1 /* 2 * GRUB -- GRand Unified Bootloader 3 * Copyright (C) 1999,2000,2001,2002,2003,2004 Free Software Foundation, Inc. 4 * 5 * SPDX-License-Identifier: GPL-2.0+ 6 */ 7 /* 8 * Copyright (c) 2008, 2011, Oracle and/or its affiliates. All rights reserved. 9 */ 10 11 #ifndef ZFS_SPA_HEADER 12 #define ZFS_SPA_HEADER 1 13 14 15 /* 16 * General-purpose 32-bit and 64-bit bitfield encodings. 17 */ 18 #define BF32_DECODE(x, low, len) P2PHASE((x) >> (low), 1U << (len)) 19 #define BF64_DECODE(x, low, len) P2PHASE((x) >> (low), 1ULL << (len)) 20 #define BF32_ENCODE(x, low, len) (P2PHASE((x), 1U << (len)) << (low)) 21 #define BF64_ENCODE(x, low, len) (P2PHASE((x), 1ULL << (len)) << (low)) 22 23 #define BF32_GET(x, low, len) BF32_DECODE(x, low, len) 24 #define BF64_GET(x, low, len) BF64_DECODE(x, low, len) 25 26 #define BF32_SET(x, low, len, val) \ 27 ((x) ^= BF32_ENCODE((x >> low) ^ (val), low, len)) 28 #define BF64_SET(x, low, len, val) \ 29 ((x) ^= BF64_ENCODE((x >> low) ^ (val), low, len)) 30 31 #define BF32_GET_SB(x, low, len, shift, bias) \ 32 ((BF32_GET(x, low, len) + (bias)) << (shift)) 33 #define BF64_GET_SB(x, low, len, shift, bias) \ 34 ((BF64_GET(x, low, len) + (bias)) << (shift)) 35 36 #define BF32_SET_SB(x, low, len, shift, bias, val) \ 37 BF32_SET(x, low, len, ((val) >> (shift)) - (bias)) 38 #define BF64_SET_SB(x, low, len, shift, bias, val) \ 39 BF64_SET(x, low, len, ((val) >> (shift)) - (bias)) 40 41 /* 42 * We currently support nine block sizes, from 512 bytes to 128K. 43 * We could go higher, but the benefits are near-zero and the cost 44 * of COWing a giant block to modify one byte would become excessive. 45 */ 46 #define SPA_MINBLOCKSHIFT 9 47 #define SPA_MAXBLOCKSHIFT 17 48 #define SPA_MINBLOCKSIZE (1ULL << SPA_MINBLOCKSHIFT) 49 #define SPA_MAXBLOCKSIZE (1ULL << SPA_MAXBLOCKSHIFT) 50 51 #define SPA_BLOCKSIZES (SPA_MAXBLOCKSHIFT - SPA_MINBLOCKSHIFT + 1) 52 53 /* 54 * Size of block to hold the configuration data (a packed nvlist) 55 */ 56 #define SPA_CONFIG_BLOCKSIZE (1 << 14) 57 58 /* 59 * The DVA size encodings for LSIZE and PSIZE support blocks up to 32MB. 60 * The ASIZE encoding should be at least 64 times larger (6 more bits) 61 * to support up to 4-way RAID-Z mirror mode with worst-case gang block 62 * overhead, three DVAs per bp, plus one more bit in case we do anything 63 * else that expands the ASIZE. 64 */ 65 #define SPA_LSIZEBITS 16 /* LSIZE up to 32M (2^16 * 512) */ 66 #define SPA_PSIZEBITS 16 /* PSIZE up to 32M (2^16 * 512) */ 67 #define SPA_ASIZEBITS 24 /* ASIZE up to 64 times larger */ 68 69 /* 70 * All SPA data is represented by 128-bit data virtual addresses (DVAs). 