1 /* 2 * linux/fs/ext4/resize.c 3 * 4 * Support for resizing an ext4 filesystem while it is mounted. 5 * 6 * Copyright (C) 2001, 2002 Andreas Dilger <adilger@clusterfs.com> 7 * 8 * This could probably be made into a module, because it is not often in use. 9 */ 10 11 12 #define EXT4FS_DEBUG 13 14 #include <linux/errno.h> 15 #include <linux/slab.h> 16 17 #include "ext4_jbd2.h" 18 19 int ext4_resize_begin(struct super_block *sb) 20 { 21 int ret = 0; 22 23 if (!capable(CAP_SYS_RESOURCE)) 24 return -EPERM; 25 26 /* 27 * If we are not using the primary superblock/GDT copy don't resize, 28 * because the user tools have no way of handling this. Probably a 29 * bad time to do it anyways. 30 */ 31 if (EXT4_SB(sb)->s_sbh->b_blocknr != 32 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block)) { 33 ext4_warning(sb, "won't resize using backup superblock at %llu", 34 (unsigned long long)EXT4_SB(sb)->s_sbh->b_blocknr); 35 return -EPERM; 36 } 37 38 /* 39 * We are not allowed to do online-resizing on a filesystem mounted 40 * with error, because it can destroy the filesystem easily. 41 */ 42 if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) { 43 ext4_warning(sb, "There are errors in the filesystem, " 44 "so online resizing is not allowed"); 45 return -EPERM; 46 } 47 48 if (test_and_set_bit_lock(EXT4_FLAGS_RESIZING, 49 &EXT4_SB(sb)->s_ext4_flags)) 50 ret = -EBUSY; 51 52 return ret; 53 } 54 55 void ext4_resize_end(struct super_block *sb) 56 { 57 clear_bit_unlock(EXT4_FLAGS_RESIZING, &EXT4_SB(sb)->s_ext4_flags); 58 smp_mb__after_atomic(); 59 } 60 61 static ext4_group_t ext4_meta_bg_first_group(struct super_block *sb, 62 ext4_group_t group) { 63 return (group >> EXT4_DESC_PER_BLOCK_BITS(sb)) << 64 EXT4_DESC_PER_BLOCK_BITS(sb); 65 } 66 67 static ext4_fsblk_t ext4_meta_bg_first_block_no(struct super_block *sb, 68 ext4_group_t group) { 69 group = ext4_meta_bg_first_group(sb, group); 70 return ext4_group_first_block_no(sb, group); 71 } 72 73 static ext4_grpblk_t ext4_group_overhead_blocks(struct super_block *sb, 74 ext4_group_t group) { 75 ext4_grpblk_t overhead; 76 overhead = ext4_bg_num_gdb(sb, group); 77 if (ext4_bg_has_super(sb, group)) 78 overhead += 1 + 79 le16_to_cpu(EXT4_SB(sb)->s_es->s_reserved_gdt_blocks); 80 return overhead; 81 } 82 83 #define outside(b, first, last) ((b) < (first) || (b) >= (last)) 84 #define inside(b, first, last) ((b) >= (first) && (b) < (last)) 85 86 static int verify_group_input(struct super_block *sb, 87 struct ext4_new_group_data *input) 88 { 89 struct ext4_sb_info *sbi = EXT4_SB(sb); 90 struct ext4_super_block *es = sbi->s_es; 91 ext4_fsblk_t start = ext4_blocks_count(es); 92 ext4_fsblk_t end = start + input->blocks_count; 93 ext4_group_t group = input->group; 94 ext4_fsblk_t itend = input->inode_table + sbi->s_itb_per_group; 95 unsigned overhead; 96 ext4_fsblk_t metaend; 97 struct buffer_head *bh = NULL; 98 ext4_grpblk_t free_blocks_count, offset; 99 int err = -EINVAL; 100 101 if (group != sbi->s_groups_count) { 102 ext4_warning(sb, "Cannot add at group %u (only %u groups)", 103 input->group, sbi->s_groups_count); 104 return -EINVAL; 105 } 106 107 overhead = ext4_group_overhead_blocks(sb, group); 108 metaend = start + overhead; 109 input->free_clusters_count = free_blocks_count = 110 input->blocks_count - 2 - overhead - sbi->s_itb_per_group; 111 112 if (test_opt(sb, DEBUG)) 113 printk(KERN_DEBUG "EXT4-fs: adding %s group %u: %u blocks " 114 "(%d free, %u reserved)\n", 115 ext4_bg_has_super(sb, input->group) ? "normal" : 116 "no-super", input->group, input->blocks_count, 117 free_blocks_count, input->reserved_blocks); 118 119 ext4_get_group_no_and_offset(sb, start, NULL, &offset); 120 if (offset != 0) 121 ext4_warning(sb, "Last group not full"); 122 else if (input->reserved_blocks > input->blocks_count / 5) 123 ext4_warning(sb, "Reserved blocks too high (%u)", 124 input->reserved_blocks); 125 else if (free_blocks_count < 0) 126 ext4_warning(sb, "Bad blocks count %u", 127 input->blocks_count); 128 else if (!(bh = sb_bread(sb, end - 1))) 129 ext4_warning(sb, "Cannot read last block (%llu)", 130 end - 1); 131 else if (outside(input->block_bitmap, start, end)) 132 ext4_warning(sb, "Block bitmap not in group (block %llu)", 133 (unsigned long long)input->block_bitmap); 134 else if (outside(input->inode_bitmap, start, end)) 135 ext4_warning(sb, "Inode bitmap not in group (block %llu)", 136 (unsigned long long)input->inode_bitmap); 137 else if (outside(input->inode_table, start, end) || 138 outside(itend - 1, start, end)) 139 ext4_warning(sb, "Inode table not in group (blocks %llu-%llu)", 140 (unsigned long long)input->inode_table, itend - 1); 141 else if (input->inode_bitmap == input->block_bitmap) 142 ext4_warning(sb, "Block bitmap same as inode bitmap (%llu)", 143 (unsigned long long)input->block_bitmap); 144 else if (inside(input->block_bitmap, input->inode_table, itend)) 145 ext4_warning(sb, "Block bitmap (%llu) in inode table " 146 "(%llu-%llu)", 147 (unsigned long long)input->block_bitmap, 148 (unsigned long long)input->inode_table, itend - 1); 149 else if (inside(input->inode_bitmap, input->inode_table, itend)) 150 ext4_warning(sb, "Inode bitmap (%llu) in inode table " 151 "(%llu-%llu)", 152 (unsigned long long)input->inode_bitmap, 153 (unsigned long long)input->inode_table, itend - 1); 154 else if (inside(input->block_bitmap, start, metaend)) 155 ext4_warning(sb, "Block bitmap (%llu) in GDT table (%llu-%llu)", 156 (unsigned long long)input->block_bitmap, 157 start, metaend - 1); 158 else if (inside(input->inode_bitmap, start, metaend)) 159 ext4_warning(sb, "Inode bitmap (%llu) in GDT table (%llu-%llu)", 160 (unsigned long long)input->inode_bitmap, 161 start, metaend - 1); 162 else if (inside(input->inode_table, start, metaend) || 163 inside(itend - 1, start, metaend)) 164 ext4_warning(sb, "Inode table (%llu-%llu) overlaps GDT table " 165 "(%llu-%llu)", 166 (unsigned long long)input->inode_table, 167 itend - 1, start, metaend - 1); 168 else 169 err = 0; 170 brelse(bh); 171 172 return err; 173 } 174 175 /* 176 * ext4_new_flex_group_data is used by 64bit-resize interface to add a flex 177 * group each time. 178 */ 179 struct ext4_new_flex_group_data { 180 struct ext4_new_group_data *groups; /* new_group_data for groups 181 in the flex group */ 182 __u16 *bg_flags; /* block group flags of groups 183 in @groups */ 184 ext4_group_t count; /* number of groups in @groups 185 */ 186 }; 187 188 /* 189 * alloc_flex_gd() allocates a ext4_new_flex_group_data with size of 190 * @flexbg_size. 191 * 192 * Returns NULL on failure otherwise address of the allocated structure. 193 */ 194 static struct ext4_new_flex_group_data *alloc_flex_gd(unsigned long flexbg_size) 195 { 196 struct ext4_new_flex_group_data *flex_gd; 197 198 flex_gd = kmalloc(sizeof(*flex_gd), GFP_NOFS); 199 if (flex_gd == NULL) 200 goto out3; 201 202 if (flexbg_size >= UINT_MAX / sizeof(struct ext4_new_group_data)) 203 goto out2; 204 flex_gd->count = flexbg_size; 205 206 flex_gd->groups = kmalloc(sizeof(struct ext4_new_group_data) * 207 flexbg_size, GFP_NOFS); 208 if (flex_gd->groups == NULL) 209 goto out2; 210 211 flex_gd->bg_flags = kmalloc(flexbg_size * sizeof(__u16), GFP_NOFS); 212 if (flex_gd->bg_flags == NULL) 213 goto out1; 214 215 return flex_gd; 216 217 out1: 218 kfree(flex_gd->groups); 219 out2: 220 kfree(flex_gd); 221 out3: 222 return NULL; 223 } 224 225 static void free_flex_gd(struct ext4_new_flex_group_data *flex_gd) 226 { 227 kfree(flex_gd->bg_flags); 228 kfree(flex_gd->groups); 229 kfree(flex_gd); 230 } 231 232 /* 233 * ext4_alloc_group_tables() allocates block bitmaps, inode bitmaps 234 * and inode tables for a flex group. 235 * 236 * This function is used by 64bit-resize. Note that this function allocates 237 * group tables from the 1st group of groups contained by @flexgd, which may 238 * be a partial of a flex group. 239 * 240 * @sb: super block of fs to which the groups belongs 241 * 242 * Returns 0 on a successful allocation of the metadata blocks in the 243 * block group. 