Hello,
On Mon, Jul 01, 2019 at 01:52:35PM +0800, Hillf Danton wrote:
> >WARNING: CPU: 0 PID: 8613 at fs/kernfs/dir.c:493 kernfs_get
> >fs/kernfs/dir.c:493 [inline]
> >WARNING: CPU: 0 PID: 8613 at fs/kernfs/dir.c:493 kernfs_new_node
> >fs/kernfs/dir.c:700 [inline]
> >WARNING: CPU: 0 PID: 8613 at fs/kernfs/dir.c:493
> >kernfs_create_dir_ns+0x205/0x230 fs/kernfs/dir.c:1022
...
> --- a/fs/sysfs/dir.c
> +++ b/fs/sysfs/dir.c
> @@ -53,6 +53,10 @@ int sysfs_create_dir_ns(struct kobject *kobj, const void
> *ns)
> if (!parent)
> return -ENOENT;
>
> + /* create dir if parent is not dying */
> + if (!atomic_inc_not_zero(&parent->count))
> + return -ENOENT;
> +
> kobject_get_ownership(kobj, &uid, &gid);
>
> kn = kernfs_create_dir_ns(parent, kobject_name(kobj),
> @@ -61,10 +65,12 @@ int sysfs_create_dir_ns(struct kobject *kobj, const void
> *ns)
> if (IS_ERR(kn)) {
> if (PTR_ERR(kn) == -EEXIST)
> sysfs_warn_dup(parent, kobject_name(kobj));
> + kernfs_put(parent);
> return PTR_ERR(kn);
> }
>
> kobj->sd = kn;
> + kernfs_put(parent);
I don't think this is the correct fix. It's being called with kobj
whose parent's sysfs node is dangling. It gotta be fixed from the
caller side.
Thanks.
--
tejun
