Commit 2d9048e2 authored by Amy Griffis's avatar Amy Griffis Committed by Al Viro
Browse files

[PATCH] inotify (1/5): split kernel API from userspace support 



The following series of patches introduces a kernel API for inotify,
making it possible for kernel modules to benefit from inotify's
mechanism for watching inodes.  With these patches, inotify will
maintain for each caller a list of watches (via an embedded struct
inotify_watch), where each inotify_watch is associated with a
corresponding struct inode.  The caller registers an event handler and
specifies for which filesystem events their event handler should be
called per inotify_watch.

Signed-off-by: default avatarAmy Griffis <amy.griffis@hp.com>
Acked-by: default avatarRobert Love <rml@novell.com>
Acked-by: default avatarJohn McCutchan <john@johnmccutchan.com>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 90204e0b

fs/Kconfig

+18 −6
Original line number Diff line number Diff line
@@ -393,18 +393,30 @@ config INOTIFY 
	bool "Inotify file change notification support"

	default y

	---help---

	  Say Y here to enable inotify support and the associated system

	  calls.  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.  Other features

	  include multiple file events, one-shot support, and unmount

	  Say Y here to enable inotify support.  Inotify is a file change

	  notification system and a replacement for dnotify.  Inotify fixes

	  numerous shortcomings in dnotify and introduces several new features

	  including multiple file events, one-shot support, and unmount

	  notification.



	  For more information, see Documentation/filesystems/inotify.txt



	  If unsure, say Y.



config INOTIFY_USER

	bool "Inotify support for userspace"

	depends on INOTIFY

	default y

	---help---

	  Say Y here to enable inotify support for userspace, including the

	  associated system calls.  Inotify allows monitoring of both files and

	  directories via a single open fd.  Events are read from the file

	  descriptor, which is also select()- and poll()-able.



	  For more information, see Documentation/filesystems/inotify.txt



	  If unsure, say Y.



config QUOTA

	bool "Quota support"

	help

fs/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ obj-y := open.o read_write.o file_table.o buffer.o bio.o super.o \ 
		ioprio.o pnode.o drop_caches.o splice.o sync.o



obj-$(CONFIG_INOTIFY)		+= inotify.o

obj-$(CONFIG_INOTIFY_USER)	+= inotify_user.o

obj-$(CONFIG_EPOLL)		+= eventpoll.o

obj-$(CONFIG_COMPAT)		+= compat.o compat_ioctl.o

fs/inotify.c

+230 −711

File changed.

Preview size limit exceeded, changes collapsed.

fs/inotify_user.c

0 → 100644
+717 −0
Original line number Diff line number Diff line 
/*

 * fs/inotify_user.c - inotify support for userspace

 *

 * Authors:

 *	John McCutchan	<ttb@tentacle.dhs.org>

 *	Robert Love	<rml@novell.com>

 *

 * Copyright (C) 2005 John McCutchan

 * Copyright 2006 Hewlett-Packard Development Company, L.P.

 *

 * 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/kernel.h>

#include <linux/sched.h>

#include <linux/slab.h>

#include <linux/fs.h>

#include <linux/file.h>

#include <linux/mount.h>

#include <linux/namei.h>

#include <linux/poll.h>

#include <linux/init.h>

#include <linux/list.h>

#include <linux/inotify.h>

#include <linux/syscalls.h>



#include <asm/ioctls.h>



static kmem_cache_t *watch_cachep __read_mostly;

static kmem_cache_t *event_cachep __read_mostly;



static struct vfsmount *inotify_mnt __read_mostly;



/* these are configurable via /proc/sys/fs/inotify/ */

int inotify_max_user_instances __read_mostly;

int inotify_max_user_watches __read_mostly;

int inotify_max_queued_events __read_mostly;



/*

 * Lock ordering:

 *

 * inotify_dev->up_mutex (ensures we don't re-add the same watch)

 * 	inode->inotify_mutex (protects inode's watch list)

 * 		inotify_handle->mutex (protects inotify_handle's watch list)

 * 			inotify_dev->ev_mutex (protects device's event queue)

 */



/*

 * Lifetimes of the main data structures:

 *

 * inotify_device: Lifetime is managed by reference count, from

 * sys_inotify_init() until release.  Additional references can bump the count

 * via get_inotify_dev() and drop the count via put_inotify_dev().

