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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_types.h"
21#include "xfs_log.h"
22#include "xfs_trans.h"
23#include "xfs_sb.h"
24#include "xfs_ag.h"
25#include "xfs_mount.h"
26#include "xfs_error.h"
27#include "xfs_log_priv.h"
28#include "xfs_buf_item.h"
29#include "xfs_bmap_btree.h"
30#include "xfs_alloc_btree.h"
31#include "xfs_ialloc_btree.h"
32#include "xfs_log_recover.h"
33#include "xfs_trans_priv.h"
34#include "xfs_dinode.h"
35#include "xfs_inode.h"
36#include "xfs_trace.h"
37
38kmem_zone_t *xfs_log_ticket_zone;
39
40/* Local miscellaneous function prototypes */
41STATIC int
42xlog_commit_record(
43 struct xlog *log,
44 struct xlog_ticket *ticket,
45 struct xlog_in_core **iclog,
46 xfs_lsn_t *commitlsnp);
47
48STATIC xlog_t * xlog_alloc_log(xfs_mount_t *mp,
49 xfs_buftarg_t *log_target,
50 xfs_daddr_t blk_offset,
51 int num_bblks);
52STATIC int
53xlog_space_left(
54 struct xlog *log,
55 atomic64_t *head);
56STATIC int xlog_sync(xlog_t *log, xlog_in_core_t *iclog);
57STATIC void xlog_dealloc_log(xlog_t *log);
58
59/* local state machine functions */
60STATIC void xlog_state_done_syncing(xlog_in_core_t *iclog, int);
61STATIC void xlog_state_do_callback(xlog_t *log,int aborted, xlog_in_core_t *iclog);
62STATIC int xlog_state_get_iclog_space(xlog_t *log,
63 int len,
64 xlog_in_core_t **iclog,
65 xlog_ticket_t *ticket,
66 int *continued_write,
67 int *logoffsetp);
68STATIC int xlog_state_release_iclog(xlog_t *log,
69 xlog_in_core_t *iclog);
70STATIC void xlog_state_switch_iclogs(xlog_t *log,
71 xlog_in_core_t *iclog,
72 int eventual_size);
73STATIC void xlog_state_want_sync(xlog_t *log, xlog_in_core_t *iclog);
74
75STATIC void
76xlog_grant_push_ail(
77 struct xlog *log,
78 int need_bytes);
79STATIC void xlog_regrant_reserve_log_space(xlog_t *log,
80 xlog_ticket_t *ticket);
81STATIC void xlog_ungrant_log_space(xlog_t *log,
82 xlog_ticket_t *ticket);
83
84#if defined(DEBUG)
85STATIC void xlog_verify_dest_ptr(xlog_t *log, char *ptr);
86STATIC void
87xlog_verify_grant_tail(
88 struct xlog *log);
89STATIC void xlog_verify_iclog(xlog_t *log, xlog_in_core_t *iclog,
90 int count, boolean_t syncing);
91STATIC void xlog_verify_tail_lsn(xlog_t *log, xlog_in_core_t *iclog,
92 xfs_lsn_t tail_lsn);
93#else
94#define xlog_verify_dest_ptr(a,b)
95#define xlog_verify_grant_tail(a)
96#define xlog_verify_iclog(a,b,c,d)
97#define xlog_verify_tail_lsn(a,b,c)
98#endif
99
100STATIC int xlog_iclogs_empty(xlog_t *log);
101
102static void
103xlog_grant_sub_space(
104 struct xlog *log,
105 atomic64_t *head,
106 int bytes)
107{
108 int64_t head_val = atomic64_read(head);
109 int64_t new, old;
110
111 do {
112 int cycle, space;
113
114 xlog_crack_grant_head_val(head_val, &cycle, &space);
115
116 space -= bytes;
117 if (space < 0) {
118 space += log->l_logsize;
119 cycle--;
120 }
121
122 old = head_val;
123 new = xlog_assign_grant_head_val(cycle, space);
124 head_val = atomic64_cmpxchg(head, old, new);
125 } while (head_val != old);
126}
127
128static void
129xlog_grant_add_space(
130 struct xlog *log,
131 atomic64_t *head,
132 int bytes)
133{
134 int64_t head_val = atomic64_read(head);
135 int64_t new, old;
136
137 do {
138 int tmp;
139 int cycle, space;
140
141 xlog_crack_grant_head_val(head_val, &cycle, &space);
142
143 tmp = log->l_logsize - space;
144 if (tmp > bytes)
145 space += bytes;
146 else {
147 space = bytes - tmp;
148 cycle++;
149 }
150
151 old = head_val;
152 new = xlog_assign_grant_head_val(cycle, space);
153 head_val = atomic64_cmpxchg(head, old, new);
154 } while (head_val != old);
155}
156
157STATIC void
158xlog_grant_head_init(
159 struct xlog_grant_head *head)
160{
161 xlog_assign_grant_head(&head->grant, 1, 0);
162 INIT_LIST_HEAD(&head->waiters);
163 spin_lock_init(&head->lock);
164}
165
166STATIC void
167xlog_grant_head_wake_all(
168 struct xlog_grant_head *head)
169{
170 struct xlog_ticket *tic;
171
172 spin_lock(&head->lock);
173 list_for_each_entry(tic, &head->waiters, t_queue)
174 wake_up_process(tic->t_task);
175 spin_unlock(&head->lock);
176}
177
178static inline int
179xlog_ticket_reservation(
180 struct xlog *log,
181 struct xlog_grant_head *head,
182 struct xlog_ticket *tic)
183{
184 if (head == &log->l_write_head) {
185 ASSERT(tic->t_flags & XLOG_TIC_PERM_RESERV);
186 return tic->t_unit_res;
187 } else {
188 if (tic->t_flags & XLOG_TIC_PERM_RESERV)
189 return tic->t_unit_res * tic->t_cnt;
190 else
191 return tic->t_unit_res;
192 }
193}
194
195STATIC bool
196xlog_grant_head_wake(
197 struct xlog *log,
198 struct xlog_grant_head *head,
199 int *free_bytes)
200{
201 struct xlog_ticket *tic;
202 int need_bytes;
203
204 list_for_each_entry(tic, &head->waiters, t_queue) {
205 need_bytes = xlog_ticket_reservation(log, head, tic);
206 if (*free_bytes < need_bytes)
207 return false;
208
209 *free_bytes -= need_bytes;
210 trace_xfs_log_grant_wake_up(log, tic);
211 wake_up_process(tic->t_task);
212 }
213
214 return true;
215}
216
217STATIC int
218xlog_grant_head_wait(
219 struct xlog *log,
220 struct xlog_grant_head *head,
221 struct xlog_ticket *tic,
222 int need_bytes)
223{
224 list_add_tail(&tic->t_queue, &head->waiters);
225
226 do {
227 if (XLOG_FORCED_SHUTDOWN(log))
228 goto shutdown;
229 xlog_grant_push_ail(log, need_bytes);
230
231 __set_current_state(TASK_UNINTERRUPTIBLE);
232 spin_unlock(&head->lock);
233
234 XFS_STATS_INC(xs_sleep_logspace);
235
236 trace_xfs_log_grant_sleep(log, tic);
237 schedule();
238 trace_xfs_log_grant_wake(log, tic);
239
240 spin_lock(&head->lock);
241 if (XLOG_FORCED_SHUTDOWN(log))
242 goto shutdown;
243 } while (xlog_space_left(log, &head->grant) < need_bytes);
244
245 list_del_init(&tic->t_queue);
246 return 0;
247shutdown:
248 list_del_init(&tic->t_queue);
249 return XFS_ERROR(EIO);
250}
251
252/*
253 * Atomically get the log space required for a log ticket.
254 *
255 * Once a ticket gets put onto head->waiters, it will only return after the
256 * needed reservation is satisfied.
257 *
258 * This function is structured so that it has a lock free fast path. This is
259 * necessary because every new transaction reservation will come through this
260 * path. Hence any lock will be globally hot if we take it unconditionally on
261 * every pass.
262 *
263 * As tickets are only ever moved on and off head->waiters under head->lock, we
264 * only need to take that lock if we are going to add the ticket to the queue
265 * and sleep. We can avoid taking the lock if the ticket was never added to
266 * head->waiters because the t_queue list head will be empty and we hold the
267 * only reference to it so it can safely be checked unlocked.
268 */
269STATIC int
270xlog_grant_head_check(
271 struct xlog *log,
272 struct xlog_grant_head *head,
273 struct xlog_ticket *tic,
274 int *need_bytes)
275{
276 int free_bytes;
277 int error = 0;
278
279 ASSERT(!(log->l_flags & XLOG_ACTIVE_RECOVERY));
280
281 /*
282 * If there are other waiters on the queue then give them a chance at
283 * logspace before us. Wake up the first waiters, if we do not wake
284 * up all the waiters then go to sleep waiting for more free space,
285 * otherwise try to get some space for this transaction.
286 */
287 *need_bytes = xlog_ticket_reservation(log, head, tic);
288 free_bytes = xlog_space_left(log, &head->grant);
289 if (!list_empty_careful(&head->waiters)) {
290 spin_lock(&head->lock);
291 if (!xlog_grant_head_wake(log, head, &free_bytes) ||
292 free_bytes < *need_bytes) {
293 error = xlog_grant_head_wait(log, head, tic,
294 *need_bytes);
295 }
296 spin_unlock(&head->lock);
297 } else if (free_bytes < *need_bytes) {
298 spin_lock(&head->lock);
299 error = xlog_grant_head_wait(log, head, tic, *need_bytes);
300 spin_unlock(&head->lock);
301 }
302
303 return error;
304}
305
306static void
307xlog_tic_reset_res(xlog_ticket_t *tic)
308{
309 tic->t_res_num = 0;
310 tic->t_res_arr_sum = 0;
311 tic->t_res_num_ophdrs = 0;
312}
313
314static void
315xlog_tic_add_region(xlog_ticket_t *tic, uint len, uint type)
316{
317 if (tic->t_res_num == XLOG_TIC_LEN_MAX) {
318 /* add to overflow and start again */
319 tic->t_res_o_flow += tic->t_res_arr_sum;
320 tic->t_res_num = 0;
321 tic->t_res_arr_sum = 0;
322 }
323
324 tic->t_res_arr[tic->t_res_num].r_len = len;
325 tic->t_res_arr[tic->t_res_num].r_type = type;
326 tic->t_res_arr_sum += len;
327 tic->t_res_num++;
328}
329
330/*
331 * Replenish the byte reservation required by moving the grant write head.
332 */
333int
334xfs_log_regrant(
335 struct xfs_mount *mp,
336 struct xlog_ticket *tic)
337{
338 struct xlog *log = mp->m_log;
339 int need_bytes;
340 int error = 0;
341
342 if (XLOG_FORCED_SHUTDOWN(log))
343 return XFS_ERROR(EIO);
344
345 XFS_STATS_INC(xs_try_logspace);
346
347 /*
348 * This is a new transaction on the ticket, so we need to change the
349 * transaction ID so that the next transaction has a different TID in
350 * the log. Just add one to the existing tid so that we can see chains
351 * of rolling transactions in the log easily.
352 */
353 tic->t_tid++;
354
355 xlog_grant_push_ail(log, tic->t_unit_res);
356
357 tic->t_curr_res = tic->t_unit_res;
358 xlog_tic_reset_res(tic);
359
360 if (tic->t_cnt > 0)
361 return 0;
362
363 trace_xfs_log_regrant(log, tic);
364
365 error = xlog_grant_head_check(log, &log->l_write_head, tic,
366 &need_bytes);
367 if (error)
368 goto out_error;
369
370 xlog_grant_add_space(log, &log->l_write_head.grant, need_bytes);
371 trace_xfs_log_regrant_exit(log, tic);
372 xlog_verify_grant_tail(log);
373 return 0;
374
375out_error:
376 /*
377 * If we are failing, make sure the ticket doesn't have any current
378 * reservations. We don't want to add this back when the ticket/
379 * transaction gets cancelled.
380 */
381 tic->t_curr_res = 0;
382 tic->t_cnt = 0; /* ungrant will give back unit_res * t_cnt. */
383 return error;
384}
385
386/*
387 * Reserve log space and return a ticket corresponding the reservation.
388 *
389 * Each reservation is going to reserve extra space for a log record header.
390 * When writes happen to the on-disk log, we don't subtract the length of the
391 * log record header from any reservation. By wasting space in each
392 * reservation, we prevent over allocation problems.
393 */
394int
395xfs_log_reserve(
396 struct xfs_mount *mp,
397 int unit_bytes,
398 int cnt,
399 struct xlog_ticket **ticp,
400 __uint8_t client,
401 bool permanent,
402 uint t_type)
403{
404 struct xlog *log = mp->m_log;
405 struct xlog_ticket *tic;
406 int need_bytes;
407 int error = 0;
408
409 ASSERT(client == XFS_TRANSACTION || client == XFS_LOG);
410
411 if (XLOG_FORCED_SHUTDOWN(log))
412 return XFS_ERROR(EIO);
413
414 XFS_STATS_INC(xs_try_logspace);
415
416 ASSERT(*ticp == NULL);
417 tic = xlog_ticket_alloc(log, unit_bytes, cnt, client, permanent,
418 KM_SLEEP | KM_MAYFAIL);
419 if (!tic)
420 return XFS_ERROR(ENOMEM);
421
422 tic->t_trans_type = t_type;
423 *ticp = tic;
424
425 xlog_grant_push_ail(log, tic->t_unit_res * tic->t_cnt);
426
427 trace_xfs_log_reserve(log, tic);
428
429 error = xlog_grant_head_check(log, &log->l_reserve_head, tic,
430 &need_bytes);
431 if (error)
432 goto out_error;
433
434 xlog_grant_add_space(log, &log->l_reserve_head.grant, need_bytes);
435 xlog_grant_add_space(log, &log->l_write_head.grant, need_bytes);
436 trace_xfs_log_reserve_exit(log, tic);
437 xlog_verify_grant_tail(log);
438 return 0;
439
440out_error:
441 /*
442 * If we are failing, make sure the ticket doesn't have any current
443 * reservations. We don't want to add this back when the ticket/
444 * transaction gets cancelled.
445 */
446 tic->t_curr_res = 0;
447 tic->t_cnt = 0; /* ungrant will give back unit_res * t_cnt. */
448 return error;
449}
450
451
452/*
453 * NOTES:
454 *
455 * 1. currblock field gets updated at startup and after in-core logs
456 * marked as with WANT_SYNC.
457 */
458
459/*
460 * This routine is called when a user of a log manager ticket is done with
461 * the reservation. If the ticket was ever used, then a commit record for
462 * the associated transaction is written out as a log operation header with
463 * no data. The flag XLOG_TIC_INITED is set when the first write occurs with
464 * a given ticket. If the ticket was one with a permanent reservation, then
465 * a few operations are done differently. Permanent reservation tickets by
466 * default don't release the reservation. They just commit the current
467 * transaction with the belief that the reservation is still needed. A flag
468 * must be passed in before permanent reservations are actually released.
469 * When these type of tickets are not released, they need to be set into
470 * the inited state again. By doing this, a start record will be written
471 * out when the next write occurs.
472 */
473xfs_lsn_t
474xfs_log_done(
475 struct xfs_mount *mp,
476 struct xlog_ticket *ticket,
477 struct xlog_in_core **iclog,
478 uint flags)
479{
480 struct xlog *log = mp->m_log;
481 xfs_lsn_t lsn = 0;
482
483 if (XLOG_FORCED_SHUTDOWN(log) ||
484 /*
485 * If nothing was ever written, don't write out commit record.
486 * If we get an error, just continue and give back the log ticket.
487 */
488 (((ticket->t_flags & XLOG_TIC_INITED) == 0) &&
489 (xlog_commit_record(log, ticket, iclog, &lsn)))) {
490 lsn = (xfs_lsn_t) -1;
491 if (ticket->t_flags & XLOG_TIC_PERM_RESERV) {
492 flags |= XFS_LOG_REL_PERM_RESERV;
493 }
494 }
495
496
497 if ((ticket->t_flags & XLOG_TIC_PERM_RESERV) == 0 ||
498 (flags & XFS_LOG_REL_PERM_RESERV)) {
499 trace_xfs_log_done_nonperm(log, ticket);
500
501 /*
502 * Release ticket if not permanent reservation or a specific
503 * request has been made to release a permanent reservation.
504 */
505 xlog_ungrant_log_space(log, ticket);
506 xfs_log_ticket_put(ticket);
507 } else {
508 trace_xfs_log_done_perm(log, ticket);
509
510 xlog_regrant_reserve_log_space(log, ticket);
511 /* If this ticket was a permanent reservation and we aren't
512 * trying to release it, reset the inited flags; so next time
513 * we write, a start record will be written out.
514 */
515 ticket->t_flags |= XLOG_TIC_INITED;
516 }
517
518 return lsn;
519}
520
521/*
522 * Attaches a new iclog I/O completion callback routine during
523 * transaction commit. If the log is in error state, a non-zero
524 * return code is handed back and the caller is responsible for
525 * executing the callback at an appropriate time.
526 */
527int
528xfs_log_notify(
529 struct xfs_mount *mp,
530 struct xlog_in_core *iclog,
531 xfs_log_callback_t *cb)
532{
533 int abortflg;
534
535 spin_lock(&iclog->ic_callback_lock);
536 abortflg = (iclog->ic_state & XLOG_STATE_IOERROR);
537 if (!abortflg) {
538 ASSERT_ALWAYS((iclog->ic_state == XLOG_STATE_ACTIVE) ||
539 (iclog->ic_state == XLOG_STATE_WANT_SYNC));
540 cb->cb_next = NULL;
541 *(iclog->ic_callback_tail) = cb;
542 iclog->ic_callback_tail = &(cb->cb_next);
543 }
544 spin_unlock(&iclog->ic_callback_lock);
545 return abortflg;
546}
547
548int
549xfs_log_release_iclog(
550 struct xfs_mount *mp,
551 struct xlog_in_core *iclog)
552{
553 if (xlog_state_release_iclog(mp->m_log, iclog)) {
554 xfs_force_shutdown(mp, SHUTDOWN_LOG_IO_ERROR);
555 return EIO;
556 }
557
558 return 0;
559}
560
561/*
562 * Mount a log filesystem
563 *
564 * mp - ubiquitous xfs mount point structure
565 * log_target - buftarg of on-disk log device
566 * blk_offset - Start block # where block size is 512 bytes (BBSIZE)
567 * num_bblocks - Number of BBSIZE blocks in on-disk log
568 *
569 * Return error or zero.
570 */
571int
572xfs_log_mount(
573 xfs_mount_t *mp,
574 xfs_buftarg_t *log_target,
575 xfs_daddr_t blk_offset,
576 int num_bblks)
577{
578 int error;
579
580 if (!(mp->m_flags & XFS_MOUNT_NORECOVERY))
581 xfs_notice(mp, "Mounting Filesystem");
582 else {
583 xfs_notice(mp,
584"Mounting filesystem in no-recovery mode. Filesystem will be inconsistent.");
585 ASSERT(mp->m_flags & XFS_MOUNT_RDONLY);
586 }
587
588 mp->m_log = xlog_alloc_log(mp, log_target, blk_offset, num_bblks);
589 if (IS_ERR(mp->m_log)) {
590 error = -PTR_ERR(mp->m_log);
591 goto out;
592 }
593
594 /*
595 * Initialize the AIL now we have a log.
596 */
597 error = xfs_trans_ail_init(mp);
598 if (error) {
599 xfs_warn(mp, "AIL initialisation failed: error %d", error);
600 goto out_free_log;
601 }
602 mp->m_log->l_ailp = mp->m_ail;
603
604 /*
605 * skip log recovery on a norecovery mount. pretend it all
606 * just worked.
607 */
608 if (!(mp->m_flags & XFS_MOUNT_NORECOVERY)) {
609 int readonly = (mp->m_flags & XFS_MOUNT_RDONLY);
610
611 if (readonly)
612 mp->m_flags &= ~XFS_MOUNT_RDONLY;
613
614 error = xlog_recover(mp->m_log);
615
616 if (readonly)
617 mp->m_flags |= XFS_MOUNT_RDONLY;
618 if (error) {
619 xfs_warn(mp, "log mount/recovery failed: error %d",
620 error);
621 goto out_destroy_ail;
622 }
623 }
624
625 /* Normal transactions can now occur */
626 mp->m_log->l_flags &= ~XLOG_ACTIVE_RECOVERY;
627
628 /*
629 * Now the log has been fully initialised and we know were our
630 * space grant counters are, we can initialise the permanent ticket
631 * needed for delayed logging to work.
632 */
633 xlog_cil_init_post_recovery(mp->m_log);
634
635 return 0;
636
637out_destroy_ail:
638 xfs_trans_ail_destroy(mp);
639out_free_log:
640 xlog_dealloc_log(mp->m_log);
641out:
642 return error;
643}
644
645/*
646 * Finish the recovery of the file system. This is separate from
647 * the xfs_log_mount() call, because it depends on the code in
648 * xfs_mountfs() to read in the root and real-time bitmap inodes
649 * between calling xfs_log_mount() and here.
650 *
651 * mp - ubiquitous xfs mount point structure
652 */
653int
654xfs_log_mount_finish(xfs_mount_t *mp)
655{
656 int error;
657
658 if (!(mp->m_flags & XFS_MOUNT_NORECOVERY))
659 error = xlog_recover_finish(mp->m_log);
660 else {
661 error = 0;
662 ASSERT(mp->m_flags & XFS_MOUNT_RDONLY);
663 }
664
665 return error;
666}
667
668/*
669 * Final log writes as part of unmount.
670 *
671 * Mark the filesystem clean as unmount happens. Note that during relocation
672 * this routine needs to be executed as part of source-bag while the
673 * deallocation must not be done until source-end.
674 */
675
676/*
677 * Unmount record used to have a string "Unmount filesystem--" in the
678 * data section where the "Un" was really a magic number (XLOG_UNMOUNT_TYPE).
679 * We just write the magic number now since that particular field isn't
680 * currently architecture converted and "nUmount" is a bit foo.
681 * As far as I know, there weren't any dependencies on the old behaviour.
682 */
683
684int
685xfs_log_unmount_write(xfs_mount_t *mp)
686{
687 xlog_t *log = mp->m_log;
688 xlog_in_core_t *iclog;
689#ifdef DEBUG
690 xlog_in_core_t *first_iclog;
691#endif
692 xlog_ticket_t *tic = NULL;
693 xfs_lsn_t lsn;
694 int error;
695
696 /*
697 * Don't write out unmount record on read-only mounts.
698 * Or, if we are doing a forced umount (typically because of IO errors).
699 */
700 if (mp->m_flags & XFS_MOUNT_RDONLY)
701 return 0;
702
703 error = _xfs_log_force(mp, XFS_LOG_SYNC, NULL);
704 ASSERT(error || !(XLOG_FORCED_SHUTDOWN(log)));
705
706#ifdef DEBUG
707 first_iclog = iclog = log->l_iclog;
708 do {
709 if (!(iclog->ic_state & XLOG_STATE_IOERROR)) {
710 ASSERT(iclog->ic_state & XLOG_STATE_ACTIVE);
711 ASSERT(iclog->ic_offset == 0);
712 }
713 iclog = iclog->ic_next;
714 } while (iclog != first_iclog);
715#endif
716 if (! (XLOG_FORCED_SHUTDOWN(log))) {
717 error = xfs_log_reserve(mp, 600, 1, &tic,
718 XFS_LOG, 0, XLOG_UNMOUNT_REC_TYPE);
719 if (!error) {
720 /* the data section must be 32 bit size aligned */
721 struct {
722 __uint16_t magic;
723 __uint16_t pad1;
724 __uint32_t pad2; /* may as well make it 64 bits */
725 } magic = {
726 .magic = XLOG_UNMOUNT_TYPE,
727 };
728 struct xfs_log_iovec reg = {
729 .i_addr = &magic,
730 .i_len = sizeof(magic),
731 .i_type = XLOG_REG_TYPE_UNMOUNT,
732 };
733 struct xfs_log_vec vec = {
734 .lv_niovecs = 1,
735 .lv_iovecp = ®,
736 };
737
738 /* remove inited flag, and account for space used */
739 tic->t_flags = 0;
740 tic->t_curr_res -= sizeof(magic);
741 error = xlog_write(log, &vec, tic, &lsn,
742 NULL, XLOG_UNMOUNT_TRANS);
743 /*
744 * At this point, we're umounting anyway,
745 * so there's no point in transitioning log state
746 * to IOERROR. Just continue...
747 */
748 }
749
750 if (error)
751 xfs_alert(mp, "%s: unmount record failed", __func__);
752
753
754 spin_lock(&log->l_icloglock);
755 iclog = log->l_iclog;
756 atomic_inc(&iclog->ic_refcnt);
757 xlog_state_want_sync(log, iclog);
758 spin_unlock(&log->l_icloglock);
759 error = xlog_state_release_iclog(log, iclog);
760
761 spin_lock(&log->l_icloglock);
762 if (!(iclog->ic_state == XLOG_STATE_ACTIVE ||
763 iclog->ic_state == XLOG_STATE_DIRTY)) {
764 if (!XLOG_FORCED_SHUTDOWN(log)) {
765 xlog_wait(&iclog->ic_force_wait,
766 &log->l_icloglock);
767 } else {
768 spin_unlock(&log->l_icloglock);
769 }
770 } else {
771 spin_unlock(&log->l_icloglock);
772 }
773 if (tic) {
774 trace_xfs_log_umount_write(log, tic);
775 xlog_ungrant_log_space(log, tic);
776 xfs_log_ticket_put(tic);
777 }
778 } else {
779 /*
780 * We're already in forced_shutdown mode, couldn't
781 * even attempt to write out the unmount transaction.
782 *
783 * Go through the motions of sync'ing and releasing
784 * the iclog, even though no I/O will actually happen,
785 * we need to wait for other log I/Os that may already
786 * be in progress. Do this as a separate section of
787 * code so we'll know if we ever get stuck here that
788 * we're in this odd situation of trying to unmount
789 * a file system that went into forced_shutdown as
790 * the result of an unmount..
791 */
792 spin_lock(&log->l_icloglock);
793 iclog = log->l_iclog;
794 atomic_inc(&iclog->ic_refcnt);
795
796 xlog_state_want_sync(log, iclog);
797 spin_unlock(&log->l_icloglock);
798 error = xlog_state_release_iclog(log, iclog);
799
800 spin_lock(&log->l_icloglock);
801
802 if ( ! ( iclog->ic_state == XLOG_STATE_ACTIVE
803 || iclog->ic_state == XLOG_STATE_DIRTY
804 || iclog->ic_state == XLOG_STATE_IOERROR) ) {
805
806 xlog_wait(&iclog->ic_force_wait,
807 &log->l_icloglock);
808 } else {
809 spin_unlock(&log->l_icloglock);
810 }
811 }
812
813 return error;
814} /* xfs_log_unmount_write */
815
816/*
817 * Deallocate log structures for unmount/relocation.
818 *
819 * We need to stop the aild from running before we destroy
820 * and deallocate the log as the aild references the log.
821 */
822void
823xfs_log_unmount(xfs_mount_t *mp)
824{
825 cancel_delayed_work_sync(&mp->m_sync_work);
826 xfs_trans_ail_destroy(mp);
827 xlog_dealloc_log(mp->m_log);
828}
829
830void
831xfs_log_item_init(
832 struct xfs_mount *mp,
833 struct xfs_log_item *item,
834 int type,
835 const struct xfs_item_ops *ops)
836{
837 item->li_mountp = mp;
838 item->li_ailp = mp->m_ail;
839 item->li_type = type;
840 item->li_ops = ops;
841 item->li_lv = NULL;
842
843 INIT_LIST_HEAD(&item->li_ail);
844 INIT_LIST_HEAD(&item->li_cil);
845}
846
847/*
848 * Wake up processes waiting for log space after we have moved the log tail.
849 */
850void
851xfs_log_space_wake(
852 struct xfs_mount *mp)
853{
854 struct xlog *log = mp->m_log;
855 int free_bytes;
856
857 if (XLOG_FORCED_SHUTDOWN(log))
858 return;
859
860 if (!list_empty_careful(&log->l_write_head.waiters)) {
861 ASSERT(!(log->l_flags & XLOG_ACTIVE_RECOVERY));
862
863 spin_lock(&log->l_write_head.lock);
864 free_bytes = xlog_space_left(log, &log->l_write_head.grant);
865 xlog_grant_head_wake(log, &log->l_write_head, &free_bytes);
866 spin_unlock(&log->l_write_head.lock);
867 }
868
869 if (!list_empty_careful(&log->l_reserve_head.waiters)) {
870 ASSERT(!(log->l_flags & XLOG_ACTIVE_RECOVERY));
871
872 spin_lock(&log->l_reserve_head.lock);
873 free_bytes = xlog_space_left(log, &log->l_reserve_head.grant);
874 xlog_grant_head_wake(log, &log->l_reserve_head, &free_bytes);
875 spin_unlock(&log->l_reserve_head.lock);
876 }
877}
878
879/*
880 * Determine if we have a transaction that has gone to disk
881 * that needs to be covered. To begin the transition to the idle state
882 * firstly the log needs to be idle (no AIL and nothing in the iclogs).
883 * If we are then in a state where covering is needed, the caller is informed
884 * that dummy transactions are required to move the log into the idle state.
885 *
886 * Because this is called as part of the sync process, we should also indicate
887 * that dummy transactions should be issued in anything but the covered or
888 * idle states. This ensures that the log tail is accurately reflected in
889 * the log at the end of the sync, hence if a crash occurrs avoids replay
890 * of transactions where the metadata is already on disk.
891 */
892int
893xfs_log_need_covered(xfs_mount_t *mp)
894{
895 int needed = 0;
896 xlog_t *log = mp->m_log;
897
898 if (!xfs_fs_writable(mp))
899 return 0;
900
901 spin_lock(&log->l_icloglock);
902 switch (log->l_covered_state) {
903 case XLOG_STATE_COVER_DONE:
904 case XLOG_STATE_COVER_DONE2:
905 case XLOG_STATE_COVER_IDLE:
906 break;
907 case XLOG_STATE_COVER_NEED:
908 case XLOG_STATE_COVER_NEED2:
909 if (!xfs_ail_min_lsn(log->l_ailp) &&
910 xlog_iclogs_empty(log)) {
911 if (log->l_covered_state == XLOG_STATE_COVER_NEED)
912 log->l_covered_state = XLOG_STATE_COVER_DONE;
913 else
914 log->l_covered_state = XLOG_STATE_COVER_DONE2;
915 }
916 /* FALLTHRU */
917 default:
918 needed = 1;
919 break;
920 }
921 spin_unlock(&log->l_icloglock);
922 return needed;
923}
924
925/*
926 * We may be holding the log iclog lock upon entering this routine.
927 */
928xfs_lsn_t
929xlog_assign_tail_lsn_locked(
930 struct xfs_mount *mp)
931{
932 struct xlog *log = mp->m_log;
933 struct xfs_log_item *lip;
934 xfs_lsn_t tail_lsn;
935
936 assert_spin_locked(&mp->m_ail->xa_lock);
937
938 /*
939 * To make sure we always have a valid LSN for the log tail we keep
940 * track of the last LSN which was committed in log->l_last_sync_lsn,
941 * and use that when the AIL was empty.
942 */
943 lip = xfs_ail_min(mp->m_ail);
944 if (lip)
945 tail_lsn = lip->li_lsn;
946 else
947 tail_lsn = atomic64_read(&log->l_last_sync_lsn);
948 atomic64_set(&log->l_tail_lsn, tail_lsn);
949 return tail_lsn;
950}
951
952xfs_lsn_t
953xlog_assign_tail_lsn(
954 struct xfs_mount *mp)
955{
956 xfs_lsn_t tail_lsn;
957
958 spin_lock(&mp->m_ail->xa_lock);
959 tail_lsn = xlog_assign_tail_lsn_locked(mp);
960 spin_unlock(&mp->m_ail->xa_lock);
961
962 return tail_lsn;
963}
964
965/*
966 * Return the space in the log between the tail and the head. The head
967 * is passed in the cycle/bytes formal parms. In the special case where
968 * the reserve head has wrapped passed the tail, this calculation is no
969 * longer valid. In this case, just return 0 which means there is no space
970 * in the log. This works for all places where this function is called
971 * with the reserve head. Of course, if the write head were to ever
972 * wrap the tail, we should blow up. Rather than catch this case here,
973 * we depend on other ASSERTions in other parts of the code. XXXmiken
974 *
975 * This code also handles the case where the reservation head is behind
976 * the tail. The details of this case are described below, but the end
977 * result is that we return the size of the log as the amount of space left.
978 */
979STATIC int
980xlog_space_left(
981 struct xlog *log,
982 atomic64_t *head)
983{
984 int free_bytes;
985 int tail_bytes;
986 int tail_cycle;
987 int head_cycle;
988 int head_bytes;
989
990 xlog_crack_grant_head(head, &head_cycle, &head_bytes);
991 xlog_crack_atomic_lsn(&log->l_tail_lsn, &tail_cycle, &tail_bytes);
992 tail_bytes = BBTOB(tail_bytes);
993 if (tail_cycle == head_cycle && head_bytes >= tail_bytes)
994 free_bytes = log->l_logsize - (head_bytes - tail_bytes);
995 else if (tail_cycle + 1 < head_cycle)
996 return 0;
997 else if (tail_cycle < head_cycle) {
998 ASSERT(tail_cycle == (head_cycle - 1));
999 free_bytes = tail_bytes - head_bytes;
1000 } else {
1001 /*
1002 * The reservation head is behind the tail.
1003 * In this case we just want to return the size of the
1004 * log as the amount of space left.
1005 */
1006 xfs_alert(log->l_mp,
1007 "xlog_space_left: head behind tail\n"
1008 " tail_cycle = %d, tail_bytes = %d\n"
1009 " GH cycle = %d, GH bytes = %d",
1010 tail_cycle, tail_bytes, head_cycle, head_bytes);
1011 ASSERT(0);
1012 free_bytes = log->l_logsize;
1013 }
1014 return free_bytes;
1015}
1016
1017
1018/*
1019 * Log function which is called when an io completes.
1020 *
1021 * The log manager needs its own routine, in order to control what
1022 * happens with the buffer after the write completes.
1023 */
1024void
1025xlog_iodone(xfs_buf_t *bp)
1026{
1027 xlog_in_core_t *iclog = bp->b_fspriv;
1028 xlog_t *l = iclog->ic_log;
1029 int aborted = 0;
1030
1031 /*
1032 * Race to shutdown the filesystem if we see an error.
1033 */
1034 if (XFS_TEST_ERROR((xfs_buf_geterror(bp)), l->l_mp,
1035 XFS_ERRTAG_IODONE_IOERR, XFS_RANDOM_IODONE_IOERR)) {
1036 xfs_buf_ioerror_alert(bp, __func__);
1037 xfs_buf_stale(bp);
1038 xfs_force_shutdown(l->l_mp, SHUTDOWN_LOG_IO_ERROR);
1039 /*
1040 * This flag will be propagated to the trans-committed
1041 * callback routines to let them know that the log-commit
1042 * didn't succeed.
1043 */
1044 aborted = XFS_LI_ABORTED;
1045 } else if (iclog->ic_state & XLOG_STATE_IOERROR) {
1046 aborted = XFS_LI_ABORTED;
1047 }
1048
1049 /* log I/O is always issued ASYNC */
1050 ASSERT(XFS_BUF_ISASYNC(bp));
1051 xlog_state_done_syncing(iclog, aborted);
1052 /*
1053 * do not reference the buffer (bp) here as we could race
1054 * with it being freed after writing the unmount record to the
1055 * log.
1056 */
1057
1058} /* xlog_iodone */
1059
1060/*
1061 * Return size of each in-core log record buffer.
1062 *
1063 * All machines get 8 x 32kB buffers by default, unless tuned otherwise.
1064 *
1065 * If the filesystem blocksize is too large, we may need to choose a
1066 * larger size since the directory code currently logs entire blocks.
