8 files changed, 3618 insertions, 0 deletions

diff --git a/fs/autofs/autofs_i.h b/fs/autofs/autofs_i.h
new file mode 100644
index 000000000000..9110b66c7ef1
--- /dev/null
+++ b/fs/autofs/autofs_i.h
@@ -0,0 +1,273 @@
+/*
+ *  Copyright 1997-1998 Transmeta Corporation - All Rights Reserved
+ *  Copyright 2005-2006 Ian Kent <raven@themaw.net>
+ *
+ * This file is part of the Linux kernel and is made available under
+ * the terms of the GNU General Public License, version 2, or at your
+ * option, any later version, incorporated herein by reference.
+ */
+
+/* Internal header file for autofs */
+
+#include <linux/auto_fs.h>
+#include <linux/auto_dev-ioctl.h>
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/time.h>
+#include <linux/string.h>
+#include <linux/wait.h>
+#include <linux/sched.h>
+#include <linux/mount.h>
+#include <linux/namei.h>
+#include <linux/uaccess.h>
+#include <linux/mutex.h>
+#include <linux/spinlock.h>
+#include <linux/list.h>
+#include <linux/completion.h>
+#include <asm/current.h>
+
+/* This is the range of ioctl() numbers we claim as ours */
+#define AUTOFS_IOC_FIRST     AUTOFS_IOC_READY
+#define AUTOFS_IOC_COUNT     32
+
+#define AUTOFS_DEV_IOCTL_IOC_FIRST	(AUTOFS_DEV_IOCTL_VERSION)
+#define AUTOFS_DEV_IOCTL_IOC_COUNT \
+	(AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD - AUTOFS_DEV_IOCTL_VERSION_CMD)
+
+#ifdef pr_fmt
+#undef pr_fmt
+#endif
+#define pr_fmt(fmt) KBUILD_MODNAME ":pid:%d:%s: " fmt, current->pid, __func__
+
+/*
+ * Unified info structure.  This is pointed to by both the dentry and
+ * inode structures.  Each file in the filesystem has an instance of this
+ * structure.  It holds a reference to the dentry, so dentries are never
+ * flushed while the file exists.  All name lookups are dealt with at the
+ * dentry level, although the filesystem can interfere in the validation
+ * process.  Readdir is implemented by traversing the dentry lists.
+ */
+struct autofs_info {
+	struct dentry	*dentry;
+	struct inode	*inode;
+
+	int		flags;
+
+	struct completion expire_complete;
+
+	struct list_head active;
+	int active_count;
+
+	struct list_head expiring;
+
+	struct autofs_sb_info *sbi;
+	unsigned long last_used;
+	atomic_t count;
+
+	kuid_t uid;
+	kgid_t gid;
+};
+
+#define AUTOFS_INF_EXPIRING	(1<<0) /* dentry in the process of expiring */
+#define AUTOFS_INF_WANT_EXPIRE	(1<<1) /* the dentry is being considered
+					* for expiry, so RCU_walk is
+					* not permitted.  If it progresses to
+					* actual expiry attempt, the flag is
+					* not cleared when EXPIRING is set -
+					* in that case it gets cleared only
+					* when it comes to clearing EXPIRING.
+					*/
+#define AUTOFS_INF_PENDING	(1<<2) /* dentry pending mount */
+
+struct autofs_wait_queue {
+	wait_queue_head_t queue;
+	struct autofs_wait_queue *next;
+	autofs_wqt_t wait_queue_token;
+	/* We use the following to see what we are waiting for */
+	struct qstr name;
+	u32 dev;
+	u64 ino;
+	kuid_t uid;
+	kgid_t gid;
+	pid_t pid;
+	pid_t tgid;
+	/* This is for status reporting upon return */
+	int status;
+	unsigned int wait_ctr;
+};
+
+#define AUTOFS_SBI_MAGIC 0x6d4a556d
+
+struct autofs_sb_info {
+	u32 magic;
+	int pipefd;
+	struct file *pipe;
+	struct pid *oz_pgrp;
+	int catatonic;
+	int version;
+	int sub_version;
+	int min_proto;
+	int max_proto;
+	unsigned long exp_timeout;
+	unsigned int type;
+	struct super_block *sb;
+	struct mutex wq_mutex;
+	struct mutex pipe_mutex;
+	spinlock_t fs_lock;
+	struct autofs_wait_queue *queues; /* Wait queue pointer */
+	spinlock_t lookup_lock;
+	struct list_head active_list;
+	struct list_head expiring_list;
+	struct rcu_head rcu;
+};
+
+static inline struct autofs_sb_info *autofs_sbi(struct super_block *sb)
+{
+	return (struct autofs_sb_info *)(sb->s_fs_info);
+}
+
+static inline struct autofs_info *autofs_dentry_ino(struct dentry *dentry)
+{
+	return (struct autofs_info *)(dentry->d_fsdata);
+}
+
+/* autofs_oz_mode(): do we see the man behind the curtain?  (The
+ * processes which do manipulations for us in user space sees the raw
+ * filesystem without "magic".)
