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 * We are not allowed to do online-resizing on a filesystem mounted 28 * with error, because it can destroy the filesystem easily. 29 */ 30 if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) { 31 ext4_warning(sb, "There are errors in the filesystem, " 32 "so online resizing is not allowed\n"); 33 return -EPERM; 34 } 35 36 if (test_and_set_bit_lock(EXT4_RESIZING, &EXT4_SB(sb)->s_resize_flags)) 37 ret = -EBUSY; 38 39 return ret; 40 } 41 42 void ext4_resize_end(struct super_block *sb) 43 { 44 clear_bit_unlock(EXT4_RESIZING, &EXT4_SB(sb)->s_resize_flags); 45 smp_mb__after_clear_bit(); 46 } 47 48 #define outside(b, first, last) ((b) < (first) || (b) >= (last)) 49 #define inside(b, first, last) ((b) >= (first) && (b) < (last)) 50 51 static int verify_group_input(struct super_block *sb, 52 struct ext4_new_group_data *input) 53 { 54 struct ext4_sb_info *sbi = EXT4_SB(sb); 55 struct ext4_super_block *es = sbi->s_es; 56 ext4_fsblk_t start = ext4_blocks_count(es); 57 ext4_fsblk_t end = start + input->blocks_count; 58 ext4_group_t group = input->group; 59 ext4_fsblk_t itend = input->inode_table + sbi->s_itb_per_group; 60 unsigned overhead = ext4_bg_has_super(sb, group) ? 61 (1 + ext4_bg_num_gdb(sb, group) + 62 le16_to_cpu(es->s_reserved_gdt_blocks)) : 0; 63 ext4_fsblk_t metaend = start + overhead; 64 struct buffer_head *bh = NULL; 65 ext4_grpblk_t free_blocks_count, offset; 66 int err = -EINVAL; 67 68 input->free_blocks_count = free_blocks_count = 69 input->blocks_count - 2 - overhead - sbi->s_itb_per_group; 70 71 if (test_opt(sb, DEBUG)) 72 printk(KERN_DEBUG "EXT4-fs: adding %s group %u: %u blocks " 73 "(%d free, %u reserved)\n", 74 ext4_bg_has_super(sb, input->group) ? "normal" : 75 "no-super", input->group, input->blocks_count, 76 free_blocks_count, input->reserved_blocks); 77 78 ext4_get_group_no_and_offset(sb, start, NULL, &offset); 79 if (group != sbi->s_groups_count) 80 ext4_warning(sb, "Cannot add at group %u (only %u groups)", 81 input->group, sbi->s_groups_count); 82 else if (offset != 0) 83 ext4_warning(sb, "Last group not full"); 84 else if (input->reserved_blocks > input->blocks_count / 5) 85 ext4_warning(sb, "Reserved blocks too high (%u)", 86 input->reserved_blocks); 87 else if (free_blocks_count < 0) 88 ext4_warning(sb, "Bad blocks count %u", 89 input->blocks_count); 90 else if (!(bh = sb_bread(sb, end - 1))) 91 ext4_warning(sb, "Cannot read last block (%llu)", 92 end - 1); 93 else if (outside(input->block_bitmap, start, end)) 94 ext4_warning(sb, "Block bitmap not in group (block %llu)", 95 (unsigned long long)input->block_bitmap); 96 else if (outside(input->inode_bitmap, start, end)) 97 ext4_warning(sb, "Inode bitmap not in group (block %llu)", 98 (unsigned long long)input->inode_bitmap); 99 else if (outside(input->inode_table, start, end) || 100 outside(itend - 1, start, end)) 101 ext4_warning(sb, "Inode table not in group (blocks %llu-%llu)", 102 (unsigned long long)input->inode_table, itend - 1); 103 else if (input->inode_bitmap == input->block_bitmap) 104 ext4_warning(sb, "Block bitmap same as inode bitmap (%llu)", 105 (unsigned long long)input->block_bitmap); 106 else if (inside(input->block_bitmap, input->inode_table, itend)) 107 ext4_warning(sb, "Block bitmap (%llu) in inode table " 108 "(%llu-%llu)", 109 (unsigned long long)input->block_bitmap, 110 (unsigned long long)input->inode_table, itend - 1); 111 else if (inside(input->inode_bitmap, input->inode_table, itend)) 112 ext4_warning(sb, "Inode bitmap (%llu) in inode table " 113 "(%llu-%llu)", 114 (unsigned long long)input->inode_bitmap, 115 (unsigned long long)input->inode_table, itend - 1); 116 else if (inside(input->block_bitmap, start, metaend)) 117 ext4_warning(sb, "Block bitmap (%llu) in GDT table (%llu-%llu)", 118 (unsigned long long)input->block_bitmap, 119 start, metaend - 1); 120 else if (inside(input->inode_bitmap, start, metaend)) 121 ext4_warning(sb, "Inode bitmap (%llu) in GDT table (%llu-%llu)", 122 (unsigned long long)input->inode_bitmap, 123 start, metaend - 1); 124 else if (inside(input->inode_table, start, metaend) || 125 inside(itend - 1, start, metaend)) 126 ext4_warning(sb, "Inode table (%llu-%llu) overlaps GDT table " 127 "(%llu-%llu)", 128 (unsigned long long)input->inode_table, 129 itend - 1, start, metaend - 1); 130 else 131 err = 0; 132 brelse(bh); 133 134 return err; 135 } 136 137 /* 138 * ext4_new_flex_group_data is used by 64bit-resize interface to add a flex 139 * group each time. 140 */ 141 struct ext4_new_flex_group_data { 142 struct ext4_new_group_data *groups; /* new_group_data for groups 143 in the flex group */ 144 __u16 *bg_flags; /* block group flags of groups 145 in @groups */ 146 ext4_group_t count; /* number of groups in @groups 147 */ 148 }; 149 150 /* 151 * alloc_flex_gd() allocates a ext4_new_flex_group_data with size of 152 * @flexbg_size. 153 * 154 * Returns NULL on failure otherwise address of the allocated structure. 155 */ 156 static struct ext4_new_flex_group_data *alloc_flex_gd(unsigned long flexbg_size) 157 { 158 struct ext4_new_flex_group_data *flex_gd; 159 160 flex_gd = kmalloc(sizeof(*flex_gd), GFP_NOFS); 161 if (flex_gd == NULL) 162 goto out3; 163 164 if (flexbg_size >= UINT_MAX / sizeof(struct ext4_new_flex_group_data)) 165 goto out2; 166 flex_gd->count = flexbg_size; 167 168 flex_gd->groups = kmalloc(sizeof(struct ext4_new_group_data) * 169 flexbg_size, GFP_NOFS); 170 if (flex_gd->groups == NULL) 171 goto out2; 172 173 flex_gd->bg_flags = kmalloc(flexbg_size * sizeof(__u16), GFP_NOFS); 174 if (flex_gd->bg_flags == NULL) 175 goto out1; 176 177 return flex_gd; 178 179 out1: 180 kfree(flex_gd->groups); 181 out2: 182 kfree(flex_gd); 183 out3: 184 return NULL; 185 } 186 187 static void free_flex_gd(struct ext4_new_flex_group_data *flex_gd) 188 { 189 kfree(flex_gd->bg_flags); 190 kfree(flex_gd->groups); 191 kfree(flex_gd); 192 } 193 194 /* 195 * ext4_alloc_group_tables() allocates block bitmaps, inode bitmaps 196 * and inode tables for a flex group. 197 * 198 * This function is used by 64bit-resize. Note that this function allocates 199 * group tables from the 1st group of groups contained by @flexgd, which may 200 * be a partial of a flex group. 201 * 202 * @sb: super block of fs to which the groups belongs 203 * 204 * Returns 0 on a successful allocation of the metadata blocks in the 205 * block group. 206 */ 207 static int ext4_alloc_group_tables(struct super_block *sb, 208 struct ext4_new_flex_group_data *flex_gd, 209 int flexbg_size) 210 { 211 struct ext4_new_group_data *group_data = flex_gd->groups; 212 struct ext4_super_block *es = EXT4_SB(sb)->s_es; 213 ext4_fsblk_t start_blk; 214 ext4_fsblk_t last_blk; 215 ext4_group_t src_group; 216 ext4_group_t bb_index = 0; 217 ext4_group_t ib_index = 0; 218 ext4_group_t it_index = 0; 219 ext4_group_t group; 220 ext4_group_t last_group; 221 unsigned overhead; 222 223 BUG_ON(flex_gd->count == 0 || group_data == NULL); 224 225 src_group = group_data[0].group; 226 last_group = src_group + flex_gd->count - 1; 227 228 BUG_ON((flexbg_size > 1) && ((src_group & ~(flexbg_size - 1)) != 229 (last_group & ~(flexbg_size - 1)))); 230 next_group: 231 group = group_data[0].group; 232 if (src_group >= group_data[0].group + flex_gd->count) 233 return -ENOSPC; 234 start_blk = ext4_group_first_block_no(sb, src_group); 235 last_blk = start_blk + group_data[src_group - group].blocks_count; 236 237 overhead = ext4_bg_has_super(sb, src_group) ? 