xfs: catch a few more error codes when scrubbing secondary sb

The superblock validation routines return a variety of error codes to
reject a mount request.  For scrub we can assume that the mount
succeeded, so if we see these things appear when scrubbing secondary sb
X, we can treat them all like corruption.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

fs/xfs/scrub/agheader.c

@@ -126,6 +126,22 @@ xfs_scrub_superblock(
 	error = xfs_trans_read_buf(mp, sc->tp, mp->m_ddev_targp,
 		  XFS_AGB_TO_DADDR(mp, agno, XFS_SB_BLOCK(mp)),
 		  XFS_FSS_TO_BB(mp, 1), 0, &bp, &xfs_sb_buf_ops);
+	/*
+	 * The superblock verifier can return several different error codes
+	 * if it thinks the superblock doesn't look right.  For a mount these
+	 * would all get bounced back to userspace, but if we're here then the
+	 * fs mounted successfully, which means that this secondary superblock
+	 * is simply incorrect.  Treat all these codes the same way we treat
+	 * any corruption.
+	 */
+	switch (error) {
+	case -EINVAL:	/* also -EWRONGFS */
+	case -ENOSYS:
+	case -EFBIG:
+		error = -EFSCORRUPTED;
+	default:
+		break;
+	}
 	if (!xfs_scrub_process_error(sc, agno, XFS_SB_BLOCK(mp), &error))
 		return error;