[patch] updated inotify
From: Robert Love
Date: Tue Sep 21 2004 - 16:13:02 EST
I have posted so many small patches recently that I wanted to just post
an updated inotify patch, with all of my changes merged in.
I also rediffed everything against 2.6.9-rc2.
And introduced an INOTIFY_FILENAME_MAX for the filename size, since
there were open coded 255's and 256's in inotify.c.
Additionally, I cleaned up some of the coding style to match the
kernel's. Don't know if you want this, but there it is.
Best,
Robert Love
inotify. the "i" stands for "awesome".
Signed-Off-By: Robert Love <rml@xxxxxxxxxx>
drivers/char/Makefile | 2
drivers/char/inotify.c | 988 ++++++++++++++++++++++++++++++++++++++++++++++++
fs/attr.c | 6
fs/inode.c | 1
fs/namei.c | 17
fs/open.c | 5
fs/read_write.c | 17
fs/super.c | 2
include/linux/fs.h | 4
include/linux/inotify.h | 93 ++++
10 files changed, 1127 insertions(+), 8 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 2004-09-21 16:58:57.529151952 -0400
@@ -0,0 +1,988 @@
+/*
+ * 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:
+ * use rb tree so looking up watcher by watcher descriptor is faster.
+ * dev->watch_count is incremented twice for each watcher
+ */
+
+#include <linux/bitops.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 /* maximum open devices */
+#define MAX_INOTIFY_DEV_WATCHERS 8192 /* max watchers per device */
+#define MAX_INOTIFY_QUEUED_EVENTS 256 /* max events we queue */
+
+#define INOTIFY_DEV_TIMER_TIME (jiffies + (HZ/4))
+
+static atomic_t watcher_count; /* < MAX_INOTIFY_DEVS */
+
+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)
+
+/*
+ * For each inotify device we need to keep a list of events queued on it,
+ * a list of inodes that we are watching and other stuff.
+ */
+struct inotify_device {
+ struct list_head events;
+ atomic_t event_count;
+ struct list_head watchers;
+ int watcher_count;
+ wait_queue_head_t wait;
+ struct timer_list timer;
+ char read_state;
+ spinlock_t lock;
+ unsigned long bitmask[MAX_INOTIFY_DEV_WATCHERS / BITS_PER_LONG];
+};
+
+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 */
+};
+
+/*
+ * 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)
+
+static int 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");
+ 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 error;
+}
+
+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))
+
+/* dev->lock == locked before calling */
+static void inotify_dev_queue_event (struct inotify_device *dev,
+ struct inotify_watcher *watcher,
+ int mask, const char *filename)
+{
+ struct inotify_kernel_event *kevent;
+
+ if (atomic_read(&dev->event_count) == MAX_INOTIFY_QUEUED_EVENTS) {
+ iprintk(INOTIFY_DEBUG_EVENTS,
+ "event queue for %p overflowed\n", dev);
+ return;
+ }
+
+ if (!event_and(mask, watcher->inode->watchers_mask) ||
+ !event_and(mask, watcher->mask))
+ return;
+
+ atomic_inc(&dev->event_count);
+
+ kevent = kernel_event (watcher->wd, mask, filename);
+
+ if (!kevent)
+ iprintk(INOTIFY_DEBUG_EVENTS,
+ "failed to queue event %x for %p\n", mask, dev);
+
+ list_add_tail(&kevent->list, &dev->events);
+
+ iprintk(INOTIFY_DEBUG_EVENTS, "queued event %x for %p\n", mask, dev);
+}
+
+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);
+ atomic_dec(&dev->event_count);
+
+ delete_kernel_event (kevent);
+
+ iprintk(INOTIFY_DEBUG_EVENTS, "dequeued event on %p\n", dev);
+}
+
+static int inotify_dev_get_wd (struct inotify_device *dev)
+{
+ int wd;
+
+ wd = -1;
+
+ if (!dev)
+ return -1;
+
+ if (dev->watcher_count == MAX_INOTIFY_DEV_WATCHERS)
+ return -1;
+
+ dev->watcher_count++;
+
+ wd = find_first_zero_bit (dev->bitmask, MAX_INOTIFY_DEV_WATCHERS);
+
+ set_bit (wd, dev->bitmask);
+
+ return wd;
+}
+
+static int inotify_dev_put_wd (struct inotify_device *dev, int wd)
+{
+ if (!dev || wd < 0)
+ return -1;
+
+ dev->watcher_count--;
+
+ clear_bit (wd, dev->bitmask);
+
+ return 0;
