diff --git a/fs/xfs/xfs_fsmap.c b/fs/xfs/xfs_fsmap.c
index 901918116d3d..6bd6ab56ca9f 100644
--- a/fs/xfs/xfs_fsmap.c
+++ b/fs/xfs/xfs_fsmap.c
@@ -529,7 +529,7 @@ __xfs_getfsmap_rtdev(
 	uint64_t			eofs;
 	int				error = 0;
 
-	eofs = XFS_FSB_TO_BB(mp, mp->m_sb.sb_rblocks);
+	eofs = XFS_FSB_TO_BB(mp, mp->m_sb.sb_rextents * mp->m_sb.sb_rextsize);
 	if (keys[0].fmr_physical >= eofs)
 		return 0;
 	start_rtb = XFS_BB_TO_FSBT(mp,