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 "config.h"
  13 #include "resize2fs.h"
  14 #ifdef HAVE_SYS_IOCTL_H
  15 #include <sys/ioctl.h>
  16 #endif
  17 #include <sys/stat.h>
  18 #include <fcntl.h>
  19
  20 extern char *program_name;
  21
  22 #define MAX_32_NUM ((((unsigned long long) 1) << 32) - 1)
  23
  24 errcode_t online_resize_fs(ext2_filsys fs, const char *mtpt,
  25                            blk64_t *new_size, int flags EXT2FS_ATTR((unused)))
  26 {
  27 #ifdef __linux__
  28         struct ext2_new_group_input input;
  29         struct ext4_new_group_input input64;
  30         struct ext2_super_block *sb = fs->super;
  31         unsigned long           new_desc_blocks;
  32         ext2_filsys             new_fs;
  33         errcode_t               retval;
  34         double                  percent;
  35         dgrp_t                  i;
  36         blk_t                   size;
  37         int                     fd, overhead;
  38         int                     use_old_ioctl = 1;
  39
  40         printf(_("Filesystem at %s is mounted on %s; "
  41                  "on-line resizing required\n"), fs->device_name, mtpt);
  42
  43         if (*new_size < ext2fs_blocks_count(sb)) {
  44                 com_err(program_name, 0, _("On-line shrinking not supported"));
  45                 exit(1);
  46         }
  47
  48         /*
  49          * If the number of descriptor blocks is going to increase,
  50          * the on-line resizing inode must be present.
  51          */
  52         new_desc_blocks = ext2fs_div_ceil(
  53                 ext2fs_div64_ceil(*new_size -
  54                                   fs->super->s_first_data_block,
  55                                   EXT2_BLOCKS_PER_GROUP(fs->super)),
  56                 EXT2_DESC_PER_BLOCK(fs->super));
  57         printf("old_desc_blocks = %lu, new_desc_blocks = %lu\n",
  58                fs->desc_blocks, new_desc_blocks);
  59         if (!(fs->super->s_feature_compat &
  60               EXT2_FEATURE_COMPAT_RESIZE_INODE) &&
  61             new_desc_blocks != fs->desc_blocks) {
  62                 com_err(program_name, 0,
  63                         _("Filesystem does not support online resizing"));
  64                 exit(1);
  65         }
  66
  67         fd = open(mtpt, O_RDONLY);
  68         if (fd < 0) {
  69                 com_err(program_name, errno,
  70                         _("while trying to open mountpoint %s"), mtpt);
  71                 exit(1);
  72         }
  73
  74         if (ioctl(fd, EXT4_IOC_RESIZE_FS, new_size)) {
  75                 if (errno != EINVAL) {
  76                         if (errno == EPERM)
  77                                 com_err(program_name, 0,
  78                                 _("Permission denied to resize filesystem"));
  79                         else
  80                                 com_err(program_name, errno,
  81                                 _("While checking for on-line resizing "
  82                                   "support"));
  83                         exit(1);
  84                 }
  85         } else {
  86                 close(fd);
  87                 return 0;
  88         }
  89
  90         if ((ext2fs_blocks_count(sb) > MAX_32_NUM) ||
  91             (*new_size > MAX_32_NUM)) {
  92                 com_err(program_name, 0,
  93                         _("Kernel does not resizing a file system this large"));
  94                 exit(1);
  95         }
  96         size = ext2fs_blocks_count(sb);
  97
  98         if (ioctl(fd, EXT2_IOC_GROUP_EXTEND, &size)) {
  99                 if (errno == EPERM)
 100                         com_err(program_name, 0,
 101                                 _("Permission denied to resize filesystem"));
 102                 else if (errno == ENOTTY)
 103                         com_err(program_name, 0,
 104                         _("Kernel does not support online resizing"));
 105                 else
 106                         com_err(program_name, errno,
 107                         _("While checking for on-line resizing support"));
 108                 exit(1);
 109         }
 110
 111         percent = (ext2fs_r_blocks_count(sb) * 100.0) /
 112                 ext2fs_blocks_count(sb);
 113
 114         retval = ext2fs_read_bitmaps(fs);
 115         if (retval)
 116                 return retval;
 117
 118         retval = ext2fs_dup_handle(fs, &new_fs);
 119         if (retval)
 120                 return retval;
 121
 122         /* The current method of adding one block group at a time to a
 123          * mounted filesystem means it is impossible to accomodate the
 124          * flex_bg allocation method of placing the metadata together
 125          * in a single block group.  For now we "fix" this issue by
 126          * using the traditional layout for new block groups, where
 127          * each block group is self-contained and contains its own
 128          * bitmap blocks and inode tables.  This means we don't get
 129          * the layout advantages of flex_bg in the new block groups,
 130          * but at least it allows on-line resizing to function.
