summaryrefslogtreecommitdiff
path: root/fs/xfs/xfs_bmap_item.c
blob: 6e2f0013380a66937d42b822d9608d9c0f5df26f (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
// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2016 Oracle.  All Rights Reserved.
 * Author: Darrick J. Wong <darrick.wong@oracle.com>
 */
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_bit.h"
#include "xfs_shared.h"
#include "xfs_mount.h"
#include "xfs_defer.h"
#include "xfs_inode.h"
#include "xfs_trans.h"
#include "xfs_trans_priv.h"
#include "xfs_bmap_item.h"
#include "xfs_log.h"
#include "xfs_bmap.h"
#include "xfs_icache.h"
#include "xfs_bmap_btree.h"
#include "xfs_trans_space.h"
#include "xfs_error.h"
#include "xfs_log_priv.h"
#include "xfs_log_recover.h"

struct kmem_cache	*xfs_bui_cache;
struct kmem_cache	*xfs_bud_cache;

static const struct xfs_item_ops xfs_bui_item_ops;

static inline struct xfs_bui_log_item *BUI_ITEM(struct xfs_log_item *lip)
{
	return container_of(lip, struct xfs_bui_log_item, bui_item);
}

STATIC void
xfs_bui_item_free(
	struct xfs_bui_log_item	*buip)
{
	kmem_free(buip->bui_item.li_lv_shadow);
	kmem_cache_free(xfs_bui_cache, buip);
}

/*
 * Freeing the BUI requires that we remove it from the AIL if it has already
 * been placed there. However, the BUI may not yet have been placed in the AIL
 * when called by xfs_bui_release() from BUD processing due to the ordering of
 * committed vs unpin operations in bulk insert operations. Hence the reference
 * count to ensure only the last caller frees the BUI.
 */
STATIC void
xfs_bui_release(
	struct xfs_bui_log_item	*buip)
{
	ASSERT(atomic_read(&buip->bui_refcount) > 0);
	if (!atomic_dec_and_test(&buip->bui_refcount))
		return;

	xfs_trans_ail_delete(&buip->bui_item, 0);
	xfs_bui_item_free(buip);
}


STATIC void
xfs_bui_item_size(
	struct xfs_log_item	*lip,
	int			*nvecs,
	int			*nbytes)
{
	struct xfs_bui_log_item	*buip = BUI_ITEM(lip);

	*nvecs += 1;
	*nbytes += xfs_bui_log_format_sizeof(buip->bui_format.bui_nextents);
}

/*
 * This is called to fill in the vector of log iovecs for the
 * given bui log item. We use only 1 iovec, and we point that
 * at the bui_log_format structure embedded in the bui item.
 * It is at this point that we assert that all of the extent
 * slots in the bui item have been filled.
 */
STATIC void
xfs_bui_item_format(
	struct xfs_log_item	*lip,
	struct xfs_log_vec	*lv)
{
	struct xfs_bui_log_item	*buip = BUI_ITEM(lip);
	struct xfs_log_iovec	*vecp = NULL;

	ASSERT(atomic_read(&buip->bui_next_extent) ==
			buip->bui_format.bui_nextents);

	buip->bui_format.bui_type = XFS_LI_BUI;
	buip->bui_format.bui_size = 1;

	xlog_copy_iovec(lv, &vecp, XLOG_REG_TYPE_BUI_FORMAT, &buip->bui_format,
			xfs_bui_log_format_sizeof(buip->bui_format.bui_nextents));
}

/*
 * The unpin operation is the last place an BUI is manipulated in the log. It is
 * either inserted in the AIL or aborted in the event of a log I/O error. In
 * either case, the BUI transaction has been successfully committed to make it
 * this far. Therefore, we expect whoever committed the BUI to either construct
 * and commit the BUD or drop the BUD's reference in the event of error. Simply
 * drop the log's BUI reference now that the log is done with it.
 */
STATIC void
xfs_bui_item_unpin(
	struct xfs_log_item	*lip,
	int			remove)
{
	struct xfs_bui_log_item	*buip = BUI_ITEM(lip);

	xfs_bui_release(buip);
}

/*
 * The BUI has been either committed or aborted if the transaction has been
 * cancelled. If the transaction was cancelled, an BUD isn't going to be
 * constructed and thus we free the BUI here directly.
 */
STATIC void
xfs_bui_item_release(
	struct xfs_log_item	*lip)
{
	xfs_bui_release(BUI_ITEM(lip));
}

