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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/*
2 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18#include "xfs.h"
19#include "xfs_fs.h"
20#include "xfs_shared.h"
21#include "xfs_format.h"
22#include "xfs_log_format.h"
23#include "xfs_trans_resv.h"
24#include "xfs_mount.h"
25#include "xfs_errortag.h"
26#include "xfs_error.h"
27#include "xfs_trans.h"
28#include "xfs_trans_priv.h"
29#include "xfs_log.h"
30#include "xfs_log_priv.h"
31#include "xfs_log_recover.h"
32#include "xfs_inode.h"
33#include "xfs_trace.h"
34#include "xfs_fsops.h"
35#include "xfs_cksum.h"
36#include "xfs_sysfs.h"
37#include "xfs_sb.h"
38
39kmem_zone_t *xfs_log_ticket_zone;
40
41/* Local miscellaneous function prototypes */
42STATIC int
43xlog_commit_record(
44 struct xlog *log,
45 struct xlog_ticket *ticket,
46 struct xlog_in_core **iclog,
47 xfs_lsn_t *commitlsnp);
48
49STATIC struct xlog *
50xlog_alloc_log(
51 struct xfs_mount *mp,
52 struct xfs_buftarg *log_target,
53 xfs_daddr_t blk_offset,
54 int num_bblks);
55STATIC int
56xlog_space_left(
57 struct xlog *log,
58 atomic64_t *head);
59STATIC int
60xlog_sync(
61 struct xlog *log,
62 struct xlog_in_core *iclog);
63STATIC void
64xlog_dealloc_log(
65 struct xlog *log);
66
67/* local state machine functions */
68STATIC void xlog_state_done_syncing(xlog_in_core_t *iclog, int);
69STATIC void
70xlog_state_do_callback(
71 struct xlog *log,
72 int aborted,
73 struct xlog_in_core *iclog);
74STATIC int
75xlog_state_get_iclog_space(
76 struct xlog *log,
77 int len,
78 struct xlog_in_core **iclog,
79 struct xlog_ticket *ticket,
80 int *continued_write,
81 int *logoffsetp);
82STATIC int
83xlog_state_release_iclog(
84 struct xlog *log,
85 struct xlog_in_core *iclog);
86STATIC void
87xlog_state_switch_iclogs(
88 struct xlog *log,
89 struct xlog_in_core *iclog,
90 int eventual_size);
91STATIC void
92xlog_state_want_sync(
93 struct xlog *log,
94 struct xlog_in_core *iclog);
95
96STATIC void
97xlog_grant_push_ail(
98 struct xlog *log,
99 int need_bytes);
100STATIC void
101xlog_regrant_reserve_log_space(
102 struct xlog *log,
103 struct xlog_ticket *ticket);
104STATIC void
105xlog_ungrant_log_space(
106 struct xlog *log,
107 struct xlog_ticket *ticket);
108
109#if defined(DEBUG)
110STATIC void
111xlog_verify_dest_ptr(
112 struct xlog *log,
113 void *ptr);
114STATIC void
115xlog_verify_grant_tail(
116 struct xlog *log);
117STATIC void
118xlog_verify_iclog(
119 struct xlog *log,
120 struct xlog_in_core *iclog,
121 int count,
122 bool syncing);
123STATIC void
124xlog_verify_tail_lsn(
125 struct xlog *log,
126 struct xlog_in_core *iclog,
127 xfs_lsn_t tail_lsn);
128#else
129#define xlog_verify_dest_ptr(a,b)
130#define xlog_verify_grant_tail(a)
131#define xlog_verify_iclog(a,b,c,d)
132#define xlog_verify_tail_lsn(a,b,c)
133#endif
134
135STATIC int
136xlog_iclogs_empty(
137 struct xlog *log);
138
139static void
140xlog_grant_sub_space(
141 struct xlog *log,
142 atomic64_t *head,
143 int bytes)
144{
145 int64_t head_val = atomic64_read(head);
146 int64_t new, old;
147
148 do {
149 int cycle, space;
150
151 xlog_crack_grant_head_val(head_val, &cycle, &space);
152
153 space -= bytes;
154 if (space < 0) {
155 space += log->l_logsize;
156 cycle--;
157 }
158
159 old = head_val;
160 new = xlog_assign_grant_head_val(cycle, space);
161 head_val = atomic64_cmpxchg(head, old, new);
162 } while (head_val != old);
163}
164
165static void
166xlog_grant_add_space(
167 struct xlog *log,
168 atomic64_t *head,
169 int bytes)
170{
171 int64_t head_val = atomic64_read(head);
172 int64_t new, old;
173
174 do {
175 int tmp;
176 int cycle, space;
177
178 xlog_crack_grant_head_val(head_val, &cycle, &space);
179
180 tmp = log->l_logsize - space;
181 if (tmp > bytes)
182 space += bytes;
183 else {
184 space = bytes - tmp;
185 cycle++;
186 }
187
188 old = head_val;
189 new = xlog_assign_grant_head_val(cycle, space);
190 head_val = atomic64_cmpxchg(head, old, new);
191 } while (head_val != old);
192}
193
194STATIC void
195xlog_grant_head_init(
196 struct xlog_grant_head *head)
197{
198 xlog_assign_grant_head(&head->grant, 1, 0);
199 INIT_LIST_HEAD(&head->waiters);
200 spin_lock_init(&head->lock);
201}
202
203STATIC void
204xlog_grant_head_wake_all(
205 struct xlog_grant_head *head)
206{
207 struct xlog_ticket *tic;
208
209 spin_lock(&head->lock);
210 list_for_each_entry(tic, &head->waiters, t_queue)
211 wake_up_process(tic->t_task);
212 spin_unlock(&head->lock);
213}
214
215static inline int
216xlog_ticket_reservation(
217 struct xlog *log,
218 struct xlog_grant_head *head,
219 struct xlog_ticket *tic)
220{
221 if (head == &log->l_write_head) {
222 ASSERT(tic->t_flags & XLOG_TIC_PERM_RESERV);
223 return tic->t_unit_res;
224 } else {
225 if (tic->t_flags & XLOG_TIC_PERM_RESERV)
226 return tic->t_unit_res * tic->t_cnt;
227 else
228 return tic->t_unit_res;
229 }
230}
231
232STATIC bool
233xlog_grant_head_wake(
234 struct xlog *log,
235 struct xlog_grant_head *head,
236 int *free_bytes)
237{
238 struct xlog_ticket *tic;
239 int need_bytes;
240
241 list_for_each_entry(tic, &head->waiters, t_queue) {
242 need_bytes = xlog_ticket_reservation(log, head, tic);
243 if (*free_bytes < need_bytes)
244 return false;
245
246 *free_bytes -= need_bytes;
247 trace_xfs_log_grant_wake_up(log, tic);
248 wake_up_process(tic->t_task);
249 }
250
251 return true;
252}
253
254STATIC int
255xlog_grant_head_wait(
256 struct xlog *log,
257 struct xlog_grant_head *head,
258 struct xlog_ticket *tic,
259 int need_bytes) __releases(&head->lock)
260 __acquires(&head->lock)
261{
262 list_add_tail(&tic->t_queue, &head->waiters);
263
264 do {
265 if (XLOG_FORCED_SHUTDOWN(log))
266 goto shutdown;
267 xlog_grant_push_ail(log, need_bytes);
268
269 __set_current_state(TASK_UNINTERRUPTIBLE);
270 spin_unlock(&head->lock);
271
272 XFS_STATS_INC(log->l_mp, xs_sleep_logspace);
273
274 trace_xfs_log_grant_sleep(log, tic);
275 schedule();
276 trace_xfs_log_grant_wake(log, tic);
277
278 spin_lock(&head->lock);
279 if (XLOG_FORCED_SHUTDOWN(log))
280 goto shutdown;
281 } while (xlog_space_left(log, &head->grant) < need_bytes);
282
283 list_del_init(&tic->t_queue);
284 return 0;
285shutdown:
286 list_del_init(&tic->t_queue);
287 return -EIO;
288}
289
290/*
291 * Atomically get the log space required for a log ticket.
292 *
293 * Once a ticket gets put onto head->waiters, it will only return after the
294 * needed reservation is satisfied.
295 *
296 * This function is structured so that it has a lock free fast path. This is
297 * necessary because every new transaction reservation will come through this
298 * path. Hence any lock will be globally hot if we take it unconditionally on
299 * every pass.
300 *
301 * As tickets are only ever moved on and off head->waiters under head->lock, we
302 * only need to take that lock if we are going to add the ticket to the queue
303 * and sleep. We can avoid taking the lock if the ticket was never added to
304 * head->waiters because the t_queue list head will be empty and we hold the
305 * only reference to it so it can safely be checked unlocked.
306 */
307STATIC int
308xlog_grant_head_check(
309 struct xlog *log,
310 struct xlog_grant_head *head,
311 struct xlog_ticket *tic,
312 int *need_bytes)
313{
314 int free_bytes;
315 int error = 0;
316
317 ASSERT(!(log->l_flags & XLOG_ACTIVE_RECOVERY));
318
319 /*
320 * If there are other waiters on the queue then give them a chance at
321 * logspace before us. Wake up the first waiters, if we do not wake
322 * up all the waiters then go to sleep waiting for more free space,
323 * otherwise try to get some space for this transaction.
324 */
325 *need_bytes = xlog_ticket_reservation(log, head, tic);
326 free_bytes = xlog_space_left(log, &head->grant);
327 if (!list_empty_careful(&head->waiters)) {
328 spin_lock(&head->lock);
329 if (!xlog_grant_head_wake(log, head, &free_bytes) ||
330 free_bytes < *need_bytes) {
331 error = xlog_grant_head_wait(log, head, tic,
332 *need_bytes);
333 }
334 spin_unlock(&head->lock);
335 } else if (free_bytes < *need_bytes) {
336 spin_lock(&head->lock);
337 error = xlog_grant_head_wait(log, head, tic, *need_bytes);
338 spin_unlock(&head->lock);
339 }
340
341 return error;
342}
343
344static void
345xlog_tic_reset_res(xlog_ticket_t *tic)
346{
347 tic->t_res_num = 0;
348 tic->t_res_arr_sum = 0;
349 tic->t_res_num_ophdrs = 0;
350}
351
352static void
353xlog_tic_add_region(xlog_ticket_t *tic, uint len, uint type)
354{
355 if (tic->t_res_num == XLOG_TIC_LEN_MAX) {
356 /* add to overflow and start again */
357 tic->t_res_o_flow += tic->t_res_arr_sum;
358 tic->t_res_num = 0;
359 tic->t_res_arr_sum = 0;
360 }
361
362 tic->t_res_arr[tic->t_res_num].r_len = len;
363 tic->t_res_arr[tic->t_res_num].r_type = type;
364 tic->t_res_arr_sum += len;
365 tic->t_res_num++;
366}
367
368/*
369 * Replenish the byte reservation required by moving the grant write head.
370 */
371int
372xfs_log_regrant(
373 struct xfs_mount *mp,
374 struct xlog_ticket *tic)
375{
376 struct xlog *log = mp->m_log;
377 int need_bytes;
378 int error = 0;
379
380 if (XLOG_FORCED_SHUTDOWN(log))
381 return -EIO;
382
383 XFS_STATS_INC(mp, xs_try_logspace);
384
385 /*
386 * This is a new transaction on the ticket, so we need to change the
387 * transaction ID so that the next transaction has a different TID in
388 * the log. Just add one to the existing tid so that we can see chains
389 * of rolling transactions in the log easily.
390 */
391 tic->t_tid++;
392
393 xlog_grant_push_ail(log, tic->t_unit_res);
394
395 tic->t_curr_res = tic->t_unit_res;
396 xlog_tic_reset_res(tic);
397
398 if (tic->t_cnt > 0)
399 return 0;
400
401 trace_xfs_log_regrant(log, tic);
402
403 error = xlog_grant_head_check(log, &log->l_write_head, tic,
404 &need_bytes);
405 if (error)
406 goto out_error;
407
408 xlog_grant_add_space(log, &log->l_write_head.grant, need_bytes);
409 trace_xfs_log_regrant_exit(log, tic);
410 xlog_verify_grant_tail(log);
411 return 0;
412
413out_error:
414 /*
415 * If we are failing, make sure the ticket doesn't have any current
416 * reservations. We don't want to add this back when the ticket/
417 * transaction gets cancelled.
418 */
419 tic->t_curr_res = 0;
420 tic->t_cnt = 0; /* ungrant will give back unit_res * t_cnt. */
421 return error;
422}
423
424/*
425 * Reserve log space and return a ticket corresponding the reservation.
426 *
427 * Each reservation is going to reserve extra space for a log record header.
428 * When writes happen to the on-disk log, we don't subtract the length of the
429 * log record header from any reservation. By wasting space in each
430 * reservation, we prevent over allocation problems.
431 */
432int
433xfs_log_reserve(
434 struct xfs_mount *mp,
435 int unit_bytes,
436 int cnt,
437 struct xlog_ticket **ticp,
438 uint8_t client,
439 bool permanent)
440{
441 struct xlog *log = mp->m_log;
442 struct xlog_ticket *tic;
443 int need_bytes;
444 int error = 0;
445
446 ASSERT(client == XFS_TRANSACTION || client == XFS_LOG);
447
448 if (XLOG_FORCED_SHUTDOWN(log))
449 return -EIO;
450
451 XFS_STATS_INC(mp, xs_try_logspace);
452
453 ASSERT(*ticp == NULL);
454 tic = xlog_ticket_alloc(log, unit_bytes, cnt, client, permanent,
455 KM_SLEEP | KM_MAYFAIL);
456 if (!tic)
457 return -ENOMEM;
458
459 *ticp = tic;
460
461 xlog_grant_push_ail(log, tic->t_cnt ? tic->t_unit_res * tic->t_cnt
462 : tic->t_unit_res);
463
464 trace_xfs_log_reserve(log, tic);
465
466 error = xlog_grant_head_check(log, &log->l_reserve_head, tic,
467 &need_bytes);
468 if (error)
469 goto out_error;
470
471 xlog_grant_add_space(log, &log->l_reserve_head.grant, need_bytes);
472 xlog_grant_add_space(log, &log->l_write_head.grant, need_bytes);
473 trace_xfs_log_reserve_exit(log, tic);
474 xlog_verify_grant_tail(log);
475 return 0;
476
477out_error:
478 /*
479 * If we are failing, make sure the ticket doesn't have any current
480 * reservations. We don't want to add this back when the ticket/
481 * transaction gets cancelled.
482 */
483 tic->t_curr_res = 0;
484 tic->t_cnt = 0; /* ungrant will give back unit_res * t_cnt. */
485 return error;
486}
487
488
489/*
490 * NOTES:
491 *
492 * 1. currblock field gets updated at startup and after in-core logs
493 * marked as with WANT_SYNC.
494 */
495
496/*
497 * This routine is called when a user of a log manager ticket is done with
498 * the reservation. If the ticket was ever used, then a commit record for
499 * the associated transaction is written out as a log operation header with
500 * no data. The flag XLOG_TIC_INITED is set when the first write occurs with
501 * a given ticket. If the ticket was one with a permanent reservation, then
502 * a few operations are done differently. Permanent reservation tickets by
503 * default don't release the reservation. They just commit the current
504 * transaction with the belief that the reservation is still needed. A flag
505 * must be passed in before permanent reservations are actually released.
506 * When these type of tickets are not released, they need to be set into
507 * the inited state again. By doing this, a start record will be written
508 * out when the next write occurs.
509 */
510xfs_lsn_t
511xfs_log_done(
512 struct xfs_mount *mp,
513 struct xlog_ticket *ticket,
514 struct xlog_in_core **iclog,
515 bool regrant)
516{
517 struct xlog *log = mp->m_log;
518 xfs_lsn_t lsn = 0;
519
520 if (XLOG_FORCED_SHUTDOWN(log) ||
521 /*
522 * If nothing was ever written, don't write out commit record.
523 * If we get an error, just continue and give back the log ticket.
524 */
525 (((ticket->t_flags & XLOG_TIC_INITED) == 0) &&
526 (xlog_commit_record(log, ticket, iclog, &lsn)))) {
527 lsn = (xfs_lsn_t) -1;
528 regrant = false;
529 }
530
531
532 if (!regrant) {
533 trace_xfs_log_done_nonperm(log, ticket);
534
535 /*
536 * Release ticket if not permanent reservation or a specific
537 * request has been made to release a permanent reservation.
538 */
539 xlog_ungrant_log_space(log, ticket);
540 } else {
541 trace_xfs_log_done_perm(log, ticket);
542
543 xlog_regrant_reserve_log_space(log, ticket);
544 /* If this ticket was a permanent reservation and we aren't
545 * trying to release it, reset the inited flags; so next time
546 * we write, a start record will be written out.
547 */
548 ticket->t_flags |= XLOG_TIC_INITED;
549 }
550
551 xfs_log_ticket_put(ticket);
552 return lsn;
553}
554
555/*
556 * Attaches a new iclog I/O completion callback routine during
557 * transaction commit. If the log is in error state, a non-zero
558 * return code is handed back and the caller is responsible for
559 * executing the callback at an appropriate time.
560 */
561int
562xfs_log_notify(
563 struct xlog_in_core *iclog,
564 xfs_log_callback_t *cb)
565{
566 int abortflg;
567
568 spin_lock(&iclog->ic_callback_lock);
569 abortflg = (iclog->ic_state & XLOG_STATE_IOERROR);
570 if (!abortflg) {
571 ASSERT_ALWAYS((iclog->ic_state == XLOG_STATE_ACTIVE) ||
572 (iclog->ic_state == XLOG_STATE_WANT_SYNC));
573 cb->cb_next = NULL;
574 *(iclog->ic_callback_tail) = cb;
575 iclog->ic_callback_tail = &(cb->cb_next);
576 }
577 spin_unlock(&iclog->ic_callback_lock);
578 return abortflg;
579}
580
581int
582xfs_log_release_iclog(
583 struct xfs_mount *mp,
584 struct xlog_in_core *iclog)
585{
586 if (xlog_state_release_iclog(mp->m_log, iclog)) {
587 xfs_force_shutdown(mp, SHUTDOWN_LOG_IO_ERROR);
588 return -EIO;
589 }
590
591 return 0;
592}
593
594/*
595 * Mount a log filesystem
596 *
597 * mp - ubiquitous xfs mount point structure
598 * log_target - buftarg of on-disk log device
599 * blk_offset - Start block # where block size is 512 bytes (BBSIZE)
600 * num_bblocks - Number of BBSIZE blocks in on-disk log
601 *
602 * Return error or zero.
603 */
604int
605xfs_log_mount(
606 xfs_mount_t *mp,
607 xfs_buftarg_t *log_target,
608 xfs_daddr_t blk_offset,
609 int num_bblks)
610{
611 bool fatal = xfs_sb_version_hascrc(&mp->m_sb);
612 int error = 0;
613 int min_logfsbs;
614
615 if (!(mp->m_flags & XFS_MOUNT_NORECOVERY)) {
616 xfs_notice(mp, "Mounting V%d Filesystem",
617 XFS_SB_VERSION_NUM(&mp->m_sb));
618 } else {
619 xfs_notice(mp,
620"Mounting V%d filesystem in no-recovery mode. Filesystem will be inconsistent.",
621 XFS_SB_VERSION_NUM(&mp->m_sb));
622 ASSERT(mp->m_flags & XFS_MOUNT_RDONLY);
623 }
624
625 mp->m_log = xlog_alloc_log(mp, log_target, blk_offset, num_bblks);
626 if (IS_ERR(mp->m_log)) {
627 error = PTR_ERR(mp->m_log);
628 goto out;
629 }
630
631 /*
632 * Validate the given log space and drop a critical message via syslog
633 * if the log size is too small that would lead to some unexpected
634 * situations in transaction log space reservation stage.
