fsmonitor--daemon.c · leroysheep/Socializer

test

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1	#define USE_THE_REPOSITORY_VARIABLE
2	#define DISABLE_SIGN_COMPARE_WARNINGS
3
4	#include "builtin.h"
5	#include "abspath.h"
6	#include "config.h"
7	#include "dir.h"
8	#include "environment.h"
9	#include "gettext.h"
10	#include "parse-options.h"
11	#include "fsmonitor-ll.h"
12	#include "fsmonitor-ipc.h"
13	#include "fsmonitor-settings.h"
14	#include "compat/fsmonitor/fsm-health.h"
15	#include "compat/fsmonitor/fsm-listen.h"
16	#include "fsmonitor--daemon.h"
17
18	#include "simple-ipc.h"
19	#include "strmap.h"
20	#include "run-command.h"
21	#include "trace.h"
22	#include "trace2.h"
23
24	static const char * const builtin_fsmonitor__daemon_usage[] = {
25	N_("git fsmonitor--daemon start [<options>]"),
26	N_("git fsmonitor--daemon run [<options>]"),
27	"git fsmonitor--daemon stop",
28	"git fsmonitor--daemon status",
29	NULL
30	};
31
32	#ifdef HAVE_FSMONITOR_DAEMON_BACKEND
33	/*
34	* Global state loaded from config.
35	*/
36	#define FSMONITOR__IPC_THREADS "fsmonitor.ipcthreads"
37	static int fsmonitor__ipc_threads = 8;
38
39	#define FSMONITOR__START_TIMEOUT "fsmonitor.starttimeout"
40	static int fsmonitor__start_timeout_sec = 60;
41
42	#define FSMONITOR__ANNOUNCE_STARTUP "fsmonitor.announcestartup"
43	static int fsmonitor__announce_startup = 0;
44
45	static int fsmonitor_config(const char var, const char value,
46	const struct config_context ctx, void cb)
47	{
48	if (!strcmp(var, FSMONITOR__IPC_THREADS)) {
49	int i = git_config_int(var, value, ctx->kvi);
50	if (i < 1)
51	return error(_("value of '%s' out of range: %d"),
52	FSMONITOR__IPC_THREADS, i);
53	fsmonitor__ipc_threads = i;
54	return 0;
55	}
56
57	if (!strcmp(var, FSMONITOR__START_TIMEOUT)) {
58	int i = git_config_int(var, value, ctx->kvi);
59	if (i < 0)
60	return error(_("value of '%s' out of range: %d"),
61	FSMONITOR__START_TIMEOUT, i);
62	fsmonitor__start_timeout_sec = i;
63	return 0;
64	}
65
66	if (!strcmp(var, FSMONITOR__ANNOUNCE_STARTUP)) {
67	int is_bool;
68	int i = git_config_bool_or_int(var, value, ctx->kvi, &is_bool);
69	if (i < 0)
70	return error(_("value of '%s' not bool or int: %d"),
71	var, i);
72	fsmonitor__announce_startup = i;
73	return 0;
74	}
75
76	return git_default_config(var, value, ctx, cb);
77	}
78
79	/*
80	* Acting as a CLIENT.
81	*
82	* Send a "quit" command to the `git-fsmonitor--daemon` (if running)
83	* and wait for it to shutdown.
84	*/
85	static int do_as_client__send_stop(void)
86	{
87	struct strbuf answer = STRBUF_INIT;
88	int ret;
89	int max_wait_ms = 30000;
90	int elapsed_ms = 0;
91
92	ret = fsmonitor_ipc__send_command("quit", &answer);
93
94	/* The quit command does not return any response data. */
95	strbuf_release(&answer);
96
97	if (ret)
98	return ret;
99
100	trace2_region_enter("fsm_client", "polling-for-daemon-exit", NULL);
101	while (fsmonitor_ipc__get_state() == IPC_STATE__LISTENING) {
102	if (elapsed_ms >= max_wait_ms) {
103	trace2_region_leave("fsm_client",
104	"polling-for-daemon-exit", NULL);
105	return error(_("daemon did not stop within %d seconds"),
106	max_wait_ms / 1000);
107	}
108	sleep_millisec(50);
109	elapsed_ms += 50;
110	}
111	trace2_region_leave("fsm_client", "polling-for-daemon-exit", NULL);
112
113	return 0;
114	}
115
116	static int do_as_client__status(void)
117	{
118	enum ipc_active_state state = fsmonitor_ipc__get_state();
119
120	switch (state) {
121	case IPC_STATE__LISTENING:
122	printf(_("fsmonitor-daemon is watching '%s'\n"),
123	the_repository->worktree);
124	return 0;
125
126	default:
127	printf(_("fsmonitor-daemon is not watching '%s'\n"),
128	the_repository->worktree);
129	return 1;
130	}
131	}
132
133	enum fsmonitor_cookie_item_result {
134	FCIR_ERROR = -1, /* could not create cookie file ? */
135	FCIR_INIT,
136	FCIR_SEEN,
137	FCIR_ABORT,
138	};
139
140	struct fsmonitor_cookie_item {
141	struct hashmap_entry entry;
142	char *name;
143	enum fsmonitor_cookie_item_result result;
144	};
145
146	static int cookies_cmp(const void *data UNUSED,
147	const struct hashmap_entry *he1,
148	const struct hashmap_entry he2, const void keydata)
149	{
150	const struct fsmonitor_cookie_item *a =
151	container_of(he1, const struct fsmonitor_cookie_item, entry);
152	const struct fsmonitor_cookie_item *b =
153	container_of(he2, const struct fsmonitor_cookie_item, entry);
154
155	return strcmp(a->name, keydata ? keydata : b->name);
156	}
157
158	static enum fsmonitor_cookie_item_result with_lock__wait_for_cookie(
159	struct fsmonitor_daemon_state *state)
160	{
161	/* assert current thread holding state->main_lock */
162
163	int fd;
164	struct fsmonitor_cookie_item *cookie;
165	struct strbuf cookie_pathname = STRBUF_INIT;
166	struct strbuf cookie_filename = STRBUF_INIT;
167	enum fsmonitor_cookie_item_result result;
168	int my_cookie_seq;
169
170	CALLOC_ARRAY(cookie, 1);
171
172	my_cookie_seq = state->cookie_seq++;
173
174	strbuf_addf(&cookie_filename, "%i-%i", getpid(), my_cookie_seq);
175
176	strbuf_addbuf(&cookie_pathname, &state->path_cookie_prefix);
177	strbuf_addbuf(&cookie_pathname, &cookie_filename);
178
179	cookie->name = strbuf_detach(&cookie_filename, NULL);
180	cookie->result = FCIR_INIT;
181	hashmap_entry_init(&cookie->entry, strhash(cookie->name));
182
183	hashmap_add(&state->cookies, &cookie->entry);
184
185	trace_printf_key(&trace_fsmonitor, "cookie-wait: '%s' '%s'",
186	cookie->name, cookie_pathname.buf);
187
188	/*
189	* Create the cookie file on disk and then wait for a notification
190	* that the listener thread has seen it.
