[Ocfs2-tools-devel] [PATCH 07/12] libocfs2: Add blockcheck.[ch]
Joel Becker
Joel.Becker at oracle.com
Wed Jan 7 14:25:08 PST 2009
On Wed, Jan 07, 2009 at 02:13:21PM -0800, Sunil Mushran wrote:
> I am trusting you on the math. :)
Let's just say that it is tested, and the kernel and userspace
work together :-)
Joel
> Signed-off-by: Sunil Mushran <sunil.mushran at oracle.com>
>
> Joel Becker wrote:
>> blockcheck.c contains the crc32_le() function from the kernel and the
>> ocfs2_hamming_encode/fix() functions for computing the error correction
>> codes. These will be used to implement metadata checksums and error
>> correction in the tools ("metaecc").
>>
>> Signed-off-by: Joel Becker <joel.becker at oracle.com>
>> ---
>> include/ocfs2/ocfs2.h | 20 +
>> libocfs2/Makefile | 3 +
>> libocfs2/blockcheck.c | 976 +++++++++++++++++++++++++++++++++++++++++++++++++
>> libocfs2/blockcheck.h | 31 ++
>> libocfs2/crc32table.h | 150 ++++++++
>> 5 files changed, 1180 insertions(+), 0 deletions(-)
>> create mode 100644 libocfs2/blockcheck.c
>> create mode 100644 libocfs2/blockcheck.h
>> create mode 100644 libocfs2/crc32table.h
>>
>> diff --git a/include/ocfs2/ocfs2.h b/include/ocfs2/ocfs2.h
>> index 4b8444f..e515205 100644
>> --- a/include/ocfs2/ocfs2.h
>> +++ b/include/ocfs2/ocfs2.h
>> @@ -593,6 +593,17 @@ errcode_t ocfs2_write_slot_map_extended(ocfs2_filesys *fs,
>> int num_slots,
>> struct ocfs2_slot_map_extended *se);
>> +/* High level functions for metadata ecc */
>> +void ocfs2_compute_meta_ecc(ocfs2_filesys *fs, void *data,
>> + struct ocfs2_block_check *bc);
>> +errcode_t ocfs2_validate_meta_ecc(ocfs2_filesys *fs, void *data,
>> + struct ocfs2_block_check *bc);
>> +/* Low level checksum compute functions. Use the high-level ones. */
>> +extern void ocfs2_block_check_compute(void *data, size_t blocksize,
>> + struct ocfs2_block_check *bc);
>> +extern errcode_t ocfs2_block_check_validate(void *data, size_t blocksize,
>> + struct ocfs2_block_check *bc);
>> +
>> /* High level */
>> errcode_t ocfs2_format_slot_map(ocfs2_filesys *fs);
>> errcode_t ocfs2_load_slot_map(ocfs2_filesys *fs,
>> @@ -945,6 +956,15 @@ static inline int ocfs2_support_inline_data(struct ocfs2_super_block *osb)
>> return 0;
>> }
>> +static inline int ocfs2_meta_ecc(struct ocfs2_super_block *osb)
>> +{
>> + if (OCFS2_HAS_INCOMPAT_FEATURE(osb,
>> + OCFS2_FEATURE_INCOMPAT_META_ECC))
>> + return 1;
>> + return 0;
>> +}
>> +
>> +
>> /*
>> * shamelessly lifted from the kernel
>> *
>> diff --git a/libocfs2/Makefile b/libocfs2/Makefile
>> index 446c8b4..3add6b4 100644
>> --- a/libocfs2/Makefile
>> +++ b/libocfs2/Makefile
>> @@ -36,6 +36,7 @@ CFILES = \
>> alloc.c \
>> bitmap.c \
>> bitops.c \
>> + blockcheck.c \
>> cached_inode.c \
>> chain.c \
>> chainalloc.c \
>> @@ -76,6 +77,8 @@ CFILES = \
>> HFILES = \
>> bitmap.h \
>> + blockcheck.h \
>> + crc32table.h \
>> dir_iterate.h \
>> dir_util.h \
>> dlm.h \
>> diff --git a/libocfs2/blockcheck.c b/libocfs2/blockcheck.c
>> new file mode 100644
>> index 0000000..f76051e
>> --- /dev/null
>> +++ b/libocfs2/blockcheck.c
>> @@ -0,0 +1,976 @@
>> +/* -*- mode: c; c-basic-offset: 8; -*-
>> + * vim: noexpandtab sw=8 ts=8 sts=0:
>> + *
>> + * blockcheck.c
>> + *
>> + * Checksum and ECC codes for the OCFS2 userspace library.
>> + *
>> + * Copyright (C) 2006, 2008 Oracle. All rights reserved.
>> + *
>> + * This program is free software; you can redistribute it and/or
>> + * modify it under the terms of the GNU General Public
>> + * License, version 2, as published by the Free Software Foundation.
>> + *
>> + * 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.
>> + *
>> + * The 802.3 CRC32 algorithm is copied from the Linux kernel, lib/crc32.c.
>> + * Code was from the public domain, is now GPL, so no real copyright
>> + * attribution other than "The Linux Kernel". XXX: better text, anyone?
>> + */
>> +
>> +#define _XOPEN_SOURCE 600 /* Triggers magic in features.h */
>> +#define _LARGEFILE64_SOURCE
>> +
>> +#ifdef DEBUG_EXE
>> +# define _BSD_SOURCE /* For timersub() */
>> +#endif
>> +
>> +#include <inttypes.h>
>> +
>> +#include "ocfs2/ocfs2.h"
>> +#include "ocfs2/bitops.h"
>> +#include "ocfs2/byteorder.h"
>> +
>> +#include "blockcheck.h"
>> +#include "crc32table.h"
>> +
>> +
>> +static inline unsigned int hc_hweight32(unsigned int w)
>> +{
>> + unsigned int res = (w & 0x55555555) + ((w >> 1) & 0x55555555);
>> + res = (res & 0x33333333) + ((res >> 2) & 0x33333333);
>> + res = (res & 0x0F0F0F0F) + ((res >> 4) & 0x0F0F0F0F);
>> + res = (res & 0x00FF00FF) + ((res >> 8) & 0x00FF00FF);
>> + return (res & 0x0000FFFF) + ((res >> 16) & 0x0000FFFF);
>> +}
>> +
>> +/*
>> + * Calculate the bit offset in the hamming code buffer based on the bit's
>> + * offset in the data buffer. Since the hamming code reserves all
>> + * power-of-two bits for parity, the data bit number and the code bit
>> + * number are offest by all the parity bits beforehand.
>> + *
>> + * Recall that bit numbers in hamming code are 1-based. This function
>> + * takes the 0-based data bit from the caller.
>> + *
>> + * An example. Take bit 1 of the data buffer. 1 is a power of two (2^0),
>> + * so it's a parity bit. 2 is a power of two (2^1), so it's a parity bit.
>> + * 3 is not a power of two. So bit 1 of the data buffer ends up as bit 3
>> + * in the code buffer.
>> + *
>> + * The caller passes in *p if it wants to keep track of the most recent
>> + * number of parity bits added. This allows the function to start the
>> + * calculation at the last place.
>> + */
>> +static unsigned int calc_code_bit(unsigned int i, unsigned int *p_cache)
>> +{
>> + unsigned int b, p = 0;
>> +
>> + /*
>> + * Data bits are 0-based, but we're talking code bits, which
>> + * are 1-based.
>> + */
>> + b = i + 1;
>> +
>> + /* Use the cache if it is there */
>> + if (p_cache)
>> + p = *p_cache;
>> + b += p;
>> +
>> + /*
>> + * For every power of two below our bit number, bump our bit.
