e2fsprogs/ext2fs/ind_block.c

   1 /*
   2  * ind_block.c --- indirect block I/O routines
   3  *
   4  * Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
   5  *      2001, 2002, 2003, 2004, 2005 by  Theodore Ts'o.
   6  *
   7  * %Begin-Header%
   8  * This file may be redistributed under the terms of the GNU Public
   9  * License.
  10  * %End-Header%
  11  */
  12
  13 #include <stdio.h>
  14 #include <string.h>
  15 #if HAVE_UNISTD_H
  16 #include <unistd.h>
  17 #endif
  18
  19 #include "ext2_fs.h"
  20 #include "ext2fs.h"
  21
  22 errcode_t ext2fs_read_ind_block(ext2_filsys fs, blk_t blk, void *buf)
  23 {
  24         errcode_t       retval;
  25 #ifdef EXT2FS_ENABLE_SWAPFS
  26         blk_t           *block_nr;
  27         int             i;
  28         int             limit = fs->blocksize >> 2;
  29 #endif
  30
  31         if ((fs->flags & EXT2_FLAG_IMAGE_FILE) &&
  32             (fs->io != fs->image_io))
  33                 memset(buf, 0, fs->blocksize);
  34         else {
  35                 retval = io_channel_read_blk(fs->io, blk, 1, buf);
  36                 if (retval)
  37                         return retval;
  38         }
  39 #ifdef EXT2FS_ENABLE_SWAPFS
  40         if (fs->flags & (EXT2_FLAG_SWAP_BYTES | EXT2_FLAG_SWAP_BYTES_READ)) {
  41                 block_nr = (blk_t *) buf;
  42                 for (i = 0; i < limit; i++, block_nr++)
  43                         *block_nr = ext2fs_swab32(*block_nr);
  44         }
  45 #endif
  46         return 0;
  47 }
  48
  49 errcode_t ext2fs_write_ind_block(ext2_filsys fs, blk_t blk, void *buf)
  50 {
  51 #ifdef EXT2FS_ENABLE_SWAPFS
  52         blk_t           *block_nr;
  53         int             i;
  54         int             limit = fs->blocksize >> 2;
  55 #endif
  56
  57         if (fs->flags & EXT2_FLAG_IMAGE_FILE)
  58                 return 0;
  59
  60 #ifdef EXT2FS_ENABLE_SWAPFS
  61         if (fs->flags & (EXT2_FLAG_SWAP_BYTES | EXT2_FLAG_SWAP_BYTES_WRITE)) {
  62                 block_nr = (blk_t *) buf;
  63                 for (i = 0; i < limit; i++, block_nr++)
  64                         *block_nr = ext2fs_swab32(*block_nr);
  65         }
  66 #endif
  67         return io_channel_write_blk(fs->io, blk, 1, buf);
  68 }
  69
  70