4 Copyright (C) Andrew Tridgell 2007
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, see <http://www.gnu.org/licenses/>.
20 #include "lib/tevent/tevent.h"
21 #include "lib/tdb/include/tdb.h"
22 #include "system/network.h"
23 #include "system/filesys.h"
24 #include "system/wait.h"
25 #include "../include/ctdb_private.h"
26 #include "lib/util/dlinklist.h"
29 static bool later_db(const char *name)
31 return (strstr(name, "notify") || strstr(name, "serverid"));
37 static int ctdb_lock_all_databases(struct ctdb_context *ctdb, uint32_t priority)
39 struct ctdb_db_context *ctdb_db;
41 /* This double loop is for backward compatibility and deadlock
42 avoidance for old samba versions that not yet support
44 This code shall be removed later
46 for (ctdb_db=ctdb->db_list;ctdb_db;ctdb_db=ctdb_db->next) {
47 if (ctdb_db->priority != priority) {
50 if (later_db(ctdb_db->db_name)) {
53 DEBUG(DEBUG_INFO,("locking database 0x%08x priority:%u %s\n", ctdb_db->db_id, ctdb_db->priority, ctdb_db->db_name));
54 if (tdb_lockall(ctdb_db->ltdb->tdb) != 0) {
55 DEBUG(DEBUG_ERR,(__location__ " Failed to lock database %s\n", ctdb_db->db_name));
59 for (ctdb_db=ctdb->db_list;ctdb_db;ctdb_db=ctdb_db->next) {
60 if (ctdb_db->priority != priority) {
63 if (!later_db(ctdb_db->db_name)) {
66 DEBUG(DEBUG_INFO,("locking database 0x%08x priority:%u %s\n", ctdb_db->db_id, ctdb_db->priority, ctdb_db->db_name));
67 if (tdb_lockall(ctdb_db->ltdb->tdb) != 0) {
68 DEBUG(DEBUG_ERR,(__location__ " Failed to lock database %s\n", ctdb_db->db_name));
76 a list of control requests waiting for a freeze lock child to get
79 struct ctdb_freeze_waiter {
80 struct ctdb_freeze_waiter *next, *prev;
81 struct ctdb_context *ctdb;
82 struct ctdb_req_control *c;
87 /* a handle to a freeze lock child process */
88 struct ctdb_freeze_handle {
89 struct ctdb_context *ctdb;
93 struct ctdb_freeze_waiter *waiters;
97 destroy a freeze handle
99 static int ctdb_freeze_handle_destructor(struct ctdb_freeze_handle *h)
101 struct ctdb_context *ctdb = h->ctdb;
102 struct ctdb_db_context *ctdb_db;
104 DEBUG(DEBUG_ERR,("Release freeze handler for prio %u\n", h->priority));
106 /* cancel any pending transactions */
107 if (ctdb->freeze_transaction_started) {
108 for (ctdb_db=ctdb->db_list;ctdb_db;ctdb_db=ctdb_db->next) {
109 if (ctdb_db->priority != h->priority) {
112 tdb_add_flags(ctdb_db->ltdb->tdb, TDB_NOLOCK);
113 if (tdb_transaction_cancel(ctdb_db->ltdb->tdb) != 0) {
114 DEBUG(DEBUG_ERR,(__location__ " Failed to cancel transaction for db '%s'\n",
117 tdb_remove_flags(ctdb_db->ltdb->tdb, TDB_NOLOCK);
119 ctdb->freeze_transaction_started = false;
122 ctdb->freeze_mode[h->priority] = CTDB_FREEZE_NONE;
123 ctdb->freeze_handles[h->priority] = NULL;
125 kill(h->child, SIGKILL);
130 called when the child writes its status to us
132 static void ctdb_freeze_lock_handler(struct event_context *ev, struct fd_event *fde,
133 uint16_t flags, void *private_data)
135 struct ctdb_freeze_handle *h = talloc_get_type(private_data, struct ctdb_freeze_handle);
137 struct ctdb_freeze_waiter *w;
139 if (h->ctdb->freeze_mode[h->priority] == CTDB_FREEZE_FROZEN) {
140 DEBUG(DEBUG_INFO,("freeze child died - unfreezing\n"));
145 if (read(h->fd, &status, sizeof(status)) != sizeof(status)) {
146 DEBUG(DEBUG_ERR,("read error from freeze lock child\n"));
151 DEBUG(DEBUG_ERR,("Failed to get locks in ctdb_freeze_child\n"));
