bigbiff | 7b4c7a6 | 2015-01-01 19:44:14 -0500 | [diff] [blame^] | 1 | |
| 2 | #ifdef HAVE_LIBBLKID |
| 3 | #include <blkid.h> |
| 4 | #endif |
| 5 | #include "blkdev.h" |
| 6 | |
| 7 | #include "fdiskP.h" |
| 8 | |
| 9 | /** |
| 10 | * SECTION: alignment |
| 11 | * @title: Alignment |
| 12 | * @short_description: functions to align partitions and work with disk topology and geometry |
| 13 | * |
| 14 | * The libfdisk aligns the end of the partitions to make it possible to align |
| 15 | * the next partition to the "grain" (see fdisk_get_grain()). The grain is |
| 16 | * usually 1MiB (or more for devices where optimal I/O is greater than 1MiB). |
| 17 | * |
| 18 | * It means that the library does not align strictly to physical sector size |
| 19 | * (or minimal or optimal I/O), but it uses greater granularity. It makes |
| 20 | * partition tables more portable. If you copy disk layout from 512-sector to |
| 21 | * 4K-sector device, all partitions are still aligned to physical sectors. |
| 22 | * |
| 23 | * This unified concept also makes partition tables more user friendly, all |
| 24 | * tables look same, LBA of the first partition is 2048 sectors everywhere, etc. |
| 25 | * |
| 26 | * It's recommended to not change any alignment or device properties. All is |
| 27 | * initialized by default by fdisk_assign_device(). |
| 28 | * |
| 29 | * Note that terminology used by libfdisk is: |
| 30 | * - device properties: I/O limits (topology), geometry, sector size, ... |
| 31 | * - alignment: first, last LBA, grain, ... |
| 32 | * |
| 33 | * The alignment setting may be modified by disk label driver. |
| 34 | */ |
| 35 | |
| 36 | /* |
| 37 | * Alignment according to logical granularity (usually 1MiB) |
| 38 | */ |
| 39 | static int lba_is_aligned(struct fdisk_context *cxt, fdisk_sector_t lba) |
| 40 | { |
| 41 | unsigned long granularity = max(cxt->phy_sector_size, cxt->min_io_size); |
| 42 | uintmax_t offset; |
| 43 | |
| 44 | if (cxt->grain > granularity) |
| 45 | granularity = cxt->grain; |
| 46 | offset = (lba * cxt->sector_size) & (granularity - 1); |
| 47 | |
| 48 | return !((granularity + cxt->alignment_offset - offset) & (granularity - 1)); |
| 49 | } |
| 50 | |
| 51 | /* |
| 52 | * Alignment according to physical device topology (usually minimal i/o size) |
| 53 | */ |
| 54 | static int lba_is_phy_aligned(struct fdisk_context *cxt, fdisk_sector_t lba) |
| 55 | { |
| 56 | unsigned long granularity = max(cxt->phy_sector_size, cxt->min_io_size); |
| 57 | uintmax_t offset = (lba * cxt->sector_size) & (granularity - 1); |
| 58 | |
| 59 | return !((granularity + cxt->alignment_offset - offset) & (granularity - 1)); |
| 60 | } |
| 61 | |
| 62 | /** |
| 63 | * fdisk_align_lba: |
| 64 | * @cxt: context |
| 65 | * @lba: address to align |
| 66 | * @direction: FDISK_ALIGN_{UP,DOWN,NEAREST} |
| 67 | * |
| 68 | * This function aligns @lba to the "grain" (see fdisk_get_grain()). If the |
| 69 | * device uses alignment offset then the result is moved according the offset |
| 70 | * to be on the physical boundary. |
| 71 | * |
| 72 | * Returns: alignment LBA. |
| 73 | */ |
| 74 | fdisk_sector_t fdisk_align_lba(struct fdisk_context *cxt, fdisk_sector_t lba, int direction) |
