resize/online.c

   1 /*
   2  * online.c --- Do on-line resizing of the ext3 filesystem
   3  *
   4  * Copyright (C) 2006 by Theodore Ts'o
   5  *
   6  * %Begin-Header%
   7  * This file may be redistributed under the terms of the GNU Public
   8  * License.
   9  * %End-Header%
  10  */
  11
  12 #include "resize2fs.h"
  13 #ifdef HAVE_SYS_IOCTL_H
  14 #include <sys/ioctl.h>
  15 #endif
  16 #include <sys/stat.h>
  17 #include <fcntl.h>
  18
  19 extern char *program_name;
  20
  21 errcode_t online_resize_fs(ext2_filsys fs, const char *mtpt,
  22                            blk_t *new_size, int flags EXT2FS_ATTR((unused)))
  23 {
  24 #ifdef __linux__
  25         struct ext2_new_group_input input;
  26         struct ext4_new_group_input input64;
  27         struct ext2_super_block *sb = fs->super;
  28         unsigned long           new_desc_blocks;
  29         ext2_filsys             new_fs;
  30         errcode_t               retval;
  31         double                  percent;
  32         dgrp_t                  i;
  33         blk_t                   size;
  34         int                     fd, overhead;
  35         int                     use_old_ioctl = 1;
  36
  37         printf(_("Filesystem at %s is mounted on %s; "
  38                  "on-line resizing required\n"), fs->device_name, mtpt);
  39
  40         if (*new_size < ext2fs_blocks_count(sb)) {
  41                 printf(_("On-line shrinking from %llu to %u not supported.\n"),
  42                        ext2fs_blocks_count(sb), *new_size);
  43                 exit(1);
  44         }
  45
  46         /*
  47          * If the number of descriptor blocks is going to increase,
  48          * the on-line resizing inode must be present.
  49          */
  50         new_desc_blocks = ext2fs_div_ceil(
  51                 ext2fs_div_ceil(*new_size -
  52                                 fs->super->s_first_data_block,
  53                                 EXT2_BLOCKS_PER_GROUP(fs->super)),
  54                 EXT2_DESC_PER_BLOCK(fs->super));
  55         printf("old desc_blocks = %lu, new_desc_blocks = %lu\n",
  56                fs->desc_blocks, new_desc_blocks);
  57         if (!(fs->super->s_feature_compat &
  58               EXT2_FEATURE_COMPAT_RESIZE_INODE) &&
  59             new_desc_blocks != fs->desc_blocks) {
  60                 com_err(program_name, 0,
  61                         _("Filesystem does not support online resizing"));
  62                 exit(1);
  63         }
  64
  65         fd = open(mtpt, O_RDONLY);
  66         if (fd < 0) {
  67                 com_err(program_name, errno,
  68                         _("while trying to open mountpoint %s"), mtpt);
  69                 exit(1);
  70         }
  71
  72         size=ext2fs_blocks_count(sb);
  73         if (ioctl(fd, EXT2_IOC_GROUP_EXTEND, &size)) {
  74                 if (errno == EPERM)
  75                         com_err(program_name, 0,
  76                                 _("Permission denied to resize filesystem"));
  77                 else if (errno == ENOTTY)
  78                         com_err(program_name, 0,
  79                         _("Kernel does not support online resizing"));
  80                 else
  81                         com_err(program_name, errno,
  82                         _("While checking for on-line resizing support"));
  83                 exit(1);
  84         }
  85
  86         percent = (ext2fs_r_blocks_count(sb) * 100.0) /
  87                 ext2fs_blocks_count(sb);
  88
  89         retval = ext2fs_read_bitmaps(fs);
  90         if (retval)
  91                 return retval;
  92
  93         retval = ext2fs_dup_handle(fs, &new_fs);
  94         if (retval)
  95                 return retval;
  96
  97         /* The current method of adding one block group at a time to a
  98          * mounted filesystem means it is impossible to accomodate the
  99          * flex_bg allocation method of placing the metadata together
 100          * in a single block group.  For now we "fix" this issue by
 101          * using the traditional layout for new block groups, where
 102          * each block group is self-contained and contains its own
 103          * bitmap blocks and inode tables.  This means we don't get
 104          * the layout advantages of flex_bg in the new block groups,
 105          * but at least it allows on-line resizing to function.
