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 struct ext4_rcu_ptr { 21 struct rcu_head rcu; 22 void *ptr; 23 }; 24 25 static void ext4_rcu_ptr_callback(struct rcu_head *head) 26 { 27 struct ext4_rcu_ptr *ptr; 28 29 ptr = container_of(head, struct ext4_rcu_ptr, rcu); 30 kvfree(ptr->ptr); 31 kfree(ptr); 32 } 33 34 void ext4_kvfree_array_rcu(void *to_free) 35 { 36 struct ext4_rcu_ptr *ptr = kzalloc(sizeof(*ptr), GFP_KERNEL); 37 38 if (ptr) { 39 ptr->ptr = to_free; 40 call_rcu(&ptr->rcu, ext4_rcu_ptr_callback); 41 return; 42 } 43 synchronize_rcu(); 44 kvfree(to_free); 45 } 46 47 int ext4_resize_begin(struct super_block *sb) 48 { 49 struct ext4_sb_info *sbi = EXT4_SB(sb); 50 int ret = 0; 51 52 if (!capable(CAP_SYS_RESOURCE)) 53 return -EPERM; 54 55 /* 56 * If we are not using the primary superblock/GDT copy don't resize, 57 * because the user tools have no way of handling this. Probably a 58 * bad time to do it anyways. 59 */ 60 if (EXT4_B2C(sbi, sbi->s_sbh->b_blocknr) != 61 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block)) { 62 ext4_warning(sb, "won't resize using backup superblock at %llu", 63 (unsigned long long)EXT4_SB(sb)->s_sbh->b_blocknr); 64 return -EPERM; 65 } 66 67 /* 68 * We are not allowed to do online-resizing on a filesystem mounted 69 * with error, because it can destroy the filesystem easily. 70 */ 71 if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) { 72 ext4_warning(sb, "There are errors in the filesystem, " 73 "so online resizing is not allowed"); 74 return -EPERM; 75 } 76 77 if (ext4_has_feature_bigalloc(sb)) { 78 ext4_msg(sb, KERN_ERR, "Online resizing not supported with bigalloc"); 79 return -EOPNOTSUPP; 80 } 81 if (ext4_has_feature_sparse_super2(sb)) { 82 ext4_msg(sb, KERN_ERR, "Online resizing not supported with sparse_super2"); 83 return -EOPNOTSUPP; 84 } 85 86 if (test_and_set_bit_lock(EXT4_FLAGS_RESIZING, 87 &EXT4_SB(sb)->s_ext4_flags)) 88 ret = -EBUSY; 89 90 return ret; 91 } 92 93 void ext4_resize_end(struct super_block *sb) 94 { 95 clear_bit_unlock(EXT4_FLAGS_RESIZING, &EXT4_SB(sb)->s_ext4_flags); 96 smp_mb__after_atomic(); 97 } 98 99 static ext4_group_t ext4_meta_bg_first_group(struct super_block *sb, 100 ext4_group_t group) { 101 return (group >> EXT4_DESC_PER_BLOCK_BITS(sb)) << 102 EXT4_DESC_PER_BLOCK_BITS(sb); 103 } 104 105 static ext4_fsblk_t ext4_meta_bg_first_block_no(struct super_block *sb, 106 ext4_group_t group) { 107 group = ext4_meta_bg_first_group(sb, group); 108 return ext4_group_first_block_no(sb, group); 109 } 110 111 static ext4_grpblk_t ext4_group_overhead_blocks(struct super_block *sb, 112 ext4_group_t group) { 113 ext4_grpblk_t overhead; 114 overhead = ext4_bg_num_gdb(sb, group); 115 if (ext4_bg_has_super(sb, group)) 116 overhead += 1 + 117 le16_to_cpu(EXT4_SB(sb)->s_es->s_reserved_gdt_blocks); 118 return overhead; 119 } 120 121 #define outside(b, first, last) ((b) < (first) || (b) >= (last)) 122 #define inside(b, first, last) ((b) >= (first) && (b) < (last)) 123 124 static int verify_group_input(struct super_block *sb, 125 struct ext4_new_group_data *input) 126 { 127 struct ext4_sb_info *sbi = EXT4_SB(sb); 128 struct ext4_super_block *es = sbi->s_es; 129 ext4_fsblk_t start = ext4_blocks_count(es); 130 ext4_fsblk_t end = start + input->blocks_count; 131 ext4_group_t group = input->group; 132 ext4_fsblk_t itend = input->inode_table + sbi->s_itb_per_group; 133 unsigned overhead; 134 ext4_fsblk_t metaend; 135 struct buffer_head *bh = NULL; 136 ext4_grpblk_t free_blocks_count, offset; 137 int err = -EINVAL; 138 139 if (group != sbi->s_groups_count) { 140 ext4_warning(sb, "Cannot add at group %u (only %u groups)", 141 input->group, sbi->s_groups_count); 142 return -EINVAL; 143 } 144 145 overhead = ext4_group_overhead_blocks(sb, group); 146 metaend = start + overhead; 147 input->free_clusters_count = free_blocks_count = 148 input->blocks_count - 2 - overhead - sbi->s_itb_per_group; 149 150 if (test_opt(sb, DEBUG)) 151 printk(KERN_DEBUG "EXT4-fs: adding %s group %u: %u blocks " 152 "(%d free, %u reserved)\n", 153 ext4_bg_has_super(sb, input->group) ? "normal" : 154 "no-super", input->group, input->blocks_count, 155 free_blocks_count, input->reserved_blocks); 156 157 ext4_get_group_no_and_offset(sb, start, NULL, &offset); 158 if (offset != 0) 159 ext4_warning(sb, "Last group not full"); 160 else if (input->reserved_blocks > input->blocks_count / 5) 161 ext4_warning(sb, "Reserved blocks too high (%u)", 162 input->reserved_blocks); 163 else if (free_blocks_count < 0) 164 ext4_warning(sb, "Bad blocks count %u", 165 input->blocks_count); 166 else if (IS_ERR(bh = ext4_sb_bread(sb, end - 1, 0))) { 167 err = PTR_ERR(bh); 168 bh = NULL; 169 ext4_warning(sb, "Cannot read last block (%llu)", 170 end - 1); 171 } else if (outside(input->block_bitmap, start, end)) 172 ext4_warning(sb, "Block bitmap not in group (block %llu)", 173 (unsigned long long)input->block_bitmap); 174 else if (outside(input->inode_bitmap, start, end)) 175 ext4_warning(sb, "Inode bitmap not in group (block %llu)", 176 (unsigned long long)input->inode_bitmap); 177 else if (outside(input->inode_table, start, end) || 178 outside(itend - 1, start, end)) 179 ext4_warning(sb, "Inode table not in group (blocks %llu-%llu)", 180 (unsigned long long)input->inode_table, itend - 1); 181 else if (input->inode_bitmap == input->block_bitmap) 182 ext4_warning(sb, "Block bitmap same as inode bitmap (%llu)", 183 (unsigned long long)input->block_bitmap); 184 else if (inside(input->block_bitmap, input->inode_table, itend)) 185 ext4_warning(sb, "Block bitmap (%llu) in inode table " 186 "(%llu-%llu)", 187 (unsigned long long)input->block_bitmap, 188 (unsigned long long)input->inode_table, itend - 1); 189 else if (inside(input->inode_bitmap, input->inode_table, itend)) 190 ext4_warning(sb, "Inode bitmap (%llu) in inode table " 191 "(%llu-%llu)", 192 (unsigned long long)input->inode_bitmap, 193 (unsigned long long)input->inode_table, itend - 1); 194 else if (inside(input->block_bitmap, start, metaend)) 195 ext4_warning(sb, "Block bitmap (%llu) in GDT table (%llu-%llu)", 196 (unsigned long long)input->block_bitmap, 197 start, metaend - 1); 198 else if (inside(input->inode_bitmap, start, metaend)) 199 ext4_warning(sb, "Inode bitmap (%llu) in GDT table (%llu-%llu)", 200 (unsigned long long)input->inode_bitmap, 201 start, metaend - 1); 202 else if (inside(input->inode_table, start, metaend) || 203 inside(itend - 1, start, metaend)) 204 ext4_warning(sb, "Inode table (%llu-%llu) overlaps GDT table " 205 "(%llu-%llu)", 206 (unsigned long long)input->inode_table, 207 itend - 1, start, metaend - 1); 208 else 209 err = 0; 210 brelse(bh); 211 212 return err; 213 } 214 215 /* 216 * ext4_new_flex_group_data is used by 64bit-resize interface to add a flex 217 * group each time. 218 */ 219 struct ext4_new_flex_group_data { 220 struct ext4_new_group_data *groups; /* new_group_data for groups 221 in the flex group */ 222 __u16 *bg_flags; /* block group flags of groups 223 in @groups */ 224 ext4_group_t count; /* number of groups in @groups 225 */ 226 }; 227 228 /* 229 * alloc_flex_gd() allocates a ext4_new_flex_group_data with size of 230 * @flexbg_size. 231 * 232 * Returns NULL on failure otherwise address of the allocated structure. 233 */ 234 static struct ext4_new_flex_group_data *alloc_flex_gd(unsigned long flexbg_size) 235 { 236 struct ext4_new_flex_group_data *flex_gd; 237 238 flex_gd = kmalloc(sizeof(*flex_gd), GFP_NOFS); 239 if (flex_gd == NULL) 240 goto out3; 241 242 if (flexbg_size >= UINT_MAX / sizeof(struct ext4_new_group_data)) 243 goto out2; 244 flex_gd->count = flexbg_size; 245 246 flex_gd->groups = kmalloc_array(flexbg_size, 247 sizeof(struct ext4_new_group_data), 248 GFP_NOFS); 249 if (flex_gd->groups == NULL) 250 goto out2; 251 252 flex_gd->bg_flags = kmalloc_array(flexbg_size, sizeof(__u16), 253 GFP_NOFS); 254 if (flex_gd->bg_flags == NULL) 255 goto out1; 256 257 return flex_gd; 258 259 out1: 260 kfree(flex_gd->groups); 261 out2: 262 kfree(flex_gd); 263 out3: 264 return NULL; 265 } 266 267 static void free_flex_gd(struct ext4_new_flex_group_data *flex_gd) 268 { 269 kfree(flex_gd->bg_flags); 270 kfree(flex_gd->groups); 271 kfree(flex_gd); 272 } 273 274 /* 275 * ext4_alloc_group_tables() allocates block bitmaps, inode bitmaps 276 * and inode tables for a flex group. 