1 files changed, 149 insertions, 120 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index f556c3732c2c..2d4667594681 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -319,9 +319,9 @@ static int csum_tree_block(struct btrfs_fs_info *fs_info,
 			memcpy(&found, result, csum_size);
 
 			read_extent_buffer(buf, &val, 0, csum_size);
-			printk_ratelimited(KERN_WARNING
-				"BTRFS: %s checksum verify failed on %llu wanted %X found %X "
-				"level %d\n",
+			btrfs_warn_rl(fs_info,
+				"%s checksum verify failed on %llu wanted %X found %X "
+				"level %d",
 				fs_info->sb->s_id, buf->start,
 				val, found, btrfs_header_level(buf));
 			if (result != (char *)&inline_result)
@@ -368,9 +368,9 @@ static int verify_parent_transid(struct extent_io_tree *io_tree,
 		ret = 0;
 		goto out;
 	}
-	printk_ratelimited(KERN_ERR
-	    "BTRFS (device %s): parent transid verify failed on %llu wanted %llu found %llu\n",
-			eb->fs_info->sb->s_id, eb->start,
+	btrfs_err_rl(eb->fs_info,
+		"parent transid verify failed on %llu wanted %llu found %llu",
+			eb->start,
 			parent_transid, btrfs_header_generation(eb));
 	ret = 1;
 
@@ -629,15 +629,14 @@ static int btree_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
 
 	found_start = btrfs_header_bytenr(eb);
 	if (found_start != eb->start) {
-		printk_ratelimited(KERN_ERR "BTRFS (device %s): bad tree block start "
-			       "%llu %llu\n",
-			       eb->fs_info->sb->s_id, found_start, eb->start);
+		btrfs_err_rl(eb->fs_info, "bad tree block start %llu %llu",
+			       found_start, eb->start);
 		ret = -EIO;
 		goto err;
 	}
 	if (check_tree_block_fsid(root->fs_info, eb)) {
-		printk_ratelimited(KERN_ERR "BTRFS (device %s): bad fsid on block %llu\n",
-			       eb->fs_info->sb->s_id, eb->start);
+		btrfs_err_rl(eb->fs_info, "bad fsid on block %llu",
+			       eb->start);
 		ret = -EIO;
 		goto err;
 	}
@@ -703,7 +702,7 @@ static int btree_io_failed_hook(struct page *page, int failed_mirror)
 	return -EIO;	/* we fixed nothing */
 }
 
-static void end_workqueue_bio(struct bio *bio, int err)
+static void end_workqueue_bio(struct bio *bio)
 {
 	struct btrfs_end_io_wq *end_io_wq = bio->bi_private;
 	struct btrfs_fs_info *fs_info;
@@ -711,7 +710,7 @@ static void end_workqueue_bio(struct bio *bio, int err)
 	btrfs_work_func_t func;
 
 	fs_info = end_io_wq->info;
-	end_io_wq->error = err;
+	end_io_wq->error = bio->bi_error;
 
 	if (bio->bi_rw & REQ_WRITE) {
 		if (end_io_wq->metadata == BTRFS_WQ_ENDIO_METADATA) {
@@ -802,13 +801,17 @@ static void run_one_async_done(struct btrfs_work *work)
 	limit = btrfs_async_submit_limit(fs_info);
 	limit = limit * 2 / 3;
 
+	/*
+	 * atomic_dec_return implies a barrier for waitqueue_active
+	 */
 	if (atomic_dec_return(&fs_info->nr_async_submits) < limit &&
 	    waitqueue_active(&fs_info->async_submit_wait))
 		wake_up(&fs_info->async_submit_wait);
 
 	/* If an error occured we just want to clean up the bio and move on */
 	if (async->error) {
-		bio_endio(async->bio, async->error);
+		async->bio->bi_error = async->error;
+		bio_endio(async->bio);
 		return;
 	}
 
@@ -908,8 +911,10 @@ static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
 	 * submission context.  Just jump into btrfs_map_bio
 	 */
 	ret = btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
-	if (ret)
-		bio_endio(bio, ret);
+	if (ret) {
+		bio->bi_error = ret;
+		bio_endio(bio);
+	}
 	return ret;
 }
 