 106          */
 107         new_fs->super->s_feature_incompat &= ~EXT4_FEATURE_INCOMPAT_FLEX_BG;
 108         retval = adjust_fs_info(new_fs, fs, 0, *new_size);
 109         if (retval)
 110                 return retval;
 111
 112         printf(_("Performing an on-line resize of %s to %u (%dk) blocks.\n"),
 113                fs->device_name, *new_size, fs->blocksize / 1024);
 114
 115         size = fs->group_desc_count * sb->s_blocks_per_group +
 116                 sb->s_first_data_block;
 117         if (size > *new_size)
 118                 size = *new_size;
 119
 120         if (ioctl(fd, EXT2_IOC_GROUP_EXTEND, &size)) {
 121                 com_err(program_name, errno,
 122                         _("While trying to extend the last group"));
 123                 exit(1);
 124         }
 125
 126         for (i = fs->group_desc_count;
 127              i < new_fs->group_desc_count; i++) {
 128
 129                 overhead = (int) (2 + new_fs->inode_blocks_per_group);
 130
 131                 if (ext2fs_bg_has_super(new_fs, new_fs->group_desc_count - 1))
 132                         overhead += 1 + new_fs->desc_blocks +
 133                                 new_fs->super->s_reserved_gdt_blocks;
 134
 135                 input.group = i;
 136                 input.block_bitmap = ext2fs_block_bitmap_loc(new_fs, i);
 137                 input.inode_bitmap = ext2fs_inode_bitmap_loc(new_fs, i);
 138                 input.inode_table = ext2fs_inode_table_loc(new_fs, i);
 139                 input.blocks_count = sb->s_blocks_per_group;
 140                 if (i == new_fs->group_desc_count-1) {
 141                         input.blocks_count = ext2fs_blocks_count(new_fs->super) -
 142                                 sb->s_first_data_block -
 143                                 (i * sb->s_blocks_per_group);
 144                 }
 145                 input.reserved_blocks = (blk_t) (percent * input.blocks_count
 146                                                  / 100.0);
 147
 148 #if 0
 149                 printf("new block bitmap is at 0x%04x\n", input.block_bitmap);
 150                 printf("new inode bitmap is at 0x%04x\n", input.inode_bitmap);
 151                 printf("new inode table is at 0x%04x-0x%04x\n",
 152                        input.inode_table,
 153                        input.inode_table + new_fs->inode_blocks_per_group-1);
 154                 printf("new group has %u blocks\n", input.blocks_count);
 155                 printf("new group will reserve %d blocks\n",
 156                        input.reserved_blocks);
 157                 printf("new group has %d free blocks\n",
 158                        ext2fs_bg_free_blocks_count(new_fs, i),
 159                 printf("new group has %d free inodes (%d blocks)\n",
 160                        ext2fs_bg_free_inodes_count(new_fs, i),
 161                        new_fs->inode_blocks_per_group);
 162                 printf("Adding group #%d\n", input.group);
 163 #endif
 164
 165                 if (use_old_ioctl &&
 166                     ioctl(fd, EXT2_IOC_GROUP_ADD, &input) == 0)
 167                         continue;
 168                 else
 169                         use_old_ioctl = 0;
 170
 171                 input64.group = input.group;
 172                 input64.block_bitmap = input.block_bitmap;
 173                 input64.inode_bitmap = input.inode_bitmap;
 174                 input64.inode_table = input.inode_table;
 175                 input64.blocks_count = input.blocks_count;
 176                 input64.reserved_blocks = input.reserved_blocks;
 177                 input64.unused = input.unused;
 178
 179                 if (ioctl(fd, EXT4_IOC_GROUP_ADD, &input64) < 0) {
 180                         com_err(program_name, errno,
 181                                 _("While trying to add group #%d"),
 182                                 input.group);
 183                         exit(1);
 184                 }
 185         }
 186
 187         ext2fs_free(new_fs);
 188         close(fd);
 189
 190         return 0;
 191 #else
 192         printf(_("Filesystem at %s is mounted on %s, and on-line resizing is "
 193                  "not supported on this system.\n"), fs->device_name, mtpt);
 194         exit(1);
 195 #endif
 196 }