238 (1 + ext4_bg_num_gdb(sb, src_group) + 239 le16_to_cpu(es->s_reserved_gdt_blocks)) : 0; 240 241 start_blk += overhead; 242 243 /* We collect contiguous blocks as much as possible. */ 244 src_group++; 245 for (; src_group <= last_group; src_group++) 246 if (!ext4_bg_has_super(sb, src_group)) 247 last_blk += group_data[src_group - group].blocks_count; 248 else 249 break; 250 251 /* Allocate block bitmaps */ 252 for (; bb_index < flex_gd->count; bb_index++) { 253 if (start_blk >= last_blk) 254 goto next_group; 255 group_data[bb_index].block_bitmap = start_blk++; 256 ext4_get_group_no_and_offset(sb, start_blk - 1, &group, NULL); 257 group -= group_data[0].group; 258 group_data[group].free_blocks_count--; 259 if (flexbg_size > 1) 260 flex_gd->bg_flags[group] &= ~EXT4_BG_BLOCK_UNINIT; 261 } 262 263 /* Allocate inode bitmaps */ 264 for (; ib_index < flex_gd->count; ib_index++) { 265 if (start_blk >= last_blk) 266 goto next_group; 267 group_data[ib_index].inode_bitmap = start_blk++; 268 ext4_get_group_no_and_offset(sb, start_blk - 1, &group, NULL); 269 group -= group_data[0].group; 270 group_data[group].free_blocks_count--; 271 if (flexbg_size > 1) 272 flex_gd->bg_flags[group] &= ~EXT4_BG_BLOCK_UNINIT; 273 } 274 275 /* Allocate inode tables */ 276 for (; it_index < flex_gd->count; it_index++) { 277 if (start_blk + EXT4_SB(sb)->s_itb_per_group > last_blk) 278 goto next_group; 279 group_data[it_index].inode_table = start_blk; 280 ext4_get_group_no_and_offset(sb, start_blk, &group, NULL); 281 group -= group_data[0].group; 282 group_data[group].free_blocks_count -= 283 EXT4_SB(sb)->s_itb_per_group; 284 if (flexbg_size > 1) 285 flex_gd->bg_flags[group] &= ~EXT4_BG_BLOCK_UNINIT; 286 287 start_blk += EXT4_SB(sb)->s_itb_per_group; 288 } 289 290 if (test_opt(sb, DEBUG)) { 291 int i; 292 group = group_data[0].group; 293 294 printk(KERN_DEBUG "EXT4-fs: adding a flex group with " 295 "%d groups, flexbg size is %d:\n", flex_gd->count, 296 flexbg_size); 297 298 for (i = 0; i < flex_gd->count; i++) { 299 printk(KERN_DEBUG "adding %s group %u: %u " 300 "blocks (%d free)\n", 301 ext4_bg_has_super(sb, group + i) ? "normal" : 302 "no-super", group + i, 303 group_data[i].blocks_count, 304 group_data[i].free_blocks_count); 305 } 306 } 307 return 0; 308 } 309 310 static struct buffer_head *bclean(handle_t *handle, struct super_block *sb, 311 ext4_fsblk_t blk) 312 { 313 struct buffer_head *bh; 314 int err; 315 316 bh = sb_getblk(sb, blk); 317 if (!bh) 318 return ERR_PTR(-EIO); 319 if ((err = ext4_journal_get_write_access(handle, bh))) { 320 brelse(bh); 321 bh = ERR_PTR(err); 322 } else { 323 memset(bh->b_data, 0, sb->s_blocksize); 324 set_buffer_uptodate(bh); 325 } 326 327 return bh; 328 } 329 330 /* 331 * If we have fewer than thresh credits, extend by EXT4_MAX_TRANS_DATA. 332 * If that fails, restart the transaction & regain write access for the 333 * buffer head which is used for block_bitmap modifications. 334 */ 335 static int extend_or_restart_transaction(handle_t *handle, int thresh) 336 { 337 int err; 338 339 if (ext4_handle_has_enough_credits(handle, thresh)) 340 return 0; 341 342 err = ext4_journal_extend(handle, EXT4_MAX_TRANS_DATA); 343 if (err < 0) 344 return err; 345 if (err) { 346 err = ext4_journal_restart(handle, EXT4_MAX_TRANS_DATA); 347 if (err) 348 return err; 349 } 350 351 return 0; 352 } 353 354 /* 355 * set_flexbg_block_bitmap() mark @count blocks starting from @block used. 356 * 357 * Helper function for ext4_setup_new_group_blocks() which set . 358 * 359 * @sb: super block 360 * @handle: journal handle 361 * @flex_gd: flex group data 362 */ 363 static int set_flexbg_block_bitmap(struct super_block *sb, handle_t *handle, 364 struct ext4_new_flex_group_data *flex_gd, 365 ext4_fsblk_t block, ext4_group_t count) 366 { 367 ext4_group_t count2; 368 369 ext4_debug("mark blocks [%llu/%u] used\n", block, count); 370 for (count2 = count; count > 0; count -= count2, block += count2) { 371 ext4_fsblk_t start; 372 struct buffer_head *bh; 373 ext4_group_t group; 374 int err; 375 376 ext4_get_group_no_and_offset(sb, block, &group, NULL); 377 start = ext4_group_first_block_no(sb, group); 378 group -= flex_gd->groups[0].group; 379 380 count2 = sb->s_blocksize * 8 - (block - start); 381 if (count2 > count) 382 count2 = count; 383 384 if (flex_gd->bg_flags[group] & EXT4_BG_BLOCK_UNINIT) { 385 BUG_ON(flex_gd->count > 1); 386 continue; 387 } 388 389 err = extend_or_restart_transaction(handle, 1); 390 if (err) 391 return err; 392 393 bh = sb_getblk(sb, flex_gd->groups[group].block_bitmap); 394 if (!bh) 395 return -EIO; 396 397 err = ext4_journal_get_write_access(handle, bh); 398 if (err) 399 return err; 400 ext4_debug("mark block bitmap %#04llx (+%llu/%u)\n", block, 401 block - start, count2); 402 ext4_set_bits(bh->b_data, block - start, count2); 403 404 err = ext4_handle_dirty_metadata(handle, NULL, bh); 405 if (unlikely(err)) 406 return err; 407 brelse(bh); 408 } 409 410 return 0; 411 } 412 413 /* 414 * Set up the block and inode bitmaps, and the inode table for the new groups. 415 * This doesn't need to be part of the main transaction, since we are only 416 * changing blocks outside the actual filesystem. We still do journaling to 417 * ensure the recovery is correct in case of a failure just after resize. 418 * If any part of this fails, we simply abort the resize. 419 * 420 * setup_new_flex_group_blocks handles a flex group as follow: 421 * 1. copy super block and GDT, and initialize group tables if necessary. 422 * In this step, we only set bits in blocks bitmaps for blocks taken by 423 * super block and GDT. 424 * 2. allocate group tables in block bitmaps, that is, set bits in block 425 * bitmap for blocks taken by group tables. 