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Remove mon_pipe for communicating from monitor to manager
[thirdparty/mdadm.git] / managemon.c
CommitLineData
549e9569
NB
1
2/*
3 * The management thread for monitoring active md arrays.
4 * This thread does things which might block such as memory
5 * allocation.
6 * In particular:
7 *
8 * - Find out about new arrays in this container.
9 * Allocate the data structures and open the files.
10 *
11 * For this we watch /proc/mdstat and find new arrays with
12 * metadata type that confirms sharing. e.g. "md4"
13 * When we find a new array we slip it into the list of
14 * arrays and signal 'monitor' by writing to a pipe.
15 *
16 * - Respond to reshape requests by allocating new data structures
17 * and opening new files.
18 *
19 * These come as a change to raid_disks. We allocate a new
20 * version of the data structures and slip it into the list.
21 * 'monitor' will notice and release the old version.
22 * Changes to level, chunksize, layout.. do not need re-allocation.
23 * Reductions in raid_disks don't really either, but we handle
24 * them the same way for consistency.
25 *
26 * - When a device is added to the container, we add it to the metadata
27 * as a spare.
28 *
6c3fb95c
NB
29 * - Deal with degraded array
30 * We only do this when first noticing the array is degraded.
31 * This can be when we first see the array, when sync completes or
32 * when recovery completes.
33 *
34 * Check if number of failed devices suggests recovery is needed, and
35 * skip if not.
36 * Ask metadata to allocate a spare device
37 * Add device as not in_sync and give a role
38 * Update metadata.
39 * Open sysfs files and pass to monitor.
40 * Make sure that monitor Starts recovery....
549e9569
NB
41 *
42 * - Pass on metadata updates from external programs such as
43 * mdadm creating a new array.
44 *
45 * This is most-messy.
46 * It might involve adding a new array or changing the status of
47 * a spare, or any reconfig that the kernel doesn't get involved in.
48 *
49 * The required updates are received via a named pipe. There will
50 * be one named pipe for each container. Each message contains a
51 * sync marker: 0x5a5aa5a5, A byte count, and the message. This is
52 * passed to the metadata handler which will interpret and process it.
53 * For 'DDF' messages are internal data blocks with the leading
54 * 'magic number' signifying what sort of data it is.
55 *
56 */
57
58/*
59 * We select on /proc/mdstat and the named pipe.
60 * We create new arrays or updated version of arrays and slip
61 * them into the head of the list, then signal 'monitor' via a pipe write.
62 * 'monitor' will notice and place the old array on a return list.
63 * Metadata updates are placed on a queue just like they arrive
64 * from the named pipe.
65 *
66 * When new arrays are found based on correct metadata string, we
67 * need to identify them with an entry in the metadata. Maybe we require
68 * the metadata to be mdX/NN when NN is the index into an appropriate table.
69 *
70 */
71
72/*
73 * List of tasks:
74 * - Watch for spares to be added to the container, and write updated
75 * metadata to them.
76 * - Watch for new arrays using this container, confirm they match metadata
77 * and if so, start monitoring them
78 * - Watch for spares being added to monitored arrays. This shouldn't
79 * happen, as we should do all the adding. Just remove them.
80 * - Watch for change in raid-disks, chunk-size, etc. Update metadata and
81 * start a reshape.
82 */
83#ifndef _GNU_SOURCE
84#define _GNU_SOURCE
85#endif
86#include "mdadm.h"
87#include "mdmon.h"
88#include <sys/socket.h>
1ed3f387 89#include <signal.h>
549e9569 90
2a0bb19e
DW
91static void close_aa(struct active_array *aa)
92{
93 struct mdinfo *d;
94
95 for (d = aa->info.devs; d; d = d->next)
96 close(d->state_fd);
97
98 close(aa->action_fd);
99 close(aa->info.state_fd);
100 close(aa->resync_start_fd);
2a0bb19e
DW
101}
102
549e9569
NB
103static void free_aa(struct active_array *aa)
104{
2a0bb19e
DW
105 /* Note that this doesn't close fds if they are being used
106 * by a clone. ->container will be set for a clone
549e9569 107 */
4e6e574a 108 dprintf("%s: devnum: %d\n", __func__, aa->devnum);
2a0bb19e
DW
109 if (!aa->container)
110 close_aa(aa);
549e9569
NB
111 while (aa->info.devs) {
112 struct mdinfo *d = aa->info.devs;
113 aa->info.devs = d->next;
