add idl4k kernel firmware version 1.13.0.105

kernel/fs/autofs4/Kconfig

@@ -0,0 +1,20 @@
+config AUTOFS4_FS
+	tristate "Kernel automounter version 4 support (also supports v3)"
+	help
+	  The automounter is a tool to automatically mount remote file systems
+	  on demand. This implementation is partially kernel-based to reduce
+	  overhead in the already-mounted case; this is unlike the BSD
+	  automounter (amd), which is a pure user space daemon.
+
+	  To use the automounter you need the user-space tools from
+	  <ftp://ftp.kernel.org/pub/linux/daemons/autofs/v4/>; you also
+	  want to answer Y to "NFS file system support", below.
+
+	  To compile this support as a module, choose M here: the module will be
+	  called autofs4.  You will need to add "alias autofs autofs4" to your
+	  modules configuration file.
+
+	  If you are not a part of a fairly large, distributed network or
+	  don't have a laptop which needs to dynamically reconfigure to the
+	  local network, you probably do not need an automounter, and can say
+	  N here.

kernel/fs/autofs4/Makefile

@@ -0,0 +1,7 @@
+#
+# Makefile for the linux autofs-filesystem routines.
+#
+
+obj-$(CONFIG_AUTOFS4_FS) += autofs4.o
+
+autofs4-objs := init.o inode.o root.o symlink.o waitq.o expire.o dev-ioctl.o

kernel/fs/autofs4/autofs_i.h

@@ -0,0 +1,268 @@
+/* -*- c -*- ------------------------------------------------------------- *
+ *   
+ * linux/fs/autofs/autofs_i.h
+ *
+ *   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_fs4.h>
+#include <linux/auto_dev-ioctl.h>
+#include <linux/mutex.h>
+#include <linux/list.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_IOC_COUNT - 11)
+
+#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 <asm/current.h>
+#include <asm/uaccess.h>
+
+/* #define DEBUG */
+
+#ifdef DEBUG
+#define DPRINTK(fmt, args...)				\
+do {							\
+	printk(KERN_DEBUG "pid %d: %s: " fmt "\n",	\
+		current->pid, __func__, ##args);	\
+} while (0)
+#else
+#define DPRINTK(fmt, args...) do {} while (0)
+#endif
+
+#define AUTOFS_WARN(fmt, args...)			\
+do {							\
+	printk(KERN_WARNING "pid %d: %s: " fmt "\n",	\
+		current->pid, __func__, ##args);	\
+} while (0)
+
+#define AUTOFS_ERROR(fmt, args...)			\
+do {							\
+	printk(KERN_ERR "pid %d: %s: " fmt "\n",	\
+		current->pid, __func__, ##args);	\
+} while (0)
+
+/* 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;
+	struct list_head expiring;
+
+	struct autofs_sb_info *sbi;
+	unsigned long last_used;
+	atomic_t count;
+
+	uid_t uid;
+	gid_t gid;
+
+	mode_t	mode;
+	size_t	size;
+
+	void (*free)(struct autofs_info *);
+	union {
+		const char *symlink;
+	} u;
+};
+
+#define AUTOFS_INF_EXPIRING	(1<<0) /* dentry is in the process of expiring */
+#define AUTOFS_INF_MOUNTPOINT	(1<<1) /* mountpoint status for direct expire */
+
+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;
+	uid_t uid;
+	gid_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;
+	pid_t oz_pgrp;
+	int catatonic;
+	int version;
+	int sub_version;
+	int min_proto;
+	int max_proto;
+	unsigned long exp_timeout;
+	unsigned int type;
+	int reghost_enabled;
+	int needs_reghost;
+	struct super_block *sb;
+	struct mutex wq_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;
+};
+
+static inline struct autofs_sb_info *autofs4_sbi(struct super_block *sb)
+{
+	return (struct autofs_sb_info *)(sb->s_fs_info);
+}
+
+static inline struct autofs_info *autofs4_dentry_ino(struct dentry *dentry)
+{
+	return (struct autofs_info *)(dentry->d_fsdata);
+}
+
+/* autofs4_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 autofs4_oz_mode(struct autofs_sb_info *sbi) {
+	return sbi->catatonic || task_pgrp_nr(current) == sbi->oz_pgrp;
+}
+
+/* Does a dentry have some pending activity? */
+static inline int autofs4_ispending(struct dentry *dentry)
+{
+	struct autofs_info *inf = autofs4_dentry_ino(dentry);
+
+	if (dentry->d_flags & DCACHE_AUTOFS_PENDING)
+		return 1;
+
+	if (inf->flags & AUTOFS_INF_EXPIRING)
+		return 1;
+
+	return 0;
+}
+
+static inline void autofs4_copy_atime(struct file *src, struct file *dst)
+{
+	dst->f_path.dentry->d_inode->i_atime =
+		src->f_path.dentry->d_inode->i_atime;
+	return;
+}
+
+struct inode *autofs4_get_inode(struct super_block *, struct autofs_info *);
+void autofs4_free_ino(struct autofs_info *);
+
+/* Expiration */
+int is_autofs4_dentry(struct dentry *);
+int autofs4_expire_wait(struct dentry *dentry);
+int autofs4_expire_run(struct super_block *, struct vfsmount *,
+			struct autofs_sb_info *,
+			struct autofs_packet_expire __user *);
+int autofs4_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
+			    struct autofs_sb_info *sbi, int when);
+int autofs4_expire_multi(struct super_block *, struct vfsmount *,
+			struct autofs_sb_info *, int __user *);
+struct dentry *autofs4_expire_direct(struct super_block *sb,
+				     struct vfsmount *mnt,
+				     struct autofs_sb_info *sbi, int how);
+struct dentry *autofs4_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 autofs4_symlink_inode_operations;
+extern const struct inode_operations autofs4_dir_inode_operations;
+extern const struct inode_operations autofs4_root_inode_operations;
+extern const struct inode_operations autofs4_indirect_root_inode_operations;
+extern const struct inode_operations autofs4_direct_root_inode_operations;
+extern const struct file_operations autofs4_dir_operations;
+extern const struct file_operations autofs4_root_operations;
+
+/* Initializing function */
+
+int autofs4_fill_super(struct super_block *, void *, int);
+struct autofs_info *autofs4_init_ino(struct autofs_info *, struct autofs_sb_info *sbi, mode_t mode);
+
+/* Queue management functions */
+
+int autofs4_wait(struct autofs_sb_info *,struct dentry *, enum autofs_notify);
+int autofs4_wait_release(struct autofs_sb_info *,autofs_wqt_t,int);
+void autofs4_catatonic_mode(struct autofs_sb_info *);
+
+static inline int autofs4_follow_mount(struct path *path)
+{
+	int res = 0;
+
+	while (d_mountpoint(path->dentry)) {
+		int followed = follow_down(path);
+		if (!followed)
+			break;
+		res = 1;
+	}
+	return res;
+}
+
+static inline u32 autofs4_get_dev(struct autofs_sb_info *sbi)
+{
+	return new_encode_dev(sbi->sb->s_dev);
+}
+
+static inline u64 autofs4_get_ino(struct autofs_sb_info *sbi)
+{
+	return sbi->sb->s_root->d_inode->i_ino;
+}
+
+static inline int simple_positive(struct dentry *dentry)
+{
+	return dentry->d_inode && !d_unhashed(dentry);
+}
+
+static inline int __simple_empty(struct dentry *dentry)
+{
+	struct dentry *child;
+	int ret = 0;
+
+	list_for_each_entry(child, &dentry->d_subdirs, d_u.d_child)
+		if (simple_positive(child))
+			goto out;
+	ret = 1;
+out:
+	return ret;
+}
+
+void autofs4_dentry_release(struct dentry *);
+extern void autofs4_kill_sb(struct super_block *);

