online.c revision a6ce1349539f866334ef3d5758bc2ee44a454acd
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 19extern char *program_name; 20 21errcode_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} 195