635 *
636 * Note: we can't just reject the mount if the validation fails. This
637 * would mean that people would have to downgrade their kernel just to
638 * remedy the situation as there is no way to grow the log (short of
639 * black magic surgery with xfs_db).
640 *
641 * We can, however, reject mounts for CRC format filesystems, as the
642 * mkfs binary being used to make the filesystem should never create a
643 * filesystem with a log that is too small.
644 */
645 min_logfsbs = xfs_log_calc_minimum_size(mp);
646
647 if (mp->m_sb.sb_logblocks < min_logfsbs) {
648 xfs_warn(mp,
649 "Log size %d blocks too small, minimum size is %d blocks",
650 mp->m_sb.sb_logblocks, min_logfsbs);
651 error = -EINVAL;
652 } else if (mp->m_sb.sb_logblocks > XFS_MAX_LOG_BLOCKS) {
653 xfs_warn(mp,
654 "Log size %d blocks too large, maximum size is %lld blocks",
655 mp->m_sb.sb_logblocks, XFS_MAX_LOG_BLOCKS);
656 error = -EINVAL;
657 } else if (XFS_FSB_TO_B(mp, mp->m_sb.sb_logblocks) > XFS_MAX_LOG_BYTES) {
658 xfs_warn(mp,
659 "log size %lld bytes too large, maximum size is %lld bytes",
660 XFS_FSB_TO_B(mp, mp->m_sb.sb_logblocks),
661 XFS_MAX_LOG_BYTES);
662 error = -EINVAL;
663 } else if (mp->m_sb.sb_logsunit > 1 &&
664 mp->m_sb.sb_logsunit % mp->m_sb.sb_blocksize) {
665 xfs_warn(mp,
666 "log stripe unit %u bytes must be a multiple of block size",
667 mp->m_sb.sb_logsunit);
668 error = -EINVAL;
669 fatal = true;
670 }
671 if (error) {
672 /*
673 * Log check errors are always fatal on v5; or whenever bad
674 * metadata leads to a crash.
675 */
676 if (fatal) {
677 xfs_crit(mp, "AAIEEE! Log failed size checks. Abort!");
678 ASSERT(0);
679 goto out_free_log;
680 }
681 xfs_crit(mp, "Log size out of supported range.");
682 xfs_crit(mp,
683"Continuing onwards, but if log hangs are experienced then please report this message in the bug report.");
684 }
685
686 /*
687 * Initialize the AIL now we have a log.
688 */
689 error = xfs_trans_ail_init(mp);
690 if (error) {
691 xfs_warn(mp, "AIL initialisation failed: error %d", error);
692 goto out_free_log;
693 }
694 mp->m_log->l_ailp = mp->m_ail;
695
696 /*
697 * skip log recovery on a norecovery mount. pretend it all
698 * just worked.
699 */
700 if (!(mp->m_flags & XFS_MOUNT_NORECOVERY)) {
701 int readonly = (mp->m_flags & XFS_MOUNT_RDONLY);
702
703 if (readonly)
704 mp->m_flags &= ~XFS_MOUNT_RDONLY;
705
706 error = xlog_recover(mp->m_log);
707
708 if (readonly)
709 mp->m_flags |= XFS_MOUNT_RDONLY;
710 if (error) {
711 xfs_warn(mp, "log mount/recovery failed: error %d",
712 error);
713 xlog_recover_cancel(mp->m_log);
714 goto out_destroy_ail;
715 }
716 }
717
718 error = xfs_sysfs_init(&mp->m_log->l_kobj, &xfs_log_ktype, &mp->m_kobj,
719 "log");
720 if (error)
721 goto out_destroy_ail;
722
723 /* Normal transactions can now occur */
724 mp->m_log->l_flags &= ~XLOG_ACTIVE_RECOVERY;
725
726 /*
727 * Now the log has been fully initialised and we know were our
728 * space grant counters are, we can initialise the permanent ticket
729 * needed for delayed logging to work.
730 */
731 xlog_cil_init_post_recovery(mp->m_log);
732
733 return 0;
734
735out_destroy_ail:
736 xfs_trans_ail_destroy(mp);
737out_free_log:
738 xlog_dealloc_log(mp->m_log);
739out:
740 return error;
741}
742
743/*
744 * Finish the recovery of the file system. This is separate from the
745 * xfs_log_mount() call, because it depends on the code in xfs_mountfs() to read
746 * in the root and real-time bitmap inodes between calling xfs_log_mount() and
747 * here.
748 *
749 * If we finish recovery successfully, start the background log work. If we are
750 * not doing recovery, then we have a RO filesystem and we don't need to start
751 * it.
752 */
753int
754xfs_log_mount_finish(
755 struct xfs_mount *mp)
756{
757 int error = 0;
758 bool readonly = (mp->m_flags & XFS_MOUNT_RDONLY);
759 bool recovered = mp->m_log->l_flags & XLOG_RECOVERY_NEEDED;
760
761 if (mp->m_flags & XFS_MOUNT_NORECOVERY) {
762 ASSERT(mp->m_flags & XFS_MOUNT_RDONLY);
763 return 0;
764 } else if (readonly) {
765 /* Allow unlinked processing to proceed */
766 mp->m_flags &= ~XFS_MOUNT_RDONLY;
767 }
768
769 /*
770 * During the second phase of log recovery, we need iget and
771 * iput to behave like they do for an active filesystem.
772 * xfs_fs_drop_inode needs to be able to prevent the deletion
773 * of inodes before we're done replaying log items on those
774 * inodes. Turn it off immediately after recovery finishes
775 * so that we don't leak the quota inodes if subsequent mount
776 * activities fail.
777 *
778 * We let all inodes involved in redo item processing end up on
779 * the LRU instead of being evicted immediately so that if we do
780 * something to an unlinked inode, the irele won't cause
781 * premature truncation and freeing of the inode, which results
782 * in log recovery failure. We have to evict the unreferenced
783 * lru inodes after clearing SB_ACTIVE because we don't
784 * otherwise clean up the lru if there's a subsequent failure in
785 * xfs_mountfs, which leads to us leaking the inodes if nothing
786 * else (e.g. quotacheck) references the inodes before the
787 * mount failure occurs.
788 */
789 mp->m_super->s_flags |= SB_ACTIVE;
790 error = xlog_recover_finish(mp->m_log);
791 if (!error)
792 xfs_log_work_queue(mp);
793 mp->m_super->s_flags &= ~SB_ACTIVE;
794 evict_inodes(mp->m_super);
795
796 /*
797 * Drain the buffer LRU after log recovery. This is required for v4
798 * filesystems to avoid leaving around buffers with NULL verifier ops,
799 * but we do it unconditionally to make sure we're always in a clean
800 * cache state after mount.
801 *
802 * Don't push in the error case because the AIL may have pending intents
803 * that aren't removed until recovery is cancelled.
804 */
805 if (!error && recovered) {
806 xfs_log_force(mp, XFS_LOG_SYNC);
807 xfs_ail_push_all_sync(mp->m_ail);
808 }
809 xfs_wait_buftarg(mp->m_ddev_targp);
810
811 if (readonly)
812 mp->m_flags |= XFS_MOUNT_RDONLY;
813
814 return error;
815}
816
817/*
818 * The mount has failed. Cancel the recovery if it hasn't completed and destroy
819 * the log.
820 */
821int
822xfs_log_mount_cancel(
823 struct xfs_mount *mp)
824{
825 int error;
826
827 error = xlog_recover_cancel(mp->m_log);
828 xfs_log_unmount(mp);
829
830 return error;
831}
832
833/*
834 * Final log writes as part of unmount.
835 *
836 * Mark the filesystem clean as unmount happens. Note that during relocation
837 * this routine needs to be executed as part of source-bag while the
838 * deallocation must not be done until source-end.
839 */
840
841/*
842 * Unmount record used to have a string "Unmount filesystem--" in the
843 * data section where the "Un" was really a magic number (XLOG_UNMOUNT_TYPE).
844 * We just write the magic number now since that particular field isn't
845 * currently architecture converted and "Unmount" is a bit foo.
846 * As far as I know, there weren't any dependencies on the old behaviour.
847 */
848
849static int
850xfs_log_unmount_write(xfs_mount_t *mp)
851{
852 struct xlog *log = mp->m_log;
853 xlog_in_core_t *iclog;
854#ifdef DEBUG
855 xlog_in_core_t *first_iclog;
856#endif
857 xlog_ticket_t *tic = NULL;
858 xfs_lsn_t lsn;
859 int error;
860
861 /*
862 * Don't write out unmount record on norecovery mounts or ro devices.
863 * Or, if we are doing a forced umount (typically because of IO errors).
864 */
865 if (mp->m_flags & XFS_MOUNT_NORECOVERY ||
866 xfs_readonly_buftarg(log->l_mp->m_logdev_targp)) {
867 ASSERT(mp->m_flags & XFS_MOUNT_RDONLY);
868 return 0;
869 }
870
871 error = xfs_log_force(mp, XFS_LOG_SYNC);
872 ASSERT(error || !(XLOG_FORCED_SHUTDOWN(log)));
873
874#ifdef DEBUG
875 first_iclog = iclog = log->l_iclog;
876 do {
877 if (!(iclog->ic_state & XLOG_STATE_IOERROR)) {
878 ASSERT(iclog->ic_state & XLOG_STATE_ACTIVE);
879 ASSERT(iclog->ic_offset == 0);
880 }
881 iclog = iclog->ic_next;
882 } while (iclog != first_iclog);
883#endif
884 if (! (XLOG_FORCED_SHUTDOWN(log))) {
885 error = xfs_log_reserve(mp, 600, 1, &tic, XFS_LOG, 0);
886 if (!error) {
887 /* the data section must be 32 bit size aligned */
888 struct {
889 uint16_t magic;
890 uint16_t pad1;
891 uint32_t pad2; /* may as well make it 64 bits */
892 } magic = {
893 .magic = XLOG_UNMOUNT_TYPE,
894 };
895 struct xfs_log_iovec reg = {
896 .i_addr = &magic,
897 .i_len = sizeof(magic),
898 .i_type = XLOG_REG_TYPE_UNMOUNT,
899 };
900 struct xfs_log_vec vec = {
901 .lv_niovecs = 1,
902 .lv_iovecp = ®,
903 };
904
905 /* remove inited flag, and account for space used */
906 tic->t_flags = 0;
907 tic->t_curr_res -= sizeof(magic);
908 error = xlog_write(log, &vec, tic, &lsn,
909 NULL, XLOG_UNMOUNT_TRANS);
910 /*
911 * At this point, we're umounting anyway,
912 * so there's no point in transitioning log state
913 * to IOERROR. Just continue...
914 */
915 }
916
917 if (error)
918 xfs_alert(mp, "%s: unmount record failed", __func__);
919
920
921 spin_lock(&log->l_icloglock);
922 iclog = log->l_iclog;
923 atomic_inc(&iclog->ic_refcnt);
924 xlog_state_want_sync(log, iclog);
925 spin_unlock(&log->l_icloglock);
926 error = xlog_state_release_iclog(log, iclog);
927
928 spin_lock(&log->l_icloglock);
929 if (!(iclog->ic_state == XLOG_STATE_ACTIVE ||
930 iclog->ic_state == XLOG_STATE_DIRTY)) {
931 if (!XLOG_FORCED_SHUTDOWN(log)) {
932 xlog_wait(&iclog->ic_force_wait,
933 &log->l_icloglock);
934 } else {
935 spin_unlock(&log->l_icloglock);
936 }
937 } else {
938 spin_unlock(&log->l_icloglock);
939 }
940 if (tic) {
941 trace_xfs_log_umount_write(log, tic);
942 xlog_ungrant_log_space(log, tic);
943 xfs_log_ticket_put(tic);
944 }
945 } else {
946 /*
947 * We're already in forced_shutdown mode, couldn't
948 * even attempt to write out the unmount transaction.
949 *
950 * Go through the motions of sync'ing and releasing
951 * the iclog, even though no I/O will actually happen,
952 * we need to wait for other log I/Os that may already
953 * be in progress. Do this as a separate section of
954 * code so we'll know if we ever get stuck here that
955 * we're in this odd situation of trying to unmount
956 * a file system that went into forced_shutdown as
957 * the result of an unmount..
958 */
959 spin_lock(&log->l_icloglock);
960 iclog = log->l_iclog;
961 atomic_inc(&iclog->ic_refcnt);
962
963 xlog_state_want_sync(log, iclog);
964 spin_unlock(&log->l_icloglock);
965 error = xlog_state_release_iclog(log, iclog);
966
967 spin_lock(&log->l_icloglock);
968
969 if ( ! ( iclog->ic_state == XLOG_STATE_ACTIVE
970 || iclog->ic_state == XLOG_STATE_DIRTY
971 || iclog->ic_state == XLOG_STATE_IOERROR) ) {
972
973 xlog_wait(&iclog->ic_force_wait,
974 &log->l_icloglock);
975 } else {
976 spin_unlock(&log->l_icloglock);
977 }
978 }
979
980 return error;
981} /* xfs_log_unmount_write */
982
983/*
984 * Empty the log for unmount/freeze.
985 *
986 * To do this, we first need to shut down the background log work so it is not
987 * trying to cover the log as we clean up. We then need to unpin all objects in
988 * the log so we can then flush them out. Once they have completed their IO and
989 * run the callbacks removing themselves from the AIL, we can write the unmount
990 * record.
991 */
992void
993xfs_log_quiesce(
994 struct xfs_mount *mp)
995{
996 cancel_delayed_work_sync(&mp->m_log->l_work);
997 xfs_log_force(mp, XFS_LOG_SYNC);
998
999 /*
1000 * The superblock buffer is uncached and while xfs_ail_push_all_sync()
1001 * will push it, xfs_wait_buftarg() will not wait for it. Further,
1002 * xfs_buf_iowait() cannot be used because it was pushed with the
1003 * XBF_ASYNC flag set, so we need to use a lock/unlock pair to wait for
1004 * the IO to complete.
1005 */
1006 xfs_ail_push_all_sync(mp->m_ail);
1007 xfs_wait_buftarg(mp->m_ddev_targp);
1008 xfs_buf_lock(mp->m_sb_bp);
1009 xfs_buf_unlock(mp->m_sb_bp);
1010
1011 xfs_log_unmount_write(mp);
1012}
1013
1014/*
1015 * Shut down and release the AIL and Log.
1016 *
1017 * During unmount, we need to ensure we flush all the dirty metadata objects
1018 * from the AIL so that the log is empty before we write the unmount record to
1019 * the log. Once this is done, we can tear down the AIL and the log.
1020 */
1021void
1022xfs_log_unmount(
1023 struct xfs_mount *mp)
1024{
1025 xfs_log_quiesce(mp);
1026
1027 xfs_trans_ail_destroy(mp);
1028
1029 xfs_sysfs_del(&mp->m_log->l_kobj);
1030
1031 xlog_dealloc_log(mp->m_log);
1032}
1033
1034void
1035xfs_log_item_init(
1036 struct xfs_mount *mp,
1037 struct xfs_log_item *item,
1038 int type,
1039 const struct xfs_item_ops *ops)
1040{
1041 item->li_mountp = mp;
1042 item->li_ailp = mp->m_ail;
1043 item->li_type = type;
1044 item->li_ops = ops;
1045 item->li_lv = NULL;
1046
1047 INIT_LIST_HEAD(&item->li_ail);
1048 INIT_LIST_HEAD(&item->li_cil);
1049 INIT_LIST_HEAD(&item->li_bio_list);
1050}
1051
1052/*
1053 * Wake up processes waiting for log space after we have moved the log tail.
1054 */
1055void
1056xfs_log_space_wake(
1057 struct xfs_mount *mp)
1058{
1059 struct xlog *log = mp->m_log;
1060 int free_bytes;
1061
1062 if (XLOG_FORCED_SHUTDOWN(log))
1063 return;
1064
1065 if (!list_empty_careful(&log->l_write_head.waiters)) {
1066 ASSERT(!(log->l_flags & XLOG_ACTIVE_RECOVERY));
1067
1068 spin_lock(&log->l_write_head.lock);
1069 free_bytes = xlog_space_left(log, &log->l_write_head.grant);
1070 xlog_grant_head_wake(log, &log->l_write_head, &free_bytes);
1071 spin_unlock(&log->l_write_head.lock);
1072 }
1073
1074 if (!list_empty_careful(&log->l_reserve_head.waiters)) {
1075 ASSERT(!(log->l_flags & XLOG_ACTIVE_RECOVERY));
1076
1077 spin_lock(&log->l_reserve_head.lock);
1078 free_bytes = xlog_space_left(log, &log->l_reserve_head.grant);
1079 xlog_grant_head_wake(log, &log->l_reserve_head, &free_bytes);
1080 spin_unlock(&log->l_reserve_head.lock);
1081 }
1082}
1083
1084/*
1085 * Determine if we have a transaction that has gone to disk that needs to be
1086 * covered. To begin the transition to the idle state firstly the log needs to
1087 * be idle. That means the CIL, the AIL and the iclogs needs to be empty before
1088 * we start attempting to cover the log.
1089 *
1090 * Only if we are then in a state where covering is needed, the caller is
1091 * informed that dummy transactions are required to move the log into the idle
1092 * state.
1093 *
1094 * If there are any items in the AIl or CIL, then we do not want to attempt to
1095 * cover the log as we may be in a situation where there isn't log space
1096 * available to run a dummy transaction and this can lead to deadlocks when the
1097 * tail of the log is pinned by an item that is modified in the CIL. Hence
1098 * there's no point in running a dummy transaction at this point because we
1099 * can't start trying to idle the log until both the CIL and AIL are empty.
1100 */
1101static int
1102xfs_log_need_covered(xfs_mount_t *mp)
1103{
1104 struct xlog *log = mp->m_log;
1105 int needed = 0;
1106
1107 if (!xfs_fs_writable(mp, SB_FREEZE_WRITE))
1108 return 0;
1109
1110 if (!xlog_cil_empty(log))
1111 return 0;
1112
1113 spin_lock(&log->l_icloglock);
1114 switch (log->l_covered_state) {
1115 case XLOG_STATE_COVER_DONE:
1116 case XLOG_STATE_COVER_DONE2:
1117 case XLOG_STATE_COVER_IDLE:
1118 break;
1119 case XLOG_STATE_COVER_NEED:
1120 case XLOG_STATE_COVER_NEED2:
1121 if (xfs_ail_min_lsn(log->l_ailp))
1122 break;
1123 if (!xlog_iclogs_empty(log))
1124 break;
1125
1126 needed = 1;
1127 if (log->l_covered_state == XLOG_STATE_COVER_NEED)
1128 log->l_covered_state = XLOG_STATE_COVER_DONE;
1129 else
1130 log->l_covered_state = XLOG_STATE_COVER_DONE2;
1131 break;
1132 default:
1133 needed = 1;
1134 break;
1135 }
1136 spin_unlock(&log->l_icloglock);
1137 return needed;
1138}
1139
1140/*
1141 * We may be holding the log iclog lock upon entering this routine.
