1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * linux/fs/ext4/resize.c 4 * 5 * Support for resizing an ext4 filesystem while it is mounted. 6 * 7 * Copyright (C) 2001, 2002 Andreas Dilger <adilger@clusterfs.com> 8 * 9 * This could probably be made into a module, because it is not often in use. 10 */ 11 12 13 #define EXT4FS_DEBUG 14 15 #include <linux/errno.h> 16 #include <linux/slab.h> 17 18 #include "ext4_jbd2.h" 19 20 int ext4_resize_begin(struct super_block *sb) 21 { 22 struct ext4_sb_info *sbi = EXT4_SB(sb); 23 int ret = 0; 24 25 if (!capable(CAP_SYS_RESOURCE)) 26 return -EPERM; 27 28 /* 29 * If we are not using the primary superblock/GDT copy don't resize, 30 * because the user tools have no way of handling this. Probably a 31 * bad time to do it anyways. 32 */ 33 if (EXT4_B2C(sbi, sbi->s_sbh->b_blocknr) != 34 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block)) { 35 ext4_warning(sb, "won't resize using backup superblock at %llu", 36 (unsigned long long)EXT4_SB(sb)->s_sbh->b_blocknr); 37 return -EPERM; 38 } 39 40 /* 41 * We are not allowed to do online-resizing on a filesystem mounted 42 * with error, because it can destroy the filesystem easily. 43 */ 44 if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) { 45 ext4_warning(sb, "There are errors in the filesystem, " 46 "so online resizing is not allowed"); 47 return -EPERM; 48 } 49 50 if (test_and_set_bit_lock(EXT4_FLAGS_RESIZING, 51 &EXT4_SB(sb)->s_ext4_flags)) 52 ret = -EBUSY; 53 54 return ret; 55 } 56 57 void ext4_resize_end(struct super_block *sb) 58 { 59 clear_bit_unlock(EXT4_FLAGS_RESIZING, &EXT4_SB(sb)->s_ext4_flags); 60 smp_mb__after_atomic(); 61 } 62 63 static ext4_group_t ext4_meta_bg_first_group(struct super_block *sb, 64 ext4_group_t group) { 65 return (group >> EXT4_DESC_PER_BLOCK_BITS(sb)) << 66 EXT4_DESC_PER_BLOCK_BITS(sb); 67 } 68 69 static ext4_fsblk_t ext4_meta_bg_first_block_no(struct super_block *sb, 70 ext4_group_t group) { 71 group = ext4_meta_bg_first_group(sb, group); 72 return ext4_group_first_block_no(sb, group); 73 } 74 75 static ext4_grpblk_t ext4_group_overhead_blocks(struct super_block *sb, 76 ext4_group_t group) { 77 ext4_grpblk_t overhead; 78 overhead = ext4_bg_num_gdb(sb, group); 79 if (ext4_bg_has_super(sb, group)) 80 overhead += 1 + 81 le16_to_cpu(EXT4_SB(sb)->s_es->s_reserved_gdt_blocks); 82 return overhead; 83 } 84 85 #define outside(b, first, last) ((b) < (first) || (b) >= (last)) 86 #define inside(b, first, last) ((b) >= (first) && (b) < (last)) 87 88 static int verify_group_input(struct super_block *sb, 89 struct ext4_new_group_data *input) 90 { 91 struct ext4_sb_info *sbi = EXT4_SB(sb); 92 struct ext4_super_block *es = sbi->s_es; 93 ext4_fsblk_t start = ext4_blocks_count(es); 94 ext4_fsblk_t end = start + input->blocks_count; 95 ext4_group_t group = input->group; 96 ext4_fsblk_t itend = input->inode_table + sbi->s_itb_per_group; 97 unsigned overhead; 98 ext4_fsblk_t metaend; 99 struct buffer_head *bh = NULL; 100 ext4_grpblk_t free_blocks_count, offset; 101 int err = -EINVAL; 102 103 if (group != sbi->s_groups_count) { 104 ext4_warning(sb, "Cannot add at group %u (only %u groups)", 105 input->group, sbi->s_groups_count); 106 return -EINVAL; 107 } 108 109 overhead = ext4_group_overhead_blocks(sb, group); 110 metaend = start + overhead; 111 input->free_clusters_count = free_blocks_count = 112 input->blocks_count - 2 - overhead - sbi->s_itb_per_group; 113 114 if (test_opt(sb, DEBUG)) 115 printk(KERN_DEBUG "EXT4-fs: adding %s group %u: %u blocks " 116 "(%d free, %u reserved)\n", 117 ext4_bg_has_super(sb, input->group) ? "normal" : 118 "no-super", input->group, input->blocks_count, 119 free_blocks_count, input->reserved_blocks); 120 121 ext4_get_group_no_and_offset(sb, start, NULL, &offset); 122 if (offset != 0) 123 ext4_warning(sb, "Last group not full"); 124 else if (input->reserved_blocks > input->blocks_count / 5) 125 ext4_warning(sb, "Reserved blocks too high (%u)", 126 input->reserved_blocks); 127 else if (free_blocks_count < 0) 128 ext4_warning(sb, "Bad blocks count %u", 129 input->blocks_count); 130 else if (!(bh = sb_bread(sb, end - 1))) 131 ext4_warning(sb, "Cannot read last block (%llu)", 132 end - 1); 133 else if (outside(input->block_bitmap, start, end)) 134 ext4_warning(sb, "Block bitmap not in group (block %llu)", 135 (unsigned long long)input->block_bitmap); 136 else if (outside(input->inode_bitmap, start, end)) 137 ext4_warning(sb, "Inode bitmap not in group (block %llu)", 138 (unsigned long long)input->inode_bitmap); 139 else if (outside(input->inode_table, start, end) || 140 outside(itend - 1, start, end)) 141 ext4_warning(sb, "Inode table not in group (blocks %llu-%llu)", 142 (unsigned long long)input->inode_table, itend - 1); 143 else if (input->inode_bitmap == input->block_bitmap) 144 ext4_warning(sb, "Block bitmap same as inode bitmap (%llu)", 145 (unsigned long long)input->block_bitmap); 146 else if (inside(input->block_bitmap, input->inode_table, itend)) 147 ext4_warning(sb, "Block bitmap (%llu) in inode table " 148 "(%llu-%llu)", 149 (unsigned long long)input->block_bitmap, 150 (unsigned long long)input->inode_table, itend - 1); 151 else if (inside(input->inode_bitmap, input->inode_table, itend)) 152 ext4_warning(sb, "Inode bitmap (%llu) in inode table " 153 "(%llu-%llu)", 154 (unsigned long long)input->inode_bitmap, 155 (unsigned long long)input->inode_table, itend - 1); 156 else if (inside(input->block_bitmap, start, metaend)) 157 ext4_warning(sb, "Block bitmap (%llu) in GDT table (%llu-%llu)", 158 (unsigned long long)input->block_bitmap, 159 start, metaend - 1); 160 else if (inside(input->inode_bitmap, start, metaend)) 161 ext4_warning(sb, "Inode bitmap (%llu) in GDT table (%llu-%llu)", 162 (unsigned long long)input->inode_bitmap, 163 start, metaend - 1); 164 else if (inside(input->inode_table, start, metaend) || 165 inside(itend - 1, start, metaend)) 166 ext4_warning(sb, "Inode table (%llu-%llu) overlaps GDT table " 167 "(%llu-%llu)", 168 (unsigned long long)input->inode_table, 169 itend - 1, start, metaend - 1); 170 else 171 err = 0; 172 brelse(bh); 173 174 return err; 175 } 176 177 /* 178 * ext4_new_flex_group_data is used by 64bit-resize interface to add a flex 179 * group each time. 180 */ 181 struct ext4_new_flex_group_data { 182 struct ext4_new_group_data *groups; /* new_group_data for groups 183 in the flex group */ 184 __u16 *bg_flags; /* block group flags of groups 185 in @groups */ 186 ext4_group_t count; /* number of groups in @groups 187 */ 188 }; 189 190 /* 191 * alloc_flex_gd() allocates a ext4_new_flex_group_data with size of 192 * @flexbg_size. 193 * 194 * Returns NULL on failure otherwise address of the allocated structure. 195 */ 196 static struct ext4_new_flex_group_data *alloc_flex_gd(unsigned long flexbg_size) 197 { 198 struct ext4_new_flex_group_data *flex_gd; 199 200 flex_gd = kmalloc(sizeof(*flex_gd), GFP_NOFS); 201 if (flex_gd == NULL) 202 goto out3; 203 204 if (flexbg_size >= UINT_MAX / sizeof(struct ext4_new_group_data)) 205 goto out2; 206 flex_gd->count = flexbg_size; 207 208 flex_gd->groups = kmalloc_array(flexbg_size, 209 sizeof(struct ext4_new_group_data), 210 GFP_NOFS); 211 if (flex_gd->groups == NULL) 212 goto out2; 213 214 flex_gd->bg_flags = kmalloc_array(flexbg_size, sizeof(__u16), 215 GFP_NOFS); 216 if (flex_gd->bg_flags == NULL) 217 goto out1; 218 219 return flex_gd; 220 221 out1: 222 kfree(flex_gd->groups); 223 out2: 224 kfree(flex_gd); 225 out3: 226 return NULL; 227 } 228 229 static void free_flex_gd(struct ext4_new_flex_group_data *flex_gd) 230 { 231 kfree(flex_gd->bg_flags); 232 kfree(flex_gd->groups); 233 kfree(flex_gd); 234 } 235 236 /* 237 * ext4_alloc_group_tables() allocates block bitmaps, inode bitmaps 238 * and inode tables for a flex group. 239 * 240 * This function is used by 64bit-resize. Note that this function allocates 241 * group tables from the 1st group of groups contained by @flexgd, which may 242 * be a partial of a flex group. 243 * 244 * @sb: super block of fs to which the groups belongs 245 * 246 * Returns 0 on a successful allocation of the metadata blocks in the 247 * block group. 