]>
git.ipfire.org Git - thirdparty/mdadm.git/blob - monitor.c
2 * mdmon - monitor external metadata arrays
4 * Copyright (C) 2007-2009 Neil Brown <neilb@suse.de>
5 * Copyright (C) 2007-2009 Intel Corporation
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms and conditions of the GNU General Public License,
9 * version 2, as published by the Free Software Foundation.
11 * This program is distributed in the hope it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
16 * You should have received a copy of the GNU General Public License along with
17 * this program; if not, write to the Free Software Foundation, Inc.,
18 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
23 #include <sys/syscall.h>
24 #include <sys/select.h>
27 static char *array_states
[] = {
28 "clear", "inactive", "suspended", "readonly", "read-auto",
29 "clean", "active", "write-pending", "active-idle", NULL
};
30 static char *sync_actions
[] = {
31 "idle", "reshape", "resync", "recover", "check", "repair", NULL
34 static int write_attr(char *attr
, int fd
)
36 return write(fd
, attr
, strlen(attr
));
39 static void add_fd(fd_set
*fds
, int *maxfd
, int fd
)
48 static int read_attr(char *buf
, int len
, int fd
)
57 n
= read(fd
, buf
, len
- 1);
69 static unsigned long long read_resync_start(int fd
)
74 n
= read_attr(buf
, 30, fd
);
77 if (strncmp(buf
, "none", 4) == 0)
80 return strtoull(buf
, NULL
, 10);
83 static unsigned long long read_sync_completed(int fd
)
85 unsigned long long val
;
90 n
= read_attr(buf
, 50, fd
);
95 val
= strtoull(buf
, &ep
, 0);
96 if (ep
== buf
|| (*ep
!= 0 && *ep
!= '\n' && *ep
!= ' '))
101 static enum array_state
read_state(int fd
)
104 int n
= read_attr(buf
, 20, fd
);
108 return (enum array_state
) sysfs_match_word(buf
, array_states
);
111 static enum sync_action
read_action( int fd
)
114 int n
= read_attr(buf
, 20, fd
);
118 return (enum sync_action
) sysfs_match_word(buf
, sync_actions
);
121 int read_dev_state(int fd
)
124 int n
= read_attr(buf
, 60, fd
);
133 if (sysfs_attr_match(cp
, "faulty"))
135 if (sysfs_attr_match(cp
, "in_sync"))
137 if (sysfs_attr_match(cp
, "write_mostly"))
138 rv
|= DS_WRITE_MOSTLY
;
139 if (sysfs_attr_match(cp
, "spare"))
141 if (sysfs_attr_match(cp
, "blocked"))
143 cp
= strchr(cp
, ',');
150 static void signal_manager(void)
152 /* tgkill(getpid(), mon_tid, SIGUSR1); */
154 syscall(SYS_tgkill
, pid
, mgr_tid
, SIGUSR1
);
157 /* Monitor a set of active md arrays - all of which share the
158 * same metadata - and respond to events that require
161 * New arrays are detected by another thread which allocates
162 * required memory and attaches the data structure to our list.
166 * This is detected by array_state going to 'clear' or 'inactive'.
167 * while we thought it was active.
168 * Response is to mark metadata as clean and 'clear' the array(??)
170 * array_state if 'write-pending'
171 * We mark metadata as 'dirty' then set array to 'active'.
173 * Either ignore, or mark clean, then mark metadata as clean.
176 * detected by rd-N/state reporting "faulty"
177 * mark device as 'failed' in metadata, let the kernel release the
178 * device by writing '-blocked' to rd/state, and finally write 'remove' to
179 * rd/state. Before a disk can be replaced it must be failed and removed
180 * from all container members, this will be preemptive for the other
184 * sync_action was 'resync' and becomes 'idle' and resync_start becomes
186 * Notify metadata that sync is complete.
189 * sync_action changes from 'recover' to 'idle'
190 * Check each device state and mark metadata if 'faulty' or 'in_sync'.
193 * This only happens on finding a new array... mdadm will have set
194 * 'resync_start' to the correct value. If 'resync_start' indicates that an
195 * resync needs to occur set the array to the 'active' state rather than the
196 * initial read-auto state.
200 * We wait for a change (poll/select) on array_state, sync_action, and
201 * each rd-X/state file.
202 * When we get any change, we check everything. So read each state file,
203 * then decide what to do.
205 * The core action is to write new metadata to all devices in the array.
206 * This is done at most once on any wakeup.
207 * After that we might:
208 * - update the array_state
209 * - set the role of some devices.
