Re: [RFC][PATCH v2 04/31] timers: block: Use del_timer_shutdown() before freeing timer

[Guenter Roeck <linux@xxxxxxxxxxxx>]

On 10/27/22 08:05, Steven Rostedt wrote:
> From: "Steven Rostedt (Google)" <rostedt@xxxxxxxxxxx>
>
> Before a timer is freed, del_timer_shutdown() must be called.

I also had to add the following, as you had already suggested.

Just changing blk_sync_queue() was insufficient; I had to add the call from
blk_release_queue() because otherwise blk_sync_queue() was not always called.

Thanks,
Guenter

---
diff --git a/block/blk-core.c b/block/blk-core.c
index 17667159482e..69b1daa2e91a 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -227,7 +227,7 @@ const char *blk_status_to_str(blk_status_t status)
  */
 void blk_sync_queue(struct request_queue *q)
 {
-       del_timer_sync(&q->timeout);
+       del_timer_shutdown(&q->timeout);
        cancel_work_sync(&q->timeout_work);
 }
 EXPORT_SYMBOL(blk_sync_queue);
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index e71b3b43927c..12a1e46536ed 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -769,6 +769,8 @@ static void blk_release_queue(struct kobject *kobj)

        percpu_ref_exit(&q->q_usage_counter);

+       blk_sync_queue(q);
+
        if (q->poll_stat)
                blk_stat_remove_callback(q, q->poll_cb);
        blk_stat_free_callback(q->poll_cb);