[gamin] [RFC][PATCH] inotify 0.14
- From: John McCutchan <ttb tentacle dhs org>
- To: linux-kernel vger kernel org, gamin-list gnome org, rml ximian com, viro parcelfarce linux theplanet co uk, akpm osdl org, bkonrath redhat com, greg kroah com
- Cc:
- Subject: [gamin] [RFC][PATCH] inotify 0.14
- Date: Thu, 14 Oct 2004 22:44:32 -0400
Hello,
Here is release 0.14.0 of inotify. Attached is a patch to 2.6.8.1
--New in this version--
-fix compiling without inotify (rml)
-zero out kevent structure (rml)
-setattr_mask -> setattr_mask_dnotify (rml)
-setattr_mask_inotify moved to inotify.c (rml)
-fixup setattr_mask return values (rml)
-always define wd as s32 (rml)
-fix dentry leak bug (rml)
-misc cleanups (rml,me)
-implement security when attempting to watch something (me)
-got rid of debug code (me)
-merged setattr_mask_inotify/dnotify (me)
John McCutchan
Release notes:
--Why Not dnotify and Why inotify (By Robert Love)--
Everyone seems quick to deride the blunder known as "dnotify" and
applaud a
replacement, any replacement, man anything but that current mess, but in
the
name of fairness I present my treatise on why dnotify is what one might
call
not good:
* dnotify requires the opening of one fd per each directory that you
intend to
watch.
o The file descriptor pins the directory, disallowing the backing
device to be unmounted, which absolutely wrecks havoc with removable
media.
o Watching many directories results in many open file descriptors,
possibly hitting a per-process fd limit.
* dnotify is directory-based. You only learn about changes to
directories.
Sure, a change to a file in a directory affects the directory, but you
are
then forced to keep a cache of stat structures around to compare
things in
order to find out which file.
* dnotify's interface to user-space is awful.
o dnotify uses signals to communicate with user-space.
o Specifically, dnotify uses SIGIO.
o But then you can pick a different signal! So by "signals," I really
meant you need to use real-time signals if you want to queue the
events.
* dnotify basically ignores any problems that would arise in the VFS
from hard
links.
* Rumor is that the "d" in "dnotify" does not stand for "directory" but
for
"suck."
A suitable replacement is "inotify." And now, my tract on what inotify
brings
to the table:
* inotify's interface is a device node, not SIGIO.
o You open only a single fd, to the device node. No more pinning
directories or opening a million file descriptors.
o Usage is nice: open the device, issue simple commands via ioctl(),
and then block on the device. It returns events when, well, there are
events to be returned.
o You can select() on the device node and so it integrates with main
loops like coffee mixed with vanilla milkshake.
* inotify has an event that says "the filesystem that the item you were
watching is on was unmounted" (this is particularly cool).
* inotify can watch directories or files.
* The "i" in inotify does not stand for "suck" but for "inode" -- the
logical
choice since inotify is inode-based.
--COMPLEXITY--
I have been asked what the complexity of inotify is. Inotify has
2 path codes where complexity could be an issue:
Adding a watch to a device
This code has to check if the inode is already being watched
by the device, this is O(1) since the maximum number of
devices is limited to 8.
Removing a watch from a device
This code has to do a search of all watches on the device to
find the watch descriptor that is being asked to remove.
This involves a linear search, but should not really be an issue
because it is limited to 8192 entries. If this does turn in to
a concern, I would replace the list of watches on the device
with a sorted binary tree, so that the search could be done
very quickly.
In the near future this will be based on idr, and the complexity
will be O(logn)
The calls to inotify from the VFS code has a complexity of O(1) so
inotify does not affect the speed of VFS operations.
--MEMORY USAGE--
The inotify data structures are light weight:
inotify watch is 40 bytes
inotify device is 68 bytes
inotify event is 272 bytes
So assuming a device has 8192 watches, the structures are only going
to consume 320KB of memory. With a maximum number of 8 devices allowed
to exist at a time, this is still only 2.5 MB
Each device can also have 256 events queued at a time, which sums to
68KB per device. And only .5 MB if all devices are opened and have
a full event queue.
So approximately 3 MB of memory are used in the rare case of
everything open and full.
Each inotify watch pins the inode of a directory/file in memory,
the size of an inode is different per file system but lets assume
that it is 512 byes.
So assuming the maximum number of global watches are active, this would
pin down 32 MB of inodes in the inode cache. Again not a problem
on a modern system.