kernel/fs/autofs4/dev-ioctl.c

@@ -0,0 +1,765 @@
+/*
+ * 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/compat.h>
+#include <linux/syscalls.h>
+#include <linux/magic.h>
+#include <linux/dcache.h>
+#include <linux/uaccess.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.
+ */
+
+#define AUTOFS_DEV_IOCTL_SIZE	sizeof(struct autofs_dev_ioctl)
+
+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 ((AUTOFS_DEV_IOCTL_VERSION_MAJOR != param->ver_major) ||
+	    (AUTOFS_DEV_IOCTL_VERSION_MINOR < param->ver_minor)) {
+		AUTOFS_WARN("ioctl control interface version mismatch: "
+		     "kernel(%u.%u), user(%u.%u), cmd(%d)",
+		     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, *ads;
+
+	if (copy_from_user(&tmp, in, sizeof(tmp)))
+		return ERR_PTR(-EFAULT);
+
+	if (tmp.size < sizeof(tmp))
+		return ERR_PTR(-EINVAL);
+
+	ads = kmalloc(tmp.size, GFP_KERNEL);
+	if (!ads)
+		return ERR_PTR(-ENOMEM);
+
+	if (copy_from_user(ads, in, tmp.size)) {
+		kfree(ads);
+		return ERR_PTR(-EFAULT);
+	}
+
+	return ads;
+}
+
+static inline void free_dev_ioctl(struct autofs_dev_ioctl *param)
+{
+	kfree(param);
+	return;
+}
+
+/*
+ * 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) {
+		AUTOFS_WARN("invalid device control module version "
+		     "supplied for cmd(0x%08x)", cmd);
+		goto out;
+	}
+
+	if (param->size > sizeof(*param)) {
+		err = invalid_str(param->path, param->size - sizeof(*param));
+		if (err) {
+			AUTOFS_WARN(
+			  "path string terminator missing for cmd(0x%08x)",
+			  cmd);
+			goto out;
+		}
+
+		err = check_name(param->path);
+		if (err) {
+			AUTOFS_WARN("invalid path supplied for cmd(0x%08x)",
+				    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 = f->f_path.dentry->d_inode;
+		sbi = autofs4_sbi(inode->i_sb);
+	}
+	return sbi;
+}
+
+/* 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;
+}
+
+static int find_autofs_mount(const char *pathname,
+			     struct path *res,
+			     int test(struct path *path, void *data),
+			     void *data)
+{
+	struct path path;
+	int err = kern_path(pathname, 0, &path);
+	if (err)
+		return err;
+	err = -ENOENT;
+	while (path.dentry == path.mnt->mnt_root) {
+		if (path.mnt->mnt_sb->s_magic == AUTOFS_SUPER_MAGIC) {
+			if (test(&path, data)) {
+				path_get(&path);
+				if (!err) /* already found some */
+					path_put(res);
+				*res = path;
+				err = 0;
+			}
+		}
+		if (!follow_up(&path))
+			break;
+	}
+	path_put(&path);
+	return err;
+}
+
+static int test_by_dev(struct path *path, void *p)
+{
+	return path->mnt->mnt_sb->s_dev == *(dev_t *)p;
+}
+
+static int test_by_type(struct path *path, void *p)
+{
+	struct autofs_info *ino = autofs4_dentry_ino(path->dentry);
+	return ino && ino->sbi->type & *(unsigned *)p;
+}
+
+static void autofs_dev_ioctl_fd_install(unsigned int fd, struct file *file)
+{
+	struct files_struct *files = current->files;
+	struct fdtable *fdt;
+
+	spin_lock(&files->file_lock);
+	fdt = files_fdtable(files);
+	BUG_ON(fdt->fd[fd] != NULL);
+	rcu_assign_pointer(fdt->fd[fd], file);
+	FD_SET(fd, fdt->close_on_exec);
+	spin_unlock(&files->file_lock);
+}
+
+
+/*
+ * 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();
+	if (likely(fd >= 0)) {
+		struct file *filp;
+		struct path path;
+
+		err = find_autofs_mount(name, &path, test_by_dev, &devid);
+		if (err)
+			goto out;
+
+		/*
+		 * Find autofs super block that has the device number
+		 * corresponding to the autofs fs we want to open.
+		 */
+
+		filp = dentry_open(path.dentry, path.mnt, O_RDONLY,
+				   current_cred());
+		if (IS_ERR(filp)) {
+			err = PTR_ERR(filp);
+			goto out;
+		}
+
+		autofs_dev_ioctl_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 sys_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 autofs4_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 ? param->fail.status : -ENOENT;
+	return autofs4_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;
+
+	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 = fget(pipefd);
+		if (!pipe->f_op || !pipe->f_op->write) {
+			err = -EPIPE;
+			fput(pipe);
+			goto out;
+		}
+		sbi->oz_pgrp = task_pgrp_nr(current);
+		sbi->pipefd = pipefd;
+		sbi->pipe = pipe;
+		sbi->catatonic = 0;
+	}
+out:
+	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)
+{
+	autofs4_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 <= sizeof(*param)) {
+		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 = autofs4_dentry_ino(path.dentry);
+	if (ino) {
+		err = 0;
+		autofs4_expire_wait(path.dentry);
+		spin_lock(&sbi->fs_lock);
+		param->requester.uid = ino->uid;
+		param->requester.gid = 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 autofs4_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 nameidata of 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 nameidata 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 <= sizeof(*param)) {
+		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(name, LOOKUP_FOLLOW, &path);
+		else
+			err = find_autofs_mount(name, &path, test_by_type, &type);
+		if (err)
+			goto out;
+		devid = new_encode_dev(path.mnt->mnt_sb->s_dev);
+		err = 0;
+		if (path.dentry->d_inode &&
+		    path.mnt->mnt_root == path.dentry) {
+			err = 1;
+			magic = path.dentry->d_inode->i_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 = have_submounts(path.dentry);
+
+		if (path.mnt->mnt_mountpoint != path.mnt->mnt_root) {
+			if (follow_down(&path))
+				magic = path.mnt->mnt_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 struct {
+		int cmd;
+		ioctl_fn fn;
+	} _ioctls[] = {
+		{cmd_idx(AUTOFS_DEV_IOCTL_VERSION_CMD), NULL},
+		{cmd_idx(AUTOFS_DEV_IOCTL_PROTOVER_CMD),
+			 autofs_dev_ioctl_protover},
+		{cmd_idx(AUTOFS_DEV_IOCTL_PROTOSUBVER_CMD),
+			 autofs_dev_ioctl_protosubver},
+		{cmd_idx(AUTOFS_DEV_IOCTL_OPENMOUNT_CMD),
+			 autofs_dev_ioctl_openmount},
+		{cmd_idx(AUTOFS_DEV_IOCTL_CLOSEMOUNT_CMD),
+			 autofs_dev_ioctl_closemount},
+		{cmd_idx(AUTOFS_DEV_IOCTL_READY_CMD),
+			 autofs_dev_ioctl_ready},
+		{cmd_idx(AUTOFS_DEV_IOCTL_FAIL_CMD),
+			 autofs_dev_ioctl_fail},
+		{cmd_idx(AUTOFS_DEV_IOCTL_SETPIPEFD_CMD),
+			 autofs_dev_ioctl_setpipefd},
+		{cmd_idx(AUTOFS_DEV_IOCTL_CATATONIC_CMD),
+			 autofs_dev_ioctl_catatonic},
+		{cmd_idx(AUTOFS_DEV_IOCTL_TIMEOUT_CMD),
+			 autofs_dev_ioctl_timeout},
+		{cmd_idx(AUTOFS_DEV_IOCTL_REQUESTER_CMD),
+			 autofs_dev_ioctl_requester},
+		{cmd_idx(AUTOFS_DEV_IOCTL_EXPIRE_CMD),
+			 autofs_dev_ioctl_expire},
+		{cmd_idx(AUTOFS_DEV_IOCTL_ASKUMOUNT_CMD),
+			 autofs_dev_ioctl_askumount},
+		{cmd_idx(AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD),
+			 autofs_dev_ioctl_ismountpoint}
+	};
+	unsigned int idx = cmd_idx(cmd);
+
+	return (idx >= ARRAY_SIZE(_ioctls)) ? NULL : _ioctls[idx].fn;
+}
+
+/* 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;
+
+	/* only root can play with this */
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	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;
+	}
+
+	/* 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;
+
+	/* The validate routine above always sets the version */
+	if (cmd == AUTOFS_DEV_IOCTL_VERSION_CMD)
+		goto done;
+
+	fn = lookup_dev_ioctl(cmd);
+	if (!fn) {
+		AUTOFS_WARN("unknown command 0x%08x", command);
+		return -ENOTTY;
+	}
+
+	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.
+	 */
+	if (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;
+		}
+
+		if (!fp->f_op) {
+			err = -ENOTTY;
+			fput(fp);
+			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 (!autofs4_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);
+done:
+	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, uint command, ulong 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, uint command, ulong u)
+{
+	return (long) autofs_dev_ioctl(file, command, (ulong) 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,
+};
+
+static struct miscdevice _autofs_dev_ioctl_misc = {
+	.minor 		= MISC_DYNAMIC_MINOR,
+	.name  		= AUTOFS_DEVICE_NAME,
+	.fops  		= &_dev_ioctl_fops
+};
+
+/* Register/deregister misc character device */
+int autofs_dev_ioctl_init(void)
+{
+	int r;
+
+	r = misc_register(&_autofs_dev_ioctl_misc);
+	if (r) {
+		AUTOFS_ERROR("misc_register failed for control device");
+		return r;
+	}
+
+	return 0;
+}
+
+void autofs_dev_ioctl_exit(void)
+{
+	misc_deregister(&_autofs_dev_ioctl_misc);
+	return;
+}
+

