diff -Nurp linux-2.6.0.orig/fs/Kconfig linux-2.6.0/fs/Kconfig
--- linux-2.6.0.orig/fs/Kconfig	2003-12-18 10:58:57.000000000 +0800
+++ linux-2.6.0/fs/Kconfig	2005-04-04 22:28:36.000000000 +0800
@@ -452,7 +452,7 @@ config AUTOFS4_FS
 	  automounter (amd), which is a pure user space daemon.
 
 	  To use the automounter you need the user-space tools from
-	  <ftp://ftp.kernel.org/pub/linux/daemons/autofs/testing-v4/>; you also
+	  <ftp://ftp.kernel.org/pub/linux/daemons/autofs/v4/>; you also
 	  want to answer Y to "NFS file system support", below.
 
 	  To compile this support as a module, choose M here: the module will be
Files linux-2.6.0.orig/fs/autofs4/.waitq.c.rej.swp and linux-2.6.0/fs/autofs4/.waitq.c.rej.swp differ
diff -Nurp linux-2.6.0.orig/fs/autofs4/autofs_i.h linux-2.6.0/fs/autofs4/autofs_i.h
--- linux-2.6.0.orig/fs/autofs4/autofs_i.h	2003-12-18 10:59:05.000000000 +0800
+++ linux-2.6.0/fs/autofs4/autofs_i.h	2005-04-04 22:35:56.000000000 +0800
@@ -25,6 +25,8 @@
 #include <linux/string.h>
 #include <linux/wait.h>
 #include <linux/sched.h>
+#include <linux/mount.h>
+#include <linux/namei.h>
 #include <asm/current.h>
 #include <asm/uaccess.h>
 
@@ -82,7 +84,8 @@ struct autofs_wait_queue {
 	char *name;
 	/* This is for status reporting upon return */
 	int status;
-	int wait_ctr;
+	atomic_t notified;
+	atomic_t wait_ctr;
 };
 
 #define AUTOFS_SBI_MAGIC 0x6d4a556d
@@ -93,8 +96,13 @@ struct autofs_sb_info {
 	pid_t oz_pgrp;
 	int catatonic;
 	int version;
+	int sub_version;
 	unsigned long exp_timeout;
+	int reghost_enabled;
+	int needs_reghost;
 	struct super_block *sb;
+	struct semaphore wq_sem;
+	spinlock_t fs_lock;
 	struct autofs_wait_queue *queues; /* Wait queue pointer */
 };
 
@@ -120,9 +128,24 @@ 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;
 
-	return (dentry->d_flags & DCACHE_AUTOFS_PENDING) ||
-		(inf != NULL && inf->flags & AUTOFS_INF_EXPIRING);
+	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);
+	}
+
+	return pending;
+}
+
+static inline void autofs4_copy_atime(struct file *src, struct file *dst)
+{
+	dst->f_dentry->d_inode->i_atime = src->f_dentry->d_inode->i_atime;
+	return;
 }
 
 struct inode *autofs4_get_inode(struct super_block *, struct autofs_info *);
@@ -141,6 +164,7 @@ int autofs4_expire_multi(struct super_bl
 extern struct inode_operations autofs4_symlink_inode_operations;
 extern struct inode_operations autofs4_dir_inode_operations;
 extern struct inode_operations autofs4_root_inode_operations;
+extern struct file_operations autofs4_dir_operations;
 extern struct file_operations autofs4_root_operations;
 
 /* Initializing function */
@@ -157,6 +181,24 @@ enum autofs_notify
 	NFY_EXPIRE
 };
 
-int autofs4_wait(struct autofs_sb_info *,struct qstr *, enum autofs_notify);
+int autofs4_wait(struct autofs_sb_info *,struct dentry *, enum autofs_notify);
 int autofs4_wait_release(struct autofs_sb_info *,autofs_wqt_t,int);
 void autofs4_catatonic_mode(struct autofs_sb_info *);
+
+static inline int simple_positive(struct dentry *dentry)
+{
+	return dentry->d_inode && !d_unhashed(dentry);
+}
+
+static inline int simple_empty_nolock(struct dentry *dentry)
+{
+	struct dentry *child;
+	int ret = 0;
+
+	list_for_each_entry(child, &dentry->d_subdirs, d_child)
+		if (simple_positive(child))
+			goto out;
+	ret = 1;
+out:
+	return ret;
+}
diff -Nurp linux-2.6.0.orig/fs/autofs4/expire.c linux-2.6.0/fs/autofs4/expire.c
--- linux-2.6.0.orig/fs/autofs4/expire.c	2003-12-18 10:59:05.000000000 +0800
+++ linux-2.6.0/fs/autofs4/expire.c	2005-04-04 22:35:56.000000000 +0800
@@ -4,6 +4,7 @@
  *
  *  Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
  *  Copyright 1999-2000 Jeremy Fitzhardinge <jeremy@goop.org>
+ *  Copyright 2001-2003 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
@@ -12,139 +13,202 @@
  * ------------------------------------------------------------------------- */
 
 #include "autofs_i.h"
-#include <linux/mount.h>
 
-/*
- * Determine if a subtree of the namespace is busy.
- *
- * mnt is the mount tree under the autofs mountpoint
+static unsigned long now;
+
+/* Check if a dentry can be expired return 1 if it can else return 0 */
+static inline int autofs4_can_expire(struct dentry *dentry,
+					unsigned long timeout, int do_now)
+{
+	struct autofs_info *ino = autofs4_dentry_ino(dentry);
+
+	/* dentry in the process of being deleted */
+	if (ino == NULL)
+		return 0;
+
+	/* No point expiring a pending mount */
+	if (dentry->d_flags & DCACHE_AUTOFS_PENDING)
+		return 0;
+
+	if (!do_now) {
+		/* Too young to die */
+		if (time_after(ino->last_used + timeout, now))
+			return 0;
+
+		/* update last_used here :-
+		   - obviously makes sense if it is in use now
+		   - less obviously, prevents rapid-fire expire
+		     attempts if expire fails the first time */
+		ino->last_used = now;
+	}
+
+	return 1;
+}
+
+/* Check a mount point for busyness return 1 if not busy, otherwise */
+static int autofs4_check_mount(struct vfsmount *mnt, struct dentry *dentry)
+{
+	int status = 0;
+
+	DPRINTK(("autofs4_check_mount: dentry %p %.*s\n",
+		 dentry, (int)dentry->d_name.len, dentry->d_name.name));
+
+	mntget(mnt);
+	dget(dentry);
+
+	if (!follow_down(&mnt, &dentry))
+		goto done;
+
+	while (d_mountpoint(dentry) && follow_down(&mnt, &dentry))
+		;
+
+	/* This is an autofs submount, we can't expire it */
+	if (is_autofs4_dentry(dentry))
+		goto done;
+
+	/* The big question */
+	if (may_umount_tree(mnt) == 0)
+		status = 1;
+done:
+	DPRINTK(("autofs4_check_mount: returning = %d\n", status));
+	mntput(mnt);
+	dput(dentry);
+	return status;
+}
+
+/* Check a directory tree of mount points for busyness
+ * The tree is not busy iff no mountpoints are busy
+ * Return 1 if the tree is busy or 0 otherwise
  */
-static inline int is_vfsmnt_tree_busy(struct vfsmount *mnt)
+static int autofs4_check_tree(struct vfsmount *mnt,
+	       		      struct dentry *top,
+			      unsigned long timeout,
+			      int do_now)
 {
-	struct vfsmount *this_parent = mnt;
+	struct dentry *this_parent = top;
 	struct list_head *next;
-	int count;
 
-	count = atomic_read(&mnt->mnt_count) - 1;
+	DPRINTK(("autofs4_check_tree: parent %p %.*s\n",
+		 top, (int)top->d_name.len, top->d_name.name));
 