1142 */
1143xfs_lsn_t
1144xlog_assign_tail_lsn_locked(
1145 struct xfs_mount *mp)
1146{
1147 struct xlog *log = mp->m_log;
1148 struct xfs_log_item *lip;
1149 xfs_lsn_t tail_lsn;
1150
1151 assert_spin_locked(&mp->m_ail->ail_lock);
1152
1153 /*
1154 * To make sure we always have a valid LSN for the log tail we keep
1155 * track of the last LSN which was committed in log->l_last_sync_lsn,
1156 * and use that when the AIL was empty.
1157 */
1158 lip = xfs_ail_min(mp->m_ail);
1159 if (lip)
1160 tail_lsn = lip->li_lsn;
1161 else
1162 tail_lsn = atomic64_read(&log->l_last_sync_lsn);
1163 trace_xfs_log_assign_tail_lsn(log, tail_lsn);
1164 atomic64_set(&log->l_tail_lsn, tail_lsn);
1165 return tail_lsn;
1166}
1167
1168xfs_lsn_t
1169xlog_assign_tail_lsn(
1170 struct xfs_mount *mp)
1171{
1172 xfs_lsn_t tail_lsn;
1173
1174 spin_lock(&mp->m_ail->ail_lock);
1175 tail_lsn = xlog_assign_tail_lsn_locked(mp);
1176 spin_unlock(&mp->m_ail->ail_lock);
1177
1178 return tail_lsn;
1179}
1180
1181/*
1182 * Return the space in the log between the tail and the head. The head
1183 * is passed in the cycle/bytes formal parms. In the special case where
1184 * the reserve head has wrapped passed the tail, this calculation is no
1185 * longer valid. In this case, just return 0 which means there is no space
1186 * in the log. This works for all places where this function is called
1187 * with the reserve head. Of course, if the write head were to ever
1188 * wrap the tail, we should blow up. Rather than catch this case here,
1189 * we depend on other ASSERTions in other parts of the code. XXXmiken
1190 *
1191 * This code also handles the case where the reservation head is behind
1192 * the tail. The details of this case are described below, but the end
1193 * result is that we return the size of the log as the amount of space left.
1194 */
1195STATIC int
1196xlog_space_left(
1197 struct xlog *log,
1198 atomic64_t *head)
1199{
1200 int free_bytes;
1201 int tail_bytes;
1202 int tail_cycle;
1203 int head_cycle;
1204 int head_bytes;
1205
1206 xlog_crack_grant_head(head, &head_cycle, &head_bytes);
1207 xlog_crack_atomic_lsn(&log->l_tail_lsn, &tail_cycle, &tail_bytes);
1208 tail_bytes = BBTOB(tail_bytes);
1209 if (tail_cycle == head_cycle && head_bytes >= tail_bytes)
1210 free_bytes = log->l_logsize - (head_bytes - tail_bytes);
1211 else if (tail_cycle + 1 < head_cycle)
1212 return 0;
1213 else if (tail_cycle < head_cycle) {
1214 ASSERT(tail_cycle == (head_cycle - 1));
1215 free_bytes = tail_bytes - head_bytes;
1216 } else {
1217 /*
1218 * The reservation head is behind the tail.
1219 * In this case we just want to return the size of the
1220 * log as the amount of space left.
1221 */
1222 xfs_alert(log->l_mp, "xlog_space_left: head behind tail");
1223 xfs_alert(log->l_mp,
1224 " tail_cycle = %d, tail_bytes = %d",
1225 tail_cycle, tail_bytes);
1226 xfs_alert(log->l_mp,
1227 " GH cycle = %d, GH bytes = %d",
1228 head_cycle, head_bytes);
1229 ASSERT(0);
1230 free_bytes = log->l_logsize;
1231 }
1232 return free_bytes;
1233}
1234
1235
1236/*
1237 * Log function which is called when an io completes.
1238 *
1239 * The log manager needs its own routine, in order to control what
1240 * happens with the buffer after the write completes.
1241 */
1242static void
1243xlog_iodone(xfs_buf_t *bp)
1244{
1245 struct xlog_in_core *iclog = bp->b_log_item;
1246 struct xlog *l = iclog->ic_log;
1247 int aborted = 0;
1248
1249 /*
1250 * Race to shutdown the filesystem if we see an error or the iclog is in
1251 * IOABORT state. The IOABORT state is only set in DEBUG mode to inject
1252 * CRC errors into log recovery.
1253 */
1254 if (XFS_TEST_ERROR(bp->b_error, l->l_mp, XFS_ERRTAG_IODONE_IOERR) ||
1255 iclog->ic_state & XLOG_STATE_IOABORT) {
1256 if (iclog->ic_state & XLOG_STATE_IOABORT)
1257 iclog->ic_state &= ~XLOG_STATE_IOABORT;
1258
1259 xfs_buf_ioerror_alert(bp, __func__);
1260 xfs_buf_stale(bp);
1261 xfs_force_shutdown(l->l_mp, SHUTDOWN_LOG_IO_ERROR);
1262 /*
1263 * This flag will be propagated to the trans-committed
1264 * callback routines to let them know that the log-commit
1265 * didn't succeed.
1266 */
1267 aborted = XFS_LI_ABORTED;
1268 } else if (iclog->ic_state & XLOG_STATE_IOERROR) {
1269 aborted = XFS_LI_ABORTED;
1270 }
1271
1272 /* log I/O is always issued ASYNC */
1273 ASSERT(bp->b_flags & XBF_ASYNC);
1274 xlog_state_done_syncing(iclog, aborted);
1275
1276 /*
1277 * drop the buffer lock now that we are done. Nothing references
1278 * the buffer after this, so an unmount waiting on this lock can now
1279 * tear it down safely. As such, it is unsafe to reference the buffer
1280 * (bp) after the unlock as we could race with it being freed.
1281 */
1282 xfs_buf_unlock(bp);
1283}
1284
1285/*
1286 * Return size of each in-core log record buffer.
1287 *
1288 * All machines get 8 x 32kB buffers by default, unless tuned otherwise.
1289 *
1290 * If the filesystem blocksize is too large, we may need to choose a
1291 * larger size since the directory code currently logs entire blocks.
1292 */
1293
1294STATIC void
1295xlog_get_iclog_buffer_size(
1296 struct xfs_mount *mp,
1297 struct xlog *log)
1298{
1299 int size;
1300 int xhdrs;
1301
1302 if (mp->m_logbufs <= 0)
1303 log->l_iclog_bufs = XLOG_MAX_ICLOGS;
1304 else
1305 log->l_iclog_bufs = mp->m_logbufs;
1306
1307 /*
1308 * Buffer size passed in from mount system call.
1309 */
1310 if (mp->m_logbsize > 0) {
1311 size = log->l_iclog_size = mp->m_logbsize;
1312 log->l_iclog_size_log = 0;
1313 while (size != 1) {
1314 log->l_iclog_size_log++;
1315 size >>= 1;
1316 }
1317
1318 if (xfs_sb_version_haslogv2(&mp->m_sb)) {
1319 /* # headers = size / 32k
1320 * one header holds cycles from 32k of data
1321 */
1322
1323 xhdrs = mp->m_logbsize / XLOG_HEADER_CYCLE_SIZE;
1324 if (mp->m_logbsize % XLOG_HEADER_CYCLE_SIZE)
1325 xhdrs++;
1326 log->l_iclog_hsize = xhdrs << BBSHIFT;
1327 log->l_iclog_heads = xhdrs;
1328 } else {
1329 ASSERT(mp->m_logbsize <= XLOG_BIG_RECORD_BSIZE);
1330 log->l_iclog_hsize = BBSIZE;
1331 log->l_iclog_heads = 1;
1332 }
1333 goto done;
1334 }
1335
1336 /* All machines use 32kB buffers by default. */
1337 log->l_iclog_size = XLOG_BIG_RECORD_BSIZE;
1338 log->l_iclog_size_log = XLOG_BIG_RECORD_BSHIFT;
1339
1340 /* the default log size is 16k or 32k which is one header sector */
1341 log->l_iclog_hsize = BBSIZE;
1342 log->l_iclog_heads = 1;
1343
1344done:
1345 /* are we being asked to make the sizes selected above visible? */
1346 if (mp->m_logbufs == 0)
1347 mp->m_logbufs = log->l_iclog_bufs;
1348 if (mp->m_logbsize == 0)
1349 mp->m_logbsize = log->l_iclog_size;
1350} /* xlog_get_iclog_buffer_size */
1351
1352
1353void
1354xfs_log_work_queue(
1355 struct xfs_mount *mp)
1356{
1357 queue_delayed_work(mp->m_sync_workqueue, &mp->m_log->l_work,
1358 msecs_to_jiffies(xfs_syncd_centisecs * 10));
1359}
1360
1361/*
1362 * Every sync period we need to unpin all items in the AIL and push them to
1363 * disk. If there is nothing dirty, then we might need to cover the log to
1364 * indicate that the filesystem is idle.
1365 */
1366static void
1367xfs_log_worker(
1368 struct work_struct *work)
1369{
1370 struct xlog *log = container_of(to_delayed_work(work),
1371 struct xlog, l_work);
1372 struct xfs_mount *mp = log->l_mp;
1373
1374 /* dgc: errors ignored - not fatal and nowhere to report them */
1375 if (xfs_log_need_covered(mp)) {
1376 /*
1377 * Dump a transaction into the log that contains no real change.
1378 * This is needed to stamp the current tail LSN into the log
1379 * during the covering operation.
1380 *
1381 * We cannot use an inode here for this - that will push dirty
1382 * state back up into the VFS and then periodic inode flushing
1383 * will prevent log covering from making progress. Hence we
1384 * synchronously log the superblock instead to ensure the
1385 * superblock is immediately unpinned and can be written back.
1386 */
1387 xfs_sync_sb(mp, true);
1388 } else
1389 xfs_log_force(mp, 0);
1390
1391 /* start pushing all the metadata that is currently dirty */
1392 xfs_ail_push_all(mp->m_ail);
1393
1394 /* queue us up again */
1395 xfs_log_work_queue(mp);
1396}
1397
1398/*
1399 * This routine initializes some of the log structure for a given mount point.
1400 * Its primary purpose is to fill in enough, so recovery can occur. However,
1401 * some other stuff may be filled in too.
1402 */
1403STATIC struct xlog *
1404xlog_alloc_log(
1405 struct xfs_mount *mp,
1406 struct xfs_buftarg *log_target,
1407 xfs_daddr_t blk_offset,
1408 int num_bblks)
1409{
1410 struct xlog *log;
1411 xlog_rec_header_t *head;
1412 xlog_in_core_t **iclogp;
1413 xlog_in_core_t *iclog, *prev_iclog=NULL;
1414 xfs_buf_t *bp;
1415 int i;
1416 int error = -ENOMEM;
1417 uint log2_size = 0;
1418
1419 log = kmem_zalloc(sizeof(struct xlog), KM_MAYFAIL);
1420 if (!log) {
1421 xfs_warn(mp, "Log allocation failed: No memory!");
1422 goto out;
1423 }
1424
1425 log->l_mp = mp;
1426 log->l_targ = log_target;
1427 log->l_logsize = BBTOB(num_bblks);
1428 log->l_logBBstart = blk_offset;
1429 log->l_logBBsize = num_bblks;
1430 log->l_covered_state = XLOG_STATE_COVER_IDLE;
1431 log->l_flags |= XLOG_ACTIVE_RECOVERY;
1432 INIT_DELAYED_WORK(&log->l_work, xfs_log_worker);
1433
1434 log->l_prev_block = -1;
1435 /* log->l_tail_lsn = 0x100000000LL; cycle = 1; current block = 0 */
1436 xlog_assign_atomic_lsn(&log->l_tail_lsn, 1, 0);
1437 xlog_assign_atomic_lsn(&log->l_last_sync_lsn, 1, 0);
1438 log->l_curr_cycle = 1; /* 0 is bad since this is initial value */
1439
1440 xlog_grant_head_init(&log->l_reserve_head);
1441 xlog_grant_head_init(&log->l_write_head);
1442
1443 error = -EFSCORRUPTED;
1444 if (xfs_sb_version_hassector(&mp->m_sb)) {
1445 log2_size = mp->m_sb.sb_logsectlog;
1446 if (log2_size < BBSHIFT) {
1447 xfs_warn(mp, "Log sector size too small (0x%x < 0x%x)",
1448 log2_size, BBSHIFT);
1449 goto out_free_log;
1450 }
1451
1452 log2_size -= BBSHIFT;
1453 if (log2_size > mp->m_sectbb_log) {
1454 xfs_warn(mp, "Log sector size too large (0x%x > 0x%x)",
1455 log2_size, mp->m_sectbb_log);
1456 goto out_free_log;
1457 }
1458
1459 /* for larger sector sizes, must have v2 or external log */
1460 if (log2_size && log->l_logBBstart > 0 &&
1461 !xfs_sb_version_haslogv2(&mp->m_sb)) {
1462 xfs_warn(mp,
1463 "log sector size (0x%x) invalid for configuration.",
1464 log2_size);
1465 goto out_free_log;
1466 }
1467 }
1468 log->l_sectBBsize = 1 << log2_size;
1469
1470 xlog_get_iclog_buffer_size(mp, log);
1471
1472 /*
1473 * Use a NULL block for the extra log buffer used during splits so that
1474 * it will trigger errors if we ever try to do IO on it without first
1475 * having set it up properly.
1476 */
1477 error = -ENOMEM;
1478 bp = xfs_buf_alloc(mp->m_logdev_targp, XFS_BUF_DADDR_NULL,
1479 BTOBB(log->l_iclog_size), XBF_NO_IOACCT);
1480 if (!bp)
1481 goto out_free_log;
1482
1483 /*
1484 * The iclogbuf buffer locks are held over IO but we are not going to do
1485 * IO yet. Hence unlock the buffer so that the log IO path can grab it
1486 * when appropriately.
1487 */
1488 ASSERT(xfs_buf_islocked(bp));
1489 xfs_buf_unlock(bp);
1490
1491 /* use high priority wq for log I/O completion */
1492 bp->b_ioend_wq = mp->m_log_workqueue;
1493 bp->b_iodone = xlog_iodone;
1494 log->l_xbuf = bp;
1495
1496 spin_lock_init(&log->l_icloglock);
1497 init_waitqueue_head(&log->l_flush_wait);
1498
1499 iclogp = &log->l_iclog;
1500 /*
1501 * The amount of memory to allocate for the iclog structure is
1502 * rather funky due to the way the structure is defined. It is
1503 * done this way so that we can use different sizes for machines
1504 * with different amounts of memory. See the definition of
1505 * xlog_in_core_t in xfs_log_priv.h for details.
1506 */
1507 ASSERT(log->l_iclog_size >= 4096);
1508 for (i=0; i < log->l_iclog_bufs; i++) {
1509 *iclogp = kmem_zalloc(sizeof(xlog_in_core_t), KM_MAYFAIL);
1510 if (!*iclogp)
1511 goto out_free_iclog;
1512
1513 iclog = *iclogp;
1514 iclog->ic_prev = prev_iclog;
1515 prev_iclog = iclog;
1516
1517 bp = xfs_buf_get_uncached(mp->m_logdev_targp,
1518 BTOBB(log->l_iclog_size),
1519 XBF_NO_IOACCT);
1520 if (!bp)
1521 goto out_free_iclog;
1522
1523 ASSERT(xfs_buf_islocked(bp));
1524 xfs_buf_unlock(bp);
1525
1526 /* use high priority wq for log I/O completion */
1527 bp->b_ioend_wq = mp->m_log_workqueue;
1528 bp->b_iodone = xlog_iodone;
1529 iclog->ic_bp = bp;
1530 iclog->ic_data = bp->b_addr;
1531#ifdef DEBUG
1532 log->l_iclog_bak[i] = &iclog->ic_header;
1533#endif
1534 head = &iclog->ic_header;
1535 memset(head, 0, sizeof(xlog_rec_header_t));
1536 head->h_magicno = cpu_to_be32(XLOG_HEADER_MAGIC_NUM);
1537 head->h_version = cpu_to_be32(
1538 xfs_sb_version_haslogv2(&log->l_mp->m_sb) ? 2 : 1);
1539 head->h_size = cpu_to_be32(log->l_iclog_size);
1540 /* new fields */
1541 head->h_fmt = cpu_to_be32(XLOG_FMT);
1542 memcpy(&head->h_fs_uuid, &mp->m_sb.sb_uuid, sizeof(uuid_t));
1543
1544 iclog->ic_size = BBTOB(bp->b_length) - log->l_iclog_hsize;
1545 iclog->ic_state = XLOG_STATE_ACTIVE;
1546 iclog->ic_log = log;
1547 atomic_set(&iclog->ic_refcnt, 0);
1548 spin_lock_init(&iclog->ic_callback_lock);
1549 iclog->ic_callback_tail = &(iclog->ic_callback);
1550 iclog->ic_datap = (char *)iclog->ic_data + log->l_iclog_hsize;
1551
1552 init_waitqueue_head(&iclog->ic_force_wait);
1553 init_waitqueue_head(&iclog->ic_write_wait);
1554
1555 iclogp = &iclog->ic_next;
1556 }
1557 *iclogp = log->l_iclog; /* complete ring */
1558 log->l_iclog->ic_prev = prev_iclog; /* re-write 1st prev ptr */
1559
1560 error = xlog_cil_init(log);
1561 if (error)
1562 goto out_free_iclog;
1563 return log;
1564
1565out_free_iclog:
1566 for (iclog = log->l_iclog; iclog; iclog = prev_iclog) {
1567 prev_iclog = iclog->ic_next;
1568 if (iclog->ic_bp)
1569 xfs_buf_free(iclog->ic_bp);
1570 kmem_free(iclog);
1571 }
1572 spinlock_destroy(&log->l_icloglock);
1573 xfs_buf_free(log->l_xbuf);
1574out_free_log:
1575 kmem_free(log);
1576out:
1577 return ERR_PTR(error);
1578} /* xlog_alloc_log */
1579
1580
1581/*
1582 * Write out the commit record of a transaction associated with the given
1583 * ticket. Return the lsn of the commit record.
1584 */
1585STATIC int
1586xlog_commit_record(
1587 struct xlog *log,
1588 struct xlog_ticket *ticket,
1589 struct xlog_in_core **iclog,
1590 xfs_lsn_t *commitlsnp)
1591{
1592 struct xfs_mount *mp = log->l_mp;
1593 int error;
1594 struct xfs_log_iovec reg = {
1595 .i_addr = NULL,
1596 .i_len = 0,
1597 .i_type = XLOG_REG_TYPE_COMMIT,
1598 };
1599 struct xfs_log_vec vec = {
1600 .lv_niovecs = 1,
1601 .lv_iovecp = ®,
1602 };
1603
1604 ASSERT_ALWAYS(iclog);
1605 error = xlog_write(log, &vec, ticket, commitlsnp, iclog,
1606 XLOG_COMMIT_TRANS);
1607 if (error)
1608 xfs_force_shutdown(mp, SHUTDOWN_LOG_IO_ERROR);
1609 return error;
1610}
1611
1612/*
1613 * Push on the buffer cache code if we ever use more than 75% of the on-disk
1614 * log space. This code pushes on the lsn which would supposedly free up
1615 * the 25% which we want to leave free. We may need to adopt a policy which
1616 * pushes on an lsn which is further along in the log once we reach the high
1617 * water mark. In this manner, we would be creating a low water mark.
