Re: [patch] inotify.

Robert Love
2005-06-16T18:28:53Z

On Thu, 2005-06-16 at 10:52 -0700, Zach Brown wrote:

> some quick comments, nothing earth shattering..

Thanks, zab!

> > + * struct inotify_kernel_event - An intofiy event, originating from a watch and
>
> intofiy!

Fixed.

> > +/*
> > + * inotify_dev_is_watching_inode - is this device watching this inode?
> > + *
> > + * Callers must hold dev->sem.
> > + */
> > +static inline 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;
> > +}
>
> Am I missing where this is used?

Nope. I am not using it anymore. Removed.

> > + if (likely(!atomic_read(&inode->inotify_watch_count)))
> > + return;
>
> Are there still platforms that implement atomic_read() with locks? I
> wonder if there isn't a cheaper way for inodes to find out that they're
> not involved in inotify.. maybe an inode function pointer that is only
> set to queue_event when watchers are around?

I don't know what esoteric architectures are doing, but the solution
needs to be atomic (or we need to say "we don't care about races"--but
its hard not to care about a pointer race). On x86, at least, an
atomic_read() is trivial.

I actually would not mind being racey (in a safe way) or finding a
cheaper solution, especially if we could remove
inode->inotify_watch_count altogether (and not replace it with
anything).

But the overhead here is not biting us (we just went through some
off-list benchmarking that led to the inclusion of this check, in fact).

> > + down(&inode->inotify_sem);
> > + list_for_each_entry_safe(watch, next, &inode->inotify_watches, i_list) {
> > + u32 watch_mask = watch->mask;
> > + if (watch_mask & mask) {
> > + struct inotify_device *dev = watch->dev;
> > + get_inotify_watch(watch);
> > + down(&dev->sem);
> > + inotify_dev_queue_event(dev, watch, mask, cookie, name);
>
> I wonder if its worth walking the watches as they're added and removed
> to calculate a total mask of what is being watched so that uninteresting
> events can be immediately ignored without walking the watches.

We used to do this. I found it wasn't really worth it,
performance-wise. And--I forget the details now--there was a locking
concern in caching the value. Like, where I usually grab the locks
A->B, caching the mask led me to a B->A situation. Or something.

> I also wonder about adding references to an event from each device that
> is watching the inode rather than queueing events on all the devices.
> If it only ever copies the full event to user space anyway, you'd just
> need a series of pointers on the dev that hold references to a
> refcounted event. It looks like events are only ever dequeued from the
> device as they're walked from the head of the list so it doesn't seem
> like the ability to remove an event from the middle would be missed.
>
> Too aggressive for a situation that rarely happens anyway?

_Probably_ way too aggressive for this situation, although I would not
rule it out. This is always an optimization that we can do later, if
something proves expensive, but I don't see it right now.

> It'd be nice to get some wait_event_interruptible() love to replace the
> hand-rolled _wait()s and schedule(). It could probably be folded into
> the second loop, I imagine. I suspect that the signal_pending() case
> wants to return ERESTARTSYS like w_e_i() does.

Yah, agreed.

> > + nonseekable_open(inode, file);
>
> While it doesn't return errors today, it might be nice to test anyway.

Sure. Done.

> > +/*
> > + * fsnotify_move - file old_name at old_dir was moved to new_name at new_dir
> > + */
> > +static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir,
> > + const char *old_name, const char *new_name,
> > + int isdir)
> > +{
> > + u32 cookie = inotify_get_cookie();
>
> How about deferring this atomic_inc() until it's known if the event is
> going to be queued or not so that renames that have nothing to do with
> inotify don't bounce the cache line around? If it's *only* used to
> assciate two different events with a single rename maybe it'd be better
> to roll some compound rename event.

It is hard, because we don't know if the user is watching the src and
dst until we actually get there and see that they are--we'd have to walk
every watch to find if they match and then, if so, increment the cookie
and send it out to those two watches.

> I hope this helps. I, for one, would be thrilled to see dnotify deprecated.

It helps a lot. Thank you very much for the pair of eyes, Zach.

I appreciate it.

Updated patch below!

Best,

Robert Love

inotify!

inotify is intended to correct the deficiencies of dnotify, particularly
its inability to scale and its terrible user interface:

* dnotify requires the opening of one fd per each directory
that you intend to watch. This quickly results in too many
open files and pins removable media, preventing unmount.
* 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.
* dnotify's interface to user-space is awful. Signals?

inotify provides a more usable, simple, powerful solution to file change
notification:

* inotify's interface is a device node, not SIGIO. You open a
single fd to the device node, which is select()-able.
* inotify has an event that says "the filesystem that the item
you were watching is on was unmounted."
* inotify can watch directories or files.

Inotify is currently used by Beagle (a desktop search infrastructure),
Gamin (a FAM replacement), and other projects.

See Documentation/filesystems/inotify.txt.

Signed-off-by: Robert Love <rml@novell.com>

Documentation/filesystems/inotify.txt | 123 ++++
fs/Kconfig | 13
fs/Makefile | 1
fs/attr.c | 33 -
fs/compat.c | 12
fs/file_table.c | 3
fs/inode.c | 9
fs/inotify.c | 976 ++++++++++++++++++++++++++++++++++
fs/namei.c | 30 -
fs/nfsd/vfs.c | 6
fs/open.c | 4
fs/read_write.c | 15
fs/sysfs/file.c | 7
fs/xattr.c | 5
include/linux/fs.h | 7
include/linux/fsnotify.h | 257 ++++++++
include/linux/inotify.h | 124 ++++
include/linux/sched.h | 4
kernel/user.c | 4
19 files changed, 1569 insertions(+), 64 deletions(-)

diff -urN linux-2.6.12-rc6/Documentation/filesystems/inotify.txt linux/Documentation/filesystems/inotify.txt
--- linux-2.6.12-rc6/Documentation/filesystems/inotify.txt 1969-12-31 19:00:00.000000000 -0500
+++ linux/Documentation/filesystems/inotify.txt 2005-06-13 11:28:04.000000000 -0400
@@ -0,0 +1,123 @@
+ inotify
+ a powerful yet simple file change notification system
+
+
+
+Document started 15 Mar 2005 by Robert Love <rml@novell.com>
+
+(i) User Interface
+
+Inotify is controlled by a device node, /dev/inotify. If you do not use udev,
+this device may need to be created manually. First step, open it
+
+ int dev_fd = open ("/dev/inotify", O_RDONLY);
+
+Change events are managed by "watches". A watch is an (object,mask) pair where
+the object is a file or directory and the mask is a bitmask of one or more
+inotify events that the application wishes to receive. See <linux/inotify.h>
+for valid events. A watch is referenced by a watch descriptor, or wd.
+
+Watches are added via a file descriptor.
+
+Watches on a directory will return events on any files inside of the directory.
+
+Adding a watch is simple,
+
+ /* 'wd' represents the watch on fd with mask */
+ struct inotify_request req = { fd, mask };
+ int wd = ioctl (dev_fd, INOTIFY_WATCH, &req);
+
+You can add a large number of files via something like
+
+ for each file to watch {
+ struct inotify_request req;
+ int file_fd;
+
+ file_fd = open (file, O_RDONLY);
+ if (fd < 0) {
+ perror ("open");
+ break;
+ }
+
+ req.fd = file_fd;
+ req.mask = mask;
+
+ wd = ioctl (dev_fd, INOTIFY_WATCH, &req);
+
+ close (fd);
+ }
+
+You can update an existing watch in the same manner, by passing in a new mask.
+
+An existing watch is removed via the INOTIFY_IGNORE ioctl, for example
+
+ ioctl (dev_fd, INOTIFY_IGNORE, wd);
+
+Events are provided in the form of an inotify_event structure that is read(2)
+from /dev/inotify. The filename is of dynamic length and follows the struct.
+It is of size len. The filename is padded with null bytes to ensure proper
+alignment. This padding is reflected in len.
+
+You can slurp multiple events by passing a large buffer, for example
+
+ size_t len = read (fd, buf, BUF_LEN);
+
+Will return as many events as are available and fit in BUF_LEN.
+
+/dev/inotify is also select() and poll() able.
+
+You can find the size of the current event queue via the FIONREAD ioctl.
+
+All watches are destroyed and cleaned up on close.
+
+
+(ii) Internal Kernel Implementation
+
+Each open inotify device is associated with an inotify_device structure.
+
+Each watch is associated with an inotify_watch structure. Watches are chained
+off of each associated device and each associated inode.
+
+See fs/inotify.c for the locking and lifetime rules.
+
+
+(iii) Rationale
+
+Q: What is the design decision behind not tying the watch to the
+open fd of the watched object?
+
+A: Watches are associated with an open inotify device, not an
+open file. This solves the primary problem with dnotify:
+keeping the file open pins the file and thus, worse, pins the
+mount. Dnotify is therefore infeasible for use on a desktop
+system with removable media as the media cannot be unmounted.
+
+Q: What is the design decision behind using an-fd-per-device as
+opposed to an fd-per-watch?
+
+A: An fd-per-watch quickly consumes more file descriptors than
+are allowed, more fd's than are feasible to manage, and more
+fd's than are ideally select()-able. Yes, root can bump the
+per-process fd limit and yes, users can use epoll, but requiring
+both is silly and an extraneous requirement. A watch consumes
+less memory than an open file, separating the number spaces is
+thus sensible. The current design is what user-space developers
+want: Users open the device, once, and add n watches, requiring
+but one fd and no twiddling with fd limits.
+Opening /dev/inotify two thousand times is silly. If we can
+implement user-space's preferences cleanly--and we can, the idr
+layer makes stuff like this trivial--then we should.
+
+Q: Why a device node?
+
+A: The second biggest problem with dnotify is that the user
+interface sucks ass. Signals are a terrible, terrible interface
+for file notification. Or for anything, for that matter. The
+idea solution, from all perspectives, is a file descriptor based
+one that allows basic file I/O and poll/select. Obtaining the
+fd and managing the watches could of been done either via a
+device file or a family of new system calls. We decided to
+implement a device file because adding three or four new system
+calls that mirrored open, close, and ioctl seemed silly. A
+character device makes sense from user-space and was easy to
+implement inside of the kernel.
diff -urN linux-2.6.12-rc6/fs/attr.c linux/fs/attr.c
--- linux-2.6.12-rc6/fs/attr.c 2005-06-07 15:47:52.000000000 -0400
+++ linux/fs/attr.c 2005-06-13 11:28:04.000000000 -0400
@@ -10,7 +10,7 @@
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/smp_lock.h>
-#include <linux/dnotify.h>
+#include <linux/fsnotify.h>
#include <linux/fcntl.h>
#include <linux/quotaops.h>
#include <linux/security.h>
@@ -107,31 +107,8 @@
out:
return error;
}
-
EXPORT_SYMBOL(inode_setattr);