1067 */
1068
1069STATIC void
1070xlog_get_iclog_buffer_size(xfs_mount_t *mp,
1071 xlog_t *log)
1072{
1073 int size;
1074 int xhdrs;
1075
1076 if (mp->m_logbufs <= 0)
1077 log->l_iclog_bufs = XLOG_MAX_ICLOGS;
1078 else
1079 log->l_iclog_bufs = mp->m_logbufs;
1080
1081 /*
1082 * Buffer size passed in from mount system call.
1083 */
1084 if (mp->m_logbsize > 0) {
1085 size = log->l_iclog_size = mp->m_logbsize;
1086 log->l_iclog_size_log = 0;
1087 while (size != 1) {
1088 log->l_iclog_size_log++;
1089 size >>= 1;
1090 }
1091
1092 if (xfs_sb_version_haslogv2(&mp->m_sb)) {
1093 /* # headers = size / 32k
1094 * one header holds cycles from 32k of data
1095 */
1096
1097 xhdrs = mp->m_logbsize / XLOG_HEADER_CYCLE_SIZE;
1098 if (mp->m_logbsize % XLOG_HEADER_CYCLE_SIZE)
1099 xhdrs++;
1100 log->l_iclog_hsize = xhdrs << BBSHIFT;
1101 log->l_iclog_heads = xhdrs;
1102 } else {
1103 ASSERT(mp->m_logbsize <= XLOG_BIG_RECORD_BSIZE);
1104 log->l_iclog_hsize = BBSIZE;
1105 log->l_iclog_heads = 1;
1106 }
1107 goto done;
1108 }
1109
1110 /* All machines use 32kB buffers by default. */
1111 log->l_iclog_size = XLOG_BIG_RECORD_BSIZE;
1112 log->l_iclog_size_log = XLOG_BIG_RECORD_BSHIFT;
1113
1114 /* the default log size is 16k or 32k which is one header sector */
1115 log->l_iclog_hsize = BBSIZE;
1116 log->l_iclog_heads = 1;
1117
1118done:
1119 /* are we being asked to make the sizes selected above visible? */
1120 if (mp->m_logbufs == 0)
1121 mp->m_logbufs = log->l_iclog_bufs;
1122 if (mp->m_logbsize == 0)
1123 mp->m_logbsize = log->l_iclog_size;
1124} /* xlog_get_iclog_buffer_size */
1125
1126
1127/*
1128 * This routine initializes some of the log structure for a given mount point.
1129 * Its primary purpose is to fill in enough, so recovery can occur. However,
1130 * some other stuff may be filled in too.
1131 */
1132STATIC xlog_t *
1133xlog_alloc_log(xfs_mount_t *mp,
1134 xfs_buftarg_t *log_target,
1135 xfs_daddr_t blk_offset,
1136 int num_bblks)
1137{
1138 xlog_t *log;
1139 xlog_rec_header_t *head;
1140 xlog_in_core_t **iclogp;
1141 xlog_in_core_t *iclog, *prev_iclog=NULL;
1142 xfs_buf_t *bp;
1143 int i;
1144 int error = ENOMEM;
1145 uint log2_size = 0;
1146
1147 log = kmem_zalloc(sizeof(xlog_t), KM_MAYFAIL);
1148 if (!log) {
1149 xfs_warn(mp, "Log allocation failed: No memory!");
1150 goto out;
1151 }
1152
1153 log->l_mp = mp;
1154 log->l_targ = log_target;
1155 log->l_logsize = BBTOB(num_bblks);
1156 log->l_logBBstart = blk_offset;
1157 log->l_logBBsize = num_bblks;
1158 log->l_covered_state = XLOG_STATE_COVER_IDLE;
1159 log->l_flags |= XLOG_ACTIVE_RECOVERY;
1160
1161 log->l_prev_block = -1;
1162 /* log->l_tail_lsn = 0x100000000LL; cycle = 1; current block = 0 */
1163 xlog_assign_atomic_lsn(&log->l_tail_lsn, 1, 0);
1164 xlog_assign_atomic_lsn(&log->l_last_sync_lsn, 1, 0);
1165 log->l_curr_cycle = 1; /* 0 is bad since this is initial value */
1166
1167 xlog_grant_head_init(&log->l_reserve_head);
1168 xlog_grant_head_init(&log->l_write_head);
1169
1170 error = EFSCORRUPTED;
1171 if (xfs_sb_version_hassector(&mp->m_sb)) {
1172 log2_size = mp->m_sb.sb_logsectlog;
1173 if (log2_size < BBSHIFT) {
1174 xfs_warn(mp, "Log sector size too small (0x%x < 0x%x)",
1175 log2_size, BBSHIFT);
1176 goto out_free_log;
1177 }
1178
1179 log2_size -= BBSHIFT;
1180 if (log2_size > mp->m_sectbb_log) {
1181 xfs_warn(mp, "Log sector size too large (0x%x > 0x%x)",
1182 log2_size, mp->m_sectbb_log);
1183 goto out_free_log;
1184 }
1185
1186 /* for larger sector sizes, must have v2 or external log */
1187 if (log2_size && log->l_logBBstart > 0 &&
1188 !xfs_sb_version_haslogv2(&mp->m_sb)) {
1189 xfs_warn(mp,
1190 "log sector size (0x%x) invalid for configuration.",
1191 log2_size);
1192 goto out_free_log;
1193 }
1194 }
1195 log->l_sectBBsize = 1 << log2_size;
1196
1197 xlog_get_iclog_buffer_size(mp, log);
1198
1199 error = ENOMEM;
1200 bp = xfs_buf_alloc(mp->m_logdev_targp, 0, BTOBB(log->l_iclog_size), 0);
1201 if (!bp)
1202 goto out_free_log;
1203 bp->b_iodone = xlog_iodone;
1204 ASSERT(xfs_buf_islocked(bp));
1205 log->l_xbuf = bp;
1206
1207 spin_lock_init(&log->l_icloglock);
1208 init_waitqueue_head(&log->l_flush_wait);
1209
1210 iclogp = &log->l_iclog;
1211 /*
1212 * The amount of memory to allocate for the iclog structure is
1213 * rather funky due to the way the structure is defined. It is
1214 * done this way so that we can use different sizes for machines
1215 * with different amounts of memory. See the definition of
1216 * xlog_in_core_t in xfs_log_priv.h for details.
1217 */
1218 ASSERT(log->l_iclog_size >= 4096);
1219 for (i=0; i < log->l_iclog_bufs; i++) {
1220 *iclogp = kmem_zalloc(sizeof(xlog_in_core_t), KM_MAYFAIL);
1221 if (!*iclogp)
1222 goto out_free_iclog;
1223
1224 iclog = *iclogp;
1225 iclog->ic_prev = prev_iclog;
1226 prev_iclog = iclog;
1227
1228 bp = xfs_buf_get_uncached(mp->m_logdev_targp,
1229 BTOBB(log->l_iclog_size), 0);
1230 if (!bp)
1231 goto out_free_iclog;
1232
1233 bp->b_iodone = xlog_iodone;
1234 iclog->ic_bp = bp;
1235 iclog->ic_data = bp->b_addr;
1236#ifdef DEBUG
1237 log->l_iclog_bak[i] = (xfs_caddr_t)&(iclog->ic_header);
1238#endif
1239 head = &iclog->ic_header;
1240 memset(head, 0, sizeof(xlog_rec_header_t));
1241 head->h_magicno = cpu_to_be32(XLOG_HEADER_MAGIC_NUM);
1242 head->h_version = cpu_to_be32(
1243 xfs_sb_version_haslogv2(&log->l_mp->m_sb) ? 2 : 1);
1244 head->h_size = cpu_to_be32(log->l_iclog_size);
1245 /* new fields */
1246 head->h_fmt = cpu_to_be32(XLOG_FMT);
1247 memcpy(&head->h_fs_uuid, &mp->m_sb.sb_uuid, sizeof(uuid_t));
1248
1249 iclog->ic_size = BBTOB(bp->b_length) - log->l_iclog_hsize;
1250 iclog->ic_state = XLOG_STATE_ACTIVE;
1251 iclog->ic_log = log;
1252 atomic_set(&iclog->ic_refcnt, 0);
1253 spin_lock_init(&iclog->ic_callback_lock);
1254 iclog->ic_callback_tail = &(iclog->ic_callback);
1255 iclog->ic_datap = (char *)iclog->ic_data + log->l_iclog_hsize;
1256
1257 ASSERT(xfs_buf_islocked(iclog->ic_bp));
1258 init_waitqueue_head(&iclog->ic_force_wait);
1259 init_waitqueue_head(&iclog->ic_write_wait);
1260
1261 iclogp = &iclog->ic_next;
1262 }
1263 *iclogp = log->l_iclog; /* complete ring */
1264 log->l_iclog->ic_prev = prev_iclog; /* re-write 1st prev ptr */
1265
1266 error = xlog_cil_init(log);
1267 if (error)
1268 goto out_free_iclog;
1269 return log;
1270
1271out_free_iclog:
1272 for (iclog = log->l_iclog; iclog; iclog = prev_iclog) {
1273 prev_iclog = iclog->ic_next;
1274 if (iclog->ic_bp)
1275 xfs_buf_free(iclog->ic_bp);
1276 kmem_free(iclog);
1277 }
1278 spinlock_destroy(&log->l_icloglock);
1279 xfs_buf_free(log->l_xbuf);
1280out_free_log:
1281 kmem_free(log);
1282out:
1283 return ERR_PTR(-error);
1284} /* xlog_alloc_log */
1285
1286
1287/*
1288 * Write out the commit record of a transaction associated with the given
1289 * ticket. Return the lsn of the commit record.
1290 */
1291STATIC int
1292xlog_commit_record(
1293 struct xlog *log,
1294 struct xlog_ticket *ticket,
1295 struct xlog_in_core **iclog,
1296 xfs_lsn_t *commitlsnp)
1297{
1298 struct xfs_mount *mp = log->l_mp;
1299 int error;
1300 struct xfs_log_iovec reg = {
1301 .i_addr = NULL,
1302 .i_len = 0,
1303 .i_type = XLOG_REG_TYPE_COMMIT,
1304 };
1305 struct xfs_log_vec vec = {
1306 .lv_niovecs = 1,
1307 .lv_iovecp = ®,
1308 };
1309
1310 ASSERT_ALWAYS(iclog);
1311 error = xlog_write(log, &vec, ticket, commitlsnp, iclog,
1312 XLOG_COMMIT_TRANS);
1313 if (error)
1314 xfs_force_shutdown(mp, SHUTDOWN_LOG_IO_ERROR);
1315 return error;
1316}
1317
1318/*
1319 * Push on the buffer cache code if we ever use more than 75% of the on-disk
1320 * log space. This code pushes on the lsn which would supposedly free up
1321 * the 25% which we want to leave free. We may need to adopt a policy which
1322 * pushes on an lsn which is further along in the log once we reach the high
1323 * water mark. In this manner, we would be creating a low water mark.
1324 */
1325STATIC void
1326xlog_grant_push_ail(
1327 struct xlog *log,
1328 int need_bytes)
1329{
1330 xfs_lsn_t threshold_lsn = 0;
1331 xfs_lsn_t last_sync_lsn;
1332 int free_blocks;
1333 int free_bytes;
1334 int threshold_block;
1335 int threshold_cycle;
1336 int free_threshold;
1337
1338 ASSERT(BTOBB(need_bytes) < log->l_logBBsize);
1339
1340 free_bytes = xlog_space_left(log, &log->l_reserve_head.grant);
1341 free_blocks = BTOBBT(free_bytes);
1342
1343 /*
1344 * Set the threshold for the minimum number of free blocks in the
1345 * log to the maximum of what the caller needs, one quarter of the
1346 * log, and 256 blocks.
1347 */
1348 free_threshold = BTOBB(need_bytes);
1349 free_threshold = MAX(free_threshold, (log->l_logBBsize >> 2));
1350 free_threshold = MAX(free_threshold, 256);
1351 if (free_blocks >= free_threshold)
1352 return;
1353
1354 xlog_crack_atomic_lsn(&log->l_tail_lsn, &threshold_cycle,
1355 &threshold_block);
1356 threshold_block += free_threshold;
1357 if (threshold_block >= log->l_logBBsize) {
1358 threshold_block -= log->l_logBBsize;
1359 threshold_cycle += 1;
1360 }
1361 threshold_lsn = xlog_assign_lsn(threshold_cycle,
1362 threshold_block);
1363 /*
1364 * Don't pass in an lsn greater than the lsn of the last
1365 * log record known to be on disk. Use a snapshot of the last sync lsn
1366 * so that it doesn't change between the compare and the set.
1367 */
1368 last_sync_lsn = atomic64_read(&log->l_last_sync_lsn);
1369 if (XFS_LSN_CMP(threshold_lsn, last_sync_lsn) > 0)
1370 threshold_lsn = last_sync_lsn;
1371
1372 /*
1373 * Get the transaction layer to kick the dirty buffers out to
1374 * disk asynchronously. No point in trying to do this if
1375 * the filesystem is shutting down.
1376 */
1377 if (!XLOG_FORCED_SHUTDOWN(log))
1378 xfs_ail_push(log->l_ailp, threshold_lsn);
1379}
1380
1381/*
1382 * The bdstrat callback function for log bufs. This gives us a central
1383 * place to trap bufs in case we get hit by a log I/O error and need to
1384 * shutdown. Actually, in practice, even when we didn't get a log error,
1385 * we transition the iclogs to IOERROR state *after* flushing all existing
1386 * iclogs to disk. This is because we don't want anymore new transactions to be
1387 * started or completed afterwards.
1388 */
1389STATIC int
1390xlog_bdstrat(
1391 struct xfs_buf *bp)
1392{
1393 struct xlog_in_core *iclog = bp->b_fspriv;
1394
1395 if (iclog->ic_state & XLOG_STATE_IOERROR) {
1396 xfs_buf_ioerror(bp, EIO);
1397 xfs_buf_stale(bp);
1398 xfs_buf_ioend(bp, 0);
1399 /*
1400 * It would seem logical to return EIO here, but we rely on
1401 * the log state machine to propagate I/O errors instead of
1402 * doing it here.
1403 */
1404 return 0;
1405 }
1406
1407 xfs_buf_iorequest(bp);
1408 return 0;
1409}
1410
1411/*
1412 * Flush out the in-core log (iclog) to the on-disk log in an asynchronous
1413 * fashion. Previously, we should have moved the current iclog
1414 * ptr in the log to point to the next available iclog. This allows further
1415 * write to continue while this code syncs out an iclog ready to go.
1416 * Before an in-core log can be written out, the data section must be scanned
1417 * to save away the 1st word of each BBSIZE block into the header. We replace
1418 * it with the current cycle count. Each BBSIZE block is tagged with the
1419 * cycle count because there in an implicit assumption that drives will
1420 * guarantee that entire 512 byte blocks get written at once. In other words,
1421 * we can't have part of a 512 byte block written and part not written. By
1422 * tagging each block, we will know which blocks are valid when recovering
1423 * after an unclean shutdown.
1424 *
1425 * This routine is single threaded on the iclog. No other thread can be in
1426 * this routine with the same iclog. Changing contents of iclog can there-
1427 * fore be done without grabbing the state machine lock. Updating the global
1428 * log will require grabbing the lock though.
1429 *
1430 * The entire log manager uses a logical block numbering scheme. Only
1431 * log_sync (and then only bwrite()) know about the fact that the log may
1432 * not start with block zero on a given device. The log block start offset
1433 * is added immediately before calling bwrite().
1434 */
1435
1436STATIC int
1437xlog_sync(xlog_t *log,
1438 xlog_in_core_t *iclog)
1439{
1440 xfs_caddr_t dptr; /* pointer to byte sized element */
1441 xfs_buf_t *bp;
1442 int i;
1443 uint count; /* byte count of bwrite */
1444 uint count_init; /* initial count before roundup */
1445 int roundoff; /* roundoff to BB or stripe */
1446 int split = 0; /* split write into two regions */
1447 int error;
1448 int v2 = xfs_sb_version_haslogv2(&log->l_mp->m_sb);
1449
1450 XFS_STATS_INC(xs_log_writes);
1451 ASSERT(atomic_read(&iclog->ic_refcnt) == 0);
1452
1453 /* Add for LR header */
1454 count_init = log->l_iclog_hsize + iclog->ic_offset;
1455
1456 /* Round out the log write size */
1457 if (v2 && log->l_mp->m_sb.sb_logsunit > 1) {
1458 /* we have a v2 stripe unit to use */
1459 count = XLOG_LSUNITTOB(log, XLOG_BTOLSUNIT(log, count_init));
1460 } else {
1461 count = BBTOB(BTOBB(count_init));
1462 }
1463 roundoff = count - count_init;
1464 ASSERT(roundoff >= 0);
1465 ASSERT((v2 && log->l_mp->m_sb.sb_logsunit > 1 &&
1466 roundoff < log->l_mp->m_sb.sb_logsunit)
1467 ||
1468 (log->l_mp->m_sb.sb_logsunit <= 1 &&
1469 roundoff < BBTOB(1)));
1470
1471 /* move grant heads by roundoff in sync */
1472 xlog_grant_add_space(log, &log->l_reserve_head.grant, roundoff);
1473 xlog_grant_add_space(log, &log->l_write_head.grant, roundoff);
1474
1475 /* put cycle number in every block */
1476 xlog_pack_data(log, iclog, roundoff);
1477
1478 /* real byte length */
1479 if (v2) {
1480 iclog->ic_header.h_len =
1481 cpu_to_be32(iclog->ic_offset + roundoff);
1482 } else {
1483 iclog->ic_header.h_len =
1484 cpu_to_be32(iclog->ic_offset);
1485 }
1486
1487 bp = iclog->ic_bp;
1488 XFS_BUF_SET_ADDR(bp, BLOCK_LSN(be64_to_cpu(iclog->ic_header.h_lsn)));
1489
1490 XFS_STATS_ADD(xs_log_blocks, BTOBB(count));
1491
1492 /* Do we need to split this write into 2 parts? */
1493 if (XFS_BUF_ADDR(bp) + BTOBB(count) > log->l_logBBsize) {
1494 split = count - (BBTOB(log->l_logBBsize - XFS_BUF_ADDR(bp)));
1495 count = BBTOB(log->l_logBBsize - XFS_BUF_ADDR(bp));
1496 iclog->ic_bwritecnt = 2; /* split into 2 writes */
1497 } else {
1498 iclog->ic_bwritecnt = 1;
1499 }
1500 bp->b_io_length = BTOBB(count);
1501 bp->b_fspriv = iclog;
1502 XFS_BUF_ZEROFLAGS(bp);
1503 XFS_BUF_ASYNC(bp);
1504 bp->b_flags |= XBF_SYNCIO;
1505
1506 if (log->l_mp->m_flags & XFS_MOUNT_BARRIER) {
1507 bp->b_flags |= XBF_FUA;
1508
1509 /*
1510 * Flush the data device before flushing the log to make
1511 * sure all meta data written back from the AIL actually made
1512 * it to disk before stamping the new log tail LSN into the
1513 * log buffer. For an external log we need to issue the
1514 * flush explicitly, and unfortunately synchronously here;
1515 * for an internal log we can simply use the block layer
1516 * state machine for preflushes.
1517 */
1518 if (log->l_mp->m_logdev_targp != log->l_mp->m_ddev_targp)
1519 xfs_blkdev_issue_flush(log->l_mp->m_ddev_targp);
1520 else
1521 bp->b_flags |= XBF_FLUSH;
1522 }
1523
1524 ASSERT(XFS_BUF_ADDR(bp) <= log->l_logBBsize-1);
1525 ASSERT(XFS_BUF_ADDR(bp) + BTOBB(count) <= log->l_logBBsize);
1526
1527 xlog_verify_iclog(log, iclog, count, B_TRUE);
1528
1529 /* account for log which doesn't start at block #0 */
1530 XFS_BUF_SET_ADDR(bp, XFS_BUF_ADDR(bp) + log->l_logBBstart);
1531 /*
1532 * Don't call xfs_bwrite here. We do log-syncs even when the filesystem
1533 * is shutting down.
1534 */
1535 XFS_BUF_WRITE(bp);
1536
1537 error = xlog_bdstrat(bp);
1538 if (error) {
1539 xfs_buf_ioerror_alert(bp, "xlog_sync");
1540 return error;
1541 }
1542 if (split) {
1543 bp = iclog->ic_log->l_xbuf;
1544 XFS_BUF_SET_ADDR(bp, 0); /* logical 0 */
1545 xfs_buf_associate_memory(bp,
1546 (char *)&iclog->ic_header + count, split);
1547 bp->b_fspriv = iclog;
1548 XFS_BUF_ZEROFLAGS(bp);
1549 XFS_BUF_ASYNC(bp);
1550 bp->b_flags |= XBF_SYNCIO;
1551 if (log->l_mp->m_flags & XFS_MOUNT_BARRIER)
1552 bp->b_flags |= XBF_FUA;
1553 dptr = bp->b_addr;
1554 /*
1555 * Bump the cycle numbers at the start of each block
1556 * since this part of the buffer is at the start of
1557 * a new cycle. Watch out for the header magic number
1558 * case, though.
1559 */
1560 for (i = 0; i < split; i += BBSIZE) {
1561 be32_add_cpu((__be32 *)dptr, 1);
1562 if (be32_to_cpu(*(__be32 *)dptr) == XLOG_HEADER_MAGIC_NUM)
1563 be32_add_cpu((__be32 *)dptr, 1);
1564 dptr += BBSIZE;
1565 }
1566
1567 ASSERT(XFS_BUF_ADDR(bp) <= log->l_logBBsize-1);
1568 ASSERT(XFS_BUF_ADDR(bp) + BTOBB(count) <= log->l_logBBsize);
1569
1570 /* account for internal log which doesn't start at block #0 */
1571 XFS_BUF_SET_ADDR(bp, XFS_BUF_ADDR(bp) + log->l_logBBstart);
1572 XFS_BUF_WRITE(bp);
1573 error = xlog_bdstrat(bp);
1574 if (error) {
1575 xfs_buf_ioerror_alert(bp, "xlog_sync (split)");
1576 return error;
1577 }
1578 }
1579 return 0;
1580} /* xlog_sync */
1581
1582
1583/*
1584 * Deallocate a log structure
1585 */
1586STATIC void
1587xlog_dealloc_log(xlog_t *log)
1588{
1589 xlog_in_core_t *iclog, *next_iclog;
1590 int i;
1591
1592 xlog_cil_destroy(log);
1593
1594 /*
1595 * always need to ensure that the extra buffer does not point to memory
1596 * owned by another log buffer before we free it.
1597 */
1598 xfs_buf_set_empty(log->l_xbuf, BTOBB(log->l_iclog_size));
1599 xfs_buf_free(log->l_xbuf);
1600
1601 iclog = log->l_iclog;
1602 for (i=0; i<log->l_iclog_bufs; i++) {
1603 xfs_buf_free(iclog->ic_bp);
1604 next_iclog = iclog->ic_next;
1605 kmem_free(iclog);
1606 iclog = next_iclog;
1607 }
1608 spinlock_destroy(&log->l_icloglock);
1609
1610 log->l_mp->m_log = NULL;
1611 kmem_free(log);
1612} /* xlog_dealloc_log */
1613
1614/*
1615 * Update counters atomically now that memcpy is done.
1616 */
1617/* ARGSUSED */
1618static inline void
1619xlog_state_finish_copy(xlog_t *log,
1620 xlog_in_core_t *iclog,
1621 int record_cnt,
1622 int copy_bytes)
1623{
1624 spin_lock(&log->l_icloglock);
1625
1626 be32_add_cpu(&iclog->ic_header.h_num_logops, record_cnt);
1627 iclog->ic_offset += copy_bytes;
1628
1629 spin_unlock(&log->l_icloglock);
1630} /* xlog_state_finish_copy */
1631
1632
1633
1634
1635/*
1636 * print out info relating to regions written which consume
1637 * the reservation
1638 */
1639void
1640xlog_print_tic_res(
1641 struct xfs_mount *mp,
1642 struct xlog_ticket *ticket)
1643{
1644 uint i;
1645 uint ophdr_spc = ticket->t_res_num_ophdrs * (uint)sizeof(xlog_op_header_t);
1646
1647 /* match with XLOG_REG_TYPE_* in xfs_log.h */
1648 static char *res_type_str[XLOG_REG_TYPE_MAX] = {
1649 "bformat",
1650 "bchunk",
1651 "efi_format",
1652 "efd_format",
1653 "iformat",
1654 "icore",
1655 "iext",
1656 "ibroot",
1657 "ilocal",
1658 "iattr_ext",
1659 "iattr_broot",
1660 "iattr_local",
1661 "qformat",
1662 "dquot",
1663 "quotaoff",
1664 "LR header",
1665 "unmount",
1666 "commit",
1667 "trans header"
1668 };
1669 static char *trans_type_str[XFS_TRANS_TYPE_MAX] = {
1670 "SETATTR_NOT_SIZE",
1671 "SETATTR_SIZE",
1672 "INACTIVE",
1673 "CREATE",
1674 "CREATE_TRUNC",
1675 "TRUNCATE_FILE",
1676 "REMOVE",
1677 "LINK",
1678 "RENAME",
1679 "MKDIR",
1680 "RMDIR",
1681 "SYMLINK",
1682 "SET_DMATTRS",
1683 "GROWFS",
1684 "STRAT_WRITE",
1685 "DIOSTRAT",
1686 "WRITE_SYNC",
1687 "WRITEID",
1688 "ADDAFORK",
1689 "ATTRINVAL",
1690 "ATRUNCATE",
1691 "ATTR_SET",
1692 "ATTR_RM",
1693 "ATTR_FLAG",
1694 "CLEAR_AGI_BUCKET",
1695 "QM_SBCHANGE",
1696 "DUMMY1",
1697 "DUMMY2",
1698 "QM_QUOTAOFF",
1699 "QM_DQALLOC",
1700 "QM_SETQLIM",
1701 "QM_DQCLUSTER",
1702 "QM_QINOCREATE",
1703 "QM_QUOTAOFF_END",
1704 "SB_UNIT",
1705 "FSYNC_TS",
1706 "GROWFSRT_ALLOC",
1707 "GROWFSRT_ZERO",
1708 "GROWFSRT_FREE",
1709 "SWAPEXT"
1710 };
1711
1712 xfs_warn(mp,
1713 "xlog_write: reservation summary:\n"
1714 " trans type = %s (%u)\n"
1715 " unit res = %d bytes\n"
1716 " current res = %d bytes\n"
1717 " total reg = %u bytes (o/flow = %u bytes)\n"
1718 " ophdrs = %u (ophdr space = %u bytes)\n"
1719 " ophdr + reg = %u bytes\n"
1720 " num regions = %u\n",
1721 ((ticket->t_trans_type <= 0 ||
1722 ticket->t_trans_type > XFS_TRANS_TYPE_MAX) ?
1723 "bad-trans-type" : trans_type_str[ticket->t_trans_type-1]),
1724 ticket->t_trans_type,
1725 ticket->t_unit_res,
1726 ticket->t_curr_res,
1727 ticket->t_res_arr_sum, ticket->t_res_o_flow,
1728 ticket->t_res_num_ophdrs, ophdr_spc,
1729 ticket->t_res_arr_sum +
1730 ticket->t_res_o_flow + ophdr_spc,
1731 ticket->t_res_num);
1732
1733 for (i = 0; i < ticket->t_res_num; i++) {
1734 uint r_type = ticket->t_res_arr[i].r_type;
1735 xfs_warn(mp, "region[%u]: %s - %u bytes\n", i,
1736 ((r_type <= 0 || r_type > XLOG_REG_TYPE_MAX) ?
1737 "bad-rtype" : res_type_str[r_type-1]),
1738 ticket->t_res_arr[i].r_len);
1739 }
1740
1741 xfs_alert_tag(mp, XFS_PTAG_LOGRES,
1742 "xlog_write: reservation ran out. Need to up reservation");
1743 xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
1744}
1745
1746/*
1747 * Calculate the potential space needed by the log vector. Each region gets
1748 * its own xlog_op_header_t and may need to be double word aligned.
1749 */
1750static int
1751xlog_write_calc_vec_length(
1752 struct xlog_ticket *ticket,
1753 struct xfs_log_vec *log_vector)
1754{
1755 struct xfs_log_vec *lv;
1756 int headers = 0;
1757 int len = 0;
1758 int i;
1759
1760 /* acct for start rec of xact */
1761 if (ticket->t_flags & XLOG_TIC_INITED)
1762 headers++;
1763
1764 for (lv = log_vector; lv; lv = lv->lv_next) {
1765 headers += lv->lv_niovecs;
1766
1767 for (i = 0; i < lv->lv_niovecs; i++) {
1768 struct xfs_log_iovec *vecp = &lv->lv_iovecp[i];
1769
1770 len += vecp->i_len;
1771 xlog_tic_add_region(ticket, vecp->i_len, vecp->i_type);
1772 }
1773 }
1774
1775 ticket->t_res_num_ophdrs += headers;
1776 len += headers * sizeof(struct xlog_op_header);
1777
1778 return len;
1779}
1780
1781/*
1782 * If first write for transaction, insert start record We can't be trying to
1783 * commit if we are inited. We can't have any "partial_copy" if we are inited.
1784 */
1785static int
1786xlog_write_start_rec(
1787 struct xlog_op_header *ophdr,
1788 struct xlog_ticket *ticket)
1789{
1790 if (!(ticket->t_flags & XLOG_TIC_INITED))
1791 return 0;
1792
1793 ophdr->oh_tid = cpu_to_be32(ticket->t_tid);
1794 ophdr->oh_clientid = ticket->t_clientid;
1795 ophdr->oh_len = 0;
1796 ophdr->oh_flags = XLOG_START_TRANS;
1797 ophdr->oh_res2 = 0;
1798
1799 ticket->t_flags &= ~XLOG_TIC_INITED;
1800
1801 return sizeof(struct xlog_op_header);
1802}
1803
1804static xlog_op_header_t *
1805xlog_write_setup_ophdr(
1806 struct xlog *log,
1807 struct xlog_op_header *ophdr,
1808 struct xlog_ticket *ticket,
1809 uint flags)
1810{
1811 ophdr->oh_tid = cpu_to_be32(ticket->t_tid);
1812 ophdr->oh_clientid = ticket->t_clientid;
1813 ophdr->oh_res2 = 0;
1814
1815 /* are we copying a commit or unmount record? */
1816 ophdr->oh_flags = flags;
1817
1818 /*
1819 * We've seen logs corrupted with bad transaction client ids. This
1820 * makes sure that XFS doesn't generate them on. Turn this into an EIO
1821 * and shut down the filesystem.
1822 */
1823 switch (ophdr->oh_clientid) {
1824 case XFS_TRANSACTION:
1825 case XFS_VOLUME:
1826 case XFS_LOG:
1827 break;
1828 default:
1829 xfs_warn(log->l_mp,
1830 "Bad XFS transaction clientid 0x%x in ticket 0x%p",
1831 ophdr->oh_clientid, ticket);
1832 return NULL;
1833 }
1834
1835 return ophdr;
1836}
1837
1838/*
1839 * Set up the parameters of the region copy into the log. This has
1840 * to handle region write split across multiple log buffers - this
1841 * state is kept external to this function so that this code can
1842 * can be written in an obvious, self documenting manner.
1843 */
1844static int
1845xlog_write_setup_copy(
1846 struct xlog_ticket *ticket,
1847 struct xlog_op_header *ophdr,
1848 int space_available,
1849 int space_required,
1850 int *copy_off,
1851 int *copy_len,
1852 int *last_was_partial_copy,
1853 int *bytes_consumed)
1854{
1855 int still_to_copy;
1856
1857 still_to_copy = space_required - *bytes_consumed;
1858 *copy_off = *bytes_consumed;
1859
1860 if (still_to_copy <= space_available) {
1861 /* write of region completes here */
1862 *copy_len = still_to_copy;
1863 ophdr->oh_len = cpu_to_be32(*copy_len);
1864 if (*last_was_partial_copy)
1865 ophdr->oh_flags |= (XLOG_END_TRANS|XLOG_WAS_CONT_TRANS);
1866 *last_was_partial_copy = 0;
1867 *bytes_consumed = 0;
1868 return 0;
1869 }
1870
1871 /* partial write of region, needs extra log op header reservation */
1872 *copy_len = space_available;
1873 ophdr->oh_len = cpu_to_be32(*copy_len);
1874 ophdr->oh_flags |= XLOG_CONTINUE_TRANS;
1875 if (*last_was_partial_copy)
1876 ophdr->oh_flags |= XLOG_WAS_CONT_TRANS;
1877 *bytes_consumed += *copy_len;
1878 (*last_was_partial_copy)++;
1879
1880 /* account for new log op header */
1881 ticket->t_curr_res -= sizeof(struct xlog_op_header);
1882 ticket->t_res_num_ophdrs++;
1883
1884 return sizeof(struct xlog_op_header);
1885}
1886
1887static int
1888xlog_write_copy_finish(
1889 struct xlog *log,
1890 struct xlog_in_core *iclog,
1891 uint flags,
1892 int *record_cnt,
1893 int *data_cnt,
1894 int *partial_copy,
1895 int *partial_copy_len,
1896 int log_offset,
1897 struct xlog_in_core **commit_iclog)
1898{
1899 if (*partial_copy) {
1900 /*
1901 * This iclog has already been marked WANT_SYNC by
1902 * xlog_state_get_iclog_space.
1903 */
1904 xlog_state_finish_copy(log, iclog, *record_cnt, *data_cnt);
1905 *record_cnt = 0;
1906 *data_cnt = 0;
1907 return xlog_state_release_iclog(log, iclog);
1908 }
1909
1910 *partial_copy = 0;
1911 *partial_copy_len = 0;
1912
1913 if (iclog->ic_size - log_offset <= sizeof(xlog_op_header_t)) {
1914 /* no more space in this iclog - push it. */
1915 xlog_state_finish_copy(log, iclog, *record_cnt, *data_cnt);
1916 *record_cnt = 0;
1917 *data_cnt = 0;
1918
1919 spin_lock(&log->l_icloglock);
1920 xlog_state_want_sync(log, iclog);
1921 spin_unlock(&log->l_icloglock);
1922
1923 if (!commit_iclog)
1924 return xlog_state_release_iclog(log, iclog);
1925 ASSERT(flags & XLOG_COMMIT_TRANS);
1926 *commit_iclog = iclog;
1927 }
1928
1929 return 0;
1930}
1931
1932/*
1933 * Write some region out to in-core log
1934 *
1935 * This will be called when writing externally provided regions or when
1936 * writing out a commit record for a given transaction.
1937 *
1938 * General algorithm:
1939 * 1. Find total length of this write. This may include adding to the
1940 * lengths passed in.
1941 * 2. Check whether we violate the tickets reservation.
1942 * 3. While writing to this iclog
1943 * A. Reserve as much space in this iclog as can get
1944 * B. If this is first write, save away start lsn
1945 * C. While writing this region:
1946 * 1. If first write of transaction, write start record
1947 * 2. Write log operation header (header per region)
1948 * 3. Find out if we can fit entire region into this iclog
1949 * 4. Potentially, verify destination memcpy ptr
1950 * 5. Memcpy (partial) region
1951 * 6. If partial copy, release iclog; otherwise, continue
1952 * copying more regions into current iclog
1953 * 4. Mark want sync bit (in simulation mode)
1954 * 5. Release iclog for potential flush to on-disk log.
1955 *
1956 * ERRORS:
1957 * 1. Panic if reservation is overrun. This should never happen since
1958 * reservation amounts are generated internal to the filesystem.
1959 * NOTES:
1960 * 1. Tickets are single threaded data structures.
1961 * 2. The XLOG_END_TRANS & XLOG_CONTINUE_TRANS flags are passed down to the
1962 * syncing routine. When a single log_write region needs to span
1963 * multiple in-core logs, the XLOG_CONTINUE_TRANS bit should be set
1964 * on all log operation writes which don't contain the end of the
1965 * region. The XLOG_END_TRANS bit is used for the in-core log
1966 * operation which contains the end of the continued log_write region.