152 /* we didn't get the locks - destroy the handle */
157 h->ctdb->freeze_mode[h->priority] = CTDB_FREEZE_FROZEN;
159 /* notify the waiters */
160 if (h != h->ctdb->freeze_handles[h->priority]) {
161 DEBUG(DEBUG_ERR,("lockwait finished but h is not linked\n"));
163 while ((w = h->waiters)) {
165 DLIST_REMOVE(h->waiters, w);
171 create a child which gets locks on all the open databases, then calls the callback telling the parent
174 static struct ctdb_freeze_handle *ctdb_freeze_lock(struct ctdb_context *ctdb, uint32_t priority)
176 struct ctdb_freeze_handle *h;
178 struct fd_event *fde;
180 h = talloc_zero(ctdb, struct ctdb_freeze_handle);
181 CTDB_NO_MEMORY_NULL(ctdb, h);
184 h->priority = priority;
186 if (pipe(fd) == -1) {
187 DEBUG(DEBUG_ERR,("Failed to create pipe for ctdb_freeze_lock\n"));
193 if (h->child == -1) {
194 DEBUG(DEBUG_ERR,("Failed to fork child for ctdb_freeze_lock\n"));
205 debug_extra = talloc_asprintf(NULL, "freeze_lock-%u:", priority);
206 ret = ctdb_lock_all_databases(ctdb, priority);
211 ret = write(fd[1], &ret, sizeof(ret));
212 if (ret != sizeof(ret)) {
213 DEBUG(DEBUG_ERR, (__location__ " Failed to write to socket from freeze child. ret:%d errno:%u\n", ret, errno));
219 if (kill(ctdb->ctdbd_pid, 0) != 0) {
220 DEBUG(DEBUG_ERR,("Parent died. Exiting lock wait child\n"));
227 talloc_set_destructor(h, ctdb_freeze_handle_destructor);
230 set_close_on_exec(fd[0]);
235 fde = event_add_fd(ctdb->ev, h, h->fd, EVENT_FD_READ,
236 ctdb_freeze_lock_handler, h);
238 DEBUG(DEBUG_ERR,("Failed to setup fd event for ctdb_freeze_lock\n"));
243 tevent_fd_set_auto_close(fde);
249 destroy a waiter for a freeze mode change
251 static int ctdb_freeze_waiter_destructor(struct ctdb_freeze_waiter *w)
253 ctdb_request_control_reply(w->ctdb, w->c, NULL, w->status, NULL);
258 start the freeze process for a certain priority
260 int ctdb_start_freeze(struct ctdb_context *ctdb, uint32_t priority)
263 DEBUG(DEBUG_ERR,("Freeze priority 0 requested, remapping to priority 1\n"));
267 if ((priority < 1) || (priority > NUM_DB_PRIORITIES)) {
268 DEBUG(DEBUG_ERR,(__location__ " Invalid db priority : %u\n", priority));
272 if (ctdb->freeze_mode[priority] == CTDB_FREEZE_FROZEN) {
273 /* we're already frozen */
277 /* Stop any vacuuming going on: we don't want to wait. */
278 ctdb_stop_vacuuming(ctdb);
280 /* if there isn't a freeze lock child then create one */
281 if (ctdb->freeze_handles[priority] == NULL) {
282 ctdb->freeze_handles[priority] = ctdb_freeze_lock(ctdb, priority);
283 CTDB_NO_MEMORY(ctdb, ctdb->freeze_handles[priority]);
284 ctdb->freeze_mode[priority] = CTDB_FREEZE_PENDING;
293 int32_t ctdb_control_freeze(struct ctdb_context *ctdb, struct ctdb_req_control *c, bool *async_reply)
295 struct ctdb_freeze_waiter *w;
298 priority = (uint32_t)c->srvid;
300 DEBUG(DEBUG_ERR, ("Freeze priority %u\n", priority));
303 DEBUG(DEBUG_ERR,("Freeze priority 0 requested, remapping to priority 1\n"));
307 if ((priority < 1) || (priority > NUM_DB_PRIORITIES)) {
308 DEBUG(DEBUG_ERR,(__location__ " Invalid db priority : %u\n", priority));
312 if (ctdb->freeze_mode[priority] == CTDB_FREEZE_FROZEN) {
313 /* we're already frozen */
317 if (ctdb_start_freeze(ctdb, priority) != 0) {
318 DEBUG(DEBUG_ERR,(__location__ " Failed to start freezing databases with priority %u\n", priority));
322 /* add ourselves to list of waiters */
323 if (ctdb->freeze_handles[priority] == NULL) {
