kpartx/dasd.c

   1 /*
   2  * dasd.c
   3  *
   4  * IBM DASD partition table handling.
   5  *
   6  * Mostly taken from drivers/s390/block/dasd.c
   7  *
   8  * Copyright (c) 2005, Hannes Reinecke, SUSE Linux Products GmbH
   9  * Copyright IBM Corporation, 2009
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License
  13  * as published by the Free Software Foundation; either version 2
  14  * of the License, or (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
  24  * USA.
  25  */
  26
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29 #include <unistd.h>
  30 #include <inttypes.h>
  31 #include <sys/types.h>
  32 #include <sys/stat.h>
  33 #include <sys/ioctl.h>
  34 #include <linux/hdreg.h>
  35 #include <errno.h>
  36 #include <string.h>
  37 #include <fcntl.h>
  38 #include <libdevmapper.h>
  39 #include "devmapper.h"
  40 #include "kpartx.h"
  41 #include "byteorder.h"
  42 #include "dasd.h"
  43
  44 unsigned long long sectors512(unsigned long long sectors, int blocksize)
  45 {
  46         return sectors * (blocksize >> 9);
  47 }
  48
  49 /*
  50  */
  51 int
  52 read_dasd_pt(int fd, struct slice all, struct slice *sp, int ns)
  53 {
  54         int retval = -1;
  55         int blocksize;
  56         uint64_t disksize;
  57         uint64_t offset, size, fmt_size;
  58         dasd_information_t info;
  59         struct hd_geometry geo;
  60         char type[5] = {0,};
  61         volume_label_t vlabel;
  62         unsigned char *data = NULL;
  63         uint64_t blk;
  64         int fd_dasd = -1;
  65         struct stat sbuf;
  66         dev_t dev;
  67         char *devname;
  68         char pathname[256];
  69
  70         if (fd < 0) {
  71                 return -1;
  72         }
  73
  74         if (fstat(fd, &sbuf) == -1) {
  75                 return -1;
  76         }
  77
  78         devname = dm_mapname(major(sbuf.st_rdev), minor(sbuf.st_rdev));
  79
  80         if (devname != NULL) {
  81                 /* We were passed a handle to a dm device.
  82                  * Get the first target and operate on that instead.
  83                  */
  84                 if (!(dev = dm_get_first_dep(devname))) {
  85                         free(devname);
  86                         return -1;
  87                 }
  88                 free(devname);
  89
  90                 if ((unsigned int)major(dev) != 94) {
  91                         /* Not a DASD */
  92                         return -1;
  93                 }
  94
  95                 /*
  96                  * Hard to believe, but there's no simple way to translate
  97                  * major/minor into an openable device file, so we have
  98                  * to create one for ourselves.
  99                  */
 100
 101                 sprintf(pathname, "/dev/.kpartx-node-%u-%u",
 102                         (unsigned int)major(dev), (unsigned int)minor(dev));
 103                 if ((fd_dasd = open(pathname, O_RDONLY)) == -1) {
 104                         /* Devicenode does not exist. Try to create one */
 105                         if (mknod(pathname, 0600 | S_IFBLK, dev) == -1) {
 106                                 /* Couldn't create a device node */
 107                                 return -1;
 108                         }
 109                         fd_dasd = open(pathname, O_RDONLY);
 110                         /*
 111                          * The file will vanish when the last process (we)
 112                          * has ceased to access it.
 113                          */
 114                         unlink(pathname);
 115                 }
 116                 if (!fd_dasd) {
 117                         /* Couldn't open the device */
 118                         return -1;
 119                 }
 120         } else {
 121                 fd_dasd = fd;
 122         }
 123
 124         if (ioctl(fd_dasd, BIODASDINFO, (unsigned long)&info) != 0) {
 125                 goto out;
 126         }
 127
 128         if (ioctl(fd_dasd, HDIO_GETGEO, (unsigned long)&geo) != 0) {
 129                 goto out;
 130         }
 131
 132         if (ioctl(fd_dasd, BLKGETSIZE64, &disksize) != 0)
 133                 goto out;
 134         disksize >>= 9;
 135
 136         if (ioctl(fd_dasd, BLKSSZGET, &blocksize) != 0)
 137                 goto out;
 138
 139         if (blocksize < 512 || blocksize > 4096)
 140                 goto out;
 141
 142         /*
 143          * Get volume label, extract name and type.
