1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (c) 2000-2005 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"
12 #include "xfs_mount.h"
13 #include "xfs_errortag.h"
14 #include "xfs_error.h"
15 #include "xfs_trans.h"
16 #include "xfs_trans_priv.h"
18 #include "xfs_log_priv.h"
19 #include "xfs_trace.h"
20 #include "xfs_sysfs.h"
22 #include "xfs_health.h"
24 struct kmem_cache *xfs_log_ticket_cache;
26 /* Local miscellaneous function prototypes */
30 struct xfs_buftarg *log_target,
31 xfs_daddr_t blk_offset,
41 /* local state machine functions */
42 STATIC void xlog_state_done_syncing(
43 struct xlog_in_core *iclog);
44 STATIC void xlog_state_do_callback(
47 xlog_state_get_iclog_space(
50 struct xlog_in_core **iclog,
51 struct xlog_ticket *ticket,
60 struct xlog_in_core *iclog,
61 struct xlog_ticket *ticket);
64 xlog_verify_grant_tail(
69 struct xlog_in_core *iclog,
74 struct xlog_in_core *iclog);
76 #define xlog_verify_grant_tail(a)
77 #define xlog_verify_iclog(a,b,c)
78 #define xlog_verify_tail_lsn(a,b)
86 xfs_log_cover(struct xfs_mount *);
89 * We need to make sure the buffer pointer returned is naturally aligned for the
90 * biggest basic data type we put into it. We have already accounted for this
91 * padding when sizing the buffer.
93 * However, this padding does not get written into the log, and hence we have to
94 * track the space used by the log vectors separately to prevent log space hangs
95 * due to inaccurate accounting (i.e. a leak) of the used log space through the
98 * We also add space for the xlog_op_header that describes this region in the
99 * log. This prepends the data region we return to the caller to copy their data
100 * into, so do all the static initialisation of the ophdr now. Because the ophdr
101 * is not 8 byte aligned, we have to be careful to ensure that we align the
102 * start of the buffer such that the region we return to the call is 8 byte
103 * aligned and packed against the tail of the ophdr.
107 struct xfs_log_vec *lv,
108 struct xfs_log_iovec **vecp,
111 struct xfs_log_iovec *vec = *vecp;
112 struct xlog_op_header *oph;
117 ASSERT(vec - lv->lv_iovecp < lv->lv_niovecs);
120 vec = &lv->lv_iovecp[0];
123 len = lv->lv_buf_len + sizeof(struct xlog_op_header);
124 if (!IS_ALIGNED(len, sizeof(uint64_t))) {
125 lv->lv_buf_len = round_up(len, sizeof(uint64_t)) -
126 sizeof(struct xlog_op_header);
130 vec->i_addr = lv->lv_buf + lv->lv_buf_len;
133 oph->oh_clientid = XFS_TRANSACTION;
137 buf = vec->i_addr + sizeof(struct xlog_op_header);
138 ASSERT(IS_ALIGNED((unsigned long)buf, sizeof(uint64_t)));
145 xlog_grant_sub_space(
150 int64_t head_val = atomic64_read(head);
156 xlog_crack_grant_head_val(head_val, &cycle, &space);
160 space += log->l_logsize;
165 new = xlog_assign_grant_head_val(cycle, space);
166 head_val = atomic64_cmpxchg(head, old, new);
167 } while (head_val != old);
171 xlog_grant_add_space(
176 int64_t head_val = atomic64_read(head);
183 xlog_crack_grant_head_val(head_val, &cycle, &space);
185 tmp = log->l_logsize - space;
194 new = xlog_assign_grant_head_val(cycle, space);
195 head_val = atomic64_cmpxchg(head, old, new);
196 } while (head_val != old);
200 xlog_grant_head_init(
201 struct xlog_grant_head *head)
203 xlog_assign_grant_head(&head->grant, 1, 0);
204 INIT_LIST_HEAD(&head->waiters);
205 spin_lock_init(&head->lock);
209 xlog_grant_head_wake_all(
210 struct xlog_grant_head *head)
212 struct xlog_ticket *tic;
214 spin_lock(&head->lock);
215 list_for_each_entry(tic, &head->waiters, t_queue)
216 wake_up_process(tic->t_task);
217 spin_unlock(&head->lock);
221 xlog_ticket_reservation(
223 struct xlog_grant_head *head,
224 struct xlog_ticket *tic)
226 if (head == &log->l_write_head) {
227 ASSERT(tic->t_flags & XLOG_TIC_PERM_RESERV);
228 return tic->t_unit_res;
231 if (tic->t_flags & XLOG_TIC_PERM_RESERV)
232 return tic->t_unit_res * tic->t_cnt;
234 return tic->t_unit_res;
238 xlog_grant_head_wake(
240 struct xlog_grant_head *head,
243 struct xlog_ticket *tic;
245 bool woken_task = false;
247 list_for_each_entry(tic, &head->waiters, t_queue) {
250 * There is a chance that the size of the CIL checkpoints in
251 * progress at the last AIL push target calculation resulted in
252 * limiting the target to the log head (l_last_sync_lsn) at the
253 * time. This may not reflect where the log head is now as the
254 * CIL checkpoints may have completed.
256 * Hence when we are woken here, it may be that the head of the
257 * log that has moved rather than the tail. As the tail didn't
258 * move, there still won't be space available for the
259 * reservation we require. However, if the AIL has already
260 * pushed to the target defined by the old log head location, we
261 * will hang here waiting for something else to update the AIL
264 * Therefore, if there isn't space to wake the first waiter on
265 * the grant head, we need to push the AIL again to ensure the
266 * target reflects both the current log tail and log head
267 * position before we wait for the tail to move again.
270 need_bytes = xlog_ticket_reservation(log, head, tic);
271 if (*free_bytes < need_bytes) {
273 xlog_grant_push_ail(log, need_bytes);
277 *free_bytes -= need_bytes;
278 trace_xfs_log_grant_wake_up(log, tic);
279 wake_up_process(tic->t_task);
287 xlog_grant_head_wait(
289 struct xlog_grant_head *head,
290 struct xlog_ticket *tic,
291 int need_bytes) __releases(&head->lock)
292 __acquires(&head->lock)
294 list_add_tail(&tic->t_queue, &head->waiters);
297 if (xlog_is_shutdown(log))
299 xlog_grant_push_ail(log, need_bytes);
301 __set_current_state(TASK_UNINTERRUPTIBLE);
302 spin_unlock(&head->lock);
304 XFS_STATS_INC(log->l_mp, xs_sleep_logspace);
306 trace_xfs_log_grant_sleep(log, tic);
308 trace_xfs_log_grant_wake(log, tic);
310 spin_lock(&head->lock);
311 if (xlog_is_shutdown(log))
313 } while (xlog_space_left(log, &head->grant) < need_bytes);
315 list_del_init(&tic->t_queue);
318 list_del_init(&tic->t_queue);
323 * Atomically get the log space required for a log ticket.
325 * Once a ticket gets put onto head->waiters, it will only return after the
326 * needed reservation is satisfied.
328 * This function is structured so that it has a lock free fast path. This is
329 * necessary because every new transaction reservation will come through this
330 * path. Hence any lock will be globally hot if we take it unconditionally on
333 * As tickets are only ever moved on and off head->waiters under head->lock, we
334 * only need to take that lock if we are going to add the ticket to the queue
335 * and sleep. We can avoid taking the lock if the ticket was never added to
336 * head->waiters because the t_queue list head will be empty and we hold the
337 * only reference to it so it can safely be checked unlocked.
340 xlog_grant_head_check(
342 struct xlog_grant_head *head,
343 struct xlog_ticket *tic,
349 ASSERT(!xlog_in_recovery(log));
352 * If there are other waiters on the queue then give them a chance at
353 * logspace before us. Wake up the first waiters, if we do not wake
354 * up all the waiters then go to sleep waiting for more free space,
355 * otherwise try to get some space for this transaction.
357 *need_bytes = xlog_ticket_reservation(log, head, tic);
358 free_bytes = xlog_space_left(log, &head->grant);
359 if (!list_empty_careful(&head->waiters)) {
360 spin_lock(&head->lock);
361 if (!xlog_grant_head_wake(log, head, &free_bytes) ||
362 free_bytes < *need_bytes) {
363 error = xlog_grant_head_wait(log, head, tic,
366 spin_unlock(&head->lock);
367 } else if (free_bytes < *need_bytes) {
368 spin_lock(&head->lock);
369 error = xlog_grant_head_wait(log, head, tic, *need_bytes);
370 spin_unlock(&head->lock);
378 struct xfs_mount *mp)
381 * Do not write to the log on norecovery mounts, if the data or log
382 * devices are read-only, or if the filesystem is shutdown. Read-only
383 * mounts allow internal writes for log recovery and unmount purposes,
384 * so don't restrict that case.
386 if (xfs_has_norecovery(mp))
388 if (xfs_readonly_buftarg(mp->m_ddev_targp))
390 if (xfs_readonly_buftarg(mp->m_log->l_targ))
392 if (xlog_is_shutdown(mp->m_log))
398 * Replenish the byte reservation required by moving the grant write head.
402 struct xfs_mount *mp,
403 struct xlog_ticket *tic)
405 struct xlog *log = mp->m_log;
409 if (xlog_is_shutdown(log))
412 XFS_STATS_INC(mp, xs_try_logspace);
415 * This is a new transaction on the ticket, so we need to change the
416 * transaction ID so that the next transaction has a different TID in
417 * the log. Just add one to the existing tid so that we can see chains
418 * of rolling transactions in the log easily.
422 xlog_grant_push_ail(log, tic->t_unit_res);
424 tic->t_curr_res = tic->t_unit_res;
428 trace_xfs_log_regrant(log, tic);
430 error = xlog_grant_head_check(log, &log->l_write_head, tic,
435 xlog_grant_add_space(log, &log->l_write_head.grant, need_bytes);
436 trace_xfs_log_regrant_exit(log, tic);
437 xlog_verify_grant_tail(log);
442 * If we are failing, make sure the ticket doesn't have any current
443 * reservations. We don't want to add this back when the ticket/
444 * transaction gets cancelled.
447 tic->t_cnt = 0; /* ungrant will give back unit_res * t_cnt. */
452 * Reserve log space and return a ticket corresponding to the reservation.
454 * Each reservation is going to reserve extra space for a log record header.
455 * When writes happen to the on-disk log, we don't subtract the length of the
456 * log record header from any reservation. By wasting space in each
457 * reservation, we prevent over allocation problems.
461 struct xfs_mount *mp,
464 struct xlog_ticket **ticp,
467 struct xlog *log = mp->m_log;
468 struct xlog_ticket *tic;
472 if (xlog_is_shutdown(log))
475 XFS_STATS_INC(mp, xs_try_logspace);
477 ASSERT(*ticp == NULL);
478 tic = xlog_ticket_alloc(log, unit_bytes, cnt, permanent);
481 xlog_grant_push_ail(log, tic->t_cnt ? tic->t_unit_res * tic->t_cnt
484 trace_xfs_log_reserve(log, tic);
486 error = xlog_grant_head_check(log, &log->l_reserve_head, tic,
491 xlog_grant_add_space(log, &log->l_reserve_head.grant, need_bytes);
492 xlog_grant_add_space(log, &log->l_write_head.grant, need_bytes);
493 trace_xfs_log_reserve_exit(log, tic);
494 xlog_verify_grant_tail(log);
499 * If we are failing, make sure the ticket doesn't have any current
500 * reservations. We don't want to add this back when the ticket/
501 * transaction gets cancelled.
504 tic->t_cnt = 0; /* ungrant will give back unit_res * t_cnt. */
509 * Run all the pending iclog callbacks and wake log force waiters and iclog
510 * space waiters so they can process the newly set shutdown state. We really
511 * don't care what order we process callbacks here because the log is shut down
512 * and so state cannot change on disk anymore. However, we cannot wake waiters
513 * until the callbacks have been processed because we may be in unmount and
514 * we must ensure that all AIL operations the callbacks perform have completed
515 * before we tear down the AIL.
517 * We avoid processing actively referenced iclogs so that we don't run callbacks
518 * while the iclog owner might still be preparing the iclog for IO submssion.
519 * These will be caught by xlog_state_iclog_release() and call this function
520 * again to process any callbacks that may have been added to that iclog.
523 xlog_state_shutdown_callbacks(
526 struct xlog_in_core *iclog;
529 iclog = log->l_iclog;
531 if (atomic_read(&iclog->ic_refcnt)) {
532 /* Reference holder will re-run iclog callbacks. */
535 list_splice_init(&iclog->ic_callbacks, &cb_list);
536 spin_unlock(&log->l_icloglock);
538 xlog_cil_process_committed(&cb_list);
540 spin_lock(&log->l_icloglock);
541 wake_up_all(&iclog->ic_write_wait);
542 wake_up_all(&iclog->ic_force_wait);
543 } while ((iclog = iclog->ic_next) != log->l_iclog);
545 wake_up_all(&log->l_flush_wait);
549 * Flush iclog to disk if this is the last reference to the given iclog and the
550 * it is in the WANT_SYNC state.
552 * If XLOG_ICL_NEED_FUA is already set on the iclog, we need to ensure that the
553 * log tail is updated correctly. NEED_FUA indicates that the iclog will be
554 * written to stable storage, and implies that a commit record is contained
555 * within the iclog. We need to ensure that the log tail does not move beyond
556 * the tail that the first commit record in the iclog ordered against, otherwise
557 * correct recovery of that checkpoint becomes dependent on future operations
558 * performed on this iclog.
560 * Hence if NEED_FUA is set and the current iclog tail lsn is empty, write the
561 * current tail into iclog. Once the iclog tail is set, future operations must
562 * not modify it, otherwise they potentially violate ordering constraints for
563 * the checkpoint commit that wrote the initial tail lsn value. The tail lsn in
564 * the iclog will get zeroed on activation of the iclog after sync, so we
565 * always capture the tail lsn on the iclog on the first NEED_FUA release
566 * regardless of the number of active reference counts on this iclog.
569 xlog_state_release_iclog(
571 struct xlog_in_core *iclog,
572 struct xlog_ticket *ticket)
577 lockdep_assert_held(&log->l_icloglock);
579 trace_xlog_iclog_release(iclog, _RET_IP_);
581 * Grabbing the current log tail needs to be atomic w.r.t. the writing
582 * of the tail LSN into the iclog so we guarantee that the log tail does
583 * not move between the first time we know that the iclog needs to be
584 * made stable and when we eventually submit it.
