mdmon: ping will wait for manage_mon to catch up.
[thirdparty/mdadm.git] / monitor.c
CommitLineData
549e9569
NB
1
2#include "mdadm.h"
3#include "mdmon.h"
4d43913c 4#include <sys/syscall.h>
549e9569 5#include <sys/select.h>
1ed3f387 6#include <signal.h>
549e9569
NB
7
8static char *array_states[] = {
9 "clear", "inactive", "suspended", "readonly", "read-auto",
10 "clean", "active", "write-pending", "active-idle", NULL };
11static char *sync_actions[] = {
12 "idle", "reshape", "resync", "recover", "check", "repair", NULL
13};
14
15static int write_attr(char *attr, int fd)
16{
17 return write(fd, attr, strlen(attr));
18}
19
20static void add_fd(fd_set *fds, int *maxfd, int fd)
21{
22 if (fd < 0)
23 return;
24 if (fd > *maxfd)
25 *maxfd = fd;
26 FD_SET(fd, fds);
27}
28
29static int read_attr(char *buf, int len, int fd)
30{
31 int n;
32
33 if (fd < 0) {
34 buf[0] = 0;
35 return 0;
36 }
37 lseek(fd, 0, 0);
38 n = read(fd, buf, len - 1);
39
40 if (n <= 0) {
41 buf[0] = 0;
42 return 0;
43 }
44 buf[n] = 0;
45 if (buf[n-1] == '\n')
46 buf[n-1] = 0;
47 return n;
48}
49
549e9569 50
103f2410 51int get_resync_start(struct active_array *a)
c052ba30
DW
52{
53 char buf[30];
54 int n;
55
56 n = read_attr(buf, 30, a->resync_start_fd);
57 if (n <= 0)
58 return n;
59
60 a->resync_start = strtoull(buf, NULL, 10);
61
62 return 1;
63}
549e9569
NB
64
65static int attr_match(const char *attr, const char *str)
66{
67 /* See if attr, read from a sysfs file, matches
68 * str. They must either be the same, or attr can
69 * have a trailing newline or comma
70 */
71 while (*attr && *str && *attr == *str) {
72 attr++;
73 str++;
74 }
75
76 if (*str || (*attr && *attr != ',' && *attr != '\n'))
77 return 0;
78 return 1;
79}
80
81static int match_word(const char *word, char **list)
82{
83 int n;
84 for (n=0; list[n]; n++)
85 if (attr_match(word, list[n]))
86 break;
87 return n;
88}
89
90static enum array_state read_state(int fd)
91{
92 char buf[20];
93 int n = read_attr(buf, 20, fd);
94
95 if (n <= 0)
96 return bad_word;
97 return (enum array_state) match_word(buf, array_states);
98}
99
100static enum sync_action read_action( int fd)
101{
102 char buf[20];
103 int n = read_attr(buf, 20, fd);
104
105 if (n <= 0)
106 return bad_action;
107 return (enum sync_action) match_word(buf, sync_actions);
108}
109
549e9569
NB
110int read_dev_state(int fd)
111{
112 char buf[60];
113 int n = read_attr(buf, 60, fd);
114 char *cp;
115 int rv = 0;
116
117 if (n <= 0)
118 return 0;
119
120 cp = buf;
121 while (cp) {
8d45d196 122 if (attr_match(cp, "faulty"))
549e9569 123 rv |= DS_FAULTY;
8d45d196 124 if (attr_match(cp, "in_sync"))
549e9569 125 rv |= DS_INSYNC;
8d45d196 126 if (attr_match(cp, "write_mostly"))
549e9569 127 rv |= DS_WRITE_MOSTLY;
8d45d196 128 if (attr_match(cp, "spare"))
549e9569 129 rv |= DS_SPARE;
8d45d196
DW
130 if (attr_match(cp, "blocked"))
131 rv |= DS_BLOCKED;
549e9569
NB
132 cp = strchr(cp, ',');
133 if (cp)
134 cp++;
135 }
136 return rv;
137}
138
1ed3f387
NB
139static void signal_manager(void)
140{
4d43913c
NB
141 /* tgkill(getpid(), mon_tid, SIGUSR1); */
142 int pid = getpid();
143 syscall(SYS_tgkill, pid, mgr_tid, SIGUSR1);
1ed3f387 144}
549e9569
NB
145
146/* Monitor a set of active md arrays - all of which share the
147 * same metadata - and respond to events that require
148 * metadata update.
149 *
150 * New arrays are detected by another thread which allocates
151 * required memory and attaches the data structure to our list.
152 *
153 * Events:
154 * Array stops.
155 * This is detected by array_state going to 'clear' or 'inactive'.
156 * while we thought it was active.
157 * Response is to mark metadata as clean and 'clear' the array(??)
