[SCSI] libsas: add mutex for SMP task execution
SAS does not tag SMP requests, and at least one lldd (isci) does not permit
more than one in-flight request at a time.
[jejb: fix sas_init_dev tab issues while we're at it]
Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.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_expander.c b/drivers/scsi/libsas/sas_expander.c
index d3c1a29..7c59f97 100644
--- a/drivers/scsi/libsas/sas_expander.c
+++ b/drivers/scsi/libsas/sas_expander.c
@@ -72,11 +72,13 @@
struct sas_internal *i =
to_sas_internal(dev->port->ha->core.shost->transportt);
+ mutex_lock(&dev->ex_dev.cmd_mutex);
for (retry = 0; retry < 3; retry++) {
task = sas_alloc_task(GFP_KERNEL);
- if (!task)
- return -ENOMEM;
-
+ if (!task) {
+ res = -ENOMEM;
+ break;
+ }
task->dev = dev;
task->task_proto = dev->tproto;
sg_init_one(&task->smp_task.smp_req, req, req_size);
@@ -94,7 +96,7 @@
if (res) {
del_timer(&task->timer);
SAS_DPRINTK("executing SMP task failed:%d\n", res);
- goto ex_err;
+ break;
}
wait_for_completion(&task->completion);
@@ -104,21 +106,23 @@
i->dft->lldd_abort_task(task);
if (!(task->task_state_flags & SAS_TASK_STATE_DONE)) {
SAS_DPRINTK("SMP task aborted and not done\n");
- goto ex_err;
+ break;
}
}
if (task->task_status.resp == SAS_TASK_COMPLETE &&
task->task_status.stat == SAM_STAT_GOOD) {
res = 0;
break;
- } if (task->task_status.resp == SAS_TASK_COMPLETE &&
- task->task_status.stat == SAS_DATA_UNDERRUN) {
+ }
+ if (task->task_status.resp == SAS_TASK_COMPLETE &&
+ task->task_status.stat == SAS_DATA_UNDERRUN) {
/* no error, but return the number of bytes of
* underrun */
res = task->task_status.residual;
break;
- } if (task->task_status.resp == SAS_TASK_COMPLETE &&
- task->task_status.stat == SAS_DATA_OVERRUN) {
+ }
+ if (task->task_status.resp == SAS_TASK_COMPLETE &&
+ task->task_status.stat == SAS_DATA_OVERRUN) {
res = -EMSGSIZE;
break;
} else {
@@ -131,11 +135,10 @@
task = NULL;
}
}
-ex_err:
+ mutex_unlock(&dev->ex_dev.cmd_mutex);
+
BUG_ON(retry == 3 && task != NULL);
- if (task != NULL) {
- sas_free_task(task);
- }
+ sas_free_task(task);
return res;
}