From patchwork Thu Jan 28 05:22:46 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sheng Yang X-Patchwork-Id: 43848 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 0332CB7CFB for ; Thu, 28 Jan 2010 16:29:43 +1100 (EST) Received: from localhost ([127.0.0.1]:36633 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NaMsT-0001Pj-1s for incoming@patchwork.ozlabs.org; Thu, 28 Jan 2010 00:25:13 -0500 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NaMrD-0001OT-7N for qemu-devel@nongnu.org; Thu, 28 Jan 2010 00:23:55 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1NaMr8-0001M6-Gl for qemu-devel@nongnu.org; Thu, 28 Jan 2010 00:23:54 -0500 Received: from [199.232.76.173] (port=39348 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NaMr8-0001M3-B0 for qemu-devel@nongnu.org; Thu, 28 Jan 2010 00:23:50 -0500 Received: from mga11.intel.com ([192.55.52.93]:58832) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1NaMr8-00009Z-0R for qemu-devel@nongnu.org; Thu, 28 Jan 2010 00:23:50 -0500 Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga102.fm.intel.com with ESMTP; 27 Jan 2010 21:22:52 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.49,357,1262592000"; d="scan'208";a="535281666" Received: from syang10-desktop.sh.intel.com (HELO syang10-desktop) ([10.239.36.165]) by fmsmga002.fm.intel.com with ESMTP; 27 Jan 2010 21:23:27 -0800 Received: from yasker by syang10-desktop with local (Exim 4.69) (envelope-from ) id 1NaMq8-0001f4-6q; Thu, 28 Jan 2010 13:22:48 +0800 From: Sheng Yang To: Anthony Liguori Date: Thu, 28 Jan 2010 13:22:46 +0800 Message-Id: <1264656166-6360-1-git-send-email-sheng@linux.intel.com> X-Mailer: git-send-email 1.6.3.3 X-detected-operating-system: by monty-python.gnu.org: Genre and OS details not recognized. Cc: Marcelo Tosatti , Naphtali Sprei , qemu-devel@nongnu.org, kvm@vger.kernel.org, Sheng Yang Subject: [Qemu-devel] [PATCH] Fix qemu-img can't create qcow image based on read-only image 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 Commit 03cbdac7 "Disable fall-back to read-only when cannot open drive's file for read-write" result in read-only image can't be used as backed image in qemu-img. CC: Naphtali Sprei Signed-off-by: Sheng Yang --- This issue blocked our QA's KVM nightly test. But in fact, I don't like this patch, feeling uncomfortable to change long existed interface... Any alternative? Add a readonly command line would change the default behavior(I don't think fall back to readonly looks like a bug); or even revert the commit? What's the story behind it? qemu-img.c | 15 ++++++++++----- 1 files changed, 10 insertions(+), 5 deletions(-) diff --git a/qemu-img.c b/qemu-img.c index 3cea8ce..f8be5cb 100644 --- a/qemu-img.c +++ b/qemu-img.c @@ -188,11 +188,13 @@ static int read_password(char *buf, int buf_size) #endif static BlockDriverState *bdrv_new_open(const char *filename, - const char *fmt) + const char *fmt, + int readonly) { BlockDriverState *bs; BlockDriver *drv; char password[256]; + int flags = BRDV_O_FLAGS; bs = bdrv_new(""); if (!bs) @@ -204,7 +206,10 @@ static BlockDriverState *bdrv_new_open(const char *filename, } else { drv = NULL; } - if (bdrv_open2(bs, filename, BRDV_O_FLAGS | BDRV_O_RDWR, drv) < 0) { + if (!readonly) { + flags |= BDRV_O_RDWR; + } + if (bdrv_open2(bs, filename, flags, drv) < 0) { error("Could not open '%s'", filename); } if (bdrv_is_encrypted(bs)) { @@ -343,7 +348,7 @@ static int img_create(int argc, char **argv) } } - bs = bdrv_new_open(backing_file->value.s, fmt); + bs = bdrv_new_open(backing_file->value.s, fmt, 1); bdrv_get_geometry(bs, &size); size *= 512; bdrv_delete(bs); @@ -627,7 +632,7 @@ static int img_convert(int argc, char **argv) total_sectors = 0; for (bs_i = 0; bs_i < bs_n; bs_i++) { - bs[bs_i] = bdrv_new_open(argv[optind + bs_i], fmt); + bs[bs_i] = bdrv_new_open(argv[optind + bs_i], fmt, 0); if (!bs[bs_i]) error("Could not open '%s'", argv[optind + bs_i]); bdrv_get_geometry(bs[bs_i], &bs_sectors); @@ -685,7 +690,7 @@ static int img_convert(int argc, char **argv) } } - out_bs = bdrv_new_open(out_filename, out_fmt); + out_bs = bdrv_new_open(out_filename, out_fmt, 0); bs_i = 0; bs_offset = 0;