2 * mapfile - keep track of uuid <-> array mapping. Part of:
3 * mdadm - manage Linux "md" devices aka RAID arrays.
5 * Copyright (C) 2006-2010 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 /* The mapfile 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 best place for the mapfile wold be /var/run/mdadm/map. However
42 * it is needed during initramfs early-boot, and /var/run doesn't exist there
43 * and certainly doesn't persist through to normal boot.
44 * So we store it in /dev/.mdadm/map but allow this to be changed at
45 * compile time. via MAP_DIR and MAP_FILE
53 #define MAP_DIR "/dev/.mdadm"
54 #define MAP_FILE "map"
61 #define mapnames(dir, base) { \
65 MAP_DIR "/" MAP_FILE ".new",
66 MAP_DIR "/" MAP_FILE ".lock",
70 int mapmode[3] = { O_RDONLY, O_RDWR|O_CREAT, O_RDWR|O_CREAT|O_TRUNC };
71 char *mapsmode[3] = { "r", "w", "w"};
73 FILE *open_map(int modenum)
76 if ((mapmode[modenum] & O_CREAT))
77 /* Attempt to create directory, don't worry about
80 (void)mkdir(mapname[MAP_DIRNAME], 0755);
81 fd = open(mapname[modenum], mapmode[modenum], 0600);
83 return fdopen(fd, mapsmode[modenum]);
87 int map_write(struct map_ent *mel)
92 f = open_map(MAP_NEW);
96 for (; mel; mel = mel->next) {
100 fprintf(f, "mdp%d ", -1-mel->devnum);
102 fprintf(f, "md%d ", mel->devnum);
103 fprintf(f, "%s ", mel->metadata);
104 fprintf(f, "%08x:%08x:%08x:%08x ", mel->uuid[0],
105 mel->uuid[1], mel->uuid[2], mel->uuid[3]);
106 fprintf(f, "%s\n", mel->path?:"");
115 return rename(mapname[1],
120 static FILE *lf = NULL;
121 int map_lock(struct map_ent **melp)
125 lf = open_map(MAP_LOCK);
128 if (flock(fileno(lf), LOCK_EX) != 0) {
133 if (fstat(fileno(lf), &buf) != 0 ||
135 /* The owner of the lock unlinked it,
136 * so we have a lock on a stale file,
149 void map_unlock(struct map_ent **melp)
152 /* must unlink before closing the file,
153 * as only the owner of the lock may
164 /* We are forking, so must close the lock file.
165 * Don't risk flushing anything though.
174 void map_add(struct map_ent **melp,
175 int devnum, char *metadata, int uuid[4], char *path)
177 struct map_ent *me = malloc(sizeof(*me));
180 strcpy(me->metadata, metadata);
181 memcpy(me->uuid, uuid, 16);
182 me->path = path ? strdup(path) : NULL;
188 void map_read(struct map_ent **melp)
199 f = open_map(MAP_READ);
202 f = open_map(MAP_READ);
207 while (fgets(buf, sizeof(buf), f)) {
209 if (sscanf(buf, " %3[mdp]%d %s %x:%x:%x:%x %200s",
210 nam, &devnum, metadata, uuid, uuid+1,
211 uuid+2, uuid+3, path) >= 7) {
212 if (strncmp(nam, "md", 2) != 0)
215 devnum = -1 - devnum;
216 map_add(melp, devnum, metadata, uuid, path);
222 void map_free(struct map_ent *map)
225 struct map_ent *mp = map;
232 int map_update(struct map_ent **mpp, int devnum, char *metadata,
233 int *uuid, char *path)
235 struct map_ent *map, *mp;
243 for (mp = map ; mp ; mp=mp->next)
244 if (mp->devnum == devnum) {
245 strcpy(mp->metadata, metadata);
246 memcpy(mp->uuid, uuid, 16);
248 mp->path = path ? strdup(path) : NULL;
253 map_add(&map, devnum, metadata, uuid, path);
261 void map_delete(struct map_ent **mapp, int devnum)
268 for (mp = *mapp; mp; mp = *mapp) {
269 if (mp->devnum == devnum) {
278 void map_remove(struct map_ent **mapp, int devnum)
280 if (devnum == NoMdDev)
283 map_delete(mapp, devnum);
288 struct map_ent *map_by_uuid(struct map_ent **map, int uuid[4])
