Theodore Ts'o | 24b2c7a | 1997-06-07 20:42:58 +0000 | [diff] [blame] | 1 | /* |
| 2 | * resize2fs.c --- ext2 main routine |
| 3 | * |
| 4 | * Copyright (C) 1997 Theodore Ts'o |
| 5 | * |
| 6 | * %Begin-Header% |
| 7 | * All rights reserved. |
| 8 | * %End-Header% |
| 9 | */ |
| 10 | |
| 11 | #include "resize2fs.h" |
| 12 | |
| 13 | /* |
| 14 | * This routine adjusts the superblock and other data structures... |
| 15 | */ |
| 16 | static errcode_t adjust_superblock(ext2_resize_t rfs, blk_t new_size) |
| 17 | { |
| 18 | ext2_filsys fs; |
| 19 | int overhead = 0; |
| 20 | int rem; |
| 21 | errcode_t retval; |
| 22 | ino_t real_end; |
| 23 | blk_t blk, group_block; |
Theodore Ts'o | 1e1da29 | 1997-06-09 14:51:29 +0000 | [diff] [blame^] | 24 | unsigned long i, j; |
Theodore Ts'o | 24b2c7a | 1997-06-07 20:42:58 +0000 | [diff] [blame] | 25 | struct ext2_group_desc *new; |
Theodore Ts'o | 1e1da29 | 1997-06-09 14:51:29 +0000 | [diff] [blame^] | 26 | char *buf; |
| 27 | int old_numblocks, numblocks, adjblocks; |
Theodore Ts'o | 24b2c7a | 1997-06-07 20:42:58 +0000 | [diff] [blame] | 28 | |
| 29 | fs = rfs->new_fs; |
| 30 | fs->super->s_blocks_count = new_size; |
Theodore Ts'o | 1e1da29 | 1997-06-09 14:51:29 +0000 | [diff] [blame^] | 31 | ext2fs_mark_super_dirty(fs); |
| 32 | ext2fs_mark_bb_dirty(fs); |
| 33 | ext2fs_mark_ib_dirty(fs); |
Theodore Ts'o | 24b2c7a | 1997-06-07 20:42:58 +0000 | [diff] [blame] | 34 | |
| 35 | retry: |
| 36 | fs->group_desc_count = (fs->super->s_blocks_count - |
| 37 | fs->super->s_first_data_block + |
| 38 | EXT2_BLOCKS_PER_GROUP(fs->super) - 1) |
| 39 | / EXT2_BLOCKS_PER_GROUP(fs->super); |
| 40 | if (fs->group_desc_count == 0) |
| 41 | return EXT2_ET_TOOSMALL; |
| 42 | fs->desc_blocks = (fs->group_desc_count + |
| 43 | EXT2_DESC_PER_BLOCK(fs->super) - 1) |
| 44 | / EXT2_DESC_PER_BLOCK(fs->super); |
| 45 | |
| 46 | /* |
| 47 | * Overhead is the number of bookkeeping blocks per group. It |
| 48 | * includes the superblock backup, the group descriptor |
| 49 | * backups, the inode bitmap, the block bitmap, and the inode |
| 50 | * table. |
| 51 | * |
| 52 | * XXX Not all block groups need the descriptor blocks, but |
| 53 | * being clever is tricky... |
| 54 | */ |
| 55 | overhead = 3 + fs->desc_blocks + fs->inode_blocks_per_group; |
| 56 | |
| 57 | /* |
| 58 | * See if the last group is big enough to support the |
| 59 | * necessary data structures. If not, we need to get rid of |
| 60 | * it. |
| 61 | */ |
| 62 | rem = (fs->super->s_blocks_count - fs->super->s_first_data_block) % |
| 63 | fs->super->s_blocks_per_group; |
| 64 | if ((fs->group_desc_count == 1) && rem && (rem < overhead)) |
| 65 | return EXT2_ET_TOOSMALL; |
| 66 | if (rem && (rem < overhead+50)) { |
| 67 | fs->super->s_blocks_count -= rem; |
| 68 | goto retry; |
| 69 | } |
| 70 | /* |
| 71 | * Adjust the number of inodes |
| 72 | */ |
| 73 | fs->super->s_inodes_count = fs->super->s_inodes_per_group * |