+	/* Negative dentry - give up */
+	if (!simple_positive(top))
+		return 0;
+
+	/* Timeout of a tree mount is determined by its top dentry */
+	if (!autofs4_can_expire(top, timeout, do_now))
+		return 0;
+
+	/* Is someone visiting anywhere in the tree ? */
+	if (may_umount_tree(mnt))
+		return 0;
+
+	spin_lock(&dcache_lock);
 repeat:
-	next = this_parent->mnt_mounts.next;
-	DPRINTK(("is_vfsmnt_tree_busy: mnt=%p, this_parent=%p, next=%p\n",
-		 mnt, this_parent, next));
+	next = this_parent->d_subdirs.next;
 resume:
-	for( ; next != &this_parent->mnt_mounts; next = next->next) {
-		struct vfsmount *p = list_entry(next, struct vfsmount,
-						mnt_child);
-
-		/* -1 for struct vfs_mount's normal count, 
-		   -1 to compensate for child's reference to parent */
-		count += atomic_read(&p->mnt_count) - 1 - 1;
+	while (next != &this_parent->d_subdirs) {
+		struct dentry *dentry = list_entry(next, struct dentry, d_child);
 
-		DPRINTK(("is_vfsmnt_tree_busy: p=%p, count now %d\n",
-			 p, count));
+		/* Negative dentry - give up */
+		if (!simple_positive(dentry)) {
+			next = next->next;
+			continue;
+		}
 
-		if (!list_empty(&p->mnt_mounts)) {
-			this_parent = p;
+		DPRINTK(("autofs4_check_tree: dentry %p %.*s\n",
+			 dentry, (int)dentry->d_name.len, dentry->d_name.name));
+
+		if (!simple_empty_nolock(dentry)) {
+			this_parent = dentry;
 			goto repeat;
 		}
-		/* root is busy if any leaf is busy */
-		if (atomic_read(&p->mnt_count) > 1)
-			return 1;
-	}
 
-	/* All done at this level ... ascend and resume the search. */
-	if (this_parent != mnt) {
-		next = this_parent->mnt_child.next; 
-		this_parent = this_parent->mnt_parent;
-		goto resume;
-	}
+		dentry = dget(dentry);
+		spin_unlock(&dcache_lock);
 
-	DPRINTK(("is_vfsmnt_tree_busy: count=%d\n", count));
-	return count != 0; /* remaining users? */
-}
+		if (d_mountpoint(dentry)) {
+			/* First busy => tree busy */
+			if (!autofs4_check_mount(mnt, dentry)) {
+				dput(dentry);
+				return 0;
+			}
+		}
 
-/* Traverse a dentry's list of vfsmounts and return the number of
-   non-busy mounts */
-static int check_vfsmnt(struct vfsmount *mnt, struct dentry *dentry)
-{
-	int ret = dentry->d_mounted;
-	struct vfsmount *vfs = lookup_mnt(mnt, dentry);
+		dput(dentry);
+		spin_lock(&dcache_lock);
+		next = next->next;
+	}
 
-	if (vfs) {
-		mntput(vfs);
-		if (is_vfsmnt_tree_busy(vfs))
-			ret--;
+	if (this_parent != top) {
+		next = this_parent->d_child.next;
+		this_parent = this_parent->d_parent;
+		goto resume;
 	}
-	DPRINTK(("check_vfsmnt: ret=%d\n", ret));
-	return ret;
+	spin_unlock(&dcache_lock);
+
+	return 1;
 }
 
-/* Check dentry tree for busyness.  If a dentry appears to be busy
-   because it is a mountpoint, check to see if the mounted
-   filesystem is busy. */
-static int is_tree_busy(struct vfsmount *topmnt, struct dentry *top)
+static struct dentry *autofs4_check_leaves(struct vfsmount *mnt,
+					   struct dentry *parent,
+					   unsigned long timeout,
+					   int do_now)
 {
-	struct dentry *this_parent;
+	struct dentry *this_parent = parent;
 	struct list_head *next;
-	int count;
-
-	count = atomic_read(&top->d_count);
-	
-	DPRINTK(("is_tree_busy: top=%p initial count=%d\n", 
-		 top, count));
-	this_parent = top;
-
-	if (is_autofs4_dentry(top)) {
-		count--;
-		DPRINTK(("is_tree_busy: autofs; count=%d\n", count));
-	}
 
-	if (d_mountpoint(top))
-		count -= check_vfsmnt(topmnt, top);
+	DPRINTK(("autofs4_check_leaves: parent %p %.*s\n",
+		parent, (int)parent->d_name.len, parent->d_name.name));
 
- repeat:
+	spin_lock(&dcache_lock);
+repeat:
 	next = this_parent->d_subdirs.next;
- resume:
+resume:
 	while (next != &this_parent->d_subdirs) {
-		int adj = 0;
-		struct dentry *dentry = list_entry(next, struct dentry,
-						   d_child);
-		next = next->next;
-
-		count += atomic_read(&dentry->d_count) - 1;
+		struct dentry *dentry = list_entry(next, struct dentry, d_child);
 
-		if (d_mountpoint(dentry))
-			adj += check_vfsmnt(topmnt, dentry);
-
-		if (is_autofs4_dentry(dentry)) {
-			adj++;
-			DPRINTK(("is_tree_busy: autofs; adj=%d\n",
-				 adj));
+		/* Negative dentry - give up */
+		if (!simple_positive(dentry)) {
+			next = next->next;
+			continue;
 		}
 
-		count -= adj;
+		DPRINTK(("autofs4_check_leaves: dentry %p %.*s\n",
+			dentry, (int)dentry->d_name.len, dentry->d_name.name));
 
 		if (!list_empty(&dentry->d_subdirs)) {
 			this_parent = dentry;
 			goto repeat;
 		}
 
-		if (atomic_read(&dentry->d_count) != adj) {
-			DPRINTK(("is_tree_busy: busy leaf (d_count=%d adj=%d)\n",
-				 atomic_read(&dentry->d_count), adj));
-			return 1;
+		dentry = dget(dentry);
+		spin_unlock(&dcache_lock);
+
+		if (d_mountpoint(dentry)) {
+			/* Can we expire this guy */
+			if (!autofs4_can_expire(dentry, timeout, do_now))
+				goto cont;
+
+			/* Can we umount this guy */
+			if (autofs4_check_mount(mnt, dentry))
+				return dentry;
+
 		}
+cont:
+		dput(dentry);
+		spin_lock(&dcache_lock);
+		next = next->next;
 	}
 
-	/* All done at this level ... ascend and resume the search. */
-	if (this_parent != top) {
-		next = this_parent->d_child.next; 
+	if (this_parent != parent) {
+		next = this_parent->d_child.next;
 		this_parent = this_parent->d_parent;
 		goto resume;
 	}
+	spin_unlock(&dcache_lock);
 
-	DPRINTK(("is_tree_busy: count=%d\n", count));
-	return count != 0; /* remaining users? */
+	return NULL;
 }
 
 /*
@@ -156,61 +220,94 @@ static int is_tree_busy(struct vfsmount 
 static struct dentry *autofs4_expire(struct super_block *sb,
 				     struct vfsmount *mnt,
 				     struct autofs_sb_info *sbi,
-				     int do_now)
+				     int how)
 {
-	unsigned long now = jiffies;
 	unsigned long timeout;
 	struct dentry *root = sb->s_root;
-	struct list_head *tmp;
+	struct dentry *expired = NULL;
+	struct list_head *next;
+	int do_now = how & AUTOFS_EXP_IMMEDIATE;
+	int exp_leaves = how & AUTOFS_EXP_LEAVES;
 
-	if (!sbi->exp_timeout || !root)
+	if ( !sbi->exp_timeout || !root )
 		return NULL;
 
