xref: /linux/fs/xfs/libxfs/xfs_rmap.c (revision 24168c5e6dfbdd5b414f048f47f75d64533296ca)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2014 Red Hat, Inc.
4  * All Rights Reserved.
5  */
6 #include "xfs.h"
7 #include "xfs_fs.h"
8 #include "xfs_shared.h"
9 #include "xfs_format.h"
10 #include "xfs_log_format.h"
11 #include "xfs_trans_resv.h"
12 #include "xfs_bit.h"
13 #include "xfs_mount.h"
14 #include "xfs_sb.h"
15 #include "xfs_defer.h"
16 #include "xfs_btree.h"
17 #include "xfs_trans.h"
18 #include "xfs_alloc.h"
19 #include "xfs_rmap.h"
20 #include "xfs_rmap_btree.h"
21 #include "xfs_trace.h"
22 #include "xfs_errortag.h"
23 #include "xfs_error.h"
24 #include "xfs_inode.h"
25 #include "xfs_ag.h"
26 #include "xfs_health.h"
27 
28 struct kmem_cache	*xfs_rmap_intent_cache;
29 
30 /*
31  * Lookup the first record less than or equal to [bno, len, owner, offset]
32  * in the btree given by cur.
33  */
34 int
35 xfs_rmap_lookup_le(
36 	struct xfs_btree_cur	*cur,
37 	xfs_agblock_t		bno,
38 	uint64_t		owner,
39 	uint64_t		offset,
40 	unsigned int		flags,
41 	struct xfs_rmap_irec	*irec,
42 	int			*stat)
43 {
44 	int			get_stat = 0;
45 	int			error;
46 
47 	cur->bc_rec.r.rm_startblock = bno;
48 	cur->bc_rec.r.rm_blockcount = 0;
49 	cur->bc_rec.r.rm_owner = owner;
50 	cur->bc_rec.r.rm_offset = offset;
51 	cur->bc_rec.r.rm_flags = flags;
52 
53 	error = xfs_btree_lookup(cur, XFS_LOOKUP_LE, stat);
54 	if (error || !(*stat) || !irec)
55 		return error;
56 
57 	error = xfs_rmap_get_rec(cur, irec, &get_stat);
58 	if (error)
59 		return error;
60 	if (!get_stat) {
61 		xfs_btree_mark_sick(cur);
62 		return -EFSCORRUPTED;
63 	}
64 
65 	return 0;
66 }
67 
68 /*
69  * Lookup the record exactly matching [bno, len, owner, offset]
70  * in the btree given by cur.
71  */
72 int
73 xfs_rmap_lookup_eq(
74 	struct xfs_btree_cur	*cur,
75 	xfs_agblock_t		bno,
76 	xfs_extlen_t		len,
77 	uint64_t		owner,
78 	uint64_t		offset,
79 	unsigned int		flags,
80 	int			*stat)
81 {
82 	cur->bc_rec.r.rm_startblock = bno;
83 	cur->bc_rec.r.rm_blockcount = len;
84 	cur->bc_rec.r.rm_owner = owner;
85 	cur->bc_rec.r.rm_offset = offset;
86 	cur->bc_rec.r.rm_flags = flags;
87 	return xfs_btree_lookup(cur, XFS_LOOKUP_EQ, stat);
88 }
89 
90 /*
91  * Update the record referred to by cur to the value given
92  * by [bno, len, owner, offset].
93  * This either works (return 0) or gets an EFSCORRUPTED error.
