1 | /* -*- Mode: C; indent-tabs-mode: t; c-basic-offset: 2; tab-width: 8 -*- */ |
2 | |
3 | /* inotify-helper.c - GVFS Monitor based on inotify. |
4 | |
5 | Copyright (C) 2007 John McCutchan |
6 | |
7 | This library is free software; you can redistribute it and/or |
8 | modify it under the terms of the GNU Lesser General Public |
9 | License as published by the Free Software Foundation; either |
10 | version 2.1 of the License, or (at your option) any later version. |
11 | |
12 | This library is distributed in the hope that it will be useful, |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
15 | Lesser General Public License for more details. |
16 | |
17 | You should have received a copy of the GNU Lesser General Public License |
18 | along with this library; if not, see <http://www.gnu.org/licenses/>. |
19 | |
20 | Authors: |
21 | John McCutchan <john@johnmccutchan.com> |
22 | */ |
23 | |
24 | #include "config.h" |
25 | #include <errno.h> |
26 | #include <time.h> |
27 | #include <string.h> |
28 | #include <sys/ioctl.h> |
29 | #include <sys/stat.h> |
30 | /* Just include the local header to stop all the pain */ |
31 | #include <sys/inotify.h> |
32 | #include <gio/glocalfilemonitor.h> |
33 | #include <gio/gfile.h> |
34 | #include "inotify-helper.h" |
35 | #include "inotify-missing.h" |
36 | #include "inotify-path.h" |
37 | |
38 | static gboolean ih_debug_enabled = FALSE; |
39 | #define IH_W if (ih_debug_enabled) g_warning |
40 | |
41 | static gboolean ih_event_callback (ik_event_t *event, |
42 | inotify_sub *sub, |
43 | gboolean file_event); |
44 | static void ih_not_missing_callback (inotify_sub *sub); |
45 | |
46 | /* We share this lock with inotify-kernel.c and inotify-missing.c |
47 | * |
48 | * inotify-kernel.c takes the lock when it reads events from |
49 | * the kernel and when it processes those events |
50 | * |
51 | * inotify-missing.c takes the lock when it is scanning the missing |
52 | * list. |
53 | * |
54 | * We take the lock in all public functions |
55 | */ |
56 | G_LOCK_DEFINE (inotify_lock); |
57 | |
58 | static GFileMonitorEvent ih_mask_to_EventFlags (guint32 mask); |
59 | |
60 | /** |
61 | * _ih_startup: |
62 | * |
63 | * Initializes the inotify backend. This must be called before |
64 | * any other functions in this module. |
65 | * |
66 | * Returns: #TRUE if initialization succeeded, #FALSE otherwise |
67 | */ |
68 | gboolean |
69 | _ih_startup (void) |
70 | { |
71 | static gboolean initialized = FALSE; |
72 | static gboolean result = FALSE; |
73 | |
74 | G_LOCK (inotify_lock); |
75 | |
76 | if (initialized == TRUE) |
77 | { |
78 | G_UNLOCK (inotify_lock); |
79 | return result; |
80 | } |
81 | |
82 | result = _ip_startup (event_cb: ih_event_callback); |
83 | if (!result) |
84 | { |
85 | G_UNLOCK (inotify_lock); |
86 | return FALSE; |
87 | } |
88 | _im_startup (missing_cb: ih_not_missing_callback); |
89 | |
90 | IH_W ("started gvfs inotify backend\n" ); |
91 | |
92 | initialized = TRUE; |
93 | |
94 | G_UNLOCK (inotify_lock); |
95 | |
96 | return TRUE; |
97 | } |
98 | |
99 | /* |
100 | * Adds a subscription to be monitored. |
101 | */ |
102 | gboolean |
103 | _ih_sub_add (inotify_sub *sub) |
