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 * Copyright 2007 Sun Microsystems, Inc. All rights reserved. 21 * Use is subject to license terms. 22 */ 23 #pragma ident "%Z%%M% %I% %E% SMI" 24 25 /* 26 * The zfs plug-in routines for GRUB are: 27 * 28 * zfs_mount() - locates a valid uberblock of the root pool and reads 29 * in its MOS at the memory address MOS. 30 * 31 * zfs_open() - locates a plain file object by following the MOS 32 * and places its dnode at the memory address DNODE. 33 * 34 * zfs_read() - read in the data blocks pointed by the DNODE. 35 * 36 * ZFS_SCRATCH is used as a working area. 37 * 38 * (memory addr) MOS DNODE ZFS_SCRATCH 39 * | | | 40 * +-------V---------V----------V---------------+ 41 * memory | | dnode | dnode | scratch | 42 * | | 512B | 512B | area | 43 * +--------------------------------------------+ 44 */ 45 46 #ifdef FSYS_ZFS 47 48 #include "shared.h" 49 #include "filesys.h" 50 #include "fsys_zfs.h" 51 52 /* cache for a file block of the currently zfs_open()-ed file */ 53 static void *file_buf = NULL; 54 static uint64_t file_start = 0; 55 static uint64_t file_end = 0; 56 57 /* cache for a dnode block */ 58 static dnode_phys_t *dnode_buf = NULL; 59 static dnode_phys_t *dnode_mdn = NULL; 60 static uint64_t dnode_start = 0; 61 static uint64_t dnode_end = 0; 62 63 static char *stackbase; 64 65 decomp_entry_t decomp_table[ZIO_COMPRESS_FUNCTIONS] = 66 { 67 {"noop", 0}, 68 {"on", lzjb_decompress}, /* ZIO_COMPRESS_ON */ 69 {"off", 0}, 70 {"lzjb", lzjb_decompress} /* ZIO_COMPRESS_LZJB */ 71 }; 72 73 /* 74 * Our own version of bcmp(). 75 */ 76 static int 77 zfs_bcmp(const void *s1, const void *s2, size_t n) 78 { 79 const uchar_t *ps1 = s1; 80 const uchar_t *ps2 = s2; 81 82 if (s1 != s2 && n != 0) { 83 do { 84 if (*ps1++ != *ps2++) 85 return (1); 86 } while (--n != 0); 87 } 88 89 return (0); 90 } 91 92 /* 93 * Our own version of log2(). Same thing as highbit()-1. 94 */ 95 static int 96 zfs_log2(uint64_t num) 97 { 98 int i = 0; 99 100 while (num > 1) { 101 i++; 102 num = num >> 1; 103 } 104 105 return (i); 106 } 107 108 /* Checksum Functions */ 109 static void 110 zio_checksum_off(const void *buf, uint64_t size, zio_cksum_t *zcp) 111 { 112 ZIO_SET_CHECKSUM(zcp, 0, 0, 0, 0); 113 } 114 115 /* Checksum Table and Values */ 116 zio_checksum_info_t zio_checksum_table[ZIO_CHECKSUM_FUNCTIONS] = { 117 NULL, NULL, 0, 0, "inherit", 118 NULL, NULL, 0, 0, "on", 119 zio_checksum_off, zio_checksum_off, 0, 0, "off", 120 zio_checksum_SHA256, zio_checksum_SHA256, 1, 1, "label", 121 zio_checksum_SHA256, zio_checksum_SHA256, 1, 1, "gang_header", 122 fletcher_2_native, fletcher_2_byteswap, 0, 1, "zilog", 123 fletcher_2_native, fletcher_2_byteswap, 0, 0, "fletcher2", 124 fletcher_4_native, fletcher_4_byteswap, 1, 0, "fletcher4", 125 zio_checksum_SHA256, zio_checksum_SHA256, 1, 0, "SHA256", 126 }; 127 128 /* 129 * zio_checksum_verify: Provides support for checksum verification. 130 * 131 * Fletcher2, Fletcher4, and SHA256 are supported. 132 * 133 * Return: 134 * -1 = Failure 135 * 0 = Success 136 */ 137 static int 138 zio_checksum_verify(blkptr_t *bp, char *data, int size) 139 { 140 zio_cksum_t zc = bp->blk_cksum; 141 uint32_t checksum = BP_IS_GANG(bp) ? ZIO_CHECKSUM_GANG_HEADER : 142 BP_GET_CHECKSUM(bp); 143 int byteswap = BP_SHOULD_BYTESWAP(bp); 144 zio_block_tail_t *zbt = (zio_block_tail_t *)(data + size) - 1; 145 zio_checksum_info_t *ci = &zio_checksum_table[checksum]; 146 zio_cksum_t actual_cksum, expected_cksum; 147 148 /* byteswap is not supported */ 149 if (byteswap) 150 return (-1); 151 152 if (checksum >= ZIO_CHECKSUM_FUNCTIONS || ci->ci_func[0] == NULL) 153 return (-1); 154 155 if (ci->ci_zbt) { 156 if (checksum == ZIO_CHECKSUM_GANG_HEADER) { 157 /* 158 * 'gang blocks' is not supported. 