1967 * 3. When xlog_state_get_iclog_space() grabs the rest of the current iclog,
1968 * we don't really know exactly how much space will be used. As a result,
1969 * we don't update ic_offset until the end when we know exactly how many
1970 * bytes have been written out.
1971 */
1972int
1973xlog_write(
1974 struct xlog *log,
1975 struct xfs_log_vec *log_vector,
1976 struct xlog_ticket *ticket,
1977 xfs_lsn_t *start_lsn,
1978 struct xlog_in_core **commit_iclog,
1979 uint flags)
1980{
1981 struct xlog_in_core *iclog = NULL;
1982 struct xfs_log_iovec *vecp;
1983 struct xfs_log_vec *lv;
1984 int len;
1985 int index;
1986 int partial_copy = 0;
1987 int partial_copy_len = 0;
1988 int contwr = 0;
1989 int record_cnt = 0;
1990 int data_cnt = 0;
1991 int error;
1992
1993 *start_lsn = 0;
1994
1995 len = xlog_write_calc_vec_length(ticket, log_vector);
1996
1997 /*
1998 * Region headers and bytes are already accounted for.
1999 * We only need to take into account start records and
2000 * split regions in this function.
2001 */
2002 if (ticket->t_flags & XLOG_TIC_INITED)
2003 ticket->t_curr_res -= sizeof(xlog_op_header_t);
2004
2005 /*
2006 * Commit record headers need to be accounted for. These
2007 * come in as separate writes so are easy to detect.
2008 */
2009 if (flags & (XLOG_COMMIT_TRANS | XLOG_UNMOUNT_TRANS))
2010 ticket->t_curr_res -= sizeof(xlog_op_header_t);
2011
2012 if (ticket->t_curr_res < 0)
2013 xlog_print_tic_res(log->l_mp, ticket);
2014
2015 index = 0;
2016 lv = log_vector;
2017 vecp = lv->lv_iovecp;
2018 while (lv && index < lv->lv_niovecs) {
2019 void *ptr;
2020 int log_offset;
2021
2022 error = xlog_state_get_iclog_space(log, len, &iclog, ticket,
2023 &contwr, &log_offset);
2024 if (error)
2025 return error;
2026
2027 ASSERT(log_offset <= iclog->ic_size - 1);
2028 ptr = iclog->ic_datap + log_offset;
2029
2030 /* start_lsn is the first lsn written to. That's all we need. */
2031 if (!*start_lsn)
2032 *start_lsn = be64_to_cpu(iclog->ic_header.h_lsn);
2033
2034 /*
2035 * This loop writes out as many regions as can fit in the amount
2036 * of space which was allocated by xlog_state_get_iclog_space().
2037 */
2038 while (lv && index < lv->lv_niovecs) {
2039 struct xfs_log_iovec *reg = &vecp[index];
2040 struct xlog_op_header *ophdr;
2041 int start_rec_copy;
2042 int copy_len;
2043 int copy_off;
2044
2045 ASSERT(reg->i_len % sizeof(__int32_t) == 0);
2046 ASSERT((unsigned long)ptr % sizeof(__int32_t) == 0);
2047
2048 start_rec_copy = xlog_write_start_rec(ptr, ticket);
2049 if (start_rec_copy) {
2050 record_cnt++;
2051 xlog_write_adv_cnt(&ptr, &len, &log_offset,
2052 start_rec_copy);
2053 }
2054
2055 ophdr = xlog_write_setup_ophdr(log, ptr, ticket, flags);
2056 if (!ophdr)
2057 return XFS_ERROR(EIO);
2058
2059 xlog_write_adv_cnt(&ptr, &len, &log_offset,
2060 sizeof(struct xlog_op_header));
2061
2062 len += xlog_write_setup_copy(ticket, ophdr,
2063 iclog->ic_size-log_offset,
2064 reg->i_len,
2065 ©_off, ©_len,
2066 &partial_copy,
2067 &partial_copy_len);
2068 xlog_verify_dest_ptr(log, ptr);
2069
2070 /* copy region */
2071 ASSERT(copy_len >= 0);
2072 memcpy(ptr, reg->i_addr + copy_off, copy_len);
2073 xlog_write_adv_cnt(&ptr, &len, &log_offset, copy_len);
2074
2075 copy_len += start_rec_copy + sizeof(xlog_op_header_t);
2076 record_cnt++;
2077 data_cnt += contwr ? copy_len : 0;
2078
2079 error = xlog_write_copy_finish(log, iclog, flags,
2080 &record_cnt, &data_cnt,
2081 &partial_copy,
2082 &partial_copy_len,
2083 log_offset,
2084 commit_iclog);
2085 if (error)
2086 return error;
2087
2088 /*
2089 * if we had a partial copy, we need to get more iclog
2090 * space but we don't want to increment the region
2091 * index because there is still more is this region to
2092 * write.
2093 *
2094 * If we completed writing this region, and we flushed
2095 * the iclog (indicated by resetting of the record
2096 * count), then we also need to get more log space. If
2097 * this was the last record, though, we are done and
2098 * can just return.
2099 */
2100 if (partial_copy)
2101 break;
2102
2103 if (++index == lv->lv_niovecs) {
2104 lv = lv->lv_next;
2105 index = 0;
2106 if (lv)
2107 vecp = lv->lv_iovecp;
2108 }
2109 if (record_cnt == 0) {
2110 if (!lv)
2111 return 0;
2112 break;
2113 }
2114 }
2115 }
2116
2117 ASSERT(len == 0);
2118
2119 xlog_state_finish_copy(log, iclog, record_cnt, data_cnt);
2120 if (!commit_iclog)
2121 return xlog_state_release_iclog(log, iclog);
2122
2123 ASSERT(flags & XLOG_COMMIT_TRANS);
2124 *commit_iclog = iclog;
2125 return 0;
2126}
2127
2128
2129/*****************************************************************************
2130 *
2131 * State Machine functions
2132 *
2133 *****************************************************************************
2134 */
2135
2136/* Clean iclogs starting from the head. This ordering must be
2137 * maintained, so an iclog doesn't become ACTIVE beyond one that
2138 * is SYNCING. This is also required to maintain the notion that we use
2139 * a ordered wait queue to hold off would be writers to the log when every
2140 * iclog is trying to sync to disk.
2141 *
2142 * State Change: DIRTY -> ACTIVE
2143 */
2144STATIC void
2145xlog_state_clean_log(xlog_t *log)
2146{
2147 xlog_in_core_t *iclog;
2148 int changed = 0;
2149
2150 iclog = log->l_iclog;
2151 do {
2152 if (iclog->ic_state == XLOG_STATE_DIRTY) {
2153 iclog->ic_state = XLOG_STATE_ACTIVE;
2154 iclog->ic_offset = 0;
2155 ASSERT(iclog->ic_callback == NULL);
2156 /*
2157 * If the number of ops in this iclog indicate it just
2158 * contains the dummy transaction, we can
2159 * change state into IDLE (the second time around).
2160 * Otherwise we should change the state into
2161 * NEED a dummy.
2162 * We don't need to cover the dummy.
2163 */
2164 if (!changed &&
2165 (be32_to_cpu(iclog->ic_header.h_num_logops) ==
2166 XLOG_COVER_OPS)) {
2167 changed = 1;
2168 } else {
2169 /*
2170 * We have two dirty iclogs so start over
2171 * This could also be num of ops indicates
2172 * this is not the dummy going out.
2173 */
2174 changed = 2;
2175 }
2176 iclog->ic_header.h_num_logops = 0;
2177 memset(iclog->ic_header.h_cycle_data, 0,
2178 sizeof(iclog->ic_header.h_cycle_data));
2179 iclog->ic_header.h_lsn = 0;
2180 } else if (iclog->ic_state == XLOG_STATE_ACTIVE)
2181 /* do nothing */;
2182 else
2183 break; /* stop cleaning */
2184 iclog = iclog->ic_next;
2185 } while (iclog != log->l_iclog);
2186
2187 /* log is locked when we are called */
2188 /*
2189 * Change state for the dummy log recording.
2190 * We usually go to NEED. But we go to NEED2 if the changed indicates
2191 * we are done writing the dummy record.
2192 * If we are done with the second dummy recored (DONE2), then
2193 * we go to IDLE.
2194 */
2195 if (changed) {
2196 switch (log->l_covered_state) {
2197 case XLOG_STATE_COVER_IDLE:
2198 case XLOG_STATE_COVER_NEED:
2199 case XLOG_STATE_COVER_NEED2:
2200 log->l_covered_state = XLOG_STATE_COVER_NEED;
2201 break;
2202
2203 case XLOG_STATE_COVER_DONE:
2204 if (changed == 1)
2205 log->l_covered_state = XLOG_STATE_COVER_NEED2;
2206 else
2207 log->l_covered_state = XLOG_STATE_COVER_NEED;
2208 break;
2209
2210 case XLOG_STATE_COVER_DONE2:
2211 if (changed == 1)
2212 log->l_covered_state = XLOG_STATE_COVER_IDLE;
2213 else
2214 log->l_covered_state = XLOG_STATE_COVER_NEED;
2215 break;
2216
2217 default:
2218 ASSERT(0);
2219 }
2220 }
2221} /* xlog_state_clean_log */
2222
2223STATIC xfs_lsn_t
2224xlog_get_lowest_lsn(
2225 xlog_t *log)
2226{
2227 xlog_in_core_t *lsn_log;
2228 xfs_lsn_t lowest_lsn, lsn;
2229
2230 lsn_log = log->l_iclog;
2231 lowest_lsn = 0;
2232 do {
2233 if (!(lsn_log->ic_state & (XLOG_STATE_ACTIVE|XLOG_STATE_DIRTY))) {
2234 lsn = be64_to_cpu(lsn_log->ic_header.h_lsn);
2235 if ((lsn && !lowest_lsn) ||
2236 (XFS_LSN_CMP(lsn, lowest_lsn) < 0)) {
2237 lowest_lsn = lsn;
2238 }
2239 }
2240 lsn_log = lsn_log->ic_next;
2241 } while (lsn_log != log->l_iclog);
2242 return lowest_lsn;
2243}
2244
2245
2246STATIC void
2247xlog_state_do_callback(
2248 xlog_t *log,
2249 int aborted,
2250 xlog_in_core_t *ciclog)
2251{
2252 xlog_in_core_t *iclog;
2253 xlog_in_core_t *first_iclog; /* used to know when we've
2254 * processed all iclogs once */
2255 xfs_log_callback_t *cb, *cb_next;
2256 int flushcnt = 0;
2257 xfs_lsn_t lowest_lsn;
2258 int ioerrors; /* counter: iclogs with errors */
2259 int loopdidcallbacks; /* flag: inner loop did callbacks*/
2260 int funcdidcallbacks; /* flag: function did callbacks */
2261 int repeats; /* for issuing console warnings if
2262 * looping too many times */
2263 int wake = 0;
2264
2265 spin_lock(&log->l_icloglock);
2266 first_iclog = iclog = log->l_iclog;
2267 ioerrors = 0;
2268 funcdidcallbacks = 0;
2269 repeats = 0;
2270
2271 do {
2272 /*
2273 * Scan all iclogs starting with the one pointed to by the
2274 * log. Reset this starting point each time the log is
2275 * unlocked (during callbacks).
2276 *
2277 * Keep looping through iclogs until one full pass is made
2278 * without running any callbacks.
2279 */
2280 first_iclog = log->l_iclog;
2281 iclog = log->l_iclog;
2282 loopdidcallbacks = 0;
2283 repeats++;
2284
2285 do {
2286
2287 /* skip all iclogs in the ACTIVE & DIRTY states */
2288 if (iclog->ic_state &
2289 (XLOG_STATE_ACTIVE|XLOG_STATE_DIRTY)) {
2290 iclog = iclog->ic_next;
2291 continue;
2292 }
2293
2294 /*
2295 * Between marking a filesystem SHUTDOWN and stopping
2296 * the log, we do flush all iclogs to disk (if there
2297 * wasn't a log I/O error). So, we do want things to
2298 * go smoothly in case of just a SHUTDOWN w/o a
2299 * LOG_IO_ERROR.
2300 */
2301 if (!(iclog->ic_state & XLOG_STATE_IOERROR)) {
2302 /*
2303 * Can only perform callbacks in order. Since
2304 * this iclog is not in the DONE_SYNC/
2305 * DO_CALLBACK state, we skip the rest and
2306 * just try to clean up. If we set our iclog
2307 * to DO_CALLBACK, we will not process it when
2308 * we retry since a previous iclog is in the
2309 * CALLBACK and the state cannot change since
2310 * we are holding the l_icloglock.
2311 */
2312 if (!(iclog->ic_state &
2313 (XLOG_STATE_DONE_SYNC |
2314 XLOG_STATE_DO_CALLBACK))) {
2315 if (ciclog && (ciclog->ic_state ==
2316 XLOG_STATE_DONE_SYNC)) {
2317 ciclog->ic_state = XLOG_STATE_DO_CALLBACK;
2318 }
2319 break;
2320 }
2321 /*
2322 * We now have an iclog that is in either the
2323 * DO_CALLBACK or DONE_SYNC states. The other
2324 * states (WANT_SYNC, SYNCING, or CALLBACK were
2325 * caught by the above if and are going to
2326 * clean (i.e. we aren't doing their callbacks)
2327 * see the above if.
2328 */
2329
2330 /*
2331 * We will do one more check here to see if we
2332 * have chased our tail around.
2333 */
2334
2335 lowest_lsn = xlog_get_lowest_lsn(log);
2336 if (lowest_lsn &&
2337 XFS_LSN_CMP(lowest_lsn,
2338 be64_to_cpu(iclog->ic_header.h_lsn)) < 0) {
2339 iclog = iclog->ic_next;
2340 continue; /* Leave this iclog for
2341 * another thread */
2342 }
2343
2344 iclog->ic_state = XLOG_STATE_CALLBACK;
2345
2346
2347 /*
2348 * update the last_sync_lsn before we drop the
2349 * icloglock to ensure we are the only one that
2350 * can update it.
2351 */
2352 ASSERT(XFS_LSN_CMP(atomic64_read(&log->l_last_sync_lsn),
2353 be64_to_cpu(iclog->ic_header.h_lsn)) <= 0);
2354 atomic64_set(&log->l_last_sync_lsn,
2355 be64_to_cpu(iclog->ic_header.h_lsn));
2356
2357 } else
2358 ioerrors++;
2359
2360 spin_unlock(&log->l_icloglock);
2361
2362 /*
2363 * Keep processing entries in the callback list until
2364 * we come around and it is empty. We need to
2365 * atomically see that the list is empty and change the
2366 * state to DIRTY so that we don't miss any more
2367 * callbacks being added.
2368 */
2369 spin_lock(&iclog->ic_callback_lock);
2370 cb = iclog->ic_callback;
2371 while (cb) {
2372 iclog->ic_callback_tail = &(iclog->ic_callback);
2373 iclog->ic_callback = NULL;
2374 spin_unlock(&iclog->ic_callback_lock);
2375
2376 /* perform callbacks in the order given */
2377 for (; cb; cb = cb_next) {
2378 cb_next = cb->cb_next;
2379 cb->cb_func(cb->cb_arg, aborted);
2380 }
2381 spin_lock(&iclog->ic_callback_lock);
2382 cb = iclog->ic_callback;
2383 }
2384
2385 loopdidcallbacks++;
2386 funcdidcallbacks++;
2387
2388 spin_lock(&log->l_icloglock);
2389 ASSERT(iclog->ic_callback == NULL);
2390 spin_unlock(&iclog->ic_callback_lock);
2391 if (!(iclog->ic_state & XLOG_STATE_IOERROR))
2392 iclog->ic_state = XLOG_STATE_DIRTY;
2393
2394 /*
2395 * Transition from DIRTY to ACTIVE if applicable.
2396 * NOP if STATE_IOERROR.
2397 */
2398 xlog_state_clean_log(log);
2399
2400 /* wake up threads waiting in xfs_log_force() */
2401 wake_up_all(&iclog->ic_force_wait);
2402
2403 iclog = iclog->ic_next;
2404 } while (first_iclog != iclog);
2405
2406 if (repeats > 5000) {
2407 flushcnt += repeats;
2408 repeats = 0;
2409 xfs_warn(log->l_mp,
2410 "%s: possible infinite loop (%d iterations)",
2411 __func__, flushcnt);
2412 }
2413 } while (!ioerrors && loopdidcallbacks);
2414
2415 /*
2416 * make one last gasp attempt to see if iclogs are being left in
2417 * limbo..
2418 */
2419#ifdef DEBUG
2420 if (funcdidcallbacks) {
2421 first_iclog = iclog = log->l_iclog;
2422 do {
2423 ASSERT(iclog->ic_state != XLOG_STATE_DO_CALLBACK);
2424 /*
2425 * Terminate the loop if iclogs are found in states
2426 * which will cause other threads to clean up iclogs.
2427 *
2428 * SYNCING - i/o completion will go through logs
2429 * DONE_SYNC - interrupt thread should be waiting for
2430 * l_icloglock
2431 * IOERROR - give up hope all ye who enter here
2432 */
2433 if (iclog->ic_state == XLOG_STATE_WANT_SYNC ||
2434 iclog->ic_state == XLOG_STATE_SYNCING ||
2435 iclog->ic_state == XLOG_STATE_DONE_SYNC ||
2436 iclog->ic_state == XLOG_STATE_IOERROR )
2437 break;
2438 iclog = iclog->ic_next;
2439 } while (first_iclog != iclog);
2440 }
2441#endif
2442
2443 if (log->l_iclog->ic_state & (XLOG_STATE_ACTIVE|XLOG_STATE_IOERROR))
2444 wake = 1;
2445 spin_unlock(&log->l_icloglock);
2446
2447 if (wake)
2448 wake_up_all(&log->l_flush_wait);
2449}
2450
2451
2452/*
2453 * Finish transitioning this iclog to the dirty state.
2454 *
2455 * Make sure that we completely execute this routine only when this is
2456 * the last call to the iclog. There is a good chance that iclog flushes,
2457 * when we reach the end of the physical log, get turned into 2 separate
2458 * calls to bwrite. Hence, one iclog flush could generate two calls to this
2459 * routine. By using the reference count bwritecnt, we guarantee that only
2460 * the second completion goes through.
2461 *
2462 * Callbacks could take time, so they are done outside the scope of the
2463 * global state machine log lock.
2464 */
2465STATIC void
2466xlog_state_done_syncing(
2467 xlog_in_core_t *iclog,
2468 int aborted)
2469{
2470 xlog_t *log = iclog->ic_log;
2471
2472 spin_lock(&log->l_icloglock);
2473
2474 ASSERT(iclog->ic_state == XLOG_STATE_SYNCING ||
2475 iclog->ic_state == XLOG_STATE_IOERROR);
2476 ASSERT(atomic_read(&iclog->ic_refcnt) == 0);
2477 ASSERT(iclog->ic_bwritecnt == 1 || iclog->ic_bwritecnt == 2);
2478
2479
2480 /*
2481 * If we got an error, either on the first buffer, or in the case of
2482 * split log writes, on the second, we mark ALL iclogs STATE_IOERROR,
2483 * and none should ever be attempted to be written to disk
2484 * again.
2485 */
2486 if (iclog->ic_state != XLOG_STATE_IOERROR) {
2487 if (--iclog->ic_bwritecnt == 1) {
2488 spin_unlock(&log->l_icloglock);
2489 return;
2490 }
2491 iclog->ic_state = XLOG_STATE_DONE_SYNC;
2492 }
2493
2494 /*
2495 * Someone could be sleeping prior to writing out the next
2496 * iclog buffer, we wake them all, one will get to do the
2497 * I/O, the others get to wait for the result.
2498 */
2499 wake_up_all(&iclog->ic_write_wait);
2500 spin_unlock(&log->l_icloglock);
2501 xlog_state_do_callback(log, aborted, iclog); /* also cleans log */
2502} /* xlog_state_done_syncing */
2503
2504
2505/*
2506 * If the head of the in-core log ring is not (ACTIVE or DIRTY), then we must
2507 * sleep. We wait on the flush queue on the head iclog as that should be
2508 * the first iclog to complete flushing. Hence if all iclogs are syncing,
2509 * we will wait here and all new writes will sleep until a sync completes.
2510 *
2511 * The in-core logs are used in a circular fashion. They are not used
2512 * out-of-order even when an iclog past the head is free.
2513 *
2514 * return:
2515 * * log_offset where xlog_write() can start writing into the in-core
2516 * log's data space.
2517 * * in-core log pointer to which xlog_write() should write.
2518 * * boolean indicating this is a continued write to an in-core log.
2519 * If this is the last write, then the in-core log's offset field
2520 * needs to be incremented, depending on the amount of data which
2521 * is copied.
2522 */
2523STATIC int
2524xlog_state_get_iclog_space(xlog_t *log,
2525 int len,
2526 xlog_in_core_t **iclogp,
2527 xlog_ticket_t *ticket,
2528 int *continued_write,
2529 int *logoffsetp)
2530{
2531 int log_offset;
2532 xlog_rec_header_t *head;
2533 xlog_in_core_t *iclog;
2534 int error;
2535
2536restart:
2537 spin_lock(&log->l_icloglock);
2538 if (XLOG_FORCED_SHUTDOWN(log)) {
2539 spin_unlock(&log->l_icloglock);
2540 return XFS_ERROR(EIO);
2541 }
2542
2543 iclog = log->l_iclog;
2544 if (iclog->ic_state != XLOG_STATE_ACTIVE) {
2545 XFS_STATS_INC(xs_log_noiclogs);
2546
2547 /* Wait for log writes to have flushed */
2548 xlog_wait(&log->l_flush_wait, &log->l_icloglock);
2549 goto restart;
2550 }
2551
2552 head = &iclog->ic_header;
2553
2554 atomic_inc(&iclog->ic_refcnt); /* prevents sync */
2555 log_offset = iclog->ic_offset;
2556
2557 /* On the 1st write to an iclog, figure out lsn. This works
2558 * if iclogs marked XLOG_STATE_WANT_SYNC always write out what they are
2559 * committing to. If the offset is set, that's how many blocks
2560 * must be written.
2561 */
2562 if (log_offset == 0) {
2563 ticket->t_curr_res -= log->l_iclog_hsize;
2564 xlog_tic_add_region(ticket,
2565 log->l_iclog_hsize,
2566 XLOG_REG_TYPE_LRHEADER);
2567 head->h_cycle = cpu_to_be32(log->l_curr_cycle);
2568 head->h_lsn = cpu_to_be64(
2569 xlog_assign_lsn(log->l_curr_cycle, log->l_curr_block));
2570 ASSERT(log->l_curr_block >= 0);
2571 }
2572
2573 /* If there is enough room to write everything, then do it. Otherwise,
2574 * claim the rest of the region and make sure the XLOG_STATE_WANT_SYNC
2575 * bit is on, so this will get flushed out. Don't update ic_offset
2576 * until you know exactly how many bytes get copied. Therefore, wait
2577 * until later to update ic_offset.
2578 *
2579 * xlog_write() algorithm assumes that at least 2 xlog_op_header_t's
2580 * can fit into remaining data section.
2581 */
2582 if (iclog->ic_size - iclog->ic_offset < 2*sizeof(xlog_op_header_t)) {
2583 xlog_state_switch_iclogs(log, iclog, iclog->ic_size);
2584
2585 /*
2586 * If I'm the only one writing to this iclog, sync it to disk.
2587 * We need to do an atomic compare and decrement here to avoid
2588 * racing with concurrent atomic_dec_and_lock() calls in
2589 * xlog_state_release_iclog() when there is more than one
2590 * reference to the iclog.
2591 */
2592 if (!atomic_add_unless(&iclog->ic_refcnt, -1, 1)) {
2593 /* we are the only one */
2594 spin_unlock(&log->l_icloglock);
2595 error = xlog_state_release_iclog(log, iclog);
2596 if (error)
2597 return error;
2598 } else {
2599 spin_unlock(&log->l_icloglock);
2600 }
2601 goto restart;
2602 }
2603
2604 /* Do we have enough room to write the full amount in the remainder
2605 * of this iclog? Or must we continue a write on the next iclog and
2606 * mark this iclog as completely taken? In the case where we switch
2607 * iclogs (to mark it taken), this particular iclog will release/sync
2608 * to disk in xlog_write().
2609 */
2610 if (len <= iclog->ic_size - iclog->ic_offset) {
2611 *continued_write = 0;
2612 iclog->ic_offset += len;
2613 } else {
2614 *continued_write = 1;
2615 xlog_state_switch_iclogs(log, iclog, iclog->ic_size);
2616 }
2617 *iclogp = iclog;
2618
2619 ASSERT(iclog->ic_offset <= iclog->ic_size);
2620 spin_unlock(&log->l_icloglock);
2621
2622 *logoffsetp = log_offset;
2623 return 0;
2624} /* xlog_state_get_iclog_space */
2625
2626/* The first cnt-1 times through here we don't need to
2627 * move the grant write head because the permanent
2628 * reservation has reserved cnt times the unit amount.
2629 * Release part of current permanent unit reservation and
2630 * reset current reservation to be one units worth. Also
2631 * move grant reservation head forward.
2632 */
2633STATIC void
2634xlog_regrant_reserve_log_space(xlog_t *log,
2635 xlog_ticket_t *ticket)
2636{
2637 trace_xfs_log_regrant_reserve_enter(log, ticket);
2638
2639 if (ticket->t_cnt > 0)
2640 ticket->t_cnt--;
2641
2642 xlog_grant_sub_space(log, &log->l_reserve_head.grant,
2643 ticket->t_curr_res);
2644 xlog_grant_sub_space(log, &log->l_write_head.grant,
2645 ticket->t_curr_res);
2646 ticket->t_curr_res = ticket->t_unit_res;
2647 xlog_tic_reset_res(ticket);
2648
2649 trace_xfs_log_regrant_reserve_sub(log, ticket);
2650
2651 /* just return if we still have some of the pre-reserved space */
2652 if (ticket->t_cnt > 0)
2653 return;
2654
2655 xlog_grant_add_space(log, &log->l_reserve_head.grant,
2656 ticket->t_unit_res);
2657
2658 trace_xfs_log_regrant_reserve_exit(log, ticket);
2659
2660 ticket->t_curr_res = ticket->t_unit_res;
2661 xlog_tic_reset_res(ticket);
2662} /* xlog_regrant_reserve_log_space */
2663
2664
2665/*
2666 * Give back the space left from a reservation.
2667 *
2668 * All the information we need to make a correct determination of space left
2669 * is present. For non-permanent reservations, things are quite easy. The
2670 * count should have been decremented to zero. We only need to deal with the
2671 * space remaining in the current reservation part of the ticket. If the
2672 * ticket contains a permanent reservation, there may be left over space which
2673 * needs to be released. A count of N means that N-1 refills of the current
2674 * reservation can be done before we need to ask for more space. The first
2675 * one goes to fill up the first current reservation. Once we run out of
2676 * space, the count will stay at zero and the only space remaining will be
2677 * in the current reservation field.
2678 */
2679STATIC void
2680xlog_ungrant_log_space(xlog_t *log,
2681 xlog_ticket_t *ticket)
2682{
2683 int bytes;
2684
2685 if (ticket->t_cnt > 0)
2686 ticket->t_cnt--;
2687
2688 trace_xfs_log_ungrant_enter(log, ticket);
2689 trace_xfs_log_ungrant_sub(log, ticket);
2690
2691 /*
2692 * If this is a permanent reservation ticket, we may be able to free
2693 * up more space based on the remaining count.
2694 */
2695 bytes = ticket->t_curr_res;
2696 if (ticket->t_cnt > 0) {
2697 ASSERT(ticket->t_flags & XLOG_TIC_PERM_RESERV);
2698 bytes += ticket->t_unit_res*ticket->t_cnt;
2699 }
2700
2701 xlog_grant_sub_space(log, &log->l_reserve_head.grant, bytes);
2702 xlog_grant_sub_space(log, &log->l_write_head.grant, bytes);
2703
2704 trace_xfs_log_ungrant_exit(log, ticket);
2705
2706 xfs_log_space_wake(log->l_mp);
2707}
2708
2709/*
2710 * Flush iclog to disk if this is the last reference to the given iclog and
2711 * the WANT_SYNC bit is set.
2712 *
2713 * When this function is entered, the iclog is not necessarily in the
2714 * WANT_SYNC state. It may be sitting around waiting to get filled.
2715 *
2716 *
2717 */
2718STATIC int
2719xlog_state_release_iclog(
2720 xlog_t *log,
2721 xlog_in_core_t *iclog)
2722{
2723 int sync = 0; /* do we sync? */
2724
2725 if (iclog->ic_state & XLOG_STATE_IOERROR)
2726 return XFS_ERROR(EIO);
2727
2728 ASSERT(atomic_read(&iclog->ic_refcnt) > 0);
2729 if (!atomic_dec_and_lock(&iclog->ic_refcnt, &log->l_icloglock))
2730 return 0;
2731
2732 if (iclog->ic_state & XLOG_STATE_IOERROR) {
2733 spin_unlock(&log->l_icloglock);
2734 return XFS_ERROR(EIO);
2735 }
2736 ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE ||
2737 iclog->ic_state == XLOG_STATE_WANT_SYNC);
2738
2739 if (iclog->ic_state == XLOG_STATE_WANT_SYNC) {
2740 /* update tail before writing to iclog */
2741 xfs_lsn_t tail_lsn = xlog_assign_tail_lsn(log->l_mp);
2742 sync++;
2743 iclog->ic_state = XLOG_STATE_SYNCING;
2744 iclog->ic_header.h_tail_lsn = cpu_to_be64(tail_lsn);
2745 xlog_verify_tail_lsn(log, iclog, tail_lsn);
2746 /* cycle incremented when incrementing curr_block */
2747 }
2748 spin_unlock(&log->l_icloglock);
2749
2750 /*
2751 * We let the log lock go, so it's possible that we hit a log I/O
2752 * error or some other SHUTDOWN condition that marks the iclog
2753 * as XLOG_STATE_IOERROR before the bwrite. However, we know that
2754 * this iclog has consistent data, so we ignore IOERROR
2755 * flags after this point.
2756 */
2757 if (sync)
2758 return xlog_sync(log, iclog);
2759 return 0;
2760} /* xlog_state_release_iclog */
2761
2762
2763/*
2764 * This routine will mark the current iclog in the ring as WANT_SYNC
2765 * and move the current iclog pointer to the next iclog in the ring.
2766 * When this routine is called from xlog_state_get_iclog_space(), the
2767 * exact size of the iclog has not yet been determined. All we know is
2768 * that every data block. We have run out of space in this log record.
2769 */
2770STATIC void
2771xlog_state_switch_iclogs(xlog_t *log,
2772 xlog_in_core_t *iclog,
2773 int eventual_size)
2774{
2775 ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE);
2776 if (!eventual_size)
2777 eventual_size = iclog->ic_offset;
2778 iclog->ic_state = XLOG_STATE_WANT_SYNC;
2779 iclog->ic_header.h_prev_block = cpu_to_be32(log->l_prev_block);
2780 log->l_prev_block = log->l_curr_block;
2781 log->l_prev_cycle = log->l_curr_cycle;
2782
2783 /* roll log?: ic_offset changed later */
2784 log->l_curr_block += BTOBB(eventual_size)+BTOBB(log->l_iclog_hsize);
2785
2786 /* Round up to next log-sunit */
2787 if (xfs_sb_version_haslogv2(&log->l_mp->m_sb) &&
2788 log->l_mp->m_sb.sb_logsunit > 1) {
2789 __uint32_t sunit_bb = BTOBB(log->l_mp->m_sb.sb_logsunit);
2790 log->l_curr_block = roundup(log->l_curr_block, sunit_bb);
2791 }
2792
2793 if (log->l_curr_block >= log->l_logBBsize) {
2794 log->l_curr_cycle++;
2795 if (log->l_curr_cycle == XLOG_HEADER_MAGIC_NUM)
2796 log->l_curr_cycle++;
2797 log->l_curr_block -= log->l_logBBsize;
2798 ASSERT(log->l_curr_block >= 0);
2799 }
2800 ASSERT(iclog == log->l_iclog);
2801 log->l_iclog = iclog->ic_next;
2802} /* xlog_state_switch_iclogs */
2803
2804/*
2805 * Write out all data in the in-core log as of this exact moment in time.
2806 *
2807 * Data may be written to the in-core log during this call. However,
2808 * we don't guarantee this data will be written out. A change from past
2809 * implementation means this routine will *not* write out zero length LRs.
2810 *
2811 * Basically, we try and perform an intelligent scan of the in-core logs.
2812 * If we determine there is no flushable data, we just return. There is no
2813 * flushable data if:
2814 *
2815 * 1. the current iclog is active and has no data; the previous iclog
2816 * is in the active or dirty state.
2817 * 2. the current iclog is drity, and the previous iclog is in the
2818 * active or dirty state.
2819 *
2820 * We may sleep if:
2821 *
2822 * 1. the current iclog is not in the active nor dirty state.
2823 * 2. the current iclog dirty, and the previous iclog is not in the
2824 * active nor dirty state.
2825 * 3. the current iclog is active, and there is another thread writing
2826 * to this particular iclog.
2827 * 4. a) the current iclog is active and has no other writers
2828 * b) when we return from flushing out this iclog, it is still
2829 * not in the active nor dirty state.
2830 */
2831int
2832_xfs_log_force(
2833 struct xfs_mount *mp,
2834 uint flags,
2835 int *log_flushed)
2836{
2837 struct xlog *log = mp->m_log;
2838 struct xlog_in_core *iclog;
2839 xfs_lsn_t lsn;
2840
2841 XFS_STATS_INC(xs_log_force);
2842
2843 xlog_cil_force(log);
2844
2845 spin_lock(&log->l_icloglock);
2846
2847 iclog = log->l_iclog;
2848 if (iclog->ic_state & XLOG_STATE_IOERROR) {
2849 spin_unlock(&log->l_icloglock);
2850 return XFS_ERROR(EIO);
2851 }
2852
2853 /* If the head iclog is not active nor dirty, we just attach
2854 * ourselves to the head and go to sleep.
2855 */
2856 if (iclog->ic_state == XLOG_STATE_ACTIVE ||
2857 iclog->ic_state == XLOG_STATE_DIRTY) {
2858 /*
2859 * If the head is dirty or (active and empty), then
2860 * we need to look at the previous iclog. If the previous
2861 * iclog is active or dirty we are done. There is nothing
2862 * to sync out. Otherwise, we attach ourselves to the
2863 * previous iclog and go to sleep.
2864 */
2865 if (iclog->ic_state == XLOG_STATE_DIRTY ||
2866 (atomic_read(&iclog->ic_refcnt) == 0
2867 && iclog->ic_offset == 0)) {
2868 iclog = iclog->ic_prev;
2869 if (iclog->ic_state == XLOG_STATE_ACTIVE ||
2870 iclog->ic_state == XLOG_STATE_DIRTY)
2871 goto no_sleep;
2872 else
2873 goto maybe_sleep;
2874 } else {
2875 if (atomic_read(&iclog->ic_refcnt) == 0) {
2876 /* We are the only one with access to this
2877 * iclog. Flush it out now. There should
2878 * be a roundoff of zero to show that someone
2879 * has already taken care of the roundoff from
2880 * the previous sync.
2881 */
2882 atomic_inc(&iclog->ic_refcnt);
2883 lsn = be64_to_cpu(iclog->ic_header.h_lsn);
2884 xlog_state_switch_iclogs(log, iclog, 0);
2885 spin_unlock(&log->l_icloglock);
2886
2887 if (xlog_state_release_iclog(log, iclog))
2888 return XFS_ERROR(EIO);
2889
2890 if (log_flushed)
2891 *log_flushed = 1;
2892 spin_lock(&log->l_icloglock);
2893 if (be64_to_cpu(iclog->ic_header.h_lsn) == lsn &&
2894 iclog->ic_state != XLOG_STATE_DIRTY)
2895 goto maybe_sleep;
2896 else
2897 goto no_sleep;
2898 } else {
2899 /* Someone else is writing to this iclog.
