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* [PATCH 0/4] some improvements and clean-up for block
@ 2020-09-18  1:47 Yufen Yu
  2020-09-18  1:47 ` [PATCH 1/4] block: invoke blk_mq_exit_sched no matter whether have .exit_sched Yufen Yu
                   ` (4 more replies)
  0 siblings, 5 replies; 6+ messages in thread
From: Yufen Yu @ 2020-09-18  1:47 UTC (permalink / raw)
  To: axboe; +Cc: linux-block, ming.lei, hch, yuyufen

Hi all,

  This series contains improvement for elevator exit, removing
  wrong comments and clean-up code.

Yufen Yu (4):
  block: invoke blk_mq_exit_sched no matter whether have .exit_sched
  block: use common interface blk_queue_registered()
  block: fix comment and add lockdep assert
  block: get rid of unnecessary local variable

 block/blk-iocost.c |  2 +-
 block/blk-sysfs.c  |  5 +----
 block/elevator.c   | 19 ++++++-------------
 3 files changed, 8 insertions(+), 18 deletions(-)

-- 
2.25.4


^ permalink raw reply	[flat|nested] 6+ messages in thread
* [PATCH 1/4] block: invoke blk_mq_exit_sched no matter whether have .exit_sched
  2020-09-18  1:47 [PATCH 0/4] some improvements and clean-up for block Yufen Yu
@ 2020-09-18  1:47 ` Yufen Yu
  2020-09-18  1:47 ` [PATCH 2/4] block: use common interface blk_queue_registered() Yufen Yu
                   ` (3 subsequent siblings)
  4 siblings, 0 replies; 6+ messages in thread
From: Yufen Yu @ 2020-09-18  1:47 UTC (permalink / raw)
  To: axboe; +Cc: linux-block, ming.lei, hch, yuyufen

We will register debugfs for scheduler no matter whether it have
defined callback funciton .exit_sched. So, blk_mq_exit_sched()
is always needed to unregister debugfs. Also, q->elevator should
be set as NULL after exiting scheduler.

For now, since all register scheduler have defined .exit_sched,
it will not cause any actual problem. But It will be more reasonable
to do this change.

Signed-off-by: Yufen Yu <yuyufen@huawei.com>
---
 block/blk-sysfs.c | 1 -
 block/elevator.c  | 3 +--
 2 files changed, 1 insertion(+), 3 deletions(-)

diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 7dda709f3ccb..ee2cd4d1054c 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -883,7 +883,6 @@ static void blk_exit_queue(struct request_queue *q)
 	if (q->elevator) {
 		ioc_clear_queue(q);
 		__elevator_exit(q, q->elevator);
-		q->elevator = NULL;
 	}
 
 	/*
diff --git a/block/elevator.c b/block/elevator.c
index 6e775bd4af66..b506895b34c7 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -191,8 +191,7 @@ static void elevator_release(struct kobject *kobj)
 void __elevator_exit(struct request_queue *q, struct elevator_queue *e)
 {
 	mutex_lock(&e->sysfs_lock);
-	if (e->type->ops.exit_sched)
-		blk_mq_exit_sched(q, e);
+	blk_mq_exit_sched(q, e);
 	mutex_unlock(&e->sysfs_lock);
 
 	kobject_put(&e->kobj);
-- 
2.25.4


^ permalink raw reply related	[flat|nested] 6+ messages in thread
* [PATCH 2/4] block: use common interface blk_queue_registered()
  2020-09-18  1:47 [PATCH 0/4] some improvements and clean-up for block Yufen Yu
  2020-09-18  1:47 ` [PATCH 1/4] block: invoke blk_mq_exit_sched no matter whether have .exit_sched Yufen Yu
@ 2020-09-18  1:47 ` Yufen Yu
  2020-09-18  1:47 ` [PATCH 3/4] block: fix comment and add lockdep assert Yufen Yu
                   ` (2 subsequent siblings)
  4 siblings, 0 replies; 6+ messages in thread
From: Yufen Yu @ 2020-09-18  1:47 UTC (permalink / raw)
  To: axboe; +Cc: linux-block, ming.lei, hch, yuyufen

We have defined common interface blk_queue_registered() to
test QUEUE_FLAG_REGISTERED. Just use it.

