source: scripts/untested/blfs-patches/inotify-0.17-rml-2.6.10-2.patch@ fcf217f

drivers/char/inotify.c

@@ +1 @@
+/*
+ * 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.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
+#include <linux/idr.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/namei.h>
+#include <linux/poll.h>
+#include <linux/device.h>
+#include <linux/miscdevice.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/writeback.h>
+#include <linux/inotify.h>
+
+#include <asm/ioctls.h>
+
+static atomic_t inotify_cookie;
+static kmem_cache_t *watch_cachep;
+static kmem_cache_t *event_cachep;
+static kmem_cache_t *inode_data_cachep;
+
+static int sysfs_attrib_max_user_devices;
+static int sysfs_attrib_max_user_watches;
+static unsigned int sysfs_attrib_max_queued_events;
+
+/*
+ * 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.
+ *
+ * This structure is protected by 'lock'.  Lock ordering:
+ *
+ * dev->lock (protects dev)
+ *      inode_lock (used to safely walk inode_in_use list)
+ *              inode->i_lock (only needed for getting ref on inode_data)
+ */
+struct inotify_device {
+        wait_queue_head_t       wait;
+        struct idr              idr;
+        struct list_head        events;
+        struct list_head        watches;
+        spinlock_t              lock;
+        unsigned int            event_count;
+        unsigned int            max_events;
+        struct user_struct      *user;
+};
+
+struct inotify_watch {
+        s32                     wd;     /* watch descriptor */
+        u32                     mask;
+        struct inode            *inode;
+        struct inotify_device   *dev;
+        struct list_head        d_list; /* device list */
+        struct list_head        i_list; /* inode list */
+};
+
+static ssize_t show_max_queued_events(struct class_device *class, char *buf)
+{
+        return sprintf(buf, "%d\n", sysfs_attrib_max_queued_events);
+}
+
+static ssize_t store_max_queued_events(struct class_device *class,
+                                       const char *buf, size_t count)
+{
+        unsigned int max;
+
+        if (sscanf(buf, "%u", &max) > 0 && max > 0) {
+                sysfs_attrib_max_queued_events = max;
+                return strlen(buf);
+        }
+        return -EINVAL;
+}
+
+static ssize_t show_max_user_devices(struct class_device *class, char *buf)
+{
+        return sprintf(buf, "%d\n", sysfs_attrib_max_user_devices);
+}
+
+static ssize_t store_max_user_devices(struct class_device *class,
+                                      const char *buf, size_t count)
+{
+        int max;
+
+        if (sscanf(buf, "%d", &max) > 0 && max > 0) {
+                sysfs_attrib_max_user_devices = max;
+                return strlen(buf);
+        }
+        return -EINVAL;
+}
+
+static ssize_t show_max_user_watches(struct class_device *class, char *buf)
+{
+        return sprintf(buf, "%d\n", sysfs_attrib_max_user_watches);
+}
+
+static ssize_t store_max_user_watches(struct class_device *class,
+                                      const char *buf, size_t count)
+{
+        int max;
+
+        if (sscanf(buf, "%d", &max) > 0 && max > 0) {
+                sysfs_attrib_max_user_watches = max;
+                return strlen(buf);
+        }
+        return -EINVAL;
+}
+
+static CLASS_DEVICE_ATTR(max_queued_events, S_IRUGO | S_IWUSR,
+        show_max_queued_events, store_max_queued_events);
+static CLASS_DEVICE_ATTR(max_user_devices, S_IRUGO | S_IWUSR,
+        show_max_user_devices, store_max_user_devices);
+static CLASS_DEVICE_ATTR(max_user_watches, S_IRUGO | S_IWUSR,
+        show_max_user_watches, store_max_user_watches);
+
+/*
+ * 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;
+};
+
+static inline void __get_inode_data(struct inotify_inode_data *data)
+{
+        atomic_inc(&data->count);
+}
+
+/*
+ * get_inode_data - pin an inotify_inode_data structure.  Returns the structure
+ * if successful and NULL on failure, which can only occur if inotify_data is
+ * not yet allocated.  The inode must be pinned prior to invocation.
+ */
+static inline struct inotify_inode_data * get_inode_data(struct inode *inode)
+{
+        struct inotify_inode_data *data;
+
+        spin_lock(&inode->i_lock);
+        data = inode->inotify_data;
+        if (data)
+                __get_inode_data(data);
+        spin_unlock(&inode->i_lock);
+
+        return data;
+}
+
+/*
+ * put_inode_data - drop our reference on an inotify_inode_data and the
+ * inode structure in which it lives.  If the reference count on inotify_data
+ * reaches zero, free it.
+ */
+static inline void put_inode_data(struct inode *inode)
+{
+        //spin_lock(&inode->i_lock);
+        if (atomic_dec_and_test(&inode->inotify_data->count)) {
+                kmem_cache_free(inode_data_cachep, inode->inotify_data);
+                inode->inotify_data = NULL;
+        }
+        //spin_unlock(&inode->i_lock);
+}
+
+/*
+ * 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)
+                return ERR_PTR(error);
+
+        inode = nd.dentry->d_inode;
+
+        /* you can only watch an inode if you have read permissions on it */
+        error = permission(inode, MAY_READ, NULL);
+        if (error) {
+                inode = ERR_PTR(error);
+                goto release_and_out;
+        }
+
+        spin_lock(&inode_lock);
+        __iget(inode);
+        spin_unlock(&inode_lock);
+release_and_out:
+        path_release(&nd);
+        return inode;
+}
+
+struct inotify_kernel_event * kernel_event(s32 wd, u32 mask, u32 cookie,
+                                           const char *filename)
+{
+        struct inotify_kernel_event *kevent;
+
+        kevent = kmem_cache_alloc(event_cachep, GFP_ATOMIC);
+        if (!kevent)
+                return NULL;
+
+        /* we hand this out to user-space, so zero it out just in case */
+        memset(kevent, 0, sizeof(struct inotify_kernel_event));
+
+        kevent->event.wd = wd;
+        kevent->event.mask = mask;
+        kevent->event.cookie = cookie;
+        INIT_LIST_HEAD(&kevent->list);
+
+        if (filename) {
+                strncpy(kevent->event.filename, filename, INOTIFY_FILENAME_MAX);
+                kevent->event.filename[INOTIFY_FILENAME_MAX-1] = '\0';
+        } else
+                kevent->event.filename[0] = '\0';
+
+        return kevent;
+}
+
+void delete_kernel_event(struct inotify_kernel_event *kevent)
+{
+        if (!kevent)
+                return;
+        kmem_cache_free(event_cachep, kevent);
+}
+
+#define list_to_inotify_kernel_event(pos)       \
+                list_entry((pos), struct inotify_kernel_event, list)
+
+#define inotify_dev_get_event(dev)              \
+                (list_to_inotify_kernel_event(dev->events.next))
+
+/* Does this events mask get sent to the watch ? */
+#define event_and(event_mask,watches_mask)      ((event_mask == IN_UNMOUNT) || \
