/*
* mdadm - manage Linux "md" devices aka RAID arrays.
*
* Copyright (C) 2001-2013 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 "udev.h"
#include "md_p.h"
#include "xmalloc.h"
#include <ctype.h>
int create_named_array(char *devnm)
{
int fd;
int n = -1;
static const char new_array_file[] = {
"/sys/module/md_mod/parameters/new_array"
};
fd = open(new_array_file, O_WRONLY);
if (fd < 0 && errno == ENOENT) {
if (system("modprobe md_mod") == 0)
fd = open(new_array_file, O_WRONLY);
}
if (fd >= 0) {
n = write(fd, devnm, strlen(devnm));
close(fd);
}
if (fd < 0 || n != (int)strlen(devnm)) {
pr_err("Fail to create %s when using %s, fallback to creation via node\n",
devnm, new_array_file);
return 0;
}
return 1;
}
char *find_free_devnm(void)
{
static char devnm[MD_NAME_MAX];
int devnum;
for (devnum = 127; devnum != 128; devnum = devnum ? devnum - 1 : 511) {
sprintf(devnm, "md%d", devnum);
if (mddev_busy(devnm))
continue;
if (!conf_name_is_free(devnm))
continue;
if (!udev_is_available()) {
/* make sure it is new to /dev too*/
dev_t devid = devnm2devid(devnm);
if (devid && map_dev(major(devid), minor(devid), 0))
continue;
}
break;
}
if (devnum == 128)
return NULL;
return devnm;
}
/*
* We need a new md device to assemble/build/create an array.
* 'dev' is a name given us by the user (command line or mdadm.conf)
* It might start with /dev or /dev/md any might end with a digit
* string.
* If it starts with just /dev, it must be /dev/mdX or /dev/md_dX
* If it ends with a digit string, then it must be as above, or
* 'trustworthy' must be 'METADATA' and the 'dev' must be
* /dev/md/'name'NN or 'name'NN
* If it doesn't end with a digit string, it must be /dev/md/'name'
* or 'name' or must be NULL.
* If the digit string is present, it gives the minor number to use
* If not, we choose a high, unused minor number.
* If the 'dev' is a standard name, it devices whether 'md' or 'mdp'.
* else if the name is 'd[0-9]+' then we use mdp
* else if trustworthy is 'METADATA' we use md
* else the choice depends on 'autof'.
* If name is NULL it is assumed to match whatever dev provides.
* If both name and dev are NULL, we choose a name 'mdXX' or 'mdpXX'
*
* If 'name' is given, and 'trustworthy' is 'foreign' and name is not
* supported by 'dev', we add a "_%d" suffix based on the minor number
* use that.
*
* If udev is configured, we create a temporary device, open it, and
* unlink it.
* If not, we create the /dev/mdXX device, and if name is usable,
* /dev/md/name
* In any case we return /dev/md/name or (if that isn't available)
* /dev/mdXX in 'chosen'.
*
* When we create devices, we use uid/gid/umask from config file.
*/
int create_mddev(char *dev, char *name, int trustworthy,
char *chosen, int block_udev)
{
int mdfd;
struct stat stb;
int num = -1;
struct createinfo *ci = conf_get_create_info();
char *cname;
char devname[37];
char devnm[32];
char cbuf[400];
if (!udev_is_available())
block_udev = 0;
if (chosen == NULL)
chosen = cbuf;
strcpy(chosen, DEV_MD_DIR);
cname = chosen + strlen(chosen);
if (dev) {
if (strncmp(dev, DEV_MD_DIR, DEV_MD_DIR_LEN) == 0) {
snprintf(cname, MD_NAME_MAX, "%s", dev + DEV_MD_DIR_LEN);
} else if (strncmp(dev, "/dev/", 5) == 0) {
char *e = dev + strlen(dev);
while (e > dev && isdigit(e[-1]))
e--;
if (e[0])
num = strtoul(e, NULL, 10);
snprintf(cname, MD_NAME_MAX, "%s", dev + 5);
cname[e-(dev+5)] = 0;
/* name *must* be mdXX or md_dXX in this context */
if (num < 0 ||
(strcmp(cname, "md") != 0 && strcmp(cname, "md_d") != 0)) {
pr_err("%s is an invalid name for an md device. Try /dev/md/%s\n",
dev, dev+5);
return -1;
}
/* recreate name: /dev/md/0 or /dev/md/d0 */
sprintf(cname, "%d", num);
} else
strcpy(cname, dev);
/* 'cname' must not contain a slash, and may not be
* empty.
*/
if (strchr(cname, '/') != NULL) {
pr_err("%s is an invalid name for an md device.\n", dev);
return -1;
}
if (cname[0] == 0) {
pr_err("%s is an invalid name for an md device (empty!).\n", dev);
return -1;
}
if (num < 0) {
/* If cname is 'N' or 'dN', we get dev number
* from there.
