LXR linux/fs/befs/super.c

   1/*
   2 * super.c
   3 *
   4 * Copyright (C) 2001-2002 Will Dyson <will_dyson@pobox.com>
   5 *
   6 * Licensed under the GNU GPL. See the file COPYING for details.
   7 *
   8 */
   9
  10#include <linux/fs.h>
  11#include <asm/page.h> /* for PAGE_SIZE */
  12
  13#include "befs.h"
  14#include "super.h"
  15
  16/**
  17 * load_befs_sb -- Read from disk and properly byteswap all the fields
  18 * of the befs superblock
  19 *
  20 *
  21 *
  22 *
  23 */
  24int
  25befs_load_sb(struct super_block *sb, befs_super_block * disk_sb)
  26{
  27        befs_sb_info *befs_sb = BEFS_SB(sb);
  28
  29        /* Check the byte order of the filesystem */
  30        if (disk_sb->fs_byte_order == BEFS_BYTEORDER_NATIVE_LE)
  31            befs_sb->byte_order = BEFS_BYTESEX_LE;
  32        else if (disk_sb->fs_byte_order == BEFS_BYTEORDER_NATIVE_BE)
  33            befs_sb->byte_order = BEFS_BYTESEX_BE;
  34
  35        befs_sb->magic1 = fs32_to_cpu(sb, disk_sb->magic1);
  36        befs_sb->magic2 = fs32_to_cpu(sb, disk_sb->magic2);
  37        befs_sb->magic3 = fs32_to_cpu(sb, disk_sb->magic3);
  38        befs_sb->block_size = fs32_to_cpu(sb, disk_sb->block_size);
  39        befs_sb->block_shift = fs32_to_cpu(sb, disk_sb->block_shift);
  40        befs_sb->num_blocks = fs64_to_cpu(sb, disk_sb->num_blocks);
  41        befs_sb->used_blocks = fs64_to_cpu(sb, disk_sb->used_blocks);
  42        befs_sb->inode_size = fs32_to_cpu(sb, disk_sb->inode_size);
  43
  44        befs_sb->blocks_per_ag = fs32_to_cpu(sb, disk_sb->blocks_per_ag);
  45        befs_sb->ag_shift = fs32_to_cpu(sb, disk_sb->ag_shift);
  46        befs_sb->num_ags = fs32_to_cpu(sb, disk_sb->num_ags);
  47
  48        befs_sb->log_blocks = fsrun_to_cpu(sb, disk_sb->log_blocks);
  49        befs_sb->log_start = fs64_to_cpu(sb, disk_sb->log_start);
  50        befs_sb->log_end = fs64_to_cpu(sb, disk_sb->log_end);
  51
  52        befs_sb->root_dir = fsrun_to_cpu(sb, disk_sb->root_dir);
  53        befs_sb->indices = fsrun_to_cpu(sb, disk_sb->indices);
  54        befs_sb->nls = NULL;
  55
  56        return BEFS_OK;
  57}
  58
  59int
  60befs_check_sb(struct super_block *sb)
  61{
  62        befs_sb_info *befs_sb = BEFS_SB(sb);
  63
  64        /* Check magic headers of super block */
  65        if ((befs_sb->magic1 != BEFS_SUPER_MAGIC1)
  66            || (befs_sb->magic2 != BEFS_SUPER_MAGIC2)
  67            || (befs_sb->magic3 != BEFS_SUPER_MAGIC3)) {
  68                befs_error(sb, "invalid magic header");
  69                return BEFS_ERR;
  70        }
  71
  72        /*
  73         * Check blocksize of BEFS.
  74         *
  75         * Blocksize of BEFS is 1024, 2048, 4096 or 8192.
  76         */
  77
  78        if ((befs_sb->block_size != 1024)
  79            && (befs_sb->block_size != 2048)
  80            && (befs_sb->block_size != 4096)
  81            && (befs_sb->block_size != 8192)) {
  82                befs_error(sb, "invalid blocksize: %u", befs_sb->block_size);
  83                return BEFS_ERR;
  84        }
  85
  86        if (befs_sb->block_size > PAGE_SIZE) {
  87                befs_error(sb, "blocksize(%u) cannot be larger"
  88                           "than system pagesize(%lu)", befs_sb->block_size,
  89                           PAGE_SIZE);
  90                return BEFS_ERR;
  91        }
  92
  93        /*
  94           * block_shift and block_size encode the same information
  95           * in different ways as a consistency check.
  96         */
  97
  98        if ((1 << befs_sb->block_shift) != befs_sb->block_size) {
  99                befs_error(sb, "block_shift disagrees with block_size. "
 100                           "Corruption likely.");
 101                return BEFS_ERR;
 102        }
 103
 104        if (befs_sb->log_start != befs_sb->log_end) {
 105                befs_error(sb, "Filesystem not clean! There are blocks in the "
 106                           "journal. You must boot into BeOS and mount this volume "
 107                           "to make it clean.");
 108                return BEFS_ERR;
 109        }
 110
 111        return BEFS_OK;
 112}
 113