Merge tag 'arm64-stable' of git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas...
[linux-2.6.git] / fs / xfs / xfs_log.c
blobd852a2b3e1fdfae0c4fb5bf18452ec79fd03ab01
1 /*
2 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
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.
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.
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
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 #include "xfs_fsops.h"
38 #include "xfs_cksum.h"
40 kmem_zone_t *xfs_log_ticket_zone;
42 /* Local miscellaneous function prototypes */
43 STATIC int
44 xlog_commit_record(
45 struct xlog *log,
46 struct xlog_ticket *ticket,
47 struct xlog_in_core **iclog,
48 xfs_lsn_t *commitlsnp);
50 STATIC struct xlog *
51 xlog_alloc_log(
52 struct xfs_mount *mp,
53 struct xfs_buftarg *log_target,
54 xfs_daddr_t blk_offset,
55 int num_bblks);
56 STATIC int
57 xlog_space_left(
58 struct xlog *log,
59 atomic64_t *head);
60 STATIC int
61 xlog_sync(
62 struct xlog *log,
63 struct xlog_in_core *iclog);
64 STATIC void
65 xlog_dealloc_log(
66 struct xlog *log);
68 /* local state machine functions */
69 STATIC void xlog_state_done_syncing(xlog_in_core_t *iclog, int);
70 STATIC void
71 xlog_state_do_callback(
72 struct xlog *log,
73 int aborted,
74 struct xlog_in_core *iclog);
75 STATIC int
76 xlog_state_get_iclog_space(
77 struct xlog *log,
78 int len,
79 struct xlog_in_core **iclog,
80 struct xlog_ticket *ticket,
81 int *continued_write,
82 int *logoffsetp);
83 STATIC int
84 xlog_state_release_iclog(
85 struct xlog *log,
86 struct xlog_in_core *iclog);
87 STATIC void
88 xlog_state_switch_iclogs(
89 struct xlog *log,
90 struct xlog_in_core *iclog,
91 int eventual_size);
92 STATIC void
93 xlog_state_want_sync(
94 struct xlog *log,
95 struct xlog_in_core *iclog);
97 STATIC void
98 xlog_grant_push_ail(
99 struct xlog *log,
100 int need_bytes);
101 STATIC void
102 xlog_regrant_reserve_log_space(
103 struct xlog *log,
104 struct xlog_ticket *ticket);
105 STATIC void
106 xlog_ungrant_log_space(
107 struct xlog *log,
108 struct xlog_ticket *ticket);
110 #if defined(DEBUG)
111 STATIC void
112 xlog_verify_dest_ptr(
113 struct xlog *log,
114 char *ptr);
115 STATIC void
116 xlog_verify_grant_tail(
117 struct xlog *log);
118 STATIC void
119 xlog_verify_iclog(
120 struct xlog *log,
121 struct xlog_in_core *iclog,
122 int count,
123 bool syncing);
124 STATIC void
125 xlog_verify_tail_lsn(
126 struct xlog *log,
127 struct xlog_in_core *iclog,
128 xfs_lsn_t tail_lsn);
129 #else
130 #define xlog_verify_dest_ptr(a,b)
131 #define xlog_verify_grant_tail(a)
132 #define xlog_verify_iclog(a,b,c,d)
133 #define xlog_verify_tail_lsn(a,b,c)
134 #endif
136 STATIC int
137 xlog_iclogs_empty(
138 struct xlog *log);
140 static void
141 xlog_grant_sub_space(
142 struct xlog *log,
143 atomic64_t *head,
144 int bytes)
146 int64_t head_val = atomic64_read(head);
147 int64_t new, old;
149 do {
150 int cycle, space;
152 xlog_crack_grant_head_val(head_val, &cycle, &space);
154 space -= bytes;
155 if (space < 0) {
156 space += log->l_logsize;
157 cycle--;
160 old = head_val;
161 new = xlog_assign_grant_head_val(cycle, space);
162 head_val = atomic64_cmpxchg(head, old, new);
163 } while (head_val != old);
166 static void
167 xlog_grant_add_space(
168 struct xlog *log,
169 atomic64_t *head,
170 int bytes)
172 int64_t head_val = atomic64_read(head);
173 int64_t new, old;
175 do {
176 int tmp;
177 int cycle, space;
179 xlog_crack_grant_head_val(head_val, &cycle, &space);
181 tmp = log->l_logsize - space;
182 if (tmp > bytes)
183 space += bytes;
184 else {
185 space = bytes - tmp;
186 cycle++;
189 old = head_val;
190 new = xlog_assign_grant_head_val(cycle, space);
191 head_val = atomic64_cmpxchg(head, old, new);
192 } while (head_val != old);
195 STATIC void
196 xlog_grant_head_init(
197 struct xlog_grant_head *head)
199 xlog_assign_grant_head(&head->grant, 1, 0);
200 INIT_LIST_HEAD(&head->waiters);
201 spin_lock_init(&head->lock);
204 STATIC void
205 xlog_grant_head_wake_all(
206 struct xlog_grant_head *head)
208 struct xlog_ticket *tic;
210 spin_lock(&head->lock);
211 list_for_each_entry(tic, &head->waiters, t_queue)
212 wake_up_process(tic->t_task);
213 spin_unlock(&head->lock);
216 static inline int
217 xlog_ticket_reservation(
218 struct xlog *log,
219 struct xlog_grant_head *head,
220 struct xlog_ticket *tic)
222 if (head == &log->l_write_head) {
223 ASSERT(tic->t_flags & XLOG_TIC_PERM_RESERV);
224 return tic->t_unit_res;
225 } else {
226 if (tic->t_flags & XLOG_TIC_PERM_RESERV)
227 return tic->t_unit_res * tic->t_cnt;
228 else
229 return tic->t_unit_res;
233 STATIC bool
234 xlog_grant_head_wake(
235 struct xlog *log,
236 struct xlog_grant_head *head,
237 int *free_bytes)
239 struct xlog_ticket *tic;
240 int need_bytes;
242 list_for_each_entry(tic, &head->waiters, t_queue) {
243 need_bytes = xlog_ticket_reservation(log, head, tic);
244 if (*free_bytes < need_bytes)
245 return false;
247 *free_bytes -= need_bytes;
248 trace_xfs_log_grant_wake_up(log, tic);
249 wake_up_process(tic->t_task);
252 return true;
255 STATIC int
256 xlog_grant_head_wait(
257 struct xlog *log,
258 struct xlog_grant_head *head,
259 struct xlog_ticket *tic,
260 int need_bytes)
262 list_add_tail(&tic->t_queue, &head->waiters);
264 do {
265 if (XLOG_FORCED_SHUTDOWN(log))
266 goto shutdown;
267 xlog_grant_push_ail(log, need_bytes);
269 __set_current_state(TASK_UNINTERRUPTIBLE);
270 spin_unlock(&head->lock);
272 XFS_STATS_INC(xs_sleep_logspace);
274 trace_xfs_log_grant_sleep(log, tic);
275 schedule();
276 trace_xfs_log_grant_wake(log, tic);
278 spin_lock(&head->lock);
279 if (XLOG_FORCED_SHUTDOWN(log))
280 goto shutdown;
281 } while (xlog_space_left(log, &head->grant) < need_bytes);
283 list_del_init(&tic->t_queue);
284 return 0;
285 shutdown:
286 list_del_init(&tic->t_queue);
287 return XFS_ERROR(EIO);
291 * Atomically get the log space required for a log ticket.
293 * Once a ticket gets put onto head->waiters, it will only return after the
294 * needed reservation is satisfied.
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.
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.
307 STATIC int
308 xlog_grant_head_check(
309 struct xlog *log,
310 struct xlog_grant_head *head,
311 struct xlog_ticket *tic,
312 int *need_bytes)
314 int free_bytes;
315 int error = 0;
317 ASSERT(!(log->l_flags & XLOG_ACTIVE_RECOVERY));
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.
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);
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);
341 return error;
344 static void
345 xlog_tic_reset_res(xlog_ticket_t *tic)
347 tic->t_res_num = 0;
348 tic->t_res_arr_sum = 0;
349 tic->t_res_num_ophdrs = 0;
352 static void
353 xlog_tic_add_region(xlog_ticket_t *tic, uint len, uint type)
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;
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++;
369 * Replenish the byte reservation required by moving the grant write head.
372 xfs_log_regrant(
373 struct xfs_mount *mp,
374 struct xlog_ticket *tic)
376 struct xlog *log = mp->m_log;
377 int need_bytes;
378 int error = 0;
380 if (XLOG_FORCED_SHUTDOWN(log))
381 return XFS_ERROR(EIO);
383 XFS_STATS_INC(xs_try_logspace);
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.
391 tic->t_tid++;
393 xlog_grant_push_ail(log, tic->t_unit_res);
395 tic->t_curr_res = tic->t_unit_res;
396 xlog_tic_reset_res(tic);
398 if (tic->t_cnt > 0)
399 return 0;
401 trace_xfs_log_regrant(log, tic);
403 error = xlog_grant_head_check(log, &log->l_write_head, tic,
404 &need_bytes);
405 if (error)
406 goto out_error;
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;
413 out_error:
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.
419 tic->t_curr_res = 0;
420 tic->t_cnt = 0; /* ungrant will give back unit_res * t_cnt. */
421 return error;
425 * Reserve log space and return a ticket corresponding the reservation.
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.
433 xfs_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 uint t_type)
442 struct xlog *log = mp->m_log;
443 struct xlog_ticket *tic;
444 int need_bytes;
445 int error = 0;
447 ASSERT(client == XFS_TRANSACTION || client == XFS_LOG);
449 if (XLOG_FORCED_SHUTDOWN(log))
450 return XFS_ERROR(EIO);
452 XFS_STATS_INC(xs_try_logspace);
454 ASSERT(*ticp == NULL);
455 tic = xlog_ticket_alloc(log, unit_bytes, cnt, client, permanent,
456 KM_SLEEP | KM_MAYFAIL);
457 if (!tic)
458 return XFS_ERROR(ENOMEM);
460 tic->t_trans_type = t_type;
461 *ticp = tic;
463 xlog_grant_push_ail(log, tic->t_cnt ? tic->t_unit_res * tic->t_cnt
464 : tic->t_unit_res);
466 trace_xfs_log_reserve(log, tic);
468 error = xlog_grant_head_check(log, &log->l_reserve_head, tic,
469 &need_bytes);
470 if (error)
471 goto out_error;
473 xlog_grant_add_space(log, &log->l_reserve_head.grant, need_bytes);
474 xlog_grant_add_space(log, &log->l_write_head.grant, need_bytes);
475 trace_xfs_log_reserve_exit(log, tic);
476 xlog_verify_grant_tail(log);
477 return 0;
479 out_error:
481 * If we are failing, make sure the ticket doesn't have any current
482 * reservations. We don't want to add this back when the ticket/
483 * transaction gets cancelled.
485 tic->t_curr_res = 0;
486 tic->t_cnt = 0; /* ungrant will give back unit_res * t_cnt. */
487 return error;
492 * NOTES:
494 * 1. currblock field gets updated at startup and after in-core logs
495 * marked as with WANT_SYNC.
499 * This routine is called when a user of a log manager ticket is done with
500 * the reservation. If the ticket was ever used, then a commit record for
501 * the associated transaction is written out as a log operation header with
502 * no data. The flag XLOG_TIC_INITED is set when the first write occurs with
503 * a given ticket. If the ticket was one with a permanent reservation, then
504 * a few operations are done differently. Permanent reservation tickets by
505 * default don't release the reservation. They just commit the current
506 * transaction with the belief that the reservation is still needed. A flag
507 * must be passed in before permanent reservations are actually released.
508 * When these type of tickets are not released, they need to be set into
509 * the inited state again. By doing this, a start record will be written
510 * out when the next write occurs.
512 xfs_lsn_t
513 xfs_log_done(
514 struct xfs_mount *mp,
515 struct xlog_ticket *ticket,
516 struct xlog_in_core **iclog,
517 uint flags)
519 struct xlog *log = mp->m_log;
520 xfs_lsn_t lsn = 0;
522 if (XLOG_FORCED_SHUTDOWN(log) ||
524 * If nothing was ever written, don't write out commit record.
525 * If we get an error, just continue and give back the log ticket.
527 (((ticket->t_flags & XLOG_TIC_INITED) == 0) &&
528 (xlog_commit_record(log, ticket, iclog, &lsn)))) {
529 lsn = (xfs_lsn_t) -1;
530 if (ticket->t_flags & XLOG_TIC_PERM_RESERV) {
531 flags |= XFS_LOG_REL_PERM_RESERV;
536 if ((ticket->t_flags & XLOG_TIC_PERM_RESERV) == 0 ||
537 (flags & XFS_LOG_REL_PERM_RESERV)) {
538 trace_xfs_log_done_nonperm(log, ticket);
541 * Release ticket if not permanent reservation or a specific
542 * request has been made to release a permanent reservation.
544 xlog_ungrant_log_space(log, ticket);
545 xfs_log_ticket_put(ticket);
546 } else {
547 trace_xfs_log_done_perm(log, ticket);
549 xlog_regrant_reserve_log_space(log, ticket);
550 /* If this ticket was a permanent reservation and we aren't
551 * trying to release it, reset the inited flags; so next time
552 * we write, a start record will be written out.
554 ticket->t_flags |= XLOG_TIC_INITED;
557 return lsn;
561 * Attaches a new iclog I/O completion callback routine during
562 * transaction commit. If the log is in error state, a non-zero
563 * return code is handed back and the caller is responsible for
564 * executing the callback at an appropriate time.
567 xfs_log_notify(
568 struct xfs_mount *mp,
569 struct xlog_in_core *iclog,
570 xfs_log_callback_t *cb)
572 int abortflg;
574 spin_lock(&iclog->ic_callback_lock);
575 abortflg = (iclog->ic_state & XLOG_STATE_IOERROR);
576 if (!abortflg) {
577 ASSERT_ALWAYS((iclog->ic_state == XLOG_STATE_ACTIVE) ||
578 (iclog->ic_state == XLOG_STATE_WANT_SYNC));
579 cb->cb_next = NULL;
580 *(iclog->ic_callback_tail) = cb;
581 iclog->ic_callback_tail = &(cb->cb_next);
583 spin_unlock(&iclog->ic_callback_lock);
584 return abortflg;
588 xfs_log_release_iclog(
589 struct xfs_mount *mp,
590 struct xlog_in_core *iclog)
592 if (xlog_state_release_iclog(mp->m_log, iclog)) {
593 xfs_force_shutdown(mp, SHUTDOWN_LOG_IO_ERROR);
594 return EIO;
597 return 0;
601 * Mount a log filesystem
603 * mp - ubiquitous xfs mount point structure
604 * log_target - buftarg of on-disk log device
605 * blk_offset - Start block # where block size is 512 bytes (BBSIZE)
606 * num_bblocks - Number of BBSIZE blocks in on-disk log
608 * Return error or zero.
611 xfs_log_mount(
612 xfs_mount_t *mp,
613 xfs_buftarg_t *log_target,
614 xfs_daddr_t blk_offset,
615 int num_bblks)
617 int error;
619 if (!(mp->m_flags & XFS_MOUNT_NORECOVERY))
620 xfs_notice(mp, "Mounting Filesystem");
621 else {
622 xfs_notice(mp,
623 "Mounting filesystem in no-recovery mode. Filesystem will be inconsistent.");
624 ASSERT(mp->m_flags & XFS_MOUNT_RDONLY);
627 mp->m_log = xlog_alloc_log(mp, log_target, blk_offset, num_bblks);
628 if (IS_ERR(mp->m_log)) {
629 error = -PTR_ERR(mp->m_log);
630 goto out;
634 * Initialize the AIL now we have a log.
636 error = xfs_trans_ail_init(mp);
637 if (error) {
638 xfs_warn(mp, "AIL initialisation failed: error %d", error);
639 goto out_free_log;
641 mp->m_log->l_ailp = mp->m_ail;
644 * skip log recovery on a norecovery mount. pretend it all
645 * just worked.
647 if (!(mp->m_flags & XFS_MOUNT_NORECOVERY)) {
648 int readonly = (mp->m_flags & XFS_MOUNT_RDONLY);
650 if (readonly)
651 mp->m_flags &= ~XFS_MOUNT_RDONLY;
653 error = xlog_recover(mp->m_log);
655 if (readonly)
656 mp->m_flags |= XFS_MOUNT_RDONLY;
657 if (error) {
658 xfs_warn(mp, "log mount/recovery failed: error %d",
659 error);
660 goto out_destroy_ail;
664 /* Normal transactions can now occur */
665 mp->m_log->l_flags &= ~XLOG_ACTIVE_RECOVERY;
668 * Now the log has been fully initialised and we know were our
669 * space grant counters are, we can initialise the permanent ticket
670 * needed for delayed logging to work.
