, &rdev->flags))
+			set_bit(R10BIO_Uptodate, &r10_bio->state);
 
 		/* Maybe we can clear some bad blocks. */
 		if (is_badblock(rdev,
@@ -1055,17 +1065,17 @@ static void allow_barrier(struct r10conf *conf)
 	wake_up(&conf->wait_barrier);
 }
 
-static void freeze_array(struct r10conf *conf)
+static void freeze_array(struct r10conf *conf, int extra)
 {
 	/* stop syncio and normal IO and wait for everything to
 	 * go quiet.
 	 * We increment barrier and nr_waiting, and then
-	 * wait until nr_pending match nr_queued+1
+	 * wait until nr_pending match nr_queued+extra
 	 * This is called in the context of one normal IO request
 	 * that has failed. Thus any sync request that might be pending
 	 * will be blocked by nr_pending, and we need to wait for
 	 * pending IO requests to complete or be queued for re-try.
-	 * Thus the number queued (nr_queued) plus this request (1)
+	 * Thus the number queued (nr_queued) plus this request (extra)
 	 * must match the number of pending IOs (nr_pending) before
 	 * we continue.
 	 */
@@ -1073,7 +1083,7 @@ static void freeze_array(struct r10conf *conf)
 	conf->barrier++;
 	conf->nr_waiting++;
 	wait_event_lock_irq_cmd(conf->wait_barrier,
-				conf->nr_pending == conf->nr_queued+1,
+				conf->nr_pending == conf->nr_queued+extra,
 				conf->resync_lock,
 				flush_pending_writes(conf));
 
@@ -1837,8 +1847,8 @@ static int raid10_add_disk(struct mddev *mddev, struct md_rdev *rdev)
 		 * we wait for all outstanding requests to complete.
 		 */
 		synchronize_sched();
-		raise_barrier(conf, 0);
-		lower_barrier(conf);
+		freeze_array(conf, 0);
+		unfreeze_array(conf);
 		clear_bit(Unmerged, &rdev->flags);
 	}
 	md_integrity_add_rdev(rdev, mddev);
@@ -2612,7 +2622,7 @@ static void handle_read_error(struct mddev *mddev, struct r10bio *r10_bio)
 	r10_bio->devs[slot].bio = NULL;
 
 	if (mddev->ro == 0) {
-		freeze_array(conf);
+		freeze_array(conf, 1);
 		fix_read_error(conf, mddev, r10_bio);
 		unfreeze_array(conf);
 	} else
@@ -3609,8 +3619,7 @@ static int run(struct mddev *mddev)
 	if (mddev->queue) {
 		blk_queue_max_discard_sectors(mddev->queue,
 					      mddev->chunk_sectors);
-		blk_queue_max_write_same_sectors(mddev->queue,
-						 mddev->chunk_sectors);
+		blk_queue_max_write_same_sectors(mddev->queue, 0);
 		blk_queue_io_min(mddev->queue, chunk_size);
 		if (conf->geo.raid_disks % conf->geo.near_copies)
 			blk_queue_io_opt(mddev->queue, chunk_size * conf->geo.raid_disks);
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 9359828ffe26..05e4a105b9c7 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -664,6 +664,7 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
 			if (test_bit(R5_ReadNoMerge, &sh->dev[i].flags))
 				bi->bi_rw |= REQ_FLUSH;
 
+			bi->bi_vcnt = 1;
 			bi->bi_io_vec[0].bv_len = STRIPE_SIZE;
 			bi->bi_io_vec[0].bv_offset = 0;
 			bi->bi_size = STRIPE_SIZE;
@@ -701,6 +702,7 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
 			else
 				rbi->bi_sector = (sh->sector
 						  + rrdev->data_offset);
+			rbi->bi_vcnt = 1;
 			rbi->bi_io_vec[0].bv_len = STRIPE_SIZE;
 			rbi->bi_io_vec[0].bv_offset = 0;
 			rbi->bi_size = STRIPE_SIZE;
@@ -5464,7 +5466,7 @@ static int run(struct mddev *mddev)
 		if (mddev->major_version == 0 &&
 		    mddev->minor_version > 90)
 			rdev->recovery_offset = reshape_offset;
-			
+
 		if (rdev->recovery_offset < reshape_offset) {
 			/* We need to check old and new layout */
 			if (!only_parity(rdev->raid_disk,
@@ -5587,6 +5589,8 @@ static int run(struct mddev *mddev)
 		 */
 		mddev->queue->limits.discard_zeroes_data = 0;
 
+		blk_queue_max_write_same_sectors(mddev->queue, 0);
+
 		rdev_for_each(rdev, mddev) {
 			disk_stack_limits(mddev->gendisk, rdev->bdev,
 					  rdev->data_offset << 9);