]>
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
)
44 if (fstat(fd
, &st
) == -1) {
45 dprintf("Invalid fd %d\n", fd
);
48 if (st
.st_nlink
== 0) {
49 dprintf("fd %d was deleted\n", fd
);
57 static int read_attr(char *buf
, int len
, int fd
)
66 n
= read(fd
, buf
, len
- 1);
78 static void read_resync_start(int fd
, unsigned long long *v
)
83 n
= read_attr(buf
, 30, fd
);
85 dprintf("Failed to read resync_start (%d)\n", fd
);
88 if (strncmp(buf
, "none", 4) == 0)
91 *v
= strtoull(buf
, NULL
, 10);
94 static unsigned long long read_sync_completed(int fd
)
96 unsigned long long val
;
101 n
= read_attr(buf
, 50, fd
);
106 val
= strtoull(buf
, &ep
, 0);
107 if (ep
== buf
|| (*ep
!= 0 && *ep
!= '\n' && *ep
!= ' '))
112 static enum array_state
read_state(int fd
)
115 int n
= read_attr(buf
, 20, fd
);
119 return (enum array_state
) sysfs_match_word(buf
, array_states
);
122 static enum sync_action
read_action( int fd
)
125 int n
= read_attr(buf
, 20, fd
);
129 return (enum sync_action
) sysfs_match_word(buf
, sync_actions
);
132 int read_dev_state(int fd
)
135 int n
= read_attr(buf
, sizeof(buf
), fd
);
144 if (sysfs_attr_match(cp
, "faulty"))
146 if (sysfs_attr_match(cp
, "in_sync"))
148 if (sysfs_attr_match(cp
, "write_mostly"))
149 rv
|= DS_WRITE_MOSTLY
;
150 if (sysfs_attr_match(cp
, "spare"))
152 if (sysfs_attr_match(cp
, "blocked"))
154 cp
= strchr(cp
, ',');
161 static void signal_manager(void)
163 /* tgkill(getpid(), mon_tid, SIGUSR1); */
165 syscall(SYS_tgkill
, pid
, mgr_tid
, SIGUSR1
);
168 /* Monitor a set of active md arrays - all of which share the
169 * same metadata - and respond to events that require
172 * New arrays are detected by another thread which allocates
173 * required memory and attaches the data structure to our list.
177 * This is detected by array_state going to 'clear' or 'inactive'.
178 * while we thought it was active.
179 * Response is to mark metadata as clean and 'clear' the array(??)
181 * array_state if 'write-pending'
182 * We mark metadata as 'dirty' then set array to 'active'.
184 * Either ignore, or mark clean, then mark metadata as clean.
187 * detected by rd-N/state reporting "faulty"
188 * mark device as 'failed' in metadata, let the kernel release the
189 * device by writing '-blocked' to rd/state, and finally write 'remove' to
190 * rd/state. Before a disk can be replaced it must be failed and removed
191 * from all container members, this will be preemptive for the other
195 * sync_action was 'resync' and becomes 'idle' and resync_start becomes
197 * Notify metadata that sync is complete.
200 * sync_action changes from 'recover' to 'idle'
201 * Check each device state and mark metadata if 'faulty' or 'in_sync'.
204 * This only happens on finding a new array... mdadm will have set
205 * 'resync_start' to the correct value. If 'resync_start' indicates that an
206 * resync needs to occur set the array to the 'active' state rather than the
207 * initial read-auto state.
211 * We wait for a change (poll/select) on array_state, sync_action, and
212 * each rd-X/state file.
213 * When we get any change, we check everything. So read each state file,
214 * then decide what to do.
216 * The core action is to write new metadata to all devices in the array.
217 * This is done at most once on any wakeup.
218 * After that we might:
219 * - update the array_state
220 * - set the role of some devices.
