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1 | /* | |
2 | * mapfile - keep track of uuid <-> array mapping. Part of: | |
3 | * mdadm - manage Linux "md" devices aka RAID arrays. | |
4 | * | |
5 | * Copyright (C) 2006-2010 Neil Brown <neilb@suse.de> | |
6 | * | |
7 | * | |
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. | |
12 | * | |
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. | |
17 | * | |
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 | |
21 | * | |
22 | * Author: Neil Brown | |
23 | * Email: <neilb@suse.de> | |
24 | * Paper: Neil Brown | |
25 | * Novell Inc | |
26 | * GPO Box Q1283 | |
27 | * QVB Post Office, NSW 1230 | |
28 | * Australia | |
29 | */ | |
30 | ||
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. | |
34 | * | |
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 | |
40 | * | |
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 | |
46 | * | |
47 | */ | |
48 | #include "mdadm.h" | |
49 | #include <sys/file.h> | |
50 | #include <ctype.h> | |
51 | ||
52 | #ifndef MAP_DIR | |
53 | #define MAP_DIR "/dev/.mdadm" | |
54 | #define MAP_FILE "map" | |
55 | #endif | |
56 | ||
57 | #define MAP_READ 0 | |
58 | #define MAP_NEW 1 | |
59 | #define MAP_LOCK 2 | |
60 | #define MAP_DIRNAME 3 | |
61 | #define mapnames(dir, base) { \ | |
62 | ||
63 | char *mapname[4] = { | |
64 | MAP_DIR "/" MAP_FILE, | |
65 | MAP_DIR "/" MAP_FILE ".new", | |
66 | MAP_DIR "/" MAP_FILE ".lock", | |
67 | MAP_DIR | |
68 | }; | |
69 | ||
70 | int mapmode[3] = { O_RDONLY, O_RDWR|O_CREAT, O_RDWR|O_CREAT|O_TRUNC }; | |
71 | char *mapsmode[3] = { "r", "w", "w"}; | |
72 | ||
73 | FILE *open_map(int modenum) | |
74 | { | |
75 | int fd; | |
76 | if ((mapmode[modenum] & O_CREAT)) | |
77 | /* Attempt to create directory, don't worry about | |
78 | * failure. | |
79 | */ | |
80 | (void)mkdir(mapname[MAP_DIRNAME], 0755); | |
81 | fd = open(mapname[modenum], mapmode[modenum], 0600); | |
82 | if (fd >= 0) | |
83 | return fdopen(fd, mapsmode[modenum]); | |
84 | return NULL; | |
85 | } | |
86 | ||
87 | int map_write(struct map_ent *mel) | |
88 | { | |
89 | FILE *f; | |
90 | int err; | |
91 | ||
92 | f = open_map(MAP_NEW); | |
93 | ||
94 | if (!f) | |
95 | return 0; | |
96 | for (; mel; mel = mel->next) { | |
97 | if (mel->bad) | |
98 | continue; | |
99 | if (mel->devnum < 0) | |
100 | fprintf(f, "mdp%d ", -1-mel->devnum); | |
101 | else | |
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?:""); | |
107 | } | |
108 | fflush(f); | |
109 | err = ferror(f); | |
110 | fclose(f); | |
111 | if (err) { | |
112 | unlink(mapname[1]); | |
113 | return 0; | |
114 | } | |
115 | return rename(mapname[1], | |
116 | mapname[0]) == 0; | |
117 | } | |
118 | ||
119 | ||
120 | static FILE *lf = NULL; | |
121 | int map_lock(struct map_ent **melp) | |
122 | { | |
123 | while (lf == NULL) { | |
124 | struct stat buf; | |
125 | lf = open_map(MAP_LOCK); | |
126 | if (lf == NULL) | |
127 | return -1; | |
128 | if (flock(fileno(lf), LOCK_EX) != 0) { | |
129 | fclose(lf); | |
130 | lf = NULL; | |
131 | return -1; | |
132 | } | |
133 | if (fstat(fileno(lf), &buf) != 0 || | |
134 | buf.st_nlink == 0) { | |
135 | /* The owner of the lock unlinked it, | |
