make proc_ns_operations work with struct ns_common * instead of void *

We can do that now.  And kill ->inum(), while we are at it - all instances
are identical.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/namespace.c

@@ -3149,7 +3149,7 @@ bool fs_fully_visible(struct file_system_type *type)
 	return visible;
 }
 
-static void *mntns_get(struct task_struct *task)
+static struct ns_common *mntns_get(struct task_struct *task)
 {
 	struct ns_common *ns = NULL;
 	struct nsproxy *nsproxy;
@@ -3165,12 +3165,12 @@ static void *mntns_get(struct task_struct *task)
 	return ns;
 }
 
-static void mntns_put(void *ns)
+static void mntns_put(struct ns_common *ns)
 {
 	put_mnt_ns(to_mnt_ns(ns));
 }
 
-static int mntns_install(struct nsproxy *nsproxy, void *ns)
+static int mntns_install(struct nsproxy *nsproxy, struct ns_common *ns)
 {
 	struct fs_struct *fs = current->fs;
 	struct mnt_namespace *mnt_ns = to_mnt_ns(ns);
@@ -3203,17 +3203,10 @@ static int mntns_install(struct nsproxy *nsproxy, void *ns)
 	return 0;
 }
 
-static unsigned int mntns_inum(void *ns)
-{
-	struct ns_common *p = ns;
-	return p->inum;
-}
-
 const struct proc_ns_operations mntns_operations = {
 	.name		= "mnt",
 	.type		= CLONE_NEWNS,
 	.get		= mntns_get,
 	.put		= mntns_put,
 	.install	= mntns_install,
-	.inum		= mntns_inum,
 };

fs/proc/inode.c

@@ -33,7 +33,7 @@ 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;
-	void *ns;
+	struct ns_common *ns;
 
 	truncate_inode_pages_final(&inode->i_data);
 	clear_inode(inode);

fs/proc/namespaces.c

@@ -64,7 +64,7 @@ static struct dentry *proc_ns_get_dentry(struct super_block *sb,
 	struct inode *inode;
 	struct proc_inode *ei;
 	struct qstr qname = { .name = "", };
-	void *ns;
+	struct ns_common *ns;
 
 	ns = ns_ops->get(task);
 	if (!ns)
@@ -76,7 +76,7 @@ static struct dentry *proc_ns_get_dentry(struct super_block *sb,
 		return ERR_PTR(-ENOMEM);
 	}
 
-	inode = iget_locked(sb, ns_ops->inum(ns));
+	inode = iget_locked(sb, ns->inum);
 	if (!inode) {
 		dput(dentry);
 		ns_ops->put(ns);
@@ -144,7 +144,7 @@ static int proc_ns_readlink(struct dentry *dentry, char __user *buffer, int bufl
 	struct proc_inode *ei = PROC_I(inode);
 	const struct proc_ns_operations *ns_ops = ei->ns.ns_ops;
 	struct task_struct *task;
-	void *ns;
+	struct ns_common *ns;
 	char name[50];
 	int res = -EACCES;
 
@@ -160,7 +160,7 @@ static int proc_ns_readlink(struct dentry *dentry, char __user *buffer, int bufl
 	if (!ns)
 		goto out_put_task;
 
-	snprintf(name, sizeof(name), "%s:[%u]", ns_ops->name, ns_ops->inum(ns));
+	snprintf(name, sizeof(name), "%s:[%u]", ns_ops->name, ns->inum);
 	res = readlink_copy(buffer, buflen, name);
 	ns_ops->put(ns);
 out_put_task:

include/linux/proc_ns.h

@@ -6,18 +6,18 @@
 
 struct pid_namespace;
 struct nsproxy;
+struct ns_common;
 
 struct proc_ns_operations {
 	const char *name;
 	int type;
-	void *(*get)(struct task_struct *task);
-	void (*put)(void *ns);
-	int (*install)(struct nsproxy *nsproxy, void *ns);
-	unsigned int (*inum)(void *ns);
+	struct ns_common *(*get)(struct task_struct *task);
+	void (*put)(struct ns_common *ns);
+	int (*install)(struct nsproxy *nsproxy, struct ns_common *ns);
 };
 
 struct proc_ns {
-	void *ns;
+	struct ns_common *ns;
 	const struct proc_ns_operations *ns_ops;
 };
 

ipc/namespace.c

@@ -154,7 +154,7 @@ static inline struct ipc_namespace *to_ipc_ns(struct ns_common *ns)
 	return container_of(ns, struct ipc_namespace, ns);
 }
 
-static void *ipcns_get(struct task_struct *task)
+static struct ns_common *ipcns_get(struct task_struct *task)
 {
 	struct ipc_namespace *ns = NULL;
 	struct nsproxy *nsproxy;
@@ -168,12 +168,12 @@ static void *ipcns_get(struct task_struct *task)
 	return ns ? &ns->ns : NULL;
 }
 
-static void ipcns_put(void *ns)
+static void ipcns_put(struct ns_common *ns)
 {
 	return put_ipc_ns(to_ipc_ns(ns));
 }
 
