xref: /openbmc/linux/fs/xfs/xfs_bmap_item.c (revision 47aab533)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2016 Oracle.  All Rights Reserved.
4  * Author: Darrick J. Wong <darrick.wong@oracle.com>
5  */
6 #include "xfs.h"
7 #include "xfs_fs.h"
8 #include "xfs_format.h"
9 #include "xfs_log_format.h"
10 #include "xfs_trans_resv.h"
11 #include "xfs_bit.h"
12 #include "xfs_shared.h"
13 #include "xfs_mount.h"
14 #include "xfs_defer.h"
15 #include "xfs_inode.h"
16 #include "xfs_trans.h"
17 #include "xfs_trans_priv.h"
18 #include "xfs_bmap_item.h"
19 #include "xfs_log.h"
20 #include "xfs_bmap.h"
21 #include "xfs_icache.h"
22 #include "xfs_bmap_btree.h"
23 #include "xfs_trans_space.h"
24 #include "xfs_error.h"
25 #include "xfs_log_priv.h"
26 #include "xfs_log_recover.h"
27 #include "xfs_ag.h"
28 
29 struct kmem_cache	*xfs_bui_cache;
30 struct kmem_cache	*xfs_bud_cache;
31 
32 static const struct xfs_item_ops xfs_bui_item_ops;
33 
34 static inline struct xfs_bui_log_item *BUI_ITEM(struct xfs_log_item *lip)
35 {
36 	return container_of(lip, struct xfs_bui_log_item, bui_item);
37 }
38 
39 STATIC void
40 xfs_bui_item_free(
41 	struct xfs_bui_log_item	*buip)
42 {
43 	kmem_free(buip->bui_item.li_lv_shadow);
44 	kmem_cache_free(xfs_bui_cache, buip);
45 }
46 
47 /*
48  * Freeing the BUI requires that we remove it from the AIL if it has already
49  * been placed there. However, the BUI may not yet have been placed in the AIL
50  * when called by xfs_bui_release() from BUD processing due to the ordering of
51  * committed vs unpin operations in bulk insert operations. Hence the reference
52  * count to ensure only the last caller frees the BUI.
53  */
54 STATIC void
55 xfs_bui_release(
56 	struct xfs_bui_log_item	*buip)
57 {
58 	ASSERT(atomic_read(&buip->bui_refcount) > 0);
59 	if (!atomic_dec_and_test(&buip->bui_refcount))
60 		return;
61 
62 	xfs_trans_ail_delete(&buip->bui_item, 0);
63 	xfs_bui_item_free(buip);
64 }
65 
66 
67 STATIC void
68 xfs_bui_item_size(
69 	struct xfs_log_item	*lip,
70 	int			*nvecs,
71 	int			*nbytes)
72 {
73 	struct xfs_bui_log_item	*buip = BUI_ITEM(lip);
74 
75 	*nvecs += 1;
76 	*nbytes += xfs_bui_log_format_sizeof(buip->bui_format.bui_nextents);
77 }
78 
79 /*
80  * This is called to fill in the vector of log iovecs for the
81  * given bui log item. We use only 1 iovec, and we point that
82  * at the bui_log_format structure embedded in the bui item.
83  * It is at this point that we assert that all of the extent
84  * slots in the bui item have been filled.
85  */
86 STATIC void
87 xfs_bui_item_format(
88 	struct xfs_log_item	*lip,
89 	struct xfs_log_vec	*lv)
90 {
91 	struct xfs_bui_log_item	*buip = BUI_ITEM(lip);
92 	struct xfs_log_iovec	*vecp = NULL;
93 
94 	ASSERT(atomic_read(&buip->bui_next_extent) ==
95 			buip->bui_format.bui_nextents);
96 
97 	buip->bui_format.bui_type = XFS_LI_BUI;
98 	buip->bui_format.bui_size = 1;
99 
100 	xlog_copy_iovec(lv, &vecp, XLOG_REG_TYPE_BUI_FORMAT, &buip->bui_format,
101 			xfs_bui_log_format_sizeof(buip->bui_format.bui_nextents));
102 }
103 
104 /*
105  * The unpin operation is the last place an BUI is manipulated in the log. It is
106  * either inserted in the AIL or aborted in the event of a log I/O error. In
107  * either case, the BUI transaction has been successfully committed to make it
108  * this far. Therefore, we expect whoever committed the BUI to either construct
109  * and commit the BUD or drop the BUD's reference in the event of error. Simply
110  * drop the log's BUI reference now that the log is done with it.