>> + *
>> + * We compare with (b + 1) because we have to compare with what b
>> + * would be _if_ it were bumped up by the parity bit. Capice?
>> + *
>> + * p is set above.
>> + */
>> + for (; (1 << p) < (b + 1); p++)
>> + b++;
>> +
>> + if (p_cache)
>> + *p_cache = p;
>> +
>> + return b;
>> +}
>> +
>> +/*
>> + * This is the low level encoder function. It can be called across
>> + * multiple hunks just like the crc32 code. 'd' is the number of bits
>> + * _in_this_hunk_. nr is the bit offset of this hunk. So, if you had
>> + * two 512B buffers, you would do it like so:
>> + *
>> + * parity = ocfs2_hamming_encode(0, buf1, 512 * 8, 0);
>> + * parity = ocfs2_hamming_encode(parity, buf2, 512 * 8, 512 * 8);
>> + *
>> + * If you just have one buffer, use ocfs2_hamming_encode_block().
>> + */
>> +uint32_t ocfs2_hamming_encode(uint32_t parity, void *data, unsigned int d,
>> + unsigned int nr)
>> +{
>> + unsigned int i, b, p = 0;
>> +
>> + if (!d)
>> + abort();
>> +
>> + /*
>> + * b is the hamming code bit number. Hamming code specifies a
>> + * 1-based array, but C uses 0-based. So 'i' is for C, and 'b' is
>> + * for the algorithm.
>> + *
>> + * The i++ in the for loop is so that the start offset passed
>> + * to ocfs2_find_next_bit_set() is one greater than the previously
>> + * found bit.
>> + */
>> + for (i = 0; (i = ocfs2_find_next_bit_set(data, d, i)) < d; i++)
>> + {
>> + /*
>> + * i is the offset in this hunk, nr + i is the total bit
>> + * offset.
>> + */
>> + b = calc_code_bit(nr + i, &p);
>> +
>> + /*
>> + * Data bits in the resultant code are checked by
>> + * parity bits that are part of the bit number
>> + * representation. Huh?
>> + *
>> + * <wikipedia href="http://en.wikipedia.org/wiki/Hamming_code">
>> + * In other words, the parity bit at position 2^k
>> + * checks bits in positions having bit k set in
>> + * their binary representation. Conversely, for
>> + * instance, bit 13, i.e. 1101(2), is checked by
>> + * bits 1000(2) = 8, 0100(2)=4 and 0001(2) = 1.
>> + * </wikipedia>
>> + *
>> + * Note that 'k' is the _code_ bit number. 'b' in
>> + * our loop.
>> + */
>> + parity ^= b;
>> + }
>> +
>> + /* While the data buffer was treated as little endian, the
>> + * return value is in host endian. */
>> + return parity;
>> +}
>> +
>> +uint32_t ocfs2_hamming_encode_block(void *data, unsigned int blocksize)
>> +{
>> + return ocfs2_hamming_encode(0, data, blocksize * 8, 0);
>> +}
>> +
>> +/*
>> + * Like ocfs2_hamming_encode(), this can handle hunks. nr is the bit
>> + * offset of the current hunk. If bit to be fixed is not part of the
>> + * current hunk, this does nothing.
>> + *
>> + * If you only have one hunk, use ocfs2_hamming_fix_block().
>> + */
>> +void ocfs2_hamming_fix(void *data, unsigned int d, unsigned int nr,
>> + unsigned int fix)
>> +{
>> + unsigned int i, b;
>> +
>> + if (!d)
>> + abort();
>> +
>> + /*
>> + * If the bit to fix has an hweight of 1, it's a parity bit. One
>> + * busted parity bit is its own error. Nothing to do here.
>> + */
>> + if (hc_hweight32(fix) == 1)
>> + return;
>> +
>> + /*
>> + * nr + d is the bit right past the data hunk we're looking at.
>> + * If fix after that, nothing to do
>> + */
>> + if (fix >= calc_code_bit(nr + d, NULL))
>> + return;
>> +
>> + /*
>> + * nr is the offset in the data hunk we're starting at. Let's
>> + * start b at the offset in the code buffer. See hamming_encode()
>> + * for a more detailed description of 'b'.
>> + */
>> + b = calc_code_bit(nr, NULL);
>> + /* If the fix is before this hunk, nothing to do */
>> + if (fix < b)
>> + return;
>> +
>> + for (i = 0; i < d; i++, b++)
>> + {
>> + /* Skip past parity bits */
>> + while (hc_hweight32(b) == 1)
>> + b++;
>> +
>> + /*
>> + * i is the offset in this data hunk.
>> + * nr + i is the offset in the total data buffer.
>> + * b is the offset in the total code buffer.
>> + *
>> + * Thus, when b == fix, bit i in the current hunk needs
>> + * fixing.
>> + */
>> + if (b == fix)
>> + {
>> + if (ocfs2_test_bit(i, data))
>> + ocfs2_clear_bit(i, data);
>> + else
>> + ocfs2_set_bit(i, data);
>> + break;
>> + }
>> + }
>> +}
>> +
>> +void ocfs2_hamming_fix_block(void *data, unsigned int blocksize,
>> + unsigned int fix)
>> +{
>> + ocfs2_hamming_fix(data, blocksize * 8, 0, fix);
>> +}
>> +
>> +/*
>> + * table-based crc32_le() stolen from the kernel. This is the one we know
>> + * the filesystem is using.
>> + *
>> + * RFC 3385 shows that the 802.3 crc32 (this one) has the same properties
>> + * and probabilities as crc32c (which iSCSI uses) for data blocks < 2^16
>> + * bits. We fit.
>> + */
>> +
>> +/**
>> + * crc32_le() - Calculate bitwise little-endian Ethernet AUTODIN II CRC32
>> + * @crc - seed value for computation. ~0 for Ethernet, sometimes 0 for
>> + * other uses, or the previous crc32 value if computing incrementally.
>> + * @p - pointer to buffer over which CRC is run
>> + * @len - length of buffer @p
>> + *
>> + */
>> +uint32_t crc32_le(uint32_t crc, unsigned char const *p, size_t len)
>> +{
>> + const uint32_t *b =(uint32_t *)p;
>> + const uint32_t *tab = crc32table_le;
>> +
>> +#if __BYTE_ORDER == __LITTLE_ENDIAN
>> +# define DO_CRC(x) crc = tab[ (crc ^ (x)) & 255 ] ^ (crc>>8)
>> +#else
>> +# define DO_CRC(x) crc = tab[ ((crc >> 24) ^ (x)) & 255] ^ (crc<<8)
>> +#endif
>> +
>> + crc = cpu_to_le32(crc);
>> + /* Align it */
>> + if(((long)b)&3 && len){
>> + do {
>> + uint8_t *p = (uint8_t *)b;
>> + DO_CRC(*p++);
>> + b = (void *)p;
>> + } while ((--len) && ((long)b)&3 );
>> + }
>> + if(len >= 4){
>> + /* load data 32 bits wide, xor data 32 bits wide. */
>> + size_t save_len = len & 3;
>> + len = len >> 2;
>> + --b; /* use pre increment below(*++b) for speed */
>> + do {
>> + crc ^= *++b;
>> + DO_CRC(0);
>> + DO_CRC(0);
>> + DO_CRC(0);
>> + DO_CRC(0);
>> + } while (--len);
>> + b++; /* point to next byte(s) */
>> + len = save_len;
>> + }
>> + /* And the last few bytes */
>> + if(len){
>> + do {
>> + uint8_t *p = (uint8_t *)b;
>> + DO_CRC(*p++);
>> + b = (void *)p;
>> + } while (--len);
>> + }
>> +
>> + return le32_to_cpu(crc);
>> +#undef DO_CRC
>> +}
>> +
>> +/*
>> + * This function generates check information for a block.
