[net-next-2.6.git] / fs / notify / fsnotify.c

/*
 *  Copyright (C) 2008 Red Hat, Inc., Eric Paris <eparis@redhat.com>
 *
 *  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.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; see the file COPYING.  If not, write to
 *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/dcache.h>
#include <linux/fs.h>
#include <linux/gfp.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/mount.h>
#include <linux/srcu.h>

#include <linux/fsnotify_backend.h>
#include "fsnotify.h"

/*
 * Clear all of the marks on an inode when it is being evicted from core
 */
void __fsnotify_inode_delete(struct inode *inode)
{
	fsnotify_clear_marks_by_inode(inode);
}
EXPORT_SYMBOL_GPL(__fsnotify_inode_delete);

void __fsnotify_vfsmount_delete(struct vfsmount *mnt)
{
	fsnotify_clear_marks_by_mount(mnt);
}

/*
 * Given an inode, first check if we care what happens to our children.  Inotify
 * and dnotify both tell their parents about events.  If we care about any event
 * on a child we run all of our children and set a dentry flag saying that the
 * parent cares.  Thus when an event happens on a child it can quickly tell if
 * if there is a need to find a parent and send the event to the parent.
 */
void __fsnotify_update_child_dentry_flags(struct inode *inode)
{
	struct dentry *alias;
	int watched;

	if (!S_ISDIR(inode->i_mode))
		return;

	/* determine if the children should tell inode about their events */
	watched = fsnotify_inode_watches_children(inode);

	spin_lock(&dcache_lock);
	/* run all of the dentries associated with this inode.  Since this is a
	 * directory, there damn well better only be one item on this list */
	list_for_each_entry(alias, &inode->i_dentry, d_alias) {
		struct dentry *child;

		/* run all of the children of the original inode and fix their
		 * d_flags to indicate parental interest (their parent is the
		 * original inode) */
		list_for_each_entry(child, &alias->d_subdirs, d_u.d_child) {
			if (!child->d_inode)
				continue;

			spin_lock(&child->d_lock);
			if (watched)
				child->d_flags |= DCACHE_FSNOTIFY_PARENT_WATCHED;
			else
				child->d_flags &= ~DCACHE_FSNOTIFY_PARENT_WATCHED;
			spin_unlock(&child->d_lock);
		}
	}
	spin_unlock(&dcache_lock);
}

/* Notify this dentry's parent about a child's events. */
int __fsnotify_parent(struct path *path, struct dentry *dentry, __u32 mask)
{
	struct dentry *parent;
	struct inode *p_inode;
	int ret = 0;

	if (!dentry)
		dentry = path->dentry;

	if (!(dentry->d_flags & DCACHE_FSNOTIFY_PARENT_WATCHED))
		return 0;

	parent = dget_parent(dentry);
	p_inode = parent->d_inode;

	if (unlikely(!fsnotify_inode_watches_children(p_inode)))
		__fsnotify_update_child_dentry_flags(p_inode);
	else if (p_inode->i_fsnotify_mask & mask) {
		/* we are notifying a parent so come up with the new mask which
		 * specifies these are events which came from a child. */
		mask |= FS_EVENT_ON_CHILD;

		if (path)
			ret = fsnotify(p_inode, mask, path, FSNOTIFY_EVENT_PATH,
				       dentry->d_name.name, 0);
		else
			ret = fsnotify(p_inode, mask, dentry->d_inode, FSNOTIFY_EVENT_INODE,
				       dentry->d_name.name, 0);
	}

	dput(parent);

	return ret;
}
EXPORT_SYMBOL_GPL(__fsnotify_parent);

static int send_to_group(struct inode *to_tell, struct vfsmount *mnt,
			 struct fsnotify_mark *inode_mark,
			 struct fsnotify_mark *vfsmount_mark,
			 __u32 mask, void *data,
			 int data_is, u32 cookie,
			 const unsigned char *file_name,
			 struct fsnotify_event **event)
{
	struct fsnotify_group *group = NULL;
	__u32 inode_test_mask = 0;
	__u32 vfsmount_test_mask = 0;

	if (unlikely(!inode_mark && !vfsmount_mark)) {
		BUG();
		return 0;
	}

	/* clear ignored on inode modification */
	if (mask & FS_MODIFY) {
		if (inode_mark &&
		    !(inode_mark->flags & FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY))
			inode_mark->ignored_mask = 0;
		if (vfsmount_mark &&
		    !(vfsmount_mark->flags & FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY))
			vfsmount_mark->ignored_mask = 0;
	}