159 */ 160 return (-1); 161 } 162 163 if (zbt->zbt_magic == BSWAP_64(ZBT_MAGIC)) { 164 /* byte swapping is not supported */ 165 return (-1); 166 } else { 167 expected_cksum = zbt->zbt_cksum; 168 zbt->zbt_cksum = zc; 169 ci->ci_func[0](data, size, &actual_cksum); 170 zbt->zbt_cksum = expected_cksum; 171 } 172 zc = expected_cksum; 173 174 } else { 175 if (BP_IS_GANG(bp)) 176 return (-1); 177 ci->ci_func[byteswap](data, size, &actual_cksum); 178 } 179 180 if ((actual_cksum.zc_word[0] - zc.zc_word[0]) | 181 (actual_cksum.zc_word[1] - zc.zc_word[1]) | 182 (actual_cksum.zc_word[2] - zc.zc_word[2]) | 183 (actual_cksum.zc_word[3] - zc.zc_word[3])) 184 return (-1); 185 186 return (0); 187 } 188 189 /* 190 * vdev_label_offset takes "offset" (the offset within a vdev_label) and 191 * returns its physical disk offset (starting from the beginning of the vdev). 192 * 193 * Input: 194 * psize : Physical size of this vdev 195 * l : Label Number (0-3) 196 * offset : The offset with a vdev_label in which we want the physical 197 * address 198 * Return: 199 * Success : physical disk offset 200 * Failure : errnum = ERR_BAD_ARGUMENT, return value is meaningless 201 */ 202 uint64_t 203 vdev_label_offset(uint64_t psize, int l, uint64_t offset) 204 { 205 /* XXX Need to add back label support! */ 206 if (l >= VDEV_LABELS/2 || offset > sizeof (vdev_label_t)) { 207 errnum = ERR_BAD_ARGUMENT; 208 return (0); 209 } 210 211 return (offset + l * sizeof (vdev_label_t) + (l < VDEV_LABELS / 2 ? 212 0 : psize - VDEV_LABELS * sizeof (vdev_label_t))); 213 214 } 215 216 /* 217 * vdev_uberblock_compare takes two uberblock structures and returns an integer 218 * indicating the more recent of the two. 219 * Return Value = 1 if ub2 is more recent 220 * Return Value = -1 if ub1 is more recent 221 * The most recent uberblock is determined using its transaction number and 222 * timestamp. The uberblock with the highest transaction number is 223 * considered "newer". If the transaction numbers of the two blocks match, the 224 * timestamps are compared to determine the "newer" of the two. 225 */ 226 static int 227 vdev_uberblock_compare(uberblock_t *ub1, uberblock_t *ub2) 228 { 229 if (ub1->ub_txg < ub2->ub_txg) 230 return (-1); 231 if (ub1->ub_txg > ub2->ub_txg) 232 return (1); 233 234 if (ub1->ub_timestamp < ub2->ub_timestamp) 235 return (-1); 236 if (ub1->ub_timestamp > ub2->ub_timestamp) 237 return (1); 238 239 return (0); 240 } 241 242 /* 243 * Three pieces of information are needed to verify an uberblock: the magic 244 * number, the version number, and the checksum. 245 * 246 * Currently Implemented: version number, magic number 247 * Need to Implement: checksum 248 * 249 * Return: 250 * 0 - Success 251 * -1 - Failure 252 */ 253 static int 254 uberblock_verify(uberblock_phys_t *ub, int offset) 255 { 256 257 uberblock_t *uber = &ub->ubp_uberblock; 258 blkptr_t bp; 259 260 BP_ZERO(&bp); 261 BP_SET_CHECKSUM(&bp, ZIO_CHECKSUM_LABEL); 262 BP_SET_BYTEORDER(&bp, ZFS_HOST_BYTEORDER); 263 ZIO_SET_CHECKSUM(&bp.blk_cksum, offset, 0, 0, 0); 264 265 if (zio_checksum_verify(&bp, (char *)ub, UBERBLOCK_SIZE) != 0) 266 return (-1); 267 268 if (uber->ub_magic == UBERBLOCK_MAGIC && 269 uber->ub_version >= SPA_VERSION_1 && 270 uber->ub_version <= SPA_VERSION) 271 return (0); 272 273 return (-1); 274 } 275 276 /* 277 * Find the best uberblock. 278 * Return: 279 * Success - Pointer to the best uberblock. 