X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=fs%2Fnamespace.c;h=1e56303c718e9094ccc316da858c4f4cc2f160b4;hb=3e93cd671813e204c258f1e6c797959920cf7772;hp=f30b11e2240e170e8d6dfe7fd6a395e02344f212;hpb=5c752ad9f35910ff1912b3f3ae82878178ddc432;p=safe%2Fjmp%2Flinux-2.6

diff --git a/fs/namespace.c b/fs/namespace.c
index f30b11e..1e56303 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -112,9 +112,13 @@ struct vfsmount *alloc_vfsmnt(const char *name)
 		int err;
 
 		err = mnt_alloc_id(mnt);
-		if (err) {
-			kmem_cache_free(mnt_cache, mnt);
-			return NULL;
+		if (err)
+			goto out_free_cache;
+
+		if (name) {
+			mnt->mnt_devname = kstrdup(name, GFP_KERNEL);
+			if (!mnt->mnt_devname)
+				goto out_free_id;
 		}
 
 		atomic_set(&mnt->mnt_count, 1);
@@ -127,16 +131,14 @@ struct vfsmount *alloc_vfsmnt(const char *name)
 		INIT_LIST_HEAD(&mnt->mnt_slave_list);
 		INIT_LIST_HEAD(&mnt->mnt_slave);
 		atomic_set(&mnt->__mnt_writers, 0);
-		if (name) {
-			int size = strlen(name) + 1;
-			char *newname = kmalloc(size, GFP_KERNEL);
-			if (newname) {
-				memcpy(newname, name, size);
-				mnt->mnt_devname = newname;
-			}
-		}
 	}
 	return mnt;
+
+out_free_id:
+	mnt_free_id(mnt);
+out_free_cache:
+	kmem_cache_free(mnt_cache, mnt);
+	return NULL;
 }
 
 /*
@@ -395,11 +397,10 @@ static void __mnt_unmake_readonly(struct vfsmount *mnt)
 	spin_unlock(&vfsmount_lock);
 }
 
-int simple_set_mnt(struct vfsmount *mnt, struct super_block *sb)
+void simple_set_mnt(struct vfsmount *mnt, struct super_block *sb)
 {
 	mnt->mnt_sb = sb;
 	mnt->mnt_root = dget(sb->s_root);
-	return 0;
 }
 
 EXPORT_SYMBOL(simple_set_mnt);
@@ -612,9 +613,11 @@ static inline void __mntput(struct vfsmount *mnt)
 	 */
 	for_each_possible_cpu(cpu) {
 		struct mnt_writer *cpu_writer = &per_cpu(mnt_writers, cpu);
-		if (cpu_writer->mnt != mnt)
-			continue;
 		spin_lock(&cpu_writer->lock);
+		if (cpu_writer->mnt != mnt) {
+			spin_unlock(&cpu_writer->lock);
+			continue;
+		}
 		atomic_add(cpu_writer->count, &mnt->__mnt_writers);
 		cpu_writer->count = 0;
 		/*
@@ -776,6 +779,7 @@ static void show_mnt_opts(struct seq_file *m, struct vfsmount *mnt)
 		{ MNT_NOATIME, ",noatime" },
 		{ MNT_NODIRATIME, ",nodiratime" },
 		{ MNT_RELATIME, ",relatime" },
+		{ MNT_STRICTATIME, ",strictatime" },
 		{ 0, NULL }
 	};
 	const struct proc_fs_info *fs_infop;
@@ -1126,29 +1130,29 @@ static int do_umount(struct vfsmount *mnt, int flags)
  * unixes. Our API is identical to OSF/1 to avoid making a mess of AMD
  */
 
-asmlinkage long sys_umount(char __user * name, int flags)
+SYSCALL_DEFINE2(umount, char __user *, name, int, flags)
 {
-	struct nameidata nd;
+	struct path path;
 	int retval;
 
