aboutsummaryrefslogtreecommitdiff
path: root/fs/gfs2/log.c
blob: 8fce592f4011d97301aeb690cfdfb60a27bae967 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
/*
 * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
 * Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
 *
 * This copyrighted material is made available to anyone wishing to use,
 * modify, copy, or redistribute it subject to the terms and conditions
 * of the GNU General Public License version 2.
 */

#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/gfs2_ondisk.h>
#include <linux/crc32.h>

#include "gfs2.h"
#include "lm_interface.h"
#include "incore.h"
#include "bmap.h"
#include "glock.h"
#include "log.h"
#include "lops.h"
#include "meta_io.h"
#include "util.h"
#include "dir.h"

#define PULL 1

/**
 * gfs2_struct2blk - compute stuff
 * @sdp: the filesystem
 * @nstruct: the number of structures
 * @ssize: the size of the structures
 *
 * Compute the number of log descriptor blocks needed to hold a certain number
 * of structures of a certain size.
 *
 * Returns: the number of blocks needed (minimum is always 1)
 */

unsigned int gfs2_struct2blk(struct gfs2_sbd *sdp, unsigned int nstruct,
			     unsigned int ssize)
{
	unsigned int blks;
	unsigned int first, second;

	blks = 1;
	first = (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_log_descriptor)) /
		ssize;

	if (nstruct > first) {
		second = (sdp->sd_sb.sb_bsize -
			  sizeof(struct gfs2_meta_header)) / ssize;
		blks += DIV_ROUND_UP(nstruct - first, second);
	}

	return blks;
}

void gfs2_ail1_start(struct gfs2_sbd *sdp, int flags)
{
	struct list_head *head = &sdp->sd_ail1_list;
	u64 sync_gen;
	struct list_head *first, *tmp;
	struct gfs2_ail *first_ai, *ai;

	gfs2_log_lock(sdp);
	if (list_empty(head)) {
		gfs2_log_unlock(sdp);
		return;
	}
	sync_gen = sdp->sd_ail_sync_gen++;

	first = head->prev;
	first_ai = list_entry(first, struct gfs2_ail, ai_list);
	first_ai->ai_sync_gen = sync_gen;
	gfs2_ail1_start_one(sdp, first_ai);

	if (flags & DIO_ALL)
		first = NULL;

	for (;;) {
		if (first && (head->prev != first ||
			      gfs2_ail1_empty_one(sdp, first_ai, 0)))
			break;

		for (tmp = head->prev; tmp != head; tmp = tmp->prev) {
			ai = list_entry(tmp, struct gfs2_ail, ai_list);
			if (ai->ai_sync_gen >= sync_gen)
				continue;
			ai->ai_sync_gen = sync_gen;
			gfs2_ail1_start_one(sdp, ai);
			break;
		}

		if (tmp == head)
			break;
	}

	gfs2_log_unlock(sdp);
}

int gfs2_ail1_empty(struct gfs2_sbd *sdp, int flags)
{
	struct gfs2_ail *ai, *s;
	int ret;

	gfs2_log_lock(sdp);

	list_for_each_entry_safe_reverse(ai, s, &sdp->sd_ail1_list, ai_list) {
		if (gfs2_ail1_empty_one(sdp, ai, flags))
			list_move(&ai->ai_list, &sdp->sd_ail2_list);
		else if (!(flags & DIO_ALL))
			break;
	}

	ret = list_empty(&sdp->sd_ail1_list);

	gfs2_log_unlock(sdp);

	return ret;
}

static void ail2_empty(struct gfs2_sbd *sdp, unsigned int new_tail)
{
	struct gfs2_ail *ai, *safe;
	unsigned int old_tail = sdp->sd_log_tail;
	int wrap = (new_tail < old_tail);
	int a, b, rm;

	gfs2_log_lock(sdp);

	list_for_each_entry_safe(ai, safe, &sdp->sd_ail2_list, ai_list) {
		a = (old_tail <= ai->ai_first);
		b = (ai->ai_first < new_tail);
		rm = (wrap) ? (a || b) : (a && b);
		if (!rm)
			continue;

