Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs pile #2 from Al Viro:
 "Next pile (and there'll be one or two more).

  The large piece in this one is getting rid of /proc/*/ns/* weirdness;
  among other things, it allows to (finally) make nameidata completely
  opaque outside of fs/namei.c, making for easier further cleanups in
  there"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  coda_venus_readdir(): use file_inode()
  fs/namei.c: fold link_path_walk() call into path_init()
  path_init(): don't bother with LOOKUP_PARENT in argument
  fs/namei.c: new helper (path_cleanup())
  path_init(): store the "base" pointer to file in nameidata itself
  make default ->i_fop have ->open() fail with ENXIO
  make nameidata completely opaque outside of fs/namei.c
  kill proc_ns completely
  take the targets of /proc/*/ns/* symlinks to separate fs
  bury struct proc_ns in fs/proc
  copy address of proc_ns_ops into ns_common
  new helpers: ns_alloc_inum/ns_free_inum
  make proc_ns_operations work with struct ns_common * instead of void *
  switch the rest of proc_ns_operations to working with &...->ns
  netns: switch ->get()/->put()/->install()/->inum() to working with &net->ns
  make mntns ->get()/->put()/->install()/->inum() work with &mnt_ns->ns
  common object embedded into various struct ....ns

kernel/nsproxy.c

@@ -220,11 +220,10 @@ 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);
@@ -232,9 +231,8 @@ SYSCALL_DEFINE2(setns, int, fd, int, nstype)
 		return PTR_ERR(file);
 
 	err = -EINVAL;
-	ei = get_proc_ns(file_inode(file));
-	ops = ei->ns_ops;
-	if (nstype && (ops->type != nstype))
+	ns = get_proc_ns(file_inode(file));
+	if (nstype && (ns->ops->type != nstype))
 		goto out;
 
 	new_nsproxy = create_new_namespaces(0, tsk, current_user_ns(), tsk->fs);
@@ -243,7 +241,7 @@ 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

@@ -79,7 +79,10 @@ struct pid_namespace init_pid_ns = {
 	.level = 0,
 	.child_reaper = &init_task,
 	.user_ns = &init_user_ns,
-	.proc_inum = PROC_PID_INIT_INO,
+	.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

@@ -105,9 +105,10 @@ 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->proc_inum);
+	err = ns_alloc_inum(&ns->ns);
 	if (err)
 		goto out_free_map;
+	ns->ns.ops = &pidns_operations;
 
 	kref_init(&ns->kref);
 	ns->level = level;
@@ -142,7 +143,7 @@ static void destroy_pid_namespace(struct pid_namespace *ns)
 {
 	int i;
 
-	proc_free_inum(ns->proc_inum);
+	ns_free_inum(&ns->ns);
 	for (i = 0; i < PIDMAP_ENTRIES; i++)
 		kfree(ns->pidmap[i].page);
 	put_user_ns(ns->user_ns);
@@ -333,7 +334,12 @@ int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd)
 	return 0;
 }
 
-static void *pidns_get(struct task_struct *task)
+static inline struct pid_namespace *to_pid_ns(struct ns_common *ns)
+{
+	return container_of(ns, struct pid_namespace, ns);
+}
+
+static struct ns_common *pidns_get(struct task_struct *task)
 {
 	struct pid_namespace *ns;
 
@@ -343,18 +349,18 @@ static void *pidns_get(struct task_struct *task)
 		get_pid_ns(ns);
 	rcu_read_unlock();
 
-	return ns;
+	return ns ? &ns->ns : NULL;
 }
 
-static void pidns_put(void *ns)
+static void pidns_put(struct ns_common *ns)
 {
-	put_pid_ns(ns);
+	put_pid_ns(to_pid_ns(ns));
 }
 
-static int pidns_install(struct nsproxy *nsproxy, void *ns)
+static int pidns_install(struct nsproxy *nsproxy, struct ns_common *ns)
 {
 	struct pid_namespace *active = task_active_pid_ns(current);
-	struct pid_namespace *ancestor, *new = ns;
+	struct pid_namespace *ancestor, *new = to_pid_ns(ns);
 
 	if (!ns_capable(new->user_ns, CAP_SYS_ADMIN) ||
 	    !ns_capable(current_user_ns(), CAP_SYS_ADMIN))
@@ -382,19 +388,12 @@ static int pidns_install(struct nsproxy *nsproxy, void *ns)
 	return 0;
 }
 
-static unsigned int pidns_inum(void *ns)
-{
-	struct pid_namespace *pid_ns = ns;
-	return pid_ns->proc_inum;
-}
-
 const struct proc_ns_operations pidns_operations = {
 	.name		= "pid",
 	.type		= CLONE_NEWPID,
 	.get		= pidns_get,
 	.put		= pidns_put,
 	.install	= pidns_install,
-	.inum		= pidns_inum,
 };
 
 static __init int pid_namespaces_init(void)

kernel/user.c

@@ -50,7 +50,10 @@ struct user_namespace init_user_ns = {
 	.count = ATOMIC_INIT(3),
 	.owner = GLOBAL_ROOT_UID,
 	.group = GLOBAL_ROOT_GID,
-	.proc_inum = PROC_USER_INIT_INO,
+	.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

