1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (c) 2000-2006 Silicon Graphics, Inc.
8 #include "xfs_shared.h"
9 #include "xfs_format.h"
10 #include "xfs_log_format.h"
11 #include "xfs_trans_resv.h"
14 #include "xfs_mount.h"
15 #include "xfs_defer.h"
16 #include "xfs_inode.h"
17 #include "xfs_trans.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"
29 #include "xfs_quota.h"
30 #include "xfs_reflink.h"
32 #define BLK_AVG(blk1, blk2) ((blk1+blk2) >> 1)
39 xlog_clear_stale_blocks(
43 xlog_do_recovery_pass(
44 struct xlog *, xfs_daddr_t, xfs_daddr_t, int, xfs_daddr_t *);
47 * Sector aligned buffer routines for buffer create/read/write/access
51 * Verify the log-relative block number and length in basic blocks are valid for
52 * an operation involving the given XFS log buffer. Returns true if the fields
53 * are valid, false otherwise.
61 if (blk_no < 0 || blk_no >= log->l_logBBsize)
63 if (bbcount <= 0 || (blk_no + bbcount) > log->l_logBBsize)
69 * Allocate a buffer to hold log data. The buffer needs to be able to map to
70 * a range of nbblks basic blocks at any valid offset within the log.
78 * Pass log block 0 since we don't have an addr yet, buffer will be
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",
88 * We do log I/O in units of log sectors (a power-of-2 multiple of the
89 * basic block size), so we round up the requested size to accommodate
90 * the basic blocks required for complete log sectors.
92 * In addition, the buffer may be used for a non-sector-aligned block
93 * offset, in which case an I/O of the requested size could extend
94 * beyond the end of the buffer. If the requested size is only 1 basic
95 * block it will never straddle a sector boundary, so this won't be an
96 * issue. Nor will this be a problem if the log I/O is done in basic
97 * blocks (sector size 1). But otherwise we extend the buffer by one
98 * extra log sector to ensure there's space to accommodate this
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);
108 * Return the address of the start of the given block number's data
109 * in a log buffer. The buffer covers a log sector-aligned region.
111 static inline unsigned int
116 return BBTOB(blk_no & ((xfs_daddr_t)log->l_sectBBsize - 1));
129 if (XFS_IS_CORRUPT(log->l_mp, !xlog_verify_bno(log, blk_no, nbblks))) {
131 "Invalid log block/length (0x%llx, 0x%x) for buffer",
133 return -EFSCORRUPTED;
136 blk_no = round_down(blk_no, log->l_sectBBsize);
137 nbblks = round_up(nbblks, log->l_sectBBsize);
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)) {
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);
158 return xlog_do_io(log, blk_no, nbblks, data, REQ_OP_READ);
171 error = xlog_do_io(log, blk_no, nbblks, data, REQ_OP_READ);
173 *offset = data + xlog_align(log, blk_no);
184 return xlog_do_io(log, blk_no, nbblks, data, REQ_OP_WRITE);
189 * dump debug superblock and log record information
192 xlog_header_check_dump(
194 xlog_rec_header_t *head)
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));
202 #define xlog_header_check_dump(mp, head)
206 * check log record header for recovery
209 xlog_header_check_recover(
211 xlog_rec_header_t *head)
213 ASSERT(head->h_magicno == cpu_to_be32(XLOG_HEADER_MAGIC_NUM));
216 * IRIX doesn't write the h_fmt field and leaves it zeroed
217 * (XLOG_FMT_UNKNOWN). This stops us from trying to recover
218 * a dirty log created in IRIX.
220 if (XFS_IS_CORRUPT(mp, head->h_fmt != cpu_to_be32(XLOG_FMT))) {
222 "dirty log written in incompatible format - can't recover");
223 xlog_header_check_dump(mp, head);
224 return -EFSCORRUPTED;
226 if (XFS_IS_CORRUPT(mp, !uuid_equal(&mp->m_sb.sb_uuid,
227 &head->h_fs_uuid))) {
229 "dirty log entry has mismatched uuid - can't recover");
230 xlog_header_check_dump(mp, head);
231 return -EFSCORRUPTED;
237 * read the head block of the log and check the header
240 xlog_header_check_mount(
242 xlog_rec_header_t *head)
244 ASSERT(head->h_magicno == cpu_to_be32(XLOG_HEADER_MAGIC_NUM));
246 if (uuid_is_null(&head->h_fs_uuid)) {
248 * IRIX doesn't write the h_fs_uuid or h_fmt fields. If
249 * h_fs_uuid is null, we assume this log was last mounted
250 * by IRIX and continue.
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;
263 * This routine finds (to an approximation) the first block in the physical
264 * 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 not
266 * necessarily be perfect.
269 xlog_find_cycle_start(
272 xfs_daddr_t first_blk,
273 xfs_daddr_t *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);
288 mid_cycle = xlog_get_cycle(offset);
289 if (mid_cycle == cycle)
290 end_blk = mid_blk; /* last_half_cycle == mid_cycle */
292 first_blk = mid_blk; /* first_half_cycle == mid_cycle */
293 mid_blk = BLK_AVG(first_blk, end_blk);
295 ASSERT((mid_blk == first_blk && mid_blk+1 == end_blk) ||
296 (mid_blk == end_blk && mid_blk-1 == first_blk));
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 is
306 * found, or with -1 (an invalid block number) if there is no such
307 * block in the range. The scan needs to occur from front to back
308 * and the pointer into the region must be updated since a later
309 * routine will need to perform another test.
312 xlog_find_verify_cycle(
314 xfs_daddr_t start_blk,
316 uint stop_on_cycle_no,
317 xfs_daddr_t *new_blk)
327 * Greedily allocate a buffer big enough to handle the full
328 * range of basic blocks we'll be examining. If that fails,
329 * try a smaller size. We need to be able to read at least
330 * a log sector, or we're out of luck.
332 bufblks = roundup_pow_of_two(nbblks);
333 while (bufblks > log->l_logBBsize)
335 while (!(buffer = xlog_alloc_buffer(log, bufblks))) {
337 if (bufblks < log->l_sectBBsize)
341 for (i = start_blk; i < start_blk + nbblks; i += bufblks) {
344 bcount = min(bufblks, (start_blk + nbblks - i));
346 error = xlog_bread(log, i, bcount, buffer, &buf);
350 for (j = 0; j < bcount; j++) {
351 cycle = xlog_get_cycle(buf);
352 if (cycle == stop_on_cycle_no) {
369 xlog_logrec_hblks(struct xlog *log, struct xlog_rec_header *rh)
371 if (xfs_has_logv2(log->l_mp)) {
372 int h_size = be32_to_cpu(rh->h_size);
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);
382 * Potentially backup over partial log record write.
384 * In the typical case, last_blk is the number of the block directly after
385 * a good log record. Therefore, we subtract one to get the block number
386 * of the last block in the given buffer. extra_bblks contains the number
387 * of blocks we would have read on a previous read. This happens when the
388 * last log record is split over the end of the physical log.
390 * extra_bblks is the number of blocks potentially verified on a previous
391 * call to this routine.
394 xlog_find_verify_log_record(
396 xfs_daddr_t start_blk,
397 xfs_daddr_t *last_blk,
403 xlog_rec_header_t *head = NULL;
406 int num_blks = *last_blk - start_blk;
409 ASSERT(start_blk != 0 || *last_blk != start_blk);
411 buffer = xlog_alloc_buffer(log, num_blks);
413 buffer = xlog_alloc_buffer(log, 1);
418 error = xlog_bread(log, start_blk, num_blks, buffer, &offset);
421 offset += ((num_blks - 1) << BBSHIFT);
424 for (i = (*last_blk) - 1; i >= 0; i--) {
426 /* valid log record not found */
428 "Log inconsistent (didn't find previous header)");
430 error = -EFSCORRUPTED;
435 error = xlog_bread(log, i, 1, buffer, &offset);
440 head = (xlog_rec_header_t *)offset;
442 if (head->h_magicno == cpu_to_be32(XLOG_HEADER_MAGIC_NUM))
450 * We hit the beginning of the physical log & still no header. Return
451 * to caller. If caller can handle a return of -1, then this routine
452 * will be called again for the end of the physical log.
460 * We have the final block of the good log (the first block
461 * of the log record _before_ the head. So we check the uuid.
463 if ((error = xlog_header_check_mount(log->l_mp, head)))
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 end
469 * up reading an entire log record. In this case, we don't want to
470 * reset last_blk. Only when last_blk points in the middle of a log
471 * record do we update last_blk.
473 xhdrs = xlog_logrec_hblks(log, head);
475 if (*last_blk - i + extra_bblks !=
476 BTOBB(be32_to_cpu(head->h_len)) + xhdrs)
485 * Head is defined to be the point of the log where the next log write
486 * could go. This means that incomplete LR writes at the end are
487 * eliminated when calculating the head. We aren't guaranteed that previous
488 * LR have complete transactions. We only know that a cycle number of
489 * current cycle number -1 won't be present in the log if we start writing
490 * from our current block number.
492 * last_blk contains the block number of the first block with a given
495 * Return: zero if normal, non-zero if error.
500 xfs_daddr_t *return_head_blk)
504 xfs_daddr_t new_blk, first_blk, start_blk, last_blk, head_blk;
506 uint first_half_cycle, last_half_cycle;
508 int error, log_bbnum = log->l_logBBsize;
510 /* Is the end of the log device zeroed? */
511 error = xlog_find_zeroed(log, &first_blk);
513 xfs_warn(log->l_mp, "empty log check failed");
517 *return_head_blk = first_blk;
519 /* Is the whole lot zeroed? */
521 /* Linux XFS shouldn't generate totally zeroed logs -
522 * mkfs etc write a dummy unmount record to a fresh
523 * log so we can store the uuid in there
525 xfs_warn(log->l_mp, "totally zeroed log");
531 first_blk = 0; /* get cycle # of 1st block */
532 buffer = xlog_alloc_buffer(log, 1);
536 error = xlog_bread(log, 0, 1, buffer, &offset);
538 goto out_free_buffer;
540 first_half_cycle = xlog_get_cycle(offset);
542 last_blk = head_blk = log_bbnum - 1; /* get cycle # of last block */
543 error = xlog_bread(log, last_blk, 1, buffer, &offset);
545 goto out_free_buffer;
547 last_half_cycle = xlog_get_cycle(offset);
548 ASSERT(last_half_cycle != 0);
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 this
553 * case, head_blk can't be set to zero (which makes sense). The below
554 * 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 this
556 * value makes the math correct. If head_blk doesn't changed through
557 * all the tests below, *head_blk is set to zero at the very end rather
558 * than log_bbnum. In a sense, log_bbnum and zero are the same block
559 * in a circular file.