94  */
95 STATIC int
96 xfs_rmap_update(
97 	struct xfs_btree_cur	*cur,
98 	struct xfs_rmap_irec	*irec)
99 {
100 	union xfs_btree_rec	rec;
101 	int			error;
102 
103 	trace_xfs_rmap_update(cur->bc_mp, cur->bc_ag.pag->pag_agno,
104 			irec->rm_startblock, irec->rm_blockcount,
105 			irec->rm_owner, irec->rm_offset, irec->rm_flags);
106 
107 	rec.rmap.rm_startblock = cpu_to_be32(irec->rm_startblock);
108 	rec.rmap.rm_blockcount = cpu_to_be32(irec->rm_blockcount);
109 	rec.rmap.rm_owner = cpu_to_be64(irec->rm_owner);
110 	rec.rmap.rm_offset = cpu_to_be64(
111 			xfs_rmap_irec_offset_pack(irec));
112 	error = xfs_btree_update(cur, &rec);
113 	if (error)
114 		trace_xfs_rmap_update_error(cur->bc_mp,
115 				cur->bc_ag.pag->pag_agno, error, _RET_IP_);
116 	return error;
117 }
118 
119 int
120 xfs_rmap_insert(
121 	struct xfs_btree_cur	*rcur,
122 	xfs_agblock_t		agbno,
123 	xfs_extlen_t		len,
124 	uint64_t		owner,
125 	uint64_t		offset,
126 	unsigned int		flags)
127 {
128 	int			i;
129 	int			error;
130 
131 	trace_xfs_rmap_insert(rcur->bc_mp, rcur->bc_ag.pag->pag_agno, agbno,
132 			len, owner, offset, flags);
133 
134 	error = xfs_rmap_lookup_eq(rcur, agbno, len, owner, offset, flags, &i);
135 	if (error)
136 		goto done;
137 	if (XFS_IS_CORRUPT(rcur->bc_mp, i != 0)) {
138 		xfs_btree_mark_sick(rcur);
139 		error = -EFSCORRUPTED;
140 		goto done;
141 	}
142 
143 	rcur->bc_rec.r.rm_startblock = agbno;
144 	rcur->bc_rec.r.rm_blockcount = len;
145 	rcur->bc_rec.r.rm_owner = owner;
146 	rcur->bc_rec.r.rm_offset = offset;
147 	rcur->bc_rec.r.rm_flags = flags;
148 	error = xfs_btree_insert(rcur, &i);
149 	if (error)
150 		goto done;
151 	if (XFS_IS_CORRUPT(rcur->bc_mp, i != 1)) {
152 		xfs_btree_mark_sick(rcur);
153 		error = -EFSCORRUPTED;
154 		goto done;
155 	}
156 done:
157 	if (error)
158 		trace_xfs_rmap_insert_error(rcur->bc_mp,
159 				rcur->bc_ag.pag->pag_agno, error, _RET_IP_);
160 	return error;
161 }
162 
163 STATIC int
164 xfs_rmap_delete(
165 	struct xfs_btree_cur	*rcur,
166 	xfs_agblock_t		agbno,
167 	xfs_extlen_t		len,
168 	uint64_t		owner,
169 	uint64_t		offset,
170 	unsigned int		flags)
171 {
172 	int			i;
173 	int			error;
174 
175 	trace_xfs_rmap_delete(rcur->bc_mp, rcur->bc_ag.pag->pag_agno, agbno,
176 			len, owner, offset, flags);
177 
178 	error = xfs_rmap_lookup_eq(rcur, agbno, len, owner, offset, flags, &i);
179 	if (error)
180 		goto done;
181 	if (XFS_IS_CORRUPT(rcur->bc_mp, i != 1)) {
182 		xfs_btree_mark_sick(rcur);
183 		error = -EFSCORRUPTED;
184 		goto done;
185 	}
186 
187 	error = xfs_btree_delete(rcur, &i);
188 	if (error)
189 		goto done;
190 	if (XFS_IS_CORRUPT(rcur->bc_mp, i != 1)) {
191 		xfs_btree_mark_sick(rcur);
192 		error = -EFSCORRUPTED;
193 		goto done;
194 	}
195 done:
196 	if (error)
197 		trace_xfs_rmap_delete_error(rcur->bc_mp,
198 				rcur->bc_ag.pag->pag_agno, error, _RET_IP_);
199 	return error;
200 }
201 
202 /* Convert an internal btree record to an rmap record. */
203 xfs_failaddr_t
204 xfs_rmap_btrec_to_irec(
205 	const union xfs_btree_rec	*rec,
206 	struct xfs_rmap_irec		*irec)
207 {
208 	irec->rm_startblock = be32_to_cpu(rec->rmap.rm_startblock);
