switch blk-cgroup to work on gendisk

switch blk-cgroup to work on gendisk

[Christoph Hellwig]

Hi all,

blk-cgroup works on only on live disks and "file system" I/O from bios.
This all the information should be in the gendisk, and not the
request_queue that also exists for pure passthrough request based
devices.

Diffstat:
 block/bfq-cgroup.c        |   18 ++--
 block/bfq-iosched.c       |    6 -
 block/blk-cgroup-rwstat.c |    2 
 block/blk-cgroup.c        |  185 +++++++++++++++++++++-------------------------
 block/blk-cgroup.h        |   41 ++++------
 block/blk-iocost.c        |   40 ++++-----
 block/blk-iolatency.c     |   41 ++++------
 block/blk-ioprio.c        |    6 -
 block/blk-mq-debugfs.c    |   10 --
 block/blk-rq-qos.c        |   67 ++++++++++++++++
 block/blk-rq-qos.h        |   66 +---------------
 block/blk-stat.c          |    3 
 block/blk-sysfs.c         |    4 
 block/blk-throttle.c      |   31 ++++---
 block/blk-wbt.c           |   39 ++++-----
 block/blk-wbt.h           |   12 +-
 block/genhd.c             |   17 ++--
 include/linux/blkdev.h    |   10 +-
 include/linux/sched.h     |    2 
 kernel/fork.c             |    2 
 mm/swapfile.c             |    2 
 21 files changed, 292 insertions(+), 312 deletions(-)

[PATCH 01/15] blk-cgroup: don't defer blkg_free to a workqueue

[Christoph Hellwig]

Now that blk_put_queue can be called from process context, ther is no
need for the asynchronous execution.

This effectively reverts commit d578c770c85233af592e54537f93f3831bde7e9a.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-cgroup.c | 32 ++++++++++----------------------
 block/blk-cgroup.h |  5 +----
 2 files changed, 11 insertions(+), 26 deletions(-)

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index ce6a2b7d3dfb2b..30d493b43f9272 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -114,12 +114,19 @@ static bool blkcg_policy_enabled(struct request_queue *q,
 	return pol && test_bit(pol->plid, q->blkcg_pols);
 }
 
-static void blkg_free_workfn(struct work_struct *work)
+/**
+ * blkg_free - free a blkg
+ * @blkg: blkg to free
+ *
+ * Free @blkg which may be partially allocated.
+ */
+static void blkg_free(struct blkcg_gq *blkg)
 {
-	struct blkcg_gq *blkg = container_of(work, struct blkcg_gq,
-					     free_work);
 	int i;
 
+	if (!blkg)
+		return;
+
 	for (i = 0; i < BLKCG_MAX_POLS; i++)
 		if (blkg->pd[i])
 			blkcg_policy[i]->pd_free_fn(blkg->pd[i]);
@@ -131,25 +138,6 @@ static void blkg_free_workfn(struct work_struct *work)
 	kfree(blkg);
 }
 
-/**
- * blkg_free - free a blkg
- * @blkg: blkg to free
- *
- * Free @blkg which may be partially allocated.
- */
-static void blkg_free(struct blkcg_gq *blkg)
-{
-	if (!blkg)
-		return;
-
-	/*
-	 * Both ->pd_free_fn() and request queue's release handler may
-	 * sleep, so free us by scheduling one work func
-	 */
-	INIT_WORK(&blkg->free_work, blkg_free_workfn);
-	schedule_work(&blkg->free_work);
-}
-
 static void __blkg_release(struct rcu_head *rcu)
 {
 	struct blkcg_gq *blkg = container_of(rcu, struct blkcg_gq, rcu_head);
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index 1e94e404eaa80a..f126fe36001eb3 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -75,10 +75,7 @@ struct blkcg_gq {
 
 	spinlock_t			async_bio_lock;
 	struct bio_list			async_bios;
-	union {
-		struct work_struct	async_bio_work;
-		struct work_struct	free_work;
-	};
+	struct work_struct		async_bio_work;
 
 	atomic_t			use_delay;
 	atomic64_t			delay_nsec;
-- 
2.39.0

Re: [PATCH 01/15] blk-cgroup: don't defer blkg_free to a workqueue

[Andreas Herrmann]

On Tue, Jan 17, 2023 at 09:12:43AM +0100, Christoph Hellwig wrote:
> Now that blk_put_queue can be called from process context, ther is no
                                                             ^^^^
							     there
> need for the asynchronous execution.
> 
> This effectively reverts commit d578c770c85233af592e54537f93f3831bde7e9a.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  block/blk-cgroup.c | 32 ++++++++++----------------------
>  block/blk-cgroup.h |  5 +----
>  2 files changed, 11 insertions(+), 26 deletions(-)

Looks good to me. Feel free to add
Reviewed-by: Andreas Herrmann <aherrmann@suse.de>

> diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
> index ce6a2b7d3dfb2b..30d493b43f9272 100644
> --- a/block/blk-cgroup.c
> +++ b/block/blk-cgroup.c
> @@ -114,12 +114,19 @@ static bool blkcg_policy_enabled(struct request_queue *q,
>  	return pol && test_bit(pol->plid, q->blkcg_pols);
>  }
>  
> -static void blkg_free_workfn(struct work_struct *work)
> +/**
> + * blkg_free - free a blkg
> + * @blkg: blkg to free
> + *
> + * Free @blkg which may be partially allocated.
> + */
> +static void blkg_free(struct blkcg_gq *blkg)
>  {
> -	struct blkcg_gq *blkg = container_of(work, struct blkcg_gq,
> -					     free_work);
>  	int i;
>  
> +	if (!blkg)
> +		return;
> +
>  	for (i = 0; i < BLKCG_MAX_POLS; i++)
>  		if (blkg->pd[i])
>  			blkcg_policy[i]->pd_free_fn(blkg->pd[i]);
> @@ -131,25 +138,6 @@ static void blkg_free_workfn(struct work_struct *work)
>  	kfree(blkg);
>  }
>  
> -/**
> - * blkg_free - free a blkg
> - * @blkg: blkg to free
> - *
> - * Free @blkg which may be partially allocated.
> - */
> -static void blkg_free(struct blkcg_gq *blkg)
> -{
> -	if (!blkg)
> -		return;
> -
> -	/*
> -	 * Both ->pd_free_fn() and request queue's release handler may
> -	 * sleep, so free us by scheduling one work func
> -	 */
> -	INIT_WORK(&blkg->free_work, blkg_free_workfn);
> -	schedule_work(&blkg->free_work);
> -}
> -
>  static void __blkg_release(struct rcu_head *rcu)
>  {
>  	struct blkcg_gq *blkg = container_of(rcu, struct blkcg_gq, rcu_head);
> diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
> index 1e94e404eaa80a..f126fe36001eb3 100644
> --- a/block/blk-cgroup.h
> +++ b/block/blk-cgroup.h
> @@ -75,10 +75,7 @@ struct blkcg_gq {
>  
>  	spinlock_t			async_bio_lock;
>  	struct bio_list			async_bios;
> -	union {
> -		struct work_struct	async_bio_work;
> -		struct work_struct	free_work;
> -	};
> +	struct work_struct		async_bio_work;
>  
>  	atomic_t			use_delay;
>  	atomic64_t			delay_nsec;
> -- 
> 2.39.0
> 

-- 
Regards,
Andreas

SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nürnberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Martje Boudien Moerman
(HRB 36809, AG Nürnberg)

Re: [PATCH 01/15] blk-cgroup: don't defer blkg_free to a workqueue

[Hannes Reinecke]

On 1/17/23 09:12, Christoph Hellwig wrote:
> Now that blk_put_queue can be called from process context, ther is no
> need for the asynchronous execution.
> 
Can you clarify 'now'?
IE point to the commit introducing the change?

> This effectively reverts commit d578c770c85233af592e54537f93f3831bde7e9a.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>   block/blk-cgroup.c | 32 ++++++++++----------------------
>   block/blk-cgroup.h |  5 +----
>   2 files changed, 11 insertions(+), 26 deletions(-)
> 
Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare@suse.de                              +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew
Myers, Andrew McDonald, Martje Boudien Moerman

Re: [PATCH 01/15] blk-cgroup: don't defer blkg_free to a workqueue

[Christoph Hellwig]

On Fri, Jan 27, 2023 at 07:59:23AM +0100, Hannes Reinecke wrote:
> On 1/17/23 09:12, Christoph Hellwig wrote:
>> Now that blk_put_queue can be called from process context, ther is no
>> need for the asynchronous execution.
>>
> Can you clarify 'now'?
> IE point to the commit introducing the change?

49e4d04f0486117ac57a97890eb1db6d52bf82b3
Author: Tejun Heo <tj@kernel.org>
Date:   Fri Jan 6 10:34:10 2023 -1000

    block: Drop spurious might_sleep() from blk_put_queue()

Re: [PATCH 01/15] blk-cgroup: don't defer blkg_free to a workqueue

[Hannes Reinecke]

On 1/27/23 08:07, Christoph Hellwig wrote:
> On Fri, Jan 27, 2023 at 07:59:23AM +0100, Hannes Reinecke wrote:
>> On 1/17/23 09:12, Christoph Hellwig wrote:
>>> Now that blk_put_queue can be called from process context, ther is no
>>> need for the asynchronous execution.
>>>
>> Can you clarify 'now'?
>> IE point to the commit introducing the change?
> 
> 49e4d04f0486117ac57a97890eb1db6d52bf82b3
> Author: Tejun Heo <tj@kernel.org>
> Date:   Fri Jan 6 10:34:10 2023 -1000
> 
>      block: Drop spurious might_sleep() from blk_put_queue()
> 
Can we please have it in the patch comment?
To clarify that this is a pre-requisite for this patch?

Thanks.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare@suse.de                              +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew
Myers, Andrew McDonald, Martje Boudien Moerman

[PATCH 02/15] block: don't call blk_throtl_stat_add for non-READ/WRITE commands

[Christoph Hellwig]

blk_throtl_stat_add is called from blk_stat_add explicitly, unlike the
other stats that go through q->stats->callbacks.  To prepare for cgroup
data moving to the gendisk, ensure blk_throtl_stat_add is only called
for the plain READ and WRITE commands that it actually handles internally,
as blk_stat_add can also be called for passthrough commands on queues that
do not have a genisk associated with them.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-stat.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/block/blk-stat.c b/block/blk-stat.c
index 2ea01b5c1aca04..c6ca16abf911e2 100644
--- a/block/blk-stat.c
+++ b/block/blk-stat.c
@@ -58,7 +58,8 @@ void blk_stat_add(struct request *rq, u64 now)
 
 	value = (now >= rq->io_start_time_ns) ? now - rq->io_start_time_ns : 0;
 
-	blk_throtl_stat_add(rq, value);
+	if (req_op(rq) == REQ_OP_READ || req_op(rq) == REQ_OP_WRITE)
+		blk_throtl_stat_add(rq, value);
 
 	rcu_read_lock();
 	cpu = get_cpu();
-- 
2.39.0

Re: [PATCH 02/15] block: don't call blk_throtl_stat_add for non-READ/WRITE commands

[Andreas Herrmann]

On Tue, Jan 17, 2023 at 09:12:44AM +0100, Christoph Hellwig wrote:
> blk_throtl_stat_add is called from blk_stat_add explicitly, unlike the
> other stats that go through q->stats->callbacks.  To prepare for cgroup
> data moving to the gendisk, ensure blk_throtl_stat_add is only called
> for the plain READ and WRITE commands that it actually handles internally,
> as blk_stat_add can also be called for passthrough commands on queues that
> do not have a genisk associated with them.
                ^^^^^^
		gendisk
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  block/blk-stat.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)

Looks good to me. Feel free to add
Reviewed-by: Andreas Herrmann <aherrmann@suse.de>

> diff --git a/block/blk-stat.c b/block/blk-stat.c
> index 2ea01b5c1aca04..c6ca16abf911e2 100644
> --- a/block/blk-stat.c
> +++ b/block/blk-stat.c
> @@ -58,7 +58,8 @@ void blk_stat_add(struct request *rq, u64 now)
>  
>  	value = (now >= rq->io_start_time_ns) ? now - rq->io_start_time_ns : 0;
>  
> -	blk_throtl_stat_add(rq, value);
> +	if (req_op(rq) == REQ_OP_READ || req_op(rq) == REQ_OP_WRITE)
> +		blk_throtl_stat_add(rq, value);
>  
>  	rcu_read_lock();
>  	cpu = get_cpu();
> -- 
> 2.39.0
> 

-- 
Regards,
Andreas

SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nürnberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Martje Boudien Moerman
(HRB 36809, AG Nürnberg)

Re: [PATCH 02/15] block: don't call blk_throtl_stat_add for non-READ/WRITE commands

[Hannes Reinecke]

On 1/17/23 09:12, Christoph Hellwig wrote:
> blk_throtl_stat_add is called from blk_stat_add explicitly, unlike the
> other stats that go through q->stats->callbacks.  To prepare for cgroup
> data moving to the gendisk, ensure blk_throtl_stat_add is only called
> for the plain READ and WRITE commands that it actually handles internally,
> as blk_stat_add can also be called for passthrough commands on queues that
> do not have a genisk associated with them.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>   block/blk-stat.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
> 
Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare@suse.de                              +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew
Myers, Andrew McDonald, Martje Boudien Moerman

[PATCH 03/15] blk-cgroup: delay blk-cgroup initialization until add_disk

[Christoph Hellwig]

There is no need to initialize the group code before the disk is marked
live.  Moving the cgroup initialization earlier will help to have a
fully initialized struct device in the gendisk for the cgroup code to
use in the future.  Similarly tear the cgroup information down in
del_gendisk to be symmetric and because none of the cgroup tracking is
needed once non-passthrough I/O stops.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/genhd.c | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/block/genhd.c b/block/genhd.c
index 23cf83b3331cde..705dec0800d62e 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -466,10 +466,14 @@ int __must_check device_add_disk(struct device *parent, struct gendisk *disk,
 	 */
 	pm_runtime_set_memalloc_noio(ddev, true);
 
-	ret = blk_integrity_add(disk);
+	ret = blkcg_init_disk(disk);
 	if (ret)
 		goto out_del_block_link;
 
+	ret = blk_integrity_add(disk);
+	if (ret)
+		goto out_blkcg_exit;
+
 	disk->part0->bd_holder_dir =
 		kobject_create_and_add("holders", &ddev->kobj);
 	if (!disk->part0->bd_holder_dir) {
@@ -534,6 +538,8 @@ int __must_check device_add_disk(struct device *parent, struct gendisk *disk,
 	kobject_put(disk->part0->bd_holder_dir);
 out_del_integrity:
 	blk_integrity_del(disk);
+out_blkcg_exit:
+	blkcg_exit_disk(disk);
 out_del_block_link:
 	if (!sysfs_deprecated)
 		sysfs_remove_link(block_depr, dev_name(ddev));
@@ -662,6 +668,8 @@ void del_gendisk(struct gendisk *disk)
 	rq_qos_exit(q);
 	blk_mq_unquiesce_queue(q);
 
+	blkcg_exit_disk(disk);
+
 	/*
 	 * If the disk does not own the queue, allow using passthrough requests
 	 * again.  Else leave the queue frozen to fail all I/O.
@@ -1171,8 +1179,6 @@ static void disk_release(struct device *dev)
 	    !test_bit(GD_ADDED, &disk->state))
 		blk_mq_exit_queue(disk->queue);
 
-	blkcg_exit_disk(disk);
-
 	bioset_exit(&disk->bio_split);
 
 	disk_release_events(disk);
@@ -1385,9 +1391,6 @@ struct gendisk *__alloc_disk_node(struct request_queue *q, int node_id,
 	if (xa_insert(&disk->part_tbl, 0, disk->part0, GFP_KERNEL))
 		goto out_destroy_part_tbl;
 
-	if (blkcg_init_disk(disk))
-		goto out_erase_part0;
-
 	rand_initialize_disk(disk);
 	disk_to_dev(disk)->class = &block_class;
 	disk_to_dev(disk)->type = &disk_type;
@@ -1400,8 +1403,6 @@ struct gendisk *__alloc_disk_node(struct request_queue *q, int node_id,
 #endif
 	return disk;
 
-out_erase_part0:
-	xa_erase(&disk->part_tbl, 0);
 out_destroy_part_tbl:
 	xa_destroy(&disk->part_tbl);
 	disk->part0->bd_disk = NULL;
-- 
2.39.0

Re: [PATCH 03/15] blk-cgroup: delay blk-cgroup initialization until add_disk

[Andreas Herrmann]

On Tue, Jan 17, 2023 at 09:12:45AM +0100, Christoph Hellwig wrote:
> There is no need to initialize the group code before the disk is marked
> live.  Moving the cgroup initialization earlier will help to have a
> fully initialized struct device in the gendisk for the cgroup code to
> use in the future.  Similarly tear the cgroup information down in
> del_gendisk to be symmetric and because none of the cgroup tracking is
> needed once non-passthrough I/O stops.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  block/genhd.c | 17 +++++++++--------
>  1 file changed, 9 insertions(+), 8 deletions(-)

Looks good to me. Feel free to add
Reviewed-by: Andreas Herrmann <aherrmann@suse.de>

> diff --git a/block/genhd.c b/block/genhd.c
> index 23cf83b3331cde..705dec0800d62e 100644
> --- a/block/genhd.c
> +++ b/block/genhd.c
> @@ -466,10 +466,14 @@ int __must_check device_add_disk(struct device *parent, struct gendisk *disk,
>  	 */
>  	pm_runtime_set_memalloc_noio(ddev, true);
>  
> -	ret = blk_integrity_add(disk);
> +	ret = blkcg_init_disk(disk);
>  	if (ret)
>  		goto out_del_block_link;
>  
> +	ret = blk_integrity_add(disk);
> +	if (ret)
> +		goto out_blkcg_exit;
> +
>  	disk->part0->bd_holder_dir =
>  		kobject_create_and_add("holders", &ddev->kobj);
>  	if (!disk->part0->bd_holder_dir) {
> @@ -534,6 +538,8 @@ int __must_check device_add_disk(struct device *parent, struct gendisk *disk,
>  	kobject_put(disk->part0->bd_holder_dir);
>  out_del_integrity:
>  	blk_integrity_del(disk);
> +out_blkcg_exit:
> +	blkcg_exit_disk(disk);
>  out_del_block_link:
>  	if (!sysfs_deprecated)
>  		sysfs_remove_link(block_depr, dev_name(ddev));
> @@ -662,6 +668,8 @@ void del_gendisk(struct gendisk *disk)
>  	rq_qos_exit(q);
>  	blk_mq_unquiesce_queue(q);
>  
> +	blkcg_exit_disk(disk);
> +
>  	/*
>  	 * If the disk does not own the queue, allow using passthrough requests
>  	 * again.  Else leave the queue frozen to fail all I/O.
> @@ -1171,8 +1179,6 @@ static void disk_release(struct device *dev)
>  	    !test_bit(GD_ADDED, &disk->state))
>  		blk_mq_exit_queue(disk->queue);
>  
> -	blkcg_exit_disk(disk);
> -
>  	bioset_exit(&disk->bio_split);
>  
>  	disk_release_events(disk);
> @@ -1385,9 +1391,6 @@ struct gendisk *__alloc_disk_node(struct request_queue *q, int node_id,
>  	if (xa_insert(&disk->part_tbl, 0, disk->part0, GFP_KERNEL))
>  		goto out_destroy_part_tbl;
>  
> -	if (blkcg_init_disk(disk))
> -		goto out_erase_part0;
> -
>  	rand_initialize_disk(disk);
>  	disk_to_dev(disk)->class = &block_class;
>  	disk_to_dev(disk)->type = &disk_type;
> @@ -1400,8 +1403,6 @@ struct gendisk *__alloc_disk_node(struct request_queue *q, int node_id,
>  #endif
>  	return disk;
>  
> -out_erase_part0:
> -	xa_erase(&disk->part_tbl, 0);
>  out_destroy_part_tbl:
>  	xa_destroy(&disk->part_tbl);
>  	disk->part0->bd_disk = NULL;
> -- 
> 2.39.0
> 

-- 
Regards,
Andreas

SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nürnberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Martje Boudien Moerman
(HRB 36809, AG Nürnberg)

Re: [PATCH 03/15] blk-cgroup: delay blk-cgroup initialization until add_disk

[Hannes Reinecke]

On 1/17/23 09:12, Christoph Hellwig wrote:
> There is no need to initialize the group code before the disk is marked
> live.  Moving the cgroup initialization earlier will help to have a
> fully initialized struct device in the gendisk for the cgroup code to
> use in the future.  Similarly tear the cgroup information down in
> del_gendisk to be symmetric and because none of the cgroup tracking is
> needed once non-passthrough I/O stops.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>   block/genhd.c | 17 +++++++++--------
>   1 file changed, 9 insertions(+), 8 deletions(-)
> 
Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare@suse.de                              +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew
Myers, Andrew McDonald, Martje Boudien Moerman

[PATCH 04/15] blk-cgroup: pin the gendisk in struct blkcg_gq

[Christoph Hellwig]

Currently each blkcg_gq holds a request_queue reference, which is what
is used in the policies.  But a lot of these interface will move over to
use a gendisk, so store a disk in strut blkcg_gq and hold a reference to
it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/bfq-cgroup.c        |  6 +++---
 block/blk-cgroup-rwstat.c |  2 +-
 block/blk-cgroup.c        | 29 +++++++++++++----------------
 block/blk-cgroup.h        | 11 +++++------
 block/blk-iocost.c        |  2 +-
 block/blk-iolatency.c     |  4 ++--
 block/blk-throttle.c      |  4 ++--
 7 files changed, 27 insertions(+), 31 deletions(-)

diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c
index a6e8da5f5cfdc1..72a033776722c9 100644
--- a/block/bfq-cgroup.c
+++ b/block/bfq-cgroup.c
@@ -407,7 +407,7 @@ static void bfqg_stats_xfer_dead(struct bfq_group *bfqg)
 
 	parent = bfqg_parent(bfqg);
 
-	lockdep_assert_held(&bfqg_to_blkg(bfqg)->q->queue_lock);
+	lockdep_assert_held(&bfqg_to_blkg(bfqg)->disk->queue->queue_lock);
 
 	if (unlikely(!parent))
 		return;
@@ -538,7 +538,7 @@ static void bfq_pd_init(struct blkg_policy_data *pd)
 {
 	struct blkcg_gq *blkg = pd_to_blkg(pd);
 	struct bfq_group *bfqg = blkg_to_bfqg(blkg);
-	struct bfq_data *bfqd = blkg->q->elevator->elevator_data;
+	struct bfq_data *bfqd = blkg->disk->queue->elevator->elevator_data;
 	struct bfq_entity *entity = &bfqg->entity;
 	struct bfq_group_data *d = blkcg_to_bfqgd(blkg->blkcg);
 
@@ -1203,7 +1203,7 @@ static u64 bfqg_prfill_stat_recursive(struct seq_file *sf,
 	struct cgroup_subsys_state *pos_css;
 	u64 sum = 0;
 
-	lockdep_assert_held(&blkg->q->queue_lock);
+	lockdep_assert_held(&blkg->disk->queue->queue_lock);
 
 	rcu_read_lock();
 	blkg_for_each_descendant_pre(pos_blkg, pos_css, blkg) {
diff --git a/block/blk-cgroup-rwstat.c b/block/blk-cgroup-rwstat.c
index 3304e841df7ce9..b8b8c82e667a3b 100644
--- a/block/blk-cgroup-rwstat.c
+++ b/block/blk-cgroup-rwstat.c
@@ -107,7 +107,7 @@ void blkg_rwstat_recursive_sum(struct blkcg_gq *blkg, struct blkcg_policy *pol,
 	struct cgroup_subsys_state *pos_css;
 	unsigned int i;
 
-	lockdep_assert_held(&blkg->q->queue_lock);
+	lockdep_assert_held(&blkg->disk->queue->queue_lock);
 
 	memset(sum, 0, sizeof(*sum));
 	rcu_read_lock();
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 30d493b43f9272..f5a634ed098db0 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -131,8 +131,8 @@ static void blkg_free(struct blkcg_gq *blkg)
 		if (blkg->pd[i])
 			blkcg_policy[i]->pd_free_fn(blkg->pd[i]);
 
-	if (blkg->q)
-		blk_put_queue(blkg->q);
+	if (blkg->disk)
+		put_disk(blkg->disk);
 	free_percpu(blkg->iostat_cpu);
 	percpu_ref_exit(&blkg->refcnt);
 	kfree(blkg);
@@ -245,10 +245,9 @@ static struct blkcg_gq *blkg_alloc(struct blkcg *blkcg, struct gendisk *disk,
 	if (!blkg->iostat_cpu)
 		goto err_free;
 
-	if (!blk_get_queue(disk->queue))
-		goto err_free;
+	get_device(disk_to_dev(disk));
 
-	blkg->q = disk->queue;
+	blkg->disk = disk;
 	INIT_LIST_HEAD(&blkg->q_node);
 	spin_lock_init(&blkg->async_bio_lock);
 	bio_list_init(&blkg->async_bios);
@@ -443,7 +442,7 @@ static void blkg_destroy(struct blkcg_gq *blkg)
 	struct blkcg *blkcg = blkg->blkcg;
 	int i;
 
-	lockdep_assert_held(&blkg->q->queue_lock);
+	lockdep_assert_held(&blkg->disk->queue->queue_lock);
 	lockdep_assert_held(&blkcg->lock);
 
 	/* Something wrong if we are trying to remove same group twice */
@@ -459,7 +458,7 @@ static void blkg_destroy(struct blkcg_gq *blkg)
 
 	blkg->online = false;
 
-	radix_tree_delete(&blkcg->blkg_tree, blkg->q->id);
+	radix_tree_delete(&blkcg->blkg_tree, blkg->disk->queue->id);
 	list_del_init(&blkg->q_node);
 	hlist_del_init_rcu(&blkg->blkcg_node);
 
@@ -547,9 +546,7 @@ static int blkcg_reset_stats(struct cgroup_subsys_state *css,
 
 const char *blkg_dev_name(struct blkcg_gq *blkg)
 {
-	if (!blkg->q->disk || !blkg->q->disk->bdi->dev)
-		return NULL;
-	return bdi_dev_name(blkg->q->disk->bdi);
+	return bdi_dev_name(blkg->disk->bdi);
 }
 
 /**
@@ -581,10 +578,10 @@ void blkcg_print_blkgs(struct seq_file *sf, struct blkcg *blkcg,
 
 	rcu_read_lock();
 	hlist_for_each_entry_rcu(blkg, &blkcg->blkg_list, blkcg_node) {
-		spin_lock_irq(&blkg->q->queue_lock);
-		if (blkcg_policy_enabled(blkg->q, pol))
+		spin_lock_irq(&blkg->disk->queue->queue_lock);
+		if (blkcg_policy_enabled(blkg->disk->queue, pol))
 			total += prfill(sf, blkg->pd[pol->plid], data);
-		spin_unlock_irq(&blkg->q->queue_lock);
+		spin_unlock_irq(&blkg->disk->queue->queue_lock);
 	}
 	rcu_read_unlock();
 
@@ -1008,9 +1005,9 @@ static int blkcg_print_stat(struct seq_file *sf, void *v)
 
 	rcu_read_lock();
 	hlist_for_each_entry_rcu(blkg, &blkcg->blkg_list, blkcg_node) {
-		spin_lock_irq(&blkg->q->queue_lock);
+		spin_lock_irq(&blkg->disk->queue->queue_lock);
 		blkcg_print_one_stat(blkg, sf);
-		spin_unlock_irq(&blkg->q->queue_lock);
+		spin_unlock_irq(&blkg->disk->queue->queue_lock);
 	}
 	rcu_read_unlock();
 	return 0;
@@ -1080,7 +1077,7 @@ static void blkcg_destroy_blkgs(struct blkcg *blkcg)
 	while (!hlist_empty(&blkcg->blkg_list)) {
 		struct blkcg_gq *blkg = hlist_entry(blkcg->blkg_list.first,
 						struct blkcg_gq, blkcg_node);
-		struct request_queue *q = blkg->q;
+		struct request_queue *q = blkg->disk->queue;
 
 		if (need_resched() || !spin_trylock(&q->queue_lock)) {
 			/*
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index f126fe36001eb3..85b267234823ab 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -53,8 +53,7 @@ struct blkg_iostat_set {
 
 /* association between a blk cgroup and a request queue */
 struct blkcg_gq {
-	/* Pointer to the associated request_queue */
-	struct request_queue		*q;
+	struct gendisk			*disk;
 	struct list_head		q_node;
 	struct hlist_node		blkcg_node;
 	struct blkcg			*blkcg;
@@ -251,11 +250,11 @@ static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg,
 		return q->root_blkg;
 
 	blkg = rcu_dereference(blkcg->blkg_hint);
-	if (blkg && blkg->q == q)
+	if (blkg && blkg->disk->queue == q)
 		return blkg;
 
 	blkg = radix_tree_lookup(&blkcg->blkg_tree, q->id);
-	if (blkg && blkg->q != q)
+	if (blkg && blkg->disk->queue != q)
 		blkg = NULL;
 	return blkg;
 }
@@ -355,7 +354,7 @@ static inline void blkg_put(struct blkcg_gq *blkg)
 #define blkg_for_each_descendant_pre(d_blkg, pos_css, p_blkg)		\
 	css_for_each_descendant_pre((pos_css), &(p_blkg)->blkcg->css)	\
 		if (((d_blkg) = blkg_lookup(css_to_blkcg(pos_css),	\
-					    (p_blkg)->q)))
+					    (p_blkg)->disk->queue)))
 
