xfs: scrub rmap btrees

Check the reverse mapping records to make sure that the contents
make sense.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
diff --git a/fs/xfs/scrub/common.h b/fs/xfs/scrub/common.h
index 17830b8..7922775 100644
--- a/fs/xfs/scrub/common.h
+++ b/fs/xfs/scrub/common.h
@@ -83,6 +83,8 @@ int xfs_scrub_setup_ag_allocbt(struct xfs_scrub_context *sc,
 			       struct xfs_inode *ip);
 int xfs_scrub_setup_ag_iallocbt(struct xfs_scrub_context *sc,
 				struct xfs_inode *ip);
+int xfs_scrub_setup_ag_rmapbt(struct xfs_scrub_context *sc,
+			      struct xfs_inode *ip);
 
 
 void xfs_scrub_ag_free(struct xfs_scrub_context *sc, struct xfs_scrub_ag *sa);