/*
 * Allocate and initialize an bui item with the given number of extents.
 */
STATIC struct xfs_bui_log_item *
xfs_bui_init(
	struct xfs_mount		*mp)

{
	struct xfs_bui_log_item		*buip;

	buip = kmem_cache_zalloc(xfs_bui_cache, GFP_KERNEL | __GFP_NOFAIL);

	xfs_log_item_init(mp, &buip->bui_item, XFS_LI_BUI, &xfs_bui_item_ops);
	buip->bui_format.bui_nextents = XFS_BUI_MAX_FAST_EXTENTS;
	buip->bui_format.bui_id = (uintptr_t)(void *)buip;
	atomic_set(&buip->bui_next_extent, 0);
	atomic_set(&buip->bui_refcount, 2);

	return buip;
}

static inline struct xfs_bud_log_item *BUD_ITEM(struct xfs_log_item *lip)
{
	return container_of(lip, struct xfs_bud_log_item, bud_item);
}

STATIC void
xfs_bud_item_size(
	struct xfs_log_item	*lip,
	int			*nvecs,
	int			*nbytes)
{
	*nvecs += 1;
	*nbytes += sizeof(struct xfs_bud_log_format);
}

/*
 * This is called to fill in the vector of log iovecs for the
 * given bud log item. We use only 1 iovec, and we point that
 * at the bud_log_format structure embedded in the bud item.
 * It is at this point that we assert that all of the extent
 * slots in the bud item have been filled.
 */
STATIC void
xfs_bud_item_format(
	struct xfs_log_item	*lip,
	struct xfs_log_vec	*lv)
{
	struct xfs_bud_log_item	*budp = BUD_ITEM(lip);
	struct xfs_log_iovec	*vecp = NULL;

	budp->bud_format.bud_type = XFS_LI_BUD;
	budp->bud_format.bud_size = 1;

	xlog_copy_iovec(lv, &vecp, XLOG_REG_TYPE_BUD_FORMAT, &budp->bud_format,
			sizeof(struct xfs_bud_log_format));
}

/*
 * The BUD is either committed or aborted if the transaction is cancelled. If
 * the transaction is cancelled, drop our reference to the BUI and free the
 * BUD.
 */
STATIC void
xfs_bud_item_release(
	struct xfs_log_item	*lip)
{
	struct xfs_bud_log_item	*budp = BUD_ITEM(lip);

	xfs_bui_release(budp->bud_buip);
	kmem_free(budp->bud_item.li_lv_shadow);
	kmem_cache_free(xfs_bud_cache, budp);
}

static struct xfs_log_item *
xfs_bud_item_intent(
	struct xfs_log_item	*lip)
{
	return &BUD_ITEM(lip)->bud_buip->bui_item;
}

static const struct xfs_item_ops xfs_bud_item_ops = {
	.flags		= XFS_ITEM_RELEASE_WHEN_COMMITTED |
			  XFS_ITEM_INTENT_DONE,
	.iop_size	= xfs_bud_item_size,
	.iop_format	= xfs_bud_item_format,
	.iop_release	= xfs_bud_item_release,
	.iop_intent	= xfs_bud_item_intent,
};

static struct xfs_bud_log_item *
xfs_trans_get_bud(
	struct xfs_trans		*tp,
	struct xfs_bui_log_item		*buip)
{
	struct xfs_bud_log_item		*budp;

	budp = kmem_cache_zalloc(xfs_bud_cache, GFP_KERNEL | __GFP_NOFAIL);
	xfs_log_item_init(tp->t_mountp, &budp->bud_item, XFS_LI_BUD,
			  &xfs_bud_item_ops);
	budp->bud_buip = buip;
	budp->bud_format.bud_bui_id = buip->bui_format.bui_id;

	xfs_trans_add_item(tp, &budp->bud_item);
	return budp;
}

/*
 * Finish an bmap update and log it to the BUD. Note that the
 * transaction is marked dirty regardless of whether the bmap update
 * succeeds or fails to support the BUI/BUD lifecycle rules.
 */
static int
xfs_trans_log_finish_bmap_update(
	struct xfs_trans		*tp,
	struct xfs_bud_log_item		*budp,
	struct xfs_bmap_intent		*bi)
{
	int				error;

	error = xfs_bmap_finish_one(tp, bi);