191	*/
192	fd = open(cookie_pathname.buf, O_WRONLY \| O_CREAT \| O_EXCL, 0600);
193	if (fd < 0) {
194	error_errno(_("could not create fsmonitor cookie '%s'"),
195	cookie->name);
196
197	cookie->result = FCIR_ERROR;
198	goto done;
199	}
200
201	/*
202	* Technically, close() and unlink() can fail, but we don't
203	* care here. We only created the file to trigger a watch
204	* event from the FS to know that when we're up to date.
205	*/
206	close(fd);
207	unlink(cookie_pathname.buf);
208
209	/* The listener callback takes main_lock, so this must not block. */
210	fsm_listen__flush_async(state);
211
212	/*
213	* Wait for the listener thread to observe the cookie file.
214	* Time out after a short interval so that the client
215	* does not hang forever if the filesystem does not deliver
216	* events (e.g., on certain container/overlay filesystems
217	* where inotify watches succeed but events never arrive).
218	*/
219	{
220	struct timeval now;
221	struct timespec ts;
222	int err = 0;
223
224	gettimeofday(&now, NULL);
225	ts.tv_sec = now.tv_sec + 1;
226	ts.tv_nsec = now.tv_usec * 1000;
227
228	while (cookie->result == FCIR_INIT && !err)
229	err = pthread_cond_timedwait(&state->cookies_cond,
230	&state->main_lock,
231	&ts);
232	if (err == ETIMEDOUT && cookie->result == FCIR_INIT) {
233	trace_printf_key(&trace_fsmonitor,
234	"cookie_wait timed out");
235	cookie->result = FCIR_ERROR;
236	}
237	}
238
239	done:
240	hashmap_remove(&state->cookies, &cookie->entry, NULL);
241
242	result = cookie->result;
243
244	free(cookie->name);
245	free(cookie);
246	strbuf_release(&cookie_pathname);
247
248	return result;
249	}
250
251	/*
252	* Mark these cookies as _SEEN and wake up the corresponding client threads.
253	*/
254	static void with_lock__mark_cookies_seen(struct fsmonitor_daemon_state *state,
255	const struct string_list *cookie_names)
256	{
257	/* assert current thread holding state->main_lock */
258
259	int k;
260	int nr_seen = 0;
261
262	for (k = 0; k < cookie_names->nr; k++) {
263	struct fsmonitor_cookie_item key;
264	struct fsmonitor_cookie_item *cookie;
265
266	key.name = cookie_names->items[k].string;
267	hashmap_entry_init(&key.entry, strhash(key.name));
268
269	cookie = hashmap_get_entry(&state->cookies, &key, entry, NULL);
270	if (cookie) {
271	trace_printf_key(&trace_fsmonitor, "cookie-seen: '%s'",
272	cookie->name);
273	cookie->result = FCIR_SEEN;
274	nr_seen++;
275	}
276	}
277
278	if (nr_seen)
279	pthread_cond_broadcast(&state->cookies_cond);
280	}
281
282	/*
283	* Set _ABORT on all pending cookies and wake up all client threads.
284	*/
285	static void with_lock__abort_all_cookies(struct fsmonitor_daemon_state *state)
286	{
287	/* assert current thread holding state->main_lock */
288
289	struct hashmap_iter iter;
290	struct fsmonitor_cookie_item *cookie;
291	int nr_aborted = 0;
292
293	hashmap_for_each_entry(&state->cookies, &iter, cookie, entry) {
294	trace_printf_key(&trace_fsmonitor, "cookie-abort: '%s'",
295	cookie->name);
296	cookie->result = FCIR_ABORT;
297	nr_aborted++;
298	}
299
300	if (nr_aborted)
301	pthread_cond_broadcast(&state->cookies_cond);
302	}
303
304	/*
305	* Requests to and from a FSMonitor Protocol V2 provider use an opaque
306	* "token" as a virtual timestamp. Clients can request a summary of all
307	* created/deleted/modified files relative to a token. In the response,
308	* clients receive a new token for the next (relative) request.
309	*
310	*
311	* Token Format
312	* ============
313	*
314	* The contents of the token are private and provider-specific.
315	*
316	* For the built-in fsmonitor--daemon, we define a token as follows:
317	*
318	* "builtin" ":" <token_id> ":" <sequence_nr>
319	*
320	* The "builtin" prefix is used as a namespace to avoid conflicts
321	* with other providers (such as Watchman).
322	*
323	* The <token_id> is an arbitrary OPAQUE string, such as a GUID,
324	* UUID, or {timestamp,pid}. It is used to group all filesystem
325	* events that happened while the daemon was monitoring (and in-sync
326	* with the filesystem).
327	*
328	* Unlike FSMonitor Protocol V1, it is not defined as a timestamp
329	* and does not define less-than/greater-than relationships.
330	* (There are too many race conditions to rely on file system
331	* event timestamps.)
332	*
333	* The <sequence_nr> is a simple integer incremented whenever the
334	* daemon needs to make its state public. For example, if 1000 file
335	* system events come in, but no clients have requested the data,
336	* the daemon can continue to accumulate file changes in the same
337	* bin and does not need to advance the sequence number. However,
338	* as soon as a client does arrive, the daemon needs to start a new
339	* bin and increment the sequence number.
340	*
341	* The sequence number serves as the boundary between 2 sets
342	* of bins -- the older ones that the client has already seen
343	* and the newer ones that it hasn't.
344	*
345	* When a new <token_id> is created, the <sequence_nr> is reset to
346	* zero.
347	*
348	*
349	* About Token Ids
350	* ===============
351	*
352	* A new token_id is created:
353	*
354	* [1] each time the daemon is started.
355	*
356	* [2] any time that the daemon must re-sync with the filesystem
357	* (such as when the kernel drops or we miss events on a very
358	* active volume).
359	*
360	* [3] in response to a client "flush" command (for dropped event
361	* testing).
362	*
363	* When a new token_id is created, the daemon is free to discard all
364	* cached filesystem events associated with any previous token_ids.
365	* Events associated with a non-current token_id will never be sent
366	* to a client. A token_id change implicitly means that the daemon
367	* has gap in its event history.
368	*
369	* Therefore, clients that present a token with a stale (non-current)
370	* token_id will always be given a trivial response.
371	*/
372	struct fsmonitor_token_data {
373	struct strbuf token_id;
374	struct fsmonitor_batch *batch_head;
375	struct fsmonitor_batch *batch_tail;
376	uint64_t client_ref_count;
377	};
378
379	struct fsmonitor_batch {
380	struct fsmonitor_batch *next;
381	uint64_t batch_seq_nr;
382	const char **interned_paths;
383	size_t nr, alloc;
384	time_t pinned_time;
385	};
386
387	static struct fsmonitor_token_data *fsmonitor_new_token_data(void)
388	{
389	static int test_env_value = -1;
390	static uint64_t flush_count = 0;
391	struct fsmonitor_token_data *token;
392	struct fsmonitor_batch *batch;
393
394	CALLOC_ARRAY(token, 1);
395	batch = fsmonitor_batch__new();
396
397	strbuf_init(&token->token_id, 0);
398	token->batch_head = batch;
399	token->batch_tail = batch;
400	token->client_ref_count = 0;
401
402	if (test_env_value < 0)
403	test_env_value = git_env_bool("GIT_TEST_FSMONITOR_TOKEN", 0);
404
405	if (!test_env_value) {
406	struct timeval tv;
407	struct tm tm;
408	time_t secs;
409
410	gettimeofday(&tv, NULL);
411	secs = tv.tv_sec;
412	gmtime_r(&secs, &tm);
413
414	strbuf_addf(&token->token_id,
415	"%"PRIu64".%d.%4d%02d%02dT%02d%02d%02d.%06ldZ",
416	flush_count++,
417	getpid(),
418	tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
419	tm.tm_hour, tm.tm_min, tm.tm_sec,
420	(long)tv.tv_usec);
421	} else {
422	strbuf_addf(&token->token_id, "test_%08x", test_env_value++);
423	}
424
425	/*
426	* We created a new <token_id> and are starting a new series
427	* of tokens with a zero <seq_nr>.
