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_sparse_super2(sb)) { 78 ext4_msg(sb, KERN_ERR, "Online resizing not supported with sparse_super2"); 79 return -EOPNOTSUPP; 80 } 81 82 if (test_and_set_bit_lock(EXT4_FLAGS_RESIZING, 83 &EXT4_SB(sb)->s_ext4_flags)) 84 ret = -EBUSY; 85 86 return ret; 87 } 88 89 void ext4_resize_end(struct super_block *sb) 90 { 91 clear_bit_unlock(EXT4_FLAGS_RESIZING, &EXT4_SB(sb)->s_ext4_flags); 92 smp_mb__after_atomic(); 93 } 94 95 static ext4_group_t ext4_meta_bg_first_group(struct super_block *sb, 96 ext4_group_t group) { 97 return (group >> EXT4_DESC_PER_BLOCK_BITS(sb)) << 98 EXT4_DESC_PER_BLOCK_BITS(sb); 99 } 100 101 static ext4_fsblk_t ext4_meta_bg_first_block_no(struct super_block *sb, 102 ext4_group_t group) { 103 group = ext4_meta_bg_first_group(sb, group); 104 return ext4_group_first_block_no(sb, group); 105 } 106 107 static ext4_grpblk_t ext4_group_overhead_blocks(struct super_block *sb, 108 ext4_group_t group) { 109 ext4_grpblk_t overhead; 110 overhead = ext4_bg_num_gdb(sb, group); 111 if (ext4_bg_has_super(sb, group)) 112 overhead += 1 + 113 le16_to_cpu(EXT4_SB(sb)->s_es->s_reserved_gdt_blocks); 114 return overhead; 115 } 116 117 #define outside(b, first, last) ((b) < (first) || (b) >= (last)) 118 #define inside(b, first, last) ((b) >= (first) && (b) < (last)) 119 120 static int verify_group_input(struct super_block *sb, 121 struct ext4_new_group_data *input) 122 { 123 struct ext4_sb_info *sbi = EXT4_SB(sb); 124 struct ext4_super_block *es = sbi->s_es; 125 ext4_fsblk_t start = ext4_blocks_count(es); 126 ext4_fsblk_t end = start + input->blocks_count; 127 ext4_group_t group = input->group; 128 ext4_fsblk_t itend = input->inode_table + sbi->s_itb_per_group; 129 unsigned overhead; 130 ext4_fsblk_t metaend; 131 struct buffer_head *bh = NULL; 132 ext4_grpblk_t free_blocks_count, offset; 133 int err = -EINVAL; 134 135 if (group != sbi->s_groups_count) { 136 ext4_warning(sb, "Cannot add at group %u (only %u groups)", 137 input->group, sbi->s_groups_count); 138 return -EINVAL; 139 } 140 141 overhead = ext4_group_overhead_blocks(sb, group); 142 metaend = start + overhead; 143 input->free_clusters_count = free_blocks_count = 144 input->blocks_count - 2 - overhead - sbi->s_itb_per_group; 145 146 if (test_opt(sb, DEBUG)) 147 printk(KERN_DEBUG "EXT4-fs: adding %s group %u: %u blocks " 148 "(%d free, %u reserved)\n", 149 ext4_bg_has_super(sb, input->group) ? "normal" : 150 "no-super", input->group, input->blocks_count, 151 free_blocks_count, input->reserved_blocks); 152 153 ext4_get_group_no_and_offset(sb, start, NULL, &offset); 154 if (offset != 0) 155 ext4_warning(sb, "Last group not full"); 156 else if (input->reserved_blocks > input->blocks_count / 5) 157 ext4_warning(sb, "Reserved blocks too high (%u)", 158 input->reserved_blocks); 159 else if (free_blocks_count < 0) 160 ext4_warning(sb, "Bad blocks count %u", 161 input->blocks_count); 162 else if (IS_ERR(bh = ext4_sb_bread(sb, end - 1, 0))) { 163 err = PTR_ERR(bh); 164 bh = NULL; 165 ext4_warning(sb, "Cannot read last block (%llu)", 166 end - 1); 167 } else if (outside(input->block_bitmap, start, end)) 168 ext4_warning(sb, "Block bitmap not in group (block %llu)", 169 (unsigned long long)input->block_bitmap); 170 else if (outside(input->inode_bitmap, start, end)) 171 ext4_warning(sb, "Inode bitmap not in group (block %llu)", 172 (unsigned long long)input->inode_bitmap); 173 else if (outside(input->inode_table, start, end) || 174 outside(itend - 1, start, end)) 175 ext4_warning(sb, "Inode table not in group (blocks %llu-%llu)", 176 (unsigned long long)input->inode_table, itend - 1); 177 else if (input->inode_bitmap == input->block_bitmap) 178 ext4_warning(sb, "Block bitmap same as inode bitmap (%llu)", 179 (unsigned long long)input->block_bitmap); 180 else if (inside(input->block_bitmap, input->inode_table, itend)) 181 ext4_warning(sb, "Block bitmap (%llu) in inode table " 182 "(%llu-%llu)", 183 (unsigned long long)input->block_bitmap, 184 (unsigned long long)input->inode_table, itend - 1); 185 else if (inside(input->inode_bitmap, input->inode_table, itend)) 186 ext4_warning(sb, "Inode bitmap (%llu) in inode table " 187 "(%llu-%llu)", 188 (unsigned long long)input->inode_bitmap, 189 (unsigned long long)input->inode_table, itend - 1); 190 else if (inside(input->block_bitmap, start, metaend)) 191 ext4_warning(sb, "Block bitmap (%llu) in GDT table (%llu-%llu)", 192 (unsigned long long)input->block_bitmap, 193 start, metaend - 1); 194 else if (inside(input->inode_bitmap, start, metaend)) 195 ext4_warning(sb, "Inode bitmap (%llu) in GDT table (%llu-%llu)", 196 (unsigned long long)input->inode_bitmap, 197 start, metaend - 1); 198 else if (inside(input->inode_table, start, metaend) || 199 inside(itend - 1, start, metaend)) 200 ext4_warning(sb, "Inode table (%llu-%llu) overlaps GDT table " 201 "(%llu-%llu)", 202 (unsigned long long)input->inode_table, 203 itend - 1, start, metaend - 1); 204 else 205 err = 0; 206 brelse(bh); 207 208 return err; 209 } 210 211 /* 212 * ext4_new_flex_group_data is used by 64bit-resize interface to add a flex 213 * group each time. 214 */ 215 struct ext4_new_flex_group_data { 216 struct ext4_new_group_data *groups; /* new_group_data for groups 217 in the flex group */ 218 __u16 *bg_flags; /* block group flags of groups 219 in @groups */ 220 ext4_group_t count; /* number of groups in @groups 221 */ 222 }; 223 224 /* 225 * alloc_flex_gd() allocates a ext4_new_flex_group_data with size of 226 * @flexbg_size. 227 * 228 * Returns NULL on failure otherwise address of the allocated structure. 229 */ 230 static struct ext4_new_flex_group_data *alloc_flex_gd(unsigned long flexbg_size) 231 { 232 struct ext4_new_flex_group_data *flex_gd; 233 234 flex_gd = kmalloc(sizeof(*flex_gd), GFP_NOFS); 235 if (flex_gd == NULL) 236 goto out3; 237 238 if (flexbg_size >= UINT_MAX / sizeof(struct ext4_new_group_data)) 239 goto out2; 240 flex_gd->count = flexbg_size; 241 242 flex_gd->groups = kmalloc_array(flexbg_size, 243 sizeof(struct ext4_new_group_data), 244 GFP_NOFS); 245 if (flex_gd->groups == NULL) 246 goto out2; 247 248 flex_gd->bg_flags = kmalloc_array(flexbg_size, sizeof(__u16), 249 GFP_NOFS); 250 if (flex_gd->bg_flags == NULL) 251 goto out1; 252 253 return flex_gd; 254 255 out1: 256 kfree(flex_gd->groups); 257 out2: 258 kfree(flex_gd); 259 out3: 260 return NULL; 261 } 262 263 static void free_flex_gd(struct ext4_new_flex_group_data *flex_gd) 264 { 265 kfree(flex_gd->bg_flags); 266 kfree(flex_gd->groups); 267 kfree(flex_gd); 268 } 269 270 /* 271 * ext4_alloc_group_tables() allocates block bitmaps, inode bitmaps 272 * and inode tables for a flex group. 273 * 274 * This function is used by 64bit-resize. Note that this function allocates 275 * group tables from the 1st group of groups contained by @flexgd, which may 276 * be a partial of a flex group. 277 * 278 * @sb: super block of fs to which the groups belongs 279 * 280 * Returns 0 on a successful allocation of the metadata blocks in the 281 * block group. 