forked from Minki/linux
eef3a116be
inotify decides if private data it passed to get added to an event was used by checking list_empty(). But it's possible that the event may have been dequeued and the private event removed so it would look empty. The fix is to use the return code from fsnotify_add_notify_event rather than looking at the list. Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
140 lines
3.8 KiB
C
140 lines
3.8 KiB
C
/*
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* fs/inotify_user.c - inotify support for userspace
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*
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* Authors:
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* John McCutchan <ttb@tentacle.dhs.org>
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* Robert Love <rml@novell.com>
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*
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* Copyright (C) 2005 John McCutchan
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* Copyright 2006 Hewlett-Packard Development Company, L.P.
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*
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* Copyright (C) 2009 Eric Paris <Red Hat Inc>
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* inotify was largely rewriten to make use of the fsnotify infrastructure
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2, or (at your option) any
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* later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*/
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#include <linux/fs.h> /* struct inode */
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#include <linux/fsnotify_backend.h>
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#include <linux/inotify.h>
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#include <linux/path.h> /* struct path */
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#include <linux/slab.h> /* kmem_* */
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#include <linux/types.h>
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#include "inotify.h"
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static int inotify_handle_event(struct fsnotify_group *group, struct fsnotify_event *event)
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{
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struct fsnotify_mark_entry *entry;
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struct inotify_inode_mark_entry *ientry;
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struct inode *to_tell;
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struct inotify_event_private_data *event_priv;
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struct fsnotify_event_private_data *fsn_event_priv;
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int wd, ret;
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to_tell = event->to_tell;
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spin_lock(&to_tell->i_lock);
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entry = fsnotify_find_mark_entry(group, to_tell);
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spin_unlock(&to_tell->i_lock);
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/* race with watch removal? We already passes should_send */
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if (unlikely(!entry))
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return 0;
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ientry = container_of(entry, struct inotify_inode_mark_entry,
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fsn_entry);
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wd = ientry->wd;
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event_priv = kmem_cache_alloc(event_priv_cachep, GFP_KERNEL);
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if (unlikely(!event_priv))
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return -ENOMEM;
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fsn_event_priv = &event_priv->fsnotify_event_priv_data;
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fsn_event_priv->group = group;
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event_priv->wd = wd;
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ret = fsnotify_add_notify_event(group, event, fsn_event_priv);
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if (ret) {
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inotify_free_event_priv(fsn_event_priv);
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/* EEXIST says we tail matched, EOVERFLOW isn't something
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* to report up the stack. */
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if ((ret == -EEXIST) ||
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(ret == -EOVERFLOW))
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ret = 0;
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}
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/*
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* If we hold the entry until after the event is on the queue
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* IN_IGNORED won't be able to pass this event in the queue
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*/
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fsnotify_put_mark(entry);
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return ret;
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}
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static void inotify_freeing_mark(struct fsnotify_mark_entry *entry, struct fsnotify_group *group)
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{
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inotify_ignored_and_remove_idr(entry, group);
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}
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static bool inotify_should_send_event(struct fsnotify_group *group, struct inode *inode, __u32 mask)
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{
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struct fsnotify_mark_entry *entry;
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bool send;
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spin_lock(&inode->i_lock);
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entry = fsnotify_find_mark_entry(group, inode);
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spin_unlock(&inode->i_lock);
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if (!entry)
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return false;
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mask = (mask & ~FS_EVENT_ON_CHILD);
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send = (entry->mask & mask);
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/* find took a reference */
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fsnotify_put_mark(entry);
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return send;
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}
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static int idr_callback(int id, void *p, void *data)
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{
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BUG();
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return 0;
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}
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static void inotify_free_group_priv(struct fsnotify_group *group)
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{
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/* ideally the idr is empty and we won't hit the BUG in teh callback */
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idr_for_each(&group->inotify_data.idr, idr_callback, NULL);
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idr_remove_all(&group->inotify_data.idr);
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idr_destroy(&group->inotify_data.idr);
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}
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void inotify_free_event_priv(struct fsnotify_event_private_data *fsn_event_priv)
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{
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struct inotify_event_private_data *event_priv;
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event_priv = container_of(fsn_event_priv, struct inotify_event_private_data,
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fsnotify_event_priv_data);
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kmem_cache_free(event_priv_cachep, event_priv);
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}
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const struct fsnotify_ops inotify_fsnotify_ops = {
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.handle_event = inotify_handle_event,
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.should_send_event = inotify_should_send_event,
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.free_group_priv = inotify_free_group_priv,
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.free_event_priv = inotify_free_event_priv,
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.freeing_mark = inotify_freeing_mark,
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};
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