/* * GRUB -- GRand Unified Bootloader * Copyright (C) 1999,2000,2001,2002,2003,2004 Free Software Foundation, Inc. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ /* * Copyright 2010 Sun Microsystems, Inc. All rights reserved. * Use is subject to license terms. */ /* * Copyright (c) 2013 by Delphix. All rights reserved. * Copyright (c) 2013 by Saso Kiselkov. All rights reserved. */ /* * The zfs plug-in routines for GRUB are: * * zfs_mount() - locates a valid uberblock of the root pool and reads * in its MOS at the memory address MOS. * * zfs_open() - locates a plain file object by following the MOS * and places its dnode at the memory address DNODE. * * zfs_read() - read in the data blocks pointed by the DNODE. * * ZFS_SCRATCH is used as a working area. * * (memory addr) MOS DNODE ZFS_SCRATCH * | | | * +-------V---------V----------V---------------+ * memory | | dnode | dnode | scratch | * | | 512B | 512B | area | * +--------------------------------------------+ */ #ifdef FSYS_ZFS #include "shared.h" #include "filesys.h" #include "fsys_zfs.h" /* cache for a file block of the currently zfs_open()-ed file */ static void *file_buf = NULL; static uint64_t file_start = 0; static uint64_t file_end = 0; /* cache for a dnode block */ static dnode_phys_t *dnode_buf = NULL; static dnode_phys_t *dnode_mdn = NULL; static uint64_t dnode_start = 0; static uint64_t dnode_end = 0; static uint64_t pool_guid = 0; static uberblock_t current_uberblock; static char *stackbase; decomp_entry_t decomp_table[ZIO_COMPRESS_FUNCTIONS] = { {"inherit", 0}, /* ZIO_COMPRESS_INHERIT */ {"on", lzjb_decompress}, /* ZIO_COMPRESS_ON */ {"off", 0}, /* ZIO_COMPRESS_OFF */ {"lzjb", lzjb_decompress}, /* ZIO_COMPRESS_LZJB */ {"empty", 0}, /* ZIO_COMPRESS_EMPTY */ {"gzip-1", 0}, /* ZIO_COMPRESS_GZIP_1 */ {"gzip-2", 0}, /* ZIO_COMPRESS_GZIP_2 */ {"gzip-3", 0}, /* ZIO_COMPRESS_GZIP_3 */ {"gzip-4", 0}, /* ZIO_COMPRESS_GZIP_4 */ {"gzip-5", 0}, /* ZIO_COMPRESS_GZIP_5 */ {"gzip-6", 0}, /* ZIO_COMPRESS_GZIP_6 */ {"gzip-7", 0}, /* ZIO_COMPRESS_GZIP_7 */ {"gzip-8", 0}, /* ZIO_COMPRESS_GZIP_8 */ {"gzip-9", 0}, /* ZIO_COMPRESS_GZIP_9 */ {"zle", 0}, /* ZIO_COMPRESS_ZLE */ {"lz4", lz4_decompress} /* ZIO_COMPRESS_LZ4 */ }; static int zio_read_data(blkptr_t *bp, void *buf, char *stack); /* * Our own version of bcmp(). */ static int zfs_bcmp(const void *s1, const void *s2, size_t n) { const uchar_t *ps1 = s1; const uchar_t *ps2 = s2; if (s1 != s2 && n != 0) { do { if (*ps1++ != *ps2++) return (1); } while (--n != 0); } return (0); } /* * Our own version of log2(). Same thing as highbit()-1. */ static int zfs_log2(uint64_t num) { int i = 0; while (num > 1) { i++; num = num >> 1; } return (i); } /* Checksum Functions */ static void zio_checksum_off(const void *buf, uint64_t size, zio_cksum_t *zcp) { ZIO_SET_CHECKSUM(zcp, 0, 0, 0, 0); } /* Checksum Table and Values */ zio_checksum_info_t zio_checksum_table[ZIO_CHECKSUM_FUNCTIONS] = { {{NULL, NULL}, 0, 0, "inherit"}, {{NULL, NULL}, 0, 0, "on"}, {{zio_checksum_off, zio_checksum_off}, 0, 0, "off"}, {{zio_checksum_SHA256, zio_checksum_SHA256}, 1, 1, "label"}, {{zio_checksum_SHA256, zio_checksum_SHA256}, 1, 1, "gang_header"}, {{NULL, NULL}, 0, 0, "zilog"}, {{fletcher_2_native, fletcher_2_byteswap}, 0, 0, "fletcher2"}, {{fletcher_4_native, fletcher_4_byteswap}, 1, 0, "fletcher4"}, {{zio_checksum_SHA256, zio_checksum_SHA256}, 1, 0, "SHA256"}, {{NULL, NULL}, 0, 0, "zilog2"}, }; /* * zio_checksum_verify: Provides support for checksum verification. * * Fletcher2, Fletcher4, and SHA256 are supported. * * Return: * -1 = Failure * 0 = Success */ static int zio_checksum_verify(blkptr_t *bp, char *data, int size) { zio_cksum_t zc = bp->blk_cksum; uint32_t checksum = BP_GET_CHECKSUM(bp); int byteswap = BP_SHOULD_BYTESWAP(bp); zio_eck_t *zec = (zio_eck_t *)(data + size) - 1; zio_checksum_info_t *ci = &zio_checksum_table[checksum]; zio_cksum_t actual_cksum, expected_cksum; if (byteswap) { grub_printf("byteswap not supported\n"); return (-1); } if (checksum >= ZIO_CHECKSUM_FUNCTIONS || ci->ci_func[0] == NULL) { grub_printf("checksum algorithm %u not supported\n", checksum); return (-1); } if (ci->ci_eck) { expected_cksum = zec->zec_cksum; zec->zec_cksum = zc; ci->ci_func[0](data, size, &actual_cksum); zec->zec_cksum = expected_cksum; zc = expected_cksum; } else { ci->ci_func[byteswap](data, size, &actual_cksum); } if ((actual_cksum.zc_word[0] - zc.zc_word[0]) | (actual_cksum.zc_word[1] - zc.zc_word[1]) | (actual_cksum.zc_word[2] - zc.zc_word[2]) | (actual_cksum.zc_word[3] - zc.zc_word[3])) return (-1); return (0); } /* * vdev_label_start returns the physical disk offset (in bytes) of * label "l". */ static uint64_t vdev_label_start(uint64_t psize, int l) { return (l * sizeof (vdev_label_t) + (l < VDEV_LABELS / 2 ? 