2900 * Use its call to flush out the data. However,
2901 * the other thread may not force out this LR,
2902 * so we mark it WANT_SYNC.
2903 */
2904 xlog_state_switch_iclogs(log, iclog, 0);
2905 goto maybe_sleep;
2906 }
2907 }
2908 }
2909
2910 /* By the time we come around again, the iclog could've been filled
2911 * which would give it another lsn. If we have a new lsn, just
2912 * return because the relevant data has been flushed.
2913 */
2914maybe_sleep:
2915 if (flags & XFS_LOG_SYNC) {
2916 /*
2917 * We must check if we're shutting down here, before
2918 * we wait, while we're holding the l_icloglock.
2919 * Then we check again after waking up, in case our
2920 * sleep was disturbed by a bad news.
2921 */
2922 if (iclog->ic_state & XLOG_STATE_IOERROR) {
2923 spin_unlock(&log->l_icloglock);
2924 return XFS_ERROR(EIO);
2925 }
2926 XFS_STATS_INC(xs_log_force_sleep);
2927 xlog_wait(&iclog->ic_force_wait, &log->l_icloglock);
2928 /*
2929 * No need to grab the log lock here since we're
2930 * only deciding whether or not to return EIO
2931 * and the memory read should be atomic.
2932 */
2933 if (iclog->ic_state & XLOG_STATE_IOERROR)
2934 return XFS_ERROR(EIO);
2935 if (log_flushed)
2936 *log_flushed = 1;
2937 } else {
2938
2939no_sleep:
2940 spin_unlock(&log->l_icloglock);
2941 }
2942 return 0;
2943}
2944
2945/*
2946 * Wrapper for _xfs_log_force(), to be used when caller doesn't care
2947 * about errors or whether the log was flushed or not. This is the normal
2948 * interface to use when trying to unpin items or move the log forward.
2949 */
2950void
2951xfs_log_force(
2952 xfs_mount_t *mp,
2953 uint flags)
2954{
2955 int error;
2956
2957 trace_xfs_log_force(mp, 0);
2958 error = _xfs_log_force(mp, flags, NULL);
2959 if (error)
2960 xfs_warn(mp, "%s: error %d returned.", __func__, error);
2961}
2962
2963/*
2964 * Force the in-core log to disk for a specific LSN.
2965 *
2966 * Find in-core log with lsn.
2967 * If it is in the DIRTY state, just return.
2968 * If it is in the ACTIVE state, move the in-core log into the WANT_SYNC
2969 * state and go to sleep or return.
2970 * If it is in any other state, go to sleep or return.
2971 *
2972 * Synchronous forces are implemented with a signal variable. All callers
2973 * to force a given lsn to disk will wait on a the sv attached to the
2974 * specific in-core log. When given in-core log finally completes its
2975 * write to disk, that thread will wake up all threads waiting on the
2976 * sv.
2977 */
2978int
2979_xfs_log_force_lsn(
2980 struct xfs_mount *mp,
2981 xfs_lsn_t lsn,
2982 uint flags,
2983 int *log_flushed)
2984{
2985 struct xlog *log = mp->m_log;
2986 struct xlog_in_core *iclog;
2987 int already_slept = 0;
2988
2989 ASSERT(lsn != 0);
2990
2991 XFS_STATS_INC(xs_log_force);
2992
2993 lsn = xlog_cil_force_lsn(log, lsn);
2994 if (lsn == NULLCOMMITLSN)
2995 return 0;
2996
2997try_again:
2998 spin_lock(&log->l_icloglock);
2999 iclog = log->l_iclog;
3000 if (iclog->ic_state & XLOG_STATE_IOERROR) {
3001 spin_unlock(&log->l_icloglock);
3002 return XFS_ERROR(EIO);
3003 }
3004
3005 do {
3006 if (be64_to_cpu(iclog->ic_header.h_lsn) != lsn) {
3007 iclog = iclog->ic_next;
3008 continue;
3009 }
3010
3011 if (iclog->ic_state == XLOG_STATE_DIRTY) {
3012 spin_unlock(&log->l_icloglock);
3013 return 0;
3014 }
3015
3016 if (iclog->ic_state == XLOG_STATE_ACTIVE) {
3017 /*
3018 * We sleep here if we haven't already slept (e.g.
3019 * this is the first time we've looked at the correct
3020 * iclog buf) and the buffer before us is going to
3021 * be sync'ed. The reason for this is that if we
3022 * are doing sync transactions here, by waiting for
3023 * the previous I/O to complete, we can allow a few
3024 * more transactions into this iclog before we close
3025 * it down.
3026 *
3027 * Otherwise, we mark the buffer WANT_SYNC, and bump
3028 * up the refcnt so we can release the log (which
3029 * drops the ref count). The state switch keeps new
3030 * transaction commits from using this buffer. When
3031 * the current commits finish writing into the buffer,
3032 * the refcount will drop to zero and the buffer will
3033 * go out then.
3034 */
3035 if (!already_slept &&
3036 (iclog->ic_prev->ic_state &
3037 (XLOG_STATE_WANT_SYNC | XLOG_STATE_SYNCING))) {
3038 ASSERT(!(iclog->ic_state & XLOG_STATE_IOERROR));
3039
3040 XFS_STATS_INC(xs_log_force_sleep);
3041
3042 xlog_wait(&iclog->ic_prev->ic_write_wait,
3043 &log->l_icloglock);
3044 if (log_flushed)
3045 *log_flushed = 1;
3046 already_slept = 1;
3047 goto try_again;
3048 }
3049 atomic_inc(&iclog->ic_refcnt);
3050 xlog_state_switch_iclogs(log, iclog, 0);
3051 spin_unlock(&log->l_icloglock);
3052 if (xlog_state_release_iclog(log, iclog))
3053 return XFS_ERROR(EIO);
3054 if (log_flushed)
3055 *log_flushed = 1;
3056 spin_lock(&log->l_icloglock);
3057 }
3058
3059 if ((flags & XFS_LOG_SYNC) && /* sleep */
3060 !(iclog->ic_state &
3061 (XLOG_STATE_ACTIVE | XLOG_STATE_DIRTY))) {
3062 /*
3063 * Don't wait on completion if we know that we've
3064 * gotten a log write error.
3065 */
3066 if (iclog->ic_state & XLOG_STATE_IOERROR) {
3067 spin_unlock(&log->l_icloglock);
3068 return XFS_ERROR(EIO);
3069 }
3070 XFS_STATS_INC(xs_log_force_sleep);
3071 xlog_wait(&iclog->ic_force_wait, &log->l_icloglock);
3072 /*
3073 * No need to grab the log lock here since we're
3074 * only deciding whether or not to return EIO
3075 * and the memory read should be atomic.
3076 */
3077 if (iclog->ic_state & XLOG_STATE_IOERROR)
3078 return XFS_ERROR(EIO);
3079
3080 if (log_flushed)
3081 *log_flushed = 1;
3082 } else { /* just return */
3083 spin_unlock(&log->l_icloglock);
3084 }
3085
3086 return 0;
3087 } while (iclog != log->l_iclog);
3088
3089 spin_unlock(&log->l_icloglock);
3090 return 0;
3091}
3092
3093/*
3094 * Wrapper for _xfs_log_force_lsn(), to be used when caller doesn't care
3095 * about errors or whether the log was flushed or not. This is the normal
3096 * interface to use when trying to unpin items or move the log forward.
3097 */
3098void
3099xfs_log_force_lsn(
3100 xfs_mount_t *mp,
3101 xfs_lsn_t lsn,
3102 uint flags)
3103{
3104 int error;
3105
3106 trace_xfs_log_force(mp, lsn);
3107 error = _xfs_log_force_lsn(mp, lsn, flags, NULL);
3108 if (error)
3109 xfs_warn(mp, "%s: error %d returned.", __func__, error);
3110}
3111
3112/*
3113 * Called when we want to mark the current iclog as being ready to sync to
3114 * disk.
3115 */
3116STATIC void
3117xlog_state_want_sync(xlog_t *log, xlog_in_core_t *iclog)
3118{
3119 assert_spin_locked(&log->l_icloglock);
3120
3121 if (iclog->ic_state == XLOG_STATE_ACTIVE) {
3122 xlog_state_switch_iclogs(log, iclog, 0);
3123 } else {
3124 ASSERT(iclog->ic_state &
3125 (XLOG_STATE_WANT_SYNC|XLOG_STATE_IOERROR));
3126 }
3127}
3128
3129
3130/*****************************************************************************
3131 *
3132 * TICKET functions
3133 *
3134 *****************************************************************************
3135 */
3136
3137/*
3138 * Free a used ticket when its refcount falls to zero.
3139 */
3140void
3141xfs_log_ticket_put(
3142 xlog_ticket_t *ticket)
3143{
3144 ASSERT(atomic_read(&ticket->t_ref) > 0);
3145 if (atomic_dec_and_test(&ticket->t_ref))
3146 kmem_zone_free(xfs_log_ticket_zone, ticket);
3147}
3148
3149xlog_ticket_t *
3150xfs_log_ticket_get(
3151 xlog_ticket_t *ticket)
3152{
3153 ASSERT(atomic_read(&ticket->t_ref) > 0);
3154 atomic_inc(&ticket->t_ref);
3155 return ticket;
3156}
3157
3158/*
3159 * Allocate and initialise a new log ticket.
3160 */
3161xlog_ticket_t *
3162xlog_ticket_alloc(
3163 struct xlog *log,
3164 int unit_bytes,
3165 int cnt,
3166 char client,
3167 bool permanent,
3168 xfs_km_flags_t alloc_flags)
3169{
3170 struct xlog_ticket *tic;
3171 uint num_headers;
3172 int iclog_space;
3173
3174 tic = kmem_zone_zalloc(xfs_log_ticket_zone, alloc_flags);
3175 if (!tic)
3176 return NULL;
3177
3178 /*
3179 * Permanent reservations have up to 'cnt'-1 active log operations
3180 * in the log. A unit in this case is the amount of space for one
3181 * of these log operations. Normal reservations have a cnt of 1
3182 * and their unit amount is the total amount of space required.
3183 *
3184 * The following lines of code account for non-transaction data
3185 * which occupy space in the on-disk log.
3186 *
3187 * Normal form of a transaction is:
3188 * <oph><trans-hdr><start-oph><reg1-oph><reg1><reg2-oph>...<commit-oph>
3189 * and then there are LR hdrs, split-recs and roundoff at end of syncs.
3190 *
3191 * We need to account for all the leadup data and trailer data
3192 * around the transaction data.
3193 * And then we need to account for the worst case in terms of using
3194 * more space.
3195 * The worst case will happen if:
3196 * - the placement of the transaction happens to be such that the
3197 * roundoff is at its maximum
3198 * - the transaction data is synced before the commit record is synced
3199 * i.e. <transaction-data><roundoff> | <commit-rec><roundoff>
3200 * Therefore the commit record is in its own Log Record.
3201 * This can happen as the commit record is called with its
3202 * own region to xlog_write().
3203 * This then means that in the worst case, roundoff can happen for
3204 * the commit-rec as well.
3205 * The commit-rec is smaller than padding in this scenario and so it is
3206 * not added separately.
3207 */
3208
3209 /* for trans header */
3210 unit_bytes += sizeof(xlog_op_header_t);
3211 unit_bytes += sizeof(xfs_trans_header_t);
3212
3213 /* for start-rec */
3214 unit_bytes += sizeof(xlog_op_header_t);
3215
3216 /*
3217 * for LR headers - the space for data in an iclog is the size minus
3218 * the space used for the headers. If we use the iclog size, then we
3219 * undercalculate the number of headers required.
3220 *
3221 * Furthermore - the addition of op headers for split-recs might
3222 * increase the space required enough to require more log and op
3223 * headers, so take that into account too.
3224 *
3225 * IMPORTANT: This reservation makes the assumption that if this
3226 * transaction is the first in an iclog and hence has the LR headers
3227 * accounted to it, then the remaining space in the iclog is
3228 * exclusively for this transaction. i.e. if the transaction is larger
3229 * than the iclog, it will be the only thing in that iclog.
3230 * Fundamentally, this means we must pass the entire log vector to
3231 * xlog_write to guarantee this.
3232 */
3233 iclog_space = log->l_iclog_size - log->l_iclog_hsize;
3234 num_headers = howmany(unit_bytes, iclog_space);
3235
3236 /* for split-recs - ophdrs added when data split over LRs */
3237 unit_bytes += sizeof(xlog_op_header_t) * num_headers;
3238
3239 /* add extra header reservations if we overrun */
3240 while (!num_headers ||
3241 howmany(unit_bytes, iclog_space) > num_headers) {
3242 unit_bytes += sizeof(xlog_op_header_t);
3243 num_headers++;
3244 }
3245 unit_bytes += log->l_iclog_hsize * num_headers;
3246
3247 /* for commit-rec LR header - note: padding will subsume the ophdr */
3248 unit_bytes += log->l_iclog_hsize;
3249
3250 /* for roundoff padding for transaction data and one for commit record */
3251 if (xfs_sb_version_haslogv2(&log->l_mp->m_sb) &&
3252 log->l_mp->m_sb.sb_logsunit > 1) {
3253 /* log su roundoff */
3254 unit_bytes += 2*log->l_mp->m_sb.sb_logsunit;
3255 } else {
3256 /* BB roundoff */
3257 unit_bytes += 2*BBSIZE;
3258 }
3259
3260 atomic_set(&tic->t_ref, 1);
3261 tic->t_task = current;
3262 INIT_LIST_HEAD(&tic->t_queue);
3263 tic->t_unit_res = unit_bytes;
3264 tic->t_curr_res = unit_bytes;
3265 tic->t_cnt = cnt;
3266 tic->t_ocnt = cnt;
3267 tic->t_tid = random32();
3268 tic->t_clientid = client;
3269 tic->t_flags = XLOG_TIC_INITED;
3270 tic->t_trans_type = 0;
3271 if (permanent)
3272 tic->t_flags |= XLOG_TIC_PERM_RESERV;
3273
3274 xlog_tic_reset_res(tic);
3275
3276 return tic;
3277}
3278
3279
3280/******************************************************************************
3281 *
3282 * Log debug routines
3283 *
3284 ******************************************************************************
3285 */
3286#if defined(DEBUG)
3287/*
3288 * Make sure that the destination ptr is within the valid data region of
3289 * one of the iclogs. This uses backup pointers stored in a different
3290 * part of the log in case we trash the log structure.
3291 */
3292void
3293xlog_verify_dest_ptr(
3294 struct xlog *log,
3295 char *ptr)
3296{
3297 int i;
3298 int good_ptr = 0;
3299
3300 for (i = 0; i < log->l_iclog_bufs; i++) {
3301 if (ptr >= log->l_iclog_bak[i] &&
3302 ptr <= log->l_iclog_bak[i] + log->l_iclog_size)
3303 good_ptr++;
3304 }
3305
3306 if (!good_ptr)
3307 xfs_emerg(log->l_mp, "%s: invalid ptr", __func__);
3308}
3309
3310/*
3311 * Check to make sure the grant write head didn't just over lap the tail. If
3312 * the cycles are the same, we can't be overlapping. Otherwise, make sure that
3313 * the cycles differ by exactly one and check the byte count.
3314 *
3315 * This check is run unlocked, so can give false positives. Rather than assert
3316 * on failures, use a warn-once flag and a panic tag to allow the admin to
3317 * determine if they want to panic the machine when such an error occurs. For
3318 * debug kernels this will have the same effect as using an assert but, unlinke
3319 * an assert, it can be turned off at runtime.
3320 */
3321STATIC void
3322xlog_verify_grant_tail(
3323 struct xlog *log)
3324{
3325 int tail_cycle, tail_blocks;
3326 int cycle, space;
3327
3328 xlog_crack_grant_head(&log->l_write_head.grant, &cycle, &space);
3329 xlog_crack_atomic_lsn(&log->l_tail_lsn, &tail_cycle, &tail_blocks);
3330 if (tail_cycle != cycle) {
3331 if (cycle - 1 != tail_cycle &&
3332 !(log->l_flags & XLOG_TAIL_WARN)) {
3333 xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES,
3334 "%s: cycle - 1 != tail_cycle", __func__);
3335 log->l_flags |= XLOG_TAIL_WARN;
3336 }
3337
3338 if (space > BBTOB(tail_blocks) &&
3339 !(log->l_flags & XLOG_TAIL_WARN)) {
3340 xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES,
3341 "%s: space > BBTOB(tail_blocks)", __func__);
3342 log->l_flags |= XLOG_TAIL_WARN;
3343 }
3344 }
3345}
3346
3347/* check if it will fit */
3348STATIC void
3349xlog_verify_tail_lsn(xlog_t *log,
3350 xlog_in_core_t *iclog,
3351 xfs_lsn_t tail_lsn)
3352{
3353 int blocks;
3354
3355 if (CYCLE_LSN(tail_lsn) == log->l_prev_cycle) {
3356 blocks =
3357 log->l_logBBsize - (log->l_prev_block - BLOCK_LSN(tail_lsn));
3358 if (blocks < BTOBB(iclog->ic_offset)+BTOBB(log->l_iclog_hsize))
3359 xfs_emerg(log->l_mp, "%s: ran out of log space", __func__);
3360 } else {
3361 ASSERT(CYCLE_LSN(tail_lsn)+1 == log->l_prev_cycle);
3362
3363 if (BLOCK_LSN(tail_lsn) == log->l_prev_block)
3364 xfs_emerg(log->l_mp, "%s: tail wrapped", __func__);
3365
3366 blocks = BLOCK_LSN(tail_lsn) - log->l_prev_block;
3367 if (blocks < BTOBB(iclog->ic_offset) + 1)
3368 xfs_emerg(log->l_mp, "%s: ran out of log space", __func__);
3369 }
3370} /* xlog_verify_tail_lsn */
3371
3372/*
3373 * Perform a number of checks on the iclog before writing to disk.
3374 *
3375 * 1. Make sure the iclogs are still circular
3376 * 2. Make sure we have a good magic number
3377 * 3. Make sure we don't have magic numbers in the data
3378 * 4. Check fields of each log operation header for:
3379 * A. Valid client identifier
3380 * B. tid ptr value falls in valid ptr space (user space code)
3381 * C. Length in log record header is correct according to the
3382 * individual operation headers within record.
3383 * 5. When a bwrite will occur within 5 blocks of the front of the physical
3384 * log, check the preceding blocks of the physical log to make sure all
3385 * the cycle numbers agree with the current cycle number.
3386 */
3387STATIC void
3388xlog_verify_iclog(xlog_t *log,
3389 xlog_in_core_t *iclog,
3390 int count,
3391 boolean_t syncing)
3392{
3393 xlog_op_header_t *ophead;
3394 xlog_in_core_t *icptr;
3395 xlog_in_core_2_t *xhdr;
3396 xfs_caddr_t ptr;
3397 xfs_caddr_t base_ptr;
3398 __psint_t field_offset;
3399 __uint8_t clientid;
3400 int len, i, j, k, op_len;
3401 int idx;
3402
3403 /* check validity of iclog pointers */
3404 spin_lock(&log->l_icloglock);
3405 icptr = log->l_iclog;
3406 for (i=0; i < log->l_iclog_bufs; i++) {
3407 if (icptr == NULL)
3408 xfs_emerg(log->l_mp, "%s: invalid ptr", __func__);
3409 icptr = icptr->ic_next;
3410 }
3411 if (icptr != log->l_iclog)
3412 xfs_emerg(log->l_mp, "%s: corrupt iclog ring", __func__);
3413 spin_unlock(&log->l_icloglock);
3414
3415 /* check log magic numbers */
3416 if (iclog->ic_header.h_magicno != cpu_to_be32(XLOG_HEADER_MAGIC_NUM))
3417 xfs_emerg(log->l_mp, "%s: invalid magic num", __func__);
3418
3419 ptr = (xfs_caddr_t) &iclog->ic_header;
3420 for (ptr += BBSIZE; ptr < ((xfs_caddr_t)&iclog->ic_header) + count;
3421 ptr += BBSIZE) {
3422 if (*(__be32 *)ptr == cpu_to_be32(XLOG_HEADER_MAGIC_NUM))
3423 xfs_emerg(log->l_mp, "%s: unexpected magic num",
3424 __func__);
3425 }
3426
3427 /* check fields */
3428 len = be32_to_cpu(iclog->ic_header.h_num_logops);
3429 ptr = iclog->ic_datap;
3430 base_ptr = ptr;
3431 ophead = (xlog_op_header_t *)ptr;
3432 xhdr = iclog->ic_data;
3433 for (i = 0; i < len; i++) {
3434 ophead = (xlog_op_header_t *)ptr;
3435
3436 /* clientid is only 1 byte */
3437 field_offset = (__psint_t)
3438 ((xfs_caddr_t)&(ophead->oh_clientid) - base_ptr);
3439 if (syncing == B_FALSE || (field_offset & 0x1ff)) {
3440 clientid = ophead->oh_clientid;
3441 } else {
3442 idx = BTOBBT((xfs_caddr_t)&(ophead->oh_clientid) - iclog->ic_datap);
3443 if (idx >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE)) {
3444 j = idx / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3445 k = idx % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3446 clientid = xlog_get_client_id(
3447 xhdr[j].hic_xheader.xh_cycle_data[k]);
3448 } else {
3449 clientid = xlog_get_client_id(
3450 iclog->ic_header.h_cycle_data[idx]);
3451 }
3452 }
3453 if (clientid != XFS_TRANSACTION && clientid != XFS_LOG)
3454 xfs_warn(log->l_mp,
3455 "%s: invalid clientid %d op 0x%p offset 0x%lx",
3456 __func__, clientid, ophead,
3457 (unsigned long)field_offset);
3458
3459 /* check length */
3460 field_offset = (__psint_t)
3461 ((xfs_caddr_t)&(ophead->oh_len) - base_ptr);
3462 if (syncing == B_FALSE || (field_offset & 0x1ff)) {
3463 op_len = be32_to_cpu(ophead->oh_len);
3464 } else {
3465 idx = BTOBBT((__psint_t)&ophead->oh_len -
3466 (__psint_t)iclog->ic_datap);
3467 if (idx >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE)) {
3468 j = idx / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3469 k = idx % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3470 op_len = be32_to_cpu(xhdr[j].hic_xheader.xh_cycle_data[k]);
3471 } else {
3472 op_len = be32_to_cpu(iclog->ic_header.h_cycle_data[idx]);
3473 }
3474 }
3475 ptr += sizeof(xlog_op_header_t) + op_len;
3476 }
3477} /* xlog_verify_iclog */
3478#endif
3479
3480/*
3481 * Mark all iclogs IOERROR. l_icloglock is held by the caller.
3482 */
3483STATIC int
3484xlog_state_ioerror(
3485 xlog_t *log)
3486{
3487 xlog_in_core_t *iclog, *ic;
3488
3489 iclog = log->l_iclog;
3490 if (! (iclog->ic_state & XLOG_STATE_IOERROR)) {
3491 /*
3492 * Mark all the incore logs IOERROR.
3493 * From now on, no log flushes will result.
3494 */
3495 ic = iclog;
3496 do {
3497 ic->ic_state = XLOG_STATE_IOERROR;
3498 ic = ic->ic_next;
3499 } while (ic != iclog);
3500 return 0;
3501 }
3502 /*
3503 * Return non-zero, if state transition has already happened.
3504 */
3505 return 1;
3506}
3507
3508/*
3509 * This is called from xfs_force_shutdown, when we're forcibly
3510 * shutting down the filesystem, typically because of an IO error.
3511 * Our main objectives here are to make sure that:
3512 * a. the filesystem gets marked 'SHUTDOWN' for all interested
3513 * parties to find out, 'atomically'.
3514 * b. those who're sleeping on log reservations, pinned objects and
3515 * other resources get woken up, and be told the bad news.
3516 * c. nothing new gets queued up after (a) and (b) are done.
3517 * d. if !logerror, flush the iclogs to disk, then seal them off
3518 * for business.
3519 *
3520 * Note: for delayed logging the !logerror case needs to flush the regions
3521 * held in memory out to the iclogs before flushing them to disk. This needs
3522 * to be done before the log is marked as shutdown, otherwise the flush to the
3523 * iclogs will fail.
3524 */
3525int
3526xfs_log_force_umount(
3527 struct xfs_mount *mp,
3528 int logerror)
3529{
3530 xlog_t *log;
3531 int retval;
3532
3533 log = mp->m_log;
3534
3535 /*
3536 * If this happens during log recovery, don't worry about
3537 * locking; the log isn't open for business yet.
3538 */
3539 if (!log ||
3540 log->l_flags & XLOG_ACTIVE_RECOVERY) {
3541 mp->m_flags |= XFS_MOUNT_FS_SHUTDOWN;
3542 if (mp->m_sb_bp)
3543 XFS_BUF_DONE(mp->m_sb_bp);
3544 return 0;
3545 }
3546
3547 /*
3548 * Somebody could've already done the hard work for us.
3549 * No need to get locks for this.
3550 */
3551 if (logerror && log->l_iclog->ic_state & XLOG_STATE_IOERROR) {
3552 ASSERT(XLOG_FORCED_SHUTDOWN(log));
3553 return 1;
3554 }
3555 retval = 0;
3556
3557 /*
3558 * Flush the in memory commit item list before marking the log as
3559 * being shut down. We need to do it in this order to ensure all the
3560 * completed transactions are flushed to disk with the xfs_log_force()
3561 * call below.
3562 */
3563 if (!logerror)
3564 xlog_cil_force(log);
3565
3566 /*
3567 * mark the filesystem and the as in a shutdown state and wake
3568 * everybody up to tell them the bad news.
3569 */
3570 spin_lock(&log->l_icloglock);
3571 mp->m_flags |= XFS_MOUNT_FS_SHUTDOWN;
3572 if (mp->m_sb_bp)
3573 XFS_BUF_DONE(mp->m_sb_bp);
3574
3575 /*
3576 * This flag is sort of redundant because of the mount flag, but
3577 * it's good to maintain the separation between the log and the rest
3578 * of XFS.
3579 */
3580 log->l_flags |= XLOG_IO_ERROR;
3581
3582 /*
3583 * If we hit a log error, we want to mark all the iclogs IOERROR
3584 * while we're still holding the loglock.
3585 */
3586 if (logerror)
3587 retval = xlog_state_ioerror(log);
3588 spin_unlock(&log->l_icloglock);
3589
3590 /*
3591 * We don't want anybody waiting for log reservations after this. That
3592 * means we have to wake up everybody queued up on reserveq as well as
3593 * writeq. In addition, we make sure in xlog_{re}grant_log_space that
3594 * we don't enqueue anything once the SHUTDOWN flag is set, and this
3595 * action is protected by the grant locks.
3596 */
3597 xlog_grant_head_wake_all(&log->l_reserve_head);
3598 xlog_grant_head_wake_all(&log->l_write_head);
3599
3600 if (!(log->l_iclog->ic_state & XLOG_STATE_IOERROR)) {
3601 ASSERT(!logerror);
3602 /*
3603 * Force the incore logs to disk before shutting the
3604 * log down completely.
3605 */
3606 _xfs_log_force(mp, XFS_LOG_SYNC, NULL);
3607
3608 spin_lock(&log->l_icloglock);
3609 retval = xlog_state_ioerror(log);
3610 spin_unlock(&log->l_icloglock);
3611 }
3612 /*
3613 * Wake up everybody waiting on xfs_log_force.
3614 * Callback all log item committed functions as if the
3615 * log writes were completed.
3616 */
3617 xlog_state_do_callback(log, XFS_LI_ABORTED, NULL);
3618
3619#ifdef XFSERRORDEBUG
3620 {
3621 xlog_in_core_t *iclog;
3622
3623 spin_lock(&log->l_icloglock);
3624 iclog = log->l_iclog;
3625 do {
3626 ASSERT(iclog->ic_callback == 0);
3627 iclog = iclog->ic_next;
3628 } while (iclog != log->l_iclog);
3629 spin_unlock(&log->l_icloglock);
3630 }
3631#endif
3632 /* return non-zero if log IOERROR transition had already happened */
3633 return retval;
3634}
3635
3636STATIC int
3637xlog_iclogs_empty(xlog_t *log)
3638{
3639 xlog_in_core_t *iclog;
3640
3641 iclog = log->l_iclog;
3642 do {
3643 /* endianness does not matter here, zero is zero in
3644 * any language.
3645 */
3646 if (iclog->ic_header.h_num_logops)
3647 return 0;
3648 iclog = iclog->ic_next;
3649 } while (iclog != log->l_iclog);
3650 return 1;
3651}
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
24kmem_zone_t *xfs_log_ticket_zone;
25
26/* Local miscellaneous function prototypes */
27STATIC int
28xlog_commit_record(
29 struct xlog *log,
30 struct xlog_ticket *ticket,
31 struct xlog_in_core **iclog,
32 xfs_lsn_t *commitlsnp);
33
34STATIC struct xlog *
35xlog_alloc_log(
36 struct xfs_mount *mp,
37 struct xfs_buftarg *log_target,
38 xfs_daddr_t blk_offset,
39 int num_bblks);
40STATIC int
41xlog_space_left(
42 struct xlog *log,
43 atomic64_t *head);
44STATIC void
45xlog_dealloc_log(
46 struct xlog *log);
47
48/* local state machine functions */
49STATIC void xlog_state_done_syncing(
50 struct xlog_in_core *iclog,
51 bool aborted);
52STATIC int
53xlog_state_get_iclog_space(
54 struct xlog *log,
55 int len,
56 struct xlog_in_core **iclog,
57 struct xlog_ticket *ticket,
58 int *continued_write,
59 int *logoffsetp);
60STATIC int
61xlog_state_release_iclog(
62 struct xlog *log,
63 struct xlog_in_core *iclog);
64STATIC void
65xlog_state_switch_iclogs(
66 struct xlog *log,
67 struct xlog_in_core *iclog,
68 int eventual_size);
69STATIC void
70xlog_state_want_sync(
71 struct xlog *log,
72 struct xlog_in_core *iclog);
73
74STATIC void
75xlog_grant_push_ail(
76 struct xlog *log,
77 int need_bytes);
78STATIC void
79xlog_regrant_reserve_log_space(
80 struct xlog *log,
81 struct xlog_ticket *ticket);
82STATIC void
83xlog_ungrant_log_space(
84 struct xlog *log,
85 struct xlog_ticket *ticket);
86
87#if defined(DEBUG)
88STATIC void
89xlog_verify_dest_ptr(
90 struct xlog *log,
91 void *ptr);
92STATIC void
93xlog_verify_grant_tail(
94 struct xlog *log);
95STATIC void
96xlog_verify_iclog(
97 struct xlog *log,
98 struct xlog_in_core *iclog,
99 int count);
100STATIC void
101xlog_verify_tail_lsn(
102 struct xlog *log,
103 struct xlog_in_core *iclog,
104 xfs_lsn_t tail_lsn);
105#else
106#define xlog_verify_dest_ptr(a,b)
107#define xlog_verify_grant_tail(a)
108#define xlog_verify_iclog(a,b,c)
109#define xlog_verify_tail_lsn(a,b,c)
110#endif
111
112STATIC int
113xlog_iclogs_empty(
114 struct xlog *log);
115
116static void
117xlog_grant_sub_space(
118 struct xlog *log,
119 atomic64_t *head,
120 int bytes)
121{
122 int64_t head_val = atomic64_read(head);
123 int64_t new, old;
124
125 do {
126 int cycle, space;
127
128 xlog_crack_grant_head_val(head_val, &cycle, &space);
129
130 space -= bytes;
131 if (space < 0) {
132 space += log->l_logsize;
133 cycle--;
134 }
135
136 old = head_val;
137 new = xlog_assign_grant_head_val(cycle, space);
138 head_val = atomic64_cmpxchg(head, old, new);
139 } while (head_val != old);
140}
141
142static void
143xlog_grant_add_space(
144 struct xlog *log,
145 atomic64_t *head,
146 int bytes)
147{
148 int64_t head_val = atomic64_read(head);
149 int64_t new, old;
150
151 do {
152 int tmp;
153 int cycle, space;
154
155 xlog_crack_grant_head_val(head_val, &cycle, &space);
156
157 tmp = log->l_logsize - space;
158 if (tmp > bytes)
159 space += bytes;
160 else {
161 space = bytes - tmp;
162 cycle++;
163 }
164
165 old = head_val;
166 new = xlog_assign_grant_head_val(cycle, space);
167 head_val = atomic64_cmpxchg(head, old, new);
168 } while (head_val != old);
169}
170
171STATIC void
172xlog_grant_head_init(
173 struct xlog_grant_head *head)
174{
175 xlog_assign_grant_head(&head->grant, 1, 0);
176 INIT_LIST_HEAD(&head->waiters);
177 spin_lock_init(&head->lock);
178}
179
180STATIC void
181xlog_grant_head_wake_all(
182 struct xlog_grant_head *head)
183{
184 struct xlog_ticket *tic;
185
186 spin_lock(&head->lock);
187 list_for_each_entry(tic, &head->waiters, t_queue)
188 wake_up_process(tic->t_task);
189 spin_unlock(&head->lock);
190}
191
192static inline int
193xlog_ticket_reservation(
194 struct xlog *log,
195 struct xlog_grant_head *head,
196 struct xlog_ticket *tic)
197{
198 if (head == &log->l_write_head) {
199 ASSERT(tic->t_flags & XLOG_TIC_PERM_RESERV);
200 return tic->t_unit_res;
201 } else {
202 if (tic->t_flags & XLOG_TIC_PERM_RESERV)
203 return tic->t_unit_res * tic->t_cnt;
204 else
205 return tic->t_unit_res;
206 }
207}
208
209STATIC bool
210xlog_grant_head_wake(
211 struct xlog *log,
212 struct xlog_grant_head *head,
213 int *free_bytes)
214{
215 struct xlog_ticket *tic;
216 int need_bytes;
217 bool woken_task = false;
218
219 list_for_each_entry(tic, &head->waiters, t_queue) {
220
221 /*
222 * There is a chance that the size of the CIL checkpoints in
223 * progress at the last AIL push target calculation resulted in
224 * limiting the target to the log head (l_last_sync_lsn) at the
225 * time. This may not reflect where the log head is now as the
226 * CIL checkpoints may have completed.
227 *
228 * Hence when we are woken here, it may be that the head of the
229 * log that has moved rather than the tail. As the tail didn't
230 * move, there still won't be space available for the
231 * reservation we require. However, if the AIL has already
232 * pushed to the target defined by the old log head location, we
233 * will hang here waiting for something else to update the AIL
234 * push target.
235 *
236 * Therefore, if there isn't space to wake the first waiter on
237 * the grant head, we need to push the AIL again to ensure the
238 * target reflects both the current log tail and log head
239 * position before we wait for the tail to move again.
240 */
241
242 need_bytes = xlog_ticket_reservation(log, head, tic);
243 if (*free_bytes < need_bytes) {
244 if (!woken_task)
245 xlog_grant_push_ail(log, need_bytes);
246 return false;
247 }
248
249 *free_bytes -= need_bytes;
250 trace_xfs_log_grant_wake_up(log, tic);
251 wake_up_process(tic->t_task);
252 woken_task = true;
253 }
254
255 return true;
256}
257
258STATIC int
259xlog_grant_head_wait(
260 struct xlog *log,
261 struct xlog_grant_head *head,
262 struct xlog_ticket *tic,
263 int need_bytes) __releases(&head->lock)
264 __acquires(&head->lock)
265{
266 list_add_tail(&tic->t_queue, &head->waiters);
267
268 do {
269 if (XLOG_FORCED_SHUTDOWN(log))
270 goto shutdown;
271 xlog_grant_push_ail(log, need_bytes);
272
273 __set_current_state(TASK_UNINTERRUPTIBLE);
274 spin_unlock(&head->lock);
275
276 XFS_STATS_INC(log->l_mp, xs_sleep_logspace);
277
278 trace_xfs_log_grant_sleep(log, tic);
279 schedule();
280 trace_xfs_log_grant_wake(log, tic);
281
282 spin_lock(&head->lock);
283 if (XLOG_FORCED_SHUTDOWN(log))
284 goto shutdown;
285 } while (xlog_space_left(log, &head->grant) < need_bytes);
286
287 list_del_init(&tic->t_queue);
288 return 0;
289shutdown:
290 list_del_init(&tic->t_queue);
291 return -EIO;
292}
293
294/*
295 * Atomically get the log space required for a log ticket.
