xfs: cross-reference the block mappings when possible

Use an inode's block mappings to cross-reference inode block counters.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

fs/xfs/scrub/inode.c

@@ -37,6 +37,8 @@
 #include "xfs_da_format.h"
 #include "xfs_reflink.h"
 #include "xfs_rmap.h"
+#include "xfs_bmap.h"
+#include "xfs_bmap_util.h"
 #include "scrub/xfs_scrub.h"
 #include "scrub/scrub.h"
 #include "scrub/common.h"
@@ -626,6 +628,37 @@ xfs_scrub_inode_xref_finobt(
 		xfs_scrub_btree_xref_set_corrupt(sc, sc->sa.fino_cur, 0);
 }
 
+/* Cross reference the inode fields with the forks. */
+STATIC void
+xfs_scrub_inode_xref_bmap(
+	struct xfs_scrub_context	*sc,
+	struct xfs_dinode		*dip)
+{
+	xfs_extnum_t			nextents;
+	xfs_filblks_t			count;
+	xfs_filblks_t			acount;
+	int				error;
+
+	/* Walk all the extents to check nextents/naextents/nblocks. */
+	error = xfs_bmap_count_blocks(sc->tp, sc->ip, XFS_DATA_FORK,
+			&nextents, &count);
+	if (!xfs_scrub_should_check_xref(sc, &error, NULL))
+		return;
+	if (nextents < be32_to_cpu(dip->di_nextents))
+		xfs_scrub_ino_xref_set_corrupt(sc, sc->ip->i_ino, NULL);
+
+	error = xfs_bmap_count_blocks(sc->tp, sc->ip, XFS_ATTR_FORK,
+			&nextents, &acount);
+	if (!xfs_scrub_should_check_xref(sc, &error, NULL))
+		return;
+	if (nextents != be16_to_cpu(dip->di_anextents))
+		xfs_scrub_ino_xref_set_corrupt(sc, sc->ip->i_ino, NULL);
+
+	/* Check nblocks against the inode. */
+	if (count + acount != be64_to_cpu(dip->di_nblocks))
+		xfs_scrub_ino_xref_set_corrupt(sc, sc->ip->i_ino, NULL);
+}
+
 /* Cross-reference with the other btrees. */
 STATIC void
 xfs_scrub_inode_xref(
@@ -653,6 +686,7 @@ xfs_scrub_inode_xref(
 	xfs_rmap_ag_owner(&oinfo, XFS_RMAP_OWN_INODES);
 	xfs_scrub_xref_is_owned_by(sc, agbno, 1, &oinfo);
 	xfs_scrub_xref_is_not_shared(sc, agbno, 1);
+	xfs_scrub_inode_xref_bmap(sc, dip);
 
 	xfs_scrub_ag_free(sc, &sc->sa);
 }