586 if ((iclog->ic_state == XLOG_STATE_WANT_SYNC ||
587 (iclog->ic_flags & XLOG_ICL_NEED_FUA)) &&
588 !iclog->ic_header.h_tail_lsn) {
589 tail_lsn = xlog_assign_tail_lsn(log->l_mp);
590 iclog->ic_header.h_tail_lsn = cpu_to_be64(tail_lsn);
593 last_ref = atomic_dec_and_test(&iclog->ic_refcnt);
595 if (xlog_is_shutdown(log)) {
597 * If there are no more references to this iclog, process the
598 * pending iclog callbacks that were waiting on the release of
602 xlog_state_shutdown_callbacks(log);
609 if (iclog->ic_state != XLOG_STATE_WANT_SYNC) {
610 ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE);
614 iclog->ic_state = XLOG_STATE_SYNCING;
615 xlog_verify_tail_lsn(log, iclog);
616 trace_xlog_iclog_syncing(iclog, _RET_IP_);
618 spin_unlock(&log->l_icloglock);
619 xlog_sync(log, iclog, ticket);
620 spin_lock(&log->l_icloglock);
625 * Mount a log filesystem
627 * mp - ubiquitous xfs mount point structure
628 * log_target - buftarg of on-disk log device
629 * blk_offset - Start block # where block size is 512 bytes (BBSIZE)
630 * num_bblocks - Number of BBSIZE blocks in on-disk log
632 * Return error or zero.
637 xfs_buftarg_t *log_target,
638 xfs_daddr_t blk_offset,
642 bool fatal = xfs_has_crc(mp);
646 if (!xfs_has_norecovery(mp)) {
647 xfs_notice(mp, "Mounting V%d Filesystem",
648 XFS_SB_VERSION_NUM(&mp->m_sb));
651 "Mounting V%d filesystem in no-recovery mode. Filesystem will be inconsistent.",
652 XFS_SB_VERSION_NUM(&mp->m_sb));
653 ASSERT(xfs_is_readonly(mp));
656 log = xlog_alloc_log(mp, log_target, blk_offset, num_bblks);
658 error = PTR_ERR(log);
664 * Validate the given log space and drop a critical message via syslog
665 * if the log size is too small that would lead to some unexpected
666 * situations in transaction log space reservation stage.
668 * Note: we can't just reject the mount if the validation fails. This
669 * would mean that people would have to downgrade their kernel just to
670 * remedy the situation as there is no way to grow the log (short of
671 * black magic surgery with xfs_db).
673 * We can, however, reject mounts for CRC format filesystems, as the
674 * mkfs binary being used to make the filesystem should never create a
675 * filesystem with a log that is too small.
677 min_logfsbs = xfs_log_calc_minimum_size(mp);
679 if (mp->m_sb.sb_logblocks < min_logfsbs) {
681 "Log size %d blocks too small, minimum size is %d blocks",
682 mp->m_sb.sb_logblocks, min_logfsbs);
684 } else if (mp->m_sb.sb_logblocks > XFS_MAX_LOG_BLOCKS) {
686 "Log size %d blocks too large, maximum size is %lld blocks",
687 mp->m_sb.sb_logblocks, XFS_MAX_LOG_BLOCKS);
689 } else if (XFS_FSB_TO_B(mp, mp->m_sb.sb_logblocks) > XFS_MAX_LOG_BYTES) {
691 "log size %lld bytes too large, maximum size is %lld bytes",
692 XFS_FSB_TO_B(mp, mp->m_sb.sb_logblocks),
695 } else if (mp->m_sb.sb_logsunit > 1 &&
696 mp->m_sb.sb_logsunit % mp->m_sb.sb_blocksize) {
698 "log stripe unit %u bytes must be a multiple of block size",
699 mp->m_sb.sb_logsunit);
705 * Log check errors are always fatal on v5; or whenever bad
706 * metadata leads to a crash.
709 xfs_crit(mp, "AAIEEE! Log failed size checks. Abort!");
713 xfs_crit(mp, "Log size out of supported range.");
715 "Continuing onwards, but if log hangs are experienced then please report this message in the bug report.");
719 * Initialize the AIL now we have a log.
721 error = xfs_trans_ail_init(mp);
723 xfs_warn(mp, "AIL initialisation failed: error %d", error);
726 log->l_ailp = mp->m_ail;
729 * skip log recovery on a norecovery mount. pretend it all
732 if (!xfs_has_norecovery(mp)) {
734 * log recovery ignores readonly state and so we need to clear
735 * mount-based read only state so it can write to disk.
737 bool readonly = test_and_clear_bit(XFS_OPSTATE_READONLY,
739 error = xlog_recover(log);
741 set_bit(XFS_OPSTATE_READONLY, &mp->m_opstate);
743 xfs_warn(mp, "log mount/recovery failed: error %d",
745 xlog_recover_cancel(log);
746 goto out_destroy_ail;
750 error = xfs_sysfs_init(&log->l_kobj, &xfs_log_ktype, &mp->m_kobj,
753 goto out_destroy_ail;
755 /* Normal transactions can now occur */
756 clear_bit(XLOG_ACTIVE_RECOVERY, &log->l_opstate);
759 * Now the log has been fully initialised and we know were our
760 * space grant counters are, we can initialise the permanent ticket
761 * needed for delayed logging to work.
763 xlog_cil_init_post_recovery(log);
768 xfs_trans_ail_destroy(mp);
770 xlog_dealloc_log(log);
776 * Finish the recovery of the file system. This is separate from the
777 * xfs_log_mount() call, because it depends on the code in xfs_mountfs() to read
778 * in the root and real-time bitmap inodes between calling xfs_log_mount() and
781 * If we finish recovery successfully, start the background log work. If we are
782 * not doing recovery, then we have a RO filesystem and we don't need to start
786 xfs_log_mount_finish(
787 struct xfs_mount *mp)
789 struct xlog *log = mp->m_log;
793 if (xfs_has_norecovery(mp)) {
794 ASSERT(xfs_is_readonly(mp));
799 * log recovery ignores readonly state and so we need to clear
800 * mount-based read only state so it can write to disk.
802 readonly = test_and_clear_bit(XFS_OPSTATE_READONLY, &mp->m_opstate);
805 * During the second phase of log recovery, we need iget and
806 * iput to behave like they do for an active filesystem.
807 * xfs_fs_drop_inode needs to be able to prevent the deletion
808 * of inodes before we're done replaying log items on those
809 * inodes. Turn it off immediately after recovery finishes
810 * so that we don't leak the quota inodes if subsequent mount
813 * We let all inodes involved in redo item processing end up on
814 * the LRU instead of being evicted immediately so that if we do
815 * something to an unlinked inode, the irele won't cause
816 * premature truncation and freeing of the inode, which results
817 * in log recovery failure. We have to evict the unreferenced
818 * lru inodes after clearing SB_ACTIVE because we don't
819 * otherwise clean up the lru if there's a subsequent failure in
820 * xfs_mountfs, which leads to us leaking the inodes if nothing
821 * else (e.g. quotacheck) references the inodes before the
822 * mount failure occurs.
824 mp->m_super->s_flags |= SB_ACTIVE;
825 xfs_log_work_queue(mp);
826 if (xlog_recovery_needed(log))
827 error = xlog_recover_finish(log);
828 mp->m_super->s_flags &= ~SB_ACTIVE;
829 evict_inodes(mp->m_super);
832 * Drain the buffer LRU after log recovery. This is required for v4
833 * filesystems to avoid leaving around buffers with NULL verifier ops,
834 * but we do it unconditionally to make sure we're always in a clean
835 * cache state after mount.
837 * Don't push in the error case because the AIL may have pending intents
838 * that aren't removed until recovery is cancelled.
840 if (xlog_recovery_needed(log)) {
842 xfs_log_force(mp, XFS_LOG_SYNC);
843 xfs_ail_push_all_sync(mp->m_ail);
845 xfs_notice(mp, "Ending recovery (logdev: %s)",
846 mp->m_logname ? mp->m_logname : "internal");
848 xfs_info(mp, "Ending clean mount");
850 xfs_buftarg_drain(mp->m_ddev_targp);
852 clear_bit(XLOG_RECOVERY_NEEDED, &log->l_opstate);
854 set_bit(XFS_OPSTATE_READONLY, &mp->m_opstate);
856 /* Make sure the log is dead if we're returning failure. */
857 ASSERT(!error || xlog_is_shutdown(log));
863 * The mount has failed. Cancel the recovery if it hasn't completed and destroy
867 xfs_log_mount_cancel(
868 struct xfs_mount *mp)
870 xlog_recover_cancel(mp->m_log);
875 * Flush out the iclog to disk ensuring that device caches are flushed and
876 * the iclog hits stable storage before any completion waiters are woken.
880 struct xlog_in_core *iclog)
882 atomic_inc(&iclog->ic_refcnt);
883 iclog->ic_flags |= XLOG_ICL_NEED_FLUSH | XLOG_ICL_NEED_FUA;
884 if (iclog->ic_state == XLOG_STATE_ACTIVE)
885 xlog_state_switch_iclogs(iclog->ic_log, iclog, 0);
886 return xlog_state_release_iclog(iclog->ic_log, iclog, NULL);
890 * Wait for the iclog and all prior iclogs to be written disk as required by the
891 * log force state machine. Waiting on ic_force_wait ensures iclog completions
892 * have been ordered and callbacks run before we are woken here, hence
893 * guaranteeing that all the iclogs up to this one are on stable storage.
897 struct xlog_in_core *iclog)
898 __releases(iclog->ic_log->l_icloglock)
900 struct xlog *log = iclog->ic_log;
902 trace_xlog_iclog_wait_on(iclog, _RET_IP_);
903 if (!xlog_is_shutdown(log) &&
904 iclog->ic_state != XLOG_STATE_ACTIVE &&
905 iclog->ic_state != XLOG_STATE_DIRTY) {
906 XFS_STATS_INC(log->l_mp, xs_log_force_sleep);
907 xlog_wait(&iclog->ic_force_wait, &log->l_icloglock);
909 spin_unlock(&log->l_icloglock);
912 if (xlog_is_shutdown(log))
918 * Write out an unmount record using the ticket provided. We have to account for
919 * the data space used in the unmount ticket as this write is not done from a
920 * transaction context that has already done the accounting for us.
923 xlog_write_unmount_record(
925 struct xlog_ticket *ticket)
928 struct xlog_op_header ophdr;
929 struct xfs_unmount_log_format ulf;
932 .oh_clientid = XFS_LOG,
933 .oh_tid = cpu_to_be32(ticket->t_tid),
934 .oh_flags = XLOG_UNMOUNT_TRANS,
937 .magic = XLOG_UNMOUNT_TYPE,
940 struct xfs_log_iovec reg = {
941 .i_addr = &unmount_rec,
942 .i_len = sizeof(unmount_rec),
943 .i_type = XLOG_REG_TYPE_UNMOUNT,
945 struct xfs_log_vec vec = {
950 list_add(&vec.lv_list, &lv_chain);
952 BUILD_BUG_ON((sizeof(struct xlog_op_header) +
953 sizeof(struct xfs_unmount_log_format)) !=
954 sizeof(unmount_rec));
956 /* account for space used by record data */
957 ticket->t_curr_res -= sizeof(unmount_rec);
959 return xlog_write(log, NULL, &lv_chain, ticket, reg.i_len);
963 * Mark the filesystem clean by writing an unmount record to the head of the
970 struct xfs_mount *mp = log->l_mp;
971 struct xlog_in_core *iclog;
972 struct xlog_ticket *tic = NULL;
975 error = xfs_log_reserve(mp, 600, 1, &tic, 0);
979 error = xlog_write_unmount_record(log, tic);
981 * At this point, we're umounting anyway, so there's no point in
982 * transitioning log state to shutdown. Just continue...
986 xfs_alert(mp, "%s: unmount record failed", __func__);
988 spin_lock(&log->l_icloglock);
989 iclog = log->l_iclog;
990 error = xlog_force_iclog(iclog);
991 xlog_wait_on_iclog(iclog);
994 trace_xfs_log_umount_write(log, tic);
995 xfs_log_ticket_ungrant(log, tic);
1000 xfs_log_unmount_verify_iclog(
1003 struct xlog_in_core *iclog = log->l_iclog;
1006 ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE);
1007 ASSERT(iclog->ic_offset == 0);
1008 } while ((iclog = iclog->ic_next) != log->l_iclog);
1012 * Unmount record used to have a string "Unmount filesystem--" in the
1013 * data section where the "Un" was really a magic number (XLOG_UNMOUNT_TYPE).
1014 * We just write the magic number now since that particular field isn't
1015 * currently architecture converted and "Unmount" is a bit foo.
1016 * As far as I know, there weren't any dependencies on the old behaviour.
1019 xfs_log_unmount_write(
1020 struct xfs_mount *mp)
1022 struct xlog *log = mp->m_log;
1024 if (!xfs_log_writable(mp))
1027 xfs_log_force(mp, XFS_LOG_SYNC);
1029 if (xlog_is_shutdown(log))
1033 * If we think the summary counters are bad, avoid writing the unmount
1034 * record to force log recovery at next mount, after which the summary
1035 * counters will be recalculated. Refer to xlog_check_unmount_rec for
1038 if (XFS_TEST_ERROR(xfs_fs_has_sickness(mp, XFS_SICK_FS_COUNTERS), mp,
1039 XFS_ERRTAG_FORCE_SUMMARY_RECALC)) {
1040 xfs_alert(mp, "%s: will fix summary counters at next mount",
1045 xfs_log_unmount_verify_iclog(log);
1046 xlog_unmount_write(log);
1050 * Empty the log for unmount/freeze.
1052 * To do this, we first need to shut down the background log work so it is not
1053 * trying to cover the log as we clean up. We then need to unpin all objects in
1054 * the log so we can then flush them out. Once they have completed their IO and
1055 * run the callbacks removing themselves from the AIL, we can cover the log.
1059 struct xfs_mount *mp)
1062 * Clear log incompat features since we're quiescing the log. Report
1063 * failures, though it's not fatal to have a higher log feature
1064 * protection level than the log contents actually require.
1066 if (xfs_clear_incompat_log_features(mp)) {
1069 error = xfs_sync_sb(mp, false);
1072 "Failed to clear log incompat features on quiesce");
1075 cancel_delayed_work_sync(&mp->m_log->l_work);
1076 xfs_log_force(mp, XFS_LOG_SYNC);
1079 * The superblock buffer is uncached and while xfs_ail_push_all_sync()
1080 * will push it, xfs_buftarg_wait() will not wait for it. Further,
1081 * xfs_buf_iowait() cannot be used because it was pushed with the
1082 * XBF_ASYNC flag set, so we need to use a lock/unlock pair to wait for
1083 * the IO to complete.
1085 xfs_ail_push_all_sync(mp->m_ail);
1086 xfs_buftarg_wait(mp->m_ddev_targp);
1087 xfs_buf_lock(mp->m_sb_bp);
1088 xfs_buf_unlock(mp->m_sb_bp);
1090 return xfs_log_cover(mp);
1095 struct xfs_mount *mp)
1097 xfs_log_quiesce(mp);
1098 xfs_log_unmount_write(mp);
1102 * Shut down and release the AIL and Log.
1104 * During unmount, we need to ensure we flush all the dirty metadata objects
1105 * from the AIL so that the log is empty before we write the unmount record to
1106 * the log. Once this is done, we can tear down the AIL and the log.
