inotify, the greatest thing since plastic

Signed-Off-By: Robert Love <rml@novell.com>

 drivers/char/Kconfig    |   13 
 drivers/char/Makefile   |    1 
 drivers/char/inotify.c  | 1068 ++++++++++++++++++++++++++++++++++++++++++++++++
 fs/attr.c               |   31 +
 fs/inode.c              |    3 
 fs/namei.c              |   21 
 fs/open.c               |    5 
 fs/read_write.c         |   17 
 fs/super.c              |    2 
 include/linux/fs.h      |    6 
 include/linux/inotify.h |  118 +++++
 11 files changed, 1279 insertions(+), 6 deletions(-)

diff -urN linux-2.6.9-rc2/drivers/char/inotify.c linux/drivers/char/inotify.c
--- linux-2.6.9-rc2/drivers/char/inotify.c	1969-12-31 19:00:00.000000000 -0500
+++ linux/drivers/char/inotify.c	2004-09-27 16:34:58.269173792 -0400
@@ -0,0 +1,1068 @@
+/*
+ * Inode based directory notifications for Linux.
+ *
+ * Copyright (C) 2004 John McCutchan
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2, or (at your option) any
+ * later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ */
+
+/* TODO: 
+ * rename inotify_watcher to inotify_watch
+ * need a way to connect MOVED_TO/MOVED_FROM events in user space
+ * use b-tree so looking up watch by WD is faster
+ */
+
+#include <linux/bitops.h>
+#include <linux/bitmap.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/namei.h>
+#include <linux/poll.h>
+#include <linux/miscdevice.h>
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/stddef.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/writeback.h>
+#include <linux/inotify.h>
+
+#define MAX_INOTIFY_DEVS	  8	/* max open inotify devices */
+#define MAX_INOTIFY_DEV_WATCHERS  8192	/* max total watches */
+#define MAX_INOTIFY_QUEUED_EVENTS 256	/* max events queued on the dev*/
+
+static atomic_t watcher_count;
+static kmem_cache_t *watcher_cache;
+static kmem_cache_t *kevent_cache;
+
+/* For debugging */
+static int event_object_count;
+static int watcher_object_count;
+static int inode_ref_count;
+static int inotify_debug_flags;
+#define iprintk(f, str...) if (inotify_debug_flags & f) printk (KERN_ALERT str)
+
+/*
+ * struct inotify_device - represents an open instance of an inotify device
+ *
+ * For each inotify device, we need to keep track of the events queued on it,
+ * a list of the inodes that we are watching, and so on.
+ *
+ * 'bitmask' holds one bit for each possible watcher descriptor: a set bit
+ * implies that the given WD is valid, unset implies it is not.
+ */
+struct inotify_device {
+	DECLARE_BITMAP(bitmask, MAX_INOTIFY_DEV_WATCHERS);
+	struct timer_list	timer;
+	wait_queue_head_t 	wait;
+	struct list_head 	events;
+	struct list_head 	watchers;
+	spinlock_t		lock;
+	unsigned int		event_count;
+	int			nr_watches;
+};
+
+struct inotify_watcher {
+	int 			wd; // watcher descriptor
+	unsigned long		mask;
+	struct inode *		inode;
+	struct inotify_device *	dev;
+	struct list_head	d_list; // device list
+	struct list_head	i_list; // inode list
+	struct list_head	u_list; // unmount list 
+};
+#define inotify_watcher_d_list(pos) list_entry((pos), struct inotify_watcher, d_list)
+#define inotify_watcher_i_list(pos) list_entry((pos), struct inotify_watcher, i_list)
+#define inotify_watcher_u_list(pos) list_entry((pos), struct inotify_watcher, u_list)
+
+/*
+ * A list of these is attached to each instance of the driver
+ * when the drivers read() gets called, this list is walked and
+ * all events that can fit in the buffer get delivered
+ */
+struct inotify_kernel_event {
+        struct list_head        list;
+	struct inotify_event	event;
+};
+#define list_to_inotify_kernel_event(pos) list_entry((pos), struct inotify_kernel_event, list)
+
+/*
+ * find_inode - resolve a user-given path to a specific inode and iget() it
+ */
+static struct inode * find_inode(const char __user *dirname)
+{
+	struct inode *inode;
+	struct nameidata nd;
+	int error;
+
+	error = __user_walk(dirname, LOOKUP_FOLLOW, &nd);
+	if (error) {
+		iprintk(INOTIFY_DEBUG_INODE, "could not find inode\n");
+		inode = ERR_PTR(error);
+		goto out;
+	}
+
+	inode = nd.dentry->d_inode;
+	__iget(inode);
+	iprintk(INOTIFY_DEBUG_INODE, "ref'd inode\n");
+	inode_ref_count++;
+	path_release(&nd);
+out:
+	return inode;
+}
+
+static void unref_inode(struct inode *inode)
+{
+	inode_ref_count--;
+	iprintk(INOTIFY_DEBUG_INODE, "unref'd inode\n");
+	iput(inode);
+}
+
+struct inotify_kernel_event *kernel_event(int wd, int mask,
+					  const char *filename)
+{
+	struct inotify_kernel_event *kevent;
+
+	kevent = kmem_cache_alloc(kevent_cache, GFP_ATOMIC);
+	if (!kevent) {
+		iprintk(INOTIFY_DEBUG_ALLOC,
+			"failed to alloc kevent (%d,%d)\n", wd, mask);
+		goto out;
+	}
+
+	iprintk(INOTIFY_DEBUG_ALLOC, "alloced kevent %p (%d,%d)\n",
+		kevent, wd, mask);
+
+	kevent->event.wd = wd;
+	kevent->event.mask = mask;
+	INIT_LIST_HEAD(&kevent->list);
+
+	if (filename) {
+		iprintk(INOTIFY_DEBUG_FILEN,
+			"filename for event was %p %s\n", filename, filename);
+		strncpy(kevent->event.filename, filename,
+			INOTIFY_FILENAME_MAX);
+		kevent->event.filename[INOTIFY_FILENAME_MAX-1] = '\0';
+		iprintk(INOTIFY_DEBUG_FILEN,
+			"filename after copying %s\n", kevent->event.filename);
+	} else {
+		iprintk(INOTIFY_DEBUG_FILEN, "no filename for event\n");
+		kevent->event.filename[0] = '\0';
+	}
+	
+	event_object_count++;
+
+out:
+	return kevent;
+}
+
+void delete_kernel_event(struct inotify_kernel_event *kevent)
+{
+	if (!kevent)
+		return;
+
+	event_object_count--;
+	INIT_LIST_HEAD(&kevent->list);
+	kevent->event.wd = -1;
+	kevent->event.mask = 0;
+
+	iprintk(INOTIFY_DEBUG_ALLOC, "free'd kevent %p\n", kevent);
+	kmem_cache_free(kevent_cache, kevent);
+}
+
+#define inotify_dev_has_events(dev) (!list_empty(&dev->events))
+#define inotify_dev_get_event(dev) (list_to_inotify_kernel_event(dev->events.next))
+/* Does this events mask get sent to the watcher ? */
+#define event_and(event_mask,watchers_mask) 	((event_mask == IN_UNMOUNT) || \
+						(event_mask == IN_IGNORED) || \
+						(event_mask & watchers_mask))
+
+/*
+ * inotify_dev_queue_event - add a new event to the given device
+ *
+ * Caller must hold dev->lock.
+ */
+static void inotify_dev_queue_event(struct inotify_device *dev,
+				    struct inotify_watcher *watcher, int mask,
+				    const char *filename)
+{
+	struct inotify_kernel_event *kevent;
+
+	/*
+	 * Check if the new event is a duplicate of the last event queued.
+	 */
+	if (dev->event_count && 
+		inotify_dev_get_event(dev)->event.mask == mask &&
+		inotify_dev_get_event(dev)->event.wd == watcher->wd) {
+
+		/* Check if the filenames match */
+		if (!filename && inotify_dev_get_event(dev)->event.filename[0] == '\0')
+			return;
+		if (filename && !strcmp(inotify_dev_get_event(dev)->event.filename, filename))
+			return;
+	}
+	/*
+	 * the queue has already overflowed and we have already sent the
+	 * Q_OVERFLOW event
+	 */
+	if (dev->event_count > MAX_INOTIFY_QUEUED_EVENTS) {
+		iprintk(INOTIFY_DEBUG_EVENTS,
+			"event queue for %p overflowed\n", dev);
+		return;
+	}
+
+	/* the queue has just overflowed and we need to notify user space */
+	if (dev->event_count == MAX_INOTIFY_QUEUED_EVENTS) {
+		dev->event_count++;
+		kevent = kernel_event(-1, IN_Q_OVERFLOW, NULL);
+		iprintk(INOTIFY_DEBUG_EVENTS, "sending IN_Q_OVERFLOW to %p\n",
+			dev);
+		goto add_event_to_queue;
+	}
+
+	if (!event_and(mask, watcher->inode->watchers_mask) ||
+			!event_and(mask, watcher->mask))
+		return;
+
+	dev->event_count++;
+	kevent = kernel_event(watcher->wd, mask, filename);
+
+add_event_to_queue:
+	if (!kevent) {
+		iprintk(INOTIFY_DEBUG_EVENTS, "failed to queue event for %p"
+			" -- could not allocate kevent\n", dev);
+		dev->event_count--;
+		return;
+	}
+
+	list_add_tail(&kevent->list, &dev->events);
+	iprintk(INOTIFY_DEBUG_EVENTS,
+		"queued event %x for %p\n", kevent->event.mask, dev);
+}
+
+/*
+ * inotify_dev_event_dequeue - destroy an event on the given device
+ *
+ * Caller must hold dev->lock.
+ */
+static void inotify_dev_event_dequeue(struct inotify_device *dev)
+{
+	struct inotify_kernel_event *kevent;
+
+	if (!inotify_dev_has_events(dev))
+		return;
+
+	kevent = inotify_dev_get_event(dev);
+	list_del(&kevent->list);
+	dev->event_count--;
+	delete_kernel_event(kevent);
+
+	iprintk(INOTIFY_DEBUG_EVENTS, "dequeued event on %p\n", dev);
+}
+
+/*
+ * inotify_dev_get_wd - returns the next WD for use by the given dev
+ *
+ * Caller must hold dev->lock before calling.
+ */
+static int inotify_dev_get_wd(struct inotify_device *dev)
+{
+	int wd;
+
+	if (!dev || dev->nr_watches == MAX_INOTIFY_DEV_WATCHERS)
+		return -1;
+
+	dev->nr_watches++;
+	wd = find_first_zero_bit(dev->bitmask, MAX_INOTIFY_DEV_WATCHERS);
+	set_bit(wd, dev->bitmask);
+
+	return wd;
+}
+
+/*
+ * inotify_dev_put_wd - release the given WD on the given device
+ *
+ * Caller must hold dev->lock.
+ */
+static int inotify_dev_put_wd(struct inotify_device *dev, int wd)
+{
+	if (!dev || wd < 0)
+		return -1;
+
+	dev->nr_watches--;
+	clear_bit(wd, dev->bitmask);
+
+	return 0;
+}
+
+/*
+ * create_watcher - creates a watcher on the given device.
+ *
+ * Grabs dev->lock, so the caller must not hold it.
+ */
+static struct inotify_watcher *create_watcher(struct inotify_device *dev,
+					      int mask, struct inode *inode)
+{
+	struct inotify_watcher *watcher;
+
+	watcher = kmem_cache_alloc(watcher_cache, GFP_KERNEL);
+	if (!watcher) {
+		iprintk(INOTIFY_DEBUG_ALLOC,
+			"failed to allocate watcher (%p,%d)\n", inode, mask);
+		return NULL;
+	}
+
+	watcher->wd = -1;
+	watcher->mask = mask;
+	watcher->inode = inode;
+	watcher->dev = dev;
+	INIT_LIST_HEAD(&watcher->d_list);
+	INIT_LIST_HEAD(&watcher->i_list);
+	INIT_LIST_HEAD(&watcher->u_list);
+
+	spin_lock(&dev->lock);
+	watcher->wd = inotify_dev_get_wd(dev);
+	spin_unlock(&dev->lock);
+
+	if (watcher->wd < 0) {
+		iprintk(INOTIFY_DEBUG_ERRORS,
+			"Could not get wd for watcher %p\n", watcher);
+		iprintk(INOTIFY_DEBUG_ALLOC, "free'd watcher %p\n", watcher);
+		kmem_cache_free(watcher_cache, watcher);
+		return NULL;
+	}
+
+	watcher_object_count++;
+	return watcher;
+}
+
+/*
+ * delete_watcher - removes the given 'watcher' from the given 'dev'
+ *
+ * Caller must hold dev->lock.
+ */
+static void delete_watcher(struct inotify_device *dev,
+			   struct inotify_watcher *watcher)
+{
+	inotify_dev_put_wd(dev, watcher->wd);
+	iprintk(INOTIFY_DEBUG_ALLOC, "free'd watcher %p\n", watcher);
+	kmem_cache_free(watcher_cache, watcher);
+	watcher_object_count--;
+}
+
+/*
+ * inotify_find_dev - find the watcher associated with the given inode and dev
+ *
+ * Caller must hold dev->lock.
+ */
+static struct inotify_watcher *inode_find_dev(struct inode *inode,
+					      struct inotify_device *dev)
+{
+	struct inotify_watcher *watcher;
+
+	list_for_each_entry(watcher, &inode->watchers, i_list) {
+		if (watcher->dev == dev)
+			return watcher;
+	}
+
+	return NULL;
+}
+
+static struct inotify_watcher *dev_find_wd(struct inotify_device *dev, int wd)
+{
+	struct inotify_watcher *watcher;
+
+	list_for_each_entry(watcher, &dev->watchers, d_list) {
+		if (watcher->wd == wd)
+			return watcher;
+	}
+	return NULL;
+}
+
+static int inotify_dev_is_watching_inode(struct inotify_device *dev,
+					  struct inode *inode)
+{
+	struct inotify_watcher *watcher;
+
+	list_for_each_entry(watcher, &dev->watchers, d_list) {
+		if (watcher->inode == inode)
+			return 1;
+	}
+	
+	return 0;
+}
+
+static int inotify_dev_add_watcher(struct inotify_device *dev,
+				   struct inotify_watcher *watcher)
+{
+	int error;
+
+	error = 0;
+
+	if (!dev || !watcher) {
+		error = -EINVAL;
+		goto out;
+	}
+
+	if (dev_find_wd (dev, watcher->wd)) {
+		error = -EINVAL;
+		goto out;
+	}
+
+	if (dev->nr_watches == MAX_INOTIFY_DEV_WATCHERS) {
+		error = -ENOSPC;
+		goto out;
+	}
+
+	list_add(&watcher->d_list, &dev->watchers);
+out:
+	return error;
+}
+
+/*
+ * inotify_dev_rm_watcher - remove the given watch from the given device
+ *
+ * Caller must hold dev->lock because we call inotify_dev_queue_event().
+ */
+static int inotify_dev_rm_watcher(struct inotify_device *dev,
+				  struct inotify_watcher *watcher)
+{
+	int error;
+
+	error = -EINVAL;
+	if (watcher) {
+		inotify_dev_queue_event(dev, watcher, IN_IGNORED, NULL);
+		list_del(&watcher->d_list);
+		error = 0;
+	} 
+
+	return error;
+}
+
+void inode_update_watchers_mask(struct inode *inode)
+{
+	struct inotify_watcher *watcher;
+	unsigned long new_mask;
+
+	new_mask = 0;
+	list_for_each_entry(watcher, &inode->watchers, i_list)
+		new_mask |= watcher->mask;
+
+	inode->watchers_mask = new_mask;
+}
+
+/*
+ * inode_add_watcher - add a watcher to the given inode
+ *
+ * Callers must hold dev->lock, because we call inode_find_dev().
+ */
+static int inode_add_watcher(struct inode *inode,
+			     struct inotify_watcher *watcher)
+{
+	if (!inode || !watcher || inode_find_dev(inode, watcher->dev))
+		return -EINVAL;
+
+	list_add(&watcher->i_list, &inode->watchers);
+	inode->watcher_count++;
+	inode_update_watchers_mask(inode);
+
+	return 0;
+}
+
+static int inode_rm_watcher(struct inode *inode,
+			     struct inotify_watcher *watcher)
+{
+	if (!inode || !watcher)
+		return -EINVAL;
+
+	list_del(&watcher->i_list);
+	inode->watcher_count--;
+
+	inode_update_watchers_mask(inode);
+
+	return 0;
+}
+
+/* Kernel API */
+
+void inotify_inode_queue_event(struct inode *inode, unsigned long mask,
+			       const char *filename)
+{
+	struct inotify_watcher *watcher;
+
+	spin_lock(&inode->i_lock);
+
+	list_for_each_entry(watcher, &inode->watchers, i_list) {
+		spin_lock(&watcher->dev->lock);
