xref: /linux/fs/gfs2/log.c (revision 37744feebc086908fd89760650f458ab19071750)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
4  * Copyright (C) 2004-2007 Red Hat, Inc.  All rights reserved.
5  */
6 
7 #include <linux/sched.h>
8 #include <linux/slab.h>
9 #include <linux/spinlock.h>
10 #include <linux/completion.h>
11 #include <linux/buffer_head.h>
12 #include <linux/gfs2_ondisk.h>
13 #include <linux/crc32.h>
14 #include <linux/crc32c.h>
15 #include <linux/delay.h>
16 #include <linux/kthread.h>
17 #include <linux/freezer.h>
18 #include <linux/bio.h>
19 #include <linux/blkdev.h>
20 #include <linux/writeback.h>
21 #include <linux/list_sort.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 static void gfs2_log_shutdown(struct gfs2_sbd *sdp);
35 
36 /**
37  * gfs2_struct2blk - compute stuff
38  * @sdp: the filesystem
39  * @nstruct: the number of 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 
47 unsigned int gfs2_struct2blk(struct gfs2_sbd *sdp, unsigned int nstruct)
48 {
49 	unsigned int blks;
50 	unsigned int first, second;
51 
52 	blks = 1;
53 	first = sdp->sd_ldptrs;
54 
55 	if (nstruct > first) {
56 		second = sdp->sd_inptrs;
57 		blks += DIV_ROUND_UP(nstruct - first, second);
58 	}
59 
60 	return blks;
61 }
62 
63 /**
64  * gfs2_remove_from_ail - Remove an entry from the ail lists, updating counters
65  * @mapping: The associated mapping (maybe NULL)
66  * @bd: The gfs2_bufdata to remove
67  *
68  * The ail lock _must_ be held when calling this function
69  *
70  */
71 
72 static void gfs2_remove_from_ail(struct gfs2_bufdata *bd)
73 {
74 	bd->bd_tr = NULL;
75 	list_del_init(&bd->bd_ail_st_list);
76 	list_del_init(&bd->bd_ail_gl_list);
77 	atomic_dec(&bd->bd_gl->gl_ail_count);
78 	brelse(bd->bd_bh);
79 }
80 
81 /**
82  * gfs2_ail1_start_one - Start I/O on a part of the AIL
83  * @sdp: the filesystem
84  * @wbc: The writeback control structure
85  * @ai: The ail structure
86  *
87  */
88 
89 static int gfs2_ail1_start_one(struct gfs2_sbd *sdp,
90 			       struct writeback_control *wbc,
91 			       struct gfs2_trans *tr)
92 __releases(&sdp->sd_ail_lock)
93 __acquires(&sdp->sd_ail_lock)
94 {
95 	struct gfs2_glock *gl = NULL;
96 	struct address_space *mapping;
97 	struct gfs2_bufdata *bd, *s;
98 	struct buffer_head *bh;
99 	int ret = 0;
100 
101 	list_for_each_entry_safe_reverse(bd, s, &tr->tr_ail1_list, bd_ail_st_list) {
102 		bh = bd->bd_bh;
103 
104 		gfs2_assert(sdp, bd->bd_tr == tr);
105 
106 		if (!buffer_busy(bh)) {
107 			if (buffer_uptodate(bh)) {
108 				list_move(&bd->bd_ail_st_list,
109 					  &tr->tr_ail2_list);
110 				continue;
111 			}
112 			if (!cmpxchg(&sdp->sd_log_error, 0, -EIO)) {
113 				gfs2_io_error_bh(sdp, bh);
114 				gfs2_withdraw_delayed(sdp);
115 			}
116 		}
117 
118 		if (gfs2_withdrawn(sdp)) {
119 			gfs2_remove_from_ail(bd);
120 			continue;
121 		}
122 		if (!buffer_dirty(bh))
123 			continue;
124 		if (gl == bd->bd_gl)
125 			continue;
126 		gl = bd->bd_gl;
127 		list_move(&bd->bd_ail_st_list, &tr->tr_ail1_list);
128 		mapping = bh->b_page->mapping;
129 		if (!mapping)
130 			continue;
131 		spin_unlock(&sdp->sd_ail_lock);
132 		ret = generic_writepages(mapping, wbc);
133 		spin_lock(&sdp->sd_ail_lock);
134 		if (ret || wbc->nr_to_write <= 0)
135 			break;
136 		return -EBUSY;
137 	}
138 
139 	return ret;
140 }
141 
142 static void dump_ail_list(struct gfs2_sbd *sdp)
143 {
144 	struct gfs2_trans *tr;
145 	struct gfs2_bufdata *bd;
146 	struct buffer_head *bh;
147 
148 	fs_err(sdp, "Error: In gfs2_ail1_flush for ten minutes! t=%d\n",
149 	       current->journal_info ? 1 : 0);
150 
151 	list_for_each_entry_reverse(tr, &sdp->sd_ail1_list, tr_list) {
152 		list_for_each_entry_reverse(bd, &tr->tr_ail1_list,
153 					    bd_ail_st_list) {
154 			bh = bd->bd_bh;
155 			fs_err(sdp, "bd %p: blk:0x%llx bh=%p ", bd,
156 			       (unsigned long long)bd->bd_blkno, bh);
157 			if (!bh) {
158 				fs_err(sdp, "\n");
159 				continue;
160 			}
161 			fs_err(sdp, "0x%llx up2:%d dirt:%d lkd:%d req:%d "
162 			       "map:%d new:%d ar:%d aw:%d delay:%d "
163 			       "io err:%d unwritten:%d dfr:%d pin:%d esc:%d\n",
164 			       (unsigned long long)bh->b_blocknr,
165 			       buffer_uptodate(bh), buffer_dirty(bh),
166 			       buffer_locked(bh), buffer_req(bh),
167 			       buffer_mapped(bh), buffer_new(bh),
168 			       buffer_async_read(bh), buffer_async_write(bh),
169 			       buffer_delay(bh), buffer_write_io_error(bh),
170 			       buffer_unwritten(bh),
171 			       buffer_defer_completion(bh),
172 			       buffer_pinned(bh), buffer_escaped(bh));
173 		}
174 	}
175 }
176 
177 /**
178  * gfs2_ail1_flush - start writeback of some ail1 entries
179  * @sdp: The super block
180  * @wbc: The writeback control structure
181  *
182  * Writes back some ail1 entries, according to the limits in the
183  * writeback control structure
184  */
185 
