diff --git a/fs/xfs/xfs_fs.h b/fs/xfs/xfs_fs.h
index 8f6fc1a..c13fed8 100644
--- a/fs/xfs/xfs_fs.h
+++ b/fs/xfs/xfs_fs.h
@@ -249,6 +249,11 @@
 #define XFS_MAX_LOG_BYTES \
 	((2 * 1024 * 1024 * 1024ULL) - XFS_MIN_LOG_BYTES)
 
+/* Used for sanity checks on superblock */
+#define XFS_MAX_DBLOCKS(s) ((xfs_drfsbno_t)(s)->sb_agcount * (s)->sb_agblocks)
+#define XFS_MIN_DBLOCKS(s) ((xfs_drfsbno_t)((s)->sb_agcount - 1) *	\
+			 (s)->sb_agblocks + XFS_MIN_AG_BLOCKS)
+
 /*
  * Structures for XFS_IOC_FSGROWFSDATA, XFS_IOC_FSGROWFSLOG & XFS_IOC_FSGROWFSRT
  */