1/************************************************************ 2 * EFI GUID Partition Table handling 3 * Per Intel EFI Specification v1.02 4 * http://developer.intel.com/technology/efi/efi.htm 5 * efi.[ch] by Matt Domsch <Matt_Domsch@dell.com> 6 * Copyright 2000,2001,2002 Dell Computer Corporation 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation; either version 2 of the License, or 11 * (at your option) any later version. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 * 18 * You should have received a copy of the GNU General Public License 19 * along with this program; if not, write to the Free Software 20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 21 * 22 * 23 * TODO: 24 * 25 * Changelog: 26 * Wed Mar 27 2002 Matt Domsch <Matt_Domsch@dell.com> 27 * - Ported to 2.5.7-pre1 and 2.4.18 28 * - Applied patch to avoid fault in alternate header handling 29 * - cleaned up find_valid_gpt 30 * - On-disk structure and copy in memory is *always* LE now - 31 * swab fields as needed 32 * - remove print_gpt_header() 33 * - only use first max_p partition entries, to keep the kernel minor number 34 * and partition numbers tied. 35 * - 2.4.18 patch needs own crc32() function - there's no official 36 * lib/crc32.c in 2.4.x. 37 * 38 * Mon Feb 04 2002 Matt Domsch <Matt_Domsch@dell.com> 39 * - Removed __PRIPTR_PREFIX - not being used 40 * 41 * Mon Jan 14 2002 Matt Domsch <Matt_Domsch@dell.com> 42 * - Ported to 2.5.2-pre11 + library crc32 patch Linus applied 43 * 44 * Thu Dec 6 2001 Matt Domsch <Matt_Domsch@dell.com> 45 * - Added compare_gpts(). 46 * - moved le_efi_guid_to_cpus() back into this file. GPT is the only 47 * thing that keeps EFI GUIDs on disk. 48 * - Changed gpt structure names and members to be simpler and more Linux-like. 49 * 50 * Wed Oct 17 2001 Matt Domsch <Matt_Domsch@dell.com> 51 * - Removed CONFIG_DEVFS_VOLUMES_UUID code entirely per Martin Wilck 52 * 53 * Wed Oct 10 2001 Matt Domsch <Matt_Domsch@dell.com> 54 * - Changed function comments to DocBook style per Andreas Dilger suggestion. 55 * 56 * Mon Oct 08 2001 Matt Domsch <Matt_Domsch@dell.com> 57 * - Change read_lba() to use the page cache per Al Viro's work. 58 * - print u64s properly on all architectures 59 * - fixed debug_printk(), now Dprintk() 60 * 61 * Mon Oct 01 2001 Matt Domsch <Matt_Domsch@dell.com> 62 * - Style cleanups 63 * - made most functions static 64 * - Endianness addition 65 * - remove test for second alternate header, as it's not per spec, 66 * and is unnecessary. There's now a method to read/write the last 67 * sector of an odd-sized disk from user space. No tools have ever 68 * been released which used this code, so it's effectively dead. 69 * - Per Asit Mallick of Intel, added a test for a valid PMBR. 70 * - Added kernel command line option 'gpt' to override valid PMBR test. 71 * 72 * Wed Jun 6 2001 Martin Wilck <Martin.Wilck@Fujitsu-Siemens.com> 73 * - added devfs volume UUID support (/dev/volumes/uuids) for 74 * mounting file systems by the partition GUID. 75 * 76 * Tue Dec 5 2000 Matt Domsch <Matt_Domsch@dell.com> 77 * - Moved crc32() to linux/lib, added efi_crc32(). 