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

include/linux/fs.h

@@ -2176,7 +2176,6 @@ static inline int sb_is_blkdev_sb(struct super_block *sb)
 extern int sync_filesystem(struct super_block *);
 extern const struct file_operations def_blk_fops;
 extern const struct file_operations def_chr_fops;
-extern const struct file_operations bad_sock_fops;
 #ifdef CONFIG_BLOCK
 extern int ioctl_by_bdev(struct block_device *, unsigned, unsigned long);
 extern int blkdev_ioctl(struct block_device *, fmode_t, unsigned, unsigned long);

include/linux/ipc_namespace.h

@@ -6,6 +6,7 @@
 #include <linux/rwsem.h>
 #include <linux/notifier.h>
 #include <linux/nsproxy.h>
+#include <linux/ns_common.h>
 
 struct user_namespace;
 
@@ -58,7 +59,7 @@ struct ipc_namespace {
 	/* user_ns which owns the ipc ns */
 	struct user_namespace *user_ns;
 
-	unsigned int	proc_inum;
+	struct ns_common ns;
 };
 
 extern struct ipc_namespace init_ipc_ns;

include/linux/namei.h

@@ -7,21 +7,10 @@
 #include <linux/path.h>
 
 struct vfsmount;
+struct nameidata;
 
 enum { MAX_NESTED_LINKS = 8 };
 
-struct nameidata {
-	struct path	path;
-	struct qstr	last;
-	struct path	root;
-	struct inode	*inode; /* path.dentry.d_inode */
-	unsigned int	flags;
-	unsigned	seq, m_seq;
-	int		last_type;
-	unsigned	depth;
-	char *saved_names[MAX_NESTED_LINKS + 1];
-};
-
 /*
  * Type of the last component on LOOKUP_PARENT
  */
@@ -82,16 +71,8 @@ extern struct dentry *lock_rename(struct dentry *, struct dentry *);
 extern void unlock_rename(struct dentry *, struct dentry *);
 
 extern void nd_jump_link(struct nameidata *nd, struct path *path);
-
-static inline void nd_set_link(struct nameidata *nd, char *path)
-{
-	nd->saved_names[nd->depth] = path;
-}
-
-static inline char *nd_get_link(struct nameidata *nd)
-{
-	return nd->saved_names[nd->depth];
-}
+extern void nd_set_link(struct nameidata *nd, char *path);
+extern char *nd_get_link(struct nameidata *nd);
 
 static inline void nd_terminate_link(void *name, size_t len, size_t maxlen)
 {

include/linux/ns_common.h

@@ -0,0 +1,12 @@
+#ifndef _LINUX_NS_COMMON_H
+#define _LINUX_NS_COMMON_H
+
+struct proc_ns_operations;
+
+struct ns_common {
+	atomic_long_t stashed;
+	const struct proc_ns_operations *ops;
+	unsigned int inum;
+};
+
+#endif

include/linux/pid_namespace.h

@@ -8,6 +8,7 @@
 #include <linux/threads.h>
 #include <linux/nsproxy.h>
 #include <linux/kref.h>
+#include <linux/ns_common.h>
 
 struct pidmap {
        atomic_t nr_free;
@@ -43,7 +44,7 @@ struct pid_namespace {
 	kgid_t pid_gid;
 	int hide_pid;
 	int reboot;	/* group exit code if this pidns was rebooted */
-	unsigned int proc_inum;
+	struct ns_common ns;
 };
 
 extern struct pid_namespace init_pid_ns;

include/linux/proc_ns.h

@@ -4,21 +4,18 @@
 #ifndef _LINUX_PROC_NS_H
 #define _LINUX_PROC_NS_H
 
+#include <linux/ns_common.h>
+
 struct pid_namespace;
 struct nsproxy;
+struct path;
 
