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      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 Library
      9  * General Public License, version 2.
     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 WORDS_BIGENDIAN
     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 WORDS_BIGENDIAN
     40 	block_nr = (blk_t *) buf;
     41 	for (i = 0; i < limit; i++, block_nr++)
     42 		*block_nr = ext2fs_swab32(*block_nr);
     43 #endif
     44 	return 0;
     45 }
     46 
     47 errcode_t ext2fs_write_ind_block(ext2_filsys fs, blk_t blk, void *buf)
     48 {
     49 #ifdef WORDS_BIGENDIAN
     50 	blk_t		*block_nr;
     51 	int		i;
     52 	int		limit = fs->blocksize >> 2;
     53 #endif
     54 
     55 	if (fs->flags & EXT2_FLAG_IMAGE_FILE)
     56 		return 0;
     57 
     58 #ifdef WORDS_BIGENDIAN
     59 	block_nr = (blk_t *) buf;
     60 	for (i = 0; i < limit; i++, block_nr++)
     61 		*block_nr = ext2fs_swab32(*block_nr);
     62 #endif
     63 	return io_channel_write_blk(fs->io, blk, 1, buf);
     64 }
     65 
     66 
     67