@@ -960,10 +965,13 @@ static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
 					  __btree_submit_bio_done);
 	}
 
-	if (ret) {
+	if (ret)
+		goto out_w_error;
+	return 0;
+
 out_w_error:
-		bio_endio(bio, ret);
-	}
+	bio->bi_error = ret;
+	bio_endio(bio);
 	return ret;
 }
 
@@ -1259,6 +1267,7 @@ static void __setup_root(u32 nodesize, u32 sectorsize, u32 stripesize,
 	atomic_set(&root->orphan_inodes, 0);
 	atomic_set(&root->refs, 1);
 	atomic_set(&root->will_be_snapshoted, 0);
+	atomic_set(&root->qgroup_meta_rsv, 0);
 	root->log_transid = 0;
 	root->log_transid_committed = -1;
 	root->last_log_commit = 0;
@@ -1724,6 +1733,7 @@ static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
 	bdi->ra_pages = VM_MAX_READAHEAD * 1024 / PAGE_CACHE_SIZE;
 	bdi->congested_fn	= btrfs_congested_fn;
 	bdi->congested_data	= info;
+	bdi->capabilities |= BDI_CAP_CGROUP_WRITEBACK;
 	return 0;
 }
 
@@ -1735,16 +1745,15 @@ static void end_workqueue_fn(struct btrfs_work *work)
 {
 	struct bio *bio;
 	struct btrfs_end_io_wq *end_io_wq;
-	int error;
 
 	end_io_wq = container_of(work, struct btrfs_end_io_wq, work);
 	bio = end_io_wq->bio;
 
-	error = end_io_wq->error;
+	bio->bi_error = end_io_wq->error;
 	bio->bi_private = end_io_wq->private;
 	bio->bi_end_io = end_io_wq->end_io;
 	kmem_cache_free(btrfs_end_io_wq_cache, end_io_wq);
-	bio_endio(bio, error);
+	bio_endio(bio);
 }
 
 static int cleaner_kthread(void *arg)
@@ -1753,6 +1762,7 @@ static int cleaner_kthread(void *arg)
 	int again;
 	struct btrfs_trans_handle *trans;
 
+	set_freezable();
 	do {
 		again = 0;
 
@@ -2342,8 +2352,7 @@ static int btrfs_replay_log(struct btrfs_fs_info *fs_info,
 	u64 bytenr = btrfs_super_log_root(disk_super);
 
 	if (fs_devices->rw_devices == 0) {
-		printk(KERN_WARNING "BTRFS: log replay required "
-		       "on RO media\n");
+		btrfs_warn(fs_info, "log replay required on RO media");
 		return -EIO;
 	}
 
@@ -2358,12 +2367,12 @@ static int btrfs_replay_log(struct btrfs_fs_info *fs_info,
 	log_tree_root->node = read_tree_block(tree_root, bytenr,
 			fs_info->generation + 1);
 	if (IS_ERR(log_tree_root->node)) {
-		printk(KERN_ERR "BTRFS: failed to read log tree\n");
+		btrfs_warn(fs_info, "failed to read log tree");
 		ret = PTR_ERR(log_tree_root->node);
 		kfree(log_tree_root);
 		return ret;
 	} else if (!extent_buffer_uptodate(log_tree_root->node)) {
-		printk(KERN_ERR "BTRFS: failed to read log tree\n");
+		btrfs_err(fs_info, "failed to read log tree");
 		free_extent_buffer(log_tree_root->node);
 		kfree(log_tree_root);
 		return -EIO;
@@ -2371,7 +2380,7 @@ static int btrfs_replay_log(struct btrfs_fs_info *fs_info,
 	/* returns with log_tree_root freed on success */
 	ret = btrfs_recover_log_trees(log_tree_root);
 	if (ret) {
-		btrfs_error(tree_root->fs_info, ret,
+		btrfs_std_error(tree_root->fs_info, ret,
 			    "Failed to recover log tree");
 		free_extent_buffer(log_tree_root->node);
 		kfree(log_tree_root);
@@ -2608,7 +2617,6 @@ int open_ctree(struct super_block *sb,
 