+                                                (event_mask == IN_IGNORED) || \
+                                                (event_mask & watches_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_watch *watch, u32 mask,
+                                    u32 cookie, const char *filename)
+{
+        struct inotify_kernel_event *kevent, *last;
+
+        /* Check if the new event is a duplicate of the last event queued. */
+        last = inotify_dev_get_event(dev);
+        if (dev->event_count && last->event.mask == mask &&
+                        last->event.wd == watch->wd) {
+                /* Check if the filenames match */
+                if (!filename && last->event.filename[0] == '\0')
+                        return;
+                if (filename && !strcmp(last->event.filename, filename))
+                        return;
+        }
+
+        /*
+         * the queue has already overflowed and we have already sent the
+         * Q_OVERFLOW event
+         */
+        if (dev->event_count > dev->max_events)
+                return;
+
+        /* the queue has just overflowed and we need to notify user space */
+        if (dev->event_count == dev->max_events) {
+                kevent = kernel_event(-1, IN_Q_OVERFLOW, cookie, NULL);
+                goto add_event_to_queue;
+        }
+
+        if (!event_and(mask, watch->inode->inotify_data->watch_mask) ||
+                        !event_and(mask, watch->mask))
+                return;
+
+        kevent = kernel_event(watch->wd, mask, cookie, filename);
+
+add_event_to_queue:
+        if (!kevent)
+                return;
+
+        /* queue the event and wake up anyone waiting */
+        dev->event_count++;     
+        list_add_tail(&kevent->list, &dev->events);
+        wake_up_interruptible(&dev->wait);
+}
+
+static inline int inotify_dev_has_events(struct inotify_device *dev)
+{
+        return !list_empty(&dev->events);
+}
+
+/*
+ * 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_init(&kevent->list);
+        dev->event_count--;
+        delete_kernel_event(kevent);
+}
+
+/*
+ * inotify_dev_get_wd - returns the next WD for use by the given dev
+ *
+ * This function can sleep.
+ */
+static int inotify_dev_get_wd(struct inotify_device *dev,
+                             struct inotify_watch *watch)
+{
+        int ret;
+
+        if (atomic_read(&dev->user->inotify_watches) >=
+                        sysfs_attrib_max_user_watches)
+                return -ENOSPC;
+
+repeat:
+        if (!idr_pre_get(&dev->idr, GFP_KERNEL))
+                return -ENOSPC;
+        spin_lock(&dev->lock);
+        ret = idr_get_new(&dev->idr, watch, &watch->wd);
+        spin_unlock(&dev->lock);
+        if (ret == -EAGAIN) /* more memory is required, try again */
+                goto repeat;
+        else if (ret)       /* the idr is full! */
+                return -ENOSPC;
+
+        atomic_inc(&dev->user->inotify_watches);
+
+        return 0;
+}
+
+/*
+ * 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, s32 wd)
+{
+        if (!dev || wd < 0)
+                return -1;
+
+        atomic_dec(&dev->user->inotify_watches);
+        idr_remove(&dev->idr, wd);
+
+        return 0;
+}
+
+/*
+ * create_watch - creates a watch on the given device.
+ *
+ * Grabs dev->lock, so the caller must not hold it.
+ */
+static struct inotify_watch *create_watch(struct inotify_device *dev,
+                                          u32 mask, struct inode *inode)
+{
+        struct inotify_watch *watch;
+
+        watch = kmem_cache_alloc(watch_cachep, GFP_KERNEL);
+        if (!watch)
+                return NULL;
+
+        watch->mask = mask;
+        watch->inode = inode;
+        watch->dev = dev;
+        INIT_LIST_HEAD(&watch->d_list);
+        INIT_LIST_HEAD(&watch->i_list);
+
+        if (inotify_dev_get_wd(dev, watch)) {
+                kmem_cache_free(watch_cachep, watch);
+                return NULL;
+        }
+
+        return watch;
+}
+
+/*
+ * delete_watch - removes the given 'watch' from the given 'dev'
+ *
+ * Caller must hold dev->lock.
+ */
+static void delete_watch(struct inotify_device *dev,
+                         struct inotify_watch *watch)
+{
+        inotify_dev_put_wd(dev, watch->wd);
+        kmem_cache_free(watch_cachep, watch);
+}
+
+/*
+ * inotify_find_dev - find the watch associated with the given inode and dev
+ *
+ * Caller must hold dev->lock.
+ * FIXME: Needs inotify_data->lock too.  Don't need dev->lock, just pin it.
+ */
+static struct inotify_watch *inode_find_dev(struct inode *inode,
+                                            struct inotify_device *dev)
+{
+        struct inotify_watch *watch;
+
+        if (!inode->inotify_data)
+                return NULL;
+
+        list_for_each_entry(watch, &inode->inotify_data->watches, i_list) {
+                if (watch->dev == dev)
+                        return watch;
+        }
+
+        return NULL;
+}
+
+/*
+ * dev_find_wd - given a (dev,wd) pair, returns the matching inotify_watcher
+ *
+ * Returns the results of looking up (dev,wd) in the idr layer.  NULL is
+ * returned on error.
+ *
+ * The caller must hold dev->lock.
+ */
+static inline struct inotify_watch *dev_find_wd(struct inotify_device *dev,
+                                                u32 wd)
+{
+        return idr_find(&dev->idr, wd);
+}
+
+static int inotify_dev_is_watching_inode(struct inotify_device *dev,
+                                         struct inode *inode)
+{
+        struct inotify_watch *watch;
+
+        list_for_each_entry(watch, &dev->watches, d_list) {
+                if (watch->inode == inode)
+                        return 1;
+        }
+
+        return 0;
+}
+
+/*
+ * inotify_dev_add_watcher - add the given watcher to the given device instance
+ *
+ * Caller must hold dev->lock.
+ */
+static int inotify_dev_add_watch(struct inotify_device *dev,
+                                 struct inotify_watch *watch)
+{
+        if (!dev || !watch)
+                return -EINVAL;
+
+        list_add(&watch->d_list, &dev->watches);
+        return 0;
+}
+
+/*
+ * inotify_dev_rm_watch - 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_watch(struct inotify_device *dev,
+                                struct inotify_watch *watch)
+{
+        if (!watch)
+                return -EINVAL;
+
+        inotify_dev_queue_event(dev, watch, IN_IGNORED, 0, NULL);
+        list_del_init(&watch->d_list);
+
+        return 0;
+}
+
+/*
+ * inode_update_watch_mask - update inode->inotify_data->watch_mask
+ *
+ * Grabs inode->inotify_data->lock.
+ */
+static void inode_update_watch_mask(struct inode *inode)
+{
+        struct inotify_inode_data *data;
+        struct inotify_watch *watch;
+        u32 new_mask;
+
+        data = get_inode_data(inode);
+        if (!data)      /* FIXME: this should never happen */
+                return;