-	retval = __user_walk(name, LOOKUP_FOLLOW, &nd);
+	retval = user_path(name, &path);
 	if (retval)
 		goto out;
 	retval = -EINVAL;
-	if (nd.path.dentry != nd.path.mnt->mnt_root)
+	if (path.dentry != path.mnt->mnt_root)
 		goto dput_and_out;
-	if (!check_mnt(nd.path.mnt))
+	if (!check_mnt(path.mnt))
 		goto dput_and_out;
 
 	retval = -EPERM;
 	if (!capable(CAP_SYS_ADMIN))
 		goto dput_and_out;
 
-	retval = do_umount(nd.path.mnt, flags);
+	retval = do_umount(path.mnt, flags);
 dput_and_out:
 	/* we mustn't call path_put() as that would clear mnt_expiry_mark */
-	dput(nd.path.dentry);
-	mntput_no_expire(nd.path.mnt);
+	dput(path.dentry);
+	mntput_no_expire(path.mnt);
 out:
 	return retval;
 }
@@ -1158,26 +1162,26 @@ out:
 /*
  *	The 2.0 compatible umount. No flags.
  */
-asmlinkage long sys_oldumount(char __user * name)
+SYSCALL_DEFINE1(oldumount, char __user *, name)
 {
 	return sys_umount(name, 0);
 }
 
 #endif
 
-static int mount_is_safe(struct nameidata *nd)
+static int mount_is_safe(struct path *path)
 {
 	if (capable(CAP_SYS_ADMIN))
 		return 0;
 	return -EPERM;
 #ifdef notyet
-	if (S_ISLNK(nd->path.dentry->d_inode->i_mode))
+	if (S_ISLNK(path->dentry->d_inode->i_mode))
 		return -EPERM;
-	if (nd->path.dentry->d_inode->i_mode & S_ISVTX) {
-		if (current->uid != nd->path.dentry->d_inode->i_uid)
+	if (path->dentry->d_inode->i_mode & S_ISVTX) {
+		if (current_uid() != path->dentry->d_inode->i_uid)
 			return -EPERM;
 	}
-	if (vfs_permission(nd, MAY_WRITE))
+	if (inode_permission(path->dentry->d_inode, MAY_WRITE))
 		return -EPERM;
 	return 0;
 #endif
@@ -1423,11 +1427,10 @@ out_unlock:
 
 /*
  * recursively change the type of the mountpoint.
- * noinline this do_mount helper to save do_mount stack space.
  */
-static noinline int do_change_type(struct nameidata *nd, int flag)
+static int do_change_type(struct path *path, int flag)
 {
-	struct vfsmount *m, *mnt = nd->path.mnt;
+	struct vfsmount *m, *mnt = path->mnt;
 	int recurse = flag & MS_REC;
 	int type = flag & ~MS_REC;
 	int err = 0;
@@ -1435,7 +1438,7 @@ static noinline int do_change_type(struct nameidata *nd, int flag)
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 
-	if (nd->path.dentry != nd->path.mnt->mnt_root)
+	if (path->dentry != path->mnt->mnt_root)
 		return -EINVAL;
 
 	down_write(&namespace_sem);
@@ -1457,40 +1460,39 @@ static noinline int do_change_type(struct nameidata *nd, int flag)
 
 /*
  * do loopback mount.
- * noinline this do_mount helper to save do_mount stack space.
  */
-static noinline int do_loopback(struct nameidata *nd, char *old_name,
+static int do_loopback(struct path *path, char *old_name,
 				int recurse)
 {
-	struct nameidata old_nd;
+	struct path old_path;
 	struct vfsmount *mnt = NULL;
-	int err = mount_is_safe(nd);
+	int err = mount_is_safe(path);
 	if (err)
 		return err;
 	if (!old_name || !*old_name)
 		return -EINVAL;
-	err = path_lookup(old_name, LOOKUP_FOLLOW, &old_nd);
+	err = kern_path(old_name, LOOKUP_FOLLOW, &old_path);
 	if (err)
 		return err;
 
 	down_write(&namespace_sem);
 	err = -EINVAL;
-	if (IS_MNT_UNBINDABLE(old_nd.path.mnt))
+	if (IS_MNT_UNBINDABLE(old_path.mnt))
 		goto out;
 
