2 * mapfile - manage /var/run/mdadm.map. Part of:
3 * mdadm - manage Linux "md" devices aka RAID arrays.
5 * Copyright (C) 2006-2009 Neil Brown <neilb@suse.de>
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 * Email: <neilb@suse.de>
27 * QVB Post Office, NSW 1230
31 /* /var/run/mdadm.map is used to track arrays being created in --incremental
32 * mode. It particularly allows lookup from UUID to array device, but
33 * also allows the array device name to be easily found.
35 * The map file is line based with space separated fields. The fields are:
36 * Device id - mdX or mdpX where X is a number.
37 * metadata - 0.90 1.0 1.1 1.2 ddf ...
38 * UUID - uuid of the array
39 * path - path where device created: /dev/md/home
41 * The preferred location for the map file is /var/run/mdadm.map.
42 * However /var/run may not exist or be writable in early boot. And if
43 * no-one has created /var/run/mdadm, we still want to survive.
44 * So possible locations are:
45 * /var/run/mdadm/map /var/run/mdadm.map /lib/initrw/madam/map
46 * The last can easily be change at compile to e.g. somewhere in /dev.
47 * We read from the first one that exists and write to the first
54 #define mapnames(base) { base, base ".new", base ".lock"}
55 char *mapname[2][3] = {
56 mapnames(MAP_DIR "/" MAP_FILE),
57 mapnames("/var/run/mdadm.map")
59 char *mapdir[2] = { MAP_DIR, NULL };
61 int mapmode[3] = { O_RDONLY, O_RDWR|O_CREAT, O_RDWR|O_CREAT|O_TRUNC };
62 char *mapsmode[3] = { "r", "w", "w"};
64 FILE *open_map(int modenum, int *choice)
68 for (i = 0 ; i < 2 ; i++) {
70 if ((mapmode[modenum] & O_CREAT) && mapdir[i])
71 /* Attempt to create directory, don't worry about
74 mkdir(mapdir[i], 0755);
75 fd = open(mapname[i][modenum], mapmode[modenum], 0600);
78 return fdopen(fd, mapsmode[modenum]);
84 int map_write(struct map_ent *mel)
90 f = open_map(1, &which);
94 for (; mel; mel = mel->next) {
98 fprintf(f, "mdp%d ", -1-mel->devnum);
100 fprintf(f, "md%d ", mel->devnum);
101 fprintf(f, "%s ", mel->metadata);
102 fprintf(f, "%08x:%08x:%08x:%08x ", mel->uuid[0],
103 mel->uuid[1], mel->uuid[2], mel->uuid[3]);
104 fprintf(f, "%s\n", mel->path?:"");
110 unlink(mapname[which][1]);
113 return rename(mapname[which][1],
114 mapname[which][0]) == 0;
118 static FILE *lf = NULL;
119 static int lwhich = 0;
120 int map_lock(struct map_ent **melp)
124 lf = open_map(2, &lwhich);
127 if (flock(fileno(lf), LOCK_EX) != 0) {
132 if (fstat(fileno(lf), &buf) != 0 ||
134 /* The owner of the lock unlinked it,
135 * so we have a lock on a stale file,
148 void map_unlock(struct map_ent **melp)
151 /* must unlink before closing the file,
152 * as only the owner of the lock may
155 unlink(mapname[lwhich][2]);
161 void map_add(struct map_ent **melp,
162 int devnum, char *metadata, int uuid[4], char *path)
164 struct map_ent *me = malloc(sizeof(*me));
167 strcpy(me->metadata, metadata);
168 memcpy(me->uuid, uuid, 16);
169 me->path = path ? strdup(path) : NULL;
175 void map_read(struct map_ent **melp)
187 f = open_map(0, &which);
190 f = open_map(0, &which);
195 while (fgets(buf, sizeof(buf), f)) {
197 if (sscanf(buf, " %3[mdp]%d %s %x:%x:%x:%x %200s",
198 nam, &devnum, metadata, uuid, uuid+1,
199 uuid+2, uuid+3, path) >= 7) {
200 if (strncmp(nam, "md", 2) != 0)
203 devnum = -1 - devnum;
204 map_add(melp, devnum, metadata, uuid, path);
210 void map_free(struct map_ent *map)
213 struct map_ent *mp = map;
220 int map_update(struct map_ent **mpp, int devnum, char *metadata,
221 int *uuid, char *path)
223 struct map_ent *map, *mp;
231 for (mp = map ; mp ; mp=mp->next)
232 if (mp->devnum == devnum) {
233 strcpy(mp->metadata, metadata);
234 memcpy(mp->uuid, uuid, 16);
236 mp->path = path ? strdup(path) : NULL;
240 map_add(&map, devnum, metadata, uuid, path);
248 void map_delete(struct map_ent **mapp, int devnum)
255 for (mp = *mapp; mp; mp = *mapp) {
