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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
4 * All Rights Reserved.
5 */
6#include "xfs.h"
7#include "xfs_fs.h"
8#include "xfs_shared.h"
9#include "xfs_format.h"
10#include "xfs_log_format.h"
11#include "xfs_trans_resv.h"
12#include "xfs_mount.h"
13#include "xfs_errortag.h"
14#include "xfs_error.h"
15#include "xfs_trans.h"
16#include "xfs_trans_priv.h"
17#include "xfs_log.h"
18#include "xfs_log_priv.h"
19#include "xfs_trace.h"
20#include "xfs_sysfs.h"
21#include "xfs_sb.h"
22#include "xfs_health.h"
23
24struct kmem_cache *xfs_log_ticket_cache;
25
26/* Local miscellaneous function prototypes */
27STATIC struct xlog *
28xlog_alloc_log(
29 struct xfs_mount *mp,
30 struct xfs_buftarg *log_target,
31 xfs_daddr_t blk_offset,
32 int num_bblks);
33STATIC int
34xlog_space_left(
35 struct xlog *log,
36 atomic64_t *head);
37STATIC void
38xlog_dealloc_log(
39 struct xlog *log);
40
41/* local state machine functions */
42STATIC void xlog_state_done_syncing(
43 struct xlog_in_core *iclog);
44STATIC void xlog_state_do_callback(
45 struct xlog *log);
46STATIC int
47xlog_state_get_iclog_space(
48 struct xlog *log,
49 int len,
50 struct xlog_in_core **iclog,
51 struct xlog_ticket *ticket,
52 int *logoffsetp);
53STATIC void
54xlog_grant_push_ail(
55 struct xlog *log,
56 int need_bytes);
57STATIC void
58xlog_sync(
59 struct xlog *log,
60 struct xlog_in_core *iclog,
61 struct xlog_ticket *ticket);
62#if defined(DEBUG)
63STATIC void
64xlog_verify_grant_tail(
65 struct xlog *log);
66STATIC void
67xlog_verify_iclog(
68 struct xlog *log,
69 struct xlog_in_core *iclog,
70 int count);
71STATIC void
72xlog_verify_tail_lsn(
73 struct xlog *log,
74 struct xlog_in_core *iclog);
75#else
76#define xlog_verify_grant_tail(a)
77#define xlog_verify_iclog(a,b,c)
78#define xlog_verify_tail_lsn(a,b)
79#endif
80
81STATIC int
82xlog_iclogs_empty(
83 struct xlog *log);
84
85static int
86xfs_log_cover(struct xfs_mount *);
87
88/*
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.
92 *
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
96 * CIL context ticket.
97 *
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.
104 */
105void *
106xlog_prepare_iovec(
107 struct xfs_log_vec *lv,
108 struct xfs_log_iovec **vecp,
109 uint type)
110{
111 struct xfs_log_iovec *vec = *vecp;
112 struct xlog_op_header *oph;
113 uint32_t len;
114 void *buf;
115
116 if (vec) {
117 ASSERT(vec - lv->lv_iovecp < lv->lv_niovecs);
118 vec++;
119 } else {
120 vec = &lv->lv_iovecp[0];
121 }
122
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);
127 }
128
129 vec->i_type = type;
130 vec->i_addr = lv->lv_buf + lv->lv_buf_len;
131
132 oph = vec->i_addr;
133 oph->oh_clientid = XFS_TRANSACTION;
134 oph->oh_res2 = 0;
135 oph->oh_flags = 0;
136
137 buf = vec->i_addr + sizeof(struct xlog_op_header);
138 ASSERT(IS_ALIGNED((unsigned long)buf, sizeof(uint64_t)));
139
140 *vecp = vec;
141 return buf;
142}
143
144static void
145xlog_grant_sub_space(
146 struct xlog *log,
147 atomic64_t *head,
148 int bytes)
149{
150 int64_t head_val = atomic64_read(head);
151 int64_t new, old;
152
153 do {
154 int cycle, space;
155
156 xlog_crack_grant_head_val(head_val, &cycle, &space);
157
158 space -= bytes;
159 if (space < 0) {
160 space += log->l_logsize;
161 cycle--;
162 }
163
164 old = head_val;
165 new = xlog_assign_grant_head_val(cycle, space);
166 head_val = atomic64_cmpxchg(head, old, new);
167 } while (head_val != old);
168}
169
170static void
171xlog_grant_add_space(
172 struct xlog *log,
173 atomic64_t *head,
174 int bytes)
175{
176 int64_t head_val = atomic64_read(head);
177 int64_t new, old;
178
179 do {
180 int tmp;
181 int cycle, space;
182
183 xlog_crack_grant_head_val(head_val, &cycle, &space);
184
185 tmp = log->l_logsize - space;
186 if (tmp > bytes)
187 space += bytes;
188 else {
189 space = bytes - tmp;
190 cycle++;
191 }
192
193 old = head_val;
194 new = xlog_assign_grant_head_val(cycle, space);
195 head_val = atomic64_cmpxchg(head, old, new);
196 } while (head_val != old);
197}
198
199STATIC void
200xlog_grant_head_init(
201 struct xlog_grant_head *head)
202{
203 xlog_assign_grant_head(&head->grant, 1, 0);
204 INIT_LIST_HEAD(&head->waiters);
205 spin_lock_init(&head->lock);
206}
207
208STATIC void
209xlog_grant_head_wake_all(
210 struct xlog_grant_head *head)
211{
212 struct xlog_ticket *tic;
213
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);
218}
219
220static inline int
221xlog_ticket_reservation(
222 struct xlog *log,
223 struct xlog_grant_head *head,
224 struct xlog_ticket *tic)
225{
226 if (head == &log->l_write_head) {
227 ASSERT(tic->t_flags & XLOG_TIC_PERM_RESERV);
228 return tic->t_unit_res;
229 }
230
231 if (tic->t_flags & XLOG_TIC_PERM_RESERV)
232 return tic->t_unit_res * tic->t_cnt;
233
234 return tic->t_unit_res;
235}
236
237STATIC bool
238xlog_grant_head_wake(
239 struct xlog *log,
240 struct xlog_grant_head *head,
241 int *free_bytes)
242{
243 struct xlog_ticket *tic;
244 int need_bytes;
245 bool woken_task = false;
246
247 list_for_each_entry(tic, &head->waiters, t_queue) {
248
249 /*
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.
255 *
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
262 * push target.
263 *
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.
268 */
269
270 need_bytes = xlog_ticket_reservation(log, head, tic);
271 if (*free_bytes < need_bytes) {
272 if (!woken_task)
273 xlog_grant_push_ail(log, need_bytes);
274 return false;
275 }
276
277 *free_bytes -= need_bytes;
278 trace_xfs_log_grant_wake_up(log, tic);
279 wake_up_process(tic->t_task);
280 woken_task = true;
281 }
282
283 return true;
284}
285
286STATIC int
287xlog_grant_head_wait(
288 struct xlog *log,
289 struct xlog_grant_head *head,
290 struct xlog_ticket *tic,
291 int need_bytes) __releases(&head->lock)
292 __acquires(&head->lock)
293{
294 list_add_tail(&tic->t_queue, &head->waiters);
295
296 do {
297 if (xlog_is_shutdown(log))
298 goto shutdown;
299 xlog_grant_push_ail(log, need_bytes);
300
301 __set_current_state(TASK_UNINTERRUPTIBLE);
302 spin_unlock(&head->lock);
303
304 XFS_STATS_INC(log->l_mp, xs_sleep_logspace);
305
306 trace_xfs_log_grant_sleep(log, tic);
307 schedule();
308 trace_xfs_log_grant_wake(log, tic);
309
310 spin_lock(&head->lock);
311 if (xlog_is_shutdown(log))
312 goto shutdown;
313 } while (xlog_space_left(log, &head->grant) < need_bytes);
314
315 list_del_init(&tic->t_queue);
316 return 0;
317shutdown:
318 list_del_init(&tic->t_queue);
319 return -EIO;
320}
321
322/*
323 * Atomically get the log space required for a log ticket.
324 *
325 * Once a ticket gets put onto head->waiters, it will only return after the
326 * needed reservation is satisfied.
327 *
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
331 * every pass.
332 *
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.
338 */
339STATIC int
340xlog_grant_head_check(
341 struct xlog *log,
342 struct xlog_grant_head *head,
343 struct xlog_ticket *tic,
344 int *need_bytes)
345{
346 int free_bytes;
347 int error = 0;
348
349 ASSERT(!xlog_in_recovery(log));
350
351 /*
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.
356 */
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,
364 *need_bytes);
365 }
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);
371 }
372
373 return error;
374}
375
376bool
377xfs_log_writable(
378 struct xfs_mount *mp)
379{
380 /*
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.
385 */
386 if (xfs_has_norecovery(mp))
387 return false;
388 if (xfs_readonly_buftarg(mp->m_ddev_targp))
389 return false;
390 if (xfs_readonly_buftarg(mp->m_log->l_targ))
391 return false;
392 if (xlog_is_shutdown(mp->m_log))
393 return false;
394 return true;
395}
396
397/*
398 * Replenish the byte reservation required by moving the grant write head.
399 */
400int
401xfs_log_regrant(
402 struct xfs_mount *mp,
403 struct xlog_ticket *tic)
404{
405 struct xlog *log = mp->m_log;
406 int need_bytes;
407 int error = 0;
408
409 if (xlog_is_shutdown(log))
410 return -EIO;
411
412 XFS_STATS_INC(mp, xs_try_logspace);
413
414 /*
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.
419 */
420 tic->t_tid++;
421
422 xlog_grant_push_ail(log, tic->t_unit_res);
423
424 tic->t_curr_res = tic->t_unit_res;
425 if (tic->t_cnt > 0)
426 return 0;
427
428 trace_xfs_log_regrant(log, tic);
429
430 error = xlog_grant_head_check(log, &log->l_write_head, tic,
431 &need_bytes);
432 if (error)
433 goto out_error;
434
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);
438 return 0;
439
440out_error:
441 /*
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.
445 */
446 tic->t_curr_res = 0;
447 tic->t_cnt = 0; /* ungrant will give back unit_res * t_cnt. */
448 return error;
449}
450
451/*
452 * Reserve log space and return a ticket corresponding to the reservation.
453 *
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.
458 */
459int
460xfs_log_reserve(
461 struct xfs_mount *mp,
462 int unit_bytes,
463 int cnt,
464 struct xlog_ticket **ticp,
465 bool permanent)
466{
467 struct xlog *log = mp->m_log;
468 struct xlog_ticket *tic;
469 int need_bytes;
470 int error = 0;
471
472 if (xlog_is_shutdown(log))
473 return -EIO;
474
475 XFS_STATS_INC(mp, xs_try_logspace);
476
477 ASSERT(*ticp == NULL);
478 tic = xlog_ticket_alloc(log, unit_bytes, cnt, permanent);
479 *ticp = tic;
480
481 xlog_grant_push_ail(log, tic->t_cnt ? tic->t_unit_res * tic->t_cnt
482 : tic->t_unit_res);
483
484 trace_xfs_log_reserve(log, tic);
485
486 error = xlog_grant_head_check(log, &log->l_reserve_head, tic,
487 &need_bytes);
488 if (error)
489 goto out_error;
490
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);
495 return 0;
496
497out_error:
498 /*
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.
502 */
503 tic->t_curr_res = 0;
504 tic->t_cnt = 0; /* ungrant will give back unit_res * t_cnt. */
505 return error;
506}
507
508/*
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.
516 *
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.
521 */
522static void
523xlog_state_shutdown_callbacks(
524 struct xlog *log)
525{
526 struct xlog_in_core *iclog;
527 LIST_HEAD(cb_list);
528
529 iclog = log->l_iclog;
530 do {
531 if (atomic_read(&iclog->ic_refcnt)) {
532 /* Reference holder will re-run iclog callbacks. */
533 continue;
534 }
535 list_splice_init(&iclog->ic_callbacks, &cb_list);
536 spin_unlock(&log->l_icloglock);
537
538 xlog_cil_process_committed(&cb_list);
539
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);
544
545 wake_up_all(&log->l_flush_wait);
546}
547
548/*
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.
551 *
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.
559 *
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.
567 */
568int
569xlog_state_release_iclog(
570 struct xlog *log,
571 struct xlog_in_core *iclog,
572 struct xlog_ticket *ticket)
573{
574 xfs_lsn_t tail_lsn;
575 bool last_ref;
576
577 lockdep_assert_held(&log->l_icloglock);
578
579 trace_xlog_iclog_release(iclog, _RET_IP_);
580 /*
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.
585 */
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);
591 }
592
593 last_ref = atomic_dec_and_test(&iclog->ic_refcnt);
594
595 if (xlog_is_shutdown(log)) {
596 /*
597 * If there are no more references to this iclog, process the
598 * pending iclog callbacks that were waiting on the release of
599 * this iclog.
600 */
601 if (last_ref)
602 xlog_state_shutdown_callbacks(log);
603 return -EIO;
604 }
605
606 if (!last_ref)
607 return 0;
608
609 if (iclog->ic_state != XLOG_STATE_WANT_SYNC) {
610 ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE);
611 return 0;
612 }
613
614 iclog->ic_state = XLOG_STATE_SYNCING;
615 xlog_verify_tail_lsn(log, iclog);
616 trace_xlog_iclog_syncing(iclog, _RET_IP_);
617
618 spin_unlock(&log->l_icloglock);
619 xlog_sync(log, iclog, ticket);
620 spin_lock(&log->l_icloglock);
621 return 0;
622}
623
624/*
625 * Mount a log filesystem
626 *
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
631 *
632 * Return error or zero.
633 */
634int
635xfs_log_mount(
636 xfs_mount_t *mp,
637 xfs_buftarg_t *log_target,
638 xfs_daddr_t blk_offset,
639 int num_bblks)
640{
641 struct xlog *log;
642 int error = 0;
643 int min_logfsbs;
644
645 if (!xfs_has_norecovery(mp)) {
646 xfs_notice(mp, "Mounting V%d Filesystem %pU",
647 XFS_SB_VERSION_NUM(&mp->m_sb),
648 &mp->m_sb.sb_uuid);
649 } else {
650 xfs_notice(mp,
651"Mounting V%d filesystem %pU in no-recovery mode. Filesystem will be inconsistent.",
652 XFS_SB_VERSION_NUM(&mp->m_sb),
653 &mp->m_sb.sb_uuid);
654 ASSERT(xfs_is_readonly(mp));
655 }
656
657 log = xlog_alloc_log(mp, log_target, blk_offset, num_bblks);
658 if (IS_ERR(log)) {
659 error = PTR_ERR(log);
660 goto out;
661 }
662 mp->m_log = log;
663
664 /*
665 * Now that we have set up the log and it's internal geometry
666 * parameters, we can validate the given log space and drop a critical
667 * message via syslog if the log size is too small. A log that is too
668 * small can lead to unexpected situations in transaction log space
669 * reservation stage. The superblock verifier has already validated all
670 * the other log geometry constraints, so we don't have to check those
671 * here.
672 *
673 * Note: For v4 filesystems, we can't just reject the mount if the
674 * validation fails. This would mean that people would have to
675 * downgrade their kernel just to remedy the situation as there is no
676 * way to grow the log (short of black magic surgery with xfs_db).
677 *
678 * We can, however, reject mounts for V5 format filesystems, as the
679 * mkfs binary being used to make the filesystem should never create a
680 * filesystem with a log that is too small.
681 */
682 min_logfsbs = xfs_log_calc_minimum_size(mp);
683 if (mp->m_sb.sb_logblocks < min_logfsbs) {
684 xfs_warn(mp,
685 "Log size %d blocks too small, minimum size is %d blocks",
686 mp->m_sb.sb_logblocks, min_logfsbs);
687
688 /*
689 * Log check errors are always fatal on v5; or whenever bad
690 * metadata leads to a crash.
691 */
692 if (xfs_has_crc(mp)) {
693 xfs_crit(mp, "AAIEEE! Log failed size checks. Abort!");
694 ASSERT(0);
695 error = -EINVAL;
696 goto out_free_log;
697 }
698 xfs_crit(mp, "Log size out of supported range.");
699 xfs_crit(mp,
700"Continuing onwards, but if log hangs are experienced then please report this message in the bug report.");
701 }
702
703 /*
704 * Initialize the AIL now we have a log.
705 */
706 error = xfs_trans_ail_init(mp);
707 if (error) {
708 xfs_warn(mp, "AIL initialisation failed: error %d", error);
709 goto out_free_log;
710 }
711 log->l_ailp = mp->m_ail;
712
713 /*
714 * skip log recovery on a norecovery mount. pretend it all
715 * just worked.
716 */
717 if (!xfs_has_norecovery(mp)) {
718 error = xlog_recover(log);
719 if (error) {
720 xfs_warn(mp, "log mount/recovery failed: error %d",
721 error);
722 xlog_recover_cancel(log);
723 goto out_destroy_ail;
724 }
725 }
726
727 error = xfs_sysfs_init(&log->l_kobj, &xfs_log_ktype, &mp->m_kobj,
728 "log");
729 if (error)
730 goto out_destroy_ail;
731
732 /* Normal transactions can now occur */
733 clear_bit(XLOG_ACTIVE_RECOVERY, &log->l_opstate);
734
735 /*
736 * Now the log has been fully initialised and we know were our
737 * space grant counters are, we can initialise the permanent ticket
738 * needed for delayed logging to work.
739 */
740 xlog_cil_init_post_recovery(log);
741
742 return 0;
743
744out_destroy_ail:
745 xfs_trans_ail_destroy(mp);
746out_free_log:
747 xlog_dealloc_log(log);
748out:
749 return error;
750}
751
752/*
753 * Finish the recovery of the file system. This is separate from the
754 * xfs_log_mount() call, because it depends on the code in xfs_mountfs() to read
755 * in the root and real-time bitmap inodes between calling xfs_log_mount() and
756 * here.
757 *
758 * If we finish recovery successfully, start the background log work. If we are
759 * not doing recovery, then we have a RO filesystem and we don't need to start
760 * it.
761 */
762int
763xfs_log_mount_finish(
764 struct xfs_mount *mp)
765{
766 struct xlog *log = mp->m_log;
767 int error = 0;
768
769 if (xfs_has_norecovery(mp)) {
770 ASSERT(xfs_is_readonly(mp));
771 return 0;
772 }
773
774 /*
775 * During the second phase of log recovery, we need iget and
776 * iput to behave like they do for an active filesystem.
777 * xfs_fs_drop_inode needs to be able to prevent the deletion
778 * of inodes before we're done replaying log items on those
779 * inodes. Turn it off immediately after recovery finishes
780 * so that we don't leak the quota inodes if subsequent mount
781 * activities fail.
782 *
783 * We let all inodes involved in redo item processing end up on
784 * the LRU instead of being evicted immediately so that if we do
785 * something to an unlinked inode, the irele won't cause
786 * premature truncation and freeing of the inode, which results
787 * in log recovery failure. We have to evict the unreferenced
788 * lru inodes after clearing SB_ACTIVE because we don't
789 * otherwise clean up the lru if there's a subsequent failure in
790 * xfs_mountfs, which leads to us leaking the inodes if nothing
791 * else (e.g. quotacheck) references the inodes before the
792 * mount failure occurs.
793 */
794 mp->m_super->s_flags |= SB_ACTIVE;
795 xfs_log_work_queue(mp);
796 if (xlog_recovery_needed(log))
797 error = xlog_recover_finish(log);
798 mp->m_super->s_flags &= ~SB_ACTIVE;
799 evict_inodes(mp->m_super);
800
801 /*
802 * Drain the buffer LRU after log recovery. This is required for v4
803 * filesystems to avoid leaving around buffers with NULL verifier ops,
804 * but we do it unconditionally to make sure we're always in a clean
805 * cache state after mount.
806 *
807 * Don't push in the error case because the AIL may have pending intents
808 * that aren't removed until recovery is cancelled.
809 */
810 if (xlog_recovery_needed(log)) {
811 if (!error) {
812 xfs_log_force(mp, XFS_LOG_SYNC);
813 xfs_ail_push_all_sync(mp->m_ail);
814 }
815 xfs_notice(mp, "Ending recovery (logdev: %s)",
816 mp->m_logname ? mp->m_logname : "internal");
817 } else {
818 xfs_info(mp, "Ending clean mount");
819 }
820 xfs_buftarg_drain(mp->m_ddev_targp);
821
822 clear_bit(XLOG_RECOVERY_NEEDED, &log->l_opstate);
823
824 /* Make sure the log is dead if we're returning failure. */
825 ASSERT(!error || xlog_is_shutdown(log));
826
827 return error;
828}
829
830/*
831 * The mount has failed. Cancel the recovery if it hasn't completed and destroy
832 * the log.
833 */
834void
835xfs_log_mount_cancel(
836 struct xfs_mount *mp)
837{
838 xlog_recover_cancel(mp->m_log);
839 xfs_log_unmount(mp);
840}
841
842/*
843 * Flush out the iclog to disk ensuring that device caches are flushed and
844 * the iclog hits stable storage before any completion waiters are woken.
845 */
846static inline int
847xlog_force_iclog(
848 struct xlog_in_core *iclog)
849{
850 atomic_inc(&iclog->ic_refcnt);
851 iclog->ic_flags |= XLOG_ICL_NEED_FLUSH | XLOG_ICL_NEED_FUA;
852 if (iclog->ic_state == XLOG_STATE_ACTIVE)
853 xlog_state_switch_iclogs(iclog->ic_log, iclog, 0);
854 return xlog_state_release_iclog(iclog->ic_log, iclog, NULL);
855}
856
857/*
858 * Cycle all the iclogbuf locks to make sure all log IO completion
859 * is done before we tear down these buffers.
860 */
861static void
862xlog_wait_iclog_completion(struct xlog *log)
863{
864 int i;
865 struct xlog_in_core *iclog = log->l_iclog;
866
867 for (i = 0; i < log->l_iclog_bufs; i++) {
868 down(&iclog->ic_sema);
869 up(&iclog->ic_sema);
870 iclog = iclog->ic_next;
871 }
872}
873
874/*
875 * Wait for the iclog and all prior iclogs to be written disk as required by the
876 * log force state machine. Waiting on ic_force_wait ensures iclog completions
877 * have been ordered and callbacks run before we are woken here, hence
878 * guaranteeing that all the iclogs up to this one are on stable storage.
879 */
880int
881xlog_wait_on_iclog(
882 struct xlog_in_core *iclog)
883 __releases(iclog->ic_log->l_icloglock)
884{
885 struct xlog *log = iclog->ic_log;
886
887 trace_xlog_iclog_wait_on(iclog, _RET_IP_);
888 if (!xlog_is_shutdown(log) &&
889 iclog->ic_state != XLOG_STATE_ACTIVE &&
890 iclog->ic_state != XLOG_STATE_DIRTY) {
891 XFS_STATS_INC(log->l_mp, xs_log_force_sleep);
892 xlog_wait(&iclog->ic_force_wait, &log->l_icloglock);
893 } else {
894 spin_unlock(&log->l_icloglock);
895 }
896
897 if (xlog_is_shutdown(log))
898 return -EIO;
899 return 0;
900}
901
902/*
903 * Write out an unmount record using the ticket provided. We have to account for
904 * the data space used in the unmount ticket as this write is not done from a
905 * transaction context that has already done the accounting for us.
906 */
907static int
908xlog_write_unmount_record(
909 struct xlog *log,
910 struct xlog_ticket *ticket)
911{
912 struct {
913 struct xlog_op_header ophdr;
914 struct xfs_unmount_log_format ulf;
915 } unmount_rec = {
916 .ophdr = {
917 .oh_clientid = XFS_LOG,
918 .oh_tid = cpu_to_be32(ticket->t_tid),
919 .oh_flags = XLOG_UNMOUNT_TRANS,
920 },
921 .ulf = {
922 .magic = XLOG_UNMOUNT_TYPE,
923 },
924 };
925 struct xfs_log_iovec reg = {
926 .i_addr = &unmount_rec,
927 .i_len = sizeof(unmount_rec),
928 .i_type = XLOG_REG_TYPE_UNMOUNT,
929 };
930 struct xfs_log_vec vec = {
931 .lv_niovecs = 1,
932 .lv_iovecp = ®,
933 };
934 LIST_HEAD(lv_chain);
935 list_add(&vec.lv_list, &lv_chain);
936
937 BUILD_BUG_ON((sizeof(struct xlog_op_header) +
938 sizeof(struct xfs_unmount_log_format)) !=
939 sizeof(unmount_rec));
940
941 /* account for space used by record data */
942 ticket->t_curr_res -= sizeof(unmount_rec);
943
944 return xlog_write(log, NULL, &lv_chain, ticket, reg.i_len);
945}
946
947/*
948 * Mark the filesystem clean by writing an unmount record to the head of the
949 * log.
950 */
951static void
952xlog_unmount_write(
953 struct xlog *log)
954{
955 struct xfs_mount *mp = log->l_mp;
956 struct xlog_in_core *iclog;
957 struct xlog_ticket *tic = NULL;
958 int error;
959
960 error = xfs_log_reserve(mp, 600, 1, &tic, 0);
961 if (error)
962 goto out_err;
963
964 error = xlog_write_unmount_record(log, tic);
965 /*
966 * At this point, we're umounting anyway, so there's no point in
967 * transitioning log state to shutdown. Just continue...
968 */
969out_err:
970 if (error)
971 xfs_alert(mp, "%s: unmount record failed", __func__);
972
973 spin_lock(&log->l_icloglock);
974 iclog = log->l_iclog;
975 error = xlog_force_iclog(iclog);
976 xlog_wait_on_iclog(iclog);
977
978 if (tic) {
979 trace_xfs_log_umount_write(log, tic);
980 xfs_log_ticket_ungrant(log, tic);
981 }
982}
983
984static void
985xfs_log_unmount_verify_iclog(
986 struct xlog *log)
987{
988 struct xlog_in_core *iclog = log->l_iclog;
989
990 do {
991 ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE);
992 ASSERT(iclog->ic_offset == 0);
993 } while ((iclog = iclog->ic_next) != log->l_iclog);
994}
995
996/*
997 * Unmount record used to have a string "Unmount filesystem--" in the
998 * data section where the "Un" was really a magic number (XLOG_UNMOUNT_TYPE).
999 * We just write the magic number now since that particular field isn't
1000 * currently architecture converted and "Unmount" is a bit foo.
1001 * As far as I know, there weren't any dependencies on the old behaviour.
1002 */
1003static void
1004xfs_log_unmount_write(
1005 struct xfs_mount *mp)
1006{
1007 struct xlog *log = mp->m_log;
1008
1009 if (!xfs_log_writable(mp))
1010 return;
1011
1012 xfs_log_force(mp, XFS_LOG_SYNC);
1013
1014 if (xlog_is_shutdown(log))
1015 return;
1016
1017 /*
1018 * If we think the summary counters are bad, avoid writing the unmount
1019 * record to force log recovery at next mount, after which the summary
1020 * counters will be recalculated. Refer to xlog_check_unmount_rec for
1021 * more details.
1022 */
1023 if (XFS_TEST_ERROR(xfs_fs_has_sickness(mp, XFS_SICK_FS_COUNTERS), mp,
1024 XFS_ERRTAG_FORCE_SUMMARY_RECALC)) {
1025 xfs_alert(mp, "%s: will fix summary counters at next mount",
1026 __func__);
1027 return;
1028 }
1029
1030 xfs_log_unmount_verify_iclog(log);
1031 xlog_unmount_write(log);
1032}
1033
1034/*
1035 * Empty the log for unmount/freeze.
1036 *
1037 * To do this, we first need to shut down the background log work so it is not
1038 * trying to cover the log as we clean up. We then need to unpin all objects in
1039 * the log so we can then flush them out. Once they have completed their IO and
1040 * run the callbacks removing themselves from the AIL, we can cover the log.
1041 */
1042int
1043xfs_log_quiesce(
1044 struct xfs_mount *mp)
1045{
1046 /*
1047 * Clear log incompat features since we're quiescing the log. Report
1048 * failures, though it's not fatal to have a higher log feature
1049 * protection level than the log contents actually require.
1050 */
1051 if (xfs_clear_incompat_log_features(mp)) {
1052 int error;
1053
1054 error = xfs_sync_sb(mp, false);
1055 if (error)
1056 xfs_warn(mp,
1057 "Failed to clear log incompat features on quiesce");
1058 }
1059
1060 cancel_delayed_work_sync(&mp->m_log->l_work);
1061 xfs_log_force(mp, XFS_LOG_SYNC);
1062
1063 /*
1064 * The superblock buffer is uncached and while xfs_ail_push_all_sync()
1065 * will push it, xfs_buftarg_wait() will not wait for it. Further,
1066 * xfs_buf_iowait() cannot be used because it was pushed with the
1067 * XBF_ASYNC flag set, so we need to use a lock/unlock pair to wait for
1068 * the IO to complete.
1069 */
1070 xfs_ail_push_all_sync(mp->m_ail);
1071 xfs_buftarg_wait(mp->m_ddev_targp);
1072 xfs_buf_lock(mp->m_sb_bp);
1073 xfs_buf_unlock(mp->m_sb_bp);
1074
1075 return xfs_log_cover(mp);
1076}
1077
1078void
1079xfs_log_clean(
1080 struct xfs_mount *mp)
1081{
1082 xfs_log_quiesce(mp);
1083 xfs_log_unmount_write(mp);
1084}
1085
1086/*
1087 * Shut down and release the AIL and Log.
1088 *
1089 * During unmount, we need to ensure we flush all the dirty metadata objects
1090 * from the AIL so that the log is empty before we write the unmount record to
1091 * the log. Once this is done, we can tear down the AIL and the log.
1092 */
1093void
1094xfs_log_unmount(
1095 struct xfs_mount *mp)
1096{
1097 xfs_log_clean(mp);
1098
1099 /*
1100 * If shutdown has come from iclog IO context, the log
1101 * cleaning will have been skipped and so we need to wait
1102 * for the iclog to complete shutdown processing before we
1103 * tear anything down.
1104 */
1105 xlog_wait_iclog_completion(mp->m_log);
1106
1107 xfs_buftarg_drain(mp->m_ddev_targp);
1108
1109 xfs_trans_ail_destroy(mp);
1110
1111 xfs_sysfs_del(&mp->m_log->l_kobj);
1112
1113 xlog_dealloc_log(mp->m_log);
1114}
1115
1116void
1117xfs_log_item_init(
1118 struct xfs_mount *mp,
1119 struct xfs_log_item *item,
1120 int type,
1121 const struct xfs_item_ops *ops)
1122{
1123 item->li_log = mp->m_log;
1124 item->li_ailp = mp->m_ail;
1125 item->li_type = type;
1126 item->li_ops = ops;
1127 item->li_lv = NULL;
1128
1129 INIT_LIST_HEAD(&item->li_ail);
1130 INIT_LIST_HEAD(&item->li_cil);
1131 INIT_LIST_HEAD(&item->li_bio_list);
1132 INIT_LIST_HEAD(&item->li_trans);
1133}
1134
1135/*
1136 * Wake up processes waiting for log space after we have moved the log tail.
1137 */
1138void
1139xfs_log_space_wake(
1140 struct xfs_mount *mp)
1141{
1142 struct xlog *log = mp->m_log;
1143 int free_bytes;
1144
1145 if (xlog_is_shutdown(log))
1146 return;
1147
1148 if (!list_empty_careful(&log->l_write_head.waiters)) {
1149 ASSERT(!xlog_in_recovery(log));
1150
1151 spin_lock(&log->l_write_head.lock);
1152 free_bytes = xlog_space_left(log, &log->l_write_head.grant);
1153 xlog_grant_head_wake(log, &log->l_write_head, &free_bytes);
1154 spin_unlock(&log->l_write_head.lock);
1155 }
1156
1157 if (!list_empty_careful(&log->l_reserve_head.waiters)) {
1158 ASSERT(!xlog_in_recovery(log));
1159
1160 spin_lock(&log->l_reserve_head.lock);
1161 free_bytes = xlog_space_left(log, &log->l_reserve_head.grant);
1162 xlog_grant_head_wake(log, &log->l_reserve_head, &free_bytes);
1163 spin_unlock(&log->l_reserve_head.lock);
1164 }
1165}
1166
1167/*
1168 * Determine if we have a transaction that has gone to disk that needs to be
1169 * covered. To begin the transition to the idle state firstly the log needs to
1170 * be idle. That means the CIL, the AIL and the iclogs needs to be empty before
1171 * we start attempting to cover the log.
1172 *
1173 * Only if we are then in a state where covering is needed, the caller is
1174 * informed that dummy transactions are required to move the log into the idle
1175 * state.
1176 *
1177 * If there are any items in the AIl or CIL, then we do not want to attempt to
1178 * cover the log as we may be in a situation where there isn't log space
1179 * available to run a dummy transaction and this can lead to deadlocks when the
1180 * tail of the log is pinned by an item that is modified in the CIL. Hence
1181 * there's no point in running a dummy transaction at this point because we
1182 * can't start trying to idle the log until both the CIL and AIL are empty.
1183 */
1184static bool
1185xfs_log_need_covered(
1186 struct xfs_mount *mp)
1187{
1188 struct xlog *log = mp->m_log;
1189 bool needed = false;
1190
1191 if (!xlog_cil_empty(log))
1192 return false;
1193
1194 spin_lock(&log->l_icloglock);
1195 switch (log->l_covered_state) {
1196 case XLOG_STATE_COVER_DONE:
1197 case XLOG_STATE_COVER_DONE2:
1198 case XLOG_STATE_COVER_IDLE:
1199 break;
1200 case XLOG_STATE_COVER_NEED:
1201 case XLOG_STATE_COVER_NEED2:
1202 if (xfs_ail_min_lsn(log->l_ailp))
1203 break;
1204 if (!xlog_iclogs_empty(log))
1205 break;
1206
1207 needed = true;
1208 if (log->l_covered_state == XLOG_STATE_COVER_NEED)
1209 log->l_covered_state = XLOG_STATE_COVER_DONE;
1210 else
1211 log->l_covered_state = XLOG_STATE_COVER_DONE2;
1212 break;
1213 default:
1214 needed = true;
1215 break;
1216 }
1217 spin_unlock(&log->l_icloglock);
1218 return needed;
1219}
1220
1221/*
1222 * Explicitly cover the log. This is similar to background log covering but
1223 * intended for usage in quiesce codepaths. The caller is responsible to ensure
1224 * the log is idle and suitable for covering. The CIL, iclog buffers and AIL
1225 * must all be empty.
1226 */
1227static int
1228xfs_log_cover(
1229 struct xfs_mount *mp)
1230{
1231 int error = 0;
1232 bool need_covered;
1233
1234 ASSERT((xlog_cil_empty(mp->m_log) && xlog_iclogs_empty(mp->m_log) &&
1235 !xfs_ail_min_lsn(mp->m_log->l_ailp)) ||
1236 xlog_is_shutdown(mp->m_log));
1237
1238 if (!xfs_log_writable(mp))
1239 return 0;
1240
1241 /*
1242 * xfs_log_need_covered() is not idempotent because it progresses the
1243 * state machine if the log requires covering. Therefore, we must call
1244 * this function once and use the result until we've issued an sb sync.
1245 * Do so first to make that abundantly clear.
1246 *
1247 * Fall into the covering sequence if the log needs covering or the
1248 * mount has lazy superblock accounting to sync to disk. The sb sync
1249 * used for covering accumulates the in-core counters, so covering
1250 * handles this for us.
1251 */
1252 need_covered = xfs_log_need_covered(mp);
1253 if (!need_covered && !xfs_has_lazysbcount(mp))
1254 return 0;
1255
1256 /*
1257 * To cover the log, commit the superblock twice (at most) in
1258 * independent checkpoints. The first serves as a reference for the
1259 * tail pointer. The sync transaction and AIL push empties the AIL and
1260 * updates the in-core tail to the LSN of the first checkpoint. The
1261 * second commit updates the on-disk tail with the in-core LSN,
1262 * covering the log. Push the AIL one more time to leave it empty, as
1263 * we found it.
1264 */
1265 do {
1266 error = xfs_sync_sb(mp, true);
1267 if (error)
1268 break;
1269 xfs_ail_push_all_sync(mp->m_ail);
1270 } while (xfs_log_need_covered(mp));
1271
1272 return error;
1273}
1274
1275/*
1276 * We may be holding the log iclog lock upon entering this routine.