244 */ 245 static int ext4_alloc_group_tables(struct super_block *sb, 246 struct ext4_new_flex_group_data *flex_gd, 247 int flexbg_size) 248 { 249 struct ext4_new_group_data *group_data = flex_gd->groups; 250 ext4_fsblk_t start_blk; 251 ext4_fsblk_t last_blk; 252 ext4_group_t src_group; 253 ext4_group_t bb_index = 0; 254 ext4_group_t ib_index = 0; 255 ext4_group_t it_index = 0; 256 ext4_group_t group; 257 ext4_group_t last_group; 258 unsigned overhead; 259 __u16 uninit_mask = (flexbg_size > 1) ? ~EXT4_BG_BLOCK_UNINIT : ~0; 260 int i; 261 262 BUG_ON(flex_gd->count == 0 || group_data == NULL); 263 264 src_group = group_data[0].group; 265 last_group = src_group + flex_gd->count - 1; 266 267 BUG_ON((flexbg_size > 1) && ((src_group & ~(flexbg_size - 1)) != 268 (last_group & ~(flexbg_size - 1)))); 269 next_group: 270 group = group_data[0].group; 271 if (src_group >= group_data[0].group + flex_gd->count) 272 return -ENOSPC; 273 start_blk = ext4_group_first_block_no(sb, src_group); 274 last_blk = start_blk + group_data[src_group - group].blocks_count; 275 276 overhead = ext4_group_overhead_blocks(sb, src_group); 277 278 start_blk += overhead; 279 280 /* We collect contiguous blocks as much as possible. */ 281 src_group++; 282 for (; src_group <= last_group; src_group++) { 283 overhead = ext4_group_overhead_blocks(sb, src_group); 284 if (overhead == 0) 285 last_blk += group_data[src_group - group].blocks_count; 286 else 287 break; 288 } 289 290 /* Allocate block bitmaps */ 291 for (; bb_index < flex_gd->count; bb_index++) { 292 if (start_blk >= last_blk) 293 goto next_group; 294 group_data[bb_index].block_bitmap = start_blk++; 295 group = ext4_get_group_number(sb, start_blk - 1); 296 group -= group_data[0].group; 297 group_data[group].mdata_blocks++; 298 flex_gd->bg_flags[group] &= uninit_mask; 299 } 300 301 /* Allocate inode bitmaps */ 302 for (; ib_index < flex_gd->count; ib_index++) { 303 if (start_blk >= last_blk) 304 goto next_group; 305 group_data[ib_index].inode_bitmap = start_blk++; 306 group = ext4_get_group_number(sb, start_blk - 1); 307 group -= group_data[0].group; 308 group_data[group].mdata_blocks++; 309 flex_gd->bg_flags[group] &= uninit_mask; 310 } 311 312 /* Allocate inode tables */ 313 for (; it_index < flex_gd->count; it_index++) { 314 unsigned int itb = EXT4_SB(sb)->s_itb_per_group; 315 ext4_fsblk_t next_group_start; 316 317 if (start_blk + itb > last_blk) 318 goto next_group; 319 group_data[it_index].inode_table = start_blk; 320 group = ext4_get_group_number(sb, start_blk); 321 next_group_start = ext4_group_first_block_no(sb, group + 1); 322 group -= group_data[0].group; 323 324 if (start_blk + itb > next_group_start) { 325 flex_gd->bg_flags[group + 1] &= uninit_mask; 326 overhead = start_blk + itb - next_group_start; 327 group_data[group + 1].mdata_blocks += overhead; 328 itb -= overhead; 329 } 330 331 group_data[group].mdata_blocks += itb; 332 flex_gd->bg_flags[group] &= uninit_mask; 333 start_blk += EXT4_SB(sb)->s_itb_per_group; 334 } 335 336 /* Update free clusters count to exclude metadata blocks */ 337 for (i = 0; i < flex_gd->count; i++) { 338 group_data[i].free_clusters_count -= 339 EXT4_NUM_B2C(EXT4_SB(sb), 340 group_data[i].mdata_blocks); 341 } 342 343 if (test_opt(sb, DEBUG)) { 344 int i; 345 group = group_data[0].group; 346 347 printk(KERN_DEBUG "EXT4-fs: adding a flex group with " 348 "%d groups, flexbg size is %d:\n", flex_gd->count, 349 flexbg_size); 350 351 for (i = 0; i < flex_gd->count; i++) { 352 ext4_debug( 353 "adding %s group %u: %u blocks (%d free, %d mdata blocks)\n", 354 ext4_bg_has_super(sb, group + i) ? "normal" : 355 "no-super", group + i, 356 group_data[i].blocks_count, 357 group_data[i].free_clusters_count, 358 group_data[i].mdata_blocks); 359 } 360 } 361 return 0; 362 } 363 364 static struct buffer_head *bclean(handle_t *handle, struct super_block *sb, 365 ext4_fsblk_t blk) 366 { 367 struct buffer_head *bh; 368 int err; 369 370 bh = sb_getblk(sb, blk); 371 if (unlikely(!bh)) 372 return ERR_PTR(-ENOMEM); 373 BUFFER_TRACE(bh, "get_write_access"); 374 if ((err = ext4_journal_get_write_access(handle, bh))) { 375 brelse(bh); 376 bh = ERR_PTR(err); 377 } else { 378 memset(bh->b_data, 0, sb->s_blocksize); 379 set_buffer_uptodate(bh); 380 } 381 382 return bh; 383 } 384 385 /* 386 * If we have fewer than thresh credits, extend by EXT4_MAX_TRANS_DATA. 387 * If that fails, restart the transaction & regain write access for the 388 * buffer head which is used for block_bitmap modifications. 389 */ 390 static int extend_or_restart_transaction(handle_t *handle, int thresh) 391 { 392 int err; 393 394 if (ext4_handle_has_enough_credits(handle, thresh)) 395 return 0; 396 397 err = ext4_journal_extend(handle, EXT4_MAX_TRANS_DATA); 398 if (err < 0) 399 return err; 400 if (err) { 401 err = ext4_journal_restart(handle, EXT4_MAX_TRANS_DATA); 402 if (err) 403 return err; 404 } 405 406 return 0; 407 } 408 409 /* 410 * set_flexbg_block_bitmap() mark clusters [@first_cluster, @last_cluster] used. 411 * 412 * Helper function for ext4_setup_new_group_blocks() which set . 413 * 414 * @sb: super block 415 * @handle: journal handle 416 * @flex_gd: flex group data 417 */ 418 static int set_flexbg_block_bitmap(struct super_block *sb, handle_t *handle, 419 struct ext4_new_flex_group_data *flex_gd, 420 ext4_fsblk_t first_cluster, ext4_fsblk_t last_cluster) 421 { 422 struct ext4_sb_info *sbi = EXT4_SB(sb); 423 ext4_group_t count = last_cluster - first_cluster + 1; 424 ext4_group_t count2; 425 426 ext4_debug("mark clusters [%llu-%llu] used\n", first_cluster, 427 last_cluster); 428 for (count2 = count; count > 0; 429 count -= count2, first_cluster += count2) { 430 ext4_fsblk_t start; 431 struct buffer_head *bh; 432 ext4_group_t group; 433 int err; 434 435 group = ext4_get_group_number(sb, EXT4_C2B(sbi, first_cluster)); 436 start = EXT4_B2C(sbi, ext4_group_first_block_no(sb, group)); 437 group -= flex_gd->groups[0].group; 438 439 count2 = EXT4_CLUSTERS_PER_GROUP(sb) - (first_cluster - start); 440 if (count2 > count) 441 count2 = count; 442 443 if (flex_gd->bg_flags[group] & EXT4_BG_BLOCK_UNINIT) { 444 BUG_ON(flex_gd->count > 1); 445 continue; 446 } 447 448 err = extend_or_restart_transaction(handle, 1); 449 if (err) 450 return err; 451 452 bh = sb_getblk(sb, flex_gd->groups[group].block_bitmap); 453 if (unlikely(!bh)) 454 return -ENOMEM; 455 456 BUFFER_TRACE(bh, "get_write_access"); 457 err = ext4_journal_get_write_access(handle, bh); 458 if (err) 459 return err; 460 ext4_debug("mark block bitmap %#04llx (+%llu/%u)\n", 461 first_cluster, first_cluster - start, count2); 462 ext4_set_bits(bh->b_data, first_cluster - start, count2); 463 464 err = ext4_handle_dirty_metadata(handle, NULL, bh); 465 if (unlikely(err)) 466 return err; 467 brelse(bh); 468 } 469 470 return 0; 471 } 472 473 /* 474 * Set up the block and inode bitmaps, and the inode table for the new groups. 475 * This doesn't need to be part of the main transaction, since we are only 476 * changing blocks outside the actual filesystem. We still do journaling to 477 * ensure the recovery is correct in case of a failure just after resize. 478 * If any part of this fails, we simply abort the resize. 479 * 480 * setup_new_flex_group_blocks handles a flex group as follow: 481 * 1. copy super block and GDT, and initialize group tables if necessary. 482 * In this step, we only set bits in blocks bitmaps for blocks taken by 483 * super block and GDT. 484 * 2. allocate group tables in block bitmaps, that is, set bits in block 485 * bitmap for blocks taken by group tables. 