 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 proc_ns {
-	void *ns;
-	const struct proc_ns_operations *ns_ops;
+	struct ns_common *(*get)(struct task_struct *task);
+	void (*put)(struct ns_common *ns);
+	int (*install)(struct nsproxy *nsproxy, struct ns_common *ns);
 };
 
 extern const struct proc_ns_operations netns_operations;
@@ -43,32 +40,38 @@ enum {
 
 extern int pid_ns_prepare_proc(struct pid_namespace *ns);
 extern void pid_ns_release_proc(struct pid_namespace *ns);
-extern struct file *proc_ns_fget(int fd);
-extern struct proc_ns *get_proc_ns(struct inode *);
 extern int proc_alloc_inum(unsigned int *pino);
 extern void proc_free_inum(unsigned int inum);
-extern bool proc_ns_inode(struct inode *inode);
 
 #else /* CONFIG_PROC_FS */
 
 static inline int pid_ns_prepare_proc(struct pid_namespace *ns) { return 0; }
 static inline void pid_ns_release_proc(struct pid_namespace *ns) {}
 
-static inline struct file *proc_ns_fget(int fd)
-{
-	return ERR_PTR(-EINVAL);
-}
-
-static inline struct proc_ns *get_proc_ns(struct inode *inode) { return NULL; }
-
 static inline int proc_alloc_inum(unsigned int *inum)
 {
 	*inum = 1;
 	return 0;
 }
 static inline void proc_free_inum(unsigned int inum) {}
-static inline bool proc_ns_inode(struct inode *inode) { return false; }
 
 #endif /* CONFIG_PROC_FS */
 
+static inline int ns_alloc_inum(struct ns_common *ns)
+{
+	atomic_long_set(&ns->stashed, 0);
+	return proc_alloc_inum(&ns->inum);
+}
+
+#define ns_free_inum(ns) proc_free_inum((ns)->inum)
+
+extern struct file *proc_ns_fget(int fd);
+#define get_proc_ns(inode) ((struct ns_common *)(inode)->i_private)
+extern void *ns_get_path(struct path *path, struct task_struct *task,
+			const struct proc_ns_operations *ns_ops);
+
+extern int ns_get_name(char *buf, size_t size, struct task_struct *task,
+			const struct proc_ns_operations *ns_ops);
+extern void nsfs_init(void);
+
 #endif /* _LINUX_PROC_NS_H */

include/linux/user_namespace.h

@@ -3,6 +3,7 @@
 
 #include <linux/kref.h>
 #include <linux/nsproxy.h>
+#include <linux/ns_common.h>
 #include <linux/sched.h>
 #include <linux/err.h>
 
@@ -26,7 +27,7 @@ struct user_namespace {
 	int			level;
 	kuid_t			owner;
 	kgid_t			group;
-	unsigned int		proc_inum;
+	struct ns_common	ns;
 
 	/* Register of per-UID persistent keyrings for this namespace */
 #ifdef CONFIG_PERSISTENT_KEYRINGS

include/linux/utsname.h

@@ -5,6 +5,7 @@
 #include <linux/sched.h>
 #include <linux/kref.h>
 #include <linux/nsproxy.h>
+#include <linux/ns_common.h>
 #include <linux/err.h>
 #include <uapi/linux/utsname.h>
 
@@ -23,7 +24,7 @@ struct uts_namespace {
 	struct kref kref;
 	struct new_utsname name;
 	struct user_namespace *user_ns;
-	unsigned int proc_inum;
+	struct ns_common ns;
 };
 extern struct uts_namespace init_uts_ns;
 

include/net/net_namespace.h

@@ -26,6 +26,7 @@
 #endif
 #include <net/netns/nftables.h>
 #include <net/netns/xfrm.h>
+#include <linux/ns_common.h>
 
 struct user_namespace;
 struct proc_dir_entry;
@@ -60,7 +61,7 @@ struct net {
 
 	struct user_namespace   *user_ns;	/* Owning user namespace */
 
-	unsigned int		proc_inum;
+	struct ns_common	ns;
 
 	struct proc_dir_entry 	*proc_net;
 	struct proc_dir_entry 	*proc_net_stat;

include/uapi/linux/magic.h

@@ -72,5 +72,6 @@
 #define MTD_INODE_FS_MAGIC      0x11307854
 #define ANON_INODE_FS_MAGIC	0x09041934
 #define BTRFS_TEST_MAGIC	0x73727279
+#define NSFS_MAGIC		0x6e736673
 
 #endif /* __LINUX_MAGIC_H__ */