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) 2013 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 if (byteswap) { 170 grub_printf("byteswap not supported\n"); 171 return (-1); 172 } 173 174 if (checksum >= ZIO_CHECKSUM_FUNCTIONS || ci->ci_func[0] == NULL) { 175 grub_printf("checksum algorithm %u not supported\n", checksum); 176 return (-1); 177 } 178 179 if (ci->ci_eck) { 180 expected_cksum = zec->zec_cksum; 181 zec->zec_cksum = zc; 182 ci->ci_func[0](data, size, &actual_cksum); 183 zec->zec_cksum = expected_cksum; 184 zc = expected_cksum; 185 } else { 186 ci->ci_func[byteswap](data, size, &actual_cksum); 187 } 188 189 if ((actual_cksum.zc_word[0] - zc.zc_word[0]) | 190 (actual_cksum.zc_word[1] - zc.zc_word[1]) | 191 (actual_cksum.zc_word[2] - zc.zc_word[2]) | 192 (actual_cksum.zc_word[3] - zc.zc_word[3])) 193 return (-1); 194 195 return (0); 196 } 197 198 /* 199 * vdev_label_start returns the physical disk offset (in bytes) of 200 * label "l". 201 */ 202 static uint64_t 203 vdev_label_start(uint64_t psize, int l) 204 { 205 return (l * sizeof (vdev_label_t) + (l < VDEV_LABELS / 2 ? 206 0 : psize - VDEV_LABELS * sizeof (vdev_label_t))); 207 } 208 209 /* 210 * vdev_uberblock_compare takes two uberblock structures and returns an integer 211 * indicating the more recent of the two. 212 * Return Value = 1 if ub2 is more recent 213 * Return Value = -1 if ub1 is more recent 214 * The most recent uberblock is determined using its transaction number and 215 * timestamp. The uberblock with the highest transaction number is 216 * considered "newer". If the transaction numbers of the two blocks match, the 217 * timestamps are compared to determine the "newer" of the two. 218 */ 219 static int 220 vdev_uberblock_compare(uberblock_t *ub1, uberblock_t *ub2) 221 { 222 if (ub1->ub_txg < ub2->ub_txg) 223 return (-1); 224 if (ub1->ub_txg > ub2->ub_txg) 225 return (1); 226 227 if (ub1->ub_timestamp < ub2->ub_timestamp) 228 return (-1); 229 if (ub1->ub_timestamp > ub2->ub_timestamp) 230 return (1); 231 232 return (0); 233 } 234 235 /* 236 * Three pieces of information are needed to verify an uberblock: the magic 237 * number, the version number, and the checksum. 238 * 239 * Return: 240 * 0 - Success 241 * -1 - Failure 242 */ 243 static int 244 uberblock_verify(uberblock_t *uber, uint64_t ub_size, uint64_t offset) 245 { 246 blkptr_t bp; 247 248 BP_ZERO(&bp); 249 BP_SET_CHECKSUM(&bp, ZIO_CHECKSUM_LABEL); 250 BP_SET_BYTEORDER(&bp, ZFS_HOST_BYTEORDER); 251 ZIO_SET_CHECKSUM(&bp.blk_cksum, offset, 0, 0, 0); 252 253 if (zio_checksum_verify(&bp, (char *)uber, ub_size) != 0) 254 return (-1); 255 256 if (uber->ub_magic == UBERBLOCK_MAGIC && 257 SPA_VERSION_IS_SUPPORTED(uber->ub_version)) 258 return (0); 259 260 return (-1); 261 } 262 263 /* 264 * Find the best uberblock. 265 * Return: 266 * Success - Pointer to the best uberblock. 267 * Failure - NULL 268 */ 269 static uberblock_t * 270 find_bestub(char *ub_array, uint64_t ashift, uint64_t sector) 271 { 272 uberblock_t *ubbest = NULL; 273 uberblock_t *ubnext; 274 uint64_t offset, ub_size; 275 int i; 276 277 ub_size = VDEV_UBERBLOCK_SIZE(ashift); 278 279 for (i = 0; i < VDEV_UBERBLOCK_COUNT(ashift); i++) { 280 ubnext = (uberblock_t *)ub_array; 281 ub_array += ub_size; 282 offset = (sector << SPA_MINBLOCKSHIFT) + 283 VDEV_UBERBLOCK_OFFSET(ashift, i); 284 285 if (uberblock_verify(ubnext, ub_size, offset) != 0) 286 continue; 287 288 if (ubbest == NULL || 289 vdev_uberblock_compare(ubnext, ubbest) > 0) 290 ubbest = ubnext; 291 } 292 293 return (ubbest); 294 } 295 296 /* 297 * Read a block of data based on the gang block address dva, 298 * and put its data in buf. 299 * 300 * Return: 301 * 0 - success 302 * 1 - failure 303 */ 304 static int 305 zio_read_gang(blkptr_t *bp, dva_t *dva, void *buf, char *stack) 306 { 307 zio_gbh_phys_t *zio_gb; 308 uint64_t offset, sector; 309 blkptr_t tmpbp; 310 int i; 311 312 zio_gb = (zio_gbh_phys_t *)stack; 313 stack += SPA_GANGBLOCKSIZE; 314 offset = DVA_GET_OFFSET(dva); 315 sector = DVA_OFFSET_TO_PHYS_SECTOR(offset); 316 317 /* read in the gang block header */ 318 if (devread(sector, 0, SPA_GANGBLOCKSIZE, (char *)zio_gb) == 0) { 319 grub_printf("failed to read in a gang block header\n"); 320 return (1); 321 } 322 323 /* self checksuming the gang block header */ 324 BP_ZERO(&tmpbp); 325 BP_SET_CHECKSUM(&tmpbp, ZIO_CHECKSUM_GANG_HEADER); 326 BP_SET_BYTEORDER(&tmpbp, ZFS_HOST_BYTEORDER); 327 ZIO_SET_CHECKSUM(&tmpbp.blk_cksum, DVA_GET_VDEV(dva), 328 DVA_GET_OFFSET(dva), bp->blk_birth, 0); 329 if (zio_checksum_verify(&tmpbp, (char *)zio_gb, SPA_GANGBLOCKSIZE)) { 330 grub_printf("failed to checksum a gang block header\n"); 331 return (1); 332 } 333 334 for (i = 0; i < SPA_GBH_NBLKPTRS; i++) { 335 if (BP_IS_HOLE(&zio_gb->zg_blkptr[i])) 336 continue; 337 338 if (zio_read_data(&zio_gb->zg_blkptr[i], buf, stack)) 339 return (1); 340 buf += BP_GET_PSIZE(&zio_gb->zg_blkptr[i]); 341 } 342 343 return (0); 344 } 345 346 /* 347 * Read in a block of raw data to buf. 348 * 349 * Return: 350 * 0 - success 351 * 1 - failure 352 */ 353 static int 354 zio_read_data(blkptr_t *bp, void *buf, char *stack) 355 { 356 int i, psize; 357 358 psize = BP_GET_PSIZE(bp); 359 360 /* pick a good dva from the block pointer */ 361 for (i = 0; i < SPA_DVAS_PER_BP; i++) { 362 uint64_t offset, sector; 363 364 if (bp->blk_dva[i].dva_word[0] == 0 && 365 bp->blk_dva[i].dva_word[1] == 0) 366 continue; 367 368 if (DVA_GET_GANG(&bp->blk_dva[i])) { 369 if (zio_read_gang(bp, &bp->blk_dva[i], buf, stack) == 0) 370 return (0); 371 } else { 372 /* read in a data block */ 373 offset = DVA_GET_OFFSET(&bp->blk_dva[i]); 374 sector = DVA_OFFSET_TO_PHYS_SECTOR(offset); 375 if (devread(sector, 0, psize, buf) != 0) 376 return (0); 377 } 378 } 379 380 return (1); 381 } 382 383 /* 384 * buf must be at least BPE_GET_PSIZE(bp) bytes long (which will never be 385 * more than BPE_PAYLOAD_SIZE bytes). 