277 * 278 * This function is used by 64bit-resize. Note that this function allocates 279 * group tables from the 1st group of groups contained by @flexgd, which may 280 * be a partial of a flex group. 281 * 282 * @sb: super block of fs to which the groups belongs 283 * 284 * Returns 0 on a successful allocation of the metadata blocks in the 285 * block group. 286 */ 287 static int ext4_alloc_group_tables(struct super_block *sb, 288 struct ext4_new_flex_group_data *flex_gd, 289 int flexbg_size) 290 { 291 struct ext4_new_group_data *group_data = flex_gd->groups; 292 ext4_fsblk_t start_blk; 293 ext4_fsblk_t last_blk; 294 ext4_group_t src_group; 295 ext4_group_t bb_index = 0; 296 ext4_group_t ib_index = 0; 297 ext4_group_t it_index = 0; 298 ext4_group_t group; 299 ext4_group_t last_group; 300 unsigned overhead; 301 __u16 uninit_mask = (flexbg_size > 1) ? ~EXT4_BG_BLOCK_UNINIT : ~0; 302 int i; 303 304 BUG_ON(flex_gd->count == 0 || group_data == NULL); 305 306 src_group = group_data[0].group; 307 last_group = src_group + flex_gd->count - 1; 308 309 BUG_ON((flexbg_size > 1) && ((src_group & ~(flexbg_size - 1)) != 310 (last_group & ~(flexbg_size - 1)))); 311 next_group: 312 group = group_data[0].group; 313 if (src_group >= group_data[0].group + flex_gd->count) 314 return -ENOSPC; 315 start_blk = ext4_group_first_block_no(sb, src_group); 316 last_blk = start_blk + group_data[src_group - group].blocks_count; 317 318 overhead = ext4_group_overhead_blocks(sb, src_group); 319 320 start_blk += overhead; 321 322 /* We collect contiguous blocks as much as possible. */ 323 src_group++; 324 for (; src_group <= last_group; src_group++) { 325 overhead = ext4_group_overhead_blocks(sb, src_group); 326 if (overhead == 0) 327 last_blk += group_data[src_group - group].blocks_count; 328 else 329 break; 330 } 331 332 /* Allocate block bitmaps */ 333 for (; bb_index < flex_gd->count; bb_index++) { 334 if (start_blk >= last_blk) 335 goto next_group; 336 group_data[bb_index].block_bitmap = start_blk++; 337 group = ext4_get_group_number(sb, start_blk - 1); 338 group -= group_data[0].group; 339 group_data[group].mdata_blocks++; 340 flex_gd->bg_flags[group] &= uninit_mask; 341 } 342 343 /* Allocate inode bitmaps */ 344 for (; ib_index < flex_gd->count; ib_index++) { 345 if (start_blk >= last_blk) 346 goto next_group; 347 group_data[ib_index].inode_bitmap = start_blk++; 348 group = ext4_get_group_number(sb, start_blk - 1); 349 group -= group_data[0].group; 350 group_data[group].mdata_blocks++; 351 flex_gd->bg_flags[group] &= uninit_mask; 352 } 353 354 /* Allocate inode tables */ 355 for (; it_index < flex_gd->count; it_index++) { 356 unsigned int itb = EXT4_SB(sb)->s_itb_per_group; 357 ext4_fsblk_t next_group_start; 358 359 if (start_blk + itb > last_blk) 360 goto next_group; 361 group_data[it_index].inode_table = start_blk; 362 group = ext4_get_group_number(sb, start_blk); 363 next_group_start = ext4_group_first_block_no(sb, group + 1); 364 group -= group_data[0].group; 365 366 if (start_blk + itb > next_group_start) { 367 flex_gd->bg_flags[group + 1] &= uninit_mask; 368 overhead = start_blk + itb - next_group_start; 369 group_data[group + 1].mdata_blocks += overhead; 370 itb -= overhead; 371 } 372 373 group_data[group].mdata_blocks += itb; 374 flex_gd->bg_flags[group] &= uninit_mask; 375 start_blk += EXT4_SB(sb)->s_itb_per_group; 376 } 377 378 /* Update free clusters count to exclude metadata blocks */ 379 for (i = 0; i < flex_gd->count; i++) { 380 group_data[i].free_clusters_count -= 381 EXT4_NUM_B2C(EXT4_SB(sb), 382 group_data[i].mdata_blocks); 383 } 384 385 if (test_opt(sb, DEBUG)) { 386 int i; 387 group = group_data[0].group; 388 389 printk(KERN_DEBUG "EXT4-fs: adding a flex group with " 390 "%d groups, flexbg size is %d:\n", flex_gd->count, 391 flexbg_size); 392 393 for (i = 0; i < flex_gd->count; i++) { 394 ext4_debug( 395 "adding %s group %u: %u blocks (%d free, %d mdata blocks)\n", 396 ext4_bg_has_super(sb, group + i) ? "normal" : 397 "no-super", group + i, 398 group_data[i].blocks_count, 399 group_data[i].free_clusters_count, 400 group_data[i].mdata_blocks); 401 } 402 } 403 return 0; 404 } 405 406 static struct buffer_head *bclean(handle_t *handle, struct super_block *sb, 407 ext4_fsblk_t blk) 408 { 409 struct buffer_head *bh; 410 int err; 411 412 bh = sb_getblk(sb, blk); 413 if (unlikely(!bh)) 414 return ERR_PTR(-ENOMEM); 415 BUFFER_TRACE(bh, "get_write_access"); 416 if ((err = ext4_journal_get_write_access(handle, bh))) { 417 brelse(bh); 418 bh = ERR_PTR(err); 419 } else { 420 memset(bh->b_data, 0, sb->s_blocksize); 421 set_buffer_uptodate(bh); 422 } 423 424 return bh; 425 } 426 427 static int ext4_resize_ensure_credits_batch(handle_t *handle, int credits) 428 { 429 return ext4_journal_ensure_credits_fn(handle, credits, 430 EXT4_MAX_TRANS_DATA, 0, 0); 431 } 432 433 /* 434 * set_flexbg_block_bitmap() mark clusters [@first_cluster, @last_cluster] used. 435 * 436 * Helper function for ext4_setup_new_group_blocks() which set . 437 * 438 * @sb: super block 439 * @handle: journal handle 440 * @flex_gd: flex group data 441 */ 442 static int set_flexbg_block_bitmap(struct super_block *sb, handle_t *handle, 443 struct ext4_new_flex_group_data *flex_gd, 444 ext4_fsblk_t first_cluster, ext4_fsblk_t last_cluster) 445 { 446 struct ext4_sb_info *sbi = EXT4_SB(sb); 447 ext4_group_t count = last_cluster - first_cluster + 1; 448 ext4_group_t count2; 449 450 ext4_debug("mark clusters [%llu-%llu] used\n", first_cluster, 451 last_cluster); 452 for (count2 = count; count > 0; 453 count -= count2, first_cluster += count2) { 454 ext4_fsblk_t start; 455 struct buffer_head *bh; 456 ext4_group_t group; 457 int err; 458 459 group = ext4_get_group_number(sb, EXT4_C2B(sbi, first_cluster)); 460 start = EXT4_B2C(sbi, ext4_group_first_block_no(sb, group)); 461 group -= flex_gd->groups[0].group; 462 463 count2 = EXT4_CLUSTERS_PER_GROUP(sb) - (first_cluster - start); 464 if (count2 > count) 465 count2 = count; 466 467 if (flex_gd->bg_flags[group] & EXT4_BG_BLOCK_UNINIT) { 468 BUG_ON(flex_gd->count > 1); 469 continue; 470 } 471 472 err = ext4_resize_ensure_credits_batch(handle, 1); 473 if (err < 0) 474 return err; 475 476 bh = sb_getblk(sb, flex_gd->groups[group].block_bitmap); 477 if (unlikely(!bh)) 478 return -ENOMEM; 479 480 BUFFER_TRACE(bh, "get_write_access"); 481 err = ext4_journal_get_write_access(handle, bh); 482 if (err) { 483 brelse(bh); 484 return err; 485 } 486 ext4_debug("mark block bitmap %#04llx (+%llu/%u)\n", 487 first_cluster, first_cluster - start, count2); 488 ext4_set_bits(bh->b_data, first_cluster - start, count2); 489 490 err = ext4_handle_dirty_metadata(handle, NULL, bh); 491 brelse(bh); 492 if (unlikely(err)) 493 return err; 494 } 495 496 return 0; 497 } 498 499 /* 500 * Set up the block and inode bitmaps, and the inode table for the new groups. 501 * This doesn't need to be part of the main transaction, since we are only 502 * changing blocks outside the actual filesystem. We still do journaling to 503 * ensure the recovery is correct in case of a failure just after resize. 504 * If any part of this fails, we simply abort the resize. 505 * 506 * setup_new_flex_group_blocks handles a flex group as follow: 507 * 1. copy super block and GDT, and initialize group tables if necessary. 508 * In this step, we only set bits in blocks bitmaps for blocks taken by 509 * super block and GDT. 510 * 2. allocate group tables in block bitmaps, that is, set bits in block 511 * bitmap for blocks taken by group tables. 