78 * 79 * Thu Nov 30 2000 Matt Domsch <Matt_Domsch@dell.com> 80 * - Replaced Intel's CRC32 function with an equivalent 81 * non-license-restricted version. 82 * 83 * Wed Oct 25 2000 Matt Domsch <Matt_Domsch@dell.com> 84 * - Fixed the last_lba() call to return the proper last block 85 * 86 * Thu Oct 12 2000 Matt Domsch <Matt_Domsch@dell.com> 87 * - Thanks to Andries Brouwer for his debugging assistance. 88 * - Code works, detects all the partitions. 89 * 90 ************************************************************/ 91#include <linux/config.h> 92#include <linux/fs.h> 93#include <linux/genhd.h> 94#include <linux/kernel.h> 95#include <linux/major.h> 96#include <linux/string.h> 97#include <linux/blk.h> 98#include <linux/blkpg.h> 99#include <linux/slab.h> 100#include <linux/smp_lock.h> 101#include <linux/init.h> 102#include <asm/system.h> 103#include <asm/byteorder.h> 104#include "check.h" 105#include "efi.h" 106 107#if CONFIG_BLK_DEV_MD 108extern void md_autodetect_dev(kdev_t dev); 109#endif 110 111/* Handle printing of 64-bit values */ 112/* Borrowed from /usr/include/inttypes.h */ 113# if BITS_PER_LONG == 64 114# define __PRI64_PREFIX "l" 115# else 116# define __PRI64_PREFIX "ll" 117# endif 118# define PRIx64 __PRI64_PREFIX "x" 119 120 121#undef EFI_DEBUG 122#ifdef EFI_DEBUG 123#define Dprintk(x...) printk(KERN_DEBUG x) 124#else 125#define Dprintk(x...) 126#endif 127 128/* This allows a kernel command line option 'gpt' to override 129 * the test for invalid PMBR. Not __initdata because reloading 130 * the partition tables happens after init too. 131 */ 132static int force_gpt; 133static int __init 134force_gpt_fn(char *str) 135{ 136 force_gpt = 1; 137 return 1; 138} 139__setup("gpt", force_gpt_fn); 140 141 142/* 143 * There are multiple 16-bit CRC polynomials in common use, but this is 144 * *the* standard CRC-32 polynomial, first popularized by Ethernet. 145 * x^32+x^26+x^23+x^22+x^16+x^12+x^11+x^10+x^8+x^7+x^5+x^4+x^2+x^1+x^0 146 */ 147#define CRCPOLY_LE 0xedb88320 148/* How many bits at a time to use. Requires a table of 4<<CRC_xx_BITS bytes. */ 149/* For less performance-sensitive, use 4 */ 150#define CRC_LE_BITS 8 151static u32 *crc32table_le; 152 153/** 154 * crc32init_le() - allocate and initialize LE table data 155 * 156 * crc is the crc of the byte i; other entries are filled in based on the 157 * fact that crctable[i^j] = crctable[i] ^ crctable[j]. 158 * 159 */ 160static int __init crc32init_le(void) 161{ 162 unsigned i, j; 163 u32 crc = 1; 164 165 crc32table_le = 166 kmalloc((1 << CRC_LE_BITS) * sizeof(u32), GFP_KERNEL); 167 if (!crc32table_le) 168 return 1; 169 crc32table_le[0] = 0; 170 171 for (i = 1 << (CRC_LE_BITS - 1); i; i >>= 1) { 172 crc = (crc >> 1) ^ ((crc & 1) ? CRCPOLY_LE : 0); 173 for (j = 0; j < 1 << CRC_LE_BITS; j += 2 * i) 174 crc32table_le[i + j] = crc ^ crc32table_le[j]; 175 } 176 return 0; 177} 178 179/** 180 * crc32cleanup_le(): free LE table data 181 */ 182static void __exit crc32cleanup_le(void) 183{ 184 if (crc32table_le) kfree(crc32table_le); 185 crc32table_le = NULL; 186} 187 188__initcall(crc32init_le); 189__exitcall(crc32cleanup_le); 190 191/** 192 * crc32_le() - Calculate bitwise little-endian Ethernet AUTODIN II CRC32 193 * @crc - seed value for computation. ~0 for Ethernet, sometimes 0 for 194 * other uses, or the previous crc32 value if computing incrementally. 