324 DEBUG(DEBUG_ERR,("No freeze lock handle when adding a waiter\n"));
328 w = talloc(ctdb->freeze_handles[priority], struct ctdb_freeze_waiter);
329 CTDB_NO_MEMORY(ctdb, w);
331 w->c = talloc_steal(w, c);
332 w->priority = priority;
334 talloc_set_destructor(w, ctdb_freeze_waiter_destructor);
335 DLIST_ADD(ctdb->freeze_handles[priority]->waiters, w);
337 /* we won't reply till later */
344 block until we are frozen, used during daemon startup
346 bool ctdb_blocking_freeze(struct ctdb_context *ctdb)
350 for (i=1; i<=NUM_DB_PRIORITIES; i++) {
351 if (ctdb_start_freeze(ctdb, i)) {
352 DEBUG(DEBUG_ERR,(__location__ " Failed to freeze databases of prio %u\n", i));
356 /* block until frozen */
357 while (ctdb->freeze_mode[i] == CTDB_FREEZE_PENDING) {
358 event_loop_once(ctdb->ev);
366 static void thaw_priority(struct ctdb_context *ctdb, uint32_t priority)
368 DEBUG(DEBUG_ERR,("Thawing priority %u\n", priority));
370 /* cancel any pending transactions */
371 if (ctdb->freeze_transaction_started) {
372 struct ctdb_db_context *ctdb_db;
374 for (ctdb_db=ctdb->db_list;ctdb_db;ctdb_db=ctdb_db->next) {
375 tdb_add_flags(ctdb_db->ltdb->tdb, TDB_NOLOCK);
376 if (tdb_transaction_cancel(ctdb_db->ltdb->tdb) != 0) {
377 DEBUG(DEBUG_ERR,(__location__ " Failed to cancel transaction for db '%s'\n",
380 tdb_remove_flags(ctdb_db->ltdb->tdb, TDB_NOLOCK);
383 ctdb->freeze_transaction_started = false;
386 /* this hack can be used to get a copy of the databases at the end of a recovery */
387 system("mkdir -p /var/ctdb.saved; /usr/bin/rsync --delete -a /var/ctdb/ /var/ctdb.saved/$$ 2>&1 > /dev/null");
391 /* and this one for local testing */
392 system("mkdir -p test.db.saved; /usr/bin/rsync --delete -a test.db/ test.db.saved/$$ 2>&1 > /dev/null");
395 if (ctdb->freeze_handles[priority] != NULL) {
396 talloc_free(ctdb->freeze_handles[priority]);
397 ctdb->freeze_handles[priority] = NULL;
404 int32_t ctdb_control_thaw(struct ctdb_context *ctdb, uint32_t priority)
407 if (priority > NUM_DB_PRIORITIES) {
408 DEBUG(DEBUG_ERR,(__location__ " Invalid db priority : %u\n", priority));
414 for (i=1;i<=NUM_DB_PRIORITIES; i++) {
415 thaw_priority(ctdb, i);
418 thaw_priority(ctdb, priority);
421 ctdb_call_resend_all(ctdb);
427 start a transaction on all databases - used for recovery
429 int32_t ctdb_control_transaction_start(struct ctdb_context *ctdb, uint32_t id)
431 struct ctdb_db_context *ctdb_db;
434 for (i=1;i<=NUM_DB_PRIORITIES; i++) {
435 if (ctdb->freeze_mode[i] != CTDB_FREEZE_FROZEN) {
436 DEBUG(DEBUG_ERR,(__location__ " Failed transaction_start while not frozen\n"));
441 for (ctdb_db=ctdb->db_list;ctdb_db;ctdb_db=ctdb_db->next) {
444 tdb_add_flags(ctdb_db->ltdb->tdb, TDB_NOLOCK);
446 if (ctdb->freeze_transaction_started) {
447 if (tdb_transaction_cancel(ctdb_db->ltdb->tdb) != 0) {
448 DEBUG(DEBUG_ERR,(__location__ " Failed to cancel transaction for db '%s'\n",
450 /* not a fatal error */
454 ret = tdb_transaction_start(ctdb_db->ltdb->tdb);
456 tdb_remove_flags(ctdb_db->ltdb->tdb, TDB_NOLOCK);
459 DEBUG(DEBUG_ERR,(__location__ " Failed to start transaction for db '%s'\n",
465 ctdb->freeze_transaction_started = true;
466 ctdb->freeze_transaction_id = id;
472 cancel a transaction for all databases - used for recovery
474 int32_t ctdb_control_transaction_cancel(struct ctdb_context *ctdb)
476 struct ctdb_db_context *ctdb_db;
478 DEBUG(DEBUG_ERR,(__location__ " recovery transaction cancelled called\n"));
