Moved, renamed, and deleted files

The original directory structure was scattered and unorganized.
Changes are basically to make it look like kernel structure.

1 files changed, 0 insertions, 2636 deletions

diff --git a/ANDROID_3.4.5/fs/namespace.c b/ANDROID_3.4.5/fs/namespace.c
deleted file mode 100644
index 4e465397..00000000
--- a/ANDROID_3.4.5/fs/namespace.c
+++ /dev/null
@@ -1,2636 +0,0 @@
-/*
- *  linux/fs/namespace.c
- *
- * (C) Copyright Al Viro 2000, 2001
- *	Released under GPL v2.
- *
- * Based on code from fs/super.c, copyright Linus Torvalds and others.
- * Heavily rewritten.
- */
-
-#include <linux/syscalls.h>
-#include <linux/export.h>
-#include <linux/capability.h>
-#include <linux/mnt_namespace.h>
-#include <linux/namei.h>
-#include <linux/security.h>
-#include <linux/idr.h>
-#include <linux/acct.h>		/* acct_auto_close_mnt */
-#include <linux/ramfs.h>	/* init_rootfs */
-#include <linux/fs_struct.h>	/* get_fs_root et.al. */
-#include <linux/fsnotify.h>	/* fsnotify_vfsmount_delete */
-#include <linux/uaccess.h>
-#include "pnode.h"
-#include "internal.h"
-
-#define HASH_SHIFT ilog2(PAGE_SIZE / sizeof(struct list_head))
-#define HASH_SIZE (1UL << HASH_SHIFT)
-
-static int event;
-static DEFINE_IDA(mnt_id_ida);
-static DEFINE_IDA(mnt_group_ida);
-static DEFINE_SPINLOCK(mnt_id_lock);
-static int mnt_id_start = 0;
-static int mnt_group_start = 1;
-
-static struct list_head *mount_hashtable __read_mostly;
-static struct kmem_cache *mnt_cache __read_mostly;
-static struct rw_semaphore namespace_sem;
-
-/* /sys/fs */
-struct kobject *fs_kobj;
-EXPORT_SYMBOL_GPL(fs_kobj);
-
-/*
- * vfsmount lock may be taken for read to prevent changes to the
- * vfsmount hash, ie. during mountpoint lookups or walking back
- * up the tree.
- *
- * It should be taken for write in all cases where the vfsmount
- * tree or hash is modified or when a vfsmount structure is modified.
- */
-DEFINE_BRLOCK(vfsmount_lock);
-
-static inline unsigned long hash(struct vfsmount *mnt, struct dentry *dentry)
-{
-	unsigned long tmp = ((unsigned long)mnt / L1_CACHE_BYTES);
-	tmp += ((unsigned long)dentry / L1_CACHE_BYTES);
-	tmp = tmp + (tmp >> HASH_SHIFT);
-	return tmp & (HASH_SIZE - 1);
-}
-
-#define MNT_WRITER_UNDERFLOW_LIMIT -(1<<16)
-
-/*
- * allocation is serialized by namespace_sem, but we need the spinlock to
- * serialize with freeing.
- */
-static int mnt_alloc_id(struct mount *mnt)
-{
-	int res;
-
-retry:
-	ida_pre_get(&mnt_id_ida, GFP_KERNEL);
-	spin_lock(&mnt_id_lock);
-	res = ida_get_new_above(&mnt_id_ida, mnt_id_start, &mnt->mnt_id);
-	if (!res)
-		mnt_id_start = mnt->mnt_id + 1;
-	spin_unlock(&mnt_id_lock);
-	if (res == -EAGAIN)
-		goto retry;
-
-	return res;
-}
-
-static void mnt_free_id(struct mount *mnt)
-{
-	int id = mnt->mnt_id;
-	spin_lock(&mnt_id_lock);
-	ida_remove(&mnt_id_ida, id);
-	if (mnt_id_start > id)
-		mnt_id_start = id;
-	spin_unlock(&mnt_id_lock);
-}
-
-/*
- * Allocate a new peer group ID
- *
- * mnt_group_ida is protected by namespace_sem
- */
-static int mnt_alloc_group_id(struct mount *mnt)
-{
-	int res;
-
-	if (!ida_pre_get(&mnt_group_ida, GFP_KERNEL))
-		return -ENOMEM;
-
-	res = ida_get_new_above(&mnt_group_ida,
-				mnt_group_start,
-				&mnt->mnt_group_id);
-	if (!res)
-		mnt_group_start = mnt->mnt_group_id + 1;
-
-	return res;
-}
-
-/*
- * Release a peer group ID
- */
-void mnt_release_group_id(struct mount *mnt)
-{
-	int id = mnt->mnt_group_id;
-	ida_remove(&mnt_group_ida, id);
-	if (mnt_group_start > id)
-		mnt_group_start = id;
-	mnt->mnt_group_id = 0;
-}
-
-/*
- * vfsmount lock must be held for read
- */
-static inline void mnt_add_count(struct mount *mnt, int n)
-{
-#ifdef CONFIG_SMP
-	this_cpu_add(mnt->mnt_pcp->mnt_count, n);
-#else
-	preempt_disable();
-	mnt->mnt_count += n;
-	preempt_enable();
-#endif
-}
-
-/*
- * vfsmount lock must be held for write
- */
-unsigned int mnt_get_count(struct mount *mnt)
-{
-#ifdef CONFIG_SMP
-	unsigned int count = 0;
-	int cpu;
-
-	for_each_possible_cpu(cpu) {
-		count += per_cpu_ptr(mnt->mnt_pcp, cpu)->mnt_count;
-	}
-
-	return count;
-#else
-	return mnt->mnt_count;
-#endif
-}
-
-static struct mount *alloc_vfsmnt(const char *name)
-{
-	struct mount *mnt = kmem_cache_zalloc(mnt_cache, GFP_KERNEL);
-	if (mnt) {
-		int err;
-
-		err = mnt_alloc_id(mnt);
-		if (err)
-			goto out_free_cache;
-
-		if (name) {
-			mnt->mnt_devname = kstrdup(name, GFP_KERNEL);
-			if (!mnt->mnt_devname)
-				goto out_free_id;
-		}
-
-#ifdef CONFIG_SMP
-		mnt->mnt_pcp = alloc_percpu(struct mnt_pcp);
-		if (!mnt->mnt_pcp)
-			goto out_free_devname;
-
-		this_cpu_add(mnt->mnt_pcp->mnt_count, 1);
-#else
-		mnt->mnt_count = 1;
-		mnt->mnt_writers = 0;
-#endif
-
-		INIT_LIST_HEAD(&mnt->mnt_hash);
-		INIT_LIST_HEAD(&mnt->mnt_child);
-		INIT_LIST_HEAD(&mnt->mnt_mounts);
-		INIT_LIST_HEAD(&mnt->mnt_list);
-		INIT_LIST_HEAD(&mnt->mnt_expire);
-		INIT_LIST_HEAD(&mnt->mnt_share);
-		INIT_LIST_HEAD(&mnt->mnt_slave_list);
-		INIT_LIST_HEAD(&mnt->mnt_slave);
-#ifdef CONFIG_FSNOTIFY
-		INIT_HLIST_HEAD(&mnt->mnt_fsnotify_marks);
-#endif
-	}
-	return mnt;
-
-#ifdef CONFIG_SMP
-out_free_devname:
-	kfree(mnt->mnt_devname);
-#endif
-out_free_id:
-	mnt_free_id(mnt);
-out_free_cache:
-	kmem_cache_free(mnt_cache, mnt);
-	return NULL;
-}
-
-/*
- * Most r/o checks on a fs are for operations that take
- * discrete amounts of time, like a write() or unlink().
- * We must keep track of when those operations start
- * (for permission checks) and when they end, so that
- * we can determine when writes are able to occur to
- * a filesystem.
- */
-/*
- * __mnt_is_readonly: check whether a mount is read-only
- * @mnt: the mount to check for its write status
- *
- * This shouldn't be used directly ouside of the VFS.
- * It does not guarantee that the filesystem will stay
- * r/w, just that it is right *now*.  This can not and
- * should not be used in place of IS_RDONLY(inode).
- * mnt_want/drop_write() will _keep_ the filesystem
- * r/w.
- */
-int __mnt_is_readonly(struct vfsmount *mnt)
-{
-	if (mnt->mnt_flags & MNT_READONLY)
-		return 1;
-	if (mnt->mnt_sb->s_flags & MS_RDONLY)
-		return 1;
-	return 0;
-}
-EXPORT_SYMBOL_GPL(__mnt_is_readonly);
-
-static inline void mnt_inc_writers(struct mount *mnt)
-{
-#ifdef CONFIG_SMP
-	this_cpu_inc(mnt->mnt_pcp->mnt_writers);
-#else
-	mnt->mnt_writers++;
-#endif
-}
-
-static inline void mnt_dec_writers(struct mount *mnt)
-{
-#ifdef CONFIG_SMP
-	this_cpu_dec(mnt->mnt_pcp->mnt_writers);
-#else
-	mnt->mnt_writers--;
-#endif
-}
-
-static unsigned int mnt_get_writers(struct mount *mnt)
-{
-#ifdef CONFIG_SMP
-	unsigned int count = 0;
-	int cpu;
-
-	for_each_possible_cpu(cpu) {
-		count += per_cpu_ptr(mnt->mnt_pcp, cpu)->mnt_writers;
-	}
-
-	return count;
-#else
-	return mnt->mnt_writers;
-#endif
-}
-
-static int mnt_is_readonly(struct vfsmount *mnt)
-{
-	if (mnt->mnt_sb->s_readonly_remount)
-		return 1;
-	/* Order wrt setting s_flags/s_readonly_remount in do_remount() */
-	smp_rmb();
-	return __mnt_is_readonly(mnt);
-}
-
-/*
- * Most r/o checks on a fs are for operations that take
- * discrete amounts of time, like a write() or unlink().
- * We must keep track of when those operations start
- * (for permission checks) and when they end, so that
- * we can determine when writes are able to occur to
- * a filesystem.
- */
-/**
- * mnt_want_write - get write access to a mount
- * @m: the mount on which to take a write
- *
- * This tells the low-level filesystem that a write is
- * about to be performed to it, and makes sure that
- * writes are allowed before returning success.  When
- * the write operation is finished, mnt_drop_write()
- * must be called.  This is effectively a refcount.
- */
-int mnt_want_write(struct vfsmount *m)
-{
-	struct mount *mnt = real_mount(m);
-	int ret = 0;
-
-	preempt_disable();
-	mnt_inc_writers(mnt);
-	/*
-	 * The store to mnt_inc_writers must be visible before we pass
-	 * MNT_WRITE_HOLD loop below, so that the slowpath can see our
-	 * incremented count after it has set MNT_WRITE_HOLD.
-	 */
-	smp_mb();
-	while (mnt->mnt.mnt_flags & MNT_WRITE_HOLD)
-		cpu_relax();
-	/*
-	 * After the slowpath clears MNT_WRITE_HOLD, mnt_is_readonly will
-	 * be set to match its requirements. So we must not load that until
-	 * MNT_WRITE_HOLD is cleared.