195 * @p - pointer to buffer over which CRC is run 196 * @len - length of buffer @p 197 * 198 */ 199static u32 crc32_le(u32 crc, unsigned char const *p, size_t len) 200{ 201 while (len--) { 202 crc = (crc >> 8) ^ crc32table_le[(crc ^ *p++) & 255]; 203 } 204 return crc; 205} 206 207 208/** 209 * efi_crc32() - EFI version of crc32 function 210 * @buf: buffer to calculate crc32 of 211 * @len - length of buf 212 * 213 * Description: Returns EFI-style CRC32 value for @buf 214 * 215 * This function uses the little endian Ethernet polynomial 216 * but seeds the function with ~0, and xor's with ~0 at the end. 217 * Note, the EFI Specification, v1.02, has a reference to 218 * Dr. Dobbs Journal, May 1994 (actually it's in May 1992). 219 */ 220static inline u32 221efi_crc32(const void *buf, unsigned long len) 222{ 223 return (crc32_le(~0L, buf, len) ^ ~0L); 224} 225 226/** 227 * is_pmbr_valid(): test Protective MBR for validity 228 * @mbr: pointer to a legacy mbr structure 229 * 230 * Description: Returns 1 if PMBR is valid, 0 otherwise. 231 * Validity depends on two things: 232 * 1) MSDOS signature is in the last two bytes of the MBR 233 * 2) One partition of type 0xEE is found 234 */ 235static int 236is_pmbr_valid(legacy_mbr *mbr) 237{ 238 int i, found = 0, signature = 0; 239 if (!mbr) 240 return 0; 241 signature = (le16_to_cpu(mbr->signature) == MSDOS_MBR_SIGNATURE); 242 for (i = 0; signature && i < 4; i++) { 243 if (mbr->partition_record[i].sys_ind == 244 EFI_PMBR_OSTYPE_EFI_GPT) { 245 found = 1; 246 break; 247 } 248 } 249 return (signature && found); 250} 251 252/** 253 * last_lba(): return number of last logical block of device 254 * @hd: gendisk with partition list 255 * @bdev: block device 256 * 257 * Description: Returns last LBA value on success, 0 on error. 258 * This is stored (by sd and ide-geometry) in 259 * the part[0] entry for this disk, and is the number of 260 * physical sectors available on the disk. 261 */ 262static u64 263last_lba(struct gendisk *hd, struct block_device *bdev) 264{ 265 if (!hd || !hd->part || !bdev) 266 return 0; 267 return hd->part[MINOR(to_kdev_t(bdev->bd_dev))].nr_sects - 1; 268} 269 270/** 271 * read_lba(): Read bytes from disk, starting at given LBA 272 * @hd 273 * @bdev 274 * @lba 275 * @buffer 276 * @size_t 277 * 278 * Description: Reads @count bytes from @bdev into @buffer. 279 * Returns number of bytes read on success, 0 on error. 