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

arch/ia64/kernel/perfmon.c

@@ -2145,22 +2145,12 @@ pfm_close(struct inode *inode, struct file *filp)
 	return 0;
 }
 
-static int
-pfm_no_open(struct inode *irrelevant, struct file *dontcare)
-{
-	DPRINT(("pfm_no_open called\n"));
-	return -ENXIO;
-}
-
-
-
 static const struct file_operations pfm_file_ops = {
 	.llseek		= no_llseek,
 	.read		= pfm_read,
 	.write		= pfm_write,
 	.poll		= pfm_poll,
 	.unlocked_ioctl = pfm_ioctl,
-	.open		= pfm_no_open,	/* special open code to disallow open via /proc */
 	.fasync		= pfm_fasync,
 	.release	= pfm_close,
 	.flush		= pfm_flush

fs/Makefile

@@ -11,7 +11,7 @@ obj-y :=	open.o read_write.o file_table.o super.o \
 		attr.o bad_inode.o file.o filesystems.o namespace.o \
 		seq_file.o xattr.o libfs.o fs-writeback.o \
 		pnode.o splice.o sync.o utimes.o \
-		stack.o fs_struct.o statfs.o fs_pin.o
+		stack.o fs_struct.o statfs.o fs_pin.o nsfs.o
 
 ifeq ($(CONFIG_BLOCK),y)
 obj-y +=	buffer.o block_dev.o direct-io.o mpage.o

fs/coda/dir.c

@@ -426,7 +426,6 @@ static int coda_venus_readdir(struct file *coda_file, struct dir_context *ctx)
 	struct coda_file_info *cfi;
 	struct coda_inode_info *cii;
 	struct file *host_file;
-	struct dentry *de;
 	struct venus_dirent *vdir;
 	unsigned long vdir_size = offsetof(struct venus_dirent, d_name);
 	unsigned int type;
@@ -438,8 +437,7 @@ static int coda_venus_readdir(struct file *coda_file, struct dir_context *ctx)
 	BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
 	host_file = cfi->cfi_container;
 
-	de = coda_file->f_path.dentry;
-	cii = ITOC(de->d_inode);
+	cii = ITOC(file_inode(coda_file));
 
 	vdir = kmalloc(sizeof(*vdir), GFP_KERNEL);
 	if (!vdir) return -ENOMEM;

fs/inode.c

@@ -114,6 +114,11 @@ int proc_nr_inodes(struct ctl_table *table, int write,
 }
 #endif
 
+static int no_open(struct inode *inode, struct file *file)
+{
+	return -ENXIO;
+}
+
 /**
  * inode_init_always - perform inode structure intialisation
  * @sb: superblock inode belongs to
@@ -125,15 +130,15 @@ int proc_nr_inodes(struct ctl_table *table, int write,
 int inode_init_always(struct super_block *sb, struct inode *inode)
 {
 	static const struct inode_operations empty_iops;
-	static const struct file_operations empty_fops;
+	static const struct file_operations no_open_fops = {.open = no_open};
 	struct address_space *const mapping = &inode->i_data;
 
 	inode->i_sb = sb;
 	inode->i_blkbits = sb->s_blocksize_bits;
 	inode->i_flags = 0;
 	atomic_set(&inode->i_count, 1);
 	inode->i_op = &empty_iops;
-	inode->i_fop = &empty_fops;
+	inode->i_fop = &no_open_fops;
 	inode->__i_nlink = 1;
 	inode->i_opflags = 0;
 	i_uid_write(inode, 0);
@@ -1798,7 +1803,7 @@ void init_special_inode(struct inode *inode, umode_t mode, dev_t rdev)
 	} else if (S_ISFIFO(mode))
 		inode->i_fop = &pipefifo_fops;
 	else if (S_ISSOCK(mode))
-		inode->i_fop = &bad_sock_fops;
+		;	/* leave it no_open_fops */
 	else
 		printk(KERN_DEBUG "init_special_inode: bogus i_mode (%o) for"
 				  " inode %s:%lu\n", mode, inode->i_sb->s_id,