| 74 | fs->group_desc_count; |
| 75 | |
| 76 | /* |
| 77 | * Adjust the number of free blocks |
| 78 | */ |
| 79 | blk = rfs->old_fs->super->s_blocks_count; |
| 80 | if (blk > fs->super->s_blocks_count) |
| 81 | fs->super->s_free_blocks_count -= |
| 82 | (blk - fs->super->s_blocks_count); |
| 83 | else |
| 84 | fs->super->s_free_blocks_count += |
| 85 | (fs->super->s_blocks_count - blk); |
| 86 | |
| 87 | /* |
| 88 | * Adjust the bitmaps for size |
| 89 | */ |
| 90 | retval = ext2fs_resize_inode_bitmap(fs->super->s_inodes_count, |
| 91 | fs->super->s_inodes_count, |
| 92 | fs->inode_map); |
| 93 | if (retval) |
| 94 | return retval; |
| 95 | |
| 96 | real_end = ((EXT2_BLOCKS_PER_GROUP(fs->super) |
| 97 | * fs->group_desc_count)) - 1 + |
| 98 | fs->super->s_first_data_block; |
| 99 | retval = ext2fs_resize_block_bitmap(fs->super->s_blocks_count-1, |
| 100 | real_end, fs->block_map); |
| 101 | |
| 102 | if (retval) |
| 103 | return retval; |
| 104 | |
| 105 | /* |
| 106 | * Reallocate the group descriptors as necessary. |
| 107 | */ |
| 108 | if (rfs->old_fs->desc_blocks != fs->desc_blocks) { |
| 109 | new = realloc(fs->group_desc, |
| 110 | fs->desc_blocks * fs->blocksize); |
| 111 | if (!new) |
| 112 | return ENOMEM; |
| 113 | fs->group_desc = new; |
| 114 | } |
Theodore Ts'o | 1e1da29 | 1997-06-09 14:51:29 +0000 | [diff] [blame^] | 115 | |
| 116 | /* |
| 117 | * Fix the count of the last (old) block group |
| 118 | */ |
| 119 | if (rfs->old_fs->group_desc_count > fs->group_desc_count) |
| 120 | return 0; |
| 121 | old_numblocks = (rfs->old_fs->super->s_blocks_count - |
| 122 | rfs->old_fs->super->s_first_data_block) % |
| 123 | rfs->old_fs->super->s_blocks_per_group; |
| 124 | if (!old_numblocks) |
| 125 | old_numblocks = rfs->old_fs->super->s_blocks_per_group; |
| 126 | if (rfs->old_fs->group_desc_count == fs->group_desc_count) { |
| 127 | numblocks = (rfs->new_fs->super->s_blocks_count - |
| 128 | rfs->new_fs->super->s_first_data_block) % |
| 129 | rfs->new_fs->super->s_blocks_per_group; |
| 130 | if (!numblocks) |
| 131 | numblocks = rfs->new_fs->super->s_blocks_per_group; |
| 132 | } else |
| 133 | numblocks = rfs->new_fs->super->s_blocks_per_group; |
| 134 | i = rfs->old_fs->group_desc_count - 1; |
| 135 | fs->group_desc[i].bg_free_blocks_count += (numblocks-old_numblocks); |
| 136 | |
| 137 | /* |
| 138 | * Initialize the new block group descriptors |
| 139 | */ |
| 140 | if (rfs->old_fs->group_desc_count >= fs->group_desc_count) |
| 141 | return 0; |
| 142 | buf = malloc(fs->blocksize); |
| 143 | if (!buf) |
| 144 | return ENOMEM; |
| 145 | memset(buf, 0, fs->blocksize); |
| 146 | group_block = fs->super->s_first_data_block + |
| 147 | rfs->old_fs->group_desc_count * fs->super->s_blocks_per_group; |
| 148 | for (i = rfs->old_fs->group_desc_count; |
| 149 | i < fs->group_desc_count; i++) { |
| 150 | memset(&fs->group_desc[i], 0, |
| 151 | sizeof(struct ext2_group_desc)); |