-int setattr_mask(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;
-}
-
int notify_change(struct dentry * dentry, struct iattr * attr)
{
struct inode *inode = dentry->d_inode;
@@ -197,11 +174,9 @@
if (ia_valid & ATTR_SIZE)
up_write(&dentry->d_inode->i_alloc_sem);

- if (!error) {
- unsigned long dn_mask = setattr_mask(ia_valid);
- if (dn_mask)
- dnotify_parent(dentry, dn_mask);
- }
+ if (!error)
+ fsnotify_change(dentry, ia_valid);
+
return error;
}

diff -urN linux-2.6.12-rc6/fs/compat.c linux/fs/compat.c
--- linux-2.6.12-rc6/fs/compat.c 2005-06-07 15:47:52.000000000 -0400
+++ linux/fs/compat.c 2005-06-13 11:28:04.000000000 -0400
@@ -37,7 +37,7 @@
#include <linux/ctype.h>
#include <linux/module.h>
#include <linux/dirent.h>
-#include <linux/dnotify.h>
+#include <linux/fsnotify.h>
#include <linux/highuid.h>
#include <linux/sunrpc/svc.h>
#include <linux/nfsd/nfsd.h>
@@ -1307,9 +1307,13 @@
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;
+ if (type == READ)
+ fsnotify_access(dentry);
+ else
+ fsnotify_modify(dentry);
+ }
return ret;
}

diff -urN linux-2.6.12-rc6/fs/file_table.c linux/fs/file_table.c
--- linux-2.6.12-rc6/fs/file_table.c 2005-03-02 02:37:47.000000000 -0500
+++ linux/fs/file_table.c 2005-06-13 11:28:04.000000000 -0400
@@ -16,6 +16,7 @@
#include <linux/eventpoll.h>
#include <linux/mount.h>
#include <linux/cdev.h>
+#include <linux/fsnotify.h>

/* sysctl tunables... */
struct files_stat_struct files_stat = {
@@ -123,6 +124,8 @@
struct inode *inode = dentry->d_inode;

might_sleep();
+
+ fsnotify_close(file);
/*
* The function eventpoll_release() should be the first called
* in the file cleanup chain.
diff -urN linux-2.6.12-rc6/fs/inode.c linux/fs/inode.c
--- linux-2.6.12-rc6/fs/inode.c 2005-06-07 15:47:52.000000000 -0400
+++ linux/fs/inode.c 2005-06-13 11:28:07.000000000 -0400
@@ -21,6 +21,7 @@
#include <linux/pagemap.h>
#include <linux/cdev.h>
#include <linux/bootmem.h>
+#include <linux/inotify.h>

/*
* This is needed for the following functions:
@@ -128,6 +129,9 @@
#ifdef CONFIG_QUOTA
memset(&inode->i_dquot, 0, sizeof(inode->i_dquot));
#endif
+#ifdef CONFIG_INOTIFY
+ atomic_set(&inode->inotify_watch_count, 0);
+#endif
inode->i_pipe = NULL;
inode->i_bdev = NULL;
inode->i_cdev = NULL;
@@ -202,6 +206,10 @@
INIT_LIST_HEAD(&inode->i_data.i_mmap_nonlinear);
spin_lock_init(&inode->i_lock);
i_size_ordered_init(inode);
+#ifdef CONFIG_INOTIFY
+ INIT_LIST_HEAD(&inode->inotify_watches);
+ sema_init(&inode->inotify_sem, 1);
+#endif
}

EXPORT_SYMBOL(inode_init_once);
@@ -346,6 +354,7 @@

down(&iprune_sem);
spin_lock(&inode_lock);
+ inotify_unmount_inodes(&sb->s_inodes);
busy = invalidate_list(&sb->s_inodes, &throw_away);
spin_unlock(&inode_lock);