114 free(d);
115 }
116 free(aa);
117}
118
6c3fb95c
NB
119static struct active_array *duplicate_aa(struct active_array *aa)
120{
121 struct active_array *newa = malloc(sizeof(*newa));
122 struct mdinfo **dp1, **dp2;
123
124 *newa = *aa;
125 newa->next = NULL;
126 newa->replaces = NULL;
127 newa->info.next = NULL;
128
129 dp2 = &newa->info.devs;
130
131 for (dp1 = &aa->info.devs; *dp1; dp1 = &(*dp1)->next) {
132 struct mdinfo *d;
133 if ((*dp1)->state_fd < 0)
134 continue;
135
136 d = malloc(sizeof(*d));
137 *d = **dp1;
138 *dp2 = d;
139 dp2 = & d->next;
140 }
7e1432fb 141 *dp2 = NULL;
6c3fb95c
NB
142
143 return newa;
144}
145
2a0bb19e
DW
146static void write_wakeup(struct supertype *c)
147{
3e70c845
DW
148 static struct md_generic_cmd cmd = { .action = md_action_ping_monitor };
149 int err;
150
151 active_cmd = &cmd;
152
153 /* send the monitor thread a pointer to the ping action */
154 write(c->mgr_pipe[1], &err, 1);
2a0bb19e
DW
155}
156
1ed3f387
NB
157static void remove_old(void)
158{
159 if (discard_this) {
160 discard_this->next = NULL;
161 free_aa(discard_this);
162 if (pending_discard == discard_this)
163 pending_discard = NULL;
164 discard_this = NULL;
165 }
166}
167
549e9569
NB
168static void replace_array(struct supertype *container,
169 struct active_array *old,
170 struct active_array *new)
171{
172 /* To replace an array, we add it to the top of the list
173 * marked with ->replaces to point to the original.
174 * 'monitor' will take the original out of the list
175 * and put it on 'discard_this'. We take it from there
176 * and discard it.
177 */
1ed3f387 178 remove_old();
549e9569 179 while (pending_discard) {
1ed3f387 180 write_wakeup(container);
549e9569
NB
181 while (discard_this == NULL)
182 sleep(1);
1ed3f387 183 remove_old();
549e9569
NB
184 }
185 pending_discard = old;
186 new->replaces = old;
187 new->next = container->arrays;
188 container->arrays = new;
2a0bb19e 189 write_wakeup(container);
549e9569
NB
190}
191
2e735d19
NB
192struct metadata_update *update_queue = NULL;
193struct metadata_update *update_queue_handled = NULL;
194struct metadata_update *update_queue_pending = NULL;
195
196void check_update_queue(struct supertype *container)
197{
198 while (update_queue_handled) {
199 struct metadata_update *this = update_queue_handled;
200 update_queue_handled = this->next;
904c1ef7
NB
201 free(this->buf);
202 if (this->space)
203 free(this->space);
2e735d19
NB
204 free(this);
205 }
206 if (update_queue == NULL &&
207 update_queue_pending) {
208 update_queue = update_queue_pending;
209 update_queue_pending = NULL;
210 write_wakeup(container);
211 }
212}
213
6c3fb95c 214static void queue_metadata_update(struct metadata_update *mu)
2e735d19
NB
215{
216 struct metadata_update **qp;
217
218 qp = &update_queue_pending;
219 while (*qp)
220 qp = & ((*qp)->next);
221 *qp = mu;
222}
223
224void wait_update_handled(void)
225{
226 /* Wait for any pending update to be handled by monitor.
227 * i.e. wait until update_queue is NULL
228 */
229 while (update_queue)
230 usleep(100 * 1000);
231}
232
549e9569
NB
233static void manage_container(struct mdstat_ent *mdstat,
234 struct supertype *container)
235{
236 /* The only thing of interest here is if a new device
237 * has been added to the container. We add it to the
238 * array ignoring any metadata on it.
239 * FIXME should we look for compatible metadata and take hints
240 * about spare assignment.... probably not.
549e9569
NB
241 */
242 if (mdstat->devcnt != container->devcnt) {
243 /* read /sys/block/NAME/md/dev-??/block/dev to find out
244 * what is there, and compare with container->info.devs
245 * To see what is removed and what is added.
246 * These need to be remove from, or added to, the array
247 */
248 // FIXME
249 container->devcnt = mdstat->devcnt;
250 }
251}
252
253static void manage_member(struct mdstat_ent *mdstat,
254 struct active_array *a)
255{
256 /* Compare mdstat info with known state of member array.
257 * We do not need to look for device state changes here, that
258 * is dealt with by the monitor.
259 *
260 * We just look for changes which suggest that a reshape is
261 * being requested.
262 * Unfortunately decreases in raid_disks don't show up in
263 * mdstat until the reshape completes FIXME.
6c3fb95c
NB
264 *
265 * Actually, we also want to handle degraded arrays here by
266 * trying to find and assign a spare.