fs/internal.h

@@ -147,3 +147,8 @@ extern const struct file_operations pipefifo_fops;
  */
 extern void sb_pin_kill(struct super_block *sb);
 extern void mnt_pin_kill(struct mount *m);
+
+/*
+ * fs/nsfs.c
+ */
+extern struct dentry_operations ns_dentry_operations;

fs/mount.h

@@ -1,10 +1,11 @@
 #include <linux/mount.h>
 #include <linux/seq_file.h>
 #include <linux/poll.h>
+#include <linux/ns_common.h>
 
 struct mnt_namespace {
 	atomic_t		count;
-	unsigned int		proc_inum;
+	struct ns_common	ns;
 	struct mount *	root;
 	struct list_head	list;
 	struct user_namespace	*user_ns;

fs/namei.c

@@ -487,6 +487,19 @@ void path_put(const struct path *path)
 }
 EXPORT_SYMBOL(path_put);
 
+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;
+	struct file	*base;
+	char *saved_names[MAX_NESTED_LINKS + 1];
+};
+
 /*
  * Path walking has 2 modes, rcu-walk and ref-walk (see
  * Documentation/filesystems/path-lookup.txt).  In situations when we can't
@@ -695,6 +708,18 @@ void nd_jump_link(struct nameidata *nd, struct path *path)
 	nd->flags |= LOOKUP_JUMPED;
 }
 
+void nd_set_link(struct nameidata *nd, char *path)
+{
+	nd->saved_names[nd->depth] = path;
+}
+EXPORT_SYMBOL(nd_set_link);
+
+char *nd_get_link(struct nameidata *nd)
+{
+	return nd->saved_names[nd->depth];
+}
+EXPORT_SYMBOL(nd_get_link);
+
 static inline void put_link(struct nameidata *nd, struct path *link, void *cookie)
 {
 	struct inode *inode = link->dentry->d_inode;
@@ -1821,13 +1846,14 @@ static int link_path_walk(const char *name, struct nameidata *nd)
 }
 
 static int path_init(int dfd, const char *name, unsigned int flags,
-		     struct nameidata *nd, struct file **fp)
+		     struct nameidata *nd)
 {
 	int retval = 0;
 
 	nd->last_type = LAST_ROOT; /* if there are only slashes... */
-	nd->flags = flags | LOOKUP_JUMPED;
+	nd->flags = flags | LOOKUP_JUMPED | LOOKUP_PARENT;
 	nd->depth = 0;
+	nd->base = NULL;
 	if (flags & LOOKUP_ROOT) {
 		struct dentry *root = nd->root.dentry;
 		struct inode *inode = root->d_inode;
@@ -1847,7 +1873,7 @@ static int path_init(int dfd, const char *name, unsigned int flags,
 		} else {
 			path_get(&nd->path);
 		}
-		return 0;
+		goto done;
 	}
 
 	nd->root.mnt = NULL;
@@ -1897,7 +1923,7 @@ static int path_init(int dfd, const char *name, unsigned int flags,
 		nd->path = f.file->f_path;
 		if (flags & LOOKUP_RCU) {
 			if (f.flags & FDPUT_FPUT)
-				*fp = f.file;
+				nd->base = f.file;
 			nd->seq = __read_seqcount_begin(&nd->path.dentry->d_seq);
 			rcu_read_lock();
 		} else {
@@ -1908,13 +1934,26 @@ static int path_init(int dfd, const char *name, unsigned int flags,
 
 	nd->inode = nd->path.dentry->d_inode;
 	if (!(flags & LOOKUP_RCU))
-		return 0;
+		goto done;
 	if (likely(!read_seqcount_retry(&nd->path.dentry->d_seq, nd->seq)))
-		return 0;
+		goto done;
 	if (!(nd->flags & LOOKUP_ROOT))
 		nd->root.mnt = NULL;
 	rcu_read_unlock();
 	return -ECHILD;
+done:
+	current->total_link_count = 0;
+	return link_path_walk(name, nd);
+}
+
+static void path_cleanup(struct nameidata *nd)
+{
+	if (nd->root.mnt && !(nd->flags & LOOKUP_ROOT)) {
+		path_put(&nd->root);
+		nd->root.mnt = NULL;
+	}
+	if (unlikely(nd->base))
+		fput(nd->base);
 }
 
 static inline int lookup_last(struct nameidata *nd, struct path *path)
@@ -1930,7 +1969,6 @@ static inline int lookup_last(struct nameidata *nd, struct path *path)
 static int path_lookupat(int dfd, const char *name,
 				unsigned int flags, struct nameidata *nd)
 {
-	struct file *base = NULL;
 	struct path path;
 	int err;
 
