From patchwork Tue Jun 5 22:04:53 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Bonzini X-Patchwork-Id: 163187 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 6C6ADB6F9A for ; Wed, 6 Jun 2012 08:56:46 +1000 (EST) Received: from localhost ([::1]:59632 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Sc1t4-0006b0-UW for incoming@patchwork.ozlabs.org; Tue, 05 Jun 2012 18:06:02 -0400 Received: from eggs.gnu.org ([208.118.235.92]:60629) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Sc1sO-0004eZ-Bn for qemu-devel@nongnu.org; Tue, 05 Jun 2012 18:05:21 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Sc1sM-00015x-Kj for qemu-devel@nongnu.org; Tue, 05 Jun 2012 18:05:19 -0400 Received: from mail-pb0-f45.google.com ([209.85.160.45]:40874) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Sc1sM-0000zZ-Bm for qemu-devel@nongnu.org; Tue, 05 Jun 2012 18:05:18 -0400 Received: by mail-pb0-f45.google.com with SMTP id ro12so8716928pbb.4 for ; Tue, 05 Jun 2012 15:05:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=sender:from:to:cc:subject:date:message-id:x-mailer:in-reply-to :references; bh=XwvRdWIh2+u4higqk6Tx/JwlG6wQWJI6e/L7RmdjBqo=; b=co6cxxtnpKXEIvMWNRjeoeENxxsZhY3zRQMYCV65EbmABPisV4nygBf4UdOF/BNjev moxafuLRIRn9nGDkovmUFRecJO0VsW45noEe0ms6OqSsBNgYKT+Z3vW1fWhsBfik3YnD dw+4QDI0cl0m0MfeMxIc5k52HUBKfczlMEJHbP+oKKH6v//+r5BUEKyjBRSPgX62EIaC radN4jhDf8AHnB+EnCiiVre3I9hX1A8+OOMyjjCRoByjjl/45Emlg1cQ8N47ify7ybrC mXZuxMEqVuJSKRlrJmW4qvTntqK1k9LOqakmv7CrZkxLkvC1DIsxJN8aQRIOV2Xd0gf+ lquw== Received: by 10.68.228.39 with SMTP id sf7mr51774785pbc.45.1338933917533; Tue, 05 Jun 2012 15:05:17 -0700 (PDT) Received: from yakj.usersys.redhat.com (222-151-096-013.jp.fiberbit.net. [222.151.96.13]) by mx.google.com with ESMTPS id ok6sm108065pbb.29.2012.06.05.15.05.15 (version=TLSv1/SSLv3 cipher=OTHER); Tue, 05 Jun 2012 15:05:16 -0700 (PDT) From: Paolo Bonzini To: qemu-devel@nongnu.org Date: Wed, 6 Jun 2012 00:04:53 +0200 Message-Id: <1338933895-20677-6-git-send-email-pbonzini@redhat.com> X-Mailer: git-send-email 1.7.10.1 In-Reply-To: <1338933895-20677-1-git-send-email-pbonzini@redhat.com> References: <1338933895-20677-1-git-send-email-pbonzini@redhat.com> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 209.85.160.45 Cc: kwolf@redhat.com Subject: [Qemu-devel] [PATCH v3 5/7] block: always open drivers in writeback mode X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Formats are entirely in charge of flushes for metadata writes. For guest-initiated writes, a writethrough cache is faked in the block layer. So we can always open in writeback mode. Signed-off-by: Paolo Bonzini --- block.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/block.c b/block.c index e4396a6..48528fd 100644 --- a/block.c +++ b/block.c @@ -649,12 +649,13 @@ static int bdrv_open_common(BlockDriverState *bs, const char *filename, bs->opaque = g_malloc0(drv->instance_size); bs->enable_write_cache = !!(flags & BDRV_O_CACHE_WB); + open_flags = flags | BDRV_O_CACHE_WB; /* * Clear flags that are internal to the block layer before opening the * image. */ - open_flags = flags & ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING); + open_flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING); /* * Snapshots should be writable.