2 * mdadm - manage Linux "md" devices aka RAID arrays.
4 * Copyright (C) 2011 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 /* This fill contains various 'library' style function. They
30 * have no dependency on anything outside this file.
33 int get_mdp_major(void)
35 static int mdp_major = -1;
44 fl = fopen("/proc/devices", "r");
47 while ((w = conf_word(fl, 1))) {
48 if (have_block && strcmp(w, "devices:")==0)
50 have_block = (strcmp(w, "Block")==0);
53 if (have_devices && strcmp(w, "mdp")==0)
61 char *devid2kname(int devid)
65 static char devnm[32];
70 * /sys/dev/block/%d:%d link which must look like
71 * and take the last component.
73 sprintf(path, "/sys/dev/block/%d:%d", major(devid),
75 n = readlink(path, link, sizeof(link)-1);
78 cp = strrchr(link, '/');
87 char *stat2kname(struct stat *st)
89 if ((S_IFMT & st->st_mode) != S_IFBLK)
91 return devid2kname(st->st_rdev);
94 char *fd2kname(int fd)
97 if (fstat(fd, &stb) == 0)
98 return stat2kname(&stb);
102 char *devid2devnm(int devid)
106 static char devnm[32];
110 /* Might be an extended-minor partition or a
111 * named md device. Look at the
112 * /sys/dev/block/%d:%d link which must look like
113 * ../../block/mdXXX/mdXXXpYY
117 sprintf(path, "/sys/dev/block/%d:%d", major(devid),
119 n = readlink(path, link, sizeof(link)-1);
122 cp = strstr(link, "/block/");
125 ep = strchr(cp, '/');
132 if (major(devid) == MD_MAJOR)
133 sprintf(devnm,"md%d", minor(devid));
134 else if (major(devid) == (unsigned)get_mdp_major())
135 sprintf(devnm,"md_d%d",
136 (minor(devid)>>MdpMinorShift));
142 char *stat2devnm(struct stat *st)
144 if ((S_IFMT & st->st_mode) != S_IFBLK)
146 return devid2devnm(st->st_rdev);
149 char *fd2devnm(int fd)
152 if (fstat(fd, &stb) == 0)
153 return stat2devnm(&stb);
158 * convert a major/minor pair for a block device into a name in /dev, if possible.
159 * On the first call, walk /dev collecting name.
160 * Put them in a simple linked listfor now.
167 int devlist_ready = 0;
169 int add_dev(const char *name, const struct stat *stb, int flag, struct FTW *s)
173 if (S_ISLNK(stb->st_mode)) {
174 if (stat(name, &st) != 0)
179 if ((stb->st_mode&S_IFMT)== S_IFBLK) {
180 char *n = xstrdup(name);
181 struct devmap *dm = xmalloc(sizeof(*dm));
182 if (strncmp(n, "/dev/./", 7)==0)
185 dm->major = major(stb->st_rdev);
186 dm->minor = minor(stb->st_rdev);
197 int add_dev_1(const char *name, const struct stat *stb, int flag)
199 return add_dev(name, stb, flag, NULL);
201 int nftw(const char *path, int (*han)(const char *name, const struct stat *stb, int flag, struct FTW *s), int nopenfd, int flags)
203 return ftw(path, add_dev_1, nopenfd);
206 int nftw(const char *path, int (*han)(const char *name, const struct stat *stb, int flag, struct FTW *s), int nopenfd, int flags)
210 #endif /* HAVE_FTW */
211 #endif /* HAVE_NFTW */
214 * Find a block device with the right major/minor number.
215 * If we find multiple names, choose the shortest.
216 * If we find a name in /dev/md/, we prefer that.
217 * This applies only to names for MD devices.
218 * If 'prefer' is set (normally to e.g. /by-path/)
219 * then we prefer a name which contains that string.
