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#include <linux/errno.h> 14#include <linux/slab.h> 15#include <linux/jiffies.h> 16 17#include "ext4_jbd2.h" 18 19struct ext4_rcu_ptr { 20 struct rcu_head rcu; 21 void *ptr; 22}; 23 24static void ext4_rcu_ptr_callback(struct rcu_head *head) 25{ 26 struct ext4_rcu_ptr *ptr; 27 28 ptr = container_of(head, struct ext4_rcu_ptr, rcu); 29 kvfree(ptr->ptr); 30 kfree(ptr); 31} 32 33void ext4_kvfree_array_rcu(void *to_free) 34{ 35 struct ext4_rcu_ptr *ptr = kzalloc(sizeof(*ptr), GFP_KERNEL); 36 37 if (ptr) { 38 ptr->ptr = to_free; 39 call_rcu(&ptr->rcu, ext4_rcu_ptr_callback); 40 return; 41 } 42 synchronize_rcu(); 43 kvfree(to_free); 44} 45 46int ext4_resize_begin(struct super_block *sb) 47{ 48 struct ext4_sb_info *sbi = EXT4_SB(sb); 49 int ret = 0; 50 51 if (!capable(CAP_SYS_RESOURCE)) 52 return -EPERM; 53 54 /* 55 * If the reserved GDT blocks is non-zero, the resize_inode feature 56 * should always be set. 57 */ 58 if (sbi->s_es->s_reserved_gdt_blocks && 59 !ext4_has_feature_resize_inode(sb)) { 60 ext4_error(sb, "resize_inode disabled but reserved GDT blocks non-zero"); 61 return -EFSCORRUPTED; 62 } 63 64 /* 65 * If we are not using the primary superblock/GDT copy don't resize, 66 * because the user tools have no way of handling this. Probably a 67 * bad time to do it anyways. 68 */ 69 if (EXT4_B2C(sbi, sbi->s_sbh->b_blocknr) != 70 le32_to_cpu(sbi->s_es->s_first_data_block)) { 71 ext4_warning(sb, "won't resize using backup superblock at %llu", 72 (unsigned long long)sbi->s_sbh->b_blocknr); 73 return -EPERM; 74 } 75 76 /* 77 * We are not allowed to do online-resizing on a filesystem mounted 78 * with error, because it can destroy the filesystem easily. 79 */ 80 if (sbi->s_mount_state & EXT4_ERROR_FS) { 81 ext4_warning(sb, "There are errors in the filesystem, " 82 "so online resizing is not allowed"); 83 return -EPERM; 84 } 85 86 if (ext4_has_feature_sparse_super2(sb)) { 87 ext4_msg(sb, KERN_ERR, "Online resizing not supported with sparse_super2"); 88 return -EOPNOTSUPP; 89 } 90 91 if (test_and_set_bit_lock(EXT4_FLAGS_RESIZING, 92 &sbi->s_ext4_flags)) 93 ret = -EBUSY; 94 95 return ret; 96} 97 98int ext4_resize_end(struct super_block *sb, bool update_backups) 99{ 100 clear_bit_unlock(EXT4_FLAGS_RESIZING, &EXT4_SB(sb)->s_ext4_flags); 101 smp_mb__after_atomic(); 102 if (update_backups) 103 return ext4_update_overhead(sb, true); 104 return 0; 105} 106 107static 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 120static 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 free_blocks_count = input->blocks_count - 2 - overhead - 144 sbi->s_itb_per_group; 145 input->free_clusters_count = EXT4_B2C(sbi, free_blocks_count); 146 147 if (test_opt(sb, DEBUG)) 148 printk(KERN_DEBUG "EXT4-fs: adding %s group %u: %u blocks " 149 "(%d free, %u reserved)\n", 150 ext4_bg_has_super(sb, input->group) ? "normal" : 151 "no-super", input->group, input->blocks_count, 152 free_blocks_count, input->reserved_blocks); 153 154 ext4_get_group_no_and_offset(sb, start, NULL, &offset); 155 if (offset != 0) 156 ext4_warning(sb, "Last group not full"); 157 else if (input->reserved_blocks > input->blocks_count / 5) 158 ext4_warning(sb, "Reserved blocks too high (%u)", 159 input->reserved_blocks); 160 else if (free_blocks_count < 0) 161 ext4_warning(sb, "Bad blocks count %u", 162 input->blocks_count); 163 else if (IS_ERR(bh = ext4_sb_bread(sb, end - 1, 0))) { 164 err = PTR_ERR(bh); 165 bh = NULL; 166 ext4_warning(sb, "Cannot read last block (%llu)", 167 end - 1); 168 } else if (outside(input->block_bitmap, start, end)) 169 ext4_warning(sb, "Block bitmap not in group (block %llu)", 170 (unsigned long long)input->block_bitmap); 171 else if (outside(input->inode_bitmap, start, end)) 172 ext4_warning(sb, "Inode bitmap not in group (block %llu)", 173 (unsigned long long)input->inode_bitmap); 174 else if (outside(input->inode_table, start, end) || 175 outside(itend - 1, start, end)) 176 ext4_warning(sb, "Inode table not in group (blocks %llu-%llu)", 177 (unsigned long long)input->inode_table, itend - 1); 178 else if (input->inode_bitmap == input->block_bitmap) 179 ext4_warning(sb, "Block bitmap same as inode bitmap (%llu)", 180 (unsigned long long)input->block_bitmap); 181 else if (inside(input->block_bitmap, input->inode_table, itend)) 182 ext4_warning(sb, "Block bitmap (%llu) in inode table " 183 "(%llu-%llu)", 184 (unsigned long long)input->block_bitmap, 185 (unsigned long long)input->inode_table, itend - 1); 186 else if (inside(input->inode_bitmap, input->inode_table, itend)) 187 ext4_warning(sb, "Inode bitmap (%llu) in inode table " 188 "(%llu-%llu)", 189 (unsigned long long)input->inode_bitmap, 190 (unsigned long long)input->inode_table, itend - 1); 191 else if (inside(input->block_bitmap, start, metaend)) 192 ext4_warning(sb, "Block bitmap (%llu) in GDT table (%llu-%llu)", 193 (unsigned long long)input->block_bitmap, 194 start, metaend - 1); 195 else if (inside(input->inode_bitmap, start, metaend)) 196 ext4_warning(sb, "Inode bitmap (%llu) in GDT table (%llu-%llu)", 197 (unsigned long long)input->inode_bitmap, 198 start, metaend - 1); 199 else if (inside(input->inode_table, start, metaend) || 200 inside(itend - 1, start, metaend)) 201 ext4_warning(sb, "Inode table (%llu-%llu) overlaps GDT table " 202 "(%llu-%llu)", 203 (unsigned long long)input->inode_table, 204 itend - 1, start, metaend - 1); 205 else 206 err = 0; 207 brelse(bh); 208 209 return err; 210} 211 212/* 213 * ext4_new_flex_group_data is used by 64bit-resize interface to add a flex 214 * group each time. 215 */ 216struct ext4_new_flex_group_data { 217 struct ext4_new_group_data *groups; /* new_group_data for groups 218 in the flex group */ 219 __u16 *bg_flags; /* block group flags of groups 220 in @groups */ 221 ext4_group_t resize_bg; /* number of allocated 222 new_group_data */ 223 ext4_group_t count; /* number of groups in @groups 224 */ 225}; 226 227/* 228 * Avoiding memory allocation failures due to too many groups added each time. 229 */ 230#define MAX_RESIZE_BG 16384 231 232/* 233 * alloc_flex_gd() allocates a ext4_new_flex_group_data with size of 234 * @flexbg_size. 235 * 236 * Returns NULL on failure otherwise address of the allocated structure. 237 */ 238static struct ext4_new_flex_group_data *alloc_flex_gd(unsigned int flexbg_size, 239 ext4_group_t o_group, ext4_group_t n_group) 240{ 241 ext4_group_t last_group; 242 struct ext4_new_flex_group_data *flex_gd; 243 244 flex_gd = kmalloc(sizeof(*flex_gd), GFP_NOFS); 245 if (flex_gd == NULL) 246 goto out3; 247 248 if (unlikely(flexbg_size > MAX_RESIZE_BG)) 249 flex_gd->resize_bg = MAX_RESIZE_BG; 250 else 251 flex_gd->resize_bg = flexbg_size; 252 253 /* Avoid allocating large 'groups' array if not needed */ 254 last_group = o_group | (flex_gd->resize_bg - 1); 255 if (n_group <= last_group) 256 flex_gd->resize_bg = 1 << fls(n_group - o_group + 1); 257 else if (n_group - last_group < flex_gd->resize_bg) 258 flex_gd->resize_bg = 1 << max(fls(last_group - o_group + 1), 259 fls(n_group - last_group)); 260 261 flex_gd->groups = kmalloc_array(flex_gd->resize_bg, 262 sizeof(struct ext4_new_group_data), 263 GFP_NOFS); 264 if (flex_gd->groups == NULL) 265 goto out2; 266 267 flex_gd->bg_flags = kmalloc_array(flex_gd->resize_bg, sizeof(__u16), 268 GFP_NOFS); 269 if (flex_gd->bg_flags == NULL) 270 goto out1; 271 272 return flex_gd; 273 274out1: 275 kfree(flex_gd->groups); 276out2: 277 kfree(flex_gd); 278out3: 279 return NULL; 280} 281 282static void free_flex_gd(struct ext4_new_flex_group_data *flex_gd) 283{ 284 kfree(flex_gd->bg_flags); 285 kfree(flex_gd->groups); 286 kfree(flex_gd); 287} 288 289/* 290 * ext4_alloc_group_tables() allocates block bitmaps, inode bitmaps 291 * and inode tables for a flex group. 292 * 293 * This function is used by 64bit-resize. Note that this function allocates 294 * group tables from the 1st group of groups contained by @flexgd, which may 295 * be a partial of a flex group. 296 * 297 * @sb: super block of fs to which the groups belongs 298 * 299 * Returns 0 on a successful allocation of the metadata blocks in the 300 * block group. 