[PATCH-next v2] blk-mq: cleanup unused methods: blk_mq_hw_sysfs_store

[PATCH-next v2] 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>
---
 v2: changed debuffs to debugfs in commit message 
 block/blk-mq-sysfs.c | 23 -----------------------
 1 file changed, 23 deletions(-)

diff --git a/block/blk-mq-sysfs.c b/block/blk-mq-sysfs.c
index 93997d297d42..40450e469ba6 100644
--- a/block/blk-mq-sysfs.c
+++ b/block/blk-mq-sysfs.c
@@ -70,28 +70,6 @@ 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 +128,6 @@ 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 v2] blk-mq: cleanup unused methods: blk_mq_hw_sysfs_store

[Christoph Hellwig]

On Wed, Dec 21, 2022 at 04:34:21PM +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.

Please also remove the now unused store method from
struct blk_mq_hw_ctx_sysfs_entry.