Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block

* 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block: (65 commits)
  Documentation/iostats.txt: bit-size reference etc.
  cfq-iosched: removing unnecessary think time checking
  cfq-iosched: Don't clear queue stats when preempt.
  blk-throttle: Reset group slice when limits are changed
  blk-cgroup: Only give unaccounted_time under debug
  cfq-iosched: Don't set active queue in preempt
  block: fix non-atomic access to genhd inflight structures
  block: attempt to merge with existing requests on plug flush
  block: NULL dereference on error path in __blkdev_get()
  cfq-iosched: Don't update group weights when on service tree
  fs: assign sb->s_bdi to default_backing_dev_info if the bdi is going away
  block: Require subsystems to explicitly allocate bio_set integrity mempool
  jbd2: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging
  jbd: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging
  fs: make fsync_buffers_list() plug
  mm: make generic_writepages() use plugging
  blk-cgroup: Add unaccounted time to timeslice_used.
  block: fixup plugging stubs for !CONFIG_BLOCK
  block: remove obsolete comments for blkdev_issue_zeroout.
  blktrace: Use rq->cmd_flags directly in blk_add_trace_rq.
  ...

Fix up conflicts in fs/{aio.c,super.c}

64 files changed, 116 insertions, 445 deletions

diff --git a/fs/adfs/inode.c b/fs/adfs/inode.c
index 92444e94f842..d5250c5aae21 100644
--- a/fs/adfs/inode.c
+++ b/fs/adfs/inode.c
@@ -72,7 +72,6 @@ static sector_t _adfs_bmap(struct address_space *mapping, sector_t block)
 static const struct address_space_operations adfs_aops = {
 	.readpage	= adfs_readpage,
 	.writepage	= adfs_writepage,
-	.sync_page	= block_sync_page,
 	.write_begin	= adfs_write_begin,
 	.write_end	= generic_write_end,
 	.bmap		= _adfs_bmap
diff --git a/fs/affs/file.c b/fs/affs/file.c
index 0a90dcd46de2..acf321b70fcd 100644
--- a/fs/affs/file.c
+++ b/fs/affs/file.c
@@ -429,7 +429,6 @@ static sector_t _affs_bmap(struct address_space *mapping, sector_t block)
 const struct address_space_operations affs_aops = {
 	.readpage = affs_readpage,
 	.writepage = affs_writepage,
-	.sync_page = block_sync_page,
 	.write_begin = affs_write_begin,
 	.write_end = generic_write_end,
 	.bmap = _affs_bmap
@@ -786,7 +785,6 @@ out:
 const struct address_space_operations affs_aops_ofs = {
 	.readpage = affs_readpage_ofs,
 	//.writepage = affs_writepage_ofs,
-	//.sync_page = affs_sync_page_ofs,
 	.write_begin = affs_write_begin_ofs,
 	.write_end = affs_write_end_ofs
 };
diff --git a/fs/aio.c b/fs/aio.c
index ebb6a22e4e1b..e29ec485af25 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -34,8 +34,6 @@
 #include <linux/security.h>
 #include <linux/eventfd.h>
 #include <linux/blkdev.h>
-#include <linux/mempool.h>
-#include <linux/hash.h>
 #include <linux/compat.h>
 
 #include <asm/kmap_types.h>
@@ -65,14 +63,6 @@ static DECLARE_WORK(fput_work, aio_fput_routine);
 static DEFINE_SPINLOCK(fput_lock);
 static LIST_HEAD(fput_head);
 
-#define AIO_BATCH_HASH_BITS	3 /* allocated on-stack, so don't go crazy */
-#define AIO_BATCH_HASH_SIZE	(1 << AIO_BATCH_HASH_BITS)
-struct aio_batch_entry {
-	struct hlist_node list;
-	struct address_space *mapping;
-};
-mempool_t *abe_pool;
-
 static void aio_kick_handler(struct work_struct *);
 static void aio_queue_work(struct kioctx *);
 
