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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_errortag.h"
26#include "xfs_error.h"
27#include "xfs_trans.h"
28#include "xfs_trans_priv.h"
29#include "xfs_log.h"
30#include "xfs_log_priv.h"
31#include "xfs_log_recover.h"
32#include "xfs_inode.h"
33#include "xfs_trace.h"
34#include "xfs_fsops.h"
35#include "xfs_cksum.h"
36#include "xfs_sysfs.h"
37#include "xfs_sb.h"
38
39kmem_zone_t *xfs_log_ticket_zone;
40
41/* Local miscellaneous function prototypes */
42STATIC int
43xlog_commit_record(
44 struct xlog *log,
45 struct xlog_ticket *ticket,
46 struct xlog_in_core **iclog,
47 xfs_lsn_t *commitlsnp);
48
49STATIC struct xlog *
50xlog_alloc_log(
51 struct xfs_mount *mp,
52 struct xfs_buftarg *log_target,
53 xfs_daddr_t blk_offset,
54 int num_bblks);
55STATIC int
56xlog_space_left(
57 struct xlog *log,
58 atomic64_t *head);
59STATIC int
60xlog_sync(
61 struct xlog *log,
62 struct xlog_in_core *iclog);
63STATIC void
64xlog_dealloc_log(
65 struct xlog *log);
66
67/* local state machine functions */
68STATIC void xlog_state_done_syncing(xlog_in_core_t *iclog, int);
69STATIC void
70xlog_state_do_callback(
71 struct xlog *log,
72 int aborted,
73 struct xlog_in_core *iclog);
74STATIC int
75xlog_state_get_iclog_space(
76 struct xlog *log,
77 int len,
78 struct xlog_in_core **iclog,
79 struct xlog_ticket *ticket,
80 int *continued_write,
81 int *logoffsetp);
82STATIC int
83xlog_state_release_iclog(
84 struct xlog *log,
85 struct xlog_in_core *iclog);
86STATIC void
87xlog_state_switch_iclogs(
88 struct xlog *log,
89 struct xlog_in_core *iclog,
90 int eventual_size);
91STATIC void
92xlog_state_want_sync(
93 struct xlog *log,
94 struct xlog_in_core *iclog);
95
96STATIC void
97xlog_grant_push_ail(
98 struct xlog *log,
99 int need_bytes);
100STATIC void
101xlog_regrant_reserve_log_space(
102 struct xlog *log,
103 struct xlog_ticket *ticket);
104STATIC void
105xlog_ungrant_log_space(
106 struct xlog *log,
107 struct xlog_ticket *ticket);
108
109#if defined(DEBUG)
110STATIC void
111xlog_verify_dest_ptr(
112 struct xlog *log,
113 void *ptr);
114STATIC void
115xlog_verify_grant_tail(
116 struct xlog *log);
117STATIC void
118xlog_verify_iclog(
119 struct xlog *log,
120 struct xlog_in_core *iclog,
121 int count,
122 bool syncing);
123STATIC void
124xlog_verify_tail_lsn(
125 struct xlog *log,
126 struct xlog_in_core *iclog,
127 xfs_lsn_t tail_lsn);
128#else
129#define xlog_verify_dest_ptr(a,b)
130#define xlog_verify_grant_tail(a)
131#define xlog_verify_iclog(a,b,c,d)
132#define xlog_verify_tail_lsn(a,b,c)
133#endif
134
135STATIC int
136xlog_iclogs_empty(
137 struct xlog *log);
138
139static void
140xlog_grant_sub_space(
141 struct xlog *log,
142 atomic64_t *head,
143 int bytes)
144{
145 int64_t head_val = atomic64_read(head);
146 int64_t new, old;
147
148 do {
149 int cycle, space;
150
151 xlog_crack_grant_head_val(head_val, &cycle, &space);
152
153 space -= bytes;
154 if (space < 0) {
155 space += log->l_logsize;
156 cycle--;
157 }
158
159 old = head_val;
160 new = xlog_assign_grant_head_val(cycle, space);
161 head_val = atomic64_cmpxchg(head, old, new);
162 } while (head_val != old);
163}
164
165static void
166xlog_grant_add_space(
167 struct xlog *log,
168 atomic64_t *head,
169 int bytes)
170{
171 int64_t head_val = atomic64_read(head);
172 int64_t new, old;
173
174 do {
175 int tmp;
176 int cycle, space;
177
178 xlog_crack_grant_head_val(head_val, &cycle, &space);
179
180 tmp = log->l_logsize - space;
181 if (tmp > bytes)
182 space += bytes;
183 else {
184 space = bytes - tmp;
185 cycle++;
186 }
187
188 old = head_val;
189 new = xlog_assign_grant_head_val(cycle, space);
190 head_val = atomic64_cmpxchg(head, old, new);
191 } while (head_val != old);
192}
193
194STATIC void
195xlog_grant_head_init(
196 struct xlog_grant_head *head)
197{
198 xlog_assign_grant_head(&head->grant, 1, 0);
199 INIT_LIST_HEAD(&head->waiters);
200 spin_lock_init(&head->lock);
201}
202
203STATIC void
204xlog_grant_head_wake_all(
205 struct xlog_grant_head *head)
206{
207 struct xlog_ticket *tic;
208
209 spin_lock(&head->lock);
210 list_for_each_entry(tic, &head->waiters, t_queue)
211 wake_up_process(tic->t_task);
212 spin_unlock(&head->lock);
213}
214
215static inline int
216xlog_ticket_reservation(
217 struct xlog *log,
218 struct xlog_grant_head *head,
219 struct xlog_ticket *tic)
220{
221 if (head == &log->l_write_head) {
222 ASSERT(tic->t_flags & XLOG_TIC_PERM_RESERV);
223 return tic->t_unit_res;
224 } else {
225 if (tic->t_flags & XLOG_TIC_PERM_RESERV)
226 return tic->t_unit_res * tic->t_cnt;
227 else
228 return tic->t_unit_res;
229 }
230}
231
232STATIC bool
233xlog_grant_head_wake(
234 struct xlog *log,
235 struct xlog_grant_head *head,
236 int *free_bytes)
237{
238 struct xlog_ticket *tic;
239 int need_bytes;
240
241 list_for_each_entry(tic, &head->waiters, t_queue) {
242 need_bytes = xlog_ticket_reservation(log, head, tic);
243 if (*free_bytes < need_bytes)
244 return false;
245
246 *free_bytes -= need_bytes;
247 trace_xfs_log_grant_wake_up(log, tic);
248 wake_up_process(tic->t_task);
249 }
250
251 return true;
252}
253
254STATIC int
255xlog_grant_head_wait(
256 struct xlog *log,
257 struct xlog_grant_head *head,
258 struct xlog_ticket *tic,
259 int need_bytes) __releases(&head->lock)
260 __acquires(&head->lock)
261{
262 list_add_tail(&tic->t_queue, &head->waiters);
263
264 do {
265 if (XLOG_FORCED_SHUTDOWN(log))
266 goto shutdown;
267 xlog_grant_push_ail(log, need_bytes);
268
269 __set_current_state(TASK_UNINTERRUPTIBLE);
270 spin_unlock(&head->lock);
271
272 XFS_STATS_INC(log->l_mp, xs_sleep_logspace);
273
274 trace_xfs_log_grant_sleep(log, tic);
275 schedule();
276 trace_xfs_log_grant_wake(log, tic);
277
278 spin_lock(&head->lock);
279 if (XLOG_FORCED_SHUTDOWN(log))
280 goto shutdown;
281 } while (xlog_space_left(log, &head->grant) < need_bytes);
282
283 list_del_init(&tic->t_queue);
284 return 0;
285shutdown:
286 list_del_init(&tic->t_queue);
287 return -EIO;
288}
289
290/*
291 * Atomically get the log space required for a log ticket.
292 *
293 * Once a ticket gets put onto head->waiters, it will only return after the
294 * needed reservation is satisfied.
295 *
296 * This function is structured so that it has a lock free fast path. This is
297 * necessary because every new transaction reservation will come through this
298 * path. Hence any lock will be globally hot if we take it unconditionally on
299 * every pass.
300 *
301 * As tickets are only ever moved on and off head->waiters under head->lock, we
302 * only need to take that lock if we are going to add the ticket to the queue
303 * and sleep. We can avoid taking the lock if the ticket was never added to
304 * head->waiters because the t_queue list head will be empty and we hold the
305 * only reference to it so it can safely be checked unlocked.
306 */
307STATIC int
308xlog_grant_head_check(
309 struct xlog *log,
310 struct xlog_grant_head *head,
311 struct xlog_ticket *tic,
312 int *need_bytes)
313{
314 int free_bytes;
315 int error = 0;
316
317 ASSERT(!(log->l_flags & XLOG_ACTIVE_RECOVERY));
318
319 /*
320 * If there are other waiters on the queue then give them a chance at
321 * logspace before us. Wake up the first waiters, if we do not wake
322 * up all the waiters then go to sleep waiting for more free space,
323 * otherwise try to get some space for this transaction.
324 */
325 *need_bytes = xlog_ticket_reservation(log, head, tic);
326 free_bytes = xlog_space_left(log, &head->grant);
327 if (!list_empty_careful(&head->waiters)) {
328 spin_lock(&head->lock);
329 if (!xlog_grant_head_wake(log, head, &free_bytes) ||
330 free_bytes < *need_bytes) {
331 error = xlog_grant_head_wait(log, head, tic,
332 *need_bytes);
333 }
334 spin_unlock(&head->lock);
335 } else if (free_bytes < *need_bytes) {
336 spin_lock(&head->lock);
337 error = xlog_grant_head_wait(log, head, tic, *need_bytes);
338 spin_unlock(&head->lock);
339 }
340
341 return error;
342}
343
344static void
345xlog_tic_reset_res(xlog_ticket_t *tic)
346{
347 tic->t_res_num = 0;
348 tic->t_res_arr_sum = 0;
349 tic->t_res_num_ophdrs = 0;
350}
351
352static void
353xlog_tic_add_region(xlog_ticket_t *tic, uint len, uint type)
354{
355 if (tic->t_res_num == XLOG_TIC_LEN_MAX) {
356 /* add to overflow and start again */
357 tic->t_res_o_flow += tic->t_res_arr_sum;
358 tic->t_res_num = 0;
359 tic->t_res_arr_sum = 0;
360 }
361
362 tic->t_res_arr[tic->t_res_num].r_len = len;
363 tic->t_res_arr[tic->t_res_num].r_type = type;
364 tic->t_res_arr_sum += len;
365 tic->t_res_num++;
366}
367
368/*
369 * Replenish the byte reservation required by moving the grant write head.
370 */
371int
372xfs_log_regrant(
373 struct xfs_mount *mp,
374 struct xlog_ticket *tic)
375{
376 struct xlog *log = mp->m_log;
377 int need_bytes;
378 int error = 0;
379
380 if (XLOG_FORCED_SHUTDOWN(log))
381 return -EIO;
382
383 XFS_STATS_INC(mp, xs_try_logspace);
384
385 /*
386 * This is a new transaction on the ticket, so we need to change the
387 * transaction ID so that the next transaction has a different TID in
388 * the log. Just add one to the existing tid so that we can see chains
389 * of rolling transactions in the log easily.
390 */
391 tic->t_tid++;
392
393 xlog_grant_push_ail(log, tic->t_unit_res);
394
395 tic->t_curr_res = tic->t_unit_res;
396 xlog_tic_reset_res(tic);
397
398 if (tic->t_cnt > 0)
399 return 0;
400
401 trace_xfs_log_regrant(log, tic);
402
403 error = xlog_grant_head_check(log, &log->l_write_head, tic,
404 &need_bytes);
405 if (error)
406 goto out_error;
407
408 xlog_grant_add_space(log, &log->l_write_head.grant, need_bytes);
409 trace_xfs_log_regrant_exit(log, tic);
410 xlog_verify_grant_tail(log);
411 return 0;
412
413out_error:
414 /*
415 * If we are failing, make sure the ticket doesn't have any current
416 * reservations. We don't want to add this back when the ticket/
417 * transaction gets cancelled.
418 */
419 tic->t_curr_res = 0;
420 tic->t_cnt = 0; /* ungrant will give back unit_res * t_cnt. */
421 return error;
422}
423
424/*
425 * Reserve log space and return a ticket corresponding the reservation.
426 *
427 * Each reservation is going to reserve extra space for a log record header.
428 * When writes happen to the on-disk log, we don't subtract the length of the
429 * log record header from any reservation. By wasting space in each
430 * reservation, we prevent over allocation problems.
431 */
432int
433xfs_log_reserve(
434 struct xfs_mount *mp,
435 int unit_bytes,
436 int cnt,
437 struct xlog_ticket **ticp,
438 uint8_t client,
439 bool permanent)
440{
441 struct xlog *log = mp->m_log;
442 struct xlog_ticket *tic;
443 int need_bytes;
444 int error = 0;
445
446 ASSERT(client == XFS_TRANSACTION || client == XFS_LOG);
447
448 if (XLOG_FORCED_SHUTDOWN(log))
449 return -EIO;
450
451 XFS_STATS_INC(mp, xs_try_logspace);
452
453 ASSERT(*ticp == NULL);
454 tic = xlog_ticket_alloc(log, unit_bytes, cnt, client, permanent,
455 KM_SLEEP | KM_MAYFAIL);
456 if (!tic)
457 return -ENOMEM;
458
459 *ticp = tic;
460
461 xlog_grant_push_ail(log, tic->t_cnt ? tic->t_unit_res * tic->t_cnt
462 : tic->t_unit_res);
463
464 trace_xfs_log_reserve(log, tic);
465
466 error = xlog_grant_head_check(log, &log->l_reserve_head, tic,
467 &need_bytes);
468 if (error)
469 goto out_error;
470
471 xlog_grant_add_space(log, &log->l_reserve_head.grant, need_bytes);
472 xlog_grant_add_space(log, &log->l_write_head.grant, need_bytes);
473 trace_xfs_log_reserve_exit(log, tic);
474 xlog_verify_grant_tail(log);
475 return 0;
476
477out_error:
478 /*
479 * If we are failing, make sure the ticket doesn't have any current
480 * reservations. We don't want to add this back when the ticket/
481 * transaction gets cancelled.
482 */
483 tic->t_curr_res = 0;
484 tic->t_cnt = 0; /* ungrant will give back unit_res * t_cnt. */
485 return error;
486}
487
488
489/*
490 * NOTES:
491 *
492 * 1. currblock field gets updated at startup and after in-core logs
493 * marked as with WANT_SYNC.
494 */
495
496/*
497 * This routine is called when a user of a log manager ticket is done with
498 * the reservation. If the ticket was ever used, then a commit record for
499 * the associated transaction is written out as a log operation header with
500 * no data. The flag XLOG_TIC_INITED is set when the first write occurs with
501 * a given ticket. If the ticket was one with a permanent reservation, then
502 * a few operations are done differently. Permanent reservation tickets by
503 * default don't release the reservation. They just commit the current
504 * transaction with the belief that the reservation is still needed. A flag
505 * must be passed in before permanent reservations are actually released.
506 * When these type of tickets are not released, they need to be set into
507 * the inited state again. By doing this, a start record will be written
508 * out when the next write occurs.
509 */
510xfs_lsn_t
511xfs_log_done(
512 struct xfs_mount *mp,
513 struct xlog_ticket *ticket,
514 struct xlog_in_core **iclog,
515 bool regrant)
516{
517 struct xlog *log = mp->m_log;
518 xfs_lsn_t lsn = 0;
519
520 if (XLOG_FORCED_SHUTDOWN(log) ||
521 /*
522 * If nothing was ever written, don't write out commit record.
523 * If we get an error, just continue and give back the log ticket.
524 */
525 (((ticket->t_flags & XLOG_TIC_INITED) == 0) &&
526 (xlog_commit_record(log, ticket, iclog, &lsn)))) {
527 lsn = (xfs_lsn_t) -1;
528 regrant = false;
529 }
530
531
532 if (!regrant) {
533 trace_xfs_log_done_nonperm(log, ticket);
534
535 /*
536 * Release ticket if not permanent reservation or a specific
537 * request has been made to release a permanent reservation.
538 */
539 xlog_ungrant_log_space(log, ticket);
540 } else {
541 trace_xfs_log_done_perm(log, ticket);
542
543 xlog_regrant_reserve_log_space(log, ticket);
544 /* If this ticket was a permanent reservation and we aren't
545 * trying to release it, reset the inited flags; so next time
546 * we write, a start record will be written out.
547 */
548 ticket->t_flags |= XLOG_TIC_INITED;
549 }
550
551 xfs_log_ticket_put(ticket);
552 return lsn;
553}
554
555/*
556 * Attaches a new iclog I/O completion callback routine during
557 * transaction commit. If the log is in error state, a non-zero
558 * return code is handed back and the caller is responsible for
559 * executing the callback at an appropriate time.
560 */
561int
562xfs_log_notify(
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 bool fatal = xfs_sb_version_hascrc(&mp->m_sb);
612 int error = 0;
613 int min_logfsbs;
614
615 if (!(mp->m_flags & XFS_MOUNT_NORECOVERY)) {
616 xfs_notice(mp, "Mounting V%d Filesystem",
617 XFS_SB_VERSION_NUM(&mp->m_sb));
618 } else {
619 xfs_notice(mp,
620"Mounting V%d filesystem in no-recovery mode. Filesystem will be inconsistent.",
621 XFS_SB_VERSION_NUM(&mp->m_sb));
622 ASSERT(mp->m_flags & XFS_MOUNT_RDONLY);
623 }
624
625 mp->m_log = xlog_alloc_log(mp, log_target, blk_offset, num_bblks);
626 if (IS_ERR(mp->m_log)) {
627 error = PTR_ERR(mp->m_log);
628 goto out;
629 }
630
631 /*
632 * Validate the given log space and drop a critical message via syslog
633 * if the log size is too small that would lead to some unexpected
634 * situations in transaction log space reservation stage.
635 *
636 * Note: we can't just reject the mount if the validation fails. This
637 * would mean that people would have to downgrade their kernel just to
638 * remedy the situation as there is no way to grow the log (short of
639 * black magic surgery with xfs_db).
640 *
641 * We can, however, reject mounts for CRC format filesystems, as the
642 * mkfs binary being used to make the filesystem should never create a
643 * filesystem with a log that is too small.
644 */
645 min_logfsbs = xfs_log_calc_minimum_size(mp);
646
647 if (mp->m_sb.sb_logblocks < min_logfsbs) {
648 xfs_warn(mp,
649 "Log size %d blocks too small, minimum size is %d blocks",
650 mp->m_sb.sb_logblocks, min_logfsbs);
651 error = -EINVAL;
652 } else if (mp->m_sb.sb_logblocks > XFS_MAX_LOG_BLOCKS) {
653 xfs_warn(mp,
654 "Log size %d blocks too large, maximum size is %lld blocks",
655 mp->m_sb.sb_logblocks, XFS_MAX_LOG_BLOCKS);
656 error = -EINVAL;
657 } else if (XFS_FSB_TO_B(mp, mp->m_sb.sb_logblocks) > XFS_MAX_LOG_BYTES) {
658 xfs_warn(mp,
659 "log size %lld bytes too large, maximum size is %lld bytes",
660 XFS_FSB_TO_B(mp, mp->m_sb.sb_logblocks),
661 XFS_MAX_LOG_BYTES);
662 error = -EINVAL;
663 } else if (mp->m_sb.sb_logsunit > 1 &&
664 mp->m_sb.sb_logsunit % mp->m_sb.sb_blocksize) {
665 xfs_warn(mp,
666 "log stripe unit %u bytes must be a multiple of block size",
667 mp->m_sb.sb_logsunit);
668 error = -EINVAL;
669 fatal = true;
670 }
671 if (error) {
672 /*
673 * Log check errors are always fatal on v5; or whenever bad
674 * metadata leads to a crash.
675 */
676 if (fatal) {
677 xfs_crit(mp, "AAIEEE! Log failed size checks. Abort!");
678 ASSERT(0);
679 goto out_free_log;
680 }
681 xfs_crit(mp, "Log size out of supported range.");
682 xfs_crit(mp,
683"Continuing onwards, but if log hangs are experienced then please report this message in the bug report.");
684 }
685
686 /*
687 * Initialize the AIL now we have a log.
688 */
689 error = xfs_trans_ail_init(mp);
690 if (error) {
691 xfs_warn(mp, "AIL initialisation failed: error %d", error);
692 goto out_free_log;
693 }
694 mp->m_log->l_ailp = mp->m_ail;
695
696 /*
697 * skip log recovery on a norecovery mount. pretend it all
698 * just worked.
699 */
700 if (!(mp->m_flags & XFS_MOUNT_NORECOVERY)) {
701 int readonly = (mp->m_flags & XFS_MOUNT_RDONLY);
702
703 if (readonly)
704 mp->m_flags &= ~XFS_MOUNT_RDONLY;
705
706 error = xlog_recover(mp->m_log);
707
708 if (readonly)
709 mp->m_flags |= XFS_MOUNT_RDONLY;
710 if (error) {
711 xfs_warn(mp, "log mount/recovery failed: error %d",
712 error);
713 xlog_recover_cancel(mp->m_log);
714 goto out_destroy_ail;
715 }
716 }
717
718 error = xfs_sysfs_init(&mp->m_log->l_kobj, &xfs_log_ktype, &mp->m_kobj,
719 "log");
720 if (error)
721 goto out_destroy_ail;
722
723 /* Normal transactions can now occur */
724 mp->m_log->l_flags &= ~XLOG_ACTIVE_RECOVERY;
725
726 /*
727 * Now the log has been fully initialised and we know were our
728 * space grant counters are, we can initialise the permanent ticket
729 * needed for delayed logging to work.
730 */
731 xlog_cil_init_post_recovery(mp->m_log);
732
733 return 0;
734
735out_destroy_ail:
736 xfs_trans_ail_destroy(mp);
737out_free_log:
738 xlog_dealloc_log(mp->m_log);
739out:
740 return error;
741}
742
743/*
744 * Finish the recovery of the file system. This is separate from the
745 * xfs_log_mount() call, because it depends on the code in xfs_mountfs() to read
746 * in the root and real-time bitmap inodes between calling xfs_log_mount() and
747 * here.
748 *
749 * If we finish recovery successfully, start the background log work. If we are
750 * not doing recovery, then we have a RO filesystem and we don't need to start
751 * it.
752 */
753int
754xfs_log_mount_finish(
755 struct xfs_mount *mp)
756{
757 int error = 0;
758 bool readonly = (mp->m_flags & XFS_MOUNT_RDONLY);
759 bool recovered = mp->m_log->l_flags & XLOG_RECOVERY_NEEDED;
760
761 if (mp->m_flags & XFS_MOUNT_NORECOVERY) {
762 ASSERT(mp->m_flags & XFS_MOUNT_RDONLY);
763 return 0;
764 } else if (readonly) {
765 /* Allow unlinked processing to proceed */
766 mp->m_flags &= ~XFS_MOUNT_RDONLY;
767 }
768
769 /*
770 * During the second phase of log recovery, we need iget and
771 * iput to behave like they do for an active filesystem.
772 * xfs_fs_drop_inode needs to be able to prevent the deletion
773 * of inodes before we're done replaying log items on those
774 * inodes. Turn it off immediately after recovery finishes
775 * so that we don't leak the quota inodes if subsequent mount
776 * activities fail.
777 *
778 * We let all inodes involved in redo item processing end up on
779 * the LRU instead of being evicted immediately so that if we do
780 * something to an unlinked inode, the irele won't cause
781 * premature truncation and freeing of the inode, which results
782 * in log recovery failure. We have to evict the unreferenced
783 * lru inodes after clearing SB_ACTIVE because we don't
784 * otherwise clean up the lru if there's a subsequent failure in
785 * xfs_mountfs, which leads to us leaking the inodes if nothing
786 * else (e.g. quotacheck) references the inodes before the
787 * mount failure occurs.
788 */
789 mp->m_super->s_flags |= SB_ACTIVE;
790 error = xlog_recover_finish(mp->m_log);
791 if (!error)
792 xfs_log_work_queue(mp);
793 mp->m_super->s_flags &= ~SB_ACTIVE;
794 evict_inodes(mp->m_super);
795
796 /*
797 * Drain the buffer LRU after log recovery. This is required for v4
798 * filesystems to avoid leaving around buffers with NULL verifier ops,
799 * but we do it unconditionally to make sure we're always in a clean
800 * cache state after mount.
801 *
802 * Don't push in the error case because the AIL may have pending intents
803 * that aren't removed until recovery is cancelled.
804 */
805 if (!error && recovered) {
806 xfs_log_force(mp, XFS_LOG_SYNC);
807 xfs_ail_push_all_sync(mp->m_ail);
808 }
809 xfs_wait_buftarg(mp->m_ddev_targp);
810
811 if (readonly)
812 mp->m_flags |= XFS_MOUNT_RDONLY;
813
814 return error;
815}
816
817/*
818 * The mount has failed. Cancel the recovery if it hasn't completed and destroy
819 * the log.
820 */
821int
822xfs_log_mount_cancel(
823 struct xfs_mount *mp)
824{
825 int error;
826
827 error = xlog_recover_cancel(mp->m_log);
828 xfs_log_unmount(mp);
829
830 return error;
831}
832
833/*
834 * Final log writes as part of unmount.
835 *
836 * Mark the filesystem clean as unmount happens. Note that during relocation
837 * this routine needs to be executed as part of source-bag while the
838 * deallocation must not be done until source-end.
839 */
840
841/*
842 * Unmount record used to have a string "Unmount filesystem--" in the
843 * data section where the "Un" was really a magic number (XLOG_UNMOUNT_TYPE).
844 * We just write the magic number now since that particular field isn't
845 * currently architecture converted and "Unmount" is a bit foo.
846 * As far as I know, there weren't any dependencies on the old behaviour.
847 */
848
849static int
850xfs_log_unmount_write(xfs_mount_t *mp)
851{
852 struct xlog *log = mp->m_log;
853 xlog_in_core_t *iclog;
854#ifdef DEBUG
855 xlog_in_core_t *first_iclog;
856#endif
857 xlog_ticket_t *tic = NULL;
858 xfs_lsn_t lsn;
859 int error;
860
861 /*
862 * Don't write out unmount record on norecovery mounts or ro devices.
863 * Or, if we are doing a forced umount (typically because of IO errors).
864 */
865 if (mp->m_flags & XFS_MOUNT_NORECOVERY ||
866 xfs_readonly_buftarg(log->l_mp->m_logdev_targp)) {
867 ASSERT(mp->m_flags & XFS_MOUNT_RDONLY);
868 return 0;
869 }
870
871 error = xfs_log_force(mp, XFS_LOG_SYNC);
872 ASSERT(error || !(XLOG_FORCED_SHUTDOWN(log)));
873
874#ifdef DEBUG
875 first_iclog = iclog = log->l_iclog;
876 do {
877 if (!(iclog->ic_state & XLOG_STATE_IOERROR)) {
878 ASSERT(iclog->ic_state & XLOG_STATE_ACTIVE);
879 ASSERT(iclog->ic_offset == 0);
880 }
881 iclog = iclog->ic_next;
882 } while (iclog != first_iclog);
883#endif
884 if (! (XLOG_FORCED_SHUTDOWN(log))) {
885 error = xfs_log_reserve(mp, 600, 1, &tic, XFS_LOG, 0);
886 if (!error) {
887 /* the data section must be 32 bit size aligned */
888 struct {
889 uint16_t magic;
890 uint16_t pad1;
891 uint32_t pad2; /* may as well make it 64 bits */
892 } magic = {
893 .magic = XLOG_UNMOUNT_TYPE,
894 };
895 struct xfs_log_iovec reg = {
896 .i_addr = &magic,
897 .i_len = sizeof(magic),
898 .i_type = XLOG_REG_TYPE_UNMOUNT,
899 };
900 struct xfs_log_vec vec = {
901 .lv_niovecs = 1,
902 .lv_iovecp = ®,
903 };
904
905 /* remove inited flag, and account for space used */
906 tic->t_flags = 0;
907 tic->t_curr_res -= sizeof(magic);
908 error = xlog_write(log, &vec, tic, &lsn,
909 NULL, XLOG_UNMOUNT_TRANS);
910 /*
911 * At this point, we're umounting anyway,
912 * so there's no point in transitioning log state
913 * to IOERROR. Just continue...
914 */
915 }
916
917 if (error)
918 xfs_alert(mp, "%s: unmount record failed", __func__);
919
920
921 spin_lock(&log->l_icloglock);
922 iclog = log->l_iclog;
923 atomic_inc(&iclog->ic_refcnt);
924 xlog_state_want_sync(log, iclog);
925 spin_unlock(&log->l_icloglock);
926 error = xlog_state_release_iclog(log, iclog);
927
928 spin_lock(&log->l_icloglock);
929 if (!(iclog->ic_state == XLOG_STATE_ACTIVE ||
930 iclog->ic_state == XLOG_STATE_DIRTY)) {
931 if (!XLOG_FORCED_SHUTDOWN(log)) {
932 xlog_wait(&iclog->ic_force_wait,
933 &log->l_icloglock);
934 } else {
935 spin_unlock(&log->l_icloglock);
936 }
937 } else {
938 spin_unlock(&log->l_icloglock);
939 }
940 if (tic) {
941 trace_xfs_log_umount_write(log, tic);
942 xlog_ungrant_log_space(log, tic);
943 xfs_log_ticket_put(tic);
944 }
945 } else {
946 /*
947 * We're already in forced_shutdown mode, couldn't
948 * even attempt to write out the unmount transaction.
949 *
950 * Go through the motions of sync'ing and releasing
951 * the iclog, even though no I/O will actually happen,
952 * we need to wait for other log I/Os that may already
953 * be in progress. Do this as a separate section of
954 * code so we'll know if we ever get stuck here that
955 * we're in this odd situation of trying to unmount
956 * a file system that went into forced_shutdown as
957 * the result of an unmount..
958 */
959 spin_lock(&log->l_icloglock);
960 iclog = log->l_iclog;
961 atomic_inc(&iclog->ic_refcnt);
962
963 xlog_state_want_sync(log, iclog);
964 spin_unlock(&log->l_icloglock);
965 error = xlog_state_release_iclog(log, iclog);
966
967 spin_lock(&log->l_icloglock);
968
969 if ( ! ( iclog->ic_state == XLOG_STATE_ACTIVE
970 || iclog->ic_state == XLOG_STATE_DIRTY
971 || iclog->ic_state == XLOG_STATE_IOERROR) ) {
972
973 xlog_wait(&iclog->ic_force_wait,
974 &log->l_icloglock);
975 } else {
976 spin_unlock(&log->l_icloglock);
977 }
978 }
979
980 return error;
981} /* xfs_log_unmount_write */
982
983/*
984 * Empty the log for unmount/freeze.
985 *
986 * To do this, we first need to shut down the background log work so it is not
987 * trying to cover the log as we clean up. We then need to unpin all objects in
988 * the log so we can then flush them out. Once they have completed their IO and
989 * run the callbacks removing themselves from the AIL, we can write the unmount
990 * record.
991 */
992void
993xfs_log_quiesce(
994 struct xfs_mount *mp)
995{
996 cancel_delayed_work_sync(&mp->m_log->l_work);
997 xfs_log_force(mp, XFS_LOG_SYNC);
998
999 /*
1000 * The superblock buffer is uncached and while xfs_ail_push_all_sync()
1001 * will push it, xfs_wait_buftarg() will not wait for it. Further,
1002 * xfs_buf_iowait() cannot be used because it was pushed with the
1003 * XBF_ASYNC flag set, so we need to use a lock/unlock pair to wait for
1004 * the IO to complete.
1005 */
1006 xfs_ail_push_all_sync(mp->m_ail);
1007 xfs_wait_buftarg(mp->m_ddev_targp);
1008 xfs_buf_lock(mp->m_sb_bp);
1009 xfs_buf_unlock(mp->m_sb_bp);
1010
1011 xfs_log_unmount_write(mp);
1012}
1013
1014/*
1015 * Shut down and release the AIL and Log.
1016 *
1017 * During unmount, we need to ensure we flush all the dirty metadata objects
1018 * from the AIL so that the log is empty before we write the unmount record to
1019 * the log. Once this is done, we can tear down the AIL and the log.
1020 */
1021void
1022xfs_log_unmount(
1023 struct xfs_mount *mp)
1024{
1025 xfs_log_quiesce(mp);
1026
1027 xfs_trans_ail_destroy(mp);
1028
1029 xfs_sysfs_del(&mp->m_log->l_kobj);
1030
1031 xlog_dealloc_log(mp->m_log);
1032}
1033
1034void
1035xfs_log_item_init(
1036 struct xfs_mount *mp,
1037 struct xfs_log_item *item,
1038 int type,
1039 const struct xfs_item_ops *ops)
1040{
1041 item->li_mountp = mp;
1042 item->li_ailp = mp->m_ail;
1043 item->li_type = type;
1044 item->li_ops = ops;
1045 item->li_lv = NULL;
1046
1047 INIT_LIST_HEAD(&item->li_ail);
1048 INIT_LIST_HEAD(&item->li_cil);
1049 INIT_LIST_HEAD(&item->li_bio_list);
1050}
1051
1052/*
1053 * Wake up processes waiting for log space after we have moved the log tail.
1054 */
1055void
1056xfs_log_space_wake(
1057 struct xfs_mount *mp)
1058{
1059 struct xlog *log = mp->m_log;
1060 int free_bytes;
1061
1062 if (XLOG_FORCED_SHUTDOWN(log))
1063 return;
1064
1065 if (!list_empty_careful(&log->l_write_head.waiters)) {
1066 ASSERT(!(log->l_flags & XLOG_ACTIVE_RECOVERY));
1067
1068 spin_lock(&log->l_write_head.lock);
1069 free_bytes = xlog_space_left(log, &log->l_write_head.grant);
1070 xlog_grant_head_wake(log, &log->l_write_head, &free_bytes);
1071 spin_unlock(&log->l_write_head.lock);
1072 }
1073
1074 if (!list_empty_careful(&log->l_reserve_head.waiters)) {
1075 ASSERT(!(log->l_flags & XLOG_ACTIVE_RECOVERY));
1076
1077 spin_lock(&log->l_reserve_head.lock);
1078 free_bytes = xlog_space_left(log, &log->l_reserve_head.grant);
1079 xlog_grant_head_wake(log, &log->l_reserve_head, &free_bytes);
1080 spin_unlock(&log->l_reserve_head.lock);
1081 }
1082}
1083
1084/*
1085 * Determine if we have a transaction that has gone to disk that needs to be
1086 * covered. To begin the transition to the idle state firstly the log needs to
1087 * be idle. That means the CIL, the AIL and the iclogs needs to be empty before
1088 * we start attempting to cover the log.
1089 *
1090 * Only if we are then in a state where covering is needed, the caller is
1091 * informed that dummy transactions are required to move the log into the idle
1092 * state.
1093 *
1094 * If there are any items in the AIl or CIL, then we do not want to attempt to
1095 * cover the log as we may be in a situation where there isn't log space
1096 * available to run a dummy transaction and this can lead to deadlocks when the
1097 * tail of the log is pinned by an item that is modified in the CIL. Hence
1098 * there's no point in running a dummy transaction at this point because we
1099 * can't start trying to idle the log until both the CIL and AIL are empty.
