external/gpl2/lvm2/dist/lib/device/device.c

   1 /*      $NetBSD$        */
   2
   3 /*
   4  * Copyright (C) 2001-2004 Sistina Software, Inc. All rights reserved.
   5  * Copyright (C) 2004-2007 Red Hat, Inc. All rights reserved.
   6  *
   7  * This file is part of LVM2.
   8  *
   9  * This copyrighted material is made available to anyone wishing to use,
  10  * modify, copy, or redistribute it subject to the terms and conditions
  11  * of the GNU Lesser General Public License v.2.1.
  12  *
  13  * You should have received a copy of the GNU Lesser General Public License
  14  * along with this program; if not, write to the Free Software Foundation,
  15  * Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  16  */
  17
  18 #include <libgen.h> /* dirname, basename */
  19 #include "lib.h"
  20 #include "lvm-types.h"
  21 #include "device.h"
  22 #include "metadata.h"
  23 #include "filter.h"
  24 #include "xlate.h"
  25
  26 /* See linux/genhd.h and fs/partitions/msdos */
  27
  28 #define PART_MAGIC 0xAA55
  29 #define PART_MAGIC_OFFSET UINT64_C(0x1FE)
  30 #define PART_OFFSET UINT64_C(0x1BE)
  31
  32 struct partition {
  33         uint8_t boot_ind;
  34         uint8_t head;
  35         uint8_t sector;
  36         uint8_t cyl;
  37         uint8_t sys_ind;        /* partition type */
  38         uint8_t end_head;
  39         uint8_t end_sector;
  40         uint8_t end_cyl;
  41         uint32_t start_sect;
  42         uint32_t nr_sects;
  43 } __attribute__((packed));
  44
  45 static int _is_partitionable(struct device *dev)
  46 {
  47         int parts = max_partitions(MAJOR(dev->dev));
  48
  49         /* All MD devices are partitionable via blkext (as of 2.6.28) */
  50         if (MAJOR(dev->dev) == md_major())
  51                 return 1;
  52
  53         if ((parts <= 1) || (MINOR(dev->dev) % parts))
  54                 return 0;
  55
  56         return 1;
  57 }
  58
  59 static int _has_partition_table(struct device *dev)
  60 {
  61         int ret = 0;
  62         unsigned p;
  63         uint16_t buf[SECTOR_SIZE/sizeof(uint16_t)];
  64         uint16_t *part_magic;
  65         struct partition *part;
  66
  67         if (!dev_open(dev)) {
  68                 stack;
  69                 return -1;
  70         }
  71
  72         if (!dev_read(dev, UINT64_C(0), sizeof(buf), &buf))
  73                 goto_out;
  74
  75         /* FIXME Check for other types of partition table too */
  76
  77         /* Check for msdos partition table */
  78         part_magic = buf + PART_MAGIC_OFFSET/sizeof(buf[0]);
  79         if ((*part_magic == xlate16(PART_MAGIC))) {
  80                 part = (struct partition *) (buf + PART_OFFSET/sizeof(buf[0]));
  81                 for (p = 0; p < 4; p++, part++) {
  82                         /* Table is invalid if boot indicator not 0 or 0x80 */
  83                         if ((part->boot_ind & 0x7f)) {
  84                                 ret = 0;
  85                                 break;
  86                         }
  87                         /* Must have at least one non-empty partition */
  88                         if (part->nr_sects)
  89                                 ret = 1;
  90                 }
  91         }
  92
  93       out:
  94         if (!dev_close(dev))
  95                 stack;
  96
  97         return ret;
  98 }
  99
 100 int is_partitioned_dev(struct device *dev)
 101 {
 102         if (!_is_partitionable(dev))
 103                 return 0;
 104
 105         return _has_partition_table(dev);
 106 }
 107
 108 #if 0
 109 #include <sys/stat.h>
 110 #include <sys/mman.h>
 111 #include <stdio.h>
 112 #include <unistd.h>
 113 #include <fcntl.h>
 114 #include <ctype.h>
 115
 116 #include <errno.h>
 117 #include <sys/ioctl.h>
 118 #include <linux/fs.h>
 119 #include <linux/major.h>
 120 #include <linux/genhd.h>
 121
 122 int _get_partition_type(struct dev_filter *filter, struct device *d);
 123
 124 #define MINOR_PART(dev) (MINOR((dev)->dev) % max_partitions(MINOR((dev)->dev)))
 125
 126 int is_extended_partition(struct device *d)
 127 {
 128         return (MINOR_PART(d) > 4) ? 1 : 0;
 129 }
 130
 131 struct device *dev_primary(struct dev_mgr *dm, struct device *d)
 132 {
 133         struct device *ret;
 134
 135         ret = dev_by_dev(dm, d->dev - MINOR_PART(dm, d));
 136         /* FIXME: Needs replacing with a 'refresh' */
