From: Webb Scales <web...@hp.com>
There is a possibility of deadlock if we use the system work queue
for command resubmission since something in the queue may be depending
on the I/O that gets resubmitted, and the resubmitted I/O will be
behind the thing that depends on it in the queue. Using a driver
specific, per-controller work queue avoids this.
Reviewed-by: Scott Teel <scott.t...@pmcs.com>
Signed-off-by: Webb Scales <web...@hp.com>
Signed-off-by: Don Brace <don.br...@pmcs.com>
---
drivers/scsi/hpsa.c | 16 +++++++++++++---
drivers/scsi/hpsa.h | 1 +
2 files changed, 14 insertions(+), 3 deletions(-)
diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c
index c1166a5..dcacb29 100644
--- a/drivers/scsi/hpsa.c
+++ b/drivers/scsi/hpsa.c
@@ -1651,7 +1651,7 @@ static void process_ioaccel2_completion(struct ctlr_info
*h,
retry_cmd:
INIT_WORK(&c->work, hpsa_command_resubmit_worker);
- schedule_work_on(raw_smp_processor_id(), &c->work);
+ queue_work_on(raw_smp_processor_id(), h->resubmit_wq, &c->work);
}
static void complete_scsi_command(struct CommandList *cp)
@@ -1722,7 +1722,8 @@ static void complete_scsi_command(struct CommandList *cp)
if (ei->CommandStatus == CMD_IOACCEL_DISABLED)
dev->offload_enabled = 0;
INIT_WORK(&cp->work, hpsa_command_resubmit_worker);
- schedule_work_on(raw_smp_processor_id(), &cp->work);
+ queue_work_on(raw_smp_processor_id(),
+ h->resubmit_wq, &cp->work);
return;
}
}
@@ -6418,6 +6419,7 @@ static void fail_all_outstanding_cmds(struct ctlr_info *h)
int i;
struct CommandList *c = NULL;
+ flush_workqueue(h->resubmit_wq); /* ensure all cmds are fully built */
for (i = 0; i < h->nr_cmds; i++) {
if (!test_bit(i & (BITS_PER_LONG - 1),
h->cmd_pool_bits + (i / BITS_PER_LONG)))
@@ -6653,6 +6655,12 @@ reinit_after_soft_reset:
spin_lock_init(&h->scan_lock);
spin_lock_init(&h->passthru_count_lock);
+ h->resubmit_wq = alloc_workqueue("hpsa", WQ_MEM_RECLAIM, 0);
+ if (!h->resubmit_wq) {
+ dev_err(&h->pdev->dev, "Failed to allocate work queue\n");
+ rc = -ENOMEM;
+ goto clean1;
+ }
/* Allocate and clear per-cpu variable lockup_detected */
h->lockup_detected = alloc_percpu(u32);
if (!h->lockup_detected) {
@@ -6785,6 +6793,8 @@ clean2_and_free_irqs:
hpsa_free_irqs(h);
clean2:
clean1:
+ if (h->resubmit_wq)
+ destroy_workqueue(h->resubmit_wq);
if (h->lockup_detected)
free_percpu(h->lockup_detected);
kfree(h);
@@ -6860,9 +6870,9 @@ static void hpsa_remove_one(struct pci_dev *pdev)
h->remove_in_progress = 1;
cancel_delayed_work(&h->monitor_ctlr_work);
spin_unlock_irqrestore(&h->lock, flags);
-
hpsa_unregister_scsi(h); /* unhook from SCSI subsystem */
hpsa_shutdown(pdev);
+ destroy_workqueue(h->resubmit_wq);
iounmap(h->vaddr);
iounmap(h->transtable);
iounmap(h->cfgtable);
diff --git a/drivers/scsi/hpsa.h b/drivers/scsi/hpsa.h
index 06a3e81..a0f4268 100644
--- a/drivers/scsi/hpsa.h
+++ b/drivers/scsi/hpsa.h
@@ -236,6 +236,7 @@ struct ctlr_info {
struct list_head offline_device_list;
int acciopath_status;
int raid_offload_debug;
+ struct workqueue_struct *resubmit_wq;
};
struct offline_device_entry {
--
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