On Thu, Jul 30, 2020 at 03:00:03PM +0300, Kirill Tkhai wrote:
> Convert time namespace to use generic counter.
>
> Signed-off-by: Kirill Tkhai <ktk...@virtuozzo.com>
> ---
Looks good!
Acked-by: Christian Brauner <christian.brau...@ubuntu.com>
> include/linux/time_namespace.h | 9 ++++-----
> kernel/time/namespace.c | 9 +++------
> 2 files changed, 7 insertions(+), 11 deletions(-)
>
> diff --git a/include/linux/time_namespace.h b/include/linux/time_namespace.h
> index 5b6031385db0..a51ffc089219 100644
> --- a/include/linux/time_namespace.h
> +++ b/include/linux/time_namespace.h
> @@ -4,7 +4,6 @@
>
>
> #include <linux/sched.h>
> -#include <linux/kref.h>
> #include <linux/nsproxy.h>
> #include <linux/ns_common.h>
> #include <linux/err.h>
> @@ -18,7 +17,6 @@ struct timens_offsets {
> };
>
> struct time_namespace {
> - struct kref kref;
> struct user_namespace *user_ns;
> struct ucounts *ucounts;
> struct ns_common ns;
> @@ -37,20 +35,21 @@ extern void timens_commit(struct task_struct *tsk, struct
> time_namespace *ns);
>
> static inline struct time_namespace *get_time_ns(struct time_namespace *ns)
> {
> - kref_get(&ns->kref);
> + refcount_inc(&ns->ns.count);
> return ns;
> }
>
> struct time_namespace *copy_time_ns(unsigned long flags,
> struct user_namespace *user_ns,
> struct time_namespace *old_ns);
> -void free_time_ns(struct kref *kref);
> +void free_time_ns(struct time_namespace *ns);
> int timens_on_fork(struct nsproxy *nsproxy, struct task_struct *tsk);
> struct vdso_data *arch_get_vdso_data(void *vvar_page);
>
> static inline void put_time_ns(struct time_namespace *ns)
> {
> - kref_put(&ns->kref, free_time_ns);
> + if (refcount_dec_and_test(&ns->ns.count))
> + free_time_ns(ns);
> }
>
> void proc_timens_show_offsets(struct task_struct *p, struct seq_file *m);
> diff --git a/kernel/time/namespace.c b/kernel/time/namespace.c
> index afc65e6be33e..c4c829eb3511 100644
> --- a/kernel/time/namespace.c
> +++ b/kernel/time/namespace.c
> @@ -92,7 +92,7 @@ static struct time_namespace *clone_time_ns(struct
> user_namespace *user_ns,
> if (!ns)
> goto fail_dec;
>
> - kref_init(&ns->kref);
> + refcount_set(&ns->ns.count, 1);
>
> ns->vvar_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
> if (!ns->vvar_page)
> @@ -226,11 +226,8 @@ static void timens_set_vvar_page(struct task_struct
> *task,
> mutex_unlock(&offset_lock);
> }
>
> -void free_time_ns(struct kref *kref)
> +void free_time_ns(struct time_namespace *ns)
> {
> - struct time_namespace *ns;
> -
> - ns = container_of(kref, struct time_namespace, kref);
> dec_time_namespaces(ns->ucounts);
> put_user_ns(ns->user_ns);
> ns_free_inum(&ns->ns);
> @@ -464,7 +461,7 @@ const struct proc_ns_operations
> timens_for_children_operations = {
> };
>
> struct time_namespace init_time_ns = {
> - .kref = KREF_INIT(3),
> + .ns.count = REFCOUNT_INIT(3),
> .user_ns = &init_user_ns,
> .ns.inum = PROC_TIME_INIT_INO,
> .ns.ops = &timens_operations,
>
>