1618 */
1619STATIC void
1620xlog_grant_push_ail(
1621 struct xlog *log,
1622 int need_bytes)
1623{
1624 xfs_lsn_t threshold_lsn = 0;
1625 xfs_lsn_t last_sync_lsn;
1626 int free_blocks;
1627 int free_bytes;
1628 int threshold_block;
1629 int threshold_cycle;
1630 int free_threshold;
1631
1632 ASSERT(BTOBB(need_bytes) < log->l_logBBsize);
1633
1634 free_bytes = xlog_space_left(log, &log->l_reserve_head.grant);
1635 free_blocks = BTOBBT(free_bytes);
1636
1637 /*
1638 * Set the threshold for the minimum number of free blocks in the
1639 * log to the maximum of what the caller needs, one quarter of the
1640 * log, and 256 blocks.
1641 */
1642 free_threshold = BTOBB(need_bytes);
1643 free_threshold = MAX(free_threshold, (log->l_logBBsize >> 2));
1644 free_threshold = MAX(free_threshold, 256);
1645 if (free_blocks >= free_threshold)
1646 return;
1647
1648 xlog_crack_atomic_lsn(&log->l_tail_lsn, &threshold_cycle,
1649 &threshold_block);
1650 threshold_block += free_threshold;
1651 if (threshold_block >= log->l_logBBsize) {
1652 threshold_block -= log->l_logBBsize;
1653 threshold_cycle += 1;
1654 }
1655 threshold_lsn = xlog_assign_lsn(threshold_cycle,
1656 threshold_block);
1657 /*
1658 * Don't pass in an lsn greater than the lsn of the last
1659 * log record known to be on disk. Use a snapshot of the last sync lsn
1660 * so that it doesn't change between the compare and the set.
1661 */
1662 last_sync_lsn = atomic64_read(&log->l_last_sync_lsn);
1663 if (XFS_LSN_CMP(threshold_lsn, last_sync_lsn) > 0)
1664 threshold_lsn = last_sync_lsn;
1665
1666 /*
1667 * Get the transaction layer to kick the dirty buffers out to
1668 * disk asynchronously. No point in trying to do this if
1669 * the filesystem is shutting down.
1670 */
1671 if (!XLOG_FORCED_SHUTDOWN(log))
1672 xfs_ail_push(log->l_ailp, threshold_lsn);
1673}
1674
1675/*
1676 * Stamp cycle number in every block
1677 */
1678STATIC void
1679xlog_pack_data(
1680 struct xlog *log,
1681 struct xlog_in_core *iclog,
1682 int roundoff)
1683{
1684 int i, j, k;
1685 int size = iclog->ic_offset + roundoff;
1686 __be32 cycle_lsn;
1687 char *dp;
1688
1689 cycle_lsn = CYCLE_LSN_DISK(iclog->ic_header.h_lsn);
1690
1691 dp = iclog->ic_datap;
1692 for (i = 0; i < BTOBB(size); i++) {
1693 if (i >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE))
1694 break;
1695 iclog->ic_header.h_cycle_data[i] = *(__be32 *)dp;
1696 *(__be32 *)dp = cycle_lsn;
1697 dp += BBSIZE;
1698 }
1699
1700 if (xfs_sb_version_haslogv2(&log->l_mp->m_sb)) {
1701 xlog_in_core_2_t *xhdr = iclog->ic_data;
1702
1703 for ( ; i < BTOBB(size); i++) {
1704 j = i / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
1705 k = i % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
1706 xhdr[j].hic_xheader.xh_cycle_data[k] = *(__be32 *)dp;
1707 *(__be32 *)dp = cycle_lsn;
1708 dp += BBSIZE;
1709 }
1710
1711 for (i = 1; i < log->l_iclog_heads; i++)
1712 xhdr[i].hic_xheader.xh_cycle = cycle_lsn;
1713 }
1714}
1715
1716/*
1717 * Calculate the checksum for a log buffer.
1718 *
1719 * This is a little more complicated than it should be because the various
1720 * headers and the actual data are non-contiguous.
1721 */
1722__le32
1723xlog_cksum(
1724 struct xlog *log,
1725 struct xlog_rec_header *rhead,
1726 char *dp,
1727 int size)
1728{
1729 uint32_t crc;
1730
1731 /* first generate the crc for the record header ... */
1732 crc = xfs_start_cksum_update((char *)rhead,
1733 sizeof(struct xlog_rec_header),
1734 offsetof(struct xlog_rec_header, h_crc));
1735
1736 /* ... then for additional cycle data for v2 logs ... */
1737 if (xfs_sb_version_haslogv2(&log->l_mp->m_sb)) {
1738 union xlog_in_core2 *xhdr = (union xlog_in_core2 *)rhead;
1739 int i;
1740 int xheads;
1741
1742 xheads = size / XLOG_HEADER_CYCLE_SIZE;
1743 if (size % XLOG_HEADER_CYCLE_SIZE)
1744 xheads++;
1745
1746 for (i = 1; i < xheads; i++) {
1747 crc = crc32c(crc, &xhdr[i].hic_xheader,
1748 sizeof(struct xlog_rec_ext_header));
1749 }
1750 }
1751
1752 /* ... and finally for the payload */
1753 crc = crc32c(crc, dp, size);
1754
1755 return xfs_end_cksum(crc);
1756}
1757
1758/*
1759 * The bdstrat callback function for log bufs. This gives us a central
1760 * place to trap bufs in case we get hit by a log I/O error and need to
1761 * shutdown. Actually, in practice, even when we didn't get a log error,
1762 * we transition the iclogs to IOERROR state *after* flushing all existing
1763 * iclogs to disk. This is because we don't want anymore new transactions to be
1764 * started or completed afterwards.
1765 *
1766 * We lock the iclogbufs here so that we can serialise against IO completion
1767 * during unmount. We might be processing a shutdown triggered during unmount,
1768 * and that can occur asynchronously to the unmount thread, and hence we need to
1769 * ensure that completes before tearing down the iclogbufs. Hence we need to
1770 * hold the buffer lock across the log IO to acheive that.
1771 */
1772STATIC int
1773xlog_bdstrat(
1774 struct xfs_buf *bp)
1775{
1776 struct xlog_in_core *iclog = bp->b_log_item;
1777
1778 xfs_buf_lock(bp);
1779 if (iclog->ic_state & XLOG_STATE_IOERROR) {
1780 xfs_buf_ioerror(bp, -EIO);
1781 xfs_buf_stale(bp);
1782 xfs_buf_ioend(bp);
1783 /*
1784 * It would seem logical to return EIO here, but we rely on
1785 * the log state machine to propagate I/O errors instead of
1786 * doing it here. Similarly, IO completion will unlock the
1787 * buffer, so we don't do it here.
1788 */
1789 return 0;
1790 }
1791
1792 xfs_buf_submit(bp);
1793 return 0;
1794}
1795
1796/*
1797 * Flush out the in-core log (iclog) to the on-disk log in an asynchronous
1798 * fashion. Previously, we should have moved the current iclog
1799 * ptr in the log to point to the next available iclog. This allows further
1800 * write to continue while this code syncs out an iclog ready to go.
1801 * Before an in-core log can be written out, the data section must be scanned
1802 * to save away the 1st word of each BBSIZE block into the header. We replace
1803 * it with the current cycle count. Each BBSIZE block is tagged with the
1804 * cycle count because there in an implicit assumption that drives will
1805 * guarantee that entire 512 byte blocks get written at once. In other words,
1806 * we can't have part of a 512 byte block written and part not written. By
1807 * tagging each block, we will know which blocks are valid when recovering
1808 * after an unclean shutdown.
1809 *
1810 * This routine is single threaded on the iclog. No other thread can be in
1811 * this routine with the same iclog. Changing contents of iclog can there-
1812 * fore be done without grabbing the state machine lock. Updating the global
1813 * log will require grabbing the lock though.
1814 *
1815 * The entire log manager uses a logical block numbering scheme. Only
1816 * log_sync (and then only bwrite()) know about the fact that the log may
1817 * not start with block zero on a given device. The log block start offset
1818 * is added immediately before calling bwrite().
1819 */
1820
1821STATIC int
1822xlog_sync(
1823 struct xlog *log,
1824 struct xlog_in_core *iclog)
1825{
1826 xfs_buf_t *bp;
1827 int i;
1828 uint count; /* byte count of bwrite */
1829 uint count_init; /* initial count before roundup */
1830 int roundoff; /* roundoff to BB or stripe */
1831 int split = 0; /* split write into two regions */
1832 int error;
1833 int v2 = xfs_sb_version_haslogv2(&log->l_mp->m_sb);
1834 int size;
1835
1836 XFS_STATS_INC(log->l_mp, xs_log_writes);
1837 ASSERT(atomic_read(&iclog->ic_refcnt) == 0);
1838
1839 /* Add for LR header */
1840 count_init = log->l_iclog_hsize + iclog->ic_offset;
1841
1842 /* Round out the log write size */
1843 if (v2 && log->l_mp->m_sb.sb_logsunit > 1) {
1844 /* we have a v2 stripe unit to use */
1845 count = XLOG_LSUNITTOB(log, XLOG_BTOLSUNIT(log, count_init));
1846 } else {
1847 count = BBTOB(BTOBB(count_init));
1848 }
1849 roundoff = count - count_init;
1850 ASSERT(roundoff >= 0);
1851 ASSERT((v2 && log->l_mp->m_sb.sb_logsunit > 1 &&
1852 roundoff < log->l_mp->m_sb.sb_logsunit)
1853 ||
1854 (log->l_mp->m_sb.sb_logsunit <= 1 &&
1855 roundoff < BBTOB(1)));
1856
1857 /* move grant heads by roundoff in sync */
1858 xlog_grant_add_space(log, &log->l_reserve_head.grant, roundoff);
1859 xlog_grant_add_space(log, &log->l_write_head.grant, roundoff);
1860
1861 /* put cycle number in every block */
1862 xlog_pack_data(log, iclog, roundoff);
1863
1864 /* real byte length */
1865 size = iclog->ic_offset;
1866 if (v2)
1867 size += roundoff;
1868 iclog->ic_header.h_len = cpu_to_be32(size);
1869
1870 bp = iclog->ic_bp;
1871 XFS_BUF_SET_ADDR(bp, BLOCK_LSN(be64_to_cpu(iclog->ic_header.h_lsn)));
1872
1873 XFS_STATS_ADD(log->l_mp, xs_log_blocks, BTOBB(count));
1874
1875 /* Do we need to split this write into 2 parts? */
1876 if (XFS_BUF_ADDR(bp) + BTOBB(count) > log->l_logBBsize) {
1877 char *dptr;
1878
1879 split = count - (BBTOB(log->l_logBBsize - XFS_BUF_ADDR(bp)));
1880 count = BBTOB(log->l_logBBsize - XFS_BUF_ADDR(bp));
1881 iclog->ic_bwritecnt = 2;
1882
1883 /*
1884 * Bump the cycle numbers at the start of each block in the
1885 * part of the iclog that ends up in the buffer that gets
1886 * written to the start of the log.
1887 *
1888 * Watch out for the header magic number case, though.
1889 */
1890 dptr = (char *)&iclog->ic_header + count;
1891 for (i = 0; i < split; i += BBSIZE) {
1892 uint32_t cycle = be32_to_cpu(*(__be32 *)dptr);
1893 if (++cycle == XLOG_HEADER_MAGIC_NUM)
1894 cycle++;
1895 *(__be32 *)dptr = cpu_to_be32(cycle);
1896
1897 dptr += BBSIZE;
1898 }
1899 } else {
1900 iclog->ic_bwritecnt = 1;
1901 }
1902
1903 /* calculcate the checksum */
1904 iclog->ic_header.h_crc = xlog_cksum(log, &iclog->ic_header,
1905 iclog->ic_datap, size);
1906 /*
1907 * Intentionally corrupt the log record CRC based on the error injection
1908 * frequency, if defined. This facilitates testing log recovery in the
1909 * event of torn writes. Hence, set the IOABORT state to abort the log
1910 * write on I/O completion and shutdown the fs. The subsequent mount
1911 * detects the bad CRC and attempts to recover.
1912 */
1913 if (XFS_TEST_ERROR(false, log->l_mp, XFS_ERRTAG_LOG_BAD_CRC)) {
1914 iclog->ic_header.h_crc &= cpu_to_le32(0xAAAAAAAA);
1915 iclog->ic_state |= XLOG_STATE_IOABORT;
1916 xfs_warn(log->l_mp,
1917 "Intentionally corrupted log record at LSN 0x%llx. Shutdown imminent.",
1918 be64_to_cpu(iclog->ic_header.h_lsn));
1919 }
1920
1921 bp->b_io_length = BTOBB(count);
1922 bp->b_log_item = iclog;
1923 bp->b_flags &= ~XBF_FLUSH;
1924 bp->b_flags |= (XBF_ASYNC | XBF_SYNCIO | XBF_WRITE | XBF_FUA);
1925
1926 /*
1927 * Flush the data device before flushing the log to make sure all meta
1928 * data written back from the AIL actually made it to disk before
1929 * stamping the new log tail LSN into the log buffer. For an external
1930 * log we need to issue the flush explicitly, and unfortunately
1931 * synchronously here; for an internal log we can simply use the block
1932 * layer state machine for preflushes.
1933 */
1934 if (log->l_mp->m_logdev_targp != log->l_mp->m_ddev_targp)
1935 xfs_blkdev_issue_flush(log->l_mp->m_ddev_targp);
1936 else
1937 bp->b_flags |= XBF_FLUSH;
1938
1939 ASSERT(XFS_BUF_ADDR(bp) <= log->l_logBBsize-1);
1940 ASSERT(XFS_BUF_ADDR(bp) + BTOBB(count) <= log->l_logBBsize);
1941
1942 xlog_verify_iclog(log, iclog, count, true);
1943
1944 /* account for log which doesn't start at block #0 */
1945 XFS_BUF_SET_ADDR(bp, XFS_BUF_ADDR(bp) + log->l_logBBstart);
1946
1947 /*
1948 * Don't call xfs_bwrite here. We do log-syncs even when the filesystem
1949 * is shutting down.
1950 */
1951 error = xlog_bdstrat(bp);
1952 if (error) {
1953 xfs_buf_ioerror_alert(bp, "xlog_sync");
1954 return error;
1955 }
1956 if (split) {
1957 bp = iclog->ic_log->l_xbuf;
1958 XFS_BUF_SET_ADDR(bp, 0); /* logical 0 */
1959 xfs_buf_associate_memory(bp,
1960 (char *)&iclog->ic_header + count, split);
1961 bp->b_log_item = iclog;
1962 bp->b_flags &= ~XBF_FLUSH;
1963 bp->b_flags |= (XBF_ASYNC | XBF_SYNCIO | XBF_WRITE | XBF_FUA);
1964
1965 ASSERT(XFS_BUF_ADDR(bp) <= log->l_logBBsize-1);
1966 ASSERT(XFS_BUF_ADDR(bp) + BTOBB(count) <= log->l_logBBsize);
1967
1968 /* account for internal log which doesn't start at block #0 */
1969 XFS_BUF_SET_ADDR(bp, XFS_BUF_ADDR(bp) + log->l_logBBstart);
1970 error = xlog_bdstrat(bp);
1971 if (error) {
1972 xfs_buf_ioerror_alert(bp, "xlog_sync (split)");
1973 return error;
1974 }
1975 }
1976 return 0;
1977} /* xlog_sync */
1978
1979/*
1980 * Deallocate a log structure
1981 */
1982STATIC void
1983xlog_dealloc_log(
1984 struct xlog *log)
1985{
1986 xlog_in_core_t *iclog, *next_iclog;
1987 int i;
1988
1989 xlog_cil_destroy(log);
1990
1991 /*
1992 * Cycle all the iclogbuf locks to make sure all log IO completion
1993 * is done before we tear down these buffers.
1994 */
1995 iclog = log->l_iclog;
1996 for (i = 0; i < log->l_iclog_bufs; i++) {
1997 xfs_buf_lock(iclog->ic_bp);
1998 xfs_buf_unlock(iclog->ic_bp);
1999 iclog = iclog->ic_next;
2000 }
2001
2002 /*
2003 * Always need to ensure that the extra buffer does not point to memory
2004 * owned by another log buffer before we free it. Also, cycle the lock
2005 * first to ensure we've completed IO on it.
2006 */
2007 xfs_buf_lock(log->l_xbuf);
2008 xfs_buf_unlock(log->l_xbuf);
2009 xfs_buf_set_empty(log->l_xbuf, BTOBB(log->l_iclog_size));
2010 xfs_buf_free(log->l_xbuf);
2011
2012 iclog = log->l_iclog;
2013 for (i = 0; i < log->l_iclog_bufs; i++) {
2014 xfs_buf_free(iclog->ic_bp);
2015 next_iclog = iclog->ic_next;
2016 kmem_free(iclog);
2017 iclog = next_iclog;
2018 }
2019 spinlock_destroy(&log->l_icloglock);
2020
2021 log->l_mp->m_log = NULL;
2022 kmem_free(log);
2023} /* xlog_dealloc_log */
2024
2025/*
2026 * Update counters atomically now that memcpy is done.
2027 */
2028/* ARGSUSED */
2029static inline void
2030xlog_state_finish_copy(
2031 struct xlog *log,
2032 struct xlog_in_core *iclog,
2033 int record_cnt,
2034 int copy_bytes)
2035{
2036 spin_lock(&log->l_icloglock);
2037
2038 be32_add_cpu(&iclog->ic_header.h_num_logops, record_cnt);
2039 iclog->ic_offset += copy_bytes;
2040
2041 spin_unlock(&log->l_icloglock);
2042} /* xlog_state_finish_copy */
2043
2044
2045
2046
2047/*
2048 * print out info relating to regions written which consume
2049 * the reservation
2050 */
2051void
2052xlog_print_tic_res(
2053 struct xfs_mount *mp,
2054 struct xlog_ticket *ticket)
2055{
2056 uint i;
2057 uint ophdr_spc = ticket->t_res_num_ophdrs * (uint)sizeof(xlog_op_header_t);
2058
2059 /* match with XLOG_REG_TYPE_* in xfs_log.h */
2060#define REG_TYPE_STR(type, str) [XLOG_REG_TYPE_##type] = str
2061 static char *res_type_str[XLOG_REG_TYPE_MAX + 1] = {
2062 REG_TYPE_STR(BFORMAT, "bformat"),
2063 REG_TYPE_STR(BCHUNK, "bchunk"),
2064 REG_TYPE_STR(EFI_FORMAT, "efi_format"),
2065 REG_TYPE_STR(EFD_FORMAT, "efd_format"),
2066 REG_TYPE_STR(IFORMAT, "iformat"),
2067 REG_TYPE_STR(ICORE, "icore"),
2068 REG_TYPE_STR(IEXT, "iext"),
2069 REG_TYPE_STR(IBROOT, "ibroot"),
2070 REG_TYPE_STR(ILOCAL, "ilocal"),
2071 REG_TYPE_STR(IATTR_EXT, "iattr_ext"),
2072 REG_TYPE_STR(IATTR_BROOT, "iattr_broot"),
2073 REG_TYPE_STR(IATTR_LOCAL, "iattr_local"),
2074 REG_TYPE_STR(QFORMAT, "qformat"),
2075 REG_TYPE_STR(DQUOT, "dquot"),
2076 REG_TYPE_STR(QUOTAOFF, "quotaoff"),
2077 REG_TYPE_STR(LRHEADER, "LR header"),
2078 REG_TYPE_STR(UNMOUNT, "unmount"),
2079 REG_TYPE_STR(COMMIT, "commit"),
2080 REG_TYPE_STR(TRANSHDR, "trans header"),
2081 REG_TYPE_STR(ICREATE, "inode create")
2082 };
2083#undef REG_TYPE_STR
2084
2085 xfs_warn(mp, "ticket reservation summary:");
2086 xfs_warn(mp, " unit res = %d bytes",
2087 ticket->t_unit_res);
2088 xfs_warn(mp, " current res = %d bytes",
2089 ticket->t_curr_res);
2090 xfs_warn(mp, " total reg = %u bytes (o/flow = %u bytes)",
2091 ticket->t_res_arr_sum, ticket->t_res_o_flow);
2092 xfs_warn(mp, " ophdrs = %u (ophdr space = %u bytes)",
2093 ticket->t_res_num_ophdrs, ophdr_spc);
2094 xfs_warn(mp, " ophdr + reg = %u bytes",
2095 ticket->t_res_arr_sum + ticket->t_res_o_flow + ophdr_spc);
2096 xfs_warn(mp, " num regions = %u",
2097 ticket->t_res_num);
2098
2099 for (i = 0; i < ticket->t_res_num; i++) {
2100 uint r_type = ticket->t_res_arr[i].r_type;
2101 xfs_warn(mp, "region[%u]: %s - %u bytes", i,
2102 ((r_type <= 0 || r_type > XLOG_REG_TYPE_MAX) ?
