summaryrefslogtreecommitdiff
path: root/fs/ocfs2/quota_global.c
blob: bf7742d0ee3bba05a7ceabab948aff62f27482f0 (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
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
/*
 *  Implementation of operations over global quota file
 */
#include <linux/spinlock.h>
#include <linux/fs.h>
#include <linux/quota.h>
#include <linux/quotaops.h>
#include <linux/dqblk_qtree.h>
#include <linux/jiffies.h>
#include <linux/writeback.h>
#include <linux/workqueue.h>

#define MLOG_MASK_PREFIX ML_QUOTA
#include <cluster/masklog.h>

#include "ocfs2_fs.h"
#include "ocfs2.h"
#include "alloc.h"
#include "blockcheck.h"
#include "inode.h"
#include "journal.h"
#include "file.h"
#include "sysfile.h"
#include "dlmglue.h"
#include "uptodate.h"
#include "quota.h"

static struct workqueue_struct *ocfs2_quota_wq = NULL;

static void qsync_work_fn(struct work_struct *work);

static void ocfs2_global_disk2memdqb(struct dquot *dquot, void *dp)
{
	struct ocfs2_global_disk_dqblk *d = dp;
	struct mem_dqblk *m = &dquot->dq_dqb;

	/* Update from disk only entries not set by the admin */
	if (!test_bit(DQ_LASTSET_B + QIF_ILIMITS_B, &dquot->dq_flags)) {
		m->dqb_ihardlimit = le64_to_cpu(d->dqb_ihardlimit);
		m->dqb_isoftlimit = le64_to_cpu(d->dqb_isoftlimit);
	}
	if (!test_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags))
		m->dqb_curinodes = le64_to_cpu(d->dqb_curinodes);
	if (!test_bit(DQ_LASTSET_B + QIF_BLIMITS_B, &dquot->dq_flags)) {
		m->dqb_bhardlimit = le64_to_cpu(d->dqb_bhardlimit);
		m->dqb_bsoftlimit = le64_to_cpu(d->dqb_bsoftlimit);
	}
	if (!test_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags))
		m->dqb_curspace = le64_to_cpu(d->dqb_curspace);
	if (!test_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags))
		m->dqb_btime = le64_to_cpu(d->dqb_btime);
	if (!test_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags))
		m->dqb_itime = le64_to_cpu(d->dqb_itime);
	OCFS2_DQUOT(dquot)->dq_use_count = le32_to_cpu(d->dqb_use_count);
}

static void ocfs2_global_mem2diskdqb(void *dp, struct dquot *dquot)
{
	struct ocfs2_global_disk_dqblk *d = dp;
	struct mem_dqblk *m = &dquot->dq_dqb;

	d->dqb_id = cpu_to_le32(dquot->dq_id);
	d->dqb_use_count = cpu_to_le32(OCFS2_DQUOT(dquot)->dq_use_count);
	d->dqb_ihardlimit = cpu_to_le64(m->dqb_ihardlimit);
	d->dqb_isoftlimit = cpu_to_le64(m->dqb_isoftlimit);
	d->dqb_curinodes = cpu_to_le64(m->dqb_curinodes);
	d->dqb_bhardlimit = cpu_to_le64(m->dqb_bhardlimit);
	d->dqb_bsoftlimit = cpu_to_le64(m->dqb_bsoftlimit);
	d->dqb_curspace = cpu_to_le64(m->dqb_curspace);
	d->dqb_btime = cpu_to_le64(m->dqb_btime);
	d->dqb_itime = cpu_to_le64(m->dqb_itime);
	d->dqb_pad1 = d->dqb_pad2 = 0;
}

static int ocfs2_global_is_id(void *dp, struct dquot *dquot)
{
	struct ocfs2_global_disk_dqblk *d = dp;
	struct ocfs2_mem_dqinfo *oinfo =
			sb_dqinfo(dquot->dq_sb, dquot->dq_type)->dqi_priv;

	if (qtree_entry_unused(&oinfo->dqi_gi, dp))
		return 0;
	return le32_to_cpu(d->dqb_id) == dquot->dq_id;
}

struct qtree_fmt_operations ocfs2_global_ops = {
	.mem2disk_dqblk = ocfs2_global_mem2diskdqb,
	.disk2mem_dqblk = ocfs2_global_disk2memdqb,
	.is_id = ocfs2_global_is_id,
};

static int ocfs2_validate_quota_block(struct super_block *sb,
				      struct buffer_head *bh)
{
	struct ocfs2_disk_dqtrailer *dqt =
		ocfs2_block_dqtrailer(sb->s_blocksize, bh->b_data);

	mlog(0, "Validating quota block %llu\n",
	     (unsigned long long)bh->b_blocknr);

