xfs: verify AGI unlinked list contains valid blocks

The heads of tha AGI unlinked list are only scanned on debug
kernels when the verifier runs. Change that to always scan the heads
and validate that the inode numbers are valid.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

fs/xfs/libxfs/xfs_ialloc.c

@@ -2477,26 +2477,13 @@ xfs_ialloc_log_agi(
 	}
 }
 
-#ifdef DEBUG
-STATIC void
-xfs_check_agi_unlinked(
-	struct xfs_agi		*agi)
-{
-	int			i;
-
-	for (i = 0; i < XFS_AGI_UNLINKED_BUCKETS; i++)
-		ASSERT(agi->agi_unlinked[i]);
-}
-#else
-#define xfs_check_agi_unlinked(agi)
-#endif
-
 static xfs_failaddr_t
 xfs_agi_verify(
 	struct xfs_buf	*bp)
 {
 	struct xfs_mount *mp = bp->b_target->bt_mount;
 	struct xfs_agi	*agi = XFS_BUF_TO_AGI(bp);
+	int		i;
 
 	if (xfs_sb_version_hascrc(&mp->m_sb)) {
 		if (!uuid_equal(&agi->agi_uuid, &mp->m_sb.sb_meta_uuid))
@@ -2532,7 +2519,13 @@ xfs_agi_verify(
 	if (bp->b_pag && be32_to_cpu(agi->agi_seqno) != bp->b_pag->pag_agno)
 		return __this_address;
 
-	xfs_check_agi_unlinked(agi);
+	for (i = 0; i < XFS_AGI_UNLINKED_BUCKETS; i++) {
+		if (agi->agi_unlinked[i] == NULLAGINO)
+			continue;
+		if (!xfs_verify_ino(mp, be32_to_cpu(agi->agi_unlinked[i])))
+			return __this_address;
+	}
+
 	return NULL;
 }