Re: [PATCH 1/2] scsi_transport_fc: FC pass through support via bsg interface - revised

FUJITA Tomonori
2008-10-14T02:23:33Z

On Mon, 13 Oct 2008 11:14:56 -0700
Seokmann Ju <seokmann.ju@qlogic.com> wrote:

>
> On Oct 13, 2008, at 10:53 AM, Seokmann Ju wrote:
>
> > Signed-off-by: Seokmann Ju <seokmann.ju@qlogic.com>
> > ---
> By mistake, I placed patches so that it won't match with the subject.
> Sorry for the shortcomings.
> Here is the patch for scsi_transport_fc module.
>
> Signed-off-by: Seokmann Ju <seokmann.ju@qlogic.com>
> ---
> diff --git a/drivers/scsi/scsi_transport_fc.c b/drivers/scsi/
> scsi_transport_fc.c
> index cb971f0..dda12e0 100644
> --- a/drivers/scsi/scsi_transport_fc.c
> +++ b/drivers/scsi/scsi_transport_fc.c
> @@ -43,6 +43,11 @@ static void fc_vport_sched_delete(struct
> work_struct *work);
> static int fc_vport_setup(struct Scsi_Host *shost, int channel,
> struct device *pdev, struct fc_vport_identifiers *ids,
> struct fc_vport **vport);
> +static void fc_service_timeout(unsigned long);
> +static void fc_service_done(struct fc_service *);
> +static int fc_service_handler(struct Scsi_Host *, struct fc_rport *,
> + struct request *, struct request_queue *);
> +static void fc_bsg_remove(struct Scsi_Host *, struct fc_rport *);
>
> /*
> * Redefine so that we can have same named attributes in the
> @@ -2406,12 +2411,194 @@ fc_rport_final_delete(struct work_struct *work)
>
> transport_remove_device(dev);
> device_del(dev);
> + fc_bsg_remove(shost, rport);
> transport_destroy_device(dev);
> put_device(&shost->shost_gendev); /* for fc_host->rport list */
> put_device(dev); /* for self-reference */
> }
>
>
> +static void fc_service_timeout(unsigned long _service)
> +{
> + struct fc_service *service = (void *) _service;
> + unsigned long flags;
> +
> + spin_lock_irqsave(&service->service_state_lock, flags);
> + if (!(service->service_state_flag & FC_SERVICE_STATE_DONE))
> + service->service_state_flag |= FC_SERVICE_STATE_TIMEOUT;
> + spin_unlock_irqrestore(&service->service_state_lock, flags);
> +}

Hmm, this function is not used? Using rq_timed_out_fn is todo?

> +static void fc_service_done(struct fc_service *service)
> +{
> + if (service->service_state_flag != FC_SERVICE_STATE_DONE) {
> + if (service->service_state_flag == FC_SERVICE_STATE_TIMEOUT) {
> + printk(KERN_ERR "ERROR: FC service timed out\n");
> + /* expect abort to be issued by the application */
> + return;
> + } else
> + printk(KERN_ERR "ERROR: FC service not finished\n");
> + }
> +
> + if (service->srv_reply.status != FC_SERVICE_COMPLETE) {
> + printk(KERN_ERR "ERROR: FC service to rport %p failed with"
> + " status 0x%x\n", service->rport,
> + service->srv_reply.status);
> + }
> +
> + if (service->srv_reply.residual) {
> + service->req->data_len = 0;
> + service->req->next_rq->data_len = service->srv_reply.residual;
> + } else {
> + service->req->data_len = 0;
> + service->req->next_rq->data_len = 0;
> + }
> +
> + service->req->end_io(service->req, 0);
> + kfree(service);
> +}
> +
> +static int
> +issue_fc_service(struct fc_rport *rport, struct request *req,
> + struct request *rsp, struct request_queue *q)
> +{
> + int res = -ECOMM;
> + struct fc_service *service;
> + struct Scsi_Host *shost = rport_to_shost(rport);
> + struct fc_internal *i = to_fc_internal(shost->transportt);
> + struct fc_service_request *srv_request = (struct fc_service_request *)
> + req->cmd;
> +
> + service = kzalloc(sizeof (struct fc_service), GFP_KERNEL);
> + if (!service)
> + return -ENOMEM;
> +
> + service->rport = rport;
> + service->req = req;
> + service->q = q;
> + service->srv_request = srv_request;
> +
> + sg_init_table(service->payload_dma, FC_SERVICE_MAX_SG);
> + service->payload_sg_cnt =
> + blk_rq_map_sg(q, req, service->payload_dma);
> + service->payload = (void *) bio_data(req->bio);

You use scatter-gather for data transfer so bio_data should not be
used.