426 */ 427 static int setup_new_flex_group_blocks(struct super_block *sb, 428 struct ext4_new_flex_group_data *flex_gd) 429 { 430 int group_table_count[] = {1, 1, EXT4_SB(sb)->s_itb_per_group}; 431 ext4_fsblk_t start; 432 ext4_fsblk_t block; 433 struct ext4_sb_info *sbi = EXT4_SB(sb); 434 struct ext4_super_block *es = sbi->s_es; 435 struct ext4_new_group_data *group_data = flex_gd->groups; 436 __u16 *bg_flags = flex_gd->bg_flags; 437 handle_t *handle; 438 ext4_group_t group, count; 439 struct buffer_head *bh = NULL; 440 int reserved_gdb, i, j, err = 0, err2; 441 442 BUG_ON(!flex_gd->count || !group_data || 443 group_data[0].group != sbi->s_groups_count); 444 445 reserved_gdb = le16_to_cpu(es->s_reserved_gdt_blocks); 446 447 /* This transaction may be extended/restarted along the way */ 448 handle = ext4_journal_start_sb(sb, EXT4_MAX_TRANS_DATA); 449 if (IS_ERR(handle)) 450 return PTR_ERR(handle); 451 452 group = group_data[0].group; 453 for (i = 0; i < flex_gd->count; i++, group++) { 454 unsigned long gdblocks; 455 456 gdblocks = ext4_bg_num_gdb(sb, group); 457 start = ext4_group_first_block_no(sb, group); 458 459 if (!ext4_bg_has_super(sb, group)) 460 goto handle_itb; 461 462 /* Copy all of the GDT blocks into the backup in this group */ 463 for (j = 0, block = start + 1; j < gdblocks; j++, block++) { 464 struct buffer_head *gdb; 465 466 ext4_debug("update backup group %#04llx\n", block); 467 err = extend_or_restart_transaction(handle, 1); 468 if (err) 469 goto out; 470 471 gdb = sb_getblk(sb, block); 472 if (!gdb) { 473 err = -EIO; 474 goto out; 475 } 476 477 err = ext4_journal_get_write_access(handle, gdb); 478 if (err) { 479 brelse(gdb); 480 goto out; 481 } 482 memcpy(gdb->b_data, sbi->s_group_desc[j]->b_data, 483 gdb->b_size); 484 set_buffer_uptodate(gdb); 485 486 err = ext4_handle_dirty_metadata(handle, NULL, gdb); 487 if (unlikely(err)) { 488 brelse(gdb); 489 goto out; 490 } 491 brelse(gdb); 492 } 493 494 /* Zero out all of the reserved backup group descriptor 495 * table blocks 496 */ 497 if (ext4_bg_has_super(sb, group)) { 498 err = sb_issue_zeroout(sb, gdblocks + start + 1, 499 reserved_gdb, GFP_NOFS); 500 if (err) 501 goto out; 502 } 503 504 handle_itb: 505 /* Initialize group tables of the grop @group */ 506 if (!(bg_flags[i] & EXT4_BG_INODE_ZEROED)) 507 goto handle_bb; 508 509 /* Zero out all of the inode table blocks */ 510 block = group_data[i].inode_table; 511 ext4_debug("clear inode table blocks %#04llx -> %#04lx\n", 512 block, sbi->s_itb_per_group); 513 err = sb_issue_zeroout(sb, block, sbi->s_itb_per_group, 514 GFP_NOFS); 515 if (err) 516 goto out; 517 518 handle_bb: 519 if (bg_flags[i] & EXT4_BG_BLOCK_UNINIT) 520 goto handle_ib; 521 522 /* Initialize block bitmap of the @group */ 523 block = group_data[i].block_bitmap; 524 err = extend_or_restart_transaction(handle, 1); 525 if (err) 526 goto out; 527 528 bh = bclean(handle, sb, block); 529 if (IS_ERR(bh)) { 530 err = PTR_ERR(bh); 531 goto out; 532 } 533 if (ext4_bg_has_super(sb, group)) { 534 ext4_debug("mark backup superblock %#04llx (+0)\n", 535 start); 536 ext4_set_bits(bh->b_data, 0, gdblocks + reserved_gdb + 537 1); 538 } 539 ext4_mark_bitmap_end(group_data[i].blocks_count, 540 sb->s_blocksize * 8, bh->b_data); 541 err = ext4_handle_dirty_metadata(handle, NULL, bh); 542 if (err) 543 goto out; 544 brelse(bh); 545 546 handle_ib: 547 if (bg_flags[i] & EXT4_BG_INODE_UNINIT) 548 continue; 549 550 /* Initialize inode bitmap of the @group */ 551 block = group_data[i].inode_bitmap; 552 err = extend_or_restart_transaction(handle, 1); 553 if (err) 554 goto out; 555 /* Mark unused entries in inode bitmap used */ 556 bh = bclean(handle, sb, block); 557 if (IS_ERR(bh)) { 558 err = PTR_ERR(bh); 559 goto out; 560 } 561 562 ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb), 563 sb->s_blocksize * 8, bh->b_data); 564 err = ext4_handle_dirty_metadata(handle, NULL, bh); 565 if (err) 566 goto out; 567 brelse(bh); 568 } 569 bh = NULL; 570 571 /* Mark group tables in block bitmap */ 572 for (j = 0; j < GROUP_TABLE_COUNT; j++) { 573 count = group_table_count[j]; 574 start = (&group_data[0].block_bitmap)[j]; 575 block = start; 576 for (i = 1; i < flex_gd->count; i++) { 577 block += group_table_count[j]; 578 if (block == (&group_data[i].block_bitmap)[j]) { 579 count += group_table_count[j]; 580 continue; 581 } 582 err = set_flexbg_block_bitmap(sb, handle, 583 flex_gd, start, count); 584 if (err) 585 goto out; 586 count = group_table_count[j]; 587 start = group_data[i].block_bitmap; 588 block = start; 589 } 590 591 if (count) { 592 err = set_flexbg_block_bitmap(sb, handle, 593 flex_gd, start, count); 594 if (err) 595 goto out; 596 } 597 } 598 599 out: 600 brelse(bh); 601 err2 = ext4_journal_stop(handle); 602 if (err2 && !err) 603 err = err2; 604 605 return err; 606 } 607 608 /* 609 * Iterate through the groups which hold BACKUP superblock/GDT copies in an 610 * ext4 filesystem. The counters should be initialized to 1, 5, and 7 before 611 * calling this for the first time. In a sparse filesystem it will be the 612 * sequence of powers of 3, 5, and 7: 1, 3, 5, 7, 9, 25, 27, 49, 81, ... 613 * For a non-sparse filesystem it will be every group: 1, 2, 3, 4, ... 614 */ 615 static unsigned ext4_list_backups(struct super_block *sb, unsigned *three, 616 unsigned *five, unsigned *seven) 617 { 618 unsigned *min = three; 619 int mult = 3; 620 unsigned ret; 621 622 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, 623 EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER)) { 624 ret = *min; 625 *min += 1; 626 return ret; 627 } 628 629 if (*five < *min) { 630 min = five; 631 mult = 5; 632 } 633 if (*seven < *min) { 634 min = seven; 635 mult = 7; 636 } 637 638 ret = *min; 639 *min *= mult; 640 641 return ret; 642 } 643 644 /* 645 * Check that all of the backup GDT blocks are held in the primary GDT block. 646 * It is assumed that they are stored in group order. Returns the number of 647 * groups in current filesystem that have BACKUPS, or -ve error code. 648 */ 649 static int verify_reserved_gdb(struct super_block *sb, 650 ext4_group_t end, 651 struct buffer_head *primary) 652 { 653 const ext4_fsblk_t blk = primary->b_blocknr; 654 unsigned three = 1; 655 unsigned five = 5; 656 unsigned seven = 7; 657 unsigned grp; 658 __le32 *p = (__le32 *)primary->b_data; 659 int gdbackups = 0; 660 661 while ((grp = ext4_list_backups(sb, &three, &five, &seven)) < end) { 662 if (le32_to_cpu(*p++) != 663 grp * EXT4_BLOCKS_PER_GROUP(sb) + blk){ 664 ext4_warning(sb, "reserved GDT %llu" 665 " missing grp %d (%llu)", 666 blk, grp, 667 grp * 668 (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) + 669 blk); 670 return -EINVAL; 671 } 672 if (++gdbackups > EXT4_ADDR_PER_BLOCK(sb)) 673 return -EFBIG; 674 } 675 676 return gdbackups; 677 } 678 679 /* 680 * Called when we need to bring a reserved group descriptor table block into 681 * use from the resize inode. The primary copy of the new GDT block currently 682 * is an indirect block (under the double indirect block in the resize inode). 683 * The new backup GDT blocks will be stored as leaf blocks in this indirect 684 * block, in group order. Even though we know all the block numbers we need, 685 * we check to ensure that the resize inode has actually reserved these blocks. 686 * 687 * Don't need to update the block bitmaps because the blocks are still in use. 688 * 689 * We get all of the error cases out of the way, so that we are sure to not 690 * fail once we start modifying the data on disk, because JBD has no rollback. 