| 75 | { |
| 76 | fdisk_sector_t res; |
| 77 | |
| 78 | if (lba_is_aligned(cxt, lba)) |
| 79 | res = lba; |
| 80 | else { |
| 81 | fdisk_sector_t sects_in_phy = cxt->grain / cxt->sector_size; |
| 82 | |
| 83 | if (lba < cxt->first_lba) |
| 84 | res = cxt->first_lba; |
| 85 | |
| 86 | else if (direction == FDISK_ALIGN_UP) |
| 87 | res = ((lba + sects_in_phy) / sects_in_phy) * sects_in_phy; |
| 88 | |
| 89 | else if (direction == FDISK_ALIGN_DOWN) |
| 90 | res = (lba / sects_in_phy) * sects_in_phy; |
| 91 | |
| 92 | else /* FDISK_ALIGN_NEAREST */ |
| 93 | res = ((lba + sects_in_phy / 2) / sects_in_phy) * sects_in_phy; |
| 94 | |
| 95 | if (cxt->alignment_offset && !lba_is_aligned(cxt, res) && |
| 96 | res > cxt->alignment_offset / cxt->sector_size) { |
| 97 | /* |
| 98 | * apply alignment_offset |
| 99 | * |
| 100 | * On disk with alignment compensation physical blocks starts |
| 101 | * at LBA < 0 (usually LBA -1). It means we have to move LBA |
| 102 | * according the offset to be on the physical boundary. |
| 103 | */ |
| 104 | /* fprintf(stderr, "LBA: %llu apply alignment_offset\n", res); */ |
| 105 | res -= (max(cxt->phy_sector_size, cxt->min_io_size) - |
| 106 | cxt->alignment_offset) / cxt->sector_size; |
| 107 | |
| 108 | if (direction == FDISK_ALIGN_UP && res < lba) |
| 109 | res += sects_in_phy; |
| 110 | } |
| 111 | } |
| 112 | |
| 113 | if (lba != res) |
| 114 | DBG(CXT, ul_debugobj(cxt, "LBA %ju -aligned-to-> %ju", |
| 115 | (uintmax_t) lba, |
| 116 | (uintmax_t) res)); |
| 117 | return res; |
| 118 | } |
| 119 | |
| 120 | /** |
| 121 | * fdisk_align_lba_in_range: |
| 122 | * @cxt: context |
| 123 | * @lba: LBA |
| 124 | * @start: range start |
| 125 | * @stop: range stop |
| 126 | * |
| 127 | * Align @lba, the result has to be between @start and @stop |
| 128 | * |
| 129 | * Returns: aligned LBA |
| 130 | */ |
| 131 | fdisk_sector_t fdisk_align_lba_in_range(struct fdisk_context *cxt, |
| 132 | fdisk_sector_t lba, fdisk_sector_t start, fdisk_sector_t stop) |
| 133 | { |
| 134 | fdisk_sector_t res; |
| 135 | |
| 136 | start = fdisk_align_lba(cxt, start, FDISK_ALIGN_UP); |
| 137 | stop = fdisk_align_lba(cxt, stop, FDISK_ALIGN_DOWN); |
| 138 | lba = fdisk_align_lba(cxt, lba, FDISK_ALIGN_NEAREST); |
| 139 | |
| 140 | if (lba < start) |
| 141 | res = start; |
| 142 | else if (lba > stop) |
| 143 | res = stop; |
| 144 | else |
| 145 | res = lba; |
| 146 | |
| 147 | DBG(CXT, ul_debugobj(cxt, "LBA %ju range:<%ju..%ju>, result: %ju", |
| 148 | (uintmax_t) lba, |
| 149 | (uintmax_t) start, |
| 150 | (uintmax_t) stop, |
| 151 | (uintmax_t) res)); |
| 152 | return res; |
| 153 | } |
| 154 | |
| 155 | /** |
| 156 | * fdisk_lba_is_phy_aligned: |
| 157 | * @cxt: context |
| 158 | * @lba: LBA to check |
| 159 | * |
| 160 | * Check if the @lba is aligned to physical sector boundary. |
| 161 | * |
| 162 | * Returns: 1 if aligned. |
| 163 | */ |
| 164 | int fdisk_lba_is_phy_aligned(struct fdisk_context *cxt, fdisk_sector_t lba) |
| 165 | { |
| 166 | return lba_is_phy_aligned(cxt, lba); |
| 167 | } |
| 168 | |
| 169 | static unsigned long get_sector_size(int fd) |
| 170 | { |
| 171 | int sect_sz; |
| 172 | |
| 173 | if (!blkdev_get_sector_size(fd, §_sz)) |
