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1/*
2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3 * Copyright (C) 2004-2007 Red Hat, Inc. All rights reserved.
4 *
5 * This copyrighted material is made available to anyone wishing to use,
6 * modify, copy, or redistribute it subject to the terms and conditions
7 * of the GNU General Public License version 2.
8 */
9
10#include <linux/sched.h>
11#include <linux/slab.h>
12#include <linux/spinlock.h>
13#include <linux/completion.h>
14#include <linux/buffer_head.h>
15#include <linux/gfs2_ondisk.h>
16#include <linux/crc32.h>
17#include <linux/delay.h>
18#include <linux/kthread.h>
19#include <linux/freezer.h>
20#include <linux/bio.h>
21#include <linux/writeback.h>
22#include <linux/list_sort.h>
23
24#include "gfs2.h"
25#include "incore.h"
26#include "bmap.h"
27#include "glock.h"
28#include "log.h"
29#include "lops.h"
30#include "meta_io.h"
31#include "util.h"
32#include "dir.h"
33#include "trace_gfs2.h"
34
35/**
36 * gfs2_struct2blk - compute stuff
37 * @sdp: the filesystem
38 * @nstruct: the number of structures
39 * @ssize: the size of the structures
40 *
41 * Compute the number of log descriptor blocks needed to hold a certain number
42 * of structures of a certain size.
43 *
44 * Returns: the number of blocks needed (minimum is always 1)
45 */
46
47unsigned int gfs2_struct2blk(struct gfs2_sbd *sdp, unsigned int nstruct,
48 unsigned int ssize)
49{
50 unsigned int blks;
51 unsigned int first, second;
52
53 blks = 1;
54 first = (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_log_descriptor)) / ssize;
55
56 if (nstruct > first) {
57 second = (sdp->sd_sb.sb_bsize -
58 sizeof(struct gfs2_meta_header)) / ssize;
59 blks += DIV_ROUND_UP(nstruct - first, second);
60 }
61
62 return blks;
63}
64
65/**
66 * gfs2_remove_from_ail - Remove an entry from the ail lists, updating counters
67 * @mapping: The associated mapping (maybe NULL)
68 * @bd: The gfs2_bufdata to remove
69 *
70 * The ail lock _must_ be held when calling this function
71 *
72 */
73
74void gfs2_remove_from_ail(struct gfs2_bufdata *bd)
75{
76 bd->bd_ail = NULL;
77 list_del_init(&bd->bd_ail_st_list);
78 list_del_init(&bd->bd_ail_gl_list);
79 atomic_dec(&bd->bd_gl->gl_ail_count);
80 brelse(bd->bd_bh);
81}
82
83/**
84 * gfs2_ail1_start_one - Start I/O on a part of the AIL
85 * @sdp: the filesystem
86 * @wbc: The writeback control structure
87 * @ai: The ail structure
88 *
89 */
90
91static int gfs2_ail1_start_one(struct gfs2_sbd *sdp,
92 struct writeback_control *wbc,
93 struct gfs2_ail *ai)
94__releases(&sdp->sd_ail_lock)
95__acquires(&sdp->sd_ail_lock)
96{
97 struct gfs2_glock *gl = NULL;
98 struct address_space *mapping;
99 struct gfs2_bufdata *bd, *s;
100 struct buffer_head *bh;
101
102 list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list, bd_ail_st_list) {
103 bh = bd->bd_bh;
104
105 gfs2_assert(sdp, bd->bd_ail == ai);
106
107 if (!buffer_busy(bh)) {
108 if (!buffer_uptodate(bh))
109 gfs2_io_error_bh(sdp, bh);
110 list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list);
111 continue;
112 }
113
114 if (!buffer_dirty(bh))
115 continue;
116 if (gl == bd->bd_gl)
117 continue;
118 gl = bd->bd_gl;
119 list_move(&bd->bd_ail_st_list, &ai->ai_ail1_list);
