summaryrefslogtreecommitdiff
path: root/fs/ocfs2/quota_local.c
blob: 55c3f2f98dcd706c8efde0570f93c88af2fd5539 (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
/*
 *  Implementation of operations over local quota file
 */

#include <linux/fs.h>
#include <linux/quota.h>
#include <linux/quotaops.h>
#include <linux/module.h>

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

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

/* Number of local quota structures per block */
static inline unsigned int ol_quota_entries_per_block(struct super_block *sb)
{
	return ((sb->s_blocksize - OCFS2_QBLK_RESERVED_SPACE) /
		sizeof(struct ocfs2_local_disk_dqblk));
}

/* Number of blocks with entries in one chunk */
static inline unsigned int ol_chunk_blocks(struct super_block *sb)
{
	return ((sb->s_blocksize - sizeof(struct ocfs2_local_disk_chunk) -
		 OCFS2_QBLK_RESERVED_SPACE) << 3) /
	       ol_quota_entries_per_block(sb);
}

/* Number of entries in a chunk bitmap */
static unsigned int ol_chunk_entries(struct super_block *sb)
{
	return ol_chunk_blocks(sb) * ol_quota_entries_per_block(sb);
}

/* Offset of the chunk in quota file */
static unsigned int ol_quota_chunk_block(struct super_block *sb, int c)
{
	/* 1 block for local quota file info, 1 block per chunk for chunk info */
	return 1 + (ol_chunk_blocks(sb) + 1) * c;
}

/* Offset of the dquot structure in the quota file */
static loff_t ol_dqblk_off(struct super_block *sb, int c, int off)
{
	int epb = ol_quota_entries_per_block(sb);

	return ((ol_quota_chunk_block(sb, c) + 1 + off / epb)
		<< sb->s_blocksize_bits) +
		(off % epb) * sizeof(struct ocfs2_local_disk_dqblk);
}

/* Compute block number from given offset */
static inline unsigned int ol_dqblk_file_block(struct super_block *sb, loff_t off)
{
	return off >> sb->s_blocksize_bits;
}

static inline unsigned int ol_dqblk_block_offset(struct super_block *sb, loff_t off)
{
	return off & ((1 << sb->s_blocksize_bits) - 1);
}

/* Compute offset in the chunk of a structure with the given offset */
static int ol_dqblk_chunk_off(struct super_block *sb, int c, loff_t off)
{
	int epb = ol_quota_entries_per_block(sb);

	return ((off >> sb->s_blocksize_bits) -
			ol_quota_chunk_block(sb, c) - 1) * epb
	       + ((unsigned int)(off & ((1 << sb->s_blocksize_bits) - 1))) /
		 sizeof(struct ocfs2_local_disk_dqblk);
}

/* Write bufferhead into the fs */
static int ocfs2_modify_bh(struct inode *inode, struct buffer_head *bh,
		void (*modify)(struct buffer_head *, void *), void *private)
{
	struct super_block *sb = inode->i_sb;
	handle_t *handle;
	int status;

	handle = ocfs2_start_trans(OCFS2_SB(sb), 1);
	if (IS_ERR(handle)) {
		status = PTR_ERR(handle);
		mlog_errno(status);
		return status;
	}
	status = ocfs2_journal_access(handle, inode, bh,
				      OCFS2_JOURNAL_ACCESS_WRITE);
	if (status < 0) {
		mlog_errno(status);
		ocfs2_commit_trans(OCFS2_SB(sb), handle);
		return status;
	}
	lock_buffer(bh);
	modify(bh, private);
	unlock_buffer(bh);
	status = ocfs2_journal_dirty(handle, bh);
	if (status < 0) {
		mlog_errno(status);
		ocfs2_commit_trans(OCFS2_SB(sb), handle);
		return status;
	}
	status = ocfs2_commit_trans(OCFS2_SB(sb), handle);
	if (status < 0) {
		mlog_errno(status);
		return status;
	}
	return 0;
}