On smaller systems, the maximum watches / events could be lowered
to provide a smaller foot print.
Keep in mind that this is an absolute worst case memory analysis.
In reality it will most likely cost approximately 5MB.
--HOWTO USE--
Inotify is a character device that when opened offers 2 IOCTL's.
(It actually has 4 but the other 2 are used for debugging)
INOTIFY_WATCH:
Which takes a path and event mask and returns a unique
(to the instance of the driver) integer (wd [watch descriptor]
from here on) that is a 1:1 mapping to the path passed.
What happens is inotify gets the inode (and ref's the inode)
for the path and adds a inotify_watch structure to the inodes
list of watches. If this instance of the driver is already
watching the path, the event mask will be updated and
the original wd will be returned.
INOTIFY_IGNORE:
Which takes an integer (that you got from INOTIFY_WATCH)
representing a wd that you are not interested in watching
anymore. This will:
send an IGNORE event to the device
remove the inotify_watch structure from the device and
from the inode and unref the inode.
After you are watching 1 or more paths, you can read from the fd
and get events. The events are struct inotify_event. If you are
watching a directory and something happens to a file in the directory
the event will contain the filename (just the filename not the full
path).
-- EVENTS --
IN_ACCESS - Sent when file is accessed.
IN_MODIFY - Sent when file is modified.
IN_ATTRIB - Sent when file is chmod'ed.
IN_CLOSE_WRITE - Sent when file is closed and was opened for writing.
IN_CLOSE_NOWRITE - Sent when file is closed but was not opened for
writing.
IN_CLOSE - either of the two above events.
IN_OPEN - Sent when file is opened.
IN_MOVED_FROM - Sent to the source folder of a move.
IN_MOVED_TO - Sent to the destination folder of a move.
IN_DELETE_SUBDIR - Sent when a sub directory is deleted. (When watching
parent)
IN_DELETE_FILE - Sent when a file is deleted. (When watching parent)
IN_CREATE_SUBDIR - Sent when a sub directory is created. (When watching
parent)
IN_CREATE_FILE - Sent when a file is created. (When watching parent)
IN_DELETE_SELF - Sent when file is deleted.
IN_UNMOUNT - Sent when the filesystem is being unmounted.
IN_Q_OVERFLOW - Sent when your event queue has over flowed.
The MOVED_FROM/MOVED_TO events are always sent in pairs.
MOVED_FROM/MOVED_TO
is also sent when a file is renamed. The cookie field in the event pairs
up MOVED_FROM/MOVED_TO events. These two events are not guaranteed to be
successive in the event stream. You must rely on the cookie to pair
them up. (Note, the cookie is not sent yet.)
If you aren't watching the source and destination folders in a MOVE.
You will only get MOVED_TO or MOVED_FROM. In this case, MOVED_TO
is equivelent to a CREATE and MOVED_FROM is equivelent to a DELETE.
--KERNEL CHANGES--
inotify char device driver.
Adding calls to inotify_inode_queue_event and
inotify_dentry_parent_queue_event from VFS operations.
Dnotify has the same function calls. The complexity of the VFS
operations is not affected because inotify_*_queue_event is O(1).
Adding a call to inotify_super_block_umount from
generic_shutdown_superblock
inotify_super_block_umount consists of this:
find all of the inodes that are on the super block being shut down,
sends each watch on each inode the UNMOUNT and IGNORED event
removes the watch structures from each instance of the device driver
and each inode.
unref's the inode.
--- clean/linux/drivers/char/inotify.c 1969-12-31 19:00:00.000000000 -0500
+++ linux/drivers/char/inotify.c 2004-10-11 21:51:53.000000000 -0400
@@ -0,0 +1,932 @@
+/*
+ * 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:
+ * unmount events don't get sent if filesystem is mounted in two places
+ * dynamically allocate event filename
+ */
+
+#include <linux/bitmap.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/namei.h>
+#include <linux/poll.h>
+#include <linux/miscdevice.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/writeback.h>
+#include <linux/inotify.h>
+
+#define MAX_INOTIFY_DEVS 8 /* max open inotify devices */
+#define MAX_INOTIFY_DEV_WATCHES 8192 /* max total watches */
+#define MAX_INOTIFY_QUEUED_EVENTS 256 /* max events queued on the dev */
+
+static atomic_t watch_count;
+static atomic_t inotify_cookie;
+static kmem_cache_t *watch_cachep;
+static kmem_cache_t *event_cachep;
+static kmem_cache_t *inode_data_cachep;
+
+/*
+ * struct inotify_device - represents an open instance of an inotify device
+ *
+ * For each inotify device, we need to keep track of the events queued on it,
+ * a list of the inodes that we are watching, and so on.
