]>
git.ipfire.org Git - thirdparty/mdadm.git/blob - managemon.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.
22 * The management thread for monitoring active md arrays.
23 * This thread does things which might block such as memory
27 * - Find out about new arrays in this container.
28 * Allocate the data structures and open the files.
30 * For this we watch /proc/mdstat and find new arrays with
31 * metadata type that confirms sharing. e.g. "md4"
32 * When we find a new array we slip it into the list of
33 * arrays and signal 'monitor' by writing to a pipe.
35 * - Respond to reshape requests by allocating new data structures
36 * and opening new files.
38 * These come as a change to raid_disks. We allocate a new
39 * version of the data structures and slip it into the list.
40 * 'monitor' will notice and release the old version.
41 * Changes to level, chunksize, layout.. do not need re-allocation.
42 * Reductions in raid_disks don't really either, but we handle
43 * them the same way for consistency.
45 * - When a device is added to the container, we add it to the metadata
48 * - Deal with degraded array
49 * We only do this when first noticing the array is degraded.
50 * This can be when we first see the array, when sync completes or
51 * when recovery completes.
53 * Check if number of failed devices suggests recovery is needed, and
55 * Ask metadata to allocate a spare device
56 * Add device as not in_sync and give a role
58 * Open sysfs files and pass to monitor.
59 * Make sure that monitor Starts recovery....
61 * - Pass on metadata updates from external programs such as
62 * mdadm creating a new array.
65 * It might involve adding a new array or changing the status of
66 * a spare, or any reconfig that the kernel doesn't get involved in.
68 * The required updates are received via a named pipe. There will
69 * be one named pipe for each container. Each message contains a
70 * sync marker: 0x5a5aa5a5, A byte count, and the message. This is
71 * passed to the metadata handler which will interpret and process it.
72 * For 'DDF' messages are internal data blocks with the leading
73 * 'magic number' signifying what sort of data it is.
78 * We select on /proc/mdstat and the named pipe.
79 * We create new arrays or updated version of arrays and slip
80 * them into the head of the list, then signal 'monitor' via a pipe write.
81 * 'monitor' will notice and place the old array on a return list.
82 * Metadata updates are placed on a queue just like they arrive
83 * from the named pipe.
85 * When new arrays are found based on correct metadata string, we
86 * need to identify them with an entry in the metadata. Maybe we require
87 * the metadata to be mdX/NN when NN is the index into an appropriate table.
93 * - Watch for spares to be added to the container, and write updated
95 * - Watch for new arrays using this container, confirm they match metadata
96 * and if so, start monitoring them
97 * - Watch for spares being added to monitored arrays. This shouldn't
98 * happen, as we should do all the adding. Just remove them.
99 * - Watch for change in raid-disks, chunk-size, etc. Update metadata and
107 #include <sys/syscall.h>
108 #include <sys/socket.h>
111 static void close_aa(struct active_array
*aa
)
115 for (d
= aa
->info
.devs
; d
; d
= d
->next
) {
116 close(d
->recovery_fd
);
120 if (aa
->action_fd
>= 0)
121 close(aa
->action_fd
);
122 if (aa
->info
.state_fd
>= 0)
123 close(aa
->info
.state_fd
);
124 if (aa
->resync_start_fd
>= 0)
125 close(aa
->resync_start_fd
);
126 if (aa
->metadata_fd
>= 0)
127 close(aa
->metadata_fd
);
128 if (aa
->sync_completed_fd
>= 0)
129 close(aa
->sync_completed_fd
);
132 static void free_aa(struct active_array
*aa
)
134 /* Note that this doesn't close fds if they are being used
135 * by a clone. ->container will be set for a clone
137 dprintf("sys_name: %s\n", aa
->info
.sys_name
);
140 while (aa
->info
.devs
) {
141 struct mdinfo
*d
= aa
->info
.devs
;
142 aa
->info
.devs
= d
->next
;
148 static struct active_array
*duplicate_aa(struct active_array
*aa
)
150 struct active_array
*newa
= xmalloc(sizeof(*newa
));
151 struct mdinfo
**dp1
, **dp2
;
155 newa
->replaces
= NULL
;
156 newa
->info
.next
= NULL
;
158 dp2
= &newa
->info
.devs
;
160 for (dp1
= &aa
->info
.devs
; *dp1
; dp1
= &(*dp1
)->next
) {
162 if ((*dp1
)->state_fd
< 0)
165 d
= xmalloc(sizeof(*d
));
175 static void wakeup_monitor(void)
177 /* tgkill(getpid(), mon_tid, SIGUSR1); */
179 syscall(SYS_tgkill
, pid
, mon_tid
, SIGUSR1
);
182 static void remove_old(void)
185 discard_this
->next
= NULL
;
186 free_aa(discard_this
);
187 if (pending_discard
== discard_this
)
188 pending_discard
= NULL
;
194 static void replace_array(struct supertype
*container
,
195 struct active_array
*old
,
196 struct active_array
*new)
198 /* To replace an array, we add it to the top of the list
199 * marked with ->replaces to point to the original.