	/*
	 * Mark the transaction dirty, even on error. This ensures the
	 * transaction is aborted, which:
	 *
	 * 1.) releases the BUI and frees the BUD
	 * 2.) shuts down the filesystem
	 */
	tp->t_flags |= XFS_TRANS_DIRTY | XFS_TRANS_HAS_INTENT_DONE;
	set_bit(XFS_LI_DIRTY, &budp->bud_item.li_flags);

	return error;
}

/* Sort bmap intents by inode. */
static int
xfs_bmap_update_diff_items(
	void				*priv,
	const struct list_head		*a,
	const struct list_head		*b)
{
	struct xfs_bmap_intent		*ba;
	struct xfs_bmap_intent		*bb;

	ba = container_of(a, struct xfs_bmap_intent, bi_list);
	bb = container_of(b, struct xfs_bmap_intent, bi_list);
	return ba->bi_owner->i_ino - bb->bi_owner->i_ino;
}

/* Set the map extent flags for this mapping. */
static void
xfs_trans_set_bmap_flags(
	struct xfs_map_extent		*map,
	enum xfs_bmap_intent_type	type,
	int				whichfork,
	xfs_exntst_t			state)
{
	map->me_flags = 0;
	switch (type) {
	case XFS_BMAP_MAP:
	case XFS_BMAP_UNMAP:
		map->me_flags = type;
		break;
	default:
		ASSERT(0);
	}
	if (state == XFS_EXT_UNWRITTEN)
		map->me_flags |= XFS_BMAP_EXTENT_UNWRITTEN;
	if (whichfork == XFS_ATTR_FORK)
		map->me_flags |= XFS_BMAP_EXTENT_ATTR_FORK;
}

/* Log bmap updates in the intent item. */
STATIC void
xfs_bmap_update_log_item(
	struct xfs_trans		*tp,
	struct xfs_bui_log_item		*buip,
	struct xfs_bmap_intent		*bi)
{
	uint				next_extent;
	struct xfs_map_extent		*map;

	tp->t_flags |= XFS_TRANS_DIRTY;
	set_bit(XFS_LI_DIRTY, &buip->bui_item.li_flags);

	/*
	 * atomic_inc_return gives us the value after the increment;
	 * we want to use it as an array index so we need to subtract 1 from
	 * it.
	 */
	next_extent = atomic_inc_return(&buip->bui_next_extent) - 1;
	ASSERT(next_extent < buip->bui_format.bui_nextents);
	map = &buip->bui_format.bui_extents[next_extent];
	map->me_owner = bi->bi_owner->i_ino;
	map->me_startblock = bi->bi_bmap.br_startblock;
	map->me_startoff = bi->bi_bmap.br_startoff;
	map->me_len = bi->bi_bmap.br_blockcount;
	xfs_trans_set_bmap_flags(map, bi->bi_type, bi->bi_whichfork,
			bi->bi_bmap.br_state);
}

static struct xfs_log_item *
xfs_bmap_update_create_intent(
	struct xfs_trans		*tp,
	struct list_head		*items,
	unsigned int			count,
	bool				sort)
{
	struct xfs_mount		*mp = tp->t_mountp;
	struct xfs_bui_log_item		*buip = xfs_bui_init(mp);
	struct xfs_bmap_intent		*bi;

	ASSERT(count == XFS_BUI_MAX_FAST_EXTENTS);

	xfs_trans_add_item(tp, &buip->bui_item);
	if (sort)
		list_sort(mp, items, xfs_bmap_update_diff_items);
	list_for_each_entry(bi, items, bi_list)
		xfs_bmap_update_log_item(tp, buip, bi);
	return &buip->bui_item;
}

