[PATCH-next v3] blk-mq: cleanup unused methods: blk_mq_hw_sysfs_store

[PATCH-next v3] blk-mq: cleanup unused methods: blk_mq_hw_sysfs_store

[Zhong Jinghua]

We found that the blk_mq_hw_sysfs_store interface has no place to use.
The object default_hw_ctx_attrs using blk_mq_hw_sysfs_ops only uses
the show method and does not use the store method.

Since this patch:
4a46f05ebf99 ("blk-mq: move hctx and ctx counters from sysfs to debugfs")
moved the store method to debugfs, the store method is not used anymore.

So let me do some tiny work to clean up unused code.

Signed-off-by: Zhong Jinghua <zhongjinghua@huawei.com>
---
 v1->v2: changed debuffs to debugfs in commit message
 v2->v3: as suggested by Christoph Hellwig, remove now unused store method
 from struct blk_mq_hw_ctx_sysfs_entry
 block/blk-mq-sysfs.c | 24 ------------------------
 1 file changed, 24 deletions(-)

diff --git a/block/blk-mq-sysfs.c b/block/blk-mq-sysfs.c
index 93997d297d42..847c0151070f 100644
--- a/block/blk-mq-sysfs.c
+++ b/block/blk-mq-sysfs.c
@@ -46,7 +46,6 @@ static void blk_mq_hw_sysfs_release(struct kobject *kobj)
 struct blk_mq_hw_ctx_sysfs_entry {
 	struct attribute attr;
 	ssize_t (*show)(struct blk_mq_hw_ctx *, char *);
-	ssize_t (*store)(struct blk_mq_hw_ctx *, const char *, size_t);
 };
 
 static ssize_t blk_mq_hw_sysfs_show(struct kobject *kobj,
@@ -70,28 +69,6 @@ static ssize_t blk_mq_hw_sysfs_show(struct kobject *kobj,
 	return res;
 }
 
-static ssize_t blk_mq_hw_sysfs_store(struct kobject *kobj,
-				     struct attribute *attr, const char *page,
-				     size_t length)
-{
-	struct blk_mq_hw_ctx_sysfs_entry *entry;
-	struct blk_mq_hw_ctx *hctx;
-	struct request_queue *q;
-	ssize_t res;
-
-	entry = container_of(attr, struct blk_mq_hw_ctx_sysfs_entry, attr);
-	hctx = container_of(kobj, struct blk_mq_hw_ctx, kobj);
-	q = hctx->queue;
-
-	if (!entry->store)
-		return -EIO;
-
-	mutex_lock(&q->sysfs_lock);
-	res = entry->store(hctx, page, length);
-	mutex_unlock(&q->sysfs_lock);
-	return res;
-}
-
 static ssize_t blk_mq_hw_sysfs_nr_tags_show(struct blk_mq_hw_ctx *hctx,
 					    char *page)
 {
@@ -150,7 +127,6 @@ ATTRIBUTE_GROUPS(default_hw_ctx);
 
 static const struct sysfs_ops blk_mq_hw_sysfs_ops = {
 	.show	= blk_mq_hw_sysfs_show,
-	.store	= blk_mq_hw_sysfs_store,
 };
 
 static struct kobj_type blk_mq_ktype = {
-- 
2.31.1

Re: [PATCH-next v3] blk-mq: cleanup unused methods: blk_mq_hw_sysfs_store

[Ming Lei]

On Sat, Jan 28, 2023 at 11:04:19AM +0800, Zhong Jinghua wrote:
> We found that the blk_mq_hw_sysfs_store interface has no place to use.
> The object default_hw_ctx_attrs using blk_mq_hw_sysfs_ops only uses
> the show method and does not use the store method.
> 
> Since this patch:
> 4a46f05ebf99 ("blk-mq: move hctx and ctx counters from sysfs to debugfs")
> moved the store method to debugfs, the store method is not used anymore.
> 
> So let me do some tiny work to clean up unused code.
> 
> Signed-off-by: Zhong Jinghua <zhongjinghua@huawei.com>

Reviewed-by: Ming Lei <ming.lei@redhat.com>

Thanks,
Ming

Re: [PATCH-next v3] blk-mq: cleanup unused methods: blk_mq_hw_sysfs_store

[Jens Axboe]

On Sat, 28 Jan 2023 11:04:19 +0800, Zhong Jinghua wrote:
> We found that the blk_mq_hw_sysfs_store interface has no place to use.
> The object default_hw_ctx_attrs using blk_mq_hw_sysfs_ops only uses
> the show method and does not use the store method.
> 
> Since this patch:
> 4a46f05ebf99 ("blk-mq: move hctx and ctx counters from sysfs to debugfs")
> moved the store method to debugfs, the store method is not used anymore.
> 
> [...]

Applied, thanks!

[1/1] blk-mq: cleanup unused methods: blk_mq_hw_sysfs_store
      commit: 52627f3c2935342dbceb2ba6fd710f1deac627a1

Best regards,
-- 
Jens Axboe