Set status of devices 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>
6
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
50static int get_sync_pos(struct active_array *a)
51{
52 char buf[30];
53 int n;
54
55 n = read_attr(buf, 30, a->sync_pos_fd);
56 if (n <= 0)
57 return n;
58
59 if (strncmp(buf, "max", 3) == 0) {
60 a->sync_pos = ~(unsigned long long)0;
61 return 1;
62 }
63 a->sync_pos = strtoull(buf, NULL, 10);
64 return 1;
65}
66
c052ba30
DW
67static int get_resync_start(struct active_array *a)
68{
69 char buf[30];
70 int n;
71
72 n = read_attr(buf, 30, a->resync_start_fd);
73 if (n <= 0)
74 return n;
75
76 a->resync_start = strtoull(buf, NULL, 10);
77
78 return 1;
79}
549e9569
NB
80
81static int attr_match(const char *attr, const char *str)
82{
83 /* See if attr, read from a sysfs file, matches
84 * str. They must either be the same, or attr can
85 * have a trailing newline or comma
86 */
87 while (*attr && *str && *attr == *str) {
88 attr++;
89 str++;
90 }
91
92 if (*str || (*attr && *attr != ',' && *attr != '\n'))
93 return 0;
94 return 1;
95}
96
97static int match_word(const char *word, char **list)
98{
99 int n;
100 for (n=0; list[n]; n++)
101 if (attr_match(word, list[n]))
102 break;
103 return n;
104}
105
106static enum array_state read_state(int fd)
107{
108 char buf[20];
109 int n = read_attr(buf, 20, fd);
110
111 if (n <= 0)
112 return bad_word;
113 return (enum array_state) match_word(buf, array_states);
114}
115
116static enum sync_action read_action( int fd)
117{
118 char buf[20];
119 int n = read_attr(buf, 20, fd);
120
121 if (n <= 0)
122 return bad_action;
123 return (enum sync_action) match_word(buf, sync_actions);
124}
125
549e9569
NB
126int read_dev_state(int fd)
127{
128 char buf[60];
129 int n = read_attr(buf, 60, fd);
130 char *cp;
131 int rv = 0;
132
133 if (n <= 0)
134 return 0;
135
136 cp = buf;
137 while (cp) {
8d45d196 138 if (attr_match(cp, "faulty"))
549e9569 139 rv |= DS_FAULTY;
8d45d196 140 if (attr_match(cp, "in_sync"))
549e9569 141 rv |= DS_INSYNC;
8d45d196 142 if (attr_match(cp, "write_mostly"))
549e9569 143 rv |= DS_WRITE_MOSTLY;
8d45d196 144 if (attr_match(cp, "spare"))
549e9569 145 rv |= DS_SPARE;
8d45d196
DW
146 if (attr_match(cp, "blocked"))
147 rv |= DS_BLOCKED;
549e9569
NB
148 cp = strchr(cp, ',');
149 if (cp)
150 cp++;
151 }
152 return rv;
153}
154
155
156/* Monitor a set of active md arrays - all of which share the
157 * same metadata - and respond to events that require
158 * metadata update.
159 *
160 * New arrays are detected by another thread which allocates
161 * required memory and attaches the data structure to our list.
162 *
163 * Events:
164 * Array stops.
165 * This is detected by array_state going to 'clear' or 'inactive'.
166 * while we thought it was active.
167 * Response is to mark metadata as clean and 'clear' the array(??)
168 * write-pending
169 * array_state if 'write-pending'
170 * We mark metadata as 'dirty' then set array to 'active'.
171 * active_idle
172 * Either ignore, or mark clean, then mark metadata as clean.
173 *
174 * device fails
175 * detected by rd-N/state reporting "faulty"
8d45d196
DW
176 * mark device as 'failed' in metadata, let the kernel release the
177 * device by writing '-blocked' to rd/state, and finally write 'remove' to
0af73f61
DW
178 * rd/state. Before a disk can be replaced it must be failed and removed
179 * from all container members, this will be preemptive for the other
180 * arrays... safe?
549e9569
NB
181 *
182 * sync completes
183 * sync_action was 'resync' and becomes 'idle' and resync_start becomes
184 * MaxSector
185 * Notify metadata that sync is complete.
186 * "Deal with Degraded"
187 *
188 * recovery completes
189 * sync_action changes from 'recover' to 'idle'
190 * Check each device state and mark metadata if 'faulty' or 'in_sync'.
191 * "Deal with Degraded"
192 *
193 * deal with degraded array
194 * We only do this when first noticing the array is degraded.
195 * This can be when we first see the array, when sync completes or
196 * when recovery completes.
197 *
198 * Check if number of failed devices suggests recovery is needed, and
199 * skip if not.
200 * Ask metadata for a spare device
201 * Add device as not in_sync and give a role
202 * Update metadata.
203 * Start recovery.
204 *
205 * deal with resync
c052ba30
DW
206 * This only happens on finding a new array... mdadm will have set
207 * 'resync_start' to the correct value. If 'resync_start' indicates that an
208 * resync needs to occur set the array to the 'active' state rather than the
209 * initial read-auto state.