+ *
+ * 'bitmask' holds one bit for each possible watch descriptor: a set bit
+ * implies that the given WD is valid, unset implies it is not.
+ *
+ * This structure is protected by 'lock'. Lock ordering:
+ *
+ * inode->i_lock
+ * dev->lock
+ * dev->wait->lock
+ *
+ * FIXME: Look at replacing i_lock with i_sem.
+ */
+struct inotify_device {
+ DECLARE_BITMAP(bitmask, MAX_INOTIFY_DEV_WATCHES);
+ wait_queue_head_t wait;
+ struct list_head events;
+ struct list_head watches;
+ spinlock_t lock;
+ unsigned int event_count;
+ unsigned int nr_watches;
+};
+
+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 */
+ struct list_head u_list; /* unmount list */
+};
+#define inotify_watch_d_list(pos) list_entry((pos), struct inotify_watch, d_list)
+#define inotify_watch_i_list(pos) list_entry((pos), struct inotify_watch, i_list)
+#define inotify_watch_u_list(pos) list_entry((pos), struct inotify_watch, u_list)
+
+/*
+ * A list of these is attached to each instance of the driver
+ * when the drivers read() gets called, this list is walked and
+ * all events that can fit in the buffer get delivered
+ */
+struct inotify_kernel_event {
+ struct list_head list;
+ struct inotify_event event;
+};
+
+/*
+ * 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) {
+ inode = ERR_PTR(error);
+ goto out;
+ }
+
+ inode = nd.dentry->d_inode;
+
+ /* you can only watch an inode if you have read permissions on it */
+ error = vfs_permission(inode, MAY_READ);
+ if (error) {
+ inode = ERR_PTR(error);
+ goto release_and_out;
+ }
+
+ __iget(inode);
+release_and_out:
+ path_release(&nd);
+out:
+ return inode;
+}
+
+static inline void unref_inode(struct inode *inode)
+{
+ iput(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)
+ goto out;
+
+ /* 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';
+
+out:
+ 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))
+#define inotify_dev_has_events(dev) (!list_empty(&dev->events))
+
+/* 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 > MAX_INOTIFY_QUEUED_EVENTS)
+ return;
+
+ /* the queue has just overflowed and we need to notify user space */
+ if (dev->event_count == MAX_INOTIFY_QUEUED_EVENTS) {
+ dev->event_count++;
+ kevent = kernel_event(-1, IN_Q_OVERFLOW, cookie, NULL);
+ goto add_event_to_queue;
+ }
+
+ if (!event_and(mask, watch->inode->inotify_data->watch_mask) ||
+ !event_and(mask, watch->mask))
+ return;
+
+ dev->event_count++;
+ kevent = kernel_event(watch->wd, mask, cookie, filename);
+
+add_event_to_queue:
+ if (!kevent) {
+ dev->event_count--;
+ return;
+ }
+
+ /* queue the event and wake up anyone waiting */
+ list_add_tail(&kevent->list, &dev->events);
+ wake_up_interruptible(&dev->wait);
+}
+
+/*
+ * inotify_dev_event_dequeue - destroy an event on the given device
+ *
+ * Caller must hold dev->lock.
+ */
+static void inotify_dev_event_dequeue(struct inotify_device *dev)
+{
+ struct inotify_kernel_event *kevent;
+
+ if (!inotify_dev_has_events(dev))
+ return;
+
+ kevent = inotify_dev_get_event(dev);
+ list_del(&kevent->list);
+ dev->event_count--;
+ delete_kernel_event(kevent);
+
+}
+
+/*
+ * inotify_dev_get_wd - returns the next WD for use by the given dev
+ *
+ * Caller must hold dev->lock before calling.
+ */
+static int inotify_dev_get_wd(struct inotify_device *dev)
+{
+ s32 wd;
+
+ if (!dev || dev->nr_watches == MAX_INOTIFY_DEV_WATCHES)
+ return -1;
+
+ dev->nr_watches++;
+ wd = find_first_zero_bit(dev->bitmask, MAX_INOTIFY_DEV_WATCHES);
+ set_bit(wd, dev->bitmask);
+
+ return wd;
+}
+
+/*
+ * inotify_dev_put_wd - release the given WD on the given device
+ *
+ * Caller must hold dev->lock.
