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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
23#include "gfs2.h"
24#include "incore.h"
25#include "bmap.h"
26#include "glock.h"
27#include "log.h"
28#include "lops.h"
29#include "meta_io.h"
30#include "util.h"
31#include "dir.h"
32#include "trace_gfs2.h"
33
34#define PULL 1
35
36/**
37 * gfs2_struct2blk - compute stuff
38 * @sdp: the filesystem
39 * @nstruct: the number of structures
40 * @ssize: the size of the structures
41 *
42 * Compute the number of log descriptor blocks needed to hold a certain number
43 * of structures of a certain size.
44 *
45 * Returns: the number of blocks needed (minimum is always 1)
46 */
47
48unsigned int gfs2_struct2blk(struct gfs2_sbd *sdp, unsigned int nstruct,
49 unsigned int ssize)
50{
51 unsigned int blks;
52 unsigned int first, second;
53
54 blks = 1;
55 first = (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_log_descriptor)) / ssize;
56
57 if (nstruct > first) {
58 second = (sdp->sd_sb.sb_bsize -
59 sizeof(struct gfs2_meta_header)) / ssize;
60 blks += DIV_ROUND_UP(nstruct - first, second);
61 }
62
63 return blks;
64}
65
66/**
67 * gfs2_remove_from_ail - Remove an entry from the ail lists, updating counters
68 * @mapping: The associated mapping (maybe NULL)
69 * @bd: The gfs2_bufdata to remove
70 *
71 * The ail lock _must_ be held when calling this function
72 *
73 */
74
75void gfs2_remove_from_ail(struct gfs2_bufdata *bd)
76{
77 bd->bd_ail = NULL;
78 list_del_init(&bd->bd_ail_st_list);
79 list_del_init(&bd->bd_ail_gl_list);
80 atomic_dec(&bd->bd_gl->gl_ail_count);
81 brelse(bd->bd_bh);
82}
83
84/**
85 * gfs2_ail1_start_one - Start I/O on a part of the AIL
86 * @sdp: the filesystem
87 * @wbc: The writeback control structure
88 * @ai: The ail structure
89 *
90 */
91
92static int gfs2_ail1_start_one(struct gfs2_sbd *sdp,
93 struct writeback_control *wbc,
94 struct gfs2_ail *ai)
95__releases(&sdp->sd_ail_lock)
96__acquires(&sdp->sd_ail_lock)
97{
98 struct gfs2_glock *gl = NULL;
99 struct address_space *mapping;
100 struct gfs2_bufdata *bd, *s;
101 struct buffer_head *bh;
102
103 list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list, bd_ail_st_list) {
104 bh = bd->bd_bh;
105
106 gfs2_assert(sdp, bd->bd_ail == ai);
107
108 if (!buffer_busy(bh)) {
109 if (!buffer_uptodate(bh))
110 gfs2_io_error_bh(sdp, bh);
111 list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list);
112 continue;
113 }
114
115 if (!buffer_dirty(bh))
116 continue;
117 if (gl == bd->bd_gl)
118 continue;
119 gl = bd->bd_gl;
120 list_move(&bd->bd_ail_st_list, &ai->ai_ail1_list);
121 mapping = bh->b_page->mapping;
122 if (!mapping)
123 continue;
124 spin_unlock(&sdp->sd_ail_lock);
125 generic_writepages(mapping, wbc);
126 spin_lock(&sdp->sd_ail_lock);
127 if (wbc->nr_to_write <= 0)
128 break;
129 return 1;
130 }
131
132 return 0;
133}
134
135
136/**
137 * gfs2_ail1_flush - start writeback of some ail1 entries
138 * @sdp: The super block
139 * @wbc: The writeback control structure
140 *
141 * Writes back some ail1 entries, according to the limits in the
142 * writeback control structure
143 */
144
145void gfs2_ail1_flush(struct gfs2_sbd *sdp, struct writeback_control *wbc)
146{
147 struct list_head *head = &sdp->sd_ail1_list;
148 struct gfs2_ail *ai;
149
150 trace_gfs2_ail_flush(sdp, wbc, 1);
151 spin_lock(&sdp->sd_ail_lock);
152restart:
153 list_for_each_entry_reverse(ai, head, ai_list) {
154 if (wbc->nr_to_write <= 0)
155 break;
156 if (gfs2_ail1_start_one(sdp, wbc, ai))
157 goto restart;
158 }
159 spin_unlock(&sdp->sd_ail_lock);
160 trace_gfs2_ail_flush(sdp, wbc, 0);
161}
162
163/**
164 * gfs2_ail1_start - start writeback of all ail1 entries
165 * @sdp: The superblock
166 */
167
168static void gfs2_ail1_start(struct gfs2_sbd *sdp)
169{
170 struct writeback_control wbc = {
171 .sync_mode = WB_SYNC_NONE,
172 .nr_to_write = LONG_MAX,
173 .range_start = 0,
174 .range_end = LLONG_MAX,
175 };
176
177 return gfs2_ail1_flush(sdp, &wbc);
178}
179
180/**
181 * gfs2_ail1_empty_one - Check whether or not a trans in the AIL has been synced
182 * @sdp: the filesystem
183 * @ai: the AIL entry
184 *
185 */
186
187static void gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
188{
189 struct gfs2_bufdata *bd, *s;
190 struct buffer_head *bh;
191
192 list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list,
193 bd_ail_st_list) {
194 bh = bd->bd_bh;
195 gfs2_assert(sdp, bd->bd_ail == ai);
196 if (buffer_busy(bh))
197 continue;
198 if (!buffer_uptodate(bh))
199 gfs2_io_error_bh(sdp, bh);
200 list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list);
201 }
202
203}
204
205/**
206 * gfs2_ail1_empty - Try to empty the ail1 lists
207 * @sdp: The superblock
208 *
209 * Tries to empty the ail1 lists, starting with the oldest first
210 */
211
212static int gfs2_ail1_empty(struct gfs2_sbd *sdp)
213{
214 struct gfs2_ail *ai, *s;
215 int ret;
216
217 spin_lock(&sdp->sd_ail_lock);
218 list_for_each_entry_safe_reverse(ai, s, &sdp->sd_ail1_list, ai_list) {
219 gfs2_ail1_empty_one(sdp, ai);
220 if (list_empty(&ai->ai_ail1_list))
221 list_move(&ai->ai_list, &sdp->sd_ail2_list);
222 else
223 break;
224 }
225 ret = list_empty(&sdp->sd_ail1_list);
226 spin_unlock(&sdp->sd_ail_lock);
227
228 return ret;
229}
230
231static void gfs2_ail1_wait(struct gfs2_sbd *sdp)
232{
233 struct gfs2_ail *ai;
234 struct gfs2_bufdata *bd;
235 struct buffer_head *bh;
236
237 spin_lock(&sdp->sd_ail_lock);
238 list_for_each_entry_reverse(ai, &sdp->sd_ail1_list, ai_list) {
239 list_for_each_entry(bd, &ai->ai_ail1_list, bd_ail_st_list) {
240 bh = bd->bd_bh;
241 if (!buffer_locked(bh))
242 continue;
243 get_bh(bh);
244 spin_unlock(&sdp->sd_ail_lock);
245 wait_on_buffer(bh);
246 brelse(bh);
247 return;
248 }
249 }
250 spin_unlock(&sdp->sd_ail_lock);
251}
252
253/**
254 * gfs2_ail2_empty_one - Check whether or not a trans in the AIL has been synced
255 * @sdp: the filesystem
256 * @ai: the AIL entry
257 *
258 */
259
260static void gfs2_ail2_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
261{
262 struct list_head *head = &ai->ai_ail2_list;
263 struct gfs2_bufdata *bd;
264
265 while (!list_empty(head)) {
266 bd = list_entry(head->prev, struct gfs2_bufdata,
267 bd_ail_st_list);
268 gfs2_assert(sdp, bd->bd_ail == ai);
269 gfs2_remove_from_ail(bd);
270 }
271}
272
273static void ail2_empty(struct gfs2_sbd *sdp, unsigned int new_tail)
274{
275 struct gfs2_ail *ai, *safe;
276 unsigned int old_tail = sdp->sd_log_tail;
277 int wrap = (new_tail < old_tail);
278 int a, b, rm;
279
280 spin_lock(&sdp->sd_ail_lock);
281
282 list_for_each_entry_safe(ai, safe, &sdp->sd_ail2_list, ai_list) {
283 a = (old_tail <= ai->ai_first);
284 b = (ai->ai_first < new_tail);
285 rm = (wrap) ? (a || b) : (a && b);
286 if (!rm)
287 continue;
288
289 gfs2_ail2_empty_one(sdp, ai);
290 list_del(&ai->ai_list);
291 gfs2_assert_warn(sdp, list_empty(&ai->ai_ail1_list));
292 gfs2_assert_warn(sdp, list_empty(&ai->ai_ail2_list));
293 kfree(ai);
294 }
295
296 spin_unlock(&sdp->sd_ail_lock);
297}
298
299/**
300 * gfs2_log_reserve - Make a log reservation
301 * @sdp: The GFS2 superblock
302 * @blks: The number of blocks to reserve
303 *
304 * Note that we never give out the last few blocks of the journal. Thats
305 * due to the fact that there is a small number of header blocks
306 * associated with each log flush. The exact number can't be known until
307 * flush time, so we ensure that we have just enough free blocks at all
308 * times to avoid running out during a log flush.
