From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51499) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fpTkH-0002w8-AH for qemu-devel@nongnu.org; Tue, 14 Aug 2018 03:28:06 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fpTkG-0007uW-CI for qemu-devel@nongnu.org; Tue, 14 Aug 2018 03:28:01 -0400 Date: Tue, 14 Aug 2018 08:27:49 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Message-ID: <20180814072749.GB5057@redhat.com> Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= References: <20180814072551.15465-1-famz@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20180814072551.15465-1-famz@redhat.com> Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH] luks: Allow share-rw=on List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Fam Zheng Cc: qemu-devel@nongnu.org, Kevin Wolf , Max Reitz , qemu-block@nongnu.org On Tue, Aug 14, 2018 at 03:25:51PM +0800, Fam Zheng wrote: > Format drivers such as qcow2 don't allow sharing the same image between > two QEMU instances in order to prevent image corruptions, because of > metadata cache. LUKS driver don't modify metadata except for when > creating image, so it is safe to relax the permission. This makes > share-rw=3Don property work on virtual devices. >=20 > Suggested-by: Daniel P. Berrang=C3=A9 > Signed-off-by: Fam Zheng > --- > block/crypto.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) >=20 > diff --git a/block/crypto.c b/block/crypto.c > index 146d81c90a..33ee01bebd 100644 > --- a/block/crypto.c > +++ b/block/crypto.c > @@ -627,7 +627,9 @@ BlockDriver bdrv_crypto_luks =3D { > .bdrv_probe =3D block_crypto_probe_luks, > .bdrv_open =3D block_crypto_open_luks, > .bdrv_close =3D block_crypto_close, > - .bdrv_child_perm =3D bdrv_format_default_perms, > + /* This driver doesn't modify LUKS metadata except when creating i= mage. > + * Allow share-rw=3Don as a special case. */ > + .bdrv_child_perm =3D bdrv_filter_default_perms, > .bdrv_co_create =3D block_crypto_co_create_luks, > .bdrv_co_create_opts =3D block_crypto_co_create_opts_luks, > .bdrv_co_truncate =3D block_crypto_co_truncate, Reviewed-by: Daniel P. Berrang=C3=A9 Regards, Daniel --=20 |: https://berrange.com -o- https://www.flickr.com/photos/dberran= ge :| |: https://libvirt.org -o- https://fstop138.berrange.c= om :| |: https://entangle-photo.org -o- https://www.instagram.com/dberran= ge :|