282 */ 283 static int ext4_alloc_group_tables(struct super_block *sb, 284 struct ext4_new_flex_group_data *flex_gd, 285 int flexbg_size) 286 { 287 struct ext4_new_group_data *group_data = flex_gd->groups; 288 ext4_fsblk_t start_blk; 289 ext4_fsblk_t last_blk; 290 ext4_group_t src_group; 291 ext4_group_t bb_index = 0; 292 ext4_group_t ib_index = 0; 293 ext4_group_t it_index = 0; 294 ext4_group_t group; 295 ext4_group_t last_group; 296 unsigned overhead; 297 __u16 uninit_mask = (flexbg_size > 1) ? ~EXT4_BG_BLOCK_UNINIT : ~0; 298 int i; 299 300 BUG_ON(flex_gd->count == 0 || group_data == NULL); 301 302 src_group = group_data[0].group; 303 last_group = src_group + flex_gd->count - 1; 304 305 BUG_ON((flexbg_size > 1) && ((src_group & ~(flexbg_size - 1)) != 306 (last_group & ~(flexbg_size - 1)))); 307 next_group: 308 group = group_data[0].group; 309 if (src_group >= group_data[0].group + flex_gd->count) 310 return -ENOSPC; 311 start_blk = ext4_group_first_block_no(sb, src_group); 312 last_blk = start_blk + group_data[src_group - group].blocks_count; 313 314 overhead = ext4_group_overhead_blocks(sb, src_group); 315 316 start_blk += overhead; 317 318 /* We collect contiguous blocks as much as possible. */ 319 src_group++; 320 for (; src_group <= last_group; src_group++) { 321 overhead = ext4_group_overhead_blocks(sb, src_group); 322 if (overhead == 0) 323 last_blk += group_data[src_group - group].blocks_count; 324 else 325 break; 326 } 327 328 /* Allocate block bitmaps */ 329 for (; bb_index < flex_gd->count; bb_index++) { 330 if (start_blk >= last_blk) 331 goto next_group; 332 group_data[bb_index].block_bitmap = start_blk++; 333 group = ext4_get_group_number(sb, start_blk - 1); 334 group -= group_data[0].group; 335 group_data[group].mdata_blocks++; 336 flex_gd->bg_flags[group] &= uninit_mask; 337 } 338 339 /* Allocate inode bitmaps */ 340 for (; ib_index < flex_gd->count; ib_index++) { 341 if (start_blk >= last_blk) 342 goto next_group; 343 group_data[ib_index].inode_bitmap = start_blk++; 344 group = ext4_get_group_number(sb, start_blk - 1); 345 group -= group_data[0].group; 346 group_data[group].mdata_blocks++; 347 flex_gd->bg_flags[group] &= uninit_mask; 348 } 349 350 /* Allocate inode tables */ 351 for (; it_index < flex_gd->count; it_index++) { 352 unsigned int itb = EXT4_SB(sb)->s_itb_per_group; 353 ext4_fsblk_t next_group_start; 354 355 if (start_blk + itb > last_blk) 356 goto next_group; 357 group_data[it_index].inode_table = start_blk; 358 group = ext4_get_group_number(sb, start_blk); 359 next_group_start = ext4_group_first_block_no(sb, group + 1); 360 group -= group_data[0].group; 361 362 if (start_blk + itb > next_group_start) { 363 flex_gd->bg_flags[group + 1] &= uninit_mask; 364 overhead = start_blk + itb - next_group_start; 365 group_data[group + 1].mdata_blocks += overhead; 366 itb -= overhead; 367 } 368 369 group_data[group].mdata_blocks += itb; 370 flex_gd->bg_flags[group] &= uninit_mask; 371 start_blk += EXT4_SB(sb)->s_itb_per_group; 372 } 373 374 /* Update free clusters count to exclude metadata blocks */ 375 for (i = 0; i < flex_gd->count; i++) { 376 group_data[i].free_clusters_count -= 377 EXT4_NUM_B2C(EXT4_SB(sb), 378 group_data[i].mdata_blocks); 379 } 380 381 if (test_opt(sb, DEBUG)) { 382 int i; 383 group = group_data[0].group; 384 385 printk(KERN_DEBUG "EXT4-fs: adding a flex group with " 386 "%d groups, flexbg size is %d:\n", flex_gd->count, 387 flexbg_size); 388 389 for (i = 0; i < flex_gd->count; i++) { 390 ext4_debug( 391 "adding %s group %u: %u blocks (%d free, %d mdata blocks)\n", 392 ext4_bg_has_super(sb, group + i) ? "normal" : 393 "no-super", group + i, 394 group_data[i].blocks_count, 395 group_data[i].free_clusters_count, 396 group_data[i].mdata_blocks); 397 } 398 } 399 return 0; 400 } 401 402 static struct buffer_head *bclean(handle_t *handle, struct super_block *sb, 403 ext4_fsblk_t blk) 404 { 405 struct buffer_head *bh; 406 int err; 407 408 bh = sb_getblk(sb, blk); 409 if (unlikely(!bh)) 410 return ERR_PTR(-ENOMEM); 411 BUFFER_TRACE(bh, "get_write_access"); 412 if ((err = ext4_journal_get_write_access(handle, bh))) { 413 brelse(bh); 414 bh = ERR_PTR(err); 415 } else { 416 memset(bh->b_data, 0, sb->s_blocksize); 417 set_buffer_uptodate(bh); 418 } 419 420 return bh; 421 } 422 423 static int ext4_resize_ensure_credits_batch(handle_t *handle, int credits) 424 { 425 return ext4_journal_ensure_credits_fn(handle, credits, 426 EXT4_MAX_TRANS_DATA, 0, 0); 427 } 428 429 /* 430 * set_flexbg_block_bitmap() mark clusters [@first_cluster, @last_cluster] used. 431 * 432 * Helper function for ext4_setup_new_group_blocks() which set . 433 * 434 * @sb: super block 435 * @handle: journal handle 436 * @flex_gd: flex group data 437 */ 438 static int set_flexbg_block_bitmap(struct super_block *sb, handle_t *handle, 439 struct ext4_new_flex_group_data *flex_gd, 440 ext4_fsblk_t first_cluster, ext4_fsblk_t last_cluster) 441 { 442 struct ext4_sb_info *sbi = EXT4_SB(sb); 443 ext4_group_t count = last_cluster - first_cluster + 1; 444 ext4_group_t count2; 445 446 ext4_debug("mark clusters [%llu-%llu] used\n", first_cluster, 447 last_cluster); 448 for (count2 = count; count > 0; 449 count -= count2, first_cluster += count2) { 450 ext4_fsblk_t start; 451 struct buffer_head *bh; 452 ext4_group_t group; 453 int err; 454 455 group = ext4_get_group_number(sb, EXT4_C2B(sbi, first_cluster)); 456 start = EXT4_B2C(sbi, ext4_group_first_block_no(sb, group)); 457 group -= flex_gd->groups[0].group; 458 459 count2 = EXT4_CLUSTERS_PER_GROUP(sb) - (first_cluster - start); 460 if (count2 > count) 461 count2 = count; 462 463 if (flex_gd->bg_flags[group] & EXT4_BG_BLOCK_UNINIT) { 464 BUG_ON(flex_gd->count > 1); 465 continue; 466 } 467 468 err = ext4_resize_ensure_credits_batch(handle, 1); 469 if (err < 0) 470 return err; 471 472 bh = sb_getblk(sb, flex_gd->groups[group].block_bitmap); 473 if (unlikely(!bh)) 474 return -ENOMEM; 475 476 BUFFER_TRACE(bh, "get_write_access"); 477 err = ext4_journal_get_write_access(handle, bh); 478 if (err) { 479 brelse(bh); 480 return err; 481 } 482 ext4_debug("mark block bitmap %#04llx (+%llu/%u)\n", 483 first_cluster, first_cluster - start, count2); 484 ext4_set_bits(bh->b_data, first_cluster - start, count2); 485 486 err = ext4_handle_dirty_metadata(handle, NULL, bh); 487 brelse(bh); 488 if (unlikely(err)) 489 return err; 490 } 491 492 return 0; 493 } 494 495 /* 496 * Set up the block and inode bitmaps, and the inode table for the new groups. 497 * This doesn't need to be part of the main transaction, since we are only 498 * changing blocks outside the actual filesystem. We still do journaling to 499 * ensure the recovery is correct in case of a failure just after resize. 500 * If any part of this fails, we simply abort the resize. 501 * 502 * setup_new_flex_group_blocks handles a flex group as follow: 503 * 1. copy super block and GDT, and initialize group tables if necessary. 504 * In this step, we only set bits in blocks bitmaps for blocks taken by 505 * super block and GDT. 506 * 2. allocate group tables in block bitmaps, that is, set bits in block 507 * bitmap for blocks taken by group tables. 508 */ 509 static int setup_new_flex_group_blocks(struct super_block *sb, 510 struct ext4_new_flex_group_data *flex_gd) 511 { 512 int group_table_count[] = {1, 1, EXT4_SB(sb)->s_itb_per_group}; 513 ext4_fsblk_t start; 514 ext4_fsblk_t block; 515 struct ext4_sb_info *sbi = EXT4_SB(sb); 516 struct ext4_super_block *es = sbi->s_es; 517 struct ext4_new_group_data *group_data = flex_gd->groups; 518 __u16 *bg_flags = flex_gd->bg_flags; 519 handle_t *handle; 520 ext4_group_t group, count; 521 struct buffer_head *bh = NULL; 522 int reserved_gdb, i, j, err = 0, err2; 523 int meta_bg; 524 525 BUG_ON(!flex_gd->count || !group_data || 526 group_data[0].group != sbi->s_groups_count); 527 528 reserved_gdb = le16_to_cpu(es->s_reserved_gdt_blocks); 529 meta_bg = ext4_has_feature_meta_bg(sb); 530 531 /* This transaction may be extended/restarted along the way */ 532 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, EXT4_MAX_TRANS_DATA); 533 if (IS_ERR(handle)) 534 return PTR_ERR(handle); 535 536 group = group_data[0].group; 537 for (i = 0; i < flex_gd->count; i++, group++) { 538 unsigned long gdblocks; 539 ext4_grpblk_t overhead; 540 541 gdblocks = ext4_bg_num_gdb(sb, group); 542 start = ext4_group_first_block_no(sb, group); 543 544 if (meta_bg == 0 && !ext4_bg_has_super(sb, group)) 545 goto handle_itb; 546 547 if (meta_bg == 1) { 548 ext4_group_t first_group; 549 first_group = ext4_meta_bg_first_group(sb, group); 550 if (first_group != group + 1 && 551 first_group != group + EXT4_DESC_PER_BLOCK(sb) - 1) 552 goto handle_itb; 553 } 554 555 block = start + ext4_bg_has_super(sb, group); 556 /* Copy all of the GDT blocks into the backup in this group */ 557 for (j = 0; j < gdblocks; j++, block++) { 558 struct buffer_head *gdb; 559 560 ext4_debug("update backup group %#04llx\n", block); 561 err = ext4_resize_ensure_credits_batch(handle, 1); 562 if (err < 0) 563 goto out; 564 565 gdb = sb_getblk(sb, block); 566 if (unlikely(!gdb)) { 567 err = -ENOMEM; 568 goto out; 569 } 570 571 BUFFER_TRACE(gdb, "get_write_access"); 572 err = ext4_journal_get_write_access(handle, gdb); 573 if (err) { 574 brelse(gdb); 575 goto out; 576 } 577 memcpy(gdb->b_data, sbi_array_rcu_deref(sbi, 578 s_group_desc, j)->b_data, gdb->b_size); 579 set_buffer_uptodate(gdb); 580 581 err = ext4_handle_dirty_metadata(handle, NULL, gdb); 582 if (unlikely(err)) { 583 brelse(gdb); 584 goto out; 585 } 586 brelse(gdb); 587 } 588 589 /* Zero out all of the reserved backup group descriptor 590 * table blocks 591 */ 592 if (ext4_bg_has_super(sb, group)) { 593 err = sb_issue_zeroout(sb, gdblocks + start + 1, 594 reserved_gdb, GFP_NOFS); 595 if (err) 596 goto out; 597 } 598 599 handle_itb: 600 /* Initialize group tables of the grop @group */ 601 if (!