309 *
310 * We no longer flush the log here, instead we wake up logd to do that
311 * for us. To avoid the thundering herd and to ensure that we deal fairly
312 * with queued waiters, we use an exclusive wait. This means that when we
313 * get woken with enough journal space to get our reservation, we need to
314 * wake the next waiter on the list.
315 *
316 * Returns: errno
317 */
318
319int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks)
320{
321 unsigned reserved_blks = 6 * (4096 / sdp->sd_vfs->s_blocksize);
322 unsigned wanted = blks + reserved_blks;
323 DEFINE_WAIT(wait);
324 int did_wait = 0;
325 unsigned int free_blocks;
326
327 if (gfs2_assert_warn(sdp, blks) ||
328 gfs2_assert_warn(sdp, blks <= sdp->sd_jdesc->jd_blocks))
329 return -EINVAL;
330retry:
331 free_blocks = atomic_read(&sdp->sd_log_blks_free);
332 if (unlikely(free_blocks <= wanted)) {
333 do {
334 prepare_to_wait_exclusive(&sdp->sd_log_waitq, &wait,
335 TASK_UNINTERRUPTIBLE);
336 wake_up(&sdp->sd_logd_waitq);
337 did_wait = 1;
338 if (atomic_read(&sdp->sd_log_blks_free) <= wanted)
339 io_schedule();
340 free_blocks = atomic_read(&sdp->sd_log_blks_free);
341 } while(free_blocks <= wanted);
342 finish_wait(&sdp->sd_log_waitq, &wait);
343 }
344 if (atomic_cmpxchg(&sdp->sd_log_blks_free, free_blocks,
345 free_blocks - blks) != free_blocks)
346 goto retry;
347 trace_gfs2_log_blocks(sdp, -blks);
348
349 /*
350 * If we waited, then so might others, wake them up _after_ we get
351 * our share of the log.
352 */
353 if (unlikely(did_wait))
354 wake_up(&sdp->sd_log_waitq);
355
356 down_read(&sdp->sd_log_flush_lock);
357
358 return 0;
359}
360
361static u64 log_bmap(struct gfs2_sbd *sdp, unsigned int lbn)
362{
363 struct gfs2_journal_extent *je;
364
365 list_for_each_entry(je, &sdp->sd_jdesc->extent_list, extent_list) {
366 if (lbn >= je->lblock && lbn < je->lblock + je->blocks)
367 return je->dblock + lbn - je->lblock;
368 }
369
370 return -1;
371}
372
373/**
374 * log_distance - Compute distance between two journal blocks
375 * @sdp: The GFS2 superblock
376 * @newer: The most recent journal block of the pair
377 * @older: The older journal block of the pair
378 *
379 * Compute the distance (in the journal direction) between two
380 * blocks in the journal
381 *
382 * Returns: the distance in blocks
383 */
384
385static inline unsigned int log_distance(struct gfs2_sbd *sdp, unsigned int newer,
386 unsigned int older)
387{
388 int dist;
389
390 dist = newer - older;
391 if (dist < 0)
392 dist += sdp->sd_jdesc->jd_blocks;
393
394 return dist;
395}
396
397/**
398 * calc_reserved - Calculate the number of blocks to reserve when
399 * refunding a transaction's unused buffers.
400 * @sdp: The GFS2 superblock
401 *
402 * This is complex. We need to reserve room for all our currently used
403 * metadata buffers (e.g. normal file I/O rewriting file time stamps) and
404 * all our journaled data buffers for journaled files (e.g. files in the
405 * meta_fs like rindex, or files for which chattr +j was done.)
406 * If we don't reserve enough space, gfs2_log_refund and gfs2_log_flush
407 * will count it as free space (sd_log_blks_free) and corruption will follow.
408 *
409 * We can have metadata bufs and jdata bufs in the same journal. So each
410 * type gets its own log header, for which we need to reserve a block.
411 * In fact, each type has the potential for needing more than one header
412 * in cases where we have more buffers than will fit on a journal page.
413 * Metadata journal entries take up half the space of journaled buffer entries.
414 * Thus, metadata entries have buf_limit (502) and journaled buffers have
415 * databuf_limit (251) before they cause a wrap around.
416 *
417 * Also, we need to reserve blocks for revoke journal entries and one for an
418 * overall header for the lot.
419 *
420 * Returns: the number of blocks reserved
421 */
422static unsigned int calc_reserved(struct gfs2_sbd *sdp)
423{
424 unsigned int reserved = 0;
425 unsigned int mbuf_limit, metabufhdrs_needed;
426 unsigned int dbuf_limit, databufhdrs_needed;
427 unsigned int revokes = 0;
428
429 mbuf_limit = buf_limit(sdp);
430 metabufhdrs_needed = (sdp->sd_log_commited_buf +
431 (mbuf_limit - 1)) / mbuf_limit;
432 dbuf_limit = databuf_limit(sdp);
433 databufhdrs_needed = (sdp->sd_log_commited_databuf +
434 (dbuf_limit - 1)) / dbuf_limit;
435
436 if (sdp->sd_log_commited_revoke > 0)
437 revokes = gfs2_struct2blk(sdp, sdp->sd_log_commited_revoke,
438 sizeof(u64));
439
440 reserved = sdp->sd_log_commited_buf + metabufhdrs_needed +
441 sdp->sd_log_commited_databuf + databufhdrs_needed +
442 revokes;
443 /* One for the overall header */
444 if (reserved)
445 reserved++;
446 return reserved;
447}
448
449static unsigned int current_tail(struct gfs2_sbd *sdp)
450{
451 struct gfs2_ail *ai;
452 unsigned int tail;
453
454 spin_lock(&sdp->sd_ail_lock);
455
456 if (list_empty(&sdp->sd_ail1_list)) {
457 tail = sdp->sd_log_head;
458 } else {
459 ai = list_entry(sdp->sd_ail1_list.prev, struct gfs2_ail, ai_list);
460 tail = ai->ai_first;
461 }
462
463 spin_unlock(&sdp->sd_ail_lock);
464
465 return tail;
466}
467
468void gfs2_log_incr_head(struct gfs2_sbd *sdp)
469{
470 if (sdp->sd_log_flush_head == sdp->sd_log_tail)
471 BUG_ON(sdp->sd_log_flush_head != sdp->sd_log_head);
472
473 if (++sdp->sd_log_flush_head == sdp->sd_jdesc->jd_blocks) {
474 sdp->sd_log_flush_head = 0;
475 sdp->sd_log_flush_wrapped = 1;
476 }
477}
478
479/**
480 * gfs2_log_write_endio - End of I/O for a log buffer
481 * @bh: The buffer head
482 * @uptodate: I/O Status
483 *
484 */
485
486static void gfs2_log_write_endio(struct buffer_head *bh, int uptodate)
487{
488 struct gfs2_sbd *sdp = bh->b_private;
489 bh->b_private = NULL;
490
491 end_buffer_write_sync(bh, uptodate);
492 if (atomic_dec_and_test(&sdp->sd_log_in_flight))
493 wake_up(&sdp->sd_log_flush_wait);
494}
495
496/**
497 * gfs2_log_get_buf - Get and initialize a buffer to use for log control data
498 * @sdp: The GFS2 superblock
499 *
500 * Returns: the buffer_head
501 */
502
503struct buffer_head *gfs2_log_get_buf(struct gfs2_sbd *sdp)
504{
505 u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head);
506 struct buffer_head *bh;
507
508 bh = sb_getblk(sdp->sd_vfs, blkno);
509 lock_buffer(bh);
510 memset(bh->b_data, 0, bh->b_size);
511 set_buffer_uptodate(bh);
512 clear_buffer_dirty(bh);
513 gfs2_log_incr_head(sdp);
514 atomic_inc(&sdp->sd_log_in_flight);
515 bh->b_private = sdp;
516 bh->b_end_io = gfs2_log_write_endio;
517
518 return bh;
519}
520
521/**
522 * gfs2_fake_write_endio -
523 * @bh: The buffer head
524 * @uptodate: The I/O Status
525 *
526 */
527
528static void gfs2_fake_write_endio(struct buffer_head *bh, int uptodate)
529{
530 struct buffer_head *real_bh = bh->b_private;
531 struct gfs2_bufdata *bd = real_bh->b_private;
