[PATCH v3] xfs: Add check for unsupported xflags

Xiao Yang
2020-09-03T03:57:29Z

Current ioctl(FSSETXATTR) ignores unsupported xflags silently
so it is not clear for user to know unsupported xflags.
For example, use ioctl(FSSETXATTR) to set dax flag on kernel
v4.4 which doesn't support dax flag:
--------------------------------
# xfs_io -f -c "chattr +x" testfile;echo $?
0
# xfs_io -c "lsattr" testfile
----------------X testfile
--------------------------------

Add check to return -EOPNOTSUPP as ext4/f2fs/btrfs does.

Signed-off-by: Xiao Yang <yangx.jy@cn.fujitsu.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
---
fs/xfs/xfs_ioctl.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index 6f22a66777cd..59f9a86f29f7 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -1425,6 +1425,14 @@ xfs_ioctl_setattr_check_projid(
return 0;
}

+#define XFS_SUPPORTED_FS_XFLAGS \
+ (FS_XFLAG_REALTIME | FS_XFLAG_PREALLOC | FS_XFLAG_IMMUTABLE | \
+ FS_XFLAG_APPEND | FS_XFLAG_SYNC | FS_XFLAG_NOATIME | FS_XFLAG_NODUMP | \
+ FS_XFLAG_RTINHERIT | FS_XFLAG_PROJINHERIT | FS_XFLAG_NOSYMLINKS | \
+ FS_XFLAG_EXTSIZE | FS_XFLAG_EXTSZINHERIT | FS_XFLAG_NODEFRAG | \
+ FS_XFLAG_FILESTREAM | FS_XFLAG_DAX | FS_XFLAG_COWEXTSIZE | \
+ FS_XFLAG_HASATTR)
+
STATIC int
xfs_ioctl_setattr(
xfs_inode_t *ip,
@@ -1439,6 +1447,10 @@ xfs_ioctl_setattr(

trace_xfs_ioctl_setattr(ip);

+ /* Check if fsx_xflags has unsupported xflags */
+ if (fa->fsx_xflags & ~XFS_SUPPORTED_FS_XFLAGS)
+ return -EOPNOTSUPP;
+
code = xfs_ioctl_setattr_check_projid(ip, fa);
if (code)
return code;
--
2.25.1