[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>
diff --git a/drivers/scsi/libsas/sas_scsi_host.c b/drivers/scsi/libsas/sas_scsi_host.c
index f0b9b7b..a09da44 100644
--- a/drivers/scsi/libsas/sas_scsi_host.c
+++ b/drivers/scsi/libsas/sas_scsi_host.c
@@ -667,16 +667,20 @@
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 @@
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)