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