new helpers: ns_alloc_inum/ns_free_inum

take struct ns_common *, for now simply wrappers around proc_{alloc,free}_inum()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/namespace.c

@@ -2645,7 +2645,7 @@ long do_mount(const char *dev_name, const char __user *dir_name,
 
 static void free_mnt_ns(struct mnt_namespace *ns)
 {
-	proc_free_inum(ns->ns.inum);
+	ns_free_inum(&ns->ns);
 	put_user_ns(ns->user_ns);
 	kfree(ns);
 }
@@ -2667,7 +2667,7 @@ static struct mnt_namespace *alloc_mnt_ns(struct user_namespace *user_ns)
 	new_ns = kmalloc(sizeof(struct mnt_namespace), GFP_KERNEL);
 	if (!new_ns)
 		return ERR_PTR(-ENOMEM);
-	ret = proc_alloc_inum(&new_ns->ns.inum);
+	ret = ns_alloc_inum(&new_ns->ns);
 	if (ret) {
 		kfree(new_ns);
 		return ERR_PTR(ret);

include/linux/proc_ns.h

@@ -71,4 +71,7 @@ static inline bool proc_ns_inode(struct inode *inode) { return false; }
 
 #endif /* CONFIG_PROC_FS */
 
+#define ns_alloc_inum(ns) proc_alloc_inum(&(ns)->inum)
+#define ns_free_inum(ns) proc_free_inum((ns)->inum)
+
 #endif /* _LINUX_PROC_NS_H */

ipc/namespace.c

@@ -26,7 +26,7 @@ static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns,
 	if (ns == NULL)
 		return ERR_PTR(-ENOMEM);
 
-	err = proc_alloc_inum(&ns->ns.inum);
+	err = ns_alloc_inum(&ns->ns);
 	if (err) {
 		kfree(ns);
 		return ERR_PTR(err);
@@ -35,7 +35,7 @@ static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns,
 	atomic_set(&ns->count, 1);
 	err = mq_init_ns(ns);
 	if (err) {
-		proc_free_inum(ns->ns.inum);
+		ns_free_inum(&ns->ns);
 		kfree(ns);
 		return ERR_PTR(err);
 	}
@@ -119,7 +119,7 @@ static void free_ipc_ns(struct ipc_namespace *ns)
 	 */
 	ipcns_notify(IPCNS_REMOVED);
 	put_user_ns(ns->user_ns);
-	proc_free_inum(ns->ns.inum);
+	ns_free_inum(&ns->ns);
 	kfree(ns);
 }
 

kernel/pid_namespace.c

@@ -105,7 +105,7 @@ static struct pid_namespace *create_pid_namespace(struct user_namespace *user_ns
 	if (ns->pid_cachep == NULL)
 		goto out_free_map;
 
-	err = proc_alloc_inum(&ns->ns.inum);
+	err = ns_alloc_inum(&ns->ns);
 	if (err)
 		goto out_free_map;
 
@@ -142,7 +142,7 @@ static void destroy_pid_namespace(struct pid_namespace *ns)
 {
 	int i;
 
-	proc_free_inum(ns->ns.inum);
+	ns_free_inum(&ns->ns);
 	for (i = 0; i < PIDMAP_ENTRIES; i++)
 		kfree(ns->pidmap[i].page);
 	put_user_ns(ns->user_ns);

kernel/user_namespace.c

@@ -86,7 +86,7 @@ int create_user_ns(struct cred *new)
 	if (!ns)
 		return -ENOMEM;
 
-	ret = proc_alloc_inum(&ns->ns.inum);
+	ret = ns_alloc_inum(&ns->ns);
 	if (ret) {
 		kmem_cache_free(user_ns_cachep, ns);
 		return ret;
@@ -136,7 +136,7 @@ void free_user_ns(struct user_namespace *ns)
 #ifdef CONFIG_PERSISTENT_KEYRINGS
 		key_put(ns->persistent_keyring_register);
 #endif
-		proc_free_inum(ns->ns.inum);
+		ns_free_inum(&ns->ns);
 		kmem_cache_free(user_ns_cachep, ns);
 		ns = parent;
 	} while (atomic_dec_and_test(&parent->count));

kernel/utsname.c

@@ -42,7 +42,7 @@ static struct uts_namespace *clone_uts_ns(struct user_namespace *user_ns,
 	if (!ns)
 		return ERR_PTR(-ENOMEM);
 
-	err = proc_alloc_inum(&ns->ns.inum);
+	err = ns_alloc_inum(&ns->ns);
 	if (err) {
 		kfree(ns);
 		return ERR_PTR(err);
@@ -84,7 +84,7 @@ void free_uts_ns(struct kref *kref)
 
 	ns = container_of(kref, struct uts_namespace, kref);
 	put_user_ns(ns->user_ns);
-	proc_free_inum(ns->ns.inum);
+	ns_free_inum(&ns->ns);
 	kfree(ns);
 }
 

net/core/net_namespace.c

@@ -386,12 +386,12 @@ EXPORT_SYMBOL_GPL(get_net_ns_by_pid);
 
 static __net_init int net_ns_net_init(struct net *net)
 {
-	return proc_alloc_inum(&net->ns.inum);
+	return ns_alloc_inum(&net->ns);
 }
 
 static __net_exit void net_ns_net_exit(struct net *net)
 {
-	proc_free_inum(net->ns.inum);
+	ns_free_inum(&net->ns);
 }
 
 static struct pernet_operations __net_initdata net_ns_ops = {