296 *
297 * Once a ticket gets put onto head->waiters, it will only return after the
298 * needed reservation is satisfied.
299 *
300 * This function is structured so that it has a lock free fast path. This is
301 * necessary because every new transaction reservation will come through this
302 * path. Hence any lock will be globally hot if we take it unconditionally on
303 * every pass.
304 *
305 * As tickets are only ever moved on and off head->waiters under head->lock, we
306 * only need to take that lock if we are going to add the ticket to the queue
307 * and sleep. We can avoid taking the lock if the ticket was never added to
308 * head->waiters because the t_queue list head will be empty and we hold the
309 * only reference to it so it can safely be checked unlocked.
310 */
311STATIC int
312xlog_grant_head_check(
313 struct xlog *log,
314 struct xlog_grant_head *head,
315 struct xlog_ticket *tic,
316 int *need_bytes)
317{
318 int free_bytes;
319 int error = 0;
320
321 ASSERT(!(log->l_flags & XLOG_ACTIVE_RECOVERY));
322
323 /*
324 * If there are other waiters on the queue then give them a chance at
325 * logspace before us. Wake up the first waiters, if we do not wake
326 * up all the waiters then go to sleep waiting for more free space,
327 * otherwise try to get some space for this transaction.
328 */
329 *need_bytes = xlog_ticket_reservation(log, head, tic);
330 free_bytes = xlog_space_left(log, &head->grant);
331 if (!list_empty_careful(&head->waiters)) {
332 spin_lock(&head->lock);
333 if (!xlog_grant_head_wake(log, head, &free_bytes) ||
334 free_bytes < *need_bytes) {
335 error = xlog_grant_head_wait(log, head, tic,
336 *need_bytes);
337 }
338 spin_unlock(&head->lock);
339 } else if (free_bytes < *need_bytes) {
340 spin_lock(&head->lock);
341 error = xlog_grant_head_wait(log, head, tic, *need_bytes);
342 spin_unlock(&head->lock);
343 }
344
345 return error;
346}
347
348static void
349xlog_tic_reset_res(xlog_ticket_t *tic)
350{
351 tic->t_res_num = 0;
352 tic->t_res_arr_sum = 0;
353 tic->t_res_num_ophdrs = 0;
354}
355
356static void
357xlog_tic_add_region(xlog_ticket_t *tic, uint len, uint type)
358{
359 if (tic->t_res_num == XLOG_TIC_LEN_MAX) {
360 /* add to overflow and start again */
361 tic->t_res_o_flow += tic->t_res_arr_sum;
362 tic->t_res_num = 0;
363 tic->t_res_arr_sum = 0;
364 }
365
366 tic->t_res_arr[tic->t_res_num].r_len = len;
367 tic->t_res_arr[tic->t_res_num].r_type = type;
368 tic->t_res_arr_sum += len;
369 tic->t_res_num++;
370}
371
372/*
373 * Replenish the byte reservation required by moving the grant write head.
374 */
375int
376xfs_log_regrant(
377 struct xfs_mount *mp,
378 struct xlog_ticket *tic)
379{
380 struct xlog *log = mp->m_log;
381 int need_bytes;
382 int error = 0;
383
384 if (XLOG_FORCED_SHUTDOWN(log))
385 return -EIO;
386
387 XFS_STATS_INC(mp, xs_try_logspace);
388
389 /*
390 * This is a new transaction on the ticket, so we need to change the
391 * transaction ID so that the next transaction has a different TID in
392 * the log. Just add one to the existing tid so that we can see chains
393 * of rolling transactions in the log easily.
394 */
395 tic->t_tid++;
396
397 xlog_grant_push_ail(log, tic->t_unit_res);
398
399 tic->t_curr_res = tic->t_unit_res;
400 xlog_tic_reset_res(tic);
401
402 if (tic->t_cnt > 0)
403 return 0;
404
405 trace_xfs_log_regrant(log, tic);
406
407 error = xlog_grant_head_check(log, &log->l_write_head, tic,
408 &need_bytes);
409 if (error)
410 goto out_error;
411
412 xlog_grant_add_space(log, &log->l_write_head.grant, need_bytes);
413 trace_xfs_log_regrant_exit(log, tic);
414 xlog_verify_grant_tail(log);
415 return 0;
416
417out_error:
418 /*
419 * If we are failing, make sure the ticket doesn't have any current
420 * reservations. We don't want to add this back when the ticket/
421 * transaction gets cancelled.
422 */
423 tic->t_curr_res = 0;
424 tic->t_cnt = 0; /* ungrant will give back unit_res * t_cnt. */
425 return error;
426}
427
428/*
429 * Reserve log space and return a ticket corresponding to the reservation.
430 *
431 * Each reservation is going to reserve extra space for a log record header.
432 * When writes happen to the on-disk log, we don't subtract the length of the
433 * log record header from any reservation. By wasting space in each
434 * reservation, we prevent over allocation problems.
435 */
436int
437xfs_log_reserve(
438 struct xfs_mount *mp,
439 int unit_bytes,
440 int cnt,
441 struct xlog_ticket **ticp,
442 uint8_t client,
443 bool permanent)
444{
445 struct xlog *log = mp->m_log;
446 struct xlog_ticket *tic;
447 int need_bytes;
448 int error = 0;
449
450 ASSERT(client == XFS_TRANSACTION || client == XFS_LOG);
451
452 if (XLOG_FORCED_SHUTDOWN(log))
453 return -EIO;
454
455 XFS_STATS_INC(mp, xs_try_logspace);
456
457 ASSERT(*ticp == NULL);
458 tic = xlog_ticket_alloc(log, unit_bytes, cnt, client, permanent, 0);
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
555int
556xfs_log_release_iclog(
557 struct xfs_mount *mp,
558 struct xlog_in_core *iclog)
559{
560 if (xlog_state_release_iclog(mp->m_log, iclog)) {
561 xfs_force_shutdown(mp, SHUTDOWN_LOG_IO_ERROR);
562 return -EIO;
563 }
564
565 return 0;
566}
567
568/*
569 * Mount a log filesystem
570 *
571 * mp - ubiquitous xfs mount point structure
572 * log_target - buftarg of on-disk log device
573 * blk_offset - Start block # where block size is 512 bytes (BBSIZE)
574 * num_bblocks - Number of BBSIZE blocks in on-disk log
575 *
576 * Return error or zero.
577 */
578int
579xfs_log_mount(
580 xfs_mount_t *mp,
581 xfs_buftarg_t *log_target,
582 xfs_daddr_t blk_offset,
583 int num_bblks)
584{
585 bool fatal = xfs_sb_version_hascrc(&mp->m_sb);
586 int error = 0;
587 int min_logfsbs;
588
589 if (!(mp->m_flags & XFS_MOUNT_NORECOVERY)) {
590 xfs_notice(mp, "Mounting V%d Filesystem",
591 XFS_SB_VERSION_NUM(&mp->m_sb));
592 } else {
593 xfs_notice(mp,
594"Mounting V%d filesystem in no-recovery mode. Filesystem will be inconsistent.",
595 XFS_SB_VERSION_NUM(&mp->m_sb));
596 ASSERT(mp->m_flags & XFS_MOUNT_RDONLY);
597 }
598
599 mp->m_log = xlog_alloc_log(mp, log_target, blk_offset, num_bblks);
600 if (IS_ERR(mp->m_log)) {
601 error = PTR_ERR(mp->m_log);
602 goto out;
603 }
604
605 /*
606 * Validate the given log space and drop a critical message via syslog
607 * if the log size is too small that would lead to some unexpected
608 * situations in transaction log space reservation stage.
609 *
610 * Note: we can't just reject the mount if the validation fails. This
611 * would mean that people would have to downgrade their kernel just to
612 * remedy the situation as there is no way to grow the log (short of
613 * black magic surgery with xfs_db).
614 *
615 * We can, however, reject mounts for CRC format filesystems, as the
616 * mkfs binary being used to make the filesystem should never create a
617 * filesystem with a log that is too small.
618 */
619 min_logfsbs = xfs_log_calc_minimum_size(mp);
620
621 if (mp->m_sb.sb_logblocks < min_logfsbs) {
622 xfs_warn(mp,
623 "Log size %d blocks too small, minimum size is %d blocks",
624 mp->m_sb.sb_logblocks, min_logfsbs);
625 error = -EINVAL;
626 } else if (mp->m_sb.sb_logblocks > XFS_MAX_LOG_BLOCKS) {
627 xfs_warn(mp,
628 "Log size %d blocks too large, maximum size is %lld blocks",
629 mp->m_sb.sb_logblocks, XFS_MAX_LOG_BLOCKS);
630 error = -EINVAL;
631 } else if (XFS_FSB_TO_B(mp, mp->m_sb.sb_logblocks) > XFS_MAX_LOG_BYTES) {
632 xfs_warn(mp,
633 "log size %lld bytes too large, maximum size is %lld bytes",
634 XFS_FSB_TO_B(mp, mp->m_sb.sb_logblocks),
635 XFS_MAX_LOG_BYTES);
636 error = -EINVAL;
637 } else if (mp->m_sb.sb_logsunit > 1 &&
638 mp->m_sb.sb_logsunit % mp->m_sb.sb_blocksize) {
639 xfs_warn(mp,
640 "log stripe unit %u bytes must be a multiple of block size",
641 mp->m_sb.sb_logsunit);
642 error = -EINVAL;
643 fatal = true;
644 }
645 if (error) {
646 /*
647 * Log check errors are always fatal on v5; or whenever bad
648 * metadata leads to a crash.
649 */
650 if (fatal) {
651 xfs_crit(mp, "AAIEEE! Log failed size checks. Abort!");
652 ASSERT(0);
653 goto out_free_log;
654 }
655 xfs_crit(mp, "Log size out of supported range.");
656 xfs_crit(mp,
657"Continuing onwards, but if log hangs are experienced then please report this message in the bug report.");
658 }
659
660 /*
661 * Initialize the AIL now we have a log.
662 */
663 error = xfs_trans_ail_init(mp);
664 if (error) {
665 xfs_warn(mp, "AIL initialisation failed: error %d", error);
666 goto out_free_log;
667 }
668 mp->m_log->l_ailp = mp->m_ail;
669
670 /*
671 * skip log recovery on a norecovery mount. pretend it all
672 * just worked.
673 */
674 if (!(mp->m_flags & XFS_MOUNT_NORECOVERY)) {
675 int readonly = (mp->m_flags & XFS_MOUNT_RDONLY);
676
677 if (readonly)
678 mp->m_flags &= ~XFS_MOUNT_RDONLY;
679
680 error = xlog_recover(mp->m_log);
681
682 if (readonly)
683 mp->m_flags |= XFS_MOUNT_RDONLY;
684 if (error) {
685 xfs_warn(mp, "log mount/recovery failed: error %d",
686 error);
687 xlog_recover_cancel(mp->m_log);
688 goto out_destroy_ail;
689 }
690 }
691
692 error = xfs_sysfs_init(&mp->m_log->l_kobj, &xfs_log_ktype, &mp->m_kobj,
693 "log");
694 if (error)
695 goto out_destroy_ail;
696
697 /* Normal transactions can now occur */
698 mp->m_log->l_flags &= ~XLOG_ACTIVE_RECOVERY;
699
700 /*
701 * Now the log has been fully initialised and we know were our
702 * space grant counters are, we can initialise the permanent ticket
703 * needed for delayed logging to work.
704 */
705 xlog_cil_init_post_recovery(mp->m_log);
706
707 return 0;
708
709out_destroy_ail:
710 xfs_trans_ail_destroy(mp);
711out_free_log:
712 xlog_dealloc_log(mp->m_log);
713out:
714 return error;
715}
716
717/*
718 * Finish the recovery of the file system. This is separate from the
719 * xfs_log_mount() call, because it depends on the code in xfs_mountfs() to read
720 * in the root and real-time bitmap inodes between calling xfs_log_mount() and
721 * here.
722 *
723 * If we finish recovery successfully, start the background log work. If we are
724 * not doing recovery, then we have a RO filesystem and we don't need to start
725 * it.
726 */
727int
728xfs_log_mount_finish(
729 struct xfs_mount *mp)
730{
731 int error = 0;
732 bool readonly = (mp->m_flags & XFS_MOUNT_RDONLY);
733 bool recovered = mp->m_log->l_flags & XLOG_RECOVERY_NEEDED;
734
735 if (mp->m_flags & XFS_MOUNT_NORECOVERY) {
736 ASSERT(mp->m_flags & XFS_MOUNT_RDONLY);
737 return 0;
738 } else if (readonly) {
739 /* Allow unlinked processing to proceed */
740 mp->m_flags &= ~XFS_MOUNT_RDONLY;
741 }
742
743 /*
744 * During the second phase of log recovery, we need iget and
745 * iput to behave like they do for an active filesystem.
746 * xfs_fs_drop_inode needs to be able to prevent the deletion
747 * of inodes before we're done replaying log items on those
748 * inodes. Turn it off immediately after recovery finishes
749 * so that we don't leak the quota inodes if subsequent mount
750 * activities fail.
751 *
752 * We let all inodes involved in redo item processing end up on
753 * the LRU instead of being evicted immediately so that if we do
754 * something to an unlinked inode, the irele won't cause
755 * premature truncation and freeing of the inode, which results
756 * in log recovery failure. We have to evict the unreferenced
757 * lru inodes after clearing SB_ACTIVE because we don't
758 * otherwise clean up the lru if there's a subsequent failure in
759 * xfs_mountfs, which leads to us leaking the inodes if nothing
760 * else (e.g. quotacheck) references the inodes before the
761 * mount failure occurs.
762 */
763 mp->m_super->s_flags |= SB_ACTIVE;
764 error = xlog_recover_finish(mp->m_log);
765 if (!error)
766 xfs_log_work_queue(mp);
767 mp->m_super->s_flags &= ~SB_ACTIVE;
768 evict_inodes(mp->m_super);
769
770 /*
771 * Drain the buffer LRU after log recovery. This is required for v4
772 * filesystems to avoid leaving around buffers with NULL verifier ops,
773 * but we do it unconditionally to make sure we're always in a clean
774 * cache state after mount.
775 *
776 * Don't push in the error case because the AIL may have pending intents
777 * that aren't removed until recovery is cancelled.
778 */
779 if (!error && recovered) {
780 xfs_log_force(mp, XFS_LOG_SYNC);
781 xfs_ail_push_all_sync(mp->m_ail);
782 }
783 xfs_wait_buftarg(mp->m_ddev_targp);
784
785 if (readonly)
786 mp->m_flags |= XFS_MOUNT_RDONLY;
787
788 return error;
789}
790
791/*
792 * The mount has failed. Cancel the recovery if it hasn't completed and destroy
793 * the log.
794 */
795void
796xfs_log_mount_cancel(
797 struct xfs_mount *mp)
798{
799 xlog_recover_cancel(mp->m_log);
800 xfs_log_unmount(mp);
801}
802
803/*
804 * Final log writes as part of unmount.
805 *
806 * Mark the filesystem clean as unmount happens. Note that during relocation
807 * this routine needs to be executed as part of source-bag while the
808 * deallocation must not be done until source-end.
809 */
810
811/* Actually write the unmount record to disk. */
812static void
813xfs_log_write_unmount_record(
814 struct xfs_mount *mp)
815{
816 /* the data section must be 32 bit size aligned */
817 struct xfs_unmount_log_format magic = {
818 .magic = XLOG_UNMOUNT_TYPE,
819 };
820 struct xfs_log_iovec reg = {
821 .i_addr = &magic,
822 .i_len = sizeof(magic),
823 .i_type = XLOG_REG_TYPE_UNMOUNT,
824 };
825 struct xfs_log_vec vec = {
826 .lv_niovecs = 1,
827 .lv_iovecp = ®,
828 };
829 struct xlog *log = mp->m_log;
830 struct xlog_in_core *iclog;
831 struct xlog_ticket *tic = NULL;
832 xfs_lsn_t lsn;
833 uint flags = XLOG_UNMOUNT_TRANS;
834 int error;
835
836 error = xfs_log_reserve(mp, 600, 1, &tic, XFS_LOG, 0);
837 if (error)
838 goto out_err;
839
840 /*
841 * If we think the summary counters are bad, clear the unmount header
842 * flag in the unmount record so that the summary counters will be
843 * recalculated during log recovery at next mount. Refer to
844 * xlog_check_unmount_rec for more details.
845 */
846 if (XFS_TEST_ERROR(xfs_fs_has_sickness(mp, XFS_SICK_FS_COUNTERS), mp,
847 XFS_ERRTAG_FORCE_SUMMARY_RECALC)) {
848 xfs_alert(mp, "%s: will fix summary counters at next mount",
849 __func__);
850 flags &= ~XLOG_UNMOUNT_TRANS;
851 }
852
853 /* remove inited flag, and account for space used */
854 tic->t_flags = 0;
855 tic->t_curr_res -= sizeof(magic);
856 error = xlog_write(log, &vec, tic, &lsn, NULL, flags);
857 /*
858 * At this point, we're umounting anyway, so there's no point in
859 * transitioning log state to IOERROR. Just continue...
860 */
861out_err:
862 if (error)
863 xfs_alert(mp, "%s: unmount record failed", __func__);
864
865 spin_lock(&log->l_icloglock);
866 iclog = log->l_iclog;
867 atomic_inc(&iclog->ic_refcnt);
868 xlog_state_want_sync(log, iclog);
869 spin_unlock(&log->l_icloglock);
870 error = xlog_state_release_iclog(log, iclog);
871
872 spin_lock(&log->l_icloglock);
873 switch (iclog->ic_state) {
874 default:
875 if (!XLOG_FORCED_SHUTDOWN(log)) {
876 xlog_wait(&iclog->ic_force_wait, &log->l_icloglock);
877 break;
878 }
879 /* fall through */
880 case XLOG_STATE_ACTIVE:
881 case XLOG_STATE_DIRTY:
882 spin_unlock(&log->l_icloglock);
883 break;
884 }
885
886 if (tic) {
887 trace_xfs_log_umount_write(log, tic);
888 xlog_ungrant_log_space(log, tic);
889 xfs_log_ticket_put(tic);
890 }
891}
892
893/*
894 * Unmount record used to have a string "Unmount filesystem--" in the
895 * data section where the "Un" was really a magic number (XLOG_UNMOUNT_TYPE).
896 * We just write the magic number now since that particular field isn't
897 * currently architecture converted and "Unmount" is a bit foo.
898 * As far as I know, there weren't any dependencies on the old behaviour.
899 */
900
901static int
902xfs_log_unmount_write(xfs_mount_t *mp)
903{
904 struct xlog *log = mp->m_log;
905 xlog_in_core_t *iclog;
906#ifdef DEBUG
907 xlog_in_core_t *first_iclog;
908#endif
909 int error;
910
911 /*
912 * Don't write out unmount record on norecovery mounts or ro devices.
913 * Or, if we are doing a forced umount (typically because of IO errors).
914 */
915 if (mp->m_flags & XFS_MOUNT_NORECOVERY ||
916 xfs_readonly_buftarg(log->l_targ)) {
917 ASSERT(mp->m_flags & XFS_MOUNT_RDONLY);
918 return 0;
919 }
920
921 error = xfs_log_force(mp, XFS_LOG_SYNC);
922 ASSERT(error || !(XLOG_FORCED_SHUTDOWN(log)));
923
924#ifdef DEBUG
925 first_iclog = iclog = log->l_iclog;
926 do {
927 if (!(iclog->ic_state & XLOG_STATE_IOERROR)) {
928 ASSERT(iclog->ic_state & XLOG_STATE_ACTIVE);
929 ASSERT(iclog->ic_offset == 0);
930 }
931 iclog = iclog->ic_next;
932 } while (iclog != first_iclog);
933#endif
934 if (! (XLOG_FORCED_SHUTDOWN(log))) {
935 xfs_log_write_unmount_record(mp);
936 } else {
937 /*
938 * We're already in forced_shutdown mode, couldn't
939 * even attempt to write out the unmount transaction.
940 *
941 * Go through the motions of sync'ing and releasing
942 * the iclog, even though no I/O will actually happen,
943 * we need to wait for other log I/Os that may already
944 * be in progress. Do this as a separate section of
945 * code so we'll know if we ever get stuck here that
946 * we're in this odd situation of trying to unmount
947 * a file system that went into forced_shutdown as
948 * the result of an unmount..
949 */
950 spin_lock(&log->l_icloglock);
951 iclog = log->l_iclog;
952 atomic_inc(&iclog->ic_refcnt);
953
954 xlog_state_want_sync(log, iclog);
955 spin_unlock(&log->l_icloglock);
956 error = xlog_state_release_iclog(log, iclog);
957
958 spin_lock(&log->l_icloglock);
959
960 if ( ! ( iclog->ic_state == XLOG_STATE_ACTIVE
961 || iclog->ic_state == XLOG_STATE_DIRTY
962 || iclog->ic_state == XLOG_STATE_IOERROR) ) {
963
964 xlog_wait(&iclog->ic_force_wait,
965 &log->l_icloglock);
966 } else {
967 spin_unlock(&log->l_icloglock);
968 }
969 }
970
971 return error;
972} /* xfs_log_unmount_write */
973
974/*
975 * Empty the log for unmount/freeze.
976 *
977 * To do this, we first need to shut down the background log work so it is not
978 * trying to cover the log as we clean up. We then need to unpin all objects in
979 * the log so we can then flush them out. Once they have completed their IO and
980 * run the callbacks removing themselves from the AIL, we can write the unmount
981 * record.
982 */
983void
984xfs_log_quiesce(
985 struct xfs_mount *mp)
986{
987 cancel_delayed_work_sync(&mp->m_log->l_work);
988 xfs_log_force(mp, XFS_LOG_SYNC);
989
990 /*
991 * The superblock buffer is uncached and while xfs_ail_push_all_sync()
992 * will push it, xfs_wait_buftarg() will not wait for it. Further,
993 * xfs_buf_iowait() cannot be used because it was pushed with the
994 * XBF_ASYNC flag set, so we need to use a lock/unlock pair to wait for
995 * the IO to complete.
996 */
997 xfs_ail_push_all_sync(mp->m_ail);
998 xfs_wait_buftarg(mp->m_ddev_targp);
999 xfs_buf_lock(mp->m_sb_bp);
1000 xfs_buf_unlock(mp->m_sb_bp);
1001
1002 xfs_log_unmount_write(mp);
1003}
1004
1005/*
1006 * Shut down and release the AIL and Log.
1007 *
1008 * During unmount, we need to ensure we flush all the dirty metadata objects
1009 * from the AIL so that the log is empty before we write the unmount record to
1010 * the log. Once this is done, we can tear down the AIL and the log.
1011 */
1012void
1013xfs_log_unmount(
1014 struct xfs_mount *mp)
1015{
1016 xfs_log_quiesce(mp);
1017
1018 xfs_trans_ail_destroy(mp);
1019
1020 xfs_sysfs_del(&mp->m_log->l_kobj);
1021
1022 xlog_dealloc_log(mp->m_log);
1023}
1024
1025void
1026xfs_log_item_init(
1027 struct xfs_mount *mp,
1028 struct xfs_log_item *item,
1029 int type,
1030 const struct xfs_item_ops *ops)
1031{
1032 item->li_mountp = mp;
1033 item->li_ailp = mp->m_ail;
1034 item->li_type = type;
1035 item->li_ops = ops;
1036 item->li_lv = NULL;
1037
1038 INIT_LIST_HEAD(&item->li_ail);
1039 INIT_LIST_HEAD(&item->li_cil);
1040 INIT_LIST_HEAD(&item->li_bio_list);
1041 INIT_LIST_HEAD(&item->li_trans);
1042}
1043
1044/*
1045 * Wake up processes waiting for log space after we have moved the log tail.
1046 */
1047void
1048xfs_log_space_wake(
1049 struct xfs_mount *mp)
1050{
1051 struct xlog *log = mp->m_log;
1052 int free_bytes;
1053
1054 if (XLOG_FORCED_SHUTDOWN(log))
1055 return;
1056
1057 if (!list_empty_careful(&log->l_write_head.waiters)) {
1058 ASSERT(!(log->l_flags & XLOG_ACTIVE_RECOVERY));
1059
1060 spin_lock(&log->l_write_head.lock);
1061 free_bytes = xlog_space_left(log, &log->l_write_head.grant);
1062 xlog_grant_head_wake(log, &log->l_write_head, &free_bytes);
1063 spin_unlock(&log->l_write_head.lock);
1064 }
1065
1066 if (!list_empty_careful(&log->l_reserve_head.waiters)) {
1067 ASSERT(!(log->l_flags & XLOG_ACTIVE_RECOVERY));
1068
1069 spin_lock(&log->l_reserve_head.lock);
1070 free_bytes = xlog_space_left(log, &log->l_reserve_head.grant);
1071 xlog_grant_head_wake(log, &log->l_reserve_head, &free_bytes);
1072 spin_unlock(&log->l_reserve_head.lock);
1073 }
1074}
1075
1076/*
1077 * Determine if we have a transaction that has gone to disk that needs to be
1078 * covered. To begin the transition to the idle state firstly the log needs to
1079 * be idle. That means the CIL, the AIL and the iclogs needs to be empty before
1080 * we start attempting to cover the log.
1081 *
1082 * Only if we are then in a state where covering is needed, the caller is
1083 * informed that dummy transactions are required to move the log into the idle
1084 * state.
1085 *
1086 * If there are any items in the AIl or CIL, then we do not want to attempt to
1087 * cover the log as we may be in a situation where there isn't log space
1088 * available to run a dummy transaction and this can lead to deadlocks when the
1089 * tail of the log is pinned by an item that is modified in the CIL. Hence
1090 * there's no point in running a dummy transaction at this point because we
1091 * can't start trying to idle the log until both the CIL and AIL are empty.
1092 */
1093static int
1094xfs_log_need_covered(xfs_mount_t *mp)
1095{
1096 struct xlog *log = mp->m_log;
1097 int needed = 0;
1098
1099 if (!xfs_fs_writable(mp, SB_FREEZE_WRITE))
1100 return 0;
1101
1102 if (!xlog_cil_empty(log))
1103 return 0;
1104
1105 spin_lock(&log->l_icloglock);
1106 switch (log->l_covered_state) {
1107 case XLOG_STATE_COVER_DONE:
1108 case XLOG_STATE_COVER_DONE2:
1109 case XLOG_STATE_COVER_IDLE:
1110 break;
1111 case XLOG_STATE_COVER_NEED:
1112 case XLOG_STATE_COVER_NEED2:
1113 if (xfs_ail_min_lsn(log->l_ailp))
1114 break;
1115 if (!xlog_iclogs_empty(log))
1116 break;
1117
1118 needed = 1;
1119 if (log->l_covered_state == XLOG_STATE_COVER_NEED)
1120 log->l_covered_state = XLOG_STATE_COVER_DONE;
1121 else
1122 log->l_covered_state = XLOG_STATE_COVER_DONE2;
1123 break;
1124 default:
1125 needed = 1;
1126 break;
1127 }
1128 spin_unlock(&log->l_icloglock);
1129 return needed;
1130}
1131
1132/*
1133 * We may be holding the log iclog lock upon entering this routine.
1134 */
1135xfs_lsn_t
1136xlog_assign_tail_lsn_locked(
1137 struct xfs_mount *mp)
1138{
1139 struct xlog *log = mp->m_log;
1140 struct xfs_log_item *lip;
1141 xfs_lsn_t tail_lsn;
1142
1143 assert_spin_locked(&mp->m_ail->ail_lock);
1144
1145 /*
1146 * To make sure we always have a valid LSN for the log tail we keep
1147 * track of the last LSN which was committed in log->l_last_sync_lsn,
1148 * and use that when the AIL was empty.
1149 */
1150 lip = xfs_ail_min(mp->m_ail);
1151 if (lip)
1152 tail_lsn = lip->li_lsn;
1153 else
1154 tail_lsn = atomic64_read(&log->l_last_sync_lsn);
1155 trace_xfs_log_assign_tail_lsn(log, tail_lsn);
1156 atomic64_set(&log->l_tail_lsn, tail_lsn);
1157 return tail_lsn;
1158}
1159
1160xfs_lsn_t
1161xlog_assign_tail_lsn(
1162 struct xfs_mount *mp)
1163{
1164 xfs_lsn_t tail_lsn;
1165
1166 spin_lock(&mp->m_ail->ail_lock);
1167 tail_lsn = xlog_assign_tail_lsn_locked(mp);
1168 spin_unlock(&mp->m_ail->ail_lock);
1169
1170 return tail_lsn;
1171}
1172
1173/*
1174 * Return the space in the log between the tail and the head. The head
1175 * is passed in the cycle/bytes formal parms. In the special case where
1176 * the reserve head has wrapped passed the tail, this calculation is no
1177 * longer valid. In this case, just return 0 which means there is no space
1178 * in the log. This works for all places where this function is called
1179 * with the reserve head. Of course, if the write head were to ever
1180 * wrap the tail, we should blow up. Rather than catch this case here,
1181 * we depend on other ASSERTions in other parts of the code. XXXmiken
1182 *
1183 * This code also handles the case where the reservation head is behind
1184 * the tail. The details of this case are described below, but the end
1185 * result is that we return the size of the log as the amount of space left.
1186 */
1187STATIC int
1188xlog_space_left(
1189 struct xlog *log,
1190 atomic64_t *head)
1191{
1192 int free_bytes;
1193 int tail_bytes;
1194 int tail_cycle;
1195 int head_cycle;
1196 int head_bytes;
1197
1198 xlog_crack_grant_head(head, &head_cycle, &head_bytes);
1199 xlog_crack_atomic_lsn(&log->l_tail_lsn, &tail_cycle, &tail_bytes);
1200 tail_bytes = BBTOB(tail_bytes);
1201 if (tail_cycle == head_cycle && head_bytes >= tail_bytes)
1202 free_bytes = log->l_logsize - (head_bytes - tail_bytes);
1203 else if (tail_cycle + 1 < head_cycle)
1204 return 0;
1205 else if (tail_cycle < head_cycle) {
1206 ASSERT(tail_cycle == (head_cycle - 1));
1207 free_bytes = tail_bytes - head_bytes;
1208 } else {
1209 /*
1210 * The reservation head is behind the tail.
1211 * In this case we just want to return the size of the
1212 * log as the amount of space left.
1213 */
1214 xfs_alert(log->l_mp, "xlog_space_left: head behind tail");
1215 xfs_alert(log->l_mp,
1216 " tail_cycle = %d, tail_bytes = %d",
1217 tail_cycle, tail_bytes);
1218 xfs_alert(log->l_mp,
1219 " GH cycle = %d, GH bytes = %d",
1220 head_cycle, head_bytes);
1221 ASSERT(0);
1222 free_bytes = log->l_logsize;
1223 }
1224 return free_bytes;
1225}
1226
1227
1228static void
1229xlog_ioend_work(
1230 struct work_struct *work)
1231{
1232 struct xlog_in_core *iclog =
1233 container_of(work, struct xlog_in_core, ic_end_io_work);
1234 struct xlog *log = iclog->ic_log;
1235 bool aborted = false;
1236 int error;
1237
1238 error = blk_status_to_errno(iclog->ic_bio.bi_status);
1239#ifdef DEBUG
1240 /* treat writes with injected CRC errors as failed */
1241 if (iclog->ic_fail_crc)
1242 error = -EIO;
1243#endif
1244
1245 /*
1246 * Race to shutdown the filesystem if we see an error.
1247 */
1248 if (XFS_TEST_ERROR(error, log->l_mp, XFS_ERRTAG_IODONE_IOERR)) {
1249 xfs_alert(log->l_mp, "log I/O error %d", error);
1250 xfs_force_shutdown(log->l_mp, SHUTDOWN_LOG_IO_ERROR);
1251 /*
1252 * This flag will be propagated to the trans-committed
1253 * callback routines to let them know that the log-commit
1254 * didn't succeed.
1255 */
1256 aborted = true;
1257 } else if (iclog->ic_state & XLOG_STATE_IOERROR) {
1258 aborted = true;
1259 }
1260
1261 xlog_state_done_syncing(iclog, aborted);
1262 bio_uninit(&iclog->ic_bio);
1263
1264 /*
1265 * Drop the lock to signal that we are done. Nothing references the
1266 * iclog after this, so an unmount waiting on this lock can now tear it
1267 * down safely. As such, it is unsafe to reference the iclog after the
1268 * unlock as we could race with it being freed.
1269 */
1270 up(&iclog->ic_sema);
1271}
1272
1273/*
1274 * Return size of each in-core log record buffer.
1275 *
1276 * All machines get 8 x 32kB buffers by default, unless tuned otherwise.
1277 *
1278 * If the filesystem blocksize is too large, we may need to choose a
1279 * larger size since the directory code currently logs entire blocks.
1280 */
1281STATIC void
1282xlog_get_iclog_buffer_size(
1283 struct xfs_mount *mp,
1284 struct xlog *log)
1285{
1286 if (mp->m_logbufs <= 0)
1287 mp->m_logbufs = XLOG_MAX_ICLOGS;
1288 if (mp->m_logbsize <= 0)
1289 mp->m_logbsize = XLOG_BIG_RECORD_BSIZE;
1290
1291 log->l_iclog_bufs = mp->m_logbufs;
1292 log->l_iclog_size = mp->m_logbsize;
1293
1294 /*
1295 * # headers = size / 32k - one header holds cycles from 32k of data.
1296 */
1297 log->l_iclog_heads =
1298 DIV_ROUND_UP(mp->m_logbsize, XLOG_HEADER_CYCLE_SIZE);
1299 log->l_iclog_hsize = log->l_iclog_heads << BBSHIFT;
1300}
1301
1302void
1303xfs_log_work_queue(
1304 struct xfs_mount *mp)
1305{
1306 queue_delayed_work(mp->m_sync_workqueue, &mp->m_log->l_work,
1307 msecs_to_jiffies(xfs_syncd_centisecs * 10));
1308}
1309
1310/*
1311 * Every sync period we need to unpin all items in the AIL and push them to
1312 * disk. If there is nothing dirty, then we might need to cover the log to
1313 * indicate that the filesystem is idle.
1314 */
1315static void
1316xfs_log_worker(
1317 struct work_struct *work)
1318{
1319 struct xlog *log = container_of(to_delayed_work(work),
1320 struct xlog, l_work);
1321 struct xfs_mount *mp = log->l_mp;
1322
1323 /* dgc: errors ignored - not fatal and nowhere to report them */
1324 if (xfs_log_need_covered(mp)) {
1325 /*
1326 * Dump a transaction into the log that contains no real change.
1327 * This is needed to stamp the current tail LSN into the log
1328 * during the covering operation.
1329 *
1330 * We cannot use an inode here for this - that will push dirty
1331 * state back up into the VFS and then periodic inode flushing
1332 * will prevent log covering from making progress. Hence we
1333 * synchronously log the superblock instead to ensure the
1334 * superblock is immediately unpinned and can be written back.
1335 */
1336 xfs_sync_sb(mp, true);
1337 } else
1338 xfs_log_force(mp, 0);
1339
1340 /* start pushing all the metadata that is currently dirty */
1341 xfs_ail_push_all(mp->m_ail);
1342
1343 /* queue us up again */
1344 xfs_log_work_queue(mp);
1345}
1346
1347/*
1348 * This routine initializes some of the log structure for a given mount point.
