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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 is /run/mdadm/map. Distros and users | |
42 | * which have not switched to /run yet can choose a different location | |
43 | * at compile time via MAP_DIR and MAP_FILE. | |
44 | */ | |
45 | #include "mdadm.h" | |
46 | #include <sys/file.h> | |
47 | #include <ctype.h> | |
48 | ||
49 | #define MAP_READ 0 | |
50 | #define MAP_NEW 1 | |
51 | #define MAP_LOCK 2 | |
52 | #define MAP_DIRNAME 3 | |
53 | ||
54 | char *mapname[4] = { | |
55 | MAP_DIR "/" MAP_FILE, | |
56 | MAP_DIR "/" MAP_FILE ".new", | |
57 | MAP_DIR "/" MAP_FILE ".lock", | |
58 | MAP_DIR | |
59 | }; | |
60 | ||
61 | int mapmode[3] = { O_RDONLY, O_RDWR|O_CREAT, O_RDWR|O_CREAT|O_TRUNC }; | |
62 | char *mapsmode[3] = { "r", "w", "w"}; | |
63 | ||
64 | FILE *open_map(int modenum) | |
65 | { | |
66 | int fd; | |
67 | if ((mapmode[modenum] & O_CREAT)) | |
68 | /* Attempt to create directory, don't worry about | |
69 | * failure. | |
70 | */ | |
71 | (void)mkdir(mapname[MAP_DIRNAME], 0755); | |
72 | fd = open(mapname[modenum], mapmode[modenum], 0600); | |
73 | if (fd >= 0) | |
74 | return fdopen(fd, mapsmode[modenum]); | |
75 | return NULL; | |
76 | } | |
77 | ||
78 | int map_write(struct map_ent *mel) | |
79 | { | |
80 | FILE *f; | |
81 | int err; | |
82 | ||
83 | f = open_map(MAP_NEW); | |
84 | ||
85 | if (!f) | |
86 | return 0; | |
87 | for (; mel; mel = mel->next) { | |
88 | if (mel->bad) | |
89 | continue; | |
90 | fprintf(f, "%s ", mel->devnm); | |
91 | fprintf(f, "%s ", mel->metadata); | |
92 | fprintf(f, "%08x:%08x:%08x:%08x ", mel->uuid[0], | |
93 | mel->uuid[1], mel->uuid[2], mel->uuid[3]); | |
94 | fprintf(f, "%s\n", mel->path?:""); | |
95 | } | |
96 | fflush(f); | |
97 | err = ferror(f); | |
98 | fclose(f); | |
99 | if (err) { | |
100 | unlink(mapname[1]); | |
101 | return 0; | |
102 | } | |
103 | return rename(mapname[1], | |
104 | mapname[0]) == 0; | |
105 | } | |
106 | ||
107 | static FILE *lf = NULL; | |
108 | int map_lock(struct map_ent **melp) | |
109 | { | |
110 | while (lf == NULL) { | |
111 | struct stat buf; | |
112 | lf = open_map(MAP_LOCK); | |
113 | if (lf == NULL) | |
114 | return -1; | |
115 | if (flock(fileno(lf), LOCK_EX) != 0) { | |
116 | fclose(lf); | |
117 | lf = NULL; | |
118 | return -1; | |
119 | } | |
120 | if (fstat(fileno(lf), &buf) != 0 || | |
121 | buf.st_nlink == 0) { | |
122 | /* The owner of the lock unlinked it, | |
123 | * so we have a lock on a stale file, | |
124 | * try again | |
125 | */ | |
126 | fclose(lf); | |
127 | lf = NULL; | |
128 | } | |
129 | } | |
130 | if (*melp) | |
131 | map_free(*melp); | |
132 | map_read(melp); | |
133 | return 0; | |
134 | } | |
135 | ||
136 | void map_unlock(struct map_ent **melp) | |
137 | { | |
138 | if (lf) { | |
139 | /* must unlink before closing the file, | |
140 | * as only the owner of the lock may | |
141 | * unlink the file | |
142 | */ | |
143 | unlink(mapname[2]); | |
144 | fclose(lf); | |
145 | } | |
146 | lf = NULL; | |
147 | } | |
148 | ||
149 | void map_fork(void) | |
150 | { | |
151 | /* We are forking, so must close the lock file. | |
152 | * Don't risk flushing anything though. | |
153 | */ | |
154 | if (lf) { | |
155 | close(fileno(lf)); | |
156 | fclose(lf); | |
157 | lf = NULL; | |
158 | } | |
159 | } | |
