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

Johannes Thumshirn
2017-06-14T09:18:53Z

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);

--
Johannes Thumshirn Storage
jthumshirn@suse.de +49 911 74053 689
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
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