 *

 * inotify_user_watch: Lifetime is from create_watch() to the receipt of an

 * IN_IGNORED event from inotify, or when using IN_ONESHOT, to receipt of the

 * first event, or to inotify_destroy().

 */



/*

 * struct inotify_device - represents an inotify instance

 *

 * This structure is protected by the mutex 'mutex'.

 */

struct inotify_device {

	wait_queue_head_t 	wq;		/* wait queue for i/o */

	struct mutex		ev_mutex;	/* protects event queue */

	struct mutex		up_mutex;	/* synchronizes watch updates */

	struct list_head 	events;		/* list of queued events */

	atomic_t		count;		/* reference count */

	struct user_struct	*user;		/* user who opened this dev */

	struct inotify_handle	*ih;		/* inotify handle */

	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->ev_mutex 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_user_watch - our version of an inotify_watch, we add

 * a reference to the associated inotify_device.

 */

struct inotify_user_watch {

	struct inotify_device	*dev;	/* associated device */

	struct inotify_watch	wdata;	/* inotify watch data */

};



#ifdef CONFIG_SYSCTL



#include <linux/sysctl.h>



static int zero;



ctl_table inotify_table[] = {

	{

		.ctl_name	= INOTIFY_MAX_USER_INSTANCES,

		.procname	= "max_user_instances",

		.data		= &inotify_max_user_instances,

		.maxlen		= sizeof(int),

		.mode		= 0644,

		.proc_handler	= &proc_dointvec_minmax,

		.strategy	= &sysctl_intvec,

		.extra1		= &zero,

	},

	{

		.ctl_name	= INOTIFY_MAX_USER_WATCHES,

		.procname	= "max_user_watches",

		.data		= &inotify_max_user_watches,

		.maxlen		= sizeof(int),

		.mode		= 0644,

		.proc_handler	= &proc_dointvec_minmax,

		.strategy	= &sysctl_intvec,

		.extra1		= &zero,

	},

	{

		.ctl_name	= INOTIFY_MAX_QUEUED_EVENTS,

		.procname	= "max_queued_events",

		.data		= &inotify_max_queued_events,

		.maxlen		= sizeof(int),

		.mode		= 0644,

		.proc_handler	= &proc_dointvec_minmax,

		.strategy	= &sysctl_intvec,

		.extra1		= &zero

	},

	{ .ctl_name = 0 }

};

#endif /* CONFIG_SYSCTL */



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);

	}

}



/*

 * free_inotify_user_watch - cleans up the watch and its references

 */

static void free_inotify_user_watch(struct inotify_watch *w)

{

	struct inotify_user_watch *watch;

	struct inotify_device *dev;



	watch = container_of(w, struct inotify_user_watch, wdata);

	dev = watch->dev;



	atomic_dec(&dev->user->inotify_watches);

	put_inotify_dev(dev);

	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->ev_mutex.

 */

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 - event handler registered with core inotify, adds

 * a new event to the given device

 *

 * Can sleep (calls kernel_event()).

 */

static void inotify_dev_queue_event(struct inotify_watch *w, u32 wd, u32 mask,

				    u32 cookie, const char *name)

{

	struct inotify_user_watch *watch;

	struct inotify_device *dev;

	struct inotify_kernel_event *kevent, *last;



	watch = container_of(w, struct inotify_user_watch, wdata);

	dev = watch->dev;



	mutex_lock(&dev->ev_mutex);



	/* we can safely put the watch as we don't reference it while

	 * generating the event

	 */

	if (mask & IN_IGNORED || mask & IN_ONESHOT)

		put_inotify_watch(w); /* final put */



	/* 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 == wd &&

			last->event.cookie == cookie) {

		const char *lastname = last->name;



		if (!name && !lastname)

			goto out;

		if (name && lastname && !strcmp(lastname, name))

			goto out;

	}



	/* the queue overflowed and we already sent the Q_OVERFLOW event */

	if (unlikely(dev->event_count > dev->max_events))

		goto out;



	/* 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(wd, mask, cookie, name);



	if (unlikely(!kevent))

		goto out;



	/* 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);



out:

	mutex_unlock(&dev->ev_mutex);

}



/*

 * remove_kevent - cleans up and ultimately frees the given kevent

 *

 * Caller must hold dev->ev_mutex.

