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 continuously 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 (ext2fs_has_feature_flex_bg(fs->super) &&
  99             fs->super->s_log_groups_per_flex) {
 100                 flexbg_size = 1 << fs->super->s_log_groups_per_flex;
 101                 last_grp = group | (flexbg_size - 1);
 102                 if (last_grp > fs->group_desc_count-1)
 103                         last_grp = fs->group_desc_count-1;
 104                 rem_grps = last_grp - group + 1;
 105         }
 106
 107         /*
 108          * Allocate the block and inode bitmaps, if necessary
 109          */
 110         if (fs->stride && !flexbg_size) {
 111                 retval = ext2fs_get_free_blocks2(fs, group_blk, last_blk,
 112                                                  1, bmap, &start_blk);
 113                 if (retval)
 114                         return retval;
 115                 start_blk += fs->inode_blocks_per_group;
 116                 start_blk += ((fs->stride * group) %
 117                               (last_blk - start_blk + 1));
 118                 if (start_blk >= last_blk)
 119                         start_blk = group_blk;
 120         } else
 121                 start_blk = group_blk;
 122
 123         if (flexbg_size) {
 124                 blk64_t prev_block = 0;
 125
 126                 table_offset = flexbg_size;
 127                 if (group % flexbg_size)
 128                         prev_block = ext2fs_block_bitmap_loc(fs, group - 1) + 1;
 129                 else if (last_grp == fs->group_desc_count-1) {
 130                         /*
 131                          * If we are allocating for the last flex_bg
 132                          * keep the metadata tables contiguous
 133                          */
 134                         table_offset = last_grp & (flexbg_size - 1);
 135                         if (table_offset == 0)
 136                                 table_offset = flexbg_size;
 137                         else
 138                                 table_offset++;
 139                 }
 140                 /* FIXME: Take backup group descriptor blocks into account
 141                  * if the flexbg allocations will grow to overlap them... */
 142                 start_blk = flexbg_offset(fs, group, prev_block, bmap,
 143                                           rem_grps, 1);
 144                 last_blk = ext2fs_group_last_block2(fs, last_grp);
 145         }
 146
 147         if (!ext2fs_block_bitmap_loc(fs, group)) {
 148                 retval = ext2fs_get_free_blocks2(fs, start_blk, last_blk,
 149                                                  1, bmap, &new_blk);
 150                 if (retval == EXT2_ET_BLOCK_ALLOC_FAIL)
 151                         retval = ext2fs_get_free_blocks2(fs, group_blk,
 152                                         last_blk, 1, bmap, &new_blk);
 153                 if (retval)
 154                         return retval;
 155                 ext2fs_mark_block_bitmap2(bmap, new_blk);
 156                 ext2fs_block_bitmap_loc_set(fs, group, new_blk);
 157                 if (flexbg_size) {
 158                         dgrp_t gr = ext2fs_group_of_blk2(fs, new_blk);
 159                         ext2fs_bg_free_blocks_count_set(fs, gr, ext2fs_bg_free_blocks_count(fs, gr) - 1);
 160                         ext2fs_free_blocks_count_add(fs->super, -1);
 161                         ext2fs_bg_flags_clear(fs, gr, EXT2_BG_BLOCK_UNINIT);
 162                         ext2fs_group_desc_csum_set(fs, gr);
 163                 }
 164         }
 165
 166         if (flexbg_size) {
 167                 blk64_t prev_block = 0;
 168                 if (group % flexbg_size)
 169                         prev_block = ext2fs_inode_bitmap_loc(fs, group - 1) + 1;
 170                 else
 171                         prev_block = ext2fs_block_bitmap_loc(fs, group) +
 172                                 table_offset;
 173                 /* FIXME: Take backup group descriptor blocks into account
 174                  * if the flexbg allocations will grow to overlap them... */
 175                 start_blk = flexbg_offset(fs, group, prev_block, bmap,
 176                                           rem_grps, 1);
 177                 last_blk = ext2fs_group_last_block2(fs, last_grp);
 178         }
 179
 180         if (!ext2fs_inode_bitmap_loc(fs, group)) {
 181                 retval = ext2fs_get_free_blocks2(fs, start_blk, last_blk,
 182                                                  1, bmap, &new_blk);
 183                 if (retval == EXT2_ET_BLOCK_ALLOC_FAIL)