 144          */
 145
 146         if (!(data = (unsigned char *)malloc(blocksize)))
 147                 goto out;
 148
 149
 150         if (lseek(fd_dasd, info.label_block * blocksize, SEEK_SET) == -1)
 151                 goto out;
 152         if (read(fd_dasd, data, blocksize) == -1) {
 153                 perror("read");
 154                 goto out;
 155         }
 156
 157         if ((!info.FBA_layout) && (!strcmp(info.type, "ECKD")))
 158                 memcpy (&vlabel, data, sizeof(vlabel));
 159         else {
 160                 bzero(&vlabel,4);
 161                 memcpy (&vlabel.vollbl, data, sizeof(vlabel) - 4);
 162         }
 163         vtoc_ebcdic_dec(vlabel.vollbl, type, 4);
 164
 165         /*
 166          * Three different types: CMS1, VOL1 and LNX1/unlabeled
 167          */
 168         if (strncmp(type, "CMS1", 4) == 0) {
 169                 /*
 170                  * VM style CMS1 labeled disk
 171                  */
 172                 unsigned int *label = (unsigned int *) &vlabel;
 173
 174                 blocksize = label[4];
 175                 if (label[14] != 0) {
 176                         /* disk is reserved minidisk */
 177                         offset = label[14];
 178                         size   = sectors512(label[8] - 1, blocksize);
 179                 } else {
 180                         offset = info.label_block + 1;
 181                         size   = sectors512(label[8], blocksize);
 182                 }
 183                 sp[0].start = sectors512(offset, blocksize);
 184                 sp[0].size  = size - sp[0].start;
 185                 retval = 1;
 186         } else if ((strncmp(type, "VOL1", 4) == 0) &&
 187                 (!info.FBA_layout) && (!strcmp(info.type, "ECKD"))) {
 188                 /*
 189                  * New style VOL1 labeled disk
 190                  */
 191                 int counter;
 192
 193                 /* get block number and read then go through format1 labels */
 194                 blk = cchhb2blk(&vlabel.vtoc, &geo) + 1;
 195                 counter = 0;
 196                 if (lseek(fd_dasd, blk * blocksize, SEEK_SET) == -1)
 197                         goto out;
 198
 199                 while (read(fd_dasd, data, blocksize) != -1) {
 200                         format1_label_t f1;
 201
 202                         memcpy(&f1, data, sizeof(format1_label_t));
 203
 204                         /* skip FMT4 / FMT5 / FMT7 labels */
 205                         if (EBCtoASC[f1.DS1FMTID] == '4'
 206                             || EBCtoASC[f1.DS1FMTID] == '5'
 207                             || EBCtoASC[f1.DS1FMTID] == '7'
 208                             || EBCtoASC[f1.DS1FMTID] == '9') {
 209                                 blk++;
 210                                 continue;
 211                         }
 212
 213                         /* only FMT1 and FMT8 valid at this point */
 214                         if (EBCtoASC[f1.DS1FMTID] != '1' &&
 215                             EBCtoASC[f1.DS1FMTID] != '8')
 216                                 break;
 217
 218                         /* OK, we got valid partition data */
 219                         offset = cchh2blk(&f1.DS1EXT1.llimit, &geo);
 220                         size  = cchh2blk(&f1.DS1EXT1.ulimit, &geo) -
 221                                 offset + geo.sectors;
 222                         sp[counter].start = sectors512(offset, blocksize);
 223                         sp[counter].size  = sectors512(size, blocksize);
 224                         counter++;
 225                         blk++;
 226                 }
 227                 retval = counter;
 228         } else {
 229                 /*
 230                  * Old style LNX1 or unlabeled disk
 231                  */
 232                 if (strncmp(type, "LNX1", 4) == 0) {
 233                         if (vlabel.ldl_version == 0xf2) {
 234                                 fmt_size = sectors512(vlabel.formatted_blocks,
 235                                                       blocksize);
 236                         } else if (!strcmp(info.type, "ECKD")) {
 237                                 /* formated w/o large volume support */
 238                                 fmt_size = geo.cylinders * geo.heads
 239                                         * geo.sectors * (blocksize >> 9);
 240                         } else {
 241                                 /* old label and no usable disk geometry
 242                                  * (e.g. DIAG) */
 243                                 fmt_size = disksize;
 244                         }
 245                         size = disksize;
 246                         if (fmt_size < size)
 247                                 size = fmt_size;
 248                 } else
 249                         size = disksize;
 250
 251                 sp[0].start = sectors512(info.label_block + 1, blocksize);
 252                 sp[0].size  = size - sp[0].start;
 253                 retval = 1;
 254         }
 255
 256  out:
 257         if (data != NULL)
 258                 free(data);
 259         if (fd_dasd != -1 && fd_dasd != fd)
 260                 close(fd_dasd);
 261         return retval;
 262 }