561 if (first_half_cycle == last_half_cycle) {
563 * In this case we believe that the entire log should have
564 * cycle number last_half_cycle. We need to scan backwards
565 * from the end verifying that there are no holes still
566 * containing last_half_cycle - 1. If we find such a hole,
567 * then the start of that hole will be the new head. The
568 * simple case looks like
569 * x | x ... | x - 1 | x
570 * Another case that fits this picture would be
571 * x | x + 1 | x ... | x
572 * In this case the head really is somewhere at the end of the
573 * log, as one of the latest writes at the beginning was
576 * x | x + 1 | x ... | x - 1 | x
577 * This is really the combination of the above two cases, and
578 * the head has to end up at the start of the x-1 hole at the
581 * In the 256k log case, we will read from the beginning to the
582 * 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 log
587 head_blk = log_bbnum;
588 stop_on_cycle = last_half_cycle - 1;
591 * In this case we want to find the first block with cycle
592 * number matching last_half_cycle. We expect the log to be
594 * x + 1 ... | x ... | x
595 * The first block with cycle number x (last_half_cycle) will
596 * be where the new head belongs. First we do a binary search
597 * for the first occurrence of last_half_cycle. The binary
598 * search may not be totally accurate, so then we scan back
599 * from there looking for occurrences of last_half_cycle before
600 * us. If that backwards scan wraps around the beginning of
601 * the log, then we look for occurrences of last_half_cycle - 1
602 * at the end of the log. The cases we're looking for look
604 * v binary search stopped here
605 * x + 1 ... | x | x + 1 | x ... | x
606 * ^ but we want to locate this spot
608 * <---------> less than scan distance
609 * x + 1 ... | x ... | x - 1 | x
610 * ^ we want to locate this spot
612 stop_on_cycle = last_half_cycle;
613 error = xlog_find_cycle_start(log, buffer, first_blk, &head_blk,
616 goto out_free_buffer;
620 * Now validate the answer. Scan back some number of maximum possible
621 * blocks and make sure each one has the expected cycle number. The
622 * maximum is determined by the total possible amount of buffering
623 * in the in-core log. The following number can be made tighter if
624 * we actually look at the block size of the filesystem.
626 num_scan_bblks = min_t(int, log_bbnum, XLOG_TOTAL_REC_SHIFT(log));
627 if (head_blk >= num_scan_bblks) {
629 * We are guaranteed that the entire check can be performed
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;
639 } else { /* need to read 2 parts of log */
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 part
643 * of the log, we are looking for blocks with cycle number
644 * last_half_cycle - 1.
645 * If we find one, then we know that the log starts there, as
646 * we've found a hole that didn't get written in going around
647 * the end of the physical log. The simple case for this is
648 * x + 1 ... | x ... | x - 1 | x
649 * <---------> less than scan distance
650 * If all of the blocks at the end of the log have cycle number
651 * last_half_cycle, then we check the blocks at the start of
652 * the log looking for occurrences of last_half_cycle. If we
653 * find one, then our current estimate for the location of the
654 * first occurrence of last_half_cycle is wrong and we move
655 * back to the hole we've found. This case looks like
656 * x + 1 ... | x | x + 1 | x ...
657 * ^ binary search stopped here
658 * Another case we need to handle that only occurs in 256k
660 * x + 1 ... | x ... | x+1 | x ...
661 * ^ binary search stops here
662 * In a 256k log, the scan at the end of the log will see the
663 * x + 1 blocks. We need to skip past those since that is
664 * certainly not the head of the log. By searching for
665 * last_half_cycle-1 we accomplish that.
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;
680 * Scan beginning of log now. The last part of the physical
681 * log is good. This scan needs to verify that it doesn't find
682 * the last_half_cycle.
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;
696 * Now we need to make sure head_blk is not pointing to a block in
697 * the middle of a log record.
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 */
703 /* start ptr at last block ptr before head_blk */
704 error = xlog_find_verify_log_record(log, start_blk, &head_blk, 0);
708 goto out_free_buffer;
711 ASSERT(head_blk <= INT_MAX);
712 error = xlog_find_verify_log_record(log, start_blk, &head_blk, 0);
714 goto out_free_buffer;
716 /* We hit the beginning of the log during our search */
717 start_blk = log_bbnum - (num_scan_bblks - head_blk);
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);
727 goto out_free_buffer;
728 if (new_blk != log_bbnum)
731 goto out_free_buffer;
735 if (head_blk == log_bbnum)
736 *return_head_blk = 0;
738 *return_head_blk = head_blk;
740 * When returning here, we have a good block number. Bad block
741 * means that during a previous crash, we didn't have a clean break
742 * from cycle number N to cycle number N-1. In this case, we need
743 * to find the first block with cycle number N-1.
750 xfs_warn(log->l_mp, "failed to find log head");
755 * Seek backwards in the log for log record headers.
757 * Given a starting log block, walk backwards until we find the provided number
758 * of records or hit the provided tail block. The return value is the number of
759 * records encountered or a negative error code. The log block and buffer
760 * pointer of the last record seen are returned in rblk and rhead respectively.
763 xlog_rseek_logrec_hdr(
765 xfs_daddr_t head_blk,
766 xfs_daddr_t tail_blk,
770 struct xlog_rec_header **rhead,
782 * Walk backwards from the head block until we hit the tail or the first
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);
791 if (*(__be32 *) offset == cpu_to_be32(XLOG_HEADER_MAGIC_NUM)) {
793 *rhead = (struct xlog_rec_header *) offset;
794 if (++found == count)
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 that
802 * callers can pass head == tail if the tail is not yet known.
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);
810 if (*(__be32 *)offset ==
811 cpu_to_be32(XLOG_HEADER_MAGIC_NUM)) {
814 *rhead = (struct xlog_rec_header *) offset;
815 if (++found == count)
828 * Seek forward in the log for log record headers.
830 * Given head and tail blocks, walk forward from the tail block until we find
831 * the provided number of records or hit the head block. The return value is the
832 * number of records encountered or a negative error code. The log block and
833 * buffer pointer of the last record seen are returned in rblk and rhead
837 xlog_seek_logrec_hdr(
839 xfs_daddr_t head_blk,
840 xfs_daddr_t tail_blk,
844 struct xlog_rec_header **rhead,
856 * Walk forward from the tail block until we hit the head or the last
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);
865 if (*(__be32 *) offset == cpu_to_be32(XLOG_HEADER_MAGIC_NUM)) {
867 *rhead = (struct xlog_rec_header *) offset;
868 if (++found == count)
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.
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);
883 if (*(__be32 *)offset ==
884 cpu_to_be32(XLOG_HEADER_MAGIC_NUM)) {
887 *rhead = (struct xlog_rec_header *) offset;
888 if (++found == count)
901 * Calculate distance from head to tail (i.e., unused space in the log).
906 xfs_daddr_t head_blk,
907 xfs_daddr_t tail_blk)
909 if (head_blk < tail_blk)
910 return tail_blk - head_blk;
912 return tail_blk + (log->l_logBBsize - head_blk);
916 * Verify the log tail. This is particularly important when torn or incomplete
917 * writes have been detected near the front of the log and the head has been
918 * walked back accordingly.
920 * We also have to handle the case where the tail was pinned and the head
921 * blocked behind the tail right before a crash. If the tail had been pushed
922 * immediately prior to the crash and the subsequent checkpoint was only
923 * partially written, it's possible it overwrote the last referenced tail in the
924 * log with garbage. This is not a coherency problem because the tail must have
925 * been pushed before it can be overwritten, but appears as log corruption to
926 * recovery because we have no way to know the tail was updated if the
927 * subsequent checkpoint didn't write successfully.
929 * Therefore, CRC check the log from tail to head. If a failure occurs and the
930 * offending record is within max iclog bufs from the head, walk the tail
931 * forward and retry until a valid tail is found or corruption is detected out
932 * of the range of a possible overwrite.
937 xfs_daddr_t head_blk,
938 xfs_daddr_t *tail_blk,
941 struct xlog_rec_header *thead;
943 xfs_daddr_t first_bad;
946 xfs_daddr_t tmp_tail;
947 xfs_daddr_t orig_tail = *tail_blk;
949 buffer = xlog_alloc_buffer(log, 1);
954 * Make sure the tail points to a record (returns positive count on
957 error = xlog_seek_logrec_hdr(log, head_blk, *tail_blk, 1, buffer,
958 &tmp_tail, &thead, &wrapped);
961 if (*tail_blk != tmp_tail)
962 *tail_blk = tmp_tail;
965 * Run a CRC check from the tail to the head. We can't just check
966 * MAX_ICLOGS records past the tail because the tail may point to stale
967 * blocks cleared during the search for the head/tail. These blocks are
968 * overwritten with zero-length records and thus record count is not a
969 * reliable indicator of the iclog state before a crash.
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) {
978 * Is corruption within range of the head? If so, retry from
979 * the next record. Otherwise return an error.
981 tail_distance = xlog_tail_distance(log, head_blk, first_bad);
982 if (tail_distance > BTOBB(XLOG_MAX_ICLOGS * hsize))
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);
991 *tail_blk = tmp_tail;
993 error = xlog_do_recovery_pass(log, head_blk, *tail_blk,
994 XLOG_RECOVER_CRCPASS, &first_bad);
997 if (!error && *tail_blk != orig_tail)
999 "Tail block (0x%llx) overwrite detected. Updated to 0x%llx",
1000 orig_tail, *tail_blk);
1007 * Detect and trim torn writes from the head of the log.
1009 * Storage without sector atomicity guarantees can result in torn writes in the
1010 * log in the event of a crash. Our only means to detect this scenario is via
1011 * CRC verification. While we can't always be certain that CRC verification
1012 * failure is due to a torn write vs. an unrelated corruption, we do know that
1013 * only a certain number (XLOG_MAX_ICLOGS) of log records can be written out at
1014 * one time. Therefore, CRC verify up to XLOG_MAX_ICLOGS records at the head of
1015 * the log and treat failures in this range as torn writes as a matter of
1016 * policy. In the event of CRC failure, the head is walked back to the last good
1017 * record in the log and the tail is updated from that record and verified.
1022 xfs_daddr_t *head_blk, /* in/out: unverified head */
1023 xfs_daddr_t *tail_blk, /* out: tail block */
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 */
1029 struct xlog_rec_header *tmp_rhead;
1031 xfs_daddr_t first_bad;
1032 xfs_daddr_t tmp_rhead_blk;
1038 * Check the head of the log for torn writes. Search backwards from the
1039 * head until we hit the tail or the maximum number of log record I/Os
1040 * that could have been in flight at one time. Use a temporary buffer so
1041 * we don't trash the rhead/buffer pointers from the caller.
1043 tmp_buffer = xlog_alloc_buffer(log, 1);
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);
1054 * Now run a CRC verification pass over the records starting at the
1055 * block found above to the current head. If a CRC failure occurs, the
1056 * log block of the first bad record is saved in first_bad.
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) {
1062 * We've hit a potential torn write. Reset the error and warn
1067 "Torn write (CRC failure) detected at log block 0x%llx. Truncating head block from 0x%llx.",
1068 first_bad, *head_blk);
1071 * Get the header block and buffer pointer for the last good
1072 * record before the bad record.
1074 * Note that xlog_find_tail() clears the blocks at the new head
1075 * (i.e., the records with invalid CRC) if the cycle number
1076 * matches the current cycle.