221 * - request a sync_action
225 #define ARRAY_DIRTY 1
227 static int read_and_act(struct active_array
*a
)
229 unsigned long long sync_completed
;
230 int check_degraded
= 0;
231 int check_reshape
= 0;
238 a
->next_state
= bad_word
;
239 a
->next_action
= bad_action
;
241 a
->curr_state
= read_state(a
->info
.state_fd
);
242 a
->curr_action
= read_action(a
->action_fd
);
243 if (a
->curr_state
!= clear
)
245 * In "clear" state, resync_start may wrongly be set to "0"
246 * when the kernel called md_clean but didn't remove the
247 * sysfs attributes yet
249 read_resync_start(a
->resync_start_fd
, &a
->info
.resync_start
);
250 sync_completed
= read_sync_completed(a
->sync_completed_fd
);
251 for (mdi
= a
->info
.devs
; mdi
; mdi
= mdi
->next
) {
254 if (mdi
->state_fd
>= 0) {
255 read_resync_start(mdi
->recovery_fd
,
256 &mdi
->recovery_start
);
257 mdi
->curr_state
= read_dev_state(mdi
->state_fd
);
261 gettimeofday(&tv
, NULL
);
262 dprintf("(%d): %ld.%06ld state:%s prev:%s action:%s prev: %s start:%llu\n",
263 a
->info
.container_member
,
264 tv
.tv_sec
, tv
.tv_usec
,
265 array_states
[a
->curr_state
],
266 array_states
[a
->prev_state
],
267 sync_actions
[a
->curr_action
],
268 sync_actions
[a
->prev_action
],
272 if ((a
->curr_state
== bad_word
|| a
->curr_state
<= inactive
) &&
273 a
->prev_state
> inactive
) {
274 /* array has been stopped */
275 a
->container
->ss
->set_array_state(a
, 1);
276 a
->next_state
= clear
;
279 if (a
->curr_state
== write_pending
) {
280 a
->container
->ss
->set_array_state(a
, 0);
281 a
->next_state
= active
;
284 if (a
->curr_state
== active_idle
) {
285 /* Set array to 'clean' FIRST, then mark clean
288 a
->next_state
= clean
;
291 if (a
->curr_state
== clean
) {
292 a
->container
->ss
->set_array_state(a
, 1);
294 if (a
->curr_state
== active
||
295 a
->curr_state
== suspended
)
297 if (a
->curr_state
== readonly
) {
298 /* Well, I'm ready to handle things. If readonly
299 * wasn't requested, transition to read-auto.
302 read_attr(buf
, sizeof(buf
), a
->metadata_fd
);
303 if (strncmp(buf
, "external:-", 10) == 0) {
304 /* explicit request for readonly array. Leave it alone */
307 if (a
->container
->ss
->set_array_state(a
, 2))
308 a
->next_state
= read_auto
; /* array is clean */
310 a
->next_state
= active
; /* Now active for recovery etc */
317 a
->curr_action
== idle
&&
318 a
->prev_action
== resync
) {
319 /* A resync has finished. The endpoint is recorded in
320 * 'sync_start'. We don't update the metadata
321 * until the array goes inactive or readonly though.
322 * Just check if we need to fiddle spares.
324 a
->container
->ss
->set_array_state(a
, a
->curr_state
<= clean
);
329 a
->curr_action
== idle
&&
330 a
->prev_action
== recover
) {
331 /* A recovery has finished. Some disks may be in sync now,
332 * and the array may no longer be degraded
334 for (mdi
= a
->info
.devs
; mdi
; mdi
= mdi
->next
) {
335 a
->container
->ss
->set_disk(a
, mdi
->disk
.raid_disk
,
337 if (! (mdi
->curr_state
& DS_INSYNC
))
341 if (count
!= a
->info
.array
.raid_disks
)
346 a
->curr_action
== reshape
&&
347 a
->prev_action
!= reshape
)
348 /* reshape was requested by mdadm. Need to see if
349 * new devices have been added. Manager does that
350 * when it sees check_reshape
354 /* Check for failures and if found:
355 * 1/ Record the failure in the metadata and unblock the device.
356 * FIXME update the kernel to stop notifying on failed drives when
357 * the array is readonly and we have cleared 'blocked'
358 * 2/ Try to remove the device if the array is writable, or can be
361 for (mdi
= a
->info
.devs
; mdi
; mdi
= mdi
->next
) {
362 if (mdi
->curr_state
& DS_FAULTY
) {
363 a
->container
->ss
->set_disk(a
, mdi
->disk
.raid_disk
,
366 if (mdi
->curr_state
& DS_BLOCKED
)
367 mdi
->next_state
|= DS_UNBLOCK
;
368 if (a
->curr_state
== read_auto
) {
369 a
->container
->ss
->set_array_state(a
, 0);
370 a
->next_state
= active
;
372 if (a
->curr_state
> readonly
)
373 mdi
->next_state
|= DS_REMOVE
;
377 /* Check for recovery checkpoint notifications. We need to be a
378 * minimum distance away from the last checkpoint to prevent
379 * over checkpointing. Note reshape checkpointing is handled
380 * in the second branch.
382 if (sync_completed
> a
->last_checkpoint
&&
383 sync_completed
- a
->last_checkpoint
> a
->info
.component_size
>> 4 &&
384 a
->curr_action
> reshape
) {
385 /* A (non-reshape) sync_action has reached a checkpoint.