@@ -86,8 +76,7 @@ static int __init aio_setup(void)
 	kioctx_cachep = KMEM_CACHE(kioctx,SLAB_HWCACHE_ALIGN|SLAB_PANIC);
 
 	aio_wq = alloc_workqueue("aio", 0, 1);	/* used to limit concurrency */
-	abe_pool = mempool_create_kmalloc_pool(1, sizeof(struct aio_batch_entry));
-	BUG_ON(!aio_wq || !abe_pool);
+	BUG_ON(!aio_wq);
 
 	pr_debug("aio_setup: sizeof(struct page) = %d\n", (int)sizeof(struct page));
 
@@ -1525,57 +1514,8 @@ static ssize_t aio_setup_iocb(struct kiocb *kiocb, bool compat)
 	return 0;
 }
 
-static void aio_batch_add(struct address_space *mapping,
-			  struct hlist_head *batch_hash)
-{
-	struct aio_batch_entry *abe;
-	struct hlist_node *pos;
-	unsigned bucket;
-
-	bucket = hash_ptr(mapping, AIO_BATCH_HASH_BITS);
-	hlist_for_each_entry(abe, pos, &batch_hash[bucket], list) {
-		if (abe->mapping == mapping)
-			return;
-	}
-
-	abe = mempool_alloc(abe_pool, GFP_KERNEL);
-
-	/*
-	 * we should be using igrab here, but
-	 * we don't want to hammer on the global
-	 * inode spinlock just to take an extra
-	 * reference on a file that we must already
-	 * have a reference to.
-	 *
-	 * When we're called, we always have a reference
-	 * on the file, so we must always have a reference
-	 * on the inode, so ihold() is safe here.
-	 */
-	ihold(mapping->host);
-	abe->mapping = mapping;
-	hlist_add_head(&abe->list, &batch_hash[bucket]);
-	return;
-}
-
-static void aio_batch_free(struct hlist_head *batch_hash)
-{
-	struct aio_batch_entry *abe;
-	struct hlist_node *pos, *n;
-	int i;
-
-	for (i = 0; i < AIO_BATCH_HASH_SIZE; i++) {
-		hlist_for_each_entry_safe(abe, pos, n, &batch_hash[i], list) {
-			blk_run_address_space(abe->mapping);
-			iput(abe->mapping->host);
-			hlist_del(&abe->list);
-			mempool_free(abe, abe_pool);
-		}
-	}
-}
-
 static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
-			 struct iocb *iocb, struct hlist_head *batch_hash,
-			 bool compat)
+			 struct iocb *iocb, bool compat)
 {
 	struct kiocb *req;
 	struct file *file;
@@ -1666,11 +1606,6 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
 			;
 	}
 	spin_unlock_irq(&ctx->ctx_lock);
-	if (req->ki_opcode == IOCB_CMD_PREAD ||
-	    req->ki_opcode == IOCB_CMD_PREADV ||
-	    req->ki_opcode == IOCB_CMD_PWRITE ||
-	    req->ki_opcode == IOCB_CMD_PWRITEV)
-		aio_batch_add(file->f_mapping, batch_hash);
 
 	aio_put_req(req);	/* drop extra ref to req */
 	return 0;
@@ -1687,7 +1622,7 @@ long do_io_submit(aio_context_t ctx_id, long nr,
 	struct kioctx *ctx;
 	long ret = 0;
 	int i;
-	struct hlist_head batch_hash[AIO_BATCH_HASH_SIZE] = { { 0, }, };
+	struct blk_plug plug;
 
 	if (unlikely(nr < 0))
 		return -EINVAL;
@@ -1704,6 +1639,8 @@ long do_io_submit(aio_context_t ctx_id, long nr,
 		return -EINVAL;
 	}
 
+	blk_start_plug(&plug);
+
 	/*
 	 * AKPM: should this return a partial result if some of the IOs were
 	 * successfully submitted?
@@ -1722,11 +1659,11 @@ long do_io_submit(aio_context_t ctx_id, long nr,
 			break;
 		}
 