486 */ 487 static int setup_new_flex_group_blocks(struct super_block *sb, 488 struct ext4_new_flex_group_data *flex_gd) 489 { 490 int group_table_count[] = {1, 1, EXT4_SB(sb)->s_itb_per_group}; 491 ext4_fsblk_t start; 492 ext4_fsblk_t block; 493 struct ext4_sb_info *sbi = EXT4_SB(sb); 494 struct ext4_super_block *es = sbi->s_es; 495 struct ext4_new_group_data *group_data = flex_gd->groups; 496 __u16 *bg_flags = flex_gd->bg_flags; 497 handle_t *handle; 498 ext4_group_t group, count; 499 struct buffer_head *bh = NULL; 500 int reserved_gdb, i, j, err = 0, err2; 501 int meta_bg; 502 503 BUG_ON(!flex_gd->count || !group_data || 504 group_data[0].group != sbi->s_groups_count); 505 506 reserved_gdb = le16_to_cpu(es->s_reserved_gdt_blocks); 507 meta_bg = ext4_has_feature_meta_bg(sb); 508 509 /* This transaction may be extended/restarted along the way */ 510 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, EXT4_MAX_TRANS_DATA); 511 if (IS_ERR(handle)) 512 return PTR_ERR(handle); 513 514 group = group_data[0].group; 515 for (i = 0; i < flex_gd->count; i++, group++) { 516 unsigned long gdblocks; 517 ext4_grpblk_t overhead; 518 519 gdblocks = ext4_bg_num_gdb(sb, group); 520 start = ext4_group_first_block_no(sb, group); 521 522 if (meta_bg == 0 && !ext4_bg_has_super(sb, group)) 523 goto handle_itb; 524 525 if (meta_bg == 1) { 526 ext4_group_t first_group; 527 first_group = ext4_meta_bg_first_group(sb, group); 528 if (first_group != group + 1 && 529 first_group != group + EXT4_DESC_PER_BLOCK(sb) - 1) 530 goto handle_itb; 531 } 532 533 block = start + ext4_bg_has_super(sb, group); 534 /* Copy all of the GDT blocks into the backup in this group */ 535 for (j = 0; j < gdblocks; j++, block++) { 536 struct buffer_head *gdb; 537 538 ext4_debug("update backup group %#04llx\n", block); 539 err = extend_or_restart_transaction(handle, 1); 540 if (err) 541 goto out; 542 543 gdb = sb_getblk(sb, block); 544 if (unlikely(!gdb)) { 545 err = -ENOMEM; 546 goto out; 547 } 548 549 BUFFER_TRACE(gdb, "get_write_access"); 550 err = ext4_journal_get_write_access(handle, gdb); 551 if (err) { 552 brelse(gdb); 553 goto out; 554 } 555 memcpy(gdb->b_data, sbi->s_group_desc[j]->b_data, 556 gdb->b_size); 557 set_buffer_uptodate(gdb); 558 559 err = ext4_handle_dirty_metadata(handle, NULL, gdb); 560 if (unlikely(err)) { 561 brelse(gdb); 562 goto out; 563 } 564 brelse(gdb); 565 } 566 567 /* Zero out all of the reserved backup group descriptor 568 * table blocks 569 */ 570 if (ext4_bg_has_super(sb, group)) { 571 err = sb_issue_zeroout(sb, gdblocks + start + 1, 572 reserved_gdb, GFP_NOFS); 573 if (err) 574 goto out; 575 } 576 577 handle_itb: 578 /* Initialize group tables of the grop @group */ 579 if (!(bg_flags[i] & EXT4_BG_INODE_ZEROED)) 580 goto handle_bb; 581 582 /* Zero out all of the inode table blocks */ 583 block = group_data[i].inode_table; 584 ext4_debug("clear inode table blocks %#04llx -> %#04lx\n", 585 block, sbi->s_itb_per_group); 586 err = sb_issue_zeroout(sb, block, sbi->s_itb_per_group, 587 GFP_NOFS); 588 if (err) 589 goto out; 590 591 handle_bb: 592 if (bg_flags[i] & EXT4_BG_BLOCK_UNINIT) 593 goto handle_ib; 594 595 /* Initialize block bitmap of the @group */ 596 block = group_data[i].block_bitmap; 597 err = extend_or_restart_transaction(handle, 1); 598 if (err) 599 goto out; 600 601 bh = bclean(handle, sb, block); 602 if (IS_ERR(bh)) { 603 err = PTR_ERR(bh); 604 bh = NULL; 605 goto out; 606 } 607 overhead = ext4_group_overhead_blocks(sb, group); 608 if (overhead != 0) { 609 ext4_debug("mark backup superblock %#04llx (+0)\n", 610 start); 611 ext4_set_bits(bh->b_data, 0, 612 EXT4_NUM_B2C(sbi, overhead)); 613 } 614 ext4_mark_bitmap_end(EXT4_B2C(sbi, group_data[i].blocks_count), 615 sb->s_blocksize * 8, bh->b_data); 616 err = ext4_handle_dirty_metadata(handle, NULL, bh); 617 if (err) 618 goto out; 619 brelse(bh); 620 621 handle_ib: 622 if (bg_flags[i] & EXT4_BG_INODE_UNINIT) 623 continue; 624 625 /* Initialize inode bitmap of the @group */ 626 block = group_data[i].inode_bitmap; 627 err = extend_or_restart_transaction(handle, 1); 628 if (err) 629 goto out; 630 /* Mark unused entries in inode bitmap used */ 631 bh = bclean(handle, sb, block); 632 if (IS_ERR(bh)) { 633 err = PTR_ERR(bh); 634 bh = NULL; 635 goto out; 636 } 637 638 ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb), 639 sb->s_blocksize * 8, bh->b_data); 640 err = ext4_handle_dirty_metadata(handle, NULL, bh); 641 if (err) 642 goto out; 643 brelse(bh); 644 } 645 bh = NULL; 646 647 /* Mark group tables in block bitmap */ 648 for (j = 0; j < GROUP_TABLE_COUNT; j++) { 649 count = group_table_count[j]; 650 start = (&group_data[0].block_bitmap)[j]; 651 block = start; 652 for (i = 1; i < flex_gd->count; i++) { 653 block += group_table_count[j]; 654 if (block == (&group_data[i].block_bitmap)[j]) { 655 count += group_table_count[j]; 656 continue; 657 } 658 err = set_flexbg_block_bitmap(sb, handle, 659 flex_gd, 660 EXT4_B2C(sbi, start), 661 EXT4_B2C(sbi, 662 start + count 663 - 1)); 664 if (err) 665 goto out; 666 count = group_table_count[j]; 667 start = (&group_data[i].block_bitmap)[j]; 668 block = start; 669 } 670 671 if (count) { 672 err = set_flexbg_block_bitmap(sb, handle, 673 flex_gd, 674 EXT4_B2C(sbi, start), 675 EXT4_B2C(sbi, 676 start + count 677 - 1)); 678 if (err) 679 goto out; 680 } 681 } 682 683 out: 684 brelse(bh); 685 err2 = ext4_journal_stop(handle); 686 if (err2 && !err) 687 err = err2; 688 689 return err; 690 } 691 692 /* 693 * Iterate through the groups which hold BACKUP superblock/GDT copies in an 694 * ext4 filesystem. The counters should be initialized to 1, 5, and 7 before 695 * calling this for the first time. In a sparse filesystem it will be the 696 * sequence of powers of 3, 5, and 7: 1, 3, 5, 7, 9, 25, 27, 49, 81, ... 697 * For a non-sparse filesystem it will be every group: 1, 2, 3, 4, ... 698 */ 699 static unsigned ext4_list_backups(struct super_block *sb, unsigned *three, 700 unsigned *five, unsigned *seven) 701 { 702 unsigned *min = three; 703 int mult = 3; 704 unsigned ret; 705 706 if (!ext4_has_feature_sparse_super(sb)) { 707 ret = *min; 708 *min += 1; 709 return ret; 710 } 711 712 if (*five < *min) { 713 min = five; 714 mult = 5; 715 } 716 if (*seven < *min) { 717 min = seven; 718 mult = 7; 719 } 720 721 ret = *min; 722 *min *= mult; 723 724 return ret; 725 } 726 727 /* 728 * Check that all of the backup GDT blocks are held in the primary GDT block. 729 * It is assumed that they are stored in group order. Returns the number of 730 * groups in current filesystem that have BACKUPS, or -ve error code. 731 */ 732 static int verify_reserved_gdb(struct super_block *sb, 733 ext4_group_t end, 734 struct buffer_head *primary) 735 { 736 const ext4_fsblk_t blk = primary->b_blocknr; 737 unsigned three = 1; 738 unsigned five = 5; 739 unsigned seven = 7; 740 unsigned grp; 741 __le32 *p = (__le32 *)primary->b_data; 742 int gdbackups = 0; 743 744 while ((grp = ext4_list_backups(sb, &three, &five, &seven)) < end) { 745 if (le32_to_cpu(*p++) != 746 grp * EXT4_BLOCKS_PER_GROUP(sb) + blk){ 747 ext4_warning(sb, "reserved GDT %llu" 748 " missing grp %d (%llu)", 749 blk, grp, 750 grp * 751 (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) + 752 blk); 753 return -EINVAL; 754 } 755 if (++gdbackups > EXT4_ADDR_PER_BLOCK(sb)) 756 return -EFBIG; 757 } 758 759 return gdbackups; 760 } 761 762 /* 763 * Called when we need to bring a reserved group descriptor table block into 764 * use from the resize inode. The primary copy of the new GDT block currently 765 * is an indirect block (under the double indirect block in the resize inode). 766 * The new backup GDT blocks will be stored as leaf blocks in this indirect 767 * block, in group order. Even though we know all the block numbers we need, 768 * we check to ensure that the resize inode has actually reserved these blocks. 769 * 770 * Don't need to update the block bitmaps because the blocks are still in use. 771 * 772 * We get all of the error cases out of the way, so that we are sure to not 773 * fail once we start modifying the data on disk, because JBD has no rollback. 