-	if (!check_mnt(nd->path.mnt) || !check_mnt(old_nd.path.mnt))
+	if (!check_mnt(path->mnt) || !check_mnt(old_path.mnt))
 		goto out;
 
 	err = -ENOMEM;
 	if (recurse)
-		mnt = copy_tree(old_nd.path.mnt, old_nd.path.dentry, 0);
+		mnt = copy_tree(old_path.mnt, old_path.dentry, 0);
 	else
-		mnt = clone_mnt(old_nd.path.mnt, old_nd.path.dentry, 0);
+		mnt = clone_mnt(old_path.mnt, old_path.dentry, 0);
 
 	if (!mnt)
 		goto out;
 
-	err = graft_tree(mnt, &nd->path);
+	err = graft_tree(mnt, path);
 	if (err) {
 		LIST_HEAD(umount_list);
 		spin_lock(&vfsmount_lock);
@@ -1501,7 +1503,7 @@ static noinline int do_loopback(struct nameidata *nd, char *old_name,
 
 out:
 	up_write(&namespace_sem);
-	path_put(&old_nd.path);
+	path_put(&old_path);
 	return err;
 }
 
@@ -1526,33 +1528,37 @@ static int change_mount_flags(struct vfsmount *mnt, int ms_flags)
  * 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.
- * noinline this do_mount helper to save do_mount stack space.
  */
-static noinline int do_remount(struct nameidata *nd, int flags, int mnt_flags,
+static int do_remount(struct path *path, int flags, int mnt_flags,
 		      void *data)
 {
 	int err;
-	struct super_block *sb = nd->path.mnt->mnt_sb;
+	struct super_block *sb = path->mnt->mnt_sb;
 
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 
-	if (!check_mnt(nd->path.mnt))
+	if (!check_mnt(path->mnt))
 		return -EINVAL;
 
-	if (nd->path.dentry != nd->path.mnt->mnt_root)
+	if (path->dentry != path->mnt->mnt_root)
 		return -EINVAL;
 
 	down_write(&sb->s_umount);
 	if (flags & MS_BIND)
-		err = change_mount_flags(nd->path.mnt, flags);
+		err = change_mount_flags(path->mnt, flags);
 	else
 		err = do_remount_sb(sb, flags, data, 0);
 	if (!err)
-		nd->path.mnt->mnt_flags = mnt_flags;
+		path->mnt->mnt_flags = mnt_flags;
 	up_write(&sb->s_umount);
-	if (!err)
-		security_sb_post_remount(nd->path.mnt, flags, data);
+	if (!err) {
+		security_sb_post_remount(path->mnt, flags, data);
+
+		spin_lock(&vfsmount_lock);
+		touch_mnt_namespace(path->mnt->mnt_ns);
+		spin_unlock(&vfsmount_lock);
+	}
 	return err;
 }
 
@@ -1566,90 +1572,85 @@ static inline int tree_contains_unbindable(struct vfsmount *mnt)
 	return 0;
 }
 
-/*
- * noinline this do_mount helper to save do_mount stack space.
- */
-static noinline int do_move_mount(struct nameidata *nd, char *old_name)
+static int do_move_mount(struct path *path, char *old_name)
 {
-	struct nameidata old_nd;
-	struct path parent_path;
+	struct path old_path, parent_path;
 	struct vfsmount *p;
 	int err = 0;
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 	if (!old_name || !*old_name)
 		return -EINVAL;
-	err = path_lookup(old_name, LOOKUP_FOLLOW, &old_nd);
+	err = kern_path(old_name, LOOKUP_FOLLOW, &old_path);
 	if (err)
 		return err;
 
