[thirdparty/mdadm.git] / mapfile.c

/*
 * mapfile - manage /var/run/mdadm.map. Part of:
 * mdadm - manage Linux "md" devices aka RAID arrays.
 *
 * Copyright (C) 2006-2009 Neil Brown <neilb@suse.de>
 *
 *
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 2 of the License, or
 *    (at your option) any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 *    Author: Neil Brown
 *    Email: <neilb@suse.de>
 *    Paper: Neil Brown
 *           Novell Inc
 *           GPO Box Q1283
 *           QVB Post Office, NSW 1230
 *           Australia
 */

/* /var/run/mdadm.map is used to track arrays being created in --incremental
 * more.  It particularly allows lookup from UUID to array device, but
 * also allows the array device name to be easily found.
 *
 * The map file is line based with space separated fields.  The fields are:
 *  Device id  -  mdX or mdpX  where X is a number.
 *  metadata   -  0.90 1.0 1.1 1.2 ddf ...
 *  UUID       -  uuid of the array
 *  path       -  path where device created: /dev/md/home
 *
 * The preferred location for the map file is /var/run/mdadm.map.
 * However /var/run may not exist or be writable in early boot.  And if
 * no-one has created /var/run/mdadm, we still want to survive.
 * So possible locations are:
 *   /var/run/mdadm/map  /var/run/mdadm.map  /dev/.mdadm.map
 * the last, because udev requires a writable /dev very early.
 * We read from the first one that exists and write to the first
 * one that we can.
 */
#include "mdadm.h"

#define mapnames(base) { #base, #base ".new", #base ".lock"}
char *mapname[3][3] = {
	mapnames(/var/run/mdadm/map),
	mapnames(/var/run/mdadm.map),
	mapnames(/dev/.mdadm.map)
};

int mapmode[3] = { O_RDONLY, O_RDWR|O_CREAT, O_RDWR|O_CREAT | O_TRUNC };
char *mapsmode[3] = { "r", "w", "w"};

FILE *open_map(int modenum, int *choice)
{
	int i;
	for (i = 0 ; i < 3 ; i++) {
		int fd = open(mapname[i][modenum], mapmode[modenum], 0600);
		if (fd >= 0) {
			*choice = i;
			return fdopen(fd, mapsmode[modenum]);
		}
	}
	return NULL;
}

int map_write(struct map_ent *mel)
{
	FILE *f;
	int err;
	int which;

	f = open_map(1, &which);

	if (!f)
		return 0;
	for (; mel; mel = mel->next) {
		if (mel->bad)
			continue;
		if (mel->devnum < 0)
			fprintf(f, "mdp%d ", -1-mel->devnum);
		else
			fprintf(f, "md%d ", mel->devnum);
		fprintf(f, "%s ", mel->metadata);
		fprintf(f, "%08x:%08x:%08x:%08x ", mel->uuid[0],
			mel->uuid[1], mel->uuid[2], mel->uuid[3]);
		fprintf(f, "%s\n", mel->path?:"");
	}
	fflush(f);
	err = ferror(f);
	fclose(f);
	if (err) {
		unlink(mapname[which][1]);
		return 0;
	}
	return rename(mapname[which][1],
		      mapname[which][0]) == 0;
}


static FILE *lf = NULL;
static int lwhich = 0;
int map_lock(struct map_ent **melp)
{
	if (lf == NULL) {
		lf = open_map(2, &lwhich);
		if (lf == NULL)
			return -1;
		if (lockf(fileno(lf), F_LOCK, 0) != 0) {
			fclose(lf);
			lf = NULL;
			return -1;
		}
	}
	if (*melp)
		map_free(*melp);
	map_read(melp);
	return 0;
}

void map_unlock(struct map_ent **melp)
{
	if (lf)
		fclose(lf);
	unlink(mapname[lwhich][2]);
	lf = NULL;
}

void map_add(struct map_ent **melp,
	    int devnum, char *metadata, int uuid[4], char *path)
{
	struct map_ent *me = malloc(sizeof(*me));

	me->devnum = devnum;
	strcpy(me->metadata, metadata);
	memcpy(me->uuid, uuid, 16);
	me->path = path ? strdup(path) : NULL;
	me->next = *melp;
	me->bad = 0;
	*melp = me;
}

void map_read(struct map_ent **melp)
{
	FILE *f;
	char buf[8192];
	char path[200];
	int devnum, uuid[4];
	char metadata[30];
	char nam[4];
	int which;