 137         if (!ret) {
 138                 init_dev_scan(dm);
 139                 ret = dev_by_dev(dm, d->dev - MINOR_PART(dm, d));
 140         }
 141
 142         return ret;
 143
 144 }
 145
 146 int partition_type_is_lvm(struct dev_mgr *dm, struct device *d)
 147 {
 148         int pt;
 149
 150         pt = _get_partition_type(dm, d);
 151
 152         if (!pt) {
 153                 if (is_whole_disk(dm, d))
 154                         /* FIXME: Overloaded pt=0 in error cases */
 155                         return 1;
 156                 else {
 157                         log_error
 158                             ("%s: missing partition table "
 159                              "on partitioned device", d->name);
 160                         return 0;
 161                 }
 162         }
 163
 164         if (is_whole_disk(dm, d)) {
 165                 log_error("%s: looks to possess partition table", d->name);
 166                 return 0;
 167         }
 168
 169         /* check part type */
 170         if (pt != LVM_PARTITION && pt != LVM_NEW_PARTITION) {
 171                 log_error("%s: invalid partition type 0x%x "
 172                           "(must be 0x%x)", d->name, pt, LVM_NEW_PARTITION);
 173                 return 0;
 174         }
 175
 176         if (pt == LVM_PARTITION) {
 177                 log_error
 178                     ("%s: old LVM partition type found - please change to 0x%x",
 179                      d->name, LVM_NEW_PARTITION);
 180                 return 0;
 181         }
 182
 183         return 1;
 184 }
 185
 186 int _get_partition_type(struct dev_mgr *dm, struct device *d)
 187 {
 188         int pv_handle = -1;
 189         struct device *primary;
 190         ssize_t read_ret;
 191         ssize_t bytes_read = 0;
 192         char *buffer;
 193         unsigned short *s_buffer;
 194         struct partition *part;
 195         loff_t offset = 0;
 196         loff_t extended_offset = 0;
 197         int part_sought;
 198         int part_found = 0;
 199         int first_partition = 1;
 200         int extended_partition = 0;
 201         int p;
 202
 203         if (!(primary = dev_primary(dm, d))) {
 204                 log_error
 205                     ("Failed to find main device containing partition %s",
 206                      d->name);
 207                 return 0;
 208         }
 209
 210         if (!(buffer = dm_malloc(SECTOR_SIZE))) {
 211                 log_error("Failed to allocate partition table buffer");
 212                 return 0;
 213         }
 214
 215         /* Get partition table */
 216         if ((pv_handle = open(primary->name, O_RDONLY)) < 0) {
 217                 log_error("%s: open failed: %s", primary->name,
 218                           strerror(errno));
 219                 return 0;
 220         }
 221
 222         s_buffer = (unsigned short *) buffer;
 223         part = (struct partition *) (buffer + 0x1be);
 224         part_sought = MINOR_PART(dm, d);
 225
 226         do {
 227                 bytes_read = 0;
 228
 229                 if (llseek(pv_handle, offset * SECTOR_SIZE, SEEK_SET) == -1) {
 230                         log_error("%s: llseek failed: %s",
 231                                   primary->name, strerror(errno));
 232                         return 0;
 233                 }
 234
 235                 while ((bytes_read < SECTOR_SIZE) &&
 236                        (read_ret =
 237                         read(pv_handle, buffer + bytes_read,
 238                              SECTOR_SIZE - bytes_read)) != -1)
 239                         bytes_read += read_ret;
 240
 241                 if (read_ret == -1) {
 242                         log_error("%s: read failed: %s", primary->name,
 243                                   strerror(errno));
 244                         return 0;
 245                 }
 246
 247                 if (s_buffer[255] == 0xAA55) {
 248                         if (is_whole_disk(dm, d))
 249                                 return -1;
 250                 } else
 251                         return 0;
 252
 253                 extended_partition = 0;
 254
 255                 /* Loop through primary partitions */
 256                 for (p = 0; p < 4; p++) {
 257                         if (part[p].sys_ind == DOS_EXTENDED_PARTITION ||