691 */ 692 static int add_new_gdb(handle_t *handle, struct inode *inode, 693 ext4_group_t group) 694 { 695 struct super_block *sb = inode->i_sb; 696 struct ext4_super_block *es = EXT4_SB(sb)->s_es; 697 unsigned long gdb_num = group / EXT4_DESC_PER_BLOCK(sb); 698 ext4_fsblk_t gdblock = EXT4_SB(sb)->s_sbh->b_blocknr + 1 + gdb_num; 699 struct buffer_head **o_group_desc, **n_group_desc; 700 struct buffer_head *dind; 701 struct buffer_head *gdb_bh; 702 int gdbackups; 703 struct ext4_iloc iloc; 704 __le32 *data; 705 int err; 706 707 if (test_opt(sb, DEBUG)) 708 printk(KERN_DEBUG 709 "EXT4-fs: ext4_add_new_gdb: adding group block %lu\n", 710 gdb_num); 711 712 /* 713 * If we are not using the primary superblock/GDT copy don't resize, 714 * because the user tools have no way of handling this. Probably a 715 * bad time to do it anyways. 716 */ 717 if (EXT4_SB(sb)->s_sbh->b_blocknr != 718 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block)) { 719 ext4_warning(sb, "won't resize using backup superblock at %llu", 720 (unsigned long long)EXT4_SB(sb)->s_sbh->b_blocknr); 721 return -EPERM; 722 } 723 724 gdb_bh = sb_bread(sb, gdblock); 725 if (!gdb_bh) 726 return -EIO; 727 728 gdbackups = verify_reserved_gdb(sb, group, gdb_bh); 729 if (gdbackups < 0) { 730 err = gdbackups; 731 goto exit_bh; 732 } 733 734 data = EXT4_I(inode)->i_data + EXT4_DIND_BLOCK; 735 dind = sb_bread(sb, le32_to_cpu(*data)); 736 if (!dind) { 737 err = -EIO; 738 goto exit_bh; 739 } 740 741 data = (__le32 *)dind->b_data; 742 if (le32_to_cpu(data[gdb_num % EXT4_ADDR_PER_BLOCK(sb)]) != gdblock) { 743 ext4_warning(sb, "new group %u GDT block %llu not reserved", 744 group, gdblock); 745 err = -EINVAL; 746 goto exit_dind; 747 } 748 749 err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh); 750 if (unlikely(err)) 751 goto exit_dind; 752 753 err = ext4_journal_get_write_access(handle, gdb_bh); 754 if (unlikely(err)) 755 goto exit_sbh; 756 757 err = ext4_journal_get_write_access(handle, dind); 758 if (unlikely(err)) 759 ext4_std_error(sb, err); 760 761 /* ext4_reserve_inode_write() gets a reference on the iloc */ 762 err = ext4_reserve_inode_write(handle, inode, &iloc); 763 if (unlikely(err)) 764 goto exit_dindj; 765 766 n_group_desc = ext4_kvmalloc((gdb_num + 1) * 767 sizeof(struct buffer_head *), 768 GFP_NOFS); 769 if (!n_group_desc) { 770 err = -ENOMEM; 771 ext4_warning(sb, "not enough memory for %lu groups", 772 gdb_num + 1); 773 goto exit_inode; 774 } 775 776 /* 777 * Finally, we have all of the possible failures behind us... 778 * 779 * Remove new GDT block from inode double-indirect block and clear out 780 * the new GDT block for use (which also "frees" the backup GDT blocks 781 * from the reserved inode). We don't need to change the bitmaps for 782 * these blocks, because they are marked as in-use from being in the 783 * reserved inode, and will become GDT blocks (primary and backup). 784 */ 785 data[gdb_num % EXT4_ADDR_PER_BLOCK(sb)] = 0; 786 err = ext4_handle_dirty_metadata(handle, NULL, dind); 787 if (unlikely(err)) { 788 ext4_std_error(sb, err); 789 goto exit_inode; 790 } 791 inode->i_blocks -= (gdbackups + 1) * sb->s_blocksize >> 9; 792 ext4_mark_iloc_dirty(handle, inode, &iloc); 793 memset(gdb_bh->b_data, 0, sb->s_blocksize); 794 err = ext4_handle_dirty_metadata(handle, NULL, gdb_bh); 795 if (unlikely(err)) { 796 ext4_std_error(sb, err); 797 goto exit_inode; 798 } 799 brelse(dind); 800 801 o_group_desc = EXT4_SB(sb)->s_group_desc; 802 memcpy(n_group_desc, o_group_desc, 803 EXT4_SB(sb)->s_gdb_count * sizeof(struct buffer_head *)); 804 n_group_desc[gdb_num] = gdb_bh; 805 EXT4_SB(sb)->s_group_desc = n_group_desc; 806 EXT4_SB(sb)->s_gdb_count++; 807 ext4_kvfree(o_group_desc); 808 809 le16_add_cpu(&es->s_reserved_gdt_blocks, -1); 810 err = ext4_handle_dirty_super(handle, sb); 811 if (err) 812 ext4_std_error(sb, err); 813 814 return err; 815 816 exit_inode: 817 ext4_kvfree(n_group_desc); 818 /* ext4_handle_release_buffer(handle, iloc.bh); */ 819 brelse(iloc.bh); 820 exit_dindj: 821 /* ext4_handle_release_buffer(handle, dind); */ 822 exit_sbh: 823 /* ext4_handle_release_buffer(handle, EXT4_SB(sb)->s_sbh); */ 824 exit_dind: 825 brelse(dind); 826 exit_bh: 827 brelse(gdb_bh); 828 829 ext4_debug("leaving with error %d\n", err); 830 return err; 831 } 832 833 /* 834 * Called when we are adding a new group which has a backup copy of each of 835 * the GDT blocks (i.e. sparse group) and there are reserved GDT blocks. 836 * We need to add these reserved backup GDT blocks to the resize inode, so 837 * that they are kept for future resizing and not allocated to files. 838 * 839 * Each reserved backup GDT block will go into a different indirect block. 840 * The indirect blocks are actually the primary reserved GDT blocks, 841 * so we know in advance what their block numbers are. We only get the 842 * double-indirect block to verify it is pointing to the primary reserved 843 * GDT blocks so we don't overwrite a data block by accident. The reserved 844 * backup GDT blocks are stored in their reserved primary GDT block. 845 */ 846 static int reserve_backup_gdb(handle_t *handle, struct inode *inode, 847 ext4_group_t group) 848 { 849 struct super_block *sb = inode->i_sb; 850 int reserved_gdb =le16_to_cpu(EXT4_SB(sb)->s_es->s_reserved_gdt_blocks); 851 struct buffer_head **primary; 852 struct buffer_head *dind; 853 struct ext4_iloc iloc; 854 ext4_fsblk_t blk; 855 __le32 *data, *end; 856 int gdbackups = 0; 857 int res, i; 858 int err; 859 860 primary = kmalloc(reserved_gdb * sizeof(*primary), GFP_NOFS); 861 if (!primary) 862 return -ENOMEM; 863 864 data = EXT4_I(inode)->i_data + EXT4_DIND_BLOCK; 865 dind = sb_bread(sb, le32_to_cpu(*data)); 866 if (!dind) { 867 err = -EIO; 868 goto exit_free; 869 } 870 871 blk = EXT4_SB(sb)->s_sbh->b_blocknr + 1 + EXT4_SB(sb)->s_gdb_count; 872 data = (__le32 *)dind->b_data + (EXT4_SB(sb)->s_gdb_count % 873 EXT4_ADDR_PER_BLOCK(sb)); 874 end = (__le32 *)dind->b_data + EXT4_ADDR_PER_BLOCK(sb); 875 876 /* Get each reserved primary GDT block and verify it holds backups */ 877 for (res = 0; res < reserved_gdb; res++, blk++) { 878 if (le32_to_cpu(*data) != blk) { 879 ext4_warning(sb, "reserved block %llu" 880 " not at offset %ld", 881 blk, 882 (long)(data - (__le32 *)dind->b_data)); 883 err = -EINVAL; 884 goto exit_bh; 885 } 886 primary[res] = sb_bread(sb, blk); 887 if (!primary[res]) { 888 err = -EIO; 889 goto exit_bh; 890 } 891 gdbackups = verify_reserved_gdb(sb, group, primary[res]); 892 if (gdbackups < 0) { 893 brelse(primary[res]); 894 err = gdbackups; 895 goto exit_bh; 896 } 897 if (++data >= end) 898 data = (__le32 *)dind->b_data; 899 } 900 901 for (i = 0; i < reserved_gdb; i++) { 902 if ((err = ext4_journal_get_write_access(handle, primary[i]))) { 903 /* 904 int j; 905 for (j = 0; j < i; j++) 906 ext4_handle_release_buffer(handle, primary[j]); 907 */ 908 goto exit_bh; 909 } 910 } 911 912 if ((err = ext4_reserve_inode_write(handle, inode, &iloc))) 913 goto exit_bh; 914 915 /* 916 * Finally we can add each of the reserved backup GDT blocks from 917 * the new group to its reserved primary GDT block. 