	BUG_ON(!buffer_uptodate(bh));

	/*
	 * If the ecc fails, we return the error but otherwise
	 * leave the filesystem running.  We know any error is
	 * local to this block.
	 */
	return ocfs2_validate_meta_ecc(sb, bh->b_data, &dqt->dq_check);
}

int ocfs2_read_quota_block(struct inode *inode, u64 v_block,
			   struct buffer_head **bh)
{
	int rc = 0;
	struct buffer_head *tmp = *bh;

	rc = ocfs2_read_virt_blocks(inode, v_block, 1, &tmp, 0,
				    ocfs2_validate_quota_block);
	if (rc)
		mlog_errno(rc);

	/* If ocfs2_read_virt_blocks() got us a new bh, pass it up. */
	if (!rc && !*bh)
		*bh = tmp;

	return rc;
}

static int ocfs2_get_quota_block(struct inode *inode, int block,
				 struct buffer_head **bh)
{
	u64 pblock, pcount;
	int err;

	down_read(&OCFS2_I(inode)->ip_alloc_sem);
	err = ocfs2_extent_map_get_blocks(inode, block, &pblock, &pcount, NULL);
	up_read(&OCFS2_I(inode)->ip_alloc_sem);
	if (err) {
		mlog_errno(err);
		return err;
	}
	*bh = sb_getblk(inode->i_sb, pblock);
	if (!*bh) {
		err = -EIO;
		mlog_errno(err);
	}
	return err;;
}

/* Read data from global quotafile - avoid pagecache and such because we cannot
 * afford acquiring the locks... We use quota cluster lock to serialize
 * operations. Caller is responsible for acquiring it. */
ssize_t ocfs2_quota_read(struct super_block *sb, int type, char *data,
			 size_t len, loff_t off)
{
	struct ocfs2_mem_dqinfo *oinfo = sb_dqinfo(sb, type)->dqi_priv;
	struct inode *gqinode = oinfo->dqi_gqinode;
	loff_t i_size = i_size_read(gqinode);
	int offset = off & (sb->s_blocksize - 1);
	sector_t blk = off >> sb->s_blocksize_bits;
	int err = 0;
	struct buffer_head *bh;
	size_t toread, tocopy;

	if (off > i_size)
		return 0;
	if (off + len > i_size)
		len = i_size - off;
	toread = len;
	while (toread > 0) {
		tocopy = min_t(size_t, (sb->s_blocksize - offset), toread);
		bh = NULL;
		err = ocfs2_read_quota_block(gqinode, blk, &bh);
		if (err) {
			mlog_errno(err);
			return err;
		}
		memcpy(data, bh->b_data + offset, tocopy);
		brelse(bh);
		offset = 0;
		toread -= tocopy;
		data += tocopy;
		blk++;
	}
	return len;
}

/* Write to quotafile (we know the transaction is already started and has
 * enough credits) */
ssize_t ocfs2_quota_write(struct super_block *sb, int type,
			  const char *data, size_t len, loff_t off)
{
	struct mem_dqinfo *info = sb_dqinfo(sb, type);
	struct ocfs2_mem_dqinfo *oinfo = info->dqi_priv;
	struct inode *gqinode = oinfo->dqi_gqinode;
	int offset = off & (sb->s_blocksize - 1);
	sector_t blk = off >> sb->s_blocksize_bits;
	int err = 0, new = 0, ja_type;
	struct buffer_head *bh = NULL;
	handle_t *handle = journal_current_handle();

	if (!handle) {
		mlog(ML_ERROR, "Quota write (off=%llu, len=%llu) cancelled "
		     "because transaction was not started.\n",
		     (unsigned long long)off, (unsigned long long)len);
		return -EIO;
	}
	if (len > sb->s_blocksize - OCFS2_QBLK_RESERVED_SPACE - offset) {
		WARN_ON(1);
		len = sb->s_blocksize - OCFS2_QBLK_RESERVED_SPACE - offset;
	}

	mutex_lock_nested(&gqinode->i_mutex, I_MUTEX_QUOTA);
	if (gqinode->i_size < off + len) {
		loff_t rounded_end =
				ocfs2_align_bytes_to_blocks(sb, off + len);