diff -urN linux-2.6.12-rc6/fs/inotify.c linux/fs/inotify.c
--- linux-2.6.12-rc6/fs/inotify.c 1969-12-31 19:00:00.000000000 -0500
+++ linux/fs/inotify.c 2005-06-16 14:21:42.000000000 -0400
@@ -0,0 +1,976 @@
+/*
+ * fs/inotify.c - inode-based file event notifications
+ *
+ * Authors:
+ * John McCutchan <ttb@tentacle.dhs.org>
+ * Robert Love <rml@novell.com>
+ *
+ * Copyright (C) 2005 John McCutchan
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2, or (at your option) any
+ * later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
+#include <linux/idr.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/file.h>
+#include <linux/namei.h>
+#include <linux/poll.h>
+#include <linux/device.h>
+#include <linux/miscdevice.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/writeback.h>
+#include <linux/inotify.h>
+
+#include <asm/ioctls.h>
+
+static atomic_t inotify_cookie;
+
+static kmem_cache_t *watch_cachep;
+static kmem_cache_t *event_cachep;
+
+static int max_user_devices;
+static int max_user_watches;
+static unsigned int max_queued_events;
+
+/*
+ * Lock ordering:
+ *
+ * dentry->d_lock (used to keep d_move() away from dentry->d_parent)
+ * iprune_sem (synchronize shrink_icache_memory())
+ * inode_lock (protects the super_block->s_inodes list)
+ * inode->inotify_sem (protects inode->inotify_watches and watches->i_list)
+ * inotify_dev->sem (protects inotify_device and watches->d_list)
+ */
+
+/*
+ * Lifetimes of the three main data structures--inotify_device, inode, and
+ * inotify_watch--are managed by reference count.
+ *
+ * inotify_device: Lifetime is from open until release. Additional references
+ * can bump the count via get_inotify_dev() and drop the count via
+ * put_inotify_dev().
+ *
+ * inotify_watch: Lifetime is from create_watch() to destory_watch().
+ * Additional references can bump the count via get_inotify_watch() and drop
+ * the count via put_inotify_watch().
+ *
+ * inode: Pinned so long as the inode is associated with a watch, from
+ * create_watch() to put_inotify_watch().
+ */
+
+/*
+ * struct inotify_device - represents an open instance of an inotify device
+ *
+ * This structure is protected by the semaphore 'sem'.
+ */
+struct inotify_device {
+ wait_queue_head_t wq; /* wait queue for i/o */
+ struct idr idr; /* idr mapping wd -> watch */
+ struct semaphore sem; /* protects this bad boy */
+ struct list_head events; /* list of queued events */
+ struct list_head watches; /* list of watches */
+ atomic_t count; /* reference count */
+ struct user_struct *user; /* user who opened this dev */
+ unsigned int queue_size; /* size of the queue (bytes) */
+ unsigned int event_count; /* number of pending events */
+ unsigned int max_events; /* maximum number of events */
+};
+
+/*
+ * struct inotify_kernel_event - An inotify event, originating from a watch and
+ * queued for user-space. A list of these is attached to each instance of the
+ * device. In read(), this list is walked and all events that can fit in the
+ * buffer are returned.
+ *
+ * Protected by dev->sem of the device in which we are queued.
+ */
+struct inotify_kernel_event {
+ struct inotify_event event; /* the user-space event */
+ struct list_head list; /* entry in inotify_device's list */
+ char *name; /* filename, if any */
+};
+
+/*
+ * struct inotify_watch - represents a watch request on a specific inode
+ *
+ * d_list is protected by dev->sem of the associated watch->dev.
+ * i_list and mask are protected by inode->inotify_sem of the associated inode.
+ * dev, inode, and wd are never written to once the watch is created.
+ */
+struct inotify_watch {
+ struct list_head d_list; /* entry in inotify_device's list */
+ struct list_head i_list; /* entry in inode's list */
+ atomic_t count; /* reference count */
+ struct inotify_device *dev; /* associated device */
+ struct inode *inode; /* associated inode */
+ s32 wd; /* watch descriptor */
+ u32 mask; /* event mask for this watch */
+};
+
+static ssize_t show_max_queued_events(struct class_device *class, char *buf)
+{
+ return sprintf(buf, "%d\n", max_queued_events);
+}
+
+static ssize_t store_max_queued_events(struct class_device *class,
+ const char *buf, size_t count)
+{
+ unsigned int max;
+
+ if (sscanf(buf, "%u", &max) > 0 && max > 0) {
+ max_queued_events = max;
+ return strlen(buf);
+ }
+ return -EINVAL;
+}
+
+static ssize_t show_max_user_devices(struct class_device *class, char *buf)
+{
+ return sprintf(buf, "%d\n", max_user_devices);
+}
+
+static ssize_t store_max_user_devices(struct class_device *class,
+ const char *buf, size_t count)
+{
+ int max;
+
+ if (sscanf(buf, "%d", &max) > 0 && max > 0) {
+ max_user_devices = max;
+ return strlen(buf);
+ }
+ return -EINVAL;
+}
+
+static ssize_t show_max_user_watches(struct class_device *class, char *buf)
+{
+ return sprintf(buf, "%d\n", max_user_watches);
+}
+
+static ssize_t store_max_user_watches(struct class_device *class,
+ const char *buf, size_t count)
+{
+ int max;
+
+ if (sscanf(buf, "%d", &max) > 0 && max > 0) {
+ max_user_watches = max;
+ return strlen(buf);
+ }
+ return -EINVAL;
+}
+
+static CLASS_DEVICE_ATTR(max_queued_events, S_IRUGO | S_IWUSR,
+ show_max_queued_events, store_max_queued_events);
+static CLASS_DEVICE_ATTR(max_user_devices, S_IRUGO | S_IWUSR,
+ show_max_user_devices, store_max_user_devices);
+static CLASS_DEVICE_ATTR(max_user_watches, S_IRUGO | S_IWUSR,
+ show_max_user_watches, store_max_user_watches);
+
+static inline void get_inotify_dev(struct inotify_device *dev)
+{
+ atomic_inc(&dev->count);
+}
+
+static inline void put_inotify_dev(struct inotify_device *dev)
+{
+ if (atomic_dec_and_test(&dev->count)) {
+ atomic_dec(&dev->user->inotify_devs);
+ free_uid(dev->user);
+ kfree(dev);
+ }
+}
+
+static inline void get_inotify_watch(struct inotify_watch *watch)
+{
+ atomic_inc(&watch->count);
+}
+
+/*
+ * put_inotify_watch - decrements the ref count on a given watch. cleans up
+ * the watch and its references if the count reaches zero.
+ */
+static inline void put_inotify_watch(struct inotify_watch *watch)
+{
+ if (atomic_dec_and_test(&watch->count)) {
+ put_inotify_dev(watch->dev);
+ iput(watch->inode);
+ kmem_cache_free(watch_cachep, watch);
+ }
+}
+
+/*
+ * kernel_event - create a new kernel event with the given parameters
+ *
+ * This function can sleep.
+ */
+static struct inotify_kernel_event * kernel_event(s32 wd, u32 mask, u32 cookie,
+ const char *name)
+{
+ struct inotify_kernel_event *kevent;
+
+ kevent = kmem_cache_alloc(event_cachep, GFP_KERNEL);
+ if (unlikely(!kevent))
+ return NULL;
+
+ /* we hand this out to user-space, so zero it just in case */
+ memset(&kevent->event, 0, sizeof(struct inotify_event));
+
+ kevent->event.wd = wd;
+ kevent->event.mask = mask;
+ kevent->event.cookie = cookie;
+
+ INIT_LIST_HEAD(&kevent->list);
+
+ if (name) {
+ size_t len, rem, event_size = sizeof(struct inotify_event);
+
+ /*
+ * We need to pad the filename so as to properly align an
+ * array of inotify_event structures. Because the structure is
+ * small and the common case is a small filename, we just round
+ * up to the next multiple of the structure's sizeof. This is
+ * simple and safe for all architectures.
+ */
+ len = strlen(name) + 1;
+ rem = event_size - len;
+ if (len > event_size) {
+ rem = event_size - (len % event_size);
+ if (len % event_size == 0)
+ rem = 0;
+ }
+
+ kevent->name = kmalloc(len + rem, GFP_KERNEL);
+ if (unlikely(!kevent->name)) {
+ kmem_cache_free(event_cachep, kevent);
+ return NULL;
+ }
+ memcpy(kevent->name, name, len);
+ if (rem)
+ memset(kevent->name + len, 0, rem);
+ kevent->event.len = len + rem;
+ } else {
+ kevent->event.len = 0;
+ kevent->name = NULL;
+ }
+
+ return kevent;
+}
+
+/*
+ * inotify_dev_get_event - return the next event in the given dev's queue
+ *
+ * Caller must hold dev->sem.
+ */
+static inline struct inotify_kernel_event *
+inotify_dev_get_event(struct inotify_device *dev)
+{
+ return list_entry(dev->events.next, struct inotify_kernel_event, list);
+}
+
+/*
+ * inotify_dev_queue_event - add a new event to the given device
+ *
+ * Caller must hold dev->sem. Can sleep (calls kernel_event()).
+ */
+static void inotify_dev_queue_event(struct inotify_device *dev,
+ struct inotify_watch *watch, u32 mask,
+ u32 cookie, const char *name)
+{
+ struct inotify_kernel_event *kevent, *last;
+
+ /* coalescing: drop this event if it is a dupe of the previous */
+ last = inotify_dev_get_event(dev);
+ if (last && last->event.mask == mask && last->event.wd == watch->wd &&
+ last->event.cookie == cookie) {
+ const char *lastname = last->name;
+
+ if (!name && !lastname)
+ return;
+ if (name && lastname && !strcmp(lastname, name))
+ return;
+ }
+
+ /* the queue overflowed and we already sent the Q_OVERFLOW event */
+ if (unlikely(dev->event_count > dev->max_events))
+ return;
+
+ /* if the queue overflows, we need to notify user space */
+ if (unlikely(dev->event_count == dev->max_events))
+ kevent = kernel_event(-1, IN_Q_OVERFLOW, cookie, NULL);
+ else
+ kevent = kernel_event(watch->wd, mask, cookie, name);
+
+ if (unlikely(!kevent))
+ return;
+
+ /* queue the event and wake up anyone waiting */
+ dev->event_count++;
+ dev->queue_size += sizeof(struct inotify_event) + kevent->event.len;
+ list_add_tail(&kevent->list, &dev->events);
+ wake_up_interruptible(&dev->wq);
+}
+
+/*
+ * remove_kevent - cleans up and ultimately frees the given kevent
+ *
+ * Caller must hold dev->sem.
+ */
+static void remove_kevent(struct inotify_device *dev,
+ struct inotify_kernel_event *kevent)
+{
+ list_del(&kevent->list);
+
+ dev->event_count--;
+ dev->queue_size -= sizeof(struct inotify_event) + kevent->event.len;
+
+ kfree(kevent->name);
+ kmem_cache_free(event_cachep, kevent);
+}
+
+/*
+ * inotify_dev_event_dequeue - destroy an event on the given device
+ *
+ * Caller must hold dev->sem.
+ */
+static void inotify_dev_event_dequeue(struct inotify_device *dev)
+{
+ if (!list_empty(&dev->events)) {
+ struct inotify_kernel_event *kevent;
+ kevent = inotify_dev_get_event(dev);
+ remove_kevent(dev, kevent);
+ }
+}
+
+/*
+ * inotify_dev_get_wd - returns the next WD for use by the given dev
+ *
+ * Callers must hold dev->sem. This function can sleep.
+ */
+static int inotify_dev_get_wd(struct inotify_device *dev,
+ struct inotify_watch *watch)
+{
+ int ret;
+
+ do {
+ if (unlikely(!idr_pre_get(&dev->idr, GFP_KERNEL)))
+ return -ENOSPC;
+ ret = idr_get_new(&dev->idr, watch, &watch->wd);
+ } while (ret == -EAGAIN);
+
+ return ret;
+}
+
+/*
+ * create_watch - creates a watch on the given device.
+ *
+ * Callers must hold dev->sem. Calls inotify_dev_get_wd() so may sleep.
+ * Both 'dev' and 'inode' (by way of nameidata) need to be pinned.
+ */
+static struct inotify_watch *create_watch(struct inotify_device *dev,
+ u32 mask, struct inode *inode)
+{
+ struct inotify_watch *watch;
+ int ret;
+
+ if (atomic_read(&dev->user->inotify_watches) >= max_user_watches)
+ return ERR_PTR(-ENOSPC);
+
+ watch = kmem_cache_alloc(watch_cachep, GFP_KERNEL);
+ if (unlikely(!watch))
+ return ERR_PTR(-ENOMEM);
+
+ ret = inotify_dev_get_wd(dev, watch);
+ if (unlikely(ret)) {
+ kmem_cache_free(watch_cachep, watch);
+ return ERR_PTR(ret);
+ }
+
+ watch->mask = mask;
+ atomic_set(&watch->count, 0);
+ INIT_LIST_HEAD(&watch->d_list);
+ INIT_LIST_HEAD(&watch->i_list);
+
+ /* save a reference to device and bump the count to make it official */
+ get_inotify_dev(dev);
+ watch->dev = dev;
+
+ /*
+ * Save a reference to the inode and bump the ref count to make it
+ * official. We hold a reference to nameidata, which makes this safe.
+ */
+ watch->inode = igrab(inode);
+
+ /* bump our own count, corresponding to our entry in dev->watches */
+ get_inotify_watch(watch);
+
+ atomic_inc(&dev->user->inotify_watches);
+ atomic_inc(&watch->inode->inotify_watch_count);
+
+ return watch;
+}
+
+/*
+ * inotify_find_dev - find the watch associated with the given inode and dev
+ *
+ * Callers must hold inode->inotify_sem.
+ */
+static struct inotify_watch *inode_find_dev(struct inode *inode,
+ struct inotify_device *dev)
+{
+ struct inotify_watch *watch;
+
+ list_for_each_entry(watch, &inode->inotify_watches, i_list) {
+ if (watch->dev == dev)
+ return watch;
+ }
+
+ return NULL;
+}
+
+/*
+ * remove_watch_no_event - remove_watch() without the IN_IGNORED event.
+ */
+static void remove_watch_no_event(struct inotify_watch *watch,
+ struct inotify_device *dev)
+{
+ list_del(&watch->i_list);
+ list_del(&watch->d_list);
+
+ atomic_dec(&watch->inode->inotify_watch_count);
+ atomic_dec(&dev->user->inotify_watches);
+ idr_remove(&dev->idr, watch->wd);
+ put_inotify_watch(watch);
+}
+
+/*
+ * remove_watch - Remove a watch from both the device and the inode. Sends
