1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * recovery.c - NILFS recovery logic 4 * 5 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation. 6 * 7 * Written by Ryusuke Konishi. 8 */ 9 10 #include <linux/buffer_head.h> 11 #include <linux/blkdev.h> 12 #include <linux/swap.h> 13 #include <linux/slab.h> 14 #include <linux/crc32.h> 15 #include "nilfs.h" 16 #include "segment.h" 17 #include "sufile.h" 18 #include "page.h" 19 #include "segbuf.h" 20 21 /* 22 * Segment check result 23 */ 24 enum { 25 NILFS_SEG_VALID, 26 NILFS_SEG_NO_SUPER_ROOT, 27 NILFS_SEG_FAIL_IO, 28 NILFS_SEG_FAIL_MAGIC, 29 NILFS_SEG_FAIL_SEQ, 30 NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT, 31 NILFS_SEG_FAIL_CHECKSUM_FULL, 32 NILFS_SEG_FAIL_CONSISTENCY, 33 }; 34 35 /* work structure for recovery */ 36 struct nilfs_recovery_block { 37 ino_t ino; /* 38 * Inode number of the file that this block 39 * belongs to 40 */ 41 sector_t blocknr; /* block number */ 42 __u64 vblocknr; /* virtual block number */ 43 unsigned long blkoff; /* File offset of the data block (per block) */ 44 struct list_head list; 45 }; 46 47 48 static int nilfs_warn_segment_error(struct super_block *sb, int err) 49 { 50 const char *msg = NULL; 51 52 switch (err) { 53 case NILFS_SEG_FAIL_IO: 54 nilfs_err(sb, "I/O error reading segment"); 55 return -EIO; 56 case NILFS_SEG_FAIL_MAGIC: 57 msg = "Magic number mismatch"; 58 break; 59 case NILFS_SEG_FAIL_SEQ: 60 msg = "Sequence number mismatch"; 61 break; 62 case NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT: 63 msg = "Checksum error in super root"; 64 break; 65 case NILFS_SEG_FAIL_CHECKSUM_FULL: 66 msg = "Checksum error in segment payload"; 67 break; 68 case NILFS_SEG_FAIL_CONSISTENCY: 69 msg = "Inconsistency found"; 70 break; 71 case NILFS_SEG_NO_SUPER_ROOT: 72 msg = "No super root in the last segment"; 73 break; 74 default: 75 nilfs_err(sb, "unrecognized segment error %d", err); 76 return -EINVAL; 77 } 78 nilfs_warn(sb, "invalid segment: %s", msg); 79 return -EINVAL; 80 } 81 82 /** 83 * nilfs_compute_checksum - compute checksum of blocks continuously 84 * @nilfs: nilfs object 85 * @bhs: buffer head of start block 86 * @sum: place to store result 87 * @offset: offset bytes in the first block 88 * @check_bytes: number of bytes to be checked 89 * @start: DBN of start block 90 * @nblock: number of blocks to be checked 91 */ 92 static int nilfs_compute_checksum(struct the_nilfs *nilfs, 93 struct buffer_head *bhs, u32 *sum, 94 unsigned long offset, u64 check_bytes, 95 sector_t start, unsigned long nblock) 96 { 97 unsigned int blocksize = nilfs->ns_blocksize; 98 unsigned long size; 99 u32 crc; 100 101 BUG_ON(offset >= blocksize); 102 check_bytes -= offset; 103 size = min_t(u64, check_bytes, blocksize - offset); 104 crc = crc32_le(nilfs->ns_crc_seed, 105 (unsigned char *)bhs->b_data + offset, size); 106 if (--nblock > 0) { 107 do { 108 struct buffer_head *bh; 109 110 bh = __bread(nilfs->ns_bdev, ++start, blocksize); 111 if (!bh) 112 return -EIO; 113 check_bytes -= size; 114 size = min_t(u64, check_bytes, blocksize); 115 crc = crc32_le(crc, bh->b_data, size); 116 brelse(bh); 117 } while (--nblock > 0); 118 } 119 *sum = crc; 120 return 0; 121 } 122 123 /** 124 * nilfs_read_super_root_block - read super root block 125 * @nilfs: nilfs object 126 * @sr_block: disk block number of the super root block 127 * @pbh: address of a buffer_head pointer to return super root buffer 128 * @check: CRC check flag 129 */ 130 int nilfs_read_super_root_block(struct the_nilfs *nilfs, sector_t sr_block, 131 struct buffer_head **pbh, int check) 132 { 133 struct buffer_head *bh_sr; 134 struct nilfs_super_root *sr; 135 u32 crc; 136 int ret; 137 138 *pbh = NULL; 139 bh_sr = __bread(nilfs->ns_bdev, sr_block, nilfs->ns_blocksize); 140 if (unlikely(!bh_sr)) { 141 ret = NILFS_SEG_FAIL_IO; 142 goto failed; 143 } 144 145 sr = (struct nilfs_super_root *)bh_sr->b_data; 146 if (check) { 147 unsigned int bytes = le16_to_cpu(sr->sr_bytes); 148 149 if (bytes == 0 || bytes > nilfs->ns_blocksize) { 150 ret = NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT; 151 goto failed_bh; 152 } 153 if (nilfs_compute_checksum( 154 nilfs, bh_sr, &crc, sizeof(sr->sr_sum), bytes, 155 sr_block, 1)) { 156 ret = NILFS_SEG_FAIL_IO; 157 goto failed_bh; 158 } 159 if (crc != le32_to_cpu(sr->sr_sum)) { 160 ret = NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT; 161 goto failed_bh; 162 } 163 } 164 *pbh = bh_sr; 165 return 0; 166 167 failed_bh: 168 brelse(bh_sr); 169 170 failed: 171 return nilfs_warn_segment_error(nilfs->ns_sb, ret); 172 } 173 174 /** 175 * nilfs_read_log_header - read summary header of the specified log 176 * @nilfs: nilfs object 177 * @start_blocknr: start block number of the log 178 * @sum: pointer to return segment summary structure 179 */ 180 static struct buffer_head * 181 nilfs_read_log_header(struct the_nilfs *nilfs, sector_t start_blocknr, 182 struct nilfs_segment_summary **sum) 183 { 184 struct buffer_head *bh_sum; 185 186 bh_sum = __bread(nilfs->ns_bdev, start_blocknr, nilfs->ns_blocksize); 187 if (bh_sum) 188 *sum = (struct nilfs_segment_summary *)bh_sum->b_data; 189 return bh_sum; 190 } 191 192 /** 193 * nilfs_validate_log - verify consistency of log 194 * @nilfs: nilfs object 195 * @seg_seq: sequence number of segment 196 * @bh_sum: buffer head of summary block 197 * @sum: segment summary struct 198 */ 199 static int nilfs_validate_log(struct the_nilfs *nilfs, u64 seg_seq, 200 struct buffer_head *bh_sum, 201 struct nilfs_segment_summary *sum) 202 { 203 unsigned long nblock; 204 u32 crc; 205 int ret; 206 207 ret = NILFS_SEG_FAIL_MAGIC; 208 if (le32_to_cpu(sum->ss_magic) != NILFS_SEGSUM_MAGIC) 209 goto out; 210 211 ret = NILFS_SEG_FAIL_SEQ; 212 if (le64_to_cpu(sum->ss_seq) != seg_seq) 213 goto out; 214 215 nblock = le32_to_cpu(sum->ss_nblocks); 216 ret = NILFS_SEG_FAIL_CONSISTENCY; 217 if (unlikely(nblock == 0 || nblock > nilfs->ns_blocks_per_segment)) 218 /* This limits the number of blocks read in the CRC check */ 219 goto out; 220 221 ret = NILFS_SEG_FAIL_IO; 222 if (nilfs_compute_checksum(nilfs, bh_sum, &crc, sizeof(sum->ss_datasum), 223 ((u64)nblock << nilfs->ns_blocksize_bits), 224 bh_sum->b_blocknr, nblock)) 225 goto out; 226 227 ret = NILFS_SEG_FAIL_CHECKSUM_FULL; 228 if (crc != le32_to_cpu(sum->ss_datasum)) 229 goto out; 230 ret = 0; 231 out: 232 return ret; 233 } 234 235 /** 236 * nilfs_read_summary_info - read an item on summary blocks of a log 237 * @nilfs: nilfs object 238 * @pbh: the current buffer head on summary blocks [in, out] 239 * @offset: the current byte offset on summary blocks [in, out] 240 * @bytes: byte size of the item to be read 241 */ 242 static void *nilfs_read_summary_info(struct the_nilfs *nilfs, 243 struct buffer_head **pbh, 244 unsigned int *offset, unsigned int bytes) 245 { 246 void *ptr; 247 sector_t blocknr; 248 249 BUG_ON((*pbh)->b_size < *offset); 250 if (bytes > (*pbh)->b_size - *offset) { 251 blocknr = (*pbh)->b_blocknr; 252 brelse(*pbh); 253 *pbh = __bread(nilfs->ns_bdev, blocknr + 1, 254 nilfs->ns_blocksize); 255 if (unlikely(!*pbh)) 256 return NULL; 257 *offset = 0; 258 } 259 ptr = (*pbh)->b_data + *offset; 260 *offset += bytes; 261 return ptr; 262 } 263 264 /** 265 * nilfs_skip_summary_info - skip items on summary blocks of a log 266 * @nilfs: nilfs object 267 * @pbh: the current buffer head on summary blocks [in, out] 268 * @offset: the current byte offset on summary blocks [in, out] 269 * @bytes: byte size of the item to be skipped 270 * @count: number of items to be skipped 271 */ 272 static void nilfs_skip_summary_info(struct the_nilfs *nilfs, 273 struct buffer_head **pbh, 274 unsigned int *offset, unsigned int bytes, 275 unsigned long count) 276 { 277 unsigned int rest_item_in_current_block 278 = ((*pbh)->b_size - *offset) / bytes; 279 280 if (count <= rest_item_in_current_block) { 281 *offset += bytes * count; 282 } else { 283 sector_t blocknr = (*pbh)->b_blocknr; 284 unsigned int nitem_per_block = (*pbh)->b_size / bytes; 285 unsigned int bcnt; 286 287 count -= rest_item_in_current_block; 288 bcnt = DIV_ROUND_UP(count, nitem_per_block); 289 *offset = bytes * (count - (bcnt - 1) * nitem_per_block); 290 291 brelse(*pbh); 292 *pbh = __bread(nilfs->ns_bdev, blocknr + bcnt, 293 nilfs->ns_blocksize); 294 } 295 } 296 297 /** 298 * nilfs_scan_dsync_log - get block information of a log written for data sync 299 * @nilfs: nilfs object 300 * @start_blocknr: start block number of the log 301 * @sum: log summary information 302 * @head: list head to add nilfs_recovery_block struct 303 */ 304 static int nilfs_scan_dsync_log(struct the_nilfs *nilfs, sector_t start_blocknr, 305 struct nilfs_segment_summary *sum, 306 struct list_head *head) 307 { 308 struct buffer_head *bh; 309 unsigned int offset; 310 u32 nfinfo, sumbytes; 311 sector_t blocknr; 312 ino_t ino; 313 int err = -EIO; 314 315 nfinfo = le32_to_cpu(sum->ss_nfinfo); 316 if (!nfinfo) 317 return 0; 318 319 sumbytes = le32_to_cpu(sum->ss_sumbytes); 320 blocknr = start_blocknr + DIV_ROUND_UP(sumbytes, nilfs->ns_blocksize); 321 bh = __bread(nilfs->ns_bdev, start_blocknr, nilfs->ns_blocksize); 322 if (unlikely(!bh)) 323 goto out; 324 325 offset = le16_to_cpu(sum->ss_bytes); 326 for (;;) { 327 unsigned long nblocks, ndatablk, nnodeblk; 328 struct nilfs_finfo *finfo; 329 330 finfo = nilfs_read_summary_info(nilfs, &bh, &offset, 331 sizeof(*finfo)); 332 if (unlikely(!finfo)) 333 goto out; 334 335 ino = le64_to_cpu(finfo->fi_ino); 336 nblocks = le32_to_cpu(finfo->fi_nblocks); 337 ndatablk = le32_to_cpu(finfo->fi_ndatablk); 338 nnodeblk = nblocks - ndatablk; 339 340 while (ndatablk-- > 0) { 341 struct nilfs_recovery_block *rb; 342 struct nilfs_binfo_v *binfo; 343 344 binfo = nilfs_read_summary_info(nilfs, &bh, &offset, 345 sizeof(*binfo)); 346 if (unlikely(!binfo)) 347 goto out; 348 349 rb = kmalloc(sizeof(*rb), GFP_NOFS); 350 if (unlikely(!rb)) { 351 err = -ENOMEM; 352 goto out; 353 } 354 rb->ino = ino; 355 rb->blocknr = blocknr++; 356 rb->vblocknr = le64_to_cpu(binfo->bi_vblocknr); 357 rb->blkoff = le64_to_cpu(binfo->bi_blkoff); 358 /* INIT_LIST_HEAD(&rb->list); */ 359 list_add_tail(&rb->list, head); 360 } 361 if (--nfinfo == 0) 362 break; 363 blocknr += nnodeblk; /* always 0 for data sync logs */ 364 nilfs_skip_summary_info(nilfs, &bh, &offset, sizeof(__le64), 365 nnodeblk); 366 if (unlikely(!bh)) 367 goto out; 368 } 369 err = 0; 370 out: 371 brelse(bh); /* brelse(NULL) is just ignored */ 372 return err; 373 } 374 375 static void dispose_recovery_list(struct list_head *head) 376 { 377 while (!list_empty(head)) { 378 struct nilfs_recovery_block *rb; 379 380 rb = list_first_entry(head, struct nilfs_recovery_block, list); 381 list_del(&rb->list); 382 kfree(rb); 383 } 384 } 385 386 struct nilfs_segment_entry { 387 struct list_head list; 388 __u64 segnum; 389 }; 390 391 static int nilfs_segment_list_add(struct list_head *head, __u64 segnum) 392 { 393 struct nilfs_segment_entry *ent = kmalloc(sizeof(*ent), GFP_NOFS); 394 395 if (unlikely(!ent)) 396 return -ENOMEM; 397 398 ent->segnum = segnum; 399 INIT_LIST_HEAD(&ent->list); 400 list_add_tail(&ent->list, head); 401 return 0; 402 } 403 404 void nilfs_dispose_segment_list(struct list_head *head) 405 { 406 while (!list_empty(head)) { 407 struct nilfs_segment_entry *ent; 408 409 ent = list_first_entry(head, struct nilfs_segment_entry, list); 410 list_del(&ent->list); 411 kfree(ent); 412 } 413 } 414 415 static int nilfs_prepare_segment_for_recovery(struct the_nilfs *nilfs, 416 struct super_block *sb, 417 struct nilfs_recovery_info *ri) 418 { 419 struct list_head *head = &ri->ri_used_segments; 420 struct nilfs_segment_entry *ent, *n; 421 struct inode *sufile = nilfs->ns_sufile; 422 __u64 segnum[4]; 423 int err; 424 int i; 425 426 segnum[0] = nilfs->ns_segnum; 427 segnum[1] = nilfs->ns_nextnum; 428 segnum[2] = ri->ri_segnum; 429 segnum[3] = ri->ri_nextnum; 430 431 /* 432 * Releasing the next segment of the latest super root. 433 * The next segment is invalidated by this recovery. 434 */ 435 err = nilfs_sufile_free(sufile, segnum[1]); 436 if (unlikely(err)) 437 goto failed; 438 439 for (i = 1; i < 4; i++) { 440 err = nilfs_segment_list_add(head, segnum[i]); 441 if (unlikely(err)) 442 goto failed; 443 } 444 445 /* 446 * Collecting segments written after the latest super root. 447 * These are marked dirty to avoid being reallocated in the next write. 448 */ 449 list_for_each_entry_safe(ent, n, head, list) { 450 if (ent->segnum != segnum[0]) { 451 err = nilfs_sufile_scrap(sufile, ent->segnum); 452 if (unlikely(err)) 453 goto failed; 454 } 455 list_del(&ent->list); 456 kfree(ent); 457 } 458 459 /* Allocate new segments for recovery */ 460 err = nilfs_sufile_alloc(sufile, &segnum[0]); 461 if (unlikely(err)) 462 goto failed; 463 464 nilfs->ns_pseg_offset = 0; 465 nilfs->ns_seg_seq = ri->ri_seq + 2; 466 nilfs->ns_nextnum = nilfs->ns_segnum = segnum[0]; 467 468 failed: 469 /* No need to recover sufile because it will be destroyed on error */ 470 return err; 471 } 472 473 static int nilfs_recovery_copy_block(struct