]>
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
39 static int write_attr(char *attr
, int fd
)
41 return write(fd
, attr
, strlen(attr
));
44 static void add_fd(fd_set
*fds
, int *maxfd
, int fd
)
49 if (fstat(fd
, &st
) == -1) {
50 dprintf("Invalid fd %d\n", fd
);
53 if (st
.st_nlink
== 0) {
54 dprintf("fd %d was deleted\n", fd
);
62 static int read_attr(char *buf
, int len
, int fd
)
71 n
= read(fd
, buf
, len
- 1);
83 static void read_resync_start(int fd
, unsigned long long *v
)
88 n
= read_attr(buf
, 30, fd
);
90 dprintf("Failed to read resync_start (%d)\n", fd
);
93 if (strncmp(buf
, "none", 4) == 0)
96 *v
= strtoull(buf
, NULL
, 10);
99 static unsigned long long read_sync_completed(int fd
)
101 unsigned long long val
;
106 n
= read_attr(buf
, 50, fd
);
111 val
= strtoull(buf
, &ep
, 0);
112 if (ep
== buf
|| (*ep
!= 0 && *ep
!= '\n' && *ep
!= ' '))
117 static enum array_state
read_state(int fd
)
120 int n
= read_attr(buf
, 20, fd
);
124 return (enum array_state
) sysfs_match_word(buf
, array_states
);
127 static enum sync_action
read_action( int fd
)
130 int n
= read_attr(buf
, 20, fd
);
134 return (enum sync_action
) sysfs_match_word(buf
, sync_actions
);
137 int read_dev_state(int fd
)
140 int n
= read_attr(buf
, sizeof(buf
), fd
);
149 if (sysfs_attr_match(cp
, "faulty"))
151 if (sysfs_attr_match(cp
, "in_sync"))
153 if (sysfs_attr_match(cp
, "write_mostly"))
154 rv
|= DS_WRITE_MOSTLY
;
155 if (sysfs_attr_match(cp
, "spare"))
157 if (sysfs_attr_match(cp
, "blocked"))
159 cp
= strchr(cp
, ',');
166 int process_ubb(struct active_array
*a
, struct mdinfo
*mdi
, const unsigned long
167 long sector
, const int length
, const char *buf
,
170 struct superswitch
*ss
= a
->container
->ss
;
173 * record bad block in metadata first, then acknowledge it to the driver
176 if ((ss
->record_bad_block(a
, mdi
->disk
.raid_disk
, sector
, length
)) &&
177 (write(mdi
->bb_fd
, buf
, buf_len
) == buf_len
))
181 * failed to store or acknowledge bad block, switch of bad block support
182 * to get it out of blocked state
184 sysfs_set_str(&a
->info
, mdi
, "state", "-external_bbl");
188 int compare_bb(struct active_array
*a
, struct mdinfo
*mdi
, const unsigned long
189 long sector
, const unsigned int length
, void *arg
)
191 struct superswitch
*ss
= a
->container
->ss
;
192 struct md_bb
*bb
= (struct md_bb
*) arg
;
196 for (i
= 0; i
< bb
->count
; i
++) {
197 unsigned long long start
= bb
->entries
[i
].sector
;
198 unsigned long long len
= bb
->entries
[i
].length
;
201 * bad block in metadata exactly matches bad block in kernel
202 * list, just remove it from a list
204 if ((start
== sector
) && (len
== length
)) {
205 if (i
< bb
->count
- 1)
206 bb
->entries
[i
] = bb
->entries
[bb
->count
- 1];
212 * bad block in metadata spans bad block in kernel list,
213 * clear it and record new bad block
215 if ((sector
>= start
) && (sector
+ length
<= start
+ len
)) {
216 ss
->clear_bad_block(a
, mdi
->disk
.raid_disk
, start
, len
);
221 /* record all bad blocks not in metadata list */
222 if (record
&& (ss
->record_bad_block(a
, mdi
->disk
.raid_disk
, sector
,
224 sysfs_set_str(&a
->info
, mdi
, "state", "-external_bbl");
231 static int read_bb_file(int fd
, struct active_array
*a
, struct mdinfo
*mdi
,
232 enum bb_action action
