]>
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 enum array_state
read_state(int fd
)
86 int n
= read_attr(buf
, 20, fd
);
90 return (enum array_state
) sysfs_match_word(buf
, array_states
);
93 static enum sync_action
read_action( int fd
)
96 int n
= read_attr(buf
, 20, fd
);
100 return (enum sync_action
) sysfs_match_word(buf
, sync_actions
);
103 int read_dev_state(int fd
)
106 int n
= read_attr(buf
, 60, fd
);
115 if (sysfs_attr_match(cp
, "faulty"))
117 if (sysfs_attr_match(cp
, "in_sync"))
119 if (sysfs_attr_match(cp
, "write_mostly"))
120 rv
|= DS_WRITE_MOSTLY
;
121 if (sysfs_attr_match(cp
, "spare"))
123 if (sysfs_attr_match(cp
, "blocked"))
125 cp
= strchr(cp
, ',');
132 static void signal_manager(void)
134 /* tgkill(getpid(), mon_tid, SIGUSR1); */
136 syscall(SYS_tgkill
, pid
, mgr_tid
, SIGUSR1
);
139 /* Monitor a set of active md arrays - all of which share the
140 * same metadata - and respond to events that require
143 * New arrays are detected by another thread which allocates
144 * required memory and attaches the data structure to our list.
148 * This is detected by array_state going to 'clear' or 'inactive'.
149 * while we thought it was active.
150 * Response is to mark metadata as clean and 'clear' the array(??)
152 * array_state if 'write-pending'
153 * We mark metadata as 'dirty' then set array to 'active'.
155 * Either ignore, or mark clean, then mark metadata as clean.
158 * detected by rd-N/state reporting "faulty"
159 * mark device as 'failed' in metadata, let the kernel release the
160 * device by writing '-blocked' to rd/state, and finally write 'remove' to
161 * rd/state. Before a disk can be replaced it must be failed and removed
162 * from all container members, this will be preemptive for the other
166 * sync_action was 'resync' and becomes 'idle' and resync_start becomes
168 * Notify metadata that sync is complete.
171 * sync_action changes from 'recover' to 'idle'
172 * Check each device state and mark metadata if 'faulty' or 'in_sync'.
175 * This only happens on finding a new array... mdadm will have set
176 * 'resync_start' to the correct value. If 'resync_start' indicates that an
177 * resync needs to occur set the array to the 'active' state rather than the
178 * initial read-auto state.
182 * We wait for a change (poll/select) on array_state, sync_action, and
183 * each rd-X/state file.
184 * When we get any change, we check everything. So read each state file,
185 * then decide what to do.
187 * The core action is to write new metadata to all devices in the array.
188 * This is done at most once on any wakeup.
189 * After that we might:
190 * - update the array_state
191 * - set the role of some devices.
192 * - request a sync_action
196 static int read_and_act(struct active_array
*a
)
198 int check_degraded
= 0;
203 a
->next_state
= bad_word
;
204 a
->next_action
= bad_action
;
206 a
->curr_state
= read_state(a
->info
.state_fd
);
207 a
->curr_action
= read_action(a
->action_fd
);
208 a
->info
.resync_start
= read_resync_start(a
->resync_start_fd
);
209 for (mdi
= a
->info
.devs
; mdi
; mdi
= mdi
->next
) {
211 if (mdi
->state_fd
>= 0) {
212 mdi
->recovery_start
= read_resync_start(mdi
->recovery_fd
);
213 mdi
->curr_state
= read_dev_state(mdi
->state_fd
);
217 if (a
->curr_state
<= inactive
&&
218 a
->prev_state
> inactive
) {
219 /* array has been stopped */
220 a
->container
->ss
->set_array_state(a
, 1);
221 a
->next_state
= clear
;
224 if (a
->curr_state
== write_pending
) {
225 a
->container
->ss
->set_array_state(a
, 0);
226 a
->next_state
= active
;
229 if (a
->curr_state
== active_idle
) {
230 /* Set array to 'clean' FIRST, then mark clean
233 a
->next_state
= clean
;
236 if (a
->curr_state
== clean
) {
237 a
->container
->ss
->set_array_state(a
, 1);
239 if (a
->curr_state
== active
||
240 a
->curr_state
== suspended
||
241 a
->curr_state
== bad_word
)
243 if (a
->curr_state
== readonly
) {
244 /* Well, I'm ready to handle things. If readonly
245 * wasn't requested, transition to read-auto.
