Commit ca39f750 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

md: fix mddev->kobj lifetime 



Once a kobject is initialized, the containing object should not be
directly freed.  So delay initialization until it is added.  Also
remove the kobject_del call as the last put will remove the kobject as
well.  The explicitly delete isn't needed here, and dropping it will
simplify further fixes.

With this md_free now does not need to check that ->gendisk is non-NULL
as it is always set by the time that kobject_init is called on
mddev->kobj.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarLogan Gunthorpe <logang@deltatee.com>
Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
Signed-off-by: default avatarSong Liu <song@kernel.org>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent ee1aa06b

drivers/md/md.c

+4 −6
Original line number Diff line number Diff line
@@ -678,7 +678,6 @@ static void md_safemode_timeout(struct timer_list *t); 


void mddev_init(struct mddev *mddev)

{

	kobject_init(&mddev->kobj, &md_ktype);

	mutex_init(&mddev->open_mutex);

	mutex_init(&mddev->reconfig_mutex);

	mutex_init(&mddev->bitmap_info.mutex);
@@ -5590,10 +5589,9 @@ static void md_free(struct kobject *ko) 
	if (mddev->sysfs_level)

		sysfs_put(mddev->sysfs_level);



	if (mddev->gendisk) {

	del_gendisk(mddev->gendisk);

	put_disk(mddev->gendisk);

	}



	percpu_ref_exit(&mddev->writes_pending);



	bioset_exit(&mddev->bio_set);
@@ -5617,7 +5615,6 @@ static void mddev_delayed_delete(struct work_struct *ws) 
{

	struct mddev *mddev = container_of(ws, struct mddev, del_work);



	kobject_del(&mddev->kobj);

	kobject_put(&mddev->kobj);

}
@@ -5719,6 +5716,7 @@ int md_alloc(dev_t dev, char *name) 
	if (error)

		goto out_cleanup_disk;



	kobject_init(&mddev->kobj, &md_ktype);

	error = kobject_add(&mddev->kobj, &disk_to_dev(disk)->kobj, "%s", "md");

	if (error)

		goto out_del_gendisk;