Factor out test for subarray version string.
[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 */
33af8567 223 get_resync_start(a);
ed9d66aa 224 a->container->ss->set_array_state(a, 1);
549e9569 225 a->next_state = clear;
2a0bb19e 226 deactivate = 1;
549e9569
NB
227 }
228 if (a->curr_state == write_pending) {
ed9d66aa
NB
229 get_resync_start(a);
230 a->container->ss->set_array_state(a, 0);
549e9569
NB
231 a->next_state = active;
232 }
233 if (a->curr_state == active_idle) {
234 /* Set array to 'clean' FIRST, then
4e5528c6 235 * a->ss->mark_clean(a, ~0ULL);
549e9569
NB
236 * just ignore for now.
237 */
238 }
239
240 if (a->curr_state == readonly) {
241 /* Well, I'm ready to handle things, so
242 * read-auto is OK. FIXME what if we really want
243 * readonly ???
244 */
c052ba30 245 get_resync_start(a);
01f157d7 246 if (a->container->ss->set_array_state(a, 2))
c052ba30 247 a->next_state = read_auto; /* array is clean */
01f157d7
N
248 else
249 a->next_state = active; /* Now active for recovery etc */
549e9569
NB
250 }
251
00e02142
DW
252 if (!deactivate &&
253 a->curr_action == idle &&
549e9569 254 a->prev_action == resync) {
4e5528c6
NB
255 /* A resync has finished. The endpoint is recorded in
256 * 'sync_start'. We don't update the metadata
257 * until the array goes inactive or readonly though.
258 * Just check if we need to fiddle spares.
259 */
77402e51 260 get_resync_start(a);
ed9d66aa 261 a->container->ss->set_array_state(a, 0);
549e9569
NB
262 check_degraded = 1;
263 }
264
00e02142
DW
265 if (!deactivate &&
266 a->curr_action == idle &&
549e9569 267 a->prev_action == recover) {
0a6bdbee
DW
268 /* A recovery has finished. Some disks may be in sync now,
269 * and the array may no longer be degraded
270 */
549e9569 271 for (mdi = a->info.devs ; mdi ; mdi = mdi->next) {
8d45d196
DW
272 a->container->ss->set_disk(a, mdi->disk.raid_disk,
273 mdi->curr_state);
549e9569
NB
274 if (! (mdi->curr_state & DS_INSYNC))
275 check_degraded = 1;
276 }
277 }
278
92967543
DW
279 /* Check for failures and if found:
280 * 1/ Record the failure in the metadata and unblock the device.
281 * FIXME update the kernel to stop notifying on failed drives when
282 * the array is readonly and we have cleared 'blocked'
283 * 2/ Try to remove the device if the array is writable, or can be
284 * made writable.
285 */
549e9569
NB
286 for (mdi = a->info.devs ; mdi ; mdi = mdi->next) {
287 if (mdi->curr_state & DS_FAULTY) {
8d45d196
DW
288 a->container->ss->set_disk(a, mdi->disk.raid_disk,
289 mdi->curr_state);
549e9569 290 check_degraded = 1;
92967543
DW
291 mdi->next_state |= DS_UNBLOCK;
292 if (a->curr_state == read_auto) {
293 a->container->ss->set_array_state(a, 0);
294 a->next_state = active;
295 }
296 if (a->curr_state > readonly)
297 mdi->next_state |= DS_REMOVE;
549e9569
NB
298 }
299 }
300
2e735d19 301 a->container->ss->sync_metadata(a->container);
4e6e574a 302 dprintf("%s: update[%d]: (", __func__, a->info.container_member);
549e9569
NB
303
304 /* Effect state changes in the array */
4e6e574a
DW
305 if (a->next_state != bad_word) {
306 dprintf(" state:%s", array_states[a->next_state]);
549e9569 307 write_attr(array_states[a->next_state], a->info.state_fd);
4e6e574a
DW
308 }
309 if (a->next_action != bad_action) {
549e9569 310 write_attr(sync_actions[a->next_action], a->action_fd);
4e6e574a
DW
311 dprintf(" action:%s", array_states[a->next_state]);
312 }
549e9569 313 for (mdi = a->info.devs; mdi ; mdi = mdi->next) {
92967543
DW
314 if (mdi->next_state & DS_UNBLOCK) {
315 dprintf(" %d:-blocked", mdi->disk.raid_disk);
316 write_attr("-blocked", mdi->state_fd);
317 }
318
319 if ((mdi->next_state & DS_REMOVE) && mdi->state_fd >= 0) {
57632f4a 320 int remove_result;
8d45d196 321
8d45d196
DW
322 /* the kernel may not be able to immediately remove the
323 * disk, we can simply wait until the next event to try
324 * again.