71 * The members of the dva_t should be considered opaque outside the SPA. 72 */ 73 typedef struct dva { 74 uint64_t dva_word[2]; 75 } dva_t; 76 77 /* 78 * Each block has a 256-bit checksum -- strong enough for cryptographic hashes. 79 */ 80 typedef struct zio_cksum { 81 uint64_t zc_word[4]; 82 } zio_cksum_t; 83 84 /* 85 * Each block is described by its DVAs, time of birth, checksum, etc. 86 * The word-by-word, bit-by-bit layout of the blkptr is as follows: 87 * 88 * 64 56 48 40 32 24 16 8 0 89 * +-------+-------+-------+-------+-------+-------+-------+-------+ 90 * 0 | vdev1 | GRID | ASIZE | 91 * +-------+-------+-------+-------+-------+-------+-------+-------+ 92 * 1 |G| offset1 | 93 * +-------+-------+-------+-------+-------+-------+-------+-------+ 94 * 2 | vdev2 | GRID | ASIZE | 95 * +-------+-------+-------+-------+-------+-------+-------+-------+ 96 * 3 |G| offset2 | 97 * +-------+-------+-------+-------+-------+-------+-------+-------+ 98 * 4 | vdev3 | GRID | ASIZE | 99 * +-------+-------+-------+-------+-------+-------+-------+-------+ 100 * 5 |G| offset3 | 101 * +-------+-------+-------+-------+-------+-------+-------+-------+ 102 * 6 |BDX|lvl| type | cksum | comp | PSIZE | LSIZE | 103 * +-------+-------+-------+-------+-------+-------+-------+-------+ 104 * 7 | padding | 105 * +-------+-------+-------+-------+-------+-------+-------+-------+ 106 * 8 | padding | 107 * +-------+-------+-------+-------+-------+-------+-------+-------+ 108 * 9 | physical birth txg | 109 * +-------+-------+-------+-------+-------+-------+-------+-------+ 110 * a | logical birth txg | 111 * +-------+-------+-------+-------+-------+-------+-------+-------+ 112 * b | fill count | 113 * +-------+-------+-------+-------+-------+-------+-------+-------+ 114 * c | checksum[0] | 115 * +-------+-------+-------+-------+-------+-------+-------+-------+ 116 * d | checksum[1] | 117 * +-------+-------+-------+-------+-------+-------+-------+-------+ 118 * e | checksum[2] | 119 * +-------+-------+-------+-------+-------+-------+-------+-------+ 120 * f | checksum[3] | 121 * +-------+-------+-------+-------+-------+-------+-------+-------+ 122 * 123 * Legend: 124 * 125 * vdev virtual device ID 126 * offset offset into virtual device 127 * LSIZE logical size 128 * PSIZE physical size (after compression) 129 * ASIZE allocated size (including RAID-Z parity and gang block headers) 130 * GRID RAID-Z layout information (reserved for future use) 131 * cksum checksum function 132 * comp compression function 133 * G gang block indicator 134 * B byteorder (endianness) 135 * D dedup 136 * X unused 137 * lvl level of indirection 138 * type DMU object type 139 * phys birth txg of block