From patchwork Wed Mar 2 15:04:22 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ryan Harper X-Patchwork-Id: 85093 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [199.232.76.165]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 14D19B70E8 for ; Thu, 3 Mar 2011 02:11:10 +1100 (EST) Received: from localhost ([127.0.0.1]:51033 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Punhi-0008Og-Fx for incoming@patchwork.ozlabs.org; Wed, 02 Mar 2011 10:11:06 -0500 Received: from [140.186.70.92] (port=40747 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PunbH-0005B2-Uq for qemu-devel@nongnu.org; Wed, 02 Mar 2011 10:04:29 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1PunbG-0004xj-R7 for qemu-devel@nongnu.org; Wed, 02 Mar 2011 10:04:27 -0500 Received: from e37.co.us.ibm.com ([32.97.110.158]:51269) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1PunbG-0004xb-L1 for qemu-devel@nongnu.org; Wed, 02 Mar 2011 10:04:26 -0500 Received: from d03relay01.boulder.ibm.com (d03relay01.boulder.ibm.com [9.17.195.226]) by e37.co.us.ibm.com (8.14.4/8.13.1) with ESMTP id p22F1pTR016262 for ; Wed, 2 Mar 2011 08:01:51 -0700 Received: from d03av04.boulder.ibm.com (d03av04.boulder.ibm.com [9.17.195.170]) by d03relay01.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id p22F4PWn099972 for ; Wed, 2 Mar 2011 08:04:25 -0700 Received: from d03av04.boulder.ibm.com (loopback [127.0.0.1]) by d03av04.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id p22F21ML032664 for ; Wed, 2 Mar 2011 08:02:01 -0700 Received: from localhost.localdomain (frylock.austin.ibm.com [9.53.41.12]) by d03av04.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id p22F21Rf032580 for ; Wed, 2 Mar 2011 08:02:01 -0700 Received: by localhost.localdomain (Postfix, from userid 1000) id BE3AC1BF81; Wed, 2 Mar 2011 09:04:22 -0600 (CST) Date: Wed, 2 Mar 2011 09:04:22 -0600 From: Ryan Harper To: qemu-devel@nongnu.org Message-ID: <20110302150422.GA13257@us.ibm.com> Mime-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.6+20040907i X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6, seldom 2.4 (older, 4) X-Received-From: 32.97.110.158 Subject: [Qemu-devel] [PATCH] Don't allow multiwrites against a block device without underlying medium X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org If the block device has been closed, we no longer have a medium to submit IO against, check for this before submitting io. This prevents a segfault further in the code where we dereference elements of the block driver. Signed-off-by: Ryan Harper --- block.c | 5 +++++ 1 files changed, 5 insertions(+), 0 deletions(-) diff --git a/block.c b/block.c index 92dd3fe..534e1bc 100644 --- a/block.c +++ b/block.c @@ -2407,6 +2407,11 @@ int bdrv_aio_multiwrite(BlockDriverState *bs, BlockRequest *reqs, int num_reqs) return 0; } + /* don't submit writes if we don't have a medium */ + if (bs->drv == NULL) { + return -1; + } + // Create MultiwriteCB structure mcb = qemu_mallocz(sizeof(*mcb) + num_reqs * sizeof(*mcb->callbacks)); mcb->num_requests = 0;