Hi Brian,
Thanks for reviewing.
All good suggestions that I am fine with implementing. As these are fairly
minor,
would you be okay with these being made in a separate ‘fix' patch series?
-matt
> On Aug 17, 2015, at 9:38 AM, Brian King <brk...@linux.vnet.ibm.com> wrote:
>
> On 08/13/2015 09:47 PM, Matthew R. Ochs wrote:
>> --- a/drivers/scsi/cxlflash/common.h
>> +++ b/drivers/scsi/cxlflash/common.h
>> @@ -76,6 +76,12 @@ enum cxlflash_init_state {
>> INIT_STATE_SCSI
>> };
>>
>> +enum cxlflash_state {
>> + STATE_NORMAL, /* Normal running state, everything good */
>> + STATE_LIMBO, /* Limbo running state, trying to reset/recover */
>
> Might be more clear to call this STATE_RESETTING or STATE_RECOVERY
>
>> + STATE_FAILTERM /* Failed/terminating state, error out users/threads */
>> +};
>> +
>> /*
>> * Each context has its own set of resource handles that is visible
>> * only from that context.
>
>> @@ -105,7 +109,8 @@ struct cxlflash_cfg {
>>
>> wait_queue_head_t tmf_waitq;
>> bool tmf_active;
>> - u8 err_recovery_active:1;
>> + wait_queue_head_t limbo_waitq;
>
> How about reset_waitq instead?
>
>> + enum cxlflash_state state;
>> };
>>
>> struct afu_cmd {
>
>> @@ -455,9 +471,21 @@ static int cxlflash_eh_device_reset_handler(struct
>> scsi_cmnd *scp)
>> get_unaligned_be32(&((u32 *)scp->cmnd)[2]),
>> get_unaligned_be32(&((u32 *)scp->cmnd)[3]));
>>
>> - rcr = send_tmf(afu, scp, TMF_LUN_RESET);
>> - if (unlikely(rcr))
>> + switch (cfg->state) {
>> + case STATE_NORMAL:
>> + rcr = send_tmf(afu, scp, TMF_LUN_RESET);
>> + if (unlikely(rcr))
>> + rc = FAILED;
>> + break;
>> + case STATE_LIMBO:
>> + wait_event(cfg->limbo_waitq, cfg->state != STATE_LIMBO);
>> + if (cfg->state == STATE_NORMAL)
>> + break;
>
> In this case you've been asked to do a LUN reset but didn't actually reset
> the LUN. I'd suggest
> restructuring this switch statement to send the LUN reset TMF in the case
> where you had
> to wait for an AFU reset to complete.
>
>> + /* fall through */
>> + default:
>> rc = FAILED;
>> + break;
>> + }
>>
>> pr_debug("%s: returning rc=%d\n", __func__, rc);
>> return rc;
>> @@ -487,11 +515,29 @@ static int cxlflash_eh_host_reset_handler(struct
>> scsi_cmnd *scp)
>> get_unaligned_be32(&((u32 *)scp->cmnd)[2]),
>> get_unaligned_be32(&((u32 *)scp->cmnd)[3]));
>>
>> - rcr = cxlflash_afu_reset(cfg);
>> - if (rcr == 0)
>> - rc = SUCCESS;
>> - else
>> + switch (cfg->state) {
>> + case STATE_NORMAL:
>> + cfg->state = STATE_LIMBO;
>> + scsi_block_requests(cfg->host);
>> +
>> + rcr = cxlflash_afu_reset(cfg);
>> + if (rcr) {
>> + rc = FAILED;
>> + cfg->state = STATE_FAILTERM;
>> + } else
>> + cfg->state = STATE_NORMAL;
>> + wake_up_all(&cfg->limbo_waitq);
>> + scsi_unblock_requests(cfg->host);
>
> The scsi_block_requests / scsi_unblock_requests is not necessary in this
> path, since SCSI EH
> will already be preventing any new commands being issued via queuecommand.
>
>> + break;
>> + case STATE_LIMBO:
>> + wait_event(cfg->limbo_waitq, cfg->state != STATE_LIMBO);
>> + if (cfg->state == STATE_NORMAL)
>> + break;
>> + /* fall through */
>> + default:
>> rc = FAILED;
>> + break;
>> + }
>>
>> pr_debug("%s: returning rc=%d\n", __func__, rc);
>> return rc;
>> @@ -642,7 +688,7 @@ static void cxlflash_wait_for_pci_err_recovery(struct
>> cxlflash_cfg *cfg)
>> struct pci_dev *pdev = cfg->dev;
>>
>> if (pci_channel_offline(pdev))
>> - wait_event_timeout(cfg->eeh_waitq,
>> + wait_event_timeout(cfg->limbo_waitq,
>> !pci_channel_offline(pdev),
>> CXLFLASH_PCI_ERROR_RECOVERY_TIMEOUT);
>> }
>> @@ -825,6 +871,8 @@ static void cxlflash_remove(struct pci_dev *pdev)
>> !cfg->tmf_active);
>> spin_unlock_irqrestore(&cfg->tmf_waitq.lock, lock_flags);
>>
>> + cfg->state = STATE_FAILTERM;
>
> I don't see any locking around the setting or reading of this flag. What are
> the
> implications if the processor reorders the store to change this state either
> here
> or elsewhere. Same goes for the load associated with checking the state.
>
>> +
>> switch (cfg->init_state) {
>> case INIT_STATE_SCSI:
>> scsi_remove_host(cfg->host);
>> @@ -1879,6 +1927,8 @@ static int init_afu(struct cxlflash_cfg *cfg)
>> struct afu *afu = cfg->afu;
>> struct device *dev = &cfg->dev->dev;
>>
>> + cxl_perst_reloads_same_image(cfg->cxl_afu, true);
>> +
>> rc = init_mc(cfg);
>> if (rc) {
>> dev_err(dev, "%s: call to init_mc failed, rc=%d!\n",
>
> Reviewed-by: Brian King <brk...@linux.vnet.ibm.com>
>
> --
> Brian King
> Power Linux I/O
> IBM Linux Technology Center
>
>
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