(bg_flags[i] & EXT4_BG_INODE_ZEROED)) 602 goto handle_bb; 603 604 /* Zero out all of the inode table blocks */ 605 block = group_data[i].inode_table; 606 ext4_debug("clear inode table blocks %#04llx -> %#04lx\n", 607 block, sbi->s_itb_per_group); 608 err = sb_issue_zeroout(sb, block, sbi->s_itb_per_group, 609 GFP_NOFS); 610 if (err) 611 goto out; 612 613 handle_bb: 614 if (bg_flags[i] & EXT4_BG_BLOCK_UNINIT) 615 goto handle_ib; 616 617 /* Initialize block bitmap of the @group */ 618 block = group_data[i].block_bitmap; 619 err = ext4_resize_ensure_credits_batch(handle, 1); 620 if (err < 0) 621 goto out; 622 623 bh = bclean(handle, sb, block); 624 if (IS_ERR(bh)) { 625 err = PTR_ERR(bh); 626 goto out; 627 } 628 overhead = ext4_group_overhead_blocks(sb, group); 629 if (overhead != 0) { 630 ext4_debug("mark backup superblock %#04llx (+0)\n", 631 start); 632 ext4_set_bits(bh->b_data, 0, 633 EXT4_NUM_B2C(sbi, overhead)); 634 } 635 ext4_mark_bitmap_end(EXT4_B2C(sbi, group_data[i].blocks_count), 636 sb->s_blocksize * 8, bh->b_data); 637 err = ext4_handle_dirty_metadata(handle, NULL, bh); 638 brelse(bh); 639 if (err) 640 goto out; 641 642 handle_ib: 643 if (bg_flags[i] & EXT4_BG_INODE_UNINIT) 644 continue; 645 646 /* Initialize inode bitmap of the @group */ 647 block = group_data[i].inode_bitmap; 648 err = ext4_resize_ensure_credits_batch(handle, 1); 649 if (err < 0) 650 goto out; 651 /* Mark unused entries in inode bitmap used */ 652 bh = bclean(handle, sb, block); 653 if (IS_ERR(bh)) { 654 err = PTR_ERR(bh); 655 goto out; 656 } 657 658 ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb), 659 sb->s_blocksize * 8, bh->b_data); 660 err = ext4_handle_dirty_metadata(handle, NULL, bh); 661 brelse(bh); 662 if (err) 663 goto out; 664 } 665 666 /* Mark group tables in block bitmap */ 667 for (j = 0; j < GROUP_TABLE_COUNT; j++) { 668 count = group_table_count[j]; 669 start = (&group_data[0].block_bitmap)[j]; 670 block = start; 671 for (i = 1; i < flex_gd->count; i++) { 672 block += group_table_count[j]; 673 if (block == (&group_data[i].block_bitmap)[j]) { 674 count += group_table_count[j]; 675 continue; 676 } 677 err = set_flexbg_block_bitmap(sb, handle, 678 flex_gd, 679 EXT4_B2C(sbi, start), 680 EXT4_B2C(sbi, 681 start + count 682 - 1)); 683 if (err) 684 goto out; 685 count = group_table_count[j]; 686 start = (&group_data[i].block_bitmap)[j]; 687 block = start; 688 } 689 690 if (count) { 691 err = set_flexbg_block_bitmap(sb, handle, 692 flex_gd, 693 EXT4_B2C(sbi, start), 694 EXT4_B2C(sbi, 695 start + count 696 - 1)); 697 if (err) 698 goto out; 699 } 700 } 701 702 out: 703 err2 = ext4_journal_stop(handle); 704 if (err2 && !err) 705 err = err2; 706 707 return err; 708 } 709 710 /* 711 * Iterate through the groups which hold BACKUP superblock/GDT copies in an 712 * ext4 filesystem. The counters should be initialized to 1, 5, and 7 before 713 * calling this for the first time. In a sparse filesystem it will be the 714 * sequence of powers of 3, 5, and 7: 1, 3, 5, 7, 9, 25, 27, 49, 81, ... 715 * For a non-sparse filesystem it will be every group: 1, 2, 3, 4, ... 716 */ 717 static unsigned ext4_list_backups(struct super_block *sb, unsigned *three, 718 unsigned *five, unsigned *seven) 719 { 720 unsigned *min = three; 721 int mult = 3; 722 unsigned ret; 723 724 if (!ext4_has_feature_sparse_super(sb)) { 725 ret = *min; 726 *min += 1; 727 return ret; 728 } 729 730 if (*five < *min) { 731 min = five; 732 mult = 5; 733 } 734 if (*seven < *min) { 735 min = seven; 736 mult = 7; 737 } 738 739 ret = *min; 740 *min *= mult; 741 742 return ret; 743 } 744 745 /* 746 * Check that all of the backup GDT blocks are held in the primary GDT block. 747 * It is assumed that they are stored in group order. Returns the number of 748 * groups in current filesystem that have BACKUPS, or -ve error code. 749 */ 750 static int verify_reserved_gdb(struct super_block *sb, 751 ext4_group_t end, 752 struct buffer_head *primary) 753 { 754 const ext4_fsblk_t blk = primary->b_blocknr; 755 unsigned three = 1; 756 unsigned five = 5; 757 unsigned seven = 7; 758 unsigned grp; 759 __le32 *p = (__le32 *)primary->b_data; 760 int gdbackups = 0; 761 762 while ((grp = ext4_list_backups(sb, &three, &five, &seven)) < end) { 763 if (le32_to_cpu(*p++) != 764 grp * EXT4_BLOCKS_PER_GROUP(sb) + blk){ 765 ext4_warning(sb, "reserved GDT %llu" 766 " missing grp %d (%llu)", 767 blk, grp, 768 grp * 769 (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) + 770 blk); 771 return -EINVAL; 772 } 773 if (++gdbackups > EXT4_ADDR_PER_BLOCK(sb)) 774 return -EFBIG; 775 } 776 777 return gdbackups; 778 } 779 780 /* 781 * Called when we need to bring a reserved group descriptor table block into 782 * use from the resize inode. The primary copy of the new GDT block currently 783 * is an indirect block (under the double indirect block in the resize inode). 784 * The new backup GDT blocks will be stored as leaf blocks in this indirect 785 * block, in group order. Even though we know all the block numbers we need, 786 * we check to ensure that the resize inode has actually reserved these blocks. 787 * 788 * Don't need to update the block bitmaps because the blocks are still in use. 789 * 790 * We get all of the error cases out of the way, so that we are sure to not 791 * fail once we start modifying the data on disk, because JBD has no rollback. 792 */ 793 static int add_new_gdb(handle_t *handle, struct inode *inode, 794 ext4_group_t group) 795 { 796 struct super_block *sb = inode->i_sb; 797 struct ext4_super_block *es = EXT4_SB(sb)->s_es; 798 unsigned long gdb_num = group / EXT4_DESC_PER_BLOCK(sb); 799 ext4_fsblk_t gdblock = EXT4_SB(sb)->s_sbh->b_blocknr + 1 + gdb_num; 800 struct buffer_head **o_group_desc, **n_group_desc = NULL; 801 struct buffer_head *dind = NULL; 802 struct buffer_head *gdb_bh = NULL; 803 int gdbackups; 804 struct ext4_iloc iloc = { .bh = NULL }; 805 __le32 *data; 806 int err; 807 808 if (test_opt(sb, DEBUG)) 809 printk(KERN_DEBUG 810 "EXT4-fs: ext4_add_new_gdb: adding group block %lu\n", 811 gdb_num); 812 813 gdb_bh = ext4_sb_bread(sb, gdblock, 0); 814 if (IS_ERR(gdb_bh)) 815 return PTR_ERR(gdb_bh); 816 817 gdbackups = verify_reserved_gdb(sb, group, gdb_bh); 818 if (gdbackups < 0) { 819 err = gdbackups; 820 goto errout; 821 } 822 823 data = EXT4_I(inode)->i_data + EXT4_DIND_BLOCK; 824 dind = ext4_sb_bread(sb, le32_to_cpu(*data), 0); 825 if (IS_ERR(dind)) { 826 err = PTR_ERR(dind); 827 dind = NULL; 828 goto errout; 829 } 830 831 data = (__le32 *)dind->b_data; 832 if (le32_to_cpu(data[gdb_num % EXT4_ADDR_PER_BLOCK(sb)]) != gdblock) { 833 ext4_warning(sb, "new group %u GDT block %llu not reserved", 834 group, gdblock); 835 err = -EINVAL; 836 goto errout; 837 } 838 839 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access"); 840 err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh); 841 if (unlikely(err)) 842 goto errout; 843 844 BUFFER_TRACE(gdb_bh, "get_write_access"); 845 err = ext4_journal_get_write_access(handle, gdb_bh); 846 if (unlikely(err)) 847 goto errout; 848 849 BUFFER_TRACE(dind, "get_write_access"); 850 err = ext4_journal_get_write_access(handle, dind); 851 if (unlikely(err)) { 852 ext4_std_error(sb, err); 853 goto errout; 854 } 855 856 /* ext4_reserve_inode_write() gets a reference on the iloc */ 857 err = ext4_reserve_inode_write(handle, inode, &iloc); 858 if (unlikely(err)) 859 goto errout; 860 861 n_group_desc = kvmalloc((gdb_num + 1) * sizeof(struct buffer_head *), 862 GFP_KERNEL); 863 if (!n_group_desc) { 864 err = -ENOMEM; 865 ext4_warning(sb, "not enough memory for %lu groups", 866 gdb_num + 1); 867 goto errout; 868 } 869 870 /* 871 * Finally, we have all of the possible failures behind us... 872 * 873 * Remove new GDT block from inode double-indirect block and clear out 874 * the new GDT block for use (which also "frees" the backup GDT blocks 875 * from the reserved inode). We don't need to change the bitmaps for 876 * these blocks, because they are marked as in-use from being in the 877 * reserved inode, and will become GDT blocks (primary and backup). 