301 */ 302static int ext4_alloc_group_tables(struct super_block *sb, 303 struct ext4_new_flex_group_data *flex_gd, 304 unsigned int flexbg_size) 305{ 306 struct ext4_new_group_data *group_data = flex_gd->groups; 307 ext4_fsblk_t start_blk; 308 ext4_fsblk_t last_blk; 309 ext4_group_t src_group; 310 ext4_group_t bb_index = 0; 311 ext4_group_t ib_index = 0; 312 ext4_group_t it_index = 0; 313 ext4_group_t group; 314 ext4_group_t last_group; 315 unsigned overhead; 316 __u16 uninit_mask = (flexbg_size > 1) ? ~EXT4_BG_BLOCK_UNINIT : ~0; 317 int i; 318 319 BUG_ON(flex_gd->count == 0 || group_data == NULL); 320 321 src_group = group_data[0].group; 322 last_group = src_group + flex_gd->count - 1; 323 324 BUG_ON((flexbg_size > 1) && ((src_group & ~(flexbg_size - 1)) != 325 (last_group & ~(flexbg_size - 1)))); 326next_group: 327 group = group_data[0].group; 328 if (src_group >= group_data[0].group + flex_gd->count) 329 return -ENOSPC; 330 start_blk = ext4_group_first_block_no(sb, src_group); 331 last_blk = start_blk + group_data[src_group - group].blocks_count; 332 333 overhead = ext4_group_overhead_blocks(sb, src_group); 334 335 start_blk += overhead; 336 337 /* We collect contiguous blocks as much as possible. */ 338 src_group++; 339 for (; src_group <= last_group; src_group++) { 340 overhead = ext4_group_overhead_blocks(sb, src_group); 341 if (overhead == 0) 342 last_blk += group_data[src_group - group].blocks_count; 343 else 344 break; 345 } 346 347 /* Allocate block bitmaps */ 348 for (; bb_index < flex_gd->count; bb_index++) { 349 if (start_blk >= last_blk) 350 goto next_group; 351 group_data[bb_index].block_bitmap = start_blk++; 352 group = ext4_get_group_number(sb, start_blk - 1); 353 group -= group_data[0].group; 354 group_data[group].mdata_blocks++; 355 flex_gd->bg_flags[group] &= uninit_mask; 356 } 357 358 /* Allocate inode bitmaps */ 359 for (; ib_index < flex_gd->count; ib_index++) { 360 if (start_blk >= last_blk) 361 goto next_group; 362 group_data[ib_index].inode_bitmap = start_blk++; 363 group = ext4_get_group_number(sb, start_blk - 1); 364 group -= group_data[0].group; 365 group_data[group].mdata_blocks++; 366 flex_gd->bg_flags[group] &= uninit_mask; 367 } 368 369 /* Allocate inode tables */ 370 for (; it_index < flex_gd->count; it_index++) { 371 unsigned int itb = EXT4_SB(sb)->s_itb_per_group; 372 ext4_fsblk_t next_group_start; 373 374 if (start_blk + itb > last_blk) 375 goto next_group; 376 group_data[it_index].inode_table = start_blk; 377 group = ext4_get_group_number(sb, start_blk); 378 next_group_start = ext4_group_first_block_no(sb, group + 1); 379 group -= group_data[0].group; 380 381 if (start_blk + itb > next_group_start) { 382 flex_gd->bg_flags[group + 1] &= uninit_mask; 383 overhead = start_blk + itb - next_group_start; 384 group_data[group + 1].mdata_blocks += overhead; 385 itb -= overhead; 386 } 387 388 group_data[group].mdata_blocks += itb; 389 flex_gd->bg_flags[group] &= uninit_mask; 390 start_blk += EXT4_SB(sb)->s_itb_per_group; 391 } 392 393 /* Update free clusters count to exclude metadata blocks */ 394 for (i = 0; i < flex_gd->count; i++) { 395 group_data[i].free_clusters_count -= 396 EXT4_NUM_B2C(EXT4_SB(sb), 397 group_data[i].mdata_blocks); 398 } 399 400 if (test_opt(sb, DEBUG)) { 401 int i; 402 group = group_data[0].group; 403 404 printk(KERN_DEBUG "EXT4-fs: adding a flex group with " 405 "%u groups, flexbg size is %u:\n", flex_gd->count, 406 flexbg_size); 407 408 for (i = 0; i < flex_gd->count; i++) { 409 ext4_debug( 410 "adding %s group %u: %u blocks (%u free, %u mdata blocks)\n", 411 ext4_bg_has_super(sb, group + i) ? "normal" : 412 "no-super", group + i, 413 group_data[i].blocks_count, 414 group_data[i].free_clusters_count, 415 group_data[i].mdata_blocks); 416 } 417 } 418 return 0; 419} 420 421static struct buffer_head *bclean(handle_t *handle, struct super_block *sb, 422 ext4_fsblk_t blk) 423{ 424 struct buffer_head *bh; 425 int err; 426 427 bh = sb_getblk(sb, blk); 428 if (unlikely(!bh)) 429 return ERR_PTR(-ENOMEM); 430 BUFFER_TRACE(bh, "get_write_access"); 431 err = ext4_journal_get_write_access(handle, sb, bh, EXT4_JTR_NONE); 432 if (err) { 433 brelse(bh); 434 bh = ERR_PTR(err); 435 } else { 436 memset(bh->b_data, 0, sb->s_blocksize); 437 set_buffer_uptodate(bh); 438 } 439 440 return bh; 441} 442 443static int ext4_resize_ensure_credits_batch(handle_t *handle, int credits) 444{ 445 return ext4_journal_ensure_credits_fn(handle, credits, 446 EXT4_MAX_TRANS_DATA, 0, 0); 447} 448 449/* 450 * set_flexbg_block_bitmap() mark clusters [@first_cluster, @last_cluster] used. 451 * 452 * Helper function for ext4_setup_new_group_blocks() which set . 453 * 454 * @sb: super block 455 * @handle: journal handle 456 * @flex_gd: flex group data 457 */ 458static int set_flexbg_block_bitmap(struct super_block *sb, handle_t *handle, 459 struct ext4_new_flex_group_data *flex_gd, 460 ext4_fsblk_t first_cluster, ext4_fsblk_t last_cluster) 461{ 462 struct ext4_sb_info *sbi = EXT4_SB(sb); 463 ext4_group_t count = last_cluster - first_cluster + 1; 464 ext4_group_t count2; 465 466 ext4_debug("mark clusters [%llu-%llu] used\n", first_cluster, 467 last_cluster); 468 for (; count > 0; count -= count2, first_cluster += count2) { 469 ext4_fsblk_t start; 470 struct buffer_head *bh; 471 ext4_group_t group; 472 int err; 473 474 group = ext4_get_group_number(sb, EXT4_C2B(sbi, first_cluster)); 475 start = EXT4_B2C(sbi, ext4_group_first_block_no(sb, group)); 476 group -= flex_gd->groups[0].group; 477 478 count2 = EXT4_CLUSTERS_PER_GROUP(sb) - (first_cluster - start); 479 if (count2 > count) 480 count2 = count; 481 482 if (flex_gd->bg_flags[group] & EXT4_BG_BLOCK_UNINIT) { 483 BUG_ON(flex_gd->count > 1); 484 continue; 485 } 486 487 err = ext4_resize_ensure_credits_batch(handle, 1); 488 if (err < 0) 489 return err; 490 491 bh = sb_getblk(sb, flex_gd->groups[group].block_bitmap); 492 if (unlikely(!bh)) 493 return -ENOMEM; 494 495 BUFFER_TRACE(bh, "get_write_access"); 496 err = ext4_journal_get_write_access(handle, sb, bh, 497 EXT4_JTR_NONE); 498 if (err) { 499 brelse(bh); 500 return err; 501 } 502 ext4_debug("mark block bitmap %#04llx (+%llu/%u)\n", 503 first_cluster, first_cluster - start, count2); 504 mb_set_bits(bh->b_data, first_cluster - start, count2); 505 506 err = ext4_handle_dirty_metadata(handle, NULL, bh); 507 brelse(bh); 508 if (unlikely(err)) 509 return err; 510 } 511 512 return 0; 513} 514 515/* 516 * Set up the block and inode bitmaps, and the inode table for the new groups. 517 * This doesn't need to be part of the main transaction, since we are only 518 * changing blocks outside the actual filesystem. We still do journaling to 519 * ensure the recovery is correct in case of a failure just after resize. 520 * If any part of this fails, we simply abort the resize. 521 * 522 * setup_new_flex_group_blocks handles a flex group as follow: 523 * 1. copy super block and GDT, and initialize group tables if necessary. 524 * In this step, we only set bits in blocks bitmaps for blocks taken by 525 * super block and GDT. 526 * 2. allocate group tables in block bitmaps, that is, set bits in block 527 * bitmap for blocks taken by group tables. 528 */ 529static int setup_new_flex_group_blocks(struct super_block *sb, 530 struct ext4_new_flex_group_data *flex_gd) 531{ 532 int group_table_count[] = {1, 1, EXT4_SB(sb)->s_itb_per_group}; 533 ext4_fsblk_t start; 534 ext4_fsblk_t block; 535 struct ext4_sb_info *sbi = EXT4_SB(sb); 536 struct ext4_super_block *es = sbi->s_es; 537 struct ext4_new_group_data *group_data = flex_gd->groups; 538 __u16 *bg_flags = flex_gd->bg_flags; 539 handle_t *handle; 540 ext4_group_t group, count; 541 struct buffer_head *bh = NULL; 542 int reserved_gdb, i, j, err = 0, err2; 543 int meta_bg; 544 545 BUG_ON(!flex_gd->count || !group_data || 546 group_data[0].group != sbi->s_groups_count); 547 548 reserved_gdb = le16_to_cpu(es->s_reserved_gdt_blocks); 549 meta_bg = ext4_has_feature_meta_bg(sb); 550 551 /* This transaction may be extended/restarted along the way */ 552 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, EXT4_MAX_TRANS_DATA); 553 if (IS_ERR(handle)) 554 return PTR_ERR(handle); 555 556 group = group_data[0].group; 557 for (i = 0; i < flex_gd->count; i++, group++) { 558 unsigned long gdblocks; 559 ext4_grpblk_t overhead; 560 561 gdblocks = ext4_bg_num_gdb(sb, group); 562 start = ext4_group_first_block_no(sb, group); 563 564 if (meta_bg == 0 && !ext4_bg_has_super(sb, group)) 565 goto handle_itb; 566 567 if (meta_bg == 1) 568 goto handle_itb; 569 570 block = start + ext4_bg_has_super(sb, group); 571 /* Copy all of the GDT blocks into the backup in this group */ 572 for (j = 0; j < gdblocks; j++, block++) { 573 struct buffer_head *gdb; 574 575 ext4_debug("update backup group %#04llx\n", block); 576 err = ext4_resize_ensure_credits_batch(handle, 1); 577 if (err < 0) 578 goto out; 579 580 gdb = sb_getblk(sb, block); 581 if (unlikely(!gdb)) { 582 err = -ENOMEM; 583 goto out; 584 } 585 586 BUFFER_TRACE(gdb, "get_write_access"); 587 err = ext4_journal_get_write_access(handle, sb, gdb, 588 EXT4_JTR_NONE); 589 if (err) { 590 brelse(gdb); 591 goto out; 592 } 593 memcpy(gdb->b_data, sbi_array_rcu_deref(sbi, 594 s_group_desc, j)->b_data, gdb->b_size); 595 set_buffer_uptodate(gdb); 596 597 err = ext4_handle_dirty_metadata(handle, NULL, gdb); 598 if (unlikely(err)) { 599 brelse(gdb); 600 goto out; 601 } 602 brelse(gdb); 603 } 604 605 /* Zero out all of the reserved backup group descriptor 606 * table blocks 607 */ 608 if (ext4_bg_has_super(sb, group)) { 609 err = sb_issue_zeroout(sb, gdblocks + start + 1, 610 reserved_gdb, GFP_NOFS); 611 if (err) 612 goto out; 613 } 614 615handle_itb: 616 /* Initialize group tables of the group @group */ 617 if (!