block: simplify blktrace sysfs attribute creation

Add the trace attributes to the default gendisk attributes, just like
we already do for partitions.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20220628171850.1313069-2-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-sysfs.c

@@ -810,21 +810,14 @@ int blk_register_queue(struct gendisk *disk)
 	struct device *dev = disk_to_dev(disk);
 	struct request_queue *q = disk->queue;
 
-	ret = blk_trace_init_sysfs(dev);
-	if (ret)
-		return ret;
-
 	mutex_lock(&q->sysfs_dir_lock);
 
 	ret = kobject_add(&q->kobj, kobject_get(&dev->kobj), "%s", "queue");
-	if (ret < 0) {
-		blk_trace_remove_sysfs(dev);
+	if (ret < 0)
 		goto unlock;
-	}
 
 	ret = sysfs_create_group(&q->kobj, &queue_attr_group);
 	if (ret) {
-		blk_trace_remove_sysfs(dev);
 		kobject_del(&q->kobj);
 		kobject_put(&dev->kobj);
 		goto unlock;
@@ -890,7 +883,6 @@ int blk_register_queue(struct gendisk *disk)
 	mutex_unlock(&q->sysfs_lock);
 	mutex_unlock(&q->sysfs_dir_lock);
 	kobject_del(&q->kobj);
-	blk_trace_remove_sysfs(dev);
 	kobject_put(&dev->kobj);
 
 	return ret;
@@ -931,7 +923,6 @@ void blk_unregister_queue(struct gendisk *disk)
 	if (queue_is_mq(q))
 		blk_mq_unregister_dev(disk_to_dev(disk), q);
 	blk_crypto_sysfs_unregister(q);
-	blk_trace_remove_sysfs(disk_to_dev(disk));
 
 	mutex_lock(&q->sysfs_lock);
 	elv_unregister_queue(q);

block/blk.h

@@ -452,6 +452,8 @@ extern struct device_attribute dev_attr_events;
 extern struct device_attribute dev_attr_events_async;
 extern struct device_attribute dev_attr_events_poll_msecs;
 
+extern struct attribute_group blk_trace_attr_group;
+
 long blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg);
 long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg);
 

block/genhd.c

@@ -1134,6 +1134,9 @@ static struct attribute_group disk_attr_group = {
 
 static const struct attribute_group *disk_attr_groups[] = {
 	&disk_attr_group,
+#ifdef CONFIG_BLK_DEV_IO_TRACE
+	&blk_trace_attr_group,
+#endif
 	NULL
 };
 

block/partitions/core.c

@@ -9,7 +9,6 @@
 #include <linux/slab.h>
 #include <linux/ctype.h>
 #include <linux/vmalloc.h>
-#include <linux/blktrace_api.h>
 #include <linux/raid/detect.h>
 #include "check.h"
 

include/linux/blktrace_api.h

@@ -77,10 +77,6 @@ extern int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
 			   char __user *arg);
 extern int blk_trace_startstop(struct request_queue *q, int start);
 extern int blk_trace_remove(struct request_queue *q);
-extern void blk_trace_remove_sysfs(struct device *dev);
-extern int blk_trace_init_sysfs(struct device *dev);
-
-extern struct attribute_group blk_trace_attr_group;
 
 #else /* !CONFIG_BLK_DEV_IO_TRACE */
 # define blk_trace_ioctl(bdev, cmd, arg)		(-ENOTTY)
@@ -91,13 +87,7 @@ extern struct attribute_group blk_trace_attr_group;
 # define blk_trace_remove(q)				(-ENOTTY)
 # define blk_add_trace_msg(q, fmt, ...)			do { } while (0)
 # define blk_add_cgroup_trace_msg(q, cg, fmt, ...)	do { } while (0)
-# define blk_trace_remove_sysfs(dev)			do { } while (0)
 # define blk_trace_note_message_enabled(q)		(false)
-static inline int blk_trace_init_sysfs(struct device *dev)
-{
-	return 0;
-}
-
 #endif /* CONFIG_BLK_DEV_IO_TRACE */
 
 #ifdef CONFIG_COMPAT

kernel/trace/blktrace.c

@@ -1867,17 +1867,6 @@ static ssize_t sysfs_blk_trace_attr_store(struct device *dev,
 out:
 	return ret ? ret : count;
 }
-
-int blk_trace_init_sysfs(struct device *dev)
-{
-	return sysfs_create_group(&dev->kobj, &blk_trace_attr_group);
-}
-
-void blk_trace_remove_sysfs(struct device *dev)
-{
-	sysfs_remove_group(&dev->kobj, &blk_trace_attr_group);
-}
-
 #endif /* CONFIG_BLK_DEV_IO_TRACE */
 
 #ifdef CONFIG_EVENT_TRACING