120 mapping = bh->b_page->mapping;
121 if (!mapping)
122 continue;
123 spin_unlock(&sdp->sd_ail_lock);
124 generic_writepages(mapping, wbc);
125 spin_lock(&sdp->sd_ail_lock);
126 if (wbc->nr_to_write <= 0)
127 break;
128 return 1;
129 }
130
131 return 0;
132}
133
134
135/**
136 * gfs2_ail1_flush - start writeback of some ail1 entries
137 * @sdp: The super block
138 * @wbc: The writeback control structure
139 *
140 * Writes back some ail1 entries, according to the limits in the
141 * writeback control structure
142 */
143
144void gfs2_ail1_flush(struct gfs2_sbd *sdp, struct writeback_control *wbc)
145{
146 struct list_head *head = &sdp->sd_ail1_list;
147 struct gfs2_ail *ai;
148
149 trace_gfs2_ail_flush(sdp, wbc, 1);
150 spin_lock(&sdp->sd_ail_lock);
151restart:
152 list_for_each_entry_reverse(ai, head, ai_list) {
153 if (wbc->nr_to_write <= 0)
154 break;
155 if (gfs2_ail1_start_one(sdp, wbc, ai))
156 goto restart;
157 }
158 spin_unlock(&sdp->sd_ail_lock);
159 trace_gfs2_ail_flush(sdp, wbc, 0);
160}
161
162/**
163 * gfs2_ail1_start - start writeback of all ail1 entries
164 * @sdp: The superblock
165 */
166
167static void gfs2_ail1_start(struct gfs2_sbd *sdp)
168{
169 struct writeback_control wbc = {
170 .sync_mode = WB_SYNC_NONE,
171 .nr_to_write = LONG_MAX,
172 .range_start = 0,
173 .range_end = LLONG_MAX,
174 };
175
176 return gfs2_ail1_flush(sdp, &wbc);
177}
178
179/**
180 * gfs2_ail1_empty_one - Check whether or not a trans in the AIL has been synced
181 * @sdp: the filesystem
182 * @ai: the AIL entry
183 *
184 */
185
186static void gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
187{
188 struct gfs2_bufdata *bd, *s;
189 struct buffer_head *bh;
190
191 list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list,
192 bd_ail_st_list) {
193 bh = bd->bd_bh;
194 gfs2_assert(sdp, bd->bd_ail == ai);
195 if (buffer_busy(bh))
196 continue;
197 if (!buffer_uptodate(bh))
198 gfs2_io_error_bh(sdp, bh);
199 list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list);
200 }
201
202}
203
204/**
205 * gfs2_ail1_empty - Try to empty the ail1 lists
206 * @sdp: The superblock
207 *
208 * Tries to empty the ail1 lists, starting with the oldest first
209 */
210
211static int gfs2_ail1_empty(struct gfs2_sbd *sdp)
212{
213 struct gfs2_ail *ai, *s;
214 int ret;
215
216 spin_lock(&sdp->sd_ail_lock);
217 list_for_each_entry_safe_reverse(ai, s, &sdp->sd_ail1_list, ai_list) {
218 gfs2_ail1_empty_one(sdp, ai);
219 if (list_empty(&ai->ai_ail1_list))
220 list_move(&ai->ai_list, &sdp->sd_ail2_list);
221 else
222 break;
223 }
224 ret = list_empty(&sdp->sd_ail1_list);
225 spin_unlock(&sdp->sd_ail_lock);
226
227 return ret;
228}
229
230static void gfs2_ail1_wait(struct gfs2_sbd *sdp)
231{
232 struct gfs2_ail *ai;
233 struct gfs2_bufdata *bd;
234 struct buffer_head *bh;
235
236 spin_lock(&sdp->sd_ail_lock);
237 list_for_each_entry_reverse(ai, &sdp->sd_ail1_list, ai_list) {
238 list_for_each_entry(bd, &ai->ai_ail1_list, bd_ail_st_list) {
239 bh = bd->bd_bh;
240 if (!buffer_locked(bh))
241 continue;
242 get_bh(bh);
243 spin_unlock(&sdp->sd_ail_lock);
244 wait_on_buffer(bh);
245 brelse(bh);
246 return;
247 }
248 }
249 spin_unlock(&sdp->sd_ail_lock);
250}