/* Check whether we understand format of quota files */
static int ocfs2_local_check_quota_file(struct super_block *sb, int type)
{
	unsigned int lmagics[MAXQUOTAS] = OCFS2_LOCAL_QMAGICS;
	unsigned int lversions[MAXQUOTAS] = OCFS2_LOCAL_QVERSIONS;
	unsigned int gmagics[MAXQUOTAS] = OCFS2_GLOBAL_QMAGICS;
	unsigned int gversions[MAXQUOTAS] = OCFS2_GLOBAL_QVERSIONS;
	unsigned int ino[MAXQUOTAS] = { USER_QUOTA_SYSTEM_INODE,
					GROUP_QUOTA_SYSTEM_INODE };
	struct buffer_head *bh;
	struct inode *linode = sb_dqopt(sb)->files[type];
	struct inode *ginode = NULL;
	struct ocfs2_disk_dqheader *dqhead;
	int status, ret = 0;

	/* First check whether we understand local quota file */
	bh = ocfs2_read_quota_block(linode, 0, &status);
	if (!bh) {
		mlog_errno(status);
		mlog(ML_ERROR, "failed to read quota file header (type=%d)\n",
			type);
		goto out_err;
	}
	dqhead = (struct ocfs2_disk_dqheader *)(bh->b_data);
	if (le32_to_cpu(dqhead->dqh_magic) != lmagics[type]) {
		mlog(ML_ERROR, "quota file magic does not match (%u != %u),"
			" type=%d\n", le32_to_cpu(dqhead->dqh_magic),
			lmagics[type], type);
		goto out_err;
	}
	if (le32_to_cpu(dqhead->dqh_version) != lversions[type]) {
		mlog(ML_ERROR, "quota file version does not match (%u != %u),"
			" type=%d\n", le32_to_cpu(dqhead->dqh_version),
			lversions[type], type);
		goto out_err;
	}
	brelse(bh);
	bh = NULL;

	/* Next check whether we understand global quota file */
	ginode = ocfs2_get_system_file_inode(OCFS2_SB(sb), ino[type],
						OCFS2_INVALID_SLOT);
	if (!ginode) {
		mlog(ML_ERROR, "cannot get global quota file inode "
				"(type=%d)\n", type);
		goto out_err;
	}
	/* Since the header is read only, we don't care about locking */
	bh = ocfs2_read_quota_block(ginode, 0, &status);
	if (!bh) {
		mlog_errno(status);
		mlog(ML_ERROR, "failed to read global quota file header "
				"(type=%d)\n", type);
		goto out_err;
	}
	dqhead = (struct ocfs2_disk_dqheader *)(bh->b_data);
	if (le32_to_cpu(dqhead->dqh_magic) != gmagics[type]) {
		mlog(ML_ERROR, "global quota file magic does not match "
			"(%u != %u), type=%d\n",
			le32_to_cpu(dqhead->dqh_magic), gmagics[type], type);
		goto out_err;
	}
	if (le32_to_cpu(dqhead->dqh_version) != gversions[type]) {
		mlog(ML_ERROR, "global quota file version does not match "
			"(%u != %u), type=%d\n",
			le32_to_cpu(dqhead->dqh_version), gversions[type],
			type);
		goto out_err;
	}

	ret = 1;
out_err:
	brelse(bh);
	iput(ginode);
	return ret;
}

/* Release given list of quota file chunks */
static void ocfs2_release_local_quota_bitmaps(struct list_head *head)
{
	struct ocfs2_quota_chunk *pos, *next;

	list_for_each_entry_safe(pos, next, head, qc_chunk) {
		list_del(&pos->qc_chunk);
		brelse(pos->qc_headerbh);
		kmem_cache_free(ocfs2_qf_chunk_cachep, pos);
	}
}

