release/src/router/busybox/e2fsprogs/ext2fs/alloc_sb.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * alloc_sb.c --- Allocate the superblock and block group descriptors for a
   4  * newly initialized filesystem.  Used by mke2fs when initializing a filesystem
   5  *
   6  * Copyright (C) 1994, 1995, 1996, 2003 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 #include <fcntl.h>
  20 #include <time.h>
  21 #if HAVE_SYS_STAT_H
  22 #include <sys/stat.h>
  23 #endif
  24 #if HAVE_SYS_TYPES_H
  25 #include <sys/types.h>
  26 #endif
  27
  28 #include "ext2_fs.h"
  29 #include "ext2fs.h"
  30
  31 int ext2fs_reserve_super_and_bgd(ext2_filsys fs,
  32                                  dgrp_t group,
  33                                  ext2fs_block_bitmap bmap)
  34 {
  35         blk_t   super_blk, old_desc_blk, new_desc_blk;
  36         int     j, old_desc_blocks, num_blocks;
  37
  38         num_blocks = ext2fs_super_and_bgd_loc(fs, group, &super_blk,
  39                                               &old_desc_blk, &new_desc_blk, 0);
  40
  41         if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
  42                 old_desc_blocks = fs->super->s_first_meta_bg;
  43         else
  44                 old_desc_blocks =
  45                         fs->desc_blocks + fs->super->s_reserved_gdt_blocks;
  46
  47         if (super_blk || (group == 0))
  48                 ext2fs_mark_block_bitmap(bmap, super_blk);
  49
  50         if (old_desc_blk) {
  51                 for (j=0; j < old_desc_blocks; j++)
  52                         ext2fs_mark_block_bitmap(bmap, old_desc_blk + j);
  53         }
  54         if (new_desc_blk)
  55                 ext2fs_mark_block_bitmap(bmap, new_desc_blk);
  56
  57         return num_blocks;
  58 }