 	down_write(&namespace_sem);
-	while (d_mountpoint(nd->path.dentry) &&
-	       follow_down(&nd->path.mnt, &nd->path.dentry))
+	while (d_mountpoint(path->dentry) &&
+	       follow_down(&path->mnt, &path->dentry))
 		;
 	err = -EINVAL;
-	if (!check_mnt(nd->path.mnt) || !check_mnt(old_nd.path.mnt))
+	if (!check_mnt(path->mnt) || !check_mnt(old_path.mnt))
 		goto out;
 
 	err = -ENOENT;
-	mutex_lock(&nd->path.dentry->d_inode->i_mutex);
-	if (IS_DEADDIR(nd->path.dentry->d_inode))
+	mutex_lock(&path->dentry->d_inode->i_mutex);
+	if (IS_DEADDIR(path->dentry->d_inode))
 		goto out1;
 
-	if (!IS_ROOT(nd->path.dentry) && d_unhashed(nd->path.dentry))
+	if (!IS_ROOT(path->dentry) && d_unhashed(path->dentry))
 		goto out1;
 
 	err = -EINVAL;
-	if (old_nd.path.dentry != old_nd.path.mnt->mnt_root)
+	if (old_path.dentry != old_path.mnt->mnt_root)
 		goto out1;
 
-	if (old_nd.path.mnt == old_nd.path.mnt->mnt_parent)
+	if (old_path.mnt == old_path.mnt->mnt_parent)
 		goto out1;
 
-	if (S_ISDIR(nd->path.dentry->d_inode->i_mode) !=
-	      S_ISDIR(old_nd.path.dentry->d_inode->i_mode))
+	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 (old_nd.path.mnt->mnt_parent &&
-	    IS_MNT_SHARED(old_nd.path.mnt->mnt_parent))
+	if (old_path.mnt->mnt_parent &&
+	    IS_MNT_SHARED(old_path.mnt->mnt_parent))
 		goto out1;
 	/*
 	 * Don't move a mount tree containing unbindable mounts to a destination
 	 * mount which is shared.
 	 */
-	if (IS_MNT_SHARED(nd->path.mnt) &&
-	    tree_contains_unbindable(old_nd.path.mnt))
+	if (IS_MNT_SHARED(path->mnt) &&
+	    tree_contains_unbindable(old_path.mnt))
 		goto out1;
 	err = -ELOOP;
-	for (p = nd->path.mnt; p->mnt_parent != p; p = p->mnt_parent)
-		if (p == old_nd.path.mnt)
+	for (p = path->mnt; p->mnt_parent != p; p = p->mnt_parent)
+		if (p == old_path.mnt)
 			goto out1;
 
-	err = attach_recursive_mnt(old_nd.path.mnt, &nd->path, &parent_path);
+	err = attach_recursive_mnt(old_path.mnt, path, &parent_path);
 	if (err)
 		goto out1;
 
 	/* if the mount is moved, it should no longer be expire
 	 * automatically */
-	list_del_init(&old_nd.path.mnt->mnt_expire);
+	list_del_init(&old_path.mnt->mnt_expire);
 out1:
-	mutex_unlock(&nd->path.dentry->d_inode->i_mutex);
+	mutex_unlock(&path->dentry->d_inode->i_mutex);
 out:
 	up_write(&namespace_sem);
 	if (!err)
 		path_put(&parent_path);
-	path_put(&old_nd.path);
+	path_put(&old_path);
 	return err;
 }
 
 /*
  * create a new mount for userspace and request it to be added into the
  * namespace's tree
- * noinline this do_mount helper to save do_mount stack space.
  */
-static noinline int do_new_mount(struct nameidata *nd, char *type, int flags,
+static int do_new_mount(struct path *path, char *type, int flags,
 			int mnt_flags, char *name, void *data)
 {
 	struct vfsmount *mnt;
@@ -1665,31 +1666,31 @@ static noinline int do_new_mount(struct nameidata *nd, char *type, int flags,
 	if (IS_ERR(mnt))
 		return PTR_ERR(mnt);
 