(bg_flags[i] & EXT4_BG_INODE_ZEROED)) 618 goto handle_bb; 619 620 /* Zero out all of the inode table blocks */ 621 block = group_data[i].inode_table; 622 ext4_debug("clear inode table blocks %#04llx -> %#04lx\n", 623 block, sbi->s_itb_per_group); 624 err = sb_issue_zeroout(sb, block, sbi->s_itb_per_group, 625 GFP_NOFS); 626 if (err) 627 goto out; 628 629handle_bb: 630 if (bg_flags[i] & EXT4_BG_BLOCK_UNINIT) 631 goto handle_ib; 632 633 /* Initialize block bitmap of the @group */ 634 block = group_data[i].block_bitmap; 635 err = ext4_resize_ensure_credits_batch(handle, 1); 636 if (err < 0) 637 goto out; 638 639 bh = bclean(handle, sb, block); 640 if (IS_ERR(bh)) { 641 err = PTR_ERR(bh); 642 goto out; 643 } 644 overhead = ext4_group_overhead_blocks(sb, group); 645 if (overhead != 0) { 646 ext4_debug("mark backup superblock %#04llx (+0)\n", 647 start); 648 mb_set_bits(bh->b_data, 0, 649 EXT4_NUM_B2C(sbi, overhead)); 650 } 651 ext4_mark_bitmap_end(EXT4_B2C(sbi, group_data[i].blocks_count), 652 sb->s_blocksize * 8, bh->b_data); 653 err = ext4_handle_dirty_metadata(handle, NULL, bh); 654 brelse(bh); 655 if (err) 656 goto out; 657 658handle_ib: 659 if (bg_flags[i] & EXT4_BG_INODE_UNINIT) 660 continue; 661 662 /* Initialize inode bitmap of the @group */ 663 block = group_data[i].inode_bitmap; 664 err = ext4_resize_ensure_credits_batch(handle, 1); 665 if (err < 0) 666 goto out; 667 /* Mark unused entries in inode bitmap used */ 668 bh = bclean(handle, sb, block); 669 if (IS_ERR(bh)) { 670 err = PTR_ERR(bh); 671 goto out; 672 } 673 674 ext4_mark_bitmap_end(EXT4_INODES_PER_GROUP(sb), 675 sb->s_blocksize * 8, bh->b_data); 676 err = ext4_handle_dirty_metadata(handle, NULL, bh); 677 brelse(bh); 678 if (err) 679 goto out; 680 } 681 682 /* Mark group tables in block bitmap */ 683 for (j = 0; j < GROUP_TABLE_COUNT; j++) { 684 count = group_table_count[j]; 685 start = (&group_data[0].block_bitmap)[j]; 686 block = start; 687 for (i = 1; i < flex_gd->count; i++) { 688 block += group_table_count[j]; 689 if (block == (&group_data[i].block_bitmap)[j]) { 690 count += group_table_count[j]; 691 continue; 692 } 693 err = set_flexbg_block_bitmap(sb, handle, 694 flex_gd, 695 EXT4_B2C(sbi, start), 696 EXT4_B2C(sbi, 697 start + count 698 - 1)); 699 if (err) 700 goto out; 701 count = group_table_count[j]; 702 start = (&group_data[i].block_bitmap)[j]; 703 block = start; 704 } 705 706 err = set_flexbg_block_bitmap(sb, handle, 707 flex_gd, 708 EXT4_B2C(sbi, start), 709 EXT4_B2C(sbi, 710 start + count 711 - 1)); 712 if (err) 713 goto out; 714 } 715 716out: 717 err2 = ext4_journal_stop(handle); 718 if (err2 && !err) 719 err = err2; 720 721 return err; 722} 723 724/* 725 * Iterate through the groups which hold BACKUP superblock/GDT copies in an 726 * ext4 filesystem. The counters should be initialized to 1, 5, and 7 before 727 * calling this for the first time. In a sparse filesystem it will be the 728 * sequence of powers of 3, 5, and 7: 1, 3, 5, 7, 9, 25, 27, 49, 81, ... 729 * For a non-sparse filesystem it will be every group: 1, 2, 3, 4, ... 730 */ 731unsigned int ext4_list_backups(struct super_block *sb, unsigned int *three, 732 unsigned int *five, unsigned int *seven) 733{ 734 struct ext4_super_block *es = EXT4_SB(sb)->s_es; 735 unsigned int *min = three; 736 int mult = 3; 737 unsigned int ret; 738 739 if (ext4_has_feature_sparse_super2(sb)) { 740 do { 741 if (*min > 2) 742 return UINT_MAX; 743 ret = le32_to_cpu(es->s_backup_bgs[*min - 1]); 744 *min += 1; 745 } while (!ret); 746 return ret; 747 } 748 749 if (!ext4_has_feature_sparse_super(sb)) { 750 ret = *min; 751 *min += 1; 752 return ret; 753 } 754 755 if (*five < *min) { 756 min = five; 757 mult = 5; 758 } 759 if (*seven < *min) { 760 min = seven; 761 mult = 7; 762 } 763 764 ret = *min; 765 *min *= mult; 766 767 return ret; 768} 769 770/* 771 * Check that all of the backup GDT blocks are held in the primary GDT block. 772 * It is assumed that they are stored in group order. Returns the number of 773 * groups in current filesystem that have BACKUPS, or -ve error code. 774 */ 775static int verify_reserved_gdb(struct super_block *sb, 776 ext4_group_t end, 777 struct buffer_head *primary) 778{ 779 const ext4_fsblk_t blk = primary->b_blocknr; 780 unsigned three = 1; 781 unsigned five = 5; 782 unsigned seven = 7; 783 unsigned grp; 784 __le32 *p = (__le32 *)primary->b_data; 785 int gdbackups = 0; 786 787 while ((grp = ext4_list_backups(sb, &three, &five, &seven)) < end) { 788 if (le32_to_cpu(*p++) != 789 grp * EXT4_BLOCKS_PER_GROUP(sb) + blk){ 790 ext4_warning(sb, "reserved GDT %llu" 791 " missing grp %d (%llu)", 792 blk, grp, 793 grp * 794 (ext4_fsblk_t)EXT4_BLOCKS_PER_GROUP(sb) + 795 blk); 796 return -EINVAL; 797 } 798 if (++gdbackups > EXT4_ADDR_PER_BLOCK(sb)) 799 return -EFBIG; 800 } 801 802 return gdbackups; 803} 804 805/* 806 * Called when we need to bring a reserved group descriptor table block into 807 * use from the resize inode. The primary copy of the new GDT block currently 808 * is an indirect block (under the double indirect block in the resize inode). 809 * The new backup GDT blocks will be stored as leaf blocks in this indirect 810 * block, in group order. Even though we know all the block numbers we need, 811 * we check to ensure that the resize inode has actually reserved these blocks. 812 * 813 * Don't need to update the block bitmaps because the blocks are still in use. 814 * 815 * We get all of the error cases out of the way, so that we are sure to not 816 * fail once we start modifying the data on disk, because JBD has no rollback. 817 */ 818static int add_new_gdb(handle_t *handle, struct inode *inode, 819 ext4_group_t group) 820{ 821 struct super_block *sb = inode->i_sb; 822 struct ext4_super_block *es = EXT4_SB(sb)->s_es; 823 unsigned long gdb_num = group / EXT4_DESC_PER_BLOCK(sb); 824 ext4_fsblk_t gdblock = EXT4_SB(sb)->s_sbh->b_blocknr + 1 + gdb_num; 825 struct buffer_head **o_group_desc, **n_group_desc = NULL; 826 struct buffer_head *dind = NULL; 827 struct buffer_head *gdb_bh = NULL; 828 int gdbackups; 829 struct ext4_iloc iloc = { .bh = NULL }; 830 __le32 *data; 831 int err; 832 833 if (test_opt(sb, DEBUG)) 834 printk(KERN_DEBUG 835 "EXT4-fs: ext4_add_new_gdb: adding group block %lu\n", 836 gdb_num); 837 838 gdb_bh = ext4_sb_bread(sb, gdblock, 0); 839 if (IS_ERR(gdb_bh)) 840 return PTR_ERR(gdb_bh); 841 842 gdbackups = verify_reserved_gdb(sb, group, gdb_bh); 843 if (gdbackups < 0) { 844 err = gdbackups; 845 goto errout; 846 } 847 848 data = EXT4_I(inode)->i_data + EXT4_DIND_BLOCK; 849 dind = ext4_sb_bread(sb, le32_to_cpu(*data), 0); 850 if (IS_ERR(dind)) { 851 err = PTR_ERR(dind); 852 dind = NULL; 853 goto errout; 854 } 855 856 data = (__le32 *)dind->b_data; 857 if (le32_to_cpu(data[gdb_num % EXT4_ADDR_PER_BLOCK(sb)]) != gdblock) { 858 ext4_warning(sb, "new group %u GDT block %llu not reserved", 859 group, gdblock); 860 err = -EINVAL; 861 goto errout; 862 } 863 864 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access"); 865 err = ext4_journal_get_write_access(handle, sb, EXT4_SB(sb)->s_sbh, 866 EXT4_JTR_NONE); 867 if (unlikely(err)) 868 goto errout; 869 870 BUFFER_TRACE(gdb_bh, "get_write_access"); 871 err = ext4_journal_get_write_access(handle, sb, gdb_bh, EXT4_JTR_NONE); 872 if (unlikely(err)) 873 goto errout; 874 875 BUFFER_TRACE(dind, "get_write_access"); 876 err = ext4_journal_get_write_access(handle, sb, dind, EXT4_JTR_NONE); 877 if (unlikely(err)) { 878 ext4_std_error(sb, err); 879 goto errout; 880 } 881 882 /* ext4_reserve_inode_write() gets a reference on the iloc */ 883 err = ext4_reserve_inode_write(handle, inode, &iloc); 884 if (unlikely(err)) 885 goto errout; 886 887 n_group_desc = kvmalloc((gdb_num + 1) * sizeof(struct buffer_head *), 888 GFP_KERNEL); 889 if (!n_group_desc) { 890 err = -ENOMEM; 891 ext4_warning(sb, "not enough memory for %lu groups", 892 gdb_num + 1); 893 goto errout; 894 } 895 896 /* 897 * Finally, we have all of the possible failures behind us... 898 * 899 * Remove new GDT block from inode double-indirect block and clear out 900 * the new GDT block for use (which also "frees" the backup GDT blocks 901 * from the reserved inode). We don't need to change the bitmaps for 902 * these blocks, because they are marked as in-use from being in the 903 * reserved inode, and will become GDT blocks (primary and backup). 