111  */
112 STATIC void
113 xfs_bui_item_unpin(
114 	struct xfs_log_item	*lip,
115 	int			remove)
116 {
117 	struct xfs_bui_log_item	*buip = BUI_ITEM(lip);
118 
119 	xfs_bui_release(buip);
120 }
121 
122 /*
123  * The BUI has been either committed or aborted if the transaction has been
124  * cancelled. If the transaction was cancelled, an BUD isn't going to be
125  * constructed and thus we free the BUI here directly.
126  */
127 STATIC void
128 xfs_bui_item_release(
129 	struct xfs_log_item	*lip)
130 {
131 	xfs_bui_release(BUI_ITEM(lip));
132 }
133 
134 /*
135  * Allocate and initialize an bui item with the given number of extents.
136  */
137 STATIC struct xfs_bui_log_item *
138 xfs_bui_init(
139 	struct xfs_mount		*mp)
140 
141 {
142 	struct xfs_bui_log_item		*buip;
143 
144 	buip = kmem_cache_zalloc(xfs_bui_cache, GFP_KERNEL | __GFP_NOFAIL);
145 
146 	xfs_log_item_init(mp, &buip->bui_item, XFS_LI_BUI, &xfs_bui_item_ops);
147 	buip->bui_format.bui_nextents = XFS_BUI_MAX_FAST_EXTENTS;
148 	buip->bui_format.bui_id = (uintptr_t)(void *)buip;
149 	atomic_set(&buip->bui_next_extent, 0);
150 	atomic_set(&buip->bui_refcount, 2);
151 
152 	return buip;
153 }
154 
155 static inline struct xfs_bud_log_item *BUD_ITEM(struct xfs_log_item *lip)
156 {
157 	return container_of(lip, struct xfs_bud_log_item, bud_item);
158 }
159 
160 STATIC void
161 xfs_bud_item_size(
162 	struct xfs_log_item	*lip,
163 	int			*nvecs,
164 	int			*nbytes)
165 {
166 	*nvecs += 1;
167 	*nbytes += sizeof(struct xfs_bud_log_format);
168 }
169 
170 /*
171  * This is called to fill in the vector of log iovecs for the
172  * given bud log item. We use only 1 iovec, and we point that
173  * at the bud_log_format structure embedded in the bud item.
174  * It is at this point that we assert that all of the extent
175  * slots in the bud item have been filled.
176  */
177 STATIC void
178 xfs_bud_item_format(
179 	struct xfs_log_item	*lip,
180 	struct xfs_log_vec	*lv)
181 {
182 	struct xfs_bud_log_item	*budp = BUD_ITEM(lip);
183 	struct xfs_log_iovec	*vecp = NULL;
184 
185 	budp->bud_format.bud_type = XFS_LI_BUD;
186 	budp->bud_format.bud_size = 1;
187 
188 	xlog_copy_iovec(lv, &vecp, XLOG_REG_TYPE_BUD_FORMAT, &budp->bud_format,
189 			sizeof(struct xfs_bud_log_format));
190 }
191 
192 /*
193  * The BUD is either committed or aborted if the transaction is cancelled. If
194  * the transaction is cancelled, drop our reference to the BUI and free the
195  * BUD.
