3 provide API to do non-blocking locks for single or all databases
5 Copyright (C) Amitay Isaacs 2012
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, see <http://www.gnu.org/licenses/>.
21 #include "include/ctdb_private.h"
22 #include "include/ctdb_protocol.h"
25 #include "lib/tdb_wrap/tdb_wrap.h"
26 #include "system/filesys.h"
27 #include "lib/util/dlinklist.h"
30 * Non-blocking Locking API
32 * 1. Create a child process to do blocking locks.
33 * 2. Once the locks are obtained, signal parent process via fd.
34 * 3. Invoke registered callback routine with locking status.
35 * 4. If the child process cannot get locks within certain time,
36 * execute an external script to debug.
38 * ctdb_lock_record() - get a lock on a record
39 * ctdb_lock_db() - get a lock on a DB
40 * ctdb_lock_alldb_prio() - get a lock on all DBs with given priority
41 * ctdb_lock_alldb() - get a lock on all DBs
43 * auto_mark - whether to mark/unmark DBs in before/after callback
53 static const char * const lock_type_str[] = {
62 /* lock_context is the common part for a lock request */
64 struct lock_context *next, *prev;
66 struct ctdb_context *ctdb;
67 struct ctdb_db_context *ctdb_db;
71 struct lock_request *request;
74 struct tevent_fd *tfd;
75 struct tevent_timer *ttimer;
76 struct timeval start_time;
81 /* lock_request is the client specific part for a lock request */
83 struct lock_context *lctx;
84 void (*callback)(void *, bool);
90 * Support samba 3.6.x (and older) versions which do not set db priority.
92 * By default, all databases are set to priority 1. So only when priority
93 * is set to 1, check for databases that need higher priority.
95 static bool later_db(struct ctdb_context *ctdb, const char *name)
97 if (ctdb->tunable.samba3_hack == 0) {
101 if (strstr(name, "brlock") ||
102 strstr(name, "g_lock") ||
103 strstr(name, "notify_onelevel") ||
104 strstr(name, "serverid") ||
105 strstr(name, "xattr_tdb")) {
112 typedef int (*db_handler_t)(struct ctdb_db_context *ctdb_db,
116 static int ctdb_db_iterator(struct ctdb_context *ctdb, uint32_t priority,
117 db_handler_t handler, void *private_data)
119 struct ctdb_db_context *ctdb_db;
122 for (ctdb_db = ctdb->db_list; ctdb_db; ctdb_db = ctdb_db->next) {
123 if (ctdb_db->priority != priority) {
126 if (later_db(ctdb, ctdb_db->db_name)) {
129 ret = handler(ctdb_db, priority, private_data);
135 /* If priority != 1, later_db check is not required and can return */
140 for (ctdb_db = ctdb->db_list; ctdb_db; ctdb_db = ctdb_db->next) {
141 if (!later_db(ctdb, ctdb_db->db_name)) {
144 ret = handler(ctdb_db, priority, private_data);
155 * lock all databases - mark only
157 static int db_lock_mark_handler(struct ctdb_db_context *ctdb_db, uint32_t priority,
160 int tdb_transaction_write_lock_mark(struct tdb_context *);
162 DEBUG(DEBUG_INFO, ("marking locked database %s, priority:%u\n",
163 ctdb_db->db_name, priority));
165 if (tdb_transaction_write_lock_mark(ctdb_db->ltdb->tdb) != 0) {
166 DEBUG(DEBUG_ERR, ("Failed to mark (transaction lock) database %s\n",
171 if (tdb_lockall_mark(ctdb_db->ltdb->tdb) != 0) {
172 DEBUG(DEBUG_ERR, ("Failed to mark (all lock) database %s\n",
180 int ctdb_lockall_mark_prio(struct ctdb_context *ctdb, uint32_t priority)
183 * This function is only used by the main dameon during recovery.