2103 "bad-rtype" : res_type_str[r_type]),
2104 ticket->t_res_arr[i].r_len);
2105 }
2106}
2107
2108/*
2109 * Print a summary of the transaction.
2110 */
2111void
2112xlog_print_trans(
2113 struct xfs_trans *tp)
2114{
2115 struct xfs_mount *mp = tp->t_mountp;
2116 struct xfs_log_item_desc *lidp;
2117
2118 /* dump core transaction and ticket info */
2119 xfs_warn(mp, "transaction summary:");
2120 xfs_warn(mp, " log res = %d", tp->t_log_res);
2121 xfs_warn(mp, " log count = %d", tp->t_log_count);
2122 xfs_warn(mp, " flags = 0x%x", tp->t_flags);
2123
2124 xlog_print_tic_res(mp, tp->t_ticket);
2125
2126 /* dump each log item */
2127 list_for_each_entry(lidp, &tp->t_items, lid_trans) {
2128 struct xfs_log_item *lip = lidp->lid_item;
2129 struct xfs_log_vec *lv = lip->li_lv;
2130 struct xfs_log_iovec *vec;
2131 int i;
2132
2133 xfs_warn(mp, "log item: ");
2134 xfs_warn(mp, " type = 0x%x", lip->li_type);
2135 xfs_warn(mp, " flags = 0x%x", lip->li_flags);
2136 if (!lv)
2137 continue;
2138 xfs_warn(mp, " niovecs = %d", lv->lv_niovecs);
2139 xfs_warn(mp, " size = %d", lv->lv_size);
2140 xfs_warn(mp, " bytes = %d", lv->lv_bytes);
2141 xfs_warn(mp, " buf len = %d", lv->lv_buf_len);
2142
2143 /* dump each iovec for the log item */
2144 vec = lv->lv_iovecp;
2145 for (i = 0; i < lv->lv_niovecs; i++) {
2146 int dumplen = min(vec->i_len, 32);
2147
2148 xfs_warn(mp, " iovec[%d]", i);
2149 xfs_warn(mp, " type = 0x%x", vec->i_type);
2150 xfs_warn(mp, " len = %d", vec->i_len);
2151 xfs_warn(mp, " first %d bytes of iovec[%d]:", dumplen, i);
2152 xfs_hex_dump(vec->i_addr, dumplen);
2153
2154 vec++;
2155 }
2156 }
2157}
2158
2159/*
2160 * Calculate the potential space needed by the log vector. Each region gets
2161 * its own xlog_op_header_t and may need to be double word aligned.
2162 */
2163static int
2164xlog_write_calc_vec_length(
2165 struct xlog_ticket *ticket,
2166 struct xfs_log_vec *log_vector)
2167{
2168 struct xfs_log_vec *lv;
2169 int headers = 0;
2170 int len = 0;
2171 int i;
2172
2173 /* acct for start rec of xact */
2174 if (ticket->t_flags & XLOG_TIC_INITED)
2175 headers++;
2176
2177 for (lv = log_vector; lv; lv = lv->lv_next) {
2178 /* we don't write ordered log vectors */
2179 if (lv->lv_buf_len == XFS_LOG_VEC_ORDERED)
2180 continue;
2181
2182 headers += lv->lv_niovecs;
2183
2184 for (i = 0; i < lv->lv_niovecs; i++) {
2185 struct xfs_log_iovec *vecp = &lv->lv_iovecp[i];
2186
2187 len += vecp->i_len;
2188 xlog_tic_add_region(ticket, vecp->i_len, vecp->i_type);
2189 }
2190 }
2191
2192 ticket->t_res_num_ophdrs += headers;
2193 len += headers * sizeof(struct xlog_op_header);
2194
2195 return len;
2196}
2197
2198/*
2199 * If first write for transaction, insert start record We can't be trying to
2200 * commit if we are inited. We can't have any "partial_copy" if we are inited.
2201 */
2202static int
2203xlog_write_start_rec(
2204 struct xlog_op_header *ophdr,
2205 struct xlog_ticket *ticket)
2206{
2207 if (!(ticket->t_flags & XLOG_TIC_INITED))
2208 return 0;
2209
2210 ophdr->oh_tid = cpu_to_be32(ticket->t_tid);
2211 ophdr->oh_clientid = ticket->t_clientid;
2212 ophdr->oh_len = 0;
2213 ophdr->oh_flags = XLOG_START_TRANS;
2214 ophdr->oh_res2 = 0;
2215
2216 ticket->t_flags &= ~XLOG_TIC_INITED;
2217
2218 return sizeof(struct xlog_op_header);
2219}
2220
2221static xlog_op_header_t *
2222xlog_write_setup_ophdr(
2223 struct xlog *log,
2224 struct xlog_op_header *ophdr,
2225 struct xlog_ticket *ticket,
2226 uint flags)
2227{
2228 ophdr->oh_tid = cpu_to_be32(ticket->t_tid);
2229 ophdr->oh_clientid = ticket->t_clientid;
2230 ophdr->oh_res2 = 0;
2231
2232 /* are we copying a commit or unmount record? */
2233 ophdr->oh_flags = flags;
2234
2235 /*
2236 * We've seen logs corrupted with bad transaction client ids. This
2237 * makes sure that XFS doesn't generate them on. Turn this into an EIO
2238 * and shut down the filesystem.
2239 */
2240 switch (ophdr->oh_clientid) {
2241 case XFS_TRANSACTION:
2242 case XFS_VOLUME:
2243 case XFS_LOG:
2244 break;
2245 default:
2246 xfs_warn(log->l_mp,
2247 "Bad XFS transaction clientid 0x%x in ticket "PTR_FMT,
2248 ophdr->oh_clientid, ticket);
2249 return NULL;
2250 }
2251
2252 return ophdr;
2253}
2254
2255/*
2256 * Set up the parameters of the region copy into the log. This has
2257 * to handle region write split across multiple log buffers - this
2258 * state is kept external to this function so that this code can
2259 * be written in an obvious, self documenting manner.
2260 */
2261static int
2262xlog_write_setup_copy(
2263 struct xlog_ticket *ticket,
2264 struct xlog_op_header *ophdr,
2265 int space_available,
2266 int space_required,
2267 int *copy_off,
2268 int *copy_len,
2269 int *last_was_partial_copy,
2270 int *bytes_consumed)
2271{
2272 int still_to_copy;
2273
2274 still_to_copy = space_required - *bytes_consumed;
2275 *copy_off = *bytes_consumed;
2276
2277 if (still_to_copy <= space_available) {
2278 /* write of region completes here */
2279 *copy_len = still_to_copy;
2280 ophdr->oh_len = cpu_to_be32(*copy_len);
2281 if (*last_was_partial_copy)
2282 ophdr->oh_flags |= (XLOG_END_TRANS|XLOG_WAS_CONT_TRANS);
2283 *last_was_partial_copy = 0;
2284 *bytes_consumed = 0;
2285 return 0;
2286 }
2287
2288 /* partial write of region, needs extra log op header reservation */
2289 *copy_len = space_available;
2290 ophdr->oh_len = cpu_to_be32(*copy_len);
2291 ophdr->oh_flags |= XLOG_CONTINUE_TRANS;
2292 if (*last_was_partial_copy)
2293 ophdr->oh_flags |= XLOG_WAS_CONT_TRANS;
2294 *bytes_consumed += *copy_len;
2295 (*last_was_partial_copy)++;
2296
2297 /* account for new log op header */
2298 ticket->t_curr_res -= sizeof(struct xlog_op_header);
2299 ticket->t_res_num_ophdrs++;
2300
2301 return sizeof(struct xlog_op_header);
2302}
2303
2304static int
2305xlog_write_copy_finish(
2306 struct xlog *log,
2307 struct xlog_in_core *iclog,
2308 uint flags,
2309 int *record_cnt,
2310 int *data_cnt,
2311 int *partial_copy,
2312 int *partial_copy_len,
2313 int log_offset,
2314 struct xlog_in_core **commit_iclog)
2315{
2316 if (*partial_copy) {
2317 /*
2318 * This iclog has already been marked WANT_SYNC by
2319 * xlog_state_get_iclog_space.
2320 */
2321 xlog_state_finish_copy(log, iclog, *record_cnt, *data_cnt);
2322 *record_cnt = 0;
2323 *data_cnt = 0;
2324 return xlog_state_release_iclog(log, iclog);
2325 }
2326
2327 *partial_copy = 0;
2328 *partial_copy_len = 0;
2329
2330 if (iclog->ic_size - log_offset <= sizeof(xlog_op_header_t)) {
2331 /* no more space in this iclog - push it. */
2332 xlog_state_finish_copy(log, iclog, *record_cnt, *data_cnt);
2333 *record_cnt = 0;
2334 *data_cnt = 0;
2335
2336 spin_lock(&log->l_icloglock);
2337 xlog_state_want_sync(log, iclog);
2338 spin_unlock(&log->l_icloglock);
2339
2340 if (!commit_iclog)
2341 return xlog_state_release_iclog(log, iclog);
2342 ASSERT(flags & XLOG_COMMIT_TRANS);
2343 *commit_iclog = iclog;
2344 }
2345
2346 return 0;
2347}
2348
2349/*
2350 * Write some region out to in-core log
2351 *
2352 * This will be called when writing externally provided regions or when
2353 * writing out a commit record for a given transaction.
2354 *
2355 * General algorithm:
2356 * 1. Find total length of this write. This may include adding to the
2357 * lengths passed in.
2358 * 2. Check whether we violate the tickets reservation.
2359 * 3. While writing to this iclog
2360 * A. Reserve as much space in this iclog as can get
2361 * B. If this is first write, save away start lsn
2362 * C. While writing this region:
2363 * 1. If first write of transaction, write start record
2364 * 2. Write log operation header (header per region)
2365 * 3. Find out if we can fit entire region into this iclog
2366 * 4. Potentially, verify destination memcpy ptr
2367 * 5. Memcpy (partial) region
2368 * 6. If partial copy, release iclog; otherwise, continue
2369 * copying more regions into current iclog
2370 * 4. Mark want sync bit (in simulation mode)
2371 * 5. Release iclog for potential flush to on-disk log.
2372 *
2373 * ERRORS:
2374 * 1. Panic if reservation is overrun. This should never happen since
2375 * reservation amounts are generated internal to the filesystem.
2376 * NOTES:
2377 * 1. Tickets are single threaded data structures.
2378 * 2. The XLOG_END_TRANS & XLOG_CONTINUE_TRANS flags are passed down to the
2379 * syncing routine. When a single log_write region needs to span
2380 * multiple in-core logs, the XLOG_CONTINUE_TRANS bit should be set
2381 * on all log operation writes which don't contain the end of the
2382 * region. The XLOG_END_TRANS bit is used for the in-core log
2383 * operation which contains the end of the continued log_write region.
2384 * 3. When xlog_state_get_iclog_space() grabs the rest of the current iclog,
2385 * we don't really know exactly how much space will be used. As a result,
2386 * we don't update ic_offset until the end when we know exactly how many
2387 * bytes have been written out.
2388 */
2389int
2390xlog_write(
2391 struct xlog *log,
2392 struct xfs_log_vec *log_vector,
2393 struct xlog_ticket *ticket,
2394 xfs_lsn_t *start_lsn,
2395 struct xlog_in_core **commit_iclog,
2396 uint flags)
2397{
2398 struct xlog_in_core *iclog = NULL;
2399 struct xfs_log_iovec *vecp;
2400 struct xfs_log_vec *lv;
2401 int len;
2402 int index;
2403 int partial_copy = 0;
2404 int partial_copy_len = 0;
2405 int contwr = 0;
2406 int record_cnt = 0;
2407 int data_cnt = 0;
2408 int error;
2409
2410 *start_lsn = 0;
2411
2412 len = xlog_write_calc_vec_length(ticket, log_vector);
2413
2414 /*
2415 * Region headers and bytes are already accounted for.
2416 * We only need to take into account start records and
2417 * split regions in this function.
2418 */
2419 if (ticket->t_flags & XLOG_TIC_INITED)
2420 ticket->t_curr_res -= sizeof(xlog_op_header_t);
2421
2422 /*
2423 * Commit record headers need to be accounted for. These
2424 * come in as separate writes so are easy to detect.
2425 */
2426 if (flags & (XLOG_COMMIT_TRANS | XLOG_UNMOUNT_TRANS))
2427 ticket->t_curr_res -= sizeof(xlog_op_header_t);
2428
2429 if (ticket->t_curr_res < 0) {
2430 xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES,
2431 "ctx ticket reservation ran out. Need to up reservation");
2432 xlog_print_tic_res(log->l_mp, ticket);
2433 xfs_force_shutdown(log->l_mp, SHUTDOWN_LOG_IO_ERROR);
2434 }
2435
2436 index = 0;
2437 lv = log_vector;
2438 vecp = lv->lv_iovecp;
2439 while (lv && (!lv->lv_niovecs || index < lv->lv_niovecs)) {
2440 void *ptr;
2441 int log_offset;
2442
2443 error = xlog_state_get_iclog_space(log, len, &iclog, ticket,
2444 &contwr, &log_offset);
2445 if (error)
2446 return error;
2447
2448 ASSERT(log_offset <= iclog->ic_size - 1);
2449 ptr = iclog->ic_datap + log_offset;
2450
2451 /* start_lsn is the first lsn written to. That's all we need. */
2452 if (!*start_lsn)
2453 *start_lsn = be64_to_cpu(iclog->ic_header.h_lsn);
2454
2455 /*
2456 * This loop writes out as many regions as can fit in the amount
2457 * of space which was allocated by xlog_state_get_iclog_space().
2458 */
2459 while (lv && (!lv->lv_niovecs || index < lv->lv_niovecs)) {
2460 struct xfs_log_iovec *reg;
2461 struct xlog_op_header *ophdr;
2462 int start_rec_copy;
2463 int copy_len;
2464 int copy_off;
2465 bool ordered = false;
2466
2467 /* ordered log vectors have no regions to write */
2468 if (lv->lv_buf_len == XFS_LOG_VEC_ORDERED) {
2469 ASSERT(lv->lv_niovecs == 0);
2470 ordered = true;
2471 goto next_lv;
2472 }
2473
2474 reg = &vecp[index];
2475 ASSERT(reg->i_len % sizeof(int32_t) == 0);
2476 ASSERT((unsigned long)ptr % sizeof(int32_t) == 0);
2477
2478 start_rec_copy = xlog_write_start_rec(ptr, ticket);
2479 if (start_rec_copy) {
2480 record_cnt++;
2481 xlog_write_adv_cnt(&ptr, &len, &log_offset,
2482 start_rec_copy);
2483 }
2484
2485 ophdr = xlog_write_setup_ophdr(log, ptr, ticket, flags);
2486 if (!ophdr)
2487 return -EIO;
2488
2489 xlog_write_adv_cnt(&ptr, &len, &log_offset,
2490 sizeof(struct xlog_op_header));
2491
2492 len += xlog_write_setup_copy(ticket, ophdr,
2493 iclog->ic_size-log_offset,
2494 reg->i_len,
2495 ©_off, ©_len,
2496 &partial_copy,
2497 &partial_copy_len);
2498 xlog_verify_dest_ptr(log, ptr);
2499
2500 /*
2501 * Copy region.
2502 *
2503 * Unmount records just log an opheader, so can have
2504 * empty payloads with no data region to copy. Hence we
2505 * only copy the payload if the vector says it has data
2506 * to copy.
2507 */
2508 ASSERT(copy_len >= 0);
2509 if (copy_len > 0) {
2510 memcpy(ptr, reg->i_addr + copy_off, copy_len);
2511 xlog_write_adv_cnt(&ptr, &len, &log_offset,
2512 copy_len);
2513 }
2514 copy_len += start_rec_copy + sizeof(xlog_op_header_t);
2515 record_cnt++;
2516 data_cnt += contwr ? copy_len : 0;
2517
2518 error = xlog_write_copy_finish(log, iclog, flags,
2519 &record_cnt, &data_cnt,
2520 &partial_copy,
2521 &partial_copy_len,
2522 log_offset,
2523 commit_iclog);
2524 if (error)
2525 return error;
2526
2527 /*
2528 * if we had a partial copy, we need to get more iclog
2529 * space but we don't want to increment the region
2530 * index because there is still more is this region to
2531 * write.
2532 *
2533 * If we completed writing this region, and we flushed
2534 * the iclog (indicated by resetting of the record
2535 * count), then we also need to get more log space. If
2536 * this was the last record, though, we are done and
2537 * can just return.
2538 */
2539 if (partial_copy)
2540 break;
2541
2542 if (++index == lv->lv_niovecs) {
2543next_lv:
2544 lv = lv->lv_next;
2545 index = 0;
2546 if (lv)
2547 vecp = lv->lv_iovecp;
2548 }
2549 if (record_cnt == 0 && !ordered) {
2550 if (!lv)
2551 return 0;
2552 break;
2553 }
2554 }
2555 }
2556
2557 ASSERT(len == 0);
2558
2559 xlog_state_finish_copy(log, iclog, record_cnt, data_cnt);
2560 if (!commit_iclog)
2561 return xlog_state_release_iclog(log, iclog);
2562
2563 ASSERT(flags & XLOG_COMMIT_TRANS);
2564 *commit_iclog = iclog;
2565 return 0;
2566}
2567
2568
2569/*****************************************************************************
2570 *
2571 * State Machine functions
2572 *
2573 *****************************************************************************
2574 */
2575
2576/* Clean iclogs starting from the head. This ordering must be
2577 * maintained, so an iclog doesn't become ACTIVE beyond one that
2578 * is SYNCING. This is also required to maintain the notion that we use
2579 * a ordered wait queue to hold off would be writers to the log when every
2580 * iclog is trying to sync to disk.
2581 *
2582 * State Change: DIRTY -> ACTIVE
2583 */
2584STATIC void
2585xlog_state_clean_log(
2586 struct xlog *log)
2587{
2588 xlog_in_core_t *iclog;
2589 int changed = 0;
2590
2591 iclog = log->l_iclog;
2592 do {
2593 if (iclog->ic_state == XLOG_STATE_DIRTY) {
2594 iclog->ic_state = XLOG_STATE_ACTIVE;
2595 iclog->ic_offset = 0;
2596 ASSERT(iclog->ic_callback == NULL);
2597 /*
2598 * If the number of ops in this iclog indicate it just
2599 * contains the dummy transaction, we can
2600 * change state into IDLE (the second time around).