200 * 'monitor' will take the original out of the list
201 * and put it on 'discard_this'. We take it from there
205 while (pending_discard
) {
206 while (discard_this
== NULL
)
210 pending_discard
= old
;
212 new->next
= container
->arrays
;
213 container
->arrays
= new;
217 struct metadata_update
*update_queue
= NULL
;
218 struct metadata_update
*update_queue_handled
= NULL
;
219 struct metadata_update
*update_queue_pending
= NULL
;
221 static void free_updates(struct metadata_update
**update
)
224 struct metadata_update
*this = *update
;
225 void **space_list
= this->space_list
;
227 *update
= this->next
;
231 void *space
= space_list
;
232 space_list
= *space_list
;
239 void check_update_queue(struct supertype
*container
)
241 free_updates(&update_queue_handled
);
243 if (update_queue
== NULL
&&
244 update_queue_pending
) {
245 update_queue
= update_queue_pending
;
246 update_queue_pending
= NULL
;
251 static void queue_metadata_update(struct metadata_update
*mu
)
253 struct metadata_update
**qp
;
255 qp
= &update_queue_pending
;
257 qp
= & ((*qp
)->next
);
261 static void add_disk_to_container(struct supertype
*st
, struct mdinfo
*sd
)
265 struct supertype
*st2
;
266 struct metadata_update
*update
= NULL
;
268 mdu_disk_info_t dk
= {
270 .major
= sd
->disk
.major
,
271 .minor
= sd
->disk
.minor
,
276 dprintf("add %d:%d to container\n", sd
->disk
.major
, sd
->disk
.minor
);
281 sprintf(nm
, "%d:%d", sd
->disk
.major
, sd
->disk
.minor
);
282 dfd
= dev_open(nm
, O_RDWR
);
286 /* Check the metadata and see if it is already part of this
290 if (st2
->ss
->load_super(st2
, dfd
, NULL
) == 0) {
291 st2
->ss
->getinfo_super(st2
, &info
, NULL
);
292 if (st
->ss
->compare_super(st
, st2
) == 0 &&
293 info
.disk
.raid_disk
>= 0) {
294 /* Looks like a good member of array.
296 * mdadm will incorporate any parts into
299 st2
->ss
->free_super(st2
);
303 st2
->ss
->free_super(st2
);
305 st
->update_tail
= &update
;
306 st
->ss
->add_to_super(st
, &dk
, dfd
, NULL
, INVALID_SECTORS
);
307 st
->ss
->write_init_super(st
);
308 queue_metadata_update(update
);
309 st
->update_tail
= NULL
;
313 * Create and queue update structure about the removed disks.
314 * The update is prepared by super type handler and passed to the monitor
317 static void remove_disk_from_container(struct supertype
*st
, struct mdinfo
*sd
)
319 struct metadata_update
*update
= NULL
;
320 mdu_disk_info_t dk
= {
322 .major
= sd
->disk
.major
,
323 .minor
= sd
->disk
.minor
,
327 dprintf("remove %d:%d from container\n",
328 sd
->disk
.major
, sd
->disk
.minor
);
330 st
->update_tail
= &update
;
331 st
->ss
->remove_from_super(st
, &dk
);
332 /* FIXME this write_init_super shouldn't be here.
