[PATCH V4 3/7] loop: conver timer for monitoring idle worker into dwork

Ming Lei
2021-08-06T08:04:04Z

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.

Acked-by: Dan Schatzberg <schatzberg.dan@gmail.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
drivers/block/loop.c | 75 ++++++++++++++++++++++----------------------
drivers/block/loop.h | 2 +-
2 files changed, 38 insertions(+), 39 deletions(-)

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 0df2a6add598..6e65e46553f6 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -982,7 +982,6 @@ 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)
@@ -1026,7 +1025,7 @@ static void loop_queue_work(struct loop_device *lo, struct loop_cmd *cmd)
struct list_head *cmd_list;
struct cgroup_subsys_state *blkcg_css = loop_rq_blkcg_css(cmd);

- spin_lock_irq(&lo->lo_work_lock);
+ spin_lock(&lo->lo_work_lock);

if (queue_on_root_worker(blkcg_css))
goto queue_work;
@@ -1081,7 +1080,7 @@ 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)
@@ -1203,6 +1202,33 @@ 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)
@@ -1283,8 +1309,7 @@ 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;
@@ -1384,7 +1409,7 @@ 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);
@@ -1392,8 +1417,8 @@ 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;
@@ -2211,11 +2236,6 @@ 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)
{
@@ -2223,17 +2243,17 @@ 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);
}

/*
@@ -2246,7 +2266,7 @@ 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;
}

@@ -2278,27 +2298,6 @@ 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