+ */
+static inline int autofs_oz_mode(struct autofs_sb_info *sbi)
+{
+	return sbi->catatonic || task_pgrp(current) == sbi->oz_pgrp;
+}
+
+struct inode *autofs_get_inode(struct super_block *, umode_t);
+void autofs_free_ino(struct autofs_info *);
+
+/* Expiration */
+int is_autofs_dentry(struct dentry *);
+int autofs_expire_wait(const struct path *path, int rcu_walk);
+int autofs_expire_run(struct super_block *, struct vfsmount *,
+		      struct autofs_sb_info *,
+		      struct autofs_packet_expire __user *);
+int autofs_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
+			   struct autofs_sb_info *sbi, int when);
+int autofs_expire_multi(struct super_block *, struct vfsmount *,
+			struct autofs_sb_info *, int __user *);
+struct dentry *autofs_expire_direct(struct super_block *sb,
+				    struct vfsmount *mnt,
+				    struct autofs_sb_info *sbi, int how);
+struct dentry *autofs_expire_indirect(struct super_block *sb,
+				      struct vfsmount *mnt,
+				      struct autofs_sb_info *sbi, int how);
+
+/* Device node initialization */
+
+int autofs_dev_ioctl_init(void);
+void autofs_dev_ioctl_exit(void);
+
+/* Operations structures */
+
+extern const struct inode_operations autofs_symlink_inode_operations;
+extern const struct inode_operations autofs_dir_inode_operations;
+extern const struct file_operations autofs_dir_operations;
+extern const struct file_operations autofs_root_operations;
+extern const struct dentry_operations autofs_dentry_operations;
+
+/* VFS automount flags management functions */
+static inline void __managed_dentry_set_managed(struct dentry *dentry)
+{
+	dentry->d_flags |= (DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
+}
+
+static inline void managed_dentry_set_managed(struct dentry *dentry)
+{
+	spin_lock(&dentry->d_lock);
+	__managed_dentry_set_managed(dentry);
+	spin_unlock(&dentry->d_lock);
+}
+
+static inline void __managed_dentry_clear_managed(struct dentry *dentry)
+{
+	dentry->d_flags &= ~(DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
+}
+
+static inline void managed_dentry_clear_managed(struct dentry *dentry)
+{
+	spin_lock(&dentry->d_lock);
+	__managed_dentry_clear_managed(dentry);
+	spin_unlock(&dentry->d_lock);
+}
+
+/* Initializing function */
+
+int autofs_fill_super(struct super_block *, void *, int);
+struct autofs_info *autofs_new_ino(struct autofs_sb_info *);
+void autofs_clean_ino(struct autofs_info *);
+
+static inline int autofs_prepare_pipe(struct file *pipe)
+{
+	if (!(pipe->f_mode & FMODE_CAN_WRITE))
+		return -EINVAL;
+	if (!S_ISFIFO(file_inode(pipe)->i_mode))
+		return -EINVAL;
+	/* We want a packet pipe */
+	pipe->f_flags |= O_DIRECT;
+	return 0;
+}
+
+/* Queue management functions */
+
+int autofs_wait(struct autofs_sb_info *,
+		 const struct path *, enum autofs_notify);
+int autofs_wait_release(struct autofs_sb_info *, autofs_wqt_t, int);
+void autofs_catatonic_mode(struct autofs_sb_info *);
+
+static inline u32 autofs_get_dev(struct autofs_sb_info *sbi)
+{
+	return new_encode_dev(sbi->sb->s_dev);
+}
+
+static inline u64 autofs_get_ino(struct autofs_sb_info *sbi)
+{
+	return d_inode(sbi->sb->s_root)->i_ino;
+}
+
+static inline void __autofs_add_expiring(struct dentry *dentry)
+{
+	struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
+	struct autofs_info *ino = autofs_dentry_ino(dentry);
+
+	if (ino) {
+		if (list_empty(&ino->expiring))
+			list_add(&ino->expiring, &sbi->expiring_list);
+	}
+}
+
+static inline void autofs_add_expiring(struct dentry *dentry)
+{
+	struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
+	struct autofs_info *ino = autofs_dentry_ino(dentry);
+
+	if (ino) {
+		spin_lock(&sbi->lookup_lock);
+		if (list_empty(&ino->expiring))
+			list_add(&ino->expiring, &sbi->expiring_list);
+		spin_unlock(&sbi->lookup_lock);
+	}
+}
+
+static inline void autofs_del_expiring(struct dentry *dentry)
+{
+	struct autofs_sb_info *sbi = autofs_sbi(dentry->d_sb);
+	struct autofs_info *ino = autofs_dentry_ino(dentry);
+
+	if (ino) {
+		spin_lock(&sbi->lookup_lock);
+		if (!list_empty(&ino->expiring))
+			list_del_init(&ino->expiring);
+		spin_unlock(&sbi->lookup_lock);
+	}
+}
+
+void autofs_kill_sb(struct super_block *);
diff --git a/fs/autofs/dev-ioctl.c b/fs/autofs/dev-ioctl.c
new file mode 100644
index 000000000000..a2281ab2b957
--- /dev/null
+++ b/fs/autofs/dev-ioctl.c
@@ -0,0 +1,761 @@
+/*
+ * Copyright 2008 Red Hat, Inc. All rights reserved.
