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 */ 37enum { 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 */ 49struct 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 59static 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 */ 104static 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 */ 142int 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 */ 192static struct buffer_head * 193nilfs_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 */ 211static 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; 243out: 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 */ 254static 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 */ 284static 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 */ 316static 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 387static void dispose_recovery_list(struct list_head *head) 388{ 389 while (!list_empty(head)) { 390 struct nilfs_recovery_block *rb 391 = list_entry(head->next, 392 struct nilfs_recovery_block, list); 393 list_del(&rb->list); 394 kfree(rb); 395 } 396} 397 398struct nilfs_segment_entry { 399 struct list_head list; 400 __u64 segnum; 401}; 402 403static 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 416void nilfs_dispose_segment_list(struct list_head *head) 417{ 418 while (!list_empty(head)) { 419 struct nilfs_segment_entry *ent 420 = list_entry(head->next, 421 struct nilfs_segment_entry, list); 422 list_del(&ent->list); 423 kfree(ent); 424 } 425} 426 427static int nilfs_prepare_segment_for_recovery(struct the_nilfs *nilfs, 428 struct nilfs_sb_info *sbi, 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 nilfs_attach_writer(nilfs, sbi); 444 /* 445 * Releasing the next segment of the latest super root. 446 * The next segment is invalidated by this recovery. 447 */ 448 err = nilfs_sufile_free(sufile, segnum[1]); 449 if (unlikely(err)) 450 goto failed; 451 452 for (i = 1; i < 4; i++) { 453 err = nilfs_segment_list_add(head, segnum[i]); 454 if (unlikely(err)) 455 goto failed; 456 } 457 458 /* 459 * Collecting segments written after the latest super root. 460 * These are marked dirty to avoid being reallocated in the next write. 461 */ 462 list_for_each_entry_safe(ent, n, head, list) { 463 if (ent->segnum != segnum[0]) { 464 err = nilfs_sufile_scrap(sufile, ent->segnum); 465 if (unlikely(err)) 466 goto failed; 467 } 468 list_del(&ent->list); 469 kfree(ent); 470 } 471 472 /* Allocate new segments for recovery */ 473 err = nilfs_sufile_alloc(sufile, &segnum[0]); 474 if (unlikely(err)) 475 goto failed; 476 477 nilfs->ns_pseg_offset = 0; 478 nilfs->ns_seg_seq = ri->ri_seq + 2; 479 nilfs->ns_nextnum = nilfs->ns_segnum = segnum[0]; 480 481 failed: 482 /* No need to recover sufile because it will be destroyed on error */ 483 nilfs_detach_writer(nilfs, sbi); 484 return err; 485} 486 487static int nilfs_recovery_copy_block(struct the_nilfs *nilfs, 488 struct nilfs_recovery_block *rb, 489 struct page *page) 490{ 491 struct buffer_head *bh_org; 492 void *kaddr; 493 494 bh_org = __bread(nilfs->ns_bdev, rb->blocknr, nilfs->ns_blocksize); 495 if (unlikely(!bh_org)) 