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 #if EXT2_FLAT_INCLUDES
  28 #include "ext2_fs.h"
  29 #else
  30 #include <linux/ext2_fs.h>
  31 #endif
  32
  33 #include "ext2fs.h"
  34
  35 errcode_t ext2fs_allocate_group_table(ext2_filsys fs, int group,
  36                                       ext2fs_block_bitmap bmap)
  37 {
  38         errcode_t       retval;
  39         blk_t           group_blk, start_blk, last_blk, new_blk, blk;
  40         int             j;
  41
  42         group_blk = fs->super->s_first_data_block +
  43                 (group * fs->super->s_blocks_per_group);
  44
  45         last_blk = group_blk + fs->super->s_blocks_per_group;
  46         if (last_blk >= fs->super->s_blocks_count)
  47                 last_blk = fs->super->s_blocks_count - 1;
  48
  49         start_blk = group_blk + 3 + fs->desc_blocks;
  50         if (start_blk > last_blk)
  51                 start_blk = group_blk;
  52
  53         if (!bmap)
  54                 bmap = fs->block_map;
  55
  56         /*
  57          * Allocate the inode table
  58          */
  59         if (!fs->group_desc[group].bg_inode_table) {
  60                 retval = ext2fs_get_free_blocks(fs, start_blk, last_blk,
  61                                                 fs->inode_blocks_per_group,
  62                                                 bmap, &new_blk);
  63                 if (retval)
  64                         return retval;
  65                 for (j=0, blk = new_blk;
  66                      j < fs->inode_blocks_per_group;
  67                      j++, blk++)
  68                         ext2fs_mark_block_bitmap(bmap, blk);
  69                 fs->group_desc[group].bg_inode_table = new_blk;
  70         }
  71
  72         /*
  73          * Allocate the block and inode bitmaps, if necessary
  74          */
  75         if (fs->stride) {
  76                 start_blk += fs->inode_blocks_per_group;
  77                 start_blk += ((fs->stride * group) %
  78                               (last_blk - start_blk));
  79                 if (start_blk > last_blk)
  80                         /* should never happen */
  81                         start_blk = group_blk;
  82         } else
  83                 start_blk = group_blk;
  84
  85         if (!fs->group_desc[group].bg_block_bitmap) {
  86                 retval = ext2fs_get_free_blocks(fs, start_blk, last_blk,
  87                                                 1, bmap, &new_blk);
  88                 if (retval == EXT2_ET_BLOCK_ALLOC_FAIL)
  89                         retval = ext2fs_get_free_blocks(fs, group_blk,
  90                                         last_blk, 1, bmap, &new_blk);
  91                 if (retval)
  92                         return retval;
  93                 ext2fs_mark_block_bitmap(bmap, new_blk);
  94                 fs->group_desc[group].bg_block_bitmap = new_blk;
  95         }
  96
  97         if (!fs->group_desc[group].bg_inode_bitmap) {
  98                 retval = ext2fs_get_free_blocks(fs, start_blk, last_blk,
  99                                                 1, bmap, &new_blk);
 100                 if (retval == EXT2_ET_BLOCK_ALLOC_FAIL)
 101                         retval = ext2fs_get_free_blocks(fs, group_blk,
 102                                         last_blk, 1, bmap, &new_blk);
 103                 if (retval)
 104                         return retval;
 105                 ext2fs_mark_block_bitmap(bmap, new_blk);
 106                 fs->group_desc[group].bg_inode_bitmap = new_blk;
 107         }
 108         return 0;
 109 }
 110
 111
 112
 113 errcode_t ext2fs_allocate_tables(ext2_filsys fs)
 114 {
 115         errcode_t       retval;
 116         int             i;
 117
 118         for (i = 0; i < fs->group_desc_count; i++) {
 119                 retval = ext2fs_allocate_group_table(fs, i, fs->block_map);
 120                 if (retval)
 121                         return retval;
 122         }
 123         return 0;
 124 }
 125