+	now = jiffies;
 	timeout = sbi->exp_timeout;
 
 	spin_lock(&dcache_lock);
-	for(tmp = root->d_subdirs.next;
-	    tmp != &root->d_subdirs; 
-	    tmp = tmp->next) {
-		struct autofs_info *ino;
-		struct dentry *dentry = list_entry(tmp, struct dentry, d_child);
+	next = root->d_subdirs.next;
 
-		if (dentry->d_inode == NULL)
+	/* On exit from the loop expire is set to a dgot dentry
+	 * to expire or it's NULL */
+	while ( next != &root->d_subdirs ) {
+		struct dentry *dentry = list_entry(next, struct dentry, d_child);
+
+		/* Negative dentry - give up */
+		if ( !simple_positive(dentry) ) {
+			next = next->next;
 			continue;
+		}
 
-		ino = autofs4_dentry_ino(dentry);
+		dentry = dget(dentry);
+		spin_unlock(&dcache_lock);
 
-		if (ino == NULL) {
-			/* dentry in the process of being deleted */
-			continue;
+		/* Case 1: indirect mount or top level direct mount */
+		if (d_mountpoint(dentry)) {
+			DPRINTK(("autofs4_expire: checking mountpoint %p %.*s\n",
+			 dentry, (int)dentry->d_name.len, dentry->d_name.name));
+
+			/* Can we expire this guy */
+			if (!autofs4_can_expire(dentry, timeout, do_now))
+				goto next;
+
+			/* Can we umount this guy */
+			if (autofs4_check_mount(mnt, dentry)) {
+				expired = dentry;
+				break;
+			}
+			goto next;
 		}
 
-		/* No point expiring a pending mount */
-		if (dentry->d_flags & DCACHE_AUTOFS_PENDING)
-			continue;
+		if ( simple_empty(dentry) )
+			goto next;
 
-		if (!do_now) {
-			/* Too young to die */
-			if (time_after(ino->last_used + timeout, now))
-				continue;
-		
-			/* update last_used here :- 
-			   - obviously makes sense if it is in use now
-			   - less obviously, prevents rapid-fire expire
-			     attempts if expire fails the first time */
-			ino->last_used = now;
+		/* 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_check_tree(mnt, dentry, timeout, do_now)) {
+				struct autofs_info *inf = autofs4_dentry_ino(dentry);
+
+				/* Set this flag early to catch sys_chdir and the like */
+				inf->flags |= AUTOFS_INF_EXPIRING;
+				spin_unlock(&sbi->fs_lock);
+				expired = dentry;
+				break;
+			}
+			spin_unlock(&sbi->fs_lock);
+		/* Case 3: direct mount, expire individual leaves */
+		} else {
+			expired = autofs4_check_leaves(mnt, dentry, timeout, do_now);
+			if (expired) {
+				dput(dentry);
+				break;
+			}
 		}
-		if (!is_tree_busy(mnt, dentry)) {
-			DPRINTK(("autofs_expire: returning %p %.*s\n",
-				 dentry, (int)dentry->d_name.len, dentry->d_name.name));
-			/* Start from here next time */
-			list_del(&root->d_subdirs);
-			list_add(&root->d_subdirs, &dentry->d_child);
-			dget(dentry);
-			spin_unlock(&dcache_lock);
+next:
+		dput(dentry);
+		spin_lock(&dcache_lock);
+		next = next->next;
+	}
 
-			return dentry;
-		}
+	if ( expired ) {
+		DPRINTK(("autofs4_expire: returning %p %.*s\n",
+			 expired, (int)expired->d_name.len, expired->d_name.name));
+		spin_lock(&dcache_lock);
+		list_del(&expired->d_parent->d_subdirs);
+		list_add(&expired->d_parent->d_subdirs, &expired->d_child);
+		spin_unlock(&dcache_lock);
+		return expired;
 	}
 	spin_unlock(&dcache_lock);
 
@@ -263,7 +360,7 @@ int autofs4_expire_multi(struct super_bl
 		/* This is synchronous because it makes the daemon a
                    little easier */
 		de_info->flags |= AUTOFS_INF_EXPIRING;
-		ret = autofs4_wait(sbi, &dentry->d_name, NFY_EXPIRE);
+		ret = autofs4_wait(sbi, dentry, NFY_EXPIRE);
 		de_info->flags &= ~AUTOFS_INF_EXPIRING;
 		dput(dentry);
 	}
diff -Nurp linux-2.6.0.orig/fs/autofs4/inode.c linux-2.6.0/fs/autofs4/inode.c
--- linux-2.6.0.orig/fs/autofs4/inode.c	2003-12-18 10:59:16.000000000 +0800
+++ linux-2.6.0/fs/autofs4/inode.c	2005-04-04 22:35:56.000000000 +0800
@@ -187,6 +187,7 @@ int autofs4_fill_super(struct super_bloc
 	struct file * pipe;
 	int pipefd;
 	struct autofs_sb_info *sbi;
+	struct autofs_info *ino;
 	int minproto, maxproto;
 
 	sbi = (struct autofs_sb_info *) kmalloc(sizeof(*sbi), GFP_KERNEL);
@@ -203,6 +204,9 @@ int autofs4_fill_super(struct super_bloc
 	sbi->oz_pgrp = process_group(current);
 	sbi->sb = s;
 	sbi->version = 0;
+	sbi->sub_version = 0;
+	init_MUTEX(&sbi->wq_sem);
+	spin_lock_init(&sbi->fs_lock);
 	sbi->queues = NULL;
 	s->s_blocksize = 1024;
 	s->s_blocksize_bits = 10;
@@ -212,7 +216,14 @@ int autofs4_fill_super(struct super_bloc
 	/*
 	 * Get the root inode and dentry, but defer checking for errors.
 	 */
-	root_inode = autofs4_get_inode(s, autofs4_mkroot(sbi));
+	ino = autofs4_mkroot(sbi);
+	if (!ino)
+		goto fail_free;
+	root_inode = autofs4_get_inode(s, ino);
+	kfree(ino);
+	if (!root_inode)
+		goto fail_free;
+
 	root_inode->i_op = &autofs4_root_inode_operations;
 	root_inode->i_fop = &autofs4_root_operations;
 	root = d_alloc_root(root_inode);
@@ -241,6 +252,7 @@ int autofs4_fill_super(struct super_bloc
 	}
 
 	sbi->version = maxproto > AUTOFS_MAX_PROTO_VERSION ? AUTOFS_MAX_PROTO_VERSION : maxproto;
+	sbi->sub_version = AUTOFS_PROTO_SUBVERSION;
 
 	DPRINTK(("autofs: pipe fd = %d, pgrp = %u\n", pipefd, sbi->oz_pgrp));
 	pipe = fget(pipefd);
@@ -311,7 +323,7 @@ struct inode *autofs4_get_inode(struct s
 	if (S_ISDIR(inf->mode)) {
 		inode->i_nlink = 2;
 		inode->i_op = &autofs4_dir_inode_operations;
-		inode->i_fop = &simple_dir_operations;
+		inode->i_fop = &autofs4_dir_operations;
 	} else if (S_ISLNK(inf->mode)) {
 		inode->i_size = inf->size;
 		inode->i_op = &autofs4_symlink_inode_operations;
diff -Nurp linux-2.6.0.orig/fs/autofs4/root.c linux-2.6.0/fs/autofs4/root.c
--- linux-2.6.0.orig/fs/autofs4/root.c	2003-12-18 10:58:04.000000000 +0800
+++ linux-2.6.0/fs/autofs4/root.c	2005-04-04 22:28:36.000000000 +0800
@@ -4,6 +4,7 @@
  *
  *  Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
  *  Copyright 1999-2000 Jeremy Fitzhardinge <jeremy@goop.org>
+ *  Copyright 2001-2003 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
@@ -18,25 +19,35 @@
 #include <linux/smp_lock.h>
 #include "autofs_i.h"
 
