From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755185Ab3KAWEt (ORCPT ); Fri, 1 Nov 2013 18:04:49 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:54992 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755075Ab3KAWEr (ORCPT ); Fri, 1 Nov 2013 18:04:47 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jason Wang , Sasha Levin , Rusty Russell , "Michael S. Tsirkin" Subject: [PATCH 3.10 25/54] virtio-net: fix the race between channels setting and refill Date: Fri, 1 Nov 2013 15:03:53 -0700 Message-Id: <20131101220214.144682621@linuxfoundation.org> X-Mailer: git-send-email 1.8.4.3.gca3854a In-Reply-To: <20131101220211.311926234@linuxfoundation.org> References: <20131101220211.311926234@linuxfoundation.org> User-Agent: quilt/0.60-5.1.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jason Wang [ Upstream commit 9b9cd8024a2882e896c65222aa421d461354e3f2 ] Commit 55257d72bd1c51f25106350f4983ec19f62ed1fa (virtio-net: fill only rx queues which are being used) tries to refill on demand when changing the number of channels by call try_refill_recv() directly, this may race: - the refill work who may do the refill in the same time - the try_refill_recv() called in bh since napi was not disabled Which may led guest complain during setting channels: virtio_net virtio0: input.1:id 0 is not a head! Solve this issue by scheduling a refill work which can guarantee the serialization of refill. Signed-off-by: Jason Wang Cc: Sasha Levin Cc: Rusty Russell Cc: Michael S. Tsirkin Signed-off-by: Rusty Russell Signed-off-by: Greg Kroah-Hartman --- drivers/net/virtio_net.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -902,7 +902,6 @@ static int virtnet_set_queues(struct vir struct scatterlist sg; struct virtio_net_ctrl_mq s; struct net_device *dev = vi->dev; - int i; if (!vi->has_cvq || !virtio_has_feature(vi->vdev, VIRTIO_NET_F_MQ)) return 0; @@ -916,10 +915,8 @@ static int virtnet_set_queues(struct vir queue_pairs); return -EINVAL; } else { - for (i = vi->curr_queue_pairs; i < queue_pairs; i++) - if (!try_fill_recv(&vi->rq[i], GFP_KERNEL)) - schedule_delayed_work(&vi->refill, 0); vi->curr_queue_pairs = queue_pairs; + schedule_delayed_work(&vi->refill, 0); } return 0;