| 174 | return (unsigned long) sect_sz; |
| 175 | return DEFAULT_SECTOR_SIZE; |
| 176 | } |
| 177 | |
| 178 | static void recount_geometry(struct fdisk_context *cxt) |
| 179 | { |
| 180 | if (!cxt->geom.heads) |
| 181 | cxt->geom.heads = 255; |
| 182 | if (!cxt->geom.sectors) |
| 183 | cxt->geom.sectors = 63; |
| 184 | |
| 185 | cxt->geom.cylinders = cxt->total_sectors / |
| 186 | (cxt->geom.heads * cxt->geom.sectors); |
| 187 | } |
| 188 | |
| 189 | /** |
| 190 | * fdisk_override_geometry: |
| 191 | * @cxt: fdisk context |
| 192 | * @cylinders: user specified cylinders |
| 193 | * @heads: user specified heads |
| 194 | * @sectors: user specified sectors |
| 195 | * |
| 196 | * Overrides auto-discovery. The function fdisk_reset_device_properties() |
| 197 | * restores the original setting. |
| 198 | * |
| 199 | * The difference between fdisk_override_geometry() and fdisk_save_user_geometry() |
| 200 | * is that saved user geometry is persistent setting and it's applied always |
| 201 | * when device is assigned to the context or device properties are reseted. |
| 202 | * |
| 203 | * Returns: 0 on success, < 0 on error. |
| 204 | */ |
| 205 | int fdisk_override_geometry(struct fdisk_context *cxt, |
| 206 | unsigned int cylinders, |
| 207 | unsigned int heads, |
| 208 | unsigned int sectors) |
| 209 | { |
| 210 | if (!cxt) |
| 211 | return -EINVAL; |
| 212 | if (heads) |
| 213 | cxt->geom.heads = heads; |
| 214 | if (sectors) |
| 215 | cxt->geom.sectors = sectors; |
| 216 | |
| 217 | if (cylinders) |
| 218 | cxt->geom.cylinders = cylinders; |
| 219 | else |
| 220 | recount_geometry(cxt); |
| 221 | |
| 222 | fdisk_reset_alignment(cxt); |
| 223 | |
| 224 | DBG(CXT, ul_debugobj(cxt, "override C/H/S: %u/%u/%u", |
| 225 | (unsigned) cxt->geom.cylinders, |
| 226 | (unsigned) cxt->geom.heads, |
| 227 | (unsigned) cxt->geom.sectors)); |
| 228 | |
| 229 | return 0; |
| 230 | } |
| 231 | |
| 232 | /** |
| 233 | * fdisk_save_user_geometry: |
| 234 | * @cxt: context |
| 235 | * @cylinders: C |
| 236 | * @heads: H |
| 237 | * @sectors: S |
| 238 | * |
| 239 | * Save user defined geometry to use it for partitioning. |
| 240 | * |
| 241 | * The user properties are applied by fdisk_assign_device() or |
| 242 | * fdisk_reset_device_properties(). |
| 243 | |
| 244 | * Returns: <0 on error, 0 on success. |
| 245 | */ |
| 246 | int fdisk_save_user_geometry(struct fdisk_context *cxt, |
| 247 | unsigned int cylinders, |
| 248 | unsigned int heads, |
| 249 | unsigned int sectors) |
| 250 | { |
| 251 | if (!cxt) |
| 252 | return -EINVAL; |
| 253 | |
| 254 | if (heads) |
| 255 | cxt->user_geom.heads = heads > 256 ? 0 : heads; |
| 256 | if (sectors) |
| 257 | cxt->user_geom.sectors = sectors >= 64 ? 0 : sectors; |
| 258 | if (cylinders) |
| 259 | cxt->user_geom.cylinders = cylinders; |
| 260 | |
| 261 | DBG(CXT, ul_debugobj(cxt, "user C/H/S: %u/%u/%u", |
| 262 | (unsigned) cxt->user_geom.cylinders, |
| 263 | (unsigned) cxt->user_geom.heads, |
| 264 | (unsigned) cxt->user_geom.sectors)); |
| 265 | |
| 266 | return 0; |
| 267 | } |
| 268 | |
| 269 | /** |
| 270 | * fdisk_save_user_sector_size: |
| 271 | * @cxt: context |
| 272 | * @phy: physical sector size |
| 273 | * @log: logicla sector size |