280 * Failure - NULL 281 */ 282 static uberblock_phys_t * 283 find_bestub(uberblock_phys_t *ub_array, int label) 284 { 285 uberblock_phys_t *ubbest = NULL; 286 int i, offset; 287 288 for (i = 0; i < (VDEV_UBERBLOCK_RING >> VDEV_UBERBLOCK_SHIFT); i++) { 289 offset = vdev_label_offset(0, label, VDEV_UBERBLOCK_OFFSET(i)); 290 if (errnum == ERR_BAD_ARGUMENT) 291 return (NULL); 292 if (uberblock_verify(&ub_array[i], offset) == 0) { 293 if (ubbest == NULL) { 294 ubbest = &ub_array[i]; 295 } else if (vdev_uberblock_compare( 296 &(ub_array[i].ubp_uberblock), 297 &(ubbest->ubp_uberblock)) > 0) { 298 ubbest = &ub_array[i]; 299 } 300 } 301 } 302 303 return (ubbest); 304 } 305 306 /* 307 * Read in a block and put its uncompressed data in buf. 308 * 309 * Return: 310 * 0 - success 311 * errnum - failure 312 */ 313 static int 314 zio_read(blkptr_t *bp, void *buf, char *stack) 315 { 316 uint64_t offset, sector; 317 int psize, lsize; 318 int i, comp, cksum; 319 320 psize = BP_GET_PSIZE(bp); 321 lsize = BP_GET_LSIZE(bp); 322 comp = BP_GET_COMPRESS(bp); 323 cksum = BP_GET_CHECKSUM(bp); 324 325 if ((unsigned int)comp >= ZIO_COMPRESS_FUNCTIONS || 326 comp != ZIO_COMPRESS_OFF && decomp_table[comp].decomp_func == NULL) 327 return (ERR_FSYS_CORRUPT); 328 329 /* pick a good dva from the block pointer */ 330 for (i = 0; i < SPA_DVAS_PER_BP; i++) { 331 332 if (bp->blk_dva[i].dva_word[0] == 0 && 333 bp->blk_dva[i].dva_word[1] == 0) 334 continue; 335 336 /* read in a block */ 337 offset = DVA_GET_OFFSET(&bp->blk_dva[i]); 338 sector = DVA_OFFSET_TO_PHYS_SECTOR(offset); 339 340 if (comp != ZIO_COMPRESS_OFF) { 341 342 if (devread(sector, 0, psize, stack) == 0) 343 continue; 344 if (zio_checksum_verify(bp, stack, psize) != 0) 345 continue; 346 decomp_table[comp].decomp_func(stack, buf, psize, 347 lsize); 348 } else { 349 if (devread(sector, 0, psize, buf) == 0) 350 continue; 351 if (zio_checksum_verify(bp, buf, psize) != 0) 352 continue; 353 } 354 return (0); 355 } 356 357 return (ERR_FSYS_CORRUPT); 358 } 359 360 /* 361 * Get the block from a block id. 362 * push the block onto the stack. 363 * 364 * Return: 365 * 0 - success 366 * errnum - failure 367 */ 368 static int 369 dmu_read(dnode_phys_t *dn, uint64_t blkid, void *buf, char *stack) 370 { 371 int idx, level; 372 blkptr_t *bp_array = dn->dn_blkptr; 373 int epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; 374 blkptr_t *bp, *tmpbuf; 375 376 bp = (blkptr_t *)stack; 377 stack += sizeof (blkptr_t); 378 379 tmpbuf = (blkptr_t *)stack; 380 stack += 1<<dn->dn_indblkshift; 381 382 for (level = dn->dn_nlevels - 1; level >= 0; level--) { 383 idx = (blkid >> (epbs * level)) & ((1<<epbs)-1); 384 *bp = bp_array[idx]; 385 if (level == 0) 386 tmpbuf = buf; 387 if (BP_IS_HOLE(bp)) { 388 grub_memset(buf, 0, 389 dn->dn_datablkszsec << SPA_MINBLOCKSHIFT); 390 break; 391 } else if (errnum = zio_read(bp, tmpbuf, stack)) { 392 return (errnum); 393 } 394 395 bp_array = tmpbuf; 396 } 397 398 return (0); 399 } 400 401 /* 402 * mzap_lookup: Looks up property described by "name" and returns the value 403 * in "value". 404 * 405 * Return: 406 * 0 - success 407 * errnum - failure 408 */ 409 static int 410 mzap_lookup(mzap_phys_t *zapobj, int objsize, char *name, 411 uint64_t *value) 412 { 413 int i, chunks; 414 mzap_ent_phys_t *mzap_ent = zapobj->mz_chunk; 415 416 chunks = objsize/MZAP_ENT_LEN - 1; 417 for (i = 0; i < chunks; i++) { 418 if (grub_strcmp(mzap_ent[i].mze_name, name) == 0) { 419 *value = mzap_ent[i].mze_value; 420 return (0); 421 } 422 } 423 424 return (ERR_FSYS_CORRUPT); 425 } 426 427 static uint64_t 428 zap_hash(uint64_t salt, const char *name) 429 { 430 static uint64_t table[256]; 431 const uint8_t *cp; 432 uint8_t c; 433 uint64_t crc = salt; 434 435 if (table[128] == 0) { 436 uint64_t *ct; 437 int i, j; 438 for (i = 0; i < 256; i++) { 439 for (ct = table + i, *ct = i, j = 8; j > 0; j--) 440 *ct = (*ct >> 1) ^ (-(*ct & 1) & 441 ZFS_CRC64_POLY); 442 } 443 } 444 445 if (crc == 0 || table[128] != ZFS_CRC64_POLY) { 446 errnum = ERR_FSYS_CORRUPT; 447 return (0); 448 } 449 450 for (cp = (const uint8_t *)name; (c = *cp) != '\0'; cp++) 451 crc = (crc >> 8) ^ table[(crc ^ c) & 0xFF]; 452 453 /* 454 * Only use 28 bits, since we need 4 bits in the cookie for the 455 * collision differentiator. We MUST use the high bits, since 456 * those are the onces that we first pay attention to when 457 * chosing the bucket. 