[PATCH 02/23] uts: Use generic ns_common::count

[Kirill Tkhai]

Convert uts namespace to use generic counter instead of kref.

Signed-off-by: Kirill Tkhai <ktk...@virtuozzo.com>
---
 include/linux/utsname.h |    9 ++++-----
 init/version.c          |    2 +-
 kernel/utsname.c        |    7 ++-----
 3 files changed, 7 insertions(+), 11 deletions(-)

diff --git a/include/linux/utsname.h b/include/linux/utsname.h
index 44429d9142ca..2b1737c9b244 100644
--- a/include/linux/utsname.h
+++ b/include/linux/utsname.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>
@@ -22,7 +21,6 @@ struct user_namespace;
 extern struct user_namespace init_user_ns;
 
 struct uts_namespace {
-       struct kref kref;
        struct new_utsname name;
        struct user_namespace *user_ns;
        struct ucounts *ucounts;
@@ -33,16 +31,17 @@ extern struct uts_namespace init_uts_ns;
 #ifdef CONFIG_UTS_NS
 static inline void get_uts_ns(struct uts_namespace *ns)
 {
-       kref_get(&ns->kref);
+       refcount_inc(&ns->ns.count);
 }
 
 extern struct uts_namespace *copy_utsname(unsigned long flags,
        struct user_namespace *user_ns, struct uts_namespace *old_ns);
-extern void free_uts_ns(struct kref *kref);
+extern void free_uts_ns(struct uts_namespace *ns);
 
 static inline void put_uts_ns(struct uts_namespace *ns)
 {
-       kref_put(&ns->kref, free_uts_ns);
+       if (refcount_dec_and_test(&ns->ns.count))
+               free_uts_ns(ns);
 }
 
 void uts_ns_init(void);
diff --git a/init/version.c b/init/version.c
index cba341161b58..80d2b7566b39 100644
--- a/init/version.c
+++ b/init/version.c
@@ -25,7 +25,7 @@ int version_string(LINUX_VERSION_CODE);
 #endif
 
 struct uts_namespace init_uts_ns = {
-       .kref = KREF_INIT(2),
+       .ns.count = REFCOUNT_INIT(2),
        .name = {
                .sysname        = UTS_SYSNAME,
                .nodename       = UTS_NODENAME,
diff --git a/kernel/utsname.c b/kernel/utsname.c
index e488d0e2ab45..b1ac3ca870f2 100644
--- a/kernel/utsname.c
+++ b/kernel/utsname.c
@@ -33,7 +33,7 @@ static struct uts_namespace *create_uts_ns(void)
 
        uts_ns = kmem_cache_alloc(uts_ns_cache, GFP_KERNEL);
        if (uts_ns)
-               kref_init(&uts_ns->kref);
+               refcount_set(&uts_ns->ns.count, 1);
        return uts_ns;
 }
 
@@ -103,11 +103,8 @@ struct uts_namespace *copy_utsname(unsigned long flags,
        return new_ns;
 }
 
-void free_uts_ns(struct kref *kref)
+void free_uts_ns(struct uts_namespace *ns)
 {
-       struct uts_namespace *ns;
-
-       ns = container_of(kref, struct uts_namespace, kref);
        dec_uts_namespaces(ns->ucounts);
        put_user_ns(ns->user_ns);
        ns_free_inum(&ns->ns);