*/
char *sp = cname;
char *ep;
if (cname[0] == 'd')
sp++;
if (isdigit(sp[0]))
num = strtoul(sp, &ep, 10);
else
ep = sp;
if (ep == sp || *ep || num < 0)
num = -1;
}
}
/* Now determine device number */
if (name && name[0] == 0)
name = NULL;
if (num < 0 && trustworthy == LOCAL && name) {
/* if name is numeric, possibly prefixed by
* 'md' or '/dev/md', use that for num
* if it is not already in use */
char *ep;
char *n2 = name;
if (strncmp(n2, "/dev/", 5) == 0)
n2 += 5;
if (strncmp(n2, "md", 2) == 0)
n2 += 2;
if (*n2 == '/')
n2++;
num = strtoul(n2, &ep, 10);
if (ep == n2 || *ep)
num = -1;
else {
sprintf(devnm, "md%d", num);
if (mddev_busy(devnm))
num = -1;
}
}
if (cname[0] == 0 && name) {
/* Need to find a name if we can
* We don't completely trust 'name'. Truncate to
* reasonable length and remove '/'
*/
char *cp;
struct map_ent *map = NULL;
int conflict = 1;
int unum = 0;
int cnlen;
strncpy(cname, name, 200);
cname[200] = 0;
for (cp = cname; *cp ; cp++)
switch (*cp) {
case '/':
*cp = '-';
break;
case ' ':
case '\t':
*cp = '_';
break;
}
if (trustworthy == LOCAL ||
(trustworthy == FOREIGN && strchr(cname, ':') != NULL)) {
/* Only need suffix if there is a conflict */
if (map_by_name(&map, cname) == NULL)
conflict = 0;
}
cnlen = strlen(cname);
while (conflict) {
if (trustworthy == METADATA && !isdigit(cname[cnlen-1]))
sprintf(cname+cnlen, "%d", unum);
else
/* add _%d to FOREIGN array that don't
* a 'host:' prefix
*/
sprintf(cname+cnlen, "_%d", unum);
unum++;
if (map_by_name(&map, cname) == NULL)
conflict = 0;
}
}
devnm[0] = 0;
if (num < 0 && cname && ci->names) {
sprintf(devnm, "md_%s", cname);
if (block_udev && udev_block(devnm) != UDEV_STATUS_SUCCESS)
return -1;
if (!create_named_array(devnm)) {
devnm[0] = 0;
udev_unblock();
}
}
if (num >= 0) {
sprintf(devnm, "md%d", num);
if (block_udev && udev_block(devnm) != UDEV_STATUS_SUCCESS)
return -1;
if (!create_named_array(devnm)) {
devnm[0] = 0;
udev_unblock();
}
}
if (devnm[0] == 0) {
if (num < 0) {
/* need to choose a free number. */
char *_devnm = find_free_devnm();
if (!_devnm) {
pr_err("No avail md devices - aborting\n");
return -1;
}
strcpy(devnm, _devnm);
} else {
sprintf(devnm, "md%d", num);
if (mddev_busy(devnm)) {
pr_err("%s is already in use.\n",
dev);
return -1;
}
}
if (block_udev && udev_block(devnm) != UDEV_STATUS_SUCCESS)
return -1;
create_named_array(devnm);
}
sprintf(devname, "/dev/%s", devnm);
if (dev && dev[0] == '/' && strlen(dev) < 400)
strcpy(chosen, dev);
else if (cname[0] == 0)
strcpy(chosen, devname);
/* We have a device number and name.
* If we cannot detect udev, we need to make
* devices and links ourselves.
*/
if (!udev_is_available()) {
/* Make sure 'devname' exists and 'chosen' is a symlink to it */
if (lstat(devname, &stb) == 0) {
/* Must be the correct device, else error */
if ((stb.st_mode&S_IFMT) != S_IFBLK ||
stb.st_rdev != devnm2devid(devnm)) {
pr_err("%s exists but looks wrong, please fix\n",
devname);
return -1;
}
} else {
if (mknod(devname, S_IFBLK|0600,
devnm2devid(devnm)) != 0) {
pr_err("failed to create %s\n",
devname);
return -1;
}
if (chown(devname, ci->uid, ci->gid))
perror("chown");
if (chmod(devname, ci->mode))
perror("chmod");
if (stat(devname, &stb) < 0) {
pr_err("failed to stat %s\n",
devname);
return -1;
}
add_dev(devname, &stb, 0, NULL);
}
if (strcmp(chosen, devname) != 0) {
if (mkdir(DEV_NUM_PREF, 0700) == 0) {
if (chown(DEV_NUM_PREF, ci->uid, ci->gid))
perror("chown " DEV_NUM_PREF);
if (chmod(DEV_NUM_PREF, ci->mode | ((ci->mode >> 2) & 0111)))
perror("chmod " DEV_NUM_PREF);
}
if (dev && strcmp(chosen, dev) == 0)
/* We know we are allowed to use this name */
unlink(chosen);
if (lstat(chosen, &stb) == 0) {
char buf[300];
ssize_t link_len = readlink(chosen, buf, sizeof(buf)-1);
if (link_len >= 0)
buf[link_len] = '\0';
if ((stb.st_mode & S_IFMT) != S_IFLNK ||
link_len < 0 ||
strcmp(buf, devname) != 0) {
pr_err("%s exists - ignoring\n",
chosen);
strcpy(chosen, devname);
}
} else if (symlink(devname, chosen) != 0)
pr_err("failed to create %s: %s\n",
chosen, strerror(errno));
}
}
mdfd = open_dev_excl(devnm);
if (mdfd < 0)
pr_err("unexpected failure opening %s\n",
devname);
return mdfd;
}
/* Open this and check that it is an md device.
* On success, return filedescriptor.
* On failure, return -1 if it doesn't exist,
* or -2 if it exists but is not an md device.
*/
int open_mddev(char *dev, int report_errors)
{
int mdfd = open(dev, O_RDONLY);
if (mdfd < 0) {
if (report_errors)
pr_err("error opening %s: %s\n",
dev, strerror(errno));
return -1;
}
if (md_array_valid(mdfd) == 0) {
close(mdfd);
if (report_errors)
pr_err("%s does not appear to be an md device\n", dev);
return -2;
}
return mdfd;
}
/**
* is_mddev() - check that file name passed is an md device.
* @dev: file name that has to be checked.
* Return: 1 if file passed is an md device, 0 if not.
*/
int is_mddev(char *dev)
{
int fd = open_mddev(dev, 1);
if (fd >= 0) {
close(fd);
return 1;
}
return 0;
}