mdmon: pass symbolic name to mdmon instead of device name.
[thirdparty/mdadm.git] / monitor.c
CommitLineData
a54d5262
DW
1/*
2 * mdmon - monitor external metadata arrays
3 *
4 * Copyright (C) 2007-2008 Neil Brown <neilb@suse.de>
5 * Copyright (C) 2007-2008 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 */
549e9569
NB
20
21#include "mdadm.h"
22#include "mdmon.h"
4d43913c 23#include <sys/syscall.h>
549e9569 24#include <sys/select.h>
1ed3f387 25#include <signal.h>
549e9569
NB
26
27static char *array_states[] = {
28 "clear", "inactive", "suspended", "readonly", "read-auto",
29 "clean", "active", "write-pending", "active-idle", NULL };
30static char *sync_actions[] = {
31 "idle", "reshape", "resync", "recover", "check", "repair", NULL
32};
33
34static int write_attr(char *attr, int fd)
35{
36 return write(fd, attr, strlen(attr));
37}
38
39static void add_fd(fd_set *fds, int *maxfd, int fd)
40{
41 if (fd < 0)
42 return;
43 if (fd > *maxfd)
44 *maxfd = fd;
45 FD_SET(fd, fds);
46}
47
48static int read_attr(char *buf, int len, int fd)
49{
50 int n;
51
52 if (fd < 0) {
53 buf[0] = 0;
54 return 0;
55 }
56 lseek(fd, 0, 0);
57 n = read(fd, buf, len - 1);
58
59 if (n <= 0) {
60 buf[0] = 0;
61 return 0;
62 }
63 buf[n] = 0;
64 if (buf[n-1] == '\n')
65 buf[n-1] = 0;
66 return n;
67}
68
103f2410 69int get_resync_start(struct active_array *a)
c052ba30
DW
70{
71 char buf[30];
72 int n;
73
74 n = read_attr(buf, 30, a->resync_start_fd);
75 if (n <= 0)
76 return n;
77
78 a->resync_start = strtoull(buf, NULL, 10);
79
80 return 1;
81}
549e9569 82
549e9569
NB
83
84static enum array_state read_state(int fd)
85{
86 char buf[20];
87 int n = read_attr(buf, 20, fd);
88
89 if (n <= 0)
90 return bad_word;
1770662b 91 return (enum array_state) sysfs_match_word(buf, array_states);
549e9569
NB
92}
93
94static enum sync_action read_action( int fd)
95{
96 char buf[20];
97 int n = read_attr(buf, 20, fd);
98
99 if (n <= 0)
100 return bad_action;
1770662b 101 return (enum sync_action) sysfs_match_word(buf, sync_actions);
549e9569
NB
102}
103
549e9569
NB
104int read_dev_state(int fd)
105{
106 char buf[60];
107 int n = read_attr(buf, 60, fd);
108 char *cp;
109 int rv = 0;
110
111 if (n <= 0)
112 return 0;
113
114 cp = buf;
115 while (cp) {
1770662b 116 if (sysfs_attr_match(cp, "faulty"))
549e9569 117 rv |= DS_FAULTY;
1770662b 118 if (sysfs_attr_match(cp, "in_sync"))
549e9569 119 rv |= DS_INSYNC;
1770662b 120 if (sysfs_attr_match(cp, "write_mostly"))
549e9569 121 rv |= DS_WRITE_MOSTLY;
1770662b 122 if (sysfs_attr_match(cp, "spare"))
549e9569 123 rv |= DS_SPARE;
1770662b 124 if (sysfs_attr_match(cp, "blocked"))
8d45d196 125 rv |= DS_BLOCKED;
549e9569
NB
126 cp = strchr(cp, ',');
127 if (cp)
128 cp++;
129 }
130 return rv;
131}
132
1ed3f387
NB
133static void signal_manager(void)
134{
4d43913c
NB
135 /* tgkill(getpid(), mon_tid, SIGUSR1); */
136 int pid = getpid();
137 syscall(SYS_tgkill, pid, mgr_tid, SIGUSR1);
1ed3f387 138}
549e9569
NB
139
140/* Monitor a set of active md arrays - all of which share the
141 * same metadata - and respond to events that require
142 * metadata update.