 */

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->ev_mutex.

 */

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);

	}

}



/*

 * find_inode - resolve a user-given path to a specific inode and return a nd

 */

static int find_inode(const char __user *dirname, struct nameidata *nd,

		      unsigned flags)

{

	int error;



	error = __user_walk(dirname, flags, nd);

	if (error)

		return error;

	/* you can only watch an inode if you have read permissions on it */

	error = vfs_permission(nd, MAY_READ);

	if (error)

		path_release(nd);

	return error;

}



/*

 * create_watch - creates a watch on the given device.

 *

 * Callers must hold dev->up_mutex.

 */

static int create_watch(struct inotify_device *dev, struct inode *inode,

			u32 mask)

{

	struct inotify_user_watch *watch;

	int ret;



	if (atomic_read(&dev->user->inotify_watches) >=

			inotify_max_user_watches)

		return -ENOSPC;



	watch = kmem_cache_alloc(watch_cachep, GFP_KERNEL);

	if (unlikely(!watch))

		return -ENOMEM;



	/* save a reference to device and bump the count to make it official */

	get_inotify_dev(dev);

	watch->dev = dev;



	atomic_inc(&dev->user->inotify_watches);



	ret = inotify_add_watch(dev->ih, &watch->wdata, inode, mask);

	if (ret < 0)

		free_inotify_user_watch(&watch->wdata);



	return ret;

}



/* 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);

	mutex_lock(&dev->ev_mutex);

	if (!list_empty(&dev->events))

		ret = POLLIN | POLLRDNORM;

	mutex_unlock(&dev->ev_mutex);



	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);



		mutex_lock(&dev->ev_mutex);

		events = !list_empty(&dev->events);

		mutex_unlock(&dev->ev_mutex);

		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;



	mutex_lock(&dev->ev_mutex);

	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);

	}

	mutex_unlock(&dev->ev_mutex);



	return ret;

}



static int inotify_release(struct inode *ignored, struct file *file)

{

	struct inotify_device *dev = file->private_data;



	inotify_destroy(dev->ih);



	/* destroy all of the events on this device */

	mutex_lock(&dev->ev_mutex);

	while (!list_empty(&dev->events))

		inotify_dev_event_dequeue(dev);

	mutex_unlock(&dev->ev_mutex);



	/* free this device: the put matching the get in inotify_init() */

	put_inotify_dev(dev);



	return 0;

}



static long inotify_ioctl(struct file *file, unsigned int cmd,

			  unsigned long arg)

{

	struct inotify_device *dev;

	void __user *p;

	int ret = -ENOTTY;



	dev = file->private_data;

	p = (void __user *) arg;



	switch (cmd) {

	case FIONREAD:

		ret = put_user(dev->queue_size, (int __user *) p);

		break;

	}



	return ret;

}



static const struct file_operations inotify_fops = {

	.poll           = inotify_poll,

	.read           = inotify_read,

	.release        = inotify_release,

	.unlocked_ioctl = inotify_ioctl,

	.compat_ioctl	= inotify_ioctl,

};



static const struct inotify_operations inotify_user_ops = {

	.handle_event	= inotify_dev_queue_event,

	.destroy_watch	= free_inotify_user_watch,

};



asmlinkage long sys_inotify_init(void)

{

	struct inotify_device *dev;

	struct inotify_handle *ih;

	struct user_struct *user;

	struct file *filp;

	int fd, ret;



	fd = get_unused_fd();

	if (fd < 0)

		return fd;



	filp = get_empty_filp();

	if (!filp) {

		ret = -ENFILE;

		goto out_put_fd;

	}



	user = get_uid(current->user);

	if (unlikely(atomic_read(&user->inotify_devs) >=

			inotify_max_user_instances)) {

		ret = -EMFILE;

		goto out_free_uid;