158 * write-pending
159 * array_state if 'write-pending'
160 * We mark metadata as 'dirty' then set array to 'active'.
161 * active_idle
162 * Either ignore, or mark clean, then mark metadata as clean.
163 *
164 * device fails
165 * detected by rd-N/state reporting "faulty"
8d45d196
DW
166 * mark device as 'failed' in metadata, let the kernel release the
167 * device by writing '-blocked' to rd/state, and finally write 'remove' to
0af73f61
DW
168 * rd/state. Before a disk can be replaced it must be failed and removed
169 * from all container members, this will be preemptive for the other
170 * arrays... safe?
549e9569
NB
171 *
172 * sync completes
173 * sync_action was 'resync' and becomes 'idle' and resync_start becomes
174 * MaxSector
175 * Notify metadata that sync is complete.
549e9569
NB
176 *
177 * recovery completes
178 * sync_action changes from 'recover' to 'idle'
179 * Check each device state and mark metadata if 'faulty' or 'in_sync'.
549e9569
NB
180 *
181 * deal with resync
c052ba30
DW
182 * This only happens on finding a new array... mdadm will have set
183 * 'resync_start' to the correct value. If 'resync_start' indicates that an
184 * resync needs to occur set the array to the 'active' state rather than the
185 * initial read-auto state.
549e9569
NB
186 *
187 *
188 *
189 * We wait for a change (poll/select) on array_state, sync_action, and
190 * each rd-X/state file.
191 * When we get any change, we check everything. So read each state file,
192 * then decide what to do.
193 *
194 * The core action is to write new metadata to all devices in the array.
195 * This is done at most once on any wakeup.
196 * After that we might:
197 * - update the array_state
198 * - set the role of some devices.
199 * - request a sync_action
200 *
201 */
202
203static int read_and_act(struct active_array *a)
204{
6c3fb95c 205 int check_degraded = 0;
2a0bb19e 206 int deactivate = 0;
549e9569
NB
207 struct mdinfo *mdi;
208
209 a->next_state = bad_word;
210 a->next_action = bad_action;
211
212 a->curr_state = read_state(a->info.state_fd);
213 a->curr_action = read_action(a->action_fd);
214 for (mdi = a->info.devs; mdi ; mdi = mdi->next) {
215 mdi->next_state = 0;
57632f4a 216 if (mdi->state_fd >= 0)
8d45d196 217 mdi->curr_state = read_dev_state(mdi->state_fd);
549e9569
NB
218 }
219
220 if (a->curr_state <= inactive &&
221 a->prev_state > inactive) {
222 /* array has been stopped */
ed9d66aa 223 a->container->ss->set_array_state(a, 1);
549e9569 224 a->next_state = clear;
2a0bb19e 225 deactivate = 1;
549e9569
NB
226 }
227 if (a->curr_state == write_pending) {
ed9d66aa
NB
228 get_resync_start(a);
229 a->container->ss->set_array_state(a, 0);
549e9569
NB
230 a->next_state = active;
231 }
232 if (a->curr_state == active_idle) {
233 /* Set array to 'clean' FIRST, then
4e5528c6 234 * a->ss->mark_clean(a, ~0ULL);
549e9569
NB
235 * just ignore for now.
236 */
237 }
238
239 if (a->curr_state == readonly) {
240 /* Well, I'm ready to handle things, so
241 * read-auto is OK. FIXME what if we really want
242 * readonly ???
243 */
c052ba30 244 get_resync_start(a);
a35c070b 245// printf("Found a readonly array at %llu\n", a->resync_start);
c052ba30
DW
246 if (a->resync_start == ~0ULL)
247 a->next_state = read_auto; /* array is clean */
248 else {
ed9d66aa 249 a->container->ss->set_array_state(a, 0);
c052ba30
DW
250 a->next_state = active;
251 }
549e9569
NB
252 }
253
00e02142
DW
254 if (!deactivate &&
255 a->curr_action == idle &&
549e9569 256 a->prev_action == resync) {
4e5528c6
NB
257 /* A resync has finished. The endpoint is recorded in
258 * 'sync_start'. We don't update the metadata
259 * until the array goes inactive or readonly though.
260 * Just check if we need to fiddle spares.