 
 	mutex_init(&fs_info->ordered_operations_mutex);
-	mutex_init(&fs_info->ordered_extent_flush_mutex);
 	mutex_init(&fs_info->tree_log_mutex);
 	mutex_init(&fs_info->chunk_mutex);
 	mutex_init(&fs_info->transaction_kthread_mutex);
@@ -2648,8 +2656,8 @@ int open_ctree(struct super_block *sb,
 	 * Read super block and check the signature bytes only
 	 */
 	bh = btrfs_read_dev_super(fs_devices->latest_bdev);
-	if (!bh) {
-		err = -EINVAL;
+	if (IS_ERR(bh)) {
+		err = PTR_ERR(bh);
 		goto fail_alloc;
 	}
 
@@ -2842,6 +2850,8 @@ int open_ctree(struct super_block *sb,
 	    !extent_buffer_uptodate(chunk_root->node)) {
 		printk(KERN_ERR "BTRFS: failed to read chunk root on %s\n",
 		       sb->s_id);
+		if (!IS_ERR(chunk_root->node))
+			free_extent_buffer(chunk_root->node);
 		chunk_root->node = NULL;
 		goto fail_tree_roots;
 	}
@@ -2880,6 +2890,8 @@ retry_root_backup:
 	    !extent_buffer_uptodate(tree_root->node)) {
 		printk(KERN_WARNING "BTRFS: failed to read tree root on %s\n",
 		       sb->s_id);
+		if (!IS_ERR(tree_root->node))
+			free_extent_buffer(tree_root->node);
 		tree_root->node = NULL;
 		goto recovery_tree_root;
 	}
@@ -2928,7 +2940,7 @@ retry_root_backup:
 		goto fail_fsdev_sysfs;
 	}
 
-	ret = btrfs_sysfs_add_one(fs_info);
+	ret = btrfs_sysfs_add_mounted(fs_info);
 	if (ret) {
 		pr_err("BTRFS: failed to init sysfs interface: %d\n", ret);
 		goto fail_fsdev_sysfs;
@@ -2950,8 +2962,9 @@ retry_root_backup:
 	if (fs_info->fs_devices->missing_devices >
 	     fs_info->num_tolerated_disk_barrier_failures &&
 	    !(sb->s_flags & MS_RDONLY)) {
-		printk(KERN_WARNING "BTRFS: "
-			"too many missing devices, writeable mount is not allowed\n");
+		pr_warn("BTRFS: missing devices(%llu) exceeds the limit(%d), writeable mount is not allowed\n",
+			fs_info->fs_devices->missing_devices,
+			fs_info->num_tolerated_disk_barrier_failures);
 		goto fail_sysfs;
 	}
 
@@ -3107,7 +3120,7 @@ fail_cleaner:
 	filemap_write_and_wait(fs_info->btree_inode->i_mapping);
 
 fail_sysfs:
-	btrfs_sysfs_remove_one(fs_info);
+	btrfs_sysfs_remove_mounted(fs_info);
 
 fail_fsdev_sysfs:
 	btrfs_sysfs_remove_fsid(fs_info->fs_devices);
@@ -3169,8 +3182,8 @@ static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
 		struct btrfs_device *device = (struct btrfs_device *)
 			bh->b_private;
 
-		printk_ratelimited_in_rcu(KERN_WARNING "BTRFS: lost page write due to "
-					  "I/O error on %s\n",
+		btrfs_warn_rl_in_rcu(device->dev_root->fs_info,
+				"lost page write due to IO error on %s",
 					  rcu_str_deref(device->name));
 		/* note, we dont' set_buffer_write_io_error because we have
 		 * our own ways of dealing with the IO errors
@@ -3182,6 +3195,37 @@ static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
 	put_bh(bh);
 }
 
