1 /* 2 * GRUB -- GRand Unified Bootloader 3 * Copyright (C) 1999,2000,2001,2002,2003,2004 Free Software Foundation, Inc. 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License as published by 7 * the Free Software Foundation; either version 2 of the License, or 8 * (at your option) any later version. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to the Free Software 17 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 18 */ 19 20 /* 21 * Copyright 2010 Sun Microsystems, Inc. All rights reserved. 22 * Use is subject to license terms. 23 */ 24 25 /* 26 * Copyright (c) 2012 by Delphix. All rights reserved. 27 * Copyright (c) 2013 by Saso Kiselkov. All rights reserved. 28 */ 29 30 /* 31 * The zfs plug-in routines for GRUB are: 32 * 33 * zfs_mount() - locates a valid uberblock of the root pool and reads 34 * in its MOS at the memory address MOS. 35 * 36 * zfs_open() - locates a plain file object by following the MOS 37 * and places its dnode at the memory address DNODE. 38 * 39 * zfs_read() - read in the data blocks pointed by the DNODE. 40 * 41 * ZFS_SCRATCH is used as a working area. 42 * 43 * (memory addr) MOS DNODE ZFS_SCRATCH 44 * | | | 45 * +-------V---------V----------V---------------+ 46 * memory | | dnode | dnode | scratch | 47 * | | 512B | 512B | area | 48 * +--------------------------------------------+ 49 */ 50 51 #ifdef FSYS_ZFS 52 53 #include "shared.h" 54 #include "filesys.h" 55 #include "fsys_zfs.h" 56 57 /* cache for a file block of the currently zfs_open()-ed file */ 58 static void *file_buf = NULL; 59 static uint64_t file_start = 0; 60 static uint64_t file_end = 0; 61 62 /* cache for a dnode block */ 63 static dnode_phys_t *dnode_buf = NULL; 64 static dnode_phys_t *dnode_mdn = NULL; 65 static uint64_t dnode_start = 0; 66 static uint64_t dnode_end = 0; 67 68 static uint64_t pool_guid = 0; 69 static uberblock_t current_uberblock; 70 static char *stackbase; 71 72 decomp_entry_t decomp_table[ZIO_COMPRESS_FUNCTIONS] = 73 { 74 {"inherit", 0}, /* ZIO_COMPRESS_INHERIT */ 75 {"on", lzjb_decompress}, /* ZIO_COMPRESS_ON */ 76 {"off", 0}, /* ZIO_COMPRESS_OFF */ 77 {"lzjb", lzjb_decompress}, /* ZIO_COMPRESS_LZJB */ 78 {"empty", 0}, /* ZIO_COMPRESS_EMPTY */ 79 {"gzip-1", 0}, /* ZIO_COMPRESS_GZIP_1 */ 80 {"gzip-2", 0}, /* ZIO_COMPRESS_GZIP_2 */ 81 {"gzip-3", 0}, /* ZIO_COMPRESS_GZIP_3 */ 82 {"gzip-4", 0}, /* ZIO_COMPRESS_GZIP_4 */ 83 {"gzip-5", 0}, /* ZIO_COMPRESS_GZIP_5 */ 84 {"gzip-6", 0}, /* ZIO_COMPRESS_GZIP_6 */ 85 {"gzip-7", 0}, /* ZIO_COMPRESS_GZIP_7 */ 86 {"gzip-8", 0}, /* ZIO_COMPRESS_GZIP_8 */ 87 {"gzip-9", 0}, /* ZIO_COMPRESS_GZIP_9 */ 88 {"zle", 0}, /* ZIO_COMPRESS_ZLE */ 89 {"lz4", lz4_decompress} /* ZIO_COMPRESS_LZ4 */ 90 }; 91 92 static int zio_read_data(blkptr_t *bp, void *buf, char *stack); 93 94 /* 95 * Our own version of bcmp(). 96 */ 97 static int 98 zfs_bcmp(const void *s1, const void *s2, size_t n) 99 { 100 const uchar_t *ps1 = s1; 101 const uchar_t *ps2 = s2; 102 103 if (s1 != s2 && n != 0) { 104 do { 105 if (*ps1++ != *ps2++) 106 return (1); 107 } while (--n != 0); 108 } 109 110 return (0); 111 } 112 113 /* 114 * Our own version of log2(). Same thing as highbit()-1. 115 */ 116 static int 117 zfs_log2(uint64_t num) 118 { 119 int i = 0; 120 121 while (num > 1) { 122 i++; 123 num = num >> 1; 124 } 125 126 return (i); 127 } 128 129 /* Checksum Functions */ 130 static void 131 zio_checksum_off(const void *buf, uint64_t size, zio_cksum_t *zcp) 132 { 133 ZIO_SET_CHECKSUM(zcp, 0, 0, 0, 0); 134 } 135 136 /* Checksum Table and Values */ 137 zio_checksum_info_t zio_checksum_table[ZIO_CHECKSUM_FUNCTIONS] = { 138 {{NULL, NULL}, 0, 0, "inherit"}, 139 {{NULL, NULL}, 0, 0, "on"}, 140 {{zio_checksum_off, zio_checksum_off}, 0, 0, "off"}, 141 {{zio_checksum_SHA256, zio_checksum_SHA256}, 1, 1, "label"}, 142 {{zio_checksum_SHA256, zio_checksum_SHA256}, 1, 1, "gang_header"}, 143 {{NULL, NULL}, 0, 0, "zilog"}, 144 {{fletcher_2_native, fletcher_2_byteswap}, 0, 0, "fletcher2"}, 145 {{fletcher_4_native, fletcher_4_byteswap}, 1, 0, "fletcher4"}, 146 {{zio_checksum_SHA256, zio_checksum_SHA256}, 1, 0, "SHA256"}, 147 {{NULL, NULL}, 0, 0, "zilog2"}, 148 }; 149 150 /* 151 * zio_checksum_verify: Provides support for checksum verification. 152 * 153 * Fletcher2, Fletcher4, and SHA256 are supported. 154 * 155 * Return: 156 * -1 = Failure 157 * 0 = Success 158 */ 159 static int 160 zio_checksum_verify(blkptr_t *bp, char *data, int size) 161 { 162 zio_cksum_t zc = bp->blk_cksum; 163 uint32_t checksum = BP_GET_CHECKSUM(bp); 164 int byteswap = BP_SHOULD_BYTESWAP(bp); 165 zio_eck_t *zec = (zio_eck_t *)(data + size) - 1; 166 zio_checksum_info_t *ci = &zio_checksum_table[checksum]; 167 zio_cksum_t actual_cksum, expected_cksum; 168 169 /* byteswap is not supported */ 170 if (byteswap) 171 return (-1); 172 173 if (checksum >= ZIO_CHECKSUM_FUNCTIONS || ci->ci_func[0] == NULL) 174 return (-1); 175 176 if (ci->ci_eck) { 177 expected_cksum = zec->zec_cksum; 178 zec->zec_cksum = zc; 179 ci->ci_func[0](data, size, &actual_cksum); 180 zec->zec_cksum = expected_cksum; 181 zc = expected_cksum; 182 183 } else { 184 ci->ci_func[byteswap](data, size, &actual_cksum); 185 } 186 187 if ((actual_cksum.zc_word[0] - zc.zc_word[0]) | 188 (actual_cksum.zc_word[1] - zc.zc_word[1]) | 189 (actual_cksum.zc_word[2] - zc.zc_word[2]) | 190 (actual_cksum.zc_word[3] - zc.zc_word[3])) 191 return (-1); 192 193 return (0); 194 } 195 196 /* 197 * vdev_label_start returns the physical disk offset (in bytes) of 198 * label "l". 199 */ 200 static uint64_t 201 vdev_label_start(uint64_t psize, int l) 202 { 203 return (l * sizeof (vdev_label_t) + (l < VDEV_LABELS / 2 ? 