672 xlog_cil_init_post_recovery(mp->m_log);
674 return 0;
676 out_destroy_ail:
677 xfs_trans_ail_destroy(mp);
678 out_free_log:
679 xlog_dealloc_log(mp->m_log);
680 out:
681 return error;
685 * Finish the recovery of the file system. This is separate from the
686 * xfs_log_mount() call, because it depends on the code in xfs_mountfs() to read
687 * in the root and real-time bitmap inodes between calling xfs_log_mount() and
688 * here.
690 * If we finish recovery successfully, start the background log work. If we are
691 * not doing recovery, then we have a RO filesystem and we don't need to start
692 * it.
695 xfs_log_mount_finish(xfs_mount_t *mp)
697 int error = 0;
699 if (!(mp->m_flags & XFS_MOUNT_NORECOVERY)) {
700 error = xlog_recover_finish(mp->m_log);
701 if (!error)
702 xfs_log_work_queue(mp);
703 } else {
704 ASSERT(mp->m_flags & XFS_MOUNT_RDONLY);
708 return error;
712 * Final log writes as part of unmount.
714 * Mark the filesystem clean as unmount happens. Note that during relocation
715 * this routine needs to be executed as part of source-bag while the
716 * deallocation must not be done until source-end.
720 * Unmount record used to have a string "Unmount filesystem--" in the
721 * data section where the "Un" was really a magic number (XLOG_UNMOUNT_TYPE).
722 * We just write the magic number now since that particular field isn't
723 * currently architecture converted and "nUmount" is a bit foo.
724 * As far as I know, there weren't any dependencies on the old behaviour.
728 xfs_log_unmount_write(xfs_mount_t *mp)
730 struct xlog *log = mp->m_log;
731 xlog_in_core_t *iclog;
732 #ifdef DEBUG
733 xlog_in_core_t *first_iclog;
734 #endif
735 xlog_ticket_t *tic = NULL;
736 xfs_lsn_t lsn;
737 int error;
740 * Don't write out unmount record on read-only mounts.
741 * Or, if we are doing a forced umount (typically because of IO errors).
743 if (mp->m_flags & XFS_MOUNT_RDONLY)
744 return 0;
746 error = _xfs_log_force(mp, XFS_LOG_SYNC, NULL);
747 ASSERT(error || !(XLOG_FORCED_SHUTDOWN(log)));
749 #ifdef DEBUG
750 first_iclog = iclog = log->l_iclog;
751 do {
752 if (!(iclog->ic_state & XLOG_STATE_IOERROR)) {
753 ASSERT(iclog->ic_state & XLOG_STATE_ACTIVE);
754 ASSERT(iclog->ic_offset == 0);
756 iclog = iclog->ic_next;
757 } while (iclog != first_iclog);
758 #endif
759 if (! (XLOG_FORCED_SHUTDOWN(log))) {
760 error = xfs_log_reserve(mp, 600, 1, &tic,
761 XFS_LOG, 0, XLOG_UNMOUNT_REC_TYPE);
762 if (!error) {
763 /* the data section must be 32 bit size aligned */
764 struct {
765 __uint16_t magic;
766 __uint16_t pad1;
767 __uint32_t pad2; /* may as well make it 64 bits */
768 } magic = {
769 .magic = XLOG_UNMOUNT_TYPE,
771 struct xfs_log_iovec reg = {
772 .i_addr = &magic,
773 .i_len = sizeof(magic),
774 .i_type = XLOG_REG_TYPE_UNMOUNT,
776 struct xfs_log_vec vec = {
777 .lv_niovecs = 1,
778 .lv_iovecp = &reg,
781 /* remove inited flag, and account for space used */
782 tic->t_flags = 0;
783 tic->t_curr_res -= sizeof(magic);
784 error = xlog_write(log, &vec, tic, &lsn,
785 NULL, XLOG_UNMOUNT_TRANS);
787 * At this point, we're umounting anyway,
788 * so there's no point in transitioning log state
789 * to IOERROR. Just continue...
793 if (error)
794 xfs_alert(mp, "%s: unmount record failed", __func__);
797 spin_lock(&log->l_icloglock);
798 iclog = log->l_iclog;
799 atomic_inc(&iclog->ic_refcnt);
800 xlog_state_want_sync(log, iclog);
801 spin_unlock(&log->l_icloglock);
802 error = xlog_state_release_iclog(log, iclog);
804 spin_lock(&log->l_icloglock);
805 if (!(iclog->ic_state == XLOG_STATE_ACTIVE ||
806 iclog->ic_state == XLOG_STATE_DIRTY)) {
807 if (!XLOG_FORCED_SHUTDOWN(log)) {
808 xlog_wait(&iclog->ic_force_wait,
809 &log->l_icloglock);
810 } else {
811 spin_unlock(&log->l_icloglock);
813 } else {
814 spin_unlock(&log->l_icloglock);
816 if (tic) {
817 trace_xfs_log_umount_write(log, tic);
818 xlog_ungrant_log_space(log, tic);
819 xfs_log_ticket_put(tic);
821 } else {
823 * We're already in forced_shutdown mode, couldn't
824 * even attempt to write out the unmount transaction.
826 * Go through the motions of sync'ing and releasing
827 * the iclog, even though no I/O will actually happen,
828 * we need to wait for other log I/Os that may already
829 * be in progress. Do this as a separate section of
830 * code so we'll know if we ever get stuck here that
831 * we're in this odd situation of trying to unmount
832 * a file system that went into forced_shutdown as
833 * the result of an unmount..
835 spin_lock(&log->l_icloglock);
836 iclog = log->l_iclog;
837 atomic_inc(&iclog->ic_refcnt);
839 xlog_state_want_sync(log, iclog);
840 spin_unlock(&log->l_icloglock);
841 error = xlog_state_release_iclog(log, iclog);
843 spin_lock(&log->l_icloglock);
845 if ( ! ( iclog->ic_state == XLOG_STATE_ACTIVE
846 || iclog->ic_state == XLOG_STATE_DIRTY
847 || iclog->ic_state == XLOG_STATE_IOERROR) ) {
849 xlog_wait(&iclog->ic_force_wait,
850 &log->l_icloglock);
851 } else {
852 spin_unlock(&log->l_icloglock);
856 return error;
857 } /* xfs_log_unmount_write */
860 * Empty the log for unmount/freeze.
862 * To do this, we first need to shut down the background log work so it is not
863 * trying to cover the log as we clean up. We then need to unpin all objects in
864 * the log so we can then flush them out. Once they have completed their IO and
865 * run the callbacks removing themselves from the AIL, we can write the unmount
866 * record.
868 void
869 xfs_log_quiesce(
870 struct xfs_mount *mp)
872 cancel_delayed_work_sync(&mp->m_log->l_work);
873 xfs_log_force(mp, XFS_LOG_SYNC);
876 * The superblock buffer is uncached and while xfs_ail_push_all_sync()
877 * will push it, xfs_wait_buftarg() will not wait for it. Further,
878 * xfs_buf_iowait() cannot be used because it was pushed with the
879 * XBF_ASYNC flag set, so we need to use a lock/unlock pair to wait for
880 * the IO to complete.
882 xfs_ail_push_all_sync(mp->m_ail);
883 xfs_wait_buftarg(mp->m_ddev_targp);
884 xfs_buf_lock(mp->m_sb_bp);
885 xfs_buf_unlock(mp->m_sb_bp);
887 xfs_log_unmount_write(mp);
891 * Shut down and release the AIL and Log.
893 * During unmount, we need to ensure we flush all the dirty metadata objects
894 * from the AIL so that the log is empty before we write the unmount record to
895 * the log. Once this is done, we can tear down the AIL and the log.
897 void
898 xfs_log_unmount(
899 struct xfs_mount *mp)
901 xfs_log_quiesce(mp);
903 xfs_trans_ail_destroy(mp);
904 xlog_dealloc_log(mp->m_log);
907 void
908 xfs_log_item_init(
909 struct xfs_mount *mp,
910 struct xfs_log_item *item,
911 int type,
912 const struct xfs_item_ops *ops)
914 item->li_mountp = mp;
915 item->li_ailp = mp->m_ail;
916 item->li_type = type;
917 item->li_ops = ops;
918 item->li_lv = NULL;
920 INIT_LIST_HEAD(&item->li_ail);
921 INIT_LIST_HEAD(&item->li_cil);
925 * Wake up processes waiting for log space after we have moved the log tail.
927 void
928 xfs_log_space_wake(
929 struct xfs_mount *mp)
931 struct xlog *log = mp->m_log;
932 int free_bytes;
934 if (XLOG_FORCED_SHUTDOWN(log))
935 return;
937 if (!list_empty_careful(&log->l_write_head.waiters)) {
938 ASSERT(!(log->l_flags & XLOG_ACTIVE_RECOVERY));
940 spin_lock(&log->l_write_head.lock);
941 free_bytes = xlog_space_left(log, &log->l_write_head.grant);
942 xlog_grant_head_wake(log, &log->l_write_head, &free_bytes);
943 spin_unlock(&log->l_write_head.lock);
946 if (!list_empty_careful(&log->l_reserve_head.waiters)) {
947 ASSERT(!(log->l_flags & XLOG_ACTIVE_RECOVERY));
949 spin_lock(&log->l_reserve_head.lock);
950 free_bytes = xlog_space_left(log, &log->l_reserve_head.grant);
951 xlog_grant_head_wake(log, &log->l_reserve_head, &free_bytes);
952 spin_unlock(&log->l_reserve_head.lock);
957 * Determine if we have a transaction that has gone to disk
958 * that needs to be covered. To begin the transition to the idle state
959 * firstly the log needs to be idle (no AIL and nothing in the iclogs).
960 * If we are then in a state where covering is needed, the caller is informed
961 * that dummy transactions are required to move the log into the idle state.
963 * Because this is called as part of the sync process, we should also indicate
964 * that dummy transactions should be issued in anything but the covered or
965 * idle states. This ensures that the log tail is accurately reflected in
966 * the log at the end of the sync, hence if a crash occurrs avoids replay
967 * of transactions where the metadata is already on disk.
970 xfs_log_need_covered(xfs_mount_t *mp)
972 int needed = 0;
973 struct xlog *log = mp->m_log;
975 if (!xfs_fs_writable(mp))
976 return 0;
978 spin_lock(&log->l_icloglock);
979 switch (log->l_covered_state) {
980 case XLOG_STATE_COVER_DONE:
981 case XLOG_STATE_COVER_DONE2:
982 case XLOG_STATE_COVER_IDLE:
983 break;
984 case XLOG_STATE_COVER_NEED:
985 case XLOG_STATE_COVER_NEED2:
986 if (!xfs_ail_min_lsn(log->l_ailp) &&
987 xlog_iclogs_empty(log)) {
988 if (log->l_covered_state == XLOG_STATE_COVER_NEED)
989 log->l_covered_state = XLOG_STATE_COVER_DONE;
990 else
991 log->l_covered_state = XLOG_STATE_COVER_DONE2;
993 /* FALLTHRU */
994 default:
995 needed = 1;
996 break;
998 spin_unlock(&log->l_icloglock);
999 return needed;
1003 * We may be holding the log iclog lock upon entering this routine.
1005 xfs_lsn_t
1006 xlog_assign_tail_lsn_locked(
1007 struct xfs_mount *mp)
1009 struct xlog *log = mp->m_log;
1010 struct xfs_log_item *lip;
1011 xfs_lsn_t tail_lsn;
1013 assert_spin_locked(&mp->m_ail->xa_lock);
1016 * To make sure we always have a valid LSN for the log tail we keep
1017 * track of the last LSN which was committed in log->l_last_sync_lsn,
1018 * and use that when the AIL was empty.
1020 lip = xfs_ail_min(mp->m_ail);
1021 if (lip)
1022 tail_lsn = lip->li_lsn;
1023 else
1024 tail_lsn = atomic64_read(&log->l_last_sync_lsn);
1025 atomic64_set(&log->l_tail_lsn, tail_lsn);
1026 return tail_lsn;
1029 xfs_lsn_t
1030 xlog_assign_tail_lsn(
1031 struct xfs_mount *mp)
1033 xfs_lsn_t tail_lsn;
1035 spin_lock(&mp->m_ail->xa_lock);
1036 tail_lsn = xlog_assign_tail_lsn_locked(mp);
1037 spin_unlock(&mp->m_ail->xa_lock);
1039 return tail_lsn;
1043 * Return the space in the log between the tail and the head. The head
1044 * is passed in the cycle/bytes formal parms. In the special case where
1045 * the reserve head has wrapped passed the tail, this calculation is no
1046 * longer valid. In this case, just return 0 which means there is no space
1047 * in the log. This works for all places where this function is called
1048 * with the reserve head. Of course, if the write head were to ever
1049 * wrap the tail, we should blow up. Rather than catch this case here,
1050 * we depend on other ASSERTions in other parts of the code. XXXmiken
1052 * This code also handles the case where the reservation head is behind
1053 * the tail. The details of this case are described below, but the end
1054 * result is that we return the size of the log as the amount of space left.
1056 STATIC int
1057 xlog_space_left(
1058 struct xlog *log,
1059 atomic64_t *head)
1061 int free_bytes;
1062 int tail_bytes;
1063 int tail_cycle;
1064 int head_cycle;
1065 int head_bytes;
1067 xlog_crack_grant_head(head, &head_cycle, &head_bytes);
1068 xlog_crack_atomic_lsn(&log->l_tail_lsn, &tail_cycle, &tail_bytes);
1069 tail_bytes = BBTOB(tail_bytes);
1070 if (tail_cycle == head_cycle && head_bytes >= tail_bytes)
1071 free_bytes = log->l_logsize - (head_bytes - tail_bytes);
1072 else if (tail_cycle + 1 < head_cycle)
1073 return 0;
1074 else if (tail_cycle < head_cycle) {
1075 ASSERT(tail_cycle == (head_cycle - 1));
1076 free_bytes = tail_bytes - head_bytes;
1077 } else {
1079 * The reservation head is behind the tail.
1080 * In this case we just want to return the size of the
1081 * log as the amount of space left.
1083 xfs_alert(log->l_mp,
1084 "xlog_space_left: head behind tail\n"
1085 " tail_cycle = %d, tail_bytes = %d\n"
1086 " GH cycle = %d, GH bytes = %d",
1087 tail_cycle, tail_bytes, head_cycle, head_bytes);
1088 ASSERT(0);
1089 free_bytes = log->l_logsize;
1091 return free_bytes;
1096 * Log function which is called when an io completes.
1098 * The log manager needs its own routine, in order to control what
1099 * happens with the buffer after the write completes.
1101 void
1102 xlog_iodone(xfs_buf_t *bp)
1104 struct xlog_in_core *iclog = bp->b_fspriv;
1105 struct xlog *l = iclog->ic_log;
1106 int aborted = 0;
1109 * Race to shutdown the filesystem if we see an error.
1111 if (XFS_TEST_ERROR((xfs_buf_geterror(bp)), l->l_mp,
1112 XFS_ERRTAG_IODONE_IOERR, XFS_RANDOM_IODONE_IOERR)) {
1113 xfs_buf_ioerror_alert(bp, __func__);
1114 xfs_buf_stale(bp);
1115 xfs_force_shutdown(l->l_mp, SHUTDOWN_LOG_IO_ERROR);
1117 * This flag will be propagated to the trans-committed
1118 * callback routines to let them know that the log-commit
1119 * didn't succeed.
1121 aborted = XFS_LI_ABORTED;
1122 } else if (iclog->ic_state & XLOG_STATE_IOERROR) {
1123 aborted = XFS_LI_ABORTED;
1126 /* log I/O is always issued ASYNC */
1127 ASSERT(XFS_BUF_ISASYNC(bp));
1128 xlog_state_done_syncing(iclog, aborted);
1130 * do not reference the buffer (bp) here as we could race
1131 * with it being freed after writing the unmount record to the
1132 * log.
1137 * Return size of each in-core log record buffer.
1139 * All machines get 8 x 32kB buffers by default, unless tuned otherwise.
1141 * If the filesystem blocksize is too large, we may need to choose a
1142 * larger size since the directory code currently logs entire blocks.
1145 STATIC void
1146 xlog_get_iclog_buffer_size(
1147 struct xfs_mount *mp,
1148 struct xlog *log)
1150 int size;
1151 int xhdrs;
1153 if (mp->m_logbufs <= 0)
1154 log->l_iclog_bufs = XLOG_MAX_ICLOGS;
1155 else
1156 log->l_iclog_bufs = mp->m_logbufs;
1159 * Buffer size passed in from mount system call.
