sdk/lib/fslib/ext2lib/Group.c

   1 /*
   2  * PROJECT:          Mke2fs
   3  * FILE:             Group.c
   4  * PROGRAMMER:       Matt Wu <mattwu@163.com>
   5  * HOMEPAGE:         http://ext2.yeah.net
   6  */
   7
   8 /* INCLUDES **************************************************************/
   9
  10 #include "Mke2fs.h"
  11
  12 /* DEFINITIONS ***********************************************************/
  13
  14 /* FUNCTIONS *************************************************************/
  15
  16 int test_root(int a, int b)
  17 {
  18     if (a == 0)
  19         return 1;
  20     while (1)
  21     {
  22         if (a == 1)
  23             return 1;
  24         if (a % b)
  25             return 0;
  26         a = a / b;
  27     }
  28 }
  29
  30 bool ext2_bg_has_super(PEXT2_SUPER_BLOCK pExt2Sb, int group_block)
  31 {
  32     if (!(pExt2Sb->s_feature_ro_compat & EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER))
  33         return true;
  34
  35     if (test_root(group_block, 3) || (test_root(group_block, 5)) ||
  36         test_root(group_block, 7))
  37         return true;
  38
  39     return false;
  40 }
  41
  42
  43 bool ext2_allocate_group_desc(PEXT2_FILESYS Ext2Sys)
  44 {
  45     ULONG size;
  46
  47     size = Ext2Sys->desc_blocks * Ext2Sys->blocksize;
  48
  49     Ext2Sys->group_desc =
  50         (PEXT2_GROUP_DESC)RtlAllocateHeap(RtlGetProcessHeap(), 0, size);
  51
  52     if (Ext2Sys->group_desc)
  53     {
  54         memset(Ext2Sys->group_desc, 0, size);
  55         return true;
  56     }
  57
  58     return false;
  59 }
  60
  61 void ext2_free_group_desc(PEXT2_FILESYS Ext2Sys)
  62 {
  63     if (Ext2Sys->group_desc)
  64     {
  65         RtlFreeHeap(RtlGetProcessHeap(), 0, Ext2Sys->group_desc);
  66         Ext2Sys->group_desc = NULL;
  67     }
  68 }