186 void gfs2_ail1_flush(struct gfs2_sbd *sdp, struct writeback_control *wbc)
187 {
188 	struct list_head *head = &sdp->sd_ail1_list;
189 	struct gfs2_trans *tr;
190 	struct blk_plug plug;
191 	int ret;
192 	unsigned long flush_start = jiffies;
193 
194 	trace_gfs2_ail_flush(sdp, wbc, 1);
195 	blk_start_plug(&plug);
196 	spin_lock(&sdp->sd_ail_lock);
197 restart:
198 	ret = 0;
199 	if (time_after(jiffies, flush_start + (HZ * 600))) {
200 		dump_ail_list(sdp);
201 		goto out;
202 	}
203 	list_for_each_entry_reverse(tr, head, tr_list) {
204 		if (wbc->nr_to_write <= 0)
205 			break;
206 		ret = gfs2_ail1_start_one(sdp, wbc, tr);
207 		if (ret) {
208 			if (ret == -EBUSY)
209 				goto restart;
210 			break;
211 		}
212 	}
213 out:
214 	spin_unlock(&sdp->sd_ail_lock);
215 	blk_finish_plug(&plug);
216 	if (ret) {
217 		gfs2_lm(sdp, "gfs2_ail1_start_one (generic_writepages) "
218 			"returned: %d\n", ret);
219 		gfs2_withdraw(sdp);
220 	}
221 	trace_gfs2_ail_flush(sdp, wbc, 0);
222 }
223 
224 /**
225  * gfs2_ail1_start - start writeback of all ail1 entries
226  * @sdp: The superblock
227  */
228 
229 static void gfs2_ail1_start(struct gfs2_sbd *sdp)
230 {
231 	struct writeback_control wbc = {
232 		.sync_mode = WB_SYNC_NONE,
233 		.nr_to_write = LONG_MAX,
234 		.range_start = 0,
235 		.range_end = LLONG_MAX,
236 	};
237 
238 	return gfs2_ail1_flush(sdp, &wbc);
239 }
240 
241 /**
242  * gfs2_ail1_empty_one - Check whether or not a trans in the AIL has been synced
243  * @sdp: the filesystem
244  * @tr: the transaction
245  * @max_revokes: If nonzero, issue revokes for the bd items for written buffers
246  *
247  */
248 
249 static void gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_trans *tr,
250 				int *max_revokes)
251 {
252 	struct gfs2_bufdata *bd, *s;
253 	struct buffer_head *bh;
254 
255 	list_for_each_entry_safe_reverse(bd, s, &tr->tr_ail1_list,
256 					 bd_ail_st_list) {
257 		bh = bd->bd_bh;
258 		gfs2_assert(sdp, bd->bd_tr == tr);
259 		/*
260 		 * If another process flagged an io error, e.g. writing to the
261 		 * journal, error all other bhs and move them off the ail1 to
262 		 * prevent a tight loop when unmount tries to flush ail1,
263 		 * regardless of whether they're still busy. If no outside
264 		 * errors were found and the buffer is busy, move to the next.
265 		 * If the ail buffer is not busy and caught an error, flag it
266 		 * for others.
267 		 */
268 		if (!sdp->sd_log_error && buffer_busy(bh))
269 			continue;
270 		if (!buffer_uptodate(bh) &&
271 		    !cmpxchg(&sdp->sd_log_error, 0, -EIO)) {
272 			gfs2_io_error_bh(sdp, bh);
273 			gfs2_withdraw_delayed(sdp);
274 		}
275 		/*
276 		 * If we have space for revokes and the bd is no longer on any
277 		 * buf list, we can just add a revoke for it immediately and
278 		 * avoid having to put it on the ail2 list, where it would need
279 		 * to be revoked later.
280 		 */
281 		if (*max_revokes && list_empty(&bd->bd_list)) {
282 			gfs2_add_revoke(sdp, bd);
283 			(*max_revokes)--;
284 			continue;
285 		}
286 		list_move(&bd->bd_ail_st_list, &tr->tr_ail2_list);
287 	}
288 }
289 
290 /**
291  * gfs2_ail1_empty - Try to empty the ail1 lists
292  * @sdp: The superblock
293  * @max_revokes: If non-zero, add revokes where appropriate
294  *
295  * Tries to empty the ail1 lists, starting with the oldest first
296  */
297 
298 static int gfs2_ail1_empty(struct gfs2_sbd *sdp, int max_revokes)
299 {
300 	struct gfs2_trans *tr, *s;
301 	int oldest_tr = 1;
302 	int ret;
303 
304 	spin_lock(&sdp->sd_ail_lock);
305 	list_for_each_entry_safe_reverse(tr, s, &sdp->sd_ail1_list, tr_list) {
306 		gfs2_ail1_empty_one(sdp, tr, &max_revokes);
307 		if (list_empty(&tr->tr_ail1_list) && oldest_tr)
308 			list_move(&tr->tr_list, &sdp->sd_ail2_list);
309 		else
310 			oldest_tr = 0;
311 	}
312 	ret = list_empty(&sdp->sd_ail1_list);
313 	spin_unlock(&sdp->sd_ail_lock);
314 
315 	if (test_bit(SDF_WITHDRAWING, &sdp->sd_flags)) {
316 		gfs2_lm(sdp, "fatal: I/O error(s)\n");
317 		gfs2_withdraw(sdp);
318 	}
319 
320 	return ret;
321 }
322 
323 static void gfs2_ail1_wait(struct gfs2_sbd *sdp)
324 {
325 	struct gfs2_trans *tr;
326 	struct gfs2_bufdata *bd;
327 	struct buffer_head *bh;
328 
329 	spin_lock(&sdp->sd_ail_lock);
330 	list_for_each_entry_reverse(tr, &sdp->sd_ail1_list, tr_list) {
331 		list_for_each_entry(bd, &tr->tr_ail1_list, bd_ail_st_list) {
332 			bh = bd->bd_bh;
333 			if (!buffer_locked(bh))
334 				continue;
335 			get_bh(bh);
336 			spin_unlock(&sdp->sd_ail_lock);
337 			wait_on_buffer(bh);
338 			brelse(bh);
339 			return;
340 		}
341 	}
342 	spin_unlock(&sdp->sd_ail_lock);
343 }
344 
345 /**
346  * gfs2_ail_empty_tr - empty one of the ail lists for a transaction
347  */
348 
349 static void gfs2_ail_empty_tr(struct gfs2_sbd *sdp, struct gfs2_trans *tr,
350 			      struct list_head *head)
351 {
352 	struct gfs2_bufdata *bd;
353 
354 	while (!list_empty(head)) {