878 */ 879 data[gdb_num % EXT4_ADDR_PER_BLOCK(sb)] = 0; 880 err = ext4_handle_dirty_metadata(handle, NULL, dind); 881 if (unlikely(err)) { 882 ext4_std_error(sb, err); 883 goto errout; 884 } 885 inode->i_blocks -= (gdbackups + 1) * sb->s_blocksize >> 886 (9 - EXT4_SB(sb)->s_cluster_bits); 887 ext4_mark_iloc_dirty(handle, inode, &iloc); 888 memset(gdb_bh->b_data, 0, sb->s_blocksize); 889 err = ext4_handle_dirty_metadata(handle, NULL, gdb_bh); 890 if (unlikely(err)) { 891 ext4_std_error(sb, err); 892 iloc.bh = NULL; 893 goto errout; 894 } 895 brelse(dind); 896 897 rcu_read_lock(); 898 o_group_desc = rcu_dereference(EXT4_SB(sb)->s_group_desc); 899 memcpy(n_group_desc, o_group_desc, 900 EXT4_SB(sb)->s_gdb_count * sizeof(struct buffer_head *)); 901 rcu_read_unlock(); 902 n_group_desc[gdb_num] = gdb_bh; 903 rcu_assign_pointer(EXT4_SB(sb)->s_group_desc, n_group_desc); 904 EXT4_SB(sb)->s_gdb_count++; 905 ext4_kvfree_array_rcu(o_group_desc); 906 907 lock_buffer(EXT4_SB(sb)->s_sbh); 908 le16_add_cpu(&es->s_reserved_gdt_blocks, -1); 909 ext4_superblock_csum_set(sb); 910 unlock_buffer(EXT4_SB(sb)->s_sbh); 911 err = ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh); 912 if (err) 913 ext4_std_error(sb, err); 914 return err; 915 errout: 916 kvfree(n_group_desc); 917 brelse(iloc.bh); 918 brelse(dind); 919 brelse(gdb_bh); 920 921 ext4_debug("leaving with error %d\n", err); 922 return err; 923 } 924 925 /* 926 * add_new_gdb_meta_bg is the sister of add_new_gdb. 927 */ 928 static int add_new_gdb_meta_bg(struct super_block *sb, 929 handle_t *handle, ext4_group_t group) { 930 ext4_fsblk_t gdblock; 931 struct buffer_head *gdb_bh; 932 struct buffer_head **o_group_desc, **n_group_desc; 933 unsigned long gdb_num = group / EXT4_DESC_PER_BLOCK(sb); 934 int err; 935 936 gdblock = ext4_meta_bg_first_block_no(sb, group) + 937 ext4_bg_has_super(sb, group); 938 gdb_bh = ext4_sb_bread(sb, gdblock, 0); 939 if (IS_ERR(gdb_bh)) 940 return PTR_ERR(gdb_bh); 941 n_group_desc = kvmalloc((gdb_num + 1) * sizeof(struct buffer_head *), 942 GFP_KERNEL); 943 if (!n_group_desc) { 944 brelse(gdb_bh); 945 err = -ENOMEM; 946 ext4_warning(sb, "not enough memory for %lu groups", 947 gdb_num + 1); 948 return err; 949 } 950 951 rcu_read_lock(); 952 o_group_desc = rcu_dereference(EXT4_SB(sb)->s_group_desc); 953 memcpy(n_group_desc, o_group_desc, 954 EXT4_SB(sb)->s_gdb_count * sizeof(struct buffer_head *)); 955 rcu_read_unlock(); 956 n_group_desc[gdb_num] = gdb_bh; 957 958 BUFFER_TRACE(gdb_bh, "get_write_access"); 959 err = ext4_journal_get_write_access(handle, gdb_bh); 960 if (err) { 961 kvfree(n_group_desc); 962 brelse(gdb_bh); 963 return err; 964 } 965 966 rcu_assign_pointer(EXT4_SB(sb)->s_group_desc, n_group_desc); 967 EXT4_SB(sb)->s_gdb_count++; 968 ext4_kvfree_array_rcu(o_group_desc); 969 return err; 970 } 971 972 /* 973 * Called when we are adding a new group which has a backup copy of each of 974 * the GDT blocks (i.e. sparse group) and there are reserved GDT blocks. 975 * We need to add these reserved backup GDT blocks to the resize inode, so 976 * that they are kept for future resizing and not allocated to files. 977 * 978 * Each reserved backup GDT block will go into a different indirect block. 979 * The indirect blocks are actually the primary reserved GDT blocks, 980 * so we know in advance what their block numbers are. We only get the 981 * double-indirect block to verify it is pointing to the primary reserved 982 * GDT blocks so we don't overwrite a data block by accident. The reserved 983 * backup GDT blocks are stored in their reserved primary GDT block. 984 */ 985 static int reserve_backup_gdb(handle_t *handle, struct inode *inode, 986 ext4_group_t group) 987 { 988 struct super_block *sb = inode->i_sb; 989 int reserved_gdb =le16_to_cpu(EXT4_SB(sb)->s_es->s_reserved_gdt_blocks); 990 int cluster_bits = EXT4_SB(sb)->s_cluster_bits; 991 struct buffer_head **primary; 992 struct buffer_head *dind; 993 struct ext4_iloc iloc; 994 ext4_fsblk_t blk; 995 __le32 *data, *end; 996 int gdbackups = 0; 997 int res, i; 998 int err; 999 1000 primary = kmalloc_array(reserved_gdb, sizeof(*primary), GFP_NOFS); 1001 if (!primary) 1002 return -ENOMEM; 1003 1004 data = EXT4_I(inode)->i_data + EXT4_DIND_BLOCK; 1005 dind = ext4_sb_bread(sb, le32_to_cpu(*data), 0); 1006 if (IS_ERR(dind)) { 1007 err = PTR_ERR(dind); 1008 dind = NULL; 1009 goto exit_free; 1010 } 1011 1012 blk = EXT4_SB(sb)->s_sbh->b_blocknr + 1 + EXT4_SB(sb)->s_gdb_count; 1013 data = (__le32 *)dind->b_data + (EXT4_SB(sb)->s_gdb_count % 1014 EXT4_ADDR_PER_BLOCK(sb)); 1015 end = (__le32 *)dind->b_data + EXT4_ADDR_PER_BLOCK(sb); 1016 1017 /* Get each reserved primary GDT block and verify it holds backups */ 1018 for (res = 0; res < reserved_gdb; res++, blk++) { 1019 if (le32_to_cpu(*data) != blk) { 1020 ext4_warning(sb, "reserved block %llu" 1021 " not at offset %ld", 1022 blk, 1023 (long)(data - (__le32 *)dind->b_data)); 1024 err = -EINVAL; 1025 goto exit_bh; 1026 } 1027 primary[res] = ext4_sb_bread(sb, blk, 0); 1028 if (IS_ERR(primary[res])) { 1029 err = PTR_ERR(primary[res]); 1030 primary[res] = NULL; 1031 goto exit_bh; 1032 } 1033 gdbackups = verify_reserved_gdb(sb, group, primary[res]); 1034 if (gdbackups < 0) { 1035 brelse(primary[res]); 1036 err = gdbackups; 1037 goto exit_bh; 1038 } 1039 if (++data >= end) 1040 data = (__le32 *)dind->b_data; 1041 } 1042 1043 for (i = 0; i < reserved_gdb; i++) { 1044 BUFFER_TRACE(primary[i], "get_write_access"); 1045 if ((err = ext4_journal_get_write_access(handle, primary[i]))) 1046 goto exit_bh; 1047 } 1048 1049 if ((err = ext4_reserve_inode_write(handle, inode, &iloc))) 1050 goto exit_bh; 1051 1052 /* 1053 * Finally we can add each of the reserved backup GDT blocks from 1054 * the new group to its reserved primary GDT block. 1055 */ 1056 blk = group * EXT4_BLOCKS_PER_GROUP(sb); 1057 for (i = 0; i < reserved_gdb; i++) { 1058 int err2; 1059 data = (__le32 *)primary[i]->b_data; 1060 /* printk("reserving backup %lu[%u] = %lu\n", 1061 primary[i]->b_blocknr, gdbackups, 1062 blk + primary[i]->b_blocknr); */ 1063 data[gdbackups] = cpu_to_le32(blk + primary[i]->b_blocknr); 1064 err2 = ext4_handle_dirty_metadata(handle, NULL, primary[i]); 1065 if (!err) 1066 err = err2; 1067 } 1068 1069 inode->i_blocks += reserved_gdb * sb->s_blocksize >> (9 - cluster_bits); 1070 ext4_mark_iloc_dirty(handle, inode, &iloc); 1071 1072 exit_bh: 1073 while (--res >= 0) 1074 brelse(primary[res]); 1075 brelse(dind); 1076 1077 exit_free: 1078 kfree(primary); 1079 1080 return err; 1081 } 1082 1083 /* 1084 * Update the backup copies of the ext4 metadata. These don't need to be part 1085 * of the main resize transaction, because e2fsck will re-write them if there 1086 * is a problem (basically only OOM will cause a problem). However, we 1087 * _should_ update the backups if possible, in case the primary gets trashed 1088 * for some reason and we need to run e2fsck from a backup superblock. The 1089 * important part is that the new block and inode counts are in the backup 1090 * superblocks, and the location of the new group metadata in the GDT backups. 1091 * 1092 * We do not need take the s_resize_lock for this, because these 1093 * blocks are not otherwise touched by the filesystem code when it is 1094 * mounted. We don't need to worry about last changing from 1095 * sbi->s_groups_count, because the worst that can happen is that we 1096 * do not copy the full number of backups at this time. The resize 1097 * which changed s_groups_count will backup again. 