the_nilfs *nilfs, 474 struct nilfs_recovery_block *rb, 475 struct page *page) 476 { 477 struct buffer_head *bh_org; 478 void *kaddr; 479 480 bh_org = __bread(nilfs->ns_bdev, rb->blocknr, nilfs->ns_blocksize); 481 if (unlikely(!bh_org)) 482 return -EIO; 483 484 kaddr = kmap_atomic(page); 485 memcpy(kaddr + bh_offset(bh_org), bh_org->b_data, bh_org->b_size); 486 kunmap_atomic(kaddr); 487 brelse(bh_org); 488 return 0; 489 } 490 491 static int nilfs_recover_dsync_blocks(struct the_nilfs *nilfs, 492 struct super_block *sb, 493 struct nilfs_root *root, 494 struct list_head *head, 495 unsigned long *nr_salvaged_blocks) 496 { 497 struct inode *inode; 498 struct nilfs_recovery_block *rb, *n; 499 unsigned int blocksize = nilfs->ns_blocksize; 500 struct page *page; 501 loff_t pos; 502 int err = 0, err2 = 0; 503 504 list_for_each_entry_safe(rb, n, head, list) { 505 inode = nilfs_iget(sb, root, rb->ino); 506 if (IS_ERR(inode)) { 507 err = PTR_ERR(inode); 508 inode = NULL; 509 goto failed_inode; 510 } 511 512 pos = rb->blkoff << inode->i_blkbits; 513 err = block_write_begin(inode->i_mapping, pos, blocksize, 514 0, &page, nilfs_get_block); 515 if (unlikely(err)) { 516 loff_t isize = inode->i_size; 517 518 if (pos + blocksize > isize) 519 nilfs_write_failed(inode->i_mapping, 520 pos + blocksize); 521 goto failed_inode; 522 } 523 524 err = nilfs_recovery_copy_block(nilfs, rb, page); 525 if (unlikely(err)) 526 goto failed_page; 527 528 err = nilfs_set_file_dirty(inode, 1); 529 if (unlikely(err)) 530 goto failed_page; 531 532 block_write_end(NULL, inode->i_mapping, pos, blocksize, 533 blocksize, page, NULL); 534 535 unlock_page(page); 536 put_page(page); 537 538 (*nr_salvaged_blocks)++; 539 goto next; 540 541 failed_page: 542 unlock_page(page); 543 put_page(page); 544 545 failed_inode: 546 nilfs_warn(sb, 547 "error %d recovering data block (ino=%lu, block-offset=%llu)", 548 err, (unsigned long)rb->ino, 549 (unsigned long long)rb->blkoff); 550 if (!err2) 551 err2 = err; 552 next: 553 iput(inode); /* iput(NULL) is just ignored */ 554 list_del_init(&rb->list); 555 kfree(rb); 556 } 557 return err2; 558 } 559 560 /** 561 * nilfs_do_roll_forward - salvage logical segments newer than the latest 562 * checkpoint 563 * @nilfs: nilfs object 564 * @sb: super block instance 565 * @ri: pointer to a nilfs_recovery_info 566 */ 567 static int nilfs_do_roll_forward(struct the_nilfs *nilfs, 568 struct super_block *sb, 569 struct nilfs_root *root, 570 struct nilfs_recovery_info *ri) 571 { 572 struct buffer_head *bh_sum = NULL; 573 struct nilfs_segment_summary *sum = NULL; 574 sector_t pseg_start; 575 sector_t seg_start, seg_end; /* Starting/ending DBN of full segment */ 576 unsigned long nsalvaged_blocks = 0; 577 unsigned int flags; 578 u64 seg_seq; 579 __u64 segnum, nextnum = 0; 580 int empty_seg = 0; 581 int err = 0, ret; 582 LIST_HEAD(dsync_blocks); /* list of data blocks to be recovered */ 583 enum { 584 RF_INIT_ST, 585 RF_DSYNC_ST, /* scanning data-sync segments */ 586 }; 587 int state = RF_INIT_ST; 588 589 pseg_start = ri->ri_lsegs_start; 590 seg_seq = ri->ri_lsegs_start_seq; 591 segnum = nilfs_get_segnum_of_block(nilfs, pseg_start); 592 nilfs_get_segment_range(nilfs, segnum, &seg_start, &seg_end); 593 594 while (segnum != ri->ri_segnum || pseg_start <= ri->ri_pseg_start) { 595 brelse(bh_sum); 596 bh_sum = nilfs_read_log_header(nilfs, pseg_start, &sum); 597 if (!bh_sum) { 598 err = -EIO; 599 goto failed; 600 } 601 602 ret = nilfs_validate_log(nilfs, seg_seq, bh_sum, sum); 603 if (ret) { 604 if (ret == NILFS_SEG_FAIL_IO) { 605 err = -EIO; 606 goto failed; 607 } 608 goto strayed; 609 } 610 611 flags = le16_to_cpu(sum->ss_flags); 612 if (flags & NILFS_SS_SR) 613 goto confused; 614 615 /* Found a valid partial segment; do recovery actions */ 616 nextnum = nilfs_get_segnum_of_block(nilfs, 617 le64_to_cpu(sum->ss_next)); 618 empty_seg = 0; 619 nilfs->ns_ctime = le64_to_cpu(sum->ss_create); 620 if (!(flags & NILFS_SS_GC)) 621 nilfs->ns_nongc_ctime = nilfs->ns_ctime; 622 623 switch (state) { 624 case RF_INIT_ST: 625 if (!(flags & NILFS_SS_LOGBGN) || 626 !(flags & NILFS_SS_SYNDT)) 627 goto try_next_pseg; 628 state = RF_DSYNC_ST; 629 fallthrough; 630 case RF_DSYNC_ST: 631 if (!(flags & NILFS_SS_SYNDT)) 632 goto confused; 633 634 err = nilfs_scan_dsync_log(nilfs, pseg_start, sum, 635 &dsync_blocks); 636 if (unlikely(err)) 637 goto failed; 638 if (flags & NILFS_SS_LOGEND) { 639 err = nilfs_recover_dsync_blocks( 640 nilfs, sb, root, &dsync_blocks, 641 &nsalvaged_blocks); 642 if (unlikely(err)) 643 goto failed; 644 state = RF_INIT_ST; 645 } 646 break; /* Fall through to try_next_pseg */ 647 } 648 649 try_next_pseg: 650 if (pseg_start == ri->ri_lsegs_end) 651 break; 652 pseg_start += le32_to_cpu(sum->ss_nblocks); 653 if (pseg_start < seg_end) 654 continue; 655 goto feed_segment; 656 657 strayed: 658 if (pseg_start == ri->ri_lsegs_end) 659 break; 660 661 feed_segment: 662 /* Looking to the next full segment */ 663 if (empty_seg++) 664 break; 665 seg_seq++; 666 segnum = nextnum; 667 nilfs_get_segment_range(nilfs, segnum, &seg_start, &seg_end); 668 pseg_start = seg_start; 669 } 670 671 if (nsalvaged_blocks) { 672 nilfs_info(sb, "salvaged %lu blocks", nsalvaged_blocks); 673 ri->ri_need_recovery = NILFS_RECOVERY_ROLLFORWARD_DONE; 674 } 675 out: 676 brelse(bh_sum); 677 dispose_recovery_list(&dsync_blocks); 678 return err; 679 680 confused: 681 err = -EINVAL; 682 failed: 683 nilfs_err(sb, 684 "error %d roll-forwarding partial segment at blocknr = %llu", 685 err, (unsigned long long)pseg_start); 686 goto out; 687 } 688 689 static void nilfs_finish_roll_forward(struct the_nilfs *nilfs, 690 struct nilfs_recovery_info *ri) 691 { 692 struct buffer_head *bh; 693 int err; 694 695 if (nilfs_get_segnum_of_block(nilfs, ri->ri_lsegs_start) != 696 nilfs_get_segnum_of_block(nilfs, ri->ri_super_root)) 697 return; 698 699 bh = __getblk(nilfs->ns_bdev, ri->ri_lsegs_start, nilfs->ns_blocksize); 700 BUG_ON(!bh); 701 memset(bh->b_data, 0, bh->b_size); 702 set_buffer_dirty(bh); 703 err = sync_dirty_buffer(bh); 704 if (unlikely(err)) 705 nilfs_warn(nilfs->ns_sb, 706 "buffer sync write failed during post-cleaning of recovery."); 707 brelse(bh); 708 } 709 710 /** 711 * nilfs_salvage_orphan_logs - salvage logs written after the latest checkpoint 712 * @nilfs: nilfs object 713 * @sb: super block instance 714 * @ri: pointer to a nilfs_recovery_info struct to store search results. 715 * 716 * Return Value: On success, 0 is returned. On error, one of the following 717 * negative error code is returned. 