1277 */
1278xfs_lsn_t
1279xlog_assign_tail_lsn_locked(
1280 struct xfs_mount *mp)
1281{
1282 struct xlog *log = mp->m_log;
1283 struct xfs_log_item *lip;
1284 xfs_lsn_t tail_lsn;
1285
1286 assert_spin_locked(&mp->m_ail->ail_lock);
1287
1288 /*
1289 * To make sure we always have a valid LSN for the log tail we keep
1290 * track of the last LSN which was committed in log->l_last_sync_lsn,
1291 * and use that when the AIL was empty.
1292 */
1293 lip = xfs_ail_min(mp->m_ail);
1294 if (lip)
1295 tail_lsn = lip->li_lsn;
1296 else
1297 tail_lsn = atomic64_read(&log->l_last_sync_lsn);
1298 trace_xfs_log_assign_tail_lsn(log, tail_lsn);
1299 atomic64_set(&log->l_tail_lsn, tail_lsn);
1300 return tail_lsn;
1301}
1302
1303xfs_lsn_t
1304xlog_assign_tail_lsn(
1305 struct xfs_mount *mp)
1306{
1307 xfs_lsn_t tail_lsn;
1308
1309 spin_lock(&mp->m_ail->ail_lock);
1310 tail_lsn = xlog_assign_tail_lsn_locked(mp);
1311 spin_unlock(&mp->m_ail->ail_lock);
1312
1313 return tail_lsn;
1314}
1315
1316/*
1317 * Return the space in the log between the tail and the head. The head
1318 * is passed in the cycle/bytes formal parms. In the special case where
1319 * the reserve head has wrapped passed the tail, this calculation is no
1320 * longer valid. In this case, just return 0 which means there is no space
1321 * in the log. This works for all places where this function is called
1322 * with the reserve head. Of course, if the write head were to ever
1323 * wrap the tail, we should blow up. Rather than catch this case here,
1324 * we depend on other ASSERTions in other parts of the code. XXXmiken
1325 *
1326 * If reservation head is behind the tail, we have a problem. Warn about it,
1327 * but then treat it as if the log is empty.
1328 *
1329 * If the log is shut down, the head and tail may be invalid or out of whack, so
1330 * shortcut invalidity asserts in this case so that we don't trigger them
1331 * falsely.
1332 */
1333STATIC int
1334xlog_space_left(
1335 struct xlog *log,
1336 atomic64_t *head)
1337{
1338 int tail_bytes;
1339 int tail_cycle;
1340 int head_cycle;
1341 int head_bytes;
1342
1343 xlog_crack_grant_head(head, &head_cycle, &head_bytes);
1344 xlog_crack_atomic_lsn(&log->l_tail_lsn, &tail_cycle, &tail_bytes);
1345 tail_bytes = BBTOB(tail_bytes);
1346 if (tail_cycle == head_cycle && head_bytes >= tail_bytes)
1347 return log->l_logsize - (head_bytes - tail_bytes);
1348 if (tail_cycle + 1 < head_cycle)
1349 return 0;
1350
1351 /* Ignore potential inconsistency when shutdown. */
1352 if (xlog_is_shutdown(log))
1353 return log->l_logsize;
1354
1355 if (tail_cycle < head_cycle) {
1356 ASSERT(tail_cycle == (head_cycle - 1));
1357 return tail_bytes - head_bytes;
1358 }
1359
1360 /*
1361 * The reservation head is behind the tail. In this case we just want to
1362 * return the size of the log as the amount of space left.
1363 */
1364 xfs_alert(log->l_mp, "xlog_space_left: head behind tail");
1365 xfs_alert(log->l_mp, " tail_cycle = %d, tail_bytes = %d",
1366 tail_cycle, tail_bytes);
1367 xfs_alert(log->l_mp, " GH cycle = %d, GH bytes = %d",
1368 head_cycle, head_bytes);
1369 ASSERT(0);
1370 return log->l_logsize;
1371}
1372
1373
1374static void
1375xlog_ioend_work(
1376 struct work_struct *work)
1377{
1378 struct xlog_in_core *iclog =
1379 container_of(work, struct xlog_in_core, ic_end_io_work);
1380 struct xlog *log = iclog->ic_log;
1381 int error;
1382
1383 error = blk_status_to_errno(iclog->ic_bio.bi_status);
1384#ifdef DEBUG
1385 /* treat writes with injected CRC errors as failed */
1386 if (iclog->ic_fail_crc)
1387 error = -EIO;
1388#endif
1389
1390 /*
1391 * Race to shutdown the filesystem if we see an error.
1392 */
1393 if (XFS_TEST_ERROR(error, log->l_mp, XFS_ERRTAG_IODONE_IOERR)) {
1394 xfs_alert(log->l_mp, "log I/O error %d", error);
1395 xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR);
1396 }
1397
1398 xlog_state_done_syncing(iclog);
1399 bio_uninit(&iclog->ic_bio);
1400
1401 /*
1402 * Drop the lock to signal that we are done. Nothing references the
1403 * iclog after this, so an unmount waiting on this lock can now tear it
1404 * down safely. As such, it is unsafe to reference the iclog after the
1405 * unlock as we could race with it being freed.
1406 */
1407 up(&iclog->ic_sema);
1408}
1409
1410/*
1411 * Return size of each in-core log record buffer.
1412 *
1413 * All machines get 8 x 32kB buffers by default, unless tuned otherwise.
1414 *
1415 * If the filesystem blocksize is too large, we may need to choose a
1416 * larger size since the directory code currently logs entire blocks.
1417 */
1418STATIC void
1419xlog_get_iclog_buffer_size(
1420 struct xfs_mount *mp,
1421 struct xlog *log)
1422{
1423 if (mp->m_logbufs <= 0)
1424 mp->m_logbufs = XLOG_MAX_ICLOGS;
1425 if (mp->m_logbsize <= 0)
1426 mp->m_logbsize = XLOG_BIG_RECORD_BSIZE;
1427
1428 log->l_iclog_bufs = mp->m_logbufs;
1429 log->l_iclog_size = mp->m_logbsize;
1430
1431 /*
1432 * # headers = size / 32k - one header holds cycles from 32k of data.
1433 */
1434 log->l_iclog_heads =
1435 DIV_ROUND_UP(mp->m_logbsize, XLOG_HEADER_CYCLE_SIZE);
1436 log->l_iclog_hsize = log->l_iclog_heads << BBSHIFT;
1437}
1438
1439void
1440xfs_log_work_queue(
1441 struct xfs_mount *mp)
1442{
1443 queue_delayed_work(mp->m_sync_workqueue, &mp->m_log->l_work,
1444 msecs_to_jiffies(xfs_syncd_centisecs * 10));
1445}
1446
1447/*
1448 * Clear the log incompat flags if we have the opportunity.
1449 *
1450 * This only happens if we're about to log the second dummy transaction as part
1451 * of covering the log and we can get the log incompat feature usage lock.
1452 */
1453static inline void
1454xlog_clear_incompat(
1455 struct xlog *log)
1456{
1457 struct xfs_mount *mp = log->l_mp;
1458
1459 if (!xfs_sb_has_incompat_log_feature(&mp->m_sb,
1460 XFS_SB_FEAT_INCOMPAT_LOG_ALL))
1461 return;
1462
1463 if (log->l_covered_state != XLOG_STATE_COVER_DONE2)
1464 return;
1465
1466 if (!down_write_trylock(&log->l_incompat_users))
1467 return;
1468
1469 xfs_clear_incompat_log_features(mp);
1470 up_write(&log->l_incompat_users);
1471}
1472
1473/*
1474 * Every sync period we need to unpin all items in the AIL and push them to
1475 * disk. If there is nothing dirty, then we might need to cover the log to
1476 * indicate that the filesystem is idle.
1477 */
1478static void
1479xfs_log_worker(
1480 struct work_struct *work)
1481{
1482 struct xlog *log = container_of(to_delayed_work(work),
1483 struct xlog, l_work);
1484 struct xfs_mount *mp = log->l_mp;
1485
1486 /* dgc: errors ignored - not fatal and nowhere to report them */
1487 if (xfs_fs_writable(mp, SB_FREEZE_WRITE) && xfs_log_need_covered(mp)) {
1488 /*
1489 * Dump a transaction into the log that contains no real change.
1490 * This is needed to stamp the current tail LSN into the log
1491 * during the covering operation.
1492 *
1493 * We cannot use an inode here for this - that will push dirty
1494 * state back up into the VFS and then periodic inode flushing
1495 * will prevent log covering from making progress. Hence we
1496 * synchronously log the superblock instead to ensure the
1497 * superblock is immediately unpinned and can be written back.
1498 */
1499 xlog_clear_incompat(log);
1500 xfs_sync_sb(mp, true);
1501 } else
1502 xfs_log_force(mp, 0);
1503
1504 /* start pushing all the metadata that is currently dirty */
1505 xfs_ail_push_all(mp->m_ail);
1506
1507 /* queue us up again */
1508 xfs_log_work_queue(mp);
1509}
1510
1511/*
1512 * This routine initializes some of the log structure for a given mount point.
1513 * Its primary purpose is to fill in enough, so recovery can occur. However,
1514 * some other stuff may be filled in too.
1515 */
1516STATIC struct xlog *
1517xlog_alloc_log(
1518 struct xfs_mount *mp,
1519 struct xfs_buftarg *log_target,
1520 xfs_daddr_t blk_offset,
1521 int num_bblks)
1522{
1523 struct xlog *log;
1524 xlog_rec_header_t *head;
1525 xlog_in_core_t **iclogp;
1526 xlog_in_core_t *iclog, *prev_iclog=NULL;
1527 int i;
1528 int error = -ENOMEM;
1529 uint log2_size = 0;
1530
1531 log = kmem_zalloc(sizeof(struct xlog), KM_MAYFAIL);
1532 if (!log) {
1533 xfs_warn(mp, "Log allocation failed: No memory!");
1534 goto out;
1535 }
1536
1537 log->l_mp = mp;
1538 log->l_targ = log_target;
1539 log->l_logsize = BBTOB(num_bblks);
1540 log->l_logBBstart = blk_offset;
1541 log->l_logBBsize = num_bblks;
1542 log->l_covered_state = XLOG_STATE_COVER_IDLE;
1543 set_bit(XLOG_ACTIVE_RECOVERY, &log->l_opstate);
1544 INIT_DELAYED_WORK(&log->l_work, xfs_log_worker);
1545 INIT_LIST_HEAD(&log->r_dfops);
1546
1547 log->l_prev_block = -1;
1548 /* log->l_tail_lsn = 0x100000000LL; cycle = 1; current block = 0 */
1549 xlog_assign_atomic_lsn(&log->l_tail_lsn, 1, 0);
1550 xlog_assign_atomic_lsn(&log->l_last_sync_lsn, 1, 0);
1551 log->l_curr_cycle = 1; /* 0 is bad since this is initial value */
1552
1553 if (xfs_has_logv2(mp) && mp->m_sb.sb_logsunit > 1)
1554 log->l_iclog_roundoff = mp->m_sb.sb_logsunit;
1555 else
1556 log->l_iclog_roundoff = BBSIZE;
1557
1558 xlog_grant_head_init(&log->l_reserve_head);
1559 xlog_grant_head_init(&log->l_write_head);
1560
1561 error = -EFSCORRUPTED;
1562 if (xfs_has_sector(mp)) {
1563 log2_size = mp->m_sb.sb_logsectlog;
1564 if (log2_size < BBSHIFT) {
1565 xfs_warn(mp, "Log sector size too small (0x%x < 0x%x)",
1566 log2_size, BBSHIFT);
1567 goto out_free_log;
1568 }
1569
1570 log2_size -= BBSHIFT;
1571 if (log2_size > mp->m_sectbb_log) {
1572 xfs_warn(mp, "Log sector size too large (0x%x > 0x%x)",
1573 log2_size, mp->m_sectbb_log);
1574 goto out_free_log;
1575 }
1576
1577 /* for larger sector sizes, must have v2 or external log */
1578 if (log2_size && log->l_logBBstart > 0 &&
1579 !xfs_has_logv2(mp)) {
1580 xfs_warn(mp,
1581 "log sector size (0x%x) invalid for configuration.",
1582 log2_size);
1583 goto out_free_log;
1584 }
1585 }
1586 log->l_sectBBsize = 1 << log2_size;
1587
1588 init_rwsem(&log->l_incompat_users);
1589
1590 xlog_get_iclog_buffer_size(mp, log);
1591
1592 spin_lock_init(&log->l_icloglock);
1593 init_waitqueue_head(&log->l_flush_wait);
1594
1595 iclogp = &log->l_iclog;
1596 /*
1597 * The amount of memory to allocate for the iclog structure is
1598 * rather funky due to the way the structure is defined. It is
1599 * done this way so that we can use different sizes for machines
1600 * with different amounts of memory. See the definition of
1601 * xlog_in_core_t in xfs_log_priv.h for details.
1602 */
1603 ASSERT(log->l_iclog_size >= 4096);
1604 for (i = 0; i < log->l_iclog_bufs; i++) {
1605 size_t bvec_size = howmany(log->l_iclog_size, PAGE_SIZE) *
1606 sizeof(struct bio_vec);
1607
1608 iclog = kmem_zalloc(sizeof(*iclog) + bvec_size, KM_MAYFAIL);
1609 if (!iclog)
1610 goto out_free_iclog;
1611
1612 *iclogp = iclog;
1613 iclog->ic_prev = prev_iclog;
1614 prev_iclog = iclog;
1615
1616 iclog->ic_data = kvzalloc(log->l_iclog_size,
1617 GFP_KERNEL | __GFP_RETRY_MAYFAIL);
1618 if (!iclog->ic_data)
1619 goto out_free_iclog;
1620 head = &iclog->ic_header;
1621 memset(head, 0, sizeof(xlog_rec_header_t));
1622 head->h_magicno = cpu_to_be32(XLOG_HEADER_MAGIC_NUM);
1623 head->h_version = cpu_to_be32(
1624 xfs_has_logv2(log->l_mp) ? 2 : 1);
1625 head->h_size = cpu_to_be32(log->l_iclog_size);
1626 /* new fields */
1627 head->h_fmt = cpu_to_be32(XLOG_FMT);
1628 memcpy(&head->h_fs_uuid, &mp->m_sb.sb_uuid, sizeof(uuid_t));
1629
1630 iclog->ic_size = log->l_iclog_size - log->l_iclog_hsize;
1631 iclog->ic_state = XLOG_STATE_ACTIVE;
1632 iclog->ic_log = log;
1633 atomic_set(&iclog->ic_refcnt, 0);
1634 INIT_LIST_HEAD(&iclog->ic_callbacks);
1635 iclog->ic_datap = (void *)iclog->ic_data + log->l_iclog_hsize;
1636
1637 init_waitqueue_head(&iclog->ic_force_wait);
1638 init_waitqueue_head(&iclog->ic_write_wait);
1639 INIT_WORK(&iclog->ic_end_io_work, xlog_ioend_work);
1640 sema_init(&iclog->ic_sema, 1);
1641
1642 iclogp = &iclog->ic_next;
1643 }
1644 *iclogp = log->l_iclog; /* complete ring */
1645 log->l_iclog->ic_prev = prev_iclog; /* re-write 1st prev ptr */
1646
1647 log->l_ioend_workqueue = alloc_workqueue("xfs-log/%s",
1648 XFS_WQFLAGS(WQ_FREEZABLE | WQ_MEM_RECLAIM |
1649 WQ_HIGHPRI),
1650 0, mp->m_super->s_id);
1651 if (!log->l_ioend_workqueue)
1652 goto out_free_iclog;
1653
1654 error = xlog_cil_init(log);
1655 if (error)
1656 goto out_destroy_workqueue;
1657 return log;
1658
1659out_destroy_workqueue:
1660 destroy_workqueue(log->l_ioend_workqueue);
1661out_free_iclog:
1662 for (iclog = log->l_iclog; iclog; iclog = prev_iclog) {
1663 prev_iclog = iclog->ic_next;
1664 kmem_free(iclog->ic_data);
1665 kmem_free(iclog);
1666 if (prev_iclog == log->l_iclog)
1667 break;
1668 }
1669out_free_log:
1670 kmem_free(log);
1671out:
1672 return ERR_PTR(error);
1673} /* xlog_alloc_log */
1674
1675/*
1676 * Compute the LSN that we'd need to push the log tail towards in order to have
1677 * (a) enough on-disk log space to log the number of bytes specified, (b) at
1678 * least 25% of the log space free, and (c) at least 256 blocks free. If the
1679 * log free space already meets all three thresholds, this function returns
1680 * NULLCOMMITLSN.
1681 */
1682xfs_lsn_t
1683xlog_grant_push_threshold(
1684 struct xlog *log,
1685 int need_bytes)
1686{
1687 xfs_lsn_t threshold_lsn = 0;
1688 xfs_lsn_t last_sync_lsn;
1689 int free_blocks;
1690 int free_bytes;
1691 int threshold_block;
1692 int threshold_cycle;
1693 int free_threshold;
1694
1695 ASSERT(BTOBB(need_bytes) < log->l_logBBsize);
1696
1697 free_bytes = xlog_space_left(log, &log->l_reserve_head.grant);
1698 free_blocks = BTOBBT(free_bytes);
1699
1700 /*
1701 * Set the threshold for the minimum number of free blocks in the
1702 * log to the maximum of what the caller needs, one quarter of the
1703 * log, and 256 blocks.
1704 */
1705 free_threshold = BTOBB(need_bytes);
1706 free_threshold = max(free_threshold, (log->l_logBBsize >> 2));
1707 free_threshold = max(free_threshold, 256);
1708 if (free_blocks >= free_threshold)
1709 return NULLCOMMITLSN;
1710
1711 xlog_crack_atomic_lsn(&log->l_tail_lsn, &threshold_cycle,
1712 &threshold_block);
1713 threshold_block += free_threshold;
1714 if (threshold_block >= log->l_logBBsize) {
1715 threshold_block -= log->l_logBBsize;
1716 threshold_cycle += 1;
1717 }
1718 threshold_lsn = xlog_assign_lsn(threshold_cycle,
1719 threshold_block);
1720 /*
1721 * Don't pass in an lsn greater than the lsn of the last
1722 * log record known to be on disk. Use a snapshot of the last sync lsn
1723 * so that it doesn't change between the compare and the set.
1724 */
1725 last_sync_lsn = atomic64_read(&log->l_last_sync_lsn);
1726 if (XFS_LSN_CMP(threshold_lsn, last_sync_lsn) > 0)
1727 threshold_lsn = last_sync_lsn;
1728
1729 return threshold_lsn;
1730}
1731
1732/*
1733 * Push the tail of the log if we need to do so to maintain the free log space
1734 * thresholds set out by xlog_grant_push_threshold. We may need to adopt a
1735 * policy which pushes on an lsn which is further along in the log once we
1736 * reach the high water mark. In this manner, we would be creating a low water
1737 * mark.
1738 */
1739STATIC void
1740xlog_grant_push_ail(
1741 struct xlog *log,
1742 int need_bytes)
1743{
1744 xfs_lsn_t threshold_lsn;
1745
1746 threshold_lsn = xlog_grant_push_threshold(log, need_bytes);
1747 if (threshold_lsn == NULLCOMMITLSN || xlog_is_shutdown(log))
1748 return;
1749
1750 /*
1751 * Get the transaction layer to kick the dirty buffers out to
1752 * disk asynchronously. No point in trying to do this if
1753 * the filesystem is shutting down.
1754 */
1755 xfs_ail_push(log->l_ailp, threshold_lsn);
1756}
1757
1758/*
1759 * Stamp cycle number in every block
1760 */
1761STATIC void
1762xlog_pack_data(
1763 struct xlog *log,
1764 struct xlog_in_core *iclog,
1765 int roundoff)
1766{
1767 int i, j, k;
1768 int size = iclog->ic_offset + roundoff;
1769 __be32 cycle_lsn;
1770 char *dp;
1771
1772 cycle_lsn = CYCLE_LSN_DISK(iclog->ic_header.h_lsn);
1773
1774 dp = iclog->ic_datap;
1775 for (i = 0; i < BTOBB(size); i++) {
1776 if (i >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE))
1777 break;
1778 iclog->ic_header.h_cycle_data[i] = *(__be32 *)dp;
1779 *(__be32 *)dp = cycle_lsn;
1780 dp += BBSIZE;
1781 }
1782
1783 if (xfs_has_logv2(log->l_mp)) {
1784 xlog_in_core_2_t *xhdr = iclog->ic_data;
1785
1786 for ( ; i < BTOBB(size); i++) {
1787 j = i / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
1788 k = i % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
1789 xhdr[j].hic_xheader.xh_cycle_data[k] = *(__be32 *)dp;
1790 *(__be32 *)dp = cycle_lsn;
1791 dp += BBSIZE;
1792 }
1793
1794 for (i = 1; i < log->l_iclog_heads; i++)
1795 xhdr[i].hic_xheader.xh_cycle = cycle_lsn;
1796 }
1797}
1798
1799/*
1800 * Calculate the checksum for a log buffer.
1801 *
1802 * This is a little more complicated than it should be because the various
1803 * headers and the actual data are non-contiguous.
1804 */
1805__le32
1806xlog_cksum(
1807 struct xlog *log,
1808 struct xlog_rec_header *rhead,
1809 char *dp,
1810 int size)
1811{
1812 uint32_t crc;
1813
1814 /* first generate the crc for the record header ... */
1815 crc = xfs_start_cksum_update((char *)rhead,
1816 sizeof(struct xlog_rec_header),
1817 offsetof(struct xlog_rec_header, h_crc));
1818
1819 /* ... then for additional cycle data for v2 logs ... */
1820 if (xfs_has_logv2(log->l_mp)) {
1821 union xlog_in_core2 *xhdr = (union xlog_in_core2 *)rhead;
1822 int i;
1823 int xheads;
1824
1825 xheads = DIV_ROUND_UP(size, XLOG_HEADER_CYCLE_SIZE);
1826
1827 for (i = 1; i < xheads; i++) {
1828 crc = crc32c(crc, &xhdr[i].hic_xheader,
1829 sizeof(struct xlog_rec_ext_header));
1830 }
1831 }
1832
1833 /* ... and finally for the payload */
1834 crc = crc32c(crc, dp, size);
1835
1836 return xfs_end_cksum(crc);
1837}
1838
1839static void
1840xlog_bio_end_io(
1841 struct bio *bio)
1842{
1843 struct xlog_in_core *iclog = bio->bi_private;
1844
1845 queue_work(iclog->ic_log->l_ioend_workqueue,
1846 &iclog->ic_end_io_work);
1847}
1848
1849static int
1850xlog_map_iclog_data(
1851 struct bio *bio,
1852 void *data,
1853 size_t count)
1854{
1855 do {
1856 struct page *page = kmem_to_page(data);
1857 unsigned int off = offset_in_page(data);
1858 size_t len = min_t(size_t, count, PAGE_SIZE - off);
1859
1860 if (bio_add_page(bio, page, len, off) != len)
1861 return -EIO;
1862
1863 data += len;
1864 count -= len;
1865 } while (count);
1866
1867 return 0;
1868}
1869
1870STATIC void
1871xlog_write_iclog(
1872 struct xlog *log,
1873 struct xlog_in_core *iclog,
1874 uint64_t bno,
1875 unsigned int count)
1876{
1877 ASSERT(bno < log->l_logBBsize);
1878 trace_xlog_iclog_write(iclog, _RET_IP_);
1879
1880 /*
1881 * We lock the iclogbufs here so that we can serialise against I/O
1882 * completion during unmount. We might be processing a shutdown
1883 * triggered during unmount, and that can occur asynchronously to the
1884 * unmount thread, and hence we need to ensure that completes before
1885 * tearing down the iclogbufs. Hence we need to hold the buffer lock
1886 * across the log IO to archieve that.
1887 */
1888 down(&iclog->ic_sema);
1889 if (xlog_is_shutdown(log)) {
1890 /*
1891 * It would seem logical to return EIO here, but we rely on
1892 * the log state machine to propagate I/O errors instead of
1893 * doing it here. We kick of the state machine and unlock
1894 * the buffer manually, the code needs to be kept in sync
1895 * with the I/O completion path.
1896 */
1897 goto sync;
1898 }
1899
1900 /*
1901 * We use REQ_SYNC | REQ_IDLE here to tell the block layer the are more
1902 * IOs coming immediately after this one. This prevents the block layer
1903 * writeback throttle from throttling log writes behind background
1904 * metadata writeback and causing priority inversions.
1905 */
1906 bio_init(&iclog->ic_bio, log->l_targ->bt_bdev, iclog->ic_bvec,
1907 howmany(count, PAGE_SIZE),
1908 REQ_OP_WRITE | REQ_META | REQ_SYNC | REQ_IDLE);
1909 iclog->ic_bio.bi_iter.bi_sector = log->l_logBBstart + bno;
1910 iclog->ic_bio.bi_end_io = xlog_bio_end_io;
1911 iclog->ic_bio.bi_private = iclog;
1912
1913 if (iclog->ic_flags & XLOG_ICL_NEED_FLUSH) {
1914 iclog->ic_bio.bi_opf |= REQ_PREFLUSH;
1915 /*
1916 * For external log devices, we also need to flush the data
1917 * device cache first to ensure all metadata writeback covered
1918 * by the LSN in this iclog is on stable storage. This is slow,
1919 * but it *must* complete before we issue the external log IO.
1920 *
1921 * If the flush fails, we cannot conclude that past metadata
1922 * writeback from the log succeeded. Repeating the flush is
1923 * not possible, hence we must shut down with log IO error to
1924 * avoid shutdown re-entering this path and erroring out again.
1925 */
1926 if (log->l_targ != log->l_mp->m_ddev_targp &&
1927 blkdev_issue_flush(log->l_mp->m_ddev_targp->bt_bdev))
1928 goto shutdown;
1929 }
1930 if (iclog->ic_flags & XLOG_ICL_NEED_FUA)
1931 iclog->ic_bio.bi_opf |= REQ_FUA;
1932
1933 iclog->ic_flags &= ~(XLOG_ICL_NEED_FLUSH | XLOG_ICL_NEED_FUA);
1934
1935 if (xlog_map_iclog_data(&iclog->ic_bio, iclog->ic_data, count))
1936 goto shutdown;
1937
1938 if (is_vmalloc_addr(iclog->ic_data))
1939 flush_kernel_vmap_range(iclog->ic_data, count);
1940
1941 /*
1942 * If this log buffer would straddle the end of the log we will have
1943 * to split it up into two bios, so that we can continue at the start.
1944 */
1945 if (bno + BTOBB(count) > log->l_logBBsize) {
1946 struct bio *split;
1947
1948 split = bio_split(&iclog->ic_bio, log->l_logBBsize - bno,
1949 GFP_NOIO, &fs_bio_set);
1950 bio_chain(split, &iclog->ic_bio);
1951 submit_bio(split);
1952
1953 /* restart at logical offset zero for the remainder */
1954 iclog->ic_bio.bi_iter.bi_sector = log->l_logBBstart;
1955 }
1956
1957 submit_bio(&iclog->ic_bio);
1958 return;
1959shutdown:
1960 xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR);
1961sync:
1962 xlog_state_done_syncing(iclog);
1963 up(&iclog->ic_sema);
1964}
1965
1966/*
1967 * We need to bump cycle number for the part of the iclog that is
1968 * written to the start of the log. Watch out for the header magic
1969 * number case, though.
1970 */
1971static void
1972xlog_split_iclog(
1973 struct xlog *log,
1974 void *data,
1975 uint64_t bno,
1976 unsigned int count)
1977{
1978 unsigned int split_offset = BBTOB(log->l_logBBsize - bno);
1979 unsigned int i;
1980
1981 for (i = split_offset; i < count; i += BBSIZE) {
1982 uint32_t cycle = get_unaligned_be32(data + i);
1983
1984 if (++cycle == XLOG_HEADER_MAGIC_NUM)
1985 cycle++;
1986 put_unaligned_be32(cycle, data + i);
1987 }
1988}
1989
1990static int
1991xlog_calc_iclog_size(
1992 struct xlog *log,
1993 struct xlog_in_core *iclog,
1994 uint32_t *roundoff)
1995{
1996 uint32_t count_init, count;
1997
1998 /* Add for LR header */
1999 count_init = log->l_iclog_hsize + iclog->ic_offset;
2000 count = roundup(count_init, log->l_iclog_roundoff);
2001
2002 *roundoff = count - count_init;
2003
2004 ASSERT(count >= count_init);
2005 ASSERT(*roundoff < log->l_iclog_roundoff);
2006 return count;
2007}
2008
2009/*
2010 * Flush out the in-core log (iclog) to the on-disk log in an asynchronous
2011 * fashion. Previously, we should have moved the current iclog
2012 * ptr in the log to point to the next available iclog. This allows further
2013 * write to continue while this code syncs out an iclog ready to go.
2014 * Before an in-core log can be written out, the data section must be scanned
2015 * to save away the 1st word of each BBSIZE block into the header. We replace
2016 * it with the current cycle count. Each BBSIZE block is tagged with the
2017 * cycle count because there in an implicit assumption that drives will
2018 * guarantee that entire 512 byte blocks get written at once. In other words,
2019 * we can't have part of a 512 byte block written and part not written. By
2020 * tagging each block, we will know which blocks are valid when recovering
2021 * after an unclean shutdown.
2022 *
2023 * This routine is single threaded on the iclog. No other thread can be in
2024 * this routine with the same iclog. Changing contents of iclog can there-
2025 * fore be done without grabbing the state machine lock. Updating the global
2026 * log will require grabbing the lock though.
2027 *
2028 * The entire log manager uses a logical block numbering scheme. Only
2029 * xlog_write_iclog knows about the fact that the log may not start with
2030 * block zero on a given device.
2031 */
2032STATIC void
2033xlog_sync(
2034 struct xlog *log,
2035 struct xlog_in_core *iclog,
2036 struct xlog_ticket *ticket)
2037{
2038 unsigned int count; /* byte count of bwrite */
2039 unsigned int roundoff; /* roundoff to BB or stripe */
2040 uint64_t bno;
2041 unsigned int size;
2042
2043 ASSERT(atomic_read(&iclog->ic_refcnt) == 0);
2044 trace_xlog_iclog_sync(iclog, _RET_IP_);
2045
2046 count = xlog_calc_iclog_size(log, iclog, &roundoff);
2047
2048 /*
2049 * If we have a ticket, account for the roundoff via the ticket
2050 * reservation to avoid touching the hot grant heads needlessly.
2051 * Otherwise, we have to move grant heads directly.
2052 */
2053 if (ticket) {
2054 ticket->t_curr_res -= roundoff;
2055 } else {
2056 xlog_grant_add_space(log, &log->l_reserve_head.grant, roundoff);
2057 xlog_grant_add_space(log, &log->l_write_head.grant, roundoff);
2058 }
2059
2060 /* put cycle number in every block */
2061 xlog_pack_data(log, iclog, roundoff);
2062
2063 /* real byte length */
2064 size = iclog->ic_offset;
2065 if (xfs_has_logv2(log->l_mp))
2066 size += roundoff;
2067 iclog->ic_header.h_len = cpu_to_be32(size);
2068
2069 XFS_STATS_INC(log->l_mp, xs_log_writes);
2070 XFS_STATS_ADD(log->l_mp, xs_log_blocks, BTOBB(count));
2071
2072 bno = BLOCK_LSN(be64_to_cpu(iclog->ic_header.h_lsn));
2073
2074 /* Do we need to split this write into 2 parts? */
2075 if (bno + BTOBB(count) > log->l_logBBsize)
2076 xlog_split_iclog(log, &iclog->ic_header, bno, count);
2077
2078 /* calculcate the checksum */
2079 iclog->ic_header.h_crc = xlog_cksum(log, &iclog->ic_header,
2080 iclog->ic_datap, size);
2081 /*
2082 * Intentionally corrupt the log record CRC based on the error injection
2083 * frequency, if defined. This facilitates testing log recovery in the
2084 * event of torn writes. Hence, set the IOABORT state to abort the log
2085 * write on I/O completion and shutdown the fs. The subsequent mount
2086 * detects the bad CRC and attempts to recover.
2087 */
2088#ifdef DEBUG
2089 if (XFS_TEST_ERROR(false, log->l_mp, XFS_ERRTAG_LOG_BAD_CRC)) {
2090 iclog->ic_header.h_crc &= cpu_to_le32(0xAAAAAAAA);
2091 iclog->ic_fail_crc = true;
2092 xfs_warn(log->l_mp,
2093 "Intentionally corrupted log record at LSN 0x%llx. Shutdown imminent.",
2094 be64_to_cpu(iclog->ic_header.h_lsn));
2095 }
2096#endif
2097 xlog_verify_iclog(log, iclog, count);
2098 xlog_write_iclog(log, iclog, bno, count);
2099}
2100
2101/*
2102 * Deallocate a log structure
2103 */
2104STATIC void
2105xlog_dealloc_log(
2106 struct xlog *log)
2107{
2108 xlog_in_core_t *iclog, *next_iclog;
2109 int i;
2110
2111 /*
2112 * Destroy the CIL after waiting for iclog IO completion because an
2113 * iclog EIO error will try to shut down the log, which accesses the
2114 * CIL to wake up the waiters.
2115 */
2116 xlog_cil_destroy(log);
2117
2118 iclog = log->l_iclog;
2119 for (i = 0; i < log->l_iclog_bufs; i++) {
2120 next_iclog = iclog->ic_next;
2121 kmem_free(iclog->ic_data);
2122 kmem_free(iclog);
2123 iclog = next_iclog;
2124 }
2125
2126 log->l_mp->m_log = NULL;
2127 destroy_workqueue(log->l_ioend_workqueue);
2128 kmem_free(log);
2129}
2130
2131/*
2132 * Update counters atomically now that memcpy is done.
2133 */
2134static inline void
2135xlog_state_finish_copy(
2136 struct xlog *log,
2137 struct xlog_in_core *iclog,
2138 int record_cnt,
2139 int copy_bytes)
2140{
2141 lockdep_assert_held(&log->l_icloglock);
2142
2143 be32_add_cpu(&iclog->ic_header.h_num_logops, record_cnt);
2144 iclog->ic_offset += copy_bytes;
2145}
2146
2147/*
2148 * print out info relating to regions written which consume
2149 * the reservation
2150 */
2151void
2152xlog_print_tic_res(
2153 struct xfs_mount *mp,
2154 struct xlog_ticket *ticket)
2155{
2156 xfs_warn(mp, "ticket reservation summary:");
2157 xfs_warn(mp, " unit res = %d bytes", ticket->t_unit_res);
2158 xfs_warn(mp, " current res = %d bytes", ticket->t_curr_res);
2159 xfs_warn(mp, " original count = %d", ticket->t_ocnt);
2160 xfs_warn(mp, " remaining count = %d", ticket->t_cnt);
2161}
2162
2163/*
2164 * Print a summary of the transaction.