386 */ 387 static void 388 decode_embedded_bp_compressed(const blkptr_t *bp, void *buf) 389 { 390 int psize, i; 391 uint8_t *buf8 = buf; 392 uint64_t w = 0; 393 const uint64_t *bp64 = (const uint64_t *)bp; 394 395 psize = BPE_GET_PSIZE(bp); 396 397 /* 398 * Decode the words of the block pointer into the byte array. 399 * Low bits of first word are the first byte (little endian). 400 */ 401 for (i = 0; i < psize; i++) { 402 if (i % sizeof (w) == 0) { 403 /* beginning of a word */ 404 w = *bp64; 405 bp64++; 406 if (!BPE_IS_PAYLOADWORD(bp, bp64)) 407 bp64++; 408 } 409 buf8[i] = BF64_GET(w, (i % sizeof (w)) * NBBY, NBBY); 410 } 411 } 412 413 /* 414 * Fill in the buffer with the (decompressed) payload of the embedded 415 * blkptr_t. Takes into account compression and byteorder (the payload is 416 * treated as a stream of bytes). 417 * Return 0 on success, or ENOSPC if it won't fit in the buffer. 418 */ 419 static int 420 decode_embedded_bp(const blkptr_t *bp, void *buf) 421 { 422 int comp; 423 int lsize, psize; 424 uint8_t *dst = buf; 425 uint64_t w = 0; 426 427 lsize = BPE_GET_LSIZE(bp); 428 psize = BPE_GET_PSIZE(bp); 429 comp = BP_GET_COMPRESS(bp); 430 431 if (comp != ZIO_COMPRESS_OFF) { 432 uint8_t dstbuf[BPE_PAYLOAD_SIZE]; 433 434 if ((unsigned int)comp >= ZIO_COMPRESS_FUNCTIONS || 435 decomp_table[comp].decomp_func == NULL) { 436 grub_printf("compression algorithm not supported\n"); 437 return (ERR_FSYS_CORRUPT); 438 } 439 440 decode_embedded_bp_compressed(bp, dstbuf); 441 decomp_table[comp].decomp_func(dstbuf, buf, psize, lsize); 442 } else { 443 decode_embedded_bp_compressed(bp, buf); 444 } 445 446 return (0); 447 } 448 449 /* 450 * Read in a block of data, verify its checksum, decompress if needed, 451 * and put the uncompressed data in buf. 452 * 453 * Return: 454 * 0 - success 455 * errnum - failure 456 */ 457 static int 458 zio_read(blkptr_t *bp, void *buf, char *stack) 459 { 460 int lsize, psize, comp; 461 char *retbuf; 462 463 if (BP_IS_EMBEDDED(bp)) { 464 if (BPE_GET_ETYPE(bp) != BP_EMBEDDED_TYPE_DATA) { 465 grub_printf("unsupported embedded BP (type=%u)\n", 466 (int)BPE_GET_ETYPE(bp)); 467 return (ERR_FSYS_CORRUPT); 468 } 469 return (decode_embedded_bp(bp, buf)); 470 } 471 472 comp = BP_GET_COMPRESS(bp); 473 lsize = BP_GET_LSIZE(bp); 474 psize = BP_GET_PSIZE(bp); 475 476 if ((unsigned int)comp >= ZIO_COMPRESS_FUNCTIONS || 477 (comp != ZIO_COMPRESS_OFF && 478 decomp_table[comp].decomp_func == NULL)) { 479 grub_printf("compression algorithm not supported\n"); 480 return (ERR_FSYS_CORRUPT); 481 } 482 483 if ((char *)buf < stack && ((char *)buf) + lsize > stack) { 484 grub_printf("not enough memory to fit %u bytes on stack\n", 485 lsize); 486 return (ERR_WONT_FIT); 487 } 488 489 retbuf = buf; 490 if (comp != ZIO_COMPRESS_OFF) { 491 buf = stack; 492 stack += psize; 493 } 494 495 if (zio_read_data(bp, buf, stack) != 0) { 496 grub_printf("zio_read_data failed\n"); 497 return (ERR_FSYS_CORRUPT); 498 } 499 500 if (zio_checksum_verify(bp, buf, psize) != 0) { 501 grub_printf("checksum verification failed\n"); 502 return (ERR_FSYS_CORRUPT); 503 } 504 505 if (comp != ZIO_COMPRESS_OFF) { 506 if (decomp_table[comp].decomp_func(buf, retbuf, psize, 507 lsize) != 0) { 508 grub_printf("zio_read decompression failed\n"); 509 return (ERR_FSYS_CORRUPT); 510 } 511 } 512 513 return (0); 514 } 515 516 /* 517 * Get the block from a block id. 518 * push the block onto the stack. 519 * 520 * Return: 521 * 0 - success 522 * errnum - failure 523 */ 524 static int 525 dmu_read(dnode_phys_t *dn, uint64_t blkid, void *buf, char *stack) 526 { 527 int idx, level; 528 blkptr_t *bp_array = dn->dn_blkptr; 529 int epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 530 blkptr_t *bp, *tmpbuf; 531 532 bp = (blkptr_t *)stack; 533 stack += sizeof (blkptr_t); 534 535 tmpbuf = (blkptr_t *)stack; 536 stack += 1<<dn->dn_indblkshift; 537 538 for (level = dn->dn_nlevels - 1; level >= 0; level--) { 539 idx = (blkid >> (epbs * level)) & ((1<<epbs)-1); 540 *bp = bp_array[idx]; 541 if (level == 0) 542 tmpbuf = buf; 543 if (BP_IS_HOLE(bp)) { 544 grub_memset(buf, 0, 545 dn->dn_datablkszsec << SPA_MINBLOCKSHIFT); 546 break; 547 } else if (errnum = zio_read(bp, tmpbuf, stack)) { 548 return (errnum); 549 } 550 551 bp_array = tmpbuf; 552 } 553 554 return (0); 555 } 556 557 /* 558 * mzap_lookup: Looks up property described by "name" and returns the value 559 * in "value". 560 * 561 * Return: 562 * 0 - success 563 * errnum - failure 564 */ 565 static int 566 mzap_lookup(mzap_phys_t *zapobj, int objsize, const char *name, 567 uint64_t *value) 568 { 569 int i, chunks; 570 mzap_ent_phys_t *mzap_ent = zapobj->mz_chunk; 571 572 chunks = objsize / MZAP_ENT_LEN - 1; 573 for (i = 0; i < chunks; i++) { 574 if (grub_strcmp(mzap_ent[i].mze_name, name) == 0) { 575 *value = mzap_ent[i].mze_value; 576 return (0); 577 } 578 } 579 580 return (ERR_FSYS_CORRUPT); 581 } 582 583 static uint64_t 584 zap_hash(uint64_t salt, const char *name) 585 { 586 static uint64_t table[256]; 587 const uint8_t *cp; 588 uint8_t c; 589 uint64_t crc = salt; 590 591 if (table[128] == 0) { 592 uint64_t *ct; 593 int i, j; 594 for (i = 0; i < 256; i++) { 595 for (ct = table + i, *ct = i, j = 8; j > 0; j--) 596 *ct = (*ct >> 1) ^ (-(*ct & 1) & 597 ZFS_CRC64_POLY); 598 } 599 } 600 601 if (crc == 0 || table[128] != ZFS_CRC64_POLY) { 602 errnum = ERR_FSYS_CORRUPT; 603 return (0); 604 } 605 606 for (cp = (const uint8_t *)name; (c = *cp) != '\0'; cp++) 607 crc = (crc >> 8) ^ table[(crc ^ c) & 0xFF]; 608 609 /* 610 * Only use 28 bits, since we need 4 bits in the cookie for the 611 * collision differentiator. We MUST use the high bits, since 612 * those are the ones that we first pay attention to when 613 * choosing the bucket. 