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1// SPDX-License-Identifier: GPL-2.02/*3 * Copyright (c) 2000-2006 Silicon Graphics, Inc.4 * All Rights Reserved.5 */6#include "xfs.h"7#include "xfs_fs.h"8#include "xfs_shared.h"9#include "xfs_format.h"10#include "xfs_log_format.h"11#include "xfs_trans_resv.h"12#include "xfs_bit.h"13#include "xfs_sb.h"14#include "xfs_mount.h"15#include "xfs_defer.h"16#include "xfs_inode.h"17#include "xfs_trans.h"18#include "xfs_log.h"19#include "xfs_log_priv.h"20#include "xfs_log_recover.h"21#include "xfs_trans_priv.h"22#include "xfs_alloc.h"23#include "xfs_ialloc.h"24#include "xfs_trace.h"25#include "xfs_icache.h"26#include "xfs_error.h"27#include "xfs_buf_item.h"28#include "xfs_ag.h"29#include "xfs_quota.h"30#include "xfs_reflink.h"31 32#define BLK_AVG(blk1, blk2) ((blk1+blk2) >> 1)33 34STATIC int35xlog_find_zeroed(36 struct xlog *,37 xfs_daddr_t *);38STATIC int39xlog_clear_stale_blocks(40 struct xlog *,41 xfs_lsn_t);42STATIC int43xlog_do_recovery_pass(44 struct xlog *, xfs_daddr_t, xfs_daddr_t, int, xfs_daddr_t *);45 46/*47 * Sector aligned buffer routines for buffer create/read/write/access48 */49 50/*51 * Verify the log-relative block number and length in basic blocks are valid for52 * an operation involving the given XFS log buffer. Returns true if the fields53 * are valid, false otherwise.54 */55static inline bool56xlog_verify_bno(57 struct xlog *log,58 xfs_daddr_t blk_no,59 int bbcount)60{61 if (blk_no < 0 || blk_no >= log->l_logBBsize)62 return false;63 if (bbcount <= 0 || (blk_no + bbcount) > log->l_logBBsize)64 return false;65 return true;66}67 68/*69 * Allocate a buffer to hold log data. The buffer needs to be able to map to70 * a range of nbblks basic blocks at any valid offset within the log.71 */72static char *73xlog_alloc_buffer(74 struct xlog *log,75 int nbblks)76{77 /*78 * Pass log block 0 since we don't have an addr yet, buffer will be79 * verified on read.80 */81 if (XFS_IS_CORRUPT(log->l_mp, !xlog_verify_bno(log, 0, nbblks))) {82 xfs_warn(log->l_mp, "Invalid block length (0x%x) for buffer",83 nbblks);84 return NULL;85 }86 87 /*88 * We do log I/O in units of log sectors (a power-of-2 multiple of the89 * basic block size), so we round up the requested size to accommodate90 * the basic blocks required for complete log sectors.91 *92 * In addition, the buffer may be used for a non-sector-aligned block93 * offset, in which case an I/O of the requested size could extend94 * beyond the end of the buffer. If the requested size is only 1 basic95 * block it will never straddle a sector boundary, so this won't be an96 * issue. Nor will this be a problem if the log I/O is done in basic97 * blocks (sector size 1). But otherwise we extend the buffer by one98 * extra log sector to ensure there's space to accommodate this99 * possibility.100 */101 if (nbblks > 1 && log->l_sectBBsize > 1)102 nbblks += log->l_sectBBsize;103 nbblks = round_up(nbblks, log->l_sectBBsize);104 return kvzalloc(BBTOB(nbblks), GFP_KERNEL | __GFP_RETRY_MAYFAIL);105}106 107/*108 * Return the address of the start of the given block number's data109 * in a log buffer. The buffer covers a log sector-aligned region.110 */111static inline unsigned int112xlog_align(113 struct xlog *log,114 xfs_daddr_t blk_no)115{116 return BBTOB(blk_no & ((xfs_daddr_t)log->l_sectBBsize - 1));117}118 119static int120xlog_do_io(121 struct xlog *log,122 xfs_daddr_t blk_no,123 unsigned int nbblks,124 char *data,125 enum req_op op)126{127 int error;128 129 if (XFS_IS_CORRUPT(log->l_mp, !xlog_verify_bno(log, blk_no, nbblks))) {130 xfs_warn(log->l_mp,131 "Invalid log block/length (0x%llx, 0x%x) for buffer",132 blk_no, nbblks);133 return -EFSCORRUPTED;134 }135 136 blk_no = round_down(blk_no, log->l_sectBBsize);137 nbblks = round_up(nbblks, log->l_sectBBsize);138 ASSERT(nbblks > 0);139 140 error = xfs_rw_bdev(log->l_targ->bt_bdev, log->l_logBBstart + blk_no,141 BBTOB(nbblks), data, op);142 if (error && !xlog_is_shutdown(log)) {143 xfs_alert(log->l_mp,144 "log recovery %s I/O error at daddr 0x%llx len %d error %d",145 op == REQ_OP_WRITE ? "write" : "read",146 blk_no, nbblks, error);147 }148 return error;149}150 151STATIC int152xlog_bread_noalign(153 struct xlog *log,154 xfs_daddr_t blk_no,155 int nbblks,156 char *data)157{158 return xlog_do_io(log, blk_no, nbblks, data, REQ_OP_READ);159}160 161STATIC int162xlog_bread(163 struct xlog *log,164 xfs_daddr_t blk_no,165 int nbblks,166 char *data,167 char **offset)168{169 int error;170 171 error = xlog_do_io(log, blk_no, nbblks, data, REQ_OP_READ);172 if (!error)173 *offset = data + xlog_align(log, blk_no);174 return error;175}176 177STATIC int178xlog_bwrite(179 struct xlog *log,180 xfs_daddr_t blk_no,181 int nbblks,182 char *data)183{184 return xlog_do_io(log, blk_no, nbblks, data, REQ_OP_WRITE);185}186 187#ifdef DEBUG188/*189 * dump debug superblock and log record information190 */191STATIC void192xlog_header_check_dump(193 xfs_mount_t *mp,194 xlog_rec_header_t *head)195{196 xfs_debug(mp, "%s: SB : uuid = %pU, fmt = %d",197 __func__, &mp->m_sb.sb_uuid, XLOG_FMT);198 xfs_debug(mp, " log : uuid = %pU, fmt = %d",199 &head->h_fs_uuid, be32_to_cpu(head->h_fmt));200}201#else202#define xlog_header_check_dump(mp, head)203#endif204 205/*206 * check log record header for recovery207 */208STATIC int209xlog_header_check_recover(210 xfs_mount_t *mp,211 xlog_rec_header_t *head)212{213 ASSERT(head->h_magicno == cpu_to_be32(XLOG_HEADER_MAGIC_NUM));214 215 /*216 * IRIX doesn't write the h_fmt field and leaves it zeroed217 * (XLOG_FMT_UNKNOWN). This stops us from trying to recover218 * a dirty log created in IRIX.219 */220 if (XFS_IS_CORRUPT(mp, head->h_fmt != cpu_to_be32(XLOG_FMT))) {221 xfs_warn(mp,222 "dirty log written in incompatible format - can't recover");223 xlog_header_check_dump(mp, head);224 return -EFSCORRUPTED;225 }226 if (XFS_IS_CORRUPT(mp, !uuid_equal(&mp->m_sb.sb_uuid,227 &head->h_fs_uuid))) {228 xfs_warn(mp,229 "dirty log entry has mismatched uuid - can't recover");230 xlog_header_check_dump(mp, head);231 return -EFSCORRUPTED;232 }233 return 0;234}235 236/*237 * read the head block of the log and check the header238 */239STATIC int240xlog_header_check_mount(241 xfs_mount_t *mp,242 xlog_rec_header_t *head)243{244 ASSERT(head->h_magicno == cpu_to_be32(XLOG_HEADER_MAGIC_NUM));245 246 if (uuid_is_null(&head->h_fs_uuid)) {247 /*248 * IRIX doesn't write the h_fs_uuid or h_fmt fields. If249 * h_fs_uuid is null, we assume this log was last mounted250 * by IRIX and continue.251 */252 xfs_warn(mp, "null uuid in log - IRIX style log");253 } else if (XFS_IS_CORRUPT(mp, !uuid_equal(&mp->m_sb.sb_uuid,254 &head->h_fs_uuid))) {255 xfs_warn(mp, "log has mismatched uuid - can't recover");256 xlog_header_check_dump(mp, head);257 return -EFSCORRUPTED;258 }259 return 0;260}261 262/*263 * This routine finds (to an approximation) the first block in the physical264 * log which contains the given cycle. It uses a binary search algorithm.265 * Note that the algorithm can not be perfect because the disk will not266 * necessarily be perfect.267 */268STATIC int269xlog_find_cycle_start(270 struct xlog *log,271 char *buffer,272 xfs_daddr_t first_blk,273 xfs_daddr_t *last_blk,274 uint cycle)275{276 char *offset;277 xfs_daddr_t mid_blk;278 xfs_daddr_t end_blk;279 uint mid_cycle;280 int error;281 282 end_blk = *last_blk;283 mid_blk = BLK_AVG(first_blk, end_blk);284 while (mid_blk != first_blk && mid_blk != end_blk) {285 error = xlog_bread(log, mid_blk, 1, buffer, &offset);286 if (error)287 return error;288 mid_cycle = xlog_get_cycle(offset);289 if (mid_cycle == cycle)290 end_blk = mid_blk; /* last_half_cycle == mid_cycle */291 else292 first_blk = mid_blk; /* first_half_cycle == mid_cycle */293 mid_blk = BLK_AVG(first_blk, end_blk);294 }295 ASSERT((mid_blk == first_blk && mid_blk+1 == end_blk) ||296 (mid_blk == end_blk && mid_blk-1 == first_blk));297 298 *last_blk = end_blk;299 300 return 0;301}302 303/*304 * Check that a range of blocks does not contain stop_on_cycle_no.305 * Fill in *new_blk with the block offset where such a block is306 * found, or with -1 (an invalid block number) if there is no such307 * block in the range. The scan needs to occur from front to back308 * and the pointer into the region must be updated since a later309 * routine will need to perform another test.310 */311STATIC int312xlog_find_verify_cycle(313 struct xlog *log,314 xfs_daddr_t start_blk,315 int nbblks,316 uint stop_on_cycle_no,317 xfs_daddr_t *new_blk)318{319 xfs_daddr_t i, j;320 uint cycle;321 char *buffer;322 xfs_daddr_t bufblks;323 char *buf = NULL;324 int error = 0;325 326 /*327 * Greedily allocate a buffer big enough to handle the full328 * range of basic blocks we'll be examining. If that fails,329 * try a smaller size. We need to be able to read at least330 * a log sector, or we're out of luck.331 */332 bufblks = roundup_pow_of_two(nbblks);333 while (bufblks > log->l_logBBsize)334 bufblks >>= 1;335 while (!(buffer = xlog_alloc_buffer(log, bufblks))) {336 bufblks >>= 1;337 if (bufblks < log->l_sectBBsize)338 return -ENOMEM;339 }340 341 for (i = start_blk; i < start_blk + nbblks; i += bufblks) {342 int bcount;343 344 bcount = min(bufblks, (start_blk + nbblks - i));345 346 error = xlog_bread(log, i, bcount, buffer, &buf);347 if (error)348 goto out;349 350 for (j = 0; j < bcount; j++) {351 cycle = xlog_get_cycle(buf);352 if (cycle == stop_on_cycle_no) {353 *new_blk = i+j;354 goto out;355 }356 357 buf += BBSIZE;358 }359 }360 361 *new_blk = -1;362 363out:364 kvfree(buffer);365 return error;366}367 368static inline int369xlog_logrec_hblks(struct xlog *log, struct xlog_rec_header *rh)370{371 if (xfs_has_logv2(log->l_mp)) {372 int h_size = be32_to_cpu(rh->h_size);373 374 if ((be32_to_cpu(rh->h_version) & XLOG_VERSION_2) &&375 h_size > XLOG_HEADER_CYCLE_SIZE)376 return DIV_ROUND_UP(h_size, XLOG_HEADER_CYCLE_SIZE);377 }378 return 1;379}380 381/*382 * Potentially backup over partial log record write.383 *384 * In the typical case, last_blk is the number of the block directly after385 * a good log record. Therefore, we subtract one to get the block number386 * of the last block in the given buffer. extra_bblks contains the number387 * of blocks we would have read on a previous read. This happens when the388 * last log record is split over the end of the physical log.389 *390 * extra_bblks is the number of blocks potentially verified on a previous391 * call to this routine.392 */393STATIC int394xlog_find_verify_log_record(395 struct xlog *log,396 xfs_daddr_t start_blk,397 xfs_daddr_t *last_blk,398 int extra_bblks)399{400 xfs_daddr_t i;401 char *buffer;402 char *offset = NULL;403 xlog_rec_header_t *head = NULL;404 int error = 0;405 int smallmem = 0;406 int num_blks = *last_blk - start_blk;407 int xhdrs;408 409 ASSERT(start_blk != 0 || *last_blk != start_blk);410 411 buffer = xlog_alloc_buffer(log, num_blks);412 if (!buffer) {413 buffer = xlog_alloc_buffer(log, 1);414 if (!buffer)415 return -ENOMEM;416 smallmem = 1;417 } else {418 error = xlog_bread(log, start_blk, num_blks, buffer, &offset);419 if (error)420 goto out;421 offset += ((num_blks - 1) << BBSHIFT);422 }423 424 for (i = (*last_blk) - 1; i >= 0; i--) {425 if (i < start_blk) {426 /* valid log record not found */427 xfs_warn(log->l_mp,428 "Log inconsistent (didn't find previous header)");429 ASSERT(0);430 error = -EFSCORRUPTED;431 goto out;432 }433 434 if (smallmem) {435 error = xlog_bread(log, i, 1, buffer, &offset);436 if (error)437 goto out;438 }439 440 head = (xlog_rec_header_t *)offset;441 442 if (head->h_magicno == cpu_to_be32(XLOG_HEADER_MAGIC_NUM))443 break;444 445 if (!smallmem)446 offset -= BBSIZE;447 }448 449 /*450 * We hit the beginning of the physical log & still no header. Return451 * to caller. If caller can handle a return of -1, then this routine452 * will be called again for the end of the physical log.453 */454 if (i == -1) {455 error = 1;456 goto out;457 }458 459 /*460 * We have the final block of the good log (the first block461 * of the log record _before_ the head. So we check the uuid.462 */463 if ((error = xlog_header_check_mount(log->l_mp, head)))464 goto out;465 466 /*467 * We may have found a log record header before we expected one.468 * last_blk will be the 1st block # with a given cycle #. We may end469 * up reading an entire log record. In this case, we don't want to470 * reset last_blk. Only when last_blk points in the middle of a log471 * record do we update last_blk.472 */473 xhdrs = xlog_logrec_hblks(log, head);474 475 if (*last_blk - i + extra_bblks !