904 */ 905 data[gdb_num % EXT4_ADDR_PER_BLOCK(sb)] = 0; 906 err = ext4_handle_dirty_metadata(handle, NULL, dind); 907 if (unlikely(err)) { 908 ext4_std_error(sb, err); 909 goto errout; 910 } 911 inode->i_blocks -= (gdbackups + 1) * sb->s_blocksize >> 912 (9 - EXT4_SB(sb)->s_cluster_bits); 913 ext4_mark_iloc_dirty(handle, inode, &iloc); 914 memset(gdb_bh->b_data, 0, sb->s_blocksize); 915 err = ext4_handle_dirty_metadata(handle, NULL, gdb_bh); 916 if (unlikely(err)) { 917 ext4_std_error(sb, err); 918 iloc.bh = NULL; 919 goto errout; 920 } 921 brelse(dind); 922 923 rcu_read_lock(); 924 o_group_desc = rcu_dereference(EXT4_SB(sb)->s_group_desc); 925 memcpy(n_group_desc, o_group_desc, 926 EXT4_SB(sb)->s_gdb_count * sizeof(struct buffer_head *)); 927 rcu_read_unlock(); 928 n_group_desc[gdb_num] = gdb_bh; 929 rcu_assign_pointer(EXT4_SB(sb)->s_group_desc, n_group_desc); 930 EXT4_SB(sb)->s_gdb_count++; 931 ext4_kvfree_array_rcu(o_group_desc); 932 933 lock_buffer(EXT4_SB(sb)->s_sbh); 934 le16_add_cpu(&es->s_reserved_gdt_blocks, -1); 935 ext4_superblock_csum_set(sb); 936 unlock_buffer(EXT4_SB(sb)->s_sbh); 937 err = ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh); 938 if (err) 939 ext4_std_error(sb, err); 940 return err; 941errout: 942 kvfree(n_group_desc); 943 brelse(iloc.bh); 944 brelse(dind); 945 brelse(gdb_bh); 946 947 ext4_debug("leaving with error %d\n", err); 948 return err; 949} 950 951/* 952 * If there is no available space in the existing block group descriptors for 953 * the new block group and there are no reserved block group descriptors, then 954 * the meta_bg feature will get enabled, and es->s_first_meta_bg will get set 955 * to the first block group that is managed using meta_bg and s_first_meta_bg 956 * must be a multiple of EXT4_DESC_PER_BLOCK(sb). 957 * This function will be called when first group of meta_bg is added to bring 958 * new group descriptors block of new added meta_bg. 959 */ 960static int add_new_gdb_meta_bg(struct super_block *sb, 961 handle_t *handle, ext4_group_t group) { 962 ext4_fsblk_t gdblock; 963 struct buffer_head *gdb_bh; 964 struct buffer_head **o_group_desc, **n_group_desc; 965 unsigned long gdb_num = group / EXT4_DESC_PER_BLOCK(sb); 966 int err; 967 968 gdblock = ext4_group_first_block_no(sb, group) + 969 ext4_bg_has_super(sb, group); 970 gdb_bh = ext4_sb_bread(sb, gdblock, 0); 971 if (IS_ERR(gdb_bh)) 972 return PTR_ERR(gdb_bh); 973 n_group_desc = kvmalloc((gdb_num + 1) * sizeof(struct buffer_head *), 974 GFP_KERNEL); 975 if (!n_group_desc) { 976 brelse(gdb_bh); 977 err = -ENOMEM; 978 ext4_warning(sb, "not enough memory for %lu groups", 979 gdb_num + 1); 980 return err; 981 } 982 983 rcu_read_lock(); 984 o_group_desc = rcu_dereference(EXT4_SB(sb)->s_group_desc); 985 memcpy(n_group_desc, o_group_desc, 986 EXT4_SB(sb)->s_gdb_count * sizeof(struct buffer_head *)); 987 rcu_read_unlock(); 988 n_group_desc[gdb_num] = gdb_bh; 989 990 BUFFER_TRACE(gdb_bh, "get_write_access"); 991 err = ext4_journal_get_write_access(handle, sb, gdb_bh, EXT4_JTR_NONE); 992 if (err) { 993 kvfree(n_group_desc); 994 brelse(gdb_bh); 995 return err; 996 } 997 998 rcu_assign_pointer(EXT4_SB(sb)->s_group_desc, n_group_desc); 999 EXT4_SB(sb)->s_gdb_count++; 1000 ext4_kvfree_array_rcu(o_group_desc); 1001 return err; 1002} 1003 1004/* 1005 * Called when we are adding a new group which has a backup copy of each of 1006 * the GDT blocks (i.e. sparse group) and there are reserved GDT blocks. 1007 * We need to add these reserved backup GDT blocks to the resize inode, so 1008 * that they are kept for future resizing and not allocated to files. 1009 * 1010 * Each reserved backup GDT block will go into a different indirect block. 1011 * The indirect blocks are actually the primary reserved GDT blocks, 1012 * so we know in advance what their block numbers are. We only get the 1013 * double-indirect block to verify it is pointing to the primary reserved 1014 * GDT blocks so we don't overwrite a data block by accident. The reserved 1015 * backup GDT blocks are stored in their reserved primary GDT block. 1016 */ 1017static int reserve_backup_gdb(handle_t *handle, struct inode *inode, 1018 ext4_group_t group) 1019{ 1020 struct super_block *sb = inode->i_sb; 1021 int reserved_gdb =le16_to_cpu(EXT4_SB(sb)->s_es->s_reserved_gdt_blocks); 1022 int cluster_bits = EXT4_SB(sb)->s_cluster_bits; 1023 struct buffer_head **primary; 1024 struct buffer_head *dind; 1025 struct ext4_iloc iloc; 1026 ext4_fsblk_t blk; 1027 __le32 *data, *end; 1028 int gdbackups = 0; 1029 int res, i; 1030 int err; 1031 1032 primary = kmalloc_array(reserved_gdb, sizeof(*primary), GFP_NOFS); 1033 if (!primary) 1034 return -ENOMEM; 1035 1036 data = EXT4_I(inode)->i_data + EXT4_DIND_BLOCK; 1037 dind = ext4_sb_bread(sb, le32_to_cpu(*data), 0); 1038 if (IS_ERR(dind)) { 1039 err = PTR_ERR(dind); 1040 dind = NULL; 1041 goto exit_free; 1042 } 1043 1044 blk = EXT4_SB(sb)->s_sbh->b_blocknr + 1 + EXT4_SB(sb)->s_gdb_count; 1045 data = (__le32 *)dind->b_data + (EXT4_SB(sb)->s_gdb_count % 1046 EXT4_ADDR_PER_BLOCK(sb)); 1047 end = (__le32 *)dind->b_data + EXT4_ADDR_PER_BLOCK(sb); 1048 1049 /* Get each reserved primary GDT block and verify it holds backups */ 1050 for (res = 0; res < reserved_gdb; res++, blk++) { 1051 if (le32_to_cpu(*data) != blk) { 1052 ext4_warning(sb, "reserved block %llu" 1053 " not at offset %ld", 1054 blk, 1055 (long)(data - (__le32 *)dind->b_data)); 1056 err = -EINVAL; 1057 goto exit_bh; 1058 } 1059 primary[res] = ext4_sb_bread(sb, blk, 0); 1060 if (IS_ERR(primary[res])) { 1061 err = PTR_ERR(primary[res]); 1062 primary[res] = NULL; 1063 goto exit_bh; 1064 } 1065 gdbackups = verify_reserved_gdb(sb, group, primary[res]); 1066 if (gdbackups < 0) { 1067 brelse(primary[res]); 1068 err = gdbackups; 1069 goto exit_bh; 1070 } 1071 if (++data >= end) 1072 data = (__le32 *)dind->b_data; 1073 } 1074 1075 for (i = 0; i < reserved_gdb; i++) { 1076 BUFFER_TRACE(primary[i], "get_write_access"); 1077 if ((err = ext4_journal_get_write_access(handle, sb, primary[i], 1078 EXT4_JTR_NONE))) 1079 goto exit_bh; 1080 } 1081 1082 if ((err = ext4_reserve_inode_write(handle, inode, &iloc))) 1083 goto exit_bh; 1084 1085 /* 1086 * Finally we can add each of the reserved backup GDT blocks from 1087 * the new group to its reserved primary GDT block. 1088 */ 1089 blk = group * EXT4_BLOCKS_PER_GROUP(sb); 1090 for (i = 0; i < reserved_gdb; i++) { 1091 int err2; 1092 data = (__le32 *)primary[i]->b_data; 1093 data[gdbackups] = cpu_to_le32(blk + primary[i]->b_blocknr); 1094 err2 = ext4_handle_dirty_metadata(handle, NULL, primary[i]); 1095 if (!err) 1096 err = err2; 1097 } 1098 1099 inode->i_blocks += reserved_gdb * sb->s_blocksize >> (9 - cluster_bits); 1100 ext4_mark_iloc_dirty(handle, inode, &iloc); 1101 1102exit_bh: 1103 while (--res >= 0) 1104 brelse(primary[res]); 1105 brelse(dind); 1106 1107exit_free: 1108 kfree(primary); 1109 1110 return err; 1111} 1112 1113static inline void ext4_set_block_group_nr(struct super_block *sb, char *data, 1114 ext4_group_t group) 1115{ 1116 struct ext4_super_block *es = (struct ext4_super_block *) data; 1117 1118 es->s_block_group_nr = cpu_to_le16(group); 1119 if (ext4_has_metadata_csum(sb)) 1120 es->s_checksum = ext4_superblock_csum(sb, es); 1121} 1122 1123/* 1124 * Update the backup copies of the ext4 metadata. These don't need to be part 1125 * of the main resize transaction, because e2fsck will re-write them if there 1126 * is a problem (basically only OOM will cause a problem). However, we 1127 * _should_ update the backups if possible, in case the primary gets trashed 1128 * for some reason and we need to run e2fsck from a backup superblock. The 1129 * important part is that the new block and inode counts are in the backup 1130 * superblocks, and the location of the new group metadata in the GDT backups. 1131 * 1132 * We do not need take the s_resize_lock for this, because these 1133 * blocks are not otherwise touched by the filesystem code when it is 1134 * mounted. We don't need to worry about last changing from 1135 * sbi->s_groups_count, because the worst that can happen is that we 1136 * do not copy the full number of backups at this time. The resize 1137 * which changed s_groups_count will backup again. 