1100 */
1101static int
1102xfs_log_need_covered(xfs_mount_t *mp)
1103{
1104 struct xlog *log = mp->m_log;
1105 int needed = 0;
1106
1107 if (!xfs_fs_writable(mp, SB_FREEZE_WRITE))
1108 return 0;
1109
1110 if (!xlog_cil_empty(log))
1111 return 0;
1112
1113 spin_lock(&log->l_icloglock);
1114 switch (log->l_covered_state) {
1115 case XLOG_STATE_COVER_DONE:
1116 case XLOG_STATE_COVER_DONE2:
1117 case XLOG_STATE_COVER_IDLE:
1118 break;
1119 case XLOG_STATE_COVER_NEED:
1120 case XLOG_STATE_COVER_NEED2:
1121 if (xfs_ail_min_lsn(log->l_ailp))
1122 break;
1123 if (!xlog_iclogs_empty(log))
1124 break;
1125
1126 needed = 1;
1127 if (log->l_covered_state == XLOG_STATE_COVER_NEED)
1128 log->l_covered_state = XLOG_STATE_COVER_DONE;
1129 else
1130 log->l_covered_state = XLOG_STATE_COVER_DONE2;
1131 break;
1132 default:
1133 needed = 1;
1134 break;
1135 }
1136 spin_unlock(&log->l_icloglock);
1137 return needed;
1138}
1139
1140/*
1141 * We may be holding the log iclog lock upon entering this routine.
1142 */
1143xfs_lsn_t
1144xlog_assign_tail_lsn_locked(
1145 struct xfs_mount *mp)
1146{
1147 struct xlog *log = mp->m_log;
1148 struct xfs_log_item *lip;
1149 xfs_lsn_t tail_lsn;
1150
1151 assert_spin_locked(&mp->m_ail->ail_lock);
1152
1153 /*
1154 * To make sure we always have a valid LSN for the log tail we keep
1155 * track of the last LSN which was committed in log->l_last_sync_lsn,
1156 * and use that when the AIL was empty.
1157 */
1158 lip = xfs_ail_min(mp->m_ail);
1159 if (lip)
1160 tail_lsn = lip->li_lsn;
1161 else
1162 tail_lsn = atomic64_read(&log->l_last_sync_lsn);
1163 trace_xfs_log_assign_tail_lsn(log, tail_lsn);
1164 atomic64_set(&log->l_tail_lsn, tail_lsn);
1165 return tail_lsn;
1166}
1167
1168xfs_lsn_t
1169xlog_assign_tail_lsn(
1170 struct xfs_mount *mp)
1171{
1172 xfs_lsn_t tail_lsn;
1173
1174 spin_lock(&mp->m_ail->ail_lock);
1175 tail_lsn = xlog_assign_tail_lsn_locked(mp);
1176 spin_unlock(&mp->m_ail->ail_lock);
1177
1178 return tail_lsn;
1179}
1180
1181/*
1182 * Return the space in the log between the tail and the head. The head
1183 * is passed in the cycle/bytes formal parms. In the special case where
1184 * the reserve head has wrapped passed the tail, this calculation is no
1185 * longer valid. In this case, just return 0 which means there is no space
1186 * in the log. This works for all places where this function is called
1187 * with the reserve head. Of course, if the write head were to ever
1188 * wrap the tail, we should blow up. Rather than catch this case here,
1189 * we depend on other ASSERTions in other parts of the code. XXXmiken
1190 *
1191 * This code also handles the case where the reservation head is behind
1192 * the tail. The details of this case are described below, but the end
1193 * result is that we return the size of the log as the amount of space left.
1194 */
1195STATIC int
1196xlog_space_left(
1197 struct xlog *log,
1198 atomic64_t *head)
1199{
1200 int free_bytes;
1201 int tail_bytes;
1202 int tail_cycle;
1203 int head_cycle;
1204 int head_bytes;
1205
1206 xlog_crack_grant_head(head, &head_cycle, &head_bytes);
1207 xlog_crack_atomic_lsn(&log->l_tail_lsn, &tail_cycle, &tail_bytes);
1208 tail_bytes = BBTOB(tail_bytes);
1209 if (tail_cycle == head_cycle && head_bytes >= tail_bytes)
1210 free_bytes = log->l_logsize - (head_bytes - tail_bytes);
1211 else if (tail_cycle + 1 < head_cycle)
1212 return 0;
1213 else if (tail_cycle < head_cycle) {
1214 ASSERT(tail_cycle == (head_cycle - 1));
1215 free_bytes = tail_bytes - head_bytes;
1216 } else {
1217 /*
1218 * The reservation head is behind the tail.
1219 * In this case we just want to return the size of the
1220 * log as the amount of space left.
1221 */
1222 xfs_alert(log->l_mp, "xlog_space_left: head behind tail");
1223 xfs_alert(log->l_mp,
1224 " tail_cycle = %d, tail_bytes = %d",
1225 tail_cycle, tail_bytes);
1226 xfs_alert(log->l_mp,
1227 " GH cycle = %d, GH bytes = %d",
1228 head_cycle, head_bytes);
1229 ASSERT(0);
1230 free_bytes = log->l_logsize;
1231 }
1232 return free_bytes;
1233}
1234
1235
1236/*
1237 * Log function which is called when an io completes.
1238 *
1239 * The log manager needs its own routine, in order to control what
1240 * happens with the buffer after the write completes.
1241 */
1242static void
1243xlog_iodone(xfs_buf_t *bp)
1244{
1245 struct xlog_in_core *iclog = bp->b_log_item;
1246 struct xlog *l = iclog->ic_log;
1247 int aborted = 0;
1248
1249 /*
1250 * Race to shutdown the filesystem if we see an error or the iclog is in
1251 * IOABORT state. The IOABORT state is only set in DEBUG mode to inject
1252 * CRC errors into log recovery.
1253 */
1254 if (XFS_TEST_ERROR(bp->b_error, l->l_mp, XFS_ERRTAG_IODONE_IOERR) ||
1255 iclog->ic_state & XLOG_STATE_IOABORT) {
1256 if (iclog->ic_state & XLOG_STATE_IOABORT)
1257 iclog->ic_state &= ~XLOG_STATE_IOABORT;
1258
1259 xfs_buf_ioerror_alert(bp, __func__);
1260 xfs_buf_stale(bp);
1261 xfs_force_shutdown(l->l_mp, SHUTDOWN_LOG_IO_ERROR);
1262 /*
1263 * This flag will be propagated to the trans-committed
1264 * callback routines to let them know that the log-commit
1265 * didn't succeed.
1266 */
1267 aborted = XFS_LI_ABORTED;
1268 } else if (iclog->ic_state & XLOG_STATE_IOERROR) {
1269 aborted = XFS_LI_ABORTED;
1270 }
1271
1272 /* log I/O is always issued ASYNC */
1273 ASSERT(bp->b_flags & XBF_ASYNC);
1274 xlog_state_done_syncing(iclog, aborted);
1275
1276 /*
1277 * drop the buffer lock now that we are done. Nothing references
1278 * the buffer after this, so an unmount waiting on this lock can now
1279 * tear it down safely. As such, it is unsafe to reference the buffer
1280 * (bp) after the unlock as we could race with it being freed.
1281 */
1282 xfs_buf_unlock(bp);
1283}
1284
1285/*
1286 * Return size of each in-core log record buffer.
1287 *
1288 * All machines get 8 x 32kB buffers by default, unless tuned otherwise.
1289 *
1290 * If the filesystem blocksize is too large, we may need to choose a
1291 * larger size since the directory code currently logs entire blocks.
1292 */
1293
1294STATIC void
1295xlog_get_iclog_buffer_size(
1296 struct xfs_mount *mp,
1297 struct xlog *log)
1298{
1299 int size;
1300 int xhdrs;
1301
1302 if (mp->m_logbufs <= 0)
1303 log->l_iclog_bufs = XLOG_MAX_ICLOGS;
1304 else
1305 log->l_iclog_bufs = mp->m_logbufs;
1306
1307 /*
1308 * Buffer size passed in from mount system call.
1309 */
1310 if (mp->m_logbsize > 0) {
1311 size = log->l_iclog_size = mp->m_logbsize;
1312 log->l_iclog_size_log = 0;
1313 while (size != 1) {
1314 log->l_iclog_size_log++;
1315 size >>= 1;
1316 }
1317
1318 if (xfs_sb_version_haslogv2(&mp->m_sb)) {
1319 /* # headers = size / 32k
1320 * one header holds cycles from 32k of data
1321 */
1322
1323 xhdrs = mp->m_logbsize / XLOG_HEADER_CYCLE_SIZE;
1324 if (mp->m_logbsize % XLOG_HEADER_CYCLE_SIZE)
1325 xhdrs++;
1326 log->l_iclog_hsize = xhdrs << BBSHIFT;
1327 log->l_iclog_heads = xhdrs;
1328 } else {
1329 ASSERT(mp->m_logbsize <= XLOG_BIG_RECORD_BSIZE);
1330 log->l_iclog_hsize = BBSIZE;
1331 log->l_iclog_heads = 1;
1332 }
1333 goto done;
1334 }
1335
1336 /* All machines use 32kB buffers by default. */
1337 log->l_iclog_size = XLOG_BIG_RECORD_BSIZE;
1338 log->l_iclog_size_log = XLOG_BIG_RECORD_BSHIFT;
1339
1340 /* the default log size is 16k or 32k which is one header sector */
1341 log->l_iclog_hsize = BBSIZE;
1342 log->l_iclog_heads = 1;
1343
1344done:
1345 /* are we being asked to make the sizes selected above visible? */
1346 if (mp->m_logbufs == 0)
1347 mp->m_logbufs = log->l_iclog_bufs;
1348 if (mp->m_logbsize == 0)
1349 mp->m_logbsize = log->l_iclog_size;
1350} /* xlog_get_iclog_buffer_size */
1351
1352
1353void
1354xfs_log_work_queue(
1355 struct xfs_mount *mp)
1356{
1357 queue_delayed_work(mp->m_sync_workqueue, &mp->m_log->l_work,
1358 msecs_to_jiffies(xfs_syncd_centisecs * 10));
1359}
1360
1361/*
1362 * Every sync period we need to unpin all items in the AIL and push them to
1363 * disk. If there is nothing dirty, then we might need to cover the log to
1364 * indicate that the filesystem is idle.
1365 */
1366static void
1367xfs_log_worker(
1368 struct work_struct *work)
1369{
1370 struct xlog *log = container_of(to_delayed_work(work),
1371 struct xlog, l_work);
1372 struct xfs_mount *mp = log->l_mp;
1373
1374 /* dgc: errors ignored - not fatal and nowhere to report them */
1375 if (xfs_log_need_covered(mp)) {
1376 /*
1377 * Dump a transaction into the log that contains no real change.
1378 * This is needed to stamp the current tail LSN into the log
1379 * during the covering operation.
1380 *
1381 * We cannot use an inode here for this - that will push dirty
1382 * state back up into the VFS and then periodic inode flushing
1383 * will prevent log covering from making progress. Hence we
1384 * synchronously log the superblock instead to ensure the
1385 * superblock is immediately unpinned and can be written back.
1386 */
1387 xfs_sync_sb(mp, true);
1388 } else
1389 xfs_log_force(mp, 0);
1390
1391 /* start pushing all the metadata that is currently dirty */
1392 xfs_ail_push_all(mp->m_ail);
1393
1394 /* queue us up again */
1395 xfs_log_work_queue(mp);
1396}
1397
1398/*
1399 * This routine initializes some of the log structure for a given mount point.
1400 * Its primary purpose is to fill in enough, so recovery can occur. However,
1401 * some other stuff may be filled in too.
1402 */
1403STATIC struct xlog *
1404xlog_alloc_log(
1405 struct xfs_mount *mp,
1406 struct xfs_buftarg *log_target,
1407 xfs_daddr_t blk_offset,
1408 int num_bblks)
1409{
1410 struct xlog *log;
1411 xlog_rec_header_t *head;
1412 xlog_in_core_t **iclogp;
1413 xlog_in_core_t *iclog, *prev_iclog=NULL;
1414 xfs_buf_t *bp;
1415 int i;
1416 int error = -ENOMEM;
1417 uint log2_size = 0;
1418
1419 log = kmem_zalloc(sizeof(struct xlog), KM_MAYFAIL);
1420 if (!log) {
1421 xfs_warn(mp, "Log allocation failed: No memory!");
1422 goto out;
1423 }
1424
1425 log->l_mp = mp;
1426 log->l_targ = log_target;
1427 log->l_logsize = BBTOB(num_bblks);
1428 log->l_logBBstart = blk_offset;
1429 log->l_logBBsize = num_bblks;
1430 log->l_covered_state = XLOG_STATE_COVER_IDLE;
1431 log->l_flags |= XLOG_ACTIVE_RECOVERY;
1432 INIT_DELAYED_WORK(&log->l_work, xfs_log_worker);
1433
1434 log->l_prev_block = -1;
1435 /* log->l_tail_lsn = 0x100000000LL; cycle = 1; current block = 0 */
1436 xlog_assign_atomic_lsn(&log->l_tail_lsn, 1, 0);
1437 xlog_assign_atomic_lsn(&log->l_last_sync_lsn, 1, 0);
1438 log->l_curr_cycle = 1; /* 0 is bad since this is initial value */
1439
1440 xlog_grant_head_init(&log->l_reserve_head);
1441 xlog_grant_head_init(&log->l_write_head);
1442
1443 error = -EFSCORRUPTED;
1444 if (xfs_sb_version_hassector(&mp->m_sb)) {
1445 log2_size = mp->m_sb.sb_logsectlog;
1446 if (log2_size < BBSHIFT) {
1447 xfs_warn(mp, "Log sector size too small (0x%x < 0x%x)",
1448 log2_size, BBSHIFT);
1449 goto out_free_log;
1450 }
1451
1452 log2_size -= BBSHIFT;
1453 if (log2_size > mp->m_sectbb_log) {
1454 xfs_warn(mp, "Log sector size too large (0x%x > 0x%x)",
1455 log2_size, mp->m_sectbb_log);
1456 goto out_free_log;
1457 }
1458
1459 /* for larger sector sizes, must have v2 or external log */
1460 if (log2_size && log->l_logBBstart > 0 &&
1461 !xfs_sb_version_haslogv2(&mp->m_sb)) {
1462 xfs_warn(mp,
1463 "log sector size (0x%x) invalid for configuration.",
1464 log2_size);
1465 goto out_free_log;
1466 }
1467 }
1468 log->l_sectBBsize = 1 << log2_size;
1469
1470 xlog_get_iclog_buffer_size(mp, log);
1471
1472 /*
1473 * Use a NULL block for the extra log buffer used during splits so that
1474 * it will trigger errors if we ever try to do IO on it without first
1475 * having set it up properly.
1476 */
1477 error = -ENOMEM;
1478 bp = xfs_buf_alloc(mp->m_logdev_targp, XFS_BUF_DADDR_NULL,
1479 BTOBB(log->l_iclog_size), XBF_NO_IOACCT);
1480 if (!bp)
1481 goto out_free_log;
1482
1483 /*
1484 * The iclogbuf buffer locks are held over IO but we are not going to do
1485 * IO yet. Hence unlock the buffer so that the log IO path can grab it
1486 * when appropriately.
1487 */
1488 ASSERT(xfs_buf_islocked(bp));
1489 xfs_buf_unlock(bp);
1490
1491 /* use high priority wq for log I/O completion */
1492 bp->b_ioend_wq = mp->m_log_workqueue;
1493 bp->b_iodone = xlog_iodone;
1494 log->l_xbuf = bp;
1495
1496 spin_lock_init(&log->l_icloglock);
1497 init_waitqueue_head(&log->l_flush_wait);
1498
1499 iclogp = &log->l_iclog;
1500 /*
1501 * The amount of memory to allocate for the iclog structure is
1502 * rather funky due to the way the structure is defined. It is
1503 * done this way so that we can use different sizes for machines
1504 * with different amounts of memory. See the definition of
1505 * xlog_in_core_t in xfs_log_priv.h for details.
1506 */
1507 ASSERT(log->l_iclog_size >= 4096);
1508 for (i=0; i < log->l_iclog_bufs; i++) {
1509 *iclogp = kmem_zalloc(sizeof(xlog_in_core_t), KM_MAYFAIL);
1510 if (!*iclogp)
1511 goto out_free_iclog;
1512
1513 iclog = *iclogp;
1514 iclog->ic_prev = prev_iclog;
1515 prev_iclog = iclog;
1516
1517 bp = xfs_buf_get_uncached(mp->m_logdev_targp,
1518 BTOBB(log->l_iclog_size),
1519 XBF_NO_IOACCT);
1520 if (!bp)
1521 goto out_free_iclog;
1522
1523 ASSERT(xfs_buf_islocked(bp));
1524 xfs_buf_unlock(bp);
1525
1526 /* use high priority wq for log I/O completion */
1527 bp->b_ioend_wq = mp->m_log_workqueue;
1528 bp->b_iodone = xlog_iodone;
1529 iclog->ic_bp = bp;
1530 iclog->ic_data = bp->b_addr;
1531#ifdef DEBUG
1532 log->l_iclog_bak[i] = &iclog->ic_header;
1533#endif
1534 head = &iclog->ic_header;
1535 memset(head, 0, sizeof(xlog_rec_header_t));
1536 head->h_magicno = cpu_to_be32(XLOG_HEADER_MAGIC_NUM);
1537 head->h_version = cpu_to_be32(
1538 xfs_sb_version_haslogv2(&log->l_mp->m_sb) ? 2 : 1);
1539 head->h_size = cpu_to_be32(log->l_iclog_size);
1540 /* new fields */
1541 head->h_fmt = cpu_to_be32(XLOG_FMT);
1542 memcpy(&head->h_fs_uuid, &mp->m_sb.sb_uuid, sizeof(uuid_t));
1543
1544 iclog->ic_size = BBTOB(bp->b_length) - log->l_iclog_hsize;
1545 iclog->ic_state = XLOG_STATE_ACTIVE;
1546 iclog->ic_log = log;
1547 atomic_set(&iclog->ic_refcnt, 0);
1548 spin_lock_init(&iclog->ic_callback_lock);
1549 iclog->ic_callback_tail = &(iclog->ic_callback);
1550 iclog->ic_datap = (char *)iclog->ic_data + log->l_iclog_hsize;
1551
1552 init_waitqueue_head(&iclog->ic_force_wait);
1553 init_waitqueue_head(&iclog->ic_write_wait);
1554
1555 iclogp = &iclog->ic_next;
1556 }
1557 *iclogp = log->l_iclog; /* complete ring */
1558 log->l_iclog->ic_prev = prev_iclog; /* re-write 1st prev ptr */
1559
1560 error = xlog_cil_init(log);
1561 if (error)
1562 goto out_free_iclog;
1563 return log;
1564
1565out_free_iclog:
1566 for (iclog = log->l_iclog; iclog; iclog = prev_iclog) {
1567 prev_iclog = iclog->ic_next;
1568 if (iclog->ic_bp)
1569 xfs_buf_free(iclog->ic_bp);
1570 kmem_free(iclog);
1571 }
1572 spinlock_destroy(&log->l_icloglock);
1573 xfs_buf_free(log->l_xbuf);
1574out_free_log:
1575 kmem_free(log);
1576out:
1577 return ERR_PTR(error);
1578} /* xlog_alloc_log */
1579
1580
1581/*
1582 * Write out the commit record of a transaction associated with the given
1583 * ticket. Return the lsn of the commit record.
1584 */
1585STATIC int
1586xlog_commit_record(
1587 struct xlog *log,
1588 struct xlog_ticket *ticket,
1589 struct xlog_in_core **iclog,
1590 xfs_lsn_t *commitlsnp)
1591{
1592 struct xfs_mount *mp = log->l_mp;
1593 int error;
1594 struct xfs_log_iovec reg = {
1595 .i_addr = NULL,
1596 .i_len = 0,
1597 .i_type = XLOG_REG_TYPE_COMMIT,
1598 };
1599 struct xfs_log_vec vec = {
1600 .lv_niovecs = 1,
1601 .lv_iovecp = ®,
1602 };
1603
1604 ASSERT_ALWAYS(iclog);
1605 error = xlog_write(log, &vec, ticket, commitlsnp, iclog,
1606 XLOG_COMMIT_TRANS);
1607 if (error)
1608 xfs_force_shutdown(mp, SHUTDOWN_LOG_IO_ERROR);
1609 return error;
1610}
1611
1612/*
1613 * Push on the buffer cache code if we ever use more than 75% of the on-disk
1614 * log space. This code pushes on the lsn which would supposedly free up
1615 * the 25% which we want to leave free. We may need to adopt a policy which
1616 * pushes on an lsn which is further along in the log once we reach the high
1617 * water mark. In this manner, we would be creating a low water mark.
1618 */
1619STATIC void
1620xlog_grant_push_ail(
1621 struct xlog *log,
1622 int need_bytes)
1623{
1624 xfs_lsn_t threshold_lsn = 0;
1625 xfs_lsn_t last_sync_lsn;
1626 int free_blocks;
1627 int free_bytes;
1628 int threshold_block;
1629 int threshold_cycle;
1630 int free_threshold;
1631
1632 ASSERT(BTOBB(need_bytes) < log->l_logBBsize);
1633
1634 free_bytes = xlog_space_left(log, &log->l_reserve_head.grant);
1635 free_blocks = BTOBBT(free_bytes);
1636
1637 /*
1638 * Set the threshold for the minimum number of free blocks in the
1639 * log to the maximum of what the caller needs, one quarter of the
1640 * log, and 256 blocks.
1641 */
1642 free_threshold = BTOBB(need_bytes);
1643 free_threshold = MAX(free_threshold, (log->l_logBBsize >> 2));
1644 free_threshold = MAX(free_threshold, 256);
1645 if (free_blocks >= free_threshold)
1646 return;
1647
1648 xlog_crack_atomic_lsn(&log->l_tail_lsn, &threshold_cycle,
1649 &threshold_block);
1650 threshold_block += free_threshold;
1651 if (threshold_block >= log->l_logBBsize) {
1652 threshold_block -= log->l_logBBsize;
1653 threshold_cycle += 1;
1654 }
1655 threshold_lsn = xlog_assign_lsn(threshold_cycle,
1656 threshold_block);
1657 /*
1658 * Don't pass in an lsn greater than the lsn of the last
1659 * log record known to be on disk. Use a snapshot of the last sync lsn
1660 * so that it doesn't change between the compare and the set.
1661 */
1662 last_sync_lsn = atomic64_read(&log->l_last_sync_lsn);
1663 if (XFS_LSN_CMP(threshold_lsn, last_sync_lsn) > 0)
1664 threshold_lsn = last_sync_lsn;
1665
1666 /*
1667 * Get the transaction layer to kick the dirty buffers out to
1668 * disk asynchronously. No point in trying to do this if
1669 * the filesystem is shutting down.
1670 */
1671 if (!XLOG_FORCED_SHUTDOWN(log))
1672 xfs_ail_push(log->l_ailp, threshold_lsn);
1673}
1674
1675/*
1676 * Stamp cycle number in every block
1677 */
1678STATIC void
1679xlog_pack_data(
1680 struct xlog *log,
1681 struct xlog_in_core *iclog,
1682 int roundoff)
1683{
1684 int i, j, k;
1685 int size = iclog->ic_offset + roundoff;
1686 __be32 cycle_lsn;
1687 char *dp;
1688
1689 cycle_lsn = CYCLE_LSN_DISK(iclog->ic_header.h_lsn);
1690
1691 dp = iclog->ic_datap;
1692 for (i = 0; i < BTOBB(size); i++) {
1693 if (i >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE))
1694 break;
1695 iclog->ic_header.h_cycle_data[i] = *(__be32 *)dp;
1696 *(__be32 *)dp = cycle_lsn;
1697 dp += BBSIZE;
1698 }
1699
1700 if (xfs_sb_version_haslogv2(&log->l_mp->m_sb)) {
1701 xlog_in_core_2_t *xhdr = iclog->ic_data;
1702
1703 for ( ; i < BTOBB(size); i++) {
1704 j = i / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
1705 k = i % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
1706 xhdr[j].hic_xheader.xh_cycle_data[k] = *(__be32 *)dp;
1707 *(__be32 *)dp = cycle_lsn;
1708 dp += BBSIZE;
1709 }
1710
1711 for (i = 1; i < log->l_iclog_heads; i++)
1712 xhdr[i].hic_xheader.xh_cycle = cycle_lsn;
1713 }
1714}
1715
1716/*
1717 * Calculate the checksum for a log buffer.
1718 *
1719 * This is a little more complicated than it should be because the various
1720 * headers and the actual data are non-contiguous.
1721 */
1722__le32
1723xlog_cksum(
1724 struct xlog *log,
1725 struct xlog_rec_header *rhead,
1726 char *dp,
1727 int size)
1728{
1729 uint32_t crc;
1730
1731 /* first generate the crc for the record header ... */
1732 crc = xfs_start_cksum_update((char *)rhead,
1733 sizeof(struct xlog_rec_header),
1734 offsetof(struct xlog_rec_header, h_crc));
1735
1736 /* ... then for additional cycle data for v2 logs ... */
1737 if (xfs_sb_version_haslogv2(&log->l_mp->m_sb)) {
1738 union xlog_in_core2 *xhdr = (union xlog_in_core2 *)rhead;
1739 int i;
1740 int xheads;
1741
1742 xheads = size / XLOG_HEADER_CYCLE_SIZE;
1743 if (size % XLOG_HEADER_CYCLE_SIZE)
1744 xheads++;
1745
1746 for (i = 1; i < xheads; i++) {
1747 crc = crc32c(crc, &xhdr[i].hic_xheader,
1748 sizeof(struct xlog_rec_ext_header));
1749 }
1750 }
1751
1752 /* ... and finally for the payload */
1753 crc = crc32c(crc, dp, size);
1754
1755 return xfs_end_cksum(crc);
1756}
1757
1758/*
1759 * The bdstrat callback function for log bufs. This gives us a central
1760 * place to trap bufs in case we get hit by a log I/O error and need to
1761 * shutdown. Actually, in practice, even when we didn't get a log error,
1762 * we transition the iclogs to IOERROR state *after* flushing all existing
1763 * iclogs to disk. This is because we don't want anymore new transactions to be
1764 * started or completed afterwards.
1765 *
1766 * We lock the iclogbufs here so that we can serialise against IO completion
1767 * during unmount. We might be processing a shutdown triggered during unmount,
1768 * and that can occur asynchronously to the unmount thread, and hence we need to
1769 * ensure that completes before tearing down the iclogbufs. Hence we need to
1770 * hold the buffer lock across the log IO to acheive that.
1771 */
1772STATIC int
1773xlog_bdstrat(
1774 struct xfs_buf *bp)
1775{
1776 struct xlog_in_core *iclog = bp->b_log_item;
1777
1778 xfs_buf_lock(bp);
1779 if (iclog->ic_state & XLOG_STATE_IOERROR) {
1780 xfs_buf_ioerror(bp, -EIO);
1781 xfs_buf_stale(bp);
1782 xfs_buf_ioend(bp);
1783 /*
1784 * It would seem logical to return EIO here, but we rely on
1785 * the log state machine to propagate I/O errors instead of
1786 * doing it here. Similarly, IO completion will unlock the
1787 * buffer, so we don't do it here.
1788 */
1789 return 0;
1790 }
1791
1792 xfs_buf_submit(bp);
1793 return 0;
1794}
1795
1796/*
1797 * Flush out the in-core log (iclog) to the on-disk log in an asynchronous
1798 * fashion. Previously, we should have moved the current iclog
1799 * ptr in the log to point to the next available iclog. This allows further
1800 * write to continue while this code syncs out an iclog ready to go.
1801 * Before an in-core log can be written out, the data section must be scanned
1802 * to save away the 1st word of each BBSIZE block into the header. We replace
1803 * it with the current cycle count. Each BBSIZE block is tagged with the
1804 * cycle count because there in an implicit assumption that drives will
1805 * guarantee that entire 512 byte blocks get written at once. In other words,
1806 * we can't have part of a 512 byte block written and part not written. By
1807 * tagging each block, we will know which blocks are valid when recovering
1808 * after an unclean shutdown.
1809 *
1810 * This routine is single threaded on the iclog. No other thread can be in
1811 * this routine with the same iclog. Changing contents of iclog can there-
1812 * fore be done without grabbing the state machine lock. Updating the global
1813 * log will require grabbing the lock though.
1814 *
1815 * The entire log manager uses a logical block numbering scheme. Only
1816 * log_sync (and then only bwrite()) know about the fact that the log may
1817 * not start with block zero on a given device. The log block start offset
1818 * is added immediately before calling bwrite().
1819 */
1820
1821STATIC int
1822xlog_sync(
1823 struct xlog *log,
1824 struct xlog_in_core *iclog)
1825{
1826 xfs_buf_t *bp;
1827 int i;
1828 uint count; /* byte count of bwrite */
1829 uint count_init; /* initial count before roundup */
1830 int roundoff; /* roundoff to BB or stripe */
1831 int split = 0; /* split write into two regions */
1832 int error;
1833 int v2 = xfs_sb_version_haslogv2(&log->l_mp->m_sb);
1834 int size;
1835
1836 XFS_STATS_INC(log->l_mp, xs_log_writes);
1837 ASSERT(atomic_read(&iclog->ic_refcnt) == 0);
1838
1839 /* Add for LR header */
1840 count_init = log->l_iclog_hsize + iclog->ic_offset;
1841
1842 /* Round out the log write size */
1843 if (v2 && log->l_mp->m_sb.sb_logsunit > 1) {
1844 /* we have a v2 stripe unit to use */
1845 count = XLOG_LSUNITTOB(log, XLOG_BTOLSUNIT(log, count_init));
1846 } else {
1847 count = BBTOB(BTOBB(count_init));
1848 }
1849 roundoff = count - count_init;
1850 ASSERT(roundoff >= 0);
1851 ASSERT((v2 && log->l_mp->m_sb.sb_logsunit > 1 &&
1852 roundoff < log->l_mp->m_sb.sb_logsunit)
1853 ||
1854 (log->l_mp->m_sb.sb_logsunit <= 1 &&
1855 roundoff < BBTOB(1)));
1856
1857 /* move grant heads by roundoff in sync */
1858 xlog_grant_add_space(log, &log->l_reserve_head.grant, roundoff);
1859 xlog_grant_add_space(log, &log->l_write_head.grant, roundoff);
1860
1861 /* put cycle number in every block */
1862 xlog_pack_data(log, iclog, roundoff);
1863
1864 /* real byte length */
1865 size = iclog->ic_offset;
1866 if (v2)
1867 size += roundoff;
1868 iclog->ic_header.h_len = cpu_to_be32(size);
1869
1870 bp = iclog->ic_bp;
1871 XFS_BUF_SET_ADDR(bp, BLOCK_LSN(be64_to_cpu(iclog->ic_header.h_lsn)));
1872
1873 XFS_STATS_ADD(log->l_mp, xs_log_blocks, BTOBB(count));
1874
1875 /* Do we need to split this write into 2 parts? */
1876 if (XFS_BUF_ADDR(bp) + BTOBB(count) > log->l_logBBsize) {
1877 char *dptr;
1878
1879 split = count - (BBTOB(log->l_logBBsize - XFS_BUF_ADDR(bp)));
1880 count = BBTOB(log->l_logBBsize - XFS_BUF_ADDR(bp));
1881 iclog->ic_bwritecnt = 2;
1882
1883 /*
1884 * Bump the cycle numbers at the start of each block in the
1885 * part of the iclog that ends up in the buffer that gets
1886 * written to the start of the log.
1887 *
1888 * Watch out for the header magic number case, though.
1889 */
1890 dptr = (char *)&iclog->ic_header + count;
1891 for (i = 0; i < split; i += BBSIZE) {
1892 uint32_t cycle = be32_to_cpu(*(__be32 *)dptr);
1893 if (++cycle == XLOG_HEADER_MAGIC_NUM)
1894 cycle++;
1895 *(__be32 *)dptr = cpu_to_be32(cycle);
1896
1897 dptr += BBSIZE;
1898 }
1899 } else {
1900 iclog->ic_bwritecnt = 1;
1901 }
1902
1903 /* calculcate the checksum */
1904 iclog->ic_header.h_crc = xlog_cksum(log, &iclog->ic_header,
1905 iclog->ic_datap, size);
1906 /*
1907 * Intentionally corrupt the log record CRC based on the error injection
1908 * frequency, if defined. This facilitates testing log recovery in the
1909 * event of torn writes. Hence, set the IOABORT state to abort the log
1910 * write on I/O completion and shutdown the fs. The subsequent mount
1911 * detects the bad CRC and attempts to recover.
1912 */
1913 if (XFS_TEST_ERROR(false, log->l_mp, XFS_ERRTAG_LOG_BAD_CRC)) {
1914 iclog->ic_header.h_crc &= cpu_to_le32(0xAAAAAAAA);
1915 iclog->ic_state |= XLOG_STATE_IOABORT;
1916 xfs_warn(log->l_mp,
1917 "Intentionally corrupted log record at LSN 0x%llx. Shutdown imminent.",
1918 be64_to_cpu(iclog->ic_header.h_lsn));
1919 }
1920
1921 bp->b_io_length = BTOBB(count);
1922 bp->b_log_item = iclog;
1923 bp->b_flags &= ~XBF_FLUSH;
1924 bp->b_flags |= (XBF_ASYNC | XBF_SYNCIO | XBF_WRITE | XBF_FUA);
1925
1926 /*
1927 * Flush the data device before flushing the log to make sure all meta
1928 * data written back from the AIL actually made it to disk before
1929 * stamping the new log tail LSN into the log buffer. For an external
1930 * log we need to issue the flush explicitly, and unfortunately
1931 * synchronously here; for an internal log we can simply use the block
1932 * layer state machine for preflushes.
1933 */
1934 if (log->l_mp->m_logdev_targp != log->l_mp->m_ddev_targp)
1935 xfs_blkdev_issue_flush(log->l_mp->m_ddev_targp);
1936 else
1937 bp->b_flags |= XBF_FLUSH;
1938
1939 ASSERT(XFS_BUF_ADDR(bp) <= log->l_logBBsize-1);
1940 ASSERT(XFS_BUF_ADDR(bp) + BTOBB(count) <= log->l_logBBsize);
1941
1942 xlog_verify_iclog(log, iclog, count, true);
1943
1944 /* account for log which doesn't start at block #0 */
1945 XFS_BUF_SET_ADDR(bp, XFS_BUF_ADDR(bp) + log->l_logBBstart);
1946
1947 /*
1948 * Don't call xfs_bwrite here. We do log-syncs even when the filesystem
1949 * is shutting down.
1950 */
1951 error = xlog_bdstrat(bp);
1952 if (error) {
1953 xfs_buf_ioerror_alert(bp, "xlog_sync");
1954 return error;
1955 }
1956 if (split) {
1957 bp = iclog->ic_log->l_xbuf;
1958 XFS_BUF_SET_ADDR(bp, 0); /* logical 0 */
1959 xfs_buf_associate_memory(bp,
1960 (char *)&iclog->ic_header + count, split);
1961 bp->b_log_item = iclog;
1962 bp->b_flags &= ~XBF_FLUSH;
1963 bp->b_flags |= (XBF_ASYNC | XBF_SYNCIO | XBF_WRITE | XBF_FUA);
1964
1965 ASSERT(XFS_BUF_ADDR(bp) <= log->l_logBBsize-1);
1966 ASSERT(XFS_BUF_ADDR(bp) + BTOBB(count) <= log->l_logBBsize);
1967
1968 /* account for internal log which doesn't start at block #0 */
1969 XFS_BUF_SET_ADDR(bp, XFS_BUF_ADDR(bp) + log->l_logBBstart);
1970 error = xlog_bdstrat(bp);
1971 if (error) {
1972 xfs_buf_ioerror_alert(bp, "xlog_sync (split)");
1973 return error;
1974 }
1975 }
1976 return 0;
1977} /* xlog_sync */
1978
1979/*
1980 * Deallocate a log structure
1981 */
1982STATIC void
1983xlog_dealloc_log(
1984 struct xlog *log)
1985{
1986 xlog_in_core_t *iclog, *next_iclog;
1987 int i;
1988
1989 xlog_cil_destroy(log);
1990
1991 /*
1992 * Cycle all the iclogbuf locks to make sure all log IO completion
1993 * is done before we tear down these buffers.