1078 found = xlog_rseek_logrec_hdr(log, first_bad, *tail_blk, 1,
1079 buffer, rhead_blk, rhead, wrapped);
1082 if (found == 0) /* XXX: right thing to do here? */
1086 * Reset the head block to the starting block of the first bad
1087 * log record and set the tail block based on the last good
1090 * Bail out if the updated head/tail match as this indicates
1091 * possible corruption outside of the acceptable
1092 * (XLOG_MAX_ICLOGS) range. This is a job for xfs_repair...
1094 *head_blk = first_bad;
1095 *tail_blk = BLOCK_LSN(be64_to_cpu((*rhead)->h_tail_lsn));
1096 if (*head_blk == *tail_blk) {
1104 return xlog_verify_tail(log, *head_blk, tail_blk,
1105 be32_to_cpu((*rhead)->h_size));
1109 * We need to make sure we handle log wrapping properly, so we can't use the
1110 * calculated logbno directly. Make sure it wraps to the correct bno inside the
1113 * The log is limited to 32 bit sizes, so we use the appropriate modulus
1114 * operation here and cast it back to a 64 bit daddr on return.
1116 static inline xfs_daddr_t
1123 div_s64_rem(bno, log->l_logBBsize, &mod);
1128 * Check whether the head of the log points to an unmount record. In other
1129 * words, determine whether the log is clean. If so, update the in-core state
1133 xlog_check_unmount_rec(
1135 xfs_daddr_t *head_blk,
1136 xfs_daddr_t *tail_blk,
1137 struct xlog_rec_header *rhead,
1138 xfs_daddr_t rhead_blk,
1142 struct xlog_op_header *op_head;
1143 xfs_daddr_t umount_data_blk;
1144 xfs_daddr_t after_umount_blk;
1152 * Look for unmount record. If we find it, then we know there was a
1153 * clean unmount. Since 'i' could be the last block in the physical
1154 * log, we convert to a log block before comparing to the head_blk.
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, so
1158 * we pass the lsn of the unmount record rather than the block after it.
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)));
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);
1171 op_head = (struct xlog_op_header *)offset;
1172 if (op_head->oh_flags & XLOG_UNMOUNT_TRANS) {
1174 * Set tail and last sync so that newly written log
1175 * records will point recovery to after the current
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;
1194 xfs_daddr_t head_blk,
1195 struct xlog_rec_header *rhead,
1196 xfs_daddr_t rhead_blk,
1200 * Reset log values according to the state of the log when we
1201 * crashed. In the case where head_blk == 0, we bump curr_cycle
1202 * one because the next write starts a new cycle rather than
1203 * continuing the cycle of the last good log record. At this
1204 * point we have guaranteed that all partial log records have been
1205 * accounted for. Therefore, we know that the last good log record
1206 * written was complete and ended exactly on the end boundary
1207 * of the physical log.
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);
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);
1219 * Find the sync block number or the tail of the log.
1221 * This will be the block number of the last record to have its
1222 * associated buffers synced to disk. Every log record header has
1223 * a sync lsn embedded in it. LSNs hold block numbers, so it is easy
1224 * to get a sync block number. The only concern is to figure out which
1225 * log record header to believe.
1227 * The following algorithm uses the log record header with the largest
1228 * lsn. The entire log record does not need to be valid. We only care
1229 * that the header is valid.
1231 * We could speed up search by using current head_blk buffer, but it is not
1237 xfs_daddr_t *head_blk,
1238 xfs_daddr_t *tail_blk)
1240 xlog_rec_header_t *rhead;
1241 char *offset = NULL;
1244 xfs_daddr_t rhead_blk;
1246 bool wrapped = false;
1250 * Find previous log record
1252 if ((error = xlog_find_head(log, head_blk)))
1254 ASSERT(*head_blk < INT_MAX);
1256 buffer = xlog_alloc_buffer(log, 1);
1259 if (*head_blk == 0) { /* special case */
1260 error = xlog_bread(log, 0, 1, buffer, &offset);
1264 if (xlog_get_cycle(offset) == 0) {
1266 /* leave all other log inited values alone */
1272 * Search backwards through the log looking for the log record header
1273 * block. This wraps all the way back around to the head so something is
1274 * seriously wrong if we can't find it.
1276 error = xlog_rseek_logrec_hdr(log, *head_blk, *head_blk, 1, buffer,
1277 &rhead_blk, &rhead, &wrapped);
1281 xfs_warn(log->l_mp, "%s: couldn't find sync record", __func__);
1282 error = -EFSCORRUPTED;
1285 *tail_blk = BLOCK_LSN(be64_to_cpu(rhead->h_tail_lsn));
1288 * Set the log state based on the current head record.
1290 xlog_set_state(log, *head_blk, rhead, rhead_blk, wrapped);
1291 tail_lsn = atomic64_read(&log->l_tail_lsn);
1294 * Look for an unmount record at the head of the log. This sets the log
1295 * state to determine whether recovery is necessary.
1297 error = xlog_check_unmount_rec(log, head_blk, tail_blk, rhead,
1298 rhead_blk, buffer, &clean);
1303 * Verify the log head if the log is not clean (e.g., we have anything
1304 * but an unmount record at the head). This uses CRC verification to
1305 * detect and trim torn writes. If discovered, CRC failures are
1306 * considered torn writes and the log head is trimmed accordingly.
1308 * Note that we can only run CRC verification when the log is dirty
1309 * because there's no guarantee that the log data behind an unmount
1310 * record is compatible with the current architecture.
1313 xfs_daddr_t orig_head = *head_blk;
1315 error = xlog_verify_head(log, head_blk, tail_blk, buffer,
1316 &rhead_blk, &rhead, &wrapped);
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,
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,
1334 * Note that the unmount was clean. If the unmount was not clean, we
1335 * need to know this to rebuild the superblock counters from the perag
1336 * headers if we have a filesystem using non-persistent counters.
1339 xfs_set_clean(log->l_mp);
1342 * Make sure that there are no blocks in front of the head
1343 * with the same cycle number as the head. This can happen
1344 * because we allow multiple outstanding log writes concurrently,
1345 * and the later writes might make it out before earlier ones.
1347 * We use the lsn from before modifying it so that we'll never
1348 * overwrite the unmount record after a clean unmount.
1350 * Do this only if we are going to recover the filesystem
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.
1357 * But... if the -device- itself is readonly, just skip this.
1358 * We can't recover this device anyway, so it won't matter.
1360 if (!xfs_readonly_buftarg(log->l_targ))
1361 error = xlog_clear_stale_blocks(log, tail_lsn);
1367 xfs_warn(log->l_mp, "failed to locate log tail");
1372 * Is the log zeroed at all?
1374 * The last binary search should be changed to perform an X block read
1375 * once X becomes small enough. You can then search linearly through
1376 * the X blocks. This will cut down on the number of reads we need to do.
1378 * If the log is partially zeroed, this routine will pass back the blkno
1379 * of the first block with cycle number 0. It won't have a complete LR
1383 * 0 => the log is completely written to
1384 * 1 => use *blk_no as the first block of the log
1385 * <0 => error has occurred
1390 xfs_daddr_t *blk_no)
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;
1402 /* check totally zeroed log */
1403 buffer = xlog_alloc_buffer(log, 1);
1406 error = xlog_bread(log, 0, 1, buffer, &offset);
1408 goto out_free_buffer;
1410 first_cycle = xlog_get_cycle(offset);
1411 if (first_cycle == 0) { /* completely zeroed log */
1413 goto out_free_buffer;
1416 /* check partially zeroed log */
1417 error = xlog_bread(log, log_bbnum-1, 1, buffer, &offset);
1419 goto out_free_buffer;
1421 last_cycle = xlog_get_cycle(offset);
1422 if (last_cycle != 0) { /* log completely written to */
1424 goto out_free_buffer;
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);
1431 goto out_free_buffer;
1434 * Validate the answer. Because there is no way to guarantee that
1435 * 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 maximum
1437 * is not chosen to mean anything special. XXXmiken
1439 num_scan_bblks = XLOG_TOTAL_REC_SHIFT(log);
1440 ASSERT(num_scan_bblks <= INT_MAX);
1442 if (last_blk < num_scan_bblks)
1443 num_scan_bblks = last_blk;
1444 start_blk = last_blk - num_scan_bblks;
1447 * We search for any instances of cycle number 0 that occur before
1448 * our current estimate of the head. What we're trying to detect is
1449 * 1 ... | 0 | 1 | 0...
1450 * ^ binary search ends here
1452 if ((error = xlog_find_verify_cycle(log, start_blk,
1453 (int)num_scan_bblks, 0, &new_blk)))
1454 goto out_free_buffer;
1459 * Potentially backup over partial log record write. We don't need
1460 * to search the end of the log because we know it is zero.
1462 error = xlog_find_verify_log_record(log, start_blk, &last_blk, 0);
1466 goto out_free_buffer;
1477 * These are simple subroutines used by xlog_clear_stale_blocks() below
1478 * to initialize a buffer full of empty log record headers and write
1479 * them into the log.
1490 xlog_rec_header_t *recp = (xlog_rec_header_t *)buf;
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));
1504 xlog_write_log_records(
1515 int sectbb = log->l_sectBBsize;
1516 int end_block = start_block + blocks;
1522 * Greedily allocate a buffer big enough to handle the full
1523 * range of basic blocks to be written. If that fails, try
1524 * a smaller size. We need to be able to write at least a
1525 * log sector, or we're out of luck.
1527 bufblks = roundup_pow_of_two(blocks);
1528 while (bufblks > log->l_logBBsize)
1530 while (!(buffer = xlog_alloc_buffer(log, bufblks))) {
1532 if (bufblks < sectbb)
1536 /* We may need to do a read at the start to fill in part of
1537 * the buffer in the starting sector not covered by the first
1540 balign = round_down(start_block, sectbb);
1541 if (balign != start_block) {
1542 error = xlog_bread_noalign(log, start_block, 1, buffer);
1544 goto out_free_buffer;
1546 j = start_block - balign;
1549 for (i = start_block; i < end_block; i += bufblks) {
1550 int bcount, endcount;
1552 bcount = min(bufblks, end_block - start_block);
1553 endcount = bcount - j;
1555 /* We may need to do a read at the end to fill in part of
1556 * the buffer in the final sector not covered by the write.
1557 * If this is the same sector as the above read, skip it.
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));
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);
1574 error = xlog_bwrite(log, start_block, endcount, buffer);
1577 start_block += endcount;
1587 * This routine is called to blow away any incomplete log writes out
1588 * in front of the log head. We do this so that we won't become confused
1589 * 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 could
1591 * cause us to think those partial writes are valid blocks since they
1592 * have the current cycle number. We get rid of them by overwriting them
1593 * with empty log records with the old cycle number rather than the
1596 * The tail lsn is passed in rather than taken from
1597 * the log so that we will not write over the unmount record after a
1598 * clean unmount in a 512 block log. Doing so would leave the log without
1599 * any valid log records in it until a new one was written. If we crashed
1600 * during that time we would not be able to recover.