251
252/**
253 * gfs2_ail2_empty_one - Check whether or not a trans in the AIL has been synced
254 * @sdp: the filesystem
255 * @ai: the AIL entry
256 *
257 */
258
259static void gfs2_ail2_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
260{
261 struct list_head *head = &ai->ai_ail2_list;
262 struct gfs2_bufdata *bd;
263
264 while (!list_empty(head)) {
265 bd = list_entry(head->prev, struct gfs2_bufdata,
266 bd_ail_st_list);
267 gfs2_assert(sdp, bd->bd_ail == ai);
268 gfs2_remove_from_ail(bd);
269 }
270}
271
272static void ail2_empty(struct gfs2_sbd *sdp, unsigned int new_tail)
273{
274 struct gfs2_ail *ai, *safe;
275 unsigned int old_tail = sdp->sd_log_tail;
276 int wrap = (new_tail < old_tail);
277 int a, b, rm;
278
279 spin_lock(&sdp->sd_ail_lock);
280
281 list_for_each_entry_safe(ai, safe, &sdp->sd_ail2_list, ai_list) {
282 a = (old_tail <= ai->ai_first);
283 b = (ai->ai_first < new_tail);
284 rm = (wrap) ? (a || b) : (a && b);
285 if (!rm)
286 continue;
287
288 gfs2_ail2_empty_one(sdp, ai);
289 list_del(&ai->ai_list);
290 gfs2_assert_warn(sdp, list_empty(&ai->ai_ail1_list));
291 gfs2_assert_warn(sdp, list_empty(&ai->ai_ail2_list));
292 kfree(ai);
293 }
294
295 spin_unlock(&sdp->sd_ail_lock);
296}
297
298/**
299 * gfs2_log_reserve - Make a log reservation
300 * @sdp: The GFS2 superblock
301 * @blks: The number of blocks to reserve
302 *
303 * Note that we never give out the last few blocks of the journal. Thats
304 * due to the fact that there is a small number of header blocks
305 * associated with each log flush. The exact number can't be known until
306 * flush time, so we ensure that we have just enough free blocks at all
307 * times to avoid running out during a log flush.
308 *
309 * We no longer flush the log here, instead we wake up logd to do that
310 * for us. To avoid the thundering herd and to ensure that we deal fairly
311 * with queued waiters, we use an exclusive wait. This means that when we
312 * get woken with enough journal space to get our reservation, we need to
313 * wake the next waiter on the list.
314 *
315 * Returns: errno
316 */
317
318int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks)
319{
320 unsigned reserved_blks = 6 * (4096 / sdp->sd_vfs->s_blocksize);
321 unsigned wanted = blks + reserved_blks;
322 DEFINE_WAIT(wait);
323 int did_wait = 0;
324 unsigned int free_blocks;
325
326 if (gfs2_assert_warn(sdp, blks) ||
327 gfs2_assert_warn(sdp, blks <= sdp->sd_jdesc->jd_blocks))
328 return -EINVAL;
329retry:
330 free_blocks = atomic_read(&sdp->sd_log_blks_free);
331 if (unlikely(free_blocks <= wanted)) {
332 do {
333 prepare_to_wait_exclusive(&sdp->sd_log_waitq, &wait,
334 TASK_UNINTERRUPTIBLE);
335 wake_up(&sdp->sd_logd_waitq);
336 did_wait = 1;
337 if (atomic_read(&sdp->sd_log_blks_free) <= wanted)
338 io_schedule();
339 free_blocks = atomic_read(&sdp->sd_log_blks_free);
340 } while(free_blocks <= wanted);
341 finish_wait(&sdp->sd_log_waitq, &wait);
342 }
343 if (atomic_cmpxchg(&sdp->sd_log_blks_free, free_blocks,
344 free_blocks - blks) != free_blocks)
345 goto retry;
346 trace_gfs2_log_blocks(sdp, -blks);
347
348 /*
349 * If we waited, then so might others, wake them up _after_ we get
350 * our share of the log.
