mdadm/mdopen.c
Neil Brown 0df46c2ad8 Change MAJOR() etc to major() etc
This allows for larger device number if glibc supports
it (requires 2.3.3).
Also fail before creating larger device number if glibc
support isn't present.

Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au>
2005-04-04 05:16:13 +00:00

220 lines
6.1 KiB
C

/*
* mdadm - manage Linux "md" devices aka RAID arrays.
*
* Copyright (C) 2001-2002 Neil Brown <neilb@cse.unsw.edu.au>
*
*
* 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_parts(char *dev, int cnt)
{
/* 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;
char *name = malloc(strlen(dev) + 20);
int dig = isdigit(dev[strlen(dev)-1]);
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;
sprintf(name, "%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;
}
mknod(name, S_IFBLK | 0600, makedev(major, minor+i));
chown(name, stb2.st_uid, stb2.st_gid);
chmod(name, stb2.st_mode & 07777);
}
}
/*
* 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 is user=0, group=0 perm=0600
*/
int open_mddev(char *dev, int autof)
{
int mdfd;
struct stat stb;
int major = MD_MAJOR;
int minor;
int must_remove = 0;
struct mdstat_ent *mdlist;
int num;
if (autof) {
/* autof is set, so we need to check that the name is ok,
* and possibly create one if not
*/
stb.st_mode = 0;
if (lstat(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 */
if (autof>0)
major = get_mdp_major();
if (stb.st_mode && major(stb.st_rdev) != major)
must_remove = 1;
if (stb.st_mode && !must_remove) {
mdu_array_info_t array;
/* 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 (ioctl(mdfd, GET_ARRAY_INFO, &array)==0) {
/* already active */
must_remove = 1;
close(mdfd);
} else {
if (autof > 0)
make_parts(dev, autof);
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
*/
switch(is_standard(dev, &num)) {
case -1: /* non partitioned */
if (autof > 0) {
fprintf(stderr, Name ": that --auto option not compatable with device named %s\n", dev);
return -1;
}
minor = num;
num = -1-num;
break;
case 1: /* partitioned */
if (autof == -1) {
fprintf(stderr, Name ": that --auto option not compatable with device named %s\n", dev);
return -1;
}
minor = num << MdpMinorShift;
major = get_mdp_major();
break;
case 0: /* not standard, pick an unused number */
mdlist = mdstat_read(0);
for (num= (autof>0)?-1:0 ; ; num+= (autof>2)?-1:1) {
struct mdstat_ent *me;
for (me=mdlist; me; me=me->next)
if (me->devnum == num)
break;
if (!me) {
/* doesn't exist if mdstat.
* make sure it is new to /dev too
*/
char *dn;
if (autof > 0)
minor = (-1-num) << MdpMinorShift;
else
minor = num;
dn = map_dev(major,minor);
if (dn==NULL || is_standard(dn, NULL)) {
/* this number only used by a 'standard' name,
* so it is safe to use
*/
break;
}
}
}
}
/* 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 (mknod(dev, S_IFBLK|0600, makedev(major, minor))!= 0) {
fprintf(stderr, Name ": failed to create %s\n", dev);
return -1;
}
if (must_remove) {
chown(dev, stb.st_uid, stb.st_gid);
chmod(dev, stb.st_mode & 07777);
}
make_parts(dev,autof);
}
}
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;
}