	/* does the inode mark tell us to do something? */
	if (inode_mark) {
		group = inode_mark->group;
		inode_test_mask = (mask & ~FS_EVENT_ON_CHILD);
		inode_test_mask &= inode_mark->mask;
		inode_test_mask &= ~inode_mark->ignored_mask;
	}

	/* does the vfsmount_mark tell us to do something? */
	if (vfsmount_mark) {
		vfsmount_test_mask = (mask & ~FS_EVENT_ON_CHILD);
		group = vfsmount_mark->group;
		vfsmount_test_mask &= vfsmount_mark->mask;
		vfsmount_test_mask &= ~vfsmount_mark->ignored_mask;
		if (inode_mark)
			vfsmount_test_mask &= ~inode_mark->ignored_mask;
	}

	pr_debug("%s: group=%p to_tell=%p mnt=%p mask=%x inode_mark=%p"
		 " inode_test_mask=%x vfsmount_mark=%p vfsmount_test_mask=%x"
		 " data=%p data_is=%d cookie=%d event=%p\n",
		 __func__, group, to_tell, mnt, mask, inode_mark,
		 inode_test_mask, vfsmount_mark, vfsmount_test_mask, data,
		 data_is, cookie, *event);

	if (!inode_test_mask && !vfsmount_test_mask)
		return 0;

	if (group->ops->should_send_event(group, to_tell, inode_mark,
					  vfsmount_mark, mask, data,
					  data_is) == false)
		return 0;

	if (!*event) {
		*event = fsnotify_create_event(to_tell, mask, data,
						data_is, file_name,
						cookie, GFP_KERNEL);
		if (!*event)
			return -ENOMEM;
	}
	return group->ops->handle_event(group, inode_mark, vfsmount_mark, *event);
}

/*
 * This is the main call to fsnotify.  The VFS calls into hook specific functions
 * in linux/fsnotify.h.  Those functions then in turn call here.  Here will call
 * out to all of the registered fsnotify_group.  Those groups can then use the
 * notification event in whatever means they feel necessary.
 */
int fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is,
	     const unsigned char *file_name, u32 cookie)
{
	struct hlist_node *inode_node = NULL, *vfsmount_node = NULL;
	struct fsnotify_mark *inode_mark = NULL, *vfsmount_mark = NULL;
	struct fsnotify_group *inode_group, *vfsmount_group;
	struct fsnotify_event *event = NULL;
	struct vfsmount *mnt;
	int idx, ret = 0;
	/* global tests shouldn't care about events on child only the specific event */
	__u32 test_mask = (mask & ~FS_EVENT_ON_CHILD);

	if (data_is == FSNOTIFY_EVENT_PATH)
		mnt = ((struct path *)data)->mnt;
	else
		mnt = NULL;

	/*
	 * if this is a modify event we may need to clear the ignored masks
	 * otherwise return if neither the inode nor the vfsmount care about
	 * this type of event.
	 */
	if (!(mask & FS_MODIFY) &&
	    !(test_mask & to_tell->i_fsnotify_mask) &&
	    !(mnt && test_mask & mnt->mnt_fsnotify_mask))
		return 0;

	idx = srcu_read_lock(&fsnotify_mark_srcu);

	if ((mask & FS_MODIFY) ||
	    (test_mask & to_tell->i_fsnotify_mask))
		inode_node = srcu_dereference(to_tell->i_fsnotify_marks.first,
					      &fsnotify_mark_srcu);

	if (mnt && ((mask & FS_MODIFY) ||
		    (test_mask & mnt->mnt_fsnotify_mask))) {
		vfsmount_node = srcu_dereference(mnt->mnt_fsnotify_marks.first,
						 &fsnotify_mark_srcu);
		inode_node = srcu_dereference(to_tell->i_fsnotify_marks.first,
					      &fsnotify_mark_srcu);
	}

	while (inode_node || vfsmount_node) {
		inode_group = vfsmount_group = NULL;

		if (inode_node) {
			inode_mark = hlist_entry(srcu_dereference(inode_node, &fsnotify_mark_srcu),
						 struct fsnotify_mark, i.i_list);
			inode_group = inode_mark->group;
		}

