diff mbox

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

Message ID 1499670369-44143-6-git-send-email-wangyijing@huawei.com (mailing list archive)
State Changes Requested, archived
Headers show

Commit Message

Yijing Wang July 10, 2017, 7:06 a.m. UTC
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@huawei.com>
CC: John Garry <john.garry@huawei.com>
CC: Johannes Thumshirn <jthumshirn@suse.de>
CC: Ewan Milne <emilne@redhat.com>
CC: Christoph Hellwig <hch@lst.de>
CC: Tomas Henzl <thenzl@redhat.com>
CC: Dan Williams <dan.j.williams@intel.com>
---
 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(-)

Comments

John Garry July 12, 2017, 4:50 p.m. UTC | #1
On 10/07/2017 08:06, Yijing Wang wrote:
> 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@huawei.com>
> CC: John Garry <john.garry@huawei.com>
> CC: Johannes Thumshirn <jthumshirn@suse.de>
> CC: Ewan Milne <emilne@redhat.com>
> CC: Christoph Hellwig <hch@lst.de>
> CC: Tomas Henzl <thenzl@redhat.com>
> CC: Dan Williams <dan.j.williams@intel.com>
> ---
>  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.

Can we just use ha->disc_q for all discovery events for simplicity? 
Would this solve the disco mutex you try to solve in patch 7/7?

> +	 */
> +	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)

Uhh, we are mixing bool and int here... but we're forced to by 
scsi_queue_work()

>  		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];
>
Yijing Wang July 13, 2017, 2:36 a.m. UTC | #2
在 2017/7/13 0:50, John Garry 写道:
> On 10/07/2017 08:06, Yijing Wang wrote:
>> 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@huawei.com>
>> CC: John Garry <john.garry@huawei.com>
>> CC: Johannes Thumshirn <jthumshirn@suse.de>
>> CC: Ewan Milne <emilne@redhat.com>
>> CC: Christoph Hellwig <hch@lst.de>
>> CC: Tomas Henzl <thenzl@redhat.com>
>> CC: Dan Williams <dan.j.williams@intel.com>
>> ---
>>  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.
> 
> Can we just use ha->disc_q for all discovery events for simplicity? Would this solve the disco mutex you try to solve in patch 7/7?

No, since we could queue sas discovery probe/destruct event in sas discovery work(like sas_revalidate_domain)

sas_revalidate_domain
	sas_ex_revalidate_domain
		sas_rediscover
			sas_rediscover_dev
				sas_unregister_devs_sas_addr
					sas_unregister_dev
						sas_discover_event(dev->port, DISCE_DESTRUCT)
				sas_discover_new
					sas_ex_discover_devices
						sas_ex_discover_dev
							sas_ex_discover_end_dev
								sas_discover_end_dev
									sas_discover_event(dev->port, DISCE_PROBE)

So we could not sync probe or destruct sas discovery event in sas_revalidate_domain if they are queued in a same workqueue,
or it would block for ever.


> 
>> +     */
>> +    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)
> 
> Uhh, we are mixing bool and int here... but we're forced to by scsi_queue_work()

Eagle eye :), I could check the return value separately.

Thanks!
Yijing.


> 
>>          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];
>>
> 
> 
> 
> .
>
Hannes Reinecke July 14, 2017, 6:52 a.m. UTC | #3
On 07/10/2017 09:06 AM, Yijing Wang wrote:
> 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@huawei.com>
> CC: John Garry <john.garry@huawei.com>
> CC: Johannes Thumshirn <jthumshirn@suse.de>
> CC: Ewan Milne <emilne@redhat.com>
> CC: Christoph Hellwig <hch@lst.de>
> CC: Tomas Henzl <thenzl@redhat.com>
> CC: Dan Williams <dan.j.williams@intel.com>
> ---
>  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(-)
> 
Reviewed-by: Hannes Reinecke <hare@suse.com>

Cheers,

Hannes
diff mbox

Patch

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];