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 = 1 << ffs(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);
1049 kmem_free(tmp_buffer);
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 xlog_assign_atomic_lsn(&log->l_last_sync_lsn,
1181 log->l_curr_cycle, after_umount_blk);
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 atomic64_set(&log->l_last_sync_lsn, be64_to_cpu(rhead->h_lsn));
1216 xlog_assign_grant_head(&log->l_reserve_head.grant, log->l_curr_cycle,
1217 BBTOB(log->l_curr_block));
1218 xlog_assign_grant_head(&log->l_write_head.grant, log->l_curr_cycle,
1219 BBTOB(log->l_curr_block));
1223 * Find the sync block number or the tail of the log.
1225 * This will be the block number of the last record to have its
1226 * associated buffers synced to disk. Every log record header has
1227 * a sync lsn embedded in it. LSNs hold block numbers, so it is easy
1228 * to get a sync block number. The only concern is to figure out which
1229 * log record header to believe.
1231 * The following algorithm uses the log record header with the largest
1232 * lsn. The entire log record does not need to be valid. We only care
1233 * that the header is valid.
1235 * We could speed up search by using current head_blk buffer, but it is not
1241 xfs_daddr_t *head_blk,
1242 xfs_daddr_t *tail_blk)
1244 xlog_rec_header_t *rhead;
1245 char *offset = NULL;
1248 xfs_daddr_t rhead_blk;
1250 bool wrapped = false;
1254 * Find previous log record
1256 if ((error = xlog_find_head(log, head_blk)))
1258 ASSERT(*head_blk < INT_MAX);
1260 buffer = xlog_alloc_buffer(log, 1);
1263 if (*head_blk == 0) { /* special case */
1264 error = xlog_bread(log, 0, 1, buffer, &offset);
1268 if (xlog_get_cycle(offset) == 0) {
1270 /* leave all other log inited values alone */
1276 * Search backwards through the log looking for the log record header
1277 * block. This wraps all the way back around to the head so something is
1278 * seriously wrong if we can't find it.
1280 error = xlog_rseek_logrec_hdr(log, *head_blk, *head_blk, 1, buffer,
1281 &rhead_blk, &rhead, &wrapped);
1285 xfs_warn(log->l_mp, "%s: couldn't find sync record", __func__);
1286 error = -EFSCORRUPTED;
1289 *tail_blk = BLOCK_LSN(be64_to_cpu(rhead->h_tail_lsn));
1292 * Set the log state based on the current head record.
1294 xlog_set_state(log, *head_blk, rhead, rhead_blk, wrapped);
1295 tail_lsn = atomic64_read(&log->l_tail_lsn);
1298 * Look for an unmount record at the head of the log. This sets the log
1299 * state to determine whether recovery is necessary.
1301 error = xlog_check_unmount_rec(log, head_blk, tail_blk, rhead,
1302 rhead_blk, buffer, &clean);
1307 * Verify the log head if the log is not clean (e.g., we have anything
1308 * but an unmount record at the head). This uses CRC verification to
1309 * detect and trim torn writes. If discovered, CRC failures are
1310 * considered torn writes and the log head is trimmed accordingly.
1312 * Note that we can only run CRC verification when the log is dirty
1313 * because there's no guarantee that the log data behind an unmount
1314 * record is compatible with the current architecture.
1317 xfs_daddr_t orig_head = *head_blk;
1319 error = xlog_verify_head(log, head_blk, tail_blk, buffer,
1320 &rhead_blk, &rhead, &wrapped);
1324 /* update in-core state again if the head changed */
1325 if (*head_blk != orig_head) {
1326 xlog_set_state(log, *head_blk, rhead, rhead_blk,
1328 tail_lsn = atomic64_read(&log->l_tail_lsn);
1329 error = xlog_check_unmount_rec(log, head_blk, tail_blk,
1330 rhead, rhead_blk, buffer,
1338 * Note that the unmount was clean. If the unmount was not clean, we
1339 * need to know this to rebuild the superblock counters from the perag
1340 * headers if we have a filesystem using non-persistent counters.
1343 set_bit(XFS_OPSTATE_CLEAN, &log->l_mp->m_opstate);
1346 * Make sure that there are no blocks in front of the head
1347 * with the same cycle number as the head. This can happen
1348 * because we allow multiple outstanding log writes concurrently,
1349 * and the later writes might make it out before earlier ones.
1351 * We use the lsn from before modifying it so that we'll never
1352 * overwrite the unmount record after a clean unmount.
1354 * Do this only if we are going to recover the filesystem
1356 * NOTE: This used to say "if (!readonly)"
1357 * However on Linux, we can & do recover a read-only filesystem.
1358 * We only skip recovery if NORECOVERY is specified on mount,
1359 * in which case we would not be here.
1361 * But... if the -device- itself is readonly, just skip this.
1362 * We can't recover this device anyway, so it won't matter.
1364 if (!xfs_readonly_buftarg(log->l_targ))
1365 error = xlog_clear_stale_blocks(log, tail_lsn);
1371 xfs_warn(log->l_mp, "failed to locate log tail");
1376 * Is the log zeroed at all?
1378 * The last binary search should be changed to perform an X block read
1379 * once X becomes small enough. You can then search linearly through
1380 * the X blocks. This will cut down on the number of reads we need to do.
1382 * If the log is partially zeroed, this routine will pass back the blkno
1383 * of the first block with cycle number 0. It won't have a complete LR
1387 * 0 => the log is completely written to
1388 * 1 => use *blk_no as the first block of the log
1389 * <0 => error has occurred
1394 xfs_daddr_t *blk_no)
1398 uint first_cycle, last_cycle;
1399 xfs_daddr_t new_blk, last_blk, start_blk;
1400 xfs_daddr_t num_scan_bblks;
1401 int error, log_bbnum = log->l_logBBsize;
1405 /* check totally zeroed log */
1406 buffer = xlog_alloc_buffer(log, 1);
1409 error = xlog_bread(log, 0, 1, buffer, &offset);
1411 goto out_free_buffer;
1413 first_cycle = xlog_get_cycle(offset);
1414 if (first_cycle == 0) { /* completely zeroed log */
1420 /* check partially zeroed log */
1421 error = xlog_bread(log, log_bbnum-1, 1, buffer, &offset);
1423 goto out_free_buffer;
1425 last_cycle = xlog_get_cycle(offset);
1426 if (last_cycle != 0) { /* log completely written to */
1431 /* we have a partially zeroed log */
1432 last_blk = log_bbnum-1;
1433 error = xlog_find_cycle_start(log, buffer, 0, &last_blk, 0);
1435 goto out_free_buffer;
1438 * Validate the answer. Because there is no way to guarantee that
1439 * the entire log is made up of log records which are the same size,
1440 * we scan over the defined maximum blocks. At this point, the maximum
1441 * is not chosen to mean anything special. XXXmiken
1443 num_scan_bblks = XLOG_TOTAL_REC_SHIFT(log);
1444 ASSERT(num_scan_bblks <= INT_MAX);
1446 if (last_blk < num_scan_bblks)
1447 num_scan_bblks = last_blk;
1448 start_blk = last_blk - num_scan_bblks;
1451 * We search for any instances of cycle number 0 that occur before
1452 * our current estimate of the head. What we're trying to detect is
1453 * 1 ... | 0 | 1 | 0...
1454 * ^ binary search ends here
1456 if ((error = xlog_find_verify_cycle(log, start_blk,
1457 (int)num_scan_bblks, 0, &new_blk)))
1458 goto out_free_buffer;
1463 * Potentially backup over partial log record write. We don't need
1464 * to search the end of the log because we know it is zero.
1466 error = xlog_find_verify_log_record(log, start_blk, &last_blk, 0);
1470 goto out_free_buffer;
1481 * These are simple subroutines used by xlog_clear_stale_blocks() below
1482 * to initialize a buffer full of empty log record headers and write
1483 * them into the log.