		if (vfsmount_node) {
			vfsmount_mark = hlist_entry(srcu_dereference(vfsmount_node, &fsnotify_mark_srcu),
							struct fsnotify_mark, m.m_list);
			vfsmount_group = vfsmount_mark->group;
		}

		if (inode_group > vfsmount_group) {
			/* handle inode */
			ret = send_to_group(to_tell, NULL, inode_mark, NULL, mask, data,
					    data_is, cookie, file_name, &event);
			/* we didn't use the vfsmount_mark */
			vfsmount_group = NULL;
		} else if (vfsmount_group > inode_group) {
			ret = send_to_group(to_tell, mnt, NULL, vfsmount_mark, mask, data,
					    data_is, cookie, file_name, &event);
			inode_group = NULL;
		} else {
			ret = send_to_group(to_tell, mnt, inode_mark, vfsmount_mark,
					    mask, data, data_is, cookie, file_name,
					    &event);
		}

		if (ret && (mask & ALL_FSNOTIFY_PERM_EVENTS))
			goto out;

		if (inode_group)
			inode_node = srcu_dereference(inode_node->next,
						      &fsnotify_mark_srcu);
		if (vfsmount_group)
			vfsmount_node = srcu_dereference(vfsmount_node->next,
							 &fsnotify_mark_srcu);
	}
	ret = 0;
out:
	srcu_read_unlock(&fsnotify_mark_srcu, idx);
	/*
	 * fsnotify_create_event() took a reference so the event can't be cleaned
	 * up while we are still trying to add it to lists, drop that one.
	 */
	if (event)
		fsnotify_put_event(event);

	return ret;
}
EXPORT_SYMBOL_GPL(fsnotify);

static __init int fsnotify_init(void)
{
	int ret;

	BUG_ON(hweight32(ALL_FSNOTIFY_EVENTS) != 23);

	ret = init_srcu_struct(&fsnotify_mark_srcu);
	if (ret)
		panic("initializing fsnotify_mark_srcu");

