block: return void from the queue_sysfs_entry load_module method

Requesting a module either succeeds or does nothing, return an error from
this method does not make sense.

Also move the load_module after the store method in the struct
declaration to keep the important show and store methods together.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20241008050841.104602-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Author: Christoph Hellwig

block/blk-sysfs.c

@@ -23,8 +23,8 @@
 struct queue_sysfs_entry {
 	struct attribute attr;
 	ssize_t (*show)(struct gendisk *disk, char *page);
-	int (*load_module)(struct gendisk *disk, const char *page, size_t count);
 	ssize_t (*store)(struct gendisk *disk, const char *page, size_t count);
+	void (*load_module)(struct gendisk *disk, const char *page, size_t count);
 };
 
 static ssize_t
@@ -684,11 +684,8 @@ queue_attr_store(struct kobject *kobj, struct attribute *attr,
 	 * queue to ensure that the module file can be read when the request
 	 * queue is the one for the device storing the module file.
 	 */
-	if (entry->load_module) {
-		res = entry->load_module(disk, page, length);
-		if (res)
-			return res;
-	}
+	if (entry->load_module)
+		entry->load_module(disk, page, length);
 
 	blk_mq_freeze_queue(q);
 	mutex_lock(&q->sysfs_lock);

block/elevator.c

@@ -704,15 +704,15 @@ static int elevator_change(struct request_queue *q, const char *elevator_name)
 	return ret;
 }
 
-int elv_iosched_load_module(struct gendisk *disk, const char *buf,
-			    size_t count)
+void elv_iosched_load_module(struct gendisk *disk, const char *buf,
+			     size_t count)
 {
 	char elevator_name[ELV_NAME_MAX];
 	struct elevator_type *found;
 	const char *name;
 
 	if (!elv_support_iosched(disk->queue))
-		return -EOPNOTSUPP;
+		return;
 
 	strscpy(elevator_name, buf, sizeof(elevator_name));
 	name = strstrip(elevator_name);
@@ -723,8 +723,6 @@ int elv_iosched_load_module(struct gendisk *disk, const char *buf,
 
 	if (!found)
 		request_module("%s-iosched", name);
-
-	return 0;
 }
 
 ssize_t elv_iosched_store(struct gendisk *disk, const char *buf,

block/elevator.h

@@ -148,8 +148,8 @@ extern void elv_unregister(struct elevator_type *);
  * io scheduler sysfs switching
  */
 ssize_t elv_iosched_show(struct gendisk *disk, char *page);
-int elv_iosched_load_module(struct gendisk *disk, const char *page,
-			    size_t count);
+void elv_iosched_load_module(struct gendisk *disk, const char *page,
+		size_t count);
 ssize_t elv_iosched_store(struct gendisk *disk, const char *page, size_t count);
 
 extern bool elv_bio_merge_ok(struct request *, struct bio *);