[v2,1/2] libsas: Don't process sas events in static works

Commit Message

Johannes Thumshirn June 14, 2017, 9:18 a.m. UTC

On 06/14/2017 11:04 AM, wangyijing wrote:
>>>  static void notify_ha_event(struct sas_ha_struct *sas_ha, enum ha_event event)
>>>  {
>>> +	struct sas_ha_event *ev;
>>> +
>>>  	BUG_ON(event >= HA_NUM_EVENTS);
>>>  
>>> -	sas_queue_event(event, &sas_ha->pending,
>>> -			&sas_ha->ha_events[event].work, sas_ha);
>>> +	ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
>>> +	if (!ev)
>>> +		return;
>> GFP_ATOMIC allocations can fail and then no events will be queued *and* we
>> don't report the error back to the caller.
>>
> 
> Yes, it's really a problem, but I don't find a better solution, do you have some suggestion ?

Something like this?

Comments

Yijing Wang June 14, 2017, 9:28 a.m. UTC | #1

在 2017/6/14 17:18, Johannes Thumshirn 写道:
> On 06/14/2017 11:04 AM, wangyijing wrote:
>>>>  static void notify_ha_event(struct sas_ha_struct *sas_ha, enum ha_event event)
>>>>  {
>>>> +	struct sas_ha_event *ev;
>>>> +
>>>>  	BUG_ON(event >= HA_NUM_EVENTS);
>>>>  
>>>> -	sas_queue_event(event, &sas_ha->pending,
>>>> -			&sas_ha->ha_events[event].work, sas_ha);
>>>> +	ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
>>>> +	if (!ev)
>>>> +		return;
>>> GFP_ATOMIC allocations can fail and then no events will be queued *and* we
>>> don't report the error back to the caller.
>>>
>>
>> Yes, it's really a problem, but I don't find a better solution, do you have some suggestion ?
> 
> Something like this?
> 
> diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c
> b/drivers/scsi/hisi_sas/hisi_sas_main.c
> index d622db502ec9..27cd7307d308 100644
> --- a/drivers/scsi/hisi_sas/hisi_sas_main.c
> +++ b/drivers/scsi/hisi_sas/hisi_sas_main.c
> @@ -894,7 +894,11 @@ static int hisi_sas_controller_reset(struct
> hisi_hba *hisi_hba)
>                 hisi_sas_release_tasks(hisi_hba);
>                 spin_unlock_irqrestore(&hisi_hba->lock, flags);
> 
> -               sas_ha->notify_ha_event(sas_ha, HAE_RESET);
> +               rc = sas_ha->notify_ha_event(sas_ha, HAE_RESET);
> +               if (rc) {
> +                       dev_warn(dev, "failed to queue HA event (%d)\n",
> rc);
> +                       goto out;
> +               }
>                 dev_dbg(dev, "controller reset successful!\n");
>         } else
>                 return -1;
> diff --git a/drivers/scsi/libsas/sas_event.c
> b/drivers/scsi/libsas/sas_event.c
> index aadbd5314c5c..6c91fb31f891 100644
> --- a/drivers/scsi/libsas/sas_event.c
> +++ b/drivers/scsi/libsas/sas_event.c
> @@ -116,7 +116,7 @@ void sas_enable_revalidation(struct sas_ha_struct *ha)
>         mutex_unlock(&ha->disco_mutex);
>  }
> 
> -static void notify_ha_event(struct sas_ha_struct *sas_ha, enum ha_event
> event)
> +static int notify_ha_event(struct sas_ha_struct *sas_ha, enum ha_event
> event)
>  {
>         BUG_ON(event >= HA_NUM_EVENTS);
> 
> diff --git a/include/scsi/libsas.h b/include/scsi/libsas.h
> index dd0f72c95abe..5d9cd6d20855 100644
> --- a/include/scsi/libsas.h
> +++ b/include/scsi/libsas.h
> @@ -415,7 +415,7 @@ struct sas_ha_struct {
>                                 * their siblings when forming wide ports */
> 
>         /* LLDD calls these to notify the class of an event. */
> -       void (*notify_ha_event)(struct sas_ha_struct *, enum ha_event);
> +       int (*notify_ha_event)(struct sas_ha_struct *, enum ha_event);
>         void (*notify_port_event)(struct asd_sas_phy *, enum port_event);
>         void (*notify_phy_event)(struct asd_sas_phy *, enum phy_event);

This make sense, return a fail status and report it to the callers.


> 
>

Patch

diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c
b/drivers/scsi/hisi_sas/hisi_sas_main.c
index d622db502ec9..27cd7307d308 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_main.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_main.c
@@ -894,7 +894,11 @@  static int hisi_sas_controller_reset(struct
hisi_hba *hisi_hba)
                hisi_sas_release_tasks(hisi_hba);
                spin_unlock_irqrestore(&hisi_hba->lock, flags);

-               sas_ha->notify_ha_event(sas_ha, HAE_RESET);
+               rc = sas_ha->notify_ha_event(sas_ha, HAE_RESET);
+               if (rc) {
+                       dev_warn(dev, "failed to queue HA event (%d)\n",
rc);
+                       goto out;
+               }
                dev_dbg(dev, "controller reset successful!\n");
        } else
                return -1;
diff --git a/drivers/scsi/libsas/sas_event.c
b/drivers/scsi/libsas/sas_event.c
index aadbd5314c5c..6c91fb31f891 100644
--- a/drivers/scsi/libsas/sas_event.c
+++ b/drivers/scsi/libsas/sas_event.c
@@ -116,7 +116,7 @@  void sas_enable_revalidation(struct sas_ha_struct *ha)
        mutex_unlock(&ha->disco_mutex);
 }

-static void notify_ha_event(struct sas_ha_struct *sas_ha, enum ha_event
event)
+static int notify_ha_event(struct sas_ha_struct *sas_ha, enum ha_event
event)
 {
        BUG_ON(event >= HA_NUM_EVENTS);

diff --git a/include/scsi/libsas.h b/include/scsi/libsas.h
index dd0f72c95abe..5d9cd6d20855 100644
--- a/include/scsi/libsas.h
+++ b/include/scsi/libsas.h
@@ -415,7 +415,7 @@  struct sas_ha_struct {
                                * their siblings when forming wide ports */

        /* LLDD calls these to notify the class of an event. */
-       void (*notify_ha_event)(struct sas_ha_struct *, enum ha_event);
+       int (*notify_ha_event)(struct sas_ha_struct *, enum ha_event);
        void (*notify_port_event)(struct asd_sas_phy *, enum port_event);
        void (*notify_phy_event)(struct asd_sas_phy *, enum phy_event);