512 */ 513 static int setup_new_flex_group_blocks(struct super_block *sb, 514 struct ext4_new_flex_group_data *flex_gd) 515 { 516 int group_table_count[] = {1, 1, EXT4_SB(sb)->s_itb_per_group}; 517 ext4_fsblk_t start; 518 ext4_fsblk_t block; 519 struct ext4_sb_info *sbi = EXT4_SB(sb); 520 struct ext4_super_block *es = sbi->s_es; 521 struct ext4_new_group_data *group_data = flex_gd->groups; 522 __u16 *bg_flags = flex_gd->bg_flags; 523 handle_t *handle; 524 ext4_group_t group, count; 525 struct buffer_head *bh = NULL; 526 int reserved_gdb, i, j, err = 0, err2; 527 int meta_bg; 528 529 BUG_ON(!flex_gd->count || !group_data || 530 group_data[0].group != sbi->s_groups_count); 531 532 reserved_gdb = le16_to_cpu(es->s_reserved_gdt_blocks); 533 meta_bg = ext4_has_feature_meta_bg(sb); 534 535 /* This transaction may be extended/restarted along the way */ 536 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, EXT4_MAX_TRANS_DATA); 537 if (IS_ERR(handle)) 538 return PTR_ERR(handle); 539 540 group = group_data[0].group; 541 for (i = 0; i < flex_gd->count; i++, group++) { 542 unsigned long gdblocks; 543 ext4_grpblk_t overhead; 544 545 gdblocks = ext4_bg_num_gdb(sb, group); 546 start = ext4_group_first_block_no(sb, group); 547 548 if (meta_bg == 0 && !ext4_bg_has_super(sb, group)) 549 goto handle_itb; 550 551 if (meta_bg == 1) { 552 ext4_group_t first_group; 553 first_group = ext4_meta_bg_first_group(sb, group); 554 if (first_group != group + 1 && 555 first_group != group + EXT4_DESC_PER_BLOCK(sb) - 1) 556 goto handle_itb; 557 } 558 559 block = start + ext4_bg_has_super(sb, group); 560 /* Copy all of the GDT blocks into the backup in this group */ 561 for (j = 0; j < gdblocks; j++, block++) { 562 struct buffer_head *gdb; 563 564 ext4_debug("update backup group %#04llx\n", block); 565 err = ext4_resize_ensure_credits_batch(handle, 1); 566 if (err < 0) 567 goto out; 568 569 gdb = sb_getblk(sb, block); 570 if (unlikely(!gdb)) { 571 err = -ENOMEM; 572 goto out; 573 } 574 575 BUFFER_TRACE(gdb, "get_write_access"); 576 err = ext4_journal_get_write_access(handle, gdb); 577 if (err) { 578 brelse(gdb); 579 goto out; 580 } 581 memcpy(gdb->b_data, sbi_array_rcu_deref(sbi, 582 s_group_desc, j)->b_data, gdb->b_size); 583 set_buffer_uptodate(gdb); 584 585 err = ext4_handle_dirty_metadata(handle, NULL, gdb); 586 if (unlikely(err)) { 587 brelse(gdb); 588 goto out; 589 } 590 brelse(gdb); 591 } 592 593 /* Zero out all of the reserved backup group descriptor 594 * table blocks 595 */ 596 if (ext4_bg_has_super(sb, group)) { 597 err = sb_issue_zeroout(sb, gdblocks + start + 1, 598 reserved_gdb, GFP_NOFS); 599 if (err) 600 goto out; 601 } 602 603 handle_itb: 604 /* Initialize group tables of the grop @group */ 605 if (!(bg_flags[i] & EXT4_BG_INODE_ZEROED)) 606 goto handle_bb; 607 608 /* Zero out all of the inode table blocks */ 609 block = group_data[i].inode_table; 610 ext4_debug("clear inode table blocks %#04llx -> %#04lx\n", 611 block, sbi->s_itb_per_group); 612 err = sb_issue_zeroout(sb, block, sbi->s_itb_per_group, 613 GFP_NOFS); 614 if (err) 615 goto out; 616 617 handle_bb: 618 if (bg_flags[i] & EXT4_BG_BLOCK_UNINIT) 619 goto handle_ib; 620 621 /* Initialize block bitmap of the @group */ 622 block = group_data[i].block_bitmap; 623 err = ext4_resize_ensure_credits_batch(handle, 1); 624 if (err < 0) 625 goto out; 626 627 bh = bclean(handle, sb, block); 628 if (IS_ERR(bh)) { 629 err = PTR_ERR(bh); 630 goto out; 631 } 632 overhead = ext4_group_overhead_blocks(sb, group); 633 if (overhead != 0) { 634 ext4_debug("mark backup superblock %#04llx (+0)\n", 635 start); 636 ext4_set_bits(bh->b_data, 0, 637 EXT4_NUM_B2C(sbi, overhead)); 638 } 639 ext4_mark_bitmap_end(EXT4_B2C(sbi, group_data[i].blocks_count), 640 sb->s_blocksize * 8, bh->b_data); 641 err = ext4_handle_dirty_metadata(handle, NULL, bh); 642 brelse(bh); 643 if (err) 644 goto out; 645 646 handle_ib: 647 if (bg_flags[i] & EXT4_BG_INODE_UNINIT) 648 continue; 649 650 /* Initialize inode bitmap of the @group */ 651 block = group_data[i].inode_bitmap; 652 err = ext4_resize_ensure_credits_batch(handle, 1); 653 if (err < 0) 654 goto out; 655 /* Mark unused entries in inode bitmap used */ 656 bh = bclean(handle, sb, block); 657 if (IS_ERR(bh)) { 658 err = PTR_ERR(bh); 659 goto out; 660 } 661 662 ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb), 663 sb->s_blocksize * 8, bh->b_data); 664 err = ext4_handle_dirty_metadata(handle, NULL, bh); 665 brelse(bh); 666 if (err) 667 goto out; 668 } 669 670 /* Mark group tables in block bitmap */ 671 for (j = 0; j < GROUP_TABLE_COUNT; j++) { 672 count = group_table_count[j]; 673 start = (&group_data[0].block_bitmap)[j]; 674 block = start; 675 for (i = 1; i < flex_gd->count; i++) { 676 block += group_table_count[j]; 677 if (block == (&group_data[i].block_bitmap)[j]) { 678 count += group_table_count[j]; 679 continue; 680 } 681 err = set_flexbg_block_bitmap(sb, handle, 682 flex_gd, 683 EXT4_B2C(sbi, start), 684 EXT4_B2C(sbi, 685 start + count 686 - 1)); 687 if (err) 688 goto out; 689 count = group_table_count[j]; 690 start = (&group_data[i].block_bitmap)[j]; 691 block = start; 692 } 693 694 if (count) { 695 err = set_flexbg_block_bitmap(sb, handle, 696 flex_gd, 697 EXT4_B2C(sbi, start), 698 EXT4_B2C(sbi, 699 start + count 700 - 1)); 701 if (err) 702 goto out; 703 } 704 } 705 706 out: 707 err2 = ext4_journal_stop(handle); 708 if (err2 && !err) 709 err = err2; 710 711 return err; 712 } 713 714 /* 715 * Iterate through the groups which hold BACKUP superblock/GDT copies in an 716 * ext4 filesystem. The counters should be initialized to 1, 5, and 7 before 717 * calling this for the first time. In a sparse filesystem it will be the 718 * sequence of powers of 3, 5, and 7: 1, 3, 5, 7, 9, 25, 27, 49, 81, ... 719 * For a non-sparse filesystem it will be every group: 1, 2, 3, 4, ... 720 */ 721 static unsigned ext4_list_backups(struct super_block *sb, unsigned *three, 722 unsigned *five, unsigned *seven) 723 { 724 unsigned *min = three; 725 int mult = 3; 726 unsigned ret; 727 728 if (!ext4_has_feature_sparse_super(sb)) { 729 ret = *min; 730 *min += 1; 731 return ret; 732 } 733 734 if (*five < *min) { 735 min = five; 736 mult = 5; 737 } 738 if (*seven < *min) { 739 min = seven; 740 mult = 7; 741 } 742 743 ret = *min; 744 *min *= mult; 745 746 return ret; 747 } 748 749 /* 750 * Check that all of the backup GDT blocks are held in the primary GDT block. 751 * It is assumed that they are stored in group order. Returns the number of 752 * groups in current filesystem that have BACKUPS, or -ve error code. 753 */ 754 static int verify_reserved_gdb(struct super_block *sb, 755 ext4_group_t end, 756 struct buffer_head *primary) 757 { 758 const ext4_fsblk_t blk = primary->b_blocknr; 759 unsigned three = 1; 760 unsigned five = 5; 761 unsigned seven = 7; 762 unsigned grp; 763 __le32 *p = (__le32 *)primary->b_data; 764 int gdbackups = 0; 765 766 while ((grp = ext4_list_backups(sb, &three, &five, &seven)) < end) { 767 if (le32_to_cpu(*p++) != 768 grp * EXT4_BLOCKS_PER_GROUP(sb) + blk){ 769 ext4_warning(sb, "reserved GDT %llu" 770 " missing grp %d (%llu)", 771 blk, grp, 772 grp * 773 (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) + 774 blk); 775 return -EINVAL; 776 } 777 if (++gdbackups > EXT4_ADDR_PER_BLOCK(sb)) 778 return -EFBIG; 779 } 780 781 return gdbackups; 782 } 783 784 /* 785 * Called when we need to bring a reserved group descriptor table block into 786 * use from the resize inode. The primary copy of the new GDT block currently 787 * is an indirect block (under the double indirect block in the resize inode). 788 * The new backup GDT blocks will be stored as leaf blocks in this indirect 789 * block, in group order. Even though we know all the block numbers we need, 790 * we check to ensure that the resize inode has actually reserved these blocks. 791 * 792 * Don't need to update the block bitmaps because the blocks are still in use. 793 * 794 * We get all of the error cases out of the way, so that we are sure to not 795 * fail once we start modifying the data on disk, because JBD has no rollback. 796 */ 797 static int add_new_gdb(handle_t *handle, struct inode *inode, 798 ext4_group_t group) 799 { 800 struct super_block *sb = inode->i_sb; 801 struct ext4_super_block *es = EXT4_SB(sb)->s_es; 802 unsigned long gdb_num = group / EXT4_DESC_PER_BLOCK(sb); 803 ext4_fsblk_t gdblock = EXT4_SB(sb)->s_sbh->b_blocknr + 1 + gdb_num; 804 struct buffer_head **o_group_desc, **n_group_desc = NULL; 805 struct buffer_head *dind = NULL; 806 struct buffer_head *gdb_bh = NULL; 807 int gdbackups; 808 struct ext4_iloc iloc = { .bh = NULL }; 809 __le32 *data; 810 int err; 811 812 if (test_opt(sb, DEBUG)) 813 printk(KERN_DEBUG 814 "EXT4-fs: ext4_add_new_gdb: adding group block %lu\n", 815 gdb_num); 816 817 gdb_bh = ext4_sb_bread(sb, gdblock, 0); 818 if (IS_ERR(gdb_bh)) 819 return PTR_ERR(gdb_bh); 820 821 gdbackups = verify_reserved_gdb(sb, group, gdb_bh); 822 if (gdbackups < 0) { 823 err = gdbackups; 824 goto errout; 825 } 826 827 data = EXT4_I(inode)->i_data + EXT4_DIND_BLOCK; 828 dind = ext4_sb_bread(sb, le32_to_cpu(*data), 0); 829 if (IS_ERR(dind)) { 830 err = PTR_ERR(dind); 831 dind = NULL; 832 goto errout; 833 } 834 835 data = (__le32 *)dind->b_data; 836 if (le32_to_cpu(data[gdb_num % EXT4_ADDR_PER_BLOCK(sb)]) != gdblock) { 837 ext4_warning(sb, "new group %u GDT block %llu not reserved", 838 