+ */
+static int inotify_dev_put_wd(struct inotify_device *dev, s32 wd)
+{
+ if (!dev || wd < 0)
+ return -1;
+
+ dev->nr_watches--;
+ clear_bit(wd, dev->bitmask);
+
+ 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);
+ INIT_LIST_HEAD(&watch->u_list);
+
+ spin_lock(&dev->lock);
+ watch->wd = inotify_dev_get_wd(dev);
+ spin_unlock(&dev->lock);
+
+ if (watch->wd < 0) {
+ 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.
+ */
+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;
+}
+
+static struct inotify_watch *dev_find_wd(struct inotify_device *dev, s32 wd)
+{
+ struct inotify_watch *watch;
+
+ list_for_each_entry(watch, &dev->watches, d_list) {
+ if (watch->wd == wd)
+ return watch;
+ }
+
+ return NULL;
+}
+
+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;
+
+ if (dev_find_wd (dev, watch->wd))
+ return -EINVAL;
+
+ if (dev->nr_watches == MAX_INOTIFY_DEV_WATCHES)
+ return -ENOSPC;
+
+ 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(&watch->d_list);
+
+ return 0;
+}
+
+void inode_update_watch_mask(struct inode *inode)
+{
+ struct inotify_watch *watch;
+ u32 new_mask;
+
+ if (!inode->inotify_data)
+ return;
+
+ new_mask = 0;
+ list_for_each_entry(watch, &inode->inotify_data->watches, i_list)
+ new_mask |= watch->mask;
+
+ inode->inotify_data->watch_mask = new_mask;
+}
+
+/*
+ * 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)
+{
+ if (!inode || !watch || inode_find_dev(inode, watch->dev))
+ return -EINVAL;
+
+ /*
+ * This inode doesn't have an inotify_data structure attached to it
+ */
+ if (!inode->inotify_data) {
+ inode->inotify_data = kmem_cache_alloc(inode_data_cachep,
+ GFP_ATOMIC);
+ INIT_LIST_HEAD(&inode->inotify_data->watches);
+ inode->inotify_data->watch_mask = 0;
+ inode->inotify_data->watch_count = 0;
+ }
+ list_add(&watch->i_list, &inode->inotify_data->watches);
+ inode->inotify_data->watch_count++;
+ inode_update_watch_mask(inode);
+
+ return 0;
+}
+
+static int inode_rm_watch(struct inode *inode,
+ struct inotify_watch *watch)
+{
+ if (!inode || !watch || !inode->inotify_data)
+ return -EINVAL;
+
+ list_del(&watch->i_list);
+ inode->inotify_data->watch_count--;
+
+ if (!inode->inotify_data->watch_count) {
+ kmem_cache_free(inode_data_cachep, inode->inotify_data);
+ inode->inotify_data = NULL;
+ }
+
+ inode_update_watch_mask(inode);
+
+ return 0;
+}
+
+/* Kernel API */
+
+void inotify_inode_queue_event(struct inode *inode, u32 mask, u32 cookie,
+ const char *filename)
+{
+ struct inotify_watch *watch;
+
+ if (!inode->inotify_data)
+ return;
+
+ spin_lock(&inode->i_lock);
+
+ 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);
+ }
+
+ spin_unlock(&inode->i_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()
+{
+ atomic_inc(&inotify_cookie);
+
+ return atomic_read(&inotify_cookie);
+}
+EXPORT_SYMBOL_GPL(inotify_get_cookie);
+
+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(&inode->i_lock);
+ 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);
+ list_del(&watch->u_list);
+
+ delete_watch(dev, watch);
+ spin_unlock(&dev->lock);
+ spin_unlock(&inode->i_lock);
+
+ unref_inode(inode);
+}
+
+static void process_umount_list(struct list_head *umount)
+{
+ struct inotify_watch *watch, *next;
+
+ list_for_each_entry_safe(watch, next, umount, u_list)
+ ignore_helper(watch, IN_UNMOUNT);
+}
+
+/*
+ * build_umount_list - build a list of watches affected by an unmount.
+ *
+ * Caller must hold inode_lock.
+ */
+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_watch *watch;
+
+ if (inode->i_sb != sb)
+ continue;
+
+ if (!inode->inotify_data)
+ continue;
+
+ spin_lock(&inode->i_lock);
+
+ list_for_each_entry(watch, &inode->inotify_data->watches,
+ i_list)
+ list_add(&watch->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);
+
+/*
+ * inotify_inode_is_dead - an inode has been deleted, cleanup any watches
+ *
+ * FIXME: Callers need to always hold inode->i_lock.