774 */ 775 static int add_new_gdb(handle_t *handle, struct inode *inode, 776 ext4_group_t group) 777 { 778 struct super_block *sb = inode->i_sb; 779 struct ext4_super_block *es = EXT4_SB(sb)->s_es; 780 unsigned long gdb_num = group / EXT4_DESC_PER_BLOCK(sb); 781 ext4_fsblk_t gdblock = EXT4_SB(sb)->s_sbh->b_blocknr + 1 + gdb_num; 782 struct buffer_head **o_group_desc, **n_group_desc; 783 struct buffer_head *dind; 784 struct buffer_head *gdb_bh; 785 int gdbackups; 786 struct ext4_iloc iloc; 787 __le32 *data; 788 int err; 789 790 if (test_opt(sb, DEBUG)) 791 printk(KERN_DEBUG 792 "EXT4-fs: ext4_add_new_gdb: adding group block %lu\n", 793 gdb_num); 794 795 gdb_bh = sb_bread(sb, gdblock); 796 if (!gdb_bh) 797 return -EIO; 798 799 gdbackups = verify_reserved_gdb(sb, group, gdb_bh); 800 if (gdbackups < 0) { 801 err = gdbackups; 802 goto exit_bh; 803 } 804 805 data = EXT4_I(inode)->i_data + EXT4_DIND_BLOCK; 806 dind = sb_bread(sb, le32_to_cpu(*data)); 807 if (!dind) { 808 err = -EIO; 809 goto exit_bh; 810 } 811 812 data = (__le32 *)dind->b_data; 813 if (le32_to_cpu(data[gdb_num % EXT4_ADDR_PER_BLOCK(sb)]) != gdblock) { 814 ext4_warning(sb, "new group %u GDT block %llu not reserved", 815 group, gdblock); 816 err = -EINVAL; 817 goto exit_dind; 818 } 819 820 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access"); 821 err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh); 822 if (unlikely(err)) 823 goto exit_dind; 824 825 BUFFER_TRACE(gdb_bh, "get_write_access"); 826 err = ext4_journal_get_write_access(handle, gdb_bh); 827 if (unlikely(err)) 828 goto exit_dind; 829 830 BUFFER_TRACE(dind, "get_write_access"); 831 err = ext4_journal_get_write_access(handle, dind); 832 if (unlikely(err)) 833 ext4_std_error(sb, err); 834 835 /* ext4_reserve_inode_write() gets a reference on the iloc */ 836 err = ext4_reserve_inode_write(handle, inode, &iloc); 837 if (unlikely(err)) 838 goto exit_dind; 839 840 n_group_desc = ext4_kvmalloc((gdb_num + 1) * 841 sizeof(struct buffer_head *), 842 GFP_NOFS); 843 if (!n_group_desc) { 844 err = -ENOMEM; 845 ext4_warning(sb, "not enough memory for %lu groups", 846 gdb_num + 1); 847 goto exit_inode; 848 } 849 850 /* 851 * Finally, we have all of the possible failures behind us... 852 * 853 * Remove new GDT block from inode double-indirect block and clear out 854 * the new GDT block for use (which also "frees" the backup GDT blocks 855 * from the reserved inode). We don't need to change the bitmaps for 856 * these blocks, because they are marked as in-use from being in the 857 * reserved inode, and will become GDT blocks (primary and backup). 858 */ 859 data[gdb_num % EXT4_ADDR_PER_BLOCK(sb)] = 0; 860 err = ext4_handle_dirty_metadata(handle, NULL, dind); 861 if (unlikely(err)) { 862 ext4_std_error(sb, err); 863 goto exit_inode; 864 } 865 inode->i_blocks -= (gdbackups + 1) * sb->s_blocksize >> 866 (9 - EXT4_SB(sb)->s_cluster_bits); 867 ext4_mark_iloc_dirty(handle, inode, &iloc); 868 memset(gdb_bh->b_data, 0, sb->s_blocksize); 869 err = ext4_handle_dirty_metadata(handle, NULL, gdb_bh); 870 if (unlikely(err)) { 871 ext4_std_error(sb, err); 872 goto exit_inode; 873 } 874 brelse(dind); 875 876 o_group_desc = EXT4_SB(sb)->s_group_desc; 877 memcpy(n_group_desc, o_group_desc, 878 EXT4_SB(sb)->s_gdb_count * sizeof(struct buffer_head *)); 879 n_group_desc[gdb_num] = gdb_bh; 880 EXT4_SB(sb)->s_group_desc = n_group_desc; 881 EXT4_SB(sb)->s_gdb_count++; 882 kvfree(o_group_desc); 883 884 le16_add_cpu(&es->s_reserved_gdt_blocks, -1); 885 err = ext4_handle_dirty_super(handle, sb); 886 if (err) 887 ext4_std_error(sb, err); 888 889 return err; 890 891 exit_inode: 892 kvfree(n_group_desc); 893 brelse(iloc.bh); 894 exit_dind: 895 brelse(dind); 896 exit_bh: 897 brelse(gdb_bh); 898 899 ext4_debug("leaving with error %d\n", err); 900 return err; 901 } 902 903 /* 904 * add_new_gdb_meta_bg is the sister of add_new_gdb. 905 */ 906 static int add_new_gdb_meta_bg(struct super_block *sb, 907 handle_t *handle, ext4_group_t group) { 908 ext4_fsblk_t gdblock; 909 struct buffer_head *gdb_bh; 910 struct buffer_head **o_group_desc, **n_group_desc; 911 unsigned long gdb_num = group / EXT4_DESC_PER_BLOCK(sb); 912 int err; 913 914 gdblock = ext4_meta_bg_first_block_no(sb, group) + 915 ext4_bg_has_super(sb, group); 916 gdb_bh = sb_bread(sb, gdblock); 917 if (!gdb_bh) 918 return -EIO; 919 n_group_desc = ext4_kvmalloc((gdb_num + 1) * 920 sizeof(struct buffer_head *), 921 GFP_NOFS); 922 if (!n_group_desc) { 923 err = -ENOMEM; 924 ext4_warning(sb, "not enough memory for %lu groups", 925 gdb_num + 1); 926 return err; 927 } 928 929 o_group_desc = EXT4_SB(sb)->s_group_desc; 930 memcpy(n_group_desc, o_group_desc, 931 EXT4_SB(sb)->s_gdb_count * sizeof(struct buffer_head *)); 932 n_group_desc[gdb_num] = gdb_bh; 933 EXT4_SB(sb)->s_group_desc = n_group_desc; 934 EXT4_SB(sb)->s_gdb_count++; 935 kvfree(o_group_desc); 936 BUFFER_TRACE(gdb_bh, "get_write_access"); 937 err = ext4_journal_get_write_access(handle, gdb_bh); 938 if (unlikely(err)) 939 brelse(gdb_bh); 940 return err; 941 } 942 943 /* 944 * Called when we are adding a new group which has a backup copy of each of 945 * the GDT blocks (i.e. sparse group) and there are reserved GDT blocks. 946 * We need to add these reserved backup GDT blocks to the resize inode, so 947 * that they are kept for future resizing and not allocated to files. 948 * 949 * Each reserved backup GDT block will go into a different indirect block. 950 * The indirect blocks are actually the primary reserved GDT blocks, 951 * so we know in advance what their block numbers are. We only get the 952 * double-indirect block to verify it is pointing to the primary reserved 953 * GDT blocks so we don't overwrite a data block by accident. The reserved 954 * backup GDT blocks are stored in their reserved primary GDT block. 955 */ 956 static int reserve_backup_gdb(handle_t *handle, struct inode *inode, 957 ext4_group_t group) 958 { 959 struct super_block *sb = inode->i_sb; 960 int reserved_gdb =le16_to_cpu(EXT4_SB(sb)->s_es->s_reserved_gdt_blocks); 961 int cluster_bits = EXT4_SB(sb)->s_cluster_bits; 962 struct buffer_head **primary; 963 struct buffer_head *dind; 964 struct ext4_iloc iloc; 965 ext4_fsblk_t blk; 966 __le32 *data, *end; 967 int gdbackups = 0; 968 int res, i; 969 int err; 970 971 primary = kmalloc(reserved_gdb * sizeof(*primary), GFP_NOFS); 972 if (!primary) 973 return -ENOMEM; 974 975 data = EXT4_I(inode)->i_data + EXT4_DIND_BLOCK; 976 dind = sb_bread(sb, le32_to_cpu(*data)); 977 if (!dind) { 978 err = -EIO; 979 goto exit_free; 980 } 981 982 blk = EXT4_SB(sb)->s_sbh->b_blocknr + 1 + EXT4_SB(sb)->s_gdb_count; 983 data = (__le32 *)dind->b_data + (EXT4_SB(sb)->s_gdb_count % 984 EXT4_ADDR_PER_BLOCK(sb)); 985 end = (__le32 *)dind->b_data + EXT4_ADDR_PER_BLOCK(sb); 986 987 /* Get each reserved primary GDT block and verify it holds backups */ 988 for (res = 0; res < reserved_gdb; res++, blk++) { 989 if (le32_to_cpu(*data) != blk) { 990 ext4_warning(sb, "reserved block %llu" 991 " not at offset %ld", 992 blk, 993 (long)(data - (__le32 *)dind->b_data)); 994 err = -EINVAL; 995 goto exit_bh; 996 } 997 primary[res] = sb_bread(sb, blk); 998 if (!primary[res]) { 999 err = -EIO; 1000 goto exit_bh; 1001 } 1002 gdbackups = verify_reserved_gdb(sb, group, primary[res]); 1003 if (gdbackups < 0) { 1004 brelse(primary[res]); 1005 err = gdbackups; 1006 goto exit_bh; 1007 } 1008 if (++data >= end) 1009 data = (__le32 *)dind->b_data; 1010 } 1011 1012 for (i = 0; i < reserved_gdb; i++) { 1013 BUFFER_TRACE(primary[i], "get_write_access"); 1014 if ((err = ext4_journal_get_write_access(handle, primary[i]))) 1015 goto exit_bh; 1016 } 1017 1018 if ((err = ext4_reserve_inode_write(handle, inode, &iloc))) 1019 goto exit_bh; 1020 1021 /* 1022 * Finally we can add each of the reserved backup GDT blocks from 1023 * the new group to its reserved primary GDT block. 1024 */ 1025 blk = group * EXT4_BLOCKS_PER_GROUP(sb); 1026 for (i = 0; i < reserved_gdb; i++) { 1027 int err2; 1028 data = (__le32 *)primary[i]->b_data; 1029 /* printk("reserving backup %lu[%u] = %lu\n", 1030 primary[i]->b_blocknr, gdbackups, 1031 blk + primary[i]->b_blocknr); */ 1032 data[gdbackups] = cpu_to_le32(blk + primary[i]->b_blocknr); 1033 err2 = ext4_handle_dirty_metadata(handle, NULL, primary[i]); 1034 if (!err) 1035 err = err2; 1036 } 1037 1038 inode->i_blocks += reserved_gdb * sb->s_blocksize >> (9 - cluster_bits); 1039 ext4_mark_iloc_dirty(handle, inode, &iloc); 1040 1041 exit_bh: 1042 while (--res >= 0) 1043 brelse(primary[res]); 1044 brelse(dind); 1045 1046 exit_free: 1047 kfree(primary); 1048 1049 return err; 1050 } 1051 1052 /* 1053 * Update the backup copies of the ext4 metadata. These don't need to be part 1054 * of the main resize transaction, because e2fsck will re-write them if there 1055 * is a problem (basically only OOM will cause a problem). However, we 1056 * _should_ update the backups if possible, in case the primary gets trashed 1057 * for some reason and we need to run e2fsck from a backup superblock. The 1058 * important part is that the new block and inode counts are in the backup 1059 * superblocks, and the location of the new group metadata in the GDT backups. 