267 * We do that whenever the monitor tells us too.
549e9569
NB
268 */
269 // FIXME
270 a->info.array.raid_disks = mdstat->raid_disks;
271 a->info.array.chunk_size = mdstat->chunk_size;
272 // MORE
273
6c3fb95c
NB
274 if (a->check_degraded) {
275 struct metadata_update *updates = NULL;
276 struct mdinfo *newdev;
277 struct active_array *newa;
278 wait_update_handled();
279 a->check_degraded = 0;
280
281 /* The array may not be degraded, this is just a good time
282 * to check.
283 */
284 newdev = a->container->ss->activate_spare(a, &updates);
285 if (newdev) {
286 struct mdinfo *d;
287 /* Cool, we can add a device or several. */
288 newa = duplicate_aa(a);
289 /* suspend recovery - maybe not needed */
290
291 /* Add device to array and set offset/size/slot.
292 * and open files for each newdev */
293 for (d = newdev; d ; d = d->next) {
294 struct mdinfo *newd;
295 if (sysfs_add_disk(&newa->info, d))
296 continue;
297 newd = newa->info.devs;
298 newd->state_fd = sysfs_open(a->devnum,
299 newd->sys_name,
300 "state");
301 newd->prev_state
302 = read_dev_state(newd->state_fd);
303 newd->curr_state = newd->prev_state;
304 }
305 queue_metadata_update(updates);
306 replace_array(a->container, a, newa);
307 sysfs_set_str(&a->info, NULL, "sync_action", "repair");
308 }
309 }
549e9569
NB
310}
311
549e9569 312static void manage_new(struct mdstat_ent *mdstat,
2a0bb19e
DW
313 struct supertype *container,
314 struct active_array *victim)
549e9569
NB
315{
316 /* A new array has appeared in this container.
317 * Hopefully it is already recorded in the metadata.
318 * Check, then create the new array to report it to
319 * the monitor.
320 */
321
322 struct active_array *new;
323 struct mdinfo *mdi, *di;
cba0191b 324 char *inst;
549e9569
NB
325 int i;
326
327 new = malloc(sizeof(*new));
328
d52690ac
NB
329 memset(new, 0, sizeof(*new));
330
549e9569 331 new->devnum = mdstat->devnum;
7e1432fb 332 strcpy(new->info.sys_name, devnum2devname(new->devnum));
549e9569
NB
333
334 new->prev_state = new->curr_state = new->next_state = inactive;
335 new->prev_action= new->curr_action= new->next_action= idle;
336
337 new->container = container;
338
cba0191b 339 inst = &mdstat->metadata_version[10+strlen(container->devname)+1];
549e9569
NB
340
341 mdi = sysfs_read(-1, new->devnum,
342 GET_LEVEL|GET_CHUNK|GET_DISKS|
343 GET_DEVS|GET_OFFSET|GET_SIZE|GET_STATE);
344 if (!mdi) {
345 /* Eeek. Cannot monitor this array.
346 * Mark it to be ignored by setting container to NULL
347 */
348 new->container = NULL;
2a0bb19e 349 replace_array(container, victim, new);
549e9569
NB
350 return;
351 }
352
353 new->info.array = mdi->array;
354
355 for (i = 0; i < new->info.array.raid_disks; i++) {
356 struct mdinfo *newd = malloc(sizeof(*newd));
357
358 for (di = mdi->devs; di; di = di->next)
359 if (i == di->disk.raid_disk)
360 break;
361
362 if (di) {
363 memcpy(newd, di, sizeof(*newd));
364
549e9569
NB
365 newd->state_fd = sysfs_open(new->devnum,
366 newd->sys_name,
367 "state");
368
369 newd->prev_state = read_dev_state(newd->state_fd);
6c3fb95c 370 newd->curr_state = newd->prev_state;
549e9569
NB
371 } else {
372 newd->state_fd = -1;
7e1432fb
NB
373 newd->disk.raid_disk = i;
374 newd->prev_state = DS_REMOVE;
375 newd->curr_state = DS_REMOVE;
549e9569 376 }
7e1432fb 377 sprintf(newd->sys_name, "rd%d", i);
549e9569
NB
378 newd->next = new->info.devs;
379 new->info.devs = newd;
380 }
381 new->action_fd = sysfs_open(new->devnum, NULL, "sync_action");
382 new->info.state_fd = sysfs_open(new->devnum, NULL, "array_state");
c052ba30 383 new->resync_start_fd = sysfs_open(new->devnum, NULL, "resync_start");
77402e51 384 new->resync_start = 0;
4e6e574a
DW
385 dprintf("%s: inst: %d action: %d state: %d\n", __func__, atoi(inst),
386 new->action_fd, new->info.state_fd);
549e9569 387
4fa5aef9 388 sysfs_free(mdi);
549e9569
NB
389 // finds and compares.