1098 */ 1099 static void update_backups(struct super_block *sb, sector_t blk_off, char *data, 1100 int size, int meta_bg) 1101 { 1102 struct ext4_sb_info *sbi = EXT4_SB(sb); 1103 ext4_group_t last; 1104 const int bpg = EXT4_BLOCKS_PER_GROUP(sb); 1105 unsigned three = 1; 1106 unsigned five = 5; 1107 unsigned seven = 7; 1108 ext4_group_t group = 0; 1109 int rest = sb->s_blocksize - size; 1110 handle_t *handle; 1111 int err = 0, err2; 1112 1113 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, EXT4_MAX_TRANS_DATA); 1114 if (IS_ERR(handle)) { 1115 group = 1; 1116 err = PTR_ERR(handle); 1117 goto exit_err; 1118 } 1119 1120 if (meta_bg == 0) { 1121 group = ext4_list_backups(sb, &three, &five, &seven); 1122 last = sbi->s_groups_count; 1123 } else { 1124 group = ext4_get_group_number(sb, blk_off) + 1; 1125 last = (ext4_group_t)(group + EXT4_DESC_PER_BLOCK(sb) - 2); 1126 } 1127 1128 while (group < sbi->s_groups_count) { 1129 struct buffer_head *bh; 1130 ext4_fsblk_t backup_block; 1131 1132 /* Out of journal space, and can't get more - abort - so sad */ 1133 err = ext4_resize_ensure_credits_batch(handle, 1); 1134 if (err < 0) 1135 break; 1136 1137 if (meta_bg == 0) 1138 backup_block = ((ext4_fsblk_t)group) * bpg + blk_off; 1139 else 1140 backup_block = (ext4_group_first_block_no(sb, group) + 1141 ext4_bg_has_super(sb, group)); 1142 1143 bh = sb_getblk(sb, backup_block); 1144 if (unlikely(!bh)) { 1145 err = -ENOMEM; 1146 break; 1147 } 1148 ext4_debug("update metadata backup %llu(+%llu)\n", 1149 backup_block, backup_block - 1150 ext4_group_first_block_no(sb, group)); 1151 BUFFER_TRACE(bh, "get_write_access"); 1152 if ((err = ext4_journal_get_write_access(handle, bh))) { 1153 brelse(bh); 1154 break; 1155 } 1156 lock_buffer(bh); 1157 memcpy(bh->b_data, data, size); 1158 if (rest) 1159 memset(bh->b_data + size, 0, rest); 1160 set_buffer_uptodate(bh); 1161 unlock_buffer(bh); 1162 err = ext4_handle_dirty_metadata(handle, NULL, bh); 1163 if (unlikely(err)) 1164 ext4_std_error(sb, err); 1165 brelse(bh); 1166 1167 if (meta_bg == 0) 1168 group = ext4_list_backups(sb, &three, &five, &seven); 1169 else if (group == last) 1170 break; 1171 else 1172 group = last; 1173 } 1174 if ((err2 = ext4_journal_stop(handle)) && !err) 1175 err = err2; 1176 1177 /* 1178 * Ugh! Need to have e2fsck write the backup copies. It is too 1179 * late to revert the resize, we shouldn't fail just because of 1180 * the backup copies (they are only needed in case of corruption). 1181 * 1182 * However, if we got here we have a journal problem too, so we 1183 * can't really start a transaction to mark the superblock. 1184 * Chicken out and just set the flag on the hope it will be written 1185 * to disk, and if not - we will simply wait until next fsck. 1186 */ 1187 exit_err: 1188 if (err) { 1189 ext4_warning(sb, "can't update backup for group %u (err %d), " 1190 "forcing fsck on next reboot", group, err); 1191 sbi->s_mount_state &= ~EXT4_VALID_FS; 1192 sbi->s_es->s_state &= cpu_to_le16(~EXT4_VALID_FS); 1193 mark_buffer_dirty(sbi->s_sbh); 1194 } 1195 } 1196 1197 /* 1198 * ext4_add_new_descs() adds @count group descriptor of groups 1199 * starting at @group 1200 * 1201 * @handle: journal handle 1202 * @sb: super block 1203 * @group: the group no. of the first group desc to be added 1204 * @resize_inode: the resize inode 1205 * @count: number of group descriptors to be added 1206 */ 1207 static int ext4_add_new_descs(handle_t *handle, struct super_block *sb, 1208 ext4_group_t group, struct inode *resize_inode, 1209 ext4_group_t count) 1210 { 1211 struct ext4_sb_info *sbi = EXT4_SB(sb); 1212 struct ext4_super_block *es = sbi->s_es; 1213 struct buffer_head *gdb_bh; 1214 int i, gdb_off, gdb_num, err = 0; 1215 int meta_bg; 1216 1217 meta_bg = ext4_has_feature_meta_bg(sb); 1218 for (i = 0; i < count; i++, group++) { 1219 int reserved_gdb = ext4_bg_has_super(sb, group) ? 1220 le16_to_cpu(es->s_reserved_gdt_blocks) : 0; 1221 1222 gdb_off = group % EXT4_DESC_PER_BLOCK(sb); 1223 gdb_num = group / EXT4_DESC_PER_BLOCK(sb); 1224 1225 /* 1226 * We will only either add reserved group blocks to a backup group 1227 * or remove reserved blocks for the first group in a new group block. 1228 * Doing both would be mean more complex code, and sane people don't 1229 * use non-sparse filesystems anymore. This is already checked above. 1230 */ 1231 if (gdb_off) { 1232 gdb_bh = sbi_array_rcu_deref(sbi, s_group_desc, 1233 gdb_num); 1234 BUFFER_TRACE(gdb_bh, "get_write_access"); 1235 err = ext4_journal_get_write_access(handle, gdb_bh); 1236 1237 if (!err && reserved_gdb && ext4_bg_num_gdb(sb, group)) 1238 err = reserve_backup_gdb(handle, resize_inode, group); 1239 } else if (meta_bg != 0) { 1240 err = add_new_gdb_meta_bg(sb, handle, group); 1241 } else { 1242 err = add_new_gdb(handle, resize_inode, group); 1243 } 1244 if (err) 1245 break; 1246 } 1247 return err; 1248 } 1249 1250 static struct buffer_head *ext4_get_bitmap(struct super_block *sb, __u64 block) 1251 { 1252 struct buffer_head *bh = sb_getblk(sb, block); 1253 if (unlikely(!bh)) 1254 return NULL; 1255 if (!bh_uptodate_or_lock(bh)) { 1256 if (ext4_read_bh(bh, 0, NULL) < 0) { 1257 brelse(bh); 1258 return NULL; 1259 } 1260 } 1261 1262 return bh; 1263 } 1264 1265 static int ext4_set_bitmap_checksums(struct super_block *sb, 1266 ext4_group_t group, 1267 struct ext4_group_desc *gdp, 1268 struct ext4_new_group_data *group_data) 1269 { 1270 struct buffer_head *bh; 1271 1272 if (!ext4_has_metadata_csum(sb)) 1273 return 0; 1274 1275 bh = ext4_get_bitmap(sb, group_data->inode_bitmap); 1276 if (!bh) 1277 return -EIO; 1278 ext4_inode_bitmap_csum_set(sb, group, gdp, bh, 1279 EXT4_INODES_PER_GROUP(sb) / 8); 1280 brelse(bh); 1281 1282 bh = ext4_get_bitmap(sb, group_data->block_bitmap); 1283 if (!bh) 1284 return -EIO; 1285 ext4_block_bitmap_csum_set(sb, group, gdp, bh); 1286 brelse(bh); 1287 1288 return 0; 1289 } 1290 1291 /* 1292 * ext4_setup_new_descs() will set up the group descriptor descriptors of a flex bg 1293 */ 1294 static int ext4_setup_new_descs(handle_t *handle, struct super_block *sb, 1295 struct ext4_new_flex_group_data *flex_gd) 1296 { 1297 struct ext4_new_group_data *group_data = flex_gd->groups; 1298 struct ext4_group_desc *gdp; 1299 struct ext4_sb_info *sbi = EXT4_SB(sb); 1300 struct buffer_head *gdb_bh; 1301 ext4_group_t group; 1302 __u16 *bg_flags = flex_gd->bg_flags; 1303 int i, gdb_off, gdb_num, err = 0; 1304 1305 1306 for (i = 0; i < flex_gd->count; i++, group_data++, bg_flags++) { 1307 group = group_data->group; 1308 1309 gdb_off = group % EXT4_DESC_PER_BLOCK(sb); 1310 gdb_num = group / EXT4_DESC_PER_BLOCK(sb); 1311 1312 /* 1313 * get_write_access() has been called on gdb_bh by ext4_add_new_desc(). 1314 */ 1315 gdb_bh = sbi_array_rcu_deref(sbi, s_group_desc, gdb_num); 1316 /* Update group descriptor block for new group */ 1317 gdp = (struct ext4_group_desc *)(gdb_bh->b_data + 1318 gdb_off * EXT4_DESC_SIZE(sb)); 1319 1320 memset(gdp, 0, EXT4_DESC_SIZE(sb)); 1321 ext4_block_bitmap_set(sb, gdp, group_data->block_bitmap); 1322 ext4_inode_bitmap_set(sb, gdp, group_data->inode_bitmap); 1323 err = ext4_set_bitmap_checksums(sb, group, gdp, group_data); 1324 if (err) { 1325 ext4_std_error(sb, err); 1326 break; 1327 } 1328 1329 ext4_inode_table_set(sb, gdp, group_data->inode_table); 1330 ext4_free_group_clusters_set(sb, gdp, 1331 group_data->free_clusters_count); 1332 ext4_free_inodes_set(sb, gdp, EXT4_INODES_PER_GROUP(sb)); 1333 if (ext4_has_group_desc_csum(sb)) 1334 ext4_itable_unused_set(sb, gdp, 1335 EXT4_INODES_PER_GROUP(sb)); 1336 gdp->bg_flags = cpu_to_le16(*bg_flags); 1337 ext4_group_desc_csum_set(sb, group, gdp); 1338 1339 err = ext4_handle_dirty_metadata(handle, NULL, gdb_bh); 1340 if (unlikely(err)) { 1341 ext4_std_error(sb, err); 1342 break; 1343 } 1344 1345 /* 1346 * We can allocate memory for mb_alloc based on the new group 1347 * descriptor 1348 */ 1349 err = ext4_mb_add_groupinfo(sb, group, gdp); 1350 if (err) 1351 break; 1352 } 1353 return err; 1354 } 1355 1356 /* 1357 * ext4_update_super() updates the super block so that the newly added 1358 * groups can be seen by the filesystem. 1359 * 1360 * @sb: super block 1361 * @flex_gd: new added groups 1362 */ 1363 static void ext4_update_super(struct super_block *sb, 1364 struct ext4_new_flex_group_data *flex_gd) 1365 { 1366 ext4_fsblk_t blocks_count = 0; 1367 ext4_fsblk_t free_blocks = 0; 1368 ext4_fsblk_t reserved_blocks = 0; 1369 struct ext4_new_group_data *group_data = flex_gd->groups; 1370 struct ext4_sb_info *sbi = EXT4_SB(sb); 1371 struct ext4_super_block *es = sbi->s_es; 1372 int i; 1373 1374 BUG_ON(flex_gd->count == 0 || group_data == NULL); 1375 /* 1376 * Make the new blocks and inodes valid next. We do this before 1377 * increasing the group count so that once the group is enabled, 1378 * all of its blocks and inodes are already valid. 