>> + * data is the block to be checked. bc is a pointer to the
>> + * ocfs2_block_check structure describing the crc32 and the ecc.
>> + *
>> + * bc should be a pointer inside data, as the function will
>> + * take care of zeroing it before calculating the check information. If
>> + * bc does not point inside data, the caller must make sure any inline
>> + * ocfs2_block_check structures are zeroed.
>> + *
>> + * The data buffer must be in on-disk endian (little endian for ocfs2).
>> + * bc will be filled with little-endian values and will be ready to go to
>> + * disk.
>> + */
>> +void ocfs2_block_check_compute(void *data, size_t blocksize,
>> + struct ocfs2_block_check *bc)
>> +{
>> + uint32_t crc;
>> + uint16_t ecc;
>> +
>> + memset(bc, 0, sizeof(struct ocfs2_block_check));
>> +
>> + crc = crc32_le(~0, data, blocksize);
>> + /* We know this will return max 16 bits */
>> + ecc = (uint16_t)ocfs2_hamming_encode_block(data, blocksize);
>> +
>> + bc->bc_crc32e = cpu_to_le32(crc);
>> + bc->bc_ecc = cpu_to_le16(ecc); /* We know it's max 16 bits */
>> +}
>> +
>> +/*
>> + * This function validates existing check information. Like _compute,
>> + * the function will take care of zeroing bc before calculating check codes.
>> + * If bc is not a pointer inside data, the caller must have zeroed any
>> + * inline ocfs2_block_check structures.
>> + *
>> + * Again, the data passed in should be the on-disk endian.
>> + */
>> +errcode_t ocfs2_block_check_validate(void *data, size_t blocksize,
>> + struct ocfs2_block_check *bc)
>> +{
>> + errcode_t err = 0;
>> + struct ocfs2_block_check check;
>> + uint32_t crc, ecc;
>> +
>> + check.bc_crc32e = le32_to_cpu(bc->bc_crc32e);
>> + check.bc_ecc = le16_to_cpu(bc->bc_ecc);
>> +
>> + memset(bc, 0, sizeof(struct ocfs2_block_check));
>> +
>> + /* Fast path - if the crc32 validates, we're good to go */
>> + crc = crc32_le(~0, data, blocksize);
>> + if (crc == check.bc_crc32e)
>> + goto out;
>> +
>> + /* Ok, try ECC fixups */
>> + ecc = ocfs2_hamming_encode_block(data, blocksize);
>> + ocfs2_hamming_fix_block(data, blocksize, ecc ^ check.bc_ecc);
>> +
>> + /* And check the crc32 again */
>> + crc = crc32_le(~0, data, blocksize);
>> + if (crc == check.bc_crc32e)
>> + goto out;
>> +
>> + err = OCFS2_ET_IO;
>> +
>> +out:
>> + bc->bc_crc32e = cpu_to_le32(check.bc_crc32e);
>> + bc->bc_ecc = cpu_to_le16(check.bc_ecc);
>> +
>> + return err;
>> +}
>> +
>> +/*
>> + * These are the main API. They check the superblock flag before
>> + * calling the underlying operations.
>> + *
>> + * They expect the buffer to be in disk format.
>> + */
>> +void ocfs2_compute_meta_ecc(ocfs2_filesys *fs, void *data,
>> + struct ocfs2_block_check *bc)
>> +{
>> + if (ocfs2_meta_ecc(OCFS2_RAW_SB(fs->fs_super)))
>> + ocfs2_block_check_compute(data, fs->fs_blocksize, bc);
>> +}
>> +
>> +errcode_t ocfs2_validate_meta_ecc(ocfs2_filesys *fs, void *data,
>> + struct ocfs2_block_check *bc)
>> +{
>> + errcode_t err = 0;
>> +
>> + if (ocfs2_meta_ecc(OCFS2_RAW_SB(fs->fs_super)))
>> + err = ocfs2_block_check_validate(data, fs->fs_blocksize, bc);
>> +
>> + return err;
>> +}
>> +
>> +#ifdef DEBUG_EXE
>> +#include <stdio.h>
>> +#include <string.h>
>> +#include <stdlib.h>
>> +#include <sys/types.h>
>> +#include <sys/stat.h>
>> +#include <unistd.h>
>> +#include <fcntl.h>
>> +#include <sys/time.h>
>> +#include <sys/resource.h>
>> +#include <assert.h>
>> +#include <errno.h>
>> +
>> +/*
>> + * The function hamming_encode_orig() is my original, tested version. It's
>> + * slow. We work from it to make a faster one.
>> + */
>> +
>> +/*
>> + * We use the following conventions:
>> + *
>> + * d = # data bits
>> + * p = # parity bits
>> + * c = # total code bits (d + p)
>> + */
>> +static int calc_parity_bits_orig(unsigned int d)
>> +{
>> + unsigned int p;
>> +
>> + /*
>> + * Bits required for Single Error Correction is as follows:
>> + *
>> + * d + p + 1 <= 2^p
>> + *
>> + * We're restricting ourselves to 31 bits of parity, that should be
>> + * sufficient.
>> + */
>> + for (p = 1; p < 32; p++)
>> + {
>> + if ((d + p + 1) <= (1 << p))
>> + return p;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static unsigned int calc_code_bit_orig(unsigned int i)
>> +{
>> + unsigned int b, p;
>> +
>> + /*
>> + * Data bits are 0-based, but we're talking code bits, which
>> + * are 1-based.
>> + */
>> + b = i + 1;
>> +
>> + /*
>> + * For every power of two below our bit number, bump our bit.
>> + *
>> + * We compare with (b + 1) because we have to compare with what b
>> + * would be _if_ it were bumped up by the parity bit. Capice?
>> + */
>> + for (p = 0; (1 << p) < (b + 1); p++)
>> + b++;
>> +
>> + return b;
>> +}
>> +
>> +/*
>> + * Find the log base 2 of 32-bit v.
>> + *
>> + * Algorithm found on http://graphics.stanford.edu/~seander/bithacks.html,
>> + * by Sean Eron Anderson. Code on the page is in the public domain unless
>> + * otherwise noted.
>> + *
>> + * This particular algorithm is credited to Eric Cole.
>> + */
>> +static int find_highest_bit_set(unsigned int v)
>> +{
>> +
>> + static const int MultiplyDeBruijnBitPosition[32] =
>> + {
>> + 0, 1, 28, 2, 29, 14, 24, 3, 30, 22, 20, 15, 25, 17, 4, 8,
>> + 31, 27, 13, 23, 21, 19, 16, 7, 26, 12, 18, 6, 11, 5, 10, 9
>> + };
>> +
>> + v |= v >> 1; /* first round down to power of 2 */
>> + v |= v >> 2;
>> + v |= v >> 4;
>> + v |= v >> 8;
>> + v |= v >> 16;
>> + v = (v >> 1) + 1;
>> +
>> + return MultiplyDeBruijnBitPosition[(uint32_t)(v * 0x077CB531UL) >> 27];
>> +}
>> +
>> +static unsigned int calc_code_bit_cheat(unsigned int i)
>> +{
>> + unsigned int b, p;
>> +
>> + /*
>> + * Data bits are 0-based, but we're talking code bits, which
>> + * are 1-based.
