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 Library
   9  * General Public License, version 2.
  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 #include "ext2fsP.h"
  30
  31 /*
  32  * This routine searches for free blocks that can allocate a full
  33  * group of bitmaps or inode tables for a flexbg group.  Returns the
  34  * block number with a correct offset were the bitmaps and inode
  35  * tables can be allocated continously and in order.
  36  */
  37 static blk64_t flexbg_offset(ext2_filsys fs, dgrp_t group, blk64_t start_blk,
  38                              ext2fs_block_bitmap bmap, int rem_grp,
  39                              int elem_size)
  40 {
  41         int             flexbg, flexbg_size, size;
  42         blk64_t         last_blk, first_free = 0;
  43         dgrp_t          last_grp;
  44
  45         size = rem_grp * elem_size;
  46
  47         if (size > (int) (fs->super->s_blocks_per_group / 8))
  48                 size = (int) fs->super->s_blocks_per_group / 8;
  49
  50         /*
  51          * Don't do a long search if the previous block
  52          * search is still valid.
  53          */
  54         if (start_blk && ext2fs_test_block_bitmap_range2(bmap, start_blk,
  55                                                          elem_size))
  56                 return start_blk;
  57
  58         start_blk = ext2fs_group_first_block2(fs, flexbg_size * flexbg);
  59         last_grp = group | (flexbg_size - 1);
  60         if (last_grp > fs->group_desc_count-1)
  61                 last_grp = fs->group_desc_count-1;
  62         last_blk = ext2fs_group_last_block2(fs, last_grp);
  63
  64         /* Find the first available block */
  65         if (ext2fs_get_free_blocks2(fs, start_blk, last_blk, size,
  66                                     bmap, &first_free) == 0)
  67                 return first_free;
  68
  69         if (ext2fs_get_free_blocks2(fs, start_blk, last_blk, elem_size,
  70                                    bmap, &first_free) == 0)
  71                 return first_free;
  72
  73         if (ext2fs_get_free_blocks2(fs, 0, last_blk, elem_size, bmap,
  74                                     &first_free) == 0)
  75                 return first_free;
  76
  77         return first_free;
  78 }
  79
  80 errcode_t ext2fs_allocate_group_table(ext2_filsys fs, dgrp_t group,
  81                                       ext2fs_block_bitmap bmap)
  82 {
  83         errcode_t       retval;
  84         blk64_t         group_blk, start_blk, last_blk, new_blk, blk;
  85         dgrp_t          last_grp = 0;
  86         int             j, rem_grps = 0, flexbg_size = 0;
  87
  88         group_blk = ext2fs_group_first_block2(fs, group);
  89         last_blk = ext2fs_group_last_block2(fs, group);
  90
  91         if (!bmap)
  92                 bmap = fs->block_map;
  93
  94         if (EXT2_HAS_INCOMPAT_FEATURE(fs->super,
  95                                       EXT4_FEATURE_INCOMPAT_FLEX_BG) &&
  96             fs->super->s_log_groups_per_flex) {
  97                 flexbg_size = 1 << fs->super->s_log_groups_per_flex;
  98                 last_grp = group | (flexbg_size - 1);
  99                 if (last_grp > fs->group_desc_count-1)
 100                         last_grp = fs->group_desc_count-1;
 101                 rem_grps = last_grp - group + 1;
 102         }
 103
 104         /*
 105          * Allocate the block and inode bitmaps, if necessary
 106          */
 107         if (fs->stride) {
 108                 retval = ext2fs_get_free_blocks2(fs, group_blk, last_blk,
 109                                                  1, bmap, &start_blk);
 110                 if (retval)
 111                         return retval;
 112                 start_blk += fs->inode_blocks_per_group;
 113                 start_blk += ((fs->stride * group) %
 114                               (last_blk - start_blk + 1));
 115                 if (start_blk >= last_blk)
 116                         start_blk = group_blk;
 117         } else
 118                 start_blk = group_blk;
 119
 120         if (flexbg_size) {
 121                 blk64_t prev_block = 0;
 122
 123                 if (group % flexbg_size)
 124                         prev_block = ext2fs_block_bitmap_loc(fs, group - 1) + 1;
 125                 start_blk = flexbg_offset(fs, group, prev_block, bmap,
 126                                           rem_grps, 1);
 127                 last_blk = ext2fs_group_last_block2(fs, last_grp);
 128         }
 129
 130         if (!ext2fs_block_bitmap_loc(fs, group)) {
 131                 retval = ext2fs_get_free_blocks2(fs, start_blk, last_blk,
 132                                                  1, bmap, &new_blk);
 133                 if (retval == EXT2_ET_BLOCK_ALLOC_FAIL)
 134                         retval = ext2fs_get_free_blocks2(fs, group_blk,
 135                                         last_blk, 1, bmap, &new_blk);
 136                 if (retval)
 137                         return retval;
 138                 ext2fs_mark_block_bitmap2(bmap, new_blk);
