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

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