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 (c) 2008, 2011, Oracle and/or its affiliates. All rights reserved. 21 */ 22 23 #ifndef ZFS_SPA_HEADER 24 #define ZFS_SPA_HEADER 1 25 26 27 /* 28 * General-purpose 32-bit and 64-bit bitfield encodings. 29 */ 30 #define BF32_DECODE(x, low, len) P2PHASE((x) >> (low), 1U << (len)) 31 #define BF64_DECODE(x, low, len) P2PHASE((x) >> (low), 1ULL << (len)) 32 #define BF32_ENCODE(x, low, len) (P2PHASE((x), 1U << (len)) << (low)) 33 #define BF64_ENCODE(x, low, len) (P2PHASE((x), 1ULL << (len)) << (low)) 34 35 #define BF32_GET(x, low, len) BF32_DECODE(x, low, len) 36 #define BF64_GET(x, low, len) BF64_DECODE(x, low, len) 37 38 #define BF32_SET(x, low, len, val) \ 39 ((x) ^= BF32_ENCODE((x >> low) ^ (val), low, len)) 40 #define BF64_SET(x, low, len, val) \ 41 ((x) ^= BF64_ENCODE((x >> low) ^ (val), low, len)) 42 43 #define BF32_GET_SB(x, low, len, shift, bias) \ 44 ((BF32_GET(x, low, len) + (bias)) << (shift)) 45 #define BF64_GET_SB(x, low, len, shift, bias) \ 46 ((BF64_GET(x, low, len) + (bias)) << (shift)) 47 48 #define BF32_SET_SB(x, low, len, shift, bias, val) \ 49 BF32_SET(x, low, len, ((val) >> (shift)) - (bias)) 50 #define BF64_SET_SB(x, low, len, shift, bias, val) \ 51 BF64_SET(x, low, len, ((val) >> (shift)) - (bias)) 52 53 /* 54 * We currently support nine block sizes, from 512 bytes to 128K. 55 * We could go higher, but the benefits are near-zero and the cost 56 * of COWing a giant block to modify one byte would become excessive. 57 */ 58 #define SPA_MINBLOCKSHIFT 9 59 #define SPA_MAXBLOCKSHIFT 17 60 #define SPA_MINBLOCKSIZE (1ULL << SPA_MINBLOCKSHIFT) 61 #define SPA_MAXBLOCKSIZE (1ULL << SPA_MAXBLOCKSHIFT) 62 63 #define SPA_BLOCKSIZES (SPA_MAXBLOCKSHIFT - SPA_MINBLOCKSHIFT + 1) 64 65 /* 66 * Size of block to hold the configuration data (a packed nvlist) 67 */ 68 #define SPA_CONFIG_BLOCKSIZE (1 << 14) 69 70 /* 71 * The DVA size encodings for LSIZE and PSIZE support blocks up to 32MB. 72 * The ASIZE encoding should be at least 64 times larger (6 more bits) 73 * to support up to 4-way RAID-Z mirror mode with worst-case gang block 74 * overhead, three DVAs per bp, plus one more bit in case we do anything 75 * else that expands the ASIZE. 76 */ 77 #define SPA_LSIZEBITS 16 /* LSIZE up to 32M (2^16 * 512) */ 78 #define SPA_PSIZEBITS 16 /* PSIZE up to 32M (2^16 * 512) */ 79 #define SPA_ASIZEBITS 24 /* ASIZE up to 64 times larger */ 80 81 /* 82 * All SPA data is represented by 128-bit data virtual addresses (DVAs). 83 * The members of the dva_t should be considered opaque outside the SPA. 84 */ 85 typedef struct dva { 86 uint64_t dva_word[2]; 87 } dva_t; 88 89 /* 90 * Each block has a 256-bit checksum -- strong enough for cryptographic hashes. 