+ * the IN_IGNORED event to the given device signifying that the inode is no
+ * longer watched.
+ *
+ * Callers must hold both inode->inotify_sem and dev->sem. We drop a
+ * reference to the inode before returning.
+ *
+ * The inode is not iput() so as to remain atomic. If the inode needs to be
+ * iput(), the call returns one. Otherwise, it returns zero.
+ */
+static void remove_watch(struct inotify_watch *watch,struct inotify_device *dev)
+{
+ inotify_dev_queue_event(dev, watch, IN_IGNORED, 0, NULL);
+ remove_watch_no_event(watch, dev);
+}
+
+/* Kernel API */
+
+/**
+ * inotify_inode_queue_event - queue an event to all watches on this inode
+ * @inode: inode event is originating from
+ * @mask: event mask describing this event
+ * @cookie: cookie for synchronization, or zero
+ * @name: filename, if any
+ */
+void inotify_inode_queue_event(struct inode *inode, u32 mask, u32 cookie,
+ const char *name)
+{
+ struct inotify_watch *watch, *next;
+
+ if (likely(!atomic_read(&inode->inotify_watch_count)))
+ return;
+
+ down(&inode->inotify_sem);
+ list_for_each_entry_safe(watch, next, &inode->inotify_watches, i_list) {
+ u32 watch_mask = watch->mask;
+ if (watch_mask & mask) {
+ struct inotify_device *dev = watch->dev;
+ get_inotify_watch(watch);
+ down(&dev->sem);
+ inotify_dev_queue_event(dev, watch, mask, cookie, name);
+ if (watch_mask & IN_ONESHOT)
+ remove_watch_no_event(watch, dev);
+ up(&dev->sem);
+ put_inotify_watch(watch);
+ }
+ }
+ up(&inode->inotify_sem);
+}
+EXPORT_SYMBOL_GPL(inotify_inode_queue_event);
+
+/**
+ * inotify_dentry_parent_queue_event - queue an event to a dentry's parent
+ * @dentry: the dentry in question, we queue against this dentry's parent
+ * @mask: event mask describing this event
+ * @cookie: cookie for synchronization, or zero
+ * @name: filename, if any
+ */
+void inotify_dentry_parent_queue_event(struct dentry *dentry, u32 mask,
+ u32 cookie, const char *name)
+{
+ struct dentry *parent;
+ struct inode *inode;
+
+ spin_lock(&dentry->d_lock);
+ parent = dentry->d_parent;
+ inode = parent->d_inode;
+
+ if (unlikely(atomic_read(&inode->inotify_watch_count))) {
+ dget(parent);
+ spin_unlock(&dentry->d_lock);
+ inotify_inode_queue_event(inode, mask, cookie, name);
+ dput(parent);
+ } else
+ spin_unlock(&dentry->d_lock);
+}
+EXPORT_SYMBOL_GPL(inotify_dentry_parent_queue_event);
+
+/**
+ * inotify_get_cookie - return a unique cookie for use in synchronizing events.
+ */
+u32 inotify_get_cookie(void)
+{
+ return atomic_inc_return(&inotify_cookie);
+}
+EXPORT_SYMBOL_GPL(inotify_get_cookie);
+
+/**
+ * inotify_unmount_inodes - an sb is unmounting. handle any watched inodes.
+ * @list: list of inodes being unmounted (sb->s_inodes)
+ *
+ * Called with inode_lock held, protecting the unmounting super block's list
+ * of inodes, and with iprune_sem held, keeping shrink_icache_memory() at bay.
+ * We temporarily drop inode_lock, however, and CAN block.
+ */
+void inotify_unmount_inodes(struct list_head *list)
+{
+ struct inode *inode, *next_i;
+
+ list_for_each_entry_safe(inode, next_i, list, i_sb_list) {
+ struct inotify_watch *watch, *next_w;
+ struct list_head *watches;
+
+ /*
+ * We cannot __iget() an inode in state I_CLEAR, which is fine
+ * as by that point the inode cannot have any watches.
+ */
+ if (inode->i_state & I_CLEAR)
+ continue;
+
+ /* In case the remove_watch() drops a reference */
+ __iget(inode);
+
+ /*
+ * We can safely drop inode_lock here because the per-sb list
+ * of inodes must not change during unmount and iprune_sem
+ * keeps shrink_icache_memory() away.
+ */
+ spin_unlock(&inode_lock);
+
+ /* for each watch, send IN_UNMOUNT and then remove it */
+ down(&inode->inotify_sem);
+ watches = &inode->inotify_watches;
+ list_for_each_entry_safe(watch, next_w, watches, i_list) {
+ struct inotify_device *dev = watch->dev;
+ down(&dev->sem);
+ inotify_dev_queue_event(dev, watch, IN_UNMOUNT,0,NULL);
+ remove_watch(watch, dev);
+ up(&dev->sem);
+ }
+ up(&inode->inotify_sem);
+ iput(inode);
+
+ spin_lock(&inode_lock);
+ }
+}
+EXPORT_SYMBOL_GPL(inotify_unmount_inodes);
+
+/**
+ * inotify_inode_is_dead - an inode has been deleted, cleanup any watches
+ * @inode: inode that is about to be removed
+ */
+void inotify_inode_is_dead(struct inode *inode)
+{
+ struct inotify_watch *watch, *next;
+
+ down(&inode->inotify_sem);
+ list_for_each_entry_safe(watch, next, &inode->inotify_watches, i_list) {
+ struct inotify_device *dev = watch->dev;
+ down(&dev->sem);
+ remove_watch(watch, dev);
+ up(&dev->sem);
+ }
+ up(&inode->inotify_sem);
+}
+EXPORT_SYMBOL_GPL(inotify_inode_is_dead);
+
+/* Device Interface */
+
+static unsigned int inotify_poll(struct file *file, poll_table *wait)
+{
+ struct inotify_device *dev = file->private_data;
+ int ret = 0;
+
+ poll_wait(file, &dev->wq, wait);
+ down(&dev->sem);
+ if (!list_empty(&dev->events))
+ ret = POLLIN | POLLRDNORM;
+ up(&dev->sem);
+
+ return ret;
+}
+
+static ssize_t inotify_read(struct file *file, char __user *buf,
+ size_t count, loff_t *pos)
+{
+ size_t event_size = sizeof (struct inotify_event);
+ struct inotify_device *dev;
+ char __user *start;
+ int ret;
+ DEFINE_WAIT(wait);
+
+ start = buf;
+ dev = file->private_data;
+
+ while (1) {
+ int events;
+
+ prepare_to_wait(&dev->wq, &wait, TASK_INTERRUPTIBLE);
+
+ down(&dev->sem);
+ events = !list_empty(&dev->events);
+ up(&dev->sem);
+ if (events) {
+ ret = 0;
+ break;
+ }
+
+ if (file->f_flags & O_NONBLOCK) {
+ ret = -EAGAIN;
+ break;
+ }
+
+ if (signal_pending(current)) {
+ ret = -EINTR;
+ break;
+ }
+
+ schedule();
+ }
+
+ finish_wait(&dev->wq, &wait);
+ if (ret)
+ return ret;
+
+ down(&dev->sem);
+ while (1) {
+ struct inotify_kernel_event *kevent;
+
+ ret = buf - start;
+ if (list_empty(&dev->events))
+ break;
+
+ kevent = inotify_dev_get_event(dev);
+ if (event_size + kevent->event.len > count)
+ break;
+
+ if (copy_to_user(buf, &kevent->event, event_size)) {
+ ret = -EFAULT;
+ break;
+ }
+ buf += event_size;
+ count -= event_size;
+
+ if (kevent->name) {
+ if (copy_to_user(buf, kevent->name, kevent->event.len)){
+ ret = -EFAULT;
+ break;
+ }
+ buf += kevent->event.len;
+ count -= kevent->event.len;
+ }
+
+ remove_kevent(dev, kevent);
+ }
+ up(&dev->sem);
+
+ return ret;
+}
+
+static int inotify_open(struct inode *inode, struct file *file)
+{
+ struct inotify_device *dev;
+ struct user_struct *user;
+ int ret;
+
+ user = get_uid(current->user);
+
+ if (unlikely(atomic_read(&user->inotify_devs) >= max_user_devices)) {
+ ret = -EMFILE;
+ goto out_err;
+ }
+
+ dev = kmalloc(sizeof(struct inotify_device), GFP_KERNEL);
+ if (unlikely(!dev)) {
+ ret = -ENOMEM;
+ goto out_err;
+ }
+
+ idr_init(&dev->idr);
+ INIT_LIST_HEAD(&dev->events);
+ INIT_LIST_HEAD(&dev->watches);
+ init_waitqueue_head(&dev->wq);
+ sema_init(&dev->sem, 1);
+ dev->event_count = 0;
+ dev->queue_size = 0;
+ dev->max_events = max_queued_events;
+ dev->user = user;
+ atomic_set(&dev->count, 0);
+
+ get_inotify_dev(dev);
+ atomic_inc(&user->inotify_devs);
+
+ file->private_data = dev;
+
+ ret = nonseekable_open(inode, file);
+ if (ret)
+ goto out_err;
+
+ return 0;
+out_err:
+ free_uid(user);
+ return ret;
+}
+
+static int inotify_release(struct inode *ignored, struct file *file)
+{
+ struct inotify_device *dev = file->private_data;
+
+ /*
+ * Destroy all of the watches on this device. Unfortunately, not very
+ * pretty. We cannot do a simple iteration over the list, because we
+ * do not know the inode until we iterate to the watch. But we need to
+ * hold inode->inotify_sem before dev->sem. The following works.
+ */
+ while (1) {
+ struct inotify_watch *watch;
+ struct list_head *watches;
+ struct inode *inode;
+
+ down(&dev->sem);
+ watches = &dev->watches;
+ if (list_empty(watches)) {
+ up(&dev->sem);
+ break;
+ }
+ watch = list_entry(watches->next, struct inotify_watch, d_list);
+ get_inotify_watch(watch);
+ up(&dev->sem);
+
+ inode = watch->inode;
+ down(&inode->inotify_sem);
+ down(&dev->sem);
+ remove_watch_no_event(watch, dev);
+ up(&dev->sem);
+ up(&inode->inotify_sem);
+ put_inotify_watch(watch);
+ }
+
+ /* destroy all of the events on this device */
+ down(&dev->sem);
+ while (!list_empty(&dev->events))
+ inotify_dev_event_dequeue(dev);
+ up(&dev->sem);
+
+ /* free this device: the put matching the get in inotify_open() */
+ put_inotify_dev(dev);
+
+ return 0;
+}
+
+static int inotify_add_watch(struct inotify_device *dev, int fd, u32 mask)
+{
+ struct inotify_watch *watch, *old;
+ struct inode *inode;
+ struct file *filp;
+ int ret;
+
+ filp = fget(fd);
+ if (!filp)
+ return -EBADF;
+ inode = filp->f_dentry->d_inode;
+
+ down(&inode->inotify_sem);
+ down(&dev->sem);
+
+ /* don't let user-space set invalid bits: we don't want flags set */
+ mask &= IN_ALL_EVENTS;
+ if (!mask) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ /*
+ * Handle the case of re-adding a watch on an (inode,dev) pair that we
+ * are already watching. We just update the mask and return its wd.
+ */
+ old = inode_find_dev(inode, dev);
+ if (unlikely(old)) {
+ old->mask = mask;
+ ret = old->wd;
+ goto out;
+ }
+
+ watch = create_watch(dev, mask, inode);
+ if (unlikely(IS_ERR(watch))) {
+ ret = PTR_ERR(watch);
+ goto out;
+ }
+
+ /* Add the watch to the device's and the inode's list */
+ list_add(&watch->d_list, &dev->watches);
+ list_add(&watch->i_list, &inode->inotify_watches);
+ ret = watch->wd;
+
+out:
+ up(&dev->sem);
+ up(&inode->inotify_sem);
+ fput(filp);
+
+ return ret;
+}
+
+/*
+ * inotify_ignore - handle the INOTIFY_IGNORE ioctl, asking that a given wd be
+ * removed from the device.
+ *
+ * Can sleep.
+ */
+static int inotify_ignore(struct inotify_device *dev, s32 wd)
+{
+ struct inotify_watch *watch;
+ struct inode *inode;
+
+ down(&dev->sem);
+ watch = idr_find(&dev->idr, wd);
+ if (unlikely(!watch)) {
+ up(&dev->sem);
+ return -EINVAL;
+ }
+ get_inotify_watch(watch);
+ inode = watch->inode;
+ up(&dev->sem);
+
+ down(&inode->inotify_sem);
+ down(&dev->sem);
+
+ /* make sure that we did not race */
+ watch = idr_find(&dev->idr, wd);
+ if (likely(watch))
+ remove_watch(watch, dev);
+
+ up(&dev->sem);
+ up(&inode->inotify_sem);
+ put_inotify_watch(watch);
+
+ return 0;
+}
+
+static long inotify_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ struct inotify_device *dev;
+ struct inotify_watch_request request;
+ void __user *p;
+ int ret = -ENOTTY;
+ s32 wd;
+
+ dev = file->private_data;
+ p = (void __user *) arg;
+
+ switch (cmd) {
+ case INOTIFY_WATCH:
+ if (unlikely(copy_from_user(&request, p, sizeof (request)))) {
+ ret = -EFAULT;
+ break;
+ }
+ ret = inotify_add_watch(dev, request.fd, request.mask);
+ break;
+ case INOTIFY_IGNORE:
+ if (unlikely(get_user(wd, (int __user *) p))) {
+ ret = -EFAULT;
+ break;
+ }
+ ret = inotify_ignore(dev, wd);
+ break;
+ case FIONREAD:
+ ret = put_user(dev->queue_size, (int __user *) p);
+ break;
+ }
+
+ return ret;
+}
+
+static struct file_operations inotify_fops = {
+ .owner = THIS_MODULE,
+ .poll = inotify_poll,
+ .read = inotify_read,
+ .open = inotify_open,
+ .release = inotify_release,
+ .unlocked_ioctl = inotify_ioctl,
+ .compat_ioctl = inotify_ioctl,
+};
+
+static struct miscdevice inotify_device = {
+ .minor = MISC_DYNAMIC_MINOR,
+ .name = "inotify",
+ .fops = &inotify_fops,
+};
+
+/*
+ * inotify_init - Our initialization function. Note that we cannnot return
+ * error because we have compiled-in VFS hooks. So an (unlikely) failure here
+ * must result in panic().
+ */
+static int __init inotify_init(void)
+{
+ struct class_device *class;
+ int ret;
+
+ ret = misc_register(&inotify_device);
+ if (unlikely(ret))
+ panic("inotify: misc_register returned %d\n", ret);
+
+ max_queued_events = 8192;
+ max_user_devices = 128;
+ max_user_watches = 8192;
+
+ class = inotify_device.class;
+ class_device_create_file(class, &class_device_attr_max_queued_events);
+ class_device_create_file(class, &class_device_attr_max_user_devices);
+ class_device_create_file(class, &class_device_attr_max_user_watches);
+
+ atomic_set(&inotify_cookie, 0);
+
+ watch_cachep = kmem_cache_create("inotify_watch_cache",
+ sizeof(struct inotify_watch),
+ 0, SLAB_PANIC, NULL, NULL);
+ event_cachep = kmem_cache_create("inotify_event_cache",
+ sizeof(struct inotify_kernel_event),
+ 0, SLAB_PANIC, NULL, NULL);
+
+ printk(KERN_INFO "inotify device minor=%d\n", inotify_device.minor);
+
+ return 0;
+}
+
+module_init(inotify_init);
diff -urN linux-2.6.12-rc6/fs/Kconfig linux/fs/Kconfig
--- linux-2.6.12-rc6/fs/Kconfig 2005-06-07 15:47:52.000000000 -0400
+++ linux/fs/Kconfig 2005-06-13 11:28:04.000000000 -0400
@@ -339,6 +339,19 @@
If you don't know whether you need it, then you don't need it:
answer N.