-	 */
-	smp_rmb();
-	if (mnt_is_readonly(m)) {
-		mnt_dec_writers(mnt);
-		ret = -EROFS;
-	}
-	preempt_enable();
-	return ret;
-}
-EXPORT_SYMBOL_GPL(mnt_want_write);
-
-/**
- * mnt_clone_write - get write access to a mount
- * @mnt: the mount on which to take a write
- *
- * This is effectively like mnt_want_write, except
- * it must only be used to take an extra write reference
- * on a mountpoint that we already know has a write reference
- * on it. This allows some optimisation.
- *
- * After finished, mnt_drop_write must be called as usual to
- * drop the reference.
- */
-int mnt_clone_write(struct vfsmount *mnt)
-{
-	/* superblock may be r/o */
-	if (__mnt_is_readonly(mnt))
-		return -EROFS;
-	preempt_disable();
-	mnt_inc_writers(real_mount(mnt));
-	preempt_enable();
-	return 0;
-}
-EXPORT_SYMBOL_GPL(mnt_clone_write);
-
-/**
- * mnt_want_write_file - get write access to a file's mount
- * @file: the file who's mount on which to take a write
- *
- * This is like mnt_want_write, but it takes a file and can
- * do some optimisations if the file is open for write already
- */
-int mnt_want_write_file(struct file *file)
-{
-	struct inode *inode = file->f_dentry->d_inode;
-	if (!(file->f_mode & FMODE_WRITE) || special_file(inode->i_mode))
-		return mnt_want_write(file->f_path.mnt);
-	else
-		return mnt_clone_write(file->f_path.mnt);
-}
-EXPORT_SYMBOL_GPL(mnt_want_write_file);
-
-/**
- * mnt_drop_write - give up write access to a mount
- * @mnt: the mount on which to give up write access
- *
- * Tells the low-level filesystem that we are done
- * performing writes to it.  Must be matched with
- * mnt_want_write() call above.
- */
-void mnt_drop_write(struct vfsmount *mnt)
-{
-	preempt_disable();
-	mnt_dec_writers(real_mount(mnt));
-	preempt_enable();
-}
-EXPORT_SYMBOL_GPL(mnt_drop_write);
-
-void mnt_drop_write_file(struct file *file)
-{
-	mnt_drop_write(file->f_path.mnt);
-}
-EXPORT_SYMBOL(mnt_drop_write_file);
-
-static int mnt_make_readonly(struct mount *mnt)
-{
-	int ret = 0;
-
-	br_write_lock(vfsmount_lock);
-	mnt->mnt.mnt_flags |= MNT_WRITE_HOLD;
-	/*
-	 * After storing MNT_WRITE_HOLD, we'll read the counters. This store
-	 * should be visible before we do.
-	 */
-	smp_mb();
-
-	/*
-	 * With writers on hold, if this value is zero, then there are
-	 * definitely no active writers (although held writers may subsequently
-	 * increment the count, they'll have to wait, and decrement it after
-	 * seeing MNT_READONLY).
-	 *
-	 * It is OK to have counter incremented on one CPU and decremented on
-	 * another: the sum will add up correctly. The danger would be when we
-	 * sum up each counter, if we read a counter before it is incremented,
-	 * but then read another CPU's count which it has been subsequently
-	 * decremented from -- we would see more decrements than we should.
-	 * MNT_WRITE_HOLD protects against this scenario, because
-	 * mnt_want_write first increments count, then smp_mb, then spins on
-	 * MNT_WRITE_HOLD, so it can't be decremented by another CPU while
-	 * we're counting up here.
-	 */
-	if (mnt_get_writers(mnt) > 0)
-		ret = -EBUSY;
-	else
-		mnt->mnt.mnt_flags |= MNT_READONLY;
-	/*
-	 * MNT_READONLY must become visible before ~MNT_WRITE_HOLD, so writers
-	 * that become unheld will see MNT_READONLY.
-	 */
-	smp_wmb();
-	mnt->mnt.mnt_flags &= ~MNT_WRITE_HOLD;
-	br_write_unlock(vfsmount_lock);
-	return ret;
-}
-
-static void __mnt_unmake_readonly(struct mount *mnt)
-{
-	br_write_lock(vfsmount_lock);
-	mnt->mnt.mnt_flags &= ~MNT_READONLY;
-	br_write_unlock(vfsmount_lock);
-}
-
-int sb_prepare_remount_readonly(struct super_block *sb)
-{
-	struct mount *mnt;
-	int err = 0;
-
-	/* Racy optimization.  Recheck the counter under MNT_WRITE_HOLD */
-	if (atomic_long_read(&sb->s_remove_count))
-		return -EBUSY;
-
-	br_write_lock(vfsmount_lock);
-	list_for_each_entry(mnt, &sb->s_mounts, mnt_instance) {
-		if (!(mnt->mnt.mnt_flags & MNT_READONLY)) {
-			mnt->mnt.mnt_flags |= MNT_WRITE_HOLD;
-			smp_mb();
-			if (mnt_get_writers(mnt) > 0) {
-				err = -EBUSY;
-				break;
-			}
-		}
-	}
-	if (!err && atomic_long_read(&sb->s_remove_count))
-		err = -EBUSY;
-
-	if (!err) {
-		sb->s_readonly_remount = 1;
-		smp_wmb();
-	}
-	list_for_each_entry(mnt, &sb->s_mounts, mnt_instance) {
-		if (mnt->mnt.mnt_flags & MNT_WRITE_HOLD)
-			mnt->mnt.mnt_flags &= ~MNT_WRITE_HOLD;
-	}
-	br_write_unlock(vfsmount_lock);
-
-	return err;
-}
-
-static void free_vfsmnt(struct mount *mnt)
-{
-	kfree(mnt->mnt_devname);
-	mnt_free_id(mnt);
-#ifdef CONFIG_SMP
-	free_percpu(mnt->mnt_pcp);
-#endif
-	kmem_cache_free(mnt_cache, mnt);
-}
-
-/*
- * find the first or last mount at @dentry on vfsmount @mnt depending on
- * @dir. If @dir is set return the first mount else return the last mount.
- * vfsmount_lock must be held for read or write.
- */
-struct mount *__lookup_mnt(struct vfsmount *mnt, struct dentry *dentry,
-			      int dir)
-{
-	struct list_head *head = mount_hashtable + hash(mnt, dentry);
-	struct list_head *tmp = head;
-	struct mount *p, *found = NULL;
-
-	for (;;) {
-		tmp = dir ? tmp->next : tmp->prev;
-		p = NULL;
-		if (tmp == head)
-			break;
-		p = list_entry(tmp, struct mount, mnt_hash);
-		if (&p->mnt_parent->mnt == mnt && p->mnt_mountpoint == dentry) {
-			found = p;
-			break;
-		}
-	}
-	return found;
-}
-
-/*
- * lookup_mnt increments the ref count before returning
- * the vfsmount struct.
- */
-struct vfsmount *lookup_mnt(struct path *path)
-{
-	struct mount *child_mnt;
-
-	br_read_lock(vfsmount_lock);
-	child_mnt = __lookup_mnt(path->mnt, path->dentry, 1);
-	if (child_mnt) {
-		mnt_add_count(child_mnt, 1);
-		br_read_unlock(vfsmount_lock);
-		return &child_mnt->mnt;
-	} else {
-		br_read_unlock(vfsmount_lock);
-		return NULL;
-	}
-}
-
-static inline int check_mnt(struct mount *mnt)
-{
-	return mnt->mnt_ns == current->nsproxy->mnt_ns;
-}
-
-/*
- * vfsmount lock must be held for write
- */
-static void touch_mnt_namespace(struct mnt_namespace *ns)
-{
-	if (ns) {
-		ns->event = ++event;
-		wake_up_interruptible(&ns->poll);
-	}
-}
-
-/*
- * vfsmount lock must be held for write
- */
-static void __touch_mnt_namespace(struct mnt_namespace *ns)
-{
-	if (ns && ns->event != event) {
-		ns->event = event;
-		wake_up_interruptible(&ns->poll);
-	}
-}
-
-/*
- * Clear dentry's mounted state if it has no remaining mounts.
- * vfsmount_lock must be held for write.
