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 #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 blk_t flexbg_offset(ext2_filsys fs, dgrp_t group, blk64_t start_blk,
  38                            ext2fs_block_bitmap bmap, int offset, int size,
  39                            int elem_size)
  40 {
  41         int             flexbg, flexbg_size;
  42         blk_t           last_blk, first_free = 0;
  43         dgrp_t          last_grp;
  44
  45         flexbg_size = 1 << fs->super->s_log_groups_per_flex;
  46         flexbg = group / flexbg_size;
  47
  48         if (size > (int) (fs->super->s_blocks_per_group / 8))
  49                 size = (int) fs->super->s_blocks_per_group / 8;
  50
  51         if (offset)
  52                 offset -= 1;
  53
  54         /*
  55          * Don't do a long search if the previous block
  56          * search is still valid.
  57          */
  58         if (start_blk && group % flexbg_size) {
  59                 if (ext2fs_test_block_bitmap_range2(bmap, start_blk + elem_size,
  60                                                    size))
  61                         return start_blk + elem_size;
  62         }
  63
  64         start_blk = ext2fs_group_first_block(fs, flexbg_size * flexbg);
  65         last_grp = group | (flexbg_size - 1);
  66         if (last_grp > fs->group_desc_count)
  67                 last_grp = fs->group_desc_count;
  68         last_blk = ext2fs_group_last_block(fs, last_grp);
  69
  70         /* Find the first available block */
  71         if (ext2fs_get_free_blocks(fs, start_blk, last_blk, 1, bmap,
  72                                    &first_free))
  73                 return first_free;
  74
  75         if (ext2fs_get_free_blocks(fs, first_free + offset, last_blk, size,
  76                                    bmap, &first_free))
  77                 return first_free;
  78
  79         return first_free;
  80 }
  81
  82 errcode_t ext2fs_allocate_group_table(ext2_filsys fs, dgrp_t group,
  83                                       ext2fs_block_bitmap bmap)
  84 {
  85         errcode_t       retval;
  86         blk_t           group_blk, start_blk, last_blk, new_blk, blk;
  87         dgrp_t          last_grp = 0;
  88         int             j, rem_grps = 0, flexbg_size = 0;
  89
  90         group_blk = ext2fs_group_first_block(fs, group);
  91         last_blk = ext2fs_group_last_block(fs, group);
  92
  93         if (!bmap)
  94                 bmap = fs->block_map;
  95
  96         if (EXT2_HAS_INCOMPAT_FEATURE(fs->super,
  97                                       EXT4_FEATURE_INCOMPAT_FLEX_BG) &&
  98             fs->super->s_log_groups_per_flex) {
  99                 flexbg_size = 1 << fs->super->s_log_groups_per_flex;
 100                 last_grp = group | (flexbg_size - 1);
 101                 rem_grps = last_grp - group;
 102                 if (last_grp > fs->group_desc_count)
 103                         last_grp = fs->group_desc_count;
 104         }
 105
 106         /*
 107          * Allocate the block and inode bitmaps, if necessary
 108          */
 109         if (fs->stride) {
 110                 retval = ext2fs_get_free_blocks(fs, group_blk, last_blk,
 111                                                 1, bmap, &start_blk);
 112                 if (retval)
 113                         return retval;
 114                 start_blk += fs->inode_blocks_per_group;
 115                 start_blk += ((fs->stride * group) %
 116                               (last_blk - start_blk + 1));
 117                 if (start_blk >= last_blk)
 118                         start_blk = group_blk;
 119         } else
 120                 start_blk = group_blk;
 121
 122         if (flexbg_size) {
 123                 blk64_t prev_block = 0;
 124
 125                 if (group && fs->group_desc[group-1].bg_block_bitmap)
 126                         prev_block = fs->group_desc[group-1].bg_block_bitmap;
 127                 start_blk = flexbg_offset(fs, group, prev_block, bmap,
 128                                                  0, rem_grps, 1);
 129                 last_blk = ext2fs_group_last_block(fs, last_grp);
 130         }
 131
 132         if (!fs->group_desc[group].bg_block_bitmap) {
 133                 retval = ext2fs_get_free_blocks(fs, start_blk, last_blk,
 134                                                 1, bmap, &new_blk);
 135                 if (retval == EXT2_ET_BLOCK_ALLOC_FAIL)
 136                         retval = ext2fs_get_free_blocks(fs, group_blk,
 137                                         last_blk, 1, bmap, &new_blk);
 138                 if (retval)
 139                         return retval;
 140                 ext2fs_mark_block_bitmap2(bmap, new_blk);
 141                 fs->group_desc[group].bg_block_bitmap = new_blk;