294 for (mp = *map ; mp ; mp = mp->next) {
295 if (memcmp(uuid, mp->uuid, 16) != 0)
297 if (!mddev_busy(mp->devnum)) {
306 struct map_ent *map_by_devnum(struct map_ent **map, int devnum)
312 for (mp = *map ; mp ; mp = mp->next) {
313 if (mp->devnum != devnum)
315 if (!mddev_busy(mp->devnum)) {
324 struct map_ent *map_by_name(struct map_ent **map, char *name)
330 for (mp = *map ; mp ; mp = mp->next) {
333 if (strncmp(mp->path, "/dev/md/", 8) != 0)
335 if (strcmp(mp->path+8, name) != 0)
337 if (!mddev_busy(mp->devnum)) {
346 /* sets the proper subarray and container_dev according to the metadata
347 * version super_by_fd does this automatically, this routine is meant as
348 * a supplement for guess_super()
350 static char *get_member_info(struct mdstat_ent *ent)
353 if (ent->metadata_version == NULL ||
354 strncmp(ent->metadata_version, "external:", 9) != 0)
357 if (is_subarray(&ent->metadata_version[9])) {
360 subarray = strrchr(ent->metadata_version, '/');
366 void RebuildMap(void)
368 struct mdstat_ent *mdstat = mdstat_read(0, 0);
369 struct mdstat_ent *md;
370 struct map_ent *map = NULL;
371 int mdp = get_mdp_major();
372 int require_homehost;
373 char sys_hostname[256];
374 char *homehost = conf_get_homehost(&require_homehost);
376 if (homehost == NULL || strcmp(homehost, "<system>")==0) {
377 if (gethostname(sys_hostname, sizeof(sys_hostname)) == 0) {
378 sys_hostname[sizeof(sys_hostname)-1] = 0;
379 homehost = sys_hostname;
383 for (md = mdstat ; md ; md = md->next) {
384 struct mdinfo *sra = sysfs_read(-1, md->devnum, GET_DEVS);
390 for (sd = sra->devs ; sd ; sd = sd->next) {
395 struct supertype *st;
396 char *subarray = NULL;
400 sprintf(dn, "%d:%d", sd->disk.major, sd->disk.minor);
401 dfd = dev_open(dn, O_RDONLY);
404 st = guess_super(dfd);
408 subarray = get_member_info(md);
409 ok = st->ss->load_super(st, dfd, NULL);
414 info = st->ss->container_content(st, subarray);
417 path = map_dev(MD_MAJOR, md->devnum, 0);
419 path = map_dev(mdp, (-1-md->devnum)<< 6, 0);
421 strncmp(path, "/dev/md/", 8) != 0) {
422 /* We would really like a name that provides
423 * an MD_DEVNAME for udev.
424 * The name needs to be unique both in /dev/md/
425 * and in this mapfile.
426 * It needs to match watch -I or -As would come
429 * Check if array is in mdadm.conf
431 * determine trustworthy from homehost etc
432 * find a unique name based on metadata name.
435 struct mddev_ident *match = conf_match(st, info,
439 if (match && match->devname && match->devname[0] == '/') {
440 path = match->devname;
441 if (path[0] != '/') {
442 strcpy(namebuf, "/dev/md/");
443 strcat(namebuf, path);
451 if ((homehost == NULL ||
452 st->ss->match_home(st, homehost) != 1) &&
453 st->ss->match_home(st, "any") != 1 &&
455 || ! conf_name_is_free(info->name)))
456 /* require a numeric suffix */
459 /* allow name to be used as-is if no conflict */
464 if (!isdigit(name[strlen(name)-1]) &&
470 if (strchr(name, ':'))
471 /* probably a uniquifying
472 * hostname prefix. Allow
479 sprintf(namebuf, "/dev/md/%s%s%d",
482 sprintf(namebuf, "/dev/md/%s",
485 if (lstat(namebuf, &stb) != 0 &&
487 !map_by_name(&map, namebuf+8)))
493 map_add(&map, md->devnum,
496 st->ss->free_super(st);
502 /* Only trigger a change if we wrote a new map file */
504 for (md = mdstat ; md ; md = md->next) {
505 struct mdinfo *sra = sysfs_read(-1, md->devnum,
508 sysfs_uevent(sra, "change");