1161 if (mp->m_logbsize > 0) {
1162 size = log->l_iclog_size = mp->m_logbsize;
1163 log->l_iclog_size_log = 0;
1164 while (size != 1) {
1165 log->l_iclog_size_log++;
1166 size >>= 1;
1169 if (xfs_sb_version_haslogv2(&mp->m_sb)) {
1170 /* # headers = size / 32k
1171 * one header holds cycles from 32k of data
1174 xhdrs = mp->m_logbsize / XLOG_HEADER_CYCLE_SIZE;
1175 if (mp->m_logbsize % XLOG_HEADER_CYCLE_SIZE)
1176 xhdrs++;
1177 log->l_iclog_hsize = xhdrs << BBSHIFT;
1178 log->l_iclog_heads = xhdrs;
1179 } else {
1180 ASSERT(mp->m_logbsize <= XLOG_BIG_RECORD_BSIZE);
1181 log->l_iclog_hsize = BBSIZE;
1182 log->l_iclog_heads = 1;
1184 goto done;
1187 /* All machines use 32kB buffers by default. */
1188 log->l_iclog_size = XLOG_BIG_RECORD_BSIZE;
1189 log->l_iclog_size_log = XLOG_BIG_RECORD_BSHIFT;
1191 /* the default log size is 16k or 32k which is one header sector */
1192 log->l_iclog_hsize = BBSIZE;
1193 log->l_iclog_heads = 1;
1195 done:
1196 /* are we being asked to make the sizes selected above visible? */
1197 if (mp->m_logbufs == 0)
1198 mp->m_logbufs = log->l_iclog_bufs;
1199 if (mp->m_logbsize == 0)
1200 mp->m_logbsize = log->l_iclog_size;
1201 } /* xlog_get_iclog_buffer_size */
1204 void
1205 xfs_log_work_queue(
1206 struct xfs_mount *mp)
1208 queue_delayed_work(mp->m_log_workqueue, &mp->m_log->l_work,
1209 msecs_to_jiffies(xfs_syncd_centisecs * 10));
1213 * Every sync period we need to unpin all items in the AIL and push them to
1214 * disk. If there is nothing dirty, then we might need to cover the log to
1215 * indicate that the filesystem is idle.
1217 void
1218 xfs_log_worker(
1219 struct work_struct *work)
1221 struct xlog *log = container_of(to_delayed_work(work),
1222 struct xlog, l_work);
1223 struct xfs_mount *mp = log->l_mp;
1225 /* dgc: errors ignored - not fatal and nowhere to report them */
1226 if (xfs_log_need_covered(mp))
1227 xfs_fs_log_dummy(mp);
1228 else
1229 xfs_log_force(mp, 0);
1231 /* start pushing all the metadata that is currently dirty */
1232 xfs_ail_push_all(mp->m_ail);
1234 /* queue us up again */
1235 xfs_log_work_queue(mp);
1239 * This routine initializes some of the log structure for a given mount point.
1240 * Its primary purpose is to fill in enough, so recovery can occur. However,
1241 * some other stuff may be filled in too.
1243 STATIC struct xlog *
1244 xlog_alloc_log(
1245 struct xfs_mount *mp,
1246 struct xfs_buftarg *log_target,
1247 xfs_daddr_t blk_offset,
1248 int num_bblks)
1250 struct xlog *log;
1251 xlog_rec_header_t *head;
1252 xlog_in_core_t **iclogp;
1253 xlog_in_core_t *iclog, *prev_iclog=NULL;
1254 xfs_buf_t *bp;
1255 int i;
1256 int error = ENOMEM;
1257 uint log2_size = 0;
1259 log = kmem_zalloc(sizeof(struct xlog), KM_MAYFAIL);
1260 if (!log) {
1261 xfs_warn(mp, "Log allocation failed: No memory!");
1262 goto out;
1265 log->l_mp = mp;
1266 log->l_targ = log_target;
1267 log->l_logsize = BBTOB(num_bblks);
1268 log->l_logBBstart = blk_offset;
1269 log->l_logBBsize = num_bblks;
1270 log->l_covered_state = XLOG_STATE_COVER_IDLE;
1271 log->l_flags |= XLOG_ACTIVE_RECOVERY;
1272 INIT_DELAYED_WORK(&log->l_work, xfs_log_worker);
1274 log->l_prev_block = -1;
1275 /* log->l_tail_lsn = 0x100000000LL; cycle = 1; current block = 0 */
1276 xlog_assign_atomic_lsn(&log->l_tail_lsn, 1, 0);
1277 xlog_assign_atomic_lsn(&log->l_last_sync_lsn, 1, 0);
1278 log->l_curr_cycle = 1; /* 0 is bad since this is initial value */
1280 xlog_grant_head_init(&log->l_reserve_head);
1281 xlog_grant_head_init(&log->l_write_head);
1283 error = EFSCORRUPTED;
1284 if (xfs_sb_version_hassector(&mp->m_sb)) {
1285 log2_size = mp->m_sb.sb_logsectlog;
1286 if (log2_size < BBSHIFT) {
1287 xfs_warn(mp, "Log sector size too small (0x%x < 0x%x)",
1288 log2_size, BBSHIFT);
1289 goto out_free_log;
1292 log2_size -= BBSHIFT;
1293 if (log2_size > mp->m_sectbb_log) {
1294 xfs_warn(mp, "Log sector size too large (0x%x > 0x%x)",
1295 log2_size, mp->m_sectbb_log);
1296 goto out_free_log;
1299 /* for larger sector sizes, must have v2 or external log */
1300 if (log2_size && log->l_logBBstart > 0 &&
1301 !xfs_sb_version_haslogv2(&mp->m_sb)) {
1302 xfs_warn(mp,
1303 "log sector size (0x%x) invalid for configuration.",
1304 log2_size);
1305 goto out_free_log;
1308 log->l_sectBBsize = 1 << log2_size;
1310 xlog_get_iclog_buffer_size(mp, log);
1312 error = ENOMEM;
1313 bp = xfs_buf_alloc(mp->m_logdev_targp, 0, BTOBB(log->l_iclog_size), 0);
1314 if (!bp)
1315 goto out_free_log;
1316 bp->b_iodone = xlog_iodone;
1317 ASSERT(xfs_buf_islocked(bp));
1318 log->l_xbuf = bp;
1320 spin_lock_init(&log->l_icloglock);
1321 init_waitqueue_head(&log->l_flush_wait);
1323 iclogp = &log->l_iclog;
1325 * The amount of memory to allocate for the iclog structure is
1326 * rather funky due to the way the structure is defined. It is
1327 * done this way so that we can use different sizes for machines
1328 * with different amounts of memory. See the definition of
1329 * xlog_in_core_t in xfs_log_priv.h for details.
1331 ASSERT(log->l_iclog_size >= 4096);
1332 for (i=0; i < log->l_iclog_bufs; i++) {
1333 *iclogp = kmem_zalloc(sizeof(xlog_in_core_t), KM_MAYFAIL);
1334 if (!*iclogp)
1335 goto out_free_iclog;
1337 iclog = *iclogp;
1338 iclog->ic_prev = prev_iclog;
1339 prev_iclog = iclog;
1341 bp = xfs_buf_get_uncached(mp->m_logdev_targp,
1342 BTOBB(log->l_iclog_size), 0);
1343 if (!bp)
1344 goto out_free_iclog;
1346 bp->b_iodone = xlog_iodone;
1347 iclog->ic_bp = bp;
1348 iclog->ic_data = bp->b_addr;
1349 #ifdef DEBUG
1350 log->l_iclog_bak[i] = (xfs_caddr_t)&(iclog->ic_header);
1351 #endif
1352 head = &iclog->ic_header;
1353 memset(head, 0, sizeof(xlog_rec_header_t));
1354 head->h_magicno = cpu_to_be32(XLOG_HEADER_MAGIC_NUM);
1355 head->h_version = cpu_to_be32(
1356 xfs_sb_version_haslogv2(&log->l_mp->m_sb) ? 2 : 1);
1357 head->h_size = cpu_to_be32(log->l_iclog_size);
1358 /* new fields */
1359 head->h_fmt = cpu_to_be32(XLOG_FMT);
1360 memcpy(&head->h_fs_uuid, &mp->m_sb.sb_uuid, sizeof(uuid_t));
1362 iclog->ic_size = BBTOB(bp->b_length) - log->l_iclog_hsize;
1363 iclog->ic_state = XLOG_STATE_ACTIVE;
1364 iclog->ic_log = log;
1365 atomic_set(&iclog->ic_refcnt, 0);
1366 spin_lock_init(&iclog->ic_callback_lock);
1367 iclog->ic_callback_tail = &(iclog->ic_callback);
1368 iclog->ic_datap = (char *)iclog->ic_data + log->l_iclog_hsize;
1370 ASSERT(xfs_buf_islocked(iclog->ic_bp));
1371 init_waitqueue_head(&iclog->ic_force_wait);
1372 init_waitqueue_head(&iclog->ic_write_wait);
1374 iclogp = &iclog->ic_next;
1376 *iclogp = log->l_iclog; /* complete ring */
1377 log->l_iclog->ic_prev = prev_iclog; /* re-write 1st prev ptr */
1379 error = xlog_cil_init(log);
1380 if (error)
1381 goto out_free_iclog;
1382 return log;
1384 out_free_iclog:
1385 for (iclog = log->l_iclog; iclog; iclog = prev_iclog) {
1386 prev_iclog = iclog->ic_next;
1387 if (iclog->ic_bp)
1388 xfs_buf_free(iclog->ic_bp);
1389 kmem_free(iclog);
1391 spinlock_destroy(&log->l_icloglock);
1392 xfs_buf_free(log->l_xbuf);
1393 out_free_log:
1394 kmem_free(log);
1395 out:
1396 return ERR_PTR(-error);
1397 } /* xlog_alloc_log */
1401 * Write out the commit record of a transaction associated with the given
1402 * ticket. Return the lsn of the commit record.
1404 STATIC int
1405 xlog_commit_record(
1406 struct xlog *log,
1407 struct xlog_ticket *ticket,
1408 struct xlog_in_core **iclog,
1409 xfs_lsn_t *commitlsnp)
1411 struct xfs_mount *mp = log->l_mp;
1412 int error;
1413 struct xfs_log_iovec reg = {
1414 .i_addr = NULL,
1415 .i_len = 0,
1416 .i_type = XLOG_REG_TYPE_COMMIT,
1418 struct xfs_log_vec vec = {
1419 .lv_niovecs = 1,
1420 .lv_iovecp = &reg,
1423 ASSERT_ALWAYS(iclog);
1424 error = xlog_write(log, &vec, ticket, commitlsnp, iclog,
1425 XLOG_COMMIT_TRANS);
1426 if (error)
1427 xfs_force_shutdown(mp, SHUTDOWN_LOG_IO_ERROR);
1428 return error;
1432 * Push on the buffer cache code if we ever use more than 75% of the on-disk
1433 * log space. This code pushes on the lsn which would supposedly free up
1434 * the 25% which we want to leave free. We may need to adopt a policy which
1435 * pushes on an lsn which is further along in the log once we reach the high
1436 * water mark. In this manner, we would be creating a low water mark.
1438 STATIC void
1439 xlog_grant_push_ail(
1440 struct xlog *log,
1441 int need_bytes)
1443 xfs_lsn_t threshold_lsn = 0;
1444 xfs_lsn_t last_sync_lsn;
1445 int free_blocks;
1446 int free_bytes;
1447 int threshold_block;
1448 int threshold_cycle;
1449 int free_threshold;
1451 ASSERT(BTOBB(need_bytes) < log->l_logBBsize);
1453 free_bytes = xlog_space_left(log, &log->l_reserve_head.grant);
1454 free_blocks = BTOBBT(free_bytes);
1457 * Set the threshold for the minimum number of free blocks in the
1458 * log to the maximum of what the caller needs, one quarter of the
1459 * log, and 256 blocks.
1461 free_threshold = BTOBB(need_bytes);
1462 free_threshold = MAX(free_threshold, (log->l_logBBsize >> 2));
1463 free_threshold = MAX(free_threshold, 256);
1464 if (free_blocks >= free_threshold)
1465 return;
1467 xlog_crack_atomic_lsn(&log->l_tail_lsn, &threshold_cycle,
1468 &threshold_block);
1469 threshold_block += free_threshold;
1470 if (threshold_block >= log->l_logBBsize) {
1471 threshold_block -= log->l_logBBsize;
1472 threshold_cycle += 1;
1474 threshold_lsn = xlog_assign_lsn(threshold_cycle,
1475 threshold_block);
1477 * Don't pass in an lsn greater than the lsn of the last
1478 * log record known to be on disk. Use a snapshot of the last sync lsn
1479 * so that it doesn't change between the compare and the set.
1481 last_sync_lsn = atomic64_read(&log->l_last_sync_lsn);
1482 if (XFS_LSN_CMP(threshold_lsn, last_sync_lsn) > 0)
1483 threshold_lsn = last_sync_lsn;
1486 * Get the transaction layer to kick the dirty buffers out to
1487 * disk asynchronously. No point in trying to do this if
1488 * the filesystem is shutting down.
1490 if (!XLOG_FORCED_SHUTDOWN(log))
1491 xfs_ail_push(log->l_ailp, threshold_lsn);
1495 * Stamp cycle number in every block
1497 STATIC void
1498 xlog_pack_data(
1499 struct xlog *log,
1500 struct xlog_in_core *iclog,
1501 int roundoff)
1503 int i, j, k;
1504 int size = iclog->ic_offset + roundoff;
1505 __be32 cycle_lsn;
1506 xfs_caddr_t dp;
1508 cycle_lsn = CYCLE_LSN_DISK(iclog->ic_header.h_lsn);
1510 dp = iclog->ic_datap;
1511 for (i = 0; i < BTOBB(size); i++) {
1512 if (i >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE))
1513 break;
1514 iclog->ic_header.h_cycle_data[i] = *(__be32 *)dp;
1515 *(__be32 *)dp = cycle_lsn;
1516 dp += BBSIZE;
1519 if (xfs_sb_version_haslogv2(&log->l_mp->m_sb)) {
1520 xlog_in_core_2_t *xhdr = iclog->ic_data;
1522 for ( ; i < BTOBB(size); i++) {
1523 j = i / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
1524 k = i % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
1525 xhdr[j].hic_xheader.xh_cycle_data[k] = *(__be32 *)dp;
1526 *(__be32 *)dp = cycle_lsn;
1527 dp += BBSIZE;
1530 for (i = 1; i < log->l_iclog_heads; i++)
1531 xhdr[i].hic_xheader.xh_cycle = cycle_lsn;
1536 * Calculate the checksum for a log buffer.
1538 * This is a little more complicated than it should be because the various
1539 * headers and the actual data are non-contiguous.
1541 __le32
1542 xlog_cksum(
1543 struct xlog *log,
1544 struct xlog_rec_header *rhead,
1545 char *dp,
1546 int size)
1548 __uint32_t crc;
1550 /* first generate the crc for the record header ... */
1551 crc = xfs_start_cksum((char *)rhead,
1552 sizeof(struct xlog_rec_header),
1553 offsetof(struct xlog_rec_header, h_crc));
1555 /* ... then for additional cycle data for v2 logs ... */
1556 if (xfs_sb_version_haslogv2(&log->l_mp->m_sb)) {
1557 union xlog_in_core2 *xhdr = (union xlog_in_core2 *)rhead;
1558 int i;
1560 for (i = 1; i < log->l_iclog_heads; i++) {
1561 crc = crc32c(crc, &xhdr[i].hic_xheader,
1562 sizeof(struct xlog_rec_ext_header));
1566 /* ... and finally for the payload */
1567 crc = crc32c(crc, dp, size);
1569 return xfs_end_cksum(crc);
1573 * The bdstrat callback function for log bufs. This gives us a central
1574 * place to trap bufs in case we get hit by a log I/O error and need to
1575 * shutdown. Actually, in practice, even when we didn't get a log error,
1576 * we transition the iclogs to IOERROR state *after* flushing all existing
1577 * iclogs to disk. This is because we don't want anymore new transactions to be
1578 * started or completed afterwards.
1580 STATIC int
1581 xlog_bdstrat(
1582 struct xfs_buf *bp)
1584 struct xlog_in_core *iclog = bp->b_fspriv;
1586 if (iclog->ic_state & XLOG_STATE_IOERROR) {
1587 xfs_buf_ioerror(bp, EIO);
1588 xfs_buf_stale(bp);
1589 xfs_buf_ioend(bp, 0);
1591 * It would seem logical to return EIO here, but we rely on
1592 * the log state machine to propagate I/O errors instead of
1593 * doing it here.
