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  */
  24 int
  25 befs_load_sb(struct super_block *sb, befs_super_block * disk_sb)
  26 {
  27         struct 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
  59 int
  60 befs_check_sb(struct super_block *sb)
  61 {
  62         struct 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 }