295 lines
7.9 KiB
C
295 lines
7.9 KiB
C
/*
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* mdadm - manage Linux "md" devices aka RAID arrays.
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*
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* Copyright (C) 2001-2006 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@cse.unsw.edu.au>
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* Paper: Neil Brown
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* School of Computer Science and Engineering
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* The University of New South Wales
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* Sydney, 2052
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* Australia
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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_dev_symlink(char *dev)
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{
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char *new = strdup(dev);
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if (!new) return;
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/* /dev/md/0 -> /dev/md0
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* /dev/md/d0 -> /dev/md_d0
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*/
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if (isdigit(new[8]))
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strcpy(new+7, new+8);
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else
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new[7] = '_';
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if (symlink(dev+5, new))
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perror(new);
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}
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void make_parts(char *dev, int cnt, int symlinks)
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{
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/* make 'cnt' partition devices for 'dev'
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* We use the major/minor from dev and add 1..cnt
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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, minor;
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int i;
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int nlen = strlen(dev) + 20;
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char *name = malloc(nlen);
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int dig = isdigit(dev[strlen(dev)-1]);
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if (cnt==0) cnt=4;
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if (stat(dev, &stb)!= 0)
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return;
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if (!S_ISBLK(stb.st_mode))
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return;
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major = major(stb.st_rdev);
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minor = minor(stb.st_rdev);
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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))
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continue;
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if (stb2.st_rdev == makedev(major, minor+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 (mknod(name, S_IFBLK | 0600, makedev(major, minor+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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if (symlinks && strncmp(name, "/dev/md/", 8) == 0)
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make_dev_symlink(name);
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stat(name, &stb2);
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add_dev(name, &stb2, 0, NULL);
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}
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}
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/*
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* Open a given md device, and check that it really is one.
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* If 'autof' is given, then we need to create, or recreate, the md device.
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* If the name already exists, and is not a block device, we fail.
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* If it exists and is not an md device, is not the right type (partitioned or not),
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* or is currently in-use, we remove the device, but remember the owner and mode.
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* If it now doesn't exist, we find a new md array and create the device.
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* Default ownership/mode comes from config file.
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*/
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int open_mddev(char *dev, int autof)
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{
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int mdfd;
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struct stat stb;
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int major = MD_MAJOR;
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int minor = 0;
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int must_remove = 0;
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struct mdstat_ent *mdlist;
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int num;
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struct createinfo *ci = conf_get_create_info();
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int parts;
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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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if (autof && autof != 1) {
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/* autof is set, so we need to check that the name is ok,
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* and possibly create one if not
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*/
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int std;
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stb.st_mode = 0;
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if (stat(dev, &stb)==0 && ! S_ISBLK(stb.st_mode)) {
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fprintf(stderr, Name ": %s is not a block device.\n",
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dev);
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return -1;
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}
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/* check major number is correct */
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num = -1;
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std = is_standard(dev, &num);
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if (std>0) major = get_mdp_major();
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switch(autof) {
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case 2: /* only create is_standard names */
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if (!std && !stb.st_mode) {
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fprintf(stderr, Name
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": %s does not exist and is not a 'standard' name "
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"so it cannot be created\n", dev);
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return -1;
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}
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break;
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case 3: /* create md, reject std>0 */
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if (std > 0) {
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fprintf(stderr, Name ": that --auto option "
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"not compatable with device named %s\n", dev);
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return -1;
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}
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break;
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case 4: /* create mdp, reject std<0 */
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if (std < 0) {
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fprintf(stderr, Name ": that --auto option "
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"not compatable with device named %s\n", dev);
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return -1;
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}
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break;
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case 5: /* default to md if not standard */
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break;
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case 6: /* default to mdp if not standard */
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if (std == 0) major = get_mdp_major();
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break;
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}
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/* major is final. num is -1 if not standard */
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if (stb.st_mode && major(stb.st_rdev) != major)
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must_remove = 1;
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if (stb.st_mode && !must_remove) {
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/* looks ok, see if it is available */
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mdfd = open(dev, O_RDWR, 0);
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if (mdfd < 0) {
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fprintf(stderr, Name ": error opening %s: %s\n",
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dev, strerror(errno));
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return -1;
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} else if (md_get_version(mdfd) <= 0) {
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fprintf(stderr, Name ": %s does not appear to be an md device\n",
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dev);
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close(mdfd);
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return -1;
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}
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if (major != MD_MAJOR && parts > 0)
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make_parts(dev, parts, ci->symlinks);
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return mdfd;
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}
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/* Ok, need to find a minor that is not in use.