+ * Copyright 2008 Ian Kent <raven@themaw.net>
+ *
+ * This file is part of the Linux kernel and is made available under
+ * the terms of the GNU General Public License, version 2, or at your
+ * option, any later version, incorporated herein by reference.
+ */
+
+#include <linux/module.h>
+#include <linux/vmalloc.h>
+#include <linux/miscdevice.h>
+#include <linux/init.h>
+#include <linux/wait.h>
+#include <linux/namei.h>
+#include <linux/fcntl.h>
+#include <linux/file.h>
+#include <linux/fdtable.h>
+#include <linux/sched.h>
+#include <linux/cred.h>
+#include <linux/compat.h>
+#include <linux/syscalls.h>
+#include <linux/magic.h>
+#include <linux/dcache.h>
+#include <linux/uaccess.h>
+#include <linux/slab.h>
+
+#include "autofs_i.h"
+
+/*
+ * This module implements an interface for routing autofs ioctl control
+ * commands via a miscellaneous device file.
+ *
+ * The alternate interface is needed because we need to be able open
+ * an ioctl file descriptor on an autofs mount that may be covered by
+ * another mount. This situation arises when starting automount(8)
+ * or other user space daemon which uses direct mounts or offset
+ * mounts (used for autofs lazy mount/umount of nested mount trees),
+ * which have been left busy at at service shutdown.
+ */
+
+typedef int (*ioctl_fn)(struct file *, struct autofs_sb_info *,
+			struct autofs_dev_ioctl *);
+
+static int check_name(const char *name)
+{
+	if (!strchr(name, '/'))
+		return -EINVAL;
+	return 0;
+}
+
+/*
+ * Check a string doesn't overrun the chunk of
+ * memory we copied from user land.
+ */
+static int invalid_str(char *str, size_t size)
+{
+	if (memchr(str, 0, size))
+		return 0;
+	return -EINVAL;
+}
+
+/*
+ * Check that the user compiled against correct version of autofs
+ * misc device code.
+ *
+ * As well as checking the version compatibility this always copies
+ * the kernel interface version out.
+ */
+static int check_dev_ioctl_version(int cmd, struct autofs_dev_ioctl *param)
+{
+	int err = 0;
+
+	if ((param->ver_major != AUTOFS_DEV_IOCTL_VERSION_MAJOR) ||
+	    (param->ver_minor > AUTOFS_DEV_IOCTL_VERSION_MINOR)) {
+		pr_warn("ioctl control interface version mismatch: "
+			"kernel(%u.%u), user(%u.%u), cmd(0x%08x)\n",
+			AUTOFS_DEV_IOCTL_VERSION_MAJOR,
+			AUTOFS_DEV_IOCTL_VERSION_MINOR,
+			param->ver_major, param->ver_minor, cmd);
+		err = -EINVAL;
+	}
+
+	/* Fill in the kernel version. */
+	param->ver_major = AUTOFS_DEV_IOCTL_VERSION_MAJOR;
+	param->ver_minor = AUTOFS_DEV_IOCTL_VERSION_MINOR;
+
+	return err;
+}
+
+/*
+ * Copy parameter control struct, including a possible path allocated
+ * at the end of the struct.
+ */
+static struct autofs_dev_ioctl *
+copy_dev_ioctl(struct autofs_dev_ioctl __user *in)
+{
+	struct autofs_dev_ioctl tmp, *res;
+
+	if (copy_from_user(&tmp, in, AUTOFS_DEV_IOCTL_SIZE))
+		return ERR_PTR(-EFAULT);
+
+	if (tmp.size < AUTOFS_DEV_IOCTL_SIZE)
+		return ERR_PTR(-EINVAL);
+
+	if (tmp.size > AUTOFS_DEV_IOCTL_SIZE + PATH_MAX)
+		return ERR_PTR(-ENAMETOOLONG);
+
+	res = memdup_user(in, tmp.size);
+	if (!IS_ERR(res))
+		res->size = tmp.size;
+
+	return res;
+}
+
+static inline void free_dev_ioctl(struct autofs_dev_ioctl *param)
+{
+	kfree(param);
+}
+
+/*
+ * Check sanity of parameter control fields and if a path is present
+ * check that it is terminated and contains at least one "/".