1060 * 1061 * We do not need take the s_resize_lock for this, because these 1062 * blocks are not otherwise touched by the filesystem code when it is 1063 * mounted. We don't need to worry about last changing from 1064 * sbi->s_groups_count, because the worst that can happen is that we 1065 * do not copy the full number of backups at this time. The resize 1066 * which changed s_groups_count will backup again. 1067 */ 1068 static void update_backups(struct super_block *sb, sector_t blk_off, char *data, 1069 int size, int meta_bg) 1070 { 1071 struct ext4_sb_info *sbi = EXT4_SB(sb); 1072 ext4_group_t last; 1073 const int bpg = EXT4_BLOCKS_PER_GROUP(sb); 1074 unsigned three = 1; 1075 unsigned five = 5; 1076 unsigned seven = 7; 1077 ext4_group_t group = 0; 1078 int rest = sb->s_blocksize - size; 1079 handle_t *handle; 1080 int err = 0, err2; 1081 1082 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, EXT4_MAX_TRANS_DATA); 1083 if (IS_ERR(handle)) { 1084 group = 1; 1085 err = PTR_ERR(handle); 1086 goto exit_err; 1087 } 1088 1089 if (meta_bg == 0) { 1090 group = ext4_list_backups(sb, &three, &five, &seven); 1091 last = sbi->s_groups_count; 1092 } else { 1093 group = ext4_get_group_number(sb, blk_off) + 1; 1094 last = (ext4_group_t)(group + EXT4_DESC_PER_BLOCK(sb) - 2); 1095 } 1096 1097 while (group < sbi->s_groups_count) { 1098 struct buffer_head *bh; 1099 ext4_fsblk_t backup_block; 1100 1101 /* Out of journal space, and can't get more - abort - so sad */ 1102 if (ext4_handle_valid(handle) && 1103 handle->h_buffer_credits == 0 && 1104 ext4_journal_extend(handle, EXT4_MAX_TRANS_DATA) && 1105 (err = ext4_journal_restart(handle, EXT4_MAX_TRANS_DATA))) 1106 break; 1107 1108 if (meta_bg == 0) 1109 backup_block = ((ext4_fsblk_t)group) * bpg + blk_off; 1110 else 1111 backup_block = (ext4_group_first_block_no(sb, group) + 1112 ext4_bg_has_super(sb, group)); 1113 1114 bh = sb_getblk(sb, backup_block); 1115 if (unlikely(!bh)) { 1116 err = -ENOMEM; 1117 break; 1118 } 1119 ext4_debug("update metadata backup %llu(+%llu)\n", 1120 backup_block, backup_block - 1121 ext4_group_first_block_no(sb, group)); 1122 BUFFER_TRACE(bh, "get_write_access"); 1123 if ((err = ext4_journal_get_write_access(handle, bh))) 1124 break; 1125 lock_buffer(bh); 1126 memcpy(bh->b_data, data, size); 1127 if (rest) 1128 memset(bh->b_data + size, 0, rest); 1129 set_buffer_uptodate(bh); 1130 unlock_buffer(bh); 1131 err = ext4_handle_dirty_metadata(handle, NULL, bh); 1132 if (unlikely(err)) 1133 ext4_std_error(sb, err); 1134 brelse(bh); 1135 1136 if (meta_bg == 0) 1137 group = ext4_list_backups(sb, &three, &five, &seven); 1138 else if (group == last) 1139 break; 1140 else 1141 group = last; 1142 } 1143 if ((err2 = ext4_journal_stop(handle)) && !err) 1144 err = err2; 1145 1146 /* 1147 * Ugh! Need to have e2fsck write the backup copies. It is too 1148 * late to revert the resize, we shouldn't fail just because of 1149 * the backup copies (they are only needed in case of corruption). 1150 * 1151 * However, if we got here we have a journal problem too, so we 1152 * can't really start a transaction to mark the superblock. 1153 * Chicken out and just set the flag on the hope it will be written 1154 * to disk, and if not - we will simply wait until next fsck. 1155 */ 1156 exit_err: 1157 if (err) { 1158 ext4_warning(sb, "can't update backup for group %u (err %d), " 1159 "forcing fsck on next reboot", group, err); 1160 sbi->s_mount_state &= ~EXT4_VALID_FS; 1161 sbi->s_es->s_state &= cpu_to_le16(~EXT4_VALID_FS); 1162 mark_buffer_dirty(sbi->s_sbh); 1163 } 1164 } 1165 1166 /* 1167 * ext4_add_new_descs() adds @count group descriptor of groups 1168 * starting at @group 1169 * 1170 * @handle: journal handle 1171 * @sb: super block 1172 * @group: the group no. of the first group desc to be added 1173 * @resize_inode: the resize inode 1174 * @count: number of group descriptors to be added 1175 */ 1176 static int ext4_add_new_descs(handle_t *handle, struct super_block *sb, 1177 ext4_group_t group, struct inode *resize_inode, 1178 ext4_group_t count) 1179 { 1180 struct ext4_sb_info *sbi = EXT4_SB(sb); 1181 struct ext4_super_block *es = sbi->s_es; 1182 struct buffer_head *gdb_bh; 1183 int i, gdb_off, gdb_num, err = 0; 1184 int meta_bg; 1185 1186 meta_bg = ext4_has_feature_meta_bg(sb); 1187 for (i = 0; i < count; i++, group++) { 1188 int reserved_gdb = ext4_bg_has_super(sb, group) ? 1189 le16_to_cpu(es->s_reserved_gdt_blocks) : 0; 1190 1191 gdb_off = group % EXT4_DESC_PER_BLOCK(sb); 1192 gdb_num = group / EXT4_DESC_PER_BLOCK(sb); 1193 1194 /* 1195 * We will only either add reserved group blocks to a backup group 1196 * or remove reserved blocks for the first group in a new group block. 1197 * Doing both would be mean more complex code, and sane people don't 1198 * use non-sparse filesystems anymore. This is already checked above. 1199 */ 1200 if (gdb_off) { 1201 gdb_bh = sbi->s_group_desc[gdb_num]; 1202 BUFFER_TRACE(gdb_bh, "get_write_access"); 1203 err = ext4_journal_get_write_access(handle, gdb_bh); 1204 1205 if (!err && reserved_gdb && ext4_bg_num_gdb(sb, group)) 1206 err = reserve_backup_gdb(handle, resize_inode, group); 1207 } else if (meta_bg != 0) { 1208 err = add_new_gdb_meta_bg(sb, handle, group); 1209 } else { 1210 err = add_new_gdb(handle, resize_inode, group); 1211 } 1212 if (err) 1213 break; 1214 } 1215 return err; 1216 } 1217 1218 static struct buffer_head *ext4_get_bitmap(struct super_block *sb, __u64 block) 1219 { 1220 struct buffer_head *bh = sb_getblk(sb, block); 1221 if (unlikely(!bh)) 1222 return NULL; 1223 if (!bh_uptodate_or_lock(bh)) { 1224 if (bh_submit_read(bh) < 0) { 1225 brelse(bh); 1226 return NULL; 1227 } 1228 } 1229 1230 return bh; 1231 } 1232 1233 static int ext4_set_bitmap_checksums(struct super_block *sb, 1234 ext4_group_t group, 1235 struct ext4_group_desc *gdp, 1236 struct ext4_new_group_data *group_data) 1237 { 1238 struct buffer_head *bh; 1239 1240 if (!ext4_has_metadata_csum(sb)) 1241 return 0; 1242 1243 bh = ext4_get_bitmap(sb, group_data->inode_bitmap); 1244 if (!bh) 1245 return -EIO; 1246 ext4_inode_bitmap_csum_set(sb, group, gdp, bh, 1247 EXT4_INODES_PER_GROUP(sb) / 8); 1248 brelse(bh); 1249 1250 bh = ext4_get_bitmap(sb, group_data->block_bitmap); 1251 if (!bh) 1252 return -EIO; 1253 ext4_block_bitmap_csum_set(sb, group, gdp, bh); 1254 brelse(bh); 1255 1256 return 0; 1257 } 1258 1259 /* 1260 * ext4_setup_new_descs() will set up the group descriptor descriptors of a flex bg 1261 */ 1262 static int ext4_setup_new_descs(handle_t *handle, struct super_block *sb, 1263 struct ext4_new_flex_group_data *flex_gd) 1264 { 1265 struct ext4_new_group_data *group_data = flex_gd->groups; 1266 struct ext4_group_desc *gdp; 1267 struct ext4_sb_info *sbi = EXT4_SB(sb); 1268 struct buffer_head *gdb_bh; 1269 ext4_group_t group; 1270 __u16 *bg_flags = flex_gd->bg_flags; 1271 int i, gdb_off, gdb_num, err = 0; 1272 1273 1274 for (i = 0; i < flex_gd->count; i++, group_data++, bg_flags++) { 1275 group = group_data->group; 1276 1277 gdb_off = group % EXT4_DESC_PER_BLOCK(sb); 1278 gdb_num = group / EXT4_DESC_PER_BLOCK(sb); 1279 1280 /* 1281 * get_write_access() has been called on gdb_bh by ext4_add_new_desc(). 