2 * mdadm - manage Linux "md" devices aka RAID arrays.
4 * Copyright (C) 2001-2013 Neil Brown <neilb@suse.de>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 * Email: <neilb@suse.de>
29 void make_parts(char *dev, int cnt)
31 /* make 'cnt' partition devices for 'dev'
32 * If dev is a device name we use the
33 * major/minor from dev and add 1..cnt
34 * If it is a symlink, we make similar symlinks.
35 * If dev ends with a digit, we add "p%d" else "%d"
36 * If the name exists, we use it's owner/mode,
44 int nlen = strlen(dev) + 20;
46 int dig = isdigit(dev[strlen(dev)-1]);
53 if (lstat(dev, &stb)!= 0)
56 if (S_ISBLK(stb.st_mode)) {
57 major_num = major(stb.st_rdev);
58 minor_num = minor(stb.st_rdev);
60 } else if (S_ISLNK(stb.st_mode)) {
61 int len = readlink(dev, orig, sizeof(orig));
62 if (len < 0 || len > 1000)
65 odig = isdigit(orig[len-1]);
71 for (i = 1; i <= cnt ; i++) {
73 snprintf(name, nlen, "%s%s%d", dev, dig?"p":"", i);
74 if (stat(name, &stb2) == 0) {
75 if (!S_ISBLK(stb2.st_mode) || !S_ISBLK(stb.st_mode))
77 if (stb2.st_rdev == makedev(major_num, minor_num+i))
83 if (S_ISBLK(stb.st_mode)) {
84 if (mknod(name, S_IFBLK | 0600,
85 makedev(major_num, minor_num+i)))
87 if (chown(name, stb2.st_uid, stb2.st_gid))
89 if (chmod(name, stb2.st_mode & 07777))
93 snprintf(sym, sizeof(sym), "%s%s%d", orig, odig?"p":"", i);
94 err = symlink(sym, name);
97 if (err == 0 && stat(name, &stb2) == 0)
98 add_dev(name, &stb2, 0, NULL);
104 * We need a new md device to assemble/build/create an array.
105 * 'dev' is a name given us by the user (command line or mdadm.conf)
106 * It might start with /dev or /dev/md any might end with a digit
108 * If it starts with just /dev, it must be /dev/mdX or /dev/md_dX
109 * If it ends with a digit string, then it must be as above, or
110 * 'trustworthy' must be 'METADATA' and the 'dev' must be
111 * /dev/md/'name'NN or 'name'NN
112 * If it doesn't end with a digit string, it must be /dev/md/'name'
113 * or 'name' or must be NULL.
114 * If the digit string is present, it gives the minor number to use
115 * If not, we choose a high, unused minor number.
116 * If the 'dev' is a standard name, it devices whether 'md' or 'mdp'.
117 * else if the name is 'd[0-9]+' then we use mdp
118 * else if trustworthy is 'METADATA' we use md
119 * else the choice depends on 'autof'.
120 * If name is NULL it is assumed to match whatever dev provides.
121 * If both name and dev are NULL, we choose a name 'mdXX' or 'mdpXX'
123 * If 'name' is given, and 'trustworthy' is 'foreign' and name is not
124 * supported by 'dev', we add a "_%d" suffix based on the minor number
127 * If udev is configured, we create a temporary device, open it, and
129 * If not, we create the /dev/mdXX device, and if name is usable,
131 * In any case we return /dev/md/name or (if that isn't available)
132 * /dev/mdXX in 'chosen'.
134 * When we create devices, we use uid/gid/umask from config file.
137 int create_mddev(char *dev, char *name, int autof, int trustworthy,
144 struct createinfo *ci = conf_get_create_info();
159 strcpy(chosen, "/dev/md/");
160 cname = chosen + strlen(chosen);
163 if (strncmp(dev, "/dev/md/", 8) == 0) {
164 strcpy(cname, dev+8);
165 } else if (strncmp(dev, "/dev/", 5) == 0) {
166 char *e = dev + strlen(dev);
167 while (e > dev && isdigit(e[-1]))
170 num = strtoul(e, NULL, 10);
171 strcpy(cname, dev+5);
172 cname[e-(dev+5)] = 0;
173 /* name *must* be mdXX or md_dXX in this context */
175 (strcmp(cname, "md") != 0 && strcmp(cname, "md_d") != 0)) {
176 pr_err("%s is an invalid name for an md device. Try /dev/md/%s\n",
180 if (strcmp(cname, "md") == 0)
184 /* recreate name: /dev/md/0 or /dev/md/d0 */
185 sprintf(cname, "%s%d", use_mdp?"d":"", num);
189 /* 'cname' must not contain a slash, and may not be
192 if (strchr(cname, '/') != NULL) {
193 pr_err("%s is an invalid name for an md device.\n", dev);
197 pr_err("%s is an invalid name for an md device (empty!).", dev);
201 /* If cname is 'N' or 'dN', we get dev number
209 num = strtoul(sp, &ep, 10);
212 if (ep == sp || *ep || num < 0)
214 else if (cname[0] == 'd')
221 /* Now determine device number */
222 /* named 'METADATA' cannot use 'mdp'. */
223 if (name && name[0] == 0)
225 if (name && trustworthy == METADATA && use_mdp == 1) {