-	return do_add_mount(mnt, nd, mnt_flags, NULL);
+	return do_add_mount(mnt, path, mnt_flags, NULL);
 }
 
 /*
  * add a mount into a namespace's mount tree
  * - provide the option of adding the new mount to an expiration list
  */
-int do_add_mount(struct vfsmount *newmnt, struct nameidata *nd,
+int do_add_mount(struct vfsmount *newmnt, struct path *path,
 		 int mnt_flags, struct list_head *fslist)
 {
 	int err;
 
 	down_write(&namespace_sem);
 	/* Something was mounted here while we slept */
-	while (d_mountpoint(nd->path.dentry) &&
-	       follow_down(&nd->path.mnt, &nd->path.dentry))
+	while (d_mountpoint(path->dentry) &&
+	       follow_down(&path->mnt, &path->dentry))
 		;
 	err = -EINVAL;
-	if (!check_mnt(nd->path.mnt))
+	if (!check_mnt(path->mnt))
 		goto unlock;
 
 	/* Refuse the same filesystem on the same mount point */
 	err = -EBUSY;
-	if (nd->path.mnt->mnt_sb == newmnt->mnt_sb &&
-	    nd->path.mnt->mnt_root == nd->path.dentry)
+	if (path->mnt->mnt_sb == newmnt->mnt_sb &&
+	    path->mnt->mnt_root == path->dentry)
 		goto unlock;
 
 	err = -EINVAL;
@@ -1697,7 +1698,7 @@ int do_add_mount(struct vfsmount *newmnt, struct nameidata *nd,
 		goto unlock;
 
 	newmnt->mnt_flags = mnt_flags;
-	if ((err = graft_tree(newmnt, &nd->path)))
+	if ((err = graft_tree(newmnt, path)))
 		goto unlock;
 
 	if (fslist) /* add to the specified expiration list */
@@ -1816,8 +1817,8 @@ static void shrink_submounts(struct vfsmount *mnt, struct list_head *umounts)
 		while (!list_empty(&graveyard)) {
 			m = list_first_entry(&graveyard, struct vfsmount,
 						mnt_expire);
-			touch_mnt_namespace(mnt->mnt_ns);
-			umount_tree(mnt, 1, umounts);
+			touch_mnt_namespace(m->mnt_ns);
+			umount_tree(m, 1, umounts);
 		}
 	}
 }
@@ -1900,7 +1901,7 @@ int copy_mount_options(const void __user * data, unsigned long *where)
 long do_mount(char *dev_name, char *dir_name, char *type_page,
 		  unsigned long flags, void *data_page)
 {
-	struct nameidata nd;
+	struct path path;
 	int retval = 0;
 	int mnt_flags = 0;
 
@@ -1918,6 +1919,9 @@ long do_mount(char *dev_name, char *dir_name, char *type_page,
 	if (data_page)
 		((char *)data_page)[PAGE_SIZE - 1] = 0;
 
+	/* Default to relatime */
+	mnt_flags |= MNT_RELATIME;
+
 	/* Separate the per-mountpoint flags */
 	if (flags & MS_NOSUID)
 		mnt_flags |= MNT_NOSUID;
@@ -1929,38 +1933,39 @@ long do_mount(char *dev_name, char *dir_name, char *type_page,
 		mnt_flags |= MNT_NOATIME;
 	if (flags & MS_NODIRATIME)
 		mnt_flags |= MNT_NODIRATIME;
-	if (flags & MS_RELATIME)
-		mnt_flags |= MNT_RELATIME;
+	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_NOATIME | MS_NODIRATIME | MS_RELATIME| MS_KERNMOUNT);
+		   MS_NOATIME | MS_NODIRATIME | MS_RELATIME| MS_KERNMOUNT |
+		   MS_STRICTATIME);
 