		gfs2_ail2_empty_one(sdp, ai);
		list_del(&ai->ai_list);
		gfs2_assert_warn(sdp, list_empty(&ai->ai_ail1_list));
		gfs2_assert_warn(sdp, list_empty(&ai->ai_ail2_list));
		kfree(ai);
	}

	gfs2_log_unlock(sdp);
}

/**
 * gfs2_log_reserve - Make a log reservation
 * @sdp: The GFS2 superblock
 * @blks: The number of blocks to reserve
 *
 * Returns: errno
 */

int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks)
{
	unsigned int try = 0;

	if (gfs2_assert_warn(sdp, blks) ||
	    gfs2_assert_warn(sdp, blks <= sdp->sd_jdesc->jd_blocks))
		return -EINVAL;

	mutex_lock(&sdp->sd_log_reserve_mutex);
	gfs2_log_lock(sdp);
	while(sdp->sd_log_blks_free <= blks) {
		gfs2_log_unlock(sdp);
		gfs2_ail1_empty(sdp, 0);
		gfs2_log_flush(sdp, NULL);

		if (try++)
			gfs2_ail1_start(sdp, 0);
		gfs2_log_lock(sdp);
	}
	sdp->sd_log_blks_free -= blks;
	gfs2_log_unlock(sdp);
	mutex_unlock(&sdp->sd_log_reserve_mutex);

	down_read(&sdp->sd_log_flush_lock);

	return 0;
}

/**
 * gfs2_log_release - Release a given number of log blocks
 * @sdp: The GFS2 superblock
 * @blks: The number of blocks
 *
 */

void gfs2_log_release(struct gfs2_sbd *sdp, unsigned int blks)
{

	gfs2_log_lock(sdp);
	sdp->sd_log_blks_free += blks;
	gfs2_assert_withdraw(sdp,
			     sdp->sd_log_blks_free <= sdp->sd_jdesc->jd_blocks);
	gfs2_log_unlock(sdp);
	up_read(&sdp->sd_log_flush_lock);
}

static u64 log_bmap(struct gfs2_sbd *sdp, unsigned int lbn)
{
	int new = 0;
	u64 dbn;
	int error;
	int bdy;

	error = gfs2_block_map(sdp->sd_jdesc->jd_inode, lbn, &new, &dbn, &bdy);
	if (error || !dbn)
		printk(KERN_INFO "error=%d, dbn=%llu lbn=%u", error, (unsigned long long)dbn, lbn);
	gfs2_assert_withdraw(sdp, !error && dbn);

	return dbn;
}

/**
 * log_distance - Compute distance between two journal blocks
 * @sdp: The GFS2 superblock
 * @newer: The most recent journal block of the pair
 * @older: The older journal block of the pair
 *
 *   Compute the distance (in the journal direction) between two
 *   blocks in the journal
 *
 * Returns: the distance in blocks
 */

static inline unsigned int log_distance(struct gfs2_sbd *sdp,
					unsigned int newer,
					unsigned int older)
{
	int dist;

	dist = newer - older;
	if (dist < 0)
		dist += sdp->sd_jdesc->jd_blocks;

	return dist;
}

static unsigned int current_tail(struct gfs2_sbd *sdp)
{
	struct gfs2_ail *ai;
	unsigned int tail;

	gfs2_log_lock(sdp);

	if (list_empty(&sdp->sd_ail1_list))
		tail = sdp->sd_log_head;
	else {
		ai = list_entry(sdp->sd_ail1_list.prev, struct gfs2_ail,
				ai_list);
		tail = ai->ai_first;
	}

	gfs2_log_unlock(sdp);

	return tail;
}

static inline void log_incr_head(struct gfs2_sbd *sdp)
{
	if (sdp->sd_log_flush_head == sdp->sd_log_tail)
		gfs2_assert_withdraw(sdp,
				sdp->sd_log_flush_head == sdp->sd_log_head);

	if (++sdp->sd_log_flush_head == sdp->sd_jdesc->jd_blocks) {
		sdp->sd_log_flush_head = 0;
		sdp->sd_log_flush_wrapped = 1;
	}
}

