From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:33633) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Timt2-0007c8-FY for qemu-devel@nongnu.org; Wed, 12 Dec 2012 09:02:18 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Timss-0007ZI-WF for qemu-devel@nongnu.org; Wed, 12 Dec 2012 09:02:12 -0500 Received: from mx1.redhat.com ([209.132.183.28]:51708) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Timss-0007ZB-Pa for qemu-devel@nongnu.org; Wed, 12 Dec 2012 09:02:02 -0500 Message-ID: <50C88E53.4080200@redhat.com> Date: Wed, 12 Dec 2012 15:01:55 +0100 From: Paolo Bonzini MIME-Version: 1.0 References: <20121212105101.GA6461@redhat.com> <20121212135050.GC16270@stefanha-thinkpad.redhat.com> In-Reply-To: <20121212135050.GC16270@stefanha-thinkpad.redhat.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCHv2] virtio: verify that all outstanding buffers are flushed List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stefan Hajnoczi Cc: Anthony Liguori , "Michael S. Tsirkin" , Rusty Russell , qemu-devel@nongnu.org, Avi Kivity , Stefan Hajnoczi Il 12/12/2012 14:50, Stefan Hajnoczi ha scritto: > VirtIOBlock->rq can trigger the assertion. > > IIUC hw/virtio-blk.c may handle I/O errors by keeping the request > pending and on a list (->rq). This allows the user to restart them > after, for example, adding more space to the host file system containing > the disk image file. > > We keep a list of failed requests and we migrate this list. So I think > inuse != 0 when migrating with pending failed I/O requests. Same for virtio-scsi. Each request in that case is sent as part of the SCSIDevice that it refers to, via callbacks in SCSIBusInfo. Paolo