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)
  23 {
  24         struct ext2_new_group_input input;
  25         struct ext2_super_block *sb = fs->super;
  26         ext2_filsys             new_fs;
  27         errcode_t               retval;
  28         dgrp_t                  i;
  29         blk_t                   size;
  30         int                     fd, r_frac, overhead, new_desc_blocks;
  31
  32         printf(_("Filesystem at %s is mounted on %s; "
  33                  "on-line resizing required\n"), fs->device_name, mtpt);
  34
  35         if (*new_size < sb->s_blocks_count) {
  36                 printf(_("On-line shrinking from %u to %u not supported.\n"),
  37                        sb->s_blocks_count, *new_size);
  38                 exit(1);
  39         }
  40
  41         /*
  42          * If the number of descriptor blocks is going to increase,
  43          * the on-line resizing inode must be present.
  44          */
  45         new_desc_blocks = ext2fs_div_ceil(
  46                 ext2fs_div_ceil(*new_size -
  47                                 fs->super->s_first_data_block,
  48                                 EXT2_BLOCKS_PER_GROUP(fs->super)),
  49                 EXT2_DESC_PER_BLOCK(fs->super));
  50         printf("old desc_blocks = %d, new_desc_blocks = %d\n", fs->desc_blocks,
  51                new_desc_blocks);
  52         if (!(fs->super->s_feature_compat &
  53               EXT2_FEATURE_COMPAT_RESIZE_INODE) &&
  54             new_desc_blocks != fs->desc_blocks) {
  55                 com_err(program_name, 0,
  56                         _("Filesystem does not support online resizing"));
  57                 exit(1);
  58         }
  59
  60         fd = open(mtpt, O_RDONLY);
  61         if (fd < 0) {
  62                 com_err(program_name, errno,
  63                         _("while trying to open mountpoint %s"), mtpt);
  64                 exit(1);
  65         }
  66
  67         size=sb->s_blocks_count;
  68         if (ioctl(fd, EXT2_IOC_GROUP_EXTEND, &size)) {
  69                 if (errno == EPERM)
  70                         com_err(program_name, 0,
  71                                 _("Permission denied to resize filesystem"));
  72                 else if (errno == ENOTTY)
  73                         com_err(program_name, 0,
  74                         _("Kernel does not support online resizing"));
  75                 else
  76                         com_err(program_name, errno,
  77                         _("While checking for on-line resizing support"));
  78                 exit(1);
  79         }
  80
  81         r_frac = ext2fs_div_ceil(100 * sb->s_r_blocks_count, sb->s_blocks_count);
  82
  83         retval = ext2fs_read_bitmaps(fs);
  84         if (retval)
  85                 return retval;
  86
  87         retval = ext2fs_dup_handle(fs, &new_fs);
  88         if (retval)
  89                 return retval;
  90
  91         retval = adjust_fs_info(new_fs, fs, *new_size);
  92         if (retval)
  93                 return retval;
  94
  95         printf(_("Performing an on-line resize of %s to %u (%dk) blocks.\n"),
  96                fs->device_name, *new_size, fs->blocksize / 1024);
  97
  98         size = fs->group_desc_count * sb->s_blocks_per_group +
  99                 sb->s_first_data_block;
 100         if (size > *new_size)
 101                 size = *new_size;
 102
 103         if (ioctl(fd, EXT2_IOC_GROUP_EXTEND, &size)) {
 104                 com_err(program_name, errno,
 105                         _("While trying to extend the last group"));
 106                 exit(1);
 107         }
 108
 109         for (i = fs->group_desc_count;
 110              i < new_fs->group_desc_count; i++) {
 111
 112                 overhead = (int) (2 + new_fs->inode_blocks_per_group);
 113
 114                 if (ext2fs_bg_has_super(new_fs, new_fs->group_desc_count - 1))
 115                         overhead += 1 + new_fs->desc_blocks +
 116                                 new_fs->super->s_reserved_gdt_blocks;
 117
 118                 input.group = i;
 119                 input.block_bitmap = new_fs->group_desc[i].bg_block_bitmap;
 120                 input.inode_bitmap = new_fs->group_desc[i].bg_inode_bitmap;
 121                 input.inode_table = new_fs->group_desc[i].bg_inode_table;
 122                 input.blocks_count = sb->s_blocks_per_group;
 123                 if (i == new_fs->group_desc_count-1) {
 124                         input.blocks_count = new_fs->super->s_blocks_count -
 125                                 sb->s_first_data_block -
 126                                 (i * sb->s_blocks_per_group);
 127                 }
 128                 input.reserved_blocks = e2p_percent(r_frac,
 129                                                     input.blocks_count);
 130
 131 #if 0
 132                 printf("new block bitmap is at 0x%04x\n", input.block_bitmap);
 133                 printf("new inode bitmap is at 0x%04x\n", input.inode_bitmap);
 134                 printf("new inode table is at 0x%04x-0x%04x\n",
 135                        input.inode_table,
 136                        input.inode_table + new_fs->inode_blocks_per_group-1);
 137                 printf("new group has %u blocks\n", input.blocks_count);
 138                 printf("new group will reserve %d blocks\n",
 139                        input.reserved_blocks);
 140                 printf("new group has %d free blocks\n",
 141                        new_fs->group_desc[i].bg_free_blocks_count);
 142                 printf("new group has %d free inodes (%d blocks)\n",
 143                        new_fs->group_desc[i].bg_free_inodes_count,
 144                        new_fs->inode_blocks_per_group);
 145                 printf("Adding group #%d\n", input.group);
 146 #endif
 147
 148                 if (ioctl(fd, EXT2_IOC_GROUP_ADD, &input) < 0) {
 149                         com_err(program_name, errno,
 150                                 _("While trying to add group #%d"),
 151                                 input.group);
 152                         exit(1);
 153                 }
 154         }
 155
 156         ext2fs_free(new_fs);
 157         close(fd);
 158
 159         return 0;
 160 }