280 */ 281static size_t 282read_lba(struct gendisk *hd, struct block_device *bdev, u64 lba, 283 u8 * buffer, size_t count) 284{ 285 286 size_t totalreadcount = 0, bytesread = 0; 287 unsigned long blocksize; 288 int i; 289 Sector sect; 290 unsigned char *data = NULL; 291 292 if (!hd || !bdev || !buffer || !count) 293 return 0; 294 295 blocksize = get_hardsect_size(to_kdev_t(bdev->bd_dev)); 296 if (!blocksize) 297 blocksize = 512; 298 299 for (i = 0; count > 0; i++) { 300 data = read_dev_sector(bdev, lba, §); 301 if (!data) 302 return totalreadcount; 303 304 bytesread = 305 PAGE_CACHE_SIZE - (data - 306 (unsigned char *) page_address(sect.v)); 307 bytesread = min(bytesread, count); 308 memcpy(buffer, data, bytesread); 309 put_dev_sector(sect); 310 311 buffer += bytesread; 312 totalreadcount += bytesread; 313 count -= bytesread; 314 lba += (bytesread / blocksize); 315 } 316 return totalreadcount; 317} 318 319 320/** 321 * alloc_read_gpt_entries(): reads partition entries from disk 322 * @hd 323 * @bdev 324 * @gpt - GPT header 325 * 326 * Description: Returns ptes on success, NULL on error. 327 * Allocates space for PTEs based on information found in @gpt. 328 * Notes: remember to free pte when you're done! 329 */ 330static gpt_entry * 331alloc_read_gpt_entries(struct gendisk *hd, 332 struct block_device *bdev, gpt_header *gpt) 333{ 334 size_t count; 335 gpt_entry *pte; 336 if (!hd || !bdev || !gpt) 337 return NULL; 338 339 count = le32_to_cpu(gpt->num_partition_entries) * 340 le32_to_cpu(gpt->sizeof_partition_entry); 341 if (!count) 342 return NULL; 343 pte = kmalloc(count, GFP_KERNEL); 344 if (!pte) 345 return NULL; 346 memset(pte, 0, count); 347 348 if (read_lba(hd, bdev, le64_to_cpu(gpt->partition_entry_lba), 349 (u8 *) pte, 350 count) < count) { 351 kfree(pte); 352 pte=NULL; 353 return NULL; 354 } 355 return pte; 356} 357 358/** 359 * alloc_read_gpt_header(): Allocates GPT header, reads into it from disk 360 * @hd 361 * @bdev 362 * @lba is the Logical Block Address of the partition table 363 * 364 * Description: returns GPT header on success, NULL on error. Allocates 365 * and fills a GPT header starting at @ from @bdev. 366 * Note: remember to free gpt when finished with it. 367 */ 368static gpt_header * 369alloc_read_gpt_header(struct gendisk *hd, struct block_device *bdev, u64 lba) 370{ 371 gpt_header *gpt; 372 if (!hd || !bdev) 373 return NULL; 374 375 gpt = kmalloc(sizeof (gpt_header), GFP_KERNEL); 376 if (!gpt) 377 return NULL; 378 memset(gpt, 0, sizeof (gpt_header)); 379 380 if (read_lba(hd, bdev, lba, (u8 *) gpt, 381 sizeof (gpt_header)) < sizeof (gpt_header)) { 382 kfree(gpt); 383 gpt=NULL; 384 return NULL; 385 } 386 387 return gpt; 388} 389 390/** 391 * is_gpt_valid() - tests one GPT header and PTEs for validity 392 * @hd 393 * @bdev 394 * @lba is the logical block address of the GPT header to test 395 * @gpt is a GPT header ptr, filled on return. 396 * @ptes is a PTEs ptr, filled on return. 397 * 398 * Description: returns 1 if valid, 0 on error. 399 * If valid, returns pointers to newly allocated GPT header and PTEs. 400 */ 401static int 402is_gpt_valid(struct gendisk *hd, struct block_device *bdev, u64 lba, 403 gpt_header **gpt, gpt_entry **ptes) 404{ 405 u32 crc, origcrc; 406 407 if (!hd || !bdev || !gpt || !ptes) 408 return 0; 409 if (!