From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752018AbcF1Cj1 (ORCPT ); Mon, 27 Jun 2016 22:39:27 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53170 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751740AbcF1CjZ (ORCPT ); Mon, 27 Jun 2016 22:39:25 -0400 From: Fam Zheng To: linux-kernel@vger.kernel.org Cc: "Michael S. Tsirkin" , virtualization@lists.linux-foundation.org, famz@redhat.com Subject: [PATCH] virtio-blk: Generate uevent after attribute available Date: Tue, 28 Jun 2016 10:39:15 +0800 Message-Id: <20160628023915.6012-1-famz@redhat.com> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Tue, 28 Jun 2016 02:39:24 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Userspace listens to the KOBJ_ADD uevent generated in add_disk. At that point we haven't created the serial attribute file, therefore depending on how fast udev reacts, the /dev/disk/by-id/ entry doesn't always get created. This race condition can be easily reproduced by hot plugging a number of virtio-blk disks. Also in systemd, there used to be a related workaround in udev rules called 'WAIT_FOR="serial"', but it is removed in later versions. Now let's generate a KOBJ_CHANGE event after the attributes are ready. Signed-off-by: Fam Zheng --- drivers/block/virtio_blk.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 42758b5..5056007 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -567,6 +567,7 @@ static int virtblk_probe(struct virtio_device *vdev) { struct virtio_blk *vblk; struct request_queue *q; + struct device *ddev; int err, index; u64 cap; @@ -746,6 +747,8 @@ static int virtblk_probe(struct virtio_device *vdev) &dev_attr_cache_type_ro); if (err) goto out_del_disk; + ddev = disk_to_dev(vblk->disk); + kobject_uevent(&ddev->kobj, KOBJ_CHANGE); return 0; out_del_disk: -- 2.9.0