1603 xlog_clear_stale_blocks(
1607 int tail_cycle, head_cycle;
1608 int tail_block, head_block;
1609 int tail_distance, max_distance;
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;
1619 * Figure out the distance between the new head of the log
1620 * and the tail. We want to write over any blocks beyond the
1621 * head that we may have written just before the crash, but
1622 * we don't want to overwrite the tail of the log.
1624 if (head_cycle == tail_cycle) {
1626 * The tail is behind the head in the physical log,
1627 * so the distance from the head to the tail is the
1628 * distance from the head to the end of the log plus
1629 * the distance from the beginning of the log to the
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);
1639 * The head is behind the tail in the physical log,
1640 * so the distance from the head to the tail is just
1641 * the tail block minus the head block.
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;
1651 * If the head is right up against the tail, we can't clear
1654 if (tail_distance <= 0) {
1655 ASSERT(tail_distance == 0);
1659 max_distance = XLOG_TOTAL_REC_SHIFT(log);
1661 * Take the smaller of the maximum amount of outstanding I/O
1662 * 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 and
1664 * we don't waste all day writing from the head to the tail
1667 max_distance = min(max_distance, tail_distance);
1669 if ((head_block + max_distance) <= log->l_logBBsize) {
1671 * We can stomp all the blocks we need to without
1672 * wrapping around the end of the log. Just do it
1673 * in a single write. Use the cycle number of the
1674 * current cycle minus one so that the log will look like:
1677 error = xlog_write_log_records(log, (head_cycle - 1),
1678 head_block, max_distance, tail_cycle,
1684 * We need to wrap around the end of the physical log in
1685 * order to clear all the blocks. Do it in two separate
1686 * I/Os. The first write should be from the head to the
1687 * end of the physical log, and it should use the current
1688 * cycle number minus one just like above.
1690 distance = log->l_logBBsize - head_block;
1691 error = xlog_write_log_records(log, (head_cycle - 1),
1692 head_block, distance, tail_cycle,
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 the
1702 * same cycle as the head so that we get:
1703 * n ... n ... | n - 1 ...
1704 * ^^^^^ blocks we're writing
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);
1717 * Release the recovered intent item in the AIL that matches the given intent
1718 * type and intent id.
1721 xlog_recover_release_intent(
1723 unsigned short intent_type,
1726 struct xfs_defer_pending *dfp, *n;
1728 list_for_each_entry_safe(dfp, n, &log->r_dfops, dfp_list) {
1729 struct xfs_log_item *lip = dfp->dfp_intent;
1731 if (lip->li_type != intent_type)
1733 if (!lip->li_ops->iop_match(lip, intent_id))
1736 ASSERT(xlog_item_is_intent(lip));
1738 xfs_defer_cancel_recovery(log->l_mp, dfp);
1744 struct xfs_mount *mp,
1746 struct xfs_inode **ipp)
1750 error = xfs_iget(mp, NULL, ino, 0, 0, ipp);
1754 error = xfs_qm_dqattach(*ipp);
1760 if (VFS_I(*ipp)->i_nlink == 0)
1761 xfs_iflags_set(*ipp, XFS_IRECOVERY);
1767 * Get an inode so that we can recover a log operation.
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 for
1771 * other file handles. Log intent items defined after this validation weakness
1772 * was identified must use this function.
1775 xlog_recover_iget_handle(
1776 struct xfs_mount *mp,
1779 struct xfs_inode **ipp)
1781 struct xfs_inode *ip;
1784 error = xlog_recover_iget(mp, ino, &ip);
1788 if (VFS_I(ip)->i_generation != gen) {
1790 return -EFSCORRUPTED;
1797 /******************************************************************************
1799 * Log recover routines
1801 ******************************************************************************
1803 static const struct xlog_recover_item_ops *xlog_recover_item_ops[] = {
1805 &xlog_inode_item_ops,
1806 &xlog_dquot_item_ops,
1807 &xlog_quotaoff_item_ops,
1808 &xlog_icreate_item_ops,
1817 &xlog_attri_item_ops,
1818 &xlog_attrd_item_ops,
1821 &xlog_rtefi_item_ops,
1822 &xlog_rtefd_item_ops,
1823 &xlog_rtrui_item_ops,
1824 &xlog_rtrud_item_ops,
1825 &xlog_rtcui_item_ops,
1826 &xlog_rtcud_item_ops,
1829 static const struct xlog_recover_item_ops *
1831 struct xlog_recover_item *item)
1835 for (i = 0; i < ARRAY_SIZE(xlog_recover_item_ops); i++)
1836 if (ITEM_TYPE(item) == xlog_recover_item_ops[i]->item_type)
1837 return xlog_recover_item_ops[i];
1843 * Sort the log items in the transaction.
1845 * The ordering constraints are defined by the inode allocation and unlink
1846 * behaviour. The rules are:
1848 * 1. Every item is only logged once in a given transaction. Hence it
1849 * represents the last logged state of the item. Hence ordering is
1850 * dependent on the order in which operations need to be performed so
1851 * required initial conditions are always met.
1853 * 2. Cancelled buffers are recorded in pass 1 in a separate table and
1854 * there's nothing to replay from them so we can simply cull them
1855 * from the transaction. However, we can't do that until after we've
1856 * replayed all the other items because they may be dependent on the
1857 * cancelled buffer and replaying the cancelled buffer can remove it
1858 * form the cancelled buffer table. Hence they have to be done last.
1860 * 3. Inode allocation buffers must be replayed before inode items that
1861 * read the buffer and replay changes into it. For filesystems using the
1862 * ICREATE transactions, this means XFS_LI_ICREATE objects need to get
1863 * treated the same as inode allocation buffers as they create and
1864 * initialise the buffers directly.
1866 * 4. Inode unlink buffers must be replayed after inode items are replayed.
1867 * This ensures that inodes are completely flushed to the inode buffer
1868 * in a "free" state before we remove the unlinked inode list pointer.
1870 * Hence the ordering needs to be inode allocation buffers first, inode items
1871 * second, inode unlink buffers third and cancelled buffers last.
1873 * But there's a problem with that - we can't tell an inode allocation buffer
1874 * apart from a regular buffer, so we can't separate them. We can, however,
1875 * tell an inode unlink buffer from the others, and so we can separate them out
1876 * from all the other buffers and move them to last.
1878 * Hence, 4 lists, in order from head to tail:
1879 * - buffer_list for all buffers except cancelled/inode unlink buffers
1880 * - item_list for all non-buffer items
1881 * - inode_buffer_list for inode unlink buffers
1882 * - cancel_list for the cancelled buffers
1884 * Note that we add objects to the tail of the lists so that first-to-last
1885 * ordering is preserved within the lists. Adding objects to the head of the
1886 * list means when we traverse from the head we walk them in last-to-first
1887 * order. For cancelled buffers and inode unlink buffers this doesn't matter,
1888 * but for all other items there may be specific ordering that we need to
1892 xlog_recover_reorder_trans(
1894 struct xlog_recover *trans,
1897 struct xlog_recover_item *item, *n;
1899 LIST_HEAD(sort_list);
1900 LIST_HEAD(cancel_list);
1901 LIST_HEAD(buffer_list);
1902 LIST_HEAD(inode_buffer_list);
1903 LIST_HEAD(item_list);
1905 list_splice_init(&trans->r_itemq, &sort_list);
1906 list_for_each_entry_safe(item, n, &sort_list, ri_list) {
1907 enum xlog_recover_reorder fate = XLOG_REORDER_ITEM_LIST;
1909 item->ri_ops = xlog_find_item_ops(item);
1910 if (!item->ri_ops) {
1912 "%s: unrecognized type of log operation (%d)",
1913 __func__, ITEM_TYPE(item));
1916 * return the remaining items back to the transaction
1917 * item list so they can be freed in caller.
1919 if (!list_empty(&sort_list))
1920 list_splice_init(&sort_list, &trans->r_itemq);
1921 error = -EFSCORRUPTED;
1925 if (item->ri_ops->reorder)
1926 fate = item->ri_ops->reorder(item);
1929 case XLOG_REORDER_BUFFER_LIST:
1930 list_move_tail(&item->ri_list, &buffer_list);
1932 case XLOG_REORDER_CANCEL_LIST:
1933 trace_xfs_log_recover_item_reorder_head(log,
1935 list_move(&item->ri_list, &cancel_list);
1937 case XLOG_REORDER_INODE_BUFFER_LIST:
1938 list_move(&item->ri_list, &inode_buffer_list);
1940 case XLOG_REORDER_ITEM_LIST:
1941 trace_xfs_log_recover_item_reorder_tail(log,
1943 list_move_tail(&item->ri_list, &item_list);
1948 ASSERT(list_empty(&sort_list));
1949 if (!list_empty(&buffer_list))
1950 list_splice(&buffer_list, &trans->r_itemq);
1951 if (!list_empty(&item_list))
1952 list_splice_tail(&item_list, &trans->r_itemq);
1953 if (!list_empty(&inode_buffer_list))
1954 list_splice_tail(&inode_buffer_list, &trans->r_itemq);
1955 if (!list_empty(&cancel_list))
1956 list_splice_tail(&cancel_list, &trans->r_itemq);
1965 const struct xfs_buf_ops *ops)
1967 if (!xlog_is_buffer_cancelled(log, blkno, len))
1968 xfs_buf_readahead(log->l_mp->m_ddev_targp, blkno, len, ops);
1972 * Create a deferred work structure for resuming and tracking the progress of a
1973 * log intent item that was found during recovery.
1976 xlog_recover_intent_item(
1978 struct xfs_log_item *lip,
1980 const struct xfs_defer_op_type *ops)
1982 ASSERT(xlog_item_is_intent(lip));
1984 xfs_defer_start_recovery(lip, &log->r_dfops, ops);
1987 * Insert the intent into the AIL directly and drop one reference so
1988 * that finishing or canceling the work will drop the other.
1990 xfs_trans_ail_insert(log->l_ailp, lip, lsn);
1991 lip->li_ops->iop_unpin(lip, 0);
1995 xlog_recover_items_pass2(
1997 struct xlog_recover *trans,
1998 struct list_head *buffer_list,
1999 struct list_head *item_list)
2001 struct xlog_recover_item *item;
2004 list_for_each_entry(item, item_list, ri_list) {
2005 trace_xfs_log_recover_item_recover(log, trans, item,
2006 XLOG_RECOVER_PASS2);
2008 if (item->ri_ops->commit_pass2)
2009 error = item->ri_ops->commit_pass2(log, buffer_list,
2010 item, trans->r_lsn);
2019 * Perform the transaction.
2021 * If the transaction modifies a buffer or inode, do it now. Otherwise,
2022 * EFIs and EFDs get queued up by adding entries into the AIL for them.