-static struct dentry *autofs4_dir_lookup(struct inode *,struct dentry *, struct nameidata *);
 static int autofs4_dir_symlink(struct inode *,struct dentry *,const char *);
 static int autofs4_dir_unlink(struct inode *,struct dentry *);
 static int autofs4_dir_rmdir(struct inode *,struct dentry *);
 static int autofs4_dir_mkdir(struct inode *,struct dentry *,int);
 static int autofs4_root_ioctl(struct inode *, struct file *,unsigned int,unsigned long);
-static struct dentry *autofs4_root_lookup(struct inode *,struct dentry *, struct nameidata *);
+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 int autofs4_dcache_readdir(struct file *, void *, filldir_t);
 
 struct file_operations autofs4_root_operations = {
 	.open		= dcache_dir_open,
 	.release	= dcache_dir_close,
-	.llseek		= dcache_dir_lseek,
 	.read		= generic_read_dir,
-	.readdir	= dcache_readdir,
+	.readdir	= autofs4_root_readdir,
 	.ioctl		= autofs4_root_ioctl,
 };
 
+struct file_operations autofs4_dir_operations = {
+	.open		= autofs4_dir_open,
+	.release	= autofs4_dir_close,
+	.read		= generic_read_dir,
+	.readdir	= autofs4_dir_readdir,
+};
+
 struct inode_operations autofs4_root_inode_operations = {
-	.lookup		= autofs4_root_lookup,
+	.lookup		= autofs4_lookup,
 	.unlink		= autofs4_dir_unlink,
 	.symlink	= autofs4_dir_symlink,
 	.mkdir		= autofs4_dir_mkdir,
@@ -44,19 +55,44 @@ struct inode_operations autofs4_root_ino
 };
 
 struct inode_operations autofs4_dir_inode_operations = {
-	.lookup		= autofs4_dir_lookup,
+	.lookup		= autofs4_lookup,
 	.unlink		= autofs4_dir_unlink,
 	.symlink	= autofs4_dir_symlink,
 	.mkdir		= autofs4_dir_mkdir,
 	.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(("autofs4_root_readdir called, filp->f_pos = %lld\n",
+			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(("autofs4_root_readdir: needs_reghost = %d\n",
+			sbi->needs_reghost));
+
+	return autofs4_dcache_readdir(file, dirent, filldir);
+}
+
 /* Update usage from here to top of tree, so that scan of
    top-level directories will give a useful result */
 static void autofs4_update_usage(struct dentry *dentry)
 {
 	struct dentry *top = dentry->d_sb->s_root;
 
+	spin_lock(&dcache_lock);
 	for(; dentry != top; dentry = dentry->d_parent) {
 		struct autofs_info *ino = autofs4_dentry_ino(dentry);
 
@@ -65,11 +101,194 @@ static void autofs4_update_usage(struct 
 			ino->last_used = jiffies;
 		}
 	}
+	spin_unlock(&dcache_lock);
+}
+
+/*
+ * From 2.4 kernel readdir.c
+ */
+static int autofs4_dcache_readdir(struct file * filp, void * dirent, filldir_t filldir)
+{
+	int i;
+	struct dentry *dentry = filp->f_dentry;
+
+	i = filp->f_pos;
+	switch (i) {
+		case 0:
+			if (filldir(dirent, ".", 1, i, dentry->d_inode->i_ino, DT_DIR) < 0)
+				break;
+			i++;
+			filp->f_pos++;
+			/* fallthrough */
+		case 1:
+			if (filldir(dirent, "..", 2, i, dentry->d_parent->d_inode->i_ino, DT_DIR) < 0)
+				break;
+			i++;
+			filp->f_pos++;
+			/* fallthrough */
+		default: {
+			struct list_head *list;
+			int j = i-2;
+
+			spin_lock(&dcache_lock);
+			list = dentry->d_subdirs.next;
+
+			for (;;) {
+				if (list == &dentry->d_subdirs) {
+					spin_unlock(&dcache_lock);
+					return 0;
+				}
+				if (!j)
+					break;
+				j--;
+				list = list->next;
+			}
+
+			while(1) {
+				struct dentry *de = list_entry(list, struct dentry, d_child);
+
+				if (!d_unhashed(de) && de->d_inode) {
+					spin_unlock(&dcache_lock);
+					if (filldir(dirent, de->d_name.name, de->d_name.len, filp->f_pos, de->d_inode->i_ino, DT_UNKNOWN) < 0)
+						break;
+					spin_lock(&dcache_lock);
+				}
+				filp->f_pos++;
+				list = list->next;
+				if (list != &dentry->d_subdirs)
+					continue;
+				spin_unlock(&dcache_lock);
+				break;
+			}
+		}
+	}
+	return 0;
+}
+
+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);
+	int status;
+
+	DPRINTK(("autofs4_dir_open: file=%p dentry=%p %.*s\n",
+		file, dentry, dentry->d_name.len, dentry->d_name.name));
+
+	if (autofs4_oz_mode(sbi))
+		goto out;
+
+	if (autofs4_ispending(dentry)) {
+		DPRINTK(("autofs4_dir_open: dentry busy\n"));
+		return -EBUSY;
+	}
+
+	if (!d_mountpoint(dentry) && dentry->d_op && dentry->d_op->d_revalidate) {
+		struct nameidata nd;
+		int empty;
+
+		/* In case there are stale directory dentrys from a failed mount */
+		spin_lock(&dcache_lock);
+		empty = list_empty(&dentry->d_subdirs);
+		spin_unlock(&dcache_lock);
+
+		if (!empty)
+			d_invalidate(dentry);
+
+		nd.flags = LOOKUP_DIRECTORY;
+		status = (dentry->d_op->d_revalidate)(dentry, &nd);
+
+		if (!status)
+			return -ENOENT;
+	}
+
+	if (d_mountpoint(dentry)) {
+		struct file *fp = NULL;
+		struct vfsmount *fp_mnt = mntget(mnt);
+		struct dentry *fp_dentry = dget(dentry);
+
+		while (follow_down(&fp_mnt, &fp_dentry) && d_mountpoint(fp_dentry));
+
+		fp = dentry_open(fp_dentry, fp_mnt, file->f_flags);
+		status = PTR_ERR(fp);
+		if (IS_ERR(fp)) {
+			file->private_data = NULL;
+			return status;
+		}
+		file->private_data = fp;
+	}
+out:
+	return 0;
+}
+
+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);
+
+	DPRINTK(("autofs4_dir_close: file=%p dentry=%p %.*s\n",
+		file, dentry, dentry->d_name.len, dentry->d_name.name));
+
+	if (autofs4_oz_mode(sbi))
+		goto out;
+
+	if (autofs4_ispending(dentry)) {
+		DPRINTK(("autofs4_dir_close: dentry busy\n"));
+		return -EBUSY;
+	}
+
+	if (d_mountpoint(dentry)) {
+		struct file *fp = file->private_data;
+
+		if (!fp)
+			return -ENOENT;
+
+		filp_close(fp, current->files);
+		file->private_data = NULL;
+	}
+out:
+	return 0;
+}
+
+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);
+	int status;
+
+	DPRINTK(("autofs4_readdir: file=%p dentry=%p %.*s\n",
+		file, dentry, dentry->d_name.len, dentry->d_name.name));
+
+	if (autofs4_oz_mode(sbi))
+		goto out;
+
+	if (autofs4_ispending(dentry)) {
+		DPRINTK(("autofs4_readdir: dentry busy\n"));
+		return -EBUSY;
+	}
+
+	if (d_mountpoint(dentry)) {
+		struct file *fp = file->private_data;
+
+		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 autofs4_dcache_readdir(file, dirent, filldir);
 }
 
 static int try_to_fill_dentry(struct dentry *dentry, 
 			      struct super_block *sb,
-			      struct autofs_sb_info *sbi)
+			      struct autofs_sb_info *sbi, int flags)
 {
 	struct autofs_info *de_info = autofs4_dentry_ino(dentry);
 	int status = 0;
@@ -78,11 +297,10 @@ static int try_to_fill_dentry(struct den
            when expiration is done to trigger mount request with a new
            dentry */
 	if (de_info && (de_info->flags & AUTOFS_INF_EXPIRING)) {
-		DPRINTK(("try_to_fill_entry: waiting for expire %p name=%.*s, flags&PENDING=%s de_info=%p de_info->flags=%x\n",
-			 dentry, dentry->d_name.len, dentry->d_name.name, 
-			 dentry->d_flags & DCACHE_AUTOFS_PENDING?"t":"f",
-			 de_info, de_info?de_info->flags:0));
-		status = autofs4_wait(sbi, &dentry->d_name, NFY_NONE);
+		DPRINTK(("try_to_fill_entry: waiting for expire %p name=%.*s\n",
+			 dentry, dentry->d_name.len, dentry->d_name.name));
+
+		status = autofs4_wait(sbi, dentry, NFY_NONE);
 		