kernel/fs/autofs4/expire.c

@@ -0,0 +1,526 @@
+/* -*- c -*- --------------------------------------------------------------- *
+ *
+ * linux/fs/autofs/expire.c
+ *
+ *  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 autofs4_can_expire(struct dentry *dentry,
+					unsigned long timeout, int do_now)
+{
+	struct autofs_info *ino = autofs4_dentry_ino(dentry);
+
+	/* dentry in the process of being deleted */
+	if (ino == NULL)
+		return 0;
+
+	/* No point expiring a pending mount */
+	if (dentry->d_flags & DCACHE_AUTOFS_PENDING)
+		return 0;
+
+	if (!do_now) {
+		/* Too young to die */
+		if (!timeout || time_after(ino->last_used + timeout, now))
+			return 0;
+
+		/* update last_used here :-
+		   - obviously makes sense if it is in use now
+		   - less obviously, prevents rapid-fire expire
+		     attempts if expire fails the first time */
+		ino->last_used = now;
+	}
+	return 1;
+}
+
+/* Check a mount point for busyness */
+static int autofs4_mount_busy(struct vfsmount *mnt, struct dentry *dentry)
+{
+	struct dentry *top = dentry;
+	struct path path = {.mnt = mnt, .dentry = dentry};
+	int status = 1;
+
+	DPRINTK("dentry %p %.*s",
+		dentry, (int)dentry->d_name.len, dentry->d_name.name);
+
+	path_get(&path);
+
+	if (!follow_down(&path))
+		goto done;
+
+	if (is_autofs4_dentry(path.dentry)) {
+		struct autofs_sb_info *sbi = autofs4_sbi(path.dentry->d_sb);
+
+		/* This is an autofs submount, we can't expire it */
+		if (autofs_type_indirect(sbi->type))
+			goto done;
+
+		/*
+		 * Otherwise it's an offset mount and we need to check
+		 * if we can umount its mount, if there is one.
+		 */
+		if (!d_mountpoint(path.dentry)) {
+			status = 0;
+			goto done;
+		}
+	}
+
+	/* Update the expiry counter if fs is busy */
+	if (!may_umount_tree(path.mnt)) {
+		struct autofs_info *ino = autofs4_dentry_ino(top);
+		ino->last_used = jiffies;
+		goto done;
+	}
+
+	status = 0;
+done:
+	DPRINTK("returning = %d", status);
+	path_put(&path);
+	return status;
+}
+
+/*
+ * Calculate next entry in top down tree traversal.
+ * From next_mnt in namespace.c - elegant.
+ */
+static struct dentry *next_dentry(struct dentry *p, struct dentry *root)
+{
+	struct list_head *next = p->d_subdirs.next;
+
+	if (next == &p->d_subdirs) {
+		while (1) {
+			if (p == root)
+				return NULL;
+			next = p->d_u.d_child.next;
+			if (next != &p->d_parent->d_subdirs)
+				break;
+			p = p->d_parent;
+		}
+	}
+	return list_entry(next, struct dentry, d_u.d_child);
+}
+
+/*
+ * Check a direct mount point for busyness.
+ * Direct mounts have similar expiry semantics to tree mounts.
+ * The tree is not busy iff no mountpoints are busy and there are no
+ * autofs submounts.
+ */
+static int autofs4_direct_busy(struct vfsmount *mnt,
+				struct dentry *top,
+				unsigned long timeout,
+				int do_now)
+{
+	DPRINTK("top %p %.*s",
+		top, (int) top->d_name.len, top->d_name.name);
+
+	/* If it's busy update the expiry counters */
+	if (!may_umount_tree(mnt)) {
+		struct autofs_info *ino = autofs4_dentry_ino(top);
+		if (ino)
+			ino->last_used = jiffies;
+		return 1;
+	}
+
+	/* Timeout of a direct mount is determined by its top dentry */
+	if (!autofs4_can_expire(top, timeout, do_now))
+		return 1;
+
+	return 0;
+}
+
+/* Check a directory tree of mount points for busyness
+ * The tree is not busy iff no mountpoints are busy
+ */
+static int autofs4_tree_busy(struct vfsmount *mnt,
+	       		     struct dentry *top,
+			     unsigned long timeout,
+			     int do_now)
+{
+	struct autofs_info *top_ino = autofs4_dentry_ino(top);
+	struct dentry *p;
+
+	DPRINTK("top %p %.*s",
+		top, (int)top->d_name.len, top->d_name.name);
+
+	/* Negative dentry - give up */
+	if (!simple_positive(top))
+		return 1;
+
+	spin_lock(&dcache_lock);
+	for (p = top; p; p = next_dentry(p, top)) {
+		/* Negative dentry - give up */
+		if (!simple_positive(p))
+			continue;
+
+		DPRINTK("dentry %p %.*s",
+			p, (int) p->d_name.len, p->d_name.name);
+
+		p = dget(p);
+		spin_unlock(&dcache_lock);
+
+		/*
+		 * Is someone visiting anywhere in the subtree ?
+		 * If there's no mount we need to check the usage
+		 * count for the autofs dentry.
+		 * If the fs is busy update the expiry counter.
+		 */
+		if (d_mountpoint(p)) {
+			if (autofs4_mount_busy(mnt, p)) {
+				top_ino->last_used = jiffies;
+				dput(p);
+				return 1;
+			}
+		} else {
+			struct autofs_info *ino = autofs4_dentry_ino(p);
+			unsigned int ino_count = atomic_read(&ino->count);
+
+			/*
+			 * Clean stale dentries below that have not been
+			 * invalidated after a mount fail during lookup
+			 */
+			d_invalidate(p);
+
+			/* allow for dget above and top is already dgot */
+			if (p == top)
+				ino_count += 2;
+			else
+				ino_count++;
+
+			if (atomic_read(&p->d_count) > ino_count) {
+				top_ino->last_used = jiffies;
+				dput(p);
+				return 1;
+			}
+		}
+		dput(p);
+		spin_lock(&dcache_lock);
+	}
+	spin_unlock(&dcache_lock);
+
+	/* Timeout of a tree mount is ultimately determined by its top dentry */
+	if (!autofs4_can_expire(top, timeout, do_now))
+		return 1;
+
+	return 0;
+}
+
+static struct dentry *autofs4_check_leaves(struct vfsmount *mnt,
+					   struct dentry *parent,
+					   unsigned long timeout,
+					   int do_now)
+{
+	struct dentry *p;
+
+	DPRINTK("parent %p %.*s",
+		parent, (int)parent->d_name.len, parent->d_name.name);
+
+	spin_lock(&dcache_lock);
+	for (p = parent; p; p = next_dentry(p, parent)) {
+		/* Negative dentry - give up */
+		if (!simple_positive(p))
+			continue;
+
+		DPRINTK("dentry %p %.*s",
+			p, (int) p->d_name.len, p->d_name.name);
+
+		p = dget(p);
+		spin_unlock(&dcache_lock);
+
+		if (d_mountpoint(p)) {
+			/* Can we umount this guy */
+			if (autofs4_mount_busy(mnt, p))
+				goto cont;
+
+			/* Can we expire this guy */
+			if (autofs4_can_expire(p, timeout, do_now))
+				return p;
+		}
+cont:
+		dput(p);
+		spin_lock(&dcache_lock);
+	}
+	spin_unlock(&dcache_lock);
+	return NULL;
+}
+
+/* Check if we can expire a direct mount (possibly a tree) */
+struct dentry *autofs4_expire_direct(struct super_block *sb,
+				     struct vfsmount *mnt,
+				     struct autofs_sb_info *sbi,
+				     int how)
+{
+	unsigned long timeout;
+	struct dentry *root = dget(sb->s_root);
+	int do_now = how & AUTOFS_EXP_IMMEDIATE;
+
+	if (!root)
+		return NULL;
+
+	now = jiffies;
+	timeout = sbi->exp_timeout;
+
+	spin_lock(&sbi->fs_lock);
+	if (!autofs4_direct_busy(mnt, root, timeout, do_now)) {
+		struct autofs_info *ino = autofs4_dentry_ino(root);
+		if (d_mountpoint(root)) {
+			ino->flags |= AUTOFS_INF_MOUNTPOINT;
+			root->d_mounted--;
+		}
+		ino->flags |= AUTOFS_INF_EXPIRING;
+		init_completion(&ino->expire_complete);
+		spin_unlock(&sbi->fs_lock);
+		return root;
+	}
+	spin_unlock(&sbi->fs_lock);
+	dput(root);
+
+	return NULL;
+}
+
+/*
+ * Find an eligible tree to time-out
+ * A tree is eligible if :-
+ *  - it is unused by any user process
+ *  - it has been unused for exp_timeout time
+ */
+struct dentry *autofs4_expire_indirect(struct super_block *sb,
+				       struct vfsmount *mnt,
+				       struct autofs_sb_info *sbi,
+				       int how)
+{
+	unsigned long timeout;
+	struct dentry *root = sb->s_root;
+	struct dentry *expired = NULL;
+	struct list_head *next;
+	int do_now = how & AUTOFS_EXP_IMMEDIATE;
+	int exp_leaves = how & AUTOFS_EXP_LEAVES;
+	struct autofs_info *ino;
+	unsigned int ino_count;
+
+	if (!root)
+		return NULL;
+
+	now = jiffies;
+	timeout = sbi->exp_timeout;
+
+	spin_lock(&dcache_lock);
+	next = root->d_subdirs.next;
+
+	/* On exit from the loop expire is set to a dgot dentry
+	 * to expire or it's NULL */
+	while ( next != &root->d_subdirs ) {
+		struct dentry *dentry = list_entry(next, struct dentry, d_u.d_child);
+
+		/* Negative dentry - give up */
+		if (!simple_positive(dentry)) {
+			next = next->next;
+			continue;
+		}
+
+		dentry = dget(dentry);
+		spin_unlock(&dcache_lock);
+
+		spin_lock(&sbi->fs_lock);
+		ino = autofs4_dentry_ino(dentry);
+
+		/*
+		 * Case 1: (i) indirect mount or top level pseudo direct mount
+		 *	   (autofs-4.1).
+		 *	   (ii) indirect mount with offset mount, check the "/"
+		 *	   offset (autofs-5.0+).
+		 */
+		if (d_mountpoint(dentry)) {
+			DPRINTK("checking mountpoint %p %.*s",
+				dentry, (int)dentry->d_name.len, dentry->d_name.name);
+
+			/* Path walk currently on this dentry? */
+			ino_count = atomic_read(&ino->count) + 2;
+			if (atomic_read(&dentry->d_count) > ino_count)
+				goto next;
+
+			/* Can we umount this guy */
+			if (autofs4_mount_busy(mnt, dentry))
+				goto next;
+
+			/* Can we expire this guy */
+			if (autofs4_can_expire(dentry, timeout, do_now)) {
+				expired = dentry;
+				goto found;
+			}
+			goto next;
+		}
+
+		if (simple_empty(dentry))
+			goto next;
+
+		/* Case 2: tree mount, expire iff entire tree is not busy */
+		if (!exp_leaves) {
+			/* Path walk currently on this dentry? */
+			ino_count = atomic_read(&ino->count) + 1;
+			if (atomic_read(&dentry->d_count) > ino_count)
+				goto next;
+
+			if (!autofs4_tree_busy(mnt, dentry, timeout, do_now)) {
+				expired = dentry;
+				goto found;
+			}
+		/*
+		 * Case 3: pseudo direct mount, expire individual leaves
+		 *	   (autofs-4.1).
+		 */
+		} else {
+			/* Path walk currently on this dentry? */
+			ino_count = atomic_read(&ino->count) + 1;
+			if (atomic_read(&dentry->d_count) > ino_count)
+				goto next;
+
+			expired = autofs4_check_leaves(mnt, dentry, timeout, do_now);
+			if (expired) {
+				dput(dentry);
+				goto found;
+			}
+		}
+next:
+		spin_unlock(&sbi->fs_lock);
+		dput(dentry);
+		spin_lock(&dcache_lock);
+		next = next->next;
+	}
+	spin_unlock(&dcache_lock);
+	return NULL;
+
+found:
+	DPRINTK("returning %p %.*s",
+		expired, (int)expired->d_name.len, expired->d_name.name);
+	ino = autofs4_dentry_ino(expired);
+	ino->flags |= AUTOFS_INF_EXPIRING;
+	init_completion(&ino->expire_complete);
+	spin_unlock(&sbi->fs_lock);
+	spin_lock(&dcache_lock);
+	list_move(&expired->d_parent->d_subdirs, &expired->d_u.d_child);
+	spin_unlock(&dcache_lock);
+	return expired;
+}
+
+int autofs4_expire_wait(struct dentry *dentry)
+{
+	struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
+	struct autofs_info *ino = autofs4_dentry_ino(dentry);
+	int status;
+
+	/* Block on any pending expire */
+	spin_lock(&sbi->fs_lock);
+	if (ino->flags & AUTOFS_INF_EXPIRING) {
+		spin_unlock(&sbi->fs_lock);
+
+		DPRINTK("waiting for expire %p name=%.*s",
+			 dentry, dentry->d_name.len, dentry->d_name.name);
+
+		status = autofs4_wait(sbi, dentry, NFY_NONE);
+		wait_for_completion(&ino->expire_complete);
+
+		DPRINTK("expire done status=%d", status);
+
+		if (d_unhashed(dentry))
+			return -EAGAIN;
+
+		return status;
+	}
+	spin_unlock(&sbi->fs_lock);
+
+	return 0;
+}
+
+/* Perform an expiry operation */
+int autofs4_expire_run(struct super_block *sb,
+		      struct vfsmount *mnt,
+		      struct autofs_sb_info *sbi,
+		      struct autofs_packet_expire __user *pkt_p)
+{
+	struct autofs_packet_expire pkt;
+	struct autofs_info *ino;
+	struct dentry *dentry;
+	int ret = 0;
+
+	memset(&pkt,0,sizeof pkt);
+
+	pkt.hdr.proto_version = sbi->version;
+	pkt.hdr.type = autofs_ptype_expire;
+
+	if ((dentry = autofs4_expire_indirect(sb, mnt, sbi, 0)) == NULL)
+		return -EAGAIN;
+
+	pkt.len = dentry->d_name.len;
+	memcpy(pkt.name, dentry->d_name.name, pkt.len);
+	pkt.name[pkt.len] = '\0';
+	dput(dentry);
+
+	if ( copy_to_user(pkt_p, &pkt, sizeof(struct autofs_packet_expire)) )
+		ret = -EFAULT;
+
+	spin_lock(&sbi->fs_lock);
+	ino = autofs4_dentry_ino(dentry);
+	ino->flags &= ~AUTOFS_INF_EXPIRING;
+	complete_all(&ino->expire_complete);
+	spin_unlock(&sbi->fs_lock);
+
+	return ret;
+}
+
+int autofs4_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
+			    struct autofs_sb_info *sbi, int when)
+{
+	struct dentry *dentry;
+	int ret = -EAGAIN;
+
+	if (autofs_type_trigger(sbi->type))
+		dentry = autofs4_expire_direct(sb, mnt, sbi, when);
+	else
+		dentry = autofs4_expire_indirect(sb, mnt, sbi, when);
+
+	if (dentry) {
+		struct autofs_info *ino = autofs4_dentry_ino(dentry);
+
+		/* This is synchronous because it makes the daemon a
+                   little easier */
+		ret = autofs4_wait(sbi, dentry, NFY_EXPIRE);
+
+		spin_lock(&sbi->fs_lock);
+		if (ino->flags & AUTOFS_INF_MOUNTPOINT) {
+			sb->s_root->d_mounted++;
+			ino->flags &= ~AUTOFS_INF_MOUNTPOINT;
+		}
+		ino->flags &= ~AUTOFS_INF_EXPIRING;
+		complete_all(&ino->expire_complete);
+		spin_unlock(&sbi->fs_lock);
+		dput(dentry);
+	}
+
+	return ret;
+}
+
+/* Call repeatedly until it returns -EAGAIN, meaning there's nothing
+   more to be done */
+int autofs4_expire_multi(struct super_block *sb, struct vfsmount *mnt,
+			struct autofs_sb_info *sbi, int __user *arg)
+{
+	int do_now = 0;
+
+	if (arg && get_user(do_now, arg))
+		return -EFAULT;
+
+	return autofs4_do_expire_multi(sb, mnt, sbi, do_now);
+}
+

kernel/fs/autofs4/init.c

@@ -0,0 +1,51 @@
+/* -*- c -*- --------------------------------------------------------------- *
+ *
+ * linux/fs/autofs/init.c
+ *
+ *  Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
+ *
+ * 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/init.h>
+#include "autofs_i.h"
+
+static int autofs_get_sb(struct file_system_type *fs_type,
+	int flags, const char *dev_name, void *data, struct vfsmount *mnt)
+{
+	return get_sb_nodev(fs_type, flags, data, autofs4_fill_super, mnt);
+}
+
+static struct file_system_type autofs_fs_type = {
+	.owner		= THIS_MODULE,
+	.name		= "autofs",
+	.get_sb		= autofs_get_sb,
+	.kill_sb	= autofs4_kill_sb,
+};
+
+static int __init init_autofs4_fs(void)
+{
+	int err;
+
+	err = register_filesystem(&autofs_fs_type);
+	if (err)
+		return err;
+
+	autofs_dev_ioctl_init();
+
+	return err;
+}
+
+static void __exit exit_autofs4_fs(void)
+{
+	autofs_dev_ioctl_exit();
+	unregister_filesystem(&autofs_fs_type);
+}
+
+module_init(init_autofs4_fs) 
+module_exit(exit_autofs4_fs)
+MODULE_LICENSE("GPL");

