From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38564) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1X6efh-0004fV-Fo for qemu-devel@nongnu.org; Mon, 14 Jul 2014 07:44:00 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1X6efY-0005NO-SR for qemu-devel@nongnu.org; Mon, 14 Jul 2014 07:43:53 -0400 Received: from mx1.redhat.com ([209.132.183.28]:33022) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1X6efY-0005Ms-Jq for qemu-devel@nongnu.org; Mon, 14 Jul 2014 07:43:44 -0400 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s6EBhieg018973 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Mon, 14 Jul 2014 07:43:44 -0400 From: Kevin Wolf Date: Mon, 14 Jul 2014 13:43:10 +0200 Message-Id: <1405338192-18850-21-git-send-email-kwolf@redhat.com> In-Reply-To: <1405338192-18850-1-git-send-email-kwolf@redhat.com> References: <1405338192-18850-1-git-send-email-kwolf@redhat.com> Subject: [Qemu-devel] [PULL v2 for-2.1 20/22] virtio-blk: Bypass error action and I/O accounting on invalid r/w List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: kwolf@redhat.com From: Markus Armbruster When a device model's I/O operation fails, we execute the error action. This lets layers above QEMU implement thin provisioning, or attempt to correct errors before they reach the guest. But when the I/O operation fails because it's invalid, reporting the error to the guest is the only sensible action. If the guest's read or write asks for an invalid sector range, fail the request right away, without considering the error action. No change with error action BDRV_ACTION_REPORT. Furthermore, bypass I/O accounting, because we want to track only I/O that actually reaches the block layer. The next commit will extend "invalid sector range" to cover attempts to read/write beyond the end of the medium. Signed-off-by: Markus Armbruster Signed-off-by: Kevin Wolf --- hw/block/virtio-blk.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c index 075e6e6..e6e6276 100644 --- a/hw/block/virtio-blk.c +++ b/hw/block/virtio-blk.c @@ -307,15 +307,16 @@ static void virtio_blk_handle_write(VirtIOBlockReq *req, MultiReqBuffer *mrb) sector = virtio_ldq_p(VIRTIO_DEVICE(req->dev), &req->out.sector); - bdrv_acct_start(req->dev->bs, &req->acct, req->qiov.size, BDRV_ACCT_WRITE); - trace_virtio_blk_handle_write(req, sector, req->qiov.size / 512); if (!virtio_blk_sect_range_ok(req->dev, sector, req->qiov.size)) { - virtio_blk_rw_complete(req, -EIO); + virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR); + virtio_blk_free_request(req); return; } + bdrv_acct_start(req->dev->bs, &req->acct, req->qiov.size, BDRV_ACCT_WRITE); + if (mrb->num_writes == 32) { virtio_submit_multiwrite(req->dev->bs, mrb); } @@ -337,14 +338,15 @@ static void virtio_blk_handle_read(VirtIOBlockReq *req) sector = virtio_ldq_p(VIRTIO_DEVICE(req->dev), &req->out.sector); - bdrv_acct_start(req->dev->bs, &req->acct, req->qiov.size, BDRV_ACCT_READ); - trace_virtio_blk_handle_read(req, sector, req->qiov.size / 512); if (!virtio_blk_sect_range_ok(req->dev, sector, req->qiov.size)) { - virtio_blk_rw_complete(req, -EIO); + virtio_blk_req_complete(req, VIRTIO_BLK_S_IOERR); + virtio_blk_free_request(req); return; } + + bdrv_acct_start(req->dev->bs, &req->acct, req->qiov.size, BDRV_ACCT_READ); bdrv_aio_readv(req->dev->bs, sector, &req->qiov, req->qiov.size / BDRV_SECTOR_SIZE, virtio_blk_rw_complete, req); -- 1.8.3.1