>> + */
>> + b = i + 1;
>> +
>> + /*
>> + * As a cheat, we know that all bits below b's highest bit must be
>> + * parity bits, so we can start there.
>> + */
>> + p = find_highest_bit_set(b);
>> + b += p;
>> +
>> + /*
>> + * For every power of two below our bit number, bump our bit.
>> + *
>> + * We compare with (b + 1) because we have to compare with what b
>> + * would be _if_ it were bumped up by the parity bit. Capice?
>> + *
>> + * We start p at 2^p because of the cheat above.
>> + */
>> + for (p = (1 << p); p < (b + 1); p <<= 1)
>> + b++;
>> +
>> + return b;
>> +}
>> +
>> +
>> +/*
>> + * This is the low level encoder function. It can be called across
>> + * multiple hunks just like the crc32 code. 'd' is the number of bits
>> + * _in_this_hunk_. nr is the bit offset of this hunk. So, if you had
>> + * two 512B buffers, you would do it like so:
>> + *
>> + * parity = ocfs2_hamming_encode(0, buf1, 512 * 8, 0);
>> + * parity = ocfs2_hamming_encode(parity, buf2, 512 * 8, 512 * 8);
>> + *
>> + * If you just have one buffer, use ocfs2_hamming_encode_block().
>> + */
>> +static uint32_t hamming_encode_orig(uint32_t parity, void *data, unsigned int d,
>> + unsigned int nr)
>> +{
>> + unsigned int p = calc_parity_bits_orig(d);
>> + unsigned int i, j, b;
>> +
>> + if (!p)
>> + abort();
>> +
>> + /*
>> + * b is the hamming code bit number. Hamming code specifies a
>> + * 1-based array, but C uses 0-based. So 'i' is for C, and 'b' is
>> + * for the algorithm.
>> + *
>> + * The i++ in the for loop is so that the start offset passed
>> + * to ocfs2_find_next_bit_set() is one greater than the previously
>> + * found bit.
>> + */
>> + for (i = 0; (i = ocfs2_find_next_bit_set(data, d, i)) < d; i++)
>> + {
>> + /*
>> + * i is the offset in this hunk, nr + i is the total bit
>> + * offset.
>> + */
>> + b = calc_code_bit_orig(nr + i);
>> +
>> + for (j = 0; j < p; j++)
>> + {
>> + /*
>> + * Data bits in the resultant code are checked by
>> + * parity bits that are part of the bit number
>> + * representation. Huh?
>> + *
>> + * <wikipedia href="http://en.wikipedia.org/wiki/Hamming_code">
>> + * In other words, the parity bit at position 2^k
>> + * checks bits in positions having bit k set in
>> + * their binary representation. Conversely, for
>> + * instance, bit 13, i.e. 1101(2), is checked by
>> + * bits 1000(2) = 8, 0100(2)=4 and 0001(2) = 1.
>> + * </wikipedia>
>> + *
>> + * Note that 'k' is the _code_ bit number. 'b' in
>> + * our loop.
>> + */
>> + if (b & (1 << j))
>> + parity ^= (1 << j);
>> + }
>> + }
>> +
>> + /* While the data buffer was treated as little endian, the
>> + * return value is in host endian. */
>> + return parity;
>> +}
>> +
>> +/*
>> + * This version uses the direct parity ^= b, but the original
>> + * calc_parity_bits() and calc_code_bit().
>> + */
>> +static uint32_t ocfs2_hamming_encode_orig_bits(uint32_t parity, void *data,
>> + unsigned int d, unsigned int nr)
>> +{
>> + unsigned int p = calc_parity_bits_orig(d);
>> + unsigned int i, b;
>> +
>> + if (!p)
>> + abort();
>> +
>> + /*
>> + * b is the hamming code bit number. Hamming code specifies a
>> + * 1-based array, but C uses 0-based. So 'i' is for C, and 'b' is
>> + * for the algorithm.
>> + *
>> + * The i++ in the for loop is so that the start offset passed
>> + * to ocfs2_find_next_bit_set() is one greater than the previously
>> + * found bit.
>> + */
>> + for (i = 0; (i = ocfs2_find_next_bit_set(data, d, i)) < d; i++)
>> + {
>> + /*
>> + * i is the offset in this hunk, nr + i is the total bit
>> + * offset.
>> + */
>> + b = calc_code_bit_orig(nr + i);
>> +
>> + /*
>> + * Data bits in the resultant code are checked by
>> + * parity bits that are part of the bit number
>> + * representation. Huh?
>> + *
>> + * <wikipedia href="http://en.wikipedia.org/wiki/Hamming_code">
>> + * In other words, the parity bit at position 2^k
>> + * checks bits in positions having bit k set in
>> + * their binary representation. Conversely, for
>> + * instance, bit 13, i.e. 1101(2), is checked by
>> + * bits 1000(2) = 8, 0100(2)=4 and 0001(2) = 1.
>> + * </wikipedia>
>> + *
>> + * Note that 'k' is the _code_ bit number. 'b' in
>> + * our loop.
>> + */
>> + parity ^= b;
>> + }
>> +
>> + /* While the data buffer was treated as little endian, the
>> + * return value is in host endian. */
>> + return parity;
>> +}
>> +
>> +/*
>> + * This version uses the direct parity ^= b, but the original
>> + * calc_code_bit()
>> + */
>> +static uint32_t ocfs2_hamming_encode_orig_code_bit(uint32_t parity, void *data,
>> + unsigned int d, unsigned int nr)
>> +{
>> + unsigned int i, b;
>> +
>> + if (!d)
>> + abort();
>> +
>> + /*
>> + * b is the hamming code bit number. Hamming code specifies a
>> + * 1-based array, but C uses 0-based. So 'i' is for C, and 'b' is
>> + * for the algorithm.
>> + *
>> + * The i++ in the for loop is so that the start offset passed
>> + * to ocfs2_find_next_bit_set() is one greater than the previously
>> + * found bit.
>> + */
>> + for (i = 0; (i = ocfs2_find_next_bit_set(data, d, i)) < d; i++)
>> + {
>> + /*
>> + * i is the offset in this hunk, nr + i is the total bit
>> + * offset.
>> + */
>> + b = calc_code_bit_orig(nr + i);
>> +
>> + /*
>> + * Data bits in the resultant code are checked by
>> + * parity bits that are part of the bit number
>> + * representation. Huh?
>> + *
>> + * <wikipedia href="http://en.wikipedia.org/wiki/Hamming_code">
>> + * In other words, the parity bit at position 2^k
>> + * checks bits in positions having bit k set in
>> + * their binary representation. Conversely, for
>> + * instance, bit 13, i.e. 1101(2), is checked by
>> + * bits 1000(2) = 8, 0100(2)=4 and 0001(2) = 1.
>> + * </wikipedia>
>> + *
>> + * Note that 'k' is the _code_ bit number. 'b' in
>> + * our loop.
>> + */
>> + parity ^= b;
>> + }
>> +
>> + /* While the data buffer was treated as little endian, the
>> + * return value is in host endian. */
>> + return parity;
>> +}
>> +
>> +/*
>> + * This version uses the direct parity ^= b, but the cheating
>> + * calc_code_bit().
>> + */
>> +static uint32_t ocfs2_hamming_encode_cheat_code_bit(uint32_t parity, void *data,
>> + unsigned int d, unsigned int nr)
>> +{
>> + unsigned int i, b;
>> +
>> + if (!d)
>> + abort();
>> +
>> + /*
>> + * b is the hamming code bit number. Hamming code specifies a
>> + * 1-based array, but C uses 0-based. So 'i' is for C, and 'b' is
>> + * for the algorithm.