1994 */
1995 iclog = log->l_iclog;
1996 for (i = 0; i < log->l_iclog_bufs; i++) {
1997 xfs_buf_lock(iclog->ic_bp);
1998 xfs_buf_unlock(iclog->ic_bp);
1999 iclog = iclog->ic_next;
2000 }
2001
2002 /*
2003 * Always need to ensure that the extra buffer does not point to memory
2004 * owned by another log buffer before we free it. Also, cycle the lock
2005 * first to ensure we've completed IO on it.
2006 */
2007 xfs_buf_lock(log->l_xbuf);
2008 xfs_buf_unlock(log->l_xbuf);
2009 xfs_buf_set_empty(log->l_xbuf, BTOBB(log->l_iclog_size));
2010 xfs_buf_free(log->l_xbuf);
2011
2012 iclog = log->l_iclog;
2013 for (i = 0; i < log->l_iclog_bufs; i++) {
2014 xfs_buf_free(iclog->ic_bp);
2015 next_iclog = iclog->ic_next;
2016 kmem_free(iclog);
2017 iclog = next_iclog;
2018 }
2019 spinlock_destroy(&log->l_icloglock);
2020
2021 log->l_mp->m_log = NULL;
2022 kmem_free(log);
2023} /* xlog_dealloc_log */
2024
2025/*
2026 * Update counters atomically now that memcpy is done.
2027 */
2028/* ARGSUSED */
2029static inline void
2030xlog_state_finish_copy(
2031 struct xlog *log,
2032 struct xlog_in_core *iclog,
2033 int record_cnt,
2034 int copy_bytes)
2035{
2036 spin_lock(&log->l_icloglock);
2037
2038 be32_add_cpu(&iclog->ic_header.h_num_logops, record_cnt);
2039 iclog->ic_offset += copy_bytes;
2040
2041 spin_unlock(&log->l_icloglock);
2042} /* xlog_state_finish_copy */
2043
2044
2045
2046
2047/*
2048 * print out info relating to regions written which consume
2049 * the reservation
2050 */
2051void
2052xlog_print_tic_res(
2053 struct xfs_mount *mp,
2054 struct xlog_ticket *ticket)
2055{
2056 uint i;
2057 uint ophdr_spc = ticket->t_res_num_ophdrs * (uint)sizeof(xlog_op_header_t);
2058
2059 /* match with XLOG_REG_TYPE_* in xfs_log.h */
2060#define REG_TYPE_STR(type, str) [XLOG_REG_TYPE_##type] = str
2061 static char *res_type_str[XLOG_REG_TYPE_MAX + 1] = {
2062 REG_TYPE_STR(BFORMAT, "bformat"),
2063 REG_TYPE_STR(BCHUNK, "bchunk"),
2064 REG_TYPE_STR(EFI_FORMAT, "efi_format"),
2065 REG_TYPE_STR(EFD_FORMAT, "efd_format"),
2066 REG_TYPE_STR(IFORMAT, "iformat"),
2067 REG_TYPE_STR(ICORE, "icore"),
2068 REG_TYPE_STR(IEXT, "iext"),
2069 REG_TYPE_STR(IBROOT, "ibroot"),
2070 REG_TYPE_STR(ILOCAL, "ilocal"),
2071 REG_TYPE_STR(IATTR_EXT, "iattr_ext"),
2072 REG_TYPE_STR(IATTR_BROOT, "iattr_broot"),
2073 REG_TYPE_STR(IATTR_LOCAL, "iattr_local"),
2074 REG_TYPE_STR(QFORMAT, "qformat"),
2075 REG_TYPE_STR(DQUOT, "dquot"),
2076 REG_TYPE_STR(QUOTAOFF, "quotaoff"),
2077 REG_TYPE_STR(LRHEADER, "LR header"),
2078 REG_TYPE_STR(UNMOUNT, "unmount"),
2079 REG_TYPE_STR(COMMIT, "commit"),
2080 REG_TYPE_STR(TRANSHDR, "trans header"),
2081 REG_TYPE_STR(ICREATE, "inode create")
2082 };
2083#undef REG_TYPE_STR
2084
2085 xfs_warn(mp, "ticket reservation summary:");
2086 xfs_warn(mp, " unit res = %d bytes",
2087 ticket->t_unit_res);
2088 xfs_warn(mp, " current res = %d bytes",
2089 ticket->t_curr_res);
2090 xfs_warn(mp, " total reg = %u bytes (o/flow = %u bytes)",
2091 ticket->t_res_arr_sum, ticket->t_res_o_flow);
2092 xfs_warn(mp, " ophdrs = %u (ophdr space = %u bytes)",
2093 ticket->t_res_num_ophdrs, ophdr_spc);
2094 xfs_warn(mp, " ophdr + reg = %u bytes",
2095 ticket->t_res_arr_sum + ticket->t_res_o_flow + ophdr_spc);
2096 xfs_warn(mp, " num regions = %u",
2097 ticket->t_res_num);
2098
2099 for (i = 0; i < ticket->t_res_num; i++) {
2100 uint r_type = ticket->t_res_arr[i].r_type;
2101 xfs_warn(mp, "region[%u]: %s - %u bytes", i,
2102 ((r_type <= 0 || r_type > XLOG_REG_TYPE_MAX) ?
2103 "bad-rtype" : res_type_str[r_type]),
2104 ticket->t_res_arr[i].r_len);
2105 }
2106}
2107
2108/*
2109 * Print a summary of the transaction.
2110 */
2111void
2112xlog_print_trans(
2113 struct xfs_trans *tp)
2114{
2115 struct xfs_mount *mp = tp->t_mountp;
2116 struct xfs_log_item_desc *lidp;
2117
2118 /* dump core transaction and ticket info */
2119 xfs_warn(mp, "transaction summary:");
2120 xfs_warn(mp, " log res = %d", tp->t_log_res);
2121 xfs_warn(mp, " log count = %d", tp->t_log_count);
2122 xfs_warn(mp, " flags = 0x%x", tp->t_flags);
2123
2124 xlog_print_tic_res(mp, tp->t_ticket);
2125
2126 /* dump each log item */
2127 list_for_each_entry(lidp, &tp->t_items, lid_trans) {
2128 struct xfs_log_item *lip = lidp->lid_item;
2129 struct xfs_log_vec *lv = lip->li_lv;
2130 struct xfs_log_iovec *vec;
2131 int i;
2132
2133 xfs_warn(mp, "log item: ");
2134 xfs_warn(mp, " type = 0x%x", lip->li_type);
2135 xfs_warn(mp, " flags = 0x%x", lip->li_flags);
2136 if (!lv)
2137 continue;
2138 xfs_warn(mp, " niovecs = %d", lv->lv_niovecs);
2139 xfs_warn(mp, " size = %d", lv->lv_size);
2140 xfs_warn(mp, " bytes = %d", lv->lv_bytes);
2141 xfs_warn(mp, " buf len = %d", lv->lv_buf_len);
2142
2143 /* dump each iovec for the log item */
2144 vec = lv->lv_iovecp;
2145 for (i = 0; i < lv->lv_niovecs; i++) {
2146 int dumplen = min(vec->i_len, 32);
2147
2148 xfs_warn(mp, " iovec[%d]", i);
2149 xfs_warn(mp, " type = 0x%x", vec->i_type);
2150 xfs_warn(mp, " len = %d", vec->i_len);
2151 xfs_warn(mp, " first %d bytes of iovec[%d]:", dumplen, i);
2152 xfs_hex_dump(vec->i_addr, dumplen);
2153
2154 vec++;
2155 }
2156 }
2157}
2158
2159/*
2160 * Calculate the potential space needed by the log vector. Each region gets
2161 * its own xlog_op_header_t and may need to be double word aligned.
2162 */
2163static int
2164xlog_write_calc_vec_length(
2165 struct xlog_ticket *ticket,
2166 struct xfs_log_vec *log_vector)
2167{
2168 struct xfs_log_vec *lv;
2169 int headers = 0;
2170 int len = 0;
2171 int i;
2172
2173 /* acct for start rec of xact */
2174 if (ticket->t_flags & XLOG_TIC_INITED)
2175 headers++;
2176
2177 for (lv = log_vector; lv; lv = lv->lv_next) {
2178 /* we don't write ordered log vectors */
2179 if (lv->lv_buf_len == XFS_LOG_VEC_ORDERED)
2180 continue;
2181
2182 headers += lv->lv_niovecs;
2183
2184 for (i = 0; i < lv->lv_niovecs; i++) {
2185 struct xfs_log_iovec *vecp = &lv->lv_iovecp[i];
2186
2187 len += vecp->i_len;
2188 xlog_tic_add_region(ticket, vecp->i_len, vecp->i_type);
2189 }
2190 }
2191
2192 ticket->t_res_num_ophdrs += headers;
2193 len += headers * sizeof(struct xlog_op_header);
2194
2195 return len;
2196}
2197
2198/*
2199 * If first write for transaction, insert start record We can't be trying to
2200 * commit if we are inited. We can't have any "partial_copy" if we are inited.
2201 */
2202static int
2203xlog_write_start_rec(
2204 struct xlog_op_header *ophdr,
2205 struct xlog_ticket *ticket)
2206{
2207 if (!(ticket->t_flags & XLOG_TIC_INITED))
2208 return 0;
2209
2210 ophdr->oh_tid = cpu_to_be32(ticket->t_tid);
2211 ophdr->oh_clientid = ticket->t_clientid;
2212 ophdr->oh_len = 0;
2213 ophdr->oh_flags = XLOG_START_TRANS;
2214 ophdr->oh_res2 = 0;
2215
2216 ticket->t_flags &= ~XLOG_TIC_INITED;
2217
2218 return sizeof(struct xlog_op_header);
2219}
2220
2221static xlog_op_header_t *
2222xlog_write_setup_ophdr(
2223 struct xlog *log,
2224 struct xlog_op_header *ophdr,
2225 struct xlog_ticket *ticket,
2226 uint flags)
2227{
2228 ophdr->oh_tid = cpu_to_be32(ticket->t_tid);
2229 ophdr->oh_clientid = ticket->t_clientid;
2230 ophdr->oh_res2 = 0;
2231
2232 /* are we copying a commit or unmount record? */
2233 ophdr->oh_flags = flags;
2234
2235 /*
2236 * We've seen logs corrupted with bad transaction client ids. This
2237 * makes sure that XFS doesn't generate them on. Turn this into an EIO
2238 * and shut down the filesystem.
2239 */
2240 switch (ophdr->oh_clientid) {
2241 case XFS_TRANSACTION:
2242 case XFS_VOLUME:
2243 case XFS_LOG:
2244 break;
2245 default:
2246 xfs_warn(log->l_mp,
2247 "Bad XFS transaction clientid 0x%x in ticket "PTR_FMT,
2248 ophdr->oh_clientid, ticket);
2249 return NULL;
2250 }
2251
2252 return ophdr;
2253}
2254
2255/*
2256 * Set up the parameters of the region copy into the log. This has
2257 * to handle region write split across multiple log buffers - this
2258 * state is kept external to this function so that this code can
2259 * be written in an obvious, self documenting manner.
2260 */
2261static int
2262xlog_write_setup_copy(
2263 struct xlog_ticket *ticket,
2264 struct xlog_op_header *ophdr,
2265 int space_available,
2266 int space_required,
2267 int *copy_off,
2268 int *copy_len,
2269 int *last_was_partial_copy,
2270 int *bytes_consumed)
2271{
2272 int still_to_copy;
2273
2274 still_to_copy = space_required - *bytes_consumed;
2275 *copy_off = *bytes_consumed;
2276
2277 if (still_to_copy <= space_available) {
2278 /* write of region completes here */
2279 *copy_len = still_to_copy;
2280 ophdr->oh_len = cpu_to_be32(*copy_len);
2281 if (*last_was_partial_copy)
2282 ophdr->oh_flags |= (XLOG_END_TRANS|XLOG_WAS_CONT_TRANS);
2283 *last_was_partial_copy = 0;
2284 *bytes_consumed = 0;
2285 return 0;
2286 }
2287
2288 /* partial write of region, needs extra log op header reservation */
2289 *copy_len = space_available;
2290 ophdr->oh_len = cpu_to_be32(*copy_len);
2291 ophdr->oh_flags |= XLOG_CONTINUE_TRANS;
2292 if (*last_was_partial_copy)
2293 ophdr->oh_flags |= XLOG_WAS_CONT_TRANS;
2294 *bytes_consumed += *copy_len;
2295 (*last_was_partial_copy)++;
2296
2297 /* account for new log op header */
2298 ticket->t_curr_res -= sizeof(struct xlog_op_header);
2299 ticket->t_res_num_ophdrs++;
2300
2301 return sizeof(struct xlog_op_header);
2302}
2303
2304static int
2305xlog_write_copy_finish(
2306 struct xlog *log,
2307 struct xlog_in_core *iclog,
2308 uint flags,
2309 int *record_cnt,
2310 int *data_cnt,
2311 int *partial_copy,
2312 int *partial_copy_len,
2313 int log_offset,
2314 struct xlog_in_core **commit_iclog)
2315{
2316 if (*partial_copy) {
2317 /*
2318 * This iclog has already been marked WANT_SYNC by
2319 * xlog_state_get_iclog_space.
2320 */
2321 xlog_state_finish_copy(log, iclog, *record_cnt, *data_cnt);
2322 *record_cnt = 0;
2323 *data_cnt = 0;
2324 return xlog_state_release_iclog(log, iclog);
2325 }
2326
2327 *partial_copy = 0;
2328 *partial_copy_len = 0;
2329
2330 if (iclog->ic_size - log_offset <= sizeof(xlog_op_header_t)) {
2331 /* no more space in this iclog - push it. */
2332 xlog_state_finish_copy(log, iclog, *record_cnt, *data_cnt);
2333 *record_cnt = 0;
2334 *data_cnt = 0;
2335
2336 spin_lock(&log->l_icloglock);
2337 xlog_state_want_sync(log, iclog);
2338 spin_unlock(&log->l_icloglock);
2339
2340 if (!commit_iclog)
2341 return xlog_state_release_iclog(log, iclog);
2342 ASSERT(flags & XLOG_COMMIT_TRANS);
2343 *commit_iclog = iclog;
2344 }
2345
2346 return 0;
2347}
2348
2349/*
2350 * Write some region out to in-core log
2351 *
2352 * This will be called when writing externally provided regions or when
2353 * writing out a commit record for a given transaction.
2354 *
2355 * General algorithm:
2356 * 1. Find total length of this write. This may include adding to the
2357 * lengths passed in.
2358 * 2. Check whether we violate the tickets reservation.
2359 * 3. While writing to this iclog
2360 * A. Reserve as much space in this iclog as can get
2361 * B. If this is first write, save away start lsn
2362 * C. While writing this region:
2363 * 1. If first write of transaction, write start record
2364 * 2. Write log operation header (header per region)
2365 * 3. Find out if we can fit entire region into this iclog
2366 * 4. Potentially, verify destination memcpy ptr
2367 * 5. Memcpy (partial) region
2368 * 6. If partial copy, release iclog; otherwise, continue
2369 * copying more regions into current iclog
2370 * 4. Mark want sync bit (in simulation mode)
2371 * 5. Release iclog for potential flush to on-disk log.
2372 *
2373 * ERRORS:
2374 * 1. Panic if reservation is overrun. This should never happen since
2375 * reservation amounts are generated internal to the filesystem.
2376 * NOTES:
2377 * 1. Tickets are single threaded data structures.
2378 * 2. The XLOG_END_TRANS & XLOG_CONTINUE_TRANS flags are passed down to the
2379 * syncing routine. When a single log_write region needs to span
2380 * multiple in-core logs, the XLOG_CONTINUE_TRANS bit should be set
2381 * on all log operation writes which don't contain the end of the
2382 * region. The XLOG_END_TRANS bit is used for the in-core log
2383 * operation which contains the end of the continued log_write region.
2384 * 3. When xlog_state_get_iclog_space() grabs the rest of the current iclog,
2385 * we don't really know exactly how much space will be used. As a result,
2386 * we don't update ic_offset until the end when we know exactly how many
2387 * bytes have been written out.
2388 */
2389int
2390xlog_write(
2391 struct xlog *log,
2392 struct xfs_log_vec *log_vector,
2393 struct xlog_ticket *ticket,
2394 xfs_lsn_t *start_lsn,
2395 struct xlog_in_core **commit_iclog,
2396 uint flags)
2397{
2398 struct xlog_in_core *iclog = NULL;
2399 struct xfs_log_iovec *vecp;
2400 struct xfs_log_vec *lv;
2401 int len;
2402 int index;
2403 int partial_copy = 0;
2404 int partial_copy_len = 0;
2405 int contwr = 0;
2406 int record_cnt = 0;
2407 int data_cnt = 0;
2408 int error;
2409
2410 *start_lsn = 0;
2411
2412 len = xlog_write_calc_vec_length(ticket, log_vector);
2413
2414 /*
2415 * Region headers and bytes are already accounted for.
2416 * We only need to take into account start records and
2417 * split regions in this function.
2418 */
2419 if (ticket->t_flags & XLOG_TIC_INITED)
2420 ticket->t_curr_res -= sizeof(xlog_op_header_t);
2421
2422 /*
2423 * Commit record headers need to be accounted for. These
2424 * come in as separate writes so are easy to detect.
2425 */
2426 if (flags & (XLOG_COMMIT_TRANS | XLOG_UNMOUNT_TRANS))
2427 ticket->t_curr_res -= sizeof(xlog_op_header_t);
2428
2429 if (ticket->t_curr_res < 0) {
2430 xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES,
2431 "ctx ticket reservation ran out. Need to up reservation");
2432 xlog_print_tic_res(log->l_mp, ticket);
2433 xfs_force_shutdown(log->l_mp, SHUTDOWN_LOG_IO_ERROR);
2434 }
2435
2436 index = 0;
2437 lv = log_vector;
2438 vecp = lv->lv_iovecp;
2439 while (lv && (!lv->lv_niovecs || index < lv->lv_niovecs)) {
2440 void *ptr;
2441 int log_offset;
2442
2443 error = xlog_state_get_iclog_space(log, len, &iclog, ticket,
2444 &contwr, &log_offset);
2445 if (error)
2446 return error;
2447
2448 ASSERT(log_offset <= iclog->ic_size - 1);
2449 ptr = iclog->ic_datap + log_offset;
2450
2451 /* start_lsn is the first lsn written to. That's all we need. */
2452 if (!*start_lsn)
2453 *start_lsn = be64_to_cpu(iclog->ic_header.h_lsn);
2454
2455 /*
2456 * This loop writes out as many regions as can fit in the amount
2457 * of space which was allocated by xlog_state_get_iclog_space().
2458 */
2459 while (lv && (!lv->lv_niovecs || index < lv->lv_niovecs)) {
2460 struct xfs_log_iovec *reg;
2461 struct xlog_op_header *ophdr;
2462 int start_rec_copy;
2463 int copy_len;
2464 int copy_off;
2465 bool ordered = false;
2466
2467 /* ordered log vectors have no regions to write */
2468 if (lv->lv_buf_len == XFS_LOG_VEC_ORDERED) {
2469 ASSERT(lv->lv_niovecs == 0);
2470 ordered = true;
2471 goto next_lv;
2472 }
2473
2474 reg = &vecp[index];
2475 ASSERT(reg->i_len % sizeof(int32_t) == 0);
2476 ASSERT((unsigned long)ptr % sizeof(int32_t) == 0);
2477
2478 start_rec_copy = xlog_write_start_rec(ptr, ticket);
2479 if (start_rec_copy) {
2480 record_cnt++;
2481 xlog_write_adv_cnt(&ptr, &len, &log_offset,
2482 start_rec_copy);
2483 }
2484
2485 ophdr = xlog_write_setup_ophdr(log, ptr, ticket, flags);
2486 if (!ophdr)
2487 return -EIO;
2488
2489 xlog_write_adv_cnt(&ptr, &len, &log_offset,
2490 sizeof(struct xlog_op_header));
2491
2492 len += xlog_write_setup_copy(ticket, ophdr,
2493 iclog->ic_size-log_offset,
2494 reg->i_len,
2495 ©_off, ©_len,
2496 &partial_copy,
2497 &partial_copy_len);
2498 xlog_verify_dest_ptr(log, ptr);
2499
2500 /*
2501 * Copy region.
2502 *
2503 * Unmount records just log an opheader, so can have
2504 * empty payloads with no data region to copy. Hence we
2505 * only copy the payload if the vector says it has data
2506 * to copy.
2507 */
2508 ASSERT(copy_len >= 0);
2509 if (copy_len > 0) {
2510 memcpy(ptr, reg->i_addr + copy_off, copy_len);
2511 xlog_write_adv_cnt(&ptr, &len, &log_offset,
2512 copy_len);
2513 }
2514 copy_len += start_rec_copy + sizeof(xlog_op_header_t);
2515 record_cnt++;
2516 data_cnt += contwr ? copy_len : 0;
2517
2518 error = xlog_write_copy_finish(log, iclog, flags,
2519 &record_cnt, &data_cnt,
2520 &partial_copy,
2521 &partial_copy_len,
2522 log_offset,
2523 commit_iclog);
2524 if (error)
2525 return error;
2526
2527 /*
2528 * if we had a partial copy, we need to get more iclog
2529 * space but we don't want to increment the region
2530 * index because there is still more is this region to
2531 * write.
2532 *
2533 * If we completed writing this region, and we flushed
2534 * the iclog (indicated by resetting of the record
2535 * count), then we also need to get more log space. If
2536 * this was the last record, though, we are done and
2537 * can just return.
2538 */
2539 if (partial_copy)
2540 break;
2541
2542 if (++index == lv->lv_niovecs) {
2543next_lv:
2544 lv = lv->lv_next;
2545 index = 0;
2546 if (lv)
2547 vecp = lv->lv_iovecp;
2548 }
2549 if (record_cnt == 0 && !ordered) {
2550 if (!lv)
2551 return 0;
2552 break;
2553 }
2554 }
2555 }
2556
2557 ASSERT(len == 0);
2558
2559 xlog_state_finish_copy(log, iclog, record_cnt, data_cnt);
2560 if (!commit_iclog)
2561 return xlog_state_release_iclog(log, iclog);
2562
2563 ASSERT(flags & XLOG_COMMIT_TRANS);
2564 *commit_iclog = iclog;
2565 return 0;
2566}
2567
2568
2569/*****************************************************************************
2570 *
2571 * State Machine functions
2572 *
2573 *****************************************************************************
2574 */
2575
2576/* Clean iclogs starting from the head. This ordering must be
2577 * maintained, so an iclog doesn't become ACTIVE beyond one that
2578 * is SYNCING. This is also required to maintain the notion that we use
2579 * a ordered wait queue to hold off would be writers to the log when every
2580 * iclog is trying to sync to disk.
2581 *
2582 * State Change: DIRTY -> ACTIVE
2583 */
2584STATIC void
2585xlog_state_clean_log(
2586 struct xlog *log)
2587{
2588 xlog_in_core_t *iclog;
2589 int changed = 0;
2590
2591 iclog = log->l_iclog;
2592 do {
2593 if (iclog->ic_state == XLOG_STATE_DIRTY) {
2594 iclog->ic_state = XLOG_STATE_ACTIVE;
2595 iclog->ic_offset = 0;
2596 ASSERT(iclog->ic_callback == NULL);
2597 /*
2598 * If the number of ops in this iclog indicate it just
2599 * contains the dummy transaction, we can
2600 * change state into IDLE (the second time around).
2601 * Otherwise we should change the state into
2602 * NEED a dummy.
2603 * We don't need to cover the dummy.
2604 */
2605 if (!changed &&
2606 (be32_to_cpu(iclog->ic_header.h_num_logops) ==
2607 XLOG_COVER_OPS)) {
2608 changed = 1;
2609 } else {
2610 /*
2611 * We have two dirty iclogs so start over
2612 * This could also be num of ops indicates
2613 * this is not the dummy going out.
2614 */
2615 changed = 2;
2616 }
2617 iclog->ic_header.h_num_logops = 0;
2618 memset(iclog->ic_header.h_cycle_data, 0,
2619 sizeof(iclog->ic_header.h_cycle_data));
2620 iclog->ic_header.h_lsn = 0;
2621 } else if (iclog->ic_state == XLOG_STATE_ACTIVE)
2622 /* do nothing */;
2623 else
2624 break; /* stop cleaning */
2625 iclog = iclog->ic_next;
2626 } while (iclog != log->l_iclog);
2627
2628 /* log is locked when we are called */
2629 /*
2630 * Change state for the dummy log recording.
2631 * We usually go to NEED. But we go to NEED2 if the changed indicates
2632 * we are done writing the dummy record.
2633 * If we are done with the second dummy recored (DONE2), then
2634 * we go to IDLE.
2635 */
2636 if (changed) {
2637 switch (log->l_covered_state) {
2638 case XLOG_STATE_COVER_IDLE:
2639 case XLOG_STATE_COVER_NEED:
2640 case XLOG_STATE_COVER_NEED2:
2641 log->l_covered_state = XLOG_STATE_COVER_NEED;
2642 break;
2643
2644 case XLOG_STATE_COVER_DONE:
2645 if (changed == 1)
2646 log->l_covered_state = XLOG_STATE_COVER_NEED2;
2647 else
2648 log->l_covered_state = XLOG_STATE_COVER_NEED;
2649 break;
2650
2651 case XLOG_STATE_COVER_DONE2:
2652 if (changed == 1)
2653 log->l_covered_state = XLOG_STATE_COVER_IDLE;
2654 else
2655 log->l_covered_state = XLOG_STATE_COVER_NEED;
2656 break;
2657
2658 default:
2659 ASSERT(0);
2660 }
2661 }
2662} /* xlog_state_clean_log */
2663
2664STATIC xfs_lsn_t
2665xlog_get_lowest_lsn(
2666 struct xlog *log)
2667{
2668 xlog_in_core_t *lsn_log;
2669 xfs_lsn_t lowest_lsn, lsn;
2670
2671 lsn_log = log->l_iclog;
2672 lowest_lsn = 0;
2673 do {
2674 if (!(lsn_log->ic_state & (XLOG_STATE_ACTIVE|XLOG_STATE_DIRTY))) {
2675 lsn = be64_to_cpu(lsn_log->ic_header.h_lsn);
2676 if ((lsn && !lowest_lsn) ||
2677 (XFS_LSN_CMP(lsn, lowest_lsn) < 0)) {
2678 lowest_lsn = lsn;
2679 }
2680 }
2681 lsn_log = lsn_log->ic_next;
2682 } while (lsn_log != log->l_iclog);
2683 return lowest_lsn;
2684}
2685
2686
2687STATIC void
2688xlog_state_do_callback(
2689 struct xlog *log,
2690 int aborted,
2691 struct xlog_in_core *ciclog)
2692{
2693 xlog_in_core_t *iclog;
2694 xlog_in_core_t *first_iclog; /* used to know when we've
2695 * processed all iclogs once */
2696 xfs_log_callback_t *cb, *cb_next;
2697 int flushcnt = 0;
2698 xfs_lsn_t lowest_lsn;
2699 int ioerrors; /* counter: iclogs with errors */
2700 int loopdidcallbacks; /* flag: inner loop did callbacks*/
2701 int funcdidcallbacks; /* flag: function did callbacks */
2702 int repeats; /* for issuing console warnings if
2703 * looping too many times */
2704 int wake = 0;
2705
2706 spin_lock(&log->l_icloglock);
2707 first_iclog = iclog = log->l_iclog;
2708 ioerrors = 0;
2709 funcdidcallbacks = 0;
2710 repeats = 0;
2711
2712 do {
2713 /*
2714 * Scan all iclogs starting with the one pointed to by the
2715 * log. Reset this starting point each time the log is
2716 * unlocked (during callbacks).
2717 *
2718 * Keep looping through iclogs until one full pass is made
2719 * without running any callbacks.
2720 */
2721 first_iclog = log->l_iclog;
2722 iclog = log->l_iclog;
2723 loopdidcallbacks = 0;
2724 repeats++;
2725
2726 do {
2727
2728 /* skip all iclogs in the ACTIVE & DIRTY states */
2729 if (iclog->ic_state &
2730 (XLOG_STATE_ACTIVE|XLOG_STATE_DIRTY)) {
2731 iclog = iclog->ic_next;
2732 continue;
2733 }
2734
2735 /*
2736 * Between marking a filesystem SHUTDOWN and stopping
2737 * the log, we do flush all iclogs to disk (if there
2738 * wasn't a log I/O error). So, we do want things to
2739 * go smoothly in case of just a SHUTDOWN w/o a
2740 * LOG_IO_ERROR.
2741 */
2742 if (!(iclog->ic_state & XLOG_STATE_IOERROR)) {
2743 /*
2744 * Can only perform callbacks in order. Since
2745 * this iclog is not in the DONE_SYNC/
2746 * DO_CALLBACK state, we skip the rest and
2747 * just try to clean up. If we set our iclog
2748 * to DO_CALLBACK, we will not process it when
2749 * we retry since a previous iclog is in the
2750 * CALLBACK and the state cannot change since
2751 * we are holding the l_icloglock.
2752 */
2753 if (!(iclog->ic_state &
2754 (XLOG_STATE_DONE_SYNC |
2755 XLOG_STATE_DO_CALLBACK))) {
2756 if (ciclog && (ciclog->ic_state ==
2757 XLOG_STATE_DONE_SYNC)) {
2758 ciclog->ic_state = XLOG_STATE_DO_CALLBACK;
2759 }
2760 break;
2761 }
2762 /*
2763 * We now have an iclog that is in either the
2764 * DO_CALLBACK or DONE_SYNC states. The other
2765 * states (WANT_SYNC, SYNCING, or CALLBACK were
2766 * caught by the above if and are going to
2767 * clean (i.e. we aren't doing their callbacks)
2768 * see the above if.
2769 */
2770
2771 /*
2772 * We will do one more check here to see if we
2773 * have chased our tail around.
2774 */
2775
2776 lowest_lsn = xlog_get_lowest_lsn(log);
2777 if (lowest_lsn &&
2778 XFS_LSN_CMP(lowest_lsn,
2779 be64_to_cpu(iclog->ic_header.h_lsn)) < 0) {
2780 iclog = iclog->ic_next;
2781 continue; /* Leave this iclog for
2782 * another thread */
2783 }
2784
2785 iclog->ic_state = XLOG_STATE_CALLBACK;
2786
2787
2788 /*
2789 * Completion of a iclog IO does not imply that
2790 * a transaction has completed, as transactions
2791 * can be large enough to span many iclogs. We
2792 * cannot change the tail of the log half way
2793 * through a transaction as this may be the only
2794 * transaction in the log and moving th etail to
2795 * point to the middle of it will prevent
2796 * recovery from finding the start of the
2797 * transaction. Hence we should only update the
2798 * last_sync_lsn if this iclog contains
2799 * transaction completion callbacks on it.
2800 *
2801 * We have to do this before we drop the
2802 * icloglock to ensure we are the only one that
2803 * can update it.
2804 */
2805 ASSERT(XFS_LSN_CMP(atomic64_read(&log->l_last_sync_lsn),
2806 be64_to_cpu(iclog->ic_header.h_lsn)) <= 0);
2807 if (iclog->ic_callback)
2808 atomic64_set(&log->l_last_sync_lsn,
2809 be64_to_cpu(iclog->ic_header.h_lsn));
2810
2811 } else
2812 ioerrors++;
2813
2814 spin_unlock(&log->l_icloglock);
2815
2816 /*
2817 * Keep processing entries in the callback list until
2818 * we come around and it is empty. We need to
2819 * atomically see that the list is empty and change the
2820 * state to DIRTY so that we don't miss any more
2821 * callbacks being added.
2822 */
2823 spin_lock(&iclog->ic_callback_lock);
2824 cb = iclog->ic_callback;
2825 while (cb) {
2826 iclog->ic_callback_tail = &(iclog->ic_callback);
2827 iclog->ic_callback = NULL;
2828 spin_unlock(&iclog->ic_callback_lock);
2829
2830 /* perform callbacks in the order given */
2831 for (; cb; cb = cb_next) {
2832 cb_next = cb->cb_next;
2833 cb->cb_func(cb->cb_arg, aborted);
2834 }
2835 spin_lock(&iclog->ic_callback_lock);
2836 cb = iclog->ic_callback;
2837 }
2838
2839 loopdidcallbacks++;
2840 funcdidcallbacks++;
2841
2842 spin_lock(&log->l_icloglock);
2843 ASSERT(iclog->ic_callback == NULL);
2844 spin_unlock(&iclog->ic_callback_lock);
2845 if (!(iclog->ic_state & XLOG_STATE_IOERROR))
2846 iclog->ic_state = XLOG_STATE_DIRTY;
2847
2848 /*
2849 * Transition from DIRTY to ACTIVE if applicable.
2850 * NOP if STATE_IOERROR.
2851 */
2852 xlog_state_clean_log(log);
2853
2854 /* wake up threads waiting in xfs_log_force() */
2855 wake_up_all(&iclog->ic_force_wait);
2856
2857 iclog = iclog->ic_next;
2858 } while (first_iclog != iclog);
2859
2860 if (repeats > 5000) {
2861 flushcnt += repeats;
2862 repeats = 0;
2863 xfs_warn(log->l_mp,
2864 "%s: possible infinite loop (%d iterations)",
2865 __func__, flushcnt);
2866 }
2867 } while (!ioerrors && loopdidcallbacks);
2868
2869#ifdef DEBUG
2870 /*
2871 * Make one last gasp attempt to see if iclogs are being left in limbo.
2872 * If the above loop finds an iclog earlier than the current iclog and
2873 * in one of the syncing states, the current iclog is put into
2874 * DO_CALLBACK and the callbacks are deferred to the completion of the
2875 * earlier iclog. Walk the iclogs in order and make sure that no iclog
2876 * is in DO_CALLBACK unless an earlier iclog is in one of the syncing
2877 * states.
2878 *
2879 * Note that SYNCING|IOABORT is a valid state so we cannot just check
2880 * for ic_state == SYNCING.
2881 */
2882 if (funcdidcallbacks) {
2883 first_iclog = iclog = log->l_iclog;
2884 do {
2885 ASSERT(iclog->ic_state != XLOG_STATE_DO_CALLBACK);
2886 /*
2887 * Terminate the loop if iclogs are found in states
2888 * which will cause other threads to clean up iclogs.
2889 *
2890 * SYNCING - i/o completion will go through logs
2891 * DONE_SYNC - interrupt thread should be waiting for
2892 * l_icloglock
2893 * IOERROR - give up hope all ye who enter here
2894 */
2895 if (iclog->ic_state == XLOG_STATE_WANT_SYNC ||
2896 iclog->ic_state & XLOG_STATE_SYNCING ||
2897 iclog->ic_state == XLOG_STATE_DONE_SYNC ||
2898 iclog->ic_state == XLOG_STATE_IOERROR )
2899 break;
2900 iclog = iclog->ic_next;
2901 } while (first_iclog != iclog);
2902 }
2903#endif
2904
2905 if (log->l_iclog->ic_state & (XLOG_STATE_ACTIVE|XLOG_STATE_IOERROR))
2906 wake = 1;
2907 spin_unlock(&log->l_icloglock);
2908
2909 if (wake)
2910 wake_up_all(&log->l_flush_wait);
2911}
2912
2913
2914/*
2915 * Finish transitioning this iclog to the dirty state.
2916 *
2917 * Make sure that we completely execute this routine only when this is
2918 * the last call to the iclog. There is a good chance that iclog flushes,
2919 * when we reach the end of the physical log, get turned into 2 separate
2920 * calls to bwrite. Hence, one iclog flush could generate two calls to this
2921 * routine. By using the reference count bwritecnt, we guarantee that only
2922 * the second completion goes through.
2923 *
2924 * Callbacks could take time, so they are done outside the scope of the
2925 * global state machine log lock.