184 * At this stage, the databases have already been locked, by a
185 * dedicated child process. The freeze_mode variable is used to track
186 * whether the actual locks are held by the child process or not.
189 if (ctdb->freeze_mode[priority] != CTDB_FREEZE_FROZEN) {
190 DEBUG(DEBUG_ERR, ("Attempt to mark all databases locked when not frozen\n"));
194 return ctdb_db_iterator(ctdb, priority, db_lock_mark_handler, NULL);
197 static int ctdb_lockall_mark(struct ctdb_context *ctdb)
201 for (priority=1; priority<=NUM_DB_PRIORITIES; priority++) {
202 if (ctdb_db_iterator(ctdb, priority, db_lock_mark_handler, NULL) != 0) {
212 * lock all databases - unmark only
214 static int db_lock_unmark_handler(struct ctdb_db_context *ctdb_db, uint32_t priority,
217 int tdb_transaction_write_lock_unmark(struct tdb_context *);
219 DEBUG(DEBUG_INFO, ("unmarking locked database %s, priority:%u\n",
220 ctdb_db->db_name, priority));
222 if (tdb_transaction_write_lock_unmark(ctdb_db->ltdb->tdb) != 0) {
223 DEBUG(DEBUG_ERR, ("Failed to unmark (transaction lock) database %s\n",
228 if (tdb_lockall_unmark(ctdb_db->ltdb->tdb) != 0) {
229 DEBUG(DEBUG_ERR, ("Failed to unmark (all lock) database %s\n",
237 int ctdb_lockall_unmark_prio(struct ctdb_context *ctdb, uint32_t priority)
240 * This function is only used by the main daemon during recovery.
241 * At this stage, the databases have already been locked, by a
242 * dedicated child process. The freeze_mode variable is used to track
243 * whether the actual locks are held by the child process or not.
246 if (ctdb->freeze_mode[priority] != CTDB_FREEZE_FROZEN) {
247 DEBUG(DEBUG_ERR, ("Attempt to unmark all databases locked when not frozen\n"));
251 return ctdb_db_iterator(ctdb, priority, db_lock_unmark_handler, NULL);
254 static int ctdb_lockall_unmark(struct ctdb_context *ctdb)
258 for (priority=NUM_DB_PRIORITIES; priority>0; priority--) {
259 if (ctdb_db_iterator(ctdb, priority, db_lock_unmark_handler, NULL) != 0) {
268 static void ctdb_lock_schedule(struct ctdb_context *ctdb);
271 * Destructor to kill the child locking process
273 static int ctdb_lock_context_destructor(struct lock_context *lock_ctx)
275 if (lock_ctx->request) {
276 lock_ctx->request->lctx = NULL;
278 if (lock_ctx->child > 0) {
279 ctdb_kill(lock_ctx->ctdb, lock_ctx->child, SIGKILL);
280 if (lock_ctx->type == LOCK_RECORD) {
281 DLIST_REMOVE(lock_ctx->ctdb_db->lock_current, lock_ctx);
283 DLIST_REMOVE(lock_ctx->ctdb->lock_current, lock_ctx);
285 if (lock_ctx->ctdb_db) {
286 lock_ctx->ctdb_db->lock_num_current--;
288 CTDB_DECREMENT_STAT(lock_ctx->ctdb, locks.num_current);
289 if (lock_ctx->ctdb_db) {
290 CTDB_DECREMENT_DB_STAT(lock_ctx->ctdb_db, locks.num_current);
293 if (lock_ctx->type == LOCK_RECORD) {
294 DLIST_REMOVE(lock_ctx->ctdb_db->lock_pending, lock_ctx);
296 DLIST_REMOVE(lock_ctx->ctdb->lock_pending, lock_ctx);