- */
-static void dentry_reset_mounted(struct dentry *dentry)
-{
-	unsigned u;
-
-	for (u = 0; u < HASH_SIZE; u++) {
-		struct mount *p;
-
-		list_for_each_entry(p, &mount_hashtable[u], mnt_hash) {
-			if (p->mnt_mountpoint == dentry)
-				return;
-		}
-	}
-	spin_lock(&dentry->d_lock);
-	dentry->d_flags &= ~DCACHE_MOUNTED;
-	spin_unlock(&dentry->d_lock);
-}
-
-/*
- * vfsmount lock must be held for write
- */
-static void detach_mnt(struct mount *mnt, struct path *old_path)
-{
-	old_path->dentry = mnt->mnt_mountpoint;
-	old_path->mnt = &mnt->mnt_parent->mnt;
-	mnt->mnt_parent = mnt;
-	mnt->mnt_mountpoint = mnt->mnt.mnt_root;
-	list_del_init(&mnt->mnt_child);
-	list_del_init(&mnt->mnt_hash);
-	dentry_reset_mounted(old_path->dentry);
-}
-
-/*
- * vfsmount lock must be held for write
- */
-void mnt_set_mountpoint(struct mount *mnt, struct dentry *dentry,
-			struct mount *child_mnt)
-{
-	mnt_add_count(mnt, 1);	/* essentially, that's mntget */
-	child_mnt->mnt_mountpoint = dget(dentry);
-	child_mnt->mnt_parent = mnt;
-	spin_lock(&dentry->d_lock);
-	dentry->d_flags |= DCACHE_MOUNTED;
-	spin_unlock(&dentry->d_lock);
-}
-
-/*
- * vfsmount lock must be held for write
- */
-static void attach_mnt(struct mount *mnt, struct path *path)
-{
-	mnt_set_mountpoint(real_mount(path->mnt), path->dentry, mnt);
-	list_add_tail(&mnt->mnt_hash, mount_hashtable +
-			hash(path->mnt, path->dentry));
-	list_add_tail(&mnt->mnt_child, &real_mount(path->mnt)->mnt_mounts);
-}
-
-static inline void __mnt_make_longterm(struct mount *mnt)
-{
-#ifdef CONFIG_SMP
-	atomic_inc(&mnt->mnt_longterm);
-#endif
-}
-
-/* needs vfsmount lock for write */
-static inline void __mnt_make_shortterm(struct mount *mnt)
-{
-#ifdef CONFIG_SMP
-	atomic_dec(&mnt->mnt_longterm);
-#endif
-}
-
-/*
- * vfsmount lock must be held for write
- */
-static void commit_tree(struct mount *mnt)
-{
-	struct mount *parent = mnt->mnt_parent;
-	struct mount *m;
-	LIST_HEAD(head);
-	struct mnt_namespace *n = parent->mnt_ns;
-
-	BUG_ON(parent == mnt);
-
-	list_add_tail(&head, &mnt->mnt_list);
-	list_for_each_entry(m, &head, mnt_list) {
-		m->mnt_ns = n;
-		__mnt_make_longterm(m);
-	}
-
-	list_splice(&head, n->list.prev);
-
-	list_add_tail(&mnt->mnt_hash, mount_hashtable +
-				hash(&parent->mnt, mnt->mnt_mountpoint));
-	list_add_tail(&mnt->mnt_child, &parent->mnt_mounts);
-	touch_mnt_namespace(n);
-}
-
-static struct mount *next_mnt(struct mount *p, struct mount *root)
-{
-	struct list_head *next = p->mnt_mounts.next;
-	if (next == &p->mnt_mounts) {
-		while (1) {
-			if (p == root)
-				return NULL;
-			next = p->mnt_child.next;
-			if (next != &p->mnt_parent->mnt_mounts)
-				break;
-			p = p->mnt_parent;
-		}
-	}
-	return list_entry(next, struct mount, mnt_child);
-}
-
-static struct mount *skip_mnt_tree(struct mount *p)
-{
-	struct list_head *prev = p->mnt_mounts.prev;
-	while (prev != &p->mnt_mounts) {
-		p = list_entry(prev, struct mount, mnt_child);
-		prev = p->mnt_mounts.prev;
-	}
-	return p;
-}
-
-struct vfsmount *
-vfs_kern_mount(struct file_system_type *type, int flags, const char *name, void *data)
-{
-	struct mount *mnt;
-	struct dentry *root;
-
-	if (!type)
-		return ERR_PTR(-ENODEV);
-
-	mnt = alloc_vfsmnt(name);
-	if (!mnt)
-		return ERR_PTR(-ENOMEM);
-
-	if (flags & MS_KERNMOUNT)
-		mnt->mnt.mnt_flags = MNT_INTERNAL;
-
-	root = mount_fs(type, flags, name, data);
-	if (IS_ERR(root)) {
-		free_vfsmnt(mnt);
-		return ERR_CAST(root);
-	}
-
-	mnt->mnt.mnt_root = root;
-	mnt->mnt.mnt_sb = root->d_sb;
-	mnt->mnt_mountpoint = mnt->mnt.mnt_root;
-	mnt->mnt_parent = mnt;
-	br_write_lock(vfsmount_lock);
-	list_add_tail(&mnt->mnt_instance, &root->d_sb->s_mounts);
-	br_write_unlock(vfsmount_lock);
-	return &mnt->mnt;
-}
-EXPORT_SYMBOL_GPL(vfs_kern_mount);
-
-static struct mount *clone_mnt(struct mount *old, struct dentry *root,
-					int flag)
-{
-	struct super_block *sb = old->mnt.mnt_sb;
-	struct mount *mnt = alloc_vfsmnt(old->mnt_devname);
-
-	if (mnt) {
-		if (flag & (CL_SLAVE | CL_PRIVATE))
-			mnt->mnt_group_id = 0; /* not a peer of original */
-		else
-			mnt->mnt_group_id = old->mnt_group_id;
-
-		if ((flag & CL_MAKE_SHARED) && !mnt->mnt_group_id) {
-			int err = mnt_alloc_group_id(mnt);
-			if (err)
-				goto out_free;
-		}
-
-		mnt->mnt.mnt_flags = old->mnt.mnt_flags & ~MNT_WRITE_HOLD;
-		atomic_inc(&sb->s_active);
-		mnt->mnt.mnt_sb = sb;
-		mnt->mnt.mnt_root = dget(root);
-		mnt->mnt_mountpoint = mnt->mnt.mnt_root;
-		mnt->mnt_parent = mnt;
-		br_write_lock(vfsmount_lock);
-		list_add_tail(&mnt->mnt_instance, &sb->s_mounts);
-		br_write_unlock(vfsmount_lock);
-
-		if (flag & CL_SLAVE) {
-			list_add(&mnt->mnt_slave, &old->mnt_slave_list);
-			mnt->mnt_master = old;
-			CLEAR_MNT_SHARED(mnt);
-		} else if (!(flag & CL_PRIVATE)) {
-			if ((flag & CL_MAKE_SHARED) || IS_MNT_SHARED(old))
-				list_add(&mnt->mnt_share, &old->mnt_share);
-			if (IS_MNT_SLAVE(old))
-				list_add(&mnt->mnt_slave, &old->mnt_slave);
-			mnt->mnt_master = old->mnt_master;
-		}
-		if (flag & CL_MAKE_SHARED)
-			set_mnt_shared(mnt);
-
-		/* stick the duplicate mount on the same expiry list
-		 * as the original if that was on one */
-		if (flag & CL_EXPIRE) {
-			if (!list_empty(&old->mnt_expire))
-				list_add(&mnt->mnt_expire, &old->mnt_expire);
-		}
-	}
-	return mnt;
-
- out_free:
-	free_vfsmnt(mnt);
-	return NULL;
-}
-
-static inline void mntfree(struct mount *mnt)
-{
-	struct vfsmount *m = &mnt->mnt;
-	struct super_block *sb = m->mnt_sb;
-
-	/*
-	 * This probably indicates that somebody messed
-	 * up a mnt_want/drop_write() pair.  If this
-	 * happens, the filesystem was probably unable
-	 * to make r/w->r/o transitions.
-	 */
-	/*
-	 * The locking used to deal with mnt_count decrement provides barriers,
-	 * so mnt_get_writers() below is safe.
-	 */
-	WARN_ON(mnt_get_writers(mnt));
-	fsnotify_vfsmount_delete(m);
-	dput(m->mnt_root);
-	free_vfsmnt(mnt);
-	deactivate_super(sb);
-}
-
-static void mntput_no_expire(struct mount *mnt)
-{
-put_again:
-#ifdef CONFIG_SMP
-	br_read_lock(vfsmount_lock);
-	if (likely(atomic_read(&mnt->mnt_longterm))) {
-		mnt_add_count(mnt, -1);
-		br_read_unlock(vfsmount_lock);
-		return;
-	}
-	br_read_unlock(vfsmount_lock);
-
-	br_write_lock(vfsmount_lock);
-	mnt_add_count(mnt, -1);
-	if (mnt_get_count(mnt)) {
-		br_write_unlock(vfsmount_lock);
-		return;
-	}
-#else
-	mnt_add_count(mnt, -1);
-	if (likely(mnt_get_count(mnt)))
-		return;
-	br_write_lock(vfsmount_lock);
-#endif
-	if (unlikely(mnt->mnt_pinned)) {
-		mnt_add_count(mnt, mnt->mnt_pinned + 1);
-		mnt->mnt_pinned = 0;
-		br_write_unlock(vfsmount_lock);
-		acct_auto_close_mnt(&mnt->mnt);
-		goto put_again;
-	}
-	list_del(&mnt->mnt_instance);
-	br_write_unlock(vfsmount_lock);
-	mntfree(mnt);
-}
-
-void mntput(struct vfsmount *mnt)
-{
-	if (mnt) {
-		struct mount *m = real_mount(mnt);
-		/* avoid cacheline pingpong, hope gcc doesn't get "smart" */
-		if (unlikely(m->mnt_expiry_mark))
-			m->mnt_expiry_mark = 0;
-		mntput_no_expire(m);
-	}
-}
-EXPORT_SYMBOL(mntput);
-
-struct vfsmount *mntget(struct vfsmount *mnt)
-{
-	if (mnt)
-		mnt_add_count(real_mount(mnt), 1);
-	return mnt;
-}
-EXPORT_SYMBOL(mntget);
-
-void mnt_pin(struct vfsmount *mnt)
-{
-	br_write_lock(vfsmount_lock);
-	real_mount(mnt)->mnt_pinned++;
-	br_write_unlock(vfsmount_lock);
-}
-EXPORT_SYMBOL(mnt_pin);
-
-void mnt_unpin(struct vfsmount *m)
-{
-	struct mount *mnt = real_mount(m);
-	br_write_lock(vfsmount_lock);
-	if (mnt->mnt_pinned) {
-		mnt_add_count(mnt, 1);
-		mnt->mnt_pinned--;
-	}
-	br_write_unlock(vfsmount_lock);
-}
-EXPORT_SYMBOL(mnt_unpin);
-
-static inline void mangle(struct seq_file *m, const char *s)
-{
-	seq_escape(m, s, " \t\n\\");
-}
-
-/*
- * Simple .show_options callback for filesystems which don't want to
- * implement more complex mount option showing.
- *
- * See also save_mount_options().
- */
-int generic_show_options(struct seq_file *m, struct dentry *root)
-{
-	const char *options;
-
-	rcu_read_lock();
-	options = rcu_dereference(root->d_sb->s_options);
-
-	if (options != NULL && options[0]) {
-		seq_putc(m, ',');
-		mangle(m, options);
-	}
-	rcu_read_unlock();
-
-	return 0;
-}
-EXPORT_SYMBOL(generic_show_options);
-
-/*
- * If filesystem uses generic_show_options(), this function should be
- * called from the fill_super() callback.
- *
- * The .remount_fs callback usually needs to be handled in a special
- * way, to make sure, that previous options are not overwritten if the
- * remount fails.
- *
- * Also note, that if the filesystem's .remount_fs function doesn't
- * reset all options to their default value, but changes only newly
- * given options, then the displayed options will not reflect reality
- * any more.
- */
-void save_mount_options(struct super_block *sb, char *options)
-{
-	BUG_ON(sb->s_options);
-	rcu_assign_pointer(sb->s_options, kstrdup(options, GFP_KERNEL));
-}
-EXPORT_SYMBOL(save_mount_options);
-
-void replace_mount_options(struct super_block *sb, char *options)
-{
-	char *old = sb->s_options;
-	rcu_assign_pointer(sb->s_options, options);
-	if (old) {
-		synchronize_rcu();
-		kfree(old);
-	}
-}
-EXPORT_SYMBOL(replace_mount_options);
-
-#ifdef CONFIG_PROC_FS
-/* iterator; we want it to have access to namespace_sem, thus here... */
-static void *m_start(struct seq_file *m, loff_t *pos)
-{
-	struct proc_mounts *p = container_of(m, struct proc_mounts, m);
-
-	down_read(&namespace_sem);
-	return seq_list_start(&p->ns->list, *pos);
-}
-
-static void *m_next(struct seq_file *m, void *v, loff_t *pos)
-{
-	struct proc_mounts *p = container_of(m, struct proc_mounts, m);
-
-	return seq_list_next(v, &p->ns->list, pos);
-}
-
-static void m_stop(struct seq_file *m, void *v)
-{
-	up_read(&namespace_sem);
-}
-
-static int m_show(struct seq_file *m, void *v)
-{
-	struct proc_mounts *p = container_of(m, struct proc_mounts, m);
-	struct mount *r = list_entry(v, struct mount, mnt_list);
-	return p->show(m, &r->mnt);
-}
-
-const struct seq_operations mounts_op = {
-	.start	= m_start,
-	.next	= m_next,
-	.stop	= m_stop,
-	.show	= m_show,
-};
-#endif  /* CONFIG_PROC_FS */
-
-/**
- * may_umount_tree - check if a mount tree is busy
- * @mnt: root of mount tree
- *
- * This is called to check if a tree of mounts has any
- * open files, pwds, chroots or sub mounts that are
- * busy.