1349 * Its primary purpose is to fill in enough, so recovery can occur. However,
1350 * some other stuff may be filled in too.
1351 */
1352STATIC struct xlog *
1353xlog_alloc_log(
1354 struct xfs_mount *mp,
1355 struct xfs_buftarg *log_target,
1356 xfs_daddr_t blk_offset,
1357 int num_bblks)
1358{
1359 struct xlog *log;
1360 xlog_rec_header_t *head;
1361 xlog_in_core_t **iclogp;
1362 xlog_in_core_t *iclog, *prev_iclog=NULL;
1363 int i;
1364 int error = -ENOMEM;
1365 uint log2_size = 0;
1366
1367 log = kmem_zalloc(sizeof(struct xlog), KM_MAYFAIL);
1368 if (!log) {
1369 xfs_warn(mp, "Log allocation failed: No memory!");
1370 goto out;
1371 }
1372
1373 log->l_mp = mp;
1374 log->l_targ = log_target;
1375 log->l_logsize = BBTOB(num_bblks);
1376 log->l_logBBstart = blk_offset;
1377 log->l_logBBsize = num_bblks;
1378 log->l_covered_state = XLOG_STATE_COVER_IDLE;
1379 log->l_flags |= XLOG_ACTIVE_RECOVERY;
1380 INIT_DELAYED_WORK(&log->l_work, xfs_log_worker);
1381
1382 log->l_prev_block = -1;
1383 /* log->l_tail_lsn = 0x100000000LL; cycle = 1; current block = 0 */
1384 xlog_assign_atomic_lsn(&log->l_tail_lsn, 1, 0);
1385 xlog_assign_atomic_lsn(&log->l_last_sync_lsn, 1, 0);
1386 log->l_curr_cycle = 1; /* 0 is bad since this is initial value */
1387
1388 xlog_grant_head_init(&log->l_reserve_head);
1389 xlog_grant_head_init(&log->l_write_head);
1390
1391 error = -EFSCORRUPTED;
1392 if (xfs_sb_version_hassector(&mp->m_sb)) {
1393 log2_size = mp->m_sb.sb_logsectlog;
1394 if (log2_size < BBSHIFT) {
1395 xfs_warn(mp, "Log sector size too small (0x%x < 0x%x)",
1396 log2_size, BBSHIFT);
1397 goto out_free_log;
1398 }
1399
1400 log2_size -= BBSHIFT;
1401 if (log2_size > mp->m_sectbb_log) {
1402 xfs_warn(mp, "Log sector size too large (0x%x > 0x%x)",
1403 log2_size, mp->m_sectbb_log);
1404 goto out_free_log;
1405 }
1406
1407 /* for larger sector sizes, must have v2 or external log */
1408 if (log2_size && log->l_logBBstart > 0 &&
1409 !xfs_sb_version_haslogv2(&mp->m_sb)) {
1410 xfs_warn(mp,
1411 "log sector size (0x%x) invalid for configuration.",
1412 log2_size);
1413 goto out_free_log;
1414 }
1415 }
1416 log->l_sectBBsize = 1 << log2_size;
1417
1418 xlog_get_iclog_buffer_size(mp, log);
1419
1420 spin_lock_init(&log->l_icloglock);
1421 init_waitqueue_head(&log->l_flush_wait);
1422
1423 iclogp = &log->l_iclog;
1424 /*
1425 * The amount of memory to allocate for the iclog structure is
1426 * rather funky due to the way the structure is defined. It is
1427 * done this way so that we can use different sizes for machines
1428 * with different amounts of memory. See the definition of
1429 * xlog_in_core_t in xfs_log_priv.h for details.
1430 */
1431 ASSERT(log->l_iclog_size >= 4096);
1432 for (i = 0; i < log->l_iclog_bufs; i++) {
1433 int align_mask = xfs_buftarg_dma_alignment(mp->m_logdev_targp);
1434 size_t bvec_size = howmany(log->l_iclog_size, PAGE_SIZE) *
1435 sizeof(struct bio_vec);
1436
1437 iclog = kmem_zalloc(sizeof(*iclog) + bvec_size, KM_MAYFAIL);
1438 if (!iclog)
1439 goto out_free_iclog;
1440
1441 *iclogp = iclog;
1442 iclog->ic_prev = prev_iclog;
1443 prev_iclog = iclog;
1444
1445 iclog->ic_data = kmem_alloc_io(log->l_iclog_size, align_mask,
1446 KM_MAYFAIL | KM_ZERO);
1447 if (!iclog->ic_data)
1448 goto out_free_iclog;
1449#ifdef DEBUG
1450 log->l_iclog_bak[i] = &iclog->ic_header;
1451#endif
1452 head = &iclog->ic_header;
1453 memset(head, 0, sizeof(xlog_rec_header_t));
1454 head->h_magicno = cpu_to_be32(XLOG_HEADER_MAGIC_NUM);
1455 head->h_version = cpu_to_be32(
1456 xfs_sb_version_haslogv2(&log->l_mp->m_sb) ? 2 : 1);
1457 head->h_size = cpu_to_be32(log->l_iclog_size);
1458 /* new fields */
1459 head->h_fmt = cpu_to_be32(XLOG_FMT);
1460 memcpy(&head->h_fs_uuid, &mp->m_sb.sb_uuid, sizeof(uuid_t));
1461
1462 iclog->ic_size = log->l_iclog_size - log->l_iclog_hsize;
1463 iclog->ic_state = XLOG_STATE_ACTIVE;
1464 iclog->ic_log = log;
1465 atomic_set(&iclog->ic_refcnt, 0);
1466 spin_lock_init(&iclog->ic_callback_lock);
1467 INIT_LIST_HEAD(&iclog->ic_callbacks);
1468 iclog->ic_datap = (char *)iclog->ic_data + log->l_iclog_hsize;
1469
1470 init_waitqueue_head(&iclog->ic_force_wait);
1471 init_waitqueue_head(&iclog->ic_write_wait);
1472 INIT_WORK(&iclog->ic_end_io_work, xlog_ioend_work);
1473 sema_init(&iclog->ic_sema, 1);
1474
1475 iclogp = &iclog->ic_next;
1476 }
1477 *iclogp = log->l_iclog; /* complete ring */
1478 log->l_iclog->ic_prev = prev_iclog; /* re-write 1st prev ptr */
1479
1480 log->l_ioend_workqueue = alloc_workqueue("xfs-log/%s",
1481 WQ_MEM_RECLAIM | WQ_FREEZABLE | WQ_HIGHPRI, 0,
1482 mp->m_fsname);
1483 if (!log->l_ioend_workqueue)
1484 goto out_free_iclog;
1485
1486 error = xlog_cil_init(log);
1487 if (error)
1488 goto out_destroy_workqueue;
1489 return log;
1490
1491out_destroy_workqueue:
1492 destroy_workqueue(log->l_ioend_workqueue);
1493out_free_iclog:
1494 for (iclog = log->l_iclog; iclog; iclog = prev_iclog) {
1495 prev_iclog = iclog->ic_next;
1496 kmem_free(iclog->ic_data);
1497 kmem_free(iclog);
1498 }
1499out_free_log:
1500 kmem_free(log);
1501out:
1502 return ERR_PTR(error);
1503} /* xlog_alloc_log */
1504
1505
1506/*
1507 * Write out the commit record of a transaction associated with the given
1508 * ticket. Return the lsn of the commit record.
1509 */
1510STATIC int
1511xlog_commit_record(
1512 struct xlog *log,
1513 struct xlog_ticket *ticket,
1514 struct xlog_in_core **iclog,
1515 xfs_lsn_t *commitlsnp)
1516{
1517 struct xfs_mount *mp = log->l_mp;
1518 int error;
1519 struct xfs_log_iovec reg = {
1520 .i_addr = NULL,
1521 .i_len = 0,
1522 .i_type = XLOG_REG_TYPE_COMMIT,
1523 };
1524 struct xfs_log_vec vec = {
1525 .lv_niovecs = 1,
1526 .lv_iovecp = ®,
1527 };
1528
1529 ASSERT_ALWAYS(iclog);
1530 error = xlog_write(log, &vec, ticket, commitlsnp, iclog,
1531 XLOG_COMMIT_TRANS);
1532 if (error)
1533 xfs_force_shutdown(mp, SHUTDOWN_LOG_IO_ERROR);
1534 return error;
1535}
1536
1537/*
1538 * Push on the buffer cache code if we ever use more than 75% of the on-disk
1539 * log space. This code pushes on the lsn which would supposedly free up
1540 * the 25% which we want to leave free. We may need to adopt a policy which
1541 * pushes on an lsn which is further along in the log once we reach the high
1542 * water mark. In this manner, we would be creating a low water mark.
1543 */
1544STATIC void
1545xlog_grant_push_ail(
1546 struct xlog *log,
1547 int need_bytes)
1548{
1549 xfs_lsn_t threshold_lsn = 0;
1550 xfs_lsn_t last_sync_lsn;
1551 int free_blocks;
1552 int free_bytes;
1553 int threshold_block;
1554 int threshold_cycle;
1555 int free_threshold;
1556
1557 ASSERT(BTOBB(need_bytes) < log->l_logBBsize);
1558
1559 free_bytes = xlog_space_left(log, &log->l_reserve_head.grant);
1560 free_blocks = BTOBBT(free_bytes);
1561
1562 /*
1563 * Set the threshold for the minimum number of free blocks in the
1564 * log to the maximum of what the caller needs, one quarter of the
1565 * log, and 256 blocks.
1566 */
1567 free_threshold = BTOBB(need_bytes);
1568 free_threshold = max(free_threshold, (log->l_logBBsize >> 2));
1569 free_threshold = max(free_threshold, 256);
1570 if (free_blocks >= free_threshold)
1571 return;
1572
1573 xlog_crack_atomic_lsn(&log->l_tail_lsn, &threshold_cycle,
1574 &threshold_block);
1575 threshold_block += free_threshold;
1576 if (threshold_block >= log->l_logBBsize) {
1577 threshold_block -= log->l_logBBsize;
1578 threshold_cycle += 1;
1579 }
1580 threshold_lsn = xlog_assign_lsn(threshold_cycle,
1581 threshold_block);
1582 /*
1583 * Don't pass in an lsn greater than the lsn of the last
1584 * log record known to be on disk. Use a snapshot of the last sync lsn
1585 * so that it doesn't change between the compare and the set.
1586 */
1587 last_sync_lsn = atomic64_read(&log->l_last_sync_lsn);
1588 if (XFS_LSN_CMP(threshold_lsn, last_sync_lsn) > 0)
1589 threshold_lsn = last_sync_lsn;
1590
1591 /*
1592 * Get the transaction layer to kick the dirty buffers out to
1593 * disk asynchronously. No point in trying to do this if
1594 * the filesystem is shutting down.
1595 */
1596 if (!XLOG_FORCED_SHUTDOWN(log))
1597 xfs_ail_push(log->l_ailp, threshold_lsn);
1598}
1599
1600/*
1601 * Stamp cycle number in every block
1602 */
1603STATIC void
1604xlog_pack_data(
1605 struct xlog *log,
1606 struct xlog_in_core *iclog,
1607 int roundoff)
1608{
1609 int i, j, k;
1610 int size = iclog->ic_offset + roundoff;
1611 __be32 cycle_lsn;
1612 char *dp;
1613
1614 cycle_lsn = CYCLE_LSN_DISK(iclog->ic_header.h_lsn);
1615
1616 dp = iclog->ic_datap;
1617 for (i = 0; i < BTOBB(size); i++) {
1618 if (i >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE))
1619 break;
1620 iclog->ic_header.h_cycle_data[i] = *(__be32 *)dp;
1621 *(__be32 *)dp = cycle_lsn;
1622 dp += BBSIZE;
1623 }
1624
1625 if (xfs_sb_version_haslogv2(&log->l_mp->m_sb)) {
1626 xlog_in_core_2_t *xhdr = iclog->ic_data;
1627
1628 for ( ; i < BTOBB(size); i++) {
1629 j = i / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
1630 k = i % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
1631 xhdr[j].hic_xheader.xh_cycle_data[k] = *(__be32 *)dp;
1632 *(__be32 *)dp = cycle_lsn;
1633 dp += BBSIZE;
1634 }
1635
1636 for (i = 1; i < log->l_iclog_heads; i++)
1637 xhdr[i].hic_xheader.xh_cycle = cycle_lsn;
1638 }
1639}
1640
1641/*
1642 * Calculate the checksum for a log buffer.
1643 *
1644 * This is a little more complicated than it should be because the various
1645 * headers and the actual data are non-contiguous.
1646 */
1647__le32
1648xlog_cksum(
1649 struct xlog *log,
1650 struct xlog_rec_header *rhead,
1651 char *dp,
1652 int size)
1653{
1654 uint32_t crc;
1655
1656 /* first generate the crc for the record header ... */
1657 crc = xfs_start_cksum_update((char *)rhead,
1658 sizeof(struct xlog_rec_header),
1659 offsetof(struct xlog_rec_header, h_crc));
1660
1661 /* ... then for additional cycle data for v2 logs ... */
1662 if (xfs_sb_version_haslogv2(&log->l_mp->m_sb)) {
1663 union xlog_in_core2 *xhdr = (union xlog_in_core2 *)rhead;
1664 int i;
1665 int xheads;
1666
1667 xheads = size / XLOG_HEADER_CYCLE_SIZE;
1668 if (size % XLOG_HEADER_CYCLE_SIZE)
1669 xheads++;
1670
1671 for (i = 1; i < xheads; i++) {
1672 crc = crc32c(crc, &xhdr[i].hic_xheader,
1673 sizeof(struct xlog_rec_ext_header));
1674 }
1675 }
1676
1677 /* ... and finally for the payload */
1678 crc = crc32c(crc, dp, size);
1679
1680 return xfs_end_cksum(crc);
1681}
1682
1683static void
1684xlog_bio_end_io(
1685 struct bio *bio)
1686{
1687 struct xlog_in_core *iclog = bio->bi_private;
1688
1689 queue_work(iclog->ic_log->l_ioend_workqueue,
1690 &iclog->ic_end_io_work);
1691}
1692
1693static void
1694xlog_map_iclog_data(
1695 struct bio *bio,
1696 void *data,
1697 size_t count)
1698{
1699 do {
1700 struct page *page = kmem_to_page(data);
1701 unsigned int off = offset_in_page(data);
1702 size_t len = min_t(size_t, count, PAGE_SIZE - off);
1703
1704 WARN_ON_ONCE(bio_add_page(bio, page, len, off) != len);
1705
1706 data += len;
1707 count -= len;
1708 } while (count);
1709}
1710
1711STATIC void
1712xlog_write_iclog(
1713 struct xlog *log,
1714 struct xlog_in_core *iclog,
1715 uint64_t bno,
1716 unsigned int count,
1717 bool need_flush)
1718{
1719 ASSERT(bno < log->l_logBBsize);
1720
1721 /*
1722 * We lock the iclogbufs here so that we can serialise against I/O
1723 * completion during unmount. We might be processing a shutdown
1724 * triggered during unmount, and that can occur asynchronously to the
1725 * unmount thread, and hence we need to ensure that completes before
1726 * tearing down the iclogbufs. Hence we need to hold the buffer lock
1727 * across the log IO to archieve that.
1728 */
1729 down(&iclog->ic_sema);
1730 if (unlikely(iclog->ic_state & XLOG_STATE_IOERROR)) {
1731 /*
1732 * It would seem logical to return EIO here, but we rely on
1733 * the log state machine to propagate I/O errors instead of
1734 * doing it here. We kick of the state machine and unlock
1735 * the buffer manually, the code needs to be kept in sync
1736 * with the I/O completion path.
1737 */
1738 xlog_state_done_syncing(iclog, XFS_LI_ABORTED);
1739 up(&iclog->ic_sema);
1740 return;
1741 }
1742
1743 iclog->ic_io_size = count;
1744
1745 bio_init(&iclog->ic_bio, iclog->ic_bvec, howmany(count, PAGE_SIZE));
1746 bio_set_dev(&iclog->ic_bio, log->l_targ->bt_bdev);
1747 iclog->ic_bio.bi_iter.bi_sector = log->l_logBBstart + bno;
1748 iclog->ic_bio.bi_end_io = xlog_bio_end_io;
1749 iclog->ic_bio.bi_private = iclog;
1750 iclog->ic_bio.bi_opf = REQ_OP_WRITE | REQ_META | REQ_SYNC | REQ_FUA;
1751 if (need_flush)
1752 iclog->ic_bio.bi_opf |= REQ_PREFLUSH;
1753
1754 xlog_map_iclog_data(&iclog->ic_bio, iclog->ic_data, iclog->ic_io_size);
1755 if (is_vmalloc_addr(iclog->ic_data))
1756 flush_kernel_vmap_range(iclog->ic_data, iclog->ic_io_size);
1757
1758 /*
1759 * If this log buffer would straddle the end of the log we will have
1760 * to split it up into two bios, so that we can continue at the start.
1761 */
1762 if (bno + BTOBB(count) > log->l_logBBsize) {
1763 struct bio *split;
1764
1765 split = bio_split(&iclog->ic_bio, log->l_logBBsize - bno,
1766 GFP_NOIO, &fs_bio_set);
1767 bio_chain(split, &iclog->ic_bio);
1768 submit_bio(split);
1769
1770 /* restart at logical offset zero for the remainder */
1771 iclog->ic_bio.bi_iter.bi_sector = log->l_logBBstart;
1772 }
1773
1774 submit_bio(&iclog->ic_bio);
1775}
1776
1777/*
1778 * We need to bump cycle number for the part of the iclog that is
1779 * written to the start of the log. Watch out for the header magic
1780 * number case, though.
1781 */
1782static void
1783xlog_split_iclog(
1784 struct xlog *log,
1785 void *data,
1786 uint64_t bno,
1787 unsigned int count)
1788{
1789 unsigned int split_offset = BBTOB(log->l_logBBsize - bno);
1790 unsigned int i;
1791
1792 for (i = split_offset; i < count; i += BBSIZE) {
1793 uint32_t cycle = get_unaligned_be32(data + i);
1794
1795 if (++cycle == XLOG_HEADER_MAGIC_NUM)
1796 cycle++;
1797 put_unaligned_be32(cycle, data + i);
1798 }
1799}
1800
1801static int
1802xlog_calc_iclog_size(
1803 struct xlog *log,
1804 struct xlog_in_core *iclog,
1805 uint32_t *roundoff)
1806{
1807 uint32_t count_init, count;
1808 bool use_lsunit;
1809
1810 use_lsunit = xfs_sb_version_haslogv2(&log->l_mp->m_sb) &&
1811 log->l_mp->m_sb.sb_logsunit > 1;
1812
1813 /* Add for LR header */
1814 count_init = log->l_iclog_hsize + iclog->ic_offset;
1815
1816 /* Round out the log write size */
1817 if (use_lsunit) {
1818 /* we have a v2 stripe unit to use */
1819 count = XLOG_LSUNITTOB(log, XLOG_BTOLSUNIT(log, count_init));
1820 } else {
1821 count = BBTOB(BTOBB(count_init));
1822 }
1823
1824 ASSERT(count >= count_init);
1825 *roundoff = count - count_init;
1826
1827 if (use_lsunit)
1828 ASSERT(*roundoff < log->l_mp->m_sb.sb_logsunit);
1829 else
1830 ASSERT(*roundoff < BBTOB(1));
1831 return count;
1832}
1833
1834/*
1835 * Flush out the in-core log (iclog) to the on-disk log in an asynchronous
1836 * fashion. Previously, we should have moved the current iclog
1837 * ptr in the log to point to the next available iclog. This allows further
1838 * write to continue while this code syncs out an iclog ready to go.
1839 * Before an in-core log can be written out, the data section must be scanned
1840 * to save away the 1st word of each BBSIZE block into the header. We replace
1841 * it with the current cycle count. Each BBSIZE block is tagged with the
1842 * cycle count because there in an implicit assumption that drives will
1843 * guarantee that entire 512 byte blocks get written at once. In other words,
1844 * we can't have part of a 512 byte block written and part not written. By
1845 * tagging each block, we will know which blocks are valid when recovering
1846 * after an unclean shutdown.
1847 *
1848 * This routine is single threaded on the iclog. No other thread can be in
1849 * this routine with the same iclog. Changing contents of iclog can there-
1850 * fore be done without grabbing the state machine lock. Updating the global
1851 * log will require grabbing the lock though.
1852 *
1853 * The entire log manager uses a logical block numbering scheme. Only
1854 * xlog_write_iclog knows about the fact that the log may not start with
1855 * block zero on a given device.
1856 */
1857STATIC void
1858xlog_sync(
1859 struct xlog *log,
1860 struct xlog_in_core *iclog)
1861{
1862 unsigned int count; /* byte count of bwrite */
1863 unsigned int roundoff; /* roundoff to BB or stripe */
1864 uint64_t bno;
1865 unsigned int size;
1866 bool need_flush = true, split = false;
1867
1868 ASSERT(atomic_read(&iclog->ic_refcnt) == 0);
1869
1870 count = xlog_calc_iclog_size(log, iclog, &roundoff);
1871
1872 /* move grant heads by roundoff in sync */
1873 xlog_grant_add_space(log, &log->l_reserve_head.grant, roundoff);
1874 xlog_grant_add_space(log, &log->l_write_head.grant, roundoff);
1875
1876 /* put cycle number in every block */
1877 xlog_pack_data(log, iclog, roundoff);
1878
1879 /* real byte length */
1880 size = iclog->ic_offset;
1881 if (xfs_sb_version_haslogv2(&log->l_mp->m_sb))
1882 size += roundoff;
1883 iclog->ic_header.h_len = cpu_to_be32(size);
1884
1885 XFS_STATS_INC(log->l_mp, xs_log_writes);
1886 XFS_STATS_ADD(log->l_mp, xs_log_blocks, BTOBB(count));
1887
1888 bno = BLOCK_LSN(be64_to_cpu(iclog->ic_header.h_lsn));
1889
1890 /* Do we need to split this write into 2 parts? */
1891 if (bno + BTOBB(count) > log->l_logBBsize) {
1892 xlog_split_iclog(log, &iclog->ic_header, bno, count);
1893 split = true;
1894 }
1895
1896 /* calculcate the checksum */
1897 iclog->ic_header.h_crc = xlog_cksum(log, &iclog->ic_header,
1898 iclog->ic_datap, size);
1899 /*
1900 * Intentionally corrupt the log record CRC based on the error injection
1901 * frequency, if defined. This facilitates testing log recovery in the
1902 * event of torn writes. Hence, set the IOABORT state to abort the log
1903 * write on I/O completion and shutdown the fs. The subsequent mount
1904 * detects the bad CRC and attempts to recover.
1905 */
1906#ifdef DEBUG
1907 if (XFS_TEST_ERROR(false, log->l_mp, XFS_ERRTAG_LOG_BAD_CRC)) {
1908 iclog->ic_header.h_crc &= cpu_to_le32(0xAAAAAAAA);
1909 iclog->ic_fail_crc = true;
1910 xfs_warn(log->l_mp,
1911 "Intentionally corrupted log record at LSN 0x%llx. Shutdown imminent.",
1912 be64_to_cpu(iclog->ic_header.h_lsn));
1913 }
1914#endif
1915
1916 /*
1917 * Flush the data device before flushing the log to make sure all meta
1918 * data written back from the AIL actually made it to disk before
1919 * stamping the new log tail LSN into the log buffer. For an external
1920 * log we need to issue the flush explicitly, and unfortunately
1921 * synchronously here; for an internal log we can simply use the block
1922 * layer state machine for preflushes.
1923 */
1924 if (log->l_targ != log->l_mp->m_ddev_targp || split) {
1925 xfs_blkdev_issue_flush(log->l_mp->m_ddev_targp);
1926 need_flush = false;
1927 }
1928
1929 xlog_verify_iclog(log, iclog, count);
1930 xlog_write_iclog(log, iclog, bno, count, need_flush);
1931}
1932
1933/*
1934 * Deallocate a log structure
1935 */
1936STATIC void
1937xlog_dealloc_log(
1938 struct xlog *log)
1939{
1940 xlog_in_core_t *iclog, *next_iclog;
1941 int i;
1942
1943 xlog_cil_destroy(log);
1944
1945 /*
1946 * Cycle all the iclogbuf locks to make sure all log IO completion
1947 * is done before we tear down these buffers.
1948 */
1949 iclog = log->l_iclog;
1950 for (i = 0; i < log->l_iclog_bufs; i++) {
1951 down(&iclog->ic_sema);
1952 up(&iclog->ic_sema);
1953 iclog = iclog->ic_next;
1954 }
1955
1956 iclog = log->l_iclog;
1957 for (i = 0; i < log->l_iclog_bufs; i++) {
1958 next_iclog = iclog->ic_next;
1959 kmem_free(iclog->ic_data);
1960 kmem_free(iclog);
1961 iclog = next_iclog;
1962 }
1963
1964 log->l_mp->m_log = NULL;
1965 destroy_workqueue(log->l_ioend_workqueue);
1966 kmem_free(log);
1967} /* xlog_dealloc_log */
1968
1969/*
1970 * Update counters atomically now that memcpy is done.
1971 */
1972/* ARGSUSED */
1973static inline void
1974xlog_state_finish_copy(
1975 struct xlog *log,
1976 struct xlog_in_core *iclog,
1977 int record_cnt,
1978 int copy_bytes)
1979{
1980 spin_lock(&log->l_icloglock);
1981
1982 be32_add_cpu(&iclog->ic_header.h_num_logops, record_cnt);
1983 iclog->ic_offset += copy_bytes;
1984
1985 spin_unlock(&log->l_icloglock);
1986} /* xlog_state_finish_copy */
1987
1988
1989
1990
1991/*
1992 * print out info relating to regions written which consume
1993 * the reservation
1994 */
1995void
1996xlog_print_tic_res(
1997 struct xfs_mount *mp,
1998 struct xlog_ticket *ticket)
1999{
2000 uint i;
2001 uint ophdr_spc = ticket->t_res_num_ophdrs * (uint)sizeof(xlog_op_header_t);
2002
2003 /* match with XLOG_REG_TYPE_* in xfs_log.h */
2004#define REG_TYPE_STR(type, str) [XLOG_REG_TYPE_##type] = str
2005 static char *res_type_str[] = {
2006 REG_TYPE_STR(BFORMAT, "bformat"),
2007 REG_TYPE_STR(BCHUNK, "bchunk"),
2008 REG_TYPE_STR(EFI_FORMAT, "efi_format"),
2009 REG_TYPE_STR(EFD_FORMAT, "efd_format"),
2010 REG_TYPE_STR(IFORMAT, "iformat"),
2011 REG_TYPE_STR(ICORE, "icore"),
2012 REG_TYPE_STR(IEXT, "iext"),
2013 REG_TYPE_STR(IBROOT, "ibroot"),
2014 REG_TYPE_STR(ILOCAL, "ilocal"),
2015 REG_TYPE_STR(IATTR_EXT, "iattr_ext"),
2016 REG_TYPE_STR(IATTR_BROOT, "iattr_broot"),
2017 REG_TYPE_STR(IATTR_LOCAL, "iattr_local"),
2018 REG_TYPE_STR(QFORMAT, "qformat"),
2019 REG_TYPE_STR(DQUOT, "dquot"),
2020 REG_TYPE_STR(QUOTAOFF, "quotaoff"),
2021 REG_TYPE_STR(LRHEADER, "LR header"),
2022 REG_TYPE_STR(UNMOUNT, "unmount"),
2023 REG_TYPE_STR(COMMIT, "commit"),
2024 REG_TYPE_STR(TRANSHDR, "trans header"),
2025 REG_TYPE_STR(ICREATE, "inode create"),
2026 REG_TYPE_STR(RUI_FORMAT, "rui_format"),
2027 REG_TYPE_STR(RUD_FORMAT, "rud_format"),
2028 REG_TYPE_STR(CUI_FORMAT, "cui_format"),
2029 REG_TYPE_STR(CUD_FORMAT, "cud_format"),
2030 REG_TYPE_STR(BUI_FORMAT, "bui_format"),
2031 REG_TYPE_STR(BUD_FORMAT, "bud_format"),
2032 };
2033 BUILD_BUG_ON(ARRAY_SIZE(res_type_str) != XLOG_REG_TYPE_MAX + 1);
2034#undef REG_TYPE_STR
2035
2036 xfs_warn(mp, "ticket reservation summary:");
2037 xfs_warn(mp, " unit res = %d bytes",
2038 ticket->t_unit_res);
2039 xfs_warn(mp, " current res = %d bytes",
2040 ticket->t_curr_res);
2041 xfs_warn(mp, " total reg = %u bytes (o/flow = %u bytes)",
2042 ticket->t_res_arr_sum, ticket->t_res_o_flow);
2043 xfs_warn(mp, " ophdrs = %u (ophdr space = %u bytes)",
2044 ticket->t_res_num_ophdrs, ophdr_spc);
2045 xfs_warn(mp, " ophdr + reg = %u bytes",
2046 ticket->t_res_arr_sum + ticket->t_res_o_flow + ophdr_spc);
2047 xfs_warn(mp, " num regions = %u",
2048 ticket->t_res_num);
2049
2050 for (i = 0; i < ticket->t_res_num; i++) {
2051 uint r_type = ticket->t_res_arr[i].r_type;
2052 xfs_warn(mp, "region[%u]: %s - %u bytes", i,
2053 ((r_type <= 0 || r_type > XLOG_REG_TYPE_MAX) ?
2054 "bad-rtype" : res_type_str[r_type]),
2055 ticket->t_res_arr[i].r_len);
2056 }
2057}
2058
2059/*
2060 * Print a summary of the transaction.
2061 */
2062void
2063xlog_print_trans(
2064 struct xfs_trans *tp)
2065{
2066 struct xfs_mount *mp = tp->t_mountp;
2067 struct xfs_log_item *lip;
2068
2069 /* dump core transaction and ticket info */
2070 xfs_warn(mp, "transaction summary:");
2071 xfs_warn(mp, " log res = %d", tp->t_log_res);
2072 xfs_warn(mp, " log count = %d", tp->t_log_count);
2073 xfs_warn(mp, " flags = 0x%x", tp->t_flags);
2074
2075 xlog_print_tic_res(mp, tp->t_ticket);
2076
2077 /* dump each log item */
2078 list_for_each_entry(lip, &tp->t_items, li_trans) {
2079 struct xfs_log_vec *lv = lip->li_lv;
2080 struct xfs_log_iovec *vec;
2081 int i;
2082
2083 xfs_warn(mp, "log item: ");
2084 xfs_warn(mp, " type = 0x%x", lip->li_type);
2085 xfs_warn(mp, " flags = 0x%lx", lip->li_flags);
2086 if (!lv)
2087 continue;
2088 xfs_warn(mp, " niovecs = %d", lv->lv_niovecs);
2089 xfs_warn(mp, " size = %d", lv->lv_size);
2090 xfs_warn(mp, " bytes = %d", lv->lv_bytes);
2091 xfs_warn(mp, " buf len = %d", lv->lv_buf_len);
2092
2093 /* dump each iovec for the log item */
2094 vec = lv->lv_iovecp;
2095 for (i = 0; i < lv->lv_niovecs; i++) {
2096 int dumplen = min(vec->i_len, 32);
2097
2098 xfs_warn(mp, " iovec[%d]", i);
2099 xfs_warn(mp, " type = 0x%x", vec->i_type);
2100 xfs_warn(mp, " len = %d", vec->i_len);
2101 xfs_warn(mp, " first %d bytes of iovec[%d]:", dumplen, i);
2102 xfs_hex_dump(vec->i_addr, dumplen);
2103
2104 vec++;
2105 }
2106 }
2107}
2108
2109/*
2110 * Calculate the potential space needed by the log vector. Each region gets
2111 * its own xlog_op_header_t and may need to be double word aligned.
2112 */
2113static int
2114xlog_write_calc_vec_length(
2115 struct xlog_ticket *ticket,
2116 struct xfs_log_vec *log_vector)
2117{
2118 struct xfs_log_vec *lv;
2119 int headers = 0;
2120 int len = 0;
2121 int i;
2122
2123 /* acct for start rec of xact */
2124 if (ticket->t_flags & XLOG_TIC_INITED)
2125 headers++;
2126
2127 for (lv = log_vector; lv; lv = lv->lv_next) {
2128 /* we don't write ordered log vectors */
2129 if (lv->lv_buf_len == XFS_LOG_VEC_ORDERED)
2130 continue;
2131
2132 headers += lv->lv_niovecs;
2133
2134 for (i = 0; i < lv->lv_niovecs; i++) {
2135 struct xfs_log_iovec *vecp = &lv->lv_iovecp[i];
2136
2137 len += vecp->i_len;
2138 xlog_tic_add_region(ticket, vecp->i_len, vecp->i_type);
2139 }
2140 }
2141
2142 ticket->t_res_num_ophdrs += headers;
2143 len += headers * sizeof(struct xlog_op_header);
2144
2145 return len;
2146}
2147
2148/*
2149 * If first write for transaction, insert start record We can't be trying to
2150 * commit if we are inited. We can't have any "partial_copy" if we are inited.
2151 */
2152static int
2153xlog_write_start_rec(
2154 struct xlog_op_header *ophdr,
2155 struct xlog_ticket *ticket)
2156{
2157 if (!(ticket->t_flags & XLOG_TIC_INITED))
2158 return 0;
2159
2160 ophdr->oh_tid = cpu_to_be32(ticket->t_tid);
2161 ophdr->oh_clientid = ticket->t_clientid;
2162 ophdr->oh_len = 0;
2163 ophdr->oh_flags = XLOG_START_TRANS;
2164 ophdr->oh_res2 = 0;
2165
2166 ticket->t_flags &= ~XLOG_TIC_INITED;
2167
2168 return sizeof(struct xlog_op_header);
2169}
2170
2171static xlog_op_header_t *
2172xlog_write_setup_ophdr(
2173 struct xlog *log,
2174 struct xlog_op_header *ophdr,
2175 struct xlog_ticket *ticket,
2176 uint flags)
2177{
2178 ophdr->oh_tid = cpu_to_be32(ticket->t_tid);
2179 ophdr->oh_clientid = ticket->t_clientid;
2180 ophdr->oh_res2 = 0;
2181
2182 /* are we copying a commit or unmount record? */
2183 ophdr->oh_flags = flags;
2184
2185 /*
2186 * We've seen logs corrupted with bad transaction client ids. This
2187 * makes sure that XFS doesn't generate them on. Turn this into an EIO
2188 * and shut down the filesystem.
2189 */
2190 switch (ophdr->oh_clientid) {
2191 case XFS_TRANSACTION:
2192 case XFS_VOLUME:
2193 case XFS_LOG:
2194 break;
2195 default:
2196 xfs_warn(log->l_mp,
2197 "Bad XFS transaction clientid 0x%x in ticket "PTR_FMT,
2198 ophdr->oh_clientid, ticket);
2199 return NULL;
2200 }
2201
2202 return ophdr;
2203}
2204
2205/*
2206 * Set up the parameters of the region copy into the log. This has
2207 * to handle region write split across multiple log buffers - this
2208 * state is kept external to this function so that this code can
2209 * be written in an obvious, self documenting manner.