355 		bd = list_first_entry(head, struct gfs2_bufdata,
356 				      bd_ail_st_list);
357 		gfs2_assert(sdp, bd->bd_tr == tr);
358 		gfs2_remove_from_ail(bd);
359 	}
360 }
361 
362 static void ail2_empty(struct gfs2_sbd *sdp, unsigned int new_tail)
363 {
364 	struct gfs2_trans *tr, *safe;
365 	unsigned int old_tail = sdp->sd_log_tail;
366 	int wrap = (new_tail < old_tail);
367 	int a, b, rm;
368 
369 	spin_lock(&sdp->sd_ail_lock);
370 
371 	list_for_each_entry_safe(tr, safe, &sdp->sd_ail2_list, tr_list) {
372 		a = (old_tail <= tr->tr_first);
373 		b = (tr->tr_first < new_tail);
374 		rm = (wrap) ? (a || b) : (a && b);
375 		if (!rm)
376 			continue;
377 
378 		gfs2_ail_empty_tr(sdp, tr, &tr->tr_ail2_list);
379 		list_del(&tr->tr_list);
380 		gfs2_assert_warn(sdp, list_empty(&tr->tr_ail1_list));
381 		gfs2_assert_warn(sdp, list_empty(&tr->tr_ail2_list));
382 		kfree(tr);
383 	}
384 
385 	spin_unlock(&sdp->sd_ail_lock);
386 }
387 
388 /**
389  * gfs2_log_release - Release a given number of log blocks
390  * @sdp: The GFS2 superblock
391  * @blks: The number of blocks
392  *
393  */
394 
395 void gfs2_log_release(struct gfs2_sbd *sdp, unsigned int blks)
396 {
397 
398 	atomic_add(blks, &sdp->sd_log_blks_free);
399 	trace_gfs2_log_blocks(sdp, blks);
400 	gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <=
401 				  sdp->sd_jdesc->jd_blocks);
402 	up_read(&sdp->sd_log_flush_lock);
403 }
404 
405 /**
406  * gfs2_log_reserve - Make a log reservation
407  * @sdp: The GFS2 superblock
408  * @blks: The number of blocks to reserve
409  *
410  * Note that we never give out the last few blocks of the journal. Thats
411  * due to the fact that there is a small number of header blocks
412  * associated with each log flush. The exact number can't be known until
413  * flush time, so we ensure that we have just enough free blocks at all
414  * times to avoid running out during a log flush.
415  *
416  * We no longer flush the log here, instead we wake up logd to do that
417  * for us. To avoid the thundering herd and to ensure that we deal fairly
418  * with queued waiters, we use an exclusive wait. This means that when we
419  * get woken with enough journal space to get our reservation, we need to
420  * wake the next waiter on the list.
421  *
422  * Returns: errno
423  */
424 
425 int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks)
426 {
427 	int ret = 0;
428 	unsigned reserved_blks = 7 * (4096 / sdp->sd_vfs->s_blocksize);
429 	unsigned wanted = blks + reserved_blks;
430 	DEFINE_WAIT(wait);
431 	int did_wait = 0;
432 	unsigned int free_blocks;
433 
434 	if (gfs2_assert_warn(sdp, blks) ||
435 	    gfs2_assert_warn(sdp, blks <= sdp->sd_jdesc->jd_blocks))
436 		return -EINVAL;
437 	atomic_add(blks, &sdp->sd_log_blks_needed);
438 retry:
439 	free_blocks = atomic_read(&sdp->sd_log_blks_free);
440 	if (unlikely(free_blocks <= wanted)) {
441 		do {
442 			prepare_to_wait_exclusive(&sdp->sd_log_waitq, &wait,
443 					TASK_UNINTERRUPTIBLE);
444 			wake_up(&sdp->sd_logd_waitq);
445 			did_wait = 1;
446 			if (atomic_read(&sdp->sd_log_blks_free) <= wanted)
447 				io_schedule();
448 			free_blocks = atomic_read(&sdp->sd_log_blks_free);
449 		} while(free_blocks <= wanted);
450 		finish_wait(&sdp->sd_log_waitq, &wait);
451 	}
452 	atomic_inc(&sdp->sd_reserving_log);
453 	if (atomic_cmpxchg(&sdp->sd_log_blks_free, free_blocks,
454 				free_blocks - blks) != free_blocks) {
455 		if (atomic_dec_and_test(&sdp->sd_reserving_log))
456 			wake_up(&sdp->sd_reserving_log_wait);
457 		goto retry;
458 	}
459 	atomic_sub(blks, &sdp->sd_log_blks_needed);
460 	trace_gfs2_log_blocks(sdp, -blks);
461 
462 	/*
463 	 * If we waited, then so might others, wake them up _after_ we get
464 	 * our share of the log.
465 	 */
466 	if (unlikely(did_wait))
467 		wake_up(&sdp->sd_log_waitq);
468 
469 	down_read(&sdp->sd_log_flush_lock);
470 	if (unlikely(!test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags))) {
471 		gfs2_log_release(sdp, blks);
472 		ret = -EROFS;
473 	}
474 	if (atomic_dec_and_test(&sdp->sd_reserving_log))
475 		wake_up(&sdp->sd_reserving_log_wait);
476 	return ret;
477 }
478 
479 /**
480  * log_distance - Compute distance between two journal blocks
481  * @sdp: The GFS2 superblock
482  * @newer: The most recent journal block of the pair
483  * @older: The older journal block of the pair
484  *
485  *   Compute the distance (in the journal direction) between two
486  *   blocks in the journal
487  *
488  * Returns: the distance in blocks
489  */
490 
491 static inline unsigned int log_distance(struct gfs2_sbd *sdp, unsigned int newer,
492 					unsigned int older)
493 {
494 	int dist;
495 
496 	dist = newer - older;
497 	if (dist < 0)
498 		dist += sdp->sd_jdesc->jd_blocks;
499 
500 	return dist;
501 }
502 
503 /**
504  * calc_reserved - Calculate the number of blocks to reserve when
505  *                 refunding a transaction's unused buffers.