+ */
+static int validate_dev_ioctl(int cmd, struct autofs_dev_ioctl *param)
+{
+	int err;
+
+	err = check_dev_ioctl_version(cmd, param);
+	if (err) {
+		pr_warn("invalid device control module version "
+			"supplied for cmd(0x%08x)\n", cmd);
+		goto out;
+	}
+
+	if (param->size > AUTOFS_DEV_IOCTL_SIZE) {
+		err = invalid_str(param->path, param->size - AUTOFS_DEV_IOCTL_SIZE);
+		if (err) {
+			pr_warn(
+			  "path string terminator missing for cmd(0x%08x)\n",
+			  cmd);
+			goto out;
+		}
+
+		err = check_name(param->path);
+		if (err) {
+			pr_warn("invalid path supplied for cmd(0x%08x)\n",
+				cmd);
+			goto out;
+		}
+	}
+
+	err = 0;
+out:
+	return err;
+}
+
+/*
+ * Get the autofs super block info struct from the file opened on
+ * the autofs mount point.
+ */
+static struct autofs_sb_info *autofs_dev_ioctl_sbi(struct file *f)
+{
+	struct autofs_sb_info *sbi = NULL;
+	struct inode *inode;
+
+	if (f) {
+		inode = file_inode(f);
+		sbi = autofs_sbi(inode->i_sb);
+	}
+	return sbi;
+}
+
+/* Return autofs dev ioctl version */
+static int autofs_dev_ioctl_version(struct file *fp,
+				    struct autofs_sb_info *sbi,
+				    struct autofs_dev_ioctl *param)
+{
+	/* This should have already been set. */
+	param->ver_major = AUTOFS_DEV_IOCTL_VERSION_MAJOR;
+	param->ver_minor = AUTOFS_DEV_IOCTL_VERSION_MINOR;
+	return 0;
+}
+
+/* Return autofs module protocol version */
+static int autofs_dev_ioctl_protover(struct file *fp,
+				     struct autofs_sb_info *sbi,
+				     struct autofs_dev_ioctl *param)
+{
+	param->protover.version = sbi->version;
+	return 0;
+}
+
+/* Return autofs module protocol sub version */
+static int autofs_dev_ioctl_protosubver(struct file *fp,
+					struct autofs_sb_info *sbi,
+					struct autofs_dev_ioctl *param)
+{
+	param->protosubver.sub_version = sbi->sub_version;
+	return 0;
+}
+
+/* Find the topmost mount satisfying test() */
+static int find_autofs_mount(const char *pathname,
+			     struct path *res,
+			     int test(const struct path *path, void *data),
+			     void *data)
+{
+	struct path path;
+	int err;
+
+	err = kern_path_mountpoint(AT_FDCWD, pathname, &path, 0);
+	if (err)
+		return err;
+	err = -ENOENT;
+	while (path.dentry == path.mnt->mnt_root) {
+		if (path.dentry->d_sb->s_magic == AUTOFS_SUPER_MAGIC) {
+			if (test(&path, data)) {
+				path_get(&path);
+				*res = path;
+				err = 0;
+				break;
+			}
+		}
+		if (!follow_up(&path))
+			break;
+	}
+	path_put(&path);
+	return err;
+}
+
+static int test_by_dev(const struct path *path, void *p)
+{
+	return path->dentry->d_sb->s_dev == *(dev_t *)p;
+}
+
+static int test_by_type(const struct path *path, void *p)
+{
+	struct autofs_info *ino = autofs_dentry_ino(path->dentry);
+
+	return ino && ino->sbi->type & *(unsigned *)p;
+}
+
+/*
+ * Open a file descriptor on the autofs mount point corresponding
+ * to the given path and device number (aka. new_encode_dev(sb->s_dev)).
+ */
+static int autofs_dev_ioctl_open_mountpoint(const char *name, dev_t devid)
+{
+	int err, fd;
+
+	fd = get_unused_fd_flags(O_CLOEXEC);
+	if (likely(fd >= 0)) {
+		struct file *filp;
+		struct path path;
+
+		err = find_autofs_mount(name, &path, test_by_dev, &devid);
+		if (err)
+			goto out;
+
+		filp = dentry_open(&path, O_RDONLY, current_cred());
+		path_put(&path);
+		if (IS_ERR(filp)) {
+			err = PTR_ERR(filp);
+			goto out;
+		}
+
+		fd_install(fd, filp);
+	}
+
+	return fd;
+
+out:
+	put_unused_fd(fd);
+	return err;
+}
+
+/* Open a file descriptor on an autofs mount point */
+static int autofs_dev_ioctl_openmount(struct file *fp,
+				      struct autofs_sb_info *sbi,
+				      struct autofs_dev_ioctl *param)
+{
+	const char *path;
+	dev_t devid;
+	int err, fd;
+
+	/* param->path has already been checked */
+	if (!param->openmount.devid)
+		return -EINVAL;
+
+	param->ioctlfd = -1;
+
+	path = param->path;
+	devid = new_decode_dev(param->openmount.devid);
+
+	err = 0;
+	fd = autofs_dev_ioctl_open_mountpoint(path, devid);
+	if (unlikely(fd < 0)) {
+		err = fd;
+		goto out;
+	}
+
+	param->ioctlfd = fd;
+out:
+	return err;
+}
+
+/* Close file descriptor allocated above (user can also use close(2)). */
+static int autofs_dev_ioctl_closemount(struct file *fp,
+				       struct autofs_sb_info *sbi,
+				       struct autofs_dev_ioctl *param)
+{
+	return ksys_close(param->ioctlfd);
+}
+
+/*
+ * Send "ready" status for an existing wait (either a mount or an expire
+ * request).