1282 */ 1283 gdb_bh = sbi->s_group_desc[gdb_num]; 1284 /* Update group descriptor block for new group */ 1285 gdp = (struct ext4_group_desc *)(gdb_bh->b_data + 1286 gdb_off * EXT4_DESC_SIZE(sb)); 1287 1288 memset(gdp, 0, EXT4_DESC_SIZE(sb)); 1289 ext4_block_bitmap_set(sb, gdp, group_data->block_bitmap); 1290 ext4_inode_bitmap_set(sb, gdp, group_data->inode_bitmap); 1291 err = ext4_set_bitmap_checksums(sb, group, gdp, group_data); 1292 if (err) { 1293 ext4_std_error(sb, err); 1294 break; 1295 } 1296 1297 ext4_inode_table_set(sb, gdp, group_data->inode_table); 1298 ext4_free_group_clusters_set(sb, gdp, 1299 group_data->free_clusters_count); 1300 ext4_free_inodes_set(sb, gdp, EXT4_INODES_PER_GROUP(sb)); 1301 if (ext4_has_group_desc_csum(sb)) 1302 ext4_itable_unused_set(sb, gdp, 1303 EXT4_INODES_PER_GROUP(sb)); 1304 gdp->bg_flags = cpu_to_le16(*bg_flags); 1305 ext4_group_desc_csum_set(sb, group, gdp); 1306 1307 err = ext4_handle_dirty_metadata(handle, NULL, gdb_bh); 1308 if (unlikely(err)) { 1309 ext4_std_error(sb, err); 1310 break; 1311 } 1312 1313 /* 1314 * We can allocate memory for mb_alloc based on the new group 1315 * descriptor 1316 */ 1317 err = ext4_mb_add_groupinfo(sb, group, gdp); 1318 if (err) 1319 break; 1320 } 1321 return err; 1322 } 1323 1324 /* 1325 * ext4_update_super() updates the super block so that the newly added 1326 * groups can be seen by the filesystem. 1327 * 1328 * @sb: super block 1329 * @flex_gd: new added groups 1330 */ 1331 static void ext4_update_super(struct super_block *sb, 1332 struct ext4_new_flex_group_data *flex_gd) 1333 { 1334 ext4_fsblk_t blocks_count = 0; 1335 ext4_fsblk_t free_blocks = 0; 1336 ext4_fsblk_t reserved_blocks = 0; 1337 struct ext4_new_group_data *group_data = flex_gd->groups; 1338 struct ext4_sb_info *sbi = EXT4_SB(sb); 1339 struct ext4_super_block *es = sbi->s_es; 1340 int i; 1341 1342 BUG_ON(flex_gd->count == 0 || group_data == NULL); 1343 /* 1344 * Make the new blocks and inodes valid next. We do this before 1345 * increasing the group count so that once the group is enabled, 1346 * all of its blocks and inodes are already valid. 1347 * 1348 * We always allocate group-by-group, then block-by-block or 1349 * inode-by-inode within a group, so enabling these 1350 * blocks/inodes before the group is live won't actually let us 1351 * allocate the new space yet. 1352 */ 1353 for (i = 0; i < flex_gd->count; i++) { 1354 blocks_count += group_data[i].blocks_count; 1355 free_blocks += EXT4_C2B(sbi, group_data[i].free_clusters_count); 1356 } 1357 1358 reserved_blocks = ext4_r_blocks_count(es) * 100; 1359 reserved_blocks = div64_u64(reserved_blocks, ext4_blocks_count(es)); 1360 reserved_blocks *= blocks_count; 1361 do_div(reserved_blocks, 100); 1362 1363 ext4_blocks_count_set(es, ext4_blocks_count(es) + blocks_count); 1364 ext4_free_blocks_count_set(es, ext4_free_blocks_count(es) + free_blocks); 1365 le32_add_cpu(&es->s_inodes_count, EXT4_INODES_PER_GROUP(sb) * 1366 flex_gd->count); 1367 le32_add_cpu(&es->s_free_inodes_count, EXT4_INODES_PER_GROUP(sb) * 1368 flex_gd->count); 1369 1370 ext4_debug("free blocks count %llu", ext4_free_blocks_count(es)); 1371 /* 1372 * We need to protect s_groups_count against other CPUs seeing 1373 * inconsistent state in the superblock. 1374 * 1375 * The precise rules we use are: 1376 * 1377 * * Writers must perform a smp_wmb() after updating all 1378 * dependent data and before modifying the groups count 1379 * 1380 * * Readers must perform an smp_rmb() after reading the groups 1381 * count and before reading any dependent data. 1382 * 1383 * NB. These rules can be relaxed when checking the group count 1384 * while freeing data, as we can only allocate from a block 1385 * group after serialising against the group count, and we can 1386 * only then free after serialising in turn against that 1387 * allocation. 1388 */ 1389 smp_wmb(); 1390 1391 /* Update the global fs size fields */ 1392 sbi->s_groups_count += flex_gd->count; 1393 sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count, 1394 (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb))); 1395 1396 /* Update the reserved block counts only once the new group is 1397 * active. */ 1398 ext4_r_blocks_count_set(es, ext4_r_blocks_count(es) + 1399 reserved_blocks); 1400 1401 /* Update the free space counts */ 1402 percpu_counter_add(&sbi->s_freeclusters_counter, 1403 EXT4_NUM_B2C(sbi, free_blocks)); 1404 percpu_counter_add(&sbi->s_freeinodes_counter, 1405 EXT4_INODES_PER_GROUP(sb) * flex_gd->count); 1406 1407 ext4_debug("free blocks count %llu", 1408 percpu_counter_read(&sbi->s_freeclusters_counter)); 1409 if (ext4_has_feature_flex_bg(sb) && sbi->s_log_groups_per_flex) { 1410 ext4_group_t flex_group; 1411 flex_group = ext4_flex_group(sbi, group_data[0].group); 1412 atomic64_add(EXT4_NUM_B2C(sbi, free_blocks), 1413 &sbi->s_flex_groups[flex_group].free_clusters); 1414 atomic_add(EXT4_INODES_PER_GROUP(sb) * flex_gd->count, 1415 &sbi->s_flex_groups[flex_group].free_inodes); 1416 } 1417 1418 /* 1419 * Update the fs overhead information 1420 */ 1421 ext4_calculate_overhead(sb); 1422 1423 if (test_opt(sb, DEBUG)) 1424 printk(KERN_DEBUG "EXT4-fs: added group %u:" 1425 "%llu blocks(%llu free %llu reserved)\n", flex_gd->count, 1426 blocks_count, free_blocks, reserved_blocks); 1427 } 1428 1429 /* Add a flex group to an fs. Ensure we handle all possible error conditions 1430 * _before_ we start modifying the filesystem, because we cannot abort the 1431 * transaction and not have it write the data to disk. 1432 */ 1433 static int ext4_flex_group_add(struct super_block *sb, 1434 struct inode *resize_inode, 1435 struct ext4_new_flex_group_data *flex_gd) 1436 { 1437 struct ext4_sb_info *sbi = EXT4_SB(sb); 1438 struct ext4_super_block *es = sbi->s_es; 1439 ext4_fsblk_t o_blocks_count; 1440 ext4_grpblk_t last; 1441 ext4_group_t group; 1442 handle_t *handle; 1443 unsigned reserved_gdb; 1444 int err = 0, err2 = 0, credit; 1445 1446 BUG_ON(!flex_gd->count || !flex_gd->groups || !flex_gd->bg_flags); 1447 1448 reserved_gdb = le16_to_cpu(es->s_reserved_gdt_blocks); 1449 o_blocks_count = ext4_blocks_count(es); 1450 ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last); 1451 BUG_ON(last); 1452 1453 err = setup_new_flex_group_blocks(sb, flex_gd); 1454 if (err) 1455 goto exit; 1456 /* 1457 * We will always be modifying at least the superblock and GDT 1458 * blocks. If we are adding a group past the last current GDT block, 1459 * we will also modify the inode and the dindirect block. If we 1460 * are adding a group with superblock/GDT backups we will also 1461 * modify each of the reserved GDT dindirect blocks. 1462 */ 1463 credit = 3; /* sb, resize inode, resize inode dindirect */ 1464 /* GDT blocks */ 1465 credit += 1 + DIV_ROUND_UP(flex_gd->count, EXT4_DESC_PER_BLOCK(sb)); 1466 credit += reserved_gdb; /* Reserved GDT dindirect blocks */ 1467 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, credit); 1468 if (IS_ERR(handle)) { 1469 err = PTR_ERR(handle); 1470 goto exit; 1471 } 1472 1473 BUFFER_TRACE(sbi->s_sbh, "get_write_access"); 1474 err = ext4_journal_get_write_access(handle, sbi->s_sbh); 1475 if (err) 1476 goto exit_journal; 1477 1478 group = flex_gd->groups[0].group; 1479 BUG_ON(group != EXT4_SB(sb)->s_groups_count); 1480 err = ext4_add_new_descs(handle, sb, group, 1481 resize_inode, flex_gd->count); 1482 if (err) 1483 goto exit_journal; 1484 1485 err = ext4_setup_new_descs(handle, sb, flex_gd); 1486 if (err) 1487 goto exit_journal; 1488 1489 ext4_update_super(sb, flex_gd); 1490 1491 err = ext4_handle_dirty_super(handle, sb); 1492 1493 exit_journal: 1494 err2 = ext4_journal_stop(handle); 1495 if (!err) 1496 err = err2; 1497 1498 if (!err) { 1499 int gdb_num = group / EXT4_DESC_PER_BLOCK(sb); 1500 int gdb_num_end = ((group + flex_gd->count - 1) / 1501 EXT4_DESC_PER_BLOCK(sb)); 1502 int meta_bg = ext4_has_feature_meta_bg(sb); 1503 sector_t old_gdb = 0; 1504 1505 update_backups(sb, sbi->s_sbh->b_blocknr, (char *)es, 1506 sizeof(struct ext4_super_block), 0); 1507 for (; gdb_num <= gdb_num_end; gdb_num++) { 1508 struct buffer_head *gdb_bh; 1509 1510 gdb_bh = sbi->s_group_desc[gdb_num]; 1511 if (old_gdb == gdb_bh->b_blocknr) 1512 continue; 1513 update_backups(sb, gdb_bh->b_blocknr, gdb_bh->b_data, 1514 gdb_bh->b_size, meta_bg); 1515 old_gdb = gdb_bh->b_blocknr; 1516 } 1517 } 1518 exit: 1519 return err; 1520 } 1521 1522 static int ext4_setup_next_flex_gd(struct super_block *sb, 1523 struct ext4_new_flex_group_data *flex_gd, 1524 ext4_fsblk_t n_blocks_count, 1525 unsigned long flexbg_size) 1526 { 1527 struct ext4_sb_info *sbi = EXT4_SB(sb); 1528 struct ext4_super_block *es = sbi->s_es; 1529 struct ext4_new_group_data *group_data = flex_gd->groups; 1530 ext4_fsblk_t o_blocks_count; 1531 