+		inotify_dev_queue_event(watcher->dev, watcher, mask, filename);
+		spin_unlock(&watcher->dev->lock);
+	}
+
+	spin_unlock(&inode->i_lock);
+}
+EXPORT_SYMBOL_GPL(inotify_inode_queue_event);
+
+void inotify_inode_queue_event_pair(struct inode *inode1, unsigned long mask1,
+				    const char *filename1,
+				    struct inode *inode2, unsigned long mask2,
+				    const char *filename2)
+{
+	struct inotify_watcher *watcher;
+
+	spin_lock(&inode1->i_lock);
+	spin_lock(&inode2->i_lock);
+
+	list_for_each_entry(watcher, &inode1->watchers, i_list) {
+		spin_lock(&watcher->dev->lock);
+		inotify_dev_queue_event(watcher->dev, watcher,
+					mask1, filename1);
+		spin_unlock(&watcher->dev->lock);
+	}
+
+	list_for_each_entry(watcher, &inode2->watchers, i_list) {
+		spin_lock(&watcher->dev->lock);
+		inotify_dev_queue_event(watcher->dev, watcher,
+					mask2, filename2);
+		spin_unlock(&watcher->dev->lock);
+	}
+
+	spin_unlock(&inode2->i_lock);
+	spin_unlock(&inode1->i_lock);
+}
+EXPORT_SYMBOL_GPL(inotify_inode_queue_event_pair);
+
+void inotify_dentry_parent_queue_event(struct dentry *dentry,
+				       unsigned long mask,
+				       const char *filename)
+{
+	struct dentry *parent;
+
+	spin_lock(&dentry->d_lock);
+	dget(dentry->d_parent);
+	parent = dentry->d_parent;
+	inotify_inode_queue_event(parent->d_inode, mask, filename);
+	dput(parent);
+	spin_unlock(&dentry->d_lock);
+}
+EXPORT_SYMBOL_GPL(inotify_dentry_parent_queue_event);
+
+static void ignore_helper(struct inotify_watcher *watcher, int event)
+{
+	struct inotify_device *dev;
+	struct inode *inode;
+
+	spin_lock(&watcher->dev->lock);
+	spin_lock(&watcher->inode->i_lock);
+
+	inode = watcher->inode;
+	dev = watcher->dev;
+
+	if (event)
+		inotify_dev_queue_event(dev, watcher, event, NULL);
+
+	inode_rm_watcher(inode, watcher);
+	inotify_dev_rm_watcher(watcher->dev, watcher);
+	list_del(&watcher->u_list);
+
+	spin_unlock(&inode->i_lock);
+	delete_watcher(dev, watcher);
+	spin_unlock(&dev->lock);
+
+	unref_inode(inode);
+}
+
+static void process_umount_list(struct list_head *umount) {
+	struct inotify_watcher *watcher, *next;
+
+	list_for_each_entry_safe(watcher, next, umount, u_list)
+		ignore_helper(watcher, IN_UNMOUNT);
+}
+
+static void build_umount_list(struct list_head *head, struct super_block *sb,
+			       struct list_head *umount)
+{
+	struct inode *	inode;
+
+	list_for_each_entry(inode, head, i_list) {
+		struct inotify_watcher *watcher;
+
+		if (inode->i_sb != sb)
+			continue;
+
+		spin_lock(&inode->i_lock);
+
+		list_for_each_entry(watcher, &inode->watchers, i_list)
+			list_add(&watcher->u_list, umount);
+
+		spin_unlock(&inode->i_lock);
+	}
+}
+
+void inotify_super_block_umount(struct super_block *sb)
+{
+	struct list_head umount;
+
+	INIT_LIST_HEAD(&umount);
+
+	spin_lock(&inode_lock);
+	build_umount_list(&inode_in_use, sb, &umount);
+	spin_unlock(&inode_lock);
+
+	process_umount_list(&umount);
+}
+EXPORT_SYMBOL_GPL(inotify_super_block_umount);
+
+void inotify_inode_is_dead(struct inode *inode)
+{
+	struct inotify_watcher *watcher, *next;
+
+	list_for_each_entry_safe(watcher, next, &inode->watchers, i_list)
+		ignore_helper(watcher, 0);
+}
+EXPORT_SYMBOL_GPL(inotify_inode_is_dead);
+
+/* The driver interface is implemented below */
+
+static unsigned int inotify_poll(struct file *file, poll_table *wait)
+{
+        struct inotify_device *dev;
+
+        dev = file->private_data;
+
+        poll_wait(file, &dev->wait, wait);
+
+        if (inotify_dev_has_events(dev))
+                return POLLIN | POLLRDNORM;
+
+        return 0;
+}
+
+#define MAX_EVENTS_AT_ONCE 20
+static ssize_t inotify_read(struct file *file, __user char *buf,
+			    size_t count, loff_t *pos)
+{
+	size_t out;
+	struct inotify_event *eventbuf;
+	struct inotify_kernel_event *kevent;
+	struct inotify_device *dev;
+	char *obuf;
+	int err;
+	int events;
+	int event_count;
+
+	DECLARE_WAITQUEUE(wait, current);
+
+	out = -ENOMEM;
+	eventbuf = kmalloc(sizeof(struct inotify_event) * MAX_EVENTS_AT_ONCE, 
+			   GFP_KERNEL);
+	if (!eventbuf)
+		goto out;
+
+	events = 0;
+	out = 0;
+	err = 0;
+	obuf = buf;
+
+	dev = file->private_data;
+
+	/* We only hand out full inotify events */
+	if (count < sizeof(struct inotify_event)) {
+		out = -EINVAL;
+		goto out;
+	}
+
+	events = count / sizeof(struct inotify_event);
+	if (events > MAX_EVENTS_AT_ONCE)
+		events = MAX_EVENTS_AT_ONCE;
+
+	if (!inotify_dev_has_events(dev)) {
+		if (file->f_flags & O_NONBLOCK) {
+			out = -EAGAIN;
+			goto out;
+		}
+	}
+
+	spin_lock(&dev->lock);
+
+	add_wait_queue(&dev->wait, &wait);
+repeat:
+	if (signal_pending(current)) {
+		spin_unlock(&dev->lock);
+		out = -ERESTARTSYS;
+		set_current_state(TASK_RUNNING);
+		remove_wait_queue(&dev->wait, &wait);
+		goto out;
+	}
+	set_current_state(TASK_INTERRUPTIBLE);
+	if (!inotify_dev_has_events(dev)) {
+		spin_unlock(&dev->lock);
+		schedule();
+		spin_lock(&dev->lock);
+		goto repeat;
+	}
+
+	set_current_state(TASK_RUNNING);
+	remove_wait_queue(&dev->wait, &wait);
+
+	err = !access_ok(VERIFY_WRITE, (void *)buf,
+			 sizeof(struct inotify_event));
+
+	if (err) {
+		out = -EFAULT;
+		goto out;
+	}
+
+	/* Copy all the events we can to the event buffer */
+	for (event_count = 0; event_count < events; event_count++) {
+		kevent = inotify_dev_get_event(dev);
+		eventbuf[event_count] = kevent->event;
+		inotify_dev_event_dequeue(dev);
+	}
+
+	spin_unlock(&dev->lock);
+
+	/* Send the event buffer to user space */
+	err = copy_to_user(buf, eventbuf,
+			   events * sizeof(struct inotify_event));
+
+	buf += sizeof(struct inotify_event) * events;
+
+	out = buf - obuf;
+
+out:
+	kfree(eventbuf);
+	return out;
+}
+
+static void inotify_dev_timer(unsigned long data)
+{
+	struct inotify_device *dev;
+
+	if (!data)
+		return;
+	dev = (struct inotify_device *) data;
+
+	/* reset the timer */
+	mod_timer(&dev->timer, jiffies + (HZ/4));
+
+	/* wake up anyone blocked on the device */
+	if (inotify_dev_has_events(dev))
+		wake_up_interruptible(&dev->wait);
+}
+
+static int inotify_open(struct inode *inode, struct file *file)
+{
+	struct inotify_device *dev;
+
+	if (atomic_read(&watcher_count) == MAX_INOTIFY_DEVS)
+		return -ENODEV;
+
+	atomic_inc(&watcher_count);
+
+	dev = kmalloc(sizeof(struct inotify_device), GFP_KERNEL);
+	if (!dev)
+		return -ENOMEM;
+
+	bitmap_zero(dev->bitmask, MAX_INOTIFY_DEV_WATCHERS);
+
+	INIT_LIST_HEAD(&dev->events);
+	INIT_LIST_HEAD(&dev->watchers);
+	init_timer(&dev->timer);
+	init_waitqueue_head(&dev->wait);
+
+	dev->event_count = 0;
+	dev->nr_watches = 0;
+	dev->lock = SPIN_LOCK_UNLOCKED;
+
+	file->private_data = dev;
+
+	dev->timer.data = (unsigned long) dev;
+	dev->timer.function = inotify_dev_timer;
+	dev->timer.expires = jiffies + (HZ/4);
+
+	add_timer(&dev->timer);
+
+	printk(KERN_ALERT "inotify device opened\n");
+
+	return 0;
+}
+
+static void inotify_release_all_watchers(struct inotify_device *dev)
+{
+	struct inotify_watcher *watcher,*next;
+
+	list_for_each_entry_safe(watcher, next, &dev->watchers, d_list)
+		ignore_helper(watcher, 0);
+}
+
+/*
+ * inotify_release_all_events - destroy all of the events on a given device
+ */
+static void inotify_release_all_events(struct inotify_device *dev)
+{
+	spin_lock(&dev->lock);
+	while (inotify_dev_has_events(dev))
+		inotify_dev_event_dequeue(dev);
+	spin_unlock(&dev->lock);
+}
+
+
+static int inotify_release(struct inode *inode, struct file *file)
+{
+	struct inotify_device *dev;
+
+	dev = file->private_data;
+	del_timer_sync(&dev->timer);
+	inotify_release_all_watchers(dev);
+	inotify_release_all_events(dev);
+	kfree(dev);
+
+	printk(KERN_ALERT "inotify device released\n");
+
+	atomic_dec(&watcher_count);
+	return 0;
+}
+
+static int inotify_watch(struct inotify_device *dev,
+			 struct inotify_watch_request *request)
+{
+	int err;
+	struct inode *inode;
+	struct inotify_watcher *watcher;
+	err = 0;
+
+	inode = find_inode(request->dirname);
+	if (IS_ERR(inode)) {
+		err = PTR_ERR(inode);
+		goto exit;
+	}
+
+	if (!S_ISDIR(inode->i_mode))
+		iprintk(INOTIFY_DEBUG_ERRORS, "watching file\n");
+
+	spin_lock(&dev->lock);
+	spin_lock(&inode->i_lock);
+
+	/*
+	 * This handles the case of re-adding a directory we are already
+	 * watching, we just update the mask and return 0
+	 */
+	if (inotify_dev_is_watching_inode(dev, inode)) {
+		struct inotify_watcher *owatcher;	/* the old watcher */
+
+		iprintk(INOTIFY_DEBUG_ERRORS,
+				"adjusting event mask for inode %p\n", inode);
+
+		owatcher = inode_find_dev(inode, dev);
+		owatcher->mask = request->mask;
+		inode_update_watchers_mask(inode);
+		spin_unlock(&inode->i_lock);
+		spin_unlock(&dev->lock);
+		unref_inode(inode);
+
+		return 0;
+	}
+
+	spin_unlock(&inode->i_lock);
+	spin_unlock(&dev->lock);
+
+	watcher = create_watcher(dev, request->mask, inode);
+	if (!watcher) {
+		unref_inode(inode);
+		return -ENOSPC;
+	}
+
+	spin_lock(&dev->lock);
+	spin_lock(&inode->i_lock);
+
+	/* We can't add anymore watchers to this device */
+	if (inotify_dev_add_watcher(dev, watcher) == -ENOSPC) {
+		iprintk(INOTIFY_DEBUG_ERRORS,
+			"can't add watcher dev is full\n");
+		spin_unlock(&inode->i_lock);
+		delete_watcher(dev, watcher);
+		spin_unlock(&dev->lock);
+
+		unref_inode(inode);
+		return -ENOSPC;
+	}
+
+	inode_add_watcher(inode, watcher);
+
+	/* we keep a reference on the inode */
+	if (!err)
+		err = watcher->wd;
+
+	spin_unlock(&inode->i_lock);
+	spin_unlock(&dev->lock);
+exit:
+	return err;
+}
+
+static int inotify_ignore(struct inotify_device *dev, int wd)
+{
+	struct inotify_watcher *watcher;
+
+	watcher = dev_find_wd(dev, wd);
+	if (!watcher)
+		return -EINVAL;
+	ignore_helper(watcher, 0);
+
+	return 0;
+}
+
+static void inotify_print_stats(struct inotify_device *dev)
+{
+	int sizeof_inotify_watcher;
+	int sizeof_inotify_device;
+	int sizeof_inotify_kernel_event;
+
+	sizeof_inotify_watcher = sizeof (struct inotify_watcher);
+	sizeof_inotify_device = sizeof (struct inotify_device);
+	sizeof_inotify_kernel_event = sizeof (struct inotify_kernel_event);
+
+	printk(KERN_ALERT "GLOBAL INOTIFY STATS\n");
+	printk(KERN_ALERT "watcher_count = %d\n", atomic_read(&watcher_count));
+	printk(KERN_ALERT "event_object_count = %d\n", event_object_count);
+	printk(KERN_ALERT "watcher_object_count = %d\n", watcher_object_count);
+	printk(KERN_ALERT "inode_ref_count = %d\n", inode_ref_count);
+
+	printk(KERN_ALERT "sizeof(struct inotify_watcher) = %d\n",
+		sizeof_inotify_watcher);
+	printk(KERN_ALERT "sizeof(struct inotify_device) = %d\n",
+		sizeof_inotify_device);
+	printk(KERN_ALERT "sizeof(struct inotify_kernel_event) = %d\n",
+		sizeof_inotify_kernel_event);
+
+	spin_lock(&dev->lock);
+
+	printk(KERN_ALERT "inotify device: %p\n", dev);
+	printk(KERN_ALERT "inotify event_count: %u\n", dev->event_count);
+	printk(KERN_ALERT "inotify watch_count: %d\n", dev->nr_watches);
+
+	spin_unlock(&dev->lock);
+}
+
+static int inotify_ioctl(struct inode *ip, struct file *fp,
+			 unsigned int cmd, unsigned long arg)
+{
+	int err;
+	struct inotify_device *dev;
+	struct inotify_watch_request request;
+	int wd;
+
+	dev = fp->private_data;
+	err = 0;
+
+	if (_IOC_TYPE(cmd) != INOTIFY_IOCTL_MAGIC)
+		return -EINVAL;
+	if (_IOC_NR(cmd) > INOTIFY_IOCTL_MAXNR)
+		return -EINVAL;
+
+	if (_IOC_DIR(cmd) & _IOC_READ)
+		err = !access_ok(VERIFY_READ, (void *) arg, _IOC_SIZE(cmd));
+
+	if (err)
+		err = -EFAULT;
+		goto out;
+
+	if (_IOC_DIR(cmd) & _IOC_WRITE)
+		err = !access_ok(VERIFY_WRITE, (void *)arg, _IOC_SIZE(cmd));
+
+	if (err) {
+		err = -EFAULT;
+		goto out;
+	}
+
+	err = -EINVAL;
+
+	switch (cmd) {
+	case INOTIFY_WATCH:
+		iprintk(INOTIFY_DEBUG_ERRORS, "INOTIFY_WATCH ioctl\n");
+		if (copy_from_user(&request, (void *) arg,
+				sizeof(struct inotify_watch_request))) {
+			err = -EFAULT;
+			goto out;
+		}
+		err = inotify_watch(dev, &request);
+		break;
+	case INOTIFY_IGNORE:
+		iprintk(INOTIFY_DEBUG_ERRORS, "INOTIFY_IGNORE ioctl\n");
+		if (copy_from_user(&wd, (void *)arg, sizeof (int))) {
+			err = -EFAULT;
+			goto out;
+		}
+		err = inotify_ignore(dev, wd);
+		break;
+	case INOTIFY_STATS:
+		iprintk(INOTIFY_DEBUG_ERRORS, "INOTIFY_STATS ioctl\n");
+		inotify_print_stats(dev);
+		err = 0;
+		break;
+	case INOTIFY_SETDEBUG:
+		iprintk(INOTIFY_DEBUG_ERRORS,
+			"INOTIFY_SETDEBUG ioctl\n");
+		if (copy_from_user(&inotify_debug_flags, (void *) arg,
+				sizeof (int))) {
+			err = -EFAULT;
+			goto out;
+		}
+		break;
+	}
+
+out:
+	return err;
+}
+
+static struct file_operations inotify_fops = {
+	.owner		= THIS_MODULE,
+	.poll		= inotify_poll,
+	.read		= inotify_read,
+	.open		= inotify_open,
+	.release	= inotify_release,
+	.ioctl		= inotify_ioctl,
+};
+
+struct miscdevice inotify_device = {
+	.minor  = MISC_DYNAMIC_MINOR,
+	.name	= "inotify",
+	.fops	= &inotify_fops,
+};
+
+static int __init inotify_init(void)
+{
+	int ret;
+
+	ret = misc_register(&inotify_device);
+	if (ret)
+		goto out;
+
+	inotify_debug_flags = INOTIFY_DEBUG_NONE;
+
+	watcher_cache = kmem_cache_create("watcher_cache",
+			sizeof(struct inotify_watcher), 0, SLAB_PANIC,
+			NULL, NULL);
+
+	kevent_cache = kmem_cache_create("kevent_cache",
+			sizeof(struct inotify_kernel_event), 0,
+			SLAB_PANIC, NULL, NULL);
+
+	printk(KERN_INFO "inotify init: minor=%d\n", inotify_device.minor);
+out:
+	return ret;
+}
+
+module_init(inotify_init);
diff -urN linux-2.6.9-rc2/drivers/char/Kconfig linux/drivers/char/Kconfig
--- linux-2.6.9-rc2/drivers/char/Kconfig	2004-09-20 17:03:56.000000000 -0400
+++ linux/drivers/char/Kconfig	2004-09-27 15:41:15.704078152 -0400
@@ -62,6 +62,19 @@
 	depends on VT && !S390 && !UM
 	default y
 