2165 */
2166void
2167xlog_print_trans(
2168 struct xfs_trans *tp)
2169{
2170 struct xfs_mount *mp = tp->t_mountp;
2171 struct xfs_log_item *lip;
2172
2173 /* dump core transaction and ticket info */
2174 xfs_warn(mp, "transaction summary:");
2175 xfs_warn(mp, " log res = %d", tp->t_log_res);
2176 xfs_warn(mp, " log count = %d", tp->t_log_count);
2177 xfs_warn(mp, " flags = 0x%x", tp->t_flags);
2178
2179 xlog_print_tic_res(mp, tp->t_ticket);
2180
2181 /* dump each log item */
2182 list_for_each_entry(lip, &tp->t_items, li_trans) {
2183 struct xfs_log_vec *lv = lip->li_lv;
2184 struct xfs_log_iovec *vec;
2185 int i;
2186
2187 xfs_warn(mp, "log item: ");
2188 xfs_warn(mp, " type = 0x%x", lip->li_type);
2189 xfs_warn(mp, " flags = 0x%lx", lip->li_flags);
2190 if (!lv)
2191 continue;
2192 xfs_warn(mp, " niovecs = %d", lv->lv_niovecs);
2193 xfs_warn(mp, " size = %d", lv->lv_size);
2194 xfs_warn(mp, " bytes = %d", lv->lv_bytes);
2195 xfs_warn(mp, " buf len = %d", lv->lv_buf_len);
2196
2197 /* dump each iovec for the log item */
2198 vec = lv->lv_iovecp;
2199 for (i = 0; i < lv->lv_niovecs; i++) {
2200 int dumplen = min(vec->i_len, 32);
2201
2202 xfs_warn(mp, " iovec[%d]", i);
2203 xfs_warn(mp, " type = 0x%x", vec->i_type);
2204 xfs_warn(mp, " len = %d", vec->i_len);
2205 xfs_warn(mp, " first %d bytes of iovec[%d]:", dumplen, i);
2206 xfs_hex_dump(vec->i_addr, dumplen);
2207
2208 vec++;
2209 }
2210 }
2211}
2212
2213static inline void
2214xlog_write_iovec(
2215 struct xlog_in_core *iclog,
2216 uint32_t *log_offset,
2217 void *data,
2218 uint32_t write_len,
2219 int *bytes_left,
2220 uint32_t *record_cnt,
2221 uint32_t *data_cnt)
2222{
2223 ASSERT(*log_offset < iclog->ic_log->l_iclog_size);
2224 ASSERT(*log_offset % sizeof(int32_t) == 0);
2225 ASSERT(write_len % sizeof(int32_t) == 0);
2226
2227 memcpy(iclog->ic_datap + *log_offset, data, write_len);
2228 *log_offset += write_len;
2229 *bytes_left -= write_len;
2230 (*record_cnt)++;
2231 *data_cnt += write_len;
2232}
2233
2234/*
2235 * Write log vectors into a single iclog which is guaranteed by the caller
2236 * to have enough space to write the entire log vector into.
2237 */
2238static void
2239xlog_write_full(
2240 struct xfs_log_vec *lv,
2241 struct xlog_ticket *ticket,
2242 struct xlog_in_core *iclog,
2243 uint32_t *log_offset,
2244 uint32_t *len,
2245 uint32_t *record_cnt,
2246 uint32_t *data_cnt)
2247{
2248 int index;
2249
2250 ASSERT(*log_offset + *len <= iclog->ic_size ||
2251 iclog->ic_state == XLOG_STATE_WANT_SYNC);
2252
2253 /*
2254 * Ordered log vectors have no regions to write so this
2255 * loop will naturally skip them.
2256 */
2257 for (index = 0; index < lv->lv_niovecs; index++) {
2258 struct xfs_log_iovec *reg = &lv->lv_iovecp[index];
2259 struct xlog_op_header *ophdr = reg->i_addr;
2260
2261 ophdr->oh_tid = cpu_to_be32(ticket->t_tid);
2262 xlog_write_iovec(iclog, log_offset, reg->i_addr,
2263 reg->i_len, len, record_cnt, data_cnt);
2264 }
2265}
2266
2267static int
2268xlog_write_get_more_iclog_space(
2269 struct xlog_ticket *ticket,
2270 struct xlog_in_core **iclogp,
2271 uint32_t *log_offset,
2272 uint32_t len,
2273 uint32_t *record_cnt,
2274 uint32_t *data_cnt)
2275{
2276 struct xlog_in_core *iclog = *iclogp;
2277 struct xlog *log = iclog->ic_log;
2278 int error;
2279
2280 spin_lock(&log->l_icloglock);
2281 ASSERT(iclog->ic_state == XLOG_STATE_WANT_SYNC);
2282 xlog_state_finish_copy(log, iclog, *record_cnt, *data_cnt);
2283 error = xlog_state_release_iclog(log, iclog, ticket);
2284 spin_unlock(&log->l_icloglock);
2285 if (error)
2286 return error;
2287
2288 error = xlog_state_get_iclog_space(log, len, &iclog, ticket,
2289 log_offset);
2290 if (error)
2291 return error;
2292 *record_cnt = 0;
2293 *data_cnt = 0;
2294 *iclogp = iclog;
2295 return 0;
2296}
2297
2298/*
2299 * Write log vectors into a single iclog which is smaller than the current chain
2300 * length. We write until we cannot fit a full record into the remaining space
2301 * and then stop. We return the log vector that is to be written that cannot
2302 * wholly fit in the iclog.
2303 */
2304static int
2305xlog_write_partial(
2306 struct xfs_log_vec *lv,
2307 struct xlog_ticket *ticket,
2308 struct xlog_in_core **iclogp,
2309 uint32_t *log_offset,
2310 uint32_t *len,
2311 uint32_t *record_cnt,
2312 uint32_t *data_cnt)
2313{
2314 struct xlog_in_core *iclog = *iclogp;
2315 struct xlog_op_header *ophdr;
2316 int index = 0;
2317 uint32_t rlen;
2318 int error;
2319
2320 /* walk the logvec, copying until we run out of space in the iclog */
2321 for (index = 0; index < lv->lv_niovecs; index++) {
2322 struct xfs_log_iovec *reg = &lv->lv_iovecp[index];
2323 uint32_t reg_offset = 0;
2324
2325 /*
2326 * The first region of a continuation must have a non-zero
2327 * length otherwise log recovery will just skip over it and
2328 * start recovering from the next opheader it finds. Because we
2329 * mark the next opheader as a continuation, recovery will then
2330 * incorrectly add the continuation to the previous region and
2331 * that breaks stuff.
2332 *
2333 * Hence if there isn't space for region data after the
2334 * opheader, then we need to start afresh with a new iclog.
2335 */
2336 if (iclog->ic_size - *log_offset <=
2337 sizeof(struct xlog_op_header)) {
2338 error = xlog_write_get_more_iclog_space(ticket,
2339 &iclog, log_offset, *len, record_cnt,
2340 data_cnt);
2341 if (error)
2342 return error;
2343 }
2344
2345 ophdr = reg->i_addr;
2346 rlen = min_t(uint32_t, reg->i_len, iclog->ic_size - *log_offset);
2347
2348 ophdr->oh_tid = cpu_to_be32(ticket->t_tid);
2349 ophdr->oh_len = cpu_to_be32(rlen - sizeof(struct xlog_op_header));
2350 if (rlen != reg->i_len)
2351 ophdr->oh_flags |= XLOG_CONTINUE_TRANS;
2352
2353 xlog_write_iovec(iclog, log_offset, reg->i_addr,
2354 rlen, len, record_cnt, data_cnt);
2355
2356 /* If we wrote the whole region, move to the next. */
2357 if (rlen == reg->i_len)
2358 continue;
2359
2360 /*
2361 * We now have a partially written iovec, but it can span
2362 * multiple iclogs so we loop here. First we release the iclog
2363 * we currently have, then we get a new iclog and add a new
2364 * opheader. Then we continue copying from where we were until
2365 * we either complete the iovec or fill the iclog. If we
2366 * complete the iovec, then we increment the index and go right
2367 * back to the top of the outer loop. if we fill the iclog, we
2368 * run the inner loop again.
2369 *
2370 * This is complicated by the tail of a region using all the
2371 * space in an iclog and hence requiring us to release the iclog
2372 * and get a new one before returning to the outer loop. We must
2373 * always guarantee that we exit this inner loop with at least
2374 * space for log transaction opheaders left in the current
2375 * iclog, hence we cannot just terminate the loop at the end
2376 * of the of the continuation. So we loop while there is no
2377 * space left in the current iclog, and check for the end of the
2378 * continuation after getting a new iclog.
2379 */
2380 do {
2381 /*
2382 * Ensure we include the continuation opheader in the
2383 * space we need in the new iclog by adding that size
2384 * to the length we require. This continuation opheader
2385 * needs to be accounted to the ticket as the space it
2386 * consumes hasn't been accounted to the lv we are
2387 * writing.
2388 */
2389 error = xlog_write_get_more_iclog_space(ticket,
2390 &iclog, log_offset,
2391 *len + sizeof(struct xlog_op_header),
2392 record_cnt, data_cnt);
2393 if (error)
2394 return error;
2395
2396 ophdr = iclog->ic_datap + *log_offset;
2397 ophdr->oh_tid = cpu_to_be32(ticket->t_tid);
2398 ophdr->oh_clientid = XFS_TRANSACTION;
2399 ophdr->oh_res2 = 0;
2400 ophdr->oh_flags = XLOG_WAS_CONT_TRANS;
2401
2402 ticket->t_curr_res -= sizeof(struct xlog_op_header);
2403 *log_offset += sizeof(struct xlog_op_header);
2404 *data_cnt += sizeof(struct xlog_op_header);
2405
2406 /*
2407 * If rlen fits in the iclog, then end the region
2408 * continuation. Otherwise we're going around again.
2409 */
2410 reg_offset += rlen;
2411 rlen = reg->i_len - reg_offset;
2412 if (rlen <= iclog->ic_size - *log_offset)
2413 ophdr->oh_flags |= XLOG_END_TRANS;
2414 else
2415 ophdr->oh_flags |= XLOG_CONTINUE_TRANS;
2416
2417 rlen = min_t(uint32_t, rlen, iclog->ic_size - *log_offset);
2418 ophdr->oh_len = cpu_to_be32(rlen);
2419
2420 xlog_write_iovec(iclog, log_offset,
2421 reg->i_addr + reg_offset,
2422 rlen, len, record_cnt, data_cnt);
2423
2424 } while (ophdr->oh_flags & XLOG_CONTINUE_TRANS);
2425 }
2426
2427 /*
2428 * No more iovecs remain in this logvec so return the next log vec to
2429 * the caller so it can go back to fast path copying.
2430 */
2431 *iclogp = iclog;
2432 return 0;
2433}
2434
2435/*
2436 * Write some region out to in-core log
2437 *
2438 * This will be called when writing externally provided regions or when
2439 * writing out a commit record for a given transaction.
2440 *
2441 * General algorithm:
2442 * 1. Find total length of this write. This may include adding to the
2443 * lengths passed in.
2444 * 2. Check whether we violate the tickets reservation.
2445 * 3. While writing to this iclog
2446 * A. Reserve as much space in this iclog as can get
2447 * B. If this is first write, save away start lsn
2448 * C. While writing this region:
2449 * 1. If first write of transaction, write start record
2450 * 2. Write log operation header (header per region)
2451 * 3. Find out if we can fit entire region into this iclog
2452 * 4. Potentially, verify destination memcpy ptr
2453 * 5. Memcpy (partial) region
2454 * 6. If partial copy, release iclog; otherwise, continue
2455 * copying more regions into current iclog
2456 * 4. Mark want sync bit (in simulation mode)
2457 * 5. Release iclog for potential flush to on-disk log.
2458 *
2459 * ERRORS:
2460 * 1. Panic if reservation is overrun. This should never happen since
2461 * reservation amounts are generated internal to the filesystem.
2462 * NOTES:
2463 * 1. Tickets are single threaded data structures.
2464 * 2. The XLOG_END_TRANS & XLOG_CONTINUE_TRANS flags are passed down to the
2465 * syncing routine. When a single log_write region needs to span
2466 * multiple in-core logs, the XLOG_CONTINUE_TRANS bit should be set
2467 * on all log operation writes which don't contain the end of the
2468 * region. The XLOG_END_TRANS bit is used for the in-core log
2469 * operation which contains the end of the continued log_write region.
2470 * 3. When xlog_state_get_iclog_space() grabs the rest of the current iclog,
2471 * we don't really know exactly how much space will be used. As a result,
2472 * we don't update ic_offset until the end when we know exactly how many
2473 * bytes have been written out.
2474 */
2475int
2476xlog_write(
2477 struct xlog *log,
2478 struct xfs_cil_ctx *ctx,
2479 struct list_head *lv_chain,
2480 struct xlog_ticket *ticket,
2481 uint32_t len)
2482
2483{
2484 struct xlog_in_core *iclog = NULL;
2485 struct xfs_log_vec *lv;
2486 uint32_t record_cnt = 0;
2487 uint32_t data_cnt = 0;
2488 int error = 0;
2489 int log_offset;
2490
2491 if (ticket->t_curr_res < 0) {
2492 xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES,
2493 "ctx ticket reservation ran out. Need to up reservation");
2494 xlog_print_tic_res(log->l_mp, ticket);
2495 xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR);
2496 }
2497
2498 error = xlog_state_get_iclog_space(log, len, &iclog, ticket,
2499 &log_offset);
2500 if (error)
2501 return error;
2502
2503 ASSERT(log_offset <= iclog->ic_size - 1);
2504
2505 /*
2506 * If we have a context pointer, pass it the first iclog we are
2507 * writing to so it can record state needed for iclog write
2508 * ordering.
2509 */
2510 if (ctx)
2511 xlog_cil_set_ctx_write_state(ctx, iclog);
2512
2513 list_for_each_entry(lv, lv_chain, lv_list) {
2514 /*
2515 * If the entire log vec does not fit in the iclog, punt it to
2516 * the partial copy loop which can handle this case.
2517 */
2518 if (lv->lv_niovecs &&
2519 lv->lv_bytes > iclog->ic_size - log_offset) {
2520 error = xlog_write_partial(lv, ticket, &iclog,
2521 &log_offset, &len, &record_cnt,
2522 &data_cnt);
2523 if (error) {
2524 /*
2525 * We have no iclog to release, so just return
2526 * the error immediately.
2527 */
2528 return error;
2529 }
2530 } else {
2531 xlog_write_full(lv, ticket, iclog, &log_offset,
2532 &len, &record_cnt, &data_cnt);
2533 }
2534 }
2535 ASSERT(len == 0);
2536
2537 /*
2538 * We've already been guaranteed that the last writes will fit inside
2539 * the current iclog, and hence it will already have the space used by
2540 * those writes accounted to it. Hence we do not need to update the
2541 * iclog with the number of bytes written here.
2542 */
2543 spin_lock(&log->l_icloglock);
2544 xlog_state_finish_copy(log, iclog, record_cnt, 0);
2545 error = xlog_state_release_iclog(log, iclog, ticket);
2546 spin_unlock(&log->l_icloglock);
2547
2548 return error;
2549}
2550
2551static void
2552xlog_state_activate_iclog(
2553 struct xlog_in_core *iclog,
2554 int *iclogs_changed)
2555{
2556 ASSERT(list_empty_careful(&iclog->ic_callbacks));
2557 trace_xlog_iclog_activate(iclog, _RET_IP_);
2558
2559 /*
2560 * If the number of ops in this iclog indicate it just contains the
2561 * dummy transaction, we can change state into IDLE (the second time
2562 * around). Otherwise we should change the state into NEED a dummy.
2563 * We don't need to cover the dummy.
2564 */
2565 if (*iclogs_changed == 0 &&
2566 iclog->ic_header.h_num_logops == cpu_to_be32(XLOG_COVER_OPS)) {
2567 *iclogs_changed = 1;
2568 } else {
2569 /*
2570 * We have two dirty iclogs so start over. This could also be
2571 * num of ops indicating this is not the dummy going out.
2572 */
2573 *iclogs_changed = 2;
2574 }
2575
2576 iclog->ic_state = XLOG_STATE_ACTIVE;
2577 iclog->ic_offset = 0;
2578 iclog->ic_header.h_num_logops = 0;
2579 memset(iclog->ic_header.h_cycle_data, 0,
2580 sizeof(iclog->ic_header.h_cycle_data));
2581 iclog->ic_header.h_lsn = 0;
2582 iclog->ic_header.h_tail_lsn = 0;
2583}
2584
2585/*
2586 * Loop through all iclogs and mark all iclogs currently marked DIRTY as
2587 * ACTIVE after iclog I/O has completed.
2588 */
2589static void
2590xlog_state_activate_iclogs(
2591 struct xlog *log,
2592 int *iclogs_changed)
2593{
2594 struct xlog_in_core *iclog = log->l_iclog;
2595
2596 do {
2597 if (iclog->ic_state == XLOG_STATE_DIRTY)
2598 xlog_state_activate_iclog(iclog, iclogs_changed);
2599 /*
2600 * The ordering of marking iclogs ACTIVE must be maintained, so
2601 * an iclog doesn't become ACTIVE beyond one that is SYNCING.
2602 */
2603 else if (iclog->ic_state != XLOG_STATE_ACTIVE)
2604 break;
2605 } while ((iclog = iclog->ic_next) != log->l_iclog);
2606}
2607
2608static int
2609xlog_covered_state(
2610 int prev_state,
2611 int iclogs_changed)
2612{
2613 /*
2614 * We go to NEED for any non-covering writes. We go to NEED2 if we just
2615 * wrote the first covering record (DONE). We go to IDLE if we just
2616 * wrote the second covering record (DONE2) and remain in IDLE until a
2617 * non-covering write occurs.
2618 */
2619 switch (prev_state) {
2620 case XLOG_STATE_COVER_IDLE:
2621 if (iclogs_changed == 1)
2622 return XLOG_STATE_COVER_IDLE;
2623 fallthrough;
2624 case XLOG_STATE_COVER_NEED:
2625 case XLOG_STATE_COVER_NEED2:
2626 break;
2627 case XLOG_STATE_COVER_DONE:
2628 if (iclogs_changed == 1)
2629 return XLOG_STATE_COVER_NEED2;
2630 break;
2631 case XLOG_STATE_COVER_DONE2:
2632 if (iclogs_changed == 1)
2633 return XLOG_STATE_COVER_IDLE;
2634 break;
2635 default:
2636 ASSERT(0);
2637 }
2638
2639 return XLOG_STATE_COVER_NEED;
2640}
2641
2642STATIC void
2643xlog_state_clean_iclog(
2644 struct xlog *log,
2645 struct xlog_in_core *dirty_iclog)
2646{
2647 int iclogs_changed = 0;
2648
2649 trace_xlog_iclog_clean(dirty_iclog, _RET_IP_);
2650
2651 dirty_iclog->ic_state = XLOG_STATE_DIRTY;
2652
2653 xlog_state_activate_iclogs(log, &iclogs_changed);
2654 wake_up_all(&dirty_iclog->ic_force_wait);
2655
2656 if (iclogs_changed) {
2657 log->l_covered_state = xlog_covered_state(log->l_covered_state,
2658 iclogs_changed);
2659 }
2660}
2661
2662STATIC xfs_lsn_t
2663xlog_get_lowest_lsn(
2664 struct xlog *log)
2665{
2666 struct xlog_in_core *iclog = log->l_iclog;
2667 xfs_lsn_t lowest_lsn = 0, lsn;
2668
2669 do {
2670 if (iclog->ic_state == XLOG_STATE_ACTIVE ||
2671 iclog->ic_state == XLOG_STATE_DIRTY)
2672 continue;
2673
2674 lsn = be64_to_cpu(iclog->ic_header.h_lsn);
2675 if ((lsn && !lowest_lsn) || XFS_LSN_CMP(lsn, lowest_lsn) < 0)
2676 lowest_lsn = lsn;
2677 } while ((iclog = iclog->ic_next) != log->l_iclog);
2678
2679 return lowest_lsn;
2680}
2681
2682/*
2683 * Completion of a iclog IO does not imply that a transaction has completed, as
2684 * transactions can be large enough to span many iclogs. We cannot change the
2685 * tail of the log half way through a transaction as this may be the only
2686 * transaction in the log and moving the tail to point to the middle of it
2687 * will prevent recovery from finding the start of the transaction. Hence we
2688 * should only update the last_sync_lsn if this iclog contains transaction
2689 * completion callbacks on it.
2690 *
2691 * We have to do this before we drop the icloglock to ensure we are the only one
2692 * that can update it.
2693 *
2694 * If we are moving the last_sync_lsn forwards, we also need to ensure we kick
2695 * the reservation grant head pushing. This is due to the fact that the push
2696 * target is bound by the current last_sync_lsn value. Hence if we have a large
2697 * amount of log space bound up in this committing transaction then the
2698 * last_sync_lsn value may be the limiting factor preventing tail pushing from
2699 * freeing space in the log. Hence once we've updated the last_sync_lsn we
2700 * should push the AIL to ensure the push target (and hence the grant head) is
2701 * no longer bound by the old log head location and can move forwards and make
2702 * progress again.
2703 */
2704static void
2705xlog_state_set_callback(
2706 struct xlog *log,
2707 struct xlog_in_core *iclog,
2708 xfs_lsn_t header_lsn)
2709{
2710 trace_xlog_iclog_callback(iclog, _RET_IP_);
2711 iclog->ic_state = XLOG_STATE_CALLBACK;
2712
2713 ASSERT(XFS_LSN_CMP(atomic64_read(&log->l_last_sync_lsn),
2714 header_lsn) <= 0);
2715
2716 if (list_empty_careful(&iclog->ic_callbacks))
2717 return;
2718
2719 atomic64_set(&log->l_last_sync_lsn, header_lsn);
2720 xlog_grant_push_ail(log, 0);
2721}
2722
2723/*
2724 * Return true if we need to stop processing, false to continue to the next
2725 * iclog. The caller will need to run callbacks if the iclog is returned in the
2726 * XLOG_STATE_CALLBACK state.
2727 */
2728static bool
2729xlog_state_iodone_process_iclog(
2730 struct xlog *log,
2731 struct xlog_in_core *iclog)
2732{
2733 xfs_lsn_t lowest_lsn;
2734 xfs_lsn_t header_lsn;
2735
2736 switch (iclog->ic_state) {
2737 case XLOG_STATE_ACTIVE:
2738 case XLOG_STATE_DIRTY:
2739 /*
2740 * Skip all iclogs in the ACTIVE & DIRTY states:
2741 */
2742 return false;
2743 case XLOG_STATE_DONE_SYNC:
2744 /*
2745 * Now that we have an iclog that is in the DONE_SYNC state, do
2746 * one more check here to see if we have chased our tail around.
2747 * If this is not the lowest lsn iclog, then we will leave it
2748 * for another completion to process.
2749 */
2750 header_lsn = be64_to_cpu(iclog->ic_header.h_lsn);
2751 lowest_lsn = xlog_get_lowest_lsn(log);
2752 if (lowest_lsn && XFS_LSN_CMP(lowest_lsn, header_lsn) < 0)
2753 return false;
2754 xlog_state_set_callback(log, iclog, header_lsn);
2755 return false;
2756 default:
2757 /*
2758 * Can only perform callbacks in order. Since this iclog is not
2759 * in the DONE_SYNC state, we skip the rest and just try to
2760 * clean up.
2761 */
2762 return true;
2763 }
2764}
2765
2766/*
2767 * Loop over all the iclogs, running attached callbacks on them. Return true if
2768 * we ran any callbacks, indicating that we dropped the icloglock. We don't need
2769 * to handle transient shutdown state here at all because
2770 * xlog_state_shutdown_callbacks() will be run to do the necessary shutdown
2771 * cleanup of the callbacks.
2772 */
2773static bool
2774xlog_state_do_iclog_callbacks(
2775 struct xlog *log)
2776 __releases(&log->l_icloglock)
2777 __acquires(&log->l_icloglock)
2778{
2779 struct xlog_in_core *first_iclog = log->l_iclog;
2780 struct xlog_in_core *iclog = first_iclog;
2781 bool ran_callback = false;
2782
2783 do {
2784 LIST_HEAD(cb_list);
2785
2786 if (xlog_state_iodone_process_iclog(log, iclog))
2787 break;
2788 if (iclog->ic_state != XLOG_STATE_CALLBACK) {
2789 iclog = iclog->ic_next;
2790 continue;
2791 }
2792 list_splice_init(&iclog->ic_callbacks, &cb_list);
2793 spin_unlock(&log->l_icloglock);
2794
2795 trace_xlog_iclog_callbacks_start(iclog, _RET_IP_);
2796 xlog_cil_process_committed(&cb_list);
2797 trace_xlog_iclog_callbacks_done(iclog, _RET_IP_);
2798 ran_callback = true;
2799
2800 spin_lock(&log->l_icloglock);
2801 xlog_state_clean_iclog(log, iclog);
2802 iclog = iclog->ic_next;
2803 } while (iclog != first_iclog);
2804
2805 return ran_callback;
2806}
2807
2808
2809/*
2810 * Loop running iclog completion callbacks until there are no more iclogs in a
2811 * state that can run callbacks.
2812 */
2813STATIC void
2814xlog_state_do_callback(
2815 struct xlog *log)
2816{
2817 int flushcnt = 0;
2818 int repeats = 0;
2819
2820 spin_lock(&log->l_icloglock);
2821 while (xlog_state_do_iclog_callbacks(log)) {
2822 if (xlog_is_shutdown(log))
2823 break;
2824
2825 if (++repeats > 5000) {
2826 flushcnt += repeats;
2827 repeats = 0;
2828 xfs_warn(log->l_mp,
2829 "%s: possible infinite loop (%d iterations)",
2830 __func__, flushcnt);
2831 }
2832 }
2833
2834 if (log->l_iclog->ic_state == XLOG_STATE_ACTIVE)
2835 wake_up_all(&log->l_flush_wait);
2836
2837 spin_unlock(&log->l_icloglock);
2838}
2839
2840
2841/*
2842 * Finish transitioning this iclog to the dirty state.
2843 *
2844 * Callbacks could take time, so they are done outside the scope of the
2845 * global state machine log lock.
2846 */
2847STATIC void
2848xlog_state_done_syncing(
2849 struct xlog_in_core *iclog)
2850{
2851 struct xlog *log = iclog->ic_log;
2852
2853 spin_lock(&log->l_icloglock);
2854 ASSERT(atomic_read(&iclog->ic_refcnt) == 0);
2855 trace_xlog_iclog_sync_done(iclog, _RET_IP_);
2856
2857 /*
2858 * If we got an error, either on the first buffer, or in the case of
2859 * split log writes, on the second, we shut down the file system and
2860 * no iclogs should ever be attempted to be written to disk again.
2861 */
2862 if (!xlog_is_shutdown(log)) {
2863 ASSERT(iclog->ic_state == XLOG_STATE_SYNCING);
2864 iclog->ic_state = XLOG_STATE_DONE_SYNC;
2865 }
2866
2867 /*
2868 * Someone could be sleeping prior to writing out the next
2869 * iclog buffer, we wake them all, one will get to do the
2870 * I/O, the others get to wait for the result.
2871 */
2872 wake_up_all(&iclog->ic_write_wait);
2873 spin_unlock(&log->l_icloglock);
2874 xlog_state_do_callback(log);
2875}
2876
2877/*
2878 * If the head of the in-core log ring is not (ACTIVE or DIRTY), then we must
2879 * sleep. We wait on the flush queue on the head iclog as that should be
2880 * the first iclog to complete flushing. Hence if all iclogs are syncing,
2881 * we will wait here and all new writes will sleep until a sync completes.
2882 *
2883 * The in-core logs are used in a circular fashion. They are not used
2884 * out-of-order even when an iclog past the head is free.
2885 *
2886 * return:
2887 * * log_offset where xlog_write() can start writing into the in-core
2888 * log's data space.
2889 * * in-core log pointer to which xlog_write() should write.
2890 * * boolean indicating this is a continued write to an in-core log.
2891 * If this is the last write, then the in-core log's offset field
2892 * needs to be incremented, depending on the amount of data which
2893 * is copied.
2894 */
2895STATIC int
2896xlog_state_get_iclog_space(
2897 struct xlog *log,
2898 int len,
2899 struct xlog_in_core **iclogp,
2900 struct xlog_ticket *ticket,
2901 int *logoffsetp)
2902{
2903 int log_offset;
2904 xlog_rec_header_t *head;
2905 xlog_in_core_t *iclog;
2906
2907restart:
2908 spin_lock(&log->l_icloglock);
2909 if (xlog_is_shutdown(log)) {
2910 spin_unlock(&log->l_icloglock);
2911 return -EIO;
2912 }
2913
2914 iclog = log->l_iclog;
2915 if (iclog->ic_state != XLOG_STATE_ACTIVE) {
2916 XFS_STATS_INC(log->l_mp, xs_log_noiclogs);
2917
2918 /* Wait for log writes to have flushed */
2919 xlog_wait(&log->l_flush_wait, &log->l_icloglock);
2920 goto restart;
2921 }
2922
2923 head = &iclog->ic_header;
2924
2925 atomic_inc(&iclog->ic_refcnt); /* prevents sync */
2926 log_offset = iclog->ic_offset;
2927
2928 trace_xlog_iclog_get_space(iclog, _RET_IP_);
2929
2930 /* On the 1st write to an iclog, figure out lsn. This works
2931 * if iclogs marked XLOG_STATE_WANT_SYNC always write out what they are
2932 * committing to. If the offset is set, that's how many blocks
2933 * must be written.
2934 */
2935 if (log_offset == 0) {
2936 ticket->t_curr_res -= log->l_iclog_hsize;
2937 head->h_cycle = cpu_to_be32(log->l_curr_cycle);
2938 head->h_lsn = cpu_to_be64(
2939 xlog_assign_lsn(log->l_curr_cycle, log->l_curr_block));
2940 ASSERT(log->l_curr_block >= 0);
2941 }
2942
2943 /* If there is enough room to write everything, then do it. Otherwise,
2944 * claim the rest of the region and make sure the XLOG_STATE_WANT_SYNC
2945 * bit is on, so this will get flushed out. Don't update ic_offset
2946 * until you know exactly how many bytes get copied. Therefore, wait
2947 * until later to update ic_offset.
2948 *
2949 * xlog_write() algorithm assumes that at least 2 xlog_op_header_t's
2950 * can fit into remaining data section.
2951 */
2952 if (iclog->ic_size - iclog->ic_offset < 2*sizeof(xlog_op_header_t)) {
2953 int error = 0;
2954
2955 xlog_state_switch_iclogs(log, iclog, iclog->ic_size);
2956
2957 /*
2958 * If we are the only one writing to this iclog, sync it to
2959 * disk. We need to do an atomic compare and decrement here to
2960 * avoid racing with concurrent atomic_dec_and_lock() calls in
2961 * xlog_state_release_iclog() when there is more than one
2962 * reference to the iclog.
2963 */
2964 if (!atomic_add_unless(&iclog->ic_refcnt, -1, 1))
2965 error = xlog_state_release_iclog(log, iclog, ticket);
2966 spin_unlock(&log->l_icloglock);
2967 if (error)
2968 return error;
2969 goto restart;
2970 }
2971
2972 /* Do we have enough room to write the full amount in the remainder
2973 * of this iclog? Or must we continue a write on the next iclog and
2974 * mark this iclog as completely taken? In the case where we switch
2975 * iclogs (to mark it taken), this particular iclog will release/sync
2976 * to disk in xlog_write().
2977 */
2978 if (len <= iclog->ic_size - iclog->ic_offset)
2979 iclog->ic_offset += len;
2980 else
2981 xlog_state_switch_iclogs(log, iclog, iclog->ic_size);
2982 *iclogp = iclog;
2983
2984 ASSERT(iclog->ic_offset <= iclog->ic_size);
2985 spin_unlock(&log->l_icloglock);
2986
2987 *logoffsetp = log_offset;
2988 return 0;
2989}
2990
2991/*
2992 * The first cnt-1 times a ticket goes through here we don't need to move the
2993 * grant write head because the permanent reservation has reserved cnt times the
2994 * unit amount. Release part of current permanent unit reservation and reset
2995 * current reservation to be one units worth. Also move grant reservation head
2996 * forward.
2997 */
2998void
2999xfs_log_ticket_regrant(
3000 struct xlog *log,
3001 struct xlog_ticket *ticket)
3002{
3003 trace_xfs_log_ticket_regrant(log, ticket);
3004
3005 if (ticket->t_cnt > 0)
3006 ticket->t_cnt--;
3007
3008 xlog_grant_sub_space(log, &log->l_reserve_head.grant,
3009 ticket->t_curr_res);
3010 xlog_grant_sub_space(log, &log->l_write_head.grant,
3011 ticket->t_curr_res);
3012 ticket->t_curr_res = ticket->t_unit_res;
3013
3014 trace_xfs_log_ticket_regrant_sub(log, ticket);
3015
3016 /* just return if we still have some of the pre-reserved space */
3017 if (!ticket->t_cnt) {
3018 xlog_grant_add_space(log, &log->l_reserve_head.grant,
3019 ticket->t_unit_res);
3020 trace_xfs_log_ticket_regrant_exit(log, ticket);
3021
3022 ticket->t_curr_res = ticket->t_unit_res;
3023 }
3024
3025 xfs_log_ticket_put(ticket);
3026}
3027
3028/*
3029 * Give back the space left from a reservation.
3030 *
3031 * All the information we need to make a correct determination of space left
3032 * is present. For non-permanent reservations, things are quite easy. The
3033 * count should have been decremented to zero. We only need to deal with the
3034 * space remaining in the current reservation part of the ticket. If the
3035 * ticket contains a permanent reservation, there may be left over space which
3036 * needs to be released. A count of N means that N-1 refills of the current
3037 * reservation can be done before we need to ask for more space. The first
3038 * one goes to fill up the first current reservation. Once we run out of
3039 * space, the count will stay at zero and the only space remaining will be
3040 * in the current reservation field.
3041 */
3042void
3043xfs_log_ticket_ungrant(
3044 struct xlog *log,
3045 struct xlog_ticket *ticket)
3046{
3047 int bytes;
3048
3049 trace_xfs_log_ticket_ungrant(log, ticket);
3050
3051 if (ticket->t_cnt > 0)
3052 ticket->t_cnt--;
3053
3054 trace_xfs_log_ticket_ungrant_sub(log, ticket);
3055
3056 /*
3057 * If this is a permanent reservation ticket, we may be able to free
3058 * up more space based on the remaining count.
3059 */
3060 bytes = ticket->t_curr_res;
3061 if (ticket->t_cnt > 0) {
3062 ASSERT(ticket->t_flags & XLOG_TIC_PERM_RESERV);
3063 bytes += ticket->t_unit_res*ticket->t_cnt;
3064 }
3065
3066 xlog_grant_sub_space(log, &log->l_reserve_head.grant, bytes);
3067 xlog_grant_sub_space(log, &log->l_write_head.grant, bytes);
3068
3069 trace_xfs_log_ticket_ungrant_exit(log, ticket);
3070
3071 xfs_log_space_wake(log->l_mp);
3072 xfs_log_ticket_put(ticket);
3073}
3074
3075/*
3076 * This routine will mark the current iclog in the ring as WANT_SYNC and move
3077 * the current iclog pointer to the next iclog in the ring.
3078 */
3079void
3080xlog_state_switch_iclogs(
3081 struct xlog *log,
3082 struct xlog_in_core *iclog,
3083 int eventual_size)
3084{
3085 ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE);
3086 assert_spin_locked(&log->l_icloglock);
3087 trace_xlog_iclog_switch(iclog, _RET_IP_);
3088
3089 if (!eventual_size)
3090 eventual_size = iclog->ic_offset;
3091 iclog->ic_state = XLOG_STATE_WANT_SYNC;
3092 iclog->ic_header.h_prev_block = cpu_to_be32(log->l_prev_block);
3093 log->l_prev_block = log->l_curr_block;
3094 log->l_prev_cycle = log->l_curr_cycle;
3095
3096 /* roll log?: ic_offset changed later */
3097 log->l_curr_block += BTOBB(eventual_size)+BTOBB(log->l_iclog_hsize);
3098
3099 /* Round up to next log-sunit */
3100 if (log->l_iclog_roundoff > BBSIZE) {
3101 uint32_t sunit_bb = BTOBB(log->l_iclog_roundoff);
3102 log->l_curr_block = roundup(log->l_curr_block, sunit_bb);
3103 }
3104
3105 if (log->l_curr_block >= log->l_logBBsize) {
3106 /*
3107 * Rewind the current block before the cycle is bumped to make
3108 * sure that the combined LSN never transiently moves forward
3109 * when the log wraps to the next cycle. This is to support the
3110 * unlocked sample of these fields from xlog_valid_lsn(). Most
3111 * other cases should acquire l_icloglock.
3112 */
3113 log->l_curr_block -= log->l_logBBsize;
3114 ASSERT(log->l_curr_block >= 0);
3115 smp_wmb();
3116 log->l_curr_cycle++;
3117 if (log->l_curr_cycle == XLOG_HEADER_MAGIC_NUM)
3118 log->l_curr_cycle++;
3119 }
3120 ASSERT(iclog == log->l_iclog);
3121 log->l_iclog = iclog->ic_next;
3122}
3123
3124/*
3125 * Force the iclog to disk and check if the iclog has been completed before
3126 * xlog_force_iclog() returns. This can happen on synchronous (e.g.