298 CTDB_DECREMENT_STAT(lock_ctx->ctdb, locks.num_pending);
299 if (lock_ctx->ctdb_db) {
300 CTDB_DECREMENT_DB_STAT(lock_ctx->ctdb_db, locks.num_pending);
304 ctdb_lock_schedule(lock_ctx->ctdb);
311 * Destructor to remove lock request
313 static int ctdb_lock_request_destructor(struct lock_request *lock_request)
315 TALLOC_FREE(lock_request->lctx);
320 * Process all the callbacks waiting for lock
322 * If lock has failed, callback is executed with locked=false
324 static void process_callbacks(struct lock_context *lock_ctx, bool locked)
326 struct lock_request *request;
328 if (lock_ctx->auto_mark && locked) {
329 switch (lock_ctx->type) {
331 tdb_chainlock_mark(lock_ctx->ctdb_db->ltdb->tdb, lock_ctx->key);
335 tdb_lockall_mark(lock_ctx->ctdb_db->ltdb->tdb);
338 case LOCK_ALLDB_PRIO:
339 ctdb_lockall_mark_prio(lock_ctx->ctdb, lock_ctx->priority);
343 ctdb_lockall_mark(lock_ctx->ctdb);
348 request = lock_ctx->request;
349 if (lock_ctx->auto_mark) {
350 /* Reset the destructor, so request is not removed from the list */
351 talloc_set_destructor(request, NULL);
353 request->callback(request->private_data, locked);
355 if (lock_ctx->auto_mark && locked) {
356 switch (lock_ctx->type) {
358 tdb_chainlock_unmark(lock_ctx->ctdb_db->ltdb->tdb, lock_ctx->key);
362 tdb_lockall_unmark(lock_ctx->ctdb_db->ltdb->tdb);
365 case LOCK_ALLDB_PRIO:
366 ctdb_lockall_unmark_prio(lock_ctx->ctdb, lock_ctx->priority);
370 ctdb_lockall_unmark(lock_ctx->ctdb);
377 static int lock_bucket_id(double t)
379 double ms = 1.e-3, s = 1;
384 } else if (t < 10*ms) {
386 } else if (t < 100*ms) {
388 } else if (t < 1*s) {
390 } else if (t < 2*s) {
392 } else if (t < 4*s) {
394 } else if (t < 8*s) {
396 } else if (t < 16*s) {
398 } else if (t < 32*s) {
400 } else if (t < 64*s) {
410 * Callback routine when the required locks are obtained.
411 * Called from parent context
413 static void ctdb_lock_handler(struct tevent_context *ev,
414 struct tevent_fd *tfd,
418 struct lock_context *lock_ctx;
419 TALLOC_CTX *tmp_ctx = NULL;
425 lock_ctx = talloc_get_type_abort(private_data, struct lock_context);
427 /* cancel the timeout event */
428 TALLOC_FREE(lock_ctx->ttimer);
430 t = timeval_elapsed(&lock_ctx->start_time);
431 id = lock_bucket_id(t);
433 if (lock_ctx->auto_mark) {
434 tmp_ctx = talloc_new(ev);
435 talloc_steal(tmp_ctx, lock_ctx);
438 /* Read the status from the child process */
439 if (sys_read(lock_ctx->fd[0], &c, 1) != 1) {
442 locked = (c == 0 ? true : false);
445 /* Update statistics */
446 CTDB_INCREMENT_STAT(lock_ctx->ctdb, locks.num_calls);
447 if (lock_ctx->ctdb_db) {
448 CTDB_INCREMENT_DB_STAT(lock_ctx->ctdb_db, locks.num_calls);
452 if (lock_ctx->ctdb_db) {
453 CTDB_INCREMENT_STAT(lock_ctx->ctdb, locks.buckets[id]);
454 CTDB_UPDATE_LATENCY(lock_ctx->ctdb, lock_ctx->ctdb_db,
455 lock_type_str[lock_ctx->type], locks.latency,