196  */
197 STATIC void
198 xfs_bud_item_release(
199 	struct xfs_log_item	*lip)
200 {
201 	struct xfs_bud_log_item	*budp = BUD_ITEM(lip);
202 
203 	xfs_bui_release(budp->bud_buip);
204 	kmem_free(budp->bud_item.li_lv_shadow);
205 	kmem_cache_free(xfs_bud_cache, budp);
206 }
207 
208 static struct xfs_log_item *
209 xfs_bud_item_intent(
210 	struct xfs_log_item	*lip)
211 {
212 	return &BUD_ITEM(lip)->bud_buip->bui_item;
213 }
214 
215 static const struct xfs_item_ops xfs_bud_item_ops = {
216 	.flags		= XFS_ITEM_RELEASE_WHEN_COMMITTED |
217 			  XFS_ITEM_INTENT_DONE,
218 	.iop_size	= xfs_bud_item_size,
219 	.iop_format	= xfs_bud_item_format,
220 	.iop_release	= xfs_bud_item_release,
221 	.iop_intent	= xfs_bud_item_intent,
222 };
223 
224 static struct xfs_bud_log_item *
225 xfs_trans_get_bud(
226 	struct xfs_trans		*tp,
227 	struct xfs_bui_log_item		*buip)
228 {
229 	struct xfs_bud_log_item		*budp;
230 
231 	budp = kmem_cache_zalloc(xfs_bud_cache, GFP_KERNEL | __GFP_NOFAIL);
232 	xfs_log_item_init(tp->t_mountp, &budp->bud_item, XFS_LI_BUD,
233 			  &xfs_bud_item_ops);
234 	budp->bud_buip = buip;
235 	budp->bud_format.bud_bui_id = buip->bui_format.bui_id;
236 
237 	xfs_trans_add_item(tp, &budp->bud_item);
238 	return budp;
239 }
240 
241 /*
242  * Finish an bmap update and log it to the BUD. Note that the
243  * transaction is marked dirty regardless of whether the bmap update
244  * succeeds or fails to support the BUI/BUD lifecycle rules.
245  */
246 static int
247 xfs_trans_log_finish_bmap_update(
248 	struct xfs_trans		*tp,
249 	struct xfs_bud_log_item		*budp,
250 	struct xfs_bmap_intent		*bi)
251 {
252 	int				error;
253 
254 	error = xfs_bmap_finish_one(tp, bi);
255 
256 	/*
257 	 * Mark the transaction dirty, even on error. This ensures the
258 	 * transaction is aborted, which:
259 	 *
260 	 * 1.) releases the BUI and frees the BUD
261 	 * 2.) shuts down the filesystem
262 	 */
263 	tp->t_flags |= XFS_TRANS_DIRTY | XFS_TRANS_HAS_INTENT_DONE;
264 	set_bit(XFS_LI_DIRTY, &budp->bud_item.li_flags);
265 
266 	return error;
267 }
268 
269 /* Sort bmap intents by inode. */
270 static int
271 xfs_bmap_update_diff_items(
272 	void				*priv,
273 	const struct list_head		*a,
274 	const struct list_head		*b)
275 {
276 	struct xfs_bmap_intent		*ba;
277 	struct xfs_bmap_intent		*bb;
278 
279 	ba = container_of(a, struct xfs_bmap_intent, bi_list);
280 	bb = container_of(b, struct xfs_bmap_intent, bi_list);
281 	return ba->bi_owner->i_ino - bb->bi_owner->i_ino;
282 }
283 
284 /* Set the map extent flags for this mapping. */
285 static void
286 xfs_trans_set_bmap_flags(
287 	struct xfs_map_extent		*map,
288 	enum xfs_bmap_intent_type	type,
289 	int				whichfork,
290 	xfs_exntst_t			state)
291 {
292 	map->me_flags = 0;
293 	switch (type) {
294 	case XFS_BMAP_MAP:
295 	case XFS_BMAP_UNMAP:
296 		map->me_flags = type;
297 		break;
298 	default:
299 		ASSERT(0);
300 	}
301 	if (state == XFS_EXT_UNWRITTEN)
302 		map->me_flags |= XFS_BMAP_EXTENT_UNWRITTEN;
303 	if (whichfork == XFS_ATTR_FORK)
304 		map->me_flags |= XFS_BMAP_EXTENT_ATTR_FORK;
305 }
306 
307 /* Log bmap updates in the intent item. */
308 STATIC void
309 xfs_bmap_update_log_item(
310 	struct xfs_trans		*tp,
311 	struct xfs_bui_log_item		*buip,
312 	struct xfs_bmap_intent		*bi)
313 {
314 	uint				next_extent;
315 	struct xfs_map_extent		*map;
316 
317 	tp->t_flags |= XFS_TRANS_DIRTY;
318 	set_bit(XFS_LI_DIRTY, &buip->bui_item.li_flags);
319 
320 	/*
321 	 * atomic_inc_return gives us the value after the increment;
322 	 * we want to use it as an array index so we need to subtract 1 from
323 	 * it.