458 */ 459 crc &= ~((1ULL << (64 - ZAP_HASHBITS)) - 1); 460 461 return (crc); 462 } 463 464 /* 465 * Only to be used on 8-bit arrays. 466 * array_len is actual len in bytes (not encoded le_value_length). 467 * buf is null-terminated. 468 */ 469 static int 470 zap_leaf_array_equal(zap_leaf_phys_t *l, int blksft, int chunk, 471 int array_len, const char *buf) 472 { 473 int bseen = 0; 474 475 while (bseen < array_len) { 476 struct zap_leaf_array *la = 477 &ZAP_LEAF_CHUNK(l, blksft, chunk).l_array; 478 int toread = MIN(array_len - bseen, ZAP_LEAF_ARRAY_BYTES); 479 480 if (chunk >= ZAP_LEAF_NUMCHUNKS(blksft)) 481 return (0); 482 483 if (zfs_bcmp(la->la_array, buf + bseen, toread) != 0) 484 break; 485 chunk = la->la_next; 486 bseen += toread; 487 } 488 return (bseen == array_len); 489 } 490 491 /* 492 * Given a zap_leaf_phys_t, walk thru the zap leaf chunks to get the 493 * value for the property "name". 494 * 495 * Return: 496 * 0 - success 497 * errnum - failure 498 */ 499 int 500 zap_leaf_lookup(zap_leaf_phys_t *l, int blksft, uint64_t h, 501 const char *name, uint64_t *value) 502 { 503 uint16_t chunk; 504 struct zap_leaf_entry *le; 505 506 /* Verify if this is a valid leaf block */ 507 if (l->l_hdr.lh_block_type != ZBT_LEAF) 508 return (ERR_FSYS_CORRUPT); 509 if (l->l_hdr.lh_magic != ZAP_LEAF_MAGIC) 510 return (ERR_FSYS_CORRUPT); 511 512 for (chunk = l->l_hash[LEAF_HASH(blksft, h)]; 513 chunk != CHAIN_END; chunk = le->le_next) { 514 515 if (chunk >= ZAP_LEAF_NUMCHUNKS(blksft)) 516 return (ERR_FSYS_CORRUPT); 517 518 le = ZAP_LEAF_ENTRY(l, blksft, chunk); 519 520 /* Verify the chunk entry */ 521 if (le->le_type != ZAP_CHUNK_ENTRY) 522 return (ERR_FSYS_CORRUPT); 523 524 if (le->le_hash != h) 525 continue; 526 527 if (zap_leaf_array_equal(l, blksft, le->le_name_chunk, 528 le->le_name_length, name)) { 529 530 struct zap_leaf_array *la; 531 uint8_t *ip; 532 533 if (le->le_int_size != 8 || le->le_value_length != 1) 534 return (ERR_FSYS_CORRUPT); 535 536 /* get the uint64_t property value */ 537 la = &ZAP_LEAF_CHUNK(l, blksft, 538 le->le_value_chunk).l_array; 539 ip = la->la_array; 540 541 *value = (uint64_t)ip[0] << 56 | (uint64_t)ip[1] << 48 | 542 (uint64_t)ip[2] << 40 | (uint64_t)ip[3] << 32 | 543 (uint64_t)ip[4] << 24 | (uint64_t)ip[5] << 16 | 544 (uint64_t)ip[6] << 8 | (uint64_t)ip[7]; 545 546 return (0); 547 } 548 } 549 550 return (ERR_FSYS_CORRUPT); 551 } 552 553 /* 554 * Fat ZAP lookup 555 * 556 * Return: 557 * 0 - success 558 * errnum - failure 559 */ 560 int 561 fzap_lookup(dnode_phys_t *zap_dnode, zap_phys_t *zap, 562 char *name, uint64_t *value, char *stack) 563 { 564 zap_leaf_phys_t *l; 565 uint64_t hash, idx, blkid; 566 int blksft = zfs_log2(zap_dnode->dn_datablkszsec << DNODE_SHIFT); 567 568 /* Verify if this is a fat zap header block */ 569 if (zap->zap_magic != (uint64_t)ZAP_MAGIC) 570 return (ERR_FSYS_CORRUPT); 571 572 hash = zap_hash(zap->zap_salt, name); 573 if (errnum) 574 return (errnum); 575 576 /* get block id from index */ 577 if (zap->zap_ptrtbl.zt_numblks != 0) { 578 /* external pointer tables not supported */ 579 return (ERR_FSYS_CORRUPT); 580 } 581 idx = ZAP_HASH_IDX(hash, zap->zap_ptrtbl.zt_shift); 582 blkid = ((uint64_t *)zap)[idx + (1<<(blksft-3-1))]; 583 584 /* Get the leaf block */ 585 l = (zap_leaf_phys_t *)stack; 586 stack += 1<<blksft; 587 if (errnum = dmu_read(zap_dnode, blkid, l, stack)) 588 return (errnum); 589 590 return (zap_leaf_lookup(l, blksft, hash, name, value)); 591 } 592 593 /* 594 * Read in the data of a zap object and find the value for a matching 595 * property name. 596 * 597 * Return: 598 * 0 - success 599 * errnum - failure 600 */ 601 static int 602 zap_lookup(dnode_phys_t *zap_dnode, char *name, uint64_t *val, char *stack) 603 { 604 uint64_t block_type; 605 int size; 606 void *zapbuf; 607 608 /* Read in the first block of the zap object data. */ 609 zapbuf = stack; 610 size = zap_dnode->dn_datablkszsec << SPA_MINBLOCKSHIFT; 611 stack += size; 612 if (errnum = dmu_read(zap_dnode, 0, zapbuf, stack)) 613 return (errnum); 614 615 block_type = *((uint64_t *)zapbuf); 616 617 if (block_type == ZBT_MICRO) { 618 return (mzap_lookup(zapbuf, size, name, val)); 619 } else if (block_type == ZBT_HEADER) { 620 /* this is a fat zap */ 621 return (fzap_lookup(zap_dnode, zapbuf, name, 622 val, stack)); 623 } 624 625 return (ERR_FSYS_CORRUPT); 626 } 627 628 /* 629 * Get the dnode of an object number from the metadnode of an object set. 630 * 631 * Input 632 * mdn - metadnode to get the object dnode 633 * objnum - object number for the object dnode 634 * buf - data buffer that holds the returning dnode 635 * stack - scratch area 636 * 637 * Return: 638 * 0 - success 639 * errnum - failure 640 */ 641 static int 642 dnode_get(dnode_phys_t *mdn, uint64_t objnum, uint8_t type, dnode_phys_t *buf, 643 char *stack) 644 { 645 uint64_t blkid, blksz; /* the block id this object dnode is in */ 646 int epbs; /* shift of number of dnodes in a block */ 647 int idx; /* index within a block */ 648 dnode_phys_t *dnbuf; 649 650 blksz = mdn->dn_datablkszsec << SPA_MINBLOCKSHIFT; 651 epbs = zfs_log2(blksz) - DNODE_SHIFT; 652 blkid = objnum >> epbs; 653 idx = objnum & ((1<<epbs)-1); 654 655 if (dnode_buf != NULL && dnode_mdn == mdn && 656 objnum >= dnode_start && objnum < dnode_end) { 657 grub_memmove(buf, &dnode_buf[idx], DNODE_SIZE); 658 VERIFY_DN_TYPE(buf, type); 659 return (0); 660 } 661 662 if (dnode_buf && blksz == 1<<DNODE_BLOCK_SHIFT) { 663 dnbuf = dnode_buf; 664 dnode_mdn = mdn; 665 dnode_start = blkid << epbs; 666 dnode_end = (blkid + 1) << epbs; 667 } else { 668 dnbuf = (dnode_phys_t *)stack; 669 stack += blksz; 670 } 671 672 if (errnum = dmu_read(mdn, blkid, (char *)dnbuf, stack)) 673 return (errnum); 674 675 grub_memmove(buf, &dnbuf[idx], DNODE_SIZE); 676 VERIFY_DN_TYPE(buf, type); 677 678 return (0); 679 } 680 681 /* 682 * Check if this is the "menu.lst" file. 683 * str starts with '/'. 684 */ 685 static int 686 is_menu_lst(char *str) 687 { 688 char *tptr; 689 690 if ((tptr = grub_strstr(str, "menu.lst")) && 691 (tptr[8] == '\0' || tptr[8] == ' ') && 692 *(tptr-1) == '/') 693 return (1); 694 695 return (0); 696 } 697 698 /* 699 * Get the file dnode for a given file name where mdn is the meta dnode 700 * for this ZFS object set. When found, place the file dnode in dn. 701 * The 'path' argument will be mangled. 702 * 703 * Return: 704 * 0 - success 705 * errnum - failure 706 */ 707 static int 708 dnode_get_path(dnode_phys_t *mdn, char *path, dnode_phys_t *dn, 709 char *stack) 710 { 711 uint64_t objnum, version; 712 char *cname, ch; 713 714 if (errnum = dnode_get(mdn, MASTER_NODE_OBJ, DMU_OT_MASTER_NODE, 715 dn, stack)) 716 return (errnum); 717 718 if (errnum = zap_lookup(dn, ZPL_VERSION_STR, &version, stack)) 719 return (errnum); 720 if (version > ZPL_VERSION) 721 return (-1); 722 723 if (errnum = zap_lookup(dn, ZFS_ROOT_OBJ, &objnum, stack)) 724 return (errnum); 725 726 if (errnum = dnode_get(mdn, objnum, DMU_OT_DIRECTORY_CONTENTS, 727 dn, stack)) 728 return (errnum); 729 730 /* skip leading slashes */ 731 while (*path == '/') 732 path++; 733 734 while (*path && !isspace(*path)) { 735 736 /* get the next component name */ 737 cname = path; 738 while (*path && !isspace(*path) && *path != '/') 739 path++; 740 ch = *path; 741 *path = 0; /* ensure null termination */ 742 743 if (errnum = zap_lookup(dn, cname, &objnum, stack)) 744 return (errnum); 745 746 objnum = ZFS_DIRENT_OBJ(objnum); 747 if (errnum = dnode_get(mdn, objnum, 0, dn, stack)) 748 return (errnum); 749 750 *path = ch; 751 while (*path == '/') 752 path++; 753 } 754 755 /* We found the dnode for this file. Verify if it is a plain file. */ 756 VERIFY_DN_TYPE(dn, DMU_OT_PLAIN_FILE_CONTENTS); 757 758 return (0); 759 } 760 761 /* 762 * Get the default 'bootfs' property value from the rootpool. 