| 152 | adjblocks = 0; |
| 153 | |
| 154 | if (i == fs->group_desc_count-1) { |
| 155 | numblocks = (fs->super->s_blocks_count - |
| 156 | fs->super->s_first_data_block) % |
| 157 | fs->super->s_blocks_per_group; |
| 158 | if (!numblocks) |
| 159 | numblocks = fs->super->s_blocks_per_group; |
| 160 | } else |
| 161 | numblocks = fs->super->s_blocks_per_group; |
| 162 | |
| 163 | if (ext2fs_bg_has_super(fs, i)) { |
| 164 | for (j=0; j < fs->desc_blocks+1; j++) |
| 165 | ext2fs_mark_block_bitmap(fs->block_map, |
| 166 | group_block + j); |
| 167 | adjblocks = 1 + fs->desc_blocks; |
Theodore Ts'o | 24b2c7a | 1997-06-07 20:42:58 +0000 | [diff] [blame] | 168 | } |
Theodore Ts'o | 1e1da29 | 1997-06-09 14:51:29 +0000 | [diff] [blame^] | 169 | adjblocks += 2 + fs->inode_blocks_per_group; |
| 170 | |
| 171 | numblocks -= adjblocks; |
| 172 | fs->super->s_free_blocks_count -= adjblocks; |
| 173 | fs->super->s_free_inodes_count += |
| 174 | fs->super->s_inodes_per_group; |
| 175 | fs->group_desc[i].bg_free_blocks_count = numblocks; |
| 176 | fs->group_desc[i].bg_free_inodes_count = |
| 177 | fs->super->s_inodes_per_group; |
| 178 | fs->group_desc[i].bg_used_dirs_count = 0; |
| 179 | |
| 180 | retval = ext2fs_allocate_group_table(fs, i, 0); |
| 181 | if (retval) |
| 182 | return retval; |
| 183 | |
| 184 | for (blk=fs->group_desc[i].bg_inode_table, j=0; |
| 185 | j < fs->inode_blocks_per_group; |
| 186 | blk++, j++) { |
| 187 | retval = io_channel_write_blk(fs->io, blk, 1, buf); |
| 188 | if (retval) |
| 189 | return retval; |
| 190 | } |
| 191 | group_block += fs->super->s_blocks_per_group; |
Theodore Ts'o | 24b2c7a | 1997-06-07 20:42:58 +0000 | [diff] [blame] | 192 | } |
Theodore Ts'o | 24b2c7a | 1997-06-07 20:42:58 +0000 | [diff] [blame] | 193 | return 0; |
| 194 | } |
| 195 | |
| 196 | /* |
Theodore Ts'o | 24b2c7a | 1997-06-07 20:42:58 +0000 | [diff] [blame] | 197 | * This routine marks and unmarks reserved blocks in the new block |
| 198 | * bitmap. It also determines which blocks need to be moved and |
| 199 | * places this information into the move_blocks bitmap. |
| 200 | */ |
| 201 | static errcode_t determine_relocations(ext2_resize_t rfs) |
| 202 | { |
Theodore Ts'o | 1e1da29 | 1997-06-09 14:51:29 +0000 | [diff] [blame^] | 203 | int i, j; |
Theodore Ts'o | 24b2c7a | 1997-06-07 20:42:58 +0000 | [diff] [blame] | 204 | blk_t blk, group_blk; |
| 205 | unsigned long old_blocks, new_blocks; |
| 206 | errcode_t retval; |
Theodore Ts'o | 1e1da29 | 1997-06-09 14:51:29 +0000 | [diff] [blame^] | 207 | ext2_filsys fs = rfs->new_fs; |
Theodore Ts'o | 24b2c7a | 1997-06-07 20:42:58 +0000 | [diff] [blame] | 208 | |
| 209 | retval = ext2fs_allocate_block_bitmap(rfs->old_fs, |
| 210 | "blocks to be moved", |
Theodore Ts'o | 1e1da29 | 1997-06-09 14:51:29 +0000 | [diff] [blame^] | 211 | &rfs->reserve_blocks); |
Theodore Ts'o | 24b2c7a | 1997-06-07 20:42:58 +0000 | [diff] [blame] | 212 | if (retval) |
