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 "config.h"
  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 #include "ext2fsP.h"
  31
  32 /*
  33  * This routine searches for free blocks that can allocate a full
  34  * group of bitmaps or inode tables for a flexbg group.  Returns the
  35  * block number with a correct offset were the bitmaps and inode
  36  * tables can be allocated continously and in order.
  37  */
  38 static blk64_t flexbg_offset(ext2_filsys fs, dgrp_t group, blk64_t start_blk,
  39                              ext2fs_block_bitmap bmap, int rem_grp,
  40                              int elem_size)
  41 {
  42         int             flexbg, flexbg_size, size;
  43         blk64_t         last_blk, first_free = 0;
  44         dgrp_t          last_grp;
  45
  46         flexbg_size = 1 << fs->super->s_log_groups_per_flex;
  47         flexbg = group / flexbg_size;
  48         size = rem_grp * elem_size;
  49
  50         if (size > (int) (fs->super->s_blocks_per_group / 4))
  51                 size = (int) fs->super->s_blocks_per_group / 4;
  52
  53         /*
  54          * Don't do a long search if the previous block search is still valid,
  55          * but skip minor obstructions such as group descriptor backups.
  56          */
  57         if (start_blk && start_blk < ext2fs_blocks_count(fs->super) &&
  58             ext2fs_get_free_blocks2(fs, start_blk, start_blk + size, elem_size,
  59                                     bmap, &first_free) == 0)
  60                 return first_free;
  61
  62         start_blk = ext2fs_group_first_block2(fs, flexbg_size * flexbg);
  63         last_grp = group | (flexbg_size - 1);
  64         if (last_grp > fs->group_desc_count-1)
  65                 last_grp = fs->group_desc_count-1;
  66         last_blk = ext2fs_group_last_block2(fs, last_grp);
  67
  68         /* Find the first available block */
  69         if (ext2fs_get_free_blocks2(fs, start_blk, last_blk, size,
  70                                     bmap, &first_free) == 0)
  71                 return first_free;
  72
  73         if (ext2fs_get_free_blocks2(fs, start_blk, last_blk, elem_size,
  74                                    bmap, &first_free) == 0)
  75                 return first_free;
  76
  77         if (ext2fs_get_free_blocks2(fs, 0, last_blk, elem_size, bmap,
  78                                     &first_free) == 0)
  79                 return first_free;
  80
  81         return first_free;
  82 }
  83
  84 errcode_t ext2fs_allocate_group_table(ext2_filsys fs, dgrp_t group,
  85                                       ext2fs_block_bitmap bmap)
  86 {
  87         errcode_t       retval;
  88         blk64_t         group_blk, start_blk, last_blk, new_blk;
  89         dgrp_t          last_grp = 0;
  90         int             rem_grps = 0, flexbg_size = 0, table_offset = 0;
  91
  92         group_blk = ext2fs_group_first_block2(fs, group);
  93         last_blk = ext2fs_group_last_block2(fs, group);
  94
  95         if (!bmap)
  96                 bmap = fs->block_map;
  97
  98         if (EXT2_HAS_INCOMPAT_FEATURE(fs->super,
  99                                       EXT4_FEATURE_INCOMPAT_FLEX_BG) &&
 100             fs->super->s_log_groups_per_flex) {
 101                 flexbg_size = 1 << fs->super->s_log_groups_per_flex;
 102                 last_grp = group | (flexbg_size - 1);
 103                 if (last_grp > fs->group_desc_count-1)
 104                         last_grp = fs->group_desc_count-1;
 105                 rem_grps = last_grp - group + 1;
 106         }
 107
 108         /*
 109          * Allocate the block and inode bitmaps, if necessary
 110          */
 111         if (fs->stride) {
 112                 retval = ext2fs_get_free_blocks2(fs, group_blk, last_blk,
 113                                                  1, bmap, &start_blk);
 114                 if (retval)
 115                         return retval;
 116                 start_blk += fs->inode_blocks_per_group;
 117                 start_blk += ((fs->stride * group) %
 118                               (last_blk - start_blk + 1));
 119                 if (start_blk >= last_blk)
 120                         start_blk = group_blk;
 121         } else
 122                 start_blk = group_blk;
 123
 124         if (flexbg_size) {
 125                 blk64_t prev_block = 0;
 126
 127                 table_offset = flexbg_size;
 128                 if (group % flexbg_size)
 129                         prev_block = ext2fs_block_bitmap_loc(fs, group - 1) + 1;
 130                 else if (last_grp == fs->group_desc_count-1) {
 131                         /*
 132                          * If we are allocating for the last flex_bg
 133                          * keep the metadata tables contiguous
 134                          */
 135                         table_offset = last_grp & (flexbg_size - 1);
 136                         if (table_offset == 0)
 137                                 table_offset = flexbg_size;
 138                         else
 139                                 table_offset++;
 140                 }
 141                 /* FIXME: Take backup group descriptor blocks into account
 142                  * if the flexbg allocations will grow to overlap them... */
 143                 start_blk = flexbg_offset(fs, group, prev_block, bmap,
 144                                           rem_grps, 1);
 145                 last_blk = ext2fs_group_last_block2(fs, last_grp);
 146         }
 147