2926 */
2927STATIC void
2928xlog_state_done_syncing(
2929 xlog_in_core_t *iclog,
2930 int aborted)
2931{
2932 struct xlog *log = iclog->ic_log;
2933
2934 spin_lock(&log->l_icloglock);
2935
2936 ASSERT(iclog->ic_state == XLOG_STATE_SYNCING ||
2937 iclog->ic_state == XLOG_STATE_IOERROR);
2938 ASSERT(atomic_read(&iclog->ic_refcnt) == 0);
2939 ASSERT(iclog->ic_bwritecnt == 1 || iclog->ic_bwritecnt == 2);
2940
2941
2942 /*
2943 * If we got an error, either on the first buffer, or in the case of
2944 * split log writes, on the second, we mark ALL iclogs STATE_IOERROR,
2945 * and none should ever be attempted to be written to disk
2946 * again.
2947 */
2948 if (iclog->ic_state != XLOG_STATE_IOERROR) {
2949 if (--iclog->ic_bwritecnt == 1) {
2950 spin_unlock(&log->l_icloglock);
2951 return;
2952 }
2953 iclog->ic_state = XLOG_STATE_DONE_SYNC;
2954 }
2955
2956 /*
2957 * Someone could be sleeping prior to writing out the next
2958 * iclog buffer, we wake them all, one will get to do the
2959 * I/O, the others get to wait for the result.
2960 */
2961 wake_up_all(&iclog->ic_write_wait);
2962 spin_unlock(&log->l_icloglock);
2963 xlog_state_do_callback(log, aborted, iclog); /* also cleans log */
2964} /* xlog_state_done_syncing */
2965
2966
2967/*
2968 * If the head of the in-core log ring is not (ACTIVE or DIRTY), then we must
2969 * sleep. We wait on the flush queue on the head iclog as that should be
2970 * the first iclog to complete flushing. Hence if all iclogs are syncing,
2971 * we will wait here and all new writes will sleep until a sync completes.
2972 *
2973 * The in-core logs are used in a circular fashion. They are not used
2974 * out-of-order even when an iclog past the head is free.
2975 *
2976 * return:
2977 * * log_offset where xlog_write() can start writing into the in-core
2978 * log's data space.
2979 * * in-core log pointer to which xlog_write() should write.
2980 * * boolean indicating this is a continued write to an in-core log.
2981 * If this is the last write, then the in-core log's offset field
2982 * needs to be incremented, depending on the amount of data which
2983 * is copied.
2984 */
2985STATIC int
2986xlog_state_get_iclog_space(
2987 struct xlog *log,
2988 int len,
2989 struct xlog_in_core **iclogp,
2990 struct xlog_ticket *ticket,
2991 int *continued_write,
2992 int *logoffsetp)
2993{
2994 int log_offset;
2995 xlog_rec_header_t *head;
2996 xlog_in_core_t *iclog;
2997 int error;
2998
2999restart:
3000 spin_lock(&log->l_icloglock);
3001 if (XLOG_FORCED_SHUTDOWN(log)) {
3002 spin_unlock(&log->l_icloglock);
3003 return -EIO;
3004 }
3005
3006 iclog = log->l_iclog;
3007 if (iclog->ic_state != XLOG_STATE_ACTIVE) {
3008 XFS_STATS_INC(log->l_mp, xs_log_noiclogs);
3009
3010 /* Wait for log writes to have flushed */
3011 xlog_wait(&log->l_flush_wait, &log->l_icloglock);
3012 goto restart;
3013 }
3014
3015 head = &iclog->ic_header;
3016
3017 atomic_inc(&iclog->ic_refcnt); /* prevents sync */
3018 log_offset = iclog->ic_offset;
3019
3020 /* On the 1st write to an iclog, figure out lsn. This works
3021 * if iclogs marked XLOG_STATE_WANT_SYNC always write out what they are
3022 * committing to. If the offset is set, that's how many blocks
3023 * must be written.
3024 */
3025 if (log_offset == 0) {
3026 ticket->t_curr_res -= log->l_iclog_hsize;
3027 xlog_tic_add_region(ticket,
3028 log->l_iclog_hsize,
3029 XLOG_REG_TYPE_LRHEADER);
3030 head->h_cycle = cpu_to_be32(log->l_curr_cycle);
3031 head->h_lsn = cpu_to_be64(
3032 xlog_assign_lsn(log->l_curr_cycle, log->l_curr_block));
3033 ASSERT(log->l_curr_block >= 0);
3034 }
3035
3036 /* If there is enough room to write everything, then do it. Otherwise,
3037 * claim the rest of the region and make sure the XLOG_STATE_WANT_SYNC
3038 * bit is on, so this will get flushed out. Don't update ic_offset
3039 * until you know exactly how many bytes get copied. Therefore, wait
3040 * until later to update ic_offset.
3041 *
3042 * xlog_write() algorithm assumes that at least 2 xlog_op_header_t's
3043 * can fit into remaining data section.
3044 */
3045 if (iclog->ic_size - iclog->ic_offset < 2*sizeof(xlog_op_header_t)) {
3046 xlog_state_switch_iclogs(log, iclog, iclog->ic_size);
3047
3048 /*
3049 * If I'm the only one writing to this iclog, sync it to disk.
3050 * We need to do an atomic compare and decrement here to avoid
3051 * racing with concurrent atomic_dec_and_lock() calls in
3052 * xlog_state_release_iclog() when there is more than one
3053 * reference to the iclog.
3054 */
3055 if (!atomic_add_unless(&iclog->ic_refcnt, -1, 1)) {
3056 /* we are the only one */
3057 spin_unlock(&log->l_icloglock);
3058 error = xlog_state_release_iclog(log, iclog);
3059 if (error)
3060 return error;
3061 } else {
3062 spin_unlock(&log->l_icloglock);
3063 }
3064 goto restart;
3065 }
3066
3067 /* Do we have enough room to write the full amount in the remainder
3068 * of this iclog? Or must we continue a write on the next iclog and
3069 * mark this iclog as completely taken? In the case where we switch
3070 * iclogs (to mark it taken), this particular iclog will release/sync
3071 * to disk in xlog_write().
3072 */
3073 if (len <= iclog->ic_size - iclog->ic_offset) {
3074 *continued_write = 0;
3075 iclog->ic_offset += len;
3076 } else {
3077 *continued_write = 1;
3078 xlog_state_switch_iclogs(log, iclog, iclog->ic_size);
3079 }
3080 *iclogp = iclog;
3081
3082 ASSERT(iclog->ic_offset <= iclog->ic_size);
3083 spin_unlock(&log->l_icloglock);
3084
3085 *logoffsetp = log_offset;
3086 return 0;
3087} /* xlog_state_get_iclog_space */
3088
3089/* The first cnt-1 times through here we don't need to
3090 * move the grant write head because the permanent
3091 * reservation has reserved cnt times the unit amount.
3092 * Release part of current permanent unit reservation and
3093 * reset current reservation to be one units worth. Also
3094 * move grant reservation head forward.
3095 */
3096STATIC void
3097xlog_regrant_reserve_log_space(
3098 struct xlog *log,
3099 struct xlog_ticket *ticket)
3100{
3101 trace_xfs_log_regrant_reserve_enter(log, ticket);
3102
3103 if (ticket->t_cnt > 0)
3104 ticket->t_cnt--;
3105
3106 xlog_grant_sub_space(log, &log->l_reserve_head.grant,
3107 ticket->t_curr_res);
3108 xlog_grant_sub_space(log, &log->l_write_head.grant,
3109 ticket->t_curr_res);
3110 ticket->t_curr_res = ticket->t_unit_res;
3111 xlog_tic_reset_res(ticket);
3112
3113 trace_xfs_log_regrant_reserve_sub(log, ticket);
3114
3115 /* just return if we still have some of the pre-reserved space */
3116 if (ticket->t_cnt > 0)
3117 return;
3118
3119 xlog_grant_add_space(log, &log->l_reserve_head.grant,
3120 ticket->t_unit_res);
3121
3122 trace_xfs_log_regrant_reserve_exit(log, ticket);
3123
3124 ticket->t_curr_res = ticket->t_unit_res;
3125 xlog_tic_reset_res(ticket);
3126} /* xlog_regrant_reserve_log_space */
3127
3128
3129/*
3130 * Give back the space left from a reservation.
3131 *
3132 * All the information we need to make a correct determination of space left
3133 * is present. For non-permanent reservations, things are quite easy. The
3134 * count should have been decremented to zero. We only need to deal with the
3135 * space remaining in the current reservation part of the ticket. If the
3136 * ticket contains a permanent reservation, there may be left over space which
3137 * needs to be released. A count of N means that N-1 refills of the current
3138 * reservation can be done before we need to ask for more space. The first
3139 * one goes to fill up the first current reservation. Once we run out of
3140 * space, the count will stay at zero and the only space remaining will be
3141 * in the current reservation field.
3142 */
3143STATIC void
3144xlog_ungrant_log_space(
3145 struct xlog *log,
3146 struct xlog_ticket *ticket)
3147{
3148 int bytes;
3149
3150 if (ticket->t_cnt > 0)
3151 ticket->t_cnt--;
3152
3153 trace_xfs_log_ungrant_enter(log, ticket);
3154 trace_xfs_log_ungrant_sub(log, ticket);
3155
3156 /*
3157 * If this is a permanent reservation ticket, we may be able to free
3158 * up more space based on the remaining count.
3159 */
3160 bytes = ticket->t_curr_res;
3161 if (ticket->t_cnt > 0) {
3162 ASSERT(ticket->t_flags & XLOG_TIC_PERM_RESERV);
3163 bytes += ticket->t_unit_res*ticket->t_cnt;
3164 }
3165
3166 xlog_grant_sub_space(log, &log->l_reserve_head.grant, bytes);
3167 xlog_grant_sub_space(log, &log->l_write_head.grant, bytes);
3168
3169 trace_xfs_log_ungrant_exit(log, ticket);
3170
3171 xfs_log_space_wake(log->l_mp);
3172}
3173
3174/*
3175 * Flush iclog to disk if this is the last reference to the given iclog and
3176 * the WANT_SYNC bit is set.
3177 *
3178 * When this function is entered, the iclog is not necessarily in the
3179 * WANT_SYNC state. It may be sitting around waiting to get filled.
3180 *
3181 *
3182 */
3183STATIC int
3184xlog_state_release_iclog(
3185 struct xlog *log,
3186 struct xlog_in_core *iclog)
3187{
3188 int sync = 0; /* do we sync? */
3189
3190 if (iclog->ic_state & XLOG_STATE_IOERROR)
3191 return -EIO;
3192
3193 ASSERT(atomic_read(&iclog->ic_refcnt) > 0);
3194 if (!atomic_dec_and_lock(&iclog->ic_refcnt, &log->l_icloglock))
3195 return 0;
3196
3197 if (iclog->ic_state & XLOG_STATE_IOERROR) {
3198 spin_unlock(&log->l_icloglock);
3199 return -EIO;
3200 }
3201 ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE ||
3202 iclog->ic_state == XLOG_STATE_WANT_SYNC);
3203
3204 if (iclog->ic_state == XLOG_STATE_WANT_SYNC) {
3205 /* update tail before writing to iclog */
3206 xfs_lsn_t tail_lsn = xlog_assign_tail_lsn(log->l_mp);
3207 sync++;
3208 iclog->ic_state = XLOG_STATE_SYNCING;
3209 iclog->ic_header.h_tail_lsn = cpu_to_be64(tail_lsn);
3210 xlog_verify_tail_lsn(log, iclog, tail_lsn);
3211 /* cycle incremented when incrementing curr_block */
3212 }
3213 spin_unlock(&log->l_icloglock);
3214
3215 /*
3216 * We let the log lock go, so it's possible that we hit a log I/O
3217 * error or some other SHUTDOWN condition that marks the iclog
3218 * as XLOG_STATE_IOERROR before the bwrite. However, we know that
3219 * this iclog has consistent data, so we ignore IOERROR
3220 * flags after this point.
3221 */
3222 if (sync)
3223 return xlog_sync(log, iclog);
3224 return 0;
3225} /* xlog_state_release_iclog */
3226
3227
3228/*
3229 * This routine will mark the current iclog in the ring as WANT_SYNC
3230 * and move the current iclog pointer to the next iclog in the ring.
3231 * When this routine is called from xlog_state_get_iclog_space(), the
3232 * exact size of the iclog has not yet been determined. All we know is
3233 * that every data block. We have run out of space in this log record.
3234 */
3235STATIC void
3236xlog_state_switch_iclogs(
3237 struct xlog *log,
3238 struct xlog_in_core *iclog,
3239 int eventual_size)
3240{
3241 ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE);
3242 if (!eventual_size)
3243 eventual_size = iclog->ic_offset;
3244 iclog->ic_state = XLOG_STATE_WANT_SYNC;
3245 iclog->ic_header.h_prev_block = cpu_to_be32(log->l_prev_block);
3246 log->l_prev_block = log->l_curr_block;
3247 log->l_prev_cycle = log->l_curr_cycle;
3248
3249 /* roll log?: ic_offset changed later */
3250 log->l_curr_block += BTOBB(eventual_size)+BTOBB(log->l_iclog_hsize);
3251
3252 /* Round up to next log-sunit */
3253 if (xfs_sb_version_haslogv2(&log->l_mp->m_sb) &&
3254 log->l_mp->m_sb.sb_logsunit > 1) {
3255 uint32_t sunit_bb = BTOBB(log->l_mp->m_sb.sb_logsunit);
3256 log->l_curr_block = roundup(log->l_curr_block, sunit_bb);
3257 }
3258
3259 if (log->l_curr_block >= log->l_logBBsize) {
3260 /*
3261 * Rewind the current block before the cycle is bumped to make
3262 * sure that the combined LSN never transiently moves forward
3263 * when the log wraps to the next cycle. This is to support the
3264 * unlocked sample of these fields from xlog_valid_lsn(). Most
3265 * other cases should acquire l_icloglock.
3266 */
3267 log->l_curr_block -= log->l_logBBsize;
3268 ASSERT(log->l_curr_block >= 0);
3269 smp_wmb();
3270 log->l_curr_cycle++;
3271 if (log->l_curr_cycle == XLOG_HEADER_MAGIC_NUM)
3272 log->l_curr_cycle++;
3273 }
3274 ASSERT(iclog == log->l_iclog);
3275 log->l_iclog = iclog->ic_next;
3276} /* xlog_state_switch_iclogs */
3277
3278/*
3279 * Write out all data in the in-core log as of this exact moment in time.
3280 *
3281 * Data may be written to the in-core log during this call. However,
3282 * we don't guarantee this data will be written out. A change from past
3283 * implementation means this routine will *not* write out zero length LRs.
3284 *
3285 * Basically, we try and perform an intelligent scan of the in-core logs.
3286 * If we determine there is no flushable data, we just return. There is no
3287 * flushable data if:
3288 *
3289 * 1. the current iclog is active and has no data; the previous iclog
3290 * is in the active or dirty state.
3291 * 2. the current iclog is drity, and the previous iclog is in the
3292 * active or dirty state.
3293 *
3294 * We may sleep if:
3295 *
3296 * 1. the current iclog is not in the active nor dirty state.
3297 * 2. the current iclog dirty, and the previous iclog is not in the
3298 * active nor dirty state.
3299 * 3. the current iclog is active, and there is another thread writing
3300 * to this particular iclog.
3301 * 4. a) the current iclog is active and has no other writers
3302 * b) when we return from flushing out this iclog, it is still
3303 * not in the active nor dirty state.
3304 */
3305int
3306xfs_log_force(
3307 struct xfs_mount *mp,
3308 uint flags)
3309{
3310 struct xlog *log = mp->m_log;
3311 struct xlog_in_core *iclog;
3312 xfs_lsn_t lsn;
3313
3314 XFS_STATS_INC(mp, xs_log_force);
3315 trace_xfs_log_force(mp, 0, _RET_IP_);
3316
3317 xlog_cil_force(log);
3318
3319 spin_lock(&log->l_icloglock);
3320 iclog = log->l_iclog;
3321 if (iclog->ic_state & XLOG_STATE_IOERROR)
3322 goto out_error;
3323
3324 if (iclog->ic_state == XLOG_STATE_DIRTY ||
3325 (iclog->ic_state == XLOG_STATE_ACTIVE &&
3326 atomic_read(&iclog->ic_refcnt) == 0 && iclog->ic_offset == 0)) {
3327 /*
3328 * If the head is dirty or (active and empty), then we need to
3329 * look at the previous iclog.
3330 *
3331 * If the previous iclog is active or dirty we are done. There
3332 * is nothing to sync out. Otherwise, we attach ourselves to the
3333 * previous iclog and go to sleep.
3334 */
3335 iclog = iclog->ic_prev;
3336 if (iclog->ic_state == XLOG_STATE_ACTIVE ||
3337 iclog->ic_state == XLOG_STATE_DIRTY)
3338 goto out_unlock;
3339 } else if (iclog->ic_state == XLOG_STATE_ACTIVE) {
3340 if (atomic_read(&iclog->ic_refcnt) == 0) {
3341 /*
3342 * We are the only one with access to this iclog.
3343 *
3344 * Flush it out now. There should be a roundoff of zero
3345 * to show that someone has already taken care of the
3346 * roundoff from the previous sync.
3347 */
3348 atomic_inc(&iclog->ic_refcnt);
3349 lsn = be64_to_cpu(iclog->ic_header.h_lsn);
3350 xlog_state_switch_iclogs(log, iclog, 0);
3351 spin_unlock(&log->l_icloglock);
3352
3353 if (xlog_state_release_iclog(log, iclog))
3354 return -EIO;
3355
3356 spin_lock(&log->l_icloglock);
3357 if (be64_to_cpu(iclog->ic_header.h_lsn) != lsn ||
3358 iclog->ic_state == XLOG_STATE_DIRTY)
3359 goto out_unlock;
3360 } else {
3361 /*
3362 * Someone else is writing to this iclog.
3363 *
3364 * Use its call to flush out the data. However, the
3365 * other thread may not force out this LR, so we mark
3366 * it WANT_SYNC.
3367 */
3368 xlog_state_switch_iclogs(log, iclog, 0);
3369 }
3370 } else {
3371 /*
3372 * If the head iclog is not active nor dirty, we just attach
3373 * ourselves to the head and go to sleep if necessary.
3374 */
3375 ;
3376 }
3377
3378 if (!(flags & XFS_LOG_SYNC))
3379 goto out_unlock;
3380
3381 if (iclog->ic_state & XLOG_STATE_IOERROR)
3382 goto out_error;
3383 XFS_STATS_INC(mp, xs_log_force_sleep);
3384 xlog_wait(&iclog->ic_force_wait, &log->l_icloglock);
3385 if (iclog->ic_state & XLOG_STATE_IOERROR)
3386 return -EIO;
3387 return 0;
3388
3389out_unlock:
3390 spin_unlock(&log->l_icloglock);
3391 return 0;
3392out_error:
3393 spin_unlock(&log->l_icloglock);
3394 return -EIO;
3395}
3396
3397static int
3398__xfs_log_force_lsn(
3399 struct xfs_mount *mp,
3400 xfs_lsn_t lsn,
3401 uint flags,
3402 int *log_flushed,
3403 bool already_slept)
3404{
3405 struct xlog *log = mp->m_log;
3406 struct xlog_in_core *iclog;
3407
3408 spin_lock(&log->l_icloglock);
3409 iclog = log->l_iclog;
3410 if (iclog->ic_state & XLOG_STATE_IOERROR)
3411 goto out_error;
3412
3413 while (be64_to_cpu(iclog->ic_header.h_lsn) != lsn) {
3414 iclog = iclog->ic_next;
3415 if (iclog == log->l_iclog)
3416 goto out_unlock;
3417 }
3418
3419 if (iclog->ic_state == XLOG_STATE_DIRTY)
3420 goto out_unlock;
3421
3422 if (iclog->ic_state == XLOG_STATE_ACTIVE) {
3423 /*
3424 * We sleep here if we haven't already slept (e.g. this is the
3425 * first time we've looked at the correct iclog buf) and the
3426 * buffer before us is going to be sync'ed. The reason for this
3427 * is that if we are doing sync transactions here, by waiting
3428 * for the previous I/O to complete, we can allow a few more
3429 * transactions into this iclog before we close it down.
3430 *
3431 * Otherwise, we mark the buffer WANT_SYNC, and bump up the
3432 * refcnt so we can release the log (which drops the ref count).
3433 * The state switch keeps new transaction commits from using
3434 * this buffer. When the current commits finish writing into
3435 * the buffer, the refcount will drop to zero and the buffer
3436 * will go out then.
3437 */
3438 if (!already_slept &&
3439 (iclog->ic_prev->ic_state &
3440 (XLOG_STATE_WANT_SYNC | XLOG_STATE_SYNCING))) {
3441 ASSERT(!(iclog->ic_state & XLOG_STATE_IOERROR));
3442
3443 XFS_STATS_INC(mp, xs_log_force_sleep);
3444
3445 xlog_wait(&iclog->ic_prev->ic_write_wait,
3446 &log->l_icloglock);
3447 return -EAGAIN;
3448 }
3449 atomic_inc(&iclog->ic_refcnt);
3450 xlog_state_switch_iclogs(log, iclog, 0);
3451 spin_unlock(&log->l_icloglock);
3452 if (xlog_state_release_iclog(log, iclog))
3453 return -EIO;
3454 if (log_flushed)
3455 *log_flushed = 1;
3456 spin_lock(&log->l_icloglock);
3457 }
3458
3459 if (!(flags & XFS_LOG_SYNC) ||
3460 (iclog->ic_state & (XLOG_STATE_ACTIVE | XLOG_STATE_DIRTY)))
3461 goto out_unlock;
3462
3463 if (iclog->ic_state & XLOG_STATE_IOERROR)
3464 goto out_error;
3465
3466 XFS_STATS_INC(mp, xs_log_force_sleep);
3467 xlog_wait(&iclog->ic_force_wait, &log->l_icloglock);
3468 if (iclog->ic_state & XLOG_STATE_IOERROR)
3469 return -EIO;
3470 return 0;
3471
3472out_unlock:
3473 spin_unlock(&log->l_icloglock);
3474 return 0;
3475out_error:
3476 spin_unlock(&log->l_icloglock);
3477 return -EIO;
3478}
3479
3480/*
3481 * Force the in-core log to disk for a specific LSN.
3482 *
3483 * Find in-core log with lsn.
3484 * If it is in the DIRTY state, just return.
3485 * If it is in the ACTIVE state, move the in-core log into the WANT_SYNC
3486 * state and go to sleep or return.
3487 * If it is in any other state, go to sleep or return.
3488 *
3489 * Synchronous forces are implemented with a wait queue. All callers trying
3490 * to force a given lsn to disk must wait on the queue attached to the
3491 * specific in-core log. When given in-core log finally completes its write
3492 * to disk, that thread will wake up all threads waiting on the queue.
3493 */
3494int
3495xfs_log_force_lsn(
3496 struct xfs_mount *mp,
3497 xfs_lsn_t lsn,
3498 uint flags,
3499 int *log_flushed)
3500{
3501 int ret;
3502 ASSERT(lsn != 0);
3503
3504 XFS_STATS_INC(mp, xs_log_force);
3505 trace_xfs_log_force(mp, lsn, _RET_IP_);
3506
3507 lsn = xlog_cil_force_lsn(mp->m_log, lsn);
3508 if (lsn == NULLCOMMITLSN)
3509 return 0;
3510
3511 ret = __xfs_log_force_lsn(mp, lsn, flags, log_flushed, false);
3512 if (ret == -EAGAIN)
3513 ret = __xfs_log_force_lsn(mp, lsn, flags, log_flushed, true);
3514 return ret;
3515}
3516
3517/*
3518 * Called when we want to mark the current iclog as being ready to sync to
3519 * disk.
3520 */
3521STATIC void
3522xlog_state_want_sync(
3523 struct xlog *log,
3524 struct xlog_in_core *iclog)
3525{
3526 assert_spin_locked(&log->l_icloglock);
3527
3528 if (iclog->ic_state == XLOG_STATE_ACTIVE) {
3529 xlog_state_switch_iclogs(log, iclog, 0);
3530 } else {
3531 ASSERT(iclog->ic_state &
3532 (XLOG_STATE_WANT_SYNC|XLOG_STATE_IOERROR));
3533 }
3534}
3535
3536
3537/*****************************************************************************
3538 *
3539 * TICKET functions
3540 *
3541 *****************************************************************************
3542 */
3543
3544/*
3545 * Free a used ticket when its refcount falls to zero.
3546 */
3547void
3548xfs_log_ticket_put(
3549 xlog_ticket_t *ticket)
3550{
3551 ASSERT(atomic_read(&ticket->t_ref) > 0);
3552 if (atomic_dec_and_test(&ticket->t_ref))
3553 kmem_zone_free(xfs_log_ticket_zone, ticket);
3554}
3555
3556xlog_ticket_t *
3557xfs_log_ticket_get(
3558 xlog_ticket_t *ticket)
3559{
3560 ASSERT(atomic_read(&ticket->t_ref) > 0);
3561 atomic_inc(&ticket->t_ref);
3562 return ticket;
3563}
3564
3565/*
3566 * Figure out the total log space unit (in bytes) that would be
3567 * required for a log ticket.
3568 */
3569int
3570xfs_log_calc_unit_res(
3571 struct xfs_mount *mp,
3572 int unit_bytes)
3573{
3574 struct xlog *log = mp->m_log;
3575 int iclog_space;
3576 uint num_headers;
3577
3578 /*
3579 * Permanent reservations have up to 'cnt'-1 active log operations
3580 * in the log. A unit in this case is the amount of space for one
3581 * of these log operations. Normal reservations have a cnt of 1
3582 * and their unit amount is the total amount of space required.
3583 *
3584 * The following lines of code account for non-transaction data
3585 * which occupy space in the on-disk log.
3586 *
3587 * Normal form of a transaction is:
3588 * <oph><trans-hdr><start-oph><reg1-oph><reg1><reg2-oph>...<commit-oph>
3589 * and then there are LR hdrs, split-recs and roundoff at end of syncs.
3590 *
3591 * We need to account for all the leadup data and trailer data
3592 * around the transaction data.
3593 * And then we need to account for the worst case in terms of using
3594 * more space.
3595 * The worst case will happen if:
3596 * - the placement of the transaction happens to be such that the
3597 * roundoff is at its maximum
3598 * - the transaction data is synced before the commit record is synced
3599 * i.e. <transaction-data><roundoff> | <commit-rec><roundoff>
3600 * Therefore the commit record is in its own Log Record.
3601 * This can happen as the commit record is called with its
3602 * own region to xlog_write().
3603 * This then means that in the worst case, roundoff can happen for
3604 * the commit-rec as well.
3605 * The commit-rec is smaller than padding in this scenario and so it is
3606 * not added separately.
3607 */
3608
3609 /* for trans header */
3610 unit_bytes += sizeof(xlog_op_header_t);
3611 unit_bytes += sizeof(xfs_trans_header_t);
3612
3613 /* for start-rec */
3614 unit_bytes += sizeof(xlog_op_header_t);
3615
3616 /*
3617 * for LR headers - the space for data in an iclog is the size minus
3618 * the space used for the headers. If we use the iclog size, then we
3619 * undercalculate the number of headers required.
3620 *
3621 * Furthermore - the addition of op headers for split-recs might
3622 * increase the space required enough to require more log and op
3623 * headers, so take that into account too.
3624 *
3625 * IMPORTANT: This reservation makes the assumption that if this
3626 * transaction is the first in an iclog and hence has the LR headers
3627 * accounted to it, then the remaining space in the iclog is
3628 * exclusively for this transaction. i.e. if the transaction is larger
3629 * than the iclog, it will be the only thing in that iclog.
3630 * Fundamentally, this means we must pass the entire log vector to
3631 * xlog_write to guarantee this.
3632 */
3633 iclog_space = log->l_iclog_size - log->l_iclog_hsize;
3634 num_headers = howmany(unit_bytes, iclog_space);
3635
3636 /* for split-recs - ophdrs added when data split over LRs */
3637 unit_bytes += sizeof(xlog_op_header_t) * num_headers;
3638
3639 /* add extra header reservations if we overrun */
3640 while (!num_headers ||
3641 howmany(unit_bytes, iclog_space) > num_headers) {
3642 unit_bytes += sizeof(xlog_op_header_t);
3643 num_headers++;
3644 }
3645 unit_bytes += log->l_iclog_hsize * num_headers;
3646
3647 /* for commit-rec LR header - note: padding will subsume the ophdr */
3648 unit_bytes += log->l_iclog_hsize;
3649
3650 /* for roundoff padding for transaction data and one for commit record */
3651 if (xfs_sb_version_haslogv2(&mp->m_sb) && mp->m_sb.sb_logsunit > 1) {
3652 /* log su roundoff */
3653 unit_bytes += 2 * mp->m_sb.sb_logsunit;
3654 } else {
3655 /* BB roundoff */
3656 unit_bytes += 2 * BBSIZE;
3657 }
3658
3659 return unit_bytes;
3660}
3661
3662/*
3663 * Allocate and initialise a new log ticket.
3664 */
3665struct xlog_ticket *
3666xlog_ticket_alloc(
3667 struct xlog *log,
3668 int unit_bytes,
3669 int cnt,
3670 char client,
3671 bool permanent,
3672 xfs_km_flags_t alloc_flags)
3673{
3674 struct xlog_ticket *tic;
3675 int unit_res;
3676
3677 tic = kmem_zone_zalloc(xfs_log_ticket_zone, alloc_flags);
3678 if (!tic)
3679 return NULL;
3680
3681 unit_res = xfs_log_calc_unit_res(log->l_mp, unit_bytes);
3682
3683 atomic_set(&tic->t_ref, 1);
3684 tic->t_task = current;
3685 INIT_LIST_HEAD(&tic->t_queue);
3686 tic->t_unit_res = unit_res;
3687 tic->t_curr_res = unit_res;
3688 tic->t_cnt = cnt;
3689 tic->t_ocnt = cnt;
3690 tic->t_tid = prandom_u32();
3691 tic->t_clientid = client;
3692 tic->t_flags = XLOG_TIC_INITED;
3693 if (permanent)
3694 tic->t_flags |= XLOG_TIC_PERM_RESERV;
3695
3696 xlog_tic_reset_res(tic);
3697
3698 return tic;
3699}
3700
3701
3702/******************************************************************************
3703 *
3704 * Log debug routines
3705 *
3706 ******************************************************************************
3707 */
3708#if defined(DEBUG)
3709/*
3710 * Make sure that the destination ptr is within the valid data region of
3711 * one of the iclogs. This uses backup pointers stored in a different
3712 * part of the log in case we trash the log structure.
3713 */
3714STATIC void
3715xlog_verify_dest_ptr(
3716 struct xlog *log,
3717 void *ptr)
3718{
3719 int i;
3720 int good_ptr = 0;
3721
3722 for (i = 0; i < log->l_iclog_bufs; i++) {
3723 if (ptr >= log->l_iclog_bak[i] &&
3724 ptr <= log->l_iclog_bak[i] + log->l_iclog_size)
3725 good_ptr++;
3726 }
3727
3728 if (!good_ptr)
3729 xfs_emerg(log->l_mp, "%s: invalid ptr", __func__);
3730}
3731
3732/*
3733 * Check to make sure the grant write head didn't just over lap the tail. If
3734 * the cycles are the same, we can't be overlapping. Otherwise, make sure that
3735 * the cycles differ by exactly one and check the byte count.
3736 *
3737 * This check is run unlocked, so can give false positives. Rather than assert
3738 * on failures, use a warn-once flag and a panic tag to allow the admin to
3739 * determine if they want to panic the machine when such an error occurs. For
3740 * debug kernels this will have the same effect as using an assert but, unlinke
3741 * an assert, it can be turned off at runtime.
3742 */
3743STATIC void
3744xlog_verify_grant_tail(
3745 struct xlog *log)
3746{
3747 int tail_cycle, tail_blocks;
3748 int cycle, space;
3749
3750 xlog_crack_grant_head(&log->l_write_head.grant, &cycle, &space);
3751 xlog_crack_atomic_lsn(&log->l_tail_lsn, &tail_cycle, &tail_blocks);
3752 if (tail_cycle != cycle) {
3753 if (cycle - 1 != tail_cycle &&
3754 !(log->l_flags & XLOG_TAIL_WARN)) {
3755 xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES,
3756 "%s: cycle - 1 != tail_cycle", __func__);
3757 log->l_flags |= XLOG_TAIL_WARN;
3758 }
3759
3760 if (space > BBTOB(tail_blocks) &&
3761 !(log->l_flags & XLOG_TAIL_WARN)) {
3762 xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES,
3763 "%s: space > BBTOB(tail_blocks)", __func__);
3764 log->l_flags |= XLOG_TAIL_WARN;
3765 }
3766 }
3767}
3768
3769/* check if it will fit */
3770STATIC void
3771xlog_verify_tail_lsn(
3772 struct xlog *log,
3773 struct xlog_in_core *iclog,
3774 xfs_lsn_t tail_lsn)
3775{
3776 int blocks;
3777
3778 if (CYCLE_LSN(tail_lsn) == log->l_prev_cycle) {
3779 blocks =
3780 log->l_logBBsize - (log->l_prev_block - BLOCK_LSN(tail_lsn));
3781 if (blocks < BTOBB(iclog->ic_offset)+BTOBB(log->l_iclog_hsize))
3782 xfs_emerg(log->l_mp, "%s: ran out of log space", __func__);
3783 } else {
3784 ASSERT(CYCLE_LSN(tail_lsn)+1 == log->l_prev_cycle);
3785
3786 if (BLOCK_LSN(tail_lsn) == log->l_prev_block)
3787 xfs_emerg(log->l_mp, "%s: tail wrapped", __func__);
3788
3789 blocks = BLOCK_LSN(tail_lsn) - log->l_prev_block;
3790 if (blocks < BTOBB(iclog->ic_offset) + 1)
3791 xfs_emerg(log->l_mp, "%s: ran out of log space", __func__);
3792 }
3793} /* xlog_verify_tail_lsn */
3794
3795/*
3796 * Perform a number of checks on the iclog before writing to disk.
3797 *
3798 * 1. Make sure the iclogs are still circular
3799 * 2. Make sure we have a good magic number
3800 * 3. Make sure we don't have magic numbers in the data
3801 * 4. Check fields of each log operation header for:
3802 * A. Valid client identifier
3803 * B. tid ptr value falls in valid ptr space (user space code)
3804 * C. Length in log record header is correct according to the
3805 * individual operation headers within record.
3806 * 5. When a bwrite will occur within 5 blocks of the front of the physical
3807 * log, check the preceding blocks of the physical log to make sure all
3808 * the cycle numbers agree with the current cycle number.