group, gdblock); 839 err = -EINVAL; 840 goto errout; 841 } 842 843 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access"); 844 err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh); 845 if (unlikely(err)) 846 goto errout; 847 848 BUFFER_TRACE(gdb_bh, "get_write_access"); 849 err = ext4_journal_get_write_access(handle, gdb_bh); 850 if (unlikely(err)) 851 goto errout; 852 853 BUFFER_TRACE(dind, "get_write_access"); 854 err = ext4_journal_get_write_access(handle, dind); 855 if (unlikely(err)) { 856 ext4_std_error(sb, err); 857 goto errout; 858 } 859 860 /* ext4_reserve_inode_write() gets a reference on the iloc */ 861 err = ext4_reserve_inode_write(handle, inode, &iloc); 862 if (unlikely(err)) 863 goto errout; 864 865 n_group_desc = kvmalloc((gdb_num + 1) * sizeof(struct buffer_head *), 866 GFP_KERNEL); 867 if (!n_group_desc) { 868 err = -ENOMEM; 869 ext4_warning(sb, "not enough memory for %lu groups", 870 gdb_num + 1); 871 goto errout; 872 } 873 874 /* 875 * Finally, we have all of the possible failures behind us... 876 * 877 * Remove new GDT block from inode double-indirect block and clear out 878 * the new GDT block for use (which also "frees" the backup GDT blocks 879 * from the reserved inode). We don't need to change the bitmaps for 880 * these blocks, because they are marked as in-use from being in the 881 * reserved inode, and will become GDT blocks (primary and backup). 882 */ 883 data[gdb_num % EXT4_ADDR_PER_BLOCK(sb)] = 0; 884 err = ext4_handle_dirty_metadata(handle, NULL, dind); 885 if (unlikely(err)) { 886 ext4_std_error(sb, err); 887 goto errout; 888 } 889 inode->i_blocks -= (gdbackups + 1) * sb->s_blocksize >> 890 (9 - EXT4_SB(sb)->s_cluster_bits); 891 ext4_mark_iloc_dirty(handle, inode, &iloc); 892 memset(gdb_bh->b_data, 0, sb->s_blocksize); 893 err = ext4_handle_dirty_metadata(handle, NULL, gdb_bh); 894 if (unlikely(err)) { 895 ext4_std_error(sb, err); 896 iloc.bh = NULL; 897 goto errout; 898 } 899 brelse(dind); 900 901 rcu_read_lock(); 902 o_group_desc = rcu_dereference(EXT4_SB(sb)->s_group_desc); 903 memcpy(n_group_desc, o_group_desc, 904 EXT4_SB(sb)->s_gdb_count * sizeof(struct buffer_head *)); 905 rcu_read_unlock(); 906 n_group_desc[gdb_num] = gdb_bh; 907 rcu_assign_pointer(EXT4_SB(sb)->s_group_desc, n_group_desc); 908 EXT4_SB(sb)->s_gdb_count++; 909 ext4_kvfree_array_rcu(o_group_desc); 910 911 lock_buffer(EXT4_SB(sb)->s_sbh); 912 le16_add_cpu(&es->s_reserved_gdt_blocks, -1); 913 ext4_superblock_csum_set(sb); 914 unlock_buffer(EXT4_SB(sb)->s_sbh); 915 err = ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh); 916 if (err) 917 ext4_std_error(sb, err); 918 return err; 919 errout: 920 kvfree(n_group_desc); 921 brelse(iloc.bh); 922 brelse(dind); 923 brelse(gdb_bh); 924 925 ext4_debug("leaving with error %d\n", err); 926 return err; 927 } 928 929 /* 930 * add_new_gdb_meta_bg is the sister of add_new_gdb. 931 */ 932 static int add_new_gdb_meta_bg(struct super_block *sb, 933 handle_t *handle, ext4_group_t group) { 934 ext4_fsblk_t gdblock; 935 struct buffer_head *gdb_bh; 936 struct buffer_head **o_group_desc, **n_group_desc; 937 unsigned long gdb_num = group / EXT4_DESC_PER_BLOCK(sb); 938 int err; 939 940 gdblock = ext4_meta_bg_first_block_no(sb, group) + 941 ext4_bg_has_super(sb, group); 942 gdb_bh = ext4_sb_bread(sb, gdblock, 0); 943 if (IS_ERR(gdb_bh)) 944 return PTR_ERR(gdb_bh); 945 n_group_desc = kvmalloc((gdb_num + 1) * sizeof(struct buffer_head *), 946 GFP_KERNEL); 947 if (!n_group_desc) { 948 brelse(gdb_bh); 949 err = -ENOMEM; 950 ext4_warning(sb, "not enough memory for %lu groups", 951 gdb_num + 1); 952 return err; 953 } 954 955 rcu_read_lock(); 956 o_group_desc = rcu_dereference(EXT4_SB(sb)->s_group_desc); 957 memcpy(n_group_desc, o_group_desc, 958 EXT4_SB(sb)->s_gdb_count * sizeof(struct buffer_head *)); 959 rcu_read_unlock(); 960 n_group_desc[gdb_num] = gdb_bh; 961 962 BUFFER_TRACE(gdb_bh, "get_write_access"); 963 err = ext4_journal_get_write_access(handle, gdb_bh); 964 if (err) { 965 kvfree(n_group_desc); 966 brelse(gdb_bh); 967 return err; 968 } 969 970 rcu_assign_pointer(EXT4_SB(sb)->s_group_desc, n_group_desc); 971 EXT4_SB(sb)->s_gdb_count++; 972 ext4_kvfree_array_rcu(o_group_desc); 973 return err; 974 } 975 976 /* 977 * Called when we are adding a new group which has a backup copy of each of 978 * the GDT blocks (i.e. sparse group) and there are reserved GDT blocks. 979 * We need to add these reserved backup GDT blocks to the resize inode, so 980 * that they are kept for future resizing and not allocated to files. 981 * 982 * Each reserved backup GDT block will go into a different indirect block. 983 * The indirect blocks are actually the primary reserved GDT blocks, 984 * so we know in advance what their block numbers are. We only get the 985 * double-indirect block to verify it is pointing to the primary reserved 986 * GDT blocks so we don't overwrite a data block by accident. The reserved 987 * backup GDT blocks are stored in their reserved primary GDT block. 988 */ 989 static int reserve_backup_gdb(handle_t *handle, struct inode *inode, 990 ext4_group_t group) 991 { 992 struct super_block *sb = inode->i_sb; 993 int reserved_gdb =le16_to_cpu(EXT4_SB(sb)->s_es->s_reserved_gdt_blocks); 994 int cluster_bits = EXT4_SB(sb)->s_cluster_bits; 995 struct buffer_head **primary; 996 struct buffer_head *dind; 997 struct ext4_iloc iloc; 998 ext4_fsblk_t blk; 999 __le32 *data, *end; 1000 int gdbackups = 0; 1001 int res, i; 1002 int err; 1003 1004 primary = kmalloc_array(reserved_gdb, sizeof(*primary), GFP_NOFS); 1005 if (!primary) 1006 return -ENOMEM; 1007 1008 data = EXT4_I(inode)->i_data + EXT4_DIND_BLOCK; 1009 dind = ext4_sb_bread(sb, le32_to_cpu(*data), 0); 1010 if (IS_ERR(dind)) { 1011 err = PTR_ERR(dind); 1012 dind = NULL; 1013 goto exit_free; 1014 } 1015 1016 blk = EXT4_SB(sb)->s_sbh->b_blocknr + 1 + EXT4_SB(sb)->s_gdb_count; 1017 data = (__le32 *)dind->b_data + (EXT4_SB(sb)->s_gdb_count % 1018 EXT4_ADDR_PER_BLOCK(sb)); 1019 end = (__le32 *)dind->b_data + EXT4_ADDR_PER_BLOCK(sb); 1020 1021 /* Get each reserved primary GDT block and verify it holds backups */ 1022 for (res = 0; res < reserved_gdb; res++, blk++) { 1023 if (le32_to_cpu(*data) != blk) { 1024 ext4_warning(sb, "reserved block %llu" 1025 " not at offset %ld", 1026 blk, 1027 (long)(data - (__le32 *)dind->b_data)); 1028 err = -EINVAL; 1029 goto exit_bh; 1030 } 1031 primary[res] = ext4_sb_bread(sb, blk, 0); 1032 if (IS_ERR(primary[res])) { 1033 err = PTR_ERR(primary[res]); 1034 primary[res] = NULL; 1035 goto exit_bh; 1036 } 1037 gdbackups = verify_reserved_gdb(sb, group, primary[res]); 1038 if (gdbackups < 0) { 1039 brelse(primary[res]); 1040 err = gdbackups; 1041 goto exit_bh; 1042 } 1043 if (++data >= end) 1044 data = (__le32 *)dind->b_data; 1045 } 1046 1047 for (i = 0; i < reserved_gdb; i++) { 1048 BUFFER_TRACE(primary[i], "get_write_access"); 1049 if ((err = ext4_journal_get_write_access(handle, primary[i]))) 1050 goto exit_bh; 1051 } 1052 1053 if ((err = ext4_reserve_inode_write(handle, inode, &iloc))) 1054 goto exit_bh; 1055 1056 /* 1057 * Finally we can add each of the reserved backup GDT blocks from 1058 * the new group to its reserved primary GDT block. 1059 */ 1060 blk = group * EXT4_BLOCKS_PER_GROUP(sb); 1061 for (i = 0; i < reserved_gdb; i++) { 1062 int err2; 1063 data = (__le32 *)primary[i]->b_data; 1064 /* printk("reserving backup %lu[%u] = %lu\n", 1065 primary[i]->b_blocknr, gdbackups, 1066 blk + primary[i]->b_blocknr); */ 1067 data[gdbackups] = cpu_to_le32(blk + primary[i]->b_blocknr); 1068 err2 = ext4_handle_dirty_metadata(handle, NULL, primary[i]); 1069 if (!err) 1070 err = err2; 1071 } 1072 1073 inode->i_blocks += reserved_gdb * sb->s_blocksize >> (9 - cluster_bits); 1074 ext4_mark_iloc_dirty(handle, inode, &iloc); 1075 1076 exit_bh: 1077 while (--res >= 0) 1078 brelse(primary[res]); 1079 brelse(dind); 1080 1081 exit_free: 1082 kfree(primary); 1083 1084 return err; 1085 } 1086 1087 /* 1088 * Update the backup copies of the ext4 metadata. These don't need to be part 1089 * of the main resize transaction, because e2fsck will re-write them if there 1090 * is a problem (basically only OOM will cause a problem). However, we 1091 * _should_ update the backups if possible, in case the primary gets trashed 1092 * for some reason and we need to run e2fsck from a backup superblock. The 1093 * important part is that the new block and inode counts are in the backup 1094 * superblocks, and the location of the new group metadata in the GDT backups. 