918 */ 919 blk = group * EXT4_BLOCKS_PER_GROUP(sb); 920 for (i = 0; i < reserved_gdb; i++) { 921 int err2; 922 data = (__le32 *)primary[i]->b_data; 923 /* printk("reserving backup %lu[%u] = %lu\n", 924 primary[i]->b_blocknr, gdbackups, 925 blk + primary[i]->b_blocknr); */ 926 data[gdbackups] = cpu_to_le32(blk + primary[i]->b_blocknr); 927 err2 = ext4_handle_dirty_metadata(handle, NULL, primary[i]); 928 if (!err) 929 err = err2; 930 } 931 inode->i_blocks += reserved_gdb * sb->s_blocksize >> 9; 932 ext4_mark_iloc_dirty(handle, inode, &iloc); 933 934 exit_bh: 935 while (--res >= 0) 936 brelse(primary[res]); 937 brelse(dind); 938 939 exit_free: 940 kfree(primary); 941 942 return err; 943 } 944 945 /* 946 * Update the backup copies of the ext4 metadata. These don't need to be part 947 * of the main resize transaction, because e2fsck will re-write them if there 948 * is a problem (basically only OOM will cause a problem). However, we 949 * _should_ update the backups if possible, in case the primary gets trashed 950 * for some reason and we need to run e2fsck from a backup superblock. The 951 * important part is that the new block and inode counts are in the backup 952 * superblocks, and the location of the new group metadata in the GDT backups. 953 * 954 * We do not need take the s_resize_lock for this, because these 955 * blocks are not otherwise touched by the filesystem code when it is 956 * mounted. We don't need to worry about last changing from 957 * sbi->s_groups_count, because the worst that can happen is that we 958 * do not copy the full number of backups at this time. The resize 959 * which changed s_groups_count will backup again. 960 */ 961 static void update_backups(struct super_block *sb, 962 int blk_off, char *data, int size) 963 { 964 struct ext4_sb_info *sbi = EXT4_SB(sb); 965 const ext4_group_t last = sbi->s_groups_count; 966 const int bpg = EXT4_BLOCKS_PER_GROUP(sb); 967 unsigned three = 1; 968 unsigned five = 5; 969 unsigned seven = 7; 970 ext4_group_t group; 971 int rest = sb->s_blocksize - size; 972 handle_t *handle; 973 int err = 0, err2; 974 975 handle = ext4_journal_start_sb(sb, EXT4_MAX_TRANS_DATA); 976 if (IS_ERR(handle)) { 977 group = 1; 978 err = PTR_ERR(handle); 979 goto exit_err; 980 } 981 982 ext4_superblock_csum_set(sb, (struct ext4_super_block *)data); 983 984 while ((group = ext4_list_backups(sb, &three, &five, &seven)) < last) { 985 struct buffer_head *bh; 986 987 /* Out of journal space, and can't get more - abort - so sad */ 988 if (ext4_handle_valid(handle) && 989 handle->h_buffer_credits == 0 && 990 ext4_journal_extend(handle, EXT4_MAX_TRANS_DATA) && 991 (err = ext4_journal_restart(handle, EXT4_MAX_TRANS_DATA))) 992 break; 993 994 bh = sb_getblk(sb, group * bpg + blk_off); 995 if (!bh) { 996 err = -EIO; 997 break; 998 } 999 ext4_debug("update metadata backup %#04lx\n", 1000 (unsigned long)bh->b_blocknr); 1001 if ((err = ext4_journal_get_write_access(handle, bh))) 1002 break; 1003 lock_buffer(bh); 1004 memcpy(bh->b_data, data, size); 1005 if (rest) 1006 memset(bh->b_data + size, 0, rest); 1007 set_buffer_uptodate(bh); 1008 unlock_buffer(bh); 1009 err = ext4_handle_dirty_metadata(handle, NULL, bh); 1010 if (unlikely(err)) 1011 ext4_std_error(sb, err); 1012 brelse(bh); 1013 } 1014 if ((err2 = ext4_journal_stop(handle)) && !err) 1015 err = err2; 1016 1017 /* 1018 * Ugh! Need to have e2fsck write the backup copies. It is too 1019 * late to revert the resize, we shouldn't fail just because of 1020 * the backup copies (they are only needed in case of corruption). 1021 * 1022 * However, if we got here we have a journal problem too, so we 1023 * can't really start a transaction to mark the superblock. 1024 * Chicken out and just set the flag on the hope it will be written 1025 * to disk, and if not - we will simply wait until next fsck. 1026 */ 1027 exit_err: 1028 if (err) { 1029 ext4_warning(sb, "can't update backup for group %u (err %d), " 1030 "forcing fsck on next reboot", group, err); 1031 sbi->s_mount_state &= ~EXT4_VALID_FS; 1032 sbi->s_es->s_state &= cpu_to_le16(~EXT4_VALID_FS); 1033 mark_buffer_dirty(sbi->s_sbh); 1034 } 1035 } 1036 1037 /* 1038 * ext4_add_new_descs() adds @count group descriptor of groups 1039 * starting at @group 1040 * 1041 * @handle: journal handle 1042 * @sb: super block 1043 * @group: the group no. of the first group desc to be added 1044 * @resize_inode: the resize inode 1045 * @count: number of group descriptors to be added 1046 */ 1047 static int ext4_add_new_descs(handle_t *handle, struct super_block *sb, 1048 ext4_group_t group, struct inode *resize_inode, 1049 ext4_group_t count) 1050 { 1051 struct ext4_sb_info *sbi = EXT4_SB(sb); 1052 struct ext4_super_block *es = sbi->s_es; 1053 struct buffer_head *gdb_bh; 1054 int i, gdb_off, gdb_num, err = 0; 1055 1056 for (i = 0; i < count; i++, group++) { 1057 int reserved_gdb = ext4_bg_has_super(sb, group) ? 1058 le16_to_cpu(es->s_reserved_gdt_blocks) : 0; 1059 1060 gdb_off = group % EXT4_DESC_PER_BLOCK(sb); 1061 gdb_num = group / EXT4_DESC_PER_BLOCK(sb); 1062 1063 /* 1064 * We will only either add reserved group blocks to a backup group 1065 * or remove reserved blocks for the first group in a new group block. 1066 * Doing both would be mean more complex code, and sane people don't 1067 * use non-sparse filesystems anymore. This is already checked above. 1068 */ 1069 if (gdb_off) { 1070 gdb_bh = sbi->s_group_desc[gdb_num]; 1071 err = ext4_journal_get_write_access(handle, gdb_bh); 1072 1073 if (!err && reserved_gdb && ext4_bg_num_gdb(sb, group)) 1074 err = reserve_backup_gdb(handle, resize_inode, group); 1075 } else 1076 err = add_new_gdb(handle, resize_inode, group); 1077 if (err) 1078 break; 1079 } 1080 return err; 1081 } 1082 1083 static struct buffer_head *ext4_get_bitmap(struct super_block *sb, __u64 block) 1084 { 1085 struct buffer_head *bh = sb_getblk(sb, block); 1086 if (!bh) 1087 return NULL; 1088 1089 if (bitmap_uptodate(bh)) 1090 return bh; 1091 1092 lock_buffer(bh); 1093 if (bh_submit_read(bh) < 0) { 1094 unlock_buffer(bh); 1095 brelse(bh); 1096 return NULL; 1097 } 1098 unlock_buffer(bh); 1099 1100 return bh; 1101 } 1102 1103 static int ext4_set_bitmap_checksums(struct super_block *sb, 1104 ext4_group_t group, 1105 struct ext4_group_desc *gdp, 1106 struct ext4_new_group_data *group_data) 1107 { 1108 struct buffer_head *bh; 1109 1110 if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, 1111 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) 1112 return 0; 1113 1114 bh = ext4_get_bitmap(sb, group_data->inode_bitmap); 1115 if (!bh) 1116 return -EIO; 1117 ext4_inode_bitmap_csum_set(sb, group, gdp, bh, 1118 EXT4_INODES_PER_GROUP(sb) / 8); 1119 brelse(bh); 1120 1121 bh = ext4_get_bitmap(sb, group_data->block_bitmap); 1122 if (!bh) 1123 return -EIO; 1124 ext4_block_bitmap_csum_set(sb, group, gdp, bh, 1125 EXT4_BLOCKS_PER_GROUP(sb) / 8); 1126 brelse(bh); 1127 1128 return 0; 1129 } 1130 1131 /* 1132 * ext4_setup_new_descs() will set up the group descriptor descriptors of a flex bg 1133 */ 1134 static int ext4_setup_new_descs(handle_t *handle, struct super_block *sb, 1135 struct ext4_new_flex_group_data *flex_gd) 1136 { 1137 struct ext4_new_group_data *group_data = flex_gd->groups; 1138 struct ext4_group_desc *gdp; 1139 struct ext4_sb_info *sbi = EXT4_SB(sb); 1140 struct buffer_head *gdb_bh; 1141 ext4_group_t group; 1142 __u16 *bg_flags = flex_gd->bg_flags; 1143 int i, gdb_off, gdb_num, err = 0; 1144 1145 1146 for (i = 0; i < flex_gd->count; i++, group_data++, bg_flags++) { 1147 group = group_data->group; 1148 1149 gdb_off = group % EXT4_DESC_PER_BLOCK(sb); 1150 gdb_num = group / EXT4_DESC_PER_BLOCK(sb); 1151 1152 /* 1153 * get_write_access() has been called on gdb_bh by ext4_add_new_desc(). 