[PATCH 2/6] loop: conver timer for monitoring idle worker into dwork

[Ming Lei <ming.lei@redhat.com>]

Not necessary to use a timer to do that, and dwork is just fine,
then we don't need to always disable interrupt when acquiring
->loop_work_lock.

Cc: Michal Koutný <mkoutny@suse.com>
Cc: Dan Schatzberg <schatzberg.dan@gmail.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
 drivers/block/loop.c | 76 ++++++++++++++++++++++----------------------
 drivers/block/loop.h |  2 +-
 2 files changed, 39 insertions(+), 39 deletions(-)

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 8378b8455f7c..7fa0c70a3ea6 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -929,7 +929,6 @@ struct loop_worker {
 
 static void loop_workfn(struct work_struct *work);
 static void loop_rootcg_workfn(struct work_struct *work);
-static void loop_free_idle_workers(struct timer_list *timer);
 
 #ifdef CONFIG_BLK_CGROUP
 static inline int queue_on_root_worker(struct cgroup_subsys_state *css)
@@ -957,7 +956,7 @@ static void loop_queue_work(struct loop_device *lo, struct loop_cmd *cmd)
 		blkcg_css = &bio_blkcg(rq->bio)->css;
 #endif
 
-	spin_lock_irq(&lo->lo_work_lock);
+	spin_lock(&lo->lo_work_lock);
 
 	if (queue_on_root_worker(blkcg_css))
 		goto queue_work;
@@ -1012,7 +1011,7 @@ static void loop_queue_work(struct loop_device *lo, struct loop_cmd *cmd)
 	}
 	list_add_tail(&cmd->list_entry, cmd_list);
 	queue_work(lo->workqueue, work);
-	spin_unlock_irq(&lo->lo_work_lock);
+	spin_unlock(&lo->lo_work_lock);
 }
 
 static void loop_update_rotational(struct loop_device *lo)
@@ -1134,6 +1133,34 @@ loop_set_status_from_info(struct loop_device *lo,
 	return 0;
 }
 
+static void loop_set_timer(struct loop_device *lo)
+{
+	schedule_delayed_work(&lo->idle_work, LOOP_IDLE_WORKER_TIMEOUT);
+}
+
+static void loop_free_idle_workers(struct work_struct *work)
+{
+	struct loop_device *lo = container_of(work, struct loop_device,
+			idle_work.work);
+	struct loop_worker *pos, *worker;
+
+	spin_lock(&lo->lo_work_lock);
+	list_for_each_entry_safe(worker, pos, &lo->idle_worker_list,
+				idle_list) {
+		if (time_is_after_jiffies(worker->last_ran_at +
+						LOOP_IDLE_WORKER_TIMEOUT))
+			break;
+		list_del(&worker->idle_list);
+		rb_erase(&worker->rb_node, &lo->worker_tree);
+		css_put(worker->blkcg_css);
+		kfree(worker);
+	}
+	if (!list_empty(&lo->idle_worker_list))
+		loop_set_timer(lo);
+	spin_unlock(&lo->lo_work_lock);
+}
+
+
 static int loop_configure(struct loop_device *lo, fmode_t mode,
 			  struct block_device *bdev,
 			  const struct loop_config *config)
@@ -1213,8 +1240,7 @@ static int loop_configure(struct loop_device *lo, fmode_t mode,
 	INIT_LIST_HEAD(&lo->rootcg_cmd_list);
 	INIT_LIST_HEAD(&lo->idle_worker_list);
 	lo->worker_tree = RB_ROOT;
-	timer_setup(&lo->timer, loop_free_idle_workers,
-		TIMER_DEFERRABLE);
+	INIT_DELAYED_WORK(&lo->idle_work, loop_free_idle_workers);
 	lo->use_dio = lo->lo_flags & LO_FLAGS_DIRECT_IO;
 	lo->lo_device = bdev;
 	lo->lo_backing_file = file;
@@ -1304,7 +1330,7 @@ static int __loop_clr_fd(struct loop_device *lo, bool release)
 	blk_mq_freeze_queue(lo->lo_queue);
 
