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 <kwolf@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
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;
}