1154 */ 1155 gdb_bh = sbi->s_group_desc[gdb_num]; 1156 /* Update group descriptor block for new group */ 1157 gdp = (struct ext4_group_desc *)(gdb_bh->b_data + 1158 gdb_off * EXT4_DESC_SIZE(sb)); 1159 1160 memset(gdp, 0, EXT4_DESC_SIZE(sb)); 1161 ext4_block_bitmap_set(sb, gdp, group_data->block_bitmap); 1162 ext4_inode_bitmap_set(sb, gdp, group_data->inode_bitmap); 1163 err = ext4_set_bitmap_checksums(sb, group, gdp, group_data); 1164 if (err) { 1165 ext4_std_error(sb, err); 1166 break; 1167 } 1168 1169 ext4_inode_table_set(sb, gdp, group_data->inode_table); 1170 ext4_free_group_clusters_set(sb, gdp, 1171 EXT4_B2C(sbi, group_data->free_blocks_count)); 1172 ext4_free_inodes_set(sb, gdp, EXT4_INODES_PER_GROUP(sb)); 1173 gdp->bg_flags = cpu_to_le16(*bg_flags); 1174 ext4_group_desc_csum_set(sb, group, gdp); 1175 1176 err = ext4_handle_dirty_metadata(handle, NULL, gdb_bh); 1177 if (unlikely(err)) { 1178 ext4_std_error(sb, err); 1179 break; 1180 } 1181 1182 /* 1183 * We can allocate memory for mb_alloc based on the new group 1184 * descriptor 1185 */ 1186 err = ext4_mb_add_groupinfo(sb, group, gdp); 1187 if (err) 1188 break; 1189 } 1190 return err; 1191 } 1192 1193 /* 1194 * ext4_update_super() updates the super block so that the newly added 1195 * groups can be seen by the filesystem. 1196 * 1197 * @sb: super block 1198 * @flex_gd: new added groups 1199 */ 1200 static void ext4_update_super(struct super_block *sb, 1201 struct ext4_new_flex_group_data *flex_gd) 1202 { 1203 ext4_fsblk_t blocks_count = 0; 1204 ext4_fsblk_t free_blocks = 0; 1205 ext4_fsblk_t reserved_blocks = 0; 1206 struct ext4_new_group_data *group_data = flex_gd->groups; 1207 struct ext4_sb_info *sbi = EXT4_SB(sb); 1208 struct ext4_super_block *es = sbi->s_es; 1209 int i; 1210 1211 BUG_ON(flex_gd->count == 0 || group_data == NULL); 1212 /* 1213 * Make the new blocks and inodes valid next. We do this before 1214 * increasing the group count so that once the group is enabled, 1215 * all of its blocks and inodes are already valid. 1216 * 1217 * We always allocate group-by-group, then block-by-block or 1218 * inode-by-inode within a group, so enabling these 1219 * blocks/inodes before the group is live won't actually let us 1220 * allocate the new space yet. 1221 */ 1222 for (i = 0; i < flex_gd->count; i++) { 1223 blocks_count += group_data[i].blocks_count; 1224 free_blocks += group_data[i].free_blocks_count; 1225 } 1226 1227 reserved_blocks = ext4_r_blocks_count(es) * 100; 1228 do_div(reserved_blocks, ext4_blocks_count(es)); 1229 reserved_blocks *= blocks_count; 1230 do_div(reserved_blocks, 100); 1231 1232 ext4_blocks_count_set(es, ext4_blocks_count(es) + blocks_count); 1233 ext4_free_blocks_count_set(es, ext4_free_blocks_count(es) + free_blocks); 1234 le32_add_cpu(&es->s_inodes_count, EXT4_INODES_PER_GROUP(sb) * 1235 flex_gd->count); 1236 le32_add_cpu(&es->s_free_inodes_count, EXT4_INODES_PER_GROUP(sb) * 1237 flex_gd->count); 1238 1239 /* 1240 * We need to protect s_groups_count against other CPUs seeing 1241 * inconsistent state in the superblock. 1242 * 1243 * The precise rules we use are: 1244 * 1245 * * Writers must perform a smp_wmb() after updating all 1246 * dependent data and before modifying the groups count 1247 * 1248 * * Readers must perform an smp_rmb() after reading the groups 1249 * count and before reading any dependent data. 1250 * 1251 * NB. These rules can be relaxed when checking the group count 1252 * while freeing data, as we can only allocate from a block 1253 * group after serialising against the group count, and we can 1254 * only then free after serialising in turn against that 1255 * allocation. 1256 */ 1257 smp_wmb(); 1258 1259 /* Update the global fs size fields */ 1260 sbi->s_groups_count += flex_gd->count; 1261 1262 /* Update the reserved block counts only once the new group is 1263 * active. */ 1264 ext4_r_blocks_count_set(es, ext4_r_blocks_count(es) + 1265 reserved_blocks); 1266 1267 /* Update the free space counts */ 1268 percpu_counter_add(&sbi->s_freeclusters_counter, 1269 EXT4_B2C(sbi, free_blocks)); 1270 percpu_counter_add(&sbi->s_freeinodes_counter, 1271 EXT4_INODES_PER_GROUP(sb) * flex_gd->count); 1272 1273 if (EXT4_HAS_INCOMPAT_FEATURE(sb, 1274 EXT4_FEATURE_INCOMPAT_FLEX_BG) && 1275 sbi->s_log_groups_per_flex) { 1276 ext4_group_t flex_group; 1277 flex_group = ext4_flex_group(sbi, group_data[0].group); 1278 atomic_add(EXT4_B2C(sbi, free_blocks), 1279 &sbi->s_flex_groups[flex_group].free_clusters); 1280 atomic_add(EXT4_INODES_PER_GROUP(sb) * flex_gd->count, 1281 &sbi->s_flex_groups[flex_group].free_inodes); 1282 } 1283 1284 /* 1285 * Update the fs overhead information 1286 */ 1287 ext4_calculate_overhead(sb); 1288 1289 if (test_opt(sb, DEBUG)) 1290 printk(KERN_DEBUG "EXT4-fs: added group %u:" 1291 "%llu blocks(%llu free %llu reserved)\n", flex_gd->count, 1292 blocks_count, free_blocks, reserved_blocks); 1293 } 1294 1295 /* Add a flex group to an fs. Ensure we handle all possible error conditions 1296 * _before_ we start modifying the filesystem, because we cannot abort the 1297 * transaction and not have it write the data to disk. 1298 */ 1299 static int ext4_flex_group_add(struct super_block *sb, 1300 struct inode *resize_inode, 1301 struct ext4_new_flex_group_data *flex_gd) 1302 { 1303 struct ext4_sb_info *sbi = EXT4_SB(sb); 1304 struct ext4_super_block *es = sbi->s_es; 1305 ext4_fsblk_t o_blocks_count; 1306 ext4_grpblk_t last; 1307 ext4_group_t group; 1308 handle_t *handle; 1309 unsigned reserved_gdb; 1310 int err = 0, err2 = 0, credit; 1311 1312 BUG_ON(!flex_gd->count || !flex_gd->groups || !flex_gd->bg_flags); 1313 1314 reserved_gdb = le16_to_cpu(es->s_reserved_gdt_blocks); 1315 o_blocks_count = ext4_blocks_count(es); 1316 ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last); 1317 BUG_ON(last); 1318 1319 err = setup_new_flex_group_blocks(sb, flex_gd); 1320 if (err) 1321 goto exit; 1322 /* 1323 * We will always be modifying at least the superblock and GDT 1324 * block. If we are adding a group past the last current GDT block, 1325 * we will also modify the inode and the dindirect block. If we 1326 * are adding a group with superblock/GDT backups we will also 1327 * modify each of the reserved GDT dindirect blocks. 