online.c revision e39082e2e81641eb8021eb6ddc969731537c79a8
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 20extern char *program_name; 21 22#define MAX_32_NUM ((((unsigned long long) 1) << 32) - 1) 23 24#ifdef __linux__ 25static int parse_version_number(const char *s) 26{ 27 int major, minor, rev; 28 char *endptr; 29 const char *cp = s; 30 31 if (!s) 32 return 0; 33 major = strtol(cp, &endptr, 10); 34 if (cp == endptr || *endptr != '.') 35 return 0; 36 cp = endptr + 1; 37 minor = strtol(cp, &endptr, 10); 38 if (cp == endptr || *endptr != '.') 39 return 0; 40 cp = endptr + 1; 41 rev = strtol(cp, &endptr, 10); 42 if (cp == endptr) 43 return 0; 44 return ((((major * 256) + minor) * 256) + rev); 45} 46 47#define VERSION_CODE(a,b,c) (((a) << 16) + ((b) << 8) + (c)) 48 49#endif 50 51errcode_t online_resize_fs(ext2_filsys fs, const char *mtpt, 52 blk64_t *new_size, int flags EXT2FS_ATTR((unused))) 53{ 54#ifdef __linux__ 55 struct ext2_new_group_input input; 56 struct ext4_new_group_input input64; 57 struct ext2_super_block *sb = fs->super; 58 unsigned long new_desc_blocks; 59 ext2_filsys new_fs; 60 errcode_t retval; 61 double percent; 62 dgrp_t i; 63 blk_t size; 64 int fd, overhead; 65 int use_old_ioctl = 1; 66 int no_meta_bg_resize = 0; 67 int no_resize_ioctl = 0; 68 69 if (getenv("RESIZE2FS_KERNEL_VERSION")) { 70 char *version_to_emulate = getenv("RESIZE2FS_KERNEL_VERSION"); 71 int kvers = parse_version_number(version_to_emulate); 72 73 if (kvers < VERSION_CODE(3, 7, 0)) 74 no_meta_bg_resize = 1; 75 if (kvers < VERSION_CODE(3, 3, 0)) 76 no_resize_ioctl = 1; 77 } 78 79 printf(_("Filesystem at %s is mounted on %s; " 80 "on-line resizing required\n"), fs->device_name, mtpt); 81 82 if (*new_size < ext2fs_blocks_count(sb)) { 83 com_err(program_name, 0, _("On-line shrinking not supported")); 84 exit(1); 85 } 86 87 /* 88 * If the number of descriptor blocks is going to increase, 89 * the on-line resizing inode must be present. 90 */ 91 new_desc_blocks = ext2fs_div_ceil( 92 ext2fs_div64_ceil(*new_size - 93 fs->super->s_first_data_block, 94 EXT2_BLOCKS_PER_GROUP(fs->super)), 95 EXT2_DESC_PER_BLOCK(fs->super)); 96 printf("old_desc_blocks = %lu, new_desc_blocks = %lu\n", 97 fs->desc_blocks, new_desc_blocks); 98 99 /* 100 * Do error checking to make sure the resize will be successful. 101 */ 102 if ((access("/sys/fs/ext4/features/meta_bg_resize", R_OK) != 0) || 103 no_meta_bg_resize) { 104 if (!EXT2_HAS_COMPAT_FEATURE(fs->super, 105 EXT2_FEATURE_COMPAT_RESIZE_INODE) && 106 (new_desc_blocks != fs->desc_blocks)) { 107 com_err(program_name, 0, 108 _("Filesystem does not support online resizing")); 109 exit(1); 110 } 111 112 if (EXT2_HAS_COMPAT_FEATURE(fs->super, 113 EXT2_FEATURE_COMPAT_RESIZE_INODE) && 114 new_desc_blocks > (fs->desc_blocks + 115 fs->super->s_reserved_gdt_blocks)) { 116 com_err(program_name, 0, 117 _("Not enough reserved gdt blocks for resizing")); 118 exit(1); 119 } 120 121 if ((ext2fs_blocks_count(sb) > MAX_32_NUM) || 122 (*new_size > MAX_32_NUM)) { 123 com_err(program_name, 0, 124 _("Kernel does not support resizing a file system this large")); 125 exit(1); 126 } 127 } 128 129 fd = open(mtpt, O_RDONLY); 130 if (fd < 0) { 131 com_err(program_name, errno, 132 _("while trying to open mountpoint %s"), mtpt); 133 exit(1); 134 } 135 136 if (no_resize_ioctl) { 137 printf(_("Old resize interface requested.\n")); 138 } else if (ioctl(fd, EXT4_IOC_RESIZE_FS, new_size)) { 139 /* 140 * If kernel does not support EXT4_IOC_RESIZE_FS, use the 141 * old online resize. Note that the old approach does not 142 * handle >32 bit file systems 143 * 144 * Sigh, if we are running a 32-bit binary on a 64-bit 145 * kernel (which happens all the time on the MIPS 146 * architecture in Debian, but can happen on other CPU 147 * architectures as well) we will get EINVAL returned 148 * when an ioctl doesn't exist, at least up to Linux 149 * 3.1. See compat_sys_ioctl() in fs/compat_ioctl.c 150 * in the kernel sources. This is probably a kernel 151 * bug, but work around it here. 152 */ 153 if ((errno != ENOTTY) && (errno != EINVAL)) { 154 if (errno == EPERM) 155 com_err(program_name, 0, 156 _("Permission denied to resize filesystem")); 157 else 158 com_err(program_name, errno, 159 _("While checking for on-line resizing " 160 "support")); 161 exit(1); 162 } 163 } else { 164 close(fd); 165 return 0; 166 } 167 168 size = ext2fs_blocks_count(sb); 169 170 if (ioctl(fd, EXT2_IOC_GROUP_EXTEND, &size)) { 171 if (errno == EPERM) 172 com_err(program_name, 0, 173 _("Permission denied to resize filesystem")); 174 else if (errno == ENOTTY) 175 com_err(program_name, 0, 176 _("Kernel does not support online resizing")); 177 else 178 com_err(program_name, errno, 179 _("While checking for on-line resizing support")); 180 exit(1); 181 } 182 183 percent = (ext2fs_r_blocks_count(sb) * 100.0) / 184 ext2fs_blocks_count(sb); 185 186 retval = ext2fs_read_bitmaps(fs); 187 if (retval) { 188 close(fd); 189 return retval; 190 } 191 192 retval = ext2fs_dup_handle(fs, &new_fs); 193 if (retval) { 194 close(fd); 195 return retval; 196 } 197 198 /* The current method of adding one block group at a time to a 199 * mounted filesystem means it is impossible to accomodate the 200 * flex_bg allocation method of placing the metadata together 201 * in a single block group. For now we "fix" this issue by 202 * using the traditional layout for new block groups, where 203 * each block group is self-contained and contains its own 204 * bitmap blocks and inode tables. This means we don't get 205 * the layout advantages of flex_bg in the new block groups, 206 * but at least it allows on-line resizing to function. 207 */ 208 new_fs->super->s_feature_incompat &= ~EXT4_FEATURE_INCOMPAT_FLEX_BG; 209 retval = adjust_fs_info(new_fs, fs, 0, *new_size); 210 if (retval) { 211 close(fd); 212 return retval; 213 } 214 215 printf(_("Performing an on-line resize of %s to %llu (%dk) blocks.\n"), 216 fs->device_name, *new_size, fs->blocksize / 1024); 217 218 size = fs->group_desc_count * sb->s_blocks_per_group + 219 sb->s_first_data_block; 220 if (size > *new_size) 221 size = *new_size; 222 223 if (ioctl(fd, EXT2_IOC_GROUP_EXTEND, &size)) { 224 com_err(program_name, errno, 225 _("While trying to extend the last group")); 226 exit(1); 227 } 228 229 for (i = fs->group_desc_count; 230 i < new_fs->group_desc_count; i++) { 231 232 overhead = (int) (2 + new_fs->inode_blocks_per_group); 233 234 if (ext2fs_bg_has_super(new_fs, new_fs->group_desc_count - 1)) 235 overhead += 1 + new_fs->desc_blocks + 236 new_fs->super->s_reserved_gdt_blocks; 237 238 input.group = i; 239 input.block_bitmap = ext2fs_block_bitmap_loc(new_fs, i); 240 input.inode_bitmap = ext2fs_inode_bitmap_loc(new_fs, i); 241 input.inode_table = ext2fs_inode_table_loc(new_fs, i); 242 input.blocks_count = ext2fs_group_blocks_count(new_fs, i); 243 input.reserved_blocks = (blk_t) (percent * input.blocks_count 244 / 100.0); 245 246#if 0 247 printf("new block bitmap is at 0x%04x\n", input.block_bitmap); 248 printf("new inode bitmap is at 0x%04x\n", input.inode_bitmap); 249 printf("new inode table is at 0x%04x-0x%04x\n", 250 input.inode_table, 251 input.inode_table + new_fs->inode_blocks_per_group-1); 252 printf("new group has %u blocks\n", input.blocks_count); 253 printf("new group will reserve %d blocks\n", 254 input.reserved_blocks); 255 printf("new group has %d free blocks\n", 256 ext2fs_bg_free_blocks_count(new_fs, i), 257 printf("new group has %d free inodes (%d blocks)\n", 258 ext2fs_bg_free_inodes_count(new_fs, i), 259 new_fs->inode_blocks_per_group); 260 printf("Adding group #%d\n", input.group); 261#endif 262 263 if (use_old_ioctl && 264 ioctl(fd, EXT2_IOC_GROUP_ADD, &input) == 0) 265 continue; 266 else 267 use_old_ioctl = 0; 268 269 input64.group = input.group; 270 input64.block_bitmap = input.block_bitmap; 271 input64.inode_bitmap = input.inode_bitmap; 272 input64.inode_table = input.inode_table; 273 input64.blocks_count = input.blocks_count; 274 input64.reserved_blocks = input.reserved_blocks; 275 input64.unused = input.unused; 276 277 if (ioctl(fd, EXT4_IOC_GROUP_ADD, &input64) < 0) { 278 com_err(program_name, errno, 279 _("While trying to add group #%d"), 280 input.group); 281 exit(1); 282 } 283 } 284 285 ext2fs_free(new_fs); 286 close(fd); 287 288 return 0; 289#else 290 printf(_("Filesystem at %s is mounted on %s, and on-line resizing is " 291 "not supported on this system.\n"), fs->device_name, mtpt); 292 exit(1); 293#endif 294} 295