1095 * 1096 * We do not need take the s_resize_lock for this, because these 1097 * blocks are not otherwise touched by the filesystem code when it is 1098 * mounted. We don't need to worry about last changing from 1099 * sbi->s_groups_count, because the worst that can happen is that we 1100 * do not copy the full number of backups at this time. The resize 1101 * which changed s_groups_count will backup again. 1102 */ 1103 static void update_backups(struct super_block *sb, sector_t blk_off, char *data, 1104 int size, int meta_bg) 1105 { 1106 struct ext4_sb_info *sbi = EXT4_SB(sb); 1107 ext4_group_t last; 1108 const int bpg = EXT4_BLOCKS_PER_GROUP(sb); 1109 unsigned three = 1; 1110 unsigned five = 5; 1111 unsigned seven = 7; 1112 ext4_group_t group = 0; 1113 int rest = sb->s_blocksize - size; 1114 handle_t *handle; 1115 int err = 0, err2; 1116 1117 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, EXT4_MAX_TRANS_DATA); 1118 if (IS_ERR(handle)) { 1119 group = 1; 1120 err = PTR_ERR(handle); 1121 goto exit_err; 1122 } 1123 1124 if (meta_bg == 0) { 1125 group = ext4_list_backups(sb, &three, &five, &seven); 1126 last = sbi->s_groups_count; 1127 } else { 1128 group = ext4_get_group_number(sb, blk_off) + 1; 1129 last = (ext4_group_t)(group + EXT4_DESC_PER_BLOCK(sb) - 2); 1130 } 1131 1132 while (group < sbi->s_groups_count) { 1133 struct buffer_head *bh; 1134 ext4_fsblk_t backup_block; 1135 1136 /* Out of journal space, and can't get more - abort - so sad */ 1137 err = ext4_resize_ensure_credits_batch(handle, 1); 1138 if (err < 0) 1139 break; 1140 1141 if (meta_bg == 0) 1142 backup_block = ((ext4_fsblk_t)group) * bpg + blk_off; 1143 else 1144 backup_block = (ext4_group_first_block_no(sb, group) + 1145 ext4_bg_has_super(sb, group)); 1146 1147 bh = sb_getblk(sb, backup_block); 1148 if (unlikely(!bh)) { 1149 err = -ENOMEM; 1150 break; 1151 } 1152 ext4_debug("update metadata backup %llu(+%llu)\n", 1153 backup_block, backup_block - 1154 ext4_group_first_block_no(sb, group)); 1155 BUFFER_TRACE(bh, "get_write_access"); 1156 if ((err = ext4_journal_get_write_access(handle, bh))) { 1157 brelse(bh); 1158 break; 1159 } 1160 lock_buffer(bh); 1161 memcpy(bh->b_data, data, size); 1162 if (rest) 1163 memset(bh->b_data + size, 0, rest); 1164 set_buffer_uptodate(bh); 1165 unlock_buffer(bh); 1166 err = ext4_handle_dirty_metadata(handle, NULL, bh); 1167 if (unlikely(err)) 1168 ext4_std_error(sb, err); 1169 brelse(bh); 1170 1171 if (meta_bg == 0) 1172 group = ext4_list_backups(sb, &three, &five, &seven); 1173 else if (group == last) 1174 break; 1175 else 1176 group = last; 1177 } 1178 if ((err2 = ext4_journal_stop(handle)) && !err) 1179 err = err2; 1180 1181 /* 1182 * Ugh! Need to have e2fsck write the backup copies. It is too 1183 * late to revert the resize, we shouldn't fail just because of 1184 * the backup copies (they are only needed in case of corruption). 1185 * 1186 * However, if we got here we have a journal problem too, so we 1187 * can't really start a transaction to mark the superblock. 1188 * Chicken out and just set the flag on the hope it will be written 1189 * to disk, and if not - we will simply wait until next fsck. 1190 */ 1191 exit_err: 1192 if (err) { 1193 ext4_warning(sb, "can't update backup for group %u (err %d), " 1194 "forcing fsck on next reboot", group, err); 1195 sbi->s_mount_state &= ~EXT4_VALID_FS; 1196 sbi->s_es->s_state &= cpu_to_le16(~EXT4_VALID_FS); 1197 mark_buffer_dirty(sbi->s_sbh); 1198 } 1199 } 1200 1201 /* 1202 * ext4_add_new_descs() adds @count group descriptor of groups 1203 * starting at @group 1204 * 1205 * @handle: journal handle 1206 * @sb: super block 1207 * @group: the group no. of the first group desc to be added 1208 * @resize_inode: the resize inode 1209 * @count: number of group descriptors to be added 1210 */ 1211 static int ext4_add_new_descs(handle_t *handle, struct super_block *sb, 1212 ext4_group_t group, struct inode *resize_inode, 1213 ext4_group_t count) 1214 { 1215 struct ext4_sb_info *sbi = EXT4_SB(sb); 1216 struct ext4_super_block *es = sbi->s_es; 1217 struct buffer_head *gdb_bh; 1218 int i, gdb_off, gdb_num, err = 0; 1219 int meta_bg; 1220 1221 meta_bg = ext4_has_feature_meta_bg(sb); 1222 for (i = 0; i < count; i++, group++) { 1223 int reserved_gdb = ext4_bg_has_super(sb, group) ? 1224 le16_to_cpu(es->s_reserved_gdt_blocks) : 0; 1225 1226 gdb_off = group % EXT4_DESC_PER_BLOCK(sb); 1227 gdb_num = group / EXT4_DESC_PER_BLOCK(sb); 1228 1229 /* 1230 * We will only either add reserved group blocks to a backup group 1231 * or remove reserved blocks for the first group in a new group block. 1232 * Doing both would be mean more complex code, and sane people don't 1233 * use non-sparse filesystems anymore. This is already checked above. 1234 */ 1235 if (gdb_off) { 1236 gdb_bh = sbi_array_rcu_deref(sbi, s_group_desc, 1237 gdb_num); 1238 BUFFER_TRACE(gdb_bh, "get_write_access"); 1239 err = ext4_journal_get_write_access(handle, gdb_bh); 1240 1241 if (!err && reserved_gdb && ext4_bg_num_gdb(sb, group)) 1242 err = reserve_backup_gdb(handle, resize_inode, group); 1243 } else if (meta_bg != 0) { 1244 err = add_new_gdb_meta_bg(sb, handle, group); 1245 } else { 1246 err = add_new_gdb(handle, resize_inode, group); 1247 } 1248 if (err) 1249 break; 1250 } 1251 return err; 1252 } 1253 1254 static struct buffer_head *ext4_get_bitmap(struct super_block *sb, __u64 block) 1255 { 1256 struct buffer_head *bh = sb_getblk(sb, block); 1257 if (unlikely(!bh)) 1258 return NULL; 1259 if (!bh_uptodate_or_lock(bh)) { 1260 if (ext4_read_bh(bh, 0, NULL) < 0) { 1261 brelse(bh); 1262 return NULL; 1263 } 1264 } 1265 1266 return bh; 1267 } 1268 1269 static int ext4_set_bitmap_checksums(struct super_block *sb, 1270 ext4_group_t group, 1271 struct ext4_group_desc *gdp, 1272 struct ext4_new_group_data *group_data) 1273 { 1274 struct buffer_head *bh; 1275 1276 if (!ext4_has_metadata_csum(sb)) 1277 return 0; 1278 1279 bh = ext4_get_bitmap(sb, group_data->inode_bitmap); 1280 if (!bh) 1281 return -EIO; 1282 ext4_inode_bitmap_csum_set(sb, group, gdp, bh, 1283 EXT4_INODES_PER_GROUP(sb) / 8); 1284 brelse(bh); 1285 1286 bh = ext4_get_bitmap(sb, group_data->block_bitmap); 1287 if (!bh) 1288 return -EIO; 1289 ext4_block_bitmap_csum_set(sb, group, gdp, bh); 1290 brelse(bh); 1291 1292 return 0; 1293 } 1294 1295 /* 1296 * ext4_setup_new_descs() will set up the group descriptor descriptors of a flex bg 1297 */ 1298 static int ext4_setup_new_descs(handle_t *handle, struct super_block *sb, 1299 struct ext4_new_flex_group_data *flex_gd) 1300 { 1301 struct ext4_new_group_data *group_data = flex_gd->groups; 1302 struct ext4_group_desc *gdp; 1303 struct ext4_sb_info *sbi = EXT4_SB(sb); 1304 struct buffer_head *gdb_bh; 1305 ext4_group_t group; 1306 __u16 *bg_flags = flex_gd->bg_flags; 1307 int i, gdb_off, gdb_num, err = 0; 1308 1309 1310 for (i = 0; i < flex_gd->count; i++, group_data++, bg_flags++) { 1311 group = group_data->group; 1312 1313 gdb_off = group % EXT4_DESC_PER_BLOCK(sb); 1314 gdb_num = group / EXT4_DESC_PER_BLOCK(sb); 1315 1316 /* 1317 * get_write_access() has been called on gdb_bh by ext4_add_new_desc(). 1318 */ 1319 gdb_bh = sbi_array_rcu_deref(sbi, s_group_desc, gdb_num); 1320 /* Update group descriptor block for new group */ 1321 gdp = (struct ext4_group_desc *)(gdb_bh->b_data + 1322 gdb_off * EXT4_DESC_SIZE(sb)); 1323 1324 memset(gdp, 0, EXT4_DESC_SIZE(sb)); 1325 ext4_block_bitmap_set(sb, gdp, group_data->block_bitmap); 1326 ext4_inode_bitmap_set(sb, gdp, group_data->inode_bitmap); 1327 err = ext4_set_bitmap_checksums(sb, group, gdp, group_data); 1328 if (err) { 1329 ext4_std_error(sb, err); 1330 break; 1331 } 1332 1333 ext4_inode_table_set(sb, gdp, group_data->inode_table); 1334 ext4_free_group_clusters_set(sb, gdp, 1335 group_data->free_clusters_count); 1336 ext4_free_inodes_set(sb, gdp, EXT4_INODES_PER_GROUP(sb)); 1337 if (ext4_has_group_desc_csum(sb)) 1338 ext4_itable_unused_set(sb, gdp, 1339 EXT4_INODES_PER_GROUP(sb)); 1340 gdp->bg_flags = cpu_to_le16(*bg_flags); 1341 ext4_group_desc_csum_set(sb, group, gdp); 1342 1343 err = ext4_handle_dirty_metadata(handle, NULL, gdb_bh); 1344 if (unlikely(err)) { 1345 ext4_std_error(sb, err); 1346 break; 1347 } 1348 1349 /* 1350 * We can allocate memory for mb_alloc based on the new group 1351 * descriptor 1352 */ 1353 err = ext4_mb_add_groupinfo(sb, group, gdp); 1354 if (err) 1355 break; 1356 } 1357 return err; 1358 } 1359 1360 /* 1361 * ext4_update_super() updates the super block so that the newly added 1362 * groups can be seen by the filesystem. 