+ */
+void inotify_inode_is_dead(struct inode *inode)
+{
+ struct inotify_watch *watch, *next;
+ struct inotify_inode_data *data;
+
+ data = inode->inotify_data;
+ if (!data)
+ return;
+
+ list_for_each_entry_safe(watch, next, &data->watches, i_list)
+ ignore_helper(watch, 0);
+}
+EXPORT_SYMBOL_GPL(inotify_inode_is_dead);
+
+/*
+ * setattr_mask_inotify - return the desired event mask based on the given
+ * attribute bitmask.
+ */
+u32 setattr_mask_inotify(unsigned int ia_valid)
+{
+ u32 mask = 0;
+
+ if (ia_valid & ATTR_UID)
+ mask |= IN_ATTRIB;
+ if (ia_valid & ATTR_GID)
+ mask |= IN_ATTRIB;
+ if (ia_valid & ATTR_SIZE)
+ mask |= IN_MODIFY;
+ /* both times implies a utime(s) call */
+ if ((ia_valid & (ATTR_ATIME|ATTR_MTIME)) == (ATTR_ATIME|ATTR_MTIME))
+ mask |= IN_ATTRIB;
+ else if (ia_valid & ATTR_ATIME)
+ mask |= IN_ACCESS;
+ else if (ia_valid & ATTR_MTIME)
+ mask |= IN_MODIFY;
+ if (ia_valid & ATTR_MODE)
+ mask |= IN_ATTRIB;
+ return mask;
+}
+EXPORT_SYMBOL(setattr_mask_inotify);
+
+/* 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 *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;
+
+ if (atomic_read(&watch_count) == MAX_INOTIFY_DEVS)
+ return -ENODEV;
+
+ atomic_inc(&watch_count);
+
+ dev = kmalloc(sizeof(struct inotify_device), GFP_KERNEL);
+ if (!dev)
+ return -ENOMEM;
+
+ bitmap_zero(dev->bitmask, MAX_INOTIFY_DEV_WATCHES);
+
+ INIT_LIST_HEAD(&dev->events);
+ INIT_LIST_HEAD(&dev->watches);
+ init_waitqueue_head(&dev->wait);
+
+ dev->event_count = 0;
+ dev->nr_watches = 0;
+ dev->lock = SPIN_LOCK_UNLOCKED;
+
+ file->private_data = dev;
+
+ return 0;
+}
+
+/*
+ * 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);
+ kfree(dev);
+
+ atomic_dec(&watch_count);
+ return 0;
+}
+
+static int inotify_watch(struct inotify_device *dev,
+ struct inotify_watch_request *request)
+{
+ struct inode *inode;
+ struct inotify_watch *watch;
+
+ inode = find_inode(request->dirname);
+ if (IS_ERR(inode))
+ return PTR_ERR(inode);
+
+ spin_lock(&inode->i_lock);
+ 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);
+ spin_unlock(&inode->i_lock);
+ unref_inode(inode);
+
+ return owatch->wd;
+ }
+
+ spin_unlock(&dev->lock);
+ spin_unlock(&inode->i_lock);
+
+ watch = create_watch(dev, request->mask, inode);
+ if (!watch) {
+ unref_inode(inode);
+ return -ENOSPC;
+ }
+
+ spin_lock(&inode->i_lock);
+ spin_lock(&dev->lock);
+
+ /* We can't add anymore watches to this device */
+ if (inotify_dev_add_watch(dev, watch) == -ENOSPC) {
+ delete_watch(dev, watch);
+ spin_unlock(&dev->lock);
+ spin_unlock(&inode->i_lock);
+ unref_inode(inode);
+ return -ENOSPC;
+ }
+
+ inode_add_watch(inode, watch);
+
+ spin_unlock(&dev->lock);
+ spin_unlock(&inode->i_lock);
+
+ return watch->wd;
+}
+
+static int inotify_ignore(struct inotify_device *dev, s32 wd)
+{
+ struct inotify_watch *watch;
+
+ watch = dev_find_wd(dev, wd);
+ 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;
+ 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_watch(dev, &request);
+ case INOTIFY_IGNORE:
+ if (copy_from_user(&wd, p, sizeof (wd)))
+ return -EFAULT;
+ return inotify_ignore(dev, wd);
+ 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)
+{
+ int ret;
+
+ ret = misc_register(&inotify_device);
+ if (ret)
+ return ret;
+
+ atomic_set(&watch_count, 0);
+ 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 init: minor=%d\n", inotify_device.minor);
+
+ return 0;
+}
+
+module_init(inotify_init);
--- clean/linux/include/linux/inotify.h 1969-12-31 19:00:00.000000000 -0500
+++ linux/include/linux/inotify.h 2004-10-07 10:27:55.000000000 -0400
@@ -0,0 +1,154 @@
+/*
+ * 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;
+ int watch_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 */
--- clean/linux/include/linux/fs.h 2004-08-14 06:55:09.000000000 -0400
+++ linux/include/linux/fs.h 2004-10-14 22:21:06.000000000 -0400
@@ -27,6 +27,7 @@
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
@@ -61,7 +62,7 @@
};
extern struct inodes_stat_t inodes_stat;
-extern int leases_enable, dir_notify_enable, lease_break_time;
+extern int leases_enable, lease_break_time;
#define NR_FILE 8192 /* this can well be larger on a larger system */
#define NR_RESERVED_FILES 10 /* reserved for root */
@@ -455,8 +456,14 @@
struct cdev *i_cdev;
int i_cindex;