248 */ 249 static int ext4_alloc_group_tables(struct super_block *sb, 250 struct ext4_new_flex_group_data *flex_gd, 251 int flexbg_size) 252 { 253 struct ext4_new_group_data *group_data = flex_gd->groups; 254 ext4_fsblk_t start_blk; 255 ext4_fsblk_t last_blk; 256 ext4_group_t src_group; 257 ext4_group_t bb_index = 0; 258 ext4_group_t ib_index = 0; 259 ext4_group_t it_index = 0; 260 ext4_group_t group; 261 ext4_group_t last_group; 262 unsigned overhead; 263 __u16 uninit_mask = (flexbg_size > 1) ? ~EXT4_BG_BLOCK_UNINIT : ~0; 264 int i; 265 266 BUG_ON(flex_gd->count == 0 || group_data == NULL); 267 268 src_group = group_data[0].group; 269 last_group = src_group + flex_gd->count - 1; 270 271 BUG_ON((flexbg_size > 1) && ((src_group & ~(flexbg_size - 1)) != 272 (last_group & ~(flexbg_size - 1)))); 273 next_group: 274 group = group_data[0].group; 275 if (src_group >= group_data[0].group + flex_gd->count) 276 return -ENOSPC; 277 start_blk = ext4_group_first_block_no(sb, src_group); 278 last_blk = start_blk + group_data[src_group - group].blocks_count; 279 280 overhead = ext4_group_overhead_blocks(sb, src_group); 281 282 start_blk += overhead; 283 284 /* We collect contiguous blocks as much as possible. */ 285 src_group++; 286 for (; src_group <= last_group; src_group++) { 287 overhead = ext4_group_overhead_blocks(sb, src_group); 288 if (overhead == 0) 289 last_blk += group_data[src_group - group].blocks_count; 290 else 291 break; 292 } 293 294 /* Allocate block bitmaps */ 295 for (; bb_index < flex_gd->count; bb_index++) { 296 if (start_blk >= last_blk) 297 goto next_group; 298 group_data[bb_index].block_bitmap = start_blk++; 299 group = ext4_get_group_number(sb, start_blk - 1); 300 group -= group_data[0].group; 301 group_data[group].mdata_blocks++; 302 flex_gd->bg_flags[group] &= uninit_mask; 303 } 304 305 /* Allocate inode bitmaps */ 306 for (; ib_index < flex_gd->count; ib_index++) { 307 if (start_blk >= last_blk) 308 goto next_group; 309 group_data[ib_index].inode_bitmap = start_blk++; 310 group = ext4_get_group_number(sb, start_blk - 1); 311 group -= group_data[0].group; 312 group_data[group].mdata_blocks++; 313 flex_gd->bg_flags[group] &= uninit_mask; 314 } 315 316 /* Allocate inode tables */ 317 for (; it_index < flex_gd->count; it_index++) { 318 unsigned int itb = EXT4_SB(sb)->s_itb_per_group; 319 ext4_fsblk_t next_group_start; 320 321 if (start_blk + itb > last_blk) 322 goto next_group; 323 group_data[it_index].inode_table = start_blk; 324 group = ext4_get_group_number(sb, start_blk); 325 next_group_start = ext4_group_first_block_no(sb, group + 1); 326 group -= group_data[0].group; 327 328 if (start_blk + itb > next_group_start) { 329 flex_gd->bg_flags[group + 1] &= uninit_mask; 330 overhead = start_blk + itb - next_group_start; 331 group_data[group + 1].mdata_blocks += overhead; 332 itb -= overhead; 333 } 334 335 group_data[group].mdata_blocks += itb; 336 flex_gd->bg_flags[group] &= uninit_mask; 337 start_blk += EXT4_SB(sb)->s_itb_per_group; 338 } 339 340 /* Update free clusters count to exclude metadata blocks */ 341 for (i = 0; i < flex_gd->count; i++) { 342 group_data[i].free_clusters_count -= 343 EXT4_NUM_B2C(EXT4_SB(sb), 344 group_data[i].mdata_blocks); 345 } 346 347 if (test_opt(sb, DEBUG)) { 348 int i; 349 group = group_data[0].group; 350 351 printk(KERN_DEBUG "EXT4-fs: adding a flex group with " 352 "%d groups, flexbg size is %d:\n", flex_gd->count, 353 flexbg_size); 354 355 for (i = 0; i < flex_gd->count; i++) { 356 ext4_debug( 357 "adding %s group %u: %u blocks (%d free, %d mdata blocks)\n", 358 ext4_bg_has_super(sb, group + i) ? "normal" : 359 "no-super", group + i, 360 group_data[i].blocks_count, 361 group_data[i].free_clusters_count, 362 group_data[i].mdata_blocks); 363 } 364 } 365 return 0; 366 } 367 368 static struct buffer_head *bclean(handle_t *handle, struct super_block *sb, 369 ext4_fsblk_t blk) 370 { 371 struct buffer_head *bh; 372 int err; 373 374 bh = sb_getblk(sb, blk); 375 if (unlikely(!bh)) 376 return ERR_PTR(-ENOMEM); 377 BUFFER_TRACE(bh, "get_write_access"); 378 if ((err = ext4_journal_get_write_access(handle, bh))) { 379 brelse(bh); 380 bh = ERR_PTR(err); 381 } else { 382 memset(bh->b_data, 0, sb->s_blocksize); 383 set_buffer_uptodate(bh); 384 } 385 386 return bh; 387 } 388 389 /* 390 * If we have fewer than thresh credits, extend by EXT4_MAX_TRANS_DATA. 391 * If that fails, restart the transaction & regain write access for the 392 * buffer head which is used for block_bitmap modifications. 393 */ 394 static int extend_or_restart_transaction(handle_t *handle, int thresh) 395 { 396 int err; 397 398 if (ext4_handle_has_enough_credits(handle, thresh)) 399 return 0; 400 401 err = ext4_journal_extend(handle, EXT4_MAX_TRANS_DATA); 402 if (err < 0) 403 return err; 404 if (err) { 405 err = ext4_journal_restart(handle, EXT4_MAX_TRANS_DATA); 406 if (err) 407 return err; 408 } 409 410 return 0; 411 } 412 413 /* 414 * set_flexbg_block_bitmap() mark clusters [@first_cluster, @last_cluster] used. 415 * 416 * Helper function for ext4_setup_new_group_blocks() which set . 417 * 418 * @sb: super block 419 * @handle: journal handle 420 * @flex_gd: flex group data 421 */ 422 static int set_flexbg_block_bitmap(struct super_block *sb, handle_t *handle, 423 struct ext4_new_flex_group_data *flex_gd, 424 ext4_fsblk_t first_cluster, ext4_fsblk_t last_cluster) 425 { 426 struct ext4_sb_info *sbi = EXT4_SB(sb); 427 ext4_group_t count = last_cluster - first_cluster + 1; 428 ext4_group_t count2; 429 430 ext4_debug("mark clusters [%llu-%llu] used\n", first_cluster, 431 last_cluster); 432 for (count2 = count; count > 0; 433 count -= count2, first_cluster += count2) { 434 ext4_fsblk_t start; 435 struct buffer_head *bh; 436 ext4_group_t group; 437 int err; 438 439 group = ext4_get_group_number(sb, EXT4_C2B(sbi, first_cluster)); 440 start = EXT4_B2C(sbi, ext4_group_first_block_no(sb, group)); 441 group -= flex_gd->groups[0].group; 442 443 count2 = EXT4_CLUSTERS_PER_GROUP(sb) - (first_cluster - start); 444 if (count2 > count) 445 count2 = count; 446 447 if (flex_gd->bg_flags[group] & EXT4_BG_BLOCK_UNINIT) { 448 BUG_ON(flex_gd->count > 1); 449 continue; 450 } 451 452 err = extend_or_restart_transaction(handle, 1); 453 if (err) 454 return err; 455 456 bh = sb_getblk(sb, flex_gd->groups[group].block_bitmap); 457 if (unlikely(!bh)) 458 return -ENOMEM; 459 460 BUFFER_TRACE(bh, "get_write_access"); 461 err = ext4_journal_get_write_access(handle, bh); 462 if (err) { 463 brelse(bh); 464 return err; 465 } 466 ext4_debug("mark block bitmap %#04llx (+%llu/%u)\n", 467 first_cluster, first_cluster - start, count2); 468 ext4_set_bits(bh->b_data, first_cluster - start, count2); 469 470 err = ext4_handle_dirty_metadata(handle, NULL, bh); 471 brelse(bh); 472 if (unlikely(err)) 473 return err; 474 } 475 476 return 0; 477 } 478 479 /* 480 * Set up the block and inode bitmaps, and the inode table for the new groups. 481 * This doesn't need to be part of the main transaction, since we are only 482 * changing blocks outside the actual filesystem. We still do journaling to 483 * ensure the recovery is correct in case of a failure just after resize. 484 * If any part of this fails, we simply abort the resize. 485 * 486 * setup_new_flex_group_blocks handles a flex group as follow: 487 * 1. copy super block and GDT, and initialize group tables if necessary. 488 * In this step, we only set bits in blocks bitmaps for blocks taken by 489 * super block and GDT. 490 * 2. allocate group tables in block bitmaps, that is, set bits in block 491 * bitmap for blocks taken by group tables. 