 	/* ... and get the mountpoint */
-	retval = path_lookup(dir_name, LOOKUP_FOLLOW, &nd);
+	retval = kern_path(dir_name, LOOKUP_FOLLOW, &path);
 	if (retval)
 		return retval;
 
-	retval = security_sb_mount(dev_name, &nd.path,
+	retval = security_sb_mount(dev_name, &path,
 				   type_page, flags, data_page);
 	if (retval)
 		goto dput_out;
 
 	if (flags & MS_REMOUNT)
-		retval = do_remount(&nd, flags & ~MS_REMOUNT, mnt_flags,
+		retval = do_remount(&path, flags & ~MS_REMOUNT, mnt_flags,
 				    data_page);
 	else if (flags & MS_BIND)
-		retval = do_loopback(&nd, dev_name, flags & MS_REC);
+		retval = do_loopback(&path, dev_name, flags & MS_REC);
 	else if (flags & (MS_SHARED | MS_PRIVATE | MS_SLAVE | MS_UNBINDABLE))
-		retval = do_change_type(&nd, flags);
+		retval = do_change_type(&path, flags);
 	else if (flags & MS_MOVE)
-		retval = do_move_mount(&nd, dev_name);
+		retval = do_move_mount(&path, dev_name);
 	else
-		retval = do_new_mount(&nd, type_page, flags, mnt_flags,
+		retval = do_new_mount(&path, type_page, flags, mnt_flags,
 				      dev_name, data_page);
 dput_out:
-	path_put(&nd.path);
+	path_put(&path);
 	return retval;
 }
 
@@ -1972,7 +1977,7 @@ 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, *altrootmnt = NULL;
+	struct vfsmount *rootmnt = NULL, *pwdmnt = NULL;
 	struct vfsmount *p, *q;
 
 	new_ns = kmalloc(sizeof(struct mnt_namespace), GFP_KERNEL);
@@ -1991,7 +1996,7 @@ static struct mnt_namespace *dup_mnt_ns(struct mnt_namespace *mnt_ns,
 	if (!new_ns->root) {
 		up_write(&namespace_sem);
 		kfree(new_ns);
-		return ERR_PTR(-ENOMEM);;
+		return ERR_PTR(-ENOMEM);
 	}
 	spin_lock(&vfsmount_lock);
 	list_add_tail(&new_ns->list, &new_ns->root->mnt_list);
@@ -2015,10 +2020,6 @@ static struct mnt_namespace *dup_mnt_ns(struct mnt_namespace *mnt_ns,
 				pwdmnt = p;
 				fs->pwd.mnt = mntget(q);
 			}
-			if (p == fs->altroot.mnt) {
-				altrootmnt = p;
-				fs->altroot.mnt = mntget(q);
-			}
 		}
 		p = next_mnt(p, mnt_ns->root);
 		q = next_mnt(q, new_ns->root);
@@ -2029,8 +2030,6 @@ static struct mnt_namespace *dup_mnt_ns(struct mnt_namespace *mnt_ns,
 		mntput(rootmnt);
 	if (pwdmnt)
 		mntput(pwdmnt);
-	if (altrootmnt)
-		mntput(altrootmnt);
 
 	return new_ns;
 }
@@ -2052,9 +2051,8 @@ struct mnt_namespace *copy_mnt_ns(unsigned long flags, struct mnt_namespace *ns,
 	return new_ns;
 }
 
-asmlinkage long sys_mount(char __user * dev_name, char __user * dir_name,
-			  char __user * type, unsigned long flags,
-			  void __user * data)
+SYSCALL_DEFINE5(mount, char __user *, dev_name, char __user *, dir_name,
+		char __user *, type, unsigned long, flags, void __user *, data)
 {
 	int retval;
 	unsigned long data_page;
@@ -2095,66 +2093,6 @@ out1:
 }
 