718 * 719 * %-EINVAL - Inconsistent filesystem state. 720 * 721 * %-EIO - I/O error 722 * 723 * %-ENOSPC - No space left on device (only in a panic state). 724 * 725 * %-ERESTARTSYS - Interrupted. 726 * 727 * %-ENOMEM - Insufficient memory available. 728 */ 729 int nilfs_salvage_orphan_logs(struct the_nilfs *nilfs, 730 struct super_block *sb, 731 struct nilfs_recovery_info *ri) 732 { 733 struct nilfs_root *root; 734 int err; 735 736 if (ri->ri_lsegs_start == 0 || ri->ri_lsegs_end == 0) 737 return 0; 738 739 err = nilfs_attach_checkpoint(sb, ri->ri_cno, true, &root); 740 if (unlikely(err)) { 741 nilfs_err(sb, "error %d loading the latest checkpoint", err); 742 return err; 743 } 744 745 err = nilfs_do_roll_forward(nilfs, sb, root, ri); 746 if (unlikely(err)) 747 goto failed; 748 749 if (ri->ri_need_recovery == NILFS_RECOVERY_ROLLFORWARD_DONE) { 750 err = nilfs_prepare_segment_for_recovery(nilfs, sb, ri); 751 if (unlikely(err)) { 752 nilfs_err(sb, "error %d preparing segment for recovery", 753 err); 754 goto failed; 755 } 756 757 err = nilfs_attach_log_writer(sb, root); 758 if (unlikely(err)) 759 goto failed; 760 761 set_nilfs_discontinued(nilfs); 762 err = nilfs_construct_segment(sb); 763 nilfs_detach_log_writer(sb); 764 765 if (unlikely(err)) { 766 nilfs_err(sb, "error %d writing segment for recovery", 767 err); 768 goto failed; 769 } 770 771 nilfs_finish_roll_forward(nilfs, ri); 772 } 773 774 failed: 775 nilfs_put_root(root); 776 return err; 777 } 778 779 /** 780 * nilfs_search_super_root - search the latest valid super root 781 * @nilfs: the_nilfs 782 * @ri: pointer to a nilfs_recovery_info struct to store search results. 783 * 784 * nilfs_search_super_root() looks for the latest super-root from a partial 785 * segment pointed by the superblock. It sets up struct the_nilfs through 786 * this search. It fills nilfs_recovery_info (ri) required for recovery. 787 * 788 * Return Value: On success, 0 is returned. On error, one of the following 789 * negative error code is returned. 790 * 791 * %-EINVAL - No valid segment found 792 * 793 * %-EIO - I/O error 794 * 795 * %-ENOMEM - Insufficient memory available. 796 */ 797 int nilfs_search_super_root(struct the_nilfs *nilfs, 798 struct nilfs_recovery_info *ri) 799 { 800 struct buffer_head *bh_sum = NULL; 801 struct nilfs_segment_summary *sum = NULL; 802 sector_t pseg_start, pseg_end, sr_pseg_start = 0; 803 sector_t seg_start, seg_end; /* range of full segment (block number) */ 804 sector_t b, end; 805 unsigned long nblocks; 806 unsigned int flags; 807 u64 seg_seq; 808 __u64 segnum, nextnum = 0; 809 __u64 cno; 810 LIST_HEAD(segments); 811 int empty_seg = 0, scan_newer = 0; 812 int ret; 813 814 pseg_start = nilfs->ns_last_pseg; 815 seg_seq = nilfs->ns_last_seq; 816 cno = nilfs->ns_last_cno; 817 segnum = nilfs_get_segnum_of_block(nilfs, pseg_start); 818 819 /* Calculate range of segment */ 820 nilfs_get_segment_range(nilfs, segnum, &seg_start, &seg_end); 821 822 /* Read ahead segment */ 823 b = seg_start; 824 while (b <= seg_end) 825 __breadahead(nilfs->ns_bdev, b++, nilfs->ns_blocksize); 826 827 for (;;) { 828 brelse(bh_sum); 829 ret = NILFS_SEG_FAIL_IO; 830 bh_sum = nilfs_read_log_header(nilfs, pseg_start, &sum); 831 if (!bh_sum) 832 goto