614 */ 615 crc &= ~((1ULL << (64 - 28)) - 1); 616 617 return (crc); 618 } 619 620 /* 621 * Only to be used on 8-bit arrays. 622 * array_len is actual len in bytes (not encoded le_value_length). 623 * buf is null-terminated. 624 */ 625 static int 626 zap_leaf_array_equal(zap_leaf_phys_t *l, int blksft, int chunk, 627 int array_len, const char *buf) 628 { 629 int bseen = 0; 630 631 while (bseen < array_len) { 632 struct zap_leaf_array *la = 633 &ZAP_LEAF_CHUNK(l, blksft, chunk).l_array; 634 int toread = MIN(array_len - bseen, ZAP_LEAF_ARRAY_BYTES); 635 636 if (chunk >= ZAP_LEAF_NUMCHUNKS(blksft)) 637 return (0); 638 639 if (zfs_bcmp(la->la_array, buf + bseen, toread) != 0) 640 break; 641 chunk = la->la_next; 642 bseen += toread; 643 } 644 return (bseen == array_len); 645 } 646 647 /* 648 * Given a zap_leaf_phys_t, walk thru the zap leaf chunks to get the 649 * value for the property "name". 650 * 651 * Return: 652 * 0 - success 653 * errnum - failure 654 */ 655 static int 656 zap_leaf_lookup(zap_leaf_phys_t *l, int blksft, uint64_t h, 657 const char *name, uint64_t *value) 658 { 659 uint16_t chunk; 660 struct zap_leaf_entry *le; 661 662 /* Verify if this is a valid leaf block */ 663 if (l->l_hdr.lh_block_type != ZBT_LEAF) 664 return (ERR_FSYS_CORRUPT); 665 if (l->l_hdr.lh_magic != ZAP_LEAF_MAGIC) 666 return (ERR_FSYS_CORRUPT); 667 668 for (chunk = l->l_hash[LEAF_HASH(blksft, h)]; 669 chunk != CHAIN_END; chunk = le->le_next) { 670 671 if (chunk >= ZAP_LEAF_NUMCHUNKS(blksft)) 672 return (ERR_FSYS_CORRUPT); 673 674 le = ZAP_LEAF_ENTRY(l, blksft, chunk); 675 676 /* Verify the chunk entry */ 677 if (le->le_type != ZAP_CHUNK_ENTRY) 678 return (ERR_FSYS_CORRUPT); 679 680 if (le->le_hash != h) 681 continue; 682 683 if (zap_leaf_array_equal(l, blksft, le->le_name_chunk, 684 le->le_name_length, name)) { 685 686 struct zap_leaf_array *la; 687 uint8_t *ip; 688 689 if (le->le_int_size != 8 || le->le_value_length != 1) 690 return (ERR_FSYS_CORRUPT); 691 692 /* get the uint64_t property value */ 693 la = &ZAP_LEAF_CHUNK(l, blksft, 694 le->le_value_chunk).l_array; 695 ip = la->la_array; 696 697 *value = (uint64_t)ip[0] << 56 | (uint64_t)ip[1] << 48 | 698 (uint64_t)ip[2] << 40 | (uint64_t)ip[3] << 32 | 699 (uint64_t)ip[4] << 24 | (uint64_t)ip[5] << 16 | 700 (uint64_t)ip[6] << 8 | (uint64_t)ip[7]; 701 702 return (0); 703 } 704 } 705 706 return (ERR_FSYS_CORRUPT); 707 } 708 709 /* 710 * Fat ZAP lookup 711 * 712 * Return: 713 * 0 - success 714 * errnum - failure 715 */ 716 static int 717 fzap_lookup(dnode_phys_t *zap_dnode, zap_phys_t *zap, 718 const char *name, uint64_t *value, char *stack) 719 { 720 zap_leaf_phys_t *l; 721 uint64_t hash, idx, blkid; 722 int blksft = zfs_log2(zap_dnode->dn_datablkszsec << DNODE_SHIFT); 723 724 /* Verify if this is a fat zap header block */ 725 if (zap->zap_magic != (uint64_t)ZAP_MAGIC || 726 zap->zap_flags != 0) 727 return (ERR_FSYS_CORRUPT); 728 729 hash = zap_hash(zap->zap_salt, name); 730 if (errnum) 731 return (errnum); 732 733 /* get block id from index */ 734 if (zap->zap_ptrtbl.zt_numblks != 0) { 735 /* external pointer tables not supported */ 736 return (ERR_FSYS_CORRUPT); 737 } 738 idx = ZAP_HASH_IDX(hash, zap->zap_ptrtbl.zt_shift); 739 blkid = ((uint64_t *)zap)[idx + (1<<(blksft-3-1))]; 740 741 /* Get the leaf block */ 742 l = (zap_leaf_phys_t *)stack; 743 stack += 1<<blksft; 744 if ((1<<blksft) < sizeof (zap_leaf_phys_t)) 745 return (ERR_FSYS_CORRUPT); 746 if (errnum = dmu_read(zap_dnode, blkid, l, stack)) 747 return (errnum); 748 749 return (zap_leaf_lookup(l, blksft, hash, name, value)); 750 } 751 752 /* 753 * Read in the data of a zap object and find the value for a matching 754 * property name. 755 * 756 * Return: 757 * 0 - success 758 * errnum - failure 759 */ 760 static int 761 zap_lookup(dnode_phys_t *zap_dnode, const char *name, uint64_t *val, 762 char *stack) 763 { 764 uint64_t block_type; 765 int size; 766 void *zapbuf; 767 768 /* Read in the first block of the zap object data. */ 769 zapbuf = stack; 770 size = zap_dnode->dn_datablkszsec << SPA_MINBLOCKSHIFT; 771 stack += size; 772 773 if ((errnum = dmu_read(zap_dnode, 0, zapbuf, stack)) != 0) 774 return (errnum); 775 776 block_type = *((uint64_t *)zapbuf); 777 778 if (block_type == ZBT_MICRO) { 779 return (mzap_lookup(zapbuf, size, name, val)); 780 } else if (block_type == ZBT_HEADER) { 781 /* this is a fat zap */ 782 return (fzap_lookup(zap_dnode, zapbuf, name, 783 val, stack)); 784 } 785 786 return (ERR_FSYS_CORRUPT); 787 } 788 789 typedef struct zap_attribute { 790 int za_integer_length; 791 uint64_t za_num_integers; 792 uint64_t za_first_integer; 793 char *za_name; 794 } zap_attribute_t; 795 796 typedef int (zap_cb_t)(zap_attribute_t *za, void *arg, char *stack); 797 798 static int 799 zap_iterate(dnode_phys_t *zap_dnode, zap_cb_t *cb, void *arg, char *stack) 800 { 801 uint32_t size = zap_dnode->dn_datablkszsec << SPA_MINBLOCKSHIFT; 802 zap_attribute_t za; 803 int i; 804 mzap_phys_t *mzp = (mzap_phys_t *)stack; 805 stack += size; 806 807 if ((errnum = dmu_read(zap_dnode, 0, mzp, stack)) != 0) 808 return (errnum); 809 810 /* 811 * Iteration over fatzap objects has not yet been implemented. 812 * If we encounter a pool in which there are more features for 813 * read than can fit inside a microzap (i.e., more than 2048 814 * features for read), we can add support for fatzap iteration. 