	*melp = NULL;

	f = open_map(0, &which);
	if (!f) {
		RebuildMap();
		f = open_map(0, &which);
	}
	if (!f)
		return;

	while (fgets(buf, sizeof(buf), f)) {
		path[0] = 0;
		if (sscanf(buf, " %3[mdp]%d %s %x:%x:%x:%x %200s",
			   nam, &devnum, metadata, uuid, uuid+1,
			   uuid+2, uuid+3, path) >= 7) {
			if (strncmp(nam, "md", 2) != 0)
				continue;
			if (nam[2] == 'p')
				devnum = -1 - devnum;
			map_add(melp, devnum, metadata, uuid, path);
		}
	}
	fclose(f);
}

void map_free(struct map_ent *map)
{
	while (map) {
		struct map_ent *mp = map;
		map = mp->next;
		free(mp->path);
		free(mp);
	}
}

int map_update(struct map_ent **mpp, int devnum, char *metadata,
	       int *uuid, char *path)
{
	struct map_ent *map, *mp;
	int rv;

	if (mpp && *mpp)
		map = *mpp;
	else
		map_read(&map);

	for (mp = map ; mp ; mp=mp->next)
		if (mp->devnum == devnum) {
			strcpy(mp->metadata, metadata);
			memcpy(mp->uuid, uuid, 16);
			free(mp->path);
			mp->path = path ? strdup(path) : NULL;
			break;
		}
	if (!mp)
		map_add(&map, devnum, metadata, uuid, path);
	if (mpp)
		*mpp = NULL;
	rv = map_write(map);
	map_free(map);
	return rv;
}

void map_delete(struct map_ent **mapp, int devnum)
{
	struct map_ent *mp;

	if (*mapp == NULL)
		map_read(mapp);

	for (mp = *mapp; mp; mp = *mapp) {
		if (mp->devnum == devnum) {
			*mapp = mp->next;
			free(mp->path);
			free(mp);
		} else
			mapp = & mp->next;
	}
}

struct map_ent *map_by_uuid(struct map_ent **map, int uuid[4])
{
	struct map_ent *mp;
	if (!*map)
		map_read(map);

	for (mp = *map ; mp ; mp = mp->next) {
		if (memcmp(uuid, mp->uuid, 16) != 0)
			continue;
		if (!mddev_busy(mp->devnum)) {
			mp->bad = 1;
			continue;
		}
		return mp;
	}
	return NULL;
}

struct map_ent *map_by_devnum(struct map_ent **map, int devnum)
{
	struct map_ent *mp;
	if (!*map)
		map_read(map);

	for (mp = *map ; mp ; mp = mp->next) {
		if (mp->devnum != devnum)
			continue;
		if (!mddev_busy(mp->devnum)) {
			mp->bad = 1;
			continue;
		}
		return mp;
	}
	return NULL;
}

struct map_ent *map_by_name(struct map_ent **map, char *name)
{
	struct map_ent *mp;
	if (!*map)
		map_read(map);

	for (mp = *map ; mp ; mp = mp->next) {
		if (!mp->path)
			continue;
		if (strncmp(mp->path, "/dev/md/", 8) != 0)
			continue;
		if (strcmp(mp->path+8, name) != 0)
			continue;
		if (!mddev_busy(mp->devnum)) {
			mp->bad = 1;
			continue;
		}
		return mp;
	}
	return NULL;
}

void RebuildMap(void)
{
	struct mdstat_ent *mdstat = mdstat_read(0, 0);
	struct mdstat_ent *md;
	struct map_ent *map = NULL;
	int mdp = get_mdp_major();

	for (md = mdstat ; md ; md = md->next) {
		struct mdinfo *sra = sysfs_read(-1, md->devnum, GET_DEVS|SKIP_GONE_DEVS);
		struct mdinfo *sd;

		if (!sra)
			continue;

		for (sd = sra->devs ; sd ; sd = sd->next) {
			char dn[30];
			int dfd;
			int ok;
			struct supertype *st;
			char *path;
			struct mdinfo info;

