diff options
Diffstat (limited to 'fs/notify/inotify/inotify_fsnotify.c')
| -rw-r--r-- | fs/notify/inotify/inotify_fsnotify.c | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/fs/notify/inotify/inotify_fsnotify.c b/fs/notify/inotify/inotify_fsnotify.c new file mode 100644 index 000000000000..7ef75b83247e --- /dev/null +++ b/fs/notify/inotify/inotify_fsnotify.c @@ -0,0 +1,138 @@ +/* + * 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, +}; |