1328 */ 1329 credit = flex_gd->count * 4 + reserved_gdb; 1330 handle = ext4_journal_start_sb(sb, credit); 1331 if (IS_ERR(handle)) { 1332 err = PTR_ERR(handle); 1333 goto exit; 1334 } 1335 1336 err = ext4_journal_get_write_access(handle, sbi->s_sbh); 1337 if (err) 1338 goto exit_journal; 1339 1340 group = flex_gd->groups[0].group; 1341 BUG_ON(group != EXT4_SB(sb)->s_groups_count); 1342 err = ext4_add_new_descs(handle, sb, group, 1343 resize_inode, flex_gd->count); 1344 if (err) 1345 goto exit_journal; 1346 1347 err = ext4_setup_new_descs(handle, sb, flex_gd); 1348 if (err) 1349 goto exit_journal; 1350 1351 ext4_update_super(sb, flex_gd); 1352 1353 err = ext4_handle_dirty_super(handle, sb); 1354 1355 exit_journal: 1356 err2 = ext4_journal_stop(handle); 1357 if (!err) 1358 err = err2; 1359 1360 if (!err) { 1361 int gdb_num = group / EXT4_DESC_PER_BLOCK(sb); 1362 int gdb_num_end = ((group + flex_gd->count - 1) / 1363 EXT4_DESC_PER_BLOCK(sb)); 1364 1365 update_backups(sb, sbi->s_sbh->b_blocknr, (char *)es, 1366 sizeof(struct ext4_super_block)); 1367 for (; gdb_num <= gdb_num_end; gdb_num++) { 1368 struct buffer_head *gdb_bh; 1369 1370 gdb_bh = sbi->s_group_desc[gdb_num]; 1371 update_backups(sb, gdb_bh->b_blocknr, gdb_bh->b_data, 1372 gdb_bh->b_size); 1373 } 1374 } 1375 exit: 1376 return err; 1377 } 1378 1379 static int ext4_setup_next_flex_gd(struct super_block *sb, 1380 struct ext4_new_flex_group_data *flex_gd, 1381 ext4_fsblk_t n_blocks_count, 1382 unsigned long flexbg_size) 1383 { 1384 struct ext4_super_block *es = EXT4_SB(sb)->s_es; 1385 struct ext4_new_group_data *group_data = flex_gd->groups; 1386 ext4_fsblk_t o_blocks_count; 1387 ext4_group_t n_group; 1388 ext4_group_t group; 1389 ext4_group_t last_group; 1390 ext4_grpblk_t last; 1391 ext4_grpblk_t blocks_per_group; 1392 unsigned long i; 1393 1394 blocks_per_group = EXT4_BLOCKS_PER_GROUP(sb); 1395 1396 o_blocks_count = ext4_blocks_count(es); 1397 1398 if (o_blocks_count == n_blocks_count) 1399 return 0; 1400 1401 ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last); 1402 BUG_ON(last); 1403 ext4_get_group_no_and_offset(sb, n_blocks_count - 1, &n_group, &last); 1404 1405 last_group = group | (flexbg_size - 1); 1406 if (last_group > n_group) 1407 last_group = n_group; 1408 1409 flex_gd->count = last_group - group + 1; 1410 1411 for (i = 0; i < flex_gd->count; i++) { 1412 int overhead; 1413 1414 group_data[i].group = group + i; 1415 group_data[i].blocks_count = blocks_per_group; 1416 overhead = ext4_bg_has_super(sb, group + i) ? 1417 (1 + ext4_bg_num_gdb(sb, group + i) + 1418 le16_to_cpu(es->s_reserved_gdt_blocks)) : 0; 1419 group_data[i].free_blocks_count = blocks_per_group - overhead; 1420 if (ext4_has_group_desc_csum(sb)) 1421 flex_gd->bg_flags[i] = EXT4_BG_BLOCK_UNINIT | 1422 EXT4_BG_INODE_UNINIT; 1423 else 1424 flex_gd->bg_flags[i] = EXT4_BG_INODE_ZEROED; 1425 } 1426 1427 if (last_group == n_group && ext4_has_group_desc_csum(sb)) 1428 /* We need to initialize block bitmap of last group. */ 1429 flex_gd->bg_flags[i - 1] &= ~EXT4_BG_BLOCK_UNINIT; 1430 1431 if ((last_group == n_group) && (last != blocks_per_group - 1)) { 1432 group_data[i - 1].blocks_count = last + 1; 1433 group_data[i - 1].free_blocks_count -= blocks_per_group- 1434 last - 1; 1435 } 1436 1437 return 1; 1438 } 1439 1440 /* Add group descriptor data to an existing or new group descriptor block. 1441 * Ensure we handle all possible error conditions _before_ we start modifying 1442 * the filesystem, because we cannot abort the transaction and not have it 1443 * write the data to disk. 1444 * 1445 * If we are on a GDT block boundary, we need to get the reserved GDT block. 1446 * Otherwise, we may need to add backup GDT blocks for a sparse group. 1447 * 1448 * We only need to hold the superblock lock while we are actually adding 1449 * in the new group's counts to the superblock. Prior to that we have 1450 * not really "added" the group at all. We re-check that we are still 1451 * adding in the last group in case things have changed since verifying. 1452 */ 1453 int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input) 1454 { 1455 struct ext4_new_flex_group_data flex_gd; 1456 struct ext4_sb_info *sbi = EXT4_SB(sb); 1457 struct ext4_super_block *es = sbi->s_es; 1458 int reserved_gdb = ext4_bg_has_super(sb, input->group) ? 1459 le16_to_cpu(es->s_reserved_gdt_blocks) : 0; 1460 struct inode *inode = NULL; 1461 int gdb_off, gdb_num; 1462 int err; 1463 __u16 bg_flags = 0; 1464 1465 gdb_num = input->group / EXT4_DESC_PER_BLOCK(sb); 1466 gdb_off = input->group % EXT4_DESC_PER_BLOCK(sb); 1467 1468 if (gdb_off == 0 && !EXT4_HAS_RO_COMPAT_FEATURE(sb, 1469 EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER)) { 1470 ext4_warning(sb, "Can't resize non-sparse filesystem further"); 1471 return -EPERM; 1472 } 1473 1474 if (ext4_blocks_count(es) + input->blocks_count < 1475 ext4_blocks_count(es)) { 1476 ext4_warning(sb, "blocks_count overflow"); 1477 return -EINVAL; 1478 } 1479 1480 if (le32_to_cpu(es->s_inodes_count) + EXT4_INODES_PER_GROUP(sb) < 1481 le32_to_cpu(es->s_inodes_count)) { 1482 ext4_warning(sb, "inodes_count overflow"); 1483 return -EINVAL; 1484 } 1485 1486 if (reserved_gdb || gdb_off == 0) { 1487 if (!EXT4_HAS_COMPAT_FEATURE(sb, 1488 EXT4_FEATURE_COMPAT_RESIZE_INODE) 1489 || !le16_to_cpu(es->s_reserved_gdt_blocks)) { 1490 ext4_warning(sb, 1491 "No reserved GDT blocks, can't resize"); 1492 return -EPERM; 1493 } 1494 inode = ext4_iget(sb, EXT4_RESIZE_INO); 1495 if (IS_ERR(inode)) { 1496 ext4_warning(sb, "Error opening resize inode"); 1497 return PTR_ERR(inode); 1498 } 1499 } 1500 1501 1502 err = verify_group_input(sb, input); 1503 if (err) 1504 goto out; 1505 1506 err = ext4_alloc_flex_bg_array(sb, input->group + 1); 1507 if (err) 1508 return err; 1509 1510 flex_gd.count = 1; 1511 flex_gd.groups = input; 1512 flex_gd.bg_flags = &bg_flags; 1513 err = ext4_flex_group_add(sb, inode, &flex_gd); 1514 out: 1515 iput(inode); 1516 return err; 1517 } /* ext4_group_add */ 1518 1519 /* 1520 * extend a group without checking assuming that checking has been done. 1521 */ 1522 static int ext4_group_extend_no_check(struct super_block *sb, 1523 ext4_fsblk_t o_blocks_count, ext4_grpblk_t add) 1524 { 1525 struct ext4_super_block *es = EXT4_SB(sb)->s_es; 1526 handle_t *handle; 1527 int err = 0, err2; 1528 1529 /* We will update the superblock, one block bitmap, and 1530 * one group descriptor via ext4_group_add_blocks(). 