1379 * 1380 * We always allocate group-by-group, then block-by-block or 1381 * inode-by-inode within a group, so enabling these 1382 * blocks/inodes before the group is live won't actually let us 1383 * allocate the new space yet. 1384 */ 1385 for (i = 0; i < flex_gd->count; i++) { 1386 blocks_count += group_data[i].blocks_count; 1387 free_blocks += EXT4_C2B(sbi, group_data[i].free_clusters_count); 1388 } 1389 1390 reserved_blocks = ext4_r_blocks_count(es) * 100; 1391 reserved_blocks = div64_u64(reserved_blocks, ext4_blocks_count(es)); 1392 reserved_blocks *= blocks_count; 1393 do_div(reserved_blocks, 100); 1394 1395 lock_buffer(sbi->s_sbh); 1396 ext4_blocks_count_set(es, ext4_blocks_count(es) + blocks_count); 1397 ext4_free_blocks_count_set(es, ext4_free_blocks_count(es) + free_blocks); 1398 le32_add_cpu(&es->s_inodes_count, EXT4_INODES_PER_GROUP(sb) * 1399 flex_gd->count); 1400 le32_add_cpu(&es->s_free_inodes_count, EXT4_INODES_PER_GROUP(sb) * 1401 flex_gd->count); 1402 1403 ext4_debug("free blocks count %llu", ext4_free_blocks_count(es)); 1404 /* 1405 * We need to protect s_groups_count against other CPUs seeing 1406 * inconsistent state in the superblock. 1407 * 1408 * The precise rules we use are: 1409 * 1410 * * Writers must perform a smp_wmb() after updating all 1411 * dependent data and before modifying the groups count 1412 * 1413 * * Readers must perform an smp_rmb() after reading the groups 1414 * count and before reading any dependent data. 1415 * 1416 * NB. These rules can be relaxed when checking the group count 1417 * while freeing data, as we can only allocate from a block 1418 * group after serialising against the group count, and we can 1419 * only then free after serialising in turn against that 1420 * allocation. 1421 */ 1422 smp_wmb(); 1423 1424 /* Update the global fs size fields */ 1425 sbi->s_groups_count += flex_gd->count; 1426 sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count, 1427 (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb))); 1428 1429 /* Update the reserved block counts only once the new group is 1430 * active. */ 1431 ext4_r_blocks_count_set(es, ext4_r_blocks_count(es) + 1432 reserved_blocks); 1433 ext4_superblock_csum_set(sb); 1434 unlock_buffer(sbi->s_sbh); 1435 1436 /* Update the free space counts */ 1437 percpu_counter_add(&sbi->s_freeclusters_counter, 1438 EXT4_NUM_B2C(sbi, free_blocks)); 1439 percpu_counter_add(&sbi->s_freeinodes_counter, 1440 EXT4_INODES_PER_GROUP(sb) * flex_gd->count); 1441 1442 ext4_debug("free blocks count %llu", 1443 percpu_counter_read(&sbi->s_freeclusters_counter)); 1444 if (ext4_has_feature_flex_bg(sb) && sbi->s_log_groups_per_flex) { 1445 ext4_group_t flex_group; 1446 struct flex_groups *fg; 1447 1448 flex_group = ext4_flex_group(sbi, group_data[0].group); 1449 fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group); 1450 atomic64_add(EXT4_NUM_B2C(sbi, free_blocks), 1451 &fg->free_clusters); 1452 atomic_add(EXT4_INODES_PER_GROUP(sb) * flex_gd->count, 1453 &fg->free_inodes); 1454 } 1455 1456 /* 1457 * Update the fs overhead information 1458 */ 1459 ext4_calculate_overhead(sb); 1460 1461 if (test_opt(sb, DEBUG)) 1462 printk(KERN_DEBUG "EXT4-fs: added group %u:" 1463 "%llu blocks(%llu free %llu reserved)\n", flex_gd->count, 1464 blocks_count, free_blocks, reserved_blocks); 1465 } 1466 1467 /* Add a flex group to an fs. Ensure we handle all possible error conditions 1468 * _before_ we start modifying the filesystem, because we cannot abort the 1469 * transaction and not have it write the data to disk. 1470 */ 1471 static int ext4_flex_group_add(struct super_block *sb, 1472 struct inode *resize_inode, 1473 struct ext4_new_flex_group_data *flex_gd) 1474 { 1475 struct ext4_sb_info *sbi = EXT4_SB(sb); 1476 struct ext4_super_block *es = sbi->s_es; 1477 ext4_fsblk_t o_blocks_count; 1478 ext4_grpblk_t last; 1479 ext4_group_t group; 1480 handle_t *handle; 1481 unsigned reserved_gdb; 1482 int err = 0, err2 = 0, credit; 1483 1484 BUG_ON(!flex_gd->count || !flex_gd->groups || !flex_gd->bg_flags); 1485 1486 reserved_gdb = le16_to_cpu(es->s_reserved_gdt_blocks); 1487 o_blocks_count = ext4_blocks_count(es); 1488 ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last); 1489 BUG_ON(last); 1490 1491 err = setup_new_flex_group_blocks(sb, flex_gd); 1492 if (err) 1493 goto exit; 1494 /* 1495 * We will always be modifying at least the superblock and GDT 1496 * blocks. If we are adding a group past the last current GDT block, 1497 * we will also modify the inode and the dindirect block. If we 1498 * are adding a group with superblock/GDT backups we will also 1499 * modify each of the reserved GDT dindirect blocks. 1500 */ 1501 credit = 3; /* sb, resize inode, resize inode dindirect */ 1502 /* GDT blocks */ 1503 credit += 1 + DIV_ROUND_UP(flex_gd->count, EXT4_DESC_PER_BLOCK(sb)); 1504 credit += reserved_gdb; /* Reserved GDT dindirect blocks */ 1505 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, credit); 1506 if (IS_ERR(handle)) { 1507 err = PTR_ERR(handle); 1508 goto exit; 1509 } 1510 1511 BUFFER_TRACE(sbi->s_sbh, "get_write_access"); 1512 err = ext4_journal_get_write_access(handle, sbi->s_sbh); 1513 if (err) 1514 goto exit_journal; 1515 1516 group = flex_gd->groups[0].group; 1517 BUG_ON(group != sbi->s_groups_count); 1518 err = ext4_add_new_descs(handle, sb, group, 1519 resize_inode, flex_gd->count); 1520 if (err) 1521 goto exit_journal; 1522 1523 err = ext4_setup_new_descs(handle, sb, flex_gd); 1524 if (err) 1525 goto exit_journal; 1526 1527 ext4_update_super(sb, flex_gd); 1528 1529 err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh); 1530 1531 exit_journal: 1532 err2 = ext4_journal_stop(handle); 1533 if (!err) 1534 err = err2; 1535 1536 if (!err) { 1537 int gdb_num = group / EXT4_DESC_PER_BLOCK(sb); 1538 int gdb_num_end = ((group + flex_gd->count - 1) / 1539 EXT4_DESC_PER_BLOCK(sb)); 1540 int meta_bg = ext4_has_feature_meta_bg(sb); 1541 sector_t old_gdb = 0; 1542 1543 update_backups(sb, sbi->s_sbh->b_blocknr, (char *)es, 1544 sizeof(struct ext4_super_block), 0); 1545 for (; gdb_num <= gdb_num_end; gdb_num++) { 1546 struct buffer_head *gdb_bh; 1547 1548 gdb_bh = sbi_array_rcu_deref(sbi, s_group_desc, 1549 gdb_num); 1550 if (old_gdb == gdb_bh->b_blocknr) 1551 continue; 1552 update_backups(sb, gdb_bh->b_blocknr, gdb_bh->b_data, 1553 gdb_bh->b_size, meta_bg); 1554 old_gdb = gdb_bh->b_blocknr; 1555 } 1556 } 1557 exit: 1558 return err; 1559 } 1560 1561 static int ext4_setup_next_flex_gd(struct super_block *sb, 1562 struct ext4_new_flex_group_data *flex_gd, 1563 ext4_fsblk_t n_blocks_count, 1564 unsigned long flexbg_size) 1565 { 1566 struct ext4_sb_info *sbi = EXT4_SB(sb); 1567 struct ext4_super_block *es = sbi->s_es; 1568 struct ext4_new_group_data *group_data = flex_gd->groups; 1569 ext4_fsblk_t o_blocks_count; 1570 ext4_group_t n_group; 1571 ext4_group_t group; 1572 ext4_group_t last_group; 1573 ext4_grpblk_t last; 1574 ext4_grpblk_t clusters_per_group; 1575 unsigned long i; 1576 1577 clusters_per_group = EXT4_CLUSTERS_PER_GROUP(sb); 1578 1579 o_blocks_count = ext4_blocks_count(es); 1580 1581 if (o_blocks_count == n_blocks_count) 1582 return 0; 1583 1584 ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last); 1585 BUG_ON(last); 1586 ext4_get_group_no_and_offset(sb, n_blocks_count - 1, &n_group, &last); 1587 1588 last_group = group | (flexbg_size - 1); 1589 if (last_group > n_group) 1590 last_group = n_group; 1591 1592 flex_gd->count = last_group - group + 1; 1593 1594 for (i = 0; i < flex_gd->count; i++) { 1595 int overhead; 1596 1597 group_data[i].group = group + i; 1598 group_data[i].blocks_count = EXT4_BLOCKS_PER_GROUP(sb); 1599 overhead = ext4_group_overhead_blocks(sb, group + i); 1600 group_data[i].mdata_blocks = overhead; 1601 group_data[i].free_clusters_count = EXT4_CLUSTERS_PER_GROUP(sb); 1602 if (ext4_has_group_desc_csum(sb)) { 1603 flex_gd->bg_flags[i] = EXT4_BG_BLOCK_UNINIT | 1604 EXT4_BG_INODE_UNINIT; 1605 if (!test_opt(sb, INIT_INODE_TABLE)) 1606 flex_gd->bg_flags[i] |= EXT4_BG_INODE_ZEROED; 1607 } else 1608 flex_gd->bg_flags[i] = EXT4_BG_INODE_ZEROED; 1609 } 1610 1611 if (last_group == n_group && ext4_has_group_desc_csum(sb)) 1612 /* We need to initialize block bitmap of last group. */ 1613 flex_gd->bg_flags[i - 1] &= ~EXT4_BG_BLOCK_UNINIT; 1614 1615 if ((last_group == n_group) && (last != clusters_per_group - 1)) { 1616 group_data[i - 1].blocks_count = EXT4_C2B(sbi, last + 1); 1617 group_data[i - 1].free_clusters_count -= clusters_per_group - 1618 last - 1; 1619 } 1620 1621 return 1; 1622 } 1623 1624 /* Add group descriptor data to an existing or new group descriptor block. 