	return 0;
}
core_initcall(fsnotify_init);
Commit	Line	Data
90586523 EP	1	/*
	2	* Copyright (C) 2008 Red Hat, Inc., Eric Paris <eparis@redhat.com>
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License as published by
	6	* the Free Software Foundation; either version 2, or (at your option)
	7	* any later version.
	8	*
	9	* This program is distributed in the hope that it will be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
	13	*
	14	* You should have received a copy of the GNU General Public License
	15	* along with this program; see the file COPYING. If not, write to
	16	* the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
	17	*/
	18
	19	#include <linux/dcache.h>
	20	#include <linux/fs.h>
5a0e3ad6	21	#include <linux/gfp.h>
90586523 EP	22	#include <linux/init.h>
90586523 EP	23	#include <linux/module.h>
7131485a	24	#include <linux/mount.h>
90586523 EP	25	#include <linux/srcu.h>
	26
	27	#include <linux/fsnotify_backend.h>
	28	#include "fsnotify.h"
	29
3be25f49 EP	30	/*
	31	* Clear all of the marks on an inode when it is being evicted from core
	32	*/
	33	void __fsnotify_inode_delete(struct inode *inode)
	34	{
	35	fsnotify_clear_marks_by_inode(inode);
	36	}
	37	EXPORT_SYMBOL_GPL(__fsnotify_inode_delete);
	38
ca9c726e AG	39	void __fsnotify_vfsmount_delete(struct vfsmount *mnt)
	40	{
	41	fsnotify_clear_marks_by_mount(mnt);
	42	}
	43
c28f7e56 EP	44	/*
	45	* Given an inode, first check if we care what happens to our children. Inotify
	46	* and dnotify both tell their parents about events. If we care about any event
	47	* on a child we run all of our children and set a dentry flag saying that the
	48	* parent cares. Thus when an event happens on a child it can quickly tell if
	49	* if there is a need to find a parent and send the event to the parent.
	50	*/
	51	void __fsnotify_update_child_dentry_flags(struct inode *inode)
	52	{
	53	struct dentry *alias;
	54	int watched;
	55
	56	if (!S_ISDIR(inode->i_mode))
	57	return;
	58
	59	/* determine if the children should tell inode about their events */
	60	watched = fsnotify_inode_watches_children(inode);
	61
	62	spin_lock(&dcache_lock);
	63	/* run all of the dentries associated with this inode. Since this is a
	64	* directory, there damn well better only be one item on this list */
	65	list_for_each_entry(alias, &inode->i_dentry, d_alias) {
	66	struct dentry *child;
	67
	68	/* run all of the children of the original inode and fix their
	69	* d_flags to indicate parental interest (their parent is the
	70	* original inode) */
	71	list_for_each_entry(child, &alias->d_subdirs, d_u.d_child) {
	72	if (!child->d_inode)
	73	continue;
	74
	75	spin_lock(&child->d_lock);
	76	if (watched)
	77	child->d_flags \|= DCACHE_FSNOTIFY_PARENT_WATCHED;
	78	else
	79	child->d_flags &= ~DCACHE_FSNOTIFY_PARENT_WATCHED;
	80	spin_unlock(&child->d_lock);
	81	}
	82	}
	83	spin_unlock(&dcache_lock);
	84	}
	85
	86	/* Notify this dentry's parent about a child's events. */
52420392	87	int __fsnotify_parent(struct path path, struct dentry dentry, __u32 mask)
c28f7e56 EP	88	{
	89	struct dentry *parent;
	90	struct inode *p_inode;
52420392	91	int ret = 0;
c28f7e56	92
72acc854	93	if (!dentry)
2069601b	94	dentry = path->dentry;
28c60e37	95
c28f7e56	96	if (!(dentry->d_flags & DCACHE_FSNOTIFY_PARENT_WATCHED))
52420392	97	return 0;
c28f7e56	98
4d4eb366	99	parent = dget_parent(dentry);
c28f7e56 EP	100	p_inode = parent->d_inode;
c28f7e56 EP	101
4d4eb366 CH	102	if (unlikely(!fsnotify_inode_watches_children(p_inode)))
	103	__fsnotify_update_child_dentry_flags(p_inode);
	104	else if (p_inode->i_fsnotify_mask & mask) {
c28f7e56 EP	105	/* we are notifying a parent so come up with the new mask which
	106	* specifies these are events which came from a child. */
	107	mask \|= FS_EVENT_ON_CHILD;
	108
2069601b	109	if (path)
52420392 EP	110	ret = fsnotify(p_inode, mask, path, FSNOTIFY_EVENT_PATH,