428	*
429	* Since clients cannot guess our new (non test) <token_id>
430	* they will always receive a trivial response (because of the
431	* mismatch on the <token_id>). The trivial response will
432	* tell them our new <token_id> so that subsequent requests
433	* will be relative to our new series. (And when sending that
434	* response, we pin the current head of the batch list.)
435	*
436	* Even if the client correctly guesses the <token_id>, their
437	* request of "builtin:<token_id>:0" asks for all changes MORE
438	* RECENT than batch/bin 0.
439	*
440	* This implies that it is a waste to accumulate paths in the
441	* initial batch/bin (because they will never be transmitted).
442	*
443	* So the daemon could be running for days and watching the
444	* file system, but doesn't need to actually accumulate any
445	* paths UNTIL we need to set a reference point for a later
446	* relative request.
447	*
448	* However, it is very useful for testing to always have a
449	* reference point set. Pin batch 0 to force early file system
450	* events to accumulate.
451	*/
452	if (test_env_value)
453	batch->pinned_time = time(NULL);
454
455	return token;
456	}
457
458	struct fsmonitor_batch *fsmonitor_batch__new(void)
459	{
460	struct fsmonitor_batch *batch;
461
462	CALLOC_ARRAY(batch, 1);
463
464	return batch;
465	}
466
467	void fsmonitor_batch__free_list(struct fsmonitor_batch *batch)
468	{
469	while (batch) {
470	struct fsmonitor_batch *next = batch->next;
471
472	/*
473	* The actual strings within the array of this batch
474	* are interned, so we don't own them. We only own
475	* the array.
476	*/
477	free(batch->interned_paths);
478	free(batch);
479
480	batch = next;
481	}
482	}
483
484	void fsmonitor_batch__add_path(struct fsmonitor_batch *batch,
485	const char *path)
486	{
487	const char *interned_path = strintern(path);
488
489	trace_printf_key(&trace_fsmonitor, "event: %s", interned_path);
490
491	ALLOC_GROW(batch->interned_paths, batch->nr + 1, batch->alloc);
492	batch->interned_paths[batch->nr++] = interned_path;
493	}
494
495	static void fsmonitor_batch__combine(struct fsmonitor_batch *batch_dest,
496	const struct fsmonitor_batch *batch_src)
497	{
498	size_t k;
499
500	ALLOC_GROW(batch_dest->interned_paths,
501	batch_dest->nr + batch_src->nr + 1,
502	batch_dest->alloc);
503
504	for (k = 0; k < batch_src->nr; k++)
505	batch_dest->interned_paths[batch_dest->nr++] =
506	batch_src->interned_paths[k];
507	}
508
509	/*
510	* To keep the batch list from growing unbounded in response to filesystem
511	* activity, we try to truncate old batches from the end of the list as
512	* they become irrelevant.
513	*
514	* We assume that the .git/index will be updated with the most recent token
515	* any time the index is updated. And future commands will only ask for
516	* recent changes since that new token. So as tokens advance into the
517	* future, older batch items will never be requested/needed. So we can
518	* truncate them without loss of functionality.
519	*
520	* However, multiple commands may be talking to the daemon concurrently
521	* or perform a slow command, so a little "token skew" is possible.
522	* Therefore, we want this to be a little bit lazy and have a generous
523	* delay.
524	*
525	* The current reader thread walked backwards in time from `token->batch_head`
526	* back to `batch_marker` somewhere in the middle of the batch list.
527	*
528	* Let's walk backwards in time from that marker an arbitrary delay
529	* and truncate the list there. Note that these timestamps are completely
530	* artificial (based on when we pinned the batch item) and not on any
531	* filesystem activity.
532	*
533	* Return the obsolete portion of the list after we have removed it from
534	* the official list so that the caller can free it after leaving the lock.
535	*/
536	#define MY_TIME_DELAY_SECONDS (5 * 60) /* seconds */
537
538	static struct fsmonitor_batch *with_lock__truncate_old_batches(
539	struct fsmonitor_daemon_state *state,
540	const struct fsmonitor_batch *batch_marker)
541	{
542	/* assert current thread holding state->main_lock */
543
544	const struct fsmonitor_batch *batch;
545	struct fsmonitor_batch *remainder;
546
547	if (!batch_marker)
548	return NULL;
549
550	trace_printf_key(&trace_fsmonitor, "Truncate: mark (%"PRIu64",%"PRIu64")",
551	batch_marker->batch_seq_nr,
552	(uint64_t)batch_marker->pinned_time);
553
554	for (batch = batch_marker; batch; batch = batch->next) {
555	time_t t;
556
557	if (!batch->pinned_time) /* an overflow batch */
558	continue;
559
560	t = batch->pinned_time + MY_TIME_DELAY_SECONDS;
561	if (t > batch_marker->pinned_time) /* too close to marker */
562	continue;
563
564	goto truncate_past_here;
565	}
566
567	return NULL;
568
569	truncate_past_here:
570	state->current_token_data->batch_tail = (struct fsmonitor_batch *)batch;
571
572	remainder = ((struct fsmonitor_batch *)batch)->next;
573	((struct fsmonitor_batch *)batch)->next = NULL;
574
575	return remainder;
576	}
577
578	static void fsmonitor_free_token_data(struct fsmonitor_token_data *token)
579	{
580	if (!token)
581	return;
582
583	assert(token->client_ref_count == 0);
584
585	strbuf_release(&token->token_id);
586
587	fsmonitor_batch__free_list(token->batch_head);
588
589	free(token);
590	}
591
592	/*
593	* Flush all of our cached data about the filesystem. Call this if we
594	* lose sync with the filesystem and miss some notification events.
595	*
596	* [1] If we are missing events, then we no longer have a complete
597	* history of the directory (relative to our current start token).
598	* We should create a new token and start fresh (as if we just
599	* booted up).
600	*
601	* [2] Some of those lost events may have been for cookie files. We
602	* should assume the worst and abort them rather letting them starve.
603	*
604	* If there are no concurrent threads reading the current token data
605	* series, we can free it now. Otherwise, let the last reader free
606	* it.
607	*
608	* Either way, the old token data series is no longer associated with
609	* our state data.
610	*/
611	static void with_lock__do_force_resync(struct fsmonitor_daemon_state *state)
612	{
613	/* assert current thread holding state->main_lock */
614
615	struct fsmonitor_token_data *free_me = NULL;
616	struct fsmonitor_token_data *new_one = NULL;
617
618	new_one = fsmonitor_new_token_data();
619
620	if (state->current_token_data->client_ref_count == 0)
621	free_me = state->current_token_data;
622	state->current_token_data = new_one;
623
624	fsmonitor_free_token_data(free_me);
625
626	with_lock__abort_all_cookies(state);
627	}
628
629	void fsmonitor_force_resync(struct fsmonitor_daemon_state *state)
630	{
631	pthread_mutex_lock(&state->main_lock);
632	with_lock__do_force_resync(state);
633	pthread_mutex_unlock(&state->main_lock);
634	}
635
636	/*
637	* Format an opaque token string to send to the client.
