Re: [PATCH v2 16/23] xfs: add inode on-disk VERITY flag

[Dave Chinner via Linux-erofs <linux-erofs@lists.ozlabs.org>]

On Tue, Apr 04, 2023 at 03:41:23PM -0700, Eric Biggers wrote:
> Hi Andrey,
> 
> On Tue, Apr 04, 2023 at 04:53:12PM +0200, Andrey Albershteyn wrote:
> > Add flag to mark inodes which have fs-verity enabled on them (i.e.
> > descriptor exist and tree is built).
> > 
> > Signed-off-by: Andrey Albershteyn <aalbersh@redhat.com>
> > ---
> >  fs/ioctl.c                 | 4 ++++
> >  fs/xfs/libxfs/xfs_format.h | 4 +++-
> >  fs/xfs/xfs_inode.c         | 2 ++
> >  fs/xfs/xfs_iops.c          | 2 ++
> >  include/uapi/linux/fs.h    | 1 +
> >  5 files changed, 12 insertions(+), 1 deletion(-)
> [...]
> > diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h
> > index b7b56871029c..5172a2eb902c 100644
> > --- a/include/uapi/linux/fs.h
> > +++ b/include/uapi/linux/fs.h
> > @@ -140,6 +140,7 @@ struct fsxattr {
> >  #define FS_XFLAG_FILESTREAM	0x00004000	/* use filestream allocator */
> >  #define FS_XFLAG_DAX		0x00008000	/* use DAX for IO */
> >  #define FS_XFLAG_COWEXTSIZE	0x00010000	/* CoW extent size allocator hint */
> > +#define FS_XFLAG_VERITY		0x00020000	/* fs-verity sealed inode */
> >  #define FS_XFLAG_HASATTR	0x80000000	/* no DIFLAG for this	*/
> >  
> 
> I don't think "xfs: add inode on-disk VERITY flag" is an accurate description of
> a patch that involves adding something to the UAPI.

Well it does that, but it also adds the UAPI for querying the
on-disk flag via the FS_IOC_FSGETXATTR interface as well.  It
probably should be split up into two patches.

> Should the other filesystems support this new flag too?

I think they should get it automatically now that it has been
defined for FS_IOC_FSGETXATTR and added to the generic fileattr flag
fill functions in fs/ioctl.c.

> I'd also like all ways of getting the verity flag to continue to be mentioned in
> Documentation/filesystems/fsverity.rst.  The existing methods (FS_IOC_GETFLAGS
> and statx) are already mentioned there.

*nod*

-Dave.
-- 
Dave Chinner
david@fromorbit.com