1494 xlog_rec_header_t *recp = (xlog_rec_header_t *)buf;
1496 memset(buf, 0, BBSIZE);
1497 recp->h_magicno = cpu_to_be32(XLOG_HEADER_MAGIC_NUM);
1498 recp->h_cycle = cpu_to_be32(cycle);
1499 recp->h_version = cpu_to_be32(
1500 xfs_has_logv2(log->l_mp) ? 2 : 1);
1501 recp->h_lsn = cpu_to_be64(xlog_assign_lsn(cycle, block));
1502 recp->h_tail_lsn = cpu_to_be64(xlog_assign_lsn(tail_cycle, tail_block));
1503 recp->h_fmt = cpu_to_be32(XLOG_FMT);
1504 memcpy(&recp->h_fs_uuid, &log->l_mp->m_sb.sb_uuid, sizeof(uuid_t));
1508 xlog_write_log_records(
1519 int sectbb = log->l_sectBBsize;
1520 int end_block = start_block + blocks;
1526 * Greedily allocate a buffer big enough to handle the full
1527 * range of basic blocks to be written. If that fails, try
1528 * a smaller size. We need to be able to write at least a
1529 * log sector, or we're out of luck.
1531 bufblks = 1 << ffs(blocks);
1532 while (bufblks > log->l_logBBsize)
1534 while (!(buffer = xlog_alloc_buffer(log, bufblks))) {
1536 if (bufblks < sectbb)
1540 /* We may need to do a read at the start to fill in part of
1541 * the buffer in the starting sector not covered by the first
1544 balign = round_down(start_block, sectbb);
1545 if (balign != start_block) {
1546 error = xlog_bread_noalign(log, start_block, 1, buffer);
1548 goto out_free_buffer;
1550 j = start_block - balign;
1553 for (i = start_block; i < end_block; i += bufblks) {
1554 int bcount, endcount;
1556 bcount = min(bufblks, end_block - start_block);
1557 endcount = bcount - j;
1559 /* We may need to do a read at the end to fill in part of
1560 * the buffer in the final sector not covered by the write.
1561 * If this is the same sector as the above read, skip it.
1563 ealign = round_down(end_block, sectbb);
1564 if (j == 0 && (start_block + endcount > ealign)) {
1565 error = xlog_bread_noalign(log, ealign, sectbb,
1566 buffer + BBTOB(ealign - start_block));
1572 offset = buffer + xlog_align(log, start_block);
1573 for (; j < endcount; j++) {
1574 xlog_add_record(log, offset, cycle, i+j,
1575 tail_cycle, tail_block);
1578 error = xlog_bwrite(log, start_block, endcount, buffer);
1581 start_block += endcount;
1591 * This routine is called to blow away any incomplete log writes out
1592 * in front of the log head. We do this so that we won't become confused
1593 * if we come up, write only a little bit more, and then crash again.
1594 * If we leave the partial log records out there, this situation could
1595 * cause us to think those partial writes are valid blocks since they
1596 * have the current cycle number. We get rid of them by overwriting them
1597 * with empty log records with the old cycle number rather than the
1600 * The tail lsn is passed in rather than taken from
1601 * the log so that we will not write over the unmount record after a
1602 * clean unmount in a 512 block log. Doing so would leave the log without
1603 * any valid log records in it until a new one was written. If we crashed
1604 * during that time we would not be able to recover.
1607 xlog_clear_stale_blocks(
1611 int tail_cycle, head_cycle;
1612 int tail_block, head_block;
1613 int tail_distance, max_distance;
1617 tail_cycle = CYCLE_LSN(tail_lsn);
1618 tail_block = BLOCK_LSN(tail_lsn);
1619 head_cycle = log->l_curr_cycle;
1620 head_block = log->l_curr_block;
1623 * Figure out the distance between the new head of the log
1624 * and the tail. We want to write over any blocks beyond the
1625 * head that we may have written just before the crash, but
1626 * we don't want to overwrite the tail of the log.
1628 if (head_cycle == tail_cycle) {
1630 * The tail is behind the head in the physical log,
1631 * so the distance from the head to the tail is the
1632 * distance from the head to the end of the log plus
1633 * the distance from the beginning of the log to the
1636 if (XFS_IS_CORRUPT(log->l_mp,
1637 head_block < tail_block ||
1638 head_block >= log->l_logBBsize))
1639 return -EFSCORRUPTED;
1640 tail_distance = tail_block + (log->l_logBBsize - head_block);
1643 * The head is behind the tail in the physical log,
1644 * so the distance from the head to the tail is just
1645 * the tail block minus the head block.
1647 if (XFS_IS_CORRUPT(log->l_mp,
1648 head_block >= tail_block ||
1649 head_cycle != tail_cycle + 1))
1650 return -EFSCORRUPTED;
1651 tail_distance = tail_block - head_block;
1655 * If the head is right up against the tail, we can't clear
1658 if (tail_distance <= 0) {
1659 ASSERT(tail_distance == 0);
1663 max_distance = XLOG_TOTAL_REC_SHIFT(log);
1665 * Take the smaller of the maximum amount of outstanding I/O
1666 * we could have and the distance to the tail to clear out.
1667 * We take the smaller so that we don't overwrite the tail and
1668 * we don't waste all day writing from the head to the tail
1671 max_distance = min(max_distance, tail_distance);
1673 if ((head_block + max_distance) <= log->l_logBBsize) {
1675 * We can stomp all the blocks we need to without
1676 * wrapping around the end of the log. Just do it
1677 * in a single write. Use the cycle number of the
1678 * current cycle minus one so that the log will look like:
1681 error = xlog_write_log_records(log, (head_cycle - 1),
1682 head_block, max_distance, tail_cycle,
1688 * We need to wrap around the end of the physical log in
1689 * order to clear all the blocks. Do it in two separate
1690 * I/Os. The first write should be from the head to the
1691 * end of the physical log, and it should use the current
1692 * cycle number minus one just like above.
1694 distance = log->l_logBBsize - head_block;
1695 error = xlog_write_log_records(log, (head_cycle - 1),
1696 head_block, distance, tail_cycle,
1703 * Now write the blocks at the start of the physical log.
1704 * This writes the remainder of the blocks we want to clear.
1705 * It uses the current cycle number since we're now on the
1706 * same cycle as the head so that we get:
1707 * n ... n ... | n - 1 ...
1708 * ^^^^^ blocks we're writing
1710 distance = max_distance - (log->l_logBBsize - head_block);
1711 error = xlog_write_log_records(log, head_cycle, 0, distance,
1712 tail_cycle, tail_block);
1721 * Release the recovered intent item in the AIL that matches the given intent
1722 * type and intent id.
1725 xlog_recover_release_intent(
1727 unsigned short intent_type,
1730 struct xfs_ail_cursor cur;
1731 struct xfs_log_item *lip;
1732 struct xfs_ail *ailp = log->l_ailp;
1734 spin_lock(&ailp->ail_lock);
1735 for (lip = xfs_trans_ail_cursor_first(ailp, &cur, 0); lip != NULL;
1736 lip = xfs_trans_ail_cursor_next(ailp, &cur)) {
1737 if (lip->li_type != intent_type)
1739 if (!lip->li_ops->iop_match(lip, intent_id))
1742 spin_unlock(&ailp->ail_lock);
1743 lip->li_ops->iop_release(lip);
1744 spin_lock(&ailp->ail_lock);
1748 xfs_trans_ail_cursor_done(&cur);
1749 spin_unlock(&ailp->ail_lock);
1754 struct xfs_mount *mp,
1756 struct xfs_inode **ipp)
1760 error = xfs_iget(mp, NULL, ino, 0, 0, ipp);
1764 error = xfs_qm_dqattach(*ipp);
1770 if (VFS_I(*ipp)->i_nlink == 0)
1771 xfs_iflags_set(*ipp, XFS_IRECOVERY);
1776 /******************************************************************************
1778 * Log recover routines
1780 ******************************************************************************
1782 static const struct xlog_recover_item_ops *xlog_recover_item_ops[] = {
1784 &xlog_inode_item_ops,
1785 &xlog_dquot_item_ops,
1786 &xlog_quotaoff_item_ops,
1787 &xlog_icreate_item_ops,
1796 &xlog_attri_item_ops,
1797 &xlog_attrd_item_ops,
1800 static const struct xlog_recover_item_ops *
1802 struct xlog_recover_item *item)
1806 for (i = 0; i < ARRAY_SIZE(xlog_recover_item_ops); i++)
1807 if (ITEM_TYPE(item) == xlog_recover_item_ops[i]->item_type)
1808 return xlog_recover_item_ops[i];
1814 * Sort the log items in the transaction.