532 struct gfs2_sbd *sdp = bd->bd_gl->gl_sbd;
533
534 end_buffer_write_sync(bh, uptodate);
535 free_buffer_head(bh);
536 unlock_buffer(real_bh);
537 brelse(real_bh);
538 if (atomic_dec_and_test(&sdp->sd_log_in_flight))
539 wake_up(&sdp->sd_log_flush_wait);
540}
541
542/**
543 * gfs2_log_fake_buf - Build a fake buffer head to write metadata buffer to log
544 * @sdp: the filesystem
545 * @data: the data the buffer_head should point to
546 *
547 * Returns: the log buffer descriptor
548 */
549
550struct buffer_head *gfs2_log_fake_buf(struct gfs2_sbd *sdp,
551 struct buffer_head *real)
552{
553 u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head);
554 struct buffer_head *bh;
555
556 bh = alloc_buffer_head(GFP_NOFS | __GFP_NOFAIL);
557 atomic_set(&bh->b_count, 1);
558 bh->b_state = (1 << BH_Mapped) | (1 << BH_Uptodate) | (1 << BH_Lock);
559 set_bh_page(bh, real->b_page, bh_offset(real));
560 bh->b_blocknr = blkno;
561 bh->b_size = sdp->sd_sb.sb_bsize;
562 bh->b_bdev = sdp->sd_vfs->s_bdev;
563 bh->b_private = real;
564 bh->b_end_io = gfs2_fake_write_endio;
565
566 gfs2_log_incr_head(sdp);
567 atomic_inc(&sdp->sd_log_in_flight);
568
569 return bh;
570}
571
572static void log_pull_tail(struct gfs2_sbd *sdp, unsigned int new_tail)
573{
574 unsigned int dist = log_distance(sdp, new_tail, sdp->sd_log_tail);
575
576 ail2_empty(sdp, new_tail);
577
578 atomic_add(dist, &sdp->sd_log_blks_free);
579 trace_gfs2_log_blocks(sdp, dist);
580 gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <=
581 sdp->sd_jdesc->jd_blocks);
582
583 sdp->sd_log_tail = new_tail;
584}
585
586/**
587 * log_write_header - Get and initialize a journal header buffer
588 * @sdp: The GFS2 superblock
589 *
590 * Returns: the initialized log buffer descriptor
591 */
592
593static void log_write_header(struct gfs2_sbd *sdp, u32 flags, int pull)
594{
595 u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head);
596 struct buffer_head *bh;
597 struct gfs2_log_header *lh;
598 unsigned int tail;
599 u32 hash;
600
601 bh = sb_getblk(sdp->sd_vfs, blkno);
602 lock_buffer(bh);
603 memset(bh->b_data, 0, bh->b_size);
604 set_buffer_uptodate(bh);
605 clear_buffer_dirty(bh);
606
607 gfs2_ail1_empty(sdp);
608 tail = current_tail(sdp);
609
610 lh = (struct gfs2_log_header *)bh->b_data;
611 memset(lh, 0, sizeof(struct gfs2_log_header));
612 lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
613 lh->lh_header.mh_type = cpu_to_be32(GFS2_METATYPE_LH);
614 lh->lh_header.__pad0 = cpu_to_be64(0);
615 lh->lh_header.mh_format = cpu_to_be32(GFS2_FORMAT_LH);
616 lh->lh_header.mh_jid = cpu_to_be32(sdp->sd_jdesc->jd_jid);
617 lh->lh_sequence = cpu_to_be64(sdp->sd_log_sequence++);
618 lh->lh_flags = cpu_to_be32(flags);
619 lh->lh_tail = cpu_to_be32(tail);
620 lh->lh_blkno = cpu_to_be32(sdp->sd_log_flush_head);
621 hash = gfs2_disk_hash(bh->b_data, sizeof(struct gfs2_log_header));
622 lh->lh_hash = cpu_to_be32(hash);
623
624 bh->b_end_io = end_buffer_write_sync;
625 get_bh(bh);
626 if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags))
627 submit_bh(WRITE_SYNC | REQ_META | REQ_PRIO, bh);
628 else
629 submit_bh(WRITE_FLUSH_FUA | REQ_META | REQ_PRIO, bh);
630 wait_on_buffer(bh);
631
632 if (!buffer_uptodate(bh))
633 gfs2_io_error_bh(sdp, bh);
634 brelse(bh);
635
636 if (sdp->sd_log_tail != tail)
637 log_pull_tail(sdp, tail);
638 else
639 gfs2_assert_withdraw(sdp, !pull);
640
641 sdp->sd_log_idle = (tail == sdp->sd_log_flush_head);
642 gfs2_log_incr_head(sdp);
643}
644
645static void log_flush_commit(struct gfs2_sbd *sdp)
646{
647 DEFINE_WAIT(wait);
648
649 if (atomic_read(&sdp->sd_log_in_flight)) {
650 do {
651 prepare_to_wait(&sdp->sd_log_flush_wait, &wait,
652 TASK_UNINTERRUPTIBLE);
653 if (atomic_read(&sdp->sd_log_in_flight))
654 io_schedule();
655 } while(atomic_read(&sdp->sd_log_in_flight));
656 finish_wait(&sdp->sd_log_flush_wait, &wait);
657 }
658
659 log_write_header(sdp, 0, 0);
660}
661
662static void gfs2_ordered_write(struct gfs2_sbd *sdp)
663{
664 struct gfs2_bufdata *bd;
665 struct buffer_head *bh;
666 LIST_HEAD(written);
667
668 gfs2_log_lock(sdp);
669 while (!list_empty(&sdp->sd_log_le_ordered)) {
670 bd = list_entry(sdp->sd_log_le_ordered.next, struct gfs2_bufdata, bd_le.le_list);
671 list_move(&bd->bd_le.le_list, &written);
672 bh = bd->bd_bh;
673 if (!buffer_dirty(bh))
674 continue;
675 get_bh(bh);
676 gfs2_log_unlock(sdp);
677 lock_buffer(bh);
678 if (buffer_mapped(bh) && test_clear_buffer_dirty(bh)) {
679 bh->b_end_io = end_buffer_write_sync;
680 submit_bh(WRITE_SYNC, bh);
681 } else {
682 unlock_buffer(bh);
683 brelse(bh);
684 }
685 gfs2_log_lock(sdp);
686 }
687 list_splice(&written, &sdp->sd_log_le_ordered);
688 gfs2_log_unlock(sdp);
689}
690
691static void gfs2_ordered_wait(struct gfs2_sbd *sdp)
692{
693 struct gfs2_bufdata *bd;
694 struct buffer_head *bh;
695
696 gfs2_log_lock(sdp);
697 while (!list_empty(&sdp->sd_log_le_ordered)) {
698 bd = list_entry(sdp->sd_log_le_ordered.prev, struct gfs2_bufdata, bd_le.le_list);
699 bh = bd->bd_bh;
700 if (buffer_locked(bh)) {
701 get_bh(bh);
702 gfs2_log_unlock(sdp);
703 wait_on_buffer(bh);
704 brelse(bh);
705 gfs2_log_lock(sdp);
706 continue;
707 }
708 list_del_init(&bd->bd_le.le_list);
709 }
710 gfs2_log_unlock(sdp);
711}
712
713/**
714 * gfs2_log_flush - flush incore transaction(s)
715 * @sdp: the filesystem
716 * @gl: The glock structure to flush. If NULL, flush the whole incore log
717 *
718 */
719
720void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl)
721{
722 struct gfs2_ail *ai;
723
724 down_write(&sdp->sd_log_flush_lock);
725
726 /* Log might have been flushed while we waited for the flush lock */
727 if (gl && !test_bit(GLF_LFLUSH, &gl->gl_flags)) {
728 up_write(&sdp->sd_log_flush_lock);
729 return;
730 }
731 trace_gfs2_log_flush(sdp, 1);
732
733 ai = kzalloc(sizeof(struct gfs2_ail), GFP_NOFS | __GFP_NOFAIL);
734 INIT_LIST_HEAD(&ai->ai_ail1_list);
735 INIT_LIST_HEAD(&ai->ai_ail2_list);
736
737 if (sdp->sd_log_num_buf != sdp->sd_log_commited_buf) {
738 printk(KERN_INFO "GFS2: log buf %u %u\n", sdp->sd_log_num_buf,
739 sdp->sd_log_commited_buf);
740 gfs2_assert_withdraw(sdp, 0);
741 }
742 if (sdp->sd_log_num_databuf != sdp->sd_log_commited_databuf) {
743 printk(KERN_INFO "GFS2: log databuf %u %u\n",
744 sdp->sd_log_num_databuf, sdp->sd_log_commited_databuf);
745 gfs2_assert_withdraw(sdp, 0);
746 }
747 gfs2_assert_withdraw(sdp,
748 sdp->sd_log_num_revoke == sdp->sd_log_commited_revoke);
749
750 sdp->sd_log_flush_head = sdp->sd_log_head;
751 sdp->sd_log_flush_wrapped = 0;
752 ai->ai_first = sdp->sd_log_flush_head;
753
754 gfs2_ordered_write(sdp);
755 lops_before_commit(sdp);
756 gfs2_ordered_wait(sdp);
757
758 if (sdp->sd_log_head != sdp->sd_log_flush_head)
759 log_flush_commit(sdp);
760 else if (sdp->sd_log_tail != current_tail(sdp) && !sdp->sd_log_idle){