160 | ||
161 | void map_add(struct map_ent **melp, | |
162 | char * devnm, char *metadata, int uuid[4], char *path) | |
163 | { | |
164 | struct map_ent *me = xmalloc(sizeof(*me)); | |
165 | ||
166 | strcpy(me->devnm, devnm); | |
167 | strcpy(me->metadata, metadata); | |
168 | memcpy(me->uuid, uuid, 16); | |
169 | me->path = path ? xstrdup(path) : NULL; | |
170 | me->next = *melp; | |
171 | me->bad = 0; | |
172 | *melp = me; | |
173 | } | |
174 | ||
175 | void map_read(struct map_ent **melp) | |
176 | { | |
177 | FILE *f; | |
178 | char buf[8192]; | |
179 | char path[201]; | |
180 | int uuid[4]; | |
181 | char devnm[32]; | |
182 | char metadata[30]; | |
183 | ||
184 | *melp = NULL; | |
185 | ||
186 | f = open_map(MAP_READ); | |
187 | if (!f) { | |
188 | RebuildMap(); | |
189 | f = open_map(MAP_READ); | |
190 | } | |
191 | if (!f) | |
192 | return; | |
193 | ||
194 | while (fgets(buf, sizeof(buf), f)) { | |
195 | path[0] = 0; | |
196 | if (sscanf(buf, " %s %s %x:%x:%x:%x %200s", | |
197 | devnm, metadata, uuid, uuid+1, | |
198 | uuid+2, uuid+3, path) >= 7) { | |
199 | map_add(melp, devnm, metadata, uuid, path); | |
200 | } | |
201 | } | |
202 | fclose(f); | |
203 | } | |
204 | ||
205 | void map_free(struct map_ent *map) | |
206 | { | |
207 | while (map) { | |
208 | struct map_ent *mp = map; | |
209 | map = mp->next; | |
210 | free(mp->path); | |
211 | free(mp); | |
212 | } | |
213 | } | |
214 | ||
215 | int map_update(struct map_ent **mpp, char *devnm, char *metadata, | |
216 | int *uuid, char *path) | |
217 | { | |
218 | struct map_ent *map, *mp; | |
219 | int rv; | |
220 | ||
221 | if (mpp && *mpp) | |
222 | map = *mpp; | |
223 | else | |
224 | map_read(&map); | |
225 | ||
226 | for (mp = map ; mp ; mp=mp->next) | |
227 | if (strcmp(mp->devnm, devnm) == 0) { | |
228 | strcpy(mp->metadata, metadata); | |
229 | memcpy(mp->uuid, uuid, 16); | |
230 | free(mp->path); | |
231 | mp->path = path ? xstrdup(path) : NULL; | |
232 | mp->bad = 0; | |
233 | break; | |
234 | } | |
235 | if (!mp) | |
236 | map_add(&map, devnm, metadata, uuid, path); | |
237 | if (mpp) | |
238 | *mpp = NULL; | |
239 | rv = map_write(map); | |
240 | map_free(map); | |
241 | return rv; | |
242 | } | |
243 | ||
244 | void map_delete(struct map_ent **mapp, char *devnm) | |
245 | { | |
246 | struct map_ent *mp; | |
247 | ||
248 | if (*mapp == NULL) | |
249 | map_read(mapp); | |
250 | ||
251 | for (mp = *mapp; mp; mp = *mapp) { | |
252 | if (strcmp(mp->devnm, devnm) == 0) { | |
253 | *mapp = mp->next; | |
254 | free(mp->path); | |
255 | free(mp); | |
256 | } else | |
257 | mapp = & mp->next; | |
258 | } | |
259 | } | |
260 | ||
261 | void map_remove(struct map_ent **mapp, char *devnm) | |
262 | { | |
263 | if (devnm[0] == 0) | |
264 | return; | |
265 | ||
266 | map_delete(mapp, devnm); | |
267 | map_write(*mapp); | |
268 | map_free(*mapp); | |
269 | } | |
270 | ||
271 | struct map_ent *map_by_uuid(struct map_ent **map, int uuid[4]) | |
272 | { | |
273 | struct map_ent *mp; | |
274 | if (!*map) | |
275 | map_read(map); | |
276 | ||
277 | for (mp = *map ; mp ; mp = mp->next) { | |
278 | if (memcmp(uuid, mp->uuid, 16) != 0) | |
279 | continue; | |
280 | if (!mddev_busy(mp->devnm)) { | |
281 | mp->bad = 1; | |
282 | continue; | |
283 | } | |
284 | return mp; | |
285 | } | |
286 | return NULL; | |
287 | } | |