failed; 833 834 ret = nilfs_validate_log(nilfs, seg_seq, bh_sum, sum); 835 if (ret) { 836 if (ret == NILFS_SEG_FAIL_IO) 837 goto failed; 838 goto strayed; 839 } 840 841 nblocks = le32_to_cpu(sum->ss_nblocks); 842 pseg_end = pseg_start + nblocks - 1; 843 if (unlikely(pseg_end > seg_end)) { 844 ret = NILFS_SEG_FAIL_CONSISTENCY; 845 goto strayed; 846 } 847 848 /* A valid partial segment */ 849 ri->ri_pseg_start = pseg_start; 850 ri->ri_seq = seg_seq; 851 ri->ri_segnum = segnum; 852 nextnum = nilfs_get_segnum_of_block(nilfs, 853 le64_to_cpu(sum->ss_next)); 854 ri->ri_nextnum = nextnum; 855 empty_seg = 0; 856 857 flags = le16_to_cpu(sum->ss_flags); 858 if (!(flags & NILFS_SS_SR) && !scan_newer) { 859 /* 860 * This will never happen because a superblock 861 * (last_segment) always points to a pseg with 862 * a super root. 863 */ 864 ret = NILFS_SEG_FAIL_CONSISTENCY; 865 goto failed; 866 } 867 868 if (pseg_start == seg_start) { 869 nilfs_get_segment_range(nilfs, nextnum, &b, &end); 870 while (b <= end) 871 __breadahead(nilfs->ns_bdev, b++, 872 nilfs->ns_blocksize); 873 } 874 if (!(flags & NILFS_SS_SR)) { 875 if (!ri->ri_lsegs_start && (flags & NILFS_SS_LOGBGN)) { 876 ri->ri_lsegs_start = pseg_start; 877 ri->ri_lsegs_start_seq = seg_seq; 878 } 879 if (flags & NILFS_SS_LOGEND) 880 ri->ri_lsegs_end = pseg_start; 881 goto try_next_pseg; 882 } 883 884 /* A valid super root was found. */ 885 ri->ri_cno = cno++; 886 ri->ri_super_root = pseg_end; 887 ri->ri_lsegs_start = ri->ri_lsegs_end = 0; 888 889 nilfs_dispose_segment_list(&segments); 890 sr_pseg_start = pseg_start; 891 nilfs->ns_pseg_offset = pseg_start + nblocks - seg_start; 892 nilfs->ns_seg_seq = seg_seq; 893 nilfs->ns_segnum = segnum; 894 nilfs->ns_cno = cno; /* nilfs->ns_cno = ri->ri_cno + 1 */ 895 nilfs->ns_ctime = le64_to_cpu(sum->ss_create); 896 nilfs->ns_nextnum = nextnum; 897 898 if (scan_newer) 899 ri->ri_need_recovery = NILFS_RECOVERY_SR_UPDATED; 900 else { 901 if (nilfs->ns_mount_state & NILFS_VALID_FS) 902 goto super_root_found; 903 scan_newer = 1; 904 } 905 906 try_next_pseg: 907 /* Standing on a course, or met an inconsistent state */ 908 pseg_start += nblocks; 909 if (pseg_start < seg_end) 910 continue; 911 goto feed_segment; 912 913 strayed: 914 /* Off the trail */ 915 if (!scan_newer) 916 /* 917 * This can happen if a checkpoint was written without 918 * barriers, or as a result of an I/O failure. 919 */ 920 goto failed; 921 922 feed_segment: 923 /* Looking to the next full segment */ 924 if (empty_seg++) 925 goto super_root_found; /* found a valid super root */ 926 927 ret = nilfs_segment_list_add(&segments, segnum); 928 if (unlikely(ret)) 929 goto failed; 930 931 seg_seq++; 932 segnum = nextnum; 933 nilfs_get_segment_range(nilfs, segnum, &seg_start, &seg_end); 934 pseg_start = seg_start; 935 } 936 937 super_root_found: 938 /* Updating pointers relating to the latest checkpoint */ 939 brelse(bh_sum); 940 list_splice_tail(&segments, &ri->ri_used_segments); 941 nilfs->ns_last_pseg = sr_pseg_start; 942 nilfs->ns_last_seq = nilfs->ns_seg_seq; 943 nilfs->ns_last_cno = ri->ri_cno; 944 return 0; 945 946 failed: 947 brelse(bh_sum); 948 nilfs_dispose_segment_list(&segments); 949 return ret < 0 ? ret : nilfs_warn_segment_error(nilfs->ns_sb, ret); 950 } 951