diff options
Diffstat (limited to 'mdopen.c')
| -rw-r--r-- | mdopen.c | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/mdopen.c b/mdopen.c new file mode 100644 index 0000000..69c4a23 --- /dev/null +++ b/mdopen.c @@ -0,0 +1,193 @@ +/* + * 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 == MKDEV(major, minor+i)) + continue; + unlink(name); + } else { + stb2 = stb; + } + mknod(name, S_IFBLK | 0600, MKDEV(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 few 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. + * Easiest to read /proc/mdstat, and hunt through for + * 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)) { + /* this number only used by a 'standard' name, + * so it is safe to use + */ + break; + } + } + } + /* 'num' is the number to use, >=0 for md, <0 for mdp */ + if (must_remove) { + /* never remove a device name that ends /mdNN or /dNN, + * that would be confusing + */ + if (is_standard(dev)) { + fprintf(stderr, Name ": --auto refusing to remove %s as it looks like a standard name.\n", + dev); + return -1; + } + unlink(dev); + } + + if (mknod(dev, S_IFBLK|0600, MKDEV(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; +} + |