From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50804) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WLEHI-0006qJ-J1 for qemu-devel@nongnu.org; Wed, 05 Mar 2014 11:02:48 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WLEH9-0006WN-VN for qemu-devel@nongnu.org; Wed, 05 Mar 2014 11:02:40 -0500 Received: from mx.ipv6.kamp.de ([2a02:248:0:51::16]:35803 helo=mx01.kamp.de) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WLEH9-0006WB-L7 for qemu-devel@nongnu.org; Wed, 05 Mar 2014 11:02:31 -0500 Message-ID: <53174A93.4080006@kamp.de> Date: Wed, 05 Mar 2014 17:02:27 +0100 From: Peter Lieven MIME-Version: 1.0 References: <1394031649-31915-1-git-send-email-kwolf@redhat.com> <1394031649-31915-2-git-send-email-kwolf@redhat.com> In-Reply-To: <1394031649-31915-2-git-send-email-kwolf@redhat.com> Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 1/2] iscsi: Use bs->sg for everything else than disks List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Kevin Wolf , qemu-devel@nongnu.org Cc: pbonzini@redhat.com Am 05.03.2014 16:00, schrieb Kevin Wolf: > The current iscsi block driver code makes the rather arbitrary decision > that TYPE_MEDIUM_CHANGER and TYPE_TAPE devices have bs->sg = 1 and all > other device types are disks. > > Instead of this, check for TYPE_DISK to expose the disk interface and > make everything else bs->sg = 1. In particular, this includes devices > with TYPE_STORAGE_ARRAY, which is what LUN 0 of an iscsi target is. > (See https://bugzilla.redhat.com/show_bug.cgi?id=1067784 for the exact > scenario.) > > Signed-off-by: Kevin Wolf > --- > block/iscsi.c | 9 ++++----- > 1 file changed, 4 insertions(+), 5 deletions(-) > > diff --git a/block/iscsi.c b/block/iscsi.c > index 0a15f53..b490e98 100644 > --- a/block/iscsi.c > +++ b/block/iscsi.c > @@ -1231,12 +1231,11 @@ static int iscsi_open(BlockDriverState *bs, QDict *options, int flags, > bs->total_sectors = sector_lun2qemu(iscsilun->num_blocks, iscsilun); > bs->request_alignment = iscsilun->block_size; > > - /* Medium changer or tape. We dont have any emulation for this so this must > - * be sg ioctl compatible. We force it to be sg, otherwise qemu will try > - * to read from the device to guess the image format. > + /* We don't have any emulation for devices other than disks and CD-ROMs, so > + * this must be sg ioctl compatible. We force it to be sg, otherwise qemu > + * will try to read from the device to guess the image format. > */ > - if (iscsilun->type == TYPE_MEDIUM_CHANGER || > - iscsilun->type == TYPE_TAPE) { > + if (iscsilun->type != TYPE_DISK && iscsilun->type != TYPE_ROM) { > bs->sg = 1; > } > We have ioctl support in the iscsi block driver only for Linux. Is this a problem? Peter