492 */ 493 static int setup_new_flex_group_blocks(struct super_block *sb, 494 struct ext4_new_flex_group_data *flex_gd) 495 { 496 int group_table_count[] = {1, 1, EXT4_SB(sb)->s_itb_per_group}; 497 ext4_fsblk_t start; 498 ext4_fsblk_t block; 499 struct ext4_sb_info *sbi = EXT4_SB(sb); 500 struct ext4_super_block *es = sbi->s_es; 501 struct ext4_new_group_data *group_data = flex_gd->groups; 502 __u16 *bg_flags = flex_gd->bg_flags; 503 handle_t *handle; 504 ext4_group_t group, count; 505 struct buffer_head *bh = NULL; 506 int reserved_gdb, i, j, err = 0, err2; 507 int meta_bg; 508 509 BUG_ON(!flex_gd->count || !group_data || 510 group_data[0].group != sbi->s_groups_count); 511 512 reserved_gdb = le16_to_cpu(es->s_reserved_gdt_blocks); 513 meta_bg = ext4_has_feature_meta_bg(sb); 514 515 /* This transaction may be extended/restarted along the way */ 516 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, EXT4_MAX_TRANS_DATA); 517 if (IS_ERR(handle)) 518 return PTR_ERR(handle); 519 520 group = group_data[0].group; 521 for (i = 0; i < flex_gd->count; i++, group++) { 522 unsigned long gdblocks; 523 ext4_grpblk_t overhead; 524 525 gdblocks = ext4_bg_num_gdb(sb, group); 526 start = ext4_group_first_block_no(sb, group); 527 528 if (meta_bg == 0 && !ext4_bg_has_super(sb, group)) 529 goto handle_itb; 530 531 if (meta_bg == 1) { 532 ext4_group_t first_group; 533 first_group = ext4_meta_bg_first_group(sb, group); 534 if (first_group != group + 1 && 535 first_group != group + EXT4_DESC_PER_BLOCK(sb) - 1) 536 goto handle_itb; 537 } 538 539 block = start + ext4_bg_has_super(sb, group); 540 /* Copy all of the GDT blocks into the backup in this group */ 541 for (j = 0; j < gdblocks; j++, block++) { 542 struct buffer_head *gdb; 543 544 ext4_debug("update backup group %#04llx\n", block); 545 err = extend_or_restart_transaction(handle, 1); 546 if (err) 547 goto out; 548 549 gdb = sb_getblk(sb, block); 550 if (unlikely(!gdb)) { 551 err = -ENOMEM; 552 goto out; 553 } 554 555 BUFFER_TRACE(gdb, "get_write_access"); 556 err = ext4_journal_get_write_access(handle, gdb); 557 if (err) { 558 brelse(gdb); 559 goto out; 560 } 561 memcpy(gdb->b_data, sbi->s_group_desc[j]->b_data, 562 gdb->b_size); 563 set_buffer_uptodate(gdb); 564 565 err = ext4_handle_dirty_metadata(handle, NULL, gdb); 566 if (unlikely(err)) { 567 brelse(gdb); 568 goto out; 569 } 570 brelse(gdb); 571 } 572 573 /* Zero out all of the reserved backup group descriptor 574 * table blocks 575 */ 576 if (ext4_bg_has_super(sb, group)) { 577 err = sb_issue_zeroout(sb, gdblocks + start + 1, 578 reserved_gdb, GFP_NOFS); 579 if (err) 580 goto out; 581 } 582 583 handle_itb: 584 /* Initialize group tables of the grop @group */ 585 if (!(bg_flags[i] & EXT4_BG_INODE_ZEROED)) 586 goto handle_bb; 587 588 /* Zero out all of the inode table blocks */ 589 block = group_data[i].inode_table; 590 ext4_debug("clear inode table blocks %#04llx -> %#04lx\n", 591 block, sbi->s_itb_per_group); 592 err = sb_issue_zeroout(sb, block, sbi->s_itb_per_group, 593 GFP_NOFS); 594 if (err) 595 goto out; 596 597 handle_bb: 598 if (bg_flags[i] & EXT4_BG_BLOCK_UNINIT) 599 goto handle_ib; 600 601 /* Initialize block bitmap of the @group */ 602 block = group_data[i].block_bitmap; 603 err = extend_or_restart_transaction(handle, 1); 604 if (err) 605 goto out; 606 607 bh = bclean(handle, sb, block); 608 if (IS_ERR(bh)) { 609 err = PTR_ERR(bh); 610 goto out; 611 } 612 overhead = ext4_group_overhead_blocks(sb, group); 613 if (overhead != 0) { 614 ext4_debug("mark backup superblock %#04llx (+0)\n", 615 start); 616 ext4_set_bits(bh->b_data, 0, 617 EXT4_NUM_B2C(sbi, overhead)); 618 } 619 ext4_mark_bitmap_end(EXT4_B2C(sbi, group_data[i].blocks_count), 620 sb->s_blocksize * 8, bh->b_data); 621 err = ext4_handle_dirty_metadata(handle, NULL, bh); 622 brelse(bh); 623 if (err) 624 goto out; 625 626 handle_ib: 627 if (bg_flags[i] & EXT4_BG_INODE_UNINIT) 628 continue; 629 630 /* Initialize inode bitmap of the @group */ 631 block = group_data[i].inode_bitmap; 632 err = extend_or_restart_transaction(handle, 1); 633 if (err) 634 goto out; 635 /* Mark unused entries in inode bitmap used */ 636 bh = bclean(handle, sb, block); 637 if (IS_ERR(bh)) { 638 err = PTR_ERR(bh); 639 goto out; 640 } 641 642 ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb), 643 sb->s_blocksize * 8, bh->b_data); 644 err = ext4_handle_dirty_metadata(handle, NULL, bh); 645 brelse(bh); 646 if (err) 647 goto out; 648 } 649 650 /* Mark group tables in block bitmap */ 651 for (j = 0; j < GROUP_TABLE_COUNT; j++) { 652 count = group_table_count[j]; 653 start = (&group_data[0].block_bitmap)[j]; 654 block = start; 655 for (i = 1; i < flex_gd->count; i++) { 656 block += group_table_count[j]; 657 if (block == (&group_data[i].block_bitmap)[j]) { 658 count += group_table_count[j]; 659 continue; 660 } 661 err = set_flexbg_block_bitmap(sb, handle, 662 flex_gd, 663 EXT4_B2C(sbi, start), 664 EXT4_B2C(sbi, 665 start + count 666 - 1)); 667 if (err) 668 goto out; 669 count = group_table_count[j]; 670 start = (&group_data[i].block_bitmap)[j]; 671 block = start; 672 } 673 674 if (count) { 675 err = set_flexbg_block_bitmap(sb, handle, 676 flex_gd, 677 EXT4_B2C(sbi, start), 678 EXT4_B2C(sbi, 679 start + count 680 - 1)); 681 if (err) 682 goto out; 683 } 684 } 685 686 out: 687 err2 = ext4_journal_stop(handle); 688 if (err2 && !err) 689 err = err2; 690 691 return err; 692 } 693 694 /* 695 * Iterate through the groups which hold BACKUP superblock/GDT copies in an 696 * ext4 filesystem. The counters should be initialized to 1, 5, and 7 before 697 * calling this for the first time. In a sparse filesystem it will be the 698 * sequence of powers of 3, 5, and 7: 1, 3, 5, 7, 9, 25, 27, 49, 81, ... 699 * For a non-sparse filesystem it will be every group: 1, 2, 3, 4, ... 700 */ 701 static unsigned ext4_list_backups(struct super_block *sb, unsigned *three, 702 unsigned *five, unsigned *seven) 703 { 704 unsigned *min = three; 705 int mult = 3; 706 unsigned ret; 707 708 if (!ext4_has_feature_sparse_super(sb)) { 709 ret = *min; 710 *min += 1; 711 return ret; 712 } 713 714 if (*five < *min) { 715 min = five; 716 mult = 5; 717 } 718 if (*seven < *min) { 719 min = seven; 720 mult = 7; 721 } 722 723 ret = *min; 724 *min *= mult; 725 726 return ret; 727 } 728 729 /* 730 * Check that all of the backup GDT blocks are held in the primary GDT block. 731 * It is assumed that they are stored in group order. Returns the number of 732 * groups in current filesystem that have BACKUPS, or -ve error code. 733 */ 734 static int verify_reserved_gdb(struct super_block *sb, 735 ext4_group_t end, 736 struct buffer_head *primary) 737 { 738 const ext4_fsblk_t blk = primary->b_blocknr; 739 unsigned three = 1; 740 unsigned five = 5; 741 unsigned seven = 7; 742 unsigned grp; 743 __le32 *p = (__le32 *)primary->b_data; 744 int gdbackups = 0; 745 746 while ((grp = ext4_list_backups(sb, &three, &five, &seven)) < end) { 747 if (le32_to_cpu(*p++) != 748 grp * EXT4_BLOCKS_PER_GROUP(sb) + blk){ 749 ext4_warning(sb, "reserved GDT %llu" 750 " missing grp %d (%llu)", 751 blk, grp, 752 grp * 753 (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) + 754 blk); 755 return -EINVAL; 756 } 757 if (++gdbackups > EXT4_ADDR_PER_BLOCK(sb)) 758 return -EFBIG; 759 } 760 761 return gdbackups; 762 } 763 764 /* 765 * Called when we need to bring a reserved group descriptor table block into 766 * use from the resize inode. The primary copy of the new GDT block currently 767 * is an indirect block (under the double indirect block in the resize inode). 768 * The new backup GDT blocks will be stored as leaf blocks in this indirect 769 * block, in group order. Even though we know all the block numbers we need, 770 * we check to ensure that the resize inode has actually reserved these blocks. 771 * 772 * Don't need to update the block bitmaps because the blocks are still in use. 773 * 774 * We get all of the error cases out of the way, so that we are sure to not 775 * fail once we start modifying the data on disk, because JBD has no rollback. 