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Diffstat (limited to 'include/zfs/spa.h')
| -rw-r--r-- | include/zfs/spa.h | 292 |
1 files changed, 292 insertions, 0 deletions
diff --git a/include/zfs/spa.h b/include/zfs/spa.h new file mode 100644 index 000000000..360cf897d --- /dev/null +++ b/include/zfs/spa.h @@ -0,0 +1,292 @@ +/* + * 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 (c) 2008, 2011, Oracle and/or its affiliates. All rights reserved. + */ + +#ifndef ZFS_SPA_HEADER +#define ZFS_SPA_HEADER 1 + + +/* + * General-purpose 32-bit and 64-bit bitfield encodings. + */ +#define BF32_DECODE(x, low, len) P2PHASE((x) >> (low), 1U << (len)) +#define BF64_DECODE(x, low, len) P2PHASE((x) >> (low), 1ULL << (len)) +#define BF32_ENCODE(x, low, len) (P2PHASE((x), 1U << (len)) << (low)) +#define BF64_ENCODE(x, low, len) (P2PHASE((x), 1ULL << (len)) << (low)) + +#define BF32_GET(x, low, len) BF32_DECODE(x, low, len) +#define BF64_GET(x, low, len) BF64_DECODE(x, low, len) + +#define BF32_SET(x, low, len, val) \ + ((x) ^= BF32_ENCODE((x >> low) ^ (val), low, len)) +#define BF64_SET(x, low, len, val) \ + ((x) ^= BF64_ENCODE((x >> low) ^ (val), low, len)) + +#define BF32_GET_SB(x, low, len, shift, bias) \ + ((BF32_GET(x, low, len) + (bias)) << (shift)) +#define BF64_GET_SB(x, low, len, shift, bias) \ + ((BF64_GET(x, low, len) + (bias)) << (shift)) + +#define BF32_SET_SB(x, low, len, shift, bias, val) \ + BF32_SET(x, low, len, ((val) >> (shift)) - (bias)) +#define BF64_SET_SB(x, low, len, shift, bias, val) \ + BF64_SET(x, low, len, ((val) >> (shift)) - (bias)) + +/* + * We currently support nine block sizes, from 512 bytes to 128K. + * We could go higher, but the benefits are near-zero and the cost + * of COWing a giant block to modify one byte would become excessive. + */ +#define SPA_MINBLOCKSHIFT 9 +#define SPA_MAXBLOCKSHIFT 17 +#define SPA_MINBLOCKSIZE (1ULL << SPA_MINBLOCKSHIFT) +#define SPA_MAXBLOCKSIZE (1ULL << SPA_MAXBLOCKSHIFT) + +#define SPA_BLOCKSIZES (SPA_MAXBLOCKSHIFT - SPA_MINBLOCKSHIFT + 1) + +/* + * Size of block to hold the configuration data (a packed nvlist) + */ +#define SPA_CONFIG_BLOCKSIZE (1 << 14) + +/* + * The DVA size encodings for LSIZE and PSIZE support blocks up to 32MB. + * The ASIZE encoding should be at least 64 times larger (6 more bits) + * to support up to 4-way RAID-Z mirror mode with worst-case gang block + * overhead, three DVAs per bp, plus one more bit in case we do anything + * else that expands the ASIZE. + */ +#define SPA_LSIZEBITS 16 /* LSIZE up to 32M (2^16 * 512) */ +#define SPA_PSIZEBITS 16 /* PSIZE up to 32M (2^16 * 512) */ +#define SPA_ASIZEBITS 24 /* ASIZE up to 64 times larger */ + +/* + * All SPA data is represented by 128-bit data virtual addresses (DVAs). + * The members of the dva_t should be considered opaque outside the SPA. + */ +typedef struct dva { + uint64_t dva_word[2]; +} dva_t; + +/* + * Each block has a 256-bit checksum -- strong enough for cryptographic hashes. + */ +typedef struct zio_cksum { + uint64_t zc_word[4]; +} zio_cksum_t; + +/* + * Each block is described by its DVAs, time of birth, checksum, etc. + * The word-by-word, bit-by-bit layout of the blkptr is as follows: + * + * 64 56 48 40 32 24 16 8 0 + * +-------+-------+-------+-------+-------+-------+-------+-------+ + * 0 | vdev1 | GRID | ASIZE | + * +-------+-------+-------+-------+-------+-------+-------+-------+ + * 1 |G| offset1 | + * +-------+-------+-------+-------+-------+-------+-------+-------+ + * 2 | vdev2 | GRID | ASIZE | + * +-------+-------+-------+-------+-------+-------+-------+-------+ + * 3 |G| offset2 | + * +-------+-------+-------+-------+-------+-------+-------+-------+ + * 4 | vdev3 | GRID | ASIZE | + * +-------+-------+-------+-------+-------+-------+-------+-------+ + * 5 |G| offset3 | + * +-------+-------+-------+-------+-------+-------+-------+-------+ + * 6 |BDX|lvl| type | cksum | comp | PSIZE | LSIZE | + * +-------+-------+-------+-------+-------+-------+-------+-------+ + * 7 | padding | + * +-------+-------+-------+-------+-------+-------+-------+-------+ + * 8 | padding | + * +-------+-------+-------+-------+-------+-------+-------+-------+ + * 9 | physical birth txg | + * +-------+-------+-------+-------+-------+-------+-------+-------+ + * a | logical birth txg | + * +-------+-------+-------+-------+-------+-------+-------+-------+ + * b | fill count | + * +-------+-------+-------+-------+-------+-------+-------+-------+ + * c | checksum[0] | + * +-------+-------+-------+-------+-------+-------+-------+-------+ + * d | checksum[1] | + * +-------+-------+-------+-------+-------+-------+-------+-------+ + * e | checksum[2] | + * +-------+-------+-------+-------+-------+-------+-------+-------+ + * f | checksum[3] | + * +-------+-------+-------+-------+-------+-------+-------+-------+ + * + * Legend: + * + * vdev virtual device ID + * offset offset into virtual device + * LSIZE logical size + * PSIZE physical size (after compression) + * ASIZE allocated size (including RAID-Z parity and gang block headers) + * GRID RAID-Z layout information (reserved for future use) + * cksum checksum function + * comp compression function + * G gang block indicator + * B byteorder (endianness) + * D dedup + * X unused + * lvl level of indirection + * type DMU object type + * phys birth txg of block allocation; zero if same as logical birth txg + * log. birth transaction group in which the block was logically born + * fill count number of non-zero blocks under this bp + * checksum[4] 256-bit checksum of the data this bp describes + */ +#define SPA_BLKPTRSHIFT 7 /* blkptr_t is 128 bytes */ +#define SPA_DVAS_PER_BP 3 /* Number of DVAs in a bp */ + +typedef struct blkptr { + dva_t blk_dva[SPA_DVAS_PER_BP]; /* Data Virtual Addresses */ + uint64_t blk_prop; /* size, compression, type, etc */ + uint64_t blk_pad[2]; /* Extra space for the future */ + uint64_t blk_phys_birth; /* txg when block was allocated */ + uint64_t blk_birth; /* transaction group at birth */ + uint64_t blk_fill; /* fill count */ + zio_cksum_t blk_cksum; /* 256-bit checksum */ +} blkptr_t; + +/* + * Macros to get and set fields in a bp or DVA. + */ +#define DVA_GET_ASIZE(dva) \ + BF64_GET_SB((dva)->dva_word[0], 0, 24, SPA_MINBLOCKSHIFT, 0) +#define DVA_SET_ASIZE(dva, x) \ + BF64_SET_SB((dva)->dva_word[0], 0, 24, SPA_MINBLOCKSHIFT, 0, x) + +#define DVA_GET_GRID(dva) BF64_GET((dva)->dva_word[0], 24, 8) +#define DVA_SET_GRID(dva, x) BF64_SET((dva)->dva_word[0], 24, 8, x) + +#define DVA_GET_VDEV(dva) BF64_GET((dva)->dva_word[0], 32, 32) +#define DVA_SET_VDEV(dva, x) BF64_SET((dva)->dva_word[0], 32, 32, x) + +#define DVA_GET_GANG(dva) BF64_GET((dva)->dva_word[1], 63, 1) +#define DVA_SET_GANG(dva, x) BF64_SET((dva)->dva_word[1], 63, 1, x) + +#define BP_GET_LSIZE(bp) \ + BF64_GET_SB((bp)->blk_prop, 0, 16, SPA_MINBLOCKSHIFT, 1) +#define BP_SET_LSIZE(bp, x) \ + BF64_SET_SB((bp)->blk_prop, 0, 16, SPA_MINBLOCKSHIFT, 1, x) + +#define BP_GET_COMPRESS(bp) BF64_GET((bp)->blk_prop, 32, 8) +#define BP_SET_COMPRESS(bp, x) BF64_SET((bp)->blk_prop, 32, 8, x) + +#define BP_GET_CHECKSUM(bp) BF64_GET((bp)->blk_prop, 40, 8) +#define BP_SET_CHECKSUM(bp, x) BF64_SET((bp)->blk_prop, 40, 8, x) + +#define BP_GET_TYPE(bp) BF64_GET((bp)->blk_prop, 48, 8) +#define BP_SET_TYPE(bp, x) BF64_SET((bp)->blk_prop, 48, 8, x) + +#define BP_GET_LEVEL(bp) BF64_GET((bp)->blk_prop, 56, 5) +#define BP_SET_LEVEL(bp, x) BF64_SET((bp)->blk_prop, 56, 5, x) + +#define BP_GET_PROP_BIT_61(bp) BF64_GET((bp)->blk_prop, 61, 1) +#define BP_SET_PROP_BIT_61(bp, x) BF64_SET((bp)->blk_prop, 61, 1, x) + +#define BP_GET_DEDUP(bp) BF64_GET((bp)->blk_prop, 62, 1) +#define BP_SET_DEDUP(bp, x) BF64_SET((bp)->blk_prop, 62, 1, x) + +#define BP_GET_BYTEORDER(bp) (0 - BF64_GET((bp)->blk_prop, 63, 1)) +#define BP_SET_BYTEORDER(bp, x) BF64_SET((bp)->blk_prop, 63, 1, x) + +#define BP_PHYSICAL_BIRTH(bp) \ + ((bp)->blk_phys_birth ? (bp)->blk_phys_birth : (bp)->blk_birth) + +#define BP_SET_BIRTH(bp, logical, physical) \ + { \ + (bp)->blk_birth = (logical); \ + (bp)->blk_phys_birth = ((logical) == (physical) ? 0 : (physical)); \ + } + +#define BP_GET_ASIZE(bp) \ + (DVA_GET_ASIZE(&(bp)->blk_dva[0]) + DVA_GET_ASIZE(&(bp)->blk_dva[1]) + \ + DVA_GET_ASIZE(&(bp)->blk_dva[2])) + +#define BP_GET_UCSIZE(bp) \ + ((BP_GET_LEVEL(bp) > 0 || dmu_ot[BP_GET_TYPE(bp)].ot_metadata) ? \ + BP_GET_PSIZE(bp) : BP_GET_LSIZE(bp)); + +#define BP_GET_NDVAS(bp) \ + (!!DVA_GET_ASIZE(&(bp)->blk_dva[0]) + \ + !!DVA_GET_ASIZE(&(bp)->blk_dva[1]) + \ + !!DVA_GET_ASIZE(&(bp)->blk_dva[2])) + +#define BP_COUNT_GANG(bp) \ + (DVA_GET_GANG(&(bp)->blk_dva[0]) + \ + DVA_GET_GANG(&(bp)->blk_dva[1]) + \ + DVA_GET_GANG(&(bp)->blk_dva[2])) + +#define DVA_EQUAL(dva1, dva2) \ + ((dva1)->dva_word[1] == (dva2)->dva_word[1] && \ + (dva1)->dva_word[0] == (dva2)->dva_word[0]) + +#define BP_EQUAL(bp1, bp2) \ + (BP_PHYSICAL_BIRTH(bp1) == BP_PHYSICAL_BIRTH(bp2) && \ + DVA_EQUAL(&(bp1)->blk_dva[0], &(bp2)->blk_dva[0]) && \ + DVA_EQUAL(&(bp1)->blk_dva[1], &(bp2)->blk_dva[1]) && \ + DVA_EQUAL(&(bp1)->blk_dva[2], &(bp2)->blk_dva[2])) + +#define ZIO_CHECKSUM_EQUAL(zc1, zc2) \ + (0 == (((zc1).zc_word[0] - (zc2).zc_word[0]) | \ + ((zc1).zc_word[1] - (zc2).zc_word[1]) | \ + ((zc1).zc_word[2] - (zc2).zc_word[2]) | \ + ((zc1).zc_word[3] - (zc2).zc_word[3]))) + +#define DVA_IS_VALID(dva) (DVA_GET_ASIZE(dva) != 0) + +#define ZIO_SET_CHECKSUM(zcp, w0, w1, w2, w3) \ + { \ + (zcp)->zc_word[0] = w0; \ + (zcp)->zc_word[1] = w1; \ + (zcp)->zc_word[2] = w2; \ + (zcp)->zc_word[3] = w3; \ + } + +#define BP_IDENTITY(bp) (&(bp)->blk_dva[0]) +#define BP_IS_GANG(bp) DVA_GET_GANG(BP_IDENTITY(bp)) +#define BP_IS_HOLE(bp) ((bp)->blk_birth == 0) + +/* BP_IS_RAIDZ(bp) assumes no block compression */ +#define BP_IS_RAIDZ(bp) (DVA_GET_ASIZE(&(bp)->blk_dva[0]) > \ + BP_GET_PSIZE(bp)) + +#define BP_ZERO(bp) \ + { \ + (bp)->blk_dva[0].dva_word[0] = 0; \ + (bp)->blk_dva[0].dva_word[1] = 0; \ + (bp)->blk_dva[1].dva_word[0] = 0; \ + (bp)->blk_dva[1].dva_word[1] = 0; \ + (bp)->blk_dva[2].dva_word[0] = 0; \ + (bp)->blk_dva[2].dva_word[1] = 0; \ + (bp)->blk_prop = 0; \ + (bp)->blk_pad[0] = 0; \ + (bp)->blk_pad[1] = 0; \ + (bp)->blk_phys_birth = 0; \ + (bp)->blk_birth = 0; \ + (bp)->blk_fill = 0; \ + ZIO_SET_CHECKSUM(&(bp)->blk_cksum, 0, 0, 0, 0); \ + } + +#define BP_SPRINTF_LEN 320 + +#endif /* ! ZFS_SPA_HEADER */ |