1595 return 0;
1598 xfs_buf_iorequest(bp);
1599 return 0;
1603 * Flush out the in-core log (iclog) to the on-disk log in an asynchronous
1604 * fashion. Previously, we should have moved the current iclog
1605 * ptr in the log to point to the next available iclog. This allows further
1606 * write to continue while this code syncs out an iclog ready to go.
1607 * Before an in-core log can be written out, the data section must be scanned
1608 * to save away the 1st word of each BBSIZE block into the header. We replace
1609 * it with the current cycle count. Each BBSIZE block is tagged with the
1610 * cycle count because there in an implicit assumption that drives will
1611 * guarantee that entire 512 byte blocks get written at once. In other words,
1612 * we can't have part of a 512 byte block written and part not written. By
1613 * tagging each block, we will know which blocks are valid when recovering
1614 * after an unclean shutdown.
1616 * This routine is single threaded on the iclog. No other thread can be in
1617 * this routine with the same iclog. Changing contents of iclog can there-
1618 * fore be done without grabbing the state machine lock. Updating the global
1619 * log will require grabbing the lock though.
1621 * The entire log manager uses a logical block numbering scheme. Only
1622 * log_sync (and then only bwrite()) know about the fact that the log may
1623 * not start with block zero on a given device. The log block start offset
1624 * is added immediately before calling bwrite().
1627 STATIC int
1628 xlog_sync(
1629 struct xlog *log,
1630 struct xlog_in_core *iclog)
1632 xfs_buf_t *bp;
1633 int i;
1634 uint count; /* byte count of bwrite */
1635 uint count_init; /* initial count before roundup */
1636 int roundoff; /* roundoff to BB or stripe */
1637 int split = 0; /* split write into two regions */
1638 int error;
1639 int v2 = xfs_sb_version_haslogv2(&log->l_mp->m_sb);
1640 int size;
1642 XFS_STATS_INC(xs_log_writes);
1643 ASSERT(atomic_read(&iclog->ic_refcnt) == 0);
1645 /* Add for LR header */
1646 count_init = log->l_iclog_hsize + iclog->ic_offset;
1648 /* Round out the log write size */
1649 if (v2 && log->l_mp->m_sb.sb_logsunit > 1) {
1650 /* we have a v2 stripe unit to use */
1651 count = XLOG_LSUNITTOB(log, XLOG_BTOLSUNIT(log, count_init));
1652 } else {
1653 count = BBTOB(BTOBB(count_init));
1655 roundoff = count - count_init;
1656 ASSERT(roundoff >= 0);
1657 ASSERT((v2 && log->l_mp->m_sb.sb_logsunit > 1 &&
1658 roundoff < log->l_mp->m_sb.sb_logsunit)
1660 (log->l_mp->m_sb.sb_logsunit <= 1 &&
1661 roundoff < BBTOB(1)));
1663 /* move grant heads by roundoff in sync */
1664 xlog_grant_add_space(log, &log->l_reserve_head.grant, roundoff);
1665 xlog_grant_add_space(log, &log->l_write_head.grant, roundoff);
1667 /* put cycle number in every block */
1668 xlog_pack_data(log, iclog, roundoff);
1670 /* real byte length */
1671 size = iclog->ic_offset;
1672 if (v2)
1673 size += roundoff;
1674 iclog->ic_header.h_len = cpu_to_be32(size);
1676 bp = iclog->ic_bp;
1677 XFS_BUF_SET_ADDR(bp, BLOCK_LSN(be64_to_cpu(iclog->ic_header.h_lsn)));
1679 XFS_STATS_ADD(xs_log_blocks, BTOBB(count));
1681 /* Do we need to split this write into 2 parts? */
1682 if (XFS_BUF_ADDR(bp) + BTOBB(count) > log->l_logBBsize) {
1683 char *dptr;
1685 split = count - (BBTOB(log->l_logBBsize - XFS_BUF_ADDR(bp)));
1686 count = BBTOB(log->l_logBBsize - XFS_BUF_ADDR(bp));
1687 iclog->ic_bwritecnt = 2;
1690 * Bump the cycle numbers at the start of each block in the
1691 * part of the iclog that ends up in the buffer that gets
1692 * written to the start of the log.
1694 * Watch out for the header magic number case, though.
1696 dptr = (char *)&iclog->ic_header + count;
1697 for (i = 0; i < split; i += BBSIZE) {
1698 __uint32_t cycle = be32_to_cpu(*(__be32 *)dptr);
1699 if (++cycle == XLOG_HEADER_MAGIC_NUM)
1700 cycle++;
1701 *(__be32 *)dptr = cpu_to_be32(cycle);
1703 dptr += BBSIZE;
1705 } else {
1706 iclog->ic_bwritecnt = 1;
1709 /* calculcate the checksum */
1710 iclog->ic_header.h_crc = xlog_cksum(log, &iclog->ic_header,
1711 iclog->ic_datap, size);
1713 bp->b_io_length = BTOBB(count);
1714 bp->b_fspriv = iclog;
1715 XFS_BUF_ZEROFLAGS(bp);
1716 XFS_BUF_ASYNC(bp);
1717 bp->b_flags |= XBF_SYNCIO;
1719 if (log->l_mp->m_flags & XFS_MOUNT_BARRIER) {
1720 bp->b_flags |= XBF_FUA;
1723 * Flush the data device before flushing the log to make
1724 * sure all meta data written back from the AIL actually made
1725 * it to disk before stamping the new log tail LSN into the
1726 * log buffer. For an external log we need to issue the
1727 * flush explicitly, and unfortunately synchronously here;
1728 * for an internal log we can simply use the block layer
1729 * state machine for preflushes.
1731 if (log->l_mp->m_logdev_targp != log->l_mp->m_ddev_targp)
1732 xfs_blkdev_issue_flush(log->l_mp->m_ddev_targp);
1733 else
1734 bp->b_flags |= XBF_FLUSH;
1737 ASSERT(XFS_BUF_ADDR(bp) <= log->l_logBBsize-1);
1738 ASSERT(XFS_BUF_ADDR(bp) + BTOBB(count) <= log->l_logBBsize);
1740 xlog_verify_iclog(log, iclog, count, true);
1742 /* account for log which doesn't start at block #0 */
1743 XFS_BUF_SET_ADDR(bp, XFS_BUF_ADDR(bp) + log->l_logBBstart);
1745 * Don't call xfs_bwrite here. We do log-syncs even when the filesystem
1746 * is shutting down.
1748 XFS_BUF_WRITE(bp);
1750 error = xlog_bdstrat(bp);
1751 if (error) {
1752 xfs_buf_ioerror_alert(bp, "xlog_sync");
1753 return error;
1755 if (split) {
1756 bp = iclog->ic_log->l_xbuf;
1757 XFS_BUF_SET_ADDR(bp, 0); /* logical 0 */
1758 xfs_buf_associate_memory(bp,
1759 (char *)&iclog->ic_header + count, split);
1760 bp->b_fspriv = iclog;
1761 XFS_BUF_ZEROFLAGS(bp);
1762 XFS_BUF_ASYNC(bp);
1763 bp->b_flags |= XBF_SYNCIO;
1764 if (log->l_mp->m_flags & XFS_MOUNT_BARRIER)
1765 bp->b_flags |= XBF_FUA;
1767 ASSERT(XFS_BUF_ADDR(bp) <= log->l_logBBsize-1);
1768 ASSERT(XFS_BUF_ADDR(bp) + BTOBB(count) <= log->l_logBBsize);
1770 /* account for internal log which doesn't start at block #0 */
1771 XFS_BUF_SET_ADDR(bp, XFS_BUF_ADDR(bp) + log->l_logBBstart);
1772 XFS_BUF_WRITE(bp);
1773 error = xlog_bdstrat(bp);
1774 if (error) {
1775 xfs_buf_ioerror_alert(bp, "xlog_sync (split)");
1776 return error;
1779 return 0;
1780 } /* xlog_sync */
1783 * Deallocate a log structure
1785 STATIC void
1786 xlog_dealloc_log(
1787 struct xlog *log)
1789 xlog_in_core_t *iclog, *next_iclog;
1790 int i;
1792 xlog_cil_destroy(log);
1795 * always need to ensure that the extra buffer does not point to memory
1796 * owned by another log buffer before we free it.
1798 xfs_buf_set_empty(log->l_xbuf, BTOBB(log->l_iclog_size));
1799 xfs_buf_free(log->l_xbuf);
1801 iclog = log->l_iclog;
1802 for (i=0; i<log->l_iclog_bufs; i++) {
1803 xfs_buf_free(iclog->ic_bp);
1804 next_iclog = iclog->ic_next;
1805 kmem_free(iclog);
1806 iclog = next_iclog;
1808 spinlock_destroy(&log->l_icloglock);
1810 log->l_mp->m_log = NULL;
1811 kmem_free(log);
1812 } /* xlog_dealloc_log */
1815 * Update counters atomically now that memcpy is done.
1817 /* ARGSUSED */
1818 static inline void
1819 xlog_state_finish_copy(
1820 struct xlog *log,
1821 struct xlog_in_core *iclog,
1822 int record_cnt,
1823 int copy_bytes)
1825 spin_lock(&log->l_icloglock);
1827 be32_add_cpu(&iclog->ic_header.h_num_logops, record_cnt);
1828 iclog->ic_offset += copy_bytes;
1830 spin_unlock(&log->l_icloglock);
1831 } /* xlog_state_finish_copy */
1837 * print out info relating to regions written which consume
1838 * the reservation
1840 void
1841 xlog_print_tic_res(
1842 struct xfs_mount *mp,
1843 struct xlog_ticket *ticket)
1845 uint i;
1846 uint ophdr_spc = ticket->t_res_num_ophdrs * (uint)sizeof(xlog_op_header_t);
1848 /* match with XLOG_REG_TYPE_* in xfs_log.h */
1849 static char *res_type_str[XLOG_REG_TYPE_MAX] = {
1850 "bformat",
1851 "bchunk",
1852 "efi_format",
1853 "efd_format",
1854 "iformat",
1855 "icore",
1856 "iext",
1857 "ibroot",
1858 "ilocal",
1859 "iattr_ext",
1860 "iattr_broot",
1861 "iattr_local",
1862 "qformat",
1863 "dquot",
1864 "quotaoff",
1865 "LR header",
1866 "unmount",
1867 "commit",
1868 "trans header"
1870 static char *trans_type_str[XFS_TRANS_TYPE_MAX] = {
1871 "SETATTR_NOT_SIZE",
1872 "SETATTR_SIZE",
1873 "INACTIVE",
1874 "CREATE",
1875 "CREATE_TRUNC",
1876 "TRUNCATE_FILE",
1877 "REMOVE",
1878 "LINK",
1879 "RENAME",
1880 "MKDIR",
1881 "RMDIR",
1882 "SYMLINK",
1883 "SET_DMATTRS",
1884 "GROWFS",
1885 "STRAT_WRITE",
1886 "DIOSTRAT",
1887 "WRITE_SYNC",
1888 "WRITEID",
1889 "ADDAFORK",
1890 "ATTRINVAL",
1891 "ATRUNCATE",
1892 "ATTR_SET",
1893 "ATTR_RM",
1894 "ATTR_FLAG",
1895 "CLEAR_AGI_BUCKET",
1896 "QM_SBCHANGE",
1897 "DUMMY1",
1898 "DUMMY2",
1899 "QM_QUOTAOFF",
1900 "QM_DQALLOC",
1901 "QM_SETQLIM",
1902 "QM_DQCLUSTER",
1903 "QM_QINOCREATE",
1904 "QM_QUOTAOFF_END",
1905 "SB_UNIT",
1906 "FSYNC_TS",
1907 "GROWFSRT_ALLOC",
1908 "GROWFSRT_ZERO",
1909 "GROWFSRT_FREE",
1910 "SWAPEXT"
1913 xfs_warn(mp,
1914 "xlog_write: reservation summary:\n"
1915 " trans type = %s (%u)\n"
1916 " unit res = %d bytes\n"
1917 " current res = %d bytes\n"
1918 " total reg = %u bytes (o/flow = %u bytes)\n"
1919 " ophdrs = %u (ophdr space = %u bytes)\n"
1920 " ophdr + reg = %u bytes\n"
1921 " num regions = %u\n",
1922 ((ticket->t_trans_type <= 0 ||
1923 ticket->t_trans_type > XFS_TRANS_TYPE_MAX) ?
1924 "bad-trans-type" : trans_type_str[ticket->t_trans_type-1]),
1925 ticket->t_trans_type,
1926 ticket->t_unit_res,
1927 ticket->t_curr_res,
1928 ticket->t_res_arr_sum, ticket->t_res_o_flow,
1929 ticket->t_res_num_ophdrs, ophdr_spc,
1930 ticket->t_res_arr_sum +
1931 ticket->t_res_o_flow + ophdr_spc,
1932 ticket->t_res_num);
1934 for (i = 0; i < ticket->t_res_num; i++) {
1935 uint r_type = ticket->t_res_arr[i].r_type;
1936 xfs_warn(mp, "region[%u]: %s - %u bytes\n", i,
1937 ((r_type <= 0 || r_type > XLOG_REG_TYPE_MAX) ?
1938 "bad-rtype" : res_type_str[r_type-1]),
1939 ticket->t_res_arr[i].r_len);
1942 xfs_alert_tag(mp, XFS_PTAG_LOGRES,
1943 "xlog_write: reservation ran out. Need to up reservation");
1944 xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
1948 * Calculate the potential space needed by the log vector. Each region gets
1949 * its own xlog_op_header_t and may need to be double word aligned.
1951 static int
1952 xlog_write_calc_vec_length(
1953 struct xlog_ticket *ticket,
1954 struct xfs_log_vec *log_vector)
1956 struct xfs_log_vec *lv;
1957 int headers = 0;
1958 int len = 0;
1959 int i;
1961 /* acct for start rec of xact */
1962 if (ticket->t_flags & XLOG_TIC_INITED)
1963 headers++;
1965 for (lv = log_vector; lv; lv = lv->lv_next) {
1966 /* we don't write ordered log vectors */
1967 if (lv->lv_buf_len == XFS_LOG_VEC_ORDERED)
1968 continue;
1970 headers += lv->lv_niovecs;
1972 for (i = 0; i < lv->lv_niovecs; i++) {
1973 struct xfs_log_iovec *vecp = &lv->lv_iovecp[i];
1975 len += vecp->i_len;
1976 xlog_tic_add_region(ticket, vecp->i_len, vecp->i_type);
1980 ticket->t_res_num_ophdrs += headers;
1981 len += headers * sizeof(struct xlog_op_header);
1983 return len;
1987 * If first write for transaction, insert start record We can't be trying to
1988 * commit if we are inited. We can't have any "partial_copy" if we are inited.
1990 static int
1991 xlog_write_start_rec(
1992 struct xlog_op_header *ophdr,
1993 struct xlog_ticket *ticket)
1995 if (!(ticket->t_flags & XLOG_TIC_INITED))
1996 return 0;
1998 ophdr->oh_tid = cpu_to_be32(ticket->t_tid);
1999 ophdr->oh_clientid = ticket->t_clientid;
2000 ophdr->oh_len = 0;
2001 ophdr->oh_flags = XLOG_START_TRANS;
2002 ophdr->oh_res2 = 0;
2004 ticket->t_flags &= ~XLOG_TIC_INITED;
2006 return sizeof(struct xlog_op_header);
2009 static xlog_op_header_t *
2010 xlog_write_setup_ophdr(
2011 struct xlog *log,
2012 struct xlog_op_header *ophdr,
2013 struct xlog_ticket *ticket,
2014 uint flags)
2016 ophdr->oh_tid = cpu_to_be32(ticket->t_tid);
2017 ophdr->oh_clientid = ticket->t_clientid;
2018 ophdr->oh_res2 = 0;
2020 /* are we copying a commit or unmount record? */
2021 ophdr->oh_flags = flags;
2024 * We've seen logs corrupted with bad transaction client ids. This
2025 * makes sure that XFS doesn't generate them on. Turn this into an EIO
2026 * and shut down the filesystem.
2028 switch (ophdr->oh_clientid) {
2029 case XFS_TRANSACTION:
2030 case XFS_VOLUME:
2031 case XFS_LOG:
2032 break;
2033 default:
2034 xfs_warn(log->l_mp,
2035 "Bad XFS transaction clientid 0x%x in ticket 0x%p",
2036 ophdr->oh_clientid, ticket);
2037 return NULL;
2040 return ophdr;
2044 * Set up the parameters of the region copy into the log. This has
2045 * to handle region write split across multiple log buffers - this
2046 * state is kept external to this function so that this code can
2047 * can be written in an obvious, self documenting manner.