763 * 764 * Return: 765 * 0 - success 766 * errnum -failure 767 */ 768 static int 769 get_default_bootfsobj(dnode_phys_t *mosmdn, uint64_t *obj, char *stack) 770 { 771 uint64_t objnum = 0; 772 dnode_phys_t *dn = (dnode_phys_t *)stack; 773 stack += DNODE_SIZE; 774 775 if (errnum = dnode_get(mosmdn, DMU_POOL_DIRECTORY_OBJECT, 776 DMU_OT_OBJECT_DIRECTORY, dn, stack)) 777 return (errnum); 778 779 /* 780 * find the object number for 'pool_props', and get the dnode 781 * of the 'pool_props'. 782 */ 783 if (zap_lookup(dn, DMU_POOL_PROPS, &objnum, stack)) 784 return (ERR_FILESYSTEM_NOT_FOUND); 785 786 if (errnum = dnode_get(mosmdn, objnum, DMU_OT_POOL_PROPS, dn, stack)) 787 return (errnum); 788 789 if (zap_lookup(dn, ZPOOL_PROP_BOOTFS, &objnum, stack)) 790 return (ERR_FILESYSTEM_NOT_FOUND); 791 792 if (!objnum) 793 return (ERR_FILESYSTEM_NOT_FOUND); 794 795 *obj = objnum; 796 return (0); 797 } 798 799 /* 800 * Given a MOS metadnode, get the metadnode of a given filesystem name (fsname), 801 * e.g. pool/rootfs, or a given object number (obj), e.g. the object number 802 * of pool/rootfs. 803 * 804 * If no fsname and no obj are given, return the DSL_DIR metadnode. 805 * If fsname is given, return its metadnode and its matching object number. 806 * If only obj is given, return the metadnode for this object number. 807 * 808 * Return: 809 * 0 - success 810 * errnum - failure 811 */ 812 static int 813 get_objset_mdn(dnode_phys_t *mosmdn, char *fsname, uint64_t *obj, 814 dnode_phys_t *mdn, char *stack) 815 { 816 uint64_t objnum, headobj; 817 char *cname, ch; 818 blkptr_t *bp; 819 objset_phys_t *osp; 820 821 if (fsname == NULL && obj) { 822 headobj = *obj; 823 goto skip; 824 } 825 826 if (errnum = dnode_get(mosmdn, DMU_POOL_DIRECTORY_OBJECT, 827 DMU_OT_OBJECT_DIRECTORY, mdn, stack)) 828 return (errnum); 829 830 if (errnum = zap_lookup(mdn, DMU_POOL_ROOT_DATASET, &objnum, 831 stack)) 832 return (errnum); 833 834 if (errnum = dnode_get(mosmdn, objnum, DMU_OT_DSL_DIR, mdn, stack)) 835 return (errnum); 836 837 if (fsname == NULL) { 838 headobj = 839 ((dsl_dir_phys_t *)DN_BONUS(mdn))->dd_head_dataset_obj; 840 goto skip; 841 } 842 843 /* take out the pool name */ 844 while (*fsname && !isspace(*fsname) && *fsname != '/') 845 fsname++; 846 847 while (*fsname && !isspace(*fsname)) { 848 uint64_t childobj; 849 850 while (*fsname == '/') 851 fsname++; 852 853 cname = fsname; 854 while (*fsname && !isspace(*fsname) && *fsname != '/') 855 fsname++; 856 ch = *fsname; 857 *fsname = 0; 858 859 childobj = 860 ((dsl_dir_phys_t *)DN_BONUS(mdn))->dd_child_dir_zapobj; 861 if (errnum = dnode_get(mosmdn, childobj, 862 DMU_OT_DSL_DIR_CHILD_MAP, mdn, stack)) 863 return (errnum); 864 865 if (zap_lookup(mdn, cname, &objnum, stack)) 866 return (ERR_FILESYSTEM_NOT_FOUND); 867 868 if (errnum = dnode_get(mosmdn, objnum, DMU_OT_DSL_DIR, 869 mdn, stack)) 870 return (errnum); 871 872 *fsname = ch; 873 } 874 headobj = ((dsl_dir_phys_t *)DN_BONUS(mdn))->dd_head_dataset_obj; 875 if (obj) 876 *obj = headobj; 877 878 skip: 879 if (errnum = dnode_get(mosmdn, headobj, DMU_OT_DSL_DATASET, mdn, stack)) 880 return (errnum); 881 882 /* TODO: Add snapshot support here - for fsname=snapshot-name */ 883 884 bp = &((dsl_dataset_phys_t *)DN_BONUS(mdn))->ds_bp; 885 osp = (objset_phys_t *)stack; 886 stack += sizeof (objset_phys_t); 887 if (errnum = zio_read(bp, osp, stack)) 888 return (errnum); 889 890 grub_memmove((char *)mdn, (char *)&osp->os_meta_dnode, DNODE_SIZE); 891 892 return (0); 893 } 894 895 /* 896 * Parse the packed nvlist and search for the string value of a given name. 897 * 898 * An XDR packed nvlist is encoded as (from nvs_xdr_create) : 899 * 900 * encoding method/host endian (4 bytes) 901 * nvl_version (4 bytes) 902 * nvl_nvflag (4 bytes) 903 * encoded nvpairs: 904 * encoded size of the nvpair (4 bytes) 905 * decoded size of the nvpair (4 bytes) 906 * name string size (4 bytes) 907 * name string data (sizeof(NV_ALIGN4(string)) 908 * data type (4 bytes) 909 * # of elements in the nvpair (4 bytes) 910 * data 911 * 2 zero's for the last nvpair 912 * (end of the entire list) (8 bytes) 913 * 914 * Return: 915 * 0 - success 916 * 1 - failure 917 */ 918 int 919 nvlist_lookup_value(char *nvlist, char *name, void *val, int valtype) 920 { 921 int name_len, type, nelm, slen, encode_size; 922 char *nvpair, *nvp_name, *strval = val; 923 uint64_t *intval = val; 924 925 /* Verify if the 1st and 2nd byte in the nvlist are valid. */ 926 if (nvlist[0] != NV_ENCODE_XDR || nvlist[1] != HOST_ENDIAN) 927 return (1); 928 929 /* skip the header, nvl_version, and nvl_nvflag */ 930 nvlist = nvlist + 4 * 3; 931 932 /* 933 * Loop thru the nvpair list 934 * The XDR representation of an integer is in big-endian byte order. 935 */ 936 while (encode_size = BSWAP_32(*(uint32_t *)nvlist)) { 937 938 nvpair = nvlist + 4 * 2; /* skip the encode/decode size */ 939 940 name_len = BSWAP_32(*(uint32_t *)nvpair); 941 nvpair += 4; 942 943 nvp_name = nvpair; 944 nvpair = nvpair + ((name_len + 3) & ~3); /* align */ 945 946 type = BSWAP_32(*(uint32_t *)nvpair); 947 nvpair += 4; 948 949 if ((grub_strncmp(nvp_name, name, name_len) == 0) && 950 type == valtype) { 951 952 if ((nelm = BSWAP_32(*(uint32_t *)nvpair)) != 1) 953 return (1); 954 nvpair += 4; 955 956 switch (valtype) { 957 case DATA_TYPE_STRING: 958 slen = BSWAP_32(*(uint32_t *)nvpair); 959 nvpair += 4; 960 grub_memmove(strval, nvpair, slen); 961 strval[slen] = '\0'; 962 return (0); 963 964 case DATA_TYPE_UINT64: 965 *intval = BSWAP_64(*(uint64_t *)nvpair); 966 return (0); 967 } 968 } 969 970 nvlist += encode_size; /* goto the next nvpair */ 971 } 972 973 return (1); 974 } 975 976 /* 977 * Get the pool name of the root pool from the vdev nvpair list of the label. 978 * 979 * Return: 980 * 0 - success 981 * errnum - failure 982 */ 983 int 984 get_pool_name_value(int label, char *name, void *value, int valtype, 985 char *stack) 986 { 987 vdev_phys_t *vdev; 988 uint64_t sector; 989 990 sector = (label * sizeof (vdev_label_t) + VDEV_SKIP_SIZE + 991 VDEV_BOOT_HEADER_SIZE) >> SPA_MINBLOCKSHIFT; 992 993 /* Read in the vdev name-value pair list (112K). */ 994 if (devread(sector, 0, VDEV_PHYS_SIZE, stack) == 0) 995 return (ERR_READ); 996 997 vdev = (vdev_phys_t *)stack; 998 999 if (nvlist_lookup_value(vdev->vp_nvlist, name, value, valtype)) 1000 return (ERR_FSYS_CORRUPT); 1001 else 1002 return (0); 1003 } 1004 1005 /* 1006 * zfs_mount() locates a valid uberblock of the root pool and read in its MOS 1007 * to the memory address MOS. 1008 * 1009 * Return: 1010 * 1 - success 1011 * 0 - failure 1012 */ 1013 int 1014 zfs_mount(void) 1015 { 1016 char *stack; 1017 int label = 0; 1018 uberblock_phys_t *ub_array, *ubbest = NULL; 1019 objset_phys_t *osp; 1020 1021 /* if zfs is already mounted, don't do it again */ 1022 if (is_zfs_mount == 1) 1023 return (1); 1024 1025 stackbase = ZFS_SCRATCH; 1026 stack = stackbase; 1027 ub_array = (uberblock_phys_t *)stack; 1028 stack += VDEV_UBERBLOCK_RING; 1029 1030 osp = (objset_phys_t *)stack; 1031 stack += sizeof (objset_phys_t); 1032 1033 /* XXX add back labels support? */ 1034 for (label = 0; ubbest == NULL && label < (VDEV_LABELS/2); label++) { 1035 uint64_t sector = (label * sizeof (vdev_label_t) + 1036 VDEV_SKIP_SIZE + VDEV_BOOT_HEADER_SIZE + 1037 VDEV_PHYS_SIZE) >> SPA_MINBLOCKSHIFT; 1038 1039 /* Read in the uberblock ring (128K). */ 1040 if (devread(sector, 0, VDEV_UBERBLOCK_RING, 1041 (char *)ub_array) == 0) 1042 continue; 1043 1044 if ((ubbest = find_bestub(ub_array, label)) != NULL && 1045 zio_read(&ubbest->ubp_uberblock.ub_rootbp, osp, stack) 1046 == 0) { 1047 uint64_t pool_state; 1048 1049 VERIFY_OS_TYPE(osp, DMU_OST_META); 1050 1051 /* Got the MOS. Save it