0 : psize - VDEV_LABELS * sizeof (vdev_label_t))); } /* * vdev_uberblock_compare takes two uberblock structures and returns an integer * indicating the more recent of the two. * Return Value = 1 if ub2 is more recent * Return Value = -1 if ub1 is more recent * The most recent uberblock is determined using its transaction number and * timestamp. The uberblock with the highest transaction number is * considered "newer". If the transaction numbers of the two blocks match, the * timestamps are compared to determine the "newer" of the two. */ static int vdev_uberblock_compare(uberblock_t *ub1, uberblock_t *ub2) { if (ub1->ub_txg < ub2->ub_txg) return (-1); if (ub1->ub_txg > ub2->ub_txg) return (1); if (ub1->ub_timestamp < ub2->ub_timestamp) return (-1); if (ub1->ub_timestamp > ub2->ub_timestamp) return (1); return (0); } /* * Three pieces of information are needed to verify an uberblock: the magic * number, the version number, and the checksum. * * Return: * 0 - Success * -1 - Failure */ static int uberblock_verify(uberblock_t *uber, uint64_t ub_size, uint64_t offset) { blkptr_t bp; BP_ZERO(&bp); BP_SET_CHECKSUM(&bp, ZIO_CHECKSUM_LABEL); BP_SET_BYTEORDER(&bp, ZFS_HOST_BYTEORDER); ZIO_SET_CHECKSUM(&bp.blk_cksum, offset, 0, 0, 0); if (zio_checksum_verify(&bp, (char *)uber, ub_size) != 0) return (-1); if (uber->ub_magic == UBERBLOCK_MAGIC && SPA_VERSION_IS_SUPPORTED(uber->ub_version)) return (0); return (-1); } /* * Find the best uberblock. * Return: * Success - Pointer to the best uberblock. * Failure - NULL */ static uberblock_t * find_bestub(char *ub_array, uint64_t ashift, uint64_t sector) { uberblock_t *ubbest = NULL; uberblock_t *ubnext; uint64_t offset, ub_size; int i; ub_size = VDEV_UBERBLOCK_SIZE(ashift); for (i = 0; i < VDEV_UBERBLOCK_COUNT(ashift); i++) { ubnext = (uberblock_t *)ub_array; ub_array += ub_size; offset = (sector << SPA_MINBLOCKSHIFT) + VDEV_UBERBLOCK_OFFSET(ashift, i); if (uberblock_verify(ubnext, ub_size, offset) != 0) continue; if (ubbest == NULL || vdev_uberblock_compare(ubnext, ubbest) > 0) ubbest = ubnext; } return (ubbest); } /* * Read a block of data based on the gang block address dva, * and put its data in buf. * * Return: * 0 - success * 1 - failure */ static int zio_read_gang(blkptr_t *bp, dva_t *dva, void *buf, char *stack) { zio_gbh_phys_t *zio_gb; uint64_t offset, sector; blkptr_t tmpbp; int i; zio_gb = (zio_gbh_phys_t *)stack; stack += SPA_GANGBLOCKSIZE; offset = DVA_GET_OFFSET(dva); sector = DVA_OFFSET_TO_PHYS_SECTOR(offset); /* read in the gang block header */ if (devread(sector, 0, SPA_GANGBLOCKSIZE, (char *)zio_gb) == 0) { grub_printf("failed to read in a gang block header\n"); return (1); } /* self checksuming the gang block header */ BP_ZERO(&tmpbp); BP_SET_CHECKSUM(&tmpbp, ZIO_CHECKSUM_GANG_HEADER); BP_SET_BYTEORDER(&tmpbp, ZFS_HOST_BYTEORDER); ZIO_SET_CHECKSUM(&tmpbp.blk_cksum, DVA_GET_VDEV(dva), DVA_GET_OFFSET(dva), bp->blk_birth, 0); if (zio_checksum_verify(&tmpbp, (char *)zio_gb, SPA_GANGBLOCKSIZE)) { grub_printf("failed to checksum a gang block header\n"); return (1); } for (i = 0; i < SPA_GBH_NBLKPTRS; i++) { if (BP_IS_HOLE(&zio_gb->zg_blkptr[i])) continue; if (zio_read_data(&zio_gb->zg_blkptr[i], buf, stack)) return (1); buf += BP_GET_PSIZE(&zio_gb->zg_blkptr[i]); } return (0); } /* * Read in a block of raw data to buf. * * Return: * 0 - success * 1 - failure */ static int zio_read_data(blkptr_t *bp, void *buf, char *stack) { int i, psize; psize = BP_GET_PSIZE(bp); /* pick a good dva from the block pointer */ for (i = 0; i < SPA_DVAS_PER_BP; i++) { uint64_t offset, sector; if (bp->blk_dva[i].dva_word[0] == 0 && bp->blk_dva[i].dva_word[1] == 0) continue; if (DVA_GET_GANG(&bp->blk_dva[i])) { if (zio_read_gang(bp, &bp->blk_dva[i], buf, stack) == 0) return (0); } else { /* read in a data block */ offset = DVA_GET_OFFSET(&bp->blk_dva[i]); sector = DVA_OFFSET_TO_PHYS_SECTOR(offset); if (devread(sector, 0, psize, buf) != 0) return (0); } } return (1); } /* * buf must be at least BPE_GET_PSIZE(bp) bytes long (which will never be * more than BPE_PAYLOAD_SIZE bytes). */ static void decode_embedded_bp_compressed(const blkptr_t *bp, void *buf) { int psize, i; uint8_t *buf8 = buf; uint64_t w = 0; const uint64_t *bp64 = (const uint64_t *)bp; psize = BPE_GET_PSIZE(bp); /* * Decode the words of the block pointer into the byte array. * Low bits of first word are the first byte (little endian). */ for (i = 0; i < psize; i++) { if (i % sizeof (w) == 0) { /* beginning of a word */ w = *bp64; bp64++; if (!BPE_IS_PAYLOADWORD(bp, bp64)) bp64++; } buf8[i] = BF64_GET(w, (i % sizeof (w)) * NBBY, NBBY); } } /* * Fill in the buffer with the (decompressed) payload of the embedded * blkptr_t. Takes into account compression and byteorder (the payload is * treated as a stream of bytes). * Return 0 on success, or ENOSPC if it won't fit in the buffer. */ static int decode_embedded_bp(const blkptr_t *bp, void *buf) { int comp; int lsize, psize; uint8_t *dst = buf; uint64_t w = 0; lsize = BPE_GET_LSIZE(bp); psize = BPE_GET_PSIZE(bp); comp = BP_GET_COMPRESS(bp); if (comp != ZIO_COMPRESS_OFF) { uint8_t dstbuf[BPE_PAYLOAD_SIZE]; if ((unsigned int)comp >= ZIO_COMPRESS_FUNCTIONS || decomp_table[comp].decomp_func == NULL) { grub_printf("compression algorithm not supported\n"); return (ERR_FSYS_CORRUPT); } decode_embedded_bp_compressed(bp, dstbuf); decomp_table[comp].decomp_func(dstbuf, buf, psize, lsize); } else { decode_embedded_bp_compressed(bp, buf); } return (0); } /* * Read in a block of data, verify its checksum, decompress if needed, * and put the uncompressed data in buf. * * Return: * 0 - success * errnum - failure */ static int zio_read(blkptr_t *bp, void *buf, char *stack) { int lsize, psize, comp; char *retbuf; if (BP_IS_EMBEDDED(bp)) { if (BPE_GET_ETYPE(bp) != BP_EMBEDDED_TYPE_DATA) { grub_printf("unsupported embedded BP (type=%u)\n", (int)BPE_GET_ETYPE(bp)); return (ERR_FSYS_CORRUPT); } return (decode_embedded_bp(bp, buf)); } comp = BP_GET_COMPRESS(bp); lsize = BP_GET_LSIZE(bp); psize = BP_GET_PSIZE(bp); if ((unsigned int)comp >= ZIO_COMPRESS_FUNCTIONS || (comp != ZIO_COMPRESS_OFF && decomp_table[comp].decomp_func == NULL)) { grub_printf("compression algorithm not supported\n"); return (ERR_FSYS_CORRUPT); } if ((char *)buf < stack && ((char *)buf) + lsize > stack) { grub_printf("not enough memory to fit %u bytes on stack\n", lsize); return (ERR_WONT_FIT); } retbuf = buf; if (comp != ZIO_COMPRESS_OFF) { buf = stack; stack += psize; } if (zio_read_data(bp, buf, stack) != 0) { grub_printf("zio_read_data failed\n"); return (ERR_FSYS_CORRUPT); } if (zio_checksum_verify(bp, buf, psize) != 0) { grub_printf("checksum verification failed\n"); return (ERR_FSYS_CORRUPT); } if (comp != ZIO_COMPRESS_OFF) { if (decomp_table[comp].decomp_func(buf, retbuf, psize, lsize) != 0) { grub_printf("zio_read decompression failed\n"); return (ERR_FSYS_CORRUPT); } } return (0); } /* * Get the block from a block id. * push the block onto the stack. * * Return: * 0 - success * errnum - failure */ static int dmu_read(dnode_phys_t *dn, uint64_t blkid, void *buf, char *stack) { int idx, level; blkptr_t *bp_array = dn->dn_blkptr; int epbs = dn->dn_indblkshift - SPA_BLKPTRSHIFT; blkptr_t *bp, *tmpbuf; bp = (blkptr_t *)stack; stack += sizeof (blkptr_t); tmpbuf = (blkptr_t *)stack; stack += 1<dn_indblkshift; for (level = dn->dn_nlevels - 1; level >= 0; level--) { idx = (blkid >> (epbs * level)) & ((1<dn_datablkszsec << SPA_MINBLOCKSHIFT); break; } else if (errnum = zio_read(bp, tmpbuf, stack)) { return (errnum); } bp_array = tmpbuf; } return (0); } /* * mzap_lookup: Looks up property described by "name" and returns the value * in "value". * * Return: * 0 - success * errnum - failure */ static int mzap_lookup(mzap_phys_t *zapobj, int objsize, const char *name, uint64_t *value) { int i, chunks; mzap_ent_phys_t *mzap_ent = zapobj->mz_chunk; chunks = objsize / MZAP_ENT_LEN - 1; for (i = 0; i < chunks; i++) { if (grub_strcmp(mzap_ent[i].mze_name, name) == 0) { *value = mzap_ent[i].mze_value; return (0); } } return (ERR_FSYS_CORRUPT); } static uint64_t zap_hash(uint64_t salt, const char *name) { static uint64_t table[256]; const uint8_t *cp; uint8_t c; uint64_t crc = salt; if (table[128] == 0) { uint64_t *ct; int i, j; for (i = 0; i < 256; i++) { for (ct = table + i, *ct = i, j = 8; j > 0; j--) *ct = (*ct >> 1) ^ (-(*ct & 1) & ZFS_CRC64_POLY); } } if (crc == 0 || table[128] != ZFS_CRC64_POLY) { errnum = ERR_FSYS_CORRUPT; return (0); } for (cp = (const uint8_t *)name; (c = *cp) != '\0'; cp++) crc = (crc >> 8) ^ table[(crc ^ c) & 0xFF]; /* * Only use 28 bits, since we need 4 bits in the cookie for the * collision differentiator. We MUST use the high bits, since * those are the ones that we first pay attention to when * choosing the bucket. */ crc &= ~((1ULL << (64 - 28)) - 1); return (crc); } /* * Only to be used on 8-bit arrays. * array_len is actual len in bytes (not encoded le_value_length). * buf is null-terminated. */ static int zap_leaf_array_equal(zap_leaf_phys_t *l, int blksft, int chunk, int array_len, const char *buf) { int bseen = 0; while (bseen < array_len) { struct zap_leaf_array *la = &ZAP_LEAF_CHUNK(l, blksft, chunk).l_array; int toread = MIN(array_len - bseen, ZAP_LEAF_ARRAY_BYTES); if (chunk >= ZAP_LEAF_NUMCHUNKS(blksft)) return (0); if (zfs_bcmp(la->la_array, buf + bseen, toread) != 0) break; chunk = la->la_next; bseen += toread; } return (bseen == array_len); } /* * Given a zap_leaf_phys_t, walk thru the zap leaf chunks to get the * value for the property "name". * * Return: * 0 - success * errnum - failure */ static int zap_leaf_lookup(zap_leaf_phys_t *l, int blksft, uint64_t h, const char *name, uint64_t *value) { uint16_t chunk; struct zap_leaf_entry *le; /* Verify if this is a valid leaf block */ if (l->l_hdr.lh_block_type != ZBT_LEAF) return (ERR_FSYS_CORRUPT); if (l->l_hdr.lh_magic != ZAP_LEAF_MAGIC) return (ERR_FSYS_CORRUPT); for (chunk = l->l_hash[LEAF_HASH(blksft, h)]; chunk != CHAIN_END; chunk = le->le_next) { if (chunk >= ZAP_LEAF_NUMCHUNKS(blksft)) return (ERR_FSYS_CORRUPT); le = ZAP_LEAF_ENTRY(l, blksft, chunk); /* Verify the chunk entry */ if (le->le_type != ZAP_CHUNK_ENTRY) return (ERR_FSYS_CORRUPT); if (le->le_hash != h) continue; if (zap_leaf_array_equal(l, blksft, le->le_name_chunk, le->le_name_length, name)) { struct zap_leaf_array *la; uint8_t *ip; if (le->le_int_size != 8 || le->le_value_length != 1) return (ERR_FSYS_CORRUPT); /* get the uint64_t property value */ la = &ZAP_LEAF_CHUNK(l, blksft, le->le_value_chunk).l_array; ip = la->la_array; *value = (uint64_t)ip[0] << 56 | (uint64_t)ip[1] << 48 | (uint64_t)ip[2] << 40 | (uint64_t)ip[3] << 32 | (uint64_t)ip[4] << 24 | (uint64_t)ip[5] << 16 | (uint64_t)ip[6] << 8 | (uint64_t)ip[7]; return (0); } } return (ERR_FSYS_CORRUPT); } /* * Fat ZAP lookup * * Return: * 0 - success * errnum - failure */ static int fzap_lookup(dnode_phys_t *zap_dnode, zap_phys_t *zap, const char *name, uint64_t *value, char *stack) { zap_leaf_phys_t *l; uint64_t hash, idx, blkid; int blksft = zfs_log2(zap_dnode->dn_datablkszsec << DNODE_SHIFT); /* Verify if this is a fat zap header block */ if (zap->zap_magic != (uint64_t)ZAP_MAGIC || zap->zap_flags != 0) return (ERR_FSYS_CORRUPT); hash = zap_hash(zap->zap_salt, name); if (errnum) return (errnum); /* get block id from index */ if (zap->zap_ptrtbl.zt_numblks != 0) { /* external pointer tables not supported */ return (ERR_FSYS_CORRUPT); } idx = ZAP_HASH_IDX(hash, zap->zap_ptrtbl.zt_shift); blkid = ((uint64_t *)zap)[idx + (1<<(blksft-3-1))]; /* Get the leaf block */ l = (zap_leaf_phys_t *)stack; stack += 1<dn_datablkszsec << SPA_MINBLOCKSHIFT; stack += size; if ((errnum = dmu_read(zap_dnode, 0, zapbuf, stack)) != 0) return (errnum); block_type = *((uint64_t *)zapbuf); if (block_type == ZBT_MICRO) { return (mzap_lookup(zapbuf, size, name, val)); } else if (block_type == ZBT_HEADER) { /* this is a fat zap */ return (fzap_lookup(zap_dnode, zapbuf, name, val, stack)); } return (ERR_FSYS_CORRUPT); } typedef struct zap_attribute { int za_integer_length; uint64_t za_num_integers; uint64_t za_first_integer; char *za_name; } zap_attribute_t; typedef int (zap_cb_t)(zap_attribute_t *za, void *arg, char *stack); static int zap_iterate(dnode_phys_t *zap_dnode, zap_cb_t *cb, void *arg, char *stack) { uint32_t size = zap_dnode->dn_datablkszsec << SPA_MINBLOCKSHIFT; zap_attribute_t za; int i; mzap_phys_t *mzp = (mzap_phys_t *)stack; stack += size; if ((errnum = dmu_read(zap_dnode, 0, mzp, stack)) != 0) return (errnum); /* * Iteration over fatzap objects has not yet been implemented. * If we encounter a pool in which there are more features for * read than can fit inside a microzap (i.e., more than 2048 * features for read), we can add support for fatzap iteration. * For now, fail. */ if (mzp->mz_block_type != ZBT_MICRO) { grub_printf("feature information stored in fatzap, pool " "version not supported\n"); return (1); } za.za_integer_length = 8; za.za_num_integers = 1; for (i = 0; i < size / MZAP_ENT_LEN - 1; i++) { mzap_ent_phys_t *mzep = &mzp->mz_chunk[i]; int err; za.za_first_integer = mzep->mze_value; za.za_name = mzep->mze_name; err = cb(&za, arg, stack); if (err != 0) return (err); } return (0); } /* * Get the dnode of an object number from the metadnode of an object set. * * Input * mdn - metadnode to get the object dnode * objnum - object number for the object dnode * type - if nonzero, object must be of this type * buf - data buffer that holds the returning dnode * stack - scratch area * * Return: * 0 - success * errnum - failure */ static int dnode_get(dnode_phys_t *mdn, uint64_t objnum, uint8_t type, dnode_phys_t *buf, char *stack) { uint64_t blkid, blksz; /* the block id this object dnode is in */ int epbs; /* shift of number of dnodes in a block */ int idx; /* index within a block */ dnode_phys_t *dnbuf; blksz = mdn->dn_datablkszsec << SPA_MINBLOCKSHIFT; epbs = zfs_log2(blksz) - DNODE_SHIFT; blkid = objnum >> epbs; idx = objnum & ((1<= dnode_start && objnum < dnode_end) { grub_memmove(buf, &dnode_buf[idx], DNODE_SIZE); VERIFY_DN_TYPE(buf, type); return (0); } if (dnode_buf && blksz == 1<za_first_integer == 0) return (0); for (i = 0; names[i] != NULL; i++) { if (grub_strcmp(za->za_name, names[i]) == 0) { return (0); } } grub_printf("missing feature for read '%s'\n", za->za_name); return (ERR_NEWER_VERSION); } /* * Get the file dnode for a given file name where mdn is the meta dnode * for this ZFS object set. When found, place the file dnode in dn. * The 'path' argument will be mangled. * * Return: * 0 - success * errnum - failure */ static int dnode_get_path(dnode_phys_t *mdn, char *path, dnode_phys_t *dn, char *stack) { uint64_t objnum, version; char *cname, ch; if (errnum = dnode_get(mdn, MASTER_NODE_OBJ, DMU_OT_MASTER_NODE, dn, stack)) return (errnum); if (errnum = zap_lookup(dn, ZPL_VERSION_STR, &version, stack)) return (errnum); if (version > ZPL_VERSION) return (-1); if (errnum = zap_lookup(dn, ZFS_ROOT_OBJ, &objnum, stack)) return (errnum); if (errnum = dnode_get(mdn, objnum, DMU_OT_DIRECTORY_CONTENTS, dn, stack)) return (errnum); /* skip leading slashes */ while (*path == '/') path++; while (*path && !grub_isspace(*path)) { /* get the next component name */ cname = path; while (*path && !grub_isspace(*path) && *path != '/') path++; ch = *path; *path = 0; /* ensure null termination */ if (errnum = zap_lookup(dn, cname, &objnum, stack)) return (errnum); objnum = ZFS_DIRENT_OBJ(objnum); if (errnum = dnode_get(mdn, objnum, 0, dn, stack)) return (errnum); *path = ch; while (*path == '/') path++; } /* We found the dnode for this file. Verify if it is a plain file. */ VERIFY_DN_TYPE(dn, DMU_OT_PLAIN_FILE_CONTENTS); return (0); } /* * Get the default 'bootfs' property value from the rootpool. * * Return: * 0 - success * errnum -failure */ static int get_default_bootfsobj(dnode_phys_t *mosmdn, uint64_t *obj, char *stack) { uint64_t objnum = 0; dnode_phys_t *dn = (dnode_phys_t *)stack; stack += DNODE_SIZE; if (errnum = dnode_get(mosmdn, DMU_POOL_DIRECTORY_OBJECT, DMU_OT_OBJECT_DIRECTORY, dn, stack)) return (errnum); /* * find the object number for 'pool_props', and get the dnode * of the 'pool_props'. */ if (zap_lookup(dn, DMU_POOL_PROPS, &objnum, stack)) return (ERR_FILESYSTEM_NOT_FOUND); if (errnum = dnode_get(mosmdn, objnum, DMU_OT_POOL_PROPS, dn, stack)) return (errnum); if (zap_lookup(dn, ZPOOL_PROP_BOOTFS, &objnum, stack)) return (ERR_FILESYSTEM_NOT_FOUND); if (!objnum) return (ERR_FILESYSTEM_NOT_FOUND); *obj = objnum; return (0); } /* * List of pool features that the grub implementation of ZFS supports for * read. Note that features that are only required for write do not need * to be listed here since grub opens pools in read-only mode. * * When this list is updated the version number in usr/src/grub/capability * must be incremented to ensure the new grub gets installed. */ static const char *spa_feature_names[] = { "org.illumos:lz4_compress", "com.delphix:hole_birth", "com.delphix:extensible_dataset", "com.delphix:embedded_data", "org.open-zfs:large_blocks", NULL }; /* * Checks whether the MOS features that are active are supported by this * (GRUB's) implementation of ZFS. * * Return: * 0: Success. * errnum: Failure. */ static int check_mos_features(dnode_phys_t *mosmdn, char *stack) { uint64_t objnum; dnode_phys_t *dn; uint8_t error = 0; dn = (dnode_phys_t *)stack; stack += DNODE_SIZE; if ((errnum = dnode_get(mosmdn, DMU_POOL_DIRECTORY_OBJECT, DMU_OT_OBJECT_DIRECTORY, dn, stack)) != 0) return (errnum); /* * Find the object number for 'features_for_read' and retrieve its * corresponding dnode. Note that we don't check features_for_write * because GRUB is not opening the pool for write. */ if ((errnum = zap_lookup(dn, DMU_POOL_FEATURES_FOR_READ, &objnum, stack)) != 0) return (errnum); if ((errnum = dnode_get(mosmdn, objnum, DMU_OTN_ZAP_METADATA, dn, stack)) != 0) return (errnum); return (zap_iterate(dn, check_feature, spa_feature_names, stack)); } /* * Given a MOS metadnode, get the metadnode of a given filesystem name (fsname), * e.g. pool/rootfs, or a given object number (obj), e.g. the object number * of pool/rootfs. * * If no fsname and no obj are given, return the DSL_DIR metadnode. * If fsname is given, return its metadnode and its matching object number. * If only obj is given, return the metadnode for this object number. * * Return: * 0 - success * errnum - failure */ static int get_objset_mdn(dnode_phys_t *mosmdn, char *fsname, uint64_t *obj, dnode_phys_t *mdn, char *stack) { uint64_t objnum, headobj; char *cname, ch; blkptr_t *bp; objset_phys_t *osp; int issnapshot = 0; char *snapname; if (fsname == NULL && obj) { headobj = *obj; goto skip; } if (errnum = dnode_get(mosmdn, DMU_POOL_DIRECTORY_OBJECT, DMU_OT_OBJECT_DIRECTORY, mdn, stack)) return (errnum); if (errnum = zap_lookup(mdn, DMU_POOL_ROOT_DATASET, &objnum, stack)) return (errnum); if (errnum = dnode_get(mosmdn, objnum, 0, mdn, stack)) return (errnum); if (fsname == NULL) { headobj = ((dsl_dir_phys_t *)DN_BONUS(mdn))->dd_head_dataset_obj; goto skip; } /* take out the pool name */ while (*fsname && !grub_isspace(*fsname) && *fsname != '/') fsname++; while (*fsname && !grub_isspace(*fsname)) { uint64_t childobj; while (*fsname == '/') fsname++; cname = fsname; while (*fsname && !grub_isspace(*fsname) && *fsname != '/') fsname++; ch = *fsname; *fsname = 0; snapname = cname; while (*snapname && !grub_isspace(*snapname) && *snapname != '@') snapname++; if (*snapname == '@') { issnapshot = 1; *snapname = 0; } childobj = ((dsl_dir_phys_t *)DN_BONUS(mdn))->dd_child_dir_zapobj; if (errnum = dnode_get(mosmdn, childobj, DMU_OT_DSL_DIR_CHILD_MAP, mdn, stack)) return (errnum); if (zap_lookup(mdn, cname, &objnum, stack)) return (ERR_FILESYSTEM_NOT_FOUND); if (errnum = dnode_get(mosmdn, objnum, 0, mdn, stack)) return (errnum); *fsname = ch; if (issnapshot) *snapname = '@'; } headobj = ((dsl_dir_phys_t *)DN_BONUS(mdn))->dd_head_dataset_obj; if (obj) *obj = headobj; skip: if (errnum = dnode_get(mosmdn, headobj, 0, mdn, stack)) return (errnum); if (issnapshot) { uint64_t snapobj; snapobj = ((dsl_dataset_phys_t *)DN_BONUS(mdn))-> ds_snapnames_zapobj; if (errnum = dnode_get(mosmdn, snapobj, DMU_OT_DSL_DS_SNAP_MAP, mdn, stack)) return (errnum); if (zap_lookup(mdn, snapname + 1, &headobj, stack)) return (ERR_FILESYSTEM_NOT_FOUND); if (errnum = dnode_get(mosmdn, headobj, 0, mdn, stack)) return (errnum); if (obj) *obj = headobj; } bp = &((dsl_dataset_phys_t *)DN_BONUS(mdn))->ds_bp; osp = (objset_phys_t *)stack; stack += sizeof (objset_phys_t); if (errnum = zio_read(bp, osp, stack)) return (errnum); grub_memmove((char *)mdn, (char *)&osp->os_meta_dnode, DNODE_SIZE); return (0); } /* * For a given XDR packed nvlist, verify the first 4 bytes and move on. * * An XDR packed nvlist is encoded as (comments from nvs_xdr_create) : * * encoding method/host endian (4 bytes) * nvl_version (4 bytes) * nvl_nvflag (4 bytes) * encoded nvpairs: * encoded size of the nvpair (4 bytes) * decoded size of the nvpair (4 bytes) * name string size (4 bytes) * name string data (sizeof(NV_ALIGN4(string)) * data type (4 bytes) * # of elements in the nvpair (4 bytes) * data * 2 zero's for the last nvpair * (end of the entire list) (8 bytes) * * Return: * 0 - success * 1 - failure */ static int nvlist_unpack(char *nvlist, char **out) { /* Verify if the 1st and 2nd byte in the nvlist are valid. */ if (nvlist[0] != NV_ENCODE_XDR || nvlist[1] != HOST_ENDIAN) return (1); *out = nvlist + 4; return (0); } static char * nvlist_array(char *nvlist, int index) { int i, encode_size; for (i = 0; i < index; i++) { /* skip the header, nvl_version, and nvl_nvflag */ nvlist = nvlist + 4 * 2; while (encode_size = BSWAP_32(*(uint32_t *)nvlist)) nvlist += encode_size; /* goto the next nvpair */ nvlist = nvlist + 4 * 2; /* skip the ending 2 zeros - 8 bytes */ } return (nvlist); } /* * The nvlist_next_nvpair() function returns a handle to the next nvpair in the * list following nvpair. If nvpair is NULL, the first pair is returned. If * nvpair is the last pair in the nvlist, NULL is returned. */ static char * nvlist_next_nvpair(char *nvl, char *nvpair) { char *cur, *prev; int encode_size; if (nvl == NULL) return (NULL); if (nvpair == NULL) { /* skip over nvl_version and nvl_nvflag */ nvpair = nvl + 4 * 2; } else { /* skip to the next nvpair */ encode_size = BSWAP_32(*(uint32_t *)nvpair); nvpair += encode_size; } /* 8 bytes of 0 marks the end of the list */ if (*(uint64_t *)nvpair == 0) return (NULL); return (nvpair); } /* * This function returns 0 on success and 1 on failure. On success, a string * containing the name of nvpair is saved in buf. */ static int nvpair_name(char *nvp, char *buf, int buflen) { int len; /* skip over encode/decode size */ nvp += 4 * 2; len = BSWAP_32(*(uint32_t *)nvp); if (buflen < len + 1) return (1); grub_memmove(buf, nvp + 4, len); buf[len] = '\0'; return (0); } /* * This function retrieves the value of the nvpair in the form of enumerated * type data_type_t. This is used to determine the appropriate type to pass to * nvpair_value(). */ static int nvpair_type(char *nvp) { int name_len, type; /* skip over encode/decode size */ nvp += 4 * 2; /* skip over name_len */ name_len = BSWAP_32(*(uint32_t *)nvp); nvp += 4; /* skip over name */ nvp = nvp + ((name_len + 3) & ~3); /* align */ type = BSWAP_32(*(uint32_t *)nvp); return (type); } static int nvpair_value(char *nvp, void *val, int valtype, int *nelmp) { int name_len, type, slen; char *strval = val; uint64_t *intval = val; /* skip over encode/decode size */ nvp += 4 * 2; /* skip over name_len */ name_len = BSWAP_32(*(uint32_t *)nvp); nvp += 4; /* skip over name */ nvp = nvp + ((name_len + 3) & ~3); /* align */ /* skip over type */ type = BSWAP_32(*(uint32_t *)nvp); nvp += 4; if (type == valtype) { int nelm; nelm = BSWAP_32(*(uint32_t *)nvp); if (valtype != DATA_TYPE_BOOLEAN && nelm < 1) return (1); nvp += 4; switch (valtype) { case DATA_TYPE_BOOLEAN: return (0); case DATA_TYPE_STRING: slen = BSWAP_32(*(uint32_t *)nvp); nvp += 4; grub_memmove(strval, nvp, slen); strval[slen] = '\0'; return (0); case DATA_TYPE_UINT64: *intval = BSWAP_64(*(uint64_t *)nvp); return (0); case DATA_TYPE_NVLIST: *(void **)val = (void *)nvp; return (0); case DATA_TYPE_NVLIST_ARRAY: *(void **)val = (void *)nvp; if (nelmp) *nelmp = nelm; return (0); } } return (1); } static int nvlist_lookup_value(char *nvlist, char *name, void *val, int valtype, int *nelmp) { char *nvpair; for (nvpair = nvlist_next_nvpair(nvlist, NULL); nvpair != NULL; nvpair = nvlist_next_nvpair(nvlist, nvpair)) { int name_len = BSWAP_32(*(uint32_t *)(nvpair + 4 * 2)); char *nvp_name = nvpair + 4 * 3; if ((grub_strncmp(nvp_name, name, name_len) == 0) && nvpair_type(nvpair) == valtype) { return (nvpair_value(nvpair, val, valtype, nelmp)); } } return (1); } /* * Check if this vdev is online and is in a good state. */ static int vdev_validate(char *nv) { uint64_t ival; if (nvlist_lookup_value(nv, ZPOOL_CONFIG_OFFLINE, &ival, DATA_TYPE_UINT64, NULL) == 0 || nvlist_lookup_value(nv, ZPOOL_CONFIG_FAULTED, &ival, DATA_TYPE_UINT64, NULL) == 0 || nvlist_lookup_value(nv, ZPOOL_CONFIG_REMOVED, &ival, DATA_TYPE_UINT64, NULL) == 0) return (ERR_DEV_VALUES); return (0); } /* * Get a valid vdev pathname/devid from the boot device. * The caller should already allocate MAXPATHLEN memory for bootpath and devid. */ static int vdev_get_bootpath(char *nv, uint64_t inguid, char *devid, char *bootpath, int is_spare) { char type[16]; if (nvlist_lookup_value(nv, ZPOOL_CONFIG_TYPE, &type, DATA_TYPE_STRING, NULL)) return (ERR_FSYS_CORRUPT); if (grub_strcmp(type, VDEV_TYPE_DISK) == 0) { uint64_t guid; if (vdev_validate(nv) != 0) return (ERR_NO_BOOTPATH); if (nvlist_lookup_value(nv, ZPOOL_CONFIG_GUID, &guid, DATA_TYPE_UINT64, NULL) != 0) return (ERR_NO_BOOTPATH); if (guid != inguid) return (ERR_NO_BOOTPATH); /* for a spare vdev, pick the disk labeled with "is_spare" */ if (is_spare) { uint64_t spare = 0; (void) nvlist_lookup_value(nv, ZPOOL_CONFIG_IS_SPARE, &spare, DATA_TYPE_UINT64, NULL); if (!spare) return (ERR_NO_BOOTPATH); } if (nvlist_lookup_value(nv, ZPOOL_CONFIG_PHYS_PATH, bootpath, DATA_TYPE_STRING, NULL) != 0) bootpath[0] = '\0'; if (nvlist_lookup_value(nv, ZPOOL_CONFIG_DEVID, devid, DATA_TYPE_STRING, NULL) != 0) devid[0] = '\0'; if (grub_strlen(bootpath) >= MAXPATHLEN || grub_strlen(devid) >= MAXPATHLEN) return (ERR_WONT_FIT); return (0); } else if (grub_strcmp(type, VDEV_TYPE_MIRROR) == 0 || grub_strcmp(type, VDEV_TYPE_REPLACING) == 0 || (is_spare = (grub_strcmp(type, VDEV_TYPE_SPARE) == 0))) { int nelm, i; char *child; if (nvlist_lookup_value(nv, ZPOOL_CONFIG_CHILDREN, &child, DATA_TYPE_NVLIST_ARRAY, &nelm)) return (ERR_FSYS_CORRUPT); for (i = 0; i < nelm; i++) { char *child_i; child_i = nvlist_array(child, i); if (vdev_get_bootpath(child_i, inguid, devid, bootpath, is_spare) == 0) return (0); } } return (ERR_NO_BOOTPATH); } /* * Check the disk label information and retrieve needed vdev name-value pairs. * * Return: * 0 - success * ERR_* - failure */ static int check_pool_label(uint64_t sector, char *stack, char *outdevid, char *outpath, uint64_t *outguid, uint64_t *outashift, uint64_t *outversion) { vdev_phys_t *vdev; uint64_t pool_state, txg = 0; char *nvlist, *nv, *features; uint64_t diskguid; sector += (VDEV_SKIP_SIZE >> SPA_MINBLOCKSHIFT); /* Read in the vdev name-value pair list (112K). */ if (devread(sector, 0, VDEV_PHYS_SIZE, stack) == 0) return (ERR_READ); vdev = (vdev_phys_t *)stack; stack += sizeof (vdev_phys_t); if (nvlist_unpack(vdev->vp_nvlist, &nvlist)) return (ERR_FSYS_CORRUPT); if (nvlist_lookup_value(nvlist, ZPOOL_CONFIG_POOL_STATE, &pool_state, DATA_TYPE_UINT64, NULL)) return (ERR_FSYS_CORRUPT); if (pool_state == POOL_STATE_DESTROYED) return (ERR_FILESYSTEM_NOT_FOUND); if (nvlist_lookup_value(nvlist, ZPOOL_CONFIG_POOL_NAME, current_rootpool, DATA_TYPE_STRING, NULL)) return (ERR_FSYS_CORRUPT); if (nvlist_lookup_value(nvlist, ZPOOL_CONFIG_POOL_TXG, &txg, DATA_TYPE_UINT64, NULL)) return (ERR_FSYS_CORRUPT); /* not an active device */ if (txg == 0) return (ERR_NO_BOOTPATH); if (nvlist_lookup_value(nvlist, ZPOOL_CONFIG_VERSION, outversion, DATA_TYPE_UINT64, NULL)) return (ERR_FSYS_CORRUPT); if (!SPA_VERSION_IS_SUPPORTED(*outversion)) return (ERR_NEWER_VERSION); if (nvlist_lookup_value(nvlist, ZPOOL_CONFIG_VDEV_TREE, &nv, DATA_TYPE_NVLIST, NULL)) return (ERR_FSYS_CORRUPT); if (nvlist_lookup_value(nvlist, ZPOOL_CONFIG_GUID, &diskguid, DATA_TYPE_UINT64, NULL)) return (ERR_FSYS_CORRUPT); if (nvlist_lookup_value(nv, ZPOOL_CONFIG_ASHIFT, outashift, DATA_TYPE_UINT64, NULL) != 0) return (ERR_FSYS_CORRUPT); if (vdev_get_bootpath(nv, diskguid, outdevid, outpath, 0)) return (ERR_NO_BOOTPATH); if (nvlist_lookup_value(nvlist, ZPOOL_CONFIG_POOL_GUID, outguid, DATA_TYPE_UINT64, NULL)) return (ERR_FSYS_CORRUPT); if (nvlist_lookup_value(nvlist, ZPOOL_CONFIG_FEATURES_FOR_READ, &features, DATA_TYPE_NVLIST, NULL) == 0) { char *nvp; char *name = stack; stack += MAXNAMELEN; for (nvp = nvlist_next_nvpair(features, NULL); nvp != NULL; nvp = nvlist_next_nvpair(features, nvp)) { zap_attribute_t za; if (nvpair_name(nvp, name, MAXNAMELEN) != 0) return (ERR_FSYS_CORRUPT); za.za_integer_length = 8; za.za_num_integers = 1; za.za_first_integer = 1; za.za_name = name; if (check_feature(&za, spa_feature_names, stack) != 0) return (ERR_NEWER_VERSION); } } return (0); } /* * zfs_mount() locates a valid uberblock of the root pool and read in its MOS * to the memory address MOS. * * Return: * 1 - success * 0 - failure */ int zfs_mount(void) { char *stack, *ub_array; int label = 0; uberblock_t *ubbest; objset_phys_t *osp; char tmp_bootpath[MAXNAMELEN]; char tmp_devid[MAXNAMELEN]; uint64_t tmp_guid, ashift, version; uint64_t adjpl = (uint64_t)part_length << SPA_MINBLOCKSHIFT; int err = errnum; /* preserve previous errnum state */ /* if it's our first time here, zero the best