		/* Space is already allocated in ocfs2_global_read_dquot() */
		err = ocfs2_simple_size_update(gqinode,
					       oinfo->dqi_gqi_bh,
					       rounded_end);
		if (err < 0)
			goto out;
		new = 1;
	}
	/* Not rewriting whole block? */
	if ((offset || len < sb->s_blocksize - OCFS2_QBLK_RESERVED_SPACE) &&
	    !new) {
		err = ocfs2_read_quota_block(gqinode, blk, &bh);
		ja_type = OCFS2_JOURNAL_ACCESS_WRITE;
	} else {
		err = ocfs2_get_quota_block(gqinode, blk, &bh);
		ja_type = OCFS2_JOURNAL_ACCESS_CREATE;
	}
	if (err) {
		mlog_errno(err);
		goto out;
	}
	lock_buffer(bh);
	if (new)
		memset(bh->b_data, 0, sb->s_blocksize);
	memcpy(bh->b_data + offset, data, len);
	flush_dcache_page(bh->b_page);
	set_buffer_uptodate(bh);
	unlock_buffer(bh);
	ocfs2_set_buffer_uptodate(gqinode, bh);
	err = ocfs2_journal_access_dq(handle, gqinode, bh, ja_type);
	if (err < 0) {
		brelse(bh);
		goto out;
	}
	err = ocfs2_journal_dirty(handle, bh);
	brelse(bh);
	if (err < 0)
		goto out;
out:
	if (err) {
		mutex_unlock(&gqinode->i_mutex);
		mlog_errno(err);
		return err;
	}
	gqinode->i_version++;
	ocfs2_mark_inode_dirty(handle, gqinode, oinfo->dqi_gqi_bh);
	mutex_unlock(&gqinode->i_mutex);
	return len;
}

int ocfs2_lock_global_qf(struct ocfs2_mem_dqinfo *oinfo, int ex)
{
	int status;
	struct buffer_head *bh = NULL;

	status = ocfs2_inode_lock(oinfo->dqi_gqinode, &bh, ex);
	if (status < 0)
		return status;
	spin_lock(&dq_data_lock);
	if (!oinfo->dqi_gqi_count++)
		oinfo->dqi_gqi_bh = bh;
	else
		WARN_ON(bh != oinfo->dqi_gqi_bh);
	spin_unlock(&dq_data_lock);
	return 0;
}

void ocfs2_unlock_global_qf(struct ocfs2_mem_dqinfo *oinfo, int ex)
{
	ocfs2_inode_unlock(oinfo->dqi_gqinode, ex);
	brelse(oinfo->dqi_gqi_bh);
	spin_lock(&dq_data_lock);
	if (!--oinfo->dqi_gqi_count)
		oinfo->dqi_gqi_bh = NULL;
	spin_unlock(&dq_data_lock);
}

/* Read information header from global quota file */
int ocfs2_global_read_info(struct super_block *sb, int type)
{
	struct inode *gqinode = NULL;
	unsigned int ino[MAXQUOTAS] = { USER_QUOTA_SYSTEM_INODE,
					GROUP_QUOTA_SYSTEM_INODE };
	struct ocfs2_global_disk_dqinfo dinfo;
	struct mem_dqinfo *info = sb_dqinfo(sb, type);
	struct ocfs2_mem_dqinfo *oinfo = info->dqi_priv;
	int status;

	mlog_entry_void();

