Consistently print program Name and __func__ in debug messages.
[thirdparty/mdadm.git] / monitor.c
1 /*
2 * mdmon - monitor external metadata arrays
3 *
4 * Copyright (C) 2007-2009 Neil Brown <neilb@suse.de>
5 * Copyright (C) 2007-2009 Intel Corporation
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms and conditions of the GNU General Public License,
9 * version 2, as published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
14 * more details.
15 *
16 * You should have received a copy of the GNU General Public License along with
17 * this program; if not, write to the Free Software Foundation, Inc.,
18 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
19 */
20
21 #include "mdadm.h"
22 #include "mdmon.h"
23 #include <sys/syscall.h>
24 #include <sys/select.h>
25 #include <signal.h>
26
27 static char *array_states[] = {
28 "clear", "inactive", "suspended", "readonly", "read-auto",
29 "clean", "active", "write-pending", "active-idle", NULL };
30 static char *sync_actions[] = {
31 "idle", "reshape", "resync", "recover", "check", "repair", NULL
32 };
33
34 static int write_attr(char *attr, int fd)
35 {
36 return write(fd, attr, strlen(attr));
37 }
38
39 static void add_fd(fd_set *fds, int *maxfd, int fd)
40 {
41 struct stat st;
42 if (fd < 0)
43 return;
44 if (fstat(fd, &st) == -1) {
45 dprintf("Invalid fd %d\n", fd);
46 return;
47 }
48 if (st.st_nlink == 0) {
49 dprintf("fd %d was deleted\n", fd);
50 return;
51 }
52 if (fd > *maxfd)
53 *maxfd = fd;
54 FD_SET(fd, fds);
55 }
56
57 static int read_attr(char *buf, int len, int fd)
58 {
59 int n;
60
61 if (fd < 0) {
62 buf[0] = 0;
63 return 0;
64 }
65 lseek(fd, 0, 0);
66 n = read(fd, buf, len - 1);
67
68 if (n <= 0) {
69 buf[0] = 0;
70 return 0;
71 }
72 buf[n] = 0;
73 if (buf[n-1] == '\n')
74 buf[n-1] = 0;
75 return n;
76 }
77
78 static void read_resync_start(int fd, unsigned long long *v)
79 {
80 char buf[30];
81 int n;
82
83 n = read_attr(buf, 30, fd);
84 if (n <= 0) {
85 dprintf("Failed to read resync_start (%d)\n", fd);
86 return;
87 }
88 if (strncmp(buf, "none", 4) == 0)
89 *v = MaxSector;
90 else
91 *v = strtoull(buf, NULL, 10);
92 }
93
94 static unsigned long long read_sync_completed(int fd)
95 {
96 unsigned long long val;
97 char buf[50];
98 int n;
99 char *ep;
100
101 n = read_attr(buf, 50, fd);
102
103 if (n <= 0)
104 return 0;
105 buf[n] = 0;
106 val = strtoull(buf, &ep, 0);
107 if (ep == buf || (*ep != 0 && *ep != '\n' && *ep != ' '))
108 return 0;
109 return val;
110 }
111
112 static enum array_state read_state(int fd)
113 {
114 char buf[20];
115 int n = read_attr(buf, 20, fd);
116
117 if (n <= 0)
118 return bad_word;
119 return (enum array_state) sysfs_match_word(buf, array_states);
120 }
121
122 static enum sync_action read_action( int fd)
123 {
124 char buf[20];
125 int n = read_attr(buf, 20, fd);
126
127 if (n <= 0)
128 return bad_action;
129 return (enum sync_action) sysfs_match_word(buf, sync_actions);
130 }
131
132 int read_dev_state(int fd)
133 {
134 char buf[60];
135 int n = read_attr(buf, 60, fd);
136 char *cp;
137 int rv = 0;
138
139 if (n <= 0)
140 return 0;
141
142 cp = buf;
143 while (cp) {
144 if (sysfs_attr_match(cp, "faulty"))
145 rv |= DS_FAULTY;
146 if (sysfs_attr_match(cp, "in_sync"))
147 rv |= DS_INSYNC;
148 if (sysfs_attr_match(cp, "write_mostly"))
149 rv |= DS_WRITE_MOSTLY;
150 if (sysfs_attr_match(cp, "spare"))
151 rv |= DS_SPARE;
152 if (sysfs_attr_match(cp, "blocked"))
153 rv |= DS_BLOCKED;
154 cp = strchr(cp, ',');
155 if (cp)
156 cp++;
157 }
158 return rv;
159 }
160
161 static void signal_manager(void)
162 {
163 /* tgkill(getpid(), mon_tid, SIGUSR1); */
164 int pid = getpid();
165 syscall(SYS_tgkill, pid, mgr_tid, SIGUSR1);
166 }
167
168 /* Monitor a set of active md arrays - all of which share the
169 * same metadata - and respond to events that require
170 * metadata update.