210 * - request a sync_action
214 #define ARRAY_DIRTY 1
216 static int read_and_act(struct active_array
*a
)
218 unsigned long long sync_completed
;
219 int check_degraded
= 0;
220 int check_reshape
= 0;
226 a
->next_state
= bad_word
;
227 a
->next_action
= bad_action
;
229 a
->curr_state
= read_state(a
->info
.state_fd
);
230 a
->curr_action
= read_action(a
->action_fd
);
231 a
->info
.resync_start
= read_resync_start(a
->resync_start_fd
);
232 sync_completed
= read_sync_completed(a
->sync_completed_fd
);
233 for (mdi
= a
->info
.devs
; mdi
; mdi
= mdi
->next
) {
236 if (mdi
->state_fd
>= 0) {
237 mdi
->recovery_start
= read_resync_start(mdi
->recovery_fd
);
238 mdi
->curr_state
= read_dev_state(mdi
->state_fd
);
242 if (a
->curr_state
> inactive
&&
243 a
->prev_state
== inactive
) {
244 /* array has been started
245 * possible that container operation has to be completed
247 a
->container
->ss
->set_array_state(a
, 0);
249 if (a
->curr_state
<= inactive
&&
250 a
->prev_state
> inactive
) {
251 /* array has been stopped */
252 a
->container
->ss
->set_array_state(a
, 1);
253 a
->next_state
= clear
;
256 if (a
->curr_state
== write_pending
) {
257 a
->container
->ss
->set_array_state(a
, 0);
258 a
->next_state
= active
;
261 if (a
->curr_state
== active_idle
) {
262 /* Set array to 'clean' FIRST, then mark clean
265 a
->next_state
= clean
;
268 if (a
->curr_state
== clean
) {
269 a
->container
->ss
->set_array_state(a
, 1);
271 if (a
->curr_state
== active
||
272 a
->curr_state
== suspended
||
273 a
->curr_state
== bad_word
)
275 if (a
->curr_state
== readonly
) {
276 /* Well, I'm ready to handle things. If readonly
277 * wasn't requested, transition to read-auto.
280 read_attr(buf
, sizeof(buf
), a
->metadata_fd
);
281 if (strncmp(buf
, "external:-", 10) == 0) {
282 /* explicit request for readonly array. Leave it alone */
285 if (a
->container
->ss
->set_array_state(a
, 2))
286 a
->next_state
= read_auto
; /* array is clean */
288 a
->next_state
= active
; /* Now active for recovery etc */
295 a
->curr_action
== idle
&&
296 a
->prev_action
== resync
) {
297 /* A resync has finished. The endpoint is recorded in
298 * 'sync_start'. We don't update the metadata
299 * until the array goes inactive or readonly though.
300 * Just check if we need to fiddle spares.
302 a
->container
->ss
->set_array_state(a
, a
->curr_state
<= clean
);
307 a
->curr_action
== idle
&&
308 a
->prev_action
== recover
) {
309 /* A recovery has finished. Some disks may be in sync now,
310 * and the array may no longer be degraded
312 for (mdi
= a
->info
.devs
; mdi
; mdi
= mdi
->next
) {
313 a
->container
->ss
->set_disk(a
, mdi
->disk
.raid_disk
,
315 if (! (mdi
->curr_state
& DS_INSYNC
))
319 if (count
!= a
->info
.array
.raid_disks
)
324 a
->curr_action
== reshape
&&
325 a
->prev_action
!= reshape
)
326 /* reshape was requested by mdadm. Need to see if
327 * new devices have been added. Manager does that
328 * when it sees check_reshape
332 /* Check for failures and if found:
333 * 1/ Record the failure in the metadata and unblock the device.
334 * FIXME update the kernel to stop notifying on failed drives when
335 * the array is readonly and we have cleared 'blocked'
336 * 2/ Try to remove the device if the array is writable, or can be
339 for (mdi
= a
->info
.devs
; mdi
; mdi
= mdi
->next
) {
340 if (mdi
->curr_state
& DS_FAULTY
) {
341 a
->container
->ss
->set_disk(a
, mdi
->disk
.raid_disk
,
344 if (mdi
->curr_state
& DS_BLOCKED
)
345 mdi
->next_state
|= DS_UNBLOCK
;
346 if (a
->curr_state
== read_auto
) {
347 a
->container
->ss
->set_array_state(a
, 0);
348 a
->next_state
= active
;
350 if (a
->curr_state
> readonly
)
351 mdi
->next_state
|= DS_REMOVE
;
355 /* Check for recovery checkpoint notifications. We need to be a
356 * minimum distance away from the last checkpoint to prevent
357 * over checkpointing. Note reshape checkpointing is handled
358 * in the second branch.