204 0 : psize - VDEV_LABELS * sizeof (vdev_label_t))); 205 } 206 207 /* 208 * vdev_uberblock_compare takes two uberblock structures and returns an integer 209 * indicating the more recent of the two. 210 * Return Value = 1 if ub2 is more recent 211 * Return Value = -1 if ub1 is more recent 212 * The most recent uberblock is determined using its transaction number and 213 * timestamp. The uberblock with the highest transaction number is 214 * considered "newer". If the transaction numbers of the two blocks match, the 215 * timestamps are compared to determine the "newer" of the two. 216 */ 217 static int 218 vdev_uberblock_compare(uberblock_t *ub1, uberblock_t *ub2) 219 { 220 if (ub1->ub_txg < ub2->ub_txg) 221 return (-1); 222 if (ub1->ub_txg > ub2->ub_txg) 223 return (1); 224 225 if (ub1->ub_timestamp < ub2->ub_timestamp) 226 return (-1); 227 if (ub1->ub_timestamp > ub2->ub_timestamp) 228 return (1); 229 230 return (0); 231 } 232 233 /* 234 * Three pieces of information are needed to verify an uberblock: the magic 235 * number, the version number, and the checksum. 236 * 237 * Return: 238 * 0 - Success 239 * -1 - Failure 240 */ 241 static int 242 uberblock_verify(uberblock_t *uber, uint64_t ub_size, uint64_t offset) 243 { 244 blkptr_t bp; 245 246 BP_ZERO(&bp); 247 BP_SET_CHECKSUM(&bp, ZIO_CHECKSUM_LABEL); 248 BP_SET_BYTEORDER(&bp, ZFS_HOST_BYTEORDER); 249 ZIO_SET_CHECKSUM(&bp.blk_cksum, offset, 0, 0, 0); 250 251 if (zio_checksum_verify(&bp, (char *)uber, ub_size) != 0) 252 return (-1); 253 254 if (uber->ub_magic == UBERBLOCK_MAGIC && 255 SPA_VERSION_IS_SUPPORTED(uber->ub_version)) 256 return (0); 257 258 return (-1); 259 } 260 261 /* 262 * Find the best uberblock. 263 * Return: 264 * Success - Pointer to the best uberblock. 265 * Failure - NULL 266 */ 267 static uberblock_t * 268 find_bestub(char *ub_array, uint64_t ashift, uint64_t sector) 269 { 270 uberblock_t *ubbest = NULL; 271 uberblock_t *ubnext; 272 uint64_t offset, ub_size; 273 int i; 274 275 ub_size = VDEV_UBERBLOCK_SIZE(ashift); 276 277 for (i = 0; i < VDEV_UBERBLOCK_COUNT(ashift); i++) { 278 ubnext = (uberblock_t *)ub_array; 279 ub_array += ub_size; 280 offset = (sector << SPA_MINBLOCKSHIFT) + 281 VDEV_UBERBLOCK_OFFSET(ashift, i); 282 283 if (uberblock_verify(ubnext, ub_size, offset) != 0) 284 continue; 285 286 if (ubbest == NULL || 287 vdev_uberblock_compare(ubnext, ubbest) > 0) 288 ubbest = ubnext; 289 } 290 291 return (ubbest); 292 } 293 294 /* 295 * Read a block of data based on the gang block address dva, 296 * and put its data in buf. 297 * 298 * Return: 299 * 0 - success 300 * 1 - failure 301 */ 302 static int 303 zio_read_gang(blkptr_t *bp, dva_t *dva, void *buf, char *stack) 304 { 305 zio_gbh_phys_t *zio_gb; 306 uint64_t offset, sector; 307 blkptr_t tmpbp; 308 int i; 309 310 zio_gb = (zio_gbh_phys_t *)stack; 311 stack += SPA_GANGBLOCKSIZE; 312 offset = DVA_GET_OFFSET(dva); 313 sector = DVA_OFFSET_TO_PHYS_SECTOR(offset); 314 315 /* read in the gang block header */ 316 if (devread(sector, 0, SPA_GANGBLOCKSIZE, (char *)zio_gb) == 0) { 317 grub_printf("failed to read in a gang block header\n"); 318 return (1); 319 } 320 321 /* self checksuming the gang block header */ 322 BP_ZERO(&tmpbp); 323 BP_SET_CHECKSUM(&tmpbp, ZIO_CHECKSUM_GANG_HEADER); 324 BP_SET_BYTEORDER(&tmpbp, ZFS_HOST_BYTEORDER); 325 ZIO_SET_CHECKSUM(&tmpbp.blk_cksum, DVA_GET_VDEV(dva), 326 DVA_GET_OFFSET(dva), bp->blk_birth, 0); 327 if (zio_checksum_verify(&tmpbp, (char *)zio_gb, SPA_GANGBLOCKSIZE)) { 328 grub_printf("failed to checksum a gang block header\n"); 329 return (1); 330 } 331 332 for (i = 0; i < SPA_GBH_NBLKPTRS; i++) { 333 if (zio_gb->zg_blkptr[i].blk_birth == 0) 334 continue; 335 336 if (zio_read_data(&zio_gb->zg_blkptr[i], buf, stack)) 337 return (1); 338 buf += BP_GET_PSIZE(&zio_gb->zg_blkptr[i]); 339 } 340 341 return (0); 342 } 343 344 /* 345 * Read in a block of raw data to buf. 346 * 347 * Return: 348 * 0 - success 349 * 1 - failure 350 */ 351 static int 352 zio_read_data(blkptr_t *bp, void *buf, char *stack) 353 { 354 int i, psize; 355 356 psize = BP_GET_PSIZE(bp); 357 358 /* pick a good dva from the block pointer */ 359 for (i = 0; i < SPA_DVAS_PER_BP; i++) { 360 uint64_t offset, sector; 361 362 if (bp->blk_dva[i].dva_word[0] == 0 && 363 bp->blk_dva[i].dva_word[1] == 0) 364 continue; 365 366 if (DVA_GET_GANG(&bp->blk_dva[i])) { 367 if (zio_read_gang(bp, &bp->blk_dva[i], buf, stack) == 0) 368 return (0); 369 } else { 370 /* read in a data block */ 371 offset = DVA_GET_OFFSET(&bp->blk_dva[i]); 372 sector = DVA_OFFSET_TO_PHYS_SECTOR(offset); 373 if (devread(sector, 0, psize, buf) != 0) 374 return (0); 375 } 376 } 377 378 return (1); 379 } 380 381 /* 382 * Read in a block of data, verify its checksum, decompress if needed, 383 * and put the uncompressed data in buf. 384 * 385 * Return: 386 * 0 - success 387 * errnum - failure 388 */ 389 static int 390 zio_read(blkptr_t *bp, void *buf, char *stack) 391 { 392 int lsize, psize, comp; 393 char *retbuf; 394 395 comp = BP_GET_COMPRESS(bp); 396 lsize = BP_GET_LSIZE(bp); 397 psize = BP_GET_PSIZE(bp); 398 399 if ((unsigned int)comp >= ZIO_COMPRESS_FUNCTIONS || 400 (comp != ZIO_COMPRESS_OFF && 401 decomp_table[comp].decomp_func == NULL)) { 402 grub_printf("compression algorithm not supported\n"); 403 return (ERR_FSYS_CORRUPT); 404 } 405 406 if ((char *)buf < stack && ((char *)buf) + lsize > stack) { 407 grub_printf("not enough memory allocated\n"); 408 return (ERR_WONT_FIT); 409 } 410 411 retbuf = buf; 412 if (comp != ZIO_COMPRESS_OFF) { 413 buf = stack; 414 stack += psize; 415 } 416 417 if (zio_read_data(bp, buf, stack) != 0) { 418 grub_printf("zio_read_data failed\n"); 419 return (ERR_FSYS_CORRUPT); 420 } 421 422 if (zio_checksum_verify(bp, buf, psize) != 0) { 423 grub_printf("checksum verification failed\n"); 424 return (ERR_FSYS_CORRUPT); 425 } 426 427 if (comp != ZIO_COMPRESS_OFF) { 428 if (decomp_table[comp].decomp_func(buf, retbuf, psize, 429 lsize) != 0) { 430 grub_printf("zio_read decompression failed\n"); 431 return (ERR_FSYS_CORRUPT); 432 } 433 } 434 435 return (0); 436 } 437 438 /* 439 * Get the block from a block id. 440 * push the block onto the stack. 