LXR busybox/e2fsprogs/old_e2fsprogs/ext2fs/ind

   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
  23errcode_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
  50errcode_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}
  70