815 * For now, fail. 816 */ 817 if (mzp->mz_block_type != ZBT_MICRO) { 818 grub_printf("feature information stored in fatzap, pool " 819 "version not supported\n"); 820 return (1); 821 } 822 823 za.za_integer_length = 8; 824 za.za_num_integers = 1; 825 for (i = 0; i < size / MZAP_ENT_LEN - 1; i++) { 826 mzap_ent_phys_t *mzep = &mzp->mz_chunk[i]; 827 int err; 828 829 za.za_first_integer = mzep->mze_value; 830 za.za_name = mzep->mze_name; 831 err = cb(&za, arg, stack); 832 if (err != 0) 833 return (err); 834 } 835 836 return (0); 837 } 838 839 /* 840 * Get the dnode of an object number from the metadnode of an object set. 841 * 842 * Input 843 * mdn - metadnode to get the object dnode 844 * objnum - object number for the object dnode 845 * type - if nonzero, object must be of this type 846 * buf - data buffer that holds the returning dnode 847 * stack - scratch area 848 * 849 * Return: 850 * 0 - success 851 * errnum - failure 852 */ 853 static int 854 dnode_get(dnode_phys_t *mdn, uint64_t objnum, uint8_t type, dnode_phys_t *buf, 855 char *stack) 856 { 857 uint64_t blkid, blksz; /* the block id this object dnode is in */ 858 int epbs; /* shift of number of dnodes in a block */ 859 int idx; /* index within a block */ 860 dnode_phys_t *dnbuf; 861 862 blksz = mdn->dn_datablkszsec << SPA_MINBLOCKSHIFT; 863 epbs = zfs_log2(blksz) - DNODE_SHIFT; 864 blkid = objnum >> epbs; 865 idx = objnum & ((1<<epbs)-1); 866 867 if (dnode_buf != NULL && dnode_mdn == mdn && 868 objnum >= dnode_start && objnum < dnode_end) { 869 grub_memmove(buf, &dnode_buf[idx], DNODE_SIZE); 870 VERIFY_DN_TYPE(buf, type); 871 return (0); 872 } 873 874 if (dnode_buf && blksz == 1<<DNODE_BLOCK_SHIFT) { 875 dnbuf = dnode_buf; 876 dnode_mdn = mdn; 877 dnode_start = blkid << epbs; 878 dnode_end = (blkid + 1) << epbs; 879 } else { 880 dnbuf = (dnode_phys_t *)stack; 881 stack += blksz; 882 } 883 884 if (errnum = dmu_read(mdn, blkid, (char *)dnbuf, stack)) 885 return (errnum); 886 887 grub_memmove(buf, &dnbuf[idx], DNODE_SIZE); 888 VERIFY_DN_TYPE(buf, type); 889 890 return (0); 891 } 892 893 /* 894 * Check if this is a special file that resides at the top 895 * dataset of the pool. Currently this is the GRUB menu, 896 * boot signature and boot signature backup. 897 * str starts with '/'. 898 */ 899 static int 900 is_top_dataset_file(char *str) 901 { 902 char *tptr; 903 904 if ((tptr = grub_strstr(str, "menu.lst")) && 905 (tptr[8] == '\0' || tptr[8] == ' ') && 906 *(tptr-1) == '/') 907 return (1); 908 909 if (grub_strncmp(str, BOOTSIGN_DIR"/", 910 grub_strlen(BOOTSIGN_DIR) + 1) == 0) 911 return (1); 912 913 if (grub_strcmp(str, BOOTSIGN_BACKUP) == 0) 914 return (1); 915 916 return (0); 917 } 918 919 static int 920 check_feature(zap_attribute_t *za, void *arg, char *stack) 921 { 922 const char **names = arg; 923 int i; 924 925 if (za->za_first_integer == 0) 926 return (0); 927 928 for (i = 0; names[i] != NULL; i++) { 929 if (grub_strcmp(za->za_name, names[i]) == 0) { 930 return (0); 931 } 932 } 933 grub_printf("missing feature for read '%s'\n", za->za_name); 934 return (ERR_NEWER_VERSION); 935 } 936 937 /* 938 * Get the file dnode for a given file name where mdn is the meta dnode 939 * for this ZFS object set. When found, place the file dnode in dn. 940 * The 'path' argument will be mangled. 941 * 942 * Return: 943 * 0 - success 944 * errnum - failure 945 */ 946 static int 947 dnode_get_path(dnode_phys_t *mdn, char *path, dnode_phys_t *dn, 948 char *stack) 949 { 950 uint64_t objnum, version; 951 char *cname, ch; 952 953 if (errnum = dnode_get(mdn, MASTER_NODE_OBJ, DMU_OT_MASTER_NODE, 954 dn, stack)) 955 return (errnum); 956 957 if (errnum = zap_lookup(dn, ZPL_VERSION_STR, &version, stack)) 958 return (errnum); 959 if (version > ZPL_VERSION) 960 return (-1); 961 962 if (errnum = zap_lookup(dn, ZFS_ROOT_OBJ, &objnum, stack)) 963 return (errnum); 964 965 if (errnum = dnode_get(mdn, objnum, DMU_OT_DIRECTORY_CONTENTS, 966 dn, stack)) 967 return (errnum); 968 969 /* skip leading slashes */ 970 while (*path == '/') 971 path++; 972 973 while (*path && !grub_isspace(*path)) { 974 975 /* get the next component name */ 976 cname = path; 977 while (*path && !grub_isspace(*path) && *path != '/') 978 path++; 979 ch = *path; 980 *path = 0; /* ensure null termination */ 981 982 if (errnum = zap_lookup(dn, cname, &objnum, stack)) 983 return (errnum); 984 985 objnum = ZFS_DIRENT_OBJ(objnum); 986 if (errnum = dnode_get(mdn, objnum, 0, dn, stack)) 987 return (errnum); 988 989 *path = ch; 990 while (*path == '/') 991 path++; 992 } 993 994 /* We found the dnode for this file. Verify if it is a plain file. */ 995 VERIFY_DN_TYPE(dn, DMU_OT_PLAIN_FILE_CONTENTS); 996 997 return (0); 998 } 999 1000 /* 1001 * Get the default 'bootfs' property value from the rootpool. 1002 * 1003 * Return: 1004 * 0 - success 1005 * errnum -failure 1006 */ 1007 static int 1008 get_default_bootfsobj(dnode_phys_t *mosmdn, uint64_t *obj, char *stack) 1009 { 1010 uint64_t objnum = 0; 1011 dnode_phys_t *dn = (dnode_phys_t *)stack; 1012 stack += DNODE_SIZE; 1013 1014 if (errnum = dnode_get(mosmdn, DMU_POOL_DIRECTORY_OBJECT, 1015 DMU_OT_OBJECT_DIRECTORY, dn, stack)) 1016 return (errnum); 1017 1018 /* 1019 * find the object number for 'pool_props', and get the dnode 1020 * of the 'pool_props'. 1021 */ 1022 if (zap_lookup(dn, DMU_POOL_PROPS, &objnum, stack)) 1023 return (ERR_FILESYSTEM_NOT_FOUND); 1024 1025 if (errnum = dnode_get(mosmdn, objnum, DMU_OT_POOL_PROPS, dn, stack)) 1026 return (errnum); 1027 1028 if (zap_lookup(dn, ZPOOL_PROP_BOOTFS, &objnum, stack)) 1029 return (ERR_FILESYSTEM_NOT_FOUND); 1030 1031 if (!objnum) 1032 return (ERR_FILESYSTEM_NOT_FOUND); 1033 1034 *obj = objnum; 1035 return (0); 1036 } 1037 1038 /* 1039 * List of pool features that the grub implementation of ZFS supports for 1040 * read. Note that features that are only required for write do not need 1041 * to be listed here since grub opens pools in read-only mode. 1042 * 1043 * When this list is updated the version number in usr/src/grub/capability 1044 * must be incremented to ensure the new grub gets installed. 