Re: [PATCH v3 4/6] scsi: Retry unaligned zoned writes

[Damien Le Moal <dlemoal@kernel.org>]

On 7/27/23 00:02, Bart Van Assche wrote:
> On 7/26/23 01:47, Damien Le Moal wrote:
>> On 7/26/23 09:57, Bart Van Assche wrote:
>>> +/*
>>> + * Returns a negative value if @_a has a lower LBA than @_b, zero if
>>> + * both have the same LBA and a positive value otherwise.
>>> + */
>>> +static int scsi_cmp_lba(void *priv, const struct list_head *_a,
>>> +            const struct list_head *_b)
>>
>> The argument priv is unused.
> 
> I cannot remove the 'priv' argument. From include/linux/list_sort.h:
> 
> typedef int __attribute__((nonnull(2,3))) (*list_cmp_func_t)(void *,
>         const struct list_head *, const struct list_head *);
> 
> __attribute__((nonnull(2,3)))
> void list_sort(void *priv, struct list_head *head, list_cmp_func_t cmp);

Yes. I missed that this is a callbalck. Sorry for the noise.

> 
>>>   /**
>>>    * scsi_unjam_host - Attempt to fix a host which has a cmd that failed.
>>>    * @shost:    Host to unjam.
>>> @@ -2258,6 +2289,12 @@ static void scsi_unjam_host(struct Scsi_Host *shost)
>>>         SCSI_LOG_ERROR_RECOVERY(1, scsi_eh_prt_fail_stats(shost, &eh_work_q));
>>>   +    /*
>>> +     * Sort pending SCSI commands in LBA order. This is important if zone
>>> +     * write locking is disabled for a zoned SCSI device.
>>> +     */
>>> +    list_sort(NULL, &eh_work_q, scsi_cmp_lba);
>>
>> Should we do this only for zoned devices ?
> 
> I'm not sure this is possible. Error handling happens per SCSI host. Some of
> the logical units associated with a host may be zoned while others may
> represent conventional storage or have no storage associated with them (WLUN).
> 
> Thanks,
> 
> Bart.

-- 
Damien Le Moal
Western Digital Research