	/* Read global header */
	gqinode = ocfs2_get_system_file_inode(OCFS2_SB(sb), ino[type],
			OCFS2_INVALID_SLOT);
	if (!gqinode) {
		mlog(ML_ERROR, "failed to get global quota inode (type=%d)\n",
			type);
		status = -EINVAL;
		goto out_err;
	}
	oinfo->dqi_gi.dqi_sb = sb;
	oinfo->dqi_gi.dqi_type = type;
	ocfs2_qinfo_lock_res_init(&oinfo->dqi_gqlock, oinfo);
	oinfo->dqi_gi.dqi_entry_size = sizeof(struct ocfs2_global_disk_dqblk);
	oinfo->dqi_gi.dqi_ops = &ocfs2_global_ops;
	oinfo->dqi_gqi_bh = NULL;
	oinfo->dqi_gqi_count = 0;
	oinfo->dqi_gqinode = gqinode;
	status = ocfs2_lock_global_qf(oinfo, 0);
	if (status < 0) {
		mlog_errno(status);
		goto out_err;
	}
	status = sb->s_op->quota_read(sb, type, (char *)&dinfo,
				      sizeof(struct ocfs2_global_disk_dqinfo),
				      OCFS2_GLOBAL_INFO_OFF);
	ocfs2_unlock_global_qf(oinfo, 0);
	if (status != sizeof(struct ocfs2_global_disk_dqinfo)) {
		mlog(ML_ERROR, "Cannot read global quota info (%d).\n",
		     status);
		if (status >= 0)
			status = -EIO;
		mlog_errno(status);
		goto out_err;
	}
	info->dqi_bgrace = le32_to_cpu(dinfo.dqi_bgrace);
	info->dqi_igrace = le32_to_cpu(dinfo.dqi_igrace);
	oinfo->dqi_syncms = le32_to_cpu(dinfo.dqi_syncms);
	oinfo->dqi_gi.dqi_blocks = le32_to_cpu(dinfo.dqi_blocks);
	oinfo->dqi_gi.dqi_free_blk = le32_to_cpu(dinfo.dqi_free_blk);
	oinfo->dqi_gi.dqi_free_entry = le32_to_cpu(dinfo.dqi_free_entry);
	oinfo->dqi_gi.dqi_blocksize_bits = sb->s_blocksize_bits;
	oinfo->dqi_gi.dqi_usable_bs = sb->s_blocksize -
						OCFS2_QBLK_RESERVED_SPACE;
	oinfo->dqi_gi.dqi_qtree_depth = qtree_depth(&oinfo->dqi_gi);
	INIT_DELAYED_WORK(&oinfo->dqi_sync_work, qsync_work_fn);
	queue_delayed_work(ocfs2_quota_wq, &oinfo->dqi_sync_work,
			   msecs_to_jiffies(oinfo->dqi_syncms));

out_err:
	mlog_exit(status);
	return status;
}

/* Write information to global quota file. Expects exlusive lock on quota
 * file inode and quota info */
static int __ocfs2_global_write_info(struct super_block *sb, int type)
{
	struct mem_dqinfo *info = sb_dqinfo(sb, type);
	struct ocfs2_mem_dqinfo *oinfo = info->dqi_priv;
	struct ocfs2_global_disk_dqinfo dinfo;
	ssize_t size;

	spin_lock(&dq_data_lock);
	info->dqi_flags &= ~DQF_INFO_DIRTY;
	dinfo.dqi_bgrace = cpu_to_le32(info->dqi_bgrace);
	dinfo.dqi_igrace = cpu_to_le32(info->dqi_igrace);
	spin_unlock(&dq_data_lock);
	dinfo.dqi_syncms = cpu_to_le32(oinfo->dqi_syncms);
	dinfo.dqi_blocks = cpu_to_le32(oinfo->dqi_gi.dqi_blocks);
	dinfo.dqi_free_blk = cpu_to_le32(oinfo->dqi_gi.dqi_free_blk);
	dinfo.dqi_free_entry = cpu_to_le32(oinfo->dqi_gi.dqi_free_entry);
	size = sb->s_op->quota_write(sb, type, (char *)&dinfo,
				     sizeof(struct ocfs2_global_disk_dqinfo),
				     OCFS2_GLOBAL_INFO_OFF);
	if (size != sizeof(struct ocfs2_global_disk_dqinfo)) {
		mlog(ML_ERROR, "Cannot write global quota info structure\n");
		if (size >= 0)
			size = -EIO;
		return size;
	}
	return 0;
}

int ocfs2_global_write_info(struct super_block *sb, int type)
{
	int err;
	struct ocfs2_mem_dqinfo *info = sb_dqinfo(sb, type)->dqi_priv;

	err = ocfs2_qinfo_lock(info, 1);
	if (err < 0)
		return err;
	err = __ocfs2_global_write_info(sb, type);
	ocfs2_qinfo_unlock(info, 1);
	return err;
}

static int ocfs2_global_qinit_alloc(struct super_block *sb, int type)
{
	struct ocfs2_mem_dqinfo *oinfo = sb_dqinfo(sb, type)->dqi_priv;

	/*
	 * We may need to allocate tree blocks and a leaf block but not the
	 * root block
	 */
	return oinfo->dqi_gi.dqi_qtree_depth;
}

static int ocfs2_calc_global_qinit_credits(struct super_block *sb, int type)
{
	/* We modify all the allocated blocks, tree root, and info block */
	return (ocfs2_global_qinit_alloc(sb, type) + 2) *
			OCFS2_QUOTA_BLOCK_UPDATE_CREDITS;
}