| 274 | * |
| 275 | * Save user defined sector sizes to use it for partitioning. |
| 276 | * |
| 277 | * The user properties are applied by fdisk_assign_device() or |
| 278 | * fdisk_reset_device_properties(). |
| 279 | * |
| 280 | * Returns: <0 on error, 0 on success. |
| 281 | */ |
| 282 | int fdisk_save_user_sector_size(struct fdisk_context *cxt, |
| 283 | unsigned int phy, |
| 284 | unsigned int log) |
| 285 | { |
| 286 | if (!cxt) |
| 287 | return -EINVAL; |
| 288 | |
| 289 | DBG(CXT, ul_debugobj(cxt, "user phy/log sector size: %u/%u", phy, log)); |
| 290 | |
| 291 | cxt->user_pyh_sector = phy; |
| 292 | cxt->user_log_sector = log; |
| 293 | |
| 294 | return 0; |
| 295 | } |
| 296 | |
| 297 | /** |
| 298 | * fdisk_has_user_device_properties: |
| 299 | * @cxt: context |
| 300 | * |
| 301 | * Returns: 1 if user specified any properties |
| 302 | */ |
| 303 | int fdisk_has_user_device_properties(struct fdisk_context *cxt) |
| 304 | { |
| 305 | return (cxt->user_pyh_sector |
| 306 | || cxt->user_log_sector |
| 307 | || cxt->user_geom.heads |
| 308 | || cxt->user_geom.sectors |
| 309 | || cxt->user_geom.cylinders); |
| 310 | } |
| 311 | |
| 312 | int fdisk_apply_user_device_properties(struct fdisk_context *cxt) |
| 313 | { |
| 314 | if (!cxt) |
| 315 | return -EINVAL; |
| 316 | |
| 317 | DBG(CXT, ul_debugobj(cxt, "appling user device properties")); |
| 318 | |
| 319 | if (cxt->user_pyh_sector) |
| 320 | cxt->phy_sector_size = cxt->user_pyh_sector; |
| 321 | if (cxt->user_log_sector) |
| 322 | cxt->sector_size = cxt->min_io_size = |
| 323 | cxt->io_size = cxt->user_log_sector; |
| 324 | |
| 325 | if (cxt->user_geom.heads) |
| 326 | cxt->geom.heads = cxt->user_geom.heads; |
| 327 | if (cxt->user_geom.sectors) |
| 328 | cxt->geom.sectors = cxt->user_geom.sectors; |
| 329 | |
| 330 | if (cxt->user_geom.cylinders) |
| 331 | cxt->geom.cylinders = cxt->user_geom.cylinders; |
| 332 | else if (cxt->user_geom.heads || cxt->user_geom.sectors) |
| 333 | recount_geometry(cxt); |
| 334 | |
| 335 | fdisk_reset_alignment(cxt); |
| 336 | if (cxt->firstsector_bufsz != cxt->sector_size) |
| 337 | fdisk_read_firstsector(cxt); |
| 338 | |
| 339 | DBG(CXT, ul_debugobj(cxt, "new C/H/S: %u/%u/%u", |
| 340 | (unsigned) cxt->geom.cylinders, |
| 341 | (unsigned) cxt->geom.heads, |
| 342 | (unsigned) cxt->geom.sectors)); |
| 343 | DBG(CXT, ul_debugobj(cxt, "new log/phy sector size: %u/%u", |
| 344 | (unsigned) cxt->sector_size, |
| 345 | (unsigned) cxt->phy_sector_size)); |
| 346 | |
| 347 | return 0; |
| 348 | } |
| 349 | |
| 350 | void fdisk_zeroize_device_properties(struct fdisk_context *cxt) |
| 351 | { |
| 352 | assert(cxt); |
| 353 | |
| 354 | cxt->io_size = 0; |
| 355 | cxt->optimal_io_size = 0; |
| 356 | cxt->min_io_size = 0; |
| 357 | cxt->phy_sector_size = 0; |
| 358 | cxt->sector_size = 0; |
| 359 | cxt->alignment_offset = 0; |
| 360 | cxt->grain = 0; |
| 361 | cxt->first_lba = 0; |
| 362 | cxt->last_lba = 0; |
| 363 | cxt->total_sectors = 0; |
| 364 | |
| 365 | memset(&cxt->geom, 0, sizeof(struct fdisk_geometry)); |
| 366 | } |
| 367 | |
| 368 | /** |
| 369 | * fdisk_reset_device_properties: |
| 370 | * @cxt: context |
| 371 | * |
