#define USE_THE_REPOSITORY_VARIABLE #include "builtin.h" #include "abspath.h" #include "config.h" #include "dir.h" #include "gettext.h" #include "parse-options.h" #include "fsmonitor-ll.h" #include "fsmonitor-ipc.h" #include "fsmonitor-settings.h" #include "compat/fsmonitor/fsm-health.h" #include "compat/fsmonitor/fsm-listen.h" #include "fsmonitor--daemon.h" #include "simple-ipc.h" #include "khash.h" #include "run-command.h" #include "trace.h" #include "trace2.h" static const char * const builtin_fsmonitor__daemon_usage[] = …; #ifdef HAVE_FSMONITOR_DAEMON_BACKEND /* * Global state loaded from config. */ #define FSMONITOR__IPC_THREADS … static int fsmonitor__ipc_threads = 8; #define FSMONITOR__START_TIMEOUT … static int fsmonitor__start_timeout_sec = 60; #define FSMONITOR__ANNOUNCE_STARTUP … static int fsmonitor__announce_startup = 0; static int fsmonitor_config(const char *var, const char *value, const struct config_context *ctx, void *cb) { if (!strcmp(var, FSMONITOR__IPC_THREADS)) { int i = git_config_int(var, value, ctx->kvi); if (i < 1) return error(_("value of '%s' out of range: %d"), FSMONITOR__IPC_THREADS, i); fsmonitor__ipc_threads = i; return 0; } if (!strcmp(var, FSMONITOR__START_TIMEOUT)) { int i = git_config_int(var, value, ctx->kvi); if (i < 0) return error(_("value of '%s' out of range: %d"), FSMONITOR__START_TIMEOUT, i); fsmonitor__start_timeout_sec = i; return 0; } if (!strcmp(var, FSMONITOR__ANNOUNCE_STARTUP)) { int is_bool; int i = git_config_bool_or_int(var, value, ctx->kvi, &is_bool); if (i < 0) return error(_("value of '%s' not bool or int: %d"), var, i); fsmonitor__announce_startup = i; return 0; } return git_default_config(var, value, ctx, cb); } /* * Acting as a CLIENT. * * Send a "quit" command to the `git-fsmonitor--daemon` (if running) * and wait for it to shutdown. */ static int do_as_client__send_stop(void) { struct strbuf answer = STRBUF_INIT; int ret; ret = fsmonitor_ipc__send_command("quit", &answer); /* The quit command does not return any response data. */ strbuf_release(&answer); if (ret) return ret; trace2_region_enter("fsm_client", "polling-for-daemon-exit", NULL); while (fsmonitor_ipc__get_state() == IPC_STATE__LISTENING) sleep_millisec(50); trace2_region_leave("fsm_client", "polling-for-daemon-exit", NULL); return 0; } static int do_as_client__status(void) { enum ipc_active_state state = fsmonitor_ipc__get_state(); switch (state) { case IPC_STATE__LISTENING: printf(_("fsmonitor-daemon is watching '%s'\n"), the_repository->worktree); return 0; default: printf(_("fsmonitor-daemon is not watching '%s'\n"), the_repository->worktree); return 1; } } enum fsmonitor_cookie_item_result { FCIR_ERROR = -1, /* could not create cookie file ? */ FCIR_INIT, FCIR_SEEN, FCIR_ABORT, }; struct fsmonitor_cookie_item { struct hashmap_entry entry; char *name; enum fsmonitor_cookie_item_result result; }; static int cookies_cmp(const void *data UNUSED, const struct hashmap_entry *he1, const struct hashmap_entry *he2, const void *keydata) { const struct fsmonitor_cookie_item *a = container_of(he1, const struct fsmonitor_cookie_item, entry); const struct fsmonitor_cookie_item *b = container_of(he2, const struct fsmonitor_cookie_item, entry); return strcmp(a->name, keydata ? keydata : b->name); } static enum fsmonitor_cookie_item_result with_lock__wait_for_cookie( struct fsmonitor_daemon_state *state) { /* assert current thread holding state->main_lock */ int fd; struct fsmonitor_cookie_item *cookie; struct strbuf cookie_pathname = STRBUF_INIT; struct strbuf cookie_filename = STRBUF_INIT; enum fsmonitor_cookie_item_result result; int my_cookie_seq; CALLOC_ARRAY(cookie, 1); my_cookie_seq = state->cookie_seq++; strbuf_addf(&cookie_filename, "%i-%i", getpid(), my_cookie_seq); strbuf_addbuf(&cookie_pathname, &state->path_cookie_prefix); strbuf_addbuf(&cookie_pathname, &cookie_filename); cookie->name = strbuf_detach(&cookie_filename, NULL); cookie->result = FCIR_INIT; hashmap_entry_init(&cookie->entry, strhash(cookie->name)); hashmap_add(&state->cookies, &cookie->entry); trace_printf_key(&trace_fsmonitor, "cookie-wait: '%s' '%s'", cookie->name, cookie_pathname.buf); /* * Create the cookie file on disk and then wait for a notification * that the listener thread has seen it. */ fd = open(cookie_pathname.buf, O_WRONLY | O_CREAT | O_EXCL, 0600); if (fd < 0) { error_errno(_("could not create fsmonitor cookie '%s'"), cookie->name); cookie->result = FCIR_ERROR; goto done; } /* * Technically, close() and unlink() can fail, but we don't * care here. We only created the file to trigger a watch * event from the FS to know that when we're up to date. */ close(fd); unlink(cookie_pathname.buf); /* * Technically, this is an infinite wait (well, unless another * thread sends us an abort). I'd like to change this to * use `pthread_cond_timedwait()` and return an error/timeout * and let the caller do the trivial response thing, but we * don't have that routine in our thread-utils. * * After extensive beta testing I'm not really worried about * this. Also note that the above open() and unlink() calls * will cause at least two FS events on that path, so the odds * of getting stuck are pretty slim. */ while (cookie->result == FCIR_INIT) pthread_cond_wait(&state->cookies_cond, &state->main_lock); done: hashmap_remove(&state->cookies, &cookie->entry, NULL); result = cookie->result; free(cookie->name); free(cookie); strbuf_release(&cookie_pathname); return result; } /* * Mark these cookies as _SEEN and wake up the corresponding client threads. */ static void with_lock__mark_cookies_seen(struct fsmonitor_daemon_state *state, const struct string_list *cookie_names) { /* assert current thread holding state->main_lock */ int k; int nr_seen = 0; for (k = 0; k < cookie_names->nr; k++) { struct fsmonitor_cookie_item key; struct fsmonitor_cookie_item *cookie; key.name = cookie_names->items[k].string; hashmap_entry_init(&key.entry, strhash(key.name)); cookie = hashmap_get_entry(&state->cookies, &key, entry, NULL); if (cookie) { trace_printf_key(&trace_fsmonitor, "cookie-seen: '%s'", cookie->name); cookie->result = FCIR_SEEN; nr_seen++; } } if (nr_seen) pthread_cond_broadcast(&state->cookies_cond); } /* * Set _ABORT on all pending cookies and wake up all client threads. */ static void with_lock__abort_all_cookies(struct fsmonitor_daemon_state *state) { /* assert current thread holding state->main_lock */ struct hashmap_iter iter; struct fsmonitor_cookie_item *cookie; int nr_aborted = 0; hashmap_for_each_entry(&state->cookies, &iter, cookie, entry) { trace_printf_key(&trace_fsmonitor, "cookie-abort: '%s'", cookie->name); cookie->result = FCIR_ABORT; nr_aborted++; } if (nr_aborted) pthread_cond_broadcast(&state->cookies_cond); } /* * Requests to and from a FSMonitor Protocol V2 provider use an opaque * "token" as a virtual timestamp. Clients can request a summary of all * created/deleted/modified files relative to a token. In the response, * clients receive a new token for the next (relative) request. * * * Token Format * ============ * * The contents of the token are private and provider-specific. * * For the built-in fsmonitor--daemon, we define a token as follows: * * "builtin" ":" <token_id> ":" <sequence_nr> * * The "builtin" prefix is used as a namespace to avoid conflicts * with other providers (such as Watchman). * * The <token_id> is an arbitrary OPAQUE string, such as a GUID, * UUID, or {timestamp,pid}. It is used to group all filesystem * events that happened while the daemon was monitoring (and in-sync * with the filesystem). * * Unlike FSMonitor Protocol V1, it is not defined as a timestamp * and does not define less-than/greater-than relationships. * (There are too many race conditions to rely on file system * event timestamps.) * * The <sequence_nr> is a simple integer incremented whenever the * daemon needs to make its state public. For example, if 1000 file * system events come in, but no clients have requested the data, * the daemon can continue to accumulate file changes in the same * bin and does not need to advance the sequence number. However, * as soon as a client does arrive, the daemon needs to start a new * bin and increment the sequence number. * * The sequence number serves as the boundary between 2 sets * of bins -- the older ones that the client has already seen * and the newer ones that it hasn't. * * When a new <token_id> is created, the <sequence_nr> is reset to * zero. * * * About Token Ids * =============== * * A new token_id is created: * * [1] each time the daemon is started. * * [2] any time that the daemon must re-sync with the filesystem * (such as when the kernel drops or we miss events on a very * active volume). * * [3] in response to a client "flush" command (for dropped event * testing). * * When a new token_id is created, the daemon is free to discard all * cached filesystem events associated with any previous token_ids. * Events associated with a non-current token_id will never be sent * to a client. A token_id change implicitly means that the daemon * has gap in its event history. * * Therefore, clients that present a token with a stale (non-current) * token_id will always be given a trivial response. */ struct fsmonitor_token_data { struct strbuf token_id; struct fsmonitor_batch *batch_head; struct fsmonitor_batch *batch_tail; uint64_t client_ref_count; }; struct fsmonitor_batch { struct fsmonitor_batch *next; uint64_t batch_seq_nr; const char **interned_paths; size_t nr, alloc; time_t pinned_time; }; static struct fsmonitor_token_data *fsmonitor_new_token_data(void) { static int test_env_value = -1; static uint64_t flush_count = 0; struct fsmonitor_token_data *token; struct fsmonitor_batch *batch; CALLOC_ARRAY(token, 1); batch = fsmonitor_batch__new(); strbuf_init(&token->token_id, 0); token->batch_head = batch; token->batch_tail = batch; token->client_ref_count = 0; if (test_env_value < 0) test_env_value = git_env_bool("GIT_TEST_FSMONITOR_TOKEN", 0); if (!test_env_value) { struct timeval tv; struct tm tm; time_t secs; gettimeofday(&tv, NULL); secs = tv.tv_sec; gmtime_r(&secs, &tm); strbuf_addf(&token->token_id, "%"PRIu64".%d.%4d%02d%02dT%02d%02d%02d.