LXR uboot/fs/zfs/zfs

   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#include <common.h>
  25#include <malloc.h>
  26#include <linux/stat.h>
  27#include <linux/time.h>
  28#include <linux/ctype.h>
  29#include <asm/byteorder.h>
  30#include "zfs_common.h"
  31
  32#include <zfs/zfs.h>
  33#include <zfs/zio.h>
  34#include <zfs/dnode.h>
  35#include <zfs/uberblock_impl.h>
  36#include <zfs/vdev_impl.h>
  37#include <zfs/zio_checksum.h>
  38#include <zfs/zap_impl.h>
  39#include <zfs/zap_leaf.h>
  40#include <zfs/zfs_znode.h>
  41#include <zfs/dmu.h>
  42#include <zfs/dmu_objset.h>
  43#include <zfs/dsl_dir.h>
  44#include <zfs/dsl_dataset.h>
  45
  46#define MATCH_BITS      6
  47#define MATCH_MIN       3
  48#define OFFSET_MASK     ((1 << (16 - MATCH_BITS)) - 1)
  49
  50/*
  51 * Decompression Entry - lzjb
  52 */
  53#ifndef NBBY
  54#define NBBY    8
  55#endif
  56
  57int
  58lzjb_decompress(void *s_start, void *d_start, uint32_t s_len,
  59                                uint32_t d_len)
  60{
  61        uint8_t *src = s_start;
  62        uint8_t *dst = d_start;
  63        uint8_t *d_end = (uint8_t *) d_start + d_len;
  64        uint8_t *s_end = (uint8_t *) s_start + s_len;
  65        uint8_t *cpy, copymap = 0;
  66        int copymask = 1 << (NBBY - 1);
  67
  68        while (dst < d_end && src < s_end) {
  69                if ((copymask <<= 1) == (1 << NBBY)) {
  70                        copymask = 1;
  71                        copymap = *src++;
  72                }
  73                if (src >= s_end) {
  74                        printf("lzjb decompression failed\n");
  75                        return ZFS_ERR_BAD_FS;
  76                }
  77                if (copymap & copymask) {
  78                        int mlen = (src[0] >> (NBBY - MATCH_BITS)) + MATCH_MIN;
  79                        int offset = ((src[0] << NBBY) | src[1]) & OFFSET_MASK;
  80                        src += 2;
  81                        cpy = dst - offset;
  82                        if (src > s_end || cpy < (uint8_t *) d_start) {
  83                                printf("lzjb decompression failed\n");
  84                                return ZFS_ERR_BAD_FS;
  85                        }
  86                        while (--mlen >= 0 && dst < d_end)
  87                                *dst++ = *cpy++;
  88                } else {
  89                        *dst++ = *src++;
  90                }
  91        }
  92        if (dst < d_end) {
  93                printf("lzjb decompression failed\n");
  94                return ZFS_ERR_BAD_FS;
  95        }
  96        return ZFS_ERR_NONE;
  97}
  98