+ */
+static int autofs_dev_ioctl_ready(struct file *fp,
+				  struct autofs_sb_info *sbi,
+				  struct autofs_dev_ioctl *param)
+{
+	autofs_wqt_t token;
+
+	token = (autofs_wqt_t) param->ready.token;
+	return autofs_wait_release(sbi, token, 0);
+}
+
+/*
+ * Send "fail" status for an existing wait (either a mount or an expire
+ * request).
+ */
+static int autofs_dev_ioctl_fail(struct file *fp,
+				 struct autofs_sb_info *sbi,
+				 struct autofs_dev_ioctl *param)
+{
+	autofs_wqt_t token;
+	int status;
+
+	token = (autofs_wqt_t) param->fail.token;
+	status = param->fail.status < 0 ? param->fail.status : -ENOENT;
+	return autofs_wait_release(sbi, token, status);
+}
+
+/*
+ * Set the pipe fd for kernel communication to the daemon.
+ *
+ * Normally this is set at mount using an option but if we
+ * are reconnecting to a busy mount then we need to use this
+ * to tell the autofs mount about the new kernel pipe fd. In
+ * order to protect mounts against incorrectly setting the
+ * pipefd we also require that the autofs mount be catatonic.
+ *
+ * This also sets the process group id used to identify the
+ * controlling process (eg. the owning automount(8) daemon).
+ */
+static int autofs_dev_ioctl_setpipefd(struct file *fp,
+				      struct autofs_sb_info *sbi,
+				      struct autofs_dev_ioctl *param)
+{
+	int pipefd;
+	int err = 0;
+	struct pid *new_pid = NULL;
+
+	if (param->setpipefd.pipefd == -1)
+		return -EINVAL;
+
+	pipefd = param->setpipefd.pipefd;
+
+	mutex_lock(&sbi->wq_mutex);
+	if (!sbi->catatonic) {
+		mutex_unlock(&sbi->wq_mutex);
+		return -EBUSY;
+	} else {
+		struct file *pipe;
+
+		new_pid = get_task_pid(current, PIDTYPE_PGID);
+
+		if (ns_of_pid(new_pid) != ns_of_pid(sbi->oz_pgrp)) {
+			pr_warn("not allowed to change PID namespace\n");
+			err = -EINVAL;
+			goto out;
+		}
+
+		pipe = fget(pipefd);
+		if (!pipe) {
+			err = -EBADF;
+			goto out;
+		}
+		if (autofs_prepare_pipe(pipe) < 0) {
+			err = -EPIPE;
+			fput(pipe);
+			goto out;
+		}
+		swap(sbi->oz_pgrp, new_pid);
+		sbi->pipefd = pipefd;
+		sbi->pipe = pipe;
+		sbi->catatonic = 0;
+	}
+out:
+	put_pid(new_pid);
+	mutex_unlock(&sbi->wq_mutex);
+	return err;
+}
+
+/*
+ * Make the autofs mount point catatonic, no longer responsive to
+ * mount requests. Also closes the kernel pipe file descriptor.
+ */
+static int autofs_dev_ioctl_catatonic(struct file *fp,
+				      struct autofs_sb_info *sbi,
+				      struct autofs_dev_ioctl *param)
+{
+	autofs_catatonic_mode(sbi);
+	return 0;
+}
+
+/* Set the autofs mount timeout */
+static int autofs_dev_ioctl_timeout(struct file *fp,
+				    struct autofs_sb_info *sbi,
+				    struct autofs_dev_ioctl *param)
+{
+	unsigned long timeout;
+
+	timeout = param->timeout.timeout;
+	param->timeout.timeout = sbi->exp_timeout / HZ;
+	sbi->exp_timeout = timeout * HZ;
+	return 0;
+}
+
+/*
+ * Return the uid and gid of the last request for the mount
+ *
+ * When reconstructing an autofs mount tree with active mounts
+ * we need to re-connect to mounts that may have used the original
+ * process uid and gid (or string variations of them) for mount
+ * lookups within the map entry.