 142                 if (flexbg_size) {
 143                         dgrp_t gr = ext2fs_group_of_blk(fs, new_blk);
 144                         fs->group_desc[gr].bg_free_blocks_count--;
 145                         ext2fs_free_blocks_count_add(fs->super, -1);
 146                         ext2fs_bg_flag_clear(fs, gr, EXT2_BG_BLOCK_UNINIT);
 147                         ext2fs_group_desc_csum_set(fs, gr);
 148                 }
 149         }
 150
 151         if (flexbg_size) {
 152                 blk_t prev_block = 0;
 153                 if (group && fs->group_desc[group-1].bg_inode_bitmap)
 154                         prev_block = fs->group_desc[group-1].bg_inode_bitmap;
 155                 start_blk = flexbg_offset(fs, group, prev_block, bmap,
 156                                                  flexbg_size, rem_grps, 1);
 157                 last_blk = ext2fs_group_last_block(fs, last_grp);
 158         }
 159
 160         if (!fs->group_desc[group].bg_inode_bitmap) {
 161                 retval = ext2fs_get_free_blocks(fs, start_blk, last_blk,
 162                                                 1, bmap, &new_blk);
 163                 if (retval == EXT2_ET_BLOCK_ALLOC_FAIL)
 164                         retval = ext2fs_get_free_blocks(fs, group_blk,
 165                                         last_blk, 1, bmap, &new_blk);
 166                 if (retval)
 167                         return retval;
 168                 ext2fs_mark_block_bitmap2(bmap, new_blk);
 169                 fs->group_desc[group].bg_inode_bitmap = new_blk;
 170                 if (flexbg_size) {
 171                         dgrp_t gr = ext2fs_group_of_blk(fs, new_blk);
 172                         fs->group_desc[gr].bg_free_blocks_count--;
 173                         ext2fs_free_blocks_count_add(fs->super, -1);
 174                         ext2fs_bg_flag_clear(fs, gr, EXT2_BG_BLOCK_UNINIT);
 175                         ext2fs_group_desc_csum_set(fs, gr);
 176                 }
 177         }
 178
 179         /*
 180          * Allocate the inode table
 181          */
 182         if (flexbg_size) {
 183                 blk_t prev_block = 0;
 184                 if (group && fs->group_desc[group-1].bg_inode_table)
 185                         prev_block = fs->group_desc[group-1].bg_inode_table;
 186                 group_blk = flexbg_offset(fs, group, prev_block, bmap,
 187                                                  flexbg_size * 2,
 188                                                  fs->inode_blocks_per_group *
 189                                                  rem_grps,
 190                                                  fs->inode_blocks_per_group);
 191                 last_blk = ext2fs_group_last_block(fs, last_grp);
 192         }
 193
 194         if (!fs->group_desc[group].bg_inode_table) {
 195                 retval = ext2fs_get_free_blocks(fs, group_blk, last_blk,
 196                                                 fs->inode_blocks_per_group,
 197                                                 bmap, &new_blk);
 198                 if (retval)
 199                         return retval;
 200                 for (j=0, blk = new_blk;
 201                      j < fs->inode_blocks_per_group;
 202                      j++, blk++) {
 203                         ext2fs_mark_block_bitmap2(bmap, blk);
 204                         if (flexbg_size) {
 205                                 dgrp_t gr = ext2fs_group_of_blk(fs, blk);
 206                                 fs->group_desc[gr].bg_free_blocks_count--;
 207                                 ext2fs_free_blocks_count_add(fs->super, -1);
 208                                 ext2fs_bg_flag_clear(fs, gr,
 209                                                      EXT2_BG_BLOCK_UNINIT);
 210                                 ext2fs_group_desc_csum_set(fs, gr);
 211                         }
 212                 }
 213                 fs->group_desc[group].bg_inode_table = new_blk;
 214         }
 215         ext2fs_group_desc_csum_set(fs, group);
 216         return 0;
 217 }
 218
 219 errcode_t ext2fs_allocate_tables(ext2_filsys fs)
 220 {
 221         errcode_t       retval;
 222         dgrp_t          i;
 223         struct ext2fs_numeric_progress_struct progress;
 224
 225         ext2fs_numeric_progress_init(fs, &progress, NULL,
 226                                      fs->group_desc_count);
 227
 228         for (i = 0; i < fs->group_desc_count; i++) {
 229                 ext2fs_numeric_progress_update(fs, &progress, i);
 230                 retval = ext2fs_allocate_group_table(fs, i, fs->block_map);
 231                 if (retval)
 232                         return retval;
 233         }
 234         ext2fs_numeric_progress_close(fs, &progress, NULL);
 235         return 0;
 236 }
 237