+config INOTIFY
+	bool "Inotify file change notification support"
+	default y
+	---help---
+	  Say Y here to enable inotify support and the /dev/inotify character
+	  device.  Inotify is a file change notification system and a
+	  replacement for dnotify.  Inotify fixes numerous shortcomings in
+	  dnotify and introduces several new features.  It allows monitoring
+	  of both files and directories via a single open fd.  Multiple file
+	  events are supported.
+	  
+	  If unsure, say Y.
+
 config SERIAL_NONSTANDARD
 	bool "Non-standard serial port support"
 	---help---
diff -urN linux-2.6.9-rc2/drivers/char/Makefile linux/drivers/char/Makefile
--- linux-2.6.9-rc2/drivers/char/Makefile	2004-09-20 17:03:56.000000000 -0400
+++ linux/drivers/char/Makefile	2004-09-27 15:03:52.603081336 -0400
@@ -12,6 +12,7 @@
 obj-$(CONFIG_LEGACY_PTYS)	+= pty.o
 obj-$(CONFIG_UNIX98_PTYS)	+= pty.o
 obj-y				+= misc.o
+obj-$(CONFIG_INOTIFY)		+= inotify.o
 obj-$(CONFIG_VT)		+= vt_ioctl.o vc_screen.o consolemap.o \
 				   consolemap_deftbl.o selection.o keyboard.o
 obj-$(CONFIG_HW_CONSOLE)	+= vt.o defkeymap.o
diff -urN linux-2.6.9-rc2/fs/attr.c linux/fs/attr.c
--- linux-2.6.9-rc2/fs/attr.c	2004-08-14 06:54:50.000000000 -0400
+++ linux/fs/attr.c	2004-09-27 15:48:38.187810400 -0400
@@ -11,6 +11,7 @@
 #include <linux/string.h>
 #include <linux/smp_lock.h>
 #include <linux/dnotify.h>
+#include <linux/inotify.h>
 #include <linux/fcntl.h>
 #include <linux/quotaops.h>
 #include <linux/security.h>
@@ -128,6 +129,28 @@
 	return dn_mask;
 }
 