288 | ||
289 | struct map_ent *map_by_devnm(struct map_ent **map, char *devnm) | |
290 | { | |
291 | struct map_ent *mp; | |
292 | if (!*map) | |
293 | map_read(map); | |
294 | ||
295 | for (mp = *map ; mp ; mp = mp->next) { | |
296 | if (strcmp(mp->devnm, devnm) != 0) | |
297 | continue; | |
298 | if (!mddev_busy(mp->devnm)) { | |
299 | mp->bad = 1; | |
300 | continue; | |
301 | } | |
302 | return mp; | |
303 | } | |
304 | return NULL; | |
305 | } | |
306 | ||
307 | struct map_ent *map_by_name(struct map_ent **map, char *name) | |
308 | { | |
309 | struct map_ent *mp; | |
310 | if (!*map) | |
311 | map_read(map); | |
312 | ||
313 | for (mp = *map ; mp ; mp = mp->next) { | |
314 | if (!mp->path) | |
315 | continue; | |
316 | if (strncmp(mp->path, "/dev/md/", 8) != 0) | |
317 | continue; | |
318 | if (strcmp(mp->path+8, name) != 0) | |
319 | continue; | |
320 | if (!mddev_busy(mp->devnm)) { | |
321 | mp->bad = 1; | |
322 | continue; | |
323 | } | |
324 | return mp; | |
325 | } | |
326 | return NULL; | |
327 | } | |
328 | ||
329 | /* sets the proper subarray and container_dev according to the metadata | |
330 | * version super_by_fd does this automatically, this routine is meant as | |
331 | * a supplement for guess_super() | |
332 | */ | |
333 | static char *get_member_info(struct mdstat_ent *ent) | |
334 | { | |
335 | ||
336 | if (ent->metadata_version == NULL || | |
337 | strncmp(ent->metadata_version, "external:", 9) != 0) | |
338 | return NULL; | |
339 | ||
340 | if (is_subarray(&ent->metadata_version[9])) { | |
341 | char *subarray; | |
342 | ||
343 | subarray = strrchr(ent->metadata_version, '/'); | |
344 | return subarray + 1; | |
345 | } | |
346 | return NULL; | |
347 | } | |
348 | ||
349 | void RebuildMap(void) | |
350 | { | |
351 | struct mdstat_ent *mdstat = mdstat_read(0, 0); | |
352 | struct mdstat_ent *md; | |
353 | struct map_ent *map = NULL; | |
354 | int require_homehost; | |
355 | char sys_hostname[256]; | |
356 | char *homehost = conf_get_homehost(&require_homehost); | |
357 | ||
358 | if (homehost == NULL || strcmp(homehost, "<system>")==0) { | |
359 | if (gethostname(sys_hostname, sizeof(sys_hostname)) == 0) { | |
360 | sys_hostname[sizeof(sys_hostname)-1] = 0; | |
361 | homehost = sys_hostname; | |
362 | } | |
363 | } | |
364 | ||
365 | for (md = mdstat ; md ; md = md->next) { | |
366 | struct mdinfo *sra = sysfs_read(-1, md->devnm, GET_DEVS); | |
367 | struct mdinfo *sd; | |
368 | ||
369 | if (!sra) | |
370 | continue; | |
371 | ||
372 | for (sd = sra->devs ; sd ; sd = sd->next) { | |
373 | char namebuf[100]; | |
374 | char dn[30]; | |
375 | int dfd; | |
376 | int ok; | |
377 | dev_t devid; | |
378 | struct supertype *st; | |
379 | char *subarray = NULL; | |
380 | char *path; | |
381 | struct mdinfo *info; | |
382 | ||
383 | sprintf(dn, "%d:%d", sd->disk.major, sd->disk.minor); | |
384 | dfd = dev_open(dn, O_RDONLY); | |
385 | if (dfd < 0) | |
386 | continue; | |
387 | st = guess_super(dfd); | |
388 | if ( st == NULL) | |
389 | ok = -1; | |
390 | else { | |
391 | subarray = get_member_info(md); | |
392 | ok = st->ss->load_super(st, dfd, NULL); | |
393 | } | |
394 | close(dfd); | |
395 | if (ok != 0) | |
396 | continue; | |
397 | if (subarray) | |
398 | info = st->ss->container_content(st, subarray); | |
399 | else { | |
