527 lines
13 KiB
C
527 lines
13 KiB
C
/*
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* mdadm - manage Linux "md" devices aka RAID arrays.
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*
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* Copyright (C) 2001-2013 Neil Brown <neilb@suse.de>
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*
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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* Author: Neil Brown
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* Email: <neilb@suse.de>
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*/
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#include "mdadm.h"
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#include "md_p.h"
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#include <ctype.h>
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void make_parts(char *dev, int cnt)
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{
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/* make 'cnt' partition devices for 'dev'
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* If dev is a device name we use the
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* major/minor from dev and add 1..cnt
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* If it is a symlink, we make similar symlinks.
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* If dev ends with a digit, we add "p%d" else "%d"
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* If the name exists, we use it's owner/mode,
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* else that of dev
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*/
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struct stat stb;
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int major_num;
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int minor_num;
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int odig;
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int i;
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int nlen = strlen(dev) + 20;
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char *name;
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int dig = isdigit(dev[strlen(dev)-1]);
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char orig[1001];
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char sym[1024];
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int err;
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if (cnt == 0)
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cnt = 4;
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if (lstat(dev, &stb)!= 0)
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return;
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if (S_ISBLK(stb.st_mode)) {
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major_num = major(stb.st_rdev);
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minor_num = minor(stb.st_rdev);
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odig = -1;
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} else if (S_ISLNK(stb.st_mode)) {
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int len;
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len = readlink(dev, orig, sizeof(orig));
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if (len < 0 || len >= (int)sizeof(orig))
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return;
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orig[len] = 0;
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odig = isdigit(orig[len-1]);
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major_num = -1;
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minor_num = -1;
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} else
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return;
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name = xmalloc(nlen);
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for (i = 1; i <= cnt ; i++) {
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struct stat stb2;
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snprintf(name, nlen, "%s%s%d", dev, dig?"p":"", i);
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if (stat(name, &stb2) == 0) {
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if (!S_ISBLK(stb2.st_mode) || !S_ISBLK(stb.st_mode))
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continue;
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if (stb2.st_rdev == makedev(major_num, minor_num+i))
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continue;
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unlink(name);
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} else {
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stb2 = stb;
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}
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if (S_ISBLK(stb.st_mode)) {
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if (mknod(name, S_IFBLK | 0600,
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makedev(major_num, minor_num+i)))
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perror("mknod");
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if (chown(name, stb2.st_uid, stb2.st_gid))
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perror("chown");
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if (chmod(name, stb2.st_mode & 07777))
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perror("chmod");
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err = 0;
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} else {
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snprintf(sym, sizeof(sym), "%s%s%d", orig, odig?"p":"", i);
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err = symlink(sym, name);
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}
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if (err == 0 && stat(name, &stb2) == 0)
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add_dev(name, &stb2, 0, NULL);
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}
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free(name);
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}
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int create_named_array(char *devnm)
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{
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int fd;
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int n = -1;
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static const char new_array_file[] = {
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"/sys/module/md_mod/parameters/new_array"
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};
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fd = open(new_array_file, O_WRONLY);
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if (fd < 0 && errno == ENOENT) {
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if (system("modprobe md_mod") == 0)
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fd = open(new_array_file, O_WRONLY);
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}
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if (fd >= 0) {
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n = write(fd, devnm, strlen(devnm));
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close(fd);
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}
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if (fd < 0 || n != (int)strlen(devnm)) {
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pr_err("Fail to create %s when using %s, fallback to creation via node\n",
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devnm, new_array_file);
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return 0;
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}
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return 1;
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}
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/*
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* We need a new md device to assemble/build/create an array.
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* 'dev' is a name given us by the user (command line or mdadm.conf)
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* It might start with /dev or /dev/md any might end with a digit
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* string.
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* If it starts with just /dev, it must be /dev/mdX or /dev/md_dX
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* If it ends with a digit string, then it must be as above, or
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* 'trustworthy' must be 'METADATA' and the 'dev' must be
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* /dev/md/'name'NN or 'name'NN
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* If it doesn't end with a digit string, it must be /dev/md/'name'
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* or 'name' or must be NULL.
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* If the digit string is present, it gives the minor number to use
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* If not, we choose a high, unused minor number.
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* If the 'dev' is a standard name, it devices whether 'md' or 'mdp'.
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* else if the name is 'd[0-9]+' then we use mdp
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* else if trustworthy is 'METADATA' we use md
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* else the choice depends on 'autof'.
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* If name is NULL it is assumed to match whatever dev provides.
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* If both name and dev are NULL, we choose a name 'mdXX' or 'mdpXX'
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*
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* If 'name' is given, and 'trustworthy' is 'foreign' and name is not
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* supported by 'dev', we add a "_%d" suffix based on the minor number
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* use that.
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*
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* If udev is configured, we create a temporary device, open it, and
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* unlink it.
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* If not, we create the /dev/mdXX device, and if name is usable,
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* /dev/md/name
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* In any case we return /dev/md/name or (if that isn't available)
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* /dev/mdXX in 'chosen'.
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*
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* When we create devices, we use uid/gid/umask from config file.