1816 * The ordering constraints are defined by the inode allocation and unlink
1817 * behaviour. The rules are:
1819 * 1. Every item is only logged once in a given transaction. Hence it
1820 * represents the last logged state of the item. Hence ordering is
1821 * dependent on the order in which operations need to be performed so
1822 * required initial conditions are always met.
1824 * 2. Cancelled buffers are recorded in pass 1 in a separate table and
1825 * there's nothing to replay from them so we can simply cull them
1826 * from the transaction. However, we can't do that until after we've
1827 * replayed all the other items because they may be dependent on the
1828 * cancelled buffer and replaying the cancelled buffer can remove it
1829 * form the cancelled buffer table. Hence they have tobe done last.
1831 * 3. Inode allocation buffers must be replayed before inode items that
1832 * read the buffer and replay changes into it. For filesystems using the
1833 * ICREATE transactions, this means XFS_LI_ICREATE objects need to get
1834 * treated the same as inode allocation buffers as they create and
1835 * initialise the buffers directly.
1837 * 4. Inode unlink buffers must be replayed after inode items are replayed.
1838 * This ensures that inodes are completely flushed to the inode buffer
1839 * in a "free" state before we remove the unlinked inode list pointer.
1841 * Hence the ordering needs to be inode allocation buffers first, inode items
1842 * second, inode unlink buffers third and cancelled buffers last.
1844 * But there's a problem with that - we can't tell an inode allocation buffer
1845 * apart from a regular buffer, so we can't separate them. We can, however,
1846 * tell an inode unlink buffer from the others, and so we can separate them out
1847 * from all the other buffers and move them to last.
1849 * Hence, 4 lists, in order from head to tail:
1850 * - buffer_list for all buffers except cancelled/inode unlink buffers
1851 * - item_list for all non-buffer items
1852 * - inode_buffer_list for inode unlink buffers
1853 * - cancel_list for the cancelled buffers
1855 * Note that we add objects to the tail of the lists so that first-to-last
1856 * ordering is preserved within the lists. Adding objects to the head of the
1857 * list means when we traverse from the head we walk them in last-to-first
1858 * order. For cancelled buffers and inode unlink buffers this doesn't matter,
1859 * but for all other items there may be specific ordering that we need to
1863 xlog_recover_reorder_trans(
1865 struct xlog_recover *trans,
1868 struct xlog_recover_item *item, *n;
1870 LIST_HEAD(sort_list);
1871 LIST_HEAD(cancel_list);
1872 LIST_HEAD(buffer_list);
1873 LIST_HEAD(inode_buffer_list);
1874 LIST_HEAD(item_list);
1876 list_splice_init(&trans->r_itemq, &sort_list);
1877 list_for_each_entry_safe(item, n, &sort_list, ri_list) {
1878 enum xlog_recover_reorder fate = XLOG_REORDER_ITEM_LIST;
1880 item->ri_ops = xlog_find_item_ops(item);
1881 if (!item->ri_ops) {
1883 "%s: unrecognized type of log operation (%d)",
1884 __func__, ITEM_TYPE(item));
1887 * return the remaining items back to the transaction
1888 * item list so they can be freed in caller.
1890 if (!list_empty(&sort_list))
1891 list_splice_init(&sort_list, &trans->r_itemq);
1892 error = -EFSCORRUPTED;
1896 if (item->ri_ops->reorder)
1897 fate = item->ri_ops->reorder(item);
1900 case XLOG_REORDER_BUFFER_LIST:
1901 list_move_tail(&item->ri_list, &buffer_list);
1903 case XLOG_REORDER_CANCEL_LIST:
1904 trace_xfs_log_recover_item_reorder_head(log,
1906 list_move(&item->ri_list, &cancel_list);
1908 case XLOG_REORDER_INODE_BUFFER_LIST:
1909 list_move(&item->ri_list, &inode_buffer_list);
1911 case XLOG_REORDER_ITEM_LIST:
1912 trace_xfs_log_recover_item_reorder_tail(log,
1914 list_move_tail(&item->ri_list, &item_list);
1919 ASSERT(list_empty(&sort_list));
1920 if (!list_empty(&buffer_list))
1921 list_splice(&buffer_list, &trans->r_itemq);
1922 if (!list_empty(&item_list))
1923 list_splice_tail(&item_list, &trans->r_itemq);
1924 if (!list_empty(&inode_buffer_list))
1925 list_splice_tail(&inode_buffer_list, &trans->r_itemq);
1926 if (!list_empty(&cancel_list))
1927 list_splice_tail(&cancel_list, &trans->r_itemq);
1936 const struct xfs_buf_ops *ops)
1938 if (!xlog_is_buffer_cancelled(log, blkno, len))
1939 xfs_buf_readahead(log->l_mp->m_ddev_targp, blkno, len, ops);
1943 xlog_recover_items_pass2(
1945 struct xlog_recover *trans,
1946 struct list_head *buffer_list,
1947 struct list_head *item_list)
1949 struct xlog_recover_item *item;
1952 list_for_each_entry(item, item_list, ri_list) {
1953 trace_xfs_log_recover_item_recover(log, trans, item,
1954 XLOG_RECOVER_PASS2);
1956 if (item->ri_ops->commit_pass2)
1957 error = item->ri_ops->commit_pass2(log, buffer_list,
1958 item, trans->r_lsn);
1967 * Perform the transaction.
1969 * If the transaction modifies a buffer or inode, do it now. Otherwise,
1970 * EFIs and EFDs get queued up by adding entries into the AIL for them.
1973 xlog_recover_commit_trans(
1975 struct xlog_recover *trans,
1977 struct list_head *buffer_list)
1980 int items_queued = 0;
1981 struct xlog_recover_item *item;
1982 struct xlog_recover_item *next;
1983 LIST_HEAD (ra_list);
1984 LIST_HEAD (done_list);
1986 #define XLOG_RECOVER_COMMIT_QUEUE_MAX 100
1988 hlist_del_init(&trans->r_list);
1990 error = xlog_recover_reorder_trans(log, trans, pass);
1994 list_for_each_entry_safe(item, next, &trans->r_itemq, ri_list) {
1995 trace_xfs_log_recover_item_recover(log, trans, item, pass);
1998 case XLOG_RECOVER_PASS1:
1999 if (item->ri_ops->commit_pass1)
2000 error = item->ri_ops->commit_pass1(log, item);
2002 case XLOG_RECOVER_PASS2:
2003 if (item->ri_ops->ra_pass2)
2004 item->ri_ops->ra_pass2(log, item);
2005 list_move_tail(&item->ri_list, &ra_list);
2007 if (items_queued >= XLOG_RECOVER_COMMIT_QUEUE_MAX) {
2008 error = xlog_recover_items_pass2(log, trans,
2009 buffer_list, &ra_list);
2010 list_splice_tail_init(&ra_list, &done_list);
2024 if (!list_empty(&ra_list)) {
2026 error = xlog_recover_items_pass2(log, trans,
2027 buffer_list, &ra_list);
2028 list_splice_tail_init(&ra_list, &done_list);
2031 if (!list_empty(&done_list))
2032 list_splice_init(&done_list, &trans->r_itemq);
2038 xlog_recover_add_item(
2039 struct list_head *head)
2041 struct xlog_recover_item *item;
2043 item = kmem_zalloc(sizeof(struct xlog_recover_item), 0);
2044 INIT_LIST_HEAD(&item->ri_list);
2045 list_add_tail(&item->ri_list, head);
2049 xlog_recover_add_to_cont_trans(
2051 struct xlog_recover *trans,
2055 struct xlog_recover_item *item;
2056 char *ptr, *old_ptr;
2060 * If the transaction is empty, the header was split across this and the
2061 * previous record. Copy the rest of the header.
