From patchwork Tue Jun 22 14:09:25 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kevin Wolf X-Patchwork-Id: 56513 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 63D47B6EFE for ; Wed, 23 Jun 2010 00:25:59 +1000 (EST) Received: from localhost ([127.0.0.1]:53223 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OR4QG-0006Ko-JM for incoming@patchwork.ozlabs.org; Tue, 22 Jun 2010 10:25:56 -0400 Received: from [140.186.70.92] (port=43330 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OR4Ao-0005it-4W for qemu-devel@nongnu.org; Tue, 22 Jun 2010 10:10:00 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1OR4Am-0007ck-5I for qemu-devel@nongnu.org; Tue, 22 Jun 2010 10:09:57 -0400 Received: from mx1.redhat.com ([209.132.183.28]:32404) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OR4Al-0007cP-V3 for qemu-devel@nongnu.org; Tue, 22 Jun 2010 10:09:56 -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 o5ME9oiw022421 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Tue, 22 Jun 2010 10:09:50 -0400 Received: from localhost.localdomain (dhcp-5-217.str.redhat.com [10.32.5.217]) by int-mx01.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id o5ME9fjq024621; Tue, 22 Jun 2010 10:09:49 -0400 From: Kevin Wolf To: anthony@codemonkey.ws Date: Tue, 22 Jun 2010 16:09:25 +0200 Message-Id: <1277215773-27357-7-git-send-email-kwolf@redhat.com> In-Reply-To: <1277215773-27357-1-git-send-email-kwolf@redhat.com> References: <1277215773-27357-1-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, qemu-devel@nongnu.org Subject: [Qemu-devel] [PATCH 06/14] 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)));