(*gpt = alloc_read_gpt_header(hd, bdev, lba))) 410 return 0; 411 412 /* Check the GUID Partition Table signature */ 413 if (le64_to_cpu((*gpt)->signature) != GPT_HEADER_SIGNATURE) { 414 Dprintk("GUID Partition Table Header signature is wrong: %" 415 PRIx64 " != %" PRIx64 "\n", le64_to_cpu((*gpt)->signature), 416 GPT_HEADER_SIGNATURE); 417 kfree(*gpt); 418 *gpt = NULL; 419 return 0; 420 } 421 422 /* Check the GUID Partition Table CRC */ 423 origcrc = le32_to_cpu((*gpt)->header_crc32); 424 (*gpt)->header_crc32 = 0; 425 crc = efi_crc32((const unsigned char *) (*gpt), le32_to_cpu((*gpt)->header_size)); 426 427 if (crc != origcrc) { 428 Dprintk 429 ("GUID Partition Table Header CRC is wrong: %x != %x\n", 430 crc, origcrc); 431 kfree(*gpt); 432 *gpt = NULL; 433 return 0; 434 } 435 (*gpt)->header_crc32 = cpu_to_le32(origcrc); 436 437 /* Check that the my_lba entry points to the LBA that contains 438 * the GUID Partition Table */ 439 if (le64_to_cpu((*gpt)->my_lba) != lba) { 440 Dprintk("GPT my_lba incorrect: %" PRIx64 " != %" PRIx64 "\n", 441 le64_to_cpu((*gpt)->my_lba), lba); 442 kfree(*gpt); 443 *gpt = NULL; 444 return 0; 445 } 446 447 if (!(*ptes = alloc_read_gpt_entries(hd, bdev, *gpt))) { 448 kfree(*gpt); 449 *gpt = NULL; 450 return 0; 451 } 452 453 /* Check the GUID Partition Entry Array CRC */ 454 crc = efi_crc32((const unsigned char *) (*ptes), 455 le32_to_cpu((*gpt)->num_partition_entries) * 456 le32_to_cpu((*gpt)->sizeof_partition_entry)); 457 458 if (crc != le32_to_cpu((*gpt)->partition_entry_array_crc32)) { 459 Dprintk("GUID Partitition Entry Array CRC check failed.\n"); 460 kfree(*gpt); 461 *gpt = NULL; 462 kfree(*ptes); 463 *ptes = NULL; 464 return 0; 465 } 466 467 /* We're done, all's well */ 468 return 1; 469} 470 471/** 472 * compare_gpts() - Search disk for valid GPT headers and PTEs 473 * @pgpt is the primary GPT header 474 * @agpt is the alternate GPT header 475 * @lastlba is the last LBA number 476 * Description: Returns nothing. Sanity checks pgpt and agpt fields 477 * and prints warnings on discrepancies. 478 * 479 */ 480static void 481compare_gpts(gpt_header *pgpt, gpt_header *agpt, u64 lastlba) 482{ 483 int error_found = 0; 484 if (!pgpt || !agpt) 485 return; 486 if (le64_to_cpu(pgpt->my_lba) != le64_to_cpu(agpt->alternate_lba)) { 487 printk(KERN_WARNING 488 "GPT:Primary header LBA != Alt. header alternate_lba\n"); 489 printk(KERN_WARNING "GPT:%" PRIx64 " != %" PRIx64 "\n", 490 le64_to_cpu(pgpt->my_lba), 491 le64_to_cpu(agpt->alternate_lba)); 492 error_found++; 493 } 494 if (le64_to_cpu(pgpt->alternate_lba) != le64_to_cpu(agpt->my_lba)) { 495 printk(KERN_WARNING 496 "GPT:Primary header alternate_lba != Alt. header my_lba\n"); 497 printk(KERN_WARNING "GPT:%" PRIx64 " != %" PRIx64 "\n", 498 le64_to_cpu(pgpt->alternate_lba), 499 le64_to_cpu(agpt->my_lba)); 500 error_found++; 501 } 502 if (le64_to_cpu(pgpt->first_usable_lba) != 503 le64_to_cpu(agpt->first_usable_lba)) { 504 printk(KERN_WARNING "GPT:first_usable_lbas don't match.