2063 if (list_empty(&trans->r_itemq)) {
2064 ASSERT(len <= sizeof(struct xfs_trans_header));
2065 if (len > sizeof(struct xfs_trans_header)) {
2066 xfs_warn(log->l_mp, "%s: bad header length", __func__);
2067 return -EFSCORRUPTED;
2070 xlog_recover_add_item(&trans->r_itemq);
2071 ptr = (char *)&trans->r_theader +
2072 sizeof(struct xfs_trans_header) - len;
2073 memcpy(ptr, dp, len);
2077 /* take the tail entry */
2078 item = list_entry(trans->r_itemq.prev, struct xlog_recover_item,
2081 old_ptr = item->ri_buf[item->ri_cnt-1].i_addr;
2082 old_len = item->ri_buf[item->ri_cnt-1].i_len;
2084 ptr = kvrealloc(old_ptr, old_len, len + old_len, GFP_KERNEL);
2087 memcpy(&ptr[old_len], dp, len);
2088 item->ri_buf[item->ri_cnt-1].i_len += len;
2089 item->ri_buf[item->ri_cnt-1].i_addr = ptr;
2090 trace_xfs_log_recover_item_add_cont(log, trans, item, 0);
2095 * The next region to add is the start of a new region. It could be
2096 * a whole region or it could be the first part of a new region. Because
2097 * of this, the assumption here is that the type and size fields of all
2098 * format structures fit into the first 32 bits of the structure.
2100 * This works because all regions must be 32 bit aligned. Therefore, we
2101 * either have both fields or we have neither field. In the case we have
2102 * neither field, the data part of the region is zero length. We only have
2103 * a log_op_header and can throw away the header since a new one will appear
2104 * later. If we have at least 4 bytes, then we can determine how many regions
2105 * will appear in the current log item.
2108 xlog_recover_add_to_trans(
2110 struct xlog_recover *trans,
2114 struct xfs_inode_log_format *in_f; /* any will do */
2115 struct xlog_recover_item *item;
2120 if (list_empty(&trans->r_itemq)) {
2121 /* we need to catch log corruptions here */
2122 if (*(uint *)dp != XFS_TRANS_HEADER_MAGIC) {
2123 xfs_warn(log->l_mp, "%s: bad header magic number",
2126 return -EFSCORRUPTED;
2129 if (len > sizeof(struct xfs_trans_header)) {
2130 xfs_warn(log->l_mp, "%s: bad header length", __func__);
2132 return -EFSCORRUPTED;
2136 * The transaction header can be arbitrarily split across op
2137 * records. If we don't have the whole thing here, copy what we
2138 * do have and handle the rest in the next record.
2140 if (len == sizeof(struct xfs_trans_header))
2141 xlog_recover_add_item(&trans->r_itemq);
2142 memcpy(&trans->r_theader, dp, len);
2146 ptr = kmem_alloc(len, 0);
2147 memcpy(ptr, dp, len);
2148 in_f = (struct xfs_inode_log_format *)ptr;
2150 /* take the tail entry */
2151 item = list_entry(trans->r_itemq.prev, struct xlog_recover_item,
2153 if (item->ri_total != 0 &&
2154 item->ri_total == item->ri_cnt) {
2155 /* tail item is in use, get a new one */
2156 xlog_recover_add_item(&trans->r_itemq);
2157 item = list_entry(trans->r_itemq.prev,
2158 struct xlog_recover_item, ri_list);
2161 if (item->ri_total == 0) { /* first region to be added */
2162 if (in_f->ilf_size == 0 ||
2163 in_f->ilf_size > XLOG_MAX_REGIONS_IN_ITEM) {
2165 "bad number of regions (%d) in inode log format",
2169 return -EFSCORRUPTED;
2172 item->ri_total = in_f->ilf_size;
2174 kmem_zalloc(item->ri_total * sizeof(xfs_log_iovec_t),
2178 if (item->ri_total <= item->ri_cnt) {
2180 "log item region count (%d) overflowed size (%d)",
2181 item->ri_cnt, item->ri_total);
2184 return -EFSCORRUPTED;
2187 /* Description region is ri_buf[0] */
2188 item->ri_buf[item->ri_cnt].i_addr = ptr;
2189 item->ri_buf[item->ri_cnt].i_len = len;
2191 trace_xfs_log_recover_item_add(log, trans, item, 0);
2196 * Free up any resources allocated by the transaction
2198 * Remember that EFIs, EFDs, and IUNLINKs are handled later.
2201 xlog_recover_free_trans(
2202 struct xlog_recover *trans)
2204 struct xlog_recover_item *item, *n;
2207 hlist_del_init(&trans->r_list);
2209 list_for_each_entry_safe(item, n, &trans->r_itemq, ri_list) {
2210 /* Free the regions in the item. */
2211 list_del(&item->ri_list);
2212 for (i = 0; i < item->ri_cnt; i++)
2213 kmem_free(item->ri_buf[i].i_addr);
2214 /* Free the item itself */
2215 kmem_free(item->ri_buf);
2218 /* Free the transaction recover structure */
2223 * On error or completion, trans is freed.
2226 xlog_recovery_process_trans(
2228 struct xlog_recover *trans,
2233 struct list_head *buffer_list)
2236 bool freeit = false;
2238 /* mask off ophdr transaction container flags */
2239 flags &= ~XLOG_END_TRANS;
2240 if (flags & XLOG_WAS_CONT_TRANS)
2241 flags &= ~XLOG_CONTINUE_TRANS;
2244 * Callees must not free the trans structure. We'll decide if we need to
2245 * free it or not based on the operation being done and it's result.
2248 /* expected flag values */
2250 case XLOG_CONTINUE_TRANS:
2251 error = xlog_recover_add_to_trans(log, trans, dp, len);
2253 case XLOG_WAS_CONT_TRANS:
2254 error = xlog_recover_add_to_cont_trans(log, trans, dp, len);
2256 case XLOG_COMMIT_TRANS:
2257 error = xlog_recover_commit_trans(log, trans, pass,
2259 /* success or fail, we are now done with this transaction. */
2263 /* unexpected flag values */
2264 case XLOG_UNMOUNT_TRANS:
2265 /* just skip trans */
2266 xfs_warn(log->l_mp, "%s: Unmount LR", __func__);
2269 case XLOG_START_TRANS:
2271 xfs_warn(log->l_mp, "%s: bad flag 0x%x", __func__, flags);
2273 error = -EFSCORRUPTED;
2276 if (error || freeit)
2277 xlog_recover_free_trans(trans);
2282 * Lookup the transaction recovery structure associated with the ID in the
2283 * current ophdr. If the transaction doesn't exist and the start flag is set in
2284 * the ophdr, then allocate a new transaction for future ID matches to find.
2285 * Either way, return what we found during the lookup - an existing transaction
2288 STATIC struct xlog_recover *
2289 xlog_recover_ophdr_to_trans(
2290 struct hlist_head rhash[],
2291 struct xlog_rec_header *rhead,
2292 struct xlog_op_header *ohead)
2294 struct xlog_recover *trans;
2296 struct hlist_head *rhp;
2298 tid = be32_to_cpu(ohead->oh_tid);
2299 rhp = &rhash[XLOG_RHASH(tid)];
2300 hlist_for_each_entry(trans, rhp, r_list) {
2301 if (trans->r_log_tid == tid)
2306 * skip over non-start transaction headers - we could be
2307 * processing slack space before the next transaction starts
2309 if (!(ohead->oh_flags & XLOG_START_TRANS))
2312 ASSERT(be32_to_cpu(ohead->oh_len) == 0);
2315 * This is a new transaction so allocate a new recovery container to
2316 * hold the recovery ops that will follow.
2318 trans = kmem_zalloc(sizeof(struct xlog_recover), 0);
2319 trans->r_log_tid = tid;
2320 trans->r_lsn = be64_to_cpu(rhead->h_lsn);
2321 INIT_LIST_HEAD(&trans->r_itemq);
2322 INIT_HLIST_NODE(&trans->r_list);
2323 hlist_add_head(&trans->r_list, rhp);
2326 * Nothing more to do for this ophdr. Items to be added to this new
2327 * transaction will be in subsequent ophdr containers.
2333 xlog_recover_process_ophdr(
2335 struct hlist_head rhash[],
2336 struct xlog_rec_header *rhead,
2337 struct xlog_op_header *ohead,
2341 struct list_head *buffer_list)
2343 struct xlog_recover *trans;
2347 /* Do we understand who wrote this op? */
2348 if (ohead->oh_clientid != XFS_TRANSACTION &&
2349 ohead->oh_clientid != XFS_LOG) {
2350 xfs_warn(log->l_mp, "%s: bad clientid 0x%x",
2351 __func__, ohead->oh_clientid);
2353 return -EFSCORRUPTED;
2357 * Check the ophdr contains all the data it is supposed to contain.