248 read_attr(buf
, sizeof(buf
), a
->metadata_fd
);
249 if (strncmp(buf
, "external:-", 10) == 0) {
250 /* explicit request for readonly array. Leave it alone */
253 if (a
->container
->ss
->set_array_state(a
, 2))
254 a
->next_state
= read_auto
; /* array is clean */
256 a
->next_state
= active
; /* Now active for recovery etc */
263 a
->curr_action
== idle
&&
264 a
->prev_action
== resync
) {
265 /* A resync has finished. The endpoint is recorded in
266 * 'sync_start'. We don't update the metadata
267 * until the array goes inactive or readonly though.
268 * Just check if we need to fiddle spares.
270 a
->container
->ss
->set_array_state(a
, a
->curr_state
<= clean
);
275 a
->curr_action
== idle
&&
276 a
->prev_action
== recover
) {
277 /* A recovery has finished. Some disks may be in sync now,
278 * and the array may no longer be degraded
280 for (mdi
= a
->info
.devs
; mdi
; mdi
= mdi
->next
) {
281 a
->container
->ss
->set_disk(a
, mdi
->disk
.raid_disk
,
283 if (! (mdi
->curr_state
& DS_INSYNC
))
288 /* Check for failures and if found:
289 * 1/ Record the failure in the metadata and unblock the device.
290 * FIXME update the kernel to stop notifying on failed drives when
291 * the array is readonly and we have cleared 'blocked'
292 * 2/ Try to remove the device if the array is writable, or can be
295 for (mdi
= a
->info
.devs
; mdi
; mdi
= mdi
->next
) {
296 if (mdi
->curr_state
& DS_FAULTY
) {
297 a
->container
->ss
->set_disk(a
, mdi
->disk
.raid_disk
,
300 mdi
->next_state
|= DS_UNBLOCK
;
301 if (a
->curr_state
== read_auto
) {
302 a
->container
->ss
->set_array_state(a
, 0);
303 a
->next_state
= active
;
305 if (a
->curr_state
> readonly
)
306 mdi
->next_state
|= DS_REMOVE
;
310 a
->container
->ss
->sync_metadata(a
->container
);
311 dprintf("%s(%d): state:%s action:%s next(", __func__
, a
->info
.container_member
,
312 array_states
[a
->curr_state
], sync_actions
[a
->curr_action
]);
314 /* Effect state changes in the array */
315 if (a
->next_state
!= bad_word
) {
316 dprintf(" state:%s", array_states
[a
->next_state
]);
317 write_attr(array_states
[a
->next_state
], a
->info
.state_fd
);
319 if (a
->next_action
!= bad_action
) {
320 write_attr(sync_actions
[a
->next_action
], a
->action_fd
);
321 dprintf(" action:%s", sync_actions
[a
->next_action
]);
323 for (mdi
= a
->info
.devs
; mdi
; mdi
= mdi
->next
) {
324 if (mdi
->next_state
& DS_UNBLOCK
) {
325 dprintf(" %d:-blocked", mdi
->disk
.raid_disk
);
326 write_attr("-blocked", mdi
->state_fd
);
329 if ((mdi
->next_state
& DS_REMOVE
) && mdi
->state_fd
>= 0) {
332 /* the kernel may not be able to immediately remove the
333 * disk, we can simply wait until the next event to try
336 remove_result
= write_attr("remove", mdi
->state_fd
);
337 if (remove_result
> 0) {
338 dprintf(" %d:removed", mdi
->disk
.raid_disk
);
339 close(mdi
->state_fd
);
343 if (mdi
->next_state
& DS_INSYNC
) {
344 write_attr("+in_sync", mdi
->state_fd
);
345 dprintf(" %d:+in_sync", mdi
->disk
.raid_disk
);
350 /* move curr_ to prev_ */
351 a
->prev_state
= a
->curr_state
;
353 a
->prev_action
= a
->curr_action
;
355 for (mdi
= a
->info
.devs
; mdi
; mdi
= mdi
->next
) {
356 mdi
->prev_state
= mdi
->curr_state
;
360 if (check_degraded
) {
361 /* manager will do the actual check */
362 a
->check_degraded
= 1;
372 static struct mdinfo
*
373 find_device(struct active_array
*a
, int major
, int minor
)
377 for (mdi
= a
->info
.devs
; mdi
; mdi
= mdi
->next
)
378 if (mdi
->disk
.major
== major