351 */
352 if (unlikely(did_wait))
353 wake_up(&sdp->sd_log_waitq);
354
355 down_read(&sdp->sd_log_flush_lock);
356
357 return 0;
358}
359
360/**
361 * log_distance - Compute distance between two journal blocks
362 * @sdp: The GFS2 superblock
363 * @newer: The most recent journal block of the pair
364 * @older: The older journal block of the pair
365 *
366 * Compute the distance (in the journal direction) between two
367 * blocks in the journal
368 *
369 * Returns: the distance in blocks
370 */
371
372static inline unsigned int log_distance(struct gfs2_sbd *sdp, unsigned int newer,
373 unsigned int older)
374{
375 int dist;
376
377 dist = newer - older;
378 if (dist < 0)
379 dist += sdp->sd_jdesc->jd_blocks;
380
381 return dist;
382}
383
384/**
385 * calc_reserved - Calculate the number of blocks to reserve when
386 * refunding a transaction's unused buffers.
387 * @sdp: The GFS2 superblock
388 *
389 * This is complex. We need to reserve room for all our currently used
390 * metadata buffers (e.g. normal file I/O rewriting file time stamps) and
391 * all our journaled data buffers for journaled files (e.g. files in the
392 * meta_fs like rindex, or files for which chattr +j was done.)
393 * If we don't reserve enough space, gfs2_log_refund and gfs2_log_flush
394 * will count it as free space (sd_log_blks_free) and corruption will follow.
395 *
396 * We can have metadata bufs and jdata bufs in the same journal. So each
397 * type gets its own log header, for which we need to reserve a block.
398 * In fact, each type has the potential for needing more than one header
399 * in cases where we have more buffers than will fit on a journal page.
400 * Metadata journal entries take up half the space of journaled buffer entries.
401 * Thus, metadata entries have buf_limit (502) and journaled buffers have
402 * databuf_limit (251) before they cause a wrap around.
403 *
404 * Also, we need to reserve blocks for revoke journal entries and one for an
405 * overall header for the lot.
406 *
407 * Returns: the number of blocks reserved
408 */
409static unsigned int calc_reserved(struct gfs2_sbd *sdp)
410{
411 unsigned int reserved = 0;
412 unsigned int mbuf_limit, metabufhdrs_needed;
413 unsigned int dbuf_limit, databufhdrs_needed;
414 unsigned int revokes = 0;
415
416 mbuf_limit = buf_limit(sdp);
417 metabufhdrs_needed = (sdp->sd_log_commited_buf +
418 (mbuf_limit - 1)) / mbuf_limit;
419 dbuf_limit = databuf_limit(sdp);
420 databufhdrs_needed = (sdp->sd_log_commited_databuf +
421 (dbuf_limit - 1)) / dbuf_limit;
422
423 if (sdp->sd_log_commited_revoke > 0)
424 revokes = gfs2_struct2blk(sdp, sdp->sd_log_commited_revoke,
425 sizeof(u64));
426
427 reserved = sdp->sd_log_commited_buf + metabufhdrs_needed +
428 sdp->sd_log_commited_databuf + databufhdrs_needed +