+ */
+static int autofs_dev_ioctl_requester(struct file *fp,
+				      struct autofs_sb_info *sbi,
+				      struct autofs_dev_ioctl *param)
+{
+	struct autofs_info *ino;
+	struct path path;
+	dev_t devid;
+	int err = -ENOENT;
+
+	if (param->size <= AUTOFS_DEV_IOCTL_SIZE) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	devid = sbi->sb->s_dev;
+
+	param->requester.uid = param->requester.gid = -1;
+
+	err = find_autofs_mount(param->path, &path, test_by_dev, &devid);
+	if (err)
+		goto out;
+
+	ino = autofs_dentry_ino(path.dentry);
+	if (ino) {
+		err = 0;
+		autofs_expire_wait(&path, 0);
+		spin_lock(&sbi->fs_lock);
+		param->requester.uid =
+			from_kuid_munged(current_user_ns(), ino->uid);
+		param->requester.gid =
+			from_kgid_munged(current_user_ns(), ino->gid);
+		spin_unlock(&sbi->fs_lock);
+	}
+	path_put(&path);
+out:
+	return err;
+}
+
+/*
+ * Call repeatedly until it returns -EAGAIN, meaning there's nothing
+ * more that can be done.
+ */
+static int autofs_dev_ioctl_expire(struct file *fp,
+				   struct autofs_sb_info *sbi,
+				   struct autofs_dev_ioctl *param)
+{
+	struct vfsmount *mnt;
+	int how;
+
+	how = param->expire.how;
+	mnt = fp->f_path.mnt;
+
+	return autofs_do_expire_multi(sbi->sb, mnt, sbi, how);
+}
+
+/* Check if autofs mount point is in use */
+static int autofs_dev_ioctl_askumount(struct file *fp,
+				      struct autofs_sb_info *sbi,
+				      struct autofs_dev_ioctl *param)
+{
+	param->askumount.may_umount = 0;
+	if (may_umount(fp->f_path.mnt))
+		param->askumount.may_umount = 1;
+	return 0;
+}
+
+/*
+ * Check if the given path is a mountpoint.
+ *
+ * If we are supplied with the file descriptor of an autofs
+ * mount we're looking for a specific mount. In this case
+ * the path is considered a mountpoint if it is itself a
+ * mountpoint or contains a mount, such as a multi-mount
+ * without a root mount. In this case we return 1 if the
+ * path is a mount point and the super magic of the covering
+ * mount if there is one or 0 if it isn't a mountpoint.
+ *
+ * If we aren't supplied with a file descriptor then we
+ * lookup the path and check if it is the root of a mount.
+ * If a type is given we are looking for a particular autofs
+ * mount and if we don't find a match we return fail. If the
+ * located path is the root of a mount we return 1 along with
+ * the super magic of the mount or 0 otherwise.
+ *
+ * In both cases the the device number (as returned by
+ * new_encode_dev()) is also returned.
+ */
+static int autofs_dev_ioctl_ismountpoint(struct file *fp,
+					 struct autofs_sb_info *sbi,
+					 struct autofs_dev_ioctl *param)
+{
+	struct path path;
+	const char *name;
+	unsigned int type;
+	unsigned int devid, magic;
+	int err = -ENOENT;
+
+	if (param->size <= AUTOFS_DEV_IOCTL_SIZE) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	name = param->path;
+	type = param->ismountpoint.in.type;
+
+	param->ismountpoint.out.devid = devid = 0;
+	param->ismountpoint.out.magic = magic = 0;
+
+	if (!fp || param->ioctlfd == -1) {
+		if (autofs_type_any(type))
+			err = kern_path_mountpoint(AT_FDCWD,
+						   name, &path, LOOKUP_FOLLOW);
+		else
+			err = find_autofs_mount(name, &path,
+						test_by_type, &type);
+		if (err)
+			goto out;
+		devid = new_encode_dev(path.dentry->d_sb->s_dev);
+		err = 0;
+		if (path.mnt->mnt_root == path.dentry) {
+			err = 1;
+			magic = path.dentry->d_sb->s_magic;
+		}
+	} else {
+		dev_t dev = sbi->sb->s_dev;
+
+		err = find_autofs_mount(name, &path, test_by_dev, &dev);
+		if (err)
+			goto out;
+
+		devid = new_encode_dev(dev);
+
+		err = path_has_submounts(&path);
+
+		if (follow_down_one(&path))
+			magic = path.dentry->d_sb->s_magic;
+	}
+
+	param->ismountpoint.out.devid = devid;
+	param->ismountpoint.out.magic = magic;
+	path_put(&path);
+out:
+	return err;
+}
+
+/*
+ * Our range of ioctl numbers isn't 0 based so we need to shift
+ * the array index by _IOC_NR(AUTOFS_CTL_IOC_FIRST) for the table
+ * lookup.