, void *arg
)
240 int preserve_pos
= (action
== RECORD_BB
? 0 : 1);
242 if (lseek(fd
, 0, SEEK_SET
) == (off_t
) -1)
247 n
= read(fd
, buf
+ pos
, sizeof(buf
) - 1 - pos
);
256 unsigned long long sector
;
263 /* kernel sysfs file format: "sector length\n" */
264 matched
= sscanf(buf
+ off
, "%llu %d%c%n", §or
,
265 &length
, &newline
, &consumed
);
266 if ((matched
!= 3) && (off
> 0)) {
267 /* truncated entry, read again */
269 pos
= sizeof(buf
) - off
- 1;
270 memmove(buf
, buf
+ off
, pos
);
272 if (lseek(fd
, 0, SEEK_SET
) ==
286 if (action
== RECORD_BB
)
287 rc
= process_ubb(a
, mdi
, sector
, length
,
288 buf
+ off
, consumed
);
289 else if (action
== COMPARE_BB
)
290 rc
= compare_bb(a
, mdi
, sector
, length
, arg
);
299 } while (read_again
);
304 static int process_dev_ubb(struct active_array
*a
, struct mdinfo
*mdi
)
306 return read_bb_file(mdi
->ubb_fd
, a
, mdi
, RECORD_BB
, NULL
);
309 static int check_for_cleared_bb(struct active_array
*a
, struct mdinfo
*mdi
)
311 struct superswitch
*ss
= a
->container
->ss
;
316 * Get a list of bad blocks for an array, then read list of
317 * acknowledged bad blocks from kernel and compare it against metadata
318 * list, clear all bad blocks remaining in metadata list
320 bb
= ss
->get_bad_blocks(a
, mdi
->disk
.raid_disk
);
324 if (read_bb_file(mdi
->bb_fd
, a
, mdi
, COMPARE_BB
, bb
) < 0)
327 for (i
= 0; i
< bb
->count
; i
++) {
328 unsigned long long sector
= bb
->entries
[i
].sector
;
329 int length
= bb
->entries
[i
].length
;
331 ss
->clear_bad_block(a
, mdi
->disk
.raid_disk
, sector
, length
);
337 static void signal_manager(void)
339 /* tgkill(getpid(), mon_tid, SIGUSR1); */
341 syscall(SYS_tgkill
, pid
, mgr_tid
, SIGUSR1
);
344 /* Monitor a set of active md arrays - all of which share the
345 * same metadata - and respond to events that require
348 * New arrays are detected by another thread which allocates
349 * required memory and attaches the data structure to our list.
353 * This is detected by array_state going to 'clear' or 'inactive'.
354 * while we thought it was active.
355 * Response is to mark metadata as clean and 'clear' the array(??)
357 * array_state if 'write-pending'
358 * We mark metadata as 'dirty' then set array to 'active'.
360 * Either ignore, or mark clean, then mark metadata as clean.
363 * detected by rd-N/state reporting "faulty"
364 * mark device as 'failed' in metadata, let the kernel release the
365 * device by writing '-blocked' to rd/state, and finally write 'remove' to
366 * rd/state. Before a disk can be replaced it must be failed and removed
367 * from all container members, this will be preemptive for the other
371 * sync_action was 'resync' and becomes 'idle' and resync_start becomes
373 * Notify metadata that sync is complete.
376 * sync_action changes from 'recover' to 'idle'
377 * Check each device state and mark metadata if 'faulty' or 'in_sync'.
380 * This only happens on finding a new array... mdadm will have set
381 * 'resync_start' to the correct value. If 'resync_start' indicates that an
382 * resync needs to occur set the array to the 'active' state rather than the
383 * initial read-auto state.
387 * We wait for a change (poll/select) on array_state, sync_action, and
388 * each rd-X/state file.