3809 */
3810STATIC void
3811xlog_verify_iclog(
3812 struct xlog *log,
3813 struct xlog_in_core *iclog,
3814 int count,
3815 bool syncing)
3816{
3817 xlog_op_header_t *ophead;
3818 xlog_in_core_t *icptr;
3819 xlog_in_core_2_t *xhdr;
3820 void *base_ptr, *ptr, *p;
3821 ptrdiff_t field_offset;
3822 uint8_t clientid;
3823 int len, i, j, k, op_len;
3824 int idx;
3825
3826 /* check validity of iclog pointers */
3827 spin_lock(&log->l_icloglock);
3828 icptr = log->l_iclog;
3829 for (i = 0; i < log->l_iclog_bufs; i++, icptr = icptr->ic_next)
3830 ASSERT(icptr);
3831
3832 if (icptr != log->l_iclog)
3833 xfs_emerg(log->l_mp, "%s: corrupt iclog ring", __func__);
3834 spin_unlock(&log->l_icloglock);
3835
3836 /* check log magic numbers */
3837 if (iclog->ic_header.h_magicno != cpu_to_be32(XLOG_HEADER_MAGIC_NUM))
3838 xfs_emerg(log->l_mp, "%s: invalid magic num", __func__);
3839
3840 base_ptr = ptr = &iclog->ic_header;
3841 p = &iclog->ic_header;
3842 for (ptr += BBSIZE; ptr < base_ptr + count; ptr += BBSIZE) {
3843 if (*(__be32 *)ptr == cpu_to_be32(XLOG_HEADER_MAGIC_NUM))
3844 xfs_emerg(log->l_mp, "%s: unexpected magic num",
3845 __func__);
3846 }
3847
3848 /* check fields */
3849 len = be32_to_cpu(iclog->ic_header.h_num_logops);
3850 base_ptr = ptr = iclog->ic_datap;
3851 ophead = ptr;
3852 xhdr = iclog->ic_data;
3853 for (i = 0; i < len; i++) {
3854 ophead = ptr;
3855
3856 /* clientid is only 1 byte */
3857 p = &ophead->oh_clientid;
3858 field_offset = p - base_ptr;
3859 if (!syncing || (field_offset & 0x1ff)) {
3860 clientid = ophead->oh_clientid;
3861 } else {
3862 idx = BTOBBT((char *)&ophead->oh_clientid - iclog->ic_datap);
3863 if (idx >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE)) {
3864 j = idx / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3865 k = idx % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3866 clientid = xlog_get_client_id(
3867 xhdr[j].hic_xheader.xh_cycle_data[k]);
3868 } else {
3869 clientid = xlog_get_client_id(
3870 iclog->ic_header.h_cycle_data[idx]);
3871 }
3872 }
3873 if (clientid != XFS_TRANSACTION && clientid != XFS_LOG)
3874 xfs_warn(log->l_mp,
3875 "%s: invalid clientid %d op "PTR_FMT" offset 0x%lx",
3876 __func__, clientid, ophead,
3877 (unsigned long)field_offset);
3878
3879 /* check length */
3880 p = &ophead->oh_len;
3881 field_offset = p - base_ptr;
3882 if (!syncing || (field_offset & 0x1ff)) {
3883 op_len = be32_to_cpu(ophead->oh_len);
3884 } else {
3885 idx = BTOBBT((uintptr_t)&ophead->oh_len -
3886 (uintptr_t)iclog->ic_datap);
3887 if (idx >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE)) {
3888 j = idx / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3889 k = idx % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3890 op_len = be32_to_cpu(xhdr[j].hic_xheader.xh_cycle_data[k]);
3891 } else {
3892 op_len = be32_to_cpu(iclog->ic_header.h_cycle_data[idx]);
3893 }
3894 }
3895 ptr += sizeof(xlog_op_header_t) + op_len;
3896 }
3897} /* xlog_verify_iclog */
3898#endif
3899
3900/*
3901 * Mark all iclogs IOERROR. l_icloglock is held by the caller.
3902 */
3903STATIC int
3904xlog_state_ioerror(
3905 struct xlog *log)
3906{
3907 xlog_in_core_t *iclog, *ic;
3908
3909 iclog = log->l_iclog;
3910 if (! (iclog->ic_state & XLOG_STATE_IOERROR)) {
3911 /*
3912 * Mark all the incore logs IOERROR.
3913 * From now on, no log flushes will result.
3914 */
3915 ic = iclog;
3916 do {
3917 ic->ic_state = XLOG_STATE_IOERROR;
3918 ic = ic->ic_next;
3919 } while (ic != iclog);
3920 return 0;
3921 }
3922 /*
3923 * Return non-zero, if state transition has already happened.
3924 */
3925 return 1;
3926}
3927
3928/*
3929 * This is called from xfs_force_shutdown, when we're forcibly
3930 * shutting down the filesystem, typically because of an IO error.
3931 * Our main objectives here are to make sure that:
3932 * a. if !logerror, flush the logs to disk. Anything modified
3933 * after this is ignored.
3934 * b. the filesystem gets marked 'SHUTDOWN' for all interested
3935 * parties to find out, 'atomically'.
3936 * c. those who're sleeping on log reservations, pinned objects and
3937 * other resources get woken up, and be told the bad news.
3938 * d. nothing new gets queued up after (b) and (c) are done.
3939 *
3940 * Note: for the !logerror case we need to flush the regions held in memory out
3941 * to disk first. This needs to be done before the log is marked as shutdown,
3942 * otherwise the iclog writes will fail.
3943 */
3944int
3945xfs_log_force_umount(
3946 struct xfs_mount *mp,
3947 int logerror)
3948{
3949 struct xlog *log;
3950 int retval;
3951
3952 log = mp->m_log;
3953
3954 /*
3955 * If this happens during log recovery, don't worry about
3956 * locking; the log isn't open for business yet.
3957 */
3958 if (!log ||
3959 log->l_flags & XLOG_ACTIVE_RECOVERY) {
3960 mp->m_flags |= XFS_MOUNT_FS_SHUTDOWN;
3961 if (mp->m_sb_bp)
3962 mp->m_sb_bp->b_flags |= XBF_DONE;
3963 return 0;
3964 }
3965
3966 /*
3967 * Somebody could've already done the hard work for us.
3968 * No need to get locks for this.
3969 */
3970 if (logerror && log->l_iclog->ic_state & XLOG_STATE_IOERROR) {
3971 ASSERT(XLOG_FORCED_SHUTDOWN(log));
3972 return 1;
3973 }
3974
3975 /*
3976 * Flush all the completed transactions to disk before marking the log
3977 * being shut down. We need to do it in this order to ensure that
3978 * completed operations are safely on disk before we shut down, and that
3979 * we don't have to issue any buffer IO after the shutdown flags are set
3980 * to guarantee this.
3981 */
3982 if (!logerror)
3983 xfs_log_force(mp, XFS_LOG_SYNC);
3984
3985 /*
3986 * mark the filesystem and the as in a shutdown state and wake
3987 * everybody up to tell them the bad news.
3988 */
3989 spin_lock(&log->l_icloglock);
3990 mp->m_flags |= XFS_MOUNT_FS_SHUTDOWN;
3991 if (mp->m_sb_bp)
3992 mp->m_sb_bp->b_flags |= XBF_DONE;
3993
3994 /*
3995 * Mark the log and the iclogs with IO error flags to prevent any
3996 * further log IO from being issued or completed.
3997 */
3998 log->l_flags |= XLOG_IO_ERROR;
3999 retval = xlog_state_ioerror(log);
4000 spin_unlock(&log->l_icloglock);
4001
4002 /*
4003 * We don't want anybody waiting for log reservations after this. That
4004 * means we have to wake up everybody queued up on reserveq as well as
4005 * writeq. In addition, we make sure in xlog_{re}grant_log_space that
4006 * we don't enqueue anything once the SHUTDOWN flag is set, and this
4007 * action is protected by the grant locks.
4008 */
4009 xlog_grant_head_wake_all(&log->l_reserve_head);
4010 xlog_grant_head_wake_all(&log->l_write_head);
4011
4012 /*
4013 * Wake up everybody waiting on xfs_log_force. Wake the CIL push first
4014 * as if the log writes were completed. The abort handling in the log
4015 * item committed callback functions will do this again under lock to
4016 * avoid races.
4017 */
4018 wake_up_all(&log->l_cilp->xc_commit_wait);
4019 xlog_state_do_callback(log, XFS_LI_ABORTED, NULL);
4020
4021#ifdef XFSERRORDEBUG
4022 {
4023 xlog_in_core_t *iclog;
4024
4025 spin_lock(&log->l_icloglock);
4026 iclog = log->l_iclog;
4027 do {
4028 ASSERT(iclog->ic_callback == 0);
4029 iclog = iclog->ic_next;
4030 } while (iclog != log->l_iclog);
4031 spin_unlock(&log->l_icloglock);
4032 }
4033#endif
4034 /* return non-zero if log IOERROR transition had already happened */
4035 return retval;
4036}
4037
4038STATIC int
4039xlog_iclogs_empty(
4040 struct xlog *log)
4041{
4042 xlog_in_core_t *iclog;
4043
4044 iclog = log->l_iclog;
4045 do {
4046 /* endianness does not matter here, zero is zero in
4047 * any language.
4048 */
4049 if (iclog->ic_header.h_num_logops)
4050 return 0;
4051 iclog = iclog->ic_next;
4052 } while (iclog != log->l_iclog);
4053 return 1;
4054}
4055
4056/*
4057 * Verify that an LSN stamped into a piece of metadata is valid. This is
4058 * intended for use in read verifiers on v5 superblocks.
4059 */
4060bool
4061xfs_log_check_lsn(
4062 struct xfs_mount *mp,
4063 xfs_lsn_t lsn)
4064{
4065 struct xlog *log = mp->m_log;
4066 bool valid;
4067
4068 /*
4069 * norecovery mode skips mount-time log processing and unconditionally
4070 * resets the in-core LSN. We can't validate in this mode, but
4071 * modifications are not allowed anyways so just return true.
4072 */
4073 if (mp->m_flags & XFS_MOUNT_NORECOVERY)
4074 return true;
4075
4076 /*
4077 * Some metadata LSNs are initialized to NULL (e.g., the agfl). This is
4078 * handled by recovery and thus safe to ignore here.
4079 */
4080 if (lsn == NULLCOMMITLSN)
4081 return true;
4082
4083 valid = xlog_valid_lsn(mp->m_log, lsn);
4084
4085 /* warn the user about what's gone wrong before verifier failure */
4086 if (!valid) {
4087 spin_lock(&log->l_icloglock);
4088 xfs_warn(mp,
4089"Corruption warning: Metadata has LSN (%d:%d) ahead of current LSN (%d:%d). "
4090"Please unmount and run xfs_repair (>= v4.3) to resolve.",
4091 CYCLE_LSN(lsn), BLOCK_LSN(lsn),
4092 log->l_curr_cycle, log->l_curr_block);
4093 spin_unlock(&log->l_icloglock);
4094 }
4095
4096 return valid;
4097}
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 void
34xlog_dealloc_log(
35 struct xlog *log);
36
37/* local state machine functions */
38STATIC void xlog_state_done_syncing(
39 struct xlog_in_core *iclog);
40STATIC void xlog_state_do_callback(
41 struct xlog *log);
42STATIC int
43xlog_state_get_iclog_space(
44 struct xlog *log,
45 int len,
46 struct xlog_in_core **iclog,
47 struct xlog_ticket *ticket,
48 int *logoffsetp);
49STATIC void
50xlog_sync(
51 struct xlog *log,
52 struct xlog_in_core *iclog,
53 struct xlog_ticket *ticket);
54#if defined(DEBUG)
55STATIC void
56xlog_verify_iclog(
57 struct xlog *log,
58 struct xlog_in_core *iclog,
59 int count);
60STATIC void
61xlog_verify_tail_lsn(
62 struct xlog *log,
63 struct xlog_in_core *iclog);
64#else
65#define xlog_verify_iclog(a,b,c)
66#define xlog_verify_tail_lsn(a,b)
67#endif
68
69STATIC int
70xlog_iclogs_empty(
71 struct xlog *log);
72
73static int
74xfs_log_cover(struct xfs_mount *);
75
76/*
77 * We need to make sure the buffer pointer returned is naturally aligned for the
78 * biggest basic data type we put into it. We have already accounted for this
79 * padding when sizing the buffer.
80 *
81 * However, this padding does not get written into the log, and hence we have to
82 * track the space used by the log vectors separately to prevent log space hangs
83 * due to inaccurate accounting (i.e. a leak) of the used log space through the
84 * CIL context ticket.
85 *
86 * We also add space for the xlog_op_header that describes this region in the
87 * log. This prepends the data region we return to the caller to copy their data
88 * into, so do all the static initialisation of the ophdr now. Because the ophdr
89 * is not 8 byte aligned, we have to be careful to ensure that we align the
90 * start of the buffer such that the region we return to the call is 8 byte
91 * aligned and packed against the tail of the ophdr.
92 */
93void *
94xlog_prepare_iovec(
95 struct xfs_log_vec *lv,
96 struct xfs_log_iovec **vecp,
97 uint type)
98{
99 struct xfs_log_iovec *vec = *vecp;
100 struct xlog_op_header *oph;
101 uint32_t len;
102 void *buf;
103
104 if (vec) {
105 ASSERT(vec - lv->lv_iovecp < lv->lv_niovecs);
106 vec++;
107 } else {
108 vec = &lv->lv_iovecp[0];
109 }
110
111 len = lv->lv_buf_len + sizeof(struct xlog_op_header);
112 if (!IS_ALIGNED(len, sizeof(uint64_t))) {
113 lv->lv_buf_len = round_up(len, sizeof(uint64_t)) -
114 sizeof(struct xlog_op_header);
115 }
116
117 vec->i_type = type;
118 vec->i_addr = lv->lv_buf + lv->lv_buf_len;
119
120 oph = vec->i_addr;
121 oph->oh_clientid = XFS_TRANSACTION;
122 oph->oh_res2 = 0;
123 oph->oh_flags = 0;
124
125 buf = vec->i_addr + sizeof(struct xlog_op_header);
126 ASSERT(IS_ALIGNED((unsigned long)buf, sizeof(uint64_t)));
127
128 *vecp = vec;
129 return buf;
130}
131
132static inline void
133xlog_grant_sub_space(
134 struct xlog_grant_head *head,
135 int64_t bytes)
136{
137 atomic64_sub(bytes, &head->grant);
138}
139
140static inline void
141xlog_grant_add_space(
142 struct xlog_grant_head *head,
143 int64_t bytes)
144{
145 atomic64_add(bytes, &head->grant);
146}
147
148static void
149xlog_grant_head_init(
150 struct xlog_grant_head *head)
151{
152 atomic64_set(&head->grant, 0);
153 INIT_LIST_HEAD(&head->waiters);
154 spin_lock_init(&head->lock);
155}
156
157void
158xlog_grant_return_space(
159 struct xlog *log,
160 xfs_lsn_t old_head,
161 xfs_lsn_t new_head)
162{
163 int64_t diff = xlog_lsn_sub(log, new_head, old_head);
164
165 xlog_grant_sub_space(&log->l_reserve_head, diff);
166 xlog_grant_sub_space(&log->l_write_head, diff);
167}
168
169/*
170 * Return the space in the log between the tail and the head. In the case where
171 * we have overrun available reservation space, return 0. The memory barrier
172 * pairs with the smp_wmb() in xlog_cil_ail_insert() to ensure that grant head
173 * vs tail space updates are seen in the correct order and hence avoid
174 * transients as space is transferred from the grant heads to the AIL on commit
175 * completion.
176 */
177static uint64_t
178xlog_grant_space_left(
179 struct xlog *log,
180 struct xlog_grant_head *head)
181{
182 int64_t free_bytes;
183
184 smp_rmb(); /* paired with smp_wmb in xlog_cil_ail_insert() */
185 free_bytes = log->l_logsize - READ_ONCE(log->l_tail_space) -
186 atomic64_read(&head->grant);
187 if (free_bytes > 0)
188 return free_bytes;
189 return 0;
190}
191
192STATIC void
193xlog_grant_head_wake_all(
194 struct xlog_grant_head *head)
195{
196 struct xlog_ticket *tic;
197
198 spin_lock(&head->lock);
199 list_for_each_entry(tic, &head->waiters, t_queue)
200 wake_up_process(tic->t_task);
201 spin_unlock(&head->lock);
202}
203
204static inline int
205xlog_ticket_reservation(
206 struct xlog *log,
207 struct xlog_grant_head *head,
208 struct xlog_ticket *tic)
209{
210 if (head == &log->l_write_head) {
211 ASSERT(tic->t_flags & XLOG_TIC_PERM_RESERV);
212 return tic->t_unit_res;
213 }
214
215 if (tic->t_flags & XLOG_TIC_PERM_RESERV)
216 return tic->t_unit_res * tic->t_cnt;
217
218 return tic->t_unit_res;
219}
220
221STATIC bool
222xlog_grant_head_wake(
223 struct xlog *log,
224 struct xlog_grant_head *head,
225 int *free_bytes)
226{
227 struct xlog_ticket *tic;
228 int need_bytes;
229
230 list_for_each_entry(tic, &head->waiters, t_queue) {
231 need_bytes = xlog_ticket_reservation(log, head, tic);
232 if (*free_bytes < need_bytes)
233 return false;
234
235 *free_bytes -= need_bytes;
236 trace_xfs_log_grant_wake_up(log, tic);
237 wake_up_process(tic->t_task);
238 }
239
240 return true;
241}
242
243STATIC int
244xlog_grant_head_wait(
245 struct xlog *log,
246 struct xlog_grant_head *head,
247 struct xlog_ticket *tic,
248 int need_bytes) __releases(&head->lock)
249 __acquires(&head->lock)
250{
251 list_add_tail(&tic->t_queue, &head->waiters);
252
253 do {
254 if (xlog_is_shutdown(log))
255 goto shutdown;
256
257 __set_current_state(TASK_UNINTERRUPTIBLE);
258 spin_unlock(&head->lock);
259
260 XFS_STATS_INC(log->l_mp, xs_sleep_logspace);
261
262 /* Push on the AIL to free up all the log space. */
263 xfs_ail_push_all(log->l_ailp);
264
265 trace_xfs_log_grant_sleep(log, tic);
266 schedule();
267 trace_xfs_log_grant_wake(log, tic);
268
269 spin_lock(&head->lock);
270 if (xlog_is_shutdown(log))
271 goto shutdown;
272 } while (xlog_grant_space_left(log, head) < need_bytes);
273
274 list_del_init(&tic->t_queue);
275 return 0;
276shutdown:
277 list_del_init(&tic->t_queue);
278 return -EIO;
279}
280
281/*
282 * Atomically get the log space required for a log ticket.
283 *
284 * Once a ticket gets put onto head->waiters, it will only return after the
285 * needed reservation is satisfied.
286 *
287 * This function is structured so that it has a lock free fast path. This is
288 * necessary because every new transaction reservation will come through this
289 * path. Hence any lock will be globally hot if we take it unconditionally on
290 * every pass.
291 *
292 * As tickets are only ever moved on and off head->waiters under head->lock, we
293 * only need to take that lock if we are going to add the ticket to the queue
294 * and sleep. We can avoid taking the lock if the ticket was never added to
295 * head->waiters because the t_queue list head will be empty and we hold the
296 * only reference to it so it can safely be checked unlocked.
297 */
298STATIC int
299xlog_grant_head_check(
300 struct xlog *log,
301 struct xlog_grant_head *head,
302 struct xlog_ticket *tic,
303 int *need_bytes)
304{
305 int free_bytes;
306 int error = 0;
307
308 ASSERT(!xlog_in_recovery(log));
309
310 /*
311 * If there are other waiters on the queue then give them a chance at
312 * logspace before us. Wake up the first waiters, if we do not wake
313 * up all the waiters then go to sleep waiting for more free space,
314 * otherwise try to get some space for this transaction.
315 */
316 *need_bytes = xlog_ticket_reservation(log, head, tic);
317 free_bytes = xlog_grant_space_left(log, head);
318 if (!list_empty_careful(&head->waiters)) {
319 spin_lock(&head->lock);
320 if (!xlog_grant_head_wake(log, head, &free_bytes) ||
321 free_bytes < *need_bytes) {
322 error = xlog_grant_head_wait(log, head, tic,
323 *need_bytes);
324 }
325 spin_unlock(&head->lock);
326 } else if (free_bytes < *need_bytes) {
327 spin_lock(&head->lock);
328 error = xlog_grant_head_wait(log, head, tic, *need_bytes);
329 spin_unlock(&head->lock);
330 }
331
332 return error;
333}
334
335bool
336xfs_log_writable(
337 struct xfs_mount *mp)
338{
339 /*
340 * Do not write to the log on norecovery mounts, if the data or log
341 * devices are read-only, or if the filesystem is shutdown. Read-only
342 * mounts allow internal writes for log recovery and unmount purposes,
343 * so don't restrict that case.
344 */
345 if (xfs_has_norecovery(mp))
346 return false;
347 if (xfs_readonly_buftarg(mp->m_ddev_targp))
348 return false;
349 if (xfs_readonly_buftarg(mp->m_log->l_targ))
350 return false;
351 if (xlog_is_shutdown(mp->m_log))
352 return false;
353 return true;
354}
355
356/*
357 * Replenish the byte reservation required by moving the grant write head.
358 */
359int
360xfs_log_regrant(
361 struct xfs_mount *mp,
362 struct xlog_ticket *tic)
363{
364 struct xlog *log = mp->m_log;
365 int need_bytes;
366 int error = 0;
367
368 if (xlog_is_shutdown(log))
369 return -EIO;
370
371 XFS_STATS_INC(mp, xs_try_logspace);
372
373 /*
374 * This is a new transaction on the ticket, so we need to change the
375 * transaction ID so that the next transaction has a different TID in
376 * the log. Just add one to the existing tid so that we can see chains
377 * of rolling transactions in the log easily.
378 */
379 tic->t_tid++;
380 tic->t_curr_res = tic->t_unit_res;
381 if (tic->t_cnt > 0)
382 return 0;
383
384 trace_xfs_log_regrant(log, tic);
385
386 error = xlog_grant_head_check(log, &log->l_write_head, tic,
387 &need_bytes);
388 if (error)
389 goto out_error;
390
391 xlog_grant_add_space(&log->l_write_head, need_bytes);
392 trace_xfs_log_regrant_exit(log, tic);
393 return 0;
394
395out_error:
396 /*
397 * If we are failing, make sure the ticket doesn't have any current
398 * reservations. We don't want to add this back when the ticket/
399 * transaction gets cancelled.
400 */
401 tic->t_curr_res = 0;
402 tic->t_cnt = 0; /* ungrant will give back unit_res * t_cnt. */
403 return error;
404}
405
406/*
407 * Reserve log space and return a ticket corresponding to the reservation.
408 *
409 * Each reservation is going to reserve extra space for a log record header.
410 * When writes happen to the on-disk log, we don't subtract the length of the
411 * log record header from any reservation. By wasting space in each
412 * reservation, we prevent over allocation problems.
413 */
414int
415xfs_log_reserve(
416 struct xfs_mount *mp,
417 int unit_bytes,
418 int cnt,
419 struct xlog_ticket **ticp,
420 bool permanent)
421{
422 struct xlog *log = mp->m_log;
423 struct xlog_ticket *tic;
424 int need_bytes;
425 int error = 0;
426
427 if (xlog_is_shutdown(log))
428 return -EIO;
429
430 XFS_STATS_INC(mp, xs_try_logspace);
431
432 ASSERT(*ticp == NULL);
433 tic = xlog_ticket_alloc(log, unit_bytes, cnt, permanent);
434 *ticp = tic;
435 trace_xfs_log_reserve(log, tic);
436 error = xlog_grant_head_check(log, &log->l_reserve_head, tic,
437 &need_bytes);
438 if (error)
439 goto out_error;
440
441 xlog_grant_add_space(&log->l_reserve_head, need_bytes);
442 xlog_grant_add_space(&log->l_write_head, need_bytes);
443 trace_xfs_log_reserve_exit(log, tic);
444 return 0;
445
446out_error:
447 /*
448 * If we are failing, make sure the ticket doesn't have any current
449 * reservations. We don't want to add this back when the ticket/
450 * transaction gets cancelled.
451 */
452 tic->t_curr_res = 0;
453 tic->t_cnt = 0; /* ungrant will give back unit_res * t_cnt. */
454 return error;
455}
456
457/*
458 * Run all the pending iclog callbacks and wake log force waiters and iclog
459 * space waiters so they can process the newly set shutdown state. We really
460 * don't care what order we process callbacks here because the log is shut down
461 * and so state cannot change on disk anymore. However, we cannot wake waiters
462 * until the callbacks have been processed because we may be in unmount and
463 * we must ensure that all AIL operations the callbacks perform have completed
464 * before we tear down the AIL.
465 *
466 * We avoid processing actively referenced iclogs so that we don't run callbacks
467 * while the iclog owner might still be preparing the iclog for IO submssion.
468 * These will be caught by xlog_state_iclog_release() and call this function
469 * again to process any callbacks that may have been added to that iclog.
470 */
471static void
472xlog_state_shutdown_callbacks(
473 struct xlog *log)
474{
475 struct xlog_in_core *iclog;
476 LIST_HEAD(cb_list);
477
478 iclog = log->l_iclog;
479 do {
480 if (atomic_read(&iclog->ic_refcnt)) {
481 /* Reference holder will re-run iclog callbacks. */
482 continue;
483 }
484 list_splice_init(&iclog->ic_callbacks, &cb_list);
485 spin_unlock(&log->l_icloglock);
486
487 xlog_cil_process_committed(&cb_list);
488
489 spin_lock(&log->l_icloglock);
490 wake_up_all(&iclog->ic_write_wait);
491 wake_up_all(&iclog->ic_force_wait);
492 } while ((iclog = iclog->ic_next) != log->l_iclog);
493
494 wake_up_all(&log->l_flush_wait);
495}
496
497/*
498 * Flush iclog to disk if this is the last reference to the given iclog and the
499 * it is in the WANT_SYNC state.
500 *
501 * If XLOG_ICL_NEED_FUA is already set on the iclog, we need to ensure that the
502 * log tail is updated correctly. NEED_FUA indicates that the iclog will be
503 * written to stable storage, and implies that a commit record is contained
504 * within the iclog. We need to ensure that the log tail does not move beyond
505 * the tail that the first commit record in the iclog ordered against, otherwise
506 * correct recovery of that checkpoint becomes dependent on future operations
507 * performed on this iclog.
508 *
509 * Hence if NEED_FUA is set and the current iclog tail lsn is empty, write the
510 * current tail into iclog. Once the iclog tail is set, future operations must
511 * not modify it, otherwise they potentially violate ordering constraints for
512 * the checkpoint commit that wrote the initial tail lsn value. The tail lsn in
513 * the iclog will get zeroed on activation of the iclog after sync, so we
514 * always capture the tail lsn on the iclog on the first NEED_FUA release
515 * regardless of the number of active reference counts on this iclog.
516 */
517int
518xlog_state_release_iclog(
519 struct xlog *log,
520 struct xlog_in_core *iclog,
521 struct xlog_ticket *ticket)
522{
523 bool last_ref;
524
525 lockdep_assert_held(&log->l_icloglock);
526
527 trace_xlog_iclog_release(iclog, _RET_IP_);
528 /*
529 * Grabbing the current log tail needs to be atomic w.r.t. the writing
530 * of the tail LSN into the iclog so we guarantee that the log tail does
531 * not move between the first time we know that the iclog needs to be
532 * made stable and when we eventually submit it.
533 */
534 if ((iclog->ic_state == XLOG_STATE_WANT_SYNC ||
535 (iclog->ic_flags & XLOG_ICL_NEED_FUA)) &&
536 !iclog->ic_header.h_tail_lsn) {
537 iclog->ic_header.h_tail_lsn =
538 cpu_to_be64(atomic64_read(&log->l_tail_lsn));
539 }
540
541 last_ref = atomic_dec_and_test(&iclog->ic_refcnt);
542
543 if (xlog_is_shutdown(log)) {
544 /*
545 * If there are no more references to this iclog, process the
546 * pending iclog callbacks that were waiting on the release of
547 * this iclog.
548 */
549 if (last_ref)
550 xlog_state_shutdown_callbacks(log);
551 return -EIO;
552 }
553
554 if (!last_ref)
555 return 0;
556
557 if (iclog->ic_state != XLOG_STATE_WANT_SYNC) {
558 ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE);
559 return 0;
560 }
561
562 iclog->ic_state = XLOG_STATE_SYNCING;
563 xlog_verify_tail_lsn(log, iclog);
564 trace_xlog_iclog_syncing(iclog, _RET_IP_);
565
566 spin_unlock(&log->l_icloglock);
567 xlog_sync(log, iclog, ticket);
568 spin_lock(&log->l_icloglock);
569 return 0;
570}
571
572/*
573 * Mount a log filesystem
574 *
575 * mp - ubiquitous xfs mount point structure
576 * log_target - buftarg of on-disk log device
577 * blk_offset - Start block # where block size is 512 bytes (BBSIZE)
578 * num_bblocks - Number of BBSIZE blocks in on-disk log
579 *
580 * Return error or zero.
581 */
582int
583xfs_log_mount(
584 xfs_mount_t *mp,
585 struct xfs_buftarg *log_target,
586 xfs_daddr_t blk_offset,
587 int num_bblks)
588{
589 struct xlog *log;
590 int error = 0;
591 int min_logfsbs;
592
593 if (!xfs_has_norecovery(mp)) {
594 xfs_notice(mp, "Mounting V%d Filesystem %pU",
595 XFS_SB_VERSION_NUM(&mp->m_sb),
596 &mp->m_sb.sb_uuid);
597 } else {
598 xfs_notice(mp,
599"Mounting V%d filesystem %pU in no-recovery mode. Filesystem will be inconsistent.",
600 XFS_SB_VERSION_NUM(&mp->m_sb),
601 &mp->m_sb.sb_uuid);
602 ASSERT(xfs_is_readonly(mp));
603 }
604
605 log = xlog_alloc_log(mp, log_target, blk_offset, num_bblks);
606 if (IS_ERR(log)) {
607 error = PTR_ERR(log);
608 goto out;
609 }
610 mp->m_log = log;
611
612 /*
613 * Now that we have set up the log and it's internal geometry
614 * parameters, we can validate the given log space and drop a critical
615 * message via syslog if the log size is too small. A log that is too
616 * small can lead to unexpected situations in transaction log space
617 * reservation stage. The superblock verifier has already validated all
618 * the other log geometry constraints, so we don't have to check those
619 * here.
620 *
621 * Note: For v4 filesystems, we can't just reject the mount if the
622 * validation fails. This would mean that people would have to
623 * downgrade their kernel just to remedy the situation as there is no
624 * way to grow the log (short of black magic surgery with xfs_db).
625 *
626 * We can, however, reject mounts for V5 format filesystems, as the
627 * mkfs binary being used to make the filesystem should never create a
628 * filesystem with a log that is too small.
629 */
630 min_logfsbs = xfs_log_calc_minimum_size(mp);
631 if (mp->m_sb.sb_logblocks < min_logfsbs) {
632 xfs_warn(mp,
633 "Log size %d blocks too small, minimum size is %d blocks",
634 mp->m_sb.sb_logblocks, min_logfsbs);
635
636 /*
637 * Log check errors are always fatal on v5; or whenever bad
638 * metadata leads to a crash.
639 */
640 if (xfs_has_crc(mp)) {
641 xfs_crit(mp, "AAIEEE! Log failed size checks. Abort!");
642 ASSERT(0);
643 error = -EINVAL;
644 goto out_free_log;
645 }
646 xfs_crit(mp, "Log size out of supported range.");
647 xfs_crit(mp,
648"Continuing onwards, but if log hangs are experienced then please report this message in the bug report.");
649 }
650
651 /*
652 * Initialize the AIL now we have a log.
653 */
654 error = xfs_trans_ail_init(mp);
655 if (error) {
656 xfs_warn(mp, "AIL initialisation failed: error %d", error);
657 goto out_free_log;
658 }
659 log->l_ailp = mp->m_ail;
660
661 /*
662 * skip log recovery on a norecovery mount. pretend it all
663 * just worked.
664 */
665 if (!xfs_has_norecovery(mp)) {
666 error = xlog_recover(log);
667 if (error) {
668 xfs_warn(mp, "log mount/recovery failed: error %d",
669 error);
670 xlog_recover_cancel(log);
671 goto out_destroy_ail;
672 }
673 }
674
675 error = xfs_sysfs_init(&log->l_kobj, &xfs_log_ktype, &mp->m_kobj,
676 "log");
677 if (error)
678 goto out_destroy_ail;
679
680 /* Normal transactions can now occur */
681 clear_bit(XLOG_ACTIVE_RECOVERY, &log->l_opstate);
682
683 /*
684 * Now the log has been fully initialised and we know were our
685 * space grant counters are, we can initialise the permanent ticket
686 * needed for delayed logging to work.
687 */
688 xlog_cil_init_post_recovery(log);
689
690 return 0;
691
692out_destroy_ail:
693 xfs_trans_ail_destroy(mp);
694out_free_log:
695 xlog_dealloc_log(log);
696out:
697 return error;
698}
699
700/*
701 * Finish the recovery of the file system. This is separate from the
702 * xfs_log_mount() call, because it depends on the code in xfs_mountfs() to read
703 * in the root and real-time bitmap inodes between calling xfs_log_mount() and
704 * here.
705 *
706 * If we finish recovery successfully, start the background log work. If we are
707 * not doing recovery, then we have a RO filesystem and we don't need to start
708 * it.
709 */
710int
711xfs_log_mount_finish(
712 struct xfs_mount *mp)
713{
714 struct xlog *log = mp->m_log;
715 int error = 0;
716
717 if (xfs_has_norecovery(mp)) {
718 ASSERT(xfs_is_readonly(mp));
719 return 0;
720 }
721
722 /*
723 * During the second phase of log recovery, we need iget and
724 * iput to behave like they do for an active filesystem.
725 * xfs_fs_drop_inode needs to be able to prevent the deletion
726 * of inodes before we're done replaying log items on those
727 * inodes. Turn it off immediately after recovery finishes
728 * so that we don't leak the quota inodes if subsequent mount
729 * activities fail.
730 *
731 * We let all inodes involved in redo item processing end up on
732 * the LRU instead of being evicted immediately so that if we do
733 * something to an unlinked inode, the irele won't cause
734 * premature truncation and freeing of the inode, which results
735 * in log recovery failure. We have to evict the unreferenced
736 * lru inodes after clearing SB_ACTIVE because we don't
737 * otherwise clean up the lru if there's a subsequent failure in
738 * xfs_mountfs, which leads to us leaking the inodes if nothing
739 * else (e.g. quotacheck) references the inodes before the
740 * mount failure occurs.
741 */
742 mp->m_super->s_flags |= SB_ACTIVE;
743 xfs_log_work_queue(mp);
744 if (xlog_recovery_needed(log))
745 error = xlog_recover_finish(log);
746 mp->m_super->s_flags &= ~SB_ACTIVE;
747 evict_inodes(mp->m_super);
748
749 /*
750 * Drain the buffer LRU after log recovery. This is required for v4
751 * filesystems to avoid leaving around buffers with NULL verifier ops,
752 * but we do it unconditionally to make sure we're always in a clean
753 * cache state after mount.
754 *
755 * Don't push in the error case because the AIL may have pending intents
756 * that aren't removed until recovery is cancelled.
757 */
758 if (xlog_recovery_needed(log)) {
759 if (!error) {
760 xfs_log_force(mp, XFS_LOG_SYNC);
761 xfs_ail_push_all_sync(mp->m_ail);
762 }
763 xfs_notice(mp, "Ending recovery (logdev: %s)",
764 mp->m_logname ? mp->m_logname : "internal");
765 } else {
766 xfs_info(mp, "Ending clean mount");
767 }
768 xfs_buftarg_drain(mp->m_ddev_targp);
769
770 clear_bit(XLOG_RECOVERY_NEEDED, &log->l_opstate);
771
772 /* Make sure the log is dead if we're returning failure. */
773 ASSERT(!error || xlog_is_shutdown(log));
774
775 return error;
776}
777
778/*
779 * The mount has failed. Cancel the recovery if it hasn't completed and destroy
780 * the log.
781 */
782void
783xfs_log_mount_cancel(
784 struct xfs_mount *mp)
785{
786 xlog_recover_cancel(mp->m_log);
787 xfs_log_unmount(mp);
788}
789
790/*
791 * Flush out the iclog to disk ensuring that device caches are flushed and
792 * the iclog hits stable storage before any completion waiters are woken.
793 */
794static inline int
795xlog_force_iclog(
796 struct xlog_in_core *iclog)
797{
798 atomic_inc(&iclog->ic_refcnt);
799 iclog->ic_flags |= XLOG_ICL_NEED_FLUSH | XLOG_ICL_NEED_FUA;
800 if (iclog->ic_state == XLOG_STATE_ACTIVE)
801 xlog_state_switch_iclogs(iclog->ic_log, iclog, 0);
802 return xlog_state_release_iclog(iclog->ic_log, iclog, NULL);
803}
804
805/*
806 * Cycle all the iclogbuf locks to make sure all log IO completion
807 * is done before we tear down these buffers.