> + service->payload_size = req->data_len;
> +
> + sg_init_table(service->response_dma, FC_SERVICE_MAX_SG);
> + service->response_sg_cnt =
> + blk_rq_map_sg(q, rsp, service->response_dma);
> + service->response = bio_data(rsp->bio);
> + service->response_size = rsp->data_len;
> +
> + /* sense area of the request structure */
> + service->reply_seq = req->sense;
> + service->service_done = fc_service_done;
> + service->service_state_flag = FC_SERVICE_STATE_PENDING;
> +
> + if (i->f->execute_fc_service)
> + res = i->f->execute_fc_service(service);
> +
> + if (res) {
> + printk(KERN_ERR "ERROR: issuing FC service to the LLD "
> + "failed with status %d\n", res);
> + fc_service_done(service);
> + return res;
> + }
> +
> + return 0;
> +}
> +
> +static int
> +fc_service_handler(struct Scsi_Host *shost, struct fc_rport *rport,
> + struct request *req, struct request_queue *q)
> +{
> + int ret;
> + struct request *rsp = req->next_rq;
> +
> + if (!rsp) {
> + printk(KERN_ERR "ERROR: space for a FC service"
> + " response is missing\n");
> + return -EINVAL;
> + }
> +
> + if ((req->bio->bi_vcnt > FC_SERVICE_MAX_SG) ||
> + (rsp->bio->bi_vcnt > FC_SERVICE_MAX_SG)) {
> + printk(KERN_ERR "ERROR: a FC service"
> + " supports no more than %d SGs\n", FC_SERVICE_MAX_SG);
> + return -EINVAL;
> + }

This doesn't look correct. bi_vcnt is not related with the number of
sg. You use scatter-gather for large data transfer. You don't need to
worry about bi_vcnt.

> + ret = issue_fc_service(rport, req, rsp, q);
> +
> + return ret;
> +}
> +
> +static void fc_service_dispatch(struct request_queue *q)
> +{
> + struct request *req;
> + struct fc_rport *rport = q->queuedata;
> + struct Scsi_Host *shost = rport_to_shost(rport);
> +
> + while (!blk_queue_plugged(q)) {
> + req = elv_next_request(q);
> + if (!req)
> + break;
> +
> + blkdev_dequeue_request(req);
> + spin_unlock_irq(q->queue_lock);
> +
> + fc_service_handler(shost, rport, req, q);
> +
> + spin_lock_irq(q->queue_lock);
> + }
> +}
> +
> +static int
> +fc_bsg_initialize(struct Scsi_Host *shost, struct fc_rport *rport)
> +{
> + struct request_queue *q;
> + int error;
> + struct device *dev;
> + const char *name;
> + void (*release)(struct device *);
> +
> + if (!rport) {
> + printk(KERN_ERR "ERROR: rport is NULL\n");
> + return -ENOMEM;
> + }
> +
> + q = blk_init_queue(fc_service_dispatch, NULL);
> + if (!q)
> + return -ENOMEM;
> +
> + dev = &rport->dev;
> + name = dev->bus_id;
> + release = NULL;
> +
> + error = bsg_register_queue(q, dev, name, release);
> + if (error) {
> + blk_cleanup_queue(q);
> + return -ENOMEM;
> + }

I think that you need to call blk_queue_max_hw_segments and
blk_queue_max_phys_segments here with FC_SERVICE_MAX_SG.

