[PATCH] dm: Check kthread_run's return value

From: Minfei Huang
Date: Tue Jun 21 2016 - 23:36:31 EST


kthread function is used to process kthread_work. And there is no return
value checking during create this thread. Add this checking to fix this
issue.

Signed-off-by: Minfei Huang <mnghuan@xxxxxxxxx>
Signed-off-by: Minfei Huang <minfei.hmf@xxxxxxxxxxxxxxx>
---
drivers/md/dm.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 1b2f962..d68b9d2 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -2654,12 +2654,15 @@ struct queue_limits *dm_get_queue_limits(struct mapped_device *md)
}
EXPORT_SYMBOL_GPL(dm_get_queue_limits);

-static void dm_old_init_rq_based_worker_thread(struct mapped_device *md)
+static int dm_old_init_rq_based_worker_thread(struct mapped_device *md)
{
/* Initialize the request-based DM worker thread */
init_kthread_worker(&md->kworker);
md->kworker_task = kthread_run(kthread_worker_fn, &md->kworker,
"kdmwork-%s", dm_device_name(md));
+ if (IS_ERR(md->kworker_task))
+ return -ENOMEM;
+ return 0;
}

/*
@@ -2667,6 +2670,8 @@ static void dm_old_init_rq_based_worker_thread(struct mapped_device *md)
*/
static int dm_old_init_request_queue(struct mapped_device *md)
{
+ int ret;
+
/* Fully initialize the queue */
if (!blk_init_allocated_queue(md->queue, dm_request_fn, NULL))
return -EINVAL;
@@ -2678,7 +2683,9 @@ static int dm_old_init_request_queue(struct mapped_device *md)
blk_queue_softirq_done(md->queue, dm_softirq_done);
blk_queue_prep_rq(md->queue, dm_old_prep_fn);

- dm_old_init_rq_based_worker_thread(md);
+ ret = dm_old_init_rq_based_worker_thread(md);
+ if (ret < 0)
+ return ret;

elv_register_queue(md->queue);

--
2.7.4 (Apple Git-66)