324 	 */
325 	next_extent = atomic_inc_return(&buip->bui_next_extent) - 1;
326 	ASSERT(next_extent < buip->bui_format.bui_nextents);
327 	map = &buip->bui_format.bui_extents[next_extent];
328 	map->me_owner = bi->bi_owner->i_ino;
329 	map->me_startblock = bi->bi_bmap.br_startblock;
330 	map->me_startoff = bi->bi_bmap.br_startoff;
331 	map->me_len = bi->bi_bmap.br_blockcount;
332 	xfs_trans_set_bmap_flags(map, bi->bi_type, bi->bi_whichfork,
333 			bi->bi_bmap.br_state);
334 }
335 
336 static struct xfs_log_item *
337 xfs_bmap_update_create_intent(
338 	struct xfs_trans		*tp,
339 	struct list_head		*items,
340 	unsigned int			count,
341 	bool				sort)
342 {
343 	struct xfs_mount		*mp = tp->t_mountp;
344 	struct xfs_bui_log_item		*buip = xfs_bui_init(mp);
345 	struct xfs_bmap_intent		*bi;
346 
347 	ASSERT(count == XFS_BUI_MAX_FAST_EXTENTS);
348 
349 	xfs_trans_add_item(tp, &buip->bui_item);
350 	if (sort)
351 		list_sort(mp, items, xfs_bmap_update_diff_items);
352 	list_for_each_entry(bi, items, bi_list)
353 		xfs_bmap_update_log_item(tp, buip, bi);
354 	return &buip->bui_item;
355 }
356 
357 /* Get an BUD so we can process all the deferred rmap updates. */
358 static struct xfs_log_item *
359 xfs_bmap_update_create_done(
360 	struct xfs_trans		*tp,
361 	struct xfs_log_item		*intent,
362 	unsigned int			count)
363 {
364 	return &xfs_trans_get_bud(tp, BUI_ITEM(intent))->bud_item;
365 }
366 
367 /* Take a passive ref to the AG containing the space we're mapping. */
368 void
369 xfs_bmap_update_get_group(
370 	struct xfs_mount	*mp,
371 	struct xfs_bmap_intent	*bi)
372 {
373 	xfs_agnumber_t		agno;
374 
375 	agno = XFS_FSB_TO_AGNO(mp, bi->bi_bmap.br_startblock);
376 
377 	/*
378 	 * Bump the intent count on behalf of the deferred rmap and refcount
379 	 * intent items that that we can queue when we finish this bmap work.
380 	 * This new intent item will bump the intent count before the bmap
381 	 * intent drops the intent count, ensuring that the intent count
382 	 * remains nonzero across the transaction roll.
383 	 */
384 	bi->bi_pag = xfs_perag_intent_get(mp, agno);
385 }
386 
387 /* Release a passive AG ref after finishing mapping work. */
388 static inline void
389 xfs_bmap_update_put_group(
390 	struct xfs_bmap_intent	*bi)
391 {
392 	xfs_perag_intent_put(bi->bi_pag);
393 }
394 
395 /* Process a deferred rmap update. */
396 STATIC int
397 xfs_bmap_update_finish_item(
398 	struct xfs_trans		*tp,
399 	struct xfs_log_item		*done,
400 	struct list_head		*item,
401 	struct xfs_btree_cur		**state)
402 {
403 	struct xfs_bmap_intent		*bi;
404 	int				error;
405 
406 	bi = container_of(item, struct xfs_bmap_intent, bi_list);
407 
408 	error = xfs_trans_log_finish_bmap_update(tp, BUD_ITEM(done), bi);
409 	if (!error && bi->bi_bmap.br_blockcount > 0) {
410 		ASSERT(bi->bi_type == XFS_BMAP_UNMAP);
411 		return -EAGAIN;
412 	}
413 
414 	xfs_bmap_update_put_group(bi);
415 	kmem_cache_free(xfs_bmap_intent_cache, bi);
416 	return error;
417 }
418 
419 /* Abort all pending BUIs. */
420 STATIC void
421 xfs_bmap_update_abort_intent(
422 	struct xfs_log_item		*intent)
423 {
424 	xfs_bui_release(BUI_ITEM(intent));
425 }
426 
427 /* Cancel a deferred bmap update. */
428 STATIC void
429 xfs_bmap_update_cancel_item(
430 	struct list_head		*item)
431 {
432 	struct xfs_bmap_intent		*bi;
433 
434 	bi = container_of(item, struct xfs_bmap_intent, bi_list);