360 if (sync_completed
> a
->last_checkpoint
&&
361 sync_completed
- a
->last_checkpoint
> a
->info
.component_size
>> 4 &&
362 a
->curr_action
> reshape
) {
363 /* A (non-reshape) sync_action has reached a checkpoint.
364 * Record the updated position in the metadata
366 a
->last_checkpoint
= sync_completed
;
367 a
->container
->ss
->set_array_state(a
, a
->curr_state
<= clean
);
368 } else if ((a
->curr_action
== idle
&& a
->prev_action
== reshape
) ||
369 (a
->curr_action
== reshape
370 && sync_completed
> a
->last_checkpoint
) ) {
371 /* Reshape has progressed or completed so we need to
372 * update the array state - and possibly the array size
374 if (sync_completed
!= 0)
375 a
->last_checkpoint
= sync_completed
;
376 /* We might need to update last_checkpoint depending on
377 * the reason that reshape finished.
378 * if array reshape is really finished:
379 * set check point to the end, this allows
380 * set_array_state() to finalize reshape in metadata
381 * if reshape if broken: do not set checkpoint to the end
382 * this allows for reshape restart from checkpoint
384 if ((a
->curr_action
!= reshape
) &&
385 (a
->prev_action
== reshape
)) {
387 if ((sysfs_get_str(&a
->info
, NULL
,
390 sizeof(buf
)) >= 0) &&
391 strncmp(buf
, "none", 4) == 0)
392 a
->last_checkpoint
= a
->info
.component_size
;
394 a
->container
->ss
->set_array_state(a
, a
->curr_state
<= clean
);
395 a
->last_checkpoint
= sync_completed
;
398 if (sync_completed
> a
->last_checkpoint
)
399 a
->last_checkpoint
= sync_completed
;
401 a
->container
->ss
->sync_metadata(a
->container
);
402 dprintf("%s(%d): state:%s action:%s next(", __func__
, a
->info
.container_member
,
403 array_states
[a
->curr_state
], sync_actions
[a
->curr_action
]);
405 /* Effect state changes in the array */
406 if (a
->next_state
!= bad_word
) {
407 dprintf(" state:%s", array_states
[a
->next_state
]);
408 write_attr(array_states
[a
->next_state
], a
->info
.state_fd
);
410 if (a
->next_action
!= bad_action
) {
411 write_attr(sync_actions
[a
->next_action
], a
->action_fd
);
412 dprintf(" action:%s", sync_actions
[a
->next_action
]);
414 for (mdi
= a
->info
.devs
; mdi
; mdi
= mdi
->next
) {
415 if (mdi
->next_state
& DS_UNBLOCK
) {
416 dprintf(" %d:-blocked", mdi
->disk
.raid_disk
);
417 write_attr("-blocked", mdi
->state_fd
);
420 if ((mdi
->next_state
& DS_REMOVE
) && mdi
->state_fd
>= 0) {
423 /* The kernel may not be able to immediately remove the
424 * disk. In that case we wait a little while and
427 remove_result
= write_attr("remove", mdi
->state_fd
);
428 if (remove_result
> 0) {
429 dprintf(" %d:removed", mdi
->disk
.raid_disk
);
430 close(mdi
->state_fd
);
431 close(mdi
->recovery_fd
);
436 if (mdi
->next_state
& DS_INSYNC
) {
437 write_attr("+in_sync", mdi
->state_fd
);
438 dprintf(" %d:+in_sync", mdi
->disk
.raid_disk
);
443 /* move curr_ to prev_ */
444 a
->prev_state
= a
->curr_state
;
446 a
->prev_action
= a
->curr_action
;
448 for (mdi
= a
->info
.devs
; mdi
; mdi
= mdi
->next
) {
449 mdi
->prev_state
= mdi
->curr_state
;
453 if (check_degraded
|| check_reshape
) {
454 /* manager will do the actual check */
456 a
->check_degraded
= 1;
458 a
->check_reshape
= 1;
468 static struct mdinfo
*
469 find_device(struct active_array
*a
, int major
, int minor
)
473 for (mdi
= a
->info
.devs
; mdi
; mdi
= mdi
->next
)
474 if (mdi
->disk
.major
== major
&& mdi
->disk
.minor
== minor
)
480 static void reconcile_failed(struct active_array
*aa
, struct mdinfo
*failed
)
482 struct active_array
*a
;
483 struct mdinfo
*victim
;
485 for (a
= aa
; a
; a
= a
->next
) {
486 if (!a
->container
|| a
->to_remove
)
488 victim
= find_device(a
, failed
->disk
.major
, failed
->disk
.minor
);
492 if (!(victim
->curr_state
& DS_FAULTY
))
493 write_attr("faulty", victim
->state_fd
);
498 static void dprint_wake_reasons(fd_set
*fds
)
506 fprintf(stderr
, "monitor: wake ( ");
507 for (i
= 0; i
< FD_SETSIZE
; i
++) {
508 if (FD_ISSET(i
, fds
)) {
509 sprintf(proc_path
, "/proc/%d/fd/%d",
512 rv
= readlink(proc_path
, link
, sizeof(link
) - 1);
514 fprintf(stderr
, "%d:unknown ", i
);
518 basename
= strrchr(link
, '/');
519 fprintf(stderr
, "%d:%s ",
520 i
, basename
? ++basename
: link
);
523 fprintf(stderr
, ")\n");
527 int monitor_loop_cnt
;
529 static int wait_and_act(struct supertype
*container
, int nowait
)
533 struct active_array
**aap
= &container
->arrays
;
534 struct active_array
*a
, **ap
;
537 static unsigned int dirty_arrays
= ~0; /* start at some non-zero value */
541 for (ap
= aap
; *ap
;) {
543 /* once an array has been deactivated we want to
544 * ask the manager to discard it.
