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 < sb->s_blocks_count) {
  41                 com_err(program_name, 0, _("On-line shrinking not supported"));
  42                 exit(1);
  43         }
  44
  45         /*
  46          * If the number of descriptor blocks is going to increase,
  47          * the on-line resizing inode must be present.
  48          */
  49         new_desc_blocks = ext2fs_div_ceil(
  50                 ext2fs_div_ceil(*new_size -
  51                                 fs->super->s_first_data_block,
  52                                 EXT2_BLOCKS_PER_GROUP(fs->super)),
  53                 EXT2_DESC_PER_BLOCK(fs->super));
  54         printf("old desc_blocks = %lu, new_desc_blocks = %lu\n",
  55                fs->desc_blocks, new_desc_blocks);
  56         if (!(fs->super->s_feature_compat &
  57               EXT2_FEATURE_COMPAT_RESIZE_INODE) &&
  58             new_desc_blocks != fs->desc_blocks) {
  59                 com_err(program_name, 0,
  60                         _("Filesystem does not support online resizing"));
  61                 exit(1);
  62         }
  63
  64         fd = open(mtpt, O_RDONLY);
  65         if (fd < 0) {
  66                 com_err(program_name, errno,
  67                         _("while trying to open mountpoint %s"), mtpt);
  68                 exit(1);
  69         }
  70
  71         size=sb->s_blocks_count;
  72         if (ioctl(fd, EXT2_IOC_GROUP_EXTEND, &size)) {
  73                 if (errno == EPERM)
  74                         com_err(program_name, 0,
  75                                 _("Permission denied to resize filesystem"));
  76                 else if (errno == ENOTTY)
  77                         com_err(program_name, 0,
  78                         _("Kernel does not support online resizing"));
  79                 else
  80                         com_err(program_name, errno,
  81                         _("While checking for on-line resizing support"));
  82                 exit(1);
  83         }
  84
  85         percent = (sb->s_r_blocks_count * 100.0) / sb->s_blocks_count;
  86
  87         retval = ext2fs_read_bitmaps(fs);
  88         if (retval)
  89                 return retval;
  90
  91         retval = ext2fs_dup_handle(fs, &new_fs);
  92         if (retval)
  93                 return retval;
  94
  95         /* The current method of adding one block group at a time to a
  96          * mounted filesystem means it is impossible to accomodate the
  97          * flex_bg allocation method of placing the metadata together
  98          * in a single block group.  For now we "fix" this issue by
  99          * using the traditional layout for new block groups, where
 100          * each block group is self-contained and contains its own
 101          * bitmap blocks and inode tables.  This means we don't get
 102          * the layout advantages of flex_bg in the new block groups,
 103          * but at least it allows on-line resizing to function.
 104          */
 105         new_fs->super->s_feature_incompat &= ~EXT4_FEATURE_INCOMPAT_FLEX_BG;
 106         retval = adjust_fs_info(new_fs, fs, 0, *new_size);
 107         if (retval)
 108                 return retval;
 109
 110         printf(_("Performing an on-line resize of %s to %u (%dk) blocks.\n"),
 111                fs->device_name, *new_size, fs->blocksize / 1024);
 112
 113         size = fs->group_desc_count * sb->s_blocks_per_group +
 114                 sb->s_first_data_block;
 115         if (size > *new_size)
 116                 size = *new_size;
 117
 118         if (ioctl(fd, EXT2_IOC_GROUP_EXTEND, &size)) {
 119                 com_err(program_name, errno,
 120                         _("While trying to extend the last group"));
 121                 exit(1);
 122         }
 123
 124         for (i = fs->group_desc_count;
 125              i < new_fs->group_desc_count; i++) {
 126
 127                 overhead = (int) (2 + new_fs->inode_blocks_per_group);
 128
 129                 if (ext2fs_bg_has_super(new_fs, new_fs->group_desc_count - 1))
 130                         overhead += 1 + new_fs->desc_blocks +
 131                                 new_fs->super->s_reserved_gdt_blocks;
 132
 133                 input.group = i;
 134                 input.block_bitmap = new_fs->group_desc[i].bg_block_bitmap;
 135                 input.inode_bitmap = new_fs->group_desc[i].bg_inode_bitmap;
 136                 input.inode_table = new_fs->group_desc[i].bg_inode_table;
 137                 input.blocks_count = sb->s_blocks_per_group;
 138                 if (i == new_fs->group_desc_count-1) {
 139                         input.blocks_count = new_fs->super->s_blocks_count -
 140                                 sb->s_first_data_block -
 141                                 (i * sb->s_blocks_per_group);
 142                 }
 143                 input.reserved_blocks = (blk_t) (percent * input.blocks_count
 144                                                  / 100.0);
 145
 146 #if 0
 147                 printf("new block bitmap is at 0x%04x\n", input.block_bitmap);
 148                 printf("new inode bitmap is at 0x%04x\n", input.inode_bitmap);
 149                 printf("new inode table is at 0x%04x-0x%04x\n",
 150                        input.inode_table,
 151                        input.inode_table + new_fs->inode_blocks_per_group-1);
 152                 printf("new group has %u blocks\n", input.blocks_count);
 153                 printf("new group will reserve %d blocks\n",
 154                        input.reserved_blocks);
 155                 printf("new group has %d free blocks\n",
 156                        new_fs->group_desc[i].bg_free_blocks_count);
 157                 printf("new group has %d free inodes (%d blocks)\n",
 158                        new_fs->group_desc[i].bg_free_inodes_count,
 159                        new_fs->inode_blocks_per_group);
 160                 printf("Adding group #%d\n", input.group);
 161 #endif
 162
 163                 if (use_old_ioctl &&
 164                     ioctl(fd, EXT2_IOC_GROUP_ADD, &input) == 0)
 165                         continue;
 166                 else
 167                         use_old_ioctl = 0;
 168
 169                 input64.group = input.group;
 170                 input64.block_bitmap = input.block_bitmap;
 171                 input64.inode_bitmap = input.inode_bitmap;
 172                 input64.inode_table = input.inode_table;
 173                 input64.blocks_count = input.blocks_count;
 174                 input64.reserved_blocks = input.reserved_blocks;
 175                 input64.unused = input.unused;
 176
 177                 if (ioctl(fd, EXT4_IOC_GROUP_ADD, &input64) < 0) {
 178                         com_err(program_name, errno,
 179                                 _("While trying to add group #%d"),
 180                                 input.group);
 181                         exit(1);
 182                 }
 183         }
 184
 185         ext2fs_free(new_fs);
 186         close(fd);
 187
 188         return 0;
 189 #else
 190         printf(_("Filesystem at %s is mounted on %s, and on-line resizing is "
 191                  "not supported on this system.\n"), fs->device_name, mtpt);
 192         exit(1);
 193 #endif
 194 }