209 	irec->rm_blockcount = be32_to_cpu(rec->rmap.rm_blockcount);
210 	irec->rm_owner = be64_to_cpu(rec->rmap.rm_owner);
211 	return xfs_rmap_irec_offset_unpack(be64_to_cpu(rec->rmap.rm_offset),
212 			irec);
213 }
214 
215 /* Simple checks for rmap records. */
216 xfs_failaddr_t
217 xfs_rmap_check_irec(
218 	struct xfs_perag		*pag,
219 	const struct xfs_rmap_irec	*irec)
220 {
221 	struct xfs_mount		*mp = pag->pag_mount;
222 	bool				is_inode;
223 	bool				is_unwritten;
224 	bool				is_bmbt;
225 	bool				is_attr;
226 
227 	if (irec->rm_blockcount == 0)
228 		return __this_address;
229 	if (irec->rm_startblock <= XFS_AGFL_BLOCK(mp)) {
230 		if (irec->rm_owner != XFS_RMAP_OWN_FS)
231 			return __this_address;
232 		if (irec->rm_blockcount != XFS_AGFL_BLOCK(mp) + 1)
233 			return __this_address;
234 	} else {
235 		/* check for valid extent range, including overflow */
236 		if (!xfs_verify_agbext(pag, irec->rm_startblock,
237 					    irec->rm_blockcount))
238 			return __this_address;
239 	}
240 
241 	if (!(xfs_verify_ino(mp, irec->rm_owner) ||
242 	      (irec->rm_owner <= XFS_RMAP_OWN_FS &&
243 	       irec->rm_owner >= XFS_RMAP_OWN_MIN)))
244 		return __this_address;
245 
246 	/* Check flags. */
247 	is_inode = !XFS_RMAP_NON_INODE_OWNER(irec->rm_owner);
248 	is_bmbt = irec->rm_flags & XFS_RMAP_BMBT_BLOCK;
249 	is_attr = irec->rm_flags & XFS_RMAP_ATTR_FORK;
250 	is_unwritten = irec->rm_flags & XFS_RMAP_UNWRITTEN;
251 
252 	if (is_bmbt && irec->rm_offset != 0)
253 		return __this_address;
254 
255 	if (!is_inode && irec->rm_offset != 0)
256 		return __this_address;
257 
258 	if (is_unwritten && (is_bmbt || !is_inode || is_attr))
259 		return __this_address;
260 
261 	if (!is_inode && (is_bmbt || is_unwritten || is_attr))
262 		return __this_address;
263 
264 	/* Check for a valid fork offset, if applicable. */
265 	if (is_inode && !is_bmbt &&
266 	    !xfs_verify_fileext(mp, irec->rm_offset, irec->rm_blockcount))
267 		return __this_address;
268 
269 	return NULL;
270 }
271 
272 static inline xfs_failaddr_t
273 xfs_rmap_check_btrec(
274 	struct xfs_btree_cur		*cur,
275 	const struct xfs_rmap_irec	*irec)
276 {
277 	if (xfs_btree_is_mem_rmap(cur->bc_ops))
278 		return xfs_rmap_check_irec(cur->bc_mem.pag, irec);
279 	return xfs_rmap_check_irec(cur->bc_ag.pag, irec);
280 }
281 
282 static inline int
283 xfs_rmap_complain_bad_rec(
284 	struct xfs_btree_cur		*cur,
285 	xfs_failaddr_t			fa,
286 	const struct xfs_rmap_irec	*irec)
287 {
288 	struct xfs_mount		*mp = cur->bc_mp;
289 
290 	if (xfs_btree_is_mem_rmap(cur->bc_ops))
291 		xfs_warn(mp,
292  "In-Memory Reverse Mapping BTree record corruption detected at %pS!", fa);
293 	else
294 		xfs_warn(mp,
295  "Reverse Mapping BTree record corruption in AG %d detected at %pS!",
296 			cur->bc_ag.pag->pag_agno, fa);
297 	xfs_warn(mp,
298 		"Owner 0x%llx, flags 0x%x, start block 0x%x block count 0x%x",
299 		irec->rm_owner, irec->rm_flags, irec->rm_startblock,
300 		irec->rm_blockcount);
301 	xfs_btree_mark_sick(cur);
302 	return -EFSCORRUPTED;
303 }
304 
305 /*
306  * Get the data from the pointed-to record.