>> + *
>> + * The i++ in the for loop is so that the start offset passed
>> + * to ocfs2_find_next_bit_set() is one greater than the previously
>> + * found bit.
>> + */
>> + for (i = 0; (i = ocfs2_find_next_bit_set(data, d, i)) < d; i++)
>> + {
>> + /*
>> + * i is the offset in this hunk, nr + i is the total bit
>> + * offset.
>> + */
>> + b = calc_code_bit_cheat(nr + i);
>> +
>> + /*
>> + * Data bits in the resultant code are checked by
>> + * parity bits that are part of the bit number
>> + * representation. Huh?
>> + *
>> + * <wikipedia href="http://en.wikipedia.org/wiki/Hamming_code">
>> + * In other words, the parity bit at position 2^k
>> + * checks bits in positions having bit k set in
>> + * their binary representation. Conversely, for
>> + * instance, bit 13, i.e. 1101(2), is checked by
>> + * bits 1000(2) = 8, 0100(2)=4 and 0001(2) = 1.
>> + * </wikipedia>
>> + *
>> + * Note that 'k' is the _code_ bit number. 'b' in
>> + * our loop.
>> + */
>> + parity ^= b;
>> + }
>> +
>> + /* While the data buffer was treated as little endian, the
>> + * return value is in host endian. */
>> + return parity;
>> +}
>> +
>> +
>> +struct run_context {
>> + char *rc_name;
>> + void *rc_data;
>> + int rc_size;
>> + int rc_count;
>> + void (*rc_func)(struct run_context *ct, int nr);
>> +};
>> +
>> +static void timeme(struct run_context *ct)
>> +{
>> + int i;
>> + struct rusage start;
>> + struct rusage stop;
>> + struct timeval sys_diff, usr_diff;
>> +
>> + assert(!getrusage(RUSAGE_SELF, &start));
>> +
>> + for (i = 0; i < ct->rc_count; i++)
>> + ct->rc_func(ct, i);
>> +
>> + assert(!getrusage(RUSAGE_SELF, &stop));
>> + timersub(&stop.ru_utime, &start.ru_utime, &usr_diff);
>> + timersub(&stop.ru_stime, &start.ru_stime, &sys_diff);
>> +
>> + fprintf(stderr, "Time for %s: %ld.%06ld user, %ld.%06ld system\n",
>> + ct->rc_name, usr_diff.tv_sec, usr_diff.tv_usec,
>> + sys_diff.tv_sec, sys_diff.tv_usec);
>> +}
>> +
>> +static void crc32_func(struct run_context *ct, int nr)
>> +{
>> + uint32_t crc = ~0;
>> +
>> + crc = crc32_le(crc, ct->rc_data, ct->rc_size);
>> +}
>> +
>> +static void run_crc32(char *buf, int size, int count)
>> +{
>> + struct run_context ct = {
>> + .rc_name = "CRC32",
>> + .rc_data = buf,
>> + .rc_size = size,
>> + .rc_count = count,
>> + .rc_func = crc32_func,
>> + };
>> +
>> + timeme(&ct);
>> +}
>> +
>> +struct hamming_context {
>> + struct run_context hc_rc;
>> + uint32_t hc_ecc;
>> + int hc_ecc_valid;
>> + uint32_t (*hc_encode)(uint32_t parity, void *data, unsigned int d,
>> + unsigned int nr);
>> +};
>> +
>> +#define rc_to_hc(_rc) ((struct hamming_context *)(_rc))
>> +
>> +static void hamming_func(struct run_context *ct, int nr)
>> +{
>> + uint32_t ecc = 0;
>> + struct hamming_context *hc = rc_to_hc(ct);
>> +
>> + ecc = hc->hc_encode(ecc, ct->rc_data, ct->rc_size * 8, 0);
>> +
>> + if (hc->hc_ecc_valid) {
>> + if (hc->hc_ecc != ecc) {
>> + fprintf(stderr,
>> + "Calculated ecc %"PRIu32" != saved ecc %"PRIu32"\n",
>> + ecc, hc->hc_ecc);
>> + exit(1);
>> + }
>> + } else {
>> + assert(!nr);
>> + hc->hc_ecc = ecc;
>> + hc->hc_ecc_valid = 1;
>> + };
>> +}
>> +
>> +static void run_hamming(char *buf, int size, int count)
>> +{
>> + struct hamming_context hc = {
>> + .hc_rc = {
>> + .rc_name = "Original hamming code",
>> + .rc_data = buf,
>> + .rc_size = size,
>> + .rc_count = count,
>> + .rc_func = hamming_func,
>> + },
>> + .hc_encode = hamming_encode_orig,
>> + };
>> +
>> + timeme(&hc.hc_rc);
>> +
>> + hc.hc_rc.rc_name = "Current hamming code";
>> + hc.hc_encode = ocfs2_hamming_encode;
>> + timeme(&hc.hc_rc);
>> +
>> + hc.hc_rc.rc_name = "Parity xor with orig calc bits";
>> + hc.hc_encode = ocfs2_hamming_encode_orig_bits;
>> + timeme(&hc.hc_rc);
>> +
>> + hc.hc_rc.rc_name = "Parity xor with orig calc code bit";
>> + hc.hc_encode = ocfs2_hamming_encode_orig_code_bit;
>> + timeme(&hc.hc_rc);
>> +
>> + hc.hc_rc.rc_name = "Parity xor with cheating calc code bit";
>> + hc.hc_encode = ocfs2_hamming_encode_cheat_code_bit;
>> + timeme(&hc.hc_rc);
>> +
>> + hc.hc_rc.rc_name = "Current hamming code";
>> + hc.hc_encode = ocfs2_hamming_encode;
>> + timeme(&hc.hc_rc);
>> +}
>> +
>> +static uint64_t read_number(const char *num)
>> +{
>> + uint64_t val;
>> + char *ptr;
>> +
>> + val = strtoull(num, &ptr, 0);
>> + if (!ptr || *ptr)
>> + return 0;
>> +
>> + return val;
>> +}
>> +
>> +static void get_file(char *filename, char **buf, int *size)
>> +{
>> + int rc, fd, tot = 0;
>> + char *b;
>> + struct stat stat_buf;
>> +
>> + rc = stat(filename, &stat_buf);
>> + if (rc) {
>> + fprintf(stderr, "Unable to stat \"%s\": %s\n", filename,
>> + strerror(errno));
>> + exit(1);
>> + }
>> + if (!S_ISREG(stat_buf.st_mode)) {
>> + fprintf(stderr, "File \"%s\" is not a regular file\n",
>> + filename);
>> + exit(1);
>> + }
>> +
>> + b = malloc(stat_buf.st_size * sizeof(char));
>> + if (!b) {
>> + fprintf(stderr, "Unable to allocate buffer: %s\n",
>> + strerror(errno));
>> + exit(1);
>> + }
>> +
>> + fd = open(filename, O_RDONLY);
>> + if (fd < 0) {
>> + fprintf(stderr, "Unable to open \"%s\": %s\n", filename,
>> + strerror(errno));
>> + exit(1);
>> + }
>> +
>> + while (tot < stat_buf.st_size) {
>> + rc = read(fd, b + tot, stat_buf.st_size - tot);
>> + if (rc < 0) {
>> + fprintf(stderr, "Error reading from \"%s\": %s\n",
>> + filename, strerror(errno));
>> + exit(1);
>> + }
>> + if (!rc) {
>> + fprintf(stderr, "Unexpected EOF while reading from \"%s\"\n",
>> + filename);
>> + exit(1);
>> + }
>> + tot += rc;
>> + }
>> +
>> + close(fd);
>> + *size = stat_buf.st_size;
>> + *buf = b;
>> +}
>> +
>> +static void print_usage(void)
>> +{
>> + fprintf(stderr,
>> + "Usage: blockcheck <filename> [<count>]\n");
>> +}
>> +
>> +int main(int argc, char *argv[])
>> +{
>> + int size, count = 1;
>> + char *filename, *buf;
>> +
>> + initialize_ocfs_error_table();
>> +
>> + if (argc < 2) {
>> + fprintf(stderr, "Missing filename\n");
>> + print_usage();
>> + return 1;
>> + }
>> + filename = argv[1];
>> +
>> + if (argc > 2) {
>> + count = read_number(argv[2]);
>> + if (count < 1) {
>> + fprintf(stderr, "Invalid count: %d\n", count);
>> + print_usage();
>> + return 1;
>> + }
>> + }
>> +
>> + get_file(filename, &buf, &size);
>> + run_crc32(buf, size, count);
>> + run_hamming(buf, size, count);
>> +
>> +
>> +#if 0
>> + ocfs2_block_check_compute(buf, size, &check);
>> + fprintf(stdout, "crc32le: %"PRIu32", ecc: %"PRIu16"\n",
>> + le32_to_cpu(check.bc_crc32e), le16_to_cpu(check.bc_ecc));
>> +#endif
>> +
>> + free(buf);
>> +
>> + return 0;
>> +}
>> +
>> +#endif
>> diff --git a/libocfs2/blockcheck.h b/libocfs2/blockcheck.h
>> new file mode 100644
>> index 0000000..253d936
>> --- /dev/null
>> +++ b/libocfs2/blockcheck.h
>> @@ -0,0 +1,31 @@
>> +/* -*- mode: c; c-basic-offset: 8; -*-
>> + * vim: noexpandtab sw=8 ts=8 sts=0:
>> + *
>> + * blockcheck.h
>> + *
>> + * Checksum and ECC codes for the OCFS2 userspace library.