2359 len = be32_to_cpu(ohead->oh_len);
2360 if (dp + len > end) {
2361 xfs_warn(log->l_mp, "%s: bad length 0x%x", __func__, len);
2363 return -EFSCORRUPTED;
2366 trans = xlog_recover_ophdr_to_trans(rhash, rhead, ohead);
2368 /* nothing to do, so skip over this ophdr */
2373 * The recovered buffer queue is drained only once we know that all
2374 * recovery items for the current LSN have been processed. This is
2377 * - Buffer write submission updates the metadata LSN of the buffer.
2378 * - Log recovery skips items with a metadata LSN >= the current LSN of
2379 * the recovery item.
2380 * - Separate recovery items against the same metadata buffer can share
2381 * a current LSN. I.e., consider that the LSN of a recovery item is
2382 * defined as the starting LSN of the first record in which its
2383 * transaction appears, that a record can hold multiple transactions,
2384 * and/or that a transaction can span multiple records.
2386 * In other words, we are allowed to submit a buffer from log recovery
2387 * once per current LSN. Otherwise, we may incorrectly skip recovery
2388 * items and cause corruption.
2390 * We don't know up front whether buffers are updated multiple times per
2391 * LSN. Therefore, track the current LSN of each commit log record as it
2392 * is processed and drain the queue when it changes. Use commit records
2393 * because they are ordered correctly by the logging code.
2395 if (log->l_recovery_lsn != trans->r_lsn &&
2396 ohead->oh_flags & XLOG_COMMIT_TRANS) {
2397 error = xfs_buf_delwri_submit(buffer_list);
2400 log->l_recovery_lsn = trans->r_lsn;
2403 return xlog_recovery_process_trans(log, trans, dp, len,
2404 ohead->oh_flags, pass, buffer_list);
2408 * There are two valid states of the r_state field. 0 indicates that the
2409 * transaction structure is in a normal state. We have either seen the
2410 * start of the transaction or the last operation we added was not a partial
2411 * operation. If the last operation we added to the transaction was a
2412 * partial operation, we need to mark r_state with XLOG_WAS_CONT_TRANS.
2414 * NOTE: skip LRs with 0 data length.
2417 xlog_recover_process_data(
2419 struct hlist_head rhash[],
2420 struct xlog_rec_header *rhead,
2423 struct list_head *buffer_list)
2425 struct xlog_op_header *ohead;
2430 end = dp + be32_to_cpu(rhead->h_len);
2431 num_logops = be32_to_cpu(rhead->h_num_logops);
2433 /* check the log format matches our own - else we can't recover */
2434 if (xlog_header_check_recover(log->l_mp, rhead))
2437 trace_xfs_log_recover_record(log, rhead, pass);
2438 while ((dp < end) && num_logops) {
2440 ohead = (struct xlog_op_header *)dp;
2441 dp += sizeof(*ohead);
2444 /* errors will abort recovery */
2445 error = xlog_recover_process_ophdr(log, rhash, rhead, ohead,
2446 dp, end, pass, buffer_list);
2450 dp += be32_to_cpu(ohead->oh_len);
2456 /* Take all the collected deferred ops and finish them in order. */
2458 xlog_finish_defer_ops(
2459 struct xfs_mount *mp,
2460 struct list_head *capture_list)
2462 struct xfs_defer_capture *dfc, *next;
2463 struct xfs_trans *tp;
2466 list_for_each_entry_safe(dfc, next, capture_list, dfc_list) {
2467 struct xfs_trans_res resv;
2468 struct xfs_defer_resources dres;
2471 * Create a new transaction reservation from the captured
2472 * information. Set logcount to 1 to force the new transaction
2473 * to regrant every roll so that we can make forward progress
2474 * in recovery no matter how full the log might be.
2476 resv.tr_logres = dfc->dfc_logres;
2477 resv.tr_logcount = 1;
2478 resv.tr_logflags = XFS_TRANS_PERM_LOG_RES;
2480 error = xfs_trans_alloc(mp, &resv, dfc->dfc_blkres,
2481 dfc->dfc_rtxres, XFS_TRANS_RESERVE, &tp);
2483 xlog_force_shutdown(mp->m_log, SHUTDOWN_LOG_IO_ERROR);
2488 * Transfer to this new transaction all the dfops we captured
2489 * from recovering a single intent item.
2491 list_del_init(&dfc->dfc_list);
2492 xfs_defer_ops_continue(dfc, tp, &dres);
2493 error = xfs_trans_commit(tp);
2494 xfs_defer_resources_rele(&dres);
2499 ASSERT(list_empty(capture_list));
2503 /* Release all the captured defer ops and capture structures in this list. */
2505 xlog_abort_defer_ops(
2506 struct xfs_mount *mp,
2507 struct list_head *capture_list)
2509 struct xfs_defer_capture *dfc;
2510 struct xfs_defer_capture *next;
2512 list_for_each_entry_safe(dfc, next, capture_list, dfc_list) {
2513 list_del_init(&dfc->dfc_list);
2514 xfs_defer_ops_capture_free(mp, dfc);
2519 * When this is called, all of the log intent items which did not have
2520 * corresponding log done items should be in the AIL. What we do now is update
2521 * the data structures associated with each one.
2523 * Since we process the log intent items in normal transactions, they will be
2524 * removed at some point after the commit. This prevents us from just walking
2525 * down the list processing each one. We'll use a flag in the intent item to
2526 * skip those that we've already processed and use the AIL iteration mechanism's
2527 * generation count to try to speed this up at least a bit.
2529 * When we start, we know that the intents are the only things in the AIL. As we
2530 * process them, however, other items are added to the AIL. Hence we know we
2531 * have started recovery on all the pending intents when we find an non-intent
2535 xlog_recover_process_intents(
2538 LIST_HEAD(capture_list);
2539 struct xfs_ail_cursor cur;
2540 struct xfs_log_item *lip;
2541 struct xfs_ail *ailp;
2543 #if defined(DEBUG) || defined(XFS_WARN)
2548 spin_lock(&ailp->ail_lock);
2549 #if defined(DEBUG) || defined(XFS_WARN)
2550 last_lsn = xlog_assign_lsn(log->l_curr_cycle, log->l_curr_block);
2552 for (lip = xfs_trans_ail_cursor_first(ailp, &cur, 0);
2554 lip = xfs_trans_ail_cursor_next(ailp, &cur)) {
2555 if (!xlog_item_is_intent(lip))
2559 * We should never see a redo item with a LSN higher than
2560 * the last transaction we found in the log at the start
2563 ASSERT(XFS_LSN_CMP(last_lsn, lip->li_lsn) >= 0);
2566 * NOTE: If your intent processing routine can create more
2567 * deferred ops, you /must/ attach them to the capture list in
2568 * the recover routine or else those subsequent intents will be
2569 * replayed in the wrong order!
2571 spin_unlock(&ailp->ail_lock);
2572 error = lip->li_ops->iop_recover(lip, &capture_list);
2573 spin_lock(&ailp->ail_lock);
2575 trace_xlog_intent_recovery_failed(log->l_mp, error,
2576 lip->li_ops->iop_recover);
2581 xfs_trans_ail_cursor_done(&cur);
2582 spin_unlock(&ailp->ail_lock);
2586 error = xlog_finish_defer_ops(log->l_mp, &capture_list);
2592 xlog_abort_defer_ops(log->l_mp, &capture_list);
2597 * A cancel occurs when the mount has failed and we're bailing out. Release all
2598 * pending log intent items that we haven't started recovery on so they don't
2602 xlog_recover_cancel_intents(
2605 struct xfs_log_item *lip;
2606 struct xfs_ail_cursor cur;
2607 struct xfs_ail *ailp;
2610 spin_lock(&ailp->ail_lock);
2611 lip = xfs_trans_ail_cursor_first(ailp, &cur, 0);
2612 while (lip != NULL) {
2613 if (!xlog_item_is_intent(lip))
2616 spin_unlock(&ailp->ail_lock);
2617 lip->li_ops->iop_release(lip);
2618 spin_lock(&ailp->ail_lock);
2619 lip = xfs_trans_ail_cursor_next(ailp, &cur);
2622 xfs_trans_ail_cursor_done(&cur);
2623 spin_unlock(&ailp->ail_lock);
2627 * This routine performs a transaction to null out a bad inode pointer
2628 * in an agi unlinked inode hash bucket.
