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scsi: fc: move FC transport's bsg code to bsg-lib
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Now that all conversions are done, move the FibreChannel bsg code over
to the bsg library.

This patch is derived from work done by Mike Christie in 2011 [1] but
only the iscsi parts got merged back then.

[1] http://marc.info/?l=linux-scsi&m=131149780921009&w=2

Signed-off-by: Johannes Thumshirn <[email protected]>
Reviewed-by: Hannes Reinecke <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>
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Johannes Thumshirn authored and martinkpetersen committed Nov 18, 2016
1 parent fb6f7c8 commit a0f4bd7
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Showing 3 changed files with 44 additions and 245 deletions.
3 changes: 1 addition & 2 deletions block/bsg-lib.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -96,13 +96,12 @@ EXPORT_SYMBOL_GPL(bsg_job_done);
* bsg_softirq_done - softirq done routine for destroying the bsg requests
* @rq: BSG request that holds the job to be destroyed
*/
void bsg_softirq_done(struct request *rq)
static void bsg_softirq_done(struct request *rq)
{
struct bsg_job *job = rq->special;

bsg_job_put(job);
}
EXPORT_SYMBOL_GPL(bsg_softirq_done);

static int bsg_map_buffer(struct bsg_buffer *buf, struct request *req)
{
Expand Down
285 changes: 43 additions & 242 deletions drivers/scsi/scsi_transport_fc.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -3591,109 +3591,12 @@ fc_bsg_job_timeout(struct request *req)
return BLK_EH_HANDLED;
}

static int
fc_bsg_map_buffer(struct bsg_buffer *buf, struct request *req)
{
size_t sz = (sizeof(struct scatterlist) * req->nr_phys_segments);

BUG_ON(!req->nr_phys_segments);

buf->sg_list = kzalloc(sz, GFP_KERNEL);
if (!buf->sg_list)
return -ENOMEM;
sg_init_table(buf->sg_list, req->nr_phys_segments);
buf->sg_cnt = blk_rq_map_sg(req->q, req, buf->sg_list);
buf->payload_len = blk_rq_bytes(req);
return 0;
}


/**
* fc_req_to_bsgjob - Allocate/create the fc_bsg_job structure for the
* bsg request
* @shost: SCSI Host corresponding to the bsg object
* @rport: (optional) FC Remote Port corresponding to the bsg object
* @req: BSG request that needs a job structure
*/
static int
fc_req_to_bsgjob(struct Scsi_Host *shost, struct fc_rport *rport,
struct request *req)
{
struct fc_internal *i = to_fc_internal(shost->transportt);
struct request *rsp = req->next_rq;
struct bsg_job *job;
int ret;

BUG_ON(req->special);

job = kzalloc(sizeof(struct bsg_job) + i->f->dd_bsg_size,
GFP_KERNEL);
if (!job)
return -ENOMEM;

/*
* Note: this is a bit silly.
* The request gets formatted as a SGIO v4 ioctl request, which
* then gets reformatted as a blk request, which then gets
* reformatted as a fc bsg request. And on completion, we have
* to wrap return results such that SGIO v4 thinks it was a scsi
* status. I hope this was all worth it.
*/

req->special = job;
job->req = req;
if (i->f->dd_bsg_size)
job->dd_data = (void *)&job[1];
job->request = (struct fc_bsg_request *)req->cmd;
job->request_len = req->cmd_len;
job->reply = req->sense;
job->reply_len = SCSI_SENSE_BUFFERSIZE; /* Size of sense buffer
* allocated */
if (req->bio) {
ret = fc_bsg_map_buffer(&job->request_payload, req);
if (ret)
goto failjob_rls_job;
}
if (rsp && rsp->bio) {
ret = fc_bsg_map_buffer(&job->reply_payload, rsp);
if (ret)
goto failjob_rls_rqst_payload;
}
if (rport)
job->dev = &rport->dev;
else
job->dev = &shost->shost_gendev;
get_device(job->dev); /* take a reference for the request */

kref_init(&job->kref);

return 0;


failjob_rls_rqst_payload:
kfree(job->request_payload.sg_list);
failjob_rls_job:
kfree(job);
return -ENOMEM;
}


enum fc_dispatch_result {
FC_DISPATCH_BREAK, /* on return, q is locked, break from q loop */
FC_DISPATCH_LOCKED, /* on return, q is locked, continue on */
FC_DISPATCH_UNLOCKED, /* on return, q is unlocked, continue on */
};