kernel/fs/autofs4/inode.c

@@ -0,0 +1,471 @@
+/* -*- c -*- --------------------------------------------------------------- *
+ *
+ * linux/fs/autofs/inode.c
+ *
+ *  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.
+ *
+ * ------------------------------------------------------------------------- */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/file.h>
+#include <linux/seq_file.h>
+#include <linux/pagemap.h>
+#include <linux/parser.h>
+#include <linux/bitops.h>
+#include <linux/magic.h>
+#include "autofs_i.h"
+#include <linux/module.h>
+
+static void ino_lnkfree(struct autofs_info *ino)
+{
+	if (ino->u.symlink) {
+		kfree(ino->u.symlink);
+		ino->u.symlink = NULL;
+	}
+}
+
+struct autofs_info *autofs4_init_ino(struct autofs_info *ino,
+				     struct autofs_sb_info *sbi, mode_t mode)
+{
+	int reinit = 1;
+
+	if (ino == NULL) {
+		reinit = 0;
+		ino = kmalloc(sizeof(*ino), GFP_KERNEL);
+	}
+
+	if (ino == NULL)
+		return NULL;
+
+	if (!reinit) {
+		ino->flags = 0;
+		ino->inode = NULL;
+		ino->dentry = NULL;
+		ino->size = 0;
+		INIT_LIST_HEAD(&ino->active);
+		INIT_LIST_HEAD(&ino->expiring);
+		atomic_set(&ino->count, 0);
+	}
+
+	ino->uid = 0;
+	ino->gid = 0;
+	ino->mode = mode;
+	ino->last_used = jiffies;
+
+	ino->sbi = sbi;
+
+	if (reinit && ino->free)
+		(ino->free)(ino);
+
+	memset(&ino->u, 0, sizeof(ino->u));
+
+	ino->free = NULL;
+
+	if (S_ISLNK(mode))
+		ino->free = ino_lnkfree;
+
+	return ino;
+}
+
+void autofs4_free_ino(struct autofs_info *ino)
+{
+	struct autofs_info *p_ino;
+
+	if (ino->dentry) {
+		ino->dentry->d_fsdata = NULL;
+		if (ino->dentry->d_inode) {
+			struct dentry *parent = ino->dentry->d_parent;
+			if (atomic_dec_and_test(&ino->count)) {
+				p_ino = autofs4_dentry_ino(parent);
+				if (p_ino && parent != ino->dentry)
+					atomic_dec(&p_ino->count);
+			}
+			dput(ino->dentry);
+		}
+		ino->dentry = NULL;
+	}
+	if (ino->free)
+		(ino->free)(ino);
+	kfree(ino);
+}
+
+/*
+ * Deal with the infamous "Busy inodes after umount ..." message.
+ *
+ * Clean up the dentry tree. This happens with autofs if the user
+ * space program goes away due to a SIGKILL, SIGSEGV etc.
+ */
+static void autofs4_force_release(struct autofs_sb_info *sbi)
+{
+	struct dentry *this_parent = sbi->sb->s_root;
+	struct list_head *next;
+
+	if (!sbi->sb->s_root)
+		return;
+
+	spin_lock(&dcache_lock);
+repeat:
+	next = this_parent->d_subdirs.next;
+resume:
+	while (next != &this_parent->d_subdirs) {
+		struct dentry *dentry = list_entry(next, struct dentry, d_u.d_child);
+
+		/* Negative dentry - don`t care */
+		if (!simple_positive(dentry)) {
+			next = next->next;
+			continue;
+		}
+
+		if (!list_empty(&dentry->d_subdirs)) {
+			this_parent = dentry;
+			goto repeat;
+		}
+
+		next = next->next;
+		spin_unlock(&dcache_lock);
+
+		DPRINTK("dentry %p %.*s",
+			dentry, (int)dentry->d_name.len, dentry->d_name.name);
+
+		dput(dentry);
+		spin_lock(&dcache_lock);
+	}
+
+	if (this_parent != sbi->sb->s_root) {
+		struct dentry *dentry = this_parent;
+
+		next = this_parent->d_u.d_child.next;
+		this_parent = this_parent->d_parent;
+		spin_unlock(&dcache_lock);
+		DPRINTK("parent dentry %p %.*s",
+			dentry, (int)dentry->d_name.len, dentry->d_name.name);
+		dput(dentry);
+		spin_lock(&dcache_lock);
+		goto resume;
+	}
+	spin_unlock(&dcache_lock);
+}
+
+void autofs4_kill_sb(struct super_block *sb)
+{
+	struct autofs_sb_info *sbi = autofs4_sbi(sb);
+
+	/*
+	 * In the event of a failure in get_sb_nodev the superblock
+	 * info is not present so nothing else has been setup, so
+	 * just call kill_anon_super when we are called from
+	 * deactivate_super.
+	 */
+	if (!sbi)
+		goto out_kill_sb;
+
+	/* Free wait queues, close pipe */
+	autofs4_catatonic_mode(sbi);
+
+	/* Clean up and release dangling references */
+	autofs4_force_release(sbi);
+
+	sb->s_fs_info = NULL;
+	kfree(sbi);
+
+out_kill_sb:
+	DPRINTK("shutting down");
+	kill_anon_super(sb);
+}
+
+static int autofs4_show_options(struct seq_file *m, struct vfsmount *mnt)
+{
+	struct autofs_sb_info *sbi = autofs4_sbi(mnt->mnt_sb);
+	struct inode *root_inode = mnt->mnt_sb->s_root->d_inode;
+
+	if (!sbi)
+		return 0;
+
+	seq_printf(m, ",fd=%d", sbi->pipefd);
+	if (root_inode->i_uid != 0)
+		seq_printf(m, ",uid=%u", root_inode->i_uid);
+	if (root_inode->i_gid != 0)
+		seq_printf(m, ",gid=%u", root_inode->i_gid);
+	seq_printf(m, ",pgrp=%d", sbi->oz_pgrp);
+	seq_printf(m, ",timeout=%lu", sbi->exp_timeout/HZ);
+	seq_printf(m, ",minproto=%d", sbi->min_proto);
+	seq_printf(m, ",maxproto=%d", sbi->max_proto);
+
+	if (autofs_type_offset(sbi->type))
+		seq_printf(m, ",offset");
+	else if (autofs_type_direct(sbi->type))
+		seq_printf(m, ",direct");
+	else
+		seq_printf(m, ",indirect");
+
+	return 0;
+}
+
+static const struct super_operations autofs4_sops = {
+	.statfs		= simple_statfs,
+	.show_options	= autofs4_show_options,
+};
+
+enum {Opt_err, Opt_fd, Opt_uid, Opt_gid, Opt_pgrp, Opt_minproto, Opt_maxproto,
+	Opt_indirect, Opt_direct, Opt_offset};
+
+static const match_table_t tokens = {
+	{Opt_fd, "fd=%u"},
+	{Opt_uid, "uid=%u"},
+	{Opt_gid, "gid=%u"},
+	{Opt_pgrp, "pgrp=%u"},
+	{Opt_minproto, "minproto=%u"},
+	{Opt_maxproto, "maxproto=%u"},
+	{Opt_indirect, "indirect"},
+	{Opt_direct, "direct"},
+	{Opt_offset, "offset"},
+	{Opt_err, NULL}
+};
+
+static int parse_options(char *options, int *pipefd, uid_t *uid, gid_t *gid,
+		pid_t *pgrp, unsigned int *type, int *minproto, int *maxproto)
+{
+	char *p;
+	substring_t args[MAX_OPT_ARGS];
+	int option;
+
+	*uid = current_uid();
+	*gid = current_gid();
+	*pgrp = task_pgrp_nr(current);
+
+	*minproto = AUTOFS_MIN_PROTO_VERSION;
+	*maxproto = AUTOFS_MAX_PROTO_VERSION;
+
+	*pipefd = -1;
+
+	if (!options)
+		return 1;
+
+	while ((p = strsep(&options, ",")) != NULL) {
+		int token;
+		if (!*p)
+			continue;
+
+		token = match_token(p, tokens, args);
+		switch (token) {
+		case Opt_fd:
+			if (match_int(args, pipefd))
+				return 1;
+			break;
+		case Opt_uid:
+			if (match_int(args, &option))
+				return 1;
+			*uid = option;
+			break;
+		case Opt_gid:
+			if (match_int(args, &option))
+				return 1;
+			*gid = option;
+			break;
+		case Opt_pgrp:
+			if (match_int(args, &option))
+				return 1;
+			*pgrp = option;
+			break;
+		case Opt_minproto:
+			if (match_int(args, &option))
+				return 1;
+			*minproto = option;
+			break;
+		case Opt_maxproto:
+			if (match_int(args, &option))
+				return 1;
+			*maxproto = option;
+			break;
+		case Opt_indirect:
+			set_autofs_type_indirect(type);
+			break;
+		case Opt_direct:
+			set_autofs_type_direct(type);
+			break;
+		case Opt_offset:
+			set_autofs_type_offset(type);
+			break;
+		default:
+			return 1;
+		}
+	}
+	return (*pipefd < 0);
+}
+
+static struct autofs_info *autofs4_mkroot(struct autofs_sb_info *sbi)
+{
+	struct autofs_info *ino;
+
+	ino = autofs4_init_ino(NULL, sbi, S_IFDIR | 0755);
+	if (!ino)
+		return NULL;
+
+	return ino;
+}
+
+static const struct dentry_operations autofs4_sb_dentry_operations = {
+	.d_release      = autofs4_dentry_release,
+};
+
+int autofs4_fill_super(struct super_block *s, void *data, int silent)
+{
+	struct inode * root_inode;
+	struct dentry * root;
+	struct file * pipe;
+	int pipefd;
+	struct autofs_sb_info *sbi;
+	struct autofs_info *ino;
+
+	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
+	if (!sbi)
+		goto fail_unlock;
+	DPRINTK("starting up, sbi = %p",sbi);
+
+	s->s_fs_info = sbi;
+	sbi->magic = AUTOFS_SBI_MAGIC;
+	sbi->pipefd = -1;
+	sbi->pipe = NULL;
+	sbi->catatonic = 1;
+	sbi->exp_timeout = 0;
+	sbi->oz_pgrp = task_pgrp_nr(current);
+	sbi->sb = s;
+	sbi->version = 0;
+	sbi->sub_version = 0;
+	set_autofs_type_indirect(&sbi->type);
+	sbi->min_proto = 0;
+	sbi->max_proto = 0;
+	mutex_init(&sbi->wq_mutex);
+	spin_lock_init(&sbi->fs_lock);
+	sbi->queues = NULL;
+	spin_lock_init(&sbi->lookup_lock);
+	INIT_LIST_HEAD(&sbi->active_list);
+	INIT_LIST_HEAD(&sbi->expiring_list);
+	s->s_blocksize = 1024;
+	s->s_blocksize_bits = 10;
+	s->s_magic = AUTOFS_SUPER_MAGIC;
+	s->s_op = &autofs4_sops;
+	s->s_time_gran = 1;
+
+	/*
+	 * Get the root inode and dentry, but defer checking for errors.
+	 */
+	ino = autofs4_mkroot(sbi);
+	if (!ino)
+		goto fail_free;
+	root_inode = autofs4_get_inode(s, ino);
+	if (!root_inode)
+		goto fail_ino;
+
+	root = d_alloc_root(root_inode);
+	if (!root)
+		goto fail_iput;
+	pipe = NULL;
+
+	root->d_op = &autofs4_sb_dentry_operations;
+	root->d_fsdata = ino;
+
+	/* Can this call block? */
+	if (parse_options(data, &pipefd, &root_inode->i_uid, &root_inode->i_gid,
+				&sbi->oz_pgrp, &sbi->type, &sbi->min_proto,
+				&sbi->max_proto)) {
+		printk("autofs: called with bogus options\n");
+		goto fail_dput;
+	}
+
+	root_inode->i_fop = &autofs4_root_operations;
+	root_inode->i_op = autofs_type_trigger(sbi->type) ?
+			&autofs4_direct_root_inode_operations :
+			&autofs4_indirect_root_inode_operations;
+
+	/* Couldn't this be tested earlier? */
+	if (sbi->max_proto < AUTOFS_MIN_PROTO_VERSION ||
+	    sbi->min_proto > AUTOFS_MAX_PROTO_VERSION) {
+		printk("autofs: kernel does not match daemon version "
+		       "daemon (%d, %d) kernel (%d, %d)\n",
+			sbi->min_proto, sbi->max_proto,
+			AUTOFS_MIN_PROTO_VERSION, AUTOFS_MAX_PROTO_VERSION);
+		goto fail_dput;
+	}
+
+	/* Establish highest kernel protocol version */
+	if (sbi->max_proto > AUTOFS_MAX_PROTO_VERSION)
+		sbi->version = AUTOFS_MAX_PROTO_VERSION;
+	else
+		sbi->version = sbi->max_proto;
+	sbi->sub_version = AUTOFS_PROTO_SUBVERSION;
+
+	DPRINTK("pipe fd = %d, pgrp = %u", pipefd, sbi->oz_pgrp);
+	pipe = fget(pipefd);
+	
+	if (!pipe) {
+		printk("autofs: could not open pipe file descriptor\n");
+		goto fail_dput;
+	}
+	if (!pipe->f_op || !pipe->f_op->write)
+		goto fail_fput;
+	sbi->pipe = pipe;
+	sbi->pipefd = pipefd;
+	sbi->catatonic = 0;
+
+	/*
+	 * Success! Install the root dentry now to indicate completion.
+	 */
+	s->s_root = root;
+	return 0;
+	
+	/*
+	 * Failure ... clean up.
+	 */
+fail_fput:
+	printk("autofs: pipe file descriptor does not contain proper ops\n");
+	fput(pipe);
+	/* fall through */
+fail_dput:
+	dput(root);
+	goto fail_free;
+fail_iput:
+	printk("autofs: get root dentry failed\n");
+	iput(root_inode);
+fail_ino:
+	kfree(ino);
+fail_free:
+	kfree(sbi);
+	s->s_fs_info = NULL;
+fail_unlock:
+	return -EINVAL;
+}
+
+struct inode *autofs4_get_inode(struct super_block *sb,
+				struct autofs_info *inf)
+{
+	struct inode *inode = new_inode(sb);
+
+	if (inode == NULL)
+		return NULL;
+
+	inf->inode = inode;
+	inode->i_mode = inf->mode;
+	if (sb->s_root) {
+		inode->i_uid = sb->s_root->d_inode->i_uid;
+		inode->i_gid = sb->s_root->d_inode->i_gid;
+	}
+	inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+
+	if (S_ISDIR(inf->mode)) {
+		inode->i_nlink = 2;
+		inode->i_op = &autofs4_dir_inode_operations;
+		inode->i_fop = &autofs4_dir_operations;
+	} else if (S_ISLNK(inf->mode)) {
+		inode->i_size = inf->size;
+		inode->i_op = &autofs4_symlink_inode_operations;
+	}
+
+	return inode;
+}

