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 typedef unsigned int __attribute__((__may_alias__)) label_ints_t;
  50
  51 /*
  52  */
  53 int
  54 read_dasd_pt(int fd, struct slice all, struct slice *sp, int ns)
  55 {
  56         int retval = -1;
  57         int blocksize;
  58         uint64_t disksize;
  59         uint64_t offset, size, fmt_size;
  60         dasd_information_t info;
  61         struct hd_geometry geo;
  62         char type[5] = {0,};
  63         volume_label_t vlabel;
  64         unsigned char *data = NULL;
  65         uint64_t blk;
  66         int fd_dasd = -1;
  67         struct stat sbuf;
  68         dev_t dev;
  69         char *devname;
  70         char pathname[256];
  71
  72         if (fd < 0) {
  73                 return -1;
  74         }
  75
  76         if (fstat(fd, &sbuf) == -1) {
  77                 return -1;
  78         }
  79
  80         devname = dm_mapname(major(sbuf.st_rdev), minor(sbuf.st_rdev));
  81
  82         if (devname != NULL) {
  83                 /* We were passed a handle to a dm device.
  84                  * Get the first target and operate on that instead.
  85                  */
  86                 if (!(dev = dm_get_first_dep(devname))) {
  87                         free(devname);
  88                         return -1;
  89                 }
  90                 free(devname);
  91
  92                 if ((unsigned int)major(dev) != 94) {
  93                         /* Not a DASD */
  94                         return -1;
  95                 }
  96
  97                 /*
  98                  * Hard to believe, but there's no simple way to translate
  99                  * major/minor into an openable device file, so we have
 100                  * to create one for ourselves.
 101                  */
 102
 103                 sprintf(pathname, "/dev/.kpartx-node-%u-%u",
 104                         (unsigned int)major(dev), (unsigned int)minor(dev));
 105                 if ((fd_dasd = open(pathname, O_RDONLY)) == -1) {
 106                         /* Devicenode does not exist. Try to create one */
 107                         if (mknod(pathname, 0600 | S_IFBLK, dev) == -1) {
 108                                 /* Couldn't create a device node */
 109                                 return -1;
 110                         }
 111                         fd_dasd = open(pathname, O_RDONLY);
 112                         /*
 113                          * The file will vanish when the last process (we)
 114                          * has ceased to access it.
 115                          */
 116                         unlink(pathname);
 117                 }
 118                 if (!fd_dasd) {
 119                         /* Couldn't open the device */
 120                         return -1;
 121                 }
 122         } else {
 123                 fd_dasd = fd;
 124         }
 125
 126         if (ioctl(fd_dasd, BIODASDINFO, (unsigned long)&info) != 0) {
 127                 goto out;
 128         }
 129
 130         if (ioctl(fd_dasd, HDIO_GETGEO, (unsigned long)&geo) != 0) {
 131                 goto out;
 132         }
 133
 134         if (ioctl(fd_dasd, BLKGETSIZE64, &disksize) != 0)
 135                 goto out;
 136         disksize >>= 9;
 137
 138         if (ioctl(fd_dasd, BLKSSZGET, &blocksize) != 0)
 139                 goto out;
 140
 141         if (blocksize < 512 || blocksize > 4096)
 142                 goto out;
 143
 144         /*
 145          * Get volume label, extract name and type.
