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         struct ext2_new_group_input input;
  25         struct ext2_super_block *sb = fs->super;
  26         unsigned long           new_desc_blocks;
  27         ext2_filsys             new_fs;
  28         errcode_t               retval;
  29         dgrp_t                  i;
  30         blk_t                   size;
  31         int                     fd, r_frac, overhead;
  32
  33         printf(_("Filesystem at %s is mounted on %s; "
  34                  "on-line resizing required\n"), fs->device_name, mtpt);
  35
  36         if (*new_size < sb->s_blocks_count) {
  37                 printf(_("On-line shrinking from %u to %u not supported.\n"),
  38                        sb->s_blocks_count, *new_size);
  39                 exit(1);
  40         }
  41
  42         /*
  43          * If the number of descriptor blocks is going to increase,
  44          * the on-line resizing inode must be present.
  45          */
  46         new_desc_blocks = ext2fs_div_ceil(
  47                 ext2fs_div_ceil(*new_size -
  48                                 fs->super->s_first_data_block,
  49                                 EXT2_BLOCKS_PER_GROUP(fs->super)),
  50                 EXT2_DESC_PER_BLOCK(fs->super));
  51         printf("old desc_blocks = %lu, new_desc_blocks = %lu\n",
  52                fs->desc_blocks, new_desc_blocks);
  53         if (!(fs->super->s_feature_compat &
  54               EXT2_FEATURE_COMPAT_RESIZE_INODE) &&
  55             new_desc_blocks != fs->desc_blocks) {
  56                 com_err(program_name, 0,
  57                         _("Filesystem does not support online resizing"));
  58                 exit(1);
  59         }
  60
  61         fd = open(mtpt, O_RDONLY);
  62         if (fd < 0) {
  63                 com_err(program_name, errno,
  64                         _("while trying to open mountpoint %s"), mtpt);
  65                 exit(1);
  66         }
  67
  68         size=sb->s_blocks_count;
  69         if (ioctl(fd, EXT2_IOC_GROUP_EXTEND, &size)) {
  70                 if (errno == EPERM)
  71                         com_err(program_name, 0,
  72                                 _("Permission denied to resize filesystem"));
  73                 else if (errno == ENOTTY)
  74                         com_err(program_name, 0,
  75                         _("Kernel does not support online resizing"));
  76                 else
  77                         com_err(program_name, errno,
  78                         _("While checking for on-line resizing support"));
  79                 exit(1);
  80         }
  81
  82         r_frac = ext2fs_div_ceil(100 * sb->s_r_blocks_count, sb->s_blocks_count);
  83
  84         retval = ext2fs_read_bitmaps(fs);
  85         if (retval)
  86                 return retval;
  87
  88         retval = ext2fs_dup_handle(fs, &new_fs);
  89         if (retval)
  90                 return retval;
  91
  92         retval = adjust_fs_info(new_fs, fs, *new_size);
  93         if (retval)
  94                 return retval;
  95
  96         printf(_("Performing an on-line resize of %s to %u (%dk) blocks.\n"),
  97                fs->device_name, *new_size, fs->blocksize / 1024);
  98
  99         size = fs->group_desc_count * sb->s_blocks_per_group +
 100                 sb->s_first_data_block;
 101         if (size > *new_size)
 102                 size = *new_size;
 103
 104         if (ioctl(fd, EXT2_IOC_GROUP_EXTEND, &size)) {
 105                 com_err(program_name, errno,
 106                         _("While trying to extend the last group"));
 107                 exit(1);
 108         }
 109
 110         for (i = fs->group_desc_count;
 111              i < new_fs->group_desc_count; i++) {
 112
 113                 overhead = (int) (2 + new_fs->inode_blocks_per_group);
 114
 115                 if (ext2fs_bg_has_super(new_fs, new_fs->group_desc_count - 1))
 116                         overhead += 1 + new_fs->desc_blocks +
 117                                 new_fs->super->s_reserved_gdt_blocks;
 118
 119                 input.group = i;
 120                 input.block_bitmap = new_fs->group_desc[i].bg_block_bitmap;
 121                 input.inode_bitmap = new_fs->group_desc[i].bg_inode_bitmap;
 122                 input.inode_table = new_fs->group_desc[i].bg_inode_table;
 123                 input.blocks_count = sb->s_blocks_per_group;
 124                 if (i == new_fs->group_desc_count-1) {
 125                         input.blocks_count = new_fs->super->s_blocks_count -
 126                                 sb->s_first_data_block -
 127                                 (i * sb->s_blocks_per_group);
 128                 }
 129                 input.reserved_blocks = e2p_percent(r_frac,
 130                                                     input.blocks_count);
 131
 132 #if 0
 133                 printf("new block bitmap is at 0x%04x\n", input.block_bitmap);
 134                 printf("new inode bitmap is at 0x%04x\n", input.inode_bitmap);
 135                 printf("new inode table is at 0x%04x-0x%04x\n",
 136                        input.inode_table,
 137                        input.inode_table + new_fs->inode_blocks_per_group-1);
 138                 printf("new group has %u blocks\n", input.blocks_count);
 139                 printf("new group will reserve %d blocks\n",
 140                        input.reserved_blocks);
 141                 printf("new group has %d free blocks\n",
 142                        new_fs->group_desc[i].bg_free_blocks_count);
 143                 printf("new group has %d free inodes (%d blocks)\n",
 144                        new_fs->group_desc[i].bg_free_inodes_count,
 145                        new_fs->inode_blocks_per_group);
 146                 printf("Adding group #%d\n", input.group);
 147 #endif
 148
 149                 if (ioctl(fd, EXT2_IOC_GROUP_ADD, &input) < 0) {
 150                         com_err(program_name, errno,
 151                                 _("While trying to add group #%d"),
 152                                 input.group);
 153                         exit(1);
 154                 }
 155         }
 156
 157         ext2fs_free(new_fs);
 158         close(fd);
 159
 160         return 0;
 161 }