+static int setattr_mask_inotify(unsigned int ia_valid)
+{
+	unsigned long dn_mask = 0;
+
+	if (ia_valid & ATTR_UID)
+		dn_mask |= IN_ATTRIB;
+	if (ia_valid & ATTR_GID)
+		dn_mask |= IN_ATTRIB;
+	if (ia_valid & ATTR_SIZE)
+		dn_mask |= IN_MODIFY;
+	/* both times implies a utime(s) call */
+	if ((ia_valid & (ATTR_ATIME|ATTR_MTIME)) == (ATTR_ATIME|ATTR_MTIME))
+		dn_mask |= IN_ATTRIB;
+	else if (ia_valid & ATTR_ATIME)
+		dn_mask |= IN_ACCESS;
+	else if (ia_valid & ATTR_MTIME)
+		dn_mask |= IN_MODIFY;
+	if (ia_valid & ATTR_MODE)
+		dn_mask |= IN_ATTRIB;
+	return dn_mask;
+}
+
 int notify_change(struct dentry * dentry, struct iattr * attr)
 {
 	struct inode *inode = dentry->d_inode;
@@ -185,8 +208,16 @@
 	}
 	if (!error) {
 		unsigned long dn_mask = setattr_mask(ia_valid);
+		unsigned long in_mask = setattr_mask_inotify(ia_valid);
+
 		if (dn_mask)
 			dnotify_parent(dentry, dn_mask);
+		if (in_mask) {
+			inotify_inode_queue_event(dentry->d_inode, in_mask,
+						  NULL);
+			inotify_dentry_parent_queue_event(dentry, in_mask,
+							  dentry->d_name.name);
+		}
 	}
 	return error;
 }
diff -urN linux-2.6.9-rc2/fs/inode.c linux/fs/inode.c
--- linux-2.6.9-rc2/fs/inode.c	2004-09-20 17:04:00.000000000 -0400
+++ linux/fs/inode.c	2004-09-27 15:48:38.187810400 -0400
@@ -114,6 +114,9 @@
 	if (inode) {
 		struct address_space * const mapping = &inode->i_data;
 