ext4_group_t n_group; 1532 ext4_group_t group; 1533 ext4_group_t last_group; 1534 ext4_grpblk_t last; 1535 ext4_grpblk_t clusters_per_group; 1536 unsigned long i; 1537 1538 clusters_per_group = EXT4_CLUSTERS_PER_GROUP(sb); 1539 1540 o_blocks_count = ext4_blocks_count(es); 1541 1542 if (o_blocks_count == n_blocks_count) 1543 return 0; 1544 1545 ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last); 1546 BUG_ON(last); 1547 ext4_get_group_no_and_offset(sb, n_blocks_count - 1, &n_group, &last); 1548 1549 last_group = group | (flexbg_size - 1); 1550 if (last_group > n_group) 1551 last_group = n_group; 1552 1553 flex_gd->count = last_group - group + 1; 1554 1555 for (i = 0; i < flex_gd->count; i++) { 1556 int overhead; 1557 1558 group_data[i].group = group + i; 1559 group_data[i].blocks_count = EXT4_BLOCKS_PER_GROUP(sb); 1560 overhead = ext4_group_overhead_blocks(sb, group + i); 1561 group_data[i].mdata_blocks = overhead; 1562 group_data[i].free_clusters_count = EXT4_CLUSTERS_PER_GROUP(sb); 1563 if (ext4_has_group_desc_csum(sb)) { 1564 flex_gd->bg_flags[i] = EXT4_BG_BLOCK_UNINIT | 1565 EXT4_BG_INODE_UNINIT; 1566 if (!test_opt(sb, INIT_INODE_TABLE)) 1567 flex_gd->bg_flags[i] |= EXT4_BG_INODE_ZEROED; 1568 } else 1569 flex_gd->bg_flags[i] = EXT4_BG_INODE_ZEROED; 1570 } 1571 1572 if (last_group == n_group && ext4_has_group_desc_csum(sb)) 1573 /* We need to initialize block bitmap of last group. */ 1574 flex_gd->bg_flags[i - 1] &= ~EXT4_BG_BLOCK_UNINIT; 1575 1576 if ((last_group == n_group) && (last != clusters_per_group - 1)) { 1577 group_data[i - 1].blocks_count = EXT4_C2B(sbi, last + 1); 1578 group_data[i - 1].free_clusters_count -= clusters_per_group - 1579 last - 1; 1580 } 1581 1582 return 1; 1583 } 1584 1585 /* Add group descriptor data to an existing or new group descriptor block. 1586 * Ensure we handle all possible error conditions _before_ we start modifying 1587 * the filesystem, because we cannot abort the transaction and not have it 1588 * write the data to disk. 1589 * 1590 * If we are on a GDT block boundary, we need to get the reserved GDT block. 1591 * Otherwise, we may need to add backup GDT blocks for a sparse group. 1592 * 1593 * We only need to hold the superblock lock while we are actually adding 1594 * in the new group's counts to the superblock. Prior to that we have 1595 * not really "added" the group at all. We re-check that we are still 1596 * adding in the last group in case things have changed since verifying. 1597 */ 1598 int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input) 1599 { 1600 struct ext4_new_flex_group_data flex_gd; 1601 struct ext4_sb_info *sbi = EXT4_SB(sb); 1602 struct ext4_super_block *es = sbi->s_es; 1603 int reserved_gdb = ext4_bg_has_super(sb, input->group) ? 1604 le16_to_cpu(es->s_reserved_gdt_blocks) : 0; 1605 struct inode *inode = NULL; 1606 int gdb_off; 1607 int err; 1608 __u16 bg_flags = 0; 1609 1610 gdb_off = input->group % EXT4_DESC_PER_BLOCK(sb); 1611 1612 if (gdb_off == 0 && !ext4_has_feature_sparse_super(sb)) { 1613 ext4_warning(sb, "Can't resize non-sparse filesystem further"); 1614 return -EPERM; 1615 } 1616 1617 if (ext4_blocks_count(es) + input->blocks_count < 1618 ext4_blocks_count(es)) { 1619 ext4_warning(sb, "blocks_count overflow"); 1620 return -EINVAL; 1621 } 1622 1623 if (le32_to_cpu(es->s_inodes_count) + EXT4_INODES_PER_GROUP(sb) < 1624 le32_to_cpu(es->s_inodes_count)) { 1625 ext4_warning(sb, "inodes_count overflow"); 1626 return -EINVAL; 1627 } 1628 1629 if (reserved_gdb || gdb_off == 0) { 1630 if (ext4_has_feature_resize_inode(sb) || 1631 !le16_to_cpu(es->s_reserved_gdt_blocks)) { 1632 ext4_warning(sb, 1633 "No reserved GDT blocks, can't resize"); 1634 return -EPERM; 1635 } 1636 inode = ext4_iget(sb, EXT4_RESIZE_INO); 1637 if (IS_ERR(inode)) { 1638 ext4_warning(sb, "Error opening resize inode"); 1639 return PTR_ERR(inode); 1640 } 1641 } 1642 1643 1644 err = verify_group_input(sb, input); 1645 if (err) 1646 goto out; 1647 1648 err = ext4_alloc_flex_bg_array(sb, input->group + 1); 1649 if (err) 1650 goto out; 1651 1652 err = ext4_mb_alloc_groupinfo(sb, input->group + 1); 1653 if (err) 1654 goto out; 1655 1656 flex_gd.count = 1; 1657 flex_gd.groups = input; 1658 flex_gd.bg_flags = &bg_flags; 1659 err = ext4_flex_group_add(sb, inode, &flex_gd); 1660 out: 1661 iput(inode); 1662 return err; 1663 } /* ext4_group_add */ 1664 1665 /* 1666 * extend a group without checking assuming that checking has been done. 1667 */ 1668 static int ext4_group_extend_no_check(struct super_block *sb, 1669 ext4_fsblk_t o_blocks_count, ext4_grpblk_t add) 1670 { 1671 struct ext4_super_block *es = EXT4_SB(sb)->s_es; 1672 handle_t *handle; 1673 int err = 0, err2; 1674 1675 /* We will update the superblock, one block bitmap, and 1676 * one group descriptor via ext4_group_add_blocks(). 1677 */ 1678 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, 3); 1679 if (IS_ERR(handle)) { 1680 err = PTR_ERR(handle); 1681 ext4_warning(sb, "error %d on journal start", err); 1682 return err; 1683 } 1684 1685 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access"); 1686 err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh); 1687 if (err) { 1688 ext4_warning(sb, "error %d on journal write access", err); 1689 goto errout; 1690 } 1691 1692 ext4_blocks_count_set(es, o_blocks_count + add); 1693 ext4_free_blocks_count_set(es, ext4_free_blocks_count(es) + add); 1694 ext4_debug("freeing blocks %llu through %llu\n", o_blocks_count, 1695 o_blocks_count + add); 1696 /* We add the blocks to the bitmap and set the group need init bit */ 1697 err = ext4_group_add_blocks(handle, sb, o_blocks_count, add); 1698 if (err) 1699 goto errout; 1700 ext4_handle_dirty_super(handle, sb); 1701 ext4_debug("freed blocks %llu through %llu\n", o_blocks_count, 1702 o_blocks_count + add); 1703 errout: 1704 err2 = ext4_journal_stop(handle); 1705 if (err2 && !err) 1706 err = err2; 1707 1708 if (!err) { 1709 if (test_opt(sb, DEBUG)) 1710 printk(KERN_DEBUG "EXT4-fs: extended group to %llu " 1711 "blocks\n", ext4_blocks_count(es)); 1712 update_backups(sb, EXT4_SB(sb)->s_sbh->b_blocknr, 1713 (char *)es, sizeof(struct ext4_super_block), 0); 1714 } 1715 return err; 1716 } 1717 1718 /* 1719 * Extend the filesystem to the new number of blocks specified. This entry 1720 * point is only used to extend the current filesystem to the end of the last 1721 * existing group. It can be accessed via ioctl, or by "remount,resize=<size>" 1722 * for emergencies (because it has no dependencies on reserved blocks). 1723 * 1724 * If we _really_ wanted, we could use default values to call ext4_group_add() 1725 * allow the "remount" trick to work for arbitrary resizing, assuming enough 1726 * GDT blocks are reserved to grow to the desired size. 1727 */ 1728 int ext4_group_extend(struct super_block *sb, struct ext4_super_block *es, 1729 ext4_fsblk_t n_blocks_count) 1730 { 1731 ext4_fsblk_t o_blocks_count; 1732 ext4_grpblk_t last; 1733 ext4_grpblk_t add; 1734 struct buffer_head *bh; 1735 int err; 1736 ext4_group_t group; 1737 1738 o_blocks_count = ext4_blocks_count(es); 1739 1740 if (test_opt(sb, DEBUG)) 1741 ext4_msg(sb, KERN_DEBUG, 1742 "extending last group from %llu to %llu blocks", 1743 o_blocks_count, n_blocks_count); 1744 1745 if (n_blocks_count == 0 || n_blocks_count == o_blocks_count) 1746 return 0; 1747 1748 if (n_blocks_count > (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) { 1749 ext4_msg(sb, KERN_ERR, 1750 "filesystem too large to resize to %llu blocks safely", 1751 n_blocks_count); 1752 if (sizeof(sector_t) < 8) 1753 ext4_warning(sb, "CONFIG_LBDAF not enabled"); 1754 return -EINVAL; 1755 } 1756 1757 if (n_blocks_count < o_blocks_count) { 1758 ext4_warning(sb, "can't shrink FS - resize aborted"); 1759 return -EINVAL; 1760 } 1761 1762 /* Handle the remaining blocks in the last group only. */ 1763 ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last); 1764 1765 if (last == 0) { 1766 ext4_warning(sb, "need to use ext2online to resize further"); 1767 return -EPERM; 1768 } 1769 1770 add = EXT4_BLOCKS_PER_GROUP(sb) - last; 1771 1772 if (o_blocks_count + add < o_blocks_count) { 1773 