On 2020/9/3 15:46, Dave Chinner wrote:
On Thu, Sep 03, 2020 at 11:57:13AM +0800, Xiao Yang wrote:
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@xxxxxxxxxxxxxx>
Reviewed-by: Darrick J. Wong<darrick.wong@xxxxxxxxxx>
---
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;
I don't think we can do this as it may break existing applications
that have been working on XFS for many, many years that don't
correctly initialise fsx_xflags....
Hi Dave,
It seems that the only way is to keep the current behavior. :-(
By the way, _require_xfs_io_command "chattr" in xfstests cannot check XFS's
unsupported xflags directly because of the behavior, so we may need to check
them by extra xfs_io -c "lsattr".
Best Regards,
Xiao Yang
Cheers,
Dave.
