1 files changed, 28 insertions, 0 deletions

diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 2d6191aa5948..7a93b3f68849 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -281,6 +281,27 @@ static int index_to_minor(int index)
         return index << PART_BITS;
 }
 
+static ssize_t virtblk_serial_show(struct device *dev,
+                                struct device_attribute *attr, char *buf)
+{
+        struct gendisk *disk = dev_to_disk(dev);
+        int err;
+
+        /* sysfs gives us a PAGE_SIZE buffer */
+        BUILD_BUG_ON(PAGE_SIZE < VIRTIO_BLK_ID_BYTES);
+
+        buf[VIRTIO_BLK_ID_BYTES] = '\0';
+        err = virtblk_get_id(disk, buf);
+        if (!err)
+                return strlen(buf);
+
+        if (err == -EIO) /* Unsupported? Make it empty. */
+                return 0;
+
+        return err;
+}
+DEVICE_ATTR(serial, S_IRUGO, virtblk_serial_show, NULL);
+
 static int __devinit virtblk_probe(struct virtio_device *vdev)
 {
         struct virtio_blk *vblk;
@@ -465,8 +486,15 @@ static int __devinit virtblk_probe(struct virtio_device *vdev)
 
 
         add_disk(vblk->disk);
+        err = device_create_file(disk_to_dev(vblk->disk), &dev_attr_serial);
+        if (err)
+                goto out_del_disk;
+
         return 0;
 
+out_del_disk:
+        del_gendisk(vblk->disk);
+        blk_cleanup_queue(vblk->disk->queue);
 out_put_disk:
         put_disk(vblk->disk);
 out_mempool: