Btrfs: Fix per root used space accounting

The bytes_used field in root item was originally planned to
trace the amount of used data and tree blocks. But it never
worked right since we can't trace freeing of data accurately.
This patch changes it to only trace the amount of tree blocks.

Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 3d6b33871afe..645a17927a8f 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -289,7 +289,7 @@ static noinline int create_subvol(struct btrfs_root *root,
         btrfs_set_root_generation(&root_item, trans->transid);
         btrfs_set_root_level(&root_item, 0);
         btrfs_set_root_refs(&root_item, 1);
-        btrfs_set_root_used(&root_item, 0);
+        btrfs_set_root_used(&root_item, leaf->len);
         btrfs_set_root_last_snapshot(&root_item, 0);
 
         memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));