On 9/18/2012 2:06 PM, James Bottomley wrote:

On Tue, 2012-09-18 at 09:54, Naresh Kumar Inna wrote:

quoted

Hi James,

Could you please consider merging version V4 of the driver patches, if
you think they are in good shape now?

Well, definitely not yet; you seem to have missed the memo on readq:

  CC [M]  drivers/scsi/cxgbi/cxgb4i/cxgb4i.o
drivers/scsi/csiostor/csio_hw.c: In function csio_hw_mc_read:
drivers/scsi/csiostor/csio_hw.c:194:3: error: implicit declaration of
function readq [-Werror=implicit-function-declaration]

It's only defined on platforms which can support an atomic 64 bit
operation (which is mostly not any 32 bit platforms) ... so this could
do with compile testing on those.

To see how to handle readq/writeq in the 32 bit case, see the uses in
fnic or qla2xxx

Thanks for reviewing. I will fix up readq/writeq, as well as other
32-bit compilation issues, if any.

You also have a couple of unnecessary version.h includes.

I will get rid of them.

Since you're a new driver, could you not do a correctly unlocked
queuecommand routine?  You'll find the way you've currently got it coded
(holding the host lock for the entire queuecommand routine) is very
performance detrimental.

Yes, I am aware of that. However, some of this code was written and
tested before the lock-less queuecommand came into existence. Going the
lock-less route would require me to test the driver thoroughly again. It
definitely is in my to-do list, but I would like to take that up after
the initial submission goes through. Would that be OK?

You have a lot of locking statements which aren't easy to audit by hand
because there are multiple unlocks.  Things like this:

csio_scan_finished(struct Scsi_Host *shost, unsigned long time)
{
	struct csio_lnode *ln = shost_priv(shost);
	int rv = 0;

	spin_lock_irq(shost->host_lock);
	if (!ln->hwp || csio_list_deleted(&ln->sm.sm_list)) {
		spin_unlock_irq(shost->host_lock);
		return 1;
	}

	rv = csio_scan_done(ln, jiffies, time, csio_max_scan_tmo * HZ,
			    csio_delta_scan_tmo * HZ);

	spin_unlock_irq(shost->host_lock);

	return rv;
}

Are better coded as

csio_scan_finished(struct Scsi_Host *shost, unsigned long time)
{
	struct csio_lnode *ln = shost_priv(shost);
	int rv = 1;

	spin_lock_irq(shost->host_lock);
	if (!ln->hwp || csio_list_deleted(&ln->sm.sm_list))
		goto out;

	rv = csio_scan_done(ln, jiffies, time, csio_max_scan_tmo * HZ,
			    csio_delta_scan_tmo * HZ);

 out:
	spin_unlock_irq(shost->host_lock);

	return rv;
}

It's shorter and the unlock clearly matches the lock.  You could even
invert the if logic and just make the csio_scan_done() conditional on it
avoiding the goto.

I will try to minimize the lock/unlock mismatch instances per your
suggestions, if not eliminate them altogether.

I'd also really like the people who understand FC to take a look over
this as well.

Sure.

Thanks,
Naresh.