1531 */ 1532 handle = ext4_journal_start_sb(sb, 3); 1533 if (IS_ERR(handle)) { 1534 err = PTR_ERR(handle); 1535 ext4_warning(sb, "error %d on journal start", err); 1536 return err; 1537 } 1538 1539 err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh); 1540 if (err) { 1541 ext4_warning(sb, "error %d on journal write access", err); 1542 goto errout; 1543 } 1544 1545 ext4_blocks_count_set(es, o_blocks_count + add); 1546 ext4_free_blocks_count_set(es, ext4_free_blocks_count(es) + add); 1547 ext4_debug("freeing blocks %llu through %llu\n", o_blocks_count, 1548 o_blocks_count + add); 1549 /* We add the blocks to the bitmap and set the group need init bit */ 1550 err = ext4_group_add_blocks(handle, sb, o_blocks_count, add); 1551 if (err) 1552 goto errout; 1553 ext4_handle_dirty_super(handle, sb); 1554 ext4_debug("freed blocks %llu through %llu\n", o_blocks_count, 1555 o_blocks_count + add); 1556 errout: 1557 err2 = ext4_journal_stop(handle); 1558 if (err2 && !err) 1559 err = err2; 1560 1561 if (!err) { 1562 if (test_opt(sb, DEBUG)) 1563 printk(KERN_DEBUG "EXT4-fs: extended group to %llu " 1564 "blocks\n", ext4_blocks_count(es)); 1565 update_backups(sb, EXT4_SB(sb)->s_sbh->b_blocknr, (char *)es, 1566 sizeof(struct ext4_super_block)); 1567 } 1568 return err; 1569 } 1570 1571 /* 1572 * Extend the filesystem to the new number of blocks specified. This entry 1573 * point is only used to extend the current filesystem to the end of the last 1574 * existing group. It can be accessed via ioctl, or by "remount,resize=<size>" 1575 * for emergencies (because it has no dependencies on reserved blocks). 1576 * 1577 * If we _really_ wanted, we could use default values to call ext4_group_add() 1578 * allow the "remount" trick to work for arbitrary resizing, assuming enough 1579 * GDT blocks are reserved to grow to the desired size. 1580 */ 1581 int ext4_group_extend(struct super_block *sb, struct ext4_super_block *es, 1582 ext4_fsblk_t n_blocks_count) 1583 { 1584 ext4_fsblk_t o_blocks_count; 1585 ext4_grpblk_t last; 1586 ext4_grpblk_t add; 1587 struct buffer_head *bh; 1588 int err; 1589 ext4_group_t group; 1590 1591 o_blocks_count = ext4_blocks_count(es); 1592 1593 if (test_opt(sb, DEBUG)) 1594 ext4_msg(sb, KERN_DEBUG, 1595 "extending last group from %llu to %llu blocks", 1596 o_blocks_count, n_blocks_count); 1597 1598 if (n_blocks_count == 0 || n_blocks_count == o_blocks_count) 1599 return 0; 1600 1601 if (n_blocks_count > (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) { 1602 ext4_msg(sb, KERN_ERR, 1603 "filesystem too large to resize to %llu blocks safely", 1604 n_blocks_count); 1605 if (sizeof(sector_t) < 8) 1606 ext4_warning(sb, "CONFIG_LBDAF not enabled"); 1607 return -EINVAL; 1608 } 1609 1610 if (n_blocks_count < o_blocks_count) { 1611 ext4_warning(sb, "can't shrink FS - resize aborted"); 1612 return -EINVAL; 1613 } 1614 1615 /* Handle the remaining blocks in the last group only. */ 1616 ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last); 1617 1618 if (last == 0) { 1619 ext4_warning(sb, "need to use ext2online to resize further"); 1620 return -EPERM; 1621 } 1622 1623 add = EXT4_BLOCKS_PER_GROUP(sb) - last; 1624 1625 if (o_blocks_count + add < o_blocks_count) { 1626 ext4_warning(sb, "blocks_count overflow"); 1627 return -EINVAL; 1628 } 1629 1630 if (o_blocks_count + add > n_blocks_count) 1631 add = n_blocks_count - o_blocks_count; 1632 1633 if (o_blocks_count + add < n_blocks_count) 1634 ext4_warning(sb, "will only finish group (%llu blocks, %u new)", 1635 o_blocks_count + add, add); 1636 1637 /* See if the device is actually as big as what was requested */ 1638 bh = sb_bread(sb, o_blocks_count + add - 1); 1639 if (!bh) { 1640 ext4_warning(sb, "can't read last block, resize aborted"); 1641 return -ENOSPC; 1642 } 1643 brelse(bh); 1644 1645 err = ext4_group_extend_no_check(sb, o_blocks_count, add); 1646 return err; 1647 } /* ext4_group_extend */ 1648 1649 /* 1650 * ext4_resize_fs() resizes a fs to new size specified by @n_blocks_count 1651 * 1652 * @sb: super block of the fs to be resized 1653 * @n_blocks_count: the number of blocks resides in the resized fs 1654 */ 1655 int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count) 1656 { 1657 struct ext4_new_flex_group_data *flex_gd = NULL; 1658 struct ext4_sb_info *sbi = EXT4_SB(sb); 1659 struct ext4_super_block *es = sbi->s_es; 1660 struct buffer_head *bh; 1661 struct inode *resize_inode; 1662 ext4_fsblk_t o_blocks_count; 1663 ext4_group_t o_group; 1664 ext4_group_t n_group; 1665 ext4_grpblk_t offset, add; 1666 unsigned long n_desc_blocks; 1667 unsigned long o_desc_blocks; 1668 unsigned long desc_blocks; 1669 int err = 0, flexbg_size = 1 << sbi->s_log_groups_per_flex; 1670 1671 o_blocks_count = ext4_blocks_count(es); 1672 1673 if (test_opt(sb, DEBUG)) 1674 ext4_msg(sb, KERN_DEBUG, "resizing filesystem from %llu " 1675 "to %llu blocks", o_blocks_count, n_blocks_count); 1676 1677 if (n_blocks_count < o_blocks_count) { 1678 /* On-line shrinking not supported */ 1679 ext4_warning(sb, "can't shrink FS - resize aborted"); 1680 return -EINVAL; 1681 } 1682 1683 if (n_blocks_count == o_blocks_count) 1684 /* Nothing need to do */ 1685 return 0; 1686 1687 ext4_get_group_no_and_offset(sb, n_blocks_count - 1, &n_group, &offset); 1688 ext4_get_group_no_and_offset(sb, o_blocks_count - 1, &o_group, &offset); 1689 1690 n_desc_blocks = (n_group + EXT4_DESC_PER_BLOCK(sb)) / 1691 EXT4_DESC_PER_BLOCK(sb); 1692 o_desc_blocks = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) / 1693 EXT4_DESC_PER_BLOCK(sb); 1694 desc_blocks = n_desc_blocks - o_desc_blocks; 1695 1696 if (desc_blocks && 1697 (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_RESIZE_INODE) || 1698 le16_to_cpu(es->s_reserved_gdt_blocks) < desc_blocks)) { 1699 ext4_warning(sb, "No reserved GDT blocks, can't resize"); 1700 return -EPERM; 1701 } 1702 1703 resize_inode = ext4_iget(sb, EXT4_RESIZE_INO); 1704 if (IS_ERR(resize_inode)) { 1705 ext4_warning(sb, "Error opening resize inode"); 1706 return PTR_ERR(resize_inode); 1707 } 1708 1709 /* See if the device is actually as big as what was requested */ 1710 bh = sb_bread(sb, n_blocks_count - 1); 1711 if (!bh) { 1712 ext4_warning(sb, "can't read last block, resize aborted"); 1713 return -ENOSPC; 1714 } 1715 brelse(bh); 1716 1717 /* extend the last group */ 1718 if (n_group == o_group) 1719 add = n_blocks_count - o_blocks_count; 1720 else 1721 add = EXT4_BLOCKS_PER_GROUP(sb) - (offset + 1); 1722 if (add > 0) { 1723 err = ext4_group_extend_no_check(sb, o_blocks_count, add); 1724 if (err) 1725 goto out; 1726 } 1727 1728 if (ext4_blocks_count(es) == n_blocks_count) 1729 goto out; 1730 1731 err = ext4_alloc_flex_bg_array(sb, n_group + 1); 1732 if (err) 1733 return err; 1734 1735 flex_gd = alloc_flex_gd(flexbg_size); 1736 if (flex_gd == NULL) { 1737 err = -ENOMEM; 1738 goto out; 1739 } 1740 1741 /* Add flex groups. Note that a regular group is a 1742 * flex group with 1 group. 1743 */ 1744 while (ext4_setup_next_flex_gd(sb, flex_gd, n_blocks_count, 1745 flexbg_size)) { 1746 if (ext4_alloc_group_tables(sb, flex_gd, flexbg_size) != 0) 1747 break; 1748 err = ext4_flex_group_add(sb, resize_inode, flex_gd); 1749 if (unlikely(err)) 1750 break; 1751 } 1752 1753 out: 1754 if (flex_gd) 1755 free_flex_gd(flex_gd); 1756 1757 iput(resize_inode); 1758 if (test_opt(sb, DEBUG)) 1759 ext4_msg(sb, KERN_DEBUG, "resized filesystem from %llu " 1760 "upto %llu blocks", o_blocks_count, n_blocks_count); 1761 return err; 1762 } 1763