400 | info = xmalloc(sizeof(*info)); | |
401 | st->ss->getinfo_super(st, info, NULL); | |
402 | } | |
403 | if (!info) | |
404 | continue; | |
405 | ||
406 | devid = devnm2devid(md->devnm); | |
407 | path = map_dev(major(devid), minor(devid), 0); | |
408 | if (path == NULL || | |
409 | strncmp(path, "/dev/md/", 8) != 0) { | |
410 | /* We would really like a name that provides | |
411 | * an MD_DEVNAME for udev. | |
412 | * The name needs to be unique both in /dev/md/ | |
413 | * and in this mapfile. | |
414 | * It needs to match what -I or -As would come | |
415 | * up with. | |
416 | * That means: | |
417 | * Check if array is in mdadm.conf | |
418 | * - if so use that. | |
419 | * determine trustworthy from homehost etc | |
420 | * find a unique name based on metadata name. | |
421 | * | |
422 | */ | |
423 | struct mddev_ident *match = conf_match(st, info, | |
424 | NULL, 0, | |
425 | NULL); | |
426 | struct stat stb; | |
427 | if (match && match->devname && match->devname[0] == '/') { | |
428 | path = match->devname; | |
429 | if (path[0] != '/') { | |
430 | strcpy(namebuf, "/dev/md/"); | |
431 | strcat(namebuf, path); | |
432 | path = namebuf; | |
433 | } | |
434 | } else { | |
435 | int unum = 0; | |
436 | char *sep = "_"; | |
437 | const char *name; | |
438 | int conflict = 1; | |
439 | if ((homehost == NULL || | |
440 | st->ss->match_home(st, homehost) != 1) && | |
441 | st->ss->match_home(st, "any") != 1 && | |
442 | (require_homehost | |
443 | || ! conf_name_is_free(info->name))) | |
444 | /* require a numeric suffix */ | |
445 | unum = 0; | |
446 | else | |
447 | /* allow name to be used as-is if no conflict */ | |
448 | unum = -1; | |
449 | name = info->name; | |
450 | if (!*name) { | |
451 | name = st->ss->name; | |
452 | if (!isdigit(name[strlen(name)-1]) && | |
453 | unum == -1) { | |
454 | unum = 0; | |
455 | sep = ""; | |
456 | } | |
457 | } | |
458 | if (strchr(name, ':')) { | |
459 | /* Probably a uniquifying | |
460 | * hostname prefix. Allow | |
461 | * without a suffix, and strip | |
462 | * hostname if it is us. | |
463 | */ | |
464 | if (homehost && unum == -1 && | |
465 | strncmp(name, homehost, | |
466 | strlen(homehost)) == 0 && | |
467 | name[strlen(homehost)] == ':') | |
468 | name += strlen(homehost)+1; | |
469 | unum = -1; | |
470 | } | |
471 | ||
472 | while (conflict) { | |
473 | if (unum >= 0) | |
474 | sprintf(namebuf, "/dev/md/%s%s%d", | |
475 | name, sep, unum); | |
476 | else | |
477 | sprintf(namebuf, "/dev/md/%s", | |
478 | name); | |
479 | unum++; | |
480 | if (lstat(namebuf, &stb) != 0 && | |
481 | (map == NULL || | |
482 | !map_by_name(&map, namebuf+8))) | |
483 | conflict = 0; | |
484 | } | |
485 | path = namebuf; | |
486 | } | |
487 | } | |
488 | map_add(&map, md->devnm, | |
489 | info->text_version, | |
490 | info->uuid, path); | |
491 | st->ss->free_super(st); | |
492 | free(info); | |
493 | break; | |
494 | } | |
495 | sysfs_free(sra); | |
496 | } | |
497 | /* Only trigger a change if we wrote a new map file */ | |
498 | if (map_write(map)) | |
499 | for (md = mdstat ; md ; md = md->next) { | |
500 | struct mdinfo *sra = sysfs_read(-1, md->devnm, | |
501 | GET_VERSION); | |
502 | if (sra) | |
503 | sysfs_uevent(sra, "change"); | |
504 | sysfs_free(sra); | |
505 | } | |
506 | map_free(map); | |
507 | free_mdstat(mdstat); | |
508 | } |