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 @@ | |||
1 | /* | ||
2 | * fs/inotify_user.c - inotify support for userspace | ||
3 | * | ||
4 | * Authors: | ||
5 | * John McCutchan <ttb@tentacle.dhs.org> | ||
6 | * Robert Love <rml@novell.com> | ||
7 | * | ||
8 | * Copyright (C) 2005 John McCutchan | ||
9 | * Copyright 2006 Hewlett-Packard Development Company, L.P. | ||
10 | * | ||
11 | * Copyright (C) 2009 Eric Paris <Red Hat Inc> | ||
12 | * inotify was largely rewriten to make use of the fsnotify infrastructure | ||
13 | * | ||
14 | * This program is free software; you can redistribute it and/or modify it | ||
15 | * under the terms of the GNU General Public License as published by the | ||
16 | * Free Software Foundation; either version 2, or (at your option) any | ||
17 | * later version. | ||
18 | * | ||
19 | * This program is distributed in the hope that it will be useful, but | ||
20 | * WITHOUT ANY WARRANTY; without even the implied warranty of | ||
21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | ||
22 | * General Public License for more details. | ||
23 | */ | ||
24 | |||
25 | #include <linux/fs.h> /* struct inode */ | ||
26 | #include <linux/fsnotify_backend.h> | ||
27 | #include <linux/inotify.h> | ||
28 | #include <linux/path.h> /* struct path */ | ||
29 | #include <linux/slab.h> /* kmem_* */ | ||
30 | #include <linux/types.h> | ||
31 | |||
32 | #include "inotify.h" | ||
33 | |||
34 | static int inotify_handle_event(struct fsnotify_group *group, struct fsnotify_event *event) | ||
35 | { | ||
36 | struct fsnotify_mark_entry *entry; | ||
37 | struct inotify_inode_mark_entry *ientry; | ||
38 | struct inode *to_tell; | ||
39 | struct inotify_event_private_data *event_priv; | ||
40 | struct fsnotify_event_private_data *fsn_event_priv; | ||
41 | int wd, ret; | ||
42 | |||
43 | to_tell = event->to_tell; | ||
44 | |||
45 | spin_lock(&to_tell->i_lock); | ||
46 | entry = fsnotify_find_mark_entry(group, to_tell); | ||
47 | spin_unlock(&to_tell->i_lock); | ||
48 | /* race with watch removal? We already passes should_send */ | ||
49 | if (unlikely(!entry)) | ||
50 | return 0; | ||
51 | ientry = container_of(entry, struct inotify_inode_mark_entry, | ||
52 | fsn_entry); | ||
53 | wd = ientry->wd; | ||
54 | |||
55 | event_priv = kmem_cache_alloc(event_priv_cachep, GFP_KERNEL); | ||
56 | if (unlikely(!event_priv)) | ||
57 | return -ENOMEM; | ||
58 | |||
59 | fsn_event_priv = &event_priv->fsnotify_event_priv_data; | ||
60 | |||
61 | fsn_event_priv->group = group; | ||
62 | event_priv->wd = wd; | ||
63 | |||
64 | ret = fsnotify_add_notify_event(group, event, fsn_event_priv); | ||
65 | /* EEXIST is not an error */ | ||
66 | if (ret == -EEXIST) | ||
67 | ret = 0; | ||
68 | |||
69 | /* did event_priv get attached? */ | ||
70 | if (list_empty(&fsn_event_priv->event_list)) | ||
71 | inotify_free_event_priv(fsn_event_priv); | ||
72 | |||
73 | /* | ||
74 | * If we hold the entry until after the event is on the queue | ||
75 | * IN_IGNORED won't be able to pass this event in the queue | ||
76 | */ | ||
77 | fsnotify_put_mark(entry); | ||
78 | |||
79 | return ret; | ||
80 | } | ||
81 | |||
82 | static void inotify_freeing_mark(struct fsnotify_mark_entry *entry, struct fsnotify_group *group) | ||
83 | { | ||
84 | inotify_destroy_mark_entry(entry, group); | ||
85 | } | ||
86 | |||
87 | static bool inotify_should_send_event(struct fsnotify_group *group, struct inode *inode, __u32 mask) | ||
88 | { | ||
89 | struct fsnotify_mark_entry *entry; | ||
90 | bool send; | ||
91 | |||
92 | spin_lock(&inode->i_lock); | ||
93 | entry = fsnotify_find_mark_entry(group, inode); | ||
94 | spin_unlock(&inode->i_lock); | ||
95 | if (!entry) | ||
96 | return false; | ||
97 | |||
98 | mask = (mask & ~FS_EVENT_ON_CHILD); | ||
99 | send = (entry->mask & mask); | ||
100 | |||
101 | /* find took a reference */ | ||
102 | fsnotify_put_mark(entry); | ||
103 | |||
104 | return send; | ||
105 | } | ||
106 | |||
107 | static int idr_callback(int id, void *p, void *data) | ||
108 | { | ||
109 | BUG(); | ||
110 | return 0; | ||
111 | } | ||
112 | |||
113 | static void inotify_free_group_priv(struct fsnotify_group *group) | ||
114 | { | ||
115 | /* ideally the idr is empty and we won't hit the BUG in teh callback */ | ||
116 | idr_for_each(&group->inotify_data.idr, idr_callback, NULL); | ||
117 | idr_remove_all(&group->inotify_data.idr); | ||
118 | idr_destroy(&group->inotify_data.idr); | ||
119 | } | ||
120 | |||
121 | void inotify_free_event_priv(struct fsnotify_event_private_data *fsn_event_priv) | ||
122 | { | ||
123 | struct inotify_event_private_data *event_priv; | ||
124 | |||
125 | |||
126 | event_priv = container_of(fsn_event_priv, struct inotify_event_private_data, | ||
127 | fsnotify_event_priv_data); | ||
128 | |||
129 | kmem_cache_free(event_priv_cachep, event_priv); | ||
130 | } | ||
131 | |||
132 | const struct fsnotify_ops inotify_fsnotify_ops = { | ||
133 | .handle_event = inotify_handle_event, | ||
134 | .should_send_event = inotify_should_send_event, | ||
135 | .free_group_priv = inotify_free_group_priv, | ||
136 | .free_event_priv = inotify_free_event_priv, | ||
137 | .freeing_mark = inotify_freeing_mark, | ||
138 | }; | ||