456 lock_ctx->start_time);
458 CTDB_UPDATE_DB_LATENCY(lock_ctx->ctdb_db, lock_type_str[lock_ctx->type], locks.latency, t);
459 CTDB_INCREMENT_DB_STAT(lock_ctx->ctdb_db, locks.buckets[id]);
462 CTDB_INCREMENT_STAT(lock_ctx->ctdb, locks.num_failed);
463 if (lock_ctx->ctdb_db) {
464 CTDB_INCREMENT_DB_STAT(lock_ctx->ctdb_db, locks.num_failed);
468 process_callbacks(lock_ctx, locked);
470 if (lock_ctx->auto_mark) {
471 talloc_free(tmp_ctx);
477 * Callback routine when required locks are not obtained within timeout
478 * Called from parent context
480 static void ctdb_lock_timeout_handler(struct tevent_context *ev,
481 struct tevent_timer *ttimer,
482 struct timeval current_time,
485 static const char * debug_locks = NULL;
486 struct lock_context *lock_ctx;
487 struct ctdb_context *ctdb;
490 lock_ctx = talloc_get_type_abort(private_data, struct lock_context);
491 ctdb = lock_ctx->ctdb;
493 /* If a node stopped/banned, don't spam the logs */
494 if (ctdb->nodes[ctdb->pnn]->flags & NODE_FLAGS_INACTIVE) {
495 lock_ctx->ttimer = NULL;
498 if (lock_ctx->ctdb_db) {
500 ("Unable to get %s lock on database %s for %.0lf seconds\n",
501 (lock_ctx->type == LOCK_RECORD ? "RECORD" : "DB"),
502 lock_ctx->ctdb_db->db_name,
503 timeval_elapsed(&lock_ctx->start_time)));
506 ("Unable to get ALLDB locks for %.0lf seconds\n",
507 timeval_elapsed(&lock_ctx->start_time)));
510 /* Fire a child process to find the blocking process. */
511 if (debug_locks == NULL) {
512 debug_locks = getenv("CTDB_DEBUG_LOCKS");
513 if (debug_locks == NULL) {
514 debug_locks = talloc_asprintf(ctdb,
516 getenv("CTDB_BASE"));
519 if (debug_locks != NULL) {
522 execl(debug_locks, debug_locks, NULL);
525 ctdb_track_child(ctdb, pid);
529 " Unable to setup lock debugging - no memory?\n"));
532 /* reset the timeout timer */
533 // talloc_free(lock_ctx->ttimer);
534 lock_ctx->ttimer = tevent_add_timer(ctdb->ev,
536 timeval_current_ofs(10, 0),
537 ctdb_lock_timeout_handler,
542 static int db_count_handler(struct ctdb_db_context *ctdb_db, uint32_t priority,
545 int *count = (int *)private_data;
552 static int db_flags(struct ctdb_db_context *ctdb_db)
554 int tdb_flags = TDB_DEFAULT;
556 #ifdef TDB_MUTEX_LOCKING
557 if (!ctdb_db->persistent && ctdb_db->ctdb->tunable.mutex_enabled) {
558 tdb_flags = (TDB_MUTEX_LOCKING | TDB_CLEAR_IF_FIRST);
569 static int db_name_handler(struct ctdb_db_context *ctdb_db, uint32_t priority,
572 struct db_namelist *list = (struct db_namelist *)private_data;
574 list->names[list->n] = talloc_strdup(list->names, ctdb_db->db_path);
575 list->names[list->n+1] = talloc_asprintf(list->names, "0x%x",
582 static bool lock_helper_args(TALLOC_CTX *mem_ctx,
583 struct lock_context *lock_ctx, int fd,
584 int *argc, const char ***argv)
586 struct ctdb_context *ctdb = lock_ctx->ctdb;
587 const char **args = NULL;
590 struct db_namelist list;