+#ifdef CONFIG_INOTIFY
+		INIT_LIST_HEAD(&inode->watchers);
+#endif
 		inode->i_sb = sb;
 		inode->i_blkbits = sb->s_blocksize_bits;
 		inode->i_flags = 0;
diff -urN linux-2.6.9-rc2/fs/namei.c linux/fs/namei.c
--- linux-2.6.9-rc2/fs/namei.c	2004-09-20 17:04:01.000000000 -0400
+++ linux/fs/namei.c	2004-09-27 15:48:38.187810400 -0400
@@ -22,6 +22,7 @@
 #include <linux/quotaops.h>
 #include <linux/pagemap.h>
 #include <linux/dnotify.h>
+#include <linux/inotify.h>
 #include <linux/smp_lock.h>
 #include <linux/personality.h>
 #include <linux/security.h>
@@ -1226,6 +1227,7 @@
 	error = dir->i_op->create(dir, dentry, mode, nd);
 	if (!error) {
 		inode_dir_notify(dir, DN_CREATE);
+		inotify_inode_queue_event(dir, IN_CREATE_FILE, dentry->d_name.name);
 		security_inode_post_create(dir, dentry, mode);
 	}
 	return error;
@@ -1540,6 +1542,7 @@
 	error = dir->i_op->mknod(dir, dentry, mode, dev);
 	if (!error) {
 		inode_dir_notify(dir, DN_CREATE);
+		inotify_inode_queue_event(dir, IN_CREATE_FILE, dentry->d_name.name);
 		security_inode_post_mknod(dir, dentry, mode, dev);
 	}
 	return error;
@@ -1613,6 +1616,7 @@
 	error = dir->i_op->mkdir(dir, dentry, mode);
 	if (!error) {
 		inode_dir_notify(dir, DN_CREATE);
+		inotify_inode_queue_event(dir, IN_CREATE_SUBDIR, dentry->d_name.name);
 		security_inode_post_mkdir(dir,dentry, mode);
 	}
 	return error;
@@ -1708,6 +1712,9 @@
 	up(&dentry->d_inode->i_sem);
 	if (!error) {
 		inode_dir_notify(dir, DN_DELETE);
+		inotify_inode_queue_event(dir, IN_DELETE_SUBDIR, dentry->d_name.name);
+		inotify_inode_queue_event(dentry->d_inode, IN_DELETE_SELF, NULL);
+		inotify_inode_is_dead (dentry->d_inode);
 		d_delete(dentry);
 	}
 	dput(dentry);
@@ -1780,8 +1787,11 @@
 