2025 xlog_recover_commit_trans(
2027 struct xlog_recover *trans,
2029 struct list_head *buffer_list)
2032 int items_queued = 0;
2033 struct xlog_recover_item *item;
2034 struct xlog_recover_item *next;
2035 LIST_HEAD (ra_list);
2036 LIST_HEAD (done_list);
2038 #define XLOG_RECOVER_COMMIT_QUEUE_MAX 100
2040 hlist_del_init(&trans->r_list);
2042 error = xlog_recover_reorder_trans(log, trans, pass);
2046 list_for_each_entry_safe(item, next, &trans->r_itemq, ri_list) {
2047 trace_xfs_log_recover_item_recover(log, trans, item, pass);
2050 case XLOG_RECOVER_PASS1:
2051 if (item->ri_ops->commit_pass1)
2052 error = item->ri_ops->commit_pass1(log, item);
2054 case XLOG_RECOVER_PASS2:
2055 if (item->ri_ops->ra_pass2)
2056 item->ri_ops->ra_pass2(log, item);
2057 list_move_tail(&item->ri_list, &ra_list);
2059 if (items_queued >= XLOG_RECOVER_COMMIT_QUEUE_MAX) {
2060 error = xlog_recover_items_pass2(log, trans,
2061 buffer_list, &ra_list);
2062 list_splice_tail_init(&ra_list, &done_list);
2076 if (!list_empty(&ra_list)) {
2078 error = xlog_recover_items_pass2(log, trans,
2079 buffer_list, &ra_list);
2080 list_splice_tail_init(&ra_list, &done_list);
2083 if (!list_empty(&done_list))
2084 list_splice_init(&done_list, &trans->r_itemq);
2090 xlog_recover_add_item(
2091 struct list_head *head)
2093 struct xlog_recover_item *item;
2095 item = kzalloc(sizeof(struct xlog_recover_item),
2096 GFP_KERNEL | __GFP_NOFAIL);
2097 INIT_LIST_HEAD(&item->ri_list);
2098 list_add_tail(&item->ri_list, head);
2102 xlog_recover_add_to_cont_trans(
2104 struct xlog_recover *trans,
2108 struct xlog_recover_item *item;
2109 char *ptr, *old_ptr;
2113 * If the transaction is empty, the header was split across this and the
2114 * previous record. Copy the rest of the header.
2116 if (list_empty(&trans->r_itemq)) {
2117 ASSERT(len <= sizeof(struct xfs_trans_header));
2118 if (len > sizeof(struct xfs_trans_header)) {
2119 xfs_warn(log->l_mp, "%s: bad header length", __func__);
2120 return -EFSCORRUPTED;
2123 xlog_recover_add_item(&trans->r_itemq);
2124 ptr = (char *)&trans->r_theader +
2125 sizeof(struct xfs_trans_header) - len;
2126 memcpy(ptr, dp, len);
2130 /* take the tail entry */
2131 item = list_entry(trans->r_itemq.prev, struct xlog_recover_item,
2134 old_ptr = item->ri_buf[item->ri_cnt-1].i_addr;
2135 old_len = item->ri_buf[item->ri_cnt-1].i_len;
2137 ptr = kvrealloc(old_ptr, len + old_len, GFP_KERNEL);
2140 memcpy(&ptr[old_len], dp, len);
2141 item->ri_buf[item->ri_cnt-1].i_len += len;
2142 item->ri_buf[item->ri_cnt-1].i_addr = ptr;
2143 trace_xfs_log_recover_item_add_cont(log, trans, item, 0);
2148 * The next region to add is the start of a new region. It could be
2149 * a whole region or it could be the first part of a new region. Because
2150 * of this, the assumption here is that the type and size fields of all
2151 * format structures fit into the first 32 bits of the structure.
2153 * This works because all regions must be 32 bit aligned. Therefore, we
2154 * either have both fields or we have neither field. In the case we have
2155 * neither field, the data part of the region is zero length. We only have
2156 * a log_op_header and can throw away the header since a new one will appear
2157 * later. If we have at least 4 bytes, then we can determine how many regions
2158 * will appear in the current log item.
2161 xlog_recover_add_to_trans(
2163 struct xlog_recover *trans,
2167 struct xfs_inode_log_format *in_f; /* any will do */
2168 struct xlog_recover_item *item;
2173 if (list_empty(&trans->r_itemq)) {
2174 /* we need to catch log corruptions here */
2175 if (*(uint *)dp != XFS_TRANS_HEADER_MAGIC) {
2176 xfs_warn(log->l_mp, "%s: bad header magic number",
2179 return -EFSCORRUPTED;
2182 if (len > sizeof(struct xfs_trans_header)) {
2183 xfs_warn(log->l_mp, "%s: bad header length", __func__);
2185 return -EFSCORRUPTED;
2189 * The transaction header can be arbitrarily split across op
2190 * records. If we don't have the whole thing here, copy what we
2191 * do have and handle the rest in the next record.
2193 if (len == sizeof(struct xfs_trans_header))
2194 xlog_recover_add_item(&trans->r_itemq);
2195 memcpy(&trans->r_theader, dp, len);
2199 ptr = xlog_kvmalloc(len);
2200 memcpy(ptr, dp, len);
2201 in_f = (struct xfs_inode_log_format *)ptr;
2203 /* take the tail entry */
2204 item = list_entry(trans->r_itemq.prev, struct xlog_recover_item,
2206 if (item->ri_total != 0 &&
2207 item->ri_total == item->ri_cnt) {
2208 /* tail item is in use, get a new one */
2209 xlog_recover_add_item(&trans->r_itemq);
2210 item = list_entry(trans->r_itemq.prev,
2211 struct xlog_recover_item, ri_list);
2214 if (item->ri_total == 0) { /* first region to be added */
2215 if (in_f->ilf_size == 0 ||
2216 in_f->ilf_size > XLOG_MAX_REGIONS_IN_ITEM) {
2218 "bad number of regions (%d) in inode log format",
2222 return -EFSCORRUPTED;
2225 item->ri_total = in_f->ilf_size;
2226 item->ri_buf = kzalloc(item->ri_total * sizeof(xfs_log_iovec_t),
2227 GFP_KERNEL | __GFP_NOFAIL);
2230 if (item->ri_total <= item->ri_cnt) {
2232 "log item region count (%d) overflowed size (%d)",
2233 item->ri_cnt, item->ri_total);
2236 return -EFSCORRUPTED;
2239 /* Description region is ri_buf[0] */
2240 item->ri_buf[item->ri_cnt].i_addr = ptr;
2241 item->ri_buf[item->ri_cnt].i_len = len;
2243 trace_xfs_log_recover_item_add(log, trans, item, 0);
2248 * Free up any resources allocated by the transaction
2250 * Remember that EFIs, EFDs, and IUNLINKs are handled later.
2253 xlog_recover_free_trans(
2254 struct xlog_recover *trans)
2256 struct xlog_recover_item *item, *n;
2259 hlist_del_init(&trans->r_list);
2261 list_for_each_entry_safe(item, n, &trans->r_itemq, ri_list) {
2262 /* Free the regions in the item. */
2263 list_del(&item->ri_list);
2264 for (i = 0; i < item->ri_cnt; i++)
2265 kvfree(item->ri_buf[i].i_addr);
2266 /* Free the item itself */
2267 kfree(item->ri_buf);
2270 /* Free the transaction recover structure */
2275 * On error or completion, trans is freed.
2278 xlog_recovery_process_trans(
2280 struct xlog_recover *trans,
2285 struct list_head *buffer_list)
2288 bool freeit = false;
2290 /* mask off ophdr transaction container flags */
2291 flags &= ~XLOG_END_TRANS;
2292 if (flags & XLOG_WAS_CONT_TRANS)
2293 flags &= ~XLOG_CONTINUE_TRANS;
2296 * Callees must not free the trans structure. We'll decide if we need to
2297 * free it or not based on the operation being done and it's result.
2300 /* expected flag values */
2302 case XLOG_CONTINUE_TRANS:
2303 error = xlog_recover_add_to_trans(log, trans, dp, len);
2305 case XLOG_WAS_CONT_TRANS:
2306 error = xlog_recover_add_to_cont_trans(log, trans, dp, len);
2308 case XLOG_COMMIT_TRANS:
2309 error = xlog_recover_commit_trans(log, trans, pass,
2311 /* success or fail, we are now done with this transaction. */
2315 /* unexpected flag values */
2316 case XLOG_UNMOUNT_TRANS:
2317 /* just skip trans */
2318 xfs_warn(log->l_mp, "%s: Unmount LR", __func__);
2321 case XLOG_START_TRANS:
2323 xfs_warn(log->l_mp, "%s: bad flag 0x%x", __func__, flags);
2325 error = -EFSCORRUPTED;
2328 if (error || freeit)
2329 xlog_recover_free_trans(trans);
2334 * Lookup the transaction recovery structure associated with the ID in the
2335 * current ophdr. If the transaction doesn't exist and the start flag is set in
2336 * the ophdr, then allocate a new transaction for future ID matches to find.
2337 * Either way, return what we found during the lookup - an existing transaction
2340 STATIC struct xlog_recover *
2341 xlog_recover_ophdr_to_trans(
2342 struct hlist_head rhash[],
2343 struct xlog_rec_header *rhead,
2344 struct xlog_op_header *ohead)
2346 struct xlog_recover *trans;
2348 struct hlist_head *rhp;
2350 tid = be32_to_cpu(ohead->oh_tid);
2351 rhp = &rhash[XLOG_RHASH(tid)];
2352 hlist_for_each_entry(trans, rhp, r_list) {
2353 if (trans->r_log_tid == tid)
2358 * skip over non-start transaction headers - we could be
2359 * processing slack space before the next transaction starts
2361 if (!(ohead->oh_flags & XLOG_START_TRANS))
2364 ASSERT(be32_to_cpu(ohead->oh_len) == 0);
2367 * This is a new transaction so allocate a new recovery container to
2368 * hold the recovery ops that will follow.
2370 trans = kzalloc(sizeof(struct xlog_recover), GFP_KERNEL | __GFP_NOFAIL);
2371 trans->r_log_tid = tid;
2372 trans->r_lsn = be64_to_cpu(rhead->h_lsn);
2373 INIT_LIST_HEAD(&trans->r_itemq);
2374 INIT_HLIST_NODE(&trans->r_list);
2375 hlist_add_head(&trans->r_list, rhp);
2378 * Nothing more to do for this ophdr. Items to be added to this new
2379 * transaction will be in subsequent ophdr containers.
2385 xlog_recover_process_ophdr(
2387 struct hlist_head rhash[],
2388 struct xlog_rec_header *rhead,
2389 struct xlog_op_header *ohead,
2393 struct list_head *buffer_list)
2395 struct xlog_recover *trans;
2399 /* Do we understand who wrote this op? */
2400 if (ohead->oh_clientid != XFS_TRANSACTION &&
2401 ohead->oh_clientid != XFS_LOG) {
2402 xfs_warn(log->l_mp, "%s: bad clientid 0x%x",
2403 __func__, ohead->oh_clientid);
2405 return -EFSCORRUPTED;
2409 * Check the ophdr contains all the data it is supposed to contain.