808 */
809static void
810xlog_wait_iclog_completion(struct xlog *log)
811{
812 int i;
813 struct xlog_in_core *iclog = log->l_iclog;
814
815 for (i = 0; i < log->l_iclog_bufs; i++) {
816 down(&iclog->ic_sema);
817 up(&iclog->ic_sema);
818 iclog = iclog->ic_next;
819 }
820}
821
822/*
823 * Wait for the iclog and all prior iclogs to be written disk as required by the
824 * log force state machine. Waiting on ic_force_wait ensures iclog completions
825 * have been ordered and callbacks run before we are woken here, hence
826 * guaranteeing that all the iclogs up to this one are on stable storage.
827 */
828int
829xlog_wait_on_iclog(
830 struct xlog_in_core *iclog)
831 __releases(iclog->ic_log->l_icloglock)
832{
833 struct xlog *log = iclog->ic_log;
834
835 trace_xlog_iclog_wait_on(iclog, _RET_IP_);
836 if (!xlog_is_shutdown(log) &&
837 iclog->ic_state != XLOG_STATE_ACTIVE &&
838 iclog->ic_state != XLOG_STATE_DIRTY) {
839 XFS_STATS_INC(log->l_mp, xs_log_force_sleep);
840 xlog_wait(&iclog->ic_force_wait, &log->l_icloglock);
841 } else {
842 spin_unlock(&log->l_icloglock);
843 }
844
845 if (xlog_is_shutdown(log))
846 return -EIO;
847 return 0;
848}
849
850/*
851 * Write out an unmount record using the ticket provided. We have to account for
852 * the data space used in the unmount ticket as this write is not done from a
853 * transaction context that has already done the accounting for us.
854 */
855static int
856xlog_write_unmount_record(
857 struct xlog *log,
858 struct xlog_ticket *ticket)
859{
860 struct {
861 struct xlog_op_header ophdr;
862 struct xfs_unmount_log_format ulf;
863 } unmount_rec = {
864 .ophdr = {
865 .oh_clientid = XFS_LOG,
866 .oh_tid = cpu_to_be32(ticket->t_tid),
867 .oh_flags = XLOG_UNMOUNT_TRANS,
868 },
869 .ulf = {
870 .magic = XLOG_UNMOUNT_TYPE,
871 },
872 };
873 struct xfs_log_iovec reg = {
874 .i_addr = &unmount_rec,
875 .i_len = sizeof(unmount_rec),
876 .i_type = XLOG_REG_TYPE_UNMOUNT,
877 };
878 struct xfs_log_vec vec = {
879 .lv_niovecs = 1,
880 .lv_iovecp = ®,
881 };
882 LIST_HEAD(lv_chain);
883 list_add(&vec.lv_list, &lv_chain);
884
885 BUILD_BUG_ON((sizeof(struct xlog_op_header) +
886 sizeof(struct xfs_unmount_log_format)) !=
887 sizeof(unmount_rec));
888
889 /* account for space used by record data */
890 ticket->t_curr_res -= sizeof(unmount_rec);
891
892 return xlog_write(log, NULL, &lv_chain, ticket, reg.i_len);
893}
894
895/*
896 * Mark the filesystem clean by writing an unmount record to the head of the
897 * log.
898 */
899static void
900xlog_unmount_write(
901 struct xlog *log)
902{
903 struct xfs_mount *mp = log->l_mp;
904 struct xlog_in_core *iclog;
905 struct xlog_ticket *tic = NULL;
906 int error;
907
908 error = xfs_log_reserve(mp, 600, 1, &tic, 0);
909 if (error)
910 goto out_err;
911
912 error = xlog_write_unmount_record(log, tic);
913 /*
914 * At this point, we're umounting anyway, so there's no point in
915 * transitioning log state to shutdown. Just continue...
916 */
917out_err:
918 if (error)
919 xfs_alert(mp, "%s: unmount record failed", __func__);
920
921 spin_lock(&log->l_icloglock);
922 iclog = log->l_iclog;
923 error = xlog_force_iclog(iclog);
924 xlog_wait_on_iclog(iclog);
925
926 if (tic) {
927 trace_xfs_log_umount_write(log, tic);
928 xfs_log_ticket_ungrant(log, tic);
929 }
930}
931
932static void
933xfs_log_unmount_verify_iclog(
934 struct xlog *log)
935{
936 struct xlog_in_core *iclog = log->l_iclog;
937
938 do {
939 ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE);
940 ASSERT(iclog->ic_offset == 0);
941 } while ((iclog = iclog->ic_next) != log->l_iclog);
942}
943
944/*
945 * Unmount record used to have a string "Unmount filesystem--" in the
946 * data section where the "Un" was really a magic number (XLOG_UNMOUNT_TYPE).
947 * We just write the magic number now since that particular field isn't
948 * currently architecture converted and "Unmount" is a bit foo.
949 * As far as I know, there weren't any dependencies on the old behaviour.
950 */
951static void
952xfs_log_unmount_write(
953 struct xfs_mount *mp)
954{
955 struct xlog *log = mp->m_log;
956
957 if (!xfs_log_writable(mp))
958 return;
959
960 xfs_log_force(mp, XFS_LOG_SYNC);
961
962 if (xlog_is_shutdown(log))
963 return;
964
965 /*
966 * If we think the summary counters are bad, avoid writing the unmount
967 * record to force log recovery at next mount, after which the summary
968 * counters will be recalculated. Refer to xlog_check_unmount_rec for
969 * more details.
970 */
971 if (XFS_TEST_ERROR(xfs_fs_has_sickness(mp, XFS_SICK_FS_COUNTERS), mp,
972 XFS_ERRTAG_FORCE_SUMMARY_RECALC)) {
973 xfs_alert(mp, "%s: will fix summary counters at next mount",
974 __func__);
975 return;
976 }
977
978 xfs_log_unmount_verify_iclog(log);
979 xlog_unmount_write(log);
980}
981
982/*
983 * Empty the log for unmount/freeze.
984 *
985 * To do this, we first need to shut down the background log work so it is not
986 * trying to cover the log as we clean up. We then need to unpin all objects in
987 * the log so we can then flush them out. Once they have completed their IO and
988 * run the callbacks removing themselves from the AIL, we can cover the log.
989 */
990int
991xfs_log_quiesce(
992 struct xfs_mount *mp)
993{
994 /*
995 * Clear log incompat features since we're quiescing the log. Report
996 * failures, though it's not fatal to have a higher log feature
997 * protection level than the log contents actually require.
998 */
999 if (xfs_clear_incompat_log_features(mp)) {
1000 int error;
1001
1002 error = xfs_sync_sb(mp, false);
1003 if (error)
1004 xfs_warn(mp,
1005 "Failed to clear log incompat features on quiesce");
1006 }
1007
1008 cancel_delayed_work_sync(&mp->m_log->l_work);
1009 xfs_log_force(mp, XFS_LOG_SYNC);
1010
1011 /*
1012 * The superblock buffer is uncached and while xfs_ail_push_all_sync()
1013 * will push it, xfs_buftarg_wait() will not wait for it. Further,
1014 * xfs_buf_iowait() cannot be used because it was pushed with the
1015 * XBF_ASYNC flag set, so we need to use a lock/unlock pair to wait for
1016 * the IO to complete.
1017 */
1018 xfs_ail_push_all_sync(mp->m_ail);
1019 xfs_buftarg_wait(mp->m_ddev_targp);
1020 xfs_buf_lock(mp->m_sb_bp);
1021 xfs_buf_unlock(mp->m_sb_bp);
1022
1023 return xfs_log_cover(mp);
1024}
1025
1026void
1027xfs_log_clean(
1028 struct xfs_mount *mp)
1029{
1030 xfs_log_quiesce(mp);
1031 xfs_log_unmount_write(mp);
1032}
1033
1034/*
1035 * Shut down and release the AIL and Log.
1036 *
1037 * During unmount, we need to ensure we flush all the dirty metadata objects
1038 * from the AIL so that the log is empty before we write the unmount record to
1039 * the log. Once this is done, we can tear down the AIL and the log.
1040 */
1041void
1042xfs_log_unmount(
1043 struct xfs_mount *mp)
1044{
1045 xfs_log_clean(mp);
1046
1047 /*
1048 * If shutdown has come from iclog IO context, the log
1049 * cleaning will have been skipped and so we need to wait
1050 * for the iclog to complete shutdown processing before we
1051 * tear anything down.
1052 */
1053 xlog_wait_iclog_completion(mp->m_log);
1054
1055 xfs_buftarg_drain(mp->m_ddev_targp);
1056
1057 xfs_trans_ail_destroy(mp);
1058
1059 xfs_sysfs_del(&mp->m_log->l_kobj);
1060
1061 xlog_dealloc_log(mp->m_log);
1062}
1063
1064void
1065xfs_log_item_init(
1066 struct xfs_mount *mp,
1067 struct xfs_log_item *item,
1068 int type,
1069 const struct xfs_item_ops *ops)
1070{
1071 item->li_log = mp->m_log;
1072 item->li_ailp = mp->m_ail;
1073 item->li_type = type;
1074 item->li_ops = ops;
1075 item->li_lv = NULL;
1076
1077 INIT_LIST_HEAD(&item->li_ail);
1078 INIT_LIST_HEAD(&item->li_cil);
1079 INIT_LIST_HEAD(&item->li_bio_list);
1080 INIT_LIST_HEAD(&item->li_trans);
1081}
1082
1083/*
1084 * Wake up processes waiting for log space after we have moved the log tail.
1085 */
1086void
1087xfs_log_space_wake(
1088 struct xfs_mount *mp)
1089{
1090 struct xlog *log = mp->m_log;
1091 int free_bytes;
1092
1093 if (xlog_is_shutdown(log))
1094 return;
1095
1096 if (!list_empty_careful(&log->l_write_head.waiters)) {
1097 ASSERT(!xlog_in_recovery(log));
1098
1099 spin_lock(&log->l_write_head.lock);
1100 free_bytes = xlog_grant_space_left(log, &log->l_write_head);
1101 xlog_grant_head_wake(log, &log->l_write_head, &free_bytes);
1102 spin_unlock(&log->l_write_head.lock);
1103 }
1104
1105 if (!list_empty_careful(&log->l_reserve_head.waiters)) {
1106 ASSERT(!xlog_in_recovery(log));
1107
1108 spin_lock(&log->l_reserve_head.lock);
1109 free_bytes = xlog_grant_space_left(log, &log->l_reserve_head);
1110 xlog_grant_head_wake(log, &log->l_reserve_head, &free_bytes);
1111 spin_unlock(&log->l_reserve_head.lock);
1112 }
1113}
1114
1115/*
1116 * Determine if we have a transaction that has gone to disk that needs to be
1117 * covered. To begin the transition to the idle state firstly the log needs to
1118 * be idle. That means the CIL, the AIL and the iclogs needs to be empty before
1119 * we start attempting to cover the log.
1120 *
1121 * Only if we are then in a state where covering is needed, the caller is
1122 * informed that dummy transactions are required to move the log into the idle
1123 * state.
1124 *
1125 * If there are any items in the AIl or CIL, then we do not want to attempt to
1126 * cover the log as we may be in a situation where there isn't log space
1127 * available to run a dummy transaction and this can lead to deadlocks when the
1128 * tail of the log is pinned by an item that is modified in the CIL. Hence
1129 * there's no point in running a dummy transaction at this point because we
1130 * can't start trying to idle the log until both the CIL and AIL are empty.
1131 */
1132static bool
1133xfs_log_need_covered(
1134 struct xfs_mount *mp)
1135{
1136 struct xlog *log = mp->m_log;
1137 bool needed = false;
1138
1139 if (!xlog_cil_empty(log))
1140 return false;
1141
1142 spin_lock(&log->l_icloglock);
1143 switch (log->l_covered_state) {
1144 case XLOG_STATE_COVER_DONE:
1145 case XLOG_STATE_COVER_DONE2:
1146 case XLOG_STATE_COVER_IDLE:
1147 break;
1148 case XLOG_STATE_COVER_NEED:
1149 case XLOG_STATE_COVER_NEED2:
1150 if (xfs_ail_min_lsn(log->l_ailp))
1151 break;
1152 if (!xlog_iclogs_empty(log))
1153 break;
1154
1155 needed = true;
1156 if (log->l_covered_state == XLOG_STATE_COVER_NEED)
1157 log->l_covered_state = XLOG_STATE_COVER_DONE;
1158 else
1159 log->l_covered_state = XLOG_STATE_COVER_DONE2;
1160 break;
1161 default:
1162 needed = true;
1163 break;
1164 }
1165 spin_unlock(&log->l_icloglock);
1166 return needed;
1167}
1168
1169/*
1170 * Explicitly cover the log. This is similar to background log covering but
1171 * intended for usage in quiesce codepaths. The caller is responsible to ensure
1172 * the log is idle and suitable for covering. The CIL, iclog buffers and AIL
1173 * must all be empty.
1174 */
1175static int
1176xfs_log_cover(
1177 struct xfs_mount *mp)
1178{
1179 int error = 0;
1180 bool need_covered;
1181
1182 ASSERT((xlog_cil_empty(mp->m_log) && xlog_iclogs_empty(mp->m_log) &&
1183 !xfs_ail_min_lsn(mp->m_log->l_ailp)) ||
1184 xlog_is_shutdown(mp->m_log));
1185
1186 if (!xfs_log_writable(mp))
1187 return 0;
1188
1189 /*
1190 * xfs_log_need_covered() is not idempotent because it progresses the
1191 * state machine if the log requires covering. Therefore, we must call
1192 * this function once and use the result until we've issued an sb sync.
1193 * Do so first to make that abundantly clear.
1194 *
1195 * Fall into the covering sequence if the log needs covering or the
1196 * mount has lazy superblock accounting to sync to disk. The sb sync
1197 * used for covering accumulates the in-core counters, so covering
1198 * handles this for us.
1199 */
1200 need_covered = xfs_log_need_covered(mp);
1201 if (!need_covered && !xfs_has_lazysbcount(mp))
1202 return 0;
1203
1204 /*
1205 * To cover the log, commit the superblock twice (at most) in
1206 * independent checkpoints. The first serves as a reference for the
1207 * tail pointer. The sync transaction and AIL push empties the AIL and
1208 * updates the in-core tail to the LSN of the first checkpoint. The
1209 * second commit updates the on-disk tail with the in-core LSN,
1210 * covering the log. Push the AIL one more time to leave it empty, as
1211 * we found it.
1212 */
1213 do {
1214 error = xfs_sync_sb(mp, true);
1215 if (error)
1216 break;
1217 xfs_ail_push_all_sync(mp->m_ail);
1218 } while (xfs_log_need_covered(mp));
1219
1220 return error;
1221}
1222
1223static void
1224xlog_ioend_work(
1225 struct work_struct *work)
1226{
1227 struct xlog_in_core *iclog =
1228 container_of(work, struct xlog_in_core, ic_end_io_work);
1229 struct xlog *log = iclog->ic_log;
1230 int error;
1231
1232 error = blk_status_to_errno(iclog->ic_bio.bi_status);
1233#ifdef DEBUG
1234 /* treat writes with injected CRC errors as failed */
1235 if (iclog->ic_fail_crc)
1236 error = -EIO;
1237#endif
1238
1239 /*
1240 * Race to shutdown the filesystem if we see an error.
1241 */
1242 if (XFS_TEST_ERROR(error, log->l_mp, XFS_ERRTAG_IODONE_IOERR)) {
1243 xfs_alert(log->l_mp, "log I/O error %d", error);
1244 xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR);
1245 }
1246
1247 xlog_state_done_syncing(iclog);
1248 bio_uninit(&iclog->ic_bio);
1249
1250 /*
1251 * Drop the lock to signal that we are done. Nothing references the
1252 * iclog after this, so an unmount waiting on this lock can now tear it
1253 * down safely. As such, it is unsafe to reference the iclog after the
1254 * unlock as we could race with it being freed.
1255 */
1256 up(&iclog->ic_sema);
1257}
1258
1259/*
1260 * Return size of each in-core log record buffer.
1261 *
1262 * All machines get 8 x 32kB buffers by default, unless tuned otherwise.
1263 *
1264 * If the filesystem blocksize is too large, we may need to choose a
1265 * larger size since the directory code currently logs entire blocks.
1266 */
1267STATIC void
1268xlog_get_iclog_buffer_size(
1269 struct xfs_mount *mp,
1270 struct xlog *log)
1271{
1272 if (mp->m_logbufs <= 0)
1273 mp->m_logbufs = XLOG_MAX_ICLOGS;
1274 if (mp->m_logbsize <= 0)
1275 mp->m_logbsize = XLOG_BIG_RECORD_BSIZE;
1276
1277 log->l_iclog_bufs = mp->m_logbufs;
1278 log->l_iclog_size = mp->m_logbsize;
1279
1280 /*
1281 * # headers = size / 32k - one header holds cycles from 32k of data.
1282 */
1283 log->l_iclog_heads =
1284 DIV_ROUND_UP(mp->m_logbsize, XLOG_HEADER_CYCLE_SIZE);
1285 log->l_iclog_hsize = log->l_iclog_heads << BBSHIFT;
1286}
1287
1288void
1289xfs_log_work_queue(
1290 struct xfs_mount *mp)
1291{
1292 queue_delayed_work(mp->m_sync_workqueue, &mp->m_log->l_work,
1293 msecs_to_jiffies(xfs_syncd_centisecs * 10));
1294}
1295
1296/*
1297 * Clear the log incompat flags if we have the opportunity.
1298 *
1299 * This only happens if we're about to log the second dummy transaction as part
1300 * of covering the log.
1301 */
1302static inline void
1303xlog_clear_incompat(
1304 struct xlog *log)
1305{
1306 struct xfs_mount *mp = log->l_mp;
1307
1308 if (!xfs_sb_has_incompat_log_feature(&mp->m_sb,
1309 XFS_SB_FEAT_INCOMPAT_LOG_ALL))
1310 return;
1311
1312 if (log->l_covered_state != XLOG_STATE_COVER_DONE2)
1313 return;
1314
1315 xfs_clear_incompat_log_features(mp);
1316}
1317
1318/*
1319 * Every sync period we need to unpin all items in the AIL and push them to
1320 * disk. If there is nothing dirty, then we might need to cover the log to
1321 * indicate that the filesystem is idle.
1322 */
1323static void
1324xfs_log_worker(
1325 struct work_struct *work)
1326{
1327 struct xlog *log = container_of(to_delayed_work(work),
1328 struct xlog, l_work);
1329 struct xfs_mount *mp = log->l_mp;
1330
1331 /* dgc: errors ignored - not fatal and nowhere to report them */
1332 if (xfs_fs_writable(mp, SB_FREEZE_WRITE) && xfs_log_need_covered(mp)) {
1333 /*
1334 * Dump a transaction into the log that contains no real change.
1335 * This is needed to stamp the current tail LSN into the log
1336 * during the covering operation.
1337 *
1338 * We cannot use an inode here for this - that will push dirty
1339 * state back up into the VFS and then periodic inode flushing
1340 * will prevent log covering from making progress. Hence we
1341 * synchronously log the superblock instead to ensure the
1342 * superblock is immediately unpinned and can be written back.
1343 */
1344 xlog_clear_incompat(log);
1345 xfs_sync_sb(mp, true);
1346 } else
1347 xfs_log_force(mp, 0);
1348
1349 /* start pushing all the metadata that is currently dirty */
1350 xfs_ail_push_all(mp->m_ail);
1351
1352 /* queue us up again */
1353 xfs_log_work_queue(mp);
1354}
1355
1356/*
1357 * This routine initializes some of the log structure for a given mount point.
1358 * Its primary purpose is to fill in enough, so recovery can occur. However,
1359 * some other stuff may be filled in too.
1360 */
1361STATIC struct xlog *
1362xlog_alloc_log(
1363 struct xfs_mount *mp,
1364 struct xfs_buftarg *log_target,
1365 xfs_daddr_t blk_offset,
1366 int num_bblks)
1367{
1368 struct xlog *log;
1369 xlog_rec_header_t *head;
1370 xlog_in_core_t **iclogp;
1371 xlog_in_core_t *iclog, *prev_iclog=NULL;
1372 int i;
1373 int error = -ENOMEM;
1374 uint log2_size = 0;
1375
1376 log = kzalloc(sizeof(struct xlog), GFP_KERNEL | __GFP_RETRY_MAYFAIL);
1377 if (!log) {
1378 xfs_warn(mp, "Log allocation failed: No memory!");
1379 goto out;
1380 }
1381
1382 log->l_mp = mp;
1383 log->l_targ = log_target;
1384 log->l_logsize = BBTOB(num_bblks);
1385 log->l_logBBstart = blk_offset;
1386 log->l_logBBsize = num_bblks;
1387 log->l_covered_state = XLOG_STATE_COVER_IDLE;
1388 set_bit(XLOG_ACTIVE_RECOVERY, &log->l_opstate);
1389 INIT_DELAYED_WORK(&log->l_work, xfs_log_worker);
1390 INIT_LIST_HEAD(&log->r_dfops);
1391
1392 log->l_prev_block = -1;
1393 /* log->l_tail_lsn = 0x100000000LL; cycle = 1; current block = 0 */
1394 xlog_assign_atomic_lsn(&log->l_tail_lsn, 1, 0);
1395 log->l_curr_cycle = 1; /* 0 is bad since this is initial value */
1396
1397 if (xfs_has_logv2(mp) && mp->m_sb.sb_logsunit > 1)
1398 log->l_iclog_roundoff = mp->m_sb.sb_logsunit;
1399 else
1400 log->l_iclog_roundoff = BBSIZE;
1401
1402 xlog_grant_head_init(&log->l_reserve_head);
1403 xlog_grant_head_init(&log->l_write_head);
1404
1405 error = -EFSCORRUPTED;
1406 if (xfs_has_sector(mp)) {
1407 log2_size = mp->m_sb.sb_logsectlog;
1408 if (log2_size < BBSHIFT) {
1409 xfs_warn(mp, "Log sector size too small (0x%x < 0x%x)",
1410 log2_size, BBSHIFT);
1411 goto out_free_log;
1412 }
1413
1414 log2_size -= BBSHIFT;
1415 if (log2_size > mp->m_sectbb_log) {
1416 xfs_warn(mp, "Log sector size too large (0x%x > 0x%x)",
1417 log2_size, mp->m_sectbb_log);
1418 goto out_free_log;
1419 }
1420
1421 /* for larger sector sizes, must have v2 or external log */
1422 if (log2_size && log->l_logBBstart > 0 &&
1423 !xfs_has_logv2(mp)) {
1424 xfs_warn(mp,
1425 "log sector size (0x%x) invalid for configuration.",
1426 log2_size);
1427 goto out_free_log;
1428 }
1429 }
1430 log->l_sectBBsize = 1 << log2_size;
1431
1432 xlog_get_iclog_buffer_size(mp, log);
1433
1434 spin_lock_init(&log->l_icloglock);
1435 init_waitqueue_head(&log->l_flush_wait);
1436
1437 iclogp = &log->l_iclog;
1438 /*
1439 * The amount of memory to allocate for the iclog structure is
1440 * rather funky due to the way the structure is defined. It is
1441 * done this way so that we can use different sizes for machines
1442 * with different amounts of memory. See the definition of
1443 * xlog_in_core_t in xfs_log_priv.h for details.
1444 */
1445 ASSERT(log->l_iclog_size >= 4096);
1446 for (i = 0; i < log->l_iclog_bufs; i++) {
1447 size_t bvec_size = howmany(log->l_iclog_size, PAGE_SIZE) *
1448 sizeof(struct bio_vec);
1449
1450 iclog = kzalloc(sizeof(*iclog) + bvec_size,
1451 GFP_KERNEL | __GFP_RETRY_MAYFAIL);
1452 if (!iclog)
1453 goto out_free_iclog;
1454
1455 *iclogp = iclog;
1456 iclog->ic_prev = prev_iclog;
1457 prev_iclog = iclog;
1458
1459 iclog->ic_data = kvzalloc(log->l_iclog_size,
1460 GFP_KERNEL | __GFP_RETRY_MAYFAIL);
1461 if (!iclog->ic_data)
1462 goto out_free_iclog;
1463 head = &iclog->ic_header;
1464 memset(head, 0, sizeof(xlog_rec_header_t));
1465 head->h_magicno = cpu_to_be32(XLOG_HEADER_MAGIC_NUM);
1466 head->h_version = cpu_to_be32(
1467 xfs_has_logv2(log->l_mp) ? 2 : 1);
1468 head->h_size = cpu_to_be32(log->l_iclog_size);
1469 /* new fields */
1470 head->h_fmt = cpu_to_be32(XLOG_FMT);
1471 memcpy(&head->h_fs_uuid, &mp->m_sb.sb_uuid, sizeof(uuid_t));
1472
1473 iclog->ic_size = log->l_iclog_size - log->l_iclog_hsize;
1474 iclog->ic_state = XLOG_STATE_ACTIVE;
1475 iclog->ic_log = log;
1476 atomic_set(&iclog->ic_refcnt, 0);
1477 INIT_LIST_HEAD(&iclog->ic_callbacks);
1478 iclog->ic_datap = (void *)iclog->ic_data + log->l_iclog_hsize;
1479
1480 init_waitqueue_head(&iclog->ic_force_wait);
1481 init_waitqueue_head(&iclog->ic_write_wait);
1482 INIT_WORK(&iclog->ic_end_io_work, xlog_ioend_work);
1483 sema_init(&iclog->ic_sema, 1);
1484
1485 iclogp = &iclog->ic_next;
1486 }
1487 *iclogp = log->l_iclog; /* complete ring */
1488 log->l_iclog->ic_prev = prev_iclog; /* re-write 1st prev ptr */
1489
1490 log->l_ioend_workqueue = alloc_workqueue("xfs-log/%s",
1491 XFS_WQFLAGS(WQ_FREEZABLE | WQ_MEM_RECLAIM |
1492 WQ_HIGHPRI),
1493 0, mp->m_super->s_id);
1494 if (!log->l_ioend_workqueue)
1495 goto out_free_iclog;
1496
1497 error = xlog_cil_init(log);
1498 if (error)
1499 goto out_destroy_workqueue;
1500 return log;
1501
1502out_destroy_workqueue:
1503 destroy_workqueue(log->l_ioend_workqueue);
1504out_free_iclog:
1505 for (iclog = log->l_iclog; iclog; iclog = prev_iclog) {
1506 prev_iclog = iclog->ic_next;
1507 kvfree(iclog->ic_data);
1508 kfree(iclog);
1509 if (prev_iclog == log->l_iclog)
1510 break;
1511 }
1512out_free_log:
1513 kfree(log);
1514out:
1515 return ERR_PTR(error);
1516} /* xlog_alloc_log */
1517
1518/*
1519 * Stamp cycle number in every block
1520 */
1521STATIC void
1522xlog_pack_data(
1523 struct xlog *log,
1524 struct xlog_in_core *iclog,
1525 int roundoff)
1526{
1527 int i, j, k;
1528 int size = iclog->ic_offset + roundoff;
1529 __be32 cycle_lsn;
1530 char *dp;
1531
1532 cycle_lsn = CYCLE_LSN_DISK(iclog->ic_header.h_lsn);
1533
1534 dp = iclog->ic_datap;
1535 for (i = 0; i < BTOBB(size); i++) {
1536 if (i >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE))
1537 break;
1538 iclog->ic_header.h_cycle_data[i] = *(__be32 *)dp;
1539 *(__be32 *)dp = cycle_lsn;
1540 dp += BBSIZE;
1541 }
1542
1543 if (xfs_has_logv2(log->l_mp)) {
1544 xlog_in_core_2_t *xhdr = iclog->ic_data;
1545
1546 for ( ; i < BTOBB(size); i++) {
1547 j = i / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
1548 k = i % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
1549 xhdr[j].hic_xheader.xh_cycle_data[k] = *(__be32 *)dp;
1550 *(__be32 *)dp = cycle_lsn;
1551 dp += BBSIZE;
1552 }
1553
1554 for (i = 1; i < log->l_iclog_heads; i++)
1555 xhdr[i].hic_xheader.xh_cycle = cycle_lsn;
1556 }
1557}
1558
1559/*
1560 * Calculate the checksum for a log buffer.
1561 *
1562 * This is a little more complicated than it should be because the various
1563 * headers and the actual data are non-contiguous.
1564 */
1565__le32
1566xlog_cksum(
1567 struct xlog *log,
1568 struct xlog_rec_header *rhead,
1569 char *dp,
1570 int size)
1571{
1572 uint32_t crc;
1573
1574 /* first generate the crc for the record header ... */
1575 crc = xfs_start_cksum_update((char *)rhead,
1576 sizeof(struct xlog_rec_header),
1577 offsetof(struct xlog_rec_header, h_crc));
1578
1579 /* ... then for additional cycle data for v2 logs ... */
1580 if (xfs_has_logv2(log->l_mp)) {
1581 union xlog_in_core2 *xhdr = (union xlog_in_core2 *)rhead;
1582 int i;
1583 int xheads;
1584
1585 xheads = DIV_ROUND_UP(size, XLOG_HEADER_CYCLE_SIZE);
1586
1587 for (i = 1; i < xheads; i++) {
1588 crc = crc32c(crc, &xhdr[i].hic_xheader,
1589 sizeof(struct xlog_rec_ext_header));
1590 }
1591 }
1592
1593 /* ... and finally for the payload */
1594 crc = crc32c(crc, dp, size);
1595
1596 return xfs_end_cksum(crc);
1597}
1598
1599static void
1600xlog_bio_end_io(
1601 struct bio *bio)
1602{
1603 struct xlog_in_core *iclog = bio->bi_private;
1604
1605 queue_work(iclog->ic_log->l_ioend_workqueue,
1606 &iclog->ic_end_io_work);
1607}
1608
1609static int
1610xlog_map_iclog_data(
1611 struct bio *bio,
1612 void *data,
1613 size_t count)
1614{
1615 do {
1616 struct page *page = kmem_to_page(data);
1617 unsigned int off = offset_in_page(data);
1618 size_t len = min_t(size_t, count, PAGE_SIZE - off);
1619
1620 if (bio_add_page(bio, page, len, off) != len)
1621 return -EIO;
1622
1623 data += len;
1624 count -= len;
1625 } while (count);
1626
1627 return 0;
1628}
1629
1630STATIC void
1631xlog_write_iclog(
1632 struct xlog *log,
1633 struct xlog_in_core *iclog,
1634 uint64_t bno,
1635 unsigned int count)
1636{
1637 ASSERT(bno < log->l_logBBsize);
1638 trace_xlog_iclog_write(iclog, _RET_IP_);
1639
1640 /*
1641 * We lock the iclogbufs here so that we can serialise against I/O
1642 * completion during unmount. We might be processing a shutdown
1643 * triggered during unmount, and that can occur asynchronously to the
1644 * unmount thread, and hence we need to ensure that completes before
1645 * tearing down the iclogbufs. Hence we need to hold the buffer lock
1646 * across the log IO to archieve that.
1647 */
1648 down(&iclog->ic_sema);
1649 if (xlog_is_shutdown(log)) {
1650 /*
1651 * It would seem logical to return EIO here, but we rely on
1652 * the log state machine to propagate I/O errors instead of
1653 * doing it here. We kick of the state machine and unlock
1654 * the buffer manually, the code needs to be kept in sync
1655 * with the I/O completion path.
1656 */
1657 goto sync;
1658 }
1659
1660 /*
1661 * We use REQ_SYNC | REQ_IDLE here to tell the block layer the are more
1662 * IOs coming immediately after this one. This prevents the block layer
1663 * writeback throttle from throttling log writes behind background
1664 * metadata writeback and causing priority inversions.
1665 */
1666 bio_init(&iclog->ic_bio, log->l_targ->bt_bdev, iclog->ic_bvec,
1667 howmany(count, PAGE_SIZE),
1668 REQ_OP_WRITE | REQ_META | REQ_SYNC | REQ_IDLE);
1669 iclog->ic_bio.bi_iter.bi_sector = log->l_logBBstart + bno;
1670 iclog->ic_bio.bi_end_io = xlog_bio_end_io;
1671 iclog->ic_bio.bi_private = iclog;
1672
1673 if (iclog->ic_flags & XLOG_ICL_NEED_FLUSH) {
1674 iclog->ic_bio.bi_opf |= REQ_PREFLUSH;
1675 /*
1676 * For external log devices, we also need to flush the data
1677 * device cache first to ensure all metadata writeback covered
1678 * by the LSN in this iclog is on stable storage. This is slow,
1679 * but it *must* complete before we issue the external log IO.
1680 *
1681 * If the flush fails, we cannot conclude that past metadata
1682 * writeback from the log succeeded. Repeating the flush is
1683 * not possible, hence we must shut down with log IO error to
1684 * avoid shutdown re-entering this path and erroring out again.
1685 */
1686 if (log->l_targ != log->l_mp->m_ddev_targp &&
1687 blkdev_issue_flush(log->l_mp->m_ddev_targp->bt_bdev))
1688 goto shutdown;
1689 }
1690 if (iclog->ic_flags & XLOG_ICL_NEED_FUA)
1691 iclog->ic_bio.bi_opf |= REQ_FUA;
1692
1693 iclog->ic_flags &= ~(XLOG_ICL_NEED_FLUSH | XLOG_ICL_NEED_FUA);
1694
1695 if (xlog_map_iclog_data(&iclog->ic_bio, iclog->ic_data, count))
1696 goto shutdown;
1697
1698 if (is_vmalloc_addr(iclog->ic_data))
1699 flush_kernel_vmap_range(iclog->ic_data, count);
1700
1701 /*
1702 * If this log buffer would straddle the end of the log we will have
1703 * to split it up into two bios, so that we can continue at the start.
1704 */
1705 if (bno + BTOBB(count) > log->l_logBBsize) {
1706 struct bio *split;
1707
1708 split = bio_split(&iclog->ic_bio, log->l_logBBsize - bno,
1709 GFP_NOIO, &fs_bio_set);
1710 bio_chain(split, &iclog->ic_bio);
1711 submit_bio(split);
1712
1713 /* restart at logical offset zero for the remainder */
1714 iclog->ic_bio.bi_iter.bi_sector = log->l_logBBstart;
1715 }
1716
1717 submit_bio(&iclog->ic_bio);
1718 return;
1719shutdown:
1720 xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR);
1721sync:
1722 xlog_state_done_syncing(iclog);
1723 up(&iclog->ic_sema);
1724}
1725
1726/*
1727 * We need to bump cycle number for the part of the iclog that is
1728 * written to the start of the log. Watch out for the header magic
1729 * number case, though.
1730 */
1731static void
1732xlog_split_iclog(
1733 struct xlog *log,
1734 void *data,
1735 uint64_t bno,
1736 unsigned int count)
1737{
1738 unsigned int split_offset = BBTOB(log->l_logBBsize - bno);
1739 unsigned int i;
1740
1741 for (i = split_offset; i < count; i += BBSIZE) {
1742 uint32_t cycle = get_unaligned_be32(data + i);
1743
1744 if (++cycle == XLOG_HEADER_MAGIC_NUM)
1745 cycle++;
1746 put_unaligned_be32(cycle, data + i);
1747 }
1748}
1749
1750static int
1751xlog_calc_iclog_size(
1752 struct xlog *log,
1753 struct xlog_in_core *iclog,
1754 uint32_t *roundoff)
1755{
1756 uint32_t count_init, count;
1757
1758 /* Add for LR header */
1759 count_init = log->l_iclog_hsize + iclog->ic_offset;
1760 count = roundup(count_init, log->l_iclog_roundoff);
1761
1762 *roundoff = count - count_init;
1763
1764 ASSERT(count >= count_init);
1765 ASSERT(*roundoff < log->l_iclog_roundoff);
1766 return count;
1767}
1768
1769/*
1770 * Flush out the in-core log (iclog) to the on-disk log in an asynchronous
1771 * fashion. Previously, we should have moved the current iclog
1772 * ptr in the log to point to the next available iclog. This allows further
1773 * write to continue while this code syncs out an iclog ready to go.