| 213 | return retval; |
Theodore Ts'o | 1e1da29 | 1997-06-09 14:51:29 +0000 | [diff] [blame^] | 214 | |
| 215 | /* |
| 216 | * If we're shrinking the filesystem, we need to move all of |
| 217 | * the blocks that don't fit any more |
| 218 | */ |
| 219 | for (blk = fs->super->s_blocks_count; |
| 220 | blk < rfs->old_fs->super->s_blocks_count; blk++) { |
| 221 | if (ext2fs_test_block_bitmap(rfs->old_fs->block_map, blk)) |
| 222 | rfs->needed_blocks++; |
| 223 | ext2fs_mark_block_bitmap(rfs->reserve_blocks, blk); |
| 224 | } |
Theodore Ts'o | 24b2c7a | 1997-06-07 20:42:58 +0000 | [diff] [blame] | 225 | |
| 226 | old_blocks = rfs->old_fs->desc_blocks; |
Theodore Ts'o | 1e1da29 | 1997-06-09 14:51:29 +0000 | [diff] [blame^] | 227 | new_blocks = fs->desc_blocks; |
| 228 | |
| 229 | if (old_blocks == new_blocks) |
| 230 | return 0; |
Theodore Ts'o | 24b2c7a | 1997-06-07 20:42:58 +0000 | [diff] [blame] | 231 | |
| 232 | group_blk = rfs->old_fs->super->s_first_data_block; |
| 233 | /* |
| 234 | * If we're reducing the number of descriptor blocks, this |
| 235 | * makes life easy. :-) We just have to mark some extra |
| 236 | * blocks as free. |
| 237 | */ |
| 238 | if (old_blocks > new_blocks) { |
Theodore Ts'o | 1e1da29 | 1997-06-09 14:51:29 +0000 | [diff] [blame^] | 239 | for (i = 0; i < fs->group_desc_count; i++) { |
| 240 | if (!ext2fs_bg_has_super(fs, i)) { |
| 241 | group_blk += fs->super->s_blocks_per_group; |
Theodore Ts'o | 24b2c7a | 1997-06-07 20:42:58 +0000 | [diff] [blame] | 242 | continue; |
| 243 | } |
| 244 | for (blk = group_blk+1+old_blocks; |
| 245 | blk < group_blk+1+new_blocks; blk++) |
Theodore Ts'o | 1e1da29 | 1997-06-09 14:51:29 +0000 | [diff] [blame^] | 246 | ext2fs_unmark_block_bitmap(fs->block_map, |
Theodore Ts'o | 24b2c7a | 1997-06-07 20:42:58 +0000 | [diff] [blame] | 247 | blk); |
Theodore Ts'o | 1e1da29 | 1997-06-09 14:51:29 +0000 | [diff] [blame^] | 248 | group_blk += fs->super->s_blocks_per_group; |
Theodore Ts'o | 24b2c7a | 1997-06-07 20:42:58 +0000 | [diff] [blame] | 249 | } |
Theodore Ts'o | 1e1da29 | 1997-06-09 14:51:29 +0000 | [diff] [blame^] | 250 | return 0; |
Theodore Ts'o | 24b2c7a | 1997-06-07 20:42:58 +0000 | [diff] [blame] | 251 | } |
| 252 | /* |
| 253 | * If we're increasing the number of descriptor blocks, life |
Theodore Ts'o | 1e1da29 | 1997-06-09 14:51:29 +0000 | [diff] [blame^] | 254 | * gets interesting.... |
Theodore Ts'o | 24b2c7a | 1997-06-07 20:42:58 +0000 | [diff] [blame] | 255 | */ |
Theodore Ts'o | 1e1da29 | 1997-06-09 14:51:29 +0000 | [diff] [blame^] | 256 | for (i = 0; i < fs->group_desc_count; i++) { |
| 257 | if (!ext2fs_bg_has_super(fs, i)) |
| 258 | goto next_group; |
Theodore Ts'o | 24b2c7a | 1997-06-07 20:42:58 +0000 | [diff] [blame] | 259 | |
Theodore Ts'o | 1e1da29 | 1997-06-09 14:51:29 +0000 | [diff] [blame^] | 260 | for (blk = group_blk; |
| 261 | blk < group_blk + 1 + new_blocks; blk++) { |