52420392 EP	111	dentry->d_name.name, 0);
28c60e37	112	else
52420392 EP	113	ret = fsnotify(p_inode, mask, dentry->d_inode, FSNOTIFY_EVENT_INODE,
52420392 EP	114	dentry->d_name.name, 0);
c28f7e56 EP	115	}
c28f7e56 EP	116
4d4eb366	117	dput(parent);
52420392 EP	118
52420392 EP	119	return ret;
c28f7e56 EP	120	}
	121	EXPORT_SYMBOL_GPL(__fsnotify_parent);
	122
613a807f	123	static int send_to_group(struct inode to_tell, struct vfsmount mnt,
ce8f76fb EP	124	struct fsnotify_mark *inode_mark,
	125	struct fsnotify_mark *vfsmount_mark,
	126	__u32 mask, void *data,
613a807f	127	int data_is, u32 cookie,
3a9b16b4	128	const unsigned char *file_name,
c4ec54b4	129	struct fsnotify_event **event)
7131485a	130	{
faa9560a	131	struct fsnotify_group *group = NULL;
84e1ab4d EP	132	__u32 inode_test_mask = 0;
84e1ab4d EP	133	__u32 vfsmount_test_mask = 0;
613a807f	134
faa9560a EP	135	if (unlikely(!inode_mark && !vfsmount_mark)) {
	136	BUG();
	137	return 0;
	138	}
ce8f76fb EP	139
	140	/* clear ignored on inode modification */
	141	if (mask & FS_MODIFY) {
	142	if (inode_mark &&
	143	!(inode_mark->flags & FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY))
	144	inode_mark->ignored_mask = 0;
	145	if (vfsmount_mark &&
	146	!(vfsmount_mark->flags & FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY))
	147	vfsmount_mark->ignored_mask = 0;
	148	}
5ba08e2e	149
ce8f76fb EP	150	/* does the inode mark tell us to do something? */
ce8f76fb EP	151	if (inode_mark) {
faa9560a	152	group = inode_mark->group;
84e1ab4d	153	inode_test_mask = (mask & ~FS_EVENT_ON_CHILD);
ce8f76fb EP	154	inode_test_mask &= inode_mark->mask;
	155	inode_test_mask &= ~inode_mark->ignored_mask;
	156	}
613a807f	157
ce8f76fb EP	158	/* does the vfsmount_mark tell us to do something? */
ce8f76fb EP	159	if (vfsmount_mark) {
84e1ab4d	160	vfsmount_test_mask = (mask & ~FS_EVENT_ON_CHILD);
faa9560a	161	group = vfsmount_mark->group;
ce8f76fb EP	162	vfsmount_test_mask &= vfsmount_mark->mask;
	163	vfsmount_test_mask &= ~vfsmount_mark->ignored_mask;
	164	if (inode_mark)
	165	vfsmount_test_mask &= ~inode_mark->ignored_mask;
	166	}
	167
84e1ab4d EP	168	pr_debug("%s: group=%p to_tell=%p mnt=%p mask=%x inode_mark=%p"
	169	" inode_test_mask=%x vfsmount_mark=%p vfsmount_test_mask=%x"
	170	" data=%p data_is=%d cookie=%d event=%p\n",
	171	__func__, group, to_tell, mnt, mask, inode_mark,
	172	inode_test_mask, vfsmount_mark, vfsmount_test_mask, data,
	173	data_is, cookie, *event);
faa9560a	174
ce8f76fb	175	if (!inode_test_mask && !vfsmount_test_mask)
613a807f EP	176	return 0;
613a807f EP	177
1968f5ee	178	if (group->ops->should_send_event(group, to_tell, inode_mark,
ce8f76fb EP	179	vfsmount_mark, mask, data,
ce8f76fb EP	180	data_is) == false)
c4ec54b4	181	return 0;
613a807f	182
7131485a EP	183	if (!*event) {
	184	*event = fsnotify_create_event(to_tell, mask, data,
	185	data_is, file_name,
	186	cookie, GFP_KERNEL);
7131485a	187	if (!*event)
c4ec54b4	188	return -ENOMEM;
7131485a	189	}
ce8f76fb	190	return group->ops->handle_event(group, inode_mark, vfsmount_mark, *event);
7131485a EP	191	}
7131485a EP	192
90586523 EP	193	/*
	194	* This is the main call to fsnotify. The VFS calls into hook specific functions
	195	* in linux/fsnotify.h. Those functions then in turn call here. Here will call
	196	* out to all of the registered fsnotify_group. Those groups can then use the
	197	* notification event in whatever means they feel necessary.
	198	*/
c4ec54b4 EP	199	int fsnotify(struct inode to_tell, __u32 mask, void data, int data_is,
c4ec54b4 EP	200	const unsigned char *file_name, u32 cookie)
90586523	201	{
84e1ab4d	202	struct hlist_node inode_node = NULL, vfsmount_node = NULL;
613a807f EP	203	struct fsnotify_mark inode_mark = NULL, vfsmount_mark = NULL;
613a807f EP	204	struct fsnotify_group inode_group, vfsmount_group;