2411 len = be32_to_cpu(ohead->oh_len);
2412 if (dp + len > end) {
2413 xfs_warn(log->l_mp, "%s: bad length 0x%x", __func__, len);
2415 return -EFSCORRUPTED;
2418 trans = xlog_recover_ophdr_to_trans(rhash, rhead, ohead);
2420 /* nothing to do, so skip over this ophdr */
2425 * The recovered buffer queue is drained only once we know that all
2426 * recovery items for the current LSN have been processed. This is
2429 * - Buffer write submission updates the metadata LSN of the buffer.
2430 * - Log recovery skips items with a metadata LSN >= the current LSN of
2431 * the recovery item.
2432 * - Separate recovery items against the same metadata buffer can share
2433 * a current LSN. I.e., consider that the LSN of a recovery item is
2434 * defined as the starting LSN of the first record in which its
2435 * transaction appears, that a record can hold multiple transactions,
2436 * and/or that a transaction can span multiple records.
2438 * In other words, we are allowed to submit a buffer from log recovery
2439 * once per current LSN. Otherwise, we may incorrectly skip recovery
2440 * items and cause corruption.
2442 * We don't know up front whether buffers are updated multiple times per
2443 * LSN. Therefore, track the current LSN of each commit log record as it
2444 * is processed and drain the queue when it changes. Use commit records
2445 * because they are ordered correctly by the logging code.
2447 if (log->l_recovery_lsn != trans->r_lsn &&
2448 ohead->oh_flags & XLOG_COMMIT_TRANS) {
2449 error = xfs_buf_delwri_submit(buffer_list);
2452 log->l_recovery_lsn = trans->r_lsn;
2455 return xlog_recovery_process_trans(log, trans, dp, len,
2456 ohead->oh_flags, pass, buffer_list);
2460 * There are two valid states of the r_state field. 0 indicates that the
2461 * transaction structure is in a normal state. We have either seen the
2462 * start of the transaction or the last operation we added was not a partial
2463 * operation. If the last operation we added to the transaction was a
2464 * partial operation, we need to mark r_state with XLOG_WAS_CONT_TRANS.
2466 * NOTE: skip LRs with 0 data length.
2469 xlog_recover_process_data(
2471 struct hlist_head rhash[],
2472 struct xlog_rec_header *rhead,
2475 struct list_head *buffer_list)
2477 struct xlog_op_header *ohead;
2482 end = dp + be32_to_cpu(rhead->h_len);
2483 num_logops = be32_to_cpu(rhead->h_num_logops);
2485 /* check the log format matches our own - else we can't recover */
2486 if (xlog_header_check_recover(log->l_mp, rhead))
2489 trace_xfs_log_recover_record(log, rhead, pass);
2490 while ((dp < end) && num_logops) {
2492 ohead = (struct xlog_op_header *)dp;
2493 dp += sizeof(*ohead);
2495 xfs_warn(log->l_mp, "%s: op header overrun", __func__);
2496 return -EFSCORRUPTED;
2499 /* errors will abort recovery */
2500 error = xlog_recover_process_ophdr(log, rhash, rhead, ohead,
2501 dp, end, pass, buffer_list);
2505 dp += be32_to_cpu(ohead->oh_len);
2511 /* Take all the collected deferred ops and finish them in order. */
2513 xlog_finish_defer_ops(
2514 struct xfs_mount *mp,
2515 struct list_head *capture_list)
2517 struct xfs_defer_capture *dfc, *next;
2518 struct xfs_trans *tp;
2521 list_for_each_entry_safe(dfc, next, capture_list, dfc_list) {
2522 struct xfs_trans_res resv;
2523 struct xfs_defer_resources dres;
2526 * Create a new transaction reservation from the captured
2527 * information. Set logcount to 1 to force the new transaction
2528 * to regrant every roll so that we can make forward progress
2529 * in recovery no matter how full the log might be.
2531 resv.tr_logres = dfc->dfc_logres;
2532 resv.tr_logcount = 1;
2533 resv.tr_logflags = XFS_TRANS_PERM_LOG_RES;
2535 error = xfs_trans_alloc(mp, &resv, dfc->dfc_blkres,
2536 dfc->dfc_rtxres, XFS_TRANS_RESERVE, &tp);
2538 xlog_force_shutdown(mp->m_log, SHUTDOWN_LOG_IO_ERROR);
2543 * Transfer to this new transaction all the dfops we captured
2544 * from recovering a single intent item.
2546 list_del_init(&dfc->dfc_list);
2547 xfs_defer_ops_continue(dfc, tp, &dres);
2548 error = xfs_trans_commit(tp);
2549 xfs_defer_resources_rele(&dres);
2554 ASSERT(list_empty(capture_list));
2558 /* Release all the captured defer ops and capture structures in this list. */
2560 xlog_abort_defer_ops(
2561 struct xfs_mount *mp,
2562 struct list_head *capture_list)
2564 struct xfs_defer_capture *dfc;
2565 struct xfs_defer_capture *next;
2567 list_for_each_entry_safe(dfc, next, capture_list, dfc_list) {
2568 list_del_init(&dfc->dfc_list);
2569 xfs_defer_ops_capture_abort(mp, dfc);
2574 * When this is called, all of the log intent items which did not have
2575 * corresponding log done items should be in the AIL. What we do now is update
2576 * the data structures associated with each one.
2578 * Since we process the log intent items in normal transactions, they will be
2579 * removed at some point after the commit. This prevents us from just walking
2580 * down the list processing each one. We'll use a flag in the intent item to
2581 * skip those that we've already processed and use the AIL iteration mechanism's
2582 * generation count to try to speed this up at least a bit.
2584 * When we start, we know that the intents are the only things in the AIL. As we
2585 * process them, however, other items are added to the AIL. Hence we know we
2586 * have started recovery on all the pending intents when we find an non-intent
2590 xlog_recover_process_intents(
2593 LIST_HEAD(capture_list);
2594 struct xfs_defer_pending *dfp, *n;
2596 #if defined(DEBUG) || defined(XFS_WARN)
2599 last_lsn = xlog_assign_lsn(log->l_curr_cycle, log->l_curr_block);
2602 list_for_each_entry_safe(dfp, n, &log->r_dfops, dfp_list) {
2603 ASSERT(xlog_item_is_intent(dfp->dfp_intent));
2606 * We should never see a redo item with a LSN higher than
2607 * the last transaction we found in the log at the start
2610 ASSERT(XFS_LSN_CMP(last_lsn, dfp->dfp_intent->li_lsn) >= 0);
2613 * NOTE: If your intent processing routine can create more
2614 * deferred ops, you /must/ attach them to the capture list in
2615 * the recover routine or else those subsequent intents will be
2616 * replayed in the wrong order!
2618 * The recovery function can free the log item, so we must not
2619 * access dfp->dfp_intent after it returns. It must dispose of
2620 * @dfp if it returns 0.
2622 error = xfs_defer_finish_recovery(log->l_mp, dfp,
2630 error = xlog_finish_defer_ops(log->l_mp, &capture_list);
2636 xlog_abort_defer_ops(log->l_mp, &capture_list);
2641 * A cancel occurs when the mount has failed and we're bailing out. Release all
2642 * pending log intent items that we haven't started recovery on so they don't
2646 xlog_recover_cancel_intents(
2649 struct xfs_defer_pending *dfp, *n;
2651 list_for_each_entry_safe(dfp, n, &log->r_dfops, dfp_list) {
2652 ASSERT(xlog_item_is_intent(dfp->dfp_intent));
2654 xfs_defer_cancel_recovery(log->l_mp, dfp);
2659 * Transfer ownership of the recovered pending work to the recovery transaction
2660 * and try to finish the work. If there is more work to be done, the dfp will
2661 * remain attached to the transaction. If not, the dfp is freed.
2664 xlog_recover_finish_intent(
2665 struct xfs_trans *tp,
2666 struct xfs_defer_pending *dfp)
2670 list_move(&dfp->dfp_list, &tp->t_dfops);
2671 error = xfs_defer_finish_one(tp, dfp);
2672 if (error == -EAGAIN)
2678 * This routine performs a transaction to null out a bad inode pointer
2679 * in an agi unlinked inode hash bucket.
2682 xlog_recover_clear_agi_bucket(
2683 struct xfs_perag *pag,
2686 struct xfs_mount *mp = pag_mount(pag);
2687 struct xfs_trans *tp;
2688 struct xfs_agi *agi;
2689 struct xfs_buf *agibp;
2693 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_clearagi, 0, 0, 0, &tp);
2697 error = xfs_read_agi(pag, tp, 0, &agibp);
2701 agi = agibp->b_addr;
2702 agi->agi_unlinked[bucket] = cpu_to_be32(NULLAGINO);
2703 offset = offsetof(xfs_agi_t, agi_unlinked) +
2704 (sizeof(xfs_agino_t) * bucket);
2705 xfs_trans_log_buf(tp, agibp, offset,
2706 (offset + sizeof(xfs_agino_t) - 1));
2708 error = xfs_trans_commit(tp);
2714 xfs_trans_cancel(tp);
2716 xfs_warn(mp, "%s: failed to clear agi %d. Continuing.", __func__,
2722 xlog_recover_iunlink_bucket(
2723 struct xfs_perag *pag,
2724 struct xfs_agi *agi,
2727 struct xfs_mount *mp = pag_mount(pag);
2728 struct xfs_inode *prev_ip = NULL;
2729 struct xfs_inode *ip;
2730 xfs_agino_t prev_agino, agino;
2733 agino = be32_to_cpu(agi->agi_unlinked[bucket]);
2734 while (agino != NULLAGINO) {
2735 error = xfs_iget(mp, NULL, xfs_agino_to_ino(pag, agino), 0, 0,
2740 ASSERT(VFS_I(ip)->i_nlink == 0);
2741 ASSERT(VFS_I(ip)->i_mode != 0);
2742 xfs_iflags_clear(ip, XFS_IRECOVERY);
2743 agino = ip->i_next_unlinked;
2746 ip->i_prev_unlinked = prev_agino;
2750 * Ensure the inode is removed from the unlinked list
2751 * before we continue so that it won't race with
2752 * building the in-memory list here. This could be
2753 * serialised with the agibp lock, but that just
2754 * serialises via lockstepping and it's much simpler
2755 * just to flush the inodegc queue and wait for it to
2758 error = xfs_inodegc_flush(mp);
2770 ip->i_prev_unlinked = prev_agino;
2773 error2 = xfs_inodegc_flush(mp);
2774 if (error2 && !error)
2781 * Recover AGI unlinked lists
2783 * This is called during recovery to process any inodes which we unlinked but
2784 * not freed when the system crashed. These inodes will be on the lists in the
2785 * AGI blocks. What we do here is scan all the AGIs and fully truncate and free
2786 * any inodes found on the lists. Each inode is removed from the lists when it
2787 * has been fully truncated and is freed. The freeing of the inode and its
2788 * removal from the list must be atomic.