\n"); 505 printk(KERN_WARNING "GPT:%" PRIx64 " != %" PRIx64 "\n", 506 le64_to_cpu(pgpt->first_usable_lba), 507 le64_to_cpu(agpt->first_usable_lba)); 508 error_found++; 509 } 510 if (le64_to_cpu(pgpt->last_usable_lba) != 511 le64_to_cpu(agpt->last_usable_lba)) { 512 printk(KERN_WARNING "GPT:last_usable_lbas don't match.\n"); 513 printk(KERN_WARNING "GPT:%" PRIx64 " != %" PRIx64 "\n", 514 le64_to_cpu(pgpt->last_usable_lba), 515 le64_to_cpu(agpt->last_usable_lba)); 516 error_found++; 517 } 518 if (efi_guidcmp(pgpt->disk_guid, agpt->disk_guid)) { 519 printk(KERN_WARNING "GPT:disk_guids don't match.\n"); 520 error_found++; 521 } 522 if (le32_to_cpu(pgpt->num_partition_entries) != 523 le32_to_cpu(agpt->num_partition_entries)) { 524 printk(KERN_WARNING "GPT:num_partition_entries don't match: " 525 "0x%x != 0x%x\n", 526 le32_to_cpu(pgpt->num_partition_entries), 527 le32_to_cpu(agpt->num_partition_entries)); 528 error_found++; 529 } 530 if (le32_to_cpu(pgpt->sizeof_partition_entry) != 531 le32_to_cpu(agpt->sizeof_partition_entry)) { 532 printk(KERN_WARNING 533 "GPT:sizeof_partition_entry values don't match: " 534 "0x%x != 0x%x\n", 535 le32_to_cpu(pgpt->sizeof_partition_entry), 536 le32_to_cpu(agpt->sizeof_partition_entry)); 537 error_found++; 538 } 539 if (le32_to_cpu(pgpt->partition_entry_array_crc32) != 540 le32_to_cpu(agpt->partition_entry_array_crc32)) { 541 printk(KERN_WARNING 542 "GPT:partition_entry_array_crc32 values don't match: " 543 "0x%x != 0x%x\n", 544 le32_to_cpu(pgpt->partition_entry_array_crc32), 545 le32_to_cpu(agpt->partition_entry_array_crc32)); 546 error_found++; 547 } 548 if (le64_to_cpu(pgpt->alternate_lba) != lastlba) { 549 printk(KERN_WARNING 550 "GPT:Primary header thinks Alt. header is not at the end of the disk.\n"); 551 printk(KERN_WARNING "GPT:%" PRIx64 " != %" PRIx64 "\n", 552 le64_to_cpu(pgpt->alternate_lba), lastlba); 553 error_found++; 554 } 555 556 if (le64_to_cpu(agpt->my_lba) != lastlba) { 557 printk(KERN_WARNING 558 "GPT:Alternate GPT header not at the end of the disk.\n"); 559 printk(KERN_WARNING "GPT:%" PRIx64 " != %" PRIx64 "\n", 560 le64_to_cpu(agpt->my_lba), lastlba); 561 error_found++; 562 } 563 564 if (error_found) 565 printk(KERN_WARNING 566 "GPT: Use GNU Parted to correct GPT errors.\n"); 567 return; 568} 569 570/** 571 * find_valid_gpt() - Search disk for valid GPT headers and PTEs 572 * @hd 573 * @bdev 574 * @gpt is a GPT header ptr, filled on return. 575 * @ptes is a PTEs ptr, filled on return. 576 * Description: Returns 1 if valid, 0 on error. 577 * If valid, returns pointers to newly allocated GPT header and PTEs. 578 * Validity depends on finding either the Primary GPT header and PTEs valid, 579 * or the Alternate GPT header and PTEs valid, and the PMBR valid. 