ocfs2: Remove ENTRY from masklog.
[linux-2.6/libata-dev.git] / fs / notify / vfsmount_mark.c
blob85eebff6d0d7de00928c5281e7418688c2265907
1 /*
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)
7 * any later version.
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.
19 #include <linux/fs.h>
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>
31 #include "fsnotify.h"
33 void fsnotify_clear_marks_by_mount(struct vfsmount *mnt)
35 struct fsnotify_mark *mark, *lmark;
36 struct hlist_node *pos, *n;
37 LIST_HEAD(free_list);
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;
65 __u32 new_mask = 0;
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);
95 mark->m.mnt = NULL;
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);
113 return mark;
116 return NULL;
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);
132 return mark;
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,
142 int allow_dups)
144 struct fsnotify_mark *lmark;
145 struct hlist_node *node, *last = NULL;
146 int ret = 0;
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);
155 mark->m.mnt = mnt;
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);
160 goto out;
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) {
165 last = node;
167 if ((lmark->group == group) && !allow_dups) {
168 ret = -EEXIST;
169 goto out;
172 if (mark->group->priority < lmark->group->priority)
173 continue;
175 if ((mark->group->priority == lmark->group->priority) &&
176 (mark->group < lmark->group))
177 continue;
179 hlist_add_before_rcu(&mark->m.m_list, &lmark->m.m_list);
180 goto out;
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);
186 out:
187 fsnotify_recalc_vfsmount_mask_locked(mnt);
188 spin_unlock(&mnt->mnt_root->d_lock);
190 return ret;