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
  12 #include "befs.h"
  13 #include "super.h"
  14
  15 /**
  16  * load_befs_sb -- Read from disk and properly byteswap all the fields
  17  * of the befs superblock
  18  *
  19  *
  20  *
  21  *
  22  */
  23 int
  24 befs_load_sb(struct super_block *sb, befs_super_block * disk_sb)
  25 {
  26         befs_sb_info *befs_sb = BEFS_SB(sb);
  27
  28         /* Check the byte order of the filesystem */
  29         if (le32_to_cpu(disk_sb->fs_byte_order) == BEFS_BYTEORDER_NATIVE)
  30             befs_sb->byte_order = BEFS_BYTESEX_LE;
  31         else if (be32_to_cpu(disk_sb->fs_byte_order) == BEFS_BYTEORDER_NATIVE)
  32             befs_sb->byte_order = BEFS_BYTESEX_BE;
  33
  34         befs_sb->magic1 = fs32_to_cpu(sb, disk_sb->magic1);
  35         befs_sb->magic2 = fs32_to_cpu(sb, disk_sb->magic2);
  36         befs_sb->magic3 = fs32_to_cpu(sb, disk_sb->magic3);
  37         befs_sb->block_size = fs32_to_cpu(sb, disk_sb->block_size);
  38         befs_sb->block_shift = fs32_to_cpu(sb, disk_sb->block_shift);
  39         befs_sb->num_blocks = fs64_to_cpu(sb, disk_sb->num_blocks);
  40         befs_sb->used_blocks = fs64_to_cpu(sb, disk_sb->used_blocks);
  41         befs_sb->inode_size = fs32_to_cpu(sb, disk_sb->inode_size);
  42
  43         befs_sb->blocks_per_ag = fs32_to_cpu(sb, disk_sb->blocks_per_ag);
  44         befs_sb->ag_shift = fs32_to_cpu(sb, disk_sb->ag_shift);
  45         befs_sb->num_ags = fs32_to_cpu(sb, disk_sb->num_ags);
  46
  47         befs_sb->log_blocks = fsrun_to_cpu(sb, disk_sb->log_blocks);
  48         befs_sb->log_start = fs64_to_cpu(sb, disk_sb->log_start);
  49         befs_sb->log_end = fs64_to_cpu(sb, disk_sb->log_end);
  50
  51         befs_sb->root_dir = fsrun_to_cpu(sb, disk_sb->root_dir);
  52         befs_sb->indices = fsrun_to_cpu(sb, disk_sb->indices);
  53         befs_sb->nls = NULL;
  54
  55         return BEFS_OK;
  56 }
  57
  58 int
  59 befs_check_sb(struct super_block *sb)
  60 {
  61         befs_sb_info *befs_sb = BEFS_SB(sb);
  62
  63         /* Check magic headers of super block */
  64         if ((befs_sb->magic1 != BEFS_SUPER_MAGIC1)
  65             || (befs_sb->magic2 != BEFS_SUPER_MAGIC2)
  66             || (befs_sb->magic3 != BEFS_SUPER_MAGIC3)) {
  67                 befs_error(sb, "invalid magic header");
  68                 return BEFS_ERR;
  69         }
  70
  71         /*
  72          * Check blocksize of BEFS.
  73          *
  74          * Blocksize of BEFS is 1024, 2048, 4096 or 8192.
  75          */
  76
  77         if ((befs_sb->block_size != 1024)
  78             && (befs_sb->block_size != 2048)
  79             && (befs_sb->block_size != 4096)
  80             && (befs_sb->block_size != 8192)) {
  81                 befs_error(sb, "invalid blocksize: %u", befs_sb->block_size);
  82                 return BEFS_ERR;
  83         }
  84
  85         if (befs_sb->block_size > PAGE_SIZE) {
  86                 befs_error(sb, "blocksize(%u) cannot be larger"
  87                            "than system pagesize(%lu)", befs_sb->block_size,
  88                            PAGE_SIZE);
  89                 return BEFS_ERR;
  90         }
  91
  92         /*
  93            * block_shift and block_size encode the same information
  94            * in different ways as a consistency check.
  95          */
  96
  97         if ((1 << befs_sb->block_shift) != befs_sb->block_size) {
  98                 befs_error(sb, "block_shift disagrees with block_size. "
  99                            "Corruption likely.");
 100                 return BEFS_ERR;
 101         }
 102
 103         if (befs_sb->log_start != befs_sb->log_end) {
 104                 befs_error(sb, "Filesystem not clean! There are blocks in the "
 105                            "journal. You must boot into BeOS and mount this volume "
 106                            "to make it clean.");
 107                 return BEFS_ERR;
 108         }
 109
 110         return BEFS_OK;
 111 }