> +
> + rport->q = q;
> + q->queuedata = rport;
> + queue_flag_set_unlocked(QUEUE_FLAG_BIDI, q);
> +
> + return 0;
> +}
> +
> +static void
> +fc_bsg_remove(struct Scsi_Host *shost, struct fc_rport *rport)
> +{
> + struct request_queue *q = rport->q;
> +
> + if (!q)
> + return;
> +
> + bsg_unregister_queue(q);
> +}
> +
> /**
> * fc_rport_create - allocates and creates a remote FC port.
> * @shost: scsi host the remote port is connected to.
> @@ -2471,8 +2658,8 @@ fc_rport_create(struct Scsi_Host *shost, int
> channel,
> else
> rport->scsi_target_id = -1;
> list_add_tail(&rport->peers, &fc_host->rports);
> - get_device(&shost->shost_gendev); /* for fc_host->rport list */
>
> + get_device(&shost->shost_gendev); /* for fc_host->rport list */
> spin_unlock_irqrestore(shost->host_lock, flags);
>
> dev = &rport->dev;
> @@ -2491,6 +2678,8 @@ fc_rport_create(struct Scsi_Host *shost, int
> channel,
> transport_add_device(dev);
> transport_configure_device(dev);
>
> + fc_bsg_initialize(shost, rport);
> +
> if (rport->roles & FC_PORT_ROLE_FCP_TARGET) {
> /* initiate a scan of the target */
> rport->flags |= FC_RPORT_SCAN_PENDING;
> diff --git a/include/scsi/scsi_transport_fc.h b/include/scsi/
> scsi_transport_fc.h
> index 21018a4..6c6809a 100644
> --- a/include/scsi/scsi_transport_fc.h
> +++ b/include/scsi/scsi_transport_fc.h
> @@ -33,7 +33,6 @@
>
> struct scsi_transport_template;
>
> -
> /*
> * FC Port definitions - Following FC HBAAPI guidelines
> *
> @@ -352,6 +351,7 @@ struct fc_rport { /* aka fc_starget_attrs */
> struct delayed_work fail_io_work;
> struct work_struct stgt_delete_work;
> struct work_struct rport_delete_work;
> + struct request_queue *q;
> } __attribute__((aligned(sizeof(unsigned long))));
>
> /* bit field values for struct fc_rport "flags" field: */
> @@ -514,6 +514,81 @@ struct fc_host_attrs {
> struct workqueue_struct *devloss_work_q;
> };
>
> +#define FC_STATUS_BUF_SIZE 96
> +
> +enum fc_frame_type {
> + FC_FRAME_TYPE_BS,
> + FC_FRAME_TYPE_ELS,
> + FC_FRAME_TYPE_IEC = 4,
> + FC_FRAME_TYPE_IP,
> + FC_FRAME_TYPE_FCP = 8,
> + FC_FRAME_TYPE_GPP,
> + FC_FRAME_TYPE_FC_CT = 0x20,
> +};
> +
> +enum fc_service_status {
> + FC_SERVICE_COMPLETE,
> + FC_SERVICE_TIMEOUT,
> + FC_SERVICE_ABORT,
> + FC_SERVICE_UNSUPPORTED,
> + FC_SERVICE_ERROR = -1,
> +};
> +
> +#define FC_SERVICE_STATE_PENDING 1
> +#define FC_SERVICE_STATE_DONE 2
> +#define FC_SERVICE_STATE_ABORTED 4
> +#define FC_SERVICE_STATE_TIMEOUT 8
> +
> +#define FC_SERVICE_TIMEOUT 10
> +#define FC_SERVICE_MAX_SG 16
> +
> +/* request (CDB) structure of the sg_io_v4 */
> +struct fc_service_request {
> + u8 request_type;
> + u8 timeout;
> + u8 reserved0;
> + u8 reserved1;
> +};
> +
> +/* response (request sense data) structure of the sg_io_v4 */
> +struct fc_service_reply {
> + enum fc_service_status status;
> + u16 error_code;
> + u16 additional_error_code;
> + u32 residual;
> +};
> +
> +struct fc_service {
> + struct fc_rport *rport;
> + struct list_head list;
> +
> + spinlock_t service_state_lock;
> + unsigned service_state_flag;
> +
> + struct request *req;
> + struct request_queue *q;
> +
> + /* Used by the discovery code. */
> + struct timer_list timer;
> + struct completion completion;
> +
> + struct fc_service_request *srv_request;
> + void *payload;
> + struct scatterlist payload_dma[FC_SERVICE_MAX_SG];
> + int payload_sg_cnt;
> + int payload_size;
> + void *response;
> + struct scatterlist response_dma[FC_SERVICE_MAX_SG];
> + int response_sg_cnt;
> + int response_size;
> +
> + struct fc_service_reply srv_reply;
> + void *reply_seq; /* pointer to sense area of request */
> + void (*service_done)(struct fc_service *);
> +
> + void *lld_pkt;
> +};
> +
> #define shost_to_fc_host(x) \
> ((struct fc_host_attrs *)(x)->shost_data)
>
> @@ -612,6 +687,10 @@ struct fc_function_template {
> int (* tsk_mgmt_response)(struct Scsi_Host *, u64, u64, int);
> int (* it_nexus_response)(struct Scsi_Host *, u64, int);
>
> + /* fc service handler */
> + int (*execute_fc_service)(struct fc_service *);
> + int (*abort_fc_service)(struct fc_service *);
> +
> /* allocation lengths for host-specific data */
> u32 dd_fcrport_size;
> u32 dd_fcvport_size;
> @@ -732,7 +811,6 @@ fc_vport_set_state(struct fc_vport *vport, enum
> fc_vport_state new_state)
> vport->vport_state = new_state;
> }
>
> -
> struct scsi_transport_template *fc_attach_transport(
> struct fc_function_template *);
> void fc_release_transport(struct scsi_transport_template *);
> ---
> --
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