1138 */ 1139static void update_backups(struct super_block *sb, sector_t blk_off, char *data, 1140 int size, int meta_bg) 1141{ 1142 struct ext4_sb_info *sbi = EXT4_SB(sb); 1143 ext4_group_t last; 1144 const int bpg = EXT4_BLOCKS_PER_GROUP(sb); 1145 unsigned three = 1; 1146 unsigned five = 5; 1147 unsigned seven = 7; 1148 ext4_group_t group = 0; 1149 int rest = sb->s_blocksize - size; 1150 handle_t *handle; 1151 int err = 0, err2; 1152 1153 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, EXT4_MAX_TRANS_DATA); 1154 if (IS_ERR(handle)) { 1155 group = 1; 1156 err = PTR_ERR(handle); 1157 goto exit_err; 1158 } 1159 1160 if (meta_bg == 0) { 1161 group = ext4_list_backups(sb, &three, &five, &seven); 1162 last = sbi->s_groups_count; 1163 } else { 1164 group = ext4_get_group_number(sb, blk_off) + 1; 1165 last = (ext4_group_t)(group + EXT4_DESC_PER_BLOCK(sb) - 2); 1166 } 1167 1168 while (group < sbi->s_groups_count) { 1169 struct buffer_head *bh; 1170 ext4_fsblk_t backup_block; 1171 int has_super = ext4_bg_has_super(sb, group); 1172 ext4_fsblk_t first_block = ext4_group_first_block_no(sb, group); 1173 1174 /* Out of journal space, and can't get more - abort - so sad */ 1175 err = ext4_resize_ensure_credits_batch(handle, 1); 1176 if (err < 0) 1177 break; 1178 1179 if (meta_bg == 0) 1180 backup_block = ((ext4_fsblk_t)group) * bpg + blk_off; 1181 else 1182 backup_block = first_block + has_super; 1183 1184 bh = sb_getblk(sb, backup_block); 1185 if (unlikely(!bh)) { 1186 err = -ENOMEM; 1187 break; 1188 } 1189 ext4_debug("update metadata backup %llu(+%llu)\n", 1190 backup_block, backup_block - 1191 ext4_group_first_block_no(sb, group)); 1192 BUFFER_TRACE(bh, "get_write_access"); 1193 if ((err = ext4_journal_get_write_access(handle, sb, bh, 1194 EXT4_JTR_NONE))) { 1195 brelse(bh); 1196 break; 1197 } 1198 lock_buffer(bh); 1199 memcpy(bh->b_data, data, size); 1200 if (rest) 1201 memset(bh->b_data + size, 0, rest); 1202 if (has_super && (backup_block == first_block)) 1203 ext4_set_block_group_nr(sb, bh->b_data, group); 1204 set_buffer_uptodate(bh); 1205 unlock_buffer(bh); 1206 err = ext4_handle_dirty_metadata(handle, NULL, bh); 1207 if (unlikely(err)) 1208 ext4_std_error(sb, err); 1209 brelse(bh); 1210 1211 if (meta_bg == 0) 1212 group = ext4_list_backups(sb, &three, &five, &seven); 1213 else if (group == last) 1214 break; 1215 else 1216 group = last; 1217 } 1218 if ((err2 = ext4_journal_stop(handle)) && !err) 1219 err = err2; 1220 1221 /* 1222 * Ugh! Need to have e2fsck write the backup copies. It is too 1223 * late to revert the resize, we shouldn't fail just because of 1224 * the backup copies (they are only needed in case of corruption). 1225 * 1226 * However, if we got here we have a journal problem too, so we 1227 * can't really start a transaction to mark the superblock. 1228 * Chicken out and just set the flag on the hope it will be written 1229 * to disk, and if not - we will simply wait until next fsck. 1230 */ 1231exit_err: 1232 if (err) { 1233 ext4_warning(sb, "can't update backup for group %u (err %d), " 1234 "forcing fsck on next reboot", group, err); 1235 sbi->s_mount_state &= ~EXT4_VALID_FS; 1236 sbi->s_es->s_state &= cpu_to_le16(~EXT4_VALID_FS); 1237 mark_buffer_dirty(sbi->s_sbh); 1238 } 1239} 1240 1241/* 1242 * ext4_add_new_descs() adds @count group descriptor of groups 1243 * starting at @group 1244 * 1245 * @handle: journal handle 1246 * @sb: super block 1247 * @group: the group no. of the first group desc to be added 1248 * @resize_inode: the resize inode 1249 * @count: number of group descriptors to be added 1250 */ 1251static int ext4_add_new_descs(handle_t *handle, struct super_block *sb, 1252 ext4_group_t group, struct inode *resize_inode, 1253 ext4_group_t count) 1254{ 1255 struct ext4_sb_info *sbi = EXT4_SB(sb); 1256 struct ext4_super_block *es = sbi->s_es; 1257 struct buffer_head *gdb_bh; 1258 int i, gdb_off, gdb_num, err = 0; 1259 int meta_bg; 1260 1261 meta_bg = ext4_has_feature_meta_bg(sb); 1262 for (i = 0; i < count; i++, group++) { 1263 int reserved_gdb = ext4_bg_has_super(sb, group) ? 1264 le16_to_cpu(es->s_reserved_gdt_blocks) : 0; 1265 1266 gdb_off = group % EXT4_DESC_PER_BLOCK(sb); 1267 gdb_num = group / EXT4_DESC_PER_BLOCK(sb); 1268 1269 /* 1270 * We will only either add reserved group blocks to a backup group 1271 * or remove reserved blocks for the first group in a new group block. 1272 * Doing both would be mean more complex code, and sane people don't 1273 * use non-sparse filesystems anymore. This is already checked above. 1274 */ 1275 if (gdb_off) { 1276 gdb_bh = sbi_array_rcu_deref(sbi, s_group_desc, 1277 gdb_num); 1278 BUFFER_TRACE(gdb_bh, "get_write_access"); 1279 err = ext4_journal_get_write_access(handle, sb, gdb_bh, 1280 EXT4_JTR_NONE); 1281 1282 if (!err && reserved_gdb && ext4_bg_num_gdb(sb, group)) 1283 err = reserve_backup_gdb(handle, resize_inode, group); 1284 } else if (meta_bg != 0) { 1285 err = add_new_gdb_meta_bg(sb, handle, group); 1286 } else { 1287 err = add_new_gdb(handle, resize_inode, group); 1288 } 1289 if (err) 1290 break; 1291 } 1292 return err; 1293} 1294 1295static struct buffer_head *ext4_get_bitmap(struct super_block *sb, __u64 block) 1296{ 1297 struct buffer_head *bh = sb_getblk(sb, block); 1298 if (unlikely(!bh)) 1299 return NULL; 1300 if (!bh_uptodate_or_lock(bh)) { 1301 if (ext4_read_bh(bh, 0, NULL) < 0) { 1302 brelse(bh); 1303 return NULL; 1304 } 1305 } 1306 1307 return bh; 1308} 1309 1310static int ext4_set_bitmap_checksums(struct super_block *sb, 1311 struct ext4_group_desc *gdp, 1312 struct ext4_new_group_data *group_data) 1313{ 1314 struct buffer_head *bh; 1315 1316 if (!ext4_has_metadata_csum(sb)) 1317 return 0; 1318 1319 bh = ext4_get_bitmap(sb, group_data->inode_bitmap); 1320 if (!bh) 1321 return -EIO; 1322 ext4_inode_bitmap_csum_set(sb, gdp, bh, 1323 EXT4_INODES_PER_GROUP(sb) / 8); 1324 brelse(bh); 1325 1326 bh = ext4_get_bitmap(sb, group_data->block_bitmap); 1327 if (!bh) 1328 return -EIO; 1329 ext4_block_bitmap_csum_set(sb, gdp, bh); 1330 brelse(bh); 1331 1332 return 0; 1333} 1334 1335/* 1336 * ext4_setup_new_descs() will set up the group descriptor descriptors of a flex bg 1337 */ 1338static int ext4_setup_new_descs(handle_t *handle, struct super_block *sb, 1339 struct ext4_new_flex_group_data *flex_gd) 1340{ 1341 struct ext4_new_group_data *group_data = flex_gd->groups; 1342 struct ext4_group_desc *gdp; 1343 struct ext4_sb_info *sbi = EXT4_SB(sb); 1344 struct buffer_head *gdb_bh; 1345 ext4_group_t group; 1346 __u16 *bg_flags = flex_gd->bg_flags; 1347 int i, gdb_off, gdb_num, err = 0; 1348 1349 1350 for (i = 0; i < flex_gd->count; i++, group_data++, bg_flags++) { 1351 group = group_data->group; 1352 1353 gdb_off = group % EXT4_DESC_PER_BLOCK(sb); 1354 gdb_num = group / EXT4_DESC_PER_BLOCK(sb); 1355 1356 /* 1357 * get_write_access() has been called on gdb_bh by ext4_add_new_desc(). 1358 */ 1359 gdb_bh = sbi_array_rcu_deref(sbi, s_group_desc, gdb_num); 1360 /* Update group descriptor block for new group */ 1361 gdp = (struct ext4_group_desc *)(gdb_bh->b_data + 1362 gdb_off * EXT4_DESC_SIZE(sb)); 1363 1364 memset(gdp, 0, EXT4_DESC_SIZE(sb)); 1365 ext4_block_bitmap_set(sb, gdp, group_data->block_bitmap); 1366 ext4_inode_bitmap_set(sb, gdp, group_data->inode_bitmap); 1367 err = ext4_set_bitmap_checksums(sb, gdp, group_data); 1368 if (err) { 1369 ext4_std_error(sb, err); 1370 break; 1371 } 1372 1373 ext4_inode_table_set(sb, gdp, group_data->inode_table); 1374 ext4_free_group_clusters_set(sb, gdp, 1375 group_data->free_clusters_count); 1376 ext4_free_inodes_set(sb, gdp, EXT4_INODES_PER_GROUP(sb)); 1377 if (ext4_has_group_desc_csum(sb)) 1378 ext4_itable_unused_set(sb, gdp, 1379 EXT4_INODES_PER_GROUP(sb)); 1380 gdp->bg_flags = cpu_to_le16(*bg_flags); 1381 ext4_group_desc_csum_set(sb, group, gdp); 1382 1383 err = ext4_handle_dirty_metadata(handle, NULL, gdb_bh); 1384 if (unlikely(err)) { 1385 ext4_std_error(sb, err); 1386 break; 1387 } 1388 1389 /* 1390 * We can allocate memory for mb_alloc based on the new group 1391 * descriptor 1392 */ 1393 err = ext4_mb_add_groupinfo(sb, group, gdp); 1394 if (err) 1395 break; 1396 } 1397 return err; 1398} 1399 1400static void ext4_add_overhead(struct super_block *sb, 1401 const ext4_fsblk_t overhead) 1402{ 1403 struct ext4_sb_info *sbi = EXT4_SB(sb); 1404 struct ext4_super_block *es = sbi->s_es; 1405 1406 sbi->s_overhead += overhead; 1407 es->s_overhead_clusters = cpu_to_le32(sbi->s_overhead); 1408 smp_wmb(); 1409} 1410 1411/* 1412 * ext4_update_super() updates the super block so that the newly added 1413 * groups can be seen by the filesystem. 