-		ret = io_submit_one(ctx, user_iocb, &tmp, batch_hash, compat);
+		ret = io_submit_one(ctx, user_iocb, &tmp, compat);
 		if (ret)
 			break;
 	}
-	aio_batch_free(batch_hash);
+	blk_finish_plug(&plug);
 
 	put_ioctx(ctx);
 	return i ? i : ret;
diff --git a/fs/befs/linuxvfs.c b/fs/befs/linuxvfs.c
index b1d0c794747b..06457ed8f3e7 100644
--- a/fs/befs/linuxvfs.c
+++ b/fs/befs/linuxvfs.c
@@ -75,7 +75,6 @@ static const struct inode_operations befs_dir_inode_operations = {
 
 static const struct address_space_operations befs_aops = {
 	.readpage	= befs_readpage,
-	.sync_page	= block_sync_page,
 	.bmap		= befs_bmap,
 };
 
diff --git a/fs/bfs/file.c b/fs/bfs/file.c
index eb67edd0f8ea..f20e8a71062f 100644
--- a/fs/bfs/file.c
+++ b/fs/bfs/file.c
@@ -186,7 +186,6 @@ static sector_t bfs_bmap(struct address_space *mapping, sector_t block)
 const struct address_space_operations bfs_aops = {
 	.readpage	= bfs_readpage,
 	.writepage	= bfs_writepage,
-	.sync_page	= block_sync_page,
 	.write_begin	= bfs_write_begin,
 	.write_end	= generic_write_end,
 	.bmap		= bfs_bmap,
diff --git a/fs/bio-integrity.c b/fs/bio-integrity.c
index e49cce234c65..9c5e6b2cd11a 100644
--- a/fs/bio-integrity.c
+++ b/fs/bio-integrity.c
@@ -761,6 +761,9 @@ int bioset_integrity_create(struct bio_set *bs, int pool_size)
 {
 	unsigned int max_slab = vecs_to_idx(BIO_MAX_PAGES);
 
+	if (bs->bio_integrity_pool)
+		return 0;
+
 	bs->bio_integrity_pool =
 		mempool_create_slab_pool(pool_size, bip_slab[max_slab].slab);
 
diff --git a/fs/bio.c b/fs/bio.c
index 4cf2a52fbc54..4d6d4b6c2bf1 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -43,7 +43,7 @@ static mempool_t *bio_split_pool __read_mostly;
  * unsigned short
  */
 #define BV(x) { .nr_vecs = x, .name = "biovec-"__stringify(x) }
-struct biovec_slab bvec_slabs[BIOVEC_NR_POOLS] __read_mostly = {
+static struct biovec_slab bvec_slabs[BIOVEC_NR_POOLS] __read_mostly = {
 	BV(1), BV(4), BV(16), BV(64), BV(128), BV(BIO_MAX_PAGES),
 };
 #undef BV
@@ -1636,9 +1636,6 @@ struct bio_set *bioset_create(unsigned int pool_size, unsigned int front_pad)
 	if (!bs->bio_pool)
 		goto bad;
 
-	if (bioset_integrity_create(bs, pool_size))
-		goto bad;
-
 	if (!biovec_create_pools(bs, pool_size))
 		return bs;
 
@@ -1656,12 +1653,10 @@ static void __init biovec_init_slabs(void)
 		int size;
 		struct biovec_slab *bvs = bvec_slabs + i;
 
-#ifndef CONFIG_BLK_DEV_INTEGRITY
 		if (bvs->nr_vecs <= BIO_INLINE_VECS) {
 			bvs->slab = NULL;
 			continue;
 		}
-#endif
 
 		size = bvs->nr_vecs * sizeof(struct bio_vec);
 		bvs->slab = kmem_cache_create(bvs->name, size, 0,
@@ -1684,6 +1679,9 @@ static int __init init_bio(void)
 	if (!fs_bio_set)
 		panic("bio: can't allocate bios\n");
 