kernel/fs/autofs4/root.c

@@ -0,0 +1,917 @@
+/* -*- c -*- --------------------------------------------------------------- *
+ *
+ * linux/fs/autofs/root.c
+ *
+ *  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 <linux/capability.h>
+#include <linux/errno.h>
+#include <linux/stat.h>
+#include <linux/param.h>
+#include <linux/time.h>
+#include "autofs_i.h"
+
+static int autofs4_dir_symlink(struct inode *,struct dentry *,const char *);
+static int autofs4_dir_unlink(struct inode *,struct dentry *);
+static int autofs4_dir_rmdir(struct inode *,struct dentry *);
+static int autofs4_dir_mkdir(struct inode *,struct dentry *,int);
+static int autofs4_root_ioctl(struct inode *, struct file *,unsigned int,unsigned long);
+static int autofs4_dir_open(struct inode *inode, struct file *file);
+static struct dentry *autofs4_lookup(struct inode *,struct dentry *, struct nameidata *);
+static void *autofs4_follow_link(struct dentry *, struct nameidata *);
+
+#define TRIGGER_FLAGS   (LOOKUP_CONTINUE | LOOKUP_DIRECTORY)
+#define TRIGGER_INTENTS (LOOKUP_OPEN | LOOKUP_CREATE)
+
+const struct file_operations autofs4_root_operations = {
+	.open		= dcache_dir_open,
+	.release	= dcache_dir_close,
+	.read		= generic_read_dir,
+	.readdir	= dcache_readdir,
+	.llseek		= dcache_dir_lseek,
+	.ioctl		= autofs4_root_ioctl,
+};
+
+const struct file_operations autofs4_dir_operations = {
+	.open		= autofs4_dir_open,
+	.release	= dcache_dir_close,
+	.read		= generic_read_dir,
+	.readdir	= dcache_readdir,
+	.llseek		= dcache_dir_lseek,
+};
+
+const struct inode_operations autofs4_indirect_root_inode_operations = {
+	.lookup		= autofs4_lookup,
+	.unlink		= autofs4_dir_unlink,
+	.symlink	= autofs4_dir_symlink,
+	.mkdir		= autofs4_dir_mkdir,
+	.rmdir		= autofs4_dir_rmdir,
+};
+
+const struct inode_operations autofs4_direct_root_inode_operations = {
+	.lookup		= autofs4_lookup,
+	.unlink		= autofs4_dir_unlink,
+	.mkdir		= autofs4_dir_mkdir,
+	.rmdir		= autofs4_dir_rmdir,
+	.follow_link	= autofs4_follow_link,
+};
+
+const struct inode_operations autofs4_dir_inode_operations = {
+	.lookup		= autofs4_lookup,
+	.unlink		= autofs4_dir_unlink,
+	.symlink	= autofs4_dir_symlink,
+	.mkdir		= autofs4_dir_mkdir,
+	.rmdir		= autofs4_dir_rmdir,
+};
+
+static int autofs4_dir_open(struct inode *inode, struct file *file)
+{
+	struct dentry *dentry = file->f_path.dentry;
+	struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
+
+	DPRINTK("file=%p dentry=%p %.*s",
+		file, dentry, dentry->d_name.len, dentry->d_name.name);
+
+	if (autofs4_oz_mode(sbi))
+		goto out;
+
+	/*
+	 * An empty directory in an autofs file system is always a
+	 * mount point. The daemon must have failed to mount this
+	 * during lookup so it doesn't exist. This can happen, for
+	 * example, if user space returns an incorrect status for a
+	 * mount request. Otherwise we're doing a readdir on the
+	 * autofs file system so just let the libfs routines handle
+	 * it.
+	 */
+	spin_lock(&dcache_lock);
+	if (!d_mountpoint(dentry) && __simple_empty(dentry)) {
+		spin_unlock(&dcache_lock);
+		return -ENOENT;
+	}
+	spin_unlock(&dcache_lock);
+
+out:
+	return dcache_dir_open(inode, file);
+}
+
+static int try_to_fill_dentry(struct dentry *dentry, int flags)
+{
+	struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
+	struct autofs_info *ino = autofs4_dentry_ino(dentry);
+	int status;
+
+	DPRINTK("dentry=%p %.*s ino=%p",
+		 dentry, dentry->d_name.len, dentry->d_name.name, dentry->d_inode);
+
+	/*
+	 * Wait for a pending mount, triggering one if there
+	 * isn't one already
+	 */
+	if (dentry->d_inode == NULL) {
+		DPRINTK("waiting for mount name=%.*s",
+			 dentry->d_name.len, dentry->d_name.name);
+
+		status = autofs4_wait(sbi, dentry, NFY_MOUNT);
+
+		DPRINTK("mount done status=%d", status);
+
+		/* Turn this into a real negative dentry? */
+		if (status == -ENOENT) {
+			spin_lock(&dentry->d_lock);
+			dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
+			spin_unlock(&dentry->d_lock);
+			return status;
+		} else if (status) {
+			/* Return a negative dentry, but leave it "pending" */
+			return status;
+		}
+	/* Trigger mount for path component or follow link */
+	} else if (dentry->d_flags & DCACHE_AUTOFS_PENDING ||
+			flags & (TRIGGER_FLAGS | TRIGGER_INTENTS) ||
+			current->link_count) {
+		DPRINTK("waiting for mount name=%.*s",
+			dentry->d_name.len, dentry->d_name.name);
+
+		spin_lock(&dentry->d_lock);
+		dentry->d_flags |= DCACHE_AUTOFS_PENDING;
+		spin_unlock(&dentry->d_lock);
+		status = autofs4_wait(sbi, dentry, NFY_MOUNT);
+
+		DPRINTK("mount done status=%d", status);
+
+		if (status) {
+			spin_lock(&dentry->d_lock);
+			dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
+			spin_unlock(&dentry->d_lock);
+			return status;
+		}
+	}
+
+	/* Initialize expiry counter after successful mount */
+	if (ino)
+		ino->last_used = jiffies;
+
+	spin_lock(&dentry->d_lock);
+	dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
+	spin_unlock(&dentry->d_lock);
+
+	return 0;
+}
+
+/* For autofs direct mounts the follow link triggers the mount */
+static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd)
+{
+	struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
+	struct autofs_info *ino = autofs4_dentry_ino(dentry);
+	int oz_mode = autofs4_oz_mode(sbi);
+	unsigned int lookup_type;
+	int status;
+
+	DPRINTK("dentry=%p %.*s oz_mode=%d nd->flags=%d",
+		dentry, dentry->d_name.len, dentry->d_name.name, oz_mode,
+		nd->flags);
+	/*
+	 * For an expire of a covered direct or offset mount we need
+	 * to break out of follow_down() at the autofs mount trigger
+	 * (d_mounted--), so we can see the expiring flag, and manage
+	 * the blocking and following here until the expire is completed.
+	 */
+	if (oz_mode) {
+		spin_lock(&sbi->fs_lock);
+		if (ino->flags & AUTOFS_INF_EXPIRING) {
+			spin_unlock(&sbi->fs_lock);
+			/* Follow down to our covering mount. */
+			if (!follow_down(&nd->path))
+				goto done;
+			goto follow;
+		}
+		spin_unlock(&sbi->fs_lock);
+		goto done;
+	}
+
+	/* If an expire request is pending everyone must wait. */
+	autofs4_expire_wait(dentry);
+
+	/* We trigger a mount for almost all flags */
+	lookup_type = nd->flags & (TRIGGER_FLAGS | TRIGGER_INTENTS);
+	if (!(lookup_type || dentry->d_flags & DCACHE_AUTOFS_PENDING))
+		goto follow;
+
+	/*
+	 * If the dentry contains directories then it is an autofs
+	 * multi-mount with no root mount offset. So don't try to
+	 * mount it again.
+	 */
+	spin_lock(&dcache_lock);
+	if (dentry->d_flags & DCACHE_AUTOFS_PENDING ||
+	    (!d_mountpoint(dentry) && __simple_empty(dentry))) {
+		spin_unlock(&dcache_lock);
+
+		status = try_to_fill_dentry(dentry, 0);
+		if (status)
+			goto out_error;
+
+		goto follow;
+	}
+	spin_unlock(&dcache_lock);
+follow:
+	/*
+	 * If there is no root mount it must be an autofs
+	 * multi-mount with no root offset so we don't need
+	 * to follow it.
+	 */
+	if (d_mountpoint(dentry)) {
+		if (!autofs4_follow_mount(&nd->path)) {
+			status = -ENOENT;
+			goto out_error;
+		}
+	}
+
+done:
+	return NULL;
+
+out_error:
+	path_put(&nd->path);
+	return ERR_PTR(status);
+}
+
+/*
+ * Revalidate is called on every cache lookup.  Some of those
+ * cache lookups may actually happen while the dentry is not
+ * yet completely filled in, and revalidate has to delay such
+ * lookups..
+ */
+static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd)
+{
+	struct inode *dir = dentry->d_parent->d_inode;
+	struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
+	int oz_mode = autofs4_oz_mode(sbi);
+	int flags = nd ? nd->flags : 0;
+	int status = 1;
+
+	/* Pending dentry */
+	spin_lock(&sbi->fs_lock);
+	if (autofs4_ispending(dentry)) {
+		/* The daemon never causes a mount to trigger */
+		spin_unlock(&sbi->fs_lock);
+
+		if (oz_mode)
+			return 1;
+
+		/*
+		 * If the directory has gone away due to an expire
+		 * we have been called as ->d_revalidate() and so
+		 * we need to return false and proceed to ->lookup().
+		 */
+		if (autofs4_expire_wait(dentry) == -EAGAIN)
+			return 0;
+
+		/*
+		 * A zero status is success otherwise we have a
+		 * negative error code.
+		 */
+		status = try_to_fill_dentry(dentry, flags);
+		if (status == 0)
+			return 1;
+
+		return status;
+	}
+	spin_unlock(&sbi->fs_lock);
+
+	/* Negative dentry.. invalidate if "old" */