/* Load quota bitmaps into memory */
static int ocfs2_load_local_quota_bitmaps(struct inode *inode,
			struct ocfs2_local_disk_dqinfo *ldinfo,
			struct list_head *head)
{
	struct ocfs2_quota_chunk *newchunk;
	int i, status;

	INIT_LIST_HEAD(head);
	for (i = 0; i < le32_to_cpu(ldinfo->dqi_chunks); i++) {
		newchunk = kmem_cache_alloc(ocfs2_qf_chunk_cachep, GFP_NOFS);
		if (!newchunk) {
			ocfs2_release_local_quota_bitmaps(head);
			return -ENOMEM;
		}
		newchunk->qc_num = i;
		newchunk->qc_headerbh = ocfs2_read_quota_block(inode,
				ol_quota_chunk_block(inode->i_sb, i),
				&status);
		if (!newchunk->qc_headerbh) {
			mlog_errno(status);
			kmem_cache_free(ocfs2_qf_chunk_cachep, newchunk);
			ocfs2_release_local_quota_bitmaps(head);
			return status;
		}
		list_add_tail(&newchunk->qc_chunk, head);
	}
	return 0;
}

static void olq_update_info(struct buffer_head *bh, void *private)
{
	struct mem_dqinfo *info = private;
	struct ocfs2_mem_dqinfo *oinfo = info->dqi_priv;
	struct ocfs2_local_disk_dqinfo *ldinfo;

	ldinfo = (struct ocfs2_local_disk_dqinfo *)(bh->b_data +
						OCFS2_LOCAL_INFO_OFF);
	spin_lock(&dq_data_lock);
	ldinfo->dqi_flags = cpu_to_le32(info->dqi_flags & DQF_MASK);
	ldinfo->dqi_chunks = cpu_to_le32(oinfo->dqi_chunks);
	ldinfo->dqi_blocks = cpu_to_le32(oinfo->dqi_blocks);
	spin_unlock(&dq_data_lock);
}

/* Read information header from quota file */
static int ocfs2_local_read_info(struct super_block *sb, int type)
{
	struct ocfs2_local_disk_dqinfo *ldinfo;
	struct mem_dqinfo *info = sb_dqinfo(sb, type);
	struct ocfs2_mem_dqinfo *oinfo;
	struct inode *lqinode = sb_dqopt(sb)->files[type];
	int status;
	struct buffer_head *bh = NULL;
	int locked = 0;

	info->dqi_maxblimit = 0x7fffffffffffffffLL;
	info->dqi_maxilimit = 0x7fffffffffffffffLL;
	oinfo = kmalloc(sizeof(struct ocfs2_mem_dqinfo), GFP_NOFS);
	if (!oinfo) {
		mlog(ML_ERROR, "failed to allocate memory for ocfs2 quota"
			       " info.");
		goto out_err;
	}
	info->dqi_priv = oinfo;
	oinfo->dqi_type = type;
	INIT_LIST_HEAD(&oinfo->dqi_chunk);
	oinfo->dqi_lqi_bh = NULL;
	oinfo->dqi_ibh = NULL;

	status = ocfs2_global_read_info(sb, type);
	if (status < 0)
		goto out_err;

	status = ocfs2_inode_lock(lqinode, &oinfo->dqi_lqi_bh, 1);
	if (status < 0) {
		mlog_errno(status);
		goto out_err;
	}
	locked = 1;

	/* Now read local header */
	bh = ocfs2_read_quota_block(lqinode, 0, &status);
	if (!bh) {
		mlog_errno(status);
		mlog(ML_ERROR, "failed to read quota file info header "
			"(type=%d)\n", type);
		goto out_err;
	}
	ldinfo = (struct ocfs2_local_disk_dqinfo *)(bh->b_data +
						OCFS2_LOCAL_INFO_OFF);
	info->dqi_flags = le32_to_cpu(ldinfo->dqi_flags);
	oinfo->dqi_chunks = le32_to_cpu(ldinfo->dqi_chunks);
	oinfo->dqi_blocks = le32_to_cpu(ldinfo->dqi_blocks);
	oinfo->dqi_ibh = bh;