/* Read in information from global quota file and acquire a reference to it.
 * dquot_acquire() has already started the transaction and locked quota file */
int ocfs2_global_read_dquot(struct dquot *dquot)
{
	int err, err2, ex = 0;
	struct super_block *sb = dquot->dq_sb;
	int type = dquot->dq_type;
	struct ocfs2_mem_dqinfo *info = sb_dqinfo(sb, type)->dqi_priv;
	struct ocfs2_super *osb = OCFS2_SB(sb);
	struct inode *gqinode = info->dqi_gqinode;
	int need_alloc = ocfs2_global_qinit_alloc(sb, type);
	handle_t *handle = NULL;

	err = ocfs2_qinfo_lock(info, 0);
	if (err < 0)
		goto out;
	err = qtree_read_dquot(&info->dqi_gi, dquot);
	if (err < 0)
		goto out_qlock;
	OCFS2_DQUOT(dquot)->dq_use_count++;
	OCFS2_DQUOT(dquot)->dq_origspace = dquot->dq_dqb.dqb_curspace;
	OCFS2_DQUOT(dquot)->dq_originodes = dquot->dq_dqb.dqb_curinodes;
	ocfs2_qinfo_unlock(info, 0);

	if (!dquot->dq_off) {	/* No real quota entry? */
		ex = 1;
		/*
		 * Add blocks to quota file before we start a transaction since
		 * locking allocators ranks above a transaction start
		 */
		WARN_ON(journal_current_handle());
		down_write(&OCFS2_I(gqinode)->ip_alloc_sem);
		err = ocfs2_extend_no_holes(gqinode,
			gqinode->i_size + (need_alloc << sb->s_blocksize_bits),
			gqinode->i_size);
		up_write(&OCFS2_I(gqinode)->ip_alloc_sem);
		if (err < 0)
			goto out;
	}

	handle = ocfs2_start_trans(osb,
				   ocfs2_calc_global_qinit_credits(sb, type));
	if (IS_ERR(handle)) {
		err = PTR_ERR(handle);
		goto out;
	}
	err = ocfs2_qinfo_lock(info, ex);
	if (err < 0)
		goto out_trans;
	err = qtree_write_dquot(&info->dqi_gi, dquot);
	if (ex && info_dirty(sb_dqinfo(dquot->dq_sb, dquot->dq_type))) {
		err2 = __ocfs2_global_write_info(dquot->dq_sb, dquot->dq_type);
		if (!err)
			err = err2;
	}
out_qlock:
	if (ex)
		ocfs2_qinfo_unlock(info, 1);
	else
		ocfs2_qinfo_unlock(info, 0);
out_trans:
	if (handle)
		ocfs2_commit_trans(osb, handle);
out:
	if (err < 0)
		mlog_errno(err);
	return err;
}

/* Sync local information about quota modifications with global quota file.
 * Caller must have started the transaction and obtained exclusive lock for
 * global quota file inode */
int __ocfs2_sync_dquot(struct dquot *dquot, int freeing)
{
	int err, err2;
	struct super_block *sb = dquot->dq_sb;
	int type = dquot->dq_type;
	struct ocfs2_mem_dqinfo *info = sb_dqinfo(sb, type)->dqi_priv;
	struct ocfs2_global_disk_dqblk dqblk;
	s64 spacechange, inodechange;
	time_t olditime, oldbtime;

	err = sb->s_op->quota_read(sb, type, (char *)&dqblk,
				   sizeof(struct ocfs2_global_disk_dqblk),
				   dquot->dq_off);
	if (err != sizeof(struct ocfs2_global_disk_dqblk)) {
		if (err >= 0) {
			mlog(ML_ERROR, "Short read from global quota file "
				       "(%u read)\n", err);
			err = -EIO;
		}
		goto out;
	}

