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+/*
+ * mapfile - keep track of uuid <-> array mapping. Part of:
+ * mdadm - manage Linux "md" devices aka RAID arrays.
+ *
+ * Copyright (C) 2006-2010 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
+ */
+
+/* The mapfile is used to track arrays being created in --incremental
+ * mode. 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 best place for the mapfile is /run/mdadm/map. Distros and users
+ * which have not switched to /run yet can choose a different location
+ * at compile time via MAP_DIR and MAP_FILE.
+ */
+#include "mdadm.h"
+#include <sys/file.h>
+#include <ctype.h>
+
+#define MAP_READ 0
+#define MAP_NEW 1
+#define MAP_LOCK 2
+#define MAP_DIRNAME 3
+
+char *mapname[4] = {
+ MAP_DIR "/" MAP_FILE,
+ MAP_DIR "/" MAP_FILE ".new",
+ MAP_DIR "/" MAP_FILE ".lock",
+ MAP_DIR
+};
+
+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 fd;
+ if ((mapmode[modenum] & O_CREAT))
+ /* Attempt to create directory, don't worry about
+ * failure.
+ */
+ (void)mkdir(mapname[MAP_DIRNAME], 0755);
+ fd = open(mapname[modenum], mapmode[modenum], 0600);
+ if (fd >= 0)
+ return fdopen(fd, mapsmode[modenum]);
+ return NULL;
+}
+
+int map_write(struct map_ent *mel)
+{
+ FILE *f;
+ int err;
+
+ f = open_map(MAP_NEW);
+
+ if (!f)
+ return 0;
+ for (; mel; mel = mel->next) {
+ if (mel->bad)
+ continue;
+ fprintf(f, "%s ", mel->devnm);
+ 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[1]);
+ return 0;
+ }
+ return rename(mapname[1],
+ mapname[0]) == 0;
+}
+
+static FILE *lf = NULL;
+int map_lock(struct map_ent **melp)
+{
+ while (lf == NULL) {
+ struct stat buf;
+ lf = open_map(MAP_LOCK);
+ if (lf == NULL)
+ return -1;
+ if (flock(fileno(lf), LOCK_EX) != 0) {
+ fclose(lf);
+ lf = NULL;
+ return -1;
+ }
+ if (fstat(fileno(lf), &buf) != 0 ||
+ buf.st_nlink == 0) {
+ /* The owner of the lock unlinked it,
+ * so we have a lock on a stale file,
+ * try again
+ */
+ fclose(lf);
+ lf = NULL;
+ }
+ }
+ if (*melp)
+ map_free(*melp);
+ map_read(melp);
+ return 0;
+}
+
+void map_unlock(struct map_ent **melp)
+{
+ if (lf) {
+ /* must unlink before closing the file,
+ * as only the owner of the lock may
+ * unlink the file
+ */
+ unlink(mapname[2]);
+ fclose(lf);
+ }
+ if (*melp)
+ map_free(*melp);
+ lf = NULL;
+}
+
+void map_fork(void)
+{
+ /* We are forking, so must close the lock file.
+ * Don't risk flushing anything though.