>> + *
>> + * Copyright (C) 2004, 2008 Oracle. All rights reserved.
>> + *
>> + * This program is free software; you can redistribute it and/or
>> + * modify it under the terms of the GNU General Public
>> + * License, version 2, as published by the Free Software Foundation.
>> + *
>> + * 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.
>> + */
>> +
>> +#ifndef _BLOCKCHECK_H
>> +#define _BLOCKCHECK_H
>> +
>> +extern uint32_t ocfs2_hamming_encode(uint32_t parity, void *data,
>> + unsigned int d, unsigned int nr);
>> +extern uint32_t ocfs2_hamming_encode_block(void *data, unsigned int d);
>> +extern void ocfs2_hamming_fix(void *data, unsigned int d, unsigned int nr,
>> + unsigned int fix);
>> +extern void ocfs2_hamming_fix_block(void *data, unsigned int d,
>> + unsigned int fix);
>> +extern uint32_t crc32_le(uint32_t crc, unsigned char const *p, size_t len);
>> +#endif
>> diff --git a/libocfs2/crc32table.h b/libocfs2/crc32table.h
>> new file mode 100644
>> index 0000000..67eae31
>> --- /dev/null
>> +++ b/libocfs2/crc32table.h
>> @@ -0,0 +1,150 @@
>> +/* this file is generated - do not edit */
>> +
>> +/*
>> + * This file is generated in the kernel sources by lib/gen_crc32table.c.
>> + * The following includes and defines are for our usage.
>> + */
>> +#include <inttypes.h>
>> +#include <byteswap.h>
>> +#if __BYTE_ORDER == __LITTLE_ENDIAN
>> +# define tole(x) ((uint32_t)(x))
>> +# define tobe(x) ((uint32_t)__bswap_constant_32(x))
>> +#elif __BYTE_ORDER == __BIG_ENDIAN
>> +# define tole(x) ((uint32_t)__bswap_constant_32(x))
>> +# define tobe(x) ((uint32_t)(x))
>> +#else
>> +# error Invalid byte order __BYTE_ORDER
>> +#endif
>> +
>> +static const uint32_t crc32table_le[] = {
>> +tole(0x00000000L), tole(0x77073096L), tole(0xee0e612cL),
>> tole(0x990951baL), +tole(0x076dc419L), tole(0x706af48fL),
>> tole(0xe963a535L), tole(0x9e6495a3L), +tole(0x0edb8832L),
>> tole(0x79dcb8a4L), tole(0xe0d5e91eL), tole(0x97d2d988L),
>> +tole(0x09b64c2bL), tole(0x7eb17cbdL), tole(0xe7b82d07L),
>> tole(0x90bf1d91L), +tole(0x1db71064L), tole(0x6ab020f2L),
>> tole(0xf3b97148L), tole(0x84be41deL), +tole(0x1adad47dL),
>> tole(0x6ddde4ebL), tole(0xf4d4b551L), tole(0x83d385c7L),
>> +tole(0x136c9856L), tole(0x646ba8c0L), tole(0xfd62f97aL),
>> tole(0x8a65c9ecL), +tole(0x14015c4fL), tole(0x63066cd9L),
>> tole(0xfa0f3d63L), tole(0x8d080df5L), +tole(0x3b6e20c8L),
>> tole(0x4c69105eL), tole(0xd56041e4L), tole(0xa2677172L),
>> +tole(0x3c03e4d1L), tole(0x4b04d447L), tole(0xd20d85fdL),
>> tole(0xa50ab56bL), +tole(0x35b5a8faL), tole(0x42b2986cL),
>> tole(0xdbbbc9d6L), tole(0xacbcf940L), +tole(0x32d86ce3L),
>> tole(0x45df5c75L), tole(0xdcd60dcfL), tole(0xabd13d59L),
>> +tole(0x26d930acL), tole(0x51de003aL), tole(0xc8d75180L),
>> tole(0xbfd06116L), +tole(0x21b4f4b5L), tole(0x56b3c423L),
>> tole(0xcfba9599L), tole(0xb8bda50fL), +tole(0x2802b89eL),
>> tole(0x5f058808L), tole(0xc60cd9b2L), tole(0xb10be924L),
>> +tole(0x2f6f7c87L), tole(0x58684c11L), tole(0xc1611dabL),
>> tole(0xb6662d3dL), +tole(0x76dc4190L), tole(0x01db7106L),
>> tole(0x98d220bcL), tole(0xefd5102aL), +tole(0x71b18589L),
>> tole(0x06b6b51fL), tole(0x9fbfe4a5L), tole(0xe8b8d433L),
>> +tole(0x7807c9a2L), tole(0x0f00f934L), tole(0x9609a88eL),
>> tole(0xe10e9818L), +tole(0x7f6a0dbbL), tole(0x086d3d2dL),
>> tole(0x91646c97L), tole(0xe6635c01L), +tole(0x6b6b51f4L),
>> tole(0x1c6c6162L), tole(0x856530d8L), tole(0xf262004eL),
>> +tole(0x6c0695edL), tole(0x1b01a57bL), tole(0x8208f4c1L),
>> tole(0xf50fc457L), +tole(0x65b0d9c6L), tole(0x12b7e950L),
>> tole(0x8bbeb8eaL), tole(0xfcb9887cL), +tole(0x62dd1ddfL),
>> tole(0x15da2d49L), tole(0x8cd37cf3L), tole(0xfbd44c65L),
>> +tole(0x4db26158L), tole(0x3ab551ceL), tole(0xa3bc0074L),
>> tole(0xd4bb30e2L), +tole(0x4adfa541L), tole(0x3dd895d7L),
>> tole(0xa4d1c46dL), tole(0xd3d6f4fbL), +tole(0x4369e96aL),
>> tole(0x346ed9fcL), tole(0xad678846L), tole(0xda60b8d0L),
>> +tole(0x44042d73L), tole(0x33031de5L), tole(0xaa0a4c5fL),
>> tole(0xdd0d7cc9L), +tole(0x5005713cL), tole(0x270241aaL),
>> tole(0xbe0b1010L), tole(0xc90c2086L), +tole(0x5768b525L),
>> tole(0x206f85b3L), tole(0xb966d409L), tole(0xce61e49fL),