90586523	205	struct fsnotify_event *event = NULL;
613a807f	206	struct vfsmount *mnt;
c4ec54b4	207	int idx, ret = 0;
e42e2773 EP	208	/* global tests shouldn't care about events on child only the specific event */
e42e2773 EP	209	__u32 test_mask = (mask & ~FS_EVENT_ON_CHILD);
90586523	210
2069601b LT	211	if (data_is == FSNOTIFY_EVENT_PATH)
2069601b LT	212	mnt = ((struct path *)data)->mnt;
613a807f EP	213	else
	214	mnt = NULL;
	215
	216	/*
	217	* if this is a modify event we may need to clear the ignored masks
	218	* otherwise return if neither the inode nor the vfsmount care about
	219	* this type of event.
	220	*/
	221	if (!(mask & FS_MODIFY) &&
	222	!(test_mask & to_tell->i_fsnotify_mask) &&
	223	!(mnt && test_mask & mnt->mnt_fsnotify_mask))
	224	return 0;
3a9fb89f	225
75c1be48	226	idx = srcu_read_lock(&fsnotify_mark_srcu);
7131485a	227
613a807f EP	228	if ((mask & FS_MODIFY) \|\|
613a807f EP	229	(test_mask & to_tell->i_fsnotify_mask))
ce8f76fb EP	230	inode_node = srcu_dereference(to_tell->i_fsnotify_marks.first,
ce8f76fb EP	231	&fsnotify_mark_srcu);
613a807f	232
84e1ab4d EP	233	if (mnt && ((mask & FS_MODIFY) \|\|
	234	(test_mask & mnt->mnt_fsnotify_mask))) {
	235	vfsmount_node = srcu_dereference(mnt->mnt_fsnotify_marks.first,
	236	&fsnotify_mark_srcu);
	237	inode_node = srcu_dereference(to_tell->i_fsnotify_marks.first,
	238	&fsnotify_mark_srcu);
90586523	239	}
75c1be48	240
613a807f	241	while (inode_node \|\| vfsmount_node) {
f72adfd5	242	inode_group = vfsmount_group = NULL;
5f3f259f	243
613a807f EP	244	if (inode_node) {
	245	inode_mark = hlist_entry(srcu_dereference(inode_node, &fsnotify_mark_srcu),
	246	struct fsnotify_mark, i.i_list);
	247	inode_group = inode_mark->group;
f72adfd5	248	}
613a807f EP	249
	250	if (vfsmount_node) {
	251	vfsmount_mark = hlist_entry(srcu_dereference(vfsmount_node, &fsnotify_mark_srcu),
	252	struct fsnotify_mark, m.m_list);
	253	vfsmount_group = vfsmount_mark->group;
f72adfd5	254	}
613a807f	255
f72adfd5	256	if (inode_group > vfsmount_group) {
613a807f	257	/* handle inode */
ff8bcbd0 EP	258	ret = send_to_group(to_tell, NULL, inode_mark, NULL, mask, data,
ff8bcbd0 EP	259	data_is, cookie, file_name, &event);
92b4678e EP	260	/* we didn't use the vfsmount_mark */
92b4678e EP	261	vfsmount_group = NULL;
f72adfd5	262	} else if (vfsmount_group > inode_group) {
ff8bcbd0 EP	263	ret = send_to_group(to_tell, mnt, NULL, vfsmount_mark, mask, data,
ff8bcbd0 EP	264	data_is, cookie, file_name, &event);
92b4678e	265	inode_group = NULL;
613a807f	266	} else {
ff8bcbd0 EP	267	ret = send_to_group(to_tell, mnt, inode_mark, vfsmount_mark,
	268	mask, data, data_is, cookie, file_name,
	269	&event);
7131485a	270	}
613a807f	271
ff8bcbd0 EP	272	if (ret && (mask & ALL_FSNOTIFY_PERM_EVENTS))
	273	goto out;
	274
92b4678e	275	if (inode_group)
ce8f76fb EP	276	inode_node = srcu_dereference(inode_node->next,
ce8f76fb EP	277	&fsnotify_mark_srcu);
92b4678e	278	if (vfsmount_group)
ce8f76fb EP	279	vfsmount_node = srcu_dereference(vfsmount_node->next,
ce8f76fb EP	280	&fsnotify_mark_srcu);
7131485a	281	}
ff8bcbd0 EP	282	ret = 0;
ff8bcbd0 EP	283	out:
75c1be48	284	srcu_read_unlock(&fsnotify_mark_srcu, idx);
90586523 EP	285	/*
	286	* fsnotify_create_event() took a reference so the event can't be cleaned
	287	* up while we are still trying to add it to lists, drop that one.
	288	*/
	289	if (event)
	290	fsnotify_put_event(event);
c4ec54b4	291
98b5c10d	292	return ret;
90586523 EP	293	}
	294	EXPORT_SYMBOL_GPL(fsnotify);
	295
	296	static __init int fsnotify_init(void)
	297	{
75c1be48 EP	298	int ret;
75c1be48 EP	299
20dee624 EP	300	BUG_ON(hweight32(ALL_FSNOTIFY_EVENTS) != 23);
20dee624 EP	301
75c1be48 EP	302	ret = init_srcu_struct(&fsnotify_mark_srcu);
	303	if (ret)
	304	panic("initializing fsnotify_mark_srcu");
	305
	306	return 0;
90586523	307	}
75c1be48	308	core_initcall(fsnotify_init);