429 revokes;
430 /* One for the overall header */
431 if (reserved)
432 reserved++;
433 return reserved;
434}
435
436static unsigned int current_tail(struct gfs2_sbd *sdp)
437{
438 struct gfs2_ail *ai;
439 unsigned int tail;
440
441 spin_lock(&sdp->sd_ail_lock);
442
443 if (list_empty(&sdp->sd_ail1_list)) {
444 tail = sdp->sd_log_head;
445 } else {
446 ai = list_entry(sdp->sd_ail1_list.prev, struct gfs2_ail, ai_list);
447 tail = ai->ai_first;
448 }
449
450 spin_unlock(&sdp->sd_ail_lock);
451
452 return tail;
453}
454
455static void log_pull_tail(struct gfs2_sbd *sdp, unsigned int new_tail)
456{
457 unsigned int dist = log_distance(sdp, new_tail, sdp->sd_log_tail);
458
459 ail2_empty(sdp, new_tail);
460
461 atomic_add(dist, &sdp->sd_log_blks_free);
462 trace_gfs2_log_blocks(sdp, dist);
463 gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <=
464 sdp->sd_jdesc->jd_blocks);
465
466 sdp->sd_log_tail = new_tail;
467}
468
469
470static void log_flush_wait(struct gfs2_sbd *sdp)
471{
472 DEFINE_WAIT(wait);
473
474 if (atomic_read(&sdp->sd_log_in_flight)) {
475 do {
476 prepare_to_wait(&sdp->sd_log_flush_wait, &wait,
477 TASK_UNINTERRUPTIBLE);
478 if (atomic_read(&sdp->sd_log_in_flight))
479 io_schedule();
480 } while(atomic_read(&sdp->sd_log_in_flight));
481 finish_wait(&sdp->sd_log_flush_wait, &wait);
482 }
483}
484
485static int bd_cmp(void *priv, struct list_head *a, struct list_head *b)
486{
487 struct gfs2_bufdata *bda, *bdb;
488
489 bda = list_entry(a, struct gfs2_bufdata, bd_list);
490 bdb = list_entry(b, struct gfs2_bufdata, bd_list);
491
492 if (bda->bd_bh->b_blocknr < bdb->bd_bh->b_blocknr)
493 return -1;
494 if (bda->bd_bh->b_blocknr > bdb->bd_bh->b_blocknr)
495 return 1;
496 return 0;
497}
498
499static void gfs2_ordered_write(struct gfs2_sbd *sdp)
500{
501 struct gfs2_bufdata *bd;
502 struct buffer_head *bh;
503 LIST_HEAD(written);
504
505 gfs2_log_lock(sdp);
506 list_sort(NULL, &sdp->sd_log_le_ordered, &bd_cmp);
507 while (!list_empty(&sdp->sd_log_le_ordered)) {
508 bd = list_entry(sdp->sd_log_le_ordered.next, struct gfs2_bufdata, bd_list);
509 list_move(&bd->bd_list, &written);
510 bh = bd->bd_bh;
511 if (!buffer_dirty(bh))
512 continue;
513 get_bh(bh);
514 gfs2_log_unlock(sdp);
515 lock_buffer(bh);
516 if (buffer_mapped(bh) && test_clear_buffer_dirty(bh)) {
517 bh->b_end_io = end_buffer_write_sync;
518 submit_bh(WRITE_SYNC, bh);
519 } else {
520 unlock_buffer(bh);
521 brelse(bh);
522 }
523 gfs2_log_lock(sdp);
524 }
525 list_splice(&written, &sdp->sd_log_le_ordered);
526 gfs2_log_unlock(sdp);
527}
528
529static void gfs2_ordered_wait(struct gfs2_sbd *sdp)
530{
531 struct gfs2_bufdata *bd;
532 struct buffer_head *bh;
533
534 gfs2_log_lock(sdp);
535 while (!list_empty(&sdp->sd_log_le_ordered)) {