171 *
172 * New arrays are detected by another thread which allocates
173 * required memory and attaches the data structure to our list.
174 *
175 * Events:
176 * Array stops.
177 * This is detected by array_state going to 'clear' or 'inactive'.
178 * while we thought it was active.
179 * Response is to mark metadata as clean and 'clear' the array(??)
180 * write-pending
181 * array_state if 'write-pending'
182 * We mark metadata as 'dirty' then set array to 'active'.
183 * active_idle
184 * Either ignore, or mark clean, then mark metadata as clean.
185 *
186 * device fails
187 * detected by rd-N/state reporting "faulty"
188 * mark device as 'failed' in metadata, let the kernel release the
189 * device by writing '-blocked' to rd/state, and finally write 'remove' to
190 * rd/state. Before a disk can be replaced it must be failed and removed
191 * from all container members, this will be preemptive for the other
192 * arrays... safe?
193 *
194 * sync completes
195 * sync_action was 'resync' and becomes 'idle' and resync_start becomes
196 * MaxSector
197 * Notify metadata that sync is complete.
198 *
199 * recovery completes
200 * sync_action changes from 'recover' to 'idle'
201 * Check each device state and mark metadata if 'faulty' or 'in_sync'.
202 *
203 * deal with resync
204 * This only happens on finding a new array... mdadm will have set
205 * 'resync_start' to the correct value. If 'resync_start' indicates that an
206 * resync needs to occur set the array to the 'active' state rather than the
207 * initial read-auto state.
208 *
209 *
210 *
211 * We wait for a change (poll/select) on array_state, sync_action, and
212 * each rd-X/state file.
213 * When we get any change, we check everything. So read each state file,
214 * then decide what to do.
215 *
216 * The core action is to write new metadata to all devices in the array.
217 * This is done at most once on any wakeup.
218 * After that we might:
219 * - update the array_state
220 * - set the role of some devices.
221 * - request a sync_action
222 *
223 */
224
225 #define ARRAY_DIRTY 1
226 #define ARRAY_BUSY 2
227 static int read_and_act(struct active_array *a)
228 {
229 unsigned long long sync_completed;
230 int check_degraded = 0;
231 int check_reshape = 0;
232 int deactivate = 0;
233 struct mdinfo *mdi;
234 int ret = 0;
235 int count = 0;
236 struct timeval tv;
237
238 a->next_state = bad_word;
239 a->next_action = bad_action;
240
241 a->curr_state = read_state(a->info.state_fd);
242 a->curr_action = read_action(a->action_fd);
243 if (a->curr_state != clear)
244 /*
245 * In "clear" state, resync_start may wrongly be set to "0"
246 * when the kernel called md_clean but didn't remove the
247 * sysfs attributes yet
248 */
249 read_resync_start(a->resync_start_fd, &a->info.resync_start);
250 sync_completed = read_sync_completed(a->sync_completed_fd);
251 for (mdi = a->info.devs; mdi ; mdi = mdi->next) {
252 mdi->next_state = 0;
253 mdi->curr_state = 0;
254 if (mdi->state_fd >= 0) {
255 read_resync_start(mdi->recovery_fd,
256 &mdi->recovery_start);
257 mdi->curr_state = read_dev_state(mdi->state_fd);
258 }
