xfs: cross-reference reverse-mapping btree

When scrubbing various btrees, we should cross-reference the records
with the reverse mapping btree and ensure that traversing the btree
finds the same number of blocks that the rmapbt thinks are owned by
that btree.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

1 files changed, 53 insertions, 0 deletions

diff --git a/fs/xfs/scrub/common.c b/fs/xfs/scrub/common.c
index 68fea09cd673..f5df8f2859d7 100644
--- a/fs/xfs/scrub/common.c
+++ b/fs/xfs/scrub/common.c
@@ -325,6 +325,59 @@ xfs_scrub_set_incomplete(
 }
 
 /*
+ * rmap scrubbing -- compute the number of blocks with a given owner,
+ * at least according to the reverse mapping data.
+ */
+
+struct xfs_scrub_rmap_ownedby_info {
+	struct xfs_owner_info	*oinfo;
+	xfs_filblks_t		*blocks;
+};
+
+STATIC int
+xfs_scrub_count_rmap_ownedby_irec(
+	struct xfs_btree_cur			*cur,
+	struct xfs_rmap_irec			*rec,
+	void					*priv)
+{
+	struct xfs_scrub_rmap_ownedby_info	*sroi = priv;
+	bool					irec_attr;
+	bool					oinfo_attr;
+
+	irec_attr = rec->rm_flags & XFS_RMAP_ATTR_FORK;
+	oinfo_attr = sroi->oinfo->oi_flags & XFS_OWNER_INFO_ATTR_FORK;
+
+	if (rec->rm_owner != sroi->oinfo->oi_owner)
+		return 0;
+
+	if (XFS_RMAP_NON_INODE_OWNER(rec->rm_owner) || irec_attr == oinfo_attr)
+		(*sroi->blocks) += rec->rm_blockcount;
+
+	return 0;
+}
+
+/*
+ * Calculate the number of blocks the rmap thinks are owned by something.
+ * The caller should pass us an rmapbt cursor.
+ */
+int
+xfs_scrub_count_rmap_ownedby_ag(
+	struct xfs_scrub_context		*sc,
+	struct xfs_btree_cur			*cur,
+	struct xfs_owner_info			*oinfo,
+	xfs_filblks_t				*blocks)
+{
+	struct xfs_scrub_rmap_ownedby_info	sroi;
+
+	sroi.oinfo = oinfo;
+	*blocks = 0;
+	sroi.blocks = blocks;
+
+	return xfs_rmap_query_all(cur, xfs_scrub_count_rmap_ownedby_irec,
+			&sroi);
+}
+
+/*
  * AG scrubbing
  *
  * These helpers facilitate locking an allocation group's header