+int btrfs_read_dev_one_super(struct block_device *bdev, int copy_num,
+			struct buffer_head **bh_ret)
+{
+	struct buffer_head *bh;
+	struct btrfs_super_block *super;
+	u64 bytenr;
+
+	bytenr = btrfs_sb_offset(copy_num);
+	if (bytenr + BTRFS_SUPER_INFO_SIZE >= i_size_read(bdev->bd_inode))
+		return -EINVAL;
+
+	bh = __bread(bdev, bytenr / 4096, BTRFS_SUPER_INFO_SIZE);
+	/*
+	 * If we fail to read from the underlying devices, as of now
+	 * the best option we have is to mark it EIO.
+	 */
+	if (!bh)
+		return -EIO;
+
+	super = (struct btrfs_super_block *)bh->b_data;
+	if (btrfs_super_bytenr(super) != bytenr ||
+		    btrfs_super_magic(super) != BTRFS_MAGIC) {
+		brelse(bh);
+		return -EINVAL;
+	}
+
+	*bh_ret = bh;
+	return 0;
+}
+
+
 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
 {
 	struct buffer_head *bh;
@@ -3189,7 +3233,7 @@ struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
 	struct btrfs_super_block *super;
 	int i;
 	u64 transid = 0;
-	u64 bytenr;
+	int ret = -EINVAL;
 
 	/* we would like to check all the supers, but that would make
 	 * a btrfs mount succeed after a mkfs from a different FS.
@@ -3197,21 +3241,11 @@ struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
 	 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
 	 */
 	for (i = 0; i < 1; i++) {
-		bytenr = btrfs_sb_offset(i);
-		if (bytenr + BTRFS_SUPER_INFO_SIZE >=
-					i_size_read(bdev->bd_inode))
-			break;
-		bh = __bread(bdev, bytenr / 4096,
-					BTRFS_SUPER_INFO_SIZE);
-		if (!bh)
+		ret = btrfs_read_dev_one_super(bdev, i, &bh);
+		if (ret)
 			continue;
 
 		super = (struct btrfs_super_block *)bh->b_data;
-		if (btrfs_super_bytenr(super) != bytenr ||
-		    btrfs_super_magic(super) != BTRFS_MAGIC) {
-			brelse(bh);
-			continue;
-		}
 
 		if (!latest || btrfs_super_generation(super) > transid) {
 			brelse(latest);
@@ -3221,6 +3255,10 @@ struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
 			brelse(bh);
 		}
 	}
+
+	if (!latest)
+		return ERR_PTR(ret);
+
 	return latest;
 }
 
@@ -3289,8 +3327,9 @@ static int write_dev_supers(struct btrfs_device *device,
 			bh = __getblk(device->bdev, bytenr / 4096,
 				      BTRFS_SUPER_INFO_SIZE);
 			if (!bh) {
-				printk(KERN_ERR "BTRFS: couldn't get super "
-				       "buffer head for bytenr %Lu\n", bytenr);
+				btrfs_err(device->dev_root->fs_info,
+				    "couldn't get super buffer head for bytenr %llu",
+				    bytenr);
 				errors++;
 				continue;
 			}
@@ -3324,10 +3363,8 @@ static int write_dev_supers(struct btrfs_device *device,
  * endio for the write_dev_flush, this will wake anyone waiting
  * for the barrier when it is done
  */
-static void btrfs_end_empty_barrier(struct bio *bio, int err)
+static void btrfs_end_empty_barrier(struct bio *bio)
 {
-	if (err)
-		clear_bit(BIO_UPTODATE, &bio->bi_flags);
 	if (bio->bi_private)
 		complete(bio->bi_private);
 	bio_put(bio);
@@ -3355,8 +3392,8 @@ static int write_dev_flush(struct btrfs_device *device, int wait)
 
 		wait_for_completion(&device->flush_wait);
 
-		if (!bio_flagged(bio, BIO_UPTODATE)) {
-			ret = -EIO;
+		if (bio->bi_error) {
+			ret = bio->bi_error;
 			btrfs_dev_stat_inc_and_print(device,
 				BTRFS_DEV_STAT_FLUSH_ERRS);
 		}
@@ -3439,6 +3476,35 @@ static int barrier_all_devices(struct btrfs_fs_info *info)
 	return 0;
 }
 
