/release/src/router/mdadm/mdopen.c
C | 342 lines | 246 code | 18 blank | 78 comment | 108 complexity | c2f8d6df2a9aacd973b3423822505925 MD5 | raw file
- /*
- * mdadm - manage Linux "md" devices aka RAID arrays.
- *
- * Copyright (C) 2001-2006 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@cse.unsw.edu.au>
- * Paper: Neil Brown
- * School of Computer Science and Engineering
- * The University of New South Wales
- * Sydney, 2052
- * Australia
- */
- #include "mdadm.h"
- #include "md_p.h"
- #include <ctype.h>
- void make_dev_symlink(char *dev)
- {
- char *new = strdup(dev);
- if (!new) return;
- /* /dev/md/0 -> /dev/md0
- * /dev/md/d0 -> /dev/md_d0
- */
- if (isdigit(new[8]))
- strcpy(new+7, new+8);
- else
- new[7] = '_';
- if (symlink(dev+5, new))
- perror(new);
- }
- void make_parts(char *dev, int cnt, int symlinks)
- {
- /* make 'cnt' partition devices for 'dev'
- * We use the major/minor from dev and add 1..cnt
- * If dev ends with a digit, we add "p%d" else "%d"
- * If the name exists, we use it's owner/mode,
- * else that of dev
- */
- struct stat stb;
- int major, minor;
- int i;
- int nlen = strlen(dev) + 20;
- char *name = malloc(nlen);
- int dig = isdigit(dev[strlen(dev)-1]);
- if (cnt==0) cnt=4;
- if (stat(dev, &stb)!= 0)
- return;
- if (!S_ISBLK(stb.st_mode))
- return;
- major = major(stb.st_rdev);
- minor = minor(stb.st_rdev);
- for (i=1; i <= cnt ; i++) {
- struct stat stb2;
- snprintf(name, nlen, "%s%s%d", dev, dig?"p":"", i);
- if (stat(name, &stb2)==0) {
- if (!S_ISBLK(stb2.st_mode))
- continue;
- if (stb2.st_rdev == makedev(major, minor+i))
- continue;
- unlink(name);
- } else {
- stb2 = stb;
- }
- if (mknod(name, S_IFBLK | 0600, makedev(major, minor+i)))
- perror("mknod");
- if (chown(name, stb2.st_uid, stb2.st_gid))
- perror("chown");
- if (chmod(name, stb2.st_mode & 07777))
- perror("chmod");
- if (symlinks && strncmp(name, "/dev/md/", 8) == 0)
- make_dev_symlink(name);
- stat(name, &stb2);
- add_dev(name, &stb2, 0, NULL);
- }
- }
- /*
- * Open a given md device, and check that it really is one.
- * If 'autof' is given, then we need to create, or recreate, the md device.
- * If the name already exists, and is not a block device, we fail.
- * If it exists and is not an md device, is not the right type (partitioned or not),
- * or is currently in-use, we remove the device, but remember the owner and mode.
- * If it now doesn't exist, we find a new md array and create the device.
- * Default ownership/mode comes from config file.
- */
- int open_mddev(char *dev, int autof)
- {
- int mdfd;
- struct stat stb;
- int major = MD_MAJOR;
- int minor = 0;
- int must_remove = 0;
- struct mdstat_ent *mdlist;
- int num;
- struct createinfo *ci = conf_get_create_info();
- int parts;
- if (autof == 0)
- autof = ci->autof;
- parts = autof >> 3;
- autof &= 7;
- if (autof && autof != 1) {
- /* autof is set, so we need to check that the name is ok,
- * and possibly create one if not
- */
- int std;
- stb.st_mode = 0;
- if (stat(dev, &stb)==0 && ! S_ISBLK(stb.st_mode)) {
- fprintf(stderr, Name ": %s is not a block device.\n",
- dev);
- return -1;
- }
- /* check major number is correct */
- num = -1;
- std = is_standard(dev, &num);
- if (std>0) major = get_mdp_major();
- switch(autof) {
- case 2: /* only create is_standard names */
- if (!std && !stb.st_mode) {
- fprintf(stderr, Name
- ": %s does not exist and is not a 'standard' name "
- "so it cannot be created\n", dev);
- return -1;
- }
- break;
- case 3: /* create md, reject std>0 */
- if (std > 0) {
- fprintf(stderr, Name ": that --auto option "
- "not compatable with device named %s\n", dev);
- return -1;
- }
- break;
- case 4: /* create mdp, reject std<0 */
- if (std < 0) {
- fprintf(stderr, Name ": that --auto option "
- "not compatable with device named %s\n", dev);
- return -1;
- }
- break;
- case 5: /* default to md if not standard */
- break;
- case 6: /* default to mdp if not standard */
- if (std == 0) major = get_mdp_major();
- break;
- }
- /* major is final. num is -1 if not standard */
- if (stb.st_mode && major(stb.st_rdev) != major)
- must_remove = 1;
- if (stb.st_mode && !must_remove) {
- /* looks ok, see if it is available */
- mdfd = open(dev, O_RDWR, 0);
- if (mdfd < 0) {
- fprintf(stderr, Name ": error opening %s: %s\n",
- dev, strerror(errno));
- return -1;
- } else if (md_get_version(mdfd) <= 0) {
- fprintf(stderr, Name ": %s does not appear to be an md device\n",
- dev);
- close(mdfd);
- return -1;
- }
- if (major != MD_MAJOR && parts > 0)
- make_parts(dev, parts, ci->symlinks);
- return mdfd;
- }
- /* Ok, need to find a minor that is not in use.