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* If the device name is in a 'standard' format,
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* intuit the minor from that, else
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* easiest to read /proc/mdstat, and hunt through for
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* an unused number
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*/
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if (num < 0) {
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/* need to pick an unused number */
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mdlist = mdstat_read(0, 0);
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/* Choose a large number. Start from 127 and search down,
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* but if nothing is found, start really big
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*/
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for (num = 127 ; num != 128 ; num = num ? num-1 : (1<<22)-1) {
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struct mdstat_ent *me;
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int devnum = num;
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if (major != MD_MAJOR)
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devnum = -1-num;
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for (me=mdlist; me; me=me->next)
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if (me->devnum == devnum)
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break;
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if (!me) {
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/* doesn't exist in mdstat.
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* make sure it is new to /dev too
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*/
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char *dn;
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if (major != MD_MAJOR)
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minor = num << MdpMinorShift;
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else
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minor = num;
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dn = map_dev(major,minor, 0);
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if (dn==NULL || is_standard(dn, NULL)) {
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/* this number only used by a 'standard' name,
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* so it is safe to use
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*/
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break;
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}
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}
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}
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} else if (major == MD_MAJOR)
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minor = num;
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else
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minor = num << MdpMinorShift;
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/* major and minor have been chosen */
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/* If it was a 'standard' name and it is in-use, then
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* the device could already be correct
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*/
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if (stb.st_mode && major(stb.st_rdev) == major &&
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minor(stb.st_rdev) == minor)
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;
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else {
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if (major(makedev(major,minor)) != major ||
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minor(makedev(major,minor)) != minor) {
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fprintf(stderr, Name ": Need newer C library to use more than 4 partitionable md devices, sorry\n");
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return -1;
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}
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if (must_remove)
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unlink(dev);
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if (strncmp(dev, "/dev/md/", 8) == 0) {
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if (mkdir("/dev/md",0700)==0) {
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if (chown("/dev/md", ci->uid, ci->gid))
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perror("chown /dev/md");
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if (chmod("/dev/md", ci->mode| ((ci->mode>>2) & 0111)))
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perror("chmod /dev/md");
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}
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}
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if (mknod(dev, S_IFBLK|0600, makedev(major, minor))!= 0) {
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fprintf(stderr, Name ": failed to create %s\n", dev);
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return -1;
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}
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if (must_remove) {
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if (chown(dev, stb.st_uid, stb.st_gid))
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perror("chown");
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if (chmod(dev, stb.st_mode & 07777))
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perror("chmod");
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} else {
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if (chown(dev, ci->uid, ci->gid))
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perror("chown");
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if (chmod(dev, ci->mode))
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perror("chmod");
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}
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stat(dev, &stb);
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add_dev(dev, &stb, 0, NULL);
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if (ci->symlinks && strncmp(dev, "/dev/md/", 8) == 0)
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make_dev_symlink(dev);
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if (major != MD_MAJOR)
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make_parts(dev,parts, ci->symlinks);
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}
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}
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mdfd = open(dev, O_RDWR, 0);
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if (mdfd < 0)
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fprintf(stderr, Name ": error opening %s: %s\n",
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dev, strerror(errno));
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else if (md_get_version(mdfd) <= 0) {
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fprintf(stderr, Name ": %s does not appear to be an md device\n",
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dev);
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close(mdfd);
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mdfd = -1;
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}
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return mdfd;
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}
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