1414 * 1415 * @sb: super block 1416 * @flex_gd: new added groups 1417 */ 1418static void ext4_update_super(struct super_block *sb, 1419 struct ext4_new_flex_group_data *flex_gd) 1420{ 1421 ext4_fsblk_t blocks_count = 0; 1422 ext4_fsblk_t free_blocks = 0; 1423 ext4_fsblk_t reserved_blocks = 0; 1424 struct ext4_new_group_data *group_data = flex_gd->groups; 1425 struct ext4_sb_info *sbi = EXT4_SB(sb); 1426 struct ext4_super_block *es = sbi->s_es; 1427 int i; 1428 1429 BUG_ON(flex_gd->count == 0 || group_data == NULL); 1430 /* 1431 * Make the new blocks and inodes valid next. We do this before 1432 * increasing the group count so that once the group is enabled, 1433 * all of its blocks and inodes are already valid. 1434 * 1435 * We always allocate group-by-group, then block-by-block or 1436 * inode-by-inode within a group, so enabling these 1437 * blocks/inodes before the group is live won't actually let us 1438 * allocate the new space yet. 1439 */ 1440 for (i = 0; i < flex_gd->count; i++) { 1441 blocks_count += group_data[i].blocks_count; 1442 free_blocks += EXT4_C2B(sbi, group_data[i].free_clusters_count); 1443 } 1444 1445 reserved_blocks = ext4_r_blocks_count(es) * 100; 1446 reserved_blocks = div64_u64(reserved_blocks, ext4_blocks_count(es)); 1447 reserved_blocks *= blocks_count; 1448 do_div(reserved_blocks, 100); 1449 1450 lock_buffer(sbi->s_sbh); 1451 ext4_blocks_count_set(es, ext4_blocks_count(es) + blocks_count); 1452 ext4_free_blocks_count_set(es, ext4_free_blocks_count(es) + free_blocks); 1453 le32_add_cpu(&es->s_inodes_count, EXT4_INODES_PER_GROUP(sb) * 1454 flex_gd->count); 1455 le32_add_cpu(&es->s_free_inodes_count, EXT4_INODES_PER_GROUP(sb) * 1456 flex_gd->count); 1457 1458 ext4_debug("free blocks count %llu", ext4_free_blocks_count(es)); 1459 /* 1460 * We need to protect s_groups_count against other CPUs seeing 1461 * inconsistent state in the superblock. 1462 * 1463 * The precise rules we use are: 1464 * 1465 * * Writers must perform a smp_wmb() after updating all 1466 * dependent data and before modifying the groups count 1467 * 1468 * * Readers must perform an smp_rmb() after reading the groups 1469 * count and before reading any dependent data. 1470 * 1471 * NB. These rules can be relaxed when checking the group count 1472 * while freeing data, as we can only allocate from a block 1473 * group after serialising against the group count, and we can 1474 * only then free after serialising in turn against that 1475 * allocation. 1476 */ 1477 smp_wmb(); 1478 1479 /* Update the global fs size fields */ 1480 sbi->s_groups_count += flex_gd->count; 1481 sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count, 1482 (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb))); 1483 1484 /* Update the reserved block counts only once the new group is 1485 * active. */ 1486 ext4_r_blocks_count_set(es, ext4_r_blocks_count(es) + 1487 reserved_blocks); 1488 1489 /* Update the free space counts */ 1490 percpu_counter_add(&sbi->s_freeclusters_counter, 1491 EXT4_NUM_B2C(sbi, free_blocks)); 1492 percpu_counter_add(&sbi->s_freeinodes_counter, 1493 EXT4_INODES_PER_GROUP(sb) * flex_gd->count); 1494 1495 ext4_debug("free blocks count %llu", 1496 percpu_counter_read(&sbi->s_freeclusters_counter)); 1497 if (ext4_has_feature_flex_bg(sb) && sbi->s_log_groups_per_flex) { 1498 ext4_group_t flex_group; 1499 struct flex_groups *fg; 1500 1501 flex_group = ext4_flex_group(sbi, group_data[0].group); 1502 fg = sbi_array_rcu_deref(sbi, s_flex_groups, flex_group); 1503 atomic64_add(EXT4_NUM_B2C(sbi, free_blocks), 1504 &fg->free_clusters); 1505 atomic_add(EXT4_INODES_PER_GROUP(sb) * flex_gd->count, 1506 &fg->free_inodes); 1507 } 1508 1509 /* 1510 * Update the fs overhead information. 1511 * 1512 * For bigalloc, if the superblock already has a properly calculated 1513 * overhead, update it with a value based on numbers already computed 1514 * above for the newly allocated capacity. 1515 */ 1516 if (ext4_has_feature_bigalloc(sb) && (sbi->s_overhead != 0)) 1517 ext4_add_overhead(sb, 1518 EXT4_NUM_B2C(sbi, blocks_count - free_blocks)); 1519 else 1520 ext4_calculate_overhead(sb); 1521 es->s_overhead_clusters = cpu_to_le32(sbi->s_overhead); 1522 1523 ext4_superblock_csum_set(sb); 1524 unlock_buffer(sbi->s_sbh); 1525 if (test_opt(sb, DEBUG)) 1526 printk(KERN_DEBUG "EXT4-fs: added group %u:" 1527 "%llu blocks(%llu free %llu reserved)\n", flex_gd->count, 1528 blocks_count, free_blocks, reserved_blocks); 1529} 1530 1531/* Add a flex group to an fs. Ensure we handle all possible error conditions 1532 * _before_ we start modifying the filesystem, because we cannot abort the 1533 * transaction and not have it write the data to disk. 1534 */ 1535static int ext4_flex_group_add(struct super_block *sb, 1536 struct inode *resize_inode, 1537 struct ext4_new_flex_group_data *flex_gd) 1538{ 1539 struct ext4_sb_info *sbi = EXT4_SB(sb); 1540 struct ext4_super_block *es = sbi->s_es; 1541 ext4_fsblk_t o_blocks_count; 1542 ext4_grpblk_t last; 1543 ext4_group_t group; 1544 handle_t *handle; 1545 unsigned reserved_gdb; 1546 int err = 0, err2 = 0, credit; 1547 1548 BUG_ON(!flex_gd->count || !flex_gd->groups || !flex_gd->bg_flags); 1549 1550 reserved_gdb = le16_to_cpu(es->s_reserved_gdt_blocks); 1551 o_blocks_count = ext4_blocks_count(es); 1552 ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last); 1553 BUG_ON(last); 1554 1555 err = setup_new_flex_group_blocks(sb, flex_gd); 1556 if (err) 1557 goto exit; 1558 /* 1559 * We will always be modifying at least the superblock and GDT 1560 * blocks. If we are adding a group past the last current GDT block, 1561 * we will also modify the inode and the dindirect block. If we 1562 * are adding a group with superblock/GDT backups we will also 1563 * modify each of the reserved GDT dindirect blocks. 1564 */ 1565 credit = 3; /* sb, resize inode, resize inode dindirect */ 1566 /* GDT blocks */ 1567 credit += 1 + DIV_ROUND_UP(flex_gd->count, EXT4_DESC_PER_BLOCK(sb)); 1568 credit += reserved_gdb; /* Reserved GDT dindirect blocks */ 1569 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, credit); 1570 if (IS_ERR(handle)) { 1571 err = PTR_ERR(handle); 1572 goto exit; 1573 } 1574 1575 BUFFER_TRACE(sbi->s_sbh, "get_write_access"); 1576 err = ext4_journal_get_write_access(handle, sb, sbi->s_sbh, 1577 EXT4_JTR_NONE); 1578 if (err) 1579 goto exit_journal; 1580 1581 group = flex_gd->groups[0].group; 1582 BUG_ON(group != sbi->s_groups_count); 1583 err = ext4_add_new_descs(handle, sb, group, 1584 resize_inode, flex_gd->count); 1585 if (err) 1586 goto exit_journal; 1587 1588 err = ext4_setup_new_descs(handle, sb, flex_gd); 1589 if (err) 1590 goto exit_journal; 1591 1592 ext4_update_super(sb, flex_gd); 1593 1594 err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh); 1595 1596exit_journal: 1597 err2 = ext4_journal_stop(handle); 1598 if (!err) 1599 err = err2; 1600 1601 if (!err) { 1602 int gdb_num = group / EXT4_DESC_PER_BLOCK(sb); 1603 int gdb_num_end = ((group + flex_gd->count - 1) / 1604 EXT4_DESC_PER_BLOCK(sb)); 1605 int meta_bg = ext4_has_feature_meta_bg(sb) && 1606 gdb_num >= le32_to_cpu(es->s_first_meta_bg); 1607 sector_t padding_blocks = meta_bg ? 0 : sbi->s_sbh->b_blocknr - 1608 ext4_group_first_block_no(sb, 0); 1609 1610 update_backups(sb, ext4_group_first_block_no(sb, 0), 1611 (char *)es, sizeof(struct ext4_super_block), 0); 1612 for (; gdb_num <= gdb_num_end; gdb_num++) { 1613 struct buffer_head *gdb_bh; 1614 1615 gdb_bh = sbi_array_rcu_deref(sbi, s_group_desc, 1616 gdb_num); 1617 update_backups(sb, gdb_bh->b_blocknr - padding_blocks, 1618 gdb_bh->b_data, gdb_bh->b_size, meta_bg); 1619 } 1620 } 1621exit: 1622 return err; 1623} 1624 1625static int ext4_setup_next_flex_gd(struct super_block *sb, 1626 struct ext4_new_flex_group_data *flex_gd, 1627 ext4_fsblk_t n_blocks_count) 1628{ 1629 struct ext4_sb_info *sbi = EXT4_SB(sb); 1630 struct ext4_super_block *es = sbi->s_es; 1631 struct ext4_new_group_data *group_data = flex_gd->groups; 1632 ext4_fsblk_t o_blocks_count; 1633 ext4_group_t n_group; 1634 ext4_group_t group; 1635 ext4_group_t last_group; 1636 ext4_grpblk_t last; 1637 ext4_grpblk_t clusters_per_group; 1638 unsigned long i; 1639 1640 clusters_per_group = EXT4_CLUSTERS_PER_GROUP(sb); 1641 1642 o_blocks_count = ext4_blocks_count(es); 1643 1644 if (o_blocks_count == n_blocks_count) 1645 return 0; 1646 1647 ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last); 1648 BUG_ON(last); 1649 ext4_get_group_no_and_offset(sb, n_blocks_count - 1, &n_group, &last); 1650 1651 last_group = group | (flex_gd->resize_bg - 1); 1652 if (last_group > n_group) 1653 last_group = n_group; 1654 1655 flex_gd->count = last_group - group + 1; 1656 1657 for (i = 0; i < flex_gd->count; i++) { 1658 int overhead; 1659 1660 group_data[i].group = group + i; 1661 group_data[i].blocks_count = EXT4_BLOCKS_PER_GROUP(sb); 1662 overhead = ext4_group_overhead_blocks(sb, group + i); 1663 group_data[i].mdata_blocks = overhead; 1664 group_data[i].free_clusters_count = EXT4_CLUSTERS_PER_GROUP(sb); 1665 if (ext4_has_group_desc_csum(sb)) { 1666 flex_gd->bg_flags[i] = EXT4_BG_BLOCK_UNINIT | 1667 EXT4_BG_INODE_UNINIT; 1668 if (!test_opt(sb, INIT_INODE_TABLE)) 1669 flex_gd->bg_flags[i] |= EXT4_BG_INODE_ZEROED; 1670 } else 1671 flex_gd->bg_flags[i] = EXT4_BG_INODE_ZEROED; 1672 } 1673 1674 if (last_group == n_group && ext4_has_group_desc_csum(sb)) 1675 /* We need to initialize block bitmap of last group. */ 1676 flex_gd->bg_flags[i - 1] &= ~EXT4_BG_BLOCK_UNINIT; 1677 1678 if ((last_group == n_group) && (last != clusters_per_group - 1)) { 1679 group_data[i - 1].blocks_count = EXT4_C2B(sbi, last + 1); 1680 group_data[i - 1].free_clusters_count -= clusters_per_group - 1681 last - 1; 1682 } 1683 1684 return 1; 1685} 1686 1687/* Add group descriptor data to an existing or new group descriptor block. 