143 *
144 * New arrays are detected by another thread which allocates
145 * required memory and attaches the data structure to our list.
146 *
147 * Events:
148 * Array stops.
149 * This is detected by array_state going to 'clear' or 'inactive'.
150 * while we thought it was active.
151 * Response is to mark metadata as clean and 'clear' the array(??)
152 * write-pending
153 * array_state if 'write-pending'
154 * We mark metadata as 'dirty' then set array to 'active'.
155 * active_idle
156 * Either ignore, or mark clean, then mark metadata as clean.
157 *
158 * device fails
159 * detected by rd-N/state reporting "faulty"
8d45d196
DW
160 * mark device as 'failed' in metadata, let the kernel release the
161 * device by writing '-blocked' to rd/state, and finally write 'remove' to
0af73f61
DW
162 * rd/state. Before a disk can be replaced it must be failed and removed
163 * from all container members, this will be preemptive for the other
164 * arrays... safe?
549e9569
NB
165 *
166 * sync completes
167 * sync_action was 'resync' and becomes 'idle' and resync_start becomes
168 * MaxSector
169 * Notify metadata that sync is complete.
549e9569
NB
170 *
171 * recovery completes
172 * sync_action changes from 'recover' to 'idle'
173 * Check each device state and mark metadata if 'faulty' or 'in_sync'.
549e9569
NB
174 *
175 * deal with resync
c052ba30
DW
176 * This only happens on finding a new array... mdadm will have set
177 * 'resync_start' to the correct value. If 'resync_start' indicates that an
178 * resync needs to occur set the array to the 'active' state rather than the
179 * initial read-auto state.
549e9569
NB
180 *
181 *
182 *
183 * We wait for a change (poll/select) on array_state, sync_action, and
184 * each rd-X/state file.
185 * When we get any change, we check everything. So read each state file,
186 * then decide what to do.
187 *
188 * The core action is to write new metadata to all devices in the array.
189 * This is done at most once on any wakeup.
190 * After that we might:
191 * - update the array_state
192 * - set the role of some devices.
193 * - request a sync_action
194 *
195 */
196
197static int read_and_act(struct active_array *a)
198{
6c3fb95c 199 int check_degraded = 0;
2a0bb19e 200 int deactivate = 0;
549e9569
NB
201 struct mdinfo *mdi;
202
203 a->next_state = bad_word;
204 a->next_action = bad_action;
205
206 a->curr_state = read_state(a->info.state_fd);
207 a->curr_action = read_action(a->action_fd);
208 for (mdi = a->info.devs; mdi ; mdi = mdi->next) {
209 mdi->next_state = 0;
57632f4a 210 if (mdi->state_fd >= 0)
8d45d196 211 mdi->curr_state = read_dev_state(mdi->state_fd);
549e9569
NB
212 }
213
214 if (a->curr_state <= inactive &&
215 a->prev_state > inactive) {
216 /* array has been stopped */
33af8567 217 get_resync_start(a);
ed9d66aa 218 a->container->ss->set_array_state(a, 1);
549e9569 219 a->next_state = clear;
2a0bb19e 220 deactivate = 1;
549e9569
NB
221 }
222 if (a->curr_state == write_pending) {
ed9d66aa
NB
223 get_resync_start(a);
224 a->container->ss->set_array_state(a, 0);
549e9569
NB
225 a->next_state = active;
226 }
227 if (a->curr_state == active_idle) {
d797a062
DW
228 /* Set array to 'clean' FIRST, then mark clean
229 * in the metadata
549e9569 230 */
d797a062
DW
231 a->next_state = clean;
232 }
233 if (a->curr_state == clean) {
234 get_resync_start(a);
235 a->container->ss->set_array_state(a, 1);
549e9569
NB
236 }
237
238 if (a->curr_state == readonly) {
e9dd1598
N
239 /* Well, I'm ready to handle things. If readonly
240 * wasn't requested, transition to read-auto.
