btrfs: do not allow compression on nodatacow files

Compression and nodatacow are mutually exclusive. A similar issue was
fixed by commit f37c563bab429 ("btrfs: add missing check for nocow and
compression inode flags"). Besides ioctl, there is another way to
enable/disable/reset compression directly via xattr. The following
steps will result in a invalid combination.

  $ touch bar
  $ chattr +C bar
  $ lsattr bar
  ---------------C-- bar
  $ setfattr -n btrfs.compression -v zstd bar
  $ lsattr bar
  --------c------C-- bar

To align with the logic in check_fsflags, nocompress will also be
unacceptable after this patch, to prevent mix any compression-related
options with nodatacow.

  $ touch bar
  $ chattr +C bar
  $ lsattr bar
  ---------------C-- bar
  $ setfattr -n btrfs.compression -v zstd bar
  setfattr: bar: Invalid argument
  $ setfattr -n btrfs.compression -v no bar
  setfattr: bar: Invalid argument

When both compression and nodatacow are enabled, then
btrfs_run_delalloc_range prefers nodatacow and no compression happens.

Reported-by: Jayce Lin <jaycelin@synology.com>
CC: stable@vger.kernel.org # 5.10.x: e6f9d6964802: btrfs: export a helper for compression hard check
CC: stable@vger.kernel.org # 5.10.x
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chung-Chiang Cheng <cccheng@synology.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/fs/btrfs/xattr.c b/fs/btrfs/xattr.c
index 99abf41b89b9..9632d0ff2038 100644
--- a/fs/btrfs/xattr.c
+++ b/fs/btrfs/xattr.c
@@ -403,7 +403,7 @@ static int btrfs_xattr_handler_set_prop(const struct xattr_handler *handler,
 	struct btrfs_root *root = BTRFS_I(inode)->root;
 
 	name = xattr_full_name(handler, name);
-	ret = btrfs_validate_prop(name, value, size);
+	ret = btrfs_validate_prop(BTRFS_I(inode), name, value, size);
 	if (ret)
 		return ret;