3127 * pmem) or fast async storage because we drop the icloglock to issue the IO.
3128 * If completion has already occurred, tell the caller so that it can avoid an
3129 * unnecessary wait on the iclog.
3130 */
3131static int
3132xlog_force_and_check_iclog(
3133 struct xlog_in_core *iclog,
3134 bool *completed)
3135{
3136 xfs_lsn_t lsn = be64_to_cpu(iclog->ic_header.h_lsn);
3137 int error;
3138
3139 *completed = false;
3140 error = xlog_force_iclog(iclog);
3141 if (error)
3142 return error;
3143
3144 /*
3145 * If the iclog has already been completed and reused the header LSN
3146 * will have been rewritten by completion
3147 */
3148 if (be64_to_cpu(iclog->ic_header.h_lsn) != lsn)
3149 *completed = true;
3150 return 0;
3151}
3152
3153/*
3154 * Write out all data in the in-core log as of this exact moment in time.
3155 *
3156 * Data may be written to the in-core log during this call. However,
3157 * we don't guarantee this data will be written out. A change from past
3158 * implementation means this routine will *not* write out zero length LRs.
3159 *
3160 * Basically, we try and perform an intelligent scan of the in-core logs.
3161 * If we determine there is no flushable data, we just return. There is no
3162 * flushable data if:
3163 *
3164 * 1. the current iclog is active and has no data; the previous iclog
3165 * is in the active or dirty state.
3166 * 2. the current iclog is drity, and the previous iclog is in the
3167 * active or dirty state.
3168 *
3169 * We may sleep if:
3170 *
3171 * 1. the current iclog is not in the active nor dirty state.
3172 * 2. the current iclog dirty, and the previous iclog is not in the
3173 * active nor dirty state.
3174 * 3. the current iclog is active, and there is another thread writing
3175 * to this particular iclog.
3176 * 4. a) the current iclog is active and has no other writers
3177 * b) when we return from flushing out this iclog, it is still
3178 * not in the active nor dirty state.
3179 */
3180int
3181xfs_log_force(
3182 struct xfs_mount *mp,
3183 uint flags)
3184{
3185 struct xlog *log = mp->m_log;
3186 struct xlog_in_core *iclog;
3187
3188 XFS_STATS_INC(mp, xs_log_force);
3189 trace_xfs_log_force(mp, 0, _RET_IP_);
3190
3191 xlog_cil_force(log);
3192
3193 spin_lock(&log->l_icloglock);
3194 if (xlog_is_shutdown(log))
3195 goto out_error;
3196
3197 iclog = log->l_iclog;
3198 trace_xlog_iclog_force(iclog, _RET_IP_);
3199
3200 if (iclog->ic_state == XLOG_STATE_DIRTY ||
3201 (iclog->ic_state == XLOG_STATE_ACTIVE &&
3202 atomic_read(&iclog->ic_refcnt) == 0 && iclog->ic_offset == 0)) {
3203 /*
3204 * If the head is dirty or (active and empty), then we need to
3205 * look at the previous iclog.
3206 *
3207 * If the previous iclog is active or dirty we are done. There
3208 * is nothing to sync out. Otherwise, we attach ourselves to the
3209 * previous iclog and go to sleep.
3210 */
3211 iclog = iclog->ic_prev;
3212 } else if (iclog->ic_state == XLOG_STATE_ACTIVE) {
3213 if (atomic_read(&iclog->ic_refcnt) == 0) {
3214 /* We have exclusive access to this iclog. */
3215 bool completed;
3216
3217 if (xlog_force_and_check_iclog(iclog, &completed))
3218 goto out_error;
3219
3220 if (completed)
3221 goto out_unlock;
3222 } else {
3223 /*
3224 * Someone else is still writing to this iclog, so we
3225 * need to ensure that when they release the iclog it
3226 * gets synced immediately as we may be waiting on it.
3227 */
3228 xlog_state_switch_iclogs(log, iclog, 0);
3229 }
3230 }
3231
3232 /*
3233 * The iclog we are about to wait on may contain the checkpoint pushed
3234 * by the above xlog_cil_force() call, but it may not have been pushed
3235 * to disk yet. Like the ACTIVE case above, we need to make sure caches
3236 * are flushed when this iclog is written.
3237 */
3238 if (iclog->ic_state == XLOG_STATE_WANT_SYNC)
3239 iclog->ic_flags |= XLOG_ICL_NEED_FLUSH | XLOG_ICL_NEED_FUA;
3240
3241 if (flags & XFS_LOG_SYNC)
3242 return xlog_wait_on_iclog(iclog);
3243out_unlock:
3244 spin_unlock(&log->l_icloglock);
3245 return 0;
3246out_error:
3247 spin_unlock(&log->l_icloglock);
3248 return -EIO;
3249}
3250
3251/*
3252 * Force the log to a specific LSN.
3253 *
3254 * If an iclog with that lsn can be found:
3255 * If it is in the DIRTY state, just return.
3256 * If it is in the ACTIVE state, move the in-core log into the WANT_SYNC
3257 * state and go to sleep or return.
3258 * If it is in any other state, go to sleep or return.
3259 *
3260 * Synchronous forces are implemented with a wait queue. All callers trying
3261 * to force a given lsn to disk must wait on the queue attached to the
3262 * specific in-core log. When given in-core log finally completes its write
3263 * to disk, that thread will wake up all threads waiting on the queue.
3264 */
3265static int
3266xlog_force_lsn(
3267 struct xlog *log,
3268 xfs_lsn_t lsn,
3269 uint flags,
3270 int *log_flushed,
3271 bool already_slept)
3272{
3273 struct xlog_in_core *iclog;
3274 bool completed;
3275
3276 spin_lock(&log->l_icloglock);
3277 if (xlog_is_shutdown(log))
3278 goto out_error;
3279
3280 iclog = log->l_iclog;
3281 while (be64_to_cpu(iclog->ic_header.h_lsn) != lsn) {
3282 trace_xlog_iclog_force_lsn(iclog, _RET_IP_);
3283 iclog = iclog->ic_next;
3284 if (iclog == log->l_iclog)
3285 goto out_unlock;
3286 }
3287
3288 switch (iclog->ic_state) {
3289 case XLOG_STATE_ACTIVE:
3290 /*
3291 * We sleep here if we haven't already slept (e.g. this is the
3292 * first time we've looked at the correct iclog buf) and the
3293 * buffer before us is going to be sync'ed. The reason for this
3294 * is that if we are doing sync transactions here, by waiting
3295 * for the previous I/O to complete, we can allow a few more
3296 * transactions into this iclog before we close it down.
3297 *
3298 * Otherwise, we mark the buffer WANT_SYNC, and bump up the
3299 * refcnt so we can release the log (which drops the ref count).
3300 * The state switch keeps new transaction commits from using
3301 * this buffer. When the current commits finish writing into
3302 * the buffer, the refcount will drop to zero and the buffer
3303 * will go out then.
3304 */
3305 if (!already_slept &&
3306 (iclog->ic_prev->ic_state == XLOG_STATE_WANT_SYNC ||
3307 iclog->ic_prev->ic_state == XLOG_STATE_SYNCING)) {
3308 xlog_wait(&iclog->ic_prev->ic_write_wait,
3309 &log->l_icloglock);
3310 return -EAGAIN;
3311 }
3312 if (xlog_force_and_check_iclog(iclog, &completed))
3313 goto out_error;
3314 if (log_flushed)
3315 *log_flushed = 1;
3316 if (completed)
3317 goto out_unlock;
3318 break;
3319 case XLOG_STATE_WANT_SYNC:
3320 /*
3321 * This iclog may contain the checkpoint pushed by the
3322 * xlog_cil_force_seq() call, but there are other writers still
3323 * accessing it so it hasn't been pushed to disk yet. Like the
3324 * ACTIVE case above, we need to make sure caches are flushed
3325 * when this iclog is written.
3326 */
3327 iclog->ic_flags |= XLOG_ICL_NEED_FLUSH | XLOG_ICL_NEED_FUA;
3328 break;
3329 default:
3330 /*
3331 * The entire checkpoint was written by the CIL force and is on
3332 * its way to disk already. It will be stable when it
3333 * completes, so we don't need to manipulate caches here at all.
3334 * We just need to wait for completion if necessary.
3335 */
3336 break;
3337 }
3338
3339 if (flags & XFS_LOG_SYNC)
3340 return xlog_wait_on_iclog(iclog);
3341out_unlock:
3342 spin_unlock(&log->l_icloglock);
3343 return 0;
3344out_error:
3345 spin_unlock(&log->l_icloglock);
3346 return -EIO;
3347}
3348
3349/*
3350 * Force the log to a specific checkpoint sequence.
3351 *
3352 * First force the CIL so that all the required changes have been flushed to the
3353 * iclogs. If the CIL force completed it will return a commit LSN that indicates
3354 * the iclog that needs to be flushed to stable storage. If the caller needs
3355 * a synchronous log force, we will wait on the iclog with the LSN returned by
3356 * xlog_cil_force_seq() to be completed.
3357 */
3358int
3359xfs_log_force_seq(
3360 struct xfs_mount *mp,
3361 xfs_csn_t seq,
3362 uint flags,
3363 int *log_flushed)
3364{
3365 struct xlog *log = mp->m_log;
3366 xfs_lsn_t lsn;
3367 int ret;
3368 ASSERT(seq != 0);
3369
3370 XFS_STATS_INC(mp, xs_log_force);
3371 trace_xfs_log_force(mp, seq, _RET_IP_);
3372
3373 lsn = xlog_cil_force_seq(log, seq);
3374 if (lsn == NULLCOMMITLSN)
3375 return 0;
3376
3377 ret = xlog_force_lsn(log, lsn, flags, log_flushed, false);
3378 if (ret == -EAGAIN) {
3379 XFS_STATS_INC(mp, xs_log_force_sleep);
3380 ret = xlog_force_lsn(log, lsn, flags, log_flushed, true);
3381 }
3382 return ret;
3383}
3384
3385/*
3386 * Free a used ticket when its refcount falls to zero.
3387 */
3388void
3389xfs_log_ticket_put(
3390 xlog_ticket_t *ticket)
3391{
3392 ASSERT(atomic_read(&ticket->t_ref) > 0);
3393 if (atomic_dec_and_test(&ticket->t_ref))
3394 kmem_cache_free(xfs_log_ticket_cache, ticket);
3395}
3396
3397xlog_ticket_t *
3398xfs_log_ticket_get(
3399 xlog_ticket_t *ticket)
3400{
3401 ASSERT(atomic_read(&ticket->t_ref) > 0);
3402 atomic_inc(&ticket->t_ref);
3403 return ticket;
3404}
3405
3406/*
3407 * Figure out the total log space unit (in bytes) that would be
3408 * required for a log ticket.
3409 */
3410static int
3411xlog_calc_unit_res(
3412 struct xlog *log,
3413 int unit_bytes,
3414 int *niclogs)
3415{
3416 int iclog_space;
3417 uint num_headers;
3418
3419 /*
3420 * Permanent reservations have up to 'cnt'-1 active log operations
3421 * in the log. A unit in this case is the amount of space for one
3422 * of these log operations. Normal reservations have a cnt of 1
3423 * and their unit amount is the total amount of space required.
3424 *
3425 * The following lines of code account for non-transaction data
3426 * which occupy space in the on-disk log.
3427 *
3428 * Normal form of a transaction is:
3429 * <oph><trans-hdr><start-oph><reg1-oph><reg1><reg2-oph>...<commit-oph>
3430 * and then there are LR hdrs, split-recs and roundoff at end of syncs.
3431 *
3432 * We need to account for all the leadup data and trailer data
3433 * around the transaction data.
3434 * And then we need to account for the worst case in terms of using
3435 * more space.
3436 * The worst case will happen if:
3437 * - the placement of the transaction happens to be such that the
3438 * roundoff is at its maximum
3439 * - the transaction data is synced before the commit record is synced
3440 * i.e. <transaction-data><roundoff> | <commit-rec><roundoff>
3441 * Therefore the commit record is in its own Log Record.
3442 * This can happen as the commit record is called with its
3443 * own region to xlog_write().
3444 * This then means that in the worst case, roundoff can happen for
3445 * the commit-rec as well.
3446 * The commit-rec is smaller than padding in this scenario and so it is
3447 * not added separately.
3448 */
3449
3450 /* for trans header */
3451 unit_bytes += sizeof(xlog_op_header_t);
3452 unit_bytes += sizeof(xfs_trans_header_t);
3453
3454 /* for start-rec */
3455 unit_bytes += sizeof(xlog_op_header_t);
3456
3457 /*
3458 * for LR headers - the space for data in an iclog is the size minus
3459 * the space used for the headers. If we use the iclog size, then we
3460 * undercalculate the number of headers required.
3461 *
3462 * Furthermore - the addition of op headers for split-recs might
3463 * increase the space required enough to require more log and op
3464 * headers, so take that into account too.
3465 *
3466 * IMPORTANT: This reservation makes the assumption that if this
3467 * transaction is the first in an iclog and hence has the LR headers
3468 * accounted to it, then the remaining space in the iclog is
3469 * exclusively for this transaction. i.e. if the transaction is larger
3470 * than the iclog, it will be the only thing in that iclog.
3471 * Fundamentally, this means we must pass the entire log vector to
3472 * xlog_write to guarantee this.
3473 */
3474 iclog_space = log->l_iclog_size - log->l_iclog_hsize;
3475 num_headers = howmany(unit_bytes, iclog_space);
3476
3477 /* for split-recs - ophdrs added when data split over LRs */
3478 unit_bytes += sizeof(xlog_op_header_t) * num_headers;
3479
3480 /* add extra header reservations if we overrun */
3481 while (!num_headers ||
3482 howmany(unit_bytes, iclog_space) > num_headers) {
3483 unit_bytes += sizeof(xlog_op_header_t);
3484 num_headers++;
3485 }
3486 unit_bytes += log->l_iclog_hsize * num_headers;
3487
3488 /* for commit-rec LR header - note: padding will subsume the ophdr */
3489 unit_bytes += log->l_iclog_hsize;
3490
3491 /* roundoff padding for transaction data and one for commit record */
3492 unit_bytes += 2 * log->l_iclog_roundoff;
3493
3494 if (niclogs)
3495 *niclogs = num_headers;
3496 return unit_bytes;
3497}
3498
3499int
3500xfs_log_calc_unit_res(
3501 struct xfs_mount *mp,
3502 int unit_bytes)
3503{
3504 return xlog_calc_unit_res(mp->m_log, unit_bytes, NULL);
3505}
3506
3507/*
3508 * Allocate and initialise a new log ticket.
3509 */
3510struct xlog_ticket *
3511xlog_ticket_alloc(
3512 struct xlog *log,
3513 int unit_bytes,
3514 int cnt,
3515 bool permanent)
3516{
3517 struct xlog_ticket *tic;
3518 int unit_res;
3519
3520 tic = kmem_cache_zalloc(xfs_log_ticket_cache, GFP_NOFS | __GFP_NOFAIL);
3521
3522 unit_res = xlog_calc_unit_res(log, unit_bytes, &tic->t_iclog_hdrs);
3523
3524 atomic_set(&tic->t_ref, 1);
3525 tic->t_task = current;
3526 INIT_LIST_HEAD(&tic->t_queue);
3527 tic->t_unit_res = unit_res;
3528 tic->t_curr_res = unit_res;
3529 tic->t_cnt = cnt;
3530 tic->t_ocnt = cnt;
3531 tic->t_tid = get_random_u32();
3532 if (permanent)
3533 tic->t_flags |= XLOG_TIC_PERM_RESERV;
3534
3535 return tic;
3536}
3537
3538#if defined(DEBUG)
3539/*
3540 * Check to make sure the grant write head didn't just over lap the tail. If
3541 * the cycles are the same, we can't be overlapping. Otherwise, make sure that
3542 * the cycles differ by exactly one and check the byte count.
3543 *
3544 * This check is run unlocked, so can give false positives. Rather than assert
3545 * on failures, use a warn-once flag and a panic tag to allow the admin to
3546 * determine if they want to panic the machine when such an error occurs. For
3547 * debug kernels this will have the same effect as using an assert but, unlinke
3548 * an assert, it can be turned off at runtime.
3549 */
3550STATIC void
3551xlog_verify_grant_tail(
3552 struct xlog *log)
3553{
3554 int tail_cycle, tail_blocks;
3555 int cycle, space;
3556
3557 xlog_crack_grant_head(&log->l_write_head.grant, &cycle, &space);
3558 xlog_crack_atomic_lsn(&log->l_tail_lsn, &tail_cycle, &tail_blocks);
3559 if (tail_cycle != cycle) {
3560 if (cycle - 1 != tail_cycle &&
3561 !test_and_set_bit(XLOG_TAIL_WARN, &log->l_opstate)) {
3562 xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES,
3563 "%s: cycle - 1 != tail_cycle", __func__);
3564 }
3565
3566 if (space > BBTOB(tail_blocks) &&
3567 !test_and_set_bit(XLOG_TAIL_WARN, &log->l_opstate)) {
3568 xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES,
3569 "%s: space > BBTOB(tail_blocks)", __func__);
3570 }
3571 }
3572}
3573
3574/* check if it will fit */
3575STATIC void
3576xlog_verify_tail_lsn(
3577 struct xlog *log,
3578 struct xlog_in_core *iclog)
3579{
3580 xfs_lsn_t tail_lsn = be64_to_cpu(iclog->ic_header.h_tail_lsn);
3581 int blocks;
3582
3583 if (CYCLE_LSN(tail_lsn) == log->l_prev_cycle) {
3584 blocks =
3585 log->l_logBBsize - (log->l_prev_block - BLOCK_LSN(tail_lsn));
3586 if (blocks < BTOBB(iclog->ic_offset)+BTOBB(log->l_iclog_hsize))
3587 xfs_emerg(log->l_mp, "%s: ran out of log space", __func__);
3588 } else {
3589 ASSERT(CYCLE_LSN(tail_lsn)+1 == log->l_prev_cycle);
3590
3591 if (BLOCK_LSN(tail_lsn) == log->l_prev_block)
3592 xfs_emerg(log->l_mp, "%s: tail wrapped", __func__);
3593
3594 blocks = BLOCK_LSN(tail_lsn) - log->l_prev_block;
3595 if (blocks < BTOBB(iclog->ic_offset) + 1)
3596 xfs_emerg(log->l_mp, "%s: ran out of log space", __func__);
3597 }
3598}
3599
3600/*
3601 * Perform a number of checks on the iclog before writing to disk.
3602 *
3603 * 1. Make sure the iclogs are still circular
3604 * 2. Make sure we have a good magic number
3605 * 3. Make sure we don't have magic numbers in the data
3606 * 4. Check fields of each log operation header for:
3607 * A. Valid client identifier
3608 * B. tid ptr value falls in valid ptr space (user space code)
3609 * C. Length in log record header is correct according to the
3610 * individual operation headers within record.
3611 * 5. When a bwrite will occur within 5 blocks of the front of the physical
3612 * log, check the preceding blocks of the physical log to make sure all
3613 * the cycle numbers agree with the current cycle number.
3614 */
3615STATIC void
3616xlog_verify_iclog(
3617 struct xlog *log,
3618 struct xlog_in_core *iclog,
3619 int count)
3620{
3621 xlog_op_header_t *ophead;
3622 xlog_in_core_t *icptr;
3623 xlog_in_core_2_t *xhdr;
3624 void *base_ptr, *ptr, *p;
3625 ptrdiff_t field_offset;
3626 uint8_t clientid;
3627 int len, i, j, k, op_len;
3628 int idx;
3629
3630 /* check validity of iclog pointers */
3631 spin_lock(&log->l_icloglock);
3632 icptr = log->l_iclog;
3633 for (i = 0; i < log->l_iclog_bufs; i++, icptr = icptr->ic_next)
3634 ASSERT(icptr);
3635
3636 if (icptr != log->l_iclog)
3637 xfs_emerg(log->l_mp, "%s: corrupt iclog ring", __func__);
3638 spin_unlock(&log->l_icloglock);
3639
3640 /* check log magic numbers */
3641 if (iclog->ic_header.h_magicno != cpu_to_be32(XLOG_HEADER_MAGIC_NUM))
3642 xfs_emerg(log->l_mp, "%s: invalid magic num", __func__);
3643
3644 base_ptr = ptr = &iclog->ic_header;
3645 p = &iclog->ic_header;
3646 for (ptr += BBSIZE; ptr < base_ptr + count; ptr += BBSIZE) {
3647 if (*(__be32 *)ptr == cpu_to_be32(XLOG_HEADER_MAGIC_NUM))
3648 xfs_emerg(log->l_mp, "%s: unexpected magic num",
3649 __func__);
3650 }
3651
3652 /* check fields */
3653 len = be32_to_cpu(iclog->ic_header.h_num_logops);
3654 base_ptr = ptr = iclog->ic_datap;
3655 ophead = ptr;
3656 xhdr = iclog->ic_data;
3657 for (i = 0; i < len; i++) {
3658 ophead = ptr;
3659
3660 /* clientid is only 1 byte */
3661 p = &ophead->oh_clientid;
3662 field_offset = p - base_ptr;
3663 if (field_offset & 0x1ff) {
3664 clientid = ophead->oh_clientid;
3665 } else {
3666 idx = BTOBBT((void *)&ophead->oh_clientid - iclog->ic_datap);
3667 if (idx >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE)) {
3668 j = idx / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3669 k = idx % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3670 clientid = xlog_get_client_id(
3671 xhdr[j].hic_xheader.xh_cycle_data[k]);
3672 } else {
3673 clientid = xlog_get_client_id(
3674 iclog->ic_header.h_cycle_data[idx]);
3675 }
3676 }
3677 if (clientid != XFS_TRANSACTION && clientid != XFS_LOG) {
3678 xfs_warn(log->l_mp,
3679 "%s: op %d invalid clientid %d op "PTR_FMT" offset 0x%lx",
3680 __func__, i, clientid, ophead,
3681 (unsigned long)field_offset);
3682 }
3683
3684 /* check length */
3685 p = &ophead->oh_len;
3686 field_offset = p - base_ptr;
3687 if (field_offset & 0x1ff) {
3688 op_len = be32_to_cpu(ophead->oh_len);
3689 } else {
3690 idx = BTOBBT((void *)&ophead->oh_len - iclog->ic_datap);
3691 if (idx >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE)) {
3692 j = idx / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3693 k = idx % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3694 op_len = be32_to_cpu(xhdr[j].hic_xheader.xh_cycle_data[k]);
3695 } else {
3696 op_len = be32_to_cpu(iclog->ic_header.h_cycle_data[idx]);
3697 }
3698 }
3699 ptr += sizeof(xlog_op_header_t) + op_len;
3700 }
3701}
3702#endif
3703
3704/*
3705 * Perform a forced shutdown on the log.
3706 *
3707 * This can be called from low level log code to trigger a shutdown, or from the
3708 * high level mount shutdown code when the mount shuts down.
3709 *
3710 * Our main objectives here are to make sure that:
3711 * a. if the shutdown was not due to a log IO error, flush the logs to
3712 * disk. Anything modified after this is ignored.
3713 * b. the log gets atomically marked 'XLOG_IO_ERROR' for all interested
3714 * parties to find out. Nothing new gets queued after this is done.
3715 * c. Tasks sleeping on log reservations, pinned objects and
3716 * other resources get woken up.
3717 * d. The mount is also marked as shut down so that log triggered shutdowns
3718 * still behave the same as if they called xfs_forced_shutdown().
3719 *
3720 * Return true if the shutdown cause was a log IO error and we actually shut the
3721 * log down.
3722 */
3723bool
3724xlog_force_shutdown(
3725 struct xlog *log,
3726 uint32_t shutdown_flags)
3727{
3728 bool log_error = (shutdown_flags & SHUTDOWN_LOG_IO_ERROR);
3729
3730 if (!log)
3731 return false;
3732
3733 /*
3734 * Flush all the completed transactions to disk before marking the log
3735 * being shut down. We need to do this first as shutting down the log
3736 * before the force will prevent the log force from flushing the iclogs
3737 * to disk.
3738 *
3739 * When we are in recovery, there are no transactions to flush, and
3740 * we don't want to touch the log because we don't want to perturb the
3741 * current head/tail for future recovery attempts. Hence we need to
3742 * avoid a log force in this case.
3743 *
3744 * If we are shutting down due to a log IO error, then we must avoid
3745 * trying to write the log as that may just result in more IO errors and
3746 * an endless shutdown/force loop.
3747 */
3748 if (!log_error && !xlog_in_recovery(log))
3749 xfs_log_force(log->l_mp, XFS_LOG_SYNC);
3750
3751 /*
3752 * Atomically set the shutdown state. If the shutdown state is already
3753 * set, there someone else is performing the shutdown and so we are done
3754 * here. This should never happen because we should only ever get called
3755 * once by the first shutdown caller.
3756 *
3757 * Much of the log state machine transitions assume that shutdown state
3758 * cannot change once they hold the log->l_icloglock. Hence we need to
3759 * hold that lock here, even though we use the atomic test_and_set_bit()
3760 * operation to set the shutdown state.
3761 */
3762 spin_lock(&log->l_icloglock);
3763 if (test_and_set_bit(XLOG_IO_ERROR, &log->l_opstate)) {
3764 spin_unlock(&log->l_icloglock);
3765 return false;
3766 }
3767 spin_unlock(&log->l_icloglock);
3768
3769 /*
3770 * If this log shutdown also sets the mount shutdown state, issue a
3771 * shutdown warning message.
3772 */
3773 if (!test_and_set_bit(XFS_OPSTATE_SHUTDOWN, &log->l_mp->m_opstate)) {
3774 xfs_alert_tag(log->l_mp, XFS_PTAG_SHUTDOWN_LOGERROR,
3775"Filesystem has been shut down due to log error (0x%x).",
3776 shutdown_flags);
3777 xfs_alert(log->l_mp,
3778"Please unmount the filesystem and rectify the problem(s).");
3779 if (xfs_error_level >= XFS_ERRLEVEL_HIGH)
3780 xfs_stack_trace();
3781 }
3782
3783 /*
3784 * We don't want anybody waiting for log reservations after this. That
3785 * means we have to wake up everybody queued up on reserveq as well as
3786 * writeq. In addition, we make sure in xlog_{re}grant_log_space that
3787 * we don't enqueue anything once the SHUTDOWN flag is set, and this
3788 * action is protected by the grant locks.
3789 */
3790 xlog_grant_head_wake_all(&log->l_reserve_head);
3791 xlog_grant_head_wake_all(&log->l_write_head);
3792
3793 /*
3794 * Wake up everybody waiting on xfs_log_force. Wake the CIL push first
3795 * as if the log writes were completed. The abort handling in the log
3796 * item committed callback functions will do this again under lock to
3797 * avoid races.
3798 */
3799 spin_lock(&log->l_cilp->xc_push_lock);
3800 wake_up_all(&log->l_cilp->xc_start_wait);
3801 wake_up_all(&log->l_cilp->xc_commit_wait);
3802 spin_unlock(&log->l_cilp->xc_push_lock);
3803
3804 spin_lock(&log->l_icloglock);
3805 xlog_state_shutdown_callbacks(log);
3806 spin_unlock(&log->l_icloglock);
3807
3808 wake_up_var(&log->l_opstate);
3809 return log_error;
3810}
3811
3812STATIC int
3813xlog_iclogs_empty(
3814 struct xlog *log)
3815{
3816 xlog_in_core_t *iclog;
3817
3818 iclog = log->l_iclog;
3819 do {
3820 /* endianness does not matter here, zero is zero in
3821 * any language.
3822 */
3823 if (iclog->ic_header.h_num_logops)
3824 return 0;
3825 iclog = iclog->ic_next;
3826 } while (iclog != log->l_iclog);
3827 return 1;
3828}
3829
3830/*
3831 * Verify that an LSN stamped into a piece of metadata is valid. This is
3832 * intended for use in read verifiers on v5 superblocks.
3833 */
3834bool
3835xfs_log_check_lsn(
3836 struct xfs_mount *mp,
3837 xfs_lsn_t lsn)
3838{
3839 struct xlog *log = mp->m_log;
3840 bool valid;
3841
3842 /*
3843 * norecovery mode skips mount-time log processing and unconditionally
3844 * resets the in-core LSN. We can't validate in this mode, but
3845 * modifications are not allowed anyways so just return true.
3846 */
3847 if (xfs_has_norecovery(mp))
3848 return true;
3849
3850 /*
3851 * Some metadata LSNs are initialized to NULL (e.g., the agfl). This is
3852 * handled by recovery and thus safe to ignore here.
3853 */
3854 if (lsn == NULLCOMMITLSN)
3855 return true;
3856
3857 valid = xlog_valid_lsn(mp->m_log, lsn);
3858
3859 /* warn the user about what's gone wrong before verifier failure */
3860 if (!valid) {
3861 spin_lock(&log->l_icloglock);
3862 xfs_warn(mp,
3863"Corruption warning: Metadata has LSN (%d:%d) ahead of current LSN (%d:%d). "
3864"Please unmount and run xfs_repair (>= v4.3) to resolve.",
3865 CYCLE_LSN(lsn), BLOCK_LSN(lsn),
3866 log->l_curr_cycle, log->l_curr_block);
3867 spin_unlock(&log->l_icloglock);
3868 }
3869
3870 return valid;
3871}
3872
3873/*
3874 * Notify the log that we're about to start using a feature that is protected
3875 * by a log incompat feature flag. This will prevent log covering from
3876 * clearing those flags.
3877 */
3878void
3879xlog_use_incompat_feat(
3880 struct xlog *log)
3881{
3882 down_read(&log->l_incompat_users);
3883}
3884
3885/* Notify the log that we've finished using log incompat features. */
3886void
3887xlog_drop_incompat_feat(
3888 struct xlog *log)
3889{
3890 up_read(&log->l_incompat_users);
3891}
1/*
2 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18#include "xfs.h"
19#include "xfs_fs.h"
20#include "xfs_shared.h"
21#include "xfs_format.h"
22#include "xfs_log_format.h"
23#include "xfs_trans_resv.h"
24#include "xfs_mount.h"
25#include "xfs_error.h"
26#include "xfs_trans.h"
27#include "xfs_trans_priv.h"
28#include "xfs_log.h"
29#include "xfs_log_priv.h"
30#include "xfs_log_recover.h"
31#include "xfs_inode.h"
32#include "xfs_trace.h"
33#include "xfs_fsops.h"
34#include "xfs_cksum.h"
35#include "xfs_sysfs.h"
36#include "xfs_sb.h"
37
38kmem_zone_t *xfs_log_ticket_zone;
39
40/* Local miscellaneous function prototypes */
41STATIC int
42xlog_commit_record(
43 struct xlog *log,
44 struct xlog_ticket *ticket,
45 struct xlog_in_core **iclog,
46 xfs_lsn_t *commitlsnp);
47
48STATIC struct xlog *
49xlog_alloc_log(
50 struct xfs_mount *mp,
51 struct xfs_buftarg *log_target,
52 xfs_daddr_t blk_offset,
53 int num_bblks);
54STATIC int
55xlog_space_left(
56 struct xlog *log,
57 atomic64_t *head);
58STATIC int
59xlog_sync(
60 struct xlog *log,
61 struct xlog_in_core *iclog);
62STATIC void
63xlog_dealloc_log(
64 struct xlog *log);
65
66/* local state machine functions */
67STATIC void xlog_state_done_syncing(xlog_in_core_t *iclog, int);
68STATIC void
69xlog_state_do_callback(
70 struct xlog *log,
71 int aborted,
72 struct xlog_in_core *iclog);
73STATIC int
74xlog_state_get_iclog_space(
75 struct xlog *log,
76 int len,
77 struct xlog_in_core **iclog,
78 struct xlog_ticket *ticket,
79 int *continued_write,
80 int *logoffsetp);
81STATIC int
82xlog_state_release_iclog(
83 struct xlog *log,
84 struct xlog_in_core *iclog);
85STATIC void
86xlog_state_switch_iclogs(
87 struct xlog *log,
88 struct xlog_in_core *iclog,
89 int eventual_size);
90STATIC void
91xlog_state_want_sync(
92 struct xlog *log,
93 struct xlog_in_core *iclog);
94
95STATIC void
96xlog_grant_push_ail(
97 struct xlog *log,
98 int need_bytes);
99STATIC void
100xlog_regrant_reserve_log_space(
101 struct xlog *log,
102 struct xlog_ticket *ticket);
103STATIC void
104xlog_ungrant_log_space(
105 struct xlog *log,
106 struct xlog_ticket *ticket);
107
108#if defined(DEBUG)
109STATIC void
110xlog_verify_dest_ptr(
111 struct xlog *log,
112 void *ptr);
113STATIC void
114xlog_verify_grant_tail(
115 struct xlog *log);
116STATIC void
117xlog_verify_iclog(
118 struct xlog *log,
119 struct xlog_in_core *iclog,
120 int count,
121 bool syncing);
122STATIC void
123xlog_verify_tail_lsn(
124 struct xlog *log,
125 struct xlog_in_core *iclog,
126 xfs_lsn_t tail_lsn);
127#else
128#define xlog_verify_dest_ptr(a,b)
129#define xlog_verify_grant_tail(a)
130#define xlog_verify_iclog(a,b,c,d)
131#define xlog_verify_tail_lsn(a,b,c)
132#endif
133
134STATIC int
135xlog_iclogs_empty(
136 struct xlog *log);
137
138static void
139xlog_grant_sub_space(
140 struct xlog *log,
141 atomic64_t *head,
142 int bytes)
143{
144 int64_t head_val = atomic64_read(head);
145 int64_t new, old;
146
147 do {
148 int cycle, space;
149
150 xlog_crack_grant_head_val(head_val, &cycle, &space);
151
152 space -= bytes;
153 if (space < 0) {
154 space += log->l_logsize;
155 cycle--;
156 }
157
158 old = head_val;
159 new = xlog_assign_grant_head_val(cycle, space);
160 head_val = atomic64_cmpxchg(head, old, new);
161 } while (head_val != old);
162}
163
164static void
165xlog_grant_add_space(
166 struct xlog *log,
167 atomic64_t *head,
168 int bytes)
169{
170 int64_t head_val = atomic64_read(head);
171 int64_t new, old;
172
173 do {
174 int tmp;
175 int cycle, space;
176
177 xlog_crack_grant_head_val(head_val, &cycle, &space);
178
179 tmp = log->l_logsize - space;
180 if (tmp > bytes)
181 space += bytes;
182 else {
183 space = bytes - tmp;
184 cycle++;
185 }
186
187 old = head_val;
188 new = xlog_assign_grant_head_val(cycle, space);
189 head_val = atomic64_cmpxchg(head, old, new);
190 } while (head_val != old);
191}
192
193STATIC void
194xlog_grant_head_init(
195 struct xlog_grant_head *head)
196{
197 xlog_assign_grant_head(&head->grant, 1, 0);
198 INIT_LIST_HEAD(&head->waiters);
199 spin_lock_init(&head->lock);
200}
201
202STATIC void
203xlog_grant_head_wake_all(
204 struct xlog_grant_head *head)
205{
206 struct xlog_ticket *tic;
207
208 spin_lock(&head->lock);
209 list_for_each_entry(tic, &head->waiters, t_queue)
210 wake_up_process(tic->t_task);
211 spin_unlock(&head->lock);
212}
213
214static inline int
215xlog_ticket_reservation(
216 struct xlog *log,
217 struct xlog_grant_head *head,
218 struct xlog_ticket *tic)
219{
220 if (head == &log->l_write_head) {
221 ASSERT(tic->t_flags & XLOG_TIC_PERM_RESERV);
222 return tic->t_unit_res;
223 } else {
224 if (tic->t_flags & XLOG_TIC_PERM_RESERV)
225 return tic->t_unit_res * tic->t_cnt;
226 else
227 return tic->t_unit_res;
228 }
229}
230
231STATIC bool
232xlog_grant_head_wake(
233 struct xlog *log,
234 struct xlog_grant_head *head,
235 int *free_bytes)
236{
237 struct xlog_ticket *tic;
238 int need_bytes;
239
240 list_for_each_entry(tic, &head->waiters, t_queue) {
241 need_bytes = xlog_ticket_reservation(log, head, tic);
242 if (*free_bytes < need_bytes)
243 return false;
244
245 *free_bytes -= need_bytes;
246 trace_xfs_log_grant_wake_up(log, tic);
247 wake_up_process(tic->t_task);
248 }
249
250 return true;
251}
252
253STATIC int
254xlog_grant_head_wait(
255 struct xlog *log,
256 struct xlog_grant_head *head,
257 struct xlog_ticket *tic,
258 int need_bytes) __releases(&head->lock)
259 __acquires(&head->lock)
260{
261 list_add_tail(&tic->t_queue, &head->waiters);
262
263 do {
264 if (XLOG_FORCED_SHUTDOWN(log))
265 goto shutdown;
266 xlog_grant_push_ail(log, need_bytes);
267
268 __set_current_state(TASK_UNINTERRUPTIBLE);
269 spin_unlock(&head->lock);
270
271 XFS_STATS_INC(log->l_mp, xs_sleep_logspace);
272
273 trace_xfs_log_grant_sleep(log, tic);
274 schedule();
275 trace_xfs_log_grant_wake(log, tic);
276
277 spin_lock(&head->lock);
278 if (XLOG_FORCED_SHUTDOWN(log))
279 goto shutdown;
280 } while (xlog_space_left(log, &head->grant) < need_bytes);
281
282 list_del_init(&tic->t_queue);
283 return 0;
284shutdown:
285 list_del_init(&tic->t_queue);
286 return -EIO;
287}
288
289/*
290 * Atomically get the log space required for a log ticket.
