Re: [PATCH 17/24] snic: reserve tag for TMF

[John Garry <john.garry@xxxxxxxxxx>]

>   
> diff --git a/drivers/scsi/snic/snic_main.c b/drivers/scsi/snic/snic_main.c
> index 29d56396058c..f344cbc27923 100644
> --- a/drivers/scsi/snic/snic_main.c
> +++ b/drivers/scsi/snic/snic_main.c
> @@ -512,6 +512,9 @@ snic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
>   					 max_t(u32, SNIC_MIN_IO_REQ, max_ios));
>   
>   	snic->max_tag_id = shost->can_queue;
> +	/* Reserve one reset command */
> +	shost->can_queue--;
> +	snic->tmf_tag_id = shost->can_queue;
>   
>   	shost->max_lun = snic->config.luns_per_tgt;
>   	shost->max_id = SNIC_MAX_TARGET;
> diff --git a/drivers/scsi/snic/snic_scsi.c b/drivers/scsi/snic/snic_scsi.c
> index 5f17666f3e1d..e18c8c5e4b46 100644
> --- a/drivers/scsi/snic/snic_scsi.c
> +++ b/drivers/scsi/snic/snic_scsi.c
> @@ -1018,17 +1018,6 @@ snic_hba_reset_cmpl_handler(struct snic *snic, struct snic_fw_req *fwreq)
>   		      "reset_cmpl: type = %x, hdr_stat = %x, cmnd_id = %x, hid = %x, ctx = %lx\n",
>   		      typ, hdr_stat, cmnd_id, hid, ctx);
>   
> -	/* spl case, host reset issued through ioctl */
> -	if (cmnd_id == SCSI_NO_TAG) {
> -		rqi = (struct snic_req_info *) ctx;
> -		SNIC_HOST_INFO(snic->shost,
> -			       "reset_cmpl:Tag %d ctx %lx cmpl stat %s\n",
> -			       cmnd_id, ctx, snic_io_status_to_str(hdr_stat));
> -		sc = rqi->sc;
> -
> -		goto ioctl_hba_rst;
> -	}
> -
>   	if (cmnd_id >= snic->max_tag_id) {
>   		SNIC_HOST_ERR(snic->shost,
>   			      "reset_cmpl: Tag 0x%x out of Range,HdrStat %s\n",
> @@ -1039,7 +1028,6 @@ snic_hba_reset_cmpl_handler(struct snic *snic, struct snic_fw_req *fwreq)
>   	}
>   
>   	sc = scsi_host_find_tag(snic->shost, cmnd_id);
> -ioctl_hba_rst:
>   	if (!sc) {
>   		atomic64_inc(&snic->s_stats.io.sc_null);
>   		SNIC_HOST_ERR(snic->shost,
> @@ -1725,7 +1713,7 @@ snic_dr_clean_single_req(struct snic *snic,
>   {
>   	struct snic_req_info *rqi = NULL;
>   	struct snic_tgt *tgt = NULL;
> -	struct scsi_cmnd *sc = NULL;
> +	struct scsi_cmnd *sc;
>   	spinlock_t *io_lock = NULL;
>   	u32 sv_state = 0, tmf = 0;
>   	DECLARE_COMPLETION_ONSTACK(tm_done);
> @@ -2238,13 +2226,6 @@ snic_issue_hba_reset(struct snic *snic, struct scsi_cmnd *sc)
>   		goto hba_rst_end;
>   	}
>   
> -	if (snic_cmd_tag(sc) == SCSI_NO_TAG) {
> -		memset(scsi_cmd_priv(sc), 0,
> -			sizeof(struct snic_internal_io_state));
> -		SNIC_HOST_INFO(snic->shost, "issu_hr:Host reset thru ioctl.\n");
> -		rqi->sc = sc;
> -	}
> -
>   	req = rqi_to_req(rqi);
>   
>   	io_lock = snic_io_lock_hash(snic, sc);
> @@ -2319,11 +2300,13 @@ snic_issue_hba_reset(struct snic *snic, struct scsi_cmnd *sc)
>   } /* end of snic_issue_hba_reset */
>   
>   int
> -snic_reset(struct Scsi_Host *shost, struct scsi_cmnd *sc)
> +snic_reset(struct Scsi_Host *shost)
>   {
>   	struct snic *snic = shost_priv(shost);
> +	struct scsi_cmnd *sc = NULL;
>   	enum snic_state sv_state;
>   	unsigned long flags;
> +	u32 start_time  = jiffies;
>   	int ret = FAILED;
>   
>   	/* Set snic state as SNIC_FWRESET*/
> @@ -2348,6 +2331,18 @@ snic_reset(struct Scsi_Host *shost, struct scsi_cmnd *sc)
>   	while (atomic_read(&snic->ios_inflight))
>   		schedule_timeout(msecs_to_jiffies(1));
>   
> +	sc = scsi_host_find_tag(shost, snic->tmf_tag_id);

Maybe I am missing something but this does not seem right. As I see, 
blk-mq has driver tags in range [0, snic->tmf_tag_id - 1], so we cannot 
call scsi_host_find_tag() -> blk_mq_unique_tag_to_tag(snic->tmf_tag_id)

thanks,
John