From: Jurij Smakov <jurij@xxxxxxxxx>
Date: Wed, 10 May 2006 00:15:08 -0700 (PDT)
> --- a/drivers/scsi/esp.c
> +++ b/drivers/scsi/esp.c
> @@ -2068,14 +2068,12 @@ static int esp_reset(struct scsi_cmnd *S
> {
> struct esp *esp = (struct esp *) SCptr->device->host->hostdata;
>
> + spin_lock_irq(esp->ehost->host_lock);
> (void) esp_do_resetbus(esp);
> -
> spin_unlock_irq(esp->ehost->host_lock);
>
> wait_event(esp->reset_queue, (esp->resetting_bus == 0));
>
> - spin_lock_irq(esp->ehost->host_lock);
> -
> return SUCCESS;
> }
>
> I have not nearly enough knowledge to tell whether that is correct, but
> the fact that in the previous version the function is left with the lock
> held and in the new one - without it, struck me as suspicious.
I don't know where you got that weird patch from, the current function
looks like this:
static int esp_reset(struct scsi_cmnd *SCptr)
{
struct esp *esp = (struct esp *) SCptr->device->host->hostdata;
spin_lock_irq(esp->ehost->host_lock);
(void) esp_do_resetbus(esp);
spin_unlock_irq(esp->ehost->host_lock);
wait_event(esp->reset_queue, (esp->resetting_bus == 0));
return SUCCESS;
}
The caller from the EH subsystem in drivers/scsi/scsi_error.c does not
hold the host lock, so we need to acquire it around the critical
section, which in this case is esp_do_resetbus(), then we drop
the lock in order to wait on the reset queue which is a blocking
operation and thus cannot hold any spinlocks.
-
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