1625 * Ensure we handle all possible error conditions _before_ we start modifying 1626 * the filesystem, because we cannot abort the transaction and not have it 1627 * write the data to disk. 1628 * 1629 * If we are on a GDT block boundary, we need to get the reserved GDT block. 1630 * Otherwise, we may need to add backup GDT blocks for a sparse group. 1631 * 1632 * We only need to hold the superblock lock while we are actually adding 1633 * in the new group's counts to the superblock. Prior to that we have 1634 * not really "added" the group at all. We re-check that we are still 1635 * adding in the last group in case things have changed since verifying. 1636 */ 1637 int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input) 1638 { 1639 struct ext4_new_flex_group_data flex_gd; 1640 struct ext4_sb_info *sbi = EXT4_SB(sb); 1641 struct ext4_super_block *es = sbi->s_es; 1642 int reserved_gdb = ext4_bg_has_super(sb, input->group) ? 1643 le16_to_cpu(es->s_reserved_gdt_blocks) : 0; 1644 struct inode *inode = NULL; 1645 int gdb_off; 1646 int err; 1647 __u16 bg_flags = 0; 1648 1649 gdb_off = input->group % EXT4_DESC_PER_BLOCK(sb); 1650 1651 if (gdb_off == 0 && !ext4_has_feature_sparse_super(sb)) { 1652 ext4_warning(sb, "Can't resize non-sparse filesystem further"); 1653 return -EPERM; 1654 } 1655 1656 if (ext4_blocks_count(es) + input->blocks_count < 1657 ext4_blocks_count(es)) { 1658 ext4_warning(sb, "blocks_count overflow"); 1659 return -EINVAL; 1660 } 1661 1662 if (le32_to_cpu(es->s_inodes_count) + EXT4_INODES_PER_GROUP(sb) < 1663 le32_to_cpu(es->s_inodes_count)) { 1664 ext4_warning(sb, "inodes_count overflow"); 1665 return -EINVAL; 1666 } 1667 1668 if (reserved_gdb || gdb_off == 0) { 1669 if (!ext4_has_feature_resize_inode(sb) || 1670 !le16_to_cpu(es->s_reserved_gdt_blocks)) { 1671 ext4_warning(sb, 1672 "No reserved GDT blocks, can't resize"); 1673 return -EPERM; 1674 } 1675 inode = ext4_iget(sb, EXT4_RESIZE_INO, EXT4_IGET_SPECIAL); 1676 if (IS_ERR(inode)) { 1677 ext4_warning(sb, "Error opening resize inode"); 1678 return PTR_ERR(inode); 1679 } 1680 } 1681 1682 1683 err = verify_group_input(sb, input); 1684 if (err) 1685 goto out; 1686 1687 err = ext4_alloc_flex_bg_array(sb, input->group + 1); 1688 if (err) 1689 goto out; 1690 1691 err = ext4_mb_alloc_groupinfo(sb, input->group + 1); 1692 if (err) 1693 goto out; 1694 1695 flex_gd.count = 1; 1696 flex_gd.groups = input; 1697 flex_gd.bg_flags = &bg_flags; 1698 err = ext4_flex_group_add(sb, inode, &flex_gd); 1699 out: 1700 iput(inode); 1701 return err; 1702 } /* ext4_group_add */ 1703 1704 /* 1705 * extend a group without checking assuming that checking has been done. 1706 */ 1707 static int ext4_group_extend_no_check(struct super_block *sb, 1708 ext4_fsblk_t o_blocks_count, ext4_grpblk_t add) 1709 { 1710 struct ext4_super_block *es = EXT4_SB(sb)->s_es; 1711 handle_t *handle; 1712 int err = 0, err2; 1713 1714 /* We will update the superblock, one block bitmap, and 1715 * one group descriptor via ext4_group_add_blocks(). 1716 */ 1717 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, 3); 1718 if (IS_ERR(handle)) { 1719 err = PTR_ERR(handle); 1720 ext4_warning(sb, "error %d on journal start", err); 1721 return err; 1722 } 1723 1724 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access"); 1725 err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh); 1726 if (err) { 1727 ext4_warning(sb, "error %d on journal write access", err); 1728 goto errout; 1729 } 1730 1731 lock_buffer(EXT4_SB(sb)->s_sbh); 1732 ext4_blocks_count_set(es, o_blocks_count + add); 1733 ext4_free_blocks_count_set(es, ext4_free_blocks_count(es) + add); 1734 ext4_superblock_csum_set(sb); 1735 unlock_buffer(EXT4_SB(sb)->s_sbh); 1736 ext4_debug("freeing blocks %llu through %llu\n", o_blocks_count, 1737 o_blocks_count + add); 1738 /* We add the blocks to the bitmap and set the group need init bit */ 1739 err = ext4_group_add_blocks(handle, sb, o_blocks_count, add); 1740 if (err) 1741 goto errout; 1742 ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh); 1743 ext4_debug("freed blocks %llu through %llu\n", o_blocks_count, 1744 o_blocks_count + add); 1745 errout: 1746 err2 = ext4_journal_stop(handle); 1747 if (err2 && !err) 1748 err = err2; 1749 1750 if (!err) { 1751 if (test_opt(sb, DEBUG)) 1752 printk(KERN_DEBUG "EXT4-fs: extended group to %llu " 1753 "blocks\n", ext4_blocks_count(es)); 1754 update_backups(sb, EXT4_SB(sb)->s_sbh->b_blocknr, 1755 (char *)es, sizeof(struct ext4_super_block), 0); 1756 } 1757 return err; 1758 } 1759 1760 /* 1761 * Extend the filesystem to the new number of blocks specified. This entry 1762 * point is only used to extend the current filesystem to the end of the last 1763 * existing group. It can be accessed via ioctl, or by "remount,resize=<size>" 1764 * for emergencies (because it has no dependencies on reserved blocks). 1765 * 1766 * If we _really_ wanted, we could use default values to call ext4_group_add() 1767 * allow the "remount" trick to work for arbitrary resizing, assuming enough 1768 * GDT blocks are reserved to grow to the desired size. 1769 */ 1770 int ext4_group_extend(struct super_block *sb, struct ext4_super_block *es, 1771 ext4_fsblk_t n_blocks_count) 1772 { 1773 ext4_fsblk_t o_blocks_count; 1774 ext4_grpblk_t last; 1775 ext4_grpblk_t add; 1776 struct buffer_head *bh; 1777 int err; 1778 ext4_group_t group; 1779 1780 o_blocks_count = ext4_blocks_count(es); 1781 1782 if (test_opt(sb, DEBUG)) 1783 ext4_msg(sb, KERN_DEBUG, 1784 "extending last group from %llu to %llu blocks", 1785 o_blocks_count, n_blocks_count); 1786 1787 if (n_blocks_count == 0 || n_blocks_count == o_blocks_count) 1788 return 0; 1789 1790 if (n_blocks_count > (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) { 1791 ext4_msg(sb, KERN_ERR, 1792 "filesystem too large to resize to %llu blocks safely", 1793 n_blocks_count); 1794 return -EINVAL; 1795 } 1796 1797 if (n_blocks_count < o_blocks_count) { 1798 ext4_warning(sb, "can't shrink FS - resize aborted"); 1799 return -EINVAL; 1800 } 1801 1802 /* Handle the remaining blocks in the last group only. */ 1803 ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last); 1804 1805 if (last == 0) { 1806 ext4_warning(sb, "need to use ext2online to resize further"); 1807 return -EPERM; 1808 } 1809 1810 add = EXT4_BLOCKS_PER_GROUP(sb) - last; 1811 1812 if (o_blocks_count + add < o_blocks_count) { 1813 ext4_warning(sb, "blocks_count overflow"); 1814 return -EINVAL; 1815 } 1816 1817 if (o_blocks_count + add > n_blocks_count) 1818 add = n_blocks_count - o_blocks_count; 1819 1820 if (o_blocks_count + add < n_blocks_count) 1821 ext4_warning(sb, "will only finish group (%llu blocks, %u new)", 1822 o_blocks_count + add, add); 1823 1824 /* See if the device is actually as big as what was requested */ 1825 bh = ext4_sb_bread(sb, o_blocks_count + add - 1, 0); 1826 if (IS_ERR(bh)) { 1827 ext4_warning(sb, "can't read last block, resize aborted"); 1828 return -ENOSPC; 1829 } 1830 brelse(bh); 1831 1832 err = ext4_group_extend_no_check(sb, o_blocks_count, add); 1833 return err; 1834 } /* ext4_group_extend */ 1835 1836 1837 static int num_desc_blocks(struct super_block *sb, ext4_group_t groups) 1838 { 1839 return (groups + EXT4_DESC_PER_BLOCK(sb) - 1) / EXT4_DESC_PER_BLOCK(sb); 1840 } 1841 1842 /* 1843 * Release the resize inode and drop the resize_inode feature if there 1844 * are no more reserved gdt blocks, and then convert the file system 1845 * to