[1/8] md: fix kobject_add error handling

Commit Message

Christoph Hellwig July 12, 2022, 7:03 a.m. UTC

Always use the deferred kobject_put from mddev_put to clean up a mddev.
To make sure that happens properly clear the hold_active on error,
and clear the ->gendisk field and put the disk manually when ->add_disk
fails to avoid a double free.

Fixes: 5e55e2f5fc95 ("[PATCH] md: convert compile time warnings into runtime warnings")
Fixes: 9be68dd7ac0e ("md: add error handling support for add_disk()")
Signed-off-by: Christoph Hellwig <[e-mail]>
---
 drivers/md/md.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

Patch

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 076255ec9ba18..861d6a9481b2e 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -5703,23 +5703,23 @@  static int md_alloc(dev_t dev, char *name)
 	disk->events |= DISK_EVENT_MEDIA_CHANGE;
 	mddev->gendisk = disk;
 	error = add_disk(disk);
-	if (error)
-		goto out_cleanup_disk;
+	if (error) {
+		mddev->gendisk = NULL;
+		put_disk(disk);
+		goto out_unlock_disks_mutex;
+	}
 
 	error = kobject_add(&mddev->kobj, &disk_to_dev(disk)->kobj, "%s", "md");
 	if (error)
-		goto out_del_gendisk;
+		goto out_unlock_disks_mutex;
 
 	kobject_uevent(&mddev->kobj, KOBJ_ADD);
 	mddev->sysfs_state = sysfs_get_dirent_safe(mddev->kobj.sd, "array_state");
 	mddev->sysfs_level = sysfs_get_dirent_safe(mddev->kobj.sd, "level");
-	goto out_unlock_disks_mutex;
 
-out_del_gendisk:
-	del_gendisk(disk);
-out_cleanup_disk:
-	put_disk(disk);
 out_unlock_disks_mutex:
+	if (error)
+		mddev->hold_active = 0;
 	mutex_unlock(&disks_mutex);
 	mddev_put(mddev);
 	return error;