Signed-off-by: Yufen Yu <yuyufen@huawei.com>
---
 block/blk-iocost.c | 2 +-
 block/elevator.c   | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/block/blk-iocost.c b/block/blk-iocost.c
index d37b55db2409..073624f54bc9 100644
--- a/block/blk-iocost.c
+++ b/block/blk-iocost.c
@@ -618,7 +618,7 @@ static struct ioc *q_to_ioc(struct request_queue *q)
 
 static const char *q_name(struct request_queue *q)
 {
-	if (test_bit(QUEUE_FLAG_REGISTERED, &q->queue_flags))
+	if (test_bit(blk_queue_registered(q)))
 		return kobject_name(q->kobj.parent);
 	else
 		return "<unknown>";
diff --git a/block/elevator.c b/block/elevator.c
index b506895b34c7..431a2a1c896e 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -672,7 +672,7 @@ void elevator_init_mq(struct request_queue *q)
 	if (!elv_support_iosched(q))
 		return;
 
-	WARN_ON_ONCE(test_bit(QUEUE_FLAG_REGISTERED, &q->queue_flags));
+	WARN_ON_ONCE(blk_queue_registered(q));
 
 	if (unlikely(q->elevator))
 		return;
-- 
2.25.4


^ permalink raw reply related	[flat|nested] 6+ messages in thread
* [PATCH 3/4] block: fix comment and add lockdep assert
  2020-09-18  1:47 [PATCH 0/4] some improvements and clean-up for block Yufen Yu
  2020-09-18  1:47 ` [PATCH 1/4] block: invoke blk_mq_exit_sched no matter whether have .exit_sched Yufen Yu
  2020-09-18  1:47 ` [PATCH 2/4] block: use common interface blk_queue_registered() Yufen Yu
@ 2020-09-18  1:47 ` Yufen Yu
  2020-09-18  1:47 ` [PATCH 4/4] block: get rid of unnecessary local variable Yufen Yu
  2020-09-18  7:55 ` [PATCH 0/4] some improvements and clean-up for block Yufen Yu
  4 siblings, 0 replies; 6+ messages in thread
From: Yufen Yu @ 2020-09-18  1:47 UTC (permalink / raw)
  To: axboe; +Cc: linux-block, ming.lei, hch, yuyufen

After commit b89f625e28d4 ("block: don't release queue's sysfs
lock during switching elevator"), whole elevator register and
unregister function are covered by sysfs_lock. So, remove wrong
comment and add lockdep assert.

Signed-off-by: Yufen Yu <yuyufen@huawei.com>
---
 block/elevator.c | 14 ++++----------
 1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/block/elevator.c b/block/elevator.c
index 431a2a1c896e..293c5c81397a 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -479,16 +479,13 @@ static struct kobj_type elv_ktype = {
 	.release	= elevator_release,
 };
 
-/*
- * elv_register_queue is called from either blk_register_queue or
- * elevator_switch, elevator switch is prevented from being happen
- * in the two paths, so it is safe to not hold q->sysfs_lock.
- */
 int elv_register_queue(struct request_queue *q, bool uevent)
 {
 	struct elevator_queue *e = q->elevator;
 	int error;
 
+	lockdep_assert_held(&q->sysfs_lock);
+
 	error = kobject_add(&e->kobj, &q->kobj, "%s", "iosched");
 	if (!error) {
 		struct elv_fs_entry *attr = e->type->elevator_attrs;
@@ -507,13 +504,10 @@ int elv_register_queue(struct request_queue *q, bool uevent)
 	return error;
 }
 
-/*
- * elv_unregister_queue is called from either blk_unregister_queue or
- * elevator_switch, elevator switch is prevented from being happen
- * in the two paths, so it is safe to not hold q->sysfs_lock.
- */
 void elv_unregister_queue(struct request_queue *q)
 {
+	lockdep_assert_held(&q->sysfs_lock);
+
 	if (q) {
 		struct elevator_queue *e = q->elevator;
 