226 pr_err("%s is not allowed for a %s container. Consider /dev/md%d.\n", dev, name, num);
229 if (name && trustworthy == METADATA)
232 if (autof == 4 || autof == 6)
237 if (num < 0 && trustworthy == LOCAL && name) {
238 /* if name is numeric, possibly prefixed by
239 * 'md' or '/dev/md', use that for num
240 * if it is not already in use */
243 if (strncmp(n2, "/dev/", 5) == 0)
245 if (strncmp(n2, "md", 2) == 0)
249 num = strtoul(n2, &ep, 10);
253 sprintf(devnm, "md%s%d", use_mdp ? "_d":"", num);
254 if (mddev_busy(devnm))
259 if (cname[0] == 0 && name) {
260 /* Need to find a name if we can
261 * We don't completely trust 'name'. Truncate to
262 * reasonable length and remove '/'
265 struct map_ent *map = NULL;
269 strncpy(cname, name, 200);
271 for (cp = cname; *cp ; cp++)
282 if (trustworthy == LOCAL ||
283 (trustworthy == FOREIGN && strchr(cname, ':') != NULL)) {
284 /* Only need suffix if there is a conflict */
285 if (map_by_name(&map, cname) == NULL)
288 cnlen = strlen(cname);
290 if (trustworthy == METADATA && !isdigit(cname[cnlen-1]))
291 sprintf(cname+cnlen, "%d", unum);
293 /* add _%d to FOREIGN array that don't
296 sprintf(cname+cnlen, "_%d", unum);
298 if (map_by_name(&map, cname) == NULL)
304 if (num < 0 && cname && ci->names) {
307 sprintf(devnm, "md_%s", cname);
308 fd = open("/sys/module/md_mod/parameters/new_array", O_WRONLY);
310 n = write(fd, devnm, strlen(devnm));
319 /* need to choose a free number. */
320 char *_devnm = find_free_devnm(use_mdp);
321 if (_devnm == NULL) {
322 pr_err("No avail md devices - aborting\n");
325 strcpy(devnm, _devnm);
327 sprintf(devnm, "%s%d", use_mdp?"md_d":"md", num);
328 if (mddev_busy(devnm)) {
329 pr_err("%s is already in use.\n",
335 sprintf(devname, "/dev/%s", devnm);
337 if (dev && dev[0] == '/')
339 else if (cname[0] == 0)
340 strcpy(chosen, devname);
342 /* We have a device number and name.
343 * If we cannot detect udev, we need to make
344 * devices and links ourselves.
347 /* Make sure 'devname' exists and 'chosen' is a symlink to it */
348 if (lstat(devname, &stb) == 0) {
349 /* Must be the correct device, else error */
350 if ((stb.st_mode&S_IFMT) != S_IFBLK ||
351 stb.st_rdev != devnm2devid(devnm)) {
352 pr_err("%s exists but looks wrong, please fix\n",
357 if (mknod(devname, S_IFBLK|0600,
358 devnm2devid(devnm)) != 0) {
359 pr_err("failed to create %s\n",
363 if (chown(devname, ci->uid, ci->gid))
365 if (chmod(devname, ci->mode))
368 add_dev(devname, &stb, 0, NULL);
371 make_parts(devname, parts);
373 if (strcmp(chosen, devname) != 0) {
374 if (mkdir("/dev/md",0700) == 0) {
375 if (chown("/dev/md", ci->uid, ci->gid))
376 perror("chown /dev/md");
377 if (chmod("/dev/md", ci->mode| ((ci->mode>>2) & 0111)))
378 perror("chmod /dev/md");
381 if (dev && strcmp(chosen, dev) == 0)
382 /* We know we are allowed to use this name */
385 if (lstat(chosen, &stb) == 0) {
387 ssize_t link_len = readlink(chosen, buf, sizeof(buf)-1);
389 buf[link_len] = '\0';
391 if ((stb.st_mode & S_IFMT) != S_IFLNK ||
393 strcmp(buf, devname) != 0) {
394 pr_err("%s exists - ignoring\n",
396 strcpy(chosen, devname);
398 } else if (symlink(devname, chosen) != 0)
399 pr_err("failed to create %s: %s\n",
400 chosen, strerror(errno));
401 if (use_mdp && strcmp(chosen, devname) != 0)
402 make_parts(chosen, parts);
405 mdfd = open_dev_excl(devnm);
407 pr_err("unexpected failure opening %s\n",
412 /* Open this and check that it is an md device.
413 * On success, return filedescriptor.
414 * On failure, return -1 if it doesn't exist,
415 * or -2 if it exists but is not an md device.
417 int open_mddev(char *dev, int report_errors)
419 int mdfd = open(dev, O_RDONLY);
422 pr_err("error opening %s: %s\n",
423 dev, strerror(errno));
426 if (md_get_version(mdfd) <= 0) {
429 pr_err("%s does not appear to be an md device\n", dev);
435 char *find_free_devnm(int use_partitions)
437 static char devnm[32];
439 for (devnum = 127; devnum != 128;
440 devnum = devnum ? devnum-1 : (1<<9)-1) {
443 sprintf(devnm, "md_d%d", devnum);
445 sprintf(devnm, "md%d", devnum);
446 if (mddev_busy(devnm))
448 if (!conf_name_is_free(devnm))
451 /* make sure it is new to /dev too, at least as a
453 dev_t devid = devnm2devid(devnm);
455 char *dn = map_dev(major(devid),
457 if (dn && ! is_standard(dn, NULL))