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[SCSI] libsas: add mutex for SMP task execution

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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>
This commit is contained in:
Jeff Skirvin 2011-11-16 09:44:13 +00:00 committed by James Bottomley
parent 1f4fe89c9c
commit 89d3cf6ac3
3 changed files with 34 additions and 28 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

1
drivers/scsi/libsas/sas_discover.c
View file

@ -43,6 +43,7 @@ void sas_init_dev(struct domain_device *dev)
case EDGE_DEV:
case FANOUT_DEV:
INIT_LIST_HEAD(&dev->ex_dev.children);
mutex_init(&dev->ex_dev.cmd_mutex);
break;
case SATA_DEV:
case SATA_PM:

23
drivers/scsi/libsas/sas_expander.c
View file

@ -72,11 +72,13 @@ static int smp_execute_task(struct domain_device *dev, void *req, int req_size,
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 @@ static int smp_execute_task(struct domain_device *dev, void *req, int req_size,
if (res) {
del_timer(&task->timer);
SAS_DPRINTK("executing SMP task failed:%d\n", res);
goto ex_err;
break;
}
wait_for_completion(&task->completion);
@ -104,20 +106,22 @@ static int smp_execute_task(struct domain_device *dev, void *req, int req_size,
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 &&
}
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 &&
}
if (task->task_status.resp == SAS_TASK_COMPLETE &&
task->task_status.stat == SAS_DATA_OVERRUN) {
res = -EMSGSIZE;
break;
@ -131,11 +135,10 @@ static int smp_execute_task(struct domain_device *dev, void *req, int req_size,
task = NULL;
}
}
ex_err:
mutex_unlock(&dev->ex_dev.cmd_mutex);
BUG_ON(retry == 3 && task != NULL);
if (task != NULL) {
sas_free_task(task);
}
return res;
}

2
include/scsi/libsas.h
View file

@ -153,6 +153,8 @@ struct expander_device {
struct ex_phy *ex_phy;
struct sas_port *parent_port;
struct mutex cmd_mutex;
};
/* ---------- SATA device ---------- */