-static int ipcns_install(struct nsproxy *nsproxy, void *new)
+static int ipcns_install(struct nsproxy *nsproxy, struct ns_common *new)
 {
 	struct ipc_namespace *ns = to_ipc_ns(new);
 	if (!ns_capable(ns->user_ns, CAP_SYS_ADMIN) ||
@@ -187,16 +187,10 @@ static int ipcns_install(struct nsproxy *nsproxy, void *new)
 	return 0;
 }
 
-static unsigned int ipcns_inum(void *vp)
-{
-	return ((struct ns_common *)vp)->inum;
-}
-
 const struct proc_ns_operations ipcns_operations = {
 	.name		= "ipc",
 	.type		= CLONE_NEWIPC,
 	.get		= ipcns_get,
 	.put		= ipcns_put,
 	.install	= ipcns_install,
-	.inum		= ipcns_inum,
 };

kernel/pid_namespace.c

@@ -318,7 +318,7 @@ static inline struct pid_namespace *to_pid_ns(struct ns_common *ns)
 	return container_of(ns, struct pid_namespace, ns);
 }
 
-static void *pidns_get(struct task_struct *task)
+static struct ns_common *pidns_get(struct task_struct *task)
 {
 	struct pid_namespace *ns;
 
@@ -331,12 +331,12 @@ static void *pidns_get(struct task_struct *task)
 	return ns ? &ns->ns : NULL;
 }
 
-static void pidns_put(void *ns)
+static void pidns_put(struct ns_common *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 = to_pid_ns(ns);
@@ -367,18 +367,12 @@ static int pidns_install(struct nsproxy *nsproxy, void *ns)
 	return 0;
 }
 
-static unsigned int pidns_inum(void *ns)
-{
-	return ((struct ns_common *)ns)->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_namespace.c

@@ -846,7 +846,7 @@ static inline struct user_namespace *to_user_ns(struct ns_common *ns)
 	return container_of(ns, struct user_namespace, ns);
 }
 
-static void *userns_get(struct task_struct *task)
+static struct ns_common *userns_get(struct task_struct *task)
 {
 	struct user_namespace *user_ns;
 
@@ -857,12 +857,12 @@ static void *userns_get(struct task_struct *task)
 	return user_ns ? &user_ns->ns : NULL;
 }
 
-static void userns_put(void *ns)
+static void userns_put(struct ns_common *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 = to_user_ns(ns);
 	struct cred *cred;
@@ -893,18 +893,12 @@ static int userns_install(struct nsproxy *nsproxy, void *ns)
 	return commit_creds(cred);
 }
 
-static unsigned int userns_inum(void *ns)
-{
-	return ((struct ns_common *)ns)->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

@@ -93,7 +93,7 @@ static inline struct uts_namespace *to_uts_ns(struct ns_common *ns)
 	return container_of(ns, struct uts_namespace, ns);
 }
 
-static void *utsns_get(struct task_struct *task)
+static struct ns_common *utsns_get(struct task_struct *task)
 {
 	struct uts_namespace *ns = NULL;
 	struct nsproxy *nsproxy;
@@ -109,12 +109,12 @@ static void *utsns_get(struct task_struct *task)
 	return ns ? &ns->ns : NULL;
 }
 
-static void utsns_put(void *ns)
+static void utsns_put(struct ns_common *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 = to_uts_ns(new);
 
@@ -128,16 +128,10 @@ static int utsns_install(struct nsproxy *nsproxy, void *new)
 	return 0;
 }
 
-static unsigned int utsns_inum(void *vp)
-{
-	return ((struct ns_common *)vp)->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,
 };

net/core/net_namespace.c

@@ -629,7 +629,7 @@ void unregister_pernet_device(struct pernet_operations *ops)
 EXPORT_SYMBOL_GPL(unregister_pernet_device);
 
 #ifdef CONFIG_NET_NS
-static void *netns_get(struct task_struct *task)
+static struct ns_common *netns_get(struct task_struct *task)
 {
 	struct net *net = NULL;
 	struct nsproxy *nsproxy;
@@ -648,12 +648,12 @@ static inline struct net *to_net_ns(struct ns_common *ns)
 	return container_of(ns, struct net, ns);
 }
 
-static void netns_put(void *ns)
+static void netns_put(struct ns_common *ns)
 {
 	put_net(to_net_ns(ns));
 }
 
-static int netns_install(struct nsproxy *nsproxy, void *ns)
+static int netns_install(struct nsproxy *nsproxy, struct ns_common *ns)
 {
 	struct net *net = to_net_ns(ns);
 
@@ -666,17 +666,11 @@ static int netns_install(struct nsproxy *nsproxy, void *ns)
 	return 0;
 }
 
-static unsigned int netns_inum(void *ns)
-{
-	return ((struct ns_common *)ns)->inum;
-}
-
 const struct proc_ns_operations netns_operations = {
 	.name		= "net",
 	.type		= CLONE_NEWNET,
 	.get		= netns_get,
 	.put		= netns_put,
 	.install	= netns_install,
-	.inum		= netns_inum,
 };
 #endif