2049 static int
2050 xlog_write_setup_copy(
2051 struct xlog_ticket *ticket,
2052 struct xlog_op_header *ophdr,
2053 int space_available,
2054 int space_required,
2055 int *copy_off,
2056 int *copy_len,
2057 int *last_was_partial_copy,
2058 int *bytes_consumed)
2060 int still_to_copy;
2062 still_to_copy = space_required - *bytes_consumed;
2063 *copy_off = *bytes_consumed;
2065 if (still_to_copy <= space_available) {
2066 /* write of region completes here */
2067 *copy_len = still_to_copy;
2068 ophdr->oh_len = cpu_to_be32(*copy_len);
2069 if (*last_was_partial_copy)
2070 ophdr->oh_flags |= (XLOG_END_TRANS|XLOG_WAS_CONT_TRANS);
2071 *last_was_partial_copy = 0;
2072 *bytes_consumed = 0;
2073 return 0;
2076 /* partial write of region, needs extra log op header reservation */
2077 *copy_len = space_available;
2078 ophdr->oh_len = cpu_to_be32(*copy_len);
2079 ophdr->oh_flags |= XLOG_CONTINUE_TRANS;
2080 if (*last_was_partial_copy)
2081 ophdr->oh_flags |= XLOG_WAS_CONT_TRANS;
2082 *bytes_consumed += *copy_len;
2083 (*last_was_partial_copy)++;
2085 /* account for new log op header */
2086 ticket->t_curr_res -= sizeof(struct xlog_op_header);
2087 ticket->t_res_num_ophdrs++;
2089 return sizeof(struct xlog_op_header);
2092 static int
2093 xlog_write_copy_finish(
2094 struct xlog *log,
2095 struct xlog_in_core *iclog,
2096 uint flags,
2097 int *record_cnt,
2098 int *data_cnt,
2099 int *partial_copy,
2100 int *partial_copy_len,
2101 int log_offset,
2102 struct xlog_in_core **commit_iclog)
2104 if (*partial_copy) {
2106 * This iclog has already been marked WANT_SYNC by
2107 * xlog_state_get_iclog_space.
2109 xlog_state_finish_copy(log, iclog, *record_cnt, *data_cnt);
2110 *record_cnt = 0;
2111 *data_cnt = 0;
2112 return xlog_state_release_iclog(log, iclog);
2115 *partial_copy = 0;
2116 *partial_copy_len = 0;
2118 if (iclog->ic_size - log_offset <= sizeof(xlog_op_header_t)) {
2119 /* no more space in this iclog - push it. */
2120 xlog_state_finish_copy(log, iclog, *record_cnt, *data_cnt);
2121 *record_cnt = 0;
2122 *data_cnt = 0;
2124 spin_lock(&log->l_icloglock);
2125 xlog_state_want_sync(log, iclog);
2126 spin_unlock(&log->l_icloglock);
2128 if (!commit_iclog)
2129 return xlog_state_release_iclog(log, iclog);
2130 ASSERT(flags & XLOG_COMMIT_TRANS);
2131 *commit_iclog = iclog;
2134 return 0;
2138 * Write some region out to in-core log
2140 * This will be called when writing externally provided regions or when
2141 * writing out a commit record for a given transaction.
2143 * General algorithm:
2144 * 1. Find total length of this write. This may include adding to the
2145 * lengths passed in.
2146 * 2. Check whether we violate the tickets reservation.
2147 * 3. While writing to this iclog
2148 * A. Reserve as much space in this iclog as can get
2149 * B. If this is first write, save away start lsn
2150 * C. While writing this region:
2151 * 1. If first write of transaction, write start record
2152 * 2. Write log operation header (header per region)
2153 * 3. Find out if we can fit entire region into this iclog
2154 * 4. Potentially, verify destination memcpy ptr
2155 * 5. Memcpy (partial) region
2156 * 6. If partial copy, release iclog; otherwise, continue
2157 * copying more regions into current iclog
2158 * 4. Mark want sync bit (in simulation mode)
2159 * 5. Release iclog for potential flush to on-disk log.
2161 * ERRORS:
2162 * 1. Panic if reservation is overrun. This should never happen since
2163 * reservation amounts are generated internal to the filesystem.
2164 * NOTES:
2165 * 1. Tickets are single threaded data structures.
2166 * 2. The XLOG_END_TRANS & XLOG_CONTINUE_TRANS flags are passed down to the
2167 * syncing routine. When a single log_write region needs to span
2168 * multiple in-core logs, the XLOG_CONTINUE_TRANS bit should be set
2169 * on all log operation writes which don't contain the end of the
2170 * region. The XLOG_END_TRANS bit is used for the in-core log
2171 * operation which contains the end of the continued log_write region.
2172 * 3. When xlog_state_get_iclog_space() grabs the rest of the current iclog,
2173 * we don't really know exactly how much space will be used. As a result,
2174 * we don't update ic_offset until the end when we know exactly how many
2175 * bytes have been written out.
2178 xlog_write(
2179 struct xlog *log,
2180 struct xfs_log_vec *log_vector,
2181 struct xlog_ticket *ticket,
2182 xfs_lsn_t *start_lsn,
2183 struct xlog_in_core **commit_iclog,
2184 uint flags)
2186 struct xlog_in_core *iclog = NULL;
2187 struct xfs_log_iovec *vecp;
2188 struct xfs_log_vec *lv;
2189 int len;
2190 int index;
2191 int partial_copy = 0;
2192 int partial_copy_len = 0;
2193 int contwr = 0;
2194 int record_cnt = 0;
2195 int data_cnt = 0;
2196 int error;
2198 *start_lsn = 0;
2200 len = xlog_write_calc_vec_length(ticket, log_vector);
2203 * Region headers and bytes are already accounted for.
2204 * We only need to take into account start records and
2205 * split regions in this function.
2207 if (ticket->t_flags & XLOG_TIC_INITED)
2208 ticket->t_curr_res -= sizeof(xlog_op_header_t);
2211 * Commit record headers need to be accounted for. These
2212 * come in as separate writes so are easy to detect.
2214 if (flags & (XLOG_COMMIT_TRANS | XLOG_UNMOUNT_TRANS))
2215 ticket->t_curr_res -= sizeof(xlog_op_header_t);
2217 if (ticket->t_curr_res < 0)
2218 xlog_print_tic_res(log->l_mp, ticket);
2220 index = 0;
2221 lv = log_vector;
2222 vecp = lv->lv_iovecp;
2223 while (lv && (!lv->lv_niovecs || index < lv->lv_niovecs)) {
2224 void *ptr;
2225 int log_offset;
2227 error = xlog_state_get_iclog_space(log, len, &iclog, ticket,
2228 &contwr, &log_offset);
2229 if (error)
2230 return error;
2232 ASSERT(log_offset <= iclog->ic_size - 1);
2233 ptr = iclog->ic_datap + log_offset;
2235 /* start_lsn is the first lsn written to. That's all we need. */
2236 if (!*start_lsn)
2237 *start_lsn = be64_to_cpu(iclog->ic_header.h_lsn);
2240 * This loop writes out as many regions as can fit in the amount
2241 * of space which was allocated by xlog_state_get_iclog_space().
2243 while (lv && (!lv->lv_niovecs || index < lv->lv_niovecs)) {
2244 struct xfs_log_iovec *reg;
2245 struct xlog_op_header *ophdr;
2246 int start_rec_copy;
2247 int copy_len;
2248 int copy_off;
2249 bool ordered = false;
2251 /* ordered log vectors have no regions to write */
2252 if (lv->lv_buf_len == XFS_LOG_VEC_ORDERED) {
2253 ASSERT(lv->lv_niovecs == 0);
2254 ordered = true;
2255 goto next_lv;
2258 reg = &vecp[index];
2259 ASSERT(reg->i_len % sizeof(__int32_t) == 0);
2260 ASSERT((unsigned long)ptr % sizeof(__int32_t) == 0);
2262 start_rec_copy = xlog_write_start_rec(ptr, ticket);
2263 if (start_rec_copy) {
2264 record_cnt++;
2265 xlog_write_adv_cnt(&ptr, &len, &log_offset,
2266 start_rec_copy);
2269 ophdr = xlog_write_setup_ophdr(log, ptr, ticket, flags);
2270 if (!ophdr)
2271 return XFS_ERROR(EIO);
2273 xlog_write_adv_cnt(&ptr, &len, &log_offset,
2274 sizeof(struct xlog_op_header));
2276 len += xlog_write_setup_copy(ticket, ophdr,
2277 iclog->ic_size-log_offset,
2278 reg->i_len,
2279 &copy_off, &copy_len,
2280 &partial_copy,
2281 &partial_copy_len);
2282 xlog_verify_dest_ptr(log, ptr);
2284 /* copy region */
2285 ASSERT(copy_len >= 0);
2286 memcpy(ptr, reg->i_addr + copy_off, copy_len);
2287 xlog_write_adv_cnt(&ptr, &len, &log_offset, copy_len);
2289 copy_len += start_rec_copy + sizeof(xlog_op_header_t);
2290 record_cnt++;
2291 data_cnt += contwr ? copy_len : 0;
2293 error = xlog_write_copy_finish(log, iclog, flags,
2294 &record_cnt, &data_cnt,
2295 &partial_copy,
2296 &partial_copy_len,
2297 log_offset,
2298 commit_iclog);
2299 if (error)
2300 return error;
2303 * if we had a partial copy, we need to get more iclog
2304 * space but we don't want to increment the region
2305 * index because there is still more is this region to
2306 * write.
2308 * If we completed writing this region, and we flushed
2309 * the iclog (indicated by resetting of the record
2310 * count), then we also need to get more log space. If
2311 * this was the last record, though, we are done and
2312 * can just return.
2314 if (partial_copy)
2315 break;
2317 if (++index == lv->lv_niovecs) {
2318 next_lv:
2319 lv = lv->lv_next;
2320 index = 0;
2321 if (lv)
2322 vecp = lv->lv_iovecp;
2324 if (record_cnt == 0 && ordered == false) {
2325 if (!lv)
2326 return 0;
2327 break;
2332 ASSERT(len == 0);
2334 xlog_state_finish_copy(log, iclog, record_cnt, data_cnt);
2335 if (!commit_iclog)
2336 return xlog_state_release_iclog(log, iclog);
2338 ASSERT(flags & XLOG_COMMIT_TRANS);
2339 *commit_iclog = iclog;
2340 return 0;
2344 /*****************************************************************************
2346 * State Machine functions
2348 *****************************************************************************
2351 /* Clean iclogs starting from the head. This ordering must be
2352 * maintained, so an iclog doesn't become ACTIVE beyond one that
2353 * is SYNCING. This is also required to maintain the notion that we use
2354 * a ordered wait queue to hold off would be writers to the log when every
2355 * iclog is trying to sync to disk.
2357 * State Change: DIRTY -> ACTIVE
2359 STATIC void
2360 xlog_state_clean_log(
2361 struct xlog *log)
2363 xlog_in_core_t *iclog;
2364 int changed = 0;
2366 iclog = log->l_iclog;
2367 do {
2368 if (iclog->ic_state == XLOG_STATE_DIRTY) {
2369 iclog->ic_state = XLOG_STATE_ACTIVE;
2370 iclog->ic_offset = 0;
2371 ASSERT(iclog->ic_callback == NULL);
2373 * If the number of ops in this iclog indicate it just
2374 * contains the dummy transaction, we can
2375 * change state into IDLE (the second time around).
2376 * Otherwise we should change the state into
2377 * NEED a dummy.
2378 * We don't need to cover the dummy.
2380 if (!changed &&
2381 (be32_to_cpu(iclog->ic_header.h_num_logops) ==
2382 XLOG_COVER_OPS)) {
2383 changed = 1;
2384 } else {
2386 * We have two dirty iclogs so start over
2387 * This could also be num of ops indicates
2388 * this is not the dummy going out.
2390 changed = 2;
2392 iclog->ic_header.h_num_logops = 0;
2393 memset(iclog->ic_header.h_cycle_data, 0,
2394 sizeof(iclog->ic_header.h_cycle_data));
2395 iclog->ic_header.h_lsn = 0;
2396 } else if (iclog->ic_state == XLOG_STATE_ACTIVE)
2397 /* do nothing */;
2398 else
2399 break; /* stop cleaning */
2400 iclog = iclog->ic_next;
2401 } while (iclog != log->l_iclog);
2403 /* log is locked when we are called */
2405 * Change state for the dummy log recording.
2406 * We usually go to NEED. But we go to NEED2 if the changed indicates
2407 * we are done writing the dummy record.
2408 * If we are done with the second dummy recored (DONE2), then
2409 * we go to IDLE.
2411 if (changed) {
2412 switch (log->l_covered_state) {
2413 case XLOG_STATE_COVER_IDLE:
2414 case XLOG_STATE_COVER_NEED:
2415 case XLOG_STATE_COVER_NEED2:
2416 log->l_covered_state = XLOG_STATE_COVER_NEED;
2417 break;
2419 case XLOG_STATE_COVER_DONE:
2420 if (changed == 1)
2421 log->l_covered_state = XLOG_STATE_COVER_NEED2;
2422 else
2423 log->l_covered_state = XLOG_STATE_COVER_NEED;
2424 break;
2426 case XLOG_STATE_COVER_DONE2:
2427 if (changed == 1)
2428 log->l_covered_state = XLOG_STATE_COVER_IDLE;
2429 else
2430 log->l_covered_state = XLOG_STATE_COVER_NEED;
2431 break;
2433 default:
2434 ASSERT(0);
2437 } /* xlog_state_clean_log */
2439 STATIC xfs_lsn_t
2440 xlog_get_lowest_lsn(
2441 struct xlog *log)
2443 xlog_in_core_t *lsn_log;
2444 xfs_lsn_t lowest_lsn, lsn;
2446 lsn_log = log->l_iclog;
2447 lowest_lsn = 0;
2448 do {
2449 if (!(lsn_log->ic_state & (XLOG_STATE_ACTIVE|XLOG_STATE_DIRTY))) {
2450 lsn = be64_to_cpu(lsn_log->ic_header.h_lsn);
2451 if ((lsn && !lowest_lsn) ||
2452 (XFS_LSN_CMP(lsn, lowest_lsn) < 0)) {
2453 lowest_lsn = lsn;
2456 lsn_log = lsn_log->ic_next;
2457 } while (lsn_log != log->l_iclog);
2458 return lowest_lsn;
2462 STATIC void
2463 xlog_state_do_callback(
2464 struct xlog *log,
2465 int aborted,
2466 struct xlog_in_core *ciclog)
2468 xlog_in_core_t *iclog;
2469 xlog_in_core_t *first_iclog; /* used to know when we've
2470 * processed all iclogs once */
2471 xfs_log_callback_t *cb, *cb_next;
2472 int flushcnt = 0;
2473 xfs_lsn_t lowest_lsn;
2474 int ioerrors; /* counter: iclogs with errors */
2475 int loopdidcallbacks; /* flag: inner loop did callbacks*/
2476 int funcdidcallbacks; /* flag: function did callbacks */
2477 int repeats; /* for issuing console warnings if
2478 * looping too many times */
2479 int wake = 0;
2481 spin_lock(&log->l_icloglock);
2482 first_iclog = iclog = log->l_iclog;
2483 ioerrors = 0;
2484 funcdidcallbacks = 0;
2485 repeats = 0;
2487 do {
2489 * Scan all iclogs starting with the one pointed to by the
2490 * log. Reset this starting point each time the log is
2491 * unlocked (during callbacks).
2493 * Keep looping through iclogs until one full pass is made
2494 * without running any callbacks.
2496 first_iclog = log->l_iclog;
2497 iclog = log->l_iclog;
2498 loopdidcallbacks = 0;
2499 repeats++;
2501 do {
2503 /* skip all iclogs in the ACTIVE & DIRTY states */
2504 if (iclog->ic_state &
2505 (XLOG_STATE_ACTIVE|XLOG_STATE_DIRTY)) {
2506 iclog = iclog->ic_next;
2507 continue;
2511 * Between marking a filesystem SHUTDOWN and stopping
2512 * the log, we do flush all iclogs to disk (if there
2513 * wasn't a log I/O error). So, we do want things to
2514 * go smoothly in case of just a SHUTDOWN w/o a
2515 * LOG_IO_ERROR.