+        spin_lock(&data->lock);
+
+        new_mask = 0;
+        list_for_each_entry(watch, &data->watches, i_list)
+                new_mask |= watch->mask;
+
+        data->watch_mask = new_mask;
+
+        spin_unlock(&data->lock);
+        put_inode_data(inode);
+}
+
+/*
+ * inode_add_watch - add a watch to the given inode
+ *
+ * Callers must hold dev->lock, because we call inode_find_dev().
+ */
+static int inode_add_watch(struct inode *inode, struct inotify_watch *watch)
+{
+        int ret;
+
+        if (!inode || !watch)
+                return -EINVAL;
+
+        spin_lock(&inode->i_lock);
+        if (!inode->inotify_data) {
+                /* inotify_data is not attached to the inode, so add it */
+                inode->inotify_data = kmem_cache_alloc(inode_data_cachep,
+                                                       GFP_ATOMIC);
+                if (!inode->inotify_data) {
+                        ret = -ENOMEM;
+                        goto out_lock;
+                }
+
+                atomic_set(&inode->inotify_data->count, 0);
+                INIT_LIST_HEAD(&inode->inotify_data->watches);
+                inode->inotify_data->watch_mask = 0;
+                spin_lock_init(&inode->inotify_data->lock);
+        } else if (inode_find_dev(inode, watch->dev)) {
+                /* a watch is already associated with this (inode,dev) pair */
+                ret = -EINVAL;
+                goto out_lock;
+        }
+        __get_inode_data(inode->inotify_data);
+        spin_unlock(&inode->i_lock);
+
+        list_add(&watch->i_list, &inode->inotify_data->watches);
+        inode_update_watch_mask(inode);
+
+        return 0;
+out_lock:
+        spin_unlock(&inode->i_lock);
+        return ret;
+}
+
+static int inode_rm_watch(struct inode *inode,
+                          struct inotify_watch *watch)
+{
+        if (!inode || !watch || !inode->inotify_data)
+                return -EINVAL;
+
+        list_del_init(&watch->i_list);
+        inode_update_watch_mask(inode);
+
+        /* clean up inode->inotify_data */
+        put_inode_data(inode);  
+
+        return 0;
+}
+
+/* Kernel API */
+
+/*
+ * inotify_inode_queue_event - queue an event with the given mask, cookie, and
+ * filename to any watches associated with the given inode.
+ *
+ * inode must be pinned prior to calling.
+ */
+void inotify_inode_queue_event(struct inode *inode, u32 mask, u32 cookie,
+                               const char *filename)
+{
+        struct inotify_watch *watch;
+
+        if (!inode->inotify_data)
+                return;
+
+        list_for_each_entry(watch, &inode->inotify_data->watches, i_list) {
+                spin_lock(&watch->dev->lock);
+                inotify_dev_queue_event(watch->dev, watch, mask, cookie,
+                                        filename);
+                spin_unlock(&watch->dev->lock);
+        }
+}
+EXPORT_SYMBOL_GPL(inotify_inode_queue_event);
+
+void inotify_dentry_parent_queue_event(struct dentry *dentry, u32 mask,
+                                       u32 cookie, const char *filename)
+{
+        struct dentry *parent;
+
+        parent = dget_parent(dentry);
+        inotify_inode_queue_event(parent->d_inode, mask, cookie, filename);
+        dput(parent);
+}
+EXPORT_SYMBOL_GPL(inotify_dentry_parent_queue_event);
+
+u32 inotify_get_cookie(void)
+{
+        atomic_inc(&inotify_cookie);
+        return atomic_read(&inotify_cookie);
+}
+EXPORT_SYMBOL_GPL(inotify_get_cookie);
+
+/*
+ * watch->inode must be pinned.  We drop a reference before returning.
+ */
+static void ignore_helper(struct inotify_watch *watch, int event)
+{
+        struct inotify_device *dev;
+        struct inode *inode;
+
+        inode = watch->inode;
+        dev = watch->dev;
+
+        spin_lock(&dev->lock);
+
+        if (event)
+                inotify_dev_queue_event(dev, watch, event, 0, NULL);
+
+        inode_rm_watch(inode, watch);
+        inotify_dev_rm_watch(watch->dev, watch);
+
+        delete_watch(dev, watch);
+        spin_unlock(&dev->lock);
+
+        iput(inode);
+}
+
+void inotify_super_block_umount(struct super_block *sb)
+{
+        struct inode *inode;
+
+        spin_lock(&inode_lock);
+
+        /*
+         * We hold the inode_lock, so the inodes are not going anywhere, and
+         * we grab a reference on inotify_data before walking its list of
+         * watches.
+         */
+        list_for_each_entry(inode, &inode_in_use, i_list) {
+                struct inotify_inode_data *inode_data;
+                struct inotify_watch *watch;
+
+                if (inode->i_sb != sb)
+                        continue;
+
+                inode_data = get_inode_data(inode);
+                if (!inode_data)
+                        continue;
+
+                list_for_each_entry(watch, &inode_data->watches, i_list)
+                        ignore_helper(watch, IN_UNMOUNT);
+                put_inode_data(inode);
+        }
+
+        spin_unlock(&inode_lock);
+}
+EXPORT_SYMBOL_GPL(inotify_super_block_umount);
+
+/*
+ * inotify_inode_is_dead - an inode has been deleted, cleanup any watches
+ */
+void inotify_inode_is_dead(struct inode *inode)
+{
+        struct inotify_watch *watch, *next;
+        struct inotify_inode_data *data;
+
+        data = get_inode_data(inode);
+        if (!data)
+                return;
+        list_for_each_entry_safe(watch, next, &data->watches, i_list)
+                ignore_helper(watch, 0);
+        put_inode_data(inode);
+}
+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;
+}
+
+static ssize_t inotify_read(struct file *file, char __user *buf,
+                            size_t count, loff_t *pos)
+{
+        size_t event_size;
+        struct inotify_device *dev;
+        char __user *start;
+        DECLARE_WAITQUEUE(wait, current);
+
+        start = buf;
+        dev = file->private_data;
+
+        /* We only hand out full inotify events */
+        event_size = sizeof(struct inotify_event);
+        if (count < event_size)
+                return -EINVAL;
+
+        while (1) {
+                int has_events;
+
+                spin_lock(&dev->lock);
+                has_events = inotify_dev_has_events(dev);
+                spin_unlock(&dev->lock);
+                if (has_events)
+                        break;
+
+                if (file->f_flags & O_NONBLOCK)
+                        return -EAGAIN;
+
+                if (signal_pending(current))
+                        return -ERESTARTSYS;
+
+                add_wait_queue(&dev->wait, &wait);
+                set_current_state(TASK_INTERRUPTIBLE);
+
+                schedule();
+
+                set_current_state(TASK_RUNNING);                
+                remove_wait_queue(&dev->wait, &wait);
+        }
+
+        while (count >= event_size) {
+                struct inotify_kernel_event *kevent;
+