291 *
292 * Once a ticket gets put onto head->waiters, it will only return after the
293 * needed reservation is satisfied.
294 *
295 * This function is structured so that it has a lock free fast path. This is
296 * necessary because every new transaction reservation will come through this
297 * path. Hence any lock will be globally hot if we take it unconditionally on
298 * every pass.
299 *
300 * As tickets are only ever moved on and off head->waiters under head->lock, we
301 * only need to take that lock if we are going to add the ticket to the queue
302 * and sleep. We can avoid taking the lock if the ticket was never added to
303 * head->waiters because the t_queue list head will be empty and we hold the
304 * only reference to it so it can safely be checked unlocked.
305 */
306STATIC int
307xlog_grant_head_check(
308 struct xlog *log,
309 struct xlog_grant_head *head,
310 struct xlog_ticket *tic,
311 int *need_bytes)
312{
313 int free_bytes;
314 int error = 0;
315
316 ASSERT(!(log->l_flags & XLOG_ACTIVE_RECOVERY));
317
318 /*
319 * If there are other waiters on the queue then give them a chance at
320 * logspace before us. Wake up the first waiters, if we do not wake
321 * up all the waiters then go to sleep waiting for more free space,
322 * otherwise try to get some space for this transaction.
323 */
324 *need_bytes = xlog_ticket_reservation(log, head, tic);
325 free_bytes = xlog_space_left(log, &head->grant);
326 if (!list_empty_careful(&head->waiters)) {
327 spin_lock(&head->lock);
328 if (!xlog_grant_head_wake(log, head, &free_bytes) ||
329 free_bytes < *need_bytes) {
330 error = xlog_grant_head_wait(log, head, tic,
331 *need_bytes);
332 }
333 spin_unlock(&head->lock);
334 } else if (free_bytes < *need_bytes) {
335 spin_lock(&head->lock);
336 error = xlog_grant_head_wait(log, head, tic, *need_bytes);
337 spin_unlock(&head->lock);
338 }
339
340 return error;
341}
342
343static void
344xlog_tic_reset_res(xlog_ticket_t *tic)
345{
346 tic->t_res_num = 0;
347 tic->t_res_arr_sum = 0;
348 tic->t_res_num_ophdrs = 0;
349}
350
351static void
352xlog_tic_add_region(xlog_ticket_t *tic, uint len, uint type)
353{
354 if (tic->t_res_num == XLOG_TIC_LEN_MAX) {
355 /* add to overflow and start again */
356 tic->t_res_o_flow += tic->t_res_arr_sum;
357 tic->t_res_num = 0;
358 tic->t_res_arr_sum = 0;
359 }
360
361 tic->t_res_arr[tic->t_res_num].r_len = len;
362 tic->t_res_arr[tic->t_res_num].r_type = type;
363 tic->t_res_arr_sum += len;
364 tic->t_res_num++;
365}
366
367/*
368 * Replenish the byte reservation required by moving the grant write head.
369 */
370int
371xfs_log_regrant(
372 struct xfs_mount *mp,
373 struct xlog_ticket *tic)
374{
375 struct xlog *log = mp->m_log;
376 int need_bytes;
377 int error = 0;
378
379 if (XLOG_FORCED_SHUTDOWN(log))
380 return -EIO;
381
382 XFS_STATS_INC(mp, xs_try_logspace);
383
384 /*
385 * This is a new transaction on the ticket, so we need to change the
386 * transaction ID so that the next transaction has a different TID in
387 * the log. Just add one to the existing tid so that we can see chains
388 * of rolling transactions in the log easily.
389 */
390 tic->t_tid++;
391
392 xlog_grant_push_ail(log, tic->t_unit_res);
393
394 tic->t_curr_res = tic->t_unit_res;
395 xlog_tic_reset_res(tic);
396
397 if (tic->t_cnt > 0)
398 return 0;
399
400 trace_xfs_log_regrant(log, tic);
401
402 error = xlog_grant_head_check(log, &log->l_write_head, tic,
403 &need_bytes);
404 if (error)
405 goto out_error;
406
407 xlog_grant_add_space(log, &log->l_write_head.grant, need_bytes);
408 trace_xfs_log_regrant_exit(log, tic);
409 xlog_verify_grant_tail(log);
410 return 0;
411
412out_error:
413 /*
414 * If we are failing, make sure the ticket doesn't have any current
415 * reservations. We don't want to add this back when the ticket/
416 * transaction gets cancelled.
417 */
418 tic->t_curr_res = 0;
419 tic->t_cnt = 0; /* ungrant will give back unit_res * t_cnt. */
420 return error;
421}
422
423/*
424 * Reserve log space and return a ticket corresponding the reservation.
425 *
426 * Each reservation is going to reserve extra space for a log record header.
427 * When writes happen to the on-disk log, we don't subtract the length of the
428 * log record header from any reservation. By wasting space in each
429 * reservation, we prevent over allocation problems.
430 */
431int
432xfs_log_reserve(
433 struct xfs_mount *mp,
434 int unit_bytes,
435 int cnt,
436 struct xlog_ticket **ticp,
437 __uint8_t client,
438 bool permanent)
439{
440 struct xlog *log = mp->m_log;
441 struct xlog_ticket *tic;
442 int need_bytes;
443 int error = 0;
444
445 ASSERT(client == XFS_TRANSACTION || client == XFS_LOG);
446
447 if (XLOG_FORCED_SHUTDOWN(log))
448 return -EIO;
449
450 XFS_STATS_INC(mp, xs_try_logspace);
451
452 ASSERT(*ticp == NULL);
453 tic = xlog_ticket_alloc(log, unit_bytes, cnt, client, permanent,
454 KM_SLEEP | KM_MAYFAIL);
455 if (!tic)
456 return -ENOMEM;
457
458 *ticp = tic;
459
460 xlog_grant_push_ail(log, tic->t_cnt ? tic->t_unit_res * tic->t_cnt
461 : tic->t_unit_res);
462
463 trace_xfs_log_reserve(log, tic);
464
465 error = xlog_grant_head_check(log, &log->l_reserve_head, tic,
466 &need_bytes);
467 if (error)
468 goto out_error;
469
470 xlog_grant_add_space(log, &log->l_reserve_head.grant, need_bytes);
471 xlog_grant_add_space(log, &log->l_write_head.grant, need_bytes);
472 trace_xfs_log_reserve_exit(log, tic);
473 xlog_verify_grant_tail(log);
474 return 0;
475
476out_error:
477 /*
478 * If we are failing, make sure the ticket doesn't have any current
479 * reservations. We don't want to add this back when the ticket/
480 * transaction gets cancelled.
481 */
482 tic->t_curr_res = 0;
483 tic->t_cnt = 0; /* ungrant will give back unit_res * t_cnt. */
484 return error;
485}
486
487
488/*
489 * NOTES:
490 *
491 * 1. currblock field gets updated at startup and after in-core logs
492 * marked as with WANT_SYNC.
493 */
494
495/*
496 * This routine is called when a user of a log manager ticket is done with
497 * the reservation. If the ticket was ever used, then a commit record for
498 * the associated transaction is written out as a log operation header with
499 * no data. The flag XLOG_TIC_INITED is set when the first write occurs with
500 * a given ticket. If the ticket was one with a permanent reservation, then
501 * a few operations are done differently. Permanent reservation tickets by
502 * default don't release the reservation. They just commit the current
503 * transaction with the belief that the reservation is still needed. A flag
504 * must be passed in before permanent reservations are actually released.
505 * When these type of tickets are not released, they need to be set into
506 * the inited state again. By doing this, a start record will be written
507 * out when the next write occurs.
508 */
509xfs_lsn_t
510xfs_log_done(
511 struct xfs_mount *mp,
512 struct xlog_ticket *ticket,
513 struct xlog_in_core **iclog,
514 bool regrant)
515{
516 struct xlog *log = mp->m_log;
517 xfs_lsn_t lsn = 0;
518
519 if (XLOG_FORCED_SHUTDOWN(log) ||
520 /*
521 * If nothing was ever written, don't write out commit record.
522 * If we get an error, just continue and give back the log ticket.
523 */
524 (((ticket->t_flags & XLOG_TIC_INITED) == 0) &&
525 (xlog_commit_record(log, ticket, iclog, &lsn)))) {
526 lsn = (xfs_lsn_t) -1;
527 regrant = false;
528 }
529
530
531 if (!regrant) {
532 trace_xfs_log_done_nonperm(log, ticket);
533
534 /*
535 * Release ticket if not permanent reservation or a specific
536 * request has been made to release a permanent reservation.
537 */
538 xlog_ungrant_log_space(log, ticket);
539 } else {
540 trace_xfs_log_done_perm(log, ticket);
541
542 xlog_regrant_reserve_log_space(log, ticket);
543 /* If this ticket was a permanent reservation and we aren't
544 * trying to release it, reset the inited flags; so next time
545 * we write, a start record will be written out.
546 */
547 ticket->t_flags |= XLOG_TIC_INITED;
548 }
549
550 xfs_log_ticket_put(ticket);
551 return lsn;
552}
553
554/*
555 * Attaches a new iclog I/O completion callback routine during
556 * transaction commit. If the log is in error state, a non-zero
557 * return code is handed back and the caller is responsible for
558 * executing the callback at an appropriate time.
559 */
560int
561xfs_log_notify(
562 struct xfs_mount *mp,
563 struct xlog_in_core *iclog,
564 xfs_log_callback_t *cb)
565{
566 int abortflg;
567
568 spin_lock(&iclog->ic_callback_lock);
569 abortflg = (iclog->ic_state & XLOG_STATE_IOERROR);
570 if (!abortflg) {
571 ASSERT_ALWAYS((iclog->ic_state == XLOG_STATE_ACTIVE) ||
572 (iclog->ic_state == XLOG_STATE_WANT_SYNC));
573 cb->cb_next = NULL;
574 *(iclog->ic_callback_tail) = cb;
575 iclog->ic_callback_tail = &(cb->cb_next);
576 }
577 spin_unlock(&iclog->ic_callback_lock);
578 return abortflg;
579}
580
581int
582xfs_log_release_iclog(
583 struct xfs_mount *mp,
584 struct xlog_in_core *iclog)
585{
586 if (xlog_state_release_iclog(mp->m_log, iclog)) {
587 xfs_force_shutdown(mp, SHUTDOWN_LOG_IO_ERROR);
588 return -EIO;
589 }
590
591 return 0;
592}
593
594/*
595 * Mount a log filesystem
596 *
597 * mp - ubiquitous xfs mount point structure
598 * log_target - buftarg of on-disk log device
599 * blk_offset - Start block # where block size is 512 bytes (BBSIZE)
600 * num_bblocks - Number of BBSIZE blocks in on-disk log
601 *
602 * Return error or zero.
603 */
604int
605xfs_log_mount(
606 xfs_mount_t *mp,
607 xfs_buftarg_t *log_target,
608 xfs_daddr_t blk_offset,
609 int num_bblks)
610{
611 int error = 0;
612 int min_logfsbs;
613
614 if (!(mp->m_flags & XFS_MOUNT_NORECOVERY)) {
615 xfs_notice(mp, "Mounting V%d Filesystem",
616 XFS_SB_VERSION_NUM(&mp->m_sb));
617 } else {
618 xfs_notice(mp,
619"Mounting V%d filesystem in no-recovery mode. Filesystem will be inconsistent.",
620 XFS_SB_VERSION_NUM(&mp->m_sb));
621 ASSERT(mp->m_flags & XFS_MOUNT_RDONLY);
622 }
623
624 mp->m_log = xlog_alloc_log(mp, log_target, blk_offset, num_bblks);
625 if (IS_ERR(mp->m_log)) {
626 error = PTR_ERR(mp->m_log);
627 goto out;
628 }
629
630 /*
631 * Validate the given log space and drop a critical message via syslog
632 * if the log size is too small that would lead to some unexpected
633 * situations in transaction log space reservation stage.
634 *
635 * Note: we can't just reject the mount if the validation fails. This
636 * would mean that people would have to downgrade their kernel just to
637 * remedy the situation as there is no way to grow the log (short of
638 * black magic surgery with xfs_db).
639 *
640 * We can, however, reject mounts for CRC format filesystems, as the
641 * mkfs binary being used to make the filesystem should never create a
642 * filesystem with a log that is too small.
643 */
644 min_logfsbs = xfs_log_calc_minimum_size(mp);
645
646 if (mp->m_sb.sb_logblocks < min_logfsbs) {
647 xfs_warn(mp,
648 "Log size %d blocks too small, minimum size is %d blocks",
649 mp->m_sb.sb_logblocks, min_logfsbs);
650 error = -EINVAL;
651 } else if (mp->m_sb.sb_logblocks > XFS_MAX_LOG_BLOCKS) {
652 xfs_warn(mp,
653 "Log size %d blocks too large, maximum size is %lld blocks",
654 mp->m_sb.sb_logblocks, XFS_MAX_LOG_BLOCKS);
655 error = -EINVAL;
656 } else if (XFS_FSB_TO_B(mp, mp->m_sb.sb_logblocks) > XFS_MAX_LOG_BYTES) {
657 xfs_warn(mp,
658 "log size %lld bytes too large, maximum size is %lld bytes",
659 XFS_FSB_TO_B(mp, mp->m_sb.sb_logblocks),
660 XFS_MAX_LOG_BYTES);
661 error = -EINVAL;
662 }
663 if (error) {
664 if (xfs_sb_version_hascrc(&mp->m_sb)) {
665 xfs_crit(mp, "AAIEEE! Log failed size checks. Abort!");
666 ASSERT(0);
667 goto out_free_log;
668 }
669 xfs_crit(mp, "Log size out of supported range.");
670 xfs_crit(mp,
671"Continuing onwards, but if log hangs are experienced then please report this message in the bug report.");
672 }
673
674 /*
675 * Initialize the AIL now we have a log.
676 */
677 error = xfs_trans_ail_init(mp);
678 if (error) {
679 xfs_warn(mp, "AIL initialisation failed: error %d", error);
680 goto out_free_log;
681 }
682 mp->m_log->l_ailp = mp->m_ail;
683
684 /*
685 * skip log recovery on a norecovery mount. pretend it all
686 * just worked.
687 */
688 if (!(mp->m_flags & XFS_MOUNT_NORECOVERY)) {
689 int readonly = (mp->m_flags & XFS_MOUNT_RDONLY);
690
691 if (readonly)
692 mp->m_flags &= ~XFS_MOUNT_RDONLY;
693
694 error = xlog_recover(mp->m_log);
695
696 if (readonly)
697 mp->m_flags |= XFS_MOUNT_RDONLY;
698 if (error) {
699 xfs_warn(mp, "log mount/recovery failed: error %d",
700 error);
701 xlog_recover_cancel(mp->m_log);
702 goto out_destroy_ail;
703 }
704 }
705
706 error = xfs_sysfs_init(&mp->m_log->l_kobj, &xfs_log_ktype, &mp->m_kobj,
707 "log");
708 if (error)
709 goto out_destroy_ail;
710
711 /* Normal transactions can now occur */
712 mp->m_log->l_flags &= ~XLOG_ACTIVE_RECOVERY;
713
714 /*
715 * Now the log has been fully initialised and we know were our
716 * space grant counters are, we can initialise the permanent ticket
717 * needed for delayed logging to work.
718 */
719 xlog_cil_init_post_recovery(mp->m_log);
720
721 return 0;
722
723out_destroy_ail:
724 xfs_trans_ail_destroy(mp);
725out_free_log:
726 xlog_dealloc_log(mp->m_log);
727out:
728 return error;
729}
730
731/*
732 * Finish the recovery of the file system. This is separate from the
733 * xfs_log_mount() call, because it depends on the code in xfs_mountfs() to read
734 * in the root and real-time bitmap inodes between calling xfs_log_mount() and
735 * here.
736 *
737 * If we finish recovery successfully, start the background log work. If we are
738 * not doing recovery, then we have a RO filesystem and we don't need to start
739 * it.
740 */
741int
742xfs_log_mount_finish(
743 struct xfs_mount *mp)
744{
745 int error = 0;
746
747 if (mp->m_flags & XFS_MOUNT_NORECOVERY) {
748 ASSERT(mp->m_flags & XFS_MOUNT_RDONLY);
749 return 0;
750 }
751
752 error = xlog_recover_finish(mp->m_log);
753 if (!error)
754 xfs_log_work_queue(mp);
755
756 return error;
757}
758
759/*
760 * The mount has failed. Cancel the recovery if it hasn't completed and destroy
761 * the log.
762 */
763int
764xfs_log_mount_cancel(
765 struct xfs_mount *mp)
766{
767 int error;
768
769 error = xlog_recover_cancel(mp->m_log);
770 xfs_log_unmount(mp);
771
772 return error;
773}
774
775/*
776 * Final log writes as part of unmount.
777 *
778 * Mark the filesystem clean as unmount happens. Note that during relocation
779 * this routine needs to be executed as part of source-bag while the
780 * deallocation must not be done until source-end.
781 */
782
783/*
784 * Unmount record used to have a string "Unmount filesystem--" in the
785 * data section where the "Un" was really a magic number (XLOG_UNMOUNT_TYPE).
786 * We just write the magic number now since that particular field isn't
787 * currently architecture converted and "Unmount" is a bit foo.
788 * As far as I know, there weren't any dependencies on the old behaviour.
789 */
790
791static int
792xfs_log_unmount_write(xfs_mount_t *mp)
793{
794 struct xlog *log = mp->m_log;
795 xlog_in_core_t *iclog;
796#ifdef DEBUG
797 xlog_in_core_t *first_iclog;
798#endif
799 xlog_ticket_t *tic = NULL;
800 xfs_lsn_t lsn;
801 int error;
802
803 /*
804 * Don't write out unmount record on read-only mounts.
805 * Or, if we are doing a forced umount (typically because of IO errors).
806 */
807 if (mp->m_flags & XFS_MOUNT_RDONLY)
808 return 0;
809
810 error = _xfs_log_force(mp, XFS_LOG_SYNC, NULL);
811 ASSERT(error || !(XLOG_FORCED_SHUTDOWN(log)));
812
813#ifdef DEBUG
814 first_iclog = iclog = log->l_iclog;
815 do {
816 if (!(iclog->ic_state & XLOG_STATE_IOERROR)) {
817 ASSERT(iclog->ic_state & XLOG_STATE_ACTIVE);
818 ASSERT(iclog->ic_offset == 0);
819 }
820 iclog = iclog->ic_next;
821 } while (iclog != first_iclog);
822#endif
823 if (! (XLOG_FORCED_SHUTDOWN(log))) {
824 error = xfs_log_reserve(mp, 600, 1, &tic, XFS_LOG, 0);
825 if (!error) {
826 /* the data section must be 32 bit size aligned */
827 struct {
828 __uint16_t magic;
829 __uint16_t pad1;
830 __uint32_t pad2; /* may as well make it 64 bits */
831 } magic = {
832 .magic = XLOG_UNMOUNT_TYPE,
833 };
834 struct xfs_log_iovec reg = {
835 .i_addr = &magic,
836 .i_len = sizeof(magic),
837 .i_type = XLOG_REG_TYPE_UNMOUNT,
838 };
839 struct xfs_log_vec vec = {
840 .lv_niovecs = 1,
841 .lv_iovecp = ®,
842 };
843
844 /* remove inited flag, and account for space used */
845 tic->t_flags = 0;
846 tic->t_curr_res -= sizeof(magic);
847 error = xlog_write(log, &vec, tic, &lsn,
848 NULL, XLOG_UNMOUNT_TRANS);
849 /*
850 * At this point, we're umounting anyway,
851 * so there's no point in transitioning log state
852 * to IOERROR. Just continue...
853 */
854 }
855
856 if (error)
857 xfs_alert(mp, "%s: unmount record failed", __func__);
858
859
860 spin_lock(&log->l_icloglock);
861 iclog = log->l_iclog;
862 atomic_inc(&iclog->ic_refcnt);
863 xlog_state_want_sync(log, iclog);
864 spin_unlock(&log->l_icloglock);
865 error = xlog_state_release_iclog(log, iclog);
866
867 spin_lock(&log->l_icloglock);
868 if (!(iclog->ic_state == XLOG_STATE_ACTIVE ||
869 iclog->ic_state == XLOG_STATE_DIRTY)) {
870 if (!XLOG_FORCED_SHUTDOWN(log)) {
871 xlog_wait(&iclog->ic_force_wait,
872 &log->l_icloglock);
873 } else {
874 spin_unlock(&log->l_icloglock);
875 }
876 } else {
877 spin_unlock(&log->l_icloglock);
878 }
879 if (tic) {
880 trace_xfs_log_umount_write(log, tic);
881 xlog_ungrant_log_space(log, tic);
882 xfs_log_ticket_put(tic);
883 }
884 } else {
885 /*
886 * We're already in forced_shutdown mode, couldn't
887 * even attempt to write out the unmount transaction.
888 *
889 * Go through the motions of sync'ing and releasing
890 * the iclog, even though no I/O will actually happen,
891 * we need to wait for other log I/Os that may already
892 * be in progress. Do this as a separate section of
893 * code so we'll know if we ever get stuck here that
894 * we're in this odd situation of trying to unmount
895 * a file system that went into forced_shutdown as
896 * the result of an unmount..
897 */
898 spin_lock(&log->l_icloglock);
899 iclog = log->l_iclog;
900 atomic_inc(&iclog->ic_refcnt);
901
902 xlog_state_want_sync(log, iclog);
903 spin_unlock(&log->l_icloglock);
904 error = xlog_state_release_iclog(log, iclog);
905
906 spin_lock(&log->l_icloglock);
907
908 if ( ! ( iclog->ic_state == XLOG_STATE_ACTIVE
909 || iclog->ic_state == XLOG_STATE_DIRTY
910 || iclog->ic_state == XLOG_STATE_IOERROR) ) {
911
912 xlog_wait(&iclog->ic_force_wait,
913 &log->l_icloglock);
914 } else {
915 spin_unlock(&log->l_icloglock);
916 }
917 }
918
919 return error;
920} /* xfs_log_unmount_write */
921
922/*
923 * Empty the log for unmount/freeze.
924 *
925 * To do this, we first need to shut down the background log work so it is not
926 * trying to cover the log as we clean up. We then need to unpin all objects in
927 * the log so we can then flush them out. Once they have completed their IO and
928 * run the callbacks removing themselves from the AIL, we can write the unmount
929 * record.
930 */
931void
932xfs_log_quiesce(
933 struct xfs_mount *mp)
934{
935 cancel_delayed_work_sync(&mp->m_log->l_work);
936 xfs_log_force(mp, XFS_LOG_SYNC);
937
938 /*
939 * The superblock buffer is uncached and while xfs_ail_push_all_sync()
940 * will push it, xfs_wait_buftarg() will not wait for it. Further,
941 * xfs_buf_iowait() cannot be used because it was pushed with the
942 * XBF_ASYNC flag set, so we need to use a lock/unlock pair to wait for
943 * the IO to complete.
944 */
945 xfs_ail_push_all_sync(mp->m_ail);
946 xfs_wait_buftarg(mp->m_ddev_targp);
947 xfs_buf_lock(mp->m_sb_bp);
948 xfs_buf_unlock(mp->m_sb_bp);
949
950 xfs_log_unmount_write(mp);
951}
952
953/*
954 * Shut down and release the AIL and Log.
955 *
956 * During unmount, we need to ensure we flush all the dirty metadata objects
957 * from the AIL so that the log is empty before we write the unmount record to
958 * the log. Once this is done, we can tear down the AIL and the log.
959 */
960void
961xfs_log_unmount(
962 struct xfs_mount *mp)
963{
964 xfs_log_quiesce(mp);
965
966 xfs_trans_ail_destroy(mp);
967
968 xfs_sysfs_del(&mp->m_log->l_kobj);
969
970 xlog_dealloc_log(mp->m_log);
971}
972
973void
974xfs_log_item_init(
975 struct xfs_mount *mp,
976 struct xfs_log_item *item,
977 int type,
978 const struct xfs_item_ops *ops)
979{
980 item->li_mountp = mp;
981 item->li_ailp = mp->m_ail;
982 item->li_type = type;
983 item->li_ops = ops;
984 item->li_lv = NULL;
985
986 INIT_LIST_HEAD(&item->li_ail);
987 INIT_LIST_HEAD(&item->li_cil);
988}
989
990/*
991 * Wake up processes waiting for log space after we have moved the log tail.
992 */
993void
994xfs_log_space_wake(
995 struct xfs_mount *mp)
996{
997 struct xlog *log = mp->m_log;
998 int free_bytes;
999
1000 if (XLOG_FORCED_SHUTDOWN(log))
1001 return;
1002
1003 if (!list_empty_careful(&log->l_write_head.waiters)) {
1004 ASSERT(!(log->l_flags & XLOG_ACTIVE_RECOVERY));
1005
1006 spin_lock(&log->l_write_head.lock);
1007 free_bytes = xlog_space_left(log, &log->l_write_head.grant);
1008 xlog_grant_head_wake(log, &log->l_write_head, &free_bytes);
1009 spin_unlock(&log->l_write_head.lock);
1010 }
1011
1012 if (!list_empty_careful(&log->l_reserve_head.waiters)) {
1013 ASSERT(!(log->l_flags & XLOG_ACTIVE_RECOVERY));
1014
1015 spin_lock(&log->l_reserve_head.lock);
1016 free_bytes = xlog_space_left(log, &log->l_reserve_head.grant);
1017 xlog_grant_head_wake(log, &log->l_reserve_head, &free_bytes);
1018 spin_unlock(&log->l_reserve_head.lock);
1019 }
1020}
1021
1022/*
1023 * Determine if we have a transaction that has gone to disk that needs to be
1024 * covered. To begin the transition to the idle state firstly the log needs to
1025 * be idle. That means the CIL, the AIL and the iclogs needs to be empty before
1026 * we start attempting to cover the log.
1027 *
1028 * Only if we are then in a state where covering is needed, the caller is
1029 * informed that dummy transactions are required to move the log into the idle
1030 * state.
1031 *
1032 * If there are any items in the AIl or CIL, then we do not want to attempt to
1033 * cover the log as we may be in a situation where there isn't log space
1034 * available to run a dummy transaction and this can lead to deadlocks when the
1035 * tail of the log is pinned by an item that is modified in the CIL. Hence
1036 * there's no point in running a dummy transaction at this point because we
1037 * can't start trying to idle the log until both the CIL and AIL are empty.
1038 */
1039static int
1040xfs_log_need_covered(xfs_mount_t *mp)
1041{
1042 struct xlog *log = mp->m_log;
1043 int needed = 0;
1044
1045 if (!xfs_fs_writable(mp, SB_FREEZE_WRITE))
1046 return 0;
1047
1048 if (!xlog_cil_empty(log))
1049 return 0;
1050
1051 spin_lock(&log->l_icloglock);
1052 switch (log->l_covered_state) {
1053 case XLOG_STATE_COVER_DONE:
1054 case XLOG_STATE_COVER_DONE2:
1055 case XLOG_STATE_COVER_IDLE:
1056 break;
1057 case XLOG_STATE_COVER_NEED:
1058 case XLOG_STATE_COVER_NEED2:
1059 if (xfs_ail_min_lsn(log->l_ailp))
1060 break;
1061 if (!xlog_iclogs_empty(log))
1062 break;
1063
1064 needed = 1;
1065 if (log->l_covered_state == XLOG_STATE_COVER_NEED)
1066 log->l_covered_state = XLOG_STATE_COVER_DONE;
1067 else
1068 log->l_covered_state = XLOG_STATE_COVER_DONE2;
1069 break;
1070 default:
1071 needed = 1;
1072 break;
1073 }
1074 spin_unlock(&log->l_icloglock);
1075 return needed;
1076}
1077
1078/*
1079 * We may be holding the log iclog lock upon entering this routine.
1080 */
1081xfs_lsn_t
1082xlog_assign_tail_lsn_locked(
1083 struct xfs_mount *mp)
1084{
1085 struct xlog *log = mp->m_log;
1086 struct xfs_log_item *lip;
1087 xfs_lsn_t tail_lsn;
1088
1089 assert_spin_locked(&mp->m_ail->xa_lock);
1090
1091 /*
1092 * To make sure we always have a valid LSN for the log tail we keep
1093 * track of the last LSN which was committed in log->l_last_sync_lsn,
1094 * and use that when the AIL was empty.
1095 */
1096 lip = xfs_ail_min(mp->m_ail);
1097 if (lip)
1098 tail_lsn = lip->li_lsn;
1099 else
1100 tail_lsn = atomic64_read(&log->l_last_sync_lsn);
1101 trace_xfs_log_assign_tail_lsn(log, tail_lsn);
1102 atomic64_set(&log->l_tail_lsn, tail_lsn);
1103 return tail_lsn;
1104}
1105
1106xfs_lsn_t
1107xlog_assign_tail_lsn(
1108 struct xfs_mount *mp)
1109{
1110 xfs_lsn_t tail_lsn;
1111
1112 spin_lock(&mp->m_ail->xa_lock);
1113 tail_lsn = xlog_assign_tail_lsn_locked(mp);
1114 spin_unlock(&mp->m_ail->xa_lock);
1115
1116 return tail_lsn;
1117}
1118
1119/*
1120 * Return the space in the log between the tail and the head. The head
1121 * is passed in the cycle/bytes formal parms. In the special case where
1122 * the reserve head has wrapped passed the tail, this calculation is no
1123 * longer valid. In this case, just return 0 which means there is no space
1124 * in the log. This works for all places where this function is called
1125 * with the reserve head. Of course, if the write head were to ever
1126 * wrap the tail, we should blow up. Rather than catch this case here,
1127 * we depend on other ASSERTions in other parts of the code. XXXmiken
1128 *
1129 * This code also handles the case where the reservation head is behind
1130 * the tail. The details of this case are described below, but the end
1131 * result is that we return the size of the log as the amount of space left.
1132 */
1133STATIC int
1134xlog_space_left(
1135 struct xlog *log,
1136 atomic64_t *head)
1137{
1138 int free_bytes;
1139 int tail_bytes;
1140 int tail_cycle;
1141 int head_cycle;
1142 int head_bytes;
1143
1144 xlog_crack_grant_head(head, &head_cycle, &head_bytes);
1145 xlog_crack_atomic_lsn(&log->l_tail_lsn, &tail_cycle, &tail_bytes);
1146 tail_bytes = BBTOB(tail_bytes);
1147 if (tail_cycle == head_cycle && head_bytes >= tail_bytes)
1148 free_bytes = log->l_logsize - (head_bytes - tail_bytes);
1149 else if (tail_cycle + 1 < head_cycle)
1150 return 0;
1151 else if (tail_cycle < head_cycle) {
1152 ASSERT(tail_cycle == (head_cycle - 1));
1153 free_bytes = tail_bytes - head_bytes;
1154 } else {
1155 /*
1156 * The reservation head is behind the tail.
1157 * In this case we just want to return the size of the
1158 * log as the amount of space left.
1159 */
1160 xfs_alert(log->l_mp, "xlog_space_left: head behind tail");
1161 xfs_alert(log->l_mp,
1162 " tail_cycle = %d, tail_bytes = %d",
1163 tail_cycle, tail_bytes);
1164 xfs_alert(log->l_mp,
1165 " GH cycle = %d, GH bytes = %d",
1166 head_cycle, head_bytes);
1167 ASSERT(0);
1168 free_bytes = log->l_logsize;
1169 }
1170 return free_bytes;
1171}
1172
1173
1174/*
1175 * Log function which is called when an io completes.
1176 *
1177 * The log manager needs its own routine, in order to control what
1178 * happens with the buffer after the write completes.
1179 */
1180static void
1181xlog_iodone(xfs_buf_t *bp)
1182{
1183 struct xlog_in_core *iclog = bp->b_fspriv;
1184 struct xlog *l = iclog->ic_log;
1185 int aborted = 0;
1186
1187 /*
1188 * Race to shutdown the filesystem if we see an error or the iclog is in
1189 * IOABORT state. The IOABORT state is only set in DEBUG mode to inject
1190 * CRC errors into log recovery.
1191 */
1192 if (XFS_TEST_ERROR(bp->b_error, l->l_mp, XFS_ERRTAG_IODONE_IOERR,
1193 XFS_RANDOM_IODONE_IOERR) ||
1194 iclog->ic_state & XLOG_STATE_IOABORT) {
1195 if (iclog->ic_state & XLOG_STATE_IOABORT)
1196 iclog->ic_state &= ~XLOG_STATE_IOABORT;
1197
1198 xfs_buf_ioerror_alert(bp, __func__);
1199 xfs_buf_stale(bp);
1200 xfs_force_shutdown(l->l_mp, SHUTDOWN_LOG_IO_ERROR);
1201 /*
1202 * This flag will be propagated to the trans-committed
1203 * callback routines to let them know that the log-commit
1204 * didn't succeed.
1205 */
1206 aborted = XFS_LI_ABORTED;
1207 } else if (iclog->ic_state & XLOG_STATE_IOERROR) {
1208 aborted = XFS_LI_ABORTED;
1209 }
1210
1211 /* log I/O is always issued ASYNC */
1212 ASSERT(bp->b_flags & XBF_ASYNC);
1213 xlog_state_done_syncing(iclog, aborted);
1214
1215 /*
1216 * drop the buffer lock now that we are done. Nothing references
1217 * the buffer after this, so an unmount waiting on this lock can now
1218 * tear it down safely. As such, it is unsafe to reference the buffer
1219 * (bp) after the unlock as we could race with it being freed.
1220 */
1221 xfs_buf_unlock(bp);
1222}
1223
1224/*
1225 * Return size of each in-core log record buffer.
1226 *
1227 * All machines get 8 x 32kB buffers by default, unless tuned otherwise.
1228 *
1229 * If the filesystem blocksize is too large, we may need to choose a
1230 * larger size since the directory code currently logs entire blocks.
1231 */
1232
1233STATIC void
1234xlog_get_iclog_buffer_size(
1235 struct xfs_mount *mp,
1236 struct xlog *log)
1237{
1238 int size;
1239 int xhdrs;
1240
1241 if (mp->m_logbufs <= 0)
1242 log->l_iclog_bufs = XLOG_MAX_ICLOGS;
1243 else
1244 log->l_iclog_bufs = mp->m_logbufs;
1245
1246 /*
1247 * Buffer size passed in from mount system call.