259 }
260
261 gettimeofday(&tv, NULL);
262 dprintf("(%d): %ld.%06ld state:%s prev:%s action:%s prev: %s start:%llu\n",
263 a->info.container_member,
264 tv.tv_sec, tv.tv_usec,
265 array_states[a->curr_state],
266 array_states[a->prev_state],
267 sync_actions[a->curr_action],
268 sync_actions[a->prev_action],
269 a->info.resync_start
270 );
271
272 if ((a->curr_state == bad_word || a->curr_state <= inactive) &&
273 a->prev_state > inactive) {
274 /* array has been stopped */
275 a->container->ss->set_array_state(a, 1);
276 a->next_state = clear;
277 deactivate = 1;
278 }
279 if (a->curr_state == write_pending) {
280 a->container->ss->set_array_state(a, 0);
281 a->next_state = active;
282 ret |= ARRAY_DIRTY;
283 }
284 if (a->curr_state == active_idle) {
285 /* Set array to 'clean' FIRST, then mark clean
286 * in the metadata
287 */
288 a->next_state = clean;
289 ret |= ARRAY_DIRTY;
290 }
291 if (a->curr_state == clean) {
292 a->container->ss->set_array_state(a, 1);
293 }
294 if (a->curr_state == active ||
295 a->curr_state == suspended)
296 ret |= ARRAY_DIRTY;
297 if (a->curr_state == readonly) {
298 /* Well, I'm ready to handle things. If readonly
299 * wasn't requested, transition to read-auto.
300 */
301 char buf[64];
302 read_attr(buf, sizeof(buf), a->metadata_fd);
303 if (strncmp(buf, "external:-", 10) == 0) {
304 /* explicit request for readonly array. Leave it alone */
305 ;
306 } else {
307 if (a->container->ss->set_array_state(a, 2))
308 a->next_state = read_auto; /* array is clean */
309 else {
310 a->next_state = active; /* Now active for recovery etc */
311 ret |= ARRAY_DIRTY;
312 }
313 }
314 }
315
316 if (!deactivate &&
317 a->curr_action == idle &&
318 a->prev_action == resync) {
319 /* A resync has finished. The endpoint is recorded in
320 * 'sync_start'. We don't update the metadata
321 * until the array goes inactive or readonly though.
322 * Just check if we need to fiddle spares.
323 */
324 a->container->ss->set_array_state(a, a->curr_state <= clean);
325 check_degraded = 1;
326 }
327
328 if (!deactivate &&
329 a->curr_action == idle &&
330 a->prev_action == recover) {
331 /* A recovery has finished. Some disks may be in sync now,
332 * and the array may no longer be degraded
333 */
334 for (mdi = a->info.devs ; mdi ; mdi = mdi->next) {
335 a->container->ss->set_disk(a, mdi->disk.raid_disk,
336 mdi->curr_state);
337 if (! (mdi->curr_state & DS_INSYNC))
338 check_degraded = 1;
339 count++;
340 }
341 if (count != a->info.array.raid_disks)
342 check_degraded = 1;
343 }
344
345 if (!deactivate &&
346 a->curr_action == reshape &&
347 a->prev_action != reshape)
348 /* reshape was requested by mdadm. Need to see if
349 * new devices have been added. Manager does that
350 * when it sees check_reshape
351 */
352 check_reshape = 1;
353
354 /* Check for failures and if found:
355 * 1/ Record the failure in the metadata and unblock the device.
356 * FIXME update the kernel to stop notifying on failed drives when
357 * the array is readonly and we have cleared 'blocked'
358 * 2/ Try to remove the device if the array is writable, or can be
359 * made writable.