enable meta_bg 1846 */ 1847 static int ext4_convert_meta_bg(struct super_block *sb, struct inode *inode) 1848 { 1849 handle_t *handle; 1850 struct ext4_sb_info *sbi = EXT4_SB(sb); 1851 struct ext4_super_block *es = sbi->s_es; 1852 struct ext4_inode_info *ei = EXT4_I(inode); 1853 ext4_fsblk_t nr; 1854 int i, ret, err = 0; 1855 int credits = 1; 1856 1857 ext4_msg(sb, KERN_INFO, "Converting file system to meta_bg"); 1858 if (inode) { 1859 if (es->s_reserved_gdt_blocks) { 1860 ext4_error(sb, "Unexpected non-zero " 1861 "s_reserved_gdt_blocks"); 1862 return -EPERM; 1863 } 1864 1865 /* Do a quick sanity check of the resize inode */ 1866 if (inode->i_blocks != 1 << (inode->i_blkbits - 1867 (9 - sbi->s_cluster_bits))) 1868 goto invalid_resize_inode; 1869 for (i = 0; i < EXT4_N_BLOCKS; i++) { 1870 if (i == EXT4_DIND_BLOCK) { 1871 if (ei->i_data[i]) 1872 continue; 1873 else 1874 goto invalid_resize_inode; 1875 } 1876 if (ei->i_data[i]) 1877 goto invalid_resize_inode; 1878 } 1879 credits += 3; /* block bitmap, bg descriptor, resize inode */ 1880 } 1881 1882 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, credits); 1883 if (IS_ERR(handle)) 1884 return PTR_ERR(handle); 1885 1886 BUFFER_TRACE(sbi->s_sbh, "get_write_access"); 1887 err = ext4_journal_get_write_access(handle, sbi->s_sbh); 1888 if (err) 1889 goto errout; 1890 1891 lock_buffer(sbi->s_sbh); 1892 ext4_clear_feature_resize_inode(sb); 1893 ext4_set_feature_meta_bg(sb); 1894 sbi->s_es->s_first_meta_bg = 1895 cpu_to_le32(num_desc_blocks(sb, sbi->s_groups_count)); 1896 ext4_superblock_csum_set(sb); 1897 unlock_buffer(sbi->s_sbh); 1898 1899 err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh); 1900 if (err) { 1901 ext4_std_error(sb, err); 1902 goto errout; 1903 } 1904 1905 if (inode) { 1906 nr = le32_to_cpu(ei->i_data[EXT4_DIND_BLOCK]); 1907 ext4_free_blocks(handle, inode, NULL, nr, 1, 1908 EXT4_FREE_BLOCKS_METADATA | 1909 EXT4_FREE_BLOCKS_FORGET); 1910 ei->i_data[EXT4_DIND_BLOCK] = 0; 1911 inode->i_blocks = 0; 1912 1913 err = ext4_mark_inode_dirty(handle, inode); 1914 if (err) 1915 ext4_std_error(sb, err); 1916 } 1917 1918 errout: 1919 ret = ext4_journal_stop(handle); 1920 if (!err) 1921 err = ret; 1922 return ret; 1923 1924 invalid_resize_inode: 1925 ext4_error(sb, "corrupted/inconsistent resize inode"); 1926 return -EINVAL; 1927 } 1928 1929 /* 1930 * ext4_resize_fs() resizes a fs to new size specified by @n_blocks_count 1931 * 1932 * @sb: super block of the fs to be resized 1933 * @n_blocks_count: the number of blocks resides in the resized fs 1934 */ 1935 int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count) 1936 { 1937 struct ext4_new_flex_group_data *flex_gd = NULL; 1938 struct ext4_sb_info *sbi = EXT4_SB(sb); 1939 struct ext4_super_block *es = sbi->s_es; 1940 struct buffer_head *bh; 1941 struct inode *resize_inode = NULL; 1942 ext4_grpblk_t add, offset; 1943 unsigned long n_desc_blocks; 1944 unsigned long o_desc_blocks; 1945 ext4_group_t o_group; 1946 ext4_group_t n_group; 1947 ext4_fsblk_t o_blocks_count; 1948 ext4_fsblk_t n_blocks_count_retry = 0; 1949 unsigned long last_update_time = 0; 1950 int err = 0, flexbg_size = 1 << sbi->s_log_groups_per_flex; 1951 int meta_bg; 1952 1953 /* See if the device is actually as big as what was requested */ 1954 bh = ext4_sb_bread(sb, n_blocks_count - 1, 0); 1955 if (IS_ERR(bh)) { 1956 ext4_warning(sb, "can't read last block, resize aborted"); 1957 return -ENOSPC; 1958 } 1959 brelse(bh); 1960 1961 retry: 1962 o_blocks_count = ext4_blocks_count(es); 1963 1964 ext4_msg(sb, KERN_INFO, "resizing filesystem from %llu " 1965 "to %llu blocks", o_blocks_count, n_blocks_count); 1966 1967 if (n_blocks_count < o_blocks_count) { 1968 /* On-line shrinking not supported */ 1969 ext4_warning(sb, "can't shrink FS - resize aborted"); 1970 return -EINVAL; 1971 } 1972 1973 if (n_blocks_count == o_blocks_count) 1974 /* Nothing need to do */ 1975 return 0; 1976 1977 n_group = ext4_get_group_number(sb, n_blocks_count - 1); 1978 if (n_group >= (0xFFFFFFFFUL / EXT4_INODES_PER_GROUP(sb))) { 1979 ext4_warning(sb, "resize would cause inodes_count overflow"); 1980 return -EINVAL; 1981 } 1982 ext4_get_group_no_and_offset(sb, o_blocks_count - 1, &o_group, &offset); 1983 1984 n_desc_blocks = num_desc_blocks(sb, n_group + 1); 1985 o_desc_blocks = num_desc_blocks(sb, sbi->s_groups_count); 1986 1987 meta_bg = ext4_has_feature_meta_bg(sb); 1988 1989 if (ext4_has_feature_resize_inode(sb)) { 1990 if (meta_bg) { 1991 ext4_error(sb, "resize_inode and meta_bg enabled " 1992 "simultaneously"); 1993 return -EINVAL; 1994 } 1995 if (n_desc_blocks > o_desc_blocks + 1996 le16_to_cpu(es->s_reserved_gdt_blocks)) { 1997 n_blocks_count_retry = n_blocks_count; 1998 n_desc_blocks = o_desc_blocks + 1999 le16_to_cpu(es->s_reserved_gdt_blocks); 2000 n_group = n_desc_blocks * EXT4_DESC_PER_BLOCK(sb); 2001 n_blocks_count = (ext4_fsblk_t)n_group * 2002 EXT4_BLOCKS_PER_GROUP(sb) + 2003 le32_to_cpu(es->s_first_data_block); 2004 n_group--; /* set to last group number */ 2005 } 2006 2007 if (!resize_inode) 2008 resize_inode = ext4_iget(sb, EXT4_RESIZE_INO, 2009 EXT4_IGET_SPECIAL); 2010 if (IS_ERR(resize_inode)) { 2011 ext4_warning(sb, "Error opening resize inode"); 2012 return PTR_ERR(resize_inode); 2013 } 2014 } 2015 2016 if ((!resize_inode && !meta_bg) || n_blocks_count == o_blocks_count) { 2017 err = ext4_convert_meta_bg(sb, resize_inode); 2018 if (err) 2019 goto out; 2020 if (resize_inode) { 2021 iput(resize_inode); 2022 resize_inode = NULL; 2023 } 2024 if (n_blocks_count_retry) { 2025 n_blocks_count = n_blocks_count_retry; 2026 n_blocks_count_retry = 0; 2027 goto retry; 2028 } 2029 } 2030 2031 /* 2032 * Make sure the last group has enough space so that it's 2033 * guaranteed to have enough space for all metadata blocks 2034 * that it might need to hold. (We might not need to store 2035 * the inode table blocks in the last block group, but there 2036 * will be cases where this might be needed.) 2037 */ 2038 if ((ext4_group_first_block_no(sb, n_group) + 2039 ext4_group_overhead_blocks(sb, n_group) + 2 + 2040 sbi->s_itb_per_group + sbi->s_cluster_ratio) >= n_blocks_count) { 2041 n_blocks_count = ext4_group_first_block_no(sb, n_group); 2042 n_group--; 2043 n_blocks_count_retry = 0; 2044 if (resize_inode) { 2045 iput(resize_inode); 2046 resize_inode = NULL; 2047 } 2048 goto retry; 2049 } 2050 2051 /* extend the last group */ 2052 if (n_group == o_group) 2053 add = n_blocks_count - o_blocks_count; 2054 else 2055 add = EXT4_C2B(sbi, EXT4_CLUSTERS_PER_GROUP(sb) - (offset + 1)); 2056 if (add > 0) { 2057 err = ext4_group_extend_no_check(sb, o_blocks_count, add); 2058 if (err) 2059 goto out; 2060 } 2061 2062 if (ext4_blocks_count(es) == n_blocks_count) 2063 goto out; 2064 2065 err = ext4_alloc_flex_bg_array(sb, n_group + 1); 2066 if (err) 2067 goto out; 2068 2069 err = ext4_mb_alloc_groupinfo(sb, n_group + 1); 2070 if (err) 2071 goto out; 2072 2073 flex_gd = alloc_flex_gd(flexbg_size); 2074 if (flex_gd == NULL) { 2075 err = -ENOMEM; 2076 goto out; 2077 } 2078 2079 /* Add flex groups. Note that a regular group is a 2080 * flex group with 1 group. 2081 */ 2082 while (ext4_setup_next_flex_gd(sb, flex_gd, n_blocks_count, 2083 flexbg_size)) { 2084 if (jiffies - last_update_time > HZ * 10) { 2085 if (last_update_time) 2086 ext4_msg(sb, KERN_INFO, 2087 "resized to %llu blocks", 2088 ext4_blocks_count(es)); 2089 last_update_time = jiffies; 2090 } 2091 if (ext4_alloc_group_tables(sb, flex_gd, flexbg_size) != 0) 2092 break; 2093 err = ext4_flex_group_add(sb, resize_inode, flex_gd); 2094 if (unlikely(err)) 2095 break; 2096 } 2097 2098 if (!err && n_blocks_count_retry) { 2099 n_blocks_count = n_blocks_count_retry; 2100 n_blocks_count_retry = 0; 2101 free_flex_gd(flex_gd); 2102 flex_gd = NULL; 2103 if (resize_inode) { 2104 iput(resize_inode); 2105 resize_inode = NULL; 2106 } 2107 goto retry; 2108 } 2109 2110 out: 2111 if (flex_gd) 2112 free_flex_gd(flex_gd); 2113 if (resize_inode != NULL) 2114 iput(resize_inode); 2115 if (err) 2116 ext4_warning(sb, "error (%d) occurred during " 2117 "file system resize", err); 2118 ext4_msg(sb, KERN_INFO, "resized filesystem to %llu", 2119 ext4_blocks_count(es)); 2120 return err; 2121 } 2122