text: /*
   * bitmaps.c --- routines to read, write, and manipulate the inode and
   * block bitmaps.
   *
   * Copyright (C) 1993, 1994, 1995, 1996 Theodore Ts'o.
   *
   * %Begin-Header%
   * This file may be redistributed under the terms of the GNU Public
   * License.
   * %End-Header%
   */
  
  #include <stdio.h>
  #include <string.h>
  #if HAVE_UNISTD_H
  #include <unistd.h>
  #endif
  #include <fcntl.h>
  #include <time.h>
  #if HAVE_SYS_STAT_H
  #include <sys/stat.h>
  #endif
  #if HAVE_SYS_TYPES_H
  #include <sys/types.h>
  #endif
  
  #include "ext2_fs.h"
  #include "ext2fs.h"
  
  static errcode_t make_bitmap(__u32 start, __u32 end, __u32 real_end,
  			     const char *descr, char *init_map,
  			     ext2fs_generic_bitmap *ret)
  {
  	ext2fs_generic_bitmap	bitmap;
  	errcode_t		retval;
  	size_t			size;
  
  	retval = ext2fs_get_mem(sizeof(struct ext2fs_struct_generic_bitmap),
  				(void **) &bitmap);
  	if (retval)
  		return retval;
  
  	bitmap->magic = EXT2_ET_MAGIC_GENERIC_BITMAP;
  	bitmap->fs = NULL;
  	bitmap->start = start;
  	bitmap->end = end;
  	bitmap->real_end = real_end;
  	bitmap->base_error_code = EXT2_ET_BAD_GENERIC_MARK;
  	if (descr) {
  		retval = ext2fs_get_mem(strlen(descr)+1,
  					(void **) &bitmap->description);
  		if (retval) {
  			ext2fs_free_mem((void **) &bitmap);
  			return retval;
  		}
  		strcpy(bitmap->description, descr);
  	} else
  		bitmap->description = 0;
  
  	size = (size_t) (((bitmap->real_end - bitmap->start) / 8) + 1);
  	retval = ext2fs_get_mem(size, (void **) &bitmap->bitmap);
  	if (retval) {
  		ext2fs_free_mem((void **) &bitmap->description);
  		ext2fs_free_mem((void **) &bitmap);
  		return retval;
  	}
  
  	if (init_map)
  		memcpy(bitmap->bitmap, init_map, size);
  	else
  		memset(bitmap->bitmap, 0, size);
  	*ret = bitmap;
  	return 0;
  }
  
  errcode_t ext2fs_allocate_generic_bitmap(__u32 start,
  					 __u32 end,
  					 __u32 real_end,
  					 const char *descr,
  					 ext2fs_generic_bitmap *ret)
  {
  	return make_bitmap(start, end, real_end, descr, 0, ret);
  }
  
  errcode_t ext2fs_copy_bitmap(ext2fs_generic_bitmap src,
  			     ext2fs_generic_bitmap *dest)
  {
  	errcode_t		retval;
  	ext2fs_generic_bitmap	new_map;
  
  	retval = make_bitmap(src->start, src->end, src->real_end,
  			     src->description, src->bitmap, &new_map);
  	if (retval)
  		return retval;
  	new_map->magic = src->magic;
  	new_map->fs = src->fs;
  	new_map->base_error_code = src->base_error_code;
  	*dest = new_map;
  	return 0;
  }
  
  void ext2fs_set_bitmap_padding(ext2fs_generic_bitmap map)
  {
  	__u32	i, j;
  
  	for (i=map->end+1, j = i - map->start; i <= map->real_end; i++, j++)
  		ext2fs_set_bit(j, map->bitmap);
  
  	return;
  }	
  
  errcode_t ext2fs_allocate_inode_bitmap(ext2_filsys fs,
  				       const char *descr,
  				       ext2fs_inode_bitmap *ret)
  {
  	ext2fs_inode_bitmap bitmap;
  	errcode_t	retval;
  	__u32		start, end, real_end;
  
  	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
  
  	fs->write_bitmaps = ext2fs_write_bitmaps;
  
  	start = 1;
  	end = fs->super->s_inodes_count;
  	real_end = (EXT2_INODES_PER_GROUP(fs->super) * fs->group_desc_count);
  
  	retval = ext2fs_allocate_generic_bitmap(start, end, real_end,
  						descr, &bitmap);
  	if (retval)
  		return retval;
  	
  	bitmap->magic = EXT2_ET_MAGIC_INODE_BITMAP;
  	bitmap->fs = fs;
  	bitmap->base_error_code = EXT2_ET_BAD_INODE_MARK;
  	
  	*ret = bitmap;
  	return 0;
  }
  
  errcode_t ext2fs_allocate_block_bitmap(ext2_filsys fs,
  				       const char *descr,
  				       ext2fs_block_bitmap *ret)
  {
  	ext2fs_block_bitmap bitmap;
  	errcode_t	retval;
  	__u32		start, end, real_end;
  
  	EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
  
  	fs->write_bitmaps = ext2fs_write_bitmaps;
  
  	start = fs->super->s_first_data_block;
  	end = fs->super->s_blocks_count-1;
  	real_end = (EXT2_BLOCKS_PER_GROUP(fs->super)  
  		    * fs->group_desc_count)-1 + start;
  	
  	retval = ext2fs_allocate_generic_bitmap(start, end, real_end,
  						descr, &bitmap);
  	if (retval)
  		return retval;
  
  	bitmap->magic = EXT2_ET_MAGIC_BLOCK_BITMAP;
  	bitmap->fs = fs;
  	bitmap->base_error_code = EXT2_ET_BAD_BLOCK_MARK;
  	
  	*ret = bitmap;
  	return 0;
  }
  
  errcode_t ext2fs_fudge_inode_bitmap_end(ext2fs_inode_bitmap bitmap,
  					ext2_ino_t end, ext2_ino_t *oend)
  {
  	EXT2_CHECK_MAGIC(bitmap, EXT2_ET_MAGIC_INODE_BITMAP);
  	
  	if (end > bitmap->real_end)
  		return EXT2_ET_FUDGE_INODE_BITMAP_END;
  	if (oend)
  		*oend = bitmap->end;
  	bitmap->end = end;
  	return 0;
  }
  
  errcode_t ext2fs_fudge_block_bitmap_end(ext2fs_block_bitmap bitmap,
  					blk_t end, blk_t *oend)
  {
  	EXT2_CHECK_MAGIC(bitmap, EXT2_ET_MAGIC_BLOCK_BITMAP);
  	
  	if (end > bitmap->real_end)
  		return EXT2_ET_FUDGE_BLOCK_BITMAP_END;
  	if (oend)
  		*oend = bitmap->end;
  	bitmap->end = end;
  	return 0;
  }
  
  void ext2fs_clear_inode_bitmap(ext2fs_inode_bitmap bitmap)
  {
  	if (!bitmap || (bitmap->magic != EXT2_ET_MAGIC_INODE_BITMAP))
  		return;
  
  	memset(bitmap->bitmap, 0,
  	       (size_t) (((bitmap->real_end - bitmap->start) / 8) + 1));
  }
  
  void ext2fs_clear_block_bitmap(ext2fs_block_bitmap bitmap)
  {
  	if (!bitmap || (bitmap->magic != EXT2_ET_MAGIC_BLOCK_BITMAP))
  		return;
  
  	memset(bitmap->bitmap, 0,
  	       (size_t) (((bitmap->real_end - bitmap->start) / 8) + 1));
  }
  