	/* Update space and inode usage. Get also other information from
	 * global quota file so that we don't overwrite any changes there.
	 * We are */
	spin_lock(&dq_data_lock);
	spacechange = dquot->dq_dqb.dqb_curspace -
					OCFS2_DQUOT(dquot)->dq_origspace;
	inodechange = dquot->dq_dqb.dqb_curinodes -
					OCFS2_DQUOT(dquot)->dq_originodes;
	olditime = dquot->dq_dqb.dqb_itime;
	oldbtime = dquot->dq_dqb.dqb_btime;
	ocfs2_global_disk2memdqb(dquot, &dqblk);
	mlog(0, "Syncing global dquot %u space %lld+%lld, inodes %lld+%lld\n",
	     dquot->dq_id, dquot->dq_dqb.dqb_curspace, (long long)spacechange,
	     dquot->dq_dqb.dqb_curinodes, (long long)inodechange);
	if (!test_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags))
		dquot->dq_dqb.dqb_curspace += spacechange;
	if (!test_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags))
		dquot->dq_dqb.dqb_curinodes += inodechange;
	/* Set properly space grace time... */
	if (dquot->dq_dqb.dqb_bsoftlimit &&
	    dquot->dq_dqb.dqb_curspace > dquot->dq_dqb.dqb_bsoftlimit) {
		if (!test_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags) &&
		    oldbtime > 0) {
			if (dquot->dq_dqb.dqb_btime > 0)
				dquot->dq_dqb.dqb_btime =
					min(dquot->dq_dqb.dqb_btime, oldbtime);
			else
				dquot->dq_dqb.dqb_btime = oldbtime;
		}
	} else {
		dquot->dq_dqb.dqb_btime = 0;
		clear_bit(DQ_BLKS_B, &dquot->dq_flags);
	}
	/* Set properly inode grace time... */
	if (dquot->dq_dqb.dqb_isoftlimit &&
	    dquot->dq_dqb.dqb_curinodes > dquot->dq_dqb.dqb_isoftlimit) {
		if (!test_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags) &&
		    olditime > 0) {
			if (dquot->dq_dqb.dqb_itime > 0)
				dquot->dq_dqb.dqb_itime =
					min(dquot->dq_dqb.dqb_itime, olditime);
			else
				dquot->dq_dqb.dqb_itime = olditime;
		}
	} else {
		dquot->dq_dqb.dqb_itime = 0;
		clear_bit(DQ_INODES_B, &dquot->dq_flags);
	}
	/* All information is properly updated, clear the flags */
	__clear_bit(DQ_LASTSET_B + QIF_SPACE_B, &dquot->dq_flags);
	__clear_bit(DQ_LASTSET_B + QIF_INODES_B, &dquot->dq_flags);
	__clear_bit(DQ_LASTSET_B + QIF_BLIMITS_B, &dquot->dq_flags);
	__clear_bit(DQ_LASTSET_B + QIF_ILIMITS_B, &dquot->dq_flags);
	__clear_bit(DQ_LASTSET_B + QIF_BTIME_B, &dquot->dq_flags);
	__clear_bit(DQ_LASTSET_B + QIF_ITIME_B, &dquot->dq_flags);
	OCFS2_DQUOT(dquot)->dq_origspace = dquot->dq_dqb.dqb_curspace;
	OCFS2_DQUOT(dquot)->dq_originodes = dquot->dq_dqb.dqb_curinodes;
	spin_unlock(&dq_data_lock);
	err = ocfs2_qinfo_lock(info, freeing);
	if (err < 0) {
		mlog(ML_ERROR, "Failed to lock quota info, loosing quota write"
			       " (type=%d, id=%u)\n", dquot->dq_type,
			       (unsigned)dquot->dq_id);
		goto out;
	}
	if (freeing)
		OCFS2_DQUOT(dquot)->dq_use_count--;
	err = qtree_write_dquot(&info->dqi_gi, dquot);
	if (err < 0)
		goto out_qlock;
	if (freeing && !OCFS2_DQUOT(dquot)->dq_use_count) {
		err = qtree_release_dquot(&info->dqi_gi, dquot);
		if (info_dirty(sb_dqinfo(sb, type))) {
			err2 = __ocfs2_global_write_info(sb, type);
			if (!err)
				err = err2;
		}
	}
out_qlock:
	ocfs2_qinfo_unlock(info, freeing);
out:
	if (err < 0)
		mlog_errno(err);
	return err;
}

/*
 *  Functions for periodic syncing of dquots with global file
 */
static int ocfs2_sync_dquot_helper(struct dquot *dquot, unsigned long type)
{
	handle_t *handle;
	struct super_block *sb = dquot->dq_sb;
	struct ocfs2_mem_dqinfo *oinfo = sb_dqinfo(sb, type)->dqi_priv;
	struct ocfs2_super *osb = OCFS2_SB(sb);
	int status = 0;

	mlog_entry("id=%u qtype=%u type=%lu device=%s\n", dquot->dq_id,
		   dquot->dq_type, type, sb->s_id);
	if (type != dquot->dq_type)
		goto out;
	status = ocfs2_lock_global_qf(oinfo, 1);
	if (status < 0)
		goto out;

