copy address of proc_ns_ops into ns_common

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/namespace.c

@@ -2672,6 +2672,7 @@ static struct mnt_namespace *alloc_mnt_ns(struct user_namespace *user_ns)
 		kfree(new_ns);
 		return ERR_PTR(ret);
 	}
+	new_ns->ns.ops = &mntns_operations;
 	new_ns->seq = atomic64_add_return(1, &mnt_ns_seq);
 	atomic_set(&new_ns->count, 1);
 	new_ns->root = NULL;

fs/proc/inode.c

@@ -32,7 +32,6 @@ static void proc_evict_inode(struct inode *inode)
 {
 	struct proc_dir_entry *de;
 	struct ctl_table_header *head;
-	const struct proc_ns_operations *ns_ops;
 	struct ns_common *ns;
 
 	truncate_inode_pages_final(&inode->i_data);
@@ -51,10 +50,9 @@ static void proc_evict_inode(struct inode *inode)
 		sysctl_head_put(head);
 	}
 	/* Release any associated namespace */
-	ns_ops = PROC_I(inode)->ns.ns_ops;
 	ns = PROC_I(inode)->ns.ns;
-	if (ns_ops && ns)
-		ns_ops->put(ns);
+	if (ns && ns->ops)
+		ns->ops->put(ns);
 }
 
 static struct kmem_cache * proc_inode_cachep;

include/linux/ns_common.h

@@ -1,7 +1,10 @@
 #ifndef _LINUX_NS_COMMON_H
 #define _LINUX_NS_COMMON_H
 
+struct proc_ns_operations;
+
 struct ns_common {
+	const struct proc_ns_operations *ops;
 	unsigned int inum;
 };
 

init/version.c

@@ -36,6 +36,9 @@ struct uts_namespace init_uts_ns = {
 	},
 	.user_ns = &init_user_ns,
 	.ns.inum = PROC_UTS_INIT_INO,
+#ifdef CONFIG_UTS_NS
+	.ns.ops = &utsns_operations,
+#endif
 };
 EXPORT_SYMBOL_GPL(init_uts_ns);
 

ipc/msgutil.c

@@ -32,6 +32,9 @@ struct ipc_namespace init_ipc_ns = {
 	.count		= ATOMIC_INIT(1),
 	.user_ns = &init_user_ns,
 	.ns.inum = PROC_IPC_INIT_INO,
+#ifdef CONFIG_IPC_NS
+	.ns.ops = &ipcns_operations,
+#endif
 };
 
 atomic_t nr_ipc_ns = ATOMIC_INIT(1);

ipc/namespace.c

@@ -31,6 +31,7 @@ static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns,
 		kfree(ns);
 		return ERR_PTR(err);
 	}
+	ns->ns.ops = &ipcns_operations;
 
 	atomic_set(&ns->count, 1);
 	err = mq_init_ns(ns);

kernel/nsproxy.c

@@ -220,11 +220,11 @@ void exit_task_namespaces(struct task_struct *p)
 
 SYSCALL_DEFINE2(setns, int, fd, int, nstype)
 {
-	const struct proc_ns_operations *ops;
 	struct task_struct *tsk = current;
 	struct nsproxy *new_nsproxy;
 	struct proc_ns *ei;
 	struct file *file;
+	struct ns_common *ns;
 	int err;
 
 	file = proc_ns_fget(fd);
@@ -233,8 +233,8 @@ SYSCALL_DEFINE2(setns, int, fd, int, nstype)
 
 	err = -EINVAL;
 	ei = get_proc_ns(file_inode(file));
-	ops = ei->ns_ops;
-	if (nstype && (ops->type != nstype))
+	ns = ei->ns;
+	if (nstype && (ns->ops->type != nstype))
 		goto out;
 
 	new_nsproxy = create_new_namespaces(0, tsk, current_user_ns(), tsk->fs);
@@ -243,7 +243,7 @@ SYSCALL_DEFINE2(setns, int, fd, int, nstype)
 		goto out;
 	}
 
-	err = ops->install(new_nsproxy, ei->ns);
+	err = ns->ops->install(new_nsproxy, ns);
 	if (err) {
 		free_nsproxy(new_nsproxy);
 		goto out;

kernel/pid.c

@@ -80,6 +80,9 @@ struct pid_namespace init_pid_ns = {
 	.child_reaper = &init_task,
 	.user_ns = &init_user_ns,
 	.ns.inum = PROC_PID_INIT_INO,
+#ifdef CONFIG_PID_NS
+	.ns.ops = &pidns_operations,
+#endif
 };
 EXPORT_SYMBOL_GPL(init_pid_ns);
 

kernel/pid_namespace.c

@@ -108,6 +108,7 @@ static struct pid_namespace *create_pid_namespace(struct user_namespace *user_ns
 	err = ns_alloc_inum(&ns->ns);
 	if (err)
 		goto out_free_map;
+	ns->ns.ops = &pidns_operations;
 
 	kref_init(&ns->kref);
 	ns->level = level;

kernel/user.c

@@ -51,6 +51,9 @@ struct user_namespace init_user_ns = {
 	.owner = GLOBAL_ROOT_UID,
 	.group = GLOBAL_ROOT_GID,
 	.ns.inum = PROC_USER_INIT_INO,
+#ifdef CONFIG_USER_NS
+	.ns.ops = &userns_operations,
+#endif
 #ifdef CONFIG_PERSISTENT_KEYRINGS
 	.persistent_keyring_register_sem =
 	__RWSEM_INITIALIZER(init_user_ns.persistent_keyring_register_sem),

kernel/user_namespace.c

@@ -91,6 +91,7 @@ int create_user_ns(struct cred *new)
 		kmem_cache_free(user_ns_cachep, ns);
 		return ret;
 	}
+	ns->ns.ops = &userns_operations;
 
 	atomic_set(&ns->count, 1);
 	/* Leave the new->user_ns reference with the new user namespace. */

kernel/utsname.c

@@ -48,6 +48,8 @@ static struct uts_namespace *clone_uts_ns(struct user_namespace *user_ns,
 		return ERR_PTR(err);
 	}
 
+	ns->ns.ops = &utsns_operations;
+
 	down_read(&uts_sem);
 	memcpy(&ns->name, &old_ns->name, sizeof(ns->name));
 	ns->user_ns = get_user_ns(user_ns);

net/core/net_namespace.c

@@ -339,6 +339,7 @@ struct net *get_net_ns_by_fd(int fd)
 {
 	struct proc_ns *ei;
 	struct file *file;
+	struct ns_common *ns;
 	struct net *net;
 
 	file = proc_ns_fget(fd);
@@ -346,8 +347,9 @@ struct net *get_net_ns_by_fd(int fd)
 		return ERR_CAST(file);
 
 	ei = get_proc_ns(file_inode(file));
-	if (ei->ns_ops == &netns_operations)
-		net = get_net(container_of(ei->ns, struct net, ns));
+	ns = ei->ns;
+	if (ns->ops == &netns_operations)
+		net = get_net(container_of(ns, struct net, ns));
 	else
 		net = ERR_PTR(-EINVAL);
 
@@ -386,6 +388,9 @@ EXPORT_SYMBOL_GPL(get_net_ns_by_pid);
 
 static __net_init int net_ns_net_init(struct net *net)
 {
+#ifdef CONFIG_NET_NS
+	net->ns.ops = &netns_operations;
+#endif
 	return ns_alloc_inum(&net->ns);
 }