496 return -EIO; 497 498 kaddr = kmap_atomic(page, KM_USER0); 499 memcpy(kaddr + bh_offset(bh_org), bh_org->b_data, bh_org->b_size); 500 kunmap_atomic(kaddr, KM_USER0); 501 brelse(bh_org); 502 return 0; 503} 504 505static int nilfs_recover_dsync_blocks(struct the_nilfs *nilfs, 506 struct nilfs_sb_info *sbi, 507 struct list_head *head, 508 unsigned long *nr_salvaged_blocks) 509{ 510 struct inode *inode; 511 struct nilfs_recovery_block *rb, *n; 512 unsigned blocksize = nilfs->ns_blocksize; 513 struct page *page; 514 loff_t pos; 515 int err = 0, err2 = 0; 516 517 list_for_each_entry_safe(rb, n, head, list) { 518 inode = nilfs_iget(sbi->s_super, rb->ino); 519 if (IS_ERR(inode)) { 520 err = PTR_ERR(inode); 521 inode = NULL; 522 goto failed_inode; 523 } 524 525 pos = rb->blkoff << inode->i_blkbits; 526 err = block_write_begin(inode->i_mapping, pos, blocksize, 527 0, &page, nilfs_get_block); 528 if (unlikely(err)) { 529 loff_t isize = inode->i_size; 530 if (pos + blocksize > isize) 531 vmtruncate(inode, isize); 532 goto failed_inode; 533 } 534 535 err = nilfs_recovery_copy_block(nilfs, rb, page); 536 if (unlikely(err)) 537 goto failed_page; 538 539 err = nilfs_set_file_dirty(sbi, inode, 1); 540 if (unlikely(err)) 541 goto failed_page; 542 543 block_write_end(NULL, inode->i_mapping, pos, blocksize, 544 blocksize, page, NULL); 545 546 unlock_page(page); 547 page_cache_release(page); 548 549 (*nr_salvaged_blocks)++; 550 goto next; 551 552 failed_page: 553 unlock_page(page); 554 page_cache_release(page); 555 556 failed_inode: 557 printk(KERN_WARNING 558 "NILFS warning: error recovering data block " 559 "(err=%d, ino=%lu, block-offset=%llu)\n", 560 err, (unsigned long)rb->ino, 561 (unsigned long long)rb->blkoff); 562 if (!err2) 563 err2 = err; 564 next: 565 iput(inode); /* iput(NULL) is just ignored */ 566 list_del_init(&rb->list); 567 kfree(rb); 568 } 569 return err2; 570} 571 572/** 573 * nilfs_do_roll_forward - salvage logical segments newer than the latest 574 * checkpoint 575 * @nilfs: nilfs object 576 * @sbi: nilfs_sb_info 577 * @ri: pointer to a nilfs_recovery_info 578 */ 579static int nilfs_do_roll_forward(struct the_nilfs *nilfs, 580 struct nilfs_sb_info *sbi, 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 nilfs_attach_writer(nilfs, sbi); 601 pseg_start = ri->ri_lsegs_start; 602 seg_seq = ri->ri_lsegs_start_seq; 603 segnum = nilfs_get_segnum_of_block(nilfs, pseg_start); 604 nilfs_get_segment_range(nilfs, segnum, &seg_start, &seg_end); 605 606 while (segnum != ri->ri_segnum || pseg_start <= ri->ri_pseg_start) { 607 brelse(bh_sum); 608 bh_sum = nilfs_read_log_header(nilfs, pseg_start, &sum); 609 if (!bh_sum) { 610 err = -EIO; 611 goto failed; 612 } 613 614 ret = nilfs_validate_log(nilfs, seg_seq, bh_sum, sum); 615 if (ret) { 616 if (ret == NILFS_SEG_FAIL_IO) { 617 err = -EIO; 618 goto failed; 619 } 620 goto strayed; 621 } 622 623 flags = le16_to_cpu(sum->ss_flags); 624 if (flags & NILFS_SS_SR) 625 goto confused; 626 627 /* Found a valid partial segment; do recovery actions */ 628 nextnum = nilfs_get_segnum_of_block(nilfs, 629 le64_to_cpu(sum->ss_next)); 630 empty_seg = 0; 631 nilfs->ns_ctime = le64_to_cpu(sum->ss_create); 632 if (!