	handle = ocfs2_start_trans(osb, OCFS2_QSYNC_CREDITS);
	if (IS_ERR(handle)) {
		status = PTR_ERR(handle);
		mlog_errno(status);
		goto out_ilock;
	}
	mutex_lock(&sb_dqopt(sb)->dqio_mutex);
	status = ocfs2_sync_dquot(dquot);
	mutex_unlock(&sb_dqopt(sb)->dqio_mutex);
	if (status < 0)
		mlog_errno(status);
	/* We have to write local structure as well... */
	dquot_mark_dquot_dirty(dquot);
	status = dquot_commit(dquot);
	if (status < 0)
		mlog_errno(status);
	ocfs2_commit_trans(osb, handle);
out_ilock:
	ocfs2_unlock_global_qf(oinfo, 1);
out:
	mlog_exit(status);
	return status;
}

static void qsync_work_fn(struct work_struct *work)
{
	struct ocfs2_mem_dqinfo *oinfo = container_of(work,
						      struct ocfs2_mem_dqinfo,
						      dqi_sync_work.work);
	struct super_block *sb = oinfo->dqi_gqinode->i_sb;

	dquot_scan_active(sb, ocfs2_sync_dquot_helper, oinfo->dqi_type);
	queue_delayed_work(ocfs2_quota_wq, &oinfo->dqi_sync_work,
			   msecs_to_jiffies(oinfo->dqi_syncms));
}

/*
 *  Wrappers for generic quota functions
 */

static int ocfs2_write_dquot(struct dquot *dquot)
{
	handle_t *handle;
	struct ocfs2_super *osb = OCFS2_SB(dquot->dq_sb);
	int status = 0;

	mlog_entry("id=%u, type=%d", dquot->dq_id, dquot->dq_type);

	handle = ocfs2_start_trans(osb, OCFS2_QWRITE_CREDITS);
	if (IS_ERR(handle)) {
		status = PTR_ERR(handle);
		mlog_errno(status);
		goto out;
	}
	status = dquot_commit(dquot);
	ocfs2_commit_trans(osb, handle);
out:
	mlog_exit(status);
	return status;
}

static int ocfs2_calc_qdel_credits(struct super_block *sb, int type)
{
	struct ocfs2_mem_dqinfo *oinfo = sb_dqinfo(sb, type)->dqi_priv;
	/*
	 * We modify tree, leaf block, global info, local chunk header,
	 * global and local inode; OCFS2_QINFO_WRITE_CREDITS already
	 * accounts for inode update
	 */
	return (oinfo->dqi_gi.dqi_qtree_depth + 2) *
	       OCFS2_QUOTA_BLOCK_UPDATE_CREDITS +
	       OCFS2_QINFO_WRITE_CREDITS +
	       OCFS2_INODE_UPDATE_CREDITS;
}

static int ocfs2_release_dquot(struct dquot *dquot)
{
	handle_t *handle;
	struct ocfs2_mem_dqinfo *oinfo =
			sb_dqinfo(dquot->dq_sb, dquot->dq_type)->dqi_priv;
	struct ocfs2_super *osb = OCFS2_SB(dquot->dq_sb);
	int status = 0;

	mlog_entry("id=%u, type=%d", dquot->dq_id, dquot->dq_type);

	status = ocfs2_lock_global_qf(oinfo, 1);
	if (status < 0)
		goto out;
	handle = ocfs2_start_trans(osb,
		ocfs2_calc_qdel_credits(dquot->dq_sb, dquot->dq_type));
	if (IS_ERR(handle)) {
		status = PTR_ERR(handle);
		mlog_errno(status);
		goto out_ilock;
	}
	status = dquot_release(dquot);
	ocfs2_commit_trans(osb, handle);
out_ilock:
	ocfs2_unlock_global_qf(oinfo, 1);
out:
	mlog_exit(status);
	return status;
}

static int ocfs2_acquire_dquot(struct dquot *dquot)
{
	struct ocfs2_mem_dqinfo *oinfo =
			sb_dqinfo(dquot->dq_sb, dquot->dq_type)->dqi_priv;
	int status = 0;

	mlog_entry("id=%u, type=%d", dquot->dq_id, dquot->dq_type);
	/* We need an exclusive lock, because we're going to update use count
	 * and instantiate possibly new dquot structure */
	status = ocfs2_lock_global_qf(oinfo, 1);
	if (status < 0)
		goto out;
	status = dquot_acquire(dquot);
	ocfs2_unlock_global_qf(oinfo, 1);
out:
	mlog_exit(status);
	return status;
}