+ */
+ if (lf) {
+ close(fileno(lf));
+ fclose(lf);
+ lf = NULL;
+ }
+}
+
+void map_add(struct map_ent **melp,
+ char * devnm, char *metadata, int uuid[4], char *path)
+{
+ struct map_ent *me = xmalloc(sizeof(*me));
+
+ strcpy(me->devnm, devnm);
+ strcpy(me->metadata, metadata);
+ memcpy(me->uuid, uuid, 16);
+ me->path = path ? xstrdup(path) : NULL;
+ me->next = *melp;
+ me->bad = 0;
+ *melp = me;
+}
+
+void map_read(struct map_ent **melp)
+{
+ FILE *f;
+ char buf[8192];
+ char path[201];
+ int uuid[4];
+ char devnm[32];
+ char metadata[30];
+
+ *melp = NULL;
+
+ f = open_map(MAP_READ);
+ if (!f) {
+ RebuildMap();
+ f = open_map(MAP_READ);
+ }
+ if (!f)
+ return;
+
+ while (fgets(buf, sizeof(buf), f)) {
+ path[0] = 0;
+ if (sscanf(buf, " %s %s %x:%x:%x:%x %200s",
+ devnm, metadata, uuid, uuid+1,
+ uuid+2, uuid+3, path) >= 7) {
+ map_add(melp, devnm, 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, char *devnm, char *metadata,
+ int uuid[4], 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 (strcmp(mp->devnm, devnm) == 0) {
+ strcpy(mp->metadata, metadata);
+ memcpy(mp->uuid, uuid, 16);
+ free(mp->path);
+ mp->path = path ? xstrdup(path) : NULL;
+ mp->bad = 0;
+ break;
+ }
+ if (!mp)
+ map_add(&map, devnm, metadata, uuid, path);
+ if (mpp)
+ *mpp = NULL;
+ rv = map_write(map);
+ map_free(map);
+ return rv;
+}
+
+void map_delete(struct map_ent **mapp, char *devnm)
+{
+ struct map_ent *mp;
+
+ if (*mapp == NULL)
+ map_read(mapp);
+
+ for (mp = *mapp; mp; mp = *mapp) {
+ if (strcmp(mp->devnm, devnm) == 0) {
+ *mapp = mp->next;
+ free(mp->path);
+ free(mp);
+ } else
+ mapp = & mp->next;
+ }
+}
+
+void map_remove(struct map_ent **mapp, char *devnm)
+{
+ if (devnm[0] == 0)
+ return;
+
+ map_delete(mapp, devnm);
+ map_write(*mapp);
+ map_free(*mapp);
+ *mapp = NULL;
+}
+
+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->devnm)) {
+ mp->bad = 1;
+ continue;
+ }
+ return mp;
+ }
+ return NULL;
+}
+
+struct map_ent *map_by_devnm(struct map_ent **map, char *devnm)
+{
+ struct map_ent *mp;
+ if (!*map)
+ map_read(map);
+
+ for (mp = *map ; mp ; mp = mp->next) {
+ if (strcmp(mp->devnm, devnm) != 0)
+ continue;
+ if (!mddev_busy(mp->devnm)) {
+ 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->devnm)) {
+ mp->bad = 1;
+ continue;
+ }
+ return mp;
+ }
+ return NULL;
+}
+
+/* sets the proper subarray and container_dev according to the metadata
+ * version super_by_fd does this automatically, this routine is meant as
+ * a supplement for guess_super()
+ */
+static char *get_member_info(struct mdstat_ent *ent)
+{
+
+ if (ent->metadata_version == NULL ||
+ strncmp(ent->metadata_version, "external:", 9) != 0)
+ return NULL;
+
+ if (is_subarray(&ent->metadata_version[9])) {
+ char *subarray;
+
+ subarray = strrchr(ent->metadata_version, '/');
+ return subarray + 1;
+ }
+ return NULL;
+}
+
+void RebuildMap(void)
+{
+ struct mdstat_ent *mdstat = mdstat_read(0, 0);
+ struct mdstat_ent *md;
+ struct map_ent *map = NULL;
+ int require_homehost;
+ char sys_hostname[256];
+ char *homehost = conf_get_homehost(&require_homehost);
+
+ if (homehost == NULL || strcmp(homehost, "<system>")==0) {
+ if (gethostname(sys_hostname, sizeof(sys_hostname)) == 0) {
+ sys_hostname[sizeof(sys_hostname)-1] = 0;
+ homehost = sys_hostname;
+ }
+ }
+
+ for (md = mdstat ; md ; md = md->next) {
+ struct mdinfo *sra = sysfs_read(-1, md->devnm, GET_DEVS);
+ struct mdinfo *sd;
+
+ if (!sra)
+ continue;
+
+ for (sd = sra->devs ; sd ; sd = sd->next) {
+ char namebuf[100];
+ char dn[30];
+ int dfd;
+ int ok;
+ dev_t devid;
+ struct supertype *st;
+ char *subarray = NULL;
+ 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 {
+ subarray = get_member_info(md);
+ ok = st->ss->load_super(st, dfd, NULL);
+ }
+ close(dfd);
+ if (ok != 0)
+ continue;
+ if (subarray)
+ info = st->ss->container_content(st, subarray);
+ else {
+ info = xmalloc(sizeof(*info));
+ st->ss->getinfo_super(st, info, NULL);
+ }
+ if (!info)
+ continue;
+
+ devid = devnm2devid(md->devnm);
+ path = map_dev(major(devid), minor(devid), 0);
+ if (path == NULL ||
+ strncmp(path, "/dev/md/", 8) != 0) {
+ /* We would really like a name that provides
+ * an MD_DEVNAME for udev.