136 | * so we have a lock on a stale file, | |
137 | * try again | |
138 | */ | |
139 | fclose(lf); | |
140 | lf = NULL; | |
141 | } | |
142 | } | |
143 | if (*melp) | |
144 | map_free(*melp); | |
145 | map_read(melp); | |
146 | return 0; | |
147 | } | |
148 | ||
149 | void map_unlock(struct map_ent **melp) | |
150 | { | |
151 | if (lf) { | |
152 | /* must unlink before closing the file, | |
153 | * as only the owner of the lock may | |
154 | * unlink the file | |
155 | */ | |
156 | unlink(mapname[2]); | |
157 | fclose(lf); | |
158 | } | |
159 | lf = NULL; | |
160 | } | |
161 | ||
162 | void map_fork(void) | |
163 | { | |
164 | /* We are forking, so must close the lock file. | |
165 | * Don't risk flushing anything though. | |
166 | */ | |
167 | if (lf) { | |
168 | close(fileno(lf)); | |
169 | fclose(lf); | |
170 | lf = NULL; | |
171 | } | |
172 | } | |
173 | ||
174 | void map_add(struct map_ent **melp, | |
175 | int devnum, char *metadata, int uuid[4], char *path) | |
176 | { | |
177 | struct map_ent *me = malloc(sizeof(*me)); | |
178 | ||
179 | me->devnum = devnum; | |
180 | strcpy(me->metadata, metadata); | |
181 | memcpy(me->uuid, uuid, 16); | |
182 | me->path = path ? strdup(path) : NULL; | |
183 | me->next = *melp; | |
184 | me->bad = 0; | |
185 | *melp = me; | |
186 | } | |
187 | ||
188 | void map_read(struct map_ent **melp) | |
189 | { | |
190 | FILE *f; | |
191 | char buf[8192]; | |
192 | char path[200]; | |
193 | int devnum, uuid[4]; | |
194 | char metadata[30]; | |
195 | char nam[4]; | |
196 | ||
197 | *melp = NULL; | |
198 | ||
199 | f = open_map(MAP_READ); | |
200 | if (!f) { | |
201 | RebuildMap(); | |
202 | f = open_map(MAP_READ); | |
203 | } | |
204 | if (!f) | |
205 | return; | |
206 | ||
207 | while (fgets(buf, sizeof(buf), f)) { | |
208 | path[0] = 0; | |
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) | |
213 | continue; | |
214 | if (nam[2] == 'p') | |
215 | devnum = -1 - devnum; | |
216 | map_add(melp, devnum, metadata, uuid, path); | |
217 | } | |
218 | } | |
219 | fclose(f); | |
220 | } | |
221 | ||
222 | void map_free(struct map_ent *map) | |
223 | { | |
224 | while (map) { | |
225 | struct map_ent *mp = map; | |
226 | map = mp->next; | |
227 | free(mp->path); | |
228 | free(mp); | |
229 | } | |
230 | } | |
231 | ||
232 | int map_update(struct map_ent **mpp, int devnum, char *metadata, | |
233 | int *uuid, char *path) | |
234 | { | |
235 | struct map_ent *map, *mp; | |
236 | int rv; | |
237 | ||
238 | if (mpp && *mpp) | |
239 | map = *mpp; | |
240 | else | |
241 | map_read(&map); | |
242 | ||
243 | for (mp = map ; mp ; mp=mp->next) | |
244 | if (mp->devnum == devnum) { | |
245 | strcpy(mp->metadata, metadata); | |
246 | memcpy(mp->uuid, uuid, 16); | |
247 | free(mp->path); | |
248 | mp->path = path ? strdup(path) : NULL; | |
249 | mp->bad = 0; | |
250 | break; | |
251 | } | |
252 | if (!mp) | |
253 | map_add(&map, devnum, metadata, uuid, path); | |
254 | if (mpp) | |
255 | *mpp = NULL; | |
256 | rv = map_write(map); | |
257 | map_free(map); | |
258 | return rv; | |
259 | } | |
260 | ||
261 | void map_delete(struct map_ent **mapp, int devnum) | |
262 | { | |
263 | struct map_ent *mp; | |
