Re: [PATCH] scsi: Add SHT->unlocked_qcmd for host_lock less SHT->queuecommand() dispatch

["Nicholas A. Bellinger" <nab@linux-iscsi.org>]

On Wed, 2010-10-27 at 13:23 -0500, Mike Christie wrote:
> On 10/26/2010 07:32 PM, Nicholas A. Bellinger wrote:
> > diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
> > index fec47de..f5933dd 100644
> > --- a/drivers/scsi/iscsi_tcp.c
> > +++ b/drivers/scsi/iscsi_tcp.c
> > @@ -882,6 +882,7 @@ static struct scsi_host_template iscsi_sw_tcp_sht = {
> >   	.target_alloc		= iscsi_target_alloc,
> >   	.proc_name		= "iscsi_tcp",
> >   	.this_id		= -1,
> > +	.unlocked_qcmd		= 1,
> >   };
> >
> >   static struct iscsi_transport iscsi_sw_tcp_transport = {
> > diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
> > index 633e090..7e4134e 100644
> > --- a/drivers/scsi/libiscsi.c
> > +++ b/drivers/scsi/libiscsi.c
> > @@ -1615,7 +1615,6 @@ int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
> >
> >   	host = sc->device->host;
> >   	ihost = shost_priv(host);
> > -	spin_unlock(host->host_lock);
> >
> >   	cls_session = starget_to_session(scsi_target(sc->device));
> >   	session = cls_session->dd_data;
> > @@ -1706,7 +1705,6 @@ int iscsi_queuecommand(struct scsi_cmnd *sc, void (*done)(struct scsi_cmnd *))
> >
> >   	session->queued_cmdsn++;
> >   	spin_unlock(&session->lock);
> > -	spin_lock(host->host_lock);
> >   	return 0;
> >
> >   prepd_reject:
> > @@ -1716,7 +1714,6 @@ reject:
> >   	spin_unlock(&session->lock);
> >   	ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
> >   			  sc->cmnd[0], reason);
> > -	spin_lock(host->host_lock);
> >   	return SCSI_MLQUEUE_TARGET_BUSY;
> >
> >   prepd_fault:
> > @@ -1733,7 +1730,6 @@ fault:
> >   		scsi_in(sc)->resid = scsi_in(sc)->length;
> >   	}
> >   	done(sc);
> > -	spin_lock(host->host_lock);
> >   	return 0;
> >   }
> >   EXPORT_SYMBOL_GPL(iscsi_queuecommand);
> 
> 
> Hey,
> 
> iscsi_tcp, drivers/infiniband/ulp/iser/ib_iser, drivers/scsi/cxgb3i, 
> drivers/scsi/bnx2i, and drivers/scsi/be2iscsi use libiscsi's 
> iscsi_queuecommand function, so they should all use the same setting 
> unlocked_qcmd=1.


Hmmm, that is what I was thinking too.. Thanks for confirming this.
Respinning again to include this LLDs w/ the new
SHT->queuecommad_unlocked() usage.

Thanks Mike!

--nab