549e9569
NB
210 *
211 *
212 *
213 * We wait for a change (poll/select) on array_state, sync_action, and
214 * each rd-X/state file.
215 * When we get any change, we check everything. So read each state file,
216 * then decide what to do.
217 *
218 * The core action is to write new metadata to all devices in the array.
219 * This is done at most once on any wakeup.
220 * After that we might:
221 * - update the array_state
222 * - set the role of some devices.
223 * - request a sync_action
224 *
225 */
226
227static int read_and_act(struct active_array *a)
228{
229 int check_degraded;
2a0bb19e 230 int deactivate = 0;
549e9569
NB
231 struct mdinfo *mdi;
232
233 a->next_state = bad_word;
234 a->next_action = bad_action;
235
236 a->curr_state = read_state(a->info.state_fd);
237 a->curr_action = read_action(a->action_fd);
238 for (mdi = a->info.devs; mdi ; mdi = mdi->next) {
239 mdi->next_state = 0;
8d45d196
DW
240 if (mdi->state_fd > 0)
241 mdi->curr_state = read_dev_state(mdi->state_fd);
549e9569
NB
242 }
243
244 if (a->curr_state <= inactive &&
245 a->prev_state > inactive) {
246 /* array has been stopped */
247 get_sync_pos(a);
248 a->container->ss->mark_clean(a, a->sync_pos);
249 a->next_state = clear;
2a0bb19e 250 deactivate = 1;
549e9569
NB
251 }
252 if (a->curr_state == write_pending) {
4e5528c6 253 a->container->ss->mark_clean(a, 0);
549e9569
NB
254 a->next_state = active;
255 }
256 if (a->curr_state == active_idle) {
257 /* Set array to 'clean' FIRST, then
4e5528c6 258 * a->ss->mark_clean(a, ~0ULL);
549e9569
NB
259 * just ignore for now.
260 */
261 }
262
263 if (a->curr_state == readonly) {
264 /* Well, I'm ready to handle things, so
265 * read-auto is OK. FIXME what if we really want
266 * readonly ???
267 */
c052ba30
DW
268 get_resync_start(a);
269 if (a->resync_start == ~0ULL)
270 a->next_state = read_auto; /* array is clean */
271 else {
4e5528c6 272 a->container->ss->mark_clean(a, 0);
c052ba30
DW
273 a->next_state = active;
274 }
549e9569
NB
275 }
276
277 if (a->curr_action == idle &&
278 a->prev_action == resync) {
4e5528c6
NB
279 /* A resync has finished. The endpoint is recorded in
280 * 'sync_start'. We don't update the metadata
281 * until the array goes inactive or readonly though.
282 * Just check if we need to fiddle spares.
283 */
549e9569
NB
284 check_degraded = 1;
285 }
286
287 if (a->curr_action == idle &&
288 a->prev_action == recover) {
289 for (mdi = a->info.devs ; mdi ; mdi = mdi->next) {
8d45d196
DW
290 a->container->ss->set_disk(a, mdi->disk.raid_disk,
291 mdi->curr_state);
549e9569
NB
292 if (! (mdi->curr_state & DS_INSYNC))
293 check_degraded = 1;
294 }
295 }
296
297
298 for (mdi = a->info.devs ; mdi ; mdi = mdi->next) {
299 if (mdi->curr_state & DS_FAULTY) {
8d45d196
DW
300 a->container->ss->set_disk(a, mdi->disk.raid_disk,
301 mdi->curr_state);
549e9569
NB
302 check_degraded = 1;
303 mdi->next_state = DS_REMOVE;
304 }
305 }
306
307 if (check_degraded) {
308 // FIXME;
309 }
310
311 a->container->ss->sync_metadata(a);
312
313 /* Effect state changes in the array */
314 if (a->next_state != bad_word)
315 write_attr(array_states[a->next_state], a->info.state_fd);
316 if (a->next_action != bad_action)
317 write_attr(sync_actions[a->next_action], a->action_fd);
318 for (mdi = a->info.devs; mdi ; mdi = mdi->next) {
8d45d196
DW
319 if (mdi->next_state == DS_REMOVE && mdi->state_fd > 0) {
320 int remove_err;
321
322 write_attr("-blocked", mdi->state_fd);
323 /* the kernel may not be able to immediately remove the
324 * disk, we can simply wait until the next event to try
325 * again.