506  * @sdp: The GFS2 superblock
507  *
508  * This is complex.  We need to reserve room for all our currently used
509  * metadata buffers (e.g. normal file I/O rewriting file time stamps) and
510  * all our journaled data buffers for journaled files (e.g. files in the
511  * meta_fs like rindex, or files for which chattr +j was done.)
512  * If we don't reserve enough space, gfs2_log_refund and gfs2_log_flush
513  * will count it as free space (sd_log_blks_free) and corruption will follow.
514  *
515  * We can have metadata bufs and jdata bufs in the same journal.  So each
516  * type gets its own log header, for which we need to reserve a block.
517  * In fact, each type has the potential for needing more than one header
518  * in cases where we have more buffers than will fit on a journal page.
519  * Metadata journal entries take up half the space of journaled buffer entries.
520  * Thus, metadata entries have buf_limit (502) and journaled buffers have
521  * databuf_limit (251) before they cause a wrap around.
522  *
523  * Also, we need to reserve blocks for revoke journal entries and one for an
524  * overall header for the lot.
525  *
526  * Returns: the number of blocks reserved
527  */
528 static unsigned int calc_reserved(struct gfs2_sbd *sdp)
529 {
530 	unsigned int reserved = 0;
531 	unsigned int mbuf;
532 	unsigned int dbuf;
533 	struct gfs2_trans *tr = sdp->sd_log_tr;
534 
535 	if (tr) {
536 		mbuf = tr->tr_num_buf_new - tr->tr_num_buf_rm;
537 		dbuf = tr->tr_num_databuf_new - tr->tr_num_databuf_rm;
538 		reserved = mbuf + dbuf;
539 		/* Account for header blocks */
540 		reserved += DIV_ROUND_UP(mbuf, buf_limit(sdp));
541 		reserved += DIV_ROUND_UP(dbuf, databuf_limit(sdp));
542 	}
543 
544 	if (sdp->sd_log_committed_revoke > 0)
545 		reserved += gfs2_struct2blk(sdp, sdp->sd_log_committed_revoke);
546 	/* One for the overall header */
547 	if (reserved)
548 		reserved++;
549 	return reserved;
550 }
551 
552 static unsigned int current_tail(struct gfs2_sbd *sdp)
553 {
554 	struct gfs2_trans *tr;
555 	unsigned int tail;
556 
557 	spin_lock(&sdp->sd_ail_lock);
558 
559 	if (list_empty(&sdp->sd_ail1_list)) {
560 		tail = sdp->sd_log_head;
561 	} else {
562 		tr = list_last_entry(&sdp->sd_ail1_list, struct gfs2_trans,
563 				tr_list);
564 		tail = tr->tr_first;
565 	}
566 
567 	spin_unlock(&sdp->sd_ail_lock);
568 
569 	return tail;
570 }
571 
572 static 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 void log_flush_wait(struct gfs2_sbd *sdp)
588 {
589 	DEFINE_WAIT(wait);
590 
591 	if (atomic_read(&sdp->sd_log_in_flight)) {
592 		do {
593 			prepare_to_wait(&sdp->sd_log_flush_wait, &wait,
594 					TASK_UNINTERRUPTIBLE);
595 			if (atomic_read(&sdp->sd_log_in_flight))
596 				io_schedule();
597 		} while(atomic_read(&sdp->sd_log_in_flight));
598 		finish_wait(&sdp->sd_log_flush_wait, &wait);
599 	}
600 }
601 
602 static int ip_cmp(void *priv, struct list_head *a, struct list_head *b)
603 {
604 	struct gfs2_inode *ipa, *ipb;
605 
606 	ipa = list_entry(a, struct gfs2_inode, i_ordered);
607 	ipb = list_entry(b, struct gfs2_inode, i_ordered);
608 
609 	if (ipa->i_no_addr < ipb->i_no_addr)
610 		return -1;
611 	if (ipa->i_no_addr > ipb->i_no_addr)
612 		return 1;
613 	return 0;
614 }
615 
616 static void gfs2_ordered_write(struct gfs2_sbd *sdp)
617 {
618 	struct gfs2_inode *ip;
619 	LIST_HEAD(written);
620 
621 	spin_lock(&sdp->sd_ordered_lock);
622 	list_sort(NULL, &sdp->sd_log_ordered, &ip_cmp);
623 	while (!list_empty(&sdp->sd_log_ordered)) {
624 		ip = list_first_entry(&sdp->sd_log_ordered, struct gfs2_inode, i_ordered);
625 		if (ip->i_inode.i_mapping->nrpages == 0) {
626 			test_and_clear_bit(GIF_ORDERED, &ip->i_flags);
627 			list_del(&ip->i_ordered);
628 			continue;
629 		}
630 		list_move(&ip->i_ordered, &written);
631 		spin_unlock(&sdp->sd_ordered_lock);
632 		filemap_fdatawrite(ip->i_inode.i_mapping);
633 		spin_lock(&sdp->sd_ordered_lock);
634 	}
635 	list_splice(&written, &sdp->sd_log_ordered);
636 	spin_unlock(&sdp->sd_ordered_lock);
637 }
638 
639 static void gfs2_ordered_wait(struct gfs2_sbd *sdp)
640 {
641 	struct gfs2_inode *ip;
642 
643 	spin_lock(&sdp->sd_ordered_lock);
644 	while (!list_empty(&sdp->sd_log_ordered)) {
645 		ip = list_first_entry(&sdp->sd_log_ordered, struct gfs2_inode, i_ordered);
646 		list_del(&ip->i_ordered);
647 		WARN_ON(!test_and_clear_bit(GIF_ORDERED, &ip->i_flags));
648 		if (ip->i_inode.i_mapping->nrpages == 0)
649 			continue;
650 		spin_unlock(&sdp->sd_ordered_lock);
651 		filemap_fdatawait(ip->i_inode.i_mapping);
652 		spin_lock(&sdp->sd_ordered_lock);
653 	}
654 	spin_unlock(&sdp->sd_ordered_lock);
655 }
656 