&& mdi
->disk
.minor
== minor
)
384 static void reconcile_failed(struct active_array
*aa
, struct mdinfo
*failed
)
386 struct active_array
*a
;
387 struct mdinfo
*victim
;
389 for (a
= aa
; a
; a
= a
->next
) {
392 victim
= find_device(a
, failed
->disk
.major
, failed
->disk
.minor
);
396 if (!(victim
->curr_state
& DS_FAULTY
))
397 write_attr("faulty", victim
->state_fd
);
402 static void dprint_wake_reasons(fd_set
*fds
)
410 fprintf(stderr
, "monitor: wake ( ");
411 for (i
= 0; i
< FD_SETSIZE
; i
++) {
412 if (FD_ISSET(i
, fds
)) {
413 sprintf(proc_path
, "/proc/%d/fd/%d",
416 rv
= readlink(proc_path
, link
, sizeof(link
) - 1);
418 fprintf(stderr
, "%d:unknown ", i
);
422 basename
= strrchr(link
, '/');
423 fprintf(stderr
, "%d:%s ",
424 i
, basename
? ++basename
: link
);
427 fprintf(stderr
, ")\n");
431 int monitor_loop_cnt
;
433 static int wait_and_act(struct supertype
*container
, int nowait
)
437 struct active_array
**aap
= &container
->arrays
;
438 struct active_array
*a
, **ap
;
441 static unsigned int dirty_arrays
= ~0; /* start at some non-zero value */
445 for (ap
= aap
; *ap
;) {
447 /* once an array has been deactivated we want to
448 * ask the manager to discard it.
462 add_fd(&rfds
, &maxfd
, a
->info
.state_fd
);
463 add_fd(&rfds
, &maxfd
, a
->action_fd
);
464 for (mdi
= a
->info
.devs
; mdi
; mdi
= mdi
->next
)
465 add_fd(&rfds
, &maxfd
, mdi
->state_fd
);
470 if (manager_ready
&& (*aap
== NULL
|| (sigterm
&& !dirty_arrays
))) {
471 /* No interesting arrays, or we have been told to
472 * terminate and everything is clean. Lets see about
473 * exiting. Note that blocking at this point is not a
474 * problem as there are no active arrays, there is
475 * nothing that we need to be ready to do.
477 int fd
= open_dev_excl(container
->devnum
);
478 if (fd
>= 0 || errno
!= EBUSY
) {
479 /* OK, we are safe to leave */
480 if (sigterm
&& !dirty_arrays
)
481 dprintf("caught sigterm, all clean... exiting\n");
483 dprintf("no arrays to monitor... exiting\n");
485 /* On SIGTERM, someone (the take-over mdmon) will
488 remove_pidfile(container
->devname
);
497 sigprocmask(SIG_UNBLOCK
, NULL
, &set
);
498 sigdelset(&set
, SIGUSR1
);
499 monitor_loop_cnt
|= 1;
500 rv
= pselect(maxfd
+1, NULL
, NULL
, &rfds
, NULL
, &set
);
501 monitor_loop_cnt
+= 1;
502 if (rv
== -1 && errno
== EINTR
)
505 dprint_wake_reasons(&rfds
);
511 struct metadata_update
*this;
513 for (this = update_queue
; this ; this = this->next
)
514 container
->ss
->process_update(container
, this);
516 update_queue_handled
= update_queue
;
519 container
->ss
->sync_metadata(container
);
524 for (a
= *aap
; a
; a
= a
->next
) {
527 if (a
->replaces
&& !discard_this
) {
528 struct active_array
**ap
;
529 for (ap
= &a
->next
; *ap
&& *ap
!= a
->replaces
;
534 discard_this
= a
->replaces
;
536 /* FIXME check if device->state_fd need to be cleared?*/
540 is_dirty
= read_and_act(a
);
542 dirty_arrays
+= is_dirty
;
543 /* when terminating stop manipulating the array after it
544 * is clean, but make sure read_and_act() is given a
545 * chance to handle 'active_idle'
547 if (sigterm
&& !is_dirty
)
548 a
->container
= NULL
; /* stop touching this array */
552 /* propagate failures across container members */
553 for (a
= *aap
; a
; a
= a
->next
) {
556 for (mdi
= a
->info
.devs
; mdi
; mdi
= mdi
->next
)
557 if (mdi
->curr_state
& DS_FAULTY
)
558 reconcile_failed(*aap
, mdi
);
564 void do_monitor(struct supertype
*container
)
569 rv
= wait_and_act(container
, first
);