333 * We have it after add_to_super to write to new device,
334 * but with 'remove' we don't ant to write to that device!
336 st
->ss
->write_init_super(st
);
337 queue_metadata_update(update
);
338 st
->update_tail
= NULL
;
341 static void manage_container(struct mdstat_ent
*mdstat
,
342 struct supertype
*container
)
344 /* Of interest here are:
345 * - if a new device has been added to the container, we
346 * add it to the array ignoring any metadata on it.
347 * - if a device has been removed from the container, we
348 * remove it from the device list and update the metadata.
349 * FIXME should we look for compatible metadata and take hints
350 * about spare assignment.... probably not.
352 if (mdstat
->devcnt
!= container
->devcnt
) {
353 struct mdinfo
**cdp
, *cd
, *di
, *mdi
;
356 /* read /sys/block/NAME/md/dev-??/block/dev to find out
357 * what is there, and compare with container->info.devs
358 * To see what is removed and what is added.
359 * These need to be remove from, or added to, the array
361 mdi
= sysfs_read(-1, mdstat
->devnm
, GET_DEVS
);
363 /* invalidate the current count so we can try again */
364 container
->devcnt
= -1;
368 /* check for removals */
369 for (cdp
= &container
->devs
; *cdp
; ) {
371 for (di
= mdi
->devs
; di
; di
= di
->next
)
372 if (di
->disk
.major
== (*cdp
)->disk
.major
&&
373 di
->disk
.minor
== (*cdp
)->disk
.minor
) {
380 remove_disk_from_container(container
, cd
);
386 /* check for additions */
387 for (di
= mdi
->devs
; di
; di
= di
->next
) {
388 for (cd
= container
->devs
; cd
; cd
= cd
->next
)
389 if (di
->disk
.major
== cd
->disk
.major
&&
390 di
->disk
.minor
== cd
->disk
.minor
)
393 struct mdinfo
*newd
= xmalloc(sizeof(*newd
));
396 add_disk_to_container(container
, newd
);
400 container
->devcnt
= mdstat
->devcnt
;
404 static int sysfs_open2(char *devnum
, char *name
, char *attr
)
406 int fd
= sysfs_open(devnum
, name
, attr
);
408 /* seq_file in the kernel allocates buffer space
409 * on the first read. Do that now so 'monitor'
413 if (read(fd
, buf
, sizeof(buf
)) < 0)
414 /* pretend not to ignore return value */
420 static int disk_init_and_add(struct mdinfo
*disk
, struct mdinfo
*clone
,
421 struct active_array
*aa
)
427 disk
->recovery_fd
= sysfs_open2(aa
->info
.sys_name
, disk
->sys_name
,
429 if (disk
->recovery_fd
< 0)
431 disk
->state_fd
= sysfs_open2(aa
->info
.sys_name
, disk
->sys_name
, "state");
432 if (disk
->state_fd
< 0) {
433 close(disk
->recovery_fd
);
436 disk
->prev_state
= read_dev_state(disk
->state_fd
);
437 disk
->curr_state
= disk
->prev_state
;
438 disk
->next
= aa
->info
.devs
;
439 aa
->info
.devs
= disk
;
444 static void manage_member(struct mdstat_ent
*mdstat
,
445 struct active_array
*a
)
447 /* Compare mdstat info with known state of member array.
448 * We do not need to look for device state changes here, that
449 * is dealt with by the monitor.
451 * If a reshape is being requested, monitor will have noticed
452 * that sync_action changed and will have set check_reshape.
453 * We just need to see if new devices have appeared. All metadata
454 * updates will already have been processed.
456 * We also want to handle degraded arrays here by
457 * trying to find and assign a spare.
458 * We do that whenever the monitor tells us too.