261 */
77402e51 262 get_resync_start(a);
ed9d66aa 263 a->container->ss->set_array_state(a, 0);
549e9569
NB
264 check_degraded = 1;
265 }
266
00e02142
DW
267 if (!deactivate &&
268 a->curr_action == idle &&
549e9569 269 a->prev_action == recover) {
0a6bdbee
DW
270 /* A recovery has finished. Some disks may be in sync now,
271 * and the array may no longer be degraded
272 */
549e9569 273 for (mdi = a->info.devs ; mdi ; mdi = mdi->next) {
8d45d196
DW
274 a->container->ss->set_disk(a, mdi->disk.raid_disk,
275 mdi->curr_state);
549e9569
NB
276 if (! (mdi->curr_state & DS_INSYNC))
277 check_degraded = 1;
278 }
0a6bdbee 279 a->container->ss->set_array_state(a, 0);
549e9569
NB
280 }
281
549e9569
NB
282 for (mdi = a->info.devs ; mdi ; mdi = mdi->next) {
283 if (mdi->curr_state & DS_FAULTY) {
8d45d196
DW
284 a->container->ss->set_disk(a, mdi->disk.raid_disk,
285 mdi->curr_state);
549e9569
NB
286 check_degraded = 1;
287 mdi->next_state = DS_REMOVE;
288 }
289 }
290
2e735d19 291 a->container->ss->sync_metadata(a->container);
4e6e574a 292 dprintf("%s: update[%d]: (", __func__, a->info.container_member);
549e9569
NB
293
294 /* Effect state changes in the array */
4e6e574a
DW
295 if (a->next_state != bad_word) {
296 dprintf(" state:%s", array_states[a->next_state]);
549e9569 297 write_attr(array_states[a->next_state], a->info.state_fd);
4e6e574a
DW
298 }
299 if (a->next_action != bad_action) {
549e9569 300 write_attr(sync_actions[a->next_action], a->action_fd);
4e6e574a
DW
301 dprintf(" action:%s", array_states[a->next_state]);
302 }
549e9569 303 for (mdi = a->info.devs; mdi ; mdi = mdi->next) {
57632f4a
NB
304 if (mdi->next_state == DS_REMOVE && mdi->state_fd >= 0) {
305 int remove_result;
8d45d196
DW
306
307 write_attr("-blocked", mdi->state_fd);
308 /* the kernel may not be able to immediately remove the
309 * disk, we can simply wait until the next event to try
310 * again.
311 */
4e6e574a 312 dprintf(" %d:-blocked", mdi->disk.raid_disk);
57632f4a
NB
313 remove_result = write_attr("remove", mdi->state_fd);
314 if (remove_result > 0) {
4e6e574a 315 dprintf(" %d:removed", mdi->disk.raid_disk);
8d45d196
DW
316 close(mdi->state_fd);
317 mdi->state_fd = -1;
318 }
319 }
4e6e574a 320 if (mdi->next_state & DS_INSYNC) {
549e9569 321 write_attr("+in_sync", mdi->state_fd);
4e6e574a
DW
322 dprintf(" %d:+in_sync", mdi->disk.raid_disk);
323 }
549e9569 324 }
4e6e574a 325 dprintf(" )\n");
549e9569
NB
326
327 /* move curr_ to prev_ */
328 a->prev_state = a->curr_state;
329
330 a->prev_action = a->curr_action;
331
332 for (mdi = a->info.devs; mdi ; mdi = mdi->next) {
333 mdi->prev_state = mdi->curr_state;
334 mdi->next_state = 0;
335 }
336
7e1432fb
NB
337 if (check_degraded) {
338 /* manager will do the actual check */
339 a->check_degraded = 1;
340 signal_manager();
341 }
342
2a0bb19e
DW
343 if (deactivate)
344 a->container = NULL;
345
549e9569
NB
346 return 1;
347}
348
0af73f61
DW
349static struct mdinfo *
350find_device(struct active_array *a, int major, int minor)
351{
352 struct mdinfo *mdi;
353
354 for (mdi = a->info.devs ; mdi ; mdi = mdi->next)
355 if (mdi->disk.major == major && mdi->disk.minor == minor)
356 return mdi;
357
358 return NULL;
359}
360
361static void reconcile_failed(struct active_array *aa, struct mdinfo *failed)
362{
363 struct active_array *a;
364 struct mdinfo *victim;
365
366 for (a = aa; a; a = a->next) {
367 if (!a->container)
368 continue;
369 victim = find_device(a, failed->disk.major, failed->disk.minor);
370 if (!victim)
371 continue;
372
373 if (!(victim->curr_state & DS_FAULTY))
374 write_attr("faulty", victim->state_fd);
375 }
376}
377
4e6e574a
DW
378#ifdef DEBUG
379static void dprint_wake_reasons(fd_set *fds)
380{
381 int i;
382 char proc_path[256];
383 char link[256];
384 char *basename;
385 int rv;
386
387 fprintf(stderr, "monitor: wake ( ");
388 for (i = 0; i < FD_SETSIZE; i++) {
389 if (FD_ISSET(i, fds)) {
390 sprintf(proc_path, "/proc/%d/fd/%d",
391 (int) getpid(), i);
392
393 rv = readlink(proc_path, link, sizeof(link) - 1);
394 if (rv < 0) {
395 fprintf(stderr, "%d:unknown ", i);
396 continue;
397 }
398 link[rv] = '\0';
399 basename = strrchr(link, '/');
400 fprintf(stderr, "%d:%s ",
401 i, basename ? ++basename : link);
402 }
403 }
404 fprintf(stderr, ")\n");
405}
406#endif
407
1eb252b8
N
408int monitor_loop_cnt;
409
4d43913c 410static int wait_and_act(struct supertype *container, int nowait)
549e9569
NB
411{
412 fd_set rfds;
413 int maxfd = 0;
e0d6609f 414 struct active_array **aap = &container->arrays;
1ed3f387 415 struct active_array *a, **ap;
549e9569 416 int rv;
0af73f61 417 struct mdinfo *mdi;
549e9569
NB
418
419 FD_ZERO(&rfds);
420
1ed3f387
NB
421 for (ap = aap ; *ap ;) {
422 a = *ap;
423 /* once an array has been deactivated we want to
424 * ask the manager to discard it.