390 if (container->ss->open_new(container, new, inst) < 0) {
391 // FIXME close all those files
392 new->container = NULL;
2a0bb19e 393 replace_array(container, victim, new);
549e9569
NB
394 return;
395 }
2a0bb19e 396 replace_array(container, victim, new);
549e9569
NB
397 return;
398}
399
5d19760d 400void manage(struct mdstat_ent *mdstat, struct supertype *container)
549e9569
NB
401{
402 /* We have just read mdstat and need to compare it with
403 * the known active arrays.
404 * Arrays with the wrong metadata are ignored.
405 */
406
407 for ( ; mdstat ; mdstat = mdstat->next) {
408 struct active_array *a;
409 if (mdstat->devnum == container->devnum) {
410 manage_container(mdstat, container);
411 continue;
412 }
413 if (mdstat->metadata_version == NULL ||
414 strncmp(mdstat->metadata_version, "external:/", 10) != 0 ||
415 strncmp(mdstat->metadata_version+10, container->devname,
416 strlen(container->devname)) != 0 ||
417 mdstat->metadata_version[10+strlen(container->devname)]
418 != '/')
419 /* Not for this array */
420 continue;
421 /* Looks like a member of this container */
5d19760d 422 for (a = container->arrays; a; a = a->next) {
549e9569
NB
423 if (mdstat->devnum == a->devnum) {
424 if (a->container)
425 manage_member(mdstat, a);
426 break;
427 }
428 }
2a0bb19e
DW
429 if (a == NULL || !a->container)
430 manage_new(mdstat, container, a);
549e9569
NB
431 }
432}
433
3e70c845
DW
434static int handle_message(struct supertype *container, struct md_message *msg)
435{
3e70c845
DW
436 struct md_generic_cmd *cmd = msg->buf;
437
438 if (!cmd)
439 return 0;
440
441 switch (cmd->action) {
3e70c845
DW
442
443 default:
444 return -1;
445 }
446}
447
448void read_sock(struct supertype *container)
549e9569
NB
449{
450 int fd;
b109d928
DW
451 struct md_message msg;
452 int terminate = 0;
453 long fl;
454 int tmo = 3; /* 3 second timeout before hanging up the socket */
549e9569 455
3e70c845 456 fd = accept(container->sock, NULL, NULL);
549e9569
NB
457 if (fd < 0)
458 return;
b109d928
DW
459
460 fl = fcntl(fd, F_GETFL, 0);
461 fl |= O_NONBLOCK;
462 fcntl(fd, F_SETFL, fl);
463
464 do {
3e70c845
DW
465 int err;
466
b109d928
DW
467 msg.buf = NULL;
468
469 /* read and validate the message */
470 if (receive_message(fd, &msg, tmo) == 0) {
3e70c845
DW
471 err = handle_message(container, &msg);
472 if (!err)
473 ack(fd, msg.seq, tmo);
474 else
475 nack(fd, err, tmo);
b109d928
DW
476 } else {
477 terminate = 1;
478 nack(fd, -1, tmo);
479 }
480
481 if (msg.buf)
482 free(msg.buf);
483 } while (!terminate);
484
549e9569
NB
485 close(fd);
486}
1ed3f387
NB
487
488static int woke = 0;
489void wake_me(int sig)
490{
491 woke = 1;
492}
493
e0d6609f
NB
494int exit_now = 0;
495int manager_ready = 0;
549e9569
NB
496void do_manager(struct supertype *container)
497{
498 struct mdstat_ent *mdstat;
1ed3f387
NB
499 sigset_t block, orig;
500
501 sigemptyset(&block);
502 sigaddset(&block, SIGUSR1);
503
504 signal(SIGUSR1, wake_me);
549e9569
NB
505
506 do {
1ed3f387
NB
507 woke = 0;
508
e0d6609f
NB
509 if (exit_now)
510 exit(0);
511
549e9569
NB
512 mdstat = mdstat_read(1, 0);
513
5d19760d 514 manage(mdstat, container);
549e9569 515
3e70c845 516 read_sock(container);
549e9569 517
4fa5aef9
DW
518 free_mdstat(mdstat);
519
1ed3f387
NB
520 remove_old();
521
2e735d19
NB
522 check_update_queue(container);
523
e0d6609f 524 manager_ready = 1;
1ed3f387
NB
525 sigprocmask(SIG_SETMASK, &block, &orig);
526 if (woke == 0)
527 mdstat_wait_fd(container->sock, &orig);
528 sigprocmask(SIG_SETMASK, &orig, NULL);
549e9569
NB
529 } while(1);
530}