1110 struct xfs_mount *mp)
1114 xfs_buftarg_drain(mp->m_ddev_targp);
1116 xfs_trans_ail_destroy(mp);
1118 xfs_sysfs_del(&mp->m_log->l_kobj);
1120 xlog_dealloc_log(mp->m_log);
1125 struct xfs_mount *mp,
1126 struct xfs_log_item *item,
1128 const struct xfs_item_ops *ops)
1130 item->li_log = mp->m_log;
1131 item->li_ailp = mp->m_ail;
1132 item->li_type = type;
1136 INIT_LIST_HEAD(&item->li_ail);
1137 INIT_LIST_HEAD(&item->li_cil);
1138 INIT_LIST_HEAD(&item->li_bio_list);
1139 INIT_LIST_HEAD(&item->li_trans);
1143 * Wake up processes waiting for log space after we have moved the log tail.
1147 struct xfs_mount *mp)
1149 struct xlog *log = mp->m_log;
1152 if (xlog_is_shutdown(log))
1155 if (!list_empty_careful(&log->l_write_head.waiters)) {
1156 ASSERT(!xlog_in_recovery(log));
1158 spin_lock(&log->l_write_head.lock);
1159 free_bytes = xlog_space_left(log, &log->l_write_head.grant);
1160 xlog_grant_head_wake(log, &log->l_write_head, &free_bytes);
1161 spin_unlock(&log->l_write_head.lock);
1164 if (!list_empty_careful(&log->l_reserve_head.waiters)) {
1165 ASSERT(!xlog_in_recovery(log));
1167 spin_lock(&log->l_reserve_head.lock);
1168 free_bytes = xlog_space_left(log, &log->l_reserve_head.grant);
1169 xlog_grant_head_wake(log, &log->l_reserve_head, &free_bytes);
1170 spin_unlock(&log->l_reserve_head.lock);
1175 * Determine if we have a transaction that has gone to disk that needs to be
1176 * covered. To begin the transition to the idle state firstly the log needs to
1177 * be idle. That means the CIL, the AIL and the iclogs needs to be empty before
1178 * we start attempting to cover the log.
1180 * Only if we are then in a state where covering is needed, the caller is
1181 * informed that dummy transactions are required to move the log into the idle
1184 * If there are any items in the AIl or CIL, then we do not want to attempt to
1185 * cover the log as we may be in a situation where there isn't log space
1186 * available to run a dummy transaction and this can lead to deadlocks when the
1187 * tail of the log is pinned by an item that is modified in the CIL. Hence
1188 * there's no point in running a dummy transaction at this point because we
1189 * can't start trying to idle the log until both the CIL and AIL are empty.
1192 xfs_log_need_covered(
1193 struct xfs_mount *mp)
1195 struct xlog *log = mp->m_log;
1196 bool needed = false;
1198 if (!xlog_cil_empty(log))
1201 spin_lock(&log->l_icloglock);
1202 switch (log->l_covered_state) {
1203 case XLOG_STATE_COVER_DONE:
1204 case XLOG_STATE_COVER_DONE2:
1205 case XLOG_STATE_COVER_IDLE:
1207 case XLOG_STATE_COVER_NEED:
1208 case XLOG_STATE_COVER_NEED2:
1209 if (xfs_ail_min_lsn(log->l_ailp))
1211 if (!xlog_iclogs_empty(log))
1215 if (log->l_covered_state == XLOG_STATE_COVER_NEED)
1216 log->l_covered_state = XLOG_STATE_COVER_DONE;
1218 log->l_covered_state = XLOG_STATE_COVER_DONE2;
1224 spin_unlock(&log->l_icloglock);
1229 * Explicitly cover the log. This is similar to background log covering but
1230 * intended for usage in quiesce codepaths. The caller is responsible to ensure
1231 * the log is idle and suitable for covering. The CIL, iclog buffers and AIL
1232 * must all be empty.
1236 struct xfs_mount *mp)
1241 ASSERT((xlog_cil_empty(mp->m_log) && xlog_iclogs_empty(mp->m_log) &&
1242 !xfs_ail_min_lsn(mp->m_log->l_ailp)) ||
1243 xlog_is_shutdown(mp->m_log));
1245 if (!xfs_log_writable(mp))
1249 * xfs_log_need_covered() is not idempotent because it progresses the
1250 * state machine if the log requires covering. Therefore, we must call
1251 * this function once and use the result until we've issued an sb sync.
1252 * Do so first to make that abundantly clear.
1254 * Fall into the covering sequence if the log needs covering or the
1255 * mount has lazy superblock accounting to sync to disk. The sb sync
1256 * used for covering accumulates the in-core counters, so covering
1257 * handles this for us.
1259 need_covered = xfs_log_need_covered(mp);
1260 if (!need_covered && !xfs_has_lazysbcount(mp))
1264 * To cover the log, commit the superblock twice (at most) in
1265 * independent checkpoints. The first serves as a reference for the
1266 * tail pointer. The sync transaction and AIL push empties the AIL and
1267 * updates the in-core tail to the LSN of the first checkpoint. The
1268 * second commit updates the on-disk tail with the in-core LSN,
1269 * covering the log. Push the AIL one more time to leave it empty, as
1273 error = xfs_sync_sb(mp, true);
1276 xfs_ail_push_all_sync(mp->m_ail);
1277 } while (xfs_log_need_covered(mp));
1283 * We may be holding the log iclog lock upon entering this routine.
1286 xlog_assign_tail_lsn_locked(
1287 struct xfs_mount *mp)
1289 struct xlog *log = mp->m_log;
1290 struct xfs_log_item *lip;
1293 assert_spin_locked(&mp->m_ail->ail_lock);
1296 * To make sure we always have a valid LSN for the log tail we keep
1297 * track of the last LSN which was committed in log->l_last_sync_lsn,
1298 * and use that when the AIL was empty.
1300 lip = xfs_ail_min(mp->m_ail);
1302 tail_lsn = lip->li_lsn;
1304 tail_lsn = atomic64_read(&log->l_last_sync_lsn);
1305 trace_xfs_log_assign_tail_lsn(log, tail_lsn);
1306 atomic64_set(&log->l_tail_lsn, tail_lsn);
1311 xlog_assign_tail_lsn(
1312 struct xfs_mount *mp)
1316 spin_lock(&mp->m_ail->ail_lock);
1317 tail_lsn = xlog_assign_tail_lsn_locked(mp);
1318 spin_unlock(&mp->m_ail->ail_lock);
1324 * Return the space in the log between the tail and the head. The head
1325 * is passed in the cycle/bytes formal parms. In the special case where
1326 * the reserve head has wrapped passed the tail, this calculation is no
1327 * longer valid. In this case, just return 0 which means there is no space
1328 * in the log. This works for all places where this function is called
1329 * with the reserve head. Of course, if the write head were to ever
1330 * wrap the tail, we should blow up. Rather than catch this case here,
1331 * we depend on other ASSERTions in other parts of the code. XXXmiken
1333 * If reservation head is behind the tail, we have a problem. Warn about it,
1334 * but then treat it as if the log is empty.
1336 * If the log is shut down, the head and tail may be invalid or out of whack, so
1337 * shortcut invalidity asserts in this case so that we don't trigger them
1350 xlog_crack_grant_head(head, &head_cycle, &head_bytes);
1351 xlog_crack_atomic_lsn(&log->l_tail_lsn, &tail_cycle, &tail_bytes);
1352 tail_bytes = BBTOB(tail_bytes);
1353 if (tail_cycle == head_cycle && head_bytes >= tail_bytes)
1354 return log->l_logsize - (head_bytes - tail_bytes);
1355 if (tail_cycle + 1 < head_cycle)
1358 /* Ignore potential inconsistency when shutdown. */
1359 if (xlog_is_shutdown(log))
1360 return log->l_logsize;
1362 if (tail_cycle < head_cycle) {
1363 ASSERT(tail_cycle == (head_cycle - 1));
1364 return tail_bytes - head_bytes;
1368 * The reservation head is behind the tail. In this case we just want to
1369 * return the size of the log as the amount of space left.
1371 xfs_alert(log->l_mp, "xlog_space_left: head behind tail");
1372 xfs_alert(log->l_mp, " tail_cycle = %d, tail_bytes = %d",
1373 tail_cycle, tail_bytes);
1374 xfs_alert(log->l_mp, " GH cycle = %d, GH bytes = %d",
1375 head_cycle, head_bytes);
1377 return log->l_logsize;
1383 struct work_struct *work)
1385 struct xlog_in_core *iclog =
1386 container_of(work, struct xlog_in_core, ic_end_io_work);
1387 struct xlog *log = iclog->ic_log;
1390 error = blk_status_to_errno(iclog->ic_bio.bi_status);
1392 /* treat writes with injected CRC errors as failed */
1393 if (iclog->ic_fail_crc)
1398 * Race to shutdown the filesystem if we see an error.
1400 if (XFS_TEST_ERROR(error, log->l_mp, XFS_ERRTAG_IODONE_IOERR)) {
1401 xfs_alert(log->l_mp, "log I/O error %d", error);
1402 xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR);
1405 xlog_state_done_syncing(iclog);
1406 bio_uninit(&iclog->ic_bio);
1409 * Drop the lock to signal that we are done. Nothing references the
1410 * iclog after this, so an unmount waiting on this lock can now tear it
1411 * down safely. As such, it is unsafe to reference the iclog after the
1412 * unlock as we could race with it being freed.
1414 up(&iclog->ic_sema);
1418 * Return size of each in-core log record buffer.
1420 * All machines get 8 x 32kB buffers by default, unless tuned otherwise.
1422 * If the filesystem blocksize is too large, we may need to choose a
1423 * larger size since the directory code currently logs entire blocks.
1426 xlog_get_iclog_buffer_size(
1427 struct xfs_mount *mp,
1430 if (mp->m_logbufs <= 0)
1431 mp->m_logbufs = XLOG_MAX_ICLOGS;
1432 if (mp->m_logbsize <= 0)
1433 mp->m_logbsize = XLOG_BIG_RECORD_BSIZE;
1435 log->l_iclog_bufs = mp->m_logbufs;
1436 log->l_iclog_size = mp->m_logbsize;
1439 * # headers = size / 32k - one header holds cycles from 32k of data.
1441 log->l_iclog_heads =
1442 DIV_ROUND_UP(mp->m_logbsize, XLOG_HEADER_CYCLE_SIZE);
1443 log->l_iclog_hsize = log->l_iclog_heads << BBSHIFT;
1448 struct xfs_mount *mp)
1450 queue_delayed_work(mp->m_sync_workqueue, &mp->m_log->l_work,
1451 msecs_to_jiffies(xfs_syncd_centisecs * 10));
1455 * Clear the log incompat flags if we have the opportunity.
1457 * This only happens if we're about to log the second dummy transaction as part
1458 * of covering the log and we can get the log incompat feature usage lock.
1461 xlog_clear_incompat(
1464 struct xfs_mount *mp = log->l_mp;
1466 if (!xfs_sb_has_incompat_log_feature(&mp->m_sb,
1467 XFS_SB_FEAT_INCOMPAT_LOG_ALL))
1470 if (log->l_covered_state != XLOG_STATE_COVER_DONE2)
1473 if (!down_write_trylock(&log->l_incompat_users))
1476 xfs_clear_incompat_log_features(mp);
1477 up_write(&log->l_incompat_users);
1481 * Every sync period we need to unpin all items in the AIL and push them to
1482 * disk. If there is nothing dirty, then we might need to cover the log to
1483 * indicate that the filesystem is idle.
1487 struct work_struct *work)
1489 struct xlog *log = container_of(to_delayed_work(work),
1490 struct xlog, l_work);
1491 struct xfs_mount *mp = log->l_mp;
1493 /* dgc: errors ignored - not fatal and nowhere to report them */
1494 if (xfs_fs_writable(mp, SB_FREEZE_WRITE) && xfs_log_need_covered(mp)) {
1496 * Dump a transaction into the log that contains no real change.
1497 * This is needed to stamp the current tail LSN into the log
1498 * during the covering operation.
1500 * We cannot use an inode here for this - that will push dirty
1501 * state back up into the VFS and then periodic inode flushing
1502 * will prevent log covering from making progress. Hence we
1503 * synchronously log the superblock instead to ensure the
1504 * superblock is immediately unpinned and can be written back.
1506 xlog_clear_incompat(log);
1507 xfs_sync_sb(mp, true);
1509 xfs_log_force(mp, 0);
1511 /* start pushing all the metadata that is currently dirty */
1512 xfs_ail_push_all(mp->m_ail);
1514 /* queue us up again */
1515 xfs_log_work_queue(mp);
1519 * This routine initializes some of the log structure for a given mount point.
1520 * Its primary purpose is to fill in enough, so recovery can occur. However,
1521 * some other stuff may be filled in too.
1523 STATIC struct xlog *
1525 struct xfs_mount *mp,
1526 struct xfs_buftarg *log_target,
1527 xfs_daddr_t blk_offset,
1531 xlog_rec_header_t *head;
1532 xlog_in_core_t **iclogp;
1533 xlog_in_core_t *iclog, *prev_iclog=NULL;
1535 int error = -ENOMEM;
1538 log = kmem_zalloc(sizeof(struct xlog), KM_MAYFAIL);
1540 xfs_warn(mp, "Log allocation failed: No memory!");
1545 log->l_targ = log_target;
1546 log->l_logsize = BBTOB(num_bblks);
1547 log->l_logBBstart = blk_offset;
1548 log->l_logBBsize = num_bblks;
1549 log->l_covered_state = XLOG_STATE_COVER_IDLE;
1550 set_bit(XLOG_ACTIVE_RECOVERY, &log->l_opstate);
1551 INIT_DELAYED_WORK(&log->l_work, xfs_log_worker);
1553 log->l_prev_block = -1;
1554 /* log->l_tail_lsn = 0x100000000LL; cycle = 1; current block = 0 */
1555 xlog_assign_atomic_lsn(&log->l_tail_lsn, 1, 0);
1556 xlog_assign_atomic_lsn(&log->l_last_sync_lsn, 1, 0);
1557 log->l_curr_cycle = 1; /* 0 is bad since this is initial value */
1559 if (xfs_has_logv2(mp) && mp->m_sb.sb_logsunit > 1)
1560 log->l_iclog_roundoff = mp->m_sb.sb_logsunit;
1562 log->l_iclog_roundoff = BBSIZE;
1564 xlog_grant_head_init(&log->l_reserve_head);
1565 xlog_grant_head_init(&log->l_write_head);
1567 error = -EFSCORRUPTED;
1568 if (xfs_has_sector(mp)) {
1569 log2_size = mp->m_sb.sb_logsectlog;
1570 if (log2_size < BBSHIFT) {
1571 xfs_warn(mp, "Log sector size too small (0x%x < 0x%x)",
1572 log2_size, BBSHIFT);
1576 log2_size -= BBSHIFT;
1577 if (log2_size > mp->m_sectbb_log) {
1578 xfs_warn(mp, "Log sector size too large (0x%x > 0x%x)",
1579 log2_size, mp->m_sectbb_log);
1583 /* for larger sector sizes, must have v2 or external log */
1584 if (log2_size && log->l_logBBstart > 0 &&
1585 !xfs_has_logv2(mp)) {
1587 "log sector size (0x%x) invalid for configuration.",
1592 log->l_sectBBsize = 1 << log2_size;
1594 init_rwsem(&log->l_incompat_users);
1596 xlog_get_iclog_buffer_size(mp, log);
1598 spin_lock_init(&log->l_icloglock);
1599 init_waitqueue_head(&log->l_flush_wait);
1601 iclogp = &log->l_iclog;
1603 * The amount of memory to allocate for the iclog structure is
1604 * rather funky due to the way the structure is defined. It is
1605 * done this way so that we can use different sizes for machines
1606 * with different amounts of memory. See the definition of
1607 * xlog_in_core_t in xfs_log_priv.h for details.
