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  * Magic records per track calculation, copied from fdasd.c
  51  */
  52 static unsigned int ceil_quot(unsigned int d1, unsigned int d2)
  53 {
  54         return (d1 + (d2 - 1)) / d2;
  55 }
  56
  57 unsigned int recs_per_track(unsigned int dl)
  58 {
  59         int dn = ceil_quot(dl + 6, 232) + 1;
  60         return 1729 / (10 + 9 + ceil_quot(dl + 6 * dn, 34));
  61 }
  62
  63
  64 typedef unsigned int __attribute__((__may_alias__)) label_ints_t;
  65
  66 /*
  67  */
  68 int
  69 read_dasd_pt(int fd, struct slice all, struct slice *sp, int ns)
  70 {
  71         int retval = -1;
  72         int blocksize;
  73         uint64_t disksize;
  74         uint64_t offset, size, fmt_size;
  75         dasd_information_t info;
  76         struct hd_geometry geo;
  77         char type[5] = {0,};
  78         volume_label_t vlabel;
  79         unsigned char *data = NULL;
  80         uint64_t blk;
  81         int fd_dasd = -1;
  82         struct stat sbuf;
  83         dev_t dev;
  84         char *devname;
  85         char pathname[256];
  86
  87         if (fd < 0) {
  88                 return -1;
  89         }
  90
  91         if (fstat(fd, &sbuf) == -1) {
  92                 return -1;
  93         }
  94
  95         devname = dm_mapname(major(sbuf.st_rdev), minor(sbuf.st_rdev));
  96
  97         if (devname != NULL) {
  98                 /* We were passed a handle to a dm device.
  99                  * Get the first target and operate on that instead.
 100                  */
 101                 if (!(dev = dm_get_first_dep(devname))) {
 102                         free(devname);
 103                         return -1;
 104                 }
 105                 free(devname);
 106
 107                 if ((unsigned int)major(dev) != 94) {
 108                         /* Not a DASD */
 109                         return -1;
 110                 }
 111
 112                 /*
 113                  * Hard to believe, but there's no simple way to translate
 114                  * major/minor into an openable device file, so we have
 115                  * to create one for ourselves.
 116                  */
 117
 118                 sprintf(pathname, "/dev/.kpartx-node-%u-%u",
 119                         (unsigned int)major(dev), (unsigned int)minor(dev));
 120                 if ((fd_dasd = open(pathname, O_RDONLY)) == -1) {
 121                         /* Devicenode does not exist. Try to create one */
 122                         if (mknod(pathname, 0600 | S_IFBLK, dev) == -1) {
 123                                 /* Couldn't create a device node */
 124                                 return -1;
 125                         }
 126                         fd_dasd = open(pathname, O_RDONLY);
 127                         /*
 128                          * The file will vanish when the last process (we)
 129                          * has ceased to access it.
 130                          */
 131                         unlink(pathname);
 132                 }
 133                 if (!fd_dasd) {
 134                         /* Couldn't open the device */
 135                         return -1;
 136                 }
 137         } else {
 138                 fd_dasd = fd;
 139         }
 140
 141         if (ioctl(fd_dasd, BIODASDINFO, (unsigned long)&info) != 0) {
 142                 info.label_block = 2;
 143                 info.FBA_layout = 0;
 144                 memcpy(info.type, "ECKD", sizeof(info.type));
 145         }
 146
 147         if (ioctl(fd_dasd, BLKSSZGET, &blocksize) != 0)
 148                 goto out;
 149
 150         if (ioctl(fd_dasd, BLKGETSIZE64, &disksize) != 0)
 151                 goto out;
 152
 153         if (ioctl(fd_dasd, HDIO_GETGEO, (unsigned long)&geo) != 0) {
 154                 unsigned int cyl;
 155
 156                 geo.heads = 15;
 157                 geo.sectors = recs_per_track(blocksize);
 158                 cyl = disksize / (blocksize * geo.heads * geo.sectors);
 159                 if (cyl < LV_COMPAT_CYL)
 160                         geo.cylinders = cyl;
 161                 else
 162                         geo.cylinders = LV_COMPAT_CYL;
 163                 geo.start = 0;
 164         }
 165
 166         disksize >>= 9;
 167
 168         if (blocksize < 512 || blocksize > 4096)
 169                 goto out;
 170
 171         /*
 172          * Get volume label, extract name and type.