=476 BTOBB(be32_to_cpu(head->h_len)) + xhdrs)477 *last_blk = i;478 479out:480 kvfree(buffer);481 return error;482}483 484/*485 * Head is defined to be the point of the log where the next log write486 * could go. This means that incomplete LR writes at the end are487 * eliminated when calculating the head. We aren't guaranteed that previous488 * LR have complete transactions. We only know that a cycle number of489 * current cycle number -1 won't be present in the log if we start writing490 * from our current block number.491 *492 * last_blk contains the block number of the first block with a given493 * cycle number.494 *495 * Return: zero if normal, non-zero if error.496 */497STATIC int498xlog_find_head(499 struct xlog *log,500 xfs_daddr_t *return_head_blk)501{502 char *buffer;503 char *offset;504 xfs_daddr_t new_blk, first_blk, start_blk, last_blk, head_blk;505 int num_scan_bblks;506 uint first_half_cycle, last_half_cycle;507 uint stop_on_cycle;508 int error, log_bbnum = log->l_logBBsize;509 510 /* Is the end of the log device zeroed? */511 error = xlog_find_zeroed(log, &first_blk);512 if (error < 0) {513 xfs_warn(log->l_mp, "empty log check failed");514 return error;515 }516 if (error == 1) {517 *return_head_blk = first_blk;518 519 /* Is the whole lot zeroed? */520 if (!first_blk) {521 /* Linux XFS shouldn't generate totally zeroed logs -522 * mkfs etc write a dummy unmount record to a fresh523 * log so we can store the uuid in there524 */525 xfs_warn(log->l_mp, "totally zeroed log");526 }527 528 return 0;529 }530 531 first_blk = 0; /* get cycle # of 1st block */532 buffer = xlog_alloc_buffer(log, 1);533 if (!buffer)534 return -ENOMEM;535 536 error = xlog_bread(log, 0, 1, buffer, &offset);537 if (error)538 goto out_free_buffer;539 540 first_half_cycle = xlog_get_cycle(offset);541 542 last_blk = head_blk = log_bbnum - 1; /* get cycle # of last block */543 error = xlog_bread(log, last_blk, 1, buffer, &offset);544 if (error)545 goto out_free_buffer;546 547 last_half_cycle = xlog_get_cycle(offset);548 ASSERT(last_half_cycle != 0);549 550 /*551 * If the 1st half cycle number is equal to the last half cycle number,552 * then the entire log is stamped with the same cycle number. In this553 * case, head_blk can't be set to zero (which makes sense). The below554 * math doesn't work out properly with head_blk equal to zero. Instead,555 * we set it to log_bbnum which is an invalid block number, but this556 * value makes the math correct. If head_blk doesn't changed through557 * all the tests below, *head_blk is set to zero at the very end rather558 * than log_bbnum. In a sense, log_bbnum and zero are the same block559 * in a circular file.560 */561 if (first_half_cycle == last_half_cycle) {562 /*563 * In this case we believe that the entire log should have564 * cycle number last_half_cycle. We need to scan backwards565 * from the end verifying that there are no holes still566 * containing last_half_cycle - 1. If we find such a hole,567 * then the start of that hole will be the new head. The568 * simple case looks like569 * x | x ... | x - 1 | x570 * Another case that fits this picture would be571 * x | x + 1 | x ... | x572 * In this case the head really is somewhere at the end of the573 * log, as one of the latest writes at the beginning was574 * incomplete.575 * One more case is576 * x | x + 1 | x ... | x - 1 | x577 * This is really the combination of the above two cases, and578 * the head has to end up at the start of the x-1 hole at the579 * end of the log.580 *581 * In the 256k log case, we will read from the beginning to the582 * end of the log and search for cycle numbers equal to x-1.583 * We don't worry about the x+1 blocks that we encounter,584 * because we know that they cannot be the head since the log585 * started with x.586 */587 head_blk = log_bbnum;588 stop_on_cycle = last_half_cycle - 1;589 } else {590 /*591 * In this case we want to find the first block with cycle592 * number matching last_half_cycle. We expect the log to be593 * some variation on594 * x + 1 ... | x ... | x595 * The first block with cycle number x (last_half_cycle) will596 * be where the new head belongs. First we do a binary search597 * for the first occurrence of last_half_cycle. The binary598 * search may not be totally accurate, so then we scan back599 * from there looking for occurrences of last_half_cycle before600 * us. If that backwards scan wraps around the beginning of601 * the log, then we look for occurrences of last_half_cycle - 1602 * at the end of the log. The cases we're looking for look603 * like604 * v binary search stopped here605 * x + 1 ... | x | x + 1 | x ... | x606 * ^ but we want to locate this spot607 * or608 * <---------> less than scan distance609 * x + 1 ... | x ... | x - 1 | x610 * ^ we want to locate this spot611 */612 stop_on_cycle = last_half_cycle;613 error = xlog_find_cycle_start(log, buffer, first_blk, &head_blk,614 last_half_cycle);615 if (error)616 goto out_free_buffer;617 }618 619 /*620 * Now validate the answer. Scan back some number of maximum possible621 * blocks and make sure each one has the expected cycle number. The622 * maximum is determined by the total possible amount of buffering623 * in the in-core log. The following number can be made tighter if624 * we actually look at the block size of the filesystem.625 */626 num_scan_bblks = min_t(int, log_bbnum, XLOG_TOTAL_REC_SHIFT(log));627 if (head_blk >= num_scan_bblks) {628 /*629 * We are guaranteed that the entire check can be performed630 * in one buffer.631 */632 start_blk = head_blk - num_scan_bblks;633 if ((error = xlog_find_verify_cycle(log,634 start_blk, num_scan_bblks,635 stop_on_cycle, &new_blk)))636 goto out_free_buffer;637 if (new_blk != -1)638 head_blk = new_blk;639 } else { /* need to read 2 parts of log */640 /*641 * We are going to scan backwards in the log in two parts.642 * First we scan the physical end of the log. In this part643 * of the log, we are looking for blocks with cycle number644 * last_half_cycle - 1.645 * If we find one, then we know that the log starts there, as646 * we've found a hole that didn't get written in going around647 * the end of the physical log. The simple case for this is648 * x + 1 ... | x ... | x - 1 | x649 * <---------> less than scan distance650 * If all of the blocks at the end of the log have cycle number651 * last_half_cycle, then we check the blocks at the start of652 * the log looking for occurrences of last_half_cycle. If we653 * find one, then our current estimate for the location of the654 * first occurrence of last_half_cycle is wrong and we move655 * back to the hole we've found. This case looks like656 * x + 1 ... | x | x + 1 | x ...657 * ^ binary search stopped here658 * Another case we need to handle that only occurs in 256k659 * logs is660 * x + 1 ... | x ... | x+1 | x ...661 * ^ binary search stops here662 * In a 256k log, the scan at the end of the log will see the663 * x + 1 blocks. We need to skip past those since that is664 * certainly not the head of the log. By searching for665 * last_half_cycle-1 we accomplish that.666 */667 ASSERT(head_blk <= INT_MAX &&668 (xfs_daddr_t) num_scan_bblks >= head_blk);669 start_blk = log_bbnum - (num_scan_bblks - head_blk);670 if ((error = xlog_find_verify_cycle(log, start_blk,671 num_scan_bblks - (int)head_blk,672 (stop_on_cycle - 1), &new_blk)))673 goto out_free_buffer;674 if (new_blk != -1) {675 head_blk = new_blk;676 goto validate_head;677 }678 679 /*680 * Scan beginning of log now. The last part of the physical681 * log is good. This scan needs to verify that it doesn't find682 * the last_half_cycle.683 */684 start_blk = 0;685 ASSERT(head_blk <= INT_MAX);686 if ((error = xlog_find_verify_cycle(log,687 start_blk, (int)head_blk,688 stop_on_cycle, &new_blk)))689 goto out_free_buffer;690 if (new_blk != -1)691 head_blk = new_blk;692 }693 694validate_head:695 /*696 * Now we need to make sure head_blk is not pointing to a block in697 * the middle of a log record.698 */699 num_scan_bblks = XLOG_REC_SHIFT(log);700 if (head_blk >= num_scan_bblks) {701 start_blk = head_blk - num_scan_bblks; /* don't read head_blk */702 703 /* start ptr at last block ptr before head_blk */704 error = xlog_find_verify_log_record(log, start_blk, &head_blk, 0);705 if (error == 1)706 error = -EIO;707 if (error)708 goto out_free_buffer;709 } else {710 start_blk = 0;711 ASSERT(head_blk <= INT_MAX);712 error = xlog_find_verify_log_record(log, start_blk, &head_blk, 0);713 if (error < 0)714 goto out_free_buffer;715 if (error == 1) {716 /* We hit the beginning of the log during our search */717 start_blk = log_bbnum - (num_scan_bblks - head_blk);718 new_blk = log_bbnum;719 ASSERT(start_blk <= INT_MAX &&720 (xfs_daddr_t) log_bbnum-start_blk >= 0);721 ASSERT(head_blk <= INT_MAX);722 error = xlog_find_verify_log_record(log, start_blk,723 &new_blk, (int)head_blk);724 if (error == 1)725 error = -EIO;726 if (error)727 goto out_free_buffer;728 if (new_blk != log_bbnum)729 head_blk = new_blk;730 } else if (error)731 goto out_free_buffer;732 }733 734 kvfree(buffer);735 if (head_blk == log_bbnum)736 *return_head_blk = 0;737 else738 *return_head_blk = head_blk;739 /*740 * When returning here, we have a good block number. Bad block741 * means that during a previous crash, we didn't have a clean break742 * from cycle number N to cycle number N-1. In this case, we need743 * to find the first block with cycle number N-1.744 */745 return 0;746 747out_free_buffer:748 kvfree(buffer);749 if (error)750 xfs_warn(log->l_mp, "failed to find log head");751 return error;752}753 754/*755 * Seek backwards in the log for log record headers.756 *757 * Given a starting log block, walk backwards until we find the provided number758 * of records or hit the provided tail block. The return value is the number of759 * records encountered or a negative error code. The log block and buffer760 * pointer of the last record seen are returned in rblk and rhead respectively.761 */762STATIC int763xlog_rseek_logrec_hdr(764 struct xlog *log,765 xfs_daddr_t head_blk,766 xfs_daddr_t tail_blk,767 int count,768 char *buffer,769 xfs_daddr_t *rblk,770 struct xlog_rec_header **rhead,771 bool *wrapped)772{773 int i;774 int error;775 int found = 0;776 char *offset = NULL;777 xfs_daddr_t end_blk;778 779 *wrapped = false;780 781 /*782 * Walk backwards from the head block until we hit the tail or the first783 * block in the log.784 */785 end_blk = head_blk > tail_blk ? tail_blk : 0;786 for (i = (int) head_blk - 1; i >= end_blk; i--) {787 error = xlog_bread(log, i, 1, buffer, &offset);788 if (error)789 goto out_error;790 791 if (*(__be32 *) offset == cpu_to_be32(XLOG_HEADER_MAGIC_NUM)) {792 *rblk = i;793 *rhead = (struct xlog_rec_header *) offset;794 if (++found == count)795 break;796 }797 }798 799 /*800 * If we haven't hit the tail block or the log record header count,801 * start looking again from the end of the physical log. Note that802 * callers can pass head == tail if the tail is not yet known.803 */804 if (tail_blk >= head_blk && found != count) {805 for (i = log->l_logBBsize - 1; i >= (int) tail_blk; i--) {806 error = xlog_bread(log, i, 1, buffer, &offset);807 if (error)808 goto out_error;809 810 if (*(__be32 *)offset ==811 cpu_to_be32(XLOG_HEADER_MAGIC_NUM)) {812 *wrapped = true;813 *rblk = i;814 *rhead = (struct xlog_rec_header *) offset;815 if (++found == count)816 break;817 }818 }819 }820 821 return found;822 823out_error:824 return error;825}826 827/*828 * Seek forward in the log for log record headers.829 *830 * Given head and tail blocks, walk forward from the tail block until we find831 * the provided number of records or hit the head block. The return value is the832 * number of records encountered or a negative error code. The log block and833 * buffer pointer of the last record seen are returned in rblk and rhead834 * respectively.835 */836STATIC int837xlog_seek_logrec_hdr(838 struct xlog *log,839 xfs_daddr_t head_blk,840 xfs_daddr_t tail_blk,841 int count,842 char *buffer,843 xfs_daddr_t *rblk,844 struct xlog_rec_header **rhead,845 bool *wrapped)846{847 int i;848 int error;849 int found = 0;850 char *offset = NULL;851 xfs_daddr_t end_blk;852 853 *wrapped = false;854 855 /*856 * Walk forward from the tail block until we hit the head or the last857 * block in the log.858 */859 end_blk = head_blk > tail_blk ? head_blk : log->l_logBBsize - 1;860 for (i = (int) tail_blk; i <= end_blk; i++) {861 error = xlog_bread(log, i, 1, buffer, &offset);862 if (error)863 goto out_error;864 865 if (*(__be32 *) offset == cpu_to_be32(XLOG_HEADER_MAGIC_NUM)) {866 *rblk = i;867 *rhead = (struct xlog_rec_header *) offset;868 if (++found == count)869 break;870 }871 }872 873 /*874 * If we haven't hit the head block or the log record header count,875 * start looking again from the start of the physical log.876 */877 if (tail_blk > head_blk && found != count) {878 for (i = 0; i < (int) head_blk; i++) {879 error = xlog_bread(log, i, 1, buffer, &offset);880 if (error)881 goto out_error;882 883 if (*(__be32 *)offset ==884 cpu_to_be32(XLOG_HEADER_MAGIC_NUM)) {885 *wrapped = true;886 *rblk = i;887 *rhead = (struct xlog_rec_header *) offset;888 if (++found == count)889 break;890 }891 }892 }893 894 return found;895 896out_error:897 return error;898}899 900/*901 * Calculate distance from head to tail (i.e., unused space in the log).902 */903static inline int904xlog_tail_distance(905 struct xlog *log,906 xfs_daddr_t head_blk,907 xfs_daddr_t tail_blk)908{909 if (head_blk < tail_blk)910 return tail_blk - head_blk;911 912 return tail_blk + (log->l_logBBsize - head_blk);913}914 915/*916 * Verify the log tail. This is particularly important when torn or incomplete917 * writes have been detected near the front of the log and the head has been918 * walked back accordingly.919 *920 * We also have to handle the case where the tail was pinned and the head921 * blocked behind the tail right before a crash. If the tail had been pushed922 * immediately prior to the crash and the subsequent checkpoint was only923 * partially written, it's possible it overwrote the last referenced tail in the924 * log with garbage. This is not a coherency problem because the tail must have925 * been pushed before it can be overwritten, but appears as log corruption to926 * recovery because we have no way to know the