1609 ASSERT(log->l_iclog_size >= 4096);
1610 for (i = 0; i < log->l_iclog_bufs; i++) {
1611 size_t bvec_size = howmany(log->l_iclog_size, PAGE_SIZE) *
1612 sizeof(struct bio_vec);
1614 iclog = kmem_zalloc(sizeof(*iclog) + bvec_size, KM_MAYFAIL);
1616 goto out_free_iclog;
1619 iclog->ic_prev = prev_iclog;
1622 iclog->ic_data = kvzalloc(log->l_iclog_size,
1623 GFP_KERNEL | __GFP_RETRY_MAYFAIL);
1624 if (!iclog->ic_data)
1625 goto out_free_iclog;
1626 head = &iclog->ic_header;
1627 memset(head, 0, sizeof(xlog_rec_header_t));
1628 head->h_magicno = cpu_to_be32(XLOG_HEADER_MAGIC_NUM);
1629 head->h_version = cpu_to_be32(
1630 xfs_has_logv2(log->l_mp) ? 2 : 1);
1631 head->h_size = cpu_to_be32(log->l_iclog_size);
1633 head->h_fmt = cpu_to_be32(XLOG_FMT);
1634 memcpy(&head->h_fs_uuid, &mp->m_sb.sb_uuid, sizeof(uuid_t));
1636 iclog->ic_size = log->l_iclog_size - log->l_iclog_hsize;
1637 iclog->ic_state = XLOG_STATE_ACTIVE;
1638 iclog->ic_log = log;
1639 atomic_set(&iclog->ic_refcnt, 0);
1640 INIT_LIST_HEAD(&iclog->ic_callbacks);
1641 iclog->ic_datap = (void *)iclog->ic_data + log->l_iclog_hsize;
1643 init_waitqueue_head(&iclog->ic_force_wait);
1644 init_waitqueue_head(&iclog->ic_write_wait);
1645 INIT_WORK(&iclog->ic_end_io_work, xlog_ioend_work);
1646 sema_init(&iclog->ic_sema, 1);
1648 iclogp = &iclog->ic_next;
1650 *iclogp = log->l_iclog; /* complete ring */
1651 log->l_iclog->ic_prev = prev_iclog; /* re-write 1st prev ptr */
1653 log->l_ioend_workqueue = alloc_workqueue("xfs-log/%s",
1654 XFS_WQFLAGS(WQ_FREEZABLE | WQ_MEM_RECLAIM |
1656 0, mp->m_super->s_id);
1657 if (!log->l_ioend_workqueue)
1658 goto out_free_iclog;
1660 error = xlog_cil_init(log);
1662 goto out_destroy_workqueue;
1665 out_destroy_workqueue:
1666 destroy_workqueue(log->l_ioend_workqueue);
1668 for (iclog = log->l_iclog; iclog; iclog = prev_iclog) {
1669 prev_iclog = iclog->ic_next;
1670 kmem_free(iclog->ic_data);
1672 if (prev_iclog == log->l_iclog)
1678 return ERR_PTR(error);
1679 } /* xlog_alloc_log */
1682 * Compute the LSN that we'd need to push the log tail towards in order to have
1683 * (a) enough on-disk log space to log the number of bytes specified, (b) at
1684 * least 25% of the log space free, and (c) at least 256 blocks free. If the
1685 * log free space already meets all three thresholds, this function returns
1689 xlog_grant_push_threshold(
1693 xfs_lsn_t threshold_lsn = 0;
1694 xfs_lsn_t last_sync_lsn;
1697 int threshold_block;
1698 int threshold_cycle;
1701 ASSERT(BTOBB(need_bytes) < log->l_logBBsize);
1703 free_bytes = xlog_space_left(log, &log->l_reserve_head.grant);
1704 free_blocks = BTOBBT(free_bytes);
1707 * Set the threshold for the minimum number of free blocks in the
1708 * log to the maximum of what the caller needs, one quarter of the
1709 * log, and 256 blocks.
1711 free_threshold = BTOBB(need_bytes);
1712 free_threshold = max(free_threshold, (log->l_logBBsize >> 2));
1713 free_threshold = max(free_threshold, 256);
1714 if (free_blocks >= free_threshold)
1715 return NULLCOMMITLSN;
1717 xlog_crack_atomic_lsn(&log->l_tail_lsn, &threshold_cycle,
1719 threshold_block += free_threshold;
1720 if (threshold_block >= log->l_logBBsize) {
1721 threshold_block -= log->l_logBBsize;
1722 threshold_cycle += 1;
1724 threshold_lsn = xlog_assign_lsn(threshold_cycle,
1727 * Don't pass in an lsn greater than the lsn of the last
1728 * log record known to be on disk. Use a snapshot of the last sync lsn
1729 * so that it doesn't change between the compare and the set.
1731 last_sync_lsn = atomic64_read(&log->l_last_sync_lsn);
1732 if (XFS_LSN_CMP(threshold_lsn, last_sync_lsn) > 0)
1733 threshold_lsn = last_sync_lsn;
1735 return threshold_lsn;
1739 * Push the tail of the log if we need to do so to maintain the free log space
1740 * thresholds set out by xlog_grant_push_threshold. We may need to adopt a
1741 * policy which pushes on an lsn which is further along in the log once we
1742 * reach the high water mark. In this manner, we would be creating a low water
1746 xlog_grant_push_ail(
1750 xfs_lsn_t threshold_lsn;
1752 threshold_lsn = xlog_grant_push_threshold(log, need_bytes);
1753 if (threshold_lsn == NULLCOMMITLSN || xlog_is_shutdown(log))
1757 * Get the transaction layer to kick the dirty buffers out to
1758 * disk asynchronously. No point in trying to do this if
1759 * the filesystem is shutting down.
1761 xfs_ail_push(log->l_ailp, threshold_lsn);
1765 * Stamp cycle number in every block
1770 struct xlog_in_core *iclog,
1774 int size = iclog->ic_offset + roundoff;
1778 cycle_lsn = CYCLE_LSN_DISK(iclog->ic_header.h_lsn);
1780 dp = iclog->ic_datap;
1781 for (i = 0; i < BTOBB(size); i++) {
1782 if (i >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE))
1784 iclog->ic_header.h_cycle_data[i] = *(__be32 *)dp;
1785 *(__be32 *)dp = cycle_lsn;
1789 if (xfs_has_logv2(log->l_mp)) {
1790 xlog_in_core_2_t *xhdr = iclog->ic_data;
1792 for ( ; i < BTOBB(size); i++) {
1793 j = i / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
1794 k = i % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
1795 xhdr[j].hic_xheader.xh_cycle_data[k] = *(__be32 *)dp;
1796 *(__be32 *)dp = cycle_lsn;
1800 for (i = 1; i < log->l_iclog_heads; i++)
1801 xhdr[i].hic_xheader.xh_cycle = cycle_lsn;
1806 * Calculate the checksum for a log buffer.
1808 * This is a little more complicated than it should be because the various
1809 * headers and the actual data are non-contiguous.
1814 struct xlog_rec_header *rhead,
1820 /* first generate the crc for the record header ... */
1821 crc = xfs_start_cksum_update((char *)rhead,
1822 sizeof(struct xlog_rec_header),
1823 offsetof(struct xlog_rec_header, h_crc));
1825 /* ... then for additional cycle data for v2 logs ... */
1826 if (xfs_has_logv2(log->l_mp)) {
1827 union xlog_in_core2 *xhdr = (union xlog_in_core2 *)rhead;
1831 xheads = DIV_ROUND_UP(size, XLOG_HEADER_CYCLE_SIZE);
1833 for (i = 1; i < xheads; i++) {
1834 crc = crc32c(crc, &xhdr[i].hic_xheader,
1835 sizeof(struct xlog_rec_ext_header));
1839 /* ... and finally for the payload */
1840 crc = crc32c(crc, dp, size);
1842 return xfs_end_cksum(crc);
1849 struct xlog_in_core *iclog = bio->bi_private;
1851 queue_work(iclog->ic_log->l_ioend_workqueue,
1852 &iclog->ic_end_io_work);
1856 xlog_map_iclog_data(
1862 struct page *page = kmem_to_page(data);
1863 unsigned int off = offset_in_page(data);
1864 size_t len = min_t(size_t, count, PAGE_SIZE - off);
1866 if (bio_add_page(bio, page, len, off) != len)
1879 struct xlog_in_core *iclog,
1883 ASSERT(bno < log->l_logBBsize);
1884 trace_xlog_iclog_write(iclog, _RET_IP_);
1887 * We lock the iclogbufs here so that we can serialise against I/O
1888 * completion during unmount. We might be processing a shutdown
1889 * triggered during unmount, and that can occur asynchronously to the
1890 * unmount thread, and hence we need to ensure that completes before
1891 * tearing down the iclogbufs. Hence we need to hold the buffer lock
1892 * across the log IO to archieve that.
1894 down(&iclog->ic_sema);
1895 if (xlog_is_shutdown(log)) {
1897 * It would seem logical to return EIO here, but we rely on
1898 * the log state machine to propagate I/O errors instead of
1899 * doing it here. We kick of the state machine and unlock
1900 * the buffer manually, the code needs to be kept in sync
1901 * with the I/O completion path.
1903 xlog_state_done_syncing(iclog);
1904 up(&iclog->ic_sema);
1909 * We use REQ_SYNC | REQ_IDLE here to tell the block layer the are more
1910 * IOs coming immediately after this one. This prevents the block layer
1911 * writeback throttle from throttling log writes behind background
1912 * metadata writeback and causing priority inversions.
1914 bio_init(&iclog->ic_bio, log->l_targ->bt_bdev, iclog->ic_bvec,
1915 howmany(count, PAGE_SIZE),
1916 REQ_OP_WRITE | REQ_META | REQ_SYNC | REQ_IDLE);
1917 iclog->ic_bio.bi_iter.bi_sector = log->l_logBBstart + bno;
1918 iclog->ic_bio.bi_end_io = xlog_bio_end_io;
1919 iclog->ic_bio.bi_private = iclog;
1921 if (iclog->ic_flags & XLOG_ICL_NEED_FLUSH) {
1922 iclog->ic_bio.bi_opf |= REQ_PREFLUSH;
1924 * For external log devices, we also need to flush the data
1925 * device cache first to ensure all metadata writeback covered
1926 * by the LSN in this iclog is on stable storage. This is slow,
1927 * but it *must* complete before we issue the external log IO.
1929 * If the flush fails, we cannot conclude that past metadata
1930 * writeback from the log succeeded. Repeating the flush is
1931 * not possible, hence we must shut down with log IO error to
1932 * avoid shutdown re-entering this path and erroring out again.
1934 if (log->l_targ != log->l_mp->m_ddev_targp &&
1935 blkdev_issue_flush(log->l_mp->m_ddev_targp->bt_bdev)) {
1936 xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR);
1940 if (iclog->ic_flags & XLOG_ICL_NEED_FUA)
1941 iclog->ic_bio.bi_opf |= REQ_FUA;
1943 iclog->ic_flags &= ~(XLOG_ICL_NEED_FLUSH | XLOG_ICL_NEED_FUA);
1945 if (xlog_map_iclog_data(&iclog->ic_bio, iclog->ic_data, count)) {
1946 xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR);
1949 if (is_vmalloc_addr(iclog->ic_data))
1950 flush_kernel_vmap_range(iclog->ic_data, count);
1953 * If this log buffer would straddle the end of the log we will have
1954 * to split it up into two bios, so that we can continue at the start.
1956 if (bno + BTOBB(count) > log->l_logBBsize) {
1959 split = bio_split(&iclog->ic_bio, log->l_logBBsize - bno,
1960 GFP_NOIO, &fs_bio_set);
1961 bio_chain(split, &iclog->ic_bio);
1964 /* restart at logical offset zero for the remainder */
1965 iclog->ic_bio.bi_iter.bi_sector = log->l_logBBstart;
1968 submit_bio(&iclog->ic_bio);
1972 * We need to bump cycle number for the part of the iclog that is
1973 * written to the start of the log. Watch out for the header magic
1974 * number case, though.
1983 unsigned int split_offset = BBTOB(log->l_logBBsize - bno);
1986 for (i = split_offset; i < count; i += BBSIZE) {
1987 uint32_t cycle = get_unaligned_be32(data + i);
1989 if (++cycle == XLOG_HEADER_MAGIC_NUM)
1991 put_unaligned_be32(cycle, data + i);
1996 xlog_calc_iclog_size(
1998 struct xlog_in_core *iclog,
2001 uint32_t count_init, count;
2003 /* Add for LR header */
2004 count_init = log->l_iclog_hsize + iclog->ic_offset;
2005 count = roundup(count_init, log->l_iclog_roundoff);
2007 *roundoff = count - count_init;
2009 ASSERT(count >= count_init);
2010 ASSERT(*roundoff < log->l_iclog_roundoff);
2015 * Flush out the in-core log (iclog) to the on-disk log in an asynchronous
2016 * fashion. Previously, we should have moved the current iclog
2017 * ptr in the log to point to the next available iclog. This allows further
2018 * write to continue while this code syncs out an iclog ready to go.
2019 * Before an in-core log can be written out, the data section must be scanned
2020 * to save away the 1st word of each BBSIZE block into the header. We replace
2021 * it with the current cycle count. Each BBSIZE block is tagged with the
2022 * cycle count because there in an implicit assumption that drives will
2023 * guarantee that entire 512 byte blocks get written at once. In other words,
2024 * we can't have part of a 512 byte block written and part not written. By
2025 * tagging each block, we will know which blocks are valid when recovering
2026 * after an unclean shutdown.
2028 * This routine is single threaded on the iclog. No other thread can be in
2029 * this routine with the same iclog. Changing contents of iclog can there-
2030 * fore be done without grabbing the state machine lock. Updating the global
2031 * log will require grabbing the lock though.
2033 * The entire log manager uses a logical block numbering scheme. Only
2034 * xlog_write_iclog knows about the fact that the log may not start with
2035 * block zero on a given device.
2040 struct xlog_in_core *iclog,
2041 struct xlog_ticket *ticket)
2043 unsigned int count; /* byte count of bwrite */
2044 unsigned int roundoff; /* roundoff to BB or stripe */
2048 ASSERT(atomic_read(&iclog->ic_refcnt) == 0);
2049 trace_xlog_iclog_sync(iclog, _RET_IP_);
2051 count = xlog_calc_iclog_size(log, iclog, &roundoff);
2054 * If we have a ticket, account for the roundoff via the ticket
2055 * reservation to avoid touching the hot grant heads needlessly.