91 */ 92 typedef struct zio_cksum { 93 uint64_t zc_word[4]; 94 } zio_cksum_t; 95 96 /* 97 * Each block is described by its DVAs, time of birth, checksum, etc. 98 * The word-by-word, bit-by-bit layout of the blkptr is as follows: 99 * 100 * 64 56 48 40 32 24 16 8 0 101 * +-------+-------+-------+-------+-------+-------+-------+-------+ 102 * 0 | vdev1 | GRID | ASIZE | 103 * +-------+-------+-------+-------+-------+-------+-------+-------+ 104 * 1 |G| offset1 | 105 * +-------+-------+-------+-------+-------+-------+-------+-------+ 106 * 2 | vdev2 | GRID | ASIZE | 107 * +-------+-------+-------+-------+-------+-------+-------+-------+ 108 * 3 |G| offset2 | 109 * +-------+-------+-------+-------+-------+-------+-------+-------+ 110 * 4 | vdev3 | GRID | ASIZE | 111 * +-------+-------+-------+-------+-------+-------+-------+-------+ 112 * 5 |G| offset3 | 113 * +-------+-------+-------+-------+-------+-------+-------+-------+ 114 * 6 |BDX|lvl| type | cksum | comp | PSIZE | LSIZE | 115 * +-------+-------+-------+-------+-------+-------+-------+-------+ 116 * 7 | padding | 117 * +-------+-------+-------+-------+-------+-------+-------+-------+ 118 * 8 | padding | 119 * +-------+-------+-------+-------+-------+-------+-------+-------+ 120 * 9 | physical birth txg | 121 * +-------+-------+-------+-------+-------+-------+-------+-------+ 122 * a | logical birth txg | 123 * +-------+-------+-------+-------+-------+-------+-------+-------+ 124 * b | fill count | 125 * +-------+-------+-------+-------+-------+-------+-------+-------+ 126 * c | checksum[0] | 127 * +-------+-------+-------+-------+-------+-------+-------+-------+ 128 * d | checksum[1] | 129 * +-------+-------+-------+-------+-------+-------+-------+-------+ 130 * e | checksum[2] | 131 * +-------+-------+-------+-------+-------+-------+-------+-------+ 132 * f | checksum[3] | 133 * +-------+-------+-------+-------+-------+-------+-------+-------+ 134 * 135 * Legend: 136 * 137 * vdev virtual device ID 138 * offset offset into virtual device 139 * LSIZE logical size 140 * PSIZE physical size (after compression) 141 * ASIZE allocated size (including RAID-Z parity and gang block headers) 142 * GRID RAID-Z layout information (reserved for future use) 143 * cksum checksum function 144 * comp compression function 145 * G gang block indicator 146 * B byteorder (endianness) 147 * D dedup 148 * X unused 149 * lvl level of indirection 150 * type DMU object type 151 * phys birth txg of block allocation; zero if same as logical birth txg 152 * log. birth