			sprintf(dn, "%d:%d", sd->disk.major, sd->disk.minor);
			dfd = dev_open(dn, O_RDONLY);
			if (dfd < 0)
				continue;
			st = guess_super(dfd);
			if ( st == NULL)
				ok = -1;
			else
				ok = st->ss->load_super(st, dfd, NULL);
			close(dfd);
			if (ok != 0)
				continue;
			st->ss->getinfo_super(st, &info);
			if (md->devnum >= 0)
				path = map_dev(MD_MAJOR, md->devnum, 0);
			else
				path = map_dev(mdp, (-1-md->devnum)<< 6, 0);
			map_add(&map, md->devnum,
				info.text_version,
				info.uuid, path);
			st->ss->free_super(st);
			break;
		}
		sysfs_free(sra);
	}
	map_write(map);
	map_free(map);
	for (md = mdstat ; md ; md = md->next) {
		struct mdinfo *sra = sysfs_read(-1, md->devnum, GET_VERSION);
		sysfs_uevent(sra, "change");
		sysfs_free(sra);
	}
	free_mdstat(mdstat);
}
Commit	Line	Data
8382f19b NB	1	/*
	2	* mapfile - manage /var/run/mdadm.map. Part of:
	3	* mdadm - manage Linux "md" devices aka RAID arrays.
	4	*
cf3a3d78	5	* Copyright (C) 2006-2009 Neil Brown <neilb@suse.de>
8382f19b NB	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	/* /var/run/mdadm.map is used to track arrays being created in --incremental
	32	* more. 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:
1522c538 NB	36	* Device id - mdX or mdpX where X is a number.
1522c538 NB	37	* metadata - 0.90 1.0 1.1 1.2 ddf ...
8382f19b NB	38	* UUID - uuid of the array
	39	* path - path where device created: /dev/md/home
	40	*
cf3a3d78 N	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 /dev/.mdadm.map
	46	* the last, because udev requires a writable /dev very early.
	47	* We read from the first one that exists and write to the first
	48	* one that we can.
8382f19b	49	*/
cf3a3d78	50	#include "mdadm.h"
8382f19b	51
cf3a3d78 N	52	#define mapnames(base) { #base, #base ".new", #base ".lock"}
	53	char *mapname[3][3] = {
	54	mapnames(/var/run/mdadm/map),
	55	mapnames(/var/run/mdadm.map),
	56	mapnames(/dev/.mdadm.map)
	57	};
8382f19b	58
cf3a3d78 N	59	int mapmode[3] = { O_RDONLY, O_RDWR\|O_CREAT, O_RDWR\|O_CREAT \| O_TRUNC };
cf3a3d78 N	60	char *mapsmode[3] = { "r", "w", "w"};
8382f19b	61
cf3a3d78 N	62	FILE open_map(int modenum, int choice)
	63	{
	64	int i;
	65	for (i = 0 ; i < 3 ; i++) {
	66	int fd = open(mapname[i][modenum], mapmode[modenum], 0600);
	67	if (fd >= 0) {
	68	*choice = i;
	69	return fdopen(fd, mapsmode[modenum]);
	70	}
	71	}
	72	return NULL;
	73	}
8382f19b NB	74
	75	int map_write(struct map_ent *mel)
	76	{
	77	FILE *f;
	78	int err;
cf3a3d78 N	79	int which;
	80
	81	f = open_map(1, &which);
8382f19b	82
8382f19b NB	83	if (!f)
8382f19b NB	84	return 0;
195254b8 N	85	for (; mel; mel = mel->next) {
	86	if (mel->bad)
	87	continue;
8382f19b NB	88	if (mel->devnum < 0)
	89	fprintf(f, "mdp%d ", -1-mel->devnum);
	90	else
	91	fprintf(f, "md%d ", mel->devnum);
1522c538	92	fprintf(f, "%s ", mel->metadata);
8382f19b NB	93	fprintf(f, "%08x:%08x:%08x:%08x ", mel->uuid[0],
8382f19b NB	94	mel->uuid[1], mel->uuid[2], mel->uuid[3]);
8615dcff	95	fprintf(f, "%s\n", mel->path?:"");
8382f19b NB	96	}
	97	fflush(f);
	98	err = ferror(f);
	99	fclose(f);
	100	if (err) {
cf3a3d78	101	unlink(mapname[which][1]);
8382f19b NB	102	return 0;