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*/
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int create_mddev(char *dev, char *name, int autof, int trustworthy,
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char *chosen, int block_udev)
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{
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int mdfd;
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struct stat stb;
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int num = -1;
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int use_mdp = -1;
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struct createinfo *ci = conf_get_create_info();
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int parts;
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char *cname;
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char devname[37];
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char devnm[32];
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char cbuf[400];
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if (!use_udev())
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block_udev = 0;
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if (chosen == NULL)
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chosen = cbuf;
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if (autof == 0)
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autof = ci->autof;
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parts = autof >> 3;
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autof &= 7;
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strcpy(chosen, DEV_MD_DIR);
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cname = chosen + strlen(chosen);
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if (dev) {
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if (strncmp(dev, DEV_MD_DIR, DEV_MD_DIR_LEN) == 0) {
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strcpy(cname, dev + DEV_MD_DIR_LEN);
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} else if (strncmp(dev, "/dev/", 5) == 0) {
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char *e = dev + strlen(dev);
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while (e > dev && isdigit(e[-1]))
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e--;
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if (e[0])
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num = strtoul(e, NULL, 10);
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strcpy(cname, dev+5);
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cname[e-(dev+5)] = 0;
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/* name *must* be mdXX or md_dXX in this context */
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if (num < 0 ||
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(strcmp(cname, "md") != 0 && strcmp(cname, "md_d") != 0)) {
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pr_err("%s is an invalid name for an md device. Try /dev/md/%s\n",
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dev, dev+5);
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return -1;
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}
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if (strcmp(cname, "md") == 0)
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use_mdp = 0;
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else
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use_mdp = 1;
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/* recreate name: /dev/md/0 or /dev/md/d0 */
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sprintf(cname, "%s%d", use_mdp?"d":"", num);
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} else
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strcpy(cname, dev);
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/* 'cname' must not contain a slash, and may not be
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* empty.
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*/
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if (strchr(cname, '/') != NULL) {
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pr_err("%s is an invalid name for an md device.\n", dev);
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return -1;
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}
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if (cname[0] == 0) {
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pr_err("%s is an invalid name for an md device (empty!).\n", dev);
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return -1;
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}
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if (num < 0) {
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/* If cname is 'N' or 'dN', we get dev number
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* from there.
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*/
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char *sp = cname;
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char *ep;
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if (cname[0] == 'd')
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sp++;
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if (isdigit(sp[0]))
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num = strtoul(sp, &ep, 10);
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else
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ep = sp;
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if (ep == sp || *ep || num < 0)
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num = -1;
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else if (cname[0] == 'd')
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use_mdp = 1;
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else
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use_mdp = 0;
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}
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}
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/* Now determine device number */
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/* named 'METADATA' cannot use 'mdp'. */
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if (name && name[0] == 0)
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name = NULL;
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if (name && trustworthy == METADATA && use_mdp == 1) {
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pr_err("%s is not allowed for a %s container. Consider /dev/md%d.\n", dev, name, num);
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return -1;
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}
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if (name && trustworthy == METADATA)
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use_mdp = 0;
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if (use_mdp == -1) {
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if (autof == 4 || autof == 6)
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use_mdp = 1;
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else
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use_mdp = 0;
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}
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if (num < 0 && trustworthy == LOCAL && name) {
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/* if name is numeric, possibly prefixed by
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* 'md' or '/dev/md', use that for num
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* if it is not already in use */
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char *ep;
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char *n2 = name;
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if (strncmp(n2, "/dev/", 5) == 0)
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n2 += 5;
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if (strncmp(n2, "md", 2) == 0)
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n2 += 2;
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if (*n2 == '/')
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n2++;
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num = strtoul(n2, &ep, 10);
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if (ep == n2 || *ep)
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num = -1;
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else {
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sprintf(devnm, "md%s%d", use_mdp ? "_d":"", num);
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if (mddev_busy(devnm))
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num = -1;
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}
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}
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if (cname[0] == 0 && name) {
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/* Need to find a name if we can
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* We don't completely trust 'name'. Truncate to
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* reasonable length and remove '/'
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*/
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char *cp;
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struct map_ent *map = NULL;
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int conflict = 1;
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int unum = 0;
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int cnlen;
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strncpy(cname, name, 200);
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cname[200] = 0;
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for (cp = cname; *cp ; cp++)
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switch (*cp) {
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case '/':
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*cp = '-';
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break;
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case ' ':
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case '\t':
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*cp = '_';
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break;
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}
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if (trustworthy == LOCAL ||
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(trustworthy == FOREIGN && strchr(cname, ':') != NULL)) {
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/* Only need suffix if there is a conflict */
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if (map_by_name(&map, cname) == NULL)
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conflict = 0;
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}
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cnlen = strlen(cname);
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while (conflict) {
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if (trustworthy == METADATA && !isdigit(cname[cnlen-1]))
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sprintf(cname+cnlen, "%d", unum);
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else
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/* add _%d to FOREIGN array that don't
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* a 'host:' prefix
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*/
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sprintf(cname+cnlen, "_%d", unum);
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unum++;
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if (map_by_name(&map, cname) == NULL)
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conflict = 0;
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}
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}
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devnm[0] = 0;
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if (num < 0 && cname && ci->names) {
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sprintf(devnm, "md_%s", cname);
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if (block_udev)
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udev_block(devnm);
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if (!create_named_array(devnm)) {
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devnm[0] = 0;
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udev_unblock();
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}
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}
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if (num >= 0) {
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sprintf(devnm, "md%d", num);
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if (block_udev)
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udev_block(devnm);
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if (!create_named_array(devnm)) {
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devnm[0] = 0;
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udev_unblock();
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}
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}
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if (devnm[0] == 0) {
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if (num < 0) {
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/* need to choose a free number. */
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char *_devnm = find_free_devnm(use_mdp);
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if (_devnm == NULL) {
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pr_err("No avail md devices - aborting\n");
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return -1;
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}
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strcpy(devnm, _devnm);
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} else {
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sprintf(devnm, "%s%d", use_mdp?"md_d":"md", num);
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if (mddev_busy(devnm)) {
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pr_err("%s is already in use.\n",
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dev);
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return -1;
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}
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}
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if (block_udev)
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udev_block(devnm);
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create_named_array(devnm);
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}
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sprintf(devname, "/dev/%s", devnm);
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if (dev && dev[0] == '/')
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strcpy(chosen, dev);
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else if (cname[0] == 0)
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strcpy(chosen, devname);
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/* We have a device number and name.