592 switch (lock_ctx->type) {
601 case LOCK_ALLDB_PRIO:
603 ctdb_db_iterator(ctdb, lock_ctx->priority, db_count_handler, &nargs);
608 for (priority=1; priority<NUM_DB_PRIORITIES; priority++) {
609 ctdb_db_iterator(ctdb, priority, db_count_handler, &nargs);
614 /* Add extra argument for null termination */
617 args = talloc_array(mem_ctx, const char *, nargs);
622 args[0] = talloc_asprintf(args, "%d", getpid());
623 args[1] = talloc_asprintf(args, "%d", fd);
625 switch (lock_ctx->type) {
627 args[2] = talloc_strdup(args, "RECORD");
628 args[3] = talloc_strdup(args, lock_ctx->ctdb_db->db_path);
629 args[4] = talloc_asprintf(args, "0x%x",
630 db_flags(lock_ctx->ctdb_db));
631 if (lock_ctx->key.dsize == 0) {
632 args[5] = talloc_strdup(args, "NULL");
634 args[5] = hex_encode_talloc(args, lock_ctx->key.dptr, lock_ctx->key.dsize);
639 args[2] = talloc_strdup(args, "DB");
640 args[3] = talloc_strdup(args, lock_ctx->ctdb_db->db_path);
641 args[4] = talloc_asprintf(args, "0x%x",
642 db_flags(lock_ctx->ctdb_db));
645 case LOCK_ALLDB_PRIO:
646 args[2] = talloc_strdup(args, "DB");
649 ctdb_db_iterator(ctdb, lock_ctx->priority, db_name_handler, &list);
653 args[2] = talloc_strdup(args, "DB");
656 for (priority=1; priority<NUM_DB_PRIORITIES; priority++) {
657 ctdb_db_iterator(ctdb, priority, db_name_handler, &list);
662 /* Make sure last argument is NULL */
663 args[nargs-1] = NULL;
665 for (i=0; i<nargs-1; i++) {
666 if (args[i] == NULL) {
678 * Find a lock request that can be scheduled
680 static struct lock_context *ctdb_find_lock_context(struct ctdb_context *ctdb)
682 struct lock_context *lock_ctx, *next_ctx;
683 struct ctdb_db_context *ctdb_db;
685 /* First check if there are database lock requests */
687 for (lock_ctx = ctdb->lock_pending; lock_ctx != NULL;
688 lock_ctx = next_ctx) {
690 if (lock_ctx->request != NULL) {
691 /* Found a lock context with a request */
695 next_ctx = lock_ctx->next;
697 DEBUG(DEBUG_INFO, ("Removing lock context without lock "
699 DLIST_REMOVE(ctdb->lock_pending, lock_ctx);
700 CTDB_DECREMENT_STAT(ctdb, locks.num_pending);
701 if (lock_ctx->ctdb_db) {
702 CTDB_DECREMENT_DB_STAT(lock_ctx->ctdb_db,
705 talloc_free(lock_ctx);
708 /* Next check database queues */
709 for (ctdb_db = ctdb->db_list; ctdb_db; ctdb_db = ctdb_db->next) {
710 if (ctdb_db->lock_num_current ==
711 ctdb->tunable.lock_processes_per_db) {
715 for (lock_ctx = ctdb_db->lock_pending; lock_ctx != NULL;
716 lock_ctx = next_ctx) {
718 next_ctx = lock_ctx->next;
720 if (lock_ctx->request != NULL) {
724 DEBUG(DEBUG_INFO, ("Removing lock context without "
726 DLIST_REMOVE(ctdb_db->lock_pending, lock_ctx);
727 CTDB_DECREMENT_STAT(ctdb, locks.num_pending);
728 CTDB_DECREMENT_DB_STAT(ctdb_db, locks.num_pending);
729 talloc_free(lock_ctx);
737 * Schedule a new lock child process
738 * Set up callback handler and timeout handler