462 struct supertype
*container
= a
->container
;
463 unsigned long long int component_size
= 0;
465 if (container
== NULL
)
466 /* Raced with something */
469 if (mdstat
->active
) {
471 a
->info
.array
.raid_disks
= mdstat
->raid_disks
;
475 if (sysfs_get_ll(&a
->info
, NULL
, "component_size", &component_size
) >= 0)
476 a
->info
.component_size
= component_size
<< 1;
479 if (sysfs_get_str(&a
->info
, NULL
, "metadata_version", buf
, sizeof(buf
)) > 0)
480 frozen
= buf
[9] == '-';
482 frozen
= 1; /* can't read metadata_version assume the worst */
484 /* If sync_action is not 'idle' then don't try recovery now */
486 && sysfs_get_str(&a
->info
, NULL
, "sync_action", buf
, sizeof(buf
)) > 0
487 && strncmp(buf
, "idle", 4) != 0)
491 int level
= map_name(pers
, mdstat
->level
);
492 if (level
== 0 || level
== LEVEL_LINEAR
) {
497 else if (a
->info
.array
.level
!= level
&& level
> 0) {
498 struct active_array
*newa
= duplicate_aa(a
);
500 newa
->info
.array
.level
= level
;
501 replace_array(container
, a
, newa
);
507 /* we are after monitor kick,
508 * so container field can be cleared - check it again
510 if (a
->container
== NULL
)
513 if (sigterm
&& a
->info
.safe_mode_delay
!= 1) {
514 sysfs_set_safemode(&a
->info
, 1);
515 a
->info
.safe_mode_delay
= 1;
518 /* We don't check the array while any update is pending, as it
519 * might container a change (such as a spare assignment) which
520 * could affect our decisions.
522 if (a
->check_degraded
&& !frozen
&&
523 update_queue
== NULL
&& update_queue_pending
== NULL
) {
524 struct metadata_update
*updates
= NULL
;
525 struct mdinfo
*newdev
= NULL
;
526 struct active_array
*newa
;
529 a
->check_degraded
= 0;
531 /* The array may not be degraded, this is just a good time
534 newdev
= container
->ss
->activate_spare(a
, &updates
);
538 newa
= duplicate_aa(a
);
541 /* prevent the kernel from activating the disk(s) before we
544 dprintf("freezing %s\n", a
->info
.sys_name
);
545 sysfs_set_str(&a
->info
, NULL
, "sync_action", "frozen");
547 /* Add device to array and set offset/size/slot.
548 * and open files for each newdev */
549 for (d
= newdev
; d
; d
= d
->next
) {
552 newd
= xmalloc(sizeof(*newd
));
553 if (sysfs_add_disk(&newa
->info
, d
, 0) < 0) {
557 disk_init_and_add(newd
, d
, newa
);
559 queue_metadata_update(updates
);
561 while (update_queue_pending
|| update_queue
) {
562 check_update_queue(container
);
565 replace_array(container
, a
, newa
);
566 if (sysfs_set_str(&a
->info
, NULL
, "sync_action", "recover")
568 newa
->prev_action
= recover
;
569 dprintf("recovery started on %s\n", a
->info
.sys_name
);
576 free_updates(&updates
);
579 if (a
->check_reshape
) {
580 /* mdadm might have added some devices to the array.
581 * We want to disk_init_and_add any such device to a
582 * duplicate_aa and replace a with that.
583 * mdstat doesn't have enough info so we sysfs_read
584 * and look for new stuff.
586 struct mdinfo
*info
, *d
, *d2
, *newd
;
587 unsigned long long array_size
;
588 struct active_array
*newa
= NULL
;
589 a
->check_reshape
= 0;
590 info
= sysfs_read(-1, mdstat
->devnm
,
591 GET_DEVS
|GET_OFFSET
|GET_SIZE
|GET_STATE
);
594 for (d
= info
->devs
; d
; d
= d
->next
) {
595 if (d
->disk
.raid_disk
< 0)
597 for (d2
= a
->info
.devs
; d2
; d2
= d2
->next
)
598 if (d2
->disk
.raid_disk
==
602 /* already have this one */
605 newa
= duplicate_aa(a
);
609 newd
= xmalloc(sizeof(*newd
));
610 disk_init_and_add(newd
, d
, newa
);
612 if (sysfs_get_ll(info
, NULL
, "array_size", &array_size
) == 0
613 && a
->info
.custom_array_size
> array_size
*2) {
614 sysfs_set_num(info
, NULL
, "array_size",
615 a
->info
.custom_array_size
/2);
620 replace_array(container
, a
, newa
);
624 static int aa_ready(struct active_array
*aa
)
627 int level
= aa
->info
.array
.level
;
629 for (d
= aa
->info
.devs
; d
; d
= d
->next
)
633 if (aa
->info
.state_fd
< 0)
636 if (level
> 0 && (aa
->action_fd
< 0 || aa
->resync_start_fd
< 0))
645 static void manage_new(struct mdstat_ent
*mdstat
,
646 struct supertype
*container
,
647 struct active_array
*victim
)
649 /* A new array has appeared in this container.