761 gfs2_log_lock(sdp);
762 atomic_dec(&sdp->sd_log_blks_free); /* Adjust for unreserved buffer */
763 trace_gfs2_log_blocks(sdp, -1);
764 gfs2_log_unlock(sdp);
765 log_write_header(sdp, 0, PULL);
766 }
767 lops_after_commit(sdp, ai);
768
769 gfs2_log_lock(sdp);
770 sdp->sd_log_head = sdp->sd_log_flush_head;
771 sdp->sd_log_blks_reserved = 0;
772 sdp->sd_log_commited_buf = 0;
773 sdp->sd_log_commited_databuf = 0;
774 sdp->sd_log_commited_revoke = 0;
775
776 spin_lock(&sdp->sd_ail_lock);
777 if (!list_empty(&ai->ai_ail1_list)) {
778 list_add(&ai->ai_list, &sdp->sd_ail1_list);
779 ai = NULL;
780 }
781 spin_unlock(&sdp->sd_ail_lock);
782 gfs2_log_unlock(sdp);
783 trace_gfs2_log_flush(sdp, 0);
784 up_write(&sdp->sd_log_flush_lock);
785
786 kfree(ai);
787}
788
789static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
790{
791 unsigned int reserved;
792 unsigned int unused;
793
794 gfs2_log_lock(sdp);
795
796 sdp->sd_log_commited_buf += tr->tr_num_buf_new - tr->tr_num_buf_rm;
797 sdp->sd_log_commited_databuf += tr->tr_num_databuf_new -
798 tr->tr_num_databuf_rm;
799 gfs2_assert_withdraw(sdp, (((int)sdp->sd_log_commited_buf) >= 0) ||
800 (((int)sdp->sd_log_commited_databuf) >= 0));
801 sdp->sd_log_commited_revoke += tr->tr_num_revoke - tr->tr_num_revoke_rm;
802 reserved = calc_reserved(sdp);
803 gfs2_assert_withdraw(sdp, sdp->sd_log_blks_reserved + tr->tr_reserved >= reserved);
804 unused = sdp->sd_log_blks_reserved - reserved + tr->tr_reserved;
805 atomic_add(unused, &sdp->sd_log_blks_free);
806 trace_gfs2_log_blocks(sdp, unused);
807 gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <=
808 sdp->sd_jdesc->jd_blocks);
809 sdp->sd_log_blks_reserved = reserved;
810
811 gfs2_log_unlock(sdp);
812}
813
814static void buf_lo_incore_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
815{
816 struct list_head *head = &tr->tr_list_buf;
817 struct gfs2_bufdata *bd;
818
819 gfs2_log_lock(sdp);
820 while (!list_empty(head)) {
821 bd = list_entry(head->next, struct gfs2_bufdata, bd_list_tr);
822 list_del_init(&bd->bd_list_tr);
823 tr->tr_num_buf--;
824 }
825 gfs2_log_unlock(sdp);
826 gfs2_assert_warn(sdp, !tr->tr_num_buf);
827}
828
829/**
830 * gfs2_log_commit - Commit a transaction to the log
831 * @sdp: the filesystem
832 * @tr: the transaction
833 *
834 * We wake up gfs2_logd if the number of pinned blocks exceed thresh1
835 * or the total number of used blocks (pinned blocks plus AIL blocks)
836 * is greater than thresh2.
837 *
838 * At mount time thresh1 is 1/3rd of journal size, thresh2 is 2/3rd of
839 * journal size.
840 *
841 * Returns: errno
842 */
843
844void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
845{
846 log_refund(sdp, tr);
847 buf_lo_incore_commit(sdp, tr);
848
849 up_read(&sdp->sd_log_flush_lock);
850
851 if (atomic_read(&sdp->sd_log_pinned) > atomic_read(&sdp->sd_log_thresh1) ||
852 ((sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free)) >
853 atomic_read(&sdp->sd_log_thresh2)))
854 wake_up(&sdp->sd_logd_waitq);
855}
856
857/**
858 * gfs2_log_shutdown - write a shutdown header into a journal
859 * @sdp: the filesystem
860 *
861 */
862
863void gfs2_log_shutdown(struct gfs2_sbd *sdp)
864{
865 down_write(&sdp->sd_log_flush_lock);
866
867 gfs2_assert_withdraw(sdp, !sdp->sd_log_blks_reserved);
868 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_buf);
869 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke);
870 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_rg);
871 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_databuf);
872 gfs2_assert_withdraw(sdp, list_empty(&sdp->sd_ail1_list));
873
874 sdp->sd_log_flush_head = sdp->sd_log_head;
875 sdp->sd_log_flush_wrapped = 0;
876
877 log_write_header(sdp, GFS2_LOG_HEAD_UNMOUNT,
878 (sdp->sd_log_tail == current_tail(sdp)) ? 0 : PULL);
879
880 gfs2_assert_warn(sdp, atomic_read(&sdp->sd_log_blks_free) == sdp->sd_jdesc->jd_blocks);
881 gfs2_assert_warn(sdp, sdp->sd_log_head == sdp->sd_log_tail);
882 gfs2_assert_warn(sdp, list_empty(&sdp->sd_ail2_list));
883
884 sdp->sd_log_head = sdp->sd_log_flush_head;
885 sdp->sd_log_tail = sdp->sd_log_head;
886
887 up_write(&sdp->sd_log_flush_lock);
888}
889
890
891/**
892 * gfs2_meta_syncfs - sync all the buffers in a filesystem
893 * @sdp: the filesystem
894 *
895 */
896
897void gfs2_meta_syncfs(struct gfs2_sbd *sdp)
898{
899 gfs2_log_flush(sdp, NULL);
900 for (;;) {
901 gfs2_ail1_start(sdp);
902 gfs2_ail1_wait(sdp);
903 if (gfs2_ail1_empty(sdp))
904 break;
905 }
906 gfs2_log_flush(sdp, NULL);
907}
908
909static inline int gfs2_jrnl_flush_reqd(struct gfs2_sbd *sdp)
910{
911 return (atomic_read(&sdp->sd_log_pinned) >= atomic_read(&sdp->sd_log_thresh1));
912}
913
914static inline int gfs2_ail_flush_reqd(struct gfs2_sbd *sdp)
915{
916 unsigned int used_blocks = sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free);
917 return used_blocks >= atomic_read(&sdp->sd_log_thresh2);
918}
919
920/**
921 * gfs2_logd - Update log tail as Active Items get flushed to in-place blocks
922 * @sdp: Pointer to GFS2 superblock
923 *
924 * Also, periodically check to make sure that we're using the most recent
925 * journal index.
926 */
927
928int gfs2_logd(void *data)
929{
930 struct gfs2_sbd *sdp = data;
931 unsigned long t = 1;
932 DEFINE_WAIT(wait);
933 unsigned preflush;
934
935 while (!kthread_should_stop()) {
936
937 preflush = atomic_read(&sdp->sd_log_pinned);
938 if (gfs2_jrnl_flush_reqd(sdp) || t == 0) {
939 gfs2_ail1_empty(sdp);
940 gfs2_log_flush(sdp, NULL);
941 }
942
943 if (gfs2_ail_flush_reqd(sdp)) {
944 gfs2_ail1_start(sdp);
945 gfs2_ail1_wait(sdp);
946 gfs2_ail1_empty(sdp);
947 gfs2_log_flush(sdp, NULL);
948 }
949
950 if (!gfs2_ail_flush_reqd(sdp))
951 wake_up(&sdp->sd_log_waitq);
952
953 t = gfs2_tune_get(sdp, gt_logd_secs) * HZ;
954 if (freezing(current))
955 refrigerator();
956
957 do {
958 prepare_to_wait(&sdp->sd_logd_waitq, &wait,
959 TASK_INTERRUPTIBLE);
960 if (!gfs2_ail_flush_reqd(sdp) &&
961 !gfs2_jrnl_flush_reqd(sdp) &&
962 !kthread_should_stop())
963 t = schedule_timeout(t);
964 } while(t && !gfs2_ail_flush_reqd(sdp) &&
965 !gfs2_jrnl_flush_reqd(sdp) &&
966 !kthread_should_stop());
967 finish_wait(&sdp->sd_logd_waitq, &wait);
968 }
969
970 return 0;
971}
972
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/blkdev.h>
22#include <linux/writeback.h>
23#include <linux/list_sort.h>
24
25#include "gfs2.h"
26#include "incore.h"
27#include "bmap.h"
28#include "glock.h"
29#include "log.h"
30#include "lops.h"
31#include "meta_io.h"
32#include "util.h"
33#include "dir.h"
34#include "trace_gfs2.h"
35
36/**
37 * gfs2_struct2blk - compute stuff
38 * @sdp: the filesystem
39 * @nstruct: the number of structures
40 * @ssize: the size of the structures
41 *
42 * Compute the number of log descriptor blocks needed to hold a certain number
43 * of structures of a certain size.