549e9569 241 */
e9dd1598
N
242 char buf[64];
243 read_attr(buf, sizeof(buf), a->metadata_fd);
244 if (strncmp(buf, "external:-", 10) == 0) {
245 /* explicit request for readonly array. Leave it alone */
246 ;
247 } else {
248 get_resync_start(a);
249 if (a->container->ss->set_array_state(a, 2))
250 a->next_state = read_auto; /* array is clean */
251 else
252 a->next_state = active; /* Now active for recovery etc */
253 }
549e9569
NB
254 }
255
00e02142
DW
256 if (!deactivate &&
257 a->curr_action == idle &&
549e9569 258 a->prev_action == resync) {
4e5528c6
NB
259 /* A resync has finished. The endpoint is recorded in
260 * 'sync_start'. We don't update the metadata
261 * until the array goes inactive or readonly though.
262 * Just check if we need to fiddle spares.
263 */
77402e51 264 get_resync_start(a);
0c0c44db 265 a->container->ss->set_array_state(a, a->curr_state <= clean);
549e9569
NB
266 check_degraded = 1;
267 }
268
00e02142
DW
269 if (!deactivate &&
270 a->curr_action == idle &&
549e9569 271 a->prev_action == recover) {
0a6bdbee
DW
272 /* A recovery has finished. Some disks may be in sync now,
273 * and the array may no longer be degraded
274 */
549e9569 275 for (mdi = a->info.devs ; mdi ; mdi = mdi->next) {
8d45d196
DW
276 a->container->ss->set_disk(a, mdi->disk.raid_disk,
277 mdi->curr_state);
549e9569
NB
278 if (! (mdi->curr_state & DS_INSYNC))
279 check_degraded = 1;
280 }
281 }
282
92967543
DW
283 /* Check for failures and if found:
284 * 1/ Record the failure in the metadata and unblock the device.
285 * FIXME update the kernel to stop notifying on failed drives when
286 * the array is readonly and we have cleared 'blocked'
287 * 2/ Try to remove the device if the array is writable, or can be
288 * made writable.
289 */
549e9569
NB
290 for (mdi = a->info.devs ; mdi ; mdi = mdi->next) {
291 if (mdi->curr_state & DS_FAULTY) {
8d45d196
DW
292 a->container->ss->set_disk(a, mdi->disk.raid_disk,
293 mdi->curr_state);
549e9569 294 check_degraded = 1;
92967543
DW
295 mdi->next_state |= DS_UNBLOCK;
296 if (a->curr_state == read_auto) {
297 a->container->ss->set_array_state(a, 0);
298 a->next_state = active;
299 }
300 if (a->curr_state > readonly)
301 mdi->next_state |= DS_REMOVE;
549e9569
NB
302 }
303 }
304
2e735d19 305 a->container->ss->sync_metadata(a->container);
4065aa81
DW
306 dprintf("%s(%d): state:%s action:%s next(", __func__, a->info.container_member,
307 array_states[a->curr_state], sync_actions[a->curr_action]);
549e9569
NB
308
309 /* Effect state changes in the array */
4e6e574a
DW
310 if (a->next_state != bad_word) {
311 dprintf(" state:%s", array_states[a->next_state]);
549e9569 312 write_attr(array_states[a->next_state], a->info.state_fd);
4e6e574a
DW
313 }
314 if (a->next_action != bad_action) {
549e9569 315 write_attr(sync_actions[a->next_action], a->action_fd);
4065aa81 316 dprintf(" action:%s", sync_actions[a->next_action]);
4e6e574a 317 }
549e9569 318 for (mdi = a->info.devs; mdi ; mdi = mdi->next) {
92967543
DW
319 if (mdi->next_state & DS_UNBLOCK) {
320 dprintf(" %d:-blocked", mdi->disk.raid_disk);
321 write_attr("-blocked", mdi->state_fd);
322 }
323
324 if ((mdi->next_state & DS_REMOVE) && mdi->state_fd >= 0) {
57632f4a 325 int remove_result;
8d45d196 326
8d45d196
DW
327 /* the kernel may not be able to immediately remove the
328 * disk, we can simply wait until the next event to try
329 * again.