 /**
  * blkg_for_each_descendant_post - post-order walk of a blkg's descendants
@@ -370,7 +369,7 @@ static inline void blkg_put(struct blkcg_gq *blkg)
 #define blkg_for_each_descendant_post(d_blkg, pos_css, p_blkg)		\
 	css_for_each_descendant_post((pos_css), &(p_blkg)->blkcg->css)	\
 		if (((d_blkg) = blkg_lookup(css_to_blkcg(pos_css),	\
-					    (p_blkg)->q)))
+					    (p_blkg)->disk->queue)))
 
 bool __blkcg_punt_bio_submit(struct bio *bio);
 
diff --git a/block/blk-iocost.c b/block/blk-iocost.c
index 6955605629e4f8..3b965d6b037970 100644
--- a/block/blk-iocost.c
+++ b/block/blk-iocost.c
@@ -2946,7 +2946,7 @@ static void ioc_pd_init(struct blkg_policy_data *pd)
 {
 	struct ioc_gq *iocg = pd_to_iocg(pd);
 	struct blkcg_gq *blkg = pd_to_blkg(&iocg->pd);
-	struct ioc *ioc = q_to_ioc(blkg->q);
+	struct ioc *ioc = q_to_ioc(blkg->disk->queue);
 	struct ioc_now now;
 	struct blkcg_gq *tblkg;
 	unsigned long flags;
diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c
index ecdc1074183625..b55eac2cf91944 100644
--- a/block/blk-iolatency.c
+++ b/block/blk-iolatency.c
@@ -974,12 +974,12 @@ static void iolatency_pd_init(struct blkg_policy_data *pd)
 {
 	struct iolatency_grp *iolat = pd_to_lat(pd);
 	struct blkcg_gq *blkg = lat_to_blkg(iolat);
-	struct rq_qos *rqos = blkcg_rq_qos(blkg->q);
+	struct rq_qos *rqos = blkcg_rq_qos(blkg->disk->queue);
 	struct blk_iolatency *blkiolat = BLKIOLATENCY(rqos);
 	u64 now = ktime_to_ns(ktime_get());
 	int cpu;
 
-	if (blk_queue_nonrot(blkg->q))
+	if (blk_queue_nonrot(blkg->disk->queue))
 		iolat->ssd = true;
 	else
 		iolat->ssd = false;
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 6fb5a2f9e1eed5..f802d8f9099430 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -388,7 +388,7 @@ static void throtl_pd_init(struct blkg_policy_data *pd)
 {
 	struct throtl_grp *tg = pd_to_tg(pd);
 	struct blkcg_gq *blkg = tg_to_blkg(tg);
-	struct throtl_data *td = blkg->q->td;
+	struct throtl_data *td = blkg->disk->queue->td;
 	struct throtl_service_queue *sq = &tg->service_queue;
 
 	/*
@@ -1175,7 +1175,7 @@ static void throtl_pending_timer_fn(struct timer_list *t)
 
 	/* throtl_data may be gone, so figure out request queue by blkg */
 	if (tg)
-		q = tg->pd.blkg->q;
+		q = tg->pd.blkg->disk->queue;
 	else
 		q = td->queue;
 
-- 
2.39.0

Re: [PATCH 04/15] blk-cgroup: pin the gendisk in struct blkcg_gq

[Andreas Herrmann]

On Tue, Jan 17, 2023 at 09:12:46AM +0100, Christoph Hellwig wrote:
> Currently each blkcg_gq holds a request_queue reference, which is what
> is used in the policies.  But a lot of these interface will move over to
                                               ^^^^^^^^^
					       interfaces
> use a gendisk, so store a disk in strut blkcg_gq and hold a reference to
                                    ^^^^^
				    struct
> it.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  block/bfq-cgroup.c        |  6 +++---
>  block/blk-cgroup-rwstat.c |  2 +-
>  block/blk-cgroup.c        | 29 +++++++++++++----------------
>  block/blk-cgroup.h        | 11 +++++------
>  block/blk-iocost.c        |  2 +-
>  block/blk-iolatency.c     |  4 ++--
>  block/blk-throttle.c      |  4 ++--
>  7 files changed, 27 insertions(+), 31 deletions(-)

Looks good to me. Feel free to add
Reviewed-by: Andreas Herrmann <aherrmann@suse.de>

> diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c
> index a6e8da5f5cfdc1..72a033776722c9 100644
> --- a/block/bfq-cgroup.c
> +++ b/block/bfq-cgroup.c
> @@ -407,7 +407,7 @@ static void bfqg_stats_xfer_dead(struct bfq_group *bfqg)
>  
>  	parent = bfqg_parent(bfqg);
>  
> -	lockdep_assert_held(&bfqg_to_blkg(bfqg)->q->queue_lock);
> +	lockdep_assert_held(&bfqg_to_blkg(bfqg)->disk->queue->queue_lock);
>  
>  	if (unlikely(!parent))
>  		return;
> @@ -538,7 +538,7 @@ static void bfq_pd_init(struct blkg_policy_data *pd)
>  {
>  	struct blkcg_gq *blkg = pd_to_blkg(pd);
>  	struct bfq_group *bfqg = blkg_to_bfqg(blkg);
> -	struct bfq_data *bfqd = blkg->q->elevator->elevator_data;
> +	struct bfq_data *bfqd = blkg->disk->queue->elevator->elevator_data;
>  	struct bfq_entity *entity = &bfqg->entity;
>  	struct bfq_group_data *d = blkcg_to_bfqgd(blkg->blkcg);
>  
> @@ -1203,7 +1203,7 @@ static u64 bfqg_prfill_stat_recursive(struct seq_file *sf,
>  	struct cgroup_subsys_state *pos_css;
>  	u64 sum = 0;
>  
> -	lockdep_assert_held(&blkg->q->queue_lock);
> +	lockdep_assert_held(&blkg->disk->queue->queue_lock);
>  
>  	rcu_read_lock();
>  	blkg_for_each_descendant_pre(pos_blkg, pos_css, blkg) {
> diff --git a/block/blk-cgroup-rwstat.c b/block/blk-cgroup-rwstat.c
> index 3304e841df7ce9..b8b8c82e667a3b 100644
> --- a/block/blk-cgroup-rwstat.c
> +++ b/block/blk-cgroup-rwstat.c
> @@ -107,7 +107,7 @@ void blkg_rwstat_recursive_sum(struct blkcg_gq *blkg, struct blkcg_policy *pol,
>  	struct cgroup_subsys_state *pos_css;
>  	unsigned int i;
>  
> -	lockdep_assert_held(&blkg->q->queue_lock);
> +	lockdep_assert_held(&blkg->disk->queue->queue_lock);
>  
>  	memset(sum, 0, sizeof(*sum));
>  	rcu_read_lock();
> diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
> index 30d493b43f9272..f5a634ed098db0 100644
> --- a/block/blk-cgroup.c
> +++ b/block/blk-cgroup.c
> @@ -131,8 +131,8 @@ static void blkg_free(struct blkcg_gq *blkg)
>  		if (blkg->pd[i])
>  			blkcg_policy[i]->pd_free_fn(blkg->pd[i]);
>  
> -	if (blkg->q)
> -		blk_put_queue(blkg->q);
> +	if (blkg->disk)
> +		put_disk(blkg->disk);
>  	free_percpu(blkg->iostat_cpu);
>  	percpu_ref_exit(&blkg->refcnt);
>  	kfree(blkg);
> @@ -245,10 +245,9 @@ static struct blkcg_gq *blkg_alloc(struct blkcg *blkcg, struct gendisk *disk,
>  	if (!blkg->iostat_cpu)
>  		goto err_free;
>  
> -	if (!blk_get_queue(disk->queue))
> -		goto err_free;
> +	get_device(disk_to_dev(disk));
>  
> -	blkg->q = disk->queue;
> +	blkg->disk = disk;
>  	INIT_LIST_HEAD(&blkg->q_node);
>  	spin_lock_init(&blkg->async_bio_lock);
>  	bio_list_init(&blkg->async_bios);
> @@ -443,7 +442,7 @@ static void blkg_destroy(struct blkcg_gq *blkg)
>  	struct blkcg *blkcg = blkg->blkcg;
>  	int i;
>  
> -	lockdep_assert_held(&blkg->q->queue_lock);
> +	lockdep_assert_held(&blkg->disk->queue->queue_lock);
>  	lockdep_assert_held(&blkcg->lock);
>  
>  	/* Something wrong if we are trying to remove same group twice */
> @@ -459,7 +458,7 @@ static void blkg_destroy(struct blkcg_gq *blkg)
>  
>  	blkg->online = false;
>  
> -	radix_tree_delete(&blkcg->blkg_tree, blkg->q->id);
> +	radix_tree_delete(&blkcg->blkg_tree, blkg->disk->queue->id);
>  	list_del_init(&blkg->q_node);
>  	hlist_del_init_rcu(&blkg->blkcg_node);
>  
> @@ -547,9 +546,7 @@ static int blkcg_reset_stats(struct cgroup_subsys_state *css,
>  
>  const char *blkg_dev_name(struct blkcg_gq *blkg)
>  {
> -	if (!blkg->q->disk || !blkg->q->disk->bdi->dev)
> -		return NULL;
> -	return bdi_dev_name(blkg->q->disk->bdi);
> +	return bdi_dev_name(blkg->disk->bdi);
>  }
>  
>  /**
> @@ -581,10 +578,10 @@ void blkcg_print_blkgs(struct seq_file *sf, struct blkcg *blkcg,
>  
>  	rcu_read_lock();
>  	hlist_for_each_entry_rcu(blkg, &blkcg->blkg_list, blkcg_node) {
> -		spin_lock_irq(&blkg->q->queue_lock);
> -		if (blkcg_policy_enabled(blkg->q, pol))
> +		spin_lock_irq(&blkg->disk->queue->queue_lock);
> +		if (blkcg_policy_enabled(blkg->disk->queue, pol))
>  			total += prfill(sf, blkg->pd[pol->plid], data);
> -		spin_unlock_irq(&blkg->q->queue_lock);
> +		spin_unlock_irq(&blkg->disk->queue->queue_lock);
>  	}
>  	rcu_read_unlock();
>  
> @@ -1008,9 +1005,9 @@ static int blkcg_print_stat(struct seq_file *sf, void *v)
>  
>  	rcu_read_lock();
>  	hlist_for_each_entry_rcu(blkg, &blkcg->blkg_list, blkcg_node) {
> -		spin_lock_irq(&blkg->q->queue_lock);
> +		spin_lock_irq(&blkg->disk->queue->queue_lock);
>  		blkcg_print_one_stat(blkg, sf);
> -		spin_unlock_irq(&blkg->q->queue_lock);
> +		spin_unlock_irq(&blkg->disk->queue->queue_lock);
>  	}
>  	rcu_read_unlock();
>  	return 0;
> @@ -1080,7 +1077,7 @@ static void blkcg_destroy_blkgs(struct blkcg *blkcg)
>  	while (!hlist_empty(&blkcg->blkg_list)) {
>  		struct blkcg_gq *blkg = hlist_entry(blkcg->blkg_list.first,
>  						struct blkcg_gq, blkcg_node);
> -		struct request_queue *q = blkg->q;
> +		struct request_queue *q = blkg->disk->queue;
>  
>  		if (need_resched() || !spin_trylock(&q->queue_lock)) {
>  			/*
> diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
> index f126fe36001eb3..85b267234823ab 100644
> --- a/block/blk-cgroup.h
> +++ b/block/blk-cgroup.h
> @@ -53,8 +53,7 @@ struct blkg_iostat_set {
>  
>  /* association between a blk cgroup and a request queue */
>  struct blkcg_gq {
> -	/* Pointer to the associated request_queue */
> -	struct request_queue		*q;
> +	struct gendisk			*disk;
>  	struct list_head		q_node;
>  	struct hlist_node		blkcg_node;
>  	struct blkcg			*blkcg;
> @@ -251,11 +250,11 @@ static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg,
>  		return q->root_blkg;
>  
>  	blkg = rcu_dereference(blkcg->blkg_hint);
> -	if (blkg && blkg->q == q)
> +	if (blkg && blkg->disk->queue == q)
>  		return blkg;
>  
>  	blkg = radix_tree_lookup(&blkcg->blkg_tree, q->id);
> -	if (blkg && blkg->q != q)
> +	if (blkg && blkg->disk->queue != q)
>  		blkg = NULL;
>  	return blkg;
>  }
> @@ -355,7 +354,7 @@ static inline void blkg_put(struct blkcg_gq *blkg)
>  #define blkg_for_each_descendant_pre(d_blkg, pos_css, p_blkg)		\
>  	css_for_each_descendant_pre((pos_css), &(p_blkg)->blkcg->css)	\
>  		if (((d_blkg) = blkg_lookup(css_to_blkcg(pos_css),	\
> -					    (p_blkg)->q)))
> +					    (p_blkg)->disk->queue)))
>  
>  /**
>   * blkg_for_each_descendant_post - post-order walk of a blkg's descendants
> @@ -370,7 +369,7 @@ static inline void blkg_put(struct blkcg_gq *blkg)
>  #define blkg_for_each_descendant_post(d_blkg, pos_css, p_blkg)		\
>  	css_for_each_descendant_post((pos_css), &(p_blkg)->blkcg->css)	\
>  		if (((d_blkg) = blkg_lookup(css_to_blkcg(pos_css),	\
> -					    (p_blkg)->q)))
> +					    (p_blkg)->disk->queue)))
>  
>  bool __blkcg_punt_bio_submit(struct bio *bio);
>  
> diff --git a/block/blk-iocost.c b/block/blk-iocost.c
> index 6955605629e4f8..3b965d6b037970 100644
> --- a/block/blk-iocost.c
> +++ b/block/blk-iocost.c
> @@ -2946,7 +2946,7 @@ static void ioc_pd_init(struct blkg_policy_data *pd)
>  {
>  	struct ioc_gq *iocg = pd_to_iocg(pd);
>  	struct blkcg_gq *blkg = pd_to_blkg(&iocg->pd);
> -	struct ioc *ioc = q_to_ioc(blkg->q);
> +	struct ioc *ioc = q_to_ioc(blkg->disk->queue);
>  	struct ioc_now now;
>  	struct blkcg_gq *tblkg;
>  	unsigned long flags;
> diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c
> index ecdc1074183625..b55eac2cf91944 100644
> --- a/block/blk-iolatency.c
> +++ b/block/blk-iolatency.c
> @@ -974,12 +974,12 @@ static void iolatency_pd_init(struct blkg_policy_data *pd)
>  {
>  	struct iolatency_grp *iolat = pd_to_lat(pd);
>  	struct blkcg_gq *blkg = lat_to_blkg(iolat);
> -	struct rq_qos *rqos = blkcg_rq_qos(blkg->q);
> +	struct rq_qos *rqos = blkcg_rq_qos(blkg->disk->queue);
>  	struct blk_iolatency *blkiolat = BLKIOLATENCY(rqos);
>  	u64 now = ktime_to_ns(ktime_get());
>  	int cpu;
>  
> -	if (blk_queue_nonrot(blkg->q))
> +	if (blk_queue_nonrot(blkg->disk->queue))
>  		iolat->ssd = true;
>  	else
>  		iolat->ssd = false;
> diff --git a/block/blk-throttle.c b/block/blk-throttle.c
> index 6fb5a2f9e1eed5..f802d8f9099430 100644
> --- a/block/blk-throttle.c
> +++ b/block/blk-throttle.c
> @@ -388,7 +388,7 @@ static void throtl_pd_init(struct blkg_policy_data *pd)
>  {
>  	struct throtl_grp *tg = pd_to_tg(pd);
>  	struct blkcg_gq *blkg = tg_to_blkg(tg);
> -	struct throtl_data *td = blkg->q->td;
> +	struct throtl_data *td = blkg->disk->queue->td;
>  	struct throtl_service_queue *sq = &tg->service_queue;
>  
>  	/*
> @@ -1175,7 +1175,7 @@ static void throtl_pending_timer_fn(struct timer_list *t)
>  
>  	/* throtl_data may be gone, so figure out request queue by blkg */
>  	if (tg)
> -		q = tg->pd.blkg->q;
> +		q = tg->pd.blkg->disk->queue;
>  	else
>  		q = td->queue;
>  
> -- 
> 2.39.0
> 

-- 
Regards,
Andreas

SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nürnberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Martje Boudien Moerman
(HRB 36809, AG Nürnberg)

Re: [PATCH 04/15] blk-cgroup: pin the gendisk in struct blkcg_gq

[Hannes Reinecke]

On 1/17/23 09:12, Christoph Hellwig wrote:
> Currently each blkcg_gq holds a request_queue reference, which is what
> is used in the policies.  But a lot of these interface will move over to
> use a gendisk, so store a disk in strut blkcg_gq and hold a reference to
> it.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>   block/bfq-cgroup.c        |  6 +++---
>   block/blk-cgroup-rwstat.c |  2 +-
>   block/blk-cgroup.c        | 29 +++++++++++++----------------
>   block/blk-cgroup.h        | 11 +++++------
>   block/blk-iocost.c        |  2 +-
>   block/blk-iolatency.c     |  4 ++--
>   block/blk-throttle.c      |  4 ++--
>   7 files changed, 27 insertions(+), 31 deletions(-)
> 
Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare@suse.de                              +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew
Myers, Andrew McDonald, Martje Boudien Moerman

[PATCH 05/15] blk-cgroup: store a gendisk to throttle in struct task_struct

[Christoph Hellwig]

Switch from a request_queue pointer and reference to a gendisk once
for the throttle information in struct task_struct.

Move the check for the dead disk to the latest place now that is is
unboundled from the reference grab.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-cgroup.c    | 37 +++++++++++++++++++------------------
 include/linux/sched.h |  2 +-
 kernel/fork.c         |  2 +-
 mm/swapfile.c         |  2 +-
 4 files changed, 22 insertions(+), 21 deletions(-)

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index f5a634ed098db0..603e911d1350db 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -1334,9 +1334,9 @@ static void blkcg_bind(struct cgroup_subsys_state *root_css)
 
 static void blkcg_exit(struct task_struct *tsk)
 {
-	if (tsk->throttle_queue)
-		blk_put_queue(tsk->throttle_queue);
-	tsk->throttle_queue = NULL;
+	if (tsk->throttle_disk)
+		put_disk(tsk->throttle_disk);
+	tsk->throttle_disk = NULL;
 }
 
 struct cgroup_subsys io_cgrp_subsys = {
@@ -1778,29 +1778,32 @@ static void blkcg_maybe_throttle_blkg(struct blkcg_gq *blkg, bool use_memdelay)
  *
  * This is only called if we've been marked with set_notify_resume().  Obviously
  * we can be set_notify_resume() for reasons other than blkcg throttling, so we
- * check to see if current->throttle_queue is set and if not this doesn't do
+ * check to see if current->throttle_disk is set and if not this doesn't do
  * anything.  This should only ever be called by the resume code, it's not meant
  * to be called by people willy-nilly as it will actually do the work to
  * throttle the task if it is setup for throttling.
  */
 void blkcg_maybe_throttle_current(void)
 {
-	struct request_queue *q = current->throttle_queue;
+	struct gendisk *disk = current->throttle_disk;
 	struct blkcg *blkcg;
 	struct blkcg_gq *blkg;
 	bool use_memdelay = current->use_memdelay;
 
-	if (!q)
+	if (!disk)
 		return;
 
-	current->throttle_queue = NULL;
+	current->throttle_disk = NULL;
 	current->use_memdelay = false;
 
+	if (test_bit(GD_DEAD, &disk->state))
+		goto out_put_disk;
+
 	rcu_read_lock();
 	blkcg = css_to_blkcg(blkcg_css());
 	if (!blkcg)
 		goto out;
-	blkg = blkg_lookup(blkcg, q);
+	blkg = blkg_lookup(blkcg, disk->queue);
 	if (!blkg)
 		goto out;
 	if (!blkg_tryget(blkg))
@@ -1809,11 +1812,12 @@ void blkcg_maybe_throttle_current(void)
 
 	blkcg_maybe_throttle_blkg(blkg, use_memdelay);
 	blkg_put(blkg);
-	blk_put_queue(q);
+	put_disk(disk);
 	return;
 out:
 	rcu_read_unlock();
-	blk_put_queue(q);
+out_put_disk:
+	put_disk(disk);
 }
 
 /**
@@ -1835,18 +1839,15 @@ void blkcg_maybe_throttle_current(void)
  */
 void blkcg_schedule_throttle(struct gendisk *disk, bool use_memdelay)
 {
-	struct request_queue *q = disk->queue;
-
 	if (unlikely(current->flags & PF_KTHREAD))
 		return;
 
-	if (current->throttle_queue != q) {
-		if (!blk_get_queue(q))
-			return;
+	if (current->throttle_disk != disk) {
+		get_device(disk_to_dev(disk));
 
-		if (current->throttle_queue)
-			blk_put_queue(current->throttle_queue);
-		current->throttle_queue = q;
+		if (current->throttle_disk)
+			put_disk(current->throttle_disk);
+		current->throttle_disk = disk;
 	}
 
 	if (use_memdelay)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 853d08f7562bda..6f6ce9ca709798 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1436,7 +1436,7 @@ struct task_struct {
 #endif
 
 #ifdef CONFIG_BLK_CGROUP
-	struct request_queue		*throttle_queue;
+	struct gendisk			*throttle_disk;
 #endif
 
 #ifdef CONFIG_UPROBES
diff --git a/kernel/fork.c b/kernel/fork.c
index 9f7fe354189785..d9c97704b7c9a4 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1044,7 +1044,7 @@ static struct task_struct *dup_task_struct(struct task_struct *orig, int node)
 #endif
 
 #ifdef CONFIG_BLK_CGROUP
-	tsk->throttle_queue = NULL;
+	tsk->throttle_disk = NULL;
 	tsk->use_memdelay = 0;
 #endif
 
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 908a529bca12c9..3e0a742fb7bbff 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -3642,7 +3642,7 @@ void __cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask)
 	 * We've already scheduled a throttle, avoid taking the global swap
 	 * lock.
 	 */
-	if (current->throttle_queue)
+	if (current->throttle_disk)
 		return;
 
 	spin_lock(&swap_avail_lock);
-- 
2.39.0

Re: [PATCH 05/15] blk-cgroup: store a gendisk to throttle in struct task_struct

[Andreas Herrmann]

On Tue, Jan 17, 2023 at 09:12:47AM +0100, Christoph Hellwig wrote:
> Switch from a request_queue pointer and reference to a gendisk once
> for the throttle information in struct task_struct.
> 
> Move the check for the dead disk to the latest place now that is is
                                                                ^^
								it
> unboundled from the reference grab.
  ^^^^^^^^^^
  unbundled
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  block/blk-cgroup.c    | 37 +++++++++++++++++++------------------
>  include/linux/sched.h |  2 +-
>  kernel/fork.c         |  2 +-
>  mm/swapfile.c         |  2 +-
>  4 files changed, 22 insertions(+), 21 deletions(-)

Looks good to me. Feel free to add
Reviewed-by: Andreas Herrmann <aherrmann@suse.de>

> diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
> index f5a634ed098db0..603e911d1350db 100644
> --- a/block/blk-cgroup.c
> +++ b/block/blk-cgroup.c
> @@ -1334,9 +1334,9 @@ static void blkcg_bind(struct cgroup_subsys_state *root_css)
>  
>  static void blkcg_exit(struct task_struct *tsk)
>  {
> -	if (tsk->throttle_queue)
> -		blk_put_queue(tsk->throttle_queue);
> -	tsk->throttle_queue = NULL;
> +	if (tsk->throttle_disk)
> +		put_disk(tsk->throttle_disk);
> +	tsk->throttle_disk = NULL;
>  }
>  
>  struct cgroup_subsys io_cgrp_subsys = {
> @@ -1778,29 +1778,32 @@ static void blkcg_maybe_throttle_blkg(struct blkcg_gq *blkg, bool use_memdelay)
>   *
>   * This is only called if we've been marked with set_notify_resume().  Obviously
>   * we can be set_notify_resume() for reasons other than blkcg throttling, so we
> - * check to see if current->throttle_queue is set and if not this doesn't do
> + * check to see if current->throttle_disk is set and if not this doesn't do
>   * anything.  This should only ever be called by the resume code, it's not meant
>   * to be called by people willy-nilly as it will actually do the work to
>   * throttle the task if it is setup for throttling.
>   */
>  void blkcg_maybe_throttle_current(void)
>  {
> -	struct request_queue *q = current->throttle_queue;
> +	struct gendisk *disk = current->throttle_disk;
>  	struct blkcg *blkcg;
>  	struct blkcg_gq *blkg;
>  	bool use_memdelay = current->use_memdelay;
>  
> -	if (!q)
> +	if (!disk)
>  		return;
>  
> -	current->throttle_queue = NULL;
> +	current->throttle_disk = NULL;
>  	current->use_memdelay = false;
>  
> +	if (test_bit(GD_DEAD, &disk->state))
> +		goto out_put_disk;
> +
>  	rcu_read_lock();
>  	blkcg = css_to_blkcg(blkcg_css());
>  	if (!blkcg)
>  		goto out;
> -	blkg = blkg_lookup(blkcg, q);
> +	blkg = blkg_lookup(blkcg, disk->queue);
>  	if (!blkg)
>  		goto out;
>  	if (!blkg_tryget(blkg))
> @@ -1809,11 +1812,12 @@ void blkcg_maybe_throttle_current(void)
>  
>  	blkcg_maybe_throttle_blkg(blkg, use_memdelay);
>  	blkg_put(blkg);
> -	blk_put_queue(q);
> +	put_disk(disk);
>  	return;
>  out:
>  	rcu_read_unlock();
> -	blk_put_queue(q);
> +out_put_disk:
> +	put_disk(disk);
>  }
>  
>  /**
> @@ -1835,18 +1839,15 @@ void blkcg_maybe_throttle_current(void)
>   */
>  void blkcg_schedule_throttle(struct gendisk *disk, bool use_memdelay)
>  {
> -	struct request_queue *q = disk->queue;
> -
>  	if (unlikely(current->flags & PF_KTHREAD))
>  		return;
>  
> -	if (current->throttle_queue != q) {
> -		if (!blk_get_queue(q))
> -			return;
> +	if (current->throttle_disk != disk) {
> +		get_device(disk_to_dev(disk));
>  
> -		if (current->throttle_queue)
> -			blk_put_queue(current->throttle_queue);
> -		current->throttle_queue = q;
> +		if (current->throttle_disk)
> +			put_disk(current->throttle_disk);
> +		current->throttle_disk = disk;
>  	}
>  
>  	if (use_memdelay)
> diff --git a/include/linux/sched.h b/include/linux/sched.h
> index 853d08f7562bda..6f6ce9ca709798 100644
> --- a/include/linux/sched.h
> +++ b/include/linux/sched.h
> @@ -1436,7 +1436,7 @@ struct task_struct {
>  #endif
>  
>  #ifdef CONFIG_BLK_CGROUP
> -	struct request_queue		*throttle_queue;
> +	struct gendisk			*throttle_disk;
>  #endif
>  
>  #ifdef CONFIG_UPROBES
> diff --git a/kernel/fork.c b/kernel/fork.c
> index 9f7fe354189785..d9c97704b7c9a4 100644
> --- a/kernel/fork.c
> +++ b/kernel/fork.c
> @@ -1044,7 +1044,7 @@ static struct task_struct *dup_task_struct(struct task_struct *orig, int node)
>  #endif
>  
>  #ifdef CONFIG_BLK_CGROUP
> -	tsk->throttle_queue = NULL;
> +	tsk->throttle_disk = NULL;
>  	tsk->use_memdelay = 0;
>  #endif
>  
> diff --git a/mm/swapfile.c b/mm/swapfile.c
> index 908a529bca12c9..3e0a742fb7bbff 100644
> --- a/mm/swapfile.c
> +++ b/mm/swapfile.c
> @@ -3642,7 +3642,7 @@ void __cgroup_throttle_swaprate(struct page *page, gfp_t gfp_mask)
>  	 * We've already scheduled a throttle, avoid taking the global swap
>  	 * lock.
>  	 */
> -	if (current->throttle_queue)
> +	if (current->throttle_disk)
>  		return;
>  
>  	spin_lock(&swap_avail_lock);
> -- 
> 2.39.0
> 

-- 
Regards,
Andreas

SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nürnberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Martje Boudien Moerman
(HRB 36809, AG Nürnberg)

Re: [PATCH 05/15] blk-cgroup: store a gendisk to throttle in struct task_struct

[Hannes Reinecke]

On 1/17/23 09:12, Christoph Hellwig wrote:
> Switch from a request_queue pointer and reference to a gendisk once
> for the throttle information in struct task_struct.
> 
> Move the check for the dead disk to the latest place now that is is
> unboundled from the reference grab.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>   block/blk-cgroup.c    | 37 +++++++++++++++++++------------------
>   include/linux/sched.h |  2 +-
>   kernel/fork.c         |  2 +-
>   mm/swapfile.c         |  2 +-
>   4 files changed, 22 insertions(+), 21 deletions(-)
> 
Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare@suse.de                              +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew
Myers, Andrew McDonald, Martje Boudien Moerman

[PATCH 06/15] blk-wbt: pass a gendisk to wbt_{enable,disable}_default

[Christoph Hellwig]

Pass a gendisk to wbt_enable_default and wbt_disable_default to
prepare for phasing out usage of the request_queue in the blk-cgroup
code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/bfq-iosched.c | 4 ++--
 block/blk-iocost.c  | 4 ++--
 block/blk-sysfs.c   | 2 +-
 block/blk-wbt.c     | 7 ++++---
 block/blk-wbt.h     | 8 ++++----
 5 files changed, 13 insertions(+), 12 deletions(-)

diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index 815b884d6c5acf..68062243f2c142 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -7165,7 +7165,7 @@ static void bfq_exit_queue(struct elevator_queue *e)
 
 	blk_stat_disable_accounting(bfqd->queue);
 	clear_bit(ELEVATOR_FLAG_DISABLE_WBT, &e->flags);
-	wbt_enable_default(bfqd->queue);
+	wbt_enable_default(bfqd->queue->disk);
 
 	kfree(bfqd);
 }
@@ -7354,7 +7354,7 @@ static int bfq_init_queue(struct request_queue *q, struct elevator_type *e)
 	blk_queue_flag_set(QUEUE_FLAG_SQ_SCHED, q);
 
 	set_bit(ELEVATOR_FLAG_DISABLE_WBT, &eq->flags);
-	wbt_disable_default(q);
+	wbt_disable_default(q->disk);
 	blk_stat_enable_accounting(q);
 
 	return 0;
diff --git a/block/blk-iocost.c b/block/blk-iocost.c
index 3b965d6b037970..6f39ca99e9d76f 100644
--- a/block/blk-iocost.c
+++ b/block/blk-iocost.c
@@ -3270,11 +3270,11 @@ static ssize_t ioc_qos_write(struct kernfs_open_file *of, char *input,
 		blk_stat_enable_accounting(disk->queue);
 		blk_queue_flag_set(QUEUE_FLAG_RQ_ALLOC_TIME, disk->queue);
 		ioc->enabled = true;
-		wbt_disable_default(disk->queue);
+		wbt_disable_default(disk);
 	} else {
 		blk_queue_flag_clear(QUEUE_FLAG_RQ_ALLOC_TIME, disk->queue);
 		ioc->enabled = false;
-		wbt_enable_default(disk->queue);
+		wbt_enable_default(disk);
 	}
 
 	if (user) {
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 5486b6c57f6b8a..2074103865f45b 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -826,7 +826,7 @@ int blk_register_queue(struct gendisk *disk)
 		goto out_elv_unregister;
 
 	blk_queue_flag_set(QUEUE_FLAG_REGISTERED, q);
-	wbt_enable_default(q);
+	wbt_enable_default(disk);
 	blk_throtl_register(disk);
 