+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 QUOTA
bool "Quota support"
help
diff -urN linux-2.6.12-rc6/fs/Makefile linux/fs/Makefile
--- linux-2.6.12-rc6/fs/Makefile 2005-03-02 02:38:10.000000000 -0500
+++ linux/fs/Makefile 2005-06-13 11:28:04.000000000 -0400
@@ -11,6 +11,7 @@
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-$(CONFIG_INOTIFY) += inotify.o
obj-$(CONFIG_EPOLL) += eventpoll.o
obj-$(CONFIG_COMPAT) += compat.o

diff -urN linux-2.6.12-rc6/fs/namei.c linux/fs/namei.c
--- linux-2.6.12-rc6/fs/namei.c 2005-06-07 15:47:52.000000000 -0400
+++ linux/fs/namei.c 2005-06-13 11:28:04.000000000 -0400
@@ -21,7 +21,7 @@
#include <linux/namei.h>
#include <linux/quotaops.h>
#include <linux/pagemap.h>
-#include <linux/dnotify.h>
+#include <linux/fsnotify.h>
#include <linux/smp_lock.h>
#include <linux/personality.h>
#include <linux/security.h>
@@ -1296,7 +1296,7 @@
DQUOT_INIT(dir);
error = dir->i_op->create(dir, dentry, mode, nd);
if (!error) {
- inode_dir_notify(dir, DN_CREATE);
+ fsnotify_create(dir, dentry->d_name.name);
security_inode_post_create(dir, dentry, mode);
}
return error;
@@ -1602,7 +1602,7 @@
DQUOT_INIT(dir);
error = dir->i_op->mknod(dir, dentry, mode, dev);
if (!error) {
- inode_dir_notify(dir, DN_CREATE);
+ fsnotify_create(dir, dentry->d_name.name);
security_inode_post_mknod(dir, dentry, mode, dev);
}
return error;
@@ -1675,7 +1675,7 @@
DQUOT_INIT(dir);
error = dir->i_op->mkdir(dir, dentry, mode);
if (!error) {
- inode_dir_notify(dir, DN_CREATE);
+ fsnotify_mkdir(dir, dentry->d_name.name);
security_inode_post_mkdir(dir,dentry, mode);
}
return error;
@@ -1766,7 +1766,7 @@
}
up(&dentry->d_inode->i_sem);
if (!error) {
- inode_dir_notify(dir, DN_DELETE);
+ fsnotify_rmdir(dentry, dentry->d_inode, dir);
d_delete(dentry);
}
dput(dentry);
@@ -1839,9 +1839,10 @@