638	*/
639	static void with_lock__format_response_token(
640	struct strbuf *response_token,
641	const struct strbuf *response_token_id,
642	const struct fsmonitor_batch *batch)
643	{
644	/* assert current thread holding state->main_lock */
645
646	strbuf_reset(response_token);
647	strbuf_addf(response_token, "builtin:%s:%"PRIu64,
648	response_token_id->buf, batch->batch_seq_nr);
649	}
650
651	/*
652	* Parse an opaque token from the client.
653	* Returns -1 on error.
654	*/
655	static int fsmonitor_parse_client_token(const char *buf_token,
656	struct strbuf *requested_token_id,
657	uint64_t *seq_nr)
658	{
659	const char *p;
660	char *p_end;
661
662	strbuf_reset(requested_token_id);
663	*seq_nr = 0;
664
665	if (!skip_prefix(buf_token, "builtin:", &p))
666	return -1;
667
668	while (p && p != ':')
669	strbuf_addch(requested_token_id, *p++);
670	if (!*p++)
671	return -1;
672
673	*seq_nr = (uint64_t)strtoumax(p, &p_end, 10);
674	if (*p_end)
675	return -1;
676
677	return 0;
678	}
679
680	static int do_handle_client(struct fsmonitor_daemon_state *state,
681	const char *command,
682	ipc_server_reply_cb *reply,
683	struct ipc_server_reply_data *reply_data)
684	{
685	struct fsmonitor_token_data *token_data = NULL;
686	struct strbuf response_token = STRBUF_INIT;
687	struct strbuf requested_token_id = STRBUF_INIT;
688	struct strbuf payload = STRBUF_INIT;
689	uint64_t requested_oldest_seq_nr = 0;
690	uint64_t total_response_len = 0;
691	const char *p;
692	const struct fsmonitor_batch *batch_head;
693	const struct fsmonitor_batch *batch;
694	struct fsmonitor_batch *remainder = NULL;
695	intmax_t count = 0, duplicates = 0;
696	struct strset shown = STRSET_INIT;
697	int do_trivial = 0;
698	int do_flush = 0;
699	int do_cookie = 0;
700	enum fsmonitor_cookie_item_result cookie_result;
701
702	/*
703	* We expect `command` to be of the form:
704	*
705	* <command> := quit NUL
706	* \| flush NUL
707	* \| <V1-time-since-epoch-ns> NUL
708	* \| <V2-opaque-fsmonitor-token> NUL
709	*/
710
711	if (!strcmp(command, "quit")) {
712	/*
713	* A client has requested over the socket/pipe that the
714	* daemon shutdown.
715	*
716	* Tell the IPC thread pool to shutdown (which completes
717	* the await in the main thread (which can stop the
718	* fsmonitor listener thread)).
719	*
720	* There is no reply to the client.
721	*/
722	return SIMPLE_IPC_QUIT;
723
724	} else if (!strcmp(command, "flush")) {
725	/*
726	* Flush all of our cached data and generate a new token
727	* just like if we lost sync with the filesystem.
728	*
729	* Then send a trivial response using the new token.
730	*/
731	do_flush = 1;
732	do_trivial = 1;
733
734	} else if (!skip_prefix(command, "builtin:", &p)) {
735	/* assume V1 timestamp or garbage */
736
737	char *p_end;
738
739	strtoumax(command, &p_end, 10);
740	trace_printf_key(&trace_fsmonitor,
741	((*p_end) ?
742	"fsmonitor: invalid command line '%s'" :
743	"fsmonitor: unsupported V1 protocol '%s'"),
744	command);
745	do_trivial = 1;
746	do_cookie = 1;
747
748	} else {
749	/* We have "builtin:" /
750	if (fsmonitor_parse_client_token(command, &requested_token_id,
751	&requested_oldest_seq_nr)) {
752	trace_printf_key(&trace_fsmonitor,
753	"fsmonitor: invalid V2 protocol token '%s'",
754	command);
755	do_trivial = 1;
756	do_cookie = 1;
757
758	} else {
759	/*
760	* We have a V2 valid token:
761	* "builtin:<token_id>:<seq_nr>"
762	*/
763	do_cookie = 1;
764	}
765	}
766
767	pthread_mutex_lock(&state->main_lock);
768
769	if (!state->current_token_data)
770	BUG("fsmonitor state does not have a current token");
771
772	/*
773	* Write a cookie file inside the directory being watched in
774	* an effort to flush out existing filesystem events that we
775	* actually care about. Suspend this client thread until we
776	* see the filesystem events for this cookie file.
777	*
778	* Creating the cookie lets us guarantee that our FS listener
779	* thread has drained the kernel queue and we are caught up
780	* with the kernel.
781	*
782	* If we cannot create the cookie (or otherwise guarantee that
783	* we are caught up), we send a trivial response. We have to
784	* assume that there might be some very, very recent activity
785	* on the FS still in flight.
786	*/
787	if (do_cookie) {
788	cookie_result = with_lock__wait_for_cookie(state);
789	if (cookie_result != FCIR_SEEN) {
790	error(_("fsmonitor: cookie_result '%d' != SEEN"),
791	cookie_result);
792	do_trivial = 1;
793	}
794	}
795
796	if (do_flush)
797	with_lock__do_force_resync(state);
798
799	/*
800	* We mark the current head of the batch list as "pinned" so
801	* that the listener thread will treat this item as read-only
802	* (and prevent any more paths from being added to it) from
803	* now on.
804	*/
805	token_data = state->current_token_data;
806	batch_head = token_data->batch_head;
807	((struct fsmonitor_batch *)batch_head)->pinned_time = time(NULL);
808
809	/*
810	* FSMonitor Protocol V2 requires that we send a response header
811	* with a "new current token" and then all of the paths that changed
812	* since the "requested token". We send the seq_nr of the just-pinned
813	* head batch so that future requests from a client will be relative
814	* to it.
815	*/
816	with_lock__format_response_token(&response_token,
817	&token_data->token_id, batch_head);
818
819	reply(reply_data, response_token.buf, response_token.len + 1);
820	total_response_len += response_token.len + 1;
821
822	trace2_data_string("fsmonitor", the_repository, "response/token",
823	response_token.buf);
824	trace_printf_key(&trace_fsmonitor, "response token: %s",
825	response_token.buf);
826
827	if (!do_trivial) {
828	if (strcmp(requested_token_id.buf, token_data->token_id.buf)) {
829	/*
830	* The client last spoke to a different daemon
831	* instance -OR- the daemon had to resync with
832	* the filesystem (and lost events), so reject.
833	*/
834	trace2_data_string("fsmonitor", the_repository,
835	"response/token", "different");
836	do_trivial = 1;
837
838	} else if (requested_oldest_seq_nr <
839	token_data->batch_tail->batch_seq_nr) {
840	/*
841	* The client wants older events than we have for
842	* this token_id. This means that the end of our
843	* batch list was truncated and we cannot give the
844	* client a complete snapshot relative to their
845	* request.
