[PATCH v3 09/16] block: add reference counting for struct bsg_job

From: Johannes Thumshirn
Date: Thu Oct 13 2016 - 11:04:49 EST


Add reference counting to 'struct bsg_job' so we can implement a reuqest
timeout handler for bsg_jobs, which is needed for Fibre Channel.

Signed-off-by: Johannes Thumshirn <jthumshirn@xxxxxxx>
Reviewed-by: Hannes Reinecke <hare@xxxxxxxx>
---
block/bsg-lib.c | 7 +++++--
include/linux/bsg-lib.h | 2 ++
2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/block/bsg-lib.c b/block/bsg-lib.c
index 650f427..632fb40 100644
--- a/block/bsg-lib.c
+++ b/block/bsg-lib.c
@@ -32,8 +32,10 @@
* bsg_destroy_job - routine to teardown/delete a bsg job
* @job: bsg_job that is to be torn down
*/
-static void bsg_destroy_job(struct bsg_job *job)
+static void bsg_destroy_job(struct kref *kref)
{
+ struct bsg_job *job = container_of(kref, struct bsg_job, kref);
+
put_device(job->dev); /* release reference for the request */

kfree(job->request_payload.sg_list);
@@ -84,7 +86,7 @@ static void bsg_softirq_done(struct request *rq)
struct bsg_job *job = rq->special;

blk_end_request_all(rq, rq->errors);
- bsg_destroy_job(job);
+ kref_put(&job->kref, bsg_destroy_job);
}

static int bsg_map_buffer(struct bsg_buffer *buf, struct request *req)
@@ -142,6 +144,7 @@ static int bsg_create_job(struct device *dev, struct request *req)
job->dev = dev;
/* take a reference for the request */
get_device(job->dev);
+ kref_init(&job->kref);
return 0;

failjob_rls_rqst_payload:
diff --git a/include/linux/bsg-lib.h b/include/linux/bsg-lib.h
index a226652..58e0717 100644
--- a/include/linux/bsg-lib.h
+++ b/include/linux/bsg-lib.h
@@ -40,6 +40,8 @@ struct bsg_job {
struct device *dev;
struct request *req;

+ struct kref kref;
+
/* Transport/driver specific request/reply structs */
void *request;
void *reply;
--
1.8.5.6