/* We don't d_delete() NFS sillyrenamed files--they still exist. */
if (!error && !(dentry->d_flags & DCACHE_NFSFS_RENAMED)) {
+ fsnotify_unlink(dentry, dir);
d_delete(dentry);
- inode_dir_notify(dir, DN_DELETE);
}
+
return error;
}

@@ -1915,7 +1916,7 @@
DQUOT_INIT(dir);
error = dir->i_op->symlink(dir, dentry, oldname);
if (!error) {
- inode_dir_notify(dir, DN_CREATE);
+ fsnotify_create(dir, dentry->d_name.name);
security_inode_post_symlink(dir, dentry, oldname);
}
return error;
@@ -1988,7 +1989,7 @@
error = dir->i_op->link(old_dentry, dir, new_dentry);
up(&old_dentry->d_inode->i_sem);
if (!error) {
- inode_dir_notify(dir, DN_CREATE);
+ fsnotify_create(dir, new_dentry->d_name.name);
security_inode_post_link(old_dentry, dir, new_dentry);
}
return error;
@@ -2152,6 +2153,7 @@
{
int error;
int is_dir = S_ISDIR(old_dentry->d_inode->i_mode);
+ const char *old_name;

if (old_dentry->d_inode == new_dentry->d_inode)
return 0;
@@ -2173,18 +2175,18 @@
DQUOT_INIT(old_dir);
DQUOT_INIT(new_dir);

+ old_name = fsnotify_oldname_init(old_dentry->d_name.name);
+
if (is_dir)
error = vfs_rename_dir(old_dir,old_dentry,new_dir,new_dentry);
else
error = vfs_rename_other(old_dir,old_dentry,new_dir,new_dentry);
if (!error) {
- if (old_dir == new_dir)
- inode_dir_notify(old_dir, DN_RENAME);
- else {
- inode_dir_notify(old_dir, DN_DELETE);
- inode_dir_notify(new_dir, DN_CREATE);
- }
+ const char *new_name = old_dentry->d_name.name;
+ fsnotify_move(old_dir, new_dir, old_name, new_name, is_dir);
}
+ fsnotify_oldname_free(old_name);
+
return error;
}

diff -urN linux-2.6.12-rc6/fs/nfsd/vfs.c linux/fs/nfsd/vfs.c
--- linux-2.6.12-rc6/fs/nfsd/vfs.c 2005-06-07 15:47:52.000000000 -0400
+++ linux/fs/nfsd/vfs.c 2005-06-13 11:28:04.000000000 -0400
@@ -45,7 +45,7 @@
#endif /* CONFIG_NFSD_V3 */
#include <linux/nfsd/nfsfh.h>
#include <linux/quotaops.h>
-#include <linux/dnotify.h>
+#include <linux/fsnotify.h>
#ifdef CONFIG_NFSD_V4
#include <linux/posix_acl.h>
#include <linux/posix_acl_xattr.h>
@@ -861,7 +861,7 @@
nfsdstats.io_read += err;
*count = err;
err = 0;
- dnotify_parent(file->f_dentry, DN_ACCESS);
+ fsnotify_access(file->f_dentry);
} else
err = nfserrno(err);
out:
@@ -917,7 +917,7 @@
set_fs(oldfs);
if (err >= 0) {
nfsdstats.io_write += cnt;
- dnotify_parent(file->f_dentry, DN_MODIFY);
+ fsnotify_modify(file->f_dentry);
}

/* clear setuid/setgid flag after write */
diff -urN linux-2.6.12-rc6/fs/open.c linux/fs/open.c
--- linux-2.6.12-rc6/fs/open.c 2005-03-02 02:37:47.000000000 -0500
+++ linux/fs/open.c 2005-06-13 11:28:04.000000000 -0400
@@ -10,7 +10,7 @@
#include <linux/file.h>
#include <linux/smp_lock.h>
#include <linux/quotaops.h>
-#include <linux/dnotify.h>
+#include <linux/fsnotify.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/tty.h>
@@ -944,9 +944,11 @@
fd = get_unused_fd();
if (fd >= 0) {
struct file *f = filp_open(tmp, flags, mode);
+
error = PTR_ERR(f);
if (IS_ERR(f))
goto out_error;
+ fsnotify_open(f->f_dentry);
fd_install(fd, f);
}
out:
diff -urN linux-2.6.12-rc6/fs/read_write.c linux/fs/read_write.c
--- linux-2.6.12-rc6/fs/read_write.c 2005-06-07 15:47:52.000000000 -0400
+++ linux/fs/read_write.c 2005-06-13 11:28:04.000000000 -0400
@@ -10,7 +10,7 @@
#include <linux/file.h>
#include <linux/uio.h>
#include <linux/smp_lock.h>
-#include <linux/dnotify.h>
+#include <linux/fsnotify.h>
#include <linux/security.h>
#include <linux/module.h>
#include <linux/syscalls.h>
@@ -239,7 +239,7 @@
else
ret = do_sync_read(file, buf, count, pos);
if (ret > 0) {
- dnotify_parent(file->f_dentry, DN_ACCESS);
+ fsnotify_access(file->f_dentry);
current->rchar += ret;
}
current->syscr++;
@@ -287,7 +287,7 @@
else
ret = do_sync_write(file, buf, count, pos);
if (ret > 0) {
- dnotify_parent(file->f_dentry, DN_MODIFY);
+ fsnotify_modify(file->f_dentry);
current->wchar += ret;
}
current->syscw++;
@@ -523,9 +523,12 @@
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) {
+ if (type == READ)
+ fsnotify_access(file->f_dentry);
+ else
+ fsnotify_modify(file->f_dentry);
+ }
return ret;
Efault:
ret = -EFAULT;
diff -urN linux-2.6.12-rc6/fs/sysfs/file.c linux/fs/sysfs/file.c
--- linux-2.6.12-rc6/fs/sysfs/file.c 2005-06-07 15:47:52.000000000 -0400
+++ linux/fs/sysfs/file.c 2005-06-13 11:28:04.000000000 -0400
@@ -3,7 +3,7 @@
*/

