/* * mdadm - manage Linux "md" devices aka RAID arrays. * * Copyright (C) 2001-2013 Neil Brown * * * 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: */ #include "mdadm.h" #include "udev.h" #include "md_p.h" #include void make_parts(char *dev, int cnt) { /* make 'cnt' partition devices for 'dev' * If dev is a device name we use the * major/minor from dev and add 1..cnt * If it is a symlink, we make similar symlinks. * If dev ends with a digit, we add "p%d" else "%d" * If the name exists, we use it's owner/mode, * else that of dev */ struct stat stb; int major_num; int minor_num; int odig; int i; int nlen = strlen(dev) + 20; char *name; int dig = isdigit(dev[strlen(dev)-1]); char orig[1001]; char sym[1024]; int err; if (cnt == 0) cnt = 4; if (lstat(dev, &stb)!= 0) return; if (S_ISBLK(stb.st_mode)) { major_num = major(stb.st_rdev); minor_num = minor(stb.st_rdev); odig = -1; } else if (S_ISLNK(stb.st_mode)) { int len; len = readlink(dev, orig, sizeof(orig)); if (len < 0 || len >= (int)sizeof(orig)) return; orig[len] = 0; odig = isdigit(orig[len-1]); major_num = -1; minor_num = -1; } else return; name = xmalloc(nlen); for (i = 1; i <= cnt ; i++) { struct stat stb2; snprintf(name, nlen, "%s%s%d", dev, dig?"p":"", i); if (stat(name, &stb2) == 0) { if (!S_ISBLK(stb2.st_mode) || !S_ISBLK(stb.st_mode)) continue; if (stb2.st_rdev == makedev(major_num, minor_num+i)) continue; unlink(name); } else { stb2 = stb; } if (S_ISBLK(stb.st_mode)) { if (mknod(name, S_IFBLK | 0600, makedev(major_num, minor_num+i))) perror("mknod"); if (chown(name, stb2.st_uid, stb2.st_gid)) perror("chown"); if (chmod(name, stb2.st_mode & 07777)) perror("chmod"); err = 0; } else { snprintf(sym, sizeof(sym), "%s%s%d", orig, odig?"p":"", i); err = symlink(sym, name); } if (err == 0 && stat(name, &stb2) == 0) add_dev(name, &stb2, 0, NULL); } free(name); } int create_named_array(char *devnm) { int fd; int n = -1; static const char new_array_file[] = { "/sys/module/md_mod/parameters/new_array" }; fd = open(new_array_file, O_WRONLY); if (fd < 0 && errno == ENOENT) { if (system("modprobe md_mod") == 0) fd = open(new_array_file, O_WRONLY); } if (fd >= 0) { n = write(fd, devnm, strlen(devnm)); close(fd); } if (fd < 0 || n != (int)strlen(devnm)) { pr_err("Fail to create %s when using %s, fallback to creation via node\n", devnm, new_array_file); return 0; } return 1; } /* * We need a new md device to assemble/build/create an array. * 'dev' is a name given us by the user (command line or mdadm.conf) * It might start with /dev or /dev/md any might end with a digit * string. * If it starts with just /dev, it must be /dev/mdX or /dev/md_dX * If it ends with a digit string, then it must be as above, or * 'trustworthy' must be 'METADATA' and the 'dev' must be * /dev/md/'name'NN or 'name'NN * If it doesn't end with a digit string, it must be /dev/md/'name' * or 'name' or must be NULL. * If the digit string is present, it gives the minor number to use * If not, we choose a high, unused minor number. * If the 'dev' is a standard name, it devices whether 'md' or 'mdp'. * else if the name is 'd[0-9]+' then we use mdp * else if trustworthy is 'METADATA' we use md * else the choice depends on 'autof'. * If name is NULL it is assumed to match whatever dev provides. * If both name and dev are NULL, we choose a name 'mdXX' or 'mdpXX' * * If 'name' is given, and 'trustworthy' is 'foreign' and name is not * supported by 'dev', we add a "_%d" suffix based on the minor number * use that. * * If udev is configured, we create a temporary device, open it, and * unlink it. * If not, we create the /dev/mdXX device, and if name is usable, * /dev/md/name * In any case we return /dev/md/name or (if that isn't available) * /dev/mdXX in 'chosen'. * * When we create devices, we use uid/gid/umask from config file. */ int create_mddev(char *dev, char *name, int autof, int trustworthy, char *chosen, int block_udev) { int mdfd; struct stat stb; int num = -1; int use_mdp = -1; struct createinfo *ci = conf_get_create_info(); int parts; char *cname; char devname[37]; char devnm[32]; char cbuf[400]; if (!udev_is_available()) block_udev = 0; if (chosen == NULL) chosen = cbuf; if (autof == 0) autof = ci->autof; parts = autof >> 3; autof &= 7; strcpy(chosen, DEV_MD_DIR); cname = chosen + strlen(chosen); if (dev) { if (strncmp(dev, DEV_MD_DIR, DEV_MD_DIR_LEN) == 0) { snprintf(cname, MD_NAME_MAX, "%s", dev + DEV_MD_DIR_LEN); } else if (strncmp(dev, "/dev/", 5) == 0) { char *e = dev + strlen(dev); while (e > dev && isdigit(e[-1])) e--; if (e[0]) num = strtoul(e, NULL, 10); snprintf(cname, MD_NAME_MAX, "%s", dev + 5); cname[e-(dev+5)] = 0; /* name *must* be mdXX or md_dXX in this context */ if (num < 0 || (strcmp(cname, "md") != 0 && strcmp(cname, "md_d") != 0)) { pr_err("%s is an invalid name for an md device. Try /dev/md/%s\n", dev, dev+5); return -1; } if (strcmp(cname, "md") == 0) use_mdp = 0; else use_mdp = 1; /* recreate name: /dev/md/0 or /dev/md/d0 */ sprintf(cname, "%s%d", use_mdp?"d":"", num); } else strcpy(cname, dev); /* 'cname' must not contain a slash, and may not be * empty. */ if (strchr(cname, '/') != NULL) { pr_err("%s is an invalid name for an md device.\n", dev); return -1; } if (cname[0] == 0) { pr_err("%s is an invalid name for an md device (empty!).\n", dev); return -1; } if (num < 0) { /* If cname is 'N' or 'dN', we get dev number * from there. */ char *sp = cname; char *ep; if (cname[0] == 'd') sp++; if (isdigit(sp[0])) num = strtoul(sp, &ep, 10); else ep = sp; if (ep == sp || *ep || num < 0) num = -1; else if (cname[0] == 'd') use_mdp = 1; else use_mdp = 0; } } /* Now determine device number */ /* named 'METADATA' cannot use 'mdp'. */ if (name && name[0] == 0) name = NULL; if (name && trustworthy == METADATA && use_mdp == 1) { pr_err("%s is not allowed for a %s container. Consider /dev/md%d.\n", dev, name, num); return -1; } if (name && trustworthy == METADATA) use_mdp = 0; if (use_mdp == -1) { if (autof == 4 || autof == 6) use_mdp = 1; else use_mdp = 0; } if (num < 0 && trustworthy == LOCAL && name) { /* if name is numeric, possibly prefixed by * 'md' or '/dev/md', use that for num * if it is not already in use */ char *ep; char *n2 = name; if (strncmp(n2, "/dev/", 5) == 0) n2 += 5; if (strncmp(n2, "md", 2) == 0) n2 += 2; if (*n2 == '/') n2++; num = strtoul(n2, &ep, 10); if (ep == n2 || *ep) num = -1; else { sprintf(devnm, "md%s%d", use_mdp ? "_d":"", num); if (mddev_busy(devnm)) num = -1; } } if (cname[0] == 0 && name) { /* Need to find a name if we can * We don't completely trust 'name'. Truncate to * reasonable length and remove '/' */ char *cp; struct map_ent *map = NULL; int conflict = 1; int unum = 0; int cnlen; strncpy(cname, name, 200); cname[200] = 0; for (cp = cname; *cp ; cp++) switch (*cp) { case '/': *cp = '-'; break; case ' ': case '\t': *cp = '_'; break; } if (trustworthy == LOCAL || (trustworthy == FOREIGN && strchr(cname, ':') != NULL)) { /* Only need suffix if there is a conflict */ if (map_by_name(&map, cname) == NULL) conflict = 0; } cnlen = strlen(cname); while (conflict) { if (trustworthy == METADATA && !isdigit(cname[cnlen-1])) sprintf(cname+cnlen, "%d", unum); else /* add _%d to FOREIGN array that don't * a 'host:' prefix */ sprintf(cname+cnlen, "_%d", unum); unum++; if (map_by_name(&map, cname) == NULL) conflict = 0; } } devnm[0] = 0; if (num < 0 && cname && ci->names) { sprintf(devnm, "md_%s", cname); if (block_udev && udev_block(devnm) != UDEV_STATUS_SUCCESS) return -1; if (!create_named_array(devnm)) { devnm[0] = 0; udev_unblock(); } } if (num >= 0) { sprintf(devnm, "md%d", num); if (block_udev && udev_block(devnm) != UDEV_STATUS_SUCCESS) return -1; if (!create_named_array(devnm)) { devnm[0] = 0; udev_unblock(); } } if (devnm[0] == 0) { if (num < 0) { /* need to choose a free number. */ char *_devnm = find_free_devnm(use_mdp); if (_devnm == NULL) { pr_err("No avail md devices - aborting\n"); return -1; } strcpy(devnm, _devnm); } else { sprintf(devnm, "%s%d", use_mdp?"md_d":"md", num); if (mddev_busy(devnm)) { pr_err("%s is already in use.