 /*
- * Replace the fs->{rootmnt,root} with {mnt,dentry}. Put the old values.
- * It can block. Requires the big lock held.
- */
-void set_fs_root(struct fs_struct *fs, struct path *path)
-{
-	struct path old_root;
-
-	write_lock(&fs->lock);
-	old_root = fs->root;
-	fs->root = *path;
-	path_get(path);
-	write_unlock(&fs->lock);
-	if (old_root.dentry)
-		path_put(&old_root);
-}
-
-/*
- * Replace the fs->{pwdmnt,pwd} with {mnt,dentry}. Put the old values.
- * It can block. Requires the big lock held.
- */
-void set_fs_pwd(struct fs_struct *fs, struct path *path)
-{
-	struct path old_pwd;
-
-	write_lock(&fs->lock);
-	old_pwd = fs->pwd;
-	fs->pwd = *path;
-	path_get(path);
-	write_unlock(&fs->lock);
-
-	if (old_pwd.dentry)
-		path_put(&old_pwd);
-}
-
-static void chroot_fs_refs(struct path *old_root, struct path *new_root)
-{
-	struct task_struct *g, *p;
-	struct fs_struct *fs;
-
-	read_lock(&tasklist_lock);
-	do_each_thread(g, p) {
-		task_lock(p);
-		fs = p->fs;
-		if (fs) {
-			atomic_inc(&fs->count);
-			task_unlock(p);
-			if (fs->root.dentry == old_root->dentry
-			    && fs->root.mnt == old_root->mnt)
-				set_fs_root(fs, new_root);
-			if (fs->pwd.dentry == old_root->dentry
-			    && fs->pwd.mnt == old_root->mnt)
-				set_fs_pwd(fs, new_root);
-			put_fs_struct(fs);
-		} else
-			task_unlock(p);
-	} while_each_thread(g, p);
-	read_unlock(&tasklist_lock);
-}
-
-/*
  * 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
@@ -2179,32 +2117,30 @@ static void chroot_fs_refs(struct path *old_root, struct path *new_root)
  *    though, so you may need to say mount --bind /nfs/my_root /nfs/my_root
  *    first.
  */
-asmlinkage long sys_pivot_root(const char __user * new_root,
-			       const char __user * put_old)
+SYSCALL_DEFINE2(pivot_root, const char __user *, new_root,
+		const char __user *, put_old)
 {
 	struct vfsmount *tmp;
-	struct nameidata new_nd, old_nd;
-	struct path parent_path, root_parent, root;
+	struct path new, old, parent_path, root_parent, root;
 	int error;
 
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
 
-	error = __user_walk(new_root, LOOKUP_FOLLOW | LOOKUP_DIRECTORY,
-			    &new_nd);
+	error = user_path_dir(new_root, &new);
 	if (error)
 		goto out0;
 	error = -EINVAL;
-	if (!check_mnt(new_nd.path.mnt))
+	if (!check_mnt(new.mnt))
 		goto out1;
 
-	error = __user_walk(put_old, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &old_nd);
+	error = user_path_dir(put_old, &old);
 	if (error)
 		goto out1;
 
-	error = security_sb_pivotroot(&old_nd.path, &new_nd.path);
+	error = security_sb_pivotroot(&old, &new);
 	if (error) {
-		path_put(&old_nd.path);
+		path_put(&old);
 		goto out1;
 	}
 