+	if (dentry->d_inode == NULL)
+		return 0;
+
+	/* Check for a non-mountpoint directory with no contents */
+	spin_lock(&dcache_lock);
+	if (S_ISDIR(dentry->d_inode->i_mode) &&
+	    !d_mountpoint(dentry) && 
+	    __simple_empty(dentry)) {
+		DPRINTK("dentry=%p %.*s, emptydir",
+			 dentry, dentry->d_name.len, dentry->d_name.name);
+		spin_unlock(&dcache_lock);
+
+		/* The daemon never causes a mount to trigger */
+		if (oz_mode)
+			return 1;
+
+		/*
+		 * A zero status is success otherwise we have a
+		 * negative error code.
+		 */
+		status = try_to_fill_dentry(dentry, flags);
+		if (status == 0)
+			return 1;
+
+		return status;
+	}
+	spin_unlock(&dcache_lock);
+
+	return 1;
+}
+
+void autofs4_dentry_release(struct dentry *de)
+{
+	struct autofs_info *inf;
+
+	DPRINTK("releasing %p", de);
+
+	inf = autofs4_dentry_ino(de);
+	de->d_fsdata = NULL;
+
+	if (inf) {
+		struct autofs_sb_info *sbi = autofs4_sbi(de->d_sb);
+
+		if (sbi) {
+			spin_lock(&sbi->lookup_lock);
+			if (!list_empty(&inf->active))
+				list_del(&inf->active);
+			if (!list_empty(&inf->expiring))
+				list_del(&inf->expiring);
+			spin_unlock(&sbi->lookup_lock);
+		}
+
+		inf->dentry = NULL;
+		inf->inode = NULL;
+
+		autofs4_free_ino(inf);
+	}
+}
+
+/* For dentries of directories in the root dir */
+static const struct dentry_operations autofs4_root_dentry_operations = {
+	.d_revalidate	= autofs4_revalidate,
+	.d_release	= autofs4_dentry_release,
+};
+
+/* For other dentries */
+static const struct dentry_operations autofs4_dentry_operations = {
+	.d_revalidate	= autofs4_revalidate,
+	.d_release	= autofs4_dentry_release,
+};
+
+static struct dentry *autofs4_lookup_active(struct autofs_sb_info *sbi, struct dentry *parent, struct qstr *name)
+{
+	unsigned int len = name->len;
+	unsigned int hash = name->hash;
+	const unsigned char *str = name->name;
+	struct list_head *p, *head;
+
+	spin_lock(&dcache_lock);
+	spin_lock(&sbi->lookup_lock);
+	head = &sbi->active_list;
+	list_for_each(p, head) {
+		struct autofs_info *ino;
+		struct dentry *dentry;
+		struct qstr *qstr;
+
+		ino = list_entry(p, struct autofs_info, active);
+		dentry = ino->dentry;
+
+		spin_lock(&dentry->d_lock);
+
+		/* Already gone? */
+		if (atomic_read(&dentry->d_count) == 0)
+			goto next;
+
+		qstr = &dentry->d_name;
+
+		if (dentry->d_name.hash != hash)
+			goto next;
+		if (dentry->d_parent != parent)
+			goto next;
+
+		if (qstr->len != len)
+			goto next;
+		if (memcmp(qstr->name, str, len))
+			goto next;
+
+		if (d_unhashed(dentry)) {
+			dget(dentry);
+			spin_unlock(&dentry->d_lock);
+			spin_unlock(&sbi->lookup_lock);
+			spin_unlock(&dcache_lock);
+			return dentry;
+		}
+next:
+		spin_unlock(&dentry->d_lock);
+	}
+	spin_unlock(&sbi->lookup_lock);
+	spin_unlock(&dcache_lock);
+
+	return NULL;
+}
+
+static struct dentry *autofs4_lookup_expiring(struct autofs_sb_info *sbi, struct dentry *parent, struct qstr *name)
+{
+	unsigned int len = name->len;
+	unsigned int hash = name->hash;
+	const unsigned char *str = name->name;
+	struct list_head *p, *head;
+
+	spin_lock(&dcache_lock);
+	spin_lock(&sbi->lookup_lock);
+	head = &sbi->expiring_list;
+	list_for_each(p, head) {
+		struct autofs_info *ino;
+		struct dentry *dentry;
+		struct qstr *qstr;
+
+		ino = list_entry(p, struct autofs_info, expiring);
+		dentry = ino->dentry;
+
+		spin_lock(&dentry->d_lock);
+
+		/* Bad luck, we've already been dentry_iput */
+		if (!dentry->d_inode)
+			goto next;
+
+		qstr = &dentry->d_name;
+
+		if (dentry->d_name.hash != hash)
+			goto next;
+		if (dentry->d_parent != parent)
+			goto next;
+
+		if (qstr->len != len)
+			goto next;
+		if (memcmp(qstr->name, str, len))
+			goto next;
+
+		if (d_unhashed(dentry)) {
+			dget(dentry);
+			spin_unlock(&dentry->d_lock);
+			spin_unlock(&sbi->lookup_lock);
+			spin_unlock(&dcache_lock);
+			return dentry;
+		}
+next:
+		spin_unlock(&dentry->d_lock);
+	}
+	spin_unlock(&sbi->lookup_lock);
+	spin_unlock(&dcache_lock);
+
+	return NULL;
+}
+
+/* Lookups in the root directory */
+static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
+{
+	struct autofs_sb_info *sbi;
+	struct autofs_info *ino;
+	struct dentry *expiring, *unhashed;
+	int oz_mode;
+
+	DPRINTK("name = %.*s",
+		dentry->d_name.len, dentry->d_name.name);
+
+	/* File name too long to exist */
+	if (dentry->d_name.len > NAME_MAX)
+		return ERR_PTR(-ENAMETOOLONG);
+
+	sbi = autofs4_sbi(dir->i_sb);
+	oz_mode = autofs4_oz_mode(sbi);
+
+	DPRINTK("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d",
+		 current->pid, task_pgrp_nr(current), sbi->catatonic, oz_mode);
+
+	unhashed = autofs4_lookup_active(sbi, dentry->d_parent, &dentry->d_name);
+	if (unhashed)
+		dentry = unhashed;
+	else {
+		/*
+		 * Mark the dentry incomplete but don't hash it. We do this
+		 * to serialize our inode creation operations (symlink and
+		 * mkdir) which prevents deadlock during the callback to
+		 * the daemon. Subsequent user space lookups for the same
+		 * dentry are placed on the wait queue while the daemon
+		 * itself is allowed passage unresticted so the create
+		 * operation itself can then hash the dentry. Finally,
+		 * we check for the hashed dentry and return the newly
+		 * hashed dentry.
+		 */
+		dentry->d_op = &autofs4_root_dentry_operations;
+
+		/*
+		 * And we need to ensure that the same dentry is used for
+		 * all following lookup calls until it is hashed so that
+		 * the dentry flags are persistent throughout the request.
+		 */
+		ino = autofs4_init_ino(NULL, sbi, 0555);
+		if (!ino)
+			return ERR_PTR(-ENOMEM);
+
+		dentry->d_fsdata = ino;
+		ino->dentry = dentry;
+
+		spin_lock(&sbi->lookup_lock);
+		list_add(&ino->active, &sbi->active_list);
+		spin_unlock(&sbi->lookup_lock);
+
+		d_instantiate(dentry, NULL);
+	}
+
+	if (!oz_mode) {
+		mutex_unlock(&dir->i_mutex);
+		expiring = autofs4_lookup_expiring(sbi,
+						   dentry->d_parent,
+						   &dentry->d_name);
+		if (expiring) {
+			/*
+			 * If we are racing with expire the request might not
+			 * be quite complete but the directory has been removed
+			 * so it must have been successful, so just wait for it.
+			 */
+			ino = autofs4_dentry_ino(expiring);
+			autofs4_expire_wait(expiring);
+			spin_lock(&sbi->lookup_lock);
+			if (!list_empty(&ino->expiring))
+				list_del_init(&ino->expiring);
+			spin_unlock(&sbi->lookup_lock);
+			dput(expiring);
+		}
+
+		spin_lock(&dentry->d_lock);
+		dentry->d_flags |= DCACHE_AUTOFS_PENDING;
+		spin_unlock(&dentry->d_lock);
+		if (dentry->d_op && dentry->d_op->d_revalidate)
+			(dentry->d_op->d_revalidate)(dentry, nd);
+		mutex_lock(&dir->i_mutex);
+	}
+
+	/*
+	 * If we are still pending, check if we had to handle
+	 * a signal. If so we can force a restart..
+	 */
+	if (dentry->d_flags & DCACHE_AUTOFS_PENDING) {
+		/* See if we were interrupted */
+		if (signal_pending(current)) {
+			sigset_t *sigset = &current->pending.signal;
+			if (sigismember (sigset, SIGKILL) ||
+			    sigismember (sigset, SIGQUIT) ||
+			    sigismember (sigset, SIGINT)) {
+			    if (unhashed)
+				dput(unhashed);
+			    return ERR_PTR(-ERESTARTNOINTR);
+			}
+		}
+		if (!oz_mode) {
+			spin_lock(&dentry->d_lock);
+			dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
+			spin_unlock(&dentry->d_lock);
+		}
+	}
+
+	/*
+	 * If this dentry is unhashed, then we shouldn't honour this
+	 * lookup.  Returning ENOENT here doesn't do the right thing
+	 * for all system calls, but it should be OK for the operations
+	 * we permit from an autofs.
+	 */
+	if (!oz_mode && d_unhashed(dentry)) {
+		/*
+		 * A user space application can (and has done in the past)
+		 * remove and re-create this directory during the callback.
+		 * This can leave us with an unhashed dentry, but a
+		 * successful mount!  So we need to perform another
+		 * cached lookup in case the dentry now exists.
+		 */
+		struct dentry *parent = dentry->d_parent;
+		struct dentry *new = d_lookup(parent, &dentry->d_name);
+		if (new != NULL)
+			dentry = new;
+		else
+			dentry = ERR_PTR(-ENOENT);
+
+		if (unhashed)
+			dput(unhashed);
+
+		return dentry;
+	}
+
+	if (unhashed)
+		return unhashed;
+
+	return NULL;
+}
+
+static int autofs4_dir_symlink(struct inode *dir, 
+			       struct dentry *dentry,
+			       const char *symname)
+{
+	struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