>> +tole(0x5edef90eL), tole(0x29d9c998L), tole(0xb0d09822L),
>> tole(0xc7d7a8b4L), +tole(0x59b33d17L), tole(0x2eb40d81L),
>> tole(0xb7bd5c3bL), tole(0xc0ba6cadL), +tole(0xedb88320L),
>> tole(0x9abfb3b6L), tole(0x03b6e20cL), tole(0x74b1d29aL),
>> +tole(0xead54739L), tole(0x9dd277afL), tole(0x04db2615L),
>> tole(0x73dc1683L), +tole(0xe3630b12L), tole(0x94643b84L),
>> tole(0x0d6d6a3eL), tole(0x7a6a5aa8L), +tole(0xe40ecf0bL),
>> tole(0x9309ff9dL), tole(0x0a00ae27L), tole(0x7d079eb1L),
>> +tole(0xf00f9344L), tole(0x8708a3d2L), tole(0x1e01f268L),
>> tole(0x6906c2feL), +tole(0xf762575dL), tole(0x806567cbL),
>> tole(0x196c3671L), tole(0x6e6b06e7L), +tole(0xfed41b76L),
>> tole(0x89d32be0L), tole(0x10da7a5aL), tole(0x67dd4accL),
>> +tole(0xf9b9df6fL), tole(0x8ebeeff9L), tole(0x17b7be43L),
>> tole(0x60b08ed5L), +tole(0xd6d6a3e8L), tole(0xa1d1937eL),
>> tole(0x38d8c2c4L), tole(0x4fdff252L), +tole(0xd1bb67f1L),
>> tole(0xa6bc5767L), tole(0x3fb506ddL), tole(0x48b2364bL),
>> +tole(0xd80d2bdaL), tole(0xaf0a1b4cL), tole(0x36034af6L),
>> tole(0x41047a60L), +tole(0xdf60efc3L), tole(0xa867df55L),
>> tole(0x316e8eefL), tole(0x4669be79L), +tole(0xcb61b38cL),
>> tole(0xbc66831aL), tole(0x256fd2a0L), tole(0x5268e236L),
>> +tole(0xcc0c7795L), tole(0xbb0b4703L), tole(0x220216b9L),
>> tole(0x5505262fL), +tole(0xc5ba3bbeL), tole(0xb2bd0b28L),
>> tole(0x2bb45a92L), tole(0x5cb36a04L), +tole(0xc2d7ffa7L),
>> tole(0xb5d0cf31L), tole(0x2cd99e8bL), tole(0x5bdeae1dL),
>> +tole(0x9b64c2b0L), tole(0xec63f226L), tole(0x756aa39cL),
>> tole(0x026d930aL), +tole(0x9c0906a9L), tole(0xeb0e363fL),
>> tole(0x72076785L), tole(0x05005713L), +tole(0x95bf4a82L),
>> tole(0xe2b87a14L), tole(0x7bb12baeL), tole(0x0cb61b38L),
>> +tole(0x92d28e9bL), tole(0xe5d5be0dL), tole(0x7cdcefb7L),
>> tole(0x0bdbdf21L), +tole(0x86d3d2d4L), tole(0xf1d4e242L),
>> tole(0x68ddb3f8L), tole(0x1fda836eL), +tole(0x81be16cdL),
>> tole(0xf6b9265bL), tole(0x6fb077e1L), tole(0x18b74777L),
>> +tole(0x88085ae6L), tole(0xff0f6a70L), tole(0x66063bcaL),
>> tole(0x11010b5cL), +tole(0x8f659effL), tole(0xf862ae69L),
>> tole(0x616bffd3L), tole(0x166ccf45L), +tole(0xa00ae278L),
>> tole(0xd70dd2eeL), tole(0x4e048354L), tole(0x3903b3c2L),
>> +tole(0xa7672661L), tole(0xd06016f7L), tole(0x4969474dL),
>> tole(0x3e6e77dbL), +tole(0xaed16a4aL), tole(0xd9d65adcL),
>> tole(0x40df0b66L), tole(0x37d83bf0L), +tole(0xa9bcae53L),
>> tole(0xdebb9ec5L), tole(0x47b2cf7fL), tole(0x30b5ffe9L),
>> +tole(0xbdbdf21cL), tole(0xcabac28aL), tole(0x53b39330L),
>> tole(0x24b4a3a6L), +tole(0xbad03605L), tole(0xcdd70693L),
>> tole(0x54de5729L), tole(0x23d967bfL), +tole(0xb3667a2eL),
>> tole(0xc4614ab8L), tole(0x5d681b02L), tole(0x2a6f2b94L),
>> +tole(0xb40bbe37L), tole(0xc30c8ea1L), tole(0x5a05df1bL),
>> tole(0x2d02ef8dL)
>> +};
>> +static const uint32_t crc32table_be[] = {
>> +tobe(0x00000000L), tobe(0x04c11db7L), tobe(0x09823b6eL),
>> tobe(0x0d4326d9L), +tobe(0x130476dcL), tobe(0x17c56b6bL),
>> tobe(0x1a864db2L), tobe(0x1e475005L), +tobe(0x2608edb8L),
>> tobe(0x22c9f00fL), tobe(0x2f8ad6d6L), tobe(0x2b4bcb61L),
>> +tobe(0x350c9b64L), tobe(0x31cd86d3L), tobe(0x3c8ea00aL),
>> tobe(0x384fbdbdL), +tobe(0x4c11db70L), tobe(0x48d0c6c7L),
>> tobe(0x4593e01eL), tobe(0x4152fda9L), +tobe(0x5f15adacL),
>> tobe(0x5bd4b01bL), tobe(0x569796c2L), tobe(0x52568b75L),
>> +tobe(0x6a1936c8L), tobe(0x6ed82b7fL), tobe(0x639b0da6L),
>> tobe(0x675a1011L), +tobe(0x791d4014L), tobe(0x7ddc5da3L),
>> tobe(0x709f7b7aL), tobe(0x745e66cdL), +tobe(0x9823b6e0L),
>> tobe(0x9ce2ab57L), tobe(0x91a18d8eL), tobe(0x95609039L),
>> +tobe(0x8b27c03cL), tobe(0x8fe6dd8bL), tobe(0x82a5fb52L),
>> tobe(0x8664e6e5L), +tobe(0xbe2b5b58L), tobe(0xbaea46efL),
>> tobe(0xb7a96036L), tobe(0xb3687d81L), +tobe(0xad2f2d84L),
>> tobe(0xa9ee3033L), tobe(0xa4ad16eaL), tobe(0xa06c0b5dL),
>> +tobe(0xd4326d90L), tobe(0xd0f37027L), tobe(0xddb056feL),
>> tobe(0xd9714b49L), +tobe(0xc7361b4cL), tobe(0xc3f706fbL),
>> tobe(0xceb42022L), tobe(0xca753d95L), +tobe(0xf23a8028L),
>> tobe(0xf6fb9d9fL), tobe(0xfbb8bb46L), tobe(0xff79a6f1L),
>> +tobe(0xe13ef6f4L), tobe(0xe5ffeb43L), tobe(0xe8bccd9aL),