+                spin_lock(&dev->lock);
+                if (!inotify_dev_has_events(dev)) {
+                        spin_unlock(&dev->lock);
+                        break;
+                }
+                kevent = inotify_dev_get_event(dev);
+                spin_unlock(&dev->lock);
+                if (copy_to_user(buf, &kevent->event, event_size))
+                        return -EFAULT;
+
+                spin_lock(&dev->lock);
+                inotify_dev_event_dequeue(dev);
+                spin_unlock(&dev->lock);
+                count -= event_size;
+                buf += event_size;
+        }
+
+        return buf - start;
+}
+
+static int inotify_open(struct inode *inode, struct file *file)
+{
+        struct inotify_device *dev;
+        struct user_struct *user;
+        int ret;
+
+        user = get_uid(current->user);
+
+        if (atomic_read(&user->inotify_devs) >= sysfs_attrib_max_user_devices) {
+                ret = -ENOSPC;
+                goto out_err;
+        }
+
+        atomic_inc(&current->user->inotify_devs);
+
+        dev = kmalloc(sizeof(struct inotify_device), GFP_KERNEL);
+        if (!dev) {
+                ret = -ENOMEM;
+                goto out_err;
+        }
+
+        idr_init(&dev->idr);
+
+        INIT_LIST_HEAD(&dev->events);
+        INIT_LIST_HEAD(&dev->watches);
+        init_waitqueue_head(&dev->wait);
+
+        dev->event_count = 0;
+        dev->max_events = sysfs_attrib_max_queued_events;
+        dev->user = user;
+        spin_lock_init(&dev->lock);
+
+        file->private_data = dev;
+
+        return 0;
+out_err:
+        free_uid(current->user);
+        return ret;
+}
+
+/*
+ * inotify_release_all_watches - destroy all watches on a given device
+ *
+ * FIXME: Do we want a lock here?
+ */
+static void inotify_release_all_watches(struct inotify_device *dev)
+{
+        struct inotify_watch *watch, *next;
+
+        list_for_each_entry_safe(watch, next, &dev->watches, d_list)
+                ignore_helper(watch, 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;
+
+        inotify_release_all_watches(dev);
+        inotify_release_all_events(dev);
+
+        atomic_dec(&dev->user->inotify_devs);
+        free_uid(dev->user);
+
+        kfree(dev);
+
+        return 0;
+}
+
+static int inotify_add_watch(struct inotify_device *dev,
+                             struct inotify_watch_request *request)
+{
+        struct inode *inode;
+        struct inotify_watch *watch;
+        int ret;
+
+        inode = find_inode((const char __user*) request->dirname);
+        if (IS_ERR(inode))
+                return PTR_ERR(inode);
+
+        spin_lock(&dev->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_watch *owatch;   /* the old watch */
+
+                owatch = inode_find_dev(inode, dev);
+                owatch->mask = request->mask;
+                inode_update_watch_mask(inode);
+                spin_unlock(&dev->lock);
+                iput(inode);
+
+                return owatch->wd;
+        }
+
+        spin_unlock(&dev->lock);
+
+        watch = create_watch(dev, request->mask, inode);
+        if (!watch) {
+                iput(inode);
+                return -ENOSPC;
+        }
+
+        spin_lock(&dev->lock);
+
+        /* We can't add anymore watches to this device */
+        if (inotify_dev_add_watch(dev, watch)) {
+                delete_watch(dev, watch);
+                spin_unlock(&dev->lock);
+                iput(inode);
+                return -EINVAL;
+        }
+
+        ret = inode_add_watch(inode, watch);
+        if (ret < 0) {
+                list_del_init(&watch->d_list);
+                delete_watch(dev, watch);
+                spin_unlock(&dev->lock);
+                iput(inode);
+                return ret;
+        }
+
+        spin_unlock(&dev->lock);
+
+        return watch->wd;
+}
+
+static int inotify_ignore(struct inotify_device *dev, s32 wd)
+{
+        struct inotify_watch *watch;
+
+        /*
+         * FIXME: Silly to grab dev->lock here and then drop it, when
+         * ignore_helper() grabs it anyway a few lines down.
+         */
+        spin_lock(&dev->lock);
+        watch = dev_find_wd(dev, wd);
+        spin_unlock(&dev->lock);
+        if (!watch)
+                return -EINVAL;
+        ignore_helper(watch, 0);
+
+        return 0;
+}
+
+/*
+ * inotify_ioctl() - our device file's ioctl method
+ *
+ * The VFS serializes all of our calls via the BKL and we rely on that.  We
+ * could, alternatively, grab dev->lock.  Right now lower levels grab that
+ * where needed.
+ */
+static int inotify_ioctl(struct inode *ip, struct file *fp,
+                         unsigned int cmd, unsigned long arg)
+{
+        struct inotify_device *dev;
+        struct inotify_watch_request request;
+        void __user *p;
+        int bytes;
+        s32 wd;
+
+        dev = fp->private_data;
+        p = (void __user *) arg;
+
+        switch (cmd) {
+        case INOTIFY_WATCH:
+                if (copy_from_user(&request, p, sizeof (request)))
+                        return -EFAULT;
+                return inotify_add_watch(dev, &request);
+        case INOTIFY_IGNORE:
+                if (copy_from_user(&wd, p, sizeof (wd)))
+                        return -EFAULT;
+                return inotify_ignore(dev, wd);
+        case FIONREAD:
+                bytes = dev->event_count * sizeof(struct inotify_event);
+                return put_user(bytes, (int __user *) p);
+        default:
+                return -ENOTTY;
+        }
+}
+
+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)
+{
+        struct class_device *class;
+        int ret;
+
+        ret = misc_register(&inotify_device);
+        if (ret)
+                return ret;
+
+        sysfs_attrib_max_queued_events = 512;
+        sysfs_attrib_max_user_devices = 64;
+        sysfs_attrib_max_user_watches = 16384;
+
+        class = inotify_device.class;
+        class_device_create_file(class, &class_device_attr_max_queued_events);
+        class_device_create_file(class, &class_device_attr_max_user_devices);
+        class_device_create_file(class, &class_device_attr_max_user_watches);
+
+        atomic_set(&inotify_cookie, 0);
+
+        watch_cachep = kmem_cache_create("inotify_watch_cache",
+                        sizeof(struct inotify_watch), 0, SLAB_PANIC,
+                        NULL, NULL);
+
+        event_cachep = kmem_cache_create("inotify_event_cache",
+                        sizeof(struct inotify_kernel_event), 0,
+                        SLAB_PANIC, NULL, NULL);
+
+        inode_data_cachep = kmem_cache_create("inotify_inode_data_cache",
+                        sizeof(struct inotify_inode_data), 0, SLAB_PANIC,
+                        NULL, NULL);
+
+        printk(KERN_INFO "inotify device minor=%d\n", inotify_device.minor);
+
+        return 0;
+}
+
+module_init(inotify_init);