 131          */
 132         new_fs->super->s_feature_incompat &= ~EXT4_FEATURE_INCOMPAT_FLEX_BG;
 133         retval = adjust_fs_info(new_fs, fs, 0, *new_size);
 134         if (retval)
 135                 return retval;
 136
 137         printf(_("Performing an on-line resize of %s to %llu (%dk) blocks.\n"),
 138                fs->device_name, *new_size, fs->blocksize / 1024);
 139
 140         size = fs->group_desc_count * sb->s_blocks_per_group +
 141                 sb->s_first_data_block;
 142         if (size > *new_size)
 143                 size = *new_size;
 144
 145         if (ioctl(fd, EXT2_IOC_GROUP_EXTEND, &size)) {
 146                 com_err(program_name, errno,
 147                         _("While trying to extend the last group"));
 148                 exit(1);
 149         }
 150
 151         for (i = fs->group_desc_count;
 152              i < new_fs->group_desc_count; i++) {
 153
 154                 overhead = (int) (2 + new_fs->inode_blocks_per_group);
 155
 156                 if (ext2fs_bg_has_super(new_fs, new_fs->group_desc_count - 1))
 157                         overhead += 1 + new_fs->desc_blocks +
 158                                 new_fs->super->s_reserved_gdt_blocks;
 159
 160                 input.group = i;
 161                 input.block_bitmap = ext2fs_block_bitmap_loc(new_fs, i);
 162                 input.inode_bitmap = ext2fs_inode_bitmap_loc(new_fs, i);
 163                 input.inode_table = ext2fs_inode_table_loc(new_fs, i);
 164                 input.blocks_count = ext2fs_group_blocks_count(new_fs, i);
 165                 input.reserved_blocks = (blk_t) (percent * input.blocks_count
 166                                                  / 100.0);
 167
 168 #if 0
 169                 printf("new block bitmap is at 0x%04x\n", input.block_bitmap);
 170                 printf("new inode bitmap is at 0x%04x\n", input.inode_bitmap);
 171                 printf("new inode table is at 0x%04x-0x%04x\n",
 172                        input.inode_table,
 173                        input.inode_table + new_fs->inode_blocks_per_group-1);
 174                 printf("new group has %u blocks\n", input.blocks_count);
 175                 printf("new group will reserve %d blocks\n",
 176                        input.reserved_blocks);
 177                 printf("new group has %d free blocks\n",
 178                        ext2fs_bg_free_blocks_count(new_fs, i),
 179                 printf("new group has %d free inodes (%d blocks)\n",
 180                        ext2fs_bg_free_inodes_count(new_fs, i),
 181                        new_fs->inode_blocks_per_group);
 182                 printf("Adding group #%d\n", input.group);
 183 #endif
 184
 185                 if (use_old_ioctl &&
 186                     ioctl(fd, EXT2_IOC_GROUP_ADD, &input) == 0)
 187                         continue;
 188                 else
 189                         use_old_ioctl = 0;
 190
 191                 input64.group = input.group;
 192                 input64.block_bitmap = input.block_bitmap;
 193                 input64.inode_bitmap = input.inode_bitmap;
 194                 input64.inode_table = input.inode_table;
 195                 input64.blocks_count = input.blocks_count;
 196                 input64.reserved_blocks = input.reserved_blocks;
 197                 input64.unused = input.unused;
 198
 199                 if (ioctl(fd, EXT4_IOC_GROUP_ADD, &input64) < 0) {
 200                         com_err(program_name, errno,
 201                                 _("While trying to add group #%d"),
 202                                 input.group);
 203                         exit(1);
 204                 }
 205         }
 206
 207         ext2fs_free(new_fs);
 208         close(fd);
 209
 210         return 0;
 211 #else
 212         printf(_("Filesystem at %s is mounted on %s, and on-line resizing is "
 213                  "not supported on this system.\n"), fs->device_name, mtpt);
 214         exit(1);
 215 #endif
 216 }