846	*/
847	trace_printf_key(&trace_fsmonitor,
848	"client requested truncated data");
849	do_trivial = 1;
850	}
851	}
852
853	if (do_trivial) {
854	pthread_mutex_unlock(&state->main_lock);
855
856	reply(reply_data, "/", 2);
857
858	trace2_data_intmax("fsmonitor", the_repository,
859	"response/trivial", 1);
860
861	goto cleanup;
862	}
863
864	/*
865	* We're going to hold onto a pointer to the current
866	* token-data while we walk the list of batches of files.
867	* During this time, we will NOT be under the lock.
868	* So we ref-count it.
869	*
870	* This allows the listener thread to continue prepending
871	* new batches of items to the token-data (which we'll ignore).
872	*
873	* AND it allows the listener thread to do a token-reset
874	* (and install a new `current_token_data`).
875	*/
876	token_data->client_ref_count++;
877
878	pthread_mutex_unlock(&state->main_lock);
879
880	/*
881	* The client request is relative to the token that they sent,
882	* so walk the batch list backwards from the current head back
883	* to the batch (sequence number) they named.
884	*
885	* We use a strset to de-dup the list of pathnames.
886	*
887	* NEEDSWORK: each batch contains a list of interned strings,
888	* so we only need to do pointer comparisons here to build the
889	* hash table. Currently, we're still comparing the string
890	* values.
891	*/
892	strset_init_with_options(&shown, NULL, 0);
893	for (batch = batch_head;
894	batch && batch->batch_seq_nr > requested_oldest_seq_nr;
895	batch = batch->next) {
896	size_t k;
897
898	for (k = 0; k < batch->nr; k++) {
899	const char *s = batch->interned_paths[k];
900	size_t s_len;
901
902	if (!strset_add(&shown, s))
903	duplicates++;
904	else {
905	trace_printf_key(&trace_fsmonitor,
906	"send[%"PRIuMAX"]: %s",
907	count, s);
908
909	/* Each path gets written with a trailing NUL */
910	s_len = strlen(s) + 1;
911
912	if (payload.len + s_len >=
913	LARGE_PACKET_DATA_MAX) {
914	reply(reply_data, payload.buf,
915	payload.len);
916	total_response_len += payload.len;
917	strbuf_reset(&payload);
918	}
919
920	strbuf_add(&payload, s, s_len);
921	count++;
922	}
923	}
924	}
925
926	if (payload.len) {
927	reply(reply_data, payload.buf, payload.len);
928	total_response_len += payload.len;
929	}
930
931	pthread_mutex_lock(&state->main_lock);
932
933	if (token_data->client_ref_count > 0)
934	token_data->client_ref_count--;
935
936	if (token_data->client_ref_count == 0) {
937	if (token_data != state->current_token_data) {
938	/*
939	* The listener thread did a token-reset while we were
940	* walking the batch list. Therefore, this token is
941	* stale and can be discarded completely. If we are
942	* the last reader thread using this token, we own
943	* that work.
944	*/
945	fsmonitor_free_token_data(token_data);
946	} else if (batch) {
947	/*
948	* We are holding the lock and are the only
949	* reader of the ref-counted portion of the
950	* list, so we get the honor of seeing if the
951	* list can be truncated to save memory.
952	*
953	* The main loop did not walk to the end of the
954	* list, so this batch is the first item in the
955	* batch-list that is older than the requested
956	* end-point sequence number. See if the tail
957	* end of the list is obsolete.
958	*/
959	remainder = with_lock__truncate_old_batches(state,
960	batch);
961	}
962	}
963
964	pthread_mutex_unlock(&state->main_lock);
965
966	if (remainder)
967	fsmonitor_batch__free_list(remainder);
968
969	trace2_data_intmax("fsmonitor", the_repository, "response/length", total_response_len);
970	trace2_data_intmax("fsmonitor", the_repository, "response/count/files", count);
971	trace2_data_intmax("fsmonitor", the_repository, "response/count/duplicates", duplicates);
972
973	cleanup:
974	strset_clear(&shown);
975	strbuf_release(&response_token);
976	strbuf_release(&requested_token_id);
977	strbuf_release(&payload);
978
979	return 0;
980	}
981
982	static ipc_server_application_cb handle_client;
983
984	static int handle_client(void *data,
985	const char *command, size_t command_len,
986	ipc_server_reply_cb *reply,
987	struct ipc_server_reply_data *reply_data)
988	{
989	struct fsmonitor_daemon_state *state = data;
990	int result;
991
992	/*
993	* The Simple IPC API now supports {char*, len} arguments, but
994	* FSMonitor always uses proper null-terminated strings, so
995	* we can ignore the command_len argument. (Trust, but verify.)
996	*/
997	if (command_len != strlen(command))
998	BUG("FSMonitor assumes text messages");
999
1000	trace_printf_key(&trace_fsmonitor, "requested token: %s", command);
1001
1002	trace2_region_enter("fsmonitor", "handle_client", the_repository);
1003	trace2_data_string("fsmonitor", the_repository, "request", command);
1004
1005	result = do_handle_client(state, command, reply, reply_data);
1006
1007	trace2_region_leave("fsmonitor", "handle_client", the_repository);
1008
1009	return result;
1010	}
1011
1012	#define FSMONITOR_DIR "fsmonitor--daemon"
1013	#define FSMONITOR_COOKIE_DIR "cookies"
1014	#define FSMONITOR_COOKIE_PREFIX (FSMONITOR_DIR "/" FSMONITOR_COOKIE_DIR "/")
1015
1016	enum fsmonitor_path_type fsmonitor_classify_path_workdir_relative(
1017	const char *rel)
1018	{
1019	if (fspathncmp(rel, ".git", 4))
1020	return IS_WORKDIR_PATH;
1021	rel += 4;
1022
1023	if (!*rel)
1024	return IS_DOT_GIT;
1025	if (*rel != '/')
1026	return IS_WORKDIR_PATH; /* e.g. .gitignore */
1027	rel++;
1028
1029	if (!fspathncmp(rel, FSMONITOR_COOKIE_PREFIX,
1030	strlen(FSMONITOR_COOKIE_PREFIX)))
1031	return IS_INSIDE_DOT_GIT_WITH_COOKIE_PREFIX;
1032
1033	return IS_INSIDE_DOT_GIT;
1034	}
1035
1036	enum fsmonitor_path_type fsmonitor_classify_path_gitdir_relative(
1037	const char *rel)
1038	{
1039	if (!fspathncmp(rel, FSMONITOR_COOKIE_PREFIX,
1040	strlen(FSMONITOR_COOKIE_PREFIX)))
1041	return IS_INSIDE_GITDIR_WITH_COOKIE_PREFIX;
1042
1043	return IS_INSIDE_GITDIR;
1044	}
1045
1046	static enum fsmonitor_path_type try_classify_workdir_abs_path(
1047	struct fsmonitor_daemon_state *state,
1048	const char *path)
1049	{
1050	const char *rel;
1051
1052	if (fspathncmp(path, state->path_worktree_watch.buf,
1053	state->path_worktree_watch.len))
1054	return IS_OUTSIDE_CONE;
1055
1056	rel = path + state->path_worktree_watch.len;
1057
1058	if (!*rel)
1059	return IS_WORKDIR_PATH; /* it is the root dir exactly */
1060	if (*rel != '/')
1061	return IS_OUTSIDE_CONE;
1062	rel++;
1063
1064	return fsmonitor_classify_path_workdir_relative(rel);
1065	}
1066
1067	enum fsmonitor_path_type fsmonitor_classify_path_absolute(
1068	struct fsmonitor_daemon_state *state,
1069	const char *path)
1070	{
1071	const char *rel;
1072	enum fsmonitor_path_type t;
1073
1074	t = try_classify_workdir_abs_path(state, path);
1075	if (state->nr_paths_watching == 1)
1076	return t;
1077	if (t != IS_OUTSIDE_CONE)
1078	return t;
1079
1080	if (fspathncmp(path, state->path_gitdir_watch.buf,
1081	state->path_gitdir_watch.len))
1082	return IS_OUTSIDE_CONE;
1083
1084	rel = path + state->path_gitdir_watch.len;
1085
1086	if (!*rel)
1087	return IS_GITDIR; /* it is the <gitdir> exactly */
1088	if (*rel != '/')
1089	return IS_OUTSIDE_CONE;
1090	rel++;
1091
1092	return fsmonitor_classify_path_gitdir_relative(rel);
1093	}
1094
1095	/*
1096	* We try to combine small batches at the front of the batch-list to avoid
1097	* having a long list. This hopefully makes it a little easier when we want
1098	* to truncate and maintain the list. However, we don't want the paths array
1099	* to just keep growing and growing with realloc, so we insert an arbitrary
1100	* limit.