657 void gfs2_ordered_del_inode(struct gfs2_inode *ip)
658 {
659 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
660 
661 	spin_lock(&sdp->sd_ordered_lock);
662 	if (test_and_clear_bit(GIF_ORDERED, &ip->i_flags))
663 		list_del(&ip->i_ordered);
664 	spin_unlock(&sdp->sd_ordered_lock);
665 }
666 
667 void gfs2_add_revoke(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd)
668 {
669 	struct buffer_head *bh = bd->bd_bh;
670 	struct gfs2_glock *gl = bd->bd_gl;
671 
672 	sdp->sd_log_num_revoke++;
673 	if (atomic_inc_return(&gl->gl_revokes) == 1)
674 		gfs2_glock_hold(gl);
675 	bh->b_private = NULL;
676 	bd->bd_blkno = bh->b_blocknr;
677 	gfs2_remove_from_ail(bd); /* drops ref on bh */
678 	bd->bd_bh = NULL;
679 	set_bit(GLF_LFLUSH, &gl->gl_flags);
680 	list_add(&bd->bd_list, &sdp->sd_log_revokes);
681 }
682 
683 void gfs2_glock_remove_revoke(struct gfs2_glock *gl)
684 {
685 	if (atomic_dec_return(&gl->gl_revokes) == 0) {
686 		clear_bit(GLF_LFLUSH, &gl->gl_flags);
687 		gfs2_glock_queue_put(gl);
688 	}
689 }
690 
691 /**
692  * gfs2_write_revokes - Add as many revokes to the system transaction as we can
693  * @sdp: The GFS2 superblock
694  *
695  * Our usual strategy is to defer writing revokes as much as we can in the hope
696  * that we'll eventually overwrite the journal, which will make those revokes
697  * go away.  This changes when we flush the log: at that point, there will
698  * likely be some left-over space in the last revoke block of that transaction.
699  * We can fill that space with additional revokes for blocks that have already
700  * been written back.  This will basically come at no cost now, and will save
701  * us from having to keep track of those blocks on the AIL2 list later.
702  */
703 void gfs2_write_revokes(struct gfs2_sbd *sdp)
704 {
705 	/* number of revokes we still have room for */
706 	int max_revokes = (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_log_descriptor)) / sizeof(u64);
707 
708 	gfs2_log_lock(sdp);
709 	while (sdp->sd_log_num_revoke > max_revokes)
710 		max_revokes += (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_meta_header)) / sizeof(u64);
711 	max_revokes -= sdp->sd_log_num_revoke;
712 	if (!sdp->sd_log_num_revoke) {
713 		atomic_dec(&sdp->sd_log_blks_free);
714 		/* If no blocks have been reserved, we need to also
715 		 * reserve a block for the header */
716 		if (!sdp->sd_log_blks_reserved)
717 			atomic_dec(&sdp->sd_log_blks_free);
718 	}
719 	gfs2_ail1_empty(sdp, max_revokes);
720 	gfs2_log_unlock(sdp);
721 
722 	if (!sdp->sd_log_num_revoke) {
723 		atomic_inc(&sdp->sd_log_blks_free);
724 		if (!sdp->sd_log_blks_reserved)
725 			atomic_inc(&sdp->sd_log_blks_free);
726 	}
727 }
728 
729 /**
730  * gfs2_write_log_header - Write a journal log header buffer at lblock
731  * @sdp: The GFS2 superblock
732  * @jd: journal descriptor of the journal to which we are writing
733  * @seq: sequence number
734  * @tail: tail of the log
735  * @lblock: value for lh_blkno (block number relative to start of journal)
736  * @flags: log header flags GFS2_LOG_HEAD_*
737  * @op_flags: flags to pass to the bio
738  *
739  * Returns: the initialized log buffer descriptor
740  */
741 
742 void gfs2_write_log_header(struct gfs2_sbd *sdp, struct gfs2_jdesc *jd,
743 			   u64 seq, u32 tail, u32 lblock, u32 flags,
744 			   int op_flags)
745 {
746 	struct gfs2_log_header *lh;
747 	u32 hash, crc;
748 	struct page *page;
749 	struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
750 	struct timespec64 tv;
751 	struct super_block *sb = sdp->sd_vfs;
752 	u64 dblock;
753 
754 	if (gfs2_withdrawn(sdp))
755 		goto out;
756 
757 	page = mempool_alloc(gfs2_page_pool, GFP_NOIO);
758 	lh = page_address(page);
759 	clear_page(lh);
760 
761 	lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
762 	lh->lh_header.mh_type = cpu_to_be32(GFS2_METATYPE_LH);
763 	lh->lh_header.__pad0 = cpu_to_be64(0);
764 	lh->lh_header.mh_format = cpu_to_be32(GFS2_FORMAT_LH);
765 	lh->lh_header.mh_jid = cpu_to_be32(sdp->sd_jdesc->jd_jid);
766 	lh->lh_sequence = cpu_to_be64(seq);
767 	lh->lh_flags = cpu_to_be32(flags);
768 	lh->lh_tail = cpu_to_be32(tail);
769 	lh->lh_blkno = cpu_to_be32(lblock);
770 	hash = ~crc32(~0, lh, LH_V1_SIZE);
771 	lh->lh_hash = cpu_to_be32(hash);
772 
773 	ktime_get_coarse_real_ts64(&tv);
774 	lh->lh_nsec = cpu_to_be32(tv.tv_nsec);
775 	lh->lh_sec = cpu_to_be64(tv.tv_sec);
776 	if (!list_empty(&jd->extent_list))
777 		dblock = gfs2_log_bmap(jd, lblock);
778 	else {
779 		int ret = gfs2_lblk_to_dblk(jd->jd_inode, lblock, &dblock);
780 		if (gfs2_assert_withdraw(sdp, ret == 0))
781 			return;
782 	}
783 	lh->lh_addr = cpu_to_be64(dblock);