@@ -2213,69 +2149,69 @@ asmlinkage long sys_pivot_root(const char __user * new_root,
 	path_get(&current->fs->root);
 	read_unlock(&current->fs->lock);
 	down_write(&namespace_sem);
-	mutex_lock(&old_nd.path.dentry->d_inode->i_mutex);
+	mutex_lock(&old.dentry->d_inode->i_mutex);
 	error = -EINVAL;
-	if (IS_MNT_SHARED(old_nd.path.mnt) ||
-		IS_MNT_SHARED(new_nd.path.mnt->mnt_parent) ||
+	if (IS_MNT_SHARED(old.mnt) ||
+		IS_MNT_SHARED(new.mnt->mnt_parent) ||
 		IS_MNT_SHARED(root.mnt->mnt_parent))
 		goto out2;
 	if (!check_mnt(root.mnt))
 		goto out2;
 	error = -ENOENT;
-	if (IS_DEADDIR(new_nd.path.dentry->d_inode))
+	if (IS_DEADDIR(new.dentry->d_inode))
 		goto out2;
-	if (d_unhashed(new_nd.path.dentry) && !IS_ROOT(new_nd.path.dentry))
+	if (d_unhashed(new.dentry) && !IS_ROOT(new.dentry))
 		goto out2;
-	if (d_unhashed(old_nd.path.dentry) && !IS_ROOT(old_nd.path.dentry))
+	if (d_unhashed(old.dentry) && !IS_ROOT(old.dentry))
 		goto out2;
 	error = -EBUSY;
-	if (new_nd.path.mnt == root.mnt ||
-	    old_nd.path.mnt == root.mnt)
+	if (new.mnt == root.mnt ||
+	    old.mnt == root.mnt)
 		goto out2; /* loop, on the same file system  */
 	error = -EINVAL;
 	if (root.mnt->mnt_root != root.dentry)
 		goto out2; /* not a mountpoint */
 	if (root.mnt->mnt_parent == root.mnt)
 		goto out2; /* not attached */
-	if (new_nd.path.mnt->mnt_root != new_nd.path.dentry)
+	if (new.mnt->mnt_root != new.dentry)
 		goto out2; /* not a mountpoint */
-	if (new_nd.path.mnt->mnt_parent == new_nd.path.mnt)
+	if (new.mnt->mnt_parent == new.mnt)
 		goto out2; /* not attached */
 	/* make sure we can reach put_old from new_root */
-	tmp = old_nd.path.mnt;
+	tmp = old.mnt;
 	spin_lock(&vfsmount_lock);
-	if (tmp != new_nd.path.mnt) {
+	if (tmp != new.mnt) {
 		for (;;) {
 			if (tmp->mnt_parent == tmp)
 				goto out3; /* already mounted on put_old */
-			if (tmp->mnt_parent == new_nd.path.mnt)
+			if (tmp->mnt_parent == new.mnt)
 				break;
 			tmp = tmp->mnt_parent;
 		}
-		if (!is_subdir(tmp->mnt_mountpoint, new_nd.path.dentry))
+		if (!is_subdir(tmp->mnt_mountpoint, new.dentry))
 			goto out3;
-	} else if (!is_subdir(old_nd.path.dentry, new_nd.path.dentry))
+	} else if (!is_subdir(old.dentry, new.dentry))
 		goto out3;
-	detach_mnt(new_nd.path.mnt, &parent_path);
+	detach_mnt(new.mnt, &parent_path);
 	detach_mnt(root.mnt, &root_parent);
 	/* mount old root on put_old */
-	attach_mnt(root.mnt, &old_nd.path);
+	attach_mnt(root.mnt, &old);
 	/* mount new_root on / */
-	attach_mnt(new_nd.path.mnt, &root_parent);
+	attach_mnt(new.mnt, &root_parent);
 	touch_mnt_namespace(current->nsproxy->mnt_ns);
 	spin_unlock(&vfsmount_lock);
-	chroot_fs_refs(&root, &new_nd.path);
-	security_sb_post_pivotroot(&root, &new_nd.path);
+	chroot_fs_refs(&root, &new);
+	security_sb_post_pivotroot(&root, &new);
 	error = 0;
 	path_put(&root_parent);
 	path_put(&parent_path);
 out2:
-	mutex_unlock(&old_nd.path.dentry->d_inode->i_mutex);
+	mutex_unlock(&old.dentry->d_inode->i_mutex);
 	up_write(&namespace_sem);
 	path_put(&root);
-	path_put(&old_nd.path);
+	path_put(&old);
 out1:
-	path_put(&new_nd.path);
+	path_put(&new);
 out0:
 	return error;
 out3: