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COPYING	17.58 KB	-rw-r--r--
COPYRIGHT	778 B	-rw-r--r--
CREDITS	319 B	-rw-r--r--
INSTALL	6.48 KB	-rw-r--r--
README	1.75 KB	-rw-r--r--
README.active-restart	4.79 KB	-rw-r--r--
README.amd-maps	4.09 KB	-rw-r--r--
README.autofs-schema	681 B	-rw-r--r--
README.changer	1.2 KB	-rw-r--r--
README.ncpfs	3.26 KB	-rw-r--r--
README.replicated-server	1.67 KB	-rw-r--r--
README.smbfs	547 B	-rw-r--r--
README.v5.release	2.89 KB	-rw-r--r--
autofs.schema	830 B	-rw-r--r--
autofs.schema.new	771 B	-rw-r--r--
autofs4-2.6.18-v5-update-20090...	109.89 KB	-rw-r--r--
autofs4-2.6.19-v5-update-20090...	103.75 KB	-rw-r--r--
autofs4-2.6.20-v5-update-20090...	102.72 KB	-rw-r--r--
autofs4-2.6.21-v5-update-20090...	101.85 KB	-rw-r--r--
autofs4-2.6.22-v5-update-20090...	101.83 KB	-rw-r--r--
autofs4-2.6.22.17-v5-update-20...	101.9 KB	-rw-r--r--
autofs4-2.6.23-v5-update-20090...	100.79 KB	-rw-r--r--
autofs4-2.6.24-v5-update-20090...	100.78 KB	-rw-r--r--
autofs4-2.6.24.4-v5-update-200...	100.43 KB	-rw-r--r--
autofs4-2.6.25-v5-update-20090...	100.97 KB	-rw-r--r--
autofs4-2.6.26-v5-update-20090...	100.73 KB	-rw-r--r--
autofs4-2.6.27-v5-update-20090...	60.28 KB	-rw-r--r--
autofs4-2.6.28-v5-update-20090...	28.46 KB	-rw-r--r--
autofs4-2.6.29-v5-update-20090...	7.03 KB	-rw-r--r--
ldap-automount-auto.direct	1.14 KB	-rw-r--r--
ldap-automount-auto.indirect	544 B	-rw-r--r--
ldap-automount-auto.master	348 B	-rw-r--r--
ldap-automount-rfc2307-bis-aut...	1.5 KB	-rw-r--r--
ldap-automount-rfc2307-bis-aut...	816 B	-rw-r--r--
ldap-automount-rfc2307-bis-aut...	482 B	-rw-r--r--
ldap-automount-rfc2307-bis-old...	570 B	-rw-r--r--
ldap-nis-auto.direct	1.33 KB	-rw-r--r--
ldap-nis-auto.indirect	654 B	-rw-r--r--
ldap-nis-auto.master	420 B	-rw-r--r--
util-linux-2.12a-flock.patch	641 B	-rw-r--r--
util-linux-2.12q-flock.patch	554 B	-rw-r--r--

Code Editor : autofs4-2.6.18-v5-update-20090903.patch

--- linux-2.6.18.orig/fs/autofs4/root.c
+++ linux-2.6.18/fs/autofs4/root.c
@@ -26,25 +26,25 @@ static int autofs4_dir_rmdir(struct inod
 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 int autofs4_dir_close(struct inode *inode, struct file *file);
-static int autofs4_dir_readdir(struct file * filp, void * dirent, filldir_t filldir);
-static int autofs4_root_readdir(struct file * filp, void * dirent, filldir_t filldir);
 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	= autofs4_root_readdir,
+	.readdir	= dcache_readdir,
 	.ioctl		= autofs4_root_ioctl,
 };
 
 const struct file_operations autofs4_dir_operations = {
 	.open		= autofs4_dir_open,
-	.release	= autofs4_dir_close,
+	.release	= dcache_dir_close,
 	.read		= generic_read_dir,
-	.readdir	= autofs4_dir_readdir,
+	.readdir	= dcache_readdir,
 };
 
 struct inode_operations autofs4_indirect_root_inode_operations = {
@@ -71,42 +71,10 @@ struct inode_operations autofs4_dir_inod
 	.rmdir		= autofs4_dir_rmdir,
 };
 
-static int autofs4_root_readdir(struct file *file, void *dirent,
-				filldir_t filldir)
-{
-	struct autofs_sb_info *sbi = autofs4_sbi(file->f_dentry->d_sb);
-	int oz_mode = autofs4_oz_mode(sbi);
-
-	DPRINTK("called, filp->f_pos = %lld", file->f_pos);
-
-	/*
-	 * Don't set reghost flag if:
-	 * 1) f_pos is larger than zero -- we've already been here.
-	 * 2) we haven't even enabled reghosting in the 1st place.
-	 * 3) this is the daemon doing a readdir
-	 */
-	if (oz_mode && file->f_pos == 0 && sbi->reghost_enabled)
-		sbi->needs_reghost = 1;
-
-	DPRINTK("needs_reghost = %d", sbi->needs_reghost);
-
-	return dcache_readdir(file, dirent, filldir);
-}
-
 static int autofs4_dir_open(struct inode *inode, struct file *file)
 {
 	struct dentry *dentry = file->f_dentry;
-	struct vfsmount *mnt = file->f_vfsmnt;
 	struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
-	struct dentry *cursor;
-	int status;
-
-	status = dcache_dir_open(inode, file);
-	if (status)
-		goto out;
-
-	cursor = file->private_data;
-	cursor->d_fsdata = NULL;
 
 	DPRINTK("file=%p dentry=%p %.*s",
 		file, dentry, dentry->d_name.len, dentry->d_name.name);
@@ -114,155 +82,30 @@ static int autofs4_dir_open(struct inode
 	if (autofs4_oz_mode(sbi))
 		goto out;
 
-	if (autofs4_ispending(dentry)) {
-		DPRINTK("dentry busy");
-		dcache_dir_close(inode, file);
-		status = -EBUSY;
-		goto out;
-	}
-
-	status = -ENOENT;
-	if (!d_mountpoint(dentry) && dentry->d_op && dentry->d_op->d_revalidate) {
-		struct nameidata nd;
-		int empty, ret;
-
-		/* In case there are stale directory dentrys from a failed mount */
-		spin_lock(&dcache_lock);
-		empty = list_empty(&dentry->d_subdirs);
+	/*
+	 * 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.
+	 */
+	if (!d_mountpoint(dentry) && __simple_empty(dentry)) {
 		spin_unlock(&dcache_lock);
-
-		if (!empty)
-			d_invalidate(dentry);
-
-		nd.flags = LOOKUP_DIRECTORY;
-		ret = (dentry->d_op->d_revalidate)(dentry, &nd);
-
-		if (!ret) {
-			dcache_dir_close(inode, file);
-			goto out;
-		}
-	}
-
-	if (d_mountpoint(dentry)) {
-		struct file *fp = NULL;
-		struct vfsmount *fp_mnt = mntget(mnt);
-		struct dentry *fp_dentry = dget(dentry);
-
-		if (!autofs4_follow_mount(&fp_mnt, &fp_dentry)) {
-			dput(fp_dentry);
-			mntput(fp_mnt);
-			dcache_dir_close(inode, file);
-			goto out;
-		}
-
-		fp = dentry_open(fp_dentry, fp_mnt, file->f_flags);
-		status = PTR_ERR(fp);
-		if (IS_ERR(fp)) {
-			dcache_dir_close(inode, file);
-			goto out;
-		}
-		cursor->d_fsdata = fp;
-	}
-	return 0;
-out:
-	return status;
-}
-
-static int autofs4_dir_close(struct inode *inode, struct file *file)
-{
-	struct dentry *dentry = file->f_dentry;
-	struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
-	struct dentry *cursor = file->private_data;
-	int status = 0;
-
-	DPRINTK("file=%p dentry=%p %.*s",
-		file, dentry, dentry->d_name.len, dentry->d_name.name);
-
-	if (autofs4_oz_mode(sbi))
-		goto out;
-
-	if (autofs4_ispending(dentry)) {
-		DPRINTK("dentry busy");
-		status = -EBUSY;
-		goto out;
-	}
-
-	if (d_mountpoint(dentry)) {
-		struct file *fp = cursor->d_fsdata;
-		if (!fp) {
-			status = -ENOENT;
-			goto out;
-		}
-		filp_close(fp, current->files);
-	}
-out:
-	dcache_dir_close(inode, file);
-	return status;
-}
-
-static int autofs4_dir_readdir(struct file *file, void *dirent, filldir_t filldir)
-{
-	struct dentry *dentry = file->f_dentry;
-	struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
-	struct dentry *cursor = file->private_data;
-	int status;
-
-	DPRINTK("file=%p dentry=%p %.*s",
-		file, dentry, dentry->d_name.len, dentry->d_name.name);
-
-	if (autofs4_oz_mode(sbi))
-		goto out;
-
-	if (autofs4_ispending(dentry)) {
-		DPRINTK("dentry busy");
-		return -EBUSY;
+		return -ENOENT;
 	}
+	spin_unlock(&dcache_lock);
 
-	if (d_mountpoint(dentry)) {
-		struct file *fp = cursor->d_fsdata;
-
-		if (!fp)
-			return -ENOENT;
-
-		if (!fp->f_op || !fp->f_op->readdir)
-			goto out;
-
-		status = vfs_readdir(fp, filldir, dirent);
-		file->f_pos = fp->f_pos;
-		if (status)
-			autofs4_copy_atime(file, fp);
-		return status;
-	}
 out:
-	return dcache_readdir(file, dirent, filldir);
+	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 = 0;
-
-	/* Block on any pending expiry here; invalidate the dentry
-           when expiration is done to trigger mount request with a new
-           dentry */
-	if (ino && (ino->flags & AUTOFS_INF_EXPIRING)) {
-		DPRINTK("waiting for expire %p name=%.*s",
-			 dentry, dentry->d_name.len, dentry->d_name.name);
-
-		status = autofs4_wait(sbi, dentry, NFY_NONE);
-
-		DPRINTK("expire done status=%d", status);
-
-		/*
-		 * If the directory still exists the mount request must
-		 * continue otherwise it can't be followed at the right
-		 * time during the walk.
-		 */
-		status = d_invalidate(dentry);
-		if (status != -EBUSY)
-			return -ENOENT;
-	}
+	int status;
 
 	DPRINTK("dentry=%p %.*s ino=%p",
 		 dentry, dentry->d_name.len, dentry->d_name.name, dentry->d_inode);
@@ -279,9 +122,6 @@ static int try_to_fill_dentry(struct den
 
 		DPRINTK("mount done status=%d", status);
 
-		if (status && dentry->d_inode)
-			return status; /* Try to get the kernel to invalidate this dentry */
-
 		/* Turn this into a real negative dentry? */
 		if (status == -ENOENT) {
 			spin_lock(&dentry->d_lock);
@@ -293,7 +133,8 @@ static int try_to_fill_dentry(struct den
 			return status;
 		}
 	/* Trigger mount for path component or follow link */
-	} else if (flags & (LOOKUP_CONTINUE | LOOKUP_DIRECTORY) ||
+	} 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);
@@ -320,7 +161,8 @@ static int try_to_fill_dentry(struct den
 	spin_lock(&dentry->d_lock);
 	dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
 	spin_unlock(&dentry->d_lock);
-	return status;
+
+	return 0;
 }
 
 /* For autofs direct mounts the follow link triggers the mount */
@@ -335,50 +177,62 @@ static void *autofs4_follow_link(struct 
 	DPRINTK("dentry=%p %.*s oz_mode=%d nd->flags=%d",
 		dentry, dentry->d_name.len, dentry->d_name.name, oz_mode,
 		nd->flags);
-
-	/* If it's our master or we shouldn't trigger a mount we're done */
-	lookup_type = nd->flags & (LOOKUP_CONTINUE | LOOKUP_DIRECTORY);
-	if (oz_mode || !lookup_type)
+	/*
+	 * For an expire of a covered direct or offset mount we need
+	 * to beeak 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->mnt, &nd->dentry))
+				goto done;
+			goto follow;
+		}
+		spin_unlock(&sbi->fs_lock);
 		goto done;
+	}
 
-	/* If an expire request is pending wait for it. */
-	if (ino && (ino->flags & AUTOFS_INF_EXPIRING)) {
-		DPRINTK("waiting for active request %p name=%.*s",
-			dentry, dentry->d_name.len, dentry->d_name.name);
-
-		status = autofs4_wait(sbi, dentry, NFY_NONE);
+	/* If an expire request is pending everyone must wait. */
+	autofs4_expire_wait(dentry);
 
-		DPRINTK("request done status=%d", status);
-	}
+	/* 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.
+	 * 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 (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) {
+	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;
 
-		/*
-		 * The mount succeeded but if there is no root mount
-		 * it must be an autofs multi-mount with no root offset
-		 * so we don't need to follow the mount.
-		 */
-		if (d_mountpoint(dentry)) {
-			if (!autofs4_follow_mount(&nd->mnt, &nd->dentry)) {
-				status = -ENOENT;
-				goto out_error;
-			}
-		}
-
-		goto done;
+		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->mnt, &nd->dentry)) {
+			status = -ENOENT;
+			goto out_error;
+		}
+	}
 
 done:
 	return NULL;
@@ -400,14 +254,36 @@ static int autofs4_revalidate(struct den
 	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 = 0;
+	int status;
 
 	/* Pending dentry */
+	spin_lock(&sbi->fs_lock);
 	if (autofs4_ispending(dentry)) {
-		if (!oz_mode)
-			status = try_to_fill_dentry(dentry, flags);
-		return !status;
+		/* 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)
@@ -421,9 +297,20 @@ static int autofs4_revalidate(struct den
 		DPRINTK("dentry=%p %.*s, emptydir",
 			 dentry, dentry->d_name.len, dentry->d_name.name);
 		spin_unlock(&dcache_lock);
-		if (!oz_mode)
-			status = try_to_fill_dentry(dentry, flags);
-		return !status;
+
+		/* 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);
 
@@ -440,6 +327,17 @@ void autofs4_dentry_release(struct dentr
 	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;
 
@@ -459,10 +357,116 @@ static struct dentry_operations autofs4_
 	.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",
@@ -478,29 +482,67 @@ static struct dentry *autofs4_lookup(str
 	DPRINTK("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d",
 		 current->pid, process_group(current), sbi->catatonic, oz_mode);
 
-	/*
-	 * Mark the dentry incomplete, but add it. This is needed so
-	 * that the VFS layer knows about the dentry, and we can count
-	 * on catching any lookups through the revalidate.
-	 *
-	 * Let all the hard work be done by the revalidate function that
-	 * needs to be able to do this anyway..
-	 *
-	 * We need to do this before we release the directory semaphore.
-	 */
-	dentry->d_op = &autofs4_root_dentry_operations;
+	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);
-	}
-	dentry->d_fsdata = NULL;
-	d_add(dentry, NULL);
-
-	if (dentry->d_op && dentry->d_op->d_revalidate) {
-		mutex_unlock(&dir->i_mutex);
-		(dentry->d_op->d_revalidate)(dentry, nd);
+		if (dentry->d_op && dentry->d_op->d_revalidate)
+			(dentry->d_op->d_revalidate)(dentry, nd);
 		mutex_lock(&dir->i_mutex);
 	}
 
@@ -515,19 +557,47 @@ static struct dentry *autofs4_lookup(str
 			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 even if the dentry is positive.  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.
+	 * 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 (dentry->d_inode && d_unhashed(dentry))
-		return ERR_PTR(-ENOENT);
+	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;
 }
@@ -549,21 +619,32 @@ static int autofs4_dir_symlink(struct in
 		return -EACCES;
 
 	ino = autofs4_init_ino(ino, sbi, S_IFLNK | 0555);
-	if (ino == NULL)
-		return -ENOSPC;
+	if (!ino)
+		return -ENOMEM;
 
-	ino->size = strlen(symname);
-	ino->u.symlink = cp = kmalloc(ino->size + 1, GFP_KERNEL);
+	spin_lock(&sbi->lookup_lock);
+	if (!list_empty(&ino->active))
+		list_del_init(&ino->active);
+	spin_unlock(&sbi->lookup_lock);
 
-	if (cp == NULL) {
-		kfree(ino);
-		return -ENOSPC;
+	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);
-	d_instantiate(dentry, inode);
+	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;
@@ -578,6 +659,7 @@ static int autofs4_dir_symlink(struct in
 		atomic_inc(&p_ino->count);
 	ino->inode = inode;
 
+	ino->u.symlink = cp;
 	dir->i_mtime = CURRENT_TIME;
 
 	return 0;
@@ -589,9 +671,9 @@ static int autofs4_dir_symlink(struct in
  * 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 since the unlink is probably the result of an expire.
- * We simply d_drop it, which allows the dentry lookup to remount it
- * if necessary.
+ * 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.
@@ -620,7 +702,15 @@ static int autofs4_dir_unlink(struct ino
 
 	dir->i_mtime = CURRENT_TIME;
 
-	d_drop(dentry);
+	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;
 }
@@ -631,6 +721,9 @@ static int autofs4_dir_rmdir(struct inod
 	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;
 
@@ -639,6 +732,10 @@ static int autofs4_dir_rmdir(struct inod
 		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);
@@ -673,11 +770,21 @@ static int autofs4_dir_mkdir(struct inod
 		dentry, dentry->d_name.len, dentry->d_name.name);
 
 	ino = autofs4_init_ino(ino, sbi, S_IFDIR | 0555);
-	if (ino == NULL)
-		return -ENOSPC;
+	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);
-	d_instantiate(dentry, inode);
+	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;
@@ -729,44 +836,6 @@ static inline int autofs4_get_protosubve
 }
 
 /*
- * Tells the daemon whether we need to reghost or not. Also, clears
- * the reghost_needed flag.
- */
-static inline int autofs4_ask_reghost(struct autofs_sb_info *sbi, int __user *p)
-{
-	int status;
-
-	DPRINTK("returning %d", sbi->needs_reghost);
-
-	status = put_user(sbi->needs_reghost, p);
-	if ( status )
-		return status;
-
-	sbi->needs_reghost = 0;
-	return 0;
-}
-
-/*
- * Enable / Disable reghosting ioctl() operation
- */
-static inline int autofs4_toggle_reghost(struct autofs_sb_info *sbi, int __user *p)
-{
-	int status;
-	int val;
-
-	status = get_user(val, p);
-
-	DPRINTK("reghost = %d", val);
-
-	if (status)
-		return status;
-
-	/* turn on/off reghosting, with the val */
-	sbi->reghost_enabled = val;
-	return 0;
-}
-
-/*
 * Tells the daemon whether it can umount the autofs mount.
 */
 static inline int autofs4_ask_umount(struct vfsmount *mnt, int __user *p)
@@ -830,11 +899,6 @@ static int autofs4_root_ioctl(struct ino
 	case AUTOFS_IOC_SETTIMEOUT:
 		return autofs4_get_set_timeout(sbi, p);
 
-	case AUTOFS_IOC_TOGGLEREGHOST:
-		return autofs4_toggle_reghost(sbi, p);
-	case AUTOFS_IOC_ASKREGHOST:
-		return autofs4_ask_reghost(sbi, p);
-
 	case AUTOFS_IOC_ASKUMOUNT:
 		return autofs4_ask_umount(filp->f_vfsmnt, p);
 
--- linux-2.6.18.orig/fs/namei.c
+++ linux-2.6.18/fs/namei.c
@@ -372,6 +372,29 @@ void release_open_intent(struct nameidat
 		fput(nd->intent.open.file);
 }
 
+static inline struct dentry *do_revalidate(struct dentry *dentry, struct nameidata *nd)
+{
+	int status = dentry->d_op->d_revalidate(dentry, nd);
+	if (unlikely(status <= 0)) {
+		/*
+		 * The dentry failed validation.
+		 * If d_revalidate returned 0 attempt to invalidate
+		 * the dentry otherwise d_revalidate is asking us
+		 * to return a fail status.
+		 */
+		if (!status) {
+			if (!d_invalidate(dentry)) {
+				dput(dentry);
+				dentry = NULL;
+			}
+		} else {
+			dput(dentry);
+			dentry = ERR_PTR(status);
+		}
+	}
+	return dentry;
+}
+
 /*
  * Internal lookup() using the new generic dcache.
  * SMP-safe
@@ -386,12 +409,9 @@ static struct dentry * cached_lookup(str
 	if (!dentry)
 		dentry = d_lookup(parent, name);
 
-	if (dentry && dentry->d_op && dentry->d_op->d_revalidate) {
-		if (!dentry->d_op->d_revalidate(dentry, nd) && !d_invalidate(dentry)) {
-			dput(dentry);
-			dentry = NULL;
-		}
-	}
+	if (dentry && dentry->d_op && dentry->d_op->d_revalidate)
+		dentry = do_revalidate(dentry, nd);
+
 	return dentry;
 }
 
@@ -484,10 +504,9 @@ static struct dentry * real_lookup(struc
 	 */
 	mutex_unlock(&dir->i_mutex);
 	if (result->d_op && result->d_op->d_revalidate) {
-		if (!result->d_op->d_revalidate(result, nd) && !d_invalidate(result)) {
-			dput(result);
+		result = do_revalidate(result, nd);
+		if (!result)
 			result = ERR_PTR(-ENOENT);
-		}
 	}
 	return result;
 }
@@ -767,12 +786,12 @@ need_lookup:
 	goto done;
 
 need_revalidate:
-	if (dentry->d_op->d_revalidate(dentry, nd))
-		goto done;
-	if (d_invalidate(dentry))
-		goto done;
-	dput(dentry);
-	goto need_lookup;
+	dentry = do_revalidate(dentry, nd);
+	if (!dentry)
+		goto need_lookup;
+	if (IS_ERR(dentry))
+		goto fail;
+	goto done;
 
 fail:
 	return PTR_ERR(dentry);
--- linux-2.6.18.orig/fs/autofs/init.c
+++ linux-2.6.18/fs/autofs/init.c
@@ -24,7 +24,7 @@ static struct file_system_type autofs_fs
 	.owner		= THIS_MODULE,
 	.name		= "autofs",
 	.get_sb		= autofs_get_sb,
-	.kill_sb	= kill_anon_super,
+	.kill_sb	= autofs_kill_sb,
 };
 
 static int __init init_autofs_fs(void)
--- linux-2.6.18.orig/fs/autofs/inode.c
+++ linux-2.6.18/fs/autofs/inode.c
@@ -19,11 +19,20 @@
 #include "autofs_i.h"
 #include <linux/module.h>
 
-static void autofs_put_super(struct super_block *sb)
+void autofs4_kill_sb(struct super_block *sb)
 {
 	struct autofs_sb_info *sbi = autofs_sbi(sb);
 	unsigned int n;
 
+	/*
+	 * 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;
+
 	if ( !sbi->catatonic )
 		autofs_catatonic_mode(sbi); /* Free wait queues, close pipe */
 
@@ -35,14 +44,15 @@ static void autofs_put_super(struct supe
 
 	kfree(sb->s_fs_info);
 
+out_kill_sb:
 	DPRINTK(("autofs: shutting down\n"));
+	kill_anon_super(sb);
 }
 
 static void autofs_read_inode(struct inode *inode);
 
 static struct super_operations autofs_sops = {
 	.read_inode	= autofs_read_inode,
-	.put_super	= autofs_put_super,
 	.statfs		= simple_statfs,
 };
 
@@ -136,7 +146,8 @@ int autofs_fill_super(struct super_block
 
 	s->s_fs_info = sbi;
 	sbi->magic = AUTOFS_SBI_MAGIC;
-	sbi->catatonic = 0;
+	sbi->pipe = NULL;
+	sbi->catatonic = 1;
 	sbi->exp_timeout = 0;
 	sbi->oz_pgrp = process_group(current);
 	autofs_initialize_hash(&sbi->dirhash);
@@ -180,6 +191,7 @@ int autofs_fill_super(struct super_block
 	if ( !pipe->f_op || !pipe->f_op->write )
 		goto fail_fput;
 	sbi->pipe = pipe;
+	sbi->catatonic = 0;
 
 	/*
 	 * Success! Install the root dentry now to indicate completion.
@@ -198,6 +210,7 @@ fail_iput:
 	iput(root_inode);
 fail_free:
 	kfree(sbi);
+	s->s_fs_info = NULL;
 fail_unlock:
 	return -EINVAL;
 }
--- linux-2.6.18.orig/fs/autofs/autofs_i.h
+++ linux-2.6.18/fs/autofs/autofs_i.h
@@ -151,6 +151,7 @@ extern const struct file_operations auto
 /* Initializing function */
 
 int autofs_fill_super(struct super_block *, void *, int);
+void autofs_kill_sb(struct super_block *);
 
 /* Queue management functions */
 
--- linux-2.6.18.orig/fs/autofs4/autofs_i.h
+++ linux-2.6.18/fs/autofs4/autofs_i.h
@@ -14,6 +14,7 @@
 /* Internal header file for autofs */
 
 #include <linux/auto_fs4.h>
+#include <linux/auto_dev-ioctl.h>
 #include <linux/mutex.h>
 #include <linux/list.h>
 
@@ -21,6 +22,9 @@
 #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>
@@ -35,11 +39,27 @@
 /* #define DEBUG */
 
 #ifdef DEBUG
-#define DPRINTK(fmt,args...) do { printk(KERN_DEBUG "pid %d: %s: " fmt "\n" , current->pid , __FUNCTION__ , ##args); } while(0)
+#define DPRINTK(fmt, args...)				\
+do {							\
+	printk(KERN_DEBUG "pid %d: %s: " fmt "\n",	\
+		current->pid, __FUNCTION__, ##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, __FUNCTION__, ##args);	\
+} while (0)
+
+#define AUTOFS_ERROR(fmt, args...)			\
+do {							\
+	printk(KERN_ERR "pid %d: %s: " fmt "\n",	\
+		current->pid, __FUNCTION__, ##args);	\
+} while (0)
+
 #define AUTOFS_SUPER_MAGIC 0x0187
 
 /* Unified info structure.  This is pointed to by both the dentry and
@@ -54,10 +74,18 @@ struct autofs_info {
 
 	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;
 
@@ -68,15 +96,14 @@ struct autofs_info {
 };
 
 #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 */
-	unsigned int hash;
-	unsigned int len;
-	char *name;
+	struct qstr name;
 	u32 dev;
 	u64 ino;
 	uid_t uid;
@@ -85,18 +112,13 @@ struct autofs_wait_queue {
 	pid_t tgid;
 	/* This is for status reporting upon return */
 	int status;
-	atomic_t wait_ctr;
+	unsigned int wait_ctr;
 };
 
 #define AUTOFS_SBI_MAGIC 0x6d4a556d
 
-#define AUTOFS_TYPE_INDIRECT     0x0001
-#define AUTOFS_TYPE_DIRECT       0x0002
-#define AUTOFS_TYPE_OFFSET       0x0004
-
 struct autofs_sb_info {
 	u32 magic;
-	struct dentry *root;
 	int pipefd;
 	struct file *pipe;
 	pid_t oz_pgrp;
@@ -113,6 +135,9 @@ struct autofs_sb_info {
 	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)
@@ -137,18 +162,14 @@ static inline int autofs4_oz_mode(struct
 static inline int autofs4_ispending(struct dentry *dentry)
 {
 	struct autofs_info *inf = autofs4_dentry_ino(dentry);
-	int pending = 0;
 
 	if (dentry->d_flags & DCACHE_AUTOFS_PENDING)
 		return 1;
 
-	if (inf) {
-		spin_lock(&inf->sbi->fs_lock);
-		pending = inf->flags & AUTOFS_INF_EXPIRING;
-		spin_unlock(&inf->sbi->fs_lock);
-	}
+	if (inf->flags & AUTOFS_INF_EXPIRING)
+		return 1;
 
-	return pending;
+	return 0;
 }
 
 static inline void autofs4_copy_atime(struct file *src, struct file *dst)
@@ -162,11 +183,23 @@ 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_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 */
 
@@ -231,4 +264,4 @@ out:
 }
 
 void autofs4_dentry_release(struct dentry *);
-
+extern void autofs4_kill_sb(struct super_block *);
--- linux-2.6.18.orig/fs/autofs4/init.c
+++ linux-2.6.18/fs/autofs4/init.c
@@ -24,16 +24,25 @@ static struct file_system_type autofs_fs
 	.owner		= THIS_MODULE,
 	.name		= "autofs",
 	.get_sb		= autofs_get_sb,
-	.kill_sb	= kill_anon_super,
+	.kill_sb	= autofs4_kill_sb,
 };
 
 static int __init init_autofs4_fs(void)
 {
-	return register_filesystem(&autofs_fs_type);
+	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);
 }
 
--- linux-2.6.18.orig/fs/autofs4/inode.c
+++ linux-2.6.18/fs/autofs4/inode.c
@@ -24,8 +24,10 @@
 
 static void ino_lnkfree(struct autofs_info *ino)
 {
-	kfree(ino->u.symlink);
-	ino->u.symlink = NULL;
+	if (ino->u.symlink) {
+		kfree(ino->u.symlink);
+		ino->u.symlink = NULL;
+	}
 }
 
 struct autofs_info *autofs4_init_ino(struct autofs_info *ino,
@@ -41,14 +43,20 @@ struct autofs_info *autofs4_init_ino(str
 	if (ino == NULL)
 		return NULL;
 
-	ino->flags = 0;
-	ino->mode = mode;
-	ino->inode = NULL;
-	ino->dentry = NULL;
-	ino->size = 0;
+	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;
-	atomic_set(&ino->count, 0);
 
 	ino->sbi = sbi;
 
@@ -95,9 +103,12 @@ void autofs4_free_ino(struct autofs_info
  */
 static void autofs4_force_release(struct autofs_sb_info *sbi)
 {
-	struct dentry *this_parent = sbi->root;
+	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;
@@ -126,7 +137,7 @@ resume:
 		spin_lock(&dcache_lock);
 	}
 
-	if (this_parent != sbi->root) {
+	if (this_parent != sbi->sb->s_root) {
 		struct dentry *dentry = this_parent;
 
 		next = this_parent->d_u.d_child.next;
@@ -139,29 +150,34 @@ resume:
 		goto resume;
 	}
 	spin_unlock(&dcache_lock);
-
-	dput(sbi->root);
-	sbi->root = NULL;
 	shrink_dcache_sb(sbi->sb);
-
-	return;
 }
 
-static void autofs4_put_super(struct super_block *sb)
+void autofs4_kill_sb(struct super_block *sb)
 {
 	struct autofs_sb_info *sbi = autofs4_sbi(sb);
 
-	sb->s_fs_info = NULL;
+	/*
+	 * 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;
 
-	if ( !sbi->catatonic )
-		autofs4_catatonic_mode(sbi); /* Free wait queues, close pipe */
+	/* 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)
@@ -177,9 +193,9 @@ static int autofs4_show_options(struct s
 	seq_printf(m, ",minproto=%d", sbi->min_proto);
 	seq_printf(m, ",maxproto=%d", sbi->max_proto);
 
-	if (sbi->type & AUTOFS_TYPE_OFFSET)
+	if (autofs_type_offset(sbi->type))
 		seq_printf(m, ",offset");
-	else if (sbi->type & AUTOFS_TYPE_DIRECT)
+	else if (autofs_type_direct(sbi->type))
 		seq_printf(m, ",direct");
 	else
 		seq_printf(m, ",indirect");
@@ -188,7 +204,6 @@ static int autofs4_show_options(struct s
 }
 
 static struct super_operations autofs4_sops = {
-	.put_super	= autofs4_put_super,
 	.statfs		= simple_statfs,
 	.show_options	= autofs4_show_options,
 };
@@ -266,13 +281,13 @@ static int parse_options(char *options, 
 			*maxproto = option;
 			break;
 		case Opt_indirect:
-			*type = AUTOFS_TYPE_INDIRECT;
+			set_autofs_type_indirect(type);
 			break;
 		case Opt_direct:
-			*type = AUTOFS_TYPE_DIRECT;
+			set_autofs_type_direct(type);
 			break;
 		case Opt_offset:
-			*type = AUTOFS_TYPE_DIRECT | AUTOFS_TYPE_OFFSET;
+			set_autofs_type_offset(type);
 			break;
 		default:
 			return 1;
@@ -314,20 +329,23 @@ int autofs4_fill_super(struct super_bloc
 
 	s->s_fs_info = sbi;
 	sbi->magic = AUTOFS_SBI_MAGIC;
-	sbi->root = NULL;
 	sbi->pipefd = -1;
-	sbi->catatonic = 0;
+	sbi->pipe = NULL;
+	sbi->catatonic = 1;
 	sbi->exp_timeout = 0;
 	sbi->oz_pgrp = process_group(current);
 	sbi->sb = s;
 	sbi->version = 0;
 	sbi->sub_version = 0;
-	sbi->type = 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;
@@ -362,7 +380,7 @@ int autofs4_fill_super(struct super_bloc
 	}
 
 	root_inode->i_fop = &autofs4_root_operations;
-	root_inode->i_op = sbi->type & AUTOFS_TYPE_DIRECT ?
+	root_inode->i_op = autofs_type_trigger(sbi->type) ?
 			&autofs4_direct_root_inode_operations :
 			&autofs4_indirect_root_inode_operations;
 
@@ -394,13 +412,7 @@ int autofs4_fill_super(struct super_bloc
 		goto fail_fput;
 	sbi->pipe = pipe;
 	sbi->pipefd = pipefd;
-
-	/*
-	 * Take a reference to the root dentry so we get a chance to
-	 * clean up the dentry tree on umount.
-	 * See autofs4_force_release.
-	 */
-	sbi->root = dget(root);
+	sbi->catatonic = 0;
 
 	/*
 	 * Success! Install the root dentry now to indicate completion.
@@ -425,6 +437,7 @@ fail_ino:
 	kfree(ino);
 fail_free:
 	kfree(sbi);
+	s->s_fs_info = NULL;
 fail_unlock:
 	return -EINVAL;
 }
--- linux-2.6.18.orig/fs/autofs4/waitq.c
+++ linux-2.6.18/fs/autofs4/waitq.c
@@ -28,6 +28,12 @@ void autofs4_catatonic_mode(struct autof
 {
 	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;
@@ -36,15 +42,17 @@ void autofs4_catatonic_mode(struct autof
 	while (wq) {
 		nwq = wq->next;
 		wq->status = -ENOENT; /* Magic is gone - report failure */
-		kfree(wq->name);
-		wq->name = NULL;
+		if (wq->name.name) {
+			kfree(wq->name.name);
+			wq->name.name = NULL;
+		}
+		wq->wait_ctr--;
 		wake_up_interruptible(&wq->queue);
 		wq = nwq;
 	}
-	if (sbi->pipe) {
-		fput(sbi->pipe);	/* Close the pipe */
-		sbi->pipe = NULL;
-	}
+	fput(sbi->pipe);	/* Close the pipe */
+	sbi->pipe = NULL;
+	mutex_unlock(&sbi->wq_mutex);
 	shrink_dcache_sb(sbi->sb);
 }
 
@@ -87,11 +95,16 @@ static void autofs4_notify_daemon(struct
 				 struct autofs_wait_queue *wq,
 				 int type)
 {
-	union autofs_packet_union pkt;
+	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->len, wq->name, type);
+		wq->wait_queue_token, wq->name.len, wq->name.name, type);
 
 	memset(&pkt,0,sizeof pkt); /* For security reasons */
 
@@ -101,26 +114,26 @@ static void autofs4_notify_daemon(struct
 	/* Kernel protocol v4 missing and expire packets */
 	case autofs_ptype_missing:
 	{
-		struct autofs_packet_missing *mp = &pkt.missing;
+		struct autofs_packet_missing *mp = &pkt.v4_pkt.missing;
 
 		pktsz = sizeof(*mp);
 
 		mp->wait_queue_token = wq->wait_queue_token;
-		mp->len = wq->len;
-		memcpy(mp->name, wq->name, wq->len);
-		mp->name[wq->len] = '\0';
+		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.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->len;
-		memcpy(ep->name, wq->name, wq->len);
-		ep->name[wq->len] = '\0';
+		ep->len = wq->name.len;
+		memcpy(ep->name, wq->name.name, wq->name.len);
+		ep->name[wq->name.len] = '\0';
 		break;
 	}
 	/*
@@ -132,14 +145,14 @@ static void autofs4_notify_daemon(struct
 	case autofs_ptype_missing_direct:
 	case autofs_ptype_expire_direct:
 	{
-		struct autofs_v5_packet *packet = &pkt.v5_packet;
+		struct autofs_v5_packet *packet = &pkt.v5_pkt.v5_packet;
 
 		pktsz = sizeof(*packet);
 
 		packet->wait_queue_token = wq->wait_queue_token;
-		packet->len = wq->len;
-		memcpy(packet->name, wq->name, wq->len);
-		packet->name[wq->len] = '\0';
+		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;
@@ -153,8 +166,19 @@ static void autofs4_notify_daemon(struct
 		return;
 	}
 
-	if (autofs4_write(sbi->pipe, &pkt, pktsz))
-		autofs4_catatonic_mode(sbi);
+	/* 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,
@@ -170,7 +194,7 @@ static int autofs4_getpath(struct autofs
 	for (tmp = dentry ; tmp != root ; tmp = tmp->d_parent)
 		len += tmp->d_name.len + 1;
 
-	if (--len > NAME_MAX) {
+	if (!len || --len > NAME_MAX) {
 		spin_unlock(&dcache_lock);
 		return 0;
 	}
@@ -190,58 +214,55 @@ static int autofs4_getpath(struct autofs
 }
 
 static struct autofs_wait_queue *
-autofs4_find_wait(struct autofs_sb_info *sbi,
-		  char *name, unsigned int hash, unsigned int len)
+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->hash == hash &&
-		    wq->len == len &&
-		    wq->name && !memcmp(wq->name, name, len))
+		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;
 }
 
-int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry,
-		enum autofs_notify notify)
+/*
+ * 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_info *ino;
 	struct autofs_wait_queue *wq;
-	char *name;
-	unsigned int len = 0;
-	unsigned int hash = 0;
-	int status, type;
-
-	/* In catatonic mode, we don't wait for nobody */
-	if (sbi->catatonic)
-		return -ENOENT;
-	
-	name = kmalloc(NAME_MAX + 1, GFP_KERNEL);
-	if (!name)
-		return -ENOMEM;
+	struct autofs_info *ino;
 
-	/* If this is a direct mount request create a dummy name */
-	if (IS_ROOT(dentry) && (sbi->type & AUTOFS_TYPE_DIRECT))
-		len = sprintf(name, "%p", dentry);
-	else {
-		len = autofs4_getpath(sbi, dentry, &name);
-		if (!len) {
-			kfree(name);
-			return -ENOENT;
-		}
+	/* Wait in progress, continue; */
+	wq = autofs4_find_wait(sbi, qstr);
+	if (wq) {
+		*wait = wq;
+		return 1;
 	}
-	hash = full_name_hash(name, len);
 
-	if (mutex_lock_interruptible(&sbi->wq_mutex)) {
-		kfree(name);
-		return -EINTR;
-	}
+	*wait = NULL;
 
-	wq = autofs4_find_wait(sbi, name, hash, len);
+	/* If we don't yet have any info this is a new request */
 	ino = autofs4_dentry_ino(dentry);
-	if (!wq && ino && notify == NFY_NONE) {
+	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.
@@ -252,13 +273,14 @@ int autofs4_wait(struct autofs_sb_info *
 		while (ino->flags & AUTOFS_INF_EXPIRING) {
 			mutex_unlock(&sbi->wq_mutex);
 			schedule_timeout_interruptible(HZ/10);
-			if (mutex_lock_interruptible(&sbi->wq_mutex)) {
-				kfree(name);
+			if (mutex_lock_interruptible(&sbi->wq_mutex))
 				return -EINTR;
+
+			wq = autofs4_find_wait(sbi, qstr);
+			if (wq) {
+				*wait = wq;
+				return 1;
 			}
-			wq = autofs4_find_wait(sbi, name, hash, len);
-			if (wq)
-				break;
 		}
 
 		/*
@@ -266,18 +288,90 @@ int autofs4_wait(struct autofs_sb_info *
 		 * cases where we wait on NFY_NONE neither depend on the
 		 * return status of the wait.
 		 */
-		if (!wq) {
-			kfree(name);
-			mutex_unlock(&sbi->wq_mutex);
+		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(name);
+			kfree(qstr.name);
 			mutex_unlock(&sbi->wq_mutex);
 			return -ENOMEM;
 		}
@@ -288,9 +382,7 @@ int autofs4_wait(struct autofs_sb_info *
 		wq->next = sbi->queues;
 		sbi->queues = wq;
 		init_waitqueue_head(&wq->queue);
-		wq->hash = hash;
-		wq->name = name;
-		wq->len = len;
+		memcpy(&wq->name, &qstr, sizeof(struct qstr));
 		wq->dev = autofs4_get_dev(sbi);
 		wq->ino = autofs4_get_ino(sbi);
 		wq->uid = current->uid;
@@ -298,7 +390,7 @@ int autofs4_wait(struct autofs_sb_info *
 		wq->pid = current->pid;
 		wq->tgid = current->tgid;
 		wq->status = -EINTR; /* Status return if interrupted */
-		atomic_set(&wq->wait_ctr, 2);
+		wq->wait_ctr = 2;
 		mutex_unlock(&sbi->wq_mutex);
 
 		if (sbi->version < 5) {
@@ -308,38 +400,35 @@ int autofs4_wait(struct autofs_sb_info *
 				type = autofs_ptype_expire_multi;
 		} else {
 			if (notify == NFY_MOUNT)
-				type = (sbi->type & AUTOFS_TYPE_DIRECT) ?
+				type = autofs_type_trigger(sbi->type) ?
 					autofs_ptype_missing_direct :
 					 autofs_ptype_missing_indirect;
 			else
-				type = (sbi->type & AUTOFS_TYPE_DIRECT) ?
+				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->len, wq->name, notify);
+			(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 {
-		atomic_inc(&wq->wait_ctr);
+		wq->wait_ctr++;
 		mutex_unlock(&sbi->wq_mutex);
-		kfree(name);
+		kfree(qstr.name);
 		DPRINTK("existing wait id = 0x%08lx, name = %.*s, nfy=%d",
-			(unsigned long) wq->wait_queue_token, wq->len, wq->name, notify);
+			(unsigned long) wq->wait_queue_token, wq->name.len,
+			wq->name.name, notify);
 	}
 
-	/* wq->name is NULL if and only if the lock is already released */
-
-	if (sbi->catatonic) {
-		/* We might have slept, so check again for catatonic mode */
-		wq->status = -ENOENT;
-		kfree(wq->name);
-		wq->name = NULL;
-	}
-
-	if (wq->name) {
+	/*
+	 * 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;
@@ -350,7 +439,7 @@ int autofs4_wait(struct autofs_sb_info *
 		recalc_sigpending();
 		spin_unlock_irqrestore(&current->sighand->siglock, irqflags);
 
-		wait_event_interruptible(wq->queue, wq->name == NULL);
+		wait_event_interruptible(wq->queue, wq->name.name == NULL);
 
 		spin_lock_irqsave(&current->sighand->siglock, irqflags);
 		current->blocked = oldset;
@@ -362,9 +451,45 @@ int autofs4_wait(struct autofs_sb_info *
 
 	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? */
-	if (atomic_dec_and_test(&wq->wait_ctr))
+	mutex_lock(&sbi->wq_mutex);
+	if (!--wq->wait_ctr)
 		kfree(wq);
+	mutex_unlock(&sbi->wq_mutex);
 
 	return status;
 }
@@ -386,16 +511,13 @@ int autofs4_wait_release(struct autofs_s
 	}
 
 	*wql = wq->next;	/* Unlink from chain */
-	mutex_unlock(&sbi->wq_mutex);
-	kfree(wq->name);
-	wq->name = NULL;	/* Do not wait on this queue */
-
+	kfree(wq->name.name);
+	wq->name.name = NULL;	/* Do not wait on this queue */
 	wq->status = status;
-
-	if (atomic_dec_and_test(&wq->wait_ctr))	/* Is anyone still waiting for this guy? */
+	wake_up_interruptible(&wq->queue);
+	if (!--wq->wait_ctr)
 		kfree(wq);
-	else
-		wake_up_interruptible(&wq->queue);
+	mutex_unlock(&sbi->wq_mutex);
 
 	return 0;
 }
--- linux-2.6.18.orig/fs/autofs/waitq.c
+++ linux-2.6.18/fs/autofs/waitq.c
@@ -41,6 +41,7 @@ void autofs_catatonic_mode(struct autofs
 		wq = nwq;
 	}
 	fput(sbi->pipe);	/* Close the pipe */
+	sbi->pipe = NULL;
 	autofs_hash_dputall(&sbi->dirhash); /* Remove all dentry pointers */
 }
 
--- linux-2.6.18.orig/include/linux/auto_fs4.h
+++ linux-2.6.18/include/linux/auto_fs4.h
@@ -23,12 +23,71 @@
 #define AUTOFS_MIN_PROTO_VERSION	3
 #define AUTOFS_MAX_PROTO_VERSION	5
 
-#define AUTOFS_PROTO_SUBVERSION		0
+#define AUTOFS_PROTO_SUBVERSION		1
 
 /* Mask for expire behaviour */
 #define AUTOFS_EXP_IMMEDIATE		1
 #define AUTOFS_EXP_LEAVES		2
 
+#define AUTOFS_TYPE_ANY			0U
+#define AUTOFS_TYPE_INDIRECT		1U
+#define AUTOFS_TYPE_DIRECT		2U
+#define AUTOFS_TYPE_OFFSET		4U
+
+static inline void set_autofs_type_indirect(unsigned int *type)
+{
+	*type = AUTOFS_TYPE_INDIRECT;
+	return;
+}
+
+static inline unsigned int autofs_type_indirect(unsigned int type)
+{
+	return (type == AUTOFS_TYPE_INDIRECT);
+}
+
+static inline void set_autofs_type_direct(unsigned int *type)
+{
+	*type = AUTOFS_TYPE_DIRECT;
+	return;
+}
+
+static inline unsigned int autofs_type_direct(unsigned int type)
+{
+	return (type == AUTOFS_TYPE_DIRECT);
+}
+
+static inline void set_autofs_type_offset(unsigned int *type)
+{
+	*type = AUTOFS_TYPE_OFFSET;
+	return;
+}
+
+static inline unsigned int autofs_type_offset(unsigned int type)
+{
+	return (type == AUTOFS_TYPE_OFFSET);
+}
+
+static inline unsigned int autofs_type_trigger(unsigned int type)
+{
+	return (type == AUTOFS_TYPE_DIRECT || type == AUTOFS_TYPE_OFFSET);
+}
+
+/*
+ * This isn't really a type as we use it to say "no type set" to
+ * indicate we want to search for "any" mount in the
+ * autofs_dev_ioctl_ismountpoint() device ioctl function.
+ */
+static inline void set_autofs_type_any(unsigned int *type)
+{
+	*type = AUTOFS_TYPE_ANY;
+	return;
+}
+
+static inline unsigned int autofs_type_any(unsigned int type)
+{
+	return (type == AUTOFS_TYPE_ANY);
+}
+
 /* Daemon notification packet types */
 enum autofs_notify {
 	NFY_NONE,
@@ -59,6 +118,13 @@ struct autofs_packet_expire_multi {
 	char name[NAME_MAX+1];
 };
 
+union autofs_packet_union {
+	struct autofs_packet_hdr hdr;
+	struct autofs_packet_missing missing;
+	struct autofs_packet_expire expire;
+	struct autofs_packet_expire_multi expire_multi;
+};
+
 /* autofs v5 common packet struct */
 struct autofs_v5_packet {
 	struct autofs_packet_hdr hdr;
@@ -78,20 +144,19 @@ typedef struct autofs_v5_packet autofs_p
 typedef struct autofs_v5_packet autofs_packet_missing_direct_t;
 typedef struct autofs_v5_packet autofs_packet_expire_direct_t;
 
-union autofs_packet_union {
+union autofs_v5_packet_union {
 	struct autofs_packet_hdr hdr;
-	struct autofs_packet_missing missing;
-	struct autofs_packet_expire expire;
-	struct autofs_packet_expire_multi expire_multi;
 	struct autofs_v5_packet v5_packet;
+	autofs_packet_missing_indirect_t missing_indirect;
+	autofs_packet_expire_indirect_t expire_indirect;
+	autofs_packet_missing_direct_t missing_direct;
+	autofs_packet_expire_direct_t expire_direct;
 };
 
 #define AUTOFS_IOC_EXPIRE_MULTI		_IOW(0x93,0x66,int)
 #define AUTOFS_IOC_EXPIRE_INDIRECT	AUTOFS_IOC_EXPIRE_MULTI
 #define AUTOFS_IOC_EXPIRE_DIRECT	AUTOFS_IOC_EXPIRE_MULTI
 #define AUTOFS_IOC_PROTOSUBVER		_IOR(0x93,0x67,int)
-#define AUTOFS_IOC_ASKREGHOST           _IOR(0x93,0x68,int)
-#define AUTOFS_IOC_TOGGLEREGHOST        _IOR(0x93,0x69,int)
 #define AUTOFS_IOC_ASKUMOUNT		_IOR(0x93,0x70,int)
 
 
--- linux-2.6.18.orig/fs/autofs4/expire.c
+++ linux-2.6.18/fs/autofs4/expire.c
@@ -56,12 +56,25 @@ static int autofs4_mount_busy(struct vfs
 	mntget(mnt);
 	dget(dentry);
 
-	if (!autofs4_follow_mount(&mnt, &dentry))
+	if (!follow_down(&mnt, &dentry))
 		goto done;
 
-	/* This is an autofs submount, we can't expire it */
-	if (is_autofs4_dentry(dentry))
-		goto done;
+	if (is_autofs4_dentry(dentry)) {
+		struct autofs_sb_info *sbi = autofs4_sbi(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(dentry)) {
+			status = 0;
+			goto done;
+		}
+	}
 
 	/* Update the expiry counter if fs is busy */
 	if (!may_umount_tree(mnt)) {
@@ -73,8 +86,8 @@ static int autofs4_mount_busy(struct vfs
 	status = 0;
 done:
 	DPRINTK("returning = %d", status);
-	mntput(mnt);
 	dput(dentry);
+	mntput(mnt);
 	return status;
 }
 
@@ -244,10 +257,10 @@ cont:
 }
 
 /* Check if we can expire a direct mount (possibly a tree) */
-static struct dentry *autofs4_expire_direct(struct super_block *sb,
-					    struct vfsmount *mnt,
-					    struct autofs_sb_info *sbi,
-					    int how)
+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);
@@ -259,13 +272,15 @@ static struct dentry *autofs4_expire_dir
 	now = jiffies;
 	timeout = sbi->exp_timeout;
 
-	/* Lock the tree as we must expire as a whole */
 	spin_lock(&sbi->fs_lock);
 	if (!autofs4_direct_busy(mnt, root, timeout, do_now)) {
 		struct autofs_info *ino = autofs4_dentry_ino(root);
-
-		/* Set this flag early to catch sys_chdir and the like */
+		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;
 	}
@@ -281,10 +296,10 @@ static struct dentry *autofs4_expire_dir
  *  - it is unused by any user process
  *  - it has been unused for exp_timeout time
  */
-static struct dentry *autofs4_expire_indirect(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)
 {
 	unsigned long timeout;
 	struct dentry *root = sb->s_root;
@@ -292,6 +307,8 @@ static struct dentry *autofs4_expire_ind
 	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 ( !sbi->exp_timeout || !root )
 		return NULL;
@@ -316,6 +333,9 @@ static struct dentry *autofs4_expire_ind
 		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).
@@ -326,6 +346,11 @@ static struct dentry *autofs4_expire_ind
 			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;
@@ -333,7 +358,7 @@ static struct dentry *autofs4_expire_ind
 			/* Can we expire this guy */
 			if (autofs4_can_expire(dentry, timeout, do_now)) {
 				expired = dentry;
-				break;
+				goto found;
 			}
 			goto next;
 		}
@@ -343,46 +368,80 @@ static struct dentry *autofs4_expire_ind
 
 		/* Case 2: tree mount, expire iff entire tree is not busy */
 		if (!exp_leaves) {
-			/* Lock the tree as we must expire as a whole */
-			spin_lock(&sbi->fs_lock);
-			if (!autofs4_tree_busy(mnt, dentry, timeout, do_now)) {
-				struct autofs_info *inf = autofs4_dentry_ino(dentry);
+			/* Path walk currently on this dentry? */
+			ino_count = atomic_read(&ino->count) + 1;
+			if (atomic_read(&dentry->d_count) > ino_count)
+				goto next;
 
-				/* Set this flag early to catch sys_chdir and the like */
-				inf->flags |= AUTOFS_INF_EXPIRING;
-				spin_unlock(&sbi->fs_lock);
+			if (!autofs4_tree_busy(mnt, dentry, timeout, do_now)) {
 				expired = dentry;
-				break;
+				goto found;
 			}
-			spin_unlock(&sbi->fs_lock);
 		/*
 		 * 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);
-				break;
+				goto found;
 			}
 		}
 next:
+		spin_unlock(&sbi->fs_lock);
 		dput(dentry);
 		spin_lock(&dcache_lock);
 		next = next->next;
 	}
+	spin_unlock(&dcache_lock);
+	return NULL;
 
-	if (expired) {
-		DPRINTK("returning %p %.*s",
-			expired, (int)expired->d_name.len, expired->d_name.name);
-		spin_lock(&dcache_lock);
-		list_move(&expired->d_parent->d_subdirs, &expired->d_u.d_child);
-		spin_unlock(&dcache_lock);
-		return expired;
-	}
+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;
+}
 
-	return NULL;
+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 */
@@ -392,7 +451,9 @@ int autofs4_expire_run(struct super_bloc
 		      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);
 
@@ -408,9 +469,15 @@ int autofs4_expire_run(struct super_bloc
 	dput(dentry);
 
 	if ( copy_to_user(pkt_p, &pkt, sizeof(struct autofs_packet_expire)) )
-		return -EFAULT;
+		ret = -EFAULT;
 
-	return 0;
+	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;
 }
 
 /* Call repeatedly until it returns -EAGAIN, meaning there's nothing
@@ -425,7 +492,7 @@ int autofs4_expire_multi(struct super_bl
 	if (arg && get_user(do_now, arg))
 		return -EFAULT;
 
-	if (sbi->type & AUTOFS_TYPE_DIRECT)
+	if (autofs_type_trigger(sbi->type))
 		dentry = autofs4_expire_direct(sb, mnt, sbi, do_now);
 	else
 		dentry = autofs4_expire_indirect(sb, mnt, sbi, do_now);
@@ -435,9 +502,16 @@ int autofs4_expire_multi(struct super_bl
 
 		/* This is synchronous because it makes the daemon a
                    little easier */
-		ino->flags |= AUTOFS_INF_EXPIRING;
 		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);
 	}
 