	/* We crashed when using local quota file? */
	if (!(info->dqi_flags & OLQF_CLEAN))
		goto out_err;	/* So far we just bail out. Later we should resync here */

	status = ocfs2_load_local_quota_bitmaps(sb_dqopt(sb)->files[type],
						ldinfo,
						&oinfo->dqi_chunk);
	if (status < 0) {
		mlog_errno(status);
		goto out_err;
	}

	/* Now mark quota file as used */
	info->dqi_flags &= ~OLQF_CLEAN;
	status = ocfs2_modify_bh(lqinode, bh, olq_update_info, info);
	if (status < 0) {
		mlog_errno(status);
		goto out_err;
	}

	return 0;
out_err:
	if (oinfo) {
		iput(oinfo->dqi_gqinode);
		ocfs2_simple_drop_lockres(OCFS2_SB(sb), &oinfo->dqi_gqlock);
		ocfs2_lock_res_free(&oinfo->dqi_gqlock);
		brelse(oinfo->dqi_lqi_bh);
		if (locked)
			ocfs2_inode_unlock(lqinode, 1);
		ocfs2_release_local_quota_bitmaps(&oinfo->dqi_chunk);
		kfree(oinfo);
	}
	brelse(bh);
	return -1;
}

/* Write local info to quota file */
static int ocfs2_local_write_info(struct super_block *sb, int type)
{
	struct mem_dqinfo *info = sb_dqinfo(sb, type);
	struct buffer_head *bh = ((struct ocfs2_mem_dqinfo *)info->dqi_priv)
						->dqi_ibh;
	int status;

	status = ocfs2_modify_bh(sb_dqopt(sb)->files[type], bh, olq_update_info,
				 info);
	if (status < 0) {
		mlog_errno(status);
		return -1;
	}

	return 0;
}

/* Release info from memory */
static int ocfs2_local_free_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_quota_chunk *chunk;
	struct ocfs2_local_disk_chunk *dchunk;
	int mark_clean = 1, len;
	int status;

	iput(oinfo->dqi_gqinode);
	ocfs2_simple_drop_lockres(OCFS2_SB(sb), &oinfo->dqi_gqlock);
	ocfs2_lock_res_free(&oinfo->dqi_gqlock);
	list_for_each_entry(chunk, &oinfo->dqi_chunk, qc_chunk) {
		dchunk = (struct ocfs2_local_disk_chunk *)
					(chunk->qc_headerbh->b_data);
		if (chunk->qc_num < oinfo->dqi_chunks - 1) {
			len = ol_chunk_entries(sb);
		} else {
			len = (oinfo->dqi_blocks -
			       ol_quota_chunk_block(sb, chunk->qc_num) - 1)
			      * ol_quota_entries_per_block(sb);
		}
		/* Not all entries free? Bug! */
		if (le32_to_cpu(dchunk->dqc_free) != len) {
			mlog(ML_ERROR, "releasing quota file with used "
					"entries (type=%d)\n", type);
			mark_clean = 0;
		}
	}
	ocfs2_release_local_quota_bitmaps(&oinfo->dqi_chunk);

	if (!mark_clean)
		goto out;