2210 */
2211static int
2212xlog_write_setup_copy(
2213 struct xlog_ticket *ticket,
2214 struct xlog_op_header *ophdr,
2215 int space_available,
2216 int space_required,
2217 int *copy_off,
2218 int *copy_len,
2219 int *last_was_partial_copy,
2220 int *bytes_consumed)
2221{
2222 int still_to_copy;
2223
2224 still_to_copy = space_required - *bytes_consumed;
2225 *copy_off = *bytes_consumed;
2226
2227 if (still_to_copy <= space_available) {
2228 /* write of region completes here */
2229 *copy_len = still_to_copy;
2230 ophdr->oh_len = cpu_to_be32(*copy_len);
2231 if (*last_was_partial_copy)
2232 ophdr->oh_flags |= (XLOG_END_TRANS|XLOG_WAS_CONT_TRANS);
2233 *last_was_partial_copy = 0;
2234 *bytes_consumed = 0;
2235 return 0;
2236 }
2237
2238 /* partial write of region, needs extra log op header reservation */
2239 *copy_len = space_available;
2240 ophdr->oh_len = cpu_to_be32(*copy_len);
2241 ophdr->oh_flags |= XLOG_CONTINUE_TRANS;
2242 if (*last_was_partial_copy)
2243 ophdr->oh_flags |= XLOG_WAS_CONT_TRANS;
2244 *bytes_consumed += *copy_len;
2245 (*last_was_partial_copy)++;
2246
2247 /* account for new log op header */
2248 ticket->t_curr_res -= sizeof(struct xlog_op_header);
2249 ticket->t_res_num_ophdrs++;
2250
2251 return sizeof(struct xlog_op_header);
2252}
2253
2254static int
2255xlog_write_copy_finish(
2256 struct xlog *log,
2257 struct xlog_in_core *iclog,
2258 uint flags,
2259 int *record_cnt,
2260 int *data_cnt,
2261 int *partial_copy,
2262 int *partial_copy_len,
2263 int log_offset,
2264 struct xlog_in_core **commit_iclog)
2265{
2266 if (*partial_copy) {
2267 /*
2268 * This iclog has already been marked WANT_SYNC by
2269 * xlog_state_get_iclog_space.
2270 */
2271 xlog_state_finish_copy(log, iclog, *record_cnt, *data_cnt);
2272 *record_cnt = 0;
2273 *data_cnt = 0;
2274 return xlog_state_release_iclog(log, iclog);
2275 }
2276
2277 *partial_copy = 0;
2278 *partial_copy_len = 0;
2279
2280 if (iclog->ic_size - log_offset <= sizeof(xlog_op_header_t)) {
2281 /* no more space in this iclog - push it. */
2282 xlog_state_finish_copy(log, iclog, *record_cnt, *data_cnt);
2283 *record_cnt = 0;
2284 *data_cnt = 0;
2285
2286 spin_lock(&log->l_icloglock);
2287 xlog_state_want_sync(log, iclog);
2288 spin_unlock(&log->l_icloglock);
2289
2290 if (!commit_iclog)
2291 return xlog_state_release_iclog(log, iclog);
2292 ASSERT(flags & XLOG_COMMIT_TRANS);
2293 *commit_iclog = iclog;
2294 }
2295
2296 return 0;
2297}
2298
2299/*
2300 * Write some region out to in-core log
2301 *
2302 * This will be called when writing externally provided regions or when
2303 * writing out a commit record for a given transaction.
2304 *
2305 * General algorithm:
2306 * 1. Find total length of this write. This may include adding to the
2307 * lengths passed in.
2308 * 2. Check whether we violate the tickets reservation.
2309 * 3. While writing to this iclog
2310 * A. Reserve as much space in this iclog as can get
2311 * B. If this is first write, save away start lsn
2312 * C. While writing this region:
2313 * 1. If first write of transaction, write start record
2314 * 2. Write log operation header (header per region)
2315 * 3. Find out if we can fit entire region into this iclog
2316 * 4. Potentially, verify destination memcpy ptr
2317 * 5. Memcpy (partial) region
2318 * 6. If partial copy, release iclog; otherwise, continue
2319 * copying more regions into current iclog
2320 * 4. Mark want sync bit (in simulation mode)
2321 * 5. Release iclog for potential flush to on-disk log.
2322 *
2323 * ERRORS:
2324 * 1. Panic if reservation is overrun. This should never happen since
2325 * reservation amounts are generated internal to the filesystem.
2326 * NOTES:
2327 * 1. Tickets are single threaded data structures.
2328 * 2. The XLOG_END_TRANS & XLOG_CONTINUE_TRANS flags are passed down to the
2329 * syncing routine. When a single log_write region needs to span
2330 * multiple in-core logs, the XLOG_CONTINUE_TRANS bit should be set
2331 * on all log operation writes which don't contain the end of the
2332 * region. The XLOG_END_TRANS bit is used for the in-core log
2333 * operation which contains the end of the continued log_write region.
2334 * 3. When xlog_state_get_iclog_space() grabs the rest of the current iclog,
2335 * we don't really know exactly how much space will be used. As a result,
2336 * we don't update ic_offset until the end when we know exactly how many
2337 * bytes have been written out.
2338 */
2339int
2340xlog_write(
2341 struct xlog *log,
2342 struct xfs_log_vec *log_vector,
2343 struct xlog_ticket *ticket,
2344 xfs_lsn_t *start_lsn,
2345 struct xlog_in_core **commit_iclog,
2346 uint flags)
2347{
2348 struct xlog_in_core *iclog = NULL;
2349 struct xfs_log_iovec *vecp;
2350 struct xfs_log_vec *lv;
2351 int len;
2352 int index;
2353 int partial_copy = 0;
2354 int partial_copy_len = 0;
2355 int contwr = 0;
2356 int record_cnt = 0;
2357 int data_cnt = 0;
2358 int error;
2359
2360 *start_lsn = 0;
2361
2362 len = xlog_write_calc_vec_length(ticket, log_vector);
2363
2364 /*
2365 * Region headers and bytes are already accounted for.
2366 * We only need to take into account start records and
2367 * split regions in this function.
2368 */
2369 if (ticket->t_flags & XLOG_TIC_INITED)
2370 ticket->t_curr_res -= sizeof(xlog_op_header_t);
2371
2372 /*
2373 * Commit record headers need to be accounted for. These
2374 * come in as separate writes so are easy to detect.
2375 */
2376 if (flags & (XLOG_COMMIT_TRANS | XLOG_UNMOUNT_TRANS))
2377 ticket->t_curr_res -= sizeof(xlog_op_header_t);
2378
2379 if (ticket->t_curr_res < 0) {
2380 xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES,
2381 "ctx ticket reservation ran out. Need to up reservation");
2382 xlog_print_tic_res(log->l_mp, ticket);
2383 xfs_force_shutdown(log->l_mp, SHUTDOWN_LOG_IO_ERROR);
2384 }
2385
2386 index = 0;
2387 lv = log_vector;
2388 vecp = lv->lv_iovecp;
2389 while (lv && (!lv->lv_niovecs || index < lv->lv_niovecs)) {
2390 void *ptr;
2391 int log_offset;
2392
2393 error = xlog_state_get_iclog_space(log, len, &iclog, ticket,
2394 &contwr, &log_offset);
2395 if (error)
2396 return error;
2397
2398 ASSERT(log_offset <= iclog->ic_size - 1);
2399 ptr = iclog->ic_datap + log_offset;
2400
2401 /* start_lsn is the first lsn written to. That's all we need. */
2402 if (!*start_lsn)
2403 *start_lsn = be64_to_cpu(iclog->ic_header.h_lsn);
2404
2405 /*
2406 * This loop writes out as many regions as can fit in the amount
2407 * of space which was allocated by xlog_state_get_iclog_space().
2408 */
2409 while (lv && (!lv->lv_niovecs || index < lv->lv_niovecs)) {
2410 struct xfs_log_iovec *reg;
2411 struct xlog_op_header *ophdr;
2412 int start_rec_copy;
2413 int copy_len;
2414 int copy_off;
2415 bool ordered = false;
2416
2417 /* ordered log vectors have no regions to write */
2418 if (lv->lv_buf_len == XFS_LOG_VEC_ORDERED) {
2419 ASSERT(lv->lv_niovecs == 0);
2420 ordered = true;
2421 goto next_lv;
2422 }
2423
2424 reg = &vecp[index];
2425 ASSERT(reg->i_len % sizeof(int32_t) == 0);
2426 ASSERT((unsigned long)ptr % sizeof(int32_t) == 0);
2427
2428 start_rec_copy = xlog_write_start_rec(ptr, ticket);
2429 if (start_rec_copy) {
2430 record_cnt++;
2431 xlog_write_adv_cnt(&ptr, &len, &log_offset,
2432 start_rec_copy);
2433 }
2434
2435 ophdr = xlog_write_setup_ophdr(log, ptr, ticket, flags);
2436 if (!ophdr)
2437 return -EIO;
2438
2439 xlog_write_adv_cnt(&ptr, &len, &log_offset,
2440 sizeof(struct xlog_op_header));
2441
2442 len += xlog_write_setup_copy(ticket, ophdr,
2443 iclog->ic_size-log_offset,
2444 reg->i_len,
2445 ©_off, ©_len,
2446 &partial_copy,
2447 &partial_copy_len);
2448 xlog_verify_dest_ptr(log, ptr);
2449
2450 /*
2451 * Copy region.
2452 *
2453 * Unmount records just log an opheader, so can have
2454 * empty payloads with no data region to copy. Hence we
2455 * only copy the payload if the vector says it has data
2456 * to copy.
2457 */
2458 ASSERT(copy_len >= 0);
2459 if (copy_len > 0) {
2460 memcpy(ptr, reg->i_addr + copy_off, copy_len);
2461 xlog_write_adv_cnt(&ptr, &len, &log_offset,
2462 copy_len);
2463 }
2464 copy_len += start_rec_copy + sizeof(xlog_op_header_t);
2465 record_cnt++;
2466 data_cnt += contwr ? copy_len : 0;
2467
2468 error = xlog_write_copy_finish(log, iclog, flags,
2469 &record_cnt, &data_cnt,
2470 &partial_copy,
2471 &partial_copy_len,
2472 log_offset,
2473 commit_iclog);
2474 if (error)
2475 return error;
2476
2477 /*
2478 * if we had a partial copy, we need to get more iclog
2479 * space but we don't want to increment the region
2480 * index because there is still more is this region to
2481 * write.
2482 *
2483 * If we completed writing this region, and we flushed
2484 * the iclog (indicated by resetting of the record
2485 * count), then we also need to get more log space. If
2486 * this was the last record, though, we are done and
2487 * can just return.
2488 */
2489 if (partial_copy)
2490 break;
2491
2492 if (++index == lv->lv_niovecs) {
2493next_lv:
2494 lv = lv->lv_next;
2495 index = 0;
2496 if (lv)
2497 vecp = lv->lv_iovecp;
2498 }
2499 if (record_cnt == 0 && !ordered) {
2500 if (!lv)
2501 return 0;
2502 break;
2503 }
2504 }
2505 }
2506
2507 ASSERT(len == 0);
2508
2509 xlog_state_finish_copy(log, iclog, record_cnt, data_cnt);
2510 if (!commit_iclog)
2511 return xlog_state_release_iclog(log, iclog);
2512
2513 ASSERT(flags & XLOG_COMMIT_TRANS);
2514 *commit_iclog = iclog;
2515 return 0;
2516}
2517
2518
2519/*****************************************************************************
2520 *
2521 * State Machine functions
2522 *
2523 *****************************************************************************
2524 */
2525
2526/*
2527 * An iclog has just finished IO completion processing, so we need to update
2528 * the iclog state and propagate that up into the overall log state. Hence we
2529 * prepare the iclog for cleaning, and then clean all the pending dirty iclogs
2530 * starting from the head, and then wake up any threads that are waiting for the
2531 * iclog to be marked clean.
2532 *
2533 * The ordering of marking iclogs ACTIVE must be maintained, so an iclog
2534 * doesn't become ACTIVE beyond one that is SYNCING. This is also required to
2535 * maintain the notion that we use a ordered wait queue to hold off would be
2536 * writers to the log when every iclog is trying to sync to disk.
2537 *
2538 * Caller must hold the icloglock before calling us.
2539 *
2540 * State Change: !IOERROR -> DIRTY -> ACTIVE
2541 */
2542STATIC void
2543xlog_state_clean_iclog(
2544 struct xlog *log,
2545 struct xlog_in_core *dirty_iclog)
2546{
2547 struct xlog_in_core *iclog;
2548 int changed = 0;
2549
2550 /* Prepare the completed iclog. */
2551 if (!(dirty_iclog->ic_state & XLOG_STATE_IOERROR))
2552 dirty_iclog->ic_state = XLOG_STATE_DIRTY;
2553
2554 /* Walk all the iclogs to update the ordered active state. */
2555 iclog = log->l_iclog;
2556 do {
2557 if (iclog->ic_state == XLOG_STATE_DIRTY) {
2558 iclog->ic_state = XLOG_STATE_ACTIVE;
2559 iclog->ic_offset = 0;
2560 ASSERT(list_empty_careful(&iclog->ic_callbacks));
2561 /*
2562 * If the number of ops in this iclog indicate it just
2563 * contains the dummy transaction, we can
2564 * change state into IDLE (the second time around).
2565 * Otherwise we should change the state into
2566 * NEED a dummy.
2567 * We don't need to cover the dummy.
2568 */
2569 if (!changed &&
2570 (be32_to_cpu(iclog->ic_header.h_num_logops) ==
2571 XLOG_COVER_OPS)) {
2572 changed = 1;
2573 } else {
2574 /*
2575 * We have two dirty iclogs so start over
2576 * This could also be num of ops indicates
2577 * this is not the dummy going out.
2578 */
2579 changed = 2;
2580 }
2581 iclog->ic_header.h_num_logops = 0;
2582 memset(iclog->ic_header.h_cycle_data, 0,
2583 sizeof(iclog->ic_header.h_cycle_data));
2584 iclog->ic_header.h_lsn = 0;
2585 } else if (iclog->ic_state == XLOG_STATE_ACTIVE)
2586 /* do nothing */;
2587 else
2588 break; /* stop cleaning */
2589 iclog = iclog->ic_next;
2590 } while (iclog != log->l_iclog);
2591
2592
2593 /*
2594 * Wake up threads waiting in xfs_log_force() for the dirty iclog
2595 * to be cleaned.
2596 */
2597 wake_up_all(&dirty_iclog->ic_force_wait);
2598
2599 /*
2600 * Change state for the dummy log recording.
2601 * We usually go to NEED. But we go to NEED2 if the changed indicates
2602 * we are done writing the dummy record.
2603 * If we are done with the second dummy recored (DONE2), then
2604 * we go to IDLE.
2605 */
2606 if (changed) {
2607 switch (log->l_covered_state) {
2608 case XLOG_STATE_COVER_IDLE:
2609 case XLOG_STATE_COVER_NEED:
2610 case XLOG_STATE_COVER_NEED2:
2611 log->l_covered_state = XLOG_STATE_COVER_NEED;
2612 break;
2613
2614 case XLOG_STATE_COVER_DONE:
2615 if (changed == 1)
2616 log->l_covered_state = XLOG_STATE_COVER_NEED2;
2617 else
2618 log->l_covered_state = XLOG_STATE_COVER_NEED;
2619 break;
2620
2621 case XLOG_STATE_COVER_DONE2:
2622 if (changed == 1)
2623 log->l_covered_state = XLOG_STATE_COVER_IDLE;
2624 else
2625 log->l_covered_state = XLOG_STATE_COVER_NEED;
2626 break;
2627
2628 default:
2629 ASSERT(0);
2630 }
2631 }
2632}
2633
2634STATIC xfs_lsn_t
2635xlog_get_lowest_lsn(
2636 struct xlog *log)
2637{
2638 struct xlog_in_core *iclog = log->l_iclog;
2639 xfs_lsn_t lowest_lsn = 0, lsn;
2640
2641 do {
2642 if (iclog->ic_state & (XLOG_STATE_ACTIVE | XLOG_STATE_DIRTY))
2643 continue;
2644
2645 lsn = be64_to_cpu(iclog->ic_header.h_lsn);
2646 if ((lsn && !lowest_lsn) || XFS_LSN_CMP(lsn, lowest_lsn) < 0)
2647 lowest_lsn = lsn;
2648 } while ((iclog = iclog->ic_next) != log->l_iclog);
2649
2650 return lowest_lsn;
2651}
2652
2653/*
2654 * Completion of a iclog IO does not imply that a transaction has completed, as
2655 * transactions can be large enough to span many iclogs. We cannot change the
2656 * tail of the log half way through a transaction as this may be the only
2657 * transaction in the log and moving the tail to point to the middle of it
2658 * will prevent recovery from finding the start of the transaction. Hence we
2659 * should only update the last_sync_lsn if this iclog contains transaction
2660 * completion callbacks on it.
2661 *
2662 * We have to do this before we drop the icloglock to ensure we are the only one
2663 * that can update it.
2664 *
2665 * If we are moving the last_sync_lsn forwards, we also need to ensure we kick
2666 * the reservation grant head pushing. This is due to the fact that the push
2667 * target is bound by the current last_sync_lsn value. Hence if we have a large
2668 * amount of log space bound up in this committing transaction then the
2669 * last_sync_lsn value may be the limiting factor preventing tail pushing from
2670 * freeing space in the log. Hence once we've updated the last_sync_lsn we
2671 * should push the AIL to ensure the push target (and hence the grant head) is
2672 * no longer bound by the old log head location and can move forwards and make
2673 * progress again.
2674 */
2675static void
2676xlog_state_set_callback(
2677 struct xlog *log,
2678 struct xlog_in_core *iclog,
2679 xfs_lsn_t header_lsn)
2680{
2681 iclog->ic_state = XLOG_STATE_CALLBACK;
2682
2683 ASSERT(XFS_LSN_CMP(atomic64_read(&log->l_last_sync_lsn),
2684 header_lsn) <= 0);
2685
2686 if (list_empty_careful(&iclog->ic_callbacks))
2687 return;
2688
2689 atomic64_set(&log->l_last_sync_lsn, header_lsn);
2690 xlog_grant_push_ail(log, 0);
2691}
2692
2693/*
2694 * Return true if we need to stop processing, false to continue to the next
2695 * iclog. The caller will need to run callbacks if the iclog is returned in the
2696 * XLOG_STATE_CALLBACK state.
2697 */
2698static bool
2699xlog_state_iodone_process_iclog(
2700 struct xlog *log,
2701 struct xlog_in_core *iclog,
2702 struct xlog_in_core *completed_iclog,
2703 bool *ioerror)
2704{
2705 xfs_lsn_t lowest_lsn;
2706 xfs_lsn_t header_lsn;
2707
2708 /* Skip all iclogs in the ACTIVE & DIRTY states */
2709 if (iclog->ic_state & (XLOG_STATE_ACTIVE | XLOG_STATE_DIRTY))
2710 return false;
2711
2712 /*
2713 * Between marking a filesystem SHUTDOWN and stopping the log, we do
2714 * flush all iclogs to disk (if there wasn't a log I/O error). So, we do
2715 * want things to go smoothly in case of just a SHUTDOWN w/o a
2716 * LOG_IO_ERROR.
2717 */
2718 if (iclog->ic_state & XLOG_STATE_IOERROR) {
2719 *ioerror = true;
2720 return false;
2721 }
2722
2723 /*
2724 * Can only perform callbacks in order. Since this iclog is not in the
2725 * DONE_SYNC/ DO_CALLBACK state, we skip the rest and just try to clean
2726 * up. If we set our iclog to DO_CALLBACK, we will not process it when
2727 * we retry since a previous iclog is in the CALLBACK and the state
2728 * cannot change since we are holding the l_icloglock.
2729 */
2730 if (!(iclog->ic_state &
2731 (XLOG_STATE_DONE_SYNC | XLOG_STATE_DO_CALLBACK))) {
2732 if (completed_iclog &&
2733 (completed_iclog->ic_state == XLOG_STATE_DONE_SYNC)) {
2734 completed_iclog->ic_state = XLOG_STATE_DO_CALLBACK;
2735 }
2736 return true;
2737 }
2738
2739 /*
2740 * We now have an iclog that is in either the DO_CALLBACK or DONE_SYNC
2741 * states. The other states (WANT_SYNC, SYNCING, or CALLBACK were caught
2742 * by the above if and are going to clean (i.e. we aren't doing their
2743 * callbacks) see the above if.
2744 *
2745 * We will do one more check here to see if we have chased our tail
2746 * around. If this is not the lowest lsn iclog, then we will leave it
2747 * for another completion to process.
2748 */
2749 header_lsn = be64_to_cpu(iclog->ic_header.h_lsn);
2750 lowest_lsn = xlog_get_lowest_lsn(log);
2751 if (lowest_lsn && XFS_LSN_CMP(lowest_lsn, header_lsn) < 0)
2752 return false;
2753
2754 xlog_state_set_callback(log, iclog, header_lsn);
2755 return false;
2756
2757}
2758
2759/*
2760 * Keep processing entries in the iclog callback list until we come around and
2761 * it is empty. We need to atomically see that the list is empty and change the
2762 * state to DIRTY so that we don't miss any more callbacks being added.
2763 *
2764 * This function is called with the icloglock held and returns with it held. We
2765 * drop it while running callbacks, however, as holding it over thousands of
2766 * callbacks is unnecessary and causes excessive contention if we do.
2767 */
2768static void
2769xlog_state_do_iclog_callbacks(
2770 struct xlog *log,
2771 struct xlog_in_core *iclog,
2772 bool aborted)
2773{
2774 spin_unlock(&log->l_icloglock);
2775 spin_lock(&iclog->ic_callback_lock);
2776 while (!list_empty(&iclog->ic_callbacks)) {
2777 LIST_HEAD(tmp);
2778
2779 list_splice_init(&iclog->ic_callbacks, &tmp);
2780
2781 spin_unlock(&iclog->ic_callback_lock);
2782 xlog_cil_process_committed(&tmp, aborted);
2783 spin_lock(&iclog->ic_callback_lock);
2784 }
2785
2786 /*
2787 * Pick up the icloglock while still holding the callback lock so we
2788 * serialise against anyone trying to add more callbacks to this iclog
2789 * now we've finished processing.
2790 */
2791 spin_lock(&log->l_icloglock);
2792 spin_unlock(&iclog->ic_callback_lock);
2793}
2794
2795#ifdef DEBUG
2796/*
2797 * Make one last gasp attempt to see if iclogs are being left in limbo. If the
2798 * above loop finds an iclog earlier than the current iclog and in one of the
2799 * syncing states, the current iclog is put into DO_CALLBACK and the callbacks
2800 * are deferred to the completion of the earlier iclog. Walk the iclogs in order
2801 * and make sure that no iclog is in DO_CALLBACK unless an earlier iclog is in
2802 * one of the syncing states.
2803 *
2804 * Note that SYNCING|IOERROR is a valid state so we cannot just check for
2805 * ic_state == SYNCING.
2806 */
2807static void
2808xlog_state_callback_check_state(
2809 struct xlog *log)
2810{
2811 struct xlog_in_core *first_iclog = log->l_iclog;
2812 struct xlog_in_core *iclog = first_iclog;
2813
2814 do {
2815 ASSERT(iclog->ic_state != XLOG_STATE_DO_CALLBACK);
2816 /*
2817 * Terminate the loop if iclogs are found in states
2818 * which will cause other threads to clean up iclogs.
2819 *
2820 * SYNCING - i/o completion will go through logs
2821 * DONE_SYNC - interrupt thread should be waiting for
2822 * l_icloglock
2823 * IOERROR - give up hope all ye who enter here
2824 */
2825 if (iclog->ic_state == XLOG_STATE_WANT_SYNC ||
2826 iclog->ic_state & XLOG_STATE_SYNCING ||
2827 iclog->ic_state == XLOG_STATE_DONE_SYNC ||
2828 iclog->ic_state == XLOG_STATE_IOERROR )
2829 break;
2830 iclog = iclog->ic_next;
2831 } while (first_iclog != iclog);
2832}
2833#else
2834#define xlog_state_callback_check_state(l) ((void)0)
2835#endif
2836
2837STATIC void
2838xlog_state_do_callback(
2839 struct xlog *log,
2840 bool aborted,
2841 struct xlog_in_core *ciclog)
2842{
2843 struct xlog_in_core *iclog;
2844 struct xlog_in_core *first_iclog;
2845 bool did_callbacks = false;
2846 bool cycled_icloglock;
2847 bool ioerror;
2848 int flushcnt = 0;
2849 int repeats = 0;
2850
2851 spin_lock(&log->l_icloglock);
2852 do {
2853 /*
2854 * Scan all iclogs starting with the one pointed to by the
2855 * log. Reset this starting point each time the log is
2856 * unlocked (during callbacks).
2857 *
2858 * Keep looping through iclogs until one full pass is made
2859 * without running any callbacks.
2860 */
2861 first_iclog = log->l_iclog;
2862 iclog = log->l_iclog;
2863 cycled_icloglock = false;
2864 ioerror = false;
2865 repeats++;
2866
2867 do {
2868 if (xlog_state_iodone_process_iclog(log, iclog,
2869 ciclog, &ioerror))
2870 break;
2871
2872 if (!(iclog->ic_state &
2873 (XLOG_STATE_CALLBACK | XLOG_STATE_IOERROR))) {
2874 iclog = iclog->ic_next;
2875 continue;
2876 }
2877
2878 /*
2879 * Running callbacks will drop the icloglock which means
2880 * we'll have to run at least one more complete loop.
2881 */
2882 cycled_icloglock = true;
2883 xlog_state_do_iclog_callbacks(log, iclog, aborted);
2884
2885 xlog_state_clean_iclog(log, iclog);
2886 iclog = iclog->ic_next;
2887 } while (first_iclog != iclog);
2888
2889 did_callbacks |= cycled_icloglock;
2890
2891 if (repeats > 5000) {
2892 flushcnt += repeats;
2893 repeats = 0;
2894 xfs_warn(log->l_mp,
2895 "%s: possible infinite loop (%d iterations)",
2896 __func__, flushcnt);
2897 }
2898 } while (!ioerror && cycled_icloglock);
2899
2900 if (did_callbacks)
2901 xlog_state_callback_check_state(log);
2902
2903 if (log->l_iclog->ic_state & (XLOG_STATE_ACTIVE|XLOG_STATE_IOERROR))
2904 wake_up_all(&log->l_flush_wait);
2905
2906 spin_unlock(&log->l_icloglock);
2907}
2908
2909
2910/*
2911 * Finish transitioning this iclog to the dirty state.
2912 *
2913 * Make sure that we completely execute this routine only when this is
2914 * the last call to the iclog. There is a good chance that iclog flushes,
2915 * when we reach the end of the physical log, get turned into 2 separate
2916 * calls to bwrite. Hence, one iclog flush could generate two calls to this
2917 * routine. By using the reference count bwritecnt, we guarantee that only
2918 * the second completion goes through.
2919 *
2920 * Callbacks could take time, so they are done outside the scope of the
2921 * global state machine log lock.
2922 */
2923STATIC void
2924xlog_state_done_syncing(
2925 struct xlog_in_core *iclog,
2926 bool aborted)
2927{
2928 struct xlog *log = iclog->ic_log;
2929
2930 spin_lock(&log->l_icloglock);
2931
2932 ASSERT(iclog->ic_state == XLOG_STATE_SYNCING ||
2933 iclog->ic_state == XLOG_STATE_IOERROR);
2934 ASSERT(atomic_read(&iclog->ic_refcnt) == 0);
2935
2936 /*
2937 * If we got an error, either on the first buffer, or in the case of
2938 * split log writes, on the second, we mark ALL iclogs STATE_IOERROR,
2939 * and none should ever be attempted to be written to disk
2940 * again.
2941 */
2942 if (iclog->ic_state != XLOG_STATE_IOERROR)
2943 iclog->ic_state = XLOG_STATE_DONE_SYNC;
2944
2945 /*
2946 * Someone could be sleeping prior to writing out the next
2947 * iclog buffer, we wake them all, one will get to do the
2948 * I/O, the others get to wait for the result.
2949 */
2950 wake_up_all(&iclog->ic_write_wait);
2951 spin_unlock(&log->l_icloglock);
2952 xlog_state_do_callback(log, aborted, iclog); /* also cleans log */
2953} /* xlog_state_done_syncing */
2954
2955
2956/*
2957 * If the head of the in-core log ring is not (ACTIVE or DIRTY), then we must
2958 * sleep. We wait on the flush queue on the head iclog as that should be
2959 * the first iclog to complete flushing. Hence if all iclogs are syncing,
2960 * we will wait here and all new writes will sleep until a sync completes.
2961 *
2962 * The in-core logs are used in a circular fashion. They are not used
2963 * out-of-order even when an iclog past the head is free.
2964 *
2965 * return:
2966 * * log_offset where xlog_write() can start writing into the in-core
2967 * log's data space.
2968 * * in-core log pointer to which xlog_write() should write.
2969 * * boolean indicating this is a continued write to an in-core log.
2970 * If this is the last write, then the in-core log's offset field
2971 * needs to be incremented, depending on the amount of data which
2972 * is copied.
2973 */
2974STATIC int
2975xlog_state_get_iclog_space(
2976 struct xlog *log,
2977 int len,
2978 struct xlog_in_core **iclogp,
2979 struct xlog_ticket *ticket,
2980 int *continued_write,
2981 int *logoffsetp)
2982{
2983 int log_offset;
2984 xlog_rec_header_t *head;
2985 xlog_in_core_t *iclog;
2986 int error;
2987
2988restart:
2989 spin_lock(&log->l_icloglock);
2990 if (XLOG_FORCED_SHUTDOWN(log)) {
2991 spin_unlock(&log->l_icloglock);
2992 return -EIO;
2993 }
2994
2995 iclog = log->l_iclog;
2996 if (iclog->ic_state != XLOG_STATE_ACTIVE) {
2997 XFS_STATS_INC(log->l_mp, xs_log_noiclogs);
2998
2999 /* Wait for log writes to have flushed */
3000 xlog_wait(&log->l_flush_wait, &log->l_icloglock);
3001 goto restart;
3002 }
3003
3004 head = &iclog->ic_header;
3005
3006 atomic_inc(&iclog->ic_refcnt); /* prevents sync */
3007 log_offset = iclog->ic_offset;
3008
3009 /* On the 1st write to an iclog, figure out lsn. This works
3010 * if iclogs marked XLOG_STATE_WANT_SYNC always write out what they are
3011 * committing to. If the offset is set, that's how many blocks
3012 * must be written.
3013 */
3014 if (log_offset == 0) {
3015 ticket->t_curr_res -= log->l_iclog_hsize;
3016 xlog_tic_add_region(ticket,
3017 log->l_iclog_hsize,
3018 XLOG_REG_TYPE_LRHEADER);
3019 head->h_cycle = cpu_to_be32(log->l_curr_cycle);
3020 head->h_lsn = cpu_to_be64(
3021 xlog_assign_lsn(log->l_curr_cycle, log->l_curr_block));
3022 ASSERT(log->l_curr_block >= 0);
3023 }
3024
3025 /* If there is enough room to write everything, then do it. Otherwise,
3026 * claim the rest of the region and make sure the XLOG_STATE_WANT_SYNC
3027 * bit is on, so this will get flushed out. Don't update ic_offset
3028 * until you know exactly how many bytes get copied. Therefore, wait
3029 * until later to update ic_offset.
3030 *
3031 * xlog_write() algorithm assumes that at least 2 xlog_op_header_t's
3032 * can fit into remaining data section.
3033 */
3034 if (iclog->ic_size - iclog->ic_offset < 2*sizeof(xlog_op_header_t)) {
3035 xlog_state_switch_iclogs(log, iclog, iclog->ic_size);
3036
3037 /*
3038 * If I'm the only one writing to this iclog, sync it to disk.
3039 * We need to do an atomic compare and decrement here to avoid
3040 * racing with concurrent atomic_dec_and_lock() calls in
3041 * xlog_state_release_iclog() when there is more than one
3042 * reference to the iclog.
3043 */
3044 if (!atomic_add_unless(&iclog->ic_refcnt, -1, 1)) {
3045 /* we are the only one */
3046 spin_unlock(&log->l_icloglock);
3047 error = xlog_state_release_iclog(log, iclog);
3048 if (error)
3049 return error;
3050 } else {
3051 spin_unlock(&log->l_icloglock);
3052 }
3053 goto restart;
3054 }
3055
3056 /* Do we have enough room to write the full amount in the remainder
3057 * of this iclog? Or must we continue a write on the next iclog and
3058 * mark this iclog as completely taken? In the case where we switch
3059 * iclogs (to mark it taken), this particular iclog will release/sync
3060 * to disk in xlog_write().
3061 */
3062 if (len <= iclog->ic_size - iclog->ic_offset) {
3063 *continued_write = 0;
3064 iclog->ic_offset += len;
3065 } else {
3066 *continued_write = 1;
3067 xlog_state_switch_iclogs(log, iclog, iclog->ic_size);
3068 }
3069 *iclogp = iclog;
3070
3071 ASSERT(iclog->ic_offset <= iclog->ic_size);
3072 spin_unlock(&log->l_icloglock);
3073
3074 *logoffsetp = log_offset;
3075 return 0;
3076} /* xlog_state_get_iclog_space */
3077
3078/* The first cnt-1 times through here we don't need to
3079 * move the grant write head because the permanent
3080 * reservation has reserved cnt times the unit amount.
3081 * Release part of current permanent unit reservation and
3082 * reset current reservation to be one units worth. Also
3083 * move grant reservation head forward.
3084 */
3085STATIC void
3086xlog_regrant_reserve_log_space(
3087 struct xlog *log,
3088 struct xlog_ticket *ticket)
3089{
3090 trace_xfs_log_regrant_reserve_enter(log, ticket);
3091
3092 if (ticket->t_cnt > 0)
3093 ticket->t_cnt--;
3094
3095 xlog_grant_sub_space(log, &log->l_reserve_head.grant,
3096 ticket->t_curr_res);
3097 xlog_grant_sub_space(log, &log->l_write_head.grant,
3098 ticket->t_curr_res);
3099 ticket->t_curr_res = ticket->t_unit_res;
3100 xlog_tic_reset_res(ticket);
3101
3102 trace_xfs_log_regrant_reserve_sub(log, ticket);
3103
3104 /* just return if we still have some of the pre-reserved space */
3105 if (ticket->t_cnt > 0)
3106 return;
3107
3108 xlog_grant_add_space(log, &log->l_reserve_head.grant,
3109 ticket->t_unit_res);
3110
3111 trace_xfs_log_regrant_reserve_exit(log, ticket);
3112
3113 ticket->t_curr_res = ticket->t_unit_res;
3114 xlog_tic_reset_res(ticket);
3115} /* xlog_regrant_reserve_log_space */
3116
3117
3118/*
3119 * Give back the space left from a reservation.
3120 *
3121 * All the information we need to make a correct determination of space left
3122 * is present. For non-permanent reservations, things are quite easy. The
3123 * count should have been decremented to zero. We only need to deal with the
3124 * space remaining in the current reservation part of the ticket. If the
3125 * ticket contains a permanent reservation, there may be left over space which
3126 * needs to be released. A count of N means that N-1 refills of the current
3127 * reservation can be done before we need to ask for more space. The first
3128 * one goes to fill up the first current reservation. Once we run out of
3129 * space, the count will stay at zero and the only space remaining will be
3130 * in the current reservation field.
3131 */
3132STATIC void
3133xlog_ungrant_log_space(
3134 struct xlog *log,
3135 struct xlog_ticket *ticket)
3136{
3137 int bytes;
3138
3139 if (ticket->t_cnt > 0)
3140 ticket->t_cnt--;
3141
3142 trace_xfs_log_ungrant_enter(log, ticket);
3143 trace_xfs_log_ungrant_sub(log, ticket);
3144
3145 /*
3146 * If this is a permanent reservation ticket, we may be able to free
3147 * up more space based on the remaining count.
3148 */
3149 bytes = ticket->t_curr_res;
3150 if (ticket->t_cnt > 0) {
3151 ASSERT(ticket->t_flags & XLOG_TIC_PERM_RESERV);
3152 bytes += ticket->t_unit_res*ticket->t_cnt;
3153 }
3154
3155 xlog_grant_sub_space(log, &log->l_reserve_head.grant, bytes);
3156 xlog_grant_sub_space(log, &log->l_write_head.grant, bytes);
3157
3158 trace_xfs_log_ungrant_exit(log, ticket);
3159
3160 xfs_log_space_wake(log->l_mp);
3161}
3162
3163/*
3164 * Flush iclog to disk if this is the last reference to the given iclog and
3165 * the WANT_SYNC bit is set.