389 * When we get any change, we check everything. So read each state file,
390 * then decide what to do.
392 * The core action is to write new metadata to all devices in the array.
393 * This is done at most once on any wakeup.
394 * After that we might:
395 * - update the array_state
396 * - set the role of some devices.
397 * - request a sync_action
401 #define ARRAY_DIRTY 1
403 static int read_and_act(struct active_array
*a
, fd_set
*fds
)
405 unsigned long long sync_completed
;
406 int check_degraded
= 0;
407 int check_reshape
= 0;
414 a
->next_state
= bad_word
;
415 a
->next_action
= bad_action
;
417 a
->curr_state
= read_state(a
->info
.state_fd
);
418 a
->curr_action
= read_action(a
->action_fd
);
419 if (a
->curr_state
!= clear
)
421 * In "clear" state, resync_start may wrongly be set to "0"
422 * when the kernel called md_clean but didn't remove the
423 * sysfs attributes yet
425 read_resync_start(a
->resync_start_fd
, &a
->info
.resync_start
);
426 sync_completed
= read_sync_completed(a
->sync_completed_fd
);
427 for (mdi
= a
->info
.devs
; mdi
; mdi
= mdi
->next
) {
430 if (mdi
->state_fd
>= 0) {
431 read_resync_start(mdi
->recovery_fd
,
432 &mdi
->recovery_start
);
433 mdi
->curr_state
= read_dev_state(mdi
->state_fd
);
436 * If array is blocked and metadata handler is able to handle
437 * BB, check if you can acknowledge them to md driver. If
438 * successful, clear faulty state and unblock the array.
440 if ((mdi
->curr_state
& DS_BLOCKED
) &&
441 a
->container
->ss
->record_bad_block
&&
442 (process_dev_ubb(a
, mdi
) > 0)) {
443 mdi
->next_state
|= DS_UNBLOCK
;
445 if (FD_ISSET(mdi
->bb_fd
, fds
))
446 check_for_cleared_bb(a
, mdi
);
449 gettimeofday(&tv
, NULL
);
450 dprintf("(%d): %ld.%06ld state:%s prev:%s action:%s prev: %s start:%llu\n",
451 a
->info
.container_member
,
452 tv
.tv_sec
, tv
.tv_usec
,
453 array_states
[a
->curr_state
],
454 array_states
[a
->prev_state
],
455 sync_actions
[a
->curr_action
],
456 sync_actions
[a
->prev_action
],
460 if ((a
->curr_state
== bad_word
|| a
->curr_state
<= inactive
) &&
461 a
->prev_state
> inactive
) {
462 /* array has been stopped */
463 a
->container
->ss
->set_array_state(a
, 1);
464 a
->next_state
= clear
;
467 if (a
->curr_state
== write_pending
) {
468 a
->container
->ss
->set_array_state(a
, 0);
469 a
->next_state
= active
;
472 if (a
->curr_state
== active_idle
) {
473 /* Set array to 'clean' FIRST, then mark clean
476 a
->next_state
= clean
;
479 if (a
->curr_state
== clean
) {
480 a
->container
->ss
->set_array_state(a
, 1);
482 if (a
->curr_state
== active
||
483 a
->curr_state
== suspended
)
485 if (a
->curr_state
== readonly
) {
486 /* Well, I'm ready to handle things. If readonly
487 * wasn't requested, transition to read-auto.
490 read_attr(buf
, sizeof(buf
), a
->metadata_fd
);
491 if (strncmp(buf
, "external:-", 10) == 0) {
492 /* explicit request for readonly array. Leave it alone */
495 if (a
->container
->ss
->set_array_state(a
, 2))
496 a
->next_state
= read_auto
; /* array is clean */
498 a
->next_state
= active
; /* Now active for recovery etc */
505 a
->curr_action
== idle
&&
506 a
->prev_action
== resync
) {
507 /* A resync has finished. The endpoint is recorded in
508 * 'sync_start'. We don't update the metadata
509 * until the array goes inactive or readonly though.
