2 Unix SMB/CIFS implementation.
4 Copyright (C) Andrew Tridgell 2006
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>.
21 notify implementation using inotify
28 #ifdef HAVE_ASM_TYPES_H
29 #include <asm/types.h>
32 #include <linux/inotify.h>
33 #include <asm/unistd.h>
35 #ifndef HAVE_INOTIFY_INIT
37 glibc doesn't define these functions yet (as of March 2006)
39 static int inotify_init(void)
41 return syscall(__NR_inotify_init);
44 static int inotify_add_watch(int fd, const char *path, __u32 mask)
46 return syscall(__NR_inotify_add_watch, fd, path, mask);
49 static int inotify_rm_watch(int fd, int wd)
51 return syscall(__NR_inotify_rm_watch, fd, wd);
56 /* older glibc headers don't have these defines either */
58 #define IN_ONLYDIR 0x01000000
61 #define IN_MASK_ADD 0x20000000
64 struct inotify_private {
65 struct sys_notify_context *ctx;
67 struct inotify_watch_context *watches;
70 struct inotify_watch_context {
71 struct inotify_watch_context *next, *prev;
72 struct inotify_private *in;
74 void (*callback)(struct sys_notify_context *ctx,
76 struct notify_event *ev);
78 uint32_t mask; /* the inotify mask */
79 uint32_t filter; /* the windows completion filter */
85 destroy the inotify private context
87 static int inotify_destructor(struct inotify_private *in)
95 see if a particular event from inotify really does match a requested
98 static bool filter_match(struct inotify_watch_context *w,
99 struct inotify_event *e)
101 DEBUG(10, ("filter_match: e->mask=%x, w->mask=%x, w->filter=%x\n",
102 e->mask, w->mask, w->filter));
104 if ((e->mask & w->mask) == 0) {
105 /* this happens because inotify_add_watch() coalesces watches on the same
106 path, oring their masks together */
110 /* SMB separates the filters for files and directories */
111 if (e->mask & IN_ISDIR) {
112 if ((w->filter & FILE_NOTIFY_CHANGE_DIR_NAME) == 0) {
116 if ((e->mask & IN_ATTRIB) &&
117 (w->filter & (FILE_NOTIFY_CHANGE_ATTRIBUTES|
118 FILE_NOTIFY_CHANGE_LAST_WRITE|
119 FILE_NOTIFY_CHANGE_LAST_ACCESS|
120 FILE_NOTIFY_CHANGE_EA|
121 FILE_NOTIFY_CHANGE_SECURITY))) {
124 if ((e->mask & IN_MODIFY) &&
125 (w->filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)) {
128 if ((w->filter & FILE_NOTIFY_CHANGE_FILE_NAME) == 0) {
139 dispatch one inotify event
141 the cookies are used to correctly handle renames
143 static void inotify_dispatch(struct inotify_private *in,
144 struct inotify_event *e,
145 uint32_t prev_cookie,
146 struct inotify_event *e2)
148 struct inotify_watch_context *w, *next;
149 struct notify_event ne;
151 DEBUG(10, ("inotify_dispatch called with mask=%x, name=[%s]\n",
152 e->mask, e->len ? e->name : ""));
154 /* ignore extraneous events, such as unmount and IN_IGNORED events */
155 if ((e->mask & (IN_ATTRIB|IN_MODIFY|IN_CREATE|IN_DELETE|
156 IN_MOVED_FROM|IN_MOVED_TO)) == 0) {
160 /* map the inotify mask to a action. This gets complicated for
162 if (e->mask & IN_CREATE) {
163 ne.action = NOTIFY_ACTION_ADDED;
164 } else if (e->mask & IN_DELETE) {
165 ne.action = NOTIFY_ACTION_REMOVED;
166 } else if (e->mask & IN_MOVED_FROM) {
167 if (e2 != NULL && e2->cookie == e->cookie) {
168 ne.action = NOTIFY_ACTION_OLD_NAME;
170 ne.action = NOTIFY_ACTION_REMOVED;
172 } else if (e->mask & IN_MOVED_TO) {
173 if (e->cookie == prev_cookie) {
174 ne.action = NOTIFY_ACTION_NEW_NAME;
176 ne.action = NOTIFY_ACTION_ADDED;
179 ne.action = NOTIFY_ACTION_MODIFIED;
183 DEBUG(10, ("inotify_dispatch: ne.action = %d, ne.path = %s\n",
184 ne.action, ne.path));
186 /* find any watches that have this watch descriptor */
187 for (w=in->watches;w;w=next) {
189 if (w->wd == e->wd && filter_match(w, e)) {
190 w->callback(in->ctx, w->private_data, &ne);
194 /* SMB expects a file rename to generate three events, two for
195 the rename and the other for a modify of the
196 destination. Strange! */
197 if (ne.action != NOTIFY_ACTION_NEW_NAME ||
198 (e->mask & IN_ISDIR) != 0) {
202 ne.action = NOTIFY_ACTION_MODIFIED;
205 for (w=in->watches;w;w=next) {
207 if (w->wd == e->wd && filter_match(w, e) &&
208 !(w->filter & FILE_NOTIFY_CHANGE_CREATION)) {
209 w->callback(in->ctx, w->private_data, &ne);
215 called when the kernel has some events for us
217 static void inotify_handler(struct event_context *ev, struct fd_event *fde,
218 uint16_t flags, void *private_data)
220 struct inotify_private *in = talloc_get_type(private_data,
221 struct inotify_private);
223 struct inotify_event *e0, *e;
