/*
* 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.
*
* Copyright (C) 2009 Eric Paris <Red Hat Inc>
* inotify was largely rewriten to make use of the fsnotify infrastructure
*
* 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/fs.h> /* struct inode */
#include <linux/fsnotify_backend.h>
#include <linux/inotify.h>
#include <linux/path.h> /* struct path */
#include <linux/slab.h> /* kmem_* */
#include <linux/types.h>
#include "inotify.h"
static int inotify_handle_event(struct fsnotify_group *group, struct fsnotify_event *event)
{
struct fsnotify_mark_entry *entry;
struct inotify_inode_mark_entry *ientry;
struct inode *to_tell;
struct inotify_event_private_data *event_priv;
struct fsnotify_event_private_data *fsn_event_priv;
int wd, ret;
to_tell = event->to_tell;
spin_lock(&to_tell->i_lock);
entry = fsnotify_find_mark_entry(group, to_tell);
spin_unlock(&to_tell->i_lock);
/* race with watch removal? We already passes should_send */
if (unlikely(!entry))
return 0;
ientry = container_of(entry, struct inotify_inode_mark_entry,
fsn_entry);
wd = ientry->wd;
event_priv = kmem_cache_alloc(event_priv_cachep, GFP_KERNEL);
if (unlikely(!event_priv))
return -ENOMEM;
fsn_event_priv = &event_priv->fsnotify_event_priv_data;
fsn_event_priv->group = group;
event_priv->wd = wd;
ret = fsnotify_add_notify_event(group, event, fsn_event_priv);
/* EEXIST is not an error */
if (ret == -EEXIST)
ret = 0;
/* did event_priv get attached? */
if (list_empty(&fsn_event_priv->event_list))
inotify_free_event_priv(fsn_event_priv);
/*
* If we hold the entry until after the event is on the queue
* IN_IGNORED won't be able to pass this event in the queue
*/
fsnotify_put_mark(entry);
return ret;
}
static void inotify_freeing_mark(struct fsnotify_mark_entry *entry, struct fsnotify_group *group)
{
inotify_destroy_mark_entry(entry, group);
}
static bool inotify_should_send_event(struct fsnotify_group *group, struct inode *inode, __u32 mask)
{
struct fsnotify_mark_entry *entry;
bool send;
spin_lock(&inode->i_lock);
entry = fsnotify_find_mark_entry(group, inode);
spin_unlock(&inode->i_lock);
if (!entry)
return false;
mask = (mask & ~FS_EVENT_ON_CHILD);
send = (entry->mask & mask);
/* find took a reference */
fsnotify_put_mark(entry);
return send;
}
static int idr_callback(int id, void *p, void *data)
{
BUG();
return 0;
}
static void inotify_free_group_priv(struct fsnotify_group *group)
{
/* ideally the idr is empty and we won't hit the BUG in teh callback */
idr_for_each(&group->inotify_data.idr, idr_callback, NULL);
idr_remove_all(&group->inotify_data.idr);
idr_destroy(&group->inotify_data.idr);
}
void inotify_free_event_priv(struct fsnotify_event_private_data *fsn_event_priv)
{
struct inotify_event_private_data *event_priv;
event_priv = container_of(fsn_event_priv, struct inotify_event_private_data,
fsnotify_event_priv_data);
kmem_cache_free(event_priv_cachep, event_priv);
}
const struct fsnotify_ops inotify_fsnotify_ops = {
.handle_event = inotify_handle_event,
.should_send_event = inotify_should_send_event,
.free_group_priv = inotify_free_group_priv,
.free_event_priv = inotify_free_event_priv,
.freeing_mark = inotify_freeing_mark,
};