510 * Just check if we need to fiddle spares.
512 a
->container
->ss
->set_array_state(a
, a
->curr_state
<= clean
);
517 a
->curr_action
== idle
&&
518 a
->prev_action
== recover
) {
519 /* A recovery has finished. Some disks may be in sync now,
520 * and the array may no longer be degraded
522 for (mdi
= a
->info
.devs
; mdi
; mdi
= mdi
->next
) {
523 a
->container
->ss
->set_disk(a
, mdi
->disk
.raid_disk
,
525 if (! (mdi
->curr_state
& DS_INSYNC
))
529 if (count
!= a
->info
.array
.raid_disks
)
534 a
->curr_action
== reshape
&&
535 a
->prev_action
!= reshape
)
536 /* reshape was requested by mdadm. Need to see if
537 * new devices have been added. Manager does that
538 * when it sees check_reshape
542 /* Check for failures and if found:
543 * 1/ Record the failure in the metadata and unblock the device.
544 * FIXME update the kernel to stop notifying on failed drives when
545 * the array is readonly and we have cleared 'blocked'
546 * 2/ Try to remove the device if the array is writable, or can be
549 for (mdi
= a
->info
.devs
; mdi
; mdi
= mdi
->next
) {
550 if (mdi
->curr_state
& DS_FAULTY
) {
551 a
->container
->ss
->set_disk(a
, mdi
->disk
.raid_disk
,
554 if (mdi
->curr_state
& DS_BLOCKED
)
555 mdi
->next_state
|= DS_UNBLOCK
;
556 if (a
->curr_state
== read_auto
) {
557 a
->container
->ss
->set_array_state(a
, 0);
558 a
->next_state
= active
;
560 if (a
->curr_state
> readonly
)
561 mdi
->next_state
|= DS_REMOVE
;
565 /* Check for recovery checkpoint notifications. We need to be a
566 * minimum distance away from the last checkpoint to prevent
567 * over checkpointing. Note reshape checkpointing is handled
568 * in the second branch.
570 if (sync_completed
> a
->last_checkpoint
&&
571 sync_completed
- a
->last_checkpoint
> a
->info
.component_size
>> 4 &&
572 a
->curr_action
> reshape
) {
573 /* A (non-reshape) sync_action has reached a checkpoint.
574 * Record the updated position in the metadata
576 a
->last_checkpoint
= sync_completed
;
577 a
->container
->ss
->set_array_state(a
, a
->curr_state
<= clean
);
578 } else if ((a
->curr_action
== idle
&& a
->prev_action
== reshape
) ||
579 (a
->curr_action
== reshape
&&
580 sync_completed
> a
->last_checkpoint
)) {
581 /* Reshape has progressed or completed so we need to
582 * update the array state - and possibly the array size
584 if (sync_completed
!= 0)
585 a
->last_checkpoint
= sync_completed
;
586 /* We might need to update last_checkpoint depending on
587 * the reason that reshape finished.