307  */
308 int
309 xfs_rmap_get_rec(
310 	struct xfs_btree_cur	*cur,
311 	struct xfs_rmap_irec	*irec,
312 	int			*stat)
313 {
314 	union xfs_btree_rec	*rec;
315 	xfs_failaddr_t		fa;
316 	int			error;
317 
318 	error = xfs_btree_get_rec(cur, &rec, stat);
319 	if (error || !*stat)
320 		return error;
321 
322 	fa = xfs_rmap_btrec_to_irec(rec, irec);
323 	if (!fa)
324 		fa = xfs_rmap_check_btrec(cur, irec);
325 	if (fa)
326 		return xfs_rmap_complain_bad_rec(cur, fa, irec);
327 
328 	return 0;
329 }
330 
331 struct xfs_find_left_neighbor_info {
332 	struct xfs_rmap_irec	high;
333 	struct xfs_rmap_irec	*irec;
334 };
335 
336 /* For each rmap given, figure out if it matches the key we want. */
337 STATIC int
338 xfs_rmap_find_left_neighbor_helper(
339 	struct xfs_btree_cur		*cur,
340 	const struct xfs_rmap_irec	*rec,
341 	void				*priv)
342 {
343 	struct xfs_find_left_neighbor_info	*info = priv;
344 
345 	trace_xfs_rmap_find_left_neighbor_candidate(cur->bc_mp,
346 			cur->bc_ag.pag->pag_agno, rec->rm_startblock,
347 			rec->rm_blockcount, rec->rm_owner, rec->rm_offset,
348 			rec->rm_flags);
349 
350 	if (rec->rm_owner != info->high.rm_owner)
351 		return 0;
352 	if (!XFS_RMAP_NON_INODE_OWNER(rec->rm_owner) &&
353 	    !(rec->rm_flags & XFS_RMAP_BMBT_BLOCK) &&
354 	    rec->rm_offset + rec->rm_blockcount - 1 != info->high.rm_offset)
355 		return 0;
356 
357 	*info->irec = *rec;
358 	return -ECANCELED;
359 }
360 
361 /*
362  * Find the record to the left of the given extent, being careful only to
363  * return a match with the same owner and adjacent physical and logical
364  * block ranges.
365  */
366 STATIC int
367 xfs_rmap_find_left_neighbor(
368 	struct xfs_btree_cur	*cur,
369 	xfs_agblock_t		bno,
370 	uint64_t		owner,
371 	uint64_t		offset,
372 	unsigned int		flags,
373 	struct xfs_rmap_irec	*irec,
374 	int			*stat)
375 {
376 	struct xfs_find_left_neighbor_info	info;
377 	int			found = 0;
378 	int			error;
379 
380 	*stat = 0;
381 	if (bno == 0)
382 		return 0;
383 	info.high.rm_startblock = bno - 1;
384 	info.high.rm_owner = owner;
385 	if (!XFS_RMAP_NON_INODE_OWNER(owner) &&
386 	    !(flags & XFS_RMAP_BMBT_BLOCK)) {
387 		if (offset == 0)
388 			return 0;
389 		info.high.rm_offset = offset - 1;
390 	} else
391 		info.high.rm_offset = 0;
392 	info.high.rm_flags = flags;
393 	info.high.rm_blockcount = 0;
394 	info.irec = irec;
395 
396 	trace_xfs_rmap_find_left_neighbor_query(cur->bc_mp,
397 			cur->bc_ag.pag->pag_agno, bno, 0, owner, offset, flags);
398 
399 	/*
400 	 * Historically, we always used the range query to walk every reverse
401 	 * mapping that could possibly overlap the key that the caller asked
402 	 * for, and filter out the ones that don't.  That is very slow when
403 	 * there are a lot of records.