/**
 * gfs2_log_get_buf - Get and initialize a buffer to use for log control data
 * @sdp: The GFS2 superblock
 *
 * Returns: the buffer_head
 */

struct buffer_head *gfs2_log_get_buf(struct gfs2_sbd *sdp)
{
	u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head);
	struct gfs2_log_buf *lb;
	struct buffer_head *bh;

	lb = kzalloc(sizeof(struct gfs2_log_buf), GFP_NOFS | __GFP_NOFAIL);
	list_add(&lb->lb_list, &sdp->sd_log_flush_list);

	bh = lb->lb_bh = sb_getblk(sdp->sd_vfs, blkno);
	lock_buffer(bh);
	memset(bh->b_data, 0, bh->b_size);
	set_buffer_uptodate(bh);
	clear_buffer_dirty(bh);
	unlock_buffer(bh);

	log_incr_head(sdp);

	return bh;
}

/**
 * gfs2_log_fake_buf - Build a fake buffer head to write metadata buffer to log
 * @sdp: the filesystem
 * @data: the data the buffer_head should point to
 *
 * Returns: the log buffer descriptor
 */

struct buffer_head *gfs2_log_fake_buf(struct gfs2_sbd *sdp,
				      struct buffer_head *real)
{
	u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head);
	struct gfs2_log_buf *lb;
	struct buffer_head *bh;

	lb = kzalloc(sizeof(struct gfs2_log_buf), GFP_NOFS | __GFP_NOFAIL);
	list_add(&lb->lb_list, &sdp->sd_log_flush_list);
	lb->lb_real = real;

	bh = lb->lb_bh = alloc_buffer_head(GFP_NOFS | __GFP_NOFAIL);
	atomic_set(&bh->b_count, 1);
	bh->b_state = (1 << BH_Mapped) | (1 << BH_Uptodate);
	set_bh_page(bh, real->b_page, bh_offset(real));
	bh->b_blocknr = blkno;
	bh->b_size = sdp->sd_sb.sb_bsize;
	bh->b_bdev = sdp->sd_vfs->s_bdev;

	log_incr_head(sdp);

	return bh;
}

static void log_pull_tail(struct gfs2_sbd *sdp, unsigned int new_tail, int pull)
{
	unsigned int dist = log_distance(sdp, new_tail, sdp->sd_log_tail);

	ail2_empty(sdp, new_tail);

	gfs2_log_lock(sdp);
	sdp->sd_log_blks_free += dist - (pull ? 1 : 0);
	/* printk(KERN_INFO "pull tail refunding %u blocks (%u left) pull=%d\n", dist - (pull ? 1 : 0), sdp->sd_log_blks_free, pull); */
	gfs2_assert_withdraw(sdp,
			     sdp->sd_log_blks_free <= sdp->sd_jdesc->jd_blocks);
	gfs2_log_unlock(sdp);

	sdp->sd_log_tail = new_tail;
}

/**
 * log_write_header - Get and initialize a journal header buffer
 * @sdp: The GFS2 superblock
 *
 * Returns: the initialized log buffer descriptor
 */

static void log_write_header(struct gfs2_sbd *sdp, u32 flags, int pull)
{
	u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head);
	struct buffer_head *bh;
	struct gfs2_log_header *lh;
	unsigned int tail;
	u32 hash;

	/* printk(KERN_INFO "log write header start (flags=%08x, pull=%d)\n", flags, pull); */

	bh = sb_getblk(sdp->sd_vfs, blkno);
	lock_buffer(bh);
	memset(bh->b_data, 0, bh->b_size);
	set_buffer_uptodate(bh);
	clear_buffer_dirty(bh);
	unlock_buffer(bh);

	gfs2_ail1_empty(sdp, 0);
	tail = current_tail(sdp);