2601 * Otherwise we should change the state into
2602 * NEED a dummy.
2603 * We don't need to cover the dummy.
2604 */
2605 if (!changed &&
2606 (be32_to_cpu(iclog->ic_header.h_num_logops) ==
2607 XLOG_COVER_OPS)) {
2608 changed = 1;
2609 } else {
2610 /*
2611 * We have two dirty iclogs so start over
2612 * This could also be num of ops indicates
2613 * this is not the dummy going out.
2614 */
2615 changed = 2;
2616 }
2617 iclog->ic_header.h_num_logops = 0;
2618 memset(iclog->ic_header.h_cycle_data, 0,
2619 sizeof(iclog->ic_header.h_cycle_data));
2620 iclog->ic_header.h_lsn = 0;
2621 } else if (iclog->ic_state == XLOG_STATE_ACTIVE)
2622 /* do nothing */;
2623 else
2624 break; /* stop cleaning */
2625 iclog = iclog->ic_next;
2626 } while (iclog != log->l_iclog);
2627
2628 /* log is locked when we are called */
2629 /*
2630 * Change state for the dummy log recording.
2631 * We usually go to NEED. But we go to NEED2 if the changed indicates
2632 * we are done writing the dummy record.
2633 * If we are done with the second dummy recored (DONE2), then
2634 * we go to IDLE.
2635 */
2636 if (changed) {
2637 switch (log->l_covered_state) {
2638 case XLOG_STATE_COVER_IDLE:
2639 case XLOG_STATE_COVER_NEED:
2640 case XLOG_STATE_COVER_NEED2:
2641 log->l_covered_state = XLOG_STATE_COVER_NEED;
2642 break;
2643
2644 case XLOG_STATE_COVER_DONE:
2645 if (changed == 1)
2646 log->l_covered_state = XLOG_STATE_COVER_NEED2;
2647 else
2648 log->l_covered_state = XLOG_STATE_COVER_NEED;
2649 break;
2650
2651 case XLOG_STATE_COVER_DONE2:
2652 if (changed == 1)
2653 log->l_covered_state = XLOG_STATE_COVER_IDLE;
2654 else
2655 log->l_covered_state = XLOG_STATE_COVER_NEED;
2656 break;
2657
2658 default:
2659 ASSERT(0);
2660 }
2661 }
2662} /* xlog_state_clean_log */
2663
2664STATIC xfs_lsn_t
2665xlog_get_lowest_lsn(
2666 struct xlog *log)
2667{
2668 xlog_in_core_t *lsn_log;
2669 xfs_lsn_t lowest_lsn, lsn;
2670
2671 lsn_log = log->l_iclog;
2672 lowest_lsn = 0;
2673 do {
2674 if (!(lsn_log->ic_state & (XLOG_STATE_ACTIVE|XLOG_STATE_DIRTY))) {
2675 lsn = be64_to_cpu(lsn_log->ic_header.h_lsn);
2676 if ((lsn && !lowest_lsn) ||
2677 (XFS_LSN_CMP(lsn, lowest_lsn) < 0)) {
2678 lowest_lsn = lsn;
2679 }
2680 }
2681 lsn_log = lsn_log->ic_next;
2682 } while (lsn_log != log->l_iclog);
2683 return lowest_lsn;
2684}
2685
2686
2687STATIC void
2688xlog_state_do_callback(
2689 struct xlog *log,
2690 int aborted,
2691 struct xlog_in_core *ciclog)
2692{
2693 xlog_in_core_t *iclog;
2694 xlog_in_core_t *first_iclog; /* used to know when we've
2695 * processed all iclogs once */
2696 xfs_log_callback_t *cb, *cb_next;
2697 int flushcnt = 0;
2698 xfs_lsn_t lowest_lsn;
2699 int ioerrors; /* counter: iclogs with errors */
2700 int loopdidcallbacks; /* flag: inner loop did callbacks*/
2701 int funcdidcallbacks; /* flag: function did callbacks */
2702 int repeats; /* for issuing console warnings if
2703 * looping too many times */
2704 int wake = 0;
2705
2706 spin_lock(&log->l_icloglock);
2707 first_iclog = iclog = log->l_iclog;
2708 ioerrors = 0;
2709 funcdidcallbacks = 0;
2710 repeats = 0;
2711
2712 do {
2713 /*
2714 * Scan all iclogs starting with the one pointed to by the
2715 * log. Reset this starting point each time the log is
2716 * unlocked (during callbacks).
2717 *
2718 * Keep looping through iclogs until one full pass is made
2719 * without running any callbacks.
2720 */
2721 first_iclog = log->l_iclog;
2722 iclog = log->l_iclog;
2723 loopdidcallbacks = 0;
2724 repeats++;
2725
2726 do {
2727
2728 /* skip all iclogs in the ACTIVE & DIRTY states */
2729 if (iclog->ic_state &
2730 (XLOG_STATE_ACTIVE|XLOG_STATE_DIRTY)) {
2731 iclog = iclog->ic_next;
2732 continue;
2733 }
2734
2735 /*
2736 * Between marking a filesystem SHUTDOWN and stopping
2737 * the log, we do flush all iclogs to disk (if there
2738 * wasn't a log I/O error). So, we do want things to
2739 * go smoothly in case of just a SHUTDOWN w/o a
2740 * LOG_IO_ERROR.
2741 */
2742 if (!(iclog->ic_state & XLOG_STATE_IOERROR)) {
2743 /*
2744 * Can only perform callbacks in order. Since
2745 * this iclog is not in the DONE_SYNC/
2746 * DO_CALLBACK state, we skip the rest and
2747 * just try to clean up. If we set our iclog
2748 * to DO_CALLBACK, we will not process it when
2749 * we retry since a previous iclog is in the
2750 * CALLBACK and the state cannot change since
2751 * we are holding the l_icloglock.
2752 */
2753 if (!(iclog->ic_state &
2754 (XLOG_STATE_DONE_SYNC |
2755 XLOG_STATE_DO_CALLBACK))) {
2756 if (ciclog && (ciclog->ic_state ==
2757 XLOG_STATE_DONE_SYNC)) {
2758 ciclog->ic_state = XLOG_STATE_DO_CALLBACK;
2759 }
2760 break;
2761 }
2762 /*
2763 * We now have an iclog that is in either the
2764 * DO_CALLBACK or DONE_SYNC states. The other
2765 * states (WANT_SYNC, SYNCING, or CALLBACK were
2766 * caught by the above if and are going to
2767 * clean (i.e. we aren't doing their callbacks)
2768 * see the above if.
2769 */
2770
2771 /*
2772 * We will do one more check here to see if we
2773 * have chased our tail around.
2774 */
2775
2776 lowest_lsn = xlog_get_lowest_lsn(log);
2777 if (lowest_lsn &&
2778 XFS_LSN_CMP(lowest_lsn,
2779 be64_to_cpu(iclog->ic_header.h_lsn)) < 0) {
2780 iclog = iclog->ic_next;
2781 continue; /* Leave this iclog for
2782 * another thread */
2783 }
2784
2785 iclog->ic_state = XLOG_STATE_CALLBACK;
2786
2787
2788 /*
2789 * Completion of a iclog IO does not imply that
2790 * a transaction has completed, as transactions
2791 * can be large enough to span many iclogs. We
2792 * cannot change the tail of the log half way
2793 * through a transaction as this may be the only
2794 * transaction in the log and moving th etail to
2795 * point to the middle of it will prevent
2796 * recovery from finding the start of the
2797 * transaction. Hence we should only update the
2798 * last_sync_lsn if this iclog contains
2799 * transaction completion callbacks on it.
2800 *
2801 * We have to do this before we drop the
2802 * icloglock to ensure we are the only one that
2803 * can update it.
2804 */
2805 ASSERT(XFS_LSN_CMP(atomic64_read(&log->l_last_sync_lsn),
2806 be64_to_cpu(iclog->ic_header.h_lsn)) <= 0);
2807 if (iclog->ic_callback)
2808 atomic64_set(&log->l_last_sync_lsn,
2809 be64_to_cpu(iclog->ic_header.h_lsn));
2810
2811 } else
2812 ioerrors++;
2813
2814 spin_unlock(&log->l_icloglock);
2815
2816 /*
2817 * Keep processing entries in the callback list until
2818 * we come around and it is empty. We need to
2819 * atomically see that the list is empty and change the
2820 * state to DIRTY so that we don't miss any more
2821 * callbacks being added.
2822 */
2823 spin_lock(&iclog->ic_callback_lock);
2824 cb = iclog->ic_callback;
2825 while (cb) {
2826 iclog->ic_callback_tail = &(iclog->ic_callback);
2827 iclog->ic_callback = NULL;
2828 spin_unlock(&iclog->ic_callback_lock);
2829
2830 /* perform callbacks in the order given */
2831 for (; cb; cb = cb_next) {
2832 cb_next = cb->cb_next;
2833 cb->cb_func(cb->cb_arg, aborted);
2834 }
2835 spin_lock(&iclog->ic_callback_lock);
2836 cb = iclog->ic_callback;
2837 }
2838
2839 loopdidcallbacks++;
2840 funcdidcallbacks++;
2841
2842 spin_lock(&log->l_icloglock);
2843 ASSERT(iclog->ic_callback == NULL);
2844 spin_unlock(&iclog->ic_callback_lock);
2845 if (!(iclog->ic_state & XLOG_STATE_IOERROR))
2846 iclog->ic_state = XLOG_STATE_DIRTY;
2847
2848 /*
2849 * Transition from DIRTY to ACTIVE if applicable.
2850 * NOP if STATE_IOERROR.
2851 */
2852 xlog_state_clean_log(log);
2853
2854 /* wake up threads waiting in xfs_log_force() */
2855 wake_up_all(&iclog->ic_force_wait);
2856
2857 iclog = iclog->ic_next;
2858 } while (first_iclog != iclog);
2859
2860 if (repeats > 5000) {
2861 flushcnt += repeats;
2862 repeats = 0;
2863 xfs_warn(log->l_mp,
2864 "%s: possible infinite loop (%d iterations)",
2865 __func__, flushcnt);
2866 }
2867 } while (!ioerrors && loopdidcallbacks);
2868
2869#ifdef DEBUG
2870 /*
2871 * Make one last gasp attempt to see if iclogs are being left in limbo.
2872 * If the above loop finds an iclog earlier than the current iclog and
2873 * in one of the syncing states, the current iclog is put into
2874 * DO_CALLBACK and the callbacks are deferred to the completion of the
2875 * earlier iclog. Walk the iclogs in order and make sure that no iclog
2876 * is in DO_CALLBACK unless an earlier iclog is in one of the syncing
2877 * states.
2878 *
2879 * Note that SYNCING|IOABORT is a valid state so we cannot just check
2880 * for ic_state == SYNCING.
2881 */
2882 if (funcdidcallbacks) {
2883 first_iclog = iclog = log->l_iclog;
2884 do {
2885 ASSERT(iclog->ic_state != XLOG_STATE_DO_CALLBACK);
2886 /*
2887 * Terminate the loop if iclogs are found in states
2888 * which will cause other threads to clean up iclogs.
2889 *
2890 * SYNCING - i/o completion will go through logs
2891 * DONE_SYNC - interrupt thread should be waiting for
2892 * l_icloglock
2893 * IOERROR - give up hope all ye who enter here
2894 */
2895 if (iclog->ic_state == XLOG_STATE_WANT_SYNC ||
2896 iclog->ic_state & XLOG_STATE_SYNCING ||
2897 iclog->ic_state == XLOG_STATE_DONE_SYNC ||
2898 iclog->ic_state == XLOG_STATE_IOERROR )
2899 break;
2900 iclog = iclog->ic_next;
2901 } while (first_iclog != iclog);
2902 }
2903#endif
2904
2905 if (log->l_iclog->ic_state & (XLOG_STATE_ACTIVE|XLOG_STATE_IOERROR))
2906 wake = 1;
2907 spin_unlock(&log->l_icloglock);
2908
2909 if (wake)
2910 wake_up_all(&log->l_flush_wait);
2911}
2912
2913
2914/*
2915 * Finish transitioning this iclog to the dirty state.
2916 *
2917 * Make sure that we completely execute this routine only when this is
2918 * the last call to the iclog. There is a good chance that iclog flushes,
2919 * when we reach the end of the physical log, get turned into 2 separate
2920 * calls to bwrite. Hence, one iclog flush could generate two calls to this
2921 * routine. By using the reference count bwritecnt, we guarantee that only
2922 * the second completion goes through.
2923 *
2924 * Callbacks could take time, so they are done outside the scope of the
2925 * global state machine log lock.
2926 */
2927STATIC void
2928xlog_state_done_syncing(
2929 xlog_in_core_t *iclog,
2930 int aborted)
2931{
2932 struct xlog *log = iclog->ic_log;
2933
2934 spin_lock(&log->l_icloglock);
2935
2936 ASSERT(iclog->ic_state == XLOG_STATE_SYNCING ||
2937 iclog->ic_state == XLOG_STATE_IOERROR);
2938 ASSERT(atomic_read(&iclog->ic_refcnt) == 0);
2939 ASSERT(iclog->ic_bwritecnt == 1 || iclog->ic_bwritecnt == 2);
2940
2941
2942 /*
2943 * If we got an error, either on the first buffer, or in the case of
2944 * split log writes, on the second, we mark ALL iclogs STATE_IOERROR,
2945 * and none should ever be attempted to be written to disk
2946 * again.
2947 */
2948 if (iclog->ic_state != XLOG_STATE_IOERROR) {
2949 if (--iclog->ic_bwritecnt == 1) {
2950 spin_unlock(&log->l_icloglock);
2951 return;
2952 }
2953 iclog->ic_state = XLOG_STATE_DONE_SYNC;
2954 }
2955
2956 /*
2957 * Someone could be sleeping prior to writing out the next
2958 * iclog buffer, we wake them all, one will get to do the
2959 * I/O, the others get to wait for the result.
2960 */
2961 wake_up_all(&iclog->ic_write_wait);
2962 spin_unlock(&log->l_icloglock);
2963 xlog_state_do_callback(log, aborted, iclog); /* also cleans log */
2964} /* xlog_state_done_syncing */
2965
2966
2967/*
2968 * If the head of the in-core log ring is not (ACTIVE or DIRTY), then we must
2969 * sleep. We wait on the flush queue on the head iclog as that should be
2970 * the first iclog to complete flushing. Hence if all iclogs are syncing,
2971 * we will wait here and all new writes will sleep until a sync completes.
2972 *
2973 * The in-core logs are used in a circular fashion. They are not used
2974 * out-of-order even when an iclog past the head is free.
2975 *
2976 * return:
2977 * * log_offset where xlog_write() can start writing into the in-core
2978 * log's data space.
2979 * * in-core log pointer to which xlog_write() should write.
2980 * * boolean indicating this is a continued write to an in-core log.
2981 * If this is the last write, then the in-core log's offset field
2982 * needs to be incremented, depending on the amount of data which
2983 * is copied.
2984 */
2985STATIC int
2986xlog_state_get_iclog_space(
2987 struct xlog *log,
2988 int len,
2989 struct xlog_in_core **iclogp,
2990 struct xlog_ticket *ticket,
2991 int *continued_write,
2992 int *logoffsetp)
2993{
2994 int log_offset;
2995 xlog_rec_header_t *head;
2996 xlog_in_core_t *iclog;
2997 int error;
2998
2999restart:
3000 spin_lock(&log->l_icloglock);
3001 if (XLOG_FORCED_SHUTDOWN(log)) {
3002 spin_unlock(&log->l_icloglock);
3003 return -EIO;
3004 }
3005
3006 iclog = log->l_iclog;
3007 if (iclog->ic_state != XLOG_STATE_ACTIVE) {
3008 XFS_STATS_INC(log->l_mp, xs_log_noiclogs);
3009
3010 /* Wait for log writes to have flushed */
3011 xlog_wait(&log->l_flush_wait, &log->l_icloglock);
3012 goto restart;
3013 }
3014
3015 head = &iclog->ic_header;
3016
3017 atomic_inc(&iclog->ic_refcnt); /* prevents sync */
3018 log_offset = iclog->ic_offset;
3019
3020 /* On the 1st write to an iclog, figure out lsn. This works
3021 * if iclogs marked XLOG_STATE_WANT_SYNC always write out what they are
3022 * committing to. If the offset is set, that's how many blocks
3023 * must be written.
3024 */
3025 if (log_offset == 0) {
3026 ticket->t_curr_res -= log->l_iclog_hsize;
3027 xlog_tic_add_region(ticket,
3028 log->l_iclog_hsize,
3029 XLOG_REG_TYPE_LRHEADER);
3030 head->h_cycle = cpu_to_be32(log->l_curr_cycle);
3031 head->h_lsn = cpu_to_be64(
3032 xlog_assign_lsn(log->l_curr_cycle, log->l_curr_block));
3033 ASSERT(log->l_curr_block >= 0);
3034 }
3035
3036 /* If there is enough room to write everything, then do it. Otherwise,
3037 * claim the rest of the region and make sure the XLOG_STATE_WANT_SYNC
3038 * bit is on, so this will get flushed out. Don't update ic_offset
3039 * until you know exactly how many bytes get copied. Therefore, wait
3040 * until later to update ic_offset.
3041 *
3042 * xlog_write() algorithm assumes that at least 2 xlog_op_header_t's
3043 * can fit into remaining data section.
3044 */
3045 if (iclog->ic_size - iclog->ic_offset < 2*sizeof(xlog_op_header_t)) {
3046 xlog_state_switch_iclogs(log, iclog, iclog->ic_size);
3047
3048 /*
3049 * If I'm the only one writing to this iclog, sync it to disk.
3050 * We need to do an atomic compare and decrement here to avoid
3051 * racing with concurrent atomic_dec_and_lock() calls in
3052 * xlog_state_release_iclog() when there is more than one
3053 * reference to the iclog.
3054 */
3055 if (!atomic_add_unless(&iclog->ic_refcnt, -1, 1)) {
3056 /* we are the only one */
3057 spin_unlock(&log->l_icloglock);
3058 error = xlog_state_release_iclog(log, iclog);
3059 if (error)
3060 return error;
3061 } else {
3062 spin_unlock(&log->l_icloglock);
3063 }
3064 goto restart;
3065 }
3066
3067 /* Do we have enough room to write the full amount in the remainder
3068 * of this iclog? Or must we continue a write on the next iclog and
3069 * mark this iclog as completely taken? In the case where we switch
3070 * iclogs (to mark it taken), this particular iclog will release/sync
3071 * to disk in xlog_write().
3072 */
3073 if (len <= iclog->ic_size - iclog->ic_offset) {
3074 *continued_write = 0;
3075 iclog->ic_offset += len;
3076 } else {
3077 *continued_write = 1;
3078 xlog_state_switch_iclogs(log, iclog, iclog->ic_size);
3079 }
3080 *iclogp = iclog;
3081
3082 ASSERT(iclog->ic_offset <= iclog->ic_size);
3083 spin_unlock(&log->l_icloglock);
3084
3085 *logoffsetp = log_offset;
3086 return 0;
3087} /* xlog_state_get_iclog_space */
3088
3089/* The first cnt-1 times through here we don't need to
3090 * move the grant write head because the permanent
3091 * reservation has reserved cnt times the unit amount.
3092 * Release part of current permanent unit reservation and
3093 * reset current reservation to be one units worth. Also
3094 * move grant reservation head forward.