1363 * 1364 * @sb: super block 1365 * @flex_gd: new added groups 1366 */ 1367 static void ext4_update_super(struct super_block *sb, 1368 struct ext4_new_flex_group_data *flex_gd) 1369 { 1370 ext4_fsblk_t blocks_count = 0; 1371 ext4_fsblk_t free_blocks = 0; 1372 ext4_fsblk_t reserved_blocks = 0; 1373 struct ext4_new_group_data *group_data = flex_gd->groups; 1374 struct ext4_sb_info *sbi = EXT4_SB(sb); 1375 struct ext4_super_block *es = sbi->s_es; 1376 int i; 1377 1378 BUG_ON(flex_gd->count == 0 || group_data == NULL); 1379 /* 1380 * Make the new blocks and inodes valid next. We do this before 1381 * increasing the group count so that once the group is enabled, 1382 * all of its blocks and inodes are already valid. 1383 * 1384 * We always allocate group-by-group, then block-by-block or 1385 * inode-by-inode within a group, so enabling these 1386 * blocks/inodes before the group is live won't actually let us 1387 * allocate the new space yet. 1388 */ 1389 for (i = 0; i < flex_gd->count; i++) { 1390 blocks_count += group_data[i].blocks_count; 1391 free_blocks += EXT4_C2B(sbi, group_data[i].free_clusters_count); 1392 } 1393 1394 reserved_blocks = ext4_r_blocks_count(es) * 100; 1395 reserved_blocks = div64_u64(reserved_blocks, ext4_blocks_count(es)); 1396 reserved_blocks *= blocks_count; 1397 do_div(reserved_blocks, 100); 1398 1399 lock_buffer(sbi->s_sbh); 1400 ext4_blocks_count_set(es, ext4_blocks_count(es) + blocks_count); 1401 ext4_free_blocks_count_set(es, ext4_free_blocks_count(es) + free_blocks); 1402 le32_add_cpu(&es->s_inodes_count, EXT4_INODES_PER_GROUP(sb) * 1403 flex_gd->count); 1404 le32_add_cpu(&es->s_free_inodes_count, EXT4_INODES_PER_GROUP(sb) * 1405 flex_gd->count); 1406 1407 ext4_debug("free blocks count %llu", ext4_free_blocks_count(es)); 1408 /* 1409 * We need to protect s_groups_count against other CPUs seeing 1410 * inconsistent state in the superblock. 1411 * 1412 * The precise rules we use are: 1413 * 1414 * * Writers must perform a smp_wmb() after updating all 1415 * dependent data and before modifying the groups count 1416 * 1417 * * Readers must perform an smp_rmb() after reading the groups 1418 * count and before reading any dependent data. 1419 * 1420 * NB. These rules can be relaxed when checking the group count 1421 * while freeing data, as we can only allocate from a block 1422 * group after serialising against the group count, and we can 1423 * only then free after serialising in turn against that 1424 * allocation. 1425 */ 1426 smp_wmb(); 1427 1428 /* Update the global fs size fields */ 1429 sbi->s_groups_count += flex_gd->count; 1430 sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count, 1431 (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb))); 1432 1433 /* Update the reserved block counts only once the new group is 1434 * active. */ 1435 ext4_r_blocks_count_set(es, ext4_r_blocks_count(es) + 1436 reserved_blocks); 1437 ext4_superblock_csum_set(sb); 1438 unlock_buffer(sbi->s_sbh); 1439 1440 /* Update the free space counts */ 1441 percpu_counter_add(&sbi->s_freeclusters_counter, 1442 EXT4_NUM_B2C(sbi, free_blocks)); 1443 percpu_counter_add(&sbi->s_freeinodes_counter, 1444 EXT4_INODES_PER_GROUP(sb) * flex_gd->count); 1445 1446 ext4_debug("free blocks count %llu", 1447 percpu_counter_read(&sbi->s_freeclusters_counter)); 1448 if (ext4_has_feature_flex_bg(sb) && sbi->s_log_groups_per_flex) { 1449 ext4_group_t flex_group; 1450 struct flex_groups *fg; 1451 1452 flex_group = ext4_flex_group(sbi, group_data[0].group); 1453 fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group); 1454 atomic64_add(EXT4_NUM_B2C(sbi, free_blocks), 1455 &fg->free_clusters); 1456 atomic_add(EXT4_INODES_PER_GROUP(sb) * flex_gd->count, 1457 &fg->free_inodes); 1458 } 1459 1460 /* 1461 * Update the fs overhead information 1462 */ 1463 ext4_calculate_overhead(sb); 1464 1465 if (test_opt(sb, DEBUG)) 1466 printk(KERN_DEBUG "EXT4-fs: added group %u:" 1467 "%llu blocks(%llu free %llu reserved)\n", flex_gd->count, 1468 blocks_count, free_blocks, reserved_blocks); 1469 } 1470 1471 /* Add a flex group to an fs. Ensure we handle all possible error conditions 1472 * _before_ we start modifying the filesystem, because we cannot abort the 1473 * transaction and not have it write the data to disk. 1474 */ 1475 static int ext4_flex_group_add(struct super_block *sb, 1476 struct inode *resize_inode, 1477 struct ext4_new_flex_group_data *flex_gd) 1478 { 1479 struct ext4_sb_info *sbi = EXT4_SB(sb); 1480 struct ext4_super_block *es = sbi->s_es; 1481 ext4_fsblk_t o_blocks_count; 1482 ext4_grpblk_t last; 1483 ext4_group_t group; 1484 handle_t *handle; 1485 unsigned reserved_gdb; 1486 int err = 0, err2 = 0, credit; 1487 1488 BUG_ON(!flex_gd->count || !flex_gd->groups || !flex_gd->bg_flags); 1489 1490 reserved_gdb = le16_to_cpu(es->s_reserved_gdt_blocks); 1491 o_blocks_count = ext4_blocks_count(es); 1492 ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last); 1493 BUG_ON(last); 1494 1495 err = setup_new_flex_group_blocks(sb, flex_gd); 1496 if (err) 1497 goto exit; 1498 /* 1499 * We will always be modifying at least the superblock and GDT 1500 * blocks. If we are adding a group past the last current GDT block, 1501 * we will also modify the inode and the dindirect block. If we 1502 * are adding a group with superblock/GDT backups we will also 1503 * modify each of the reserved GDT dindirect blocks. 1504 */ 1505 credit = 3; /* sb, resize inode, resize inode dindirect */ 1506 /* GDT blocks */ 1507 credit += 1 + DIV_ROUND_UP(flex_gd->count, EXT4_DESC_PER_BLOCK(sb)); 1508 credit += reserved_gdb; /* Reserved GDT dindirect blocks */ 1509 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, credit); 1510 if (IS_ERR(handle)) { 1511 err = PTR_ERR(handle); 1512 goto exit; 1513 } 1514 1515 BUFFER_TRACE(sbi->s_sbh, "get_write_access"); 1516 err = ext4_journal_get_write_access(handle, sbi->s_sbh); 1517 if (err) 1518 goto exit_journal; 1519 1520 group = flex_gd->groups[0].group; 1521 BUG_ON(group != sbi->s_groups_count); 1522 err = ext4_add_new_descs(handle, sb, group, 1523 resize_inode, flex_gd->count); 1524 if (err) 1525 goto exit_journal; 1526 1527 err = ext4_setup_new_descs(handle, sb, flex_gd); 1528 if (err) 1529 goto exit_journal; 1530 1531 ext4_update_super(sb, flex_gd); 1532 1533 err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh); 1534 1535 exit_journal: 1536 err2 = ext4_journal_stop(handle); 1537 if (!err) 1538 err = err2; 1539 1540 if (!err) { 1541 int gdb_num = group / EXT4_DESC_PER_BLOCK(sb); 1542 int gdb_num_end = ((group + flex_gd->count - 1) / 1543 EXT4_DESC_PER_BLOCK(sb)); 1544 int meta_bg = ext4_has_feature_meta_bg(sb); 1545 sector_t old_gdb = 0; 1546 1547 update_backups(sb, sbi->s_sbh->b_blocknr, (char *)es, 1548 sizeof(struct ext4_super_block), 0); 1549 for (; gdb_num <= gdb_num_end; gdb_num++) { 1550 struct buffer_head *gdb_bh; 1551 1552 gdb_bh = sbi_array_rcu_deref(sbi, s_group_desc, 1553 gdb_num); 1554 if (old_gdb == gdb_bh->b_blocknr) 1555 continue; 1556 update_backups(sb, gdb_bh->b_blocknr, gdb_bh->b_data, 1557 gdb_bh->b_size, meta_bg); 1558 old_gdb = gdb_bh->b_blocknr; 1559 } 1560 } 1561 exit: 1562 return err; 1563 } 1564 1565 static int ext4_setup_next_flex_gd(struct super_block *sb, 1566 struct ext4_new_flex_group_data *flex_gd, 1567 ext4_fsblk_t n_blocks_count, 1568 unsigned long flexbg_size) 1569 { 1570 struct ext4_sb_info *sbi = EXT4_SB(sb); 1571 struct ext4_super_block *es = sbi->s_es; 1572 struct ext4_new_group_data *group_data = flex_gd->groups; 1573 ext4_fsblk_t o_blocks_count; 1574 ext4_group_t n_group; 1575 ext4_group_t group; 1576 ext4_group_t last_group; 1577 ext4_grpblk_t last; 1578 ext4_grpblk_t clusters_per_group; 1579 unsigned long i; 1580 1581 clusters_per_group = EXT4_CLUSTERS_PER_GROUP(sb); 1582 1583 o_blocks_count = ext4_blocks_count(es); 1584 1585 if (o_blocks_count == n_blocks_count) 1586 return 0; 1587 1588 ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last); 1589 BUG_ON(last); 1590 ext4_get_group_no_and_offset(sb, n_blocks_count - 1, &n_group, &last); 1591 1592 last_group = group | (flexbg_size - 1); 1593 if (last_group > n_group) 1594 last_group = n_group; 1595 1596 flex_gd->count = last_group - group + 1; 1597 1598 for (i = 0; i < flex_gd->count; i++) { 1599 int overhead; 1600 1601 group_data[i].group = group + i; 1602 group_data[i].blocks_count = EXT4_BLOCKS_PER_GROUP(sb); 1603 overhead = ext4_group_overhead_blocks(sb, group + i); 1604 group_data[i].mdata_blocks = overhead; 1605 group_data[i].free_clusters_count = EXT4_CLUSTERS_PER_GROUP(sb); 1606 if (ext4_has_group_desc_csum(sb)) { 1607 flex_gd->bg_flags[i] = EXT4_BG_BLOCK_UNINIT | 1608 EXT4_BG_INODE_UNINIT; 1609 if (!test_opt(sb, INIT_INODE_TABLE)) 1610 flex_gd->bg_flags[i] |= EXT4_BG_INODE_ZEROED; 1611 } else 1612 flex_gd->bg_flags[i] = EXT4_BG_INODE_ZEROED; 1613 } 1614 1615 if (last_group == n_group && ext4_has_group_desc_csum(sb)) 1616 /* We need to initialize block bitmap of last group. */ 1617 flex_gd->bg_flags[i - 1] &= ~EXT4_BG_BLOCK_UNINIT; 1618 1619 if ((last_group == n_group) && (last != clusters_per_group - 1)) { 1620 group_data[i - 1].blocks_count = EXT4_C2B(sbi, last + 1); 1621 group_data[i - 1].free_clusters_count -= clusters_per_group - 1622 last - 1; 1623 } 1624 1625 return 1; 1626 } 1627 1628 /* Add group descriptor data to an existing or new group descriptor block. 