44 *
45 * Returns: the number of blocks needed (minimum is always 1)
46 */
47
48unsigned int gfs2_struct2blk(struct gfs2_sbd *sdp, unsigned int nstruct,
49 unsigned int ssize)
50{
51 unsigned int blks;
52 unsigned int first, second;
53
54 blks = 1;
55 first = (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_log_descriptor)) / ssize;
56
57 if (nstruct > first) {
58 second = (sdp->sd_sb.sb_bsize -
59 sizeof(struct gfs2_meta_header)) / ssize;
60 blks += DIV_ROUND_UP(nstruct - first, second);
61 }
62
63 return blks;
64}
65
66/**
67 * gfs2_remove_from_ail - Remove an entry from the ail lists, updating counters
68 * @mapping: The associated mapping (maybe NULL)
69 * @bd: The gfs2_bufdata to remove
70 *
71 * The ail lock _must_ be held when calling this function
72 *
73 */
74
75void gfs2_remove_from_ail(struct gfs2_bufdata *bd)
76{
77 bd->bd_tr = NULL;
78 list_del_init(&bd->bd_ail_st_list);
79 list_del_init(&bd->bd_ail_gl_list);
80 atomic_dec(&bd->bd_gl->gl_ail_count);
81 brelse(bd->bd_bh);
82}
83
84/**
85 * gfs2_ail1_start_one - Start I/O on a part of the AIL
86 * @sdp: the filesystem
87 * @wbc: The writeback control structure
88 * @ai: The ail structure
89 *
90 */
91
92static int gfs2_ail1_start_one(struct gfs2_sbd *sdp,
93 struct writeback_control *wbc,
94 struct gfs2_trans *tr)
95__releases(&sdp->sd_ail_lock)
96__acquires(&sdp->sd_ail_lock)
97{
98 struct gfs2_glock *gl = NULL;
99 struct address_space *mapping;
100 struct gfs2_bufdata *bd, *s;
101 struct buffer_head *bh;
102
103 list_for_each_entry_safe_reverse(bd, s, &tr->tr_ail1_list, bd_ail_st_list) {
104 bh = bd->bd_bh;
105
106 gfs2_assert(sdp, bd->bd_tr == tr);
107
108 if (!buffer_busy(bh)) {
109 if (!buffer_uptodate(bh))
110 gfs2_io_error_bh(sdp, bh);
111 list_move(&bd->bd_ail_st_list, &tr->tr_ail2_list);
112 continue;
113 }
114
115 if (!buffer_dirty(bh))
116 continue;
117 if (gl == bd->bd_gl)
118 continue;
119 gl = bd->bd_gl;
120 list_move(&bd->bd_ail_st_list, &tr->tr_ail1_list);
121 mapping = bh->b_page->mapping;
122 if (!mapping)
123 continue;
124 spin_unlock(&sdp->sd_ail_lock);
125 generic_writepages(mapping, wbc);
126 spin_lock(&sdp->sd_ail_lock);
127 if (wbc->nr_to_write <= 0)
128 break;
129 return 1;
130 }
131
132 return 0;
133}
134
135
136/**
137 * gfs2_ail1_flush - start writeback of some ail1 entries
138 * @sdp: The super block
139 * @wbc: The writeback control structure
140 *
141 * Writes back some ail1 entries, according to the limits in the
142 * writeback control structure
143 */
144
145void gfs2_ail1_flush(struct gfs2_sbd *sdp, struct writeback_control *wbc)
146{
147 struct list_head *head = &sdp->sd_ail1_list;
148 struct gfs2_trans *tr;
149 struct blk_plug plug;
150
151 trace_gfs2_ail_flush(sdp, wbc, 1);
152 blk_start_plug(&plug);
153 spin_lock(&sdp->sd_ail_lock);
154restart:
155 list_for_each_entry_reverse(tr, head, tr_list) {
156 if (wbc->nr_to_write <= 0)
157 break;
158 if (gfs2_ail1_start_one(sdp, wbc, tr))
159 goto restart;
160 }
161 spin_unlock(&sdp->sd_ail_lock);
162 blk_finish_plug(&plug);
163 trace_gfs2_ail_flush(sdp, wbc, 0);
164}
165
166/**
167 * gfs2_ail1_start - start writeback of all ail1 entries
168 * @sdp: The superblock
169 */
170
171static void gfs2_ail1_start(struct gfs2_sbd *sdp)
172{
173 struct writeback_control wbc = {
174 .sync_mode = WB_SYNC_NONE,
175 .nr_to_write = LONG_MAX,
176 .range_start = 0,
177 .range_end = LLONG_MAX,
178 };
179
180 return gfs2_ail1_flush(sdp, &wbc);
181}
182
183/**
184 * gfs2_ail1_empty_one - Check whether or not a trans in the AIL has been synced
185 * @sdp: the filesystem
186 * @ai: the AIL entry
187 *
188 */
189
190static void gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
191{
192 struct gfs2_bufdata *bd, *s;
193 struct buffer_head *bh;
194
195 list_for_each_entry_safe_reverse(bd, s, &tr->tr_ail1_list,
196 bd_ail_st_list) {
197 bh = bd->bd_bh;
198 gfs2_assert(sdp, bd->bd_tr == tr);
199 if (buffer_busy(bh))
200 continue;
201 if (!buffer_uptodate(bh))
202 gfs2_io_error_bh(sdp, bh);
203 list_move(&bd->bd_ail_st_list, &tr->tr_ail2_list);
204 }
205
206}
207
208/**
209 * gfs2_ail1_empty - Try to empty the ail1 lists
210 * @sdp: The superblock
211 *
212 * Tries to empty the ail1 lists, starting with the oldest first
213 */
214
215static int gfs2_ail1_empty(struct gfs2_sbd *sdp)
216{
217 struct gfs2_trans *tr, *s;
218 int oldest_tr = 1;
219 int ret;
220
221 spin_lock(&sdp->sd_ail_lock);
222 list_for_each_entry_safe_reverse(tr, s, &sdp->sd_ail1_list, tr_list) {
223 gfs2_ail1_empty_one(sdp, tr);
224 if (list_empty(&tr->tr_ail1_list) && oldest_tr)
225 list_move(&tr->tr_list, &sdp->sd_ail2_list);
226 else
227 oldest_tr = 0;
228 }
229 ret = list_empty(&sdp->sd_ail1_list);
230 spin_unlock(&sdp->sd_ail_lock);
231
232 return ret;
233}
234
235static void gfs2_ail1_wait(struct gfs2_sbd *sdp)
236{
237 struct gfs2_trans *tr;
238 struct gfs2_bufdata *bd;
239 struct buffer_head *bh;
240
241 spin_lock(&sdp->sd_ail_lock);
242 list_for_each_entry_reverse(tr, &sdp->sd_ail1_list, tr_list) {
243 list_for_each_entry(bd, &tr->tr_ail1_list, bd_ail_st_list) {
244 bh = bd->bd_bh;
245 if (!buffer_locked(bh))
246 continue;
247 get_bh(bh);
248 spin_unlock(&sdp->sd_ail_lock);
249 wait_on_buffer(bh);
250 brelse(bh);
251 return;
252 }
253 }
254 spin_unlock(&sdp->sd_ail_lock);
255}
256
257/**
258 * gfs2_ail2_empty_one - Check whether or not a trans in the AIL has been synced
259 * @sdp: the filesystem
260 * @ai: the AIL entry
261 *
262 */
263
264static void gfs2_ail2_empty_one(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
265{
266 struct list_head *head = &tr->tr_ail2_list;
267 struct gfs2_bufdata *bd;
268
269 while (!list_empty(head)) {
270 bd = list_entry(head->prev, struct gfs2_bufdata,
271 bd_ail_st_list);
272 gfs2_assert(sdp, bd->bd_tr == tr);
273 gfs2_remove_from_ail(bd);
274 }
275}
276
277static void ail2_empty(struct gfs2_sbd *sdp, unsigned int new_tail)
278{
279 struct gfs2_trans *tr, *safe;
280 unsigned int old_tail = sdp->sd_log_tail;
281 int wrap = (new_tail < old_tail);
282 int a, b, rm;
283
284 spin_lock(&sdp->sd_ail_lock);
285
286 list_for_each_entry_safe(tr, safe, &sdp->sd_ail2_list, tr_list) {
287 a = (old_tail <= tr->tr_first);
288 b = (tr->tr_first < new_tail);
289 rm = (wrap) ? (a || b) : (a && b);
290 if (!rm)
291 continue;
292
293 gfs2_ail2_empty_one(sdp, tr);
294 list_del(&tr->tr_list);
295 gfs2_assert_warn(sdp, list_empty(&tr->tr_ail1_list));
296 gfs2_assert_warn(sdp, list_empty(&tr->tr_ail2_list));
297 kfree(tr);
298 }
299
300 spin_unlock(&sdp->sd_ail_lock);
301}
302
303/**
304 * gfs2_log_release - Release a given number of log blocks
305 * @sdp: The GFS2 superblock
306 * @blks: The number of blocks
307 *
308 */
309
310void gfs2_log_release(struct gfs2_sbd *sdp, unsigned int blks)
311{
312
313 atomic_add(blks, &sdp->sd_log_blks_free);
314 trace_gfs2_log_blocks(sdp, blks);
315 gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <=
316 sdp->sd_jdesc->jd_blocks);
317 up_read(&sdp->sd_log_flush_lock);
318}
319
320/**
321 * gfs2_log_reserve - Make a log reservation
322 * @sdp: The GFS2 superblock
323 * @blks: The number of blocks to reserve
324 *
325 * Note that we never give out the last few blocks of the journal. Thats
326 * due to the fact that there is a small number of header blocks
327 * associated with each log flush. The exact number can't be known until
328 * flush time, so we ensure that we have just enough free blocks at all
329 * times to avoid running out during a log flush.