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* If we cannot detect udev, we need to make
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* devices and links ourselves.
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*/
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if (!use_udev()) {
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/* Make sure 'devname' exists and 'chosen' is a symlink to it */
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if (lstat(devname, &stb) == 0) {
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/* Must be the correct device, else error */
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if ((stb.st_mode&S_IFMT) != S_IFBLK ||
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stb.st_rdev != devnm2devid(devnm)) {
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pr_err("%s exists but looks wrong, please fix\n",
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devname);
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return -1;
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}
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} else {
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if (mknod(devname, S_IFBLK|0600,
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devnm2devid(devnm)) != 0) {
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pr_err("failed to create %s\n",
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devname);
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return -1;
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}
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if (chown(devname, ci->uid, ci->gid))
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perror("chown");
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if (chmod(devname, ci->mode))
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perror("chmod");
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stat(devname, &stb);
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add_dev(devname, &stb, 0, NULL);
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}
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if (use_mdp == 1)
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make_parts(devname, parts);
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if (strcmp(chosen, devname) != 0) {
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if (mkdir(DEV_NUM_PREF, 0700) == 0) {
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if (chown(DEV_NUM_PREF, ci->uid, ci->gid))
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perror("chown " DEV_NUM_PREF);
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if (chmod(DEV_NUM_PREF, ci->mode | ((ci->mode >> 2) & 0111)))
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perror("chmod " DEV_NUM_PREF);
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}
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if (dev && strcmp(chosen, dev) == 0)
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/* We know we are allowed to use this name */
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unlink(chosen);
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if (lstat(chosen, &stb) == 0) {
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char buf[300];
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ssize_t link_len = readlink(chosen, buf, sizeof(buf)-1);
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if (link_len >= 0)
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buf[link_len] = '\0';
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if ((stb.st_mode & S_IFMT) != S_IFLNK ||
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link_len < 0 ||
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strcmp(buf, devname) != 0) {
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pr_err("%s exists - ignoring\n",
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chosen);
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strcpy(chosen, devname);
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}
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} else if (symlink(devname, chosen) != 0)
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pr_err("failed to create %s: %s\n",
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chosen, strerror(errno));
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if (use_mdp && strcmp(chosen, devname) != 0)
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make_parts(chosen, parts);
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}
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}
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mdfd = open_dev_excl(devnm);
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if (mdfd < 0)
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pr_err("unexpected failure opening %s\n",
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devname);
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return mdfd;
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}
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/* Open this and check that it is an md device.
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* On success, return filedescriptor.
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* On failure, return -1 if it doesn't exist,
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* or -2 if it exists but is not an md device.
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*/
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int open_mddev(char *dev, int report_errors)
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{
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int mdfd = open(dev, O_RDONLY);
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if (mdfd < 0) {
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if (report_errors)
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pr_err("error opening %s: %s\n",
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dev, strerror(errno));
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return -1;
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}
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if (md_array_valid(mdfd) == 0) {
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close(mdfd);
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if (report_errors)
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pr_err("%s does not appear to be an md device\n", dev);
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return -2;
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}
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return mdfd;
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}
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/**
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* is_mddev() - check that file name passed is an md device.
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* @dev: file name that has to be checked.
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* Return: 1 if file passed is an md device, 0 if not.
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*/
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int is_mddev(char *dev)
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{
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int fd = open_mddev(dev, 1);
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if (fd >= 0) {
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close(fd);
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return 1;
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}
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return 0;
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}
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char *find_free_devnm(int use_partitions)
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{
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static char devnm[32];
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int devnum;
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for (devnum = 127; devnum != 128;
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devnum = devnum ? devnum-1 : (1<<9)-1) {
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if (use_partitions)
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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 (!use_udev()) {
|
|
/* 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;
|
|
}
|