264 | ||
265 | if (*mapp == NULL) | |
266 | map_read(mapp); | |
267 | ||
268 | for (mp = *mapp; mp; mp = *mapp) { | |
269 | if (mp->devnum == devnum) { | |
270 | *mapp = mp->next; | |
271 | free(mp->path); | |
272 | free(mp); | |
273 | } else | |
274 | mapp = & mp->next; | |
275 | } | |
276 | } | |
277 | ||
278 | void map_remove(struct map_ent **mapp, int devnum) | |
279 | { | |
280 | if (devnum == NoMdDev) | |
281 | return; | |
282 | ||
283 | map_delete(mapp, devnum); | |
284 | map_write(*mapp); | |
285 | map_free(*mapp); | |
286 | } | |
287 | ||
288 | struct map_ent *map_by_uuid(struct map_ent **map, int uuid[4]) | |
289 | { | |
290 | struct map_ent *mp; | |
291 | if (!*map) | |
292 | map_read(map); | |
293 | ||
294 | for (mp = *map ; mp ; mp = mp->next) { | |
295 | if (memcmp(uuid, mp->uuid, 16) != 0) | |
296 | continue; | |
297 | if (!mddev_busy(mp->devnum)) { | |
298 | mp->bad = 1; | |
299 | continue; | |
300 | } | |
301 | return mp; | |
302 | } | |
303 | return NULL; | |
304 | } | |
305 | ||
306 | struct map_ent *map_by_devnum(struct map_ent **map, int devnum) | |
307 | { | |
308 | struct map_ent *mp; | |
309 | if (!*map) | |
310 | map_read(map); | |
311 | ||
312 | for (mp = *map ; mp ; mp = mp->next) { | |
313 | if (mp->devnum != devnum) | |
314 | continue; | |
315 | if (!mddev_busy(mp->devnum)) { | |
316 | mp->bad = 1; | |
317 | continue; | |
318 | } | |
319 | return mp; | |
320 | } | |
321 | return NULL; | |
322 | } | |
323 | ||
324 | struct map_ent *map_by_name(struct map_ent **map, char *name) | |
325 | { | |
326 | struct map_ent *mp; | |
327 | if (!*map) | |
328 | map_read(map); | |
329 | ||
330 | for (mp = *map ; mp ; mp = mp->next) { | |
331 | if (!mp->path) | |
332 | continue; | |
333 | if (strncmp(mp->path, "/dev/md/", 8) != 0) | |
334 | continue; | |
335 | if (strcmp(mp->path+8, name) != 0) | |
336 | continue; | |
337 | if (!mddev_busy(mp->devnum)) { | |
338 | mp->bad = 1; | |
339 | continue; | |
340 | } | |
341 | return mp; | |
342 | } | |
343 | return NULL; | |
344 | } | |
345 | ||
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() | |
349 | */ | |
350 | static char *get_member_info(struct mdstat_ent *ent) | |
351 | { | |
352 | ||
353 | if (ent->metadata_version == NULL || | |
354 | strncmp(ent->metadata_version, "external:", 9) != 0) | |
355 | return NULL; | |
356 | ||
357 | if (is_subarray(&ent->metadata_version[9])) { | |
358 | char *subarray; | |
359 | ||
360 | subarray = strrchr(ent->metadata_version, '/'); | |
361 | return subarray + 1; | |
362 | } | |
363 | return NULL; | |
364 | } | |
365 | ||
366 | void RebuildMap(void) | |
367 | { | |
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); | |
375 | ||
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; | |
380 | } | |
381 | } | |
382 | ||
383 | for (md = mdstat ; md ; md = md->next) { | |
384 | struct mdinfo *sra = sysfs_read(-1, md->devnum, GET_DEVS); | |
385 | struct mdinfo *sd; | |
386 | ||
387 | if (!sra) | |
388 | continue; | |
389 | ||
390 | for (sd = sra->devs ; sd ; sd = sd->next) { | |
391 | char namebuf[100]; | |
392 | char dn[30]; | |
393 | int dfd; | |
394 | int ok; | |
395 | struct supertype *st; | |