tail was updated if the927 * subsequent checkpoint didn't write successfully.928 *929 * Therefore, CRC check the log from tail to head. If a failure occurs and the930 * offending record is within max iclog bufs from the head, walk the tail931 * forward and retry until a valid tail is found or corruption is detected out932 * of the range of a possible overwrite.933 */934STATIC int935xlog_verify_tail(936 struct xlog *log,937 xfs_daddr_t head_blk,938 xfs_daddr_t *tail_blk,939 int hsize)940{941 struct xlog_rec_header *thead;942 char *buffer;943 xfs_daddr_t first_bad;944 int error = 0;945 bool wrapped;946 xfs_daddr_t tmp_tail;947 xfs_daddr_t orig_tail = *tail_blk;948 949 buffer = xlog_alloc_buffer(log, 1);950 if (!buffer)951 return -ENOMEM;952 953 /*954 * Make sure the tail points to a record (returns positive count on955 * success).956 */957 error = xlog_seek_logrec_hdr(log, head_blk, *tail_blk, 1, buffer,958 &tmp_tail, &thead, &wrapped);959 if (error < 0)960 goto out;961 if (*tail_blk != tmp_tail)962 *tail_blk = tmp_tail;963 964 /*965 * Run a CRC check from the tail to the head. We can't just check966 * MAX_ICLOGS records past the tail because the tail may point to stale967 * blocks cleared during the search for the head/tail. These blocks are968 * overwritten with zero-length records and thus record count is not a969 * reliable indicator of the iclog state before a crash.970 */971 first_bad = 0;972 error = xlog_do_recovery_pass(log, head_blk, *tail_blk,973 XLOG_RECOVER_CRCPASS, &first_bad);974 while ((error == -EFSBADCRC || error == -EFSCORRUPTED) && first_bad) {975 int tail_distance;976 977 /*978 * Is corruption within range of the head? If so, retry from979 * the next record. Otherwise return an error.980 */981 tail_distance = xlog_tail_distance(log, head_blk, first_bad);982 if (tail_distance > BTOBB(XLOG_MAX_ICLOGS * hsize))983 break;984 985 /* skip to the next record; returns positive count on success */986 error = xlog_seek_logrec_hdr(log, head_blk, first_bad, 2,987 buffer, &tmp_tail, &thead, &wrapped);988 if (error < 0)989 goto out;990 991 *tail_blk = tmp_tail;992 first_bad = 0;993 error = xlog_do_recovery_pass(log, head_blk, *tail_blk,994 XLOG_RECOVER_CRCPASS, &first_bad);995 }996 997 if (!error && *tail_blk != orig_tail)998 xfs_warn(log->l_mp,999 "Tail block (0x%llx) overwrite detected. Updated to 0x%llx",1000 orig_tail, *tail_blk);1001out:1002 kvfree(buffer);1003 return error;1004}1005 1006/*1007 * Detect and trim torn writes from the head of the log.1008 *1009 * Storage without sector atomicity guarantees can result in torn writes in the1010 * log in the event of a crash. Our only means to detect this scenario is via1011 * CRC verification. While we can't always be certain that CRC verification1012 * failure is due to a torn write vs. an unrelated corruption, we do know that1013 * only a certain number (XLOG_MAX_ICLOGS) of log records can be written out at1014 * one time. Therefore, CRC verify up to XLOG_MAX_ICLOGS records at the head of1015 * the log and treat failures in this range as torn writes as a matter of1016 * policy. In the event of CRC failure, the head is walked back to the last good1017 * record in the log and the tail is updated from that record and verified.1018 */1019STATIC int1020xlog_verify_head(1021 struct xlog *log,1022 xfs_daddr_t *head_blk, /* in/out: unverified head */1023 xfs_daddr_t *tail_blk, /* out: tail block */1024 char *buffer,1025 xfs_daddr_t *rhead_blk, /* start blk of last record */1026 struct xlog_rec_header **rhead, /* ptr to last record */1027 bool *wrapped) /* last rec. wraps phys. log */1028{1029 struct xlog_rec_header *tmp_rhead;1030 char *tmp_buffer;1031 xfs_daddr_t first_bad;1032 xfs_daddr_t tmp_rhead_blk;1033 int found;1034 int error;1035 bool tmp_wrapped;1036 1037 /*1038 * Check the head of the log for torn writes. Search backwards from the1039 * head until we hit the tail or the maximum number of log record I/Os1040 * that could have been in flight at one time. Use a temporary buffer so1041 * we don't trash the rhead/buffer pointers from the caller.1042 */1043 tmp_buffer = xlog_alloc_buffer(log, 1);1044 if (!tmp_buffer)1045 return -ENOMEM;1046 error = xlog_rseek_logrec_hdr(log, *head_blk, *tail_blk,1047 XLOG_MAX_ICLOGS, tmp_buffer,1048 &tmp_rhead_blk, &tmp_rhead, &tmp_wrapped);1049 kvfree(tmp_buffer);1050 if (error < 0)1051 return error;1052 1053 /*1054 * Now run a CRC verification pass over the records starting at the1055 * block found above to the current head. If a CRC failure occurs, the1056 * log block of the first bad record is saved in first_bad.1057 */1058 error = xlog_do_recovery_pass(log, *head_blk, tmp_rhead_blk,1059 XLOG_RECOVER_CRCPASS, &first_bad);1060 if ((error == -EFSBADCRC || error == -EFSCORRUPTED) && first_bad) {1061 /*1062 * We've hit a potential torn write. Reset the error and warn1063 * about it.1064 */1065 error = 0;1066 xfs_warn(log->l_mp,1067"Torn write (CRC failure) detected at log block 0x%llx. Truncating head block from 0x%llx.",1068 first_bad, *head_blk);1069 1070 /*1071 * Get the header block and buffer pointer for the last good1072 * record before the bad record.1073 *1074 * Note that xlog_find_tail() clears the blocks at the new head1075 * (i.e., the records with invalid CRC) if the cycle number1076 * matches the current cycle.1077 */1078 found = xlog_rseek_logrec_hdr(log, first_bad, *tail_blk, 1,1079 buffer, rhead_blk, rhead, wrapped);1080 if (found < 0)1081 return found;1082 if (found == 0) /* XXX: right thing to do here? */1083 return -EIO;1084 1085 /*1086 * Reset the head block to the starting block of the first bad1087 * log record and set the tail block based on the last good1088 * record.1089 *1090 * Bail out if the updated head/tail match as this indicates1091 * possible corruption outside of the acceptable1092 * (XLOG_MAX_ICLOGS) range. This is a job for xfs_repair...1093 */1094 *head_blk = first_bad;1095 *tail_blk = BLOCK_LSN(be64_to_cpu((*rhead)->h_tail_lsn));1096 if (*head_blk == *tail_blk) {1097 ASSERT(0);1098 return 0;1099 }1100 }1101 if (error)1102 return error;1103 1104 return xlog_verify_tail(log, *head_blk, tail_blk,1105 be32_to_cpu((*rhead)->h_size));1106}1107 1108/*1109 * We need to make sure we handle log wrapping properly, so we can't use the1110 * calculated logbno directly. Make sure it wraps to the correct bno inside the1111 * log.1112 *1113 * The log is limited to 32 bit sizes, so we use the appropriate modulus1114 * operation here and cast it back to a 64 bit daddr on return.1115 */1116static inline xfs_daddr_t1117xlog_wrap_logbno(1118 struct xlog *log,1119 xfs_daddr_t bno)1120{1121 int mod;1122 1123 div_s64_rem(bno, log->l_logBBsize, &mod);1124 return mod;1125}1126 1127/*1128 * Check whether the head of the log points to an unmount record. In other1129 * words, determine whether the log is clean. If so, update the in-core state1130 * appropriately.1131 */1132static int1133xlog_check_unmount_rec(1134 struct xlog *log,1135 xfs_daddr_t *head_blk,1136 xfs_daddr_t *tail_blk,1137 struct xlog_rec_header *rhead,1138 xfs_daddr_t rhead_blk,1139 char *buffer,1140 bool *clean)1141{1142 struct xlog_op_header *op_head;1143 xfs_daddr_t umount_data_blk;1144 xfs_daddr_t after_umount_blk;1145 int hblks;1146 int error;1147 char *offset;1148 1149 *clean = false;1150 1151 /*1152 * Look for unmount record. If we find it, then we know there was a1153 * clean unmount. Since 'i' could be the last block in the physical1154 * log, we convert to a log block before comparing to the head_blk.1155 *1156 * Save the current tail lsn to use to pass to xlog_clear_stale_blocks()1157 * below. We won't want to clear the unmount record if there is one, so1158 * we pass the lsn of the unmount record rather than the block after it.1159 */1160 hblks = xlog_logrec_hblks(log, rhead);1161 after_umount_blk = xlog_wrap_logbno(log,1162 rhead_blk + hblks + BTOBB(be32_to_cpu(rhead->h_len)));1163 1164 if (*head_blk == after_umount_blk &&1165 be32_to_cpu(rhead->h_num_logops) == 1) {1166 umount_data_blk = xlog_wrap_logbno(log, rhead_blk + hblks);1167 error = xlog_bread(log, umount_data_blk, 1, buffer, &offset);1168 if (error)1169 return error;1170 1171 op_head = (struct xlog_op_header *)offset;1172 if (op_head->oh_flags & XLOG_UNMOUNT_TRANS) {1173 /*1174 * Set tail and last sync so that newly written log1175 * records will point recovery to after the current1176 * unmount record.1177 */1178 xlog_assign_atomic_lsn(&log->l_tail_lsn,1179 log->l_curr_cycle, after_umount_blk);1180 log->l_ailp->ail_head_lsn =1181 atomic64_read(&log->l_tail_lsn);1182 *tail_blk = after_umount_blk;1183 1184 *clean = true;1185 }1186 }1187 1188 return 0;1189}1190 1191static void1192xlog_set_state(1193 struct xlog *log,1194 xfs_daddr_t head_blk,1195 struct xlog_rec_header *rhead,1196 xfs_daddr_t rhead_blk,1197 bool bump_cycle)1198{1199 /*1200 * Reset log values according to the state of the log when we1201 * crashed. In the case where head_blk == 0, we bump curr_cycle1202 * one because the next write starts a new cycle rather than1203 * continuing the cycle of the last good log record. At this1204 * point we have guaranteed that all partial log records have been1205 * accounted for. Therefore, we know that the last good log record1206 * written was complete and ended exactly on the end boundary1207 * of the physical log.1208 */1209 log->l_prev_block = rhead_blk;1210 log->l_curr_block = (int)head_blk;1211 log->l_curr_cycle = be32_to_cpu(rhead->h_cycle);1212 if (bump_cycle)1213 log->l_curr_cycle++;1214 atomic64_set(&log->l_tail_lsn, be64_to_cpu(rhead->h_tail_lsn));1215 log->l_ailp->ail_head_lsn = be64_to_cpu(rhead->h_lsn);1216}1217 1218/*1219 * Find the sync block number or the tail of the log.1220 *1221 * This will be the block number of the last record to have its1222 * associated buffers synced to disk. Every log record header has1223 * a sync lsn embedded in it. LSNs hold block numbers, so it is easy1224 * to get a sync block number. The only concern is to figure out which1225 * log record header to believe.1226 *1227 * The following algorithm uses the log record header with the largest1228 * lsn. The entire log record does not need to be valid. We only care1229 * that the header is valid.1230 *1231 * We could speed up search by using current head_blk buffer, but it is not1232 * available.1233 */1234STATIC int1235xlog_find_tail(1236 struct xlog *log,1237 xfs_daddr_t *head_blk,1238 xfs_daddr_t *tail_blk)1239{1240 xlog_rec_header_t *rhead;1241 char *offset = NULL;1242 char *buffer;1243 int error;1244 xfs_daddr_t rhead_blk;1245 xfs_lsn_t tail_lsn;1246 bool wrapped = false;1247 bool clean = false;1248 1249 /*1250 * Find previous log record1251 */1252 if ((error = xlog_find_head(log, head_blk)))1253 return error;1254 ASSERT(*head_blk < INT_MAX);1255 1256 buffer = xlog_alloc_buffer(log, 1);1257 if (!buffer)1258 return -ENOMEM;1259 if (*head_blk == 0) { /* special case */1260 error = xlog_bread(log, 0, 1, buffer, &offset);1261 if (error)1262 goto done;1263 1264 if (xlog_get_cycle(offset) == 0) {1265 *tail_blk = 0;1266 /* leave all other log inited values alone */1267 goto done;1268 }1269 }1270 1271 /*1272 * Search backwards through the log looking for the log record header1273 * block. This wraps all the way back around to the head so something is1274 * seriously wrong if we can't find it.1275 */1276 error = xlog_rseek_logrec_hdr(log, *head_blk, *head_blk, 1, buffer,1277 &rhead_blk, &rhead, &wrapped);1278 if (error < 0)1279 goto done;1280 if (!error) {1281 xfs_warn(log->l_mp, "%s: couldn't find sync record", __func__);1282 error = -EFSCORRUPTED;1283 goto done;1284 }1285 *tail_blk = BLOCK_LSN(be64_to_cpu(rhead->h_tail_lsn));1286 1287 /*1288 * Set the log state based on the current head record.1289 */1290 xlog_set_state(log, *head_blk, rhead, rhead_blk, wrapped);1291 tail_lsn = atomic64_read(&log->l_tail_lsn);1292 1293 /*1294 * Look for an unmount record at the head of the log. This sets the log1295 * state to determine whether recovery is necessary.1296 */1297 error = xlog_check_unmount_rec(log, head_blk, tail_blk, rhead,1298 rhead_blk, buffer, &clean);1299 if (error)1300 goto done;1301 1302 /*1303 * Verify the log head if the log is not clean (e.g., we have anything1304 * but an unmount record at the head). This uses CRC verification to1305 * detect and trim torn writes. If discovered, CRC failures are1306 * considered torn writes and the log head is trimmed accordingly.1307 *1308 * Note that we can only run CRC verification when the log is dirty1309 * because there's no guarantee that the log data behind an unmount1310 * record is compatible with the current architecture.1311 */1312 if (!clean) {1313 xfs_daddr_t orig_head = *head_blk;1314 1315 error = xlog_verify_head(log, head_blk, tail_blk, buffer,1316 &rhead_blk, &rhead, &wrapped);1317 if (error)1318 goto done;1319 1320 /* update in-core state again if the head changed */1321 if (*head_blk != orig_head) {1322 xlog_set_state(log, *head_blk, rhead, rhead_blk,1323 wrapped);1324 tail_lsn = atomic64_read(&log->l_tail_lsn);1325 error = xlog_check_unmount_rec(log, head_blk, tail_blk,1326 rhead, rhead_blk, buffer,1327 &clean);1328 if (error)1329 goto done;1330 }1331 }1332 1333 /*1334 * Note that the unmount was clean. If the unmount was not clean, we1335 * need to know this to rebuild the superblock counters from the perag1336 * headers if we have a filesystem using non-persistent counters.1337 */1338 if (clean)1339 xfs_set_clean(log->l_mp);1340 1341 /*1342 * Make sure that there are no blocks in front of the head1343 * with the same cycle number as the head. This can happen1344 * because we allow multiple outstanding log writes concurrently,1345 * and the later writes might make it out before earlier ones.1346 *1347 * We use the lsn from before modifying it so that we'll never1348 * overwrite the unmount record after a clean unmount.1349 *1350 * Do this only if we are going to recover the filesystem1351 *1352 * NOTE: This used to say "if (!readonly)"1353 * However on Linux, we can & do recover a read-only filesystem.1354 * We only skip recovery if NORECOVERY is specified on mount,1355 * in which case we would not be here.1356 *1357 * But... if the -device- itself is readonly, just skip this.1358 * We can't recover this device anyway, so it won't matter.1359 */1360 if (!xfs_readonly_buftarg(log->l_targ))1361 error = xlog_clear_stale_blocks(log, tail_lsn);1362 1363done:1364 kvfree(buffer);1365 1366 if (error)1367 xfs_warn(log->l_mp, "failed to locate log tail");1368 return error;1369}1370 1371/*1372 * Is the log zeroed at all?1373 *1374 * The last binary search should be changed to perform an X block read1375 * once X becomes small enough. You can then search linearly through1376 * the X blocks. This will cut down on the number of reads we need to do.1377 *1378 * If the log is partially zeroed, this routine will pass back the blkno1379 * of the first block with cycle number 0. It won't have a complete LR1380 * preceding it.1381 *1382 * Return:1383 * 0 => the log is completely written to1384 * 1 => use *blk_no as the first block of the log1385 * <0 => error has occurred1386 */1387STATIC int1388xlog_find_zeroed(1389 struct xlog *log,1390 xfs_daddr_t *blk_no)1391{1392 char *buffer;1393 char *offset;1394 uint first_cycle, last_cycle;1395 xfs_daddr_t new_blk, last_blk, start_blk;1396 xfs_daddr_t num_scan_bblks;1397 int error, log_bbnum = log->l_logBBsize;1398 int ret = 1;1399 1400 *blk_no = 0;1401 1402 /* check totally zeroed log */1403 buffer = xlog_alloc_buffer(log, 1);1404 if (!buffer)1405 return -ENOMEM;1406 error = xlog_bread(log, 0, 1, buffer, &offset);1407 if (error)1408 goto out_free_buffer;1409 1410 first_cycle = xlog_get_cycle(offset);1411 if (first_cycle == 0) { /* completely zeroed log */1412 *blk_no = 0;1413 goto out_free_buffer;1414 }1415 1416 /* check partially zeroed log */1417 error = xlog_bread(log, log_bbnum-1, 1, buffer, &offset);1418 if (error)1419 goto out_free_buffer;1420 1421 last_cycle = xlog_get_cycle(offset);1422 if (last_cycle != 0) { /* log completely written to */1423 ret = 0;1424 goto out_free_buffer;1425 }1426 1427 /* we have a partially zeroed log */1428 last_blk = log_bbnum-1;1429 error = xlog_find_cycle_start(log, buffer, 0, &last_blk, 0);1430 if (error)1431 goto out_free_buffer;1432 1433 /*1434 * Validate the answer. Because there is no way to guarantee that1435 * the entire log is made up of log records which are the same size,1436 * we scan over the defined maximum blocks. At this point, the maximum1437 * is not chosen to mean anything special. XXXmiken1438 */1439 num_scan_bblks = XLOG_TOTAL_REC_SHIFT(log);1440 ASSERT(num_scan_bblks <= INT_MAX);1441 1442 if (last_blk < num_scan_bblks)1443 num_scan_bblks = last_blk;1444 start_blk = last_blk - num_scan_bblks;1445 1446 /*1447 * We search for any instances of cycle number 0 that occur before1448 * our current estimate of the head. What we're trying to detect is1449 * 1 ... | 0 | 1 | 0...1450 * ^ binary search ends here1451 */1452 if ((error = xlog_find_verify_cycle(log, start_blk,1453 (int)num_scan_bblks, 0, &new_blk)))1454 goto out_free_buffer;1455 if (new_blk != -1)1456 last_blk = new_blk;1457 1458 /*1459 * Potentially backup over partial log record write. We don't need1460 * to search the end of the log because we know it is zero.1461 */1462 error = xlog_find_verify_log_record(log, start_blk, &last_blk, 0);1463 if (error == 1)1464 error = -EIO;1465 if (error)1466 goto out_free_buffer;1467 1468 *blk_no = last_blk;1469out_free_buffer:1470 kvfree(buffer);1471 if (error)1472 return error;1473 return ret;1474}1475 1476/*1477 * These are simple subroutines used by xlog_clear_stale_blocks() below1478 * to initialize a buffer full of empty log record headers and write1479 * them into the log.1480 */1481STATIC void1482xlog_add_record(1483 struct xlog *log,1484 char *buf,1485 int cycle,1486 int block,1487 int tail_cycle,1488 int tail_block)1489{1490 xlog_rec_header_t *recp = (xlog_rec_header_t *)buf;1491 1492 memset(buf, 0, BBSIZE);1493 recp->h_magicno = cpu_to_be32(XLOG_HEADER_MAGIC_NUM);1494 recp->h_cycle = cpu_to_be32(cycle);1495 recp->h_version = cpu_to_be32(1496 xfs_has_logv2(log->l_mp) ? 2 : 1);1497 recp->h_lsn = cpu_to_be64(xlog_assign_lsn(cycle, block));1498 recp->h_tail_lsn = cpu_to_be64(xlog_assign_lsn(tail_cycle, tail_block));1499 recp->h_fmt = cpu_to_be32(XLOG_FMT);1500 memcpy(&recp->h_fs_uuid, &log->l_mp->m_sb.sb_uuid, sizeof(uuid_t));1501}1502 1503STATIC int1504xlog_write_log_records(1505 struct xlog *log,1506 int cycle,1507 int start_block,1508 int blocks,1509 int tail_cycle,1510 int tail_block)1511{1512 char *offset;1513 char *buffer;1514 int balign, ealign;1515 int sectbb = log->l_sectBBsize;1516 int end_block = start_block + blocks;1517 int bufblks;1518 int error = 0;1519 int i, j = 0;1520 1521 /*1522 * Greedily allocate a buffer big enough to handle the full1523 * range of basic blocks to be written. If that fails, try1524 * a smaller size. We need to be able to write at least a1525 * log sector, or we're out of luck.1526 */1527 bufblks = roundup_pow_of_two(blocks);1528 while (bufblks > log->l_logBBsize)1529 bufblks >>= 1;1530 while (!(buffer = xlog_alloc_buffer(log, bufblks))) {1531 bufblks >>= 1;1532 if (bufblks < sectbb)1533 return -ENOMEM;1534 }1535 1536 /* We may need to do a read at the start to fill in part of1537 * the buffer in the starting sector not covered by the first1538 * write below.1539 */1540 balign = round_down(start_block, sectbb);1541 if (balign != start_block) {1542 error = xlog_bread_noalign(log, start_block, 1, buffer);1543 if (error)1544 goto out_free_buffer;1545 1546 j = start_block - balign;1547 }1548 1549 for (i = start_block; i < end_block; i += bufblks) {1550 int bcount, endcount;1551 1552 bcount = min(bufblks, end_block - start_block);1553 endcount = bcount - j;1554 1555 /* We may need to do a read at the end to fill in part of1556 * the buffer in the final sector not covered by the write.1557 * If this is the same sector as the above read, skip it.1558 */1559 ealign = round_down(end_block, sectbb);1560 if (j == 0 && (start_block + endcount > ealign)) {1561 error = xlog_bread_noalign(log, ealign, sectbb,1562 buffer + BBTOB(ealign - start_block));1563 if (error)1564 break;1565 1566 }1567 1568 offset = buffer + xlog_align(log, start_block);1569 for (; j < endcount; j++) {1570 xlog_add_record(log, offset, cycle, i+j,1571 tail_cycle, tail_block);1572 offset += BBSIZE;1573 }1574 error = xlog_bwrite(log, start_block, endcount, buffer);1575 if (error)1576 break;1577 start_block += endcount;1578 j = 0;1579 }1580 1581out_free_buffer:1582 kvfree(buffer);1583 return error;1584}1585 1586/*1587 * This routine is called to blow away any incomplete log writes out1588 * in front of the log head. We do this so that we won't become confused1589 * if we come up, write only a little bit more, and then crash again.1590 * If we leave the partial log records out there, this situation could1591 * cause us to think those partial writes are valid blocks since they1592 * have the current cycle number. We get rid of them by overwriting them1593 * with empty log records with the old cycle number rather than the1594 * current one.1595 *1596 * The tail lsn is passed in rather than taken from1597 * the log so that we will not write over the unmount record after a1598 * clean unmount in a 512 block log. Doing so would leave the log without1599 * any valid log records in it until a new one was written. If we crashed1600 * during that time we would not be able to recover.1601 */1602STATIC int1603xlog_clear_stale_blocks(1604 struct xlog *log,1605 xfs_lsn_t tail_lsn)1606{1607 int tail_cycle, head_cycle;1608 int tail_block, head_block;1609 int tail_distance, max_distance;1610 int distance;1611 int error;1612 1613 tail_cycle = CYCLE_LSN(tail_lsn);1614 tail_block = BLOCK_LSN(tail_lsn);1615 head_cycle = log->l_curr_cycle;1616 head_block = log->l_curr_block;1617 1618 /*1619 * Figure out the distance between the new head of the log1620 * and the tail. We want to write over any blocks beyond the1621 * head that we may have written just before the crash, but1622 * we don't want to overwrite the tail of the log.1623 */1624 if (head_cycle == tail_cycle) {1625 /*1626 * The tail is behind the head in the physical log,1627 * so the distance from the head to the tail is the1628 * distance from the head to the end of the log plus1629 * the distance from the beginning of the log to the1630 * tail.1631 */1632 if (XFS_IS_CORRUPT(log->l_mp,1633 head_block < tail_block ||1634 head_block >= log->l_logBBsize))1635 return -EFSCORRUPTED;1636 tail_distance = tail_block + (log->l_logBBsize - head_block);1637 } else {1638 /*1639 * The head is behind the tail in the physical log,1640 * so the distance from the head to the tail is just1641 * the tail block minus the head block.1642 */1643 if (XFS_IS_CORRUPT(log->l_mp,1644 head_block >= tail_block ||1645 head_cycle != tail_cycle + 1))1646 return -EFSCORRUPTED;1647 tail_distance = tail_block - head_block;1648 }1649 1650 /*1651 * If the head is right up against the tail, we can't clear1652 * anything.1653 */1654 if (tail_distance <= 0) {1655 ASSERT(tail_distance == 0);1656 return 0;1657 }1658 1659 max_distance = XLOG_TOTAL_REC_SHIFT(log);1660 /*1661 * Take the smaller of the maximum amount of outstanding I/O1662 * we could have and the distance to the tail to clear out.1663 * We take the smaller so that we don't overwrite the tail and1664 * we don't waste all day writing from the head to the tail1665 * for no reason.1666 */1667 max_distance = min(max_distance, tail_distance);1668 1669 if ((head_block + max_distance) <= log->l_logBBsize) {1670 /*1671 * We can stomp all the blocks we need to without1672 * wrapping around the end of the log. Just do it1673 * in a single write. Use the cycle number of the1674 * current cycle minus one so that the log will look like:1675 * n ... | n - 1 ...1676 */1677 error = xlog_write_log_records(log, (head_cycle - 1),1678 head_block, max_distance, tail_cycle,1679 tail_block);1680 if (error)1681 return error;1682 } else {1683 /*1684 * We need to wrap around the end of the physical log in1685 * order to clear all the blocks. Do it in two separate1686 * I/Os. The first write should be from the head to the1687 * end of the physical log, and it should use the current1688 * cycle number minus one just like above.1689 */1690 distance = log->l_logBBsize - head_block;1691 error = xlog_write_log_records(log, (head_cycle - 1),1692 head_block, distance, tail_cycle,1693 tail_block);1694 1695 if (error)1696 return error;1697 1698 /*1699 * Now write the blocks at the start of the physical log.1700 * This writes the remainder of the blocks we want to clear.1701 * It uses the current cycle number since we're now on the1702 * same cycle as the head so that we get:1703 * n ... n ... | n - 1 ...1704 * ^^^^^ blocks we're writing1705 */1706 distance = max_distance - (log->l_logBBsize - head_block);1707 error = xlog_write_log_records(log, head_cycle, 0, distance,1708 tail_cycle, tail_block);1709 if (error)1710 return error;1711 }1712 1713 return 0;1714}1715 1716/*1717 * Release the recovered intent item in the AIL that matches the given intent1718 * type and intent id.1719 */1720void1721xlog_recover_release_intent(1722 struct xlog *log,1723 unsigned short intent_type,1724 uint64_t intent_id)1725{1726 struct xfs_defer_pending *dfp, *n;1727 1728 list_for_each_entry_safe(dfp, n, &log->r_dfops, dfp_list) {1729 struct xfs_log_item *lip = dfp->dfp_intent;1730 1731 if (lip->li_type != intent_type)1732 continue;1733 if (!lip->li_ops->iop_match(lip, intent_id))1734 continue;1735 1736 ASSERT(xlog_item_is_intent(lip));1737 1738 xfs_defer_cancel_recovery(log->l_mp, dfp);1739 }1740}1741 1742int1743xlog_recover_iget(1744 struct xfs_mount *mp,1745 xfs_ino_t ino,1746 struct xfs_inode **ipp)1747{1748 int error;1749 1750 error = xfs_iget(mp, NULL, ino, 0, 0, ipp);1751 if (error)1752 return error;1753 1754 error = xfs_qm_dqattach(*ipp);1755 if (error) {1756 xfs_irele(*ipp);1757 return error;1758 }1759 1760 if (VFS_I(*ipp)->i_nlink == 0)1761 xfs_iflags_set(*ipp, XFS_IRECOVERY);1762 1763 return 0;1764}1765 1766/*1767 * Get an inode so that we can recover a log operation.1768 *1769 * Log intent items that target inodes effectively contain a file handle.1770 * Check that the generation number matches the intent item like we do for1771 * other file handles. Log intent items defined after this validation weakness1772 * was identified must use this function.1773 */1774int1775xlog_recover_iget_handle(1776 struct xfs_mount *mp,1777 xfs_ino_t ino,1778 uint32_t gen,1779 struct xfs_inode **ipp)1780{1781 struct xfs_inode *ip;1782 int error;1783 1784 error = xlog_recover_iget(mp, ino, &ip);1785 if (error)1786 return error;1787 1788 if (VFS_I(ip)->i_generation != gen) {1789 xfs_irele(ip);1790 return -EFSCORRUPTED;1791 }1792 1793 *ipp = ip;1794 return 0;1795}1796 1797/******************************************************************************1798 *1799 * Log recover routines1800 *1801 ******************************************************************************1802 */1803static const struct xlog_recover_item_ops *xlog_recover_item_ops[] = {1804 &xlog_buf_item_ops,1805 &xlog_inode_item_ops,1806 &xlog_dquot_item_ops,1807 &xlog_quotaoff_item_ops,1808 &xlog_icreate_item_ops,1809 &xlog_efi_item_ops,1810 &xlog_efd_item_ops,1811 &xlog_rui_item_ops,1812 &xlog_rud_item_ops,1813 &xlog_cui_item_ops,1814 &xlog_cud_item_ops,1815 &xlog_bui_item_ops,1816 &xlog_bud_item_ops,1817 &xlog_attri_item_ops,1818 &xlog_attrd_item_ops,1819 &xlog_xmi_item_ops,1820 &xlog_xmd_item_ops,1821};1822 1823static const struct xlog_recover_item_ops *1824xlog_find_item_ops(1825 struct xlog_recover_item *item)1826{1827 unsigned int i;1828 1829 for (i = 0; i < ARRAY_SIZE(xlog_recover_item_ops); i++)1830 if (ITEM_TYPE(item) == xlog_recover_item_ops[i]->item_type)1831 return xlog_recover_item_ops[i];1832 1833 return NULL;1834}1835 1836/*1837 * Sort the log items in the transaction.1838 *1839 * The ordering constraints are defined by the inode allocation and unlink1840 * behaviour. The rules are:1841 *1842 * 1. Every item is only logged once in a given transaction. Hence it1843 * represents the last logged state of the item. Hence ordering is1844 * dependent on the order in which operations need to be performed so1845 * required initial conditions are always met.1846 *1847 * 2. Cancelled buffers are recorded in pass 1 in a separate table and1848 * there's nothing to replay from them so we can simply cull them1849 * from the transaction. However, we can't do that until after we've1850 * replayed all the other items because they may be dependent on the1851 * cancelled buffer and replaying the cancelled buffer can remove it1852 * form the cancelled buffer table. Hence they have to be done last.1853 *1854 * 3. Inode allocation buffers must be replayed before inode items that1855 * read the buffer and replay changes into it. For filesystems using the1856 * ICREATE transactions, this means XFS_LI_ICREATE objects need to get1857 * treated the same as inode allocation buffers as they create and1858 * initialise the buffers directly.1859 *1860 * 4. Inode unlink buffers must be replayed after inode items are replayed.1861 * This ensures that inodes are completely flushed to the inode buffer1862 * in a "free" state before we remove the unlinked inode list pointer.1863 *1864 * Hence the ordering needs to be inode allocation buffers first, inode items1865 * second, inode unlink buffers third and cancelled buffers last.1866 *1867 * But there's a problem with that - we can't tell an inode allocation buffer1868 * apart from a regular buffer, so we can't separate them. We can, however,1869 * tell an inode unlink buffer from the others, and so we can separate them out1870 * from all the other buffers and move them to last.1871 *1872 * Hence, 4 lists, in order from head to tail:1873 * - buffer_list for all buffers except cancelled/inode unlink buffers1874 * - item_list for all non-buffer items1875 * - inode_buffer_list for inode unlink buffers1876 * - cancel_list for the cancelled buffers1877 *1878 * Note that we add objects to the tail of the lists so that first-to-last1879 * ordering is preserved within the lists. Adding objects to the head of the1880 * list means when we traverse from the head we walk them in last-to-first1881 * order. For cancelled buffers and inode unlink buffers this doesn't matter,1882 * but for all other items there may be specific ordering that we need to1883 * preserve.1884 */1885STATIC int1886xlog_recover_reorder_trans(1887 struct xlog *log,1888 struct xlog_recover *trans,1889 int pass)1890{1891 struct xlog_recover_item *item, *n;1892 int error = 0;1893 LIST_HEAD(sort_list);1894 LIST_HEAD(cancel_list);1895 LIST_HEAD(buffer_list);1896 LIST_HEAD(inode_buffer_list);1897 LIST_HEAD(item_list);1898 1899 list_splice_init(&trans->r_itemq, &sort_list);1900 list_for_each_entry_safe(item, n, &sort_list, ri_list) {1901 enum xlog_recover_reorder fate = XLOG_REORDER_ITEM_LIST;1902 1903 item->ri_ops = xlog_find_item_ops(item);1904 if (!item->ri_ops) {1905 xfs_warn(log->l_mp,1906 "%s: unrecognized type of log operation (%d)",1907 __func__, ITEM_TYPE(item));1908 ASSERT(0);1909 /*1910 * return the remaining items back to the transaction1911 * item list so they can be freed in caller.1912 */1913 if (!list_empty(&sort_list))1914 list_splice_init(&sort_list, &trans->r_itemq);1915 error = -EFSCORRUPTED;1916 break;1917 }1918 1919 if (item->ri_ops->reorder)1920 fate = item->ri_ops->reorder(item);1921 1922 switch (fate) {1923 case XLOG_REORDER_BUFFER_LIST:1924 list_move_tail(&item->ri_list, &buffer_list);1925 break;1926 case XLOG_REORDER_CANCEL_LIST:1927 trace_xfs_log_recover_item_reorder_head(log,1928 trans, item, pass);1929 list_move(&item->ri_list, &cancel_list);1930 break;1931 case XLOG_REORDER_INODE_BUFFER_LIST:1932 list_move(&item->ri_list, &inode_buffer_list);1933 break;1934 case XLOG_REORDER_ITEM_LIST:1935 trace_xfs_log_recover_item_reorder_tail(log,1936 trans, item, pass);1937 list_move_tail(&item->ri_list, &item_list);1938 break;1939 }1940 }1941 1942 ASSERT(list_empty(&sort_list));1943 if (!list_empty(&buffer_list))1944 list_splice(&buffer_list, &trans->r_itemq);1945 if (!list_empty(&item_list))1946 list_splice_tail(&item_list, &trans->r_itemq);1947 if (!list_empty(&inode_buffer_list))1948 list_splice_tail(&inode_buffer_list, &trans->r_itemq);1949 if (!list_empty(&cancel_list))1950 list_splice_tail(&cancel_list, &trans->r_itemq);1951 return error;1952}1953 1954void1955xlog_buf_readahead(1956 struct xlog *log,1957 xfs_daddr_t blkno,1958 uint len,1959 const struct xfs_buf_ops *ops)1960{1961 if (!xlog_is_buffer_cancelled(log, blkno, len))1962 xfs_buf_readahead(log->l_mp->m_ddev_targp, blkno, len, ops);1963}1964 1965/*1966 * Create a deferred work structure for resuming and tracking the progress of a1967 * log intent item that was found during recovery.1968 */1969void1970xlog_recover_intent_item(1971 struct xlog *log,1972 struct xfs_log_item *lip,1973 xfs_lsn_t lsn,1974 const struct xfs_defer_op_type *ops)1975{1976 ASSERT(xlog_item_is_intent(lip));1977 1978 xfs_defer_start_recovery(lip, &log->r_dfops, ops);1979 1980 /*1981 * Insert the intent into the AIL directly and drop one reference so1982 * that finishing or canceling the work will drop the other.1983 */1984 xfs_trans_ail_insert(log->l_ailp, lip, lsn);1985 lip->li_ops->iop_unpin(lip, 0);1986}1987 1988STATIC int1989xlog_recover_items_pass2(1990 struct xlog *log,1991 struct xlog_recover *trans,1992 struct list_head *buffer_list,1993 struct list_head *item_list)1994{1995 struct xlog_recover_item *item;1996 int error = 0;1997 1998 list_for_each_entry(item, item_list, ri_list) {1999 trace_xfs_log_recover_item_recover(log, trans, item,2000 XLOG_RECOVER_PASS2);2001 2002 if (item->ri_ops->commit_pass2)2003 error = item->ri_ops->commit_pass2(log, buffer_list,2004 item, trans->r_lsn);2005 if (error)2006 return error;2007 }2008 2009 return error;2010}2011 2012/*2013 * Perform the transaction.2014 *2015 * If the transaction modifies a buffer or inode, do it now. Otherwise,2016 * EFIs and EFDs get queued up by adding entries into the AIL for them.2017 */2018STATIC int2019xlog_recover_commit_trans(2020 struct xlog *log,2021 struct xlog_recover *trans,2022 int pass,2023 struct list_head *buffer_list)2024{2025 int error = 0;2026 int items_queued = 0;2027 struct xlog_recover_item *item;2028 struct xlog_recover_item *next;2029 LIST_HEAD (ra_list);2030 LIST_HEAD (done_list);2031 2032 #define XLOG_RECOVER_COMMIT_QUEUE_MAX 1002033 2034 hlist_del_init(&trans->r_list);2035 2036 error = xlog_recover_reorder_trans(log, trans, pass);2037 if (error)2038 return error;2039 2040 list_for_each_entry_safe(item, next, &trans->r_itemq, ri_list) {2041 trace_xfs_log_recover_item_recover(log, trans, item, pass);2042 2043 switch (pass) {2044 case XLOG_RECOVER_PASS1:2045 if (item->ri_ops->commit_pass1)2046 error = item->ri_ops->commit_pass1(log, item);2047 break;2048 case XLOG_RECOVER_PASS2:2049 if (item->ri_ops->ra_pass2)2050 item->ri_ops->ra_pass2(log, item);2051 list_move_tail(&item->ri_list, &ra_list);2052 items_queued++;2053 if (items_queued >= XLOG_RECOVER_COMMIT_QUEUE_MAX) {2054 error = xlog_recover_items_pass2(log, trans,2055 buffer_list, &ra_list);2056 list_splice_tail_init(&ra_list, &done_list);2057 items_queued = 0;2058 }2059 2060 break;2061 default:2062 ASSERT(0);2063 }2064 2065 if (error)2066 goto out;2067 }2068 2069out:2070 if (!list_empty(&ra_list)) {2071 if (!error)2072 error = xlog_recover_items_pass2(log, trans,2073 buffer_list, &ra_list);2074 list_splice_tail_init(&ra_list, &done_list);2075 }2076 2077 if (!list_empty(&done_list))2078 list_splice_init(&done_list, &trans->r_itemq);2079 2080 return error;2081}2082 2083STATIC void2084xlog_recover_add_item(2085 struct list_head *head)2086{2087 struct xlog_recover_item *item;2088 2089 item = kzalloc(sizeof(struct xlog_recover_item),2090 GFP_KERNEL | __GFP_NOFAIL);2091 INIT_LIST_HEAD(&item->ri_list);2092 list_add_tail(&item->ri_list, head);2093}2094 2095STATIC int2096xlog_recover_add_to_cont_trans(2097 struct xlog *log,2098 struct xlog_recover *trans,2099 char *dp,2100 int len)2101{2102 struct xlog_recover_item *item;2103 char *ptr, *old_ptr;2104 int old_len;2105 2106 /*2107 * If the transaction is empty, the header was split across this and the2108 * previous record. Copy the rest of the header.2109 */2110 if (list_empty(&trans->r_itemq)) {2111 ASSERT(len <= sizeof(struct xfs_trans_header));2112 if (len > sizeof(struct xfs_trans_header)) {2113 xfs_warn(log->l_mp, "%s: bad header length", __func__);2114 return -EFSCORRUPTED;2115 }2116 2117 xlog_recover_add_item(&trans->r_itemq);2118 ptr = (char *)&trans->r_theader +2119 sizeof(struct xfs_trans_header) - len;2120 memcpy(ptr, dp, len);2121 return 0;2122 }2123 2124 /* take the tail entry */2125 item = list_entry(trans->r_itemq.prev, struct xlog_recover_item,2126 ri_list);2127 2128 old_ptr = item->ri_buf[item->ri_cnt-1].i_addr;2129 old_len = item->ri_buf[item->ri_cnt-1].i_len;2130 2131 ptr = kvrealloc(old_ptr, len + old_len, GFP_KERNEL);2132 if (!ptr)2133 return -ENOMEM;2134 memcpy(&ptr[old_len], dp, len);2135 item->ri_buf[item->ri_cnt-1].i_len += len;2136 item->ri_buf[item->ri_cnt-1].i_addr = ptr;2137 trace_xfs_log_recover_item_add_cont(log, trans, item, 0);2138 return 0;2139}2140 2141/*2142 * The next region to add is the start of a new region. It could be2143 * a whole region or it could be the first part of a new region. Because2144 * of this, the assumption here is that the type and size fields of all2145 * format structures fit into the first 32 bits of the structure.2146 *2147 * This works because all regions must be 32 bit aligned. Therefore, we2148 * either have both fields or we have neither field. In the case we have2149 * neither field, the data part of the region is zero length. We only have2150 * a log_op_header and can throw away the header since a new one will appear2151 * later. If we have at least 4 bytes, then we can determine how many regions2152 * will appear in the current log item.2153 */2154STATIC int2155xlog_recover_add_to_trans(2156 struct xlog *log,2157 struct xlog_recover *trans,2158 char *dp,2159 int len)2160{2161 struct xfs_inode_log_format *in_f; /* any will do */2162 struct xlog_recover_item *item;2163 char *ptr;2164 2165 if (!len)2166 return 0;2167 if (list_empty(&trans->r_itemq)) {2168 /* we need to catch log corruptions here */2169 if (*(uint *)dp != XFS_TRANS_HEADER_MAGIC) {2170 xfs_warn(log->l_mp, "%s: bad header magic number",2171 __func__);2172 ASSERT(0);2173 return -EFSCORRUPTED;2174 }2175 2176 if (len > sizeof(struct xfs_trans_header)) {2177 xfs_warn(log->l_mp, "%s: bad header length", __func__);2178 ASSERT(0);2179 return -EFSCORRUPTED;2180 }2181 2182 /*2183 * The transaction header can be arbitrarily split across op2184 * records. If we don't have the whole thing here, copy what we2185 * do have and handle the rest in the next record.2186 */2187 if (len == sizeof(struct xfs_trans_header))2188 xlog_recover_add_item(&trans->r_itemq);2189 memcpy(&trans->r_theader, dp, len);2190 return 0;2191 }2192 2193 ptr = xlog_kvmalloc(len);2194 memcpy(ptr, dp, len);2195 in_f = (struct xfs_inode_log_format *)ptr;2196 2197 /* take the tail entry */2198 item = list_entry(trans->r_itemq.prev, struct xlog_recover_item,2199 ri_list);2200 if (item->ri_total != 0 &&2201 item->ri_total == item->ri_cnt) {2202 /* tail item is in use, get a new one */2203 xlog_recover_add_item(&trans->r_itemq);2204 item = list_entry(trans->r_itemq.prev,2205 struct xlog_recover_item, ri_list);2206 }2207 2208 if (item->ri_total == 0) { /* first region to be added */2209 if (in_f->ilf_size == 0 ||2210 in_f->ilf_size > XLOG_MAX_REGIONS_IN_ITEM) {2211 xfs_warn(log->l_mp,2212 "bad number of regions (%d) in inode log format",2213 in_f->ilf_size);2214 ASSERT(0);2215 kvfree(ptr);2216 return -EFSCORRUPTED;2217 }2218 2219 item->ri_total = in_f->ilf_size;2220 item->ri_buf = kzalloc(item->ri_total * sizeof(xfs_log_iovec_t),2221 GFP_KERNEL | __GFP_NOFAIL);2222 }2223 2224 if (item->ri_total <= item->ri_cnt) {2225 xfs_warn(log->l_mp,2226 "log item region count (%d) overflowed size (%d)",2227 item->ri_cnt, item->ri_total);2228 