 		DPRINTK(("try_to_fill_entry: expire done status=%d\n", status));
 		
@@ -93,11 +311,11 @@ static int try_to_fill_dentry(struct den
 		 dentry, dentry->d_name.len, dentry->d_name.name, dentry->d_inode));
 
 	/* Wait for a pending mount, triggering one if there isn't one already */
-	while(dentry->d_inode == NULL) {
-		DPRINTK(("try_to_fill_entry: waiting for mount name=%.*s, de_info=%p de_info->flags=%x\n",
-			 dentry->d_name.len, dentry->d_name.name, 
-			 de_info, de_info?de_info->flags:0));
-		status = autofs4_wait(sbi, &dentry->d_name, NFY_MOUNT);
+	if (dentry->d_inode == NULL) {
+		DPRINTK(("try_to_fill_entry: waiting for mount name=%.*s\n",
+			 dentry->d_name.len, dentry->d_name.name));
+
+		status = autofs4_wait(sbi, dentry, NFY_MOUNT);
 		 
 		DPRINTK(("try_to_fill_entry: mount done status=%d\n", status));
 
@@ -107,54 +325,66 @@ static int try_to_fill_dentry(struct den
 		/* Turn this into a real negative dentry? */
 		if (status == -ENOENT) {
 			dentry->d_time = jiffies + AUTOFS_NEGATIVE_TIMEOUT;
+			spin_lock(&dentry->d_lock);
 			dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
+			spin_unlock(&dentry->d_lock);
 			return 1;
 		} else if (status) {
 			/* Return a negative dentry, but leave it "pending" */
 			return 1;
 		}
-	}
+	/* Trigger mount for path component or follow link */
+	} else if (flags & (LOOKUP_CONTINUE | LOOKUP_DIRECTORY) ||
+			current->link_count) {
+		DPRINTK(("try_to_fill_entry: waiting for mount name=%.*s\n",
+			dentry->d_name.len, dentry->d_name.name));
 
-	/* If this is an unused directory that isn't a mount point,
-	   bitch at the daemon and fix it in user space */
-	spin_lock(&dcache_lock);
-	if (S_ISDIR(dentry->d_inode->i_mode) &&
-	    !d_mountpoint(dentry) && 
-	    list_empty(&dentry->d_subdirs)) {
-		DPRINTK(("try_to_fill_entry: mounting existing dir\n"));
-		spin_unlock(&dcache_lock);
-		return autofs4_wait(sbi, &dentry->d_name, NFY_MOUNT) == 0;
+		spin_lock(&dentry->d_lock);
+		dentry->d_flags |= DCACHE_AUTOFS_PENDING;
+		spin_unlock(&dentry->d_lock);
+		status = autofs4_wait(sbi, dentry, NFY_MOUNT);
+
+		DPRINTK(("try_to_fill_entry: mount done status=%d\n", status));
+
+		if (status) {
+			spin_lock(&dentry->d_lock);
+			dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
+			spin_unlock(&dentry->d_lock);
+			return 0;
+		}
 	}
-	spin_unlock(&dcache_lock);
 
 	/* We don't update the usages for the autofs daemon itself, this
 	   is necessary for recursive autofs mounts */
 	if (!autofs4_oz_mode(sbi))
 		autofs4_update_usage(dentry);
 
+	spin_lock(&dentry->d_lock);
 	dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
+	spin_unlock(&dentry->d_lock);
+
 	return 1;
 }
 
-
 /*
  * Revalidate is called on every cache lookup.  Some of those
  * cache lookups may actually happen while the dentry is not
  * yet completely filled in, and revalidate has to delay such
  * lookups..
  */
-static int autofs4_root_revalidate(struct dentry * dentry, struct nameidata *nd)
+static int autofs4_revalidate(struct dentry * dentry, struct nameidata *nd)
 {
 	struct inode * dir = dentry->d_parent->d_inode;
 	struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
 	int oz_mode = autofs4_oz_mode(sbi);
+	int flags = nd ? nd->flags : 0;
+	int status = 1;
 
 	/* Pending dentry */
 	if (autofs4_ispending(dentry)) {
-		if (autofs4_oz_mode(sbi))
-			return 1;
-		else
-			return try_to_fill_dentry(dentry, dir->i_sb, sbi);
+		if (!oz_mode)
+			status = try_to_fill_dentry(dentry, dir->i_sb, sbi, flags);
+		return status;
 	}
 
 	/* Negative dentry.. invalidate if "old" */
@@ -166,13 +396,12 @@ static int autofs4_root_revalidate(struc
 	if (S_ISDIR(dentry->d_inode->i_mode) &&
 	    !d_mountpoint(dentry) && 
 	    list_empty(&dentry->d_subdirs)) {
-		DPRINTK(("autofs_root_revalidate: dentry=%p %.*s, emptydir\n",
+		DPRINTK(("autofs4_root_revalidate: dentry=%p %.*s, emptydir\n",
 			 dentry, dentry->d_name.len, dentry->d_name.name));
 		spin_unlock(&dcache_lock);
-		if (oz_mode)
-			return 1;
-		else
-			return try_to_fill_dentry(dentry, dir->i_sb, sbi);
+		if (!oz_mode)
+			status = try_to_fill_dentry(dentry, dir->i_sb, sbi, flags);
+		return status;
 	}
 	spin_unlock(&dcache_lock);
 
@@ -183,16 +412,6 @@ static int autofs4_root_revalidate(struc
 	return 1;
 }
 
-static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd)
-{
-	struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
-
-	if (!autofs4_oz_mode(sbi))
-		autofs4_update_usage(dentry);
-
-	return 1;
-}
-
 static void autofs4_dentry_release(struct dentry *de)
 {
 	struct autofs_info *inf;
@@ -212,7 +431,7 @@ static void autofs4_dentry_release(struc
 
 /* For dentries of directories in the root dir */
 static struct dentry_operations autofs4_root_dentry_operations = {
-	.d_revalidate	= autofs4_root_revalidate,
+	.d_revalidate	= autofs4_revalidate,
 	.d_release	= autofs4_dentry_release,
 };
 
@@ -222,29 +441,13 @@ static struct dentry_operations autofs4_
 	.d_release	= autofs4_dentry_release,
 };
 
-/* Lookups in non-root dirs never find anything - if it's there, it's
-   already in the dcache */
-/* SMP-safe */
-static struct dentry *autofs4_dir_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
-{
-#if 0
-	DPRINTK(("autofs_dir_lookup: ignoring lookup of %.*s/%.*s\n",
-		 dentry->d_parent->d_name.len, dentry->d_parent->d_name.name,
-		 dentry->d_name.len, dentry->d_name.name));
-#endif
-
-	dentry->d_fsdata = NULL;
-	d_add(dentry, NULL);
-	return NULL;
-}
-
 /* Lookups in the root directory */
-static struct dentry *autofs4_root_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
+static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
 {
 	struct autofs_sb_info *sbi;
 	int oz_mode;
 
