ns: add ns_common_free()

And drop ns_free_inum(). Anything common that can be wasted centrally
should be wasted in the new common helper.

Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>

Author: brauner

fs/namespace.c

@@ -4082,7 +4082,7 @@ static void dec_mnt_namespaces(struct ucounts *ucounts)
 static void free_mnt_ns(struct mnt_namespace *ns)
 {
 	if (!is_anon_ns(ns))
-		ns_free_inum(&ns->ns);
+		ns_common_free(ns);
 	dec_mnt_namespaces(ns->ucounts);
 	mnt_ns_tree_remove(ns);
 }
@@ -4154,7 +4154,7 @@ struct mnt_namespace *copy_mnt_ns(unsigned long flags, struct mnt_namespace *ns,
 	new = copy_tree(old, old->mnt.mnt_root, copy_flags);
 	if (IS_ERR(new)) {
 		namespace_unlock();
-		ns_free_inum(&new_ns->ns);
+		ns_common_free(ns);
 		dec_mnt_namespaces(new_ns->ucounts);
 		mnt_ns_release(new_ns);
 		return ERR_CAST(new);

include/linux/ns_common.h

@@ -41,6 +41,7 @@ struct ns_common {
 };
 
 int __ns_common_init(struct ns_common *ns, const struct proc_ns_operations *ops, int inum);
+void __ns_common_free(struct ns_common *ns);
 
 #define to_ns_common(__ns)                              \
 	_Generic((__ns),                                \
@@ -80,4 +81,6 @@ int __ns_common_init(struct ns_common *ns, const struct proc_ns_operations *ops,
 
 #define ns_common_init_inum(__ns, __ops, __inum) __ns_common_init(to_ns_common(__ns), __ops, __inum)
 
+#define ns_common_free(__ns) __ns_common_free(to_ns_common((__ns)))
+
 #endif

include/linux/proc_ns.h

@@ -66,8 +66,6 @@ static inline void proc_free_inum(unsigned int inum) {}
 
 #endif /* CONFIG_PROC_FS */
 
-#define ns_free_inum(ns) proc_free_inum((ns)->inum)
-
 #define get_proc_ns(inode) ((struct ns_common *)(inode)->i_private)
 
 #endif /* _LINUX_PROC_NS_H */

ipc/namespace.c

@@ -97,7 +97,7 @@ static struct ipc_namespace *create_ipc_ns(struct user_namespace *user_ns,
 
 fail_put:
 	put_user_ns(ns->user_ns);
-	ns_free_inum(&ns->ns);
+	ns_common_free(ns);
 fail_free:
 	kfree(ns);
 fail_dec:
@@ -161,7 +161,7 @@ static void free_ipc_ns(struct ipc_namespace *ns)
 
 	dec_ipc_namespaces(ns->ucounts);
 	put_user_ns(ns->user_ns);
-	ns_free_inum(&ns->ns);
+	ns_common_free(ns);
 	kfree(ns);
 }
 

kernel/cgroup/namespace.c

@@ -40,7 +40,7 @@ void free_cgroup_ns(struct cgroup_namespace *ns)
 	put_css_set(ns->root_cset);
 	dec_cgroup_namespaces(ns->ucounts);
 	put_user_ns(ns->user_ns);
-	ns_free_inum(&ns->ns);
+	ns_common_free(ns);
 	/* Concurrent nstree traversal depends on a grace period. */
 	kfree_rcu(ns, ns.ns_rcu);
 }

kernel/nscommon.c

@@ -18,3 +18,8 @@ int __ns_common_init(struct ns_common *ns, const struct proc_ns_operations *ops,
 	}
 	return proc_alloc_inum(&ns->inum);
 }
+
+void __ns_common_free(struct ns_common *ns)
+{
+	proc_free_inum(ns->inum);
+}

kernel/pid_namespace.c

@@ -127,7 +127,7 @@ static struct pid_namespace *create_pid_namespace(struct user_namespace *user_ns
 	return ns;
 
 out_free_inum:
-	ns_free_inum(&ns->ns);
+	ns_common_free(ns);
 out_free_idr:
 	idr_destroy(&ns->idr);
 	kmem_cache_free(pid_ns_cachep, ns);
@@ -152,7 +152,7 @@ static void destroy_pid_namespace(struct pid_namespace *ns)
 	ns_tree_remove(ns);
 	unregister_pidns_sysctls(ns);
 
-	ns_free_inum(&ns->ns);
+	ns_common_free(ns);
 
 	idr_destroy(&ns->idr);
 	call_rcu(&ns->rcu, delayed_free_pidns);

kernel/time/namespace.c

@@ -255,7 +255,7 @@ void free_time_ns(struct time_namespace *ns)
 	ns_tree_remove(ns);
 	dec_time_namespaces(ns->ucounts);
 	put_user_ns(ns->user_ns);
-	ns_free_inum(&ns->ns);
+	ns_common_free(ns);
 	__free_page(ns->vvar_page);
 	/* Concurrent nstree traversal depends on a grace period. */
 	kfree_rcu(ns, ns.ns_rcu);

kernel/user_namespace.c

@@ -165,7 +165,7 @@ int create_user_ns(struct cred *new)
 #ifdef CONFIG_PERSISTENT_KEYRINGS
 	key_put(ns->persistent_keyring_register);
 #endif
-	ns_free_inum(&ns->ns);
+	ns_common_free(ns);
 fail_free:
 	kmem_cache_free(user_ns_cachep, ns);
 fail_dec:
@@ -220,7 +220,7 @@ static void free_user_ns(struct work_struct *work)
 #endif
 		retire_userns_sysctls(ns);
 		key_free_user_ns(ns);
-		ns_free_inum(&ns->ns);
+		ns_common_free(ns);
 		/* Concurrent nstree traversal depends on a grace period. */
 		kfree_rcu(ns, ns.ns_rcu);
 		dec_user_namespaces(ucounts);

kernel/utsname.c

@@ -98,7 +98,7 @@ void free_uts_ns(struct uts_namespace *ns)
 	ns_tree_remove(ns);
 	dec_uts_namespaces(ns->ucounts);
 	put_user_ns(ns->user_ns);
-	ns_free_inum(&ns->ns);
+	ns_common_free(ns);
 	/* Concurrent nstree traversal depends on a grace period. */
 	kfree_rcu(ns, ns.ns_rcu);
 }