2056 * Otherwise, we have to move grant heads directly.
2059 ticket->t_curr_res -= roundoff;
2061 xlog_grant_add_space(log, &log->l_reserve_head.grant, roundoff);
2062 xlog_grant_add_space(log, &log->l_write_head.grant, roundoff);
2065 /* put cycle number in every block */
2066 xlog_pack_data(log, iclog, roundoff);
2068 /* real byte length */
2069 size = iclog->ic_offset;
2070 if (xfs_has_logv2(log->l_mp))
2072 iclog->ic_header.h_len = cpu_to_be32(size);
2074 XFS_STATS_INC(log->l_mp, xs_log_writes);
2075 XFS_STATS_ADD(log->l_mp, xs_log_blocks, BTOBB(count));
2077 bno = BLOCK_LSN(be64_to_cpu(iclog->ic_header.h_lsn));
2079 /* Do we need to split this write into 2 parts? */
2080 if (bno + BTOBB(count) > log->l_logBBsize)
2081 xlog_split_iclog(log, &iclog->ic_header, bno, count);
2083 /* calculcate the checksum */
2084 iclog->ic_header.h_crc = xlog_cksum(log, &iclog->ic_header,
2085 iclog->ic_datap, size);
2087 * Intentionally corrupt the log record CRC based on the error injection
2088 * frequency, if defined. This facilitates testing log recovery in the
2089 * event of torn writes. Hence, set the IOABORT state to abort the log
2090 * write on I/O completion and shutdown the fs. The subsequent mount
2091 * detects the bad CRC and attempts to recover.
2094 if (XFS_TEST_ERROR(false, log->l_mp, XFS_ERRTAG_LOG_BAD_CRC)) {
2095 iclog->ic_header.h_crc &= cpu_to_le32(0xAAAAAAAA);
2096 iclog->ic_fail_crc = true;
2098 "Intentionally corrupted log record at LSN 0x%llx. Shutdown imminent.",
2099 be64_to_cpu(iclog->ic_header.h_lsn));
2102 xlog_verify_iclog(log, iclog, count);
2103 xlog_write_iclog(log, iclog, bno, count);
2107 * Deallocate a log structure
2113 xlog_in_core_t *iclog, *next_iclog;
2117 * Cycle all the iclogbuf locks to make sure all log IO completion
2118 * is done before we tear down these buffers.
2120 iclog = log->l_iclog;
2121 for (i = 0; i < log->l_iclog_bufs; i++) {
2122 down(&iclog->ic_sema);
2123 up(&iclog->ic_sema);
2124 iclog = iclog->ic_next;
2128 * Destroy the CIL after waiting for iclog IO completion because an
2129 * iclog EIO error will try to shut down the log, which accesses the
2130 * CIL to wake up the waiters.
2132 xlog_cil_destroy(log);
2134 iclog = log->l_iclog;
2135 for (i = 0; i < log->l_iclog_bufs; i++) {
2136 next_iclog = iclog->ic_next;
2137 kmem_free(iclog->ic_data);
2142 log->l_mp->m_log = NULL;
2143 destroy_workqueue(log->l_ioend_workqueue);
2148 * Update counters atomically now that memcpy is done.
2151 xlog_state_finish_copy(
2153 struct xlog_in_core *iclog,
2157 lockdep_assert_held(&log->l_icloglock);
2159 be32_add_cpu(&iclog->ic_header.h_num_logops, record_cnt);
2160 iclog->ic_offset += copy_bytes;
2164 * print out info relating to regions written which consume
2169 struct xfs_mount *mp,
2170 struct xlog_ticket *ticket)
2172 xfs_warn(mp, "ticket reservation summary:");
2173 xfs_warn(mp, " unit res = %d bytes", ticket->t_unit_res);
2174 xfs_warn(mp, " current res = %d bytes", ticket->t_curr_res);
2175 xfs_warn(mp, " original count = %d", ticket->t_ocnt);
2176 xfs_warn(mp, " remaining count = %d", ticket->t_cnt);
2180 * Print a summary of the transaction.
2184 struct xfs_trans *tp)
2186 struct xfs_mount *mp = tp->t_mountp;
2187 struct xfs_log_item *lip;
2189 /* dump core transaction and ticket info */
2190 xfs_warn(mp, "transaction summary:");
2191 xfs_warn(mp, " log res = %d", tp->t_log_res);
2192 xfs_warn(mp, " log count = %d", tp->t_log_count);
2193 xfs_warn(mp, " flags = 0x%x", tp->t_flags);
2195 xlog_print_tic_res(mp, tp->t_ticket);
2197 /* dump each log item */
2198 list_for_each_entry(lip, &tp->t_items, li_trans) {
2199 struct xfs_log_vec *lv = lip->li_lv;
2200 struct xfs_log_iovec *vec;
2203 xfs_warn(mp, "log item: ");
2204 xfs_warn(mp, " type = 0x%x", lip->li_type);
2205 xfs_warn(mp, " flags = 0x%lx", lip->li_flags);
2208 xfs_warn(mp, " niovecs = %d", lv->lv_niovecs);
2209 xfs_warn(mp, " size = %d", lv->lv_size);
2210 xfs_warn(mp, " bytes = %d", lv->lv_bytes);
2211 xfs_warn(mp, " buf len = %d", lv->lv_buf_len);
2213 /* dump each iovec for the log item */
2214 vec = lv->lv_iovecp;
2215 for (i = 0; i < lv->lv_niovecs; i++) {
2216 int dumplen = min(vec->i_len, 32);
2218 xfs_warn(mp, " iovec[%d]", i);
2219 xfs_warn(mp, " type = 0x%x", vec->i_type);
2220 xfs_warn(mp, " len = %d", vec->i_len);
2221 xfs_warn(mp, " first %d bytes of iovec[%d]:", dumplen, i);
2222 xfs_hex_dump(vec->i_addr, dumplen);
2231 struct xlog_in_core *iclog,
2232 uint32_t *log_offset,
2236 uint32_t *record_cnt,
2239 ASSERT(*log_offset < iclog->ic_log->l_iclog_size);
2240 ASSERT(*log_offset % sizeof(int32_t) == 0);
2241 ASSERT(write_len % sizeof(int32_t) == 0);
2243 memcpy(iclog->ic_datap + *log_offset, data, write_len);
2244 *log_offset += write_len;
2245 *bytes_left -= write_len;
2247 *data_cnt += write_len;
2251 * Write log vectors into a single iclog which is guaranteed by the caller
2252 * to have enough space to write the entire log vector into.
2256 struct xfs_log_vec *lv,
2257 struct xlog_ticket *ticket,
2258 struct xlog_in_core *iclog,
2259 uint32_t *log_offset,
2261 uint32_t *record_cnt,
2266 ASSERT(*log_offset + *len <= iclog->ic_size ||
2267 iclog->ic_state == XLOG_STATE_WANT_SYNC);
2270 * Ordered log vectors have no regions to write so this
2271 * loop will naturally skip them.
2273 for (index = 0; index < lv->lv_niovecs; index++) {
2274 struct xfs_log_iovec *reg = &lv->lv_iovecp[index];
2275 struct xlog_op_header *ophdr = reg->i_addr;
2277 ophdr->oh_tid = cpu_to_be32(ticket->t_tid);
2278 xlog_write_iovec(iclog, log_offset, reg->i_addr,
2279 reg->i_len, len, record_cnt, data_cnt);
2284 xlog_write_get_more_iclog_space(
2285 struct xlog_ticket *ticket,
2286 struct xlog_in_core **iclogp,
2287 uint32_t *log_offset,
2289 uint32_t *record_cnt,
2292 struct xlog_in_core *iclog = *iclogp;
2293 struct xlog *log = iclog->ic_log;
2296 spin_lock(&log->l_icloglock);
2297 ASSERT(iclog->ic_state == XLOG_STATE_WANT_SYNC);
2298 xlog_state_finish_copy(log, iclog, *record_cnt, *data_cnt);
2299 error = xlog_state_release_iclog(log, iclog, ticket);
2300 spin_unlock(&log->l_icloglock);
2304 error = xlog_state_get_iclog_space(log, len, &iclog, ticket,
2315 * Write log vectors into a single iclog which is smaller than the current chain
2316 * length. We write until we cannot fit a full record into the remaining space
2317 * and then stop. We return the log vector that is to be written that cannot
2318 * wholly fit in the iclog.
2322 struct xfs_log_vec *lv,
2323 struct xlog_ticket *ticket,
2324 struct xlog_in_core **iclogp,
2325 uint32_t *log_offset,
2327 uint32_t *record_cnt,
2330 struct xlog_in_core *iclog = *iclogp;
2331 struct xlog_op_header *ophdr;
2336 /* walk the logvec, copying until we run out of space in the iclog */
2337 for (index = 0; index < lv->lv_niovecs; index++) {
2338 struct xfs_log_iovec *reg = &lv->lv_iovecp[index];
2339 uint32_t reg_offset = 0;
2342 * The first region of a continuation must have a non-zero
2343 * length otherwise log recovery will just skip over it and
2344 * start recovering from the next opheader it finds. Because we
2345 * mark the next opheader as a continuation, recovery will then
2346 * incorrectly add the continuation to the previous region and
2347 * that breaks stuff.
2349 * Hence if there isn't space for region data after the
2350 * opheader, then we need to start afresh with a new iclog.
2352 if (iclog->ic_size - *log_offset <=
2353 sizeof(struct xlog_op_header)) {
2354 error = xlog_write_get_more_iclog_space(ticket,
2355 &iclog, log_offset, *len, record_cnt,
2361 ophdr = reg->i_addr;
2362 rlen = min_t(uint32_t, reg->i_len, iclog->ic_size - *log_offset);
2364 ophdr->oh_tid = cpu_to_be32(ticket->t_tid);
2365 ophdr->oh_len = cpu_to_be32(rlen - sizeof(struct xlog_op_header));
2366 if (rlen != reg->i_len)
2367 ophdr->oh_flags |= XLOG_CONTINUE_TRANS;
2369 xlog_write_iovec(iclog, log_offset, reg->i_addr,
2370 rlen, len, record_cnt, data_cnt);
2372 /* If we wrote the whole region, move to the next. */
2373 if (rlen == reg->i_len)
2377 * We now have a partially written iovec, but it can span
2378 * multiple iclogs so we loop here. First we release the iclog
2379 * we currently have, then we get a new iclog and add a new
2380 * opheader. Then we continue copying from where we were until
2381 * we either complete the iovec or fill the iclog. If we
2382 * complete the iovec, then we increment the index and go right
2383 * back to the top of the outer loop. if we fill the iclog, we
2384 * run the inner loop again.
2386 * This is complicated by the tail of a region using all the
2387 * space in an iclog and hence requiring us to release the iclog
2388 * and get a new one before returning to the outer loop. We must
2389 * always guarantee that we exit this inner loop with at least
2390 * space for log transaction opheaders left in the current
2391 * iclog, hence we cannot just terminate the loop at the end
2392 * of the of the continuation. So we loop while there is no
2393 * space left in the current iclog, and check for the end of the
2394 * continuation after getting a new iclog.
2398 * Ensure we include the continuation opheader in the
2399 * space we need in the new iclog by adding that size
2400 * to the length we require. This continuation opheader
2401 * needs to be accounted to the ticket as the space it
2402 * consumes hasn't been accounted to the lv we are
2405 error = xlog_write_get_more_iclog_space(ticket,
2407 *len + sizeof(struct xlog_op_header),
2408 record_cnt, data_cnt);
2412 ophdr = iclog->ic_datap + *log_offset;
2413 ophdr->oh_tid = cpu_to_be32(ticket->t_tid);
2414 ophdr->oh_clientid = XFS_TRANSACTION;
2416 ophdr->oh_flags = XLOG_WAS_CONT_TRANS;
2418 ticket->t_curr_res -= sizeof(struct xlog_op_header);
2419 *log_offset += sizeof(struct xlog_op_header);
2420 *data_cnt += sizeof(struct xlog_op_header);
2423 * If rlen fits in the iclog, then end the region
2424 * continuation. Otherwise we're going around again.
2427 rlen = reg->i_len - reg_offset;
2428 if (rlen <= iclog->ic_size - *log_offset)
2429 ophdr->oh_flags |= XLOG_END_TRANS;
2431 ophdr->oh_flags |= XLOG_CONTINUE_TRANS;
2433 rlen = min_t(uint32_t, rlen, iclog->ic_size - *log_offset);
2434 ophdr->oh_len = cpu_to_be32(rlen);
2436 xlog_write_iovec(iclog, log_offset,
2437 reg->i_addr + reg_offset,
2438 rlen, len, record_cnt, data_cnt);
2440 } while (ophdr->oh_flags & XLOG_CONTINUE_TRANS);
2444 * No more iovecs remain in this logvec so return the next log vec to
2445 * the caller so it can go back to fast path copying.
2452 * Write some region out to in-core log
2454 * This will be called when writing externally provided regions or when
2455 * writing out a commit record for a given transaction.
2457 * General algorithm:
2458 * 1. Find total length of this write. This may include adding to the
2459 * lengths passed in.
2460 * 2. Check whether we violate the tickets reservation.
2461 * 3. While writing to this iclog
2462 * A. Reserve as much space in this iclog as can get
2463 * B. If this is first write, save away start lsn
2464 * C. While writing this region:
2465 * 1. If first write of transaction, write start record
2466 * 2. Write log operation header (header per region)
2467 * 3. Find out if we can fit entire region into this iclog
2468 * 4. Potentially, verify destination memcpy ptr
2469 * 5. Memcpy (partial) region
2470 * 6. If partial copy, release iclog; otherwise, continue
2471 * copying more regions into current iclog
2472 * 4. Mark want sync bit (in simulation mode)
2473 * 5. Release iclog for potential flush to on-disk log.
2476 * 1. Panic if reservation is overrun. This should never happen since
2477 * reservation amounts are generated internal to the filesystem.
2479 * 1. Tickets are single threaded data structures.
2480 * 2. The XLOG_END_TRANS & XLOG_CONTINUE_TRANS flags are passed down to the
2481 * syncing routine. When a single log_write region needs to span
2482 * multiple in-core logs, the XLOG_CONTINUE_TRANS bit should be set
2483 * on all log operation writes which don't contain the end of the
2484 * region. The XLOG_END_TRANS bit is used for the in-core log
2485 * operation which contains the end of the continued log_write region.
2486 * 3. When xlog_state_get_iclog_space() grabs the rest of the current iclog,
2487 * we don't really know exactly how much space will be used. As a result,
2488 * we don't update ic_offset until the end when we know exactly how many
2489 * bytes have been written out.