@@ -1948,14 +1986,7 @@ static int path_lookupat(int dfd, const char *name,
 	 * be handled by restarting a traditional ref-walk (which will always
 	 * be able to complete).
 	 */
-	err = path_init(dfd, name, flags | LOOKUP_PARENT, nd, &base);
-
-	if (unlikely(err))
-		goto out;
-
-	current->total_link_count = 0;
-	err = link_path_walk(name, nd);
-
+	err = path_init(dfd, name, flags, nd);
 	if (!err && !(flags & LOOKUP_PARENT)) {
 		err = lookup_last(nd, &path);
 		while (err > 0) {
@@ -1983,14 +2014,7 @@ static int path_lookupat(int dfd, const char *name,
 		}
 	}
 
-out:
-	if (base)
-		fput(base);
-
-	if (nd->root.mnt && !(nd->flags & LOOKUP_ROOT)) {
-		path_put(&nd->root);
-		nd->root.mnt = NULL;
-	}
+	path_cleanup(nd);
 	return err;
 }
 
@@ -2297,19 +2321,13 @@ mountpoint_last(struct nameidata *nd, struct path *path)
 static int
 path_mountpoint(int dfd, const char *name, struct path *path, unsigned int flags)
 {
-	struct file *base = NULL;
 	struct nameidata nd;
 	int err;
 
-	err = path_init(dfd, name, flags | LOOKUP_PARENT, &nd, &base);
+	err = path_init(dfd, name, flags, &nd);
 	if (unlikely(err))
 		goto out;
 
-	current->total_link_count = 0;
-	err = link_path_walk(name, &nd);
-	if (err)
-		goto out;
-
 	err = mountpoint_last(&nd, path);
 	while (err > 0) {
 		void *cookie;
@@ -2325,12 +2343,7 @@ path_mountpoint(int dfd, const char *name, struct path *path, unsigned int flags
 		put_link(&nd, &link, cookie);
 	}
 out:
-	if (base)
-		fput(base);
-
-	if (nd.root.mnt && !(nd.flags & LOOKUP_ROOT))
-		path_put(&nd.root);
-
+	path_cleanup(&nd);
 	return err;
 }
 
@@ -3181,7 +3194,6 @@ static int do_tmpfile(int dfd, struct filename *pathname,
 static struct file *path_openat(int dfd, struct filename *pathname,
 		struct nameidata *nd, const struct open_flags *op, int flags)
 {
-	struct file *base = NULL;
 	struct file *file;
 	struct path path;
 	int opened = 0;
@@ -3198,12 +3210,7 @@ static struct file *path_openat(int dfd, struct filename *pathname,
 		goto out;
 	}
 
-	error = path_init(dfd, pathname->name, flags | LOOKUP_PARENT, nd, &base);
-	if (unlikely(error))
-		goto out;
-
-	current->total_link_count = 0;
-	error = link_path_walk(pathname->name, nd);
+	error = path_init(dfd, pathname->name, flags, nd);
 	if (unlikely(error))
 		goto out;
 
@@ -3229,10 +3236,7 @@ static struct file *path_openat(int dfd, struct filename *pathname,
 		put_link(nd, &link, cookie);
 	}
 out:
-	if (nd->root.mnt && !(nd->flags & LOOKUP_ROOT))
-		path_put(&nd->root);
-	if (base)
-		fput(base);
+	path_cleanup(nd);
 	if (!(opened & FILE_OPENED)) {
 		BUG_ON(!error);
 		put_filp(file);