+#ifdef CONFIG_DNOTIFY
unsigned long i_dnotify_mask; /* Directory notify events */
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 */
@@ -1315,7 +1322,7 @@
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 vfs_permission(struct inode *, int);
--- clean/linux/fs/super.c 2004-08-14 06:55:22.000000000 -0400
+++ linux/fs/super.c 2004-10-06 15:49:28.000000000 -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);
--- clean/linux/fs/read_write.c 2004-08-14 06:55:35.000000000 -0400
+++ linux/fs/read_write.c 2004-10-06 16:22:39.000000000 -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 +217,14 @@
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);
+ }
}
}
@@ -260,8 +267,14 @@
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);
+ }
}
}
@@ -493,9 +506,15 @@
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;
}
--- clean/linux/fs/open.c 2004-08-14 06:54:48.000000000 -0400
+++ linux/fs/open.c 2004-10-06 16:20:56.000000000 -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 +956,10 @@
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:
--- clean/linux/fs/namei.c 2004-08-14 06:55:10.000000000 -0400
+++ linux/fs/namei.c 2004-10-06 16:24:14.000000000 -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>
@@ -1221,6 +1222,8 @@
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;
@@ -1535,6 +1538,8 @@
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;
@@ -1608,6 +1613,8 @@
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;
@@ -1703,6 +1710,11 @@
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);
@@ -1775,8 +1787,13 @@
/* 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;
}
@@ -1853,6 +1870,8 @@
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;
@@ -1926,6 +1945,8 @@
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;
@@ -2089,6 +2110,8 @@
{
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;
@@ -2110,6 +2133,8 @@
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
@@ -2121,7 +2146,15 @@
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,
+ new_dentry->d_name.name);
}
+ inotify_oldname_free(old_name);
+
return error;
}
--- clean/linux/fs/inode.c 2004-08-14 06:56:23.000000000 -0400
+++ linux/fs/inode.c 2004-10-04 00:44:54.000000000 -0400
@@ -114,6 +114,9 @@
if (inode) {
struct address_space * const mapping = &inode->i_data;
+#ifdef CONFIG_INOTIFY
+ inode->inotify_data = NULL;
+#endif
inode->i_sb = sb;
inode->i_blkbits = sb->s_blocksize_bits;
inode->i_flags = 0;
--- clean/linux/fs/attr.c 2004-08-14 06:54:50.000000000 -0400
+++ linux/fs/attr.c 2004-10-14 22:23:09.000000000 -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>
@@ -103,29 +104,51 @@
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)
@@ -184,9 +207,19 @@
}
}
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;
}
--- clean/linux/fs/file_table.c 2004-08-14 06:54:48.000000000 -0400
+++ linux/fs/file_table.c 2004-10-06 16:23:00.000000000 -0400
@@ -16,6 +16,7 @@
#include <linux/eventpoll.h>
#include <linux/mount.h>
#include <linux/cdev.h>
+#include <linux/inotify.h>
/* sysctl tunables... */
struct files_stat_struct files_stat = {
@@ -168,6 +169,12 @@
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);
/*
* The function eventpoll_release() should be the first called
--- clean/linux/drivers/char/Makefile 2004-08-14 06:56:22.000000000 -0400
+++ linux/drivers/char/Makefile 2004-09-28 16:46:05.000000000 -0400
@@ -9,6 +9,8 @@
obj-y += mem.o random.o tty_io.o n_tty.o tty_ioctl.o pty.o misc.o
+
+obj-$(CONFIG_INOTIFY) += inotify.o
obj-$(CONFIG_VT) += vt_ioctl.o vc_screen.o consolemap.o \
consolemap_deftbl.o selection.o keyboard.o
obj-$(CONFIG_HW_CONSOLE) += vt.o defkeymap.o
--- clean/linux/drivers/char/Kconfig 2004-08-14 06:54:47.000000000 -0400
+++ linux/drivers/char/Kconfig 2004-09-28 16:44:34.000000000 -0400
@@ -62,6 +62,19 @@
depends on VT && !S390 && !UM
default y
+config INOTIFY
+ bool "Inotify file change notification support"
+ default y
+ ---help---
+ Say Y here to enable inotify support and the /dev/inotify character
+ device. Inotify is a file change notification system and a
+ replacement for dnotify. Inotify fixes numerous shortcomings in
+ dnotify and introduces several new features. It allows monitoring
+ of both files and directories via a single open fd. Multiple file
+ events are supported.