\n", dev); return -1; } } if (block_udev && udev_block(devnm) != UDEV_STATUS_SUCCESS) return -1; create_named_array(devnm); } sprintf(devname, "/dev/%s", devnm); if (dev && dev[0] == '/' && strlen(dev) < 400) strcpy(chosen, dev); else if (cname[0] == 0) strcpy(chosen, devname); /* We have a device number and name. * If we cannot detect udev, we need to make * devices and links ourselves. */ if (!udev_is_available()) { /* Make sure 'devname' exists and 'chosen' is a symlink to it */ if (lstat(devname, &stb) == 0) { /* Must be the correct device, else error */ if ((stb.st_mode&S_IFMT) != S_IFBLK || stb.st_rdev != devnm2devid(devnm)) { pr_err("%s exists but looks wrong, please fix\n", devname); return -1; } } else { if (mknod(devname, S_IFBLK|0600, devnm2devid(devnm)) != 0) { pr_err("failed to create %s\n", devname); return -1; } if (chown(devname, ci->uid, ci->gid)) perror("chown"); if (chmod(devname, ci->mode)) perror("chmod"); if (stat(devname, &stb) < 0) { pr_err("failed to stat %s\n", devname); return -1; } add_dev(devname, &stb, 0, NULL); } if (use_mdp == 1) make_parts(devname, parts); if (strcmp(chosen, devname) != 0) { if (mkdir(DEV_NUM_PREF, 0700) == 0) { if (chown(DEV_NUM_PREF, ci->uid, ci->gid)) perror("chown " DEV_NUM_PREF); if (chmod(DEV_NUM_PREF, ci->mode | ((ci->mode >> 2) & 0111))) perror("chmod " DEV_NUM_PREF); } if (dev && strcmp(chosen, dev) == 0) /* We know we are allowed to use this name */ unlink(chosen); if (lstat(chosen, &stb) == 0) { char buf[300]; ssize_t link_len = readlink(chosen, buf, sizeof(buf)-1); if (link_len >= 0) buf[link_len] = '\0'; if ((stb.st_mode & S_IFMT) != S_IFLNK || link_len < 0 || strcmp(buf, devname) != 0) { pr_err("%s exists - ignoring\n", chosen); strcpy(chosen, devname); } } else if (symlink(devname, chosen) != 0) pr_err("failed to create %s: %s\n", chosen, strerror(errno)); if (use_mdp && strcmp(chosen, devname) != 0) make_parts(chosen, parts); } } mdfd = open_dev_excl(devnm); if (mdfd < 0) pr_err("unexpected failure opening %s\n", devname); return mdfd; } /* Open this and check that it is an md device. * On success, return filedescriptor. * On failure, return -1 if it doesn't exist, * or -2 if it exists but is not an md device. */ int open_mddev(char *dev, int report_errors) { int mdfd = open(dev, O_RDONLY); if (mdfd < 0) { if (report_errors) pr_err("error opening %s: %s\n", dev, strerror(errno)); return -1; } if (md_array_valid(mdfd) == 0) { close(mdfd); if (report_errors) pr_err("%s does not appear to be an md device\n", dev); return -2; } return mdfd; } /** * is_mddev() - check that file name passed is an md device. * @dev: file name that has to be checked. * Return: 1 if file passed is an md device, 0 if not. */ int is_mddev(char *dev) { int fd = open_mddev(dev, 1); if (fd >= 0) { close(fd); return 1; } return 0; } char *find_free_devnm(int use_partitions) { static char devnm[32]; int devnum; for (devnum = 127; devnum != 128; devnum = devnum ? devnum-1 : (1<<9)-1) { if (use_partitions) sprintf(devnm, "md_d%d", devnum); else sprintf(devnm, "md%d", devnum); if (mddev_busy(devnm)) continue; if (!conf_name_is_free(devnm)) continue; if (!udev_is_available()) { /* make sure it is new to /dev too, at least as a * non-standard */ dev_t devid = devnm2devid(devnm); if (devid) { char *dn = map_dev(major(devid), minor(devid), 0); if (dn && ! is_standard(dn, NULL)) continue; } } break; } if (devnum == 128) return NULL; return devnm; }