- */
-int may_umount_tree(struct vfsmount *m)
-{
-	struct mount *mnt = real_mount(m);
-	int actual_refs = 0;
-	int minimum_refs = 0;
-	struct mount *p;
-	BUG_ON(!m);
-
-	/* write lock needed for mnt_get_count */
-	br_write_lock(vfsmount_lock);
-	for (p = mnt; p; p = next_mnt(p, mnt)) {
-		actual_refs += mnt_get_count(p);
-		minimum_refs += 2;
-	}
-	br_write_unlock(vfsmount_lock);
-
-	if (actual_refs > minimum_refs)
-		return 0;
-
-	return 1;
-}
-
-EXPORT_SYMBOL(may_umount_tree);
-
-/**
- * may_umount - check if a mount point is busy
- * @mnt: root of mount
- *
- * This is called to check if a mount point has any
- * open files, pwds, chroots or sub mounts. If the
- * mount has sub mounts this will return busy
- * regardless of whether the sub mounts are busy.
- *
- * Doesn't take quota and stuff into account. IOW, in some cases it will
- * give false negatives. The main reason why it's here is that we need
- * a non-destructive way to look for easily umountable filesystems.
- */
-int may_umount(struct vfsmount *mnt)
-{
-	int ret = 1;
-	down_read(&namespace_sem);
-	br_write_lock(vfsmount_lock);
-	if (propagate_mount_busy(real_mount(mnt), 2))
-		ret = 0;
-	br_write_unlock(vfsmount_lock);
-	up_read(&namespace_sem);
-	return ret;
-}
-
-EXPORT_SYMBOL(may_umount);
-
-void release_mounts(struct list_head *head)
-{
-	struct mount *mnt;
-	while (!list_empty(head)) {
-		mnt = list_first_entry(head, struct mount, mnt_hash);
-		list_del_init(&mnt->mnt_hash);
-		if (mnt_has_parent(mnt)) {
-			struct dentry *dentry;
-			struct mount *m;
-
-			br_write_lock(vfsmount_lock);
-			dentry = mnt->mnt_mountpoint;
-			m = mnt->mnt_parent;
-			mnt->mnt_mountpoint = mnt->mnt.mnt_root;
-			mnt->mnt_parent = mnt;
-			m->mnt_ghosts--;
-			br_write_unlock(vfsmount_lock);
-			dput(dentry);
-			mntput(&m->mnt);
-		}
-		mntput(&mnt->mnt);
-	}
-}
-
-/*
- * vfsmount lock must be held for write
- * namespace_sem must be held for write
- */
-void umount_tree(struct mount *mnt, int propagate, struct list_head *kill)
-{
-	LIST_HEAD(tmp_list);
-	struct mount *p;
-
-	for (p = mnt; p; p = next_mnt(p, mnt))
-		list_move(&p->mnt_hash, &tmp_list);
-
-	if (propagate)
-		propagate_umount(&tmp_list);
-
-	list_for_each_entry(p, &tmp_list, mnt_hash) {
-		list_del_init(&p->mnt_expire);
-		list_del_init(&p->mnt_list);
-		__touch_mnt_namespace(p->mnt_ns);
-		if (p->mnt_ns)
-			__mnt_make_shortterm(p);
-		p->mnt_ns = NULL;
-		list_del_init(&p->mnt_child);
-		if (mnt_has_parent(p)) {
-			p->mnt_parent->mnt_ghosts++;
-			dentry_reset_mounted(p->mnt_mountpoint);
-		}
-		change_mnt_propagation(p, MS_PRIVATE);
-	}
-	list_splice(&tmp_list, kill);
-}
-
-static void shrink_submounts(struct mount *mnt, struct list_head *umounts);
-
-static int do_umount(struct mount *mnt, int flags)
-{
-	struct super_block *sb = mnt->mnt.mnt_sb;
-	int retval;
-	LIST_HEAD(umount_list);
-
-	retval = security_sb_umount(&mnt->mnt, flags);
-	if (retval)
-		return retval;
-
-	/*
-	 * Allow userspace to request a mountpoint be expired rather than
-	 * unmounting unconditionally. Unmount only happens if:
-	 *  (1) the mark is already set (the mark is cleared by mntput())
-	 *  (2) the usage count == 1 [parent vfsmount] + 1 [sys_umount]
-	 */
-	if (flags & MNT_EXPIRE) {
-		if (&mnt->mnt == current->fs->root.mnt ||
-		    flags & (MNT_FORCE | MNT_DETACH))
-			return -EINVAL;
-
-		/*
-		 * probably don't strictly need the lock here if we examined
-		 * all race cases, but it's a slowpath.
-		 */
-		br_write_lock(vfsmount_lock);
-		if (mnt_get_count(mnt) != 2) {
-			br_write_unlock(vfsmount_lock);
-			return -EBUSY;
-		}
-		br_write_unlock(vfsmount_lock);
-
-		if (!xchg(&mnt->mnt_expiry_mark, 1))
-			return -EAGAIN;
-	}
-
-	/*
-	 * If we may have to abort operations to get out of this
-	 * mount, and they will themselves hold resources we must
-	 * allow the fs to do things. In the Unix tradition of
-	 * 'Gee thats tricky lets do it in userspace' the umount_begin
-	 * might fail to complete on the first run through as other tasks
-	 * must return, and the like. Thats for the mount program to worry
-	 * about for the moment.
-	 */
-
-	if (flags & MNT_FORCE && sb->s_op->umount_begin) {
-		sb->s_op->umount_begin(sb);
-	}
-
-	/*
-	 * No sense to grab the lock for this test, but test itself looks
-	 * somewhat bogus. Suggestions for better replacement?
-	 * Ho-hum... In principle, we might treat that as umount + switch
-	 * to rootfs. GC would eventually take care of the old vfsmount.
-	 * Actually it makes sense, especially if rootfs would contain a
-	 * /reboot - static binary that would close all descriptors and
-	 * call reboot(9). Then init(8) could umount root and exec /reboot.
-	 */
-	if (&mnt->mnt == current->fs->root.mnt && !(flags & MNT_DETACH)) {
-		/*
-		 * Special case for "unmounting" root ...
-		 * we just try to remount it readonly.
-		 */
-		down_write(&sb->s_umount);
-		if (!(sb->s_flags & MS_RDONLY))
-			retval = do_remount_sb(sb, MS_RDONLY, NULL, 0);
-		up_write(&sb->s_umount);
-		return retval;
-	}
-
-	down_write(&namespace_sem);
-	br_write_lock(vfsmount_lock);
-	event++;
-
-	if (!(flags & MNT_DETACH))
-		shrink_submounts(mnt, &umount_list);
-
-	retval = -EBUSY;
-	if (flags & MNT_DETACH || !propagate_mount_busy(mnt, 2)) {
-		if (!list_empty(&mnt->mnt_list))
-			umount_tree(mnt, 1, &umount_list);
-		retval = 0;
-	}
-	br_write_unlock(vfsmount_lock);
-	up_write(&namespace_sem);
-	release_mounts(&umount_list);
-	return retval;
-}
-
-/*
- * Now umount can handle mount points as well as block devices.
- * This is important for filesystems which use unnamed block devices.
- *
- * We now support a flag for forced unmount like the other 'big iron'
- * unixes. Our API is identical to OSF/1 to avoid making a mess of AMD
- */
-
-SYSCALL_DEFINE2(umount, char __user *, name, int, flags)
-{
-	struct path path;
-	struct mount *mnt;
-	int retval;
-	int lookup_flags = 0;
-
-	if (flags & ~(MNT_FORCE | MNT_DETACH | MNT_EXPIRE | UMOUNT_NOFOLLOW))
-		return -EINVAL;
-
-	if (!(flags & UMOUNT_NOFOLLOW))
-		lookup_flags |= LOOKUP_FOLLOW;
-
-	retval = user_path_at(AT_FDCWD, name, lookup_flags, &path);
-	if (retval)
-		goto out;
-	mnt = real_mount(path.mnt);
-	retval = -EINVAL;
-	if (path.dentry != path.mnt->mnt_root)
-		goto dput_and_out;
-	if (!check_mnt(mnt))
-		goto dput_and_out;
-
-	retval = -EPERM;
-	if (!capable(CAP_SYS_ADMIN))
-		goto dput_and_out;
-
-	retval = do_umount(mnt, flags);
-dput_and_out:
-	/* we mustn't call path_put() as that would clear mnt_expiry_mark */
-	dput(path.dentry);
-	mntput_no_expire(mnt);
-out:
-	return retval;
-}
-
-#ifdef __ARCH_WANT_SYS_OLDUMOUNT
-
-/*
- *	The 2.0 compatible umount. No flags.