 	/* Now everything is ready and send out KOBJ_ADD uevent */
diff --git a/block/blk-wbt.c b/block/blk-wbt.c
index 68a774d7a7c9c0..8f9302134339c5 100644
--- a/block/blk-wbt.c
+++ b/block/blk-wbt.c
@@ -650,8 +650,9 @@ void wbt_set_write_cache(struct request_queue *q, bool write_cache_on)
 /*
  * Enable wbt if defaults are configured that way
  */
-void wbt_enable_default(struct request_queue *q)
+void wbt_enable_default(struct gendisk *disk)
 {
+	struct request_queue *q = disk->queue;
 	struct rq_qos *rqos;
 	bool disable_flag = q->elevator &&
 		    test_bit(ELEVATOR_FLAG_DISABLE_WBT, &q->elevator->flags);
@@ -718,9 +719,9 @@ static void wbt_exit(struct rq_qos *rqos)
 /*
  * Disable wbt, if enabled by default.
  */
-void wbt_disable_default(struct request_queue *q)
+void wbt_disable_default(struct gendisk *disk)
 {
-	struct rq_qos *rqos = wbt_rq_qos(q);
+	struct rq_qos *rqos = wbt_rq_qos(disk->queue);
 	struct rq_wb *rwb;
 	if (!rqos)
 		return;
diff --git a/block/blk-wbt.h b/block/blk-wbt.h
index e3ea6e7e290076..7ab1cba55c25f7 100644
--- a/block/blk-wbt.h
+++ b/block/blk-wbt.h
@@ -91,8 +91,8 @@ static inline unsigned int wbt_inflight(struct rq_wb *rwb)
 #ifdef CONFIG_BLK_WBT
 
 int wbt_init(struct request_queue *);
-void wbt_disable_default(struct request_queue *);
-void wbt_enable_default(struct request_queue *);
+void wbt_disable_default(struct gendisk *disk);
+void wbt_enable_default(struct gendisk *disk);
 
 u64 wbt_get_min_lat(struct request_queue *q);
 void wbt_set_min_lat(struct request_queue *q, u64 val);
@@ -108,10 +108,10 @@ static inline int wbt_init(struct request_queue *q)
 {
 	return -EINVAL;
 }
-static inline void wbt_disable_default(struct request_queue *q)
+static inline void wbt_disable_default(struct gendisk *disk)
 {
 }
-static inline void wbt_enable_default(struct request_queue *q)
+static inline void wbt_enable_default(struct gendisk *disk)
 {
 }
 static inline void wbt_set_write_cache(struct request_queue *q, bool wc)
-- 
2.39.0

Re: [PATCH 06/15] blk-wbt: pass a gendisk to wbt_{enable,disable}_default

[Andreas Herrmann]

On Tue, Jan 17, 2023 at 09:12:48AM +0100, Christoph Hellwig wrote:
> Pass a gendisk to wbt_enable_default and wbt_disable_default to
> prepare for phasing out usage of the request_queue in the blk-cgroup
> code.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  block/bfq-iosched.c | 4 ++--
>  block/blk-iocost.c  | 4 ++--
>  block/blk-sysfs.c   | 2 +-
>  block/blk-wbt.c     | 7 ++++---
>  block/blk-wbt.h     | 8 ++++----
>  5 files changed, 13 insertions(+), 12 deletions(-)

Looks good to me. Feel free to add
Reviewed-by: Andreas Herrmann <aherrmann@suse.de>

> diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
> index 815b884d6c5acf..68062243f2c142 100644
> --- a/block/bfq-iosched.c
> +++ b/block/bfq-iosched.c
> @@ -7165,7 +7165,7 @@ static void bfq_exit_queue(struct elevator_queue *e)
>  
>  	blk_stat_disable_accounting(bfqd->queue);
>  	clear_bit(ELEVATOR_FLAG_DISABLE_WBT, &e->flags);
> -	wbt_enable_default(bfqd->queue);
> +	wbt_enable_default(bfqd->queue->disk);
>  
>  	kfree(bfqd);
>  }
> @@ -7354,7 +7354,7 @@ static int bfq_init_queue(struct request_queue *q, struct elevator_type *e)
>  	blk_queue_flag_set(QUEUE_FLAG_SQ_SCHED, q);
>  
>  	set_bit(ELEVATOR_FLAG_DISABLE_WBT, &eq->flags);
> -	wbt_disable_default(q);
> +	wbt_disable_default(q->disk);
>  	blk_stat_enable_accounting(q);
>  
>  	return 0;
> diff --git a/block/blk-iocost.c b/block/blk-iocost.c
> index 3b965d6b037970..6f39ca99e9d76f 100644
> --- a/block/blk-iocost.c
> +++ b/block/blk-iocost.c
> @@ -3270,11 +3270,11 @@ static ssize_t ioc_qos_write(struct kernfs_open_file *of, char *input,
>  		blk_stat_enable_accounting(disk->queue);
>  		blk_queue_flag_set(QUEUE_FLAG_RQ_ALLOC_TIME, disk->queue);
>  		ioc->enabled = true;
> -		wbt_disable_default(disk->queue);
> +		wbt_disable_default(disk);
>  	} else {
>  		blk_queue_flag_clear(QUEUE_FLAG_RQ_ALLOC_TIME, disk->queue);
>  		ioc->enabled = false;
> -		wbt_enable_default(disk->queue);
> +		wbt_enable_default(disk);
>  	}
>  
>  	if (user) {
> diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
> index 5486b6c57f6b8a..2074103865f45b 100644
> --- a/block/blk-sysfs.c
> +++ b/block/blk-sysfs.c
> @@ -826,7 +826,7 @@ int blk_register_queue(struct gendisk *disk)
>  		goto out_elv_unregister;
>  
>  	blk_queue_flag_set(QUEUE_FLAG_REGISTERED, q);
> -	wbt_enable_default(q);
> +	wbt_enable_default(disk);
>  	blk_throtl_register(disk);
>  
>  	/* Now everything is ready and send out KOBJ_ADD uevent */
> diff --git a/block/blk-wbt.c b/block/blk-wbt.c
> index 68a774d7a7c9c0..8f9302134339c5 100644
> --- a/block/blk-wbt.c
> +++ b/block/blk-wbt.c
> @@ -650,8 +650,9 @@ void wbt_set_write_cache(struct request_queue *q, bool write_cache_on)
>  /*
>   * Enable wbt if defaults are configured that way
>   */
> -void wbt_enable_default(struct request_queue *q)
> +void wbt_enable_default(struct gendisk *disk)
>  {
> +	struct request_queue *q = disk->queue;
>  	struct rq_qos *rqos;
>  	bool disable_flag = q->elevator &&
>  		    test_bit(ELEVATOR_FLAG_DISABLE_WBT, &q->elevator->flags);
> @@ -718,9 +719,9 @@ static void wbt_exit(struct rq_qos *rqos)
>  /*
>   * Disable wbt, if enabled by default.
>   */
> -void wbt_disable_default(struct request_queue *q)
> +void wbt_disable_default(struct gendisk *disk)
>  {
> -	struct rq_qos *rqos = wbt_rq_qos(q);
> +	struct rq_qos *rqos = wbt_rq_qos(disk->queue);
>  	struct rq_wb *rwb;
>  	if (!rqos)
>  		return;
> diff --git a/block/blk-wbt.h b/block/blk-wbt.h
> index e3ea6e7e290076..7ab1cba55c25f7 100644
> --- a/block/blk-wbt.h
> +++ b/block/blk-wbt.h
> @@ -91,8 +91,8 @@ static inline unsigned int wbt_inflight(struct rq_wb *rwb)
>  #ifdef CONFIG_BLK_WBT
>  
>  int wbt_init(struct request_queue *);
> -void wbt_disable_default(struct request_queue *);
> -void wbt_enable_default(struct request_queue *);
> +void wbt_disable_default(struct gendisk *disk);
> +void wbt_enable_default(struct gendisk *disk);
>  
>  u64 wbt_get_min_lat(struct request_queue *q);
>  void wbt_set_min_lat(struct request_queue *q, u64 val);
> @@ -108,10 +108,10 @@ static inline int wbt_init(struct request_queue *q)
>  {
>  	return -EINVAL;
>  }
> -static inline void wbt_disable_default(struct request_queue *q)
> +static inline void wbt_disable_default(struct gendisk *disk)
>  {
>  }
> -static inline void wbt_enable_default(struct request_queue *q)
> +static inline void wbt_enable_default(struct gendisk *disk)
>  {
>  }
>  static inline void wbt_set_write_cache(struct request_queue *q, bool wc)
> -- 
> 2.39.0
> 

-- 
Regards,
Andreas

SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nürnberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Martje Boudien Moerman
(HRB 36809, AG Nürnberg)

Re: [PATCH 06/15] blk-wbt: pass a gendisk to wbt_{enable,disable}_default

[Hannes Reinecke]

On 1/17/23 09:12, Christoph Hellwig wrote:
> Pass a gendisk to wbt_enable_default and wbt_disable_default to
> prepare for phasing out usage of the request_queue in the blk-cgroup
> code.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>   block/bfq-iosched.c | 4 ++--
>   block/blk-iocost.c  | 4 ++--
>   block/blk-sysfs.c   | 2 +-
>   block/blk-wbt.c     | 7 ++++---
>   block/blk-wbt.h     | 8 ++++----
>   5 files changed, 13 insertions(+), 12 deletions(-)
> 
Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare@suse.de                              +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew
Myers, Andrew McDonald, Martje Boudien Moerman

[PATCH 07/15] blk-wbt: pass a gendisk to wbt_init

[Christoph Hellwig]

Pass a gendisk to wbt_init to prepare for phasing out usage of the
request_queue in the blk-cgroup code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-sysfs.c | 2 +-
 block/blk-wbt.c   | 5 +++--
 block/blk-wbt.h   | 4 ++--
 3 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 2074103865f45b..c2adf640e5c816 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -500,7 +500,7 @@ static ssize_t queue_wb_lat_store(struct request_queue *q, const char *page,
 
 	rqos = wbt_rq_qos(q);
 	if (!rqos) {
-		ret = wbt_init(q);
+		ret = wbt_init(q->disk);
 		if (ret)
 			return ret;
 	}
diff --git a/block/blk-wbt.c b/block/blk-wbt.c
index 8f9302134339c5..542271fa99e8f7 100644
--- a/block/blk-wbt.c
+++ b/block/blk-wbt.c
@@ -671,7 +671,7 @@ void wbt_enable_default(struct gendisk *disk)
 		return;
 
 	if (queue_is_mq(q) && !disable_flag)
-		wbt_init(q);
+		wbt_init(disk);
 }
 EXPORT_SYMBOL_GPL(wbt_enable_default);
 
@@ -835,8 +835,9 @@ static struct rq_qos_ops wbt_rqos_ops = {
 #endif
 };
 
-int wbt_init(struct request_queue *q)
+int wbt_init(struct gendisk *disk)
 {
+	struct request_queue *q = disk->queue;
 	struct rq_wb *rwb;
 	int i;
 	int ret;
diff --git a/block/blk-wbt.h b/block/blk-wbt.h
index 7ab1cba55c25f7..b673da41a867d3 100644
--- a/block/blk-wbt.h
+++ b/block/blk-wbt.h
@@ -90,7 +90,7 @@ static inline unsigned int wbt_inflight(struct rq_wb *rwb)
 
 #ifdef CONFIG_BLK_WBT
 
-int wbt_init(struct request_queue *);
+int wbt_init(struct gendisk *disk);
 void wbt_disable_default(struct gendisk *disk);
 void wbt_enable_default(struct gendisk *disk);
 
@@ -104,7 +104,7 @@ u64 wbt_default_latency_nsec(struct request_queue *);
 
 #else
 
-static inline int wbt_init(struct request_queue *q)
+static inline int wbt_init(struct gendisk *disk)
 {
 	return -EINVAL;
 }
-- 
2.39.0

Re: [PATCH 07/15] blk-wbt: pass a gendisk to wbt_init

[Andreas Herrmann]

On Tue, Jan 17, 2023 at 09:12:49AM +0100, Christoph Hellwig wrote:
> Pass a gendisk to wbt_init to prepare for phasing out usage of the
> request_queue in the blk-cgroup code.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  block/blk-sysfs.c | 2 +-
>  block/blk-wbt.c   | 5 +++--
>  block/blk-wbt.h   | 4 ++--
>  3 files changed, 6 insertions(+), 5 deletions(-)

Looks good to me. Feel free to add
Reviewed-by: Andreas Herrmann <aherrmann@suse.de>

> diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
> index 2074103865f45b..c2adf640e5c816 100644
> --- a/block/blk-sysfs.c
> +++ b/block/blk-sysfs.c
> @@ -500,7 +500,7 @@ static ssize_t queue_wb_lat_store(struct request_queue *q, const char *page,
>  
>  	rqos = wbt_rq_qos(q);
>  	if (!rqos) {
> -		ret = wbt_init(q);
> +		ret = wbt_init(q->disk);
>  		if (ret)
>  			return ret;
>  	}
> diff --git a/block/blk-wbt.c b/block/blk-wbt.c
> index 8f9302134339c5..542271fa99e8f7 100644
> --- a/block/blk-wbt.c
> +++ b/block/blk-wbt.c
> @@ -671,7 +671,7 @@ void wbt_enable_default(struct gendisk *disk)
>  		return;
>  
>  	if (queue_is_mq(q) && !disable_flag)
> -		wbt_init(q);
> +		wbt_init(disk);
>  }
>  EXPORT_SYMBOL_GPL(wbt_enable_default);
>  
> @@ -835,8 +835,9 @@ static struct rq_qos_ops wbt_rqos_ops = {
>  #endif
>  };
>  
> -int wbt_init(struct request_queue *q)
> +int wbt_init(struct gendisk *disk)
>  {
> +	struct request_queue *q = disk->queue;
>  	struct rq_wb *rwb;
>  	int i;
>  	int ret;
> diff --git a/block/blk-wbt.h b/block/blk-wbt.h
> index 7ab1cba55c25f7..b673da41a867d3 100644
> --- a/block/blk-wbt.h
> +++ b/block/blk-wbt.h
> @@ -90,7 +90,7 @@ static inline unsigned int wbt_inflight(struct rq_wb *rwb)
>  
>  #ifdef CONFIG_BLK_WBT
>  
> -int wbt_init(struct request_queue *);
> +int wbt_init(struct gendisk *disk);
>  void wbt_disable_default(struct gendisk *disk);
>  void wbt_enable_default(struct gendisk *disk);
>  
> @@ -104,7 +104,7 @@ u64 wbt_default_latency_nsec(struct request_queue *);
>  
>  #else
>  
> -static inline int wbt_init(struct request_queue *q)
> +static inline int wbt_init(struct gendisk *disk)
>  {
>  	return -EINVAL;
>  }
> -- 
> 2.39.0
> 

-- 
Regards,
Andreas

SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nürnberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Martje Boudien Moerman
(HRB 36809, AG Nürnberg)

Re: [PATCH 07/15] blk-wbt: pass a gendisk to wbt_init

[Hannes Reinecke]

On 1/17/23 09:12, Christoph Hellwig wrote:
> Pass a gendisk to wbt_init to prepare for phasing out usage of the
> request_queue in the blk-cgroup code.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>   block/blk-sysfs.c | 2 +-
>   block/blk-wbt.c   | 5 +++--
>   block/blk-wbt.h   | 4 ++--
>   3 files changed, 6 insertions(+), 5 deletions(-)
> Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare@suse.de                              +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew
Myers, Andrew McDonald, Martje Boudien Moerman

[PATCH 08/15] blk-wbt: open code wbt_queue_depth_changed in wbt_update_limits

[Christoph Hellwig]

No real need to all the method here, so open code to it to prepare
for some paramter passing changes.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-wbt.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/block/blk-wbt.c b/block/blk-wbt.c
index 542271fa99e8f7..473ae72befaf1a 100644
--- a/block/blk-wbt.c
+++ b/block/blk-wbt.c
@@ -863,9 +863,9 @@ int wbt_init(struct gendisk *disk)
 	rwb->enable_state = WBT_STATE_ON_DEFAULT;
 	rwb->wc = test_bit(QUEUE_FLAG_WC, &q->queue_flags);
 	rwb->rq_depth.default_depth = RWB_DEF_DEPTH;
+	rwb->rq_depth.queue_depth = blk_queue_depth(q);
 	rwb->min_lat_nsec = wbt_default_latency_nsec(q);
-
-	wbt_queue_depth_changed(&rwb->rqos);
+	wbt_update_limits(rwb);
 
 	/*
 	 * Assign rwb and add the stats callback.
-- 
2.39.0

Re: [PATCH 08/15] blk-wbt: open code wbt_queue_depth_changed in wbt_update_limits

[Andreas Herrmann]

On Tue, Jan 17, 2023 at 09:12:50AM +0100, Christoph Hellwig wrote:
> No real need to all the method here, so open code to it to prepare
> for some paramter passing changes.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  block/blk-wbt.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

Looks good to me. Feel free to add
Reviewed-by: Andreas Herrmann <aherrmann@suse.de>

> diff --git a/block/blk-wbt.c b/block/blk-wbt.c
> index 542271fa99e8f7..473ae72befaf1a 100644
> --- a/block/blk-wbt.c
> +++ b/block/blk-wbt.c
> @@ -863,9 +863,9 @@ int wbt_init(struct gendisk *disk)
>  	rwb->enable_state = WBT_STATE_ON_DEFAULT;
>  	rwb->wc = test_bit(QUEUE_FLAG_WC, &q->queue_flags);
>  	rwb->rq_depth.default_depth = RWB_DEF_DEPTH;
> +	rwb->rq_depth.queue_depth = blk_queue_depth(q);
>  	rwb->min_lat_nsec = wbt_default_latency_nsec(q);
> -
> -	wbt_queue_depth_changed(&rwb->rqos);
> +	wbt_update_limits(rwb);
>  
>  	/*
>  	 * Assign rwb and add the stats callback.
> -- 
> 2.39.0
> 

-- 
Regards,
Andreas

SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nürnberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Martje Boudien Moerman
(HRB 36809, AG Nürnberg)

Re: [PATCH 08/15] blk-wbt: open code wbt_queue_depth_changed in wbt_update_limits

[Hannes Reinecke]

On 1/17/23 09:12, Christoph Hellwig wrote:
> No real need to all the method here, so open code to it to prepare
> for some paramter passing changes.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>   block/blk-wbt.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/block/blk-wbt.c b/block/blk-wbt.c
> index 542271fa99e8f7..473ae72befaf1a 100644
> --- a/block/blk-wbt.c
> +++ b/block/blk-wbt.c
> @@ -863,9 +863,9 @@ int wbt_init(struct gendisk *disk)
>   	rwb->enable_state = WBT_STATE_ON_DEFAULT;
>   	rwb->wc = test_bit(QUEUE_FLAG_WC, &q->queue_flags);
>   	rwb->rq_depth.default_depth = RWB_DEF_DEPTH;
> +	rwb->rq_depth.queue_depth = blk_queue_depth(q);
>   	rwb->min_lat_nsec = wbt_default_latency_nsec(q);
> -
> -	wbt_queue_depth_changed(&rwb->rqos);
> +	wbt_update_limits(rwb);
>   
>   	/*
>   	 * Assign rwb and add the stats callback.
Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare@suse.de                              +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew
Myers, Andrew McDonald, Martje Boudien Moerman

[PATCH 09/15] blk-rq-qos: make rq_qos_add and rq_qos_del more useful

[Christoph Hellwig]

Switch to passing a gendisk, and make rq_qos_add initialize all required
fields and drop the not required q argument from rq_qos_del.  Also move
the code out of line given how large it is.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-iocost.c    | 13 ++-------
 block/blk-iolatency.c | 14 +++------
 block/blk-rq-qos.c    | 67 +++++++++++++++++++++++++++++++++++++++++++
 block/blk-rq-qos.h    | 62 ++-------------------------------------
 block/blk-wbt.c       |  5 +---
 5 files changed, 78 insertions(+), 83 deletions(-)

diff --git a/block/blk-iocost.c b/block/blk-iocost.c
index 6f39ca99e9d76f..9b5c0d23c9ce8b 100644
--- a/block/blk-iocost.c
+++ b/block/blk-iocost.c
@@ -2836,9 +2836,7 @@ static struct rq_qos_ops ioc_rqos_ops = {
 
 static int blk_iocost_init(struct gendisk *disk)
 {
-	struct request_queue *q = disk->queue;
 	struct ioc *ioc;
-	struct rq_qos *rqos;
 	int i, cpu, ret;
 
 	ioc = kzalloc(sizeof(*ioc), GFP_KERNEL);
@@ -2861,11 +2859,6 @@ static int blk_iocost_init(struct gendisk *disk)
 		local64_set(&ccs->rq_wait_ns, 0);
 	}
 
-	rqos = &ioc->rqos;
-	rqos->id = RQ_QOS_COST;
-	rqos->ops = &ioc_rqos_ops;
-	rqos->q = q;
-
 	spin_lock_init(&ioc->lock);
 	timer_setup(&ioc->timer, ioc_timer_fn, 0);
 	INIT_LIST_HEAD(&ioc->active_iocgs);
@@ -2889,17 +2882,17 @@ static int blk_iocost_init(struct gendisk *disk)
 	 * called before policy activation completion, can't assume that the
 	 * target bio has an iocg associated and need to test for NULL iocg.
 	 */
-	ret = rq_qos_add(q, rqos);
+	ret = rq_qos_add(&ioc->rqos, disk, RQ_QOS_COST, &ioc_rqos_ops);
 	if (ret)
 		goto err_free_ioc;
 
-	ret = blkcg_activate_policy(q, &blkcg_policy_iocost);
+	ret = blkcg_activate_policy(disk->queue, &blkcg_policy_iocost);
 	if (ret)
 		goto err_del_qos;
 	return 0;
 
 err_del_qos:
-	rq_qos_del(q, rqos);
+	rq_qos_del(&ioc->rqos);
 err_free_ioc:
 	free_percpu(ioc->pcpu_stat);
 	kfree(ioc);
diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c
index b55eac2cf91944..1c394bd77aa0b4 100644
--- a/block/blk-iolatency.c
+++ b/block/blk-iolatency.c
@@ -757,24 +757,18 @@ static void blkiolatency_enable_work_fn(struct work_struct *work)
 
 int blk_iolatency_init(struct gendisk *disk)
 {
-	struct request_queue *q = disk->queue;
 	struct blk_iolatency *blkiolat;
-	struct rq_qos *rqos;
 	int ret;
 
 	blkiolat = kzalloc(sizeof(*blkiolat), GFP_KERNEL);
 	if (!blkiolat)
 		return -ENOMEM;
 
-	rqos = &blkiolat->rqos;
-	rqos->id = RQ_QOS_LATENCY;
-	rqos->ops = &blkcg_iolatency_ops;
-	rqos->q = q;
-
-	ret = rq_qos_add(q, rqos);
+	ret = rq_qos_add(&blkiolat->rqos, disk, RQ_QOS_LATENCY,
+			 &blkcg_iolatency_ops);
 	if (ret)
 		goto err_free;
-	ret = blkcg_activate_policy(q, &blkcg_policy_iolatency);
+	ret = blkcg_activate_policy(disk->queue, &blkcg_policy_iolatency);
 	if (ret)
 		goto err_qos_del;
 
@@ -784,7 +778,7 @@ int blk_iolatency_init(struct gendisk *disk)
 	return 0;
 
 err_qos_del:
-	rq_qos_del(q, rqos);
+	rq_qos_del(&blkiolat->rqos);
 err_free:
 	kfree(blkiolat);
 	return ret;
diff --git a/block/blk-rq-qos.c b/block/blk-rq-qos.c
index 88f0fe7dcf5451..14bee1bd761362 100644
--- a/block/blk-rq-qos.c
+++ b/block/blk-rq-qos.c
@@ -294,3 +294,70 @@ void rq_qos_exit(struct request_queue *q)
 		rqos->ops->exit(rqos);
 	}
 }
+
+int rq_qos_add(struct rq_qos *rqos, struct gendisk *disk, enum rq_qos_id id,
+		struct rq_qos_ops *ops)
+{
+	struct request_queue *q = disk->queue;
+
+	rqos->q = q;
+	rqos->id = id;
+	rqos->ops = ops;
+
+	/*
+	 * No IO can be in-flight when adding rqos, so freeze queue, which
+	 * is fine since we only support rq_qos for blk-mq queue.
+	 *
+	 * Reuse ->queue_lock for protecting against other concurrent
+	 * rq_qos adding/deleting
+	 */
+	blk_mq_freeze_queue(q);
+
+	spin_lock_irq(&q->queue_lock);
+	if (rq_qos_id(q, rqos->id))
+		goto ebusy;
+	rqos->next = q->rq_qos;
+	q->rq_qos = rqos;
+	spin_unlock_irq(&q->queue_lock);
+
+	blk_mq_unfreeze_queue(q);
+
+	if (rqos->ops->debugfs_attrs) {
+		mutex_lock(&q->debugfs_mutex);
+		blk_mq_debugfs_register_rqos(rqos);
+		mutex_unlock(&q->debugfs_mutex);
+	}
+
+	return 0;
+ebusy:
+	spin_unlock_irq(&q->queue_lock);
+	blk_mq_unfreeze_queue(q);
+	return -EBUSY;
+}
+
+void rq_qos_del(struct rq_qos *rqos)
+{
+	struct request_queue *q = rqos->q;
+	struct rq_qos **cur;
+
+	/*
+	 * See comment in rq_qos_add() about freezing queue & using
+	 * ->queue_lock.
+	 */
+	blk_mq_freeze_queue(q);
+
+	spin_lock_irq(&q->queue_lock);
+	for (cur = &q->rq_qos; *cur; cur = &(*cur)->next) {
+		if (*cur == rqos) {
+			*cur = rqos->next;
+			break;
+		}
+	}
+	spin_unlock_irq(&q->queue_lock);
+
+	blk_mq_unfreeze_queue(q);
+
+	mutex_lock(&q->debugfs_mutex);
+	blk_mq_debugfs_unregister_rqos(rqos);
+	mutex_unlock(&q->debugfs_mutex);
+}
diff --git a/block/blk-rq-qos.h b/block/blk-rq-qos.h
index 1ef1f7d4bc3cbc..22552785aa31ed 100644
--- a/block/blk-rq-qos.h
+++ b/block/blk-rq-qos.h
@@ -85,65 +85,9 @@ static inline void rq_wait_init(struct rq_wait *rq_wait)
 	init_waitqueue_head(&rq_wait->wait);
 }
 
-static inline int rq_qos_add(struct request_queue *q, struct rq_qos *rqos)
-{
-	/*
-	 * No IO can be in-flight when adding rqos, so freeze queue, which
-	 * is fine since we only support rq_qos for blk-mq queue.
-	 *
-	 * Reuse ->queue_lock for protecting against other concurrent
-	 * rq_qos adding/deleting
-	 */
-	blk_mq_freeze_queue(q);
-
-	spin_lock_irq(&q->queue_lock);
-	if (rq_qos_id(q, rqos->id))
-		goto ebusy;
-	rqos->next = q->rq_qos;
-	q->rq_qos = rqos;
-	spin_unlock_irq(&q->queue_lock);
-
-	blk_mq_unfreeze_queue(q);
-
-	if (rqos->ops->debugfs_attrs) {
-		mutex_lock(&q->debugfs_mutex);
-		blk_mq_debugfs_register_rqos(rqos);
-		mutex_unlock(&q->debugfs_mutex);
-	}
-
-	return 0;
-ebusy:
-	spin_unlock_irq(&q->queue_lock);
-	blk_mq_unfreeze_queue(q);
-	return -EBUSY;
-
-}
-
-static inline void rq_qos_del(struct request_queue *q, struct rq_qos *rqos)
-{
-	struct rq_qos **cur;
-
-	/*
-	 * See comment in rq_qos_add() about freezing queue & using
-	 * ->queue_lock.
-	 */
-	blk_mq_freeze_queue(q);
-
-	spin_lock_irq(&q->queue_lock);
-	for (cur = &q->rq_qos; *cur; cur = &(*cur)->next) {
-		if (*cur == rqos) {
-			*cur = rqos->next;
-			break;
-		}
-	}
-	spin_unlock_irq(&q->queue_lock);
-
-	blk_mq_unfreeze_queue(q);
-
-	mutex_lock(&q->debugfs_mutex);
-	blk_mq_debugfs_unregister_rqos(rqos);
-	mutex_unlock(&q->debugfs_mutex);
-}
+int rq_qos_add(struct rq_qos *rqos, struct gendisk *disk, enum rq_qos_id id,
+		struct rq_qos_ops *ops);
+void rq_qos_del(struct rq_qos *rqos);
 
 typedef bool (acquire_inflight_cb_t)(struct rq_wait *rqw, void *private_data);
 typedef void (cleanup_cb_t)(struct rq_wait *rqw, void *private_data);
diff --git a/block/blk-wbt.c b/block/blk-wbt.c
index 473ae72befaf1a..97149a4f10e600 100644
--- a/block/blk-wbt.c
+++ b/block/blk-wbt.c
@@ -855,9 +855,6 @@ int wbt_init(struct gendisk *disk)
 	for (i = 0; i < WBT_NUM_RWQ; i++)
 		rq_wait_init(&rwb->rq_wait[i]);
 
-	rwb->rqos.id = RQ_QOS_WBT;
-	rwb->rqos.ops = &wbt_rqos_ops;
-	rwb->rqos.q = q;
 	rwb->last_comp = rwb->last_issue = jiffies;
 	rwb->win_nsec = RWB_WINDOW_NSEC;
 	rwb->enable_state = WBT_STATE_ON_DEFAULT;
@@ -870,7 +867,7 @@ int wbt_init(struct gendisk *disk)
 	/*
 	 * Assign rwb and add the stats callback.
 	 */
-	ret = rq_qos_add(q, &rwb->rqos);
+	ret = rq_qos_add(&rwb->rqos, q->disk, RQ_QOS_WBT, &wbt_rqos_ops);
 	if (ret)
 		goto err_free;
 