/**
* fc_bsg_host_dispatch - process fc host bsg requests and dispatch to LLDD
* @q: fc host request queue
* @shost: scsi host rport attached to
* @job: bsg job to be processed
*/
static enum fc_dispatch_result
fc_bsg_host_dispatch(struct request_queue *q, struct Scsi_Host *shost,
struct bsg_job *job)
static int fc_bsg_host_dispatch(struct Scsi_Host *shost, struct bsg_job *job)
{
struct fc_internal *i = to_fc_internal(shost->transportt);
struct fc_bsg_request *bsg_request = job->request;
Expand Down Expand Up @@ -3754,7 +3657,7 @@ fc_bsg_host_dispatch(struct request_queue *q, struct Scsi_Host *shost,

ret = i->f->bsg_request(job);
if (!ret)
return FC_DISPATCH_UNLOCKED;
return 0;

fail_host_msg:
/* return the errno failure code as the only status */
Expand All @@ -3764,7 +3667,7 @@ fc_bsg_host_dispatch(struct request_queue *q, struct Scsi_Host *shost,
job->reply_len = sizeof(uint32_t);
bsg_job_done(job, bsg_reply->result,
bsg_reply->reply_payload_rcv_len);
return FC_DISPATCH_UNLOCKED;
return 0;
}


Expand All @@ -3788,14 +3691,10 @@ fc_bsg_goose_queue(struct fc_rport *rport)

/**
* fc_bsg_rport_dispatch - process rport bsg requests and dispatch to LLDD
* @q: rport request queue
* @shost: scsi host rport attached to
* @rport: rport request destined to
* @job: bsg job to be processed
*/
static enum fc_dispatch_result
fc_bsg_rport_dispatch(struct request_queue *q, struct Scsi_Host *shost,
struct fc_rport *rport, struct bsg_job *job)
static int fc_bsg_rport_dispatch(struct Scsi_Host *shost, struct bsg_job *job)
{
struct fc_internal *i = to_fc_internal(shost->transportt);
struct fc_bsg_request *bsg_request = job->request;
Expand Down Expand Up @@ -3832,7 +3731,7 @@ fc_bsg_rport_dispatch(struct request_queue *q, struct Scsi_Host *shost,

ret = i->f->bsg_request(job);
if (!ret)
return FC_DISPATCH_UNLOCKED;
return 0;

fail_rport_msg:
/* return the errno failure code as the only status */
Expand All @@ -3842,119 +3741,19 @@ fc_bsg_rport_dispatch(struct request_queue *q, struct Scsi_Host *shost,
job->reply_len = sizeof(uint32_t);
bsg_job_done(job, bsg_reply->result,
bsg_reply->reply_payload_rcv_len);
return FC_DISPATCH_UNLOCKED;
}


/**
* fc_bsg_request_handler - generic handler for bsg requests
* @q: request queue to manage
* @shost: Scsi_Host related to the bsg object
* @rport: FC remote port related to the bsg object (optional)
* @dev: device structure for bsg object
*/
static void
fc_bsg_request_handler(struct request_queue *q, struct Scsi_Host *shost,
struct fc_rport *rport, struct device *dev)
{
struct request *req;
struct bsg_job *job;
enum fc_dispatch_result ret;
struct fc_bsg_reply *bsg_reply;

if (!get_device(dev))
return;

while (1) {
if (rport && (rport->port_state == FC_PORTSTATE_BLOCKED) &&
!(rport->flags & FC_RPORT_FAST_FAIL_TIMEDOUT))
break;

req = blk_fetch_request(q);
if (!req)
break;

if (rport && (rport->port_state != FC_PORTSTATE_ONLINE)) {
req->errors = -ENXIO;
spin_unlock_irq(q->queue_lock);
blk_end_request_all(req, -ENXIO);
spin_lock_irq(q->queue_lock);
continue;
}

spin_unlock_irq(q->queue_lock);

ret = fc_req_to_bsgjob(shost, rport, req);
if (ret) {
req->errors = ret;
blk_end_request_all(req, ret);
spin_lock_irq(q->queue_lock);
continue;
}

job = req->special;

/* check if we have the msgcode value at least */
if (job->request_len < sizeof(uint32_t)) {
BUG_ON(job->reply_len < sizeof(uint32_t));
bsg_reply = job->reply;
bsg_reply->reply_payload_rcv_len = 0;
bsg_reply->result = -ENOMSG;
job->reply_len = sizeof(uint32_t);
bsg_job_done(job, bsg_reply->result,
bsg_reply->reply_payload_rcv_len);
spin_lock_irq(q->queue_lock);
continue;
}

/* the dispatch routines will unlock the queue_lock */
if (rport)
ret = fc_bsg_rport_dispatch(q, shost, rport, job);
else
ret = fc_bsg_host_dispatch(q, shost, job);

/* did dispatcher hit state that can't process any more */
if (ret == FC_DISPATCH_BREAK)
break;

/* did dispatcher had released the lock */
if (ret == FC_DISPATCH_UNLOCKED)
spin_lock_irq(q->queue_lock);
}

spin_unlock_irq(q->queue_lock);
put_device(dev);
spin_lock_irq(q->queue_lock);
}


/**
* fc_bsg_host_handler - handler for bsg requests for a fc host
* @q: fc host request queue
*/
static void
fc_bsg_host_handler(struct request_queue *q)
{
struct Scsi_Host *shost = q->queuedata;

fc_bsg_request_handler(q, shost, NULL, &shost->shost_gendev);
return 0;
}


/**
* fc_bsg_rport_handler - handler for bsg requests for a fc rport
* @q: rport request queue
*/
static void
fc_bsg_rport_handler(struct request_queue *q)
static int fc_bsg_dispatch(struct bsg_job *job)
{
struct fc_rport *rport = q->queuedata;
struct Scsi_Host *shost = rport_to_shost(rport);
struct Scsi_Host *shost = fc_bsg_to_shost(job);

fc_bsg_request_handler(q, shost, rport, &rport->dev);
if (scsi_is_fc_rport(job->dev))
return fc_bsg_rport_dispatch(shost, job);
else
return fc_bsg_host_dispatch(shost, job);
}