650 * Hopefully it is already recorded in the metadata.
651 * Check, then create the new array to report it to
655 struct active_array
*new;
656 struct mdinfo
*mdi
, *di
;
662 /* check if array is ready to be monitored */
663 if (!mdstat
->active
|| !mdstat
->level
)
665 if (strcmp(mdstat
->level
, "raid0") == 0 ||
666 strcmp(mdstat
->level
, "linear") == 0)
669 mdi
= sysfs_read(-1, mdstat
->devnm
,
670 GET_LEVEL
|GET_CHUNK
|GET_DISKS
|GET_COMPONENT
|
671 GET_DEGRADED
|GET_SAFEMODE
|
672 GET_DEVS
|GET_OFFSET
|GET_SIZE
|GET_STATE
|GET_LAYOUT
);
676 new = xcalloc(1, sizeof(*new));
678 strcpy(new->info
.sys_name
, mdstat
->devnm
);
680 new->prev_state
= new->curr_state
= new->next_state
= inactive
;
681 new->prev_action
= new->curr_action
= new->next_action
= idle
;
683 new->container
= container
;
685 inst
= to_subarray(mdstat
, container
->devnm
);
687 new->info
.array
= mdi
->array
;
688 new->info
.component_size
= mdi
->component_size
;
690 for (i
= 0; i
< new->info
.array
.raid_disks
; i
++) {
691 struct mdinfo
*newd
= xmalloc(sizeof(*newd
));
693 for (di
= mdi
->devs
; di
; di
= di
->next
)
694 if (i
== di
->disk
.raid_disk
)
697 if (disk_init_and_add(newd
, di
, new) != 0) {
702 if (failed
> new->info
.array
.failed_disks
) {
703 /* we cannot properly monitor without all working disks */
704 new->container
= NULL
;
710 new->action_fd
= sysfs_open2(new->info
.sys_name
, NULL
, "sync_action");
711 new->info
.state_fd
= sysfs_open2(new->info
.sys_name
, NULL
, "array_state");
712 new->resync_start_fd
= sysfs_open2(new->info
.sys_name
, NULL
, "resync_start");
713 new->metadata_fd
= sysfs_open2(new->info
.sys_name
, NULL
, "metadata_version");
714 new->sync_completed_fd
= sysfs_open2(new->info
.sys_name
, NULL
, "sync_completed");
716 dprintf("inst: %s action: %d state: %d\n", inst
,
717 new->action_fd
, new->info
.state_fd
);
720 new->info
.safe_mode_delay
= 1;
721 else if (mdi
->safe_mode_delay
>= 50)
722 /* Normal start, mdadm set this. */
723 new->info
.safe_mode_delay
= mdi
->safe_mode_delay
;
725 /* Restart, just pick a number */
726 new->info
.safe_mode_delay
= 5000;
727 sysfs_set_safemode(&new->info
, new->info
.safe_mode_delay
);
729 /* reshape_position is set by mdadm in sysfs
730 * read this information for new arrays only (empty victim)
732 if ((victim
== NULL
) &&
733 (sysfs_get_str(mdi
, NULL
, "sync_action", buf
, 40) > 0) &&
734 (strncmp(buf
, "reshape", 7) == 0)) {
735 if (sysfs_get_ll(mdi
, NULL
, "reshape_position",
736 &new->last_checkpoint
) != 0)
737 new->last_checkpoint
= 0;
739 int data_disks
= mdi
->array
.raid_disks
;
740 if (mdi
->array
.level
== 4 || mdi
->array
.level
== 5)
742 if (mdi
->array
.level
== 6)
745 new->last_checkpoint
/= data_disks
;
747 dprintf("mdmon: New monitored array is under reshape.\n"
748 " Last checkpoint is: %llu\n",
749 new->last_checkpoint
);
754 /* if everything checks out tell the metadata handler we want to
755 * manage this instance
757 if (!aa_ready(new) || container
->ss
->open_new(container
, new, inst
) < 0) {
758 pr_err("failed to monitor %s\n",
759 mdstat
->metadata_version
);
760 new->container
= NULL
;
763 replace_array(container
, victim
, new);
765 new->check_degraded
= 1;
766 manage_member(mdstat
, new);
771 void manage(struct mdstat_ent
*mdstat
, struct supertype
*container
)
773 /* We have just read mdstat and need to compare it with
774 * the known active arrays.
