1 /* 2 * recovery.c - NILFS recovery logic 3 * 4 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation. 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to the Free Software 18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 19 * 20 * Written by Ryusuke Konishi <ryusuke@osrg.net> 21 */ 22 23 #include <linux/buffer_head.h> 24 #include <linux/blkdev.h> 25 #include <linux/swap.h> 26 #include <linux/slab.h> 27 #include <linux/crc32.h> 28 #include "nilfs.h" 29 #include "segment.h" 30 #include "sufile.h" 31 #include "page.h" 32 #include "segbuf.h" 33 34 /* 35 * Segment check result 36 */ 37 enum { 38 NILFS_SEG_VALID, 39 NILFS_SEG_NO_SUPER_ROOT, 40 NILFS_SEG_FAIL_IO, 41 NILFS_SEG_FAIL_MAGIC, 42 NILFS_SEG_FAIL_SEQ, 43 NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT, 44 NILFS_SEG_FAIL_CHECKSUM_FULL, 45 NILFS_SEG_FAIL_CONSISTENCY, 46 }; 47 48 /* work structure for recovery */ 49 struct nilfs_recovery_block { 50 ino_t ino; /* Inode number of the file that this block 51 belongs to */ 52 sector_t blocknr; /* block number */ 53 __u64 vblocknr; /* virtual block number */ 54 unsigned long blkoff; /* File offset of the data block (per block) */ 55 struct list_head list; 56 }; 57 58 59 static int nilfs_warn_segment_error(int err) 60 { 61 switch (err) { 62 case NILFS_SEG_FAIL_IO: 63 printk(KERN_WARNING 64 "NILFS warning: I/O error on loading last segment\n"); 65 return -EIO; 66 case NILFS_SEG_FAIL_MAGIC: 67 printk(KERN_WARNING 68 "NILFS warning: Segment magic number invalid\n"); 69 break; 70 case NILFS_SEG_FAIL_SEQ: 71 printk(KERN_WARNING 72 "NILFS warning: Sequence number mismatch\n"); 73 break; 74 case NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT: 75 printk(KERN_WARNING 76 "NILFS warning: Checksum error in super root\n"); 77 break; 78 case NILFS_SEG_FAIL_CHECKSUM_FULL: 79 printk(KERN_WARNING 80 "NILFS warning: Checksum error in segment payload\n"); 81 break; 82 case NILFS_SEG_FAIL_CONSISTENCY: 83 printk(KERN_WARNING 84 "NILFS warning: Inconsistent segment\n"); 85 break; 86 case NILFS_SEG_NO_SUPER_ROOT: 87 printk(KERN_WARNING 88 "NILFS warning: No super root in the last segment\n"); 89 break; 90 } 91 return -EINVAL; 92 } 93 94 /** 95 * nilfs_compute_checksum - compute checksum of blocks continuously 96 * @nilfs: nilfs object 97 * @bhs: buffer head of start block 98 * @sum: place to store result 99 * @offset: offset bytes in the first block 100 * @check_bytes: number of bytes to be checked 101 * @start: DBN of start block 102 * @nblock: number of blocks to be checked 103 */ 104 static int nilfs_compute_checksum(struct the_nilfs *nilfs, 105 struct buffer_head *bhs, u32 *sum, 106 unsigned long offset, u64 check_bytes, 107 sector_t start, unsigned long nblock) 108 { 109 unsigned int blocksize = nilfs->ns_blocksize; 110 unsigned long size; 111 u32 crc; 112 113 BUG_ON(offset >= blocksize); 114 check_bytes -= offset; 115 size = min_t(u64, check_bytes, blocksize - offset); 116 crc = crc32_le(nilfs->ns_crc_seed, 117 (unsigned char *)bhs->b_data + offset, size); 118 if (--nblock > 0) { 119 do { 120 struct buffer_head *bh; 121 122 bh = __bread(nilfs->ns_bdev, ++start, blocksize); 123 if (!bh) 124 return -EIO; 125 check_bytes -= size; 126 size = min_t(u64, check_bytes, blocksize); 127 crc = crc32_le(crc, bh->b_data, size); 128 