drivers/char/Kconfig

@@ -62 +62 @@
         depends on VT && !S390 && !USERMODE
         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---

drivers/char/Makefile

@@ -9 +9 @@
 
 obj-y    += mem.o random.o tty_io.o n_tty.o tty_ioctl.o
 
+
+obj-$(CONFIG_INOTIFY)           += inotify.o
 obj-$(CONFIG_LEGACY_PTYS)       += pty.o
 obj-$(CONFIG_UNIX98_PTYS)       += pty.o
 obj-y                           += misc.o

drivers/char/misc.c

@@ -207 +207 @@
 int misc_register(struct miscdevice * misc)
 {
         struct miscdevice *c;
-        struct class_device *class;
         dev_t dev;
         int err;
-        
+
         down(&misc_sem);
         list_for_each_entry(c, &misc_list, list) {
                 if (c->minor == misc->minor) {
@@ -224 +223 @@
                 while (--i >= 0)
                         if ( (misc_minors[i>>3] & (1 << (i&7))) == 0)
                                 break;
-                if (i<0)
-                {
+                if (i<0) {
                         up(&misc_sem);
                         return -EBUSY;
                 }
@@ -240 +238 @@
         }
         dev = MKDEV(MISC_MAJOR, misc->minor);
 
-        class = class_simple_device_add(misc_class, dev,
-                                        misc->dev, misc->name);
-        if (IS_ERR(class)) {
-                err = PTR_ERR(class);
+        misc->class = class_simple_device_add(misc_class, dev,
+                                              misc->dev, misc->name);
+        if (IS_ERR(misc->class)) {
+                err = PTR_ERR(misc->class);
                 goto out;
         }
 

fs/attr.c

@@ -11 +11 @@
 #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>
@@ -103 +104 @@
 out:
         return error;
 }
-
 EXPORT_SYMBOL(inode_setattr);
 
-int setattr_mask(unsigned int ia_valid)
+void setattr_mask (unsigned int ia_valid, int *dn_mask, u32 *in_mask)
 {
-        unsigned long dn_mask = 0;
+        int dnmask;
+        u32 inmask;
 