104 | { |
105 | G_LOCK (inotify_lock); |
106 | |
107 | if (!_ip_start_watching (sub)) |
108 | _im_add (sub); |
109 | |
110 | G_UNLOCK (inotify_lock); |
111 | |
112 | return TRUE; |
113 | } |
114 | |
115 | /* |
116 | * Cancels a subscription which was being monitored. |
117 | */ |
118 | gboolean |
119 | _ih_sub_cancel (inotify_sub *sub) |
120 | { |
121 | G_LOCK (inotify_lock); |
122 | |
123 | if (!sub->cancelled) |
124 | { |
125 | IH_W ("cancelling %s\n" , sub->dirname); |
126 | sub->cancelled = TRUE; |
127 | _im_rm (sub); |
128 | _ip_stop_watching (sub); |
129 | } |
130 | |
131 | G_UNLOCK (inotify_lock); |
132 | |
133 | return TRUE; |
134 | } |
135 | |
136 | static char * |
137 | _ih_fullpath_from_event (ik_event_t *event, |
138 | const char *dirname, |
139 | const char *filename) |
140 | { |
141 | char *fullpath; |
142 | |
143 | if (filename) |
144 | fullpath = g_strdup_printf (format: "%s/%s" , dirname, filename); |
145 | else if (event->name) |
146 | fullpath = g_strdup_printf (format: "%s/%s" , dirname, event->name); |
147 | else |
148 | fullpath = g_strdup_printf (format: "%s/" , dirname); |
149 | |
150 | return fullpath; |
151 | } |
152 | |
153 | static gboolean |
154 | ih_event_callback (ik_event_t *event, |
155 | inotify_sub *sub, |
156 | gboolean file_event) |
157 | { |
158 | gboolean interesting; |
159 | GFileMonitorEvent event_flags; |
160 | |
161 | event_flags = ih_mask_to_EventFlags (mask: event->mask); |
162 | |
163 | if (event->mask & IN_MOVE) |
164 | { |
165 | /* We either have a rename (in the same directory) or a move |
166 | * (between different directories). |
167 | */ |
168 | if (event->pair && event->pair->wd == event->wd) |
169 | { |
170 | /* this is a rename */ |
171 | interesting = g_file_monitor_source_handle_event (fms: sub->user_data, event_type: G_FILE_MONITOR_EVENT_RENAMED, |
172 | child: event->name, rename_to: event->pair->name, NULL, event_time: event->timestamp); |
173 | } |
174 | else |
175 | { |
176 | GFile *other; |
177 | |
178 | if (event->pair) |
179 | { |
180 | const char *parent_dir; |
181 | gchar *fullpath; |
182 | |
183 | parent_dir = _ip_get_path_for_wd (wd: event->pair->wd); |
184 | fullpath = _ih_fullpath_from_event (event: event->pair, dirname: parent_dir, NULL); |
185 | other = g_file_new_for_path (path: fullpath); |
186 | g_free (mem: fullpath); |
187 | } |
188 | else |
189 | other = NULL; |
190 | |
191 | /* This is either an incoming or outgoing move. Since we checked the |
192 | * event->mask above, it should have converted to a #GFileMonitorEvent |
193 | * properly. If not, the assumption we have made about event->mask |
194 | * only ever having a single bit set (apart from IN_ISDIR) is false. |
195 | * The kernel documentation is lacking here. */ |
196 | g_assert ((int) event_flags != -1); |
197 | interesting = g_file_monitor_source_handle_event (fms: sub->user_data, event_type: event_flags, |
198 | child: event->name, NULL, other, event_time: event->timestamp); |
199 | |
200 | if (other) |
201 | g_object_unref (object: other); |
202 | } |
203 | } |
204 | else if ((int) event_flags != -1) |
205 | /* unpaired event -- no 'other' field */ |