2a0bb19e 425 */
1ed3f387
NB
426 if (!a->container) {
427 if (discard_this) {
428 ap = &(*ap)->next;
429 continue;
430 }
431 *ap = a->next;
432 a->next = NULL;
433 discard_this = a;
434 signal_manager();
2a0bb19e 435 continue;
1ed3f387 436 }
2a0bb19e 437
549e9569
NB
438 add_fd(&rfds, &maxfd, a->info.state_fd);
439 add_fd(&rfds, &maxfd, a->action_fd);
440 for (mdi = a->info.devs ; mdi ; mdi = mdi->next)
441 add_fd(&rfds, &maxfd, mdi->state_fd);
1ed3f387
NB
442
443 ap = &(*ap)->next;
549e9569
NB
444 }
445
e0d6609f
NB
446 if (manager_ready && *aap == NULL) {
447 /* No interesting arrays. Lets see about exiting.
448 * Note that blocking at this point is not a problem
449 * as there are no active arrays, there is nothing that
450 * we need to be ready to do.
451 */
452 int fd = open(container->device_name, O_RDONLY|O_EXCL);
453 if (fd >= 0 || errno != EBUSY) {
454 /* OK, we are safe to leave */
4e6e574a 455 dprintf("no arrays to monitor... exiting\n");
207aac36 456 remove_pidfile(container->devname);
e0d6609f
NB
457 exit_now = 1;
458 signal_manager();
e0d6609f
NB
459 exit(0);
460 }
461 }
462
549e9569 463 if (!nowait) {
4d43913c
NB
464 sigset_t set;
465 sigprocmask(SIG_UNBLOCK, NULL, &set);
466 sigdelset(&set, SIGUSR1);
1eb252b8 467 monitor_loop_cnt |= 1;
4d43913c 468 rv = pselect(maxfd+1, &rfds, NULL, NULL, NULL, &set);
1eb252b8 469 monitor_loop_cnt += 1;
bfa44e2e
NB
470 if (rv == -1 && errno == EINTR)
471 rv = 0;
4e6e574a
DW
472 #ifdef DEBUG
473 dprint_wake_reasons(&rfds);
474 #endif
475
549e9569
NB
476 }
477
2e735d19
NB
478 if (update_queue) {
479 struct metadata_update *this;
480
481 for (this = update_queue; this ; this = this->next)
482 container->ss->process_update(container, this);
483
484 update_queue_handled = update_queue;
485 update_queue = NULL;
486 signal_manager();
487 container->ss->sync_metadata(container);
488 }
489
1ed3f387 490 for (a = *aap; a ; a = a->next) {
2a0bb19e 491 if (a->replaces && !discard_this) {
549e9569
NB
492 struct active_array **ap;
493 for (ap = &a->next; *ap && *ap != a->replaces;
494 ap = & (*ap)->next)
495 ;
496 if (*ap)
497 *ap = (*ap)->next;
498 discard_this = a->replaces;
499 a->replaces = NULL;
6c3fb95c 500 /* FIXME check if device->state_fd need to be cleared?*/
1ed3f387 501 signal_manager();
549e9569 502 }
2a0bb19e
DW
503 if (a->container)
504 rv += read_and_act(a);
549e9569 505 }
0af73f61
DW
506
507 /* propagate failures across container members */
1ed3f387 508 for (a = *aap; a ; a = a->next) {
0af73f61
DW
509 if (!a->container)
510 continue;
511 for (mdi = a->info.devs ; mdi ; mdi = mdi->next)
512 if (mdi->curr_state & DS_FAULTY)
1ed3f387 513 reconcile_failed(*aap, mdi);
0af73f61
DW
514 }
515
549e9569
NB
516 return rv;
517}
518
519void do_monitor(struct supertype *container)
520{
521 int rv;
522 int first = 1;
523 do {
4d43913c 524 rv = wait_and_act(container, first);
549e9569
NB
525 first = 0;
526 } while (rv >= 0);
527}