-- 
2.39.0

Re: [PATCH 09/15] blk-rq-qos: make rq_qos_add and rq_qos_del more useful

[Andreas Herrmann]

On Tue, Jan 17, 2023 at 09:12:51AM +0100, Christoph Hellwig wrote:
> Switch to passing a gendisk, and make rq_qos_add initialize all required
> fields and drop the not required q argument from rq_qos_del.  Also move
> the code out of line given how large it is.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  block/blk-iocost.c    | 13 ++-------
>  block/blk-iolatency.c | 14 +++------
>  block/blk-rq-qos.c    | 67 +++++++++++++++++++++++++++++++++++++++++++
>  block/blk-rq-qos.h    | 62 ++-------------------------------------
>  block/blk-wbt.c       |  5 +---
>  5 files changed, 78 insertions(+), 83 deletions(-)
> 
> diff --git a/block/blk-iocost.c b/block/blk-iocost.c
> index 6f39ca99e9d76f..9b5c0d23c9ce8b 100644
> --- a/block/blk-iocost.c
> +++ b/block/blk-iocost.c
> @@ -2836,9 +2836,7 @@ static struct rq_qos_ops ioc_rqos_ops = {
>  
>  static int blk_iocost_init(struct gendisk *disk)
>  {
> -	struct request_queue *q = disk->queue;
>  	struct ioc *ioc;
> -	struct rq_qos *rqos;
>  	int i, cpu, ret;
>  
>  	ioc = kzalloc(sizeof(*ioc), GFP_KERNEL);
> @@ -2861,11 +2859,6 @@ static int blk_iocost_init(struct gendisk *disk)
>  		local64_set(&ccs->rq_wait_ns, 0);
>  	}
>  
> -	rqos = &ioc->rqos;
> -	rqos->id = RQ_QOS_COST;
> -	rqos->ops = &ioc_rqos_ops;
> -	rqos->q = q;
> -
>  	spin_lock_init(&ioc->lock);
>  	timer_setup(&ioc->timer, ioc_timer_fn, 0);
>  	INIT_LIST_HEAD(&ioc->active_iocgs);
> @@ -2889,17 +2882,17 @@ static int blk_iocost_init(struct gendisk *disk)
>  	 * called before policy activation completion, can't assume that the
>  	 * target bio has an iocg associated and need to test for NULL iocg.
>  	 */
> -	ret = rq_qos_add(q, rqos);
> +	ret = rq_qos_add(&ioc->rqos, disk, RQ_QOS_COST, &ioc_rqos_ops);
>  	if (ret)
>  		goto err_free_ioc;
>  
> -	ret = blkcg_activate_policy(q, &blkcg_policy_iocost);
> +	ret = blkcg_activate_policy(disk->queue, &blkcg_policy_iocost);
>  	if (ret)
>  		goto err_del_qos;
>  	return 0;
>  
>  err_del_qos:
> -	rq_qos_del(q, rqos);
> +	rq_qos_del(&ioc->rqos);
>  err_free_ioc:
>  	free_percpu(ioc->pcpu_stat);
>  	kfree(ioc);
> diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c
> index b55eac2cf91944..1c394bd77aa0b4 100644
> --- a/block/blk-iolatency.c
> +++ b/block/blk-iolatency.c
> @@ -757,24 +757,18 @@ static void blkiolatency_enable_work_fn(struct work_struct *work)
>  
>  int blk_iolatency_init(struct gendisk *disk)
>  {
> -	struct request_queue *q = disk->queue;
>  	struct blk_iolatency *blkiolat;
> -	struct rq_qos *rqos;
>  	int ret;
>  
>  	blkiolat = kzalloc(sizeof(*blkiolat), GFP_KERNEL);
>  	if (!blkiolat)
>  		return -ENOMEM;
>  
> -	rqos = &blkiolat->rqos;
> -	rqos->id = RQ_QOS_LATENCY;
> -	rqos->ops = &blkcg_iolatency_ops;
> -	rqos->q = q;
> -
> -	ret = rq_qos_add(q, rqos);
> +	ret = rq_qos_add(&blkiolat->rqos, disk, RQ_QOS_LATENCY,
> +			 &blkcg_iolatency_ops);
>  	if (ret)
>  		goto err_free;
> -	ret = blkcg_activate_policy(q, &blkcg_policy_iolatency);
> +	ret = blkcg_activate_policy(disk->queue, &blkcg_policy_iolatency);
>  	if (ret)
>  		goto err_qos_del;
>  
> @@ -784,7 +778,7 @@ int blk_iolatency_init(struct gendisk *disk)
>  	return 0;
>  
>  err_qos_del:
> -	rq_qos_del(q, rqos);
> +	rq_qos_del(&blkiolat->rqos);
>  err_free:
>  	kfree(blkiolat);
>  	return ret;
> diff --git a/block/blk-rq-qos.c b/block/blk-rq-qos.c
> index 88f0fe7dcf5451..14bee1bd761362 100644
> --- a/block/blk-rq-qos.c
> +++ b/block/blk-rq-qos.c
> @@ -294,3 +294,70 @@ void rq_qos_exit(struct request_queue *q)
>  		rqos->ops->exit(rqos);
>  	}
>  }
> +
> +int rq_qos_add(struct rq_qos *rqos, struct gendisk *disk, enum rq_qos_id id,
> +		struct rq_qos_ops *ops)
> +{
> +	struct request_queue *q = disk->queue;
> +
> +	rqos->q = q;
> +	rqos->id = id;
> +	rqos->ops = ops;
> +
> +	/*
> +	 * No IO can be in-flight when adding rqos, so freeze queue, which
> +	 * is fine since we only support rq_qos for blk-mq queue.
> +	 *
> +	 * Reuse ->queue_lock for protecting against other concurrent
> +	 * rq_qos adding/deleting
> +	 */
> +	blk_mq_freeze_queue(q);
> +
> +	spin_lock_irq(&q->queue_lock);
> +	if (rq_qos_id(q, rqos->id))
> +		goto ebusy;
> +	rqos->next = q->rq_qos;
> +	q->rq_qos = rqos;
> +	spin_unlock_irq(&q->queue_lock);
> +
> +	blk_mq_unfreeze_queue(q);
> +
> +	if (rqos->ops->debugfs_attrs) {
> +		mutex_lock(&q->debugfs_mutex);
> +		blk_mq_debugfs_register_rqos(rqos);
> +		mutex_unlock(&q->debugfs_mutex);
> +	}
> +
> +	return 0;
> +ebusy:
> +	spin_unlock_irq(&q->queue_lock);
> +	blk_mq_unfreeze_queue(q);
> +	return -EBUSY;
> +}
> +
> +void rq_qos_del(struct rq_qos *rqos)
> +{
> +	struct request_queue *q = rqos->q;
> +	struct rq_qos **cur;
> +
> +	/*
> +	 * See comment in rq_qos_add() about freezing queue & using
> +	 * ->queue_lock.
> +	 */
> +	blk_mq_freeze_queue(q);
> +
> +	spin_lock_irq(&q->queue_lock);
> +	for (cur = &q->rq_qos; *cur; cur = &(*cur)->next) {
> +		if (*cur == rqos) {
> +			*cur = rqos->next;
> +			break;
> +		}
> +	}
> +	spin_unlock_irq(&q->queue_lock);
> +
> +	blk_mq_unfreeze_queue(q);
> +
> +	mutex_lock(&q->debugfs_mutex);
> +	blk_mq_debugfs_unregister_rqos(rqos);
> +	mutex_unlock(&q->debugfs_mutex);
> +}
> diff --git a/block/blk-rq-qos.h b/block/blk-rq-qos.h
> index 1ef1f7d4bc3cbc..22552785aa31ed 100644
> --- a/block/blk-rq-qos.h
> +++ b/block/blk-rq-qos.h
> @@ -85,65 +85,9 @@ static inline void rq_wait_init(struct rq_wait *rq_wait)
>  	init_waitqueue_head(&rq_wait->wait);
>  }
>  
> -static inline int rq_qos_add(struct request_queue *q, struct rq_qos *rqos)
> -{
> -	/*
> -	 * No IO can be in-flight when adding rqos, so freeze queue, which
> -	 * is fine since we only support rq_qos for blk-mq queue.
> -	 *
> -	 * Reuse ->queue_lock for protecting against other concurrent
> -	 * rq_qos adding/deleting
> -	 */
> -	blk_mq_freeze_queue(q);
> -
> -	spin_lock_irq(&q->queue_lock);
> -	if (rq_qos_id(q, rqos->id))
> -		goto ebusy;
> -	rqos->next = q->rq_qos;
> -	q->rq_qos = rqos;
> -	spin_unlock_irq(&q->queue_lock);
> -
> -	blk_mq_unfreeze_queue(q);
> -
> -	if (rqos->ops->debugfs_attrs) {
> -		mutex_lock(&q->debugfs_mutex);
> -		blk_mq_debugfs_register_rqos(rqos);
> -		mutex_unlock(&q->debugfs_mutex);
> -	}
> -
> -	return 0;
> -ebusy:
> -	spin_unlock_irq(&q->queue_lock);
> -	blk_mq_unfreeze_queue(q);
> -	return -EBUSY;
> -
> -}
> -
> -static inline void rq_qos_del(struct request_queue *q, struct rq_qos *rqos)
> -{
> -	struct rq_qos **cur;
> -
> -	/*
> -	 * See comment in rq_qos_add() about freezing queue & using
> -	 * ->queue_lock.
> -	 */
> -	blk_mq_freeze_queue(q);
> -
> -	spin_lock_irq(&q->queue_lock);
> -	for (cur = &q->rq_qos; *cur; cur = &(*cur)->next) {
> -		if (*cur == rqos) {
> -			*cur = rqos->next;
> -			break;
> -		}
> -	}
> -	spin_unlock_irq(&q->queue_lock);
> -
> -	blk_mq_unfreeze_queue(q);
> -
> -	mutex_lock(&q->debugfs_mutex);
> -	blk_mq_debugfs_unregister_rqos(rqos);
> -	mutex_unlock(&q->debugfs_mutex);
> -}
> +int rq_qos_add(struct rq_qos *rqos, struct gendisk *disk, enum rq_qos_id id,
> +		struct rq_qos_ops *ops);
> +void rq_qos_del(struct rq_qos *rqos);
>  
>  typedef bool (acquire_inflight_cb_t)(struct rq_wait *rqw, void *private_data);
>  typedef void (cleanup_cb_t)(struct rq_wait *rqw, void *private_data);
> diff --git a/block/blk-wbt.c b/block/blk-wbt.c
> index 473ae72befaf1a..97149a4f10e600 100644
> --- a/block/blk-wbt.c
> +++ b/block/blk-wbt.c
> @@ -855,9 +855,6 @@ int wbt_init(struct gendisk *disk)
>  	for (i = 0; i < WBT_NUM_RWQ; i++)
>  		rq_wait_init(&rwb->rq_wait[i]);
>  
> -	rwb->rqos.id = RQ_QOS_WBT;
> -	rwb->rqos.ops = &wbt_rqos_ops;
> -	rwb->rqos.q = q;
>  	rwb->last_comp = rwb->last_issue = jiffies;
>  	rwb->win_nsec = RWB_WINDOW_NSEC;
>  	rwb->enable_state = WBT_STATE_ON_DEFAULT;
> @@ -870,7 +867,7 @@ int wbt_init(struct gendisk *disk)
>  	/*
>  	 * Assign rwb and add the stats callback.
>  	 */
> -	ret = rq_qos_add(q, &rwb->rqos);
> +	ret = rq_qos_add(&rwb->rqos, q->disk, RQ_QOS_WBT, &wbt_rqos_ops);
                                     ^^^^^^^
				     disk (no?)
>  	if (ret)
>  		goto err_free;
>  
> -- 
> 2.39.0
> 

Otherwise looks good to me. Feel free to add
Reviewed-by: Andreas Herrmann <aherrmann@suse.de>

-- 
Regards,
Andreas

SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nürnberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Martje Boudien Moerman
(HRB 36809, AG Nürnberg)

Re: [PATCH 09/15] blk-rq-qos: make rq_qos_add and rq_qos_del more useful

[Hannes Reinecke]

On 1/17/23 09:12, Christoph Hellwig wrote:
> Switch to passing a gendisk, and make rq_qos_add initialize all required
> fields and drop the not required q argument from rq_qos_del.  Also move
> the code out of line given how large it is.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>   block/blk-iocost.c    | 13 ++-------
>   block/blk-iolatency.c | 14 +++------
>   block/blk-rq-qos.c    | 67 +++++++++++++++++++++++++++++++++++++++++++
>   block/blk-rq-qos.h    | 62 ++-------------------------------------
>   block/blk-wbt.c       |  5 +---
>   5 files changed, 78 insertions(+), 83 deletions(-)
> 
Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare@suse.de                              +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew
Myers, Andrew McDonald, Martje Boudien Moerman

[PATCH 10/15] blk-rq-qos: constify rq_qos_ops

[Christoph Hellwig]

These op vectors are constant, so mark them const.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-iocost.c    | 2 +-
 block/blk-iolatency.c | 2 +-
 block/blk-rq-qos.c    | 2 +-
 block/blk-rq-qos.h    | 4 ++--
 block/blk-wbt.c       | 2 +-
 5 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/block/blk-iocost.c b/block/blk-iocost.c
index 9b5c0d23c9ce8b..73f09e3556d7e4 100644
--- a/block/blk-iocost.c
+++ b/block/blk-iocost.c
@@ -2825,7 +2825,7 @@ static void ioc_rqos_exit(struct rq_qos *rqos)
 	kfree(ioc);
 }
 
-static struct rq_qos_ops ioc_rqos_ops = {
+static const struct rq_qos_ops ioc_rqos_ops = {
 	.throttle = ioc_rqos_throttle,
 	.merge = ioc_rqos_merge,
 	.done_bio = ioc_rqos_done_bio,
diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c
index 1c394bd77aa0b4..f6aeb3d3fdae59 100644
--- a/block/blk-iolatency.c
+++ b/block/blk-iolatency.c
@@ -650,7 +650,7 @@ static void blkcg_iolatency_exit(struct rq_qos *rqos)
 	kfree(blkiolat);
 }
 
-static struct rq_qos_ops blkcg_iolatency_ops = {
+static const struct rq_qos_ops blkcg_iolatency_ops = {
 	.throttle = blkcg_iolatency_throttle,
 	.done_bio = blkcg_iolatency_done_bio,
 	.exit = blkcg_iolatency_exit,
diff --git a/block/blk-rq-qos.c b/block/blk-rq-qos.c
index 14bee1bd761362..8e83734cfe8dbc 100644
--- a/block/blk-rq-qos.c
+++ b/block/blk-rq-qos.c
@@ -296,7 +296,7 @@ void rq_qos_exit(struct request_queue *q)
 }
 
 int rq_qos_add(struct rq_qos *rqos, struct gendisk *disk, enum rq_qos_id id,
-		struct rq_qos_ops *ops)
+		const struct rq_qos_ops *ops)
 {
 	struct request_queue *q = disk->queue;
 
diff --git a/block/blk-rq-qos.h b/block/blk-rq-qos.h
index 22552785aa31ed..2b7b668479f71a 100644
--- a/block/blk-rq-qos.h
+++ b/block/blk-rq-qos.h
@@ -25,7 +25,7 @@ struct rq_wait {
 };
 
 struct rq_qos {
-	struct rq_qos_ops *ops;
+	const struct rq_qos_ops *ops;
 	struct request_queue *q;
 	enum rq_qos_id id;
 	struct rq_qos *next;
@@ -86,7 +86,7 @@ static inline void rq_wait_init(struct rq_wait *rq_wait)
 }
 
 int rq_qos_add(struct rq_qos *rqos, struct gendisk *disk, enum rq_qos_id id,
-		struct rq_qos_ops *ops);
+		const struct rq_qos_ops *ops);
 void rq_qos_del(struct rq_qos *rqos);
 
 typedef bool (acquire_inflight_cb_t)(struct rq_wait *rqw, void *private_data);
diff --git a/block/blk-wbt.c b/block/blk-wbt.c
index 97149a4f10e600..1c4469f9962de8 100644
--- a/block/blk-wbt.c
+++ b/block/blk-wbt.c
@@ -821,7 +821,7 @@ static const struct blk_mq_debugfs_attr wbt_debugfs_attrs[] = {
 };
 #endif
 
-static struct rq_qos_ops wbt_rqos_ops = {
+static const struct rq_qos_ops wbt_rqos_ops = {
 	.throttle = wbt_wait,
 	.issue = wbt_issue,
 	.track = wbt_track,
-- 
2.39.0

Re: [PATCH 10/15] blk-rq-qos: constify rq_qos_ops

[Andreas Herrmann]

On Tue, Jan 17, 2023 at 09:12:52AM +0100, Christoph Hellwig wrote:
> These op vectors are constant, so mark them const.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  block/blk-iocost.c    | 2 +-
>  block/blk-iolatency.c | 2 +-
>  block/blk-rq-qos.c    | 2 +-
>  block/blk-rq-qos.h    | 4 ++--
>  block/blk-wbt.c       | 2 +-
>  5 files changed, 6 insertions(+), 6 deletions(-)

Looks good to me. Feel free to add
Reviewed-by: Andreas Herrmann <aherrmann@suse.de>

> diff --git a/block/blk-iocost.c b/block/blk-iocost.c
> index 9b5c0d23c9ce8b..73f09e3556d7e4 100644
> --- a/block/blk-iocost.c
> +++ b/block/blk-iocost.c
> @@ -2825,7 +2825,7 @@ static void ioc_rqos_exit(struct rq_qos *rqos)
>  	kfree(ioc);
>  }
>  
> -static struct rq_qos_ops ioc_rqos_ops = {
> +static const struct rq_qos_ops ioc_rqos_ops = {
>  	.throttle = ioc_rqos_throttle,
>  	.merge = ioc_rqos_merge,
>  	.done_bio = ioc_rqos_done_bio,
> diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c
> index 1c394bd77aa0b4..f6aeb3d3fdae59 100644
> --- a/block/blk-iolatency.c
> +++ b/block/blk-iolatency.c
> @@ -650,7 +650,7 @@ static void blkcg_iolatency_exit(struct rq_qos *rqos)
>  	kfree(blkiolat);
>  }
>  
> -static struct rq_qos_ops blkcg_iolatency_ops = {
> +static const struct rq_qos_ops blkcg_iolatency_ops = {
>  	.throttle = blkcg_iolatency_throttle,
>  	.done_bio = blkcg_iolatency_done_bio,
>  	.exit = blkcg_iolatency_exit,
> diff --git a/block/blk-rq-qos.c b/block/blk-rq-qos.c
> index 14bee1bd761362..8e83734cfe8dbc 100644
> --- a/block/blk-rq-qos.c
> +++ b/block/blk-rq-qos.c
> @@ -296,7 +296,7 @@ void rq_qos_exit(struct request_queue *q)
>  }
>  
>  int rq_qos_add(struct rq_qos *rqos, struct gendisk *disk, enum rq_qos_id id,
> -		struct rq_qos_ops *ops)
> +		const struct rq_qos_ops *ops)
>  {
>  	struct request_queue *q = disk->queue;
>  
> diff --git a/block/blk-rq-qos.h b/block/blk-rq-qos.h
> index 22552785aa31ed..2b7b668479f71a 100644
> --- a/block/blk-rq-qos.h
> +++ b/block/blk-rq-qos.h
> @@ -25,7 +25,7 @@ struct rq_wait {
>  };
>  
>  struct rq_qos {
> -	struct rq_qos_ops *ops;
> +	const struct rq_qos_ops *ops;
>  	struct request_queue *q;
>  	enum rq_qos_id id;
>  	struct rq_qos *next;
> @@ -86,7 +86,7 @@ static inline void rq_wait_init(struct rq_wait *rq_wait)
>  }
>  
>  int rq_qos_add(struct rq_qos *rqos, struct gendisk *disk, enum rq_qos_id id,
> -		struct rq_qos_ops *ops);
> +		const struct rq_qos_ops *ops);
>  void rq_qos_del(struct rq_qos *rqos);
>  
>  typedef bool (acquire_inflight_cb_t)(struct rq_wait *rqw, void *private_data);
> diff --git a/block/blk-wbt.c b/block/blk-wbt.c
> index 97149a4f10e600..1c4469f9962de8 100644
> --- a/block/blk-wbt.c
> +++ b/block/blk-wbt.c
> @@ -821,7 +821,7 @@ static const struct blk_mq_debugfs_attr wbt_debugfs_attrs[] = {
>  };
>  #endif
>  
> -static struct rq_qos_ops wbt_rqos_ops = {
> +static const struct rq_qos_ops wbt_rqos_ops = {
>  	.throttle = wbt_wait,
>  	.issue = wbt_issue,
>  	.track = wbt_track,
> -- 
> 2.39.0
> 

-- 
Regards,
Andreas

SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nürnberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Martje Boudien Moerman
(HRB 36809, AG Nürnberg)

Re: [PATCH 10/15] blk-rq-qos: constify rq_qos_ops

[Hannes Reinecke]

On 1/17/23 09:12, Christoph Hellwig wrote:
> These op vectors are constant, so mark them const.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>   block/blk-iocost.c    | 2 +-
>   block/blk-iolatency.c | 2 +-
>   block/blk-rq-qos.c    | 2 +-
>   block/blk-rq-qos.h    | 4 ++--
>   block/blk-wbt.c       | 2 +-
>   5 files changed, 6 insertions(+), 6 deletions(-)
> 
Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare@suse.de                              +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew
Myers, Andrew McDonald, Martje Boudien Moerman

[PATCH 11/15] blk-rq-qos: store a gendisk instead of request_queue in struct rq_qos

[Christoph Hellwig]

This is what about half of the users already want, and it's only going to
grow more.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-iocost.c     | 12 ++++++------
 block/blk-iolatency.c  | 14 +++++++-------
 block/blk-mq-debugfs.c | 10 ++++------
 block/blk-rq-qos.c     |  4 ++--
 block/blk-rq-qos.h     |  2 +-
 block/blk-wbt.c        | 16 +++++++---------
 6 files changed, 27 insertions(+), 31 deletions(-)

diff --git a/block/blk-iocost.c b/block/blk-iocost.c
index 73f09e3556d7e4..54e42b22b3599f 100644
--- a/block/blk-iocost.c
+++ b/block/blk-iocost.c
@@ -667,7 +667,7 @@ static struct ioc *q_to_ioc(struct request_queue *q)
 
 static const char __maybe_unused *ioc_name(struct ioc *ioc)
 {
-	struct gendisk *disk = ioc->rqos.q->disk;
+	struct gendisk *disk = ioc->rqos.disk;
 
 	if (!disk)
 		return "<unknown>";
@@ -806,11 +806,11 @@ static int ioc_autop_idx(struct ioc *ioc)
 	u64 now_ns;
 
 	/* rotational? */
-	if (!blk_queue_nonrot(ioc->rqos.q))
+	if (!blk_queue_nonrot(ioc->rqos.disk->queue))
 		return AUTOP_HDD;
 
 	/* handle SATA SSDs w/ broken NCQ */
-	if (blk_queue_depth(ioc->rqos.q) == 1)
+	if (blk_queue_depth(ioc->rqos.disk->queue) == 1)
 		return AUTOP_SSD_QD1;
 
 	/* use one of the normal ssd sets */
@@ -2642,7 +2642,7 @@ static void ioc_rqos_throttle(struct rq_qos *rqos, struct bio *bio)
 	if (use_debt) {
 		iocg_incur_debt(iocg, abs_cost, &now);
 		if (iocg_kick_delay(iocg, &now))
-			blkcg_schedule_throttle(rqos->q->disk,
+			blkcg_schedule_throttle(rqos->disk,
 					(bio->bi_opf & REQ_SWAP) == REQ_SWAP);
 		iocg_unlock(iocg, ioc_locked, &flags);
 		return;
@@ -2743,7 +2743,7 @@ static void ioc_rqos_merge(struct rq_qos *rqos, struct request *rq,
 	if (likely(!list_empty(&iocg->active_list))) {
 		iocg_incur_debt(iocg, abs_cost, &now);
 		if (iocg_kick_delay(iocg, &now))
-			blkcg_schedule_throttle(rqos->q->disk,
+			blkcg_schedule_throttle(rqos->disk,
 					(bio->bi_opf & REQ_SWAP) == REQ_SWAP);
 	} else {
 		iocg_commit_bio(iocg, bio, abs_cost, cost);
@@ -2814,7 +2814,7 @@ static void ioc_rqos_exit(struct rq_qos *rqos)
 {
 	struct ioc *ioc = rqos_to_ioc(rqos);
 
-	blkcg_deactivate_policy(rqos->q, &blkcg_policy_iocost);
+	blkcg_deactivate_policy(rqos->disk->queue, &blkcg_policy_iocost);
 
 	spin_lock_irq(&ioc->lock);
 	ioc->running = IOC_STOP;
diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c
index f6aeb3d3fdae59..8e1e43bbde6f0b 100644
--- a/block/blk-iolatency.c
+++ b/block/blk-iolatency.c
@@ -292,7 +292,7 @@ static void __blkcg_iolatency_throttle(struct rq_qos *rqos,
 	unsigned use_delay = atomic_read(&lat_to_blkg(iolat)->use_delay);
 
 	if (use_delay)
-		blkcg_schedule_throttle(rqos->q->disk, use_memdelay);
+		blkcg_schedule_throttle(rqos->disk, use_memdelay);
 
 	/*
 	 * To avoid priority inversions we want to just take a slot if we are
@@ -330,7 +330,7 @@ static void scale_cookie_change(struct blk_iolatency *blkiolat,
 				struct child_latency_info *lat_info,
 				bool up)
 {
-	unsigned long qd = blkiolat->rqos.q->nr_requests;
+	unsigned long qd = blkiolat->rqos.disk->queue->nr_requests;
 	unsigned long scale = scale_amount(qd, up);
 	unsigned long old = atomic_read(&lat_info->scale_cookie);
 	unsigned long max_scale = qd << 1;
@@ -372,7 +372,7 @@ static void scale_cookie_change(struct blk_iolatency *blkiolat,
  */
 static void scale_change(struct iolatency_grp *iolat, bool up)
 {
-	unsigned long qd = iolat->blkiolat->rqos.q->nr_requests;
+	unsigned long qd = iolat->blkiolat->rqos.disk->queue->nr_requests;
 	unsigned long scale = scale_amount(qd, up);
 	unsigned long old = iolat->max_depth;
 
@@ -646,7 +646,7 @@ static void blkcg_iolatency_exit(struct rq_qos *rqos)
 
 	timer_shutdown_sync(&blkiolat->timer);
 	flush_work(&blkiolat->enable_work);
-	blkcg_deactivate_policy(rqos->q, &blkcg_policy_iolatency);
+	blkcg_deactivate_policy(rqos->disk->queue, &blkcg_policy_iolatency);
 	kfree(blkiolat);
 }
 
@@ -665,7 +665,7 @@ static void blkiolatency_timer_fn(struct timer_list *t)
 
 	rcu_read_lock();
 	blkg_for_each_descendant_pre(blkg, pos_css,
-				     blkiolat->rqos.q->root_blkg) {
+				     blkiolat->rqos.disk->queue->root_blkg) {
 		struct iolatency_grp *iolat;
 		struct child_latency_info *lat_info;
 		unsigned long flags;
@@ -749,9 +749,9 @@ static void blkiolatency_enable_work_fn(struct work_struct *work)
 	 */
 	enabled = atomic_read(&blkiolat->enable_cnt);
 	if (enabled != blkiolat->enabled) {
-		blk_mq_freeze_queue(blkiolat->rqos.q);
+		blk_mq_freeze_queue(blkiolat->rqos.disk->queue);
 		blkiolat->enabled = enabled;
-		blk_mq_unfreeze_queue(blkiolat->rqos.q);
+		blk_mq_unfreeze_queue(blkiolat->rqos.disk->queue);
 	}
 }
 
diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
index bd942341b6382f..b01818f8e216e3 100644
--- a/block/blk-mq-debugfs.c
+++ b/block/blk-mq-debugfs.c
@@ -813,9 +813,9 @@ static const char *rq_qos_id_to_name(enum rq_qos_id id)
 
 void blk_mq_debugfs_unregister_rqos(struct rq_qos *rqos)
 {
-	lockdep_assert_held(&rqos->q->debugfs_mutex);
+	lockdep_assert_held(&rqos->disk->queue->debugfs_mutex);
 
-	if (!rqos->q->debugfs_dir)
+	if (!rqos->disk->queue->debugfs_dir)
 		return;
 	debugfs_remove_recursive(rqos->debugfs_dir);
 	rqos->debugfs_dir = NULL;
@@ -823,7 +823,7 @@ void blk_mq_debugfs_unregister_rqos(struct rq_qos *rqos)
 
 void blk_mq_debugfs_register_rqos(struct rq_qos *rqos)
 {
-	struct request_queue *q = rqos->q;
+	struct request_queue *q = rqos->disk->queue;
 	const char *dir_name = rq_qos_id_to_name(rqos->id);
 
 	lockdep_assert_held(&q->debugfs_mutex);
@@ -835,9 +835,7 @@ void blk_mq_debugfs_register_rqos(struct rq_qos *rqos)
 		q->rqos_debugfs_dir = debugfs_create_dir("rqos",
 							 q->debugfs_dir);
 
-	rqos->debugfs_dir = debugfs_create_dir(dir_name,
-					       rqos->q->rqos_debugfs_dir);
-
+	rqos->debugfs_dir = debugfs_create_dir(dir_name, q->rqos_debugfs_dir);
 	debugfs_create_files(rqos->debugfs_dir, rqos, rqos->ops->debugfs_attrs);
 }
 
diff --git a/block/blk-rq-qos.c b/block/blk-rq-qos.c
index 8e83734cfe8dbc..d8cc820a365e3a 100644
--- a/block/blk-rq-qos.c
+++ b/block/blk-rq-qos.c
@@ -300,7 +300,7 @@ int rq_qos_add(struct rq_qos *rqos, struct gendisk *disk, enum rq_qos_id id,
 {
 	struct request_queue *q = disk->queue;
 
-	rqos->q = q;
+	rqos->disk = disk;
 	rqos->id = id;
 	rqos->ops = ops;
 
@@ -337,7 +337,7 @@ int rq_qos_add(struct rq_qos *rqos, struct gendisk *disk, enum rq_qos_id id,
 
 void rq_qos_del(struct rq_qos *rqos)
 {
-	struct request_queue *q = rqos->q;
+	struct request_queue *q = rqos->disk->queue;
 	struct rq_qos **cur;
 