588 * if array reshape is really finished:
589 * set check point to the end, this allows
590 * set_array_state() to finalize reshape in metadata
591 * if reshape if broken: do not set checkpoint to the end
592 * this allows for reshape restart from checkpoint
594 if ((a
->curr_action
!= reshape
) &&
595 (a
->prev_action
== reshape
)) {
597 if ((sysfs_get_str(&a
->info
, NULL
,
600 sizeof(buf
)) >= 0) &&
601 strncmp(buf
, "none", 4) == 0)
602 a
->last_checkpoint
= a
->info
.component_size
;
604 a
->container
->ss
->set_array_state(a
, a
->curr_state
<= clean
);
605 a
->last_checkpoint
= sync_completed
;
608 if (sync_completed
> a
->last_checkpoint
)
609 a
->last_checkpoint
= sync_completed
;
611 if (sync_completed
>= a
->info
.component_size
)
612 a
->last_checkpoint
= 0;
614 a
->container
->ss
->sync_metadata(a
->container
);
615 dprintf("(%d): state:%s action:%s next(", a
->info
.container_member
,
616 array_states
[a
->curr_state
], sync_actions
[a
->curr_action
]);
618 /* Effect state changes in the array */
619 if (a
->next_state
!= bad_word
) {
620 dprintf_cont(" state:%s", array_states
[a
->next_state
]);
621 write_attr(array_states
[a
->next_state
], a
->info
.state_fd
);
623 if (a
->next_action
!= bad_action
) {
624 write_attr(sync_actions
[a
->next_action
], a
->action_fd
);
625 dprintf_cont(" action:%s", sync_actions
[a
->next_action
]);
627 for (mdi
= a
->info
.devs
; mdi
; mdi
= mdi
->next
) {
628 if (mdi
->next_state
& DS_UNBLOCK
) {
629 dprintf_cont(" %d:-blocked", mdi
->disk
.raid_disk
);
630 write_attr("-blocked", mdi
->state_fd
);
633 if ((mdi
->next_state
& DS_REMOVE
) && mdi
->state_fd
>= 0) {
636 /* The kernel may not be able to immediately remove the
637 * disk. In that case we wait a little while and
640 remove_result
= write_attr("remove", mdi
->state_fd
);
641 if (remove_result
> 0) {
642 dprintf_cont(" %d:removed", mdi
->disk
.raid_disk
);
643 close(mdi
->state_fd
);
644 close(mdi
->recovery_fd
);
651 if (mdi
->next_state
& DS_INSYNC
) {
652 write_attr("+in_sync", mdi
->state_fd
);
653 dprintf_cont(" %d:+in_sync", mdi
->disk
.raid_disk
);
656 dprintf_cont(" )\n");
658 /* move curr_ to prev_ */
659 a
->prev_state
= a
->curr_state
;
661 a
->prev_action
= a
->curr_action
;
663 for (mdi
= a
->info
.devs
; mdi
; mdi
= mdi
->next
) {
664 mdi
->prev_state
= mdi
->curr_state
;
668 if (check_degraded
|| check_reshape
) {
669 /* manager will do the actual check */
671 a
->check_degraded
= 1;
673 a
->check_reshape
= 1;
683 static struct mdinfo
*
684 find_device(struct active_array
*a
, int major
, int minor
)
688 for (mdi
= a
->info
.devs
; mdi
; mdi
= mdi
->next
)
689 if (mdi
->disk
.major
== major
&& mdi
->disk
.minor
== minor
)
695 static void reconcile_failed(struct active_array
*aa
, struct mdinfo
*failed
)
697 struct active_array
*a
;
698 struct mdinfo
*victim
;
700 for (a
= aa
; a
; a
= a
->next
) {
701 if (!a
->container
|| a
->to_remove
)
703 victim
= find_device(a
, failed
->disk
.major
, failed
->disk
.minor
);
707 if (!(victim
->curr_state
& DS_FAULTY
))
708 write_attr("faulty", victim
->state_fd
);
713 static void dprint_wake_reasons(fd_set
*fds
)
721 fprintf(stderr
, "monitor: wake ( ");
722 for (i
= 0; i
< FD_SETSIZE
; i
++) {
723 if (FD_ISSET(i
, fds
)) {
724 sprintf(proc_path
, "/proc/%d/fd/%d",
727 rv
= readlink(proc_path
, link
, sizeof(link
) - 1);
729 fprintf(stderr
, "%d:unknown ", i
);
733 basename
= strrchr(link
, '/');
734 fprintf(stderr
, "%d:%s ",
735 i
, basename
? ++basename
: link
);
738 fprintf(stderr
, ")\n");
742 int monitor_loop_cnt
;
744 static int wait_and_act(struct supertype
*container
, int nowait
)
748 struct active_array
**aap
= &container
->arrays
;
749 struct active_array
*a
, **ap
;
752 static unsigned int dirty_arrays
= ~0; /* start at some non-zero value */
756 for (ap
= aap
; *ap
;) {
758 /* once an array has been deactivated we want to
759 * ask the manager to discard it.