 173          */
 174
 175         if (!(data = (unsigned char *)malloc(blocksize)))
 176                 goto out;
 177
 178
 179         if (lseek(fd_dasd, info.label_block * blocksize, SEEK_SET) == -1)
 180                 goto out;
 181         if (read(fd_dasd, data, blocksize) == -1) {
 182                 perror("read");
 183                 goto out;
 184         }
 185
 186         if ((!info.FBA_layout) && (!strcmp(info.type, "ECKD")))
 187                 memcpy (&vlabel, data, sizeof(vlabel));
 188         else {
 189                 bzero(&vlabel,4);
 190                 memcpy (&vlabel.vollbl, data, sizeof(vlabel) - 4);
 191         }
 192         vtoc_ebcdic_dec(vlabel.vollbl, type, 4);
 193
 194         /*
 195          * Three different types: CMS1, VOL1 and LNX1/unlabeled
 196          */
 197         if (strncmp(type, "CMS1", 4) == 0) {
 198                 /*
 199                  * VM style CMS1 labeled disk
 200                  */
 201                 label_ints_t *label = (label_ints_t *) &vlabel;
 202
 203                 blocksize = label[4];
 204                 if (label[14] != 0) {
 205                         /* disk is reserved minidisk */
 206                         offset = label[14];
 207                         size   = sectors512(label[8] - 1, blocksize);
 208                 } else {
 209                         offset = info.label_block + 1;
 210                         size   = sectors512(label[8], blocksize);
 211                 }
 212                 sp[0].start = sectors512(offset, blocksize);
 213                 sp[0].size  = size - sp[0].start;
 214                 retval = 1;
 215         } else if ((strncmp(type, "VOL1", 4) == 0) &&
 216                 (!info.FBA_layout) && (!strcmp(info.type, "ECKD"))) {
 217                 /*
 218                  * New style VOL1 labeled disk
 219                  */
 220                 int counter;
 221
 222                 /* get block number and read then go through format1 labels */
 223                 blk = cchhb2blk(&vlabel.vtoc, &geo) + 1;
 224                 counter = 0;
 225                 if (lseek(fd_dasd, blk * blocksize, SEEK_SET) == -1)
 226                         goto out;
 227
 228                 while (read(fd_dasd, data, blocksize) != -1) {
 229                         format1_label_t f1;
 230
 231                         memcpy(&f1, data, sizeof(format1_label_t));
 232
 233                         /* skip FMT4 / FMT5 / FMT7 labels */
 234                         if (EBCtoASC[f1.DS1FMTID] == '4'
 235                             || EBCtoASC[f1.DS1FMTID] == '5'
 236                             || EBCtoASC[f1.DS1FMTID] == '7'
 237                             || EBCtoASC[f1.DS1FMTID] == '9') {
 238                                 blk++;
 239                                 continue;
 240                         }
 241
 242                         /* only FMT1 and FMT8 valid at this point */
 243                         if (EBCtoASC[f1.DS1FMTID] != '1' &&
 244                             EBCtoASC[f1.DS1FMTID] != '8')
 245                                 break;
 246
 247                         /* OK, we got valid partition data */
 248                         offset = cchh2blk(&f1.DS1EXT1.llimit, &geo);
 249                         size  = cchh2blk(&f1.DS1EXT1.ulimit, &geo) -
 250                                 offset + geo.sectors;
 251                         sp[counter].start = sectors512(offset, blocksize);
 252                         sp[counter].size  = sectors512(size, blocksize);
 253                         counter++;
 254                         blk++;
 255                 }
 256                 retval = counter;
 257         } else {
 258                 /*
 259                  * Old style LNX1 or unlabeled disk
 260                  */
 261                 if (strncmp(type, "LNX1", 4) == 0) {
 262                         if (vlabel.ldl_version == 0xf2) {
 263                                 fmt_size = sectors512(vlabel.formatted_blocks,
 264                                                       blocksize);
 265                         } else if (!strcmp(info.type, "ECKD")) {
 266                                 /* formated w/o large volume support */
 267                                 fmt_size = geo.cylinders * geo.heads
 268                                         * geo.sectors * (blocksize >> 9);
 269                         } else {
 270                                 /* old label and no usable disk geometry
 271                                  * (e.g. DIAG) */
 272                                 fmt_size = disksize;
 273                         }
 274                         size = disksize;
 275                         if (fmt_size < size)
 276                                 size = fmt_size;
 277                 } else
 278                         size = disksize;
 279
 280                 sp[0].start = sectors512(info.label_block + 1, blocksize);
 281                 sp[0].size  = size - sp[0].start;
 282                 retval = 1;
 283         }
 284
 285  out:
 286         if (data != NULL)
 287                 free(data);
 288         if (fd_dasd != -1 && fd_dasd != fd)
 289                 close(fd_dasd);
 290         return retval;
 291 }