-        if (ia_valid & ATTR_UID)
-                dn_mask |= DN_ATTRIB;
-        if (ia_valid & ATTR_GID)
-                dn_mask |= DN_ATTRIB;
-        if (ia_valid & ATTR_SIZE)
-                dn_mask |= DN_MODIFY;
-        /* both times implies a utime(s) call */
-        if ((ia_valid & (ATTR_ATIME|ATTR_MTIME)) == (ATTR_ATIME|ATTR_MTIME))
-                dn_mask |= DN_ATTRIB;
-        else if (ia_valid & ATTR_ATIME)
-                dn_mask |= DN_ACCESS;
-        else if (ia_valid & ATTR_MTIME)
-                dn_mask |= DN_MODIFY;
-        if (ia_valid & ATTR_MODE)
-                dn_mask |= DN_ATTRIB;
-        return dn_mask;
+        inmask = 0;
+        dnmask = 0;
+
+        if (!dn_mask || !in_mask) {
+                return;
+        }
+        if (ia_valid & ATTR_UID) {
+                inmask |= IN_ATTRIB;
+                dnmask |= DN_ATTRIB;
+        }
+        if (ia_valid & ATTR_GID) {
+                inmask |= IN_ATTRIB;
+                dnmask |= DN_ATTRIB;
+        }
+        if (ia_valid & ATTR_SIZE) {
+                inmask |= IN_MODIFY;
+                dnmask |= DN_MODIFY;
+        }
+        /* both times implies a utime(s) call */
+        if ((ia_valid & (ATTR_ATIME|ATTR_MTIME)) == (ATTR_ATIME|ATTR_MTIME)) {
+                inmask |= IN_ATTRIB;
+                dnmask |= DN_ATTRIB;
+        }
+        else if (ia_valid & ATTR_ATIME) {
+                inmask |= IN_ACCESS;
+                dnmask |= DN_ACCESS;
+        }
+        else if (ia_valid & ATTR_MTIME) {
+                inmask |= IN_MODIFY;
+                dnmask |= DN_MODIFY;
+        }
+        if (ia_valid & ATTR_MODE) {
+                inmask |= IN_ATTRIB;
+                dnmask |= DN_ATTRIB;
+        }
+
+        *in_mask = inmask;
+        *dn_mask = dnmask;
 }
 
 int notify_change(struct dentry * dentry, struct iattr * attr)
@@ -184 +207 @@
                 }
         }
         if (!error) {
-                unsigned long dn_mask = setattr_mask(ia_valid);
+                int dn_mask;
+                u32 in_mask;
+
+                setattr_mask (ia_valid, &dn_mask, &in_mask);
+
                 if (dn_mask)
                         dnotify_parent(dentry, dn_mask);
+                if (in_mask) {
+                        inotify_inode_queue_event(dentry->d_inode, in_mask, 0,
+                                                  NULL);
+                        inotify_dentry_parent_queue_event(dentry, in_mask, 0,
+                                                          dentry->d_name.name);
+                }
         }
         return error;
 }

fs/file_table.c

@@ -16 +16 @@
 #include <linux/eventpoll.h>
 #include <linux/mount.h>
 #include <linux/cdev.h>
+#include <linux/inotify.h>
 
 /* sysctl tunables... */
 struct files_stat_struct files_stat = {
@@ -120 +121 @@
         struct dentry *dentry = file->f_dentry;
         struct vfsmount *mnt = file->f_vfsmnt;
         struct inode *inode = dentry->d_inode;
+        u32 mask;
+
+
+        mask = (file->f_mode & FMODE_WRITE) ? IN_CLOSE_WRITE : IN_CLOSE_NOWRITE;
+        inotify_dentry_parent_queue_event(dentry, mask, 0, dentry->d_name.name);
+        inotify_inode_queue_event(inode, mask, 0, NULL);
 
         might_sleep();
         /*

fs/inode.c

@@ -130 +130 @@
 #ifdef CONFIG_QUOTA
                 memset(&inode->i_dquot, 0, sizeof(inode->i_dquot));
 #endif
+#ifdef CONFIG_INOTIFY
+                inode->inotify_data = NULL;
+#endif
                 inode->i_pipe = NULL;
                 inode->i_bdev = NULL;
                 inode->i_cdev = NULL;

fs/namei.c

@@ -22 +22 @@
 #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>
@@ -1242 +1243 @@
         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,
+                                0, dentry->d_name.name);
                 security_inode_post_create(dir, dentry, mode);
         }
         return error;
@@ -1556 +1559 @@
         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, 0,
+                                dentry->d_name.name);
                 security_inode_post_mknod(dir, dentry, mode, dev);
         }
         return error;
@@ -1629 +1634 @@
         error = dir->i_op->mkdir(dir, dentry, mode);
         if (!error) {
                 inode_dir_notify(dir, DN_CREATE);
+                inotify_inode_queue_event(dir, IN_CREATE_SUBDIR, 0,
+                                dentry->d_name.name);
                 security_inode_post_mkdir(dir,dentry, mode);
         }
         return error;
@@ -1724 +1731 @@
         up(&dentry->d_inode->i_sem);
         if (!error) {
                 inode_dir_notify(dir, DN_DELETE);
+                inotify_inode_queue_event(dir, IN_DELETE_SUBDIR, 0,
+                                dentry->d_name.name);
+                inotify_inode_queue_event(dentry->d_inode, IN_DELETE_SELF, 0,
+                                NULL);
+                inotify_inode_is_dead (dentry->d_inode);
                 d_delete(dentry);
         }
         dput(dentry);
@@ -1796 +1808 @@
 