+
+ If unsure, say Y.
+
config SERIAL_NONSTANDARD
bool "Non-standard serial port support"
---help---
--- clean/linux/Documentation/dnotify.txt 2004-08-14 06:55:33.000000000 -0400
+++ linux/Documentation/dnotify.txt 2004-10-04 21:13:03.000000000 -0400
@@ -54,6 +54,14 @@
Also, files that are unlinked, will still cause notifications in the
last directory that they were linked to.
+Configuration
+-------------
+
+Dnotify is controlled via the CONFIG_DNOTIFY configuration option. When
+disabled, fcntl(fd, F_NOTIFY, ...) will return -EINVAL.
+
+Dnotify is deprecated in favor of inotify (CONFIG_INOTIFY).
+
Example
-------
--- clean/linux/fs/Kconfig 2004-08-14 06:55:33.000000000 -0400
+++ linux/fs/Kconfig 2004-10-04 21:13:03.000000000 -0400
@@ -438,6 +438,18 @@
depends on XFS_QUOTA || QUOTA
default y
+config DNOTIFY
+ bool "Dnotify support"
+ default y
+ help
+ Dnotify is a directory-based per-fd file change notification system
+ that uses signals to communicate events to user-space. It has
+ been replaced by inotify (see CONFIG_INOTIFY), which solves many of
+ the shortcomings of dnotify and adds new features, but some
+ applications may still rely on dnotify.
+
+ Because of this, if unsure, say Y.
+
config AUTOFS_FS
tristate "Kernel automounter support"
help
--- clean/linux/fs/Makefile 2004-08-14 06:55:33.000000000 -0400
+++ linux/fs/Makefile 2004-10-04 21:13:03.000000000 -0400
@@ -5,12 +5,11 @@
# Rewritten to use lists instead of if-statements.
#
-obj-y := open.o read_write.o file_table.o buffer.o \
- bio.o super.o block_dev.o char_dev.o stat.o exec.o pipe.o \
- namei.o fcntl.o ioctl.o readdir.o select.o fifo.o locks.o \
- dcache.o inode.o attr.o bad_inode.o file.o dnotify.o \
- filesystems.o namespace.o seq_file.o xattr.o libfs.o \
- fs-writeback.o mpage.o direct-io.o aio.o
+obj-y := open.o read_write.o file_table.o buffer.o bio.o super.o \
+ block_dev.o char_dev.o stat.o exec.o pipe.o namei.o fcntl.o \
+ ioctl.o readdir.o select.o fifo.o locks.o dcache.o inode.o \
+ attr.o bad_inode.o file.o filesystems.o namespace.o aio.o \
+ seq_file.o xattr.o libfs.o fs-writeback.o mpage.o direct-io.o \
obj-$(CONFIG_EPOLL) += eventpoll.o
obj-$(CONFIG_COMPAT) += compat.o
@@ -37,6 +36,8 @@
obj-$(CONFIG_QFMT_V2) += quota_v2.o
obj-$(CONFIG_QUOTACTL) += quota.o
+obj-$(CONFIG_DNOTIFY) += dnotify.o
+
obj-$(CONFIG_PROC_FS) += proc/
obj-y += partitions/
obj-$(CONFIG_SYSFS) += sysfs/
--- clean/linux/fs/dnotify.c 2004-08-14 06:55:10.000000000 -0400
+++ linux/fs/dnotify.c 2004-10-06 19:23:37.000000000 -0400
@@ -13,6 +13,7 @@
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*/
+
#include <linux/fs.h>
#include <linux/module.h>
#include <linux/sched.h>
@@ -21,8 +22,6 @@
#include <linux/spinlock.h>
#include <linux/slab.h>
-int dir_notify_enable = 1;
-
static kmem_cache_t *dn_cache;
static void redo_inode_mask(struct inode *inode)
@@ -72,8 +71,6 @@
dnotify_flush(filp, id);
return 0;
}
- if (!dir_notify_enable)
- return -EINVAL;
inode = filp->f_dentry->d_inode;
if (!S_ISDIR(inode->i_mode))
return -ENOTDIR;
@@ -146,6 +143,29 @@
EXPORT_SYMBOL(__inode_dir_notify);
+int setattr_mask_dnotify(unsigned int ia_valid)
+{
+ unsigned long dn_mask = 0;
+
+ 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;
+}
+EXPORT_SYMBOL(setattr_mask_dnotify);
+
/*
* This is hopelessly wrong, but unfixable without API changes. At
* least it doesn't oops the kernel...