221 char *map_dev_preferred(int major, int minor, int create,
225 char *regular = NULL, *preferred=NULL;
228 if (major == 0 && minor == 0)
232 if (!devlist_ready) {
236 struct devmap *d = devlist;
241 if (lstat(dev, &stb)==0 &&
242 S_ISLNK(stb.st_mode))
244 nftw(dev, add_dev, 10, FTW_PHYS);
249 for (p=devlist; p; p=p->next)
250 if (p->major == major &&
252 if (strncmp(p->name, "/dev/md/",8) == 0
253 || (prefer && strstr(p->name, prefer))) {
254 if (preferred == NULL ||
255 strlen(p->name) < strlen(preferred))
258 if (regular == NULL ||
259 strlen(p->name) < strlen(regular))
263 if (!regular && !preferred && !did_check) {
267 if (create && !regular && !preferred) {
269 snprintf(buf, sizeof(buf), "%d:%d", major, minor);
273 return preferred ? preferred : regular;
276 /* conf_word gets one word from the conf file.
277 * if "allow_key", then accept words at the start of a line,
278 * otherwise stop when such a word is found.
279 * We assume that the file pointer is at the end of a word, so the
280 * next character is a space, or a newline. If not, it is the start of a line.
283 char *conf_word(FILE *file, int allow_key)
290 char *word = xmalloc(wsize);
292 while (wordfound==0) {
293 /* at the end of a word.. */
296 while (c != EOF && c != '\n')
299 if (c == '\n') continue;
301 if (c != ' ' && c != '\t' && ! allow_key) {
305 /* looks like it is safe to get a word here, if there is one */
307 /* first, skip any spaces */
308 while (c == ' ' || c == '\t')
310 if (c != EOF && c != '\n' && c != '#') {
311 /* we really have a character of a word, so start saving it */
312 while (c != EOF && c != '\n' && (quote || (c!=' ' && c != '\t'))) {
314 if (quote && c == quote) quote = 0;
315 else if (quote == 0 && (c == '\'' || c == '"'))
318 if (len == wsize-1) {
320 word = xrealloc(word, wsize);
325 /* Hack for broken kernels (2.6.14-.24) that put
326 * "active(auto-read-only)"
327 * in /proc/mdstat instead of
328 * "active (auto-read-only)"
330 if (c == '(' && len >= 6
331 && strncmp(word+len-6, "active", 6) == 0)
335 if (c != EOF) ungetc(c, file);
339 /* Further HACK for broken kernels.. 2.6.14-2.6.24 */
340 if (strcmp(word, "auto-read-only)") == 0)
341 strcpy(word, "(auto-read-only)");
343 /* printf("word is <%s>\n", word); */
351 void print_quoted(char *str)
353 /* Printf the string with surrounding quotes
355 * If no space, tab, or quote - leave unchanged.
356 * Else print surrounded by " or ', swapping quotes
357 * when we find one that will cause confusion.
360 char first_quote = 0, q;
363 for (c = str; *c; c++) {
383 if (first_quote == '"')
388 for (c = str; *c; c++) {
399 void print_escape(char *str)
401 /* print str, but change space and tab to '_'
402 * as is suitable for device names
404 for (; *str ; str++) {
419 int check_env(char *name)
421 char *val = getenv(name);
423 if (val && atoi(val) == 1)
435 use = ((stat("/dev/.udev", &stb) == 0
436 || stat("/run/udev", &stb) == 0)
437 && check_env("MDADM_NO_UDEV") == 0);
442 unsigned long GCD(unsigned long a, unsigned long b)
454 * conf_line reads one logical line from the conffile or mdstat.
455 * It skips comments and continues until it finds a line that starts
456 * with a non blank/comment. This character is pushed back for the next call
457 * A doubly linked list of words is returned.
458 * the first word will be a keyword. Other words will have had quotes removed.
461 char *conf_line(FILE *file)
466 w = conf_word(file, 1);
467 if (w == NULL) return NULL;
473 while ((w = conf_word(file,0))){
474 char *w2 = dl_strdup(w);
478 /* printf("got a line\n");*/
482 void free_line(char *line)
485 for (w=dl_next(line); w != line; w=dl_next(line)) {