404 	 *
405 	 * However, there are two scenarios where the classic btree search can
406 	 * produce correct results -- if the index contains a record that is an
407 	 * exact match for the lookup key; and if there are no other records
408 	 * between the record we want and the key we supplied.
409 	 *
410 	 * As an optimization, try a non-overlapped lookup first.  This makes
411 	 * extent conversion and remap operations run a bit faster if the
412 	 * physical extents aren't being shared.  If we don't find what we
413 	 * want, we fall back to the overlapped query.
414 	 */
415 	error = xfs_rmap_lookup_le(cur, bno, owner, offset, flags, irec,
416 			&found);
417 	if (error)
418 		return error;
419 	if (found)
420 		error = xfs_rmap_find_left_neighbor_helper(cur, irec, &info);
421 	if (!error)
422 		error = xfs_rmap_query_range(cur, &info.high, &info.high,
423 				xfs_rmap_find_left_neighbor_helper, &info);
424 	if (error != -ECANCELED)
425 		return error;
426 
427 	*stat = 1;
428 	trace_xfs_rmap_find_left_neighbor_result(cur->bc_mp,
429 			cur->bc_ag.pag->pag_agno, irec->rm_startblock,
430 			irec->rm_blockcount, irec->rm_owner, irec->rm_offset,
431 			irec->rm_flags);
432 	return 0;
433 }
434 
435 /* For each rmap given, figure out if it matches the key we want. */
436 STATIC int
437 xfs_rmap_lookup_le_range_helper(
438 	struct xfs_btree_cur		*cur,
439 	const struct xfs_rmap_irec	*rec,
440 	void				*priv)
441 {
442 	struct xfs_find_left_neighbor_info	*info = priv;
443 
444 	trace_xfs_rmap_lookup_le_range_candidate(cur->bc_mp,
445 			cur->bc_ag.pag->pag_agno, rec->rm_startblock,
446 			rec->rm_blockcount, rec->rm_owner, rec->rm_offset,
447 			rec->rm_flags);
448 
449 	if (rec->rm_owner != info->high.rm_owner)
450 		return 0;
451 	if (!XFS_RMAP_NON_INODE_OWNER(rec->rm_owner) &&
452 	    !(rec->rm_flags & XFS_RMAP_BMBT_BLOCK) &&
453 	    (rec->rm_offset > info->high.rm_offset ||
454 	     rec->rm_offset + rec->rm_blockcount <= info->high.rm_offset))
455 		return 0;
456 
457 	*info->irec = *rec;
458 	return -ECANCELED;
459 }
460 
461 /*
462  * Find the record to the left of the given extent, being careful only to
463  * return a match with the same owner and overlapping physical and logical
464  * block ranges.  This is the overlapping-interval version of
465  * xfs_rmap_lookup_le.
466  */
467 int
468 xfs_rmap_lookup_le_range(
469 	struct xfs_btree_cur	*cur,
470 	xfs_agblock_t		bno,
471 	uint64_t		owner,
472 	uint64_t		offset,
473 	unsigned int		flags,
474 	struct xfs_rmap_irec	*irec,
475 	int			*stat)
476 {
477 	struct xfs_find_left_neighbor_info	info;
478 	int			found = 0;
479 	int			error;
480 
481 	info.high.rm_startblock = bno;
482 	info.high.rm_owner = owner;
483 	if (!XFS_RMAP_NON_INODE_OWNER(owner) && !(flags & XFS_RMAP_BMBT_BLOCK))
484 		info.high.rm_offset = offset;
485 	else
486 		info.high.rm_offset = 0;
487 	info.high.rm_flags = flags;
488 	info.high.rm_blockcount = 0;
489 	*stat = 0;
490 	info.irec = irec;
491 
492 	trace_xfs_rmap_lookup_le_range(cur->bc_mp, cur->bc_ag.pag->pag_agno,
493 			bno, 0, owner, offset, flags);
494 
495 	/*
496 	 * Historically, we always used the range query to walk every reverse
497 	 * mapping that could possibly overlap the key that the caller asked
498 	 * for, and filter out the ones that don't.  That is very slow when
499 	 * there are a lot of records.