776 */ 777 static int add_new_gdb(handle_t *handle, struct inode *inode, 778 ext4_group_t group) 779 { 780 struct super_block *sb = inode->i_sb; 781 struct ext4_super_block *es = EXT4_SB(sb)->s_es; 782 unsigned long gdb_num = group / EXT4_DESC_PER_BLOCK(sb); 783 ext4_fsblk_t gdblock = EXT4_SB(sb)->s_sbh->b_blocknr + 1 + gdb_num; 784 struct buffer_head **o_group_desc, **n_group_desc; 785 struct buffer_head *dind; 786 struct buffer_head *gdb_bh; 787 int gdbackups; 788 struct ext4_iloc iloc; 789 __le32 *data; 790 int err; 791 792 if (test_opt(sb, DEBUG)) 793 printk(KERN_DEBUG 794 "EXT4-fs: ext4_add_new_gdb: adding group block %lu\n", 795 gdb_num); 796 797 gdb_bh = sb_bread(sb, gdblock); 798 if (!gdb_bh) 799 return -EIO; 800 801 gdbackups = verify_reserved_gdb(sb, group, gdb_bh); 802 if (gdbackups < 0) { 803 err = gdbackups; 804 goto exit_bh; 805 } 806 807 data = EXT4_I(inode)->i_data + EXT4_DIND_BLOCK; 808 dind = sb_bread(sb, le32_to_cpu(*data)); 809 if (!dind) { 810 err = -EIO; 811 goto exit_bh; 812 } 813 814 data = (__le32 *)dind->b_data; 815 if (le32_to_cpu(data[gdb_num % EXT4_ADDR_PER_BLOCK(sb)]) != gdblock) { 816 ext4_warning(sb, "new group %u GDT block %llu not reserved", 817 group, gdblock); 818 err = -EINVAL; 819 goto exit_dind; 820 } 821 822 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access"); 823 err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh); 824 if (unlikely(err)) 825 goto exit_dind; 826 827 BUFFER_TRACE(gdb_bh, "get_write_access"); 828 err = ext4_journal_get_write_access(handle, gdb_bh); 829 if (unlikely(err)) 830 goto exit_dind; 831 832 BUFFER_TRACE(dind, "get_write_access"); 833 err = ext4_journal_get_write_access(handle, dind); 834 if (unlikely(err)) 835 ext4_std_error(sb, err); 836 837 /* ext4_reserve_inode_write() gets a reference on the iloc */ 838 err = ext4_reserve_inode_write(handle, inode, &iloc); 839 if (unlikely(err)) 840 goto exit_dind; 841 842 n_group_desc = ext4_kvmalloc((gdb_num + 1) * 843 sizeof(struct buffer_head *), 844 GFP_NOFS); 845 if (!n_group_desc) { 846 err = -ENOMEM; 847 ext4_warning(sb, "not enough memory for %lu groups", 848 gdb_num + 1); 849 goto exit_inode; 850 } 851 852 /* 853 * Finally, we have all of the possible failures behind us... 854 * 855 * Remove new GDT block from inode double-indirect block and clear out 856 * the new GDT block for use (which also "frees" the backup GDT blocks 857 * from the reserved inode). We don't need to change the bitmaps for 858 * these blocks, because they are marked as in-use from being in the 859 * reserved inode, and will become GDT blocks (primary and backup). 860 */ 861 data[gdb_num % EXT4_ADDR_PER_BLOCK(sb)] = 0; 862 err = ext4_handle_dirty_metadata(handle, NULL, dind); 863 if (unlikely(err)) { 864 ext4_std_error(sb, err); 865 goto exit_inode; 866 } 867 inode->i_blocks -= (gdbackups + 1) * sb->s_blocksize >> 868 (9 - EXT4_SB(sb)->s_cluster_bits); 869 ext4_mark_iloc_dirty(handle, inode, &iloc); 870 memset(gdb_bh->b_data, 0, sb->s_blocksize); 871 err = ext4_handle_dirty_metadata(handle, NULL, gdb_bh); 872 if (unlikely(err)) { 873 ext4_std_error(sb, err); 874 goto exit_inode; 875 } 876 brelse(dind); 877 878 o_group_desc = EXT4_SB(sb)->s_group_desc; 879 memcpy(n_group_desc, o_group_desc, 880 EXT4_SB(sb)->s_gdb_count * sizeof(struct buffer_head *)); 881 n_group_desc[gdb_num] = gdb_bh; 882 EXT4_SB(sb)->s_group_desc = n_group_desc; 883 EXT4_SB(sb)->s_gdb_count++; 884 kvfree(o_group_desc); 885 886 le16_add_cpu(&es->s_reserved_gdt_blocks, -1); 887 err = ext4_handle_dirty_super(handle, sb); 888 if (err) 889 ext4_std_error(sb, err); 890 891 return err; 892 893 exit_inode: 894 kvfree(n_group_desc); 895 brelse(iloc.bh); 896 exit_dind: 897 brelse(dind); 898 exit_bh: 899 brelse(gdb_bh); 900 901 ext4_debug("leaving with error %d\n", err); 902 return err; 903 } 904 905 /* 906 * add_new_gdb_meta_bg is the sister of add_new_gdb. 907 */ 908 static int add_new_gdb_meta_bg(struct super_block *sb, 909 handle_t *handle, ext4_group_t group) { 910 ext4_fsblk_t gdblock; 911 struct buffer_head *gdb_bh; 912 struct buffer_head **o_group_desc, **n_group_desc; 913 unsigned long gdb_num = group / EXT4_DESC_PER_BLOCK(sb); 914 int err; 915 916 gdblock = ext4_meta_bg_first_block_no(sb, group) + 917 ext4_bg_has_super(sb, group); 918 gdb_bh = sb_bread(sb, gdblock); 919 if (!gdb_bh) 920 return -EIO; 921 n_group_desc = ext4_kvmalloc((gdb_num + 1) * 922 sizeof(struct buffer_head *), 923 GFP_NOFS); 924 if (!n_group_desc) { 925 brelse(gdb_bh); 926 err = -ENOMEM; 927 ext4_warning(sb, "not enough memory for %lu groups", 928 gdb_num + 1); 929 return err; 930 } 931 932 o_group_desc = EXT4_SB(sb)->s_group_desc; 933 memcpy(n_group_desc, o_group_desc, 934 EXT4_SB(sb)->s_gdb_count * sizeof(struct buffer_head *)); 935 n_group_desc[gdb_num] = gdb_bh; 936 EXT4_SB(sb)->s_group_desc = n_group_desc; 937 EXT4_SB(sb)->s_gdb_count++; 938 kvfree(o_group_desc); 939 BUFFER_TRACE(gdb_bh, "get_write_access"); 940 err = ext4_journal_get_write_access(handle, gdb_bh); 941 return err; 942 } 943 944 /* 945 * Called when we are adding a new group which has a backup copy of each of 946 * the GDT blocks (i.e. sparse group) and there are reserved GDT blocks. 947 * We need to add these reserved backup GDT blocks to the resize inode, so 948 * that they are kept for future resizing and not allocated to files. 949 * 950 * Each reserved backup GDT block will go into a different indirect block. 951 * The indirect blocks are actually the primary reserved GDT blocks, 952 * so we know in advance what their block numbers are. We only get the 953 * double-indirect block to verify it is pointing to the primary reserved 954 * GDT blocks so we don't overwrite a data block by accident. The reserved 955 * backup GDT blocks are stored in their reserved primary GDT block. 956 */ 957 static int reserve_backup_gdb(handle_t *handle, struct inode *inode, 958 ext4_group_t group) 959 { 960 struct super_block *sb = inode->i_sb; 961 int reserved_gdb =le16_to_cpu(EXT4_SB(sb)->s_es->s_reserved_gdt_blocks); 962 int cluster_bits = EXT4_SB(sb)->s_cluster_bits; 963 struct buffer_head **primary; 964 struct buffer_head *dind; 965 struct ext4_iloc iloc; 966 ext4_fsblk_t blk; 967 __le32 *data, *end; 968 int gdbackups = 0; 969 int res, i; 970 int err; 971 972 primary = kmalloc_array(reserved_gdb, sizeof(*primary), GFP_NOFS); 973 if (!primary) 974 return -ENOMEM; 975 976 data = EXT4_I(inode)->i_data + EXT4_DIND_BLOCK; 977 dind = sb_bread(sb, le32_to_cpu(*data)); 978 if (!dind) { 979 err = -EIO; 980 goto exit_free; 981 } 982 983 blk = EXT4_SB(sb)->s_sbh->b_blocknr + 1 + EXT4_SB(sb)->s_gdb_count; 984 data = (__le32 *)dind->b_data + (EXT4_SB(sb)->s_gdb_count % 985 EXT4_ADDR_PER_BLOCK(sb)); 986 end = (__le32 *)dind->b_data + EXT4_ADDR_PER_BLOCK(sb); 987 988 /* Get each reserved primary GDT block and verify it holds backups */ 989 for (res = 0; res < reserved_gdb; res++, blk++) { 990 if (le32_to_cpu(*data) != blk) { 991 ext4_warning(sb, "reserved block %llu" 992 " not at offset %ld", 993 blk, 994 (long)(data - (__le32 *)dind->b_data)); 995 err = -EINVAL; 996 goto exit_bh; 997 } 998 primary[res] = sb_bread(sb, blk); 999 if (!primary[res]) { 1000 err = -EIO; 1001 goto exit_bh; 1002 } 1003 gdbackups = verify_reserved_gdb(sb, group, primary[res]); 1004 if (gdbackups < 0) { 1005 brelse(primary[res]); 1006 err = gdbackups; 1007 goto exit_bh; 1008 } 1009 if (++data >= end) 1010 data = (__le32 *)dind->b_data; 1011 } 1012 1013 for (i = 0; i < reserved_gdb; i++) { 1014 BUFFER_TRACE(primary[i], "get_write_access"); 1015 if ((err = ext4_journal_get_write_access(handle, primary[i]))) 1016 goto exit_bh; 1017 } 1018 1019 if ((err = ext4_reserve_inode_write(handle, inode, &iloc))) 1020 goto exit_bh; 1021 1022 /* 1023 * Finally we can add each of the reserved backup GDT blocks from 1024 * the new group to its reserved primary GDT block. 1025 */ 1026 blk = group * EXT4_BLOCKS_PER_GROUP(sb); 1027 for (i = 0; i < reserved_gdb; i++) { 1028 int err2; 1029 data = (__le32 *)primary[i]->b_data; 1030 /* printk("reserving backup %lu[%u] = %lu\n", 1031 primary[i]->b_blocknr, gdbackups, 1032 blk + primary[i]->b_blocknr); */ 1033 data[gdbackups] = cpu_to_le32(blk + primary[i]->b_blocknr); 1034 err2 = ext4_handle_dirty_metadata(handle, NULL, primary[i]); 1035 if (!err) 1036 err = err2; 1037 } 1038 1039 inode->i_blocks += reserved_gdb * sb->s_blocksize >> (9 - cluster_bits); 1040 ext4_mark_iloc_dirty(handle, inode, &iloc); 1041 1042 exit_bh: 1043 while (--res >= 0) 1044 brelse(primary[res]); 1045 brelse(dind); 1046 1047 exit_free: 1048 kfree(primary); 1049 1050 return err; 1051 } 1052 1053 /* 1054 * Update the backup copies of the ext4 metadata. These don't need to be part 1055 * of the main resize transaction, because e2fsck will re-write them if there 1056 * is a problem (basically only OOM will cause a problem). However, we 1057 * _should_ update the backups if possible, in case the primary gets trashed 1058 * for some reason and we need to run e2fsck from a backup superblock. The 1059 * important part is that the new block and inode counts are in the backup 1060 * superblocks, and the location of the new group metadata in the GDT backups. 