 146          */
 147
 148         if (!(data = (unsigned char *)malloc(blocksize)))
 149                 goto out;
 150
 151
 152         if (lseek(fd_dasd, info.label_block * blocksize, SEEK_SET) == -1)
 153                 goto out;
 154         if (read(fd_dasd, data, blocksize) == -1) {
 155                 perror("read");
 156                 goto out;
 157         }
 158
 159         if ((!info.FBA_layout) && (!strcmp(info.type, "ECKD")))
 160                 memcpy (&vlabel, data, sizeof(vlabel));
 161         else {
 162                 bzero(&vlabel,4);
 163                 memcpy (&vlabel.vollbl, data, sizeof(vlabel) - 4);
 164         }
 165         vtoc_ebcdic_dec(vlabel.vollbl, type, 4);
 166
 167         /*
 168          * Three different types: CMS1, VOL1 and LNX1/unlabeled
 169          */
 170         if (strncmp(type, "CMS1", 4) == 0) {
 171                 /*
 172                  * VM style CMS1 labeled disk
 173                  */
 174                 label_ints_t *label = (label_ints_t *) &vlabel;
 175
 176                 blocksize = label[4];
 177                 if (label[14] != 0) {
 178                         /* disk is reserved minidisk */
 179                         offset = label[14];
 180                         size   = sectors512(label[8] - 1, blocksize);
 181                 } else {
 182                         offset = info.label_block + 1;
 183                         size   = sectors512(label[8], blocksize);
 184                 }
 185                 sp[0].start = sectors512(offset, blocksize);
 186                 sp[0].size  = size - sp[0].start;
 187                 retval = 1;
 188         } else if ((strncmp(type, "VOL1", 4) == 0) &&
 189                 (!info.FBA_layout) && (!strcmp(info.type, "ECKD"))) {
 190                 /*
 191                  * New style VOL1 labeled disk
 192                  */
 193                 int counter;
 194
 195                 /* get block number and read then go through format1 labels */
 196                 blk = cchhb2blk(&vlabel.vtoc, &geo) + 1;
 197                 counter = 0;
 198                 if (lseek(fd_dasd, blk * blocksize, SEEK_SET) == -1)
 199                         goto out;
 200
 201                 while (read(fd_dasd, data, blocksize) != -1) {
 202                         format1_label_t f1;
 203
 204                         memcpy(&f1, data, sizeof(format1_label_t));
 205
 206                         /* skip FMT4 / FMT5 / FMT7 labels */
 207                         if (EBCtoASC[f1.DS1FMTID] == '4'
 208                             || EBCtoASC[f1.DS1FMTID] == '5'
 209                             || EBCtoASC[f1.DS1FMTID] == '7'
 210                             || EBCtoASC[f1.DS1FMTID] == '9') {
 211                                 blk++;
 212                                 continue;
 213                         }
 214
 215                         /* only FMT1 and FMT8 valid at this point */
 216                         if (EBCtoASC[f1.DS1FMTID] != '1' &&
 217                             EBCtoASC[f1.DS1FMTID] != '8')
 218                                 break;
 219
 220                         /* OK, we got valid partition data */
 221                         offset = cchh2blk(&f1.DS1EXT1.llimit, &geo);
 222                         size  = cchh2blk(&f1.DS1EXT1.ulimit, &geo) -
 223                                 offset + geo.sectors;
 224                         sp[counter].start = sectors512(offset, blocksize);
 225                         sp[counter].size  = sectors512(size, blocksize);
 226                         counter++;
 227                         blk++;
 228                 }
 229                 retval = counter;
 230         } else {
 231                 /*
 232                  * Old style LNX1 or unlabeled disk
 233                  */
 234                 if (strncmp(type, "LNX1", 4) == 0) {
 235                         if (vlabel.ldl_version == 0xf2) {
 236                                 fmt_size = sectors512(vlabel.formatted_blocks,
 237                                                       blocksize);
 238                         } else if (!strcmp(info.type, "ECKD")) {
 239                                 /* formated w/o large volume support */
 240                                 fmt_size = geo.cylinders * geo.heads
 241                                         * geo.sectors * (blocksize >> 9);
 242                         } else {
 243                                 /* old label and no usable disk geometry
 244                                  * (e.g. DIAG) */
 245                                 fmt_size = disksize;
 246                         }
 247                         size = disksize;
 248                         if (fmt_size < size)
 249                                 size = fmt_size;
 250                 } else
 251                         size = disksize;
 252
 253                 sp[0].start = sectors512(info.label_block + 1, blocksize);
 254                 sp[0].size  = size - sp[0].start;
 255                 retval = 1;
 256         }
 257
 258  out:
 259         if (data != NULL)
 260                 free(data);
 261         if (fd_dasd != -1 && fd_dasd != fd)
 262                 close(fd_dasd);
 263         return retval;
 264 }