#include <linux/module.h>
-#include <linux/dnotify.h>
+#include <linux/fsnotify.h>
#include <linux/kobject.h>
#include <asm/uaccess.h>
#include <asm/semaphore.h>
@@ -389,9 +389,6 @@
* sysfs_update_file - update the modified timestamp on an object attribute.
* @kobj: object we're acting for.
* @attr: attribute descriptor.
- *
- * Also call dnotify for the dentry, which lots of userspace programs
- * use.
*/
int sysfs_update_file(struct kobject * kobj, const struct attribute * attr)
{
@@ -406,7 +403,7 @@
if (victim->d_inode &&
(victim->d_parent->d_inode == dir->d_inode)) {
victim->d_inode->i_mtime = CURRENT_TIME;
- dnotify_parent(victim, DN_MODIFY);
+ fsnotify_modify(victim);

/**
* Drop reference from initial sysfs_get_dentry().
diff -urN linux-2.6.12-rc6/fs/xattr.c linux/fs/xattr.c
--- linux-2.6.12-rc6/fs/xattr.c 2005-03-02 02:38:07.000000000 -0500
+++ linux/fs/xattr.c 2005-06-13 11:28:04.000000000 -0400
@@ -16,6 +16,7 @@
#include <linux/security.h>
#include <linux/syscalls.h>
#include <linux/module.h>
+#include <linux/fsnotify.h>
#include <asm/uaccess.h>

/*
@@ -57,8 +58,10 @@
if (error)
goto out;
error = d->d_inode->i_op->setxattr(d, kname, kvalue, size, flags);
- if (!error)
+ if (!error) {
+ fsnotify_xattr(d);
security_inode_post_setxattr(d, kname, kvalue, size, flags);
+ }
out:
up(&d->d_inode->i_sem);
}
diff -urN linux-2.6.12-rc6/include/linux/fs.h linux/include/linux/fs.h
--- linux-2.6.12-rc6/include/linux/fs.h 2005-06-07 15:47:53.000000000 -0400
+++ linux/include/linux/fs.h 2005-06-13 11:28:07.000000000 -0400
@@ -471,6 +471,12 @@
struct dnotify_struct *i_dnotify; /* for directory notifications */
#endif

+#ifdef CONFIG_INOTIFY
+ atomic_t inotify_watch_count; /* number of watches */
+ struct list_head inotify_watches; /* watches on this inode */
+ struct semaphore inotify_sem; /* protects the watches list */
+#endif
+
unsigned long i_state;
unsigned long dirtied_when; /* jiffies of first dirtying */