224 uint32_t prev_cookie=0;
227 we must use FIONREAD as we cannot predict the length of the
228 filenames, and thus can't know how much to allocate
231 if (ioctl(in->fd, FIONREAD, &bufsize) != 0 ||
233 DEBUG(0,("No data on inotify fd?!\n"));
237 e0 = e = (struct inotify_event *)TALLOC_SIZE(in, bufsize);
238 if (e == NULL) return;
240 if (read(in->fd, e0, bufsize) != bufsize) {
241 DEBUG(0,("Failed to read all inotify data\n"));
246 /* we can get more than one event in the buffer */
247 while (bufsize >= sizeof(*e)) {
248 struct inotify_event *e2 = NULL;
249 bufsize -= e->len + sizeof(*e);
250 if (bufsize >= sizeof(*e)) {
251 e2 = (struct inotify_event *)(e->len + sizeof(*e) + (char *)e);
253 inotify_dispatch(in, e, prev_cookie, e2);
254 prev_cookie = e->cookie;
262 setup the inotify handle - called the first time a watch is added on
265 static NTSTATUS inotify_setup(struct sys_notify_context *ctx)
267 struct inotify_private *in;
269 if (!lp_parm_bool(-1, "notify", "inotify", True)) {
270 return NT_STATUS_INVALID_SYSTEM_SERVICE;
273 in = talloc(ctx, struct inotify_private);
274 NT_STATUS_HAVE_NO_MEMORY(in);
275 in->fd = inotify_init();
277 DEBUG(0,("Failed to init inotify - %s\n", strerror(errno)));
279 return map_nt_error_from_unix(errno);
284 ctx->private_data = in;
285 talloc_set_destructor(in, inotify_destructor);
287 /* add a event waiting for the inotify fd to be readable */
288 event_add_fd(ctx->ev, in, in->fd, EVENT_FD_READ, inotify_handler, in);
295 map from a change notify mask to a inotify mask. Remove any bits
298 static const struct {
299 uint32_t notify_mask;
300 uint32_t inotify_mask;
301 } inotify_mapping[] = {
302 {FILE_NOTIFY_CHANGE_FILE_NAME, IN_CREATE|IN_DELETE|IN_MOVED_FROM|IN_MOVED_TO},
303 {FILE_NOTIFY_CHANGE_DIR_NAME, IN_CREATE|IN_DELETE|IN_MOVED_FROM|IN_MOVED_TO},
304 {FILE_NOTIFY_CHANGE_ATTRIBUTES, IN_ATTRIB|IN_MOVED_TO|IN_MOVED_FROM|IN_MODIFY},
305 {FILE_NOTIFY_CHANGE_LAST_WRITE, IN_ATTRIB},
306 {FILE_NOTIFY_CHANGE_LAST_ACCESS, IN_ATTRIB},
307 {FILE_NOTIFY_CHANGE_EA, IN_ATTRIB},
308 {FILE_NOTIFY_CHANGE_SECURITY, IN_ATTRIB}
311 static uint32_t inotify_map(struct notify_entry *e)
315 for (i=0;i<ARRAY_SIZE(inotify_mapping);i++) {
316 if (inotify_mapping[i].notify_mask & e->filter) {
317 out |= inotify_mapping[i].inotify_mask;
318 e->filter &= ~inotify_mapping[i].notify_mask;
327 static int watch_destructor(struct inotify_watch_context *w)
329 struct inotify_private *in = w->in;
331 DLIST_REMOVE(w->in->watches, w);
333 /* only rm the watch if its the last one with this wd */
334 for (w=in->watches;w;w=w->next) {
335 if (w->wd == wd) break;
338 DEBUG(10, ("Deleting inotify watch %d\n", wd));
339 if (inotify_rm_watch(in->fd, wd) == -1) {
340 DEBUG(1, ("inotify_rm_watch returned %s\n",
350 add a watch. The watch is removed when the caller calls
351 talloc_free() on *handle
353 NTSTATUS inotify_watch(struct sys_notify_context *ctx,
354 struct notify_entry *e,
355 void (*callback)(struct sys_notify_context *ctx,
357 struct notify_event *ev),
361 struct inotify_private *in;
364 struct inotify_watch_context *w;
365 uint32_t filter = e->filter;
366 void **handle = (void **)handle_p;
368 /* maybe setup the inotify fd */
369 if (ctx->private_data == NULL) {
371 status = inotify_setup(ctx);
372 NT_STATUS_NOT_OK_RETURN(status);
375 in = talloc_get_type(ctx->private_data, struct inotify_private);
377 mask = inotify_map(e);
379 /* this filter can't be handled by inotify */
380 return NT_STATUS_INVALID_PARAMETER;
383 /* using IN_MASK_ADD allows us to cope with inotify() returning the same
384 watch descriptor for muliple watches on the same path */
385 mask |= (IN_MASK_ADD | IN_ONLYDIR);
387 /* get a new watch descriptor for this path */
388 wd = inotify_add_watch(in->fd, e->path, mask);
391 DEBUG(1, ("inotify_add_watch returned %s\n", strerror(errno)));
392 return map_nt_error_from_unix(errno);
395 DEBUG(10, ("inotify_add_watch for %s mask %x returned wd %d\n",
398 w = talloc(in, struct inotify_watch_context);
400 inotify_rm_watch(in->fd, wd);
402 return NT_STATUS_NO_MEMORY;
407 w->callback = callback;
408 w->private_data = private_data;
411 w->path = talloc_strdup(w, e->path);
412 if (w->path == NULL) {
413 inotify_rm_watch(in->fd, wd);
415 return NT_STATUS_NO_MEMORY;
420 DLIST_ADD(in->watches, w);
422 /* the caller frees the handle to stop watching */
423 talloc_set_destructor(w, watch_destructor);