1045 */ 1046 static const char *spa_feature_names[] = { 1047 "org.illumos:lz4_compress", 1048 "com.delphix:hole_birth", 1049 "com.delphix:extensible_dataset", 1050 "com.delphix:embedded_data", 1051 NULL 1052 }; 1053 1054 /* 1055 * Checks whether the MOS features that are active are supported by this 1056 * (GRUB's) implementation of ZFS. 1057 * 1058 * Return: 1059 * 0: Success. 1060 * errnum: Failure. 1061 */ 1062 static int 1063 check_mos_features(dnode_phys_t *mosmdn, char *stack) 1064 { 1065 uint64_t objnum; 1066 dnode_phys_t *dn; 1067 uint8_t error = 0; 1068 1069 dn = (dnode_phys_t *)stack; 1070 stack += DNODE_SIZE; 1071 1072 if ((errnum = dnode_get(mosmdn, DMU_POOL_DIRECTORY_OBJECT, 1073 DMU_OT_OBJECT_DIRECTORY, dn, stack)) != 0) 1074 return (errnum); 1075 1076 /* 1077 * Find the object number for 'features_for_read' and retrieve its 1078 * corresponding dnode. Note that we don't check features_for_write 1079 * because GRUB is not opening the pool for write. 1080 */ 1081 if ((errnum = zap_lookup(dn, DMU_POOL_FEATURES_FOR_READ, &objnum, 1082 stack)) != 0) 1083 return (errnum); 1084 1085 if ((errnum = dnode_get(mosmdn, objnum, DMU_OTN_ZAP_METADATA, 1086 dn, stack)) != 0) 1087 return (errnum); 1088 1089 return (zap_iterate(dn, check_feature, spa_feature_names, stack)); 1090 } 1091 1092 /* 1093 * Given a MOS metadnode, get the metadnode of a given filesystem name (fsname), 1094 * e.g. pool/rootfs, or a given object number (obj), e.g. the object number 1095 * of pool/rootfs. 1096 * 1097 * If no fsname and no obj are given, return the DSL_DIR metadnode. 1098 * If fsname is given, return its metadnode and its matching object number. 1099 * If only obj is given, return the metadnode for this object number. 1100 * 1101 * Return: 1102 * 0 - success 1103 * errnum - failure 1104 */ 1105 static int 1106 get_objset_mdn(dnode_phys_t *mosmdn, char *fsname, uint64_t *obj, 1107 dnode_phys_t *mdn, char *stack) 1108 { 1109 uint64_t objnum, headobj; 1110 char *cname, ch; 1111 blkptr_t *bp; 1112 objset_phys_t *osp; 1113 int issnapshot = 0; 1114 char *snapname; 1115 1116 if (fsname == NULL && obj) { 1117 headobj = *obj; 1118 goto skip; 1119 } 1120 1121 if (errnum = dnode_get(mosmdn, DMU_POOL_DIRECTORY_OBJECT, 1122 DMU_OT_OBJECT_DIRECTORY, mdn, stack)) 1123 return (errnum); 1124 1125 if (errnum = zap_lookup(mdn, DMU_POOL_ROOT_DATASET, &objnum, 1126 stack)) 1127 return (errnum); 1128 1129 if (errnum = dnode_get(mosmdn, objnum, 0, mdn, stack)) 1130 return (errnum); 1131 1132 if (fsname == NULL) { 1133 headobj = 1134 ((dsl_dir_phys_t *)DN_BONUS(mdn))->dd_head_dataset_obj; 1135 goto skip; 1136 } 1137 1138 /* take out the pool name */ 1139 while (*fsname && !grub_isspace(*fsname) && *fsname != '/') 1140 fsname++; 1141 1142 while (*fsname && !grub_isspace(*fsname)) { 1143 uint64_t childobj; 1144 1145 while (*fsname == '/') 1146 fsname++; 1147 1148 cname = fsname; 1149 while (*fsname && !grub_isspace(*fsname) && *fsname != '/') 1150 fsname++; 1151 ch = *fsname; 1152 *fsname = 0; 1153 1154 snapname = cname; 1155 while (*snapname && !grub_isspace(*snapname) && *snapname != 1156 '@') 1157 snapname++; 1158 if (*snapname == '@') { 1159 issnapshot = 1; 1160 *snapname = 0; 1161 } 1162 childobj = 1163 ((dsl_dir_phys_t *)DN_BONUS(mdn))->dd_child_dir_zapobj; 1164 if (errnum = dnode_get(mosmdn, childobj, 1165 DMU_OT_DSL_DIR_CHILD_MAP, mdn, stack)) 1166 return (errnum); 1167 1168 if (zap_lookup(mdn, cname, &objnum, stack)) 1169 return (ERR_FILESYSTEM_NOT_FOUND); 1170 1171 if (errnum = dnode_get(mosmdn, objnum, 0, 1172 mdn, stack)) 1173 return (errnum); 1174 1175 *fsname = ch; 1176 if (issnapshot) 1177 *snapname = '@'; 1178 } 1179 headobj = ((dsl_dir_phys_t *)DN_BONUS(mdn))->dd_head_dataset_obj; 1180 if (obj) 1181 *obj = headobj; 1182 1183 skip: 1184 if (errnum = dnode_get(mosmdn, headobj, 0, mdn, stack)) 1185 return (errnum); 1186 if (issnapshot) { 1187 uint64_t snapobj; 1188 1189 snapobj = ((dsl_dataset_phys_t *)DN_BONUS(mdn))-> 1190 ds_snapnames_zapobj; 1191 1192 if (errnum = dnode_get(mosmdn, snapobj, 1193 DMU_OT_DSL_DS_SNAP_MAP, mdn, stack)) 1194 return (errnum); 1195 if (zap_lookup(mdn, snapname + 1, &headobj, stack)) 1196 return (ERR_FILESYSTEM_NOT_FOUND); 1197 if (errnum = dnode_get(mosmdn, headobj, 0, mdn, stack)) 1198 return (errnum); 1199 if (obj) 1200 *obj = headobj; 1201 } 1202 1203 bp = &((dsl_dataset_phys_t *)DN_BONUS(mdn))->ds_bp; 1204 osp = (objset_phys_t *)stack; 1205 stack += sizeof (objset_phys_t); 1206 if (errnum = zio_read(bp, osp, stack)) 1207 return (errnum); 1208 1209 grub_memmove((char *)mdn, (char *)&osp->os_meta_dnode, DNODE_SIZE); 1210 1211 return (0); 1212 } 1213 1214 /* 1215 * For a given XDR packed nvlist, verify the first 4 bytes and move on. 1216 * 1217 * An XDR packed nvlist is encoded as (comments from nvs_xdr_create) : 1218 * 1219 * encoding method/host endian (4 bytes) 1220 * nvl_version (4 bytes) 1221 * nvl_nvflag (4 bytes) 1222 * encoded nvpairs: 1223 * encoded size of the nvpair (4 bytes) 1224 * decoded size of the nvpair (4 bytes) 1225 * name string size (4 bytes) 1226 * name string data (sizeof(NV_ALIGN4(string)) 1227 * data type (4 bytes) 1228 * # of elements in the nvpair (4 bytes) 1229 * data 1230 * 2 zero's for the last nvpair 1231 * (end of the entire list) (8 bytes) 1232 * 1233 * Return: 1234 * 0 - success 1235 * 1 - failure 1236 */ 1237 static int 1238 nvlist_unpack(char *nvlist, char **out) 1239 { 1240 /* Verify if the 1st and 2nd byte in the nvlist are valid. */ 1241 if (nvlist[0] != NV_ENCODE_XDR || nvlist[1] != HOST_ENDIAN) 1242 return (1); 1243 1244 *out = nvlist + 4; 1245 return (0); 1246 } 1247 1248 static char * 1249 nvlist_array(char *nvlist, int index) 1250 { 1251 int i, encode_size; 1252 1253 for (i = 0; i < index; i++) { 1254 /* skip the header, nvl_version, and nvl_nvflag */ 1255 nvlist = nvlist + 4 * 2; 1256 1257 while (encode_size = BSWAP_32(*(uint32_t *)nvlist)) 1258 nvlist += encode_size; /* goto the next nvpair */ 1259 1260 nvlist = nvlist + 4 * 2; /* skip the ending 2 zeros - 8 bytes */ 1261 } 1262 1263 return (nvlist); 1264 } 1265 1266 /* 1267 * The nvlist_next_nvpair() function returns a handle to the next nvpair in the 1268 * list following nvpair. If nvpair is NULL, the first pair is returned. If 1269 * nvpair is the last pair in the nvlist, NULL is returned. 