/* Get an BUD so we can process all the deferred rmap updates. */
static struct xfs_log_item *
xfs_bmap_update_create_done(
	struct xfs_trans		*tp,
	struct xfs_log_item		*intent,
	unsigned int			count)
{
	return &xfs_trans_get_bud(tp, BUI_ITEM(intent))->bud_item;
}

/* Process a deferred rmap update. */
STATIC int
xfs_bmap_update_finish_item(
	struct xfs_trans		*tp,
	struct xfs_log_item		*done,
	struct list_head		*item,
	struct xfs_btree_cur		**state)
{
	struct xfs_bmap_intent		*bi;
	int				error;

	bi = container_of(item, struct xfs_bmap_intent, bi_list);

	error = xfs_trans_log_finish_bmap_update(tp, BUD_ITEM(done), bi);
	if (!error && bi->bi_bmap.br_blockcount > 0) {
		ASSERT(bi->bi_type == XFS_BMAP_UNMAP);
		return -EAGAIN;
	}
	kmem_cache_free(xfs_bmap_intent_cache, bi);
	return error;
}

/* Abort all pending BUIs. */
STATIC void
xfs_bmap_update_abort_intent(
	struct xfs_log_item		*intent)
{
	xfs_bui_release(BUI_ITEM(intent));
}

/* Cancel a deferred rmap update. */
STATIC void
xfs_bmap_update_cancel_item(
	struct list_head		*item)
{
	struct xfs_bmap_intent		*bi;

	bi = container_of(item, struct xfs_bmap_intent, bi_list);
	kmem_cache_free(xfs_bmap_intent_cache, bi);
}

const struct xfs_defer_op_type xfs_bmap_update_defer_type = {
	.max_items	= XFS_BUI_MAX_FAST_EXTENTS,
	.create_intent	= xfs_bmap_update_create_intent,
	.abort_intent	= xfs_bmap_update_abort_intent,
	.create_done	= xfs_bmap_update_create_done,
	.finish_item	= xfs_bmap_update_finish_item,
	.cancel_item	= xfs_bmap_update_cancel_item,
};

/* Is this recovered BUI ok? */
static inline bool
xfs_bui_validate(
	struct xfs_mount		*mp,
	struct xfs_bui_log_item		*buip)
{
	struct xfs_map_extent		*map;

	/* Only one mapping operation per BUI... */
	if (buip->bui_format.bui_nextents != XFS_BUI_MAX_FAST_EXTENTS)
		return false;

	map = &buip->bui_format.bui_extents[0];

	if (map->me_flags & ~XFS_BMAP_EXTENT_FLAGS)
		return false;

	switch (map->me_flags & XFS_BMAP_EXTENT_TYPE_MASK) {
	case XFS_BMAP_MAP:
	case XFS_BMAP_UNMAP:
		break;
	default:
		return false;
	}

	if (!xfs_verify_ino(mp, map->me_owner))
		return false;

	if (!xfs_verify_fileext(mp, map->me_startoff, map->me_len))
		return false;

	return xfs_verify_fsbext(mp, map->me_startblock, map->me_len);
}

/*
 * Process a bmap update intent item that was recovered from the log.
 * We need to update some inode's bmbt.
 */
STATIC int
xfs_bui_item_recover(
	struct xfs_log_item		*lip,
	struct list_head		*capture_list)
{
	struct xfs_bmap_intent		fake = { };
	struct xfs_bui_log_item		*buip = BUI_ITEM(lip);
	struct xfs_trans		*tp;
	struct xfs_inode		*ip = NULL;
	struct xfs_mount		*mp = lip->li_log->l_mp;
	struct xfs_map_extent		*map;
	struct xfs_bud_log_item		*budp;
	int				iext_delta;
	int				error = 0;

	if (!xfs_bui_validate(mp, buip)) {
		XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp,
				&buip->bui_format, sizeof(buip->bui_format));
		return -EFSCORRUPTED;
	}

	map = &buip->bui_format.bui_extents[0];
	fake.bi_whichfork = (map->me_flags & XFS_BMAP_EXTENT_ATTR_FORK) ?
			XFS_ATTR_FORK : XFS_DATA_FORK;
	fake.bi_type = map->me_flags & XFS_BMAP_EXTENT_TYPE_MASK;

	error = xlog_recover_iget(mp, map->me_owner, &ip);
	if (error)
		return error;