	/* Mark local file as clean */
	info->dqi_flags |= OLQF_CLEAN;
	status = ocfs2_modify_bh(sb_dqopt(sb)->files[type],
				 oinfo->dqi_ibh,
				 olq_update_info,
				 info);
	if (status < 0) {
		mlog_errno(status);
		goto out;
	}

out:
	ocfs2_inode_unlock(sb_dqopt(sb)->files[type], 1);
	brelse(oinfo->dqi_ibh);
	brelse(oinfo->dqi_lqi_bh);
	kfree(oinfo);
	return 0;
}

static void olq_set_dquot(struct buffer_head *bh, void *private)
{
	struct ocfs2_dquot *od = private;
	struct ocfs2_local_disk_dqblk *dqblk;
	struct super_block *sb = od->dq_dquot.dq_sb;

	dqblk = (struct ocfs2_local_disk_dqblk *)(bh->b_data
		+ ol_dqblk_block_offset(sb, od->dq_local_off));

	dqblk->dqb_id = cpu_to_le64(od->dq_dquot.dq_id);
	spin_lock(&dq_data_lock);
	dqblk->dqb_spacemod = cpu_to_le64(od->dq_dquot.dq_dqb.dqb_curspace -
					  od->dq_origspace);
	dqblk->dqb_inodemod = cpu_to_le64(od->dq_dquot.dq_dqb.dqb_curinodes -
					  od->dq_originodes);
	spin_unlock(&dq_data_lock);
	mlog(0, "Writing local dquot %u space %lld inodes %lld\n",
	     od->dq_dquot.dq_id, dqblk->dqb_spacemod, dqblk->dqb_inodemod);
}

/* Write dquot to local quota file */
static int ocfs2_local_write_dquot(struct dquot *dquot)
{
	struct super_block *sb = dquot->dq_sb;
	struct ocfs2_dquot *od = OCFS2_DQUOT(dquot);
	struct buffer_head *bh;
	int status;

	bh = ocfs2_read_quota_block(sb_dqopt(sb)->files[dquot->dq_type],
				    ol_dqblk_file_block(sb, od->dq_local_off),
				    &status);
	if (!bh) {
		mlog_errno(status);
		goto out;
	}
	status = ocfs2_modify_bh(sb_dqopt(sb)->files[dquot->dq_type], bh,
				 olq_set_dquot, od);
	if (status < 0) {
		mlog_errno(status);
		goto out;
	}
out:
	brelse(bh);
	return status;
}

/* Find free entry in local quota file */
static struct ocfs2_quota_chunk *ocfs2_find_free_entry(struct super_block *sb,
						       int type,
						       int *offset)
{
	struct mem_dqinfo *info = sb_dqinfo(sb, type);
	struct ocfs2_mem_dqinfo *oinfo = info->dqi_priv;
	struct ocfs2_quota_chunk *chunk;
	struct ocfs2_local_disk_chunk *dchunk;
	int found = 0, len;

	list_for_each_entry(chunk, &oinfo->dqi_chunk, qc_chunk) {
		dchunk = (struct ocfs2_local_disk_chunk *)
						chunk->qc_headerbh->b_data;
		if (le32_to_cpu(dchunk->dqc_free) > 0) {
			found = 1;
			break;
		}
	}
	if (!found)
		return NULL;

	if (chunk->qc_num < oinfo->dqi_chunks - 1) {
		len = ol_chunk_entries(sb);
	} else {
		len = (oinfo->dqi_blocks -
		       ol_quota_chunk_block(sb, chunk->qc_num) - 1)
		      * ol_quota_entries_per_block(sb);
	}

	found = ocfs2_find_next_zero_bit(dchunk->dqc_bitmap, len, 0);
	/* We failed? */
	if (found == len) {
		mlog(ML_ERROR, "Did not find empty entry in chunk %d with %u"
		     " entries free (type=%d)\n", chunk->qc_num,
		     le32_to_cpu(dchunk->dqc_free), type);
		return ERR_PTR(-EIO);
	}
	*offset = found;
	return chunk;
}

/* Add new chunk to the local quota file */
static struct ocfs2_quota_chunk *ocfs2_local_quota_add_chunk(
							struct super_block *sb,
							int type,
							int *offset)
{
	struct mem_dqinfo *info = sb_dqinfo(sb, type);
	struct ocfs2_mem_dqinfo *oinfo = info->dqi_priv;
	struct inode *lqinode = sb_dqopt(sb)->files[type];
	struct ocfs2_quota_chunk *chunk = NULL;
	struct ocfs2_local_disk_chunk *dchunk;
	int status;
	handle_t *handle;
	struct buffer_head *bh = NULL;
	u64 p_blkno;