- */
-SYSCALL_DEFINE1(oldumount, char __user *, name)
-{
-	return sys_umount(name, 0);
-}
-
-#endif
-
-static int mount_is_safe(struct path *path)
-{
-	if (capable(CAP_SYS_ADMIN))
-		return 0;
-	return -EPERM;
-#ifdef notyet
-	if (S_ISLNK(path->dentry->d_inode->i_mode))
-		return -EPERM;
-	if (path->dentry->d_inode->i_mode & S_ISVTX) {
-		if (current_uid() != path->dentry->d_inode->i_uid)
-			return -EPERM;
-	}
-	if (inode_permission(path->dentry->d_inode, MAY_WRITE))
-		return -EPERM;
-	return 0;
-#endif
-}
-
-struct mount *copy_tree(struct mount *mnt, struct dentry *dentry,
-					int flag)
-{
-	struct mount *res, *p, *q, *r;
-	struct path path;
-
-	if (!(flag & CL_COPY_ALL) && IS_MNT_UNBINDABLE(mnt))
-		return NULL;
-
-	res = q = clone_mnt(mnt, dentry, flag);
-	if (!q)
-		goto Enomem;
-	q->mnt_mountpoint = mnt->mnt_mountpoint;
-
-	p = mnt;
-	list_for_each_entry(r, &mnt->mnt_mounts, mnt_child) {
-		struct mount *s;
-		if (!is_subdir(r->mnt_mountpoint, dentry))
-			continue;
-
-		for (s = r; s; s = next_mnt(s, r)) {
-			if (!(flag & CL_COPY_ALL) && IS_MNT_UNBINDABLE(s)) {
-				s = skip_mnt_tree(s);
-				continue;
-			}
-			while (p != s->mnt_parent) {
-				p = p->mnt_parent;
-				q = q->mnt_parent;
-			}
-			p = s;
-			path.mnt = &q->mnt;
-			path.dentry = p->mnt_mountpoint;
-			q = clone_mnt(p, p->mnt.mnt_root, flag);
-			if (!q)
-				goto Enomem;
-			br_write_lock(vfsmount_lock);
-			list_add_tail(&q->mnt_list, &res->mnt_list);
-			attach_mnt(q, &path);
-			br_write_unlock(vfsmount_lock);
-		}
-	}
-	return res;
-Enomem:
-	if (res) {
-		LIST_HEAD(umount_list);
-		br_write_lock(vfsmount_lock);
-		umount_tree(res, 0, &umount_list);
-		br_write_unlock(vfsmount_lock);
-		release_mounts(&umount_list);
-	}
-	return NULL;
-}
-
-struct vfsmount *collect_mounts(struct path *path)
-{
-	struct mount *tree;
-	down_write(&namespace_sem);
-	tree = copy_tree(real_mount(path->mnt), path->dentry,
-			 CL_COPY_ALL | CL_PRIVATE);
-	up_write(&namespace_sem);
-	return tree ? &tree->mnt : NULL;
-}
-
-void drop_collected_mounts(struct vfsmount *mnt)
-{
-	LIST_HEAD(umount_list);
-	down_write(&namespace_sem);
-	br_write_lock(vfsmount_lock);
-	umount_tree(real_mount(mnt), 0, &umount_list);
-	br_write_unlock(vfsmount_lock);
-	up_write(&namespace_sem);
-	release_mounts(&umount_list);
-}
-
-int iterate_mounts(int (*f)(struct vfsmount *, void *), void *arg,
-		   struct vfsmount *root)
-{
-	struct mount *mnt;
-	int res = f(root, arg);
-	if (res)
-		return res;
-	list_for_each_entry(mnt, &real_mount(root)->mnt_list, mnt_list) {
-		res = f(&mnt->mnt, arg);
-		if (res)
-			return res;
-	}
-	return 0;
-}
-
-static void cleanup_group_ids(struct mount *mnt, struct mount *end)
-{
-	struct mount *p;
-
-	for (p = mnt; p != end; p = next_mnt(p, mnt)) {
-		if (p->mnt_group_id && !IS_MNT_SHARED(p))
-			mnt_release_group_id(p);
-	}
-}
-
-static int invent_group_ids(struct mount *mnt, bool recurse)
-{
-	struct mount *p;
-
-	for (p = mnt; p; p = recurse ? next_mnt(p, mnt) : NULL) {
-		if (!p->mnt_group_id && !IS_MNT_SHARED(p)) {
-			int err = mnt_alloc_group_id(p);
-			if (err) {
-				cleanup_group_ids(mnt, p);
-				return err;
-			}
-		}
-	}
-
-	return 0;
-}
-
-/*
- *  @source_mnt : mount tree to be attached
- *  @nd         : place the mount tree @source_mnt is attached
- *  @parent_nd  : if non-null, detach the source_mnt from its parent and
- *  		   store the parent mount and mountpoint dentry.
- *  		   (done when source_mnt is moved)
- *
- *  NOTE: in the table below explains the semantics when a source mount
- *  of a given type is attached to a destination mount of a given type.
- * ---------------------------------------------------------------------------
- * |         BIND MOUNT OPERATION                                            |
- * |**************************************************************************
- * | source-->| shared        |       private  |       slave    | unbindable |
- * | dest     |               |                |                |            |
- * |   |      |               |                |                |            |
- * |   v      |               |                |                |            |
- * |**************************************************************************
- * |  shared  | shared (++)   |     shared (+) |     shared(+++)|  invalid   |
- * |          |               |                |                |            |
- * |non-shared| shared (+)    |      private   |      slave (*) |  invalid   |
- * ***************************************************************************
- * A bind operation clones the source mount and mounts the clone on the
- * destination mount.
- *
- * (++)  the cloned mount is propagated to all the mounts in the propagation
- * 	 tree of the destination mount and the cloned mount is added to
- * 	 the peer group of the source mount.
- * (+)   the cloned mount is created under the destination mount and is marked
- *       as shared. The cloned mount is added to the peer group of the source
- *       mount.
- * (+++) the mount is propagated to all the mounts in the propagation tree
- *       of the destination mount and the cloned mount is made slave
- *       of the same master as that of the source mount. The cloned mount
- *       is marked as 'shared and slave'.
- * (*)   the cloned mount is made a slave of the same master as that of the
- * 	 source mount.
- *
- * ---------------------------------------------------------------------------
- * |         		MOVE MOUNT OPERATION                                 |
- * |**************************************************************************
- * | source-->| shared        |       private  |       slave    | unbindable |
- * | dest     |               |                |                |            |
- * |   |      |               |                |                |            |
- * |   v      |               |                |                |            |
- * |**************************************************************************
- * |  shared  | shared (+)    |     shared (+) |    shared(+++) |  invalid   |
- * |          |               |                |                |            |
- * |non-shared| shared (+*)   |      private   |    slave (*)   | unbindable |
- * ***************************************************************************
- *
- * (+)  the mount is moved to the destination. And is then propagated to
- * 	all the mounts in the propagation tree of the destination mount.
- * (+*)  the mount is moved to the destination.
- * (+++)  the mount is moved to the destination and is then propagated to
- * 	all the mounts belonging to the destination mount's propagation tree.
- * 	the mount is marked as 'shared and slave'.
- * (*)	the mount continues to be a slave at the new location.
- *
- * if the source mount is a tree, the operations explained above is
- * applied to each mount in the tree.
- * Must be called without spinlocks held, since this function can sleep
- * in allocations.
- */
-static int attach_recursive_mnt(struct mount *source_mnt,
-			struct path *path, struct path *parent_path)
-{
-	LIST_HEAD(tree_list);
-	struct mount *dest_mnt = real_mount(path->mnt);
-	struct dentry *dest_dentry = path->dentry;
-	struct mount *child, *p;
-	int err;
-
-	if (IS_MNT_SHARED(dest_mnt)) {
-		err = invent_group_ids(source_mnt, true);
-		if (err)
-			goto out;
-	}
-	err = propagate_mnt(dest_mnt, dest_dentry, source_mnt, &tree_list);
-	if (err)
-		goto out_cleanup_ids;
-
-	br_write_lock(vfsmount_lock);
-
-	if (IS_MNT_SHARED(dest_mnt)) {
-		for (p = source_mnt; p; p = next_mnt(p, source_mnt))
-			set_mnt_shared(p);
-	}
-	if (parent_path) {
-		detach_mnt(source_mnt, parent_path);
-		attach_mnt(source_mnt, path);
-		touch_mnt_namespace(source_mnt->mnt_ns);
-	} else {
-		mnt_set_mountpoint(dest_mnt, dest_dentry, source_mnt);
-		commit_tree(source_mnt);
-	}
-
-	list_for_each_entry_safe(child, p, &tree_list, mnt_hash) {
-		list_del_init(&child->mnt_hash);
-		commit_tree(child);
-	}
-	br_write_unlock(vfsmount_lock);
-
-	return 0;
-
- out_cleanup_ids:
-	if (IS_MNT_SHARED(dest_mnt))
-		cleanup_group_ids(source_mnt, NULL);
- out:
-	return err;
-}
-
-static int lock_mount(struct path *path)
-{
-	struct vfsmount *mnt;
-retry:
-	mutex_lock(&path->dentry->d_inode->i_mutex);
-	if (unlikely(cant_mount(path->dentry))) {
-		mutex_unlock(&path->dentry->d_inode->i_mutex);
-		return -ENOENT;
-	}
-	down_write(&namespace_sem);
-	mnt = lookup_mnt(path);
-	if (likely(!mnt))
-		return 0;
-	up_write(&namespace_sem);
-	mutex_unlock(&path->dentry->d_inode->i_mutex);
-	path_put(path);
-	path->mnt = mnt;
-	path->dentry = dget(mnt->mnt_root);
-	goto retry;
-}
-
-static void unlock_mount(struct path *path)
-{
-	up_write(&namespace_sem);
-	mutex_unlock(&path->dentry->d_inode->i_mutex);
-}
-
-static int graft_tree(struct mount *mnt, struct path *path)
-{
-	if (mnt->mnt.mnt_sb->s_flags & MS_NOUSER)
-		return -EINVAL;
-
-	if (S_ISDIR(path->dentry->d_inode->i_mode) !=
-	      S_ISDIR(mnt->mnt.mnt_root->d_inode->i_mode))
-		return -ENOTDIR;
-
-	if (d_unlinked(path->dentry))
-		return -ENOENT;
-
-	return attach_recursive_mnt(mnt, path, NULL);
-}
-
-/*
- * Sanity check the flags to change_mnt_propagation.
- */
-
-static int flags_to_propagation_type(int flags)
-{
-	int type = flags & ~(MS_REC | MS_SILENT);
-
-	/* Fail if any non-propagation flags are set */
-	if (type & ~(MS_SHARED | MS_PRIVATE | MS_SLAVE | MS_UNBINDABLE))
-		return 0;
-	/* Only one propagation flag should be set */
-	if (!is_power_of_2(type))
-		return 0;
-	return type;
-}
-
-/*
- * recursively change the type of the mountpoint.
- */
-static int do_change_type(struct path *path, int flag)
-{
-	struct mount *m;
-	struct mount *mnt = real_mount(path->mnt);
-	int recurse = flag & MS_REC;
-	int type;
-	int err = 0;
-
-	if (!capable(CAP_SYS_ADMIN))
-		return -EPERM;
-
-	if (path->dentry != path->mnt->mnt_root)
-		return -EINVAL;
-
-	type = flags_to_propagation_type(flag);
-	if (!type)
-		return -EINVAL;
-
-	down_write(&namespace_sem);
-	if (type == MS_SHARED) {
-		err = invent_group_ids(mnt, recurse);
-		if (err)
-			goto out_unlock;
-	}
-
-	br_write_lock(vfsmount_lock);
-	for (m = mnt; m; m = (recurse ? next_mnt(m, mnt) : NULL))
-		change_mnt_propagation(m, type);
-	br_write_unlock(vfsmount_lock);
-
- out_unlock:
-	up_write(&namespace_sem);
-	return err;
-}
-
-/*
- * do loopback mount.
- */
-static int do_loopback(struct path *path, char *old_name,
-				int recurse)
-{
-	LIST_HEAD(umount_list);
-	struct path old_path;
-	struct mount *mnt = NULL, *old;
-	int err = mount_is_safe(path);
-	if (err)
-		return err;
-	if (!old_name || !*old_name)
-		return -EINVAL;
-	err = kern_path(old_name, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &old_path);
-	if (err)
-		return err;
-
-	err = lock_mount(path);
-	if (err)
-		goto out;
-
-	old = real_mount(old_path.mnt);
-
-	err = -EINVAL;
-	if (IS_MNT_UNBINDABLE(old))
-		goto out2;
-
-	if (!check_mnt(real_mount(path->mnt)) || !check_mnt(old))
-		goto out2;
-
-	err = -ENOMEM;
-	if (recurse)
-		mnt = copy_tree(old, old_path.dentry, 0);
-	else
-		mnt = clone_mnt(old, old_path.dentry, 0);
-
-	if (!mnt)
-		goto out2;
-
-	err = graft_tree(mnt, path);
-	if (err) {
-		br_write_lock(vfsmount_lock);
-		umount_tree(mnt, 0, &umount_list);
-		br_write_unlock(vfsmount_lock);
-	}
-out2:
-	unlock_mount(path);
-	release_mounts(&umount_list);
-out:
-	path_put(&old_path);
-	return err;
-}
-
-static int change_mount_flags(struct vfsmount *mnt, int ms_flags)
-{
-	int error = 0;
-	int readonly_request = 0;
-
-	if (ms_flags & MS_RDONLY)
-		readonly_request = 1;
-	if (readonly_request == __mnt_is_readonly(mnt))
-		return 0;
-
-	if (readonly_request)
-		error = mnt_make_readonly(real_mount(mnt));
-	else
-		__mnt_unmake_readonly(real_mount(mnt));
-	return error;
-}
-
-/*
- * change filesystem flags. dir should be a physical root of filesystem.