+ */
+#define cmd_idx(cmd)	(cmd - _IOC_NR(AUTOFS_DEV_IOCTL_IOC_FIRST))
+
+static ioctl_fn lookup_dev_ioctl(unsigned int cmd)
+{
+	static ioctl_fn _ioctls[] = {
+		autofs_dev_ioctl_version,
+		autofs_dev_ioctl_protover,
+		autofs_dev_ioctl_protosubver,
+		autofs_dev_ioctl_openmount,
+		autofs_dev_ioctl_closemount,
+		autofs_dev_ioctl_ready,
+		autofs_dev_ioctl_fail,
+		autofs_dev_ioctl_setpipefd,
+		autofs_dev_ioctl_catatonic,
+		autofs_dev_ioctl_timeout,
+		autofs_dev_ioctl_requester,
+		autofs_dev_ioctl_expire,
+		autofs_dev_ioctl_askumount,
+		autofs_dev_ioctl_ismountpoint,
+	};
+	unsigned int idx = cmd_idx(cmd);
+
+	return (idx >= ARRAY_SIZE(_ioctls)) ? NULL : _ioctls[idx];
+}
+
+/* ioctl dispatcher */
+static int _autofs_dev_ioctl(unsigned int command,
+			     struct autofs_dev_ioctl __user *user)
+{
+	struct autofs_dev_ioctl *param;
+	struct file *fp;
+	struct autofs_sb_info *sbi;
+	unsigned int cmd_first, cmd;
+	ioctl_fn fn = NULL;
+	int err = 0;
+
+	cmd_first = _IOC_NR(AUTOFS_DEV_IOCTL_IOC_FIRST);
+	cmd = _IOC_NR(command);
+
+	if (_IOC_TYPE(command) != _IOC_TYPE(AUTOFS_DEV_IOCTL_IOC_FIRST) ||
+	    cmd - cmd_first > AUTOFS_DEV_IOCTL_IOC_COUNT) {
+		return -ENOTTY;
+	}
+
+	/* Only root can use ioctls other than AUTOFS_DEV_IOCTL_VERSION_CMD
+	 * and AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD
+	 */
+	if (cmd != AUTOFS_DEV_IOCTL_VERSION_CMD &&
+	    cmd != AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD &&
+	    !capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	/* Copy the parameters into kernel space. */
+	param = copy_dev_ioctl(user);
+	if (IS_ERR(param))
+		return PTR_ERR(param);
+
+	err = validate_dev_ioctl(command, param);
+	if (err)
+		goto out;
+
+	fn = lookup_dev_ioctl(cmd);
+	if (!fn) {
+		pr_warn("unknown command 0x%08x\n", command);
+		err = -ENOTTY;
+		goto out;
+	}
+
+	fp = NULL;
+	sbi = NULL;
+
+	/*
+	 * For obvious reasons the openmount can't have a file
+	 * descriptor yet. We don't take a reference to the
+	 * file during close to allow for immediate release,
+	 * and the same for retrieving ioctl version.
+	 */
+	if (cmd != AUTOFS_DEV_IOCTL_VERSION_CMD &&
+	    cmd != AUTOFS_DEV_IOCTL_OPENMOUNT_CMD &&
+	    cmd != AUTOFS_DEV_IOCTL_CLOSEMOUNT_CMD) {
+		fp = fget(param->ioctlfd);
+		if (!fp) {
+			if (cmd == AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD)
+				goto cont;
+			err = -EBADF;
+			goto out;
+		}
+
+		sbi = autofs_dev_ioctl_sbi(fp);
+		if (!sbi || sbi->magic != AUTOFS_SBI_MAGIC) {
+			err = -EINVAL;
+			fput(fp);
+			goto out;
+		}
+
+		/*
+		 * Admin needs to be able to set the mount catatonic in
+		 * order to be able to perform the re-open.
