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 #ifdef __linux__ 25 static 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 51 errcode_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 if (ext2fs_has_feature_sparse_super2(fs->super) && 80 (access("/sys/fs/ext4/features/sparse_super2", R_OK) != 0)) { 81 com_err(program_name, 0, _("kernel does not support online " 82 "resize with sparse_super2")); 83 exit(1); 84 } 85 86 printf(_("Filesystem at %s is mounted on %s; " 87 "on-line resizing required\n"), fs->device_name, mtpt); 88 89 if (*new_size < ext2fs_blocks_count(sb)) { 90 com_err(program_name, 0, _("On-line shrinking not supported")); 91 exit(1); 92 } 93 94 /* 95 * If the number of descriptor blocks is going to increase, 96 * the on-line resizing inode must be present. 97 */ 98 new_desc_blocks = ext2fs_div_ceil( 99 ext2fs_div64_ceil(*new_size - 100 fs->super->s_first_data_block, 101 EXT2_BLOCKS_PER_GROUP(fs->super)), 102 EXT2_DESC_PER_BLOCK(fs->super)); 103 printf("old_desc_blocks = %lu, new_desc_blocks = %lu\n", 104 fs->desc_blocks, new_desc_blocks); 105 106 /* 107 * Do error checking to make sure the resize will be successful. 108 */ 109 if ((access("/sys/fs/ext4/features/meta_bg_resize", R_OK) != 0) || 110 no_meta_bg_resize) { 111 if (!ext2fs_has_feature_resize_inode(fs->super) && 112 (new_desc_blocks != fs->desc_blocks)) { 113 com_err(program_name, 0, 114 _("Filesystem does not support online resizing")); 115 exit(1); 116 } 117 118 if (ext2fs_has_feature_resize_inode(fs->super) && 119 new_desc_blocks > (fs->desc_blocks + 120 fs->super->s_reserved_gdt_blocks)) { 121 com_err(program_name, 0, 122 _("Not enough reserved gdt blocks for resizing")); 123 exit(1); 124 } 125 126 if ((ext2fs_blocks_count(sb) > MAX_32_NUM) || 127 (*new_size > MAX_32_NUM)) { 128 com_err(program_name, 0, 129 _("Kernel does not support resizing a file system this large")); 130 exit(1); 131 } 132 } 133 134 fd = open(mtpt, O_RDONLY); 135 if (fd < 0) { 136 com_err(program_name, errno, 137 _("while trying to open mountpoint %s"), mtpt); 138 exit(1); 139 } 140 141 if (no_resize_ioctl) { 142 printf(_("Old resize interface requested.\n")); 143 } else if (ioctl(fd, EXT4_IOC_RESIZE_FS, new_size)) { 144 /* 145 * If kernel does not support EXT4_IOC_RESIZE_FS, use the 146 * old online resize. Note that the old approach does not 147 * handle >32 bit file systems 148 * 149 * Sigh, if we are running a 32-bit binary on a 64-bit 150 * kernel (which happens all the time on the MIPS 151 * architecture in Debian, but can happen on other CPU 152 * architectures as well) we will get EINVAL returned 153 * when an ioctl doesn't exist, at least up to Linux 154 * 3.1. See compat_sys_ioctl() in fs/compat_ioctl.c 155 * in the kernel sources. This is probably a kernel 156 * bug, but work around it here. 157 */ 158 if ((errno != ENOTTY) && (errno != EINVAL)) { 159 if (errno == EPERM) 160 com_err(program_name, 0, 161 _("Permission denied to resize filesystem")); 162 else 163 com_err(program_name, errno, 164 _("While checking for on-line resizing " 165 "support")); 166 exit(1); 167 } 168 } else { 169 close(fd); 170 return 0; 171 } 172 173 size = ext2fs_blocks_count(sb); 174 175 if (ioctl(fd, EXT2_IOC_GROUP_EXTEND, &size)) { 176 if (errno == EPERM) 177 com_err(program_name, 0, 178 _("Permission denied to resize filesystem")); 179 else if (errno == ENOTTY) 180 com_err(program_name, 0, 181 _("Kernel does not support online resizing")); 182 else 183 com_err(program_name, errno, 184 _("While checking for on-line resizing support")); 185 exit(1); 186 } 187 188 percent = (ext2fs_r_blocks_count(sb) * 