         /* 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, 0,
+                                dentry->d_name.name);
+                inotify_inode_queue_event(dentry->d_inode, IN_DELETE_SELF, 0,
+                                NULL);
+                inotify_inode_is_dead (dentry->d_inode);
+                d_delete(dentry);
         }
         return error;
 }
@@ -1873 +1890 @@
         error = dir->i_op->symlink(dir, dentry, oldname);
         if (!error) {
                 inode_dir_notify(dir, DN_CREATE);
+                inotify_inode_queue_event(dir, IN_CREATE_FILE, 0,
+                                dentry->d_name.name);
                 security_inode_post_symlink(dir, dentry, oldname);
         }
         return error;
@@ -1946 +1965 @@
         up(&old_dentry->d_inode->i_sem);
         if (!error) {
                 inode_dir_notify(dir, DN_CREATE);
+                inotify_inode_queue_event(dir, IN_CREATE_FILE, 0, 
+                                        new_dentry->d_name.name);
                 security_inode_post_link(old_dentry, dir, new_dentry);
         }
         return error;
@@ -2109 +2130 @@
 {
         int error;
         int is_dir = S_ISDIR(old_dentry->d_inode->i_mode);
+        char *old_name;
+        u32 cookie;
 
         if (old_dentry->d_inode == new_dentry->d_inode)
                 return 0;
@@ -2130 +2153 @@
         DQUOT_INIT(old_dir);
         DQUOT_INIT(new_dir);
 
+        old_name = inotify_oldname_init(old_dentry);
+
         if (is_dir)
                 error = vfs_rename_dir(old_dir,old_dentry,new_dir,new_dentry);
         else
@@ -2141 +2166 @@
                         inode_dir_notify(old_dir, DN_DELETE);
                         inode_dir_notify(new_dir, DN_CREATE);
                 }
+
+                cookie = inotify_get_cookie();
+
+                inotify_inode_queue_event(old_dir, IN_MOVED_FROM, cookie,
+                                          old_name);
+                inotify_inode_queue_event(new_dir, IN_MOVED_TO, cookie,
+                                          old_dentry->d_name.name);
         }
+        inotify_oldname_free(old_name);
+
         return error;
 }
 

fs/open.c

@@ -11 +11 @@
 #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>
@@ -956 +957 @@
                         error = PTR_ERR(f);
                         if (IS_ERR(f))
                                 goto out_error;
+                        inotify_inode_queue_event(f->f_dentry->d_inode,
+                                        IN_OPEN, 0, NULL);
+                        inotify_dentry_parent_queue_event(f->f_dentry, IN_OPEN,
+                                        0, f->f_dentry->d_name.name);
                         fd_install(fd, f);
                 }
 out:

fs/read_write.c

@@ -11 +11 @@
 #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>
 #include <linux/syscalls.h>
@@ -216 +217 @@
                                 ret = file->f_op->read(file, buf, count, pos);
                         else
                                 ret = do_sync_read(file, buf, count, pos);
-                        if (ret > 0)
-                                dnotify_parent(file->f_dentry, DN_ACCESS);
+                        if (ret > 0) {
+                                struct dentry *dentry = file->f_dentry;
+                                dnotify_parent(dentry, DN_ACCESS);
+                                inotify_dentry_parent_queue_event(dentry,
+                                                IN_ACCESS, 0, dentry->d_name.name);
+                                inotify_inode_queue_event(inode, IN_ACCESS, 0,
+                                                NULL);
+                        }
                 }
         }
 
@@ -260 +267 @@
                                 ret = file->f_op->write(file, buf, count, pos);
                         else
                                 ret = do_sync_write(file, buf, count, pos);
-                        if (ret > 0)
-                                dnotify_parent(file->f_dentry, DN_MODIFY);
+                        if (ret > 0) {
+                                struct dentry *dentry = file->f_dentry;
+                                dnotify_parent(dentry, DN_MODIFY);
+                                inotify_dentry_parent_queue_event(dentry,
+                                                IN_MODIFY, 0, dentry->d_name.name);
+                                inotify_inode_queue_event(inode, IN_MODIFY, 0,
+                                                NULL);
+                        }
                 }
         }
 
@@ -493 +506 @@
 out:
         if (iov != iovstack)
                 kfree(iov);
-        if ((ret + (type == READ)) > 0)
-                dnotify_parent(file->f_dentry,
-                                (type == READ) ? DN_ACCESS : DN_MODIFY);
+        if ((ret + (type == READ)) > 0) {
+                struct dentry *dentry = file->f_dentry;
+                dnotify_parent(dentry, (type == READ) ? DN_ACCESS : DN_MODIFY);
+                inotify_dentry_parent_queue_event(dentry,
+                                (type == READ) ? IN_ACCESS : IN_MODIFY, 0,
+                                dentry->d_name.name);
+                inotify_inode_queue_event (dentry->d_inode,
+                                (type == READ) ? IN_ACCESS : IN_MODIFY, 0, NULL);
+        }
         return ret;
 }
 

fs/super.c

@@ -38 +38 @@
 #include <linux/idr.h>
 #include <linux/kobject.h>
 #include <asm/uaccess.h>
+#include <linux/inotify.h>
 
 
 void get_filesystem(struct file_system_type *fs);
@@ -227 +228 @@
 
         if (root) {
                 sb->s_root = NULL;
+                inotify_super_block_umount(sb);
                 shrink_dcache_parent(root);
                 shrink_dcache_anon(&sb->s_anon);
                 dput(root);

include/linux/fs.h

@@ -27 +27 @@
 struct kstatfs;
 struct vm_area_struct;
 struct vfsmount;
+struct inotify_inode_data;
 
 /*
  * It's silly to have NR_OPEN bigger than NR_FILE, but you can change
@@ -473 +474 @@
         struct dnotify_struct   *i_dnotify; /* for directory notifications */
 #endif
 
+#ifdef CONFIG_INOTIFY
+        struct inotify_inode_data *inotify_data;
+#endif
+
         unsigned long           i_state;
         unsigned long           dirtied_when;   /* jiffies of first dirtying */
 