ASSERT(0);2229 kvfree(ptr);2230 return -EFSCORRUPTED;2231 }2232 2233 /* Description region is ri_buf[0] */2234 item->ri_buf[item->ri_cnt].i_addr = ptr;2235 item->ri_buf[item->ri_cnt].i_len = len;2236 item->ri_cnt++;2237 trace_xfs_log_recover_item_add(log, trans, item, 0);2238 return 0;2239}2240 2241/*2242 * Free up any resources allocated by the transaction2243 *2244 * Remember that EFIs, EFDs, and IUNLINKs are handled later.2245 */2246STATIC void2247xlog_recover_free_trans(2248 struct xlog_recover *trans)2249{2250 struct xlog_recover_item *item, *n;2251 int i;2252 2253 hlist_del_init(&trans->r_list);2254 2255 list_for_each_entry_safe(item, n, &trans->r_itemq, ri_list) {2256 /* Free the regions in the item. */2257 list_del(&item->ri_list);2258 for (i = 0; i < item->ri_cnt; i++)2259 kvfree(item->ri_buf[i].i_addr);2260 /* Free the item itself */2261 kfree(item->ri_buf);2262 kfree(item);2263 }2264 /* Free the transaction recover structure */2265 kfree(trans);2266}2267 2268/*2269 * On error or completion, trans is freed.2270 */2271STATIC int2272xlog_recovery_process_trans(2273 struct xlog *log,2274 struct xlog_recover *trans,2275 char *dp,2276 unsigned int len,2277 unsigned int flags,2278 int pass,2279 struct list_head *buffer_list)2280{2281 int error = 0;2282 bool freeit = false;2283 2284 /* mask off ophdr transaction container flags */2285 flags &= ~XLOG_END_TRANS;2286 if (flags & XLOG_WAS_CONT_TRANS)2287 flags &= ~XLOG_CONTINUE_TRANS;2288 2289 /*2290 * Callees must not free the trans structure. We'll decide if we need to2291 * free it or not based on the operation being done and it's result.2292 */2293 switch (flags) {2294 /* expected flag values */2295 case 0:2296 case XLOG_CONTINUE_TRANS:2297 error = xlog_recover_add_to_trans(log, trans, dp, len);2298 break;2299 case XLOG_WAS_CONT_TRANS:2300 error = xlog_recover_add_to_cont_trans(log, trans, dp, len);2301 break;2302 case XLOG_COMMIT_TRANS:2303 error = xlog_recover_commit_trans(log, trans, pass,2304 buffer_list);2305 /* success or fail, we are now done with this transaction. */2306 freeit = true;2307 break;2308 2309 /* unexpected flag values */2310 case XLOG_UNMOUNT_TRANS:2311 /* just skip trans */2312 xfs_warn(log->l_mp, "%s: Unmount LR", __func__);2313 freeit = true;2314 break;2315 case XLOG_START_TRANS:2316 default:2317 xfs_warn(log->l_mp, "%s: bad flag 0x%x", __func__, flags);2318 ASSERT(0);2319 error = -EFSCORRUPTED;2320 break;2321 }2322 if (error || freeit)2323 xlog_recover_free_trans(trans);2324 return error;2325}2326 2327/*2328 * Lookup the transaction recovery structure associated with the ID in the2329 * current ophdr. If the transaction doesn't exist and the start flag is set in2330 * the ophdr, then allocate a new transaction for future ID matches to find.2331 * Either way, return what we found during the lookup - an existing transaction2332 * or nothing.2333 */2334STATIC struct xlog_recover *2335xlog_recover_ophdr_to_trans(2336 struct hlist_head rhash[],2337 struct xlog_rec_header *rhead,2338 struct xlog_op_header *ohead)2339{2340 struct xlog_recover *trans;2341 xlog_tid_t tid;2342 struct hlist_head *rhp;2343 2344 tid = be32_to_cpu(ohead->oh_tid);2345 rhp = &rhash[XLOG_RHASH(tid)];2346 hlist_for_each_entry(trans, rhp, r_list) {2347 if (trans->r_log_tid == tid)2348 return trans;2349 }2350 2351 /*2352 * skip over non-start transaction headers - we could be2353 * processing slack space before the next transaction starts2354 */2355 if (!(ohead->oh_flags & XLOG_START_TRANS))2356 return NULL;2357 2358 ASSERT(be32_to_cpu(ohead->oh_len) == 0);2359 2360 /*2361 * This is a new transaction so allocate a new recovery container to2362 * hold the recovery ops that will follow.2363 */2364 trans = kzalloc(sizeof(struct xlog_recover), GFP_KERNEL | __GFP_NOFAIL);2365 trans->r_log_tid = tid;2366 trans->r_lsn = be64_to_cpu(rhead->h_lsn);2367 INIT_LIST_HEAD(&trans->r_itemq);2368 INIT_HLIST_NODE(&trans->r_list);2369 hlist_add_head(&trans->r_list, rhp);2370 2371 /*2372 * Nothing more to do for this ophdr. Items to be added to this new2373 * transaction will be in subsequent ophdr containers.2374 */2375 return NULL;2376}2377 2378STATIC int2379xlog_recover_process_ophdr(2380 struct xlog *log,2381 struct hlist_head rhash[],2382 struct xlog_rec_header *rhead,2383 struct xlog_op_header *ohead,2384 char *dp,2385 char *end,2386 int pass,2387 struct list_head *buffer_list)2388{2389 struct xlog_recover *trans;2390 unsigned int len;2391 int error;2392 2393 /* Do we understand who wrote this op? */2394 if (ohead->oh_clientid != XFS_TRANSACTION &&2395 ohead->oh_clientid != XFS_LOG) {2396 xfs_warn(log->l_mp, "%s: bad clientid 0x%x",2397 __func__, ohead->oh_clientid);2398 ASSERT(0);2399 return -EFSCORRUPTED;2400 }2401 2402 /*2403 * Check the ophdr contains all the data it is supposed to contain.2404 */2405 len = be32_to_cpu(ohead->oh_len);2406 if (dp + len > end) {2407 xfs_warn(log->l_mp, "%s: bad length 0x%x", __func__, len);2408 WARN_ON(1);2409 return -EFSCORRUPTED;2410 }2411 2412 trans = xlog_recover_ophdr_to_trans(rhash, rhead, ohead);2413 if (!trans) {2414 /* nothing to do, so skip over this ophdr */2415 return 0;2416 }2417 2418 /*2419 * The recovered buffer queue is drained only once we know that all2420 * recovery items for the current LSN have been processed. This is2421 * required because:2422 *2423 * - Buffer write submission updates the metadata LSN of the buffer.2424 * - Log recovery skips items with a metadata LSN >= the current LSN of2425 * the recovery item.2426 * - Separate recovery items against the same metadata buffer can share2427 * a current LSN. I.e., consider that the LSN of a recovery item is2428 * defined as the starting LSN of the first record in which its2429 * transaction appears, that a record can hold multiple transactions,2430 * and/or that a transaction can span multiple records.2431 *2432 * In other words, we are allowed to submit a buffer from log recovery2433 * once per current LSN. Otherwise, we may incorrectly skip recovery2434 * items and cause corruption.2435 *2436 * We don't know up front whether buffers are updated multiple times per2437 * LSN. Therefore, track the current LSN of each commit log record as it2438 * is processed and drain the queue when it changes. Use commit records2439 * because they are ordered correctly by the logging code.2440 */2441 if (log->l_recovery_lsn != trans->r_lsn &&2442 ohead->oh_flags & XLOG_COMMIT_TRANS) {2443 error = xfs_buf_delwri_submit(buffer_list);2444 if (error)2445 return error;2446 log->l_recovery_lsn = trans->r_lsn;2447 }2448 2449 return xlog_recovery_process_trans(log, trans, dp, len,2450 ohead->oh_flags, pass, buffer_list);2451}2452 2453/*2454 * There are two valid states of the r_state field. 0 indicates that the2455 * transaction structure is in a normal state. We have either seen the2456 * start of the transaction or the last operation we added was not a partial2457 * operation. If the last operation we added to the transaction was a2458 * partial operation, we need to mark r_state with XLOG_WAS_CONT_TRANS.2459 *2460 * NOTE: skip LRs with 0 data length.2461 */2462STATIC int2463xlog_recover_process_data(2464 struct xlog *log,2465 struct hlist_head rhash[],2466 struct xlog_rec_header *rhead,2467 char *dp,2468 int pass,2469 struct list_head *buffer_list)2470{2471 struct xlog_op_header *ohead;2472 char *end;2473 int num_logops;2474 int error;2475 2476 end = dp + be32_to_cpu(rhead->h_len);2477 num_logops = be32_to_cpu(rhead->h_num_logops);2478 2479 /* check the log format matches our own - else we can't recover */2480 if (xlog_header_check_recover(log->l_mp, rhead))2481 return -EIO;2482 2483 trace_xfs_log_recover_record(log, rhead, pass);2484 while ((dp < end) && num_logops) {2485 2486 ohead = (struct xlog_op_header *)dp;2487 dp += sizeof(*ohead);2488 if (dp > end) {2489 xfs_warn(log->l_mp, "%s: op header overrun", __func__);2490 return -EFSCORRUPTED;2491 }2492 2493 /* errors will abort recovery */2494 error = xlog_recover_process_ophdr(log, rhash, rhead, ohead,2495 dp, end, pass, buffer_list);2496 if (error)2497 return error;2498 2499 dp += be32_to_cpu(ohead->oh_len);2500 num_logops--;2501 }2502 return 0;2503}2504 2505/* Take all the collected deferred ops and finish them in order. */2506static int2507xlog_finish_defer_ops(2508 struct xfs_mount *mp,2509 struct list_head *capture_list)2510{2511 struct xfs_defer_capture *dfc, *next;2512 struct xfs_trans *tp;2513 int error = 0;2514 2515 list_for_each_entry_safe(dfc, next, capture_list, dfc_list) {2516 struct xfs_trans_res resv;2517 struct xfs_defer_resources dres;2518 2519 /*2520 * Create a new transaction reservation from the captured2521 * information. Set logcount to 1 to force the new transaction2522 * to regrant every roll so that we can make forward progress2523 * in recovery no matter how full the log might be.2524 */2525 resv.tr_logres = dfc->dfc_logres;2526 resv.tr_logcount = 1;2527 resv.tr_logflags = XFS_TRANS_PERM_LOG_RES;2528 2529 error = xfs_trans_alloc(mp, &resv, dfc->dfc_blkres,2530 dfc->dfc_rtxres, XFS_TRANS_RESERVE, &tp);2531 if (error) {2532 xlog_force_shutdown(mp->m_log, SHUTDOWN_LOG_IO_ERROR);2533 return error;2534 }2535 2536 /*2537 * Transfer to this new transaction all the dfops we captured2538 * from recovering a single intent item.2539 */2540 list_del_init(&dfc->dfc_list);2541 xfs_defer_ops_continue(dfc, tp, &dres);2542 error = xfs_trans_commit(tp);2543 xfs_defer_resources_rele(&dres);2544 if (error)2545 return error;2546 }2547 2548 ASSERT(list_empty(capture_list));2549 return 0;2550}2551 2552/* Release all the captured defer ops and capture structures in this list. */2553static void2554xlog_abort_defer_ops(2555 struct xfs_mount *mp,2556 struct list_head *capture_list)2557{2558 struct xfs_defer_capture *dfc;2559 struct xfs_defer_capture *next;2560 2561 list_for_each_entry_safe(dfc, next, capture_list, dfc_list) {2562 list_del_init(&dfc->dfc_list);2563 xfs_defer_ops_capture_abort(mp, dfc);2564 }2565}2566 2567/*2568 * When this is called, all of the log intent items which did not have2569 * corresponding log done items should be in the AIL. What we do now is update2570 * the data structures associated with each one.2571 *2572 * Since we process the log intent items in normal transactions, they will be2573 * removed at some point after the commit. This prevents us from just walking2574 * down the list processing each one. We'll use a flag in the intent item to2575 * skip those that we've already processed and use the AIL iteration mechanism's2576 * generation count to try to speed this up at least a bit.2577 *2578 * When we start, we know that the intents are the only things in the AIL. As we2579 * process them, however, other items are added to the AIL. Hence we know we2580 * have started recovery on all the pending intents when we find an non-intent2581 * item in the AIL.2582 */2583STATIC int2584xlog_recover_process_intents(2585 struct xlog *log)2586{2587 LIST_HEAD(capture_list);2588 struct xfs_defer_pending *dfp, *n;2589 int error = 0;2590#if defined(DEBUG) || defined(XFS_WARN)2591 xfs_lsn_t last_lsn;2592 2593 last_lsn = xlog_assign_lsn(log->l_curr_cycle, log->l_curr_block);2594#endif2595 2596 list_for_each_entry_safe(dfp, n, &log->r_dfops, dfp_list) {2597 ASSERT(xlog_item_is_intent(dfp->dfp_intent));2598 2599 /*2600 * We should never see a redo item with a LSN higher than2601 * the last transaction we found in the log at the start2602 * of recovery.2603 */2604 ASSERT(XFS_LSN_CMP(last_lsn, dfp->dfp_intent->li_lsn) >= 0);2605 2606 /*2607 * NOTE: If your intent processing routine can create more2608 * deferred ops, you /must/ attach them to the capture list in2609 * the recover routine or else those subsequent intents will be2610 * replayed in the wrong order!2611 *2612 * The recovery function can free the log item, so we must not2613 * access dfp->dfp_intent after it returns. It must dispose of2614 * @dfp if it returns 0.2615 */2616 error = xfs_defer_finish_recovery(log->l_mp, dfp,2617 &capture_list);2618 if (error)2619 break;2620 }2621 if (error)2622 goto err;2623 2624 error = xlog_finish_defer_ops(log->l_mp, &capture_list);2625 if (error)2626 goto err;2627 2628 return 0;2629err:2630 xlog_abort_defer_ops(log->l_mp, &capture_list);2631 return error;2632}2633 2634/*2635 * A cancel occurs when the mount has failed and we're bailing out. Release all2636 * pending log intent items that we haven't started recovery on so they don't2637 * pin the AIL.2638 */2639STATIC void2640xlog_recover_cancel_intents(2641 struct xlog *log)2642{2643 struct xfs_defer_pending *dfp, *n;2644 2645 list_for_each_entry_safe(dfp, n, &log->r_dfops, dfp_list) {2646 ASSERT(xlog_item_is_intent(dfp->dfp_intent));2647 2648 xfs_defer_cancel_recovery(log->l_mp, dfp);2649 }2650}2651 2652/*2653 * Transfer ownership of the recovered pending work to the recovery transaction2654 * and try to finish the work. If there is more work to be done, the dfp will2655 * remain attached to the transaction. If not, the dfp is freed.2656 */2657int2658xlog_recover_finish_intent(2659 struct xfs_trans *tp,2660 struct xfs_defer_pending *dfp)2661{2662 int error;2663 2664 list_move(&dfp->dfp_list, &tp->t_dfops);2665 error = xfs_defer_finish_one(tp, dfp);2666 if (error == -EAGAIN)2667 return 0;2668 return error;2669}2670 2671/*2672 * This routine performs a transaction to null out a bad inode pointer2673 * in an agi unlinked inode hash bucket.2674 */2675STATIC