brelse(bh); 129 } while (--nblock > 0); 130 } 131 *sum = crc; 132 return 0; 133 } 134 135 /** 136 * nilfs_read_super_root_block - read super root block 137 * @nilfs: nilfs object 138 * @sr_block: disk block number of the super root block 139 * @pbh: address of a buffer_head pointer to return super root buffer 140 * @check: CRC check flag 141 */ 142 int nilfs_read_super_root_block(struct the_nilfs *nilfs, sector_t sr_block, 143 struct buffer_head **pbh, int check) 144 { 145 struct buffer_head *bh_sr; 146 struct nilfs_super_root *sr; 147 u32 crc; 148 int ret; 149 150 *pbh = NULL; 151 bh_sr = __bread(nilfs->ns_bdev, sr_block, nilfs->ns_blocksize); 152 if (unlikely(!bh_sr)) { 153 ret = NILFS_SEG_FAIL_IO; 154 goto failed; 155 } 156 157 sr = (struct nilfs_super_root *)bh_sr->b_data; 158 if (check) { 159 unsigned bytes = le16_to_cpu(sr->sr_bytes); 160 161 if (bytes == 0 || bytes > nilfs->ns_blocksize) { 162 ret = NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT; 163 goto failed_bh; 164 } 165 if (nilfs_compute_checksum( 166 nilfs, bh_sr, &crc, sizeof(sr->sr_sum), bytes, 167 sr_block, 1)) { 168 ret = NILFS_SEG_FAIL_IO; 169 goto failed_bh; 170 } 171 if (crc != le32_to_cpu(sr->sr_sum)) { 172 ret = NILFS_SEG_FAIL_CHECKSUM_SUPER_ROOT; 173 goto failed_bh; 174 } 175 } 176 *pbh = bh_sr; 177 return 0; 178 179 failed_bh: 180 brelse(bh_sr); 181 182 failed: 183 return nilfs_warn_segment_error(ret); 184 } 185 186 /** 187 * nilfs_read_log_header - read summary header of the specified log 188 * @nilfs: nilfs object 189 * @start_blocknr: start block number of the log 190 * @sum: pointer to return segment summary structure 191 */ 192 static struct buffer_head * 193 nilfs_read_log_header(struct the_nilfs *nilfs, sector_t start_blocknr, 194 struct nilfs_segment_summary **sum) 195 { 196 struct buffer_head *bh_sum; 197 198 bh_sum = __bread(nilfs->ns_bdev, start_blocknr, nilfs->ns_blocksize); 199 if (bh_sum) 200 *sum = (struct nilfs_segment_summary *)bh_sum->b_data; 201 return bh_sum; 202 } 203 204 /** 205 * nilfs_validate_log - verify consistency of log 206 * @nilfs: nilfs object 207 * @seg_seq: sequence number of segment 208 * @bh_sum: buffer head of summary block 209 * @sum: segment summary struct 210 */ 211 static int nilfs_validate_log(struct the_nilfs *nilfs, u64 seg_seq, 212 struct buffer_head *bh_sum, 213 struct nilfs_segment_summary *sum) 214 { 215 unsigned long nblock; 216 u32 crc; 217 int ret; 218 219 ret = NILFS_SEG_FAIL_MAGIC; 220 if (le32_to_cpu(sum->ss_magic) != NILFS_SEGSUM_MAGIC) 221 goto out; 222 223 ret = NILFS_SEG_FAIL_SEQ; 224 if (le64_to_cpu(sum->ss_seq) != seg_seq) 225 goto out; 226 227 nblock = le32_to_cpu(sum->ss_nblocks); 228 ret = NILFS_SEG_FAIL_CONSISTENCY; 229 if (unlikely(nblock == 0 || nblock > nilfs->ns_blocks_per_segment)) 230 /* This limits the number of blocks read in the CRC check */ 231 goto out; 232 233 ret = NILFS_SEG_FAIL_IO; 234 if (nilfs_compute_checksum(nilfs, bh_sum, &crc, sizeof(sum->ss_datasum), 235 ((u64)nblock << nilfs->ns_blocksize_bits), 236 bh_sum->b_blocknr, nblock)) 237 goto out; 238 239 ret = NILFS_SEG_FAIL_CHECKSUM_FULL; 240 if (crc != le32_to_cpu(sum->ss_datasum)) 241 goto out; 242 ret = 0; 243 out: 244 return ret; 245 } 246 247 /** 248 * nilfs_read_summary_info - read an item on summary blocks of a log 