330 *
331 * We no longer flush the log here, instead we wake up logd to do that
332 * for us. To avoid the thundering herd and to ensure that we deal fairly
333 * with queued waiters, we use an exclusive wait. This means that when we
334 * get woken with enough journal space to get our reservation, we need to
335 * wake the next waiter on the list.
336 *
337 * Returns: errno
338 */
339
340int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks)
341{
342 int ret = 0;
343 unsigned reserved_blks = 7 * (4096 / sdp->sd_vfs->s_blocksize);
344 unsigned wanted = blks + reserved_blks;
345 DEFINE_WAIT(wait);
346 int did_wait = 0;
347 unsigned int free_blocks;
348
349 if (gfs2_assert_warn(sdp, blks) ||
350 gfs2_assert_warn(sdp, blks <= sdp->sd_jdesc->jd_blocks))
351 return -EINVAL;
352retry:
353 free_blocks = atomic_read(&sdp->sd_log_blks_free);
354 if (unlikely(free_blocks <= wanted)) {
355 do {
356 prepare_to_wait_exclusive(&sdp->sd_log_waitq, &wait,
357 TASK_UNINTERRUPTIBLE);
358 wake_up(&sdp->sd_logd_waitq);
359 did_wait = 1;
360 if (atomic_read(&sdp->sd_log_blks_free) <= wanted)
361 io_schedule();
362 free_blocks = atomic_read(&sdp->sd_log_blks_free);
363 } while(free_blocks <= wanted);
364 finish_wait(&sdp->sd_log_waitq, &wait);
365 }
366 atomic_inc(&sdp->sd_reserving_log);
367 if (atomic_cmpxchg(&sdp->sd_log_blks_free, free_blocks,
368 free_blocks - blks) != free_blocks) {
369 if (atomic_dec_and_test(&sdp->sd_reserving_log))
370 wake_up(&sdp->sd_reserving_log_wait);
371 goto retry;
372 }
373 trace_gfs2_log_blocks(sdp, -blks);
374
375 /*
376 * If we waited, then so might others, wake them up _after_ we get
377 * our share of the log.
378 */
379 if (unlikely(did_wait))
380 wake_up(&sdp->sd_log_waitq);
381
382 down_read(&sdp->sd_log_flush_lock);
383 if (unlikely(!test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags))) {
384 gfs2_log_release(sdp, blks);
385 ret = -EROFS;
386 }
387 if (atomic_dec_and_test(&sdp->sd_reserving_log))
388 wake_up(&sdp->sd_reserving_log_wait);
389 return ret;
390}
391
392/**
393 * log_distance - Compute distance between two journal blocks
394 * @sdp: The GFS2 superblock
395 * @newer: The most recent journal block of the pair
396 * @older: The older journal block of the pair
397 *
398 * Compute the distance (in the journal direction) between two
399 * blocks in the journal
400 *
401 * Returns: the distance in blocks
402 */
403
404static inline unsigned int log_distance(struct gfs2_sbd *sdp, unsigned int newer,
405 unsigned int older)
406{
407 int dist;
408
409 dist = newer - older;
410 if (dist < 0)
411 dist += sdp->sd_jdesc->jd_blocks;
412
413 return dist;
414}
415
416/**
417 * calc_reserved - Calculate the number of blocks to reserve when
418 * refunding a transaction's unused buffers.
419 * @sdp: The GFS2 superblock
420 *
421 * This is complex. We need to reserve room for all our currently used
422 * metadata buffers (e.g. normal file I/O rewriting file time stamps) and
423 * all our journaled data buffers for journaled files (e.g. files in the
424 * meta_fs like rindex, or files for which chattr +j was done.)
425 * If we don't reserve enough space, gfs2_log_refund and gfs2_log_flush
426 * will count it as free space (sd_log_blks_free) and corruption will follow.
427 *
428 * We can have metadata bufs and jdata bufs in the same journal. So each
429 * type gets its own log header, for which we need to reserve a block.
430 * In fact, each type has the potential for needing more than one header
431 * in cases where we have more buffers than will fit on a journal page.
432 * Metadata journal entries take up half the space of journaled buffer entries.
433 * Thus, metadata entries have buf_limit (502) and journaled buffers have
434 * databuf_limit (251) before they cause a wrap around.
435 *
436 * Also, we need to reserve blocks for revoke journal entries and one for an
437 * overall header for the lot.
438 *
439 * Returns: the number of blocks reserved
440 */
441static unsigned int calc_reserved(struct gfs2_sbd *sdp)
442{
443 unsigned int reserved = 0;
444 unsigned int mbuf;
445 unsigned int dbuf;
446 struct gfs2_trans *tr = sdp->sd_log_tr;
447
448 if (tr) {
449 mbuf = tr->tr_num_buf_new - tr->tr_num_buf_rm;
450 dbuf = tr->tr_num_databuf_new - tr->tr_num_databuf_rm;
451 reserved = mbuf + dbuf;
452 /* Account for header blocks */
453 reserved += DIV_ROUND_UP(mbuf, buf_limit(sdp));
454 reserved += DIV_ROUND_UP(dbuf, databuf_limit(sdp));
455 }
456
457 if (sdp->sd_log_commited_revoke > 0)
458 reserved += gfs2_struct2blk(sdp, sdp->sd_log_commited_revoke,
459 sizeof(u64));
460 /* One for the overall header */
461 if (reserved)
462 reserved++;
463 return reserved;
464}
465
466static unsigned int current_tail(struct gfs2_sbd *sdp)
467{
468 struct gfs2_trans *tr;
469 unsigned int tail;
470
471 spin_lock(&sdp->sd_ail_lock);
472
473 if (list_empty(&sdp->sd_ail1_list)) {
474 tail = sdp->sd_log_head;
475 } else {
476 tr = list_entry(sdp->sd_ail1_list.prev, struct gfs2_trans,
477 tr_list);
478 tail = tr->tr_first;
479 }
480
481 spin_unlock(&sdp->sd_ail_lock);
482
483 return tail;
484}
485
486static void log_pull_tail(struct gfs2_sbd *sdp, unsigned int new_tail)
487{
488 unsigned int dist = log_distance(sdp, new_tail, sdp->sd_log_tail);
489
490 ail2_empty(sdp, new_tail);
491
492 atomic_add(dist, &sdp->sd_log_blks_free);
493 trace_gfs2_log_blocks(sdp, dist);
494 gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <=
495 sdp->sd_jdesc->jd_blocks);
496
497 sdp->sd_log_tail = new_tail;
498}
499
500
501static void log_flush_wait(struct gfs2_sbd *sdp)
502{
503 DEFINE_WAIT(wait);
504
505 if (atomic_read(&sdp->sd_log_in_flight)) {
506 do {
507 prepare_to_wait(&sdp->sd_log_flush_wait, &wait,
508 TASK_UNINTERRUPTIBLE);
509 if (atomic_read(&sdp->sd_log_in_flight))
510 io_schedule();
511 } while(atomic_read(&sdp->sd_log_in_flight));
512 finish_wait(&sdp->sd_log_flush_wait, &wait);
513 }
514}
515
516static int ip_cmp(void *priv, struct list_head *a, struct list_head *b)
517{
518 struct gfs2_inode *ipa, *ipb;
519
520 ipa = list_entry(a, struct gfs2_inode, i_ordered);
521 ipb = list_entry(b, struct gfs2_inode, i_ordered);
522
523 if (ipa->i_no_addr < ipb->i_no_addr)
524 return -1;
525 if (ipa->i_no_addr > ipb->i_no_addr)
526 return 1;
527 return 0;
528}
529
530static void gfs2_ordered_write(struct gfs2_sbd *sdp)
531{
532 struct gfs2_inode *ip;
533 LIST_HEAD(written);
534
535 spin_lock(&sdp->sd_ordered_lock);