546 if (!a
->container
|| a
->to_remove
) {
558 add_fd(&rfds
, &maxfd
, a
->info
.state_fd
);
559 add_fd(&rfds
, &maxfd
, a
->action_fd
);
560 add_fd(&rfds
, &maxfd
, a
->sync_completed_fd
);
561 for (mdi
= a
->info
.devs
; mdi
; mdi
= mdi
->next
)
562 add_fd(&rfds
, &maxfd
, mdi
->state_fd
);
567 if (manager_ready
&& (*aap
== NULL
|| (sigterm
&& !dirty_arrays
))) {
568 /* No interesting arrays, or we have been told to
569 * terminate and everything is clean. Lets see about
570 * exiting. Note that blocking at this point is not a
571 * problem as there are no active arrays, there is
572 * nothing that we need to be ready to do.
576 fd
= open_dev_excl(container
->devnm
);
578 fd
= open_dev_flags(container
->devnm
, O_RDONLY
|O_EXCL
);
579 if (fd
>= 0 || errno
!= EBUSY
) {
580 /* OK, we are safe to leave */
581 if (sigterm
&& !dirty_arrays
)
582 dprintf("caught sigterm, all clean... exiting\n");
584 dprintf("no arrays to monitor... exiting\n");
586 /* On SIGTERM, someone (the take-over mdmon) will
589 remove_pidfile(container
->devnm
);
602 if (*aap
== NULL
|| container
->retry_soon
) {
603 /* just waiting to get O_EXCL access */
605 ts
.tv_nsec
= 20000000ULL;
607 sigprocmask(SIG_UNBLOCK
, NULL
, &set
);
608 sigdelset(&set
, SIGUSR1
);
609 monitor_loop_cnt
|= 1;
610 rv
= pselect(maxfd
+1, NULL
, NULL
, &rfds
, &ts
, &set
);
611 monitor_loop_cnt
+= 1;
612 if (rv
== -1 && errno
== EINTR
)
615 dprint_wake_reasons(&rfds
);
617 container
->retry_soon
= 0;
621 struct metadata_update
*this;
623 for (this = update_queue
; this ; this = this->next
)
624 container
->ss
->process_update(container
, this);
626 update_queue_handled
= update_queue
;
629 container
->ss
->sync_metadata(container
);
634 for (a
= *aap
; a
; a
= a
->next
) {
636 if (a
->replaces
&& !discard_this
) {
637 struct active_array
**ap
;
638 for (ap
= &a
->next
; *ap
&& *ap
!= a
->replaces
;
643 discard_this
= a
->replaces
;
645 /* FIXME check if device->state_fd need to be cleared?*/
648 if (a
->container
&& !a
->to_remove
) {
649 int ret
= read_and_act(a
);
651 dirty_arrays
+= !!(ret
& ARRAY_DIRTY
);
652 /* when terminating stop manipulating the array after it
653 * is clean, but make sure read_and_act() is given a
654 * chance to handle 'active_idle'
656 if (sigterm
&& !(ret
& ARRAY_DIRTY
))
657 a
->container
= NULL
; /* stop touching this array */
658 if (ret
& ARRAY_BUSY
)
659 container
->retry_soon
= 1;
663 /* propagate failures across container members */
664 for (a
= *aap
; a
; a
= a
->next
) {
665 if (!a
->container
|| a
->to_remove
)
667 for (mdi
= a
->info
.devs
; mdi
; mdi
= mdi
->next
)
668 if (mdi
->curr_state
& DS_FAULTY
)
669 reconcile_failed(*aap
, mdi
);
675 void do_monitor(struct supertype
*container
)
680 rv
= wait_and_act(container
, first
);