2494 struct xfs_cil_ctx *ctx,
2495 struct list_head *lv_chain,
2496 struct xlog_ticket *ticket,
2500 struct xlog_in_core *iclog = NULL;
2501 struct xfs_log_vec *lv;
2502 uint32_t record_cnt = 0;
2503 uint32_t data_cnt = 0;
2507 if (ticket->t_curr_res < 0) {
2508 xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES,
2509 "ctx ticket reservation ran out. Need to up reservation");
2510 xlog_print_tic_res(log->l_mp, ticket);
2511 xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR);
2514 error = xlog_state_get_iclog_space(log, len, &iclog, ticket,
2519 ASSERT(log_offset <= iclog->ic_size - 1);
2522 * If we have a context pointer, pass it the first iclog we are
2523 * writing to so it can record state needed for iclog write
2527 xlog_cil_set_ctx_write_state(ctx, iclog);
2529 list_for_each_entry(lv, lv_chain, lv_list) {
2531 * If the entire log vec does not fit in the iclog, punt it to
2532 * the partial copy loop which can handle this case.
2534 if (lv->lv_niovecs &&
2535 lv->lv_bytes > iclog->ic_size - log_offset) {
2536 error = xlog_write_partial(lv, ticket, &iclog,
2537 &log_offset, &len, &record_cnt,
2541 * We have no iclog to release, so just return
2542 * the error immediately.
2547 xlog_write_full(lv, ticket, iclog, &log_offset,
2548 &len, &record_cnt, &data_cnt);
2554 * We've already been guaranteed that the last writes will fit inside
2555 * the current iclog, and hence it will already have the space used by
2556 * those writes accounted to it. Hence we do not need to update the
2557 * iclog with the number of bytes written here.
2559 spin_lock(&log->l_icloglock);
2560 xlog_state_finish_copy(log, iclog, record_cnt, 0);
2561 error = xlog_state_release_iclog(log, iclog, ticket);
2562 spin_unlock(&log->l_icloglock);
2568 xlog_state_activate_iclog(
2569 struct xlog_in_core *iclog,
2570 int *iclogs_changed)
2572 ASSERT(list_empty_careful(&iclog->ic_callbacks));
2573 trace_xlog_iclog_activate(iclog, _RET_IP_);
2576 * If the number of ops in this iclog indicate it just contains the
2577 * dummy transaction, we can change state into IDLE (the second time
2578 * around). Otherwise we should change the state into NEED a dummy.
2579 * We don't need to cover the dummy.
2581 if (*iclogs_changed == 0 &&
2582 iclog->ic_header.h_num_logops == cpu_to_be32(XLOG_COVER_OPS)) {
2583 *iclogs_changed = 1;
2586 * We have two dirty iclogs so start over. This could also be
2587 * num of ops indicating this is not the dummy going out.
2589 *iclogs_changed = 2;
2592 iclog->ic_state = XLOG_STATE_ACTIVE;
2593 iclog->ic_offset = 0;
2594 iclog->ic_header.h_num_logops = 0;
2595 memset(iclog->ic_header.h_cycle_data, 0,
2596 sizeof(iclog->ic_header.h_cycle_data));
2597 iclog->ic_header.h_lsn = 0;
2598 iclog->ic_header.h_tail_lsn = 0;
2602 * Loop through all iclogs and mark all iclogs currently marked DIRTY as
2603 * ACTIVE after iclog I/O has completed.
2606 xlog_state_activate_iclogs(
2608 int *iclogs_changed)
2610 struct xlog_in_core *iclog = log->l_iclog;
2613 if (iclog->ic_state == XLOG_STATE_DIRTY)
2614 xlog_state_activate_iclog(iclog, iclogs_changed);
2616 * The ordering of marking iclogs ACTIVE must be maintained, so
2617 * an iclog doesn't become ACTIVE beyond one that is SYNCING.
2619 else if (iclog->ic_state != XLOG_STATE_ACTIVE)
2621 } while ((iclog = iclog->ic_next) != log->l_iclog);
2630 * We go to NEED for any non-covering writes. We go to NEED2 if we just
2631 * wrote the first covering record (DONE). We go to IDLE if we just
2632 * wrote the second covering record (DONE2) and remain in IDLE until a
2633 * non-covering write occurs.
2635 switch (prev_state) {
2636 case XLOG_STATE_COVER_IDLE:
2637 if (iclogs_changed == 1)
2638 return XLOG_STATE_COVER_IDLE;
2640 case XLOG_STATE_COVER_NEED:
2641 case XLOG_STATE_COVER_NEED2:
2643 case XLOG_STATE_COVER_DONE:
2644 if (iclogs_changed == 1)
2645 return XLOG_STATE_COVER_NEED2;
2647 case XLOG_STATE_COVER_DONE2:
2648 if (iclogs_changed == 1)
2649 return XLOG_STATE_COVER_IDLE;
2655 return XLOG_STATE_COVER_NEED;
2659 xlog_state_clean_iclog(
2661 struct xlog_in_core *dirty_iclog)
2663 int iclogs_changed = 0;
2665 trace_xlog_iclog_clean(dirty_iclog, _RET_IP_);
2667 dirty_iclog->ic_state = XLOG_STATE_DIRTY;
2669 xlog_state_activate_iclogs(log, &iclogs_changed);
2670 wake_up_all(&dirty_iclog->ic_force_wait);
2672 if (iclogs_changed) {
2673 log->l_covered_state = xlog_covered_state(log->l_covered_state,
2679 xlog_get_lowest_lsn(
2682 struct xlog_in_core *iclog = log->l_iclog;
2683 xfs_lsn_t lowest_lsn = 0, lsn;
2686 if (iclog->ic_state == XLOG_STATE_ACTIVE ||
2687 iclog->ic_state == XLOG_STATE_DIRTY)
2690 lsn = be64_to_cpu(iclog->ic_header.h_lsn);
2691 if ((lsn && !lowest_lsn) || XFS_LSN_CMP(lsn, lowest_lsn) < 0)
2693 } while ((iclog = iclog->ic_next) != log->l_iclog);
2699 * Completion of a iclog IO does not imply that a transaction has completed, as
2700 * transactions can be large enough to span many iclogs. We cannot change the
2701 * tail of the log half way through a transaction as this may be the only
2702 * transaction in the log and moving the tail to point to the middle of it
2703 * will prevent recovery from finding the start of the transaction. Hence we
2704 * should only update the last_sync_lsn if this iclog contains transaction
2705 * completion callbacks on it.
2707 * We have to do this before we drop the icloglock to ensure we are the only one
2708 * that can update it.
2710 * If we are moving the last_sync_lsn forwards, we also need to ensure we kick
2711 * the reservation grant head pushing. This is due to the fact that the push
2712 * target is bound by the current last_sync_lsn value. Hence if we have a large
2713 * amount of log space bound up in this committing transaction then the
2714 * last_sync_lsn value may be the limiting factor preventing tail pushing from
2715 * freeing space in the log. Hence once we've updated the last_sync_lsn we
2716 * should push the AIL to ensure the push target (and hence the grant head) is
2717 * no longer bound by the old log head location and can move forwards and make
2721 xlog_state_set_callback(
2723 struct xlog_in_core *iclog,
2724 xfs_lsn_t header_lsn)
2726 trace_xlog_iclog_callback(iclog, _RET_IP_);
2727 iclog->ic_state = XLOG_STATE_CALLBACK;
2729 ASSERT(XFS_LSN_CMP(atomic64_read(&log->l_last_sync_lsn),
2732 if (list_empty_careful(&iclog->ic_callbacks))
2735 atomic64_set(&log->l_last_sync_lsn, header_lsn);
2736 xlog_grant_push_ail(log, 0);
2740 * Return true if we need to stop processing, false to continue to the next
2741 * iclog. The caller will need to run callbacks if the iclog is returned in the
2742 * XLOG_STATE_CALLBACK state.
2745 xlog_state_iodone_process_iclog(
2747 struct xlog_in_core *iclog)
2749 xfs_lsn_t lowest_lsn;
2750 xfs_lsn_t header_lsn;
2752 switch (iclog->ic_state) {
2753 case XLOG_STATE_ACTIVE:
2754 case XLOG_STATE_DIRTY:
2756 * Skip all iclogs in the ACTIVE & DIRTY states:
2759 case XLOG_STATE_DONE_SYNC:
2761 * Now that we have an iclog that is in the DONE_SYNC state, do
2762 * one more check here to see if we have chased our tail around.
2763 * If this is not the lowest lsn iclog, then we will leave it
2764 * for another completion to process.
2766 header_lsn = be64_to_cpu(iclog->ic_header.h_lsn);
2767 lowest_lsn = xlog_get_lowest_lsn(log);
2768 if (lowest_lsn && XFS_LSN_CMP(lowest_lsn, header_lsn) < 0)
2770 xlog_state_set_callback(log, iclog, header_lsn);
2774 * Can only perform callbacks in order. Since this iclog is not
2775 * in the DONE_SYNC state, we skip the rest and just try to
2783 * Loop over all the iclogs, running attached callbacks on them. Return true if
2784 * we ran any callbacks, indicating that we dropped the icloglock. We don't need
2785 * to handle transient shutdown state here at all because
2786 * xlog_state_shutdown_callbacks() will be run to do the necessary shutdown
2787 * cleanup of the callbacks.
2790 xlog_state_do_iclog_callbacks(
2792 __releases(&log->l_icloglock)
2793 __acquires(&log->l_icloglock)
2795 struct xlog_in_core *first_iclog = log->l_iclog;
2796 struct xlog_in_core *iclog = first_iclog;
2797 bool ran_callback = false;
2802 if (xlog_state_iodone_process_iclog(log, iclog))
2804 if (iclog->ic_state != XLOG_STATE_CALLBACK) {
2805 iclog = iclog->ic_next;
2808 list_splice_init(&iclog->ic_callbacks, &cb_list);
2809 spin_unlock(&log->l_icloglock);
2811 trace_xlog_iclog_callbacks_start(iclog, _RET_IP_);
2812 xlog_cil_process_committed(&cb_list);
2813 trace_xlog_iclog_callbacks_done(iclog, _RET_IP_);
2814 ran_callback = true;
2816 spin_lock(&log->l_icloglock);
2817 xlog_state_clean_iclog(log, iclog);
2818 iclog = iclog->ic_next;
2819 } while (iclog != first_iclog);
2821 return ran_callback;
2826 * Loop running iclog completion callbacks until there are no more iclogs in a
2827 * state that can run callbacks.
2830 xlog_state_do_callback(
2836 spin_lock(&log->l_icloglock);
2837 while (xlog_state_do_iclog_callbacks(log)) {
2838 if (xlog_is_shutdown(log))
2841 if (++repeats > 5000) {
2842 flushcnt += repeats;
2845 "%s: possible infinite loop (%d iterations)",
2846 __func__, flushcnt);
2850 if (log->l_iclog->ic_state == XLOG_STATE_ACTIVE)
2851 wake_up_all(&log->l_flush_wait);
2853 spin_unlock(&log->l_icloglock);
2858 * Finish transitioning this iclog to the dirty state.
2860 * Callbacks could take time, so they are done outside the scope of the
2861 * global state machine log lock.
2864 xlog_state_done_syncing(
2865 struct xlog_in_core *iclog)
2867 struct xlog *log = iclog->ic_log;
2869 spin_lock(&log->l_icloglock);
2870 ASSERT(atomic_read(&iclog->ic_refcnt) == 0);
2871 trace_xlog_iclog_sync_done(iclog, _RET_IP_);
2874 * If we got an error, either on the first buffer, or in the case of
2875 * split log writes, on the second, we shut down the file system and
2876 * no iclogs should ever be attempted to be written to disk again.
2878 if (!xlog_is_shutdown(log)) {
2879 ASSERT(iclog->ic_state == XLOG_STATE_SYNCING);
2880 iclog->ic_state = XLOG_STATE_DONE_SYNC;
2884 * Someone could be sleeping prior to writing out the next
2885 * iclog buffer, we wake them all, one will get to do the
2886 * I/O, the others get to wait for the result.
2888 wake_up_all(&iclog->ic_write_wait);
2889 spin_unlock(&log->l_icloglock);
2890 xlog_state_do_callback(log);
2894 * If the head of the in-core log ring is not (ACTIVE or DIRTY), then we must
2895 * sleep. We wait on the flush queue on the head iclog as that should be
2896 * the first iclog to complete flushing. Hence if all iclogs are syncing,
2897 * we will wait here and all new writes will sleep until a sync completes.
2899 * The in-core logs are used in a circular fashion. They are not used
2900 * out-of-order even when an iclog past the head is free.
2903 * * log_offset where xlog_write() can start writing into the in-core
2905 * * in-core log pointer to which xlog_write() should write.
2906 * * boolean indicating this is a continued write to an in-core log.
2907 * If this is the last write, then the in-core log's offset field
2908 * needs to be incremented, depending on the amount of data which
2912 xlog_state_get_iclog_space(
2915 struct xlog_in_core **iclogp,
2916 struct xlog_ticket *ticket,
2920 xlog_rec_header_t *head;
2921 xlog_in_core_t *iclog;
2924 spin_lock(&log->l_icloglock);
2925 if (xlog_is_shutdown(log)) {
2926 spin_unlock(&log->l_icloglock);
2930 iclog = log->l_iclog;
2931 if (iclog->ic_state != XLOG_STATE_ACTIVE) {
2932 XFS_STATS_INC(log->l_mp, xs_log_noiclogs);
2934 /* Wait for log writes to have flushed */
2935 xlog_wait(&log->l_flush_wait, &log->l_icloglock);
2939 head = &iclog->ic_header;
2941 atomic_inc(&iclog->ic_refcnt); /* prevents sync */
2942 log_offset = iclog->ic_offset;
2944 trace_xlog_iclog_get_space(iclog, _RET_IP_);
2946 /* On the 1st write to an iclog, figure out lsn. This works
2947 * if iclogs marked XLOG_STATE_WANT_SYNC always write out what they are
2948 * committing to. If the offset is set, that's how many blocks
2951 if (log_offset == 0) {
2952 ticket->t_curr_res -= log->l_iclog_hsize;
2953 head->h_cycle = cpu_to_be32(log->l_curr_cycle);
2954 head->h_lsn = cpu_to_be64(
2955 xlog_assign_lsn(log->l_curr_cycle, log->l_curr_block));
2956 ASSERT(log->l_curr_block >= 0);
2959 /* If there is enough room to write everything, then do it. Otherwise,
2960 * claim the rest of the region and make sure the XLOG_STATE_WANT_SYNC
2961 * bit is on, so this will get flushed out. Don't update ic_offset
2962 * until you know exactly how many bytes get copied. Therefore, wait
2963 * until later to update ic_offset.
2965 * xlog_write() algorithm assumes that at least 2 xlog_op_header_t's
2966 * can fit into remaining data section.
2968 if (iclog->ic_size - iclog->ic_offset < 2*sizeof(xlog_op_header_t)) {
2971 xlog_state_switch_iclogs(log, iclog, iclog->ic_size);
2974 * If we are the only one writing to this iclog, sync it to
2975 * disk. We need to do an atomic compare and decrement here to
2976 * avoid racing with concurrent atomic_dec_and_lock() calls in
2977 * xlog_state_release_iclog() when there is more than one
2978 * reference to the iclog.