+	if (bioset_integrity_create(fs_bio_set, BIO_POOL_SIZE))
+		panic("bio: can't create integrity pool\n");
+
 	bio_split_pool = mempool_create_kmalloc_pool(BIO_SPLIT_ENTRIES,
 						     sizeof(struct bio_pair));
 	if (!bio_split_pool)
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 889287019599..7d02afb2b7f4 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1087,6 +1087,7 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
 	if (!disk)
 		goto out;
 
+	disk_block_events(disk);
 	mutex_lock_nested(&bdev->bd_mutex, for_part);
 	if (!bdev->bd_openers) {
 		bdev->bd_disk = disk;
@@ -1108,10 +1109,11 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
 					 */
 					disk_put_part(bdev->bd_part);
 					bdev->bd_part = NULL;
-					module_put(disk->fops->owner);
-					put_disk(disk);
 					bdev->bd_disk = NULL;
 					mutex_unlock(&bdev->bd_mutex);
+					disk_unblock_events(disk);
+					module_put(disk->fops->owner);
+					put_disk(disk);
 					goto restart;
 				}
 				if (ret)
@@ -1148,9 +1150,6 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
 			bd_set_size(bdev, (loff_t)bdev->bd_part->nr_sects << 9);
 		}
 	} else {
-		module_put(disk->fops->owner);
-		put_disk(disk);
-		disk = NULL;
 		if (bdev->bd_contains == bdev) {
 			if (bdev->bd_disk->fops->open) {
 				ret = bdev->bd_disk->fops->open(bdev, mode);
@@ -1160,11 +1159,15 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
 			if (bdev->bd_invalidated)
 				rescan_partitions(bdev->bd_disk, bdev);
 		}
+		/* only one opener holds refs to the module and disk */
+		module_put(disk->fops->owner);
+		put_disk(disk);
 	}
 	bdev->bd_openers++;
 	if (for_part)
 		bdev->bd_part_count++;
 	mutex_unlock(&bdev->bd_mutex);
+	disk_unblock_events(disk);
 	return 0;
 
  out_clear:
@@ -1177,10 +1180,10 @@ static int __blkdev_get(struct block_device *bdev, fmode_t mode, int for_part)
 	bdev->bd_contains = NULL;
  out_unlock_bdev:
 	mutex_unlock(&bdev->bd_mutex);
- out:
-	if (disk)
-		module_put(disk->fops->owner);
+	disk_unblock_events(disk);
+	module_put(disk->fops->owner);
 	put_disk(disk);
+ out:
 	bdput(bdev);
 
 	return ret;
@@ -1446,14 +1449,13 @@ int blkdev_put(struct block_device *bdev, fmode_t mode)
 		if (bdev_free) {
 			if (bdev->bd_write_holder) {
 				disk_unblock_events(bdev->bd_disk);
-				bdev->bd_write_holder = false;
-			} else
 				disk_check_events(bdev->bd_disk);
+				bdev->bd_write_holder = false;
+			}
 		}
 
 		mutex_unlock(&bdev->bd_mutex);
-	} else
-		disk_check_events(bdev->bd_disk);
+	}
 
 	return __blkdev_put(bdev, mode, 0);
 }
@@ -1527,7 +1529,6 @@ static int blkdev_releasepage(struct page *page, gfp_t wait)
 static const struct address_space_operations def_blk_aops = {
 	.readpage	= blkdev_readpage,
 	.writepage	= blkdev_writepage,
-	.sync_page	= block_sync_page,
 	.write_begin	= blkdev_write_begin,
 	.write_end	= blkdev_write_end,
 	.writepages	= generic_writepages,
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 100b07f021b4..830d261d0e6b 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -847,7 +847,6 @@ static const struct address_space_operations btree_aops = {
 	.writepages	= btree_writepages,
 	.releasepage	= btree_releasepage,
 	.invalidatepage = btree_invalidatepage,
-	.sync_page	= block_sync_page,
 #ifdef CONFIG_MIGRATION
 	.migratepage	= btree_migratepage,
 #endif
@@ -1331,82 +1330,6 @@ static int btrfs_congested_fn(void *congested_data, int bdi_bits)
 }
 