>> tobe(0xec7dd02dL), +tobe(0x34867077L), tobe(0x30476dc0L),
>> tobe(0x3d044b19L), tobe(0x39c556aeL), +tobe(0x278206abL),
>> tobe(0x23431b1cL), tobe(0x2e003dc5L), tobe(0x2ac12072L),
>> +tobe(0x128e9dcfL), tobe(0x164f8078L), tobe(0x1b0ca6a1L),
>> tobe(0x1fcdbb16L), +tobe(0x018aeb13L), tobe(0x054bf6a4L),
>> tobe(0x0808d07dL), tobe(0x0cc9cdcaL), +tobe(0x7897ab07L),
>> tobe(0x7c56b6b0L), tobe(0x71159069L), tobe(0x75d48ddeL),
>> +tobe(0x6b93dddbL), tobe(0x6f52c06cL), tobe(0x6211e6b5L),
>> tobe(0x66d0fb02L), +tobe(0x5e9f46bfL), tobe(0x5a5e5b08L),
>> tobe(0x571d7dd1L), tobe(0x53dc6066L), +tobe(0x4d9b3063L),
>> tobe(0x495a2dd4L), tobe(0x44190b0dL), tobe(0x40d816baL),
>> +tobe(0xaca5c697L), tobe(0xa864db20L), tobe(0xa527fdf9L),
>> tobe(0xa1e6e04eL), +tobe(0xbfa1b04bL), tobe(0xbb60adfcL),
>> tobe(0xb6238b25L), tobe(0xb2e29692L), +tobe(0x8aad2b2fL),
>> tobe(0x8e6c3698L), tobe(0x832f1041L), tobe(0x87ee0df6L),
>> +tobe(0x99a95df3L), tobe(0x9d684044L), tobe(0x902b669dL),
>> tobe(0x94ea7b2aL), +tobe(0xe0b41de7L), tobe(0xe4750050L),
>> tobe(0xe9362689L), tobe(0xedf73b3eL), +tobe(0xf3b06b3bL),
>> tobe(0xf771768cL), tobe(0xfa325055L), tobe(0xfef34de2L),
>> +tobe(0xc6bcf05fL), tobe(0xc27dede8L), tobe(0xcf3ecb31L),
>> tobe(0xcbffd686L), +tobe(0xd5b88683L), tobe(0xd1799b34L),
>> tobe(0xdc3abdedL), tobe(0xd8fba05aL), +tobe(0x690ce0eeL),
>> tobe(0x6dcdfd59L), tobe(0x608edb80L), tobe(0x644fc637L),
>> +tobe(0x7a089632L), tobe(0x7ec98b85L), tobe(0x738aad5cL),
>> tobe(0x774bb0ebL), +tobe(0x4f040d56L), tobe(0x4bc510e1L),
>> tobe(0x46863638L), tobe(0x42472b8fL), +tobe(0x5c007b8aL),
>> tobe(0x58c1663dL), tobe(0x558240e4L), tobe(0x51435d53L),
>> +tobe(0x251d3b9eL), tobe(0x21dc2629L), tobe(0x2c9f00f0L),
>> tobe(0x285e1d47L), +tobe(0x36194d42L), tobe(0x32d850f5L),
>> tobe(0x3f9b762cL), tobe(0x3b5a6b9bL), +tobe(0x0315d626L),
>> tobe(0x07d4cb91L), tobe(0x0a97ed48L), tobe(0x0e56f0ffL),
>> +tobe(0x1011a0faL), tobe(0x14d0bd4dL), tobe(0x19939b94L),
>> tobe(0x1d528623L), +tobe(0xf12f560eL), tobe(0xf5ee4bb9L),
>> tobe(0xf8ad6d60L), tobe(0xfc6c70d7L), +tobe(0xe22b20d2L),
>> tobe(0xe6ea3d65L), tobe(0xeba91bbcL), tobe(0xef68060bL),
>> +tobe(0xd727bbb6L), tobe(0xd3e6a601L), tobe(0xdea580d8L),
>> tobe(0xda649d6fL), +tobe(0xc423cd6aL), tobe(0xc0e2d0ddL),
>> tobe(0xcda1f604L), tobe(0xc960ebb3L), +tobe(0xbd3e8d7eL),
>> tobe(0xb9ff90c9L), tobe(0xb4bcb610L), tobe(0xb07daba7L),
>> +tobe(0xae3afba2L), tobe(0xaafbe615L), tobe(0xa7b8c0ccL),
>> tobe(0xa379dd7bL), +tobe(0x9b3660c6L), tobe(0x9ff77d71L),
>> tobe(0x92b45ba8L), tobe(0x9675461fL), +tobe(0x8832161aL),
>> tobe(0x8cf30badL), tobe(0x81b02d74L), tobe(0x857130c3L),
>> +tobe(0x5d8a9099L), tobe(0x594b8d2eL), tobe(0x5408abf7L),
>> tobe(0x50c9b640L), +tobe(0x4e8ee645L), tobe(0x4a4ffbf2L),
>> tobe(0x470cdd2bL), tobe(0x43cdc09cL), +tobe(0x7b827d21L),
>> tobe(0x7f436096L), tobe(0x7200464fL), tobe(0x76c15bf8L),
>> +tobe(0x68860bfdL), tobe(0x6c47164aL), tobe(0x61043093L),
>> tobe(0x65c52d24L), +tobe(0x119b4be9L), tobe(0x155a565eL),
>> tobe(0x18197087L), tobe(0x1cd86d30L), +tobe(0x029f3d35L),
>> tobe(0x065e2082L), tobe(0x0b1d065bL), tobe(0x0fdc1becL),
>> +tobe(0x3793a651L), tobe(0x3352bbe6L), tobe(0x3e119d3fL),
>> tobe(0x3ad08088L), +tobe(0x2497d08dL), tobe(0x2056cd3aL),
>> tobe(0x2d15ebe3L), tobe(0x29d4f654L), +tobe(0xc5a92679L),
>> tobe(0xc1683bceL), tobe(0xcc2b1d17L), tobe(0xc8ea00a0L),
>> +tobe(0xd6ad50a5L), tobe(0xd26c4d12L), tobe(0xdf2f6bcbL),
>> tobe(0xdbee767cL), +tobe(0xe3a1cbc1L), tobe(0xe760d676L),
>> tobe(0xea23f0afL), tobe(0xeee2ed18L), +tobe(0xf0a5bd1dL),
>> tobe(0xf464a0aaL), tobe(0xf9278673L), tobe(0xfde69bc4L),
>> +tobe(0x89b8fd09L), tobe(0x8d79e0beL), tobe(0x803ac667L),
>> tobe(0x84fbdbd0L), +tobe(0x9abc8bd5L), tobe(0x9e7d9662L),
>> tobe(0x933eb0bbL), tobe(0x97ffad0cL), +tobe(0xafb010b1L),
>> tobe(0xab710d06L), tobe(0xa6322bdfL), tobe(0xa2f33668L),
>> +tobe(0xbcb4666dL), tobe(0xb8757bdaL), tobe(0xb5365d03L),
>> tobe(0xb1f740b4L)
>> +};
>>
>
--
Joel's First Law:
Nature abhors a GUI.
Joel Becker
Principal Software Developer
Oracle
E-mail: joel.becker at oracle.com
Phone: (650) 506-8127
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