diff --git a/fs/nilfs2/bmap.h b/fs/nilfs2/bmap.h
index de88ddf..379fda4 100644
--- a/fs/nilfs2/bmap.h
+++ b/fs/nilfs2/bmap.h
@@ -66,7 +66,7 @@
 	int (*bop_delete)(struct nilfs_bmap *, __u64);
 	void (*bop_clear)(struct nilfs_bmap *);
 
-	int (*bop_propagate)(const struct nilfs_bmap *, struct buffer_head *);
+	int (*bop_propagate)(struct nilfs_bmap *, struct buffer_head *);
 	void (*bop_lookup_dirty_buffers)(struct nilfs_bmap *,
 					 struct list_head *);
 
diff --git a/fs/nilfs2/btree.c b/fs/nilfs2/btree.c
index b2347f7..a2dc36c 100644
--- a/fs/nilfs2/btree.c
+++ b/fs/nilfs2/btree.c
@@ -1899,7 +1899,7 @@
 	return ret;
 }
 
-static int nilfs_btree_propagate(const struct nilfs_bmap *bmap,
+static int nilfs_btree_propagate(struct nilfs_bmap *bmap,
 				 struct buffer_head *bh)
 {
 	struct nilfs_btree *btree;
@@ -1942,7 +1942,7 @@
 	return ret;
 }
 
-static int nilfs_btree_propagate_gc(const struct nilfs_bmap *bmap,
+static int nilfs_btree_propagate_gc(struct nilfs_bmap *bmap,
 				    struct buffer_head *bh)
 {
 	return nilfs_dat_mark_dirty(nilfs_bmap_get_dat(bmap), bh->b_blocknr);
diff --git a/fs/nilfs2/direct.c b/fs/nilfs2/direct.c
index 32f1746..fd006ee 100644
--- a/fs/nilfs2/direct.c
+++ b/fs/nilfs2/direct.c
@@ -269,7 +269,7 @@
 	return 0;
 }
 
-static int nilfs_direct_propagate(const struct nilfs_bmap *bmap,
+static int nilfs_direct_propagate(struct nilfs_bmap *bmap,
 				  struct buffer_head *bh)
 {
 	struct nilfs_direct *direct = (struct nilfs_direct *)bmap;