	/* We are protected by dqio_sem so no locking needed */
	status = ocfs2_extend_no_holes(lqinode,
				       lqinode->i_size + 2 * sb->s_blocksize,
				       lqinode->i_size);
	if (status < 0) {
		mlog_errno(status);
		goto out;
	}
	status = ocfs2_simple_size_update(lqinode, oinfo->dqi_lqi_bh,
					  lqinode->i_size + 2 * sb->s_blocksize);
	if (status < 0) {
		mlog_errno(status);
		goto out;
	}

	chunk = kmem_cache_alloc(ocfs2_qf_chunk_cachep, GFP_NOFS);
	if (!chunk) {
		status = -ENOMEM;
		mlog_errno(status);
		goto out;
	}

	down_read(&OCFS2_I(lqinode)->ip_alloc_sem);
	status = ocfs2_extent_map_get_blocks(lqinode, oinfo->dqi_blocks,
					     &p_blkno, NULL, NULL);
	up_read(&OCFS2_I(lqinode)->ip_alloc_sem);
	if (status < 0) {
		mlog_errno(status);
		goto out;
	}
	bh = sb_getblk(sb, p_blkno);
	if (!bh) {
		status = -ENOMEM;
		mlog_errno(status);
		goto out;
	}
	dchunk = (struct ocfs2_local_disk_chunk *)bh->b_data;

	handle = ocfs2_start_trans(OCFS2_SB(sb), 2);
	if (IS_ERR(handle)) {
		status = PTR_ERR(handle);
		mlog_errno(status);
		goto out;
	}

	status = ocfs2_journal_access(handle, lqinode, bh,
				      OCFS2_JOURNAL_ACCESS_WRITE);
	if (status < 0) {
		mlog_errno(status);
		goto out_trans;
	}
	lock_buffer(bh);
	dchunk->dqc_free = ol_quota_entries_per_block(sb);
	memset(dchunk->dqc_bitmap, 0,
	       sb->s_blocksize - sizeof(struct ocfs2_local_disk_chunk) -
	       OCFS2_QBLK_RESERVED_SPACE);
	set_buffer_uptodate(bh);
	unlock_buffer(bh);
	status = ocfs2_journal_dirty(handle, bh);
	if (status < 0) {
		mlog_errno(status);
		goto out_trans;
	}

	oinfo->dqi_blocks += 2;
	oinfo->dqi_chunks++;
	status = ocfs2_local_write_info(sb, type);
	if (status < 0) {
		mlog_errno(status);
		goto out_trans;
	}
	status = ocfs2_commit_trans(OCFS2_SB(sb), handle);
	if (status < 0) {
		mlog_errno(status);
		goto out;
	}

	list_add_tail(&chunk->qc_chunk, &oinfo->dqi_chunk);
	chunk->qc_num = list_entry(chunk->qc_chunk.prev,
				   struct ocfs2_quota_chunk,
				   qc_chunk)->qc_num + 1;
	chunk->qc_headerbh = bh;
	*offset = 0;
	return chunk;
out_trans:
	ocfs2_commit_trans(OCFS2_SB(sb), handle);
out:
	brelse(bh);
	kmem_cache_free(ocfs2_qf_chunk_cachep, chunk);
	return ERR_PTR(status);
}