+ * The name needs to be unique both in /dev/md/
+ * and in this mapfile.
+ * It needs to match what -I or -As would come
+ * up with.
+ * That means:
+ * Check if array is in mdadm.conf
+ * - if so use that.
+ * determine trustworthy from homehost etc
+ * find a unique name based on metadata name.
+ *
+ */
+ struct mddev_ident *match = conf_match(st, info,
+ NULL, 0,
+ NULL);
+ struct stat stb;
+ if (match && match->devname && match->devname[0] == '/') {
+ path = match->devname;
+ if (path[0] != '/') {
+ strcpy(namebuf, "/dev/md/");
+ strcat(namebuf, path);
+ path = namebuf;
+ }
+ } else {
+ int unum = 0;
+ char *sep = "_";
+ const char *name;
+ int conflict = 1;
+ if ((homehost == NULL ||
+ st->ss->match_home(st, homehost) != 1) &&
+ st->ss->match_home(st, "any") != 1 &&
+ (require_homehost ||
+ !conf_name_is_free(info->name)))
+ /* require a numeric suffix */
+ unum = 0;
+ else
+ /* allow name to be used as-is if no conflict */
+ unum = -1;
+ name = info->name;
+ if (!*name) {
+ name = st->ss->name;
+ if (!isdigit(name[strlen(name)-1]) &&
+ unum == -1) {
+ unum = 0;
+ sep = "";
+ }
+ }
+ if (strchr(name, ':')) {
+ /* Probably a uniquifying
+ * hostname prefix. Allow
+ * without a suffix, and strip
+ * hostname if it is us.
+ */
+ if (homehost && unum == -1 &&
+ strncmp(name, homehost,
+ strlen(homehost)) == 0 &&
+ name[strlen(homehost)] == ':')
+ name += strlen(homehost)+1;
+ unum = -1;
+ }
+
+ while (conflict) {
+ if (unum >= 0)
+ sprintf(namebuf, "/dev/md/%s%s%d",
+ name, sep, unum);
+ else
+ sprintf(namebuf, "/dev/md/%s",
+ name);
+ unum++;
+ if (lstat(namebuf, &stb) != 0 &&
+ (map == NULL ||
+ !map_by_name(&map, namebuf+8)))
+ conflict = 0;
+ }
+ path = namebuf;
+ }
+ }
+ map_add(&map, md->devnm,
+ info->text_version,
+ info->uuid, path);
+ st->ss->free_super(st);
+ free(info);
+ break;
+ }
+ sysfs_free(sra);
+ }
+ /* Only trigger a change if we wrote a new map file */
+ if (map_write(map))
+ for (md = mdstat ; md ; md = md->next) {
+ struct mdinfo *sra = sysfs_read(-1, md->devnm,
+ GET_VERSION);
+ if (sra)
+ sysfs_uevent(sra, "change");
+ sysfs_free(sra);
+ }
+ map_free(map);
+ free_mdstat(mdstat);
+}