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

wangyijing
2017-06-14T09:28:34Z

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.

>
>