- * If you've mounted a non-root directory somewhere and want to do remount
- * on it - tough luck.
- */
-static int do_remount(struct path *path, int flags, int mnt_flags,
-		      void *data)
-{
-	int err;
-	struct super_block *sb = path->mnt->mnt_sb;
-	struct mount *mnt = real_mount(path->mnt);
-
-	if (!capable(CAP_SYS_ADMIN))
-		return -EPERM;
-
-	if (!check_mnt(mnt))
-		return -EINVAL;
-
-	if (path->dentry != path->mnt->mnt_root)
-		return -EINVAL;
-
-	err = security_sb_remount(sb, data);
-	if (err)
-		return err;
-
-	down_write(&sb->s_umount);
-	if (flags & MS_BIND)
-		err = change_mount_flags(path->mnt, flags);
-	else
-		err = do_remount_sb(sb, flags, data, 0);
-	if (!err) {
-		br_write_lock(vfsmount_lock);
-		mnt_flags |= mnt->mnt.mnt_flags & MNT_PROPAGATION_MASK;
-		mnt->mnt.mnt_flags = mnt_flags;
-		br_write_unlock(vfsmount_lock);
-	}
-	up_write(&sb->s_umount);
-	if (!err) {
-		br_write_lock(vfsmount_lock);
-		touch_mnt_namespace(mnt->mnt_ns);
-		br_write_unlock(vfsmount_lock);
-	}
-	return err;
-}
-
-static inline int tree_contains_unbindable(struct mount *mnt)
-{
-	struct mount *p;
-	for (p = mnt; p; p = next_mnt(p, mnt)) {
-		if (IS_MNT_UNBINDABLE(p))
-			return 1;
-	}
-	return 0;
-}
-
-static int do_move_mount(struct path *path, char *old_name)
-{
-	struct path old_path, parent_path;
-	struct mount *p;
-	struct mount *old;
-	int err = 0;
-	if (!capable(CAP_SYS_ADMIN))
-		return -EPERM;
-	if (!old_name || !*old_name)
-		return -EINVAL;
-	err = kern_path(old_name, LOOKUP_FOLLOW, &old_path);
-	if (err)
-		return err;
-
-	err = lock_mount(path);
-	if (err < 0)
-		goto out;
-
-	old = real_mount(old_path.mnt);
-	p = real_mount(path->mnt);
-
-	err = -EINVAL;
-	if (!check_mnt(p) || !check_mnt(old))
-		goto out1;
-
-	if (d_unlinked(path->dentry))
-		goto out1;
-
-	err = -EINVAL;
-	if (old_path.dentry != old_path.mnt->mnt_root)
-		goto out1;
-
-	if (!mnt_has_parent(old))
-		goto out1;
-
-	if (S_ISDIR(path->dentry->d_inode->i_mode) !=
-	      S_ISDIR(old_path.dentry->d_inode->i_mode))
-		goto out1;
-	/*
-	 * Don't move a mount residing in a shared parent.
-	 */
-	if (IS_MNT_SHARED(old->mnt_parent))
-		goto out1;
-	/*
-	 * Don't move a mount tree containing unbindable mounts to a destination
-	 * mount which is shared.
-	 */
-	if (IS_MNT_SHARED(p) && tree_contains_unbindable(old))
-		goto out1;
-	err = -ELOOP;
-	for (; mnt_has_parent(p); p = p->mnt_parent)
-		if (p == old)
-			goto out1;
-
-	err = attach_recursive_mnt(old, path, &parent_path);
-	if (err)
-		goto out1;
-
-	/* if the mount is moved, it should no longer be expire
-	 * automatically */
-	list_del_init(&old->mnt_expire);
-out1:
-	unlock_mount(path);
-out:
-	if (!err)
-		path_put(&parent_path);
-	path_put(&old_path);
-	return err;
-}
-
-static struct vfsmount *fs_set_subtype(struct vfsmount *mnt, const char *fstype)
-{
-	int err;
-	const char *subtype = strchr(fstype, '.');
-	if (subtype) {
-		subtype++;
-		err = -EINVAL;
-		if (!subtype[0])
-			goto err;
-	} else
-		subtype = "";
-
-	mnt->mnt_sb->s_subtype = kstrdup(subtype, GFP_KERNEL);
-	err = -ENOMEM;
-	if (!mnt->mnt_sb->s_subtype)
-		goto err;
-	return mnt;
-
- err:
-	mntput(mnt);
-	return ERR_PTR(err);
-}
-
-static struct vfsmount *
-do_kern_mount(const char *fstype, int flags, const char *name, void *data)
-{
-	struct file_system_type *type = get_fs_type(fstype);
-	struct vfsmount *mnt;
-	if (!type)
-		return ERR_PTR(-ENODEV);
-	mnt = vfs_kern_mount(type, flags, name, data);
-	if (!IS_ERR(mnt) && (type->fs_flags & FS_HAS_SUBTYPE) &&
-	    !mnt->mnt_sb->s_subtype)
-		mnt = fs_set_subtype(mnt, fstype);
-	put_filesystem(type);
-	return mnt;
-}
-
-/*
- * add a mount into a namespace's mount tree
- */
-static int do_add_mount(struct mount *newmnt, struct path *path, int mnt_flags)
-{
-	int err;
-
-	mnt_flags &= ~(MNT_SHARED | MNT_WRITE_HOLD | MNT_INTERNAL);
-
-	err = lock_mount(path);
-	if (err)
-		return err;
-
-	err = -EINVAL;
-	if (!(mnt_flags & MNT_SHRINKABLE) && !check_mnt(real_mount(path->mnt)))
-		goto unlock;
-
-	/* Refuse the same filesystem on the same mount point */
-	err = -EBUSY;
-	if (path->mnt->mnt_sb == newmnt->mnt.mnt_sb &&
-	    path->mnt->mnt_root == path->dentry)
-		goto unlock;
-
-	err = -EINVAL;
-	if (S_ISLNK(newmnt->mnt.mnt_root->d_inode->i_mode))
-		goto unlock;
-
-	newmnt->mnt.mnt_flags = mnt_flags;
-	err = graft_tree(newmnt, path);
-
-unlock:
-	unlock_mount(path);
-	return err;
-}
-
-/*
- * create a new mount for userspace and request it to be added into the
- * namespace's tree
- */
-static int do_new_mount(struct path *path, char *type, int flags,
-			int mnt_flags, char *name, void *data)
-{
-	struct vfsmount *mnt;
-	int err;
-
-	if (!type)
-		return -EINVAL;
-
-	/* we need capabilities... */
-	if (!capable(CAP_SYS_ADMIN))
-		return -EPERM;
-
-	mnt = do_kern_mount(type, flags, name, data);
-	if (IS_ERR(mnt))
-		return PTR_ERR(mnt);
-
-	err = do_add_mount(real_mount(mnt), path, mnt_flags);
-	if (err)
-		mntput(mnt);
-	return err;
-}
-
-int finish_automount(struct vfsmount *m, struct path *path)
-{
-	struct mount *mnt = real_mount(m);
-	int err;
-	/* The new mount record should have at least 2 refs to prevent it being
-	 * expired before we get a chance to add it
-	 */
-	BUG_ON(mnt_get_count(mnt) < 2);
-
-	if (m->mnt_sb == path->mnt->mnt_sb &&
-	    m->mnt_root == path->dentry) {
-		err = -ELOOP;
-		goto fail;
-	}
-
-	err = do_add_mount(mnt, path, path->mnt->mnt_flags | MNT_SHRINKABLE);
-	if (!err)
-		return 0;
-fail:
-	/* remove m from any expiration list it may be on */
-	if (!list_empty(&mnt->mnt_expire)) {
-		down_write(&namespace_sem);
-		br_write_lock(vfsmount_lock);
-		list_del_init(&mnt->mnt_expire);
-		br_write_unlock(vfsmount_lock);
-		up_write(&namespace_sem);
-	}
-	mntput(m);
-	mntput(m);
-	return err;
-}
-
-/**
- * mnt_set_expiry - Put a mount on an expiration list
- * @mnt: The mount to list.
- * @expiry_list: The list to add the mount to.
- */
-void mnt_set_expiry(struct vfsmount *mnt, struct list_head *expiry_list)
-{
-	down_write(&namespace_sem);
-	br_write_lock(vfsmount_lock);
-
-	list_add_tail(&real_mount(mnt)->mnt_expire, expiry_list);
-
-	br_write_unlock(vfsmount_lock);
-	up_write(&namespace_sem);
-}
-EXPORT_SYMBOL(mnt_set_expiry);
-
-/*
- * process a list of expirable mountpoints with the intent of discarding any
- * mountpoints that aren't in use and haven't been touched since last we came
- * here
- */
-void mark_mounts_for_expiry(struct list_head *mounts)
-{
-	struct mount *mnt, *next;
-	LIST_HEAD(graveyard);
-	LIST_HEAD(umounts);
-
-	if (list_empty(mounts))
-		return;
-
-	down_write(&namespace_sem);
-	br_write_lock(vfsmount_lock);
-
-	/* extract from the expiration list every vfsmount that matches the
-	 * following criteria:
-	 * - only referenced by its parent vfsmount
-	 * - still marked for expiry (marked on the last call here; marks are
-	 *   cleared by mntput())
-	 */
-	list_for_each_entry_safe(mnt, next, mounts, mnt_expire) {
-		if (!xchg(&mnt->mnt_expiry_mark, 1) ||
-			propagate_mount_busy(mnt, 1))
-			continue;
-		list_move(&mnt->mnt_expire, &graveyard);
-	}
-	while (!list_empty(&graveyard)) {
-		mnt = list_first_entry(&graveyard, struct mount, mnt_expire);
-		touch_mnt_namespace(mnt->mnt_ns);
-		umount_tree(mnt, 1, &umounts);
-	}
-	br_write_unlock(vfsmount_lock);
-	up_write(&namespace_sem);
-
-	release_mounts(&umounts);
-}
-
-EXPORT_SYMBOL_GPL(mark_mounts_for_expiry);
-
-/*
- * Ripoff of 'select_parent()'
- *
- * search the list of submounts for a given mountpoint, and move any
- * shrinkable submounts to the 'graveyard' list.
