On 01/09/2018 05:09 AM, Jason Yan wrote:
> Hannes,
>
> On 2018/1/8 20:04, Hannes Reinecke wrote:
>> The abort handler might be racing with command completion, so the
>> task might already be NULL by the time the abort handler is called.
>>
>> Signed-off-by: Hannes Reinecke <hare@xxxxxxxx>
>> ---
>> drivers/scsi/libsas/sas_scsi_host.c | 22 +++++++++++++++++++---
>> 1 file changed, 19 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/scsi/libsas/sas_scsi_host.c
>> b/drivers/scsi/libsas/sas_scsi_host.c
>> index 58476b7..08203fb 100644
>> --- a/drivers/scsi/libsas/sas_scsi_host.c
>> +++ b/drivers/scsi/libsas/sas_scsi_host.c
>> @@ -486,18 +486,34 @@ static int sas_queue_reset(struct domain_device
>> *dev, int reset_type,
>>
>> int sas_eh_abort_handler(struct scsi_cmnd *cmd)
>> {
>> - int res;
>> - struct sas_task *task = TO_SAS_TASK(cmd);
>> + int res = TMF_RESP_FUNC_COMPLETE;
>> + struct sas_task *task;
>> struct Scsi_Host *host = cmd->device->host;
>> struct sas_internal *i = to_sas_internal(host->transportt);
>> + struct domain_device *dev = cmd_to_domain_dev(cmd);
>> + struct sas_ha_struct *ha = dev->port->ha;
>> + unsigned long flags;
>>
>> if (!i->dft->lldd_abort_task)
>> return FAILED;
>>
>> - res = i->dft->lldd_abort_task(task);
>> + /* Avoid sas_scsi_task_done() interfering */
>> + spin_lock_irqsave(&dev->done_lock, flags);
>> + task = TO_SAS_TASK(cmd);
>> + if (test_bit(SAS_HA_FROZEN, &ha->state)) {
>> + res = TMF_RESP_FUNC_FAILED;
>> + task = NULL;
>> + } else
>> + ASSIGN_SAS_TASK(cmd, NULL);
>> + spin_unlock_irqrestore(&dev->done_lock, flags);
>> + if (task)
>> + res = i->dft->lldd_abort_task(task);
>> if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE)
>> return SUCCESS;
>>
>> + spin_lock_irqsave(&dev->done_lock, flags);
>> + ASSIGN_SAS_TASK(cmd, task);
>> + spin_unlock_irqrestore(&dev->done_lock, flags);
>
> Why do you assign task back? As I remember, when this cmd dispatch
> again, we will create a new task and assign to it again. So should we
> end this task here?
>
We only will create a new task if we decide to retry the command.
But if we return FAILED here the command is not retried but rather the
SCSI EH is invoked.
Cheers,
Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
hare@xxxxxxxx +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton
HRB 21284 (AG Nürnberg)
