btrfs: free correct amount of space in btrfs_delayed_inode_reserve_me…

…tadata

commit 0f9c03d upstream.

Following commit f218ea6 ("btrfs: delayed-inode: Remove wrong
qgroup meta reservation calls") this function now reserves num_bytes,
rather than the fixed amount of nodesize. As such this requires the
same amount to be freed in case of failure. Fix this by adjusting
the amount we are freeing.

Fixes: f218ea6 ("btrfs: delayed-inode: Remove wrong qgroup meta reservation calls")
CC: stable@vger.kernel.org # 4.19+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fs/btrfs/delayed-inode.c

@@ -649,7 +649,7 @@ static int btrfs_delayed_inode_reserve_metadata(
 						      btrfs_ino(inode),
 						      num_bytes, 1);
 		} else {
-			btrfs_qgroup_free_meta_prealloc(root, fs_info->nodesize);
+			btrfs_qgroup_free_meta_prealloc(root, num_bytes);
 		}
 		return ret;
 	}