%06ldZ", flush_count++, getpid(), tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec, (long)tv.tv_usec); } else { strbuf_addf(&token->token_id, "test_%08x", test_env_value++); } /* * We created a new <token_id> and are starting a new series * of tokens with a zero <seq_nr>. * * Since clients cannot guess our new (non test) <token_id> * they will always receive a trivial response (because of the * mismatch on the <token_id>). The trivial response will * tell them our new <token_id> so that subsequent requests * will be relative to our new series. (And when sending that * response, we pin the current head of the batch list.) * * Even if the client correctly guesses the <token_id>, their * request of "builtin:<token_id>:0" asks for all changes MORE * RECENT than batch/bin 0. * * This implies that it is a waste to accumulate paths in the * initial batch/bin (because they will never be transmitted). * * So the daemon could be running for days and watching the * file system, but doesn't need to actually accumulate any * paths UNTIL we need to set a reference point for a later * relative request. * * However, it is very useful for testing to always have a * reference point set. Pin batch 0 to force early file system * events to accumulate. */ if (test_env_value) batch->pinned_time = time(NULL); return token; } struct fsmonitor_batch *fsmonitor_batch__new(void) { struct fsmonitor_batch *batch; CALLOC_ARRAY(batch, 1); return batch; } void fsmonitor_batch__free_list(struct fsmonitor_batch *batch) { while (batch) { struct fsmonitor_batch *next = batch->next; /* * The actual strings within the array of this batch * are interned, so we don't own them. We only own * the array. */ free(batch->interned_paths); free(batch); batch = next; } } void fsmonitor_batch__add_path(struct fsmonitor_batch *batch, const char *path) { const char *interned_path = strintern(path); trace_printf_key(&trace_fsmonitor, "event: %s", interned_path); ALLOC_GROW(batch->interned_paths, batch->nr + 1, batch->alloc); batch->interned_paths[batch->nr++] = interned_path; } static void fsmonitor_batch__combine(struct fsmonitor_batch *batch_dest, const struct fsmonitor_batch *batch_src) { size_t k; ALLOC_GROW(batch_dest->interned_paths, batch_dest->nr + batch_src->nr + 1, batch_dest->alloc); for (k = 0; k < batch_src->nr; k++) batch_dest->interned_paths[batch_dest->nr++] = batch_src->interned_paths[k]; } /* * To keep the batch list from growing unbounded in response to filesystem * activity, we try to truncate old batches from the end of the list as * they become irrelevant. * * We assume that the .git/index will be updated with the most recent token * any time the index is updated. And future commands will only ask for * recent changes *since* that new token. So as tokens advance into the * future, older batch items will never be requested/needed. So we can * truncate them without loss of functionality. * * However, multiple commands may be talking to the daemon concurrently * or perform a slow command, so a little "token skew" is possible. * Therefore, we want this to be a little bit lazy and have a generous * delay. * * The current reader thread walked backwards in time from `token->batch_head` * back to `batch_marker` somewhere in the middle of the batch list. * * Let's walk backwards in time from that marker an arbitrary delay * and truncate the list there. Note that these timestamps are completely * artificial (based on when we pinned the batch item) and not on any * filesystem activity. * * Return the obsolete portion of the list after we have removed it from * the official list so that the caller can free it after leaving the lock. */ #define MY_TIME_DELAY_SECONDS … static struct fsmonitor_batch *with_lock__truncate_old_batches( struct fsmonitor_daemon_state *state, const struct fsmonitor_batch *batch_marker) { /* assert current thread holding state->main_lock */ const struct fsmonitor_batch *batch; struct fsmonitor_batch *remainder; if (!batch_marker) return NULL; trace_printf_key(&trace_fsmonitor, "Truncate: mark (%"PRIu64",%"PRIu64")", batch_marker->batch_seq_nr, (uint64_t)batch_marker->pinned_time); for (batch = batch_marker; batch; batch = batch->next) { time_t t; if (!batch->pinned_time) /* an overflow batch */ continue; t = batch->pinned_time + MY_TIME_DELAY_SECONDS; if (t > batch_marker->pinned_time) /* too close to marker */ continue; goto truncate_past_here; } return NULL; truncate_past_here: state->current_token_data->batch_tail = (struct fsmonitor_batch *)batch; remainder = ((struct fsmonitor_batch *)batch)->next; ((struct fsmonitor_batch *)batch)->next = NULL; return remainder; } static void fsmonitor_free_token_data(struct fsmonitor_token_data *token) { if (!token) return; assert(token->client_ref_count == 0); strbuf_release(&token->token_id); fsmonitor_batch__free_list(token->batch_head); free(token); } /* * Flush all of our cached data about the filesystem. Call this if we * lose sync with the filesystem and miss some notification events. * * [1] If we are missing events, then we no longer have a complete * history of the directory (relative to our current start token). * We should create a new token and start fresh (as if we just * booted up). * * [2] Some of those lost events may have been for cookie files. We * should assume the worst and abort them rather letting them starve. * * If there are no concurrent threads reading the current token data * series, we can free it now. Otherwise, let the last reader free * it. * * Either way, the old token data series is no longer associated with * our state data. */ static void with_lock__do_force_resync(struct fsmonitor_daemon_state *state) { /* assert current thread holding state->main_lock */ struct fsmonitor_token_data *free_me = NULL; struct fsmonitor_token_data *new_one = NULL; new_one = fsmonitor_new_token_data(); if (state->current_token_data->client_ref_count == 0) free_me = state->current_token_data; state->current_token_data = new_one; fsmonitor_free_token_data(free_me); with_lock__abort_all_cookies(state); } void fsmonitor_force_resync(struct fsmonitor_daemon_state *state) { pthread_mutex_lock(&state->main_lock); with_lock__do_force_resync(state); pthread_mutex_unlock(&state->main_lock); } /* * Format an opaque token string to send to the client. */ static void with_lock__format_response_token( struct strbuf *response_token, const struct strbuf *response_token_id, const struct fsmonitor_batch *batch) { /* assert current thread holding state->main_lock */ strbuf_reset(response_token); strbuf_addf(response_token, "builtin:%s:%"PRIu64, response_token_id->buf, batch->batch_seq_nr); } /* * Parse an opaque token from the client. * Returns -1 on error. */ static int fsmonitor_parse_client_token(const char *buf_token, struct strbuf *requested_token_id, uint64_t *seq_nr) { const char *p; char *p_end; strbuf_reset(requested_token_id); *seq_nr = 0; if (!skip_prefix(buf_token, "builtin:", &p)) return -1; while (*p && *p != ':') strbuf_addch(requested_token_id, *p++); if (!*p++) return -1; *seq_nr = (uint64_t)strtoumax(p, &p_end, 10); if (*p_end) return -1; return 0; } KHASH_INIT(str, const char *, int, 0, kh_str_hash_func, kh_str_hash_equal) static int do_handle_client(struct fsmonitor_daemon_state *state, const char *command, ipc_server_reply_cb *reply, struct ipc_server_reply_data *reply_data) { struct fsmonitor_token_data *token_data = NULL; struct strbuf response_token = STRBUF_INIT; struct strbuf requested_token_id = STRBUF_INIT; struct strbuf payload = STRBUF_INIT; uint64_t requested_oldest_seq_nr = 0; uint64_t total_response_len = 0; const char *p; const struct fsmonitor_batch *batch_head; const struct fsmonitor_batch *batch; struct fsmonitor_batch *remainder = NULL; intmax_t count = 0, duplicates = 0; kh_str_t *shown; int hash_ret; int do_trivial = 0; int do_flush = 0; int do_cookie = 0; enum fsmonitor_cookie_item_result cookie_result; /* * We expect `command` to be of the form: * * <command> := quit NUL * | flush NUL * | <V1-time-since-epoch-ns> NUL * | <V2-opaque-fsmonitor-token> NUL */ if (!strcmp(command, "quit")) { /* * A client has requested over the socket/pipe that the * daemon shutdown. * * Tell the IPC thread pool to shutdown (which completes * the await in the main thread (which can stop the * fsmonitor listener thread)). * * There is no reply to the client. */ return SIMPLE_IPC_QUIT; } else if (!strcmp(command, "flush")) { /* * Flush all of our cached data and generate a new token * just like if we lost sync with the filesystem. * * Then send a trivial response using the new token. */ do_flush = 1; do_trivial = 1; } else if (!skip_prefix(command, "builtin:", &p)) { /* assume V1 timestamp or garbage */ char *p_end; strtoumax(command, &p_end, 10); trace_printf_key(&trace_fsmonitor, ((*p_end) ? "fsmonitor: invalid command line '%s'" : "fsmonitor: unsupported V1 protocol '%s'"), command); do_trivial = 1; do_cookie = 1; } else { /* We have "builtin:*" */ if (fsmonitor_parse_client_token(command, &requested_token_id, &requested_oldest_seq_nr)) { trace_printf_key(&trace_fsmonitor, "fsmonitor: invalid V2 protocol token '%s'", command); do_trivial = 1; do_cookie = 1; } else { /* * We have a V2 valid token: * "builtin:<token_id>:<seq_nr>" */ do_cookie = 1; } } pthread_mutex_lock(&state->main_lock); if (!state->current_token_data) BUG("fsmonitor state does not have a current token"); /* * Write a cookie file inside the directory being watched in * an effort to flush out existing filesystem events that we * actually care about. Suspend this client thread until we * see the filesystem events for this cookie file. * * Creating the cookie lets us guarantee that our FS listener * thread has drained the kernel queue and we are caught up * with the kernel. * * If we cannot create the cookie (or otherwise guarantee that * we are caught up), we send a trivial response. We have to * assume that there might be some very, very recent activity * on the FS still in flight. */ if (do_cookie) { cookie_result = with_lock__wait_for_cookie(state); if (cookie_result != FCIR_SEEN) { error(_("fsmonitor: cookie_result '%d' != SEEN"), cookie_result); do_trivial = 1; } } if (do_flush) with_lock__do_force_resync(state); /* * We mark the current head of the batch list as "pinned" so * that the listener thread will treat this item as read-only * (and prevent any more paths from being added to it) from * now on. */ token_data = state->current_token_data; batch_head = token_data->batch_head; ((struct fsmonitor_batch *)batch_head)->pinned_time = time(NULL); /* * FSMonitor Protocol V2 requires that we send a response header * with a "new current token" and then all of the paths that changed * since the "requested token". We send the seq_nr of the just-pinned * head batch so that future requests from a client will be relative * to it. */ with_lock__format_response_token(&response_token, &token_data->token_id, batch_head); reply(reply_data, response_token.buf, response_token.len + 1); total_response_len += response_token.len + 1; trace2_data_string("fsmonitor", the_repository, "response/token", response_token.buf); trace_printf_key(&trace_fsmonitor, "response token: %s", response_token.buf); if (!do_trivial) { if (strcmp(requested_token_id.buf, token_data->token_id.buf)) { /* * The client last spoke to a different daemon * instance -OR- the daemon had to resync with * the filesystem (and lost events), so reject. */ trace2_data_string("fsmonitor", the_repository, "response/token", "different"); do_trivial = 1; } else if (requested_oldest_seq_nr < token_data->batch_tail->batch_seq_nr) { /* * The client wants older events than we have for * this token_id. This means that the end of our * batch list was truncated and we cannot give the * client a complete snapshot relative to their * request. */ trace_printf_key(&trace_fsmonitor, "client requested truncated data"); do_trivial = 1; } } if (do_trivial) { pthread_mutex_unlock(&state->main_lock); reply(reply_data, "/", 2); trace2_data_intmax("fsmonitor", the_repository, "response/trivial", 1); goto cleanup; } /* * We're going to hold onto a pointer to the current * token-data while we walk the list of batches of files. * During this time, we will NOT be under the lock. * So we ref-count it. * * This allows the listener thread to continue prepending * new batches of items to the token-data (which we'll ignore). * * AND it allows the listener thread to do a token-reset * (and install a new `current_token_data`). */ token_data->client_ref_count++; pthread_mutex_unlock(&state->main_lock); /* * The client request is relative to the token that they sent, * so walk the batch list backwards from the current head back * to the batch (sequence number) they named. * * We use khash to de-dup the list of pathnames. * * NEEDSWORK: each batch contains a list of interned strings, * so we only need to do pointer comparisons here to build the * hash table. Currently, we're still comparing the string * values. */ shown = kh_init_str(); for (batch = batch_head; batch && batch->batch_seq_nr > requested_oldest_seq_nr; batch = batch->next) { size_t k; for (k = 0; k < batch->nr; k++) { const char *s = batch->interned_paths[k]; size_t s_len; if (kh_get_str(shown, s) != kh_end(shown)) duplicates++; else { kh_put_str(shown, s, &hash_ret); trace_printf_key(&trace_fsmonitor, "send[%"PRIuMAX"]: %s", count, s); /* Each path gets written with a trailing NUL */ s_len = strlen(s) + 1; if (payload.len + s_len >= LARGE_PACKET_DATA_MAX) { reply(reply_data, payload.buf, payload.len); total_response_len += payload.len; strbuf_reset(&payload); } strbuf_add(&payload, s, s_len); count++; } } } if (payload.len) { reply(reply_data, payload.buf, payload.len); total_response_len += payload.len; } kh_release_str(shown); pthread_mutex_lock(&state->main_lock); if (token_data->client_ref_count > 0) token_data->client_ref_count--; if (token_data->client_ref_count == 0) { if (token_data != state->current_token_data) { /* * The listener thread did a token-reset while we were * walking the batch list. Therefore, this token is * stale and can be discarded completely. If we are * the last reader thread using this token, we own * that work. */ fsmonitor_free_token_data(token_data); } else if (batch) { /* * We are holding the lock and are the only * reader of the ref-counted portion of the * list, so we get the honor of seeing if the * list can be truncated to save memory. * * The main loop did not walk to the end of the * list, so this batch is the first item in the * batch-list that is older than the requested * end-point sequence number. See if the tail * end of the list is obsolete. */ remainder = with_lock__truncate_old_batches(state, batch); } } pthread_mutex_unlock(&state->main_lock); if (remainder) fsmonitor_batch__free_list(remainder); trace2_data_intmax("fsmonitor", the_repository, "response/length", total_response_len); trace2_data_intmax("fsmonitor", the_repository, "response/count/files", count); trace2_data_intmax("fsmonitor", the_repository, "response/count/duplicates", duplicates); cleanup: strbuf_release(&response_token); strbuf_release(&requested_token_id); strbuf_release(&payload); return 0; } static ipc_server_application_cb handle_client; static int handle_client(void *data, const char *command, size_t command_len, ipc_server_reply_cb *reply, struct ipc_server_reply_data *reply_data) { struct fsmonitor_daemon_state *state = data; int result; /* * The Simple IPC API now supports {char*, len} arguments, but * FSMonitor always uses proper null-terminated strings, so * we can ignore the command_len argument. (Trust, but verify.) */ if (command_len != strlen(command)) BUG("FSMonitor assumes text messages"); trace_printf_key(&trace_fsmonitor, "requested token: %s", command); trace2_region_enter("fsmonitor", "handle_client", the_repository); trace2_data_string("fsmonitor", the_repository, "request", command); result = do_handle_client(state, command, reply, reply_data); trace2_region_leave("fsmonitor", "handle_client", the_repository); return result; } #define FSMONITOR_DIR … #define FSMONITOR_COOKIE_DIR … #define FSMONITOR_COOKIE_PREFIX … enum fsmonitor_path_type fsmonitor_classify_path_workdir_relative( const char *rel) { if (fspathncmp(rel, ".git", 4)) return IS_WORKDIR_PATH; rel += 4; if (!