500 	 *
501 	 * However, there are two scenarios where the classic btree search can
502 	 * produce correct results -- if the index contains a record that is an
503 	 * exact match for the lookup key; and if there are no other records
504 	 * between the record we want and the key we supplied.
505 	 *
506 	 * As an optimization, try a non-overlapped lookup first.  This makes
507 	 * scrub run much faster on most filesystems because bmbt records are
508 	 * usually an exact match for rmap records.  If we don't find what we
509 	 * want, we fall back to the overlapped query.
510 	 */
511 	error = xfs_rmap_lookup_le(cur, bno, owner, offset, flags, irec,
512 			&found);
513 	if (error)
514 		return error;
515 	if (found)
516 		error = xfs_rmap_lookup_le_range_helper(cur, irec, &info);
517 	if (!error)
518 		error = xfs_rmap_query_range(cur, &info.high, &info.high,
519 				xfs_rmap_lookup_le_range_helper, &info);
520 	if (error != -ECANCELED)
521 		return error;
522 
523 	*stat = 1;
524 	trace_xfs_rmap_lookup_le_range_result(cur->bc_mp,
525 			cur->bc_ag.pag->pag_agno, irec->rm_startblock,
526 			irec->rm_blockcount, irec->rm_owner, irec->rm_offset,
527 			irec->rm_flags);
528 	return 0;
529 }
530 
531 /*
532  * Perform all the relevant owner checks for a removal op.  If we're doing an
533  * unknown-owner removal then we have no owner information to check.
534  */
535 static int
536 xfs_rmap_free_check_owner(
537 	struct xfs_btree_cur	*cur,
538 	uint64_t		ltoff,
539 	struct xfs_rmap_irec	*rec,
540 	xfs_filblks_t		len,
541 	uint64_t		owner,
542 	uint64_t		offset,
543 	unsigned int		flags)
544 {
545 	struct xfs_mount	*mp = cur->bc_mp;
546 	int			error = 0;
547 
548 	if (owner == XFS_RMAP_OWN_UNKNOWN)
549 		return 0;
550 
551 	/* Make sure the unwritten flag matches. */
552 	if (XFS_IS_CORRUPT(mp,
553 			   (flags & XFS_RMAP_UNWRITTEN) !=
554 			   (rec->rm_flags & XFS_RMAP_UNWRITTEN))) {
555 		xfs_btree_mark_sick(cur);
556 		error = -EFSCORRUPTED;
557 		goto out;
558 	}
559 
560 	/* Make sure the owner matches what we expect to find in the tree. */
561 	if (XFS_IS_CORRUPT(mp, owner != rec->rm_owner)) {
562 		xfs_btree_mark_sick(cur);
563 		error = -EFSCORRUPTED;
564 		goto out;
565 	}
566 
567 	/* Check the offset, if necessary. */
568 	if (XFS_RMAP_NON_INODE_OWNER(owner))
569 		goto out;
570 
571 	if (flags & XFS_RMAP_BMBT_BLOCK) {
572 		if (XFS_IS_CORRUPT(mp,
573 				   !(rec->rm_flags & XFS_RMAP_BMBT_BLOCK))) {
574 			xfs_btree_mark_sick(cur);
575 			error = -EFSCORRUPTED;
576 			goto out;
577 		}
578 	} else {
579 		if (XFS_IS_CORRUPT(mp, rec->rm_offset > offset)) {
580 			xfs_btree_mark_sick(cur);
581 			error = -EFSCORRUPTED;
582 			goto out;
583 		}
584 		if (XFS_IS_CORRUPT(mp,
585 				   offset + len > ltoff + rec->rm_blockcount)) {
586 			xfs_btree_mark_sick(cur);
587 			error = -EFSCORRUPTED;
588 			goto out;
589 		}
590 	}
591 
592 out:
593 	return error;
594 }
595 
596 /*
597  * Find the extent in the rmap btree and remove it.
598  *
599  * The record we find should always be an exact match for the extent that we're
600  * looking for, since we insert them into the btree without modification.