1270 */ 1271 static char * 1272 nvlist_next_nvpair(char *nvl, char *nvpair) 1273 { 1274 char *cur, *prev; 1275 int encode_size; 1276 1277 if (nvl == NULL) 1278 return (NULL); 1279 1280 if (nvpair == NULL) { 1281 /* skip over nvl_version and nvl_nvflag */ 1282 nvpair = nvl + 4 * 2; 1283 } else { 1284 /* skip to the next nvpair */ 1285 encode_size = BSWAP_32(*(uint32_t *)nvpair); 1286 nvpair += encode_size; 1287 } 1288 1289 /* 8 bytes of 0 marks the end of the list */ 1290 if (*(uint64_t *)nvpair == 0) 1291 return (NULL); 1292 1293 return (nvpair); 1294 } 1295 1296 /* 1297 * This function returns 0 on success and 1 on failure. On success, a string 1298 * containing the name of nvpair is saved in buf. 1299 */ 1300 static int 1301 nvpair_name(char *nvp, char *buf, int buflen) 1302 { 1303 int len; 1304 1305 /* skip over encode/decode size */ 1306 nvp += 4 * 2; 1307 1308 len = BSWAP_32(*(uint32_t *)nvp); 1309 if (buflen < len + 1) 1310 return (1); 1311 1312 grub_memmove(buf, nvp + 4, len); 1313 buf[len] = '\0'; 1314 1315 return (0); 1316 } 1317 1318 /* 1319 * This function retrieves the value of the nvpair in the form of enumerated 1320 * type data_type_t. This is used to determine the appropriate type to pass to 1321 * nvpair_value(). 1322 */ 1323 static int 1324 nvpair_type(char *nvp) 1325 { 1326 int name_len, type; 1327 1328 /* skip over encode/decode size */ 1329 nvp += 4 * 2; 1330 1331 /* skip over name_len */ 1332 name_len = BSWAP_32(*(uint32_t *)nvp); 1333 nvp += 4; 1334 1335 /* skip over name */ 1336 nvp = nvp + ((name_len + 3) & ~3); /* align */ 1337 1338 type = BSWAP_32(*(uint32_t *)nvp); 1339 1340 return (type); 1341 } 1342 1343 static int 1344 nvpair_value(char *nvp, void *val, int valtype, int *nelmp) 1345 { 1346 int name_len, type, slen; 1347 char *strval = val; 1348 uint64_t *intval = val; 1349 1350 /* skip over encode/decode size */ 1351 nvp += 4 * 2; 1352 1353 /* skip over name_len */ 1354 name_len = BSWAP_32(*(uint32_t *)nvp); 1355 nvp += 4; 1356 1357 /* skip over name */ 1358 nvp = nvp + ((name_len + 3) & ~3); /* align */ 1359 1360 /* skip over type */ 1361 type = BSWAP_32(*(uint32_t *)nvp); 1362 nvp += 4; 1363 1364 if (type == valtype) { 1365 int nelm; 1366 1367 nelm = BSWAP_32(*(uint32_t *)nvp); 1368 if (valtype != DATA_TYPE_BOOLEAN && nelm < 1) 1369 return (1); 1370 nvp += 4; 1371 1372 switch (valtype) { 1373 case DATA_TYPE_BOOLEAN: 1374 return (0); 1375 1376 case DATA_TYPE_STRING: 1377 slen = BSWAP_32(*(uint32_t *)nvp); 1378 nvp += 4; 1379 grub_memmove(strval, nvp, slen); 1380 strval[slen] = '\0'; 1381 return (0); 1382 1383 case DATA_TYPE_UINT64: 1384 *intval = BSWAP_64(*(uint64_t *)nvp); 1385 return (0); 1386 1387 case DATA_TYPE_NVLIST: 1388 *(void **)val = (void *)nvp; 1389 return (0); 1390 1391 case DATA_TYPE_NVLIST_ARRAY: 1392 *(void **)val = (void *)nvp; 1393 if (nelmp) 1394 *nelmp = nelm; 1395 return (0); 1396 } 1397 } 1398 1399 return (1); 1400 } 1401 1402 static int 1403 nvlist_lookup_value(char *nvlist, char *name, void *val, int valtype, 1404 int *nelmp) 1405 { 1406 char *nvpair; 1407 1408 for (nvpair = nvlist_next_nvpair(nvlist, NULL); 1409 nvpair != NULL; 1410 nvpair = nvlist_next_nvpair(nvlist, nvpair)) { 1411 int name_len = BSWAP_32(*(uint32_t *)(nvpair + 4 * 2)); 1412 char *nvp_name = nvpair + 4 * 3; 1413 1414 if ((grub_strncmp(nvp_name, name, name_len) == 0) && 1415 nvpair_type(nvpair) == valtype) { 1416 return (nvpair_value(nvpair, val, valtype, nelmp)); 1417 } 1418 } 1419 return (1); 1420 } 1421 1422 /* 1423 * Check if this vdev is online and is in a good state. 1424 */ 1425 static int 1426 vdev_validate(char *nv) 1427 { 1428 uint64_t ival; 1429 1430 if (nvlist_lookup_value(nv, ZPOOL_CONFIG_OFFLINE, &ival, 1431 DATA_TYPE_UINT64, NULL) == 0 || 1432 nvlist_lookup_value(nv, ZPOOL_CONFIG_FAULTED, &ival, 1433 DATA_TYPE_UINT64, NULL) == 0 || 1434 nvlist_lookup_value(nv, ZPOOL_CONFIG_REMOVED, &ival, 1435 DATA_TYPE_UINT64, NULL) == 0) 1436 return (ERR_DEV_VALUES); 1437 1438 return (0); 1439 } 1440 1441 /* 1442 * Get a valid vdev pathname/devid from the boot device. 1443 * The caller should already allocate MAXPATHLEN memory for bootpath and devid. 