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/mount.h>
24 #include <linux/mutex.h>
25 #include <linux/spinlock.h>
26 #include <linux/writeback.h> /* for inode_lock */
28 #include <asm/atomic.h>
30 #include <linux/fsnotify_backend.h>
33 void fsnotify_clear_marks_by_mount(struct vfsmount
*mnt
)
35 struct fsnotify_mark
*mark
, *lmark
;
36 struct hlist_node
*pos
, *n
;
39 spin_lock(&mnt
->mnt_root
->d_lock
);
40 hlist_for_each_entry_safe(mark
, pos
, n
, &mnt
->mnt_fsnotify_marks
, m
.m_list
) {
41 list_add(&mark
->m
.free_m_list
, &free_list
);
42 hlist_del_init_rcu(&mark
->m
.m_list
);
43 fsnotify_get_mark(mark
);
45 spin_unlock(&mnt
->mnt_root
->d_lock
);
47 list_for_each_entry_safe(mark
, lmark
, &free_list
, m
.free_m_list
) {
48 fsnotify_destroy_mark(mark
);
49 fsnotify_put_mark(mark
);
53 void fsnotify_clear_vfsmount_marks_by_group(struct fsnotify_group
*group
)
55 fsnotify_clear_marks_by_group_flags(group
, FSNOTIFY_MARK_FLAG_VFSMOUNT
);
59 * Recalculate the mask of events relevant to a given vfsmount locked.
61 static void fsnotify_recalc_vfsmount_mask_locked(struct vfsmount
*mnt
)
63 struct fsnotify_mark
*mark
;
64 struct hlist_node
*pos
;
67 assert_spin_locked(&mnt
->mnt_root
->d_lock
);
69 hlist_for_each_entry(mark
, pos
, &mnt
->mnt_fsnotify_marks
, m
.m_list
)
70 new_mask
|= mark
->mask
;
71 mnt
->mnt_fsnotify_mask
= new_mask
;
75 * Recalculate the mnt->mnt_fsnotify_mask, or the mask of all FS_* event types
76 * any notifier is interested in hearing for this mount point
78 void fsnotify_recalc_vfsmount_mask(struct vfsmount
*mnt
)
80 spin_lock(&mnt
->mnt_root
->d_lock
);
81 fsnotify_recalc_vfsmount_mask_locked(mnt
);
82 spin_unlock(&mnt
->mnt_root
->d_lock
);
85 void fsnotify_destroy_vfsmount_mark(struct fsnotify_mark
*mark
)
87 struct vfsmount
*mnt
= mark
->m
.mnt
;
89 assert_spin_locked(&mark
->lock
);
90 assert_spin_locked(&mark
->group
->mark_lock
);
92 spin_lock(&mnt
->mnt_root
->d_lock
);
94 hlist_del_init_rcu(&mark
->m
.m_list
);
97 fsnotify_recalc_vfsmount_mask_locked(mnt
);
99 spin_unlock(&mnt
->mnt_root
->d_lock
);
102 static struct fsnotify_mark
*fsnotify_find_vfsmount_mark_locked(struct fsnotify_group
*group
,
103 struct vfsmount
*mnt
)
105 struct fsnotify_mark
*mark
;
106 struct hlist_node
*pos
;
108 assert_spin_locked(&mnt
->mnt_root
->d_lock
);
110 hlist_for_each_entry(mark
, pos
, &mnt
->mnt_fsnotify_marks
, m
.m_list
) {
111 if (mark
->group
== group
) {
112 fsnotify_get_mark(mark
);
120 * given a group and vfsmount, find the mark associated with that combination.
121 * if found take a reference to that mark and return it, else return NULL
123 struct fsnotify_mark
*fsnotify_find_vfsmount_mark(struct fsnotify_group
*group
,
124 struct vfsmount
*mnt
)
126 struct fsnotify_mark
*mark
;
128 spin_lock(&mnt
->mnt_root
->d_lock
);
129 mark
= fsnotify_find_vfsmount_mark_locked(group
, mnt
);
130 spin_unlock(&mnt
->mnt_root
->d_lock
);
136 * Attach an initialized mark to a given group and vfsmount.
137 * These marks may be used for the fsnotify backend to determine which
138 * event types should be delivered to which groups.
140 int fsnotify_add_vfsmount_mark(struct fsnotify_mark
*mark
,
141 struct fsnotify_group
*group
, struct vfsmount
*mnt
,
144 struct fsnotify_mark
*lmark
;
145 struct hlist_node
*node
, *last
= NULL
;
148 mark
->flags
|= FSNOTIFY_MARK_FLAG_VFSMOUNT
;
150 assert_spin_locked(&mark
->lock
);
151 assert_spin_locked(&group
->mark_lock
);
153 spin_lock(&mnt
->mnt_root
->d_lock
);
157 /* is mark the first mark? */
158 if (hlist_empty(&mnt
->mnt_fsnotify_marks
)) {
159 hlist_add_head_rcu(&mark
->m
.m_list
, &mnt
->mnt_fsnotify_marks
);
163 /* should mark be in the middle of the current list? */
164 hlist_for_each_entry(lmark
, node
, &mnt
->mnt_fsnotify_marks
, m
.m_list
) {
167 if ((lmark
->group
== group
) && !allow_dups
) {
172 if (mark
->group
->priority
< lmark
->group
->priority
)
175 if ((mark
->group
->priority
== lmark
->group
->priority
) &&
176 (mark
->group
< lmark
->group
))
179 hlist_add_before_rcu(&mark
->m
.m_list
, &lmark
->m
.m_list
);
183 BUG_ON(last
== NULL
);
184 /* mark should be the last entry. last is the current last entry */
185 hlist_add_after_rcu(last
, &mark
->m
.m_list
);
187 fsnotify_recalc_vfsmount_mask_locked(mnt
);
188 spin_unlock(&mnt
->mnt_root
->d_lock
);