xfs: block map scrub should handle incore delalloc reservations

Enhance the block map scrubber to check delayed allocation reservations.
Though there are no physical space allocations to check, we do need to
make sure that the range of file offsets being mapped are correct, and
to bump the lastoff cursor so that key order checking works correctly.
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>
Reviewed-by: NDave Chinner <dchinner@redhat.com>

fs/xfs/scrub/bmap.c

@@ -368,14 +368,13 @@ xchk_bmap_dirattr_extent(
 }
 
 /* Scrub a single extent record. */
-STATIC int
+STATIC void
 xchk_bmap_iextent(
 	struct xfs_inode	*ip,
 	struct xchk_bmap_info	*info,
 	struct xfs_bmbt_irec	*irec)
 {
 	struct xfs_mount	*mp = info->sc->mp;
-	int			error = 0;
 
 	/*
 	 * Check for out-of-order extents.  This record could have come
@@ -396,14 +395,6 @@ xchk_bmap_iextent(
 		xchk_fblock_set_corrupt(info->sc, info->whichfork,
 				irec->br_startoff);
 
-	/*
-	 * Check for delalloc extents.  We never iterate the ones in the
-	 * in-core extent scan, and we should never see these in the bmbt.
-	 */
-	if (isnullstartblock(irec->br_startblock))
-		xchk_fblock_set_corrupt(info->sc, info->whichfork,
-				irec->br_startoff);
-
 	/* Make sure the extent points to a valid place. */
 	if (irec->br_blockcount > XFS_MAX_BMBT_EXTLEN)
 		xchk_fblock_set_corrupt(info->sc, info->whichfork,
@@ -424,15 +415,12 @@ xchk_bmap_iextent(
 				irec->br_startoff);
 
 	if (info->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
-		return 0;
+		return;
 
 	if (info->is_rt)
 		xchk_bmap_rt_iextent_xref(ip, info, irec);
 	else
 		xchk_bmap_iextent_xref(ip, info, irec);
-
-	info->lastoff = irec->br_startoff + irec->br_blockcount;
-	return error;
 }
 
 /* Scrub a bmbt record. */
@@ -680,6 +668,33 @@ xchk_bmap_check_rmaps(
 	return 0;
 }
 
+/* Scrub a delalloc reservation from the incore extent map tree. */
+STATIC void
+xchk_bmap_iextent_delalloc(
+	struct xfs_inode	*ip,
+	struct xchk_bmap_info	*info,
+	struct xfs_bmbt_irec	*irec)
+{
+	struct xfs_mount	*mp = info->sc->mp;
+
+	/*
+	 * Check for out-of-order extents.  This record could have come
+	 * from the incore list, for which there is no ordering check.
+	 */
+	if (irec->br_startoff < info->lastoff)
+		xchk_fblock_set_corrupt(info->sc, info->whichfork,
+				irec->br_startoff);
+
+	if (!xfs_verify_fileext(mp, irec->br_startoff, irec->br_blockcount))
+		xchk_fblock_set_corrupt(info->sc, info->whichfork,
+				irec->br_startoff);
+
+	/* Make sure the extent points to a valid place. */
+	if (irec->br_blockcount > XFS_MAX_BMBT_EXTLEN)
+		xchk_fblock_set_corrupt(info->sc, info->whichfork,
+				irec->br_startoff);
+}
+
 /*
  * Scrub an inode fork's block mappings.
  *
@@ -764,16 +779,18 @@ xchk_bmap(
 		if (xchk_should_terminate(sc, &error) ||
 		    (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT))
 			goto out;
-		if (isnullstartblock(irec.br_startblock))
-			continue;
+
 		if (irec.br_startoff >= endoff) {
 			xchk_fblock_set_corrupt(sc, whichfork,
 					irec.br_startoff);
 			goto out;
 		}
-		error = xchk_bmap_iextent(ip, &info, &irec);
-		if (error)
-			goto out;
+
+		if (isnullstartblock(irec.br_startblock))
+			xchk_bmap_iextent_delalloc(ip, &info, &irec);
+		else
+			xchk_bmap_iextent(ip, &info, &irec);
+		info.lastoff = irec.br_startoff + irec.br_blockcount;
 	}
 
 	error = xchk_bmap_check_rmaps(sc, whichfork);