at the memory addr MOS. */ 1052 grub_memmove(MOS, &osp->os_meta_dnode, DNODE_SIZE); 1053 1054 if (get_pool_name_value(label, ZPOOL_CONFIG_POOL_STATE, 1055 &pool_state, DATA_TYPE_UINT64, stack)) 1056 return (0); 1057 1058 if (pool_state == POOL_STATE_DESTROYED) 1059 return (0); 1060 1061 if (get_pool_name_value(label, ZPOOL_CONFIG_POOL_NAME, 1062 current_rootpool, DATA_TYPE_STRING, stack)) 1063 return (0); 1064 1065 is_zfs_mount = 1; 1066 return (1); 1067 } 1068 } 1069 1070 return (0); 1071 } 1072 1073 /* 1074 * zfs_open() locates a file in the rootpool by following the 1075 * MOS and places the dnode of the file in the memory address DNODE. 1076 * 1077 * Return: 1078 * 1 - success 1079 * 0 - failure 1080 */ 1081 int 1082 zfs_open(char *filename) 1083 { 1084 char *stack; 1085 dnode_phys_t *mdn; 1086 1087 file_buf = NULL; 1088 stackbase = ZFS_SCRATCH; 1089 stack = stackbase; 1090 1091 mdn = (dnode_phys_t *)stack; 1092 stack += sizeof (dnode_phys_t); 1093 1094 dnode_mdn = NULL; 1095 dnode_buf = (dnode_phys_t *)stack; 1096 stack += 1<<DNODE_BLOCK_SHIFT; 1097 1098 /* 1099 * menu.lst is placed at the root pool filesystem level, 1100 * do not goto 'current_bootfs'. 1101 */ 1102 if (is_menu_lst(filename)) { 1103 if (errnum = get_objset_mdn(MOS, NULL, NULL, mdn, stack)) 1104 return (0); 1105 1106 current_bootfs_obj = 0; 1107 } else { 1108 if (current_bootfs[0] == '\0') { 1109 /* Get the default root filesystem object number */ 1110 if (errnum = get_default_bootfsobj(MOS, 1111 ¤t_bootfs_obj, stack)) 1112 return (0); 1113 1114 if (errnum = get_objset_mdn(MOS, NULL, 1115 ¤t_bootfs_obj, mdn, stack)) 1116 return (0); 1117 } else { 1118 if (errnum = get_objset_mdn(MOS, 1119 current_bootfs, ¤t_bootfs_obj, mdn, stack)) 1120 return (0); 1121 } 1122 } 1123 1124 if (dnode_get_path(mdn, filename, DNODE, stack)) { 1125 errnum = ERR_FILE_NOT_FOUND; 1126 return (0); 1127 } 1128 1129 /* get the file size and set the file position to 0 */ 1130 filemax = ((znode_phys_t *)DN_BONUS(DNODE))->zp_size; 1131 filepos = 0; 1132 1133 dnode_buf = NULL; 1134 return (1); 1135 } 1136 1137 /* 1138 * zfs_read reads in the data blocks pointed by the DNODE. 1139 * 1140 * Return: 1141 * len - the length successfully read in to the buffer 1142 * 0 - failure 1143 */ 1144 int 1145 zfs_read(char *buf, int len) 1146 { 1147 char *stack; 1148 char *tmpbuf; 1149 int blksz, length, movesize; 1150 1151 if (file_buf == NULL) { 1152 file_buf = stackbase; 1153 stackbase += SPA_MAXBLOCKSIZE; 1154 file_start = file_end = 0; 1155 } 1156 stack = stackbase; 1157 1158 /* 1159 * If offset is in memory, move it into the buffer provided and return. 1160 */ 1161 if (filepos >= file_start && filepos+len <= file_end) { 1162 grub_memmove(buf, file_buf + filepos - file_start, len); 1163 filepos += len; 1164 return (len); 1165 } 1166 1167 blksz = DNODE->dn_datablkszsec << SPA_MINBLOCKSHIFT; 1168 1169 /* 1170 * Entire Dnode is too big to fit into the space available. We 1171 * will need to read it in chunks. This could be optimized to 1172 * read in as large a chunk as there is space available, but for 1173 * now, this only reads in one data block at a time. 1174 */ 1175 length = len; 1176 while (length) { 1177 /* 1178 * Find requested blkid and the offset within that block. 1179 */ 1180 uint64_t blkid = filepos / blksz; 1181 1182 if (errnum = dmu_read(DNODE, blkid, file_buf, stack)) 1183 return (0); 1184 1185 file_start = blkid * blksz; 1186 file_end = file_start + blksz; 1187 1188 movesize = MIN(length, file_end - filepos); 1189 1190 grub_memmove(buf, file_buf + filepos - file_start, 1191 movesize); 1192 buf += movesize; 1193 length -= movesize; 1194 filepos += movesize; 1195 } 1196 1197 return (len); 1198 } 1199 1200 /* 1201 * No-Op 1202 */ 1203 int 1204 zfs_embed(int *start_sector, int needed_sectors) 1205 { 1206 return (1); 1207 } 1208 1209 #endif /* FSYS_ZFS */ 1210