@@ -157,9 +177,6 @@
{
struct dentry *parent;
- if (!dir_notify_enable)
- return;
-
spin_lock(&dentry->d_lock);
parent = dentry->d_parent;
if (parent->d_inode->i_dnotify_mask & event) {
--- clean/linux/include/linux/dnotify.h 2004-08-14 06:54:47.000000000 -0400
+++ linux/include/linux/dnotify.h 2004-10-06 19:23:37.000000000 -0400
@@ -1,3 +1,5 @@
+#ifndef _LINUX_DNOTIFY_H
+#define _LINUX_DNOTIFY_H
/*
* Directory notification for Linux
*
@@ -8,20 +10,60 @@
struct dnotify_struct {
struct dnotify_struct * dn_next;
- unsigned long dn_mask; /* Events to be notified
- see linux/fcntl.h */
+ unsigned long dn_mask;
int dn_fd;
struct file * dn_filp;
fl_owner_t dn_owner;
};
+#ifdef __KERNEL__
+
+#include <linux/config.h>
+
+#ifdef CONFIG_DNOTIFY
+
extern void __inode_dir_notify(struct inode *, unsigned long);
-extern void dnotify_flush(struct file *filp, fl_owner_t id);
+extern void dnotify_flush(struct file *, fl_owner_t);
extern int fcntl_dirnotify(int, struct file *, unsigned long);
-void dnotify_parent(struct dentry *dentry, unsigned long event);
+extern void dnotify_parent(struct dentry *, unsigned long);
+extern int setattr_mask_dnotify(unsigned int);
static inline void inode_dir_notify(struct inode *inode, unsigned long event)
{
- if ((inode)->i_dnotify_mask & (event))
+ if (inode->i_dnotify_mask & (event))
__inode_dir_notify(inode, event);
}
+
+#else
+
+static inline void __inode_dir_notify(struct inode *inode, unsigned long event)
+{
+}
+
+static inline void dnotify_flush(struct file *filp, fl_owner_t id)
+{
+}
+
+static inline int fcntl_dirnotify(int fd, struct file *filp, unsigned long arg)
+{
+ return -EINVAL;
+}
+
+static inline void dnotify_parent(struct dentry *dentry, unsigned long event)
+{
+}
+
+static inline void inode_dir_notify(struct inode *inode, unsigned long event)
+{
+}
+
+static inline int setattr_mask_dnotify(unsigned int ia_valid)
+{
+ return 0;
+}
+
+#endif /* CONFIG_DNOTIFY */
+
+#endif /* __KERNEL __ */
+
+#endif /* _LINUX_DNOTIFY_H */
--- clean/linux/kernel/sysctl.c 2004-08-14 06:54:49.000000000 -0400
+++ linux/kernel/sysctl.c 2004-10-04 21:13:03.000000000 -0400
@@ -868,14 +868,6 @@
.proc_handler = &proc_dointvec,
},
{
- .ctl_name = FS_DIR_NOTIFY,
- .procname = "dir-notify-enable",
- .data = &dir_notify_enable,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = &proc_dointvec,
- },
- {
.ctl_name = FS_LEASE_TIME,
.procname = "lease-break-time",
.data = &lease_break_time,
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