3095 */
3096STATIC void
3097xlog_regrant_reserve_log_space(
3098 struct xlog *log,
3099 struct xlog_ticket *ticket)
3100{
3101 trace_xfs_log_regrant_reserve_enter(log, ticket);
3102
3103 if (ticket->t_cnt > 0)
3104 ticket->t_cnt--;
3105
3106 xlog_grant_sub_space(log, &log->l_reserve_head.grant,
3107 ticket->t_curr_res);
3108 xlog_grant_sub_space(log, &log->l_write_head.grant,
3109 ticket->t_curr_res);
3110 ticket->t_curr_res = ticket->t_unit_res;
3111 xlog_tic_reset_res(ticket);
3112
3113 trace_xfs_log_regrant_reserve_sub(log, ticket);
3114
3115 /* just return if we still have some of the pre-reserved space */
3116 if (ticket->t_cnt > 0)
3117 return;
3118
3119 xlog_grant_add_space(log, &log->l_reserve_head.grant,
3120 ticket->t_unit_res);
3121
3122 trace_xfs_log_regrant_reserve_exit(log, ticket);
3123
3124 ticket->t_curr_res = ticket->t_unit_res;
3125 xlog_tic_reset_res(ticket);
3126} /* xlog_regrant_reserve_log_space */
3127
3128
3129/*
3130 * Give back the space left from a reservation.
3131 *
3132 * All the information we need to make a correct determination of space left
3133 * is present. For non-permanent reservations, things are quite easy. The
3134 * count should have been decremented to zero. We only need to deal with the
3135 * space remaining in the current reservation part of the ticket. If the
3136 * ticket contains a permanent reservation, there may be left over space which
3137 * needs to be released. A count of N means that N-1 refills of the current
3138 * reservation can be done before we need to ask for more space. The first
3139 * one goes to fill up the first current reservation. Once we run out of
3140 * space, the count will stay at zero and the only space remaining will be
3141 * in the current reservation field.
3142 */
3143STATIC void
3144xlog_ungrant_log_space(
3145 struct xlog *log,
3146 struct xlog_ticket *ticket)
3147{
3148 int bytes;
3149
3150 if (ticket->t_cnt > 0)
3151 ticket->t_cnt--;
3152
3153 trace_xfs_log_ungrant_enter(log, ticket);
3154 trace_xfs_log_ungrant_sub(log, ticket);
3155
3156 /*
3157 * If this is a permanent reservation ticket, we may be able to free
3158 * up more space based on the remaining count.
3159 */
3160 bytes = ticket->t_curr_res;
3161 if (ticket->t_cnt > 0) {
3162 ASSERT(ticket->t_flags & XLOG_TIC_PERM_RESERV);
3163 bytes += ticket->t_unit_res*ticket->t_cnt;
3164 }
3165
3166 xlog_grant_sub_space(log, &log->l_reserve_head.grant, bytes);
3167 xlog_grant_sub_space(log, &log->l_write_head.grant, bytes);
3168
3169 trace_xfs_log_ungrant_exit(log, ticket);
3170
3171 xfs_log_space_wake(log->l_mp);
3172}
3173
3174/*
3175 * Flush iclog to disk if this is the last reference to the given iclog and
3176 * the WANT_SYNC bit is set.
3177 *
3178 * When this function is entered, the iclog is not necessarily in the
3179 * WANT_SYNC state. It may be sitting around waiting to get filled.
3180 *
3181 *
3182 */
3183STATIC int
3184xlog_state_release_iclog(
3185 struct xlog *log,
3186 struct xlog_in_core *iclog)
3187{
3188 int sync = 0; /* do we sync? */
3189
3190 if (iclog->ic_state & XLOG_STATE_IOERROR)
3191 return -EIO;
3192
3193 ASSERT(atomic_read(&iclog->ic_refcnt) > 0);
3194 if (!atomic_dec_and_lock(&iclog->ic_refcnt, &log->l_icloglock))
3195 return 0;
3196
3197 if (iclog->ic_state & XLOG_STATE_IOERROR) {
3198 spin_unlock(&log->l_icloglock);
3199 return -EIO;
3200 }
3201 ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE ||
3202 iclog->ic_state == XLOG_STATE_WANT_SYNC);
3203
3204 if (iclog->ic_state == XLOG_STATE_WANT_SYNC) {
3205 /* update tail before writing to iclog */
3206 xfs_lsn_t tail_lsn = xlog_assign_tail_lsn(log->l_mp);
3207 sync++;
3208 iclog->ic_state = XLOG_STATE_SYNCING;
3209 iclog->ic_header.h_tail_lsn = cpu_to_be64(tail_lsn);
3210 xlog_verify_tail_lsn(log, iclog, tail_lsn);
3211 /* cycle incremented when incrementing curr_block */
3212 }
3213 spin_unlock(&log->l_icloglock);
3214
3215 /*
3216 * We let the log lock go, so it's possible that we hit a log I/O
3217 * error or some other SHUTDOWN condition that marks the iclog
3218 * as XLOG_STATE_IOERROR before the bwrite. However, we know that
3219 * this iclog has consistent data, so we ignore IOERROR
3220 * flags after this point.
3221 */
3222 if (sync)
3223 return xlog_sync(log, iclog);
3224 return 0;
3225} /* xlog_state_release_iclog */
3226
3227
3228/*
3229 * This routine will mark the current iclog in the ring as WANT_SYNC
3230 * and move the current iclog pointer to the next iclog in the ring.
3231 * When this routine is called from xlog_state_get_iclog_space(), the
3232 * exact size of the iclog has not yet been determined. All we know is
3233 * that every data block. We have run out of space in this log record.
3234 */
3235STATIC void
3236xlog_state_switch_iclogs(
3237 struct xlog *log,
3238 struct xlog_in_core *iclog,
3239 int eventual_size)
3240{
3241 ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE);
3242 if (!eventual_size)
3243 eventual_size = iclog->ic_offset;
3244 iclog->ic_state = XLOG_STATE_WANT_SYNC;
3245 iclog->ic_header.h_prev_block = cpu_to_be32(log->l_prev_block);
3246 log->l_prev_block = log->l_curr_block;
3247 log->l_prev_cycle = log->l_curr_cycle;
3248
3249 /* roll log?: ic_offset changed later */
3250 log->l_curr_block += BTOBB(eventual_size)+BTOBB(log->l_iclog_hsize);
3251
3252 /* Round up to next log-sunit */
3253 if (xfs_sb_version_haslogv2(&log->l_mp->m_sb) &&
3254 log->l_mp->m_sb.sb_logsunit > 1) {
3255 uint32_t sunit_bb = BTOBB(log->l_mp->m_sb.sb_logsunit);
3256 log->l_curr_block = roundup(log->l_curr_block, sunit_bb);
3257 }
3258
3259 if (log->l_curr_block >= log->l_logBBsize) {
3260 /*
3261 * Rewind the current block before the cycle is bumped to make
3262 * sure that the combined LSN never transiently moves forward
3263 * when the log wraps to the next cycle. This is to support the
3264 * unlocked sample of these fields from xlog_valid_lsn(). Most
3265 * other cases should acquire l_icloglock.
3266 */
3267 log->l_curr_block -= log->l_logBBsize;
3268 ASSERT(log->l_curr_block >= 0);
3269 smp_wmb();
3270 log->l_curr_cycle++;
3271 if (log->l_curr_cycle == XLOG_HEADER_MAGIC_NUM)
3272 log->l_curr_cycle++;
3273 }
3274 ASSERT(iclog == log->l_iclog);
3275 log->l_iclog = iclog->ic_next;
3276} /* xlog_state_switch_iclogs */
3277
3278/*
3279 * Write out all data in the in-core log as of this exact moment in time.
3280 *
3281 * Data may be written to the in-core log during this call. However,
3282 * we don't guarantee this data will be written out. A change from past
3283 * implementation means this routine will *not* write out zero length LRs.
3284 *
3285 * Basically, we try and perform an intelligent scan of the in-core logs.
3286 * If we determine there is no flushable data, we just return. There is no
3287 * flushable data if:
3288 *
3289 * 1. the current iclog is active and has no data; the previous iclog
3290 * is in the active or dirty state.
3291 * 2. the current iclog is drity, and the previous iclog is in the
3292 * active or dirty state.
3293 *
3294 * We may sleep if:
3295 *
3296 * 1. the current iclog is not in the active nor dirty state.
3297 * 2. the current iclog dirty, and the previous iclog is not in the
3298 * active nor dirty state.
3299 * 3. the current iclog is active, and there is another thread writing
3300 * to this particular iclog.
3301 * 4. a) the current iclog is active and has no other writers
3302 * b) when we return from flushing out this iclog, it is still
3303 * not in the active nor dirty state.
3304 */
3305int
3306xfs_log_force(
3307 struct xfs_mount *mp,
3308 uint flags)
3309{
3310 struct xlog *log = mp->m_log;
3311 struct xlog_in_core *iclog;
3312 xfs_lsn_t lsn;
3313
3314 XFS_STATS_INC(mp, xs_log_force);
3315 trace_xfs_log_force(mp, 0, _RET_IP_);
3316
3317 xlog_cil_force(log);
3318
3319 spin_lock(&log->l_icloglock);
3320 iclog = log->l_iclog;
3321 if (iclog->ic_state & XLOG_STATE_IOERROR)
3322 goto out_error;
3323
3324 if (iclog->ic_state == XLOG_STATE_DIRTY ||
3325 (iclog->ic_state == XLOG_STATE_ACTIVE &&
3326 atomic_read(&iclog->ic_refcnt) == 0 && iclog->ic_offset == 0)) {
3327 /*
3328 * If the head is dirty or (active and empty), then we need to
3329 * look at the previous iclog.
3330 *
3331 * If the previous iclog is active or dirty we are done. There
3332 * is nothing to sync out. Otherwise, we attach ourselves to the
3333 * previous iclog and go to sleep.
3334 */
3335 iclog = iclog->ic_prev;
3336 if (iclog->ic_state == XLOG_STATE_ACTIVE ||
3337 iclog->ic_state == XLOG_STATE_DIRTY)
3338 goto out_unlock;
3339 } else if (iclog->ic_state == XLOG_STATE_ACTIVE) {
3340 if (atomic_read(&iclog->ic_refcnt) == 0) {
3341 /*
3342 * We are the only one with access to this iclog.
3343 *
3344 * Flush it out now. There should be a roundoff of zero
3345 * to show that someone has already taken care of the
3346 * roundoff from the previous sync.
3347 */
3348 atomic_inc(&iclog->ic_refcnt);
3349 lsn = be64_to_cpu(iclog->ic_header.h_lsn);
3350 xlog_state_switch_iclogs(log, iclog, 0);
3351 spin_unlock(&log->l_icloglock);
3352
3353 if (xlog_state_release_iclog(log, iclog))
3354 return -EIO;
3355
3356 spin_lock(&log->l_icloglock);
3357 if (be64_to_cpu(iclog->ic_header.h_lsn) != lsn ||
3358 iclog->ic_state == XLOG_STATE_DIRTY)
3359 goto out_unlock;
3360 } else {
3361 /*
3362 * Someone else is writing to this iclog.
3363 *
3364 * Use its call to flush out the data. However, the
3365 * other thread may not force out this LR, so we mark
3366 * it WANT_SYNC.
3367 */
3368 xlog_state_switch_iclogs(log, iclog, 0);
3369 }
3370 } else {
3371 /*
3372 * If the head iclog is not active nor dirty, we just attach
3373 * ourselves to the head and go to sleep if necessary.
3374 */
3375 ;
3376 }
3377
3378 if (!(flags & XFS_LOG_SYNC))
3379 goto out_unlock;
3380
3381 if (iclog->ic_state & XLOG_STATE_IOERROR)
3382 goto out_error;
3383 XFS_STATS_INC(mp, xs_log_force_sleep);
3384 xlog_wait(&iclog->ic_force_wait, &log->l_icloglock);
3385 if (iclog->ic_state & XLOG_STATE_IOERROR)
3386 return -EIO;
3387 return 0;
3388
3389out_unlock:
3390 spin_unlock(&log->l_icloglock);
3391 return 0;
3392out_error:
3393 spin_unlock(&log->l_icloglock);
3394 return -EIO;
3395}
3396
3397static int
3398__xfs_log_force_lsn(
3399 struct xfs_mount *mp,
3400 xfs_lsn_t lsn,
3401 uint flags,
3402 int *log_flushed,
3403 bool already_slept)
3404{
3405 struct xlog *log = mp->m_log;
3406 struct xlog_in_core *iclog;
3407
3408 spin_lock(&log->l_icloglock);
3409 iclog = log->l_iclog;
3410 if (iclog->ic_state & XLOG_STATE_IOERROR)
3411 goto out_error;
3412
3413 while (be64_to_cpu(iclog->ic_header.h_lsn) != lsn) {
3414 iclog = iclog->ic_next;
3415 if (iclog == log->l_iclog)
3416 goto out_unlock;
3417 }
3418
3419 if (iclog->ic_state == XLOG_STATE_DIRTY)
3420 goto out_unlock;
3421
3422 if (iclog->ic_state == XLOG_STATE_ACTIVE) {
3423 /*
3424 * We sleep here if we haven't already slept (e.g. this is the
3425 * first time we've looked at the correct iclog buf) and the
3426 * buffer before us is going to be sync'ed. The reason for this
3427 * is that if we are doing sync transactions here, by waiting
3428 * for the previous I/O to complete, we can allow a few more
3429 * transactions into this iclog before we close it down.
3430 *
3431 * Otherwise, we mark the buffer WANT_SYNC, and bump up the
3432 * refcnt so we can release the log (which drops the ref count).
3433 * The state switch keeps new transaction commits from using
3434 * this buffer. When the current commits finish writing into
3435 * the buffer, the refcount will drop to zero and the buffer
3436 * will go out then.
3437 */
3438 if (!already_slept &&
3439 (iclog->ic_prev->ic_state &
3440 (XLOG_STATE_WANT_SYNC | XLOG_STATE_SYNCING))) {
3441 ASSERT(!(iclog->ic_state & XLOG_STATE_IOERROR));
3442
3443 XFS_STATS_INC(mp, xs_log_force_sleep);
3444
3445 xlog_wait(&iclog->ic_prev->ic_write_wait,
3446 &log->l_icloglock);
3447 return -EAGAIN;
3448 }
3449 atomic_inc(&iclog->ic_refcnt);
3450 xlog_state_switch_iclogs(log, iclog, 0);
3451 spin_unlock(&log->l_icloglock);
3452 if (xlog_state_release_iclog(log, iclog))
3453 return -EIO;
3454 if (log_flushed)
3455 *log_flushed = 1;
3456 spin_lock(&log->l_icloglock);
3457 }
3458
3459 if (!(flags & XFS_LOG_SYNC) ||
3460 (iclog->ic_state & (XLOG_STATE_ACTIVE | XLOG_STATE_DIRTY)))
3461 goto out_unlock;
3462
3463 if (iclog->ic_state & XLOG_STATE_IOERROR)
3464 goto out_error;
3465
3466 XFS_STATS_INC(mp, xs_log_force_sleep);
3467 xlog_wait(&iclog->ic_force_wait, &log->l_icloglock);
3468 if (iclog->ic_state & XLOG_STATE_IOERROR)
3469 return -EIO;
3470 return 0;
3471
3472out_unlock:
3473 spin_unlock(&log->l_icloglock);
3474 return 0;
3475out_error:
3476 spin_unlock(&log->l_icloglock);
3477 return -EIO;
3478}
3479
3480/*
3481 * Force the in-core log to disk for a specific LSN.
3482 *
3483 * Find in-core log with lsn.
3484 * If it is in the DIRTY state, just return.
3485 * If it is in the ACTIVE state, move the in-core log into the WANT_SYNC
3486 * state and go to sleep or return.
3487 * If it is in any other state, go to sleep or return.
3488 *
3489 * Synchronous forces are implemented with a wait queue. All callers trying
3490 * to force a given lsn to disk must wait on the queue attached to the
3491 * specific in-core log. When given in-core log finally completes its write
3492 * to disk, that thread will wake up all threads waiting on the queue.
3493 */
3494int
3495xfs_log_force_lsn(
3496 struct xfs_mount *mp,
3497 xfs_lsn_t lsn,
3498 uint flags,
3499 int *log_flushed)
3500{
3501 int ret;
3502 ASSERT(lsn != 0);
3503
3504 XFS_STATS_INC(mp, xs_log_force);
3505 trace_xfs_log_force(mp, lsn, _RET_IP_);
3506
3507 lsn = xlog_cil_force_lsn(mp->m_log, lsn);
3508 if (lsn == NULLCOMMITLSN)
3509 return 0;
3510
3511 ret = __xfs_log_force_lsn(mp, lsn, flags, log_flushed, false);
3512 if (ret == -EAGAIN)
3513 ret = __xfs_log_force_lsn(mp, lsn, flags, log_flushed, true);
3514 return ret;
3515}
3516
3517/*
3518 * Called when we want to mark the current iclog as being ready to sync to
3519 * disk.
3520 */
3521STATIC void
3522xlog_state_want_sync(
3523 struct xlog *log,
3524 struct xlog_in_core *iclog)
3525{
3526 assert_spin_locked(&log->l_icloglock);
3527
3528 if (iclog->ic_state == XLOG_STATE_ACTIVE) {
3529 xlog_state_switch_iclogs(log, iclog, 0);
3530 } else {
3531 ASSERT(iclog->ic_state &
3532 (XLOG_STATE_WANT_SYNC|XLOG_STATE_IOERROR));
3533 }
3534}
3535
3536
3537/*****************************************************************************
3538 *
3539 * TICKET functions
3540 *
3541 *****************************************************************************
3542 */
3543
3544/*
3545 * Free a used ticket when its refcount falls to zero.
3546 */
3547void
3548xfs_log_ticket_put(
3549 xlog_ticket_t *ticket)
3550{
3551 ASSERT(atomic_read(&ticket->t_ref) > 0);
3552 if (atomic_dec_and_test(&ticket->t_ref))
3553 kmem_zone_free(xfs_log_ticket_zone, ticket);
3554}
3555
3556xlog_ticket_t *
3557xfs_log_ticket_get(
3558 xlog_ticket_t *ticket)
3559{
3560 ASSERT(atomic_read(&ticket->t_ref) > 0);
3561 atomic_inc(&ticket->t_ref);
3562 return ticket;
3563}
3564
3565/*
3566 * Figure out the total log space unit (in bytes) that would be
3567 * required for a log ticket.
3568 */
3569int
3570xfs_log_calc_unit_res(
3571 struct xfs_mount *mp,
3572 int unit_bytes)
3573{
3574 struct xlog *log = mp->m_log;
3575 int iclog_space;
3576 uint num_headers;
3577
3578 /*
3579 * Permanent reservations have up to 'cnt'-1 active log operations
3580 * in the log. A unit in this case is the amount of space for one
3581 * of these log operations. Normal reservations have a cnt of 1
3582 * and their unit amount is the total amount of space required.
3583 *
3584 * The following lines of code account for non-transaction data
3585 * which occupy space in the on-disk log.
3586 *
3587 * Normal form of a transaction is:
3588 * <oph><trans-hdr><start-oph><reg1-oph><reg1><reg2-oph>...<commit-oph>
3589 * and then there are LR hdrs, split-recs and roundoff at end of syncs.
3590 *
3591 * We need to account for all the leadup data and trailer data
3592 * around the transaction data.
3593 * And then we need to account for the worst case in terms of using
3594 * more space.
