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Commit ad7660cc authored by Johannes Thumshirn's avatar Johannes Thumshirn Committed by Martin K. Petersen
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scsi: fc: implement kref backed reference counting 



Implement kref backed reference counting instead of rolling our own. This
elimnates the need of the following fields in 'struct fc_bsg_job':
* ref_cnt
* state_flags
* job_lock
bringing us close to unification of 'struct fc_bsg_job' and 'struct bsg_job'.

Signed-off-by: default avatarJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: default avatarHannes Reinecke <hare@suse.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 7ac65007

drivers/scsi/scsi_transport_fc.c

+11 −29
Original line number Diff line number Diff line
@@ -3560,16 +3560,12 @@ fc_vport_sched_delete(struct work_struct *work) 
 * @job:	fc_bsg_job that is to be torn down

 */

static void

fc_destroy_bsgjob(struct fc_bsg_job *job)

fc_destroy_bsgjob(struct kref *kref)

{

	unsigned long flags;

	struct fc_bsg_job *job = container_of(kref, struct fc_bsg_job, kref);

	struct request *rq = job->req;



	spin_lock_irqsave(&job->job_lock, flags);

	if (job->ref_cnt) {

		spin_unlock_irqrestore(&job->job_lock, flags);

		return;

	}

	spin_unlock_irqrestore(&job->job_lock, flags);

	blk_end_request_all(rq, rq->errors);



	put_device(job->dev);	/* release reference for the request */
@@ -3620,15 +3616,8 @@ EXPORT_SYMBOL_GPL(fc_bsg_jobdone); 
static void fc_bsg_softirq_done(struct request *rq)

{

	struct fc_bsg_job *job = rq->special;

	unsigned long flags;



	spin_lock_irqsave(&job->job_lock, flags);

	job->state_flags |= FC_RQST_STATE_DONE;

	job->ref_cnt--;

	spin_unlock_irqrestore(&job->job_lock, flags);



	blk_end_request_all(rq, rq->errors);

	fc_destroy_bsgjob(job);

	kref_put(&job->kref, fc_destroy_bsgjob);

}



/**
@@ -3642,24 +3631,18 @@ fc_bsg_job_timeout(struct request *req) 
	struct Scsi_Host *shost = fc_bsg_to_shost(job);

	struct fc_rport *rport = fc_bsg_to_rport(job);

	struct fc_internal *i = to_fc_internal(shost->transportt);

	unsigned long flags;

	int err = 0, done = 0;

	int err = 0, inflight = 0;



	if (rport && rport->port_state == FC_PORTSTATE_BLOCKED)

		return BLK_EH_RESET_TIMER;



	spin_lock_irqsave(&job->job_lock, flags);

	if (job->state_flags & FC_RQST_STATE_DONE)

		done = 1;

	else

		job->ref_cnt++;

	spin_unlock_irqrestore(&job->job_lock, flags);

	inflight = kref_get_unless_zero(&job->kref);



	if (!done && i->f->bsg_timeout) {

	if (inflight && i->f->bsg_timeout) {

		/* call LLDD to abort the i/o as it has timed out */

		err = i->f->bsg_timeout(job);

		if (err == -EAGAIN) {

			job->ref_cnt--;

			kref_put(&job->kref, fc_destroy_bsgjob);

			return BLK_EH_RESET_TIMER;

		} else if (err)

			printk(KERN_ERR "ERROR: FC BSG request timeout - LLD "
@@ -3667,7 +3650,7 @@ fc_bsg_job_timeout(struct request *req) 
	}



	/* the blk_end_sync_io() doesn't check the error */

	if (done)

	if (!inflight)

		return BLK_EH_NOT_HANDLED;

	else

		return BLK_EH_HANDLED;
@@ -3728,7 +3711,6 @@ fc_req_to_bsgjob(struct Scsi_Host *shost, struct fc_rport *rport, 
	job->req = req;

	if (i->f->dd_bsg_size)

		job->dd_data = (void *)&job[1];

	spin_lock_init(&job->job_lock);

	job->request = (struct fc_bsg_request *)req->cmd;

	job->request_len = req->cmd_len;

	job->reply = req->sense;
@@ -3750,7 +3732,7 @@ fc_req_to_bsgjob(struct Scsi_Host *shost, struct fc_rport *rport, 
		job->dev = &shost->shost_gendev;

	get_device(job->dev);		/* take a reference for the request */



	job->ref_cnt = 1;

	kref_init(&job->kref);



	return 0;

include/scsi/scsi_transport_fc.h

+1 −3
Original line number Diff line number Diff line
@@ -634,9 +634,7 @@ struct fc_bsg_job { 
	struct fc_rport *rport;

	struct device *dev;

	struct request *req;

	spinlock_t job_lock;

	unsigned int state_flags;

	unsigned int ref_cnt;

	struct kref kref;



	struct fc_bsg_request *request;

	struct fc_bsg_reply *reply;