| 262 | ext2fs_mark_block_bitmap(rfs->reserve_blocks, blk); |
| 263 | ext2fs_mark_block_bitmap(fs->block_map, blk); |
| 264 | |
| 265 | /* |
| 266 | * Check to see if we overlap with the inode |
| 267 | * or block bitmap |
| 268 | */ |
| 269 | if (blk == fs->group_desc[i].bg_inode_bitmap) |
| 270 | fs->group_desc[i].bg_block_bitmap = 0; |
| 271 | if (blk == fs->group_desc[i].bg_inode_bitmap) |
| 272 | fs->group_desc[i].bg_inode_bitmap = 0; |
| 273 | |
| 274 | /* |
| 275 | * Check to see if we overlap with the inode |
| 276 | * table |
| 277 | */ |
| 278 | if (blk < fs->group_desc[i].bg_inode_table) |
| 279 | continue; |
| 280 | if (blk >= (fs->group_desc[i].bg_inode_table + |
| 281 | fs->inode_blocks_per_group)) |
| 282 | continue; |
| 283 | fs->group_desc[i].bg_inode_table = 0; |
| 284 | blk = fs->group_desc[i].bg_inode_table + |
| 285 | fs->inode_blocks_per_group - 1; |
| 286 | } |
| 287 | if (fs->group_desc[i].bg_inode_table && |
| 288 | fs->group_desc[i].bg_inode_bitmap && |
| 289 | fs->group_desc[i].bg_block_bitmap) |
| 290 | goto next_group; |
| 291 | |
| 292 | /* |
| 293 | * Allocate the missing bitmap and inode table |
| 294 | * structures, passing in rfs->reserve_blocks to |
| 295 | * prevent a conflict. |
| 296 | */ |
| 297 | if (fs->group_desc[i].bg_block_bitmap) |
| 298 | ext2fs_mark_block_bitmap(rfs->reserve_blocks, |
| 299 | fs->group_desc[i].bg_block_bitmap); |
| 300 | if (fs->group_desc[i].bg_inode_bitmap) |
| 301 | ext2fs_mark_block_bitmap(rfs->reserve_blocks, |
| 302 | fs->group_desc[i].bg_inode_bitmap); |
| 303 | if (fs->group_desc[i].bg_inode_table) |
| 304 | for (blk = fs->group_desc[i].bg_inode_table, j=0; |
| 305 | j < fs->inode_blocks_per_group ; j++, blk++) |
| 306 | ext2fs_mark_block_bitmap(rfs->reserve_blocks, |
| 307 | blk); |
| 308 | |
| 309 | retval = ext2fs_allocate_group_table(fs, i, |
| 310 | rfs->reserve_blocks); |
| 311 | if (retval) |
| 312 | return retval; |
| 313 | |
| 314 | /* |
| 315 | * Now make sure these blocks are reserved in the new |
| 316 | * block bitmap |
| 317 | */ |
| 318 | ext2fs_mark_block_bitmap(fs->block_map, |
| 319 | fs->group_desc[i].bg_block_bitmap); |
| 320 | ext2fs_mark_block_bitmap(fs->block_map, |
| 321 | fs->group_desc[i].bg_inode_bitmap); |
| 322 | |
| 323 | for (blk = fs->group_desc[i].bg_inode_table, j=0; |
| 324 | j < fs->inode_blocks_per_group ; j++, blk++) |
| 325 | ext2fs_mark_block_bitmap(fs->block_map, blk); |
| 326 | |
| 327 | /* |
| 328 | * Mark the inode tables which will need to move, and |
| 329 | * restore the old inode table location (for now) |
| 330 | */ |
| 331 | if (fs->group_desc[i].bg_inode_table != |
| 332 | rfs->old_fs->group_desc[i].bg_inode_table) { |
| 333 | rfs->move_itable[i] = fs->group_desc[i].bg_inode_table; |
| 334 | fs->group_desc[i].bg_inode_table = |
| 335 | rfs->old_fs->group_desc[i].bg_inode_table; |
| 336 | } |
| 337 | |
| 338 | next_group: |
| 339 | group_blk += rfs->new_fs->super->s_blocks_per_group; |