536 list_sort(NULL, &sdp->sd_log_le_ordered, &ip_cmp);
537 while (!list_empty(&sdp->sd_log_le_ordered)) {
538 ip = list_entry(sdp->sd_log_le_ordered.next, struct gfs2_inode, i_ordered);
539 list_move(&ip->i_ordered, &written);
540 if (ip->i_inode.i_mapping->nrpages == 0)
541 continue;
542 spin_unlock(&sdp->sd_ordered_lock);
543 filemap_fdatawrite(ip->i_inode.i_mapping);
544 spin_lock(&sdp->sd_ordered_lock);
545 }
546 list_splice(&written, &sdp->sd_log_le_ordered);
547 spin_unlock(&sdp->sd_ordered_lock);
548}
549
550static void gfs2_ordered_wait(struct gfs2_sbd *sdp)
551{
552 struct gfs2_inode *ip;
553
554 spin_lock(&sdp->sd_ordered_lock);
555 while (!list_empty(&sdp->sd_log_le_ordered)) {
556 ip = list_entry(sdp->sd_log_le_ordered.next, struct gfs2_inode, i_ordered);
557 list_del(&ip->i_ordered);
558 WARN_ON(!test_and_clear_bit(GIF_ORDERED, &ip->i_flags));
559 if (ip->i_inode.i_mapping->nrpages == 0)
560 continue;
561 spin_unlock(&sdp->sd_ordered_lock);
562 filemap_fdatawait(ip->i_inode.i_mapping);
563 spin_lock(&sdp->sd_ordered_lock);
564 }
565 spin_unlock(&sdp->sd_ordered_lock);
566}
567
568void gfs2_ordered_del_inode(struct gfs2_inode *ip)
569{
570 struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
571
572 spin_lock(&sdp->sd_ordered_lock);
573 if (test_and_clear_bit(GIF_ORDERED, &ip->i_flags))
574 list_del(&ip->i_ordered);
575 spin_unlock(&sdp->sd_ordered_lock);
576}
577
578void gfs2_add_revoke(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd)
579{
580 struct buffer_head *bh = bd->bd_bh;
581 struct gfs2_glock *gl = bd->bd_gl;
582
583 bh->b_private = NULL;
584 bd->bd_blkno = bh->b_blocknr;
585 gfs2_remove_from_ail(bd); /* drops ref on bh */
586 bd->bd_bh = NULL;
587 bd->bd_ops = &gfs2_revoke_lops;
588 sdp->sd_log_num_revoke++;
589 atomic_inc(&gl->gl_revokes);
590 set_bit(GLF_LFLUSH, &gl->gl_flags);
591 list_add(&bd->bd_list, &sdp->sd_log_le_revoke);
592}
593
594void gfs2_write_revokes(struct gfs2_sbd *sdp)
595{
596 struct gfs2_trans *tr;
597 struct gfs2_bufdata *bd, *tmp;
598 int have_revokes = 0;
599 int max_revokes = (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_log_descriptor)) / sizeof(u64);
600
601 gfs2_ail1_empty(sdp);
602 spin_lock(&sdp->sd_ail_lock);
603 list_for_each_entry(tr, &sdp->sd_ail1_list, tr_list) {
604 list_for_each_entry(bd, &tr->tr_ail2_list, bd_ail_st_list) {
605 if (list_empty(&bd->bd_list)) {
606 have_revokes = 1;
607 goto done;
608 }
609 }
610 }
611done:
612 spin_unlock(&sdp->sd_ail_lock);
613 if (have_revokes == 0)
614 return;
615 while (sdp->sd_log_num_revoke > max_revokes)
616 max_revokes += (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_meta_header)) / sizeof(u64);
617 max_revokes -= sdp->sd_log_num_revoke;
618 if (!sdp->sd_log_num_revoke) {
619 atomic_dec(&sdp->sd_log_blks_free);
620 /* If no blocks have been reserved, we need to also
621 * reserve a block for the header */
622 if (!sdp->sd_log_blks_reserved)
623 atomic_dec(&sdp->sd_log_blks_free);
624 }
625 gfs2_log_lock(sdp);
626 spin_lock(&sdp->sd_ail_lock);
627 list_for_each_entry(tr, &sdp->sd_ail1_list, tr_list) {
628 list_for_each_entry_safe(bd, tmp, &tr->tr_ail2_list, bd_ail_st_list) {
629 if (max_revokes == 0)
630 goto out_of_blocks;
631 if (!list_empty(&bd->bd_list))
632 continue;
633 gfs2_add_revoke(sdp, bd);
634 max_revokes--;
635 }
636 }
637out_of_blocks:
638 spin_unlock(&sdp->sd_ail_lock);
639 gfs2_log_unlock(sdp);
640
641 if (!sdp->sd_log_num_revoke) {
642 atomic_inc(&sdp->sd_log_blks_free);
643 if (!sdp->sd_log_blks_reserved)
644 atomic_inc(&sdp->sd_log_blks_free);
645 }
646}
647
648/**
649 * log_write_header - Get and initialize a journal header buffer
650 * @sdp: The GFS2 superblock
651 *
652 * Returns: the initialized log buffer descriptor
653 */
654
655static void log_write_header(struct gfs2_sbd *sdp, u32 flags)
656{
657 struct gfs2_log_header *lh;
658 unsigned int tail;
659 u32 hash;
660 int rw = WRITE_FLUSH_FUA | REQ_META;
661 struct page *page = mempool_alloc(gfs2_page_pool, GFP_NOIO);
662 enum gfs2_freeze_state state = atomic_read(&sdp->sd_freeze_state);
663 lh = page_address(page);
664 clear_page(lh);
665
666 gfs2_assert_withdraw(sdp, (state != SFS_FROZEN));
667
668 tail = current_tail(sdp);
669
670 lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
671 lh->lh_header.mh_type = cpu_to_be32(GFS2_METATYPE_LH);
672 lh->lh_header.__pad0 = cpu_to_be64(0);
673 lh->lh_header.mh_format = cpu_to_be32(GFS2_FORMAT_LH);
674 lh->lh_header.mh_jid = cpu_to_be32(sdp->sd_jdesc->jd_jid);
675 lh->lh_sequence = cpu_to_be64(sdp->sd_log_sequence++);
676 lh->lh_flags = cpu_to_be32(flags);
677 lh->lh_tail = cpu_to_be32(tail);
678 lh->lh_blkno = cpu_to_be32(sdp->sd_log_flush_head);
679 hash = gfs2_disk_hash(page_address(page), sizeof(struct gfs2_log_header));
680 lh->lh_hash = cpu_to_be32(hash);
681
682 if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags)) {
683 gfs2_ordered_wait(sdp);
684 log_flush_wait(sdp);
685 rw = WRITE_SYNC | REQ_META | REQ_PRIO;
686 }
687
688 sdp->sd_log_idle = (tail == sdp->sd_log_flush_head);
689 gfs2_log_write_page(sdp, page);
690 gfs2_log_flush_bio(sdp, rw);
691 log_flush_wait(sdp);
692
693 if (sdp->sd_log_tail != tail)
694 log_pull_tail(sdp, tail);
695}
696
697/**
698 * gfs2_log_flush - flush incore transaction(s)
699 * @sdp: the filesystem
700 * @gl: The glock structure to flush. If NULL, flush the whole incore log
701 *
702 */
703
704void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl,
705 enum gfs2_flush_type type)
706{
707 struct gfs2_trans *tr;
708 enum gfs2_freeze_state state = atomic_read(&sdp->sd_freeze_state);
709
710 down_write(&sdp->sd_log_flush_lock);
711
712 /* Log might have been flushed while we waited for the flush lock */
713 if (gl && !test_bit(GLF_LFLUSH, &gl->gl_flags)) {
714 up_write(&sdp->sd_log_flush_lock);
715 return;
716 }
717 trace_gfs2_log_flush(sdp, 1);
718
719 if (type == SHUTDOWN_FLUSH)
720 clear_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
721
722 sdp->sd_log_flush_head = sdp->sd_log_head;
723 sdp->sd_log_flush_wrapped = 0;
724 tr = sdp->sd_log_tr;
725 if (tr) {
726 sdp->sd_log_tr = NULL;
727 INIT_LIST_HEAD(&tr->tr_ail1_list);
728 INIT_LIST_HEAD(&tr->tr_ail2_list);
729 tr->tr_first = sdp->sd_log_flush_head;
730 if (unlikely (state == SFS_FROZEN))
731 gfs2_assert_withdraw(sdp, !tr->tr_num_buf_new && !tr->tr_num_databuf_new);
732 }
733
734 if (unlikely(state == SFS_FROZEN))
735 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke);