325 */
57632f4a
NB
326 remove_result = write_attr("remove", mdi->state_fd);
327 if (remove_result > 0) {
4e6e574a 328 dprintf(" %d:removed", mdi->disk.raid_disk);
8d45d196
DW
329 close(mdi->state_fd);
330 mdi->state_fd = -1;
331 }
332 }
4e6e574a 333 if (mdi->next_state & DS_INSYNC) {
549e9569 334 write_attr("+in_sync", mdi->state_fd);
4e6e574a
DW
335 dprintf(" %d:+in_sync", mdi->disk.raid_disk);
336 }
549e9569 337 }
4e6e574a 338 dprintf(" )\n");
549e9569
NB
339
340 /* move curr_ to prev_ */
341 a->prev_state = a->curr_state;
342
343 a->prev_action = a->curr_action;
344
345 for (mdi = a->info.devs; mdi ; mdi = mdi->next) {
346 mdi->prev_state = mdi->curr_state;
347 mdi->next_state = 0;
348 }
349
7e1432fb
NB
350 if (check_degraded) {
351 /* manager will do the actual check */
352 a->check_degraded = 1;
353 signal_manager();
354 }
355
2a0bb19e
DW
356 if (deactivate)
357 a->container = NULL;
358
549e9569
NB
359 return 1;
360}
361
0af73f61
DW
362static struct mdinfo *
363find_device(struct active_array *a, int major, int minor)
364{
365 struct mdinfo *mdi;
366
367 for (mdi = a->info.devs ; mdi ; mdi = mdi->next)
368 if (mdi->disk.major == major && mdi->disk.minor == minor)
369 return mdi;
370
371 return NULL;
372}
373
374static void reconcile_failed(struct active_array *aa, struct mdinfo *failed)
375{
376 struct active_array *a;
377 struct mdinfo *victim;
378
379 for (a = aa; a; a = a->next) {
380 if (!a->container)
381 continue;
382 victim = find_device(a, failed->disk.major, failed->disk.minor);
383 if (!victim)
384 continue;
385
386 if (!(victim->curr_state & DS_FAULTY))
387 write_attr("faulty", victim->state_fd);
388 }
389}
390
4e6e574a
DW
391#ifdef DEBUG
392static void dprint_wake_reasons(fd_set *fds)
393{
394 int i;
395 char proc_path[256];
396 char link[256];
397 char *basename;
398 int rv;
399
400 fprintf(stderr, "monitor: wake ( ");
401 for (i = 0; i < FD_SETSIZE; i++) {
402 if (FD_ISSET(i, fds)) {
403 sprintf(proc_path, "/proc/%d/fd/%d",
404 (int) getpid(), i);
405
406 rv = readlink(proc_path, link, sizeof(link) - 1);
407 if (rv < 0) {
408 fprintf(stderr, "%d:unknown ", i);
409 continue;
410 }
411 link[rv] = '\0';
412 basename = strrchr(link, '/');
413 fprintf(stderr, "%d:%s ",
414 i, basename ? ++basename : link);
415 }
416 }
417 fprintf(stderr, ")\n");
418}
419#endif
420
1eb252b8
N
421int monitor_loop_cnt;
422
4d43913c 423static int wait_and_act(struct supertype *container, int nowait)
549e9569
NB
424{
425 fd_set rfds;
426 int maxfd = 0;
e0d6609f 427 struct active_array **aap = &container->arrays;
1ed3f387 428 struct active_array *a, **ap;
549e9569 429 int rv;
0af73f61 430 struct mdinfo *mdi;
549e9569
NB
431
432 FD_ZERO(&rfds);
433
1ed3f387
NB
434 for (ap = aap ; *ap ;) {
435 a = *ap;
436 /* once an array has been deactivated we want to
437 * ask the manager to discard it.