--- linux-2.6.18.orig/include/linux/compat_ioctl.h
+++ linux-2.6.18/include/linux/compat_ioctl.h
@@ -565,8 +565,6 @@ COMPATIBLE_IOCTL(AUTOFS_IOC_PROTOVER)
 COMPATIBLE_IOCTL(AUTOFS_IOC_EXPIRE)
 COMPATIBLE_IOCTL(AUTOFS_IOC_EXPIRE_MULTI)
 COMPATIBLE_IOCTL(AUTOFS_IOC_PROTOSUBVER)
-COMPATIBLE_IOCTL(AUTOFS_IOC_ASKREGHOST)
-COMPATIBLE_IOCTL(AUTOFS_IOC_TOGGLEREGHOST)
 COMPATIBLE_IOCTL(AUTOFS_IOC_ASKUMOUNT)
 /* Raw devices */
 COMPATIBLE_IOCTL(RAW_SETBIND)
--- /dev/null
+++ linux-2.6.18/Documentation/filesystems/autofs4-mount-control.txt
@@ -0,0 +1,414 @@
+
+Miscellaneous Device control operations for the autofs4 kernel module
+====================================================================
+
+The problem
+===========
+
+There is a problem with active restarts in autofs (that is to say
+restarting autofs when there are busy mounts).
+
+During normal operation autofs uses a file descriptor opened on the
+directory that is being managed in order to be able to issue control
+operations. Using a file descriptor gives ioctl operations access to
+autofs specific information stored in the super block. The operations
+are things such as setting an autofs mount catatonic, setting the
+expire timeout and requesting expire checks. As is explained below,
+certain types of autofs triggered mounts can end up covering an autofs
+mount itself which prevents us being able to use open(2) to obtain a
+file descriptor for these operations if we don't already have one open.
+
+Currently autofs uses "umount -l" (lazy umount) to clear active mounts
+at restart. While using lazy umount works for most cases, anything that
+needs to walk back up the mount tree to construct a path, such as
+getcwd(2) and the proc file system /proc/<pid>/cwd, no longer works
+because the point from which the path is constructed has been detached
+from the mount tree.
+
+The actual problem with autofs is that it can't reconnect to existing
+mounts. Immediately one thinks of just adding the ability to remount
+autofs file systems would solve it, but alas, that can't work. This is
+because autofs direct mounts and the implementation of "on demand mount
+and expire" of nested mount trees have the file system mounted directly
+on top of the mount trigger directory dentry.
+
+For example, there are two types of automount maps, direct (in the kernel
+module source you will see a third type called an offset, which is just
+a direct mount in disguise) and indirect.
+
+Here is a master map with direct and indirect map entries:
+
+/-      /etc/auto.direct
+/test   /etc/auto.indirect
+
+and the corresponding map files:
+
+/etc/auto.direct:
+
+/automount/dparse/g6  budgie:/autofs/export1
+/automount/dparse/g1  shark:/autofs/export1
+and so on.
+
+/etc/auto.indirect:
+
+g1    shark:/autofs/export1
+g6    budgie:/autofs/export1
+and so on.
+
+For the above indirect map an autofs file system is mounted on /test and
+mounts are triggered for each sub-directory key by the inode lookup
+operation. So we see a mount of shark:/autofs/export1 on /test/g1, for
+example.
+
+The way that direct mounts are handled is by making an autofs mount on
+each full path, such as /automount/dparse/g1, and using it as a mount
+trigger. So when we walk on the path we mount shark:/autofs/export1 "on
+top of this mount point". Since these are always directories we can
+use the follow_link inode operation to trigger the mount.
+
+But, each entry in direct and indirect maps can have offsets (making
+them multi-mount map entries).
+
+For example, an indirect mount map entry could also be:
+
+g1  \
+   /        shark:/autofs/export5/testing/test \
+   /s1      shark:/autofs/export/testing/test/s1 \
+   /s2      shark:/autofs/export5/testing/test/s2 \
+   /s1/ss1  shark:/autofs/export1 \
+   /s2/ss2  shark:/autofs/export2
+
+and a similarly a direct mount map entry could also be:
+
+/automount/dparse/g1 \
+    /       shark:/autofs/export5/testing/test \
+    /s1     shark:/autofs/export/testing/test/s1 \
+    /s2     shark:/autofs/export5/testing/test/s2 \
+    /s1/ss1 shark:/autofs/export2 \
+    /s2/ss2 shark:/autofs/export2
+
+One of the issues with version 4 of autofs was that, when mounting an
+entry with a large number of offsets, possibly with nesting, we needed
+to mount and umount all of the offsets as a single unit. Not really a
+problem, except for people with a large number of offsets in map entries.
+This mechanism is used for the well known "hosts" map and we have seen
+cases (in 2.4) where the available number of mounts are exhausted or
+where the number of privileged ports available is exhausted.
+
+In version 5 we mount only as we go down the tree of offsets and
+similarly for expiring them which resolves the above problem. There is
+somewhat more detail to the implementation but it isn't needed for the
+sake of the problem explanation. The one important detail is that these
+offsets are implemented using the same mechanism as the direct mounts
+above and so the mount points can be covered by a mount.
+
+The current autofs implementation uses an ioctl file descriptor opened
+on the mount point for control operations. The references held by the
+descriptor are accounted for in checks made to determine if a mount is
+in use and is also used to access autofs file system information held
+in the mount super block. So the use of a file handle needs to be
+retained.
+
+
+The Solution
+============
+
+To be able to restart autofs leaving existing direct, indirect and
+offset mounts in place we need to be able to obtain a file handle
+for these potentially covered autofs mount points. Rather than just
+implement an isolated operation it was decided to re-implement the
+existing ioctl interface and add new operations to provide this
+functionality.
+
+In addition, to be able to reconstruct a mount tree that has busy mounts,
+the uid and gid of the last user that triggered the mount needs to be
+available because these can be used as macro substitution variables in
+autofs maps. They are recorded at mount request time and an operation
+has been added to retrieve them.
+
+Since we're re-implementing the control interface, a couple of other
+problems with the existing interface have been addressed. First, when
+a mount or expire operation completes a status is returned to the
+kernel by either a "send ready" or a "send fail" operation. The
+"send fail" operation of the ioctl interface could only ever send
+ENOENT so the re-implementation allows user space to send an actual
+status. Another expensive operation in user space, for those using
+very large maps, is discovering if a mount is present. Usually this
+involves scanning /proc/mounts and since it needs to be done quite
+often it can introduce significant overhead when there are many entries
+in the mount table. An operation to lookup the mount status of a mount
+point dentry (covered or not) has also been added.
+
+Current kernel development policy recommends avoiding the use of the
+ioctl mechanism in favor of systems such as Netlink. An implementation
+using this system was attempted to evaluate its suitability and it was
+found to be inadequate, in this case. The Generic Netlink system was
+used for this as raw Netlink would lead to a significant increase in
+complexity. There's no question that the Generic Netlink system is an
+elegant solution for common case ioctl functions but it's not a complete
+replacement probably because it's primary purpose in life is to be a
+message bus implementation rather than specifically an ioctl replacement.
+While it would be possible to work around this there is one concern
+that lead to the decision to not use it. This is that the autofs
+expire in the daemon has become far to complex because umount
+candidates are enumerated, almost for no other reason than to "count"
+the number of times to call the expire ioctl. This involves scanning
+the mount table which has proved to be a big overhead for users with
+large maps. The best way to improve this is try and get back to the
+way the expire was done long ago. That is, when an expire request is
+issued for a mount (file handle) we should continually call back to
+the daemon until we can't umount any more mounts, then return the
+appropriate status to the daemon. At the moment we just expire one
+mount at a time. A Generic Netlink implementation would exclude this
+possibility for future development due to the requirements of the
+message bus architecture.
+
+
+autofs4 Miscellaneous Device mount control interface
+====================================================
+
+The control interface is opening a device node, typically /dev/autofs.
+
+All the ioctls use a common structure to pass the needed parameter
+information and return operation results:
+
+struct autofs_dev_ioctl {
+	__u32 ver_major;
+	__u32 ver_minor;
+	__u32 size;             /* total size of data passed in
+				 * including this struct */
+	__s32 ioctlfd;          /* automount command fd */
+
+	/* Command parameters */
+
+	union {
+		struct args_protover            protover;
+		struct args_protosubver         protosubver;
+		struct args_openmount           openmount;
+		struct args_ready               ready;
+		struct args_fail                fail;
+		struct args_setpipefd           setpipefd;
+		struct args_timeout             timeout;
+		struct args_requester           requester;
+		struct args_expire              expire;
+		struct args_askumount           askumount;
+		struct args_ismountpoint        ismountpoint;
+	};
+
+	char path[0];
+};
+
+The ioctlfd field is a mount point file descriptor of an autofs mount
+point. It is returned by the open call and is used by all calls except
+the check for whether a given path is a mount point, where it may