480 for (ctdb_db=ctdb->db_list;ctdb_db;ctdb_db=ctdb_db->next) {
481 tdb_add_flags(ctdb_db->ltdb->tdb, TDB_NOLOCK);
483 if (tdb_transaction_cancel(ctdb_db->ltdb->tdb) != 0) {
484 DEBUG(DEBUG_ERR,(__location__ " Failed to cancel transaction for db '%s'\n", ctdb_db->db_name));
485 /* not a fatal error */
488 tdb_remove_flags(ctdb_db->ltdb->tdb, TDB_NOLOCK);
491 ctdb->freeze_transaction_started = false;
497 commit transactions on all databases
499 int32_t ctdb_control_transaction_commit(struct ctdb_context *ctdb, uint32_t id)
501 struct ctdb_db_context *ctdb_db;
503 int healthy_nodes = 0;
505 for (i=1;i<=NUM_DB_PRIORITIES; i++) {
506 if (ctdb->freeze_mode[i] != CTDB_FREEZE_FROZEN) {
507 DEBUG(DEBUG_ERR,(__location__ " Failed transaction_start while not frozen\n"));
512 if (!ctdb->freeze_transaction_started) {
513 DEBUG(DEBUG_ERR,(__location__ " transaction not started\n"));
517 if (id != ctdb->freeze_transaction_id) {
518 DEBUG(DEBUG_ERR,(__location__ " incorrect transaction id 0x%x in commit\n", id));
522 DEBUG(DEBUG_DEBUG,(__location__ " num_nodes[%d]\n", ctdb->num_nodes));
523 for (i=0; i < ctdb->num_nodes; i++) {
524 DEBUG(DEBUG_DEBUG,(__location__ " node[%d].flags[0x%X]\n",
525 i, ctdb->nodes[i]->flags));
526 if (ctdb->nodes[i]->flags == 0) {
530 DEBUG(DEBUG_INFO,(__location__ " healthy_nodes[%d]\n", healthy_nodes));
532 for (ctdb_db=ctdb->db_list;ctdb_db;ctdb_db=ctdb_db->next) {
535 tdb_add_flags(ctdb_db->ltdb->tdb, TDB_NOLOCK);
536 ret = tdb_transaction_commit(ctdb_db->ltdb->tdb);
538 DEBUG(DEBUG_ERR,(__location__ " Failed to commit transaction for db '%s'. Cancel all transactions and resetting transaction_started to false.\n",
542 tdb_remove_flags(ctdb_db->ltdb->tdb, TDB_NOLOCK);
544 ret = ctdb_update_persistent_health(ctdb, ctdb_db, NULL, healthy_nodes);
546 DEBUG(DEBUG_CRIT,(__location__ " Failed to update persistent health for db '%s'. "
547 "Cancel all remaining transactions and resetting transaction_started to false.\n",
553 ctdb->freeze_transaction_started = false;
554 ctdb->freeze_transaction_id = 0;
559 /* cancel any pending transactions */
560 for (ctdb_db=ctdb->db_list;ctdb_db;ctdb_db=ctdb_db->next) {
561 tdb_add_flags(ctdb_db->ltdb->tdb, TDB_NOLOCK);
562 if (tdb_transaction_cancel(ctdb_db->ltdb->tdb) != 0) {
563 DEBUG(DEBUG_ERR,(__location__ " Failed to cancel transaction for db '%s'\n",
566 tdb_remove_flags(ctdb_db->ltdb->tdb, TDB_NOLOCK);
568 ctdb->freeze_transaction_started = false;
574 wipe a database - only possible when in a frozen transaction
576 int32_t ctdb_control_wipe_database(struct ctdb_context *ctdb, TDB_DATA indata)
578 struct ctdb_control_wipe_database w = *(struct ctdb_control_wipe_database *)indata.dptr;
579 struct ctdb_db_context *ctdb_db;
581 ctdb_db = find_ctdb_db(ctdb, w.db_id);
583 DEBUG(DEBUG_ERR,(__location__ " Unknown db 0x%x\n", w.db_id));
587 if (ctdb->freeze_mode[ctdb_db->priority] != CTDB_FREEZE_FROZEN) {
588 DEBUG(DEBUG_ERR,(__location__ " Failed transaction_start while not frozen\n"));
592 if (!ctdb->freeze_transaction_started) {
593 DEBUG(DEBUG_ERR,(__location__ " transaction not started\n"));
597 if (w.transaction_id != ctdb->freeze_transaction_id) {
598 DEBUG(DEBUG_ERR,(__location__ " incorrect transaction id 0x%x in commit\n", w.transaction_id));
602 if (tdb_wipe_all(ctdb_db->ltdb->tdb) != 0) {
603 DEBUG(DEBUG_ERR,(__location__ " Failed to wipe database for db '%s'\n",