206 | interesting = g_file_monitor_source_handle_event (fms: sub->user_data, event_type: event_flags, |
207 | child: event->name, NULL, NULL, event_time: event->timestamp); |
208 | else |
209 | interesting = FALSE; |
210 | |
211 | if (event->mask & IN_CREATE) |
212 | { |
213 | const gchar *parent_dir; |
214 | gchar *fullname; |
215 | struct stat buf; |
216 | gint s; |
217 | |
218 | /* The kernel reports IN_CREATE for two types of events: |
219 | * |
220 | * - creat(), in which case IN_CLOSE_WRITE will come soon; or |
221 | * - link(), mkdir(), mknod(), etc., in which case it won't |
222 | * |
223 | * We can attempt to detect the second case and send the |
224 | * CHANGES_DONE immediately so that the user isn't left waiting. |
225 | * |
226 | * The detection for link() is not 100% reliable since the link |
227 | * count could be 1 if the original link was deleted or if |
228 | * O_TMPFILE was being used, but in that case the virtual |
229 | * CHANGES_DONE will be emitted to close the loop. |
230 | */ |
231 | |
232 | parent_dir = _ip_get_path_for_wd (wd: event->wd); |
233 | fullname = _ih_fullpath_from_event (event, dirname: parent_dir, NULL); |
234 | s = stat (file: fullname, buf: &buf); |
235 | g_free (mem: fullname); |
236 | |
237 | /* if it doesn't look like the result of creat()... */ |
238 | if (s != 0 || !S_ISREG (buf.st_mode) || buf.st_nlink != 1) |
239 | g_file_monitor_source_handle_event (fms: sub->user_data, event_type: G_FILE_MONITOR_EVENT_CHANGES_DONE_HINT, |
240 | child: event->name, NULL, NULL, event_time: event->timestamp); |
241 | } |
242 | |
243 | return interesting; |
244 | } |
245 | |
246 | static void |
247 | ih_not_missing_callback (inotify_sub *sub) |
248 | { |
249 | gint now = g_get_monotonic_time (); |
250 | |
251 | g_file_monitor_source_handle_event (fms: sub->user_data, event_type: G_FILE_MONITOR_EVENT_CREATED, |
252 | child: sub->filename, NULL, NULL, event_time: now); |
253 | g_file_monitor_source_handle_event (fms: sub->user_data, event_type: G_FILE_MONITOR_EVENT_CHANGES_DONE_HINT, |
254 | child: sub->filename, NULL, NULL, event_time: now); |
255 | } |
256 | |
257 | /* Transforms a inotify event to a GVFS event. */ |
258 | static GFileMonitorEvent |
259 | ih_mask_to_EventFlags (guint32 mask) |
260 | { |
261 | mask &= ~IN_ISDIR; |
262 | switch (mask) |
263 | { |
264 | case IN_MODIFY: |
265 | return G_FILE_MONITOR_EVENT_CHANGED; |
266 | case IN_CLOSE_WRITE: |
267 | return G_FILE_MONITOR_EVENT_CHANGES_DONE_HINT; |
268 | case IN_ATTRIB: |
269 | return G_FILE_MONITOR_EVENT_ATTRIBUTE_CHANGED; |
270 | case IN_MOVE_SELF: |
271 | case IN_DELETE: |
272 | case IN_DELETE_SELF: |
273 | return G_FILE_MONITOR_EVENT_DELETED; |
274 | case IN_CREATE: |
275 | return G_FILE_MONITOR_EVENT_CREATED; |
276 | case IN_MOVED_FROM: |
277 | return G_FILE_MONITOR_EVENT_MOVED_OUT; |
278 | case IN_MOVED_TO: |
279 | return G_FILE_MONITOR_EVENT_MOVED_IN; |
280 | case IN_UNMOUNT: |
281 | return G_FILE_MONITOR_EVENT_UNMOUNTED; |
282 | case IN_Q_OVERFLOW: |
283 | case IN_OPEN: |
284 | case IN_CLOSE_NOWRITE: |
285 | case IN_ACCESS: |
286 | case IN_IGNORED: |
287 | default: |
288 | return -1; |
289 | } |
290 | } |
291 | |