[PATCH] dnotify

[Stephen Rothwell]

Hi Marcelo, Linus,

The following patch makes directory notifications per thread group instead
of per process tree as they are now.  This means, in particular, that if
a child closes a file descriptor that has a directory open with notifies
enabled, the notification will not be removed.

Thanks to Andrea for the push in the right direction.

Patch against 2.4.19-pre3, but also applies to 2.5.6 with a small offset.
-- 
Cheers,
Stephen Rothwell                    [e-mail]
http://www.canb.auug.org.au/~sfr/

diff -ruN 2.4.19-pre3/fs/dnotify.c 2.4.19-pre3-notify/fs/dnotify.c
--- 2.4.19-pre3/fs/dnotify.c	Wed Nov  8 18:27:57 2000
+++ 2.4.19-pre3-notify/fs/dnotify.c	Tue Mar 12 12:02:15 2002
@@ -1,7 +1,7 @@
 /*
  * Directory notifications for Linux.
  *
- * Copyright (C) 2000 Stephen Rothwell
+ * Copyright (C) 2000,2001,2002 Stephen Rothwell
  *
  * 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
@@ -59,7 +59,7 @@
 	write_lock(&dn_lock);
 	prev = &inode->i_dnotify;
 	for (odn = *prev; odn != NULL; prev = &odn->dn_next, odn = *prev)
-		if (odn->dn_filp == filp)
+		if ((odn->dn_owner == current->files) && (odn->dn_filp == filp))
 			break;
 	if (odn != NULL) {
 		if (turning_off) {
@@ -82,6 +82,7 @@
 	dn->dn_mask = arg;
 	dn->dn_fd = fd;
 	dn->dn_filp = filp;
+	dn->dn_owner = current->files;
 	inode->i_dnotify_mask |= arg & ~DN_MULTISHOT;
 	dn->dn_next = inode->i_dnotify;
 	inode->i_dnotify = dn;
diff -ruN 2.4.19-pre3/include/linux/dnotify.h 2.4.19-pre3-notify/include/linux/dnotify.h
--- 2.4.19-pre3/include/linux/dnotify.h	Wed Mar  6 16:08:12 2002
+++ 2.4.19-pre3-notify/include/linux/dnotify.h	Tue Mar 12 11:23:07 2002
@@ -11,6 +11,7 @@
 						   see linux/fcntl.h */
 	int			dn_fd;
 	struct file *		dn_filp;
+	fl_owner_t		dn_owner;
 };
 
 #define DNOTIFY_MAGIC	0x444E4F54