+int btrfs_get_num_tolerated_disk_barrier_failures(u64 flags)
+{
+	int raid_type;
+	int min_tolerated = INT_MAX;
+
+	if ((flags & BTRFS_BLOCK_GROUP_PROFILE_MASK) == 0 ||
+	    (flags & BTRFS_AVAIL_ALLOC_BIT_SINGLE))
+		min_tolerated = min(min_tolerated,
+				    btrfs_raid_array[BTRFS_RAID_SINGLE].
+				    tolerated_failures);
+
+	for (raid_type = 0; raid_type < BTRFS_NR_RAID_TYPES; raid_type++) {
+		if (raid_type == BTRFS_RAID_SINGLE)
+			continue;
+		if (!(flags & btrfs_raid_group[raid_type]))
+			continue;
+		min_tolerated = min(min_tolerated,
+				    btrfs_raid_array[raid_type].
+				    tolerated_failures);
+	}
+
+	if (min_tolerated == INT_MAX) {
+		pr_warn("BTRFS: unknown raid flag: %llu\n", flags);
+		min_tolerated = 0;
+	}
+
+	return min_tolerated;
+}
+
 int btrfs_calc_num_tolerated_disk_barrier_failures(
 	struct btrfs_fs_info *fs_info)
 {
@@ -3448,13 +3514,12 @@ int btrfs_calc_num_tolerated_disk_barrier_failures(
 		       BTRFS_BLOCK_GROUP_SYSTEM,
 		       BTRFS_BLOCK_GROUP_METADATA,
 		       BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA};
-	int num_types = 4;
 	int i;
 	int c;
 	int num_tolerated_disk_barrier_failures =
 		(int)fs_info->fs_devices->num_devices;
 
-	for (i = 0; i < num_types; i++) {
+	for (i = 0; i < ARRAY_SIZE(types); i++) {
 		struct btrfs_space_info *tmp;
 
 		sinfo = NULL;
@@ -3472,44 +3537,21 @@ int btrfs_calc_num_tolerated_disk_barrier_failures(
 
 		down_read(&sinfo->groups_sem);
 		for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
-			if (!list_empty(&sinfo->block_groups[c])) {
-				u64 flags;
-
-				btrfs_get_block_group_info(
-					&sinfo->block_groups[c], &space);
-				if (space.total_bytes == 0 ||
-				    space.used_bytes == 0)
-					continue;
-				flags = space.flags;
-				/*
-				 * return
-				 * 0: if dup, single or RAID0 is configured for
-				 *    any of metadata, system or data, else
-				 * 1: if RAID5 is configured, or if RAID1 or
-				 *    RAID10 is configured and only two mirrors
-				 *    are used, else
-				 * 2: if RAID6 is configured, else
-				 * num_mirrors - 1: if RAID1 or RAID10 is
-				 *                  configured and more than
-				 *                  2 mirrors are used.
-				 */
-				if (num_tolerated_disk_barrier_failures > 0 &&
-				    ((flags & (BTRFS_BLOCK_GROUP_DUP |
-					       BTRFS_BLOCK_GROUP_RAID0)) ||
-				     ((flags & BTRFS_BLOCK_GROUP_PROFILE_MASK)
-				      == 0)))
-					num_tolerated_disk_barrier_failures = 0;
-				else if (num_tolerated_disk_barrier_failures > 1) {
-					if (flags & (BTRFS_BLOCK_GROUP_RAID1 |
-					    BTRFS_BLOCK_GROUP_RAID5 |
-					    BTRFS_BLOCK_GROUP_RAID10)) {
-						num_tolerated_disk_barrier_failures = 1;
-					} else if (flags &
-						   BTRFS_BLOCK_GROUP_RAID6) {
-						num_tolerated_disk_barrier_failures = 2;
-					}
-				}
-			}
+			u64 flags;
+
+			if (list_empty(&sinfo->block_groups[c]))
+				continue;
+
+			btrfs_get_block_group_info(&sinfo->block_groups[c],
+						   &space);
+			if (space.total_bytes == 0 || space.used_bytes == 0)
+				continue;
+			flags = space.flags;
+
+			num_tolerated_disk_barrier_failures = min(
+				num_tolerated_disk_barrier_failures,
+				btrfs_get_num_tolerated_disk_barrier_failures(
+					flags));
 		}
 		up_read(&sinfo->groups_sem);
 	}
@@ -3544,7 +3586,7 @@ static int write_all_supers(struct btrfs_root *root, int max_mirrors)
 		if (ret) {
 			mutex_unlock(
 				&root->fs_info->fs_devices->device_list_mutex);
-			btrfs_error(root->fs_info, ret,
+			btrfs_std_error(root->fs_info, ret,
 				    "errors while submitting device barriers.");
 			return ret;
 		}
@@ -3584,7 +3626,7 @@ static int write_all_supers(struct btrfs_root *root, int max_mirrors)
 		mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
 
