Re: [PATCH V5 1/5] virtio-scsi: redo allocation of target data

[James Bottomley <James.Bottomley@HansenPartnership.com>]

On Tue, 2013-03-19 at 12:45 +0100, Paolo Bonzini wrote:
> Il 19/03/2013 12:32, James Bottomley ha scritto:
> > On Tue, 2013-03-19 at 17:57 +0800, Wanlong Gao wrote:
> >> From: Paolo Bonzini <pbonzini@redhat.com>
> >>
> >> virtio_scsi_target_state is now empty.  We will find new uses for it in
> >> the next few patches, so this patch does not drop it completely.
> >> However, having dropped the sglist flexible array member, we can turn
> >> the tgt array-of-pointers into a simple array.  This simplifies the
> >> allocation.
> >>
> >> Even simpler would be to place the virtio_scsi_target_state structs in a
> >> flexible array member at the end of struct virtio_scsi.  But we do not
> >> do that, because we will place the virtqueues there in the next patches.
> > 
> > I'm really sorry, but I must have been asleep at the wheel when I let
> > code like this go in.  No modern driver should have fixed arrays for
> > target information.  The way this is supposed to work is that you have
> > entries in the host template for target_alloc and target_destroy.  You
> > hook into these and attach your struct virtio_scsi_target_state to
> > scsi_target->hostdata,
> 
> So that would be sc->device->sdev_target->hostdata.

No, unfortunate name, but it's used for something else (actually, I
think it *was* used by something else and is unused now).  The construct
is

scsi_target(sc->device)->hostdata

James