| 372 | * Resets and discovery topology (I/O limits), geometry, re-read the first |
| 373 | * rector on the device if necessary and apply user device setting (geometry |
| 374 | * and sector size), then initialize alignment according to label driver (see |
| 375 | * fdisk_reset_alignment()). |
| 376 | * |
| 377 | * You don't have to use this function by default, fdisk_assign_device() is |
| 378 | * smart enough to initialize all necessary setting. |
| 379 | * |
| 380 | * Returns: 0 on success, <0 on error. |
| 381 | */ |
| 382 | int fdisk_reset_device_properties(struct fdisk_context *cxt) |
| 383 | { |
| 384 | int rc; |
| 385 | |
| 386 | if (!cxt) |
| 387 | return -EINVAL; |
| 388 | |
| 389 | DBG(CXT, ul_debugobj(cxt, "*** reseting device properties")); |
| 390 | |
| 391 | fdisk_zeroize_device_properties(cxt); |
| 392 | fdisk_discover_topology(cxt); |
| 393 | fdisk_discover_geometry(cxt); |
| 394 | |
| 395 | rc = fdisk_read_firstsector(cxt); |
| 396 | if (rc) |
| 397 | return rc; |
| 398 | |
| 399 | fdisk_apply_user_device_properties(cxt); |
| 400 | return 0; |
| 401 | } |
| 402 | |
| 403 | /* |
| 404 | * Generic (label independent) geometry |
| 405 | */ |
| 406 | int fdisk_discover_geometry(struct fdisk_context *cxt) |
| 407 | { |
| 408 | fdisk_sector_t nsects; |
| 409 | |
| 410 | assert(cxt); |
| 411 | assert(cxt->geom.heads == 0); |
| 412 | |
| 413 | DBG(CXT, ul_debugobj(cxt, "%s: discovering geometry...", cxt->dev_path)); |
| 414 | |
| 415 | /* get number of 512-byte sectors, and convert it the real sectors */ |
| 416 | if (!blkdev_get_sectors(cxt->dev_fd, (unsigned long long *) &nsects)) |
| 417 | cxt->total_sectors = (nsects / (cxt->sector_size >> 9)); |
| 418 | |
| 419 | DBG(CXT, ul_debugobj(cxt, "total sectors: %ju (ioctl=%ju)", |
| 420 | (uintmax_t) cxt->total_sectors, |
| 421 | (uintmax_t) nsects)); |
| 422 | |
| 423 | /* what the kernel/bios thinks the geometry is */ |
| 424 | blkdev_get_geometry(cxt->dev_fd, &cxt->geom.heads, (unsigned int *) &cxt->geom.sectors); |
| 425 | |
| 426 | /* obtained heads and sectors */ |
| 427 | recount_geometry(cxt); |
| 428 | |
| 429 | DBG(CXT, ul_debugobj(cxt, "result: C/H/S: %u/%u/%u", |
| 430 | (unsigned) cxt->geom.cylinders, |
| 431 | (unsigned) cxt->geom.heads, |
| 432 | (unsigned) cxt->geom.sectors)); |
| 433 | return 0; |
| 434 | } |
| 435 | |
| 436 | int fdisk_discover_topology(struct fdisk_context *cxt) |
| 437 | { |
| 438 | #ifdef HAVE_LIBBLKID |
| 439 | blkid_probe pr; |
| 440 | #endif |
| 441 | assert(cxt); |
| 442 | assert(cxt->sector_size == 0); |
| 443 | |
| 444 | DBG(CXT, ul_debugobj(cxt, "%s: discovering topology...", cxt->dev_path)); |
| 445 | #ifdef HAVE_LIBBLKID |
| 446 | DBG(CXT, ul_debugobj(cxt, "initialize libblkid prober")); |
| 447 | |
| 448 | pr = blkid_new_probe(); |
| 449 | if (pr && blkid_probe_set_device(pr, cxt->dev_fd, 0, 0) == 0) { |
| 450 | blkid_topology tp = blkid_probe_get_topology(pr); |
| 451 | |
| 452 | if (tp) { |
| 453 | cxt->min_io_size = blkid_topology_get_minimum_io_size(tp); |
| 454 | cxt->optimal_io_size = blkid_topology_get_optimal_io_size(tp); |
| 455 | cxt->phy_sector_size = blkid_topology_get_physical_sector_size(tp); |
| 456 | cxt->alignment_offset = blkid_topology_get_alignment_offset(tp); |