	lh = (struct gfs2_log_header *)bh->b_data;
	memset(lh, 0, sizeof(struct gfs2_log_header));
	lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
	lh->lh_header.mh_type = cpu_to_be32(GFS2_METATYPE_LH);
	lh->lh_header.mh_format = cpu_to_be32(GFS2_FORMAT_LH);
	lh->lh_sequence = cpu_to_be64(sdp->sd_log_sequence++);
	lh->lh_flags = cpu_to_be32(flags);
	lh->lh_tail = cpu_to_be32(tail);
	lh->lh_blkno = cpu_to_be32(sdp->sd_log_flush_head);
	hash = gfs2_disk_hash(bh->b_data, sizeof(struct gfs2_log_header));
	lh->lh_hash = cpu_to_be32(hash);

	set_buffer_dirty(bh);
	if (sync_dirty_buffer(bh))
		gfs2_io_error_bh(sdp, bh);
	brelse(bh);

	if (sdp->sd_log_tail != tail)
		log_pull_tail(sdp, tail, pull);
	else
		gfs2_assert_withdraw(sdp, !pull);

	sdp->sd_log_idle = (tail == sdp->sd_log_flush_head);
	log_incr_head(sdp);

	/* printk(KERN_INFO "log write header out\n"); */
}

static void log_flush_commit(struct gfs2_sbd *sdp)
{
	struct list_head *head = &sdp->sd_log_flush_list;
	struct gfs2_log_buf *lb;
	struct buffer_head *bh;

	while (!list_empty(head)) {
		lb = list_entry(head->next, struct gfs2_log_buf, lb_list);
		list_del(&lb->lb_list);
		bh = lb->lb_bh;

		wait_on_buffer(bh);
		if (!buffer_uptodate(bh))
			gfs2_io_error_bh(sdp, bh);
		if (lb->lb_real) {
			while (atomic_read(&bh->b_count) != 1)  /* Grrrr... */
				schedule();
			free_buffer_head(bh);
		} else
			brelse(bh);
		kfree(lb);
	}

	log_write_header(sdp, 0, 0);
}

/**
 * gfs2_log_flush - flush incore transaction(s)
 * @sdp: the filesystem
 * @gl: The glock structure to flush.  If NULL, flush the whole incore log
 *
 */

void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl)
{
	struct gfs2_ail *ai;

	down_write(&sdp->sd_log_flush_lock);

	if (gl) {
		gfs2_log_lock(sdp);
		if (list_empty(&gl->gl_le.le_list)) {
			gfs2_log_unlock(sdp);
			up_write(&sdp->sd_log_flush_lock);
			return;
		}
		gfs2_log_unlock(sdp);
	}

	ai = kzalloc(sizeof(struct gfs2_ail), GFP_NOFS | __GFP_NOFAIL);
	INIT_LIST_HEAD(&ai->ai_ail1_list);
	INIT_LIST_HEAD(&ai->ai_ail2_list);

	gfs2_assert_withdraw(sdp,
			sdp->sd_log_num_buf == sdp->sd_log_commited_buf);
	gfs2_assert_withdraw(sdp,
			sdp->sd_log_num_revoke == sdp->sd_log_commited_revoke);

	sdp->sd_log_flush_head = sdp->sd_log_head;
	sdp->sd_log_flush_wrapped = 0;
	ai->ai_first = sdp->sd_log_flush_head;

	lops_before_commit(sdp);
	if (!list_empty(&sdp->sd_log_flush_list))
		log_flush_commit(sdp);
	else if (sdp->sd_log_tail != current_tail(sdp) && !sdp->sd_log_idle)
		log_write_header(sdp, 0, PULL);
	lops_after_commit(sdp, ai);
	sdp->sd_log_head = sdp->sd_log_flush_head;

	/* printk(KERN_INFO "sd_log_num_hdrs %u\n", sdp->sd_log_num_hdrs); */
	sdp->sd_log_blks_free -= sdp->sd_log_num_hdrs;

	sdp->sd_log_blks_reserved =
		sdp->sd_log_commited_buf =
		sdp->sd_log_num_hdrs = 
		sdp->sd_log_commited_revoke = 0;

	gfs2_log_lock(sdp);
	if (!list_empty(&ai->ai_ail1_list)) {
		list_add(&ai->ai_list, &sdp->sd_ail1_list);
		ai = NULL;
	}
	gfs2_log_unlock(sdp);

