[PATCH V2] nilfs2: Fix reference count leak in nilfs_sysfs_create_device_group

[wu000273]

From: Qiushi Wu <wu000...@umn.edu>

kobject_init_and_add() takes reference even when it fails.
In nilfs_sysfs_create_device_group(), the memory allocated by
kobject_init_and_add() is not freed when kobject_init_and_add()
fails. Fix this issue by calling kobject_put() to clean up the
kobject.

Fixes: da7141fb78db ("nilfs2: add /sys/fs/nilfs2/<device> group")
Signed-off-by: Qiushi Wu <wu000...@umn.edu>
---
 V2: using kobject_put() to handle kobject_init_and_add() instead of
 kobject_del().

 fs/nilfs2/sysfs.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/nilfs2/sysfs.c b/fs/nilfs2/sysfs.c
index e60be7bb55b0..8416f915d118 100644
--- a/fs/nilfs2/sysfs.c
+++ b/fs/nilfs2/sysfs.c
@@ -999,8 +999,10 @@ int nilfs_sysfs_create_device_group(struct super_block *sb)
        init_completion(&nilfs->ns_dev_kobj_unregister);
        err = kobject_init_and_add(&nilfs->ns_dev_kobj, &nilfs_dev_ktype, NULL,
                                    "%s", sb->s_id);
-       if (err)
+       if (err) {
+               kobject_put(&nilfs->ns_dev_kobj);
                goto free_dev_subgroups;
+       }
 
        err = nilfs_sysfs_create_mounted_snapshots_group(nilfs);
        if (err)
-- 
2.17.1