Re: [PATCH] xfs: remove unused xfs_ioctl32.h declarations

["Darrick J. Wong" <djwong@kernel.org>]

On Tue, Jan 18, 2022 at 12:50:12PM -0600, Eric Sandeen wrote:
> On 1/18/22 12:30 PM, Darrick J. Wong wrote:
> > From: Darrick J. Wong <djwong@kernel.org>
> > 
> > Remove these unused ia32 compat declarations; all the bits involved have
> > either been withdrawn or hoisted to the VFS.
> 
> Hm, don't we still have all the non-compat counterparts still live in
> fs/xfs/libxfs/xfs_fs.h, or am I not keeping up?
> 
> #define XFS_IOC_RESVSP		_IOW ('X', 40, struct xfs_flock64)
> #define XFS_IOC_UNRESVSP	_IOW ('X', 41, struct xfs_flock64)
> #define XFS_IOC_RESVSP64	_IOW ('X', 42, struct xfs_flock64)
> #define XFS_IOC_UNRESVSP64	_IOW ('X', 43, struct xfs_flock64)
> #define XFS_IOC_ZERO_RANGE	_IOW ('X', 57, struct xfs_flock64)
> 
> Why remove the compat ones but leave the abo ve? Aren't these all valid and
> tested ioctls, just under a different #define, and therefore harmless and
> also useful for backwards compatibility?
> 
> I feel like I'm missing something. :)

The implementation of those five ioctls (including all the ioctl32
compat noise) were hoisted to the VFS by Al and Christoph back in 2019.
Hence the #defines in xfs_ioctl32.h are no longer referenced by any
kernel code.  However, they missed the opportunity to remove these
definitions.

The struct compat_xfs_flock64 was still in use by the allocsp/freesp
xfs_ioctl32 code, but now that we're erasing it from history, it can go.

The definitions in xfs_fs.h have to be kept around because we export
them to userspace via /usr/include/xfs/xfs_fs.h.

--D

> > Signed-off-by: Darrick J. Wong <djwong@kernel.org>
> > ---
> >   fs/xfs/xfs_ioctl32.h |   18 ------------------
> >   1 file changed, 18 deletions(-)
> > 
> > diff --git a/fs/xfs/xfs_ioctl32.h b/fs/xfs/xfs_ioctl32.h
> > index fc5a91f3a5e0..c14852362fce 100644
> > --- a/fs/xfs/xfs_ioctl32.h
> > +++ b/fs/xfs/xfs_ioctl32.h
> > @@ -142,24 +142,6 @@ typedef struct compat_xfs_fsop_attrmulti_handlereq {
> >   	_IOW('X', 123, struct compat_xfs_fsop_attrmulti_handlereq)
> >   #ifdef BROKEN_X86_ALIGNMENT
> > -/* on ia32 l_start is on a 32-bit boundary */
> > -typedef struct compat_xfs_flock64 {
> > -	__s16		l_type;
> > -	__s16		l_whence;
> > -	__s64		l_start	__attribute__((packed));
> > -			/* len == 0 means until end of file */
> > -	__s64		l_len __attribute__((packed));
> > -	__s32		l_sysid;
> > -	__u32		l_pid;
> > -	__s32		l_pad[4];	/* reserve area */
> > -} compat_xfs_flock64_t;
> > -
> > -#define XFS_IOC_RESVSP_32	_IOW('X', 40, struct compat_xfs_flock64)
> > -#define XFS_IOC_UNRESVSP_32	_IOW('X', 41, struct compat_xfs_flock64)
> > -#define XFS_IOC_RESVSP64_32	_IOW('X', 42, struct compat_xfs_flock64)
> > -#define XFS_IOC_UNRESVSP64_32	_IOW('X', 43, struct compat_xfs_flock64)
> > -#define XFS_IOC_ZERO_RANGE_32	_IOW('X', 57, struct compat_xfs_flock64)
> > -
> >   typedef struct compat_xfs_fsop_geom_v1 {
> >   	__u32		blocksize;	/* filesystem (data) block size */
> >   	__u32		rtextsize;	/* realtime extent size		*/
> >