ext4_warning(sb, "blocks_count overflow"); 1774 return -EINVAL; 1775 } 1776 1777 if (o_blocks_count + add > n_blocks_count) 1778 add = n_blocks_count - o_blocks_count; 1779 1780 if (o_blocks_count + add < n_blocks_count) 1781 ext4_warning(sb, "will only finish group (%llu blocks, %u new)", 1782 o_blocks_count + add, add); 1783 1784 /* See if the device is actually as big as what was requested */ 1785 bh = sb_bread(sb, o_blocks_count + add - 1); 1786 if (!bh) { 1787 ext4_warning(sb, "can't read last block, resize aborted"); 1788 return -ENOSPC; 1789 } 1790 brelse(bh); 1791 1792 err = ext4_group_extend_no_check(sb, o_blocks_count, add); 1793 return err; 1794 } /* ext4_group_extend */ 1795 1796 1797 static int num_desc_blocks(struct super_block *sb, ext4_group_t groups) 1798 { 1799 return (groups + EXT4_DESC_PER_BLOCK(sb) - 1) / EXT4_DESC_PER_BLOCK(sb); 1800 } 1801 1802 /* 1803 * Release the resize inode and drop the resize_inode feature if there 1804 * are no more reserved gdt blocks, and then convert the file system 1805 * to enable meta_bg 1806 */ 1807 static int ext4_convert_meta_bg(struct super_block *sb, struct inode *inode) 1808 { 1809 handle_t *handle; 1810 struct ext4_sb_info *sbi = EXT4_SB(sb); 1811 struct ext4_super_block *es = sbi->s_es; 1812 struct ext4_inode_info *ei = EXT4_I(inode); 1813 ext4_fsblk_t nr; 1814 int i, ret, err = 0; 1815 int credits = 1; 1816 1817 ext4_msg(sb, KERN_INFO, "Converting file system to meta_bg"); 1818 if (inode) { 1819 if (es->s_reserved_gdt_blocks) { 1820 ext4_error(sb, "Unexpected non-zero " 1821 "s_reserved_gdt_blocks"); 1822 return -EPERM; 1823 } 1824 1825 /* Do a quick sanity check of the resize inode */ 1826 if (inode->i_blocks != 1 << (inode->i_blkbits - 1827 (9 - sbi->s_cluster_bits))) 1828 goto invalid_resize_inode; 1829 for (i = 0; i < EXT4_N_BLOCKS; i++) { 1830 if (i == EXT4_DIND_BLOCK) { 1831 if (ei->i_data[i]) 1832 continue; 1833 else 1834 goto invalid_resize_inode; 1835 } 1836 if (ei->i_data[i]) 1837 goto invalid_resize_inode; 1838 } 1839 credits += 3; /* block bitmap, bg descriptor, resize inode */ 1840 } 1841 1842 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, credits); 1843 if (IS_ERR(handle)) 1844 return PTR_ERR(handle); 1845 1846 BUFFER_TRACE(sbi->s_sbh, "get_write_access"); 1847 err = ext4_journal_get_write_access(handle, sbi->s_sbh); 1848 if (err) 1849 goto errout; 1850 1851 ext4_clear_feature_resize_inode(sb); 1852 ext4_set_feature_meta_bg(sb); 1853 sbi->s_es->s_first_meta_bg = 1854 cpu_to_le32(num_desc_blocks(sb, sbi->s_groups_count)); 1855 1856 err = ext4_handle_dirty_super(handle, sb); 1857 if (err) { 1858 ext4_std_error(sb, err); 1859 goto errout; 1860 } 1861 1862 if (inode) { 1863 nr = le32_to_cpu(ei->i_data[EXT4_DIND_BLOCK]); 1864 ext4_free_blocks(handle, inode, NULL, nr, 1, 1865 EXT4_FREE_BLOCKS_METADATA | 1866 EXT4_FREE_BLOCKS_FORGET); 1867 ei->i_data[EXT4_DIND_BLOCK] = 0; 1868 inode->i_blocks = 0; 1869 1870 err = ext4_mark_inode_dirty(handle, inode); 1871 if (err) 1872 ext4_std_error(sb, err); 1873 } 1874 1875 errout: 1876 ret = ext4_journal_stop(handle); 1877 if (!err) 1878 err = ret; 1879 return ret; 1880 1881 invalid_resize_inode: 1882 ext4_error(sb, "corrupted/inconsistent resize inode"); 1883 return -EINVAL; 1884 } 1885 1886 /* 1887 * ext4_resize_fs() resizes a fs to new size specified by @n_blocks_count 1888 * 1889 * @sb: super block of the fs to be resized 1890 * @n_blocks_count: the number of blocks resides in the resized fs 1891 */ 1892 int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count) 1893 { 1894 struct ext4_new_flex_group_data *flex_gd = NULL; 1895 struct ext4_sb_info *sbi = EXT4_SB(sb); 1896 struct ext4_super_block *es = sbi->s_es; 1897 struct buffer_head *bh; 1898 struct inode *resize_inode = NULL; 1899 ext4_grpblk_t add, offset; 1900 unsigned long n_desc_blocks; 1901 unsigned long o_desc_blocks; 1902 ext4_group_t o_group; 1903 ext4_group_t n_group; 1904 ext4_fsblk_t o_blocks_count; 1905 ext4_fsblk_t n_blocks_count_retry = 0; 1906 unsigned long last_update_time = 0; 1907 int err = 0, flexbg_size = 1 << sbi->s_log_groups_per_flex; 1908 int meta_bg; 1909 1910 /* See if the device is actually as big as what was requested */ 1911 bh = sb_bread(sb, n_blocks_count - 1); 1912 if (!bh) { 1913 ext4_warning(sb, "can't read last block, resize aborted"); 1914 return -ENOSPC; 1915 } 1916 brelse(bh); 1917 1918 retry: 1919 o_blocks_count = ext4_blocks_count(es); 1920 1921 ext4_msg(sb, KERN_INFO, "resizing filesystem from %llu " 1922 "to %llu blocks", o_blocks_count, n_blocks_count); 1923 1924 if (n_blocks_count < o_blocks_count) { 1925 /* On-line shrinking not supported */ 1926 ext4_warning(sb, "can't shrink FS - resize aborted"); 1927 return -EINVAL; 1928 } 1929 1930 if (n_blocks_count == o_blocks_count) 1931 /* Nothing need to do */ 1932 return 0; 1933 1934 n_group = ext4_get_group_number(sb, n_blocks_count - 1); 1935 if (n_group > (0xFFFFFFFFUL / EXT4_INODES_PER_GROUP(sb))) { 1936 ext4_warning(sb, "resize would cause inodes_count overflow"); 1937 return -EINVAL; 1938 } 1939 ext4_get_group_no_and_offset(sb, o_blocks_count - 1, &o_group, &offset); 1940 1941 n_desc_blocks = num_desc_blocks(sb, n_group + 1); 1942 o_desc_blocks = num_desc_blocks(sb, sbi->s_groups_count); 1943 1944 meta_bg = ext4_has_feature_meta_bg(sb); 1945 1946 if (ext4_has_feature_resize_inode(sb)) { 1947 if (meta_bg) { 1948 ext4_error(sb, "resize_inode and meta_bg enabled " 1949 "simultaneously"); 1950 return -EINVAL; 1951 } 1952 if (n_desc_blocks > o_desc_blocks + 1953 le16_to_cpu(es->s_reserved_gdt_blocks)) { 1954 n_blocks_count_retry = n_blocks_count; 1955 n_desc_blocks = o_desc_blocks + 1956 le16_to_cpu(es->s_reserved_gdt_blocks); 1957 n_group = n_desc_blocks * EXT4_DESC_PER_BLOCK(sb); 1958 n_blocks_count = (ext4_fsblk_t)n_group * 1959 EXT4_BLOCKS_PER_GROUP(sb); 1960 n_group--; /* set to last group number */ 1961 } 1962 1963 if (!resize_inode) 1964 resize_inode = ext4_iget(sb, EXT4_RESIZE_INO); 1965 if (IS_ERR(resize_inode)) { 1966 ext4_warning(sb, "Error opening resize inode"); 1967 return PTR_ERR(resize_inode); 1968 } 1969 } 1970 1971 if ((!resize_inode && !meta_bg) || n_blocks_count == o_blocks_count) { 1972 err = ext4_convert_meta_bg(sb, resize_inode); 1973 if (err) 1974 goto out; 1975 if (resize_inode) { 1976 iput(resize_inode); 1977 resize_inode = NULL; 1978 } 1979 if (n_blocks_count_retry) { 1980 n_blocks_count = n_blocks_count_retry; 1981 n_blocks_count_retry = 0; 1982 goto retry; 1983 } 1984 } 1985 1986 /* extend the last group */ 1987 if (n_group == o_group) 1988 add = n_blocks_count - o_blocks_count; 1989 else 1990 add = EXT4_C2B(sbi, EXT4_CLUSTERS_PER_GROUP(sb) - (offset + 1)); 1991 if (add > 0) { 1992 err = ext4_group_extend_no_check(sb, o_blocks_count, add); 1993 if (err) 1994 goto out; 1995 } 1996 1997 if (ext4_blocks_count(es) == n_blocks_count) 1998 goto out; 1999 2000 err = ext4_alloc_flex_bg_array(sb, n_group + 1); 2001 if (err) 2002 return err; 2003 2004 err = ext4_mb_alloc_groupinfo(sb, n_group + 1); 2005 if (err) 2006 goto out; 2007 2008 flex_gd = alloc_flex_gd(flexbg_size); 2009 if (flex_gd == NULL) { 2010 err = -ENOMEM; 2011 goto out; 2012 } 2013 2014 /* Add flex groups. Note that a regular group is a 2015 * flex group with 1 group. 2016 */ 2017 while (ext4_setup_next_flex_gd(sb, flex_gd, n_blocks_count, 2018 flexbg_size)) { 2019 if (jiffies - last_update_time > HZ * 10) { 2020 if (last_update_time) 2021 ext4_msg(sb, KERN_INFO, 2022 "resized to %llu blocks", 2023 ext4_blocks_count(es)); 2024 last_update_time = jiffies; 2025 } 2026 if (ext4_alloc_group_tables(sb, flex_gd, flexbg_size) != 0) 2027 break; 2028 err = ext4_flex_group_add(sb, resize_inode, flex_gd); 2029 if (unlikely(err)) 2030 break; 2031 } 2032 2033 if (!err && n_blocks_count_retry) { 2034 n_blocks_count = n_blocks_count_retry; 2035 n_blocks_count_retry = 0; 2036 free_flex_gd(flex_gd); 2037 flex_gd = NULL; 2038 goto retry; 2039 } 2040 2041 out: 2042 if (flex_gd) 2043 free_flex_gd(flex_gd); 2044 if (resize_inode != NULL) 2045 iput(resize_inode); 2046 ext4_msg(sb, KERN_INFO, "resized filesystem to %llu", n_blocks_count); 2047 return err; 2048 } 2049