 /*
- * this unplugs every device on the box, and it is only used when page
- * is null
- */
-static void __unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
-{
-	struct btrfs_device *device;
-	struct btrfs_fs_info *info;
-
-	info = (struct btrfs_fs_info *)bdi->unplug_io_data;
-	list_for_each_entry(device, &info->fs_devices->devices, dev_list) {
-		if (!device->bdev)
-			continue;
-
-		bdi = blk_get_backing_dev_info(device->bdev);
-		if (bdi->unplug_io_fn)
-			bdi->unplug_io_fn(bdi, page);
-	}
-}
-
-static void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
-{
-	struct inode *inode;
-	struct extent_map_tree *em_tree;
-	struct extent_map *em;
-	struct address_space *mapping;
-	u64 offset;
-
-	/* the generic O_DIRECT read code does this */
-	if (1 || !page) {
-		__unplug_io_fn(bdi, page);
-		return;
-	}
-
-	/*
-	 * page->mapping may change at any time.  Get a consistent copy
-	 * and use that for everything below
-	 */
-	smp_mb();
-	mapping = page->mapping;
-	if (!mapping)
-		return;
-
-	inode = mapping->host;
-
-	/*
-	 * don't do the expensive searching for a small number of
-	 * devices
-	 */
-	if (BTRFS_I(inode)->root->fs_info->fs_devices->open_devices <= 2) {
-		__unplug_io_fn(bdi, page);
-		return;
-	}
-
-	offset = page_offset(page);
-
-	em_tree = &BTRFS_I(inode)->extent_tree;
-	read_lock(&em_tree->lock);
-	em = lookup_extent_mapping(em_tree, offset, PAGE_CACHE_SIZE);
-	read_unlock(&em_tree->lock);
-	if (!em) {
-		__unplug_io_fn(bdi, page);
-		return;
-	}
-
-	if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
-		free_extent_map(em);
-		__unplug_io_fn(bdi, page);
-		return;
-	}
-	offset = offset - em->start;
-	btrfs_unplug_page(&BTRFS_I(inode)->root->fs_info->mapping_tree,
-			  em->block_start + offset, page);
-	free_extent_map(em);
-}
-
-/*
  * If this fails, caller must call bdi_destroy() to get rid of the
  * bdi again.
  */
@@ -1420,8 +1343,6 @@ static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
 		return err;
 
 	bdi->ra_pages	= default_backing_dev_info.ra_pages;
-	bdi->unplug_io_fn	= btrfs_unplug_io_fn;
-	bdi->unplug_io_data	= info;
 	bdi->congested_fn	= btrfs_congested_fn;
 	bdi->congested_data	= info;
 	return 0;
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 714adc4ac4c2..b5b92824a271 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2188,7 +2188,7 @@ static int __extent_writepage(struct page *page, struct writeback_control *wbc,
 	unsigned long nr_written = 0;
 
 	if (wbc->sync_mode == WB_SYNC_ALL)
-		write_flags = WRITE_SYNC_PLUG;
+		write_flags = WRITE_SYNC;
 	else
 		write_flags = WRITE;
 
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 512c3d1da083..119520bdb9a5 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -7340,7 +7340,6 @@ static const struct address_space_operations btrfs_aops = {
 	.writepage	= btrfs_writepage,
 	.writepages	= btrfs_writepages,
 	.readpages	= btrfs_readpages,
-	.sync_page	= block_sync_page,
 	.direct_IO	= btrfs_direct_IO,
 	.invalidatepage = btrfs_invalidatepage,
 	.releasepage	= btrfs_releasepage,
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index dd13eb81ee40..9d554e8e6583 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -162,7 +162,6 @@ static noinline int run_scheduled_bios(struct btrfs_device *device)
 	struct bio *cur;
 	int again = 0;
 	unsigned long num_run;
-	unsigned long num_sync_run;
 	unsigned long batch_run = 0;
 	unsigned long limit;
 	unsigned long last_waited = 0;
@@ -173,11 +172,6 @@ static noinline int run_scheduled_bios(struct btrfs_device *device)
 	limit = btrfs_async_submit_limit(fs_info);
 	limit = limit * 2 / 3;
 