441 * 442 * Return: 443 * 0 - success 444 * errnum - failure 445 */ 446 static int 447 dmu_read(dnode_phys_t *dn, uint64_t blkid, void *buf, char *stack) 448 { 449 int idx, level; 450 blkptr_t *bp_array = dn->dn_blkptr; 451 int epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 452 blkptr_t *bp, *tmpbuf; 453 454 bp = (blkptr_t *)stack; 455 stack += sizeof (blkptr_t); 456 457 tmpbuf = (blkptr_t *)stack; 458 stack += 1<<dn->dn_indblkshift; 459 460 for (level = dn->dn_nlevels - 1; level >= 0; level--) { 461 idx = (blkid >> (epbs * level)) & ((1<<epbs)-1); 462 *bp = bp_array[idx]; 463 if (level == 0) 464 tmpbuf = buf; 465 if (BP_IS_HOLE(bp)) { 466 grub_memset(buf, 0, 467 dn->dn_datablkszsec << SPA_MINBLOCKSHIFT); 468 break; 469 } else if (errnum = zio_read(bp, tmpbuf, stack)) { 470 return (errnum); 471 } 472 473 bp_array = tmpbuf; 474 } 475 476 return (0); 477 } 478 479 /* 480 * mzap_lookup: Looks up property described by "name" and returns the value 481 * in "value". 482 * 483 * Return: 484 * 0 - success 485 * errnum - failure 486 */ 487 static int 488 mzap_lookup(mzap_phys_t *zapobj, int objsize, const char *name, 489 uint64_t *value) 490 { 491 int i, chunks; 492 mzap_ent_phys_t *mzap_ent = zapobj->mz_chunk; 493 494 chunks = objsize / MZAP_ENT_LEN - 1; 495 for (i = 0; i < chunks; i++) { 496 if (grub_strcmp(mzap_ent[i].mze_name, name) == 0) { 497 *value = mzap_ent[i].mze_value; 498 return (0); 499 } 500 } 501 502 return (ERR_FSYS_CORRUPT); 503 } 504 505 static uint64_t 506 zap_hash(uint64_t salt, const char *name) 507 { 508 static uint64_t table[256]; 509 const uint8_t *cp; 510 uint8_t c; 511 uint64_t crc = salt; 512 513 if (table[128] == 0) { 514 uint64_t *ct; 515 int i, j; 516 for (i = 0; i < 256; i++) { 517 for (ct = table + i, *ct = i, j = 8; j > 0; j--) 518 *ct = (*ct >> 1) ^ (-(*ct & 1) & 519 ZFS_CRC64_POLY); 520 } 521 } 522 523 if (crc == 0 || table[128] != ZFS_CRC64_POLY) { 524 errnum = ERR_FSYS_CORRUPT; 525 return (0); 526 } 527 528 for (cp = (const uint8_t *)name; (c = *cp) != '\0'; cp++) 529 crc = (crc >> 8) ^ table[(crc ^ c) & 0xFF]; 530 531 /* 532 * Only use 28 bits, since we need 4 bits in the cookie for the 533 * collision differentiator. We MUST use the high bits, since 534 * those are the ones that we first pay attention to when 535 * choosing the bucket. 536 */ 537 crc &= ~((1ULL << (64 - 28)) - 1); 538 539 return (crc); 540 } 541 542 /* 543 * Only to be used on 8-bit arrays. 544 * array_len is actual len in bytes (not encoded le_value_length). 545 * buf is null-terminated. 546 */ 547 static int 548 zap_leaf_array_equal(zap_leaf_phys_t *l, int blksft, int chunk, 549 int array_len, const char *buf) 550 { 551 int bseen = 0; 552 553 while (bseen < array_len) { 554 struct zap_leaf_array *la = 555 &ZAP_LEAF_CHUNK(l, blksft, chunk).l_array; 556 int toread = MIN(array_len - bseen, ZAP_LEAF_ARRAY_BYTES); 557 558 if (chunk >= ZAP_LEAF_NUMCHUNKS(blksft)) 559 return (0); 560 561 if (zfs_bcmp(la->la_array, buf + bseen, toread) != 0) 562 break; 563 chunk = la->la_next; 564 bseen += toread; 565 } 566 return (bseen == array_len); 567 } 568 569 /* 570 * Given a zap_leaf_phys_t, walk thru the zap leaf chunks to get the 571 * value for the property "name". 572 * 573 * Return: 574 * 0 - success 575 * errnum - failure 576 */ 577 static int 578 zap_leaf_lookup(zap_leaf_phys_t *l, int blksft, uint64_t h, 579 const char *name, uint64_t *value) 580 { 581 uint16_t chunk; 582 struct zap_leaf_entry *le; 583 584 /* Verify if this is a valid leaf block */ 585 if (l->l_hdr.lh_block_type != ZBT_LEAF) 586 return (ERR_FSYS_CORRUPT); 587 if (l->l_hdr.lh_magic != ZAP_LEAF_MAGIC) 588 return (ERR_FSYS_CORRUPT); 589 590 for (chunk = l->l_hash[LEAF_HASH(blksft, h)]; 591 chunk != CHAIN_END; chunk = le->le_next) { 592 593 if (chunk >= ZAP_LEAF_NUMCHUNKS(blksft)) 594 return (ERR_FSYS_CORRUPT); 595 596 le = ZAP_LEAF_ENTRY(l, blksft, chunk); 597 598 /* Verify the chunk entry */ 599 if (le->le_type != ZAP_CHUNK_ENTRY) 600 return (ERR_FSYS_CORRUPT); 601 602 if (le->le_hash != h) 603 continue; 604 605 if (zap_leaf_array_equal(l, blksft, le->le_name_chunk, 606 le->le_name_length, name)) { 607 608 struct zap_leaf_array *la; 609 uint8_t *ip; 610 611 if (le->le_int_size != 8 || le->le_value_length != 1) 612 return (ERR_FSYS_CORRUPT); 613 614 /* get the uint64_t property value */ 615 la = &ZAP_LEAF_CHUNK(l, blksft, 616 le->le_value_chunk).l_array; 617 ip = la->la_array; 618 619 *value = (uint64_t)ip[0] << 56 | (uint64_t)ip[1] << 48 | 620 (uint64_t)ip[2] << 40 | (uint64_t)ip[3] << 32 | 621 (uint64_t)ip[4] << 24 | (uint64_t)ip[5] << 16 | 622 (uint64_t)ip[6] << 8 | (uint64_t)ip[7]; 623 624 return (0); 625 } 626 } 627 628 return (ERR_FSYS_CORRUPT); 629 } 630 631 /* 632 * Fat ZAP lookup 633 * 634 * Return: 635 * 0 - success 636 * errnum - failure 637 */ 638 static int 639 fzap_lookup(dnode_phys_t *zap_dnode, zap_phys_t *zap, 640 const char *name, uint64_t *value, char *stack) 641 { 642 zap_leaf_phys_t *l; 643 uint64_t hash, idx, blkid; 644 int blksft = zfs_log2(zap_dnode->dn_datablkszsec << DNODE_SHIFT); 645 646 /* Verify if this is a fat zap header block */ 647 if (zap->zap_magic != (uint64_t)ZAP_MAGIC || 648 zap->zap_flags != 0) 649 return (ERR_FSYS_CORRUPT); 650 651 hash = zap_hash(zap->zap_salt, name); 652 if (errnum) 653 return (errnum); 654 655 /* get block id from index */ 656 if (zap->zap_ptrtbl.zt_numblks != 0) { 657 /* external pointer tables not supported */ 658 return (ERR_FSYS_CORRUPT); 659 } 660 idx = ZAP_HASH_IDX(hash, zap->zap_ptrtbl.zt_shift); 661 blkid = ((uint64_t *)zap)[idx + (1<<(blksft-3-1))]; 662 663 /* Get the leaf block */ 664 l = (zap_leaf_phys_t *)stack; 665 stack += 1<<blksft; 666 if ((1<<blksft) < sizeof (zap_leaf_phys_t)) 667 return (ERR_FSYS_CORRUPT); 668 if (errnum = dmu_read(zap_dnode, blkid, l, stack)) 669 return (errnum); 670 671 return (zap_leaf_lookup(l, blksft, hash, name, value)); 672 } 673 674 /* 675 * Read in the data of a zap object and find the value for a matching 676 * property name. 677 * 678 * Return: 679 * 0 - success 680 * errnum - failure 681 */ 682 static int 683 zap_lookup(dnode_phys_t *zap_dnode, const char *name, uint64_t *val, 684 char *stack) 685 { 686 uint64_t block_type; 