435 
436 	xfs_bmap_update_put_group(bi);
437 	kmem_cache_free(xfs_bmap_intent_cache, bi);
438 }
439 
440 const struct xfs_defer_op_type xfs_bmap_update_defer_type = {
441 	.max_items	= XFS_BUI_MAX_FAST_EXTENTS,
442 	.create_intent	= xfs_bmap_update_create_intent,
443 	.abort_intent	= xfs_bmap_update_abort_intent,
444 	.create_done	= xfs_bmap_update_create_done,
445 	.finish_item	= xfs_bmap_update_finish_item,
446 	.cancel_item	= xfs_bmap_update_cancel_item,
447 };
448 
449 /* Is this recovered BUI ok? */
450 static inline bool
451 xfs_bui_validate(
452 	struct xfs_mount		*mp,
453 	struct xfs_bui_log_item		*buip)
454 {
455 	struct xfs_map_extent		*map;
456 
457 	/* Only one mapping operation per BUI... */
458 	if (buip->bui_format.bui_nextents != XFS_BUI_MAX_FAST_EXTENTS)
459 		return false;
460 
461 	map = &buip->bui_format.bui_extents[0];
462 
463 	if (map->me_flags & ~XFS_BMAP_EXTENT_FLAGS)
464 		return false;
465 
466 	switch (map->me_flags & XFS_BMAP_EXTENT_TYPE_MASK) {
467 	case XFS_BMAP_MAP:
468 	case XFS_BMAP_UNMAP:
469 		break;
470 	default:
471 		return false;
472 	}
473 
474 	if (!xfs_verify_ino(mp, map->me_owner))
475 		return false;
476 
477 	if (!xfs_verify_fileext(mp, map->me_startoff, map->me_len))
478 		return false;
479 
480 	return xfs_verify_fsbext(mp, map->me_startblock, map->me_len);
481 }
482 
483 /*
484  * Process a bmap update intent item that was recovered from the log.
485  * We need to update some inode's bmbt.
486  */
487 STATIC int
488 xfs_bui_item_recover(
489 	struct xfs_log_item		*lip,
490 	struct list_head		*capture_list)
491 {
492 	struct xfs_bmap_intent		fake = { };
493 	struct xfs_bui_log_item		*buip = BUI_ITEM(lip);
494 	struct xfs_trans		*tp;
495 	struct xfs_inode		*ip = NULL;
496 	struct xfs_mount		*mp = lip->li_log->l_mp;
497 	struct xfs_map_extent		*map;
498 	struct xfs_bud_log_item		*budp;
499 	int				iext_delta;
500 	int				error = 0;
501 
502 	if (!xfs_bui_validate(mp, buip)) {
503 		XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp,
504 				&buip->bui_format, sizeof(buip->bui_format));
505 		return -EFSCORRUPTED;
506 	}
507 
508 	map = &buip->bui_format.bui_extents[0];
509 	fake.bi_whichfork = (map->me_flags & XFS_BMAP_EXTENT_ATTR_FORK) ?
510 			XFS_ATTR_FORK : XFS_DATA_FORK;
511 	fake.bi_type = map->me_flags & XFS_BMAP_EXTENT_TYPE_MASK;
512 
513 	error = xlog_recover_iget(mp, map->me_owner, &ip);
514 	if (error)
515 		return error;
516 
517 	/* Allocate transaction and do the work. */
518 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate,
519 			XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK), 0, 0, &tp);
520 	if (error)
521 		goto err_rele;
522 
523 	budp = xfs_trans_get_bud(tp, buip);
524 	xfs_ilock(ip, XFS_ILOCK_EXCL);
525 	xfs_trans_ijoin(tp, ip, 0);
526 
527 	if (fake.bi_type == XFS_BMAP_MAP)
528 		iext_delta = XFS_IEXT_ADD_NOSPLIT_CNT;
529 	else
530 		iext_delta = XFS_IEXT_PUNCH_HOLE_CNT;
531 
532 	error = xfs_iext_count_may_overflow(ip, fake.bi_whichfork, iext_delta);
533 	if (error == -EFBIG)
534 		error = xfs_iext_count_upgrade(tp, ip, iext_delta);
535 	if (error)
536 		goto err_cancel;
537 
538 	fake.bi_owner = ip;
539 	fake.bi_bmap.br_startblock = map->me_startblock;
540 	fake.bi_bmap.br_startoff = map->me_startoff;
541 	fake.bi_bmap.br_blockcount = map->me_len;
542 	fake.bi_bmap.br_state = (map->me_flags & XFS_BMAP_EXTENT_UNWRITTEN) ?
