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git.ipfire.org Git - thirdparty/mdadm.git/blob - mapfile.c
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 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.
56 MAP_DIR
"/" MAP_FILE
".new",
57 MAP_DIR
"/" MAP_FILE
".lock",
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
)
67 if ((mapmode
[modenum
] & O_CREAT
))
68 /* Attempt to create directory, don't worry about
71 (void)mkdir(mapname
[MAP_DIRNAME
], 0755);
72 fd
= open(mapname
[modenum
], mapmode
[modenum
], 0600);
74 return fdopen(fd
, mapsmode
[modenum
]);
78 int map_write(struct map_ent
*mel
)
83 f
= open_map(MAP_NEW
);
87 for (; mel
; mel
= mel
->next
) {
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
?:"");
103 return rename(mapname
[1],
107 static FILE *lf
= NULL
;
108 int map_lock(struct map_ent
**melp
)
112 lf
= open_map(MAP_LOCK
);
115 if (flock(fileno(lf
), LOCK_EX
) != 0) {
120 if (fstat(fileno(lf
), &buf
) != 0 ||
122 /* The owner of the lock unlinked it,
123 * so we have a lock on a stale file,
136 void map_unlock(struct map_ent
**melp
)
139 /* must unlink before closing the file,
140 * as only the owner of the lock may
151 /* We are forking, so must close the lock file.
152 * Don't risk flushing anything though.
161 void map_add(struct map_ent
**melp
,
162 char * devnm
, char *metadata
, int uuid
[4], char *path
)
164 struct map_ent
*me
= xmalloc(sizeof(*me
));
166 strcpy(me
->devnm
, devnm
);
167 strcpy(me
->metadata
, metadata
);
168 memcpy(me
->uuid
, uuid
, 16);
169 me
->path
= path
? xstrdup(path
) : NULL
;
175 void map_read(struct map_ent
**melp
)
186 f
= open_map(MAP_READ
);
189 f
= open_map(MAP_READ
);
194 while (fgets(buf
, sizeof(buf
), f
)) {
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
);
205 void map_free(struct map_ent
*map
)
208 struct map_ent
*mp
= map
;
215 int map_update(struct map_ent
**mpp
, char *devnm
, char *metadata
,
216 int *uuid
, char *path
)
218 struct map_ent
*map
, *mp
;
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);
231 mp
->path
= path
? xstrdup(path
) : NULL
;
236 map_add(&map
, devnm
, metadata
, uuid
, path
);
244 void map_delete(struct map_ent
**mapp
, char *devnm
)
251 for (mp
= *mapp
; mp
; mp
= *mapp
) {
252 if (strcmp(mp
->devnm
, devnm
) == 0) {
261 void map_remove(struct map_ent
**mapp
, char *devnm
)
266 map_delete(mapp
, devnm
);
271 struct map_ent
*map_by_uuid(struct map_ent
**map
, int uuid
[4])
277 for (mp
= *map
; mp
; mp
= mp
->next
) {
278 if (memcmp(uuid
, mp
->uuid
, 16) != 0)
280 if (!mddev_busy(mp
->devnm
)) {
289 struct map_ent
*map_by_devnm(struct map_ent
**map
, char *devnm
)
295 for (mp
= *map
; mp
; mp
= mp
->next
) {
296 if (strcmp(mp
->devnm
, devnm
) != 0)
298 if (!mddev_busy(mp
->devnm
)) {
307 struct map_ent
*map_by_name(struct map_ent
**map
, char *name
)
313 for (mp
= *map
; mp
; mp
= mp
->next
) {
316 if (strncmp(mp
->path
, "/dev/md/", 8) != 0)
318 if (strcmp(mp
->path
+8, name
) != 0)
320 if (!mddev_busy(mp
->devnm
)) {
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()
333 static char *get_member_info(struct mdstat_ent
*ent
)
336 if (ent
->metadata_version
== NULL
||
337 strncmp(ent
->metadata_version
, "external:", 9) != 0)
340 if (is_subarray(&ent
->metadata_version
[9])) {
343 subarray
= strrchr(ent
->metadata_version
, '/');
349 void RebuildMap(void)
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
);
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
;
365 for (md
= mdstat
; md
; md
= md
->next
) {
366 struct mdinfo
*sra
= sysfs_read(-1, md
->devnm
, GET_DEVS
);
372 for (sd
= sra
->devs
; sd
; sd
= sd
->next
) {
378 struct supertype
*st
;
379 char *subarray
= NULL
;
383 sprintf(dn
, "%d:%d", sd
->disk
.major
, sd
->disk
.minor
);
384 dfd
= dev_open(dn
, O_RDONLY
);
387 st
= guess_super(dfd
);
391 subarray
= get_member_info(md
);
392 ok
= st
->ss
->load_super(st
, dfd
, NULL
);
398 info
= st
->ss
->container_content(st
, subarray
);
400 info
= xmalloc(sizeof(*info
));
401 st
->ss
->getinfo_super(st
, info
, NULL
);
406 devid
= devnm2devid(md
->devnm
);
407 path
= map_dev(major(devid
), minor(devid
), 0);
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
417 * Check if array is in mdadm.conf
419 * determine trustworthy from homehost etc
420 * find a unique name based on metadata name.
423 struct mddev_ident
*match
= conf_match(st
, info
,
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
);
439 if ((homehost
== NULL
||
440 st
->ss
->match_home(st
, homehost
) != 1) &&
441 st
->ss
->match_home(st
, "any") != 1 &&
443 || ! conf_name_is_free(info
->name
)))
444 /* require a numeric suffix */
447 /* allow name to be used as-is if no conflict */
452 if (!isdigit(name
[strlen(name
)-1]) &&
458 if (strchr(name
, ':')) {
459 /* Probably a uniquifying
460 * hostname prefix. Allow
461 * without a suffix, and strip
462 * hostname if it is us.
464 if (homehost
&& unum
== -1 &&
465 strncmp(name
, homehost
,
466 strlen(homehost
)) == 0 &&
467 name
[strlen(homehost
)] == ':')
468 name
+= strlen(homehost
)+1;
474 sprintf(namebuf
, "/dev/md/%s%s%d",
477 sprintf(namebuf
, "/dev/md/%s",
480 if (lstat(namebuf
, &stb
) != 0 &&
482 !map_by_name(&map
, namebuf
+8)))
488 map_add(&map
, md
->devnm
,
491 st
->ss
->free_super(st
);
497 /* Only trigger a change if we wrote a new map file */
499 for (md
= mdstat
; md
; md
= md
->next
) {
500 struct mdinfo
*sra
= sysfs_read(-1, md
->devnm
,
503 sysfs_uevent(sra
, "change");