687 int size; 688 void *zapbuf; 689 690 /* Read in the first block of the zap object data. */ 691 zapbuf = stack; 692 size = zap_dnode->dn_datablkszsec << SPA_MINBLOCKSHIFT; 693 stack += size; 694 695 if ((errnum = dmu_read(zap_dnode, 0, zapbuf, stack)) != 0) 696 return (errnum); 697 698 block_type = *((uint64_t *)zapbuf); 699 700 if (block_type == ZBT_MICRO) { 701 return (mzap_lookup(zapbuf, size, name, val)); 702 } else if (block_type == ZBT_HEADER) { 703 /* this is a fat zap */ 704 return (fzap_lookup(zap_dnode, zapbuf, name, 705 val, stack)); 706 } 707 708 return (ERR_FSYS_CORRUPT); 709 } 710 711 typedef struct zap_attribute { 712 int za_integer_length; 713 uint64_t za_num_integers; 714 uint64_t za_first_integer; 715 char *za_name; 716 } zap_attribute_t; 717 718 typedef int (zap_cb_t)(zap_attribute_t *za, void *arg, char *stack); 719 720 static int 721 zap_iterate(dnode_phys_t *zap_dnode, zap_cb_t *cb, void *arg, char *stack) 722 { 723 uint32_t size = zap_dnode->dn_datablkszsec << SPA_MINBLOCKSHIFT; 724 zap_attribute_t za; 725 int i; 726 mzap_phys_t *mzp = (mzap_phys_t *)stack; 727 stack += size; 728 729 if ((errnum = dmu_read(zap_dnode, 0, mzp, stack)) != 0) 730 return (errnum); 731 732 /* 733 * Iteration over fatzap objects has not yet been implemented. 734 * If we encounter a pool in which there are more features for 735 * read than can fit inside a microzap (i.e., more than 2048 736 * features for read), we can add support for fatzap iteration. 737 * For now, fail. 738 */ 739 if (mzp->mz_block_type != ZBT_MICRO) { 740 grub_printf("feature information stored in fatzap, pool " 741 "version not supported\n"); 742 return (1); 743 } 744 745 za.za_integer_length = 8; 746 za.za_num_integers = 1; 747 for (i = 0; i < size / MZAP_ENT_LEN - 1; i++) { 748 mzap_ent_phys_t *mzep = &mzp->mz_chunk[i]; 749 int err; 750 751 za.za_first_integer = mzep->mze_value; 752 za.za_name = mzep->mze_name; 753 err = cb(&za, arg, stack); 754 if (err != 0) 755 return (err); 756 } 757 758 return (0); 759 } 760 761 /* 762 * Get the dnode of an object number from the metadnode of an object set. 763 * 764 * Input 765 * mdn - metadnode to get the object dnode 766 * objnum - object number for the object dnode 767 * buf - data buffer that holds the returning dnode 768 * stack - scratch area 769 * 770 * Return: 771 * 0 - success 772 * errnum - failure 773 */ 774 static int 775 dnode_get(dnode_phys_t *mdn, uint64_t objnum, uint8_t type, dnode_phys_t *buf, 776 char *stack) 777 { 778 uint64_t blkid, blksz; /* the block id this object dnode is in */ 779 int epbs; /* shift of number of dnodes in a block */ 780 int idx; /* index within a block */ 781 dnode_phys_t *dnbuf; 782 783 blksz = mdn->dn_datablkszsec << SPA_MINBLOCKSHIFT; 784 epbs = zfs_log2(blksz) - DNODE_SHIFT; 785 blkid = objnum >> epbs; 786 idx = objnum & ((1<<epbs)-1); 787 788 if (dnode_buf != NULL && dnode_mdn == mdn && 789 objnum >= dnode_start && objnum < dnode_end) { 790 grub_memmove(buf, &dnode_buf[idx], DNODE_SIZE); 791 VERIFY_DN_TYPE(buf, type); 792 return (0); 793 } 794 795 if (dnode_buf && blksz == 1<<DNODE_BLOCK_SHIFT) { 796 dnbuf = dnode_buf; 797 dnode_mdn = mdn; 798 dnode_start = blkid << epbs; 799 dnode_end = (blkid + 1) << epbs; 800 } else { 801 dnbuf = (dnode_phys_t *)stack; 802 stack += blksz; 803 } 804 805 if (errnum = dmu_read(mdn, blkid, (char *)dnbuf, stack)) 806 return (errnum); 807 808 grub_memmove(buf, &dnbuf[idx], DNODE_SIZE); 809 VERIFY_DN_TYPE(buf, type); 810 811 return (0); 812 } 813 814 /* 815 * Check if this is a special file that resides at the top 816 * dataset of the pool. Currently this is the GRUB menu, 817 * boot signature and boot signature backup. 818 * str starts with '/'. 819 */ 820 static int 821 is_top_dataset_file(char *str) 822 { 823 char *tptr; 824 825 if ((tptr = grub_strstr(str, "menu.lst")) && 826 (tptr[8] == '\0' || tptr[8] == ' ') && 827 *(tptr-1) == '/') 828 return (1); 829 830 if (grub_strncmp(str, BOOTSIGN_DIR"/", 831 grub_strlen(BOOTSIGN_DIR) + 1) == 0) 832 return (1); 833 834 if (grub_strcmp(str, BOOTSIGN_BACKUP) == 0) 835 return (1); 836 837 return (0); 838 } 839 840 static int 841 check_feature(zap_attribute_t *za, void *arg, char *stack) 842 { 843 const char **names = arg; 844 int i; 845 846 if (za->za_first_integer == 0) 847 return (0); 848 849 for (i = 0; names[i] != NULL; i++) { 850 if (grub_strcmp(za->za_name, names[i]) == 0) { 851 return (0); 852 } 853 } 854 grub_printf("missing feature for read '%s'\n", za->za_name); 855 return (ERR_NEWER_VERSION); 856 } 857 858 /* 859 * Get the file dnode for a given file name where mdn is the meta dnode 860 * for this ZFS object set. When found, place the file dnode in dn. 861 * The 'path' argument will be mangled. 862 * 863 * Return: 864 * 0 - success 865 * errnum - failure 866 */ 867 static int 868 dnode_get_path(dnode_phys_t *mdn, char *path, dnode_phys_t *dn, 869 char *stack) 870 { 871 uint64_t objnum, version; 872 char *cname, ch; 873 874 if (errnum = dnode_get(mdn, MASTER_NODE_OBJ, DMU_OT_MASTER_NODE, 875 dn, stack)) 876 return (errnum); 877 878 if (errnum = zap_lookup(dn, ZPL_VERSION_STR, &version, stack)) 879 return (errnum); 880 if (version > ZPL_VERSION) 881 return (-1); 882 883 if (errnum = zap_lookup(dn, ZFS_ROOT_OBJ, &objnum, stack)) 884 return (errnum); 885 886 if (errnum = dnode_get(mdn, objnum, DMU_OT_DIRECTORY_CONTENTS, 887 dn, stack)) 888 return (errnum); 889 890 /* skip leading slashes */ 891 while (*path == '/') 892 path++; 893 894 while (*path && !grub_isspace(*path)) { 895 896 /* get the next component name */ 897 cname = path; 898 while (*path && !grub_isspace(*path) && *path != '/') 899 path++; 900 ch = *path; 901 *path = 0; /* ensure null termination */ 902 903 if (errnum = zap_lookup(dn, cname, &objnum, stack)) 904 return (errnum); 905 906 objnum = ZFS_DIRENT_OBJ(objnum); 907 if (errnum = dnode_get(mdn, objnum, 0, dn, stack)) 908 return (errnum); 909 910 *path = ch; 911 while (*path == '/') 912 path++; 913 } 914 915 /* We found the dnode for this file. Verify if it is a plain file. */ 916 VERIFY_DN_TYPE(dn, DMU_OT_PLAIN_FILE_CONTENTS); 917 918 return (0); 919 } 920 921 /* 922 * Get the default 'bootfs' property value from the rootpool. 