740 static void ctdb_lock_schedule(struct ctdb_context *ctdb)
742 struct lock_context *lock_ctx;
745 const char *helper = CTDB_HELPER_BINDIR "/ctdb_lock_helper";
746 static const char *prog = NULL;
752 t = getenv("CTDB_LOCK_HELPER");
754 prog = talloc_strdup(ctdb, t);
756 prog = talloc_strdup(ctdb, helper);
758 CTDB_NO_MEMORY_VOID(ctdb, prog);
761 /* Find a lock context with requests */
762 lock_ctx = ctdb_find_lock_context(ctdb);
763 if (lock_ctx == NULL) {
767 lock_ctx->child = -1;
768 ret = pipe(lock_ctx->fd);
770 DEBUG(DEBUG_ERR, ("Failed to create pipe in ctdb_lock_schedule\n"));
774 set_close_on_exec(lock_ctx->fd[0]);
776 /* Create data for child process */
777 tmp_ctx = talloc_new(lock_ctx);
778 if (tmp_ctx == NULL) {
779 DEBUG(DEBUG_ERR, ("Failed to allocate memory for helper args\n"));
780 close(lock_ctx->fd[0]);
781 close(lock_ctx->fd[1]);
785 /* Create arguments for lock helper */
786 if (!lock_helper_args(tmp_ctx, lock_ctx, lock_ctx->fd[1],
788 DEBUG(DEBUG_ERR, ("Failed to create lock helper args\n"));
789 close(lock_ctx->fd[0]);
790 close(lock_ctx->fd[1]);
791 talloc_free(tmp_ctx);
795 if (!ctdb_vfork_with_logging(lock_ctx, ctdb, "lock_helper",
796 prog, argc, (const char **)args,
797 NULL, NULL, &lock_ctx->child)) {
798 DEBUG(DEBUG_ERR, ("Failed to create a child in ctdb_lock_schedule\n"));
799 close(lock_ctx->fd[0]);
800 close(lock_ctx->fd[1]);
801 talloc_free(tmp_ctx);
806 close(lock_ctx->fd[1]);
808 talloc_set_destructor(lock_ctx, ctdb_lock_context_destructor);
810 talloc_free(tmp_ctx);
812 /* Set up timeout handler */
813 lock_ctx->ttimer = tevent_add_timer(ctdb->ev,
815 timeval_current_ofs(10, 0),
816 ctdb_lock_timeout_handler,
818 if (lock_ctx->ttimer == NULL) {
819 ctdb_kill(ctdb, lock_ctx->child, SIGKILL);
820 lock_ctx->child = -1;
821 talloc_set_destructor(lock_ctx, NULL);
822 close(lock_ctx->fd[0]);
826 /* Set up callback */
827 lock_ctx->tfd = tevent_add_fd(ctdb->ev,
833 if (lock_ctx->tfd == NULL) {
834 TALLOC_FREE(lock_ctx->ttimer);
835 ctdb_kill(ctdb, lock_ctx->child, SIGKILL);
836 lock_ctx->child = -1;
837 talloc_set_destructor(lock_ctx, NULL);
838 close(lock_ctx->fd[0]);
841 tevent_fd_set_auto_close(lock_ctx->tfd);
843 /* Move the context from pending to current */
844 if (lock_ctx->type == LOCK_RECORD) {
845 DLIST_REMOVE(lock_ctx->ctdb_db->lock_pending, lock_ctx);
846 DLIST_ADD_END(lock_ctx->ctdb_db->lock_current, lock_ctx, NULL);
848 DLIST_REMOVE(ctdb->lock_pending, lock_ctx);
849 DLIST_ADD_END(ctdb->lock_current, lock_ctx, NULL);
851 CTDB_DECREMENT_STAT(lock_ctx->ctdb, locks.num_pending);
852 CTDB_INCREMENT_STAT(lock_ctx->ctdb, locks.num_current);
853 if (lock_ctx->ctdb_db) {
854 lock_ctx->ctdb_db->lock_num_current++;
855 CTDB_DECREMENT_DB_STAT(lock_ctx->ctdb_db, locks.num_pending);
856 CTDB_INCREMENT_DB_STAT(lock_ctx->ctdb_db, locks.num_current);