386 * Record the updated position in the metadata
388 a
->last_checkpoint
= sync_completed
;
389 a
->container
->ss
->set_array_state(a
, a
->curr_state
<= clean
);
390 } else if ((a
->curr_action
== idle
&& a
->prev_action
== reshape
) ||
391 (a
->curr_action
== reshape
392 && sync_completed
> a
->last_checkpoint
) ) {
393 /* Reshape has progressed or completed so we need to
394 * update the array state - and possibly the array size
396 if (sync_completed
!= 0)
397 a
->last_checkpoint
= sync_completed
;
398 /* We might need to update last_checkpoint depending on
399 * the reason that reshape finished.
400 * if array reshape is really finished:
401 * set check point to the end, this allows
402 * set_array_state() to finalize reshape in metadata
403 * if reshape if broken: do not set checkpoint to the end
404 * this allows for reshape restart from checkpoint
406 if ((a
->curr_action
!= reshape
) &&
407 (a
->prev_action
== reshape
)) {
409 if ((sysfs_get_str(&a
->info
, NULL
,
412 sizeof(buf
)) >= 0) &&
413 strncmp(buf
, "none", 4) == 0)
414 a
->last_checkpoint
= a
->info
.component_size
;
416 a
->container
->ss
->set_array_state(a
, a
->curr_state
<= clean
);
417 a
->last_checkpoint
= sync_completed
;
420 if (sync_completed
> a
->last_checkpoint
)
421 a
->last_checkpoint
= sync_completed
;
423 if (sync_completed
>= a
->info
.component_size
)
424 a
->last_checkpoint
= 0;
426 a
->container
->ss
->sync_metadata(a
->container
);
427 dprintf("(%d): state:%s action:%s next(", a
->info
.container_member
,
428 array_states
[a
->curr_state
], sync_actions
[a
->curr_action
]);
430 /* Effect state changes in the array */
431 if (a
->next_state
!= bad_word
) {
432 dprintf_cont(" state:%s", array_states
[a
->next_state
]);
433 write_attr(array_states
[a
->next_state
], a
->info
.state_fd
);
435 if (a
->next_action
!= bad_action
) {
436 write_attr(sync_actions
[a
->next_action
], a
->action_fd
);
437 dprintf_cont(" action:%s", sync_actions
[a
->next_action
]);
439 for (mdi
= a
->info
.devs
; mdi
; mdi
= mdi
->next
) {
440 if (mdi
->next_state
& DS_UNBLOCK
) {
441 dprintf_cont(" %d:-blocked", mdi
->disk
.raid_disk
);
442 write_attr("-blocked", mdi
->state_fd
);
445 if ((mdi
->next_state
& DS_REMOVE
) && mdi
->state_fd
>= 0) {
448 /* The kernel may not be able to immediately remove the
449 * disk. In that case we wait a little while and
452 remove_result
= write_attr("remove", mdi
->state_fd
);
453 if (remove_result
> 0) {
454 dprintf_cont(" %d:removed", mdi
->disk
.raid_disk
);
455 close(mdi
->state_fd
);
456 close(mdi
->recovery_fd
);
461 if (mdi
->next_state
& DS_INSYNC
) {
462 write_attr("+in_sync", mdi
->state_fd
);
463 dprintf_cont(" %d:+in_sync", mdi
->disk
.raid_disk
);
466 dprintf_cont(" )\n");
468 /* move curr_ to prev_ */
469 a
->prev_state
= a
->curr_state
;
471 a
->prev_action
= a
->curr_action
;
473 for (mdi
= a
->info
.devs
; mdi
; mdi
= mdi
->next
) {
474 mdi
->prev_state
= mdi
->curr_state
;
478 if (check_degraded
|| check_reshape
) {
479 /* manager will do the actual check */
481 a
->check_degraded
= 1;
483 a
->check_reshape
= 1;
493 static struct mdinfo
*
494 find_device(struct active_array
*a
, int major
, int minor
)
498 for (mdi
= a
->info
.devs
; mdi
; mdi
= mdi
->next
)
499 if (mdi
->disk
.major
== major
&& mdi
->disk
.minor
== minor
)
505 static void reconcile_failed(struct active_array
*aa
, struct mdinfo
*failed
)
507 struct active_array
*a
;
508 struct mdinfo
*victim
;
510 for (a
= aa
; a
; a
= a
->next
) {
511 if (!a
->container
|| a
->to_remove
)
513 victim
= find_device(a
, failed
->disk
.major
, failed
->disk
.minor
);
517 if (!(victim
->curr_state
& DS_FAULTY
))
518 write_attr("faulty", victim
->state_fd
);
523 static void dprint_wake_reasons(fd_set
*fds
)
531 fprintf(stderr
, "monitor: wake ( ");
532 for (i
= 0; i
< FD_SETSIZE
; i
++) {
533 if (FD_ISSET(i
, fds
)) {
534 sprintf(proc_path
, "/proc/%d/fd/%d",
537 rv
= readlink(proc_path
, link
, sizeof(link
) - 1);
539 fprintf(stderr
, "%d:unknown ", i
);
543 basename
= strrchr(link
, '/');
544 fprintf(stderr
, "%d:%s ",
545 i
, basename
? ++basename
: link
);
548 fprintf(stderr
, ")\n");
552 int monitor_loop_cnt
;
554 static int wait_and_act(struct supertype
*container
, int nowait
)
558 struct active_array
**aap
= &container
->arrays
;
559 struct active_array
*a
, **ap
;
562 static unsigned int dirty_arrays
= ~0; /* start at some non-zero value */
566 for (ap
= aap
; *ap
;) {
568 /* once an array has been deactivated we want to
569 * ask the manager to discard it.