1444 */ 1445 static int 1446 vdev_get_bootpath(char *nv, uint64_t inguid, char *devid, char *bootpath, 1447 int is_spare) 1448 { 1449 char type[16]; 1450 1451 if (nvlist_lookup_value(nv, ZPOOL_CONFIG_TYPE, &type, DATA_TYPE_STRING, 1452 NULL)) 1453 return (ERR_FSYS_CORRUPT); 1454 1455 if (grub_strcmp(type, VDEV_TYPE_DISK) == 0) { 1456 uint64_t guid; 1457 1458 if (vdev_validate(nv) != 0) 1459 return (ERR_NO_BOOTPATH); 1460 1461 if (nvlist_lookup_value(nv, ZPOOL_CONFIG_GUID, 1462 &guid, DATA_TYPE_UINT64, NULL) != 0) 1463 return (ERR_NO_BOOTPATH); 1464 1465 if (guid != inguid) 1466 return (ERR_NO_BOOTPATH); 1467 1468 /* for a spare vdev, pick the disk labeled with "is_spare" */ 1469 if (is_spare) { 1470 uint64_t spare = 0; 1471 (void) nvlist_lookup_value(nv, ZPOOL_CONFIG_IS_SPARE, 1472 &spare, DATA_TYPE_UINT64, NULL); 1473 if (!spare) 1474 return (ERR_NO_BOOTPATH); 1475 } 1476 1477 if (nvlist_lookup_value(nv, ZPOOL_CONFIG_PHYS_PATH, 1478 bootpath, DATA_TYPE_STRING, NULL) != 0) 1479 bootpath[0] = '\0'; 1480 1481 if (nvlist_lookup_value(nv, ZPOOL_CONFIG_DEVID, 1482 devid, DATA_TYPE_STRING, NULL) != 0) 1483 devid[0] = '\0'; 1484 1485 if (grub_strlen(bootpath) >= MAXPATHLEN || 1486 grub_strlen(devid) >= MAXPATHLEN) 1487 return (ERR_WONT_FIT); 1488 1489 return (0); 1490 1491 } else if (grub_strcmp(type, VDEV_TYPE_MIRROR) == 0 || 1492 grub_strcmp(type, VDEV_TYPE_REPLACING) == 0 || 1493 (is_spare = (grub_strcmp(type, VDEV_TYPE_SPARE) == 0))) { 1494 int nelm, i; 1495 char *child; 1496 1497 if (nvlist_lookup_value(nv, ZPOOL_CONFIG_CHILDREN, &child, 1498 DATA_TYPE_NVLIST_ARRAY, &nelm)) 1499 return (ERR_FSYS_CORRUPT); 1500 1501 for (i = 0; i < nelm; i++) { 1502 char *child_i; 1503 1504 child_i = nvlist_array(child, i); 1505 if (vdev_get_bootpath(child_i, inguid, devid, 1506 bootpath, is_spare) == 0) 1507 return (0); 1508 } 1509 } 1510 1511 return (ERR_NO_BOOTPATH); 1512 } 1513 1514 /* 1515 * Check the disk label information and retrieve needed vdev name-value pairs. 1516 * 1517 * Return: 1518 * 0 - success 1519 * ERR_* - failure 1520 */ 1521 static int 1522 check_pool_label(uint64_t sector, char *stack, char *outdevid, 1523 char *outpath, uint64_t *outguid, uint64_t *outashift, uint64_t *outversion) 1524 { 1525 vdev_phys_t *vdev; 1526 uint64_t pool_state, txg = 0; 1527 char *nvlist, *nv, *features; 1528 uint64_t diskguid; 1529 1530 sector += (VDEV_SKIP_SIZE >> SPA_MINBLOCKSHIFT); 1531 1532 /* Read in the vdev name-value pair list (112K). */ 1533 if (devread(sector, 0, VDEV_PHYS_SIZE, stack) == 0) 1534 return (ERR_READ); 1535 1536 vdev = (vdev_phys_t *)stack; 1537 stack += sizeof (vdev_phys_t); 1538 1539 if (nvlist_unpack(vdev->vp_nvlist, &nvlist)) 1540 return (ERR_FSYS_CORRUPT); 1541 1542 if (nvlist_lookup_value(nvlist, ZPOOL_CONFIG_POOL_STATE, &pool_state, 1543 DATA_TYPE_UINT64, NULL)) 1544 return (ERR_FSYS_CORRUPT); 1545 1546 if (pool_state == POOL_STATE_DESTROYED) 1547 return (ERR_FILESYSTEM_NOT_FOUND); 1548 1549 if (nvlist_lookup_value(nvlist, ZPOOL_CONFIG_POOL_NAME, 1550 current_rootpool, DATA_TYPE_STRING, NULL)) 1551 return (ERR_FSYS_CORRUPT); 1552 1553 if (nvlist_lookup_value(nvlist, ZPOOL_CONFIG_POOL_TXG, &txg, 1554 DATA_TYPE_UINT64, NULL)) 1555 return (ERR_FSYS_CORRUPT); 1556 1557 /* not an active device */ 1558 if (txg == 0) 1559 return (ERR_NO_BOOTPATH); 1560 1561 if (nvlist_lookup_value(nvlist, ZPOOL_CONFIG_VERSION, outversion, 1562 DATA_TYPE_UINT64, NULL)) 1563 return (ERR_FSYS_CORRUPT); 1564 if (!SPA_VERSION_IS_SUPPORTED(*outversion)) 1565 return (ERR_NEWER_VERSION); 1566 if (nvlist_lookup_value(nvlist, ZPOOL_CONFIG_VDEV_TREE, &nv, 1567 DATA_TYPE_NVLIST, NULL)) 1568 return (ERR_FSYS_CORRUPT); 1569 if (nvlist_lookup_value(nvlist, ZPOOL_CONFIG_GUID, &diskguid, 1570 DATA_TYPE_UINT64, NULL)) 1571 return (ERR_FSYS_CORRUPT); 1572 if (nvlist_lookup_value(nv, ZPOOL_CONFIG_ASHIFT, outashift, 1573 DATA_TYPE_UINT64, NULL) != 0) 1574 return (ERR_FSYS_CORRUPT); 1575 if (vdev_get_bootpath(nv, diskguid, outdevid, outpath, 0)) 1576 return (ERR_NO_BOOTPATH); 1577 if (nvlist_lookup_value(nvlist, ZPOOL_CONFIG_POOL_GUID, outguid, 1578 DATA_TYPE_UINT64, NULL)) 1579 return (ERR_FSYS_CORRUPT); 1580 1581 if (nvlist_lookup_value(nvlist, ZPOOL_CONFIG_FEATURES_FOR_READ, 1582 &features, DATA_TYPE_NVLIST, NULL) == 0) { 1583 char *nvp; 1584 char *name = stack; 1585 stack += MAXNAMELEN; 1586 1587 for (nvp = nvlist_next_nvpair(features, NULL); 1588 nvp != NULL; 1589 nvp = nvlist_next_nvpair(features, nvp)) { 1590 zap_attribute_t za; 1591 1592 if (nvpair_name(nvp, name, MAXNAMELEN) != 0) 1593 return (ERR_FSYS_CORRUPT); 1594 1595 za.za_integer_length = 8; 1596 za.za_num_integers = 1; 1597 za.za_first_integer = 1; 1598 za.za_name = name; 1599 if (check_feature(&za, spa_feature_names, stack) != 0) 1600 return (ERR_NEWER_VERSION); 1601 } 1602 } 1603 1604 return (0); 1605 } 1606 1607 /* 1608 * zfs_mount() locates a valid uberblock of the root pool and read in its MOS 1609 * to the memory address MOS. 1610 * 1611 * Return: 1612 * 1 - success 1613 * 0 - failure 1614 */ 1615 int 1616 zfs_mount(void) 1617 { 1618 char *stack, *ub_array; 1619 int label = 0; 1620 uberblock_t *ubbest; 1621 objset_phys_t *osp; 1622 char tmp_bootpath[MAXNAMELEN]; 1623 char tmp_devid[MAXNAMELEN]; 1624 uint64_t tmp_guid, ashift, version; 1625 uint64_t adjpl = (uint64_t)part_length << SPA_MINBLOCKSHIFT; 1626 int err = errnum; /* preserve previous errnum state */ 1627 1628 /* if it's our first time here, zero the best uberblock out */ 1629 if (best_drive == 0 && best_part == 0 && find_best_root) { 1630 grub_memset(¤t_uberblock, 0, sizeof (uberblock_t)); 1631 pool_guid = 0; 1632 } 1633 1634 stackbase = ZFS_SCRATCH; 1635 stack = stackbase; 1636 ub_array = stack; 1637 stack += VDEV_UBERBLOCK_RING; 1638 1639 osp = (objset_phys_t *)stack; 1640 stack += sizeof (objset_phys_t); 1641 adjpl = P2ALIGN(adjpl, (uint64_t)sizeof (vdev_label_t)); 1642 1643 for (label = 0; label < VDEV_LABELS; label++) { 1644 1645 /* 1646 * some eltorito stacks don't give us a size and 1647 * we end up setting the size to MAXUINT, further 1648 * some of these devices stop working once a single 1649 * read past the end has been issued. Checking 1650 * for a maximum part_length and skipping the backup 1651 * labels at the end of the slice/partition/device 1652 * avoids breaking down on such devices. 