(flags & NILFS_SS_GC)) 633 nilfs->ns_nongc_ctime = nilfs->ns_ctime; 634 635 switch (state) { 636 case RF_INIT_ST: 637 if (!(flags & NILFS_SS_LOGBGN) || 638 !(flags & NILFS_SS_SYNDT)) 639 goto try_next_pseg; 640 state = RF_DSYNC_ST; 641 /* Fall through */ 642 case RF_DSYNC_ST: 643 if (!(flags & NILFS_SS_SYNDT)) 644 goto confused; 645 646 err = nilfs_scan_dsync_log(nilfs, pseg_start, sum, 647 &dsync_blocks); 648 if (unlikely(err)) 649 goto failed; 650 if (flags & NILFS_SS_LOGEND) { 651 err = nilfs_recover_dsync_blocks( 652 nilfs, sbi, &dsync_blocks, 653 &nsalvaged_blocks); 654 if (unlikely(err)) 655 goto failed; 656 state = RF_INIT_ST; 657 } 658 break; /* Fall through to try_next_pseg */ 659 } 660 661 try_next_pseg: 662 if (pseg_start == ri->ri_lsegs_end) 663 break; 664 pseg_start += le32_to_cpu(sum->ss_nblocks); 665 if (pseg_start < seg_end) 666 continue; 667 goto feed_segment; 668 669 strayed: 670 if (pseg_start == ri->ri_lsegs_end) 671 break; 672 673 feed_segment: 674 /* Looking to the next full segment */ 675 if (empty_seg++) 676 break; 677 seg_seq++; 678 segnum = nextnum; 679 nilfs_get_segment_range(nilfs, segnum, &seg_start, &seg_end); 680 pseg_start = seg_start; 681 } 682 683 if (nsalvaged_blocks) { 684 printk(KERN_INFO "NILFS (device %s): salvaged %lu blocks\n", 685 sbi->s_super->s_id, nsalvaged_blocks); 686 ri->ri_need_recovery = NILFS_RECOVERY_ROLLFORWARD_DONE; 687 } 688 out: 689 brelse(bh_sum); 690 dispose_recovery_list(&dsync_blocks); 691 nilfs_detach_writer(nilfs, sbi); 692 return err; 693 694 confused: 695 err = -EINVAL; 696 failed: 697 printk(KERN_ERR 698 "NILFS (device %s): Error roll-forwarding " 699 "(err=%d, pseg block=%llu). ", 700 sbi->s_super->s_id, err, (unsigned long long)pseg_start); 701 goto out; 702} 703 704static void nilfs_finish_roll_forward(struct the_nilfs *nilfs, 705 struct nilfs_recovery_info *ri) 706{ 707 struct buffer_head *bh; 708 int err; 709 710 if (nilfs_get_segnum_of_block(nilfs, ri->ri_lsegs_start) != 711 nilfs_get_segnum_of_block(nilfs, ri->ri_super_root)) 712 return; 713 714 bh = __getblk(nilfs->ns_bdev, ri->ri_lsegs_start, nilfs->ns_blocksize); 715 BUG_ON(!bh); 716 memset(bh->b_data, 0, bh->b_size); 717 set_buffer_dirty(bh); 718 err = sync_dirty_buffer(bh); 719 if (unlikely(err)) 720 printk(KERN_WARNING 721 "NILFS warning: buffer sync write failed during " 722 "post-cleaning of recovery.\n"); 723 brelse(bh); 724} 725 726/** 727 * nilfs_salvage_orphan_logs - salvage logs written after the latest checkpoint 728 * @nilfs: nilfs object 729 * @sbi: nilfs_sb_info 730 * @ri: pointer to a nilfs_recovery_info struct to store search results. 731 * 732 * Return Value: On success, 0 is returned. On error, one of the following 733 * negative error code is returned. 734 * 735 * %-EINVAL - Inconsistent filesystem state. 736 * 737 * %-EIO - I/O error 738 * 739 * %-ENOSPC - No space left on device (only in a panic state). 740 * 741 * %-ERESTARTSYS - Interrupted. 742 * 743 * %-ENOMEM - Insufficient memory available. 