	/* Allocate transaction and do the work. */
	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate,
			XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK), 0, 0, &tp);
	if (error)
		goto err_rele;

	budp = xfs_trans_get_bud(tp, buip);
	xfs_ilock(ip, XFS_ILOCK_EXCL);
	xfs_trans_ijoin(tp, ip, 0);

	if (fake.bi_type == XFS_BMAP_MAP)
		iext_delta = XFS_IEXT_ADD_NOSPLIT_CNT;
	else
		iext_delta = XFS_IEXT_PUNCH_HOLE_CNT;

	error = xfs_iext_count_may_overflow(ip, fake.bi_whichfork, iext_delta);
	if (error == -EFBIG)
		error = xfs_iext_count_upgrade(tp, ip, iext_delta);
	if (error)
		goto err_cancel;

	fake.bi_owner = ip;
	fake.bi_bmap.br_startblock = map->me_startblock;
	fake.bi_bmap.br_startoff = map->me_startoff;
	fake.bi_bmap.br_blockcount = map->me_len;
	fake.bi_bmap.br_state = (map->me_flags & XFS_BMAP_EXTENT_UNWRITTEN) ?
			XFS_EXT_UNWRITTEN : XFS_EXT_NORM;

	error = xfs_trans_log_finish_bmap_update(tp, budp, &fake);
	if (error == -EFSCORRUPTED)
		XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, map,
				sizeof(*map));
	if (error)
		goto err_cancel;

	if (fake.bi_bmap.br_blockcount > 0) {
		ASSERT(fake.bi_type == XFS_BMAP_UNMAP);
		xfs_bmap_unmap_extent(tp, ip, &fake.bi_bmap);
	}

	/*
	 * Commit transaction, which frees the transaction and saves the inode
	 * for later replay activities.
	 */
	error = xfs_defer_ops_capture_and_commit(tp, capture_list);
	if (error)
		goto err_unlock;

	xfs_iunlock(ip, XFS_ILOCK_EXCL);
	xfs_irele(ip);
	return 0;

err_cancel:
	xfs_trans_cancel(tp);
err_unlock:
	xfs_iunlock(ip, XFS_ILOCK_EXCL);
err_rele:
	xfs_irele(ip);
	return error;
}

STATIC bool
xfs_bui_item_match(
	struct xfs_log_item	*lip,
	uint64_t		intent_id)
{
	return BUI_ITEM(lip)->bui_format.bui_id == intent_id;
}

/* Relog an intent item to push the log tail forward. */
static struct xfs_log_item *
xfs_bui_item_relog(
	struct xfs_log_item		*intent,
	struct xfs_trans		*tp)
{
	struct xfs_bud_log_item		*budp;
	struct xfs_bui_log_item		*buip;
	struct xfs_map_extent		*map;
	unsigned int			count;

	count = BUI_ITEM(intent)->bui_format.bui_nextents;
	map = BUI_ITEM(intent)->bui_format.bui_extents;

	tp->t_flags |= XFS_TRANS_DIRTY;
	budp = xfs_trans_get_bud(tp, BUI_ITEM(intent));
	set_bit(XFS_LI_DIRTY, &budp->bud_item.li_flags);

	buip = xfs_bui_init(tp->t_mountp);
	memcpy(buip->bui_format.bui_extents, map, count * sizeof(*map));
	atomic_set(&buip->bui_next_extent, count);
	xfs_trans_add_item(tp, &buip->bui_item);
	set_bit(XFS_LI_DIRTY, &buip->bui_item.li_flags);
	return &buip->bui_item;
}