 	/* We don't d_delete() NFS sillyrenamed files--they still exist. */
 	if (!error && !(dentry->d_flags & DCACHE_NFSFS_RENAMED)) {
-		d_delete(dentry);
 		inode_dir_notify(dir, DN_DELETE);
+		inotify_inode_queue_event(dir, IN_DELETE_FILE, dentry->d_name.name);
+		inotify_inode_queue_event(dentry->d_inode, IN_DELETE_SELF, NULL);
+		inotify_inode_is_dead (dentry->d_inode);
+		d_delete(dentry);
 	}
 	return error;
 }
@@ -1858,6 +1868,7 @@
 	error = dir->i_op->symlink(dir, dentry, oldname);
 	if (!error) {
 		inode_dir_notify(dir, DN_CREATE);
+		inotify_inode_queue_event(dir, IN_CREATE_FILE, dentry->d_name.name);
 		security_inode_post_symlink(dir, dentry, oldname);
 	}
 	return error;
@@ -1931,6 +1942,7 @@
 	up(&old_dentry->d_inode->i_sem);
 	if (!error) {
 		inode_dir_notify(dir, DN_CREATE);
+		inotify_inode_queue_event(dir, IN_CREATE_FILE, new_dentry->d_name.name);
 		security_inode_post_link(old_dentry, dir, new_dentry);
 	}
 	return error;
@@ -2120,12 +2132,15 @@
 	else
 		error = vfs_rename_other(old_dir,old_dentry,new_dir,new_dentry);
 	if (!error) {
-		if (old_dir == new_dir)
+		if (old_dir == new_dir) {
 			inode_dir_notify(old_dir, DN_RENAME);
-		else {
+		} else {
 			inode_dir_notify(old_dir, DN_DELETE);
 			inode_dir_notify(new_dir, DN_CREATE);
 		}
+
+		inotify_inode_queue_event (old_dir, IN_MOVED_FROM, old_dentry->d_name.name);
+		inotify_inode_queue_event (new_dir, IN_MOVED_TO, new_dentry->d_name.name);
 	}
 	return error;
 }
diff -urN linux-2.6.9-rc2/fs/open.c linux/fs/open.c
--- linux-2.6.9-rc2/fs/open.c	2004-08-14 06:54:48.000000000 -0400
+++ linux/fs/open.c	2004-09-27 15:48:38.187810400 -0400
@@ -11,6 +11,7 @@
 #include <linux/smp_lock.h>
 #include <linux/quotaops.h>
 #include <linux/dnotify.h>
+#include <linux/inotify.h>
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/tty.h>
@@ -955,6 +956,8 @@
 			error = PTR_ERR(f);
 			if (IS_ERR(f))
 				goto out_error;
+			inotify_inode_queue_event (f->f_dentry->d_inode, IN_OPEN, NULL);
+			inotify_dentry_parent_queue_event (f->f_dentry, IN_OPEN, f->f_dentry->d_name.name);
 			fd_install(fd, f);
 		}
 out:
@@ -1034,6 +1037,8 @@
 	FD_CLR(fd, files->close_on_exec);
 	__put_unused_fd(files, fd);
 	spin_unlock(&files->file_lock);
+	inotify_dentry_parent_queue_event (filp->f_dentry, IN_CLOSE, filp->f_dentry->d_name.name);
+	inotify_inode_queue_event (filp->f_dentry->d_inode, IN_CLOSE, NULL);
 	return filp_close(filp, files);
 