923 * 924 * Return: 925 * 0 - success 926 * errnum -failure 927 */ 928 static int 929 get_default_bootfsobj(dnode_phys_t *mosmdn, uint64_t *obj, char *stack) 930 { 931 uint64_t objnum = 0; 932 dnode_phys_t *dn = (dnode_phys_t *)stack; 933 stack += DNODE_SIZE; 934 935 if (errnum = dnode_get(mosmdn, DMU_POOL_DIRECTORY_OBJECT, 936 DMU_OT_OBJECT_DIRECTORY, dn, stack)) 937 return (errnum); 938 939 /* 940 * find the object number for 'pool_props', and get the dnode 941 * of the 'pool_props'. 942 */ 943 if (zap_lookup(dn, DMU_POOL_PROPS, &objnum, stack)) 944 return (ERR_FILESYSTEM_NOT_FOUND); 945 946 if (errnum = dnode_get(mosmdn, objnum, DMU_OT_POOL_PROPS, dn, stack)) 947 return (errnum); 948 949 if (zap_lookup(dn, ZPOOL_PROP_BOOTFS, &objnum, stack)) 950 return (ERR_FILESYSTEM_NOT_FOUND); 951 952 if (!objnum) 953 return (ERR_FILESYSTEM_NOT_FOUND); 954 955 *obj = objnum; 956 return (0); 957 } 958 959 /* 960 * List of pool features that the grub implementation of ZFS supports for 961 * read. Note that features that are only required for write do not need 962 * to be listed here since grub opens pools in read-only mode. 963 */ 964 static const char *spa_feature_names[] = { 965 "org.illumos:lz4_compress", 966 NULL 967 }; 968 969 /* 970 * Checks whether the MOS features that are active are supported by this 971 * (GRUB's) implementation of ZFS. 972 * 973 * Return: 974 * 0: Success. 975 * errnum: Failure. 976 */ 977 static int 978 check_mos_features(dnode_phys_t *mosmdn, char *stack) 979 { 980 uint64_t objnum; 981 dnode_phys_t *dn; 982 uint8_t error = 0; 983 984 dn = (dnode_phys_t *)stack; 985 stack += DNODE_SIZE; 986 987 if ((errnum = dnode_get(mosmdn, DMU_POOL_DIRECTORY_OBJECT, 988 DMU_OT_OBJECT_DIRECTORY, dn, stack)) != 0) 989 return (errnum); 990 991 /* 992 * Find the object number for 'features_for_read' and retrieve its 993 * corresponding dnode. Note that we don't check features_for_write 994 * because GRUB is not opening the pool for write. 995 */ 996 if ((errnum = zap_lookup(dn, DMU_POOL_FEATURES_FOR_READ, &objnum, 997 stack)) != 0) 998 return (errnum); 999 1000 if ((errnum = dnode_get(mosmdn, objnum, DMU_OTN_ZAP_METADATA, 1001 dn, stack)) != 0) 1002 return (errnum); 1003 1004 return (zap_iterate(dn, check_feature, spa_feature_names, stack)); 1005 } 1006 1007 /* 1008 * Given a MOS metadnode, get the metadnode of a given filesystem name (fsname), 1009 * e.g. pool/rootfs, or a given object number (obj), e.g. the object number 1010 * of pool/rootfs. 1011 * 1012 * If no fsname and no obj are given, return the DSL_DIR metadnode. 1013 * If fsname is given, return its metadnode and its matching object number. 1014 * If only obj is given, return the metadnode for this object number. 1015 * 1016 * Return: 1017 * 0 - success 1018 * errnum - failure 1019 */ 1020 static int 1021 get_objset_mdn(dnode_phys_t *mosmdn, char *fsname, uint64_t *obj, 1022 dnode_phys_t *mdn, char *stack) 1023 { 1024 uint64_t objnum, headobj; 1025 char *cname, ch; 1026 blkptr_t *bp; 1027 objset_phys_t *osp; 1028 int issnapshot = 0; 1029 char *snapname; 1030 1031 if (fsname == NULL && obj) { 1032 headobj = *obj; 1033 goto skip; 1034 } 1035 1036 if (errnum = dnode_get(mosmdn, DMU_POOL_DIRECTORY_OBJECT, 1037 DMU_OT_OBJECT_DIRECTORY, mdn, stack)) 1038 return (errnum); 1039 1040 if (errnum = zap_lookup(mdn, DMU_POOL_ROOT_DATASET, &objnum, 1041 stack)) 1042 return (errnum); 1043 1044 if (errnum = dnode_get(mosmdn, objnum, DMU_OT_DSL_DIR, mdn, stack)) 1045 return (errnum); 1046 1047 if (fsname == NULL) { 1048 headobj = 1049 ((dsl_dir_phys_t *)DN_BONUS(mdn))->dd_head_dataset_obj; 1050 goto skip; 1051 } 1052 1053 /* take out the pool name */ 1054 while (*fsname && !grub_isspace(*fsname) && *fsname != '/') 1055 fsname++; 1056 1057 while (*fsname && !grub_isspace(*fsname)) { 1058 uint64_t childobj; 1059 1060 while (*fsname == '/') 1061 fsname++; 1062 1063 cname = fsname; 1064 while (*fsname && !grub_isspace(*fsname) && *fsname != '/') 1065 fsname++; 1066 ch = *fsname; 1067 *fsname = 0; 1068 1069 snapname = cname; 1070 while (*snapname && !grub_isspace(*snapname) && *snapname != 1071 '@') 1072 snapname++; 1073 if (*snapname == '@') { 1074 issnapshot = 1; 1075 *snapname = 0; 1076 } 1077 childobj = 1078 ((dsl_dir_phys_t *)DN_BONUS(mdn))->dd_child_dir_zapobj; 1079 if (errnum = dnode_get(mosmdn, childobj, 1080 DMU_OT_DSL_DIR_CHILD_MAP, mdn, stack)) 1081 return (errnum); 1082 1083 if (zap_lookup(mdn, cname, &objnum, stack)) 1084 return (ERR_FILESYSTEM_NOT_FOUND); 1085 1086 if (errnum = dnode_get(mosmdn, objnum, DMU_OT_DSL_DIR, 1087 mdn, stack)) 1088 return (errnum); 1089 1090 *fsname = ch; 1091 if (issnapshot) 1092 *snapname = '@'; 1093 } 1094 headobj = ((dsl_dir_phys_t *)DN_BONUS(mdn))->dd_head_dataset_obj; 1095 if (obj) 1096 *obj = headobj; 1097 1098 skip: 1099 if (errnum = dnode_get(mosmdn, headobj, DMU_OT_DSL_DATASET, mdn, stack)) 1100 return (errnum); 1101 if (issnapshot) { 1102 uint64_t snapobj; 1103 1104 snapobj = ((dsl_dataset_phys_t *)DN_BONUS(mdn))-> 1105 ds_snapnames_zapobj; 1106 1107 if (errnum = dnode_get(mosmdn, snapobj, 1108 DMU_OT_DSL_DS_SNAP_MAP, mdn, stack)) 1109 return (errnum); 1110 if (zap_lookup(mdn, snapname + 1, &headobj, stack)) 1111 return (ERR_FILESYSTEM_NOT_FOUND); 1112 if (errnum = dnode_get(mosmdn, headobj, 1113 DMU_OT_DSL_DATASET, mdn, stack)) 1114 return (errnum); 1115 if (obj) 1116 *obj = headobj; 1117 } 1118 1119 bp = &((dsl_dataset_phys_t *)DN_BONUS(mdn))->ds_bp; 1120 osp = (objset_phys_t *)stack; 1121 stack += sizeof (objset_phys_t); 1122 if (errnum = zio_read(bp, osp, stack)) 1123 return (errnum); 1124 1125 grub_memmove((char *)mdn, (char *)&osp->os_meta_dnode, DNODE_SIZE); 1126 1127 return (0); 1128 } 1129 1130 /* 1131 * For a given XDR packed nvlist, verify the first 4 bytes and move on. 1132 * 1133 * An XDR