862 * Lock record / db depending on type
864 static struct lock_request *ctdb_lock_internal(TALLOC_CTX *mem_ctx,
865 struct ctdb_context *ctdb,
866 struct ctdb_db_context *ctdb_db,
869 void (*callback)(void *, bool),
874 struct lock_context *lock_ctx = NULL;
875 struct lock_request *request;
877 if (callback == NULL) {
878 DEBUG(DEBUG_WARNING, ("No callback function specified, not locking\n"));
882 lock_ctx = talloc_zero(ctdb, struct lock_context);
883 if (lock_ctx == NULL) {
884 DEBUG(DEBUG_ERR, ("Failed to create a new lock context\n"));
888 if ((request = talloc_zero(mem_ctx, struct lock_request)) == NULL) {
889 talloc_free(lock_ctx);
893 lock_ctx->type = type;
894 lock_ctx->ctdb = ctdb;
895 lock_ctx->ctdb_db = ctdb_db;
896 lock_ctx->key.dsize = key.dsize;
898 lock_ctx->key.dptr = talloc_memdup(lock_ctx, key.dptr, key.dsize);
899 if (lock_ctx->key.dptr == NULL) {
900 DEBUG(DEBUG_ERR, (__location__ "Memory allocation error\n"));
901 talloc_free(lock_ctx);
904 lock_ctx->key_hash = ctdb_hash(&key);
906 lock_ctx->key.dptr = NULL;
908 lock_ctx->priority = priority;
909 lock_ctx->auto_mark = auto_mark;
911 lock_ctx->request = request;
912 lock_ctx->child = -1;
914 /* Non-record locks are required by recovery and should be scheduled
915 * immediately, so keep them at the head of the pending queue.
917 if (lock_ctx->type == LOCK_RECORD) {
918 DLIST_ADD_END(ctdb_db->lock_pending, lock_ctx, NULL);
920 DLIST_ADD_END(ctdb->lock_pending, lock_ctx, NULL);
922 CTDB_INCREMENT_STAT(ctdb, locks.num_pending);
924 CTDB_INCREMENT_DB_STAT(ctdb_db, locks.num_pending);
927 /* Start the timer when we activate the context */
928 lock_ctx->start_time = timeval_current();
930 request->lctx = lock_ctx;
931 request->callback = callback;
932 request->private_data = private_data;
934 talloc_set_destructor(request, ctdb_lock_request_destructor);
936 ctdb_lock_schedule(ctdb);
943 * obtain a lock on a record in a database
945 struct lock_request *ctdb_lock_record(TALLOC_CTX *mem_ctx,
946 struct ctdb_db_context *ctdb_db,
949 void (*callback)(void *, bool),
952 return ctdb_lock_internal(mem_ctx,
965 * obtain a lock on a database
967 struct lock_request *ctdb_lock_db(TALLOC_CTX *mem_ctx,
968 struct ctdb_db_context *ctdb_db,
970 void (*callback)(void *, bool),
973 return ctdb_lock_internal(mem_ctx,
986 * obtain locks on all databases of specified priority
988 struct lock_request *ctdb_lock_alldb_prio(TALLOC_CTX *mem_ctx,
989 struct ctdb_context *ctdb,
992 void (*callback)(void *, bool),
995 if (priority < 1 || priority > NUM_DB_PRIORITIES) {
996 DEBUG(DEBUG_ERR, ("Invalid db priority: %u\n", priority));
1000 return ctdb_lock_internal(mem_ctx,
1013 * obtain locks on all databases
1015 struct lock_request *ctdb_lock_alldb(TALLOC_CTX *mem_ctx,
1016 struct ctdb_context *ctdb,
1018 void (*callback)(void *, bool),
1021 return ctdb_lock_internal(mem_ctx,