543 			XFS_EXT_UNWRITTEN : XFS_EXT_NORM;
544 
545 	xfs_bmap_update_get_group(mp, &fake);
546 	error = xfs_trans_log_finish_bmap_update(tp, budp, &fake);
547 	if (error == -EFSCORRUPTED)
548 		XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, map,
549 				sizeof(*map));
550 	xfs_bmap_update_put_group(&fake);
551 	if (error)
552 		goto err_cancel;
553 
554 	if (fake.bi_bmap.br_blockcount > 0) {
555 		ASSERT(fake.bi_type == XFS_BMAP_UNMAP);
556 		xfs_bmap_unmap_extent(tp, ip, &fake.bi_bmap);
557 	}
558 
559 	/*
560 	 * Commit transaction, which frees the transaction and saves the inode
561 	 * for later replay activities.
562 	 */
563 	error = xfs_defer_ops_capture_and_commit(tp, capture_list);
564 	if (error)
565 		goto err_unlock;
566 
567 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
568 	xfs_irele(ip);
569 	return 0;
570 
571 err_cancel:
572 	xfs_trans_cancel(tp);
573 err_unlock:
574 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
575 err_rele:
576 	xfs_irele(ip);
577 	return error;
578 }
579 
580 STATIC bool
581 xfs_bui_item_match(
582 	struct xfs_log_item	*lip,
583 	uint64_t		intent_id)
584 {
585 	return BUI_ITEM(lip)->bui_format.bui_id == intent_id;
586 }
587 
588 /* Relog an intent item to push the log tail forward. */
589 static struct xfs_log_item *
590 xfs_bui_item_relog(
591 	struct xfs_log_item		*intent,
592 	struct xfs_trans		*tp)
593 {
594 	struct xfs_bud_log_item		*budp;
595 	struct xfs_bui_log_item		*buip;
596 	struct xfs_map_extent		*map;
597 	unsigned int			count;
598 
599 	count = BUI_ITEM(intent)->bui_format.bui_nextents;
600 	map = BUI_ITEM(intent)->bui_format.bui_extents;
601 
602 	tp->t_flags |= XFS_TRANS_DIRTY;
603 	budp = xfs_trans_get_bud(tp, BUI_ITEM(intent));
604 	set_bit(XFS_LI_DIRTY, &budp->bud_item.li_flags);
605 
606 	buip = xfs_bui_init(tp->t_mountp);
607 	memcpy(buip->bui_format.bui_extents, map, count * sizeof(*map));
608 	atomic_set(&buip->bui_next_extent, count);
609 	xfs_trans_add_item(tp, &buip->bui_item);
610 	set_bit(XFS_LI_DIRTY, &buip->bui_item.li_flags);
611 	return &buip->bui_item;
612 }
613 
614 static const struct xfs_item_ops xfs_bui_item_ops = {
615 	.flags		= XFS_ITEM_INTENT,
616 	.iop_size	= xfs_bui_item_size,
617 	.iop_format	= xfs_bui_item_format,
618 	.iop_unpin	= xfs_bui_item_unpin,
619 	.iop_release	= xfs_bui_item_release,
620 	.iop_recover	= xfs_bui_item_recover,
621 	.iop_match	= xfs_bui_item_match,
622 	.iop_relog	= xfs_bui_item_relog,
623 };
624 
625 static inline void
626 xfs_bui_copy_format(
627 	struct xfs_bui_log_format	*dst,
628 	const struct xfs_bui_log_format	*src)
629 {
630 	unsigned int			i;
631 
632 	memcpy(dst, src, offsetof(struct xfs_bui_log_format, bui_extents));
633 
634 	for (i = 0; i < src->bui_nextents; i++)
635 		memcpy(&dst->bui_extents[i], &src->bui_extents[i],
636 				sizeof(struct xfs_map_extent));
637 }
638 
639 /*
640  * This routine is called to create an in-core extent bmap update
641  * item from the bui format structure which was logged on disk.
