lib/ext2fs/alloc_sb.c

   1 /*
   2  * alloc_sb.c --- Allocate the superblock and block group descriptors for a
   3  * newly initialized filesystem.  Used by mke2fs when initializing a filesystem
   4  *
   5  * Copyright (C) 1994, 1995, 1996, 2003 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 #include <fcntl.h>
  19 #include <time.h>
  20 #if HAVE_SYS_STAT_H
  21 #include <sys/stat.h>
  22 #endif
  23 #if HAVE_SYS_TYPES_H
  24 #include <sys/types.h>
  25 #endif
  26
  27 #include "ext2_fs.h"
  28 #include "ext2fs.h"
  29
  30 int ext2fs_reserve_super_and_bgd(ext2_filsys fs,
  31                                  dgrp_t group,
  32                                  ext2fs_block_bitmap bmap)
  33 {
  34         blk_t   super_blk, old_desc_blk, new_desc_blk;
  35         int     j, old_desc_blocks, num_blocks;
  36
  37         num_blocks = ext2fs_super_and_bgd_loc(fs, group, &super_blk,
  38                                               &old_desc_blk, &new_desc_blk, 0);
  39
  40         if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
  41                 old_desc_blocks = fs->super->s_first_meta_bg;
  42         else
  43                 old_desc_blocks = fs->desc_blocks;
  44
  45         if (super_blk || (group == 0))
  46                 ext2fs_mark_block_bitmap(bmap, super_blk);
  47
  48         if (old_desc_blk) {
  49                 for (j=0; j < old_desc_blocks; j++)
  50                         ext2fs_mark_block_bitmap(bmap, old_desc_blk + j);
  51         }
  52         if (new_desc_blk)
  53                 ext2fs_mark_block_bitmap(bmap, new_desc_blk);
  54
  55         return num_blocks;
  56 }