[PATCH v3 5/7] libsas: add a new workqueue to run probe/destruct discovery event

From: Yijing Wang
Date: Mon Jul 10 2017 - 03:03:07 EST


Sometimes, we want sync libsas probe or destruct in sas discovery work,
like when libsas revalidate domain. We need to split probe and destruct
work from the scsi host workqueue.

Signed-off-by: Yijing Wang <wangyijing@xxxxxxxxxx>
CC: John Garry <john.garry@xxxxxxxxxx>
CC: Johannes Thumshirn <jthumshirn@xxxxxxx>
CC: Ewan Milne <emilne@xxxxxxxxxx>
CC: Christoph Hellwig <hch@xxxxxx>
CC: Tomas Henzl <thenzl@xxxxxxxxxx>
CC: Dan Williams <dan.j.williams@xxxxxxxxx>
---
drivers/scsi/libsas/sas_discover.c | 13 ++++++++++++-
drivers/scsi/libsas/sas_init.c | 8 ++++++++
include/scsi/libsas.h | 1 +
3 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/libsas/sas_discover.c b/drivers/scsi/libsas/sas_discover.c
index 5d4a3a8..a25d648 100644
--- a/drivers/scsi/libsas/sas_discover.c
+++ b/drivers/scsi/libsas/sas_discover.c
@@ -559,7 +559,18 @@ static void sas_chain_work(struct sas_ha_struct *ha, struct sas_work *sw)
* not racing against draining
*/
sas_port_get(port);
- ret = scsi_queue_work(ha->core.shost, &sw->work);
+ /*
+ * discovery event probe and destruct would be called in other
+ * discovery event like discover domain and revalidate domain
+ * events, in some cases, we need to sync execute probe and destruct
+ * events, so run probe and destruct discover events except in a new
+ * workqueue.
+ */
+ if (ev->type == DISCE_PROBE || ev->type == DISCE_DESTRUCT)
+ ret = queue_work(ha->disc_q, &sw->work);
+ else
+ ret = scsi_queue_work(ha->core.shost, &sw->work);
+
if (ret != 1)
sas_port_put(port);
}
diff --git a/drivers/scsi/libsas/sas_init.c b/drivers/scsi/libsas/sas_init.c
index 2f3b736..df1d78b 100644
--- a/drivers/scsi/libsas/sas_init.c
+++ b/drivers/scsi/libsas/sas_init.c
@@ -152,6 +152,13 @@ int sas_register_ha(struct sas_ha_struct *sas_ha)
if (!sas_ha->event_q)
goto Undo_ports;

+ snprintf(name, 64, "%s_disc_q", dev_name(sas_ha->dev));
+ sas_ha->disc_q = create_singlethread_workqueue(name);
+ if(!sas_ha->disc_q) {
+ destroy_workqueue(sas_ha->event_q);
+ goto Undo_ports;
+ }
+
INIT_LIST_HEAD(&sas_ha->eh_done_q);
INIT_LIST_HEAD(&sas_ha->eh_ata_q);

@@ -187,6 +194,7 @@ int sas_unregister_ha(struct sas_ha_struct *sas_ha)
__sas_drain_work(sas_ha);
mutex_unlock(&sas_ha->drain_mutex);
destroy_workqueue(sas_ha->event_q);
+ destroy_workqueue(sas_ha->disc_q);

return 0;
}
diff --git a/include/scsi/libsas.h b/include/scsi/libsas.h
index c2ef05e..4bcb9fe 100644
--- a/include/scsi/libsas.h
+++ b/include/scsi/libsas.h
@@ -406,6 +406,7 @@ struct sas_ha_struct {
struct device *dev; /* should be set */
struct module *lldd_module; /* should be set */
struct workqueue_struct *event_q;
+ struct workqueue_struct *disc_q;

u8 *sas_addr; /* must be set */
u8 hashed_sas_addr[HASHED_SAS_ADDR_SIZE];
--
2.5.0