360 */
361 for (mdi = a->info.devs ; mdi ; mdi = mdi->next) {
362 if (mdi->curr_state & DS_FAULTY) {
363 a->container->ss->set_disk(a, mdi->disk.raid_disk,
364 mdi->curr_state);
365 check_degraded = 1;
366 if (mdi->curr_state & DS_BLOCKED)
367 mdi->next_state |= DS_UNBLOCK;
368 if (a->curr_state == read_auto) {
369 a->container->ss->set_array_state(a, 0);
370 a->next_state = active;
371 }
372 if (a->curr_state > readonly)
373 mdi->next_state |= DS_REMOVE;
374 }
375 }
376
377 /* Check for recovery checkpoint notifications. We need to be a
378 * minimum distance away from the last checkpoint to prevent
379 * over checkpointing. Note reshape checkpointing is handled
380 * in the second branch.
381 */
382 if (sync_completed > a->last_checkpoint &&
383 sync_completed - a->last_checkpoint > a->info.component_size >> 4 &&
384 a->curr_action > reshape) {
385 /* A (non-reshape) sync_action has reached a checkpoint.
386 * Record the updated position in the metadata
387 */
388 a->last_checkpoint = sync_completed;
389 a->container->ss->set_array_state(a, a->curr_state <= clean);
390 } else if ((a->curr_action == idle && a->prev_action == reshape) ||
391 (a->curr_action == reshape
392 && sync_completed > a->last_checkpoint) ) {
393 /* Reshape has progressed or completed so we need to
394 * update the array state - and possibly the array size
395 */
396 if (sync_completed != 0)
397 a->last_checkpoint = sync_completed;
398 /* We might need to update last_checkpoint depending on
399 * the reason that reshape finished.
400 * if array reshape is really finished:
401 * set check point to the end, this allows
402 * set_array_state() to finalize reshape in metadata
403 * if reshape if broken: do not set checkpoint to the end
404 * this allows for reshape restart from checkpoint
405 */
406 if ((a->curr_action != reshape) &&
407 (a->prev_action == reshape)) {
408 char buf[40];
409 if ((sysfs_get_str(&a->info, NULL,
410 "reshape_position",
411 buf,
412 sizeof(buf)) >= 0) &&
413 strncmp(buf, "none", 4) == 0)
414 a->last_checkpoint = a->info.component_size;
415 }
416 a->container->ss->set_array_state(a, a->curr_state <= clean);
417 a->last_checkpoint = sync_completed;
418 }
419
420 if (sync_completed > a->last_checkpoint)
421 a->last_checkpoint = sync_completed;
422
423 a->container->ss->sync_metadata(a->container);
424 dprintf("(%d): state:%s action:%s next(", a->info.container_member,
425 array_states[a->curr_state], sync_actions[a->curr_action]);
426
427 /* Effect state changes in the array */
428 if (a->next_state != bad_word) {
429 dprintf_cont(" state:%s", array_states[a->next_state]);
430 write_attr(array_states[a->next_state], a->info.state_fd);
431 }
432 if (a->next_action != bad_action) {
433 write_attr(sync_actions[a->next_action], a->action_fd);
434 dprintf_cont(" action:%s", sync_actions[a->next_action]);
435 }
436 for (mdi = a->info.devs; mdi ; mdi = mdi->next) {
437 if (mdi->next_state & DS_UNBLOCK) {
438 dprintf_cont(" %d:-blocked", mdi->disk.raid_disk);
439 write_attr("-blocked", mdi->state_fd);
440 }
441
442 if ((mdi->next_state & DS_REMOVE) && mdi->state_fd >= 0) {
443 int remove_result;
444
445 /* The kernel may not be able to immediately remove the
446 * disk. In that case we wait a little while and
447 * try again.
