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;
  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         fd = open(mtpt, O_RDONLY);
  42         if (fd < 0) {
  43                 com_err(program_name, errno,
  44                         _("while trying to open mountpoint %s"), mtpt);
  45                 exit(1);
  46         }
  47
  48         size=sb->s_blocks_count;
  49         if (ioctl(fd, EXT2_IOC_GROUP_EXTEND, &size)) {
  50                 if (errno == EPERM)
  51                         com_err(program_name, 0,
  52                                 _("Permission denied to resize filesystem"));
  53                 else if (errno == ENOTTY)
  54                         com_err(program_name, 0,
  55                         _("Filesystem does not support online resizing"));
  56                 else
  57                         com_err(program_name, errno,
  58                         _("While checking for on-line resizing support"));
  59                 exit(1);
  60         }
  61
  62         r_frac = ((100 * sb->s_r_blocks_count) + sb->s_blocks_count-1) /
  63                 sb->s_blocks_count;
  64
  65         retval = ext2fs_read_bitmaps(fs);
  66         if (retval)
  67                 return retval;
  68
  69         retval = ext2fs_dup_handle(fs, &new_fs);
  70         if (retval)
  71                 return retval;
  72
  73         retval = adjust_fs_info(new_fs, fs, *new_size);
  74         if (retval)
  75                 return retval;
  76
  77         printf(_("Performing an on-line resize of %s to %d (%dk) blocks.\n"),
  78                fs->device_name, *new_size, fs->blocksize / 1024);
  79
  80         size = fs->group_desc_count * sb->s_blocks_per_group +
  81                 sb->s_first_data_block;
  82         if (size > *new_size)
  83                 size = *new_size;
  84
  85         if (ioctl(fd, EXT2_IOC_GROUP_EXTEND, &size)) {
  86                 com_err(program_name, errno,
  87                         _("While trying to extend the last group"));
  88                 exit(1);
  89         }
  90
  91         for (i = fs->group_desc_count;
  92              i < new_fs->group_desc_count; i++) {
  93
  94                 overhead = (int) (2 + new_fs->inode_blocks_per_group);
  95
  96                 if (ext2fs_bg_has_super(new_fs, new_fs->group_desc_count - 1))
  97                         overhead += 1 + new_fs->desc_blocks +
  98                                 new_fs->super->s_reserved_gdt_blocks;
  99
 100                 input.group = i;
 101                 input.block_bitmap = new_fs->group_desc[i].bg_block_bitmap;
 102                 input.inode_bitmap = new_fs->group_desc[i].bg_inode_bitmap;
 103                 input.inode_table = new_fs->group_desc[i].bg_inode_table;
 104                 input.blocks_count = sb->s_blocks_per_group;
 105                 if (i == new_fs->group_desc_count-1) {
 106                         input.blocks_count = new_fs->super->s_blocks_count -
 107                                 sb->s_first_data_block -
 108                                 (i * sb->s_blocks_per_group);
 109                 }
 110                 input.reserved_blocks = input.blocks_count * r_frac / 100;
 111
 112 #if 0
 113                 printf("new block bitmap is at 0x%04x\n", input.block_bitmap);
 114                 printf("new inode bitmap is at 0x%04x\n", input.inode_bitmap);
 115                 printf("new inode table is at 0x%04x-0x%04x\n",
 116                        input.inode_table,
 117                        input.inode_table + new_fs->inode_blocks_per_group-1);
 118                 printf("new group has %d blocks\n", input.blocks_count);
 119                 printf("new group will reserve %d blocks\n",
 120                        input.reserved_blocks);
 121                 printf("new group has %d free blocks\n",
 122                        new_fs->group_desc[i].bg_free_blocks_count);
 123                 printf("new group has %d free inodes (%d blocks)\n",
 124                        new_fs->group_desc[i].bg_free_inodes_count,
 125                        new_fs->inode_blocks_per_group);
 126                 printf("Adding group #%d\n", input.group);
 127 #endif
 128
 129                 if (ioctl(fd, EXT2_IOC_GROUP_ADD, &input) < 0) {
 130                         com_err(program_name, errno,
 131                                 _("While trying to add group #%d"),
 132                                 input.group);
 133                         exit(1);
 134                 }
 135         }
 136
 137         ext2fs_free(new_fs);
 138         close(fd);
 139
 140         return 0;
 141 }