+optionally be used to check a specific mount corresponding to a given
+mount point file descriptor, and when requesting the uid and gid of the
+last successful mount on a directory within the autofs file system.
+
+The anonymous union is used to communicate parameters and results of calls
+made as described below.
+
+The path field is used to pass a path where it is needed and the size field
+is used account for the increased structure length when translating the
+structure sent from user space.
+
+This structure can be initialized before setting specific fields by using
+the void function call init_autofs_dev_ioctl(struct autofs_dev_ioctl *).
+
+All of the ioctls perform a copy of this structure from user space to
+kernel space and return -EINVAL if the size parameter is smaller than
+the structure size itself, -ENOMEM if the kernel memory allocation fails
+or -EFAULT if the copy itself fails. Other checks include a version check
+of the compiled in user space version against the module version and a
+mismatch results in a -EINVAL return. If the size field is greater than
+the structure size then a path is assumed to be present and is checked to
+ensure it begins with a "/" and is NULL terminated, otherwise -EINVAL is
+returned. Following these checks, for all ioctl commands except
+AUTOFS_DEV_IOCTL_VERSION_CMD, AUTOFS_DEV_IOCTL_OPENMOUNT_CMD and
+AUTOFS_DEV_IOCTL_CLOSEMOUNT_CMD the ioctlfd is validated and if it is
+not a valid descriptor or doesn't correspond to an autofs mount point
+an error of -EBADF, -ENOTTY or -EINVAL (not an autofs descriptor) is
+returned.
+
+
+The ioctls
+==========
+
+An example of an implementation which uses this interface can be seen
+in autofs version 5.0.4 and later in file lib/dev-ioctl-lib.c of the
+distribution tar available for download from kernel.org in directory
+/pub/linux/daemons/autofs/v5.
+
+The device node ioctl operations implemented by this interface are:
+
+
+AUTOFS_DEV_IOCTL_VERSION
+------------------------
+
+Get the major and minor version of the autofs4 device ioctl kernel module
+implementation. It requires an initialized struct autofs_dev_ioctl as an
+input parameter and sets the version information in the passed in structure.
+It returns 0 on success or the error -EINVAL if a version mismatch is
+detected.
+
+
+AUTOFS_DEV_IOCTL_PROTOVER_CMD and AUTOFS_DEV_IOCTL_PROTOSUBVER_CMD
+------------------------------------------------------------------
+
+Get the major and minor version of the autofs4 protocol version understood
+by loaded module. This call requires an initialized struct autofs_dev_ioctl
+with the ioctlfd field set to a valid autofs mount point descriptor
+and sets the requested version number in structure field protover.version
+and ptotosubver.sub_version respectively. These commands return 0 on
+success or one of the negative error codes if validation fails.
+
+
+AUTOFS_DEV_IOCTL_OPENMOUNT_CMD and AUTOFS_DEV_IOCTL_CLOSEMOUNT_CMD
+------------------------------------------------------------------
+
+Obtain and release a file descriptor for an autofs managed mount point
+path. The open call requires an initialized struct autofs_dev_ioctl with
+the the path field set and the size field adjusted appropriately as well
+as the openmount.devid field set to the device number of the autofs mount.
+The device number of an autofs mounted filesystem can be obtained by using
+the AUTOFS_DEV_IOCTL_ISMOUNTPOINT ioctl function by providing the path
+and autofs mount type, as described below. The close call requires an
+initialized struct autofs_dev_ioct with the ioctlfd field set to the
+descriptor obtained from the open call. The release of the file descriptor
+can also be done with close(2) so any open descriptors will also be
+closed at process exit. The close call is included in the implemented
+operations largely for completeness and to provide for a consistent
+user space implementation.
+
+
+AUTOFS_DEV_IOCTL_READY_CMD and AUTOFS_DEV_IOCTL_FAIL_CMD
+--------------------------------------------------------
+
+Return mount and expire result status from user space to the kernel.
+Both of these calls require an initialized struct autofs_dev_ioctl
+with the ioctlfd field set to the descriptor obtained from the open
+call and the ready.token or fail.token field set to the wait queue
+token number, received by user space in the foregoing mount or expire
+request. The fail.status field is set to the status to be returned when
+sending a failure notification with AUTOFS_DEV_IOCTL_FAIL_CMD.
+
+
+AUTOFS_DEV_IOCTL_SETPIPEFD_CMD
+------------------------------
+
+Set the pipe file descriptor used for kernel communication to the daemon.
+Normally this is set at mount time using an option but when reconnecting
+to a existing mount we need to use this to tell the autofs mount about
+the new kernel pipe descriptor. In order to protect mounts against
+incorrectly setting the pipe descriptor we also require that the autofs
+mount be catatonic (see next call).
+
+The call requires an initialized struct autofs_dev_ioctl with the
+ioctlfd field set to the descriptor obtained from the open call and
+the setpipefd.pipefd field set to descriptor of the pipe. On success
+the call also sets the process group id used to identify the controlling
+process (eg. the owning automount(8) daemon) to the process group of
+the caller.
+
+
+AUTOFS_DEV_IOCTL_CATATONIC_CMD
+------------------------------
+
+Make the autofs mount point catatonic. The autofs mount will no longer
+issue mount requests, the kernel communication pipe descriptor is released
+and any remaining waits in the queue released.
+
+The call requires an initialized struct autofs_dev_ioctl with the
+ioctlfd field set to the descriptor obtained from the open call.
+
+
+AUTOFS_DEV_IOCTL_TIMEOUT_CMD
+----------------------------
+
+Set the expire timeout for mounts withing an autofs mount point.
+
+The call requires an initialized struct autofs_dev_ioctl with the
+ioctlfd field set to the descriptor obtained from the open call.
+The timeout.timeout field is set to the desired timeout and this
+field is set to the value of the value of the current timeout of
+the mount upon successful completion.
+
+
+AUTOFS_DEV_IOCTL_REQUESTER_CMD
+------------------------------
+
+Return the uid and gid of the last process to successfully trigger a the
+mount on the given path dentry.
+
+The call requires an initialized struct autofs_dev_ioctl with the path
+field set to the mount point in question and the size field adjusted
+appropriately as well as the ioctlfd field set to the descriptor obtained
+from the open call. Upon return the struct fields requester.uid and
+requester.gid contain the uid and gid respectively.
+
+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.
+This call provides the ability to obtain this uid and gid so they may be
+used by user space for the mount map lookups.
+
+
+AUTOFS_DEV_IOCTL_EXPIRE_CMD
+---------------------------
+
+Issue an expire request to the kernel for an autofs mount. Typically
+this ioctl is called until no further expire candidates are found.
+
+The call requires an initialized struct autofs_dev_ioctl with the
+ioctlfd field set to the descriptor obtained from the open call. In
+addition an immediate expire, independent of the mount timeout, can be
+requested by setting the expire.how field to 1. If no expire candidates
+can be found the ioctl returns -1 with errno set to EAGAIN.
+
+This call causes the kernel module to check the mount corresponding
+to the given ioctlfd for mounts that can be expired, issues an expire
+request back to the daemon and waits for completion.
+
+AUTOFS_DEV_IOCTL_ASKUMOUNT_CMD
+------------------------------
+
+Checks if an autofs mount point is in use.
+
+The call requires an initialized struct autofs_dev_ioctl with the
+ioctlfd field set to the descriptor obtained from the open call and
+it returns the result in the askumount.may_umount field, 1 for busy
+and 0 otherwise.
+
+
+AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD
+---------------------------------
+
+Check if the given path is a mountpoint.
+
+The call requires an initialized struct autofs_dev_ioctl. There are two
+possible variations. Both use the path field set to the path of the mount
+point to check and the size field must be adjusted appropriately. One uses
+the ioctlfd field to identify a specific mount point to check while the
+other variation uses the path and optionaly the ismountpoint.in.type
+field set to an autofs mount type. The call returns 1 if this is a mount
+point and sets the ismountpoint.out.devid field to the device number of
+the mount and the ismountpoint.out.magic field to the relevant super
+block magic number (described below) or 0 if it isn't a mountpoint. In
+both cases the the device number (as returned by new_encode_dev()) is
+returned in the ismountpoint.out.devid field.
+
+If supplied with a file descriptor we're looking for a specific mount,
+not necessarily at the top of the mounted stack. In this case the path
+the descriptor corresponds to 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 descriptor corresponds to a mount
+point and and also returns the super magic of the covering mount if there
+is one or 0 if it isn't a mountpoint.
+
+If a path is supplied (and the ioctlfd field is set to -1) then the path
+is looked up and is checked to see if it is the root of a mount. If a
+type is also given we are looking for a particular autofs mount and if
+a match isn't found a fail is returned. If the the located path is the
+root of a mount 1 is returned along with the super magic of the mount
+or 0 otherwise.
+ 
--- linux-2.6.18.orig/fs/autofs4/Makefile
+++ linux-2.6.18/fs/autofs4/Makefile
@@ -4,4 +4,4 @@
 