 139                 ext2fs_block_bitmap_loc_set(fs, group, new_blk);
 140                 if (flexbg_size) {
 141                         dgrp_t gr = ext2fs_group_of_blk2(fs, new_blk);
 142                         ext2fs_bg_free_blocks_count_set(fs, gr, ext2fs_bg_free_blocks_count(fs, gr) - 1);
 143                         ext2fs_free_blocks_count_add(fs->super, -1);
 144                         ext2fs_bg_flags_clear(fs, gr, EXT2_BG_BLOCK_UNINIT);
 145                         ext2fs_group_desc_csum_set(fs, gr);
 146                 }
 147         }
 148
 149         if (flexbg_size) {
 150                 blk64_t prev_block = 0;
 151                 if (group % flexbg_size)
 152                         prev_block = ext2fs_inode_bitmap_loc(fs, group - 1) + 1;
 153                 else
 154                         prev_block = ext2fs_block_bitmap_loc(fs, group) +
 155                                 flexbg_size;
 156                 start_blk = flexbg_offset(fs, group, prev_block, bmap,
 157                                           rem_grps, 1);
 158                 last_blk = ext2fs_group_last_block2(fs, last_grp);
 159         }
 160
 161         if (!ext2fs_inode_bitmap_loc(fs, group)) {
 162                 retval = ext2fs_get_free_blocks2(fs, start_blk, last_blk,
 163                                                  1, bmap, &new_blk);
 164                 if (retval == EXT2_ET_BLOCK_ALLOC_FAIL)
 165                         retval = ext2fs_get_free_blocks2(fs, group_blk,
 166                                          last_blk, 1, bmap, &new_blk);
 167                 if (retval)
 168                         return retval;
 169                 ext2fs_mark_block_bitmap2(bmap, new_blk);
 170                 ext2fs_inode_bitmap_loc_set(fs, group, new_blk);
 171                 if (flexbg_size) {
 172                         dgrp_t gr = ext2fs_group_of_blk2(fs, new_blk);
 173                         ext2fs_bg_free_blocks_count_set(fs, gr, ext2fs_bg_free_blocks_count(fs, gr) - 1);
 174                         ext2fs_free_blocks_count_add(fs->super, -1);
 175                         ext2fs_bg_flags_clear(fs, gr, EXT2_BG_BLOCK_UNINIT);
 176                         ext2fs_group_desc_csum_set(fs, gr);
 177                 }
 178         }
 179
 180         /*
 181          * Allocate the inode table
 182          */
 183         if (flexbg_size) {
 184                 blk64_t prev_block = 0;
 185
 186                 if (group % flexbg_size)
 187                         prev_block = ext2fs_inode_table_loc(fs, group - 1) +
 188                                 fs->inode_blocks_per_group;
 189                 else
 190                         prev_block = ext2fs_inode_bitmap_loc(fs, group) +
 191                                 flexbg_size;
 192
 193                 group_blk = flexbg_offset(fs, group, prev_block, bmap,
 194                                           rem_grps, fs->inode_blocks_per_group);
 195                 last_blk = ext2fs_group_last_block2(fs, last_grp);
 196         }
 197
 198         if (!ext2fs_inode_table_loc(fs, group)) {
 199                 retval = ext2fs_get_free_blocks2(fs, group_blk, last_blk,
 200                                                 fs->inode_blocks_per_group,
 201                                                 bmap, &new_blk);
 202                 if (retval)
 203                         return retval;
 204                 for (j=0, blk = new_blk;
 205                      j < fs->inode_blocks_per_group;
 206                      j++, blk++) {
 207                         ext2fs_mark_block_bitmap2(bmap, blk);
 208                         if (flexbg_size) {
 209                                 dgrp_t gr = ext2fs_group_of_blk2(fs, blk);
 210                                 ext2fs_bg_free_blocks_count_set(fs, gr, ext2fs_bg_free_blocks_count(fs, gr) - 1);
 211                                 ext2fs_free_blocks_count_add(fs->super, -1);
 212                                 ext2fs_bg_flags_clear(fs, gr,
 213                                                      EXT2_BG_BLOCK_UNINIT);
 214                                 ext2fs_group_desc_csum_set(fs, gr);
 215                         }
 216                 }
 217                 ext2fs_inode_table_loc_set(fs, group, new_blk);
 218         }
 219         ext2fs_group_desc_csum_set(fs, group);
 220         return 0;
 221 }
 222
 223 errcode_t ext2fs_allocate_tables(ext2_filsys fs)
 224 {
 225         errcode_t       retval;
 226         dgrp_t          i;
 227         struct ext2fs_numeric_progress_struct progress;
 228
 229         ext2fs_numeric_progress_init(fs, &progress, NULL,
 230                                      fs->group_desc_count);
 231
 232         for (i = 0; i < fs->group_desc_count; i++) {
 233                 ext2fs_numeric_progress_update(fs, &progress, i);
 234                 retval = ext2fs_allocate_group_table(fs, i, fs->block_map);
 235                 if (retval)
 236                         return retval;
 237         }
 238         ext2fs_numeric_progress_close(fs, &progress, NULL);
 239         return 0;
 240 }
 241