 	destroy_workqueue(lo->workqueue);
-	spin_lock_irq(&lo->lo_work_lock);
+	spin_lock(&lo->lo_work_lock);
 	list_for_each_entry_safe(worker, pos, &lo->idle_worker_list,
 				idle_list) {
 		list_del(&worker->idle_list);
@@ -1312,8 +1338,8 @@ static int __loop_clr_fd(struct loop_device *lo, bool release)
 		css_put(worker->blkcg_css);
 		kfree(worker);
 	}
-	spin_unlock_irq(&lo->lo_work_lock);
-	del_timer_sync(&lo->timer);
+	spin_unlock(&lo->lo_work_lock);
+	cancel_delayed_work_sync(&lo->idle_work);
 
 	spin_lock_irq(&lo->lo_lock);
 	lo->lo_backing_file = NULL;
@@ -2133,11 +2159,6 @@ static void loop_handle_cmd(struct loop_cmd *cmd)
 	}
 }
 
-static void loop_set_timer(struct loop_device *lo)
-{
-	timer_reduce(&lo->timer, jiffies + LOOP_IDLE_WORKER_TIMEOUT);
-}
-
 static void loop_process_work(struct loop_worker *worker,
 			struct list_head *cmd_list, struct loop_device *lo)
 {
@@ -2145,17 +2166,17 @@ static void loop_process_work(struct loop_worker *worker,
 	struct loop_cmd *cmd;
 
 	current->flags |= PF_LOCAL_THROTTLE | PF_MEMALLOC_NOIO;
-	spin_lock_irq(&lo->lo_work_lock);
+	spin_lock(&lo->lo_work_lock);
 	while (!list_empty(cmd_list)) {
 		cmd = container_of(
 			cmd_list->next, struct loop_cmd, list_entry);
 		list_del(cmd_list->next);
-		spin_unlock_irq(&lo->lo_work_lock);
+		spin_unlock(&lo->lo_work_lock);
 
 		loop_handle_cmd(cmd);
 		cond_resched();
 
-		spin_lock_irq(&lo->lo_work_lock);
+		spin_lock(&lo->lo_work_lock);
 	}
 
 	/*
@@ -2168,7 +2189,7 @@ static void loop_process_work(struct loop_worker *worker,
 		list_add_tail(&worker->idle_list, &lo->idle_worker_list);
 		loop_set_timer(lo);
 	}
-	spin_unlock_irq(&lo->lo_work_lock);
+	spin_unlock(&lo->lo_work_lock);
 	current->flags = orig_flags;
 }
 
@@ -2204,27 +2225,6 @@ static void loop_rootcg_workfn(struct work_struct *work)
 	loop_process_work(NULL, &lo->rootcg_cmd_list, lo);
 }
 
-static void loop_free_idle_workers(struct timer_list *timer)
-{
-	struct loop_device *lo = container_of(timer, struct loop_device, timer);
-	struct loop_worker *pos, *worker;
-
-	spin_lock_irq(&lo->lo_work_lock);
-	list_for_each_entry_safe(worker, pos, &lo->idle_worker_list,
-				idle_list) {
-		if (time_is_after_jiffies(worker->last_ran_at +
-						LOOP_IDLE_WORKER_TIMEOUT))
-			break;
-		list_del(&worker->idle_list);
-		rb_erase(&worker->rb_node, &lo->worker_tree);
-		css_put(worker->blkcg_css);
-		kfree(worker);
-	}
-	if (!list_empty(&lo->idle_worker_list))
-		loop_set_timer(lo);
-	spin_unlock_irq(&lo->lo_work_lock);
-}
-
 static const struct blk_mq_ops loop_mq_ops = {
 	.queue_rq       = loop_queue_rq,
 	.complete	= lo_complete_rq,
diff --git a/drivers/block/loop.h b/drivers/block/loop.h
index a52a3fd89457..9df889af1bcf 100644
--- a/drivers/block/loop.h
+++ b/drivers/block/loop.h
@@ -60,7 +60,7 @@ struct loop_device {
 	struct list_head        rootcg_cmd_list;
 	struct list_head        idle_worker_list;
 	struct rb_root          worker_tree;
-	struct timer_list       timer;
+	struct delayed_work	idle_work;
 	bool			use_dio;
 	bool			sysfs_inited;
 
-- 
2.31.1