1101	*/
1102	#define MY_COMBINE_LIMIT (1024)
1103
1104	void fsmonitor_publish(struct fsmonitor_daemon_state *state,
1105	struct fsmonitor_batch *batch,
1106	const struct string_list *cookie_names)
1107	{
1108	if (!batch && !cookie_names->nr)
1109	return;
1110
1111	pthread_mutex_lock(&state->main_lock);
1112
1113	if (batch) {
1114	struct fsmonitor_batch *head;
1115
1116	head = state->current_token_data->batch_head;
1117	if (!head) {
1118	BUG("token does not have batch");
1119	} else if (head->pinned_time) {
1120	/*
1121	* We cannot alter the current batch list
1122	* because:
1123	*
1124	* [a] it is being transmitted to at least one
1125	* client and the handle_client() thread has a
1126	* ref-count, but not a lock on the batch list
1127	* starting with this item.
1128	*
1129	* [b] it has been transmitted in the past to
1130	* at least one client such that future
1131	* requests are relative to this head batch.
1132	*
1133	* So, we can only prepend a new batch onto
1134	* the front of the list.
1135	*/
1136	batch->batch_seq_nr = head->batch_seq_nr + 1;
1137	batch->next = head;
1138	state->current_token_data->batch_head = batch;
1139	} else if (!head->batch_seq_nr) {
1140	/*
1141	* Batch 0 is unpinned. See the note in
1142	* `fsmonitor_new_token_data()` about why we
1143	* don't need to accumulate these paths.
1144	*/
1145	fsmonitor_batch__free_list(batch);
1146	} else if (head->nr + batch->nr > MY_COMBINE_LIMIT) {
1147	/*
1148	* The head batch in the list has never been
1149	* transmitted to a client, but folding the
1150	* contents of the new batch onto it would
1151	* exceed our arbitrary limit, so just prepend
1152	* the new batch onto the list.
1153	*/
1154	batch->batch_seq_nr = head->batch_seq_nr + 1;
1155	batch->next = head;
1156	state->current_token_data->batch_head = batch;
1157	} else {
1158	/*
1159	* We are free to add the paths in the given
1160	* batch onto the end of the current head batch.
1161	*/
1162	fsmonitor_batch__combine(head, batch);
1163	fsmonitor_batch__free_list(batch);
1164	}
1165	}
1166
1167	if (cookie_names->nr)
1168	with_lock__mark_cookies_seen(state, cookie_names);
1169
1170	pthread_mutex_unlock(&state->main_lock);
1171	}
1172
1173	static void fsm_health__thread_proc(void _state)
1174	{
1175	struct fsmonitor_daemon_state *state = _state;
1176
1177	trace2_thread_start("fsm-health");
1178
1179	fsm_health__loop(state);
1180
1181	trace2_thread_exit();
1182	return NULL;
1183	}
1184
1185	static void fsm_listen__thread_proc(void _state)
1186	{
1187	struct fsmonitor_daemon_state *state = _state;
1188
1189	trace2_thread_start("fsm-listen");
1190
1191	trace_printf_key(&trace_fsmonitor, "Watching: worktree '%s'",
1192	state->path_worktree_watch.buf);
1193	if (state->nr_paths_watching > 1)
1194	trace_printf_key(&trace_fsmonitor, "Watching: gitdir '%s'",
1195	state->path_gitdir_watch.buf);
1196
1197	fsm_listen__loop(state);
1198
1199	pthread_mutex_lock(&state->main_lock);
1200	if (state->current_token_data &&
1201	state->current_token_data->client_ref_count == 0)
1202	fsmonitor_free_token_data(state->current_token_data);
1203	state->current_token_data = NULL;
1204	pthread_mutex_unlock(&state->main_lock);
1205
1206	trace2_thread_exit();
1207	return NULL;
1208	}
1209
1210	static int fsmonitor_run_daemon_1(struct fsmonitor_daemon_state *state)
1211	{
1212	struct ipc_server_opts ipc_opts = {
1213	.nr_threads = fsmonitor__ipc_threads,
1214
1215	/*
1216	* We know that there are no other active threads yet,
1217	* so we can let the IPC layer temporarily chdir() if
1218	* it needs to when creating the server side of the
1219	* Unix domain socket.
1220	*/
1221	.uds_disallow_chdir = 0
1222	};
1223	int health_started = 0;
1224	int listener_started = 0;
1225	int err = 0;
1226
1227	/*
1228	* Start the IPC thread pool before the we've started the file
1229	* system event listener thread so that we have the IPC handle
1230	* before we need it.
1231	*/
1232	if (ipc_server_init_async(&state->ipc_server_data,
1233	state->path_ipc.buf, &ipc_opts,
1234	handle_client, state))
1235	return error_errno(
1236	_("could not start IPC thread pool on '%s'"),
1237	state->path_ipc.buf);
1238
1239	/*
1240	* Start the fsmonitor listener thread to collect filesystem
1241	* events.
1242	*/
1243	if (pthread_create(&state->listener_thread, NULL,
1244	fsm_listen__thread_proc, state)) {
1245	ipc_server_stop_async(state->ipc_server_data);
1246	err = error(_("could not start fsmonitor listener thread"));
1247	goto cleanup;
1248	}
1249	listener_started = 1;
1250
1251	/*
1252	* Start the health thread to watch over our process.
1253	*/
1254	if (pthread_create(&state->health_thread, NULL,
1255	fsm_health__thread_proc, state)) {
1256	ipc_server_stop_async(state->ipc_server_data);
1257	err = error(_("could not start fsmonitor health thread"));
1258	goto cleanup;
1259	}
1260	health_started = 1;
1261
1262	/*
1263	* The daemon is now fully functional in background threads.
1264	* Our primary thread should now just wait while the threads
1265	* do all the work.
1266	*/
1267	cleanup:
1268	/*
1269	* Wait for the IPC thread pool to shutdown (whether by client
1270	* request, from filesystem activity, or an error).