1653 */ 1654 if (part_length == MAXUINT && label == 2) 1655 break; 1656 1657 uint64_t sector = vdev_label_start(adjpl, 1658 label) >> SPA_MINBLOCKSHIFT; 1659 1660 /* Read in the uberblock ring (128K). */ 1661 if (devread(sector + 1662 ((VDEV_SKIP_SIZE + VDEV_PHYS_SIZE) >> SPA_MINBLOCKSHIFT), 1663 0, VDEV_UBERBLOCK_RING, ub_array) == 0) 1664 continue; 1665 1666 if (check_pool_label(sector, stack, tmp_devid, 1667 tmp_bootpath, &tmp_guid, &ashift, &version)) 1668 continue; 1669 1670 if (pool_guid == 0) 1671 pool_guid = tmp_guid; 1672 1673 if ((ubbest = find_bestub(ub_array, ashift, sector)) == NULL || 1674 zio_read(&ubbest->ub_rootbp, osp, stack) != 0) 1675 continue; 1676 1677 VERIFY_OS_TYPE(osp, DMU_OST_META); 1678 1679 if (version >= SPA_VERSION_FEATURES && 1680 check_mos_features(&osp->os_meta_dnode, stack) != 0) 1681 continue; 1682 1683 if (find_best_root && ((pool_guid != tmp_guid) || 1684 vdev_uberblock_compare(ubbest, &(current_uberblock)) <= 0)) 1685 continue; 1686 1687 /* Got the MOS. Save it at the memory addr MOS. */ 1688 grub_memmove(MOS, &osp->os_meta_dnode, DNODE_SIZE); 1689 grub_memmove(¤t_uberblock, ubbest, sizeof (uberblock_t)); 1690 grub_memmove(current_bootpath, tmp_bootpath, MAXNAMELEN); 1691 grub_memmove(current_devid, tmp_devid, grub_strlen(tmp_devid)); 1692 is_zfs_mount = 1; 1693 return (1); 1694 } 1695 1696 /* 1697 * While some fs impls. (tftp) rely on setting and keeping 1698 * global errnums set, others won't reset it and will break 1699 * when issuing rawreads. The goal here is to simply not 1700 * have zfs mount attempts impact the previous state. 1701 */ 1702 errnum = err; 1703 return (0); 1704 } 1705 1706 /* 1707 * zfs_open() locates a file in the rootpool by following the 1708 * MOS and places the dnode of the file in the memory address DNODE. 1709 * 1710 * Return: 1711 * 1 - success 1712 * 0 - failure 1713 */ 1714 int 1715 zfs_open(char *filename) 1716 { 1717 char *stack; 1718 dnode_phys_t *mdn; 1719 1720 file_buf = NULL; 1721 stackbase = ZFS_SCRATCH; 1722 stack = stackbase; 1723 1724 mdn = (dnode_phys_t *)stack; 1725 stack += sizeof (dnode_phys_t); 1726 1727 dnode_mdn = NULL; 1728 dnode_buf = (dnode_phys_t *)stack; 1729 stack += 1<<DNODE_BLOCK_SHIFT; 1730 1731 /* 1732 * menu.lst is placed at the root pool filesystem level, 1733 * do not goto 'current_bootfs'. 1734 */ 1735 if (is_top_dataset_file(filename)) { 1736 if (errnum = get_objset_mdn(MOS, NULL, NULL, mdn, stack)) 1737 return (0); 1738 1739 current_bootfs_obj = 0; 1740 } else { 1741 if (current_bootfs[0] == '\0') { 1742 /* Get the default root filesystem object number */ 1743 if (errnum = get_default_bootfsobj(MOS, 1744 ¤t_bootfs_obj, stack)) 1745 return (0); 1746 1747 if (errnum = get_objset_mdn(MOS, NULL, 1748 ¤t_bootfs_obj, mdn, stack)) 1749 return (0); 1750 } else { 1751 if (errnum = get_objset_mdn(MOS, current_bootfs, 1752 ¤t_bootfs_obj, mdn, stack)) { 1753 grub_memset(current_bootfs, 0, MAXNAMELEN); 1754 return (0); 1755 } 1756 } 1757 } 1758 1759 if (dnode_get_path(mdn, filename, DNODE, stack)) { 1760 errnum = ERR_FILE_NOT_FOUND; 1761 return (0); 1762 } 1763 1764 /* get the file size and set the file position to 0 */ 1765 1766 /* 1767 * For DMU_OT_SA we will need to locate the SIZE attribute 1768 * attribute, which could be either in the bonus buffer 1769 * or the "spill" block. 1770 */ 1771 if (DNODE->dn_bonustype == DMU_OT_SA) { 1772 sa_hdr_phys_t *sahdrp; 1773 int hdrsize; 1774 1775 if (DNODE->dn_bonuslen != 0) { 1776 sahdrp = (sa_hdr_phys_t *)DN_BONUS(DNODE); 1777 } else { 1778 if (DNODE->dn_flags & DNODE_FLAG_SPILL_BLKPTR) { 1779 blkptr_t *bp = &DNODE->dn_spill; 1780 void *buf; 1781 1782 buf = (void *)stack; 1783 stack += BP_GET_LSIZE(bp); 1784 1785 /* reset errnum to rawread() failure */ 1786 errnum = 0; 1787 if (zio_read(bp, buf, stack) != 0) { 1788 return (0); 1789 } 1790 sahdrp = buf; 1791 } else { 1792 errnum = ERR_FSYS_CORRUPT; 1793 return (0); 1794 } 1795 } 1796 hdrsize = SA_HDR_SIZE(sahdrp); 1797 filemax = *(uint64_t *)((char *)sahdrp + hdrsize + 1798 SA_SIZE_OFFSET); 1799 } else { 1800 filemax = ((znode_phys_t *)DN_BONUS(DNODE))->zp_size; 1801 } 1802 filepos = 0; 1803 1804 dnode_buf = NULL; 1805 return (1); 1806 } 1807 1808 /* 1809 * zfs_read reads in the data blocks pointed by the DNODE. 1810 * 1811 * Return: 1812 * len - the length successfully read in to the buffer 1813 * 0 - failure 1814 */ 1815 int 1816 zfs_read(char *buf, int len) 1817 { 1818 char *stack; 1819 int blksz, length, movesize; 1820 1821 if (file_buf == NULL) { 1822 file_buf = stackbase; 1823 stackbase += SPA_MAXBLOCKSIZE; 1824 file_start = file_end = 0; 1825 } 1826 stack = stackbase; 1827 1828 /* 1829 * If offset is in memory, move it into the buffer provided and return. 1830 */ 1831 if (filepos >= file_start && filepos+len <= file_end) { 1832 grub_memmove(buf, file_buf + filepos - file_start, len); 1833 filepos += len; 1834 return (len); 1835 } 1836 1837 blksz = DNODE->dn_datablkszsec << SPA_MINBLOCKSHIFT; 1838 1839 /* 1840 * Entire Dnode is too big to fit into the space available. We 1841 * will need to read it in chunks. This could be optimized to 1842 * read in as large a chunk as there is space available, but for 1843 * now, this only reads in one data block at a time. 1844 */ 1845 length = len; 1846 while (length) { 1847 /* 1848 * Find requested blkid and the offset within that block. 1849 */ 1850 uint64_t blkid = filepos / blksz; 1851 1852 if (errnum = dmu_read(DNODE, blkid, file_buf, stack)) 1853 return (0); 1854 1855 file_start = blkid * blksz; 1856 file_end = file_start + blksz; 1857 1858 movesize = MIN(length, file_end - filepos); 1859 1860 grub_memmove(buf, file_buf + filepos - file_start, 1861 movesize); 1862 buf += movesize; 1863 length -= movesize; 1864 filepos += movesize; 1865 } 1866 1867 return (len); 1868 } 1869 1870 /* 1871 * No-Op 1872 */ 1873 int 1874 zfs_embed(int *start_sector, int needed_sectors) 1875 { 1876 return (1); 1877 } 1878 1879 #endif /* FSYS_ZFS */ 1880