From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NagNW-0006sS-0s for qemu-devel@nongnu.org; Thu, 28 Jan 2010 21:14:34 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1NagNR-0006qQ-8K for qemu-devel@nongnu.org; Thu, 28 Jan 2010 21:14:33 -0500 Received: from [199.232.76.173] (port=37652 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NagNQ-0006qD-Pa for qemu-devel@nongnu.org; Thu, 28 Jan 2010 21:14:28 -0500 Received: from mga05.intel.com ([192.55.52.89]:21468 helo=fmsmga101.fm.intel.com) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1NagNQ-0003Rn-AG for qemu-devel@nongnu.org; Thu, 28 Jan 2010 21:14:28 -0500 From: Sheng Yang Subject: Re: [Qemu-devel] [PATCH] Fix qemu-img can't create qcow image based =?iso-8859-15?q?on=09read-only?= image Date: Fri, 29 Jan 2010 10:13:21 +0800 References: <1264656166-6360-1-git-send-email-sheng@linux.intel.com> <4B615622.8090902@redhat.com> In-Reply-To: <4B615622.8090902@redhat.com> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Message-Id: <201001291013.21329.sheng@linux.intel.com> List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Anthony Liguori Cc: Kevin Wolf , Marcelo Tosatti , qemu-devel@nongnu.org, kvm@vger.kernel.org, Naphtali Sprei On Thursday 28 January 2010 17:17:22 Kevin Wolf wrote: > Am 28.01.2010 06:22, schrieb Sheng Yang: > > 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); > > Shouldn't it be read-only here, too? Yes. Seems you guys are OK with this solution(and I think it's reasonable to remove the fall back). I would update the patch, hopefully it can be applied soon and picked up by Marcelo to resolve our block issue... -- regards Yang, Sheng