	sdp->sd_vfs->s_dirt = 0;
	up_write(&sdp->sd_log_flush_lock);

	kfree(ai);
}

static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
{
	unsigned int reserved = 0;
	unsigned int old;

	gfs2_log_lock(sdp);

	sdp->sd_log_commited_buf += tr->tr_num_buf_new - tr->tr_num_buf_rm;
	gfs2_assert_withdraw(sdp, ((int)sdp->sd_log_commited_buf) >= 0);
	sdp->sd_log_commited_revoke += tr->tr_num_revoke - tr->tr_num_revoke_rm;
	gfs2_assert_withdraw(sdp, ((int)sdp->sd_log_commited_revoke) >= 0);

	if (sdp->sd_log_commited_buf)
		reserved += sdp->sd_log_commited_buf;
	if (sdp->sd_log_commited_revoke)
		reserved += gfs2_struct2blk(sdp, sdp->sd_log_commited_revoke,
					    sizeof(u64));
	if (reserved)
		reserved++;

	old = sdp->sd_log_blks_free;
	sdp->sd_log_blks_free += tr->tr_reserved -
				 (reserved - sdp->sd_log_blks_reserved);

	gfs2_assert_withdraw(sdp, sdp->sd_log_blks_free >= old);
	gfs2_assert_withdraw(sdp,
			     sdp->sd_log_blks_free <= sdp->sd_jdesc->jd_blocks +
			     sdp->sd_log_num_hdrs);

	sdp->sd_log_blks_reserved = reserved;

	gfs2_log_unlock(sdp);
}

/**
 * gfs2_log_commit - Commit a transaction to the log
 * @sdp: the filesystem
 * @tr: the transaction
 *
 * Returns: errno
 */

void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
{
	log_refund(sdp, tr);
	lops_incore_commit(sdp, tr);

	sdp->sd_vfs->s_dirt = 1;
	up_read(&sdp->sd_log_flush_lock);

	gfs2_log_lock(sdp);
	if (sdp->sd_log_num_buf > gfs2_tune_get(sdp, gt_incore_log_blocks)) {
		gfs2_log_unlock(sdp);
		gfs2_log_flush(sdp, NULL);
	} else
		gfs2_log_unlock(sdp);
}

/**
 * gfs2_log_shutdown - write a shutdown header into a journal
 * @sdp: the filesystem
 *
 */

void gfs2_log_shutdown(struct gfs2_sbd *sdp)
{
	down_write(&sdp->sd_log_flush_lock);

	gfs2_assert_withdraw(sdp, !sdp->sd_log_blks_reserved);
	gfs2_assert_withdraw(sdp, !sdp->sd_log_num_gl);
	gfs2_assert_withdraw(sdp, !sdp->sd_log_num_buf);
	gfs2_assert_withdraw(sdp, !sdp->sd_log_num_jdata);
	gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke);
	gfs2_assert_withdraw(sdp, !sdp->sd_log_num_rg);
	gfs2_assert_withdraw(sdp, !sdp->sd_log_num_databuf);
	gfs2_assert_withdraw(sdp, !sdp->sd_log_num_hdrs);
	gfs2_assert_withdraw(sdp, list_empty(&sdp->sd_ail1_list));

	sdp->sd_log_flush_head = sdp->sd_log_head;
	sdp->sd_log_flush_wrapped = 0;

	log_write_header(sdp, GFS2_LOG_HEAD_UNMOUNT, 0);

	/* printk(KERN_INFO "sd_log_blks_free %u, sd_jdesc->jd_blocks %u\n", sdp->sd_log_blks_free, sdp->sd_jdesc->jd_blocks); */
	gfs2_assert_warn(sdp, sdp->sd_log_blks_free == sdp->sd_jdesc->jd_blocks);
	gfs2_assert_warn(sdp, sdp->sd_log_head == sdp->sd_log_tail);
	gfs2_assert_warn(sdp, list_empty(&sdp->sd_ail2_list));

	sdp->sd_log_head = sdp->sd_log_flush_head;
	sdp->sd_log_tail = sdp->sd_log_head;

	up_write(&sdp->sd_log_flush_lock);
}