- */
-static int select_submounts(struct mount *parent, struct list_head *graveyard)
-{
-	struct mount *this_parent = parent;
-	struct list_head *next;
-	int found = 0;
-
-repeat:
-	next = this_parent->mnt_mounts.next;
-resume:
-	while (next != &this_parent->mnt_mounts) {
-		struct list_head *tmp = next;
-		struct mount *mnt = list_entry(tmp, struct mount, mnt_child);
-
-		next = tmp->next;
-		if (!(mnt->mnt.mnt_flags & MNT_SHRINKABLE))
-			continue;
-		/*
-		 * Descend a level if the d_mounts list is non-empty.
-		 */
-		if (!list_empty(&mnt->mnt_mounts)) {
-			this_parent = mnt;
-			goto repeat;
-		}
-
-		if (!propagate_mount_busy(mnt, 1)) {
-			list_move_tail(&mnt->mnt_expire, graveyard);
-			found++;
-		}
-	}
-	/*
-	 * All done at this level ... ascend and resume the search
-	 */
-	if (this_parent != parent) {
-		next = this_parent->mnt_child.next;
-		this_parent = this_parent->mnt_parent;
-		goto resume;
-	}
-	return found;
-}
-
-/*
- * process a list of expirable mountpoints with the intent of discarding any
- * submounts of a specific parent mountpoint
- *
- * vfsmount_lock must be held for write
- */
-static void shrink_submounts(struct mount *mnt, struct list_head *umounts)
-{
-	LIST_HEAD(graveyard);
-	struct mount *m;
-
-	/* extract submounts of 'mountpoint' from the expiration list */
-	while (select_submounts(mnt, &graveyard)) {
-		while (!list_empty(&graveyard)) {
-			m = list_first_entry(&graveyard, struct mount,
-						mnt_expire);
-			touch_mnt_namespace(m->mnt_ns);
-			umount_tree(m, 1, umounts);
-		}
-	}
-}
-
-/*
- * Some copy_from_user() implementations do not return the exact number of
- * bytes remaining to copy on a fault.  But copy_mount_options() requires that.
- * Note that this function differs from copy_from_user() in that it will oops
- * on bad values of `to', rather than returning a short copy.
- */
-static long exact_copy_from_user(void *to, const void __user * from,
-				 unsigned long n)
-{
-	char *t = to;
-	const char __user *f = from;
-	char c;
-
-	if (!access_ok(VERIFY_READ, from, n))
-		return n;
-
-	while (n) {
-		if (__get_user(c, f)) {
-			memset(t, 0, n);
-			break;
-		}
-		*t++ = c;
-		f++;
-		n--;
-	}
-	return n;
-}
-
-int copy_mount_options(const void __user * data, unsigned long *where)
-{
-	int i;
-	unsigned long page;
-	unsigned long size;
-
-	*where = 0;
-	if (!data)
-		return 0;
-
-	if (!(page = __get_free_page(GFP_KERNEL)))
-		return -ENOMEM;
-
-	/* We only care that *some* data at the address the user
-	 * gave us is valid.  Just in case, we'll zero
-	 * the remainder of the page.
-	 */
-	/* copy_from_user cannot cross TASK_SIZE ! */
-	size = TASK_SIZE - (unsigned long)data;
-	if (size > PAGE_SIZE)
-		size = PAGE_SIZE;
-
-	i = size - exact_copy_from_user((void *)page, data, size);
-	if (!i) {
-		free_page(page);
-		return -EFAULT;
-	}
-	if (i != PAGE_SIZE)
-		memset((char *)page + i, 0, PAGE_SIZE - i);
-	*where = page;
-	return 0;
-}
-
-int copy_mount_string(const void __user *data, char **where)
-{
-	char *tmp;
-
-	if (!data) {
-		*where = NULL;
-		return 0;
-	}
-
-	tmp = strndup_user(data, PAGE_SIZE);
-	if (IS_ERR(tmp))
-		return PTR_ERR(tmp);
-
-	*where = tmp;
-	return 0;
-}
-
-/*
- * Flags is a 32-bit value that allows up to 31 non-fs dependent flags to
- * be given to the mount() call (ie: read-only, no-dev, no-suid etc).
- *
- * data is a (void *) that can point to any structure up to
- * PAGE_SIZE-1 bytes, which can contain arbitrary fs-dependent
- * information (or be NULL).
- *
- * Pre-0.97 versions of mount() didn't have a flags word.
- * When the flags word was introduced its top half was required
- * to have the magic value 0xC0ED, and this remained so until 2.4.0-test9.
- * Therefore, if this magic number is present, it carries no information
- * and must be discarded.
- */
-long do_mount(char *dev_name, char *dir_name, char *type_page,
-		  unsigned long flags, void *data_page)
-{
-	struct path path;
-	int retval = 0;
-	int mnt_flags = 0;
-
-	/* Discard magic */
-	if ((flags & MS_MGC_MSK) == MS_MGC_VAL)
-		flags &= ~MS_MGC_MSK;
-
-	/* Basic sanity checks */
-
-	if (!dir_name || !*dir_name || !memchr(dir_name, 0, PAGE_SIZE))
-		return -EINVAL;
-
-	if (data_page)
-		((char *)data_page)[PAGE_SIZE - 1] = 0;
-
-	/* ... and get the mountpoint */
-	retval = kern_path(dir_name, LOOKUP_FOLLOW, &path);
-	if (retval)
-		return retval;
-
-	retval = security_sb_mount(dev_name, &path,
-				   type_page, flags, data_page);
-	if (retval)
-		goto dput_out;
-
-	/* Default to relatime unless overriden */
-	if (!(flags & MS_NOATIME))
-		mnt_flags |= MNT_RELATIME;
-
-	/* Separate the per-mountpoint flags */
-	if (flags & MS_NOSUID)
-		mnt_flags |= MNT_NOSUID;
-	if (flags & MS_NODEV)
-		mnt_flags |= MNT_NODEV;
-	if (flags & MS_NOEXEC)
-		mnt_flags |= MNT_NOEXEC;
-	if (flags & MS_NOATIME)
-		mnt_flags |= MNT_NOATIME;
-	if (flags & MS_NODIRATIME)
-		mnt_flags |= MNT_NODIRATIME;
-	if (flags & MS_STRICTATIME)
-		mnt_flags &= ~(MNT_RELATIME | MNT_NOATIME);
-	if (flags & MS_RDONLY)
-		mnt_flags |= MNT_READONLY;
-
-	flags &= ~(MS_NOSUID | MS_NOEXEC | MS_NODEV | MS_ACTIVE | MS_BORN |
-		   MS_NOATIME | MS_NODIRATIME | MS_RELATIME| MS_KERNMOUNT |
-		   MS_STRICTATIME);
-
-	if (flags & MS_REMOUNT)
-		retval = do_remount(&path, flags & ~MS_REMOUNT, mnt_flags,
-				    data_page);
-	else if (flags & MS_BIND)
-		retval = do_loopback(&path, dev_name, flags & MS_REC);
-	else if (flags & (MS_SHARED | MS_PRIVATE | MS_SLAVE | MS_UNBINDABLE))
-		retval = do_change_type(&path, flags);
-	else if (flags & MS_MOVE)
-		retval = do_move_mount(&path, dev_name);
-	else
-		retval = do_new_mount(&path, type_page, flags, mnt_flags,
-				      dev_name, data_page);
-dput_out:
-	path_put(&path);
-	return retval;
-}
-
-static struct mnt_namespace *alloc_mnt_ns(void)
-{
-	struct mnt_namespace *new_ns;
-
-	new_ns = kmalloc(sizeof(struct mnt_namespace), GFP_KERNEL);
-	if (!new_ns)
-		return ERR_PTR(-ENOMEM);
-	atomic_set(&new_ns->count, 1);
-	new_ns->root = NULL;
-	INIT_LIST_HEAD(&new_ns->list);
-	init_waitqueue_head(&new_ns->poll);
-	new_ns->event = 0;
-	return new_ns;
-}
-
-void mnt_make_longterm(struct vfsmount *mnt)
-{
-	__mnt_make_longterm(real_mount(mnt));
-}
-
-void mnt_make_shortterm(struct vfsmount *m)
-{
-#ifdef CONFIG_SMP
-	struct mount *mnt = real_mount(m);
-	if (atomic_add_unless(&mnt->mnt_longterm, -1, 1))
-		return;
-	br_write_lock(vfsmount_lock);
-	atomic_dec(&mnt->mnt_longterm);
-	br_write_unlock(vfsmount_lock);
-#endif
-}
-
-/*
- * Allocate a new namespace structure and populate it with contents
- * copied from the namespace of the passed in task structure.
- */
-static struct mnt_namespace *dup_mnt_ns(struct mnt_namespace *mnt_ns,
-		struct fs_struct *fs)
-{
-	struct mnt_namespace *new_ns;
-	struct vfsmount *rootmnt = NULL, *pwdmnt = NULL;
-	struct mount *p, *q;
-	struct mount *old = mnt_ns->root;
-	struct mount *new;
-
-	new_ns = alloc_mnt_ns();
-	if (IS_ERR(new_ns))
-		return new_ns;
-
-	down_write(&namespace_sem);
-	/* First pass: copy the tree topology */
-	new = copy_tree(old, old->mnt.mnt_root, CL_COPY_ALL | CL_EXPIRE);
-	if (!new) {
-		up_write(&namespace_sem);
-		kfree(new_ns);
-		return ERR_PTR(-ENOMEM);
-	}
-	new_ns->root = new;
-	br_write_lock(vfsmount_lock);
-	list_add_tail(&new_ns->list, &new->mnt_list);
-	br_write_unlock(vfsmount_lock);
-
-	/*
-	 * Second pass: switch the tsk->fs->* elements and mark new vfsmounts
-	 * as belonging to new namespace.  We have already acquired a private
-	 * fs_struct, so tsk->fs->lock is not needed.