2517 if (!(iclog->ic_state & XLOG_STATE_IOERROR)) {
2519 * Can only perform callbacks in order. Since
2520 * this iclog is not in the DONE_SYNC/
2521 * DO_CALLBACK state, we skip the rest and
2522 * just try to clean up. If we set our iclog
2523 * to DO_CALLBACK, we will not process it when
2524 * we retry since a previous iclog is in the
2525 * CALLBACK and the state cannot change since
2526 * we are holding the l_icloglock.
2528 if (!(iclog->ic_state &
2529 (XLOG_STATE_DONE_SYNC |
2530 XLOG_STATE_DO_CALLBACK))) {
2531 if (ciclog && (ciclog->ic_state ==
2532 XLOG_STATE_DONE_SYNC)) {
2533 ciclog->ic_state = XLOG_STATE_DO_CALLBACK;
2535 break;
2538 * We now have an iclog that is in either the
2539 * DO_CALLBACK or DONE_SYNC states. The other
2540 * states (WANT_SYNC, SYNCING, or CALLBACK were
2541 * caught by the above if and are going to
2542 * clean (i.e. we aren't doing their callbacks)
2543 * see the above if.
2547 * We will do one more check here to see if we
2548 * have chased our tail around.
2551 lowest_lsn = xlog_get_lowest_lsn(log);
2552 if (lowest_lsn &&
2553 XFS_LSN_CMP(lowest_lsn,
2554 be64_to_cpu(iclog->ic_header.h_lsn)) < 0) {
2555 iclog = iclog->ic_next;
2556 continue; /* Leave this iclog for
2557 * another thread */
2560 iclog->ic_state = XLOG_STATE_CALLBACK;
2564 * Completion of a iclog IO does not imply that
2565 * a transaction has completed, as transactions
2566 * can be large enough to span many iclogs. We
2567 * cannot change the tail of the log half way
2568 * through a transaction as this may be the only
2569 * transaction in the log and moving th etail to
2570 * point to the middle of it will prevent
2571 * recovery from finding the start of the
2572 * transaction. Hence we should only update the
2573 * last_sync_lsn if this iclog contains
2574 * transaction completion callbacks on it.
2576 * We have to do this before we drop the
2577 * icloglock to ensure we are the only one that
2578 * can update it.
2580 ASSERT(XFS_LSN_CMP(atomic64_read(&log->l_last_sync_lsn),
2581 be64_to_cpu(iclog->ic_header.h_lsn)) <= 0);
2582 if (iclog->ic_callback)
2583 atomic64_set(&log->l_last_sync_lsn,
2584 be64_to_cpu(iclog->ic_header.h_lsn));
2586 } else
2587 ioerrors++;
2589 spin_unlock(&log->l_icloglock);
2592 * Keep processing entries in the callback list until
2593 * we come around and it is empty. We need to
2594 * atomically see that the list is empty and change the
2595 * state to DIRTY so that we don't miss any more
2596 * callbacks being added.
2598 spin_lock(&iclog->ic_callback_lock);
2599 cb = iclog->ic_callback;
2600 while (cb) {
2601 iclog->ic_callback_tail = &(iclog->ic_callback);
2602 iclog->ic_callback = NULL;
2603 spin_unlock(&iclog->ic_callback_lock);
2605 /* perform callbacks in the order given */
2606 for (; cb; cb = cb_next) {
2607 cb_next = cb->cb_next;
2608 cb->cb_func(cb->cb_arg, aborted);
2610 spin_lock(&iclog->ic_callback_lock);
2611 cb = iclog->ic_callback;
2614 loopdidcallbacks++;
2615 funcdidcallbacks++;
2617 spin_lock(&log->l_icloglock);
2618 ASSERT(iclog->ic_callback == NULL);
2619 spin_unlock(&iclog->ic_callback_lock);
2620 if (!(iclog->ic_state & XLOG_STATE_IOERROR))
2621 iclog->ic_state = XLOG_STATE_DIRTY;
2624 * Transition from DIRTY to ACTIVE if applicable.
2625 * NOP if STATE_IOERROR.
2627 xlog_state_clean_log(log);
2629 /* wake up threads waiting in xfs_log_force() */
2630 wake_up_all(&iclog->ic_force_wait);
2632 iclog = iclog->ic_next;
2633 } while (first_iclog != iclog);
2635 if (repeats > 5000) {
2636 flushcnt += repeats;
2637 repeats = 0;
2638 xfs_warn(log->l_mp,
2639 "%s: possible infinite loop (%d iterations)",
2640 __func__, flushcnt);
2642 } while (!ioerrors && loopdidcallbacks);
2645 * make one last gasp attempt to see if iclogs are being left in
2646 * limbo..
2648 #ifdef DEBUG
2649 if (funcdidcallbacks) {
2650 first_iclog = iclog = log->l_iclog;
2651 do {
2652 ASSERT(iclog->ic_state != XLOG_STATE_DO_CALLBACK);
2654 * Terminate the loop if iclogs are found in states
2655 * which will cause other threads to clean up iclogs.
2657 * SYNCING - i/o completion will go through logs
2658 * DONE_SYNC - interrupt thread should be waiting for
2659 * l_icloglock
2660 * IOERROR - give up hope all ye who enter here
2662 if (iclog->ic_state == XLOG_STATE_WANT_SYNC ||
2663 iclog->ic_state == XLOG_STATE_SYNCING ||
2664 iclog->ic_state == XLOG_STATE_DONE_SYNC ||
2665 iclog->ic_state == XLOG_STATE_IOERROR )
2666 break;
2667 iclog = iclog->ic_next;
2668 } while (first_iclog != iclog);
2670 #endif
2672 if (log->l_iclog->ic_state & (XLOG_STATE_ACTIVE|XLOG_STATE_IOERROR))
2673 wake = 1;
2674 spin_unlock(&log->l_icloglock);
2676 if (wake)
2677 wake_up_all(&log->l_flush_wait);
2682 * Finish transitioning this iclog to the dirty state.
2684 * Make sure that we completely execute this routine only when this is
2685 * the last call to the iclog. There is a good chance that iclog flushes,
2686 * when we reach the end of the physical log, get turned into 2 separate
2687 * calls to bwrite. Hence, one iclog flush could generate two calls to this
2688 * routine. By using the reference count bwritecnt, we guarantee that only
2689 * the second completion goes through.
2691 * Callbacks could take time, so they are done outside the scope of the
2692 * global state machine log lock.
2694 STATIC void
2695 xlog_state_done_syncing(
2696 xlog_in_core_t *iclog,
2697 int aborted)
2699 struct xlog *log = iclog->ic_log;
2701 spin_lock(&log->l_icloglock);
2703 ASSERT(iclog->ic_state == XLOG_STATE_SYNCING ||
2704 iclog->ic_state == XLOG_STATE_IOERROR);
2705 ASSERT(atomic_read(&iclog->ic_refcnt) == 0);
2706 ASSERT(iclog->ic_bwritecnt == 1 || iclog->ic_bwritecnt == 2);
2710 * If we got an error, either on the first buffer, or in the case of
2711 * split log writes, on the second, we mark ALL iclogs STATE_IOERROR,
2712 * and none should ever be attempted to be written to disk
2713 * again.
2715 if (iclog->ic_state != XLOG_STATE_IOERROR) {
2716 if (--iclog->ic_bwritecnt == 1) {
2717 spin_unlock(&log->l_icloglock);
2718 return;
2720 iclog->ic_state = XLOG_STATE_DONE_SYNC;
2724 * Someone could be sleeping prior to writing out the next
2725 * iclog buffer, we wake them all, one will get to do the
2726 * I/O, the others get to wait for the result.
2728 wake_up_all(&iclog->ic_write_wait);
2729 spin_unlock(&log->l_icloglock);
2730 xlog_state_do_callback(log, aborted, iclog); /* also cleans log */
2731 } /* xlog_state_done_syncing */
2735 * If the head of the in-core log ring is not (ACTIVE or DIRTY), then we must
2736 * sleep. We wait on the flush queue on the head iclog as that should be
2737 * the first iclog to complete flushing. Hence if all iclogs are syncing,
2738 * we will wait here and all new writes will sleep until a sync completes.
2740 * The in-core logs are used in a circular fashion. They are not used
2741 * out-of-order even when an iclog past the head is free.
2743 * return:
2744 * * log_offset where xlog_write() can start writing into the in-core
2745 * log's data space.
2746 * * in-core log pointer to which xlog_write() should write.
2747 * * boolean indicating this is a continued write to an in-core log.
2748 * If this is the last write, then the in-core log's offset field
2749 * needs to be incremented, depending on the amount of data which
2750 * is copied.
2752 STATIC int
2753 xlog_state_get_iclog_space(
2754 struct xlog *log,
2755 int len,
2756 struct xlog_in_core **iclogp,
2757 struct xlog_ticket *ticket,
2758 int *continued_write,
2759 int *logoffsetp)
2761 int log_offset;
2762 xlog_rec_header_t *head;
2763 xlog_in_core_t *iclog;
2764 int error;
2766 restart:
2767 spin_lock(&log->l_icloglock);
2768 if (XLOG_FORCED_SHUTDOWN(log)) {
2769 spin_unlock(&log->l_icloglock);
2770 return XFS_ERROR(EIO);
2773 iclog = log->l_iclog;
2774 if (iclog->ic_state != XLOG_STATE_ACTIVE) {
2775 XFS_STATS_INC(xs_log_noiclogs);
2777 /* Wait for log writes to have flushed */
2778 xlog_wait(&log->l_flush_wait, &log->l_icloglock);
2779 goto restart;
2782 head = &iclog->ic_header;
2784 atomic_inc(&iclog->ic_refcnt); /* prevents sync */
2785 log_offset = iclog->ic_offset;
2787 /* On the 1st write to an iclog, figure out lsn. This works
2788 * if iclogs marked XLOG_STATE_WANT_SYNC always write out what they are
2789 * committing to. If the offset is set, that's how many blocks
2790 * must be written.
2792 if (log_offset == 0) {
2793 ticket->t_curr_res -= log->l_iclog_hsize;
2794 xlog_tic_add_region(ticket,
2795 log->l_iclog_hsize,
2796 XLOG_REG_TYPE_LRHEADER);
2797 head->h_cycle = cpu_to_be32(log->l_curr_cycle);
2798 head->h_lsn = cpu_to_be64(
2799 xlog_assign_lsn(log->l_curr_cycle, log->l_curr_block));
2800 ASSERT(log->l_curr_block >= 0);
2803 /* If there is enough room to write everything, then do it. Otherwise,
2804 * claim the rest of the region and make sure the XLOG_STATE_WANT_SYNC
2805 * bit is on, so this will get flushed out. Don't update ic_offset
2806 * until you know exactly how many bytes get copied. Therefore, wait
2807 * until later to update ic_offset.
2809 * xlog_write() algorithm assumes that at least 2 xlog_op_header_t's
2810 * can fit into remaining data section.
2812 if (iclog->ic_size - iclog->ic_offset < 2*sizeof(xlog_op_header_t)) {
2813 xlog_state_switch_iclogs(log, iclog, iclog->ic_size);
2816 * If I'm the only one writing to this iclog, sync it to disk.
2817 * We need to do an atomic compare and decrement here to avoid
2818 * racing with concurrent atomic_dec_and_lock() calls in
2819 * xlog_state_release_iclog() when there is more than one
2820 * reference to the iclog.
2822 if (!atomic_add_unless(&iclog->ic_refcnt, -1, 1)) {
2823 /* we are the only one */
2824 spin_unlock(&log->l_icloglock);
2825 error = xlog_state_release_iclog(log, iclog);
2826 if (error)
2827 return error;
2828 } else {
2829 spin_unlock(&log->l_icloglock);
2831 goto restart;
2834 /* Do we have enough room to write the full amount in the remainder
2835 * of this iclog? Or must we continue a write on the next iclog and
2836 * mark this iclog as completely taken? In the case where we switch
2837 * iclogs (to mark it taken), this particular iclog will release/sync
2838 * to disk in xlog_write().
2840 if (len <= iclog->ic_size - iclog->ic_offset) {
2841 *continued_write = 0;
2842 iclog->ic_offset += len;
2843 } else {
2844 *continued_write = 1;
2845 xlog_state_switch_iclogs(log, iclog, iclog->ic_size);
2847 *iclogp = iclog;
2849 ASSERT(iclog->ic_offset <= iclog->ic_size);
2850 spin_unlock(&log->l_icloglock);
2852 *logoffsetp = log_offset;
2853 return 0;
2854 } /* xlog_state_get_iclog_space */
2856 /* The first cnt-1 times through here we don't need to
2857 * move the grant write head because the permanent
2858 * reservation has reserved cnt times the unit amount.
2859 * Release part of current permanent unit reservation and
2860 * reset current reservation to be one units worth. Also
2861 * move grant reservation head forward.
2863 STATIC void
2864 xlog_regrant_reserve_log_space(
2865 struct xlog *log,
2866 struct xlog_ticket *ticket)
2868 trace_xfs_log_regrant_reserve_enter(log, ticket);
2870 if (ticket->t_cnt > 0)
2871 ticket->t_cnt--;
2873 xlog_grant_sub_space(log, &log->l_reserve_head.grant,
2874 ticket->t_curr_res);
2875 xlog_grant_sub_space(log, &log->l_write_head.grant,
2876 ticket->t_curr_res);
2877 ticket->t_curr_res = ticket->t_unit_res;
2878 xlog_tic_reset_res(ticket);
2880 trace_xfs_log_regrant_reserve_sub(log, ticket);
2882 /* just return if we still have some of the pre-reserved space */
2883 if (ticket->t_cnt > 0)
2884 return;
2886 xlog_grant_add_space(log, &log->l_reserve_head.grant,
2887 ticket->t_unit_res);
2889 trace_xfs_log_regrant_reserve_exit(log, ticket);
2891 ticket->t_curr_res = ticket->t_unit_res;
2892 xlog_tic_reset_res(ticket);
2893 } /* xlog_regrant_reserve_log_space */
2897 * Give back the space left from a reservation.
2899 * All the information we need to make a correct determination of space left
2900 * is present. For non-permanent reservations, things are quite easy. The
2901 * count should have been decremented to zero. We only need to deal with the
2902 * space remaining in the current reservation part of the ticket. If the
2903 * ticket contains a permanent reservation, there may be left over space which
2904 * needs to be released. A count of N means that N-1 refills of the current
2905 * reservation can be done before we need to ask for more space. The first
2906 * one goes to fill up the first current reservation. Once we run out of
2907 * space, the count will stay at zero and the only space remaining will be
2908 * in the current reservation field.
2910 STATIC void
2911 xlog_ungrant_log_space(
2912 struct xlog *log,
2913 struct xlog_ticket *ticket)
2915 int bytes;
2917 if (ticket->t_cnt > 0)
2918 ticket->t_cnt--;
2920 trace_xfs_log_ungrant_enter(log, ticket);
2921 trace_xfs_log_ungrant_sub(log, ticket);
2924 * If this is a permanent reservation ticket, we may be able to free
2925 * up more space based on the remaining count.
2927 bytes = ticket->t_curr_res;
2928 if (ticket->t_cnt > 0) {
2929 ASSERT(ticket->t_flags & XLOG_TIC_PERM_RESERV);
2930 bytes += ticket->t_unit_res*ticket->t_cnt;
2933 xlog_grant_sub_space(log, &log->l_reserve_head.grant, bytes);
2934 xlog_grant_sub_space(log, &log->l_write_head.grant, bytes);
2936 trace_xfs_log_ungrant_exit(log, ticket);
2938 xfs_log_space_wake(log->l_mp);
2942 * Flush iclog to disk if this is the last reference to the given iclog and
2943 * the WANT_SYNC bit is set.
2945 * When this function is entered, the iclog is not necessarily in the
2946 * WANT_SYNC state. It may be sitting around waiting to get filled.