@@ -86,11 +86,12 @@ int create_user_ns(struct cred *new)
 	if (!ns)
 		return -ENOMEM;
 
-	ret = proc_alloc_inum(&ns->proc_inum);
+	ret = ns_alloc_inum(&ns->ns);
 	if (ret) {
 		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. */
@@ -136,7 +137,7 @@ void free_user_ns(struct user_namespace *ns)
 #ifdef CONFIG_PERSISTENT_KEYRINGS
 		key_put(ns->persistent_keyring_register);
 #endif
-		proc_free_inum(ns->proc_inum);
+		ns_free_inum(&ns->ns);
 		kmem_cache_free(user_ns_cachep, ns);
 		ns = parent;
 	} while (atomic_dec_and_test(&parent->count));
@@ -841,7 +842,12 @@ static bool new_idmap_permitted(const struct file *file,
 	return false;
 }
 
-static void *userns_get(struct task_struct *task)
+static inline struct user_namespace *to_user_ns(struct ns_common *ns)
+{
+	return container_of(ns, struct user_namespace, ns);
+}
+
+static struct ns_common *userns_get(struct task_struct *task)
 {
 	struct user_namespace *user_ns;
 
@@ -849,17 +855,17 @@ static void *userns_get(struct task_struct *task)
 	user_ns = get_user_ns(__task_cred(task)->user_ns);
 	rcu_read_unlock();
 
-	return user_ns;
+	return user_ns ? &user_ns->ns : NULL;
 }
 
-static void userns_put(void *ns)
+static void userns_put(struct ns_common *ns)
 {
-	put_user_ns(ns);
+	put_user_ns(to_user_ns(ns));
 }
 
-static int userns_install(struct nsproxy *nsproxy, void *ns)
+static int userns_install(struct nsproxy *nsproxy, struct ns_common *ns)
 {
-	struct user_namespace *user_ns = ns;
+	struct user_namespace *user_ns = to_user_ns(ns);
 	struct cred *cred;
 
 	/* Don't allow gaining capabilities by reentering
@@ -888,19 +894,12 @@ static int userns_install(struct nsproxy *nsproxy, void *ns)
 	return commit_creds(cred);
 }
 
-static unsigned int userns_inum(void *ns)
-{
-	struct user_namespace *user_ns = ns;
-	return user_ns->proc_inum;
-}
-
 const struct proc_ns_operations userns_operations = {
 	.name		= "user",
 	.type		= CLONE_NEWUSER,
 	.get		= userns_get,
 	.put		= userns_put,
 	.install	= userns_install,
-	.inum		= userns_inum,
 };
 
 static __init int user_namespaces_init(void)

kernel/utsname.c

@@ -42,12 +42,14 @@ static struct uts_namespace *clone_uts_ns(struct user_namespace *user_ns,
 	if (!ns)
 		return ERR_PTR(-ENOMEM);
 
-	err = proc_alloc_inum(&ns->proc_inum);
+	err = ns_alloc_inum(&ns->ns);
 	if (err) {
 		kfree(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);
@@ -84,11 +86,16 @@ 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->proc_inum);
+	ns_free_inum(&ns->ns);
 	kfree(ns);
 }
 
-static void *utsns_get(struct task_struct *task)
+static inline struct uts_namespace *to_uts_ns(struct ns_common *ns)
+{
+	return container_of(ns, struct uts_namespace, ns);
+}
+
+static struct ns_common *utsns_get(struct task_struct *task)
 {
 	struct uts_namespace *ns = NULL;
 	struct nsproxy *nsproxy;
@@ -101,17 +108,17 @@ static void *utsns_get(struct task_struct *task)
 	}
 	task_unlock(task);
 
-	return ns;
+	return ns ? &ns->ns : NULL;
 }
 
-static void utsns_put(void *ns)
+static void utsns_put(struct ns_common *ns)
 {
-	put_uts_ns(ns);
+	put_uts_ns(to_uts_ns(ns));
 }
 
-static int utsns_install(struct nsproxy *nsproxy, void *new)
+static int utsns_install(struct nsproxy *nsproxy, struct ns_common *new)
 {
-	struct uts_namespace *ns = new;
+	struct uts_namespace *ns = to_uts_ns(new);
 
 	if (!ns_capable(ns->user_ns, CAP_SYS_ADMIN) ||
 	    !ns_capable(current_user_ns(), CAP_SYS_ADMIN))
@@ -123,18 +130,10 @@ static int utsns_install(struct nsproxy *nsproxy, void *new)
 	return 0;
 }
 
-static unsigned int utsns_inum(void *vp)
-{
-	struct uts_namespace *ns = vp;
-
-	return ns->proc_inum;
-}
-
 const struct proc_ns_operations utsns_operations = {
 	.name		= "uts",
 	.type		= CLONE_NEWUTS,
 	.get		= utsns_get,
 	.put		= utsns_put,
 	.install	= utsns_install,
-	.inum		= utsns_inum,
 };