*rel) return IS_DOT_GIT; if (*rel != '/') return IS_WORKDIR_PATH; /* e.g. .gitignore */ rel++; if (!fspathncmp(rel, FSMONITOR_COOKIE_PREFIX, strlen(FSMONITOR_COOKIE_PREFIX))) return IS_INSIDE_DOT_GIT_WITH_COOKIE_PREFIX; return IS_INSIDE_DOT_GIT; } enum fsmonitor_path_type fsmonitor_classify_path_gitdir_relative( const char *rel) { if (!fspathncmp(rel, FSMONITOR_COOKIE_PREFIX, strlen(FSMONITOR_COOKIE_PREFIX))) return IS_INSIDE_GITDIR_WITH_COOKIE_PREFIX; return IS_INSIDE_GITDIR; } static enum fsmonitor_path_type try_classify_workdir_abs_path( struct fsmonitor_daemon_state *state, const char *path) { const char *rel; if (fspathncmp(path, state->path_worktree_watch.buf, state->path_worktree_watch.len)) return IS_OUTSIDE_CONE; rel = path + state->path_worktree_watch.len; if (!*rel) return IS_WORKDIR_PATH; /* it is the root dir exactly */ if (*rel != '/') return IS_OUTSIDE_CONE; rel++; return fsmonitor_classify_path_workdir_relative(rel); } enum fsmonitor_path_type fsmonitor_classify_path_absolute( struct fsmonitor_daemon_state *state, const char *path) { const char *rel; enum fsmonitor_path_type t; t = try_classify_workdir_abs_path(state, path); if (state->nr_paths_watching == 1) return t; if (t != IS_OUTSIDE_CONE) return t; if (fspathncmp(path, state->path_gitdir_watch.buf, state->path_gitdir_watch.len)) return IS_OUTSIDE_CONE; rel = path + state->path_gitdir_watch.len; if (!*rel) return IS_GITDIR; /* it is the <gitdir> exactly */ if (*rel != '/') return IS_OUTSIDE_CONE; rel++; return fsmonitor_classify_path_gitdir_relative(rel); } /* * We try to combine small batches at the front of the batch-list to avoid * having a long list. This hopefully makes it a little easier when we want * to truncate and maintain the list. However, we don't want the paths array * to just keep growing and growing with realloc, so we insert an arbitrary * limit. */ #define MY_COMBINE_LIMIT … void fsmonitor_publish(struct fsmonitor_daemon_state *state, struct fsmonitor_batch *batch, const struct string_list *cookie_names) { if (!batch && !cookie_names->nr) return; pthread_mutex_lock(&state->main_lock); if (batch) { struct fsmonitor_batch *head; head = state->current_token_data->batch_head; if (!head) { BUG("token does not have batch"); } else if (head->pinned_time) { /* * We cannot alter the current batch list * because: * * [a] it is being transmitted to at least one * client and the handle_client() thread has a * ref-count, but not a lock on the batch list * starting with this item. * * [b] it has been transmitted in the past to * at least one client such that future * requests are relative to this head batch. * * So, we can only prepend a new batch onto * the front of the list. */ batch->batch_seq_nr = head->batch_seq_nr + 1; batch->next = head; state->current_token_data->batch_head = batch; } else if (!head->batch_seq_nr) { /* * Batch 0 is unpinned. See the note in * `fsmonitor_new_token_data()` about why we * don't need to accumulate these paths. */ fsmonitor_batch__free_list(batch); } else if (head->nr + batch->nr > MY_COMBINE_LIMIT) { /* * The head batch in the list has never been * transmitted to a client, but folding the * contents of the new batch onto it would * exceed our arbitrary limit, so just prepend * the new batch onto the list. */ batch->batch_seq_nr = head->batch_seq_nr + 1; batch->next = head; state->current_token_data->batch_head = batch; } else { /* * We are free to add the paths in the given * batch onto the end of the current head batch. */ fsmonitor_batch__combine(head, batch); fsmonitor_batch__free_list(batch); } } if (cookie_names->nr) with_lock__mark_cookies_seen(state, cookie_names); pthread_mutex_unlock(&state->main_lock); } static void *fsm_health__thread_proc(void *_state) { struct fsmonitor_daemon_state *state = _state; trace2_thread_start("fsm-health"); fsm_health__loop(state); trace2_thread_exit(); return NULL; } static void *fsm_listen__thread_proc(void *_state) { struct fsmonitor_daemon_state *state = _state; trace2_thread_start("fsm-listen"); trace_printf_key(&trace_fsmonitor, "Watching: worktree '%s'", state->path_worktree_watch.buf); if (state->nr_paths_watching > 1) trace_printf_key(&trace_fsmonitor, "Watching: gitdir '%s'", state->path_gitdir_watch.buf); fsm_listen__loop(state); pthread_mutex_lock(&state->main_lock); if (state->current_token_data && state->current_token_data->client_ref_count == 0) fsmonitor_free_token_data(state->current_token_data); state->current_token_data = NULL; pthread_mutex_unlock(&state->main_lock); trace2_thread_exit(); return NULL; } static int fsmonitor_run_daemon_1(struct fsmonitor_daemon_state *state) { struct ipc_server_opts ipc_opts = { .nr_threads = fsmonitor__ipc_threads, /* * We know that there are no other active threads yet, * so we can let the IPC layer temporarily chdir() if * it needs to when creating the server side of the * Unix domain socket. */ .uds_disallow_chdir = 0 }; int health_started = 0; int listener_started = 0; int err = 0; /* * Start the IPC thread pool before the we've started the file * system event listener thread so that we have the IPC handle * before we need it. */ if (ipc_server_run_async(&state->ipc_server_data, state->path_ipc.buf, &ipc_opts, handle_client, state)) return error_errno( _("could not start IPC thread pool on '%s'"), state->path_ipc.buf); /* * Start the fsmonitor listener thread to collect filesystem * events. */ if (pthread_create(&state->listener_thread, NULL, fsm_listen__thread_proc, state)) { ipc_server_stop_async(state->ipc_server_data); err = error(_("could not start fsmonitor listener thread")); goto cleanup; } listener_started = 1; /* * Start the health thread to watch over our process. */ if (pthread_create(&state->health_thread, NULL, fsm_health__thread_proc, state)) { ipc_server_stop_async(state->ipc_server_data); err = error(_("could not start fsmonitor health thread")); goto cleanup; } health_started = 1; /* * The daemon is now fully functional in background threads. * Our primary thread should now just wait while the threads * do all the work. */ cleanup: /* * Wait for the IPC thread pool to shutdown (whether by client * request, from filesystem activity, or an error). */ ipc_server_await(state->ipc_server_data); /* * The fsmonitor listener thread may have received a shutdown * event from the IPC thread pool, but it doesn't hurt to tell * it again. And wait for it to shutdown. */ if (listener_started) { fsm_listen__stop_async(state); pthread_join(state->listener_thread, NULL); } if (health_started) { fsm_health__stop_async(state); pthread_join(state->health_thread, NULL); } if (err) return err; if (state->listen_error_code) return state->listen_error_code; if (state->health_error_code) return state->health_error_code; return 0; } static int fsmonitor_run_daemon(void) { struct fsmonitor_daemon_state state; const char *home; int err; memset(&state, 0, sizeof(state)); hashmap_init(&state.cookies, cookies_cmp, NULL, 0); pthread_mutex_init(&state.main_lock, NULL); pthread_cond_init(&state.cookies_cond, NULL); state.listen_error_code = 0; state.health_error_code = 0; state.current_token_data = fsmonitor_new_token_data(); /* Prepare to (recursively) watch the <worktree-root> directory. */ strbuf_init(&state.path_worktree_watch, 0); strbuf_addstr(&state.path_worktree_watch, absolute_path(repo_get_work_tree(the_repository))); state.nr_paths_watching = 1; strbuf_init(&state.alias.alias, 0); strbuf_init(&state.alias.points_to, 0); if ((err = fsmonitor__get_alias(state.path_worktree_watch.buf, &state.alias))) goto done; /* * We create and delete cookie files somewhere inside the .git * directory to help us keep sync with the file system. If * ".git" is not a directory, then <gitdir> is not inside the * cone of <worktree-root>, so set up a second watch to watch * the <gitdir> so that we get events for the cookie files. */ strbuf_init(&state.path_gitdir_watch, 0); strbuf_addbuf(&state.path_gitdir_watch, &state.path_worktree_watch); strbuf_addstr(&state.path_gitdir_watch, "/.git"); if (!is_directory(state.path_gitdir_watch.buf)) { strbuf_reset(&state.path_gitdir_watch); strbuf_addstr(&state.path_gitdir_watch, absolute_path(repo_get_git_dir(the_repository))); strbuf_strip_suffix(&state.path_gitdir_watch, "/."); state.nr_paths_watching = 2; } /* * We will write filesystem syncing cookie files into * <gitdir>/<fsmonitor-dir>/<cookie-dir>/<pid>-<seq>. * * The extra layers of subdirectories here keep us from * changing the mtime on ".git/" or ".git/foo/" when we create * or delete cookie files. * * There have been problems with some IDEs that do a * non-recursive watch of the ".git/" directory and run a * series of commands any time something happens. * * For example, if we place our cookie files directly in * ".git/" or ".git/foo/" then a `git status` (or similar * command) from the IDE will cause a cookie file to be * created in one of those dirs. This causes the mtime of * those dirs to change. This triggers the IDE's watch * notification. This triggers the IDE to run those commands * again. And the process repeats and the machine never goes * idle. * * Adding the extra layers of subdirectories prevents the * mtime of ".git/" and ".git/foo" from changing when a * cookie file is created. */ strbuf_init(&state.path_cookie_prefix, 0); strbuf_addbuf(&state.path_cookie_prefix, &state.path_gitdir_watch); strbuf_addch(&state.path_cookie_prefix, '/'); strbuf_addstr(&state.path_cookie_prefix, FSMONITOR_DIR); mkdir(state.path_cookie_prefix.buf, 0777); strbuf_addch(&state.path_cookie_prefix, '/'); strbuf_addstr(&state.path_cookie_prefix, FSMONITOR_COOKIE_DIR); mkdir(state.path_cookie_prefix.buf, 0777); strbuf_addch(&state.path_cookie_prefix, '/'); /* * We create a named-pipe or unix domain socket inside of the * ".git" directory. (Well, on Windows, we base our named * pipe in the NPFS on the absolute path of the git * directory.) */ strbuf_init(&state.path_ipc, 0); strbuf_addstr(&state.path_ipc, absolute_path(fsmonitor_ipc__get_path(the_repository))); /* * Confirm that we can create platform-specific resources for the * filesystem listener before we bother starting all the threads. */ if (fsm_listen__ctor(&state)) { err = error(_("could not initialize listener thread")); goto done; } if (fsm_health__ctor(&state)) { err = error(_("could not initialize health thread")); goto done; } /* * CD out of the worktree root directory. * * The common Git startup mechanism causes our CWD to