100.0) / 189 ext2fs_blocks_count(sb); 190 191 retval = ext2fs_read_bitmaps(fs); 192 if (retval) { 193 close(fd); 194 return retval; 195 } 196 197 retval = ext2fs_dup_handle(fs, &new_fs); 198 if (retval) { 199 close(fd); 200 return retval; 201 } 202 203 /* The current method of adding one block group at a time to a 204 * mounted filesystem means it is impossible to accomodate the 205 * flex_bg allocation method of placing the metadata together 206 * in a single block group. For now we "fix" this issue by 207 * using the traditional layout for new block groups, where 208 * each block group is self-contained and contains its own 209 * bitmap blocks and inode tables. This means we don't get 210 * the layout advantages of flex_bg in the new block groups, 211 * but at least it allows on-line resizing to function. 212 */ 213 ext2fs_clear_feature_flex_bg(new_fs->super); 214 retval = adjust_fs_info(new_fs, fs, 0, *new_size); 215 if (retval) { 216 close(fd); 217 return retval; 218 } 219 220 printf(_("Performing an on-line resize of %s to %llu (%dk) blocks.\n"), 221 fs->device_name, *new_size, fs->blocksize / 1024); 222 223 size = fs->group_desc_count * sb->s_blocks_per_group + 224 sb->s_first_data_block; 225 if (size > *new_size) 226 size = *new_size; 227 228 if (ioctl(fd, EXT2_IOC_GROUP_EXTEND, &size)) { 229 com_err(program_name, errno, 230 _("While trying to extend the last group")); 231 exit(1); 232 } 233 234 for (i = fs->group_desc_count; 235 i < new_fs->group_desc_count; i++) { 236 237 overhead = (int) (2 + new_fs->inode_blocks_per_group); 238 239 if (ext2fs_bg_has_super(new_fs, new_fs->group_desc_count - 1)) 240 overhead += 1 + new_fs->desc_blocks + 241 new_fs->super->s_reserved_gdt_blocks; 242 243 input.group = i; 244 input.block_bitmap = ext2fs_block_bitmap_loc(new_fs, i); 245 input.inode_bitmap = ext2fs_inode_bitmap_loc(new_fs, i); 246 input.inode_table = ext2fs_inode_table_loc(new_fs, i); 247 input.blocks_count = ext2fs_group_blocks_count(new_fs, i); 248 input.reserved_blocks = (blk_t) (percent * input.blocks_count 249 / 100.0); 250 251 #if 0 252 printf("new block bitmap is at 0x%04x\n", input.block_bitmap); 253 printf("new inode bitmap is at 0x%04x\n", input.inode_bitmap); 254 printf("new inode table is at 0x%04x-0x%04x\n", 255 input.inode_table, 256 input.inode_table + new_fs->inode_blocks_per_group-1); 257 printf("new group has %u blocks\n", input.blocks_count); 258 printf("new group will reserve %d blocks\n", 259 input.reserved_blocks); 260 printf("new group has %d free blocks\n", 261 ext2fs_bg_free_blocks_count(new_fs, i), 262 printf("new group has %d free inodes (%d blocks)\n", 263 ext2fs_bg_free_inodes_count(new_fs, i), 264 new_fs->inode_blocks_per_group); 265 printf("Adding group #%d\n", input.group); 266 #endif 267 268 if (use_old_ioctl && 269 ioctl(fd, EXT2_IOC_GROUP_ADD, &input) == 0) 270 continue; 271 else 272 use_old_ioctl = 0; 273 274 input64.group = input.group; 275 input64.block_bitmap = input.block_bitmap; 276 input64.inode_bitmap = input.inode_bitmap; 277 input64.inode_table = input.inode_table; 278 input64.blocks_count = input.blocks_count; 279 input64.reserved_blocks = input.reserved_blocks; 280 input64.unused = input.unused; 281 282 if (ioctl(fd, EXT4_IOC_GROUP_ADD, &input64) < 0) { 283 com_err(program_name, errno, 284 _("While trying to add group #%d"), 285 input.group); 286 exit(1); 287 } 288 } 289 290 ext2fs_free(new_fs); 291 close(fd); 292 293 return 0; 294 #else 295 printf(_("Filesystem at %s is mounted on %s, and on-line resizing is " 296 "not supported on this system.\n"), fs->device_name, mtpt); 297 exit(1); 298 #endif 299 } 300