 258                             part[p].sys_ind == LINUX_EXTENDED_PARTITION
 259                             || part[p].sys_ind == WIN98_EXTENDED_PARTITION) {
 260                                 extended_partition = 1;
 261                                 offset = extended_offset + part[p].start_sect;
 262                                 if (extended_offset == 0)
 263                                         extended_offset = part[p].start_sect;
 264                                 if (first_partition == 1)
 265                                         part_found++;
 266                         } else if (first_partition == 1) {
 267                                 if (p == part_sought) {
 268                                         if (part[p].sys_ind == 0) {
 269                                                 /* missing primary? */
 270                                                 return 0;
 271                                         }
 272                                 } else
 273                                         part_found++;
 274                         } else if (!part[p].sys_ind)
 275                                 part_found++;
 276
 277                         if (part_sought == part_found)
 278                                 return part[p].sys_ind;
 279
 280                 }
 281                 first_partition = 0;
 282         }
 283         while (extended_partition == 1);
 284
 285         return 0;
 286 }
 287 #endif
 288
 289 #ifdef linux
 290
 291 int get_primary_dev(const char *sysfs_dir,
 292                     struct device *dev, dev_t *result)
 293 {
 294         char path[PATH_MAX+1];
 295         char temp_path[PATH_MAX+1];
 296         char buffer[64];
 297         struct stat info;
 298         FILE *fp;
 299         uint32_t pri_maj, pri_min;
 300         int ret = 0;
 301
 302         /* check if dev is a partition */
 303         if (dm_snprintf(path, PATH_MAX, "%s/dev/block/%d:%d/partition",
 304                         sysfs_dir, (int)MAJOR(dev->dev), (int)MINOR(dev->dev)) < 0) {
 305                 log_error("dm_snprintf partition failed");
 306                 return ret;
 307         }
 308
 309         if (stat(path, &info) == -1) {
 310                 if (errno != ENOENT)
 311                         log_sys_error("stat", path);
 312                 return ret;
 313         }
 314
 315         /*
 316          * extract parent's path from the partition's symlink, e.g.:
 317          * - readlink /sys/dev/block/259:0 = ../../block/md0/md0p1
 318          * - dirname ../../block/md0/md0p1 = ../../block/md0
 319          * - basename ../../block/md0/md0  = md0
 320          * Parent's 'dev' sysfs attribute  = /sys/block/md0/dev
 321          */
 322         if (readlink(dirname(path), temp_path, PATH_MAX) < 0) {
 323                 log_sys_error("readlink", path);
 324                 return ret;
 325         }
 326
 327         if (dm_snprintf(path, PATH_MAX, "%s/block/%s/dev",
 328                         sysfs_dir, basename(dirname(temp_path))) < 0) {
 329                 log_error("dm_snprintf dev failed");
 330                 return ret;
 331         }
 332
 333         /* finally, parse 'dev' attribute and create corresponding dev_t */
 334         if (stat(path, &info) == -1) {
 335                 if (errno == ENOENT)
 336                         log_error("sysfs file %s does not exist", path);
 337                 else
 338                         log_sys_error("stat", path);
 339                 return ret;
 340         }
 341
 342         fp = fopen(path, "r");
 343         if (!fp) {
 344                 log_sys_error("fopen", path);
 345                 return ret;
 346         }
 347
 348         if (!fgets(buffer, sizeof(buffer), fp)) {
 349                 log_sys_error("fgets", path);
 350                 goto out;
 351         }
 352
 353         if (sscanf(buffer, "%d:%d", &pri_maj, &pri_min) != 2) {
 354                 log_error("sysfs file %s not in expected MAJ:MIN format: %s",
 355                           path, buffer);
 356                 goto out;
 357         }
 358         *result = MKDEV(pri_maj, pri_min);
 359         ret = 1;
 360
 361 out:
 362         if (fclose(fp))
 363                 log_sys_error("fclose", path);
 364
 365         return ret;
 366 }
 367
 368 static unsigned long _dev_topology_attribute(const char *attribute,
