Store and recover spare_assign info in DDF.
[thirdparty/mdadm.git] / monitor.c
CommitLineData
549e9569
NB
1
2#include "mdadm.h"
3#include "mdmon.h"
4
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
c052ba30
DW
51static int get_resync_start(struct active_array *a)
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{
141 kill(getpid(), SIGUSR1);
142}
549e9569
NB
143
144/* Monitor a set of active md arrays - all of which share the
145 * same metadata - and respond to events that require
146 * metadata update.
147 *
148 * New arrays are detected by another thread which allocates
149 * required memory and attaches the data structure to our list.
150 *
151 * Events:
152 * Array stops.
153 * This is detected by array_state going to 'clear' or 'inactive'.
154 * while we thought it was active.
155 * Response is to mark metadata as clean and 'clear' the array(??)
156 * write-pending
157 * array_state if 'write-pending'
158 * We mark metadata as 'dirty' then set array to 'active'.
159 * active_idle
160 * Either ignore, or mark clean, then mark metadata as clean.
161 *
162 * device fails
163 * detected by rd-N/state reporting "faulty"
8d45d196
DW
164 * mark device as 'failed' in metadata, let the kernel release the
165 * device by writing '-blocked' to rd/state, and finally write 'remove' to
0af73f61
DW
166 * rd/state. Before a disk can be replaced it must be failed and removed
167 * from all container members, this will be preemptive for the other
168 * arrays... safe?
549e9569
NB
169 *
170 * sync completes
171 * sync_action was 'resync' and becomes 'idle' and resync_start becomes
172 * MaxSector
173 * Notify metadata that sync is complete.
174 * "Deal with Degraded"
175 *
176 * recovery completes
177 * sync_action changes from 'recover' to 'idle'
178 * Check each device state and mark metadata if 'faulty' or 'in_sync'.
179 * "Deal with Degraded"
180 *
181 * deal with degraded array
182 * We only do this when first noticing the array is degraded.
183 * This can be when we first see the array, when sync completes or
184 * when recovery completes.
185 *
186 * Check if number of failed devices suggests recovery is needed, and
187 * skip if not.
188 * Ask metadata for a spare device
189 * Add device as not in_sync and give a role
190 * Update metadata.
191 * Start recovery.
192 *
193 * deal with resync
c052ba30
DW
194 * This only happens on finding a new array... mdadm will have set
195 * 'resync_start' to the correct value. If 'resync_start' indicates that an
196 * resync needs to occur set the array to the 'active' state rather than the
197 * initial read-auto state.
549e9569
NB
198 *
199 *
200 *
201 * We wait for a change (poll/select) on array_state, sync_action, and
202 * each rd-X/state file.
203 * When we get any change, we check everything. So read each state file,
204 * then decide what to do.
205 *
206 * The core action is to write new metadata to all devices in the array.
207 * This is done at most once on any wakeup.
208 * After that we might:
209 * - update the array_state
210 * - set the role of some devices.
211 * - request a sync_action
212 *
213 */
214
215static int read_and_act(struct active_array *a)
216{
217 int check_degraded;
2a0bb19e 218 int deactivate = 0;
549e9569
NB
219 struct mdinfo *mdi;
220
221 a->next_state = bad_word;
222 a->next_action = bad_action;
223
224 a->curr_state = read_state(a->info.state_fd);
225 a->curr_action = read_action(a->action_fd);
226 for (mdi = a->info.devs; mdi ; mdi = mdi->next) {
227 mdi->next_state = 0;
8d45d196
DW
228 if (mdi->state_fd > 0)
229 mdi->curr_state = read_dev_state(mdi->state_fd);
549e9569
NB
230 }
231
232 if (a->curr_state <= inactive &&
233 a->prev_state > inactive) {
234 /* array has been stopped */
ed9d66aa 235 a->container->ss->set_array_state(a, 1);
549e9569 236 a->next_state = clear;
2a0bb19e 237 deactivate = 1;
549e9569
NB
238 }
239 if (a->curr_state == write_pending) {
ed9d66aa
NB
240 get_resync_start(a);
241 a->container->ss->set_array_state(a, 0);
549e9569
NB
242 a->next_state = active;
243 }
244 if (a->curr_state == active_idle) {
245 /* Set array to 'clean' FIRST, then
4e5528c6 246 * a->ss->mark_clean(a, ~0ULL);
549e9569
NB
247 * just ignore for now.
248 */
249 }
250
251 if (a->curr_state == readonly) {
252 /* Well, I'm ready to handle things, so
253 * read-auto is OK. FIXME what if we really want
254 * readonly ???