-	/* we want to make sure that every time we switch from the sync
-	 * list to the normal list, we unplug
-	 */
-	num_sync_run = 0;
-
 loop:
 	spin_lock(&device->io_lock);
 
@@ -223,15 +217,6 @@ loop_lock:
 
 	spin_unlock(&device->io_lock);
 
-	/*
-	 * if we're doing the regular priority list, make sure we unplug
-	 * for any high prio bios we've sent down
-	 */
-	if (pending_bios == &device->pending_bios && num_sync_run > 0) {
-		num_sync_run = 0;
-		blk_run_backing_dev(bdi, NULL);
-	}
-
 	while (pending) {
 
 		rmb();
@@ -259,19 +244,11 @@ loop_lock:
 
 		BUG_ON(atomic_read(&cur->bi_cnt) == 0);
 
-		if (cur->bi_rw & REQ_SYNC)
-			num_sync_run++;
-
 		submit_bio(cur->bi_rw, cur);
 		num_run++;
 		batch_run++;
-		if (need_resched()) {
-			if (num_sync_run) {
-				blk_run_backing_dev(bdi, NULL);
-				num_sync_run = 0;
-			}
+		if (need_resched())
 			cond_resched();
-		}
 
 		/*
 		 * we made progress, there is more work to do and the bdi
@@ -304,13 +281,8 @@ loop_lock:
 				 * against it before looping
 				 */
 				last_waited = ioc->last_waited;
-				if (need_resched()) {
-					if (num_sync_run) {
-						blk_run_backing_dev(bdi, NULL);
-						num_sync_run = 0;
-					}
+				if (need_resched())
 					cond_resched();
-				}
 				continue;
 			}
 			spin_lock(&device->io_lock);
@@ -323,22 +295,6 @@ loop_lock:
 		}
 	}
 
-	if (num_sync_run) {
-		num_sync_run = 0;
-		blk_run_backing_dev(bdi, NULL);
-	}
-	/*
-	 * IO has already been through a long path to get here.  Checksumming,
-	 * async helper threads, perhaps compression.  We've done a pretty
-	 * good job of collecting a batch of IO and should just unplug
-	 * the device right away.
-	 *
-	 * This will help anyone who is waiting on the IO, they might have
-	 * already unplugged, but managed to do so before the bio they
-	 * cared about found its way down here.
-	 */
-	blk_run_backing_dev(bdi, NULL);
-
 	cond_resched();
 	if (again)
 		goto loop;
@@ -2955,7 +2911,7 @@ static int find_live_mirror(struct map_lookup *map, int first, int num,
 static int __btrfs_map_block(struct btrfs_mapping_tree *map_tree, int rw,
 			     u64 logical, u64 *length,
 			     struct btrfs_multi_bio **multi_ret,
-			     int mirror_num, struct page *unplug_page)
+			     int mirror_num)
 {
 	struct extent_map *em;
 	struct map_lookup *map;
@@ -2987,11 +2943,6 @@ again:
 	em = lookup_extent_mapping(em_tree, logical, *length);
 	read_unlock(&em_tree->lock);
 
-	if (!em && unplug_page) {
-		kfree(multi);
-		return 0;
-	}
-
 	if (!em) {
 		printk(KERN_CRIT "unable to find logical %llu len %llu\n",
 		       (unsigned long long)logical,
@@ -3047,13 +2998,13 @@ again:
 		*length = em->len - offset;
 	}
 
-	if (!multi_ret && !unplug_page)
+	if (!multi_ret)
 		goto out;
 
 	num_stripes = 1;
 	stripe_index = 0;
 	if (map->type & BTRFS_BLOCK_GROUP_RAID1) {
-		if (unplug_page || (rw & REQ_WRITE))
+		if (rw & REQ_WRITE)
 			num_stripes = map->num_stripes;
 		else if (mirror_num)