1774 * Before an in-core log can be written out, the data section must be scanned
1775 * to save away the 1st word of each BBSIZE block into the header. We replace
1776 * it with the current cycle count. Each BBSIZE block is tagged with the
1777 * cycle count because there in an implicit assumption that drives will
1778 * guarantee that entire 512 byte blocks get written at once. In other words,
1779 * we can't have part of a 512 byte block written and part not written. By
1780 * tagging each block, we will know which blocks are valid when recovering
1781 * after an unclean shutdown.
1782 *
1783 * This routine is single threaded on the iclog. No other thread can be in
1784 * this routine with the same iclog. Changing contents of iclog can there-
1785 * fore be done without grabbing the state machine lock. Updating the global
1786 * log will require grabbing the lock though.
1787 *
1788 * The entire log manager uses a logical block numbering scheme. Only
1789 * xlog_write_iclog knows about the fact that the log may not start with
1790 * block zero on a given device.
1791 */
1792STATIC void
1793xlog_sync(
1794 struct xlog *log,
1795 struct xlog_in_core *iclog,
1796 struct xlog_ticket *ticket)
1797{
1798 unsigned int count; /* byte count of bwrite */
1799 unsigned int roundoff; /* roundoff to BB or stripe */
1800 uint64_t bno;
1801 unsigned int size;
1802
1803 ASSERT(atomic_read(&iclog->ic_refcnt) == 0);
1804 trace_xlog_iclog_sync(iclog, _RET_IP_);
1805
1806 count = xlog_calc_iclog_size(log, iclog, &roundoff);
1807
1808 /*
1809 * If we have a ticket, account for the roundoff via the ticket
1810 * reservation to avoid touching the hot grant heads needlessly.
1811 * Otherwise, we have to move grant heads directly.
1812 */
1813 if (ticket) {
1814 ticket->t_curr_res -= roundoff;
1815 } else {
1816 xlog_grant_add_space(&log->l_reserve_head, roundoff);
1817 xlog_grant_add_space(&log->l_write_head, roundoff);
1818 }
1819
1820 /* put cycle number in every block */
1821 xlog_pack_data(log, iclog, roundoff);
1822
1823 /* real byte length */
1824 size = iclog->ic_offset;
1825 if (xfs_has_logv2(log->l_mp))
1826 size += roundoff;
1827 iclog->ic_header.h_len = cpu_to_be32(size);
1828
1829 XFS_STATS_INC(log->l_mp, xs_log_writes);
1830 XFS_STATS_ADD(log->l_mp, xs_log_blocks, BTOBB(count));
1831
1832 bno = BLOCK_LSN(be64_to_cpu(iclog->ic_header.h_lsn));
1833
1834 /* Do we need to split this write into 2 parts? */
1835 if (bno + BTOBB(count) > log->l_logBBsize)
1836 xlog_split_iclog(log, &iclog->ic_header, bno, count);
1837
1838 /* calculcate the checksum */
1839 iclog->ic_header.h_crc = xlog_cksum(log, &iclog->ic_header,
1840 iclog->ic_datap, size);
1841 /*
1842 * Intentionally corrupt the log record CRC based on the error injection
1843 * frequency, if defined. This facilitates testing log recovery in the
1844 * event of torn writes. Hence, set the IOABORT state to abort the log
1845 * write on I/O completion and shutdown the fs. The subsequent mount
1846 * detects the bad CRC and attempts to recover.
1847 */
1848#ifdef DEBUG
1849 if (XFS_TEST_ERROR(false, log->l_mp, XFS_ERRTAG_LOG_BAD_CRC)) {
1850 iclog->ic_header.h_crc &= cpu_to_le32(0xAAAAAAAA);
1851 iclog->ic_fail_crc = true;
1852 xfs_warn(log->l_mp,
1853 "Intentionally corrupted log record at LSN 0x%llx. Shutdown imminent.",
1854 be64_to_cpu(iclog->ic_header.h_lsn));
1855 }
1856#endif
1857 xlog_verify_iclog(log, iclog, count);
1858 xlog_write_iclog(log, iclog, bno, count);
1859}
1860
1861/*
1862 * Deallocate a log structure
1863 */
1864STATIC void
1865xlog_dealloc_log(
1866 struct xlog *log)
1867{
1868 xlog_in_core_t *iclog, *next_iclog;
1869 int i;
1870
1871 /*
1872 * Destroy the CIL after waiting for iclog IO completion because an
1873 * iclog EIO error will try to shut down the log, which accesses the
1874 * CIL to wake up the waiters.
1875 */
1876 xlog_cil_destroy(log);
1877
1878 iclog = log->l_iclog;
1879 for (i = 0; i < log->l_iclog_bufs; i++) {
1880 next_iclog = iclog->ic_next;
1881 kvfree(iclog->ic_data);
1882 kfree(iclog);
1883 iclog = next_iclog;
1884 }
1885
1886 log->l_mp->m_log = NULL;
1887 destroy_workqueue(log->l_ioend_workqueue);
1888 kfree(log);
1889}
1890
1891/*
1892 * Update counters atomically now that memcpy is done.
1893 */
1894static inline void
1895xlog_state_finish_copy(
1896 struct xlog *log,
1897 struct xlog_in_core *iclog,
1898 int record_cnt,
1899 int copy_bytes)
1900{
1901 lockdep_assert_held(&log->l_icloglock);
1902
1903 be32_add_cpu(&iclog->ic_header.h_num_logops, record_cnt);
1904 iclog->ic_offset += copy_bytes;
1905}
1906
1907/*
1908 * print out info relating to regions written which consume
1909 * the reservation
1910 */
1911void
1912xlog_print_tic_res(
1913 struct xfs_mount *mp,
1914 struct xlog_ticket *ticket)
1915{
1916 xfs_warn(mp, "ticket reservation summary:");
1917 xfs_warn(mp, " unit res = %d bytes", ticket->t_unit_res);
1918 xfs_warn(mp, " current res = %d bytes", ticket->t_curr_res);
1919 xfs_warn(mp, " original count = %d", ticket->t_ocnt);
1920 xfs_warn(mp, " remaining count = %d", ticket->t_cnt);
1921}
1922
1923/*
1924 * Print a summary of the transaction.
1925 */
1926void
1927xlog_print_trans(
1928 struct xfs_trans *tp)
1929{
1930 struct xfs_mount *mp = tp->t_mountp;
1931 struct xfs_log_item *lip;
1932
1933 /* dump core transaction and ticket info */
1934 xfs_warn(mp, "transaction summary:");
1935 xfs_warn(mp, " log res = %d", tp->t_log_res);
1936 xfs_warn(mp, " log count = %d", tp->t_log_count);
1937 xfs_warn(mp, " flags = 0x%x", tp->t_flags);
1938
1939 xlog_print_tic_res(mp, tp->t_ticket);
1940
1941 /* dump each log item */
1942 list_for_each_entry(lip, &tp->t_items, li_trans) {
1943 struct xfs_log_vec *lv = lip->li_lv;
1944 struct xfs_log_iovec *vec;
1945 int i;
1946
1947 xfs_warn(mp, "log item: ");
1948 xfs_warn(mp, " type = 0x%x", lip->li_type);
1949 xfs_warn(mp, " flags = 0x%lx", lip->li_flags);
1950 if (!lv)
1951 continue;
1952 xfs_warn(mp, " niovecs = %d", lv->lv_niovecs);
1953 xfs_warn(mp, " size = %d", lv->lv_size);
1954 xfs_warn(mp, " bytes = %d", lv->lv_bytes);
1955 xfs_warn(mp, " buf len = %d", lv->lv_buf_len);
1956
1957 /* dump each iovec for the log item */
1958 vec = lv->lv_iovecp;
1959 for (i = 0; i < lv->lv_niovecs; i++) {
1960 int dumplen = min(vec->i_len, 32);
1961
1962 xfs_warn(mp, " iovec[%d]", i);
1963 xfs_warn(mp, " type = 0x%x", vec->i_type);
1964 xfs_warn(mp, " len = %d", vec->i_len);
1965 xfs_warn(mp, " first %d bytes of iovec[%d]:", dumplen, i);
1966 xfs_hex_dump(vec->i_addr, dumplen);
1967
1968 vec++;
1969 }
1970 }
1971}
1972
1973static inline void
1974xlog_write_iovec(
1975 struct xlog_in_core *iclog,
1976 uint32_t *log_offset,
1977 void *data,
1978 uint32_t write_len,
1979 int *bytes_left,
1980 uint32_t *record_cnt,
1981 uint32_t *data_cnt)
1982{
1983 ASSERT(*log_offset < iclog->ic_log->l_iclog_size);
1984 ASSERT(*log_offset % sizeof(int32_t) == 0);
1985 ASSERT(write_len % sizeof(int32_t) == 0);
1986
1987 memcpy(iclog->ic_datap + *log_offset, data, write_len);
1988 *log_offset += write_len;
1989 *bytes_left -= write_len;
1990 (*record_cnt)++;
1991 *data_cnt += write_len;
1992}
1993
1994/*
1995 * Write log vectors into a single iclog which is guaranteed by the caller
1996 * to have enough space to write the entire log vector into.
1997 */
1998static void
1999xlog_write_full(
2000 struct xfs_log_vec *lv,
2001 struct xlog_ticket *ticket,
2002 struct xlog_in_core *iclog,
2003 uint32_t *log_offset,
2004 uint32_t *len,
2005 uint32_t *record_cnt,
2006 uint32_t *data_cnt)
2007{
2008 int index;
2009
2010 ASSERT(*log_offset + *len <= iclog->ic_size ||
2011 iclog->ic_state == XLOG_STATE_WANT_SYNC);
2012
2013 /*
2014 * Ordered log vectors have no regions to write so this
2015 * loop will naturally skip them.
2016 */
2017 for (index = 0; index < lv->lv_niovecs; index++) {
2018 struct xfs_log_iovec *reg = &lv->lv_iovecp[index];
2019 struct xlog_op_header *ophdr = reg->i_addr;
2020
2021 ophdr->oh_tid = cpu_to_be32(ticket->t_tid);
2022 xlog_write_iovec(iclog, log_offset, reg->i_addr,
2023 reg->i_len, len, record_cnt, data_cnt);
2024 }
2025}
2026
2027static int
2028xlog_write_get_more_iclog_space(
2029 struct xlog_ticket *ticket,
2030 struct xlog_in_core **iclogp,
2031 uint32_t *log_offset,
2032 uint32_t len,
2033 uint32_t *record_cnt,
2034 uint32_t *data_cnt)
2035{
2036 struct xlog_in_core *iclog = *iclogp;
2037 struct xlog *log = iclog->ic_log;
2038 int error;
2039
2040 spin_lock(&log->l_icloglock);
2041 ASSERT(iclog->ic_state == XLOG_STATE_WANT_SYNC);
2042 xlog_state_finish_copy(log, iclog, *record_cnt, *data_cnt);
2043 error = xlog_state_release_iclog(log, iclog, ticket);
2044 spin_unlock(&log->l_icloglock);
2045 if (error)
2046 return error;
2047
2048 error = xlog_state_get_iclog_space(log, len, &iclog, ticket,
2049 log_offset);
2050 if (error)
2051 return error;
2052 *record_cnt = 0;
2053 *data_cnt = 0;
2054 *iclogp = iclog;
2055 return 0;
2056}
2057
2058/*
2059 * Write log vectors into a single iclog which is smaller than the current chain
2060 * length. We write until we cannot fit a full record into the remaining space
2061 * and then stop. We return the log vector that is to be written that cannot
2062 * wholly fit in the iclog.
2063 */
2064static int
2065xlog_write_partial(
2066 struct xfs_log_vec *lv,
2067 struct xlog_ticket *ticket,
2068 struct xlog_in_core **iclogp,
2069 uint32_t *log_offset,
2070 uint32_t *len,
2071 uint32_t *record_cnt,
2072 uint32_t *data_cnt)
2073{
2074 struct xlog_in_core *iclog = *iclogp;
2075 struct xlog_op_header *ophdr;
2076 int index = 0;
2077 uint32_t rlen;
2078 int error;
2079
2080 /* walk the logvec, copying until we run out of space in the iclog */
2081 for (index = 0; index < lv->lv_niovecs; index++) {
2082 struct xfs_log_iovec *reg = &lv->lv_iovecp[index];
2083 uint32_t reg_offset = 0;
2084
2085 /*
2086 * The first region of a continuation must have a non-zero
2087 * length otherwise log recovery will just skip over it and
2088 * start recovering from the next opheader it finds. Because we
2089 * mark the next opheader as a continuation, recovery will then
2090 * incorrectly add the continuation to the previous region and
2091 * that breaks stuff.
2092 *
2093 * Hence if there isn't space for region data after the
2094 * opheader, then we need to start afresh with a new iclog.
2095 */
2096 if (iclog->ic_size - *log_offset <=
2097 sizeof(struct xlog_op_header)) {
2098 error = xlog_write_get_more_iclog_space(ticket,
2099 &iclog, log_offset, *len, record_cnt,
2100 data_cnt);
2101 if (error)
2102 return error;
2103 }
2104
2105 ophdr = reg->i_addr;
2106 rlen = min_t(uint32_t, reg->i_len, iclog->ic_size - *log_offset);
2107
2108 ophdr->oh_tid = cpu_to_be32(ticket->t_tid);
2109 ophdr->oh_len = cpu_to_be32(rlen - sizeof(struct xlog_op_header));
2110 if (rlen != reg->i_len)
2111 ophdr->oh_flags |= XLOG_CONTINUE_TRANS;
2112
2113 xlog_write_iovec(iclog, log_offset, reg->i_addr,
2114 rlen, len, record_cnt, data_cnt);
2115
2116 /* If we wrote the whole region, move to the next. */
2117 if (rlen == reg->i_len)
2118 continue;
2119
2120 /*
2121 * We now have a partially written iovec, but it can span
2122 * multiple iclogs so we loop here. First we release the iclog
2123 * we currently have, then we get a new iclog and add a new
2124 * opheader. Then we continue copying from where we were until
2125 * we either complete the iovec or fill the iclog. If we
2126 * complete the iovec, then we increment the index and go right
2127 * back to the top of the outer loop. if we fill the iclog, we
2128 * run the inner loop again.
2129 *
2130 * This is complicated by the tail of a region using all the
2131 * space in an iclog and hence requiring us to release the iclog
2132 * and get a new one before returning to the outer loop. We must
2133 * always guarantee that we exit this inner loop with at least
2134 * space for log transaction opheaders left in the current
2135 * iclog, hence we cannot just terminate the loop at the end
2136 * of the of the continuation. So we loop while there is no
2137 * space left in the current iclog, and check for the end of the
2138 * continuation after getting a new iclog.
2139 */
2140 do {
2141 /*
2142 * Ensure we include the continuation opheader in the
2143 * space we need in the new iclog by adding that size
2144 * to the length we require. This continuation opheader
2145 * needs to be accounted to the ticket as the space it
2146 * consumes hasn't been accounted to the lv we are
2147 * writing.
2148 */
2149 error = xlog_write_get_more_iclog_space(ticket,
2150 &iclog, log_offset,
2151 *len + sizeof(struct xlog_op_header),
2152 record_cnt, data_cnt);
2153 if (error)
2154 return error;
2155
2156 ophdr = iclog->ic_datap + *log_offset;
2157 ophdr->oh_tid = cpu_to_be32(ticket->t_tid);
2158 ophdr->oh_clientid = XFS_TRANSACTION;
2159 ophdr->oh_res2 = 0;
2160 ophdr->oh_flags = XLOG_WAS_CONT_TRANS;
2161
2162 ticket->t_curr_res -= sizeof(struct xlog_op_header);
2163 *log_offset += sizeof(struct xlog_op_header);
2164 *data_cnt += sizeof(struct xlog_op_header);
2165
2166 /*
2167 * If rlen fits in the iclog, then end the region
2168 * continuation. Otherwise we're going around again.
2169 */
2170 reg_offset += rlen;
2171 rlen = reg->i_len - reg_offset;
2172 if (rlen <= iclog->ic_size - *log_offset)
2173 ophdr->oh_flags |= XLOG_END_TRANS;
2174 else
2175 ophdr->oh_flags |= XLOG_CONTINUE_TRANS;
2176
2177 rlen = min_t(uint32_t, rlen, iclog->ic_size - *log_offset);
2178 ophdr->oh_len = cpu_to_be32(rlen);
2179
2180 xlog_write_iovec(iclog, log_offset,
2181 reg->i_addr + reg_offset,
2182 rlen, len, record_cnt, data_cnt);
2183
2184 } while (ophdr->oh_flags & XLOG_CONTINUE_TRANS);
2185 }
2186
2187 /*
2188 * No more iovecs remain in this logvec so return the next log vec to
2189 * the caller so it can go back to fast path copying.
2190 */
2191 *iclogp = iclog;
2192 return 0;
2193}
2194
2195/*
2196 * Write some region out to in-core log
2197 *
2198 * This will be called when writing externally provided regions or when
2199 * writing out a commit record for a given transaction.
2200 *
2201 * General algorithm:
2202 * 1. Find total length of this write. This may include adding to the
2203 * lengths passed in.
2204 * 2. Check whether we violate the tickets reservation.
2205 * 3. While writing to this iclog
2206 * A. Reserve as much space in this iclog as can get
2207 * B. If this is first write, save away start lsn
2208 * C. While writing this region:
2209 * 1. If first write of transaction, write start record
2210 * 2. Write log operation header (header per region)
2211 * 3. Find out if we can fit entire region into this iclog
2212 * 4. Potentially, verify destination memcpy ptr
2213 * 5. Memcpy (partial) region
2214 * 6. If partial copy, release iclog; otherwise, continue
2215 * copying more regions into current iclog
2216 * 4. Mark want sync bit (in simulation mode)
2217 * 5. Release iclog for potential flush to on-disk log.
2218 *
2219 * ERRORS:
2220 * 1. Panic if reservation is overrun. This should never happen since
2221 * reservation amounts are generated internal to the filesystem.
2222 * NOTES:
2223 * 1. Tickets are single threaded data structures.
2224 * 2. The XLOG_END_TRANS & XLOG_CONTINUE_TRANS flags are passed down to the
2225 * syncing routine. When a single log_write region needs to span
2226 * multiple in-core logs, the XLOG_CONTINUE_TRANS bit should be set
2227 * on all log operation writes which don't contain the end of the
2228 * region. The XLOG_END_TRANS bit is used for the in-core log
2229 * operation which contains the end of the continued log_write region.
2230 * 3. When xlog_state_get_iclog_space() grabs the rest of the current iclog,
2231 * we don't really know exactly how much space will be used. As a result,
2232 * we don't update ic_offset until the end when we know exactly how many
2233 * bytes have been written out.
2234 */
2235int
2236xlog_write(
2237 struct xlog *log,
2238 struct xfs_cil_ctx *ctx,
2239 struct list_head *lv_chain,
2240 struct xlog_ticket *ticket,
2241 uint32_t len)
2242
2243{
2244 struct xlog_in_core *iclog = NULL;
2245 struct xfs_log_vec *lv;
2246 uint32_t record_cnt = 0;
2247 uint32_t data_cnt = 0;
2248 int error = 0;
2249 int log_offset;
2250
2251 if (ticket->t_curr_res < 0) {
2252 xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES,
2253 "ctx ticket reservation ran out. Need to up reservation");
2254 xlog_print_tic_res(log->l_mp, ticket);
2255 xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR);
2256 }
2257
2258 error = xlog_state_get_iclog_space(log, len, &iclog, ticket,
2259 &log_offset);
2260 if (error)
2261 return error;
2262
2263 ASSERT(log_offset <= iclog->ic_size - 1);
2264
2265 /*
2266 * If we have a context pointer, pass it the first iclog we are
2267 * writing to so it can record state needed for iclog write
2268 * ordering.
2269 */
2270 if (ctx)
2271 xlog_cil_set_ctx_write_state(ctx, iclog);
2272
2273 list_for_each_entry(lv, lv_chain, lv_list) {
2274 /*
2275 * If the entire log vec does not fit in the iclog, punt it to
2276 * the partial copy loop which can handle this case.
2277 */
2278 if (lv->lv_niovecs &&
2279 lv->lv_bytes > iclog->ic_size - log_offset) {
2280 error = xlog_write_partial(lv, ticket, &iclog,
2281 &log_offset, &len, &record_cnt,
2282 &data_cnt);
2283 if (error) {
2284 /*
2285 * We have no iclog to release, so just return
2286 * the error immediately.
2287 */
2288 return error;
2289 }
2290 } else {
2291 xlog_write_full(lv, ticket, iclog, &log_offset,
2292 &len, &record_cnt, &data_cnt);
2293 }
2294 }
2295 ASSERT(len == 0);
2296
2297 /*
2298 * We've already been guaranteed that the last writes will fit inside
2299 * the current iclog, and hence it will already have the space used by
2300 * those writes accounted to it. Hence we do not need to update the
2301 * iclog with the number of bytes written here.
2302 */
2303 spin_lock(&log->l_icloglock);
2304 xlog_state_finish_copy(log, iclog, record_cnt, 0);
2305 error = xlog_state_release_iclog(log, iclog, ticket);
2306 spin_unlock(&log->l_icloglock);
2307
2308 return error;
2309}
2310
2311static void
2312xlog_state_activate_iclog(
2313 struct xlog_in_core *iclog,
2314 int *iclogs_changed)
2315{
2316 ASSERT(list_empty_careful(&iclog->ic_callbacks));
2317 trace_xlog_iclog_activate(iclog, _RET_IP_);
2318
2319 /*
2320 * If the number of ops in this iclog indicate it just contains the
2321 * dummy transaction, we can change state into IDLE (the second time
2322 * around). Otherwise we should change the state into NEED a dummy.
2323 * We don't need to cover the dummy.
2324 */
2325 if (*iclogs_changed == 0 &&
2326 iclog->ic_header.h_num_logops == cpu_to_be32(XLOG_COVER_OPS)) {
2327 *iclogs_changed = 1;
2328 } else {
2329 /*
2330 * We have two dirty iclogs so start over. This could also be
2331 * num of ops indicating this is not the dummy going out.
2332 */
2333 *iclogs_changed = 2;
2334 }
2335
2336 iclog->ic_state = XLOG_STATE_ACTIVE;
2337 iclog->ic_offset = 0;
2338 iclog->ic_header.h_num_logops = 0;
2339 memset(iclog->ic_header.h_cycle_data, 0,
2340 sizeof(iclog->ic_header.h_cycle_data));
2341 iclog->ic_header.h_lsn = 0;
2342 iclog->ic_header.h_tail_lsn = 0;
2343}
2344
2345/*
2346 * Loop through all iclogs and mark all iclogs currently marked DIRTY as
2347 * ACTIVE after iclog I/O has completed.
2348 */
2349static void
2350xlog_state_activate_iclogs(
2351 struct xlog *log,
2352 int *iclogs_changed)
2353{
2354 struct xlog_in_core *iclog = log->l_iclog;
2355
2356 do {
2357 if (iclog->ic_state == XLOG_STATE_DIRTY)
2358 xlog_state_activate_iclog(iclog, iclogs_changed);
2359 /*
2360 * The ordering of marking iclogs ACTIVE must be maintained, so
2361 * an iclog doesn't become ACTIVE beyond one that is SYNCING.
2362 */
2363 else if (iclog->ic_state != XLOG_STATE_ACTIVE)
2364 break;
2365 } while ((iclog = iclog->ic_next) != log->l_iclog);
2366}
2367
2368static int
2369xlog_covered_state(
2370 int prev_state,
2371 int iclogs_changed)
2372{
2373 /*
2374 * We go to NEED for any non-covering writes. We go to NEED2 if we just
2375 * wrote the first covering record (DONE). We go to IDLE if we just
2376 * wrote the second covering record (DONE2) and remain in IDLE until a
2377 * non-covering write occurs.
2378 */
2379 switch (prev_state) {
2380 case XLOG_STATE_COVER_IDLE:
2381 if (iclogs_changed == 1)
2382 return XLOG_STATE_COVER_IDLE;
2383 fallthrough;
2384 case XLOG_STATE_COVER_NEED:
2385 case XLOG_STATE_COVER_NEED2:
2386 break;
2387 case XLOG_STATE_COVER_DONE:
2388 if (iclogs_changed == 1)
2389 return XLOG_STATE_COVER_NEED2;
2390 break;
2391 case XLOG_STATE_COVER_DONE2:
2392 if (iclogs_changed == 1)
2393 return XLOG_STATE_COVER_IDLE;
2394 break;
2395 default:
2396 ASSERT(0);
2397 }
2398
2399 return XLOG_STATE_COVER_NEED;
2400}
2401
2402STATIC void
2403xlog_state_clean_iclog(
2404 struct xlog *log,
2405 struct xlog_in_core *dirty_iclog)
2406{
2407 int iclogs_changed = 0;
2408
2409 trace_xlog_iclog_clean(dirty_iclog, _RET_IP_);
2410
2411 dirty_iclog->ic_state = XLOG_STATE_DIRTY;
2412
2413 xlog_state_activate_iclogs(log, &iclogs_changed);
2414 wake_up_all(&dirty_iclog->ic_force_wait);
2415
2416 if (iclogs_changed) {
2417 log->l_covered_state = xlog_covered_state(log->l_covered_state,
2418 iclogs_changed);
2419 }
2420}
2421
2422STATIC xfs_lsn_t
2423xlog_get_lowest_lsn(
2424 struct xlog *log)
2425{
2426 struct xlog_in_core *iclog = log->l_iclog;
2427 xfs_lsn_t lowest_lsn = 0, lsn;
2428
2429 do {
2430 if (iclog->ic_state == XLOG_STATE_ACTIVE ||
2431 iclog->ic_state == XLOG_STATE_DIRTY)
2432 continue;
2433
2434 lsn = be64_to_cpu(iclog->ic_header.h_lsn);
2435 if ((lsn && !lowest_lsn) || XFS_LSN_CMP(lsn, lowest_lsn) < 0)
2436 lowest_lsn = lsn;
2437 } while ((iclog = iclog->ic_next) != log->l_iclog);
2438
2439 return lowest_lsn;
2440}
2441
2442/*
2443 * Return true if we need to stop processing, false to continue to the next
2444 * iclog. The caller will need to run callbacks if the iclog is returned in the
2445 * XLOG_STATE_CALLBACK state.
2446 */
2447static bool
2448xlog_state_iodone_process_iclog(
2449 struct xlog *log,
2450 struct xlog_in_core *iclog)
2451{
2452 xfs_lsn_t lowest_lsn;
2453 xfs_lsn_t header_lsn;
2454
2455 switch (iclog->ic_state) {
2456 case XLOG_STATE_ACTIVE:
2457 case XLOG_STATE_DIRTY:
2458 /*
2459 * Skip all iclogs in the ACTIVE & DIRTY states:
2460 */
2461 return false;
2462 case XLOG_STATE_DONE_SYNC:
2463 /*
2464 * Now that we have an iclog that is in the DONE_SYNC state, do
2465 * one more check here to see if we have chased our tail around.
2466 * If this is not the lowest lsn iclog, then we will leave it
2467 * for another completion to process.
2468 */
2469 header_lsn = be64_to_cpu(iclog->ic_header.h_lsn);
2470 lowest_lsn = xlog_get_lowest_lsn(log);
2471 if (lowest_lsn && XFS_LSN_CMP(lowest_lsn, header_lsn) < 0)
2472 return false;
2473 /*
2474 * If there are no callbacks on this iclog, we can mark it clean
2475 * immediately and return. Otherwise we need to run the
2476 * callbacks.
2477 */
2478 if (list_empty(&iclog->ic_callbacks)) {
2479 xlog_state_clean_iclog(log, iclog);
2480 return false;
2481 }
2482 trace_xlog_iclog_callback(iclog, _RET_IP_);
2483 iclog->ic_state = XLOG_STATE_CALLBACK;
2484 return false;
2485 default:
2486 /*
2487 * Can only perform callbacks in order. Since this iclog is not
2488 * in the DONE_SYNC state, we skip the rest and just try to
2489 * clean up.
2490 */
2491 return true;
2492 }
2493}
2494
2495/*
2496 * Loop over all the iclogs, running attached callbacks on them. Return true if
2497 * we ran any callbacks, indicating that we dropped the icloglock. We don't need
2498 * to handle transient shutdown state here at all because
2499 * xlog_state_shutdown_callbacks() will be run to do the necessary shutdown
2500 * cleanup of the callbacks.
2501 */
2502static bool
2503xlog_state_do_iclog_callbacks(
2504 struct xlog *log)
2505 __releases(&log->l_icloglock)
2506 __acquires(&log->l_icloglock)
2507{
2508 struct xlog_in_core *first_iclog = log->l_iclog;
2509 struct xlog_in_core *iclog = first_iclog;
2510 bool ran_callback = false;
2511
2512 do {
2513 LIST_HEAD(cb_list);
2514
2515 if (xlog_state_iodone_process_iclog(log, iclog))
2516 break;
2517 if (iclog->ic_state != XLOG_STATE_CALLBACK) {
2518 iclog = iclog->ic_next;
2519 continue;
2520 }
2521 list_splice_init(&iclog->ic_callbacks, &cb_list);
2522 spin_unlock(&log->l_icloglock);
2523
2524 trace_xlog_iclog_callbacks_start(iclog, _RET_IP_);
2525 xlog_cil_process_committed(&cb_list);
2526 trace_xlog_iclog_callbacks_done(iclog, _RET_IP_);
2527 ran_callback = true;
2528
2529 spin_lock(&log->l_icloglock);
2530 xlog_state_clean_iclog(log, iclog);
2531 iclog = iclog->ic_next;
2532 } while (iclog != first_iclog);
2533
2534 return ran_callback;
2535}
2536
2537
2538/*
2539 * Loop running iclog completion callbacks until there are no more iclogs in a
2540 * state that can run callbacks.
2541 */
2542STATIC void
2543xlog_state_do_callback(
2544 struct xlog *log)
2545{
2546 int flushcnt = 0;
2547 int repeats = 0;
2548
2549 spin_lock(&log->l_icloglock);
2550 while (xlog_state_do_iclog_callbacks(log)) {
2551 if (xlog_is_shutdown(log))
2552 break;
2553
2554 if (++repeats > 5000) {
2555 flushcnt += repeats;
2556 repeats = 0;
2557 xfs_warn(log->l_mp,
2558 "%s: possible infinite loop (%d iterations)",
2559 __func__, flushcnt);
2560 }
2561 }
2562
2563 if (log->l_iclog->ic_state == XLOG_STATE_ACTIVE)
2564 wake_up_all(&log->l_flush_wait);
2565
2566 spin_unlock(&log->l_icloglock);
2567}
2568
2569
2570/*
2571 * Finish transitioning this iclog to the dirty state.
2572 *
2573 * Callbacks could take time, so they are done outside the scope of the
2574 * global state machine log lock.
2575 */
2576STATIC void
2577xlog_state_done_syncing(
2578 struct xlog_in_core *iclog)
2579{
2580 struct xlog *log = iclog->ic_log;
2581
2582 spin_lock(&log->l_icloglock);
2583 ASSERT(atomic_read(&iclog->ic_refcnt) == 0);
2584 trace_xlog_iclog_sync_done(iclog, _RET_IP_);
2585
2586 /*
2587 * If we got an error, either on the first buffer, or in the case of
2588 * split log writes, on the second, we shut down the file system and
2589 * no iclogs should ever be attempted to be written to disk again.
2590 */
2591 if (!xlog_is_shutdown(log)) {
2592 ASSERT(iclog->ic_state == XLOG_STATE_SYNCING);
2593 iclog->ic_state = XLOG_STATE_DONE_SYNC;
2594 }
2595
2596 /*
2597 * Someone could be sleeping prior to writing out the next
2598 * iclog buffer, we wake them all, one will get to do the
2599 * I/O, the others get to wait for the result.
2600 */
2601 wake_up_all(&iclog->ic_write_wait);
2602 spin_unlock(&log->l_icloglock);
2603 xlog_state_do_callback(log);
2604}
2605
2606/*
2607 * If the head of the in-core log ring is not (ACTIVE or DIRTY), then we must
2608 * sleep. We wait on the flush queue on the head iclog as that should be
2609 * the first iclog to complete flushing. Hence if all iclogs are syncing,
2610 * we will wait here and all new writes will sleep until a sync completes.
2611 *
2612 * The in-core logs are used in a circular fashion. They are not used
2613 * out-of-order even when an iclog past the head is free.
2614 *
2615 * return:
2616 * * log_offset where xlog_write() can start writing into the in-core
2617 * log's data space.
2618 * * in-core log pointer to which xlog_write() should write.
2619 * * boolean indicating this is a continued write to an in-core log.
2620 * If this is the last write, then the in-core log's offset field
2621 * needs to be incremented, depending on the amount of data which
2622 * is copied.
2623 */
2624STATIC int
2625xlog_state_get_iclog_space(
2626 struct xlog *log,
2627 int len,
2628 struct xlog_in_core **iclogp,
2629 struct xlog_ticket *ticket,
2630 int *logoffsetp)
2631{
2632 int log_offset;
2633 xlog_rec_header_t *head;
2634 xlog_in_core_t *iclog;
2635
2636restart:
2637 spin_lock(&log->l_icloglock);
2638 if (xlog_is_shutdown(log)) {
2639 spin_unlock(&log->l_icloglock);
2640 return -EIO;
2641 }
2642
2643 iclog = log->l_iclog;
2644 if (iclog->ic_state != XLOG_STATE_ACTIVE) {
2645 XFS_STATS_INC(log->l_mp, xs_log_noiclogs);
2646
2647 /* Wait for log writes to have flushed */
2648 xlog_wait(&log->l_flush_wait, &log->l_icloglock);
2649 goto restart;
2650 }
2651
2652 head = &iclog->ic_header;
2653
2654 atomic_inc(&iclog->ic_refcnt); /* prevents sync */
2655 log_offset = iclog->ic_offset;
2656
2657 trace_xlog_iclog_get_space(iclog, _RET_IP_);
2658
2659 /* On the 1st write to an iclog, figure out lsn. This works
2660 * if iclogs marked XLOG_STATE_WANT_SYNC always write out what they are
2661 * committing to. If the offset is set, that's how many blocks
2662 * must be written.
2663 */
2664 if (log_offset == 0) {
2665 ticket->t_curr_res -= log->l_iclog_hsize;
2666 head->h_cycle = cpu_to_be32(log->l_curr_cycle);
2667 head->h_lsn = cpu_to_be64(
2668 xlog_assign_lsn(log->l_curr_cycle, log->l_curr_block));
2669 ASSERT(log->l_curr_block >= 0);
2670 }
2671
2672 /* If there is enough room to write everything, then do it. Otherwise,
2673 * claim the rest of the region and make sure the XLOG_STATE_WANT_SYNC
2674 * bit is on, so this will get flushed out. Don't update ic_offset
2675 * until you know exactly how many bytes get copied. Therefore, wait
2676 * until later to update ic_offset.
2677 *
2678 * xlog_write() algorithm assumes that at least 2 xlog_op_header_t's
2679 * can fit into remaining data section.
2680 */
2681 if (iclog->ic_size - iclog->ic_offset < 2*sizeof(xlog_op_header_t)) {
2682 int error = 0;
2683
2684 xlog_state_switch_iclogs(log, iclog, iclog->ic_size);
2685
2686 /*
2687 * If we are the only one writing to this iclog, sync it to
2688 * disk. We need to do an atomic compare and decrement here to
2689 * avoid racing with concurrent atomic_dec_and_lock() calls in
2690 * xlog_state_release_iclog() when there is more than one
2691 * reference to the iclog.
