From patchwork Fri Jun 18 15:03:25 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 56196 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 D2810B7D86 for ; Sat, 19 Jun 2010 01:05:28 +1000 (EST) Received: from localhost ([127.0.0.1]:51908 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OPd8H-0007wJ-TF for incoming@patchwork.ozlabs.org; Fri, 18 Jun 2010 11:05:26 -0400 Received: from [140.186.70.92] (port=52878 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OPd6h-0007tV-7F for qemu-devel@nongnu.org; Fri, 18 Jun 2010 11:03:48 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1OPd6f-0007M5-UE for qemu-devel@nongnu.org; Fri, 18 Jun 2010 11:03:46 -0400 Received: from mx1.redhat.com ([209.132.183.28]:41787) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OPd6f-0007Lt-L8 for qemu-devel@nongnu.org; Fri, 18 Jun 2010 11:03:45 -0400 Received: from int-mx01.intmail.prod.int.phx2.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o5IF3i6K024731 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Fri, 18 Jun 2010 11:03:45 -0400 Received: from localhost.localdomain (vpn1-6-103.ams2.redhat.com [10.36.6.103]) by int-mx01.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id o5IF3dsW028608; Fri, 18 Jun 2010 11:03:43 -0400 From: Kevin Wolf To: qemu-devel@nongnu.org Date: Fri, 18 Jun 2010 17:03:25 +0200 Message-Id: <1276873409-8235-3-git-send-email-kwolf@redhat.com> In-Reply-To: <1276873409-8235-1-git-send-email-kwolf@redhat.com> References: <1276873409-8235-1-git-send-email-kwolf@redhat.com> X-Scanned-By: MIMEDefang 2.67 on 10.5.11.11 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. Cc: kwolf@redhat.com Subject: [Qemu-devel] [PATCH 2/6] cow: Use bdrv_(p)write_sync for metadata writes 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 Use bdrv_(p)write_sync to ensure metadata integrity in case of a crash. While at it, correct the wrong usage of errno. Signed-off-by: Kevin Wolf --- block/cow.c | 20 +++++++++++--------- 1 files changed, 11 insertions(+), 9 deletions(-) diff --git a/block/cow.c b/block/cow.c index d146434..eedcc48 100644 --- a/block/cow.c +++ b/block/cow.c @@ -97,17 +97,18 @@ static inline int cow_set_bit(BlockDriverState *bs, int64_t bitnum) { uint64_t offset = sizeof(struct cow_header_v2) + bitnum / 8; uint8_t bitmap; + int ret; - if (bdrv_pread(bs->file, offset, &bitmap, sizeof(bitmap)) != - sizeof(bitmap)) { - return -errno; + ret = bdrv_pread(bs->file, offset, &bitmap, sizeof(bitmap)); + if (ret < 0) { + return ret; } bitmap |= (1 << (bitnum % 8)); - if (bdrv_pwrite(bs->file, offset, &bitmap, sizeof(bitmap)) != - sizeof(bitmap)) { - return -errno; + ret = bdrv_pwrite_sync(bs->file, offset, &bitmap, sizeof(bitmap)); + if (ret < 0) { + return ret; } return 0; } @@ -116,10 +117,11 @@ static inline int is_bit_set(BlockDriverState *bs, int64_t bitnum) { uint64_t offset = sizeof(struct cow_header_v2) + bitnum / 8; uint8_t bitmap; + int ret; - if (bdrv_pread(bs->file, offset, &bitmap, sizeof(bitmap)) != - sizeof(bitmap)) { - return -errno; + ret = bdrv_pread(bs->file, offset, &bitmap, sizeof(bitmap)); + if (ret < 0) { + return ret; } return !!(bitmap & (1 << (bitnum % 8)));