396 | char *subarray = NULL; | |
397 | char *path; | |
398 | struct mdinfo *info; | |
399 | ||
400 | sprintf(dn, "%d:%d", sd->disk.major, sd->disk.minor); | |
401 | dfd = dev_open(dn, O_RDONLY); | |
402 | if (dfd < 0) | |
403 | continue; | |
404 | st = guess_super(dfd); | |
405 | if ( st == NULL) | |
406 | ok = -1; | |
407 | else { | |
408 | subarray = get_member_info(md); | |
409 | ok = st->ss->load_super(st, dfd, NULL); | |
410 | } | |
411 | close(dfd); | |
412 | if (ok != 0) | |
413 | continue; | |
414 | info = st->ss->container_content(st, subarray); | |
415 | ||
416 | if (md->devnum >= 0) | |
417 | path = map_dev(MD_MAJOR, md->devnum, 0); | |
418 | else | |
419 | path = map_dev(mdp, (-1-md->devnum)<< 6, 0); | |
420 | if (path == NULL || | |
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 | |
427 | * up with. | |
428 | * That means: | |
429 | * Check if array is in mdadm.conf | |
430 | * - if so use that. | |
431 | * determine trustworthy from homehost etc | |
432 | * find a unique name based on metadata name. | |
433 | * | |
434 | */ | |
435 | struct mddev_ident *match = conf_match(st, info, | |
436 | NULL, 0, | |
437 | NULL); | |
438 | struct stat stb; | |
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); | |
444 | path = namebuf; | |
445 | } | |
446 | } else { | |
447 | int unum = 0; | |
448 | char *sep = "_"; | |
449 | const char *name; | |
450 | int conflict = 1; | |
451 | if ((homehost == NULL || | |
452 | st->ss->match_home(st, homehost) != 1) && | |
453 | st->ss->match_home(st, "any") != 1 && | |
454 | (require_homehost | |
455 | || ! conf_name_is_free(info->name))) | |
456 | /* require a numeric suffix */ | |
457 | unum = 0; | |
458 | else | |
459 | /* allow name to be used as-is if no conflict */ | |
460 | unum = -1; | |
461 | name = info->name; | |
462 | if (!*name) { | |
463 | name = st->ss->name; | |
464 | if (!isdigit(name[strlen(name)-1]) && | |
465 | unum == -1) { | |
466 | unum = 0; | |
467 | sep = ""; | |
468 | } | |
469 | } | |
470 | if (strchr(name, ':')) | |
471 | /* probably a uniquifying | |
472 | * hostname prefix. Allow | |
473 | * without a suffix | |
474 | */ | |
475 | unum = -1; | |
476 | ||
477 | while (conflict) { | |
478 | if (unum >= 0) | |
479 | sprintf(namebuf, "/dev/md/%s%s%d", | |
480 | name, sep, unum); | |
481 | else | |
482 | sprintf(namebuf, "/dev/md/%s", | |
483 | name); | |
484 | unum++; | |
485 | if (lstat(namebuf, &stb) != 0 && | |
486 | (map == NULL || | |
487 | !map_by_name(&map, namebuf+8))) | |
488 | conflict = 0; | |
489 | } | |
490 | path = namebuf; | |
491 | } | |
492 | } | |
493 | map_add(&map, md->devnum, | |
494 | info->text_version, | |
495 | info->uuid, path); | |
496 | st->ss->free_super(st); | |
497 | free(info); | |
498 | break; | |
499 | } | |
500 | sysfs_free(sra); | |
501 | } | |
502 | /* Only trigger a change if we wrote a new map file */ | |
503 | if (map_write(map)) | |
504 | for (md = mdstat ; md ; md = md->next) { | |
505 | struct mdinfo *sra = sysfs_read(-1, md->devnum, | |
506 | GET_VERSION); | |
507 | if (sra) | |
508 | sysfs_uevent(sra, "change"); | |
509 | sysfs_free(sra); | |
510 | } | |
511 | map_free(map); | |
512 | free_mdstat(mdstat); | |
513 | } |