2631 xlog_recover_clear_agi_bucket(
2633 xfs_agnumber_t agno,
2638 struct xfs_buf *agibp;
2642 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_clearagi, 0, 0, 0, &tp);
2646 error = xfs_read_agi(mp, tp, agno, &agibp);
2650 agi = agibp->b_addr;
2651 agi->agi_unlinked[bucket] = cpu_to_be32(NULLAGINO);
2652 offset = offsetof(xfs_agi_t, agi_unlinked) +
2653 (sizeof(xfs_agino_t) * bucket);
2654 xfs_trans_log_buf(tp, agibp, offset,
2655 (offset + sizeof(xfs_agino_t) - 1));
2657 error = xfs_trans_commit(tp);
2663 xfs_trans_cancel(tp);
2665 xfs_warn(mp, "%s: failed to clear agi %d. Continuing.", __func__, agno);
2670 xlog_recover_process_one_iunlink(
2671 struct xfs_mount *mp,
2672 xfs_agnumber_t agno,
2676 struct xfs_buf *ibp;
2677 struct xfs_dinode *dip;
2678 struct xfs_inode *ip;
2682 ino = XFS_AGINO_TO_INO(mp, agno, agino);
2683 error = xfs_iget(mp, NULL, ino, 0, 0, &ip);
2688 * Get the on disk inode to find the next inode in the bucket.
2690 error = xfs_imap_to_bp(mp, NULL, &ip->i_imap, &ibp);
2693 dip = xfs_buf_offset(ibp, ip->i_imap.im_boffset);
2695 xfs_iflags_clear(ip, XFS_IRECOVERY);
2696 ASSERT(VFS_I(ip)->i_nlink == 0);
2697 ASSERT(VFS_I(ip)->i_mode != 0);
2699 /* setup for the next pass */
2700 agino = be32_to_cpu(dip->di_next_unlinked);
2710 * We can't read in the inode this bucket points to, or this inode
2711 * is messed up. Just ditch this bucket of inodes. We will lose
2712 * some inodes and space, but at least we won't hang.
2714 * Call xlog_recover_clear_agi_bucket() to perform a transaction to
2715 * clear the inode pointer in the bucket.
2717 xlog_recover_clear_agi_bucket(mp, agno, bucket);
2722 * Recover AGI unlinked lists
2724 * This is called during recovery to process any inodes which we unlinked but
2725 * not freed when the system crashed. These inodes will be on the lists in the
2726 * AGI blocks. What we do here is scan all the AGIs and fully truncate and free
2727 * any inodes found on the lists. Each inode is removed from the lists when it
2728 * has been fully truncated and is freed. The freeing of the inode and its
2729 * removal from the list must be atomic.
2731 * If everything we touch in the agi processing loop is already in memory, this
2732 * loop can hold the cpu for a long time. It runs without lock contention,
2733 * memory allocation contention, the need wait for IO, etc, and so will run
2734 * until we either run out of inodes to process, run low on memory or we run out
2737 * This behaviour is bad for latency on single CPU and non-preemptible kernels,
2738 * and can prevent other filesystem work (such as CIL pushes) from running. This
2739 * can lead to deadlocks if the recovery process runs out of log reservation
2740 * space. Hence we need to yield the CPU when there is other kernel work
2741 * scheduled on this CPU to ensure other scheduled work can run without undue
2745 xlog_recover_process_iunlinks(
2748 struct xfs_mount *mp = log->l_mp;
2749 struct xfs_perag *pag;
2750 xfs_agnumber_t agno;
2751 struct xfs_agi *agi;
2752 struct xfs_buf *agibp;
2757 for_each_perag(mp, agno, pag) {
2758 error = xfs_read_agi(mp, NULL, pag->pag_agno, &agibp);
2761 * AGI is b0rked. Don't process it.
2763 * We should probably mark the filesystem as corrupt
2764 * after we've recovered all the ag's we can....
2769 * Unlock the buffer so that it can be acquired in the normal
2770 * course of the transaction to truncate and free each inode.
2771 * Because we are not racing with anyone else here for the AGI
2772 * buffer, we don't even need to hold it locked to read the
2773 * initial unlinked bucket entries out of the buffer. We keep
2774 * buffer reference though, so that it stays pinned in memory
2775 * while we need the buffer.
2777 agi = agibp->b_addr;
2778 xfs_buf_unlock(agibp);
2780 for (bucket = 0; bucket < XFS_AGI_UNLINKED_BUCKETS; bucket++) {
2781 agino = be32_to_cpu(agi->agi_unlinked[bucket]);
2782 while (agino != NULLAGINO) {
2783 agino = xlog_recover_process_one_iunlink(mp,
2784 pag->pag_agno, agino, bucket);
2788 xfs_buf_rele(agibp);
2792 * Flush the pending unlinked inodes to ensure that the inactivations
2793 * are fully completed on disk and the incore inodes can be reclaimed
2794 * before we signal that recovery is complete.
2796 xfs_inodegc_flush(mp);
2801 struct xlog_rec_header *rhead,
2807 for (i = 0; i < BTOBB(be32_to_cpu(rhead->h_len)) &&
2808 i < (XLOG_HEADER_CYCLE_SIZE / BBSIZE); i++) {
2809 *(__be32 *)dp = *(__be32 *)&rhead->h_cycle_data[i];
2813 if (xfs_has_logv2(log->l_mp)) {
2814 xlog_in_core_2_t *xhdr = (xlog_in_core_2_t *)rhead;
2815 for ( ; i < BTOBB(be32_to_cpu(rhead->h_len)); i++) {
2816 j = i / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
2817 k = i % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
2818 *(__be32 *)dp = xhdr[j].hic_xheader.xh_cycle_data[k];
2825 * CRC check, unpack and process a log record.
2828 xlog_recover_process(
2830 struct hlist_head rhash[],
2831 struct xlog_rec_header *rhead,
2834 struct list_head *buffer_list)
2836 __le32 old_crc = rhead->h_crc;
2839 crc = xlog_cksum(log, rhead, dp, be32_to_cpu(rhead->h_len));
2842 * Nothing else to do if this is a CRC verification pass. Just return
2843 * if this a record with a non-zero crc. Unfortunately, mkfs always
2844 * sets old_crc to 0 so we must consider this valid even on v5 supers.
2845 * Otherwise, return EFSBADCRC on failure so the callers up the stack
2846 * know precisely what failed.
2848 if (pass == XLOG_RECOVER_CRCPASS) {
2849 if (old_crc && crc != old_crc)
2855 * We're in the normal recovery path. Issue a warning if and only if the
2856 * CRC in the header is non-zero. This is an advisory warning and the
2857 * zero CRC check prevents warnings from being emitted when upgrading
2858 * the kernel from one that does not add CRCs by default.
2860 if (crc != old_crc) {
2861 if (old_crc || xfs_has_crc(log->l_mp)) {
2862 xfs_alert(log->l_mp,
2863 "log record CRC mismatch: found 0x%x, expected 0x%x.",
2864 le32_to_cpu(old_crc),
2866 xfs_hex_dump(dp, 32);
2870 * If the filesystem is CRC enabled, this mismatch becomes a
2871 * fatal log corruption failure.
2873 if (xfs_has_crc(log->l_mp)) {
2874 XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, log->l_mp);
2875 return -EFSCORRUPTED;
2879 xlog_unpack_data(rhead, dp, log);
2881 return xlog_recover_process_data(log, rhash, rhead, dp, pass,
2886 xlog_valid_rec_header(
2888 struct xlog_rec_header *rhead,
2894 if (XFS_IS_CORRUPT(log->l_mp,
2895 rhead->h_magicno != cpu_to_be32(XLOG_HEADER_MAGIC_NUM)))
2896 return -EFSCORRUPTED;
2897 if (XFS_IS_CORRUPT(log->l_mp,
2898 (!rhead->h_version ||
2899 (be32_to_cpu(rhead->h_version) &
2900 (~XLOG_VERSION_OKBITS))))) {
2901 xfs_warn(log->l_mp, "%s: unrecognised log version (%d).",
2902 __func__, be32_to_cpu(rhead->h_version));
2903 return -EFSCORRUPTED;
2907 * LR body must have data (or it wouldn't have been written)
2908 * and h_len must not be greater than LR buffer size.