@@ -1369,7 +1375,6 @@
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 int notify_change(struct dentry *, struct iattr *);
extern int permission(struct inode *, int, struct nameidata *);
extern int generic_permission(struct inode *, int,
diff -urN linux-2.6.12-rc6/include/linux/fsnotify.h linux/include/linux/fsnotify.h
--- linux-2.6.12-rc6/include/linux/fsnotify.h 1969-12-31 19:00:00.000000000 -0500
+++ linux/include/linux/fsnotify.h 2005-06-13 11:28:04.000000000 -0400
@@ -0,0 +1,257 @@
+#ifndef _LINUX_FS_NOTIFY_H
+#define _LINUX_FS_NOTIFY_H
+
+/*
+ * include/linux/fsnotify.h - generic hooks for filesystem notification, to
+ * reduce in-source duplication from both dnotify and inotify.
+ *
+ * We don't compile any of this away in some complicated menagerie of ifdefs.
+ * Instead, we rely on the code inside to optimize away as needed.
+ *
+ * (C) Copyright 2005 Robert Love
+ */
+
+#ifdef __KERNEL__
+
+#include <linux/dnotify.h>
+#include <linux/inotify.h>
+
+/*
+ * fsnotify_move - file old_name at old_dir was moved to new_name at new_dir
+ */
+static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir,
+ const char *old_name, const char *new_name,
+ int isdir)
+{
+ u32 cookie = inotify_get_cookie();
+
+ if (old_dir == new_dir)
+ inode_dir_notify(old_dir, DN_RENAME);
+ else {
+ inode_dir_notify(old_dir, DN_DELETE);
+ inode_dir_notify(new_dir, DN_CREATE);
+ }
+
+ if (isdir)
+ isdir = IN_ISDIR;
+ inotify_inode_queue_event(old_dir, IN_MOVED_FROM|isdir,cookie,old_name);
+ inotify_inode_queue_event(new_dir, IN_MOVED_TO|isdir, cookie, new_name);
+}
+
+/*
+ * fsnotify_unlink - file was unlinked
+ */
+static inline void fsnotify_unlink(struct dentry *dentry, struct inode *dir)
+{
+ struct inode *inode = dentry->d_inode;
+
+ inode_dir_notify(dir, DN_DELETE);
+ inotify_inode_queue_event(dir, IN_DELETE, 0, dentry->d_name.name);
+ inotify_inode_queue_event(inode, IN_DELETE_SELF, 0, NULL);
+
+ inotify_inode_is_dead(inode);
+}
+
+/*
+ * fsnotify_rmdir - directory was removed
+ */
+static inline void fsnotify_rmdir(struct dentry *dentry, struct inode *inode,
+ struct inode *dir)
+{
+ inode_dir_notify(dir, DN_DELETE);
+ inotify_inode_queue_event(dir,IN_DELETE|IN_ISDIR,0,dentry->d_name.name);
+ inotify_inode_queue_event(inode, IN_DELETE_SELF | IN_ISDIR, 0, NULL);
+ inotify_inode_is_dead(inode);
+}
+
+/*
+ * fsnotify_create - 'name' was linked in
+ */
+static inline void fsnotify_create(struct inode *inode, const char *name)
+{
+ inode_dir_notify(inode, DN_CREATE);
+ inotify_inode_queue_event(inode, IN_CREATE, 0, name);
+}
+
+/*
+ * fsnotify_mkdir - directory 'name' was created
+ */
+static inline void fsnotify_mkdir(struct inode *inode, const char *name)
+{
+ inode_dir_notify(inode, DN_CREATE);
+ inotify_inode_queue_event(inode, IN_CREATE | IN_ISDIR, 0, name);
+}
+
+/*
+ * fsnotify_access - file was read
+ */
+static inline void fsnotify_access(struct dentry *dentry)
+{
+ struct inode *inode = dentry->d_inode;
+ u32 mask = IN_ACCESS;
+
+ if (S_ISDIR(inode->i_mode))
+ mask |= IN_ISDIR;
+
+ dnotify_parent(dentry, DN_ACCESS);
+ inotify_dentry_parent_queue_event(dentry, mask, 0, dentry->d_name.name);
+ inotify_inode_queue_event(inode, mask, 0, NULL);
+}
+
+/*
+ * fsnotify_modify - file was modified
+ */
+static inline void fsnotify_modify(struct dentry *dentry)
+{
+ struct inode *inode = dentry->d_inode;
+ u32 mask = IN_MODIFY;
+
+ if (S_ISDIR(inode->i_mode))
+ mask |= IN_ISDIR;
+
+ dnotify_parent(dentry, DN_MODIFY);
+ inotify_dentry_parent_queue_event(dentry, mask, 0, dentry->d_name.name);
+ inotify_inode_queue_event(inode, mask, 0, NULL);
+}
+
+/*
+ * fsnotify_open - file was opened
+ */
+static inline void fsnotify_open(struct dentry *dentry)
+{
+ struct inode *inode = dentry->d_inode;
+ u32 mask = IN_OPEN;
+
+ if (S_ISDIR(inode->i_mode))
+ mask |= IN_ISDIR;
+
+ inotify_inode_queue_event(inode, mask, 0, NULL);
+ inotify_dentry_parent_queue_event(dentry, mask, 0, dentry->d_name.name);
+}
+
+/*
+ * fsnotify_close - file was closed
+ */
+static inline void fsnotify_close(struct file *file)
+{
+ struct dentry *dentry = file->f_dentry;
+ struct inode *inode = dentry->d_inode;
+ const char *name = dentry->d_name.name;
+ mode_t mode = file->f_mode;
+ u32 mask = (mode & FMODE_WRITE) ? IN_CLOSE_WRITE : IN_CLOSE_NOWRITE;
+
+ if (S_ISDIR(inode->i_mode))
+ mask |= IN_ISDIR;
+
+ inotify_dentry_parent_queue_event(dentry, mask, 0, name);
+ inotify_inode_queue_event(inode, mask, 0, NULL);
+}
+
+/*
+ * fsnotify_xattr - extended attributes were changed
+ */
+static inline void fsnotify_xattr(struct dentry *dentry)
+{
+ struct inode *inode = dentry->d_inode;
+ u32 mask = IN_ATTRIB;
+
+ if (S_ISDIR(inode->i_mode))
+ mask |= IN_ISDIR;
+
+ inotify_dentry_parent_queue_event(dentry, mask, 0, dentry->d_name.name);
+ inotify_inode_queue_event(inode, mask, 0, NULL);
+}
+
+/*
+ * fsnotify_change - notify_change event. file was modified and/or metadata
+ * was changed.
+ */
+static inline void fsnotify_change(struct dentry *dentry, unsigned int ia_valid)
+{
+ struct inode *inode = dentry->d_inode;
+ int dn_mask = 0;
+ u32 in_mask = 0;
+
+ if (ia_valid & ATTR_UID) {
+ in_mask |= IN_ATTRIB;
+ dn_mask |= DN_ATTRIB;
+ }
+ if (ia_valid & ATTR_GID) {
+ in_mask |= IN_ATTRIB;
+ dn_mask |= DN_ATTRIB;
+ }
+ if (ia_valid & ATTR_SIZE) {
+ in_mask |= IN_MODIFY;
+ dn_mask |= DN_MODIFY;
+ }
+ /* both times implies a utime(s) call */
+ if ((ia_valid & (ATTR_ATIME | ATTR_MTIME)) == (ATTR_ATIME | ATTR_MTIME))
+ {
+ in_mask |= IN_ATTRIB;
+ dn_mask |= DN_ATTRIB;
+ } else if (ia_valid & ATTR_ATIME) {
+ in_mask |= IN_ACCESS;
+ dn_mask |= DN_ACCESS;
+ } else if (ia_valid & ATTR_MTIME) {
+ in_mask |= IN_MODIFY;
+ dn_mask |= DN_MODIFY;
+ }
+ if (ia_valid & ATTR_MODE) {
+ in_mask |= IN_ATTRIB;
+ dn_mask |= DN_ATTRIB;
+ }
+
+ if (dn_mask)
+ dnotify_parent(dentry, dn_mask);
+ if (in_mask) {
+ if (S_ISDIR(inode->i_mode))
+ in_mask |= IN_ISDIR;
+ inotify_inode_queue_event(inode, in_mask, 0, NULL);
+ inotify_dentry_parent_queue_event(dentry, in_mask, 0,
+ dentry->d_name.name);
+ }
+}
+
+#ifdef CONFIG_INOTIFY /* inotify helpers */
+
+/*
+ * fsnotify_oldname_init - save off the old filename before we change it
+ *
+ * XXX: This could be kstrdup if only we could add that to lib/string.c
+ */
+static inline const char *fsnotify_oldname_init(const char *name)
+{
+ size_t len;
+ char *buf;
+
+ len = strlen(name) + 1;
+ buf = kmalloc(len, GFP_KERNEL);
+ if (likely(buf))
+ memcpy(buf, name, len);
+ return buf;
+}
+
+/*
+ * fsnotify_oldname_free - free the name we got from fsnotify_oldname_init
+ */
+static inline void fsnotify_oldname_free(const char *old_name)
+{
+ kfree(old_name);
+}
+
+#else /* CONFIG_INOTIFY */
+
+static inline const char *fsnotify_oldname_init(const char *name)
+{
+ return NULL;
+}
+
+static inline void fsnotify_oldname_free(const char *old_name)
+{
+}
+
+#endif /* ! CONFIG_INOTIFY */
+
+#endif /* __KERNEL__ */
+
+#endif /* _LINUX_FS_NOTIFY_H */
diff -urN linux-2.6.12-rc6/include/linux/inotify.h linux/include/linux/inotify.h
--- linux-2.6.12-rc6/include/linux/inotify.h 1969-12-31 19:00:00.000000000 -0500
+++ linux/include/linux/inotify.h 2005-06-13 11:28:04.000000000 -0400
@@ -0,0 +1,124 @@
+/*
+ * Inode based directory notification for Linux
+ *
+ * Copyright (C) 2005 John McCutchan
+ */
+
+#ifndef _LINUX_INOTIFY_H
+#define _LINUX_INOTIFY_H
+
+#include <linux/types.h>
+
+/*
+ * 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, ..., relative to the wd.
+ */
+struct inotify_event {
+ __s32 wd; /* watch descriptor */
+ __u32 mask; /* watch mask */
+ __u32 cookie; /* cookie to synchronize two events */
+ __u32 len; /* length (including nulls) of name */
+ char name[0]; /* stub for possible name */
+};
+
+/*
+ * struct inotify_watch_request - represents a watch request
+ *
+ * Pass to the inotify device via the INOTIFY_WATCH ioctl
+ */
+struct inotify_watch_request {
+ int fd; /* fd of filename to watch */
+ __u32 mask; /* event mask */
+};
+
+/* the following are legal, implemented events that user-space can watch for */
+#define IN_ACCESS 0x00000001 /* File was accessed */
+#define IN_MODIFY 0x00000002 /* File was modified */
+#define IN_ATTRIB 0x00000004 /* Metadata changed */
+#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_CREATE 0x00000100 /* Subfile was created */
+#define IN_DELETE 0x00000200 /* Subfile was deleted */
+#define IN_DELETE_SELF 0x00000400 /* Self was deleted */
+
+/* the following are legal events. they are sent as needed to any watch */
+#define IN_UNMOUNT 0x00002000 /* Backing fs was unmounted */
+#define IN_Q_OVERFLOW 0x00004000 /* Event queued overflowed */
+#define IN_IGNORED 0x00008000 /* File was ignored */
+
+/* helper events */
+#define IN_CLOSE (IN_CLOSE_WRITE | IN_CLOSE_NOWRITE) /* close */
+#define IN_MOVE (IN_MOVED_FROM | IN_MOVED_TO) /* moves */
+
+/* special flags */
+#define IN_ISDIR 0x40000000 /* event occurred against dir */
+#define IN_ONESHOT 0x80000000 /* only send event once */
+
+/*
+ * All of the events - we build the list by hand so that we can add flags in
+ * the future and not break backward compatibility. Apps will get only the
+ * events that they originally wanted. Be sure to add new events here!
+ */
+#define IN_ALL_EVENTS (IN_ACCESS | IN_MODIFY | IN_ATTRIB | IN_CLOSE_WRITE | \
+ IN_CLOSE_NOWRITE | IN_OPEN | IN_MOVED_FROM | \
+ IN_MOVED_TO | IN_DELETE | IN_CREATE | IN_DELETE_SELF)
+
+#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>
+
+#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_unmount_inodes(struct list_head *);
+extern void inotify_inode_is_dead(struct inode *);
+extern u32 inotify_get_cookie(void);
+
+#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_unmount_inodes(struct list_head *list)
+{
+}
+
+static inline void inotify_inode_is_dead(struct inode *inode)
+{
+}
+
+static inline u32 inotify_get_cookie(void)
+{
+ return 0;
+}
+
+#endif /* CONFIG_INOTIFY */
+
+#endif /* __KERNEL __ */
+
+#endif /* _LINUX_INOTIFY_H */
diff -urN linux-2.6.12-rc6/include/linux/sched.h linux/include/linux/sched.h
--- linux-2.6.12-rc6/include/linux/sched.h 2005-06-07 15:47:53.000000000 -0400
+++ linux/include/linux/sched.h 2005-06-13 11:28:04.000000000 -0400
@@ -404,6 +404,10 @@
atomic_t processes; /* How many processes does this user have? */
atomic_t files; /* How many open files does this user have? */
atomic_t sigpending; /* How many pending signals does this user have? */
+#ifdef CONFIG_INOTIFY
+ atomic_t inotify_watches; /* How many inotify watches does this user have? */
+ atomic_t inotify_devs; /* How many inotify devs does this user have opened? */
+#endif
/* protected by mq_lock */
unsigned long mq_bytes; /* How many bytes can be allocated to mqueue? */
unsigned long locked_shm; /* How many pages of mlocked shm ? */
diff -urN linux-2.6.12-rc6/kernel/user.c linux/kernel/user.c
--- linux-2.6.12-rc6/kernel/user.c 2005-06-07 15:47:53.000000000 -0400
+++ linux/kernel/user.c 2005-06-13 11:28:04.000000000 -0400
@@ -120,6 +120,10 @@
atomic_set(&new->processes, 0);
atomic_set(&new->files, 0);
atomic_set(&new->sigpending, 0);
+#ifdef CONFIG_INOTIFY
+ atomic_set(&new->inotify_watches, 0);
+ atomic_set(&new->inotify_devs, 0);
+#endif

new->mq_bytes = 0;
new->locked_shm = 0;