2980 if (!atomic_add_unless(&iclog->ic_refcnt, -1, 1))
2981 error = xlog_state_release_iclog(log, iclog, ticket);
2982 spin_unlock(&log->l_icloglock);
2988 /* Do we have enough room to write the full amount in the remainder
2989 * of this iclog? Or must we continue a write on the next iclog and
2990 * mark this iclog as completely taken? In the case where we switch
2991 * iclogs (to mark it taken), this particular iclog will release/sync
2992 * to disk in xlog_write().
2994 if (len <= iclog->ic_size - iclog->ic_offset)
2995 iclog->ic_offset += len;
2997 xlog_state_switch_iclogs(log, iclog, iclog->ic_size);
3000 ASSERT(iclog->ic_offset <= iclog->ic_size);
3001 spin_unlock(&log->l_icloglock);
3003 *logoffsetp = log_offset;
3008 * The first cnt-1 times a ticket goes through here we don't need to move the
3009 * grant write head because the permanent reservation has reserved cnt times the
3010 * unit amount. Release part of current permanent unit reservation and reset
3011 * current reservation to be one units worth. Also move grant reservation head
3015 xfs_log_ticket_regrant(
3017 struct xlog_ticket *ticket)
3019 trace_xfs_log_ticket_regrant(log, ticket);
3021 if (ticket->t_cnt > 0)
3024 xlog_grant_sub_space(log, &log->l_reserve_head.grant,
3025 ticket->t_curr_res);
3026 xlog_grant_sub_space(log, &log->l_write_head.grant,
3027 ticket->t_curr_res);
3028 ticket->t_curr_res = ticket->t_unit_res;
3030 trace_xfs_log_ticket_regrant_sub(log, ticket);
3032 /* just return if we still have some of the pre-reserved space */
3033 if (!ticket->t_cnt) {
3034 xlog_grant_add_space(log, &log->l_reserve_head.grant,
3035 ticket->t_unit_res);
3036 trace_xfs_log_ticket_regrant_exit(log, ticket);
3038 ticket->t_curr_res = ticket->t_unit_res;
3041 xfs_log_ticket_put(ticket);
3045 * Give back the space left from a reservation.
3047 * All the information we need to make a correct determination of space left
3048 * is present. For non-permanent reservations, things are quite easy. The
3049 * count should have been decremented to zero. We only need to deal with the
3050 * space remaining in the current reservation part of the ticket. If the
3051 * ticket contains a permanent reservation, there may be left over space which
3052 * needs to be released. A count of N means that N-1 refills of the current
3053 * reservation can be done before we need to ask for more space. The first
3054 * one goes to fill up the first current reservation. Once we run out of
3055 * space, the count will stay at zero and the only space remaining will be
3056 * in the current reservation field.
3059 xfs_log_ticket_ungrant(
3061 struct xlog_ticket *ticket)
3065 trace_xfs_log_ticket_ungrant(log, ticket);
3067 if (ticket->t_cnt > 0)
3070 trace_xfs_log_ticket_ungrant_sub(log, ticket);
3073 * If this is a permanent reservation ticket, we may be able to free
3074 * up more space based on the remaining count.
3076 bytes = ticket->t_curr_res;
3077 if (ticket->t_cnt > 0) {
3078 ASSERT(ticket->t_flags & XLOG_TIC_PERM_RESERV);
3079 bytes += ticket->t_unit_res*ticket->t_cnt;
3082 xlog_grant_sub_space(log, &log->l_reserve_head.grant, bytes);
3083 xlog_grant_sub_space(log, &log->l_write_head.grant, bytes);
3085 trace_xfs_log_ticket_ungrant_exit(log, ticket);
3087 xfs_log_space_wake(log->l_mp);
3088 xfs_log_ticket_put(ticket);
3092 * This routine will mark the current iclog in the ring as WANT_SYNC and move
3093 * the current iclog pointer to the next iclog in the ring.
3096 xlog_state_switch_iclogs(
3098 struct xlog_in_core *iclog,
3101 ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE);
3102 assert_spin_locked(&log->l_icloglock);
3103 trace_xlog_iclog_switch(iclog, _RET_IP_);
3106 eventual_size = iclog->ic_offset;
3107 iclog->ic_state = XLOG_STATE_WANT_SYNC;
3108 iclog->ic_header.h_prev_block = cpu_to_be32(log->l_prev_block);
3109 log->l_prev_block = log->l_curr_block;
3110 log->l_prev_cycle = log->l_curr_cycle;
3112 /* roll log?: ic_offset changed later */
3113 log->l_curr_block += BTOBB(eventual_size)+BTOBB(log->l_iclog_hsize);
3115 /* Round up to next log-sunit */
3116 if (log->l_iclog_roundoff > BBSIZE) {
3117 uint32_t sunit_bb = BTOBB(log->l_iclog_roundoff);
3118 log->l_curr_block = roundup(log->l_curr_block, sunit_bb);
3121 if (log->l_curr_block >= log->l_logBBsize) {
3123 * Rewind the current block before the cycle is bumped to make
3124 * sure that the combined LSN never transiently moves forward
3125 * when the log wraps to the next cycle. This is to support the
3126 * unlocked sample of these fields from xlog_valid_lsn(). Most
3127 * other cases should acquire l_icloglock.
3129 log->l_curr_block -= log->l_logBBsize;
3130 ASSERT(log->l_curr_block >= 0);
3132 log->l_curr_cycle++;
3133 if (log->l_curr_cycle == XLOG_HEADER_MAGIC_NUM)
3134 log->l_curr_cycle++;
3136 ASSERT(iclog == log->l_iclog);
3137 log->l_iclog = iclog->ic_next;
3141 * Force the iclog to disk and check if the iclog has been completed before
3142 * xlog_force_iclog() returns. This can happen on synchronous (e.g.
3143 * pmem) or fast async storage because we drop the icloglock to issue the IO.
3144 * If completion has already occurred, tell the caller so that it can avoid an
3145 * unnecessary wait on the iclog.
3148 xlog_force_and_check_iclog(
3149 struct xlog_in_core *iclog,
3152 xfs_lsn_t lsn = be64_to_cpu(iclog->ic_header.h_lsn);
3156 error = xlog_force_iclog(iclog);
3161 * If the iclog has already been completed and reused the header LSN
3162 * will have been rewritten by completion
3164 if (be64_to_cpu(iclog->ic_header.h_lsn) != lsn)
3170 * Write out all data in the in-core log as of this exact moment in time.
3172 * Data may be written to the in-core log during this call. However,
3173 * we don't guarantee this data will be written out. A change from past
3174 * implementation means this routine will *not* write out zero length LRs.
3176 * Basically, we try and perform an intelligent scan of the in-core logs.
3177 * If we determine there is no flushable data, we just return. There is no
3178 * flushable data if:
3180 * 1. the current iclog is active and has no data; the previous iclog
3181 * is in the active or dirty state.
3182 * 2. the current iclog is drity, and the previous iclog is in the
3183 * active or dirty state.
3187 * 1. the current iclog is not in the active nor dirty state.
3188 * 2. the current iclog dirty, and the previous iclog is not in the
3189 * active nor dirty state.
3190 * 3. the current iclog is active, and there is another thread writing
3191 * to this particular iclog.
3192 * 4. a) the current iclog is active and has no other writers
3193 * b) when we return from flushing out this iclog, it is still
3194 * not in the active nor dirty state.
3198 struct xfs_mount *mp,
3201 struct xlog *log = mp->m_log;
3202 struct xlog_in_core *iclog;
3204 XFS_STATS_INC(mp, xs_log_force);
3205 trace_xfs_log_force(mp, 0, _RET_IP_);
3207 xlog_cil_force(log);
3209 spin_lock(&log->l_icloglock);
3210 if (xlog_is_shutdown(log))
3213 iclog = log->l_iclog;
3214 trace_xlog_iclog_force(iclog, _RET_IP_);
3216 if (iclog->ic_state == XLOG_STATE_DIRTY ||
3217 (iclog->ic_state == XLOG_STATE_ACTIVE &&
3218 atomic_read(&iclog->ic_refcnt) == 0 && iclog->ic_offset == 0)) {
3220 * If the head is dirty or (active and empty), then we need to
3221 * look at the previous iclog.
3223 * If the previous iclog is active or dirty we are done. There
3224 * is nothing to sync out. Otherwise, we attach ourselves to the
3225 * previous iclog and go to sleep.
3227 iclog = iclog->ic_prev;
3228 } else if (iclog->ic_state == XLOG_STATE_ACTIVE) {
3229 if (atomic_read(&iclog->ic_refcnt) == 0) {
3230 /* We have exclusive access to this iclog. */
3233 if (xlog_force_and_check_iclog(iclog, &completed))
3240 * Someone else is still writing to this iclog, so we
3241 * need to ensure that when they release the iclog it
3242 * gets synced immediately as we may be waiting on it.
3244 xlog_state_switch_iclogs(log, iclog, 0);
3249 * The iclog we are about to wait on may contain the checkpoint pushed
3250 * by the above xlog_cil_force() call, but it may not have been pushed
3251 * to disk yet. Like the ACTIVE case above, we need to make sure caches
3252 * are flushed when this iclog is written.
3254 if (iclog->ic_state == XLOG_STATE_WANT_SYNC)
3255 iclog->ic_flags |= XLOG_ICL_NEED_FLUSH | XLOG_ICL_NEED_FUA;
3257 if (flags & XFS_LOG_SYNC)
3258 return xlog_wait_on_iclog(iclog);
3260 spin_unlock(&log->l_icloglock);
3263 spin_unlock(&log->l_icloglock);
3268 * Force the log to a specific LSN.
3270 * If an iclog with that lsn can be found:
3271 * If it is in the DIRTY state, just return.
3272 * If it is in the ACTIVE state, move the in-core log into the WANT_SYNC
3273 * state and go to sleep or return.
3274 * If it is in any other state, go to sleep or return.
3276 * Synchronous forces are implemented with a wait queue. All callers trying
3277 * to force a given lsn to disk must wait on the queue attached to the
3278 * specific in-core log. When given in-core log finally completes its write
3279 * to disk, that thread will wake up all threads waiting on the queue.
3289 struct xlog_in_core *iclog;
3292 spin_lock(&log->l_icloglock);
3293 if (xlog_is_shutdown(log))
3296 iclog = log->l_iclog;
3297 while (be64_to_cpu(iclog->ic_header.h_lsn) != lsn) {
3298 trace_xlog_iclog_force_lsn(iclog, _RET_IP_);
3299 iclog = iclog->ic_next;
3300 if (iclog == log->l_iclog)
3304 switch (iclog->ic_state) {
3305 case XLOG_STATE_ACTIVE:
3307 * We sleep here if we haven't already slept (e.g. this is the
3308 * first time we've looked at the correct iclog buf) and the
3309 * buffer before us is going to be sync'ed. The reason for this
3310 * is that if we are doing sync transactions here, by waiting
3311 * for the previous I/O to complete, we can allow a few more
3312 * transactions into this iclog before we close it down.
3314 * Otherwise, we mark the buffer WANT_SYNC, and bump up the
3315 * refcnt so we can release the log (which drops the ref count).
3316 * The state switch keeps new transaction commits from using
3317 * this buffer. When the current commits finish writing into
3318 * the buffer, the refcount will drop to zero and the buffer
3321 if (!already_slept &&
3322 (iclog->ic_prev->ic_state == XLOG_STATE_WANT_SYNC ||
3323 iclog->ic_prev->ic_state == XLOG_STATE_SYNCING)) {
3324 xlog_wait(&iclog->ic_prev->ic_write_wait,
3328 if (xlog_force_and_check_iclog(iclog, &completed))
3335 case XLOG_STATE_WANT_SYNC:
3337 * This iclog may contain the checkpoint pushed by the
3338 * xlog_cil_force_seq() call, but there are other writers still
3339 * accessing it so it hasn't been pushed to disk yet. Like the
3340 * ACTIVE case above, we need to make sure caches are flushed
3341 * when this iclog is written.
3343 iclog->ic_flags |= XLOG_ICL_NEED_FLUSH | XLOG_ICL_NEED_FUA;
3347 * The entire checkpoint was written by the CIL force and is on
3348 * its way to disk already. It will be stable when it
3349 * completes, so we don't need to manipulate caches here at all.
3350 * We just need to wait for completion if necessary.
3355 if (flags & XFS_LOG_SYNC)
3356 return xlog_wait_on_iclog(iclog);
3358 spin_unlock(&log->l_icloglock);
3361 spin_unlock(&log->l_icloglock);
3366 * Force the log to a specific checkpoint sequence.
3368 * First force the CIL so that all the required changes have been flushed to the
3369 * iclogs. If the CIL force completed it will return a commit LSN that indicates
3370 * the iclog that needs to be flushed to stable storage. If the caller needs
3371 * a synchronous log force, we will wait on the iclog with the LSN returned by
3372 * xlog_cil_force_seq() to be completed.
3376 struct xfs_mount *mp,
3381 struct xlog *log = mp->m_log;
3386 XFS_STATS_INC(mp, xs_log_force);
3387 trace_xfs_log_force(mp, seq, _RET_IP_);
3389 lsn = xlog_cil_force_seq(log, seq);
3390 if (lsn == NULLCOMMITLSN)
3393 ret = xlog_force_lsn(log, lsn, flags, log_flushed, false);
3394 if (ret == -EAGAIN) {
3395 XFS_STATS_INC(mp, xs_log_force_sleep);
3396 ret = xlog_force_lsn(log, lsn, flags, log_flushed, true);
3402 * Free a used ticket when its refcount falls to zero.
3406 xlog_ticket_t *ticket)
3408 ASSERT(atomic_read(&ticket->t_ref) > 0);
3409 if (atomic_dec_and_test(&ticket->t_ref))
3410 kmem_cache_free(xfs_log_ticket_cache, ticket);
3415 xlog_ticket_t *ticket)
3417 ASSERT(atomic_read(&ticket->t_ref) > 0);
3418 atomic_inc(&ticket->t_ref);
3423 * Figure out the total log space unit (in bytes) that would be
3424 * required for a log ticket.
3436 * Permanent reservations have up to 'cnt'-1 active log operations
3437 * in the log. A unit in this case is the amount of space for one
3438 * of these log operations. Normal reservations have a cnt of 1
3439 * and their unit amount is the total amount of space required.
3441 * The following lines of code account for non-transaction data
3442 * which occupy space in the on-disk log.
3444 * Normal form of a transaction is:
3445 * <oph><trans-hdr><start-oph><reg1-oph><reg1><reg2-oph>...<commit-oph>
3446 * and then there are LR hdrs, split-recs and roundoff at end of syncs.
3448 * We need to account for all the leadup data and trailer data
3449 * around the transaction data.
3450 * And then we need to account for the worst case in terms of using
3452 * The worst case will happen if:
3453 * - the placement of the transaction happens to be such that the
3454 * roundoff is at its maximum
3455 * - the transaction data is synced before the commit record is synced
3456 * i.e. <transaction-data><roundoff> | <commit-rec><roundoff>
3457 * Therefore the commit record is in its own Log Record.