@@ -1353 +1358 @@
 extern int do_remount_sb(struct super_block *sb, int flags,
                          void *data, int force);
 extern sector_t bmap(struct inode *, sector_t);
-extern int setattr_mask(unsigned int);
+extern void setattr_mask(unsigned int, int *, u32 *);
 extern int notify_change(struct dentry *, struct iattr *);
 extern int permission(struct inode *, int, struct nameidata *);
 extern int generic_permission(struct inode *, int,

include/linux/inotify.h

@@ +1 @@
+/*
+ * Inode based directory notification for Linux
+ *
+ * Copyright (C) 2004 John McCutchan
+ */
+
+#ifndef _LINUX_INOTIFY_H
+#define _LINUX_INOTIFY_H
+
+#include <linux/types.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 {
+        __s32 wd;
+        __u32 mask;
+        __u32 cookie;
+        char filename[INOTIFY_FILENAME_MAX];
+};
+
+/*
+ * 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 */
+        __u32 mask;             /* event mask */
+};
+
+/* 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_WRITE          0x00000008      /* Writtable file was closed */
+#define IN_CLOSE_NOWRITE        0x00000010      /* Unwrittable file closed */
+#define IN_OPEN                 0x00000020      /* File was opened */
+#define IN_MOVED_FROM           0x00000040      /* File was moved from X */
+#define IN_MOVED_TO             0x00000080      /* File was moved to Y */
+#define IN_DELETE_SUBDIR        0x00000100      /* Subdir was deleted */ 
+#define IN_DELETE_FILE          0x00000200      /* Subfile was deleted */
+#define IN_CREATE_SUBDIR        0x00000400      /* Subdir was created */
+#define IN_CREATE_FILE          0x00000800      /* Subfile was created */
+#define IN_DELETE_SELF          0x00001000      /* Self was deleted */
+#define IN_UNMOUNT              0x00002000      /* Backing fs was unmounted */
+#define IN_Q_OVERFLOW           0x00004000      /* Event queued overflowed */
+#define IN_IGNORED              0x00008000      /* File was ignored */
+
+/* special flags */
+#define IN_ALL_EVENTS           0xffffffff      /* All the events */
+#define IN_CLOSE                (IN_CLOSE_WRITE | IN_CLOSE_NOWRITE)
+
+#define INOTIFY_IOCTL_MAGIC     'Q'
+#define INOTIFY_IOCTL_MAXNR     2
+
+#define INOTIFY_WATCH           _IOR(INOTIFY_IOCTL_MAGIC, 1, struct inotify_watch_request)
+#define INOTIFY_IGNORE          _IOR(INOTIFY_IOCTL_MAGIC, 2, int)
+
+#ifdef __KERNEL__
+
+#include <linux/dcache.h>
+#include <linux/fs.h>
+#include <linux/config.h>
+
+struct inotify_inode_data {
+        struct list_head watches;
+        __u32 watch_mask;
+        spinlock_t lock;
+        atomic_t count;
+};
+
+#ifdef CONFIG_INOTIFY
+
+extern void inotify_inode_queue_event(struct inode *, __u32, __u32,
+                                      const char *);
+extern void inotify_dentry_parent_queue_event(struct dentry *, __u32, __u32,
+                                              const char *);
+extern void inotify_super_block_umount(struct super_block *);
+extern void inotify_inode_is_dead(struct inode *);
+extern __u32 inotify_get_cookie(void);
+extern __u32 setattr_mask_inotify(unsigned int);
+
+/* this could be kstrdup if only we could add that to lib/string.c */
+static inline char * inotify_oldname_init(struct dentry *old_dentry)
+{
+        char *old_name;
+
+        old_name = kmalloc(strlen(old_dentry->d_name.name) + 1, GFP_KERNEL);
+        if (old_name)
+                strcpy(old_name, old_dentry->d_name.name);
+        return old_name;
+}
+
+static inline void inotify_oldname_free(const char *old_name)
+{
+        kfree(old_name);
+}
+
+#else
+
+static inline void inotify_inode_queue_event(struct inode *inode,
+                                             __u32 mask, __u32 cookie,
+                                             const char *filename)
+{
+}
+
+static inline void inotify_dentry_parent_queue_event(struct dentry *dentry,
+                                                     __u32 mask, __u32 cookie,
+                                                     const char *filename)
+{
+}
+
+static inline void inotify_super_block_umount(struct super_block *sb)
+{
+}
+
+static inline void inotify_inode_is_dead(struct inode *inode)
+{
+}
+
+static inline char * inotify_oldname_init(struct dentry *old_dentry)
+{
+        return NULL;
+}
+
+static inline __u32 inotify_get_cookie(void)
+{
+        return 0;
+}
+
+static inline void inotify_oldname_free(const char *old_name)
+{
+}
+
+static inline int setattr_mask_inotify(unsigned int ia_mask)
+{
+        return 0;
+}
+
+#endif  /* CONFIG_INOTIFY */
+
+#endif  /* __KERNEL __ */
+
+#endif  /* _LINUX_INOTIFY_H */

include/linux/miscdevice.h

@@ -2 +2 @@
 #define _LINUX_MISCDEVICE_H
 #include <linux/module.h>
 #include <linux/major.h>
+#include <linux/device.h>
 
 #define PSMOUSE_MINOR  1
 #define MS_BUSMOUSE_MINOR 2
@@ -32 +33 @@
 
 struct device;
 
-struct miscdevice 
-{
+struct miscdevice  {
         int minor;
         const char *name;
         struct file_operations *fops;
         struct list_head list;
         struct device *dev;
+        struct class_device *class;
         char devfs_name[64];
 };
 

include/linux/sched.h

@@ -353 +353 @@
         atomic_t processes;     /* How many processes does this user have? */
         atomic_t files;         /* How many open files does this user have? */
         atomic_t sigpending;    /* How many pending signals does this user have? */
+        atomic_t inotify_watches;       /* How many inotify watches does this user have? */
+        atomic_t inotify_devs;  /* How many inotify devs does this user have opened? */
         /* protected by mq_lock */
         unsigned long mq_bytes; /* How many bytes can be allocated to mqueue? */
         unsigned long locked_shm; /* How many pages of mlocked shm ? */

kernel/user.c

@@ -119 +119 @@
                 atomic_set(&new->processes, 0);
                 atomic_set(&new->files, 0);
                 atomic_set(&new->sigpending, 0);
+                atomic_set(&new->inotify_watches, 0);
+                atomic_set(&new->inotify_devs, 0);
 
                 new->mq_bytes = 0;
                 new->locked_shm = 0;