Re: [RFC 2/3] xfs_io: Add ext4 support to show FS_IOC_FSGETXATTR details

[Dave Chinner]

On Wed, Dec 11, 2024 at 10:17:06AM -0800, Darrick J. Wong wrote:
> On Wed, Dec 11, 2024 at 01:24:03PM +0530, Ojaswin Mujoo wrote:
> > Currently with stat we only show FS_IOC_FSGETXATTR details
> > if the filesystem is XFS. With extsize support also coming
> > to ext4 make sure to show these details when -c "stat" or "statx"
> > is used.
> > 
> > No functional changes for filesystems other than ext4.
> > 
> > Signed-off-by: Ojaswin Mujoo <ojaswin@xxxxxxxxxxxxx>
> > ---
> >  io/stat.c | 38 +++++++++++++++++++++-----------------
> >  1 file changed, 21 insertions(+), 17 deletions(-)
> > 
> > diff --git a/io/stat.c b/io/stat.c
> > index 326f2822e276..d06c2186cde4 100644
> > --- a/io/stat.c
> > +++ b/io/stat.c
> > @@ -97,14 +97,14 @@ print_file_info(void)
> >  		file->flags & IO_TMPFILE ? _(",tmpfile") : "");
> >  }
> >  
> > -static void
> > -print_xfs_info(int verbose)
> > +static void print_extended_info(int verbose)
> >  {
> > -	struct dioattr	dio;
> > -	struct fsxattr	fsx, fsxa;
> > +	struct dioattr dio;
> > +	struct fsxattr fsx, fsxa;
> > +	bool is_xfs_fd = platform_test_xfs_fd(file->fd);
> >  
> > -	if ((xfsctl(file->name, file->fd, FS_IOC_FSGETXATTR, &fsx)) < 0 ||
> > -	    (xfsctl(file->name, file->fd, XFS_IOC_FSGETXATTRA, &fsxa)) < 0) {
> > +	if ((ioctl(file->fd, FS_IOC_FSGETXATTR, &fsx)) < 0 ||
> > +		(is_xfs_fd && (xfsctl(file->name, file->fd, XFS_IOC_FSGETXATTRA, &fsxa) < 0))) {
> 
> Urgh... perhaps we should call FS_IOC_FSGETXATTR and if it returns zero
> print whatever is returned, no matter what filesystem we think is
> feeding us information?

Yes, please. FS_IOC_FSGETXATTR has been generic functionality for
some time, we should treat it the same way for all filesystems.

> e.g.
> 
> 	if (ioctl(file->fd, FS_IOC_FSGETXATTR, &fsx)) < 0) {
> 		if (is_xfs_fd || (errno != EOPNOTSUPP &&
> 				  errno != ENOTTY))
> 			perror("FS_IOC_GETXATTR");

Why do we even need "is_xfs_fd" there? XFS will never give a
EOPNOTSUPP or ENOTTY error to this or the FS_IOC_GETXATTRA ioctl...

-Dave.
-- 
Dave Chinner
david@xxxxxxxxxxxxx