[SCSI] pm8001: simplify workqueue usage
pm8001 manages its own list of pending works and cancel them on device
free. It is unnecessarily complex and has a race condition - the
works are canceled but not synced, so the work could still be running
during and after the data structures are freed.
This patch simplifies workqueue usage.
* A driver specific workqueue pm8001_wq is created to serve these
work items.
* To avoid confusion, the "queue" suffixes are dropped from work items
and functions.
* Delayed queueing was never used. pm8001_work now uses work_struct
instead.
* The driver no longer keeps track of pending works. All pm8001_works
are queued to pm8001_wq and the workqueue is flushed as necessary.
flush_scheduled_work() usage is removed during conversion.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Jack Wang <jack_wang@usish.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
diff --git a/drivers/scsi/pm8001/pm8001_init.c b/drivers/scsi/pm8001/pm8001_init.c
index b95285f3..002360d 100644
--- a/drivers/scsi/pm8001/pm8001_init.c
+++ b/drivers/scsi/pm8001/pm8001_init.c
@@ -51,6 +51,8 @@
LIST_HEAD(hba_list);
+struct workqueue_struct *pm8001_wq;
+
/**
* The main structure which LLDD must register for scsi core.
*/
@@ -134,7 +136,6 @@
static void pm8001_free(struct pm8001_hba_info *pm8001_ha)
{
int i;
- struct pm8001_wq *wq;
if (!pm8001_ha)
return;
@@ -150,8 +151,7 @@
PM8001_CHIP_DISP->chip_iounmap(pm8001_ha);
if (pm8001_ha->shost)
scsi_host_put(pm8001_ha->shost);
- list_for_each_entry(wq, &pm8001_ha->wq_list, entry)
- cancel_delayed_work(&wq->work_q);
+ flush_workqueue(pm8001_wq);
kfree(pm8001_ha->tags);
kfree(pm8001_ha);
}
@@ -381,7 +381,6 @@
pm8001_ha->sas = sha;
pm8001_ha->shost = shost;
pm8001_ha->id = pm8001_id++;
- INIT_LIST_HEAD(&pm8001_ha->wq_list);
pm8001_ha->logging_level = 0x01;
sprintf(pm8001_ha->name, "%s%d", DRV_NAME, pm8001_ha->id);
#ifdef PM8001_USE_TASKLET
@@ -758,7 +757,7 @@
int i , pos;
u32 device_state;
pm8001_ha = sha->lldd_ha;
- flush_scheduled_work();
+ flush_workqueue(pm8001_wq);
scsi_block_requests(pm8001_ha->shost);
pos = pci_find_capability(pdev, PCI_CAP_ID_PM);
if (pos == 0) {
@@ -870,17 +869,26 @@
*/
static int __init pm8001_init(void)
{
- int rc;
+ int rc = -ENOMEM;
+
+ pm8001_wq = alloc_workqueue("pm8001", 0, 0);
+ if (!pm8001_wq)
+ goto err;
+
pm8001_id = 0;
pm8001_stt = sas_domain_attach_transport(&pm8001_transport_ops);
if (!pm8001_stt)
- return -ENOMEM;
+ goto err_wq;
rc = pci_register_driver(&pm8001_pci_driver);
if (rc)
- goto err_out;
+ goto err_tp;
return 0;
-err_out:
+
+err_tp:
sas_release_transport(pm8001_stt);
+err_wq:
+ destroy_workqueue(pm8001_wq);
+err:
return rc;
}
@@ -888,6 +896,7 @@
{
pci_unregister_driver(&pm8001_pci_driver);
sas_release_transport(pm8001_stt);
+ destroy_workqueue(pm8001_wq);
}
module_init(pm8001_init);