8382f19b NB	103	}
cf3a3d78 N	104	return rename(mapname[which][1],
cf3a3d78 N	105	mapname[which][0]) == 0;
8382f19b NB	106	}
8382f19b NB	107
ad5bc697	108
cf3a3d78 N	109	static FILE *lf = NULL;
cf3a3d78 N	110	static int lwhich = 0;
ad5bc697 N	111	int map_lock(struct map_ent **melp)
ad5bc697 N	112	{
cf3a3d78 N	113	if (lf == NULL) {
	114	lf = open_map(2, &lwhich);
	115	if (lf == NULL)
ad5bc697	116	return -1;
cf3a3d78 N	117	if (lockf(fileno(lf), F_LOCK, 0) != 0) {
	118	fclose(lf);
	119	lf = NULL;
ad5bc697 N	120	return -1;
	121	}
	122	}
	123	if (*melp)
	124	map_free(*melp);
	125	map_read(melp);
	126	return 0;
	127	}
	128
	129	void map_unlock(struct map_ent **melp)
	130	{
cf3a3d78 N	131	if (lf)
	132	fclose(lf);
	133	unlink(mapname[lwhich][2]);
	134	lf = NULL;
ad5bc697 N	135	}
ad5bc697 N	136
8382f19b	137	void map_add(struct map_ent **melp,
1522c538	138	int devnum, char metadata, int uuid[4], char path)
8382f19b NB	139	{
	140	struct map_ent me = malloc(sizeof(me));
	141
	142	me->devnum = devnum;
1522c538	143	strcpy(me->metadata, metadata);
8382f19b	144	memcpy(me->uuid, uuid, 16);
8615dcff	145	me->path = path ? strdup(path) : NULL;
8382f19b	146	me->next = *melp;
195254b8	147	me->bad = 0;
8382f19b NB	148	*melp = me;
	149	}
	150
	151	void map_read(struct map_ent **melp)
	152	{
	153	FILE *f;
	154	char buf[8192];
	155	char path[200];
1522c538 NB	156	int devnum, uuid[4];
1522c538 NB	157	char metadata[30];
8382f19b	158	char nam[4];
cf3a3d78	159	int which;
8382f19b NB	160
	161	*melp = NULL;
	162
cf3a3d78	163	f = open_map(0, &which);
3a56f223 N	164	if (!f) {
3a56f223 N	165	RebuildMap();
cf3a3d78	166	f = open_map(0, &which);
3a56f223	167	}
8382f19b NB	168	if (!f)
	169	return;
	170
	171	while (fgets(buf, sizeof(buf), f)) {
8615dcff	172	path[0] = 0;
c5afc314	173	if (sscanf(buf, " %3[mdp]%d %s %x:%x:%x:%x %200s",
1522c538	174	nam, &devnum, metadata, uuid, uuid+1,
8615dcff	175	uuid+2, uuid+3, path) >= 7) {
c5afc314 N	176	if (strncmp(nam, "md", 2) != 0)
	177	continue;
	178	if (nam[2] == 'p')
8382f19b	179	devnum = -1 - devnum;
1522c538	180	map_add(melp, devnum, metadata, uuid, path);
8382f19b NB	181	}
	182	}
	183	fclose(f);
	184	}
	185
	186	void map_free(struct map_ent *map)
	187	{
	188	while (map) {
	189	struct map_ent *mp = map;
	190	map = mp->next;
	191	free(mp->path);
	192	free(mp);
	193	}
	194	}
	195
1522c538	196	int map_update(struct map_ent *mpp, int devnum, char metadata,
8382f19b NB	197	int uuid, char path)
	198	{
	199	struct map_ent map, mp;
	200	int rv;
	201
	202	if (mpp && *mpp)
	203	map = *mpp;
	204	else
	205	map_read(&map);
	206
	207	for (mp = map ; mp ; mp=mp->next)
	208	if (mp->devnum == devnum) {
1522c538	209	strcpy(mp->metadata, metadata);
8382f19b NB	210	memcpy(mp->uuid, uuid, 16);
8382f19b NB	211	free(mp->path);
8615dcff	212	mp->path = path ? strdup(path) : NULL;
8382f19b NB	213	break;
	214	}
	215	if (!mp)
1522c538	216	map_add(&map, devnum, metadata, uuid, path);
a04d5763 N	217	if (mpp)
a04d5763 N	218	*mpp = NULL;
8382f19b NB	219	rv = map_write(map);
	220	map_free(map);
	221	return rv;
	222	}
	223
	224	void map_delete(struct map_ent **mapp, int devnum)
	225	{
	226	struct map_ent *mp;