-	DPRINTK(("autofs_root_lookup: name = %.*s\n", 
+	DPRINTK(("autofs4_root_lookup: name = %.*s\n",
 		 dentry->d_name.len, dentry->d_name.name));
 
 	if (dentry->d_name.len > NAME_MAX)
@@ -252,9 +455,8 @@ static struct dentry *autofs4_root_looku
 
 	sbi = autofs4_sbi(dir->i_sb);
 
-	lock_kernel();
 	oz_mode = autofs4_oz_mode(sbi);
-	DPRINTK(("autofs_lookup: pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d\n",
+	DPRINTK(("autofs4_lookup: pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d\n",
 		 current->pid, process_group(current), sbi->catatonic, oz_mode));
 
 	/*
@@ -285,12 +487,16 @@ static struct dentry *autofs4_root_looku
 	 * a signal. If so we can force a restart..
 	 */
 	if (dentry->d_flags & DCACHE_AUTOFS_PENDING) {
+		/* See if we were interrupted */
 		if (signal_pending(current)) {
-			unlock_kernel();
-			return ERR_PTR(-ERESTARTNOINTR);
+			sigset_t *sigset = &current->pending.signal;
+			if (sigismember (sigset, SIGKILL) ||
+			    sigismember (sigset, SIGQUIT) ||
+			    sigismember (sigset, SIGINT)) {
+			    return ERR_PTR(-ERESTARTNOINTR);
+			}
 		}
 	}
-	unlock_kernel();
 
 	/*
 	 * If this dentry is unhashed, then we shouldn't honour this
@@ -313,27 +519,21 @@ static int autofs4_dir_symlink(struct in
 	struct inode *inode;
 	char *cp;
 
-	DPRINTK(("autofs_dir_symlink: %s <- %.*s\n", symname, 
+	DPRINTK(("autofs4_dir_symlink: %s <- %.*s\n", symname,
 		 dentry->d_name.len, dentry->d_name.name));
 
-	lock_kernel();
-	if (!autofs4_oz_mode(sbi)) {
-		unlock_kernel();
+	if (!autofs4_oz_mode(sbi))
 		return -EACCES;
-	}
 
 	ino = autofs4_init_ino(ino, sbi, S_IFLNK | 0555);
-	if (ino == NULL) {
-		unlock_kernel();
+	if (ino == NULL)
 		return -ENOSPC;
-	}
 
 	ino->size = strlen(symname);
 	ino->u.symlink = cp = kmalloc(ino->size + 1, GFP_KERNEL);
 
 	if (cp == NULL) {
 		kfree(ino);
-		unlock_kernel();
 		return -ENOSPC;
 	}
 
@@ -353,7 +553,6 @@ static int autofs4_dir_symlink(struct in
 
 	dir->i_mtime = CURRENT_TIME;
 
-	unlock_kernel();
 	return 0;
 }
 
@@ -370,7 +569,7 @@ static int autofs4_dir_symlink(struct in
  * If a process is blocked on the dentry waiting for the expire to finish,
  * it will invalidate the dentry and try to mount with a new one.
  *
- * Also see autofs_dir_rmdir().. 
+ * Also see autofs4_dir_rmdir()..
  */
 static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry)
 {
@@ -378,11 +577,8 @@ static int autofs4_dir_unlink(struct ino
 	struct autofs_info *ino = autofs4_dentry_ino(dentry);
 	
 	/* This allows root to remove symlinks */
-	lock_kernel();
-	if ( !autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN) ) {
-		unlock_kernel();
+	if ( !autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN) )
 		return -EACCES;
-	}
 
 	dput(ino->dentry);
 
@@ -393,8 +589,6 @@ static int autofs4_dir_unlink(struct ino
 
 	d_drop(dentry);
 
-	unlock_kernel();
-	
 	return 0;
 }
 
@@ -403,16 +597,12 @@ static int autofs4_dir_rmdir(struct inod
 	struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
 	struct autofs_info *ino = autofs4_dentry_ino(dentry);
 	
-	lock_kernel();
-	if (!autofs4_oz_mode(sbi)) {
-		unlock_kernel();
+	if (!autofs4_oz_mode(sbi))
 		return -EACCES;
-	}
 
 	spin_lock(&dcache_lock);
 	if (!list_empty(&dentry->d_subdirs)) {
 		spin_unlock(&dcache_lock);
-		unlock_kernel();
 		return -ENOTEMPTY;
 	}
 	__d_drop(dentry);
@@ -426,32 +616,24 @@ static int autofs4_dir_rmdir(struct inod
 	if (dir->i_nlink)
 		dir->i_nlink--;
 
-	unlock_kernel();
 	return 0;
 }
 
-
-
 static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 {
 	struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
 	struct autofs_info *ino = autofs4_dentry_ino(dentry);
 	struct inode *inode;
 
-	lock_kernel();
-	if ( !autofs4_oz_mode(sbi) ) {
-		unlock_kernel();
+	if ( !autofs4_oz_mode(sbi) )
 		return -EACCES;
-	}
 
-	DPRINTK(("autofs_dir_mkdir: dentry %p, creating %.*s\n",
+	DPRINTK(("autofs4_dir_mkdir: dentry %p, creating %.*s\n",
 		 dentry, dentry->d_name.len, dentry->d_name.name));
 
 	ino = autofs4_init_ino(ino, sbi, S_IFDIR | 0555);
-	if (ino == NULL) {
-		unlock_kernel();
+	if (ino == NULL)
 		return -ENOSPC;
-	}
 
 	inode = autofs4_get_inode(dir->i_sb, ino);
 	d_instantiate(dentry, inode);
@@ -467,7 +649,6 @@ static int autofs4_dir_mkdir(struct inod
 	dir->i_nlink++;
 	dir->i_mtime = CURRENT_TIME;
 
-	unlock_kernel();
 	return 0;
 }
 
@@ -496,7 +677,68 @@ static inline int autofs4_get_protover(s
 	return put_user(sbi->version, p);
 }
 
-/* Identify autofs_dentries - this is so we can tell if there's
+/* Return protocol sub version */
+static inline int autofs4_get_protosubver(struct autofs_sb_info *sbi, int *p)
+{
+	return put_user(sbi->sub_version, p);
+}
+
+/*
+ * 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 *p)
+{
+	int status;
+
+	DPRINTK(("autofs_ask_reghost: returning %d\n", 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 *p)
+{
+	int status;
+	int val;
+
+	status = get_user(val, p);
+
+	DPRINTK(("autofs4_toggle_reghost: reghost = %d\n", 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 *p)
+{
+	int status = 0;
+
+	if (may_umount(mnt) == 0)
+		status = 1;
+
+	DPRINTK(("autofs_ask_umount: returning %d\n", status));
+
+	status = put_user(status, p);
+
+	return status;
+}
+
+/* Identify autofs4_dentries - this is so we can tell if there's
    an extra dentry refcount or not.  We only hold a refcount on the
    dentry if its non-negative (ie, d_inode != NULL)
 */
@@ -517,7 +759,7 @@ static int autofs4_root_ioctl(struct ino
 {
 	struct autofs_sb_info *sbi = autofs4_sbi(inode->i_sb);
 
-	DPRINTK(("autofs_ioctl: cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u\n",
+	DPRINTK(("autofs4_root_ioctl: cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u\n",
 		 cmd,arg,sbi,process_group(current)));
 
 	if ( _IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) ||
@@ -537,9 +779,19 @@ static int autofs4_root_ioctl(struct ino
 		return 0;
 	case AUTOFS_IOC_PROTOVER: /* Get protocol version */
 		return autofs4_get_protover(sbi, (int *)arg);
+	case AUTOFS_IOC_PROTOSUBVER: /* Get protocol sub version */
+		return autofs4_get_protosubver(sbi, (int *)arg);
 	case AUTOFS_IOC_SETTIMEOUT:
 		return autofs4_get_set_timeout(sbi,(unsigned long *)arg);
 