256 if (mp->devnum == devnum) {
265 void map_remove(struct map_ent **mapp, int devnum)
267 if (devnum == NoMdDev)
270 map_delete(mapp, devnum);
275 struct map_ent *map_by_uuid(struct map_ent **map, int uuid[4])
281 for (mp = *map ; mp ; mp = mp->next) {
282 if (memcmp(uuid, mp->uuid, 16) != 0)
284 if (!mddev_busy(mp->devnum)) {
293 struct map_ent *map_by_devnum(struct map_ent **map, int devnum)
299 for (mp = *map ; mp ; mp = mp->next) {
300 if (mp->devnum != devnum)
302 if (!mddev_busy(mp->devnum)) {
311 struct map_ent *map_by_name(struct map_ent **map, char *name)
317 for (mp = *map ; mp ; mp = mp->next) {
320 if (strncmp(mp->path, "/dev/md/", 8) != 0)
322 if (strcmp(mp->path+8, name) != 0)
324 if (!mddev_busy(mp->devnum)) {
333 /* sets the proper subarray and container_dev according to the metadata
334 * version super_by_fd does this automatically, this routine is meant as
335 * a supplement for guess_super()
337 static void set_member_info(struct supertype *st, struct mdstat_ent *ent)
340 st->subarray[0] = '\0';
342 if (ent->metadata_version == NULL ||
343 strncmp(ent->metadata_version, "external:", 9) != 0)
346 if (is_subarray(&ent->metadata_version[9])) {
347 char version[strlen(ent->metadata_version)+1];
349 char *name = &version[10];
351 strcpy(version, ent->metadata_version);
352 subarray = strrchr(version, '/');
359 st->container_dev = devname2devnum(name);
360 strncpy(st->subarray, subarray, sizeof(st->subarray));
364 void RebuildMap(void)
366 struct mdstat_ent *mdstat = mdstat_read(0, 0);
367 struct mdstat_ent *md;
368 struct map_ent *map = NULL;
369 int mdp = get_mdp_major();
370 int require_homehost;
371 char sys_hostname[256];
372 char *homehost = conf_get_homehost(&require_homehost);
374 if (homehost == NULL || strcmp(homehost, "<system>")==0) {
375 if (gethostname(sys_hostname, sizeof(sys_hostname)) == 0) {
376 sys_hostname[sizeof(sys_hostname)-1] = 0;
377 homehost = sys_hostname;
381 for (md = mdstat ; md ; md = md->next) {
382 struct mdinfo *sra = sysfs_read(-1, md->devnum, GET_DEVS);
388 for (sd = sra->devs ; sd ; sd = sd->next) {
393 struct supertype *st;
397 sprintf(dn, "%d:%d", sd->disk.major, sd->disk.minor);
398 dfd = dev_open(dn, O_RDONLY);
401 st = guess_super(dfd);
405 set_member_info(st, md);
406 ok = st->ss->load_super(st, dfd, NULL);
411 st->ss->getinfo_super(st, &info);
413 path = map_dev(MD_MAJOR, md->devnum, 0);
415 path = map_dev(mdp, (-1-md->devnum)<< 6, 0);
417 strncmp(path, "/dev/md/", 8) != 0) {
418 /* We would really like a name that provides
419 * an MD_DEVNAME for udev.
420 * The name needs to be unique both in /dev/md/
421 * and in this mapfile.
422 * It needs to match watch -I or -As would come
425 * Check if array is in mdadm.conf
427 * determine trustworthy from homehost etc
428 * find a unique name based on metadata name.
431 struct mddev_ident_s *match = conf_match(&info, st);
433 if (match && match->devname && match->devname[0] == '/') {
434 path = match->devname;
435 if (path[0] != '/') {
436 strcpy(namebuf, "/dev/md/");
437 strcat(namebuf, path);
445 if ((homehost == NULL ||
446 st->ss->match_home(st, homehost) != 1) &&
447 st->ss->match_home(st, "any") != 1 &&
449 || ! conf_name_is_free(info.name)))
450 /* require a numeric suffix */
453 /* allow name to be used as-is if no conflict */
458 if (!isdigit(name[strlen(name)-1]) &&
464 if (strchr(name, ':'))
465 /* probably a uniquifying
466 * hostname prefix. Allow
473 sprintf(namebuf, "/dev/md/%s%s%d",
476 sprintf(namebuf, "/dev/md/%s",
479 if (lstat(namebuf, &stb) != 0 &&
481 !map_by_name(&map, namebuf+8)))
487 map_add(&map, md->devnum,
490 st->ss->free_super(st);
495 /* Only trigger a change if we wrote a new map file */
497 for (md = mdstat ; md ; md = md->next) {
498 struct mdinfo *sra = sysfs_read(-1, md->devnum,
501 sysfs_uevent(sra, "change");