Am 05.03.2014 um 17:02 hat Peter Lieven geschrieben: > 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 <kw...@redhat.com> > > --- > > 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?
Should be okay. It will cause the requests to fail, obviously (bdrv_ioctl returns -ENOTSUP, and bdrv_aio_ioctl returns NULL), but callers seem to cope with it and if we don't know how to handle the request, that's the right thing to do. Kevin