448 */
449 remove_result = write_attr("remove", mdi->state_fd);
450 if (remove_result > 0) {
451 dprintf_cont(" %d:removed", mdi->disk.raid_disk);
452 close(mdi->state_fd);
453 close(mdi->recovery_fd);
454 mdi->state_fd = -1;
455 } else
456 ret |= ARRAY_BUSY;
457 }
458 if (mdi->next_state & DS_INSYNC) {
459 write_attr("+in_sync", mdi->state_fd);
460 dprintf_cont(" %d:+in_sync", mdi->disk.raid_disk);
461 }
462 }
463 dprintf_cont(" )\n");
464
465 /* move curr_ to prev_ */
466 a->prev_state = a->curr_state;
467
468 a->prev_action = a->curr_action;
469
470 for (mdi = a->info.devs; mdi ; mdi = mdi->next) {
471 mdi->prev_state = mdi->curr_state;
472 mdi->next_state = 0;
473 }
474
475 if (check_degraded || check_reshape) {
476 /* manager will do the actual check */
477 if (check_degraded)
478 a->check_degraded = 1;
479 if (check_reshape)
480 a->check_reshape = 1;
481 signal_manager();
482 }
483
484 if (deactivate)
485 a->container = NULL;
486
487 return ret;
488 }
489
490 static struct mdinfo *
491 find_device(struct active_array *a, int major, int minor)
492 {
493 struct mdinfo *mdi;
494
495 for (mdi = a->info.devs ; mdi ; mdi = mdi->next)
496 if (mdi->disk.major == major && mdi->disk.minor == minor)
497 return mdi;
498
499 return NULL;
500 }
501
502 static void reconcile_failed(struct active_array *aa, struct mdinfo *failed)
503 {
504 struct active_array *a;
505 struct mdinfo *victim;
506
507 for (a = aa; a; a = a->next) {
508 if (!a->container || a->to_remove)
509 continue;
510 victim = find_device(a, failed->disk.major, failed->disk.minor);
511 if (!victim)
512 continue;
513
514 if (!(victim->curr_state & DS_FAULTY))
515 write_attr("faulty", victim->state_fd);
516 }
517 }
518
519 #ifdef DEBUG
520 static void dprint_wake_reasons(fd_set *fds)
521 {
522 int i;
523 char proc_path[256];
524 char link[256];
525 char *basename;
526 int rv;
527
528 fprintf(stderr, "monitor: wake ( ");
529 for (i = 0; i < FD_SETSIZE; i++) {
530 if (FD_ISSET(i, fds)) {
531 sprintf(proc_path, "/proc/%d/fd/%d",
532 (int) getpid(), i);
533
534 rv = readlink(proc_path, link, sizeof(link) - 1);
535 if (rv < 0) {
536 fprintf(stderr, "%d:unknown ", i);
537 continue;
538 }
539 link[rv] = '\0';
540 basename = strrchr(link, '/');
541 fprintf(stderr, "%d:%s ",
542 i, basename ? ++basename : link);
543 }
544 }
545 fprintf(stderr, ")\n");
546 }
547 #endif
548
549 int monitor_loop_cnt;
550
551 static int wait_and_act(struct supertype *container, int nowait)
552 {
553 fd_set rfds;
554 int maxfd = 0;
555 struct active_array **aap = &container->arrays;
556 struct active_array *a, **ap;
557 int rv;
558 struct mdinfo *mdi;
559 static unsigned int dirty_arrays = ~0; /* start at some non-zero value */
560
561 FD_ZERO(&rfds);
562
563 for (ap = aap ; *ap ;) {
564 a = *ap;
565 /* once an array has been deactivated we want to
566 * ask the manager to discard it.
567 */
568 if (!a->container || a->to_remove) {
569 if (discard_this) {
570 ap = &(*ap)->next;
571 continue;
572 }
573 *ap = a->next;
574 a->next = NULL;
575 discard_this = a;
576 signal_manager();
577 continue;
578 }
579
580 add_fd(&rfds, &maxfd, a->info.state_fd);
581 add_fd(&rfds, &maxfd, a->action_fd);
582 add_fd(&rfds, &maxfd, a->sync_completed_fd);
583 for (mdi = a->info.devs ; mdi ; mdi = mdi->next)
584 add_fd(&rfds, &maxfd, mdi->state_fd);
585
586 ap = &(*ap)->next;
587 }
588
589 if (manager_ready && (*aap == NULL || (sigterm && !dirty_arrays))) {
590 /* No interesting arrays, or we have been told to
591 * terminate and everything is clean. Lets see about
592 * exiting. Note that blocking at this point is not a
593 * problem as there are no active arrays, there is
594 * nothing that we need to be ready to do.