736 gfs2_assert_withdraw(sdp,
737 sdp->sd_log_num_revoke == sdp->sd_log_commited_revoke);
738
739 gfs2_ordered_write(sdp);
740 lops_before_commit(sdp, tr);
741 gfs2_log_flush_bio(sdp, WRITE);
742
743 if (sdp->sd_log_head != sdp->sd_log_flush_head) {
744 log_flush_wait(sdp);
745 log_write_header(sdp, 0);
746 } else if (sdp->sd_log_tail != current_tail(sdp) && !sdp->sd_log_idle){
747 atomic_dec(&sdp->sd_log_blks_free); /* Adjust for unreserved buffer */
748 trace_gfs2_log_blocks(sdp, -1);
749 log_write_header(sdp, 0);
750 }
751 lops_after_commit(sdp, tr);
752
753 gfs2_log_lock(sdp);
754 sdp->sd_log_head = sdp->sd_log_flush_head;
755 sdp->sd_log_blks_reserved = 0;
756 sdp->sd_log_commited_revoke = 0;
757
758 spin_lock(&sdp->sd_ail_lock);
759 if (tr && !list_empty(&tr->tr_ail1_list)) {
760 list_add(&tr->tr_list, &sdp->sd_ail1_list);
761 tr = NULL;
762 }
763 spin_unlock(&sdp->sd_ail_lock);
764 gfs2_log_unlock(sdp);
765
766 if (type != NORMAL_FLUSH) {
767 if (!sdp->sd_log_idle) {
768 for (;;) {
769 gfs2_ail1_start(sdp);
770 gfs2_ail1_wait(sdp);
771 if (gfs2_ail1_empty(sdp))
772 break;
773 }
774 atomic_dec(&sdp->sd_log_blks_free); /* Adjust for unreserved buffer */
775 trace_gfs2_log_blocks(sdp, -1);
776 sdp->sd_log_flush_wrapped = 0;
777 log_write_header(sdp, 0);
778 sdp->sd_log_head = sdp->sd_log_flush_head;
779 }
780 if (type == SHUTDOWN_FLUSH || type == FREEZE_FLUSH)
781 gfs2_log_shutdown(sdp);
782 if (type == FREEZE_FLUSH)
783 atomic_set(&sdp->sd_freeze_state, SFS_FROZEN);
784 }
785
786 trace_gfs2_log_flush(sdp, 0);
787 up_write(&sdp->sd_log_flush_lock);
788
789 kfree(tr);
790}
791
792/**
793 * gfs2_merge_trans - Merge a new transaction into a cached transaction
794 * @old: Original transaction to be expanded
795 * @new: New transaction to be merged
796 */
797
798static void gfs2_merge_trans(struct gfs2_trans *old, struct gfs2_trans *new)
799{
800 WARN_ON_ONCE(old->tr_attached != 1);
801
802 old->tr_num_buf_new += new->tr_num_buf_new;
803 old->tr_num_databuf_new += new->tr_num_databuf_new;
804 old->tr_num_buf_rm += new->tr_num_buf_rm;
805 old->tr_num_databuf_rm += new->tr_num_databuf_rm;
806 old->tr_num_revoke += new->tr_num_revoke;
807 old->tr_num_revoke_rm += new->tr_num_revoke_rm;
808
809 list_splice_tail_init(&new->tr_databuf, &old->tr_databuf);
810 list_splice_tail_init(&new->tr_buf, &old->tr_buf);
811}
812
813static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
814{
815 unsigned int reserved;
816 unsigned int unused;
817 unsigned int maxres;
818
819 gfs2_log_lock(sdp);
820
821 if (sdp->sd_log_tr) {
822 gfs2_merge_trans(sdp->sd_log_tr, tr);
823 } else if (tr->tr_num_buf_new || tr->tr_num_databuf_new) {
824 gfs2_assert_withdraw(sdp, tr->tr_alloced);
825 sdp->sd_log_tr = tr;
826 tr->tr_attached = 1;
827 }
828
829 sdp->sd_log_commited_revoke += tr->tr_num_revoke - tr->tr_num_revoke_rm;
830 reserved = calc_reserved(sdp);
831 maxres = sdp->sd_log_blks_reserved + tr->tr_reserved;
832 gfs2_assert_withdraw(sdp, maxres >= reserved);
833 unused = maxres - reserved;
834 atomic_add(unused, &sdp->sd_log_blks_free);
835 trace_gfs2_log_blocks(sdp, unused);
836 gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <=
837 sdp->sd_jdesc->jd_blocks);
838 sdp->sd_log_blks_reserved = reserved;
839
840 gfs2_log_unlock(sdp);
841}
842
843/**
844 * gfs2_log_commit - Commit a transaction to the log
845 * @sdp: the filesystem
846 * @tr: the transaction
847 *
848 * We wake up gfs2_logd if the number of pinned blocks exceed thresh1
849 * or the total number of used blocks (pinned blocks plus AIL blocks)
850 * is greater than thresh2.
851 *
852 * At mount time thresh1 is 1/3rd of journal size, thresh2 is 2/3rd of
853 * journal size.
854 *
855 * Returns: errno
856 */
857
858void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
859{
860 log_refund(sdp, tr);
861
862 if (atomic_read(&sdp->sd_log_pinned) > atomic_read(&sdp->sd_log_thresh1) ||
863 ((sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free)) >
864 atomic_read(&sdp->sd_log_thresh2)))
865 wake_up(&sdp->sd_logd_waitq);
866}
867
868/**
869 * gfs2_log_shutdown - write a shutdown header into a journal
870 * @sdp: the filesystem
871 *
872 */
873
874void gfs2_log_shutdown(struct gfs2_sbd *sdp)
875{
876 gfs2_assert_withdraw(sdp, !sdp->sd_log_blks_reserved);
877 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke);
878 gfs2_assert_withdraw(sdp, list_empty(&sdp->sd_ail1_list));
879
880 sdp->sd_log_flush_head = sdp->sd_log_head;
881 sdp->sd_log_flush_wrapped = 0;
882
883 log_write_header(sdp, GFS2_LOG_HEAD_UNMOUNT);
884
885 gfs2_assert_warn(sdp, sdp->sd_log_head == sdp->sd_log_tail);
886 gfs2_assert_warn(sdp, list_empty(&sdp->sd_ail2_list));
887
888 sdp->sd_log_head = sdp->sd_log_flush_head;
889 sdp->sd_log_tail = sdp->sd_log_head;
890}
891
892static inline int gfs2_jrnl_flush_reqd(struct gfs2_sbd *sdp)
893{
894 return (atomic_read(&sdp->sd_log_pinned) >= atomic_read(&sdp->sd_log_thresh1));
895}
896
897static inline int gfs2_ail_flush_reqd(struct gfs2_sbd *sdp)
898{
899 unsigned int used_blocks = sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free);
900 return used_blocks >= atomic_read(&sdp->sd_log_thresh2);
901}
902
903/**
904 * gfs2_logd - Update log tail as Active Items get flushed to in-place blocks
905 * @sdp: Pointer to GFS2 superblock
906 *
907 * Also, periodically check to make sure that we're using the most recent
908 * journal index.
909 */
910
911int gfs2_logd(void *data)
912{
913 struct gfs2_sbd *sdp = data;
914 unsigned long t = 1;
915 DEFINE_WAIT(wait);
916
917 while (!kthread_should_stop()) {
918
919 if (gfs2_jrnl_flush_reqd(sdp) || t == 0) {
920 gfs2_ail1_empty(sdp);
921 gfs2_log_flush(sdp, NULL, NORMAL_FLUSH);
922 }
923
924 if (gfs2_ail_flush_reqd(sdp)) {
925 gfs2_ail1_start(sdp);
926 gfs2_ail1_wait(sdp);
927 gfs2_ail1_empty(sdp);
928 gfs2_log_flush(sdp, NULL, NORMAL_FLUSH);
929 }
930
931 if (!gfs2_ail_flush_reqd(sdp))
932 wake_up(&sdp->sd_log_waitq);
933
934 t = gfs2_tune_get(sdp, gt_logd_secs) * HZ;
935
936 try_to_freeze();
937
938 do {
939 prepare_to_wait(&sdp->sd_logd_waitq, &wait,
940 TASK_INTERRUPTIBLE);
941 if (!gfs2_ail_flush_reqd(sdp) &&
942 !gfs2_jrnl_flush_reqd(sdp) &&
943 !kthread_should_stop())
944 t = schedule_timeout(t);
945 } while(t && !gfs2_ail_flush_reqd(sdp) &&
946 !gfs2_jrnl_flush_reqd(sdp) &&
947 !kthread_should_stop());
948 finish_wait(&sdp->sd_logd_waitq, &wait);
949 }
950
951 return 0;
952}
953