1248 */
1249 if (mp->m_logbsize > 0) {
1250 size = log->l_iclog_size = mp->m_logbsize;
1251 log->l_iclog_size_log = 0;
1252 while (size != 1) {
1253 log->l_iclog_size_log++;
1254 size >>= 1;
1255 }
1256
1257 if (xfs_sb_version_haslogv2(&mp->m_sb)) {
1258 /* # headers = size / 32k
1259 * one header holds cycles from 32k of data
1260 */
1261
1262 xhdrs = mp->m_logbsize / XLOG_HEADER_CYCLE_SIZE;
1263 if (mp->m_logbsize % XLOG_HEADER_CYCLE_SIZE)
1264 xhdrs++;
1265 log->l_iclog_hsize = xhdrs << BBSHIFT;
1266 log->l_iclog_heads = xhdrs;
1267 } else {
1268 ASSERT(mp->m_logbsize <= XLOG_BIG_RECORD_BSIZE);
1269 log->l_iclog_hsize = BBSIZE;
1270 log->l_iclog_heads = 1;
1271 }
1272 goto done;
1273 }
1274
1275 /* All machines use 32kB buffers by default. */
1276 log->l_iclog_size = XLOG_BIG_RECORD_BSIZE;
1277 log->l_iclog_size_log = XLOG_BIG_RECORD_BSHIFT;
1278
1279 /* the default log size is 16k or 32k which is one header sector */
1280 log->l_iclog_hsize = BBSIZE;
1281 log->l_iclog_heads = 1;
1282
1283done:
1284 /* are we being asked to make the sizes selected above visible? */
1285 if (mp->m_logbufs == 0)
1286 mp->m_logbufs = log->l_iclog_bufs;
1287 if (mp->m_logbsize == 0)
1288 mp->m_logbsize = log->l_iclog_size;
1289} /* xlog_get_iclog_buffer_size */
1290
1291
1292void
1293xfs_log_work_queue(
1294 struct xfs_mount *mp)
1295{
1296 queue_delayed_work(mp->m_log_workqueue, &mp->m_log->l_work,
1297 msecs_to_jiffies(xfs_syncd_centisecs * 10));
1298}
1299
1300/*
1301 * Every sync period we need to unpin all items in the AIL and push them to
1302 * disk. If there is nothing dirty, then we might need to cover the log to
1303 * indicate that the filesystem is idle.
1304 */
1305static void
1306xfs_log_worker(
1307 struct work_struct *work)
1308{
1309 struct xlog *log = container_of(to_delayed_work(work),
1310 struct xlog, l_work);
1311 struct xfs_mount *mp = log->l_mp;
1312
1313 /* dgc: errors ignored - not fatal and nowhere to report them */
1314 if (xfs_log_need_covered(mp)) {
1315 /*
1316 * Dump a transaction into the log that contains no real change.
1317 * This is needed to stamp the current tail LSN into the log
1318 * during the covering operation.
1319 *
1320 * We cannot use an inode here for this - that will push dirty
1321 * state back up into the VFS and then periodic inode flushing
1322 * will prevent log covering from making progress. Hence we
1323 * synchronously log the superblock instead to ensure the
1324 * superblock is immediately unpinned and can be written back.
1325 */
1326 xfs_sync_sb(mp, true);
1327 } else
1328 xfs_log_force(mp, 0);
1329
1330 /* start pushing all the metadata that is currently dirty */
1331 xfs_ail_push_all(mp->m_ail);
1332
1333 /* queue us up again */
1334 xfs_log_work_queue(mp);
1335}
1336
1337/*
1338 * This routine initializes some of the log structure for a given mount point.
1339 * Its primary purpose is to fill in enough, so recovery can occur. However,
1340 * some other stuff may be filled in too.
1341 */
1342STATIC struct xlog *
1343xlog_alloc_log(
1344 struct xfs_mount *mp,
1345 struct xfs_buftarg *log_target,
1346 xfs_daddr_t blk_offset,
1347 int num_bblks)
1348{
1349 struct xlog *log;
1350 xlog_rec_header_t *head;
1351 xlog_in_core_t **iclogp;
1352 xlog_in_core_t *iclog, *prev_iclog=NULL;
1353 xfs_buf_t *bp;
1354 int i;
1355 int error = -ENOMEM;
1356 uint log2_size = 0;
1357
1358 log = kmem_zalloc(sizeof(struct xlog), KM_MAYFAIL);
1359 if (!log) {
1360 xfs_warn(mp, "Log allocation failed: No memory!");
1361 goto out;
1362 }
1363
1364 log->l_mp = mp;
1365 log->l_targ = log_target;
1366 log->l_logsize = BBTOB(num_bblks);
1367 log->l_logBBstart = blk_offset;
1368 log->l_logBBsize = num_bblks;
1369 log->l_covered_state = XLOG_STATE_COVER_IDLE;
1370 log->l_flags |= XLOG_ACTIVE_RECOVERY;
1371 INIT_DELAYED_WORK(&log->l_work, xfs_log_worker);
1372
1373 log->l_prev_block = -1;
1374 /* log->l_tail_lsn = 0x100000000LL; cycle = 1; current block = 0 */
1375 xlog_assign_atomic_lsn(&log->l_tail_lsn, 1, 0);
1376 xlog_assign_atomic_lsn(&log->l_last_sync_lsn, 1, 0);
1377 log->l_curr_cycle = 1; /* 0 is bad since this is initial value */
1378
1379 xlog_grant_head_init(&log->l_reserve_head);
1380 xlog_grant_head_init(&log->l_write_head);
1381
1382 error = -EFSCORRUPTED;
1383 if (xfs_sb_version_hassector(&mp->m_sb)) {
1384 log2_size = mp->m_sb.sb_logsectlog;
1385 if (log2_size < BBSHIFT) {
1386 xfs_warn(mp, "Log sector size too small (0x%x < 0x%x)",
1387 log2_size, BBSHIFT);
1388 goto out_free_log;
1389 }
1390
1391 log2_size -= BBSHIFT;
1392 if (log2_size > mp->m_sectbb_log) {
1393 xfs_warn(mp, "Log sector size too large (0x%x > 0x%x)",
1394 log2_size, mp->m_sectbb_log);
1395 goto out_free_log;
1396 }
1397
1398 /* for larger sector sizes, must have v2 or external log */
1399 if (log2_size && log->l_logBBstart > 0 &&
1400 !xfs_sb_version_haslogv2(&mp->m_sb)) {
1401 xfs_warn(mp,
1402 "log sector size (0x%x) invalid for configuration.",
1403 log2_size);
1404 goto out_free_log;
1405 }
1406 }
1407 log->l_sectBBsize = 1 << log2_size;
1408
1409 xlog_get_iclog_buffer_size(mp, log);
1410
1411 /*
1412 * Use a NULL block for the extra log buffer used during splits so that
1413 * it will trigger errors if we ever try to do IO on it without first
1414 * having set it up properly.
1415 */
1416 error = -ENOMEM;
1417 bp = xfs_buf_alloc(mp->m_logdev_targp, XFS_BUF_DADDR_NULL,
1418 BTOBB(log->l_iclog_size), XBF_NO_IOACCT);
1419 if (!bp)
1420 goto out_free_log;
1421
1422 /*
1423 * The iclogbuf buffer locks are held over IO but we are not going to do
1424 * IO yet. Hence unlock the buffer so that the log IO path can grab it
1425 * when appropriately.
1426 */
1427 ASSERT(xfs_buf_islocked(bp));
1428 xfs_buf_unlock(bp);
1429
1430 /* use high priority wq for log I/O completion */
1431 bp->b_ioend_wq = mp->m_log_workqueue;
1432 bp->b_iodone = xlog_iodone;
1433 log->l_xbuf = bp;
1434
1435 spin_lock_init(&log->l_icloglock);
1436 init_waitqueue_head(&log->l_flush_wait);
1437
1438 iclogp = &log->l_iclog;
1439 /*
1440 * The amount of memory to allocate for the iclog structure is
1441 * rather funky due to the way the structure is defined. It is
1442 * done this way so that we can use different sizes for machines
1443 * with different amounts of memory. See the definition of
1444 * xlog_in_core_t in xfs_log_priv.h for details.
1445 */
1446 ASSERT(log->l_iclog_size >= 4096);
1447 for (i=0; i < log->l_iclog_bufs; i++) {
1448 *iclogp = kmem_zalloc(sizeof(xlog_in_core_t), KM_MAYFAIL);
1449 if (!*iclogp)
1450 goto out_free_iclog;
1451
1452 iclog = *iclogp;
1453 iclog->ic_prev = prev_iclog;
1454 prev_iclog = iclog;
1455
1456 bp = xfs_buf_get_uncached(mp->m_logdev_targp,
1457 BTOBB(log->l_iclog_size),
1458 XBF_NO_IOACCT);
1459 if (!bp)
1460 goto out_free_iclog;
1461
1462 ASSERT(xfs_buf_islocked(bp));
1463 xfs_buf_unlock(bp);
1464
1465 /* use high priority wq for log I/O completion */
1466 bp->b_ioend_wq = mp->m_log_workqueue;
1467 bp->b_iodone = xlog_iodone;
1468 iclog->ic_bp = bp;
1469 iclog->ic_data = bp->b_addr;
1470#ifdef DEBUG
1471 log->l_iclog_bak[i] = &iclog->ic_header;
1472#endif
1473 head = &iclog->ic_header;
1474 memset(head, 0, sizeof(xlog_rec_header_t));
1475 head->h_magicno = cpu_to_be32(XLOG_HEADER_MAGIC_NUM);
1476 head->h_version = cpu_to_be32(
1477 xfs_sb_version_haslogv2(&log->l_mp->m_sb) ? 2 : 1);
1478 head->h_size = cpu_to_be32(log->l_iclog_size);
1479 /* new fields */
1480 head->h_fmt = cpu_to_be32(XLOG_FMT);
1481 memcpy(&head->h_fs_uuid, &mp->m_sb.sb_uuid, sizeof(uuid_t));
1482
1483 iclog->ic_size = BBTOB(bp->b_length) - log->l_iclog_hsize;
1484 iclog->ic_state = XLOG_STATE_ACTIVE;
1485 iclog->ic_log = log;
1486 atomic_set(&iclog->ic_refcnt, 0);
1487 spin_lock_init(&iclog->ic_callback_lock);
1488 iclog->ic_callback_tail = &(iclog->ic_callback);
1489 iclog->ic_datap = (char *)iclog->ic_data + log->l_iclog_hsize;
1490
1491 init_waitqueue_head(&iclog->ic_force_wait);
1492 init_waitqueue_head(&iclog->ic_write_wait);
1493
1494 iclogp = &iclog->ic_next;
1495 }
1496 *iclogp = log->l_iclog; /* complete ring */
1497 log->l_iclog->ic_prev = prev_iclog; /* re-write 1st prev ptr */
1498
1499 error = xlog_cil_init(log);
1500 if (error)
1501 goto out_free_iclog;
1502 return log;
1503
1504out_free_iclog:
1505 for (iclog = log->l_iclog; iclog; iclog = prev_iclog) {
1506 prev_iclog = iclog->ic_next;
1507 if (iclog->ic_bp)
1508 xfs_buf_free(iclog->ic_bp);
1509 kmem_free(iclog);
1510 }
1511 spinlock_destroy(&log->l_icloglock);
1512 xfs_buf_free(log->l_xbuf);
1513out_free_log:
1514 kmem_free(log);
1515out:
1516 return ERR_PTR(error);
1517} /* xlog_alloc_log */
1518
1519
1520/*
1521 * Write out the commit record of a transaction associated with the given
1522 * ticket. Return the lsn of the commit record.
1523 */
1524STATIC int
1525xlog_commit_record(
1526 struct xlog *log,
1527 struct xlog_ticket *ticket,
1528 struct xlog_in_core **iclog,
1529 xfs_lsn_t *commitlsnp)
1530{
1531 struct xfs_mount *mp = log->l_mp;
1532 int error;
1533 struct xfs_log_iovec reg = {
1534 .i_addr = NULL,
1535 .i_len = 0,
1536 .i_type = XLOG_REG_TYPE_COMMIT,
1537 };
1538 struct xfs_log_vec vec = {
1539 .lv_niovecs = 1,
1540 .lv_iovecp = ®,
1541 };
1542
1543 ASSERT_ALWAYS(iclog);
1544 error = xlog_write(log, &vec, ticket, commitlsnp, iclog,
1545 XLOG_COMMIT_TRANS);
1546 if (error)
1547 xfs_force_shutdown(mp, SHUTDOWN_LOG_IO_ERROR);
1548 return error;
1549}
1550
1551/*
1552 * Push on the buffer cache code if we ever use more than 75% of the on-disk
1553 * log space. This code pushes on the lsn which would supposedly free up
1554 * the 25% which we want to leave free. We may need to adopt a policy which
1555 * pushes on an lsn which is further along in the log once we reach the high
1556 * water mark. In this manner, we would be creating a low water mark.
1557 */
1558STATIC void
1559xlog_grant_push_ail(
1560 struct xlog *log,
1561 int need_bytes)
1562{
1563 xfs_lsn_t threshold_lsn = 0;
1564 xfs_lsn_t last_sync_lsn;
1565 int free_blocks;
1566 int free_bytes;
1567 int threshold_block;
1568 int threshold_cycle;
1569 int free_threshold;
1570
1571 ASSERT(BTOBB(need_bytes) < log->l_logBBsize);
1572
1573 free_bytes = xlog_space_left(log, &log->l_reserve_head.grant);
1574 free_blocks = BTOBBT(free_bytes);
1575
1576 /*
1577 * Set the threshold for the minimum number of free blocks in the
1578 * log to the maximum of what the caller needs, one quarter of the
1579 * log, and 256 blocks.
1580 */
1581 free_threshold = BTOBB(need_bytes);
1582 free_threshold = MAX(free_threshold, (log->l_logBBsize >> 2));
1583 free_threshold = MAX(free_threshold, 256);
1584 if (free_blocks >= free_threshold)
1585 return;
1586
1587 xlog_crack_atomic_lsn(&log->l_tail_lsn, &threshold_cycle,
1588 &threshold_block);
1589 threshold_block += free_threshold;
1590 if (threshold_block >= log->l_logBBsize) {
1591 threshold_block -= log->l_logBBsize;
1592 threshold_cycle += 1;
1593 }
1594 threshold_lsn = xlog_assign_lsn(threshold_cycle,
1595 threshold_block);
1596 /*
1597 * Don't pass in an lsn greater than the lsn of the last
1598 * log record known to be on disk. Use a snapshot of the last sync lsn
1599 * so that it doesn't change between the compare and the set.
1600 */
1601 last_sync_lsn = atomic64_read(&log->l_last_sync_lsn);
1602 if (XFS_LSN_CMP(threshold_lsn, last_sync_lsn) > 0)
1603 threshold_lsn = last_sync_lsn;
1604
1605 /*
1606 * Get the transaction layer to kick the dirty buffers out to
1607 * disk asynchronously. No point in trying to do this if
1608 * the filesystem is shutting down.
1609 */
1610 if (!XLOG_FORCED_SHUTDOWN(log))
1611 xfs_ail_push(log->l_ailp, threshold_lsn);
1612}
1613
1614/*
1615 * Stamp cycle number in every block
1616 */
1617STATIC void
1618xlog_pack_data(
1619 struct xlog *log,
1620 struct xlog_in_core *iclog,
1621 int roundoff)
1622{
1623 int i, j, k;
1624 int size = iclog->ic_offset + roundoff;
1625 __be32 cycle_lsn;
1626 char *dp;
1627
1628 cycle_lsn = CYCLE_LSN_DISK(iclog->ic_header.h_lsn);
1629
1630 dp = iclog->ic_datap;
1631 for (i = 0; i < BTOBB(size); i++) {
1632 if (i >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE))
1633 break;
1634 iclog->ic_header.h_cycle_data[i] = *(__be32 *)dp;
1635 *(__be32 *)dp = cycle_lsn;
1636 dp += BBSIZE;
1637 }
1638
1639 if (xfs_sb_version_haslogv2(&log->l_mp->m_sb)) {
1640 xlog_in_core_2_t *xhdr = iclog->ic_data;
1641
1642 for ( ; i < BTOBB(size); i++) {
1643 j = i / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
1644 k = i % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
1645 xhdr[j].hic_xheader.xh_cycle_data[k] = *(__be32 *)dp;
1646 *(__be32 *)dp = cycle_lsn;
1647 dp += BBSIZE;
1648 }
1649
1650 for (i = 1; i < log->l_iclog_heads; i++)
1651 xhdr[i].hic_xheader.xh_cycle = cycle_lsn;
1652 }
1653}
1654
1655/*
1656 * Calculate the checksum for a log buffer.
1657 *
1658 * This is a little more complicated than it should be because the various
1659 * headers and the actual data are non-contiguous.
1660 */
1661__le32
1662xlog_cksum(
1663 struct xlog *log,
1664 struct xlog_rec_header *rhead,
1665 char *dp,
1666 int size)
1667{
1668 __uint32_t crc;
1669
1670 /* first generate the crc for the record header ... */
1671 crc = xfs_start_cksum_update((char *)rhead,
1672 sizeof(struct xlog_rec_header),
1673 offsetof(struct xlog_rec_header, h_crc));
1674
1675 /* ... then for additional cycle data for v2 logs ... */
1676 if (xfs_sb_version_haslogv2(&log->l_mp->m_sb)) {
1677 union xlog_in_core2 *xhdr = (union xlog_in_core2 *)rhead;
1678 int i;
1679 int xheads;
1680
1681 xheads = size / XLOG_HEADER_CYCLE_SIZE;
1682 if (size % XLOG_HEADER_CYCLE_SIZE)
1683 xheads++;
1684
1685 for (i = 1; i < xheads; i++) {
1686 crc = crc32c(crc, &xhdr[i].hic_xheader,
1687 sizeof(struct xlog_rec_ext_header));
1688 }
1689 }
1690
1691 /* ... and finally for the payload */
1692 crc = crc32c(crc, dp, size);
1693
1694 return xfs_end_cksum(crc);
1695}
1696
1697/*
1698 * The bdstrat callback function for log bufs. This gives us a central
1699 * place to trap bufs in case we get hit by a log I/O error and need to
1700 * shutdown. Actually, in practice, even when we didn't get a log error,
1701 * we transition the iclogs to IOERROR state *after* flushing all existing
1702 * iclogs to disk. This is because we don't want anymore new transactions to be
1703 * started or completed afterwards.
1704 *
1705 * We lock the iclogbufs here so that we can serialise against IO completion
1706 * during unmount. We might be processing a shutdown triggered during unmount,
1707 * and that can occur asynchronously to the unmount thread, and hence we need to
1708 * ensure that completes before tearing down the iclogbufs. Hence we need to
1709 * hold the buffer lock across the log IO to acheive that.
1710 */
1711STATIC int
1712xlog_bdstrat(
1713 struct xfs_buf *bp)
1714{
1715 struct xlog_in_core *iclog = bp->b_fspriv;
1716
1717 xfs_buf_lock(bp);
1718 if (iclog->ic_state & XLOG_STATE_IOERROR) {
1719 xfs_buf_ioerror(bp, -EIO);
1720 xfs_buf_stale(bp);
1721 xfs_buf_ioend(bp);
1722 /*
1723 * It would seem logical to return EIO here, but we rely on
1724 * the log state machine to propagate I/O errors instead of
1725 * doing it here. Similarly, IO completion will unlock the
1726 * buffer, so we don't do it here.
1727 */
1728 return 0;
1729 }
1730
1731 xfs_buf_submit(bp);
1732 return 0;
1733}
1734
1735/*
1736 * Flush out the in-core log (iclog) to the on-disk log in an asynchronous
1737 * fashion. Previously, we should have moved the current iclog
1738 * ptr in the log to point to the next available iclog. This allows further
1739 * write to continue while this code syncs out an iclog ready to go.
1740 * Before an in-core log can be written out, the data section must be scanned
1741 * to save away the 1st word of each BBSIZE block into the header. We replace
1742 * it with the current cycle count. Each BBSIZE block is tagged with the
1743 * cycle count because there in an implicit assumption that drives will
1744 * guarantee that entire 512 byte blocks get written at once. In other words,
1745 * we can't have part of a 512 byte block written and part not written. By
1746 * tagging each block, we will know which blocks are valid when recovering
1747 * after an unclean shutdown.
1748 *
1749 * This routine is single threaded on the iclog. No other thread can be in
1750 * this routine with the same iclog. Changing contents of iclog can there-
1751 * fore be done without grabbing the state machine lock. Updating the global
1752 * log will require grabbing the lock though.
1753 *
1754 * The entire log manager uses a logical block numbering scheme. Only
1755 * log_sync (and then only bwrite()) know about the fact that the log may
1756 * not start with block zero on a given device. The log block start offset
1757 * is added immediately before calling bwrite().
1758 */
1759
1760STATIC int
1761xlog_sync(
1762 struct xlog *log,
1763 struct xlog_in_core *iclog)
1764{
1765 xfs_buf_t *bp;
1766 int i;
1767 uint count; /* byte count of bwrite */
1768 uint count_init; /* initial count before roundup */
1769 int roundoff; /* roundoff to BB or stripe */
1770 int split = 0; /* split write into two regions */
1771 int error;
1772 int v2 = xfs_sb_version_haslogv2(&log->l_mp->m_sb);
1773 int size;
1774
1775 XFS_STATS_INC(log->l_mp, xs_log_writes);
1776 ASSERT(atomic_read(&iclog->ic_refcnt) == 0);
1777
1778 /* Add for LR header */
1779 count_init = log->l_iclog_hsize + iclog->ic_offset;
1780
1781 /* Round out the log write size */
1782 if (v2 && log->l_mp->m_sb.sb_logsunit > 1) {
1783 /* we have a v2 stripe unit to use */
1784 count = XLOG_LSUNITTOB(log, XLOG_BTOLSUNIT(log, count_init));
1785 } else {
1786 count = BBTOB(BTOBB(count_init));
1787 }
1788 roundoff = count - count_init;
1789 ASSERT(roundoff >= 0);
1790 ASSERT((v2 && log->l_mp->m_sb.sb_logsunit > 1 &&
1791 roundoff < log->l_mp->m_sb.sb_logsunit)
1792 ||
1793 (log->l_mp->m_sb.sb_logsunit <= 1 &&
1794 roundoff < BBTOB(1)));
1795
1796 /* move grant heads by roundoff in sync */
1797 xlog_grant_add_space(log, &log->l_reserve_head.grant, roundoff);
1798 xlog_grant_add_space(log, &log->l_write_head.grant, roundoff);
1799
1800 /* put cycle number in every block */
1801 xlog_pack_data(log, iclog, roundoff);
1802
1803 /* real byte length */
1804 size = iclog->ic_offset;
1805 if (v2)
1806 size += roundoff;
1807 iclog->ic_header.h_len = cpu_to_be32(size);
1808
1809 bp = iclog->ic_bp;
1810 XFS_BUF_SET_ADDR(bp, BLOCK_LSN(be64_to_cpu(iclog->ic_header.h_lsn)));
1811
1812 XFS_STATS_ADD(log->l_mp, xs_log_blocks, BTOBB(count));
1813
1814 /* Do we need to split this write into 2 parts? */
1815 if (XFS_BUF_ADDR(bp) + BTOBB(count) > log->l_logBBsize) {
1816 char *dptr;
1817
1818 split = count - (BBTOB(log->l_logBBsize - XFS_BUF_ADDR(bp)));
1819 count = BBTOB(log->l_logBBsize - XFS_BUF_ADDR(bp));
1820 iclog->ic_bwritecnt = 2;
1821
1822 /*
1823 * Bump the cycle numbers at the start of each block in the
1824 * part of the iclog that ends up in the buffer that gets
1825 * written to the start of the log.
1826 *
1827 * Watch out for the header magic number case, though.
1828 */
1829 dptr = (char *)&iclog->ic_header + count;
1830 for (i = 0; i < split; i += BBSIZE) {
1831 __uint32_t cycle = be32_to_cpu(*(__be32 *)dptr);
1832 if (++cycle == XLOG_HEADER_MAGIC_NUM)
1833 cycle++;
1834 *(__be32 *)dptr = cpu_to_be32(cycle);
1835
1836 dptr += BBSIZE;
1837 }
1838 } else {
1839 iclog->ic_bwritecnt = 1;
1840 }
1841
1842 /* calculcate the checksum */
1843 iclog->ic_header.h_crc = xlog_cksum(log, &iclog->ic_header,
1844 iclog->ic_datap, size);
1845#ifdef DEBUG
1846 /*
1847 * Intentionally corrupt the log record CRC based on the error injection
1848 * frequency, if defined. This facilitates testing log recovery in the
1849 * event of torn writes. Hence, set the IOABORT state to abort the log
1850 * write on I/O completion and shutdown the fs. The subsequent mount
1851 * detects the bad CRC and attempts to recover.
1852 */
1853 if (log->l_badcrc_factor &&
1854 (prandom_u32() % log->l_badcrc_factor == 0)) {
1855 iclog->ic_header.h_crc &= 0xAAAAAAAA;
1856 iclog->ic_state |= XLOG_STATE_IOABORT;
1857 xfs_warn(log->l_mp,
1858 "Intentionally corrupted log record at LSN 0x%llx. Shutdown imminent.",
1859 be64_to_cpu(iclog->ic_header.h_lsn));
1860 }
1861#endif
1862
1863 bp->b_io_length = BTOBB(count);
1864 bp->b_fspriv = iclog;
1865 bp->b_flags &= ~XBF_FLUSH;
1866 bp->b_flags |= (XBF_ASYNC | XBF_SYNCIO | XBF_WRITE | XBF_FUA);
1867
1868 /*
1869 * Flush the data device before flushing the log to make sure all meta
1870 * data written back from the AIL actually made it to disk before
1871 * stamping the new log tail LSN into the log buffer. For an external
1872 * log we need to issue the flush explicitly, and unfortunately
1873 * synchronously here; for an internal log we can simply use the block
1874 * layer state machine for preflushes.
1875 */
1876 if (log->l_mp->m_logdev_targp != log->l_mp->m_ddev_targp)
1877 xfs_blkdev_issue_flush(log->l_mp->m_ddev_targp);
1878 else
1879 bp->b_flags |= XBF_FLUSH;
1880
1881 ASSERT(XFS_BUF_ADDR(bp) <= log->l_logBBsize-1);
1882 ASSERT(XFS_BUF_ADDR(bp) + BTOBB(count) <= log->l_logBBsize);
1883
1884 xlog_verify_iclog(log, iclog, count, true);
1885
1886 /* account for log which doesn't start at block #0 */
1887 XFS_BUF_SET_ADDR(bp, XFS_BUF_ADDR(bp) + log->l_logBBstart);
1888
1889 /*
1890 * Don't call xfs_bwrite here. We do log-syncs even when the filesystem
1891 * is shutting down.
1892 */
1893 error = xlog_bdstrat(bp);
1894 if (error) {
1895 xfs_buf_ioerror_alert(bp, "xlog_sync");
1896 return error;
1897 }
1898 if (split) {
1899 bp = iclog->ic_log->l_xbuf;
1900 XFS_BUF_SET_ADDR(bp, 0); /* logical 0 */
1901 xfs_buf_associate_memory(bp,
1902 (char *)&iclog->ic_header + count, split);
1903 bp->b_fspriv = iclog;
1904 bp->b_flags &= ~XBF_FLUSH;
1905 bp->b_flags |= (XBF_ASYNC | XBF_SYNCIO | XBF_WRITE | XBF_FUA);
1906
1907 ASSERT(XFS_BUF_ADDR(bp) <= log->l_logBBsize-1);
1908 ASSERT(XFS_BUF_ADDR(bp) + BTOBB(count) <= log->l_logBBsize);
1909
1910 /* account for internal log which doesn't start at block #0 */
1911 XFS_BUF_SET_ADDR(bp, XFS_BUF_ADDR(bp) + log->l_logBBstart);
1912 error = xlog_bdstrat(bp);
1913 if (error) {
1914 xfs_buf_ioerror_alert(bp, "xlog_sync (split)");
1915 return error;
1916 }
1917 }
1918 return 0;
1919} /* xlog_sync */
1920
1921/*
1922 * Deallocate a log structure
1923 */
1924STATIC void
1925xlog_dealloc_log(
1926 struct xlog *log)
1927{
1928 xlog_in_core_t *iclog, *next_iclog;
1929 int i;
1930
1931 xlog_cil_destroy(log);
1932
1933 /*
1934 * Cycle all the iclogbuf locks to make sure all log IO completion
1935 * is done before we tear down these buffers.
1936 */
1937 iclog = log->l_iclog;
1938 for (i = 0; i < log->l_iclog_bufs; i++) {
1939 xfs_buf_lock(iclog->ic_bp);
1940 xfs_buf_unlock(iclog->ic_bp);
1941 iclog = iclog->ic_next;
1942 }
1943
1944 /*
1945 * Always need to ensure that the extra buffer does not point to memory
1946 * owned by another log buffer before we free it. Also, cycle the lock
1947 * first to ensure we've completed IO on it.
1948 */
1949 xfs_buf_lock(log->l_xbuf);
1950 xfs_buf_unlock(log->l_xbuf);
1951 xfs_buf_set_empty(log->l_xbuf, BTOBB(log->l_iclog_size));
1952 xfs_buf_free(log->l_xbuf);
1953
1954 iclog = log->l_iclog;
1955 for (i = 0; i < log->l_iclog_bufs; i++) {
1956 xfs_buf_free(iclog->ic_bp);
1957 next_iclog = iclog->ic_next;
1958 kmem_free(iclog);
1959 iclog = next_iclog;
1960 }
1961 spinlock_destroy(&log->l_icloglock);
1962
1963 log->l_mp->m_log = NULL;
1964 kmem_free(log);
1965} /* xlog_dealloc_log */
1966
1967/*
1968 * Update counters atomically now that memcpy is done.
1969 */
1970/* ARGSUSED */
1971static inline void
1972xlog_state_finish_copy(
1973 struct xlog *log,
1974 struct xlog_in_core *iclog,
1975 int record_cnt,
1976 int copy_bytes)
1977{
1978 spin_lock(&log->l_icloglock);
1979
1980 be32_add_cpu(&iclog->ic_header.h_num_logops, record_cnt);
1981 iclog->ic_offset += copy_bytes;
1982
1983 spin_unlock(&log->l_icloglock);
1984} /* xlog_state_finish_copy */
1985
1986
1987
1988
1989/*
1990 * print out info relating to regions written which consume
1991 * the reservation
1992 */
1993void
1994xlog_print_tic_res(
1995 struct xfs_mount *mp,
1996 struct xlog_ticket *ticket)
1997{
1998 uint i;
1999 uint ophdr_spc = ticket->t_res_num_ophdrs * (uint)sizeof(xlog_op_header_t);
2000
2001 /* match with XLOG_REG_TYPE_* in xfs_log.h */
2002#define REG_TYPE_STR(type, str) [XLOG_REG_TYPE_##type] = str
2003 static char *res_type_str[XLOG_REG_TYPE_MAX + 1] = {
2004 REG_TYPE_STR(BFORMAT, "bformat"),
2005 REG_TYPE_STR(BCHUNK, "bchunk"),
2006 REG_TYPE_STR(EFI_FORMAT, "efi_format"),
2007 REG_TYPE_STR(EFD_FORMAT, "efd_format"),
2008 REG_TYPE_STR(IFORMAT, "iformat"),
2009 REG_TYPE_STR(ICORE, "icore"),
2010 REG_TYPE_STR(IEXT, "iext"),
2011 REG_TYPE_STR(IBROOT, "ibroot"),
2012 REG_TYPE_STR(ILOCAL, "ilocal"),
2013 REG_TYPE_STR(IATTR_EXT, "iattr_ext"),
2014 REG_TYPE_STR(IATTR_BROOT, "iattr_broot"),
2015 REG_TYPE_STR(IATTR_LOCAL, "iattr_local"),
2016 REG_TYPE_STR(QFORMAT, "qformat"),
2017 REG_TYPE_STR(DQUOT, "dquot"),
2018 REG_TYPE_STR(QUOTAOFF, "quotaoff"),
2019 REG_TYPE_STR(LRHEADER, "LR header"),
2020 REG_TYPE_STR(UNMOUNT, "unmount"),
2021 REG_TYPE_STR(COMMIT, "commit"),
2022 REG_TYPE_STR(TRANSHDR, "trans header"),
2023 REG_TYPE_STR(ICREATE, "inode create")
2024 };
2025#undef REG_TYPE_STR
2026
2027 xfs_warn(mp, "xlog_write: reservation summary:");
2028 xfs_warn(mp, " unit res = %d bytes",
2029 ticket->t_unit_res);
2030 xfs_warn(mp, " current res = %d bytes",
2031 ticket->t_curr_res);
2032 xfs_warn(mp, " total reg = %u bytes (o/flow = %u bytes)",
2033 ticket->t_res_arr_sum, ticket->t_res_o_flow);
2034 xfs_warn(mp, " ophdrs = %u (ophdr space = %u bytes)",
2035 ticket->t_res_num_ophdrs, ophdr_spc);
2036 xfs_warn(mp, " ophdr + reg = %u bytes",
2037 ticket->t_res_arr_sum + ticket->t_res_o_flow + ophdr_spc);
2038 xfs_warn(mp, " num regions = %u",
2039 ticket->t_res_num);
2040
2041 for (i = 0; i < ticket->t_res_num; i++) {
2042 uint r_type = ticket->t_res_arr[i].r_type;
2043 xfs_warn(mp, "region[%u]: %s - %u bytes", i,
2044 ((r_type <= 0 || r_type > XLOG_REG_TYPE_MAX) ?
2045 "bad-rtype" : res_type_str[r_type]),
2046 ticket->t_res_arr[i].r_len);
2047 }
2048
2049 xfs_alert_tag(mp, XFS_PTAG_LOGRES,
2050 "xlog_write: reservation ran out. Need to up reservation");
2051 xfs_force_shutdown(mp, SHUTDOWN_LOG_IO_ERROR);
2052}
2053
2054/*
2055 * Calculate the potential space needed by the log vector. Each region gets
2056 * its own xlog_op_header_t and may need to be double word aligned.
2057 */
2058static int
2059xlog_write_calc_vec_length(
2060 struct xlog_ticket *ticket,
2061 struct xfs_log_vec *log_vector)
2062{
2063 struct xfs_log_vec *lv;
2064 int headers = 0;
2065 int len = 0;
2066 int i;
2067
2068 /* acct for start rec of xact */
2069 if (ticket->t_flags & XLOG_TIC_INITED)
2070 headers++;
2071
2072 for (lv = log_vector; lv; lv = lv->lv_next) {
2073 /* we don't write ordered log vectors */
2074 if (lv->lv_buf_len == XFS_LOG_VEC_ORDERED)
2075 continue;
2076
2077 headers += lv->lv_niovecs;
2078
2079 for (i = 0; i < lv->lv_niovecs; i++) {
2080 struct xfs_log_iovec *vecp = &lv->lv_iovecp[i];
2081
2082 len += vecp->i_len;
2083 xlog_tic_add_region(ticket, vecp->i_len, vecp->i_type);
2084 }
2085 }
2086
2087 ticket->t_res_num_ophdrs += headers;
2088 len += headers * sizeof(struct xlog_op_header);
2089
2090 return len;
2091}
2092
2093/*
2094 * If first write for transaction, insert start record We can't be trying to
2095 * commit if we are inited. We can't have any "partial_copy" if we are inited.
2096 */
2097static int
2098xlog_write_start_rec(
2099 struct xlog_op_header *ophdr,
2100 struct xlog_ticket *ticket)
2101{
2102 if (!(ticket->t_flags & XLOG_TIC_INITED))
2103 return 0;
2104
2105 ophdr->oh_tid = cpu_to_be32(ticket->t_tid);
2106 ophdr->oh_clientid = ticket->t_clientid;
2107 ophdr->oh_len = 0;
2108 ophdr->oh_flags = XLOG_START_TRANS;
2109 ophdr->oh_res2 = 0;
2110
2111 ticket->t_flags &= ~XLOG_TIC_INITED;
2112
2113 return sizeof(struct xlog_op_header);
2114}
2115
2116static xlog_op_header_t *
2117xlog_write_setup_ophdr(
2118 struct xlog *log,
2119 struct xlog_op_header *ophdr,
2120 struct xlog_ticket *ticket,
2121 uint flags)
2122{
2123 ophdr->oh_tid = cpu_to_be32(ticket->t_tid);
2124 ophdr->oh_clientid = ticket->t_clientid;
2125 ophdr->oh_res2 = 0;
2126
2127 /* are we copying a commit or unmount record? */
2128 ophdr->oh_flags = flags;
2129
2130 /*
2131 * We've seen logs corrupted with bad transaction client ids. This
2132 * makes sure that XFS doesn't generate them on. Turn this into an EIO
2133 * and shut down the filesystem.