allocation; zero if same as logical birth txg 140 * log. birth transaction group in which the block was logically born 141 * fill count number of non-zero blocks under this bp 142 * checksum[4] 256-bit checksum of the data this bp describes 143 */ 144 #define SPA_BLKPTRSHIFT 7 /* blkptr_t is 128 bytes */ 145 #define SPA_DVAS_PER_BP 3 /* Number of DVAs in a bp */ 146 147 typedef struct blkptr { 148 dva_t blk_dva[SPA_DVAS_PER_BP]; /* Data Virtual Addresses */ 149 uint64_t blk_prop; /* size, compression, type, etc */ 150 uint64_t blk_pad[2]; /* Extra space for the future */ 151 uint64_t blk_phys_birth; /* txg when block was allocated */ 152 uint64_t blk_birth; /* transaction group at birth */ 153 uint64_t blk_fill; /* fill count */ 154 zio_cksum_t blk_cksum; /* 256-bit checksum */ 155 } blkptr_t; 156 157 /* 158 * Macros to get and set fields in a bp or DVA. 159 */ 160 #define DVA_GET_ASIZE(dva) \ 161 BF64_GET_SB((dva)->dva_word[0], 0, 24, SPA_MINBLOCKSHIFT, 0) 162 #define DVA_SET_ASIZE(dva, x) \ 163 BF64_SET_SB((dva)->dva_word[0], 0, 24, SPA_MINBLOCKSHIFT, 0, x) 164 165 #define DVA_GET_GRID(dva) BF64_GET((dva)->dva_word[0], 24, 8) 166 #define DVA_SET_GRID(dva, x) BF64_SET((dva)->dva_word[0], 24, 8, x) 167 168 #define DVA_GET_VDEV(dva) BF64_GET((dva)->dva_word[0], 32, 32) 169 #define DVA_SET_VDEV(dva, x) BF64_SET((dva)->dva_word[0], 32, 32, x) 170 171 #define DVA_GET_GANG(dva) BF64_GET((dva)->dva_word[1], 63, 1) 172 #define DVA_SET_GANG(dva, x) BF64_SET((dva)->dva_word[1], 63, 1, x) 173 174 #define BP_GET_LSIZE(bp) \ 175 BF64_GET_SB((bp)->blk_prop, 0, 16, SPA_MINBLOCKSHIFT, 1) 176 #define BP_SET_LSIZE(bp, x) \ 177 BF64_SET_SB((bp)->blk_prop, 0, 16, SPA_MINBLOCKSHIFT, 1, x) 178 179 #define BP_GET_COMPRESS(bp) BF64_GET((bp)->blk_prop, 32, 8) 180 #define BP_SET_COMPRESS(bp, x) BF64_SET((bp)->blk_prop, 32, 8, x) 181 182 #define BP_GET_CHECKSUM(bp) BF64_GET((bp)->blk_prop, 40, 8) 183 #define BP_SET_CHECKSUM(bp, x) BF64_SET((bp)->blk_prop, 40, 8, x) 184 185 #define BP_GET_TYPE(bp) BF64_GET((bp)->blk_prop, 48, 8) 186 #define BP_SET_TYPE(bp, x) BF64_SET((bp)->blk_prop, 48, 8, x) 187 188 #define BP_GET_LEVEL(bp) BF64_GET((bp)->blk_prop, 56, 5) 189 #define BP_SET_LEVEL(bp, x) BF64_SET((bp)->blk_prop, 56, 5, x) 190 191 #define BP_GET_PROP_BIT_61(bp) BF64_GET((bp)->blk_prop, 61, 1) 192 #define BP_SET_PROP_BIT_61(bp, x) BF64_SET((bp)->blk_prop, 61, 1, x) 193 194 #define BP_GET_DEDUP(bp) BF64_GET((bp)->blk_prop, 62, 1) 195 #define BP_SET_DEDUP(bp, x) BF64_SET((bp)->blk_prop, 62, 1, x) 196 197 #define BP_GET_BYTEORDER(bp) (0 - BF64_GET((bp)->blk_prop, 63, 1)) 198 #define BP_SET_BYTEORDER(bp, x) BF64_SET((bp)->blk_prop, 63, 1, x) 199 200 #define BP_PHYSICAL_BIRTH(bp) \ 201 ((bp)->blk_phys_birth ? (bp)->blk_phys_birth : (bp)->blk_birth) 202 203 #define BP_SET_BIRTH(bp, logical, physical) \ 204 { \ 205 (bp)->blk_birth = (logical); \ 206 (bp)->blk_phys_birth = ((logical) == (physical) ? 