packed nvlist is encoded as (comments from nvs_xdr_create) : 1134 * 1135 * encoding method/host endian (4 bytes) 1136 * nvl_version (4 bytes) 1137 * nvl_nvflag (4 bytes) 1138 * encoded nvpairs: 1139 * encoded size of the nvpair (4 bytes) 1140 * decoded size of the nvpair (4 bytes) 1141 * name string size (4 bytes) 1142 * name string data (sizeof(NV_ALIGN4(string)) 1143 * data type (4 bytes) 1144 * # of elements in the nvpair (4 bytes) 1145 * data 1146 * 2 zero's for the last nvpair 1147 * (end of the entire list) (8 bytes) 1148 * 1149 * Return: 1150 * 0 - success 1151 * 1 - failure 1152 */ 1153 static int 1154 nvlist_unpack(char *nvlist, char **out) 1155 { 1156 /* Verify if the 1st and 2nd byte in the nvlist are valid. */ 1157 if (nvlist[0] != NV_ENCODE_XDR || nvlist[1] != HOST_ENDIAN) 1158 return (1); 1159 1160 *out = nvlist + 4; 1161 return (0); 1162 } 1163 1164 static char * 1165 nvlist_array(char *nvlist, int index) 1166 { 1167 int i, encode_size; 1168 1169 for (i = 0; i < index; i++) { 1170 /* skip the header, nvl_version, and nvl_nvflag */ 1171 nvlist = nvlist + 4 * 2; 1172 1173 while (encode_size = BSWAP_32(*(uint32_t *)nvlist)) 1174 nvlist += encode_size; /* goto the next nvpair */ 1175 1176 nvlist = nvlist + 4 * 2; /* skip the ending 2 zeros - 8 bytes */ 1177 } 1178 1179 return (nvlist); 1180 } 1181 1182 /* 1183 * The nvlist_next_nvpair() function returns a handle to the next nvpair in the 1184 * list following nvpair. If nvpair is NULL, the first pair is returned. If 1185 * nvpair is the last pair in the nvlist, NULL is returned. 1186 */ 1187 static char * 1188 nvlist_next_nvpair(char *nvl, char *nvpair) 1189 { 1190 char *cur, *prev; 1191 int encode_size; 1192 1193 if (nvl == NULL) 1194 return (NULL); 1195 1196 if (nvpair == NULL) { 1197 /* skip over nvl_version and nvl_nvflag */ 1198 nvpair = nvl + 4 * 2; 1199 } else { 1200 /* skip to the next nvpair */ 1201 encode_size = BSWAP_32(*(uint32_t *)nvpair); 1202 nvpair += encode_size; 1203 } 1204 1205 /* 8 bytes of 0 marks the end of the list */ 1206 if (*(uint64_t *)nvpair == 0) 1207 return (NULL); 1208 1209 return (nvpair); 1210 } 1211 1212 /* 1213 * This function returns 0 on success and 1 on failure. On success, a string 1214 * containing the name of nvpair is saved in buf. 1215 */ 1216 static int 1217 nvpair_name(char *nvp, char *buf, int buflen) 1218 { 1219 int len; 1220 1221 /* skip over encode/decode size */ 1222 nvp += 4 * 2; 1223 1224 len = BSWAP_32(*(uint32_t *)nvp); 1225 if (buflen < len + 1) 1226 return (1); 1227 1228 grub_memmove(buf, nvp + 4, len); 1229 buf[len] = '\0'; 1230 1231 return (0); 1232 } 1233 1234 /* 1235 * This function retrieves the value of the nvpair in the form of enumerated 1236 * type data_type_t. This is used to determine the appropriate type to pass to 1237 * nvpair_value(). 1238 */ 1239 static int 1240 nvpair_type(char *nvp) 1241 { 1242 int name_len, type; 1243 1244 /* skip over encode/decode size */ 1245 nvp += 4 * 2; 1246 1247 /* skip over name_len */ 1248 name_len = BSWAP_32(*(uint32_t *)nvp); 1249 nvp += 4; 1250 1251 /* skip over name */ 1252 nvp = nvp + ((name_len + 3) & ~3); /* align */ 1253 1254 type = BSWAP_32(*(uint32_t *)nvp); 1255 1256 return (type); 1257 } 1258 1259 static int 1260 nvpair_value(char *nvp, void *val, int valtype, int *nelmp) 1261 { 1262 int name_len, type, slen; 1263 char *strval = val; 1264 uint64_t *intval = val; 1265 1266 /* skip over encode/decode size */ 1267 nvp += 4 * 2; 1268 1269 /* skip over name_len */ 1270 name_len = BSWAP_32(*(uint32_t *)nvp); 1271 nvp += 4; 1272 1273 /* skip over name */ 1274 nvp = nvp + ((name_len + 3) & ~3); /* align */ 1275 1276 /* skip over type */ 1277 type = BSWAP_32(*(uint32_t *)nvp); 1278 nvp += 4; 1279 1280 if (type == valtype) { 1281 int nelm; 1282 1283 nelm = BSWAP_32(*(uint32_t *)nvp); 1284 if (valtype != DATA_TYPE_BOOLEAN && nelm < 1) 1285 return (1); 1286 nvp += 4; 1287 1288 switch (valtype) { 1289 case DATA_TYPE_BOOLEAN: 1290 return (0); 1291 1292 case DATA_TYPE_STRING: 1293 slen = BSWAP_32(*(uint32_t *)nvp); 1294 nvp += 4; 1295 grub_memmove(strval, nvp, slen); 1296 strval[slen] = '\0'; 1297 return (0); 1298 1299 case DATA_TYPE_UINT64: 1300 *intval = BSWAP_64(*(uint64_t *)nvp); 1301 return (0); 1302 1303 case DATA_TYPE_NVLIST: 1304 *(void **)val = (void *)nvp; 1305 return (0); 1306 1307 case DATA_TYPE_NVLIST_ARRAY: 1308 *(void **)val = (void *)nvp; 1309 if (nelmp) 1310 *nelmp = nelm; 1311 return (0); 1312 } 1313 } 1314 1315 return (1); 1316 } 1317 1318 static int 1319 nvlist_lookup_value(char *nvlist, char *name, void *val, int valtype, 1320 int *nelmp) 1321 { 1322 char *nvpair; 1323 1324 for (nvpair = nvlist_next_nvpair(nvlist, NULL); 1325 nvpair != NULL; 1326 nvpair = nvlist_next_nvpair(nvlist, nvpair)) { 1327 int name_len = BSWAP_32(*(uint32_t *)(nvpair + 4 * 2)); 1328 char *nvp_name = nvpair + 4 * 3; 1329 1330 if ((grub_strncmp(nvp_name, name, name_len) == 0) && 1331 nvpair_type(nvpair) == valtype) { 1332 return (nvpair_value(nvpair, val, valtype, nelmp)); 1333 } 1334 } 1335 return (1); 1336 } 1337 1338 /* 1339 * Check if this vdev is online and is in a good state. 1340 */ 1341 static int 1342 vdev_validate(char *nv) 1343 { 1344 uint64_t ival; 1345 1346 if (nvlist_lookup_value(nv, ZPOOL_CONFIG_OFFLINE, &ival, 1347 DATA_TYPE_UINT64, NULL) == 0 || 1348 nvlist_lookup_value(nv, ZPOOL_CONFIG_FAULTED, &ival, 1349 DATA_TYPE_UINT64, NULL) == 0 || 1350 nvlist_lookup_value(nv, ZPOOL_CONFIG_REMOVED, &ival, 1351 DATA_TYPE_UINT64, NULL) == 0) 1352 return (ERR_DEV_VALUES); 1353 1354 return (0); 1355 } 1356 1357 /* 1358 * Get a valid vdev pathname/devid from the boot device. 1359 * The caller should already allocate MAXPATHLEN memory for bootpath and devid. 