571 if (!a
->container
|| a
->to_remove
) {
583 add_fd(&rfds
, &maxfd
, a
->info
.state_fd
);
584 add_fd(&rfds
, &maxfd
, a
->action_fd
);
585 add_fd(&rfds
, &maxfd
, a
->sync_completed_fd
);
586 for (mdi
= a
->info
.devs
; mdi
; mdi
= mdi
->next
)
587 add_fd(&rfds
, &maxfd
, mdi
->state_fd
);
592 if (manager_ready
&& (*aap
== NULL
|| (sigterm
&& !dirty_arrays
))) {
593 /* No interesting arrays, or we have been told to
594 * terminate and everything is clean. Lets see about
595 * exiting. Note that blocking at this point is not a
596 * problem as there are no active arrays, there is
597 * nothing that we need to be ready to do.
601 fd
= open_dev_excl(container
->devnm
);
603 fd
= open_dev_flags(container
->devnm
, O_RDONLY
|O_EXCL
);
604 if (fd
>= 0 || errno
!= EBUSY
) {
605 /* OK, we are safe to leave */
606 if (sigterm
&& !dirty_arrays
)
607 dprintf("caught sigterm, all clean... exiting\n");
609 dprintf("no arrays to monitor... exiting\n");
611 /* On SIGTERM, someone (the take-over mdmon) will
614 remove_pidfile(container
->devnm
);
627 if (*aap
== NULL
|| container
->retry_soon
) {
628 /* just waiting to get O_EXCL access */
630 ts
.tv_nsec
= 20000000ULL;
632 sigprocmask(SIG_UNBLOCK
, NULL
, &set
);
633 sigdelset(&set
, SIGUSR1
);
634 monitor_loop_cnt
|= 1;
635 rv
= pselect(maxfd
+1, NULL
, NULL
, &rfds
, &ts
, &set
);
636 monitor_loop_cnt
+= 1;
638 if (errno
== EINTR
) {
640 dprintf("monitor: caught signal\n");
642 dprintf("monitor: error %d in pselect\n",
647 dprint_wake_reasons(&rfds
);
649 container
->retry_soon
= 0;
653 struct metadata_update
*this;
655 for (this = update_queue
; this ; this = this->next
)
656 container
->ss
->process_update(container
, this);
658 update_queue_handled
= update_queue
;
661 container
->ss
->sync_metadata(container
);
666 for (a
= *aap
; a
; a
= a
->next
) {
668 if (a
->replaces
&& !discard_this
) {
669 struct active_array
**ap
;
670 for (ap
= &a
->next
; *ap
&& *ap
!= a
->replaces
;
675 discard_this
= a
->replaces
;
677 /* FIXME check if device->state_fd need to be cleared?*/
680 if (a
->container
&& !a
->to_remove
) {
681 int ret
= read_and_act(a
);
683 dirty_arrays
+= !!(ret
& ARRAY_DIRTY
);
684 /* when terminating stop manipulating the array after it
685 * is clean, but make sure read_and_act() is given a
686 * chance to handle 'active_idle'
688 if (sigterm
&& !(ret
& ARRAY_DIRTY
))
689 a
->container
= NULL
; /* stop touching this array */
690 if (ret
& ARRAY_BUSY
)
691 container
->retry_soon
= 1;
695 /* propagate failures across container members */
696 for (a
= *aap
; a
; a
= a
->next
) {
697 if (!a
->container
|| a
->to_remove
)
699 for (mdi
= a
->info
.devs
; mdi
; mdi
= mdi
->next
)
700 if (mdi
->curr_state
& DS_FAULTY
)
701 reconcile_failed(*aap
, mdi
);
707 void do_monitor(struct supertype
*container
)
712 rv
= wait_and_act(container
, first
);