601  *
602  * Special Case #1: when growing the filesystem, we "free" an extent when
603  * growing the last AG. This extent is new space and so it is not tracked as
604  * used space in the btree. The growfs code will pass in an owner of
605  * XFS_RMAP_OWN_NULL to indicate that it expected that there is no owner of this
606  * extent. We verify that - the extent lookup result in a record that does not
607  * overlap.
608  *
609  * Special Case #2: EFIs do not record the owner of the extent, so when
610  * recovering EFIs from the log we pass in XFS_RMAP_OWN_UNKNOWN to tell the rmap
611  * btree to ignore the owner (i.e. wildcard match) so we don't trigger
612  * corruption checks during log recovery.
613  */
614 STATIC int
615 xfs_rmap_unmap(
616 	struct xfs_btree_cur		*cur,
617 	xfs_agblock_t			bno,
618 	xfs_extlen_t			len,
619 	bool				unwritten,
620 	const struct xfs_owner_info	*oinfo)
621 {
622 	struct xfs_mount		*mp = cur->bc_mp;
623 	struct xfs_rmap_irec		ltrec;
624 	uint64_t			ltoff;
625 	int				error = 0;
626 	int				i;
627 	uint64_t			owner;
628 	uint64_t			offset;
629 	unsigned int			flags;
630 	bool				ignore_off;
631 
632 	xfs_owner_info_unpack(oinfo, &owner, &offset, &flags);
633 	ignore_off = XFS_RMAP_NON_INODE_OWNER(owner) ||
634 			(flags & XFS_RMAP_BMBT_BLOCK);
635 	if (unwritten)
636 		flags |= XFS_RMAP_UNWRITTEN;
637 	trace_xfs_rmap_unmap(mp, cur->bc_ag.pag->pag_agno, bno, len,
638 			unwritten, oinfo);
639 
640 	/*
641 	 * We should always have a left record because there's a static record
642 	 * for the AG headers at rm_startblock == 0 created by mkfs/growfs that
643 	 * will not ever be removed from the tree.
644 	 */
645 	error = xfs_rmap_lookup_le(cur, bno, owner, offset, flags, &ltrec, &i);
646 	if (error)
647 		goto out_error;
648 	if (XFS_IS_CORRUPT(mp, i != 1)) {
649 		xfs_btree_mark_sick(cur);
650 		error = -EFSCORRUPTED;
651 		goto out_error;
652 	}
653 
654 	trace_xfs_rmap_lookup_le_range_result(cur->bc_mp,
655 			cur->bc_ag.pag->pag_agno, ltrec.rm_startblock,
656 			ltrec.rm_blockcount, ltrec.rm_owner,
657 			ltrec.rm_offset, ltrec.rm_flags);
658 	ltoff = ltrec.rm_offset;
659 
660 	/*
661 	 * For growfs, the incoming extent must be beyond the left record we
662 	 * just found as it is new space and won't be used by anyone. This is
663 	 * just a corruption check as we don't actually do anything with this
664 	 * extent.  Note that we need to use >= instead of > because it might
665 	 * be the case that the "left" extent goes all the way to EOFS.
666 	 */
667 	if (owner == XFS_RMAP_OWN_NULL) {
668 		if (XFS_IS_CORRUPT(mp,
669 				   bno <
670 				   ltrec.rm_startblock + ltrec.rm_blockcount)) {
671 			xfs_btree_mark_sick(cur);
672 			error = -EFSCORRUPTED;
673 			goto out_error;
674 		}
675 		goto out_done;
676 	}
677 
678 	/*
679 	 * If we're doing an unknown-owner removal for EFI recovery, we expect
680 	 * to find the full range in the rmapbt or nothing at all.  If we
681 	 * don't find any rmaps overlapping either end of the range, we're
682 	 * done.  Hopefully this means that the EFI creator already queued
683 	 * (and finished) a RUI to remove the rmap.