	}



	dev = kmalloc(sizeof(struct inotify_device), GFP_KERNEL);

	if (unlikely(!dev)) {

		ret = -ENOMEM;

		goto out_free_uid;

	}



	ih = inotify_init(&inotify_user_ops);

	if (unlikely(IS_ERR(ih))) {

		ret = PTR_ERR(ih);

		goto out_free_dev;

	}

	dev->ih = ih;



	filp->f_op = &inotify_fops;

	filp->f_vfsmnt = mntget(inotify_mnt);

	filp->f_dentry = dget(inotify_mnt->mnt_root);

	filp->f_mapping = filp->f_dentry->d_inode->i_mapping;

	filp->f_mode = FMODE_READ;

	filp->f_flags = O_RDONLY;

	filp->private_data = dev;



	INIT_LIST_HEAD(&dev->events);

	init_waitqueue_head(&dev->wq);

	mutex_init(&dev->ev_mutex);

	mutex_init(&dev->up_mutex);

	dev->event_count = 0;

	dev->queue_size = 0;

	dev->max_events = inotify_max_queued_events;

	dev->user = user;

	atomic_set(&dev->count, 0);



	get_inotify_dev(dev);

	atomic_inc(&user->inotify_devs);

	fd_install(fd, filp);



	return fd;

out_free_dev:

	kfree(dev);

out_free_uid:

	free_uid(user);

	put_filp(filp);

out_put_fd:

	put_unused_fd(fd);

	return ret;

}



asmlinkage long sys_inotify_add_watch(int fd, const char __user *path, u32 mask)

{

	struct inode *inode;

	struct inotify_device *dev;

	struct nameidata nd;

	struct file *filp;

	int ret, fput_needed;

	unsigned flags = 0;



	filp = fget_light(fd, &fput_needed);

	if (unlikely(!filp))

		return -EBADF;



	/* verify that this is indeed an inotify instance */

	if (unlikely(filp->f_op != &inotify_fops)) {

		ret = -EINVAL;

		goto fput_and_out;

	}



	if (!(mask & IN_DONT_FOLLOW))

		flags |= LOOKUP_FOLLOW;

	if (mask & IN_ONLYDIR)

		flags |= LOOKUP_DIRECTORY;



	ret = find_inode(path, &nd, flags);

	if (unlikely(ret))

		goto fput_and_out;



	/* inode held in place by reference to nd; dev by fget on fd */

	inode = nd.dentry->d_inode;

	dev = filp->private_data;



	mutex_lock(&dev->up_mutex);

	ret = inotify_find_update_watch(dev->ih, inode, mask);

	if (ret == -ENOENT)

		ret = create_watch(dev, inode, mask);

	mutex_unlock(&dev->up_mutex);



	path_release(&nd);

fput_and_out:

	fput_light(filp, fput_needed);

	return ret;

}



asmlinkage long sys_inotify_rm_watch(int fd, u32 wd)

{

	struct file *filp;

	struct inotify_device *dev;

	int ret, fput_needed;



	filp = fget_light(fd, &fput_needed);

	if (unlikely(!filp))

		return -EBADF;



	/* verify that this is indeed an inotify instance */

	if (unlikely(filp->f_op != &inotify_fops)) {

		ret = -EINVAL;

		goto out;

	}



	dev = filp->private_data;



	/* we free our watch data when we get IN_IGNORED */

	ret = inotify_rm_wd(dev->ih, wd);



out:

	fput_light(filp, fput_needed);

	return ret;

}



static struct super_block *

inotify_get_sb(struct file_system_type *fs_type, int flags,

	       const char *dev_name, void *data)

{

    return get_sb_pseudo(fs_type, "inotify", NULL, 0xBAD1DEA);

}



static struct file_system_type inotify_fs_type = {

    .name           = "inotifyfs",

    .get_sb         = inotify_get_sb,

    .kill_sb        = kill_anon_super,

};



/*

 * inotify_user_setup - 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_user_setup(void)