 184                         retval = ext2fs_get_free_blocks2(fs, group_blk,
 185                                          last_blk, 1, bmap, &new_blk);
 186                 if (retval)
 187                         return retval;
 188                 ext2fs_mark_block_bitmap2(bmap, new_blk);
 189                 ext2fs_inode_bitmap_loc_set(fs, group, new_blk);
 190                 if (flexbg_size) {
 191                         dgrp_t gr = ext2fs_group_of_blk2(fs, new_blk);
 192                         ext2fs_bg_free_blocks_count_set(fs, gr, ext2fs_bg_free_blocks_count(fs, gr) - 1);
 193                         ext2fs_free_blocks_count_add(fs->super, -1);
 194                         ext2fs_bg_flags_clear(fs, gr, EXT2_BG_BLOCK_UNINIT);
 195                         ext2fs_group_desc_csum_set(fs, gr);
 196                 }
 197         }
 198
 199         /*
 200          * Allocate the inode table
 201          */
 202         if (flexbg_size) {
 203                 blk64_t prev_block = 0;
 204
 205                 if (group % flexbg_size)
 206                         prev_block = ext2fs_inode_table_loc(fs, group - 1) +
 207                                 fs->inode_blocks_per_group;
 208                 else
 209                         prev_block = ext2fs_inode_bitmap_loc(fs, group) +
 210                                 table_offset;
 211
 212                 /* FIXME: Take backup group descriptor blocks into account
 213                  * if the flexbg allocations will grow to overlap them... */
 214                 group_blk = flexbg_offset(fs, group, prev_block, bmap,
 215                                           rem_grps, fs->inode_blocks_per_group);
 216                 last_blk = ext2fs_group_last_block2(fs, last_grp);
 217         }
 218
 219         if (!ext2fs_inode_table_loc(fs, group)) {
 220                 retval = ext2fs_get_free_blocks2(fs, group_blk, last_blk,
 221                                                 fs->inode_blocks_per_group,
 222                                                 bmap, &new_blk);
 223                 if (retval)
 224                         return retval;
 225
 226                 ext2fs_mark_block_bitmap_range2(bmap,
 227                         new_blk, fs->inode_blocks_per_group);
 228                 if (flexbg_size) {
 229                         blk64_t num, blk;
 230                         num = fs->inode_blocks_per_group;
 231                         blk = new_blk;
 232                         while (num) {
 233                                 int gr = ext2fs_group_of_blk2(fs, blk);
 234                                 last_blk = ext2fs_group_last_block2(fs, gr);
 235                                 blk64_t n = num;
 236
 237                                 if (blk + num > last_blk)
 238                                         n = last_blk - blk + 1;
 239
 240                                 ext2fs_bg_free_blocks_count_set(fs, gr,
 241                                         ext2fs_bg_free_blocks_count(fs, gr) -
 242                                         n/EXT2FS_CLUSTER_RATIO(fs));
 243                                 ext2fs_bg_flags_clear(fs, gr,
 244                                         EXT2_BG_BLOCK_UNINIT);
 245                                 ext2fs_group_desc_csum_set(fs, gr);
 246                                 ext2fs_free_blocks_count_add(fs->super, -n);
 247                                 blk += n;
 248                                 num -= n;
 249                         }
 250                 }
 251                 ext2fs_inode_table_loc_set(fs, group, new_blk);
 252         }
 253         ext2fs_group_desc_csum_set(fs, group);
 254         return 0;
 255 }
 256
 257 errcode_t ext2fs_allocate_tables(ext2_filsys fs)
 258 {
 259         errcode_t       retval;
 260         dgrp_t          i;
 261         struct ext2fs_numeric_progress_struct progress;
 262
 263         if (fs->progress_ops && fs->progress_ops->init)
 264                 (fs->progress_ops->init)(fs, &progress, NULL,
 265                                          fs->group_desc_count);
 266
 267         for (i = 0; i < fs->group_desc_count; i++) {
 268                 if (fs->progress_ops && fs->progress_ops->update)
 269                         (fs->progress_ops->update)(fs, &progress, i);
 270                 retval = ext2fs_allocate_group_table(fs, i, fs->block_map);
 271                 if (retval)
 272                         return retval;
 273         }
 274         if (fs->progress_ops && fs->progress_ops->close)
 275                 (fs->progress_ops->close)(fs, &progress, NULL);
 276         return 0;
 277 }
 278