 		/* FUA is masked off if unsupported and can't be the reason */
-		btrfs_error(root->fs_info, -EIO,
+		btrfs_std_error(root->fs_info, -EIO,
 			    "%d errors while writing supers", total_errors);
 		return -EIO;
 	}
@@ -3602,7 +3644,7 @@ static int write_all_supers(struct btrfs_root *root, int max_mirrors)
 	}
 	mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
 	if (total_errors > max_errors) {
-		btrfs_error(root->fs_info, -EIO,
+		btrfs_std_error(root->fs_info, -EIO,
 			    "%d errors while writing supers", total_errors);
 		return -EIO;
 	}
@@ -3760,6 +3802,13 @@ void close_ctree(struct btrfs_root *root)
 	cancel_work_sync(&fs_info->async_reclaim_work);
 
 	if (!(fs_info->sb->s_flags & MS_RDONLY)) {
+		/*
+		 * If the cleaner thread is stopped and there are
+		 * block groups queued for removal, the deletion will be
+		 * skipped when we quit the cleaner thread.
+		 */
+		btrfs_delete_unused_bgs(root->fs_info);
+
 		ret = btrfs_commit_super(root);
 		if (ret)
 			btrfs_err(fs_info, "commit super ret %d", ret);
@@ -3781,7 +3830,7 @@ void close_ctree(struct btrfs_root *root)
 		       percpu_counter_sum(&fs_info->delalloc_bytes));
 	}
 
-	btrfs_sysfs_remove_one(fs_info);
+	btrfs_sysfs_remove_mounted(fs_info);
 	btrfs_sysfs_remove_fsid(fs_info->fs_devices);
 
 	btrfs_free_fs_roots(fs_info);
@@ -4279,25 +4328,6 @@ again:
 	return 0;
 }
 
-static void btrfs_free_pending_ordered(struct btrfs_transaction *cur_trans,
-				       struct btrfs_fs_info *fs_info)
-{
-	struct btrfs_ordered_extent *ordered;
-
-	spin_lock(&fs_info->trans_lock);
-	while (!list_empty(&cur_trans->pending_ordered)) {
-		ordered = list_first_entry(&cur_trans->pending_ordered,
-					   struct btrfs_ordered_extent,
-					   trans_list);
-		list_del_init(&ordered->trans_list);
-		spin_unlock(&fs_info->trans_lock);
-
-		btrfs_put_ordered_extent(ordered);
-		spin_lock(&fs_info->trans_lock);
-	}
-	spin_unlock(&fs_info->trans_lock);
-}
-
 void btrfs_cleanup_one_transaction(struct btrfs_transaction *cur_trans,
 				   struct btrfs_root *root)
 {
@@ -4309,7 +4339,6 @@ void btrfs_cleanup_one_transaction(struct btrfs_transaction *cur_trans,
 	cur_trans->state = TRANS_STATE_UNBLOCKED;
 	wake_up(&root->fs_info->transaction_wait);
 
-	btrfs_free_pending_ordered(cur_trans, root->fs_info);
 	btrfs_destroy_delayed_inodes(root);
 	btrfs_assert_delayed_root_empty(root);