3595 * The worst case will happen if:
3596 * - the placement of the transaction happens to be such that the
3597 * roundoff is at its maximum
3598 * - the transaction data is synced before the commit record is synced
3599 * i.e. <transaction-data><roundoff> | <commit-rec><roundoff>
3600 * Therefore the commit record is in its own Log Record.
3601 * This can happen as the commit record is called with its
3602 * own region to xlog_write().
3603 * This then means that in the worst case, roundoff can happen for
3604 * the commit-rec as well.
3605 * The commit-rec is smaller than padding in this scenario and so it is
3606 * not added separately.
3607 */
3608
3609 /* for trans header */
3610 unit_bytes += sizeof(xlog_op_header_t);
3611 unit_bytes += sizeof(xfs_trans_header_t);
3612
3613 /* for start-rec */
3614 unit_bytes += sizeof(xlog_op_header_t);
3615
3616 /*
3617 * for LR headers - the space for data in an iclog is the size minus
3618 * the space used for the headers. If we use the iclog size, then we
3619 * undercalculate the number of headers required.
3620 *
3621 * Furthermore - the addition of op headers for split-recs might
3622 * increase the space required enough to require more log and op
3623 * headers, so take that into account too.
3624 *
3625 * IMPORTANT: This reservation makes the assumption that if this
3626 * transaction is the first in an iclog and hence has the LR headers
3627 * accounted to it, then the remaining space in the iclog is
3628 * exclusively for this transaction. i.e. if the transaction is larger
3629 * than the iclog, it will be the only thing in that iclog.
3630 * Fundamentally, this means we must pass the entire log vector to
3631 * xlog_write to guarantee this.
3632 */
3633 iclog_space = log->l_iclog_size - log->l_iclog_hsize;
3634 num_headers = howmany(unit_bytes, iclog_space);
3635
3636 /* for split-recs - ophdrs added when data split over LRs */
3637 unit_bytes += sizeof(xlog_op_header_t) * num_headers;
3638
3639 /* add extra header reservations if we overrun */
3640 while (!num_headers ||
3641 howmany(unit_bytes, iclog_space) > num_headers) {
3642 unit_bytes += sizeof(xlog_op_header_t);
3643 num_headers++;
3644 }
3645 unit_bytes += log->l_iclog_hsize * num_headers;
3646
3647 /* for commit-rec LR header - note: padding will subsume the ophdr */
3648 unit_bytes += log->l_iclog_hsize;
3649
3650 /* for roundoff padding for transaction data and one for commit record */
3651 if (xfs_sb_version_haslogv2(&mp->m_sb) && mp->m_sb.sb_logsunit > 1) {
3652 /* log su roundoff */
3653 unit_bytes += 2 * mp->m_sb.sb_logsunit;
3654 } else {
3655 /* BB roundoff */
3656 unit_bytes += 2 * BBSIZE;
3657 }
3658
3659 return unit_bytes;
3660}
3661
3662/*
3663 * Allocate and initialise a new log ticket.
3664 */
3665struct xlog_ticket *
3666xlog_ticket_alloc(
3667 struct xlog *log,
3668 int unit_bytes,
3669 int cnt,
3670 char client,
3671 bool permanent,
3672 xfs_km_flags_t alloc_flags)
3673{
3674 struct xlog_ticket *tic;
3675 int unit_res;
3676
3677 tic = kmem_zone_zalloc(xfs_log_ticket_zone, alloc_flags);
3678 if (!tic)
3679 return NULL;
3680
3681 unit_res = xfs_log_calc_unit_res(log->l_mp, unit_bytes);
3682
3683 atomic_set(&tic->t_ref, 1);
3684 tic->t_task = current;
3685 INIT_LIST_HEAD(&tic->t_queue);
3686 tic->t_unit_res = unit_res;
3687 tic->t_curr_res = unit_res;
3688 tic->t_cnt = cnt;
3689 tic->t_ocnt = cnt;
3690 tic->t_tid = prandom_u32();
3691 tic->t_clientid = client;
3692 tic->t_flags = XLOG_TIC_INITED;
3693 if (permanent)
3694 tic->t_flags |= XLOG_TIC_PERM_RESERV;
3695
3696 xlog_tic_reset_res(tic);
3697
3698 return tic;
3699}
3700
3701
3702/******************************************************************************
3703 *
3704 * Log debug routines
3705 *
3706 ******************************************************************************
3707 */
3708#if defined(DEBUG)
3709/*
3710 * Make sure that the destination ptr is within the valid data region of
3711 * one of the iclogs. This uses backup pointers stored in a different
3712 * part of the log in case we trash the log structure.
3713 */
3714STATIC void
3715xlog_verify_dest_ptr(
3716 struct xlog *log,
3717 void *ptr)
3718{
3719 int i;
3720 int good_ptr = 0;
3721
3722 for (i = 0; i < log->l_iclog_bufs; i++) {
3723 if (ptr >= log->l_iclog_bak[i] &&
3724 ptr <= log->l_iclog_bak[i] + log->l_iclog_size)
3725 good_ptr++;
3726 }
3727
3728 if (!good_ptr)
3729 xfs_emerg(log->l_mp, "%s: invalid ptr", __func__);
3730}
3731
3732/*
3733 * Check to make sure the grant write head didn't just over lap the tail. If
3734 * the cycles are the same, we can't be overlapping. Otherwise, make sure that
3735 * the cycles differ by exactly one and check the byte count.
3736 *
3737 * This check is run unlocked, so can give false positives. Rather than assert
3738 * on failures, use a warn-once flag and a panic tag to allow the admin to
3739 * determine if they want to panic the machine when such an error occurs. For
3740 * debug kernels this will have the same effect as using an assert but, unlinke
3741 * an assert, it can be turned off at runtime.
3742 */
3743STATIC void
3744xlog_verify_grant_tail(
3745 struct xlog *log)
3746{
3747 int tail_cycle, tail_blocks;
3748 int cycle, space;
3749
3750 xlog_crack_grant_head(&log->l_write_head.grant, &cycle, &space);
3751 xlog_crack_atomic_lsn(&log->l_tail_lsn, &tail_cycle, &tail_blocks);
3752 if (tail_cycle != cycle) {
3753 if (cycle - 1 != tail_cycle &&
3754 !(log->l_flags & XLOG_TAIL_WARN)) {
3755 xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES,
3756 "%s: cycle - 1 != tail_cycle", __func__);
3757 log->l_flags |= XLOG_TAIL_WARN;
3758 }
3759
3760 if (space > BBTOB(tail_blocks) &&
3761 !(log->l_flags & XLOG_TAIL_WARN)) {
3762 xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES,
3763 "%s: space > BBTOB(tail_blocks)", __func__);
3764 log->l_flags |= XLOG_TAIL_WARN;
3765 }
3766 }
3767}
3768
3769/* check if it will fit */
3770STATIC void
3771xlog_verify_tail_lsn(
3772 struct xlog *log,
3773 struct xlog_in_core *iclog,
3774 xfs_lsn_t tail_lsn)
3775{
3776 int blocks;
3777
3778 if (CYCLE_LSN(tail_lsn) == log->l_prev_cycle) {
3779 blocks =
3780 log->l_logBBsize - (log->l_prev_block - BLOCK_LSN(tail_lsn));
3781 if (blocks < BTOBB(iclog->ic_offset)+BTOBB(log->l_iclog_hsize))
3782 xfs_emerg(log->l_mp, "%s: ran out of log space", __func__);
3783 } else {
3784 ASSERT(CYCLE_LSN(tail_lsn)+1 == log->l_prev_cycle);
3785
3786 if (BLOCK_LSN(tail_lsn) == log->l_prev_block)
3787 xfs_emerg(log->l_mp, "%s: tail wrapped", __func__);
3788
3789 blocks = BLOCK_LSN(tail_lsn) - log->l_prev_block;
3790 if (blocks < BTOBB(iclog->ic_offset) + 1)
3791 xfs_emerg(log->l_mp, "%s: ran out of log space", __func__);
3792 }
3793} /* xlog_verify_tail_lsn */
3794
3795/*
3796 * Perform a number of checks on the iclog before writing to disk.
3797 *
3798 * 1. Make sure the iclogs are still circular
3799 * 2. Make sure we have a good magic number
3800 * 3. Make sure we don't have magic numbers in the data
3801 * 4. Check fields of each log operation header for:
3802 * A. Valid client identifier
3803 * B. tid ptr value falls in valid ptr space (user space code)
3804 * C. Length in log record header is correct according to the
3805 * individual operation headers within record.
3806 * 5. When a bwrite will occur within 5 blocks of the front of the physical
3807 * log, check the preceding blocks of the physical log to make sure all
3808 * the cycle numbers agree with the current cycle number.
3809 */
3810STATIC void
3811xlog_verify_iclog(
3812 struct xlog *log,
3813 struct xlog_in_core *iclog,
3814 int count,
3815 bool syncing)
3816{
3817 xlog_op_header_t *ophead;
3818 xlog_in_core_t *icptr;
3819 xlog_in_core_2_t *xhdr;
3820 void *base_ptr, *ptr, *p;
3821 ptrdiff_t field_offset;
3822 uint8_t clientid;
3823 int len, i, j, k, op_len;
3824 int idx;
3825
3826 /* check validity of iclog pointers */
3827 spin_lock(&log->l_icloglock);
3828 icptr = log->l_iclog;
3829 for (i = 0; i < log->l_iclog_bufs; i++, icptr = icptr->ic_next)
3830 ASSERT(icptr);
3831
3832 if (icptr != log->l_iclog)
3833 xfs_emerg(log->l_mp, "%s: corrupt iclog ring", __func__);
3834 spin_unlock(&log->l_icloglock);
3835
3836 /* check log magic numbers */
3837 if (iclog->ic_header.h_magicno != cpu_to_be32(XLOG_HEADER_MAGIC_NUM))
3838 xfs_emerg(log->l_mp, "%s: invalid magic num", __func__);
3839
3840 base_ptr = ptr = &iclog->ic_header;
3841 p = &iclog->ic_header;
3842 for (ptr += BBSIZE; ptr < base_ptr + count; ptr += BBSIZE) {
3843 if (*(__be32 *)ptr == cpu_to_be32(XLOG_HEADER_MAGIC_NUM))
3844 xfs_emerg(log->l_mp, "%s: unexpected magic num",
3845 __func__);
3846 }
3847
3848 /* check fields */
3849 len = be32_to_cpu(iclog->ic_header.h_num_logops);
3850 base_ptr = ptr = iclog->ic_datap;
3851 ophead = ptr;
3852 xhdr = iclog->ic_data;
3853 for (i = 0; i < len; i++) {
3854 ophead = ptr;
3855
3856 /* clientid is only 1 byte */
3857 p = &ophead->oh_clientid;
3858 field_offset = p - base_ptr;
3859 if (!syncing || (field_offset & 0x1ff)) {
3860 clientid = ophead->oh_clientid;
3861 } else {
3862 idx = BTOBBT((char *)&ophead->oh_clientid - iclog->ic_datap);
3863 if (idx >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE)) {
3864 j = idx / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3865 k = idx % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3866 clientid = xlog_get_client_id(
3867 xhdr[j].hic_xheader.xh_cycle_data[k]);
3868 } else {
3869 clientid = xlog_get_client_id(
3870 iclog->ic_header.h_cycle_data[idx]);
3871 }
3872 }
3873 if (clientid != XFS_TRANSACTION && clientid != XFS_LOG)
3874 xfs_warn(log->l_mp,
3875 "%s: invalid clientid %d op "PTR_FMT" offset 0x%lx",
3876 __func__, clientid, ophead,
3877 (unsigned long)field_offset);
3878
3879 /* check length */
3880 p = &ophead->oh_len;
3881 field_offset = p - base_ptr;
3882 if (!syncing || (field_offset & 0x1ff)) {
3883 op_len = be32_to_cpu(ophead->oh_len);
3884 } else {
3885 idx = BTOBBT((uintptr_t)&ophead->oh_len -
3886 (uintptr_t)iclog->ic_datap);
3887 if (idx >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE)) {
3888 j = idx / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3889 k = idx % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3890 op_len = be32_to_cpu(xhdr[j].hic_xheader.xh_cycle_data[k]);
3891 } else {
3892 op_len = be32_to_cpu(iclog->ic_header.h_cycle_data[idx]);
3893 }
3894 }
3895 ptr += sizeof(xlog_op_header_t) + op_len;
3896 }
3897} /* xlog_verify_iclog */
3898#endif
3899
3900/*
3901 * Mark all iclogs IOERROR. l_icloglock is held by the caller.
3902 */
3903STATIC int
3904xlog_state_ioerror(
3905 struct xlog *log)
3906{
3907 xlog_in_core_t *iclog, *ic;
3908
3909 iclog = log->l_iclog;
3910 if (! (iclog->ic_state & XLOG_STATE_IOERROR)) {
3911 /*
3912 * Mark all the incore logs IOERROR.
3913 * From now on, no log flushes will result.
3914 */
3915 ic = iclog;
3916 do {
3917 ic->ic_state = XLOG_STATE_IOERROR;
3918 ic = ic->ic_next;
3919 } while (ic != iclog);
3920 return 0;
3921 }
3922 /*
3923 * Return non-zero, if state transition has already happened.
3924 */
3925 return 1;
3926}
3927
3928/*
3929 * This is called from xfs_force_shutdown, when we're forcibly
3930 * shutting down the filesystem, typically because of an IO error.
3931 * Our main objectives here are to make sure that:
3932 * a. if !logerror, flush the logs to disk. Anything modified
3933 * after this is ignored.
3934 * b. the filesystem gets marked 'SHUTDOWN' for all interested
3935 * parties to find out, 'atomically'.
3936 * c. those who're sleeping on log reservations, pinned objects and
3937 * other resources get woken up, and be told the bad news.
3938 * d. nothing new gets queued up after (b) and (c) are done.
3939 *
3940 * Note: for the !logerror case we need to flush the regions held in memory out
3941 * to disk first. This needs to be done before the log is marked as shutdown,
3942 * otherwise the iclog writes will fail.
3943 */
3944int
3945xfs_log_force_umount(
3946 struct xfs_mount *mp,
3947 int logerror)
3948{
3949 struct xlog *log;
3950 int retval;
3951
3952 log = mp->m_log;
3953
3954 /*
3955 * If this happens during log recovery, don't worry about
3956 * locking; the log isn't open for business yet.
3957 */
3958 if (!log ||
3959 log->l_flags & XLOG_ACTIVE_RECOVERY) {
3960 mp->m_flags |= XFS_MOUNT_FS_SHUTDOWN;
3961 if (mp->m_sb_bp)
3962 mp->m_sb_bp->b_flags |= XBF_DONE;
3963 return 0;
3964 }
3965
3966 /*
3967 * Somebody could've already done the hard work for us.
3968 * No need to get locks for this.
3969 */
3970 if (logerror && log->l_iclog->ic_state & XLOG_STATE_IOERROR) {
3971 ASSERT(XLOG_FORCED_SHUTDOWN(log));
3972 return 1;
3973 }
3974
3975 /*
3976 * Flush all the completed transactions to disk before marking the log
3977 * being shut down. We need to do it in this order to ensure that
3978 * completed operations are safely on disk before we shut down, and that
3979 * we don't have to issue any buffer IO after the shutdown flags are set
3980 * to guarantee this.
3981 */
3982 if (!logerror)
3983 xfs_log_force(mp, XFS_LOG_SYNC);
3984
3985 /*
3986 * mark the filesystem and the as in a shutdown state and wake
3987 * everybody up to tell them the bad news.
3988 */
3989 spin_lock(&log->l_icloglock);
3990 mp->m_flags |= XFS_MOUNT_FS_SHUTDOWN;
3991 if (mp->m_sb_bp)
3992 mp->m_sb_bp->b_flags |= XBF_DONE;
3993
3994 /*
3995 * Mark the log and the iclogs with IO error flags to prevent any
3996 * further log IO from being issued or completed.
3997 */
3998 log->l_flags |= XLOG_IO_ERROR;
3999 retval = xlog_state_ioerror(log);
4000 spin_unlock(&log->l_icloglock);
4001
4002 /*
4003 * We don't want anybody waiting for log reservations after this. That
4004 * means we have to wake up everybody queued up on reserveq as well as
4005 * writeq. In addition, we make sure in xlog_{re}grant_log_space that
4006 * we don't enqueue anything once the SHUTDOWN flag is set, and this
4007 * action is protected by the grant locks.
4008 */
4009 xlog_grant_head_wake_all(&log->l_reserve_head);
4010 xlog_grant_head_wake_all(&log->l_write_head);
4011
4012 /*
4013 * Wake up everybody waiting on xfs_log_force. Wake the CIL push first
4014 * as if the log writes were completed. The abort handling in the log
4015 * item committed callback functions will do this again under lock to
4016 * avoid races.
4017 */
4018 wake_up_all(&log->l_cilp->xc_commit_wait);
4019 xlog_state_do_callback(log, XFS_LI_ABORTED, NULL);
4020
4021#ifdef XFSERRORDEBUG
4022 {
4023 xlog_in_core_t *iclog;
4024
4025 spin_lock(&log->l_icloglock);
4026 iclog = log->l_iclog;
4027 do {
4028 ASSERT(iclog->ic_callback == 0);
4029 iclog = iclog->ic_next;
4030 } while (iclog != log->l_iclog);
4031 spin_unlock(&log->l_icloglock);
4032 }
4033#endif
4034 /* return non-zero if log IOERROR transition had already happened */
4035 return retval;
4036}
4037
4038STATIC int
4039xlog_iclogs_empty(
4040 struct xlog *log)
4041{
4042 xlog_in_core_t *iclog;
4043
4044 iclog = log->l_iclog;
4045 do {
4046 /* endianness does not matter here, zero is zero in
4047 * any language.
4048 */
4049 if (iclog->ic_header.h_num_logops)
4050 return 0;
4051 iclog = iclog->ic_next;
4052 } while (iclog != log->l_iclog);
4053 return 1;
4054}
4055
4056/*
4057 * Verify that an LSN stamped into a piece of metadata is valid. This is
4058 * intended for use in read verifiers on v5 superblocks.
4059 */
4060bool
4061xfs_log_check_lsn(
4062 struct xfs_mount *mp,
4063 xfs_lsn_t lsn)
4064{
4065 struct xlog *log = mp->m_log;
4066 bool valid;
4067
4068 /*
4069 * norecovery mode skips mount-time log processing and unconditionally
4070 * resets the in-core LSN. We can't validate in this mode, but
4071 * modifications are not allowed anyways so just return true.
4072 */
4073 if (mp->m_flags & XFS_MOUNT_NORECOVERY)
4074 return true;
4075
4076 /*
4077 * Some metadata LSNs are initialized to NULL (e.g., the agfl). This is
4078 * handled by recovery and thus safe to ignore here.
4079 */
4080 if (lsn == NULLCOMMITLSN)
4081 return true;
4082
4083 valid = xlog_valid_lsn(mp->m_log, lsn);
4084
4085 /* warn the user about what's gone wrong before verifier failure */
4086 if (!valid) {
4087 spin_lock(&log->l_icloglock);
4088 xfs_warn(mp,
4089"Corruption warning: Metadata has LSN (%d:%d) ahead of current LSN (%d:%d). "
4090"Please unmount and run xfs_repair (>= v4.3) to resolve.",
4091 CYCLE_LSN(lsn), BLOCK_LSN(lsn),
4092 log->l_curr_cycle, log->l_curr_block);
4093 spin_unlock(&log->l_icloglock);
4094 }
4095
4096 return valid;
4097}