diff --git a/kernel/lib_mapfree.c b/kernel/lib_mapfree.c
index bdc3eaea..a77ad530 100644
--- a/kernel/lib_mapfree.c
+++ b/kernel/lib_mapfree.c
@@ -48,7 +48,6 @@ DECLARE_RWSEM(mapfree_mutex);
 static
 LIST_HEAD(mapfree_list);
 
-static
 void mapfree_pages(struct mapfree_info *mf, int grace_keep)
 {
 	struct address_space *mapping;
diff --git a/kernel/lib_mapfree.h b/kernel/lib_mapfree.h
index 4eb7ffa9..8489b998 100644
--- a/kernel/lib_mapfree.h
+++ b/kernel/lib_mapfree.h
@@ -72,6 +72,8 @@ void mapfree_put(struct mapfree_info *mf);
 
 void mapfree_set(struct mapfree_info *mf, loff_t min, loff_t max);
 
+void mapfree_pages(struct mapfree_info *mf, int grace_keep);
+
 ////////////////// dirty IOs on the fly  //////////////////
 
 void mf_insert_dirty(struct mapfree_info *mf, struct dirty_info *di);
diff --git a/kernel/mars_bio.c b/kernel/mars_bio.c
index 6f7f17ac..307b8cf3 100644
--- a/kernel/mars_bio.c
+++ b/kernel/mars_bio.c
@@ -743,7 +743,7 @@ static int bio_switch(struct bio_brick *brick)
 				MARS_ERR("cannot open file '%s'\n", path);
 				goto done;
 			}
-			
+			mapfree_pages(brick->mf, -1);
 			if (unlikely(!(mapping = brick->mf->mf_filp->f_mapping) ||
 				     !(inode = mapping->host))) {
 				MARS_ERR("internal problem with '%s'\n", path);