330 */
57632f4a
NB
331 remove_result = write_attr("remove", mdi->state_fd);
332 if (remove_result > 0) {
4e6e574a 333 dprintf(" %d:removed", mdi->disk.raid_disk);
8d45d196
DW
334 close(mdi->state_fd);
335 mdi->state_fd = -1;
336 }
337 }
4e6e574a 338 if (mdi->next_state & DS_INSYNC) {
549e9569 339 write_attr("+in_sync", mdi->state_fd);
4e6e574a
DW
340 dprintf(" %d:+in_sync", mdi->disk.raid_disk);
341 }
549e9569 342 }
4e6e574a 343 dprintf(" )\n");
549e9569
NB
344
345 /* move curr_ to prev_ */
346 a->prev_state = a->curr_state;
347
348 a->prev_action = a->curr_action;
349
350 for (mdi = a->info.devs; mdi ; mdi = mdi->next) {
351 mdi->prev_state = mdi->curr_state;
352 mdi->next_state = 0;
353 }
354
7e1432fb
NB
355 if (check_degraded) {
356 /* manager will do the actual check */
357 a->check_degraded = 1;
358 signal_manager();
359 }
360
2a0bb19e
DW
361 if (deactivate)
362 a->container = NULL;
363
549e9569
NB
364 return 1;
365}
366
0af73f61
DW
367static struct mdinfo *
368find_device(struct active_array *a, int major, int minor)
369{
370 struct mdinfo *mdi;
371
372 for (mdi = a->info.devs ; mdi ; mdi = mdi->next)
373 if (mdi->disk.major == major && mdi->disk.minor == minor)
374 return mdi;
375
376 return NULL;
377}
378
379static void reconcile_failed(struct active_array *aa, struct mdinfo *failed)
380{
381 struct active_array *a;
382 struct mdinfo *victim;
383
384 for (a = aa; a; a = a->next) {
385 if (!a->container)
386 continue;
387 victim = find_device(a, failed->disk.major, failed->disk.minor);
388 if (!victim)
389 continue;
390
391 if (!(victim->curr_state & DS_FAULTY))
392 write_attr("faulty", victim->state_fd);
393 }
394}
395
4e6e574a
DW
396#ifdef DEBUG
397static void dprint_wake_reasons(fd_set *fds)
398{
399 int i;
400 char proc_path[256];
401 char link[256];
402 char *basename;
403 int rv;
404
405 fprintf(stderr, "monitor: wake ( ");
406 for (i = 0; i < FD_SETSIZE; i++) {
407 if (FD_ISSET(i, fds)) {
408 sprintf(proc_path, "/proc/%d/fd/%d",
409 (int) getpid(), i);
410
411 rv = readlink(proc_path, link, sizeof(link) - 1);
412 if (rv < 0) {
413 fprintf(stderr, "%d:unknown ", i);
414 continue;
415 }
416 link[rv] = '\0';
417 basename = strrchr(link, '/');
418 fprintf(stderr, "%d:%s ",
419 i, basename ? ++basename : link);
420 }
421 }
422 fprintf(stderr, ")\n");
423}
424#endif
425
1eb252b8
N
426int monitor_loop_cnt;
427
4d43913c 428static int wait_and_act(struct supertype *container, int nowait)
549e9569
NB
429{
430 fd_set rfds;
431 int maxfd = 0;
e0d6609f 432 struct active_array **aap = &container->arrays;
1ed3f387 433 struct active_array *a, **ap;
549e9569 434 int rv;
0af73f61 435 struct mdinfo *mdi;
6144ed44 436 static unsigned int dirty_arrays = ~0; /* start at some non-zero value */
549e9569
NB
437
438 FD_ZERO(&rfds);
439
1ed3f387
NB
440 for (ap = aap ; *ap ;) {
441 a = *ap;
442 /* once an array has been deactivated we want to
443 * ask the manager to discard it.
2a0bb19e 444 */
1ed3f387
NB
445 if (!a->container) {
446 if (discard_this) {
447 ap = &(*ap)->next;
448 continue;
449 }
450 *ap = a->next;
451 a->next = NULL;
452 discard_this = a;
453 signal_manager();
2a0bb19e 454 continue;
1ed3f387 455 }
2a0bb19e 456
549e9569
NB
457 add_fd(&rfds, &maxfd, a->info.state_fd);
458 add_fd(&rfds, &maxfd, a->action_fd);
459 for (mdi = a->info.devs ; mdi ; mdi = mdi->next)
460 add_fd(&rfds, &maxfd, mdi->state_fd);
1ed3f387
NB
461
462 ap = &(*ap)->next;
549e9569
NB
463 }
464
6144ed44
DW
465 if (manager_ready && (*aap == NULL || (sigterm && !dirty_arrays))) {
466 /* No interesting arrays, or we have been told to
467 * terminate and everything is clean. Lets see about
468 * exiting. Note that blocking at this point is not a
469 * problem as there are no active arrays, there is
470 * nothing that we need to be ready to do.