 obj-$(CONFIG_AUTOFS4_FS) += autofs4.o
 
-autofs4-objs := init.o inode.o root.o symlink.o waitq.o expire.o
+autofs4-objs := init.o inode.o root.o symlink.o waitq.o expire.o dev-ioctl.o
--- /dev/null
+++ linux-2.6.18/fs/autofs4/dev-ioctl.c
@@ -0,0 +1,867 @@
+/*
+ * 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/sched.h>
+#include <linux/compat.h>
+#include <linux/syscalls.h>
+#include <linux/smp_lock.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, void *end)
+{
+	while ((void *) str <= end)
+		if (!*str++)
+			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;
+
+	if ((err = check_dev_ioctl_version(cmd, param))) {
+		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,
+				 (void *) ((size_t) param + param->size));
+		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_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;
+}
+
+/*
+ * Walk down the mount stack looking for an autofs mount that
+ * has the requested device number (aka. new_encode_dev(sb->s_dev).
+ */
+static int autofs_dev_ioctl_find_super(struct nameidata *nd, dev_t devno)
+{
+	struct dentry *dentry;
+	struct inode *inode;
+	struct super_block *sb;
+	dev_t s_dev;
+	unsigned int err;
+
+	err = -ENOENT;
+
+	/* Lookup the dentry name at the base of our mount point */
+	dentry = d_lookup(nd->dentry, &nd->last);
+	if (!dentry)
+		goto out;
+
+	dput(nd->dentry);
+	nd->dentry = dentry;
+
+	/* And follow the mount stack looking for our autofs mount */
+	while (follow_down(&nd->mnt, &nd->dentry)) {
+		inode = nd->dentry->d_inode;
+		if (!inode)
+			break;
+
+		sb = inode->i_sb;
+		s_dev = new_encode_dev(sb->s_dev);
+		if (devno == s_dev) {
+			if (sb->s_magic == AUTOFS_SUPER_MAGIC) {
+				err = 0;
+				break;
+			}
+		}
+	}
+out:
+	return err;
+}
+
+/*
+ * Walk down the mount stack looking for an autofs mount that
+ * has the requested mount type (ie. indirect, direct or offset).
+ */
+static int autofs_dev_ioctl_find_sbi_type(struct nameidata *nd, unsigned int type)
+{
+	struct dentry *dentry;
+	struct autofs_info *ino;
+	unsigned int err;
+
+	err = -ENOENT;
+
+	/* Lookup the dentry name at the base of our mount point */
+	dentry = d_lookup(nd->dentry, &nd->last);
+	if (!dentry)
+		goto out;
+
+	dput(nd->dentry);
+	nd->dentry = dentry;
+
+	/* And follow the mount stack looking for our autofs mount */
+	while (follow_down(&nd->mnt, &nd->dentry)) {
+		ino = autofs4_dentry_ino(nd->dentry);
+		if (ino && ino->sbi->type & type) {
+			err = 0;
+			break;
+		}
+	}
+out:
+	return err;
+}
+
+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 *path, dev_t devid)
+{
+	struct file *filp;
+	struct nameidata nd;
+	int err, fd;
+
+	fd = get_unused_fd();
+	if (likely(fd >= 0)) {
+		/* Get nameidata of the parent directory */
+		err = path_lookup(path, LOOKUP_PARENT, &nd);
+		if (err)
+			goto out;
+
+		/*
+		 * Search down, within the parent, looking for an
+		 * autofs super block that has the device number
+		 * corresponding to the autofs fs we want to open.
+		 */
+		err = autofs_dev_ioctl_find_super(&nd, devid);
+		if (err) {
+			path_release(&nd);
+			goto out;
+		}
+
+		filp = dentry_open(nd.dentry, nd.mnt, O_RDONLY);
+		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 = 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 = process_group(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 nameidata nd;
+	const char *path;
+	dev_t devid;
+	int err = -ENOENT;
+
+	if (param->size <= sizeof(*param)) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	path = param->path;
+	devid = sbi->sb->s_dev;
+
+	param->requester.uid = param->requester.gid = -1;
+
+	/* Get nameidata of the parent directory */
+	err = path_lookup(path, LOOKUP_PARENT, &nd);
+	if (err)
+		goto out;
+
+	err = autofs_dev_ioctl_find_super(&nd, devid);
+	if (err)
+		goto out_release;
+
+	ino = autofs4_dentry_ino(nd.dentry);
+	if (ino) {
+		err = 0;
+		autofs4_expire_wait(nd.dentry);
+		spin_lock(&sbi->fs_lock);
+		param->requester.uid = ino->uid;
+		param->requester.gid = ino->gid;
+		spin_unlock(&sbi->fs_lock);
+	}
+
+out_release:
+	path_release(&nd);
+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 dentry *dentry;
+	struct vfsmount *mnt;
+	int err = -EAGAIN;
+	int how;
+
+	how = param->expire.how;
+	mnt = fp->f_vfsmnt;
+
+	if (autofs_type_trigger(sbi->type))
+		dentry = autofs4_expire_direct(sbi->sb, mnt, sbi, how);
+	else
+		dentry = autofs4_expire_indirect(sbi->sb, mnt, sbi, how);
+
+	if (dentry) {
+		struct autofs_info *ino = autofs4_dentry_ino(dentry);
+
+		/*
+		 * This is synchronous because it makes the daemon a
+		 * little easier
+		*/
+		err = autofs4_wait(sbi, dentry, NFY_EXPIRE);
+
+		spin_lock(&sbi->fs_lock);
+		if (ino->flags & AUTOFS_INF_MOUNTPOINT) {
+			ino->flags &= ~AUTOFS_INF_MOUNTPOINT;
+			sbi->sb->s_root->d_mounted++;
+		}
+		ino->flags &= ~AUTOFS_INF_EXPIRING;
+		complete_all(&ino->expire_complete);
+		spin_unlock(&sbi->fs_lock);
+		dput(dentry);
+	}
+
+	return err;
+}
+
+/* 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_vfsmnt))
+		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 nameidata nd;
+	const char *path;
+	unsigned int type;
+	unsigned int devid, magic;
+	int err = -ENOENT;
+
+	if (param->size <= sizeof(*param)) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	path = 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)) {
+			struct super_block *sb;
+
+			err = path_lookup(path, LOOKUP_FOLLOW, &nd);
+			if (err)
+				goto out;
+
+			sb = nd.dentry->d_sb;
+			devid = new_encode_dev(sb->s_dev);
+		} else {
+			struct autofs_info *ino;
+
+			err = path_lookup(path, LOOKUP_PARENT, &nd);
+			if (err)
+				goto out;
+
+			err = autofs_dev_ioctl_find_sbi_type(&nd, type);
+			if (err)
+				goto out_release;
+
+			ino = autofs4_dentry_ino(nd.dentry);
+			devid = autofs4_get_dev(ino->sbi);
+		}
+
+		err = 0;
+		if (nd.dentry->d_inode &&
+		    nd.mnt->mnt_root == nd.dentry) {
+			err = 1;
+			magic = nd.dentry->d_inode->i_sb->s_magic;
+		}
+	} else {
+		dev_t devid = new_encode_dev(sbi->sb->s_dev);
+
+		err = path_lookup(path, LOOKUP_PARENT, &nd);
+		if (err)
+			goto out;
+
+		err = autofs_dev_ioctl_find_super(&nd, devid);
+		if (err)
+			goto out_release;
+
+		devid = autofs4_get_dev(sbi);
+
+		err = have_submounts(nd.dentry);
+
+		if (nd.mnt->mnt_mountpoint != nd.mnt->mnt_root) {
+			if (follow_down(&nd.mnt, &nd.dentry)) {
+				struct inode *inode = nd.dentry->d_inode;
+				magic = inode->i_sb->s_magic;
+			}
+		}
+	}
+
+	param->ismountpoint.out.devid = devid;
+	param->ismountpoint.out.magic = magic;
+
+out_release:
+	path_release(&nd);
+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;
+}
+
--- /dev/null
+++ linux-2.6.18/include/linux/auto_dev-ioctl.h
@@ -0,0 +1,229 @@
+/*
+ * 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.
+ */
+
+#ifndef _LINUX_AUTO_DEV_IOCTL_H
+#define _LINUX_AUTO_DEV_IOCTL_H
+
+#include <linux/auto_fs.h>
+
+#ifdef __KERNEL__
+#include <linux/string.h>
+#else
+#include <string.h>
+#endif /* __KERNEL__ */
+
+#define AUTOFS_DEVICE_NAME		"autofs"
+
+#define AUTOFS_DEV_IOCTL_VERSION_MAJOR	1
+#define AUTOFS_DEV_IOCTL_VERSION_MINOR	0
+
+#define AUTOFS_DEVID_LEN		16
+
+#define AUTOFS_DEV_IOCTL_SIZE		sizeof(struct autofs_dev_ioctl)
+
+/*
+ * An ioctl interface for autofs mount point control.
+ */
+
+struct args_protover {
+	__u32	version;
+};
+
+struct args_protosubver {
+	__u32	sub_version;
+};
+
+struct args_openmount {
+	__u32	devid;
+};
+
+struct args_ready {
+	__u32	token;
+};
+
+struct args_fail {
+	__u32	token;
+	__s32	status;
+};
+
+struct args_setpipefd {
+	__s32	pipefd;
+};
+
+struct args_timeout {
+	__u64	timeout;
+};
+
+struct args_requester {
+	__u32	uid;
+	__u32	gid;
+};
+
+struct args_expire {
+	__u32	how;
+};
+
+struct args_askumount {
+	__u32	may_umount;
+};
+
+struct args_ismountpoint {
+	union {
+		struct args_in {
+			__u32	type;
+		} in;
+		struct args_out {
+			__u32	devid;
+			__u32	magic;
+		} out;
+	};
+};
+
+/*
+ * All the ioctls use this structure.
+ * When sending a path size must account for the total length
+ * of the chunk of memory otherwise is is the size of the
+ * structure.
+ */
+
+struct autofs_dev_ioctl {
+	__u32 ver_major;
+	__u32 ver_minor;
+	__u32 size;		/* total size of data passed in
+				 * including this struct */
+	__s32 ioctlfd;		/* automount command fd */
+
+	/* Command parameters */
+
+	union {
+		struct args_protover		protover;
+		struct args_protosubver		protosubver;
+		struct args_openmount		openmount;
+		struct args_ready		ready;
+		struct args_fail		fail;
+		struct args_setpipefd		setpipefd;
+		struct args_timeout		timeout;
+		struct args_requester		requester;
+		struct args_expire		expire;
+		struct args_askumount		askumount;
+		struct args_ismountpoint	ismountpoint;
+	};
+
+	char path[0];
+};
+
+static inline void init_autofs_dev_ioctl(struct autofs_dev_ioctl *in)
+{
+	memset(in, 0, sizeof(struct autofs_dev_ioctl));
+	in->ver_major = AUTOFS_DEV_IOCTL_VERSION_MAJOR;
+	in->ver_minor = AUTOFS_DEV_IOCTL_VERSION_MINOR;
+	in->size = sizeof(struct autofs_dev_ioctl);
+	in->ioctlfd = -1;
+	return;
+}
+
+/*
+ * If you change this make sure you make the corresponding change
+ * to autofs-dev-ioctl.c:lookup_ioctl()
+ */
+enum {
+	/* Get various version info */
+	AUTOFS_DEV_IOCTL_VERSION_CMD = 0x71,
+	AUTOFS_DEV_IOCTL_PROTOVER_CMD,
+	AUTOFS_DEV_IOCTL_PROTOSUBVER_CMD,
+
+	/* Open mount ioctl fd */
+	AUTOFS_DEV_IOCTL_OPENMOUNT_CMD,
+
+	/* Close mount ioctl fd */
+	AUTOFS_DEV_IOCTL_CLOSEMOUNT_CMD,
+
+	/* Mount/expire status returns */
+	AUTOFS_DEV_IOCTL_READY_CMD,
+	AUTOFS_DEV_IOCTL_FAIL_CMD,
+
+	/* Activate/deactivate autofs mount */
+	AUTOFS_DEV_IOCTL_SETPIPEFD_CMD,
+	AUTOFS_DEV_IOCTL_CATATONIC_CMD,
+
+	/* Expiry timeout */
+	AUTOFS_DEV_IOCTL_TIMEOUT_CMD,
+
+	/* Get mount last requesting uid and gid */
+	AUTOFS_DEV_IOCTL_REQUESTER_CMD,
+
+	/* Check for eligible expire candidates */
+	AUTOFS_DEV_IOCTL_EXPIRE_CMD,
+
+	/* Request busy status */
+	AUTOFS_DEV_IOCTL_ASKUMOUNT_CMD,
+
+	/* Check if path is a mountpoint */
+	AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD,
+};
+
+#define AUTOFS_IOCTL 0x93
+
+#define AUTOFS_DEV_IOCTL_VERSION \
+	_IOWR(AUTOFS_IOCTL, \
+	      AUTOFS_DEV_IOCTL_VERSION_CMD, struct autofs_dev_ioctl)
+
+#define AUTOFS_DEV_IOCTL_PROTOVER \
+	_IOWR(AUTOFS_IOCTL, \
+	      AUTOFS_DEV_IOCTL_PROTOVER_CMD, struct autofs_dev_ioctl)
+
+#define AUTOFS_DEV_IOCTL_PROTOSUBVER \
+	_IOWR(AUTOFS_IOCTL, \
+	      AUTOFS_DEV_IOCTL_PROTOSUBVER_CMD, struct autofs_dev_ioctl)
+
+#define AUTOFS_DEV_IOCTL_OPENMOUNT \
+	_IOWR(AUTOFS_IOCTL, \
+	      AUTOFS_DEV_IOCTL_OPENMOUNT_CMD, struct autofs_dev_ioctl)
+
+#define AUTOFS_DEV_IOCTL_CLOSEMOUNT \
+	_IOWR(AUTOFS_IOCTL, \
+	      AUTOFS_DEV_IOCTL_CLOSEMOUNT_CMD, struct autofs_dev_ioctl)
+
+#define AUTOFS_DEV_IOCTL_READY \
+	_IOWR(AUTOFS_IOCTL, \
+	      AUTOFS_DEV_IOCTL_READY_CMD, struct autofs_dev_ioctl)
+
+#define AUTOFS_DEV_IOCTL_FAIL \
+	_IOWR(AUTOFS_IOCTL, \
+	      AUTOFS_DEV_IOCTL_FAIL_CMD, struct autofs_dev_ioctl)
+
+#define AUTOFS_DEV_IOCTL_SETPIPEFD \
+	_IOWR(AUTOFS_IOCTL, \
+	      AUTOFS_DEV_IOCTL_SETPIPEFD_CMD, struct autofs_dev_ioctl)
+
+#define AUTOFS_DEV_IOCTL_CATATONIC \
+	_IOWR(AUTOFS_IOCTL, \
+	      AUTOFS_DEV_IOCTL_CATATONIC_CMD, struct autofs_dev_ioctl)
+
+#define AUTOFS_DEV_IOCTL_TIMEOUT \
+	_IOWR(AUTOFS_IOCTL, \
+	      AUTOFS_DEV_IOCTL_TIMEOUT_CMD, struct autofs_dev_ioctl)
+
+#define AUTOFS_DEV_IOCTL_REQUESTER \
+	_IOWR(AUTOFS_IOCTL, \
+	      AUTOFS_DEV_IOCTL_REQUESTER_CMD, struct autofs_dev_ioctl)
+
+#define AUTOFS_DEV_IOCTL_EXPIRE \
+	_IOWR(AUTOFS_IOCTL, \
+	      AUTOFS_DEV_IOCTL_EXPIRE_CMD, struct autofs_dev_ioctl)
+
+#define AUTOFS_DEV_IOCTL_ASKUMOUNT \
+	_IOWR(AUTOFS_IOCTL, \
+	      AUTOFS_DEV_IOCTL_ASKUMOUNT_CMD, struct autofs_dev_ioctl)
+
+#define AUTOFS_DEV_IOCTL_ISMOUNTPOINT \
+	_IOWR(AUTOFS_IOCTL, \
+	      AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD, struct autofs_dev_ioctl)
+
+#endif	/* _LINUX_AUTO_DEV_IOCTL_H */
--- linux-2.6.18.orig/include/linux/auto_fs.h
+++ linux-2.6.18/include/linux/auto_fs.h
@@ -17,11 +17,13 @@
 #ifdef __KERNEL__
 #include <linux/fs.h>
 #include <linux/limits.h>
+#include <linux/types.h>
+#include <linux/ioctl.h>
+#else
 #include <asm/types.h>
+#include <sys/ioctl.h>
 #endif /* __KERNEL__ */
 
-#include <linux/ioctl.h>
-
 /* This file describes autofs v3 */
 #define AUTOFS_PROTO_VERSION	3

${this.title}

Code Editor : autofs4-2.6.18-v5-update-20090903.patch