2134 */
2135 switch (ophdr->oh_clientid) {
2136 case XFS_TRANSACTION:
2137 case XFS_VOLUME:
2138 case XFS_LOG:
2139 break;
2140 default:
2141 xfs_warn(log->l_mp,
2142 "Bad XFS transaction clientid 0x%x in ticket 0x%p",
2143 ophdr->oh_clientid, ticket);
2144 return NULL;
2145 }
2146
2147 return ophdr;
2148}
2149
2150/*
2151 * Set up the parameters of the region copy into the log. This has
2152 * to handle region write split across multiple log buffers - this
2153 * state is kept external to this function so that this code can
2154 * be written in an obvious, self documenting manner.
2155 */
2156static int
2157xlog_write_setup_copy(
2158 struct xlog_ticket *ticket,
2159 struct xlog_op_header *ophdr,
2160 int space_available,
2161 int space_required,
2162 int *copy_off,
2163 int *copy_len,
2164 int *last_was_partial_copy,
2165 int *bytes_consumed)
2166{
2167 int still_to_copy;
2168
2169 still_to_copy = space_required - *bytes_consumed;
2170 *copy_off = *bytes_consumed;
2171
2172 if (still_to_copy <= space_available) {
2173 /* write of region completes here */
2174 *copy_len = still_to_copy;
2175 ophdr->oh_len = cpu_to_be32(*copy_len);
2176 if (*last_was_partial_copy)
2177 ophdr->oh_flags |= (XLOG_END_TRANS|XLOG_WAS_CONT_TRANS);
2178 *last_was_partial_copy = 0;
2179 *bytes_consumed = 0;
2180 return 0;
2181 }
2182
2183 /* partial write of region, needs extra log op header reservation */
2184 *copy_len = space_available;
2185 ophdr->oh_len = cpu_to_be32(*copy_len);
2186 ophdr->oh_flags |= XLOG_CONTINUE_TRANS;
2187 if (*last_was_partial_copy)
2188 ophdr->oh_flags |= XLOG_WAS_CONT_TRANS;
2189 *bytes_consumed += *copy_len;
2190 (*last_was_partial_copy)++;
2191
2192 /* account for new log op header */
2193 ticket->t_curr_res -= sizeof(struct xlog_op_header);
2194 ticket->t_res_num_ophdrs++;
2195
2196 return sizeof(struct xlog_op_header);
2197}
2198
2199static int
2200xlog_write_copy_finish(
2201 struct xlog *log,
2202 struct xlog_in_core *iclog,
2203 uint flags,
2204 int *record_cnt,
2205 int *data_cnt,
2206 int *partial_copy,
2207 int *partial_copy_len,
2208 int log_offset,
2209 struct xlog_in_core **commit_iclog)
2210{
2211 if (*partial_copy) {
2212 /*
2213 * This iclog has already been marked WANT_SYNC by
2214 * xlog_state_get_iclog_space.
2215 */
2216 xlog_state_finish_copy(log, iclog, *record_cnt, *data_cnt);
2217 *record_cnt = 0;
2218 *data_cnt = 0;
2219 return xlog_state_release_iclog(log, iclog);
2220 }
2221
2222 *partial_copy = 0;
2223 *partial_copy_len = 0;
2224
2225 if (iclog->ic_size - log_offset <= sizeof(xlog_op_header_t)) {
2226 /* no more space in this iclog - push it. */
2227 xlog_state_finish_copy(log, iclog, *record_cnt, *data_cnt);
2228 *record_cnt = 0;
2229 *data_cnt = 0;
2230
2231 spin_lock(&log->l_icloglock);
2232 xlog_state_want_sync(log, iclog);
2233 spin_unlock(&log->l_icloglock);
2234
2235 if (!commit_iclog)
2236 return xlog_state_release_iclog(log, iclog);
2237 ASSERT(flags & XLOG_COMMIT_TRANS);
2238 *commit_iclog = iclog;
2239 }
2240
2241 return 0;
2242}
2243
2244/*
2245 * Write some region out to in-core log
2246 *
2247 * This will be called when writing externally provided regions or when
2248 * writing out a commit record for a given transaction.
2249 *
2250 * General algorithm:
2251 * 1. Find total length of this write. This may include adding to the
2252 * lengths passed in.
2253 * 2. Check whether we violate the tickets reservation.
2254 * 3. While writing to this iclog
2255 * A. Reserve as much space in this iclog as can get
2256 * B. If this is first write, save away start lsn
2257 * C. While writing this region:
2258 * 1. If first write of transaction, write start record
2259 * 2. Write log operation header (header per region)
2260 * 3. Find out if we can fit entire region into this iclog
2261 * 4. Potentially, verify destination memcpy ptr
2262 * 5. Memcpy (partial) region
2263 * 6. If partial copy, release iclog; otherwise, continue
2264 * copying more regions into current iclog
2265 * 4. Mark want sync bit (in simulation mode)
2266 * 5. Release iclog for potential flush to on-disk log.
2267 *
2268 * ERRORS:
2269 * 1. Panic if reservation is overrun. This should never happen since
2270 * reservation amounts are generated internal to the filesystem.
2271 * NOTES:
2272 * 1. Tickets are single threaded data structures.
2273 * 2. The XLOG_END_TRANS & XLOG_CONTINUE_TRANS flags are passed down to the
2274 * syncing routine. When a single log_write region needs to span
2275 * multiple in-core logs, the XLOG_CONTINUE_TRANS bit should be set
2276 * on all log operation writes which don't contain the end of the
2277 * region. The XLOG_END_TRANS bit is used for the in-core log
2278 * operation which contains the end of the continued log_write region.
2279 * 3. When xlog_state_get_iclog_space() grabs the rest of the current iclog,
2280 * we don't really know exactly how much space will be used. As a result,
2281 * we don't update ic_offset until the end when we know exactly how many
2282 * bytes have been written out.
2283 */
2284int
2285xlog_write(
2286 struct xlog *log,
2287 struct xfs_log_vec *log_vector,
2288 struct xlog_ticket *ticket,
2289 xfs_lsn_t *start_lsn,
2290 struct xlog_in_core **commit_iclog,
2291 uint flags)
2292{
2293 struct xlog_in_core *iclog = NULL;
2294 struct xfs_log_iovec *vecp;
2295 struct xfs_log_vec *lv;
2296 int len;
2297 int index;
2298 int partial_copy = 0;
2299 int partial_copy_len = 0;
2300 int contwr = 0;
2301 int record_cnt = 0;
2302 int data_cnt = 0;
2303 int error;
2304
2305 *start_lsn = 0;
2306
2307 len = xlog_write_calc_vec_length(ticket, log_vector);
2308
2309 /*
2310 * Region headers and bytes are already accounted for.
2311 * We only need to take into account start records and
2312 * split regions in this function.
2313 */
2314 if (ticket->t_flags & XLOG_TIC_INITED)
2315 ticket->t_curr_res -= sizeof(xlog_op_header_t);
2316
2317 /*
2318 * Commit record headers need to be accounted for. These
2319 * come in as separate writes so are easy to detect.
2320 */
2321 if (flags & (XLOG_COMMIT_TRANS | XLOG_UNMOUNT_TRANS))
2322 ticket->t_curr_res -= sizeof(xlog_op_header_t);
2323
2324 if (ticket->t_curr_res < 0)
2325 xlog_print_tic_res(log->l_mp, ticket);
2326
2327 index = 0;
2328 lv = log_vector;
2329 vecp = lv->lv_iovecp;
2330 while (lv && (!lv->lv_niovecs || index < lv->lv_niovecs)) {
2331 void *ptr;
2332 int log_offset;
2333
2334 error = xlog_state_get_iclog_space(log, len, &iclog, ticket,
2335 &contwr, &log_offset);
2336 if (error)
2337 return error;
2338
2339 ASSERT(log_offset <= iclog->ic_size - 1);
2340 ptr = iclog->ic_datap + log_offset;
2341
2342 /* start_lsn is the first lsn written to. That's all we need. */
2343 if (!*start_lsn)
2344 *start_lsn = be64_to_cpu(iclog->ic_header.h_lsn);
2345
2346 /*
2347 * This loop writes out as many regions as can fit in the amount
2348 * of space which was allocated by xlog_state_get_iclog_space().
2349 */
2350 while (lv && (!lv->lv_niovecs || index < lv->lv_niovecs)) {
2351 struct xfs_log_iovec *reg;
2352 struct xlog_op_header *ophdr;
2353 int start_rec_copy;
2354 int copy_len;
2355 int copy_off;
2356 bool ordered = false;
2357
2358 /* ordered log vectors have no regions to write */
2359 if (lv->lv_buf_len == XFS_LOG_VEC_ORDERED) {
2360 ASSERT(lv->lv_niovecs == 0);
2361 ordered = true;
2362 goto next_lv;
2363 }
2364
2365 reg = &vecp[index];
2366 ASSERT(reg->i_len % sizeof(__int32_t) == 0);
2367 ASSERT((unsigned long)ptr % sizeof(__int32_t) == 0);
2368
2369 start_rec_copy = xlog_write_start_rec(ptr, ticket);
2370 if (start_rec_copy) {
2371 record_cnt++;
2372 xlog_write_adv_cnt(&ptr, &len, &log_offset,
2373 start_rec_copy);
2374 }
2375
2376 ophdr = xlog_write_setup_ophdr(log, ptr, ticket, flags);
2377 if (!ophdr)
2378 return -EIO;
2379
2380 xlog_write_adv_cnt(&ptr, &len, &log_offset,
2381 sizeof(struct xlog_op_header));
2382
2383 len += xlog_write_setup_copy(ticket, ophdr,
2384 iclog->ic_size-log_offset,
2385 reg->i_len,
2386 ©_off, ©_len,
2387 &partial_copy,
2388 &partial_copy_len);
2389 xlog_verify_dest_ptr(log, ptr);
2390
2391 /*
2392 * Copy region.
2393 *
2394 * Unmount records just log an opheader, so can have
2395 * empty payloads with no data region to copy. Hence we
2396 * only copy the payload if the vector says it has data
2397 * to copy.
2398 */
2399 ASSERT(copy_len >= 0);
2400 if (copy_len > 0) {
2401 memcpy(ptr, reg->i_addr + copy_off, copy_len);
2402 xlog_write_adv_cnt(&ptr, &len, &log_offset,
2403 copy_len);
2404 }
2405 copy_len += start_rec_copy + sizeof(xlog_op_header_t);
2406 record_cnt++;
2407 data_cnt += contwr ? copy_len : 0;
2408
2409 error = xlog_write_copy_finish(log, iclog, flags,
2410 &record_cnt, &data_cnt,
2411 &partial_copy,
2412 &partial_copy_len,
2413 log_offset,
2414 commit_iclog);
2415 if (error)
2416 return error;
2417
2418 /*
2419 * if we had a partial copy, we need to get more iclog
2420 * space but we don't want to increment the region
2421 * index because there is still more is this region to
2422 * write.
2423 *
2424 * If we completed writing this region, and we flushed
2425 * the iclog (indicated by resetting of the record
2426 * count), then we also need to get more log space. If
2427 * this was the last record, though, we are done and
2428 * can just return.
2429 */
2430 if (partial_copy)
2431 break;
2432
2433 if (++index == lv->lv_niovecs) {
2434next_lv:
2435 lv = lv->lv_next;
2436 index = 0;
2437 if (lv)
2438 vecp = lv->lv_iovecp;
2439 }
2440 if (record_cnt == 0 && ordered == false) {
2441 if (!lv)
2442 return 0;
2443 break;
2444 }
2445 }
2446 }
2447
2448 ASSERT(len == 0);
2449
2450 xlog_state_finish_copy(log, iclog, record_cnt, data_cnt);
2451 if (!commit_iclog)
2452 return xlog_state_release_iclog(log, iclog);
2453
2454 ASSERT(flags & XLOG_COMMIT_TRANS);
2455 *commit_iclog = iclog;
2456 return 0;
2457}
2458
2459
2460/*****************************************************************************
2461 *
2462 * State Machine functions
2463 *
2464 *****************************************************************************
2465 */
2466
2467/* Clean iclogs starting from the head. This ordering must be
2468 * maintained, so an iclog doesn't become ACTIVE beyond one that
2469 * is SYNCING. This is also required to maintain the notion that we use
2470 * a ordered wait queue to hold off would be writers to the log when every
2471 * iclog is trying to sync to disk.
2472 *
2473 * State Change: DIRTY -> ACTIVE
2474 */
2475STATIC void
2476xlog_state_clean_log(
2477 struct xlog *log)
2478{
2479 xlog_in_core_t *iclog;
2480 int changed = 0;
2481
2482 iclog = log->l_iclog;
2483 do {
2484 if (iclog->ic_state == XLOG_STATE_DIRTY) {
2485 iclog->ic_state = XLOG_STATE_ACTIVE;
2486 iclog->ic_offset = 0;
2487 ASSERT(iclog->ic_callback == NULL);
2488 /*
2489 * If the number of ops in this iclog indicate it just
2490 * contains the dummy transaction, we can
2491 * change state into IDLE (the second time around).
2492 * Otherwise we should change the state into
2493 * NEED a dummy.
2494 * We don't need to cover the dummy.
2495 */
2496 if (!changed &&
2497 (be32_to_cpu(iclog->ic_header.h_num_logops) ==
2498 XLOG_COVER_OPS)) {
2499 changed = 1;
2500 } else {
2501 /*
2502 * We have two dirty iclogs so start over
2503 * This could also be num of ops indicates
2504 * this is not the dummy going out.
2505 */
2506 changed = 2;
2507 }
2508 iclog->ic_header.h_num_logops = 0;
2509 memset(iclog->ic_header.h_cycle_data, 0,
2510 sizeof(iclog->ic_header.h_cycle_data));
2511 iclog->ic_header.h_lsn = 0;
2512 } else if (iclog->ic_state == XLOG_STATE_ACTIVE)
2513 /* do nothing */;
2514 else
2515 break; /* stop cleaning */
2516 iclog = iclog->ic_next;
2517 } while (iclog != log->l_iclog);
2518
2519 /* log is locked when we are called */
2520 /*
2521 * Change state for the dummy log recording.
2522 * We usually go to NEED. But we go to NEED2 if the changed indicates
2523 * we are done writing the dummy record.
2524 * If we are done with the second dummy recored (DONE2), then
2525 * we go to IDLE.
2526 */
2527 if (changed) {
2528 switch (log->l_covered_state) {
2529 case XLOG_STATE_COVER_IDLE:
2530 case XLOG_STATE_COVER_NEED:
2531 case XLOG_STATE_COVER_NEED2:
2532 log->l_covered_state = XLOG_STATE_COVER_NEED;
2533 break;
2534
2535 case XLOG_STATE_COVER_DONE:
2536 if (changed == 1)
2537 log->l_covered_state = XLOG_STATE_COVER_NEED2;
2538 else
2539 log->l_covered_state = XLOG_STATE_COVER_NEED;
2540 break;
2541
2542 case XLOG_STATE_COVER_DONE2:
2543 if (changed == 1)
2544 log->l_covered_state = XLOG_STATE_COVER_IDLE;
2545 else
2546 log->l_covered_state = XLOG_STATE_COVER_NEED;
2547 break;
2548
2549 default:
2550 ASSERT(0);
2551 }
2552 }
2553} /* xlog_state_clean_log */
2554
2555STATIC xfs_lsn_t
2556xlog_get_lowest_lsn(
2557 struct xlog *log)
2558{
2559 xlog_in_core_t *lsn_log;
2560 xfs_lsn_t lowest_lsn, lsn;
2561
2562 lsn_log = log->l_iclog;
2563 lowest_lsn = 0;
2564 do {
2565 if (!(lsn_log->ic_state & (XLOG_STATE_ACTIVE|XLOG_STATE_DIRTY))) {
2566 lsn = be64_to_cpu(lsn_log->ic_header.h_lsn);
2567 if ((lsn && !lowest_lsn) ||
2568 (XFS_LSN_CMP(lsn, lowest_lsn) < 0)) {
2569 lowest_lsn = lsn;
2570 }
2571 }
2572 lsn_log = lsn_log->ic_next;
2573 } while (lsn_log != log->l_iclog);
2574 return lowest_lsn;
2575}
2576
2577
2578STATIC void
2579xlog_state_do_callback(
2580 struct xlog *log,
2581 int aborted,
2582 struct xlog_in_core *ciclog)
2583{
2584 xlog_in_core_t *iclog;
2585 xlog_in_core_t *first_iclog; /* used to know when we've
2586 * processed all iclogs once */
2587 xfs_log_callback_t *cb, *cb_next;
2588 int flushcnt = 0;
2589 xfs_lsn_t lowest_lsn;
2590 int ioerrors; /* counter: iclogs with errors */
2591 int loopdidcallbacks; /* flag: inner loop did callbacks*/
2592 int funcdidcallbacks; /* flag: function did callbacks */
2593 int repeats; /* for issuing console warnings if
2594 * looping too many times */
2595 int wake = 0;
2596
2597 spin_lock(&log->l_icloglock);
2598 first_iclog = iclog = log->l_iclog;
2599 ioerrors = 0;
2600 funcdidcallbacks = 0;
2601 repeats = 0;
2602
2603 do {
2604 /*
2605 * Scan all iclogs starting with the one pointed to by the
2606 * log. Reset this starting point each time the log is
2607 * unlocked (during callbacks).
2608 *
2609 * Keep looping through iclogs until one full pass is made
2610 * without running any callbacks.
2611 */
2612 first_iclog = log->l_iclog;
2613 iclog = log->l_iclog;
2614 loopdidcallbacks = 0;
2615 repeats++;
2616
2617 do {
2618
2619 /* skip all iclogs in the ACTIVE & DIRTY states */
2620 if (iclog->ic_state &
2621 (XLOG_STATE_ACTIVE|XLOG_STATE_DIRTY)) {
2622 iclog = iclog->ic_next;
2623 continue;
2624 }
2625
2626 /*
2627 * Between marking a filesystem SHUTDOWN and stopping
2628 * the log, we do flush all iclogs to disk (if there
2629 * wasn't a log I/O error). So, we do want things to
2630 * go smoothly in case of just a SHUTDOWN w/o a
2631 * LOG_IO_ERROR.
2632 */
2633 if (!(iclog->ic_state & XLOG_STATE_IOERROR)) {
2634 /*
2635 * Can only perform callbacks in order. Since
2636 * this iclog is not in the DONE_SYNC/
2637 * DO_CALLBACK state, we skip the rest and
2638 * just try to clean up. If we set our iclog
2639 * to DO_CALLBACK, we will not process it when
2640 * we retry since a previous iclog is in the
2641 * CALLBACK and the state cannot change since
2642 * we are holding the l_icloglock.
2643 */
2644 if (!(iclog->ic_state &
2645 (XLOG_STATE_DONE_SYNC |
2646 XLOG_STATE_DO_CALLBACK))) {
2647 if (ciclog && (ciclog->ic_state ==
2648 XLOG_STATE_DONE_SYNC)) {
2649 ciclog->ic_state = XLOG_STATE_DO_CALLBACK;
2650 }
2651 break;
2652 }
2653 /*
2654 * We now have an iclog that is in either the
2655 * DO_CALLBACK or DONE_SYNC states. The other
2656 * states (WANT_SYNC, SYNCING, or CALLBACK were
2657 * caught by the above if and are going to
2658 * clean (i.e. we aren't doing their callbacks)
2659 * see the above if.
2660 */
2661
2662 /*
2663 * We will do one more check here to see if we
2664 * have chased our tail around.
2665 */
2666
2667 lowest_lsn = xlog_get_lowest_lsn(log);
2668 if (lowest_lsn &&
2669 XFS_LSN_CMP(lowest_lsn,
2670 be64_to_cpu(iclog->ic_header.h_lsn)) < 0) {
2671 iclog = iclog->ic_next;
2672 continue; /* Leave this iclog for
2673 * another thread */
2674 }
2675
2676 iclog->ic_state = XLOG_STATE_CALLBACK;
2677
2678
2679 /*
2680 * Completion of a iclog IO does not imply that
2681 * a transaction has completed, as transactions
2682 * can be large enough to span many iclogs. We
2683 * cannot change the tail of the log half way
2684 * through a transaction as this may be the only
2685 * transaction in the log and moving th etail to
2686 * point to the middle of it will prevent
2687 * recovery from finding the start of the
2688 * transaction. Hence we should only update the
2689 * last_sync_lsn if this iclog contains
2690 * transaction completion callbacks on it.
2691 *
2692 * We have to do this before we drop the
2693 * icloglock to ensure we are the only one that
2694 * can update it.
2695 */
2696 ASSERT(XFS_LSN_CMP(atomic64_read(&log->l_last_sync_lsn),
2697 be64_to_cpu(iclog->ic_header.h_lsn)) <= 0);
2698 if (iclog->ic_callback)
2699 atomic64_set(&log->l_last_sync_lsn,
2700 be64_to_cpu(iclog->ic_header.h_lsn));
2701
2702 } else
2703 ioerrors++;
2704
2705 spin_unlock(&log->l_icloglock);
2706
2707 /*
2708 * Keep processing entries in the callback list until
2709 * we come around and it is empty. We need to
2710 * atomically see that the list is empty and change the
2711 * state to DIRTY so that we don't miss any more
2712 * callbacks being added.
2713 */
2714 spin_lock(&iclog->ic_callback_lock);
2715 cb = iclog->ic_callback;
2716 while (cb) {
2717 iclog->ic_callback_tail = &(iclog->ic_callback);
2718 iclog->ic_callback = NULL;
2719 spin_unlock(&iclog->ic_callback_lock);
2720
2721 /* perform callbacks in the order given */
2722 for (; cb; cb = cb_next) {
2723 cb_next = cb->cb_next;
2724 cb->cb_func(cb->cb_arg, aborted);
2725 }
2726 spin_lock(&iclog->ic_callback_lock);
2727 cb = iclog->ic_callback;
2728 }
2729
2730 loopdidcallbacks++;
2731 funcdidcallbacks++;
2732
2733 spin_lock(&log->l_icloglock);
2734 ASSERT(iclog->ic_callback == NULL);
2735 spin_unlock(&iclog->ic_callback_lock);
2736 if (!(iclog->ic_state & XLOG_STATE_IOERROR))
2737 iclog->ic_state = XLOG_STATE_DIRTY;
2738
2739 /*
2740 * Transition from DIRTY to ACTIVE if applicable.
2741 * NOP if STATE_IOERROR.
2742 */
2743 xlog_state_clean_log(log);
2744
2745 /* wake up threads waiting in xfs_log_force() */
2746 wake_up_all(&iclog->ic_force_wait);
2747
2748 iclog = iclog->ic_next;
2749 } while (first_iclog != iclog);
2750
2751 if (repeats > 5000) {
2752 flushcnt += repeats;
2753 repeats = 0;
2754 xfs_warn(log->l_mp,
2755 "%s: possible infinite loop (%d iterations)",
2756 __func__, flushcnt);
2757 }
2758 } while (!ioerrors && loopdidcallbacks);
2759
2760#ifdef DEBUG
2761 /*
2762 * Make one last gasp attempt to see if iclogs are being left in limbo.
2763 * If the above loop finds an iclog earlier than the current iclog and
2764 * in one of the syncing states, the current iclog is put into
2765 * DO_CALLBACK and the callbacks are deferred to the completion of the
2766 * earlier iclog. Walk the iclogs in order and make sure that no iclog
2767 * is in DO_CALLBACK unless an earlier iclog is in one of the syncing
2768 * states.
2769 *
2770 * Note that SYNCING|IOABORT is a valid state so we cannot just check
2771 * for ic_state == SYNCING.
2772 */
2773 if (funcdidcallbacks) {
2774 first_iclog = iclog = log->l_iclog;
2775 do {
2776 ASSERT(iclog->ic_state != XLOG_STATE_DO_CALLBACK);
2777 /*
2778 * Terminate the loop if iclogs are found in states
2779 * which will cause other threads to clean up iclogs.
2780 *
2781 * SYNCING - i/o completion will go through logs
2782 * DONE_SYNC - interrupt thread should be waiting for
2783 * l_icloglock
2784 * IOERROR - give up hope all ye who enter here
2785 */
2786 if (iclog->ic_state == XLOG_STATE_WANT_SYNC ||
2787 iclog->ic_state & XLOG_STATE_SYNCING ||
2788 iclog->ic_state == XLOG_STATE_DONE_SYNC ||
2789 iclog->ic_state == XLOG_STATE_IOERROR )
2790 break;
2791 iclog = iclog->ic_next;
2792 } while (first_iclog != iclog);
2793 }
2794#endif
2795
2796 if (log->l_iclog->ic_state & (XLOG_STATE_ACTIVE|XLOG_STATE_IOERROR))
2797 wake = 1;
2798 spin_unlock(&log->l_icloglock);
2799
2800 if (wake)
2801 wake_up_all(&log->l_flush_wait);
2802}
2803
2804
2805/*
2806 * Finish transitioning this iclog to the dirty state.
2807 *
2808 * Make sure that we completely execute this routine only when this is
2809 * the last call to the iclog. There is a good chance that iclog flushes,
2810 * when we reach the end of the physical log, get turned into 2 separate
2811 * calls to bwrite. Hence, one iclog flush could generate two calls to this
2812 * routine. By using the reference count bwritecnt, we guarantee that only
2813 * the second completion goes through.
2814 *
2815 * Callbacks could take time, so they are done outside the scope of the
2816 * global state machine log lock.
2817 */
2818STATIC void
2819xlog_state_done_syncing(
2820 xlog_in_core_t *iclog,
2821 int aborted)
2822{
2823 struct xlog *log = iclog->ic_log;
2824
2825 spin_lock(&log->l_icloglock);
2826
2827 ASSERT(iclog->ic_state == XLOG_STATE_SYNCING ||
2828 iclog->ic_state == XLOG_STATE_IOERROR);
2829 ASSERT(atomic_read(&iclog->ic_refcnt) == 0);
2830 ASSERT(iclog->ic_bwritecnt == 1 || iclog->ic_bwritecnt == 2);
2831
2832
2833 /*
2834 * If we got an error, either on the first buffer, or in the case of
2835 * split log writes, on the second, we mark ALL iclogs STATE_IOERROR,
2836 * and none should ever be attempted to be written to disk
2837 * again.
2838 */
2839 if (iclog->ic_state != XLOG_STATE_IOERROR) {
2840 if (--iclog->ic_bwritecnt == 1) {
2841 spin_unlock(&log->l_icloglock);
2842 return;
2843 }
2844 iclog->ic_state = XLOG_STATE_DONE_SYNC;
2845 }
2846
2847 /*
2848 * Someone could be sleeping prior to writing out the next
2849 * iclog buffer, we wake them all, one will get to do the
2850 * I/O, the others get to wait for the result.
2851 */
2852 wake_up_all(&iclog->ic_write_wait);
2853 spin_unlock(&log->l_icloglock);
2854 xlog_state_do_callback(log, aborted, iclog); /* also cleans log */
2855} /* xlog_state_done_syncing */
2856
2857
2858/*
2859 * If the head of the in-core log ring is not (ACTIVE or DIRTY), then we must
2860 * sleep. We wait on the flush queue on the head iclog as that should be
2861 * the first iclog to complete flushing. Hence if all iclogs are syncing,
2862 * we will wait here and all new writes will sleep until a sync completes.
2863 *
2864 * The in-core logs are used in a circular fashion. They are not used
2865 * out-of-order even when an iclog past the head is free.
2866 *
2867 * return:
2868 * * log_offset where xlog_write() can start writing into the in-core
2869 * log's data space.
2870 * * in-core log pointer to which xlog_write() should write.
2871 * * boolean indicating this is a continued write to an in-core log.
2872 * If this is the last write, then the in-core log's offset field
2873 * needs to be incremented, depending on the amount of data which
2874 * is copied.
2875 */
2876STATIC int
2877xlog_state_get_iclog_space(
2878 struct xlog *log,
2879 int len,
2880 struct xlog_in_core **iclogp,
2881 struct xlog_ticket *ticket,
2882 int *continued_write,
2883 int *logoffsetp)
2884{
2885 int log_offset;
2886 xlog_rec_header_t *head;
2887 xlog_in_core_t *iclog;
2888 int error;
2889
2890restart:
2891 spin_lock(&log->l_icloglock);
2892 if (XLOG_FORCED_SHUTDOWN(log)) {
2893 spin_unlock(&log->l_icloglock);
2894 return -EIO;
2895 }
2896
2897 iclog = log->l_iclog;
2898 if (iclog->ic_state != XLOG_STATE_ACTIVE) {
2899 XFS_STATS_INC(log->l_mp, xs_log_noiclogs);
2900
2901 /* Wait for log writes to have flushed */
2902 xlog_wait(&log->l_flush_wait, &log->l_icloglock);
2903 goto restart;
2904 }
2905
2906 head = &iclog->ic_header;
2907
2908 atomic_inc(&iclog->ic_refcnt); /* prevents sync */
2909 log_offset = iclog->ic_offset;
2910
2911 /* On the 1st write to an iclog, figure out lsn. This works
2912 * if iclogs marked XLOG_STATE_WANT_SYNC always write out what they are
2913 * committing to. If the offset is set, that's how many blocks
2914 * must be written.
2915 */
2916 if (log_offset == 0) {
2917 ticket->t_curr_res -= log->l_iclog_hsize;
2918 xlog_tic_add_region(ticket,
2919 log->l_iclog_hsize,
2920 XLOG_REG_TYPE_LRHEADER);
2921 head->h_cycle = cpu_to_be32(log->l_curr_cycle);
2922 head->h_lsn = cpu_to_be64(
2923 xlog_assign_lsn(log->l_curr_cycle, log->l_curr_block));
2924 ASSERT(log->l_curr_block >= 0);
2925 }
2926
2927 /* If there is enough room to write everything, then do it. Otherwise,
2928 * claim the rest of the region and make sure the XLOG_STATE_WANT_SYNC
2929 * bit is on, so this will get flushed out. Don't update ic_offset
2930 * until you know exactly how many bytes get copied. Therefore, wait
2931 * until later to update ic_offset.
2932 *
2933 * xlog_write() algorithm assumes that at least 2 xlog_op_header_t's
2934 * can fit into remaining data section.
2935 */
2936 if (iclog->ic_size - iclog->ic_offset < 2*sizeof(xlog_op_header_t)) {
2937 xlog_state_switch_iclogs(log, iclog, iclog->ic_size);
2938
2939 /*
2940 * If I'm the only one writing to this iclog, sync it to disk.
2941 * We need to do an atomic compare and decrement here to avoid
2942 * racing with concurrent atomic_dec_and_lock() calls in
2943 * xlog_state_release_iclog() when there is more than one
2944 * reference to the iclog.
2945 */
2946 if (!atomic_add_unless(&iclog->ic_refcnt, -1, 1)) {
2947 /* we are the only one */
2948 spin_unlock(&log->l_icloglock);
2949 error = xlog_state_release_iclog(log, iclog);
2950 if (error)
2951 return error;
2952 } else {
2953 spin_unlock(&log->l_icloglock);
2954 }
2955 goto restart;
2956 }
2957
2958 /* Do we have enough room to write the full amount in the remainder
2959 * of this iclog? Or must we continue a write on the next iclog and
2960 * mark this iclog as completely taken? In the case where we switch
2961 * iclogs (to mark it taken), this particular iclog will release/sync
2962 * to disk in xlog_write().
2963 */
2964 if (len <= iclog->ic_size - iclog->ic_offset) {
2965 *continued_write = 0;
2966 iclog->ic_offset += len;
2967 } else {
2968 *continued_write = 1;
2969 xlog_state_switch_iclogs(log, iclog, iclog->ic_size);
2970 }
2971 *iclogp = iclog;
2972
2973 ASSERT(iclog->ic_offset <= iclog->ic_size);
2974 spin_unlock(&log->l_icloglock);
2975
2976 *logoffsetp = log_offset;
2977 return 0;
2978} /* xlog_state_get_iclog_space */
2979
2980/* The first cnt-1 times through here we don't need to
2981 * move the grant write head because the permanent
2982 * reservation has reserved cnt times the unit amount.
2983 * Release part of current permanent unit reservation and
2984 * reset current reservation to be one units worth. Also
2985 * move grant reservation head forward.
2986 */
2987STATIC void
2988xlog_regrant_reserve_log_space(
2989 struct xlog *log,
2990 struct xlog_ticket *ticket)
2991{
2992 trace_xfs_log_regrant_reserve_enter(log, ticket);
2993
2994 if (ticket->t_cnt > 0)
2995 ticket->t_cnt--;
2996
2997 xlog_grant_sub_space(log, &log->l_reserve_head.grant,
2998 ticket->t_curr_res);
2999 xlog_grant_sub_space(log, &log->l_write_head.grant,
3000 ticket->t_curr_res);
3001 ticket->t_curr_res = ticket->t_unit_res;
3002 xlog_tic_reset_res(ticket);
3003
3004 trace_xfs_log_regrant_reserve_sub(log, ticket);
3005
3006 /* just return if we still have some of the pre-reserved space */
3007 if (ticket->t_cnt > 0)
3008 return;
3009
3010 xlog_grant_add_space(log, &log->l_reserve_head.grant,
3011 ticket->t_unit_res);
3012
3013 trace_xfs_log_regrant_reserve_exit(log, ticket);
3014
3015 ticket->t_curr_res = ticket->t_unit_res;
3016 xlog_tic_reset_res(ticket);
3017} /* xlog_regrant_reserve_log_space */
3018
3019
3020/*
3021 * Give back the space left from a reservation.
3022 *
3023 * All the information we need to make a correct determination of space left
3024 * is present. For non-permanent reservations, things are quite easy. The
3025 * count should have been decremented to zero. We only need to deal with the
3026 * space remaining in the current reservation part of the ticket. If the
3027 * ticket contains a permanent reservation, there may be left over space which
3028 * needs to be released. A count of N means that N-1 refills of the current
3029 * reservation can be done before we need to ask for more space. The first
3030 * one goes to fill up the first current reservation. Once we run out of
3031 * space, the count will stay at zero and the only space remaining will be
3032 * in the current reservation field.
3033 */
3034STATIC void
3035xlog_ungrant_log_space(
3036 struct xlog *log,
3037 struct xlog_ticket *ticket)
3038{
3039 int bytes;
3040
3041 if (ticket->t_cnt > 0)
3042 ticket->t_cnt--;
3043
3044 trace_xfs_log_ungrant_enter(log, ticket);
3045 trace_xfs_log_ungrant_sub(log, ticket);
3046
3047 /*
3048 * If this is a permanent reservation ticket, we may be able to free
3049 * up more space based on the remaining count.
3050 */
3051 bytes = ticket->t_curr_res;
3052 if (ticket->t_cnt > 0) {
3053 ASSERT(ticket->t_flags & XLOG_TIC_PERM_RESERV);
3054 bytes += ticket->t_unit_res*ticket->t_cnt;
3055 }
3056
3057 xlog_grant_sub_space(log, &log->l_reserve_head.grant, bytes);
3058 xlog_grant_sub_space(log, &log->l_write_head.grant, bytes);
3059
3060 trace_xfs_log_ungrant_exit(log, ticket);
3061
3062 xfs_log_space_wake(log->l_mp);
3063}
3064
3065/*
3066 * Flush iclog to disk if this is the last reference to the given iclog and
3067 * the WANT_SYNC bit is set.
3068 *
3069 * When this function is entered, the iclog is not necessarily in the
3070 * WANT_SYNC state. It may be sitting around waiting to get filled.