 148         if (!ext2fs_block_bitmap_loc(fs, group)) {
 149                 retval = ext2fs_get_free_blocks2(fs, start_blk, last_blk,
 150                                                  1, bmap, &new_blk);
 151                 if (retval == EXT2_ET_BLOCK_ALLOC_FAIL)
 152                         retval = ext2fs_get_free_blocks2(fs, group_blk,
 153                                         last_blk, 1, bmap, &new_blk);
 154                 if (retval)
 155                         return retval;
 156                 ext2fs_mark_block_bitmap2(bmap, new_blk);
 157                 ext2fs_block_bitmap_loc_set(fs, group, new_blk);
 158                 if (flexbg_size) {
 159                         dgrp_t gr = ext2fs_group_of_blk2(fs, new_blk);
 160                         ext2fs_bg_free_blocks_count_set(fs, gr, ext2fs_bg_free_blocks_count(fs, gr) - 1);
 161                         ext2fs_free_blocks_count_add(fs->super, -1);
 162                         ext2fs_bg_flags_clear(fs, gr, EXT2_BG_BLOCK_UNINIT);
 163                         ext2fs_group_desc_csum_set(fs, gr);
 164                 }
 165         }
 166
 167         if (flexbg_size) {
 168                 blk64_t prev_block = 0;
 169                 if (group % flexbg_size)
 170                         prev_block = ext2fs_inode_bitmap_loc(fs, group - 1) + 1;
 171                 else
 172                         prev_block = ext2fs_block_bitmap_loc(fs, group) +
 173                                 table_offset;
 174                 /* FIXME: Take backup group descriptor blocks into account
 175                  * if the flexbg allocations will grow to overlap them... */
 176                 start_blk = flexbg_offset(fs, group, prev_block, bmap,
 177                                           rem_grps, 1);
 178                 last_blk = ext2fs_group_last_block2(fs, last_grp);
 179         }
 180
 181         if (!ext2fs_inode_bitmap_loc(fs, group)) {
 182                 retval = ext2fs_get_free_blocks2(fs, start_blk, last_blk,
 183                                                  1, bmap, &new_blk);
 184                 if (retval == EXT2_ET_BLOCK_ALLOC_FAIL)
 185                         retval = ext2fs_get_free_blocks2(fs, group_blk,
 186                                          last_blk, 1, bmap, &new_blk);
 187                 if (retval)
 188                         return retval;
 189                 ext2fs_mark_block_bitmap2(bmap, new_blk);
 190                 ext2fs_inode_bitmap_loc_set(fs, group, new_blk);
 191                 if (flexbg_size) {
 192                         dgrp_t gr = ext2fs_group_of_blk2(fs, new_blk);
 193                         ext2fs_bg_free_blocks_count_set(fs, gr, ext2fs_bg_free_blocks_count(fs, gr) - 1);
 194                         ext2fs_free_blocks_count_add(fs->super, -1);
 195                         ext2fs_bg_flags_clear(fs, gr, EXT2_BG_BLOCK_UNINIT);
 196                         ext2fs_group_desc_csum_set(fs, gr);
 197                 }
 198         }
 199
 200         /*
 201          * Allocate the inode table
 202          */
 203         if (flexbg_size) {
 204                 blk64_t prev_block = 0;
 205
 206                 if (group % flexbg_size)
 207                         prev_block = ext2fs_inode_table_loc(fs, group - 1) +
 208                                 fs->inode_blocks_per_group;
 209                 else
 210                         prev_block = ext2fs_inode_bitmap_loc(fs, group) +
 211                                 table_offset;
 212
 213                 /* FIXME: Take backup group descriptor blocks into account
 214                  * if the flexbg allocations will grow to overlap them... */
 215                 group_blk = flexbg_offset(fs, group, prev_block, bmap,
 216                                           rem_grps, fs->inode_blocks_per_group);
 217                 last_blk = ext2fs_group_last_block2(fs, last_grp);
 218         }
 219
 220         if (!ext2fs_inode_table_loc(fs, group)) {
 221                 retval = ext2fs_get_free_blocks2(fs, group_blk, last_blk,
 222                                                 fs->inode_blocks_per_group,
 223                                                 bmap, &new_blk);
 224                 if (retval)
 225                         return retval;
 226                 if (flexbg_size)
 227                         ext2fs_block_alloc_stats_range(fs, new_blk,
 228                                        fs->inode_blocks_per_group, +1);
 229                 else
 230                         ext2fs_mark_block_bitmap_range2(fs->block_map,
 231                                         new_blk, fs->inode_blocks_per_group);
 232                 ext2fs_inode_table_loc_set(fs, group, new_blk);
 233         }
 234         ext2fs_group_desc_csum_set(fs, group);
 235         return 0;
 236 }
 237
 238 errcode_t ext2fs_allocate_tables(ext2_filsys fs)
 239 {
 240         errcode_t       retval;
 241         dgrp_t          i;
 242         struct ext2fs_numeric_progress_struct progress;
 243
 244         ext2fs_numeric_progress_init(fs, &progress, NULL,
 245                                      fs->group_desc_count);
 246
 247         for (i = 0; i < fs->group_desc_count; i++) {
 248                 ext2fs_numeric_progress_update(fs, &progress, i);
 249                 retval = ext2fs_allocate_group_table(fs, i, fs->block_map);
 250                 if (retval)
 251                         return retval;
 252         }
 253         ext2fs_numeric_progress_close(fs, &progress, NULL);
 254         return 0;
 255 }
 256