326 */
327 remove_err = write_attr("remove", mdi->state_fd);
328 if (!remove_err) {
329 close(mdi->state_fd);
330 mdi->state_fd = -1;
331 }
332 }
549e9569
NB
333 if (mdi->next_state & DS_INSYNC)
334 write_attr("+in_sync", mdi->state_fd);
335 }
336
337 /* move curr_ to prev_ */
338 a->prev_state = a->curr_state;
339
340 a->prev_action = a->curr_action;
341
342 for (mdi = a->info.devs; mdi ; mdi = mdi->next) {
343 mdi->prev_state = mdi->curr_state;
344 mdi->next_state = 0;
345 }
346
2a0bb19e
DW
347 if (deactivate)
348 a->container = NULL;
349
549e9569
NB
350 return 1;
351}
352
0af73f61
DW
353static struct mdinfo *
354find_device(struct active_array *a, int major, int minor)
355{
356 struct mdinfo *mdi;
357
358 for (mdi = a->info.devs ; mdi ; mdi = mdi->next)
359 if (mdi->disk.major == major && mdi->disk.minor == minor)
360 return mdi;
361
362 return NULL;
363}
364
365static void reconcile_failed(struct active_array *aa, struct mdinfo *failed)
366{
367 struct active_array *a;
368 struct mdinfo *victim;
369
370 for (a = aa; a; a = a->next) {
371 if (!a->container)
372 continue;
373 victim = find_device(a, failed->disk.major, failed->disk.minor);
374 if (!victim)
375 continue;
376
377 if (!(victim->curr_state & DS_FAULTY))
378 write_attr("faulty", victim->state_fd);
379 }
380}
381
3e70c845
DW
382static int handle_remove_device(struct md_remove_device_cmd *cmd, struct active_array *aa)
383{
384 struct active_array *a;
385 struct mdinfo *victim;
386 int rv;
387
388 /* scan all arrays for the given device, if ->state_fd is closed (-1)
389 * in all cases then mark the disk as removed in the metadata.
390 * Otherwise reply that it is busy.
391 */
392
393 /* pass1 check that it is not in use anywhere */
394 /* note: we are safe from re-adds as long as the device exists in the
395 * container
396 */
397 for (a = aa; a; a = a->next) {
398 if (!a->container)
399 continue;
400 victim = find_device(a, major(cmd->rdev), minor(cmd->rdev));
401 if (!victim)
402 continue;
403 if (victim->state_fd > 0)
404 return -EBUSY;
405 }
406
407 /* pass2 schedule and process removal per array */
408 for (a = aa; a; a = a->next) {
409 if (!a->container)
410 continue;
411 victim = find_device(a, major(cmd->rdev), minor(cmd->rdev));
412 if (!victim)
413 continue;
414 victim->curr_state |= DS_REMOVE;
415 rv = read_and_act(a);
416 if (rv < 0)
417 return rv;
418 }
419
420 return 0;
421}
422
423static int handle_pipe(struct md_generic_cmd *cmd, struct active_array *aa)
424{
425 switch (cmd->action) {
426 case md_action_ping_monitor:
427 return 0;
428 case md_action_remove_device:
429 return handle_remove_device((void *) cmd, aa);
430 }
431
432 return -1;
433}
434
435static int wait_and_act(struct active_array *aa, int pfd, int monfd, int nowait)
549e9569
NB
436{
437 fd_set rfds;
438 int maxfd = 0;
439 struct active_array *a;
440 int rv;
0af73f61 441 struct mdinfo *mdi;
549e9569
NB
442
443 FD_ZERO(&rfds);
444
445 add_fd(&rfds, &maxfd, pfd);
446 for (a = aa ; a ; a = a->next) {
2a0bb19e
DW
447 /* once an array has been deactivated only the manager
448 * thread can make us care about it again
449 */
450 if (!a->container)
451 continue;
452
549e9569
NB
453 add_fd(&rfds, &maxfd, a->info.state_fd);
454 add_fd(&rfds, &maxfd, a->action_fd);
455 for (mdi = a->info.devs ; mdi ; mdi = mdi->next)
456 add_fd(&rfds, &maxfd, mdi->state_fd);
457 }
458
459 if (!nowait) {
460 rv = select(maxfd+1, &rfds, NULL, NULL, NULL);
461
462 if (rv <= 0)
463 return rv;
464
465 if (FD_ISSET(pfd, &rfds)) {
3e70c845
DW
466 int err = -1;
467
468 if (read(pfd, &err, 1) > 0)
469 err = handle_pipe(active_cmd, aa);
470 write(monfd, &err, 1);
549e9569
NB
471 }
472 }
473
474 for (a = aa; a ; a = a->next) {
2a0bb19e 475 if (a->replaces && !discard_this) {
549e9569
NB
476 struct active_array **ap;
477 for (ap = &a->next; *ap && *ap != a->replaces;
478 ap = & (*ap)->next)
479 ;
480 if (*ap)
481 *ap = (*ap)->next;
482 discard_this = a->replaces;
483 a->replaces = NULL;
484 }
2a0bb19e
DW
485 if (a->container)
486 rv += read_and_act(a);
549e9569 487 }
0af73f61
DW
488
489 /* propagate failures across container members */
490 for (a = aa; a ; a = a->next) {
491 if (!a->container)
492 continue;
493 for (mdi = a->info.devs ; mdi ; mdi = mdi->next)
494 if (mdi->curr_state & DS_FAULTY)
495 reconcile_failed(aa, mdi);
496 }
497
549e9569
NB
498 return rv;
499}
500
501void do_monitor(struct supertype *container)
502{
503 int rv;
504 int first = 1;
505 do {
3e70c845
DW
506 rv = wait_and_act(container->arrays, container->mgr_pipe[0],
507 container->mon_pipe[1], first);
549e9569
NB
508 first = 0;
509 } while (rv >= 0);
510}