void2676xlog_recover_clear_agi_bucket(2677 struct xfs_perag *pag,2678 int bucket)2679{2680 struct xfs_mount *mp = pag->pag_mount;2681 struct xfs_trans *tp;2682 struct xfs_agi *agi;2683 struct xfs_buf *agibp;2684 int offset;2685 int error;2686 2687 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_clearagi, 0, 0, 0, &tp);2688 if (error)2689 goto out_error;2690 2691 error = xfs_read_agi(pag, tp, 0, &agibp);2692 if (error)2693 goto out_abort;2694 2695 agi = agibp->b_addr;2696 agi->agi_unlinked[bucket] = cpu_to_be32(NULLAGINO);2697 offset = offsetof(xfs_agi_t, agi_unlinked) +2698 (sizeof(xfs_agino_t) * bucket);2699 xfs_trans_log_buf(tp, agibp, offset,2700 (offset + sizeof(xfs_agino_t) - 1));2701 2702 error = xfs_trans_commit(tp);2703 if (error)2704 goto out_error;2705 return;2706 2707out_abort:2708 xfs_trans_cancel(tp);2709out_error:2710 xfs_warn(mp, "%s: failed to clear agi %d. Continuing.", __func__,2711 pag->pag_agno);2712 return;2713}2714 2715static int2716xlog_recover_iunlink_bucket(2717 struct xfs_perag *pag,2718 struct xfs_agi *agi,2719 int bucket)2720{2721 struct xfs_mount *mp = pag->pag_mount;2722 struct xfs_inode *prev_ip = NULL;2723 struct xfs_inode *ip;2724 xfs_agino_t prev_agino, agino;2725 int error = 0;2726 2727 agino = be32_to_cpu(agi->agi_unlinked[bucket]);2728 while (agino != NULLAGINO) {2729 error = xfs_iget(mp, NULL,2730 XFS_AGINO_TO_INO(mp, pag->pag_agno, agino),2731 0, 0, &ip);2732 if (error)2733 break;2734 2735 ASSERT(VFS_I(ip)->i_nlink == 0);2736 ASSERT(VFS_I(ip)->i_mode != 0);2737 xfs_iflags_clear(ip, XFS_IRECOVERY);2738 agino = ip->i_next_unlinked;2739 2740 if (prev_ip) {2741 ip->i_prev_unlinked = prev_agino;2742 xfs_irele(prev_ip);2743 2744 /*2745 * Ensure the inode is removed from the unlinked list2746 * before we continue so that it won't race with2747 * building the in-memory list here. This could be2748 * serialised with the agibp lock, but that just2749 * serialises via lockstepping and it's much simpler2750 * just to flush the inodegc queue and wait for it to2751 * complete.2752 */2753 error = xfs_inodegc_flush(mp);2754 if (error)2755 break;2756 }2757 2758 prev_agino = agino;2759 prev_ip = ip;2760 }2761 2762 if (prev_ip) {2763 int error2;2764 2765 ip->i_prev_unlinked = prev_agino;2766 xfs_irele(prev_ip);2767 2768 error2 = xfs_inodegc_flush(mp);2769 if (error2 && !error)2770 return error2;2771 }2772 return error;2773}2774 2775/*2776 * Recover AGI unlinked lists2777 *2778 * This is called during recovery to process any inodes which we unlinked but2779 * not freed when the system crashed. These inodes will be on the lists in the2780 * AGI blocks. What we do here is scan all the AGIs and fully truncate and free2781 * any inodes found on the lists. Each inode is removed from the lists when it2782 * has been fully truncated and is freed. The freeing of the inode and its2783 * removal from the list must be atomic.2784 *2785 * If everything we touch in the agi processing loop is already in memory, this2786 * loop can hold the cpu for a long time. It runs without lock contention,2787 * memory allocation contention, the need wait for IO, etc, and so will run2788 * until we either run out of inodes to process, run low on memory or we run out2789 * of log space.2790 *2791 * This behaviour is bad for latency on single CPU and non-preemptible kernels,2792 * and can prevent other filesystem work (such as CIL pushes) from running. This2793 * can lead to deadlocks if the recovery process runs out of log reservation2794 * space. Hence we need to yield the CPU when there is other kernel work2795 * scheduled on this CPU to ensure other scheduled work can run without undue2796 * latency.2797 */2798static void2799xlog_recover_iunlink_ag(2800 struct xfs_perag *pag)2801{2802 struct xfs_agi *agi;2803 struct xfs_buf *agibp;2804 int bucket;2805 int error;2806 2807 error = xfs_read_agi(pag, NULL, 0, &agibp);2808 if (error) {2809 /*2810 * AGI is b0rked. Don't process it.2811 *2812 * We should probably mark the filesystem as corrupt after we've2813 * recovered all the ag's we can....2814 */2815 return;2816 }2817 2818 /*2819 * Unlock the buffer so that it can be acquired in the normal course of2820 * the transaction to truncate and free each inode. Because we are not2821 * racing with anyone else here for the AGI buffer, we don't even need2822 * to hold it locked to read the initial unlinked bucket entries out of2823 * the buffer. We keep buffer reference though, so that it stays pinned2824 * in memory while we need the buffer.2825 */2826 agi = agibp->b_addr;2827 xfs_buf_unlock(agibp);2828 2829 for (bucket = 0; bucket < XFS_AGI_UNLINKED_BUCKETS; bucket++) {2830 error = xlog_recover_iunlink_bucket(pag, agi, bucket);2831 if (error) {2832 /*2833 * Bucket is unrecoverable, so only a repair scan can2834 * free the remaining unlinked inodes. Just empty the2835 * bucket and remaining inodes on it unreferenced and2836 * unfreeable.2837 */2838 xlog_recover_clear_agi_bucket(pag, bucket);2839 }2840 }2841 2842 xfs_buf_rele(agibp);2843}2844 2845static void2846xlog_recover_process_iunlinks(2847 struct xlog *log)2848{2849 struct xfs_perag *pag;2850 xfs_agnumber_t agno;2851 2852 for_each_perag(log->l_mp, agno, pag)2853 xlog_recover_iunlink_ag(pag);2854}2855 2856STATIC void2857xlog_unpack_data(2858 struct xlog_rec_header *rhead,2859 char *dp,2860 struct xlog *log)2861{2862 int i, j, k;2863 2864 for (i = 0; i < BTOBB(be32_to_cpu(rhead->h_len)) &&2865 i < (XLOG_HEADER_CYCLE_SIZE / BBSIZE); i++) {2866 *(__be32 *)dp = *(__be32 *)&rhead->h_cycle_data[i];2867 dp += BBSIZE;2868 }2869 2870 if (xfs_has_logv2(log->l_mp)) {2871 xlog_in_core_2_t *xhdr = (xlog_in_core_2_t *)rhead;2872 for ( ; i < BTOBB(be32_to_cpu(rhead->h_len)); i++) {2873 j = i / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);2874 k = i % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);2875 *(__be32 *)dp = xhdr[j].hic_xheader.xh_cycle_data[k];2876 dp += BBSIZE;2877 }2878 }2879}2880 2881/*2882 * CRC check, unpack and process a log record.2883 */2884STATIC int2885xlog_recover_process(2886 struct xlog *log,2887 struct hlist_head rhash[],2888 struct xlog_rec_header *rhead,2889 char *dp,2890 int pass,2891 struct list_head *buffer_list)2892{2893 __le32 old_crc = rhead->h_crc;2894 __le32 crc;2895 2896 crc = xlog_cksum(log, rhead, dp, be32_to_cpu(rhead->h_len));2897 2898 /*2899 * Nothing else to do if this is a CRC verification pass. Just return2900 * if this a record with a non-zero crc. Unfortunately, mkfs always2901 * sets old_crc to 0 so we must consider this valid even on v5 supers.2902 * Otherwise, return EFSBADCRC on failure so the callers up the stack2903 * know precisely what failed.2904 */2905 if (pass == XLOG_RECOVER_CRCPASS) {2906 if (old_crc && crc != old_crc)2907 return -EFSBADCRC;2908 return 0;2909 }2910 2911 /*2912 * We're in the normal recovery path. Issue a warning if and only if the2913 * CRC in the header is non-zero. This is an advisory warning and the2914 * zero CRC check prevents warnings from being emitted when upgrading2915 * the kernel from one that does not add CRCs by default.2916 */2917 if (crc != old_crc) {2918 if (old_crc || xfs_has_crc(log->l_mp)) {2919 xfs_alert(log->l_mp,2920 "log record CRC mismatch: found 0x%x, expected 0x%x.",2921 le32_to_cpu(old_crc),2922 le32_to_cpu(crc));2923 xfs_hex_dump(dp, 32);2924 }2925 2926 /*2927 * If the filesystem is CRC enabled, this mismatch becomes a2928 * fatal log corruption failure.2929 */2930 if (xfs_has_crc(log->l_mp)) {2931 XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, log->l_mp);2932 return -EFSCORRUPTED;2933 }2934 }2935 2936 xlog_unpack_data(rhead, dp, log);2937 2938 return xlog_recover_process_data(log, rhash, rhead, dp, pass,2939 buffer_list);2940}2941 2942STATIC int2943xlog_valid_rec_header(2944 struct xlog *log,2945 struct xlog_rec_header *rhead,2946 xfs_daddr_t blkno,2947 int bufsize)2948{2949 int hlen;2950 2951 if (XFS_IS_CORRUPT(log->l_mp,2952 rhead->h_magicno != cpu_to_be32(XLOG_HEADER_MAGIC_NUM)))2953 return -EFSCORRUPTED;2954 if (XFS_IS_CORRUPT(log->l_mp,2955 (!rhead->h_version ||2956 (be32_to_cpu(rhead->h_version) &2957 (~XLOG_VERSION_OKBITS))))) {2958 xfs_warn(log->l_mp, "%s: unrecognised log version (%d).",2959 __func__, be32_to_cpu(rhead->h_version));2960 return -EFSCORRUPTED;2961 }2962 2963 /*2964 * LR body must have data (or it wouldn't have been written)2965 * and h_len must not be greater than LR buffer size.2966 */2967 hlen = be32_to_cpu(rhead->h_len);2968 if (XFS_IS_CORRUPT(log->l_mp, hlen <= 0 || hlen > bufsize))2969 return -EFSCORRUPTED;2970 2971 if (XFS_IS_CORRUPT(log->l_mp,2972 blkno > log->l_logBBsize || blkno > INT_MAX))2973 return -EFSCORRUPTED;2974 return 0;2975}2976 2977/*2978 * Read the log from tail to head and process the log records found.2979 * Handle the two cases where the tail and head are in the same cycle2980 * and where the active portion of the log wraps around the end of2981 * the physical log separately. The pass parameter is passed through2982 * to the routines called to process the data and is not looked at2983 * here.2984 */2985STATIC int2986xlog_do_recovery_pass(2987 struct xlog *log,2988 xfs_daddr_t head_blk,2989 xfs_daddr_t tail_blk,2990 int pass,2991 xfs_daddr_t *first_bad) /* out: first bad log rec */2992{2993 xlog_rec_header_t *rhead;2994 xfs_daddr_t blk_no, rblk_no;2995 xfs_daddr_t rhead_blk;2996 char *offset;2997 char *hbp, *dbp;2998 int error = 0, h_size, h_len;2999 int error2 = 0;3000 int bblks, split_bblks;3001 int hblks = 1, split_hblks, wrapped_hblks;3002 int i;3003 struct hlist_head rhash[XLOG_RHASH_SIZE];3004 LIST_HEAD (buffer_list);3005 3006 ASSERT(head_blk != tail_blk);3007 blk_no = rhead_blk = tail_blk;3008 3009 for (i = 0; i < XLOG_RHASH_SIZE; i++)3010 INIT_HLIST_HEAD(&rhash[i]);3011 3012 hbp = xlog_alloc_buffer(log, hblks);3013 if (!hbp)3014 return -ENOMEM;3015 3016 /*3017 * Read the header of the tail block and get the iclog buffer size from3018 * h_size. Use this to tell how many sectors make up the log header.3019 */3020 if (xfs_has_logv2(log->l_mp)) {3021 /*3022 * When using variable length iclogs, read first sector of3023 * iclog header and extract the header size from it. Get a3024 * new hbp that is the correct size.3025 */3026 error = xlog_bread(log, tail_blk, 1, hbp, &offset);3027 if (error)3028 goto bread_err1;3029 3030 rhead = (xlog_rec_header_t *)offset;3031 3032 /*3033 * xfsprogs has a bug where record length is based on lsunit but3034 * h_size (iclog size) is hardcoded to 32k. Now that we3035 * unconditionally CRC verify the unmount record, this means the3036 * log buffer can be too small for the record and cause an3037 * overrun.3038 *3039 * Detect this condition here. Use lsunit for the buffer size as3040 * long as this looks like the mkfs case. Otherwise, return an3041 * error to avoid a buffer overrun.3042 */3043 h_size = be32_to_cpu(rhead->h_size);3044 h_len = be32_to_cpu(rhead->h_len);3045 if (h_len > h_size && h_len <= log->l_mp->m_logbsize &&3046 rhead->h_num_logops == cpu_to_be32(1)) {3047 xfs_warn(log->l_mp,3048 "invalid iclog size (%d bytes), using lsunit (%d bytes)",3049 h_size, log->l_mp->m_logbsize);3050 h_size = log->l_mp->m_logbsize;3051 }3052 3053 error = xlog_valid_rec_header(log, rhead, tail_blk, h_size);3054 if (error)3055 goto bread_err1;3056 3057 /*3058 * This open codes xlog_logrec_hblks so that we can reuse the3059 * fixed up h_size value calculated above. Without that we'd3060 * still allocate the buffer based on the incorrect on-disk3061 * size.3062 */3063 if (h_size > XLOG_HEADER_CYCLE_SIZE &&3064 (rhead->h_version & cpu_to_be32(XLOG_VERSION_2))) {3065 hblks = DIV_ROUND_UP(h_size, XLOG_HEADER_CYCLE_SIZE);3066 if (hblks > 1) {3067 kvfree(hbp);3068 hbp = xlog_alloc_buffer(log, hblks);3069 if (!hbp)3070 return -ENOMEM;3071 }3072 }3073 } else {3074 ASSERT(log->l_sectBBsize == 1);3075 h_size = XLOG_BIG_RECORD_BSIZE;3076 }3077 3078 dbp = xlog_alloc_buffer(log, BTOBB(h_size));3079 if (!dbp) {3080 kvfree(hbp);3081 return -ENOMEM;3082 }3083 3084 memset(rhash, 0, sizeof(rhash));3085 if (tail_blk > head_blk) {3086 /*3087 * Perform recovery around the end of the physical log.3088 * When the head is not on the same cycle number as the tail,3089 * we can't do a sequential recovery.3090 */3091 while (blk_no < log->l_logBBsize) {3092 /*3093 * Check for header wrapping around physical end-of-log3094 */3095 offset = hbp;3096 split_hblks = 0;3097 wrapped_hblks = 0;3098 if (blk_no + hblks <= log->l_logBBsize) {3099 /* Read header in one read */3100 error = xlog_bread(log, blk_no, hblks, hbp,3101 &offset);3102 if (error)3103 goto bread_err2;3104 } else {3105 /* This LR is split across physical log end */3106 if (blk_no != log->l_logBBsize) {3107 /* some data before physical log end */3108 ASSERT(blk_no <= INT_MAX);3109 split_hblks = log->l_logBBsize - (int)blk_no;3110 ASSERT(split_hblks > 0);3111 error = xlog_bread(log, blk_no,3112 split_hblks, hbp,3113 &offset);3114 if (error)3115 goto bread_err2;3116 }3117 3118 /*3119 * Note: this black magic still works with3120 * large sector sizes (non-512) only because:3121 * - we increased the buffer size originally3122 * by 1 sector giving us enough extra space3123 * for the second read;3124 * - the log start is guaranteed to be sector3125 * aligned;3126 * - we read the log end (LR header start)3127 * _first_, then the log start (LR header end)3128 * - order is important.3129 */3130 wrapped_hblks = hblks - split_hblks;3131 