/* Find free entry in local quota file */
static struct ocfs2_quota_chunk *ocfs2_extend_local_quota_file(
						       struct super_block *sb,
						       int type,
						       int *offset)
{
	struct mem_dqinfo *info = sb_dqinfo(sb, type);
	struct ocfs2_mem_dqinfo *oinfo = info->dqi_priv;
	struct ocfs2_quota_chunk *chunk;
	struct inode *lqinode = sb_dqopt(sb)->files[type];
	struct ocfs2_local_disk_chunk *dchunk;
	int epb = ol_quota_entries_per_block(sb);
	unsigned int chunk_blocks;
	int status;
	handle_t *handle;

	if (list_empty(&oinfo->dqi_chunk))
		return ocfs2_local_quota_add_chunk(sb, type, offset);
	/* Is the last chunk full? */
	chunk = list_entry(oinfo->dqi_chunk.prev,
			struct ocfs2_quota_chunk, qc_chunk);
	chunk_blocks = oinfo->dqi_blocks -
			ol_quota_chunk_block(sb, chunk->qc_num) - 1;
	if (ol_chunk_blocks(sb) == chunk_blocks)
		return ocfs2_local_quota_add_chunk(sb, type, offset);

	/* We are protected by dqio_sem so no locking needed */
	status = ocfs2_extend_no_holes(lqinode,
				       lqinode->i_size + sb->s_blocksize,
				       lqinode->i_size);
	if (status < 0) {
		mlog_errno(status);
		goto out;
	}
	status = ocfs2_simple_size_update(lqinode, oinfo->dqi_lqi_bh,
					  lqinode->i_size + sb->s_blocksize);
	if (status < 0) {
		mlog_errno(status);
		goto out;
	}
	handle = ocfs2_start_trans(OCFS2_SB(sb), 2);
	if (IS_ERR(handle)) {
		status = PTR_ERR(handle);
		mlog_errno(status);
		goto out;
	}
	status = ocfs2_journal_access(handle, lqinode, chunk->qc_headerbh,
				 OCFS2_JOURNAL_ACCESS_WRITE);
	if (status < 0) {
		mlog_errno(status);
		goto out_trans;
	}

	dchunk = (struct ocfs2_local_disk_chunk *)chunk->qc_headerbh->b_data;
	lock_buffer(chunk->qc_headerbh);
	le32_add_cpu(&dchunk->dqc_free, ol_quota_entries_per_block(sb));
	unlock_buffer(chunk->qc_headerbh);
	status = ocfs2_journal_dirty(handle, chunk->qc_headerbh);
	if (status < 0) {
		mlog_errno(status);
		goto out_trans;
	}
	oinfo->dqi_blocks++;
	status = ocfs2_local_write_info(sb, type);
	if (status < 0) {
		mlog_errno(status);
		goto out_trans;
	}

	status = ocfs2_commit_trans(OCFS2_SB(sb), handle);
	if (status < 0) {
		mlog_errno(status);
		goto out;
	}
	*offset = chunk_blocks * epb;
	return chunk;
out_trans:
	ocfs2_commit_trans(OCFS2_SB(sb), handle);
out:
	return ERR_PTR(status);
}

void olq_alloc_dquot(struct buffer_head *bh, void *private)
{
	int *offset = private;
	struct ocfs2_local_disk_chunk *dchunk;

	dchunk = (struct ocfs2_local_disk_chunk *)bh->b_data;
	ocfs2_set_bit(*offset, dchunk->dqc_bitmap);
	le32_add_cpu(&dchunk->dqc_free, -1);
}

/* Create dquot in the local file for given id */
static int ocfs2_create_local_dquot(struct dquot *dquot)
{
	struct super_block *sb = dquot->dq_sb;
	int type = dquot->dq_type;
	struct inode *lqinode = sb_dqopt(sb)->files[type];
	struct ocfs2_quota_chunk *chunk;
	struct ocfs2_dquot *od = OCFS2_DQUOT(dquot);
	int offset;
	int status;

	chunk = ocfs2_find_free_entry(sb, type, &offset);
	if (!chunk) {
		chunk = ocfs2_extend_local_quota_file(sb, type, &offset);
		if (IS_ERR(chunk))
			return PTR_ERR(chunk);
	} else if (IS_ERR(chunk)) {
		return PTR_ERR(chunk);
	}
	od->dq_local_off = ol_dqblk_off(sb, chunk->qc_num, offset);
	od->dq_chunk = chunk;