784 	lh->lh_jinode = cpu_to_be64(GFS2_I(jd->jd_inode)->i_no_addr);
785 
786 	/* We may only write local statfs, quota, etc., when writing to our
787 	   own journal. The values are left 0 when recovering a journal
788 	   different from our own. */
789 	if (!(flags & GFS2_LOG_HEAD_RECOVERY)) {
790 		lh->lh_statfs_addr =
791 			cpu_to_be64(GFS2_I(sdp->sd_sc_inode)->i_no_addr);
792 		lh->lh_quota_addr =
793 			cpu_to_be64(GFS2_I(sdp->sd_qc_inode)->i_no_addr);
794 
795 		spin_lock(&sdp->sd_statfs_spin);
796 		lh->lh_local_total = cpu_to_be64(l_sc->sc_total);
797 		lh->lh_local_free = cpu_to_be64(l_sc->sc_free);
798 		lh->lh_local_dinodes = cpu_to_be64(l_sc->sc_dinodes);
799 		spin_unlock(&sdp->sd_statfs_spin);
800 	}
801 
802 	BUILD_BUG_ON(offsetof(struct gfs2_log_header, lh_crc) != LH_V1_SIZE);
803 
804 	crc = crc32c(~0, (void *)lh + LH_V1_SIZE + 4,
805 		     sb->s_blocksize - LH_V1_SIZE - 4);
806 	lh->lh_crc = cpu_to_be32(crc);
807 
808 	gfs2_log_write(sdp, page, sb->s_blocksize, 0, dblock);
809 	gfs2_log_submit_bio(&sdp->sd_log_bio, REQ_OP_WRITE | op_flags);
810 out:
811 	log_flush_wait(sdp);
812 }
813 
814 /**
815  * log_write_header - Get and initialize a journal header buffer
816  * @sdp: The GFS2 superblock
817  * @flags: The log header flags, including log header origin
818  *
819  * Returns: the initialized log buffer descriptor
820  */
821 
822 static void log_write_header(struct gfs2_sbd *sdp, u32 flags)
823 {
824 	unsigned int tail;
825 	int op_flags = REQ_PREFLUSH | REQ_FUA | REQ_META | REQ_SYNC;
826 	enum gfs2_freeze_state state = atomic_read(&sdp->sd_freeze_state);
827 
828 	gfs2_assert_withdraw(sdp, (state != SFS_FROZEN));
829 	tail = current_tail(sdp);
830 
831 	if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags)) {
832 		gfs2_ordered_wait(sdp);
833 		log_flush_wait(sdp);
834 		op_flags = REQ_SYNC | REQ_META | REQ_PRIO;
835 	}
836 	sdp->sd_log_idle = (tail == sdp->sd_log_flush_head);
837 	gfs2_write_log_header(sdp, sdp->sd_jdesc, sdp->sd_log_sequence++, tail,
838 			      sdp->sd_log_flush_head, flags, op_flags);
839 	gfs2_log_incr_head(sdp);
840 
841 	if (sdp->sd_log_tail != tail)
842 		log_pull_tail(sdp, tail);
843 }
844 
845 /**
846  * ail_drain - drain the ail lists after a withdraw
847  * @sdp: Pointer to GFS2 superblock
848  */
849 static void ail_drain(struct gfs2_sbd *sdp)
850 {
851 	struct gfs2_trans *tr;
852 
853 	spin_lock(&sdp->sd_ail_lock);
854 	/*
855 	 * For transactions on the sd_ail1_list we need to drain both the
856 	 * ail1 and ail2 lists. That's because function gfs2_ail1_start_one
857 	 * (temporarily) moves items from its tr_ail1 list to tr_ail2 list
858 	 * before revokes are sent for that block. Items on the sd_ail2_list
859 	 * should have already gotten beyond that point, so no need.
860 	 */
861 	while (!list_empty(&sdp->sd_ail1_list)) {
862 		tr = list_first_entry(&sdp->sd_ail1_list, struct gfs2_trans,
863 				      tr_list);
864 		gfs2_ail_empty_tr(sdp, tr, &tr->tr_ail1_list);
865 		gfs2_ail_empty_tr(sdp, tr, &tr->tr_ail2_list);
866 		list_del(&tr->tr_list);
867 		kfree(tr);
868 	}
869 	while (!list_empty(&sdp->sd_ail2_list)) {
870 		tr = list_first_entry(&sdp->sd_ail2_list, struct gfs2_trans,
871 				      tr_list);
872 		gfs2_ail_empty_tr(sdp, tr, &tr->tr_ail2_list);
873 		list_del(&tr->tr_list);
874 		kfree(tr);
875 	}
876 	spin_unlock(&sdp->sd_ail_lock);
877 }
878 
879 /**
880  * gfs2_log_flush - flush incore transaction(s)
881  * @sdp: the filesystem
882  * @gl: The glock structure to flush.  If NULL, flush the whole incore log
883  * @flags: The log header flags: GFS2_LOG_HEAD_FLUSH_* and debug flags
884  *
885  */
886 
887 void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl, u32 flags)
888 {
889 	struct gfs2_trans *tr = NULL;
890 	enum gfs2_freeze_state state = atomic_read(&sdp->sd_freeze_state);
891 
892 	down_write(&sdp->sd_log_flush_lock);
893 
894 	/*
895 	 * Do this check while holding the log_flush_lock to prevent new
896 	 * buffers from being added to the ail via gfs2_pin()
897 	 */
898 	if (gfs2_withdrawn(sdp))
899 		goto out;
900 
901 	/* Log might have been flushed while we waited for the flush lock */
902 	if (gl && !test_bit(GLF_LFLUSH, &gl->gl_flags)) {
903 		up_write(&sdp->sd_log_flush_lock);
904 		return;
905 	}
906 	trace_gfs2_log_flush(sdp, 1, flags);
907 
908 	if (flags & GFS2_LOG_HEAD_FLUSH_SHUTDOWN)
909 		clear_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
910 
911 	sdp->sd_log_flush_head = sdp->sd_log_head;
912 	tr = sdp->sd_log_tr;
913 	if (tr) {
914 		sdp->sd_log_tr = NULL;
915 		INIT_LIST_HEAD(&tr->tr_ail1_list);
916 		INIT_LIST_HEAD(&tr->tr_ail2_list);