static int ocfs2_mark_dquot_dirty(struct dquot *dquot)
{
	unsigned long mask = (1 << (DQ_LASTSET_B + QIF_ILIMITS_B)) |
			     (1 << (DQ_LASTSET_B + QIF_BLIMITS_B)) |
			     (1 << (DQ_LASTSET_B + QIF_INODES_B)) |
			     (1 << (DQ_LASTSET_B + QIF_SPACE_B)) |
			     (1 << (DQ_LASTSET_B + QIF_BTIME_B)) |
			     (1 << (DQ_LASTSET_B + QIF_ITIME_B));
	int sync = 0;
	int status;
	struct super_block *sb = dquot->dq_sb;
	int type = dquot->dq_type;
	struct ocfs2_mem_dqinfo *oinfo = sb_dqinfo(sb, type)->dqi_priv;
	handle_t *handle;
	struct ocfs2_super *osb = OCFS2_SB(sb);

	mlog_entry("id=%u, type=%d", dquot->dq_id, type);
	dquot_mark_dquot_dirty(dquot);

	/* In case user set some limits, sync dquot immediately to global
	 * quota file so that information propagates quicker */
	spin_lock(&dq_data_lock);
	if (dquot->dq_flags & mask)
		sync = 1;
	spin_unlock(&dq_data_lock);
	/* This is a slight hack but we can't afford getting global quota
	 * lock if we already have a transaction started. */
	if (!sync || journal_current_handle()) {
		status = ocfs2_write_dquot(dquot);
		goto out;
	}
	status = ocfs2_lock_global_qf(oinfo, 1);
	if (status < 0)
		goto out;
	handle = ocfs2_start_trans(osb, OCFS2_QSYNC_CREDITS);
	if (IS_ERR(handle)) {
		status = PTR_ERR(handle);
		mlog_errno(status);
		goto out_ilock;
	}
	status = ocfs2_sync_dquot(dquot);
	if (status < 0) {
		mlog_errno(status);
		goto out_trans;
	}
	/* Now write updated local dquot structure */
	status = dquot_commit(dquot);
out_trans:
	ocfs2_commit_trans(osb, handle);
out_ilock:
	ocfs2_unlock_global_qf(oinfo, 1);
out:
	mlog_exit(status);
	return status;
}

/* This should happen only after set_dqinfo(). */
static int ocfs2_write_info(struct super_block *sb, int type)
{
	handle_t *handle;
	int status = 0;
	struct ocfs2_mem_dqinfo *oinfo = sb_dqinfo(sb, type)->dqi_priv;

	mlog_entry_void();

	status = ocfs2_lock_global_qf(oinfo, 1);
	if (status < 0)
		goto out;
	handle = ocfs2_start_trans(OCFS2_SB(sb), OCFS2_QINFO_WRITE_CREDITS);
	if (IS_ERR(handle)) {
		status = PTR_ERR(handle);
		mlog_errno(status);
		goto out_ilock;
	}
	status = dquot_commit_info(sb, type);
	ocfs2_commit_trans(OCFS2_SB(sb), handle);
out_ilock:
	ocfs2_unlock_global_qf(oinfo, 1);
out:
	mlog_exit(status);
	return status;
}

static struct dquot *ocfs2_alloc_dquot(struct super_block *sb, int type)
{
	struct ocfs2_dquot *dquot =
				kmem_cache_zalloc(ocfs2_dquot_cachep, GFP_NOFS);

	if (!dquot)
		return NULL;
	return &dquot->dq_dquot;
}

static void ocfs2_destroy_dquot(struct dquot *dquot)
{
	kmem_cache_free(ocfs2_dquot_cachep, dquot);
}

struct dquot_operations ocfs2_quota_operations = {
	.initialize	= dquot_initialize,
	.drop		= dquot_drop,
	.alloc_space	= dquot_alloc_space,
	.alloc_inode	= dquot_alloc_inode,
	.free_space	= dquot_free_space,
	.free_inode	= dquot_free_inode,
	.transfer	= dquot_transfer,
	.write_dquot	= ocfs2_write_dquot,
	.acquire_dquot	= ocfs2_acquire_dquot,
	.release_dquot	= ocfs2_release_dquot,
	.mark_dirty	= ocfs2_mark_dquot_dirty,
	.write_info	= ocfs2_write_info,
	.alloc_dquot	= ocfs2_alloc_dquot,
	.destroy_dquot	= ocfs2_destroy_dquot,
};

int ocfs2_quota_setup(void)
{
	ocfs2_quota_wq = create_workqueue("o2quot");
	if (!ocfs2_quota_wq)
		return -ENOMEM;
	return 0;
}

void ocfs2_quota_shutdown(void)
{
	if (ocfs2_quota_wq) {
		flush_workqueue(ocfs2_quota_wq);
		destroy_workqueue(ocfs2_quota_wq);
		ocfs2_quota_wq = NULL;
	}
}