Theodore Ts'o | 24b2c7a | 1997-06-07 20:42:58 +0000 | [diff] [blame] | 340 | } |
| 341 | } |
| 342 | |
| 343 | |
Theodore Ts'o | 24b2c7a | 1997-06-07 20:42:58 +0000 | [diff] [blame] | 344 | /* |
| 345 | * This is the top-level routine which does the dirty deed.... |
| 346 | */ |
| 347 | errcode_t resize_fs(ext2_filsys fs, blk_t new_size) |
| 348 | { |
| 349 | ext2_resize_t rfs; |
| 350 | errcode_t retval; |
| 351 | |
Theodore Ts'o | 1e1da29 | 1997-06-09 14:51:29 +0000 | [diff] [blame^] | 352 | retval = ext2fs_read_bitmaps(fs); |
| 353 | if (retval) |
| 354 | return retval; |
| 355 | |
Theodore Ts'o | 24b2c7a | 1997-06-07 20:42:58 +0000 | [diff] [blame] | 356 | /* |
Theodore Ts'o | 1e1da29 | 1997-06-09 14:51:29 +0000 | [diff] [blame^] | 357 | * Create the data structure |
Theodore Ts'o | 24b2c7a | 1997-06-07 20:42:58 +0000 | [diff] [blame] | 358 | */ |
| 359 | rfs = malloc(sizeof(struct ext2_resize_struct)); |
| 360 | if (!rfs) |
| 361 | return ENOMEM; |
| 362 | memset(rfs, 0, sizeof(struct ext2_resize_struct)); |
| 363 | |
Theodore Ts'o | 1e1da29 | 1997-06-09 14:51:29 +0000 | [diff] [blame^] | 364 | rfs->move_itable = malloc(sizeof(blk_t) * fs->group_desc_count); |
| 365 | if (!rfs->move_itable) { |
| 366 | retval = ENOMEM; |
| 367 | goto errout; |
| 368 | } |
| 369 | memset(rfs->move_itable, 0, sizeof(blk_t) * fs->group_desc_count); |
| 370 | |
Theodore Ts'o | 24b2c7a | 1997-06-07 20:42:58 +0000 | [diff] [blame] | 371 | rfs->old_fs = fs; |
| 372 | retval = ext2fs_dup_handle(fs, &rfs->new_fs); |
Theodore Ts'o | 1e1da29 | 1997-06-09 14:51:29 +0000 | [diff] [blame^] | 373 | if (retval) |
| 374 | goto errout; |
| 375 | |
Theodore Ts'o | 24b2c7a | 1997-06-07 20:42:58 +0000 | [diff] [blame] | 376 | retval = adjust_superblock(rfs, new_size); |
| 377 | if (retval) |
| 378 | goto errout; |
Theodore Ts'o | 1e1da29 | 1997-06-09 14:51:29 +0000 | [diff] [blame^] | 379 | |
| 380 | retval = determine_relocations(rfs); |
| 381 | if (retval) |
| 382 | goto errout; |
| 383 | |
| 384 | printf("\nOld superblock:\n"); |
| 385 | list_super(rfs->old_fs->super); |
| 386 | printf("\n\nNew superblock:\n"); |
| 387 | list_super(rfs->new_fs->super); |
| 388 | printf("\n"); |
| 389 | |
| 390 | retval = ext2fs_move_blocks(rfs->old_fs, rfs->reserve_blocks, |
| 391 | EXT2_BMOVE_GET_DBLIST); |
| 392 | |
| 393 | retval = ext2fs_close(rfs->new_fs); |
| 394 | if (retval) |
| 395 | return retval; |
| 396 | |
| 397 | ext2fs_free(rfs->old_fs); |
Theodore Ts'o | 24b2c7a | 1997-06-07 20:42:58 +0000 | [diff] [blame] | 398 | |
| 399 | return 0; |
| 400 | |
| 401 | errout: |
Theodore Ts'o | 1e1da29 | 1997-06-09 14:51:29 +0000 | [diff] [blame^] | 402 | if (rfs->move_itable) |
| 403 | free(rfs->move_itable); |
| 404 | if (rfs->new_fs) |
| 405 | ext2fs_free(rfs->new_fs); |
Theodore Ts'o | 24b2c7a | 1997-06-07 20:42:58 +0000 | [diff] [blame] | 406 | free(rfs); |
| 407 | return retval; |
| 408 | } |
| 409 | |