+	struct autofs_info *ino = autofs4_dentry_ino(dentry);
+	struct autofs_info *p_ino;
+	struct inode *inode;
+	char *cp;
+
+	DPRINTK("%s <- %.*s", symname,
+		dentry->d_name.len, dentry->d_name.name);
+
+	if (!autofs4_oz_mode(sbi))
+		return -EACCES;
+
+	ino = autofs4_init_ino(ino, sbi, S_IFLNK | 0555);
+	if (!ino)
+		return -ENOMEM;
+
+	spin_lock(&sbi->lookup_lock);
+	if (!list_empty(&ino->active))
+		list_del_init(&ino->active);
+	spin_unlock(&sbi->lookup_lock);
+
+	ino->size = strlen(symname);
+	cp = kmalloc(ino->size + 1, GFP_KERNEL);
+	if (!cp) {
+		if (!dentry->d_fsdata)
+			kfree(ino);
+		return -ENOMEM;
+	}
+
+	strcpy(cp, symname);
+
+	inode = autofs4_get_inode(dir->i_sb, ino);
+	if (!inode) {
+		kfree(cp);
+		if (!dentry->d_fsdata)
+			kfree(ino);
+		return -ENOMEM;
+	}
+	d_add(dentry, inode);
+
+	if (dir == dir->i_sb->s_root->d_inode)
+		dentry->d_op = &autofs4_root_dentry_operations;
+	else
+		dentry->d_op = &autofs4_dentry_operations;
+
+	dentry->d_fsdata = ino;
+	ino->dentry = dget(dentry);
+	atomic_inc(&ino->count);
+	p_ino = autofs4_dentry_ino(dentry->d_parent);
+	if (p_ino && dentry->d_parent != dentry)
+		atomic_inc(&p_ino->count);
+	ino->inode = inode;
+
+	ino->u.symlink = cp;
+	dir->i_mtime = CURRENT_TIME;
+
+	return 0;
+}
+
+/*
+ * NOTE!
+ *
+ * Normal filesystems would do a "d_delete()" to tell the VFS dcache
+ * that the file no longer exists. However, doing that means that the
+ * VFS layer can turn the dentry into a negative dentry.  We don't want
+ * this, because the unlink is probably the result of an expire.
+ * We simply d_drop it and add it to a expiring list in the super block,
+ * which allows the dentry lookup to check for an incomplete expire.
+ *
+ * If a process is blocked on the dentry waiting for the expire to finish,
+ * it will invalidate the dentry and try to mount with a new one.
+ *
+ * Also see autofs4_dir_rmdir()..
+ */
+static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry)
+{
+	struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
+	struct autofs_info *ino = autofs4_dentry_ino(dentry);
+	struct autofs_info *p_ino;
+	
+	/* This allows root to remove symlinks */
+	if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN))
+		return -EACCES;
+
+	if (atomic_dec_and_test(&ino->count)) {
+		p_ino = autofs4_dentry_ino(dentry->d_parent);
+		if (p_ino && dentry->d_parent != dentry)
+			atomic_dec(&p_ino->count);
+	}
+	dput(ino->dentry);
+
+	dentry->d_inode->i_size = 0;
+	clear_nlink(dentry->d_inode);
+
+	dir->i_mtime = CURRENT_TIME;
+
+	spin_lock(&dcache_lock);
+	spin_lock(&sbi->lookup_lock);
+	if (list_empty(&ino->expiring))
+		list_add(&ino->expiring, &sbi->expiring_list);
+	spin_unlock(&sbi->lookup_lock);
+	spin_lock(&dentry->d_lock);
+	__d_drop(dentry);
+	spin_unlock(&dentry->d_lock);
+	spin_unlock(&dcache_lock);
+
+	return 0;
+}
+
+static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry)
+{
+	struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
+	struct autofs_info *ino = autofs4_dentry_ino(dentry);
+	struct autofs_info *p_ino;
+	
+	DPRINTK("dentry %p, removing %.*s",
+		dentry, dentry->d_name.len, dentry->d_name.name);
+
+	if (!autofs4_oz_mode(sbi))
+		return -EACCES;
+
+	spin_lock(&dcache_lock);
+	if (!list_empty(&dentry->d_subdirs)) {
+		spin_unlock(&dcache_lock);
+		return -ENOTEMPTY;
+	}
+	spin_lock(&sbi->lookup_lock);
+	if (list_empty(&ino->expiring))
+		list_add(&ino->expiring, &sbi->expiring_list);
+	spin_unlock(&sbi->lookup_lock);
+	spin_lock(&dentry->d_lock);
+	__d_drop(dentry);
+	spin_unlock(&dentry->d_lock);
+	spin_unlock(&dcache_lock);
+
+	if (atomic_dec_and_test(&ino->count)) {
+		p_ino = autofs4_dentry_ino(dentry->d_parent);
+		if (p_ino && dentry->d_parent != dentry)
+			atomic_dec(&p_ino->count);
+	}
+	dput(ino->dentry);
+	dentry->d_inode->i_size = 0;
+	clear_nlink(dentry->d_inode);
+
+	if (dir->i_nlink)
+		drop_nlink(dir);
+
+	return 0;
+}
+
+static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, int mode)
+{
+	struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
+	struct autofs_info *ino = autofs4_dentry_ino(dentry);
+	struct autofs_info *p_ino;
+	struct inode *inode;
+
+	if (!autofs4_oz_mode(sbi))
+		return -EACCES;
+
+	DPRINTK("dentry %p, creating %.*s",
+		dentry, dentry->d_name.len, dentry->d_name.name);
+
+	ino = autofs4_init_ino(ino, sbi, S_IFDIR | 0555);
+	if (!ino)
+		return -ENOMEM;
+
+	spin_lock(&sbi->lookup_lock);
+	if (!list_empty(&ino->active))
+		list_del_init(&ino->active);
+	spin_unlock(&sbi->lookup_lock);
+
+	inode = autofs4_get_inode(dir->i_sb, ino);
+	if (!inode) {
+		if (!dentry->d_fsdata)
+			kfree(ino);
+		return -ENOMEM;
+	}
+	d_add(dentry, inode);
+
+	if (dir == dir->i_sb->s_root->d_inode)
+		dentry->d_op = &autofs4_root_dentry_operations;
+	else
+		dentry->d_op = &autofs4_dentry_operations;
+
+	dentry->d_fsdata = ino;
+	ino->dentry = dget(dentry);
+	atomic_inc(&ino->count);
+	p_ino = autofs4_dentry_ino(dentry->d_parent);
+	if (p_ino && dentry->d_parent != dentry)
+		atomic_inc(&p_ino->count);
+	ino->inode = inode;
+	inc_nlink(dir);
+	dir->i_mtime = CURRENT_TIME;
+
+	return 0;
+}
+
+/* Get/set timeout ioctl() operation */
+static inline int autofs4_get_set_timeout(struct autofs_sb_info *sbi,
+					 unsigned long __user *p)
+{
+	int rv;
+	unsigned long ntimeout;
+
+	if ((rv = get_user(ntimeout, p)) ||
+	     (rv = put_user(sbi->exp_timeout/HZ, p)))
+		return rv;
+
+	if (ntimeout > ULONG_MAX/HZ)
+		sbi->exp_timeout = 0;
+	else
+		sbi->exp_timeout = ntimeout * HZ;
+
+	return 0;
+}
+
+/* Return protocol version */
+static inline int autofs4_get_protover(struct autofs_sb_info *sbi, int __user *p)
+{
+	return put_user(sbi->version, p);
+}
+
+/* Return protocol sub version */
+static inline int autofs4_get_protosubver(struct autofs_sb_info *sbi, int __user *p)
+{
+	return put_user(sbi->sub_version, p);
+}
+
+/*
+* Tells the daemon whether it can umount the autofs mount.
+*/
+static inline int autofs4_ask_umount(struct vfsmount *mnt, int __user *p)
+{
+	int status = 0;
+
+	if (may_umount(mnt))
+		status = 1;
+
+	DPRINTK("returning %d", status);
+
+	status = put_user(status, p);
+
+	return status;
+}
+
+/* Identify autofs4_dentries - this is so we can tell if there's
+   an extra dentry refcount or not.  We only hold a refcount on the
+   dentry if its non-negative (ie, d_inode != NULL)
+*/
+int is_autofs4_dentry(struct dentry *dentry)
+{
+	return dentry && dentry->d_inode &&
+		(dentry->d_op == &autofs4_root_dentry_operations ||
+		 dentry->d_op == &autofs4_dentry_operations) &&
+		dentry->d_fsdata != NULL;
+}
+
+/*
+ * ioctl()'s on the root directory is the chief method for the daemon to
+ * generate kernel reactions
+ */
+static int autofs4_root_ioctl(struct inode *inode, struct file *filp,
+			     unsigned int cmd, unsigned long arg)
+{
+	struct autofs_sb_info *sbi = autofs4_sbi(inode->i_sb);
+	void __user *p = (void __user *)arg;
+
+	DPRINTK("cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u",
+		cmd,arg,sbi,task_pgrp_nr(current));
+
+	if (_IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) ||
+	     _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT)
+		return -ENOTTY;
+	
+	if (!autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN))
+		return -EPERM;
+	
+	switch(cmd) {
+	case AUTOFS_IOC_READY:	/* Wait queue: go ahead and retry */
+		return autofs4_wait_release(sbi,(autofs_wqt_t)arg,0);
+	case AUTOFS_IOC_FAIL:	/* Wait queue: fail with ENOENT */
+		return autofs4_wait_release(sbi,(autofs_wqt_t)arg,-ENOENT);
+	case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */
+		autofs4_catatonic_mode(sbi);
+		return 0;
+	case AUTOFS_IOC_PROTOVER: /* Get protocol version */
+		return autofs4_get_protover(sbi, p);
+	case AUTOFS_IOC_PROTOSUBVER: /* Get protocol sub version */
+		return autofs4_get_protosubver(sbi, p);
+	case AUTOFS_IOC_SETTIMEOUT:
+		return autofs4_get_set_timeout(sbi, p);
+
+	case AUTOFS_IOC_ASKUMOUNT:
+		return autofs4_ask_umount(filp->f_path.mnt, p);
+
+	/* return a single thing to expire */
+	case AUTOFS_IOC_EXPIRE:
+		return autofs4_expire_run(inode->i_sb,filp->f_path.mnt,sbi, p);
+	/* same as above, but can send multiple expires through pipe */
+	case AUTOFS_IOC_EXPIRE_MULTI:
+		return autofs4_expire_multi(inode->i_sb,filp->f_path.mnt,sbi, p);
+
+	default:
+		return -ENOSYS;
+	}
+}