1360 */ 1361 static int 1362 vdev_get_bootpath(char *nv, uint64_t inguid, char *devid, char *bootpath, 1363 int is_spare) 1364 { 1365 char type[16]; 1366 1367 if (nvlist_lookup_value(nv, ZPOOL_CONFIG_TYPE, &type, DATA_TYPE_STRING, 1368 NULL)) 1369 return (ERR_FSYS_CORRUPT); 1370 1371 if (grub_strcmp(type, VDEV_TYPE_DISK) == 0) { 1372 uint64_t guid; 1373 1374 if (vdev_validate(nv) != 0) 1375 return (ERR_NO_BOOTPATH); 1376 1377 if (nvlist_lookup_value(nv, ZPOOL_CONFIG_GUID, 1378 &guid, DATA_TYPE_UINT64, NULL) != 0) 1379 return (ERR_NO_BOOTPATH); 1380 1381 if (guid != inguid) 1382 return (ERR_NO_BOOTPATH); 1383 1384 /* for a spare vdev, pick the disk labeled with "is_spare" */ 1385 if (is_spare) { 1386 uint64_t spare = 0; 1387 (void) nvlist_lookup_value(nv, ZPOOL_CONFIG_IS_SPARE, 1388 &spare, DATA_TYPE_UINT64, NULL); 1389 if (!spare) 1390 return (ERR_NO_BOOTPATH); 1391 } 1392 1393 if (nvlist_lookup_value(nv, ZPOOL_CONFIG_PHYS_PATH, 1394 bootpath, DATA_TYPE_STRING, NULL) != 0) 1395 bootpath[0] = '\0'; 1396 1397 if (nvlist_lookup_value(nv, ZPOOL_CONFIG_DEVID, 1398 devid, DATA_TYPE_STRING, NULL) != 0) 1399 devid[0] = '\0'; 1400 1401 if (grub_strlen(bootpath) >= MAXPATHLEN || 1402 grub_strlen(devid) >= MAXPATHLEN) 1403 return (ERR_WONT_FIT); 1404 1405 return (0); 1406 1407 } else if (grub_strcmp(type, VDEV_TYPE_MIRROR) == 0 || 1408 grub_strcmp(type, VDEV_TYPE_REPLACING) == 0 || 1409 (is_spare = (grub_strcmp(type, VDEV_TYPE_SPARE) == 0))) { 1410 int nelm, i; 1411 char *child; 1412 1413 if (nvlist_lookup_value(nv, ZPOOL_CONFIG_CHILDREN, &child, 1414 DATA_TYPE_NVLIST_ARRAY, &nelm)) 1415 return (ERR_FSYS_CORRUPT); 1416 1417 for (i = 0; i < nelm; i++) { 1418 char *child_i; 1419 1420 child_i = nvlist_array(child, i); 1421 if (vdev_get_bootpath(child_i, inguid, devid, 1422 bootpath, is_spare) == 0) 1423 return (0); 1424 } 1425 } 1426 1427 return (ERR_NO_BOOTPATH); 1428 } 1429 1430 /* 1431 * Check the disk label information and retrieve needed vdev name-value pairs. 1432 * 1433 * Return: 1434 * 0 - success 1435 * ERR_* - failure 1436 */ 1437 static int 1438 check_pool_label(uint64_t sector, char *stack, char *outdevid, 1439 char *outpath, uint64_t *outguid, uint64_t *outashift, uint64_t *outversion) 1440 { 1441 vdev_phys_t *vdev; 1442 uint64_t pool_state, txg = 0; 1443 char *nvlist, *nv, *features; 1444 uint64_t diskguid; 1445 1446 sector += (VDEV_SKIP_SIZE >> SPA_MINBLOCKSHIFT); 1447 1448 /* Read in the vdev name-value pair list (112K). */ 1449 if (devread(sector, 0, VDEV_PHYS_SIZE, stack) == 0) 1450 return (ERR_READ); 1451 1452 vdev = (vdev_phys_t *)stack; 1453 stack += sizeof (vdev_phys_t); 1454 1455 if (nvlist_unpack(vdev->vp_nvlist, &nvlist)) 1456 return (ERR_FSYS_CORRUPT); 1457 1458 if (nvlist_lookup_value(nvlist, ZPOOL_CONFIG_POOL_STATE, &pool_state, 1459 DATA_TYPE_UINT64, NULL)) 1460 return (ERR_FSYS_CORRUPT); 1461 1462 if (pool_state == POOL_STATE_DESTROYED) 1463 return (ERR_FILESYSTEM_NOT_FOUND); 1464 1465 if (nvlist_lookup_value(nvlist, ZPOOL_CONFIG_POOL_NAME, 1466 current_rootpool, DATA_TYPE_STRING, NULL)) 1467 return (ERR_FSYS_CORRUPT); 1468 1469 if (nvlist_lookup_value(nvlist, ZPOOL_CONFIG_POOL_TXG, &txg, 1470 DATA_TYPE_UINT64, NULL)) 1471 return (ERR_FSYS_CORRUPT); 1472 1473 /* not an active device */ 1474 if (txg == 0) 1475 return (ERR_NO_BOOTPATH); 1476 1477 if (nvlist_lookup_value(nvlist, ZPOOL_CONFIG_VERSION, outversion, 1478 DATA_TYPE_UINT64, NULL)) 1479 return (ERR_FSYS_CORRUPT); 1480 if (!SPA_VERSION_IS_SUPPORTED(*outversion)) 1481 return (ERR_NEWER_VERSION); 1482 if (nvlist_lookup_value(nvlist, ZPOOL_CONFIG_VDEV_TREE, &nv, 1483 DATA_TYPE_NVLIST, NULL)) 1484 return (ERR_FSYS_CORRUPT); 1485 if (nvlist_lookup_value(nvlist, ZPOOL_CONFIG_GUID, &diskguid, 1486 DATA_TYPE_UINT64, NULL)) 1487 return (ERR_FSYS_CORRUPT); 1488 if (nvlist_lookup_value(nv, ZPOOL_CONFIG_ASHIFT, outashift, 1489 DATA_TYPE_UINT64, NULL) != 0) 1490 return (ERR_FSYS_CORRUPT); 1491 if (vdev_get_bootpath(nv, diskguid, outdevid, outpath, 0)) 1492 return (ERR_NO_BOOTPATH); 1493 if (nvlist_lookup_value(nvlist, ZPOOL_CONFIG_POOL_GUID, outguid, 1494 DATA_TYPE_UINT64, NULL)) 1495 return (ERR_FSYS_CORRUPT); 1496 1497 if (nvlist_lookup_value(nvlist, ZPOOL_CONFIG_FEATURES_FOR_READ, 1498 &features, DATA_TYPE_NVLIST, NULL) == 0) { 1499 char *nvp; 1500 char *name = stack; 1501 stack += MAXNAMELEN; 1502 1503 for (nvp = nvlist_next_nvpair(features, NULL); 1504 nvp != NULL; 1505 nvp = nvlist_next_nvpair(features, nvp)) { 1506 zap_attribute_t za; 1507 1508 if (nvpair_name(nvp, name, MAXNAMELEN) != 0) 1509 return (ERR_FSYS_CORRUPT); 1510 1511 za.za_integer_length = 8; 1512 za.za_num_integers = 1; 1513 za.za_first_integer = 1; 1514 za.za_name = name; 1515 if (check_feature(&za, spa_feature_names, stack) != 0) 1516 return (ERR_NEWER_VERSION); 1517 } 1518 } 1519 1520 return (0); 1521 } 1522 1523 /* 1524 * zfs_mount() locates a valid uberblock of the root pool and read in its MOS 1525 * to the memory address MOS. 1526 * 1527 * Return: 1528 * 1 - success 1529 * 0 - failure 1530 */ 1531 int 1532 zfs_mount(void) 1533 { 1534 char *stack, *ub_array; 1535 int label = 0; 1536 uberblock_t *ubbest; 1537 objset_phys_t *osp; 1538 char tmp_bootpath[MAXNAMELEN]; 1539 char tmp_devid[MAXNAMELEN]; 1540 uint64_t tmp_guid, ashift, version; 1541 uint64_t adjpl = (uint64_t)part_length << SPA_MINBLOCKSHIFT; 1542 int err = errnum; /* preserve previous errnum state */ 1543 1544 /* if it's our first time here, zero the best uberblock out */ 1545 if (best_drive == 0 && best_part == 0 && find_best_root) { 1546 grub_memset(¤t_uberblock, 0, sizeof (uberblock_t)); 1547 pool_guid = 0; 1548 } 1549 1550 stackbase = ZFS_SCRATCH; 1551 stack = stackbase; 1552 ub_array = stack; 1553 stack += VDEV_UBERBLOCK_RING; 1554 1555 osp = (objset_phys_t *)stack; 1556 stack += sizeof (objset_phys_t); 1557 adjpl = P2ALIGN(adjpl, (uint64_t)sizeof (vdev_label_t)); 1558 1559 for (label = 0; label < VDEV_LABELS; label++) { 1560 1561 /* 1562 * some eltorito stacks don't give us a size and 1563 * we end up setting the size to MAXUINT, further 1564 * some of these devices stop working once a single 1565 * read past the end has been issued. Checking 1566 * for a maximum part_length and skipping the backup 1567 * labels at the end of the slice/partition/device 1568 * avoids breaking down on such devices. 