642  * It allocates an in-core bui, copies the extents from the format
643  * structure into it, and adds the bui to the AIL with the given
644  * LSN.
645  */
646 STATIC int
647 xlog_recover_bui_commit_pass2(
648 	struct xlog			*log,
649 	struct list_head		*buffer_list,
650 	struct xlog_recover_item	*item,
651 	xfs_lsn_t			lsn)
652 {
653 	struct xfs_mount		*mp = log->l_mp;
654 	struct xfs_bui_log_item		*buip;
655 	struct xfs_bui_log_format	*bui_formatp;
656 	size_t				len;
657 
658 	bui_formatp = item->ri_buf[0].i_addr;
659 
660 	if (item->ri_buf[0].i_len < xfs_bui_log_format_sizeof(0)) {
661 		XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp,
662 				item->ri_buf[0].i_addr, item->ri_buf[0].i_len);
663 		return -EFSCORRUPTED;
664 	}
665 
666 	if (bui_formatp->bui_nextents != XFS_BUI_MAX_FAST_EXTENTS) {
667 		XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp,
668 				item->ri_buf[0].i_addr, item->ri_buf[0].i_len);
669 		return -EFSCORRUPTED;
670 	}
671 
672 	len = xfs_bui_log_format_sizeof(bui_formatp->bui_nextents);
673 	if (item->ri_buf[0].i_len != len) {
674 		XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp,
675 				item->ri_buf[0].i_addr, item->ri_buf[0].i_len);
676 		return -EFSCORRUPTED;
677 	}
678 
679 	buip = xfs_bui_init(mp);
680 	xfs_bui_copy_format(&buip->bui_format, bui_formatp);
681 	atomic_set(&buip->bui_next_extent, bui_formatp->bui_nextents);
682 	/*
683 	 * Insert the intent into the AIL directly and drop one reference so
684 	 * that finishing or canceling the work will drop the other.
685 	 */
686 	xfs_trans_ail_insert(log->l_ailp, &buip->bui_item, lsn);
687 	xfs_bui_release(buip);
688 	return 0;
689 }
690 
691 const struct xlog_recover_item_ops xlog_bui_item_ops = {
692 	.item_type		= XFS_LI_BUI,
693 	.commit_pass2		= xlog_recover_bui_commit_pass2,
694 };
695 
696 /*
697  * This routine is called when an BUD format structure is found in a committed
698  * transaction in the log. Its purpose is to cancel the corresponding BUI if it
699  * was still in the log. To do this it searches the AIL for the BUI with an id
700  * equal to that in the BUD format structure. If we find it we drop the BUD
701  * reference, which removes the BUI from the AIL and frees it.
702  */
703 STATIC int
704 xlog_recover_bud_commit_pass2(
705 	struct xlog			*log,
706 	struct list_head		*buffer_list,
707 	struct xlog_recover_item	*item,
708 	xfs_lsn_t			lsn)
709 {
710 	struct xfs_bud_log_format	*bud_formatp;
711 
712 	bud_formatp = item->ri_buf[0].i_addr;
713 	if (item->ri_buf[0].i_len != sizeof(struct xfs_bud_log_format)) {
714 		XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, log->l_mp,
715 				item->ri_buf[0].i_addr, item->ri_buf[0].i_len);
716 		return -EFSCORRUPTED;
717 	}
718 
719 	xlog_recover_release_intent(log, XFS_LI_BUI, bud_formatp->bud_bui_id);
720 	return 0;
721 }
722 
723 const struct xlog_recover_item_ops xlog_bud_item_ops = {
724 	.item_type		= XFS_LI_BUD,
725 	.commit_pass2		= xlog_recover_bud_commit_pass2,
726 };
727