536 bd = list_entry(sdp->sd_log_le_ordered.prev, struct gfs2_bufdata, bd_list);
537 bh = bd->bd_bh;
538 if (buffer_locked(bh)) {
539 get_bh(bh);
540 gfs2_log_unlock(sdp);
541 wait_on_buffer(bh);
542 brelse(bh);
543 gfs2_log_lock(sdp);
544 continue;
545 }
546 list_del_init(&bd->bd_list);
547 }
548 gfs2_log_unlock(sdp);
549}
550
551/**
552 * log_write_header - Get and initialize a journal header buffer
553 * @sdp: The GFS2 superblock
554 *
555 * Returns: the initialized log buffer descriptor
556 */
557
558static void log_write_header(struct gfs2_sbd *sdp, u32 flags)
559{
560 struct gfs2_log_header *lh;
561 unsigned int tail;
562 u32 hash;
563 int rw = WRITE_FLUSH_FUA | REQ_META;
564 struct page *page = mempool_alloc(gfs2_page_pool, GFP_NOIO);
565 lh = page_address(page);
566 clear_page(lh);
567
568 gfs2_ail1_empty(sdp);
569 tail = current_tail(sdp);
570
571 lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
572 lh->lh_header.mh_type = cpu_to_be32(GFS2_METATYPE_LH);
573 lh->lh_header.__pad0 = cpu_to_be64(0);
574 lh->lh_header.mh_format = cpu_to_be32(GFS2_FORMAT_LH);
575 lh->lh_header.mh_jid = cpu_to_be32(sdp->sd_jdesc->jd_jid);
576 lh->lh_sequence = cpu_to_be64(sdp->sd_log_sequence++);
577 lh->lh_flags = cpu_to_be32(flags);
578 lh->lh_tail = cpu_to_be32(tail);
579 lh->lh_blkno = cpu_to_be32(sdp->sd_log_flush_head);
580 hash = gfs2_disk_hash(page_address(page), sizeof(struct gfs2_log_header));
581 lh->lh_hash = cpu_to_be32(hash);
582
583 if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags)) {
584 gfs2_ordered_wait(sdp);
585 log_flush_wait(sdp);
586 rw = WRITE_SYNC | REQ_META | REQ_PRIO;
587 }
588
589 sdp->sd_log_idle = (tail == sdp->sd_log_flush_head);
590 gfs2_log_write_page(sdp, page);
591 gfs2_log_flush_bio(sdp, rw);
592 log_flush_wait(sdp);
593
594 if (sdp->sd_log_tail != tail)
595 log_pull_tail(sdp, tail);
596}
597
598/**
599 * gfs2_log_flush - flush incore transaction(s)
600 * @sdp: the filesystem
601 * @gl: The glock structure to flush. If NULL, flush the whole incore log
602 *
603 */
604
605void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl)
606{
607 struct gfs2_ail *ai;
608
609 down_write(&sdp->sd_log_flush_lock);
610
611 /* Log might have been flushed while we waited for the flush lock */
612 if (gl && !test_bit(GLF_LFLUSH, &gl->gl_flags)) {
613 up_write(&sdp->sd_log_flush_lock);
614 return;
615 }
616 trace_gfs2_log_flush(sdp, 1);
617
618 ai = kzalloc(sizeof(struct gfs2_ail), GFP_NOFS | __GFP_NOFAIL);
619 INIT_LIST_HEAD(&ai->ai_ail1_list);
620 INIT_LIST_HEAD(&ai->ai_ail2_list);
621
622 if (sdp->sd_log_num_buf != sdp->sd_log_commited_buf) {
623 printk(KERN_INFO "GFS2: log buf %u %u\n", sdp->sd_log_num_buf,
624 sdp->sd_log_commited_buf);
625 gfs2_assert_withdraw(sdp, 0);
626 }