2950 STATIC int
2951 xlog_state_release_iclog(
2952 struct xlog *log,
2953 struct xlog_in_core *iclog)
2955 int sync = 0; /* do we sync? */
2957 if (iclog->ic_state & XLOG_STATE_IOERROR)
2958 return XFS_ERROR(EIO);
2960 ASSERT(atomic_read(&iclog->ic_refcnt) > 0);
2961 if (!atomic_dec_and_lock(&iclog->ic_refcnt, &log->l_icloglock))
2962 return 0;
2964 if (iclog->ic_state & XLOG_STATE_IOERROR) {
2965 spin_unlock(&log->l_icloglock);
2966 return XFS_ERROR(EIO);
2968 ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE ||
2969 iclog->ic_state == XLOG_STATE_WANT_SYNC);
2971 if (iclog->ic_state == XLOG_STATE_WANT_SYNC) {
2972 /* update tail before writing to iclog */
2973 xfs_lsn_t tail_lsn = xlog_assign_tail_lsn(log->l_mp);
2974 sync++;
2975 iclog->ic_state = XLOG_STATE_SYNCING;
2976 iclog->ic_header.h_tail_lsn = cpu_to_be64(tail_lsn);
2977 xlog_verify_tail_lsn(log, iclog, tail_lsn);
2978 /* cycle incremented when incrementing curr_block */
2980 spin_unlock(&log->l_icloglock);
2983 * We let the log lock go, so it's possible that we hit a log I/O
2984 * error or some other SHUTDOWN condition that marks the iclog
2985 * as XLOG_STATE_IOERROR before the bwrite. However, we know that
2986 * this iclog has consistent data, so we ignore IOERROR
2987 * flags after this point.
2989 if (sync)
2990 return xlog_sync(log, iclog);
2991 return 0;
2992 } /* xlog_state_release_iclog */
2996 * This routine will mark the current iclog in the ring as WANT_SYNC
2997 * and move the current iclog pointer to the next iclog in the ring.
2998 * When this routine is called from xlog_state_get_iclog_space(), the
2999 * exact size of the iclog has not yet been determined. All we know is
3000 * that every data block. We have run out of space in this log record.
3002 STATIC void
3003 xlog_state_switch_iclogs(
3004 struct xlog *log,
3005 struct xlog_in_core *iclog,
3006 int eventual_size)
3008 ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE);
3009 if (!eventual_size)
3010 eventual_size = iclog->ic_offset;
3011 iclog->ic_state = XLOG_STATE_WANT_SYNC;
3012 iclog->ic_header.h_prev_block = cpu_to_be32(log->l_prev_block);
3013 log->l_prev_block = log->l_curr_block;
3014 log->l_prev_cycle = log->l_curr_cycle;
3016 /* roll log?: ic_offset changed later */
3017 log->l_curr_block += BTOBB(eventual_size)+BTOBB(log->l_iclog_hsize);
3019 /* Round up to next log-sunit */
3020 if (xfs_sb_version_haslogv2(&log->l_mp->m_sb) &&
3021 log->l_mp->m_sb.sb_logsunit > 1) {
3022 __uint32_t sunit_bb = BTOBB(log->l_mp->m_sb.sb_logsunit);
3023 log->l_curr_block = roundup(log->l_curr_block, sunit_bb);
3026 if (log->l_curr_block >= log->l_logBBsize) {
3027 log->l_curr_cycle++;
3028 if (log->l_curr_cycle == XLOG_HEADER_MAGIC_NUM)
3029 log->l_curr_cycle++;
3030 log->l_curr_block -= log->l_logBBsize;
3031 ASSERT(log->l_curr_block >= 0);
3033 ASSERT(iclog == log->l_iclog);
3034 log->l_iclog = iclog->ic_next;
3035 } /* xlog_state_switch_iclogs */
3038 * Write out all data in the in-core log as of this exact moment in time.
3040 * Data may be written to the in-core log during this call. However,
3041 * we don't guarantee this data will be written out. A change from past
3042 * implementation means this routine will *not* write out zero length LRs.
3044 * Basically, we try and perform an intelligent scan of the in-core logs.
3045 * If we determine there is no flushable data, we just return. There is no
3046 * flushable data if:
3048 * 1. the current iclog is active and has no data; the previous iclog
3049 * is in the active or dirty state.
3050 * 2. the current iclog is drity, and the previous iclog is in the
3051 * active or dirty state.
3053 * We may sleep if:
3055 * 1. the current iclog is not in the active nor dirty state.
3056 * 2. the current iclog dirty, and the previous iclog is not in the
3057 * active nor dirty state.
3058 * 3. the current iclog is active, and there is another thread writing
3059 * to this particular iclog.
3060 * 4. a) the current iclog is active and has no other writers
3061 * b) when we return from flushing out this iclog, it is still
3062 * not in the active nor dirty state.
3065 _xfs_log_force(
3066 struct xfs_mount *mp,
3067 uint flags,
3068 int *log_flushed)
3070 struct xlog *log = mp->m_log;
3071 struct xlog_in_core *iclog;
3072 xfs_lsn_t lsn;
3074 XFS_STATS_INC(xs_log_force);
3076 xlog_cil_force(log);
3078 spin_lock(&log->l_icloglock);
3080 iclog = log->l_iclog;
3081 if (iclog->ic_state & XLOG_STATE_IOERROR) {
3082 spin_unlock(&log->l_icloglock);
3083 return XFS_ERROR(EIO);
3086 /* If the head iclog is not active nor dirty, we just attach
3087 * ourselves to the head and go to sleep.
3089 if (iclog->ic_state == XLOG_STATE_ACTIVE ||
3090 iclog->ic_state == XLOG_STATE_DIRTY) {
3092 * If the head is dirty or (active and empty), then
3093 * we need to look at the previous iclog. If the previous
3094 * iclog is active or dirty we are done. There is nothing
3095 * to sync out. Otherwise, we attach ourselves to the
3096 * previous iclog and go to sleep.
3098 if (iclog->ic_state == XLOG_STATE_DIRTY ||
3099 (atomic_read(&iclog->ic_refcnt) == 0
3100 && iclog->ic_offset == 0)) {
3101 iclog = iclog->ic_prev;
3102 if (iclog->ic_state == XLOG_STATE_ACTIVE ||
3103 iclog->ic_state == XLOG_STATE_DIRTY)
3104 goto no_sleep;
3105 else
3106 goto maybe_sleep;
3107 } else {
3108 if (atomic_read(&iclog->ic_refcnt) == 0) {
3109 /* We are the only one with access to this
3110 * iclog. Flush it out now. There should
3111 * be a roundoff of zero to show that someone
3112 * has already taken care of the roundoff from
3113 * the previous sync.
3115 atomic_inc(&iclog->ic_refcnt);
3116 lsn = be64_to_cpu(iclog->ic_header.h_lsn);
3117 xlog_state_switch_iclogs(log, iclog, 0);
3118 spin_unlock(&log->l_icloglock);
3120 if (xlog_state_release_iclog(log, iclog))
3121 return XFS_ERROR(EIO);
3123 if (log_flushed)
3124 *log_flushed = 1;
3125 spin_lock(&log->l_icloglock);
3126 if (be64_to_cpu(iclog->ic_header.h_lsn) == lsn &&
3127 iclog->ic_state != XLOG_STATE_DIRTY)
3128 goto maybe_sleep;
3129 else
3130 goto no_sleep;
3131 } else {
3132 /* Someone else is writing to this iclog.
3133 * Use its call to flush out the data. However,
3134 * the other thread may not force out this LR,
3135 * so we mark it WANT_SYNC.
3137 xlog_state_switch_iclogs(log, iclog, 0);
3138 goto maybe_sleep;
3143 /* By the time we come around again, the iclog could've been filled
3144 * which would give it another lsn. If we have a new lsn, just
3145 * return because the relevant data has been flushed.
3147 maybe_sleep:
3148 if (flags & XFS_LOG_SYNC) {
3150 * We must check if we're shutting down here, before
3151 * we wait, while we're holding the l_icloglock.
3152 * Then we check again after waking up, in case our
3153 * sleep was disturbed by a bad news.
3155 if (iclog->ic_state & XLOG_STATE_IOERROR) {
3156 spin_unlock(&log->l_icloglock);
3157 return XFS_ERROR(EIO);
3159 XFS_STATS_INC(xs_log_force_sleep);
3160 xlog_wait(&iclog->ic_force_wait, &log->l_icloglock);
3162 * No need to grab the log lock here since we're
3163 * only deciding whether or not to return EIO
3164 * and the memory read should be atomic.
3166 if (iclog->ic_state & XLOG_STATE_IOERROR)
3167 return XFS_ERROR(EIO);
3168 if (log_flushed)
3169 *log_flushed = 1;
3170 } else {
3172 no_sleep:
3173 spin_unlock(&log->l_icloglock);
3175 return 0;
3179 * Wrapper for _xfs_log_force(), to be used when caller doesn't care
3180 * about errors or whether the log was flushed or not. This is the normal
3181 * interface to use when trying to unpin items or move the log forward.
3183 void
3184 xfs_log_force(
3185 xfs_mount_t *mp,
3186 uint flags)
3188 int error;
3190 trace_xfs_log_force(mp, 0);
3191 error = _xfs_log_force(mp, flags, NULL);
3192 if (error)
3193 xfs_warn(mp, "%s: error %d returned.", __func__, error);
3197 * Force the in-core log to disk for a specific LSN.
3199 * Find in-core log with lsn.
3200 * If it is in the DIRTY state, just return.
3201 * If it is in the ACTIVE state, move the in-core log into the WANT_SYNC
3202 * state and go to sleep or return.
3203 * If it is in any other state, go to sleep or return.
3205 * Synchronous forces are implemented with a signal variable. All callers
3206 * to force a given lsn to disk will wait on a the sv attached to the
3207 * specific in-core log. When given in-core log finally completes its
3208 * write to disk, that thread will wake up all threads waiting on the
3209 * sv.
3212 _xfs_log_force_lsn(
3213 struct xfs_mount *mp,
3214 xfs_lsn_t lsn,
3215 uint flags,
3216 int *log_flushed)
3218 struct xlog *log = mp->m_log;
3219 struct xlog_in_core *iclog;
3220 int already_slept = 0;
3222 ASSERT(lsn != 0);
3224 XFS_STATS_INC(xs_log_force);
3226 lsn = xlog_cil_force_lsn(log, lsn);
3227 if (lsn == NULLCOMMITLSN)
3228 return 0;
3230 try_again:
3231 spin_lock(&log->l_icloglock);
3232 iclog = log->l_iclog;
3233 if (iclog->ic_state & XLOG_STATE_IOERROR) {
3234 spin_unlock(&log->l_icloglock);
3235 return XFS_ERROR(EIO);
3238 do {
3239 if (be64_to_cpu(iclog->ic_header.h_lsn) != lsn) {
3240 iclog = iclog->ic_next;
3241 continue;
3244 if (iclog->ic_state == XLOG_STATE_DIRTY) {
3245 spin_unlock(&log->l_icloglock);
3246 return 0;
3249 if (iclog->ic_state == XLOG_STATE_ACTIVE) {
3251 * We sleep here if we haven't already slept (e.g.
3252 * this is the first time we've looked at the correct
3253 * iclog buf) and the buffer before us is going to
3254 * be sync'ed. The reason for this is that if we
3255 * are doing sync transactions here, by waiting for
3256 * the previous I/O to complete, we can allow a few
3257 * more transactions into this iclog before we close
3258 * it down.
3260 * Otherwise, we mark the buffer WANT_SYNC, and bump
3261 * up the refcnt so we can release the log (which
3262 * drops the ref count). The state switch keeps new
3263 * transaction commits from using this buffer. When
3264 * the current commits finish writing into the buffer,
3265 * the refcount will drop to zero and the buffer will
3266 * go out then.
3268 if (!already_slept &&
3269 (iclog->ic_prev->ic_state &
3270 (XLOG_STATE_WANT_SYNC | XLOG_STATE_SYNCING))) {
3271 ASSERT(!(iclog->ic_state & XLOG_STATE_IOERROR));
3273 XFS_STATS_INC(xs_log_force_sleep);
3275 xlog_wait(&iclog->ic_prev->ic_write_wait,
3276 &log->l_icloglock);
3277 if (log_flushed)
3278 *log_flushed = 1;
3279 already_slept = 1;
3280 goto try_again;
3282 atomic_inc(&iclog->ic_refcnt);
3283 xlog_state_switch_iclogs(log, iclog, 0);
3284 spin_unlock(&log->l_icloglock);
3285 if (xlog_state_release_iclog(log, iclog))
3286 return XFS_ERROR(EIO);
3287 if (log_flushed)
3288 *log_flushed = 1;
3289 spin_lock(&log->l_icloglock);
3292 if ((flags & XFS_LOG_SYNC) && /* sleep */
3293 !(iclog->ic_state &
3294 (XLOG_STATE_ACTIVE | XLOG_STATE_DIRTY))) {
3296 * Don't wait on completion if we know that we've
3297 * gotten a log write error.
3299 if (iclog->ic_state & XLOG_STATE_IOERROR) {
3300 spin_unlock(&log->l_icloglock);
3301 return XFS_ERROR(EIO);
3303 XFS_STATS_INC(xs_log_force_sleep);
3304 xlog_wait(&iclog->ic_force_wait, &log->l_icloglock);
3306 * No need to grab the log lock here since we're
3307 * only deciding whether or not to return EIO
3308 * and the memory read should be atomic.
3310 if (iclog->ic_state & XLOG_STATE_IOERROR)
3311 return XFS_ERROR(EIO);
3313 if (log_flushed)
3314 *log_flushed = 1;
3315 } else { /* just return */
3316 spin_unlock(&log->l_icloglock);
3319 return 0;
3320 } while (iclog != log->l_iclog);
3322 spin_unlock(&log->l_icloglock);
3323 return 0;
3327 * Wrapper for _xfs_log_force_lsn(), to be used when caller doesn't care
3328 * about errors or whether the log was flushed or not. This is the normal
3329 * interface to use when trying to unpin items or move the log forward.
3331 void
3332 xfs_log_force_lsn(
3333 xfs_mount_t *mp,
3334 xfs_lsn_t lsn,
3335 uint flags)
3337 int error;
3339 trace_xfs_log_force(mp, lsn);
3340 error = _xfs_log_force_lsn(mp, lsn, flags, NULL);
3341 if (error)
3342 xfs_warn(mp, "%s: error %d returned.", __func__, error);
3346 * Called when we want to mark the current iclog as being ready to sync to
3347 * disk.
3349 STATIC void
3350 xlog_state_want_sync(
3351 struct xlog *log,
3352 struct xlog_in_core *iclog)
3354 assert_spin_locked(&log->l_icloglock);
3356 if (iclog->ic_state == XLOG_STATE_ACTIVE) {
3357 xlog_state_switch_iclogs(log, iclog, 0);
3358 } else {
3359 ASSERT(iclog->ic_state &
3360 (XLOG_STATE_WANT_SYNC|XLOG_STATE_IOERROR));
3365 /*****************************************************************************
3367 * TICKET functions
3369 *****************************************************************************
3373 * Free a used ticket when its refcount falls to zero.
3375 void
3376 xfs_log_ticket_put(
3377 xlog_ticket_t *ticket)
3379 ASSERT(atomic_read(&ticket->t_ref) > 0);
3380 if (atomic_dec_and_test(&ticket->t_ref))
3381 kmem_zone_free(xfs_log_ticket_zone, ticket);
3384 xlog_ticket_t *
3385 xfs_log_ticket_get(
3386 xlog_ticket_t *ticket)
3388 ASSERT(atomic_read(&ticket->t_ref) > 0);
3389 atomic_inc(&ticket->t_ref);
3390 return ticket;
3394 * Allocate and initialise a new log ticket.
3396 struct xlog_ticket *
3397 xlog_ticket_alloc(
3398 struct xlog *log,
3399 int unit_bytes,
3400 int cnt,
3401 char client,
3402 bool permanent,
3403 xfs_km_flags_t alloc_flags)
3405 struct xlog_ticket *tic;
3406 uint num_headers;
3407 int iclog_space;
3409 tic = kmem_zone_zalloc(xfs_log_ticket_zone, alloc_flags);
3410 if (!tic)
3411 return NULL;
3414 * Permanent reservations have up to 'cnt'-1 active log operations
3415 * in the log. A unit in this case is the amount of space for one
3416 * of these log operations. Normal reservations have a cnt of 1
3417 * and their unit amount is the total amount of space required.
3419 * The following lines of code account for non-transaction data
3420 * which occupy space in the on-disk log.
3422 * Normal form of a transaction is:
3423 * <oph><trans-hdr><start-oph><reg1-oph><reg1><reg2-oph>...<commit-oph>
3424 * and then there are LR hdrs, split-recs and roundoff at end of syncs.
3426 * We need to account for all the leadup data and trailer data
3427 * around the transaction data.
3428 * And then we need to account for the worst case in terms of using
3429 * more space.
3430 * The worst case will happen if:
3431 * - the placement of the transaction happens to be such that the
3432 * roundoff is at its maximum
3433 * - the transaction data is synced before the commit record is synced
3434 * i.e. <transaction-data><roundoff> | <commit-rec><roundoff>
3435 * Therefore the commit record is in its own Log Record.
3436 * This can happen as the commit record is called with its
3437 * own region to xlog_write().