e0d6609f 471 */
e8a70c89 472 int fd = open_dev_excl(container->devnum);
e0d6609f
NB
473 if (fd >= 0 || errno != EBUSY) {
474 /* OK, we are safe to leave */
6144ed44
DW
475 if (sigterm && !dirty_arrays)
476 dprintf("caught sigterm, all clean... exiting\n");
477 else
478 dprintf("no arrays to monitor... exiting\n");
207aac36 479 remove_pidfile(container->devname);
e0d6609f
NB
480 exit_now = 1;
481 signal_manager();
e0d6609f
NB
482 exit(0);
483 }
484 }
485
549e9569 486 if (!nowait) {
4d43913c
NB
487 sigset_t set;
488 sigprocmask(SIG_UNBLOCK, NULL, &set);
489 sigdelset(&set, SIGUSR1);
1eb252b8 490 monitor_loop_cnt |= 1;
4d43913c 491 rv = pselect(maxfd+1, &rfds, NULL, NULL, NULL, &set);
1eb252b8 492 monitor_loop_cnt += 1;
bfa44e2e
NB
493 if (rv == -1 && errno == EINTR)
494 rv = 0;
4e6e574a
DW
495 #ifdef DEBUG
496 dprint_wake_reasons(&rfds);
497 #endif
498
549e9569
NB
499 }
500
2e735d19
NB
501 if (update_queue) {
502 struct metadata_update *this;
503
504 for (this = update_queue; this ; this = this->next)
505 container->ss->process_update(container, this);
506
507 update_queue_handled = update_queue;
508 update_queue = NULL;
509 signal_manager();
510 container->ss->sync_metadata(container);
511 }
512
3d2c4fc7 513 rv = 0;
6144ed44 514 dirty_arrays = 0;
1ed3f387 515 for (a = *aap; a ; a = a->next) {
6144ed44
DW
516 int is_dirty;
517
2a0bb19e 518 if (a->replaces && !discard_this) {
549e9569
NB
519 struct active_array **ap;
520 for (ap = &a->next; *ap && *ap != a->replaces;
521 ap = & (*ap)->next)
522 ;
523 if (*ap)
524 *ap = (*ap)->next;
525 discard_this = a->replaces;
526 a->replaces = NULL;
6c3fb95c 527 /* FIXME check if device->state_fd need to be cleared?*/
1ed3f387 528 signal_manager();
549e9569 529 }
2a0bb19e
DW
530 if (a->container)
531 rv += read_and_act(a);
6144ed44
DW
532 else
533 continue;
534
535 /* when terminating stop manipulating the array after it is
536 * clean, but make sure read_and_act() is given a chance to
537 * handle 'active_idle'
538 */
539 switch (read_state(a->info.state_fd)) {
540 case active:
541 case active_idle:
542 case suspended:
543 case bad_word:
544 is_dirty = 1;
545 break;
546 default:
547 if (a->curr_state == active_idle)
548 is_dirty = 1;
549 else
550 is_dirty = 0;
551 break;
552 }
553 dirty_arrays += is_dirty;
554 if (sigterm && !is_dirty)
555 a->container = NULL; /* stop touching this array */
549e9569 556 }
0af73f61
DW
557
558 /* propagate failures across container members */
1ed3f387 559 for (a = *aap; a ; a = a->next) {
0af73f61
DW
560 if (!a->container)
561 continue;
562 for (mdi = a->info.devs ; mdi ; mdi = mdi->next)
563 if (mdi->curr_state & DS_FAULTY)
1ed3f387 564 reconcile_failed(*aap, mdi);
0af73f61
DW
565 }
566
549e9569
NB
567 return rv;
568}
569
570void do_monitor(struct supertype *container)
571{
572 int rv;
573 int first = 1;
574 do {
4d43913c 575 rv = wait_and_act(container, first);
549e9569
NB
576 first = 0;
577 } while (rv >= 0);
578}