595 */
596 int fd;
597 if (sigterm)
598 fd = open_dev_excl(container->devnm);
599 else
600 fd = open_dev_flags(container->devnm, O_RDONLY|O_EXCL);
601 if (fd >= 0 || errno != EBUSY) {
602 /* OK, we are safe to leave */
603 if (sigterm && !dirty_arrays)
604 dprintf("caught sigterm, all clean... exiting\n");
605 else
606 dprintf("no arrays to monitor... exiting\n");
607 if (!sigterm)
608 /* On SIGTERM, someone (the take-over mdmon) will
609 * clean up
610 */
611 remove_pidfile(container->devnm);
612 exit_now = 1;
613 signal_manager();
614 close(fd);
615 exit(0);
616 }
617 }
618
619 if (!nowait) {
620 sigset_t set;
621 struct timespec ts;
622 ts.tv_sec = 24*3600;
623 ts.tv_nsec = 0;
624 if (*aap == NULL || container->retry_soon) {
625 /* just waiting to get O_EXCL access */
626 ts.tv_sec = 0;
627 ts.tv_nsec = 20000000ULL;
628 }
629 sigprocmask(SIG_UNBLOCK, NULL, &set);
630 sigdelset(&set, SIGUSR1);
631 monitor_loop_cnt |= 1;
632 rv = pselect(maxfd+1, NULL, NULL, &rfds, &ts, &set);
633 monitor_loop_cnt += 1;
634 if (rv == -1) {
635 if (errno == EINTR) {
636 rv = 0;
637 dprintf("monitor: caught signal\n");
638 } else
639 dprintf("monitor: error %d in pselect\n",
640 errno);
641 }
642 #ifdef DEBUG
643 else
644 dprint_wake_reasons(&rfds);
645 #endif
646 container->retry_soon = 0;
647 }
648
649 if (update_queue) {
650 struct metadata_update *this;
651
652 for (this = update_queue; this ; this = this->next)
653 container->ss->process_update(container, this);
654
655 update_queue_handled = update_queue;
656 update_queue = NULL;
657 signal_manager();
658 container->ss->sync_metadata(container);
659 }
660
661 rv = 0;
662 dirty_arrays = 0;
663 for (a = *aap; a ; a = a->next) {
664
665 if (a->replaces && !discard_this) {
666 struct active_array **ap;
667 for (ap = &a->next; *ap && *ap != a->replaces;
668 ap = & (*ap)->next)
669 ;
670 if (*ap)
671 *ap = (*ap)->next;
672 discard_this = a->replaces;
673 a->replaces = NULL;
674 /* FIXME check if device->state_fd need to be cleared?*/
675 signal_manager();
676 }
677 if (a->container && !a->to_remove) {
678 int ret = read_and_act(a);
679 rv |= 1;
680 dirty_arrays += !!(ret & ARRAY_DIRTY);
681 /* when terminating stop manipulating the array after it
682 * is clean, but make sure read_and_act() is given a
683 * chance to handle 'active_idle'
684 */
685 if (sigterm && !(ret & ARRAY_DIRTY))
686 a->container = NULL; /* stop touching this array */
687 if (ret & ARRAY_BUSY)
688 container->retry_soon = 1;
689 }
690 }
691
692 /* propagate failures across container members */
693 for (a = *aap; a ; a = a->next) {
694 if (!a->container || a->to_remove)
695 continue;
696 for (mdi = a->info.devs ; mdi ; mdi = mdi->next)
697 if (mdi->curr_state & DS_FAULTY)
698 reconcile_failed(*aap, mdi);
699 }
700
701 return rv;
702 }
703
704 void do_monitor(struct supertype *container)
705 {
706 int rv;
707 int first = 1;
708 do {
709 rv = wait_and_act(container, first);
710 first = 0;
711 } while (rv >= 0);
712 }