release/src/router/busybox/e2fsprogs/old_e2fsprogs/ext2fs/ind_block.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * ind_block.c --- indirect block I/O routines
   4  *
   5  * Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
   6  *      2001, 2002, 2003, 2004, 2005 by  Theodore Ts'o.
   7  *
   8  * %Begin-Header%
   9  * This file may be redistributed under the terms of the GNU Public
  10  * License.
  11  * %End-Header%
  12  */
  13
  14 #include <stdio.h>
  15 #include <string.h>
  16 #if HAVE_UNISTD_H
  17 #include <unistd.h>
  18 #endif
  19
  20 #include "ext2_fs.h"
  21 #include "ext2fs.h"
  22
  23 errcode_t ext2fs_read_ind_block(ext2_filsys fs, blk_t blk, void *buf)
  24 {
  25         errcode_t       retval;
  26 #if BB_BIG_ENDIAN
  27         blk_t           *block_nr;
  28         int             i;
  29         int             limit = fs->blocksize >> 2;
  30 #endif
  31
  32         if ((fs->flags & EXT2_FLAG_IMAGE_FILE) &&
  33             (fs->io != fs->image_io))
  34                 memset(buf, 0, fs->blocksize);
  35         else {
  36                 retval = io_channel_read_blk(fs->io, blk, 1, buf);
  37                 if (retval)
  38                         return retval;
  39         }
  40 #if BB_BIG_ENDIAN
  41         if (fs->flags & (EXT2_FLAG_SWAP_BYTES | EXT2_FLAG_SWAP_BYTES_READ)) {
  42                 block_nr = (blk_t *) buf;
  43                 for (i = 0; i < limit; i++, block_nr++)
  44                         *block_nr = ext2fs_swab32(*block_nr);
  45         }
  46 #endif
  47         return 0;
  48 }
  49
  50 errcode_t ext2fs_write_ind_block(ext2_filsys fs, blk_t blk, void *buf)
  51 {
  52 #if BB_BIG_ENDIAN
  53         blk_t           *block_nr;
  54         int             i;
  55         int             limit = fs->blocksize >> 2;
  56 #endif
  57
  58         if (fs->flags & EXT2_FLAG_IMAGE_FILE)
  59                 return 0;
  60
  61 #if BB_BIG_ENDIAN
  62         if (fs->flags & (EXT2_FLAG_SWAP_BYTES | EXT2_FLAG_SWAP_BYTES_WRITE)) {
  63                 block_nr = (blk_t *) buf;
  64                 for (i = 0; i < limit; i++, block_nr++)
  65                         *block_nr = ext2fs_swab32(*block_nr);
  66         }
  67 #endif
  68         return io_channel_write_blk(fs->io, blk, 1, buf);
  69 }