From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53846) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a0sJs-0004zF-Jw for qemu-devel@nongnu.org; Mon, 23 Nov 2015 09:42:17 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1a0sJr-0000wn-Mq for qemu-devel@nongnu.org; Mon, 23 Nov 2015 09:42:16 -0500 References: <1448239280-15025-1-git-send-email-famz@redhat.com> From: Paolo Bonzini Message-ID: <565325B4.6040103@redhat.com> Date: Mon, 23 Nov 2015 15:41:56 +0100 MIME-Version: 1.0 In-Reply-To: <1448239280-15025-1-git-send-email-famz@redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] virtio-blk: Move resetting of req->mr_next to virtio_blk_handle_rw_error List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Fam Zheng , qemu-devel@nongnu.org Cc: Kevin Wolf , lvivier@redhat.com, qemu-block@nongnu.org, pl@kamp.de, qemu-stable@nongnu.org, Stefan Hajnoczi , dgibson@redhat.com On 23/11/2015 01:41, Fam Zheng wrote: > "werror=report" would free the req in virtio_blk_handle_rw_error, we > mustn't write to it in that case. > > Reported-by: Paolo Bonzini > Signed-off-by: Fam Zheng > --- > hw/block/virtio-blk.c | 7 +++---- > 1 file changed, 3 insertions(+), 4 deletions(-) > > diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c > index 848f3fe..756ae5c 100644 > --- a/hw/block/virtio-blk.c > +++ b/hw/block/virtio-blk.c > @@ -72,6 +72,9 @@ static int virtio_blk_handle_rw_error(VirtIOBlockReq *req, int error, > VirtIOBlock *s = req->dev; > > if (action == BLOCK_ERROR_ACTION_STOP) { > + /* Break the link as the next request is going to be parsed from the > + * ring again. Otherwise we may end up doing a double completion! */ > + req->mr_next = NULL; > req->next = s->rq; > s->rq = req; > } else if (action == BLOCK_ERROR_ACTION_REPORT) { > @@ -112,10 +115,6 @@ static void virtio_blk_rw_complete(void *opaque, int ret) > * happen on the other side of the migration). > */ > if (virtio_blk_handle_rw_error(req, -ret, is_read)) { > - /* Break the link in case the next request is added to the > - * restart queue and is going to be parsed from the ring again. > - */ > - req->mr_next = NULL; > continue; > } > } > Reviewed-by: Paolo Bonzini