1629 * Ensure we handle all possible error conditions _before_ we start modifying 1630 * the filesystem, because we cannot abort the transaction and not have it 1631 * write the data to disk. 1632 * 1633 * If we are on a GDT block boundary, we need to get the reserved GDT block. 1634 * Otherwise, we may need to add backup GDT blocks for a sparse group. 1635 * 1636 * We only need to hold the superblock lock while we are actually adding 1637 * in the new group's counts to the superblock. Prior to that we have 1638 * not really "added" the group at all. We re-check that we are still 1639 * adding in the last group in case things have changed since verifying. 1640 */ 1641 int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input) 1642 { 1643 struct ext4_new_flex_group_data flex_gd; 1644 struct ext4_sb_info *sbi = EXT4_SB(sb); 1645 struct ext4_super_block *es = sbi->s_es; 1646 int reserved_gdb = ext4_bg_has_super(sb, input->group) ? 1647 le16_to_cpu(es->s_reserved_gdt_blocks) : 0; 1648 struct inode *inode = NULL; 1649 int gdb_off; 1650 int err; 1651 __u16 bg_flags = 0; 1652 1653 gdb_off = input->group % EXT4_DESC_PER_BLOCK(sb); 1654 1655 if (gdb_off == 0 && !ext4_has_feature_sparse_super(sb)) { 1656 ext4_warning(sb, "Can't resize non-sparse filesystem further"); 1657 return -EPERM; 1658 } 1659 1660 if (ext4_blocks_count(es) + input->blocks_count < 1661 ext4_blocks_count(es)) { 1662 ext4_warning(sb, "blocks_count overflow"); 1663 return -EINVAL; 1664 } 1665 1666 if (le32_to_cpu(es->s_inodes_count) + EXT4_INODES_PER_GROUP(sb) < 1667 le32_to_cpu(es->s_inodes_count)) { 1668 ext4_warning(sb, "inodes_count overflow"); 1669 return -EINVAL; 1670 } 1671 1672 if (reserved_gdb || gdb_off == 0) { 1673 if (!ext4_has_feature_resize_inode(sb) || 1674 !le16_to_cpu(es->s_reserved_gdt_blocks)) { 1675 ext4_warning(sb, 1676 "No reserved GDT blocks, can't resize"); 1677 return -EPERM; 1678 } 1679 inode = ext4_iget(sb, EXT4_RESIZE_INO, EXT4_IGET_SPECIAL); 1680 if (IS_ERR(inode)) { 1681 ext4_warning(sb, "Error opening resize inode"); 1682 return PTR_ERR(inode); 1683 } 1684 } 1685 1686 1687 err = verify_group_input(sb, input); 1688 if (err) 1689 goto out; 1690 1691 err = ext4_alloc_flex_bg_array(sb, input->group + 1); 1692 if (err) 1693 goto out; 1694 1695 err = ext4_mb_alloc_groupinfo(sb, input->group + 1); 1696 if (err) 1697 goto out; 1698 1699 flex_gd.count = 1; 1700 flex_gd.groups = input; 1701 flex_gd.bg_flags = &bg_flags; 1702 err = ext4_flex_group_add(sb, inode, &flex_gd); 1703 out: 1704 iput(inode); 1705 return err; 1706 } /* ext4_group_add */ 1707 1708 /* 1709 * extend a group without checking assuming that checking has been done. 1710 */ 1711 static int ext4_group_extend_no_check(struct super_block *sb, 1712 ext4_fsblk_t o_blocks_count, ext4_grpblk_t add) 1713 { 1714 struct ext4_super_block *es = EXT4_SB(sb)->s_es; 1715 handle_t *handle; 1716 int err = 0, err2; 1717 1718 /* We will update the superblock, one block bitmap, and 1719 * one group descriptor via ext4_group_add_blocks(). 1720 */ 1721 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, 3); 1722 if (IS_ERR(handle)) { 1723 err = PTR_ERR(handle); 1724 ext4_warning(sb, "error %d on journal start", err); 1725 return err; 1726 } 1727 1728 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access"); 1729 err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh); 1730 if (err) { 1731 ext4_warning(sb, "error %d on journal write access", err); 1732 goto errout; 1733 } 1734 1735 lock_buffer(EXT4_SB(sb)->s_sbh); 1736 ext4_blocks_count_set(es, o_blocks_count + add); 1737 ext4_free_blocks_count_set(es, ext4_free_blocks_count(es) + add); 1738 ext4_superblock_csum_set(sb); 1739 unlock_buffer(EXT4_SB(sb)->s_sbh); 1740 ext4_debug("freeing blocks %llu through %llu\n", o_blocks_count, 1741 o_blocks_count + add); 1742 /* We add the blocks to the bitmap and set the group need init bit */ 1743 err = ext4_group_add_blocks(handle, sb, o_blocks_count, add); 1744 if (err) 1745 goto errout; 1746 ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh); 1747 ext4_debug("freed blocks %llu through %llu\n", o_blocks_count, 1748 o_blocks_count + add); 1749 errout: 1750 err2 = ext4_journal_stop(handle); 1751 if (err2 && !err) 1752 err = err2; 1753 1754 if (!err) { 1755 if (test_opt(sb, DEBUG)) 1756 printk(KERN_DEBUG "EXT4-fs: extended group to %llu " 1757 "blocks\n", ext4_blocks_count(es)); 1758 update_backups(sb, EXT4_SB(sb)->s_sbh->b_blocknr, 1759 (char *)es, sizeof(struct ext4_super_block), 0); 1760 } 1761 return err; 1762 } 1763 1764 /* 1765 * Extend the filesystem to the new number of blocks specified. This entry 1766 * point is only used to extend the current filesystem to the end of the last 1767 * existing group. It can be accessed via ioctl, or by "remount,resize=<size>" 1768 * for emergencies (because it has no dependencies on reserved blocks). 1769 * 1770 * If we _really_ wanted, we could use default values to call ext4_group_add() 1771 * allow the "remount" trick to work for arbitrary resizing, assuming enough 1772 * GDT blocks are reserved to grow to the desired size. 1773 */ 1774 int ext4_group_extend(struct super_block *sb, struct ext4_super_block *es, 1775 ext4_fsblk_t n_blocks_count) 1776 { 1777 ext4_fsblk_t o_blocks_count; 1778 ext4_grpblk_t last; 1779 ext4_grpblk_t add; 1780 struct buffer_head *bh; 1781 int err; 1782 ext4_group_t group; 1783 1784 o_blocks_count = ext4_blocks_count(es); 1785 1786 if (test_opt(sb, DEBUG)) 1787 ext4_msg(sb, KERN_DEBUG, 1788 "extending last group from %llu to %llu blocks", 1789 o_blocks_count, n_blocks_count); 1790 1791 if (n_blocks_count == 0 || n_blocks_count == o_blocks_count) 1792 return 0; 1793 1794 if (n_blocks_count > (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) { 1795 ext4_msg(sb, KERN_ERR, 1796 "filesystem too large to resize to %llu blocks safely", 1797 n_blocks_count); 1798 return -EINVAL; 1799 } 1800 1801 if (n_blocks_count < o_blocks_count) { 1802 ext4_warning(sb, "can't shrink FS - resize aborted"); 1803 return -EINVAL; 1804 } 1805 1806 /* Handle the remaining blocks in the last group only. */ 1807 ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last); 1808 1809 if (last == 0) { 1810 ext4_warning(sb, "need to use ext2online to resize further"); 1811 return -EPERM; 1812 } 1813 1814 add = EXT4_BLOCKS_PER_GROUP(sb) - last; 1815 1816 if (o_blocks_count + add < o_blocks_count) { 1817 ext4_warning(sb, "blocks_count overflow"); 1818 return -EINVAL; 1819 } 1820 1821 if (o_blocks_count + add > n_blocks_count) 1822 add = n_blocks_count - o_blocks_count; 1823 1824 if (o_blocks_count + add < n_blocks_count) 1825 ext4_warning(sb, "will only finish group (%llu blocks, %u new)", 1826 o_blocks_count + add, add); 1827 1828 /* See if the device is actually as big as what was requested */ 1829 bh = ext4_sb_bread(sb, o_blocks_count + add - 1, 0); 1830 if (IS_ERR(bh)) { 1831 ext4_warning(sb, "can't read last block, resize aborted"); 1832 return -ENOSPC; 1833 } 1834 brelse(bh); 1835 1836 err = ext4_group_extend_no_check(sb, o_blocks_count, add); 1837 return err; 1838 } /* ext4_group_extend */ 1839 1840 1841 static int num_desc_blocks(struct super_block *sb, ext4_group_t groups) 1842 { 1843 return (groups + EXT4_DESC_PER_BLOCK(sb) - 