2790 * If everything we touch in the agi processing loop is already in memory, this
2791 * loop can hold the cpu for a long time. It runs without lock contention,
2792 * memory allocation contention, the need wait for IO, etc, and so will run
2793 * until we either run out of inodes to process, run low on memory or we run out
2796 * This behaviour is bad for latency on single CPU and non-preemptible kernels,
2797 * and can prevent other filesystem work (such as CIL pushes) from running. This
2798 * can lead to deadlocks if the recovery process runs out of log reservation
2799 * space. Hence we need to yield the CPU when there is other kernel work
2800 * scheduled on this CPU to ensure other scheduled work can run without undue
2804 xlog_recover_iunlink_ag(
2805 struct xfs_perag *pag)
2807 struct xfs_agi *agi;
2808 struct xfs_buf *agibp;
2812 error = xfs_read_agi(pag, NULL, 0, &agibp);
2815 * AGI is b0rked. Don't process it.
2817 * We should probably mark the filesystem as corrupt after we've
2818 * recovered all the ag's we can....
2824 * Unlock the buffer so that it can be acquired in the normal course of
2825 * the transaction to truncate and free each inode. Because we are not
2826 * racing with anyone else here for the AGI buffer, we don't even need
2827 * to hold it locked to read the initial unlinked bucket entries out of
2828 * the buffer. We keep buffer reference though, so that it stays pinned
2829 * in memory while we need the buffer.
2831 agi = agibp->b_addr;
2832 xfs_buf_unlock(agibp);
2834 for (bucket = 0; bucket < XFS_AGI_UNLINKED_BUCKETS; bucket++) {
2835 error = xlog_recover_iunlink_bucket(pag, agi, bucket);
2838 * Bucket is unrecoverable, so only a repair scan can
2839 * free the remaining unlinked inodes. Just empty the
2840 * bucket and remaining inodes on it unreferenced and
2843 xlog_recover_clear_agi_bucket(pag, bucket);
2847 xfs_buf_rele(agibp);
2851 xlog_recover_process_iunlinks(
2854 struct xfs_perag *pag = NULL;
2856 while ((pag = xfs_perag_next(log->l_mp, pag)))
2857 xlog_recover_iunlink_ag(pag);
2862 struct xlog_rec_header *rhead,
2868 for (i = 0; i < BTOBB(be32_to_cpu(rhead->h_len)) &&
2869 i < (XLOG_HEADER_CYCLE_SIZE / BBSIZE); i++) {
2870 *(__be32 *)dp = *(__be32 *)&rhead->h_cycle_data[i];
2874 if (xfs_has_logv2(log->l_mp)) {
2875 xlog_in_core_2_t *xhdr = (xlog_in_core_2_t *)rhead;
2876 for ( ; i < BTOBB(be32_to_cpu(rhead->h_len)); i++) {
2877 j = i / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
2878 k = i % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
2879 *(__be32 *)dp = xhdr[j].hic_xheader.xh_cycle_data[k];
2886 * CRC check, unpack and process a log record.
2889 xlog_recover_process(
2891 struct hlist_head rhash[],
2892 struct xlog_rec_header *rhead,
2895 struct list_head *buffer_list)
2897 __le32 old_crc = rhead->h_crc;
2900 crc = xlog_cksum(log, rhead, dp, be32_to_cpu(rhead->h_len));
2903 * Nothing else to do if this is a CRC verification pass. Just return
2904 * if this a record with a non-zero crc. Unfortunately, mkfs always
2905 * sets old_crc to 0 so we must consider this valid even on v5 supers.
2906 * Otherwise, return EFSBADCRC on failure so the callers up the stack
2907 * know precisely what failed.
2909 if (pass == XLOG_RECOVER_CRCPASS) {
2910 if (old_crc && crc != old_crc)
2916 * We're in the normal recovery path. Issue a warning if and only if the
2917 * CRC in the header is non-zero. This is an advisory warning and the
2918 * zero CRC check prevents warnings from being emitted when upgrading
2919 * the kernel from one that does not add CRCs by default.
2921 if (crc != old_crc) {
2922 if (old_crc || xfs_has_crc(log->l_mp)) {
2923 xfs_alert(log->l_mp,
2924 "log record CRC mismatch: found 0x%x, expected 0x%x.",
2925 le32_to_cpu(old_crc),
2927 xfs_hex_dump(dp, 32);
2931 * If the filesystem is CRC enabled, this mismatch becomes a
2932 * fatal log corruption failure.
2934 if (xfs_has_crc(log->l_mp)) {
2935 XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, log->l_mp);
2936 return -EFSCORRUPTED;
2940 xlog_unpack_data(rhead, dp, log);
2942 return xlog_recover_process_data(log, rhash, rhead, dp, pass,
2947 xlog_valid_rec_header(
2949 struct xlog_rec_header *rhead,
2955 if (XFS_IS_CORRUPT(log->l_mp,
2956 rhead->h_magicno != cpu_to_be32(XLOG_HEADER_MAGIC_NUM)))
2957 return -EFSCORRUPTED;
2958 if (XFS_IS_CORRUPT(log->l_mp,
2959 (!rhead->h_version ||
2960 (be32_to_cpu(rhead->h_version) &
2961 (~XLOG_VERSION_OKBITS))))) {
2962 xfs_warn(log->l_mp, "%s: unrecognised log version (%d).",
2963 __func__, be32_to_cpu(rhead->h_version));
2964 return -EFSCORRUPTED;
2968 * LR body must have data (or it wouldn't have been written)
2969 * and h_len must not be greater than LR buffer size.
2971 hlen = be32_to_cpu(rhead->h_len);
2972 if (XFS_IS_CORRUPT(log->l_mp, hlen <= 0 || hlen > bufsize))
2973 return -EFSCORRUPTED;
2975 if (XFS_IS_CORRUPT(log->l_mp,
2976 blkno > log->l_logBBsize || blkno > INT_MAX))
2977 return -EFSCORRUPTED;
2982 * Read the log from tail to head and process the log records found.
2983 * Handle the two cases where the tail and head are in the same cycle
2984 * and where the active portion of the log wraps around the end of
2985 * the physical log separately. The pass parameter is passed through
2986 * to the routines called to process the data and is not looked at
2990 xlog_do_recovery_pass(
2992 xfs_daddr_t head_blk,
2993 xfs_daddr_t tail_blk,
2995 xfs_daddr_t *first_bad) /* out: first bad log rec */
2997 xlog_rec_header_t *rhead;
2998 xfs_daddr_t blk_no, rblk_no;
2999 xfs_daddr_t rhead_blk;
3002 int error = 0, h_size, h_len;
3004 int bblks, split_bblks;
3005 int hblks = 1, split_hblks, wrapped_hblks;
3007 struct hlist_head rhash[XLOG_RHASH_SIZE];
3008 LIST_HEAD (buffer_list);
3010 ASSERT(head_blk != tail_blk);
3011 blk_no = rhead_blk = tail_blk;
3013 for (i = 0; i < XLOG_RHASH_SIZE; i++)
3014 INIT_HLIST_HEAD(&rhash[i]);
3016 hbp = xlog_alloc_buffer(log, hblks);
3021 * Read the header of the tail block and get the iclog buffer size from
3022 * h_size. Use this to tell how many sectors make up the log header.
3024 if (xfs_has_logv2(log->l_mp)) {
3026 * When using variable length iclogs, read first sector of
3027 * iclog header and extract the header size from it. Get a
3028 * new hbp that is the correct size.
3030 error = xlog_bread(log, tail_blk, 1, hbp, &offset);
3034 rhead = (xlog_rec_header_t *)offset;
3037 * xfsprogs has a bug where record length is based on lsunit but
3038 * h_size (iclog size) is hardcoded to 32k. Now that we
3039 * unconditionally CRC verify the unmount record, this means the
3040 * log buffer can be too small for the record and cause an
3043 * Detect this condition here. Use lsunit for the buffer size as
3044 * long as this looks like the mkfs case. Otherwise, return an
3045 * error to avoid a buffer overrun.
3047 h_size = be32_to_cpu(rhead->h_size);
3048 h_len = be32_to_cpu(rhead->h_len);
3049 if (h_len > h_size && h_len <= log->l_mp->m_logbsize &&
3050 rhead->h_num_logops == cpu_to_be32(1)) {
3052 "invalid iclog size (%d bytes), using lsunit (%d bytes)",
3053 h_size, log->l_mp->m_logbsize);
3054 h_size = log->l_mp->m_logbsize;
3057 error = xlog_valid_rec_header(log, rhead, tail_blk, h_size);
3062 * This open codes xlog_logrec_hblks so that we can reuse the
3063 * fixed up h_size value calculated above. Without that we'd
3064 * still allocate the buffer based on the incorrect on-disk
3067 if (h_size > XLOG_HEADER_CYCLE_SIZE &&
3068 (rhead->h_version & cpu_to_be32(XLOG_VERSION_2))) {
3069 hblks = DIV_ROUND_UP(h_size, XLOG_HEADER_CYCLE_SIZE);
3072 hbp = xlog_alloc_buffer(log, hblks);
3078 ASSERT(log->l_sectBBsize == 1);
3079 h_size = XLOG_BIG_RECORD_BSIZE;
3082 dbp = xlog_alloc_buffer(log, BTOBB(h_size));
3088 memset(rhash, 0, sizeof(rhash));
3089 if (tail_blk > head_blk) {
3091 * Perform recovery around the end of the physical log.
3092 * When the head is not on the same cycle number as the tail,
3093 * we can't do a sequential recovery.
3095 while (blk_no < log->l_logBBsize) {
3097 * Check for header wrapping around physical end-of-log
3102 if (blk_no + hblks <= log->l_logBBsize) {
3103 /* Read header in one read */
3104 error = xlog_bread(log, blk_no, hblks, hbp,
3109 /* This LR is split across physical log end */
3110 if (blk_no != log->l_logBBsize) {
3111 /* some data before physical log end */
3112 ASSERT(blk_no <= INT_MAX);
3113 split_hblks = log->l_logBBsize - (int)blk_no;
3114 ASSERT(split_hblks > 0);
3115 error = xlog_bread(log, blk_no,
3123 * Note: this black magic still works with
3124 * large sector sizes (non-512) only because:
3125 * - we increased the buffer size originally
3126 * by 1 sector giving us enough extra space
3127 * for the second read;
3128 * - the log start is guaranteed to be sector
3130 * - we read the log end (LR header start)
3131 * _first_, then the log start (LR header end)
3132 * - order is important.
3134 wrapped_hblks = hblks - split_hblks;
3135 error = xlog_bread_noalign(log, 0,
3137 offset + BBTOB(split_hblks));
3141 rhead = (xlog_rec_header_t *)offset;
3142 error = xlog_valid_rec_header(log, rhead,
3143 split_hblks ? blk_no : 0, h_size);
3147 bblks = (int)BTOBB(be32_to_cpu(rhead->h_len));
3151 * Read the log record data in multiple reads if it
3152 * wraps around the end of the log. Note that if the
3153 * header already wrapped, blk_no could point past the
3154 * end of the log. The record data is contiguous in
3157 if (blk_no + bblks <= log->l_logBBsize ||
3158 blk_no >= log->l_logBBsize) {
3159 rblk_no = xlog_wrap_logbno(log, blk_no);
3160 error = xlog_bread(log, rblk_no, bblks, dbp,
3165 /* This log record is split across the
3166 * physical end of log */
3169 if (blk_no != log->l_logBBsize) {
3170 /* some data is before the physical
3172 ASSERT(!wrapped_hblks);
3173 ASSERT(blk_no <= INT_MAX);
3175 log->l_logBBsize - (int)blk_no;
3176 ASSERT(split_bblks > 0);
3177 error = xlog_bread(log, blk_no,
3185 * Note: this black magic still works with
3186 * large sector sizes (non-512) only because:
3187 * - we increased the buffer size originally
3188 * by 1 sector giving us enough extra space
3189 * for the second read;
3190 * - the log start is guaranteed to be sector
3192 * - we read the log end (LR header start)
3193 * _first_, then the log start (LR header end)
3194 * - order is important.