1061 * 1062 * We do not need take the s_resize_lock for this, because these 1063 * blocks are not otherwise touched by the filesystem code when it is 1064 * mounted. We don't need to worry about last changing from 1065 * sbi->s_groups_count, because the worst that can happen is that we 1066 * do not copy the full number of backups at this time. The resize 1067 * which changed s_groups_count will backup again. 1068 */ 1069 static void update_backups(struct super_block *sb, sector_t blk_off, char *data, 1070 int size, int meta_bg) 1071 { 1072 struct ext4_sb_info *sbi = EXT4_SB(sb); 1073 ext4_group_t last; 1074 const int bpg = EXT4_BLOCKS_PER_GROUP(sb); 1075 unsigned three = 1; 1076 unsigned five = 5; 1077 unsigned seven = 7; 1078 ext4_group_t group = 0; 1079 int rest = sb->s_blocksize - size; 1080 handle_t *handle; 1081 int err = 0, err2; 1082 1083 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, EXT4_MAX_TRANS_DATA); 1084 if (IS_ERR(handle)) { 1085 group = 1; 1086 err = PTR_ERR(handle); 1087 goto exit_err; 1088 } 1089 1090 if (meta_bg == 0) { 1091 group = ext4_list_backups(sb, &three, &five, &seven); 1092 last = sbi->s_groups_count; 1093 } else { 1094 group = ext4_get_group_number(sb, blk_off) + 1; 1095 last = (ext4_group_t)(group + EXT4_DESC_PER_BLOCK(sb) - 2); 1096 } 1097 1098 while (group < sbi->s_groups_count) { 1099 struct buffer_head *bh; 1100 ext4_fsblk_t backup_block; 1101 1102 /* Out of journal space, and can't get more - abort - so sad */ 1103 if (ext4_handle_valid(handle) && 1104 handle->h_buffer_credits == 0 && 1105 ext4_journal_extend(handle, EXT4_MAX_TRANS_DATA) && 1106 (err = ext4_journal_restart(handle, EXT4_MAX_TRANS_DATA))) 1107 break; 1108 1109 if (meta_bg == 0) 1110 backup_block = ((ext4_fsblk_t)group) * bpg + blk_off; 1111 else 1112 backup_block = (ext4_group_first_block_no(sb, group) + 1113 ext4_bg_has_super(sb, group)); 1114 1115 bh = sb_getblk(sb, backup_block); 1116 if (unlikely(!bh)) { 1117 err = -ENOMEM; 1118 break; 1119 } 1120 ext4_debug("update metadata backup %llu(+%llu)\n", 1121 backup_block, backup_block - 1122 ext4_group_first_block_no(sb, group)); 1123 BUFFER_TRACE(bh, "get_write_access"); 1124 if ((err = ext4_journal_get_write_access(handle, bh))) 1125 break; 1126 lock_buffer(bh); 1127 memcpy(bh->b_data, data, size); 1128 if (rest) 1129 memset(bh->b_data + size, 0, rest); 1130 set_buffer_uptodate(bh); 1131 unlock_buffer(bh); 1132 err = ext4_handle_dirty_metadata(handle, NULL, bh); 1133 if (unlikely(err)) 1134 ext4_std_error(sb, err); 1135 brelse(bh); 1136 1137 if (meta_bg == 0) 1138 group = ext4_list_backups(sb, &three, &five, &seven); 1139 else if (group == last) 1140 break; 1141 else 1142 group = last; 1143 } 1144 if ((err2 = ext4_journal_stop(handle)) && !err) 1145 err = err2; 1146 1147 /* 1148 * Ugh! Need to have e2fsck write the backup copies. It is too 1149 * late to revert the resize, we shouldn't fail just because of 1150 * the backup copies (they are only needed in case of corruption). 1151 * 1152 * However, if we got here we have a journal problem too, so we 1153 * can't really start a transaction to mark the superblock. 1154 * Chicken out and just set the flag on the hope it will be written 1155 * to disk, and if not - we will simply wait until next fsck. 1156 */ 1157 exit_err: 1158 if (err) { 1159 ext4_warning(sb, "can't update backup for group %u (err %d), " 1160 "forcing fsck on next reboot", group, err); 1161 sbi->s_mount_state &= ~EXT4_VALID_FS; 1162 sbi->s_es->s_state &= cpu_to_le16(~EXT4_VALID_FS); 1163 mark_buffer_dirty(sbi->s_sbh); 1164 } 1165 } 1166 1167 /* 1168 * ext4_add_new_descs() adds @count group descriptor of groups 1169 * starting at @group 1170 * 1171 * @handle: journal handle 1172 * @sb: super block 1173 * @group: the group no. of the first group desc to be added 1174 * @resize_inode: the resize inode 1175 * @count: number of group descriptors to be added 1176 */ 1177 static int ext4_add_new_descs(handle_t *handle, struct super_block *sb, 1178 ext4_group_t group, struct inode *resize_inode, 1179 ext4_group_t count) 1180 { 1181 struct ext4_sb_info *sbi = EXT4_SB(sb); 1182 struct ext4_super_block *es = sbi->s_es; 1183 struct buffer_head *gdb_bh; 1184 int i, gdb_off, gdb_num, err = 0; 1185 int meta_bg; 1186 1187 meta_bg = ext4_has_feature_meta_bg(sb); 1188 for (i = 0; i < count; i++, group++) { 1189 int reserved_gdb = ext4_bg_has_super(sb, group) ? 1190 le16_to_cpu(es->s_reserved_gdt_blocks) : 0; 1191 1192 gdb_off = group % EXT4_DESC_PER_BLOCK(sb); 1193 gdb_num = group / EXT4_DESC_PER_BLOCK(sb); 1194 1195 /* 1196 * We will only either add reserved group blocks to a backup group 1197 * or remove reserved blocks for the first group in a new group block. 1198 * Doing both would be mean more complex code, and sane people don't 1199 * use non-sparse filesystems anymore. This is already checked above. 1200 */ 1201 if (gdb_off) { 1202 gdb_bh = sbi->s_group_desc[gdb_num]; 1203 BUFFER_TRACE(gdb_bh, "get_write_access"); 1204 err = ext4_journal_get_write_access(handle, gdb_bh); 1205 1206 if (!err && reserved_gdb && ext4_bg_num_gdb(sb, group)) 1207 err = reserve_backup_gdb(handle, resize_inode, group); 1208 } else if (meta_bg != 0) { 1209 err = add_new_gdb_meta_bg(sb, handle, group); 1210 } else { 1211 err = add_new_gdb(handle, resize_inode, group); 1212 } 1213 if (err) 1214 break; 1215 } 1216 return err; 1217 } 1218 1219 static struct buffer_head *ext4_get_bitmap(struct super_block *sb, __u64 block) 1220 { 1221 struct buffer_head *bh = sb_getblk(sb, block); 1222 if (unlikely(!bh)) 1223 return NULL; 1224 if (!bh_uptodate_or_lock(bh)) { 1225 if (bh_submit_read(bh) < 0) { 1226 brelse(bh); 1227 return NULL; 1228 } 1229 } 1230 1231 return bh; 1232 } 1233 1234 static int ext4_set_bitmap_checksums(struct super_block *sb, 1235 ext4_group_t group, 1236 struct ext4_group_desc *gdp, 1237 struct ext4_new_group_data *group_data) 1238 { 1239 struct buffer_head *bh; 1240 1241 if (!ext4_has_metadata_csum(sb)) 1242 return 0; 1243 1244 bh = ext4_get_bitmap(sb, group_data->inode_bitmap); 1245 if (!bh) 1246 return -EIO; 1247 ext4_inode_bitmap_csum_set(sb, group, gdp, bh, 1248 EXT4_INODES_PER_GROUP(sb) / 8); 1249 brelse(bh); 1250 1251 bh = ext4_get_bitmap(sb, group_data->block_bitmap); 1252 if (!bh) 1253 return -EIO; 1254 ext4_block_bitmap_csum_set(sb, group, gdp, bh); 1255 brelse(bh); 1256 1257 return 0; 1258 } 1259 1260 /* 1261 * ext4_setup_new_descs() will set up the group descriptor descriptors of a flex bg 1262 */ 1263 static int ext4_setup_new_descs(handle_t *handle, struct super_block *sb, 1264 struct ext4_new_flex_group_data *flex_gd) 1265 { 1266 struct ext4_new_group_data *group_data = flex_gd->groups; 1267 struct ext4_group_desc *gdp; 1268 struct ext4_sb_info *sbi = EXT4_SB(sb); 1269 struct buffer_head *gdb_bh; 1270 ext4_group_t group; 1271 __u16 *bg_flags = flex_gd->bg_flags; 1272 int i, gdb_off, gdb_num, err = 0; 1273 1274 1275 for (i = 0; i < flex_gd->count; i++, group_data++, bg_flags++) { 1276 group = group_data->group; 1277 1278 gdb_off = group % EXT4_DESC_PER_BLOCK(sb); 1279 gdb_num = group / EXT4_DESC_PER_BLOCK(sb); 1280 1281 /* 1282 * get_write_access() has been called on gdb_bh by ext4_add_new_desc(). 1283 */ 1284 gdb_bh = sbi->s_group_desc[gdb_num]; 1285 /* Update group descriptor block for new group */ 1286 gdp = (struct ext4_group_desc *)(gdb_bh->b_data + 1287 gdb_off * EXT4_DESC_SIZE(sb)); 1288 1289 memset(gdp, 0, EXT4_DESC_SIZE(sb)); 1290 ext4_block_bitmap_set(sb, gdp, group_data->block_bitmap); 1291 ext4_inode_bitmap_set(sb, gdp, group_data->inode_bitmap); 1292 err = ext4_set_bitmap_checksums(sb, group, gdp, group_data); 1293 if (err) { 1294 ext4_std_error(sb, err); 1295 break; 1296 } 1297 1298 ext4_inode_table_set(sb, gdp, group_data->inode_table); 1299 ext4_free_group_clusters_set(sb, gdp, 1300 group_data->free_clusters_count); 1301 ext4_free_inodes_set(sb, gdp, EXT4_INODES_PER_GROUP(sb)); 1302 if (ext4_has_group_desc_csum(sb)) 1303 ext4_itable_unused_set(sb, gdp, 1304 EXT4_INODES_PER_GROUP(sb)); 1305 gdp->bg_flags = cpu_to_le16(*bg_flags); 1306 ext4_group_desc_csum_set(sb, group, gdp); 1307 1308 err = ext4_handle_dirty_metadata(handle, NULL, gdb_bh); 1309 if (unlikely(err)) { 1310 ext4_std_error(sb, err); 1311 break; 1312 } 1313 1314 /* 1315 * We can allocate memory for mb_alloc based on the new group 1316 * descriptor 1317 */ 1318 err = ext4_mb_add_groupinfo(sb, group, gdp); 1319 if (err) 1320 break; 1321 } 1322 return err; 1323 } 1324 1325 /* 1326 * ext4_update_super() updates the super block so that the newly added 1327 * groups can be seen by the filesystem. 