249 * @nilfs: nilfs object 250 * @pbh: the current buffer head on summary blocks [in, out] 251 * @offset: the current byte offset on summary blocks [in, out] 252 * @bytes: byte size of the item to be read 253 */ 254 static void *nilfs_read_summary_info(struct the_nilfs *nilfs, 255 struct buffer_head **pbh, 256 unsigned int *offset, unsigned int bytes) 257 { 258 void *ptr; 259 sector_t blocknr; 260 261 BUG_ON((*pbh)->b_size < *offset); 262 if (bytes > (*pbh)->b_size - *offset) { 263 blocknr = (*pbh)->b_blocknr; 264 brelse(*pbh); 265 *pbh = __bread(nilfs->ns_bdev, blocknr + 1, 266 nilfs->ns_blocksize); 267 if (unlikely(!*pbh)) 268 return NULL; 269 *offset = 0; 270 } 271 ptr = (*pbh)->b_data + *offset; 272 *offset += bytes; 273 return ptr; 274 } 275 276 /** 277 * nilfs_skip_summary_info - skip items on summary blocks of a log 278 * @nilfs: nilfs object 279 * @pbh: the current buffer head on summary blocks [in, out] 280 * @offset: the current byte offset on summary blocks [in, out] 281 * @bytes: byte size of the item to be skipped 282 * @count: number of items to be skipped 283 */ 284 static void nilfs_skip_summary_info(struct the_nilfs *nilfs, 285 struct buffer_head **pbh, 286 unsigned int *offset, unsigned int bytes, 287 unsigned long count) 288 { 289 unsigned int rest_item_in_current_block 290 = ((*pbh)->b_size - *offset) / bytes; 291 292 if (count <= rest_item_in_current_block) { 293 *offset += bytes * count; 294 } else { 295 sector_t blocknr = (*pbh)->b_blocknr; 296 unsigned int nitem_per_block = (*pbh)->b_size / bytes; 297 unsigned int bcnt; 298 299 count -= rest_item_in_current_block; 300 bcnt = DIV_ROUND_UP(count, nitem_per_block); 301 *offset = bytes * (count - (bcnt - 1) * nitem_per_block); 302 303 brelse(*pbh); 304 *pbh = __bread(nilfs->ns_bdev, blocknr + bcnt, 305 nilfs->ns_blocksize); 306 } 307 } 308 309 /** 310 * nilfs_scan_dsync_log - get block information of a log written for data sync 311 * @nilfs: nilfs object 312 * @start_blocknr: start block number of the log 313 * @sum: log summary information 314 * @head: list head to add nilfs_recovery_block struct 315 */ 316 static int nilfs_scan_dsync_log(struct the_nilfs *nilfs, sector_t start_blocknr, 317 struct nilfs_segment_summary *sum, 318 struct list_head *head) 319 { 320 struct buffer_head *bh; 321 unsigned int offset; 322 u32 nfinfo, sumbytes; 323 sector_t blocknr; 324 ino_t ino; 325 int err = -EIO; 326 327 nfinfo = le32_to_cpu(sum->ss_nfinfo); 328 if (!nfinfo) 329 return 0; 330 331 sumbytes = le32_to_cpu(sum->ss_sumbytes); 332 blocknr = start_blocknr + DIV_ROUND_UP(sumbytes, nilfs->ns_blocksize); 333 bh = __bread(nilfs->ns_bdev, start_blocknr, nilfs->ns_blocksize); 334 if (unlikely(!bh)) 335 goto out; 336 337 offset = le16_to_cpu(sum->ss_bytes); 338 for (;;) { 339 unsigned long nblocks, ndatablk, nnodeblk; 340 struct nilfs_finfo *finfo; 341 342 finfo = nilfs_read_summary_info(nilfs, &bh, &offset, 343 sizeof(*finfo)); 344 if (unlikely(!finfo)) 345 goto out; 346 347 ino = le64_to_cpu(finfo->fi_ino); 348 nblocks = le32_to_cpu(finfo->fi_nblocks); 349 ndatablk = le32_to_cpu(finfo->fi_ndatablk); 350 nnodeblk = nblocks - ndatablk; 351 352 while (ndatablk-- > 0) { 353 struct nilfs_recovery_block *rb; 354 struct nilfs_binfo_v *binfo; 355 356 binfo = nilfs_read_summary_info(nilfs, &bh, &offset, 357 sizeof(*binfo)); 358 if (unlikely(!binfo)) 359 goto out; 360 361 rb = kmalloc(sizeof(*rb), GFP_NOFS); 362 if (unlikely(!rb)) { 363 err = -ENOMEM; 364 goto out; 365 } 366 rb->ino = ino; 367 rb->blocknr = blocknr++; 368 rb->vblocknr = le64_to_cpu(binfo->bi_vblocknr); 369 rb->blkoff = le64_to_cpu(binfo->bi_blkoff); 370 /* INIT_LIST_HEAD(&rb->list); */ 371 list_add_tail(&rb->list, head); 372 } 373 if (--nfinfo == 0) 374 break; 375 blocknr += nnodeblk; /* always 0 for data sync logs */ 376 nilfs_skip_summary_info(nilfs, &bh, &offset, sizeof(__le64), 377 nnodeblk); 378 if (unlikely(!bh)) 379 goto out; 380 } 381 err = 0; 382 out: 383 brelse(bh); /* brelse(NULL) is just ignored */ 384 return err; 385 } 386 387 static void dispose_recovery_list(struct list_head *head) 388 { 389 while (!list_empty(head)) { 390 struct nilfs_recovery_block *rb; 391 392 rb = list_first_entry(head, struct nilfs_recovery_block, list); 393 list_del(&rb->list); 394 kfree(rb); 395 } 396 } 397 398 struct nilfs_segment_entry { 399 struct list_head list; 400 __u64 segnum; 401 }; 402 403 static int nilfs_segment_list_add(struct list_head *head, __u64 segnum) 404 { 405 struct nilfs_segment_entry *ent = kmalloc(sizeof(*ent), GFP_NOFS); 406 407 if (unlikely(!ent)) 408 return -ENOMEM; 409 410 ent->segnum = segnum; 411 INIT_LIST_HEAD(&ent->list); 412 list_add_tail(&ent->list, head); 413 return 0; 414 } 415 416 void nilfs_dispose_segment_list(struct list_head *head) 417 { 418 while (!list_empty(head)) { 419 struct nilfs_segment_entry *ent; 420 421 ent = list_first_entry(head, struct nilfs_segment_entry, list); 422 list_del(&ent->list); 423 kfree(ent); 424 } 425 } 426 427 static int nilfs_prepare_segment_for_recovery(struct the_nilfs *nilfs, 428 struct super_block *sb, 429 struct nilfs_recovery_info *ri) 430 { 431 struct list_head *head = &ri->ri_used_segments; 432 struct nilfs_segment_entry *ent, *n; 433 struct inode *sufile = nilfs->ns_sufile; 434 __u64 segnum[4]; 435 int err; 436 int i; 437 438 segnum[0] = nilfs->ns_segnum; 439 segnum[1] = nilfs->ns_nextnum; 440 segnum[2] = ri->ri_segnum; 441 segnum[3] = ri->ri_nextnum; 442 443 /* 444 * Releasing the next segment of the latest super root. 445 * The next segment is invalidated by this recovery. 446 */ 447 err = nilfs_sufile_free(sufile, segnum[1]); 448 if (unlikely(err)) 449 goto failed; 450 451 for (i = 1; i < 4; i++) { 452 err = nilfs_segment_list_add(head, segnum[i]); 453 if (unlikely(err)) 454 goto failed; 455 } 456 457 /* 458 * Collecting segments written after the latest super root. 459 * These are marked dirty to avoid being reallocated in the next write. 460 */ 461 list_for_each_entry_safe(ent, n, head, list) { 462 if (ent->segnum != segnum[0]) { 463 err = nilfs_sufile_scrap(sufile, ent->segnum); 464 if (unlikely(err)) 465 goto failed; 466 } 467 list_del(&ent->list); 468 kfree(ent); 469 } 470 471 /* Allocate new segments for recovery */ 472 err = nilfs_sufile_alloc(sufile, &segnum[0]); 473 if (unlikely(err)) 474 goto failed; 475 476 nilfs->ns_pseg_offset = 0; 477 nilfs->ns_seg_seq = ri->ri_seq + 2; 478 nilfs->ns_nextnum = nilfs->ns_segnum = segnum[0]; 479 480 failed: 481 /* No need to recover sufile because it will be destroyed on error */ 482 return err; 483 } 484 485 static int nilfs_recovery_copy_block(struct the_nilfs *nilfs, 486 struct nilfs_recovery_block *rb, 487 struct page *page) 488 { 489 struct buffer_head *bh_org; 490 void *kaddr; 491 492 bh_org = __bread(nilfs->ns_bdev, rb->blocknr, nilfs->ns_blocksize); 493 if (unlikely(!bh_org)) 494 return -EIO; 495 496 kaddr = kmap_atomic(page, KM_USER0); 497 memcpy(kaddr + bh_offset(bh_org), bh_org->b_data, bh_org->b_size); 498 kunmap_atomic(kaddr, KM_USER0); 499 brelse(bh_org); 500 return 0; 501 } 502 503 static int nilfs_recover_dsync_blocks(struct the_nilfs *nilfs, 504 struct super_block *sb, 505 struct nilfs_root *root, 506 struct list_head *head, 507 unsigned long *nr_salvaged_blocks) 508 { 509 struct inode *inode; 510 struct nilfs_recovery_block *rb, *n; 511 unsigned blocksize = nilfs->ns_blocksize; 512 struct page *page; 513 loff_t pos; 514 int err = 0, err2 = 0; 515 516 list_for_each_entry_safe(rb, n, head, list) { 517 inode = nilfs_iget(sb, root, rb->ino); 518 if (IS_ERR(inode)) { 519 err = PTR_ERR(inode); 520 inode = NULL; 521 goto failed_inode; 522 } 523 524 pos = rb->blkoff << inode->i_blkbits; 525 err = block_write_begin(inode->i_mapping, pos, blocksize, 526 0, &page, nilfs_get_block); 527 if (unlikely(err)) { 528 loff_t isize = inode->i_size; 529 if (pos + blocksize > isize) 530 vmtruncate(inode, isize); 531 goto failed_inode; 532 } 533 534 err = nilfs_recovery_copy_block(nilfs, rb, page); 535 if (unlikely(err)) 536 goto failed_page; 537 538 err = nilfs_set_file_dirty(inode, 1); 539 if (unlikely(err)) 540 goto failed_page; 541 542 block_write_end(NULL, inode->i_mapping, pos, blocksize, 543 blocksize, page, NULL); 544 545 unlock_page(page); 546 page_cache_release(page); 547 548 (*nr_salvaged_blocks)++; 549 goto next; 550 551 failed_page: 552 unlock_page(page); 553 page_cache_release(page); 554 555 failed_inode: 556 printk(KERN_WARNING 557 "NILFS warning: error recovering data block " 558 "(err=%d, ino=%lu, block-offset=%llu)\n", 559 err, (unsigned long)rb->ino, 560 (unsigned long long)rb->blkoff); 561 if (!err2) 562 err2 = err; 563 next: 564 iput(inode); /* iput(NULL) is just ignored */ 565 list_del_init(&rb->list); 566 kfree(rb); 567 } 568 return err2; 569 } 570 571 /** 572 * nilfs_do_roll_forward - salvage logical segments newer than the latest 573 * checkpoint 574 * @nilfs: nilfs object 575 * @sb: super block instance 576 * @ri: pointer to a nilfs_recovery_info 577 */ 578 static int nilfs_do_roll_forward(struct the_nilfs *nilfs, 579 struct super_block *sb, 580 struct nilfs_root *root, 581 struct nilfs_recovery_info *ri) 582 { 583 struct buffer_head *bh_sum = NULL; 584 struct nilfs_segment_summary *sum; 585 sector_t pseg_start; 586 sector_t seg_start, seg_end; /* Starting/ending DBN of full segment */ 587 unsigned long nsalvaged_blocks = 0; 588 unsigned int flags; 589 u64 seg_seq; 590 __u64 segnum, nextnum = 0; 591 int empty_seg = 0; 592 int err = 0, ret; 593 LIST_HEAD(dsync_blocks); /* list of data blocks to be recovered */ 594 enum { 595 RF_INIT_ST, 596 RF_DSYNC_ST, /* scanning data-sync segments */ 597 }; 598 int state = RF_INIT_ST; 599 600 pseg_start = ri->ri_lsegs_start; 601 seg_seq = ri->ri_lsegs_start_seq; 602 segnum = nilfs_get_segnum_of_block(nilfs, pseg_start); 603 nilfs_get_segment_range(nilfs, segnum, &seg_start, &seg_end); 604 605 while (segnum != ri->ri_segnum || pseg_start <= ri->ri_pseg_start) { 606 brelse(bh_sum); 607 bh_sum = nilfs_read_log_header(nilfs, pseg_start, &sum); 608 if (!bh_sum) { 609 err = -EIO; 610 goto failed; 611 } 612 613 ret = nilfs_validate_log(nilfs, seg_seq, bh_sum, sum); 614 if (ret) { 615 if (ret == NILFS_SEG_FAIL_IO) { 616 err = -EIO; 617 goto failed; 618 } 619 goto strayed; 620 } 621 622 flags = le16_to_cpu(sum->ss_flags); 623 if (flags & NILFS_SS_SR) 624 goto confused; 625 626 /* Found a valid partial segment; do recovery actions */ 627 nextnum = nilfs_get_segnum_of_block(nilfs, 628 le64_to_cpu(sum->ss_next)); 629 empty_seg = 0; 630 nilfs->ns_ctime = le64_to_cpu(sum->ss_create); 631 if (!(flags & NILFS_SS_GC)) 632 nilfs->ns_nongc_ctime = nilfs->ns_ctime; 633 634 switch (state) { 635 case RF_INIT_ST: 636 if (!(flags & NILFS_SS_LOGBGN) || 637 !(flags & NILFS_SS_SYNDT)) 638 goto try_next_pseg; 639 state = RF_DSYNC_ST; 640 /* Fall through */ 641 case RF_DSYNC_ST: 642 if (!(flags & NILFS_SS_SYNDT)) 643 goto confused; 644 645 err = nilfs_scan_dsync_log(nilfs, pseg_start, sum, 646 &dsync_blocks); 647 if (unlikely(err)) 648 goto failed; 649 if (flags & NILFS_SS_LOGEND) { 650 err = nilfs_recover_dsync_blocks( 651 nilfs, sb, root, &dsync_blocks, 652 &nsalvaged_blocks); 653 if (unlikely(err)) 654 goto failed; 655 state = RF_INIT_ST; 656 } 657 break; /* Fall through to try_next_pseg */ 658 } 659 660 try_next_pseg: 661 if (pseg_start == ri->ri_lsegs_end) 662 break; 663 pseg_start += le32_to_cpu(sum->ss_nblocks); 664 if (pseg_start < seg_end) 665 continue; 666 goto feed_segment; 667 668 strayed: 669 if (pseg_start == ri->ri_lsegs_end) 670 break; 671 672 feed_segment: 673 /* Looking to the next full segment */ 674 if (empty_seg++) 675 break; 676 seg_seq++; 677 segnum = nextnum; 678 nilfs_get_segment_range(nilfs, segnum, &seg_start, &seg_end); 679 pseg_start = seg_start; 680 } 681 682 if (nsalvaged_blocks) { 683 printk(KERN_INFO "NILFS (device %s): salvaged %lu blocks\n", 684 sb->s_id, nsalvaged_blocks); 685 ri->ri_need_recovery = NILFS_RECOVERY_ROLLFORWARD_DONE; 686 } 687 out: 688 brelse(bh_sum); 689 dispose_recovery_list(&dsync_blocks); 690 return err; 691 692 confused: 693 err = -EINVAL; 694 failed: 695 printk(KERN_ERR 696 "NILFS (device %s): Error roll-forwarding " 697 "(err=%d, pseg block=%llu). ", 698 sb->s_id, err, (unsigned long long)pseg_start); 699 goto out; 700 } 701 702 static void nilfs_finish_roll_forward(struct the_nilfs *nilfs, 703 struct nilfs_recovery_info *ri) 704 { 705 struct buffer_head *bh; 706 int err; 707 708 if (nilfs_get_segnum_of_block(nilfs, ri->ri_lsegs_start) != 709 nilfs_get_segnum_of_block(nilfs, ri->ri_super_root)) 710 return; 711 712 bh = __getblk(nilfs->ns_bdev, ri->ri_lsegs_start, nilfs->ns_blocksize); 713 BUG_ON(!bh); 714 memset(bh->b_data, 0, bh->b_size); 715 set_buffer_dirty(bh); 716 err = sync_dirty_buffer(bh); 717 if (unlikely(err)) 718 printk(KERN_WARNING 719 "NILFS warning: buffer sync write failed during " 720 "post-cleaning of recovery.\n"); 721 brelse(bh); 722 } 723 724 /** 725 * nilfs_salvage_orphan_logs - salvage logs written after the latest checkpoint 726 * @nilfs: nilfs object 727 * @sb: super block instance 728 * @ri: pointer to a nilfs_recovery_info struct to store search results. 