627 if (sdp->sd_log_num_databuf != sdp->sd_log_commited_databuf) {
628 printk(KERN_INFO "GFS2: log databuf %u %u\n",
629 sdp->sd_log_num_databuf, sdp->sd_log_commited_databuf);
630 gfs2_assert_withdraw(sdp, 0);
631 }
632 gfs2_assert_withdraw(sdp,
633 sdp->sd_log_num_revoke == sdp->sd_log_commited_revoke);
634
635 sdp->sd_log_flush_head = sdp->sd_log_head;
636 sdp->sd_log_flush_wrapped = 0;
637 ai->ai_first = sdp->sd_log_flush_head;
638
639 gfs2_ordered_write(sdp);
640 lops_before_commit(sdp);
641 gfs2_log_flush_bio(sdp, WRITE);
642
643 if (sdp->sd_log_head != sdp->sd_log_flush_head) {
644 log_write_header(sdp, 0);
645 } else if (sdp->sd_log_tail != current_tail(sdp) && !sdp->sd_log_idle){
646 atomic_dec(&sdp->sd_log_blks_free); /* Adjust for unreserved buffer */
647 trace_gfs2_log_blocks(sdp, -1);
648 log_write_header(sdp, 0);
649 }
650 lops_after_commit(sdp, ai);
651
652 gfs2_log_lock(sdp);
653 sdp->sd_log_head = sdp->sd_log_flush_head;
654 sdp->sd_log_blks_reserved = 0;
655 sdp->sd_log_commited_buf = 0;
656 sdp->sd_log_commited_databuf = 0;
657 sdp->sd_log_commited_revoke = 0;
658
659 spin_lock(&sdp->sd_ail_lock);
660 if (!list_empty(&ai->ai_ail1_list)) {
661 list_add(&ai->ai_list, &sdp->sd_ail1_list);
662 ai = NULL;
663 }
664 spin_unlock(&sdp->sd_ail_lock);
665 gfs2_log_unlock(sdp);
666 trace_gfs2_log_flush(sdp, 0);
667 up_write(&sdp->sd_log_flush_lock);
668
669 kfree(ai);
670}
671
672static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
673{
674 unsigned int reserved;
675 unsigned int unused;
676
677 gfs2_log_lock(sdp);
678
679 sdp->sd_log_commited_buf += tr->tr_num_buf_new - tr->tr_num_buf_rm;
680 sdp->sd_log_commited_databuf += tr->tr_num_databuf_new -
681 tr->tr_num_databuf_rm;
682 gfs2_assert_withdraw(sdp, (((int)sdp->sd_log_commited_buf) >= 0) ||
683 (((int)sdp->sd_log_commited_databuf) >= 0));
684 sdp->sd_log_commited_revoke += tr->tr_num_revoke - tr->tr_num_revoke_rm;
685 reserved = calc_reserved(sdp);
686 gfs2_assert_withdraw(sdp, sdp->sd_log_blks_reserved + tr->tr_reserved >= reserved);
687 unused = sdp->sd_log_blks_reserved - reserved + tr->tr_reserved;
688 atomic_add(unused, &sdp->sd_log_blks_free);
689 trace_gfs2_log_blocks(sdp, unused);
690 gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <=
691 sdp->sd_jdesc->jd_blocks);
692 sdp->sd_log_blks_reserved = reserved;
693
694 gfs2_log_unlock(sdp);
695}
696
697/**
698 * gfs2_log_commit - Commit a transaction to the log
699 * @sdp: the filesystem
700 * @tr: the transaction
701 *
702 * We wake up gfs2_logd if the number of pinned blocks exceed thresh1
703 * or the total number of used blocks (pinned blocks plus AIL blocks)
704 * is greater than thresh2.
705 *
706 * At mount time thresh1 is 1/3rd of journal size, thresh2 is 2/3rd of
707 * journal size.