-- 
2.25.4


^ permalink raw reply related	[flat|nested] 6+ messages in thread
* [PATCH 4/4] block: get rid of unnecessary local variable
  2020-09-18  1:47 [PATCH 0/4] some improvements and clean-up for block Yufen Yu
                   ` (2 preceding siblings ...)
  2020-09-18  1:47 ` [PATCH 3/4] block: fix comment and add lockdep assert Yufen Yu
@ 2020-09-18  1:47 ` Yufen Yu
  2020-09-18  7:55 ` [PATCH 0/4] some improvements and clean-up for block Yufen Yu
  4 siblings, 0 replies; 6+ messages in thread
From: Yufen Yu @ 2020-09-18  1:47 UTC (permalink / raw)
  To: axboe; +Cc: linux-block, ming.lei, hch, yuyufen

Since whole elevator register is protectd by sysfs_lock, we
don't need extras 'has_elevator'. Just use q->elevator directly.

Signed-off-by: Yufen Yu <yuyufen@huawei.com>
---
 block/blk-sysfs.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index ee2cd4d1054c..d13a70ed39bf 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -976,7 +976,6 @@ int blk_register_queue(struct gendisk *disk)
 	int ret;
 	struct device *dev = disk_to_dev(disk);
 	struct request_queue *q = disk->queue;
-	bool has_elevator = false;
 
 	if (WARN_ON(!q))
 		return -ENXIO;
@@ -1040,7 +1039,6 @@ int blk_register_queue(struct gendisk *disk)
 			kobject_put(&dev->kobj);
 			return ret;
 		}
-		has_elevator = true;
 	}
 
 	blk_queue_flag_set(QUEUE_FLAG_REGISTERED, q);
@@ -1049,7 +1047,7 @@ int blk_register_queue(struct gendisk *disk)
 
 	/* Now everything is ready and send out KOBJ_ADD uevent */
 	kobject_uevent(&q->kobj, KOBJ_ADD);
-	if (has_elevator)
+	if (q->elevator)
 		kobject_uevent(&q->elevator->kobj, KOBJ_ADD);
 	mutex_unlock(&q->sysfs_lock);
 
-- 
2.25.4


^ permalink raw reply related	[flat|nested] 6+ messages in thread
* Re: [PATCH 0/4] some improvements and clean-up for block
  2020-09-18  1:47 [PATCH 0/4] some improvements and clean-up for block Yufen Yu
                   ` (3 preceding siblings ...)
  2020-09-18  1:47 ` [PATCH 4/4] block: get rid of unnecessary local variable Yufen Yu
@ 2020-09-18  7:55 ` Yufen Yu
  4 siblings, 0 replies; 6+ messages in thread
From: Yufen Yu @ 2020-09-18  7:55 UTC (permalink / raw)
  To: axboe; +Cc: linux-block, ming.lei, hch, andy.lavr

Ignoring this patch set. There is a sloppy error in patch 2. I will resend the patch set.
Sorry for noise. Thanks for Andy Lavr to point the error.

On 2020/9/18 9:47, Yufen Yu wrote:
> Hi all,
> 
>    This series contains improvement for elevator exit, removing
>    wrong comments and clean-up code.
> 
> Yufen Yu (4):
>    block: invoke blk_mq_exit_sched no matter whether have .exit_sched
>    block: use common interface blk_queue_registered()
>    block: fix comment and add lockdep assert
>    block: get rid of unnecessary local variable
> 
>   block/blk-iocost.c |  2 +-
>   block/blk-sysfs.c  |  5 +----
>   block/elevator.c   | 19 ++++++-------------
>   3 files changed, 8 insertions(+), 18 deletions(-)
> 

^ permalink raw reply	[flat|nested] 6+ messages in thread
end of thread, other threads:[~2020-09-18  7:56 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2020-09-18  1:47 [PATCH 0/4] some improvements and clean-up for block Yufen Yu
2020-09-18  1:47 ` [PATCH 1/4] block: invoke blk_mq_exit_sched no matter whether have .exit_sched Yufen Yu
2020-09-18  1:47 ` [PATCH 2/4] block: use common interface blk_queue_registered() Yufen Yu
2020-09-18  1:47 ` [PATCH 3/4] block: fix comment and add lockdep assert Yufen Yu
2020-09-18  1:47 ` [PATCH 4/4] block: get rid of unnecessary local variable Yufen Yu
2020-09-18  7:55 ` [PATCH 0/4] some improvements and clean-up for block Yufen Yu

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