/* * mdadm - manage Linux "md" devices aka RAID arrays. * * Copyright (C) 2011 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 /* 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; } void fmt_devname(char *name, int num) { if (num >= 0) sprintf(name, "md%d", num); else sprintf(name, "md_d%d", -1-num); } char *devnum2devname(int num) { char name[100]; fmt_devname(name,num); return strdup(name); } int devname2devnum(char *name) { char *ep; int num; if (strncmp(name, "md_d", 4)==0) num = -1-strtoul(name+4, &ep, 10); else num = strtoul(name+2, &ep, 10); return num; } int stat2devnum(struct stat *st) { char path[30]; char link[200]; char *cp; int n; if ((S_IFMT & st->st_mode) == S_IFBLK) { if (major(st->st_rdev) == MD_MAJOR) return minor(st->st_rdev); else if (major(st->st_rdev) == (unsigned)get_mdp_major()) return -1- (minor(st->st_rdev)>>MdpMinorShift); /* must be an extended-minor partition. Look at the * /sys/dev/block/%d:%d link which must look like * ../../block/mdXXX/mdXXXpYY */ sprintf(path, "/sys/dev/block/%d:%d", major(st->st_rdev), minor(st->st_rdev)); n = readlink(path, link, sizeof(link)-1); if (n <= 0) return NoMdDev; link[n] = 0; cp = strrchr(link, '/'); if (cp) *cp = 0; cp = strrchr(link, '/'); if (cp && strncmp(cp, "/md", 3) == 0) return devname2devnum(cp+1); } return NoMdDev; } int fd2devnum(int fd) { struct stat stb; if (fstat(fd, &stb) == 0) return stat2devnum(&stb); return NoMdDev; } /* * 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 = strdup(name); struct devmap *dm = malloc(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 = malloc(wsize); if (!word) abort(); 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 = realloc(word, wsize); if (!word) abort(); } 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); } } }