From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:55372) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T9F1n-0003Ar-Ge for qemu-devel@nongnu.org; Wed, 05 Sep 2012 08:48:27 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1T9F1d-0005A9-UO for qemu-devel@nongnu.org; Wed, 05 Sep 2012 08:48:19 -0400 Received: from mx1.redhat.com ([209.132.183.28]:14198) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T9F1d-00059w-Kw for qemu-devel@nongnu.org; Wed, 05 Sep 2012 08:48:09 -0400 Message-ID: <504749EE.20903@redhat.com> Date: Wed, 05 Sep 2012 14:47:42 +0200 From: Kevin Wolf MIME-Version: 1.0 References: <431ff7f85fb9c83b5300360273322e6a0c76aee2.1346352124.git.jcody@redhat.com> In-Reply-To: <431ff7f85fb9c83b5300360273322e6a0c76aee2.1346352124.git.jcody@redhat.com> Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 1/7] block: correctly set the keep_read_only flag List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jeff Cody Cc: supriyak@linux.vnet.ibm.com, pbonzini@redhat.com, eblake@redhat.com, qemu-devel@nongnu.org, stefanha@gmail.com Am 30.08.2012 20:47, schrieb Jeff Cody: > I believe the bs->keep_read_only flag is supposed to reflect > the initial open state of the device. If the device is initially > opened R/O, then commit operations, or reopen operations changing > to R/W, are prohibited. > > Currently, the keep_read_only flag is only accurate for the active > layer, and its backing file. Subsequent images end up always having > the keep_read_only flag set. > > For instance, what happens now: > > [ base ] kro = 1, ro = 1 > | > v > [ snap-1 ] kro = 1, ro = 1 > | > v > [ snap-2 ] kro = 0, ro = 1 > | > v > [ active ] kro = 0, ro = 0 > > What we want: > > [ base ] kro = 0, ro = 1 > | > v > [ snap-1 ] kro = 0, ro = 1 > | > v > [ snap-2 ] kro = 0, ro = 1 > | > v > [ active ] kro = 0, ro = 0 > > Signed-off-by: Jeff Cody > --- > block.c | 16 +++++++--------- > block.h | 1 + > 2 files changed, 8 insertions(+), 9 deletions(-) > > diff --git a/block.c b/block.c > index 470bdcc..e31b76f 100644 > --- a/block.c > +++ b/block.c > @@ -655,7 +655,7 @@ static int bdrv_open_common(BlockDriverState *bs, const char *filename, > * Clear flags that are internal to the block layer before opening the > * image. > */ > - open_flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING); > + open_flags &= ~(BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING | BDRV_O_ALLOW_RDWR); > > /* > * Snapshots should be writable. > @@ -664,8 +664,6 @@ static int bdrv_open_common(BlockDriverState *bs, const char *filename, > open_flags |= BDRV_O_RDWR; > } > > - bs->keep_read_only = bs->read_only = !(open_flags & BDRV_O_RDWR); > - > /* Open the image, either directly or using a protocol */ > if (drv->bdrv_file_open) { > ret = drv->bdrv_file_open(bs, filename, open_flags); > @@ -804,6 +802,12 @@ int bdrv_open(BlockDriverState *bs, const char *filename, int flags, > goto unlink_and_fail; > } > > + if (flags & BDRV_O_RDWR) { > + flags |= BDRV_O_ALLOW_RDWR; > + } > + > + bs->keep_read_only = !(flags & BDRV_O_ALLOW_RDWR); Do we still need bs->keep_read_only or is it duplicated in bs->open_flags now? We can convert all users in a follow-up patch. Kevin