744 */ 745int nilfs_salvage_orphan_logs(struct the_nilfs *nilfs, 746 struct nilfs_sb_info *sbi, 747 struct nilfs_recovery_info *ri) 748{ 749 int err; 750 751 if (ri->ri_lsegs_start == 0 || ri->ri_lsegs_end == 0) 752 return 0; 753 754 err = nilfs_attach_checkpoint(sbi, ri->ri_cno); 755 if (unlikely(err)) { 756 printk(KERN_ERR 757 "NILFS: error loading the latest checkpoint.\n"); 758 return err; 759 } 760 761 err = nilfs_do_roll_forward(nilfs, sbi, ri); 762 if (unlikely(err)) 763 goto failed; 764 765 if (ri->ri_need_recovery == NILFS_RECOVERY_ROLLFORWARD_DONE) { 766 err = nilfs_prepare_segment_for_recovery(nilfs, sbi, ri); 767 if (unlikely(err)) { 768 printk(KERN_ERR "NILFS: Error preparing segments for " 769 "recovery.\n"); 770 goto failed; 771 } 772 773 err = nilfs_attach_segment_constructor(sbi); 774 if (unlikely(err)) 775 goto failed; 776 777 set_nilfs_discontinued(nilfs); 778 err = nilfs_construct_segment(sbi->s_super); 779 nilfs_detach_segment_constructor(sbi); 780 781 if (unlikely(err)) { 782 printk(KERN_ERR "NILFS: Oops! recovery failed. " 783 "(err=%d)\n", err); 784 goto failed; 785 } 786 787 nilfs_finish_roll_forward(nilfs, ri); 788 } 789 790 failed: 791 nilfs_detach_checkpoint(sbi); 792 return err; 793} 794 795/** 796 * nilfs_search_super_root - search the latest valid super root 797 * @nilfs: the_nilfs 798 * @ri: pointer to a nilfs_recovery_info struct to store search results. 799 * 800 * nilfs_search_super_root() looks for the latest super-root from a partial 801 * segment pointed by the superblock. It sets up struct the_nilfs through 802 * this search. It fills nilfs_recovery_info (ri) required for recovery. 803 * 804 * Return Value: On success, 0 is returned. On error, one of the following 805 * negative error code is returned. 806 * 807 * %-EINVAL - No valid segment found 808 * 809 * %-EIO - I/O error 810 * 811 * %-ENOMEM - Insufficient memory available. 812 */ 813int nilfs_search_super_root(struct the_nilfs *nilfs, 814 struct nilfs_recovery_info *ri) 815{ 816 struct buffer_head *bh_sum = NULL; 817 struct nilfs_segment_summary *sum; 818 sector_t pseg_start, pseg_end, sr_pseg_start = 0; 819 sector_t seg_start, seg_end; /* range of full segment (block number) */ 820 sector_t b, end; 821 unsigned long nblocks; 822 unsigned int flags; 823 u64 seg_seq; 824 __u64 segnum, nextnum = 0; 825 __u64 cno; 826 LIST_HEAD(segments); 827 int empty_seg = 0, scan_newer = 0; 828 int ret; 829 830 pseg_start = nilfs->ns_last_pseg; 831 seg_seq = nilfs->ns_last_seq; 832 cno = nilfs->ns_last_cno; 833 segnum = nilfs_get_segnum_of_block(nilfs, pseg_start); 834 835 /* Calculate range of segment */ 836 nilfs_get_segment_range(nilfs, segnum, &seg_start, &seg_end); 837 838 /* Read ahead segment */ 839 b = seg_start; 840 while (b <= seg_end) 841 __breadahead(nilfs->ns_bdev, b++, nilfs->ns_blocksize); 842 843 for (;;) { 844 brelse(bh_sum); 845 ret = NILFS_SEG_FAIL_IO; 846 bh_sum = nilfs_read_log_header(nilfs, pseg_start, &sum); 847 if (!bh_sum) 848 goto failed; 849 850 ret = nilfs_validate_log(nilfs, seg_seq, bh_sum, sum); 851 if (ret) { 852 if (ret == NILFS_SEG_FAIL_IO) 853 goto failed; 