1688 * Ensure we handle all possible error conditions _before_ we start modifying 1689 * the filesystem, because we cannot abort the transaction and not have it 1690 * write the data to disk. 1691 * 1692 * If we are on a GDT block boundary, we need to get the reserved GDT block. 1693 * Otherwise, we may need to add backup GDT blocks for a sparse group. 1694 * 1695 * We only need to hold the superblock lock while we are actually adding 1696 * in the new group's counts to the superblock. Prior to that we have 1697 * not really "added" the group at all. We re-check that we are still 1698 * adding in the last group in case things have changed since verifying. 1699 */ 1700int ext4_group_add(struct super_block *sb, struct ext4_new_group_data *input) 1701{ 1702 struct ext4_new_flex_group_data flex_gd; 1703 struct ext4_sb_info *sbi = EXT4_SB(sb); 1704 struct ext4_super_block *es = sbi->s_es; 1705 int reserved_gdb = ext4_bg_has_super(sb, input->group) ? 1706 le16_to_cpu(es->s_reserved_gdt_blocks) : 0; 1707 struct inode *inode = NULL; 1708 int gdb_off; 1709 int err; 1710 __u16 bg_flags = 0; 1711 1712 gdb_off = input->group % EXT4_DESC_PER_BLOCK(sb); 1713 1714 if (gdb_off == 0 && !ext4_has_feature_sparse_super(sb)) { 1715 ext4_warning(sb, "Can't resize non-sparse filesystem further"); 1716 return -EPERM; 1717 } 1718 1719 if (ext4_blocks_count(es) + input->blocks_count < 1720 ext4_blocks_count(es)) { 1721 ext4_warning(sb, "blocks_count overflow"); 1722 return -EINVAL; 1723 } 1724 1725 if (le32_to_cpu(es->s_inodes_count) + EXT4_INODES_PER_GROUP(sb) < 1726 le32_to_cpu(es->s_inodes_count)) { 1727 ext4_warning(sb, "inodes_count overflow"); 1728 return -EINVAL; 1729 } 1730 1731 if (reserved_gdb || gdb_off == 0) { 1732 if (!ext4_has_feature_resize_inode(sb) || 1733 !le16_to_cpu(es->s_reserved_gdt_blocks)) { 1734 ext4_warning(sb, 1735 "No reserved GDT blocks, can't resize"); 1736 return -EPERM; 1737 } 1738 inode = ext4_iget(sb, EXT4_RESIZE_INO, EXT4_IGET_SPECIAL); 1739 if (IS_ERR(inode)) { 1740 ext4_warning(sb, "Error opening resize inode"); 1741 return PTR_ERR(inode); 1742 } 1743 } 1744 1745 1746 err = verify_group_input(sb, input); 1747 if (err) 1748 goto out; 1749 1750 err = ext4_alloc_flex_bg_array(sb, input->group + 1); 1751 if (err) 1752 goto out; 1753 1754 err = ext4_mb_alloc_groupinfo(sb, input->group + 1); 1755 if (err) 1756 goto out; 1757 1758 flex_gd.count = 1; 1759 flex_gd.groups = input; 1760 flex_gd.bg_flags = &bg_flags; 1761 err = ext4_flex_group_add(sb, inode, &flex_gd); 1762out: 1763 iput(inode); 1764 return err; 1765} /* ext4_group_add */ 1766 1767/* 1768 * extend a group without checking assuming that checking has been done. 1769 */ 1770static int ext4_group_extend_no_check(struct super_block *sb, 1771 ext4_fsblk_t o_blocks_count, ext4_grpblk_t add) 1772{ 1773 struct ext4_super_block *es = EXT4_SB(sb)->s_es; 1774 handle_t *handle; 1775 int err = 0, err2; 1776 1777 /* We will update the superblock, one block bitmap, and 1778 * one group descriptor via ext4_group_add_blocks(). 1779 */ 1780 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, 3); 1781 if (IS_ERR(handle)) { 1782 err = PTR_ERR(handle); 1783 ext4_warning(sb, "error %d on journal start", err); 1784 return err; 1785 } 1786 1787 BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get_write_access"); 1788 err = ext4_journal_get_write_access(handle, sb, EXT4_SB(sb)->s_sbh, 1789 EXT4_JTR_NONE); 1790 if (err) { 1791 ext4_warning(sb, "error %d on journal write access", err); 1792 goto errout; 1793 } 1794 1795 lock_buffer(EXT4_SB(sb)->s_sbh); 1796 ext4_blocks_count_set(es, o_blocks_count + add); 1797 ext4_free_blocks_count_set(es, ext4_free_blocks_count(es) + add); 1798 ext4_superblock_csum_set(sb); 1799 unlock_buffer(EXT4_SB(sb)->s_sbh); 1800 ext4_debug("freeing blocks %llu through %llu\n", o_blocks_count, 1801 o_blocks_count + add); 1802 /* We add the blocks to the bitmap and set the group need init bit */ 1803 err = ext4_group_add_blocks(handle, sb, o_blocks_count, add); 1804 if (err) 1805 goto errout; 1806 ext4_handle_dirty_metadata(handle, NULL, EXT4_SB(sb)->s_sbh); 1807 ext4_debug("freed blocks %llu through %llu\n", o_blocks_count, 1808 o_blocks_count + add); 1809errout: 1810 err2 = ext4_journal_stop(handle); 1811 if (err2 && !err) 1812 err = err2; 1813 1814 if (!err) { 1815 if (test_opt(sb, DEBUG)) 1816 printk(KERN_DEBUG "EXT4-fs: extended group to %llu " 1817 "blocks\n", ext4_blocks_count(es)); 1818 update_backups(sb, ext4_group_first_block_no(sb, 0), 1819 (char *)es, sizeof(struct ext4_super_block), 0); 1820 } 1821 return err; 1822} 1823 1824/* 1825 * Extend the filesystem to the new number of blocks specified. This entry 1826 * point is only used to extend the current filesystem to the end of the last 1827 * existing group. It can be accessed via ioctl, or by "remount,resize=<size>" 1828 * for emergencies (because it has no dependencies on reserved blocks). 1829 * 1830 * If we _really_ wanted, we could use default values to call ext4_group_add() 1831 * allow the "remount" trick to work for arbitrary resizing, assuming enough 1832 * GDT blocks are reserved to grow to the desired size. 1833 */ 1834int ext4_group_extend(struct super_block *sb, struct ext4_super_block *es, 1835 ext4_fsblk_t n_blocks_count) 1836{ 1837 ext4_fsblk_t o_blocks_count; 1838 ext4_grpblk_t last; 1839 ext4_grpblk_t add; 1840 struct buffer_head *bh; 1841 ext4_group_t group; 1842 1843 o_blocks_count = ext4_blocks_count(es); 1844 1845 if (test_opt(sb, DEBUG)) 1846 ext4_msg(sb, KERN_DEBUG, 1847 "extending last group from %llu to %llu blocks", 1848 o_blocks_count, n_blocks_count); 1849 1850 if (n_blocks_count == 0 || n_blocks_count == o_blocks_count) 1851 return 0; 1852 1853 if (n_blocks_count > (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) { 1854 ext4_msg(sb, KERN_ERR, 1855 "filesystem too large to resize to %llu blocks safely", 1856 n_blocks_count); 1857 return -EINVAL; 1858 } 1859 1860 if (n_blocks_count < o_blocks_count) { 1861 ext4_warning(sb, "can't shrink FS - resize aborted"); 1862 return -EINVAL; 1863 } 1864 1865 /* Handle the remaining blocks in the last group only. */ 1866 ext4_get_group_no_and_offset(sb, o_blocks_count, &group, &last); 1867 1868 if (last == 0) { 1869 ext4_warning(sb, "need to use ext2online to resize further"); 1870 return -EPERM; 1871 } 1872 1873 add = EXT4_BLOCKS_PER_GROUP(sb) - last; 1874 1875 if (o_blocks_count + add < o_blocks_count) { 1876 ext4_warning(sb, "blocks_count overflow"); 1877 return -EINVAL; 1878 } 1879 1880 if (o_blocks_count + add > n_blocks_count) 1881 add = n_blocks_count - o_blocks_count; 1882 1883 if (o_blocks_count + add < n_blocks_count) 1884 ext4_warning(sb, "will only finish group (%llu blocks, %u new)", 1885 o_blocks_count + add, add); 1886 1887 /* See if the device is actually as big as what was requested */ 1888 bh = ext4_sb_bread(sb, o_blocks_count + add - 1, 0); 1889 if (IS_ERR(bh)) { 1890 ext4_warning(sb, "can't read last block, resize aborted"); 1891 return -ENOSPC; 1892 } 1893 brelse(bh); 1894 1895 return ext4_group_extend_no_check(sb, o_blocks_count, add); 1896} /* ext4_group_extend */ 1897 1898 1899static int num_desc_blocks(struct super_block *sb, ext4_group_t groups) 1900{ 1901 return (groups + EXT4_DESC_PER_BLOCK(sb) - 1) / EXT4_DESC_PER_BLOCK(sb); 1902} 1903 1904/* 1905 * Release the resize inode and drop the resize_inode feature if there 1906 * are no more reserved gdt blocks, and then convert the file system 1907 * to enable meta_bg 1908 */ 1909static int ext4_convert_meta_bg(struct super_block *sb, struct inode *inode) 1910{ 1911 handle_t *handle; 1912 struct ext4_sb_info *sbi = EXT4_SB(sb); 1913 struct ext4_super_block *es = sbi->s_es; 1914 struct ext4_inode_info *ei = EXT4_I(inode); 1915 ext4_fsblk_t nr; 1916 int i, ret, err = 0; 1917 int credits = 1; 1918 1919 ext4_msg(sb, KERN_INFO, "Converting file system to meta_bg"); 1920 if (inode) { 1921 if (es->s_reserved_gdt_blocks) { 1922 ext4_error(sb, "Unexpected non-zero " 1923 "s_reserved_gdt_blocks"); 1924 return -EPERM; 1925 } 1926 1927 /* Do a quick sanity check of the resize inode */ 1928 if (inode->i_blocks != 1 << (inode->i_blkbits - 1929 (9 - sbi->s_cluster_bits))) 1930 goto invalid_resize_inode; 1931 for (i = 0; i < EXT4_N_BLOCKS; i++) { 1932 if (i == EXT4_DIND_BLOCK) { 1933 if (ei->i_data[i]) 1934 continue; 1935 else 1936 goto invalid_resize_inode; 1937 } 1938 if (ei->i_data[i]) 1939 goto invalid_resize_inode; 1940 } 1941 credits += 3; /* block bitmap, bg descriptor, resize inode */ 1942 } 1943 1944 handle = ext4_journal_start_sb(sb, EXT4_HT_RESIZE, credits); 1945 if (IS_ERR(handle)) 1946 return PTR_ERR(handle); 1947 1948 BUFFER_TRACE(sbi->s_sbh, "get_write_access"); 1949 err = ext4_journal_get_write_access(handle, sb, sbi->s_sbh, 1950 EXT4_JTR_NONE); 1951 if (err) 1952 goto errout; 1953 1954 lock_buffer(sbi->s_sbh); 1955 ext4_clear_feature_resize_inode(sb); 1956 ext4_set_feature_meta_bg(sb); 1957 sbi->s_es->s_first_meta_bg = 1958 cpu_to_le32(num_desc_blocks(sb, sbi->s_groups_count)); 1959 ext4_superblock_csum_set(sb); 1960 unlock_buffer(sbi->s_sbh); 1961 1962 err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh); 1963 if (err) { 1964 ext4_std_error(sb, err); 1965 goto errout; 1966 } 1967 1968 if (inode) { 1969 nr = le32_to_cpu(ei->i_data[EXT4_DIND_BLOCK]); 1970 ext4_free_blocks(handle, inode, NULL, nr, 1, 1971 EXT4_FREE_BLOCKS_METADATA | 1972 EXT4_FREE_BLOCKS_FORGET); 1973 ei->i_data[EXT4_DIND_BLOCK] = 0; 1974 inode->i_blocks = 0; 1975 1976 err = ext4_mark_inode_dirty(handle, inode); 1977 if (err) 1978 ext4_std_error(sb, err); 1979 } 1980 1981errout: 1982 ret = ext4_journal_stop(handle); 1983 return err ? err : ret; 1984 1985invalid_resize_inode: 1986 ext4_error(sb, "corrupted/inconsistent resize inode"); 1987 return -EINVAL; 1988} 1989 1990/* 1991 * ext4_resize_fs() resizes a fs to new size specified by @n_blocks_count 1992 * 1993 * @sb: super block of the fs to be resized 1994 * @n_blocks_count: the number of blocks resides in the resized fs 1995 */ 1996int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count) 1997{ 1998 struct ext4_new_flex_group_data *flex_gd = NULL; 1999 struct ext4_sb_info *sbi = EXT4_SB(sb); 2000 struct ext4_super_block *es = sbi->s_es; 2001 struct buffer_head *bh; 2002 struct inode *resize_inode = NULL; 2003 ext4_grpblk_t add, offset; 2004 unsigned long n_desc_blocks; 2005 unsigned long o_desc_blocks; 2006 ext4_group_t o_group; 2007 ext4_group_t n_group; 2008 ext4_fsblk_t o_blocks_count; 2009 ext4_fsblk_t n_blocks_count_retry = 0; 2010 unsigned long last_update_time = 0; 2011 int err = 0; 2012 int meta_bg; 2013 unsigned int flexbg_size = ext4_flex_bg_size(sbi); 2014 2015 /* See if the device is actually as big as what was requested */ 2016 bh = ext4_sb_bread(sb, n_blocks_count - 1, 0); 2017 if (IS_ERR(bh)) { 2018 ext4_warning(sb, "can't read last block, resize aborted"); 2019 return -ENOSPC; 2020 } 2021 brelse(bh); 2022 2023 /* 2024 * For bigalloc, trim the requested size to the nearest cluster 2025 * boundary to avoid creating an unusable filesystem. We do this 2026 * silently, instead of returning an error, to avoid breaking 2027 * callers that blindly resize the filesystem to the full size of 2028 * the underlying block device. 2029 */ 2030 if (ext4_has_feature_bigalloc(sb)) 2031 n_blocks_count &= ~((1 << EXT4_CLUSTER_BITS(sb)) - 1); 2032 2033retry: 2034 o_blocks_count = ext4_blocks_count(es); 2035 2036 ext4_msg(sb, KERN_INFO, "resizing filesystem from %llu " 2037 "to %llu blocks", o_blocks_count, n_blocks_count); 2038 2039 if (n_blocks_count < o_blocks_count) { 2040 /* On-line shrinking not supported */ 2041 ext4_warning(sb, "can't shrink FS - resize aborted"); 2042 return -EINVAL; 2043 } 2044 2045 if (n_blocks_count == o_blocks_count) 2046 /* Nothing need to do */ 2047 return 0; 2048 2049 n_group = ext4_get_group_number(sb, n_blocks_count - 1); 2050 if (n_group >= (0xFFFFFFFFUL / EXT4_INODES_PER_GROUP(sb))) { 2051 ext4_warning(sb, "resize would cause inodes_count overflow"); 2052 return -EINVAL; 2053 } 2054 ext4_get_group_no_and_offset(sb, o_blocks_count - 1, &o_group, &offset); 2055 2056 n_desc_blocks = num_desc_blocks(sb, n_group + 1); 2057 o_desc_blocks = num_desc_blocks(sb, sbi->s_groups_count); 2058 2059 meta_bg = ext4_has_feature_meta_bg(sb); 2060 2061 if (ext4_has_feature_resize_inode(sb)) { 2062 if (meta_bg) { 2063 ext4_error(sb, "resize_inode and meta_bg enabled " 2064 "simultaneously"); 2065 return -EINVAL; 2066 } 2067 if (n_desc_blocks > o_desc_blocks + 2068 le16_to_cpu(es->s_reserved_gdt_blocks)) { 2069 n_blocks_count_retry = n_blocks_count; 2070 n_desc_blocks = o_desc_blocks + 2071 le16_to_cpu(es->s_reserved_gdt_blocks); 2072 n_group = n_desc_blocks * EXT4_DESC_PER_BLOCK(sb); 2073 n_blocks_count = (ext4_fsblk_t)n_group * 2074 EXT4_BLOCKS_PER_GROUP(sb) + 2075 le32_to_cpu(es->s_first_data_block); 2076 n_group--; /* set to last group number */ 2077 } 2078 2079 if (!resize_inode) 2080 resize_inode = ext4_iget(sb, EXT4_RESIZE_INO, 2081 EXT4_IGET_SPECIAL); 2082 if (IS_ERR(resize_inode)) { 2083 ext4_warning(sb, "Error opening resize inode"); 2084 return PTR_ERR(resize_inode); 2085 } 2086 } 2087 2088 if ((!resize_inode && !meta_bg && n_desc_blocks > o_desc_blocks) || n_blocks_count == o_blocks_count) { 2089 err = ext4_convert_meta_bg(sb, resize_inode); 2090 if (err) 2091 goto out; 2092 if (resize_inode) { 2093 iput(resize_inode); 2094 resize_inode = NULL; 2095 } 2096 if (n_blocks_count_retry) { 2097 n_blocks_count = n_blocks_count_retry; 2098 n_blocks_count_retry = 0; 2099 goto retry; 2100 } 2101 } 2102 2103 /* 2104 * Make sure the last group has enough space so that it's 2105 * guaranteed to have enough space for all metadata blocks 2106 * that it might need to hold. (We might not need to store 2107 * the inode table blocks in the last block group, but there 2108 * will be cases where this might be needed.) 2109 */ 2110 if ((ext4_group_first_block_no(sb, n_group) + 2111 ext4_group_overhead_blocks(sb, n_group) + 2 + 2112 sbi->s_itb_per_group + sbi->s_cluster_ratio) >= n_blocks_count) { 2113 n_blocks_count = ext4_group_first_block_no(sb, n_group); 2114 n_group--; 2115 n_blocks_count_retry = 0; 2116 if (resize_inode) { 2117 iput(resize_inode); 2118 resize_inode = NULL; 2119 } 2120 goto retry; 2121 } 2122 2123 /* extend the last group */ 2124 if (n_group == o_group) 2125 add = n_blocks_count - o_blocks_count; 2126 else 2127 add = EXT4_C2B(sbi, EXT4_CLUSTERS_PER_GROUP(sb) - (offset + 1)); 2128 if (add > 0) { 2129 err = ext4_group_extend_no_check(sb, o_blocks_count, add); 2130 if (err) 2131 goto out; 2132 } 2133 2134 if (ext4_blocks_count(es) == n_blocks_count && n_blocks_count_retry == 0) 2135 goto out; 2136 2137 err = ext4_alloc_flex_bg_array(sb, n_group + 1); 2138 if (err) 2139 goto out; 2140 2141 err = ext4_mb_alloc_groupinfo(sb, n_group + 1); 2142 if (err) 2143 goto out; 2144 2145 flex_gd = alloc_flex_gd(flexbg_size, o_group, n_group); 2146 if (flex_gd == NULL) { 2147 err = -ENOMEM; 2148 goto out; 2149 } 2150 2151 /* Add flex groups. Note that a regular group is a 2152 * flex group with 1 group. 2153 */ 2154 while (ext4_setup_next_flex_gd(sb, flex_gd, n_blocks_count)) { 2155 if (time_is_before_jiffies(last_update_time + HZ * 10)) { 2156 if (last_update_time) 2157 ext4_msg(sb, KERN_INFO, 2158 "resized to %llu blocks", 2159 ext4_blocks_count(es)); 2160 last_update_time = jiffies; 2161 } 2162 if (ext4_alloc_group_tables(sb, flex_gd, flexbg_size) != 0) 2163 break; 2164 err = ext4_flex_group_add(sb, resize_inode, flex_gd); 2165 if (unlikely(err)) 2166 break; 2167 } 2168 2169 if (!err && n_blocks_count_retry) { 2170 n_blocks_count = n_blocks_count_retry; 2171 n_blocks_count_retry = 0; 2172 free_flex_gd(flex_gd); 2173 flex_gd = NULL; 2174 if (resize_inode) { 2175 iput(resize_inode); 2176 resize_inode = NULL; 2177 } 2178 goto retry; 2179 } 2180 2181out: 2182 if (flex_gd) 2183 free_flex_gd(flex_gd); 2184 if (resize_inode != NULL) 2185 iput(resize_inode); 2186 if (err) 2187 ext4_warning(sb, "error (%d) occurred during " 2188 "file system resize", err); 2189 ext4_msg(sb, KERN_INFO, "resized filesystem to %llu", 2190 ext4_blocks_count(es)); 2191 return err; 2192} 2193