3458 * This can happen as the commit record is called with its
3459 * own region to xlog_write().
3460 * This then means that in the worst case, roundoff can happen for
3461 * the commit-rec as well.
3462 * The commit-rec is smaller than padding in this scenario and so it is
3463 * not added separately.
3466 /* for trans header */
3467 unit_bytes += sizeof(xlog_op_header_t);
3468 unit_bytes += sizeof(xfs_trans_header_t);
3471 unit_bytes += sizeof(xlog_op_header_t);
3474 * for LR headers - the space for data in an iclog is the size minus
3475 * the space used for the headers. If we use the iclog size, then we
3476 * undercalculate the number of headers required.
3478 * Furthermore - the addition of op headers for split-recs might
3479 * increase the space required enough to require more log and op
3480 * headers, so take that into account too.
3482 * IMPORTANT: This reservation makes the assumption that if this
3483 * transaction is the first in an iclog and hence has the LR headers
3484 * accounted to it, then the remaining space in the iclog is
3485 * exclusively for this transaction. i.e. if the transaction is larger
3486 * than the iclog, it will be the only thing in that iclog.
3487 * Fundamentally, this means we must pass the entire log vector to
3488 * xlog_write to guarantee this.
3490 iclog_space = log->l_iclog_size - log->l_iclog_hsize;
3491 num_headers = howmany(unit_bytes, iclog_space);
3493 /* for split-recs - ophdrs added when data split over LRs */
3494 unit_bytes += sizeof(xlog_op_header_t) * num_headers;
3496 /* add extra header reservations if we overrun */
3497 while (!num_headers ||
3498 howmany(unit_bytes, iclog_space) > num_headers) {
3499 unit_bytes += sizeof(xlog_op_header_t);
3502 unit_bytes += log->l_iclog_hsize * num_headers;
3504 /* for commit-rec LR header - note: padding will subsume the ophdr */
3505 unit_bytes += log->l_iclog_hsize;
3507 /* roundoff padding for transaction data and one for commit record */
3508 unit_bytes += 2 * log->l_iclog_roundoff;
3511 *niclogs = num_headers;
3516 xfs_log_calc_unit_res(
3517 struct xfs_mount *mp,
3520 return xlog_calc_unit_res(mp->m_log, unit_bytes, NULL);
3524 * Allocate and initialise a new log ticket.
3526 struct xlog_ticket *
3533 struct xlog_ticket *tic;
3536 tic = kmem_cache_zalloc(xfs_log_ticket_cache, GFP_NOFS | __GFP_NOFAIL);
3538 unit_res = xlog_calc_unit_res(log, unit_bytes, &tic->t_iclog_hdrs);
3540 atomic_set(&tic->t_ref, 1);
3541 tic->t_task = current;
3542 INIT_LIST_HEAD(&tic->t_queue);
3543 tic->t_unit_res = unit_res;
3544 tic->t_curr_res = unit_res;
3547 tic->t_tid = get_random_u32();
3549 tic->t_flags |= XLOG_TIC_PERM_RESERV;
3556 * Check to make sure the grant write head didn't just over lap the tail. If
3557 * the cycles are the same, we can't be overlapping. Otherwise, make sure that
3558 * the cycles differ by exactly one and check the byte count.
3560 * This check is run unlocked, so can give false positives. Rather than assert
3561 * on failures, use a warn-once flag and a panic tag to allow the admin to
3562 * determine if they want to panic the machine when such an error occurs. For
3563 * debug kernels this will have the same effect as using an assert but, unlinke
3564 * an assert, it can be turned off at runtime.
3567 xlog_verify_grant_tail(
3570 int tail_cycle, tail_blocks;
3573 xlog_crack_grant_head(&log->l_write_head.grant, &cycle, &space);
3574 xlog_crack_atomic_lsn(&log->l_tail_lsn, &tail_cycle, &tail_blocks);
3575 if (tail_cycle != cycle) {
3576 if (cycle - 1 != tail_cycle &&
3577 !test_and_set_bit(XLOG_TAIL_WARN, &log->l_opstate)) {
3578 xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES,
3579 "%s: cycle - 1 != tail_cycle", __func__);
3582 if (space > BBTOB(tail_blocks) &&
3583 !test_and_set_bit(XLOG_TAIL_WARN, &log->l_opstate)) {
3584 xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES,
3585 "%s: space > BBTOB(tail_blocks)", __func__);
3590 /* check if it will fit */
3592 xlog_verify_tail_lsn(
3594 struct xlog_in_core *iclog)
3596 xfs_lsn_t tail_lsn = be64_to_cpu(iclog->ic_header.h_tail_lsn);
3599 if (CYCLE_LSN(tail_lsn) == log->l_prev_cycle) {
3601 log->l_logBBsize - (log->l_prev_block - BLOCK_LSN(tail_lsn));
3602 if (blocks < BTOBB(iclog->ic_offset)+BTOBB(log->l_iclog_hsize))
3603 xfs_emerg(log->l_mp, "%s: ran out of log space", __func__);
3605 ASSERT(CYCLE_LSN(tail_lsn)+1 == log->l_prev_cycle);
3607 if (BLOCK_LSN(tail_lsn) == log->l_prev_block)
3608 xfs_emerg(log->l_mp, "%s: tail wrapped", __func__);
3610 blocks = BLOCK_LSN(tail_lsn) - log->l_prev_block;
3611 if (blocks < BTOBB(iclog->ic_offset) + 1)
3612 xfs_emerg(log->l_mp, "%s: ran out of log space", __func__);
3617 * Perform a number of checks on the iclog before writing to disk.
3619 * 1. Make sure the iclogs are still circular
3620 * 2. Make sure we have a good magic number
3621 * 3. Make sure we don't have magic numbers in the data
3622 * 4. Check fields of each log operation header for:
3623 * A. Valid client identifier
3624 * B. tid ptr value falls in valid ptr space (user space code)
3625 * C. Length in log record header is correct according to the
3626 * individual operation headers within record.
3627 * 5. When a bwrite will occur within 5 blocks of the front of the physical
3628 * log, check the preceding blocks of the physical log to make sure all
3629 * the cycle numbers agree with the current cycle number.
3634 struct xlog_in_core *iclog,
3637 xlog_op_header_t *ophead;
3638 xlog_in_core_t *icptr;
3639 xlog_in_core_2_t *xhdr;
3640 void *base_ptr, *ptr, *p;
3641 ptrdiff_t field_offset;
3643 int len, i, j, k, op_len;
3646 /* check validity of iclog pointers */
3647 spin_lock(&log->l_icloglock);
3648 icptr = log->l_iclog;
3649 for (i = 0; i < log->l_iclog_bufs; i++, icptr = icptr->ic_next)
3652 if (icptr != log->l_iclog)
3653 xfs_emerg(log->l_mp, "%s: corrupt iclog ring", __func__);
3654 spin_unlock(&log->l_icloglock);
3656 /* check log magic numbers */
3657 if (iclog->ic_header.h_magicno != cpu_to_be32(XLOG_HEADER_MAGIC_NUM))
3658 xfs_emerg(log->l_mp, "%s: invalid magic num", __func__);
3660 base_ptr = ptr = &iclog->ic_header;
3661 p = &iclog->ic_header;
3662 for (ptr += BBSIZE; ptr < base_ptr + count; ptr += BBSIZE) {
3663 if (*(__be32 *)ptr == cpu_to_be32(XLOG_HEADER_MAGIC_NUM))
3664 xfs_emerg(log->l_mp, "%s: unexpected magic num",
3669 len = be32_to_cpu(iclog->ic_header.h_num_logops);
3670 base_ptr = ptr = iclog->ic_datap;
3672 xhdr = iclog->ic_data;
3673 for (i = 0; i < len; i++) {
3676 /* clientid is only 1 byte */
3677 p = &ophead->oh_clientid;
3678 field_offset = p - base_ptr;
3679 if (field_offset & 0x1ff) {
3680 clientid = ophead->oh_clientid;
3682 idx = BTOBBT((void *)&ophead->oh_clientid - iclog->ic_datap);
3683 if (idx >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE)) {
3684 j = idx / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3685 k = idx % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3686 clientid = xlog_get_client_id(
3687 xhdr[j].hic_xheader.xh_cycle_data[k]);
3689 clientid = xlog_get_client_id(
3690 iclog->ic_header.h_cycle_data[idx]);
3693 if (clientid != XFS_TRANSACTION && clientid != XFS_LOG) {
3695 "%s: op %d invalid clientid %d op "PTR_FMT" offset 0x%lx",
3696 __func__, i, clientid, ophead,
3697 (unsigned long)field_offset);
3701 p = &ophead->oh_len;
3702 field_offset = p - base_ptr;
3703 if (field_offset & 0x1ff) {
3704 op_len = be32_to_cpu(ophead->oh_len);
3706 idx = BTOBBT((void *)&ophead->oh_len - iclog->ic_datap);
3707 if (idx >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE)) {
3708 j = idx / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3709 k = idx % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3710 op_len = be32_to_cpu(xhdr[j].hic_xheader.xh_cycle_data[k]);
3712 op_len = be32_to_cpu(iclog->ic_header.h_cycle_data[idx]);
3715 ptr += sizeof(xlog_op_header_t) + op_len;
3721 * Perform a forced shutdown on the log.
3723 * This can be called from low level log code to trigger a shutdown, or from the
3724 * high level mount shutdown code when the mount shuts down.
3726 * Our main objectives here are to make sure that:
3727 * a. if the shutdown was not due to a log IO error, flush the logs to
3728 * disk. Anything modified after this is ignored.
3729 * b. the log gets atomically marked 'XLOG_IO_ERROR' for all interested
3730 * parties to find out. Nothing new gets queued after this is done.
3731 * c. Tasks sleeping on log reservations, pinned objects and
3732 * other resources get woken up.
3733 * d. The mount is also marked as shut down so that log triggered shutdowns
3734 * still behave the same as if they called xfs_forced_shutdown().
3736 * Return true if the shutdown cause was a log IO error and we actually shut the
3740 xlog_force_shutdown(
3742 uint32_t shutdown_flags)
3744 bool log_error = (shutdown_flags & SHUTDOWN_LOG_IO_ERROR);
3750 * Flush all the completed transactions to disk before marking the log
3751 * being shut down. We need to do this first as shutting down the log
3752 * before the force will prevent the log force from flushing the iclogs
3755 * When we are in recovery, there are no transactions to flush, and
3756 * we don't want to touch the log because we don't want to perturb the
3757 * current head/tail for future recovery attempts. Hence we need to
3758 * avoid a log force in this case.
3760 * If we are shutting down due to a log IO error, then we must avoid
3761 * trying to write the log as that may just result in more IO errors and
3762 * an endless shutdown/force loop.
3764 if (!log_error && !xlog_in_recovery(log))
3765 xfs_log_force(log->l_mp, XFS_LOG_SYNC);
3768 * Atomically set the shutdown state. If the shutdown state is already
3769 * set, there someone else is performing the shutdown and so we are done
3770 * here. This should never happen because we should only ever get called
3771 * once by the first shutdown caller.
3773 * Much of the log state machine transitions assume that shutdown state
3774 * cannot change once they hold the log->l_icloglock. Hence we need to
3775 * hold that lock here, even though we use the atomic test_and_set_bit()
3776 * operation to set the shutdown state.
3778 spin_lock(&log->l_icloglock);
3779 if (test_and_set_bit(XLOG_IO_ERROR, &log->l_opstate)) {
3780 spin_unlock(&log->l_icloglock);
3783 spin_unlock(&log->l_icloglock);
3786 * If this log shutdown also sets the mount shutdown state, issue a
3787 * shutdown warning message.
3789 if (!test_and_set_bit(XFS_OPSTATE_SHUTDOWN, &log->l_mp->m_opstate)) {
3790 xfs_alert_tag(log->l_mp, XFS_PTAG_SHUTDOWN_LOGERROR,
3791 "Filesystem has been shut down due to log error (0x%x).",
3793 xfs_alert(log->l_mp,
3794 "Please unmount the filesystem and rectify the problem(s).");
3795 if (xfs_error_level >= XFS_ERRLEVEL_HIGH)
3800 * We don't want anybody waiting for log reservations after this. That
3801 * means we have to wake up everybody queued up on reserveq as well as
3802 * writeq. In addition, we make sure in xlog_{re}grant_log_space that
3803 * we don't enqueue anything once the SHUTDOWN flag is set, and this
3804 * action is protected by the grant locks.
3806 xlog_grant_head_wake_all(&log->l_reserve_head);
3807 xlog_grant_head_wake_all(&log->l_write_head);
3810 * Wake up everybody waiting on xfs_log_force. Wake the CIL push first
3811 * as if the log writes were completed. The abort handling in the log
3812 * item committed callback functions will do this again under lock to
3815 spin_lock(&log->l_cilp->xc_push_lock);
3816 wake_up_all(&log->l_cilp->xc_start_wait);
3817 wake_up_all(&log->l_cilp->xc_commit_wait);
3818 spin_unlock(&log->l_cilp->xc_push_lock);
3820 spin_lock(&log->l_icloglock);
3821 xlog_state_shutdown_callbacks(log);
3822 spin_unlock(&log->l_icloglock);
3824 wake_up_var(&log->l_opstate);
3832 xlog_in_core_t *iclog;
3834 iclog = log->l_iclog;
3836 /* endianness does not matter here, zero is zero in
3839 if (iclog->ic_header.h_num_logops)
3841 iclog = iclog->ic_next;
3842 } while (iclog != log->l_iclog);
3847 * Verify that an LSN stamped into a piece of metadata is valid. This is
3848 * intended for use in read verifiers on v5 superblocks.
3852 struct xfs_mount *mp,
3855 struct xlog *log = mp->m_log;
3859 * norecovery mode skips mount-time log processing and unconditionally
3860 * resets the in-core LSN. We can't validate in this mode, but
3861 * modifications are not allowed anyways so just return true.
3863 if (xfs_has_norecovery(mp))
3867 * Some metadata LSNs are initialized to NULL (e.g., the agfl). This is
3868 * handled by recovery and thus safe to ignore here.
3870 if (lsn == NULLCOMMITLSN)
3873 valid = xlog_valid_lsn(mp->m_log, lsn);
3875 /* warn the user about what's gone wrong before verifier failure */
3877 spin_lock(&log->l_icloglock);
3879 "Corruption warning: Metadata has LSN (%d:%d) ahead of current LSN (%d:%d). "
3880 "Please unmount and run xfs_repair (>= v4.3) to resolve.",
3881 CYCLE_LSN(lsn), BLOCK_LSN(lsn),
3882 log->l_curr_cycle, log->l_curr_block);
3883 spin_unlock(&log->l_icloglock);
3890 * Notify the log that we're about to start using a feature that is protected
3891 * by a log incompat feature flag. This will prevent log covering from
3892 * clearing those flags.
3895 xlog_use_incompat_feat(
3898 down_read(&log->l_incompat_users);
3901 /* Notify the log that we've finished using log incompat features. */
3903 xlog_drop_incompat_feat(
3906 up_read(&log->l_incompat_users);