[PATCH 04/23] pid: Use generic ns_common::count

[Kirill Tkhai]

Convert pid namespace to use generic counter.

Signed-off-by: Kirill Tkhai <ktk...@virtuozzo.com>
---
 include/linux/pid_namespace.h |    4 +---
 kernel/pid.c                  |    2 +-
 kernel/pid_namespace.c        |   13 +++----------
 3 files changed, 5 insertions(+), 14 deletions(-)

diff --git a/include/linux/pid_namespace.h b/include/linux/pid_namespace.h
index 5a5cb45ac57e..7c7e627503d2 100644
--- a/include/linux/pid_namespace.h
+++ b/include/linux/pid_namespace.h
@@ -8,7 +8,6 @@
 #include <linux/workqueue.h>
 #include <linux/threads.h>
 #include <linux/nsproxy.h>
-#include <linux/kref.h>
 #include <linux/ns_common.h>
 #include <linux/idr.h>
 
@@ -18,7 +17,6 @@
 struct fs_pin;
 
 struct pid_namespace {
-       struct kref kref;
        struct idr idr;
        struct rcu_head rcu;
        unsigned int pid_allocated;
@@ -43,7 +41,7 @@ extern struct pid_namespace init_pid_ns;
 static inline struct pid_namespace *get_pid_ns(struct pid_namespace *ns)
 {
        if (ns != &init_pid_ns)
-               kref_get(&ns->kref);
+               refcount_inc(&ns->ns.count);
        return ns;
 }
 
diff --git a/kernel/pid.c b/kernel/pid.c
index de9d29c41d77..3b9e67736ef4 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -72,7 +72,7 @@ int pid_max_max = PID_MAX_LIMIT;
  * the scheme scales to up to 4 million PIDs, runtime.
  */
 struct pid_namespace init_pid_ns = {
-       .kref = KREF_INIT(2),
+       .ns.count = REFCOUNT_INIT(2),
        .idr = IDR_INIT(init_pid_ns.idr),
        .pid_allocated = PIDNS_ADDING,
        .level = 0,
diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c
index 0e5ac162c3a8..d02dc1696edf 100644
--- a/kernel/pid_namespace.c
+++ b/kernel/pid_namespace.c
@@ -102,7 +102,7 @@ static struct pid_namespace *create_pid_namespace(struct 
user_namespace *user_ns
                goto out_free_idr;
        ns->ns.ops = &pidns_operations;
 
-       kref_init(&ns->kref);
+       refcount_set(&ns->ns.count, 1);
        ns->level = level;
        ns->parent = get_pid_ns(parent_pid_ns);
        ns->user_ns = get_user_ns(user_ns);
@@ -148,22 +148,15 @@ struct pid_namespace *copy_pid_ns(unsigned long flags,
        return create_pid_namespace(user_ns, old_ns);
 }
 
-static void free_pid_ns(struct kref *kref)
-{
-       struct pid_namespace *ns;
-
-       ns = container_of(kref, struct pid_namespace, kref);
-       destroy_pid_namespace(ns);
-}
-
 void put_pid_ns(struct pid_namespace *ns)
 {
        struct pid_namespace *parent;
 
        while (ns != &init_pid_ns) {
                parent = ns->parent;
-               if (!kref_put(&ns->kref, free_pid_ns))
+               if (!refcount_dec_and_test(&ns->ns.count))
                        break;
+               destroy_pid_namespace(ns);
                ns = parent;
        }
 }