255 */
c052ba30 256 get_resync_start(a);
ed9d66aa 257 printf("Found a readonly array at %llu\n", a->resync_start);
c052ba30
DW
258 if (a->resync_start == ~0ULL)
259 a->next_state = read_auto; /* array is clean */
260 else {
ed9d66aa 261 a->container->ss->set_array_state(a, 0);
c052ba30
DW
262 a->next_state = active;
263 }
549e9569
NB
264 }
265
266 if (a->curr_action == idle &&
267 a->prev_action == resync) {
4e5528c6
NB
268 /* A resync has finished. The endpoint is recorded in
269 * 'sync_start'. We don't update the metadata
270 * until the array goes inactive or readonly though.
271 * Just check if we need to fiddle spares.
272 */
77402e51 273 get_resync_start(a);
ed9d66aa 274 a->container->ss->set_array_state(a, 0);
549e9569
NB
275 check_degraded = 1;
276 }
277
278 if (a->curr_action == idle &&
279 a->prev_action == recover) {
280 for (mdi = a->info.devs ; mdi ; mdi = mdi->next) {
8d45d196
DW
281 a->container->ss->set_disk(a, mdi->disk.raid_disk,
282 mdi->curr_state);
549e9569
NB
283 if (! (mdi->curr_state & DS_INSYNC))
284 check_degraded = 1;
285 }
286 }
287
288
289 for (mdi = a->info.devs ; mdi ; mdi = mdi->next) {
290 if (mdi->curr_state & DS_FAULTY) {
8d45d196
DW
291 a->container->ss->set_disk(a, mdi->disk.raid_disk,
292 mdi->curr_state);
549e9569
NB
293 check_degraded = 1;
294 mdi->next_state = DS_REMOVE;
295 }
296 }
297
298 if (check_degraded) {
299 // FIXME;
300 }
301
302 a->container->ss->sync_metadata(a);
303
304 /* Effect state changes in the array */
305 if (a->next_state != bad_word)
306 write_attr(array_states[a->next_state], a->info.state_fd);
307 if (a->next_action != bad_action)
308 write_attr(sync_actions[a->next_action], a->action_fd);
309 for (mdi = a->info.devs; mdi ; mdi = mdi->next) {
8d45d196
DW
310 if (mdi->next_state == DS_REMOVE && mdi->state_fd > 0) {
311 int remove_err;
312
313 write_attr("-blocked", mdi->state_fd);
314 /* the kernel may not be able to immediately remove the
315 * disk, we can simply wait until the next event to try
316 * again.
317 */
318 remove_err = write_attr("remove", mdi->state_fd);
319 if (!remove_err) {
320 close(mdi->state_fd);
321 mdi->state_fd = -1;
322 }
323 }
549e9569
NB
324 if (mdi->next_state & DS_INSYNC)
325 write_attr("+in_sync", mdi->state_fd);
326 }
327
328 /* move curr_ to prev_ */
329 a->prev_state = a->curr_state;
330
331 a->prev_action = a->curr_action;
332
333 for (mdi = a->info.devs; mdi ; mdi = mdi->next) {
334 mdi->prev_state = mdi->curr_state;
335 mdi->next_state = 0;
336 }
337
2a0bb19e
DW
338 if (deactivate)
339 a->container = NULL;
340
549e9569
NB
341 return 1;
342}
343
0af73f61
DW
344static struct mdinfo *
345find_device(struct active_array *a, int major, int minor)
346{
347 struct mdinfo *mdi;
348
349 for (mdi = a->info.devs ; mdi ; mdi = mdi->next)
350 if (mdi->disk.major == major && mdi->disk.minor == minor)
351 return mdi;
352
353 return NULL;
354}
355
356static void reconcile_failed(struct active_array *aa, struct mdinfo *failed)
357{
358 struct active_array *a;
359 struct mdinfo *victim;
360
361 for (a = aa; a; a = a->next) {
362 if (!a->container)
363 continue;
364 victim = find_device(a, failed->disk.major, failed->disk.minor);
365 if (!victim)
366 continue;
367
368 if (!(victim->curr_state & DS_FAULTY))
369 write_attr("faulty", victim->state_fd);
370 }
371}
372
3e70c845
DW
373static int handle_remove_device(struct md_remove_device_cmd *cmd, struct active_array *aa)
374{
375 struct active_array *a;
376 struct mdinfo *victim;
377 int rv;
378
379 /* scan all arrays for the given device, if ->state_fd is closed (-1)
380 * in all cases then mark the disk as removed in the metadata.
381 * Otherwise reply that it is busy.