2a0bb19e 438 */
1ed3f387
NB
439 if (!a->container) {
440 if (discard_this) {
441 ap = &(*ap)->next;
442 continue;
443 }
444 *ap = a->next;
445 a->next = NULL;
446 discard_this = a;
447 signal_manager();
2a0bb19e 448 continue;
1ed3f387 449 }
2a0bb19e 450
549e9569
NB
451 add_fd(&rfds, &maxfd, a->info.state_fd);
452 add_fd(&rfds, &maxfd, a->action_fd);
453 for (mdi = a->info.devs ; mdi ; mdi = mdi->next)
454 add_fd(&rfds, &maxfd, mdi->state_fd);
1ed3f387
NB
455
456 ap = &(*ap)->next;
549e9569
NB
457 }
458
e0d6609f
NB
459 if (manager_ready && *aap == NULL) {
460 /* No interesting arrays. Lets see about exiting.
461 * Note that blocking at this point is not a problem
462 * as there are no active arrays, there is nothing that
463 * we need to be ready to do.
464 */
465 int fd = open(container->device_name, O_RDONLY|O_EXCL);
466 if (fd >= 0 || errno != EBUSY) {
467 /* OK, we are safe to leave */
4e6e574a 468 dprintf("no arrays to monitor... exiting\n");
207aac36 469 remove_pidfile(container->devname);
e0d6609f
NB
470 exit_now = 1;
471 signal_manager();
e0d6609f
NB
472 exit(0);
473 }
474 }
475
549e9569 476 if (!nowait) {
4d43913c
NB
477 sigset_t set;
478 sigprocmask(SIG_UNBLOCK, NULL, &set);
479 sigdelset(&set, SIGUSR1);
1eb252b8 480 monitor_loop_cnt |= 1;
4d43913c 481 rv = pselect(maxfd+1, &rfds, NULL, NULL, NULL, &set);
1eb252b8 482 monitor_loop_cnt += 1;
bfa44e2e
NB
483 if (rv == -1 && errno == EINTR)
484 rv = 0;
4e6e574a
DW
485 #ifdef DEBUG
486 dprint_wake_reasons(&rfds);
487 #endif
488
549e9569
NB
489 }
490
2e735d19
NB
491 if (update_queue) {
492 struct metadata_update *this;
493
494 for (this = update_queue; this ; this = this->next)
495 container->ss->process_update(container, this);
496
497 update_queue_handled = update_queue;
498 update_queue = NULL;
499 signal_manager();
500 container->ss->sync_metadata(container);
501 }
502
1ed3f387 503 for (a = *aap; a ; a = a->next) {
2a0bb19e 504 if (a->replaces && !discard_this) {
549e9569
NB
505 struct active_array **ap;
506 for (ap = &a->next; *ap && *ap != a->replaces;
507 ap = & (*ap)->next)
508 ;
509 if (*ap)
510 *ap = (*ap)->next;
511 discard_this = a->replaces;
512 a->replaces = NULL;
6c3fb95c 513 /* FIXME check if device->state_fd need to be cleared?*/
1ed3f387 514 signal_manager();
549e9569 515 }
2a0bb19e
DW
516 if (a->container)
517 rv += read_and_act(a);
549e9569 518 }
0af73f61
DW
519
520 /* propagate failures across container members */
1ed3f387 521 for (a = *aap; a ; a = a->next) {
0af73f61
DW
522 if (!a->container)
523 continue;
524 for (mdi = a->info.devs ; mdi ; mdi = mdi->next)
525 if (mdi->curr_state & DS_FAULTY)
1ed3f387 526 reconcile_failed(*aap, mdi);
0af73f61
DW
527 }
528
549e9569
NB
529 return rv;
530}
531
532void do_monitor(struct supertype *container)
533{
534 int rv;
535 int first = 1;
536 do {
4d43913c 537 rv = wait_and_act(container, first);
549e9569
NB
538 first = 0;
539 } while (rv >= 0);
540}