 369                                              const char *sysfs_dir,
 370                                              struct device *dev)
 371 {
 372         const char *sysfs_fmt_str = "%s/dev/block/%d:%d/%s";
 373         char path[PATH_MAX+1], buffer[64];
 374         FILE *fp;
 375         struct stat info;
 376         dev_t uninitialized_var(primary);
 377         unsigned long result = 0UL;
 378
 379         if (!attribute || !*attribute)
 380                 return_0;
 381
 382         if (!sysfs_dir || !*sysfs_dir)
 383                 return_0;
 384
 385         if (dm_snprintf(path, PATH_MAX, sysfs_fmt_str, sysfs_dir,
 386                         (int)MAJOR(dev->dev), (int)MINOR(dev->dev),
 387                         attribute) < 0) {
 388                 log_error("dm_snprintf %s failed", attribute);
 389                 return 0;
 390         }
 391
 392         /*
 393          * check if the desired sysfs attribute exists
 394          * - if not: either the kernel doesn't have topology support
 395          *   or the device could be a partition
 396          */
 397         if (stat(path, &info) == -1) {
 398                 if (errno != ENOENT) {
 399                         log_sys_error("stat", path);
 400                         return 0;
 401                 }
 402                 if (!get_primary_dev(sysfs_dir, dev, &primary))
 403                         return 0;
 404
 405                 /* get attribute from partition's primary device */
 406                 if (dm_snprintf(path, PATH_MAX, sysfs_fmt_str, sysfs_dir,
 407                                 (int)MAJOR(primary), (int)MINOR(primary),
 408                                 attribute) < 0) {
 409                         log_error("primary dm_snprintf %s failed", attribute);
 410                         return 0;
 411                 }
 412                 if (stat(path, &info) == -1) {
 413                         if (errno != ENOENT)
 414                                 log_sys_error("stat", path);
 415                         return 0;
 416                 }
 417         }
 418
 419         if (!(fp = fopen(path, "r"))) {
 420                 log_sys_error("fopen", path);
 421                 return 0;
 422         }
 423
 424         if (!fgets(buffer, sizeof(buffer), fp)) {
 425                 log_sys_error("fgets", path);
 426                 goto out;
 427         }
 428
 429         if (sscanf(buffer, "%lu", &result) != 1) {
 430                 log_error("sysfs file %s not in expected format: %s", path,
 431                           buffer);
 432                 goto out;
 433         }
 434
 435         log_very_verbose("Device %s %s is %lu bytes.",
 436                          dev_name(dev), attribute, result);
 437
 438 out:
 439         if (fclose(fp))
 440                 log_sys_error("fclose", path);
 441
 442         return result >> SECTOR_SHIFT;
 443 }
 444
 445 unsigned long dev_alignment_offset(const char *sysfs_dir,
 446                                    struct device *dev)
 447 {
 448         return _dev_topology_attribute("alignment_offset",
 449                                        sysfs_dir, dev);
 450 }
 451
 452 unsigned long dev_minimum_io_size(const char *sysfs_dir,
 453                                   struct device *dev)
 454 {
 455         return _dev_topology_attribute("queue/minimum_io_size",
 456                                        sysfs_dir, dev);
 457 }
 458
 459 unsigned long dev_optimal_io_size(const char *sysfs_dir,
 460                                   struct device *dev)
 461 {
 462         return _dev_topology_attribute("queue/optimal_io_size",
 463                                        sysfs_dir, dev);
 464 }
 465
 466 #else
 467
 468 int get_primary_dev(const char *sysfs_dir,
 469                     struct device *dev, dev_t *result)
 470 {
 471         return 0;
 472 }
 473
 474 unsigned long dev_alignment_offset(const char *sysfs_dir,
 475                                    struct device *dev)
 476 {
 477         return 0UL;
 478 }
 479
 480 unsigned long dev_minimum_io_size(const char *sysfs_dir,
 481                                   struct device *dev)
 482 {
 483         return 0UL;
 484 }
 485
 486 unsigned long dev_optimal_io_size(const char *sysfs_dir,
 487                                   struct device *dev)
 488 {
 489         return 0UL;
 490 }
 491
 492 #endif