1271	*/
1272	ipc_server_await(state->ipc_server_data);
1273
1274	/*
1275	* The fsmonitor listener thread may have received a shutdown
1276	* event from the IPC thread pool, but it doesn't hurt to tell
1277	* it again. And wait for it to shutdown.
1278	*/
1279	if (listener_started) {
1280	fsm_listen__stop_async(state);
1281	pthread_join(state->listener_thread, NULL);
1282	}
1283
1284	if (health_started) {
1285	fsm_health__stop_async(state);
1286	pthread_join(state->health_thread, NULL);
1287	}
1288
1289	if (err)
1290	return err;
1291	if (state->listen_error_code)
1292	return state->listen_error_code;
1293	if (state->health_error_code)
1294	return state->health_error_code;
1295	return 0;
1296	}
1297
1298	static int fsmonitor_run_daemon(void)
1299	{
1300	struct fsmonitor_daemon_state state;
1301	const char *home;
1302	int err;
1303
1304	memset(&state, 0, sizeof(state));
1305
1306	hashmap_init(&state.cookies, cookies_cmp, NULL, 0);
1307	pthread_mutex_init(&state.main_lock, NULL);
1308	pthread_cond_init(&state.cookies_cond, NULL);
1309	state.listen_error_code = 0;
1310	state.health_error_code = 0;
1311	state.current_token_data = fsmonitor_new_token_data();
1312
1313	/* Prepare to (recursively) watch the <worktree-root> directory. */
1314	strbuf_init(&state.path_worktree_watch, 0);
1315	strbuf_addstr(&state.path_worktree_watch,
1316	absolute_path(repo_get_work_tree(the_repository)));
1317	state.nr_paths_watching = 1;
1318
1319	strbuf_init(&state.alias.alias, 0);
1320	strbuf_init(&state.alias.points_to, 0);
1321	if ((err = fsmonitor__get_alias(state.path_worktree_watch.buf, &state.alias)))
1322	goto done;
1323
1324	/*
1325	* We create and delete cookie files somewhere inside the .git
1326	* directory to help us keep sync with the file system. If
1327	* ".git" is not a directory, then <gitdir> is not inside the
1328	* cone of <worktree-root>, so set up a second watch to watch
1329	* the <gitdir> so that we get events for the cookie files.
1330	*/
1331	strbuf_init(&state.path_gitdir_watch, 0);
1332	strbuf_addbuf(&state.path_gitdir_watch, &state.path_worktree_watch);
1333	strbuf_addstr(&state.path_gitdir_watch, "/.git");
1334	if (!is_directory(state.path_gitdir_watch.buf)) {
1335	strbuf_reset(&state.path_gitdir_watch);
1336	strbuf_addstr(&state.path_gitdir_watch,
1337	absolute_path(repo_get_git_dir(the_repository)));
1338	strbuf_strip_suffix(&state.path_gitdir_watch, "/.");
1339	state.nr_paths_watching = 2;
1340	}
1341
1342	/*
1343	* We will write filesystem syncing cookie files into
1344	* <gitdir>/<fsmonitor-dir>/<cookie-dir>/<pid>-<seq>.
1345	*
1346	* The extra layers of subdirectories here keep us from
1347	* changing the mtime on ".git/" or ".git/foo/" when we create
1348	* or delete cookie files.
1349	*
1350	* There have been problems with some IDEs that do a
1351	* non-recursive watch of the ".git/" directory and run a
1352	* series of commands any time something happens.
1353	*
1354	* For example, if we place our cookie files directly in
1355	* ".git/" or ".git/foo/" then a `git status` (or similar
1356	* command) from the IDE will cause a cookie file to be
1357	* created in one of those dirs. This causes the mtime of
1358	* those dirs to change. This triggers the IDE's watch
1359	* notification. This triggers the IDE to run those commands
1360	* again. And the process repeats and the machine never goes
1361	* idle.
1362	*
1363	* Adding the extra layers of subdirectories prevents the
1364	* mtime of ".git/" and ".git/foo" from changing when a
1365	* cookie file is created.
1366	*/
1367	strbuf_init(&state.path_cookie_prefix, 0);
1368	strbuf_addbuf(&state.path_cookie_prefix, &state.path_gitdir_watch);
1369
1370	strbuf_addch(&state.path_cookie_prefix, '/');
1371	strbuf_addstr(&state.path_cookie_prefix, FSMONITOR_DIR);
1372	mkdir(state.path_cookie_prefix.buf, 0777);
1373
1374	strbuf_addch(&state.path_cookie_prefix, '/');
1375	strbuf_addstr(&state.path_cookie_prefix, FSMONITOR_COOKIE_DIR);
1376	mkdir(state.path_cookie_prefix.buf, 0777);
1377
1378	strbuf_addch(&state.path_cookie_prefix, '/');
1379
1380	/*
1381	* We create a named-pipe or unix domain socket inside of the
1382	* ".git" directory. (Well, on Windows, we base our named
1383	* pipe in the NPFS on the absolute path of the git
1384	* directory.)
1385	*/
1386	strbuf_init(&state.path_ipc, 0);
1387	strbuf_addstr(&state.path_ipc,
1388	absolute_path(fsmonitor_ipc__get_path(the_repository)));
1389
1390	/*
1391	* Confirm that we can create platform-specific resources for the
1392	* filesystem listener before we bother starting all the threads.
1393	*/
1394	if (fsm_listen__ctor(&state)) {
1395	err = error(_("could not initialize listener thread"));
1396	goto done;
1397	}
1398
1399	if (fsm_health__ctor(&state)) {
1400	err = error(_("could not initialize health thread"));
1401	goto done;
1402	}
1403
1404	/*
1405	* CD out of the worktree root directory.
1406	*
1407	* The common Git startup mechanism causes our CWD to be the
1408	* root of the worktree. On Windows, this causes our process
1409	* to hold a locked handle on the CWD. This prevents the
1410	* worktree from being moved or deleted while the daemon is
1411	* running.
1412	*
1413	* We assume that our FS and IPC listener threads have either
1414	* opened all of the handles that they need or will do
1415	* everything using absolute paths.
1416	*/
1417	home = getenv("HOME");
1418	if (home && *home && chdir(home))
1419	die_errno(_("could not cd home '%s'"), home);
1420
1421	err = fsmonitor_run_daemon_1(&state);
1422
1423	done:
1424	fsmonitor_free_token_data(state.current_token_data);
1425	state.current_token_data = NULL;
1426	pthread_cond_destroy(&state.cookies_cond);
1427	pthread_mutex_destroy(&state.main_lock);
1428	{
1429	struct hashmap_iter iter;
1430	struct fsmonitor_cookie_item *cookie;
1431
1432	hashmap_for_each_entry(&state.cookies, &iter, cookie, entry)
1433	free(cookie->name);
1434	hashmap_clear_and_free(&state.cookies,
1435	struct fsmonitor_cookie_item, entry);
1436	}
1437	fsm_listen__dtor(&state);
1438	fsm_health__dtor(&state);
1439
1440	ipc_server_free(state.ipc_server_data);
1441
1442	strbuf_release(&state.path_worktree_watch);
1443	strbuf_release(&state.path_gitdir_watch);
1444	strbuf_release(&state.path_cookie_prefix);
1445	strbuf_release(&state.path_ipc);
1446	strbuf_release(&state.alias.alias);
1447	strbuf_release(&state.alias.points_to);
1448
1449	return err;
1450	}
1451
1452	static int try_to_run_foreground_daemon(int detach_console)
1453	{
1454	/*
1455	* Technically, we don't need to probe for an existing daemon
1456	* process, since we could just call `fsmonitor_run_daemon()`
1457	* and let it fail if the pipe/socket is busy.
