[patch] inotify: remove timer

[Robert Love]

On Sun, 2004-09-26 at 22:02 -0400, John McCutchan wrote:

John,

> Announcing the release of inotify 0.10.0. 
> Attached is a patch to 2.6.8.1.

Attached patch removes dev->timer and instead wakes up waiting tasks in
inotify_dev_queue_event().

I'd like you to go over it, make sure this works the same and makes
sense.  It needs a good testing before merged.

	Robert Love

Remove dev->timer

Signed-Off-By: Robert Love <rml@xxxxxxxxxx>

 drivers/char/inotify.c |   32 +++++++-------------------------
 1 files changed, 7 insertions(+), 25 deletions(-)

diff -urN linux-inotify/drivers/char/inotify.c linux/drivers/char/inotify.c
--- linux-inotify/drivers/char/inotify.c	2004-09-27 16:40:37.000000000 -0400
+++ linux/drivers/char/inotify.c	2004-09-28 13:43:07.924958624 -0400
@@ -63,10 +63,14 @@
  *
  * 'bitmask' holds one bit for each possible watcher descriptor: a set bit
  * implies that the given WD is valid, unset implies it is not.
+ *
+ * This structure is protected by 'lock'.  Lock ordering:
+ *	dev->lock
+ *		dev->wait->lock
+ * FIXME: Define lock ordering wrt inode and dentry locking!
  */
 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;
@@ -248,9 +252,11 @@
 		return;
 	}
 
+	/* queue the event and wake up anyone waiting */
 	list_add_tail(&kevent->list, &dev->events);
 	iprintk(INOTIFY_DEBUG_EVENTS,
 		"queued event %x for %p\n", kevent->event.mask, dev);
+	wake_up_interruptible(&dev->wait);
 }
 
 /*
@@ -747,22 +753,6 @@
 	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;
@@ -780,7 +770,6 @@
 
 	INIT_LIST_HEAD(&dev->events);
 	INIT_LIST_HEAD(&dev->watchers);
-	init_timer(&dev->timer);
 	init_waitqueue_head(&dev->wait);
 
 	dev->event_count = 0;
@@ -789,12 +778,6 @@
 
 	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;
@@ -825,7 +808,6 @@
 	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);