1569 */ 1570 if (part_length == MAXUINT && label == 2) 1571 break; 1572 1573 uint64_t sector = vdev_label_start(adjpl, 1574 label) >> SPA_MINBLOCKSHIFT; 1575 1576 /* Read in the uberblock ring (128K). */ 1577 if (devread(sector + 1578 ((VDEV_SKIP_SIZE + VDEV_PHYS_SIZE) >> SPA_MINBLOCKSHIFT), 1579 0, VDEV_UBERBLOCK_RING, ub_array) == 0) 1580 continue; 1581 1582 if (check_pool_label(sector, stack, tmp_devid, 1583 tmp_bootpath, &tmp_guid, &ashift, &version)) 1584 continue; 1585 1586 if (pool_guid == 0) 1587 pool_guid = tmp_guid; 1588 1589 if ((ubbest = find_bestub(ub_array, ashift, sector)) == NULL || 1590 zio_read(&ubbest->ub_rootbp, osp, stack) != 0) 1591 continue; 1592 1593 VERIFY_OS_TYPE(osp, DMU_OST_META); 1594 1595 if (version >= SPA_VERSION_FEATURES && 1596 check_mos_features(&osp->os_meta_dnode, stack) != 0) 1597 continue; 1598 1599 if (find_best_root && ((pool_guid != tmp_guid) || 1600 vdev_uberblock_compare(ubbest, &(current_uberblock)) <= 0)) 1601 continue; 1602 1603 /* Got the MOS. Save it at the memory addr MOS. */ 1604 grub_memmove(MOS, &osp->os_meta_dnode, DNODE_SIZE); 1605 grub_memmove(¤t_uberblock, ubbest, sizeof (uberblock_t)); 1606 grub_memmove(current_bootpath, tmp_bootpath, MAXNAMELEN); 1607 grub_memmove(current_devid, tmp_devid, grub_strlen(tmp_devid)); 1608 is_zfs_mount = 1; 1609 return (1); 1610 } 1611 1612 /* 1613 * While some fs impls. (tftp) rely on setting and keeping 1614 * global errnums set, others won't reset it and will break 1615 * when issuing rawreads. The goal here is to simply not 1616 * have zfs mount attempts impact the previous state. 1617 */ 1618 errnum = err; 1619 return (0); 1620 } 1621 1622 /* 1623 * zfs_open() locates a file in the rootpool by following the 1624 * MOS and places the dnode of the file in the memory address DNODE. 1625 * 1626 * Return: 1627 * 1 - success 1628 * 0 - failure 1629 */ 1630 int 1631 zfs_open(char *filename) 1632 { 1633 char *stack; 1634 dnode_phys_t *mdn; 1635 1636 file_buf = NULL; 1637 stackbase = ZFS_SCRATCH; 1638 stack = stackbase; 1639 1640 mdn = (dnode_phys_t *)stack; 1641 stack += sizeof (dnode_phys_t); 1642 1643 dnode_mdn = NULL; 1644 dnode_buf = (dnode_phys_t *)stack; 1645 stack += 1<<DNODE_BLOCK_SHIFT; 1646 1647 /* 1648 * menu.lst is placed at the root pool filesystem level, 1649 * do not goto 'current_bootfs'. 1650 */ 1651 if (is_top_dataset_file(filename)) { 1652 if (errnum = get_objset_mdn(MOS, NULL, NULL, mdn, stack)) 1653 return (0); 1654 1655 current_bootfs_obj = 0; 1656 } else { 1657 if (current_bootfs[0] == '\0') { 1658 /* Get the default root filesystem object number */ 1659 if (errnum = get_default_bootfsobj(MOS, 1660 ¤t_bootfs_obj, stack)) 1661 return (0); 1662 1663 if (errnum = get_objset_mdn(MOS, NULL, 1664 ¤t_bootfs_obj, mdn, stack)) 1665 return (0); 1666 } else { 1667 if (errnum = get_objset_mdn(MOS, current_bootfs, 1668 ¤t_bootfs_obj, mdn, stack)) { 1669 grub_memset(current_bootfs, 0, MAXNAMELEN); 1670 return (0); 1671 } 1672 } 1673 } 1674 1675 if (dnode_get_path(mdn, filename, DNODE, stack)) { 1676 errnum = ERR_FILE_NOT_FOUND; 1677 return (0); 1678 } 1679 1680 /* get the file size and set the file position to 0 */ 1681 1682 /* 1683 * For DMU_OT_SA we will need to locate the SIZE attribute 1684 * attribute, which could be either in the bonus buffer 1685 * or the "spill" block. 1686 */ 1687 if (DNODE->dn_bonustype == DMU_OT_SA) { 1688 sa_hdr_phys_t *sahdrp; 1689 int hdrsize; 1690 1691 if (DNODE->dn_bonuslen != 0) { 1692 sahdrp = (sa_hdr_phys_t *)DN_BONUS(DNODE); 1693 } else { 1694 if (DNODE->dn_flags & DNODE_FLAG_SPILL_BLKPTR) { 1695 blkptr_t *bp = &DNODE->dn_spill; 1696 void *buf; 1697 1698 buf = (void *)stack; 1699 stack += BP_GET_LSIZE(bp); 1700 1701 /* reset errnum to rawread() failure */ 1702 errnum = 0; 1703 if (zio_read(bp, buf, stack) != 0) { 1704 return (0); 1705 } 1706 sahdrp = buf; 1707 } else { 1708 errnum = ERR_FSYS_CORRUPT; 1709 return (0); 1710 } 1711 } 1712 hdrsize = SA_HDR_SIZE(sahdrp); 1713 filemax = *(uint64_t *)((char *)sahdrp + hdrsize + 1714 SA_SIZE_OFFSET); 1715 } else { 1716 filemax = ((znode_phys_t *)DN_BONUS(DNODE))->zp_size; 1717 } 1718 filepos = 0; 1719 1720 dnode_buf = NULL; 1721 return (1); 1722 } 1723 1724 /* 1725 * zfs_read reads in the data blocks pointed by the DNODE. 1726 * 1727 * Return: 1728 * len - the length successfully read in to the buffer 1729 * 0 - failure 1730 */ 1731 int 1732 zfs_read(char *buf, int len) 1733 { 1734 char *stack; 1735 int blksz, length, movesize; 1736 1737 if (file_buf == NULL) { 1738 file_buf = stackbase; 1739 stackbase += SPA_MAXBLOCKSIZE; 1740 file_start = file_end = 0; 1741 } 1742 stack = stackbase; 1743 1744 /* 1745 * If offset is in memory, move it into the buffer provided and return. 1746 */ 1747 if (filepos >= file_start && filepos+len <= file_end) { 1748 grub_memmove(buf, file_buf + filepos - file_start, len); 1749 filepos += len; 1750 return (len); 1751 } 1752 1753 blksz = DNODE->dn_datablkszsec << SPA_MINBLOCKSHIFT; 1754 1755 /* 1756 * Entire Dnode is too big to fit into the space available. We 1757 * will need to read it in chunks. This could be optimized to 1758 * read in as large a chunk as there is space available, but for 1759 * now, this only reads in one data block at a time. 1760 */ 1761 length = len; 1762 while (length) { 1763 /* 1764 * Find requested blkid and the offset within that block. 1765 */ 1766 uint64_t blkid = filepos / blksz; 1767 1768 if (errnum = dmu_read(DNODE, blkid, file_buf, stack)) 1769 return (0); 1770 1771 file_start = blkid * blksz; 1772 file_end = file_start + blksz; 1773 1774 movesize = MIN(length, file_end - filepos); 1775 1776 grub_memmove(buf, file_buf + filepos - file_start, 1777 movesize); 1778 buf += movesize; 1779 length -= movesize; 1780 filepos += movesize; 1781 } 1782 1783 return (len); 1784 } 1785 1786 /* 1787 * No-Op 1788 */ 1789 int 1790 zfs_embed(int *start_sector, int needed_sectors) 1791 { 1792 return (1); 1793 } 1794 1795 #endif /* FSYS_ZFS */ 1796