729 * 730 * Return Value: On success, 0 is returned. On error, one of the following 731 * negative error code is returned. 732 * 733 * %-EINVAL - Inconsistent filesystem state. 734 * 735 * %-EIO - I/O error 736 * 737 * %-ENOSPC - No space left on device (only in a panic state). 738 * 739 * %-ERESTARTSYS - Interrupted. 740 * 741 * %-ENOMEM - Insufficient memory available. 742 */ 743 int nilfs_salvage_orphan_logs(struct the_nilfs *nilfs, 744 struct super_block *sb, 745 struct nilfs_recovery_info *ri) 746 { 747 struct nilfs_root *root; 748 int err; 749 750 if (ri->ri_lsegs_start == 0 || ri->ri_lsegs_end == 0) 751 return 0; 752 753 err = nilfs_attach_checkpoint(sb, ri->ri_cno, true, &root); 754 if (unlikely(err)) { 755 printk(KERN_ERR 756 "NILFS: error loading the latest checkpoint.\n"); 757 return err; 758 } 759 760 err = nilfs_do_roll_forward(nilfs, sb, root, ri); 761 if (unlikely(err)) 762 goto failed; 763 764 if (ri->ri_need_recovery == NILFS_RECOVERY_ROLLFORWARD_DONE) { 765 err = nilfs_prepare_segment_for_recovery(nilfs, sb, ri); 766 if (unlikely(err)) { 767 printk(KERN_ERR "NILFS: Error preparing segments for " 768 "recovery.\n"); 769 goto failed; 770 } 771 772 err = nilfs_attach_log_writer(sb, root); 773 if (unlikely(err)) 774 goto failed; 775 776 set_nilfs_discontinued(nilfs); 777 err = nilfs_construct_segment(sb); 778 nilfs_detach_log_writer(sb); 779 780 if (unlikely(err)) { 781 printk(KERN_ERR "NILFS: Oops! recovery failed. " 782 "(err=%d)\n", err); 783 goto failed; 784 } 785 786 nilfs_finish_roll_forward(nilfs, ri); 787 } 788 789 failed: 790 nilfs_put_root(root); 791 return err; 792 } 793 794 /** 795 * nilfs_search_super_root - search the latest valid super root 796 * @nilfs: the_nilfs 797 * @ri: pointer to a nilfs_recovery_info struct to store search results. 798 * 799 * nilfs_search_super_root() looks for the latest super-root from a partial 800 * segment pointed by the superblock. It sets up struct the_nilfs through 801 * this search. It fills nilfs_recovery_info (ri) required for recovery. 802 * 803 * Return Value: On success, 0 is returned. On error, one of the following 804 * negative error code is returned. 805 * 806 * %-EINVAL - No valid segment found 807 * 808 * %-EIO - I/O error 809 * 810 * %-ENOMEM - Insufficient memory available. 811 */ 812 int nilfs_search_super_root(struct the_nilfs *nilfs, 813 struct nilfs_recovery_info *ri) 814 { 815 struct buffer_head *bh_sum = NULL; 816 struct nilfs_segment_summary *sum; 817 sector_t pseg_start, pseg_end, sr_pseg_start = 0; 818 sector_t seg_start, seg_end; /* range of full segment (block number) */ 819 sector_t b, end; 820 unsigned long nblocks; 821 unsigned int flags; 822 u64 seg_seq; 823 __u64 segnum, nextnum = 0; 824 __u64 cno; 825 LIST_HEAD(segments); 826 int empty_seg = 0, scan_newer = 0; 827 int ret; 828 829 pseg_start = nilfs->ns_last_pseg; 830 seg_seq = nilfs->ns_last_seq; 831 cno = nilfs->ns_last_cno; 832 segnum = nilfs_get_segnum_of_block(nilfs, pseg_start); 833 834 /* Calculate range of segment */ 835 nilfs_get_segment_range(nilfs, segnum, &seg_start, &seg_end); 836 837 /* Read ahead segment */ 838 b = seg_start; 839 while (b <= seg_end) 840 __breadahead(nilfs->ns_bdev, b++, nilfs->ns_blocksize); 841 842 for (;;) { 843 brelse(bh_sum); 844 ret = NILFS_SEG_FAIL_IO; 845 bh_sum = nilfs_read_log_header(nilfs, pseg_start, &sum); 846 if (!bh_sum) 847 goto failed; 848 849 ret = nilfs_validate_log(nilfs, seg_seq, bh_sum, sum); 850 if (ret) { 851 if (ret == NILFS_SEG_FAIL_IO) 852 goto failed; 853 goto strayed; 854 } 855 856 nblocks = le32_to_cpu(sum->ss_nblocks); 857 pseg_end = pseg_start + nblocks - 1; 858 if (unlikely(pseg_end > seg_end)) { 859 ret = NILFS_SEG_FAIL_CONSISTENCY; 860 goto strayed; 861 } 862 863 /* A valid partial segment */ 864 ri->ri_pseg_start = pseg_start; 865 ri->ri_seq = seg_seq; 866 ri->ri_segnum = segnum; 867 nextnum = nilfs_get_segnum_of_block(nilfs, 868 le64_to_cpu(sum->ss_next)); 869 ri->ri_nextnum = nextnum; 870 empty_seg = 0; 871 872 flags = le16_to_cpu(sum->ss_flags); 873 if (!(flags & NILFS_SS_SR) && !scan_newer) { 874 /* This will never happen because a superblock 875 (last_segment) always points to a pseg 876 having a super root. */ 877 ret = NILFS_SEG_FAIL_CONSISTENCY; 878 goto failed; 879 } 880 881 if (pseg_start == seg_start) { 882 nilfs_get_segment_range(nilfs, nextnum, &b, &end); 883 while (b <= end) 884 __breadahead(nilfs->ns_bdev, b++, 885 nilfs->ns_blocksize); 886 } 887 if (!(flags & NILFS_SS_SR)) { 888 if (!ri->ri_lsegs_start && (flags & NILFS_SS_LOGBGN)) { 889 ri->ri_lsegs_start = pseg_start; 890 ri->ri_lsegs_start_seq = seg_seq; 891 } 892 if (flags & NILFS_SS_LOGEND) 893 ri->ri_lsegs_end = pseg_start; 894 goto try_next_pseg; 895 } 896 897 /* A valid super root was found. */ 898 ri->ri_cno = cno++; 899 ri->ri_super_root = pseg_end; 900 ri->ri_lsegs_start = ri->ri_lsegs_end = 0; 901 902 nilfs_dispose_segment_list(&segments); 903 sr_pseg_start = pseg_start; 904 nilfs->ns_pseg_offset = pseg_start + nblocks - seg_start; 905 nilfs->ns_seg_seq = seg_seq; 906 nilfs->ns_segnum = segnum; 907 nilfs->ns_cno = cno; /* nilfs->ns_cno = ri->ri_cno + 1 */ 908 nilfs->ns_ctime = le64_to_cpu(sum->ss_create); 909 nilfs->ns_nextnum = nextnum; 910 911 if (scan_newer) 912 ri->ri_need_recovery = NILFS_RECOVERY_SR_UPDATED; 913 else { 914 if (nilfs->ns_mount_state & NILFS_VALID_FS) 915 goto super_root_found; 916 scan_newer = 1; 917 } 918 919 try_next_pseg: 920 /* Standing on a course, or met an inconsistent state */ 921 pseg_start += nblocks; 922 if (pseg_start < seg_end) 923 continue; 924 goto feed_segment; 925 926 strayed: 927 /* Off the trail */ 928 if (!scan_newer) 929 /* 930 * This can happen if a checkpoint was written without 931 * barriers, or as a result of an I/O failure. 932 */ 933 goto failed; 934 935 feed_segment: 936 /* Looking to the next full segment */ 937 if (empty_seg++) 938 goto super_root_found; /* found a valid super root */ 939 940 ret = nilfs_segment_list_add(&segments, segnum); 941 if (unlikely(ret)) 942 goto failed; 943 944 seg_seq++; 945 segnum = nextnum; 946 nilfs_get_segment_range(nilfs, segnum, &seg_start, &seg_end); 947 pseg_start = seg_start; 948 } 949 950 super_root_found: 951 /* Updating pointers relating to the latest checkpoint */ 952 brelse(bh_sum); 953 list_splice_tail(&segments, &ri->ri_used_segments); 954 nilfs->ns_last_pseg = sr_pseg_start; 955 nilfs->ns_last_seq = nilfs->ns_seg_seq; 956 nilfs->ns_last_cno = ri->ri_cno; 957 return 0; 958 959 failed: 960 brelse(bh_sum); 961 nilfs_dispose_segment_list(&segments); 962 return (ret < 0) ? ret : nilfs_warn_segment_error(ret); 963 } 964