 	/*
diff --git a/block/blk-rq-qos.h b/block/blk-rq-qos.h
index 2b7b668479f71a..b02a1a3d33a89e 100644
--- a/block/blk-rq-qos.h
+++ b/block/blk-rq-qos.h
@@ -26,7 +26,7 @@ struct rq_wait {
 
 struct rq_qos {
 	const struct rq_qos_ops *ops;
-	struct request_queue *q;
+	struct gendisk *disk;
 	enum rq_qos_id id;
 	struct rq_qos *next;
 #ifdef CONFIG_BLK_DEBUG_FS
diff --git a/block/blk-wbt.c b/block/blk-wbt.c
index 1c4469f9962de8..73822260be537c 100644
--- a/block/blk-wbt.c
+++ b/block/blk-wbt.c
@@ -98,7 +98,7 @@ static void wb_timestamp(struct rq_wb *rwb, unsigned long *var)
  */
 static bool wb_recent_wait(struct rq_wb *rwb)
 {
-	struct bdi_writeback *wb = &rwb->rqos.q->disk->bdi->wb;
+	struct bdi_writeback *wb = &rwb->rqos.disk->bdi->wb;
 
 	return time_before(jiffies, wb->dirty_sleep + HZ);
 }
@@ -235,7 +235,7 @@ enum {
 
 static int latency_exceeded(struct rq_wb *rwb, struct blk_rq_stat *stat)
 {
-	struct backing_dev_info *bdi = rwb->rqos.q->disk->bdi;
+	struct backing_dev_info *bdi = rwb->rqos.disk->bdi;
 	struct rq_depth *rqd = &rwb->rq_depth;
 	u64 thislat;
 
@@ -288,7 +288,7 @@ static int latency_exceeded(struct rq_wb *rwb, struct blk_rq_stat *stat)
 
 static void rwb_trace_step(struct rq_wb *rwb, const char *msg)
 {
-	struct backing_dev_info *bdi = rwb->rqos.q->disk->bdi;
+	struct backing_dev_info *bdi = rwb->rqos.disk->bdi;
 	struct rq_depth *rqd = &rwb->rq_depth;
 
 	trace_wbt_step(bdi, msg, rqd->scale_step, rwb->cur_win_nsec,
@@ -358,13 +358,12 @@ static void wb_timer_fn(struct blk_stat_callback *cb)
 	unsigned int inflight = wbt_inflight(rwb);
 	int status;
 
-	if (!rwb->rqos.q->disk)
+	if (!rwb->rqos.disk)
 		return;
 
 	status = latency_exceeded(rwb, cb->stat);
 
-	trace_wbt_timer(rwb->rqos.q->disk->bdi, status, rqd->scale_step,
-			inflight);
+	trace_wbt_timer(rwb->rqos.disk->bdi, status, rqd->scale_step, inflight);
 
 	/*
 	 * If we exceeded the latency target, step down. If we did not,
@@ -702,16 +701,15 @@ static int wbt_data_dir(const struct request *rq)
 
 static void wbt_queue_depth_changed(struct rq_qos *rqos)
 {
-	RQWB(rqos)->rq_depth.queue_depth = blk_queue_depth(rqos->q);
+	RQWB(rqos)->rq_depth.queue_depth = blk_queue_depth(rqos->disk->queue);
 	wbt_update_limits(RQWB(rqos));
 }
 
 static void wbt_exit(struct rq_qos *rqos)
 {
 	struct rq_wb *rwb = RQWB(rqos);
-	struct request_queue *q = rqos->q;
 
-	blk_stat_remove_callback(q, rwb->cb);
+	blk_stat_remove_callback(rqos->disk->queue, rwb->cb);
 	blk_stat_free_callback(rwb->cb);
 	kfree(rwb);
 }
-- 
2.39.0

Re: [PATCH 11/15] blk-rq-qos: store a gendisk instead of request_queue in struct rq_qos

[Andreas Herrmann]

On Tue, Jan 17, 2023 at 09:12:53AM +0100, Christoph Hellwig wrote:
> This is what about half of the users already want, and it's only going to
> grow more.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  block/blk-iocost.c     | 12 ++++++------
>  block/blk-iolatency.c  | 14 +++++++-------
>  block/blk-mq-debugfs.c | 10 ++++------
>  block/blk-rq-qos.c     |  4 ++--
>  block/blk-rq-qos.h     |  2 +-
>  block/blk-wbt.c        | 16 +++++++---------
>  6 files changed, 27 insertions(+), 31 deletions(-)

Looks good to me. Feel free to add
Reviewed-by: Andreas Herrmann <aherrmann@suse.de>

> diff --git a/block/blk-iocost.c b/block/blk-iocost.c
> index 73f09e3556d7e4..54e42b22b3599f 100644
> --- a/block/blk-iocost.c
> +++ b/block/blk-iocost.c
> @@ -667,7 +667,7 @@ static struct ioc *q_to_ioc(struct request_queue *q)
>  
>  static const char __maybe_unused *ioc_name(struct ioc *ioc)
>  {
> -	struct gendisk *disk = ioc->rqos.q->disk;
> +	struct gendisk *disk = ioc->rqos.disk;
>  
>  	if (!disk)
>  		return "<unknown>";
> @@ -806,11 +806,11 @@ static int ioc_autop_idx(struct ioc *ioc)
>  	u64 now_ns;
>  
>  	/* rotational? */
> -	if (!blk_queue_nonrot(ioc->rqos.q))
> +	if (!blk_queue_nonrot(ioc->rqos.disk->queue))
>  		return AUTOP_HDD;
>  
>  	/* handle SATA SSDs w/ broken NCQ */
> -	if (blk_queue_depth(ioc->rqos.q) == 1)
> +	if (blk_queue_depth(ioc->rqos.disk->queue) == 1)
>  		return AUTOP_SSD_QD1;
>  
>  	/* use one of the normal ssd sets */
> @@ -2642,7 +2642,7 @@ static void ioc_rqos_throttle(struct rq_qos *rqos, struct bio *bio)
>  	if (use_debt) {
>  		iocg_incur_debt(iocg, abs_cost, &now);
>  		if (iocg_kick_delay(iocg, &now))
> -			blkcg_schedule_throttle(rqos->q->disk,
> +			blkcg_schedule_throttle(rqos->disk,
>  					(bio->bi_opf & REQ_SWAP) == REQ_SWAP);
>  		iocg_unlock(iocg, ioc_locked, &flags);
>  		return;
> @@ -2743,7 +2743,7 @@ static void ioc_rqos_merge(struct rq_qos *rqos, struct request *rq,
>  	if (likely(!list_empty(&iocg->active_list))) {
>  		iocg_incur_debt(iocg, abs_cost, &now);
>  		if (iocg_kick_delay(iocg, &now))
> -			blkcg_schedule_throttle(rqos->q->disk,
> +			blkcg_schedule_throttle(rqos->disk,
>  					(bio->bi_opf & REQ_SWAP) == REQ_SWAP);
>  	} else {
>  		iocg_commit_bio(iocg, bio, abs_cost, cost);
> @@ -2814,7 +2814,7 @@ static void ioc_rqos_exit(struct rq_qos *rqos)
>  {
>  	struct ioc *ioc = rqos_to_ioc(rqos);
>  
> -	blkcg_deactivate_policy(rqos->q, &blkcg_policy_iocost);
> +	blkcg_deactivate_policy(rqos->disk->queue, &blkcg_policy_iocost);
>  
>  	spin_lock_irq(&ioc->lock);
>  	ioc->running = IOC_STOP;
> diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c
> index f6aeb3d3fdae59..8e1e43bbde6f0b 100644
> --- a/block/blk-iolatency.c
> +++ b/block/blk-iolatency.c
> @@ -292,7 +292,7 @@ static void __blkcg_iolatency_throttle(struct rq_qos *rqos,
>  	unsigned use_delay = atomic_read(&lat_to_blkg(iolat)->use_delay);
>  
>  	if (use_delay)
> -		blkcg_schedule_throttle(rqos->q->disk, use_memdelay);
> +		blkcg_schedule_throttle(rqos->disk, use_memdelay);
>  
>  	/*
>  	 * To avoid priority inversions we want to just take a slot if we are
> @@ -330,7 +330,7 @@ static void scale_cookie_change(struct blk_iolatency *blkiolat,
>  				struct child_latency_info *lat_info,
>  				bool up)
>  {
> -	unsigned long qd = blkiolat->rqos.q->nr_requests;
> +	unsigned long qd = blkiolat->rqos.disk->queue->nr_requests;
>  	unsigned long scale = scale_amount(qd, up);
>  	unsigned long old = atomic_read(&lat_info->scale_cookie);
>  	unsigned long max_scale = qd << 1;
> @@ -372,7 +372,7 @@ static void scale_cookie_change(struct blk_iolatency *blkiolat,
>   */
>  static void scale_change(struct iolatency_grp *iolat, bool up)
>  {
> -	unsigned long qd = iolat->blkiolat->rqos.q->nr_requests;
> +	unsigned long qd = iolat->blkiolat->rqos.disk->queue->nr_requests;
>  	unsigned long scale = scale_amount(qd, up);
>  	unsigned long old = iolat->max_depth;
>  
> @@ -646,7 +646,7 @@ static void blkcg_iolatency_exit(struct rq_qos *rqos)
>  
>  	timer_shutdown_sync(&blkiolat->timer);
>  	flush_work(&blkiolat->enable_work);
> -	blkcg_deactivate_policy(rqos->q, &blkcg_policy_iolatency);
> +	blkcg_deactivate_policy(rqos->disk->queue, &blkcg_policy_iolatency);
>  	kfree(blkiolat);
>  }
>  
> @@ -665,7 +665,7 @@ static void blkiolatency_timer_fn(struct timer_list *t)
>  
>  	rcu_read_lock();
>  	blkg_for_each_descendant_pre(blkg, pos_css,
> -				     blkiolat->rqos.q->root_blkg) {
> +				     blkiolat->rqos.disk->queue->root_blkg) {
>  		struct iolatency_grp *iolat;
>  		struct child_latency_info *lat_info;
>  		unsigned long flags;
> @@ -749,9 +749,9 @@ static void blkiolatency_enable_work_fn(struct work_struct *work)
>  	 */
>  	enabled = atomic_read(&blkiolat->enable_cnt);
>  	if (enabled != blkiolat->enabled) {
> -		blk_mq_freeze_queue(blkiolat->rqos.q);
> +		blk_mq_freeze_queue(blkiolat->rqos.disk->queue);
>  		blkiolat->enabled = enabled;
> -		blk_mq_unfreeze_queue(blkiolat->rqos.q);
> +		blk_mq_unfreeze_queue(blkiolat->rqos.disk->queue);
>  	}
>  }
>  
> diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
> index bd942341b6382f..b01818f8e216e3 100644
> --- a/block/blk-mq-debugfs.c
> +++ b/block/blk-mq-debugfs.c
> @@ -813,9 +813,9 @@ static const char *rq_qos_id_to_name(enum rq_qos_id id)
>  
>  void blk_mq_debugfs_unregister_rqos(struct rq_qos *rqos)
>  {
> -	lockdep_assert_held(&rqos->q->debugfs_mutex);
> +	lockdep_assert_held(&rqos->disk->queue->debugfs_mutex);
>  
> -	if (!rqos->q->debugfs_dir)
> +	if (!rqos->disk->queue->debugfs_dir)
>  		return;
>  	debugfs_remove_recursive(rqos->debugfs_dir);
>  	rqos->debugfs_dir = NULL;
> @@ -823,7 +823,7 @@ void blk_mq_debugfs_unregister_rqos(struct rq_qos *rqos)
>  
>  void blk_mq_debugfs_register_rqos(struct rq_qos *rqos)
>  {
> -	struct request_queue *q = rqos->q;
> +	struct request_queue *q = rqos->disk->queue;
>  	const char *dir_name = rq_qos_id_to_name(rqos->id);
>  
>  	lockdep_assert_held(&q->debugfs_mutex);
> @@ -835,9 +835,7 @@ void blk_mq_debugfs_register_rqos(struct rq_qos *rqos)
>  		q->rqos_debugfs_dir = debugfs_create_dir("rqos",
>  							 q->debugfs_dir);
>  
> -	rqos->debugfs_dir = debugfs_create_dir(dir_name,
> -					       rqos->q->rqos_debugfs_dir);
> -
> +	rqos->debugfs_dir = debugfs_create_dir(dir_name, q->rqos_debugfs_dir);
>  	debugfs_create_files(rqos->debugfs_dir, rqos, rqos->ops->debugfs_attrs);
>  }
>  
> diff --git a/block/blk-rq-qos.c b/block/blk-rq-qos.c
> index 8e83734cfe8dbc..d8cc820a365e3a 100644
> --- a/block/blk-rq-qos.c
> +++ b/block/blk-rq-qos.c
> @@ -300,7 +300,7 @@ int rq_qos_add(struct rq_qos *rqos, struct gendisk *disk, enum rq_qos_id id,
>  {
>  	struct request_queue *q = disk->queue;
>  
> -	rqos->q = q;
> +	rqos->disk = disk;
>  	rqos->id = id;
>  	rqos->ops = ops;
>  
> @@ -337,7 +337,7 @@ int rq_qos_add(struct rq_qos *rqos, struct gendisk *disk, enum rq_qos_id id,
>  
>  void rq_qos_del(struct rq_qos *rqos)
>  {
> -	struct request_queue *q = rqos->q;
> +	struct request_queue *q = rqos->disk->queue;
>  	struct rq_qos **cur;
>  
>  	/*
> diff --git a/block/blk-rq-qos.h b/block/blk-rq-qos.h
> index 2b7b668479f71a..b02a1a3d33a89e 100644
> --- a/block/blk-rq-qos.h
> +++ b/block/blk-rq-qos.h
> @@ -26,7 +26,7 @@ struct rq_wait {
>  
>  struct rq_qos {
>  	const struct rq_qos_ops *ops;
> -	struct request_queue *q;
> +	struct gendisk *disk;
>  	enum rq_qos_id id;
>  	struct rq_qos *next;
>  #ifdef CONFIG_BLK_DEBUG_FS
> diff --git a/block/blk-wbt.c b/block/blk-wbt.c
> index 1c4469f9962de8..73822260be537c 100644
> --- a/block/blk-wbt.c
> +++ b/block/blk-wbt.c
> @@ -98,7 +98,7 @@ static void wb_timestamp(struct rq_wb *rwb, unsigned long *var)
>   */
>  static bool wb_recent_wait(struct rq_wb *rwb)
>  {
> -	struct bdi_writeback *wb = &rwb->rqos.q->disk->bdi->wb;
> +	struct bdi_writeback *wb = &rwb->rqos.disk->bdi->wb;
>  
>  	return time_before(jiffies, wb->dirty_sleep + HZ);
>  }
> @@ -235,7 +235,7 @@ enum {
>  
>  static int latency_exceeded(struct rq_wb *rwb, struct blk_rq_stat *stat)
>  {
> -	struct backing_dev_info *bdi = rwb->rqos.q->disk->bdi;
> +	struct backing_dev_info *bdi = rwb->rqos.disk->bdi;
>  	struct rq_depth *rqd = &rwb->rq_depth;
>  	u64 thislat;
>  
> @@ -288,7 +288,7 @@ static int latency_exceeded(struct rq_wb *rwb, struct blk_rq_stat *stat)
>  
>  static void rwb_trace_step(struct rq_wb *rwb, const char *msg)
>  {
> -	struct backing_dev_info *bdi = rwb->rqos.q->disk->bdi;
> +	struct backing_dev_info *bdi = rwb->rqos.disk->bdi;
>  	struct rq_depth *rqd = &rwb->rq_depth;
>  
>  	trace_wbt_step(bdi, msg, rqd->scale_step, rwb->cur_win_nsec,
> @@ -358,13 +358,12 @@ static void wb_timer_fn(struct blk_stat_callback *cb)
>  	unsigned int inflight = wbt_inflight(rwb);
>  	int status;
>  
> -	if (!rwb->rqos.q->disk)
> +	if (!rwb->rqos.disk)
>  		return;
>  
>  	status = latency_exceeded(rwb, cb->stat);
>  
> -	trace_wbt_timer(rwb->rqos.q->disk->bdi, status, rqd->scale_step,
> -			inflight);
> +	trace_wbt_timer(rwb->rqos.disk->bdi, status, rqd->scale_step, inflight);
>  
>  	/*
>  	 * If we exceeded the latency target, step down. If we did not,
> @@ -702,16 +701,15 @@ static int wbt_data_dir(const struct request *rq)
>  
>  static void wbt_queue_depth_changed(struct rq_qos *rqos)
>  {
> -	RQWB(rqos)->rq_depth.queue_depth = blk_queue_depth(rqos->q);
> +	RQWB(rqos)->rq_depth.queue_depth = blk_queue_depth(rqos->disk->queue);
>  	wbt_update_limits(RQWB(rqos));
>  }
>  
>  static void wbt_exit(struct rq_qos *rqos)
>  {
>  	struct rq_wb *rwb = RQWB(rqos);
> -	struct request_queue *q = rqos->q;
>  
> -	blk_stat_remove_callback(q, rwb->cb);
> +	blk_stat_remove_callback(rqos->disk->queue, rwb->cb);
>  	blk_stat_free_callback(rwb->cb);
>  	kfree(rwb);
>  }
> -- 
> 2.39.0
> 

-- 
Regards,
Andreas

SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nürnberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Martje Boudien Moerman
(HRB 36809, AG Nürnberg)

Re: [PATCH 11/15] blk-rq-qos: store a gendisk instead of request_queue in struct rq_qos

[Hannes Reinecke]

On 1/17/23 09:12, Christoph Hellwig wrote:
> This is what about half of the users already want, and it's only going to
> grow more.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>   block/blk-iocost.c     | 12 ++++++------
>   block/blk-iolatency.c  | 14 +++++++-------
>   block/blk-mq-debugfs.c | 10 ++++------
>   block/blk-rq-qos.c     |  4 ++--
>   block/blk-rq-qos.h     |  2 +-
>   block/blk-wbt.c        | 16 +++++++---------
>   6 files changed, 27 insertions(+), 31 deletions(-)
> Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare@suse.de                              +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew
Myers, Andrew McDonald, Martje Boudien Moerman

[PATCH 12/15] blk-cgroup: pass a gendisk to blkcg_{de,}activate_policy

[Christoph Hellwig]

Prepare for storing the blkcg information in the gendisk instead of
the request_queue.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/bfq-cgroup.c    |  2 +-
 block/bfq-iosched.c   |  2 +-
 block/blk-cgroup.c    | 19 ++++++++++---------
 block/blk-cgroup.h    |  9 ++++-----
 block/blk-iocost.c    |  4 ++--
 block/blk-iolatency.c |  4 ++--
 block/blk-ioprio.c    |  4 ++--
 block/blk-throttle.c  |  4 ++--
 8 files changed, 24 insertions(+), 24 deletions(-)

diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c
index 72a033776722c9..b1b8eca99d988f 100644
--- a/block/bfq-cgroup.c
+++ b/block/bfq-cgroup.c
@@ -1293,7 +1293,7 @@ struct bfq_group *bfq_create_group_hierarchy(struct bfq_data *bfqd, int node)
 {
 	int ret;
 
-	ret = blkcg_activate_policy(bfqd->queue, &blkcg_policy_bfq);
+	ret = blkcg_activate_policy(bfqd->queue->disk, &blkcg_policy_bfq);
 	if (ret)
 		return NULL;
 
diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index 68062243f2c142..eda3a838f3c3fd 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -7155,7 +7155,7 @@ static void bfq_exit_queue(struct elevator_queue *e)
 	bfqg_and_blkg_put(bfqd->root_group);
 
 #ifdef CONFIG_BFQ_GROUP_IOSCHED
-	blkcg_deactivate_policy(bfqd->queue, &blkcg_policy_bfq);
+	blkcg_deactivate_policy(bfqd->queue->disk, &blkcg_policy_bfq);
 #else
 	spin_lock_irq(&bfqd->lock);
 	bfq_put_async_queues(bfqd, bfqd->root_group);
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 603e911d1350db..353421afe1d70d 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -1363,13 +1363,13 @@ EXPORT_SYMBOL_GPL(io_cgrp_subsys);
 
 /**
  * blkcg_activate_policy - activate a blkcg policy on a request_queue
- * @q: request_queue of interest
+ * @disk: gendisk of interest
  * @pol: blkcg policy to activate
  *
- * Activate @pol on @q.  Requires %GFP_KERNEL context.  @q goes through
+ * Activate @pol on @disk.  Requires %GFP_KERNEL context.  @disk goes through
  * bypass mode to populate its blkgs with policy_data for @pol.
  *
- * Activation happens with @q bypassed, so nobody would be accessing blkgs
+ * Activation happens with @disk bypassed, so nobody would be accessing blkgs
  * from IO path.  Update of each blkg is protected by both queue and blkcg
  * locks so that holding either lock and testing blkcg_policy_enabled() is
  * always enough for dereferencing policy data.
@@ -1377,9 +1377,9 @@ EXPORT_SYMBOL_GPL(io_cgrp_subsys);
  * The caller is responsible for synchronizing [de]activations and policy
  * [un]registerations.  Returns 0 on success, -errno on failure.
  */
-int blkcg_activate_policy(struct request_queue *q,
-			  const struct blkcg_policy *pol)
+int blkcg_activate_policy(struct gendisk *disk, const struct blkcg_policy *pol)
 {
+	struct request_queue *q = disk->queue;
 	struct blkg_policy_data *pd_prealloc = NULL;
 	struct blkcg_gq *blkg, *pinned_blkg = NULL;
 	int ret;
@@ -1473,16 +1473,17 @@ int blkcg_activate_policy(struct request_queue *q,
 EXPORT_SYMBOL_GPL(blkcg_activate_policy);
 
 /**
- * blkcg_deactivate_policy - deactivate a blkcg policy on a request_queue
- * @q: request_queue of interest
+ * blkcg_deactivate_policy - deactivate a blkcg policy on a gendisk
+ * @disk: gendisk of interest
  * @pol: blkcg policy to deactivate
  *
- * Deactivate @pol on @q.  Follows the same synchronization rules as
+ * Deactivate @pol on @disk.  Follows the same synchronization rules as
  * blkcg_activate_policy().
  */
-void blkcg_deactivate_policy(struct request_queue *q,
+void blkcg_deactivate_policy(struct gendisk *disk,
 			     const struct blkcg_policy *pol)
 {
+	struct request_queue *q = disk->queue;
 	struct blkcg_gq *blkg;
 
 	if (!blkcg_policy_enabled(q, pol))
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index 85b267234823ab..e9e0c00d13d64d 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -190,9 +190,8 @@ void blkcg_exit_disk(struct gendisk *disk);
 /* Blkio controller policy registration */
 int blkcg_policy_register(struct blkcg_policy *pol);
 void blkcg_policy_unregister(struct blkcg_policy *pol);
-int blkcg_activate_policy(struct request_queue *q,
-			  const struct blkcg_policy *pol);
-void blkcg_deactivate_policy(struct request_queue *q,
+int blkcg_activate_policy(struct gendisk *disk, const struct blkcg_policy *pol);
+void blkcg_deactivate_policy(struct gendisk *disk,
 			     const struct blkcg_policy *pol);
 
 const char *blkg_dev_name(struct blkcg_gq *blkg);
@@ -491,9 +490,9 @@ static inline int blkcg_init_disk(struct gendisk *disk) { return 0; }
 static inline void blkcg_exit_disk(struct gendisk *disk) { }
 static inline int blkcg_policy_register(struct blkcg_policy *pol) { return 0; }
 static inline void blkcg_policy_unregister(struct blkcg_policy *pol) { }
-static inline int blkcg_activate_policy(struct request_queue *q,
+static inline int blkcg_activate_policy(struct gendisk *disk,
 					const struct blkcg_policy *pol) { return 0; }
-static inline void blkcg_deactivate_policy(struct request_queue *q,
+static inline void blkcg_deactivate_policy(struct gendisk *disk,
 					   const struct blkcg_policy *pol) { }
 
 static inline struct blkg_policy_data *blkg_to_pd(struct blkcg_gq *blkg,
diff --git a/block/blk-iocost.c b/block/blk-iocost.c
index 54e42b22b3599f..6557bbd409b57e 100644
--- a/block/blk-iocost.c
+++ b/block/blk-iocost.c
@@ -2814,7 +2814,7 @@ static void ioc_rqos_exit(struct rq_qos *rqos)
 {
 	struct ioc *ioc = rqos_to_ioc(rqos);
 
-	blkcg_deactivate_policy(rqos->disk->queue, &blkcg_policy_iocost);
+	blkcg_deactivate_policy(rqos->disk, &blkcg_policy_iocost);
 
 	spin_lock_irq(&ioc->lock);
 	ioc->running = IOC_STOP;
@@ -2886,7 +2886,7 @@ static int blk_iocost_init(struct gendisk *disk)
 	if (ret)
 		goto err_free_ioc;
 
-	ret = blkcg_activate_policy(disk->queue, &blkcg_policy_iocost);
+	ret = blkcg_activate_policy(disk, &blkcg_policy_iocost);
 	if (ret)
 		goto err_del_qos;
 	return 0;
diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c
index 8e1e43bbde6f0b..39853fc5c2b02f 100644
--- a/block/blk-iolatency.c
+++ b/block/blk-iolatency.c
@@ -646,7 +646,7 @@ static void blkcg_iolatency_exit(struct rq_qos *rqos)
 
 	timer_shutdown_sync(&blkiolat->timer);
 	flush_work(&blkiolat->enable_work);
-	blkcg_deactivate_policy(rqos->disk->queue, &blkcg_policy_iolatency);
+	blkcg_deactivate_policy(rqos->disk, &blkcg_policy_iolatency);
 	kfree(blkiolat);
 }
 
@@ -768,7 +768,7 @@ int blk_iolatency_init(struct gendisk *disk)
 			 &blkcg_iolatency_ops);
 	if (ret)
 		goto err_free;
-	ret = blkcg_activate_policy(disk->queue, &blkcg_policy_iolatency);
+	ret = blkcg_activate_policy(disk, &blkcg_policy_iolatency);
 	if (ret)
 		goto err_qos_del;
 
diff --git a/block/blk-ioprio.c b/block/blk-ioprio.c
index 8bb6b8eba4cee8..8194826cc824bc 100644
--- a/block/blk-ioprio.c
+++ b/block/blk-ioprio.c
@@ -204,12 +204,12 @@ void blkcg_set_ioprio(struct bio *bio)
 
 void blk_ioprio_exit(struct gendisk *disk)
 {
-	blkcg_deactivate_policy(disk->queue, &ioprio_policy);
+	blkcg_deactivate_policy(disk, &ioprio_policy);
 }
 
 int blk_ioprio_init(struct gendisk *disk)
 {
-	return blkcg_activate_policy(disk->queue, &ioprio_policy);
+	return blkcg_activate_policy(disk, &ioprio_policy);
 }
 
 static int __init ioprio_init(void)
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index f802d8f9099430..efc0a9092c6942 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -2395,7 +2395,7 @@ int blk_throtl_init(struct gendisk *disk)
 	td->low_downgrade_time = jiffies;
 
 	/* activate policy */
-	ret = blkcg_activate_policy(q, &blkcg_policy_throtl);
+	ret = blkcg_activate_policy(disk, &blkcg_policy_throtl);
 	if (ret) {
 		free_percpu(td->latency_buckets[READ]);
 		free_percpu(td->latency_buckets[WRITE]);
@@ -2411,7 +2411,7 @@ void blk_throtl_exit(struct gendisk *disk)
 	BUG_ON(!q->td);
 	del_timer_sync(&q->td->service_queue.pending_timer);
 	throtl_shutdown_wq(q);
-	blkcg_deactivate_policy(q, &blkcg_policy_throtl);
+	blkcg_deactivate_policy(disk, &blkcg_policy_throtl);
 	free_percpu(q->td->latency_buckets[READ]);
 	free_percpu(q->td->latency_buckets[WRITE]);
 	kfree(q->td);
-- 
2.39.0

Re: [PATCH 12/15] blk-cgroup: pass a gendisk to blkcg_{de,}activate_policy

[Andreas Herrmann]

On Tue, Jan 17, 2023 at 09:12:54AM +0100, Christoph Hellwig wrote:
> Prepare for storing the blkcg information in the gendisk instead of
> the request_queue.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  block/bfq-cgroup.c    |  2 +-
>  block/bfq-iosched.c   |  2 +-
>  block/blk-cgroup.c    | 19 ++++++++++---------
>  block/blk-cgroup.h    |  9 ++++-----
>  block/blk-iocost.c    |  4 ++--
>  block/blk-iolatency.c |  4 ++--
>  block/blk-ioprio.c    |  4 ++--
>  block/blk-throttle.c  |  4 ++--
>  8 files changed, 24 insertions(+), 24 deletions(-)

(One nitpick below.)
Looks good to me. Feel free to add
Reviewed-by: Andreas Herrmann <aherrmann@suse.de>

> diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c
> index 72a033776722c9..b1b8eca99d988f 100644
> --- a/block/bfq-cgroup.c
> +++ b/block/bfq-cgroup.c
> @@ -1293,7 +1293,7 @@ struct bfq_group *bfq_create_group_hierarchy(struct bfq_data *bfqd, int node)
>  {
>  	int ret;
>  
> -	ret = blkcg_activate_policy(bfqd->queue, &blkcg_policy_bfq);
> +	ret = blkcg_activate_policy(bfqd->queue->disk, &blkcg_policy_bfq);
>  	if (ret)
>  		return NULL;
>  
> diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
> index 68062243f2c142..eda3a838f3c3fd 100644
> --- a/block/bfq-iosched.c
> +++ b/block/bfq-iosched.c
> @@ -7155,7 +7155,7 @@ static void bfq_exit_queue(struct elevator_queue *e)
>  	bfqg_and_blkg_put(bfqd->root_group);
>  
>  #ifdef CONFIG_BFQ_GROUP_IOSCHED
> -	blkcg_deactivate_policy(bfqd->queue, &blkcg_policy_bfq);
> +	blkcg_deactivate_policy(bfqd->queue->disk, &blkcg_policy_bfq);
>  #else
>  	spin_lock_irq(&bfqd->lock);
>  	bfq_put_async_queues(bfqd, bfqd->root_group);
> diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
> index 603e911d1350db..353421afe1d70d 100644
> --- a/block/blk-cgroup.c
> +++ b/block/blk-cgroup.c
> @@ -1363,13 +1363,13 @@ EXPORT_SYMBOL_GPL(io_cgrp_subsys);
>  
>  /**
>   * blkcg_activate_policy - activate a blkcg policy on a request_queue
                                                           ^^^^^^^^^^^^^
							   gendisk
> - * @q: request_queue of interest
> + * @disk: gendisk of interest
>   * @pol: blkcg policy to activate
>   *
> - * Activate @pol on @q.  Requires %GFP_KERNEL context.  @q goes through
> + * Activate @pol on @disk.  Requires %GFP_KERNEL context.  @disk goes through
>   * bypass mode to populate its blkgs with policy_data for @pol.
>   *
> - * Activation happens with @q bypassed, so nobody would be accessing blkgs
> + * Activation happens with @disk bypassed, so nobody would be accessing blkgs
>   * from IO path.  Update of each blkg is protected by both queue and blkcg
>   * locks so that holding either lock and testing blkcg_policy_enabled() is
>   * always enough for dereferencing policy data.
> @@ -1377,9 +1377,9 @@ EXPORT_SYMBOL_GPL(io_cgrp_subsys);
>   * The caller is responsible for synchronizing [de]activations and policy
>   * [un]registerations.  Returns 0 on success, -errno on failure.
>   */
> -int blkcg_activate_policy(struct request_queue *q,
> -			  const struct blkcg_policy *pol)
> +int blkcg_activate_policy(struct gendisk *disk, const struct blkcg_policy *pol)
>  {
> +	struct request_queue *q = disk->queue;
>  	struct blkg_policy_data *pd_prealloc = NULL;
>  	struct blkcg_gq *blkg, *pinned_blkg = NULL;
>  	int ret;
> @@ -1473,16 +1473,17 @@ int blkcg_activate_policy(struct request_queue *q,
>  EXPORT_SYMBOL_GPL(blkcg_activate_policy);
>  
>  /**
> - * blkcg_deactivate_policy - deactivate a blkcg policy on a request_queue
> - * @q: request_queue of interest
> + * blkcg_deactivate_policy - deactivate a blkcg policy on a gendisk
> + * @disk: gendisk of interest
>   * @pol: blkcg policy to deactivate
>   *
> - * Deactivate @pol on @q.  Follows the same synchronization rules as
> + * Deactivate @pol on @disk.  Follows the same synchronization rules as
>   * blkcg_activate_policy().
>   */
> -void blkcg_deactivate_policy(struct request_queue *q,
> +void blkcg_deactivate_policy(struct gendisk *disk,
>  			     const struct blkcg_policy *pol)
>  {
> +	struct request_queue *q = disk->queue;
>  	struct blkcg_gq *blkg;
>  
>  	if (!blkcg_policy_enabled(q, pol))
> diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
> index 85b267234823ab..e9e0c00d13d64d 100644
> --- a/block/blk-cgroup.h
> +++ b/block/blk-cgroup.h
> @@ -190,9 +190,8 @@ void blkcg_exit_disk(struct gendisk *disk);
>  /* Blkio controller policy registration */
>  int blkcg_policy_register(struct blkcg_policy *pol);
>  void blkcg_policy_unregister(struct blkcg_policy *pol);
> -int blkcg_activate_policy(struct request_queue *q,
> -			  const struct blkcg_policy *pol);
> -void blkcg_deactivate_policy(struct request_queue *q,
> +int blkcg_activate_policy(struct gendisk *disk, const struct blkcg_policy *pol);
> +void blkcg_deactivate_policy(struct gendisk *disk,
>  			     const struct blkcg_policy *pol);
>  
>  const char *blkg_dev_name(struct blkcg_gq *blkg);
> @@ -491,9 +490,9 @@ static inline int blkcg_init_disk(struct gendisk *disk) { return 0; }
>  static inline void blkcg_exit_disk(struct gendisk *disk) { }
>  static inline int blkcg_policy_register(struct blkcg_policy *pol) { return 0; }
>  static inline void blkcg_policy_unregister(struct blkcg_policy *pol) { }
> -static inline int blkcg_activate_policy(struct request_queue *q,
> +static inline int blkcg_activate_policy(struct gendisk *disk,
>  					const struct blkcg_policy *pol) { return 0; }
> -static inline void blkcg_deactivate_policy(struct request_queue *q,
> +static inline void blkcg_deactivate_policy(struct gendisk *disk,
>  					   const struct blkcg_policy *pol) { }
>  
>  static inline struct blkg_policy_data *blkg_to_pd(struct blkcg_gq *blkg,
> diff --git a/block/blk-iocost.c b/block/blk-iocost.c
> index 54e42b22b3599f..6557bbd409b57e 100644
> --- a/block/blk-iocost.c
> +++ b/block/blk-iocost.c
> @@ -2814,7 +2814,7 @@ static void ioc_rqos_exit(struct rq_qos *rqos)
>  {
>  	struct ioc *ioc = rqos_to_ioc(rqos);
>  
> -	blkcg_deactivate_policy(rqos->disk->queue, &blkcg_policy_iocost);
> +	blkcg_deactivate_policy(rqos->disk, &blkcg_policy_iocost);
>  
>  	spin_lock_irq(&ioc->lock);
>  	ioc->running = IOC_STOP;
> @@ -2886,7 +2886,7 @@ static int blk_iocost_init(struct gendisk *disk)
>  	if (ret)
>  		goto err_free_ioc;
>  
> -	ret = blkcg_activate_policy(disk->queue, &blkcg_policy_iocost);
> +	ret = blkcg_activate_policy(disk, &blkcg_policy_iocost);
>  	if (ret)
>  		goto err_del_qos;
>  	return 0;
> diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c
> index 8e1e43bbde6f0b..39853fc5c2b02f 100644
> --- a/block/blk-iolatency.c
> +++ b/block/blk-iolatency.c
> @@ -646,7 +646,7 @@ static void blkcg_iolatency_exit(struct rq_qos *rqos)
>  
>  	timer_shutdown_sync(&blkiolat->timer);
>  	flush_work(&blkiolat->enable_work);
> -	blkcg_deactivate_policy(rqos->disk->queue, &blkcg_policy_iolatency);
> +	blkcg_deactivate_policy(rqos->disk, &blkcg_policy_iolatency);
>  	kfree(blkiolat);
>  }
>  
> @@ -768,7 +768,7 @@ int blk_iolatency_init(struct gendisk *disk)
>  			 &blkcg_iolatency_ops);
>  	if (ret)
>  		goto err_free;
> -	ret = blkcg_activate_policy(disk->queue, &blkcg_policy_iolatency);
> +	ret = blkcg_activate_policy(disk, &blkcg_policy_iolatency);
>  	if (ret)
>  		goto err_qos_del;
>  
> diff --git a/block/blk-ioprio.c b/block/blk-ioprio.c
> index 8bb6b8eba4cee8..8194826cc824bc 100644
> --- a/block/blk-ioprio.c
> +++ b/block/blk-ioprio.c
> @@ -204,12 +204,12 @@ void blkcg_set_ioprio(struct bio *bio)
>  
>  void blk_ioprio_exit(struct gendisk *disk)
>  {
> -	blkcg_deactivate_policy(disk->queue, &ioprio_policy);
> +	blkcg_deactivate_policy(disk, &ioprio_policy);
>  }
>  
>  int blk_ioprio_init(struct gendisk *disk)
>  {
> -	return blkcg_activate_policy(disk->queue, &ioprio_policy);
> +	return blkcg_activate_policy(disk, &ioprio_policy);
>  }
>  
>  static int __init ioprio_init(void)
> diff --git a/block/blk-throttle.c b/block/blk-throttle.c
> index f802d8f9099430..efc0a9092c6942 100644
> --- a/block/blk-throttle.c
> +++ b/block/blk-throttle.c
> @@ -2395,7 +2395,7 @@ int blk_throtl_init(struct gendisk *disk)
>  	td->low_downgrade_time = jiffies;
>  
>  	/* activate policy */
> -	ret = blkcg_activate_policy(q, &blkcg_policy_throtl);
> +	ret = blkcg_activate_policy(disk, &blkcg_policy_throtl);
>  	if (ret) {
>  		free_percpu(td->latency_buckets[READ]);
>  		free_percpu(td->latency_buckets[WRITE]);
> @@ -2411,7 +2411,7 @@ void blk_throtl_exit(struct gendisk *disk)
>  	BUG_ON(!q->td);
>  	del_timer_sync(&q->td->service_queue.pending_timer);
>  	throtl_shutdown_wq(q);
> -	blkcg_deactivate_policy(q, &blkcg_policy_throtl);
> +	blkcg_deactivate_policy(disk, &blkcg_policy_throtl);
>  	free_percpu(q->td->latency_buckets[READ]);
>  	free_percpu(q->td->latency_buckets[WRITE]);
>  	kfree(q->td);
> -- 
> 2.39.0
> 

-- 
Regards,
Andreas

SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nürnberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Martje Boudien Moerman
(HRB 36809, AG Nürnberg)

Re: [PATCH 12/15] blk-cgroup: pass a gendisk to blkcg_{de,}activate_policy

[Hannes Reinecke]

On 1/17/23 09:12, Christoph Hellwig wrote:
> Prepare for storing the blkcg information in the gendisk instead of
> the request_queue.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>   block/bfq-cgroup.c    |  2 +-
>   block/bfq-iosched.c   |  2 +-
>   block/blk-cgroup.c    | 19 ++++++++++---------
>   block/blk-cgroup.h    |  9 ++++-----
>   block/blk-iocost.c    |  4 ++--
>   block/blk-iolatency.c |  4 ++--
>   block/blk-ioprio.c    |  4 ++--
>   block/blk-throttle.c  |  4 ++--
>   8 files changed, 24 insertions(+), 24 deletions(-)
> Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare@suse.de                              +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew
Myers, Andrew McDonald, Martje Boudien Moerman

[PATCH 13/15] blk-cgroup: pass a gendisk to pd_alloc_fn

[Christoph Hellwig]

No need to the request_queue here, pass a gendisk and extract the
node ids from that.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/bfq-cgroup.c    |  6 +++---
 block/blk-cgroup.c    | 10 +++++-----
 block/blk-cgroup.h    |  4 ++--
 block/blk-iocost.c    |  7 ++++---
 block/blk-iolatency.c |  7 +++----
 block/blk-ioprio.c    |  2 +-
 block/blk-throttle.c  |  7 +++----
 7 files changed, 21 insertions(+), 22 deletions(-)

diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c
index b1b8eca99d988f..055f9684c1c502 100644
--- a/block/bfq-cgroup.c
+++ b/block/bfq-cgroup.c
@@ -515,12 +515,12 @@ static void bfq_cpd_free(struct blkcg_policy_data *cpd)
 	kfree(cpd_to_bfqgd(cpd));
 }
 
-static struct blkg_policy_data *bfq_pd_alloc(gfp_t gfp, struct request_queue *q,
-					     struct blkcg *blkcg)
+static struct blkg_policy_data *bfq_pd_alloc(struct gendisk *disk,
+		struct blkcg *blkcg, gfp_t gfp)
 {
 	struct bfq_group *bfqg;
 
-	bfqg = kzalloc_node(sizeof(*bfqg), gfp, q->node);
+	bfqg = kzalloc_node(sizeof(*bfqg), gfp, disk->node_id);
 	if (!bfqg)
 		return NULL;
 
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 353421afe1d70d..601b156897dea4 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -268,7 +268,7 @@ static struct blkcg_gq *blkg_alloc(struct blkcg *blkcg, struct gendisk *disk,
 			continue;
 
 		/* alloc per-policy data and attach it to blkg */
-		pd = pol->pd_alloc_fn(gfp_mask, disk->queue, blkcg);
+		pd = pol->pd_alloc_fn(disk, blkcg, gfp_mask);
 		if (!pd)
 			goto err_free;
 
@@ -1404,8 +1404,8 @@ int blkcg_activate_policy(struct gendisk *disk, const struct blkcg_policy *pol)
 			pd = pd_prealloc;
 			pd_prealloc = NULL;
 		} else {
-			pd = pol->pd_alloc_fn(GFP_NOWAIT | __GFP_NOWARN, q,
-					      blkg->blkcg);
+			pd = pol->pd_alloc_fn(disk, blkg->blkcg,
+					      GFP_NOWAIT | __GFP_NOWARN);
 		}
 
 		if (!pd) {
@@ -1422,8 +1422,8 @@ int blkcg_activate_policy(struct gendisk *disk, const struct blkcg_policy *pol)
 
 			if (pd_prealloc)
 				pol->pd_free_fn(pd_prealloc);
-			pd_prealloc = pol->pd_alloc_fn(GFP_KERNEL, q,
-						       blkg->blkcg);
+			pd_prealloc = pol->pd_alloc_fn(disk, blkg->blkcg,
+						       GFP_KERNEL);
 			if (pd_prealloc)
 				goto retry;
 			else
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index e9e0c00d13d64d..9a2cd3c71a94a2 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -150,8 +150,8 @@ typedef struct blkcg_policy_data *(blkcg_pol_alloc_cpd_fn)(gfp_t gfp);
 typedef void (blkcg_pol_init_cpd_fn)(struct blkcg_policy_data *cpd);
 typedef void (blkcg_pol_free_cpd_fn)(struct blkcg_policy_data *cpd);
 typedef void (blkcg_pol_bind_cpd_fn)(struct blkcg_policy_data *cpd);
-typedef struct blkg_policy_data *(blkcg_pol_alloc_pd_fn)(gfp_t gfp,
-				struct request_queue *q, struct blkcg *blkcg);
+typedef struct blkg_policy_data *(blkcg_pol_alloc_pd_fn)(struct gendisk *disk,
+		struct blkcg *blkcg, gfp_t gfp);
 typedef void (blkcg_pol_init_pd_fn)(struct blkg_policy_data *pd);
 typedef void (blkcg_pol_online_pd_fn)(struct blkg_policy_data *pd);
 typedef void (blkcg_pol_offline_pd_fn)(struct blkg_policy_data *pd);
diff --git a/block/blk-iocost.c b/block/blk-iocost.c
index 6557bbd409b57e..3f41d83b4c4ecf 100644
--- a/block/blk-iocost.c
+++ b/block/blk-iocost.c
@@ -2916,13 +2916,14 @@ static void ioc_cpd_free(struct blkcg_policy_data *cpd)
 	kfree(container_of(cpd, struct ioc_cgrp, cpd));
 }
 
-static struct blkg_policy_data *ioc_pd_alloc(gfp_t gfp, struct request_queue *q,
-					     struct blkcg *blkcg)
+static struct blkg_policy_data *ioc_pd_alloc(struct gendisk *disk,
+		struct blkcg *blkcg, gfp_t gfp)
 {
 	int levels = blkcg->css.cgroup->level + 1;
 	struct ioc_gq *iocg;
 
-	iocg = kzalloc_node(struct_size(iocg, ancestors, levels), gfp, q->node);
+	iocg = kzalloc_node(struct_size(iocg, ancestors, levels), gfp,
+			    disk->node_id);
 	if (!iocg)
 		return NULL;
 
diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c
index 39853fc5c2b02f..bc0d217f5c1723 100644
--- a/block/blk-iolatency.c
+++ b/block/blk-iolatency.c
@@ -946,13 +946,12 @@ static void iolatency_pd_stat(struct blkg_policy_data *pd, struct seq_file *s)
 			iolat->max_depth, avg_lat, cur_win);
 }
 
-static struct blkg_policy_data *iolatency_pd_alloc(gfp_t gfp,
-						   struct request_queue *q,
-						   struct blkcg *blkcg)
+static struct blkg_policy_data *iolatency_pd_alloc(struct gendisk *disk,
+		struct blkcg *blkcg, gfp_t gfp)
 {
 	struct iolatency_grp *iolat;
 
-	iolat = kzalloc_node(sizeof(*iolat), gfp, q->node);
+	iolat = kzalloc_node(sizeof(*iolat), gfp, disk->node_id);
 	if (!iolat)
 		return NULL;
 	iolat->stats = __alloc_percpu_gfp(sizeof(struct latency_stat),
diff --git a/block/blk-ioprio.c b/block/blk-ioprio.c
index 8194826cc824bc..055529b9b92bab 100644
--- a/block/blk-ioprio.c
+++ b/block/blk-ioprio.c
@@ -116,7 +116,7 @@ static ssize_t ioprio_set_prio_policy(struct kernfs_open_file *of, char *buf,
 }
 
 static struct blkg_policy_data *
-ioprio_alloc_pd(gfp_t gfp, struct request_queue *q, struct blkcg *blkcg)
+ioprio_alloc_pd(struct gendisk *disk, struct blkcg *blkcg, gfp_t gfp)
 {
 	struct ioprio_blkg *ioprio_blkg;
 
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index efc0a9092c6942..74bb1e753ea09d 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -335,14 +335,13 @@ static void throtl_service_queue_init(struct throtl_service_queue *sq)
 	timer_setup(&sq->pending_timer, throtl_pending_timer_fn, 0);
 }
 
-static struct blkg_policy_data *throtl_pd_alloc(gfp_t gfp,
-						struct request_queue *q,
-						struct blkcg *blkcg)
+static struct blkg_policy_data *throtl_pd_alloc(struct gendisk *disk,
+		struct blkcg *blkcg, gfp_t gfp)
 {
 	struct throtl_grp *tg;
 	int rw;
 
-	tg = kzalloc_node(sizeof(*tg), gfp, q->node);
+	tg = kzalloc_node(sizeof(*tg), gfp, disk->node_id);
 	if (!tg)
 		return NULL;
 
-- 
2.39.0

Re: [PATCH 13/15] blk-cgroup: pass a gendisk to pd_alloc_fn

[Andreas Herrmann]

On Tue, Jan 17, 2023 at 09:12:55AM +0100, Christoph Hellwig wrote:
> No need to the request_queue here, pass a gendisk and extract the
> node ids from that.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  block/bfq-cgroup.c    |  6 +++---
>  block/blk-cgroup.c    | 10 +++++-----
>  block/blk-cgroup.h    |  4 ++--
>  block/blk-iocost.c    |  7 ++++---
>  block/blk-iolatency.c |  7 +++----
>  block/blk-ioprio.c    |  2 +-
>  block/blk-throttle.c  |  7 +++----
>  7 files changed, 21 insertions(+), 22 deletions(-)

Looks good to me. Feel free to add
Reviewed-by: Andreas Herrmann <aherrmann@suse.de>

> diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c
> index b1b8eca99d988f..055f9684c1c502 100644
> --- a/block/bfq-cgroup.c
> +++ b/block/bfq-cgroup.c
> @@ -515,12 +515,12 @@ static void bfq_cpd_free(struct blkcg_policy_data *cpd)
>  	kfree(cpd_to_bfqgd(cpd));
>  }
>  
> -static struct blkg_policy_data *bfq_pd_alloc(gfp_t gfp, struct request_queue *q,
> -					     struct blkcg *blkcg)
> +static struct blkg_policy_data *bfq_pd_alloc(struct gendisk *disk,
> +		struct blkcg *blkcg, gfp_t gfp)
>  {
>  	struct bfq_group *bfqg;
>  
> -	bfqg = kzalloc_node(sizeof(*bfqg), gfp, q->node);
> +	bfqg = kzalloc_node(sizeof(*bfqg), gfp, disk->node_id);
>  	if (!bfqg)
>  		return NULL;
>  
> diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
> index 353421afe1d70d..601b156897dea4 100644
> --- a/block/blk-cgroup.c
> +++ b/block/blk-cgroup.c
> @@ -268,7 +268,7 @@ static struct blkcg_gq *blkg_alloc(struct blkcg *blkcg, struct gendisk *disk,
>  			continue;
>  
>  		/* alloc per-policy data and attach it to blkg */
> -		pd = pol->pd_alloc_fn(gfp_mask, disk->queue, blkcg);
> +		pd = pol->pd_alloc_fn(disk, blkcg, gfp_mask);
>  		if (!pd)
>  			goto err_free;
>  
> @@ -1404,8 +1404,8 @@ int blkcg_activate_policy(struct gendisk *disk, const struct blkcg_policy *pol)
>  			pd = pd_prealloc;
>  			pd_prealloc = NULL;
>  		} else {
> -			pd = pol->pd_alloc_fn(GFP_NOWAIT | __GFP_NOWARN, q,
> -					      blkg->blkcg);
> +			pd = pol->pd_alloc_fn(disk, blkg->blkcg,
> +					      GFP_NOWAIT | __GFP_NOWARN);
>  		}
>  
>  		if (!pd) {
> @@ -1422,8 +1422,8 @@ int blkcg_activate_policy(struct gendisk *disk, const struct blkcg_policy *pol)
>  
>  			if (pd_prealloc)
>  				pol->pd_free_fn(pd_prealloc);
> -			pd_prealloc = pol->pd_alloc_fn(GFP_KERNEL, q,
> -						       blkg->blkcg);
> +			pd_prealloc = pol->pd_alloc_fn(disk, blkg->blkcg,
> +						       GFP_KERNEL);
>  			if (pd_prealloc)
>  				goto retry;
>  			else
> diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
> index e9e0c00d13d64d..9a2cd3c71a94a2 100644
> --- a/block/blk-cgroup.h
> +++ b/block/blk-cgroup.h
> @@ -150,8 +150,8 @@ typedef struct blkcg_policy_data *(blkcg_pol_alloc_cpd_fn)(gfp_t gfp);
>  typedef void (blkcg_pol_init_cpd_fn)(struct blkcg_policy_data *cpd);
>  typedef void (blkcg_pol_free_cpd_fn)(struct blkcg_policy_data *cpd);
>  typedef void (blkcg_pol_bind_cpd_fn)(struct blkcg_policy_data *cpd);
> -typedef struct blkg_policy_data *(blkcg_pol_alloc_pd_fn)(gfp_t gfp,
> -				struct request_queue *q, struct blkcg *blkcg);
> +typedef struct blkg_policy_data *(blkcg_pol_alloc_pd_fn)(struct gendisk *disk,
> +		struct blkcg *blkcg, gfp_t gfp);
>  typedef void (blkcg_pol_init_pd_fn)(struct blkg_policy_data *pd);
>  typedef void (blkcg_pol_online_pd_fn)(struct blkg_policy_data *pd);
>  typedef void (blkcg_pol_offline_pd_fn)(struct blkg_policy_data *pd);
> diff --git a/block/blk-iocost.c b/block/blk-iocost.c
> index 6557bbd409b57e..3f41d83b4c4ecf 100644
> --- a/block/blk-iocost.c
> +++ b/block/blk-iocost.c
> @@ -2916,13 +2916,14 @@ static void ioc_cpd_free(struct blkcg_policy_data *cpd)
>  	kfree(container_of(cpd, struct ioc_cgrp, cpd));
>  }
>  
> -static struct blkg_policy_data *ioc_pd_alloc(gfp_t gfp, struct request_queue *q,
> -					     struct blkcg *blkcg)
> +static struct blkg_policy_data *ioc_pd_alloc(struct gendisk *disk,
> +		struct blkcg *blkcg, gfp_t gfp)
>  {
>  	int levels = blkcg->css.cgroup->level + 1;
>  	struct ioc_gq *iocg;
>  
> -	iocg = kzalloc_node(struct_size(iocg, ancestors, levels), gfp, q->node);
> +	iocg = kzalloc_node(struct_size(iocg, ancestors, levels), gfp,
> +			    disk->node_id);
>  	if (!iocg)
>  		return NULL;
>  
> diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c
> index 39853fc5c2b02f..bc0d217f5c1723 100644
> --- a/block/blk-iolatency.c
> +++ b/block/blk-iolatency.c
> @@ -946,13 +946,12 @@ static void iolatency_pd_stat(struct blkg_policy_data *pd, struct seq_file *s)
>  			iolat->max_depth, avg_lat, cur_win);
>  }
>  
> -static struct blkg_policy_data *iolatency_pd_alloc(gfp_t gfp,
> -						   struct request_queue *q,
> -						   struct blkcg *blkcg)
> +static struct blkg_policy_data *iolatency_pd_alloc(struct gendisk *disk,
> +		struct blkcg *blkcg, gfp_t gfp)
>  {
>  	struct iolatency_grp *iolat;
>  
> -	iolat = kzalloc_node(sizeof(*iolat), gfp, q->node);
> +	iolat = kzalloc_node(sizeof(*iolat), gfp, disk->node_id);
>  	if (!iolat)
>  		return NULL;
>  	iolat->stats = __alloc_percpu_gfp(sizeof(struct latency_stat),
> diff --git a/block/blk-ioprio.c b/block/blk-ioprio.c
> index 8194826cc824bc..055529b9b92bab 100644
> --- a/block/blk-ioprio.c
> +++ b/block/blk-ioprio.c
> @@ -116,7 +116,7 @@ static ssize_t ioprio_set_prio_policy(struct kernfs_open_file *of, char *buf,
>  }
>  
>  static struct blkg_policy_data *
> -ioprio_alloc_pd(gfp_t gfp, struct request_queue *q, struct blkcg *blkcg)
> +ioprio_alloc_pd(struct gendisk *disk, struct blkcg *blkcg, gfp_t gfp)
>  {
>  	struct ioprio_blkg *ioprio_blkg;
>  
> diff --git a/block/blk-throttle.c b/block/blk-throttle.c
> index efc0a9092c6942..74bb1e753ea09d 100644
> --- a/block/blk-throttle.c
> +++ b/block/blk-throttle.c
> @@ -335,14 +335,13 @@ static void throtl_service_queue_init(struct throtl_service_queue *sq)
>  	timer_setup(&sq->pending_timer, throtl_pending_timer_fn, 0);
>  }
>  
> -static struct blkg_policy_data *throtl_pd_alloc(gfp_t gfp,
> -						struct request_queue *q,
> -						struct blkcg *blkcg)
> +static struct blkg_policy_data *throtl_pd_alloc(struct gendisk *disk,
> +		struct blkcg *blkcg, gfp_t gfp)
>  {
>  	struct throtl_grp *tg;
>  	int rw;
>  
> -	tg = kzalloc_node(sizeof(*tg), gfp, q->node);
> +	tg = kzalloc_node(sizeof(*tg), gfp, disk->node_id);
>  	if (!tg)
>  		return NULL;
>  
> -- 
> 2.39.0
> 

-- 
Regards,
Andreas

SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nürnberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Martje Boudien Moerman
(HRB 36809, AG Nürnberg)

Re: [PATCH 13/15] blk-cgroup: pass a gendisk to pd_alloc_fn

[Hannes Reinecke]

On 1/17/23 09:12, Christoph Hellwig wrote:
> No need to the request_queue here, pass a gendisk and extract the
> node ids from that.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>   block/bfq-cgroup.c    |  6 +++---
>   block/blk-cgroup.c    | 10 +++++-----
>   block/blk-cgroup.h    |  4 ++--
>   block/blk-iocost.c    |  7 ++++---
>   block/blk-iolatency.c |  7 +++----
>   block/blk-ioprio.c    |  2 +-
>   block/blk-throttle.c  |  7 +++----
>   7 files changed, 21 insertions(+), 22 deletions(-)
> Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare@suse.de                              +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew
Myers, Andrew McDonald, Martje Boudien Moerman

[PATCH 14/15] blk-cgroup: pass a gendisk to blkg_lookup

[Christoph Hellwig]

Pass a gendisk to blkg_lookup and use that to find the match as part
of phasing out usage of the request_queue in the blk-cgroup code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-cgroup.c | 16 ++++++++--------
 block/blk-cgroup.h | 20 ++++++++++----------
 2 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 601b156897dea4..a041b3ddab6e33 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -320,7 +320,7 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg, struct gendisk *disk,
 
 	/* link parent */
 	if (blkcg_parent(blkcg)) {
-		blkg->parent = blkg_lookup(blkcg_parent(blkcg), disk->queue);
+		blkg->parent = blkg_lookup(blkcg_parent(blkcg), disk);
 		if (WARN_ON_ONCE(!blkg->parent)) {
 			ret = -ENODEV;
 			goto err_put_css;
@@ -389,12 +389,12 @@ static struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg,
 
 	WARN_ON_ONCE(!rcu_read_lock_held());
 
-	blkg = blkg_lookup(blkcg, q);
+	blkg = blkg_lookup(blkcg, disk);
 	if (blkg)
 		return blkg;
 
 	spin_lock_irqsave(&q->queue_lock, flags);
-	blkg = blkg_lookup(blkcg, q);
+	blkg = blkg_lookup(blkcg, disk);
 	if (blkg) {
 		if (blkcg != &blkcg_root &&
 		    blkg != rcu_dereference(blkcg->blkg_hint))
@@ -413,7 +413,7 @@ static struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg,
 		struct blkcg_gq *ret_blkg = q->root_blkg;
 
 		while (parent) {
-			blkg = blkg_lookup(parent, q);
+			blkg = blkg_lookup(parent, disk);
 			if (blkg) {
 				/* remember closest blkg */
 				ret_blkg = blkg;
@@ -692,7 +692,7 @@ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol,
 		goto fail_unlock;
 	}
 
-	blkg = blkg_lookup(blkcg, q);
+	blkg = blkg_lookup(blkcg, disk);
 	if (blkg)
 		goto success;
 
@@ -706,7 +706,7 @@ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol,
 		struct blkcg_gq *new_blkg;
 
 		parent = blkcg_parent(blkcg);
-		while (parent && !blkg_lookup(parent, q)) {
+		while (parent && !blkg_lookup(parent, disk)) {
 			pos = parent;
 			parent = blkcg_parent(parent);
 		}
@@ -736,7 +736,7 @@ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol,
 			goto fail_preloaded;
 		}
 
-		blkg = blkg_lookup(pos, q);
+		blkg = blkg_lookup(pos, disk);
 		if (blkg) {
 			blkg_free(new_blkg);
 		} else {
@@ -1804,7 +1804,7 @@ void blkcg_maybe_throttle_current(void)
 	blkcg = css_to_blkcg(blkcg_css());
 	if (!blkcg)
 		goto out;
-	blkg = blkg_lookup(blkcg, disk->queue);
+	blkg = blkg_lookup(blkcg, disk);
 	if (!blkg)
 		goto out;
 	if (!blkg_tryget(blkg))
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index 9a2cd3c71a94a2..3e7508907f33d8 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -230,30 +230,30 @@ static inline bool bio_issue_as_root_blkg(struct bio *bio)
 }
 
 /**
- * blkg_lookup - lookup blkg for the specified blkcg - q pair
+ * blkg_lookup - lookup blkg for the specified blkcg - disk pair
  * @blkcg: blkcg of interest
- * @q: request_queue of interest
+ * @disk: gendisk of interest
  *
- * Lookup blkg for the @blkcg - @q pair.
+ * Lookup blkg for the @blkcg - @disk pair.
 