+}
+
+
+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);
+ watcher = NULL;
+ return watcher;
+ }
+
+ watcher_object_count++;
+ return watcher;
+}
+
+/* Must be called with dev->lock held */
+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--;
+}
+
+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->watcher_count == MAX_INOTIFY_DEV_WATCHERS) {
+ error = -ENOSPC;
+ goto out;
+ }
+ list_add(&watcher->d_list, &dev->watchers);
+
+out:
+ return error;
+}
+
+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;
+}
+
+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_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);
+
+/* 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;
+ event_count = 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_irq(&dev->lock);
+
+ add_wait_queue(&dev->wait, &wait);
+repeat:
+ if (signal_pending(current)) {
+ spin_unlock_irq (&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_irq (&dev->lock);
+ schedule ();
+ spin_lock_irq (&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_irq(&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;
+
+ dev = (struct inotify_device *) data;
+
+ if (!dev)
+ return;
+
+ /* reset the timer */
+ mod_timer(&dev->timer, INOTIFY_DEV_TIMER_TIME);
+
+ /* wake up anything waiting on poll */
+ 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;
+ memset(dev->bitmask, 0, MAX_INOTIFY_DEV_WATCHERS);
+
+ INIT_LIST_HEAD(&dev->events);
+ INIT_LIST_HEAD(&dev->watchers);
+ init_timer(&dev->timer);
+ init_waitqueue_head(&dev->wait);
+
+ atomic_set(&dev->event_count, 0);
+ dev->watcher_count = 0;
+ dev->lock = SPIN_LOCK_UNLOCKED;
+ dev->read_state = 0;
+
+ file->private_data = dev;
+
+ dev->timer.data = (unsigned long) dev;
+ dev->timer.function = inotify_dev_timer;
+ dev->timer.expires = INOTIFY_DEV_TIMER_TIME;
+
+ 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);
+}
+
+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)
+{
+ if (file->private_data) {
+ struct inotify_device *dev;
+
+ dev = (struct inotify_device *) 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;
+
+ err = find_inode (request->dirname, &inode);
+
+ if (err)
+ 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: %d\n", atomic_read(&dev->event_count));
+ printk (KERN_ALERT "inotify watch_count: %d\n", dev->watcher_count);
+
+ 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 wid;
+
+ 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(&wid, (void *)arg, sizeof(int))) {
+ err = -EFAULT;
+ goto out;
+ }
+ err = inotify_ignore(dev, wid);
+ 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, // automatic
+ .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_ALERT "inotify 0.9.2 minor=%d\n", inotify_device.minor);
+out:
+ return ret;
+}
+
+static void inotify_exit (void)
+{
+ kmem_cache_destroy (kevent_cache);
+ kmem_cache_destroy (watcher_cache);
+ misc_deregister (&inotify_device);
+ printk(KERN_ALERT "inotify shutdown ec=%d wc=%d ic=%d\n",
+ event_object_count, watcher_object_count, inode_ref_count);
+}
+
+MODULE_AUTHOR("John McCutchan <ttb@xxxxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Inode event driver");
+MODULE_LICENSE("GPL");
+
+module_init (inotify_init);
+module_exit (inotify_exit);
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 2004-09-20 17:31:01.000000000 -0400
@@ -7,7 +7,7 @@
#
FONTMAPFILE = cp437.uni
-obj-y += mem.o random.o tty_io.o n_tty.o tty_ioctl.o
+obj-y += mem.o random.o tty_io.o n_tty.o tty_ioctl.o inotify.o
obj-$(CONFIG_LEGACY_PTYS) += pty.o
obj-$(CONFIG_UNIX98_PTYS) += pty.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 2004-09-20 17:31:01.000000000 -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>
@@ -185,8 +186,11 @@
}
if (!error) {
unsigned long dn_mask = setattr_mask(ia_valid);
- if (dn_mask)
+ if (dn_mask) {
dnotify_parent(dentry, dn_mask);
+ inotify_inode_queue_event (dentry->d_inode, dn_mask, NULL);