1328 * 1329 * @sb: super block 1330 * @flex_gd: new added groups 1331 */ 1332 static void ext4_update_super(struct super_block *sb, 1333 struct ext4_new_flex_group_data *flex_gd) 1334 { 1335 ext4_fsblk_t blocks_count = 0; 1336 ext4_fsblk_t free_blocks = 0; 1337 ext4_fsblk_t reserved_blocks = 0; 1338 struct ext4_new_group_data *group_data = flex_gd->groups; 1339 struct ext4_sb_info *sbi = EXT4_SB(sb); 1340 struct ext4_super_block *es = sbi->s_es; 1341 int i; 1342 1343 BUG_ON(flex_gd->count == 0 || group_data == NULL); 1344 /* 1345 * Make the new blocks and inodes valid next. We do this before 1346 * increasing the group count so that once the group is enabled, 1347 * all of its blocks and inodes are already valid. 1348 * 1349 * We always allocate group-by-group, then block-by-block or 1350 * inode-by-inode within a group, so enabling these 1351 * blocks/inodes before the group is live won't actually let us 1352 * allocate the new space yet. 1353 */ 1354 for (i = 0; i < flex_gd->count; i++) { 1355 blocks_count += group_data[i].blocks_count; 1356 free_blocks += EXT4_C2B(sbi, group_data[i].free_clusters_count); 1357 } 1358 1359 reserved_blocks = ext4_r_blocks_count(es) * 100; 1360 reserved_blocks = div64_u64(reserved_blocks, ext4_blocks_count(es)); 1361 reserved_blocks *= blocks_count; 1362 do_div(reserved_blocks, 100); 1363 1364 ext4_blocks_count_set(es, ext4_blocks_count(es) + blocks_count); 1365 ext4_free_blocks_count_set(es, ext4_free_blocks_count(es) + free_blocks); 1366 le32_add_cpu(&es->s_inodes_count, EXT4_INODES_PER_GROUP(sb) * 1367 flex_gd->count); 1368 le32_add_cpu(&es->s_free_inodes_count, EXT4_INODES_PER_GROUP(sb) * 1369 flex_gd->count); 1370 1371 ext4_debug("free blocks count %llu", ext4_free_blocks_count(es)); 1372 /* 1373 * We need to protect s_groups_count against other CPUs seeing 1374 * inconsistent state in the superblock. 1375 * 1376 * The precise rules we use are: 1377 * 1378 * * Writers must perform a smp_wmb() after updating all 1379 * dependent data and before modifying the groups count 1380 * 1381 * * Readers must perform an smp_rmb() after reading the groups 1382 * count and before reading any dependent data. 1383 * 1384 * NB. These rules can be relaxed when checking the group count 1385 * while freeing data, as we can only allocate from a block 1386 * group after serialising against the group count, and we can 1387 * only then free after serialising in turn against that 1388 * allocation. 1389 */ 1390 smp_wmb(); 1391 1392 /* Update the global fs size fields */ 1393 sbi->s_groups_count += flex_gd->count; 1394 sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count, 1395 (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb))); 1396 1397 /* Update the reserved block counts only once the new group is 1398 * active. */ 1399 ext4_r_blocks_count_set(es, ext4_r_blocks_count(es) + 1400 reserved_blocks); 1401 1402 /* Update the free space counts */ 1403 percpu_counter_add(&sbi->s_freeclusters_counter, 1404 EXT4_NUM_B2C(sbi, free_blocks)); 1405 percpu_counter_add(&sbi->s_freeinodes_counter, 1406 EXT4_INODES_PER_GROUP(sb) * flex_gd->count); 1407 1408 ext4_debug("free blocks count %llu", 1409 percpu_counter_read(&sbi->s_freeclusters_counter)); 1410 if (ext4_has_feature_flex_bg(sb) && sbi->s_log_groups_per_flex) { 1411 ext4_group_t flex_group; 1412 flex_group = ext4_flex_group(sbi, group_data[0].group); 1413 atomic64_add(EXT4_NUM_B2C(sbi, free_blocks), 1414 &sbi->s_flex_groups[flex_group].free_clusters); 1415 atomic_add(EXT4_INODES_PER_GROUP(sb) * flex_gd->count, 1416 &sbi->s_flex_groups[flex_group].free_inodes); 1417 } 1418 1419 /* 1420 * Update the fs overhead information 1421 */ 1422 ext4_calculate_overhead(sb); 1423 1424 if (test_opt(sb, DEBUG)) 1425 printk(KERN_DEBUG "EXT4-fs: added group %u:" 1426 "%llu blocks(%llu free %llu reserved)\n", flex_gd->count, 1427 blocks_count, free_blocks, reserved_blocks); 1428 } 1429 1430 /* Add a flex group to an fs. Ensure we handle all possible error conditions 1431 * _before_ we start modifying the filesystem, because we cannot abort the 1432 * transaction and not have it write the data to disk. 1433 */ 1434 static int ext4_flex_group_add(struct super_block *sb, 1435 struct inode *resize_inode, 1436 struct ext4_new_flex_group_data *flex_gd) 1437 { 1438 struct ext4_sb_info *sbi = EXT4_SB(sb); 1439 struct ext4_super_block *es = sbi->s_es; 1440 ext4_fsblk_t o_blocks_count; 1441 ext4_grpblk_t last; 1442 ext4_group_t group; 1443 handle_t *handle; 1444 unsigned reserved_gdb; 1445 int err = 0, err2 = 0, credit; 1446 1447 BUG_ON(!flex_gd->count || !flex_gd->groups || !flex_gd->bg_flags); 1448 1449 reserved_gdb = le16_to_cpu(es->s_reserved_gdt_blocks); 1450 o_blocks_count = ext4_blocks_count(es); 1451 ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last); 1452 BUG_ON(last); 1453 1454 err = setup_new_flex_group_blocks(sb, flex_gd); 1455 if (err) 1456 goto exit; 1457 /* 1458 * We will always be modifying at least the superblock and GDT 1459 * blocks. If we are adding a group past the last current GDT block, 1460 * we will also modify the inode and the dindirect block. If we 1461 * are adding a group with superblock/GDT backups we will also 1462 * modify each of the reserved GDT dindirect blocks. 1463 */ 1464 credit = 3; /* sb, resize inode, resize inode dindirect */ 1465 /* GDT blocks */ 1466 credit += 1 + DIV_ROUND_UP(flex_gd->count, EXT4_DESC_PER_BLOCK(sb)); 1467 credit += reserved_gdb; /* Reserved GDT dindirect blocks */ 1468 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, credit); 1469 if (IS_ERR(handle)) { 1470 err = PTR_ERR(handle); 1471 goto exit; 1472 } 1473 1474 BUFFER_TRACE(sbi->s_sbh, "get_write_access"); 1475 err = ext4_journal_get_write_access(handle, sbi->s_sbh); 1476 if (err) 1477 goto exit_journal; 1478 1479 group = flex_gd->groups[0].group; 1480 BUG_ON(group != sbi->s_groups_count); 1481 err = ext4_add_new_descs(handle, sb, group, 1482 resize_inode, flex_gd->count); 1483 if (err) 1484 goto exit_journal; 1485 1486 err = ext4_setup_new_descs(handle, sb, flex_gd); 1487 if (err) 1488 goto exit_journal; 1489 1490 ext4_update_super(sb, flex_gd); 1491 1492 err = ext4_handle_dirty_super(handle, sb); 1493 1494 exit_journal: 1495 err2 = ext4_journal_stop(handle); 1496 if (!err) 1497 err = err2; 1498 1499 if (!err) { 1500 int gdb_num = group / EXT4_DESC_PER_BLOCK(sb); 1501 int gdb_num_end = ((group + flex_gd->count - 1) / 1502 EXT4_DESC_PER_BLOCK(sb)); 1503 int meta_bg = ext4_has_feature_meta_bg(sb); 1504 sector_t old_gdb = 0; 1505 1506 update_backups(sb, sbi->s_sbh->b_blocknr, (char *)es, 1507 sizeof(struct ext4_super_block), 0); 1508 for (; gdb_num <= gdb_num_end; gdb_num++) { 1509 struct buffer_head *gdb_bh; 1510 1511 gdb_bh = sbi->s_group_desc[gdb_num]; 1512 if (old_gdb == gdb_bh->b_blocknr) 1513 continue; 1514 update_backups(sb, gdb_bh->b_blocknr, gdb_bh->b_data, 1515 gdb_bh->b_size, meta_bg); 1516 old_gdb = gdb_bh->b_blocknr; 1517 } 1518 } 1519 exit: 1520 return err; 1521 } 1522 1523 static int ext4_setup_next_flex_gd(struct super_block *sb, 1524 struct ext4_new_flex_group_data *flex_gd, 1525 ext4_fsblk_t n_blocks_count, 1526 unsigned long flexbg_size) 1527 { 1528 struct ext4_sb_info *sbi = EXT4_SB(sb); 1529 struct ext4_super_block *es = sbi->s_es; 1530 struct ext4_new_group_data *group_data = flex_gd->groups; 1531 ext4_fsblk_t o_blocks_count; 1532 ext4_group_t n_group; 1533 ext4_group_t group; 1534 ext4_group_t last_group; 1535 ext4_grpblk_t last; 1536 ext4_grpblk_t clusters_per_group; 1537 unsigned long i; 1538 1539 clusters_per_group = EXT4_CLUSTERS_PER_GROUP(sb); 1540 1541 o_blocks_count = ext4_blocks_count(es); 1542 1543 if (o_blocks_count == n_blocks_count) 1544 return 0; 1545 1546 ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last); 1547 BUG_ON(last); 1548 ext4_get_group_no_and_offset(sb, n_blocks_count - 1, &n_group, &last); 1549 1550 last_group = group | (flexbg_size - 1); 1551 if (last_group > n_group) 1552 last_group = n_group; 1553 1554 flex_gd->count = last_group - group + 1; 1555 1556 for (i = 0; i < flex_gd->count; i++) { 1557 int overhead; 1558 1559 group_data[i].group = group + i; 1560 group_data[i].blocks_count = EXT4_BLOCKS_PER_GROUP(sb); 1561 overhead = ext4_group_overhead_blocks(sb, group + i); 1562 group_data[i].mdata_blocks = overhead; 1563 group_data[i].free_clusters_count = EXT4_CLUSTERS_PER_GROUP(sb); 1564 if (ext4_has_group_desc_csum(sb)) { 1565 flex_gd->bg_flags[i] = EXT4_BG_BLOCK_UNINIT | 1566 EXT4_BG_INODE_UNINIT; 1567 if (!test_opt(sb, INIT_INODE_TABLE)) 1568 flex_gd->bg_flags[i] |= EXT4_BG_INODE_ZEROED; 1569 } else 1570 flex_gd->bg_flags[i] = EXT4_BG_INODE_ZEROED; 1571 } 1572 1573 if (last_group == n_group && ext4_has_group_desc_csum(sb)) 1574 /* We need to initialize block bitmap of last group. */ 1575 flex_gd->bg_flags[i - 1] &= ~EXT4_BG_BLOCK_UNINIT; 1576 1577 if ((last_group == n_group) && (last != clusters_per_group - 1)) { 1578 group_data[i - 1].blocks_count = EXT4_C2B(sbi, last + 1); 1579 group_data[i - 1].free_clusters_count -= clusters_per_group - 1580 last - 1; 1581 } 1582 1583 return 1; 1584 } 1585 1586 /* Add group descriptor data to an existing or new group descriptor block. 1587 * Ensure we handle all possible error conditions _before_ we start modifying 1588 * the filesystem, because we cannot abort the transaction and not have it 1589 * write the data to disk. 1590 * 1591 * If we are on a GDT block boundary, we need to get the reserved GDT block. 1592 * Otherwise, we may need to add backup GDT blocks for a sparse group. 1593 * 1594 * We only need to hold the superblock lock while we are actually adding 1595 * in the new group's counts to the superblock. Prior to that we have 1596 * not really "added" the group at all. We re-check that we are still 1597 * adding in the last group in case things have changed since verifying. 1598 */ 1599 int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input) 1600 { 1601 struct ext4_new_flex_group_data flex_gd; 1602 struct ext4_sb_info *sbi = EXT4_SB(sb); 1603 struct ext4_super_block *es = sbi->s_es; 1604 int reserved_gdb = ext4_bg_has_super(sb, input->group) ? 1605 le16_to_cpu(es->s_reserved_gdt_blocks) : 0; 1606 struct inode *inode = NULL; 1607 int gdb_off; 1608 int err; 1609 __u16 bg_flags = 0; 1610 1611 gdb_off = input->group % EXT4_DESC_PER_BLOCK(sb); 1612 1613 if (gdb_off == 0 && !ext4_has_feature_sparse_super(sb)) { 1614 ext4_warning(sb, "Can't resize non-sparse filesystem further"); 1615 return -EPERM; 1616 } 1617 1618 if (ext4_blocks_count(es) + input->blocks_count < 1619 ext4_blocks_count(es)) { 1620 ext4_warning(sb, "blocks_count overflow"); 1621 return -EINVAL; 1622 } 1623 1624 if (le32_to_cpu(es->s_inodes_count) + EXT4_INODES_PER_GROUP(sb) < 1625 le32_to_cpu(es->s_inodes_count)) { 1626 ext4_warning(sb, "inodes_count overflow"); 1627 return -EINVAL; 1628 } 1629 1630 if (reserved_gdb || gdb_off == 0) { 1631 if (ext4_has_feature_resize_inode(sb) || 1632 !le16_to_cpu(es->s_reserved_gdt_blocks)) { 1633 ext4_warning(sb, 1634 "No reserved GDT blocks, can't resize"); 1635 return -EPERM; 1636 } 1637 inode = ext4_iget(sb, EXT4_RESIZE_INO); 1638 if (IS_ERR(inode)) { 1639 ext4_warning(sb, "Error opening resize inode"); 1640 return PTR_ERR(inode); 1641 } 1642 } 1643 1644 1645 err = verify_group_input(sb, input); 1646 if (err) 1647 goto out; 1648 1649 err = ext4_alloc_flex_bg_array(sb, input->group + 1); 1650 if (err) 1651 goto out; 1652 1653 err = ext4_mb_alloc_groupinfo(sb, input->group + 1); 1654 if (err) 1655 goto out; 1656 1657 flex_gd.count = 1; 1658 flex_gd.groups = input; 1659 flex_gd.bg_flags = &bg_flags; 1660 err = ext4_flex_group_add(sb, inode, &flex_gd); 1661 out: 1662 iput(inode); 1663 return err; 1664 } /* ext4_group_add */ 1665 1666 /* 1667 * extend a group without checking assuming that checking has been done. 1668 */ 1669 static int ext4_group_extend_no_check(struct super_block *sb, 1670 ext4_fsblk_t o_blocks_count, ext4_grpblk_t add) 1671 { 1672 struct ext4_super_block *es = EXT4_SB(sb)->s_es; 1673 handle_t *handle; 1674 int err = 0, err2; 1675 1676 /* We will update the superblock, one block bitmap, and 1677 * one group descriptor via ext4_group_add_blocks(). 1678 */ 1679 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, 3); 1680 if (IS_ERR(handle)) { 1681 err = PTR_ERR(handle); 1682 ext4_warning(sb, "error %d on journal start", err); 1683 return err; 1684 } 1685 1686 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access"); 1687 err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh); 1688 if (err) { 1689 ext4_warning(sb, "error %d on journal write access", err); 1690 goto errout; 1691 } 1692 1693 ext4_blocks_count_set(es, o_blocks_count + add); 1694 ext4_free_blocks_count_set(es, ext4_free_blocks_count(es) + add); 1695 ext4_debug("freeing blocks %llu through %llu\n", o_blocks_count, 1696 o_blocks_count + add); 1697 /* We add the blocks to the bitmap and set the group need init bit */ 1698 err = ext4_group_add_blocks(handle, sb, o_blocks_count, add); 1699 if (err) 1700 goto errout; 1701 ext4_handle_dirty_super(handle, sb); 1702 ext4_debug("freed blocks %llu through %llu\n", o_blocks_count, 1703 o_blocks_count + add); 1704 errout: 1705 err2 = ext4_journal_stop(handle); 1706 if (err2 && !err) 1707 err = err2; 1708 1709 if (!err) { 1710 if (test_opt(sb, DEBUG)) 1711 printk(KERN_DEBUG "EXT4-fs: extended group to %llu " 1712 "blocks\n", ext4_blocks_count(es)); 1713 update_backups(sb, EXT4_SB(sb)->s_sbh->b_blocknr, 1714 (char *)es, sizeof(struct ext4_super_block), 0); 1715 } 1716 return err; 1717 } 1718 1719 /* 1720 * Extend the filesystem to the new number of blocks specified. This entry 1721 * point is only used to extend the current filesystem to the end of the last 1722 * existing group. It can be accessed via ioctl, or by "remount,resize=<size>" 1723 * for emergencies (because it has no dependencies on reserved blocks). 1724 * 1725 * If we _really_ wanted, we could use default values to call ext4_group_add() 1726 * allow the "remount" trick to work for arbitrary resizing, assuming enough 1727 * GDT blocks are reserved to grow to the desired size. 1728 */ 1729 int ext4_group_extend(struct super_block *sb, struct ext4_super_block *es, 1730 ext4_fsblk_t n_blocks_count) 1731 { 1732 ext4_fsblk_t o_blocks_count; 1733 ext4_grpblk_t last; 1734 ext4_grpblk_t add; 1735 struct buffer_head *bh; 1736 int err; 1737 ext4_group_t group; 1738 1739 o_blocks_count = ext4_blocks_count(es); 1740 1741 if (test_opt(sb, DEBUG)) 1742 ext4_msg(sb, KERN_DEBUG, 1743 "extending last group from %llu to %llu blocks", 1744 o_blocks_count, n_blocks_count); 1745 1746 if (n_blocks_count == 0 || n_blocks_count == o_blocks_count) 1747 return 0; 1748 1749 if (n_blocks_count > (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) { 1750 ext4_msg(sb, KERN_ERR, 1751 "filesystem too large to resize to %llu blocks safely", 1752 n_blocks_count); 1753 if (sizeof(sector_t) < 8) 1754 ext4_warning(sb, "CONFIG_LBDAF not enabled"); 1755 return -EINVAL; 1756 } 1757 1758 if (n_blocks_count < o_blocks_count) { 1759 ext4_warning(sb, "can't shrink FS - resize aborted"); 1760 return -EINVAL; 1761 } 1762 1763 /* Handle the remaining blocks in the last group only. */ 1764 ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last); 1765 1766 if (last == 0) { 1767 ext4_warning(sb, "need to use ext2online to resize further"); 1768 return -EPERM; 1769 } 1770 1771 add = EXT4_BLOCKS_PER_GROUP(sb) - last; 1772 1773 if (o_blocks_count + add < o_blocks_count) { 1774 ext4_warning(sb, "blocks_count overflow"); 1775 return -EINVAL; 1776 } 1777 1778 if (o_blocks_count + add > n_blocks_count) 1779 add = n_blocks_count - o_blocks_count; 1780 1781 if (o_blocks_count + add < n_blocks_count) 1782 ext4_warning(sb, "will only finish group (%llu blocks, %u new)", 1783 o_blocks_count + add, add); 1784 1785 /* See if the device is actually as big as what was requested */ 1786 bh = sb_bread(sb, o_blocks_count + add - 1); 1787 if (!bh) { 1788 ext4_warning(sb, "can't read last block, resize aborted"); 1789 return -ENOSPC; 1790 } 1791 brelse(bh); 1792 1793 err = ext4_group_extend_no_check(sb, o_blocks_count, add); 