xfs: don't catch dax+reflink inodes as corruption in verifier

We don't yet support dax on reflinked files, but that is in the works.

Further, having the flag set does not automatically mean that the inode
is actually "in the CPU direct access state," which depends on several
other conditions in addition to the flag being set.

As such, we should not catch this as corruption in the verifier - simply
not actually enabling S_DAX on reflinked files is enough for now.

Fixes: 4f435ebe ("xfs: don't mix reflink and DAX mode for now")
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
[darrick: fix the scrubber too]
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

fs/xfs/libxfs/xfs_inode_buf.c

@@ -547,10 +547,6 @@ xfs_dinode_verify(
 	if ((flags2 & XFS_DIFLAG2_REFLINK) && (flags & XFS_DIFLAG_REALTIME))
 		return __this_address;
 
-	/* don't let reflink and dax mix */
-	if ((flags2 & XFS_DIFLAG2_REFLINK) && (flags2 & XFS_DIFLAG2_DAX))
-		return __this_address;
-
 	/* COW extent size hint validation */
 	fa = xfs_inode_validate_cowextsize(mp, be32_to_cpu(dip->di_cowextsize),
 			mode, flags, flags2);

fs/xfs/scrub/inode.c

@@ -185,10 +185,6 @@ xchk_inode_flags2(
 	if ((flags & XFS_DIFLAG_REALTIME) && (flags2 & XFS_DIFLAG2_REFLINK))
 		goto bad;
 
-	/* dax and reflink make no sense, currently */
-	if ((flags2 & XFS_DIFLAG2_DAX) && (flags2 & XFS_DIFLAG2_REFLINK))
-		goto bad;
-
 	/* no bigtime iflag without the bigtime feature */
 	if (xfs_dinode_has_bigtime(dip) &&
 	    !xfs_sb_version_hasbigtime(&mp->m_sb))