On 04/24/2013 04:48 PM, James Bottomley wrote:
> On Wed, 2013-04-24 at 13:32 +0200, Hannes Reinecke wrote:
>> scsi_send_eh_cmnd() is calling queuecommand() directly, so
>> it needs to check the return value here.
>> The only valid return codes for queuecommand() are 'busy'
>> states, so we need to wait for a bit to allow the LLDD
>> to recover.
>>
>> Based on an earlier patch from Wen Xiong.
>
> This looks good, only one minor nitpick:
>
>> Cc: Wen Xiong <wenxiong@xxxxxxxxxxxxxxxxxx>
>> Cc: Brian King <brking@xxxxxxxxxxxxxxxxxx>
>> Signed-off-by: Hannes Reinecke <hare@xxxxxxx>
>>
>> diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
>> index c1b05a8..1fc6da94 100644
>> --- a/drivers/scsi/scsi_error.c
>> +++ b/drivers/scsi/scsi_error.c
>> @@ -791,22 +791,32 @@ static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, unsigned char *cmnd,
>> struct scsi_device *sdev = scmd->device;
>> struct Scsi_Host *shost = sdev->host;
>> DECLARE_COMPLETION_ONSTACK(done);
>> - unsigned long timeleft;
>> + unsigned long timeleft = timeout;
>> struct scsi_eh_save ses;
>> + const int stall_for = min(HZ/10, 1);
>> int rtn;
>>
>> +retry:
>> scsi_eh_prep_cmnd(scmd, &ses, cmnd, cmnd_size, sense_bytes);
>> shost->eh_action = &done;
>>
>> scsi_log_send(scmd);
>> scmd->scsi_done = scsi_eh_done;
>> - shost->hostt->queuecommand(shost, scmd);
>> -
>> - timeleft = wait_for_completion_timeout(&done, timeout);
>> + rtn = shost->hostt->queuecommand(shost, scmd);
>> + if (rtn) {
>> + if (timeleft) {
>> + scsi_eh_restore_cmnd(scmd, &ses);
>> + timeleft -= stall_for;
>> + msleep(stall_for);
>
> Stall for is in HZ: need to convert to ms, so
>
> msleep(stall_for * 1000/HZ);
>
Right. Will be converting it.
> I also don't see a need to restore and reprep the command each time, but
> I don't see a problem with it either.
>
This was mainly thought as a safeguard here; just in case someone
else might be fiddling with the command. But yeah, it's not required.
Cheers,
Hannes
--
Dr. Hannes Reinecke zSeries & Storage
hare@xxxxxxx +49 911 74053 688
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg)
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