1794 return err; 1795 } /* ext4_group_extend */ 1796 1797 1798 static int num_desc_blocks(struct super_block *sb, ext4_group_t groups) 1799 { 1800 return (groups + EXT4_DESC_PER_BLOCK(sb) - 1) / EXT4_DESC_PER_BLOCK(sb); 1801 } 1802 1803 /* 1804 * Release the resize inode and drop the resize_inode feature if there 1805 * are no more reserved gdt blocks, and then convert the file system 1806 * to enable meta_bg 1807 */ 1808 static int ext4_convert_meta_bg(struct super_block *sb, struct inode *inode) 1809 { 1810 handle_t *handle; 1811 struct ext4_sb_info *sbi = EXT4_SB(sb); 1812 struct ext4_super_block *es = sbi->s_es; 1813 struct ext4_inode_info *ei = EXT4_I(inode); 1814 ext4_fsblk_t nr; 1815 int i, ret, err = 0; 1816 int credits = 1; 1817 1818 ext4_msg(sb, KERN_INFO, "Converting file system to meta_bg"); 1819 if (inode) { 1820 if (es->s_reserved_gdt_blocks) { 1821 ext4_error(sb, "Unexpected non-zero " 1822 "s_reserved_gdt_blocks"); 1823 return -EPERM; 1824 } 1825 1826 /* Do a quick sanity check of the resize inode */ 1827 if (inode->i_blocks != 1 << (inode->i_blkbits - 1828 (9 - sbi->s_cluster_bits))) 1829 goto invalid_resize_inode; 1830 for (i = 0; i < EXT4_N_BLOCKS; i++) { 1831 if (i == EXT4_DIND_BLOCK) { 1832 if (ei->i_data[i]) 1833 continue; 1834 else 1835 goto invalid_resize_inode; 1836 } 1837 if (ei->i_data[i]) 1838 goto invalid_resize_inode; 1839 } 1840 credits += 3; /* block bitmap, bg descriptor, resize inode */ 1841 } 1842 1843 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, credits); 1844 if (IS_ERR(handle)) 1845 return PTR_ERR(handle); 1846 1847 BUFFER_TRACE(sbi->s_sbh, "get_write_access"); 1848 err = ext4_journal_get_write_access(handle, sbi->s_sbh); 1849 if (err) 1850 goto errout; 1851 1852 ext4_clear_feature_resize_inode(sb); 1853 ext4_set_feature_meta_bg(sb); 1854 sbi->s_es->s_first_meta_bg = 1855 cpu_to_le32(num_desc_blocks(sb, sbi->s_groups_count)); 1856 1857 err = ext4_handle_dirty_super(handle, sb); 1858 if (err) { 1859 ext4_std_error(sb, err); 1860 goto errout; 1861 } 1862 1863 if (inode) { 1864 nr = le32_to_cpu(ei->i_data[EXT4_DIND_BLOCK]); 1865 ext4_free_blocks(handle, inode, NULL, nr, 1, 1866 EXT4_FREE_BLOCKS_METADATA | 1867 EXT4_FREE_BLOCKS_FORGET); 1868 ei->i_data[EXT4_DIND_BLOCK] = 0; 1869 inode->i_blocks = 0; 1870 1871 err = ext4_mark_inode_dirty(handle, inode); 1872 if (err) 1873 ext4_std_error(sb, err); 1874 } 1875 1876 errout: 1877 ret = ext4_journal_stop(handle); 1878 if (!err) 1879 err = ret; 1880 return ret; 1881 1882 invalid_resize_inode: 1883 ext4_error(sb, "corrupted/inconsistent resize inode"); 1884 return -EINVAL; 1885 } 1886 1887 /* 1888 * ext4_resize_fs() resizes a fs to new size specified by @n_blocks_count 1889 * 1890 * @sb: super block of the fs to be resized 1891 * @n_blocks_count: the number of blocks resides in the resized fs 1892 */ 1893 int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count) 1894 { 1895 struct ext4_new_flex_group_data *flex_gd = NULL; 1896 struct ext4_sb_info *sbi = EXT4_SB(sb); 1897 struct ext4_super_block *es = sbi->s_es; 1898 struct buffer_head *bh; 1899 struct inode *resize_inode = NULL; 1900 ext4_grpblk_t add, offset; 1901 unsigned long n_desc_blocks; 1902 unsigned long o_desc_blocks; 1903 ext4_group_t o_group; 1904 ext4_group_t n_group; 1905 ext4_fsblk_t o_blocks_count; 1906 ext4_fsblk_t n_blocks_count_retry = 0; 1907 unsigned long last_update_time = 0; 1908 int err = 0, flexbg_size = 1 << sbi->s_log_groups_per_flex; 1909 int meta_bg; 1910 1911 /* See if the device is actually as big as what was requested */ 1912 bh = sb_bread(sb, n_blocks_count - 1); 1913 if (!bh) { 1914 ext4_warning(sb, "can't read last block, resize aborted"); 1915 return -ENOSPC; 1916 } 1917 brelse(bh); 1918 1919 retry: 1920 o_blocks_count = ext4_blocks_count(es); 1921 1922 ext4_msg(sb, KERN_INFO, "resizing filesystem from %llu " 1923 "to %llu blocks", o_blocks_count, n_blocks_count); 1924 1925 if (n_blocks_count < o_blocks_count) { 1926 /* On-line shrinking not supported */ 1927 ext4_warning(sb, "can't shrink FS - resize aborted"); 1928 return -EINVAL; 1929 } 1930 1931 if (n_blocks_count == o_blocks_count) 1932 /* Nothing need to do */ 1933 return 0; 1934 1935 n_group = ext4_get_group_number(sb, n_blocks_count - 1); 1936 if (n_group >= (0xFFFFFFFFUL / EXT4_INODES_PER_GROUP(sb))) { 1937 ext4_warning(sb, "resize would cause inodes_count overflow"); 1938 return -EINVAL; 1939 } 1940 ext4_get_group_no_and_offset(sb, o_blocks_count - 1, &o_group, &offset); 1941 1942 n_desc_blocks = num_desc_blocks(sb, n_group + 1); 1943 o_desc_blocks = num_desc_blocks(sb, sbi->s_groups_count); 1944 1945 meta_bg = ext4_has_feature_meta_bg(sb); 1946 1947 if (ext4_has_feature_resize_inode(sb)) { 1948 if (meta_bg) { 1949 ext4_error(sb, "resize_inode and meta_bg enabled " 1950 "simultaneously"); 1951 return -EINVAL; 1952 } 1953 if (n_desc_blocks > o_desc_blocks + 1954 le16_to_cpu(es->s_reserved_gdt_blocks)) { 1955 n_blocks_count_retry = n_blocks_count; 1956 n_desc_blocks = o_desc_blocks + 1957 le16_to_cpu(es->s_reserved_gdt_blocks); 1958 n_group = n_desc_blocks * EXT4_DESC_PER_BLOCK(sb); 1959 n_blocks_count = (ext4_fsblk_t)n_group * 1960 EXT4_BLOCKS_PER_GROUP(sb); 1961 n_group--; /* set to last group number */ 1962 } 1963 1964 if (!resize_inode) 1965 resize_inode = ext4_iget(sb, EXT4_RESIZE_INO); 1966 if (IS_ERR(resize_inode)) { 1967 ext4_warning(sb, "Error opening resize inode"); 1968 return PTR_ERR(resize_inode); 1969 } 1970 } 1971 1972 if ((!resize_inode && !meta_bg) || n_blocks_count == o_blocks_count) { 1973 err = ext4_convert_meta_bg(sb, resize_inode); 1974 if (err) 1975 goto out; 1976 if (resize_inode) { 1977 iput(resize_inode); 1978 resize_inode = NULL; 1979 } 1980 if (n_blocks_count_retry) { 1981 n_blocks_count = n_blocks_count_retry; 1982 n_blocks_count_retry = 0; 1983 goto retry; 1984 } 1985 } 1986 1987 /* 1988 * Make sure the last group has enough space so that it's 1989 * guaranteed to have enough space for all metadata blocks 1990 * that it might need to hold. (We might not need to store 1991 * the inode table blocks in the last block group, but there 1992 * will be cases where this might be needed.) 1993 */ 1994 if ((ext4_group_first_block_no(sb, n_group) + 1995 ext4_group_overhead_blocks(sb, n_group) + 2 + 1996 sbi->s_itb_per_group + sbi->s_cluster_ratio) >= n_blocks_count) { 1997 n_blocks_count = ext4_group_first_block_no(sb, n_group); 1998 n_group--; 1999 n_blocks_count_retry = 0; 2000 if (resize_inode) { 2001 iput(resize_inode); 2002 resize_inode = NULL; 2003 } 2004 goto retry; 2005 } 2006 2007 /* extend the last group */ 2008 if (n_group == o_group) 2009 add = n_blocks_count - o_blocks_count; 2010 else 2011 add = EXT4_C2B(sbi, EXT4_CLUSTERS_PER_GROUP(sb) - (offset + 1)); 2012 if (add > 0) { 2013 err = ext4_group_extend_no_check(sb, o_blocks_count, add); 2014 if (err) 2015 goto out; 2016 } 2017 2018 if (ext4_blocks_count(es) == n_blocks_count) 2019 goto out; 2020 2021 err = ext4_alloc_flex_bg_array(sb, n_group + 1); 2022 if (err) 2023 return err; 2024 2025 err = ext4_mb_alloc_groupinfo(sb, n_group + 1); 2026 if (err) 2027 goto out; 2028 2029 flex_gd = alloc_flex_gd(flexbg_size); 2030 if (flex_gd == NULL) { 2031 err = -ENOMEM; 2032 goto out; 2033 } 2034 2035 /* Add flex groups. Note that a regular group is a 2036 * flex group with 1 group. 2037 */ 2038 while (ext4_setup_next_flex_gd(sb, flex_gd, n_blocks_count, 2039 flexbg_size)) { 2040 if (jiffies - last_update_time > HZ * 10) { 2041 if (last_update_time) 2042 ext4_msg(sb, KERN_INFO, 2043 "resized to %llu blocks", 2044 ext4_blocks_count(es)); 2045 last_update_time = jiffies; 2046 } 2047 if (ext4_alloc_group_tables(sb, flex_gd, flexbg_size) != 0) 2048 break; 2049 err = ext4_flex_group_add(sb, resize_inode, flex_gd); 2050 if (unlikely(err)) 2051 break; 2052 } 2053 2054 if (!err && n_blocks_count_retry) { 2055 n_blocks_count = n_blocks_count_retry; 2056 n_blocks_count_retry = 0; 2057 free_flex_gd(flex_gd); 2058 flex_gd = NULL; 2059 goto retry; 2060 } 2061 2062 out: 2063 if (flex_gd) 2064 free_flex_gd(flex_gd); 2065 if (resize_inode != NULL) 2066 iput(resize_inode); 2067 ext4_msg(sb, KERN_INFO, "resized filesystem to %llu", n_blocks_count); 2068 return err; 2069 } 2070