uberblock out */ if (best_drive == 0 && best_part == 0 && find_best_root) { grub_memset(¤t_uberblock, 0, sizeof (uberblock_t)); pool_guid = 0; } stackbase = ZFS_SCRATCH; stack = stackbase; ub_array = stack; stack += VDEV_UBERBLOCK_RING; osp = (objset_phys_t *)stack; stack += sizeof (objset_phys_t); adjpl = P2ALIGN(adjpl, (uint64_t)sizeof (vdev_label_t)); for (label = 0; label < VDEV_LABELS; label++) { /* * some eltorito stacks don't give us a size and * we end up setting the size to MAXUINT, further * some of these devices stop working once a single * read past the end has been issued. Checking * for a maximum part_length and skipping the backup * labels at the end of the slice/partition/device * avoids breaking down on such devices. */ if (part_length == MAXUINT && label == 2) break; uint64_t sector = vdev_label_start(adjpl, label) >> SPA_MINBLOCKSHIFT; /* Read in the uberblock ring (128K). */ if (devread(sector + ((VDEV_SKIP_SIZE + VDEV_PHYS_SIZE) >> SPA_MINBLOCKSHIFT), 0, VDEV_UBERBLOCK_RING, ub_array) == 0) continue; if (check_pool_label(sector, stack, tmp_devid, tmp_bootpath, &tmp_guid, &ashift, &version)) continue; if (pool_guid == 0) pool_guid = tmp_guid; if ((ubbest = find_bestub(ub_array, ashift, sector)) == NULL || zio_read(&ubbest->ub_rootbp, osp, stack) != 0) continue; VERIFY_OS_TYPE(osp, DMU_OST_META); if (version >= SPA_VERSION_FEATURES && check_mos_features(&osp->os_meta_dnode, stack) != 0) continue; if (find_best_root && ((pool_guid != tmp_guid) || vdev_uberblock_compare(ubbest, &(current_uberblock)) <= 0)) continue; /* Got the MOS. Save it at the memory addr MOS. */ grub_memmove(MOS, &osp->os_meta_dnode, DNODE_SIZE); grub_memmove(¤t_uberblock, ubbest, sizeof (uberblock_t)); grub_memmove(current_bootpath, tmp_bootpath, MAXNAMELEN); grub_memmove(current_devid, tmp_devid, grub_strlen(tmp_devid)); is_zfs_mount = 1; return (1); } /* * While some fs impls. (tftp) rely on setting and keeping * global errnums set, others won't reset it and will break * when issuing rawreads. The goal here is to simply not * have zfs mount attempts impact the previous state. */ errnum = err; return (0); } /* * zfs_open() locates a file in the rootpool by following the * MOS and places the dnode of the file in the memory address DNODE. * * Return: * 1 - success * 0 - failure */ int zfs_open(char *filename) { char *stack; dnode_phys_t *mdn; file_buf = NULL; stackbase = ZFS_SCRATCH; stack = stackbase; mdn = (dnode_phys_t *)stack; stack += sizeof (dnode_phys_t); dnode_mdn = NULL; dnode_buf = (dnode_phys_t *)stack; stack += 1<dn_bonustype == DMU_OT_SA) { sa_hdr_phys_t *sahdrp; int hdrsize; if (DNODE->dn_bonuslen != 0) { sahdrp = (sa_hdr_phys_t *)DN_BONUS(DNODE); } else { if (DNODE->dn_flags & DNODE_FLAG_SPILL_BLKPTR) { blkptr_t *bp = &DNODE->dn_spill; void *buf; buf = (void *)stack; stack += BP_GET_LSIZE(bp); /* reset errnum to rawread() failure */ errnum = 0; if (zio_read(bp, buf, stack) != 0) { return (0); } sahdrp = buf; } else { errnum = ERR_FSYS_CORRUPT; return (0); } } hdrsize = SA_HDR_SIZE(sahdrp); filemax = *(uint64_t *)((char *)sahdrp + hdrsize + SA_SIZE_OFFSET); } else { filemax = ((znode_phys_t *)DN_BONUS(DNODE))->zp_size; } filepos = 0; dnode_buf = NULL; return (1); } /* * zfs_read reads in the data blocks pointed by the DNODE. * * Return: * len - the length successfully read in to the buffer * 0 - failure */ int zfs_read(char *buf, int len) { char *stack; int blksz, length, movesize; if (file_buf == NULL) { file_buf = stackbase; stackbase += SPA_MAXBLOCKSIZE; file_start = file_end = 0; } stack = stackbase; /* * If offset is in memory, move it into the buffer provided and return. */ if (filepos >= file_start && filepos+len <= file_end) { grub_memmove(buf, file_buf + filepos - file_start, len); filepos += len; return (len); } blksz = DNODE->dn_datablkszsec << SPA_MINBLOCKSHIFT; /* * Note: for GRUB, SPA_MAXBLOCKSIZE is 128KB. There is not enough * memory to allocate the new max blocksize (16MB), so while * GRUB understands the large_blocks on-disk feature, it can't * actually read large blocks. */ if (blksz > SPA_MAXBLOCKSIZE) { grub_printf("blocks larger than 128K are not supported\n"); return (0); } /* * Entire Dnode is too big to fit into the space available. We * will need to read it in chunks. This could be optimized to * read in as large a chunk as there is space available, but for * now, this only reads in one data block at a time. */ length = len; while (length) { /* * Find requested blkid and the offset within that block. */ uint64_t blkid = filepos / blksz; if (errnum = dmu_read(DNODE, blkid, file_buf, stack)) return (0); file_start = blkid * blksz; file_end = file_start + blksz; movesize = MIN(length, file_end - filepos); grub_memmove(buf, file_buf + filepos - file_start, movesize); buf += movesize; length -= movesize; filepos += movesize; } return (len); } /* * No-Op */ int zfs_embed(int *start_sector, int needed_sectors) { return (1); } #endif /* FSYS_ZFS */