708 *
709 * Returns: errno
710 */
711
712void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
713{
714 log_refund(sdp, tr);
715 up_read(&sdp->sd_log_flush_lock);
716
717 if (atomic_read(&sdp->sd_log_pinned) > atomic_read(&sdp->sd_log_thresh1) ||
718 ((sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free)) >
719 atomic_read(&sdp->sd_log_thresh2)))
720 wake_up(&sdp->sd_logd_waitq);
721}
722
723/**
724 * gfs2_log_shutdown - write a shutdown header into a journal
725 * @sdp: the filesystem
726 *
727 */
728
729void gfs2_log_shutdown(struct gfs2_sbd *sdp)
730{
731 down_write(&sdp->sd_log_flush_lock);
732
733 gfs2_assert_withdraw(sdp, !sdp->sd_log_blks_reserved);
734 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_buf);
735 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke);
736 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_rg);
737 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_databuf);
738 gfs2_assert_withdraw(sdp, list_empty(&sdp->sd_ail1_list));
739
740 sdp->sd_log_flush_head = sdp->sd_log_head;
741 sdp->sd_log_flush_wrapped = 0;
742
743 log_write_header(sdp, GFS2_LOG_HEAD_UNMOUNT);
744
745 gfs2_assert_warn(sdp, atomic_read(&sdp->sd_log_blks_free) == sdp->sd_jdesc->jd_blocks);
746 gfs2_assert_warn(sdp, sdp->sd_log_head == sdp->sd_log_tail);
747 gfs2_assert_warn(sdp, list_empty(&sdp->sd_ail2_list));
748
749 sdp->sd_log_head = sdp->sd_log_flush_head;
750 sdp->sd_log_tail = sdp->sd_log_head;
751
752 up_write(&sdp->sd_log_flush_lock);
753}
754
755
756/**
757 * gfs2_meta_syncfs - sync all the buffers in a filesystem
758 * @sdp: the filesystem
759 *
760 */
761
762void gfs2_meta_syncfs(struct gfs2_sbd *sdp)
763{
764 gfs2_log_flush(sdp, NULL);
765 for (;;) {
766 gfs2_ail1_start(sdp);
767 gfs2_ail1_wait(sdp);
768 if (gfs2_ail1_empty(sdp))
769 break;
770 }
771 gfs2_log_flush(sdp, NULL);
772}
773
774static inline int gfs2_jrnl_flush_reqd(struct gfs2_sbd *sdp)
775{
776 return (atomic_read(&sdp->sd_log_pinned) >= atomic_read(&sdp->sd_log_thresh1));
777}
778
779static inline int gfs2_ail_flush_reqd(struct gfs2_sbd *sdp)
780{
781 unsigned int used_blocks = sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free);
782 return used_blocks >= atomic_read(&sdp->sd_log_thresh2);
783}
784
785/**
786 * gfs2_logd - Update log tail as Active Items get flushed to in-place blocks
787 * @sdp: Pointer to GFS2 superblock
788 *
789 * Also, periodically check to make sure that we're using the most recent
790 * journal index.
791 */
792
793int gfs2_logd(void *data)
794{
795 struct gfs2_sbd *sdp = data;
796 unsigned long t = 1;
797 DEFINE_WAIT(wait);
798
799 while (!kthread_should_stop()) {
800
801 if (gfs2_jrnl_flush_reqd(sdp) || t == 0) {
802 gfs2_ail1_empty(sdp);
803 gfs2_log_flush(sdp, NULL);
804 }
805
806 if (gfs2_ail_flush_reqd(sdp)) {
807 gfs2_ail1_start(sdp);
808 gfs2_ail1_wait(sdp);
809 gfs2_ail1_empty(sdp);
810 gfs2_log_flush(sdp, NULL);
811 }
812
813 if (!gfs2_ail_flush_reqd(sdp))
814 wake_up(&sdp->sd_log_waitq);
815
816 t = gfs2_tune_get(sdp, gt_logd_secs) * HZ;
817
818 try_to_freeze();
819
820 do {
821 prepare_to_wait(&sdp->sd_logd_waitq, &wait,
822 TASK_INTERRUPTIBLE);
823 if (!gfs2_ail_flush_reqd(sdp) &&
824 !gfs2_jrnl_flush_reqd(sdp) &&
825 !kthread_should_stop())
826 t = schedule_timeout(t);
827 } while(t && !gfs2_ail_flush_reqd(sdp) &&
828 !gfs2_jrnl_flush_reqd(sdp) &&
829 !kthread_should_stop());
830 finish_wait(&sdp->sd_logd_waitq, &wait);
831 }
832
833 return 0;
834}
835