761 if (!a
->container
|| a
->to_remove
) {
773 add_fd(&rfds
, &maxfd
, a
->info
.state_fd
);
774 add_fd(&rfds
, &maxfd
, a
->action_fd
);
775 add_fd(&rfds
, &maxfd
, a
->sync_completed_fd
);
776 for (mdi
= a
->info
.devs
; mdi
; mdi
= mdi
->next
) {
777 add_fd(&rfds
, &maxfd
, mdi
->state_fd
);
778 add_fd(&rfds
, &maxfd
, mdi
->bb_fd
);
779 add_fd(&rfds
, &maxfd
, mdi
->ubb_fd
);
785 if (manager_ready
&& (*aap
== NULL
|| (sigterm
&& !dirty_arrays
))) {
786 /* No interesting arrays, or we have been told to
787 * terminate and everything is clean. Lets see about
788 * exiting. Note that blocking at this point is not a
789 * problem as there are no active arrays, there is
790 * nothing that we need to be ready to do.
794 fd
= open_dev_excl(container
->devnm
);
796 fd
= open_dev_flags(container
->devnm
, O_RDONLY
|O_EXCL
);
797 if (fd
>= 0 || errno
!= EBUSY
) {
798 /* OK, we are safe to leave */
799 if (sigterm
&& !dirty_arrays
)
800 dprintf("caught sigterm, all clean... exiting\n");
802 dprintf("no arrays to monitor... exiting\n");
804 /* On SIGTERM, someone (the take-over mdmon) will
807 remove_pidfile(container
->devnm
);
820 if (*aap
== NULL
|| container
->retry_soon
) {
821 /* just waiting to get O_EXCL access */
823 ts
.tv_nsec
= 20000000ULL;
825 sigprocmask(SIG_UNBLOCK
, NULL
, &set
);
826 sigdelset(&set
, SIGUSR1
);
827 monitor_loop_cnt
|= 1;
828 rv
= pselect(maxfd
+1, NULL
, NULL
, &rfds
, &ts
, &set
);
829 monitor_loop_cnt
+= 1;
831 if (errno
== EINTR
) {
834 dprintf("monitor: caught signal\n");
836 dprintf("monitor: error %d in pselect\n",
841 dprint_wake_reasons(&rfds
);
843 container
->retry_soon
= 0;
847 struct metadata_update
*this;
849 for (this = update_queue
; this ; this = this->next
)
850 container
->ss
->process_update(container
, this);
852 update_queue_handled
= update_queue
;
855 container
->ss
->sync_metadata(container
);
860 for (a
= *aap
; a
; a
= a
->next
) {
862 if (a
->replaces
&& !discard_this
) {
863 struct active_array
**ap
;
864 for (ap
= &a
->next
; *ap
&& *ap
!= a
->replaces
;
869 discard_this
= a
->replaces
;
871 /* FIXME check if device->state_fd need to be cleared?*/
874 if (a
->container
&& !a
->to_remove
) {
875 int ret
= read_and_act(a
, &rfds
);
877 dirty_arrays
+= !!(ret
& ARRAY_DIRTY
);
878 /* when terminating stop manipulating the array after it
879 * is clean, but make sure read_and_act() is given a
880 * chance to handle 'active_idle'
882 if (sigterm
&& !(ret
& ARRAY_DIRTY
))
883 a
->container
= NULL
; /* stop touching this array */
884 if (ret
& ARRAY_BUSY
)
885 container
->retry_soon
= 1;
889 /* propagate failures across container members */
890 for (a
= *aap
; a
; a
= a
->next
) {
891 if (!a
->container
|| a
->to_remove
)
893 for (mdi
= a
->info
.devs
; mdi
; mdi
= mdi
->next
)
894 if (mdi
->curr_state
& DS_FAULTY
)
895 reconcile_failed(*aap
, mdi
);
901 void do_monitor(struct supertype
*container
)
906 rv
= wait_and_act(container
, first
);