580 */ 581static int 582find_valid_gpt(struct gendisk *hd, struct block_device *bdev, 583 gpt_header **gpt, gpt_entry **ptes) 584{ 585 int good_pgpt = 0, good_agpt = 0, good_pmbr = 0; 586 gpt_header *pgpt = NULL, *agpt = NULL; 587 gpt_entry *pptes = NULL, *aptes = NULL; 588 legacy_mbr *legacymbr = NULL; 589 u64 lastlba; 590 if (!hd || !bdev || !gpt || !ptes) 591 return 0; 592 593 lastlba = last_lba(hd, bdev); 594 good_pgpt = is_gpt_valid(hd, bdev, GPT_PRIMARY_PARTITION_TABLE_LBA, 595 &pgpt, &pptes); 596 if (good_pgpt) { 597 good_agpt = is_gpt_valid(hd, bdev, 598 le64_to_cpu(pgpt->alternate_lba), 599 &agpt, &aptes); 600 if (!good_agpt) { 601 good_agpt = is_gpt_valid(hd, bdev, lastlba, 602 &agpt, &aptes); 603 } 604 } 605 else { 606 good_agpt = is_gpt_valid(hd, bdev, lastlba, 607 &agpt, &aptes); 608 } 609 610 /* The obviously unsuccessful case */ 611 if (!good_pgpt && !good_agpt) { 612 goto fail; 613 } 614 615 /* This will be added to the EFI Spec. per Intel after v1.02. */ 616 legacymbr = kmalloc(sizeof (*legacymbr), GFP_KERNEL); 617 if (legacymbr) { 618 memset(legacymbr, 0, sizeof (*legacymbr)); 619 read_lba(hd, bdev, 0, (u8 *) legacymbr, 620 sizeof (*legacymbr)); 621 good_pmbr = is_pmbr_valid(legacymbr); 622 kfree(legacymbr); 623 legacymbr=NULL; 624 } 625 626 /* Failure due to bad PMBR */ 627 if ((good_pgpt || good_agpt) && !good_pmbr && !force_gpt) { 628 printk(KERN_WARNING 629 " Warning: Disk has a valid GPT signature " 630 "but invalid PMBR.\n"); 631 printk(KERN_WARNING 632 " Assuming this disk is *not* a GPT disk anymore.\n"); 633 printk(KERN_WARNING 634 " Use gpt kernel option to override. " 635 "Use GNU Parted to correct disk.\n"); 636 goto fail; 637 } 638 639 /* Would fail due to bad PMBR, but force GPT anyhow */ 640 if ((good_pgpt || good_agpt) && !good_pmbr && force_gpt) { 641 printk(KERN_WARNING 642 " Warning: Disk has a valid GPT signature but " 643 "invalid PMBR.\n"); 644 printk(KERN_WARNING 645 " Use GNU Parted to correct disk.\n"); 646 printk(KERN_WARNING 647 " gpt option taken, disk treated as GPT.\n"); 648 } 649 650 compare_gpts(pgpt, agpt, lastlba); 651 652 /* The good cases */ 653 if (good_pgpt && (good_pmbr || force_gpt)) { 654 *gpt = pgpt; 655 *ptes = pptes; 656 if (agpt) { kfree(agpt); agpt = NULL; } 657 if (aptes) { kfree(aptes); aptes = NULL; } 658 if (!good_agpt) { 659 printk(KERN_WARNING 660 "Alternate GPT is invalid, " 661 "using primary GPT.\n"); 662 } 663 return 1; 664 } 665 else if (good_agpt && (good_pmbr || force_gpt)) { 666 *gpt = agpt; 667 *ptes = aptes; 668 if (pgpt) { kfree(pgpt); pgpt = NULL; } 669 if (pptes) { kfree(pptes); pptes = NULL; } 670 printk(KERN_WARNING 671 "Primary GPT is invalid, using alternate GPT.\n"); 672 return 1; 673 } 674 675 fail: 676 if (pgpt) { kfree(pgpt); pgpt=NULL; } 677 if (agpt) { kfree(agpt); agpt=NULL; } 678 if (pptes) { kfree(pptes); pptes=NULL; } 679 if (aptes) { kfree(aptes); aptes=NULL; } 680 *gpt = NULL; 681 *ptes = NULL; 682 return 0; 683} 684 685/** 686 * add_gpt_partitions(struct gendisk *hd, struct block_device *bdev, 687 * @hd 688 * @bdev 689 * 690 * Description: Create devices for each entry in the GUID Partition Table 691 * Entries. 