+	case AUTOFS_IOC_TOGGLEREGHOST:
+		return autofs4_toggle_reghost(sbi, (int *) arg);
+	case AUTOFS_IOC_ASKREGHOST:
+		return autofs4_ask_reghost(sbi, (int *) arg);
+
+	case AUTOFS_IOC_ASKUMOUNT:
+		return autofs4_ask_umount(filp->f_vfsmnt, (int *) arg);
+
 	/* return a single thing to expire */
 	case AUTOFS_IOC_EXPIRE:
 		return autofs4_expire_run(inode->i_sb,filp->f_vfsmnt,sbi,
diff -Nurp linux-2.6.0.orig/fs/autofs4/waitq.c linux-2.6.0/fs/autofs4/waitq.c
--- linux-2.6.0.orig/fs/autofs4/waitq.c	2003-12-18 10:59:41.000000000 +0800
+++ linux-2.6.0/fs/autofs4/waitq.c	2005-04-04 22:34:09.000000000 +0800
@@ -3,6 +3,7 @@
  * linux/fs/autofs/waitq.c
  *
  *  Copyright 1997-1998 Transmeta Corporation -- All Rights Reserved
+ *  Copyright 2001-2003 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
@@ -37,7 +38,7 @@ void autofs4_catatonic_mode(struct autof
 		wq->status = -ENOENT; /* Magic is gone - report failure */
 		kfree(wq->name);
 		wq->name = NULL;
-		wake_up(&wq->queue);
+		wake_up_interruptible(&wq->queue);
 		wq = nwq;
 	}
 	if (sbi->pipe) {
@@ -90,7 +91,7 @@ static void autofs4_notify_daemon(struct
 	union autofs_packet_union pkt;
 	size_t pktsz;
 
-	DPRINTK(("autofs_notify: wait id = 0x%08lx, name = %.*s, type=%d\n",
+	DPRINTK(("autofs4_notify_daemon: wait id = 0x%08lx, name = %.*s, type=%d\n",
 		 wq->wait_queue_token, wq->len, wq->name, type));
 
 	memset(&pkt,0,sizeof pkt); /* For security reasons */
@@ -116,7 +117,7 @@ static void autofs4_notify_daemon(struct
 		memcpy(ep->name, wq->name, wq->len);
 		ep->name[wq->len] = '\0';
 	} else {
-		printk("autofs_notify_daemon: bad type %d!\n", type);
+		printk("autofs4_notify_daemon: bad type %d!\n", type);
 		return;
 	}
 
@@ -124,62 +125,110 @@ static void autofs4_notify_daemon(struct
 		autofs4_catatonic_mode(sbi);
 }
 
-int autofs4_wait(struct autofs_sb_info *sbi, struct qstr *name,
+static int autofs4_getpath(struct autofs_sb_info *sbi,
+			   struct dentry *dentry, char **name)
+{
+	struct dentry *root = sbi->sb->s_root;
+	struct dentry *tmp;
+	char *buf = *name;
+	char *p;
+	int len = 0;
+
+	spin_lock(&dcache_lock);
+	for (tmp = dentry ; tmp != root ; tmp = tmp->d_parent)
+		len += tmp->d_name.len + 1;
+
+	if (--len > NAME_MAX) {
+		spin_unlock(&dcache_lock);
+		return 0;
+	}
+
+	*(buf + len) = '\0';
+	p = buf + len - dentry->d_name.len;
+	strncpy(p, dentry->d_name.name, dentry->d_name.len);
+
+	for (tmp = dentry->d_parent; tmp != root ; tmp = tmp->d_parent) {
+		*(--p) = '/';
+		p -= tmp->d_name.len;
+		strncpy(p, tmp->d_name.name, tmp->d_name.len);
+	}
+	spin_unlock(&dcache_lock);
+
+	return len;
+}
+
+int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry,
 		enum autofs_notify notify)
 {
 	struct autofs_wait_queue *wq;
-	int status;
+	char *name;
+	int len, status;
 
 	/* In catatonic mode, we don't wait for nobody */
 	if ( sbi->catatonic )
 		return -ENOENT;
 	
-	/* We shouldn't be able to get here, but just in case */
-	if ( name->len > NAME_MAX )
+	name = kmalloc(NAME_MAX + 1, GFP_KERNEL);
+	if (!name)
+		return -ENOMEM;
+
+	len = autofs4_getpath(sbi, dentry, &name);
+	if (!len) {
+		kfree(name);
 		return -ENOENT;
+	}
+
+	if (down_interruptible(&sbi->wq_sem)) {
+		kfree(name);
+		return -EINTR;
+	}
 
-	for ( wq = sbi->queues ; wq ; wq = wq->next ) {
-		if ( wq->hash == name->hash &&
-		     wq->len == name->len &&
-		     wq->name && !memcmp(wq->name,name->name,name->len) )
+	for (wq = sbi->queues ; wq ; wq = wq->next) {
+		if (wq->hash == dentry->d_name.hash &&
+		    wq->len == len &&
+		    wq->name && !memcmp(wq->name, name, len))
 			break;
 	}
-	
+
 	if ( !wq ) {
 		/* Create a new wait queue */
 		wq = kmalloc(sizeof(struct autofs_wait_queue),GFP_KERNEL);
-		if ( !wq )
-			return -ENOMEM;
-
-		wq->name = kmalloc(name->len,GFP_KERNEL);
-		if ( !wq->name ) {
-			kfree(wq);
+		if ( !wq ) {
+			kfree(name);
+			up(&sbi->wq_sem);
 			return -ENOMEM;
 		}
+
 		wq->wait_queue_token = autofs4_next_wait_queue;
 		if (++autofs4_next_wait_queue == 0)
 			autofs4_next_wait_queue = 1;
-		init_waitqueue_head(&wq->queue);
-		wq->hash = name->hash;
-		wq->len = name->len;
-		wq->status = -EINTR; /* Status return if interrupted */
-		memcpy(wq->name, name->name, name->len);
 		wq->next = sbi->queues;
 		sbi->queues = wq;
+		init_waitqueue_head(&wq->queue);
+		wq->hash = dentry->d_name.hash;
+		wq->name = name;
+		wq->len = len;
+		wq->status = -EINTR; /* Status return if interrupted */
+		atomic_set(&wq->wait_ctr, 2);
+		atomic_set(&wq->notified, 1);
+		up(&sbi->wq_sem);
+	} else {
+		atomic_inc(&wq->wait_ctr);
+		up(&sbi->wq_sem);
+		kfree(name);
+		DPRINTK(("autofs4_wait: existing wait id = 0x%08lx, name = %.*s, nfy=%d\n",
+			 (unsigned long) wq->wait_queue_token, wq->len, wq->name, notify));
+	}
+
+	if (notify != NFY_NONE && atomic_dec_and_test(&wq->notified)) {
+		int type = (notify == NFY_MOUNT ? 
+			autofs_ptype_missing : autofs_ptype_expire_multi);
+
+		DPRINTK(("autofs4_wait: new wait id = 0x%08lx, name = %.*s, nfy=%d\n",
+			(unsigned long) wq->wait_queue_token, wq->len, wq->name, notify));
 