{

	int ret;



	ret = register_filesystem(&inotify_fs_type);

	if (unlikely(ret))

		panic("inotify: register_filesystem returned %d!\n", ret);



	inotify_mnt = kern_mount(&inotify_fs_type);

	if (IS_ERR(inotify_mnt))

		panic("inotify: kern_mount ret %ld!\n", PTR_ERR(inotify_mnt));



	inotify_max_queued_events = 16384;

	inotify_max_user_instances = 128;

	inotify_max_user_watches = 8192;



	watch_cachep = kmem_cache_create("inotify_watch_cache",

					 sizeof(struct inotify_user_watch),

					 0, SLAB_PANIC, NULL, NULL);

	event_cachep = kmem_cache_create("inotify_event_cache",

					 sizeof(struct inotify_kernel_event),

					 0, SLAB_PANIC, NULL, NULL);



	return 0;

}



module_init(inotify_user_setup);

include/linux/inotify.h

+76 −0
Original line number Diff line number Diff line
@@ -68,8 +68,37 @@ struct inotify_event { 
#include <linux/dcache.h>

#include <linux/fs.h>



/*

 * struct inotify_watch - represents a watch request on a specific inode

 *

 * h_list is protected by ih->mutex of the associated inotify_handle.

 * i_list, mask are protected by inode->inotify_mutex of the associated inode.

 * ih, inode, and wd are never written to once the watch is created.

 *

 * Callers must use the established inotify interfaces to access inotify_watch

 * contents.  The content of this structure is private to the inotify

 * implementation.

 */

struct inotify_watch {

	struct list_head	h_list;	/* entry in inotify_handle's list */

	struct list_head	i_list;	/* entry in inode's list */

	atomic_t		count;	/* reference count */

	struct inotify_handle	*ih;	/* associated inotify handle */

	struct inode		*inode;	/* associated inode */

	__s32			wd;	/* watch descriptor */

	__u32			mask;	/* event mask for this watch */

};



struct inotify_operations {

	void (*handle_event)(struct inotify_watch *, u32, u32, u32,

			     const char *);

	void (*destroy_watch)(struct inotify_watch *);

};



#ifdef CONFIG_INOTIFY



/* Kernel API for producing events */



extern void inotify_d_instantiate(struct dentry *, struct inode *);

extern void inotify_d_move(struct dentry *);

extern void inotify_inode_queue_event(struct inode *, __u32, __u32,
@@ -80,6 +109,18 @@ extern void inotify_unmount_inodes(struct list_head *); 
extern void inotify_inode_is_dead(struct inode *);

extern u32 inotify_get_cookie(void);



/* Kernel Consumer API */



extern struct inotify_handle *inotify_init(const struct inotify_operations *);

extern void inotify_destroy(struct inotify_handle *);

extern __s32 inotify_find_update_watch(struct inotify_handle *, struct inode *,

				       u32);

extern __s32 inotify_add_watch(struct inotify_handle *, struct inotify_watch *,

			       struct inode *, __u32);

extern int inotify_rm_wd(struct inotify_handle *, __u32);

extern void get_inotify_watch(struct inotify_watch *);

extern void put_inotify_watch(struct inotify_watch *);



#else



static inline void inotify_d_instantiate(struct dentry *dentry,
@@ -116,6 +157,41 @@ static inline u32 inotify_get_cookie(void) 
	return 0;

}



static inline struct inotify_handle *inotify_init(const struct inotify_operations *ops)

{

	return ERR_PTR(-EOPNOTSUPP);

}



static inline void inotify_destroy(struct inotify_handle *ih)

{

}



static inline __s32 inotify_find_update_watch(struct inotify_handle *ih,

					      struct inode *inode, u32 mask)

{

	return -EOPNOTSUPP;

}



static inline __s32 inotify_add_watch(struct inotify_handle *ih,

				      struct inotify_watch *watch,

				      struct inode *inode, __u32 mask)

{

	return -EOPNOTSUPP;

}



static inline int inotify_rm_wd(struct inotify_handle *ih, __u32 wd)

{

	return -EOPNOTSUPP;

}



static inline void get_inotify_watch(struct inotify_watch *watch)

{

}



static inline void put_inotify_watch(struct inotify_watch *watch)

{

}



#endif	/* CONFIG_INOTIFY */



#endif	/* __KERNEL __ */

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