1) / EXT4_DESC_PER_BLOCK(sb); 1844 } 1845 1846 /* 1847 * Release the resize inode and drop the resize_inode feature if there 1848 * are no more reserved gdt blocks, and then convert the file system 1849 * to enable meta_bg 1850 */ 1851 static int ext4_convert_meta_bg(struct super_block *sb, struct inode *inode) 1852 { 1853 handle_t *handle; 1854 struct ext4_sb_info *sbi = EXT4_SB(sb); 1855 struct ext4_super_block *es = sbi->s_es; 1856 struct ext4_inode_info *ei = EXT4_I(inode); 1857 ext4_fsblk_t nr; 1858 int i, ret, err = 0; 1859 int credits = 1; 1860 1861 ext4_msg(sb, KERN_INFO, "Converting file system to meta_bg"); 1862 if (inode) { 1863 if (es->s_reserved_gdt_blocks) { 1864 ext4_error(sb, "Unexpected non-zero " 1865 "s_reserved_gdt_blocks"); 1866 return -EPERM; 1867 } 1868 1869 /* Do a quick sanity check of the resize inode */ 1870 if (inode->i_blocks != 1 << (inode->i_blkbits - 1871 (9 - sbi->s_cluster_bits))) 1872 goto invalid_resize_inode; 1873 for (i = 0; i < EXT4_N_BLOCKS; i++) { 1874 if (i == EXT4_DIND_BLOCK) { 1875 if (ei->i_data[i]) 1876 continue; 1877 else 1878 goto invalid_resize_inode; 1879 } 1880 if (ei->i_data[i]) 1881 goto invalid_resize_inode; 1882 } 1883 credits += 3; /* block bitmap, bg descriptor, resize inode */ 1884 } 1885 1886 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, credits); 1887 if (IS_ERR(handle)) 1888 return PTR_ERR(handle); 1889 1890 BUFFER_TRACE(sbi->s_sbh, "get_write_access"); 1891 err = ext4_journal_get_write_access(handle, sbi->s_sbh); 1892 if (err) 1893 goto errout; 1894 1895 lock_buffer(sbi->s_sbh); 1896 ext4_clear_feature_resize_inode(sb); 1897 ext4_set_feature_meta_bg(sb); 1898 sbi->s_es->s_first_meta_bg = 1899 cpu_to_le32(num_desc_blocks(sb, sbi->s_groups_count)); 1900 ext4_superblock_csum_set(sb); 1901 unlock_buffer(sbi->s_sbh); 1902 1903 err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh); 1904 if (err) { 1905 ext4_std_error(sb, err); 1906 goto errout; 1907 } 1908 1909 if (inode) { 1910 nr = le32_to_cpu(ei->i_data[EXT4_DIND_BLOCK]); 1911 ext4_free_blocks(handle, inode, NULL, nr, 1, 1912 EXT4_FREE_BLOCKS_METADATA | 1913 EXT4_FREE_BLOCKS_FORGET); 1914 ei->i_data[EXT4_DIND_BLOCK] = 0; 1915 inode->i_blocks = 0; 1916 1917 err = ext4_mark_inode_dirty(handle, inode); 1918 if (err) 1919 ext4_std_error(sb, err); 1920 } 1921 1922 errout: 1923 ret = ext4_journal_stop(handle); 1924 if (!err) 1925 err = ret; 1926 return ret; 1927 1928 invalid_resize_inode: 1929 ext4_error(sb, "corrupted/inconsistent resize inode"); 1930 return -EINVAL; 1931 } 1932 1933 /* 1934 * ext4_resize_fs() resizes a fs to new size specified by @n_blocks_count 1935 * 1936 * @sb: super block of the fs to be resized 1937 * @n_blocks_count: the number of blocks resides in the resized fs 1938 */ 1939 int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count) 1940 { 1941 struct ext4_new_flex_group_data *flex_gd = NULL; 1942 struct ext4_sb_info *sbi = EXT4_SB(sb); 1943 struct ext4_super_block *es = sbi->s_es; 1944 struct buffer_head *bh; 1945 struct inode *resize_inode = NULL; 1946 ext4_grpblk_t add, offset; 1947 unsigned long n_desc_blocks; 1948 unsigned long o_desc_blocks; 1949 ext4_group_t o_group; 1950 ext4_group_t n_group; 1951 ext4_fsblk_t o_blocks_count; 1952 ext4_fsblk_t n_blocks_count_retry = 0; 1953 unsigned long last_update_time = 0; 1954 int err = 0, flexbg_size = 1 << sbi->s_log_groups_per_flex; 1955 int meta_bg; 1956 1957 /* See if the device is actually as big as what was requested */ 1958 bh = ext4_sb_bread(sb, n_blocks_count - 1, 0); 1959 if (IS_ERR(bh)) { 1960 ext4_warning(sb, "can't read last block, resize aborted"); 1961 return -ENOSPC; 1962 } 1963 brelse(bh); 1964 1965 retry: 1966 o_blocks_count = ext4_blocks_count(es); 1967 1968 ext4_msg(sb, KERN_INFO, "resizing filesystem from %llu " 1969 "to %llu blocks", o_blocks_count, n_blocks_count); 1970 1971 if (n_blocks_count < o_blocks_count) { 1972 /* On-line shrinking not supported */ 1973 ext4_warning(sb, "can't shrink FS - resize aborted"); 1974 return -EINVAL; 1975 } 1976 1977 if (n_blocks_count == o_blocks_count) 1978 /* Nothing need to do */ 1979 return 0; 1980 1981 n_group = ext4_get_group_number(sb, n_blocks_count - 1); 1982 if (n_group >= (0xFFFFFFFFUL / EXT4_INODES_PER_GROUP(sb))) { 1983 ext4_warning(sb, "resize would cause inodes_count overflow"); 1984 return -EINVAL; 1985 } 1986 ext4_get_group_no_and_offset(sb, o_blocks_count - 1, &o_group, &offset); 1987 1988 n_desc_blocks = num_desc_blocks(sb, n_group + 1); 1989 o_desc_blocks = num_desc_blocks(sb, sbi->s_groups_count); 1990 1991 meta_bg = ext4_has_feature_meta_bg(sb); 1992 1993 if (ext4_has_feature_resize_inode(sb)) { 1994 if (meta_bg) { 1995 ext4_error(sb, "resize_inode and meta_bg enabled " 1996 "simultaneously"); 1997 return -EINVAL; 1998 } 1999 if (n_desc_blocks > o_desc_blocks + 2000 le16_to_cpu(es->s_reserved_gdt_blocks)) { 2001 n_blocks_count_retry = n_blocks_count; 2002 n_desc_blocks = o_desc_blocks + 2003 le16_to_cpu(es->s_reserved_gdt_blocks); 2004 n_group = n_desc_blocks * EXT4_DESC_PER_BLOCK(sb); 2005 n_blocks_count = (ext4_fsblk_t)n_group * 2006 EXT4_BLOCKS_PER_GROUP(sb) + 2007 le32_to_cpu(es->s_first_data_block); 2008 n_group--; /* set to last group number */ 2009 } 2010 2011 if (!resize_inode) 2012 resize_inode = ext4_iget(sb, EXT4_RESIZE_INO, 2013 EXT4_IGET_SPECIAL); 2014 if (IS_ERR(resize_inode)) { 2015 ext4_warning(sb, "Error opening resize inode"); 2016 return PTR_ERR(resize_inode); 2017 } 2018 } 2019 2020 if ((!resize_inode && !meta_bg) || n_blocks_count == o_blocks_count) { 2021 err = ext4_convert_meta_bg(sb, resize_inode); 2022 if (err) 2023 goto out; 2024 if (resize_inode) { 2025 iput(resize_inode); 2026 resize_inode = NULL; 2027 } 2028 if (n_blocks_count_retry) { 2029 n_blocks_count = n_blocks_count_retry; 2030 n_blocks_count_retry = 0; 2031 goto retry; 2032 } 2033 } 2034 2035 /* 2036 * Make sure the last group has enough space so that it's 2037 * guaranteed to have enough space for all metadata blocks 2038 * that it might need to hold. (We might not need to store 2039 * the inode table blocks in the last block group, but there 2040 * will be cases where this might be needed.) 2041 */ 2042 if ((ext4_group_first_block_no(sb, n_group) + 2043 ext4_group_overhead_blocks(sb, n_group) + 2 + 2044 sbi->s_itb_per_group + sbi->s_cluster_ratio) >= n_blocks_count) { 2045 n_blocks_count = ext4_group_first_block_no(sb, n_group); 2046 n_group--; 2047 n_blocks_count_retry = 0; 2048 if (resize_inode) { 2049 iput(resize_inode); 2050 resize_inode = NULL; 2051 } 2052 goto retry; 2053 } 2054 2055 /* extend the last group */ 2056 if (n_group == o_group) 2057 add = n_blocks_count - o_blocks_count; 2058 else 2059 add = EXT4_C2B(sbi, EXT4_CLUSTERS_PER_GROUP(sb) - (offset + 1)); 2060 if (add > 0) { 2061 err = ext4_group_extend_no_check(sb, o_blocks_count, add); 2062 if (err) 2063 goto out; 2064 } 2065 2066 if (ext4_blocks_count(es) == n_blocks_count) 2067 goto out; 2068 2069 err = ext4_alloc_flex_bg_array(sb, n_group + 1); 2070 if (err) 2071 goto out; 2072 2073 err = ext4_mb_alloc_groupinfo(sb, n_group + 1); 2074 if (err) 2075 goto out; 2076 2077 flex_gd = alloc_flex_gd(flexbg_size); 2078 if (flex_gd == NULL) { 2079 err = -ENOMEM; 2080 goto out; 2081 } 2082 2083 /* Add flex groups. Note that a regular group is a 2084 * flex group with 1 group. 2085 */ 2086 while (ext4_setup_next_flex_gd(sb, flex_gd, n_blocks_count, 2087 flexbg_size)) { 2088 if (jiffies - last_update_time > HZ * 10) { 2089 if (last_update_time) 2090 ext4_msg(sb, KERN_INFO, 2091 "resized to %llu blocks", 2092 ext4_blocks_count(es)); 2093 last_update_time = jiffies; 2094 } 2095 if (ext4_alloc_group_tables(sb, flex_gd, flexbg_size) != 0) 2096 break; 2097 err = ext4_flex_group_add(sb, resize_inode, flex_gd); 2098 if (unlikely(err)) 2099 break; 2100 } 2101 2102 if (!err && n_blocks_count_retry) { 2103 n_blocks_count = n_blocks_count_retry; 2104 n_blocks_count_retry = 0; 2105 free_flex_gd(flex_gd); 2106 flex_gd = NULL; 2107 if (resize_inode) { 2108 iput(resize_inode); 2109 resize_inode = NULL; 2110 } 2111 goto retry; 2112 } 2113 2114 out: 2115 if (flex_gd) 2116 free_flex_gd(flex_gd); 2117 if (resize_inode != NULL) 2118 iput(resize_inode); 2119 if (err) 2120 ext4_warning(sb, "error (%d) occurred during " 2121 "file system resize", err); 2122 ext4_msg(sb, KERN_INFO, "resized filesystem to %llu", 2123 ext4_blocks_count(es)); 2124 return err; 2125 } 2126