+ inotify_dentry_parent_queue_event (dentry, dn_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 2004-09-20 17:31:01.000000000 -0400
@@ -114,6 +114,7 @@
if (inode) {
struct address_space * const mapping = &inode->i_data;
+ INIT_LIST_HEAD (&inode->watchers);
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 2004-09-20 17:31:01.000000000 -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, 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, 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, dentry->d_name.name);
security_inode_post_mkdir(dir,dentry, mode);
}
return error;
@@ -1708,6 +1712,8 @@
up(&dentry->d_inode->i_sem);
if (!error) {
inode_dir_notify(dir, DN_DELETE);
+ inotify_inode_queue_event(dir, IN_DELETE, dentry->d_name.name);
+ inotify_inode_queue_event(dentry->d_inode, IN_DELETE, NULL);
d_delete(dentry);
}
dput(dentry);
@@ -1780,8 +1786,9 @@
/* 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, dentry->d_name.name);
+ d_delete(dentry);
}
return error;
}
@@ -1858,6 +1865,7 @@
error = dir->i_op->symlink(dir, dentry, oldname);
if (!error) {
inode_dir_notify(dir, DN_CREATE);
+ inotify_inode_queue_event(dir, IN_CREATE, dentry->d_name.name);
security_inode_post_symlink(dir, dentry, oldname);
}
return error;
@@ -1931,6 +1939,7 @@
up(&old_dentry->d_inode->i_sem);
if (!error) {
inode_dir_notify(dir, DN_CREATE);
+ inotify_inode_queue_event(dir, IN_CREATE, new_dentry->d_name.name);
security_inode_post_link(old_dentry, dir, new_dentry);
}
return error;
@@ -2120,12 +2129,14 @@
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_RENAME, 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 2004-09-20 17:31:02.000000000 -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 2004-09-20 17:31:02.000000000 -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 2004-09-20 17:31:02.000000000 -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 2004-09-20 17:31:02.000000000 -0400
@@ -462,6 +462,10 @@
unsigned long i_dnotify_mask; /* Directory notify events */
struct dnotify_struct *i_dnotify; /* for directory notifications */
+ struct list_head watchers;
+ unsigned long watchers_mask;
+ int watcher_count;
+
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 2004-09-21 16:58:51.315096632 -0400
@@ -0,0 +1,93 @@
+/*
+ * Inode based directory notification for Linux
+ *
+ * Copyright (C) 2004 John McCutchan
+ *
+ * Signed-off-by: John McCutchan ttb@xxxxxxxxxxxxxxxx
+ */
+
+#ifndef _LINUX_INOTIFY_H
+#define _LINUX_INOTIFY_H
+
+#include <linux/limits.h>
+
+#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, and so on ...
+ *
+ * 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;
+ 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_CREATE 0x00000004 /* File was created */
+#define IN_DELETE 0x00000008 /* File was deleted */
+#define IN_RENAME 0x00000010 /* File was renamed */
+#define IN_UNMOUNT 0x00000080 /* Backing filesystem was unmounted */
+#define IN_CLOSE 0x00000100 /* File was closed */
+#define IN_OPEN 0x00000200 /* File was opened */
+
+/* the following are legal, but not yet implemented, events */
+#define IN_ATTRIB 0x00000020 /* File changed attributes */
+#define IN_MOVE 0x00000040 /* File was moved */
+
+/* special flags */
+#define IN_IGNORED 0x00000400 /* File was ignored */
+#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>
+
+/* Adds events to all watchers on inode that are interested in mask */
+void inotify_inode_queue_event (struct inode *inode, unsigned long mask,
+ const char *filename);
+
+/* Same as above but uses dentry's inode */
+void inotify_dentry_parent_queue_event (struct dentry *dentry,
+ unsigned long mask, const char *filename);
+
+/* This will remove all watchers from all inodes on the superblock */
+void inotify_super_block_umount (struct super_block *sb);
+
+#endif /* __KERNEL __ */
+
+#endif /* _LINUX_INOTIFY_H */