| 457 | |
| 458 | /* I/O size used by fdisk */ |
| 459 | cxt->io_size = cxt->optimal_io_size; |
| 460 | if (!cxt->io_size) |
| 461 | /* optimal IO is optional, default to minimum IO */ |
| 462 | cxt->io_size = cxt->min_io_size; |
| 463 | } |
| 464 | } |
| 465 | blkid_free_probe(pr); |
| 466 | #endif |
| 467 | |
| 468 | cxt->sector_size = get_sector_size(cxt->dev_fd); |
| 469 | if (!cxt->phy_sector_size) /* could not discover physical size */ |
| 470 | cxt->phy_sector_size = cxt->sector_size; |
| 471 | |
| 472 | /* no blkid or error, use default values */ |
| 473 | if (!cxt->min_io_size) |
| 474 | cxt->min_io_size = cxt->sector_size; |
| 475 | if (!cxt->io_size) |
| 476 | cxt->io_size = cxt->sector_size; |
| 477 | |
| 478 | DBG(CXT, ul_debugobj(cxt, "result: log/phy sector size: %ld/%ld", |
| 479 | cxt->sector_size, cxt->phy_sector_size)); |
| 480 | DBG(CXT, ul_debugobj(cxt, "result: fdisk/min/optimal io: %ld/%ld/%ld", |
| 481 | cxt->io_size, cxt->optimal_io_size, cxt->min_io_size)); |
| 482 | return 0; |
| 483 | } |
| 484 | |
| 485 | static int has_topology(struct fdisk_context *cxt) |
| 486 | { |
| 487 | /* |
| 488 | * Assume that the device provides topology info if |
| 489 | * optimal_io_size is set or alignment_offset is set or |
| 490 | * minimum_io_size is not power of 2. |
| 491 | */ |
| 492 | if (cxt && |
| 493 | (cxt->optimal_io_size || |
| 494 | cxt->alignment_offset || |
| 495 | !is_power_of_2(cxt->min_io_size))) |
| 496 | return 1; |
| 497 | return 0; |
| 498 | } |
| 499 | |
| 500 | /* |
| 501 | * The LBA of the first partition is based on the device geometry and topology. |
| 502 | * This offset is generic (and recommended) for all labels. |
| 503 | * |
| 504 | * Returns: 0 on error or number of logical sectors. |
| 505 | */ |
| 506 | static fdisk_sector_t topology_get_first_lba(struct fdisk_context *cxt) |
| 507 | { |
| 508 | fdisk_sector_t x = 0, res; |
| 509 | |
| 510 | if (!cxt) |
| 511 | return 0; |
| 512 | |
| 513 | if (!cxt->io_size) |
| 514 | fdisk_discover_topology(cxt); |
| 515 | |
| 516 | /* |
| 517 | * Align the begin of partitions to: |
| 518 | * |
| 519 | * a) topology |
| 520 | * a2) alignment offset |
| 521 | * a1) or physical sector (minimal_io_size, aka "grain") |
| 522 | * |
| 523 | * b) or default to 1MiB (2048 sectrors, Windows Vista default) |
| 524 | * |
| 525 | * c) or for very small devices use 1 phy.sector |
| 526 | */ |
| 527 | if (has_topology(cxt)) { |
| 528 | if (cxt->alignment_offset) |
| 529 | x = cxt->alignment_offset; |
| 530 | else if (cxt->io_size > 2048 * 512) |
| 531 | x = cxt->io_size; |
| 532 | } |
| 533 | /* default to 1MiB */ |
| 534 | if (!x) |
| 535 | x = 2048 * 512; |
| 536 | |
| 537 | res = x / cxt->sector_size; |
| 538 | |
| 539 | /* don't use huge offset on small devices */ |
| 540 | if (cxt->total_sectors <= res * 4) |
| 541 | res = cxt->phy_sector_size / cxt->sector_size; |
| 542 | |
| 543 | return res; |
| 544 | } |
| 545 | |
| 546 | static unsigned long topology_get_grain(struct fdisk_context *cxt) |
| 547 | { |
| 548 | unsigned long res; |
| 549 | |
| 550 | if (!cxt) |
| 551 | return 0; |
| 552 | |
| 553 | if (!cxt->io_size) |
| 554 | fdisk_discover_topology(cxt); |
| 555 | |