3071 *
3072 *
3073 */
3074STATIC int
3075xlog_state_release_iclog(
3076 struct xlog *log,
3077 struct xlog_in_core *iclog)
3078{
3079 int sync = 0; /* do we sync? */
3080
3081 if (iclog->ic_state & XLOG_STATE_IOERROR)
3082 return -EIO;
3083
3084 ASSERT(atomic_read(&iclog->ic_refcnt) > 0);
3085 if (!atomic_dec_and_lock(&iclog->ic_refcnt, &log->l_icloglock))
3086 return 0;
3087
3088 if (iclog->ic_state & XLOG_STATE_IOERROR) {
3089 spin_unlock(&log->l_icloglock);
3090 return -EIO;
3091 }
3092 ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE ||
3093 iclog->ic_state == XLOG_STATE_WANT_SYNC);
3094
3095 if (iclog->ic_state == XLOG_STATE_WANT_SYNC) {
3096 /* update tail before writing to iclog */
3097 xfs_lsn_t tail_lsn = xlog_assign_tail_lsn(log->l_mp);
3098 sync++;
3099 iclog->ic_state = XLOG_STATE_SYNCING;
3100 iclog->ic_header.h_tail_lsn = cpu_to_be64(tail_lsn);
3101 xlog_verify_tail_lsn(log, iclog, tail_lsn);
3102 /* cycle incremented when incrementing curr_block */
3103 }
3104 spin_unlock(&log->l_icloglock);
3105
3106 /*
3107 * We let the log lock go, so it's possible that we hit a log I/O
3108 * error or some other SHUTDOWN condition that marks the iclog
3109 * as XLOG_STATE_IOERROR before the bwrite. However, we know that
3110 * this iclog has consistent data, so we ignore IOERROR
3111 * flags after this point.
3112 */
3113 if (sync)
3114 return xlog_sync(log, iclog);
3115 return 0;
3116} /* xlog_state_release_iclog */
3117
3118
3119/*
3120 * This routine will mark the current iclog in the ring as WANT_SYNC
3121 * and move the current iclog pointer to the next iclog in the ring.
3122 * When this routine is called from xlog_state_get_iclog_space(), the
3123 * exact size of the iclog has not yet been determined. All we know is
3124 * that every data block. We have run out of space in this log record.
3125 */
3126STATIC void
3127xlog_state_switch_iclogs(
3128 struct xlog *log,
3129 struct xlog_in_core *iclog,
3130 int eventual_size)
3131{
3132 ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE);
3133 if (!eventual_size)
3134 eventual_size = iclog->ic_offset;
3135 iclog->ic_state = XLOG_STATE_WANT_SYNC;
3136 iclog->ic_header.h_prev_block = cpu_to_be32(log->l_prev_block);
3137 log->l_prev_block = log->l_curr_block;
3138 log->l_prev_cycle = log->l_curr_cycle;
3139
3140 /* roll log?: ic_offset changed later */
3141 log->l_curr_block += BTOBB(eventual_size)+BTOBB(log->l_iclog_hsize);
3142
3143 /* Round up to next log-sunit */
3144 if (xfs_sb_version_haslogv2(&log->l_mp->m_sb) &&
3145 log->l_mp->m_sb.sb_logsunit > 1) {
3146 __uint32_t sunit_bb = BTOBB(log->l_mp->m_sb.sb_logsunit);
3147 log->l_curr_block = roundup(log->l_curr_block, sunit_bb);
3148 }
3149
3150 if (log->l_curr_block >= log->l_logBBsize) {
3151 /*
3152 * Rewind the current block before the cycle is bumped to make
3153 * sure that the combined LSN never transiently moves forward
3154 * when the log wraps to the next cycle. This is to support the
3155 * unlocked sample of these fields from xlog_valid_lsn(). Most
3156 * other cases should acquire l_icloglock.
3157 */
3158 log->l_curr_block -= log->l_logBBsize;
3159 ASSERT(log->l_curr_block >= 0);
3160 smp_wmb();
3161 log->l_curr_cycle++;
3162 if (log->l_curr_cycle == XLOG_HEADER_MAGIC_NUM)
3163 log->l_curr_cycle++;
3164 }
3165 ASSERT(iclog == log->l_iclog);
3166 log->l_iclog = iclog->ic_next;
3167} /* xlog_state_switch_iclogs */
3168
3169/*
3170 * Write out all data in the in-core log as of this exact moment in time.
3171 *
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.
3175 *
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:
3179 *
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.
3184 *
3185 * We may sleep if:
3186 *
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.
3195 */
3196int
3197_xfs_log_force(
3198 struct xfs_mount *mp,
3199 uint flags,
3200 int *log_flushed)
3201{
3202 struct xlog *log = mp->m_log;
3203 struct xlog_in_core *iclog;
3204 xfs_lsn_t lsn;
3205
3206 XFS_STATS_INC(mp, xs_log_force);
3207
3208 xlog_cil_force(log);
3209
3210 spin_lock(&log->l_icloglock);
3211
3212 iclog = log->l_iclog;
3213 if (iclog->ic_state & XLOG_STATE_IOERROR) {
3214 spin_unlock(&log->l_icloglock);
3215 return -EIO;
3216 }
3217
3218 /* If the head iclog is not active nor dirty, we just attach
3219 * ourselves to the head and go to sleep.
3220 */
3221 if (iclog->ic_state == XLOG_STATE_ACTIVE ||
3222 iclog->ic_state == XLOG_STATE_DIRTY) {
3223 /*
3224 * If the head is dirty or (active and empty), then
3225 * we need to look at the previous iclog. If the previous
3226 * iclog is active or dirty we are done. There is nothing
3227 * to sync out. Otherwise, we attach ourselves to the
3228 * previous iclog and go to sleep.
3229 */
3230 if (iclog->ic_state == XLOG_STATE_DIRTY ||
3231 (atomic_read(&iclog->ic_refcnt) == 0
3232 && iclog->ic_offset == 0)) {
3233 iclog = iclog->ic_prev;
3234 if (iclog->ic_state == XLOG_STATE_ACTIVE ||
3235 iclog->ic_state == XLOG_STATE_DIRTY)
3236 goto no_sleep;
3237 else
3238 goto maybe_sleep;
3239 } else {
3240 if (atomic_read(&iclog->ic_refcnt) == 0) {
3241 /* We are the only one with access to this
3242 * iclog. Flush it out now. There should
3243 * be a roundoff of zero to show that someone
3244 * has already taken care of the roundoff from
3245 * the previous sync.
3246 */
3247 atomic_inc(&iclog->ic_refcnt);
3248 lsn = be64_to_cpu(iclog->ic_header.h_lsn);
3249 xlog_state_switch_iclogs(log, iclog, 0);
3250 spin_unlock(&log->l_icloglock);
3251
3252 if (xlog_state_release_iclog(log, iclog))
3253 return -EIO;
3254
3255 if (log_flushed)
3256 *log_flushed = 1;
3257 spin_lock(&log->l_icloglock);
3258 if (be64_to_cpu(iclog->ic_header.h_lsn) == lsn &&
3259 iclog->ic_state != XLOG_STATE_DIRTY)
3260 goto maybe_sleep;
3261 else
3262 goto no_sleep;
3263 } else {
3264 /* Someone else is writing to this iclog.
3265 * Use its call to flush out the data. However,
3266 * the other thread may not force out this LR,
3267 * so we mark it WANT_SYNC.
3268 */
3269 xlog_state_switch_iclogs(log, iclog, 0);
3270 goto maybe_sleep;
3271 }
3272 }
3273 }
3274
3275 /* By the time we come around again, the iclog could've been filled
3276 * which would give it another lsn. If we have a new lsn, just
3277 * return because the relevant data has been flushed.
3278 */
3279maybe_sleep:
3280 if (flags & XFS_LOG_SYNC) {
3281 /*
3282 * We must check if we're shutting down here, before
3283 * we wait, while we're holding the l_icloglock.
3284 * Then we check again after waking up, in case our
3285 * sleep was disturbed by a bad news.
3286 */
3287 if (iclog->ic_state & XLOG_STATE_IOERROR) {
3288 spin_unlock(&log->l_icloglock);
3289 return -EIO;
3290 }
3291 XFS_STATS_INC(mp, xs_log_force_sleep);
3292 xlog_wait(&iclog->ic_force_wait, &log->l_icloglock);
3293 /*
3294 * No need to grab the log lock here since we're
3295 * only deciding whether or not to return EIO
3296 * and the memory read should be atomic.
3297 */
3298 if (iclog->ic_state & XLOG_STATE_IOERROR)
3299 return -EIO;
3300 if (log_flushed)
3301 *log_flushed = 1;
3302 } else {
3303
3304no_sleep:
3305 spin_unlock(&log->l_icloglock);
3306 }
3307 return 0;
3308}
3309
3310/*
3311 * Wrapper for _xfs_log_force(), to be used when caller doesn't care
3312 * about errors or whether the log was flushed or not. This is the normal
3313 * interface to use when trying to unpin items or move the log forward.
3314 */
3315void
3316xfs_log_force(
3317 xfs_mount_t *mp,
3318 uint flags)
3319{
3320 trace_xfs_log_force(mp, 0, _RET_IP_);
3321 _xfs_log_force(mp, flags, NULL);
3322}
3323
3324/*
3325 * Force the in-core log to disk for a specific LSN.
3326 *
3327 * Find in-core log with lsn.
3328 * If it is in the DIRTY state, just return.
3329 * If it is in the ACTIVE state, move the in-core log into the WANT_SYNC
3330 * state and go to sleep or return.
3331 * If it is in any other state, go to sleep or return.
3332 *
3333 * Synchronous forces are implemented with a signal variable. All callers
3334 * to force a given lsn to disk will wait on a the sv attached to the
3335 * specific in-core log. When given in-core log finally completes its
3336 * write to disk, that thread will wake up all threads waiting on the
3337 * sv.
3338 */
3339int
3340_xfs_log_force_lsn(
3341 struct xfs_mount *mp,
3342 xfs_lsn_t lsn,
3343 uint flags,
3344 int *log_flushed)
3345{
3346 struct xlog *log = mp->m_log;
3347 struct xlog_in_core *iclog;
3348 int already_slept = 0;
3349
3350 ASSERT(lsn != 0);
3351
3352 XFS_STATS_INC(mp, xs_log_force);
3353
3354 lsn = xlog_cil_force_lsn(log, lsn);
3355 if (lsn == NULLCOMMITLSN)
3356 return 0;
3357
3358try_again:
3359 spin_lock(&log->l_icloglock);
3360 iclog = log->l_iclog;
3361 if (iclog->ic_state & XLOG_STATE_IOERROR) {
3362 spin_unlock(&log->l_icloglock);
3363 return -EIO;
3364 }
3365
3366 do {
3367 if (be64_to_cpu(iclog->ic_header.h_lsn) != lsn) {
3368 iclog = iclog->ic_next;
3369 continue;
3370 }
3371
3372 if (iclog->ic_state == XLOG_STATE_DIRTY) {
3373 spin_unlock(&log->l_icloglock);
3374 return 0;
3375 }
3376
3377 if (iclog->ic_state == XLOG_STATE_ACTIVE) {
3378 /*
3379 * We sleep here if we haven't already slept (e.g.
3380 * this is the first time we've looked at the correct
3381 * iclog buf) and the buffer before us is going to
3382 * be sync'ed. The reason for this is that if we
3383 * are doing sync transactions here, by waiting for
3384 * the previous I/O to complete, we can allow a few
3385 * more transactions into this iclog before we close
3386 * it down.
3387 *
3388 * Otherwise, we mark the buffer WANT_SYNC, and bump
3389 * up the refcnt so we can release the log (which
3390 * drops the ref count). The state switch keeps new
3391 * transaction commits from using this buffer. When
3392 * the current commits finish writing into the buffer,
3393 * the refcount will drop to zero and the buffer will
3394 * go out then.
3395 */
3396 if (!already_slept &&
3397 (iclog->ic_prev->ic_state &
3398 (XLOG_STATE_WANT_SYNC | XLOG_STATE_SYNCING))) {
3399 ASSERT(!(iclog->ic_state & XLOG_STATE_IOERROR));
3400
3401 XFS_STATS_INC(mp, xs_log_force_sleep);
3402
3403 xlog_wait(&iclog->ic_prev->ic_write_wait,
3404 &log->l_icloglock);
3405 if (log_flushed)
3406 *log_flushed = 1;
3407 already_slept = 1;
3408 goto try_again;
3409 }
3410 atomic_inc(&iclog->ic_refcnt);
3411 xlog_state_switch_iclogs(log, iclog, 0);
3412 spin_unlock(&log->l_icloglock);
3413 if (xlog_state_release_iclog(log, iclog))
3414 return -EIO;
3415 if (log_flushed)
3416 *log_flushed = 1;
3417 spin_lock(&log->l_icloglock);
3418 }
3419
3420 if ((flags & XFS_LOG_SYNC) && /* sleep */
3421 !(iclog->ic_state &
3422 (XLOG_STATE_ACTIVE | XLOG_STATE_DIRTY))) {
3423 /*
3424 * Don't wait on completion if we know that we've
3425 * gotten a log write error.
3426 */
3427 if (iclog->ic_state & XLOG_STATE_IOERROR) {
3428 spin_unlock(&log->l_icloglock);
3429 return -EIO;
3430 }
3431 XFS_STATS_INC(mp, xs_log_force_sleep);
3432 xlog_wait(&iclog->ic_force_wait, &log->l_icloglock);
3433 /*
3434 * No need to grab the log lock here since we're
3435 * only deciding whether or not to return EIO
3436 * and the memory read should be atomic.
3437 */
3438 if (iclog->ic_state & XLOG_STATE_IOERROR)
3439 return -EIO;
3440
3441 if (log_flushed)
3442 *log_flushed = 1;
3443 } else { /* just return */
3444 spin_unlock(&log->l_icloglock);
3445 }
3446
3447 return 0;
3448 } while (iclog != log->l_iclog);
3449
3450 spin_unlock(&log->l_icloglock);
3451 return 0;
3452}
3453
3454/*
3455 * Wrapper for _xfs_log_force_lsn(), to be used when caller doesn't care
3456 * about errors or whether the log was flushed or not. This is the normal
3457 * interface to use when trying to unpin items or move the log forward.
3458 */
3459void
3460xfs_log_force_lsn(
3461 xfs_mount_t *mp,
3462 xfs_lsn_t lsn,
3463 uint flags)
3464{
3465 trace_xfs_log_force(mp, lsn, _RET_IP_);
3466 _xfs_log_force_lsn(mp, lsn, flags, NULL);
3467}
3468
3469/*
3470 * Called when we want to mark the current iclog as being ready to sync to
3471 * disk.
3472 */
3473STATIC void
3474xlog_state_want_sync(
3475 struct xlog *log,
3476 struct xlog_in_core *iclog)
3477{
3478 assert_spin_locked(&log->l_icloglock);
3479
3480 if (iclog->ic_state == XLOG_STATE_ACTIVE) {
3481 xlog_state_switch_iclogs(log, iclog, 0);
3482 } else {
3483 ASSERT(iclog->ic_state &
3484 (XLOG_STATE_WANT_SYNC|XLOG_STATE_IOERROR));
3485 }
3486}
3487
3488
3489/*****************************************************************************
3490 *
3491 * TICKET functions
3492 *
3493 *****************************************************************************
3494 */
3495
3496/*
3497 * Free a used ticket when its refcount falls to zero.
3498 */
3499void
3500xfs_log_ticket_put(
3501 xlog_ticket_t *ticket)
3502{
3503 ASSERT(atomic_read(&ticket->t_ref) > 0);
3504 if (atomic_dec_and_test(&ticket->t_ref))
3505 kmem_zone_free(xfs_log_ticket_zone, ticket);
3506}
3507
3508xlog_ticket_t *
3509xfs_log_ticket_get(
3510 xlog_ticket_t *ticket)
3511{
3512 ASSERT(atomic_read(&ticket->t_ref) > 0);
3513 atomic_inc(&ticket->t_ref);
3514 return ticket;
3515}
3516
3517/*
3518 * Figure out the total log space unit (in bytes) that would be
3519 * required for a log ticket.
3520 */
3521int
3522xfs_log_calc_unit_res(
3523 struct xfs_mount *mp,
3524 int unit_bytes)
3525{
3526 struct xlog *log = mp->m_log;
3527 int iclog_space;
3528 uint num_headers;
3529
3530 /*
3531 * Permanent reservations have up to 'cnt'-1 active log operations
3532 * in the log. A unit in this case is the amount of space for one
3533 * of these log operations. Normal reservations have a cnt of 1
3534 * and their unit amount is the total amount of space required.
3535 *
3536 * The following lines of code account for non-transaction data
3537 * which occupy space in the on-disk log.
3538 *
3539 * Normal form of a transaction is:
3540 * <oph><trans-hdr><start-oph><reg1-oph><reg1><reg2-oph>...<commit-oph>
3541 * and then there are LR hdrs, split-recs and roundoff at end of syncs.
3542 *
3543 * We need to account for all the leadup data and trailer data
3544 * around the transaction data.
3545 * And then we need to account for the worst case in terms of using
3546 * more space.
3547 * The worst case will happen if:
3548 * - the placement of the transaction happens to be such that the
3549 * roundoff is at its maximum
3550 * - the transaction data is synced before the commit record is synced
3551 * i.e. <transaction-data><roundoff> | <commit-rec><roundoff>
3552 * Therefore the commit record is in its own Log Record.
3553 * This can happen as the commit record is called with its
3554 * own region to xlog_write().
3555 * This then means that in the worst case, roundoff can happen for
3556 * the commit-rec as well.
3557 * The commit-rec is smaller than padding in this scenario and so it is
3558 * not added separately.
3559 */
3560
3561 /* for trans header */
3562 unit_bytes += sizeof(xlog_op_header_t);
3563 unit_bytes += sizeof(xfs_trans_header_t);
3564
3565 /* for start-rec */
3566 unit_bytes += sizeof(xlog_op_header_t);
3567
3568 /*
3569 * for LR headers - the space for data in an iclog is the size minus
3570 * the space used for the headers. If we use the iclog size, then we
3571 * undercalculate the number of headers required.
3572 *
3573 * Furthermore - the addition of op headers for split-recs might
3574 * increase the space required enough to require more log and op
3575 * headers, so take that into account too.
3576 *
3577 * IMPORTANT: This reservation makes the assumption that if this
3578 * transaction is the first in an iclog and hence has the LR headers
3579 * accounted to it, then the remaining space in the iclog is
3580 * exclusively for this transaction. i.e. if the transaction is larger
3581 * than the iclog, it will be the only thing in that iclog.
3582 * Fundamentally, this means we must pass the entire log vector to
3583 * xlog_write to guarantee this.
3584 */
3585 iclog_space = log->l_iclog_size - log->l_iclog_hsize;
3586 num_headers = howmany(unit_bytes, iclog_space);
3587
3588 /* for split-recs - ophdrs added when data split over LRs */
3589 unit_bytes += sizeof(xlog_op_header_t) * num_headers;
3590
3591 /* add extra header reservations if we overrun */
3592 while (!num_headers ||
3593 howmany(unit_bytes, iclog_space) > num_headers) {
3594 unit_bytes += sizeof(xlog_op_header_t);
3595 num_headers++;
3596 }
3597 unit_bytes += log->l_iclog_hsize * num_headers;
3598
3599 /* for commit-rec LR header - note: padding will subsume the ophdr */
3600 unit_bytes += log->l_iclog_hsize;
3601
3602 /* for roundoff padding for transaction data and one for commit record */
3603 if (xfs_sb_version_haslogv2(&mp->m_sb) && mp->m_sb.sb_logsunit > 1) {
3604 /* log su roundoff */
3605 unit_bytes += 2 * mp->m_sb.sb_logsunit;
3606 } else {
3607 /* BB roundoff */
3608 unit_bytes += 2 * BBSIZE;
3609 }
3610
3611 return unit_bytes;
3612}
3613
3614/*
3615 * Allocate and initialise a new log ticket.
3616 */
3617struct xlog_ticket *
3618xlog_ticket_alloc(
3619 struct xlog *log,
3620 int unit_bytes,
3621 int cnt,
3622 char client,
3623 bool permanent,
3624 xfs_km_flags_t alloc_flags)
3625{
3626 struct xlog_ticket *tic;
3627 int unit_res;
3628
3629 tic = kmem_zone_zalloc(xfs_log_ticket_zone, alloc_flags);
3630 if (!tic)
3631 return NULL;
3632
3633 unit_res = xfs_log_calc_unit_res(log->l_mp, unit_bytes);
3634
3635 atomic_set(&tic->t_ref, 1);
3636 tic->t_task = current;
3637 INIT_LIST_HEAD(&tic->t_queue);
3638 tic->t_unit_res = unit_res;
3639 tic->t_curr_res = unit_res;
3640 tic->t_cnt = cnt;
3641 tic->t_ocnt = cnt;
3642 tic->t_tid = prandom_u32();
3643 tic->t_clientid = client;
3644 tic->t_flags = XLOG_TIC_INITED;
3645 if (permanent)
3646 tic->t_flags |= XLOG_TIC_PERM_RESERV;
3647
3648 xlog_tic_reset_res(tic);
3649
3650 return tic;
3651}
3652
3653
3654/******************************************************************************
3655 *
3656 * Log debug routines
3657 *
3658 ******************************************************************************
3659 */
3660#if defined(DEBUG)
3661/*
3662 * Make sure that the destination ptr is within the valid data region of
3663 * one of the iclogs. This uses backup pointers stored in a different
3664 * part of the log in case we trash the log structure.
3665 */
3666void
3667xlog_verify_dest_ptr(
3668 struct xlog *log,
3669 void *ptr)
3670{
3671 int i;
3672 int good_ptr = 0;
3673
3674 for (i = 0; i < log->l_iclog_bufs; i++) {
3675 if (ptr >= log->l_iclog_bak[i] &&
3676 ptr <= log->l_iclog_bak[i] + log->l_iclog_size)
3677 good_ptr++;
3678 }
3679
3680 if (!good_ptr)
3681 xfs_emerg(log->l_mp, "%s: invalid ptr", __func__);
3682}
3683
3684/*
3685 * Check to make sure the grant write head didn't just over lap the tail. If
3686 * the cycles are the same, we can't be overlapping. Otherwise, make sure that
3687 * the cycles differ by exactly one and check the byte count.
3688 *
3689 * This check is run unlocked, so can give false positives. Rather than assert
3690 * on failures, use a warn-once flag and a panic tag to allow the admin to
3691 * determine if they want to panic the machine when such an error occurs. For
3692 * debug kernels this will have the same effect as using an assert but, unlinke
3693 * an assert, it can be turned off at runtime.
3694 */
3695STATIC void
3696xlog_verify_grant_tail(
3697 struct xlog *log)
3698{
3699 int tail_cycle, tail_blocks;
3700 int cycle, space;
3701
3702 xlog_crack_grant_head(&log->l_write_head.grant, &cycle, &space);
3703 xlog_crack_atomic_lsn(&log->l_tail_lsn, &tail_cycle, &tail_blocks);
3704 if (tail_cycle != cycle) {
3705 if (cycle - 1 != tail_cycle &&
3706 !(log->l_flags & XLOG_TAIL_WARN)) {
3707 xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES,
3708 "%s: cycle - 1 != tail_cycle", __func__);
3709 log->l_flags |= XLOG_TAIL_WARN;
3710 }
3711
3712 if (space > BBTOB(tail_blocks) &&
3713 !(log->l_flags & XLOG_TAIL_WARN)) {
3714 xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES,
3715 "%s: space > BBTOB(tail_blocks)", __func__);
3716 log->l_flags |= XLOG_TAIL_WARN;
3717 }
3718 }
3719}
3720
3721/* check if it will fit */
3722STATIC void
3723xlog_verify_tail_lsn(
3724 struct xlog *log,
3725 struct xlog_in_core *iclog,
3726 xfs_lsn_t tail_lsn)
3727{
3728 int blocks;
3729
3730 if (CYCLE_LSN(tail_lsn) == log->l_prev_cycle) {
3731 blocks =
3732 log->l_logBBsize - (log->l_prev_block - BLOCK_LSN(tail_lsn));
3733 if (blocks < BTOBB(iclog->ic_offset)+BTOBB(log->l_iclog_hsize))
3734 xfs_emerg(log->l_mp, "%s: ran out of log space", __func__);
3735 } else {
3736 ASSERT(CYCLE_LSN(tail_lsn)+1 == log->l_prev_cycle);
3737
3738 if (BLOCK_LSN(tail_lsn) == log->l_prev_block)
3739 xfs_emerg(log->l_mp, "%s: tail wrapped", __func__);
3740
3741 blocks = BLOCK_LSN(tail_lsn) - log->l_prev_block;
3742 if (blocks < BTOBB(iclog->ic_offset) + 1)
3743 xfs_emerg(log->l_mp, "%s: ran out of log space", __func__);
3744 }
3745} /* xlog_verify_tail_lsn */
3746
3747/*
3748 * Perform a number of checks on the iclog before writing to disk.
3749 *
3750 * 1. Make sure the iclogs are still circular
3751 * 2. Make sure we have a good magic number
3752 * 3. Make sure we don't have magic numbers in the data
3753 * 4. Check fields of each log operation header for:
3754 * A. Valid client identifier
3755 * B. tid ptr value falls in valid ptr space (user space code)
3756 * C. Length in log record header is correct according to the
3757 * individual operation headers within record.
3758 * 5. When a bwrite will occur within 5 blocks of the front of the physical
3759 * log, check the preceding blocks of the physical log to make sure all
3760 * the cycle numbers agree with the current cycle number.
3761 */
3762STATIC void
3763xlog_verify_iclog(
3764 struct xlog *log,
3765 struct xlog_in_core *iclog,
3766 int count,
3767 bool syncing)
3768{
3769 xlog_op_header_t *ophead;
3770 xlog_in_core_t *icptr;
3771 xlog_in_core_2_t *xhdr;
3772 void *base_ptr, *ptr, *p;
3773 ptrdiff_t field_offset;
3774 __uint8_t clientid;
3775 int len, i, j, k, op_len;
3776 int idx;
3777
3778 /* check validity of iclog pointers */
3779 spin_lock(&log->l_icloglock);
3780 icptr = log->l_iclog;
3781 for (i = 0; i < log->l_iclog_bufs; i++, icptr = icptr->ic_next)
3782 ASSERT(icptr);
3783
3784 if (icptr != log->l_iclog)
3785 xfs_emerg(log->l_mp, "%s: corrupt iclog ring", __func__);
3786 spin_unlock(&log->l_icloglock);
3787
3788 /* check log magic numbers */
3789 if (iclog->ic_header.h_magicno != cpu_to_be32(XLOG_HEADER_MAGIC_NUM))
3790 xfs_emerg(log->l_mp, "%s: invalid magic num", __func__);
3791
3792 base_ptr = ptr = &iclog->ic_header;
3793 p = &iclog->ic_header;
3794 for (ptr += BBSIZE; ptr < base_ptr + count; ptr += BBSIZE) {
3795 if (*(__be32 *)ptr == cpu_to_be32(XLOG_HEADER_MAGIC_NUM))
3796 xfs_emerg(log->l_mp, "%s: unexpected magic num",
3797 __func__);
3798 }
3799
3800 /* check fields */
3801 len = be32_to_cpu(iclog->ic_header.h_num_logops);
3802 base_ptr = ptr = iclog->ic_datap;
3803 ophead = ptr;
3804 xhdr = iclog->ic_data;
3805 for (i = 0; i < len; i++) {
3806 ophead = ptr;
3807
3808 /* clientid is only 1 byte */
3809 p = &ophead->oh_clientid;
3810 field_offset = p - base_ptr;
3811 if (!syncing || (field_offset & 0x1ff)) {
3812 clientid = ophead->oh_clientid;
3813 } else {
3814 idx = BTOBBT((char *)&ophead->oh_clientid - iclog->ic_datap);
3815 if (idx >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE)) {
3816 j = idx / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3817 k = idx % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3818 clientid = xlog_get_client_id(
3819 xhdr[j].hic_xheader.xh_cycle_data[k]);
3820 } else {
3821 clientid = xlog_get_client_id(
3822 iclog->ic_header.h_cycle_data[idx]);
3823 }
3824 }
3825 if (clientid != XFS_TRANSACTION && clientid != XFS_LOG)
3826 xfs_warn(log->l_mp,
3827 "%s: invalid clientid %d op 0x%p offset 0x%lx",
3828 __func__, clientid, ophead,
3829 (unsigned long)field_offset);
3830
3831 /* check length */
3832 p = &ophead->oh_len;
3833 field_offset = p - base_ptr;
3834 if (!syncing || (field_offset & 0x1ff)) {
3835 op_len = be32_to_cpu(ophead->oh_len);
3836 } else {
3837 idx = BTOBBT((uintptr_t)&ophead->oh_len -
3838 (uintptr_t)iclog->ic_datap);
3839 if (idx >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE)) {
3840 j = idx / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3841 k = idx % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3842 op_len = be32_to_cpu(xhdr[j].hic_xheader.xh_cycle_data[k]);
3843 } else {
3844 op_len = be32_to_cpu(iclog->ic_header.h_cycle_data[idx]);
3845 }
3846 }
3847 ptr += sizeof(xlog_op_header_t) + op_len;
3848 }
3849} /* xlog_verify_iclog */
3850#endif
3851
3852/*
3853 * Mark all iclogs IOERROR. l_icloglock is held by the caller.
3854 */
3855STATIC int
3856xlog_state_ioerror(
3857 struct xlog *log)
3858{
3859 xlog_in_core_t *iclog, *ic;
3860
3861 iclog = log->l_iclog;
3862 if (! (iclog->ic_state & XLOG_STATE_IOERROR)) {
3863 /*
3864 * Mark all the incore logs IOERROR.
3865 * From now on, no log flushes will result.
3866 */
3867 ic = iclog;
3868 do {
3869 ic->ic_state = XLOG_STATE_IOERROR;
3870 ic = ic->ic_next;
3871 } while (ic != iclog);
3872 return 0;
3873 }
3874 /*
3875 * Return non-zero, if state transition has already happened.
3876 */
3877 return 1;
3878}
3879
3880/*
3881 * This is called from xfs_force_shutdown, when we're forcibly
3882 * shutting down the filesystem, typically because of an IO error.
3883 * Our main objectives here are to make sure that:
3884 * a. if !logerror, flush the logs to disk. Anything modified
3885 * after this is ignored.
3886 * b. the filesystem gets marked 'SHUTDOWN' for all interested
3887 * parties to find out, 'atomically'.
3888 * c. those who're sleeping on log reservations, pinned objects and
3889 * other resources get woken up, and be told the bad news.
3890 * d. nothing new gets queued up after (b) and (c) are done.
3891 *
3892 * Note: for the !logerror case we need to flush the regions held in memory out
3893 * to disk first. This needs to be done before the log is marked as shutdown,
3894 * otherwise the iclog writes will fail.
3895 */
3896int
3897xfs_log_force_umount(
3898 struct xfs_mount *mp,
3899 int logerror)
3900{
3901 struct xlog *log;
3902 int retval;
3903
3904 log = mp->m_log;
3905
3906 /*
3907 * If this happens during log recovery, don't worry about
3908 * locking; the log isn't open for business yet.
3909 */
3910 if (!log ||
3911 log->l_flags & XLOG_ACTIVE_RECOVERY) {
3912 mp->m_flags |= XFS_MOUNT_FS_SHUTDOWN;
3913 if (mp->m_sb_bp)
3914 mp->m_sb_bp->b_flags |= XBF_DONE;
3915 return 0;
3916 }
3917
3918 /*
3919 * Somebody could've already done the hard work for us.
3920 * No need to get locks for this.
3921 */
3922 if (logerror && log->l_iclog->ic_state & XLOG_STATE_IOERROR) {
3923 ASSERT(XLOG_FORCED_SHUTDOWN(log));
3924 return 1;
3925 }
3926
3927 /*
3928 * Flush all the completed transactions to disk before marking the log
3929 * being shut down. We need to do it in this order to ensure that
3930 * completed operations are safely on disk before we shut down, and that
3931 * we don't have to issue any buffer IO after the shutdown flags are set
3932 * to guarantee this.
3933 */
3934 if (!logerror)
3935 _xfs_log_force(mp, XFS_LOG_SYNC, NULL);
3936
3937 /*
3938 * mark the filesystem and the as in a shutdown state and wake
3939 * everybody up to tell them the bad news.
3940 */
3941 spin_lock(&log->l_icloglock);
3942 mp->m_flags |= XFS_MOUNT_FS_SHUTDOWN;
3943 if (mp->m_sb_bp)
3944 mp->m_sb_bp->b_flags |= XBF_DONE;
3945
3946 /*
3947 * Mark the log and the iclogs with IO error flags to prevent any
3948 * further log IO from being issued or completed.
3949 */
3950 log->l_flags |= XLOG_IO_ERROR;
3951 retval = xlog_state_ioerror(log);
3952 spin_unlock(&log->l_icloglock);
3953
3954 /*
3955 * We don't want anybody waiting for log reservations after this. That
3956 * means we have to wake up everybody queued up on reserveq as well as
3957 * writeq. In addition, we make sure in xlog_{re}grant_log_space that
3958 * we don't enqueue anything once the SHUTDOWN flag is set, and this
3959 * action is protected by the grant locks.
3960 */
3961 xlog_grant_head_wake_all(&log->l_reserve_head);
3962 xlog_grant_head_wake_all(&log->l_write_head);
3963
3964 /*
3965 * Wake up everybody waiting on xfs_log_force. Wake the CIL push first
3966 * as if the log writes were completed. The abort handling in the log
3967 * item committed callback functions will do this again under lock to
3968 * avoid races.
3969 */
3970 wake_up_all(&log->l_cilp->xc_commit_wait);
3971 xlog_state_do_callback(log, XFS_LI_ABORTED, NULL);
3972
3973#ifdef XFSERRORDEBUG
3974 {
3975 xlog_in_core_t *iclog;
3976
3977 spin_lock(&log->l_icloglock);
3978 iclog = log->l_iclog;
3979 do {
3980 ASSERT(iclog->ic_callback == 0);
3981 iclog = iclog->ic_next;
3982 } while (iclog != log->l_iclog);
3983 spin_unlock(&log->l_icloglock);
3984 }
3985#endif
3986 /* return non-zero if log IOERROR transition had already happened */
3987 return retval;
3988}
3989
3990STATIC int
3991xlog_iclogs_empty(
3992 struct xlog *log)
3993{
3994 xlog_in_core_t *iclog;
3995
3996 iclog = log->l_iclog;
3997 do {
3998 /* endianness does not matter here, zero is zero in
3999 * any language.
4000 */
4001 if (iclog->ic_header.h_num_logops)
4002 return 0;
4003 iclog = iclog->ic_next;
4004 } while (iclog != log->l_iclog);
4005 return 1;
4006}
4007
4008/*
4009 * Verify that an LSN stamped into a piece of metadata is valid. This is
4010 * intended for use in read verifiers on v5 superblocks.
4011 */
4012bool
4013xfs_log_check_lsn(
4014 struct xfs_mount *mp,
4015 xfs_lsn_t lsn)
4016{
4017 struct xlog *log = mp->m_log;
4018 bool valid;
4019
4020 /*
4021 * norecovery mode skips mount-time log processing and unconditionally
4022 * resets the in-core LSN. We can't validate in this mode, but
4023 * modifications are not allowed anyways so just return true.
4024 */
4025 if (mp->m_flags & XFS_MOUNT_NORECOVERY)
4026 return true;
4027
4028 /*
4029 * Some metadata LSNs are initialized to NULL (e.g., the agfl). This is
4030 * handled by recovery and thus safe to ignore here.
4031 */
4032 if (lsn == NULLCOMMITLSN)
4033 return true;
4034
4035 valid = xlog_valid_lsn(mp->m_log, lsn);
4036
4037 /* warn the user about what's gone wrong before verifier failure */
4038 if (!valid) {
4039 spin_lock(&log->l_icloglock);
4040 xfs_warn(mp,
4041"Corruption warning: Metadata has LSN (%d:%d) ahead of current LSN (%d:%d). "
4042"Please unmount and run xfs_repair (>= v4.3) to resolve.",
4043 CYCLE_LSN(lsn), BLOCK_LSN(lsn),
4044 log->l_curr_cycle, log->l_curr_block);
4045 spin_unlock(&log->l_icloglock);
4046 }
4047
4048 return valid;
4049}