2910 hlen = be32_to_cpu(rhead->h_len);
2911 if (XFS_IS_CORRUPT(log->l_mp, hlen <= 0 || hlen > bufsize))
2912 return -EFSCORRUPTED;
2914 if (XFS_IS_CORRUPT(log->l_mp,
2915 blkno > log->l_logBBsize || blkno > INT_MAX))
2916 return -EFSCORRUPTED;
2921 * Read the log from tail to head and process the log records found.
2922 * Handle the two cases where the tail and head are in the same cycle
2923 * and where the active portion of the log wraps around the end of
2924 * the physical log separately. The pass parameter is passed through
2925 * to the routines called to process the data and is not looked at
2929 xlog_do_recovery_pass(
2931 xfs_daddr_t head_blk,
2932 xfs_daddr_t tail_blk,
2934 xfs_daddr_t *first_bad) /* out: first bad log rec */
2936 xlog_rec_header_t *rhead;
2937 xfs_daddr_t blk_no, rblk_no;
2938 xfs_daddr_t rhead_blk;
2941 int error = 0, h_size, h_len;
2943 int bblks, split_bblks;
2944 int hblks, split_hblks, wrapped_hblks;
2946 struct hlist_head rhash[XLOG_RHASH_SIZE];
2947 LIST_HEAD (buffer_list);
2949 ASSERT(head_blk != tail_blk);
2950 blk_no = rhead_blk = tail_blk;
2952 for (i = 0; i < XLOG_RHASH_SIZE; i++)
2953 INIT_HLIST_HEAD(&rhash[i]);
2956 * Read the header of the tail block and get the iclog buffer size from
2957 * h_size. Use this to tell how many sectors make up the log header.
2959 if (xfs_has_logv2(log->l_mp)) {
2961 * When using variable length iclogs, read first sector of
2962 * iclog header and extract the header size from it. Get a
2963 * new hbp that is the correct size.
2965 hbp = xlog_alloc_buffer(log, 1);
2969 error = xlog_bread(log, tail_blk, 1, hbp, &offset);
2973 rhead = (xlog_rec_header_t *)offset;
2976 * xfsprogs has a bug where record length is based on lsunit but
2977 * h_size (iclog size) is hardcoded to 32k. Now that we
2978 * unconditionally CRC verify the unmount record, this means the
2979 * log buffer can be too small for the record and cause an
2982 * Detect this condition here. Use lsunit for the buffer size as
2983 * long as this looks like the mkfs case. Otherwise, return an
2984 * error to avoid a buffer overrun.
2986 h_size = be32_to_cpu(rhead->h_size);
2987 h_len = be32_to_cpu(rhead->h_len);
2988 if (h_len > h_size && h_len <= log->l_mp->m_logbsize &&
2989 rhead->h_num_logops == cpu_to_be32(1)) {
2991 "invalid iclog size (%d bytes), using lsunit (%d bytes)",
2992 h_size, log->l_mp->m_logbsize);
2993 h_size = log->l_mp->m_logbsize;
2996 error = xlog_valid_rec_header(log, rhead, tail_blk, h_size);
3000 hblks = xlog_logrec_hblks(log, rhead);
3003 hbp = xlog_alloc_buffer(log, hblks);
3006 ASSERT(log->l_sectBBsize == 1);
3008 hbp = xlog_alloc_buffer(log, 1);
3009 h_size = XLOG_BIG_RECORD_BSIZE;
3014 dbp = xlog_alloc_buffer(log, BTOBB(h_size));
3020 memset(rhash, 0, sizeof(rhash));
3021 if (tail_blk > head_blk) {
3023 * Perform recovery around the end of the physical log.
3024 * When the head is not on the same cycle number as the tail,
3025 * we can't do a sequential recovery.
3027 while (blk_no < log->l_logBBsize) {
3029 * Check for header wrapping around physical end-of-log
3034 if (blk_no + hblks <= log->l_logBBsize) {
3035 /* Read header in one read */
3036 error = xlog_bread(log, blk_no, hblks, hbp,
3041 /* This LR is split across physical log end */
3042 if (blk_no != log->l_logBBsize) {
3043 /* some data before physical log end */
3044 ASSERT(blk_no <= INT_MAX);
3045 split_hblks = log->l_logBBsize - (int)blk_no;
3046 ASSERT(split_hblks > 0);
3047 error = xlog_bread(log, blk_no,
3055 * Note: this black magic still works with
3056 * large sector sizes (non-512) only because:
3057 * - we increased the buffer size originally
3058 * by 1 sector giving us enough extra space
3059 * for the second read;
3060 * - the log start is guaranteed to be sector
3062 * - we read the log end (LR header start)
3063 * _first_, then the log start (LR header end)
3064 * - order is important.
3066 wrapped_hblks = hblks - split_hblks;
3067 error = xlog_bread_noalign(log, 0,
3069 offset + BBTOB(split_hblks));
3073 rhead = (xlog_rec_header_t *)offset;
3074 error = xlog_valid_rec_header(log, rhead,
3075 split_hblks ? blk_no : 0, h_size);
3079 bblks = (int)BTOBB(be32_to_cpu(rhead->h_len));
3083 * Read the log record data in multiple reads if it
3084 * wraps around the end of the log. Note that if the
3085 * header already wrapped, blk_no could point past the
3086 * end of the log. The record data is contiguous in
3089 if (blk_no + bblks <= log->l_logBBsize ||
3090 blk_no >= log->l_logBBsize) {
3091 rblk_no = xlog_wrap_logbno(log, blk_no);
3092 error = xlog_bread(log, rblk_no, bblks, dbp,
3097 /* This log record is split across the
3098 * physical end of log */
3101 if (blk_no != log->l_logBBsize) {
3102 /* some data is before the physical
3104 ASSERT(!wrapped_hblks);
3105 ASSERT(blk_no <= INT_MAX);
3107 log->l_logBBsize - (int)blk_no;
3108 ASSERT(split_bblks > 0);
3109 error = xlog_bread(log, blk_no,
3117 * Note: this black magic still works with
3118 * large sector sizes (non-512) only because:
3119 * - we increased the buffer size originally
3120 * by 1 sector giving us enough extra space
3121 * for the second read;
3122 * - the log start is guaranteed to be sector
3124 * - we read the log end (LR header start)
3125 * _first_, then the log start (LR header end)
3126 * - order is important.
3128 error = xlog_bread_noalign(log, 0,
3129 bblks - split_bblks,
3130 offset + BBTOB(split_bblks));
3135 error = xlog_recover_process(log, rhash, rhead, offset,
3136 pass, &buffer_list);
3144 ASSERT(blk_no >= log->l_logBBsize);
3145 blk_no -= log->l_logBBsize;
3149 /* read first part of physical log */
3150 while (blk_no < head_blk) {
3151 error = xlog_bread(log, blk_no, hblks, hbp, &offset);
3155 rhead = (xlog_rec_header_t *)offset;
3156 error = xlog_valid_rec_header(log, rhead, blk_no, h_size);
3160 /* blocks in data section */
3161 bblks = (int)BTOBB(be32_to_cpu(rhead->h_len));
3162 error = xlog_bread(log, blk_no+hblks, bblks, dbp,
3167 error = xlog_recover_process(log, rhash, rhead, offset, pass,
3172 blk_no += bblks + hblks;
3182 * Submit buffers that have been added from the last record processed,
3183 * regardless of error status.
3185 if (!list_empty(&buffer_list))
3186 error2 = xfs_buf_delwri_submit(&buffer_list);
3188 if (error && first_bad)
3189 *first_bad = rhead_blk;
3192 * Transactions are freed at commit time but transactions without commit
3193 * records on disk are never committed. Free any that may be left in the
3196 for (i = 0; i < XLOG_RHASH_SIZE; i++) {
3197 struct hlist_node *tmp;
3198 struct xlog_recover *trans;
3200 hlist_for_each_entry_safe(trans, tmp, &rhash[i], r_list)
3201 xlog_recover_free_trans(trans);
3204 return error ? error : error2;
3208 * Do the recovery of the log. We actually do this in two phases.
3209 * The two passes are necessary in order to implement the function
3210 * of cancelling a record written into the log. The first pass
3211 * determines those things which have been cancelled, and the
3212 * second pass replays log items normally except for those which
3213 * have been cancelled. The handling of the replay and cancellations
3214 * takes place in the log item type specific routines.