transaction group in which the block was logically born 153 * fill count number of non-zero blocks under this bp 154 * checksum[4] 256-bit checksum of the data this bp describes 155 */ 156 #define SPA_BLKPTRSHIFT 7 /* blkptr_t is 128 bytes */ 157 #define SPA_DVAS_PER_BP 3 /* Number of DVAs in a bp */ 158 159 typedef struct blkptr { 160 dva_t blk_dva[SPA_DVAS_PER_BP]; /* Data Virtual Addresses */ 161 uint64_t blk_prop; /* size, compression, type, etc */ 162 uint64_t blk_pad[2]; /* Extra space for the future */ 163 uint64_t blk_phys_birth; /* txg when block was allocated */ 164 uint64_t blk_birth; /* transaction group at birth */ 165 uint64_t blk_fill; /* fill count */ 166 zio_cksum_t blk_cksum; /* 256-bit checksum */ 167 } blkptr_t; 168 169 /* 170 * Macros to get and set fields in a bp or DVA. 171 */ 172 #define DVA_GET_ASIZE(dva) \ 173 BF64_GET_SB((dva)->dva_word[0], 0, 24, SPA_MINBLOCKSHIFT, 0) 174 #define DVA_SET_ASIZE(dva, x) \ 175 BF64_SET_SB((dva)->dva_word[0], 0, 24, SPA_MINBLOCKSHIFT, 0, x) 176 177 #define DVA_GET_GRID(dva) BF64_GET((dva)->dva_word[0], 24, 8) 178 #define DVA_SET_GRID(dva, x) BF64_SET((dva)->dva_word[0], 24, 8, x) 179 180 #define DVA_GET_VDEV(dva) BF64_GET((dva)->dva_word[0], 32, 32) 181 #define DVA_SET_VDEV(dva, x) BF64_SET((dva)->dva_word[0], 32, 32, x) 182 183 #define DVA_GET_GANG(dva) BF64_GET((dva)->dva_word[1], 63, 1) 184 #define DVA_SET_GANG(dva, x) BF64_SET((dva)->dva_word[1], 63, 1, x) 185 186 #define BP_GET_LSIZE(bp) \ 187 BF64_GET_SB((bp)->blk_prop, 0, 16, SPA_MINBLOCKSHIFT, 1) 188 #define BP_SET_LSIZE(bp, x) \ 189 BF64_SET_SB((bp)->blk_prop, 0, 16, SPA_MINBLOCKSHIFT, 1, x) 190 191 #define BP_GET_COMPRESS(bp) BF64_GET((bp)->blk_prop, 32, 8) 192 #define BP_SET_COMPRESS(bp, x) BF64_SET((bp)->blk_prop, 32, 8, x) 193 194 #define BP_GET_CHECKSUM(bp) BF64_GET((bp)->blk_prop, 40, 8) 195 #define BP_SET_CHECKSUM(bp, x) BF64_SET((bp)->blk_prop, 40, 8, x) 196 197 #define BP_GET_TYPE(bp) BF64_GET((bp)->blk_prop, 48, 8) 198 #define BP_SET_TYPE(bp, x) BF64_SET((bp)->blk_prop, 48, 8, x) 199 200 #define BP_GET_LEVEL(bp) BF64_GET((bp)->blk_prop, 56, 5) 201 #define BP_SET_LEVEL(bp, x) BF64_SET((bp)->blk_prop, 56, 5, x) 202 203 #define BP_GET_PROP_BIT_61(bp) BF64_GET((bp)->blk_prop, 61, 1) 204 #define BP_SET_PROP_BIT_61(bp, x) BF64_SET((bp)->blk_prop, 61, 1, x) 205 206 #define BP_GET_DEDUP(bp) BF64_GET((bp)->blk_prop, 62, 1) 207 #define BP_SET_DEDUP(bp, x) BF64_SET((bp)->blk_prop, 62, 1, x) 208 209 #define BP_GET_BYTEORDER(bp) (0 - BF64_GET((bp)->blk_prop, 63, 1)) 210 #define BP_SET_BYTEORDER(bp, x) BF64_SET((bp)->blk_prop, 63, 1, x) 211 212 #define BP_PHYSICAL_BIRTH(bp) \ 213 ((bp)->blk_phys_birth ? (bp)->blk_phys_birth : (bp)->blk_birth) 214 215 #define BP_SET_BIRTH(bp, logical, physical) \ 216 { \ 217 (bp)->blk_birth = (logical); \ 218 (bp)->blk_phys_birth = ((logical) == (physical) ? 