-	 */
-	p = old;
-	q = new;
-	while (p) {
-		q->mnt_ns = new_ns;
-		__mnt_make_longterm(q);
-		if (fs) {
-			if (&p->mnt == fs->root.mnt) {
-				fs->root.mnt = mntget(&q->mnt);
-				__mnt_make_longterm(q);
-				mnt_make_shortterm(&p->mnt);
-				rootmnt = &p->mnt;
-			}
-			if (&p->mnt == fs->pwd.mnt) {
-				fs->pwd.mnt = mntget(&q->mnt);
-				__mnt_make_longterm(q);
-				mnt_make_shortterm(&p->mnt);
-				pwdmnt = &p->mnt;
-			}
-		}
-		p = next_mnt(p, old);
-		q = next_mnt(q, new);
-	}
-	up_write(&namespace_sem);
-
-	if (rootmnt)
-		mntput(rootmnt);
-	if (pwdmnt)
-		mntput(pwdmnt);
-
-	return new_ns;
-}
-
-struct mnt_namespace *copy_mnt_ns(unsigned long flags, struct mnt_namespace *ns,
-		struct fs_struct *new_fs)
-{
-	struct mnt_namespace *new_ns;
-
-	BUG_ON(!ns);
-	get_mnt_ns(ns);
-
-	if (!(flags & CLONE_NEWNS))
-		return ns;
-
-	new_ns = dup_mnt_ns(ns, new_fs);
-
-	put_mnt_ns(ns);
-	return new_ns;
-}
-
-/**
- * create_mnt_ns - creates a private namespace and adds a root filesystem
- * @mnt: pointer to the new root filesystem mountpoint
- */
-static struct mnt_namespace *create_mnt_ns(struct vfsmount *m)
-{
-	struct mnt_namespace *new_ns = alloc_mnt_ns();
-	if (!IS_ERR(new_ns)) {
-		struct mount *mnt = real_mount(m);
-		mnt->mnt_ns = new_ns;
-		__mnt_make_longterm(mnt);
-		new_ns->root = mnt;
-		list_add(&new_ns->list, &mnt->mnt_list);
-	} else {
-		mntput(m);
-	}
-	return new_ns;
-}
-
-struct dentry *mount_subtree(struct vfsmount *mnt, const char *name)
-{
-	struct mnt_namespace *ns;
-	struct super_block *s;
-	struct path path;
-	int err;
-
-	ns = create_mnt_ns(mnt);
-	if (IS_ERR(ns))
-		return ERR_CAST(ns);
-
-	err = vfs_path_lookup(mnt->mnt_root, mnt,
-			name, LOOKUP_FOLLOW|LOOKUP_AUTOMOUNT, &path);
-
-	put_mnt_ns(ns);
-
-	if (err)
-		return ERR_PTR(err);
-
-	/* trade a vfsmount reference for active sb one */
-	s = path.mnt->mnt_sb;
-	atomic_inc(&s->s_active);
-	mntput(path.mnt);
-	/* lock the sucker */
-	down_write(&s->s_umount);
-	/* ... and return the root of (sub)tree on it */
-	return path.dentry;
-}
-EXPORT_SYMBOL(mount_subtree);
-
-SYSCALL_DEFINE5(mount, char __user *, dev_name, char __user *, dir_name,
-		char __user *, type, unsigned long, flags, void __user *, data)
-{
-	int ret;
-	char *kernel_type;
-	char *kernel_dir;
-	char *kernel_dev;
-	unsigned long data_page;
-
-	ret = copy_mount_string(type, &kernel_type);
-	if (ret < 0)
-		goto out_type;
-
-	kernel_dir = getname(dir_name);
-	if (IS_ERR(kernel_dir)) {
-		ret = PTR_ERR(kernel_dir);
-		goto out_dir;
-	}
-
-	ret = copy_mount_string(dev_name, &kernel_dev);
-	if (ret < 0)
-		goto out_dev;
-
-	ret = copy_mount_options(data, &data_page);
-	if (ret < 0)
-		goto out_data;
-
-	ret = do_mount(kernel_dev, kernel_dir, kernel_type, flags,
-		(void *) data_page);
-
-	free_page(data_page);
-out_data:
-	kfree(kernel_dev);
-out_dev:
-	putname(kernel_dir);
-out_dir:
-	kfree(kernel_type);
-out_type:
-	return ret;
-}
-
-/*
- * Return true if path is reachable from root
- *
- * namespace_sem or vfsmount_lock is held
- */
-bool is_path_reachable(struct mount *mnt, struct dentry *dentry,
-			 const struct path *root)
-{
-	while (&mnt->mnt != root->mnt && mnt_has_parent(mnt)) {
-		dentry = mnt->mnt_mountpoint;
-		mnt = mnt->mnt_parent;
-	}
-	return &mnt->mnt == root->mnt && is_subdir(dentry, root->dentry);
-}
-
-int path_is_under(struct path *path1, struct path *path2)
-{
-	int res;
-	br_read_lock(vfsmount_lock);
-	res = is_path_reachable(real_mount(path1->mnt), path1->dentry, path2);
-	br_read_unlock(vfsmount_lock);
-	return res;
-}
-EXPORT_SYMBOL(path_is_under);
-
-/*
- * pivot_root Semantics:
- * Moves the root file system of the current process to the directory put_old,
- * makes new_root as the new root file system of the current process, and sets
- * root/cwd of all processes which had them on the current root to new_root.
- *
- * Restrictions:
- * The new_root and put_old must be directories, and  must not be on the
- * same file  system as the current process root. The put_old  must  be
- * underneath new_root,  i.e. adding a non-zero number of /.. to the string
- * pointed to by put_old must yield the same directory as new_root. No other
- * file system may be mounted on put_old. After all, new_root is a mountpoint.
- *
- * Also, the current root cannot be on the 'rootfs' (initial ramfs) filesystem.
- * See Documentation/filesystems/ramfs-rootfs-initramfs.txt for alternatives
- * in this situation.
- *
- * Notes:
- *  - we don't move root/cwd if they are not at the root (reason: if something
- *    cared enough to change them, it's probably wrong to force them elsewhere)
- *  - it's okay to pick a root that isn't the root of a file system, e.g.
- *    /nfs/my_root where /nfs is the mount point. It must be a mountpoint,
- *    though, so you may need to say mount --bind /nfs/my_root /nfs/my_root
- *    first.
- */
-SYSCALL_DEFINE2(pivot_root, const char __user *, new_root,
-		const char __user *, put_old)
-{
-	struct path new, old, parent_path, root_parent, root;
-	struct mount *new_mnt, *root_mnt;
-	int error;
-
-	if (!capable(CAP_SYS_ADMIN))
-		return -EPERM;
-
-	error = user_path_dir(new_root, &new);
-	if (error)
-		goto out0;
-
-	error = user_path_dir(put_old, &old);
-	if (error)
-		goto out1;
-
-	error = security_sb_pivotroot(&old, &new);
-	if (error)
-		goto out2;
-
-	get_fs_root(current->fs, &root);
-	error = lock_mount(&old);
-	if (error)
-		goto out3;
-
-	error = -EINVAL;
-	new_mnt = real_mount(new.mnt);
-	root_mnt = real_mount(root.mnt);
-	if (IS_MNT_SHARED(real_mount(old.mnt)) ||
-		IS_MNT_SHARED(new_mnt->mnt_parent) ||
-		IS_MNT_SHARED(root_mnt->mnt_parent))
-		goto out4;
-	if (!check_mnt(root_mnt) || !check_mnt(new_mnt))
-		goto out4;
-	error = -ENOENT;
-	if (d_unlinked(new.dentry))
-		goto out4;
-	if (d_unlinked(old.dentry))
-		goto out4;
-	error = -EBUSY;
-	if (new.mnt == root.mnt ||
-	    old.mnt == root.mnt)
-		goto out4; /* loop, on the same file system  */
-	error = -EINVAL;
-	if (root.mnt->mnt_root != root.dentry)
-		goto out4; /* not a mountpoint */
-	if (!mnt_has_parent(root_mnt))
-		goto out4; /* not attached */
-	if (new.mnt->mnt_root != new.dentry)
-		goto out4; /* not a mountpoint */
-	if (!mnt_has_parent(new_mnt))
-		goto out4; /* not attached */
-	/* make sure we can reach put_old from new_root */
-	if (!is_path_reachable(real_mount(old.mnt), old.dentry, &new))
-		goto out4;
-	br_write_lock(vfsmount_lock);
-	detach_mnt(new_mnt, &parent_path);
-	detach_mnt(root_mnt, &root_parent);
-	/* mount old root on put_old */
-	attach_mnt(root_mnt, &old);
-	/* mount new_root on / */
-	attach_mnt(new_mnt, &root_parent);
-	touch_mnt_namespace(current->nsproxy->mnt_ns);
-	br_write_unlock(vfsmount_lock);
-	chroot_fs_refs(&root, &new);
-	error = 0;
-out4:
-	unlock_mount(&old);
-	if (!error) {
-		path_put(&root_parent);
-		path_put(&parent_path);
-	}
-out3:
-	path_put(&root);
-out2:
-	path_put(&old);
-out1:
-	path_put(&new);
-out0:
-	return error;
-}
-
-static void __init init_mount_tree(void)
-{
-	struct vfsmount *mnt;
-	struct mnt_namespace *ns;
-	struct path root;
-
-	mnt = do_kern_mount("rootfs", 0, "rootfs", NULL);
-	if (IS_ERR(mnt))
-		panic("Can't create rootfs");
-
-	ns = create_mnt_ns(mnt);
-	if (IS_ERR(ns))
-		panic("Can't allocate initial namespace");
-
-	init_task.nsproxy->mnt_ns = ns;
-	get_mnt_ns(ns);
-
-	root.mnt = mnt;
-	root.dentry = mnt->mnt_root;
-
-	set_fs_pwd(current->fs, &root);
-	set_fs_root(current->fs, &root);
-}
-
-void __init mnt_init(void)
-{
-	unsigned u;
-	int err;
-
-	init_rwsem(&namespace_sem);
-
-	mnt_cache = kmem_cache_create("mnt_cache", sizeof(struct mount),
-			0, SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL);
-
-	mount_hashtable = (struct list_head *)__get_free_page(GFP_ATOMIC);
-
-	if (!mount_hashtable)
-		panic("Failed to allocate mount hash table\n");
-
-	printk(KERN_INFO "Mount-cache hash table entries: %lu\n", HASH_SIZE);
-
-	for (u = 0; u < HASH_SIZE; u++)
-		INIT_LIST_HEAD(&mount_hashtable[u]);
-
-	br_lock_init(vfsmount_lock);
-
-	err = sysfs_init();
-	if (err)
-		printk(KERN_WARNING "%s: sysfs_init error: %d\n",
-			__func__, err);
-	fs_kobj = kobject_create_and_add("fs", NULL);
-	if (!fs_kobj)
-		printk(KERN_WARNING "%s: kobj create error\n", __func__);
-	init_rootfs();
-	init_mount_tree();
-}
-
-void put_mnt_ns(struct mnt_namespace *ns)
-{
-	LIST_HEAD(umount_list);
-
-	if (!atomic_dec_and_test(&ns->count))
-		return;
-	down_write(&namespace_sem);
-	br_write_lock(vfsmount_lock);
-	umount_tree(ns->root, 0, &umount_list);
-	br_write_unlock(vfsmount_lock);
-	up_write(&namespace_sem);
-	release_mounts(&umount_list);
-	kfree(ns);
-}
-
-struct vfsmount *kern_mount_data(struct file_system_type *type, void *data)
-{
-	struct vfsmount *mnt;
-	mnt = vfs_kern_mount(type, MS_KERNMOUNT, type->name, data);
-	if (!IS_ERR(mnt)) {
-		/*
-		 * it is a longterm mount, don't release mnt until
-		 * we unmount before file sys is unregistered
-		*/
-		mnt_make_longterm(mnt);
-	}
-	return mnt;
-}
-EXPORT_SYMBOL_GPL(kern_mount_data);
-
-void kern_unmount(struct vfsmount *mnt)
-{
-	/* release long term mount so mount point can be released */
-	if (!IS_ERR_OR_NULL(mnt)) {
-		mnt_make_shortterm(mnt);
-		mntput(mnt);
-	}
-}
-EXPORT_SYMBOL(kern_unmount);
-
-bool our_mnt(struct vfsmount *mnt)
-{
-	return check_mnt(real_mount(mnt));
-}