2 * Copyright (C) 2008 Red Hat, Inc., Eric Paris <eparis@redhat.com>
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)
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.
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.
20 #include <linux/init.h>
21 #include <linux/kernel.h>
22 #include <linux/module.h>
23 #include <linux/mutex.h>
24 #include <linux/spinlock.h>
26 #include <linux/atomic.h>
28 #include <linux/fsnotify_backend.h>
31 #include "../internal.h"
34 * fsnotify_unmount_inodes - an sb is unmounting. handle any watched inodes.
35 * @sb: superblock being unmounted.
37 * Called during unmount with no locks held, so needs to be safe against
38 * concurrent modifiers. We temporarily drop sb->s_inode_list_lock and CAN block.
40 void fsnotify_unmount_inodes(struct super_block *sb)
42 struct inode *inode, *iput_inode = NULL;
44 spin_lock(&sb->s_inode_list_lock);
45 list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
47 * We cannot __iget() an inode in state I_FREEING,
48 * I_WILL_FREE, or I_NEW which is fine because by that point
49 * the inode cannot have any associated watches.
51 spin_lock(&inode->i_lock);
52 if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) {
53 spin_unlock(&inode->i_lock);
58 * If i_count is zero, the inode cannot have any watches and
59 * doing an __iget/iput with MS_ACTIVE clear would actually
60 * evict all inodes with zero i_count from icache which is
61 * unnecessarily violent and may in fact be illegal to do.
63 if (!atomic_read(&inode->i_count)) {
64 spin_unlock(&inode->i_lock);
69 spin_unlock(&inode->i_lock);
70 spin_unlock(&sb->s_inode_list_lock);
75 /* for each watch, send FS_UNMOUNT and then remove it */
76 fsnotify(inode, FS_UNMOUNT, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
78 fsnotify_inode_delete(inode);
82 spin_lock(&sb->s_inode_list_lock);
84 spin_unlock(&sb->s_inode_list_lock);