-		DPRINTK(("autofs_wait: new wait id = 0x%08lx, name = %.*s, nfy=%d\n",
-			 wq->wait_queue_token, wq->len, wq->name, notify));
 		/* autofs4_notify_daemon() may block */
-		wq->wait_ctr = 2;
-		if (notify != NFY_NONE) {
-			autofs4_notify_daemon(sbi,wq, 
-					      notify == NFY_MOUNT ? autofs_ptype_missing :
-								    autofs_ptype_expire_multi);
-		}
-	} else {
-		wq->wait_ctr++;
-		DPRINTK(("autofs_wait: existing wait id = 0x%08lx, name = %.*s, nfy=%d\n",
-			 wq->wait_queue_token, wq->len, wq->name, notify));
+		autofs4_notify_daemon(sbi, wq, type);
 	}
 
 	/* wq->name is NULL if and only if the lock is already released */
@@ -204,19 +253,20 @@ int autofs4_wait(struct autofs_sb_info *
 		recalc_sigpending();
 		spin_unlock_irqrestore(&current->sighand->siglock, irqflags);
 
-		interruptible_sleep_on(&wq->queue);
+		wait_event_interruptible(wq->queue, wq->name == NULL);
 
 		spin_lock_irqsave(&current->sighand->siglock, irqflags);
 		current->blocked = oldset;
 		recalc_sigpending();
 		spin_unlock_irqrestore(&current->sighand->siglock, irqflags);
 	} else {
-		DPRINTK(("autofs_wait: skipped sleeping\n"));
+		DPRINTK(("autofs4_wait: skipped sleeping\n"));
 	}
 
 	status = wq->status;
 
-	if (--wq->wait_ctr == 0)	/* Are we the last process to need status? */
+	/* Are we the last process to need status? */
+	if (atomic_dec_and_test(&wq->wait_ctr))
 		kfree(wq);
 
 	return status;
@@ -227,23 +277,28 @@ int autofs4_wait_release(struct autofs_s
 {
 	struct autofs_wait_queue *wq, **wql;
 
+	down(&sbi->wq_sem);
 	for ( wql = &sbi->queues ; (wq = *wql) ; wql = &wq->next ) {
 		if ( wq->wait_queue_token == wait_queue_token )
 			break;
 	}
-	if ( !wq )
+
+	if ( !wq ) {
+		up(&sbi->wq_sem);
 		return -EINVAL;
+	}
 
 	*wql = wq->next;	/* Unlink from chain */
+	up(&sbi->wq_sem);
 	kfree(wq->name);
 	wq->name = NULL;	/* Do not wait on this queue */
 
 	wq->status = status;
 
-	if (--wq->wait_ctr == 0)	/* Is anyone still waiting for this guy? */
+	if (atomic_dec_and_test(&wq->wait_ctr))	/* Is anyone still waiting for this guy? */
 		kfree(wq);
 	else
-		wake_up(&wq->queue);
+		wake_up_interruptible(&wq->queue);
 
 	return 0;
 }
diff -Nurp linux-2.6.0.orig/fs/namespace.c linux-2.6.0/fs/namespace.c
--- linux-2.6.0.orig/fs/namespace.c	2003-12-18 10:59:05.000000000 +0800
+++ linux-2.6.0/fs/namespace.c	2005-04-04 22:28:36.000000000 +0800
@@ -251,7 +251,65 @@ struct seq_operations mounts_op = {
 	.show	= show_vfsmnt
 };
 
-/*
+/**
+ * may_umount_tree - check if a mount tree is busy
+ * @mnt: root of mount tree
+ *
+ * This is called to check if a tree of mounts has any
+ * open files, pwds, chroots or sub mounts that are
+ * busy.
+ */
+int may_umount_tree(struct vfsmount *mnt)
+{
+	struct list_head *next;
+	struct vfsmount *this_parent = mnt;
+	int actual_refs;
+	int minimum_refs;
+
+	spin_lock(&vfsmount_lock);
+	actual_refs = atomic_read(&mnt->mnt_count);
+	minimum_refs = 2;
+repeat:
+	next = this_parent->mnt_mounts.next;
+resume:
+	while (next != &this_parent->mnt_mounts) {
+		struct vfsmount *p = list_entry(next, struct vfsmount, mnt_child);
+
+		next = next->next;
+
+		actual_refs += atomic_read(&p->mnt_count);
+		minimum_refs += 2;
+
+		if (!list_empty(&p->mnt_mounts)) {
+			this_parent = p;
+			goto repeat;
+		}
+	}
+
+	if (this_parent != mnt) {
+		next = this_parent->mnt_child.next;
+		this_parent = this_parent->mnt_parent;
+		goto resume;
+	}
+	spin_unlock(&vfsmount_lock);
+
+	if (actual_refs > minimum_refs)
+		return -EBUSY;
+
+	return 0;
+}
+
+EXPORT_SYMBOL(may_umount_tree);
+
+/**
+ * may_umount - check if a mount point is busy
+ * @mnt: root of mount
+ *
+ * This is called to check if a mount point has any
+ * open files, pwds, chroots or sub mounts. If the
+ * mount has sub mounts this will return busy
+ * regardless of whether the sub mounts are busy.
+ *
  * Doesn't take quota and stuff into account. IOW, in some cases it will
  * give false negatives. The main reason why it's here is that we need
  * a non-destructive way to look for easily umountable filesystems.
diff -Nurp linux-2.6.0.orig/include/linux/auto_fs4.h linux-2.6.0/include/linux/auto_fs4.h
--- linux-2.6.0.orig/include/linux/auto_fs4.h	2003-12-18 10:58:07.000000000 +0800
+++ linux-2.6.0/include/linux/auto_fs4.h	2005-04-04 22:38:08.000000000 +0800
@@ -23,6 +23,12 @@
 #define AUTOFS_MIN_PROTO_VERSION	3
 #define AUTOFS_MAX_PROTO_VERSION	4
 
+#define AUTOFS_PROTO_SUBVERSION		6
+
+/* Mask for expire behaviour */
+#define AUTOFS_EXP_IMMEDIATE		1
+#define AUTOFS_EXP_LEAVES		2
+
 /* New message type */
 #define autofs_ptype_expire_multi	2	/* Expire entry (umount request) */
 
@@ -41,7 +47,11 @@ union autofs_packet_union {
 	struct autofs_packet_expire_multi expire_multi;
 };
 
-#define AUTOFS_IOC_EXPIRE_MULTI _IOW(0x93,0x66,int)
+#define AUTOFS_IOC_EXPIRE_MULTI		_IOW(0x93,0x66,int)
+#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)
 
 
 #endif /* _LINUX_AUTO_FS4_H */
diff -Nurp linux-2.6.0.orig/include/linux/compat_ioctl.h linux-2.6.0/include/linux/compat_ioctl.h
--- linux-2.6.0.orig/include/linux/compat_ioctl.h	2003-12-18 10:59:43.000000000 +0800
+++ linux-2.6.0/include/linux/compat_ioctl.h	2005-04-04 22:28:36.000000000 +0800
@@ -550,6 +550,10 @@ COMPATIBLE_IOCTL(AUTOFS_IOC_CATATONIC)
 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)
 /* DEVFS */
 COMPATIBLE_IOCTL(DEVFSDIOC_GET_PROTO_REV)
 COMPATIBLE_IOCTL(DEVFSDIOC_SET_EVENT_MASK)
diff -Nurp linux-2.6.0.orig/include/linux/fs.h linux-2.6.0/include/linux/fs.h
--- linux-2.6.0.orig/include/linux/fs.h	2003-12-18 10:58:29.000000000 +0800
+++ linux-2.6.0/include/linux/fs.h	2005-04-04 22:28:36.000000000 +0800
@@ -1042,6 +1042,7 @@ struct super_block *get_sb_pseudo(struct
 extern int register_filesystem(struct file_system_type *);
 extern int unregister_filesystem(struct file_system_type *);
 extern struct vfsmount *kern_mount(struct file_system_type *);
+extern int may_umount_tree(struct vfsmount *);
 extern int may_umount(struct vfsmount *);
 extern long do_mount(char *, char *, char *, unsigned long, void *);