382 */
383
384 /* pass1 check that it is not in use anywhere */
385 /* note: we are safe from re-adds as long as the device exists in the
386 * container
387 */
388 for (a = aa; a; a = a->next) {
389 if (!a->container)
390 continue;
391 victim = find_device(a, major(cmd->rdev), minor(cmd->rdev));
392 if (!victim)
393 continue;
394 if (victim->state_fd > 0)
395 return -EBUSY;
396 }
397
398 /* pass2 schedule and process removal per array */
399 for (a = aa; a; a = a->next) {
400 if (!a->container)
401 continue;
402 victim = find_device(a, major(cmd->rdev), minor(cmd->rdev));
403 if (!victim)
404 continue;
405 victim->curr_state |= DS_REMOVE;
406 rv = read_and_act(a);
407 if (rv < 0)
408 return rv;
409 }
410
411 return 0;
412}
413
414static int handle_pipe(struct md_generic_cmd *cmd, struct active_array *aa)
415{
416 switch (cmd->action) {
417 case md_action_ping_monitor:
418 return 0;
419 case md_action_remove_device:
420 return handle_remove_device((void *) cmd, aa);
421 }
422
423 return -1;
424}
425
e0d6609f 426static int wait_and_act(struct supertype *container, int pfd,
1ed3f387 427 int monfd, int nowait)
549e9569
NB
428{
429 fd_set rfds;
430 int maxfd = 0;
e0d6609f 431 struct active_array **aap = &container->arrays;
1ed3f387 432 struct active_array *a, **ap;
549e9569 433 int rv;
0af73f61 434 struct mdinfo *mdi;
549e9569
NB
435
436 FD_ZERO(&rfds);
437
438 add_fd(&rfds, &maxfd, pfd);
1ed3f387
NB
439 for (ap = aap ; *ap ;) {
440 a = *ap;
441 /* once an array has been deactivated we want to
442 * ask the manager to discard it.
2a0bb19e 443 */
1ed3f387
NB
444 if (!a->container) {
445 if (discard_this) {
446 ap = &(*ap)->next;
447 continue;
448 }
449 *ap = a->next;
450 a->next = NULL;
451 discard_this = a;
452 signal_manager();
2a0bb19e 453 continue;
1ed3f387 454 }
2a0bb19e 455
549e9569
NB
456 add_fd(&rfds, &maxfd, a->info.state_fd);
457 add_fd(&rfds, &maxfd, a->action_fd);
458 for (mdi = a->info.devs ; mdi ; mdi = mdi->next)
459 add_fd(&rfds, &maxfd, mdi->state_fd);
1ed3f387
NB
460
461 ap = &(*ap)->next;
549e9569
NB
462 }
463
e0d6609f
NB
464 if (manager_ready && *aap == NULL) {
465 /* No interesting arrays. Lets see about exiting.
466 * Note that blocking at this point is not a problem
467 * as there are no active arrays, there is nothing that
468 * we need to be ready to do.
469 */
470 int fd = open(container->device_name, O_RDONLY|O_EXCL);
471 if (fd >= 0 || errno != EBUSY) {
472 /* OK, we are safe to leave */
473 exit_now = 1;
474 signal_manager();
475 remove_pidfile(container->devname);
476 exit(0);
477 }
478 }
479
549e9569
NB
480 if (!nowait) {
481 rv = select(maxfd+1, &rfds, NULL, NULL, NULL);
482
483 if (rv <= 0)
484 return rv;
485
486 if (FD_ISSET(pfd, &rfds)) {
3e70c845
DW
487 int err = -1;
488
489 if (read(pfd, &err, 1) > 0)
1ed3f387 490 err = handle_pipe(active_cmd, *aap);
3e70c845 491 write(monfd, &err, 1);
549e9569
NB
492 }
493 }
494
1ed3f387 495 for (a = *aap; a ; a = a->next) {
2a0bb19e 496 if (a->replaces && !discard_this) {
549e9569
NB
497 struct active_array **ap;
498 for (ap = &a->next; *ap && *ap != a->replaces;
499 ap = & (*ap)->next)
500 ;
501 if (*ap)
502 *ap = (*ap)->next;
503 discard_this = a->replaces;
504 a->replaces = NULL;
1ed3f387 505 signal_manager();
549e9569 506 }
2a0bb19e
DW
507 if (a->container)
508 rv += read_and_act(a);
549e9569 509 }
0af73f61
DW
510
511 /* propagate failures across container members */
1ed3f387 512 for (a = *aap; a ; a = a->next) {
0af73f61
DW
513 if (!a->container)
514 continue;
515 for (mdi = a->info.devs ; mdi ; mdi = mdi->next)
516 if (mdi->curr_state & DS_FAULTY)
1ed3f387 517 reconcile_failed(*aap, mdi);
0af73f61
DW
518 }
519
549e9569
NB
520 return rv;
521}
522
523void do_monitor(struct supertype *container)
524{
525 int rv;
526 int first = 1;
527 do {
e0d6609f 528 rv = wait_and_act(container, container->mgr_pipe[0],
3e70c845 529 container->mon_pipe[1], first);
549e9569
NB
530 first = 0;
531 } while (rv >= 0);
532}