kernel/fs/autofs4/symlink.c

@@ -0,0 +1,25 @@
+/* -*- c -*- --------------------------------------------------------------- *
+ *
+ * linux/fs/autofs/symlink.c
+ *
+ *  Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
+ *
+ * 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 void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd)
+{
+	struct autofs_info *ino = autofs4_dentry_ino(dentry);
+	nd_set_link(nd, (char *)ino->u.symlink);
+	return NULL;
+}
+
+const struct inode_operations autofs4_symlink_inode_operations = {
+	.readlink	= generic_readlink,
+	.follow_link	= autofs4_follow_link
+};

kernel/fs/autofs4/waitq.c

@@ -0,0 +1,524 @@
+/* -*- c -*- --------------------------------------------------------------- *
+ *
+ * linux/fs/autofs/waitq.c
+ *
+ *  Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
+ *  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 <linux/slab.h>
+#include <linux/time.h>
+#include <linux/signal.h>
+#include <linux/file.h>
+#include "autofs_i.h"
+
+/* We make this a static variable rather than a part of the superblock; it
+   is better if we don't reassign numbers easily even across filesystems */
+static autofs_wqt_t autofs4_next_wait_queue = 1;
+
+/* These are the signals we allow interrupting a pending mount */
+#define SHUTDOWN_SIGS	(sigmask(SIGKILL) | sigmask(SIGINT) | sigmask(SIGQUIT))
+
+void autofs4_catatonic_mode(struct autofs_sb_info *sbi)
+{
+	struct autofs_wait_queue *wq, *nwq;
+
+	mutex_lock(&sbi->wq_mutex);
+	if (sbi->catatonic) {
+		mutex_unlock(&sbi->wq_mutex);
+		return;
+	}
+
+	DPRINTK("entering catatonic mode");
+
+	sbi->catatonic = 1;
+	wq = sbi->queues;
+	sbi->queues = NULL;	/* Erase all wait queues */
+	while (wq) {
+		nwq = wq->next;
+		wq->status = -ENOENT; /* Magic is gone - report failure */
+		if (wq->name.name) {
+			kfree(wq->name.name);
+			wq->name.name = NULL;
+		}
+		wq->wait_ctr--;
+		wake_up_interruptible(&wq->queue);
+		wq = nwq;
+	}
+	fput(sbi->pipe);	/* Close the pipe */
+	sbi->pipe = NULL;
+	sbi->pipefd = -1;
+	mutex_unlock(&sbi->wq_mutex);
+}
+
+static int autofs4_write(struct file *file, const void *addr, int bytes)
+{
+	unsigned long sigpipe, flags;
+	mm_segment_t fs;
+	const char *data = (const char *)addr;
+	ssize_t wr = 0;
+
+	/** WARNING: this is not safe for writing more than PIPE_BUF bytes! **/
+
+	sigpipe = sigismember(&current->pending.signal, SIGPIPE);
+
+	/* Save pointer to user space and point back to kernel space */
+	fs = get_fs();
+	set_fs(KERNEL_DS);
+
+	while (bytes &&
+	       (wr = file->f_op->write(file,data,bytes,&file->f_pos)) > 0) {
+		data += wr;
+		bytes -= wr;
+	}
+
+	set_fs(fs);
+
+	/* Keep the currently executing process from receiving a
+	   SIGPIPE unless it was already supposed to get one */
+	if (wr == -EPIPE && !sigpipe) {
+		spin_lock_irqsave(&current->sighand->siglock, flags);
+		sigdelset(&current->pending.signal, SIGPIPE);
+		recalc_sigpending();
+		spin_unlock_irqrestore(&current->sighand->siglock, flags);
+	}
+
+	return (bytes > 0);
+}
+	
+static void autofs4_notify_daemon(struct autofs_sb_info *sbi,
+				 struct autofs_wait_queue *wq,
+				 int type)
+{
+	union {
+		struct autofs_packet_hdr hdr;
+		union autofs_packet_union v4_pkt;
+		union autofs_v5_packet_union v5_pkt;
+	} pkt;
+	struct file *pipe = NULL;
+	size_t pktsz;
+
+	DPRINTK("wait id = 0x%08lx, name = %.*s, type=%d",
+		wq->wait_queue_token, wq->name.len, wq->name.name, type);
+
+	memset(&pkt,0,sizeof pkt); /* For security reasons */
+
+	pkt.hdr.proto_version = sbi->version;
+	pkt.hdr.type = type;
+	switch (type) {
+	/* Kernel protocol v4 missing and expire packets */
+	case autofs_ptype_missing:
+	{
+		struct autofs_packet_missing *mp = &pkt.v4_pkt.missing;
+
+		pktsz = sizeof(*mp);
+
+		mp->wait_queue_token = wq->wait_queue_token;
+		mp->len = wq->name.len;
+		memcpy(mp->name, wq->name.name, wq->name.len);
+		mp->name[wq->name.len] = '\0';
+		break;
+	}
+	case autofs_ptype_expire_multi:
+	{
+		struct autofs_packet_expire_multi *ep = &pkt.v4_pkt.expire_multi;
+
+		pktsz = sizeof(*ep);
+
+		ep->wait_queue_token = wq->wait_queue_token;
+		ep->len = wq->name.len;
+		memcpy(ep->name, wq->name.name, wq->name.len);
+		ep->name[wq->name.len] = '\0';
+		break;
+	}
+	/*
+	 * Kernel protocol v5 packet for handling indirect and direct
+	 * mount missing and expire requests
+	 */
+	case autofs_ptype_missing_indirect:
+	case autofs_ptype_expire_indirect:
+	case autofs_ptype_missing_direct:
+	case autofs_ptype_expire_direct:
+	{
+		struct autofs_v5_packet *packet = &pkt.v5_pkt.v5_packet;
+
+		pktsz = sizeof(*packet);
+
+		packet->wait_queue_token = wq->wait_queue_token;
+		packet->len = wq->name.len;
+		memcpy(packet->name, wq->name.name, wq->name.len);
+		packet->name[wq->name.len] = '\0';
+		packet->dev = wq->dev;
+		packet->ino = wq->ino;
+		packet->uid = wq->uid;
+		packet->gid = wq->gid;
+		packet->pid = wq->pid;
+		packet->tgid = wq->tgid;
+		break;
+	}
+	default:
+		printk("autofs4_notify_daemon: bad type %d!\n", type);
+		return;
+	}
+
+	/* Check if we have become catatonic */
+	mutex_lock(&sbi->wq_mutex);
+	if (!sbi->catatonic) {
+		pipe = sbi->pipe;
+		get_file(pipe);
+	}
+	mutex_unlock(&sbi->wq_mutex);
+
+	if (pipe) {
+		if (autofs4_write(pipe, &pkt, pktsz))
+			autofs4_catatonic_mode(sbi);
+		fput(pipe);
+	}
+}
+
+static int autofs4_getpath(struct autofs_sb_info *sbi,
+			   struct dentry *dentry, char **name)
+{
+	struct dentry *root = sbi->sb->s_root;
+	struct dentry *tmp;
+	char *buf = *name;
+	char *p;
+	int len = 0;
+
+	spin_lock(&dcache_lock);
+	for (tmp = dentry ; tmp != root ; tmp = tmp->d_parent)
+		len += tmp->d_name.len + 1;
+
+	if (!len || --len > NAME_MAX) {
+		spin_unlock(&dcache_lock);
+		return 0;
+	}
+
+	*(buf + len) = '\0';
+	p = buf + len - dentry->d_name.len;
+	strncpy(p, dentry->d_name.name, dentry->d_name.len);
+
+	for (tmp = dentry->d_parent; tmp != root ; tmp = tmp->d_parent) {
+		*(--p) = '/';
+		p -= tmp->d_name.len;
+		strncpy(p, tmp->d_name.name, tmp->d_name.len);
+	}
+	spin_unlock(&dcache_lock);
+
+	return len;
+}
+
+static struct autofs_wait_queue *
+autofs4_find_wait(struct autofs_sb_info *sbi, struct qstr *qstr)
+{
+	struct autofs_wait_queue *wq;
+
+	for (wq = sbi->queues; wq; wq = wq->next) {
+		if (wq->name.hash == qstr->hash &&
+		    wq->name.len == qstr->len &&
+		    wq->name.name &&
+			 !memcmp(wq->name.name, qstr->name, qstr->len))
+			break;
+	}
+	return wq;
+}
+
+/*
+ * Check if we have a valid request.
+ * Returns
+ * 1 if the request should continue.
+ *   In this case we can return an autofs_wait_queue entry if one is
+ *   found or NULL to idicate a new wait needs to be created.
+ * 0 or a negative errno if the request shouldn't continue.
+ */
+static int validate_request(struct autofs_wait_queue **wait,
+			    struct autofs_sb_info *sbi,
+			    struct qstr *qstr,
+			    struct dentry*dentry, enum autofs_notify notify)
+{
+	struct autofs_wait_queue *wq;
+	struct autofs_info *ino;
+
+	/* Wait in progress, continue; */
+	wq = autofs4_find_wait(sbi, qstr);
+	if (wq) {
+		*wait = wq;
+		return 1;
+	}
+
+	*wait = NULL;
+
+	/* If we don't yet have any info this is a new request */
+	ino = autofs4_dentry_ino(dentry);
+	if (!ino)
+		return 1;
+
+	/*
+	 * If we've been asked to wait on an existing expire (NFY_NONE)
+	 * but there is no wait in the queue ...
+	 */
+	if (notify == NFY_NONE) {
+		/*
+		 * Either we've betean the pending expire to post it's
+		 * wait or it finished while we waited on the mutex.
+		 * So we need to wait till either, the wait appears
+		 * or the expire finishes.
+		 */
+
+		while (ino->flags & AUTOFS_INF_EXPIRING) {
+			mutex_unlock(&sbi->wq_mutex);
+			schedule_timeout_interruptible(HZ/10);
+			if (mutex_lock_interruptible(&sbi->wq_mutex))
+				return -EINTR;
+
+			wq = autofs4_find_wait(sbi, qstr);
+			if (wq) {
+				*wait = wq;
+				return 1;
+			}
+		}
+
+		/*
+		 * Not ideal but the status has already gone. Of the two
+		 * cases where we wait on NFY_NONE neither depend on the
+		 * return status of the wait.
+		 */
+		return 0;
+	}
+
+	/*
+	 * If we've been asked to trigger a mount and the request
+	 * completed while we waited on the mutex ...
+	 */
+	if (notify == NFY_MOUNT) {
+		/*
+		 * If the dentry was successfully mounted while we slept
+		 * on the wait queue mutex we can return success. If it
+		 * isn't mounted (doesn't have submounts for the case of
+		 * a multi-mount with no mount at it's base) we can
+		 * continue on and create a new request.
+		 */
+		if (have_submounts(dentry))
+			return 0;
+	}
+
+	return 1;
+}
+
+int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry,
+		enum autofs_notify notify)
+{
+	struct autofs_wait_queue *wq;
+	struct qstr qstr;
+	char *name;
+	int status, ret, type;
+
+	/* In catatonic mode, we don't wait for nobody */
+	if (sbi->catatonic)
+		return -ENOENT;
+
+	if (!dentry->d_inode) {
+		/*
+		 * A wait for a negative dentry is invalid for certain
+		 * cases. A direct or offset mount "always" has its mount
+		 * point directory created and so the request dentry must
+		 * be positive or the map key doesn't exist. The situation
+		 * is very similar for indirect mounts except only dentrys
+		 * in the root of the autofs file system may be negative.
+		 */
+		if (autofs_type_trigger(sbi->type))
+			return -ENOENT;
+		else if (!IS_ROOT(dentry->d_parent))
+			return -ENOENT;
+	}
+
+	name = kmalloc(NAME_MAX + 1, GFP_KERNEL);
+	if (!name)
+		return -ENOMEM;
+
+	/* If this is a direct mount request create a dummy name */
+	if (IS_ROOT(dentry) && autofs_type_trigger(sbi->type))
+		qstr.len = sprintf(name, "%p", dentry);
+	else {
+		qstr.len = autofs4_getpath(sbi, dentry, &name);
+		if (!qstr.len) {
+			kfree(name);
+			return -ENOENT;
+		}
+	}
+	qstr.name = name;
+	qstr.hash = full_name_hash(name, qstr.len);
+
+	if (mutex_lock_interruptible(&sbi->wq_mutex)) {
+		kfree(qstr.name);
+		return -EINTR;
+	}
+
+	ret = validate_request(&wq, sbi, &qstr, dentry, notify);
+	if (ret <= 0) {
+		if (ret == 0)
+			mutex_unlock(&sbi->wq_mutex);
+		kfree(qstr.name);
+		return ret;
+	}
+
+	if (!wq) {
+		/* Create a new wait queue */
+		wq = kmalloc(sizeof(struct autofs_wait_queue),GFP_KERNEL);
+		if (!wq) {
+			kfree(qstr.name);
+			mutex_unlock(&sbi->wq_mutex);
+			return -ENOMEM;
+		}
+
+		wq->wait_queue_token = autofs4_next_wait_queue;
+		if (++autofs4_next_wait_queue == 0)
+			autofs4_next_wait_queue = 1;
+		wq->next = sbi->queues;
+		sbi->queues = wq;
+		init_waitqueue_head(&wq->queue);
+		memcpy(&wq->name, &qstr, sizeof(struct qstr));
+		wq->dev = autofs4_get_dev(sbi);
+		wq->ino = autofs4_get_ino(sbi);
+		wq->uid = current_uid();
+		wq->gid = current_gid();
+		wq->pid = current->pid;
+		wq->tgid = current->tgid;
+		wq->status = -EINTR; /* Status return if interrupted */
+		wq->wait_ctr = 2;
+		mutex_unlock(&sbi->wq_mutex);
+
+		if (sbi->version < 5) {
+			if (notify == NFY_MOUNT)
+				type = autofs_ptype_missing;
+			else
+				type = autofs_ptype_expire_multi;
+		} else {
+			if (notify == NFY_MOUNT)
+				type = autofs_type_trigger(sbi->type) ?
+					autofs_ptype_missing_direct :
+					 autofs_ptype_missing_indirect;
+			else
+				type = autofs_type_trigger(sbi->type) ?
+					autofs_ptype_expire_direct :
+					autofs_ptype_expire_indirect;
+		}
+
+		DPRINTK("new wait id = 0x%08lx, name = %.*s, nfy=%d\n",
+			(unsigned long) wq->wait_queue_token, wq->name.len,
+			wq->name.name, notify);
+
+		/* autofs4_notify_daemon() may block */
+		autofs4_notify_daemon(sbi, wq, type);
+	} else {
+		wq->wait_ctr++;
+		mutex_unlock(&sbi->wq_mutex);
+		kfree(qstr.name);
+		DPRINTK("existing wait id = 0x%08lx, name = %.*s, nfy=%d",
+			(unsigned long) wq->wait_queue_token, wq->name.len,
+			wq->name.name, notify);
+	}
+
+	/*
+	 * wq->name.name is NULL iff the lock is already released
+	 * or the mount has been made catatonic.
+	 */
+	if (wq->name.name) {
+		/* Block all but "shutdown" signals while waiting */
+		sigset_t oldset;
+		unsigned long irqflags;
+
+		spin_lock_irqsave(&current->sighand->siglock, irqflags);
+		oldset = current->blocked;
+		siginitsetinv(&current->blocked, SHUTDOWN_SIGS & ~oldset.sig[0]);
+		recalc_sigpending();
+		spin_unlock_irqrestore(&current->sighand->siglock, irqflags);
+
+		wait_event_interruptible(wq->queue, wq->name.name == NULL);
+
+		spin_lock_irqsave(&current->sighand->siglock, irqflags);
+		current->blocked = oldset;
+		recalc_sigpending();
+		spin_unlock_irqrestore(&current->sighand->siglock, irqflags);
+	} else {
+		DPRINTK("skipped sleeping");
+	}
+
+	status = wq->status;
+
+	/*
+	 * For direct and offset mounts we need to track the requester's
+	 * uid and gid in the dentry info struct. This is so it can be
+	 * supplied, on request, by the misc device ioctl interface.
+	 * This is needed during daemon resatart when reconnecting
+	 * to existing, active, autofs mounts. The uid and gid (and
+	 * related string values) may be used for macro substitution
+	 * in autofs mount maps.
+	 */
+	if (!status) {
+		struct autofs_info *ino;
+		struct dentry *de = NULL;
+
+		/* direct mount or browsable map */
+		ino = autofs4_dentry_ino(dentry);
+		if (!ino) {
+			/* If not lookup actual dentry used */
+			de = d_lookup(dentry->d_parent, &dentry->d_name);
+			if (de)
+				ino = autofs4_dentry_ino(de);
+		}
+
+		/* Set mount requester */
+		if (ino) {
+			spin_lock(&sbi->fs_lock);
+			ino->uid = wq->uid;
+			ino->gid = wq->gid;
+			spin_unlock(&sbi->fs_lock);
+		}
+
+		if (de)
+			dput(de);
+	}
+
+	/* Are we the last process to need status? */
+	mutex_lock(&sbi->wq_mutex);
+	if (!--wq->wait_ctr)
+		kfree(wq);
+	mutex_unlock(&sbi->wq_mutex);
+
+	return status;
+}
+
+
+int autofs4_wait_release(struct autofs_sb_info *sbi, autofs_wqt_t wait_queue_token, int status)
+{
+	struct autofs_wait_queue *wq, **wql;
+
+	mutex_lock(&sbi->wq_mutex);
+	for (wql = &sbi->queues; (wq = *wql) != NULL; wql = &wq->next) {
+		if (wq->wait_queue_token == wait_queue_token)
+			break;
+	}
+
+	if (!wq) {
+		mutex_unlock(&sbi->wq_mutex);
+		return -EINVAL;
+	}
+
+	*wql = wq->next;	/* Unlink from chain */
+	kfree(wq->name.name);
+	wq->name.name = NULL;	/* Do not wait on this queue */
+	wq->status = status;
+	wake_up_interruptible(&wq->queue);
+	if (!--wq->wait_ctr)
+		kfree(wq);
+	mutex_unlock(&sbi->wq_mutex);
+
+	return 0;
+}
+