block: add the events* attributes to disk_attrs

Add the events attributes to the disk_attrs array, which ensures they are
added by the driver core when the device is created rather than adding
them after the device has been added, which is racy versus uevents and
requires more boilerplate code.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NHannes Reinecke <hare@suse.de>
Link: https://lore.kernel.org/r/20210624073843.251178-3-hch@lst.deSigned-off-by: NJens Axboe <axboe@kernel.dk>

block/blk.h

@@ -364,5 +364,8 @@ void disk_alloc_events(struct gendisk *disk);
 void disk_add_events(struct gendisk *disk);
 void disk_del_events(struct gendisk *disk);
 void disk_release_events(struct gendisk *disk);
+extern struct device_attribute dev_attr_events;
+extern struct device_attribute dev_attr_events_async;
+extern struct device_attribute dev_attr_events_poll_msecs;
 
 #endif /* BLK_INTERNAL_H */

block/disk-events.c

@@ -368,18 +368,10 @@ static ssize_t disk_events_poll_msecs_store(struct device *dev,
 	return count;
 }
 
-static const DEVICE_ATTR(events, 0444, disk_events_show, NULL);
-static const DEVICE_ATTR(events_async, 0444, disk_events_async_show, NULL);
-static const DEVICE_ATTR(events_poll_msecs, 0644,
-			 disk_events_poll_msecs_show,
-			 disk_events_poll_msecs_store);
-
-static const struct attribute *disk_events_attrs[] = {
-	&dev_attr_events.attr,
-	&dev_attr_events_async.attr,
-	&dev_attr_events_poll_msecs.attr,
-	NULL,
-};
+DEVICE_ATTR(events, 0444, disk_events_show, NULL);
+DEVICE_ATTR(events_async, 0444, disk_events_async_show, NULL);
+DEVICE_ATTR(events_poll_msecs, 0644, disk_events_poll_msecs_show,
+	    disk_events_poll_msecs_store);
 
 /*
  * The default polling interval can be specified by the kernel
@@ -444,11 +436,6 @@ void disk_alloc_events(struct gendisk *disk)
 
 void disk_add_events(struct gendisk *disk)
 {
-	/* FIXME: error handling */
-	if (sysfs_create_files(&disk_to_dev(disk)->kobj, disk_events_attrs) < 0)
-		pr_warn("%s: failed to create sysfs files for events\n",
-			disk->disk_name);
-
 	if (!disk->ev)
 		return;
 
@@ -472,8 +459,6 @@ void disk_del_events(struct gendisk *disk)
 		list_del_init(&disk->ev->node);
 		mutex_unlock(&disk_events_mutex);
 	}
-
-	sysfs_remove_files(&disk_to_dev(disk)->kobj, disk_events_attrs);
 }
 
 void disk_release_events(struct gendisk *disk)

block/genhd.c

@@ -1022,6 +1022,9 @@ static struct attribute *disk_attrs[] = {
 	&dev_attr_stat.attr,
 	&dev_attr_inflight.attr,
 	&dev_attr_badblocks.attr,
+	&dev_attr_events.attr,
+	&dev_attr_events_async.attr,
+	&dev_attr_events_poll_msecs.attr,
 #ifdef CONFIG_FAIL_MAKE_REQUEST
 	&dev_attr_fail.attr,
 #endif