3166 *
3167 * When this function is entered, the iclog is not necessarily in the
3168 * WANT_SYNC state. It may be sitting around waiting to get filled.
3169 *
3170 *
3171 */
3172STATIC int
3173xlog_state_release_iclog(
3174 struct xlog *log,
3175 struct xlog_in_core *iclog)
3176{
3177 int sync = 0; /* do we sync? */
3178
3179 if (iclog->ic_state & XLOG_STATE_IOERROR)
3180 return -EIO;
3181
3182 ASSERT(atomic_read(&iclog->ic_refcnt) > 0);
3183 if (!atomic_dec_and_lock(&iclog->ic_refcnt, &log->l_icloglock))
3184 return 0;
3185
3186 if (iclog->ic_state & XLOG_STATE_IOERROR) {
3187 spin_unlock(&log->l_icloglock);
3188 return -EIO;
3189 }
3190 ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE ||
3191 iclog->ic_state == XLOG_STATE_WANT_SYNC);
3192
3193 if (iclog->ic_state == XLOG_STATE_WANT_SYNC) {
3194 /* update tail before writing to iclog */
3195 xfs_lsn_t tail_lsn = xlog_assign_tail_lsn(log->l_mp);
3196 sync++;
3197 iclog->ic_state = XLOG_STATE_SYNCING;
3198 iclog->ic_header.h_tail_lsn = cpu_to_be64(tail_lsn);
3199 xlog_verify_tail_lsn(log, iclog, tail_lsn);
3200 /* cycle incremented when incrementing curr_block */
3201 }
3202 spin_unlock(&log->l_icloglock);
3203
3204 /*
3205 * We let the log lock go, so it's possible that we hit a log I/O
3206 * error or some other SHUTDOWN condition that marks the iclog
3207 * as XLOG_STATE_IOERROR before the bwrite. However, we know that
3208 * this iclog has consistent data, so we ignore IOERROR
3209 * flags after this point.
3210 */
3211 if (sync)
3212 xlog_sync(log, iclog);
3213 return 0;
3214} /* xlog_state_release_iclog */
3215
3216
3217/*
3218 * This routine will mark the current iclog in the ring as WANT_SYNC
3219 * and move the current iclog pointer to the next iclog in the ring.
3220 * When this routine is called from xlog_state_get_iclog_space(), the
3221 * exact size of the iclog has not yet been determined. All we know is
3222 * that every data block. We have run out of space in this log record.
3223 */
3224STATIC void
3225xlog_state_switch_iclogs(
3226 struct xlog *log,
3227 struct xlog_in_core *iclog,
3228 int eventual_size)
3229{
3230 ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE);
3231 if (!eventual_size)
3232 eventual_size = iclog->ic_offset;
3233 iclog->ic_state = XLOG_STATE_WANT_SYNC;
3234 iclog->ic_header.h_prev_block = cpu_to_be32(log->l_prev_block);
3235 log->l_prev_block = log->l_curr_block;
3236 log->l_prev_cycle = log->l_curr_cycle;
3237
3238 /* roll log?: ic_offset changed later */
3239 log->l_curr_block += BTOBB(eventual_size)+BTOBB(log->l_iclog_hsize);
3240
3241 /* Round up to next log-sunit */
3242 if (xfs_sb_version_haslogv2(&log->l_mp->m_sb) &&
3243 log->l_mp->m_sb.sb_logsunit > 1) {
3244 uint32_t sunit_bb = BTOBB(log->l_mp->m_sb.sb_logsunit);
3245 log->l_curr_block = roundup(log->l_curr_block, sunit_bb);
3246 }
3247
3248 if (log->l_curr_block >= log->l_logBBsize) {
3249 /*
3250 * Rewind the current block before the cycle is bumped to make
3251 * sure that the combined LSN never transiently moves forward
3252 * when the log wraps to the next cycle. This is to support the
3253 * unlocked sample of these fields from xlog_valid_lsn(). Most
3254 * other cases should acquire l_icloglock.
3255 */
3256 log->l_curr_block -= log->l_logBBsize;
3257 ASSERT(log->l_curr_block >= 0);
3258 smp_wmb();
3259 log->l_curr_cycle++;
3260 if (log->l_curr_cycle == XLOG_HEADER_MAGIC_NUM)
3261 log->l_curr_cycle++;
3262 }
3263 ASSERT(iclog == log->l_iclog);
3264 log->l_iclog = iclog->ic_next;
3265} /* xlog_state_switch_iclogs */
3266
3267/*
3268 * Write out all data in the in-core log as of this exact moment in time.
3269 *
3270 * Data may be written to the in-core log during this call. However,
3271 * we don't guarantee this data will be written out. A change from past
3272 * implementation means this routine will *not* write out zero length LRs.
3273 *
3274 * Basically, we try and perform an intelligent scan of the in-core logs.
3275 * If we determine there is no flushable data, we just return. There is no
3276 * flushable data if:
3277 *
3278 * 1. the current iclog is active and has no data; the previous iclog
3279 * is in the active or dirty state.
3280 * 2. the current iclog is drity, and the previous iclog is in the
3281 * active or dirty state.
3282 *
3283 * We may sleep if:
3284 *
3285 * 1. the current iclog is not in the active nor dirty state.
3286 * 2. the current iclog dirty, and the previous iclog is not in the
3287 * active nor dirty state.
3288 * 3. the current iclog is active, and there is another thread writing
3289 * to this particular iclog.
3290 * 4. a) the current iclog is active and has no other writers
3291 * b) when we return from flushing out this iclog, it is still
3292 * not in the active nor dirty state.
3293 */
3294int
3295xfs_log_force(
3296 struct xfs_mount *mp,
3297 uint flags)
3298{
3299 struct xlog *log = mp->m_log;
3300 struct xlog_in_core *iclog;
3301 xfs_lsn_t lsn;
3302
3303 XFS_STATS_INC(mp, xs_log_force);
3304 trace_xfs_log_force(mp, 0, _RET_IP_);
3305
3306 xlog_cil_force(log);
3307
3308 spin_lock(&log->l_icloglock);
3309 iclog = log->l_iclog;
3310 if (iclog->ic_state & XLOG_STATE_IOERROR)
3311 goto out_error;
3312
3313 if (iclog->ic_state == XLOG_STATE_DIRTY ||
3314 (iclog->ic_state == XLOG_STATE_ACTIVE &&
3315 atomic_read(&iclog->ic_refcnt) == 0 && iclog->ic_offset == 0)) {
3316 /*
3317 * If the head is dirty or (active and empty), then we need to
3318 * look at the previous iclog.
3319 *
3320 * If the previous iclog is active or dirty we are done. There
3321 * is nothing to sync out. Otherwise, we attach ourselves to the
3322 * previous iclog and go to sleep.
3323 */
3324 iclog = iclog->ic_prev;
3325 if (iclog->ic_state == XLOG_STATE_ACTIVE ||
3326 iclog->ic_state == XLOG_STATE_DIRTY)
3327 goto out_unlock;
3328 } else if (iclog->ic_state == XLOG_STATE_ACTIVE) {
3329 if (atomic_read(&iclog->ic_refcnt) == 0) {
3330 /*
3331 * We are the only one with access to this iclog.
3332 *
3333 * Flush it out now. There should be a roundoff of zero
3334 * to show that someone has already taken care of the
3335 * roundoff from the previous sync.
3336 */
3337 atomic_inc(&iclog->ic_refcnt);
3338 lsn = be64_to_cpu(iclog->ic_header.h_lsn);
3339 xlog_state_switch_iclogs(log, iclog, 0);
3340 spin_unlock(&log->l_icloglock);
3341
3342 if (xlog_state_release_iclog(log, iclog))
3343 return -EIO;
3344
3345 spin_lock(&log->l_icloglock);
3346 if (be64_to_cpu(iclog->ic_header.h_lsn) != lsn ||
3347 iclog->ic_state == XLOG_STATE_DIRTY)
3348 goto out_unlock;
3349 } else {
3350 /*
3351 * Someone else is writing to this iclog.
3352 *
3353 * Use its call to flush out the data. However, the
3354 * other thread may not force out this LR, so we mark
3355 * it WANT_SYNC.
3356 */
3357 xlog_state_switch_iclogs(log, iclog, 0);
3358 }
3359 } else {
3360 /*
3361 * If the head iclog is not active nor dirty, we just attach
3362 * ourselves to the head and go to sleep if necessary.
3363 */
3364 ;
3365 }
3366
3367 if (!(flags & XFS_LOG_SYNC))
3368 goto out_unlock;
3369
3370 if (iclog->ic_state & XLOG_STATE_IOERROR)
3371 goto out_error;
3372 XFS_STATS_INC(mp, xs_log_force_sleep);
3373 xlog_wait(&iclog->ic_force_wait, &log->l_icloglock);
3374 if (iclog->ic_state & XLOG_STATE_IOERROR)
3375 return -EIO;
3376 return 0;
3377
3378out_unlock:
3379 spin_unlock(&log->l_icloglock);
3380 return 0;
3381out_error:
3382 spin_unlock(&log->l_icloglock);
3383 return -EIO;
3384}
3385
3386static int
3387__xfs_log_force_lsn(
3388 struct xfs_mount *mp,
3389 xfs_lsn_t lsn,
3390 uint flags,
3391 int *log_flushed,
3392 bool already_slept)
3393{
3394 struct xlog *log = mp->m_log;
3395 struct xlog_in_core *iclog;
3396
3397 spin_lock(&log->l_icloglock);
3398 iclog = log->l_iclog;
3399 if (iclog->ic_state & XLOG_STATE_IOERROR)
3400 goto out_error;
3401
3402 while (be64_to_cpu(iclog->ic_header.h_lsn) != lsn) {
3403 iclog = iclog->ic_next;
3404 if (iclog == log->l_iclog)
3405 goto out_unlock;
3406 }
3407
3408 if (iclog->ic_state == XLOG_STATE_DIRTY)
3409 goto out_unlock;
3410
3411 if (iclog->ic_state == XLOG_STATE_ACTIVE) {
3412 /*
3413 * We sleep here if we haven't already slept (e.g. this is the
3414 * first time we've looked at the correct iclog buf) and the
3415 * buffer before us is going to be sync'ed. The reason for this
3416 * is that if we are doing sync transactions here, by waiting
3417 * for the previous I/O to complete, we can allow a few more
3418 * transactions into this iclog before we close it down.
3419 *
3420 * Otherwise, we mark the buffer WANT_SYNC, and bump up the
3421 * refcnt so we can release the log (which drops the ref count).
3422 * The state switch keeps new transaction commits from using
3423 * this buffer. When the current commits finish writing into
3424 * the buffer, the refcount will drop to zero and the buffer
3425 * will go out then.
3426 */
3427 if (!already_slept &&
3428 (iclog->ic_prev->ic_state &
3429 (XLOG_STATE_WANT_SYNC | XLOG_STATE_SYNCING))) {
3430 ASSERT(!(iclog->ic_state & XLOG_STATE_IOERROR));
3431
3432 XFS_STATS_INC(mp, xs_log_force_sleep);
3433
3434 xlog_wait(&iclog->ic_prev->ic_write_wait,
3435 &log->l_icloglock);
3436 return -EAGAIN;
3437 }
3438 atomic_inc(&iclog->ic_refcnt);
3439 xlog_state_switch_iclogs(log, iclog, 0);
3440 spin_unlock(&log->l_icloglock);
3441 if (xlog_state_release_iclog(log, iclog))
3442 return -EIO;
3443 if (log_flushed)
3444 *log_flushed = 1;
3445 spin_lock(&log->l_icloglock);
3446 }
3447
3448 if (!(flags & XFS_LOG_SYNC) ||
3449 (iclog->ic_state & (XLOG_STATE_ACTIVE | XLOG_STATE_DIRTY)))
3450 goto out_unlock;
3451
3452 if (iclog->ic_state & XLOG_STATE_IOERROR)
3453 goto out_error;
3454
3455 XFS_STATS_INC(mp, xs_log_force_sleep);
3456 xlog_wait(&iclog->ic_force_wait, &log->l_icloglock);
3457 if (iclog->ic_state & XLOG_STATE_IOERROR)
3458 return -EIO;
3459 return 0;
3460
3461out_unlock:
3462 spin_unlock(&log->l_icloglock);
3463 return 0;
3464out_error:
3465 spin_unlock(&log->l_icloglock);
3466 return -EIO;
3467}
3468
3469/*
3470 * Force the in-core log to disk for a specific LSN.
3471 *
3472 * Find in-core log with lsn.
3473 * If it is in the DIRTY state, just return.
3474 * If it is in the ACTIVE state, move the in-core log into the WANT_SYNC
3475 * state and go to sleep or return.
3476 * If it is in any other state, go to sleep or return.
3477 *
3478 * Synchronous forces are implemented with a wait queue. All callers trying
3479 * to force a given lsn to disk must wait on the queue attached to the
3480 * specific in-core log. When given in-core log finally completes its write
3481 * to disk, that thread will wake up all threads waiting on the queue.
3482 */
3483int
3484xfs_log_force_lsn(
3485 struct xfs_mount *mp,
3486 xfs_lsn_t lsn,
3487 uint flags,
3488 int *log_flushed)
3489{
3490 int ret;
3491 ASSERT(lsn != 0);
3492
3493 XFS_STATS_INC(mp, xs_log_force);
3494 trace_xfs_log_force(mp, lsn, _RET_IP_);
3495
3496 lsn = xlog_cil_force_lsn(mp->m_log, lsn);
3497 if (lsn == NULLCOMMITLSN)
3498 return 0;
3499
3500 ret = __xfs_log_force_lsn(mp, lsn, flags, log_flushed, false);
3501 if (ret == -EAGAIN)
3502 ret = __xfs_log_force_lsn(mp, lsn, flags, log_flushed, true);
3503 return ret;
3504}
3505
3506/*
3507 * Called when we want to mark the current iclog as being ready to sync to
3508 * disk.
3509 */
3510STATIC void
3511xlog_state_want_sync(
3512 struct xlog *log,
3513 struct xlog_in_core *iclog)
3514{
3515 assert_spin_locked(&log->l_icloglock);
3516
3517 if (iclog->ic_state == XLOG_STATE_ACTIVE) {
3518 xlog_state_switch_iclogs(log, iclog, 0);
3519 } else {
3520 ASSERT(iclog->ic_state &
3521 (XLOG_STATE_WANT_SYNC|XLOG_STATE_IOERROR));
3522 }
3523}
3524
3525
3526/*****************************************************************************
3527 *
3528 * TICKET functions
3529 *
3530 *****************************************************************************
3531 */
3532
3533/*
3534 * Free a used ticket when its refcount falls to zero.
3535 */
3536void
3537xfs_log_ticket_put(
3538 xlog_ticket_t *ticket)
3539{
3540 ASSERT(atomic_read(&ticket->t_ref) > 0);
3541 if (atomic_dec_and_test(&ticket->t_ref))
3542 kmem_zone_free(xfs_log_ticket_zone, ticket);
3543}
3544
3545xlog_ticket_t *
3546xfs_log_ticket_get(
3547 xlog_ticket_t *ticket)
3548{
3549 ASSERT(atomic_read(&ticket->t_ref) > 0);
3550 atomic_inc(&ticket->t_ref);
3551 return ticket;
3552}
3553
3554/*
3555 * Figure out the total log space unit (in bytes) that would be
3556 * required for a log ticket.
3557 */
3558int
3559xfs_log_calc_unit_res(
3560 struct xfs_mount *mp,
3561 int unit_bytes)
3562{
3563 struct xlog *log = mp->m_log;
3564 int iclog_space;
3565 uint num_headers;
3566
3567 /*
3568 * Permanent reservations have up to 'cnt'-1 active log operations
3569 * in the log. A unit in this case is the amount of space for one
3570 * of these log operations. Normal reservations have a cnt of 1
3571 * and their unit amount is the total amount of space required.
3572 *
3573 * The following lines of code account for non-transaction data
3574 * which occupy space in the on-disk log.
3575 *
3576 * Normal form of a transaction is:
3577 * <oph><trans-hdr><start-oph><reg1-oph><reg1><reg2-oph>...<commit-oph>
3578 * and then there are LR hdrs, split-recs and roundoff at end of syncs.
3579 *
3580 * We need to account for all the leadup data and trailer data
3581 * around the transaction data.
3582 * And then we need to account for the worst case in terms of using
3583 * more space.
3584 * The worst case will happen if:
3585 * - the placement of the transaction happens to be such that the
3586 * roundoff is at its maximum
3587 * - the transaction data is synced before the commit record is synced
3588 * i.e. <transaction-data><roundoff> | <commit-rec><roundoff>
3589 * Therefore the commit record is in its own Log Record.
3590 * This can happen as the commit record is called with its
3591 * own region to xlog_write().
3592 * This then means that in the worst case, roundoff can happen for
3593 * the commit-rec as well.
3594 * The commit-rec is smaller than padding in this scenario and so it is
3595 * not added separately.
3596 */
3597
3598 /* for trans header */
3599 unit_bytes += sizeof(xlog_op_header_t);
3600 unit_bytes += sizeof(xfs_trans_header_t);
3601
3602 /* for start-rec */
3603 unit_bytes += sizeof(xlog_op_header_t);
3604
3605 /*
3606 * for LR headers - the space for data in an iclog is the size minus
3607 * the space used for the headers. If we use the iclog size, then we
3608 * undercalculate the number of headers required.
3609 *
3610 * Furthermore - the addition of op headers for split-recs might
3611 * increase the space required enough to require more log and op
3612 * headers, so take that into account too.
3613 *
3614 * IMPORTANT: This reservation makes the assumption that if this
3615 * transaction is the first in an iclog and hence has the LR headers
3616 * accounted to it, then the remaining space in the iclog is
3617 * exclusively for this transaction. i.e. if the transaction is larger
3618 * than the iclog, it will be the only thing in that iclog.
3619 * Fundamentally, this means we must pass the entire log vector to
3620 * xlog_write to guarantee this.
3621 */
3622 iclog_space = log->l_iclog_size - log->l_iclog_hsize;
3623 num_headers = howmany(unit_bytes, iclog_space);
3624
3625 /* for split-recs - ophdrs added when data split over LRs */
3626 unit_bytes += sizeof(xlog_op_header_t) * num_headers;
3627
3628 /* add extra header reservations if we overrun */
3629 while (!num_headers ||
3630 howmany(unit_bytes, iclog_space) > num_headers) {
3631 unit_bytes += sizeof(xlog_op_header_t);
3632 num_headers++;
3633 }
3634 unit_bytes += log->l_iclog_hsize * num_headers;
3635
3636 /* for commit-rec LR header - note: padding will subsume the ophdr */
3637 unit_bytes += log->l_iclog_hsize;
3638
3639 /* for roundoff padding for transaction data and one for commit record */
3640 if (xfs_sb_version_haslogv2(&mp->m_sb) && mp->m_sb.sb_logsunit > 1) {
3641 /* log su roundoff */
3642 unit_bytes += 2 * mp->m_sb.sb_logsunit;
3643 } else {
3644 /* BB roundoff */
3645 unit_bytes += 2 * BBSIZE;
3646 }
3647
3648 return unit_bytes;
3649}
3650
3651/*
3652 * Allocate and initialise a new log ticket.
3653 */
3654struct xlog_ticket *
3655xlog_ticket_alloc(
3656 struct xlog *log,
3657 int unit_bytes,
3658 int cnt,
3659 char client,
3660 bool permanent,
3661 xfs_km_flags_t alloc_flags)
3662{
3663 struct xlog_ticket *tic;
3664 int unit_res;
3665
3666 tic = kmem_zone_zalloc(xfs_log_ticket_zone, alloc_flags);
3667 if (!tic)
3668 return NULL;
3669
3670 unit_res = xfs_log_calc_unit_res(log->l_mp, unit_bytes);
3671
3672 atomic_set(&tic->t_ref, 1);
3673 tic->t_task = current;
3674 INIT_LIST_HEAD(&tic->t_queue);
3675 tic->t_unit_res = unit_res;
3676 tic->t_curr_res = unit_res;
3677 tic->t_cnt = cnt;
3678 tic->t_ocnt = cnt;
3679 tic->t_tid = prandom_u32();
3680 tic->t_clientid = client;
3681 tic->t_flags = XLOG_TIC_INITED;
3682 if (permanent)
3683 tic->t_flags |= XLOG_TIC_PERM_RESERV;
3684
3685 xlog_tic_reset_res(tic);
3686
3687 return tic;
3688}
3689
3690
3691/******************************************************************************
3692 *
3693 * Log debug routines
3694 *
3695 ******************************************************************************
3696 */
3697#if defined(DEBUG)
3698/*
3699 * Make sure that the destination ptr is within the valid data region of
3700 * one of the iclogs. This uses backup pointers stored in a different
3701 * part of the log in case we trash the log structure.
3702 */
3703STATIC void
3704xlog_verify_dest_ptr(
3705 struct xlog *log,
3706 void *ptr)
3707{
3708 int i;
3709 int good_ptr = 0;
3710
3711 for (i = 0; i < log->l_iclog_bufs; i++) {
3712 if (ptr >= log->l_iclog_bak[i] &&
3713 ptr <= log->l_iclog_bak[i] + log->l_iclog_size)
3714 good_ptr++;
3715 }
3716
3717 if (!good_ptr)
3718 xfs_emerg(log->l_mp, "%s: invalid ptr", __func__);
3719}
3720
3721/*
3722 * Check to make sure the grant write head didn't just over lap the tail. If
3723 * the cycles are the same, we can't be overlapping. Otherwise, make sure that
3724 * the cycles differ by exactly one and check the byte count.
3725 *
3726 * This check is run unlocked, so can give false positives. Rather than assert
3727 * on failures, use a warn-once flag and a panic tag to allow the admin to
3728 * determine if they want to panic the machine when such an error occurs. For
3729 * debug kernels this will have the same effect as using an assert but, unlinke
3730 * an assert, it can be turned off at runtime.
3731 */
3732STATIC void
3733xlog_verify_grant_tail(
3734 struct xlog *log)
3735{
3736 int tail_cycle, tail_blocks;
3737 int cycle, space;
3738
3739 xlog_crack_grant_head(&log->l_write_head.grant, &cycle, &space);
3740 xlog_crack_atomic_lsn(&log->l_tail_lsn, &tail_cycle, &tail_blocks);
3741 if (tail_cycle != cycle) {
3742 if (cycle - 1 != tail_cycle &&
3743 !(log->l_flags & XLOG_TAIL_WARN)) {
3744 xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES,
3745 "%s: cycle - 1 != tail_cycle", __func__);
3746 log->l_flags |= XLOG_TAIL_WARN;
3747 }
3748
3749 if (space > BBTOB(tail_blocks) &&
3750 !(log->l_flags & XLOG_TAIL_WARN)) {
3751 xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES,
3752 "%s: space > BBTOB(tail_blocks)", __func__);
3753 log->l_flags |= XLOG_TAIL_WARN;
3754 }
3755 }
3756}
3757
3758/* check if it will fit */
3759STATIC void
3760xlog_verify_tail_lsn(
3761 struct xlog *log,
3762 struct xlog_in_core *iclog,
3763 xfs_lsn_t tail_lsn)
3764{
3765 int blocks;
3766
3767 if (CYCLE_LSN(tail_lsn) == log->l_prev_cycle) {
3768 blocks =
3769 log->l_logBBsize - (log->l_prev_block - BLOCK_LSN(tail_lsn));
3770 if (blocks < BTOBB(iclog->ic_offset)+BTOBB(log->l_iclog_hsize))
3771 xfs_emerg(log->l_mp, "%s: ran out of log space", __func__);
3772 } else {
3773 ASSERT(CYCLE_LSN(tail_lsn)+1 == log->l_prev_cycle);
3774
3775 if (BLOCK_LSN(tail_lsn) == log->l_prev_block)
3776 xfs_emerg(log->l_mp, "%s: tail wrapped", __func__);
3777
3778 blocks = BLOCK_LSN(tail_lsn) - log->l_prev_block;
3779 if (blocks < BTOBB(iclog->ic_offset) + 1)
3780 xfs_emerg(log->l_mp, "%s: ran out of log space", __func__);
3781 }
3782} /* xlog_verify_tail_lsn */
3783
3784/*
3785 * Perform a number of checks on the iclog before writing to disk.
3786 *
3787 * 1. Make sure the iclogs are still circular
3788 * 2. Make sure we have a good magic number
3789 * 3. Make sure we don't have magic numbers in the data
3790 * 4. Check fields of each log operation header for:
3791 * A. Valid client identifier
3792 * B. tid ptr value falls in valid ptr space (user space code)
3793 * C. Length in log record header is correct according to the
3794 * individual operation headers within record.
3795 * 5. When a bwrite will occur within 5 blocks of the front of the physical
3796 * log, check the preceding blocks of the physical log to make sure all
3797 * the cycle numbers agree with the current cycle number.
3798 */
3799STATIC void
3800xlog_verify_iclog(
3801 struct xlog *log,
3802 struct xlog_in_core *iclog,
3803 int count)
3804{
3805 xlog_op_header_t *ophead;
3806 xlog_in_core_t *icptr;
3807 xlog_in_core_2_t *xhdr;
3808 void *base_ptr, *ptr, *p;
3809 ptrdiff_t field_offset;
3810 uint8_t clientid;
3811 int len, i, j, k, op_len;
3812 int idx;
3813
3814 /* check validity of iclog pointers */
3815 spin_lock(&log->l_icloglock);
3816 icptr = log->l_iclog;
3817 for (i = 0; i < log->l_iclog_bufs; i++, icptr = icptr->ic_next)
3818 ASSERT(icptr);
3819
3820 if (icptr != log->l_iclog)
3821 xfs_emerg(log->l_mp, "%s: corrupt iclog ring", __func__);
3822 spin_unlock(&log->l_icloglock);
3823
3824 /* check log magic numbers */
3825 if (iclog->ic_header.h_magicno != cpu_to_be32(XLOG_HEADER_MAGIC_NUM))
3826 xfs_emerg(log->l_mp, "%s: invalid magic num", __func__);
3827
3828 base_ptr = ptr = &iclog->ic_header;
3829 p = &iclog->ic_header;
3830 for (ptr += BBSIZE; ptr < base_ptr + count; ptr += BBSIZE) {
3831 if (*(__be32 *)ptr == cpu_to_be32(XLOG_HEADER_MAGIC_NUM))
3832 xfs_emerg(log->l_mp, "%s: unexpected magic num",
3833 __func__);
3834 }
3835
3836 /* check fields */
3837 len = be32_to_cpu(iclog->ic_header.h_num_logops);
3838 base_ptr = ptr = iclog->ic_datap;
3839 ophead = ptr;
3840 xhdr = iclog->ic_data;
3841 for (i = 0; i < len; i++) {
3842 ophead = ptr;
3843
3844 /* clientid is only 1 byte */
3845 p = &ophead->oh_clientid;
3846 field_offset = p - base_ptr;
3847 if (field_offset & 0x1ff) {
3848 clientid = ophead->oh_clientid;
3849 } else {
3850 idx = BTOBBT((char *)&ophead->oh_clientid - iclog->ic_datap);
3851 if (idx >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE)) {
3852 j = idx / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3853 k = idx % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3854 clientid = xlog_get_client_id(
3855 xhdr[j].hic_xheader.xh_cycle_data[k]);
3856 } else {
3857 clientid = xlog_get_client_id(
3858 iclog->ic_header.h_cycle_data[idx]);
3859 }
3860 }
3861 if (clientid != XFS_TRANSACTION && clientid != XFS_LOG)
3862 xfs_warn(log->l_mp,
3863 "%s: invalid clientid %d op "PTR_FMT" offset 0x%lx",
3864 __func__, clientid, ophead,
3865 (unsigned long)field_offset);
3866
3867 /* check length */
3868 p = &ophead->oh_len;
3869 field_offset = p - base_ptr;
3870 if (field_offset & 0x1ff) {
3871 op_len = be32_to_cpu(ophead->oh_len);
3872 } else {
3873 idx = BTOBBT((uintptr_t)&ophead->oh_len -
3874 (uintptr_t)iclog->ic_datap);
3875 if (idx >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE)) {
3876 j = idx / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3877 k = idx % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3878 op_len = be32_to_cpu(xhdr[j].hic_xheader.xh_cycle_data[k]);
3879 } else {
3880 op_len = be32_to_cpu(iclog->ic_header.h_cycle_data[idx]);
3881 }
3882 }
3883 ptr += sizeof(xlog_op_header_t) + op_len;
3884 }
3885} /* xlog_verify_iclog */
3886#endif
3887
3888/*
3889 * Mark all iclogs IOERROR. l_icloglock is held by the caller.
3890 */
3891STATIC int
3892xlog_state_ioerror(
3893 struct xlog *log)
3894{
3895 xlog_in_core_t *iclog, *ic;
3896
3897 iclog = log->l_iclog;
3898 if (! (iclog->ic_state & XLOG_STATE_IOERROR)) {
3899 /*
3900 * Mark all the incore logs IOERROR.
3901 * From now on, no log flushes will result.
3902 */
3903 ic = iclog;
3904 do {
3905 ic->ic_state = XLOG_STATE_IOERROR;
3906 ic = ic->ic_next;
3907 } while (ic != iclog);
3908 return 0;
3909 }
3910 /*
3911 * Return non-zero, if state transition has already happened.
3912 */
3913 return 1;
3914}
3915
3916/*
3917 * This is called from xfs_force_shutdown, when we're forcibly
3918 * shutting down the filesystem, typically because of an IO error.
3919 * Our main objectives here are to make sure that:
3920 * a. if !logerror, flush the logs to disk. Anything modified
3921 * after this is ignored.
3922 * b. the filesystem gets marked 'SHUTDOWN' for all interested
3923 * parties to find out, 'atomically'.
3924 * c. those who're sleeping on log reservations, pinned objects and
3925 * other resources get woken up, and be told the bad news.
3926 * d. nothing new gets queued up after (b) and (c) are done.
3927 *
3928 * Note: for the !logerror case we need to flush the regions held in memory out
3929 * to disk first. This needs to be done before the log is marked as shutdown,
3930 * otherwise the iclog writes will fail.
3931 */
3932int
3933xfs_log_force_umount(
3934 struct xfs_mount *mp,
3935 int logerror)
3936{
3937 struct xlog *log;
3938 int retval;
3939
3940 log = mp->m_log;
3941
3942 /*
3943 * If this happens during log recovery, don't worry about
3944 * locking; the log isn't open for business yet.
3945 */
3946 if (!log ||
3947 log->l_flags & XLOG_ACTIVE_RECOVERY) {
3948 mp->m_flags |= XFS_MOUNT_FS_SHUTDOWN;
3949 if (mp->m_sb_bp)
3950 mp->m_sb_bp->b_flags |= XBF_DONE;
3951 return 0;
3952 }
3953
3954 /*
3955 * Somebody could've already done the hard work for us.
3956 * No need to get locks for this.
3957 */
3958 if (logerror && log->l_iclog->ic_state & XLOG_STATE_IOERROR) {
3959 ASSERT(XLOG_FORCED_SHUTDOWN(log));
3960 return 1;
3961 }
3962
3963 /*
3964 * Flush all the completed transactions to disk before marking the log
3965 * being shut down. We need to do it in this order to ensure that
3966 * completed operations are safely on disk before we shut down, and that
3967 * we don't have to issue any buffer IO after the shutdown flags are set
3968 * to guarantee this.
3969 */
3970 if (!logerror)
3971 xfs_log_force(mp, XFS_LOG_SYNC);
3972
3973 /*
3974 * mark the filesystem and the as in a shutdown state and wake
3975 * everybody up to tell them the bad news.
3976 */
3977 spin_lock(&log->l_icloglock);
3978 mp->m_flags |= XFS_MOUNT_FS_SHUTDOWN;
3979 if (mp->m_sb_bp)
3980 mp->m_sb_bp->b_flags |= XBF_DONE;
3981
3982 /*
3983 * Mark the log and the iclogs with IO error flags to prevent any
3984 * further log IO from being issued or completed.
3985 */
3986 log->l_flags |= XLOG_IO_ERROR;
3987 retval = xlog_state_ioerror(log);
3988 spin_unlock(&log->l_icloglock);
3989
3990 /*
3991 * We don't want anybody waiting for log reservations after this. That
3992 * means we have to wake up everybody queued up on reserveq as well as
3993 * writeq. In addition, we make sure in xlog_{re}grant_log_space that
3994 * we don't enqueue anything once the SHUTDOWN flag is set, and this
3995 * action is protected by the grant locks.
3996 */
3997 xlog_grant_head_wake_all(&log->l_reserve_head);
3998 xlog_grant_head_wake_all(&log->l_write_head);
3999
4000 /*
4001 * Wake up everybody waiting on xfs_log_force. Wake the CIL push first
4002 * as if the log writes were completed. The abort handling in the log
4003 * item committed callback functions will do this again under lock to
4004 * avoid races.
4005 */
4006 spin_lock(&log->l_cilp->xc_push_lock);
4007 wake_up_all(&log->l_cilp->xc_commit_wait);
4008 spin_unlock(&log->l_cilp->xc_push_lock);
4009 xlog_state_do_callback(log, true, NULL);
4010
4011#ifdef XFSERRORDEBUG
4012 {
4013 xlog_in_core_t *iclog;
4014
4015 spin_lock(&log->l_icloglock);
4016 iclog = log->l_iclog;
4017 do {
4018 ASSERT(iclog->ic_callback == 0);
4019 iclog = iclog->ic_next;
4020 } while (iclog != log->l_iclog);
4021 spin_unlock(&log->l_icloglock);
4022 }
4023#endif
4024 /* return non-zero if log IOERROR transition had already happened */
4025 return retval;
4026}
4027
4028STATIC int
4029xlog_iclogs_empty(
4030 struct xlog *log)
4031{
4032 xlog_in_core_t *iclog;
4033
4034 iclog = log->l_iclog;
4035 do {
4036 /* endianness does not matter here, zero is zero in
4037 * any language.
4038 */
4039 if (iclog->ic_header.h_num_logops)
4040 return 0;
4041 iclog = iclog->ic_next;
4042 } while (iclog != log->l_iclog);
4043 return 1;
4044}
4045
4046/*
4047 * Verify that an LSN stamped into a piece of metadata is valid. This is
4048 * intended for use in read verifiers on v5 superblocks.
4049 */
4050bool
4051xfs_log_check_lsn(
4052 struct xfs_mount *mp,
4053 xfs_lsn_t lsn)
4054{
4055 struct xlog *log = mp->m_log;
4056 bool valid;
4057
4058 /*
4059 * norecovery mode skips mount-time log processing and unconditionally
4060 * resets the in-core LSN. We can't validate in this mode, but
4061 * modifications are not allowed anyways so just return true.
4062 */
4063 if (mp->m_flags & XFS_MOUNT_NORECOVERY)
4064 return true;
4065
4066 /*
4067 * Some metadata LSNs are initialized to NULL (e.g., the agfl). This is
4068 * handled by recovery and thus safe to ignore here.
4069 */
4070 if (lsn == NULLCOMMITLSN)
4071 return true;
4072
4073 valid = xlog_valid_lsn(mp->m_log, lsn);
4074
4075 /* warn the user about what's gone wrong before verifier failure */
4076 if (!valid) {
4077 spin_lock(&log->l_icloglock);
4078 xfs_warn(mp,
4079"Corruption warning: Metadata has LSN (%d:%d) ahead of current LSN (%d:%d). "
4080"Please unmount and run xfs_repair (>= v4.3) to resolve.",
4081 CYCLE_LSN(lsn), BLOCK_LSN(lsn),
4082 log->l_curr_cycle, log->l_curr_block);
4083 spin_unlock(&log->l_icloglock);
4084 }
4085
4086 return valid;
4087}
4088
4089bool
4090xfs_log_in_recovery(
4091 struct xfs_mount *mp)
4092{
4093 struct xlog *log = mp->m_log;
4094
4095 return log->l_flags & XLOG_ACTIVE_RECOVERY;
4096}