	227
	228	if (*mapp == NULL)
	229	map_read(mapp);
	230
	231	for (mp = mapp; mp; mp = mapp) {
	232	if (mp->devnum == devnum) {
	233	*mapp = mp->next;
	234	free(mp->path);
	235	free(mp);
	236	} else
	237	mapp = & mp->next;
	238	}
	239	}
	240
	241	struct map_ent map_by_uuid(struct map_ent *map, int uuid[4])
	242	{
	243	struct map_ent *mp;
	244	if (!*map)
	245	map_read(map);
	246
195254b8 N	247	for (mp = *map ; mp ; mp = mp->next) {
	248	if (memcmp(uuid, mp->uuid, 16) != 0)
	249	continue;
	250	if (!mddev_busy(mp->devnum)) {
	251	mp->bad = 1;
	252	continue;
	253	}
	254	return mp;
	255	}
8382f19b	256	return NULL;
4ccad7b1	257	}
8382f19b	258
4ccad7b1 N	259	struct map_ent map_by_devnum(struct map_ent *map, int devnum)
	260	{
	261	struct map_ent *mp;
	262	if (!*map)
	263	map_read(map);
	264
195254b8 N	265	for (mp = *map ; mp ; mp = mp->next) {
	266	if (mp->devnum != devnum)
	267	continue;
	268	if (!mddev_busy(mp->devnum)) {
	269	mp->bad = 1;
	270	continue;
	271	}
	272	return mp;
	273	}
4ccad7b1	274	return NULL;
8382f19b	275	}
f2e55ecc N	276
	277	struct map_ent map_by_name(struct map_ent map, char name)
	278	{
	279	struct map_ent *mp;
	280	if (!*map)
	281	map_read(map);
	282
	283	for (mp = *map ; mp ; mp = mp->next) {
8615dcff N	284	if (!mp->path)
8615dcff N	285	continue;
f2e55ecc N	286	if (strncmp(mp->path, "/dev/md/", 8) != 0)
f2e55ecc N	287	continue;
195254b8 N	288	if (strcmp(mp->path+8, name) != 0)
	289	continue;
	290	if (!mddev_busy(mp->devnum)) {
	291	mp->bad = 1;
	292	continue;
	293	}
	294	return mp;
f2e55ecc N	295	}
	296	return NULL;
	297	}
3a56f223 N	298
	299	void RebuildMap(void)
	300	{
	301	struct mdstat_ent *mdstat = mdstat_read(0, 0);
	302	struct mdstat_ent *md;
	303	struct map_ent *map = NULL;
	304	int mdp = get_mdp_major();
	305
	306	for (md = mdstat ; md ; md = md->next) {
506ffd1e	307	struct mdinfo *sra = sysfs_read(-1, md->devnum, GET_DEVS\|SKIP_GONE_DEVS);
3a56f223 N	308	struct mdinfo *sd;
3a56f223 N	309
506ffd1e DW	310	if (!sra)
	311	continue;
	312
3a56f223 N	313	for (sd = sra->devs ; sd ; sd = sd->next) {
	314	char dn[30];
	315	int dfd;
	316	int ok;
	317	struct supertype *st;
	318	char *path;
	319	struct mdinfo info;
	320
	321	sprintf(dn, "%d:%d", sd->disk.major, sd->disk.minor);
	322	dfd = dev_open(dn, O_RDONLY);
	323	if (dfd < 0)
	324	continue;
	325	st = guess_super(dfd);
	326	if ( st == NULL)
	327	ok = -1;
	328	else
	329	ok = st->ss->load_super(st, dfd, NULL);
	330	close(dfd);
	331	if (ok != 0)
	332	continue;
	333	st->ss->getinfo_super(st, &info);
60f8cb9b	334	if (md->devnum >= 0)
3a56f223 N	335	path = map_dev(MD_MAJOR, md->devnum, 0);
	336	else
	337	path = map_dev(mdp, (-1-md->devnum)<< 6, 0);
8a659c33 N	338	map_add(&map, md->devnum,
8a659c33 N	339	info.text_version,
8615dcff	340	info.uuid, path);
3a56f223 N	341	st->ss->free_super(st);
	342	break;
	343	}
8a659c33	344	sysfs_free(sra);
3a56f223 N	345	}
	346	map_write(map);
	347	map_free(map);
8a659c33 N	348	for (md = mdstat ; md ; md = md->next) {
	349	struct mdinfo *sra = sysfs_read(-1, md->devnum, GET_VERSION);
	350	sysfs_uevent(sra, "change");
	351	sysfs_free(sra);
	352	}
78fbcc10	353	free_mdstat(mdstat);
3a56f223	354	}