diff --git a/fs/block_dev.c b/fs/block_dev.c
index 3f36df7..17c7618 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -723,11 +723,11 @@
 	if (!bo)
 		return -ENOMEM;
 
-	down(&bdev->bd_sem);
+	mutex_lock(&bdev->bd_mutex);
 	res = bd_claim(bdev, holder);
 	if (res || !add_bd_holder(bdev, bo))
 		free_bd_holder(bo);
-	up(&bdev->bd_sem);
+	mutex_unlock(&bdev->bd_mutex);
 
 	return res;
 }
@@ -748,11 +748,11 @@
 	if (!kobj)
 		return;
 
-	down(&bdev->bd_sem);
+	mutex_lock(&bdev->bd_mutex);
 	bd_release(bdev);
 	if ((bo = del_bd_holder(bdev, kobj)))
 		free_bd_holder(bo);
-	up(&bdev->bd_sem);
+	mutex_unlock(&bdev->bd_mutex);
 }
 
 /**