static const struct xfs_item_ops xfs_bui_item_ops = {
	.flags		= XFS_ITEM_INTENT,
	.iop_size	= xfs_bui_item_size,
	.iop_format	= xfs_bui_item_format,
	.iop_unpin	= xfs_bui_item_unpin,
	.iop_release	= xfs_bui_item_release,
	.iop_recover	= xfs_bui_item_recover,
	.iop_match	= xfs_bui_item_match,
	.iop_relog	= xfs_bui_item_relog,
};

static inline void
xfs_bui_copy_format(
	struct xfs_bui_log_format	*dst,
	const struct xfs_bui_log_format	*src)
{
	unsigned int			i;

	memcpy(dst, src, offsetof(struct xfs_bui_log_format, bui_extents));

	for (i = 0; i < src->bui_nextents; i++)
		memcpy(&dst->bui_extents[i], &src->bui_extents[i],
				sizeof(struct xfs_map_extent));
}

/*
 * This routine is called to create an in-core extent bmap update
 * item from the bui format structure which was logged on disk.
 * It allocates an in-core bui, copies the extents from the format
 * structure into it, and adds the bui to the AIL with the given
 * LSN.
 */
STATIC int
xlog_recover_bui_commit_pass2(
	struct xlog			*log,
	struct list_head		*buffer_list,
	struct xlog_recover_item	*item,
	xfs_lsn_t			lsn)
{
	struct xfs_mount		*mp = log->l_mp;
	struct xfs_bui_log_item		*buip;
	struct xfs_bui_log_format	*bui_formatp;
	size_t				len;

	bui_formatp = item->ri_buf[0].i_addr;

	if (item->ri_buf[0].i_len < xfs_bui_log_format_sizeof(0)) {
		XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp,
				item->ri_buf[0].i_addr, item->ri_buf[0].i_len);
		return -EFSCORRUPTED;
	}

	if (bui_formatp->bui_nextents != XFS_BUI_MAX_FAST_EXTENTS) {
		XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp,
				item->ri_buf[0].i_addr, item->ri_buf[0].i_len);
		return -EFSCORRUPTED;
	}

	len = xfs_bui_log_format_sizeof(bui_formatp->bui_nextents);
	if (item->ri_buf[0].i_len != len) {
		XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp,
				item->ri_buf[0].i_addr, item->ri_buf[0].i_len);
		return -EFSCORRUPTED;
	}

	buip = xfs_bui_init(mp);
	xfs_bui_copy_format(&buip->bui_format, bui_formatp);
	atomic_set(&buip->bui_next_extent, bui_formatp->bui_nextents);
	/*
	 * Insert the intent into the AIL directly and drop one reference so
	 * that finishing or canceling the work will drop the other.
	 */
	xfs_trans_ail_insert(log->l_ailp, &buip->bui_item, lsn);
	xfs_bui_release(buip);
	return 0;
}

const struct xlog_recover_item_ops xlog_bui_item_ops = {
	.item_type		= XFS_LI_BUI,
	.commit_pass2		= xlog_recover_bui_commit_pass2,
};

/*
 * This routine is called when an BUD format structure is found in a committed
 * transaction in the log. Its purpose is to cancel the corresponding BUI if it
 * was still in the log. To do this it searches the AIL for the BUI with an id
 * equal to that in the BUD format structure. If we find it we drop the BUD
 * reference, which removes the BUI from the AIL and frees it.
 */
STATIC int
xlog_recover_bud_commit_pass2(
	struct xlog			*log,
	struct list_head		*buffer_list,
	struct xlog_recover_item	*item,
	xfs_lsn_t			lsn)
{
	struct xfs_bud_log_format	*bud_formatp;

	bud_formatp = item->ri_buf[0].i_addr;
	if (item->ri_buf[0].i_len != sizeof(struct xfs_bud_log_format)) {
		XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, log->l_mp,
				item->ri_buf[0].i_addr, item->ri_buf[0].i_len);
		return -EFSCORRUPTED;
	}

	xlog_recover_release_intent(log, XFS_LI_BUI, bud_formatp->bud_bui_id);
	return 0;
}

const struct xlog_recover_item_ops xlog_bud_item_ops = {
	.item_type		= XFS_LI_BUD,
	.commit_pass2		= xlog_recover_bud_commit_pass2,
};