[SCSI] libata, libsas: introduce sched_eh and end_eh port ops

When managing shost->host_eh_scheduled libata assumes that there is a
1:1 shost-to-ata_port relationship.  libsas creates a 1:N relationship
so it needs to manage host_eh_scheduled cumulatively at the host level.
The sched_eh and end_eh port port ops allow libsas to track when domain
devices enter/leave the "eh-pending" state under ha->lock (previously
named ha->state_lock, but it is no longer just a lock for ha->state
changes).

Since host_eh_scheduled indicates eh without backing commands pinning
the device it can be deallocated at any time.  Move the taking of the
domain_device reference under the port_lock to guarantee that the
ata_port stays around for the duration of eh.

Reviewed-by: Jacek Danecki <jacek.danecki@intel.com>
Acked-by: Jeff Garzik <jgarzik@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
This commit is contained in:
Dan Williams
2012-06-21 23:25:27 -07:00
committed by James Bottomley
parent 3b661a92e8
commit e4a9c3732c
10 changed files with 136 additions and 39 deletions

View File

@ -667,16 +667,20 @@ static void sas_eh_handle_sas_errors(struct Scsi_Host *shost, struct list_head *
goto out;
}
void sas_scsi_recover_host(struct Scsi_Host *shost)
{
struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
unsigned long flags;
LIST_HEAD(eh_work_q);
int tries = 0;
bool retry;
spin_lock_irqsave(shost->host_lock, flags);
retry:
tries++;
retry = true;
spin_lock_irq(shost->host_lock);
list_splice_init(&shost->eh_cmd_q, &eh_work_q);
shost->host_eh_scheduled = 0;
spin_unlock_irqrestore(shost->host_lock, flags);
spin_unlock_irq(shost->host_lock);
SAS_DPRINTK("Enter %s busy: %d failed: %d\n",
__func__, shost->host_busy, shost->host_failed);
@ -710,8 +714,19 @@ out:
scsi_eh_flush_done_q(&ha->eh_done_q);
SAS_DPRINTK("--- Exit %s: busy: %d failed: %d\n",
__func__, shost->host_busy, shost->host_failed);
/* check if any new eh work was scheduled during the last run */
spin_lock_irq(&ha->lock);
if (ha->eh_active == 0) {
shost->host_eh_scheduled = 0;
retry = false;
}
spin_unlock_irq(&ha->lock);
if (retry)
goto retry;
SAS_DPRINTK("--- Exit %s: busy: %d failed: %d tries: %d\n",
__func__, shost->host_busy, shost->host_failed, tries);
}
enum blk_eh_timer_return sas_scsi_timed_out(struct scsi_cmnd *cmd)