0 : (physical)); \ 219 } 220 221 #define BP_GET_ASIZE(bp) \ 222 (DVA_GET_ASIZE(&(bp)->blk_dva[0]) + DVA_GET_ASIZE(&(bp)->blk_dva[1]) + \ 223 DVA_GET_ASIZE(&(bp)->blk_dva[2])) 224 225 #define BP_GET_UCSIZE(bp) \ 226 ((BP_GET_LEVEL(bp) > 0 || dmu_ot[BP_GET_TYPE(bp)].ot_metadata) ? \ 227 BP_GET_PSIZE(bp) : BP_GET_LSIZE(bp)); 228 229 #define BP_GET_NDVAS(bp) \ 230 (!!DVA_GET_ASIZE(&(bp)->blk_dva[0]) + \ 231 !!DVA_GET_ASIZE(&(bp)->blk_dva[1]) + \ 232 !!DVA_GET_ASIZE(&(bp)->blk_dva[2])) 233 234 #define BP_COUNT_GANG(bp) \ 235 (DVA_GET_GANG(&(bp)->blk_dva[0]) + \ 236 DVA_GET_GANG(&(bp)->blk_dva[1]) + \ 237 DVA_GET_GANG(&(bp)->blk_dva[2])) 238 239 #define DVA_EQUAL(dva1, dva2) \ 240 ((dva1)->dva_word[1] == (dva2)->dva_word[1] && \ 241 (dva1)->dva_word[0] == (dva2)->dva_word[0]) 242 243 #define BP_EQUAL(bp1, bp2) \ 244 (BP_PHYSICAL_BIRTH(bp1) == BP_PHYSICAL_BIRTH(bp2) && \ 245 DVA_EQUAL(&(bp1)->blk_dva[0], &(bp2)->blk_dva[0]) && \ 246 DVA_EQUAL(&(bp1)->blk_dva[1], &(bp2)->blk_dva[1]) && \ 247 DVA_EQUAL(&(bp1)->blk_dva[2], &(bp2)->blk_dva[2])) 248 249 #define ZIO_CHECKSUM_EQUAL(zc1, zc2) \ 250 (0 == (((zc1).zc_word[0] - (zc2).zc_word[0]) | \ 251 ((zc1).zc_word[1] - (zc2).zc_word[1]) | \ 252 ((zc1).zc_word[2] - (zc2).zc_word[2]) | \ 253 ((zc1).zc_word[3] - (zc2).zc_word[3]))) 254 255 #define DVA_IS_VALID(dva) (DVA_GET_ASIZE(dva) != 0) 256 257 #define ZIO_SET_CHECKSUM(zcp, w0, w1, w2, w3) \ 258 { \ 259 (zcp)->zc_word[0] = w0; \ 260 (zcp)->zc_word[1] = w1; \ 261 (zcp)->zc_word[2] = w2; \ 262 (zcp)->zc_word[3] = w3; \ 263 } 264 265 #define BP_IDENTITY(bp) (&(bp)->blk_dva[0]) 266 #define BP_IS_GANG(bp) DVA_GET_GANG(BP_IDENTITY(bp)) 267 #define BP_IS_HOLE(bp) ((bp)->blk_birth == 0) 268 269 /* BP_IS_RAIDZ(bp) assumes no block compression */ 270 #define BP_IS_RAIDZ(bp) (DVA_GET_ASIZE(&(bp)->blk_dva[0]) > \ 271 BP_GET_PSIZE(bp)) 272 273 #define BP_ZERO(bp) \ 274 { \ 275 (bp)->blk_dva[0].dva_word[0] = 0; \ 276 (bp)->blk_dva[0].dva_word[1] = 0; \ 277 (bp)->blk_dva[1].dva_word[0] = 0; \ 278 (bp)->blk_dva[1].dva_word[1] = 0; \ 279 (bp)->blk_dva[2].dva_word[0] = 0; \ 280 (bp)->blk_dva[2].dva_word[1] = 0; \ 281 (bp)->blk_prop = 0; \ 282 (bp)->blk_pad[0] = 0; \ 283 (bp)->blk_pad[1] = 0; \ 284 (bp)->blk_phys_birth = 0; \ 285 (bp)->blk_birth = 0; \ 286 (bp)->blk_fill = 0; \ 287 ZIO_SET_CHECKSUM(&(bp)->blk_cksum, 0, 0, 0, 0); \ 288 } 289 290 #define BP_SPRINTF_LEN 320 291 292 #endif /* ! ZFS_SPA_HEADER */ 293