854 goto strayed; 855 } 856 857 nblocks = le32_to_cpu(sum->ss_nblocks); 858 pseg_end = pseg_start + nblocks - 1; 859 if (unlikely(pseg_end > seg_end)) { 860 ret = NILFS_SEG_FAIL_CONSISTENCY; 861 goto strayed; 862 } 863 864 /* A valid partial segment */ 865 ri->ri_pseg_start = pseg_start; 866 ri->ri_seq = seg_seq; 867 ri->ri_segnum = segnum; 868 nextnum = nilfs_get_segnum_of_block(nilfs, 869 le64_to_cpu(sum->ss_next)); 870 ri->ri_nextnum = nextnum; 871 empty_seg = 0; 872 873 flags = le16_to_cpu(sum->ss_flags); 874 if (!(flags & NILFS_SS_SR) && !scan_newer) { 875 /* This will never happen because a superblock 876 (last_segment) always points to a pseg 877 having a super root. */ 878 ret = NILFS_SEG_FAIL_CONSISTENCY; 879 goto failed; 880 } 881 882 if (pseg_start == seg_start) { 883 nilfs_get_segment_range(nilfs, nextnum, &b, &end); 884 while (b <= end) 885 __breadahead(nilfs->ns_bdev, b++, 886 nilfs->ns_blocksize); 887 } 888 if (!(flags & NILFS_SS_SR)) { 889 if (!ri->ri_lsegs_start && (flags & NILFS_SS_LOGBGN)) { 890 ri->ri_lsegs_start = pseg_start; 891 ri->ri_lsegs_start_seq = seg_seq; 892 } 893 if (flags & NILFS_SS_LOGEND) 894 ri->ri_lsegs_end = pseg_start; 895 goto try_next_pseg; 896 } 897 898 /* A valid super root was found. */ 899 ri->ri_cno = cno++; 900 ri->ri_super_root = pseg_end; 901 ri->ri_lsegs_start = ri->ri_lsegs_end = 0; 902 903 nilfs_dispose_segment_list(&segments); 904 sr_pseg_start = pseg_start; 905 nilfs->ns_pseg_offset = pseg_start + nblocks - seg_start; 906 nilfs->ns_seg_seq = seg_seq; 907 nilfs->ns_segnum = segnum; 908 nilfs->ns_cno = cno; /* nilfs->ns_cno = ri->ri_cno + 1 */ 909 nilfs->ns_ctime = le64_to_cpu(sum->ss_create); 910 nilfs->ns_nextnum = nextnum; 911 912 if (scan_newer) 913 ri->ri_need_recovery = NILFS_RECOVERY_SR_UPDATED; 914 else { 915 if (nilfs->ns_mount_state & NILFS_VALID_FS) 916 goto super_root_found; 917 scan_newer = 1; 918 } 919 920 try_next_pseg: 921 /* Standing on a course, or met an inconsistent state */ 922 pseg_start += nblocks; 923 if (pseg_start < seg_end) 924 continue; 925 goto feed_segment; 926 927 strayed: 928 /* Off the trail */ 929 if (!scan_newer) 930 /* 931 * This can happen if a checkpoint was written without 932 * barriers, or as a result of an I/O failure. 933 */ 934 goto failed; 935 936 feed_segment: 937 /* Looking to the next full segment */ 938 if (empty_seg++) 939 goto super_root_found; /* found a valid super root */ 940 941 ret = nilfs_segment_list_add(&segments, segnum); 942 if (unlikely(ret)) 943 goto failed; 944 945 seg_seq++; 946 segnum = nextnum; 947 nilfs_get_segment_range(nilfs, segnum, &seg_start, &seg_end); 948 pseg_start = seg_start; 949 } 950 951 super_root_found: 952 /* Updating pointers relating to the latest checkpoint */ 953 brelse(bh_sum); 954 list_splice_tail(&segments, &ri->ri_used_segments); 955 nilfs->ns_last_pseg = sr_pseg_start; 956 nilfs->ns_last_seq = nilfs->ns_seg_seq; 957 nilfs->ns_last_cno = ri->ri_cno; 958 return 0; 959 960 failed: 961 brelse(bh_sum); 962 nilfs_dispose_segment_list(&segments); 963 return (ret < 0) ? ret : nilfs_warn_segment_error(ret); 964} 965