1458	*
1459	* However, this method gives us a nicer error message for a
1460	* common error case.
1461	*/
1462	if (fsmonitor_ipc__get_state() == IPC_STATE__LISTENING)
1463	die(_("fsmonitor--daemon is already running '%s'"),
1464	the_repository->worktree);
1465
1466	if (fsmonitor__announce_startup) {
1467	fprintf(stderr, _("running fsmonitor-daemon in '%s'\n"),
1468	the_repository->worktree);
1469	fflush(stderr);
1470	}
1471
1472	if (detach_console) {
1473	#ifdef GIT_WINDOWS_NATIVE
1474	FreeConsole();
1475	#else
1476	/*
1477	* Create a new session so that the daemon is detached
1478	* from the parent's process group. This prevents
1479	* shells with job control (e.g. bash with "set -m")
1480	* from waiting on the daemon when they wait for a
1481	* foreground command that implicitly spawned it.
1482	*/
1483	if (setsid() == -1)
1484	warning_errno(_("setsid failed"));
1485	#endif
1486	}
1487
1488	return !!fsmonitor_run_daemon();
1489	}
1490
1491	static start_bg_wait_cb bg_wait_cb;
1492
1493	static int bg_wait_cb(const struct child_process *cp UNUSED,
1494	void *cb_data UNUSED)
1495	{
1496	enum ipc_active_state s = fsmonitor_ipc__get_state();
1497
1498	switch (s) {
1499	case IPC_STATE__LISTENING:
1500	/* child is "ready" */
1501	return 0;
1502
1503	case IPC_STATE__NOT_LISTENING:
1504	case IPC_STATE__PATH_NOT_FOUND:
1505	/* give child more time */
1506	return 1;
1507
1508	default:
1509	case IPC_STATE__INVALID_PATH:
1510	case IPC_STATE__OTHER_ERROR:
1511	/* all the time in world won't help */
1512	return -1;
1513	}
1514	}
1515
1516	static int try_to_start_background_daemon(void)
1517	{
1518	struct child_process cp = CHILD_PROCESS_INIT;
1519	enum start_bg_result sbgr;
1520
1521	/*
1522	* Before we try to create a background daemon process, see
1523	* if a daemon process is already listening. This makes it
1524	* easier for us to report an already-listening error to the
1525	* console, since our spawn/daemon can only report the success
1526	* of creating the background process (and not whether it
1527	* immediately exited).
1528	*/
1529	if (fsmonitor_ipc__get_state() == IPC_STATE__LISTENING)
1530	die(_("fsmonitor--daemon is already running '%s'"),
1531	the_repository->worktree);
1532
1533	if (fsmonitor__announce_startup) {
1534	fprintf(stderr, _("starting fsmonitor-daemon in '%s'\n"),
1535	the_repository->worktree);
1536	fflush(stderr);
1537	}
1538
1539	cp.git_cmd = 1;
1540
1541	strvec_push(&cp.args, "fsmonitor--daemon");
1542	strvec_push(&cp.args, "run");
1543	strvec_push(&cp.args, "--detach");
1544	strvec_pushf(&cp.args, "--ipc-threads=%d", fsmonitor__ipc_threads);
1545
1546	cp.no_stdin = 1;
1547	cp.no_stdout = 1;
1548	cp.no_stderr = 1;
1549	cp.close_fd_above_stderr = 1;
1550
1551	sbgr = start_bg_command(&cp, bg_wait_cb, NULL,
1552	fsmonitor__start_timeout_sec);
1553
1554	switch (sbgr) {
1555	case SBGR_READY:
1556	return 0;
1557
1558	default:
1559	case SBGR_ERROR:
1560	case SBGR_CB_ERROR:
1561	return error(_("daemon failed to start"));
1562
1563	case SBGR_TIMEOUT:
1564	return error(_("daemon not online yet"));
1565
1566	case SBGR_DIED:
1567	return error(_("daemon terminated"));
1568	}
1569	}
1570
1571	int cmd_fsmonitor__daemon(int argc,
1572	const char **argv,
1573	const char *prefix,
1574	struct repository *repo UNUSED)
1575	{
1576	const char *subcmd;
1577	enum fsmonitor_reason reason;
1578	int detach_console = 0;
1579
1580	struct option options[] = {
1581	OPT_BOOL(0, "detach", &detach_console, N_("detach from console")),
1582	OPT_INTEGER(0, "ipc-threads",
1583	&fsmonitor__ipc_threads,
1584	N_("use <n> ipc worker threads")),
1585	OPT_INTEGER(0, "start-timeout",
1586	&fsmonitor__start_timeout_sec,
1587	N_("max seconds to wait for background daemon startup")),
1588
1589	OPT_END()
1590	};
1591
1592	repo_config(the_repository, fsmonitor_config, NULL);
1593
1594	argc = parse_options(argc, argv, prefix, options,
1595	builtin_fsmonitor__daemon_usage, 0);
1596	if (argc != 1)
1597	usage_with_options(builtin_fsmonitor__daemon_usage, options);
1598	subcmd = argv[0];
1599
1600	if (fsmonitor__ipc_threads < 1)
1601	die(_("invalid 'ipc-threads' value (%d)"),
1602	fsmonitor__ipc_threads);
1603
1604	prepare_repo_settings(the_repository);
1605	/*
1606	* If the repo is fsmonitor-compatible, explicitly set IPC-mode
1607	* (without bothering to load the `core.fsmonitor` config settings).
1608	*
1609	* If the repo is not compatible, the repo-settings will be set to
1610	* incompatible rather than IPC, so we can use one of the __get
1611	* routines to detect the discrepancy.
1612	*/
1613	fsm_settings__set_ipc(the_repository);
1614
1615	reason = fsm_settings__get_reason(the_repository);
1616	if (reason > FSMONITOR_REASON_OK)
1617	die("%s",
1618	fsm_settings__get_incompatible_msg(the_repository,
1619	reason));
1620
1621	if (!strcmp(subcmd, "start"))
1622	return !!try_to_start_background_daemon();
1623
1624	if (!strcmp(subcmd, "run"))
1625	return !!try_to_run_foreground_daemon(detach_console);
1626
1627	if (!strcmp(subcmd, "stop"))
1628	return !!do_as_client__send_stop();
1629
1630	if (!strcmp(subcmd, "status"))
1631	return !!do_as_client__status();
1632
1633	die(_("Unhandled subcommand '%s'"), subcmd);
1634	}
1635
1636	#else
1637	int cmd_fsmonitor__daemon(int argc, const char *argv, const char prefix UNUSED, struct repository *repo UNUSED)
1638	{
1639	struct option options[] = {
1640	OPT_END()
1641	};
1642
1643	show_usage_with_options_if_asked(argc, argv,
1644	builtin_fsmonitor__daemon_usage, options);
1645
1646	die(_("fsmonitor--daemon not supported on this platform"));
1647	}
1648	#endif