mirror of https://github.com/hak5/openwrt-owl.git
98 lines
2.3 KiB
C
98 lines
2.3 KiB
C
/*
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* YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
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*
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* Copyright (C) 2002-2011 Aleph One Ltd.
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* for Toby Churchill Ltd and Brightstar Engineering
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*
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* Created by Charles Manning <charles@aleph1.co.uk>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include "yaffs_bitmap.h"
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#include "yaffs_trace.h"
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/*
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* Chunk bitmap manipulations
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*/
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static inline u8 *yaffs_block_bits(struct yaffs_dev *dev, int blk)
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{
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if (blk < dev->internal_start_block || blk > dev->internal_end_block) {
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yaffs_trace(YAFFS_TRACE_ERROR,
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"BlockBits block %d is not valid",
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blk);
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BUG();
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}
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return dev->chunk_bits +
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(dev->chunk_bit_stride * (blk - dev->internal_start_block));
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}
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void yaffs_verify_chunk_bit_id(struct yaffs_dev *dev, int blk, int chunk)
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{
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if (blk < dev->internal_start_block || blk > dev->internal_end_block ||
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chunk < 0 || chunk >= dev->param.chunks_per_block) {
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yaffs_trace(YAFFS_TRACE_ERROR,
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"Chunk Id (%d:%d) invalid",
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blk, chunk);
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BUG();
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}
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}
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void yaffs_clear_chunk_bits(struct yaffs_dev *dev, int blk)
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{
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u8 *blk_bits = yaffs_block_bits(dev, blk);
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memset(blk_bits, 0, dev->chunk_bit_stride);
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}
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void yaffs_clear_chunk_bit(struct yaffs_dev *dev, int blk, int chunk)
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{
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u8 *blk_bits = yaffs_block_bits(dev, blk);
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yaffs_verify_chunk_bit_id(dev, blk, chunk);
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blk_bits[chunk / 8] &= ~(1 << (chunk & 7));
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}
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void yaffs_set_chunk_bit(struct yaffs_dev *dev, int blk, int chunk)
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{
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u8 *blk_bits = yaffs_block_bits(dev, blk);
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yaffs_verify_chunk_bit_id(dev, blk, chunk);
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blk_bits[chunk / 8] |= (1 << (chunk & 7));
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}
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int yaffs_check_chunk_bit(struct yaffs_dev *dev, int blk, int chunk)
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{
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u8 *blk_bits = yaffs_block_bits(dev, blk);
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yaffs_verify_chunk_bit_id(dev, blk, chunk);
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return (blk_bits[chunk / 8] & (1 << (chunk & 7))) ? 1 : 0;
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}
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int yaffs_still_some_chunks(struct yaffs_dev *dev, int blk)
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{
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u8 *blk_bits = yaffs_block_bits(dev, blk);
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int i;
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for (i = 0; i < dev->chunk_bit_stride; i++) {
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if (*blk_bits)
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return 1;
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blk_bits++;
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}
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return 0;
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}
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int yaffs_count_chunk_bits(struct yaffs_dev *dev, int blk)
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{
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u8 *blk_bits = yaffs_block_bits(dev, blk);
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int i;
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int n = 0;
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for (i = 0; i < dev->chunk_bit_stride; i++, blk_bits++)
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n += hweight8(*blk_bits);
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return n;
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}
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