diff --git a/drivers/staging/zram/zram_drv.c b/drivers/staging/zram/zram_drv.c
index 9057520c0e40..8d12e803aa0a 100644
--- a/drivers/staging/zram/zram_drv.c
+++ b/drivers/staging/zram/zram_drv.c
@@ -582,7 +582,9 @@ static void zram_slot_free_notify(struct block_device *bdev,
 	struct zram *zram;
 
 	zram = bdev->bd_disk->private_data;
+	down_write(&zram->lock);
 	zram_free_page(zram, index);
+	up_write(&zram->lock);
 	zram_stat64_inc(zram, &zram->stats.notify_free);
 }
 
diff --git a/drivers/staging/zram/zram_drv.h b/drivers/staging/zram/zram_drv.h
index 2d1a3f1e8edb..d542eee81357 100644
--- a/drivers/staging/zram/zram_drv.h
+++ b/drivers/staging/zram/zram_drv.h
@@ -93,8 +93,9 @@ struct zram_meta {
 struct zram {
 	struct zram_meta *meta;
 	spinlock_t stat64_lock;	/* protect 64-bit stats */
-	struct rw_semaphore lock; /* protect compression buffers and table
-				   * against concurrent read and writes */
+	struct rw_semaphore lock; /* protect compression buffers, table,
+				   * 32bit stat counters against concurrent
+				   * notifications, reads and writes */
 	struct request_queue *queue;
 	struct gendisk *disk;
 	int init_done;