 out_unlock:
diff -urN linux-2.6.9-rc2/fs/read_write.c linux/fs/read_write.c
--- linux-2.6.9-rc2/fs/read_write.c	2004-08-14 06:55:35.000000000 -0400
+++ linux/fs/read_write.c	2004-09-27 15:48:38.187810400 -0400
@@ -11,6 +11,7 @@
 #include <linux/uio.h>
 #include <linux/smp_lock.h>
 #include <linux/dnotify.h>
+#include <linux/inotify.h>
 #include <linux/security.h>
 #include <linux/module.h>
 
@@ -216,8 +217,11 @@
 				ret = file->f_op->read(file, buf, count, pos);
 			else
 				ret = do_sync_read(file, buf, count, pos);
-			if (ret > 0)
+			if (ret > 0) {
 				dnotify_parent(file->f_dentry, DN_ACCESS);
+				inotify_dentry_parent_queue_event(file->f_dentry, IN_ACCESS, file->f_dentry->d_name.name);
+				inotify_inode_queue_event (file->f_dentry->d_inode, IN_ACCESS, NULL);
+			}
 		}
 	}
 
@@ -260,8 +264,11 @@
 				ret = file->f_op->write(file, buf, count, pos);
 			else
 				ret = do_sync_write(file, buf, count, pos);
-			if (ret > 0)
+			if (ret > 0) {
 				dnotify_parent(file->f_dentry, DN_MODIFY);
+				inotify_dentry_parent_queue_event(file->f_dentry, IN_MODIFY, file->f_dentry->d_name.name);
+				inotify_inode_queue_event (file->f_dentry->d_inode, IN_MODIFY, NULL);
+			}
 		}
 	}
 