3216 * The table of items which have cancel records in the log is allocated
3217 * and freed at this level, since only here do we know when all of
3218 * the log recovery has been completed.
3221 xlog_do_log_recovery(
3223 xfs_daddr_t head_blk,
3224 xfs_daddr_t tail_blk)
3228 ASSERT(head_blk != tail_blk);
3231 * First do a pass to find all of the cancelled buf log items.
3232 * Store them in the buf_cancel_table for use in the second pass.
3234 error = xlog_alloc_buf_cancel_table(log);
3238 error = xlog_do_recovery_pass(log, head_blk, tail_blk,
3239 XLOG_RECOVER_PASS1, NULL);
3244 * Then do a second pass to actually recover the items in the log.
3245 * When it is complete free the table of buf cancel items.
3247 error = xlog_do_recovery_pass(log, head_blk, tail_blk,
3248 XLOG_RECOVER_PASS2, NULL);
3250 xlog_check_buf_cancel_table(log);
3252 xlog_free_buf_cancel_table(log);
3257 * Do the actual recovery
3262 xfs_daddr_t head_blk,
3263 xfs_daddr_t tail_blk)
3265 struct xfs_mount *mp = log->l_mp;
3266 struct xfs_buf *bp = mp->m_sb_bp;
3267 struct xfs_sb *sbp = &mp->m_sb;
3270 trace_xfs_log_recover(log, head_blk, tail_blk);
3273 * First replay the images in the log.
3275 error = xlog_do_log_recovery(log, head_blk, tail_blk);
3279 if (xlog_is_shutdown(log))
3283 * We now update the tail_lsn since much of the recovery has completed
3284 * and there may be space available to use. If there were no extent
3285 * or iunlinks, we can free up the entire log and set the tail_lsn to
3286 * be the last_sync_lsn. This was set in xlog_find_tail to be the
3287 * lsn of the last known good LR on disk. If there are extent frees
3288 * or iunlinks they will have some entries in the AIL; so we look at
3289 * the AIL to determine how to set the tail_lsn.
3291 xlog_assign_tail_lsn(mp);
3294 * Now that we've finished replaying all buffer and inode updates,
3295 * re-read the superblock and reverify it.
3299 error = _xfs_buf_read(bp, XBF_READ);
3301 if (!xlog_is_shutdown(log)) {
3302 xfs_buf_ioerror_alert(bp, __this_address);
3309 /* Convert superblock from on-disk format */
3310 xfs_sb_from_disk(sbp, bp->b_addr);
3313 /* re-initialise in-core superblock and geometry structures */
3314 mp->m_features |= xfs_sb_version_to_features(sbp);
3315 xfs_reinit_percpu_counters(mp);
3316 error = xfs_initialize_perag(mp, sbp->sb_agcount, &mp->m_maxagi);
3318 xfs_warn(mp, "Failed post-recovery per-ag init: %d", error);
3321 mp->m_alloc_set_aside = xfs_alloc_set_aside(mp);
3323 /* Normal transactions can now occur */
3324 clear_bit(XLOG_ACTIVE_RECOVERY, &log->l_opstate);
3329 * Perform recovery and re-initialize some log variables in xlog_find_tail.
3331 * Return error or zero.
3337 xfs_daddr_t head_blk, tail_blk;
3340 /* find the tail of the log */
3341 error = xlog_find_tail(log, &head_blk, &tail_blk);
3346 * The superblock was read before the log was available and thus the LSN
3347 * could not be verified. Check the superblock LSN against the current
3348 * LSN now that it's known.
3350 if (xfs_has_crc(log->l_mp) &&
3351 !xfs_log_check_lsn(log->l_mp, log->l_mp->m_sb.sb_lsn))
3354 if (tail_blk != head_blk) {
3355 /* There used to be a comment here:
3357 * disallow recovery on read-only mounts. note -- mount
3358 * checks for ENOSPC and turns it into an intelligent
3360 * ...but this is no longer true. Now, unless you specify
3361 * NORECOVERY (in which case this function would never be
3362 * called), we just go ahead and recover. We do this all
3363 * under the vfs layer, so we can get away with it unless
3364 * the device itself is read-only, in which case we fail.
3366 if ((error = xfs_dev_is_read_only(log->l_mp, "recovery"))) {
3371 * Version 5 superblock log feature mask validation. We know the
3372 * log is dirty so check if there are any unknown log features
3373 * in what we need to recover. If there are unknown features
3374 * (e.g. unsupported transactions, then simply reject the
3375 * attempt at recovery before touching anything.
3377 if (xfs_sb_is_v5(&log->l_mp->m_sb) &&
3378 xfs_sb_has_incompat_log_feature(&log->l_mp->m_sb,
3379 XFS_SB_FEAT_INCOMPAT_LOG_UNKNOWN)) {
3381 "Superblock has unknown incompatible log features (0x%x) enabled.",
3382 (log->l_mp->m_sb.sb_features_log_incompat &
3383 XFS_SB_FEAT_INCOMPAT_LOG_UNKNOWN));
3385 "The log can not be fully and/or safely recovered by this kernel.");
3387 "Please recover the log on a kernel that supports the unknown features.");
3392 * Delay log recovery if the debug hook is set. This is debug
3393 * instrumentation to coordinate simulation of I/O failures with
3396 if (xfs_globals.log_recovery_delay) {
3397 xfs_notice(log->l_mp,
3398 "Delaying log recovery for %d seconds.",
3399 xfs_globals.log_recovery_delay);
3400 msleep(xfs_globals.log_recovery_delay * 1000);
3403 xfs_notice(log->l_mp, "Starting recovery (logdev: %s)",
3404 log->l_mp->m_logname ? log->l_mp->m_logname
3407 error = xlog_do_recover(log, head_blk, tail_blk);
3408 set_bit(XLOG_RECOVERY_NEEDED, &log->l_opstate);
3414 * In the first part of recovery we replay inodes and buffers and build up the
3415 * list of intents which need to be processed. Here we process the intents and
3416 * clean up the on disk unlinked inode lists. This is separated from the first
3417 * part of recovery so that the root and real-time bitmap inodes can be read in
3418 * from disk in between the two stages. This is necessary so that we can free
3419 * space in the real-time portion of the file system.
3422 xlog_recover_finish(
3427 error = xlog_recover_process_intents(log);
3430 * Cancel all the unprocessed intent items now so that we don't
3431 * leave them pinned in the AIL. This can cause the AIL to
3432 * livelock on the pinned item if anyone tries to push the AIL
3433 * (inode reclaim does this) before we get around to
3434 * xfs_log_mount_cancel.
3436 xlog_recover_cancel_intents(log);
3437 xfs_alert(log->l_mp, "Failed to recover intents");
3438 xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR);
3443 * Sync the log to get all the intents out of the AIL. This isn't
3444 * absolutely necessary, but it helps in case the unlink transactions
3445 * would have problems pushing the intents out of the way.
3447 xfs_log_force(log->l_mp, XFS_LOG_SYNC);
3450 * Now that we've recovered the log and all the intents, we can clear
3451 * the log incompat feature bits in the superblock because there's no
3452 * longer anything to protect. We rely on the AIL push to write out the
3453 * updated superblock after everything else.
3455 if (xfs_clear_incompat_log_features(log->l_mp)) {
3456 error = xfs_sync_sb(log->l_mp, false);
3458 xfs_alert(log->l_mp,
3459 "Failed to clear log incompat features on recovery");
3464 xlog_recover_process_iunlinks(log);
3467 * Recover any CoW staging blocks that are still referenced by the
3468 * ondisk refcount metadata. During mount there cannot be any live
3469 * staging extents as we have not permitted any user modifications.
3470 * Therefore, it is safe to free them all right now, even on a
3473 error = xfs_reflink_recover_cow(log->l_mp);
3475 xfs_alert(log->l_mp,
3476 "Failed to recover leftover CoW staging extents, err %d.",
3479 * If we get an error here, make sure the log is shut down
3480 * but return zero so that any log items committed since the
3481 * end of intents processing can be pushed through the CIL
3484 xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR);
3491 xlog_recover_cancel(
3494 if (xlog_recovery_needed(log))
3495 xlog_recover_cancel_intents(log);
projects / linux-2.6-microblaze.git / blob