Re: scsi: Always retry internal target error
> On 10/17/2017 09:11 AM, Hannes Reinecke wrote:
>> EMC Symmetrix is returning 'internal target error' for a variety
>> of conditions, most of which will be transient.
>> So we should always retry it, even with failfast set.
>> Otherwise we'd get spurious path flaps with multipath.
>>
>> Signed-off-by: Hannes Reinecke
>> ---
>> drivers/scsi/scsi_error.c | 13 +
>> 1 file changed, 13 insertions(+)
>>
>> diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
>> index 5086489..5722c2e 100644
>> --- a/drivers/scsi/scsi_error.c
>> +++ b/drivers/scsi/scsi_error.c
>> @@ -497,6 +497,16 @@ int scsi_check_sense(struct scsi_cmnd *scmd)
>> if (sshdr.asc == 0x10) /* DIF */
>> return SUCCESS;
>>
>> +if (!strncmp(scmd->device->vendor, "EMC", 3) &&
>> +!strncmp(scmd->device->model, "SYMMETRIX", 9) &&
>> +(sshdr.asc == 0x44) && (sshdr.ascq == 0x0)) {
>> +/*
>> + * EMC Symmetrix returns 'Internal target failure'
>> + * for a variety of internal issues, all of which
>> + * can be recovered by retry.
>> + */
>> +return ADD_TO_MLQUEUE;
>> +}
>> return NEEDS_RETRY;
>> case NOT_READY:
>> case UNIT_ATTENTION:
>> @@ -1846,6 +1856,9 @@ int scsi_decide_disposition(struct scsi_cmnd *scmd)
>> rtn = scsi_check_sense(scmd);
>> if (rtn == NEEDS_RETRY)
>> goto maybe_retry;
>> +else if (rtn == ADD_TO_MLQUEUE)
>> +/* Always enforce a retry for ADD_TO_MLQUEUE */
>> +rtn = NEEDS_RETRY;
>> /* if rtn == FAILED, we have no sense information;
>> * returning FAILED will wake the error handler thread
>> * to collect the sense and redo the decide
>>
On 10/18/2017 07:27 AM, Hannes Reinecke wrote:
>> Yeah, you are right.
>> Will be adding a blacklist entry for this.
Is there a new patch ongoing?
Re: [PATCH] scsi: Always retry internal target error
On 10/18/2017 08:34 AM, Christoph Hellwig wrote: > On Wed, Oct 18, 2017 at 08:15:46AM +0200, Hannes Reinecke wrote: >>> It's decidedly awful to have vendor/model-specific triggers in >>> scsi_error. >>> >>> What are the drawbacks of just always refiring on AC/0x44/ITF? >>> >> Hmm. 'Internal target failure' is not very descriptive, so it could mean >> anything. Hence the rather awkward approach. >> But I just checked with the qemu code, and that returns 0x44/0x00 only >> if some (internal) call returned with -ENOMEM. >> So I guess we're safe to always retry here. > > And even if not we should add a quirk so that we can just check a > bit instead of doing two string compares in the I/O completion path.. > Yeah, you are right. Will be adding a blacklist entry for this. Cheers, Hannes -- Dr. Hannes ReineckeTeamlead Storage & Networking h...@suse.de +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)
Re: [PATCH] scsi: Always retry internal target error
On Wed, Oct 18, 2017 at 08:15:46AM +0200, Hannes Reinecke wrote: > > It's decidedly awful to have vendor/model-specific triggers in > > scsi_error. > > > > What are the drawbacks of just always refiring on AC/0x44/ITF? > > > Hmm. 'Internal target failure' is not very descriptive, so it could mean > anything. Hence the rather awkward approach. > But I just checked with the qemu code, and that returns 0x44/0x00 only > if some (internal) call returned with -ENOMEM. > So I guess we're safe to always retry here. And even if not we should add a quirk so that we can just check a bit instead of doing two string compares in the I/O completion path..
Re: [PATCH] scsi: Always retry internal target error
On 10/18/2017 04:58 AM, Martin K. Petersen wrote:
>
> Hannes,
>
>> +if (!strncmp(scmd->device->vendor, "EMC", 3) &&
>> +!strncmp(scmd->device->model, "SYMMETRIX", 9) &&
>> +(sshdr.asc == 0x44) && (sshdr.ascq == 0x0)) {
>> +/*
>> + * EMC Symmetrix returns 'Internal target failure'
>> + * for a variety of internal issues, all of which
>> + * can be recovered by retry.
>> + */
>> +return ADD_TO_MLQUEUE;
>> +}
>
> It's decidedly awful to have vendor/model-specific triggers in
> scsi_error.
>
> What are the drawbacks of just always refiring on AC/0x44/ITF?
>
Hmm. 'Internal target failure' is not very descriptive, so it could mean
anything. Hence the rather awkward approach.
But I just checked with the qemu code, and that returns 0x44/0x00 only
if some (internal) call returned with -ENOMEM.
So I guess we're safe to always retry here.
Cheers,
Hannes
--
Dr. Hannes ReineckeTeamlead Storage & Networking
h...@suse.de +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)
Re: [PATCH] scsi: Always retry internal target error
Hannes,
> + if (!strncmp(scmd->device->vendor, "EMC", 3) &&
> + !strncmp(scmd->device->model, "SYMMETRIX", 9) &&
> + (sshdr.asc == 0x44) && (sshdr.ascq == 0x0)) {
> + /*
> + * EMC Symmetrix returns 'Internal target failure'
> + * for a variety of internal issues, all of which
> + * can be recovered by retry.
> + */
> + return ADD_TO_MLQUEUE;
> + }
It's decidedly awful to have vendor/model-specific triggers in
scsi_error.
What are the drawbacks of just always refiring on AC/0x44/ITF?
--
Martin K. Petersen Oracle Linux Engineering
[PATCH] scsi: Always retry internal target error
EMC Symmetrix is returning 'internal target error' for a variety
of conditions, most of which will be transient.
So we should always retry it, even with failfast set.
Otherwise we'd get spurious path flaps with multipath.
Signed-off-by: Hannes Reinecke
---
drivers/scsi/scsi_error.c | 13 +
1 file changed, 13 insertions(+)
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index 5086489..5722c2e 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -497,6 +497,16 @@ int scsi_check_sense(struct scsi_cmnd *scmd)
if (sshdr.asc == 0x10) /* DIF */
return SUCCESS;
+ if (!strncmp(scmd->device->vendor, "EMC", 3) &&
+ !strncmp(scmd->device->model, "SYMMETRIX", 9) &&
+ (sshdr.asc == 0x44) && (sshdr.ascq == 0x0)) {
+ /*
+* EMC Symmetrix returns 'Internal target failure'
+* for a variety of internal issues, all of which
+* can be recovered by retry.
+*/
+ return ADD_TO_MLQUEUE;
+ }
return NEEDS_RETRY;
case NOT_READY:
case UNIT_ATTENTION:
@@ -1846,6 +1856,9 @@ int scsi_decide_disposition(struct scsi_cmnd *scmd)
rtn = scsi_check_sense(scmd);
if (rtn == NEEDS_RETRY)
goto maybe_retry;
+ else if (rtn == ADD_TO_MLQUEUE)
+ /* Always enforce a retry for ADD_TO_MLQUEUE */
+ rtn = NEEDS_RETRY;
/* if rtn == FAILED, we have no sense information;
* returning FAILED will wake the error handler thread
* to collect the sense and redo the decide
--
1.8.5.6