3196 error = xlog_bread_noalign(log, 0,
3197 bblks - split_bblks,
3198 offset + BBTOB(split_bblks));
3203 error = xlog_recover_process(log, rhash, rhead, offset,
3204 pass, &buffer_list);
3212 ASSERT(blk_no >= log->l_logBBsize);
3213 blk_no -= log->l_logBBsize;
3217 /* read first part of physical log */
3218 while (blk_no < head_blk) {
3219 error = xlog_bread(log, blk_no, hblks, hbp, &offset);
3223 rhead = (xlog_rec_header_t *)offset;
3224 error = xlog_valid_rec_header(log, rhead, blk_no, h_size);
3228 /* blocks in data section */
3229 bblks = (int)BTOBB(be32_to_cpu(rhead->h_len));
3230 error = xlog_bread(log, blk_no+hblks, bblks, dbp,
3235 error = xlog_recover_process(log, rhash, rhead, offset, pass,
3240 blk_no += bblks + hblks;
3250 * Submit buffers that have been dirtied by the last record recovered.
3252 if (!list_empty(&buffer_list)) {
3255 * If there has been an item recovery error then we
3256 * cannot allow partial checkpoint writeback to
3257 * occur. We might have multiple checkpoints with the
3258 * same start LSN in this buffer list, and partial
3259 * writeback of a checkpoint in this situation can
3260 * prevent future recovery of all the changes in the
3261 * checkpoints at this start LSN.
3263 * Note: Shutting down the filesystem will result in the
3264 * delwri submission marking all the buffers stale,
3265 * completing them and cleaning up _XBF_LOGRECOVERY
3266 * state without doing any IO.
3268 xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR);
3270 error2 = xfs_buf_delwri_submit(&buffer_list);
3273 if (error && first_bad)
3274 *first_bad = rhead_blk;
3277 * Transactions are freed at commit time but transactions without commit
3278 * records on disk are never committed. Free any that may be left in the
3281 for (i = 0; i < XLOG_RHASH_SIZE; i++) {
3282 struct hlist_node *tmp;
3283 struct xlog_recover *trans;
3285 hlist_for_each_entry_safe(trans, tmp, &rhash[i], r_list)
3286 xlog_recover_free_trans(trans);
3289 return error ? error : error2;
3293 * Do the recovery of the log. We actually do this in two phases.
3294 * The two passes are necessary in order to implement the function
3295 * of cancelling a record written into the log. The first pass
3296 * determines those things which have been cancelled, and the
3297 * second pass replays log items normally except for those which
3298 * have been cancelled. The handling of the replay and cancellations
3299 * takes place in the log item type specific routines.
3301 * The table of items which have cancel records in the log is allocated
3302 * and freed at this level, since only here do we know when all of
3303 * the log recovery has been completed.
3306 xlog_do_log_recovery(
3308 xfs_daddr_t head_blk,
3309 xfs_daddr_t tail_blk)
3313 ASSERT(head_blk != tail_blk);
3316 * First do a pass to find all of the cancelled buf log items.
3317 * Store them in the buf_cancel_table for use in the second pass.
3319 error = xlog_alloc_buf_cancel_table(log);
3323 error = xlog_do_recovery_pass(log, head_blk, tail_blk,
3324 XLOG_RECOVER_PASS1, NULL);
3329 * Then do a second pass to actually recover the items in the log.
3330 * When it is complete free the table of buf cancel items.
3332 error = xlog_do_recovery_pass(log, head_blk, tail_blk,
3333 XLOG_RECOVER_PASS2, NULL);
3335 xlog_check_buf_cancel_table(log);
3337 xlog_free_buf_cancel_table(log);
3342 * Do the actual recovery
3347 xfs_daddr_t head_blk,
3348 xfs_daddr_t tail_blk)
3350 struct xfs_mount *mp = log->l_mp;
3351 struct xfs_buf *bp = mp->m_sb_bp;
3352 struct xfs_sb *sbp = &mp->m_sb;
3355 trace_xfs_log_recover(log, head_blk, tail_blk);
3358 * First replay the images in the log.
3360 error = xlog_do_log_recovery(log, head_blk, tail_blk);
3364 if (xlog_is_shutdown(log))
3368 * We now update the tail_lsn since much of the recovery has completed
3369 * and there may be space available to use. If there were no extent or
3370 * iunlinks, we can free up the entire log. This was set in
3371 * xlog_find_tail to be the lsn of the last known good LR on disk. If
3372 * there are extent frees or iunlinks they will have some entries in the
3373 * AIL; so we look at the AIL to determine how to set the tail_lsn.
3375 xfs_ail_assign_tail_lsn(log->l_ailp);
3378 * Now that we've finished replaying all buffer and inode updates,
3379 * re-read the superblock and reverify it.
3383 error = _xfs_buf_read(bp);
3385 if (!xlog_is_shutdown(log)) {
3386 xfs_buf_ioerror_alert(bp, __this_address);
3393 /* Convert superblock from on-disk format */
3394 xfs_sb_from_disk(sbp, bp->b_addr);
3397 /* re-initialise in-core superblock and geometry structures */
3398 mp->m_features |= xfs_sb_version_to_features(sbp);
3399 xfs_reinit_percpu_counters(mp);
3401 /* Normal transactions can now occur */
3402 clear_bit(XLOG_ACTIVE_RECOVERY, &log->l_opstate);
3407 * Perform recovery and re-initialize some log variables in xlog_find_tail.
3409 * Return error or zero.
3415 xfs_daddr_t head_blk, tail_blk;
3418 /* find the tail of the log */
3419 error = xlog_find_tail(log, &head_blk, &tail_blk);
3424 * The superblock was read before the log was available and thus the LSN
3425 * could not be verified. Check the superblock LSN against the current
3426 * LSN now that it's known.
3428 if (xfs_has_crc(log->l_mp) &&
3429 !xfs_log_check_lsn(log->l_mp, log->l_mp->m_sb.sb_lsn))
3432 if (tail_blk != head_blk) {
3433 /* There used to be a comment here:
3435 * disallow recovery on read-only mounts. note -- mount
3436 * checks for ENOSPC and turns it into an intelligent
3438 * ...but this is no longer true. Now, unless you specify
3439 * NORECOVERY (in which case this function would never be
3440 * called), we just go ahead and recover. We do this all
3441 * under the vfs layer, so we can get away with it unless
3442 * the device itself is read-only, in which case we fail.
3444 if ((error = xfs_dev_is_read_only(log->l_mp, "recovery"))) {
3449 * Version 5 superblock log feature mask validation. We know the
3450 * log is dirty so check if there are any unknown log features
3451 * in what we need to recover. If there are unknown features
3452 * (e.g. unsupported transactions, then simply reject the
3453 * attempt at recovery before touching anything.
3455 if (xfs_sb_is_v5(&log->l_mp->m_sb) &&
3456 xfs_sb_has_incompat_log_feature(&log->l_mp->m_sb,
3457 XFS_SB_FEAT_INCOMPAT_LOG_UNKNOWN)) {
3459 "Superblock has unknown incompatible log features (0x%x) enabled.",
3460 (log->l_mp->m_sb.sb_features_log_incompat &
3461 XFS_SB_FEAT_INCOMPAT_LOG_UNKNOWN));
3463 "The log can not be fully and/or safely recovered by this kernel.");
3465 "Please recover the log on a kernel that supports the unknown features.");
3470 * Delay log recovery if the debug hook is set. This is debug
3471 * instrumentation to coordinate simulation of I/O failures with
3474 if (xfs_globals.log_recovery_delay) {
3475 xfs_notice(log->l_mp,
3476 "Delaying log recovery for %d seconds.",
3477 xfs_globals.log_recovery_delay);
3478 msleep(xfs_globals.log_recovery_delay * 1000);
3481 xfs_notice(log->l_mp, "Starting recovery (logdev: %s)",
3482 log->l_mp->m_logname ? log->l_mp->m_logname
3485 error = xlog_do_recover(log, head_blk, tail_blk);
3486 set_bit(XLOG_RECOVERY_NEEDED, &log->l_opstate);
3492 * In the first part of recovery we replay inodes and buffers and build up the
3493 * list of intents which need to be processed. Here we process the intents and
3494 * clean up the on disk unlinked inode lists. This is separated from the first
3495 * part of recovery so that the root and real-time bitmap inodes can be read in
3496 * from disk in between the two stages. This is necessary so that we can free
3497 * space in the real-time portion of the file system.
3499 * We run this whole process under GFP_NOFS allocation context. We do a
3500 * combination of non-transactional and transactional work, yet we really don't
3501 * want to recurse into the filesystem from direct reclaim during any of this
3502 * processing. This allows all the recovery code run here not to care about the
3503 * memory allocation context it is running in.
3506 xlog_recover_finish(
3509 unsigned int nofs_flags = memalloc_nofs_save();
3512 error = xlog_recover_process_intents(log);
3515 * Cancel all the unprocessed intent items now so that we don't
3516 * leave them pinned in the AIL. This can cause the AIL to
3517 * livelock on the pinned item if anyone tries to push the AIL
3518 * (inode reclaim does this) before we get around to
3519 * xfs_log_mount_cancel.
3521 xlog_recover_cancel_intents(log);
3522 xfs_alert(log->l_mp, "Failed to recover intents");
3523 xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR);
3528 * Sync the log to get all the intents out of the AIL. This isn't
3529 * absolutely necessary, but it helps in case the unlink transactions
3530 * would have problems pushing the intents out of the way.
3532 xfs_log_force(log->l_mp, XFS_LOG_SYNC);
3534 xlog_recover_process_iunlinks(log);
3537 * Recover any CoW staging blocks that are still referenced by the
3538 * ondisk refcount metadata. During mount there cannot be any live
3539 * staging extents as we have not permitted any user modifications.
3540 * Therefore, it is safe to free them all right now, even on a
3543 error = xfs_reflink_recover_cow(log->l_mp);
3545 xfs_alert(log->l_mp,
3546 "Failed to recover leftover CoW staging extents, err %d.",
3549 * If we get an error here, make sure the log is shut down
3550 * but return zero so that any log items committed since the
3551 * end of intents processing can be pushed through the CIL
3554 xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR);
3560 memalloc_nofs_restore(nofs_flags);
3565 xlog_recover_cancel(
3568 if (xlog_recovery_needed(log))
3569 xlog_recover_cancel_intents(log);
projects / linux-2.6-block.git / blob