  * Must be called in a RCU critical section.
  */
 static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg,
-					   struct request_queue *q)
+					   struct gendisk *disk)
 {
 	struct blkcg_gq *blkg;
 
 	WARN_ON_ONCE(!rcu_read_lock_held());
 
 	if (blkcg == &blkcg_root)
-		return q->root_blkg;
+		return disk->queue->root_blkg;
 
 	blkg = rcu_dereference(blkcg->blkg_hint);
-	if (blkg && blkg->disk->queue == q)
+	if (blkg && blkg->disk == disk)
 		return blkg;
 
-	blkg = radix_tree_lookup(&blkcg->blkg_tree, q->id);
-	if (blkg && blkg->disk->queue != q)
+	blkg = radix_tree_lookup(&blkcg->blkg_tree, disk->queue->id);
+	if (blkg && blkg->disk != disk)
 		blkg = NULL;
 	return blkg;
 }
@@ -353,7 +353,7 @@ static inline void blkg_put(struct blkcg_gq *blkg)
 #define blkg_for_each_descendant_pre(d_blkg, pos_css, p_blkg)		\
 	css_for_each_descendant_pre((pos_css), &(p_blkg)->blkcg->css)	\
 		if (((d_blkg) = blkg_lookup(css_to_blkcg(pos_css),	\
-					    (p_blkg)->disk->queue)))
+					    (p_blkg)->disk)))
 
 /**
  * blkg_for_each_descendant_post - post-order walk of a blkg's descendants
@@ -368,7 +368,7 @@ static inline void blkg_put(struct blkcg_gq *blkg)
 #define blkg_for_each_descendant_post(d_blkg, pos_css, p_blkg)		\
 	css_for_each_descendant_post((pos_css), &(p_blkg)->blkcg->css)	\
 		if (((d_blkg) = blkg_lookup(css_to_blkcg(pos_css),	\
-					    (p_blkg)->disk->queue)))
+					    (p_blkg)->disk)))
 
 bool __blkcg_punt_bio_submit(struct bio *bio);
 
-- 
2.39.0

Re: [PATCH 14/15] blk-cgroup: pass a gendisk to blkg_lookup

[Andreas Herrmann]

On Tue, Jan 17, 2023 at 09:12:56AM +0100, Christoph Hellwig wrote:
> Pass a gendisk to blkg_lookup and use that to find the match as part
> of phasing out usage of the request_queue in the blk-cgroup code.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  block/blk-cgroup.c | 16 ++++++++--------
>  block/blk-cgroup.h | 20 ++++++++++----------
>  2 files changed, 18 insertions(+), 18 deletions(-)

Looks good to me. Feel free to add
Reviewed-by: Andreas Herrmann <aherrmann@suse.de>

> diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
> index 601b156897dea4..a041b3ddab6e33 100644
> --- a/block/blk-cgroup.c
> +++ b/block/blk-cgroup.c
> @@ -320,7 +320,7 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg, struct gendisk *disk,
>  
>  	/* link parent */
>  	if (blkcg_parent(blkcg)) {
> -		blkg->parent = blkg_lookup(blkcg_parent(blkcg), disk->queue);
> +		blkg->parent = blkg_lookup(blkcg_parent(blkcg), disk);
>  		if (WARN_ON_ONCE(!blkg->parent)) {
>  			ret = -ENODEV;
>  			goto err_put_css;
> @@ -389,12 +389,12 @@ static struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg,
>  
>  	WARN_ON_ONCE(!rcu_read_lock_held());
>  
> -	blkg = blkg_lookup(blkcg, q);
> +	blkg = blkg_lookup(blkcg, disk);
>  	if (blkg)
>  		return blkg;
>  
>  	spin_lock_irqsave(&q->queue_lock, flags);
> -	blkg = blkg_lookup(blkcg, q);
> +	blkg = blkg_lookup(blkcg, disk);
>  	if (blkg) {
>  		if (blkcg != &blkcg_root &&
>  		    blkg != rcu_dereference(blkcg->blkg_hint))
> @@ -413,7 +413,7 @@ static struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg,
>  		struct blkcg_gq *ret_blkg = q->root_blkg;
>  
>  		while (parent) {
> -			blkg = blkg_lookup(parent, q);
> +			blkg = blkg_lookup(parent, disk);
>  			if (blkg) {
>  				/* remember closest blkg */
>  				ret_blkg = blkg;
> @@ -692,7 +692,7 @@ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol,
>  		goto fail_unlock;
>  	}
>  
> -	blkg = blkg_lookup(blkcg, q);
> +	blkg = blkg_lookup(blkcg, disk);
>  	if (blkg)
>  		goto success;
>  
> @@ -706,7 +706,7 @@ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol,
>  		struct blkcg_gq *new_blkg;
>  
>  		parent = blkcg_parent(blkcg);
> -		while (parent && !blkg_lookup(parent, q)) {
> +		while (parent && !blkg_lookup(parent, disk)) {
>  			pos = parent;
>  			parent = blkcg_parent(parent);
>  		}
> @@ -736,7 +736,7 @@ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol,
>  			goto fail_preloaded;
>  		}
>  
> -		blkg = blkg_lookup(pos, q);
> +		blkg = blkg_lookup(pos, disk);
>  		if (blkg) {
>  			blkg_free(new_blkg);
>  		} else {
> @@ -1804,7 +1804,7 @@ void blkcg_maybe_throttle_current(void)
>  	blkcg = css_to_blkcg(blkcg_css());
>  	if (!blkcg)
>  		goto out;
> -	blkg = blkg_lookup(blkcg, disk->queue);
> +	blkg = blkg_lookup(blkcg, disk);
>  	if (!blkg)
>  		goto out;
>  	if (!blkg_tryget(blkg))
> diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
> index 9a2cd3c71a94a2..3e7508907f33d8 100644
> --- a/block/blk-cgroup.h
> +++ b/block/blk-cgroup.h
> @@ -230,30 +230,30 @@ static inline bool bio_issue_as_root_blkg(struct bio *bio)
>  }
>  
>  /**
> - * blkg_lookup - lookup blkg for the specified blkcg - q pair
> + * blkg_lookup - lookup blkg for the specified blkcg - disk pair
>   * @blkcg: blkcg of interest
> - * @q: request_queue of interest
> + * @disk: gendisk of interest
>   *
> - * Lookup blkg for the @blkcg - @q pair.
> + * Lookup blkg for the @blkcg - @disk pair.
>  
>   * Must be called in a RCU critical section.
>   */
>  static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg,
> -					   struct request_queue *q)
> +					   struct gendisk *disk)
>  {
>  	struct blkcg_gq *blkg;
>  
>  	WARN_ON_ONCE(!rcu_read_lock_held());
>  
>  	if (blkcg == &blkcg_root)
> -		return q->root_blkg;
> +		return disk->queue->root_blkg;
>  
>  	blkg = rcu_dereference(blkcg->blkg_hint);
> -	if (blkg && blkg->disk->queue == q)
> +	if (blkg && blkg->disk == disk)
>  		return blkg;
>  
> -	blkg = radix_tree_lookup(&blkcg->blkg_tree, q->id);
> -	if (blkg && blkg->disk->queue != q)
> +	blkg = radix_tree_lookup(&blkcg->blkg_tree, disk->queue->id);
> +	if (blkg && blkg->disk != disk)
>  		blkg = NULL;
>  	return blkg;
>  }
> @@ -353,7 +353,7 @@ static inline void blkg_put(struct blkcg_gq *blkg)
>  #define blkg_for_each_descendant_pre(d_blkg, pos_css, p_blkg)		\
>  	css_for_each_descendant_pre((pos_css), &(p_blkg)->blkcg->css)	\
>  		if (((d_blkg) = blkg_lookup(css_to_blkcg(pos_css),	\
> -					    (p_blkg)->disk->queue)))
> +					    (p_blkg)->disk)))
>  
>  /**
>   * blkg_for_each_descendant_post - post-order walk of a blkg's descendants
> @@ -368,7 +368,7 @@ static inline void blkg_put(struct blkcg_gq *blkg)
>  #define blkg_for_each_descendant_post(d_blkg, pos_css, p_blkg)		\
>  	css_for_each_descendant_post((pos_css), &(p_blkg)->blkcg->css)	\
>  		if (((d_blkg) = blkg_lookup(css_to_blkcg(pos_css),	\
> -					    (p_blkg)->disk->queue)))
> +					    (p_blkg)->disk)))
>  
>  bool __blkcg_punt_bio_submit(struct bio *bio);
>  
> -- 
> 2.39.0
> 

-- 
Regards,
Andreas

SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nürnberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Martje Boudien Moerman
(HRB 36809, AG Nürnberg)

Re: [PATCH 14/15] blk-cgroup: pass a gendisk to blkg_lookup

[Hannes Reinecke]

On 1/17/23 09:12, Christoph Hellwig wrote:
> Pass a gendisk to blkg_lookup and use that to find the match as part
> of phasing out usage of the request_queue in the blk-cgroup code.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>   block/blk-cgroup.c | 16 ++++++++--------
>   block/blk-cgroup.h | 20 ++++++++++----------
>   2 files changed, 18 insertions(+), 18 deletions(-)
> 
Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare@suse.de                              +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew
Myers, Andrew McDonald, Martje Boudien Moerman

[PATCH 15/15] blk-cgroup: move the cgroup information to struct gendisk

[Christoph Hellwig]

cgroup information only makes sense on a live gendisk that allows
file system I/O (which includes the raw block device).  So move over
the cgroup related members.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/bfq-cgroup.c     |  4 ++--
 block/blk-cgroup.c     | 48 +++++++++++++++++++++---------------------
 block/blk-cgroup.h     |  2 +-
 block/blk-iolatency.c  |  2 +-
 block/blk-throttle.c   | 16 ++++++++------
 include/linux/blkdev.h | 10 ++++-----
 6 files changed, 43 insertions(+), 39 deletions(-)

diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c
index 055f9684c1c502..c13ba851c5221a 100644
--- a/block/bfq-cgroup.c
+++ b/block/bfq-cgroup.c
@@ -1003,7 +1003,7 @@ void bfq_end_wr_async(struct bfq_data *bfqd)
 {
 	struct blkcg_gq *blkg;
 
-	list_for_each_entry(blkg, &bfqd->queue->blkg_list, q_node) {
+	list_for_each_entry(blkg, &bfqd->queue->disk->blkg_list, q_node) {
 		struct bfq_group *bfqg = blkg_to_bfqg(blkg);
 
 		bfq_end_wr_async_queues(bfqd, bfqg);
@@ -1297,7 +1297,7 @@ struct bfq_group *bfq_create_group_hierarchy(struct bfq_data *bfqd, int node)
 	if (ret)
 		return NULL;
 
-	return blkg_to_bfqg(bfqd->queue->root_blkg);
+	return blkg_to_bfqg(bfqd->queue->disk->root_blkg);
 }
 
 struct blkcg_policy blkcg_policy_bfq = {
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index a041b3ddab6e33..0c813b50275cf1 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -108,10 +108,10 @@ static struct cgroup_subsys_state *blkcg_css(void)
 	return task_css(current, io_cgrp_id);
 }
 
-static bool blkcg_policy_enabled(struct request_queue *q,
+static bool blkcg_policy_enabled(struct gendisk *disk,
 				 const struct blkcg_policy *pol)
 {
-	return pol && test_bit(pol->plid, q->blkcg_pols);
+	return pol && test_bit(pol->plid, disk->blkcg_pols);
 }
 
 /**
@@ -264,7 +264,7 @@ static struct blkcg_gq *blkg_alloc(struct blkcg *blkcg, struct gendisk *disk,
 		struct blkcg_policy *pol = blkcg_policy[i];
 		struct blkg_policy_data *pd;
 
-		if (!blkcg_policy_enabled(disk->queue, pol))
+		if (!blkcg_policy_enabled(disk, pol))
 			continue;
 
 		/* alloc per-policy data and attach it to blkg */
@@ -341,7 +341,7 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg, struct gendisk *disk,
 	ret = radix_tree_insert(&blkcg->blkg_tree, disk->queue->id, blkg);
 	if (likely(!ret)) {
 		hlist_add_head_rcu(&blkg->blkcg_node, &blkcg->blkg_list);
-		list_add(&blkg->q_node, &disk->queue->blkg_list);
+		list_add(&blkg->q_node, &disk->blkg_list);
 
 		for (i = 0; i < BLKCG_MAX_POLS; i++) {
 			struct blkcg_policy *pol = blkcg_policy[i];
@@ -410,7 +410,7 @@ static struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg,
 	while (true) {
 		struct blkcg *pos = blkcg;
 		struct blkcg *parent = blkcg_parent(blkcg);
-		struct blkcg_gq *ret_blkg = q->root_blkg;
+		struct blkcg_gq *ret_blkg = disk->root_blkg;
 
 		while (parent) {
 			blkg = blkg_lookup(parent, disk);
@@ -485,7 +485,7 @@ static void blkg_destroy_all(struct gendisk *disk)
 
 restart:
 	spin_lock_irq(&q->queue_lock);
-	list_for_each_entry_safe(blkg, n, &q->blkg_list, q_node) {
+	list_for_each_entry_safe(blkg, n, &disk->blkg_list, q_node) {
 		struct blkcg *blkcg = blkg->blkcg;
 
 		spin_lock(&blkcg->lock);
@@ -504,7 +504,7 @@ static void blkg_destroy_all(struct gendisk *disk)
 		}
 	}
 
-	q->root_blkg = NULL;
+	disk->root_blkg = NULL;
 	spin_unlock_irq(&q->queue_lock);
 }
 
@@ -579,7 +579,7 @@ void blkcg_print_blkgs(struct seq_file *sf, struct blkcg *blkcg,
 	rcu_read_lock();
 	hlist_for_each_entry_rcu(blkg, &blkcg->blkg_list, blkcg_node) {
 		spin_lock_irq(&blkg->disk->queue->queue_lock);
-		if (blkcg_policy_enabled(blkg->disk->queue, pol))
+		if (blkcg_policy_enabled(blkg->disk, pol))
 			total += prfill(sf, blkg->pd[pol->plid], data);
 		spin_unlock_irq(&blkg->disk->queue->queue_lock);
 	}
@@ -687,7 +687,7 @@ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol,
 	rcu_read_lock();
 	spin_lock_irq(&q->queue_lock);
 
-	if (!blkcg_policy_enabled(q, pol)) {
+	if (!blkcg_policy_enabled(disk, pol)) {
 		ret = -EOPNOTSUPP;
 		goto fail_unlock;
 	}
@@ -730,7 +730,7 @@ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol,
 		rcu_read_lock();
 		spin_lock_irq(&q->queue_lock);
 
-		if (!blkcg_policy_enabled(q, pol)) {
+		if (!blkcg_policy_enabled(disk, pol)) {
 			blkg_free(new_blkg);
 			ret = -EOPNOTSUPP;
 			goto fail_preloaded;
@@ -910,7 +910,7 @@ static void blkcg_fill_root_iostats(void)
 	class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
 	while ((dev = class_dev_iter_next(&iter))) {
 		struct block_device *bdev = dev_to_bdev(dev);
-		struct blkcg_gq *blkg = bdev->bd_disk->queue->root_blkg;
+		struct blkcg_gq *blkg = bdev->bd_disk->root_blkg;
 		struct blkg_iostat tmp;
 		int cpu;
 		unsigned long flags;
@@ -1257,7 +1257,7 @@ int blkcg_init_disk(struct gendisk *disk)
 	bool preloaded;
 	int ret;
 
-	INIT_LIST_HEAD(&q->blkg_list);
+	INIT_LIST_HEAD(&disk->blkg_list);
 
 	new_blkg = blkg_alloc(&blkcg_root, disk, GFP_KERNEL);
 	if (!new_blkg)
@@ -1271,7 +1271,7 @@ int blkcg_init_disk(struct gendisk *disk)
 	blkg = blkg_create(&blkcg_root, disk, new_blkg);
 	if (IS_ERR(blkg))
 		goto err_unlock;
-	q->root_blkg = blkg;
+	disk->root_blkg = blkg;
 	spin_unlock_irq(&q->queue_lock);
 
 	if (preloaded)
@@ -1384,7 +1384,7 @@ int blkcg_activate_policy(struct gendisk *disk, const struct blkcg_policy *pol)
 	struct blkcg_gq *blkg, *pinned_blkg = NULL;
 	int ret;
 
-	if (blkcg_policy_enabled(q, pol))
+	if (blkcg_policy_enabled(disk, pol))
 		return 0;
 
 	if (queue_is_mq(q))
@@ -1393,7 +1393,7 @@ int blkcg_activate_policy(struct gendisk *disk, const struct blkcg_policy *pol)
 	spin_lock_irq(&q->queue_lock);
 
 	/* blkg_list is pushed at the head, reverse walk to allocate parents first */
-	list_for_each_entry_reverse(blkg, &q->blkg_list, q_node) {
+	list_for_each_entry_reverse(blkg, &disk->blkg_list, q_node) {
 		struct blkg_policy_data *pd;
 
 		if (blkg->pd[pol->plid])
@@ -1437,10 +1437,10 @@ int blkcg_activate_policy(struct gendisk *disk, const struct blkcg_policy *pol)
 
 	/* all allocated, init in the same order */
 	if (pol->pd_init_fn)
-		list_for_each_entry_reverse(blkg, &q->blkg_list, q_node)
+		list_for_each_entry_reverse(blkg, &disk->blkg_list, q_node)
 			pol->pd_init_fn(blkg->pd[pol->plid]);
 
-	__set_bit(pol->plid, q->blkcg_pols);
+	__set_bit(pol->plid, disk->blkcg_pols);
 	ret = 0;
 
 	spin_unlock_irq(&q->queue_lock);
@@ -1456,7 +1456,7 @@ int blkcg_activate_policy(struct gendisk *disk, const struct blkcg_policy *pol)
 enomem:
 	/* alloc failed, nothing's initialized yet, free everything */
 	spin_lock_irq(&q->queue_lock);
-	list_for_each_entry(blkg, &q->blkg_list, q_node) {
+	list_for_each_entry(blkg, &disk->blkg_list, q_node) {
 		struct blkcg *blkcg = blkg->blkcg;
 
 		spin_lock(&blkcg->lock);
@@ -1486,7 +1486,7 @@ void blkcg_deactivate_policy(struct gendisk *disk,
 	struct request_queue *q = disk->queue;
 	struct blkcg_gq *blkg;
 
-	if (!blkcg_policy_enabled(q, pol))
+	if (!blkcg_policy_enabled(disk, pol))
 		return;
 
 	if (queue_is_mq(q))
@@ -1494,9 +1494,9 @@ void blkcg_deactivate_policy(struct gendisk *disk,
 
 	spin_lock_irq(&q->queue_lock);
 
-	__clear_bit(pol->plid, q->blkcg_pols);
+	__clear_bit(pol->plid, disk->blkcg_pols);
 
-	list_for_each_entry(blkg, &q->blkg_list, q_node) {
+	list_for_each_entry(blkg, &disk->blkg_list, q_node) {
 		struct blkcg *blkcg = blkg->blkcg;
 
 		spin_lock(&blkcg->lock);
@@ -1909,7 +1909,7 @@ static inline struct blkcg_gq *blkg_tryget_closest(struct bio *bio,
  * Associate @bio with the blkg found by combining the css's blkg and the
  * request_queue of the @bio.  An association failure is handled by walking up
  * the blkg tree.  Therefore, the blkg associated can be anything between @blkg
- * and q->root_blkg.  This situation only happens when a cgroup is dying and
+ * and disk->root_blkg.  This situation only happens when a cgroup is dying and
  * then the remaining bios will spill to the closest alive blkg.
  *
  * A reference will be taken on the blkg and will be released when @bio is
@@ -1924,8 +1924,8 @@ void bio_associate_blkg_from_css(struct bio *bio,
 	if (css && css->parent) {
 		bio->bi_blkg = blkg_tryget_closest(bio, css);
 	} else {
-		blkg_get(bdev_get_queue(bio->bi_bdev)->root_blkg);
-		bio->bi_blkg = bdev_get_queue(bio->bi_bdev)->root_blkg;
+		blkg_get(bio->bi_bdev->bd_disk->root_blkg);
+		bio->bi_blkg = bio->bi_bdev->bd_disk->root_blkg;
 	}
 }
 EXPORT_SYMBOL_GPL(bio_associate_blkg_from_css);
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index 3e7508907f33d8..81eca9be7f9105 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -246,7 +246,7 @@ static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg,
 	WARN_ON_ONCE(!rcu_read_lock_held());
 
 	if (blkcg == &blkcg_root)
-		return disk->queue->root_blkg;
+		return disk->root_blkg;
 
 	blkg = rcu_dereference(blkcg->blkg_hint);
 	if (blkg && blkg->disk == disk)
diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c
index bc0d217f5c1723..5d5aa1e526b742 100644
--- a/block/blk-iolatency.c
+++ b/block/blk-iolatency.c
@@ -665,7 +665,7 @@ static void blkiolatency_timer_fn(struct timer_list *t)
 
 	rcu_read_lock();
 	blkg_for_each_descendant_pre(blkg, pos_css,
-				     blkiolat->rqos.disk->queue->root_blkg) {
+				     blkiolat->rqos.disk->root_blkg) {
 		struct iolatency_grp *iolat;
 		struct child_latency_info *lat_info;
 		unsigned long flags;
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 74bb1e753ea09d..902203bdddb4b4 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -451,7 +451,8 @@ static void blk_throtl_update_limit_valid(struct throtl_data *td)
 	bool low_valid = false;
 
 	rcu_read_lock();
-	blkg_for_each_descendant_post(blkg, pos_css, td->queue->root_blkg) {
+	blkg_for_each_descendant_post(blkg, pos_css,
+			td->queue->disk->root_blkg) {
 		struct throtl_grp *tg = blkg_to_tg(blkg);
 
 		if (tg->bps[READ][LIMIT_LOW] || tg->bps[WRITE][LIMIT_LOW] ||
@@ -1180,7 +1181,7 @@ static void throtl_pending_timer_fn(struct timer_list *t)
 
 	spin_lock_irq(&q->queue_lock);
 
-	if (!q->root_blkg)
+	if (!q->disk->root_blkg)
 		goto out_unlock;
 
 	if (throtl_can_upgrade(td, NULL))
@@ -1322,7 +1323,8 @@ static void tg_conf_updated(struct throtl_grp *tg, bool global)
 	 * blk-throttle.
 	 */
 	blkg_for_each_descendant_pre(blkg, pos_css,
-			global ? tg->td->queue->root_blkg : tg_to_blkg(tg)) {
+			global ? tg->td->queue->disk->root_blkg :
+			tg_to_blkg(tg)) {
 		struct throtl_grp *this_tg = blkg_to_tg(blkg);
 		struct throtl_grp *parent_tg;
 
@@ -1717,7 +1719,7 @@ void blk_throtl_cancel_bios(struct gendisk *disk)
 	 * path need RCU protection and to prevent warning from lockdep.
 	 */
 	rcu_read_lock();
-	blkg_for_each_descendant_post(blkg, pos_css, q->root_blkg) {
+	blkg_for_each_descendant_post(blkg, pos_css, disk->root_blkg) {
 		struct throtl_grp *tg = blkg_to_tg(blkg);
 		struct throtl_service_queue *sq = &tg->service_queue;
 
@@ -1871,7 +1873,8 @@ static bool throtl_can_upgrade(struct throtl_data *td,
 		return false;
 
 	rcu_read_lock();
-	blkg_for_each_descendant_post(blkg, pos_css, td->queue->root_blkg) {
+	blkg_for_each_descendant_post(blkg, pos_css,
+			td->queue->disk->root_blkg) {
 		struct throtl_grp *tg = blkg_to_tg(blkg);
 
 		if (tg == this_tg)
@@ -1917,7 +1920,8 @@ static void throtl_upgrade_state(struct throtl_data *td)
 	td->low_upgrade_time = jiffies;
 	td->scale = 0;
 	rcu_read_lock();
-	blkg_for_each_descendant_post(blkg, pos_css, td->queue->root_blkg) {
+	blkg_for_each_descendant_post(blkg, pos_css,
+			td->queue->disk->root_blkg) {
 		struct throtl_grp *tg = blkg_to_tg(blkg);
 		struct throtl_service_queue *sq = &tg->service_queue;
 
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index b87ed829ab9418..d27010c25f75f0 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -163,6 +163,11 @@ struct gendisk {
 	struct timer_rand_state *random;
 	atomic_t sync_io;		/* RAID */
 	struct disk_events *ev;
+#ifdef CONFIG_BLK_CGROUP
+	DECLARE_BITMAP		(blkcg_pols, BLKCG_MAX_POLS);
+	struct blkcg_gq		*root_blkg;
+	struct list_head	blkg_list;
+#endif
 #ifdef  CONFIG_BLK_DEV_INTEGRITY
 	struct kobject integrity_kobj;
 #endif	/* CONFIG_BLK_DEV_INTEGRITY */
@@ -481,11 +486,6 @@ struct request_queue {
 	struct blk_mq_tags	*sched_shared_tags;
 
 	struct list_head	icq_list;
-#ifdef CONFIG_BLK_CGROUP
-	DECLARE_BITMAP		(blkcg_pols, BLKCG_MAX_POLS);
-	struct blkcg_gq		*root_blkg;
-	struct list_head	blkg_list;
-#endif
 
 	struct queue_limits	limits;
 
-- 
2.39.0

Re: [PATCH 15/15] blk-cgroup: move the cgroup information to struct gendisk

[Andreas Herrmann]

On Tue, Jan 17, 2023 at 09:12:57AM +0100, Christoph Hellwig wrote:
> cgroup information only makes sense on a live gendisk that allows
> file system I/O (which includes the raw block device).  So move over
> the cgroup related members.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  block/bfq-cgroup.c     |  4 ++--
>  block/blk-cgroup.c     | 48 +++++++++++++++++++++---------------------
>  block/blk-cgroup.h     |  2 +-
>  block/blk-iolatency.c  |  2 +-
>  block/blk-throttle.c   | 16 ++++++++------
>  include/linux/blkdev.h | 10 ++++-----
>  6 files changed, 43 insertions(+), 39 deletions(-)

Looks good to me. Feel free to add
Reviewed-by: Andreas Herrmann <aherrmann@suse.de>

> diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c
> index 055f9684c1c502..c13ba851c5221a 100644
> --- a/block/bfq-cgroup.c
> +++ b/block/bfq-cgroup.c
> @@ -1003,7 +1003,7 @@ void bfq_end_wr_async(struct bfq_data *bfqd)
>  {
>  	struct blkcg_gq *blkg;
>  
> -	list_for_each_entry(blkg, &bfqd->queue->blkg_list, q_node) {
> +	list_for_each_entry(blkg, &bfqd->queue->disk->blkg_list, q_node) {
>  		struct bfq_group *bfqg = blkg_to_bfqg(blkg);
>  
>  		bfq_end_wr_async_queues(bfqd, bfqg);
> @@ -1297,7 +1297,7 @@ struct bfq_group *bfq_create_group_hierarchy(struct bfq_data *bfqd, int node)
>  	if (ret)
>  		return NULL;
>  
> -	return blkg_to_bfqg(bfqd->queue->root_blkg);
> +	return blkg_to_bfqg(bfqd->queue->disk->root_blkg);
>  }
>  
>  struct blkcg_policy blkcg_policy_bfq = {
> diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
> index a041b3ddab6e33..0c813b50275cf1 100644
> --- a/block/blk-cgroup.c
> +++ b/block/blk-cgroup.c
> @@ -108,10 +108,10 @@ static struct cgroup_subsys_state *blkcg_css(void)
>  	return task_css(current, io_cgrp_id);
>  }
>  
> -static bool blkcg_policy_enabled(struct request_queue *q,
> +static bool blkcg_policy_enabled(struct gendisk *disk,
>  				 const struct blkcg_policy *pol)
>  {
> -	return pol && test_bit(pol->plid, q->blkcg_pols);
> +	return pol && test_bit(pol->plid, disk->blkcg_pols);
>  }
>  
>  /**
> @@ -264,7 +264,7 @@ static struct blkcg_gq *blkg_alloc(struct blkcg *blkcg, struct gendisk *disk,
>  		struct blkcg_policy *pol = blkcg_policy[i];
>  		struct blkg_policy_data *pd;
>  
> -		if (!blkcg_policy_enabled(disk->queue, pol))
> +		if (!blkcg_policy_enabled(disk, pol))
>  			continue;
>  
>  		/* alloc per-policy data and attach it to blkg */
> @@ -341,7 +341,7 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg, struct gendisk *disk,
>  	ret = radix_tree_insert(&blkcg->blkg_tree, disk->queue->id, blkg);
>  	if (likely(!ret)) {
>  		hlist_add_head_rcu(&blkg->blkcg_node, &blkcg->blkg_list);
> -		list_add(&blkg->q_node, &disk->queue->blkg_list);
> +		list_add(&blkg->q_node, &disk->blkg_list);
>  
>  		for (i = 0; i < BLKCG_MAX_POLS; i++) {
>  			struct blkcg_policy *pol = blkcg_policy[i];
> @@ -410,7 +410,7 @@ static struct blkcg_gq *blkg_lookup_create(struct blkcg *blkcg,
>  	while (true) {
>  		struct blkcg *pos = blkcg;
>  		struct blkcg *parent = blkcg_parent(blkcg);
> -		struct blkcg_gq *ret_blkg = q->root_blkg;
> +		struct blkcg_gq *ret_blkg = disk->root_blkg;
>  
>  		while (parent) {
>  			blkg = blkg_lookup(parent, disk);
> @@ -485,7 +485,7 @@ static void blkg_destroy_all(struct gendisk *disk)
>  
>  restart:
>  	spin_lock_irq(&q->queue_lock);
> -	list_for_each_entry_safe(blkg, n, &q->blkg_list, q_node) {
> +	list_for_each_entry_safe(blkg, n, &disk->blkg_list, q_node) {
>  		struct blkcg *blkcg = blkg->blkcg;
>  
>  		spin_lock(&blkcg->lock);
> @@ -504,7 +504,7 @@ static void blkg_destroy_all(struct gendisk *disk)
>  		}
>  	}
>  
> -	q->root_blkg = NULL;
> +	disk->root_blkg = NULL;
>  	spin_unlock_irq(&q->queue_lock);
>  }
>  
> @@ -579,7 +579,7 @@ void blkcg_print_blkgs(struct seq_file *sf, struct blkcg *blkcg,
>  	rcu_read_lock();
>  	hlist_for_each_entry_rcu(blkg, &blkcg->blkg_list, blkcg_node) {
>  		spin_lock_irq(&blkg->disk->queue->queue_lock);
> -		if (blkcg_policy_enabled(blkg->disk->queue, pol))
> +		if (blkcg_policy_enabled(blkg->disk, pol))
>  			total += prfill(sf, blkg->pd[pol->plid], data);
>  		spin_unlock_irq(&blkg->disk->queue->queue_lock);
>  	}
> @@ -687,7 +687,7 @@ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol,
>  	rcu_read_lock();
>  	spin_lock_irq(&q->queue_lock);
>  
> -	if (!blkcg_policy_enabled(q, pol)) {
> +	if (!blkcg_policy_enabled(disk, pol)) {
>  		ret = -EOPNOTSUPP;
>  		goto fail_unlock;
>  	}
> @@ -730,7 +730,7 @@ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol,
>  		rcu_read_lock();
>  		spin_lock_irq(&q->queue_lock);
>  
> -		if (!blkcg_policy_enabled(q, pol)) {
> +		if (!blkcg_policy_enabled(disk, pol)) {
>  			blkg_free(new_blkg);
>  			ret = -EOPNOTSUPP;
>  			goto fail_preloaded;
> @@ -910,7 +910,7 @@ static void blkcg_fill_root_iostats(void)
>  	class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
>  	while ((dev = class_dev_iter_next(&iter))) {
>  		struct block_device *bdev = dev_to_bdev(dev);
> -		struct blkcg_gq *blkg = bdev->bd_disk->queue->root_blkg;
> +		struct blkcg_gq *blkg = bdev->bd_disk->root_blkg;
>  		struct blkg_iostat tmp;
>  		int cpu;
>  		unsigned long flags;
> @@ -1257,7 +1257,7 @@ int blkcg_init_disk(struct gendisk *disk)
>  	bool preloaded;
>  	int ret;
>  
> -	INIT_LIST_HEAD(&q->blkg_list);
> +	INIT_LIST_HEAD(&disk->blkg_list);
>  
>  	new_blkg = blkg_alloc(&blkcg_root, disk, GFP_KERNEL);
>  	if (!new_blkg)
> @@ -1271,7 +1271,7 @@ int blkcg_init_disk(struct gendisk *disk)
>  	blkg = blkg_create(&blkcg_root, disk, new_blkg);
>  	if (IS_ERR(blkg))
>  		goto err_unlock;
> -	q->root_blkg = blkg;
> +	disk->root_blkg = blkg;
>  	spin_unlock_irq(&q->queue_lock);
>  
>  	if (preloaded)
> @@ -1384,7 +1384,7 @@ int blkcg_activate_policy(struct gendisk *disk, const struct blkcg_policy *pol)
>  	struct blkcg_gq *blkg, *pinned_blkg = NULL;
>  	int ret;
>  
> -	if (blkcg_policy_enabled(q, pol))
> +	if (blkcg_policy_enabled(disk, pol))
>  		return 0;
>  
>  	if (queue_is_mq(q))
> @@ -1393,7 +1393,7 @@ int blkcg_activate_policy(struct gendisk *disk, const struct blkcg_policy *pol)
>  	spin_lock_irq(&q->queue_lock);
>  
>  	/* blkg_list is pushed at the head, reverse walk to allocate parents first */
> -	list_for_each_entry_reverse(blkg, &q->blkg_list, q_node) {
> +	list_for_each_entry_reverse(blkg, &disk->blkg_list, q_node) {
>  		struct blkg_policy_data *pd;
>  
>  		if (blkg->pd[pol->plid])
> @@ -1437,10 +1437,10 @@ int blkcg_activate_policy(struct gendisk *disk, const struct blkcg_policy *pol)
>  
>  	/* all allocated, init in the same order */
>  	if (pol->pd_init_fn)
> -		list_for_each_entry_reverse(blkg, &q->blkg_list, q_node)
> +		list_for_each_entry_reverse(blkg, &disk->blkg_list, q_node)
>  			pol->pd_init_fn(blkg->pd[pol->plid]);
>  
> -	__set_bit(pol->plid, q->blkcg_pols);
> +	__set_bit(pol->plid, disk->blkcg_pols);
>  	ret = 0;
>  
>  	spin_unlock_irq(&q->queue_lock);
> @@ -1456,7 +1456,7 @@ int blkcg_activate_policy(struct gendisk *disk, const struct blkcg_policy *pol)
>  enomem:
>  	/* alloc failed, nothing's initialized yet, free everything */
>  	spin_lock_irq(&q->queue_lock);
> -	list_for_each_entry(blkg, &q->blkg_list, q_node) {
> +	list_for_each_entry(blkg, &disk->blkg_list, q_node) {
>  		struct blkcg *blkcg = blkg->blkcg;
>  
>  		spin_lock(&blkcg->lock);
> @@ -1486,7 +1486,7 @@ void blkcg_deactivate_policy(struct gendisk *disk,
>  	struct request_queue *q = disk->queue;
>  	struct blkcg_gq *blkg;
>  
> -	if (!blkcg_policy_enabled(q, pol))
> +	if (!blkcg_policy_enabled(disk, pol))
>  		return;
>  
>  	if (queue_is_mq(q))
> @@ -1494,9 +1494,9 @@ void blkcg_deactivate_policy(struct gendisk *disk,
>  
>  	spin_lock_irq(&q->queue_lock);
>  
> -	__clear_bit(pol->plid, q->blkcg_pols);
> +	__clear_bit(pol->plid, disk->blkcg_pols);
>  
> -	list_for_each_entry(blkg, &q->blkg_list, q_node) {
> +	list_for_each_entry(blkg, &disk->blkg_list, q_node) {
>  		struct blkcg *blkcg = blkg->blkcg;
>  
>  		spin_lock(&blkcg->lock);
> @@ -1909,7 +1909,7 @@ static inline struct blkcg_gq *blkg_tryget_closest(struct bio *bio,
>   * Associate @bio with the blkg found by combining the css's blkg and the
>   * request_queue of the @bio.  An association failure is handled by walking up
>   * the blkg tree.  Therefore, the blkg associated can be anything between @blkg
> - * and q->root_blkg.  This situation only happens when a cgroup is dying and
> + * and disk->root_blkg.  This situation only happens when a cgroup is dying and
>   * then the remaining bios will spill to the closest alive blkg.
>   *
>   * A reference will be taken on the blkg and will be released when @bio is
> @@ -1924,8 +1924,8 @@ void bio_associate_blkg_from_css(struct bio *bio,
>  	if (css && css->parent) {
>  		bio->bi_blkg = blkg_tryget_closest(bio, css);
>  	} else {
> -		blkg_get(bdev_get_queue(bio->bi_bdev)->root_blkg);
> -		bio->bi_blkg = bdev_get_queue(bio->bi_bdev)->root_blkg;
> +		blkg_get(bio->bi_bdev->bd_disk->root_blkg);
> +		bio->bi_blkg = bio->bi_bdev->bd_disk->root_blkg;
>  	}
>  }
>  EXPORT_SYMBOL_GPL(bio_associate_blkg_from_css);
> diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
> index 3e7508907f33d8..81eca9be7f9105 100644
> --- a/block/blk-cgroup.h
> +++ b/block/blk-cgroup.h
> @@ -246,7 +246,7 @@ static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg,
>  	WARN_ON_ONCE(!rcu_read_lock_held());
>  
>  	if (blkcg == &blkcg_root)
> -		return disk->queue->root_blkg;
> +		return disk->root_blkg;
>  
>  	blkg = rcu_dereference(blkcg->blkg_hint);
>  	if (blkg && blkg->disk == disk)
> diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c
> index bc0d217f5c1723..5d5aa1e526b742 100644
> --- a/block/blk-iolatency.c
> +++ b/block/blk-iolatency.c
> @@ -665,7 +665,7 @@ static void blkiolatency_timer_fn(struct timer_list *t)
>  
>  	rcu_read_lock();
>  	blkg_for_each_descendant_pre(blkg, pos_css,
> -				     blkiolat->rqos.disk->queue->root_blkg) {
> +				     blkiolat->rqos.disk->root_blkg) {
>  		struct iolatency_grp *iolat;
>  		struct child_latency_info *lat_info;
>  		unsigned long flags;
> diff --git a/block/blk-throttle.c b/block/blk-throttle.c
> index 74bb1e753ea09d..902203bdddb4b4 100644
> --- a/block/blk-throttle.c
> +++ b/block/blk-throttle.c
> @@ -451,7 +451,8 @@ static void blk_throtl_update_limit_valid(struct throtl_data *td)
>  	bool low_valid = false;
>  
>  	rcu_read_lock();
> -	blkg_for_each_descendant_post(blkg, pos_css, td->queue->root_blkg) {
> +	blkg_for_each_descendant_post(blkg, pos_css,
> +			td->queue->disk->root_blkg) {
>  		struct throtl_grp *tg = blkg_to_tg(blkg);
>  
>  		if (tg->bps[READ][LIMIT_LOW] || tg->bps[WRITE][LIMIT_LOW] ||
> @@ -1180,7 +1181,7 @@ static void throtl_pending_timer_fn(struct timer_list *t)
>  
>  	spin_lock_irq(&q->queue_lock);
>  
> -	if (!q->root_blkg)
> +	if (!q->disk->root_blkg)
>  		goto out_unlock;
>  
>  	if (throtl_can_upgrade(td, NULL))
> @@ -1322,7 +1323,8 @@ static void tg_conf_updated(struct throtl_grp *tg, bool global)
>  	 * blk-throttle.
>  	 */
>  	blkg_for_each_descendant_pre(blkg, pos_css,
> -			global ? tg->td->queue->root_blkg : tg_to_blkg(tg)) {
> +			global ? tg->td->queue->disk->root_blkg :
> +			tg_to_blkg(tg)) {
>  		struct throtl_grp *this_tg = blkg_to_tg(blkg);
>  		struct throtl_grp *parent_tg;
>  
> @@ -1717,7 +1719,7 @@ void blk_throtl_cancel_bios(struct gendisk *disk)
>  	 * path need RCU protection and to prevent warning from lockdep.
>  	 */
>  	rcu_read_lock();
> -	blkg_for_each_descendant_post(blkg, pos_css, q->root_blkg) {
> +	blkg_for_each_descendant_post(blkg, pos_css, disk->root_blkg) {
>  		struct throtl_grp *tg = blkg_to_tg(blkg);
>  		struct throtl_service_queue *sq = &tg->service_queue;
>  
> @@ -1871,7 +1873,8 @@ static bool throtl_can_upgrade(struct throtl_data *td,
>  		return false;
>  
>  	rcu_read_lock();
> -	blkg_for_each_descendant_post(blkg, pos_css, td->queue->root_blkg) {
> +	blkg_for_each_descendant_post(blkg, pos_css,
> +			td->queue->disk->root_blkg) {
>  		struct throtl_grp *tg = blkg_to_tg(blkg);
>  
>  		if (tg == this_tg)
> @@ -1917,7 +1920,8 @@ static void throtl_upgrade_state(struct throtl_data *td)
>  	td->low_upgrade_time = jiffies;
>  	td->scale = 0;
>  	rcu_read_lock();
> -	blkg_for_each_descendant_post(blkg, pos_css, td->queue->root_blkg) {
> +	blkg_for_each_descendant_post(blkg, pos_css,
> +			td->queue->disk->root_blkg) {
>  		struct throtl_grp *tg = blkg_to_tg(blkg);
>  		struct throtl_service_queue *sq = &tg->service_queue;
>  
> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
> index b87ed829ab9418..d27010c25f75f0 100644
> --- a/include/linux/blkdev.h
> +++ b/include/linux/blkdev.h
> @@ -163,6 +163,11 @@ struct gendisk {
>  	struct timer_rand_state *random;
>  	atomic_t sync_io;		/* RAID */
>  	struct disk_events *ev;
> +#ifdef CONFIG_BLK_CGROUP
> +	DECLARE_BITMAP		(blkcg_pols, BLKCG_MAX_POLS);
> +	struct blkcg_gq		*root_blkg;
> +	struct list_head	blkg_list;
> +#endif
>  #ifdef  CONFIG_BLK_DEV_INTEGRITY
>  	struct kobject integrity_kobj;
>  #endif	/* CONFIG_BLK_DEV_INTEGRITY */
> @@ -481,11 +486,6 @@ struct request_queue {
>  	struct blk_mq_tags	*sched_shared_tags;
>  
>  	struct list_head	icq_list;
> -#ifdef CONFIG_BLK_CGROUP
> -	DECLARE_BITMAP		(blkcg_pols, BLKCG_MAX_POLS);
> -	struct blkcg_gq		*root_blkg;
> -	struct list_head	blkg_list;
> -#endif
>  
>  	struct queue_limits	limits;
>  
> -- 
> 2.39.0
> 

-- 
Regards,
Andreas

SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nürnberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Martje Boudien Moerman
(HRB 36809, AG Nürnberg)

Re: [PATCH 15/15] blk-cgroup: move the cgroup information to struct gendisk

[Hannes Reinecke]

On 1/17/23 09:12, Christoph Hellwig wrote:
> cgroup information only makes sense on a live gendisk that allows
> file system I/O (which includes the raw block device).  So move over
> the cgroup related members.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>   block/bfq-cgroup.c     |  4 ++--
>   block/blk-cgroup.c     | 48 +++++++++++++++++++++---------------------
>   block/blk-cgroup.h     |  2 +-
>   block/blk-iolatency.c  |  2 +-
>   block/blk-throttle.c   | 16 ++++++++------
>   include/linux/blkdev.h | 10 ++++-----
>   6 files changed, 43 insertions(+), 39 deletions(-)
> 
Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare@suse.de                              +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew
Myers, Andrew McDonald, Martje Boudien Moerman

Re: switch blk-cgroup to work on gendisk

[Tejun Heo]

On Tue, Jan 17, 2023 at 09:12:42AM +0100, Christoph Hellwig wrote:
> blk-cgroup works on only on live disks and "file system" I/O from bios.
> This all the information should be in the gendisk, and not the
> request_queue that also exists for pure passthrough request based
> devices.

Can't blk-throttle be used w/ bio based ones tho? I always thought that was
the reason why we didn't move it into rq-qos framework.

Thanks.

-- 
tejun

Re: switch blk-cgroup to work on gendisk

[Christoph Hellwig]

On Thu, Jan 19, 2023 at 07:03:31AM -1000, Tejun Heo wrote:
> On Tue, Jan 17, 2023 at 09:12:42AM +0100, Christoph Hellwig wrote:
> > blk-cgroup works on only on live disks and "file system" I/O from bios.
> > This all the information should be in the gendisk, and not the
> > request_queue that also exists for pure passthrough request based
> > devices.
> 
> Can't blk-throttle be used w/ bio based ones tho? I always thought that was
> the reason why we didn't move it into rq-qos framework.

Yes, it can.  Not sure if my sentence was unclear, but:

 - everything doing non-passthrough I/O only should be in the gendisk
 - everything related to blk-mq, including infrastruture for passthrough
   should remain in the request_queue

The idea that the request_queue will eventually become a blk-mq only
data structure and not exist (or just have a very leight weight stub)
for bio based drivers.

Re: switch blk-cgroup to work on gendisk

[Tejun Heo]

On Thu, Jan 19, 2023 at 06:05:26PM +0100, Christoph Hellwig wrote:
> Yes, it can.  Not sure if my sentence was unclear, but:
> 
>  - everything doing non-passthrough I/O only should be in the gendisk
>  - everything related to blk-mq, including infrastruture for passthrough
>    should remain in the request_queue
> 
> The idea that the request_queue will eventually become a blk-mq only
> data structure and not exist (or just have a very leight weight stub)
> for bio based drivers.

That makes sense. I was thinking about it the other way around. Yeah, genhd
would exist for everybody. request_queue only for the ones which are
actually handling rq's.

Thanks.

-- 
tejun

switch blk-cgroup to work on gendisk v2

[Christoph Hellwig]

Hi all,

blk-cgroup works on only on live disks and "file system" I/O from bios.
This all the information should be in the gendisk, and not the
request_queue that also exists for pure passthrough request based
devices.

Changes since v1:
 - use the local disk variable in wbt_init instead of q->disk
 - various spelling fixes

Diffstat:
 block/bfq-cgroup.c        |   18 ++--
 block/bfq-iosched.c       |    6 -
 block/blk-cgroup-rwstat.c |    2 
 block/blk-cgroup.c        |  185 +++++++++++++++++++++-------------------------
 block/blk-cgroup.h        |   41 ++++------
 block/blk-iocost.c        |   40 ++++-----
 block/blk-iolatency.c     |   41 ++++------
 block/blk-ioprio.c        |    6 -
 block/blk-mq-debugfs.c    |   10 --
 block/blk-rq-qos.c        |   67 ++++++++++++++++
 block/blk-rq-qos.h        |   66 +---------------
 block/blk-stat.c          |    3 
 block/blk-sysfs.c         |    4 
 block/blk-throttle.c      |   31 ++++---
 block/blk-wbt.c           |   39 ++++-----
 block/blk-wbt.h           |   12 +-
 block/genhd.c             |   17 ++--
 include/linux/blkdev.h    |   10 +-
 include/linux/sched.h     |    2 
 kernel/fork.c             |    2 
 mm/swapfile.c             |    2 
 21 files changed, 292 insertions(+), 312 deletions(-)

[PATCH 04/15] blk-cgroup: pin the gendisk in struct blkcg_gq

[Christoph Hellwig]

Currently each blkcg_gq holds a request_queue reference, which is what
is used in the policies.  But a lot of these interfaces will move over to
use a gendisk, so store a disk in struct blkcg_gq and hold a reference to
it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Andreas Herrmann <aherrmann@suse.de>
---
 block/bfq-cgroup.c        |  6 +++---
 block/blk-cgroup-rwstat.c |  2 +-
 block/blk-cgroup.c        | 29 +++++++++++++----------------
 block/blk-cgroup.h        | 11 +++++------
 block/blk-iocost.c        |  2 +-
 block/blk-iolatency.c     |  4 ++--
 block/blk-throttle.c      |  4 ++--
 7 files changed, 27 insertions(+), 31 deletions(-)

diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c
index a6e8da5f5cfdc1..72a033776722c9 100644
--- a/block/bfq-cgroup.c
+++ b/block/bfq-cgroup.c
@@ -407,7 +407,7 @@ static void bfqg_stats_xfer_dead(struct bfq_group *bfqg)
 
 	parent = bfqg_parent(bfqg);
 
-	lockdep_assert_held(&bfqg_to_blkg(bfqg)->q->queue_lock);
+	lockdep_assert_held(&bfqg_to_blkg(bfqg)->disk->queue->queue_lock);
 
 	if (unlikely(!parent))
 		return;
@@ -538,7 +538,7 @@ static void bfq_pd_init(struct blkg_policy_data *pd)
 {
 	struct blkcg_gq *blkg = pd_to_blkg(pd);
 	struct bfq_group *bfqg = blkg_to_bfqg(blkg);
-	struct bfq_data *bfqd = blkg->q->elevator->elevator_data;
+	struct bfq_data *bfqd = blkg->disk->queue->elevator->elevator_data;
 	struct bfq_entity *entity = &bfqg->entity;
 	struct bfq_group_data *d = blkcg_to_bfqgd(blkg->blkcg);
 
@@ -1203,7 +1203,7 @@ static u64 bfqg_prfill_stat_recursive(struct seq_file *sf,
 	struct cgroup_subsys_state *pos_css;
 	u64 sum = 0;
 
-	lockdep_assert_held(&blkg->q->queue_lock);
+	lockdep_assert_held(&blkg->disk->queue->queue_lock);
 
 	rcu_read_lock();
 	blkg_for_each_descendant_pre(pos_blkg, pos_css, blkg) {
diff --git a/block/blk-cgroup-rwstat.c b/block/blk-cgroup-rwstat.c
index 3304e841df7ce9..b8b8c82e667a3b 100644
--- a/block/blk-cgroup-rwstat.c
+++ b/block/blk-cgroup-rwstat.c
@@ -107,7 +107,7 @@ void blkg_rwstat_recursive_sum(struct blkcg_gq *blkg, struct blkcg_policy *pol,
 	struct cgroup_subsys_state *pos_css;
 	unsigned int i;
 
-	lockdep_assert_held(&blkg->q->queue_lock);
+	lockdep_assert_held(&blkg->disk->queue->queue_lock);
 
 	memset(sum, 0, sizeof(*sum));
 	rcu_read_lock();
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 30d493b43f9272..f5a634ed098db0 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -131,8 +131,8 @@ static void blkg_free(struct blkcg_gq *blkg)
 		if (blkg->pd[i])
 			blkcg_policy[i]->pd_free_fn(blkg->pd[i]);
 
-	if (blkg->q)
-		blk_put_queue(blkg->q);
+	if (blkg->disk)
+		put_disk(blkg->disk);
 	free_percpu(blkg->iostat_cpu);
 	percpu_ref_exit(&blkg->refcnt);
 	kfree(blkg);
@@ -245,10 +245,9 @@ static struct blkcg_gq *blkg_alloc(struct blkcg *blkcg, struct gendisk *disk,
 	if (!blkg->iostat_cpu)
 		goto err_free;
 
-	if (!blk_get_queue(disk->queue))
-		goto err_free;
+	get_device(disk_to_dev(disk));
 
-	blkg->q = disk->queue;
+	blkg->disk = disk;
 	INIT_LIST_HEAD(&blkg->q_node);
 	spin_lock_init(&blkg->async_bio_lock);
 	bio_list_init(&blkg->async_bios);
@@ -443,7 +442,7 @@ static void blkg_destroy(struct blkcg_gq *blkg)
 	struct blkcg *blkcg = blkg->blkcg;
 	int i;
 
-	lockdep_assert_held(&blkg->q->queue_lock);
+	lockdep_assert_held(&blkg->disk->queue->queue_lock);
 	lockdep_assert_held(&blkcg->lock);
 
 	/* Something wrong if we are trying to remove same group twice */
@@ -459,7 +458,7 @@ static void blkg_destroy(struct blkcg_gq *blkg)
 
 	blkg->online = false;
 
-	radix_tree_delete(&blkcg->blkg_tree, blkg->q->id);
+	radix_tree_delete(&blkcg->blkg_tree, blkg->disk->queue->id);
 	list_del_init(&blkg->q_node);
 	hlist_del_init_rcu(&blkg->blkcg_node);
 
@@ -547,9 +546,7 @@ static int blkcg_reset_stats(struct cgroup_subsys_state *css,
 
 const char *blkg_dev_name(struct blkcg_gq *blkg)
 {
-	if (!blkg->q->disk || !blkg->q->disk->bdi->dev)
-		return NULL;
-	return bdi_dev_name(blkg->q->disk->bdi);
+	return bdi_dev_name(blkg->disk->bdi);
 }
 
 /**
@@ -581,10 +578,10 @@ void blkcg_print_blkgs(struct seq_file *sf, struct blkcg *blkcg,
 
 	rcu_read_lock();
 	hlist_for_each_entry_rcu(blkg, &blkcg->blkg_list, blkcg_node) {
-		spin_lock_irq(&blkg->q->queue_lock);
-		if (blkcg_policy_enabled(blkg->q, pol))
+		spin_lock_irq(&blkg->disk->queue->queue_lock);
+		if (blkcg_policy_enabled(blkg->disk->queue, pol))
 			total += prfill(sf, blkg->pd[pol->plid], data);
-		spin_unlock_irq(&blkg->q->queue_lock);
+		spin_unlock_irq(&blkg->disk->queue->queue_lock);
 	}
 	rcu_read_unlock();
 
@@ -1008,9 +1005,9 @@ static int blkcg_print_stat(struct seq_file *sf, void *v)
 
 	rcu_read_lock();
 	hlist_for_each_entry_rcu(blkg, &blkcg->blkg_list, blkcg_node) {
-		spin_lock_irq(&blkg->q->queue_lock);
+		spin_lock_irq(&blkg->disk->queue->queue_lock);
 		blkcg_print_one_stat(blkg, sf);
-		spin_unlock_irq(&blkg->q->queue_lock);
+		spin_unlock_irq(&blkg->disk->queue->queue_lock);
 	}
 	rcu_read_unlock();
 	return 0;
@@ -1080,7 +1077,7 @@ static void blkcg_destroy_blkgs(struct blkcg *blkcg)
 	while (!hlist_empty(&blkcg->blkg_list)) {
 		struct blkcg_gq *blkg = hlist_entry(blkcg->blkg_list.first,
 						struct blkcg_gq, blkcg_node);
-		struct request_queue *q = blkg->q;
+		struct request_queue *q = blkg->disk->queue;
 
 		if (need_resched() || !spin_trylock(&q->queue_lock)) {
 			/*
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index f126fe36001eb3..85b267234823ab 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -53,8 +53,7 @@ struct blkg_iostat_set {
 
 /* association between a blk cgroup and a request queue */
 struct blkcg_gq {
-	/* Pointer to the associated request_queue */
-	struct request_queue		*q;
+	struct gendisk			*disk;
 	struct list_head		q_node;
 	struct hlist_node		blkcg_node;
 	struct blkcg			*blkcg;
@@ -251,11 +250,11 @@ static inline struct blkcg_gq *blkg_lookup(struct blkcg *blkcg,
 		return q->root_blkg;
 
 	blkg = rcu_dereference(blkcg->blkg_hint);
-	if (blkg && blkg->q == q)
+	if (blkg && blkg->disk->queue == q)
 		return blkg;
 
 	blkg = radix_tree_lookup(&blkcg->blkg_tree, q->id);
-	if (blkg && blkg->q != q)
+	if (blkg && blkg->disk->queue != q)
 		blkg = NULL;
 	return blkg;
 }
@@ -355,7 +354,7 @@ static inline void blkg_put(struct blkcg_gq *blkg)
 #define blkg_for_each_descendant_pre(d_blkg, pos_css, p_blkg)		\
 	css_for_each_descendant_pre((pos_css), &(p_blkg)->blkcg->css)	\
 		if (((d_blkg) = blkg_lookup(css_to_blkcg(pos_css),	\
-					    (p_blkg)->q)))
+					    (p_blkg)->disk->queue)))
 
 /**
  * blkg_for_each_descendant_post - post-order walk of a blkg's descendants
@@ -370,7 +369,7 @@ static inline void blkg_put(struct blkcg_gq *blkg)
 #define blkg_for_each_descendant_post(d_blkg, pos_css, p_blkg)		\
 	css_for_each_descendant_post((pos_css), &(p_blkg)->blkcg->css)	\
 		if (((d_blkg) = blkg_lookup(css_to_blkcg(pos_css),	\
-					    (p_blkg)->q)))
+					    (p_blkg)->disk->queue)))
 
 bool __blkcg_punt_bio_submit(struct bio *bio);
 
diff --git a/block/blk-iocost.c b/block/blk-iocost.c
index 9694394ed883c4..a2b4e7146be5f1 100644
--- a/block/blk-iocost.c
+++ b/block/blk-iocost.c
@@ -2953,7 +2953,7 @@ static void ioc_pd_init(struct blkg_policy_data *pd)
 {
 	struct ioc_gq *iocg = pd_to_iocg(pd);
 	struct blkcg_gq *blkg = pd_to_blkg(&iocg->pd);
-	struct ioc *ioc = q_to_ioc(blkg->q);
+	struct ioc *ioc = q_to_ioc(blkg->disk->queue);
 	struct ioc_now now;
 	struct blkcg_gq *tblkg;
 	unsigned long flags;
diff --git a/block/blk-iolatency.c b/block/blk-iolatency.c
index ecdc1074183625..b55eac2cf91944 100644
--- a/block/blk-iolatency.c
+++ b/block/blk-iolatency.c
@@ -974,12 +974,12 @@ static void iolatency_pd_init(struct blkg_policy_data *pd)
 {
 	struct iolatency_grp *iolat = pd_to_lat(pd);
 	struct blkcg_gq *blkg = lat_to_blkg(iolat);
-	struct rq_qos *rqos = blkcg_rq_qos(blkg->q);
+	struct rq_qos *rqos = blkcg_rq_qos(blkg->disk->queue);
 	struct blk_iolatency *blkiolat = BLKIOLATENCY(rqos);
 	u64 now = ktime_to_ns(ktime_get());
 	int cpu;
 
-	if (blk_queue_nonrot(blkg->q))
+	if (blk_queue_nonrot(blkg->disk->queue))
 		iolat->ssd = true;
 	else
 		iolat->ssd = false;
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 6fb5a2f9e1eed5..f802d8f9099430 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -388,7 +388,7 @@ static void throtl_pd_init(struct blkg_policy_data *pd)
 {
 	struct throtl_grp *tg = pd_to_tg(pd);
 	struct blkcg_gq *blkg = tg_to_blkg(tg);
-	struct throtl_data *td = blkg->q->td;
+	struct throtl_data *td = blkg->disk->queue->td;
 	struct throtl_service_queue *sq = &tg->service_queue;
 
 	/*
@@ -1175,7 +1175,7 @@ static void throtl_pending_timer_fn(struct timer_list *t)
 
 	/* throtl_data may be gone, so figure out request queue by blkg */
 	if (tg)
-		q = tg->pd.blkg->q;
+		q = tg->pd.blkg->disk->queue;
 	else
 		q = td->queue;
 
-- 
2.39.0

Re: [PATCH 04/15] blk-cgroup: pin the gendisk in struct blkcg_gq

[Tejun Heo]

Hello,

On Tue, Jan 24, 2023 at 07:57:04AM +0100, Christoph Hellwig wrote:
> @@ -245,10 +245,9 @@ static struct blkcg_gq *blkg_alloc(struct blkcg *blkcg, struct gendisk *disk,
>  	if (!blkg->iostat_cpu)
>  		goto err_free;
>  
> -	if (!blk_get_queue(disk->queue))
> -		goto err_free;
> +	get_device(disk_to_dev(disk));

We lose the blk_queue_dying() test here. It'd be great if the patch
description explains why this is safe.

> @@ -547,9 +546,7 @@ static int blkcg_reset_stats(struct cgroup_subsys_state *css,
>  
>  const char *blkg_dev_name(struct blkcg_gq *blkg)
>  {
> -	if (!blkg->q->disk || !blkg->q->disk->bdi->dev)
> -		return NULL;
> -	return bdi_dev_name(blkg->q->disk->bdi);
> +	return bdi_dev_name(blkg->disk->bdi);

This isn't completely trivial like other conversions. Maybe worth mentioning
in the description too?

Thanks.

-- 
tejun