Btrfs: fix wrong size for the reservation of the, snapshot creation

We should insert/update 6 items(root ref, root backref, dir item, dir index,
root item and parent inode) when creating a snapshot, not 5 items, fix it.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 36e03312267..b6b33e463ac 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -4414,10 +4414,10 @@ int btrfs_snap_reserve_metadata(struct btrfs_trans_handle *trans,
         struct btrfs_block_rsv *src_rsv = get_block_rsv(trans, root);
         struct btrfs_block_rsv *dst_rsv = &pending->block_rsv;
         /*
-         * two for root back/forward refs, two for directory entries
-         * and one for root of the snapshot.
+         * two for root back/forward refs, two for directory entries,
+         * one for root of the snapshot and one for parent inode.
          */
-        u64 num_bytes = btrfs_calc_trans_metadata_size(root, 5);
+        u64 num_bytes = btrfs_calc_trans_metadata_size(root, 6);
         dst_rsv->space_info = src_rsv->space_info;
         return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);
 }