917 		tr->tr_first = sdp->sd_log_flush_head;
918 		if (unlikely (state == SFS_FROZEN))
919 			if (gfs2_assert_withdraw_delayed(sdp,
920 			       !tr->tr_num_buf_new && !tr->tr_num_databuf_new))
921 				goto out;
922 	}
923 
924 	if (unlikely(state == SFS_FROZEN))
925 		if (gfs2_assert_withdraw_delayed(sdp, !sdp->sd_log_num_revoke))
926 			goto out;
927 	if (gfs2_assert_withdraw_delayed(sdp,
928 			sdp->sd_log_num_revoke == sdp->sd_log_committed_revoke))
929 		goto out;
930 
931 	gfs2_ordered_write(sdp);
932 	if (gfs2_withdrawn(sdp))
933 		goto out;
934 	lops_before_commit(sdp, tr);
935 	if (gfs2_withdrawn(sdp))
936 		goto out;
937 	gfs2_log_submit_bio(&sdp->sd_log_bio, REQ_OP_WRITE);
938 	if (gfs2_withdrawn(sdp))
939 		goto out;
940 
941 	if (sdp->sd_log_head != sdp->sd_log_flush_head) {
942 		log_flush_wait(sdp);
943 		log_write_header(sdp, flags);
944 	} else if (sdp->sd_log_tail != current_tail(sdp) && !sdp->sd_log_idle){
945 		atomic_dec(&sdp->sd_log_blks_free); /* Adjust for unreserved buffer */
946 		trace_gfs2_log_blocks(sdp, -1);
947 		log_write_header(sdp, flags);
948 	}
949 	if (gfs2_withdrawn(sdp))
950 		goto out;
951 	lops_after_commit(sdp, tr);
952 
953 	gfs2_log_lock(sdp);
954 	sdp->sd_log_head = sdp->sd_log_flush_head;
955 	sdp->sd_log_blks_reserved = 0;
956 	sdp->sd_log_committed_revoke = 0;
957 
958 	spin_lock(&sdp->sd_ail_lock);
959 	if (tr && !list_empty(&tr->tr_ail1_list)) {
960 		list_add(&tr->tr_list, &sdp->sd_ail1_list);
961 		tr = NULL;
962 	}
963 	spin_unlock(&sdp->sd_ail_lock);
964 	gfs2_log_unlock(sdp);
965 
966 	if (!(flags & GFS2_LOG_HEAD_FLUSH_NORMAL)) {
967 		if (!sdp->sd_log_idle) {
968 			for (;;) {
969 				gfs2_ail1_start(sdp);
970 				gfs2_ail1_wait(sdp);
971 				if (gfs2_ail1_empty(sdp, 0))
972 					break;
973 			}
974 			if (gfs2_withdrawn(sdp))
975 				goto out;
976 			atomic_dec(&sdp->sd_log_blks_free); /* Adjust for unreserved buffer */
977 			trace_gfs2_log_blocks(sdp, -1);
978 			log_write_header(sdp, flags);
979 			sdp->sd_log_head = sdp->sd_log_flush_head;
980 		}
981 		if (flags & (GFS2_LOG_HEAD_FLUSH_SHUTDOWN |
982 			     GFS2_LOG_HEAD_FLUSH_FREEZE))
983 			gfs2_log_shutdown(sdp);
984 		if (flags & GFS2_LOG_HEAD_FLUSH_FREEZE)
985 			atomic_set(&sdp->sd_freeze_state, SFS_FROZEN);
986 	}
987 
988 out:
989 	if (gfs2_withdrawn(sdp)) {
990 		ail_drain(sdp); /* frees all transactions */
991 		tr = NULL;
992 	}
993 
994 	trace_gfs2_log_flush(sdp, 0, flags);
995 	up_write(&sdp->sd_log_flush_lock);
996 
997 	kfree(tr);
998 }
999 
1000 /**
1001  * gfs2_merge_trans - Merge a new transaction into a cached transaction
1002  * @old: Original transaction to be expanded
1003  * @new: New transaction to be merged
1004  */
1005 
1006 static void gfs2_merge_trans(struct gfs2_trans *old, struct gfs2_trans *new)
1007 {
1008 	WARN_ON_ONCE(!test_bit(TR_ATTACHED, &old->tr_flags));
1009 
1010 	old->tr_num_buf_new	+= new->tr_num_buf_new;
1011 	old->tr_num_databuf_new	+= new->tr_num_databuf_new;
1012 	old->tr_num_buf_rm	+= new->tr_num_buf_rm;
1013 	old->tr_num_databuf_rm	+= new->tr_num_databuf_rm;
1014 	old->tr_num_revoke	+= new->tr_num_revoke;
1015 	old->tr_num_revoke_rm	+= new->tr_num_revoke_rm;
1016 
1017 	list_splice_tail_init(&new->tr_databuf, &old->tr_databuf);
1018 	list_splice_tail_init(&new->tr_buf, &old->tr_buf);
1019 }
1020 
1021 static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
1022 {
1023 	unsigned int reserved;
1024 	unsigned int unused;
1025 	unsigned int maxres;
1026 
1027 	gfs2_log_lock(sdp);
1028 
1029 	if (sdp->sd_log_tr) {
1030 		gfs2_merge_trans(sdp->sd_log_tr, tr);
1031 	} else if (tr->tr_num_buf_new || tr->tr_num_databuf_new) {
1032 		gfs2_assert_withdraw(sdp, test_bit(TR_ALLOCED, &tr->tr_flags));
1033 		sdp->sd_log_tr = tr;
1034 		set_bit(TR_ATTACHED, &tr->tr_flags);
1035 	}
1036 
1037 	sdp->sd_log_committed_revoke += tr->tr_num_revoke - tr->tr_num_revoke_rm;
1038 	reserved = calc_reserved(sdp);
1039 	maxres = sdp->sd_log_blks_reserved + tr->tr_reserved;
1040 	gfs2_assert_withdraw(sdp, maxres >= reserved);
1041 	unused = maxres - reserved;
1042 	atomic_add(unused, &sdp->sd_log_blks_free);
1043 	trace_gfs2_log_blocks(sdp, unused);
1044 	gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <=
1045 			     sdp->sd_jdesc->jd_blocks);
1046 	sdp->sd_log_blks_reserved = reserved;
1047 
1048 	gfs2_log_unlock(sdp);
1049 }
1050 
1051 /**
1052  * gfs2_log_commit - Commit a transaction to the log
1053  * @sdp: the filesystem
1054  * @tr: the transaction
1055  *
1056  * We wake up gfs2_logd if the number of pinned blocks exceed thresh1
1057  * or the total number of used blocks (pinned blocks plus AIL blocks)
1058  * is greater than thresh2.