/**
* fc_bsg_hostadd - Create and add the bsg hooks so we can receive requests
* @shost: shost for fc_host
Expand All @@ -3977,33 +3776,42 @@ fc_bsg_hostadd(struct Scsi_Host *shost, struct fc_host_attrs *fc_host)
snprintf(bsg_name, sizeof(bsg_name),
"fc_host%d", shost->host_no);

q = __scsi_alloc_queue(shost, fc_bsg_host_handler);
q = __scsi_alloc_queue(shost, bsg_request_fn);
if (!q) {
printk(KERN_ERR "fc_host%d: bsg interface failed to "
"initialize - no request queue\n",
shost->host_no);
dev_err(dev,
"fc_host%d: bsg interface failed to initialize - no request queue\n",
shost->host_no);
return -ENOMEM;
}

q->queuedata = shost;
queue_flag_set_unlocked(QUEUE_FLAG_BIDI, q);
blk_queue_softirq_done(q, bsg_softirq_done);
blk_queue_rq_timed_out(q, fc_bsg_job_timeout);
blk_queue_rq_timeout(q, FC_DEFAULT_BSG_TIMEOUT);

err = bsg_register_queue(q, dev, bsg_name, NULL);
err = bsg_setup_queue(dev, q, bsg_name, fc_bsg_dispatch,
i->f->dd_bsg_size);
if (err) {
printk(KERN_ERR "fc_host%d: bsg interface failed to "
"initialize - register queue\n",
shost->host_no);
dev_err(dev,
"fc_host%d: bsg interface failed to initialize - setup queue\n",
shost->host_no);
blk_cleanup_queue(q);
return err;
}

blk_queue_rq_timed_out(q, fc_bsg_job_timeout);
blk_queue_rq_timeout(q, FC_DEFAULT_BSG_TIMEOUT);
fc_host->rqst_q = q;
return 0;
}

static int fc_bsg_rport_prep(struct request_queue *q, struct request *req)
{
struct fc_rport *rport = dev_to_rport(q->queuedata);

if (rport->port_state == FC_PORTSTATE_BLOCKED &&
!(rport->flags & FC_RPORT_FAST_FAIL_TIMEDOUT))
return BLKPREP_DEFER;

if (rport->port_state != FC_PORTSTATE_ONLINE)
return BLKPREP_KILL;

return BLKPREP_OK;
}

/**
* fc_bsg_rportadd - Create and add the bsg hooks so we can receive requests
Expand All @@ -4023,29 +3831,22 @@ fc_bsg_rportadd(struct Scsi_Host *shost, struct fc_rport *rport)
if (!i->f->bsg_request)
return -ENOTSUPP;

q = __scsi_alloc_queue(shost, fc_bsg_rport_handler);
q = __scsi_alloc_queue(shost, bsg_request_fn);
if (!q) {
printk(KERN_ERR "%s: bsg interface failed to "
"initialize - no request queue\n",
dev->kobj.name);
dev_err(dev, "bsg interface failed to initialize - no request queue\n");
return -ENOMEM;
}

q->queuedata = rport;
queue_flag_set_unlocked(QUEUE_FLAG_BIDI, q);
blk_queue_softirq_done(q, bsg_softirq_done);
blk_queue_rq_timed_out(q, fc_bsg_job_timeout);
blk_queue_rq_timeout(q, BLK_DEFAULT_SG_TIMEOUT);

err = bsg_register_queue(q, dev, NULL, NULL);
err = bsg_setup_queue(dev, q, NULL, fc_bsg_dispatch, i->f->dd_bsg_size);
if (err) {
printk(KERN_ERR "%s: bsg interface failed to "
"initialize - register queue\n",
dev->kobj.name);
dev_err(dev, "failed to setup bsg queue\n");
blk_cleanup_queue(q);
return err;
}

blk_queue_prep_rq(q, fc_bsg_rport_prep);
blk_queue_rq_timed_out(q, fc_bsg_job_timeout);
blk_queue_rq_timeout(q, BLK_DEFAULT_SG_TIMEOUT);
rport->rqst_q = q;
return 0;
}
Expand Down
1 change: 0 additions & 1 deletion include/linux/bsg-lib.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -69,7 +69,6 @@ void bsg_job_done(struct bsg_job *job, int result,
int bsg_setup_queue(struct device *dev, struct request_queue *q, char *name,
bsg_job_fn *job_fn, int dd_job_size);
void bsg_request_fn(struct request_queue *q);
void bsg_softirq_done(struct request *rq);
void bsg_job_put(struct bsg_job *job);
int __must_check bsg_job_get(struct bsg_job *job);

Expand Down

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