diff options
Diffstat (limited to 'lib.c')
| -rw-r--r-- | lib.c | 575 |
1 files changed, 575 insertions, 0 deletions
@@ -0,0 +1,575 @@ +/* + * mdadm - manage Linux "md" devices aka RAID arrays. + * + * Copyright (C) 2011 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> + */ + +#include "mdadm.h" +#include "dlink.h" +#include <ctype.h> +#include <limits.h> + +bool is_dev_alive(char *path) +{ + if (!path) + return false; + + if (access(path, R_OK) == 0) + return true; + + return false; +} + +/* This fill contains various 'library' style function. They + * have no dependency on anything outside this file. + */ + +int get_mdp_major(void) +{ + static int mdp_major = -1; + FILE *fl; + char *w; + int have_block = 0; + int have_devices = 0; + int last_num = -1; + + if (mdp_major != -1) + return mdp_major; + + fl = fopen("/proc/devices", "r"); + if (!fl) + return -1; + + while ((w = conf_word(fl, 1))) { + if (have_block && strcmp(w, "devices:") == 0) + have_devices = 1; + have_block = (strcmp(w, "Block") == 0); + if (isdigit(w[0])) + last_num = atoi(w); + if (have_devices && strcmp(w, "mdp") == 0) + mdp_major = last_num; + free(w); + } + fclose(fl); + + return mdp_major; +} + +char *devid2kname(dev_t devid) +{ + char path[30]; + char link[PATH_MAX]; + static char devnm[32]; + char *cp; + int n; + + /* Look at the + * /sys/dev/block/%d:%d link which must look like + * and take the last component. + */ + sprintf(path, "/sys/dev/block/%d:%d", major(devid), minor(devid)); + n = readlink(path, link, sizeof(link) - 1); + if (n > 0) { + link[n] = 0; + cp = strrchr(link, '/'); + if (cp) { + strcpy(devnm, cp + 1); + return devnm; + } + } + return NULL; +} + +char *stat2kname(struct stat *st) +{ + if ((S_IFMT & st->st_mode) != S_IFBLK) + return NULL; + + return devid2kname(st->st_rdev); +} + +char *fd2kname(int fd) +{ + struct stat stb; + + if (fstat(fd, &stb) == 0) + return stat2kname(&stb); + + return NULL; +} + +char *devid2devnm(dev_t devid) +{ + char path[30]; + char link[200]; + static char devnm[32]; + char *cp, *ep; + int n; + + /* Might be an extended-minor partition or a + * named md device. Look at the + * /sys/dev/block/%d:%d link which must look like + * ../../block/mdXXX/mdXXXpYY + * or + * ...../block/md_FOO + */ + sprintf(path, "/sys/dev/block/%d:%d", major(devid), minor(devid)); + n = readlink(path, link, sizeof(link) - 1); + if (n > 0) { + link[n] = 0; + cp = strstr(link, "/block/"); + if (cp) { + cp += 7; + ep = strchr(cp, '/'); + if (ep) + *ep = 0; + strcpy(devnm, cp); + return devnm; + } + } + if (major(devid) == MD_MAJOR) + sprintf(devnm,"md%d", minor(devid)); + else if (major(devid) == (unsigned)get_mdp_major()) + sprintf(devnm,"md_d%d", + (minor(devid)>>MdpMinorShift)); + else + return NULL; + + return devnm; +} + +char *stat2devnm(struct stat *st) +{ + if ((S_IFMT & st->st_mode) != S_IFBLK) + return NULL; + + return devid2devnm(st->st_rdev); +} + +char *fd2devnm(int fd) +{ + struct stat stb; + + if (fstat(fd, &stb) == 0) + return stat2devnm(&stb); + + return NULL; +} + +/* When we create a new array, we don't want the content to + * be immediately examined by udev - it is probably meaningless. + * So create /run/mdadm/creating-mdXXX and expect that a udev + * rule will noticed this and act accordingly. + */ +static char block_path[] = "/run/mdadm/creating-%s"; +static char *unblock_path = NULL; +void udev_block(char *devnm) +{ + int fd; + char *path = NULL; + + xasprintf(&path, block_path, devnm); + fd = open(path, O_CREAT|O_RDWR, 0600); + if (fd >= 0) { + close(fd); + unblock_path = path; + } else + free(path); +} + +void udev_unblock(void) +{ + if (unblock_path) + unlink(unblock_path); + free(unblock_path); + unblock_path = NULL; +} + +/* + * convert a major/minor pair for a block device into a name in /dev, if possible. + * On the first