775 * Arrays with the wrong metadata are ignored.
778 for ( ; mdstat
; mdstat
= mdstat
->next
) {
779 struct active_array
*a
;
780 if (strcmp(mdstat
->devnm
, container
->devnm
) == 0) {
781 manage_container(mdstat
, container
);
784 if (!is_container_member(mdstat
, container
->devnm
))
785 /* Not for this array */
787 /* Looks like a member of this container */
788 for (a
= container
->arrays
; a
; a
= a
->next
) {
789 if (strcmp(mdstat
->devnm
, a
->info
.sys_name
) == 0) {
790 if (a
->container
&& a
->to_remove
== 0)
791 manage_member(mdstat
, a
);
795 if (a
== NULL
|| !a
->container
)
796 manage_new(mdstat
, container
, a
);
800 static void handle_message(struct supertype
*container
, struct metadata_update
*msg
)
802 /* queue this metadata update through to the monitor */
804 struct metadata_update
*mu
;
807 while (update_queue_pending
|| update_queue
) {
808 check_update_queue(container
);
812 if (msg
->len
== 0) { /* ping_monitor */
815 cnt
= monitor_loop_cnt
;
817 cnt
+= 2; /* wait until next pselect */
819 cnt
+= 3; /* wait for 2 pselects */
822 while (monitor_loop_cnt
- cnt
< 0)
824 } else if (msg
->len
== -1) { /* ping_manager */
825 struct mdstat_ent
*mdstat
= mdstat_read(1, 0);
827 manage(mdstat
, container
);
829 } else if (!sigterm
) {
830 mu
= xmalloc(sizeof(*mu
));
835 mu
->space_list
= NULL
;
837 if (container
->ss
->prepare_update
)
838 if (!container
->ss
->prepare_update(container
, mu
))
840 queue_metadata_update(mu
);
844 void read_sock(struct supertype
*container
)
847 struct metadata_update msg
;
850 int tmo
= 3; /* 3 second timeout before hanging up the socket */
852 fd
= accept(container
->sock
, NULL
, NULL
);
856 fl
= fcntl(fd
, F_GETFL
, 0);
858 fcntl(fd
, F_SETFL
, fl
);
863 /* read and validate the message */
864 if (receive_message(fd
, &msg
, tmo
) == 0) {
865 handle_message(container
, &msg
);
867 /* ping reply with version */
869 msg
.len
= strlen(Version
) + 1;
870 if (send_message(fd
, &msg
, tmo
) < 0)
872 } else if (ack(fd
, tmo
) < 0)
877 } while (!terminate
);
883 int manager_ready
= 0;
884 void do_manager(struct supertype
*container
)
886 struct mdstat_ent
*mdstat
;
889 sigprocmask(SIG_UNBLOCK
, NULL
, &set
);
890 sigdelset(&set
, SIGUSR1
);
891 sigdelset(&set
, SIGTERM
);
898 /* Can only 'manage' things if 'monitor' is not making
899 * structural changes to metadata, so need to check
902 if (update_queue
== NULL
) {
903 mdstat
= mdstat_read(1, 0);
905 manage(mdstat
, container
);
907 read_sock(container
);
913 check_update_queue(container
);
920 if (update_queue
== NULL
)
921 mdstat_wait_fd(container
->sock
, &set
);
923 /* If an update is happening, just wait for signal */
924 pselect(0, NULL
, NULL
, NULL
, NULL
, &set
);