Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933217AbcJLNL1 (ORCPT ); Wed, 12 Oct 2016 09:11:27 -0400 Received: from mx2.suse.de ([195.135.220.15]:37775 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755325AbcJLNIF (ORCPT ); Wed, 12 Oct 2016 09:08:05 -0400 X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" From: Johannes Thumshirn To: "Martin K . Petersen" Cc: Christoph Hellwig , Hannes Reinecke , Linux Kernel Mailinglist , Linux SCSI Mailinglist , Johannes Thumshirn , "James E.J. Bottomley" Subject: [PATCH v2 08/16] scsi: fc: implement kref backed reference counting Date: Wed, 12 Oct 2016 15:06:34 +0200 Message-Id: <60854e8cdb8b2306d403973ff3759e3650e7d0de.1476276823.git.jthumshirn@suse.de> X-Mailer: git-send-email 1.8.5.6 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3925 Lines: 125 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: Johannes Thumshirn --- drivers/scsi/scsi_transport_fc.c | 38 +++++++++----------------------------- include/scsi/scsi_transport_fc.h | 4 +--- 2 files changed, 10 insertions(+), 32 deletions(-) diff --git a/drivers/scsi/scsi_transport_fc.c b/drivers/scsi/scsi_transport_fc.c index 96b3a2e..b0e28af 100644 --- a/drivers/scsi/scsi_transport_fc.c +++ b/drivers/scsi/scsi_transport_fc.c @@ -3560,16 +3560,9 @@ 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; - - 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); + struct fc_bsg_job *job = container_of(kref, struct fc_bsg_job, kref); put_device(job->dev); /* release reference for the request */ @@ -3620,15 +3613,9 @@ 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 +3629,18 @@ 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 +3648,7 @@ 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; @@ -3730,7 +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); bsg_request = (struct fc_bsg_request *)req->cmd; job->request_len = req->cmd_len; bsg_reply = req->sense; @@ -3752,7 +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; diff --git a/include/scsi/scsi_transport_fc.h b/include/scsi/scsi_transport_fc.h index 9f53fe3..8ae5680 100644 --- a/include/scsi/scsi_transport_fc.h +++ b/include/scsi/scsi_transport_fc.h @@ -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; -- 1.8.5.6