call, walk /dev collecting name. + * Put them in a simple linked listfor now. + */ +struct devmap { + int major, minor; + char *name; + struct devmap *next; +} *devlist = NULL; +int devlist_ready = 0; + +int add_dev(const char *name, const struct stat *stb, int flag, struct FTW *s) +{ + struct stat st; + + if (S_ISLNK(stb->st_mode)) { + if (stat(name, &st) != 0) + return 0; + stb = &st; + } + + if ((stb->st_mode&S_IFMT)== S_IFBLK) { + char *n = xstrdup(name); + struct devmap *dm = xmalloc(sizeof(*dm)); + if (strncmp(n, "/dev/./", 7) == 0) + strcpy(n + 4, name + 6); + if (dm) { + dm->major = major(stb->st_rdev); + dm->minor = minor(stb->st_rdev); + dm->name = n; + dm->next = devlist; + devlist = dm; + } + } + + return 0; +} + +#ifndef HAVE_NFTW +#ifdef HAVE_FTW +int add_dev_1(const char *name, const struct stat *stb, int flag) +{ + return add_dev(name, stb, flag, NULL); +} +int nftw(const char *path, + int (*han)(const char *name, const struct stat *stb, + int flag, struct FTW *s), int nopenfd, int flags) +{ + return ftw(path, add_dev_1, nopenfd); +} +#else +int nftw(const char *path, + int (*han)(const char *name, const struct stat *stb, + int flag, struct FTW *s), int nopenfd, int flags) +{ + return 0; +} +#endif /* HAVE_FTW */ +#endif /* HAVE_NFTW */ + +/* + * Find a block device with the right major/minor number. + * If we find multiple names, choose the shortest. + * If we find a name in /dev/md/, we prefer that. + * This applies only to names for MD devices. + * If 'prefer' is set (normally to e.g. /by-path/) + * then we prefer a name which contains that string. + */ +char *map_dev_preferred(int major, int minor, int create, + char *prefer) +{ + struct devmap *p; + char *regular = NULL, *preferred=NULL; + int did_check = 0; + + if (major == 0 && minor == 0) + return NULL; + + retry: + if (!devlist_ready) { + char *dev = "/dev"; + struct stat stb; + while(devlist) { + struct devmap *d = devlist; + devlist = d->next; + free(d->name); + free(d); + } + if (lstat(dev, &stb) == 0 && S_ISLNK(stb.st_mode)) + dev = "/dev/."; + nftw(dev, add_dev, 10, FTW_PHYS); + devlist_ready=1; + did_check = 1; + } + + for (p = devlist; p; p = p->next) + if (p->major == major && p->minor == minor) { + if (strncmp(p->name, "/dev/md/",8) == 0 || + (prefer && strstr(p->name, prefer))) { + if (preferred == NULL || + strlen(p->name) < strlen(preferred)) + preferred = p->name; + } else { + if (regular == NULL || + strlen(p->name) < strlen(regular)) + regular = p->name; + } + } + if (!regular && !preferred && !did_check) { + devlist_ready = 0; + goto retry; + } + if (create && !regular && !preferred) { + static char buf[30]; + snprintf(buf, sizeof(buf), "%d:%d", major, minor); + regular = buf; + } + + return preferred ? preferred : regular; +} + +/* conf_word gets one word from the conf file. + * if "allow_key", then accept words at the start of a line, + * otherwise stop when such a word is found. + * We assume that the file pointer is at the end of a word, so the + * next character is a space, or a newline. If not, it is the start of a line. + */ + +char *conf_word(FILE *file, int allow_key) +{ + int wsize = 100; + int len = 0; + int c; + int quote; + int wordfound = 0; + char *word = xmalloc(wsize); + + while (wordfound == 0) { + /* at the end of a word.. */ + c = getc(file); + if (c == '#') + while (c != EOF && c != '\n') + c = getc(file); + if (c == EOF) + break; + if (c == '\n') + continue; + + if (c != ' ' && c != '\t' && ! allow_key) { + ungetc(c, file); + break; + } + /* looks like it is safe to get a word here, if there is one */ + quote = 0; + /* first, skip any spaces */ + while (c == ' ' || c == '\t') + c = getc(file); + if (c != EOF && c != '\n' && c != '#') { + /* we really have a character of a word, so start saving it */ + while (c != EOF && c != '\n' && + (quote || (c != ' ' && c != '\t'))) { + wordfound = 1; + if (quote && c == quote) + quote = 0; + else if (quote == 0 && (c == '\'' || c == '"')) + quote = c; + else { + if (len == wsize-1) { + wsize += 100; + word = xrealloc(word, wsize); + } + word[len++] = c; + } + c = getc(file); + /* Hack for broken kernels (2.6.14-.24) that put + * "active(auto-read-only)" + * in /proc/mdstat instead of + * "active (auto-read-only)" + */ + if (c == '(' && len >= 6 && + strncmp(word + len - 6, "active", 6) == 0) + c = ' '; + } + } + if (c != EOF) + ungetc(c, file); + } + word[len] = 0; + + /* Further HACK for broken kernels.. 2.6.14-2.6.24 */ + if (strcmp(word, "auto-read-only)") == 0) + strcpy(word, "(auto-read-only)"); + +/* printf("word is <%s>\n", word); */ + if (!wordfound) { + free(word); + word = NULL; + } + return word; +} + +void print_quoted(char *str) +{ + /* Printf the string with surrounding quotes + * iff needed. + * If no space, tab, or quote - leave unchanged. + * Else print surrounded by " or ', swapping quotes + * when we find one that will cause confusion. + */ + + char first_quote = 0, q; + char *c; + + for (c = str; *c; c++) { + switch(*c) { + case '\'': + case '"': + first_quote = *c; + break; + case ' ': + case '\t': + first_quote = *c; + continue; + default: + continue; + } + break; + } + if (!first_quote) { + printf("%s", str); + return; + } + + if (first_quote == '"') + q = '\''; + else + q = '"'; + putchar(q); + for (c = str; *c; c++) { + if (*c == q) { + putchar(q); + q ^= '"' ^ '\''; + putchar(q); + } + putchar(*c); + } + putchar(q); +} + +void print_escape(char *str) +{ + /* print str, but change space and tab to '_' + * as is suitable for device names + */ + for (; *str; str++) { + switch (*str) { + case ' ': + case '\t': + putchar('_'); + break; + case '/': + putchar('-'); + break; + default: + putchar(*str); + } + } +} + +int check_env(char *name) +{ + char *val = getenv(name); + + if (val && atoi(val) == 1) + return 1; + + return 0; +} + +int use_udev(void) +{ + static int use = -1; + struct stat stb; + + if (use < 0) { + use = ((stat("/dev/.udev", &stb) == 0 || + stat("/run/udev", &stb) == 0) && + check_env("MDADM_NO_UDEV") == 0); + } + return use; +} + +unsigned long GCD(unsigned long a, unsigned long b) +{ + while (a != b) { + if (a < b) + b -= a; + if (b < a) + a -= b; + } + return a; +} + +/* + * conf_line reads one logical line from the conffile or mdstat. + * It skips comments and continues until it finds a line that starts + * with a non blank/comment. This character is pushed back for the next call + * A doubly linked list of words is returned. + * the first word will be a keyword. Other words will have had quotes removed. + */ + +char *conf_line(FILE *file) +{ + char *w; + char *list; + + w = conf_word(file, 1); + if (w == NULL) + return NULL; + + list = dl_strdup(w); + free(w); + dl_init(list); + + while ((w = conf_word(file, 0))){ + char *w2 = dl_strdup(w); + free(w); + dl_add(list, w2); + } +/* printf("got a line\n");*/ + return list; +} + +void free_line(char *line) +{ + char *w; + for (w = dl_next(line); w != line; w = dl_next(line)) { + dl_del(w); + dl_free(w); + } + dl_free(line); +} + +/** + * parse_num() - Parse int from string. + * @dest: Pointer to destination. + * @num: Pointer to string that is going to be parsed. + * + * If string contains anything after a number, error code is returned. + * The same happens when number is bigger than INT_MAX or smaller than 0. + * Writes to destination only if successfully read the number. + * + * Return: 0 on success, 1 otherwise. + */ +int parse_num(int *dest, char *num) +{ + char *c = NULL; + long temp; + + if (!num) + return 1; + + errno = 0; + temp = strtol(num, &c, 10); + if (temp < 0 || temp > INT_MAX || *c || errno != 0 || num == c) + return 1; + *dest = temp; + return 0; +} |