diff --git a/kmod/src/inode.c b/kmod/src/inode.c
index 6f1b82d2..4329905c 100644
--- a/kmod/src/inode.c
+++ b/kmod/src/inode.c
@@ -1850,8 +1850,7 @@ static void inode_orphan_scan_worker(struct work_struct *work)
 		}
 
 		/* get an omap that covers the orphaned ino */
-		group_nr = ino >> SCOUTFS_OPEN_INO_MAP_SHIFT;
-		bit_nr = ino & SCOUTFS_OPEN_INO_MAP_MASK;
+		scoutfs_omap_calc_group_nrs(ino, &group_nr, &bit_nr);
 
 		if (le64_to_cpu(omap.args.group_nr) != group_nr) {
 			ret = scoutfs_client_open_ino_map(sb, group_nr, &omap);
diff --git a/kmod/src/omap.c b/kmod/src/omap.c
index 529cfda4..a441897b 100644
--- a/kmod/src/omap.c
+++ b/kmod/src/omap.c
@@ -232,7 +232,7 @@ static void free_rids(struct omap_rid_list *list)
 	}
 }
 
-static void calc_group_nrs(u64 ino, u64 *group_nr, int *bit_nr)
+void scoutfs_omap_calc_group_nrs(u64 ino, u64 *group_nr, int *bit_nr)
 {
 	*group_nr = ino >> SCOUTFS_OPEN_INO_MAP_SHIFT;
 	*bit_nr = ino & SCOUTFS_OPEN_INO_MAP_MASK;
@@ -298,7 +298,7 @@ int scoutfs_omap_inc(struct super_block *sb, u64 ino)
 	bool found;
 	int ret = 0;
 
-	calc_group_nrs(ino, &group_nr, &bit_nr);
+	scoutfs_omap_calc_group_nrs(ino, &group_nr, &bit_nr);
 
 retry:
 	found = false;
@@ -354,7 +354,7 @@ void scoutfs_omap_dec(struct super_block *sb, u64 ino)
 	u64 group_nr;
 	int bit_nr;
 
-	calc_group_nrs(ino, &group_nr, &bit_nr);
+	scoutfs_omap_calc_group_nrs(ino, &group_nr, &bit_nr);
 
 	rcu_read_lock();
 	group = rhashtable_lookup(&ominf->group_ht, &group_nr, group_ht_params);
@@ -950,7 +950,7 @@ int scoutfs_omap_should_delete(struct super_block *sb, struct inode *inode,
 		goto out;
 	}
 
-	calc_group_nrs(ino, &group_nr, &bit_nr);
+	scoutfs_omap_calc_group_nrs(ino, &group_nr, &bit_nr);
 
 	/* only one request to refresh the map at a time */
 	ret = get_current_lock_data(sb, lock, &ldata, group_nr);
diff --git a/kmod/src/omap.h b/kmod/src/omap.h
index 9a2d1e0b..4c6787a2 100644
--- a/kmod/src/omap.h
+++ b/kmod/src/omap.h
@@ -8,6 +8,7 @@ int scoutfs_omap_should_delete(struct super_block *sb, struct inode *inode,
 void scoutfs_omap_free_lock_data(struct scoutfs_omap_lock_data *ldata);
 int scoutfs_omap_client_handle_request(struct super_block *sb, u64 id,
 				       struct scoutfs_open_ino_map_args *args);
+void scoutfs_omap_calc_group_nrs(u64 ino, u64 *group_nr, int *bit_nr);
 
 int scoutfs_omap_add_rid(struct super_block *sb, u64 rid);
 int scoutfs_omap_remove_rid(struct super_block *sb, u64 rid);