| 556 | res = cxt->io_size; |
| 557 | |
| 558 | /* use 1MiB grain always when possible */ |
| 559 | if (res < 2048 * 512) |
| 560 | res = 2048 * 512; |
| 561 | |
| 562 | /* don't use huge grain on small devices */ |
| 563 | if (cxt->total_sectors <= (res * 4 / cxt->sector_size)) |
| 564 | res = cxt->phy_sector_size; |
| 565 | |
| 566 | return res; |
| 567 | } |
| 568 | |
| 569 | /** |
| 570 | * fdisk_reset_alignment: |
| 571 | * @cxt: fdisk context |
| 572 | * |
| 573 | * Resets alignment setting to the default and label specific values. This |
| 574 | * function does not change device properties (I/O limits, geometry etc.). |
| 575 | * |
| 576 | * Returns: 0 on success, < 0 in case of error. |
| 577 | */ |
| 578 | int fdisk_reset_alignment(struct fdisk_context *cxt) |
| 579 | { |
| 580 | int rc = 0; |
| 581 | |
| 582 | if (!cxt) |
| 583 | return -EINVAL; |
| 584 | |
| 585 | DBG(CXT, ul_debugobj(cxt, "reseting alignment...")); |
| 586 | |
| 587 | /* default */ |
| 588 | cxt->grain = topology_get_grain(cxt); |
| 589 | cxt->first_lba = topology_get_first_lba(cxt); |
| 590 | cxt->last_lba = cxt->total_sectors - 1; |
| 591 | |
| 592 | /* overwrite default by label stuff */ |
| 593 | if (cxt->label && cxt->label->op->reset_alignment) |
| 594 | rc = cxt->label->op->reset_alignment(cxt); |
| 595 | |
| 596 | DBG(CXT, ul_debugobj(cxt, "alignment reseted to: " |
| 597 | "first LBA=%ju, last LBA=%ju, grain=%lu [rc=%d]", |
| 598 | (uintmax_t) cxt->first_lba, (uintmax_t) cxt->last_lba, |
| 599 | cxt->grain, rc)); |
| 600 | return rc; |
| 601 | } |
| 602 | |
| 603 | |
| 604 | fdisk_sector_t fdisk_scround(struct fdisk_context *cxt, fdisk_sector_t num) |
| 605 | { |
| 606 | fdisk_sector_t un = fdisk_get_units_per_sector(cxt); |
| 607 | return (num + un - 1) / un; |
| 608 | } |
| 609 | |
| 610 | fdisk_sector_t fdisk_cround(struct fdisk_context *cxt, fdisk_sector_t num) |
| 611 | { |
| 612 | return fdisk_use_cylinders(cxt) ? |
| 613 | (num / fdisk_get_units_per_sector(cxt)) + 1 : num; |
| 614 | } |
| 615 | |
| 616 | /** |
| 617 | * fdisk_reread_partition_table: |
| 618 | * @cxt: context |
| 619 | * |
| 620 | * Force *kernel* to re-read partition table on block devices. |
| 621 | * |
| 622 | * Returns: 0 on success, < 0 in case of error. |
| 623 | */ |
| 624 | int fdisk_reread_partition_table(struct fdisk_context *cxt) |
| 625 | { |
| 626 | int i; |
| 627 | struct stat statbuf; |
| 628 | |
| 629 | assert(cxt); |
| 630 | assert(cxt->dev_fd >= 0); |
| 631 | |
| 632 | i = fstat(cxt->dev_fd, &statbuf); |
| 633 | if (i == 0 && S_ISBLK(statbuf.st_mode)) { |
| 634 | sync(); |
| 635 | #ifdef BLKRRPART |
| 636 | fdisk_info(cxt, _("Calling ioctl() to re-read partition table.")); |
| 637 | i = ioctl(cxt->dev_fd, BLKRRPART); |
| 638 | #else |
| 639 | errno = ENOSYS; |
| 640 | i = 1; |
| 641 | #endif |
| 642 | } |
| 643 | |
| 644 | if (i) { |
| 645 | fdisk_warn(cxt, _("Re-reading the partition table failed.")); |
| 646 | fdisk_info(cxt, _( |
| 647 | "The kernel still uses the old table. The " |
| 648 | "new table will be used at the next reboot " |
| 649 | "or after you run partprobe(8) or kpartx(8).")); |
| 650 | return -errno; |
| 651 | } |
| 652 | |
| 653 | return 0; |
| 654 | } |