Re: [PATCH 2/2] cciss: Fix SCSI device reset handler

From: Andrew Morton
Date: Tue Jun 02 2009 - 13:51:38 EST


On Tue, 2 Jun 2009 14:50:11 +0200
Jens Axboe <jens.axboe@xxxxxxxxxx> wrote:

> On Fri, May 29 2009, Andrew Morton wrote:
> > On Wed, 27 May 2009 15:30:07 -0500
> > scameron@xxxxxxxxxxxxxxxxxxxxxxx wrote:
> >
> > > +static int wait_for_device_to_become_ready(ctlr_info_t *h,
> > > + unsigned char lunaddr[])
> > > +{
> > > + int rc;
> > > + int count = 0;
> > > + int waittime = HZ;
> > > + CommandList_struct *c;
> > > +
> > > + c = cmd_alloc(h, 1);
> > > + if (!c) {
> > > + printk(KERN_WARNING "cciss%d: out of memory in "
> > > + "wait_for_device_to_become_ready.\n", h->ctlr);
> > > + return IO_ERROR;
> > > + }
> > > +
> > > + /* Send test unit ready until device ready, or give up. */
> > > + while (count < 20) {
> > > +
> > > + /* Wait for a bit. do this first, because if we send
> > > + * the TUR right away, the reset will just abort it.
> > > + */
> > > + set_current_state(TASK_INTERRUPTIBLE);
> > > + schedule_timeout(waittime);
> >
> > That's schedule_timeout_interruptible().
> >
> > The problem with interruptible sleeps of this nature is that they are
> > no-ops if the calling process happens to have signal_pending(). I
> > suspect that this condition will break your driver.
> >
> > If so, switching to schedule_timeout_uninterruptible() will unbreak it.
>
> I added Stephens patch and your fixup.

My cciss-fix-scsi-device-reset-handler-fix.patch was a simple cleanup -
it uses schedule_timeout_interruptible().

I believe that this should be changed to
schedule_timeout_uninterruptible() for the above reasons, but the cciss
guys fell asleep on me.

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