	/* Initialize dquot structure on disk */
	status = ocfs2_local_write_dquot(dquot);
	if (status < 0) {
		mlog_errno(status);
		goto out;
	}

	/* Mark structure as allocated */
	status = ocfs2_modify_bh(lqinode, chunk->qc_headerbh, olq_alloc_dquot,
				 &offset);
	if (status < 0) {
		mlog_errno(status);
		goto out;
	}
out:
	return status;
}

/* Create entry in local file for dquot, load data from the global file */
static int ocfs2_local_read_dquot(struct dquot *dquot)
{
	int status;

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

	status = ocfs2_global_read_dquot(dquot);
	if (status < 0) {
		mlog_errno(status);
		goto out_err;
	}

	/* Now create entry in the local quota file */
	status = ocfs2_create_local_dquot(dquot);
	if (status < 0) {
		mlog_errno(status);
		goto out_err;
	}
	mlog_exit(0);
	return 0;
out_err:
	mlog_exit(status);
	return status;
}

/* Release dquot structure from local quota file. ocfs2_release_dquot() has
 * already started a transaction and obtained exclusive lock for global
 * quota file. */
static int ocfs2_local_release_dquot(struct dquot *dquot)
{
	int status;
	int type = dquot->dq_type;
	struct ocfs2_dquot *od = OCFS2_DQUOT(dquot);
	struct super_block *sb = dquot->dq_sb;
	struct ocfs2_local_disk_chunk *dchunk;
	int offset;
	handle_t *handle = journal_current_handle();

	BUG_ON(!handle);
	/* First write all local changes to global file */
	status = ocfs2_global_release_dquot(dquot);
	if (status < 0) {
		mlog_errno(status);
		goto out;
	}

	status = ocfs2_journal_access(handle, sb_dqopt(sb)->files[type],
			od->dq_chunk->qc_headerbh, OCFS2_JOURNAL_ACCESS_WRITE);
	if (status < 0) {
		mlog_errno(status);
		goto out;
	}
	offset = ol_dqblk_chunk_off(sb, od->dq_chunk->qc_num,
					     od->dq_local_off);
	dchunk = (struct ocfs2_local_disk_chunk *)
			(od->dq_chunk->qc_headerbh->b_data);
	/* Mark structure as freed */
	lock_buffer(od->dq_chunk->qc_headerbh);
	ocfs2_clear_bit(offset, dchunk->dqc_bitmap);
	le32_add_cpu(&dchunk->dqc_free, 1);
	unlock_buffer(od->dq_chunk->qc_headerbh);
	status = ocfs2_journal_dirty(handle, od->dq_chunk->qc_headerbh);
	if (status < 0) {
		mlog_errno(status);
		goto out;
	}
	status = 0;
out:
	/* Clear the read bit so that next time someone uses this
	 * dquot he reads fresh info from disk and allocates local
	 * dquot structure */
	clear_bit(DQ_READ_B, &dquot->dq_flags);
	return status;
}

static struct quota_format_ops ocfs2_format_ops = {
	.check_quota_file	= ocfs2_local_check_quota_file,
	.read_file_info		= ocfs2_local_read_info,
	.write_file_info	= ocfs2_global_write_info,
	.free_file_info		= ocfs2_local_free_info,
	.read_dqblk		= ocfs2_local_read_dquot,
	.commit_dqblk		= ocfs2_local_write_dquot,
	.release_dqblk		= ocfs2_local_release_dquot,
};

struct quota_format_type ocfs2_quota_format = {
	.qf_fmt_id = QFMT_OCFS2,
	.qf_ops = &ocfs2_format_ops,
	.qf_owner = THIS_MODULE
};