[v15,07/42] btrfs: zoned: disallow fitrim on zoned filesystems

Commit Message

Naohiro Aota Feb. 4, 2021, 10:21 a.m. UTC

The implementation of fitrim depends on space cache, which is not used
and disabled for zoned extent allocator. So the current code does not
work with zoned filesystem.

In the future, we can implement fitrim for zoned filesystems by enabling
space cache (but, only for fitrim) or scanning the extent tree at fitrim
time.  For now, disallow fitrim on zoned filesystems.

Reviewed-by: Anand Jain <[e-mail]>
Reviewed-by: Josef Bacik <[e-mail]>
Signed-off-by: Naohiro Aota <[e-mail]>
Reviewed-by: David Sterba <[e-mail]>
---
 fs/btrfs/ioctl.c | 8 ++++++++
 1 file changed, 8 insertions(+)

Patch

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index e6a63f652235..a8c60d46d19c 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -527,6 +527,14 @@  static noinline int btrfs_ioctl_fitrim(struct btrfs_fs_info *fs_info,
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 
+	/*
+	 * btrfs_trim_block_group() depends on space cache, which is not
+	 * available in zoned filesystem. So, disallow fitrim on a zoned
+	 * filesystem for now.
+	 */
+	if (btrfs_is_zoned(fs_info))
+		return -EOPNOTSUPP;
+
 	/*
 	 * If the fs is mounted with nologreplay, which requires it to be
 	 * mounted in RO mode as well, we can not allow discard on free space