1059  *
1060  * At mount time thresh1 is 1/3rd of journal size, thresh2 is 2/3rd of
1061  * journal size.
1062  *
1063  * Returns: errno
1064  */
1065 
1066 void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
1067 {
1068 	log_refund(sdp, tr);
1069 
1070 	if (atomic_read(&sdp->sd_log_pinned) > atomic_read(&sdp->sd_log_thresh1) ||
1071 	    ((sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free)) >
1072 	    atomic_read(&sdp->sd_log_thresh2)))
1073 		wake_up(&sdp->sd_logd_waitq);
1074 }
1075 
1076 /**
1077  * gfs2_log_shutdown - write a shutdown header into a journal
1078  * @sdp: the filesystem
1079  *
1080  */
1081 
1082 static void gfs2_log_shutdown(struct gfs2_sbd *sdp)
1083 {
1084 	gfs2_assert_withdraw(sdp, !sdp->sd_log_blks_reserved);
1085 	gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke);
1086 	gfs2_assert_withdraw(sdp, list_empty(&sdp->sd_ail1_list));
1087 
1088 	sdp->sd_log_flush_head = sdp->sd_log_head;
1089 
1090 	log_write_header(sdp, GFS2_LOG_HEAD_UNMOUNT | GFS2_LFC_SHUTDOWN);
1091 
1092 	gfs2_assert_warn(sdp, sdp->sd_log_head == sdp->sd_log_tail);
1093 	gfs2_assert_warn(sdp, list_empty(&sdp->sd_ail2_list));
1094 
1095 	sdp->sd_log_head = sdp->sd_log_flush_head;
1096 	sdp->sd_log_tail = sdp->sd_log_head;
1097 }
1098 
1099 static inline int gfs2_jrnl_flush_reqd(struct gfs2_sbd *sdp)
1100 {
1101 	return (atomic_read(&sdp->sd_log_pinned) +
1102 		atomic_read(&sdp->sd_log_blks_needed) >=
1103 		atomic_read(&sdp->sd_log_thresh1));
1104 }
1105 
1106 static inline int gfs2_ail_flush_reqd(struct gfs2_sbd *sdp)
1107 {
1108 	unsigned int used_blocks = sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free);
1109 
1110 	if (test_and_clear_bit(SDF_FORCE_AIL_FLUSH, &sdp->sd_flags))
1111 		return 1;
1112 
1113 	return used_blocks + atomic_read(&sdp->sd_log_blks_needed) >=
1114 		atomic_read(&sdp->sd_log_thresh2);
1115 }
1116 
1117 /**
1118  * gfs2_logd - Update log tail as Active Items get flushed to in-place blocks
1119  * @sdp: Pointer to GFS2 superblock
1120  *
1121  * Also, periodically check to make sure that we're using the most recent
1122  * journal index.
1123  */
1124 
1125 int gfs2_logd(void *data)
1126 {
1127 	struct gfs2_sbd *sdp = data;
1128 	unsigned long t = 1;
1129 	DEFINE_WAIT(wait);
1130 	bool did_flush;
1131 
1132 	while (!kthread_should_stop()) {
1133 
1134 		if (gfs2_withdrawn(sdp)) {
1135 			msleep_interruptible(HZ);
1136 			continue;
1137 		}
1138 		/* Check for errors writing to the journal */
1139 		if (sdp->sd_log_error) {
1140 			gfs2_lm(sdp,
1141 				"GFS2: fsid=%s: error %d: "
1142 				"withdrawing the file system to "
1143 				"prevent further damage.\n",
1144 				sdp->sd_fsname, sdp->sd_log_error);
1145 			gfs2_withdraw(sdp);
1146 			continue;
1147 		}
1148 
1149 		did_flush = false;
1150 		if (gfs2_jrnl_flush_reqd(sdp) || t == 0) {
1151 			gfs2_ail1_empty(sdp, 0);
1152 			gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_NORMAL |
1153 				       GFS2_LFC_LOGD_JFLUSH_REQD);
1154 			did_flush = true;
1155 		}
1156 
1157 		if (gfs2_ail_flush_reqd(sdp)) {
1158 			gfs2_ail1_start(sdp);
1159 			gfs2_ail1_wait(sdp);
1160 			gfs2_ail1_empty(sdp, 0);
1161 			gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_NORMAL |
1162 				       GFS2_LFC_LOGD_AIL_FLUSH_REQD);
1163 			did_flush = true;
1164 		}
1165 
1166 		if (!gfs2_ail_flush_reqd(sdp) || did_flush)
1167 			wake_up(&sdp->sd_log_waitq);
1168 
1169 		t = gfs2_tune_get(sdp, gt_logd_secs) * HZ;
1170 
1171 		try_to_freeze();
1172 
1173 		do {
1174 			prepare_to_wait(&sdp->sd_logd_waitq, &wait,
1175 					TASK_INTERRUPTIBLE);
1176 			if (!gfs2_ail_flush_reqd(sdp) &&
1177 			    !gfs2_jrnl_flush_reqd(sdp) &&
1178 			    !kthread_should_stop())
1179 				t = schedule_timeout(t);
1180 		} while(t && !gfs2_ail_flush_reqd(sdp) &&
1181 			!gfs2_jrnl_flush_reqd(sdp) &&
1182 			!kthread_should_stop());
1183 		finish_wait(&sdp->sd_logd_waitq, &wait);
1184 	}
1185 
1186 	return 0;
1187 }
1188 
1189