2692 */
2693 if (!atomic_add_unless(&iclog->ic_refcnt, -1, 1))
2694 error = xlog_state_release_iclog(log, iclog, ticket);
2695 spin_unlock(&log->l_icloglock);
2696 if (error)
2697 return error;
2698 goto restart;
2699 }
2700
2701 /* Do we have enough room to write the full amount in the remainder
2702 * of this iclog? Or must we continue a write on the next iclog and
2703 * mark this iclog as completely taken? In the case where we switch
2704 * iclogs (to mark it taken), this particular iclog will release/sync
2705 * to disk in xlog_write().
2706 */
2707 if (len <= iclog->ic_size - iclog->ic_offset)
2708 iclog->ic_offset += len;
2709 else
2710 xlog_state_switch_iclogs(log, iclog, iclog->ic_size);
2711 *iclogp = iclog;
2712
2713 ASSERT(iclog->ic_offset <= iclog->ic_size);
2714 spin_unlock(&log->l_icloglock);
2715
2716 *logoffsetp = log_offset;
2717 return 0;
2718}
2719
2720/*
2721 * The first cnt-1 times a ticket goes through here we don't need to move the
2722 * grant write head because the permanent reservation has reserved cnt times the
2723 * unit amount. Release part of current permanent unit reservation and reset
2724 * current reservation to be one units worth. Also move grant reservation head
2725 * forward.
2726 */
2727void
2728xfs_log_ticket_regrant(
2729 struct xlog *log,
2730 struct xlog_ticket *ticket)
2731{
2732 trace_xfs_log_ticket_regrant(log, ticket);
2733
2734 if (ticket->t_cnt > 0)
2735 ticket->t_cnt--;
2736
2737 xlog_grant_sub_space(&log->l_reserve_head, ticket->t_curr_res);
2738 xlog_grant_sub_space(&log->l_write_head, ticket->t_curr_res);
2739 ticket->t_curr_res = ticket->t_unit_res;
2740
2741 trace_xfs_log_ticket_regrant_sub(log, ticket);
2742
2743 /* just return if we still have some of the pre-reserved space */
2744 if (!ticket->t_cnt) {
2745 xlog_grant_add_space(&log->l_reserve_head, ticket->t_unit_res);
2746 trace_xfs_log_ticket_regrant_exit(log, ticket);
2747
2748 ticket->t_curr_res = ticket->t_unit_res;
2749 }
2750
2751 xfs_log_ticket_put(ticket);
2752}
2753
2754/*
2755 * Give back the space left from a reservation.
2756 *
2757 * All the information we need to make a correct determination of space left
2758 * is present. For non-permanent reservations, things are quite easy. The
2759 * count should have been decremented to zero. We only need to deal with the
2760 * space remaining in the current reservation part of the ticket. If the
2761 * ticket contains a permanent reservation, there may be left over space which
2762 * needs to be released. A count of N means that N-1 refills of the current
2763 * reservation can be done before we need to ask for more space. The first
2764 * one goes to fill up the first current reservation. Once we run out of
2765 * space, the count will stay at zero and the only space remaining will be
2766 * in the current reservation field.
2767 */
2768void
2769xfs_log_ticket_ungrant(
2770 struct xlog *log,
2771 struct xlog_ticket *ticket)
2772{
2773 int bytes;
2774
2775 trace_xfs_log_ticket_ungrant(log, ticket);
2776
2777 if (ticket->t_cnt > 0)
2778 ticket->t_cnt--;
2779
2780 trace_xfs_log_ticket_ungrant_sub(log, ticket);
2781
2782 /*
2783 * If this is a permanent reservation ticket, we may be able to free
2784 * up more space based on the remaining count.
2785 */
2786 bytes = ticket->t_curr_res;
2787 if (ticket->t_cnt > 0) {
2788 ASSERT(ticket->t_flags & XLOG_TIC_PERM_RESERV);
2789 bytes += ticket->t_unit_res*ticket->t_cnt;
2790 }
2791
2792 xlog_grant_sub_space(&log->l_reserve_head, bytes);
2793 xlog_grant_sub_space(&log->l_write_head, bytes);
2794
2795 trace_xfs_log_ticket_ungrant_exit(log, ticket);
2796
2797 xfs_log_space_wake(log->l_mp);
2798 xfs_log_ticket_put(ticket);
2799}
2800
2801/*
2802 * This routine will mark the current iclog in the ring as WANT_SYNC and move
2803 * the current iclog pointer to the next iclog in the ring.
2804 */
2805void
2806xlog_state_switch_iclogs(
2807 struct xlog *log,
2808 struct xlog_in_core *iclog,
2809 int eventual_size)
2810{
2811 ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE);
2812 assert_spin_locked(&log->l_icloglock);
2813 trace_xlog_iclog_switch(iclog, _RET_IP_);
2814
2815 if (!eventual_size)
2816 eventual_size = iclog->ic_offset;
2817 iclog->ic_state = XLOG_STATE_WANT_SYNC;
2818 iclog->ic_header.h_prev_block = cpu_to_be32(log->l_prev_block);
2819 log->l_prev_block = log->l_curr_block;
2820 log->l_prev_cycle = log->l_curr_cycle;
2821
2822 /* roll log?: ic_offset changed later */
2823 log->l_curr_block += BTOBB(eventual_size)+BTOBB(log->l_iclog_hsize);
2824
2825 /* Round up to next log-sunit */
2826 if (log->l_iclog_roundoff > BBSIZE) {
2827 uint32_t sunit_bb = BTOBB(log->l_iclog_roundoff);
2828 log->l_curr_block = roundup(log->l_curr_block, sunit_bb);
2829 }
2830
2831 if (log->l_curr_block >= log->l_logBBsize) {
2832 /*
2833 * Rewind the current block before the cycle is bumped to make
2834 * sure that the combined LSN never transiently moves forward
2835 * when the log wraps to the next cycle. This is to support the
2836 * unlocked sample of these fields from xlog_valid_lsn(). Most
2837 * other cases should acquire l_icloglock.
2838 */
2839 log->l_curr_block -= log->l_logBBsize;
2840 ASSERT(log->l_curr_block >= 0);
2841 smp_wmb();
2842 log->l_curr_cycle++;
2843 if (log->l_curr_cycle == XLOG_HEADER_MAGIC_NUM)
2844 log->l_curr_cycle++;
2845 }
2846 ASSERT(iclog == log->l_iclog);
2847 log->l_iclog = iclog->ic_next;
2848}
2849
2850/*
2851 * Force the iclog to disk and check if the iclog has been completed before
2852 * xlog_force_iclog() returns. This can happen on synchronous (e.g.
2853 * pmem) or fast async storage because we drop the icloglock to issue the IO.
2854 * If completion has already occurred, tell the caller so that it can avoid an
2855 * unnecessary wait on the iclog.
2856 */
2857static int
2858xlog_force_and_check_iclog(
2859 struct xlog_in_core *iclog,
2860 bool *completed)
2861{
2862 xfs_lsn_t lsn = be64_to_cpu(iclog->ic_header.h_lsn);
2863 int error;
2864
2865 *completed = false;
2866 error = xlog_force_iclog(iclog);
2867 if (error)
2868 return error;
2869
2870 /*
2871 * If the iclog has already been completed and reused the header LSN
2872 * will have been rewritten by completion
2873 */
2874 if (be64_to_cpu(iclog->ic_header.h_lsn) != lsn)
2875 *completed = true;
2876 return 0;
2877}
2878
2879/*
2880 * Write out all data in the in-core log as of this exact moment in time.
2881 *
2882 * Data may be written to the in-core log during this call. However,
2883 * we don't guarantee this data will be written out. A change from past
2884 * implementation means this routine will *not* write out zero length LRs.
2885 *
2886 * Basically, we try and perform an intelligent scan of the in-core logs.
2887 * If we determine there is no flushable data, we just return. There is no
2888 * flushable data if:
2889 *
2890 * 1. the current iclog is active and has no data; the previous iclog
2891 * is in the active or dirty state.
2892 * 2. the current iclog is drity, and the previous iclog is in the
2893 * active or dirty state.
2894 *
2895 * We may sleep if:
2896 *
2897 * 1. the current iclog is not in the active nor dirty state.
2898 * 2. the current iclog dirty, and the previous iclog is not in the
2899 * active nor dirty state.
2900 * 3. the current iclog is active, and there is another thread writing
2901 * to this particular iclog.
2902 * 4. a) the current iclog is active and has no other writers
2903 * b) when we return from flushing out this iclog, it is still
2904 * not in the active nor dirty state.
2905 */
2906int
2907xfs_log_force(
2908 struct xfs_mount *mp,
2909 uint flags)
2910{
2911 struct xlog *log = mp->m_log;
2912 struct xlog_in_core *iclog;
2913
2914 XFS_STATS_INC(mp, xs_log_force);
2915 trace_xfs_log_force(mp, 0, _RET_IP_);
2916
2917 xlog_cil_force(log);
2918
2919 spin_lock(&log->l_icloglock);
2920 if (xlog_is_shutdown(log))
2921 goto out_error;
2922
2923 iclog = log->l_iclog;
2924 trace_xlog_iclog_force(iclog, _RET_IP_);
2925
2926 if (iclog->ic_state == XLOG_STATE_DIRTY ||
2927 (iclog->ic_state == XLOG_STATE_ACTIVE &&
2928 atomic_read(&iclog->ic_refcnt) == 0 && iclog->ic_offset == 0)) {
2929 /*
2930 * If the head is dirty or (active and empty), then we need to
2931 * look at the previous iclog.
2932 *
2933 * If the previous iclog is active or dirty we are done. There
2934 * is nothing to sync out. Otherwise, we attach ourselves to the
2935 * previous iclog and go to sleep.
2936 */
2937 iclog = iclog->ic_prev;
2938 } else if (iclog->ic_state == XLOG_STATE_ACTIVE) {
2939 if (atomic_read(&iclog->ic_refcnt) == 0) {
2940 /* We have exclusive access to this iclog. */
2941 bool completed;
2942
2943 if (xlog_force_and_check_iclog(iclog, &completed))
2944 goto out_error;
2945
2946 if (completed)
2947 goto out_unlock;
2948 } else {
2949 /*
2950 * Someone else is still writing to this iclog, so we
2951 * need to ensure that when they release the iclog it
2952 * gets synced immediately as we may be waiting on it.
2953 */
2954 xlog_state_switch_iclogs(log, iclog, 0);
2955 }
2956 }
2957
2958 /*
2959 * The iclog we are about to wait on may contain the checkpoint pushed
2960 * by the above xlog_cil_force() call, but it may not have been pushed
2961 * to disk yet. Like the ACTIVE case above, we need to make sure caches
2962 * are flushed when this iclog is written.
2963 */
2964 if (iclog->ic_state == XLOG_STATE_WANT_SYNC)
2965 iclog->ic_flags |= XLOG_ICL_NEED_FLUSH | XLOG_ICL_NEED_FUA;
2966
2967 if (flags & XFS_LOG_SYNC)
2968 return xlog_wait_on_iclog(iclog);
2969out_unlock:
2970 spin_unlock(&log->l_icloglock);
2971 return 0;
2972out_error:
2973 spin_unlock(&log->l_icloglock);
2974 return -EIO;
2975}
2976
2977/*
2978 * Force the log to a specific LSN.
2979 *
2980 * If an iclog with that lsn can be found:
2981 * If it is in the DIRTY state, just return.
2982 * If it is in the ACTIVE state, move the in-core log into the WANT_SYNC
2983 * state and go to sleep or return.
2984 * If it is in any other state, go to sleep or return.
2985 *
2986 * Synchronous forces are implemented with a wait queue. All callers trying
2987 * to force a given lsn to disk must wait on the queue attached to the
2988 * specific in-core log. When given in-core log finally completes its write
2989 * to disk, that thread will wake up all threads waiting on the queue.
2990 */
2991static int
2992xlog_force_lsn(
2993 struct xlog *log,
2994 xfs_lsn_t lsn,
2995 uint flags,
2996 int *log_flushed,
2997 bool already_slept)
2998{
2999 struct xlog_in_core *iclog;
3000 bool completed;
3001
3002 spin_lock(&log->l_icloglock);
3003 if (xlog_is_shutdown(log))
3004 goto out_error;
3005
3006 iclog = log->l_iclog;
3007 while (be64_to_cpu(iclog->ic_header.h_lsn) != lsn) {
3008 trace_xlog_iclog_force_lsn(iclog, _RET_IP_);
3009 iclog = iclog->ic_next;
3010 if (iclog == log->l_iclog)
3011 goto out_unlock;
3012 }
3013
3014 switch (iclog->ic_state) {
3015 case XLOG_STATE_ACTIVE:
3016 /*
3017 * We sleep here if we haven't already slept (e.g. this is the
3018 * first time we've looked at the correct iclog buf) and the
3019 * buffer before us is going to be sync'ed. The reason for this
3020 * is that if we are doing sync transactions here, by waiting
3021 * for the previous I/O to complete, we can allow a few more
3022 * transactions into this iclog before we close it down.
3023 *
3024 * Otherwise, we mark the buffer WANT_SYNC, and bump up the
3025 * refcnt so we can release the log (which drops the ref count).
3026 * The state switch keeps new transaction commits from using
3027 * this buffer. When the current commits finish writing into
3028 * the buffer, the refcount will drop to zero and the buffer
3029 * will go out then.
3030 */
3031 if (!already_slept &&
3032 (iclog->ic_prev->ic_state == XLOG_STATE_WANT_SYNC ||
3033 iclog->ic_prev->ic_state == XLOG_STATE_SYNCING)) {
3034 xlog_wait(&iclog->ic_prev->ic_write_wait,
3035 &log->l_icloglock);
3036 return -EAGAIN;
3037 }
3038 if (xlog_force_and_check_iclog(iclog, &completed))
3039 goto out_error;
3040 if (log_flushed)
3041 *log_flushed = 1;
3042 if (completed)
3043 goto out_unlock;
3044 break;
3045 case XLOG_STATE_WANT_SYNC:
3046 /*
3047 * This iclog may contain the checkpoint pushed by the
3048 * xlog_cil_force_seq() call, but there are other writers still
3049 * accessing it so it hasn't been pushed to disk yet. Like the
3050 * ACTIVE case above, we need to make sure caches are flushed
3051 * when this iclog is written.
3052 */
3053 iclog->ic_flags |= XLOG_ICL_NEED_FLUSH | XLOG_ICL_NEED_FUA;
3054 break;
3055 default:
3056 /*
3057 * The entire checkpoint was written by the CIL force and is on
3058 * its way to disk already. It will be stable when it
3059 * completes, so we don't need to manipulate caches here at all.
3060 * We just need to wait for completion if necessary.
3061 */
3062 break;
3063 }
3064
3065 if (flags & XFS_LOG_SYNC)
3066 return xlog_wait_on_iclog(iclog);
3067out_unlock:
3068 spin_unlock(&log->l_icloglock);
3069 return 0;
3070out_error:
3071 spin_unlock(&log->l_icloglock);
3072 return -EIO;
3073}
3074
3075/*
3076 * Force the log to a specific checkpoint sequence.
3077 *
3078 * First force the CIL so that all the required changes have been flushed to the
3079 * iclogs. If the CIL force completed it will return a commit LSN that indicates
3080 * the iclog that needs to be flushed to stable storage. If the caller needs
3081 * a synchronous log force, we will wait on the iclog with the LSN returned by
3082 * xlog_cil_force_seq() to be completed.
3083 */
3084int
3085xfs_log_force_seq(
3086 struct xfs_mount *mp,
3087 xfs_csn_t seq,
3088 uint flags,
3089 int *log_flushed)
3090{
3091 struct xlog *log = mp->m_log;
3092 xfs_lsn_t lsn;
3093 int ret;
3094 ASSERT(seq != 0);
3095
3096 XFS_STATS_INC(mp, xs_log_force);
3097 trace_xfs_log_force(mp, seq, _RET_IP_);
3098
3099 lsn = xlog_cil_force_seq(log, seq);
3100 if (lsn == NULLCOMMITLSN)
3101 return 0;
3102
3103 ret = xlog_force_lsn(log, lsn, flags, log_flushed, false);
3104 if (ret == -EAGAIN) {
3105 XFS_STATS_INC(mp, xs_log_force_sleep);
3106 ret = xlog_force_lsn(log, lsn, flags, log_flushed, true);
3107 }
3108 return ret;
3109}
3110
3111/*
3112 * Free a used ticket when its refcount falls to zero.
3113 */
3114void
3115xfs_log_ticket_put(
3116 xlog_ticket_t *ticket)
3117{
3118 ASSERT(atomic_read(&ticket->t_ref) > 0);
3119 if (atomic_dec_and_test(&ticket->t_ref))
3120 kmem_cache_free(xfs_log_ticket_cache, ticket);
3121}
3122
3123xlog_ticket_t *
3124xfs_log_ticket_get(
3125 xlog_ticket_t *ticket)
3126{
3127 ASSERT(atomic_read(&ticket->t_ref) > 0);
3128 atomic_inc(&ticket->t_ref);
3129 return ticket;
3130}
3131
3132/*
3133 * Figure out the total log space unit (in bytes) that would be
3134 * required for a log ticket.
3135 */
3136static int
3137xlog_calc_unit_res(
3138 struct xlog *log,
3139 int unit_bytes,
3140 int *niclogs)
3141{
3142 int iclog_space;
3143 uint num_headers;
3144
3145 /*
3146 * Permanent reservations have up to 'cnt'-1 active log operations
3147 * in the log. A unit in this case is the amount of space for one
3148 * of these log operations. Normal reservations have a cnt of 1
3149 * and their unit amount is the total amount of space required.
3150 *
3151 * The following lines of code account for non-transaction data
3152 * which occupy space in the on-disk log.
3153 *
3154 * Normal form of a transaction is:
3155 * <oph><trans-hdr><start-oph><reg1-oph><reg1><reg2-oph>...<commit-oph>
3156 * and then there are LR hdrs, split-recs and roundoff at end of syncs.
3157 *
3158 * We need to account for all the leadup data and trailer data
3159 * around the transaction data.
3160 * And then we need to account for the worst case in terms of using
3161 * more space.
3162 * The worst case will happen if:
3163 * - the placement of the transaction happens to be such that the
3164 * roundoff is at its maximum
3165 * - the transaction data is synced before the commit record is synced
3166 * i.e. <transaction-data><roundoff> | <commit-rec><roundoff>
3167 * Therefore the commit record is in its own Log Record.
3168 * This can happen as the commit record is called with its
3169 * own region to xlog_write().
3170 * This then means that in the worst case, roundoff can happen for
3171 * the commit-rec as well.
3172 * The commit-rec is smaller than padding in this scenario and so it is
3173 * not added separately.
3174 */
3175
3176 /* for trans header */
3177 unit_bytes += sizeof(xlog_op_header_t);
3178 unit_bytes += sizeof(xfs_trans_header_t);
3179
3180 /* for start-rec */
3181 unit_bytes += sizeof(xlog_op_header_t);
3182
3183 /*
3184 * for LR headers - the space for data in an iclog is the size minus
3185 * the space used for the headers. If we use the iclog size, then we
3186 * undercalculate the number of headers required.
3187 *
3188 * Furthermore - the addition of op headers for split-recs might
3189 * increase the space required enough to require more log and op
3190 * headers, so take that into account too.
3191 *
3192 * IMPORTANT: This reservation makes the assumption that if this
3193 * transaction is the first in an iclog and hence has the LR headers
3194 * accounted to it, then the remaining space in the iclog is
3195 * exclusively for this transaction. i.e. if the transaction is larger
3196 * than the iclog, it will be the only thing in that iclog.
3197 * Fundamentally, this means we must pass the entire log vector to
3198 * xlog_write to guarantee this.
3199 */
3200 iclog_space = log->l_iclog_size - log->l_iclog_hsize;
3201 num_headers = howmany(unit_bytes, iclog_space);
3202
3203 /* for split-recs - ophdrs added when data split over LRs */
3204 unit_bytes += sizeof(xlog_op_header_t) * num_headers;
3205
3206 /* add extra header reservations if we overrun */
3207 while (!num_headers ||
3208 howmany(unit_bytes, iclog_space) > num_headers) {
3209 unit_bytes += sizeof(xlog_op_header_t);
3210 num_headers++;
3211 }
3212 unit_bytes += log->l_iclog_hsize * num_headers;
3213
3214 /* for commit-rec LR header - note: padding will subsume the ophdr */
3215 unit_bytes += log->l_iclog_hsize;
3216
3217 /* roundoff padding for transaction data and one for commit record */
3218 unit_bytes += 2 * log->l_iclog_roundoff;
3219
3220 if (niclogs)
3221 *niclogs = num_headers;
3222 return unit_bytes;
3223}
3224
3225int
3226xfs_log_calc_unit_res(
3227 struct xfs_mount *mp,
3228 int unit_bytes)
3229{
3230 return xlog_calc_unit_res(mp->m_log, unit_bytes, NULL);
3231}
3232
3233/*
3234 * Allocate and initialise a new log ticket.
3235 */
3236struct xlog_ticket *
3237xlog_ticket_alloc(
3238 struct xlog *log,
3239 int unit_bytes,
3240 int cnt,
3241 bool permanent)
3242{
3243 struct xlog_ticket *tic;
3244 int unit_res;
3245
3246 tic = kmem_cache_zalloc(xfs_log_ticket_cache,
3247 GFP_KERNEL | __GFP_NOFAIL);
3248
3249 unit_res = xlog_calc_unit_res(log, unit_bytes, &tic->t_iclog_hdrs);
3250
3251 atomic_set(&tic->t_ref, 1);
3252 tic->t_task = current;
3253 INIT_LIST_HEAD(&tic->t_queue);
3254 tic->t_unit_res = unit_res;
3255 tic->t_curr_res = unit_res;
3256 tic->t_cnt = cnt;
3257 tic->t_ocnt = cnt;
3258 tic->t_tid = get_random_u32();
3259 if (permanent)
3260 tic->t_flags |= XLOG_TIC_PERM_RESERV;
3261
3262 return tic;
3263}
3264
3265#if defined(DEBUG)
3266static void
3267xlog_verify_dump_tail(
3268 struct xlog *log,
3269 struct xlog_in_core *iclog)
3270{
3271 xfs_alert(log->l_mp,
3272"ran out of log space tail 0x%llx/0x%llx, head lsn 0x%llx, head 0x%x/0x%x, prev head 0x%x/0x%x",
3273 iclog ? be64_to_cpu(iclog->ic_header.h_tail_lsn) : -1,
3274 atomic64_read(&log->l_tail_lsn),
3275 log->l_ailp->ail_head_lsn,
3276 log->l_curr_cycle, log->l_curr_block,
3277 log->l_prev_cycle, log->l_prev_block);
3278 xfs_alert(log->l_mp,
3279"write grant 0x%llx, reserve grant 0x%llx, tail_space 0x%llx, size 0x%x, iclog flags 0x%x",
3280 atomic64_read(&log->l_write_head.grant),
3281 atomic64_read(&log->l_reserve_head.grant),
3282 log->l_tail_space, log->l_logsize,
3283 iclog ? iclog->ic_flags : -1);
3284}
3285
3286/* Check if the new iclog will fit in the log. */
3287STATIC void
3288xlog_verify_tail_lsn(
3289 struct xlog *log,
3290 struct xlog_in_core *iclog)
3291{
3292 xfs_lsn_t tail_lsn = be64_to_cpu(iclog->ic_header.h_tail_lsn);
3293 int blocks;
3294
3295 if (CYCLE_LSN(tail_lsn) == log->l_prev_cycle) {
3296 blocks = log->l_logBBsize -
3297 (log->l_prev_block - BLOCK_LSN(tail_lsn));
3298 if (blocks < BTOBB(iclog->ic_offset) +
3299 BTOBB(log->l_iclog_hsize)) {
3300 xfs_emerg(log->l_mp,
3301 "%s: ran out of log space", __func__);
3302 xlog_verify_dump_tail(log, iclog);
3303 }
3304 return;
3305 }
3306
3307 if (CYCLE_LSN(tail_lsn) + 1 != log->l_prev_cycle) {
3308 xfs_emerg(log->l_mp, "%s: head has wrapped tail.", __func__);
3309 xlog_verify_dump_tail(log, iclog);
3310 return;
3311 }
3312 if (BLOCK_LSN(tail_lsn) == log->l_prev_block) {
3313 xfs_emerg(log->l_mp, "%s: tail wrapped", __func__);
3314 xlog_verify_dump_tail(log, iclog);
3315 return;
3316 }
3317
3318 blocks = BLOCK_LSN(tail_lsn) - log->l_prev_block;
3319 if (blocks < BTOBB(iclog->ic_offset) + 1) {
3320 xfs_emerg(log->l_mp, "%s: ran out of iclog space", __func__);
3321 xlog_verify_dump_tail(log, iclog);
3322 }
3323}
3324
3325/*
3326 * Perform a number of checks on the iclog before writing to disk.
3327 *
3328 * 1. Make sure the iclogs are still circular
3329 * 2. Make sure we have a good magic number
3330 * 3. Make sure we don't have magic numbers in the data
3331 * 4. Check fields of each log operation header for:
3332 * A. Valid client identifier
3333 * B. tid ptr value falls in valid ptr space (user space code)
3334 * C. Length in log record header is correct according to the
3335 * individual operation headers within record.
3336 * 5. When a bwrite will occur within 5 blocks of the front of the physical
3337 * log, check the preceding blocks of the physical log to make sure all
3338 * the cycle numbers agree with the current cycle number.
3339 */
3340STATIC void
3341xlog_verify_iclog(
3342 struct xlog *log,
3343 struct xlog_in_core *iclog,
3344 int count)
3345{
3346 xlog_op_header_t *ophead;
3347 xlog_in_core_t *icptr;
3348 xlog_in_core_2_t *xhdr;
3349 void *base_ptr, *ptr, *p;
3350 ptrdiff_t field_offset;
3351 uint8_t clientid;
3352 int len, i, j, k, op_len;
3353 int idx;
3354
3355 /* check validity of iclog pointers */
3356 spin_lock(&log->l_icloglock);
3357 icptr = log->l_iclog;
3358 for (i = 0; i < log->l_iclog_bufs; i++, icptr = icptr->ic_next)
3359 ASSERT(icptr);
3360
3361 if (icptr != log->l_iclog)
3362 xfs_emerg(log->l_mp, "%s: corrupt iclog ring", __func__);
3363 spin_unlock(&log->l_icloglock);
3364
3365 /* check log magic numbers */
3366 if (iclog->ic_header.h_magicno != cpu_to_be32(XLOG_HEADER_MAGIC_NUM))
3367 xfs_emerg(log->l_mp, "%s: invalid magic num", __func__);
3368
3369 base_ptr = ptr = &iclog->ic_header;
3370 p = &iclog->ic_header;
3371 for (ptr += BBSIZE; ptr < base_ptr + count; ptr += BBSIZE) {
3372 if (*(__be32 *)ptr == cpu_to_be32(XLOG_HEADER_MAGIC_NUM))
3373 xfs_emerg(log->l_mp, "%s: unexpected magic num",
3374 __func__);
3375 }
3376
3377 /* check fields */
3378 len = be32_to_cpu(iclog->ic_header.h_num_logops);
3379 base_ptr = ptr = iclog->ic_datap;
3380 ophead = ptr;
3381 xhdr = iclog->ic_data;
3382 for (i = 0; i < len; i++) {
3383 ophead = ptr;
3384
3385 /* clientid is only 1 byte */
3386 p = &ophead->oh_clientid;
3387 field_offset = p - base_ptr;
3388 if (field_offset & 0x1ff) {
3389 clientid = ophead->oh_clientid;
3390 } else {
3391 idx = BTOBBT((void *)&ophead->oh_clientid - iclog->ic_datap);
3392 if (idx >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE)) {
3393 j = idx / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3394 k = idx % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3395 clientid = xlog_get_client_id(
3396 xhdr[j].hic_xheader.xh_cycle_data[k]);
3397 } else {
3398 clientid = xlog_get_client_id(
3399 iclog->ic_header.h_cycle_data[idx]);
3400 }
3401 }
3402 if (clientid != XFS_TRANSACTION && clientid != XFS_LOG) {
3403 xfs_warn(log->l_mp,
3404 "%s: op %d invalid clientid %d op "PTR_FMT" offset 0x%lx",
3405 __func__, i, clientid, ophead,
3406 (unsigned long)field_offset);
3407 }
3408
3409 /* check length */
3410 p = &ophead->oh_len;
3411 field_offset = p - base_ptr;
3412 if (field_offset & 0x1ff) {
3413 op_len = be32_to_cpu(ophead->oh_len);
3414 } else {
3415 idx = BTOBBT((void *)&ophead->oh_len - iclog->ic_datap);
3416 if (idx >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE)) {
3417 j = idx / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3418 k = idx % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3419 op_len = be32_to_cpu(xhdr[j].hic_xheader.xh_cycle_data[k]);
3420 } else {
3421 op_len = be32_to_cpu(iclog->ic_header.h_cycle_data[idx]);
3422 }
3423 }
3424 ptr += sizeof(xlog_op_header_t) + op_len;
3425 }
3426}
3427#endif
3428
3429/*
3430 * Perform a forced shutdown on the log.
3431 *
3432 * This can be called from low level log code to trigger a shutdown, or from the
3433 * high level mount shutdown code when the mount shuts down.
3434 *
3435 * Our main objectives here are to make sure that:
3436 * a. if the shutdown was not due to a log IO error, flush the logs to
3437 * disk. Anything modified after this is ignored.
3438 * b. the log gets atomically marked 'XLOG_IO_ERROR' for all interested
3439 * parties to find out. Nothing new gets queued after this is done.
3440 * c. Tasks sleeping on log reservations, pinned objects and
3441 * other resources get woken up.
3442 * d. The mount is also marked as shut down so that log triggered shutdowns
3443 * still behave the same as if they called xfs_forced_shutdown().
3444 *
3445 * Return true if the shutdown cause was a log IO error and we actually shut the
3446 * log down.
3447 */
3448bool
3449xlog_force_shutdown(
3450 struct xlog *log,
3451 uint32_t shutdown_flags)
3452{
3453 bool log_error = (shutdown_flags & SHUTDOWN_LOG_IO_ERROR);
3454
3455 if (!log)
3456 return false;
3457
3458 /*
3459 * Ensure that there is only ever one log shutdown being processed.
3460 * If we allow the log force below on a second pass after shutting
3461 * down the log, we risk deadlocking the CIL push as it may require
3462 * locks on objects the current shutdown context holds (e.g. taking
3463 * buffer locks to abort buffers on last unpin of buf log items).
3464 */
3465 if (test_and_set_bit(XLOG_SHUTDOWN_STARTED, &log->l_opstate))
3466 return false;
3467
3468 /*
3469 * Flush all the completed transactions to disk before marking the log
3470 * being shut down. We need to do this first as shutting down the log
3471 * before the force will prevent the log force from flushing the iclogs
3472 * to disk.
3473 *
3474 * When we are in recovery, there are no transactions to flush, and
3475 * we don't want to touch the log because we don't want to perturb the
3476 * current head/tail for future recovery attempts. Hence we need to
3477 * avoid a log force in this case.
3478 *
3479 * If we are shutting down due to a log IO error, then we must avoid
3480 * trying to write the log as that may just result in more IO errors and
3481 * an endless shutdown/force loop.
3482 */
3483 if (!log_error && !xlog_in_recovery(log))
3484 xfs_log_force(log->l_mp, XFS_LOG_SYNC);
3485
3486 /*
3487 * Atomically set the shutdown state. If the shutdown state is already
3488 * set, there someone else is performing the shutdown and so we are done
3489 * here. This should never happen because we should only ever get called
3490 * once by the first shutdown caller.
3491 *
3492 * Much of the log state machine transitions assume that shutdown state
3493 * cannot change once they hold the log->l_icloglock. Hence we need to
3494 * hold that lock here, even though we use the atomic test_and_set_bit()
3495 * operation to set the shutdown state.
3496 */
3497 spin_lock(&log->l_icloglock);
3498 if (test_and_set_bit(XLOG_IO_ERROR, &log->l_opstate)) {
3499 spin_unlock(&log->l_icloglock);
3500 ASSERT(0);
3501 return false;
3502 }
3503 spin_unlock(&log->l_icloglock);
3504
3505 /*
3506 * If this log shutdown also sets the mount shutdown state, issue a
3507 * shutdown warning message.
3508 */
3509 if (!xfs_set_shutdown(log->l_mp)) {
3510 xfs_alert_tag(log->l_mp, XFS_PTAG_SHUTDOWN_LOGERROR,
3511"Filesystem has been shut down due to log error (0x%x).",
3512 shutdown_flags);
3513 xfs_alert(log->l_mp,
3514"Please unmount the filesystem and rectify the problem(s).");
3515 if (xfs_error_level >= XFS_ERRLEVEL_HIGH)
3516 xfs_stack_trace();
3517 }
3518
3519 /*
3520 * We don't want anybody waiting for log reservations after this. That
3521 * means we have to wake up everybody queued up on reserveq as well as
3522 * writeq. In addition, we make sure in xlog_{re}grant_log_space that
3523 * we don't enqueue anything once the SHUTDOWN flag is set, and this
3524 * action is protected by the grant locks.
3525 */
3526 xlog_grant_head_wake_all(&log->l_reserve_head);
3527 xlog_grant_head_wake_all(&log->l_write_head);
3528
3529 /*
3530 * Wake up everybody waiting on xfs_log_force. Wake the CIL push first
3531 * as if the log writes were completed. The abort handling in the log
3532 * item committed callback functions will do this again under lock to
3533 * avoid races.
3534 */
3535 spin_lock(&log->l_cilp->xc_push_lock);
3536 wake_up_all(&log->l_cilp->xc_start_wait);
3537 wake_up_all(&log->l_cilp->xc_commit_wait);
3538 spin_unlock(&log->l_cilp->xc_push_lock);
3539
3540 spin_lock(&log->l_icloglock);
3541 xlog_state_shutdown_callbacks(log);
3542 spin_unlock(&log->l_icloglock);
3543
3544 wake_up_var(&log->l_opstate);
3545 return log_error;
3546}
3547
3548STATIC int
3549xlog_iclogs_empty(
3550 struct xlog *log)
3551{
3552 xlog_in_core_t *iclog;
3553
3554 iclog = log->l_iclog;
3555 do {
3556 /* endianness does not matter here, zero is zero in
3557 * any language.
3558 */
3559 if (iclog->ic_header.h_num_logops)
3560 return 0;
3561 iclog = iclog->ic_next;
3562 } while (iclog != log->l_iclog);
3563 return 1;
3564}
3565
3566/*
3567 * Verify that an LSN stamped into a piece of metadata is valid. This is
3568 * intended for use in read verifiers on v5 superblocks.
3569 */
3570bool
3571xfs_log_check_lsn(
3572 struct xfs_mount *mp,
3573 xfs_lsn_t lsn)
3574{
3575 struct xlog *log = mp->m_log;
3576 bool valid;
3577
3578 /*
3579 * norecovery mode skips mount-time log processing and unconditionally
3580 * resets the in-core LSN. We can't validate in this mode, but
3581 * modifications are not allowed anyways so just return true.
3582 */
3583 if (xfs_has_norecovery(mp))
3584 return true;
3585
3586 /*
3587 * Some metadata LSNs are initialized to NULL (e.g., the agfl). This is
3588 * handled by recovery and thus safe to ignore here.
3589 */
3590 if (lsn == NULLCOMMITLSN)
3591 return true;
3592
3593 valid = xlog_valid_lsn(mp->m_log, lsn);
3594
3595 /* warn the user about what's gone wrong before verifier failure */
3596 if (!valid) {
3597 spin_lock(&log->l_icloglock);
3598 xfs_warn(mp,
3599"Corruption warning: Metadata has LSN (%d:%d) ahead of current LSN (%d:%d). "
3600"Please unmount and run xfs_repair (>= v4.3) to resolve.",
3601 CYCLE_LSN(lsn), BLOCK_LSN(lsn),
3602 log->l_curr_cycle, log->l_curr_block);
3603 spin_unlock(&log->l_icloglock);
3604 }
3605
3606 return valid;
3607}