3438 * This then means that in the worst case, roundoff can happen for
3439 * the commit-rec as well.
3440 * The commit-rec is smaller than padding in this scenario and so it is
3441 * not added separately.
3444 /* for trans header */
3445 unit_bytes += sizeof(xlog_op_header_t);
3446 unit_bytes += sizeof(xfs_trans_header_t);
3448 /* for start-rec */
3449 unit_bytes += sizeof(xlog_op_header_t);
3452 * for LR headers - the space for data in an iclog is the size minus
3453 * the space used for the headers. If we use the iclog size, then we
3454 * undercalculate the number of headers required.
3456 * Furthermore - the addition of op headers for split-recs might
3457 * increase the space required enough to require more log and op
3458 * headers, so take that into account too.
3460 * IMPORTANT: This reservation makes the assumption that if this
3461 * transaction is the first in an iclog and hence has the LR headers
3462 * accounted to it, then the remaining space in the iclog is
3463 * exclusively for this transaction. i.e. if the transaction is larger
3464 * than the iclog, it will be the only thing in that iclog.
3465 * Fundamentally, this means we must pass the entire log vector to
3466 * xlog_write to guarantee this.
3468 iclog_space = log->l_iclog_size - log->l_iclog_hsize;
3469 num_headers = howmany(unit_bytes, iclog_space);
3471 /* for split-recs - ophdrs added when data split over LRs */
3472 unit_bytes += sizeof(xlog_op_header_t) * num_headers;
3474 /* add extra header reservations if we overrun */
3475 while (!num_headers ||
3476 howmany(unit_bytes, iclog_space) > num_headers) {
3477 unit_bytes += sizeof(xlog_op_header_t);
3478 num_headers++;
3480 unit_bytes += log->l_iclog_hsize * num_headers;
3482 /* for commit-rec LR header - note: padding will subsume the ophdr */
3483 unit_bytes += log->l_iclog_hsize;
3485 /* for roundoff padding for transaction data and one for commit record */
3486 if (xfs_sb_version_haslogv2(&log->l_mp->m_sb) &&
3487 log->l_mp->m_sb.sb_logsunit > 1) {
3488 /* log su roundoff */
3489 unit_bytes += 2*log->l_mp->m_sb.sb_logsunit;
3490 } else {
3491 /* BB roundoff */
3492 unit_bytes += 2*BBSIZE;
3495 atomic_set(&tic->t_ref, 1);
3496 tic->t_task = current;
3497 INIT_LIST_HEAD(&tic->t_queue);
3498 tic->t_unit_res = unit_bytes;
3499 tic->t_curr_res = unit_bytes;
3500 tic->t_cnt = cnt;
3501 tic->t_ocnt = cnt;
3502 tic->t_tid = prandom_u32();
3503 tic->t_clientid = client;
3504 tic->t_flags = XLOG_TIC_INITED;
3505 tic->t_trans_type = 0;
3506 if (permanent)
3507 tic->t_flags |= XLOG_TIC_PERM_RESERV;
3509 xlog_tic_reset_res(tic);
3511 return tic;
3515 /******************************************************************************
3517 * Log debug routines
3519 ******************************************************************************
3521 #if defined(DEBUG)
3523 * Make sure that the destination ptr is within the valid data region of
3524 * one of the iclogs. This uses backup pointers stored in a different
3525 * part of the log in case we trash the log structure.
3527 void
3528 xlog_verify_dest_ptr(
3529 struct xlog *log,
3530 char *ptr)
3532 int i;
3533 int good_ptr = 0;
3535 for (i = 0; i < log->l_iclog_bufs; i++) {
3536 if (ptr >= log->l_iclog_bak[i] &&
3537 ptr <= log->l_iclog_bak[i] + log->l_iclog_size)
3538 good_ptr++;
3541 if (!good_ptr)
3542 xfs_emerg(log->l_mp, "%s: invalid ptr", __func__);
3546 * Check to make sure the grant write head didn't just over lap the tail. If
3547 * the cycles are the same, we can't be overlapping. Otherwise, make sure that
3548 * the cycles differ by exactly one and check the byte count.
3550 * This check is run unlocked, so can give false positives. Rather than assert
3551 * on failures, use a warn-once flag and a panic tag to allow the admin to
3552 * determine if they want to panic the machine when such an error occurs. For
3553 * debug kernels this will have the same effect as using an assert but, unlinke
3554 * an assert, it can be turned off at runtime.
3556 STATIC void
3557 xlog_verify_grant_tail(
3558 struct xlog *log)
3560 int tail_cycle, tail_blocks;
3561 int cycle, space;
3563 xlog_crack_grant_head(&log->l_write_head.grant, &cycle, &space);
3564 xlog_crack_atomic_lsn(&log->l_tail_lsn, &tail_cycle, &tail_blocks);
3565 if (tail_cycle != cycle) {
3566 if (cycle - 1 != tail_cycle &&
3567 !(log->l_flags & XLOG_TAIL_WARN)) {
3568 xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES,
3569 "%s: cycle - 1 != tail_cycle", __func__);
3570 log->l_flags |= XLOG_TAIL_WARN;
3573 if (space > BBTOB(tail_blocks) &&
3574 !(log->l_flags & XLOG_TAIL_WARN)) {
3575 xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES,
3576 "%s: space > BBTOB(tail_blocks)", __func__);
3577 log->l_flags |= XLOG_TAIL_WARN;
3582 /* check if it will fit */
3583 STATIC void
3584 xlog_verify_tail_lsn(
3585 struct xlog *log,
3586 struct xlog_in_core *iclog,
3587 xfs_lsn_t tail_lsn)
3589 int blocks;
3591 if (CYCLE_LSN(tail_lsn) == log->l_prev_cycle) {
3592 blocks =
3593 log->l_logBBsize - (log->l_prev_block - BLOCK_LSN(tail_lsn));
3594 if (blocks < BTOBB(iclog->ic_offset)+BTOBB(log->l_iclog_hsize))
3595 xfs_emerg(log->l_mp, "%s: ran out of log space", __func__);
3596 } else {
3597 ASSERT(CYCLE_LSN(tail_lsn)+1 == log->l_prev_cycle);
3599 if (BLOCK_LSN(tail_lsn) == log->l_prev_block)
3600 xfs_emerg(log->l_mp, "%s: tail wrapped", __func__);
3602 blocks = BLOCK_LSN(tail_lsn) - log->l_prev_block;
3603 if (blocks < BTOBB(iclog->ic_offset) + 1)
3604 xfs_emerg(log->l_mp, "%s: ran out of log space", __func__);
3606 } /* xlog_verify_tail_lsn */
3609 * Perform a number of checks on the iclog before writing to disk.
3611 * 1. Make sure the iclogs are still circular
3612 * 2. Make sure we have a good magic number
3613 * 3. Make sure we don't have magic numbers in the data
3614 * 4. Check fields of each log operation header for:
3615 * A. Valid client identifier
3616 * B. tid ptr value falls in valid ptr space (user space code)
3617 * C. Length in log record header is correct according to the
3618 * individual operation headers within record.
3619 * 5. When a bwrite will occur within 5 blocks of the front of the physical
3620 * log, check the preceding blocks of the physical log to make sure all
3621 * the cycle numbers agree with the current cycle number.
3623 STATIC void
3624 xlog_verify_iclog(
3625 struct xlog *log,
3626 struct xlog_in_core *iclog,
3627 int count,
3628 bool syncing)
3630 xlog_op_header_t *ophead;
3631 xlog_in_core_t *icptr;
3632 xlog_in_core_2_t *xhdr;
3633 xfs_caddr_t ptr;
3634 xfs_caddr_t base_ptr;
3635 __psint_t field_offset;
3636 __uint8_t clientid;
3637 int len, i, j, k, op_len;
3638 int idx;
3640 /* check validity of iclog pointers */
3641 spin_lock(&log->l_icloglock);
3642 icptr = log->l_iclog;
3643 for (i=0; i < log->l_iclog_bufs; i++) {
3644 if (icptr == NULL)
3645 xfs_emerg(log->l_mp, "%s: invalid ptr", __func__);
3646 icptr = icptr->ic_next;
3648 if (icptr != log->l_iclog)
3649 xfs_emerg(log->l_mp, "%s: corrupt iclog ring", __func__);
3650 spin_unlock(&log->l_icloglock);
3652 /* check log magic numbers */
3653 if (iclog->ic_header.h_magicno != cpu_to_be32(XLOG_HEADER_MAGIC_NUM))
3654 xfs_emerg(log->l_mp, "%s: invalid magic num", __func__);
3656 ptr = (xfs_caddr_t) &iclog->ic_header;
3657 for (ptr += BBSIZE; ptr < ((xfs_caddr_t)&iclog->ic_header) + count;
3658 ptr += BBSIZE) {
3659 if (*(__be32 *)ptr == cpu_to_be32(XLOG_HEADER_MAGIC_NUM))
3660 xfs_emerg(log->l_mp, "%s: unexpected magic num",
3661 __func__);
3664 /* check fields */
3665 len = be32_to_cpu(iclog->ic_header.h_num_logops);
3666 ptr = iclog->ic_datap;
3667 base_ptr = ptr;
3668 ophead = (xlog_op_header_t *)ptr;
3669 xhdr = iclog->ic_data;
3670 for (i = 0; i < len; i++) {
3671 ophead = (xlog_op_header_t *)ptr;
3673 /* clientid is only 1 byte */
3674 field_offset = (__psint_t)
3675 ((xfs_caddr_t)&(ophead->oh_clientid) - base_ptr);
3676 if (!syncing || (field_offset & 0x1ff)) {
3677 clientid = ophead->oh_clientid;
3678 } else {
3679 idx = BTOBBT((xfs_caddr_t)&(ophead->oh_clientid) - iclog->ic_datap);
3680 if (idx >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE)) {
3681 j = idx / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3682 k = idx % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3683 clientid = xlog_get_client_id(
3684 xhdr[j].hic_xheader.xh_cycle_data[k]);
3685 } else {
3686 clientid = xlog_get_client_id(
3687 iclog->ic_header.h_cycle_data[idx]);
3690 if (clientid != XFS_TRANSACTION && clientid != XFS_LOG)
3691 xfs_warn(log->l_mp,
3692 "%s: invalid clientid %d op 0x%p offset 0x%lx",
3693 __func__, clientid, ophead,
3694 (unsigned long)field_offset);
3696 /* check length */
3697 field_offset = (__psint_t)
3698 ((xfs_caddr_t)&(ophead->oh_len) - base_ptr);
3699 if (!syncing || (field_offset & 0x1ff)) {
3700 op_len = be32_to_cpu(ophead->oh_len);
3701 } else {
3702 idx = BTOBBT((__psint_t)&ophead->oh_len -
3703 (__psint_t)iclog->ic_datap);
3704 if (idx >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE)) {
3705 j = idx / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3706 k = idx % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3707 op_len = be32_to_cpu(xhdr[j].hic_xheader.xh_cycle_data[k]);
3708 } else {
3709 op_len = be32_to_cpu(iclog->ic_header.h_cycle_data[idx]);
3712 ptr += sizeof(xlog_op_header_t) + op_len;
3714 } /* xlog_verify_iclog */
3715 #endif
3718 * Mark all iclogs IOERROR. l_icloglock is held by the caller.
3720 STATIC int
3721 xlog_state_ioerror(
3722 struct xlog *log)
3724 xlog_in_core_t *iclog, *ic;
3726 iclog = log->l_iclog;
3727 if (! (iclog->ic_state & XLOG_STATE_IOERROR)) {
3729 * Mark all the incore logs IOERROR.
3730 * From now on, no log flushes will result.
3732 ic = iclog;
3733 do {
3734 ic->ic_state = XLOG_STATE_IOERROR;
3735 ic = ic->ic_next;
3736 } while (ic != iclog);
3737 return 0;
3740 * Return non-zero, if state transition has already happened.
3742 return 1;
3746 * This is called from xfs_force_shutdown, when we're forcibly
3747 * shutting down the filesystem, typically because of an IO error.
3748 * Our main objectives here are to make sure that:
3749 * a. the filesystem gets marked 'SHUTDOWN' for all interested
3750 * parties to find out, 'atomically'.
3751 * b. those who're sleeping on log reservations, pinned objects and
3752 * other resources get woken up, and be told the bad news.
3753 * c. nothing new gets queued up after (a) and (b) are done.
3754 * d. if !logerror, flush the iclogs to disk, then seal them off
3755 * for business.
3757 * Note: for delayed logging the !logerror case needs to flush the regions
3758 * held in memory out to the iclogs before flushing them to disk. This needs
3759 * to be done before the log is marked as shutdown, otherwise the flush to the
3760 * iclogs will fail.
3763 xfs_log_force_umount(
3764 struct xfs_mount *mp,
3765 int logerror)
3767 struct xlog *log;
3768 int retval;
3770 log = mp->m_log;
3773 * If this happens during log recovery, don't worry about
3774 * locking; the log isn't open for business yet.
3776 if (!log ||
3777 log->l_flags & XLOG_ACTIVE_RECOVERY) {
3778 mp->m_flags |= XFS_MOUNT_FS_SHUTDOWN;
3779 if (mp->m_sb_bp)
3780 XFS_BUF_DONE(mp->m_sb_bp);
3781 return 0;
3785 * Somebody could've already done the hard work for us.
3786 * No need to get locks for this.
3788 if (logerror && log->l_iclog->ic_state & XLOG_STATE_IOERROR) {
3789 ASSERT(XLOG_FORCED_SHUTDOWN(log));
3790 return 1;
3792 retval = 0;
3795 * Flush the in memory commit item list before marking the log as
3796 * being shut down. We need to do it in this order to ensure all the
3797 * completed transactions are flushed to disk with the xfs_log_force()
3798 * call below.
3800 if (!logerror)
3801 xlog_cil_force(log);
3804 * mark the filesystem and the as in a shutdown state and wake
3805 * everybody up to tell them the bad news.
3807 spin_lock(&log->l_icloglock);
3808 mp->m_flags |= XFS_MOUNT_FS_SHUTDOWN;
3809 if (mp->m_sb_bp)
3810 XFS_BUF_DONE(mp->m_sb_bp);
3813 * This flag is sort of redundant because of the mount flag, but
3814 * it's good to maintain the separation between the log and the rest
3815 * of XFS.
3817 log->l_flags |= XLOG_IO_ERROR;
3820 * If we hit a log error, we want to mark all the iclogs IOERROR
3821 * while we're still holding the loglock.
3823 if (logerror)
3824 retval = xlog_state_ioerror(log);
3825 spin_unlock(&log->l_icloglock);
3828 * We don't want anybody waiting for log reservations after this. That
3829 * means we have to wake up everybody queued up on reserveq as well as
3830 * writeq. In addition, we make sure in xlog_{re}grant_log_space that
3831 * we don't enqueue anything once the SHUTDOWN flag is set, and this
3832 * action is protected by the grant locks.
3834 xlog_grant_head_wake_all(&log->l_reserve_head);
3835 xlog_grant_head_wake_all(&log->l_write_head);
3837 if (!(log->l_iclog->ic_state & XLOG_STATE_IOERROR)) {
3838 ASSERT(!logerror);
3840 * Force the incore logs to disk before shutting the
3841 * log down completely.
3843 _xfs_log_force(mp, XFS_LOG_SYNC, NULL);
3845 spin_lock(&log->l_icloglock);
3846 retval = xlog_state_ioerror(log);
3847 spin_unlock(&log->l_icloglock);
3850 * Wake up everybody waiting on xfs_log_force.
3851 * Callback all log item committed functions as if the
3852 * log writes were completed.
3854 xlog_state_do_callback(log, XFS_LI_ABORTED, NULL);
3856 #ifdef XFSERRORDEBUG
3858 xlog_in_core_t *iclog;
3860 spin_lock(&log->l_icloglock);
3861 iclog = log->l_iclog;
3862 do {
3863 ASSERT(iclog->ic_callback == 0);
3864 iclog = iclog->ic_next;
3865 } while (iclog != log->l_iclog);
3866 spin_unlock(&log->l_icloglock);
3868 #endif
3869 /* return non-zero if log IOERROR transition had already happened */
3870 return retval;
3873 STATIC int
3874 xlog_iclogs_empty(
3875 struct xlog *log)
3877 xlog_in_core_t *iclog;
3879 iclog = log->l_iclog;
3880 do {
3881 /* endianness does not matter here, zero is zero in
3882 * any language.
3884 if (iclog->ic_header.h_num_logops)
3885 return 0;
3886 iclog = iclog->ic_next;
3887 } while (iclog != log->l_iclog);
3888 return 1;