- * If the device name is in a 'standard' format,
- * intuit the minor from that, else
- * easiest to read /proc/mdstat, and hunt through for
- * an unused number
- */
- if (num < 0) {
- /* need to pick an unused number */
- mdlist = mdstat_read(0, 0);
- /* Choose a large number. Start from 127 and search down,
- * but if nothing is found, start really big
- */
- for (num = 127 ; num != 128 ; num = num ? num-1 : (1<<22)-1) {
- struct mdstat_ent *me;
- int devnum = num;
- if (major != MD_MAJOR)
- devnum = -1-num;
- for (me=mdlist; me; me=me->next)
- if (me->devnum == devnum)
- break;
- if (!me) {
- /* doesn't exist in mdstat.
- * make sure it is new to /dev too
- */
- char *dn;
- if (major != MD_MAJOR)
- minor = num << MdpMinorShift;
- else
- minor = num;
- dn = map_dev(major,minor, 0);
- if (dn==NULL || is_standard(dn, NULL)) {
- /* this number only used by a 'standard' name,
- * so it is safe to use
- */
- break;
- }
- }
- }
- } else if (major == MD_MAJOR)
- minor = num;
- else
- minor = num << MdpMinorShift;
- /* major and minor have been chosen */
- /* If it was a 'standard' name and it is in-use, then
- * the device could already be correct
- */
- if (stb.st_mode && major(stb.st_rdev) == major &&
- minor(stb.st_rdev) == minor)
- ;
- else {
- if (major(makedev(major,minor)) != major ||
- minor(makedev(major,minor)) != minor) {
- fprintf(stderr, Name ": Need newer C library to use more than 4 partitionable md devices, sorry\n");
- return -1;
- }
- if (must_remove)
- unlink(dev);
- if (strncmp(dev, "/dev/md/", 8) == 0) {
- if (mkdir("/dev/md",0700)==0) {
- if (chown("/dev/md", ci->uid, ci->gid))
- perror("chown /dev/md");
- if (chmod("/dev/md", ci->mode| ((ci->mode>>2) & 0111)))
- perror("chmod /dev/md");
- }
- }
- if (mknod(dev, S_IFBLK|0600, makedev(major, minor))!= 0) {
- fprintf(stderr, Name ": failed to create %s\n", dev);
- return -1;
- }
- if (must_remove) {
- if (chown(dev, stb.st_uid, stb.st_gid))
- perror("chown");
- if (chmod(dev, stb.st_mode & 07777))
- perror("chmod");
- } else {
- if (chown(dev, ci->uid, ci->gid))
- perror("chown");
- if (chmod(dev, ci->mode))
- perror("chmod");
- }
- stat(dev, &stb);
- add_dev(dev, &stb, 0, NULL);
- if (ci->symlinks && strncmp(dev, "/dev/md/", 8) == 0)
- make_dev_symlink(dev);
- if (major != MD_MAJOR)
- make_parts(dev,parts, ci->symlinks);
- }
- }
- mdfd = open(dev, O_RDWR, 0);
- if (mdfd < 0)
- fprintf(stderr, Name ": error opening %s: %s\n",
- dev, strerror(errno));
- else if (md_get_version(mdfd) <= 0) {
- fprintf(stderr, Name ": %s does not appear to be an md device\n",
- dev);
- close(mdfd);
- mdfd = -1;
- }
- return mdfd;
- }
- int open_mddev_devnum(char *devname, int devnum, char *name, char *chosen_name)
- {
- /* Open the md device with number 'devnum', possibly using 'devname',
- * possibly constructing a name with 'name', but in any case, copying
- * the name into 'chosen_name'
- */
- int major, minor;
- struct stat stb;
- if (devname)
- strcpy(chosen_name, devname);
- else if (name && strchr(name,'/') == NULL) {
- char *n = strchr(name, ':');
- if (n) n++; else n = name;
- if (isdigit(*n) && devnum < 0)
- sprintf(chosen_name, "/dev/md/d%s", n);
- else
- sprintf(chosen_name, "/dev/md/%s", n);
- } else {
- if (devnum >= 0)
- sprintf(chosen_name, "/dev/md%d", devnum);
- else
- sprintf(chosen_name, "/dev/md/d%d", -1-devnum);
- }
- if (devnum >= 0) {
- major = MD_MAJOR;
- minor = devnum;
- } else {
- major = get_mdp_major();
- minor = (-1-devnum) << 6;
- }
- if (stat(chosen_name, &stb) == 0) {
- /* It already exists. Check it is right. */
- if ( ! S_ISBLK(stb.st_mode) ||
- stb.st_rdev != makedev(major, minor)) {
- errno = EEXIST;
- return -1;
- }
- } else {
- if (mknod(chosen_name, S_IFBLK | 0600,
- makedev(major, minor)) != 0) {
- return -1;
- }
- /* FIXME chown/chmod ?? */
- }
- return open(chosen_name, O_RDWR);
- }