be the * root of the worktree. On Windows, this causes our process * to hold a locked handle on the CWD. This prevents the * worktree from being moved or deleted while the daemon is * running. * * We assume that our FS and IPC listener threads have either * opened all of the handles that they need or will do * everything using absolute paths. */ home = getenv("HOME"); if (home && *home && chdir(home)) die_errno(_("could not cd home '%s'"), home); err = fsmonitor_run_daemon_1(&state); done: pthread_cond_destroy(&state.cookies_cond); pthread_mutex_destroy(&state.main_lock); fsm_listen__dtor(&state); fsm_health__dtor(&state); ipc_server_free(state.ipc_server_data); strbuf_release(&state.path_worktree_watch); strbuf_release(&state.path_gitdir_watch); strbuf_release(&state.path_cookie_prefix); strbuf_release(&state.path_ipc); strbuf_release(&state.alias.alias); strbuf_release(&state.alias.points_to); return err; } static int try_to_run_foreground_daemon(int detach_console MAYBE_UNUSED) { /* * Technically, we don't need to probe for an existing daemon * process, since we could just call `fsmonitor_run_daemon()` * and let it fail if the pipe/socket is busy. * * However, this method gives us a nicer error message for a * common error case. */ if (fsmonitor_ipc__get_state() == IPC_STATE__LISTENING) die(_("fsmonitor--daemon is already running '%s'"), the_repository->worktree); if (fsmonitor__announce_startup) { fprintf(stderr, _("running fsmonitor-daemon in '%s'\n"), the_repository->worktree); fflush(stderr); } #ifdef GIT_WINDOWS_NATIVE if (detach_console) FreeConsole(); #endif return !!fsmonitor_run_daemon(); } static start_bg_wait_cb bg_wait_cb; static int bg_wait_cb(const struct child_process *cp UNUSED, void *cb_data UNUSED) { enum ipc_active_state s = fsmonitor_ipc__get_state(); switch (s) { case IPC_STATE__LISTENING: /* child is "ready" */ return 0; case IPC_STATE__NOT_LISTENING: case IPC_STATE__PATH_NOT_FOUND: /* give child more time */ return 1; default: case IPC_STATE__INVALID_PATH: case IPC_STATE__OTHER_ERROR: /* all the time in world won't help */ return -1; } } static int try_to_start_background_daemon(void) { struct child_process cp = CHILD_PROCESS_INIT; enum start_bg_result sbgr; /* * Before we try to create a background daemon process, see * if a daemon process is already listening. This makes it * easier for us to report an already-listening error to the * console, since our spawn/daemon can only report the success * of creating the background process (and not whether it * immediately exited). */ if (fsmonitor_ipc__get_state() == IPC_STATE__LISTENING) die(_("fsmonitor--daemon is already running '%s'"), the_repository->worktree); if (fsmonitor__announce_startup) { fprintf(stderr, _("starting fsmonitor-daemon in '%s'\n"), the_repository->worktree); fflush(stderr); } cp.git_cmd = 1; strvec_push(&cp.args, "fsmonitor--daemon"); strvec_push(&cp.args, "run"); strvec_push(&cp.args, "--detach"); strvec_pushf(&cp.args, "--ipc-threads=%d", fsmonitor__ipc_threads); cp.no_stdin = 1; cp.no_stdout = 1; cp.no_stderr = 1; sbgr = start_bg_command(&cp, bg_wait_cb, NULL, fsmonitor__start_timeout_sec); switch (sbgr) { case SBGR_READY: return 0; default: case SBGR_ERROR: case SBGR_CB_ERROR: return error(_("daemon failed to start")); case SBGR_TIMEOUT: return error(_("daemon not online yet")); case SBGR_DIED: return error(_("daemon terminated")); } } int cmd_fsmonitor__daemon(int argc, const char **argv, const char *prefix, struct repository *repo UNUSED) { const char *subcmd; enum fsmonitor_reason reason; int detach_console = 0; struct option options[] = { OPT_BOOL(0, "detach", &detach_console, N_("detach from console")), OPT_INTEGER(0, "ipc-threads", &fsmonitor__ipc_threads, N_("use <n> ipc worker threads")), OPT_INTEGER(0, "start-timeout", &fsmonitor__start_timeout_sec, N_("max seconds to wait for background daemon startup")), OPT_END() }; git_config(fsmonitor_config, NULL); argc = parse_options(argc, argv, prefix, options, builtin_fsmonitor__daemon_usage, 0); if (argc != 1) usage_with_options(builtin_fsmonitor__daemon_usage, options); subcmd = argv[0]; if (fsmonitor__ipc_threads < 1) die(_("invalid 'ipc-threads' value (%d)"), fsmonitor__ipc_threads); prepare_repo_settings(the_repository); /* * If the repo is fsmonitor-compatible, explicitly set IPC-mode * (without bothering to load the `core.fsmonitor` config settings). * * If the repo is not compatible, the repo-settings will be set to * incompatible rather than IPC, so we can use one of the __get * routines to detect the discrepancy. */ fsm_settings__set_ipc(the_repository); reason = fsm_settings__get_reason(the_repository); if (reason > FSMONITOR_REASON_OK) die("%s", fsm_settings__get_incompatible_msg(the_repository, reason)); if (!strcmp(subcmd, "start")) return !!try_to_start_background_daemon(); if (!strcmp(subcmd, "run")) return !!try_to_run_foreground_daemon(detach_console); if (!strcmp(subcmd, "stop")) return !!do_as_client__send_stop(); if (!strcmp(subcmd, "status")) return !!do_as_client__status(); die(_("Unhandled subcommand '%s'"), subcmd); } #else int cmd_fsmonitor__daemon(int argc, const char **argv, const char *prefix UNUSED, struct repository *repo UNUSED) { … } #endif
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