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