692 * 693 * We do not create a Linux partition for GPT, but 694 * only for the actual data partitions. 695 * Returns: 696 * -1 if unable to read the partition table 697 * 0 if this isn't our partition table 698 * 1 if successful 699 * 700 */ 701static int 702add_gpt_partitions(struct gendisk *hd, struct block_device *bdev, int nextminor) 703{ 704 gpt_header *gpt = NULL; 705 gpt_entry *ptes = NULL; 706 u32 i; 707 int max_p; 708 709 if (!hd || !bdev) 710 return -1; 711 712 if (!find_valid_gpt(hd, bdev, &gpt, &ptes) || !gpt || !ptes) { 713 if (gpt) { 714 kfree(gpt); 715 gpt = NULL; 716 } 717 if (ptes) { 718 kfree(ptes); 719 ptes = NULL; 720 } 721 return 0; 722 } 723 724 Dprintk("GUID Partition Table is valid! Yea!\n"); 725 726 max_p = (1 << hd->minor_shift) - 1; 727 for (i = 0; i < le32_to_cpu(gpt->num_partition_entries) && i < max_p; i++) { 728 if (!efi_guidcmp(ptes[i].partition_type_guid, NULL_GUID)) 729 continue; 730 731 add_gd_partition(hd, nextminor+i, 732 le64_to_cpu(ptes[i].starting_lba), 733 (le64_to_cpu(ptes[i].ending_lba) - 734 le64_to_cpu(ptes[i].starting_lba) + 735 1)); 736 737 /* If there's this is a RAID volume, tell md */ 738#if CONFIG_BLK_DEV_MD 739 if (!efi_guidcmp(ptes[i].partition_type_guid, 740 PARTITION_LINUX_RAID_GUID)) { 741 md_autodetect_dev(MKDEV 742 (MAJOR(to_kdev_t(bdev->bd_dev)), 743 nextminor+i)); 744 } 745#endif 746 } 747 kfree(ptes); 748 ptes=NULL; 749 kfree(gpt); 750 gpt=NULL; 751 printk("\n"); 752 return 1; 753} 754 755/** 756 * efi_partition(): EFI GPT partition handling entry function 757 * @hd 758 * @bdev 759 * @first_sector: unused 760 * @first_part_minor: minor number assigned to first GPT partition found 761 * 762 * Description: called from check.c, if the disk contains GPT 763 * partitions, sets up partition entries in the kernel. 764 * 765 * If the first block on the disk is a legacy MBR, 766 * it will get handled by msdos_partition(). 767 * If it's a Protective MBR, we'll handle it here. 768 * 769 * set_blocksize() calls are necessary to be able to read 770 * a disk with an odd number of 512-byte sectors, as the 771 * default BLOCK_SIZE of 1024 bytes won't let that last 772 * sector be read otherwise. 773 * 774 * Returns: 775 * -1 if unable to read the partition table 776 * 0 if this isn't our partitoin table 777 * 1 if successful 778 */ 779int 780efi_partition(struct gendisk *hd, struct block_device *bdev, 781 unsigned long first_sector, int first_part_minor) 782{ 783 784 kdev_t dev = to_kdev_t(bdev->bd_dev); 785 int hardblocksize = get_hardsect_size(dev); 786 int orig_blksize_size = BLOCK_SIZE; 787 int rc = 0; 788 789 /* Need to change the block size that the block layer uses */ 790 if (blksize_size[MAJOR(dev)]) { 791 orig_blksize_size = blksize_size[MAJOR(dev)][MINOR(dev)]; 792 } 793 794 if (orig_blksize_size != hardblocksize) 795 set_blocksize(dev, hardblocksize); 796 797 rc = add_gpt_partitions(hd, bdev, first_part_minor); 798 799 /* change back */ 800 if (orig_blksize_size != hardblocksize) 801 set_blocksize(dev, orig_blksize_size); 802 803 return rc; 804} 805