lib/ext2fs/alloc_tables.c

   1 /*
   2  * alloc_tables.c --- Allocate tables for a newly initialized
   3  * filesystem.  Used by mke2fs when initializing a filesystem
   4  *
   5  * Copyright (C) 1996 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 errcode_t ext2fs_allocate_group_table(ext2_filsys fs, dgrp_t group,
  31                                       ext2fs_block_bitmap bmap)
  32 {
  33         errcode_t       retval;
  34         blk_t           group_blk, start_blk, last_blk, new_blk, blk;
  35         int             j;
  36
  37         group_blk = fs->super->s_first_data_block +
  38                 (group * fs->super->s_blocks_per_group);
  39
  40         last_blk = group_blk + fs->super->s_blocks_per_group;
  41         if (last_blk >= fs->super->s_blocks_count)
  42                 last_blk = fs->super->s_blocks_count - 1;
  43
  44         if (!bmap)
  45                 bmap = fs->block_map;
  46
  47         /*
  48          * Allocate the block and inode bitmaps, if necessary
  49          */
  50         if (fs->stride) {
  51                 start_blk = group_blk + fs->inode_blocks_per_group;
  52                 start_blk += ((fs->stride * group) %
  53                               (last_blk - start_blk));
  54                 if (start_blk > last_blk)
  55                         start_blk = group_blk;
  56         } else
  57                 start_blk = group_blk;
  58
  59         if (!fs->group_desc[group].bg_block_bitmap) {
  60                 retval = ext2fs_get_free_blocks(fs, start_blk, last_blk,
  61                                                 1, bmap, &new_blk);
  62                 if (retval == EXT2_ET_BLOCK_ALLOC_FAIL)
  63                         retval = ext2fs_get_free_blocks(fs, group_blk,
  64                                         last_blk, 1, bmap, &new_blk);
  65                 if (retval)
  66                         return retval;
  67                 ext2fs_mark_block_bitmap(bmap, new_blk);
  68                 fs->group_desc[group].bg_block_bitmap = new_blk;
  69         }
  70
  71         if (!fs->group_desc[group].bg_inode_bitmap) {
  72                 retval = ext2fs_get_free_blocks(fs, start_blk, last_blk,
  73                                                 1, bmap, &new_blk);
  74                 if (retval == EXT2_ET_BLOCK_ALLOC_FAIL)
  75                         retval = ext2fs_get_free_blocks(fs, group_blk,
  76                                         last_blk, 1, bmap, &new_blk);
  77                 if (retval)
  78                         return retval;
  79                 ext2fs_mark_block_bitmap(bmap, new_blk);
  80                 fs->group_desc[group].bg_inode_bitmap = new_blk;
  81         }
  82
  83         /*
  84          * Allocate the inode table
  85          */
  86         if (!fs->group_desc[group].bg_inode_table) {
  87                 retval = ext2fs_get_free_blocks(fs, group_blk, last_blk,
  88                                                 fs->inode_blocks_per_group,
  89                                                 bmap, &new_blk);
  90                 if (retval)
  91                         return retval;
  92                 for (j=0, blk = new_blk;
  93                      j < fs->inode_blocks_per_group;
  94                      j++, blk++)
  95                         ext2fs_mark_block_bitmap(bmap, blk);
  96                 fs->group_desc[group].bg_inode_table = new_blk;
  97         }
  98
  99
 100         return 0;
 101 }
 102
 103
 104
 105 errcode_t ext2fs_allocate_tables(ext2_filsys fs)
 106 {
 107         errcode_t       retval;
 108         dgrp_t          i;
 109
 110         for (i = 0; i < fs->group_desc_count; i++) {
 111                 retval = ext2fs_allocate_group_table(fs, i, fs->block_map);
 112                 if (retval)
 113                         return retval;
 114         }
 115         return 0;
 116 }
 117