+		 */
+		if (!autofs_oz_mode(sbi) &&
+		    cmd != AUTOFS_DEV_IOCTL_CATATONIC_CMD) {
+			err = -EACCES;
+			fput(fp);
+			goto out;
+		}
+	}
+cont:
+	err = fn(fp, sbi, param);
+
+	if (fp)
+		fput(fp);
+	if (err >= 0 && copy_to_user(user, param, AUTOFS_DEV_IOCTL_SIZE))
+		err = -EFAULT;
+out:
+	free_dev_ioctl(param);
+	return err;
+}
+
+static long autofs_dev_ioctl(struct file *file, unsigned int command,
+			     unsigned long u)
+{
+	int err;
+
+	err = _autofs_dev_ioctl(command, (struct autofs_dev_ioctl __user *) u);
+	return (long) err;
+}
+
+#ifdef CONFIG_COMPAT
+static long autofs_dev_ioctl_compat(struct file *file, unsigned int command,
+				    unsigned long u)
+{
+	return autofs_dev_ioctl(file, command, (unsigned long) compat_ptr(u));
+}
+#else
+#define autofs_dev_ioctl_compat NULL
+#endif
+
+static const struct file_operations _dev_ioctl_fops = {
+	.unlocked_ioctl	 = autofs_dev_ioctl,
+	.compat_ioctl = autofs_dev_ioctl_compat,
+	.owner	 = THIS_MODULE,
+	.llseek = noop_llseek,
+};
+
+static struct miscdevice _autofs_dev_ioctl_misc = {
+	.minor		= AUTOFS_MINOR,
+	.name		= AUTOFS_DEVICE_NAME,
+	.fops		= &_dev_ioctl_fops,
+	.mode           = 0644,
+};
+
+MODULE_ALIAS_MISCDEV(AUTOFS_MINOR);
+MODULE_ALIAS("devname:autofs");
+
+/* Register/deregister misc character device */
+int __init autofs_dev_ioctl_init(void)
+{
+	int r;
+
+	r = misc_register(&_autofs_dev_ioctl_misc);
+	if (r) {
+		pr_err("misc_register failed for control device\n");
+		return r;
+	}
+
+	return 0;
+}
+
+void autofs_dev_ioctl_exit(void)
+{
+	misc_deregister(&_autofs_dev_ioctl_misc);
+}
diff --git a/fs/autofs/expire.c b/fs/autofs/expire.c
new file mode 100644
index 000000000000..b332d3f6e730
--- /dev/null
+++ b/fs/autofs/expire.c
@@ -0,0 +1,631 @@
+/*
+ * Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
+ * Copyright 1999-2000 Jeremy Fitzhardinge <jeremy@goop.org>
+ * Copyright 2001-2006 Ian Kent <raven@themaw.net>
+ *
+ * This file is part of the Linux kernel and is made available under
+ * the terms of the GNU General Public License, version 2, or at your
+ * option, any later version, incorporated herein by reference.
+ */
+
+#include "autofs_i.h"
+
+static unsigned long now;
+
+/* Check if a dentry can be expired */
+static inline int autofs_can_expire(struct dentry *dentry,
+				    unsigned long timeout, int do_now)
+{
+	struct autofs_info *ino = autofs_dentry_ino(dentry);
+
+	/* dentry in the process of being deleted */
+	if (ino == NULL)
+		return 0;
+
+	if (!do_now) {
+		/* Too young to die */
+		if (!timeout || time_after(ino->last_used + timeout, now))
+			return 0;
+	}
+	return 1;
+}
+
+/* Check a mount point for busyness */
+static int autofs_mount_busy(struct vfsmount *mnt, struct dentry *dentry)
+{
+	struct dentry *top = dentry;
+	struct path path = {.mnt = mnt, .dentry = dentry};
+	int status = 1;
+
+	pr_debug("dentry %p %pd\n", dentry, dentry);
+
+	path_get(&path);
+
+	if (!follow_down_one(&path))
+		goto done;
+
+	if (is_autofs_dentry(path.dentry)) {
+		struct autofs_sb_info *sbi = autofs_sbi(path.dentry->d_sb);
+
+		/* This is an autofs submount, we can't expire it */
+		if (autofs_type_indirect(sbi->type))
+			goto done;
+	}
+
+	/* Update the expiry counter if fs is busy */
+	if (!may_umount_tree(path.mnt)) {
+		struct autofs_info *ino;
+
+		ino = autofs_dentry_ino(top);
+		ino->last_used = jiffies;
+		goto done;
+	}
+
+	status = 0;
+done:
+	pr_debug("returning = %d\n", status);
+	path_put(&path);
+	return status;
+}
+
+/*
+ * Calculate and dget next entry in the subdirs list under root.
+ */
+static struct dentry *get_next_positive_subdir(struct dentry *prev,
+					       struct dentry *root)
+{
+	struct autofs_sb_info *sbi = autofs_sbi(root->d_sb);
+	struct list_head *next;
+	struct dentry *q;
+
+	spin_lock(&sbi->lookup_lock);
+	spin_lock(&root->d_lock);
+
+	if (prev)
+		next = prev->d_child.next;
+	else {
+		prev = dget_dlock(root);
+		next = prev->d_subdirs.next;
+	}
+
+cont:
+	if (next == &root->d_subdirs) {
+		spin_unlock(&root->d_lock);
+		spin_unlock(&sbi->lookup_lock);
+		dput(prev);
+		return NULL;
+	}
+
+	q = list_entry(next, struct dentry, d_child);
+
+	spin_lock_nested(&q->d_lock, DENTRY_D_LOCK_NESTED);
+	/* Already gone or negative dentry (under construction) - try next */
+	if (!d_count(q) || !simple_positive(q)) {
+		spin_unlock(&q->d_lock);
+		next = q->d_child.next;
+		goto cont;
+	}
+	dget_dlock(q);
+	spin_unlock(&q->d_lock);
+	spin_unlock(&root-&