@@ -493,9 +500,13 @@
 out:
 	if (iov != iovstack)
 		kfree(iov);
-	if ((ret + (type == READ)) > 0)
+	if ((ret + (type == READ)) > 0) {
 		dnotify_parent(file->f_dentry,
 				(type == READ) ? DN_ACCESS : DN_MODIFY);
+		inotify_dentry_parent_queue_event(file->f_dentry, 
+				(type == READ) ? IN_ACCESS : IN_MODIFY, file->f_dentry->d_name.name);
+		inotify_inode_queue_event (file->f_dentry->d_inode, (type == READ) ? IN_ACCESS : IN_MODIFY, NULL);
+	}
 	return ret;
 }
 
diff -urN linux-2.6.9-rc2/fs/super.c linux/fs/super.c
--- linux-2.6.9-rc2/fs/super.c	2004-08-14 06:55:22.000000000 -0400
+++ linux/fs/super.c	2004-09-27 15:48:38.187810400 -0400
@@ -36,6 +36,7 @@
 #include <linux/writeback.h>		/* for the emergency remount stuff */
 #include <linux/idr.h>
 #include <asm/uaccess.h>
+#include <linux/inotify.h>
 
 
 void get_filesystem(struct file_system_type *fs);
@@ -204,6 +205,7 @@
 
 	if (root) {
 		sb->s_root = NULL;
+		inotify_super_block_umount (sb);
 		shrink_dcache_parent(root);
 		shrink_dcache_anon(&sb->s_anon);
 		dput(root);
diff -urN linux-2.6.9-rc2/include/linux/fs.h linux/include/linux/fs.h
--- linux-2.6.9-rc2/include/linux/fs.h	2004-09-20 17:04:07.000000000 -0400
+++ linux/include/linux/fs.h	2004-09-27 15:44:00.964954680 -0400
@@ -462,6 +462,12 @@
 	unsigned long		i_dnotify_mask; /* Directory notify events */
 	struct dnotify_struct	*i_dnotify; /* for directory notifications */
 
+#ifdef CONFIG_INOTIFY
+	struct list_head	watchers;
+	unsigned long		watchers_mask;
+	int			watcher_count;
+#endif
+
 	unsigned long		i_state;
 	unsigned long		dirtied_when;	/* jiffies of first dirtying */
 
diff -urN linux-2.6.9-rc2/include/linux/inotify.h linux/include/linux/inotify.h
--- linux-2.6.9-rc2/include/linux/inotify.h	1969-12-31 19:00:00.000000000 -0500
+++ linux/include/linux/inotify.h	2004-09-27 15:35:38.792296528 -0400
@@ -0,0 +1,118 @@
+/*
+ * Inode based directory notification for Linux
+ *
+ * Copyright (C) 2004 John McCutchan
+ */
+
+#ifndef _LINUX_INOTIFY_H
+#define _LINUX_INOTIFY_H
+
+#include <linux/limits.h>
+
+/* this size could limit things, since technically we could need PATH_MAX */
+#define INOTIFY_FILENAME_MAX	256
+
+/*
+ * struct inotify_event - structure read from the inotify device for each event
+ *
+ * When you are watching a directory, you will receive the filename for events
+ * such as IN_CREATE, IN_DELETE, IN_OPEN, IN_CLOSE, ...
+ *
+ * Note: When reading from the device you must provide a buffer that is a
+ * multiple of sizeof(struct inotify_event)
+ */
+struct inotify_event {
+	int wd;
+	int mask;
+	int cookie;
+	char filename[INOTIFY_FILENAME_MAX];
+};
+
+/* the following are legal, implemented events */
+#define IN_ACCESS		0x00000001	/* File was accessed */
+#define IN_MODIFY		0x00000002	/* File was modified */
+#define IN_ATTRIB		0x00000004	/* File changed attributes */
+#define IN_CLOSE		0x00000008	/* File was closed */
+#define IN_OPEN			0x00000010	/* File was opened */
+#define IN_MOVED_FROM		0x00000020	/* File was moved from X */
+#define IN_MOVED_TO		0x00000040	/* File was moved to Y */
+#define IN_DELETE_SUBDIR	0x00000080	/* Subdir was deleted */ 
+#define IN_DELETE_FILE		0x00000100	/* Subfile was deleted */
+#define IN_CREATE_SUBDIR	0x00000200	/* Subdir was created */
+#define IN_CREATE_FILE		0x00000400	/* Subfile was created */
+#define IN_DELETE_SELF		0x00000800	/* Self was deleted */
+#define IN_UNMOUNT		0x00001000	/* Backing fs was unmounted */
+#define IN_Q_OVERFLOW		0x00002000	/* Event queued overflowed */
+#define IN_IGNORED		0x00004000	/* File was ignored */
+
+/* special flags */
+#define IN_ALL_EVENTS		0xffffffff	/* All the events */
+
+/*
+ * struct inotify_watch_request - represents a watch request
+ *
+ * Pass to the inotify device via the INOTIFY_WATCH ioctl
+ */
+struct inotify_watch_request {
+	char *dirname;		/* directory name */
+	unsigned long mask;	/* event mask */
+};
+
+#define INOTIFY_IOCTL_MAGIC	'Q'
+#define INOTIFY_IOCTL_MAXNR	4
+
+#define INOTIFY_WATCH  		_IOR(INOTIFY_IOCTL_MAGIC, 1, struct inotify_watch_request)
+#define INOTIFY_IGNORE 		_IOR(INOTIFY_IOCTL_MAGIC, 2, int)
+#define INOTIFY_STATS		_IOR(INOTIFY_IOCTL_MAGIC, 3, int)
+#define INOTIFY_SETDEBUG	_IOR(INOTIFY_IOCTL_MAGIC, 4, int)
+
+#define INOTIFY_DEBUG_NONE	0x00000000
+#define INOTIFY_DEBUG_ALLOC	0x00000001
+#define INOTIFY_DEBUG_EVENTS	0x00000002
+#define INOTIFY_DEBUG_INODE	0x00000004
+#define INOTIFY_DEBUG_ERRORS	0x00000008
+#define INOTIFY_DEBUG_FILEN	0x00000010
+#define INOTIFY_DEBUG_ALL	0xffffffff
+
+#ifdef __KERNEL__
+
+#include <linux/dcache.h>
+#include <linux/fs.h>
+#include <linux/config.h>
+
+#ifdef CONFIG_INOTIFY
+
+extern void inotify_inode_queue_event(struct inode *, unsigned long,
+		const char *);
+extern void inotify_dentry_parent_queue_event(struct dentry *, unsigned long,
+		const char *);
+extern void inotify_super_block_umount(struct super_block *);
+extern void inotify_inode_is_dead(struct inode *);
+
+#else
+
+static inline void inotify_inode_queue_event(struct inode *inode,
+					     unsigned long mask,
+					     const char *filename)
+{
+}
+
+static inline void inotify_dentry_parent_queue_event(struct dentry *dentry,
+						     unsigned long mask,
+						     const char *filename)
+{
+}
+
+static inline void inotify_super_block_umount(struct super_block *sb)
+{
+}
+
+static inline void inotify_inode_is_dead(struct inode *inode)
+{
+}
+
+#endif	/* CONFIG_INOTIFY */
+
+#endif	/* __KERNEL __ */
+
+#endif	/* _LINUX_INOTIFY_H */