error = xlog_bread_noalign(log, 0,3132 wrapped_hblks,3133 offset + BBTOB(split_hblks));3134 if (error)3135 goto bread_err2;3136 }3137 rhead = (xlog_rec_header_t *)offset;3138 error = xlog_valid_rec_header(log, rhead,3139 split_hblks ? blk_no : 0, h_size);3140 if (error)3141 goto bread_err2;3142 3143 bblks = (int)BTOBB(be32_to_cpu(rhead->h_len));3144 blk_no += hblks;3145 3146 /*3147 * Read the log record data in multiple reads if it3148 * wraps around the end of the log. Note that if the3149 * header already wrapped, blk_no could point past the3150 * end of the log. The record data is contiguous in3151 * that case.3152 */3153 if (blk_no + bblks <= log->l_logBBsize ||3154 blk_no >= log->l_logBBsize) {3155 rblk_no = xlog_wrap_logbno(log, blk_no);3156 error = xlog_bread(log, rblk_no, bblks, dbp,3157 &offset);3158 if (error)3159 goto bread_err2;3160 } else {3161 /* This log record is split across the3162 * physical end of log */3163 offset = dbp;3164 split_bblks = 0;3165 if (blk_no != log->l_logBBsize) {3166 /* some data is before the physical3167 * end of log */3168 ASSERT(!wrapped_hblks);3169 ASSERT(blk_no <= INT_MAX);3170 split_bblks =3171 log->l_logBBsize - (int)blk_no;3172 ASSERT(split_bblks > 0);3173 error = xlog_bread(log, blk_no,3174 split_bblks, dbp,3175 &offset);3176 if (error)3177 goto bread_err2;3178 }3179 3180 /*3181 * Note: this black magic still works with3182 * large sector sizes (non-512) only because:3183 * - we increased the buffer size originally3184 * by 1 sector giving us enough extra space3185 * for the second read;3186 * - the log start is guaranteed to be sector3187 * aligned;3188 * - we read the log end (LR header start)3189 * _first_, then the log start (LR header end)3190 * - order is important.3191 */3192 error = xlog_bread_noalign(log, 0,3193 bblks - split_bblks,3194 offset + BBTOB(split_bblks));3195 if (error)3196 goto bread_err2;3197 }3198 3199 error = xlog_recover_process(log, rhash, rhead, offset,3200 pass, &buffer_list);3201 if (error)3202 goto bread_err2;3203 3204 blk_no += bblks;3205 rhead_blk = blk_no;3206 }3207 3208 ASSERT(blk_no >= log->l_logBBsize);3209 blk_no -= log->l_logBBsize;3210 rhead_blk = blk_no;3211 }3212 3213 /* read first part of physical log */3214 while (blk_no < head_blk) {3215 error = xlog_bread(log, blk_no, hblks, hbp, &offset);3216 if (error)3217 goto bread_err2;3218 3219 rhead = (xlog_rec_header_t *)offset;3220 error = xlog_valid_rec_header(log, rhead, blk_no, h_size);3221 if (error)3222 goto bread_err2;3223 3224 /* blocks in data section */3225 bblks = (int)BTOBB(be32_to_cpu(rhead->h_len));3226 error = xlog_bread(log, blk_no+hblks, bblks, dbp,3227 &offset);3228 if (error)3229 goto bread_err2;3230 3231 error = xlog_recover_process(log, rhash, rhead, offset, pass,3232 &buffer_list);3233 if (error)3234 goto bread_err2;3235 3236 blk_no += bblks + hblks;3237 rhead_blk = blk_no;3238 }3239 3240 bread_err2:3241 kvfree(dbp);3242 bread_err1:3243 kvfree(hbp);3244 3245 /*3246 * Submit buffers that have been dirtied by the last record recovered.3247 */3248 if (!list_empty(&buffer_list)) {3249 if (error) {3250 /*3251 * If there has been an item recovery error then we3252 * cannot allow partial checkpoint writeback to3253 * occur. We might have multiple checkpoints with the3254 * same start LSN in this buffer list, and partial3255 * writeback of a checkpoint in this situation can3256 * prevent future recovery of all the changes in the3257 * checkpoints at this start LSN.3258 *3259 * Note: Shutting down the filesystem will result in the3260 * delwri submission marking all the buffers stale,3261 * completing them and cleaning up _XBF_LOGRECOVERY3262 * state without doing any IO.3263 */3264 xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR);3265 }3266 error2 = xfs_buf_delwri_submit(&buffer_list);3267 }3268 3269 if (error && first_bad)3270 *first_bad = rhead_blk;3271 3272 /*3273 * Transactions are freed at commit time but transactions without commit3274 * records on disk are never committed. Free any that may be left in the3275 * hash table.3276 */3277 for (i = 0; i < XLOG_RHASH_SIZE; i++) {3278 struct hlist_node *tmp;3279 struct xlog_recover *trans;3280 3281 hlist_for_each_entry_safe(trans, tmp, &rhash[i], r_list)3282 xlog_recover_free_trans(trans);3283 }3284 3285 return error ? error : error2;3286}3287 3288/*3289 * Do the recovery of the log. We actually do this in two phases.3290 * The two passes are necessary in order to implement the function3291 * of cancelling a record written into the log. The first pass3292 * determines those things which have been cancelled, and the3293 * second pass replays log items normally except for those which3294 * have been cancelled. The handling of the replay and cancellations3295 * takes place in the log item type specific routines.3296 *3297 * The table of items which have cancel records in the log is allocated3298 * and freed at this level, since only here do we know when all of3299 * the log recovery has been completed.3300 */3301STATIC int3302xlog_do_log_recovery(3303 struct xlog *log,3304 xfs_daddr_t head_blk,3305 xfs_daddr_t tail_blk)3306{3307 int error;3308 3309 ASSERT(head_blk != tail_blk);3310 3311 /*3312 * First do a pass to find all of the cancelled buf log items.3313 * Store them in the buf_cancel_table for use in the second pass.3314 */3315 error = xlog_alloc_buf_cancel_table(log);3316 if (error)3317 return error;3318 3319 error = xlog_do_recovery_pass(log, head_blk, tail_blk,3320 XLOG_RECOVER_PASS1, NULL);3321 if (error != 0)3322 goto out_cancel;3323 3324 /*3325 * Then do a second pass to actually recover the items in the log.3326 * When it is complete free the table of buf cancel items.3327 */3328 error = xlog_do_recovery_pass(log, head_blk, tail_blk,3329 XLOG_RECOVER_PASS2, NULL);3330 if (!error)3331 xlog_check_buf_cancel_table(log);3332out_cancel:3333 xlog_free_buf_cancel_table(log);3334 return error;3335}3336 3337/*3338 * Do the actual recovery3339 */3340STATIC int3341xlog_do_recover(3342 struct xlog *log,3343 xfs_daddr_t head_blk,3344 xfs_daddr_t tail_blk)3345{3346 struct xfs_mount *mp = log->l_mp;3347 struct xfs_buf *bp = mp->m_sb_bp;3348 struct xfs_sb *sbp = &mp->m_sb;3349 int error;3350 3351 trace_xfs_log_recover(log, head_blk, tail_blk);3352 3353 /*3354 * First replay the images in the log.3355 */3356 error = xlog_do_log_recovery(log, head_blk, tail_blk);3357 if (error)3358 return error;3359 3360 if (xlog_is_shutdown(log))3361 return -EIO;3362 3363 /*3364 * We now update the tail_lsn since much of the recovery has completed3365 * and there may be space available to use. If there were no extent or3366 * iunlinks, we can free up the entire log. This was set in3367 * xlog_find_tail to be the lsn of the last known good LR on disk. If3368 * there are extent frees or iunlinks they will have some entries in the3369 * AIL; so we look at the AIL to determine how to set the tail_lsn.3370 */3371 xfs_ail_assign_tail_lsn(log->l_ailp);3372 3373 /*3374 * Now that we've finished replaying all buffer and inode updates,3375 * re-read the superblock and reverify it.3376 */3377 xfs_buf_lock(bp);3378 xfs_buf_hold(bp);3379 error = _xfs_buf_read(bp, XBF_READ);3380 if (error) {3381 if (!xlog_is_shutdown(log)) {3382 xfs_buf_ioerror_alert(bp, __this_address);3383 ASSERT(0);3384 }3385 xfs_buf_relse(bp);3386 return error;3387 }3388 3389 /* Convert superblock from on-disk format */3390 xfs_sb_from_disk(sbp, bp->b_addr);3391 xfs_buf_relse(bp);3392 3393 /* re-initialise in-core superblock and geometry structures */3394 mp->m_features |= xfs_sb_version_to_features(sbp);3395 xfs_reinit_percpu_counters(mp);3396 3397 /* Normal transactions can now occur */3398 clear_bit(XLOG_ACTIVE_RECOVERY, &log->l_opstate);3399 return 0;3400}3401 3402/*3403 * Perform recovery and re-initialize some log variables in xlog_find_tail.3404 *3405 * Return error or zero.3406 */3407int3408xlog_recover(3409 struct xlog *log)3410{3411 xfs_daddr_t head_blk, tail_blk;3412 int error;3413 3414 /* find the tail of the log */3415 error = xlog_find_tail(log, &head_blk, &tail_blk);3416 if (error)3417 return error;3418 3419 /*3420 * The superblock was read before the log was available and thus the LSN3421 * could not be verified. Check the superblock LSN against the current3422 * LSN now that it's known.3423 */3424 if (xfs_has_crc(log->l_mp) &&3425 !xfs_log_check_lsn(log->l_mp, log->l_mp->m_sb.sb_lsn))3426 return -EINVAL;3427 3428 if (tail_blk != head_blk) {3429 /* There used to be a comment here:3430 *3431 * disallow recovery on read-only mounts. note -- mount3432 * checks for ENOSPC and turns it into an intelligent3433 * error message.3434 * ...but this is no longer true. Now, unless you specify3435 * NORECOVERY (in which case this function would never be3436 * called), we just go ahead and recover. We do this all3437 * under the vfs layer, so we can get away with it unless3438 * the device itself is read-only, in which case we fail.3439 */3440 if ((error = xfs_dev_is_read_only(log->l_mp, "recovery"))) {3441 return error;3442 }3443 3444 /*3445 * Version 5 superblock log feature mask validation. We know the3446 * log is dirty so check if there are any unknown log features3447 * in what we need to recover. If there are unknown features3448 * (e.g. unsupported transactions, then simply reject the3449 * attempt at recovery before touching anything.3450 */3451 if (xfs_sb_is_v5(&log->l_mp->m_sb) &&3452 xfs_sb_has_incompat_log_feature(&log->l_mp->m_sb,3453 XFS_SB_FEAT_INCOMPAT_LOG_UNKNOWN)) {3454 xfs_warn(log->l_mp,3455"Superblock has unknown incompatible log features (0x%x) enabled.",3456 (log->l_mp->m_sb.sb_features_log_incompat &3457 XFS_SB_FEAT_INCOMPAT_LOG_UNKNOWN));3458 xfs_warn(log->l_mp,3459"The log can not be fully and/or safely recovered by this kernel.");3460 xfs_warn(log->l_mp,3461"Please recover the log on a kernel that supports the unknown features.");3462 return -EINVAL;3463 }3464 3465 /*3466 * Delay log recovery if the debug hook is set. This is debug3467 * instrumentation to coordinate simulation of I/O failures with3468 * log recovery.3469 */3470 if (xfs_globals.log_recovery_delay) {3471 xfs_notice(log->l_mp,3472 "Delaying log recovery for %d seconds.",3473 xfs_globals.log_recovery_delay);3474 msleep(xfs_globals.log_recovery_delay * 1000);3475 }3476 3477 xfs_notice(log->l_mp, "Starting recovery (logdev: %s)",3478 log->l_mp->m_logname ? log->l_mp->m_logname3479 : "internal");3480 3481 error = xlog_do_recover(log, head_blk, tail_blk);3482 set_bit(XLOG_RECOVERY_NEEDED, &log->l_opstate);3483 }3484 return error;3485}3486 3487/*3488 * In the first part of recovery we replay inodes and buffers and build up the3489 * list of intents which need to be processed. Here we process the intents and3490 * clean up the on disk unlinked inode lists. This is separated from the first3491 * part of recovery so that the root and real-time bitmap inodes can be read in3492 * from disk in between the two stages. This is necessary so that we can free3493 * space in the real-time portion of the file system.3494 *3495 * We run this whole process under GFP_NOFS allocation context. We do a3496 * combination of non-transactional and transactional work, yet we really don't3497 * want to recurse into the filesystem from direct reclaim during any of this3498 * processing. This allows all the recovery code run here not to care about the3499 * memory allocation context it is running in.3500 */3501int3502xlog_recover_finish(3503 struct xlog *log)3504{3505 unsigned int nofs_flags = memalloc_nofs_save();3506 int error;3507 3508 error = xlog_recover_process_intents(log);3509 if (error) {3510 /*3511 * Cancel all the unprocessed intent items now so that we don't3512 * leave them pinned in the AIL. This can cause the AIL to3513 * livelock on the pinned item if anyone tries to push the AIL3514 * (inode reclaim does this) before we get around to3515 * xfs_log_mount_cancel.3516 */3517 xlog_recover_cancel_intents(log);3518 xfs_alert(log->l_mp, "Failed to recover intents");3519 xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR);3520 goto out_error;3521 }3522 3523 /*3524 * Sync the log to get all the intents out of the AIL. This isn't3525 * absolutely necessary, but it helps in case the unlink transactions3526 * would have problems pushing the intents out of the way.3527 */3528 xfs_log_force(log->l_mp, XFS_LOG_SYNC);3529 3530 xlog_recover_process_iunlinks(log);3531 3532 /*3533 * Recover any CoW staging blocks that are still referenced by the3534 * ondisk refcount metadata. During mount there cannot be any live3535 * staging extents as we have not permitted any user modifications.3536 * Therefore, it is safe to free them all right now, even on a3537 * read-only mount.3538 */3539 error = xfs_reflink_recover_cow(log->l_mp);3540 if (error) {3541 xfs_alert(log->l_mp,3542 "Failed to recover leftover CoW staging extents, err %d.",3543 error);3544 /*3545 * If we get an error here, make sure the log is shut down3546 * but return zero so that any log items committed since the3547 * end of intents processing can be pushed through the CIL3548 * and AIL.3549 */3550 xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR);3551 error = 0;3552 goto out_error;3553 }3554 3555out_error:3556 memalloc_nofs_restore(nofs_flags);3557 return error;3558}3559 3560void3561xlog_recover_cancel(3562 struct xlog *log)3563{3564 if (xlog_recovery_needed(log))3565 xlog_recover_cancel_intents(log);3566}3567 3568