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d0429e1c88
mkfs just needs to initialize bloom filter blocks with the bits for the single root inode key. We can get away with these skeletal functions for now. Signed-off-by: Zach Brown <zab@versity.com>
67 lines
1.9 KiB
C
67 lines
1.9 KiB
C
/*
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* Copyright (C) 2016 Versity Software, Inc. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public
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* License v2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*/
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#include "sparse.h"
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#include "util.h"
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#include "format.h"
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#include "bloom.h"
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#include "crc.h"
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#include "bitops.h"
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/* XXX garbage hack until we have siphash */
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static u32 bloom_hash(struct scoutfs_key *key, __le32 salt)
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{
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return crc32c(le32_to_cpu(salt), key, sizeof(struct scoutfs_key));
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}
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/*
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* Find the bits in the bloom filter for the given key. The caller calculates
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* these once and uses them to test all the blocks.
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*/
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void scoutfs_calc_bloom_bits(struct scoutfs_bloom_bits *bits,
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struct scoutfs_key *key, __le32 *salts)
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{
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unsigned h_bits = 0;
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unsigned s = 0;
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u64 h = 0;
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int i;
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for (i = 0; i < SCOUTFS_BLOOM_BITS; i++) {
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if (h_bits < SCOUTFS_BLOOM_BIT_WIDTH) {
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h = (h << 32) | bloom_hash(key, salts[s++]);
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h += 32;
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}
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bits->nr[i] = h & SCOUTFS_BLOOM_BIT_MASK;
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h >>= SCOUTFS_BLOOM_BIT_WIDTH;
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h_bits -= SCOUTFS_BLOOM_BIT_WIDTH;
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}
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}
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/*
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* This interface is different than in the kernel because we don't
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* have a block IO interface here yet. The caller gives us each
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* bloom block and we set each bit that falls in the block.
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*/
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void scoutfs_set_bloom_bits(struct scoutfs_bloom_block *blm, unsigned int nr,
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struct scoutfs_bloom_bits *bits)
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{
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int i;
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for (i = 0; i < SCOUTFS_BLOOM_BITS; i++) {
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if (nr == (bits->nr[i] / SCOUTFS_BLOOM_BITS_PER_BLOCK)) {
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set_bit_le(bits->nr[i] % SCOUTFS_BLOOM_BITS_PER_BLOCK,
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blm->bits);
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}
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}
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}
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