0 : (physical)); \ 207 } 208 209 #define BP_GET_ASIZE(bp) \ 210 (DVA_GET_ASIZE(&(bp)->blk_dva[0]) + DVA_GET_ASIZE(&(bp)->blk_dva[1]) + \ 211 DVA_GET_ASIZE(&(bp)->blk_dva[2])) 212 213 #define BP_GET_UCSIZE(bp) \ 214 ((BP_GET_LEVEL(bp) > 0 || dmu_ot[BP_GET_TYPE(bp)].ot_metadata) ? \ 215 BP_GET_PSIZE(bp) : BP_GET_LSIZE(bp)); 216 217 #define BP_GET_NDVAS(bp) \ 218 (!!DVA_GET_ASIZE(&(bp)->blk_dva[0]) + \ 219 !!DVA_GET_ASIZE(&(bp)->blk_dva[1]) + \ 220 !!DVA_GET_ASIZE(&(bp)->blk_dva[2])) 221 222 #define BP_COUNT_GANG(bp) \ 223 (DVA_GET_GANG(&(bp)->blk_dva[0]) + \ 224 DVA_GET_GANG(&(bp)->blk_dva[1]) + \ 225 DVA_GET_GANG(&(bp)->blk_dva[2])) 226 227 #define DVA_EQUAL(dva1, dva2) \ 228 ((dva1)->dva_word[1] == (dva2)->dva_word[1] && \ 229 (dva1)->dva_word[0] == (dva2)->dva_word[0]) 230 231 #define BP_EQUAL(bp1, bp2) \ 232 (BP_PHYSICAL_BIRTH(bp1) == BP_PHYSICAL_BIRTH(bp2) && \ 233 DVA_EQUAL(&(bp1)->blk_dva[0], &(bp2)->blk_dva[0]) && \ 234 DVA_EQUAL(&(bp1)->blk_dva[1], &(bp2)->blk_dva[1]) && \ 235 DVA_EQUAL(&(bp1)->blk_dva[2], &(bp2)->blk_dva[2])) 236 237 #define ZIO_CHECKSUM_EQUAL(zc1, zc2) \ 238 (0 == (((zc1).zc_word[0] - (zc2).zc_word[0]) | \ 239 ((zc1).zc_word[1] - (zc2).zc_word[1]) | \ 240 ((zc1).zc_word[2] - (zc2).zc_word[2]) | \ 241 ((zc1).zc_word[3] - (zc2).zc_word[3]))) 242 243 #define DVA_IS_VALID(dva) (DVA_GET_ASIZE(dva) != 0) 244 245 #define ZIO_SET_CHECKSUM(zcp, w0, w1, w2, w3) \ 246 { \ 247 (zcp)->zc_word[0] = w0; \ 248 (zcp)->zc_word[1] = w1; \ 249 (zcp)->zc_word[2] = w2; \ 250 (zcp)->zc_word[3] = w3; \ 251 } 252 253 #define BP_IDENTITY(bp) (&(bp)->blk_dva[0]) 254 #define BP_IS_GANG(bp) DVA_GET_GANG(BP_IDENTITY(bp)) 255 #define BP_IS_HOLE(bp) ((bp)->blk_birth == 0) 256 257 /* BP_IS_RAIDZ(bp) assumes no block compression */ 258 #define BP_IS_RAIDZ(bp) (DVA_GET_ASIZE(&(bp)->blk_dva[0]) > \ 259 BP_GET_PSIZE(bp)) 260 261 #define BP_ZERO(bp) \ 262 { \ 263 (bp)->blk_dva[0].dva_word[0] = 0; \ 264 (bp)->blk_dva[0].dva_word[1] = 0; \ 265 (bp)->blk_dva[1].dva_word[0] = 0; \ 266 (bp)->blk_dva[1].dva_word[1] = 0; \ 267 (bp)->blk_dva[2].dva_word[0] = 0; \ 268 (bp)->blk_dva[2].dva_word[1] = 0; \ 269 (bp)->blk_prop = 0; \ 270 (bp)->blk_pad[0] = 0; \ 271 (bp)->blk_pad[1] = 0; \ 272 (bp)->blk_phys_birth = 0; \ 273 (bp)->blk_birth = 0; \ 274 (bp)->blk_fill = 0; \ 275 ZIO_SET_CHECKSUM(&(bp)->blk_cksum, 0, 0, 0, 0); \ 276 } 277 278 #define BP_SPRINTF_LEN 320 279 280 #endif /* ! ZFS_SPA_HEADER */ 281