684 	 */
685 	if (owner == XFS_RMAP_OWN_UNKNOWN &&
686 	    ltrec.rm_startblock + ltrec.rm_blockcount <= bno) {
687 		struct xfs_rmap_irec    rtrec;
688 
689 		error = xfs_btree_increment(cur, 0, &i);
690 		if (error)
691 			goto out_error;
692 		if (i == 0)
693 			goto out_done;
694 		error = xfs_rmap_get_rec(cur, &rtrec, &i);
695 		if (error)
696 			goto out_error;
697 		if (XFS_IS_CORRUPT(mp, i != 1)) {
698 			xfs_btree_mark_sick(cur);
699 			error = -EFSCORRUPTED;
700 			goto out_error;
701 		}
702 		if (rtrec.rm_startblock >= bno + len)
703 			goto out_done;
704 	}
705 
706 	/* Make sure the extent we found covers the entire freeing range. */
707 	if (XFS_IS_CORRUPT(mp,
708 			   ltrec.rm_startblock > bno ||
709 			   ltrec.rm_startblock + ltrec.rm_blockcount <
710 			   bno + len)) {
711 		xfs_btree_mark_sick(cur);
712 		error = -EFSCORRUPTED;
713 		goto out_error;
714 	}
715 
716 	/* Check owner information. */
717 	error = xfs_rmap_free_check_owner(cur, ltoff, &ltrec, len, owner,
718 			offset, flags);
719 	if (error)
720 		goto out_error;
721 
722 	if (ltrec.rm_startblock == bno && ltrec.rm_blockcount == len) {
723 		/* exact match, simply remove the record from rmap tree */
724 		trace_xfs_rmap_delete(mp, cur->bc_ag.pag->pag_agno,
725 				ltrec.rm_startblock, ltrec.rm_blockcount,
726 				ltrec.rm_owner, ltrec.rm_offset,
727 				ltrec.rm_flags);
728 		error = xfs_btree_delete(cur, &i);
729 		if (error)
730 			goto out_error;
731 		if (XFS_IS_CORRUPT(mp, i != 1)) {
732 			xfs_btree_mark_sick(cur);
733 			error = -EFSCORRUPTED;
734 			goto out_error;
735 		}
736 	} else if (ltrec.rm_startblock == bno) {
737 		/*
738 		 * overlap left hand side of extent: move the start, trim the
739 		 * length and update the current record.
740 		 *
741 		 *       ltbno                ltlen
742 		 * Orig:    |oooooooooooooooooooo|
743 		 * Freeing: |fffffffff|
744 		 * Result:            |rrrrrrrrrr|
745 		 *         bno       len
746 		 */
747 		ltrec.rm_startblock += len;
748 		ltrec.rm_blockcount -= len;
749 		if (!ignore_off)
750 			ltrec.rm_offset += len;
751 		error = xfs_rmap_update(cur, &ltrec);
752 		if (error)
753 			goto out_error;
754 	} else if (ltrec.rm_startblock + ltrec.rm_blockcount == bno + len) {
755 		/*
756 		 * overlap right hand side of extent: trim the length and update
757 		 * the current record.
758 		 *
759 		 *       ltbno                ltlen
760 		 * Orig:    |oooooooooooooooooooo|
761 		 * Freeing:            |fffffffff|
762 		 * Result:  |rrrrrrrrrr|
763 		 *                    bno       len
764 		 */
765 		ltrec.rm_blockcount -= len;
766 		error = xfs_rmap_update(cur, &ltrec);
767 		if (error)
768 			goto out_error;
769 	} else {
770 
771 		/*
772 		 * overlap middle of extent: trim the length of the existing
773 		 * record to the length of the new left-extent size, increment
774 		 * the insertion position so we can insert a new record
775 		 * containing the remaining right-extent space.
776 		 *
777 		 *       ltbno                ltlen
778 		 * Orig:    |oooooooooooooooooooo|
779 		 * Freeing:       |fffffffff|
780 		 * Result:  |rrrrr|         |rrrr|
781 		 *               bno       len
782 		 */
783 		xfs_extlen_t	orig_len = ltrec.rm_blockcount;
784 
785 		ltrec.rm_blockcount = bno - ltrec.rm_startblock;
786 		error = xfs_rmap_update(cur, &ltrec);
787 		if (error)
788 			goto out_error;
789 
790 		error = xfs_btree_increment(cur, 0, &i);
791 		if (error)
792 			goto out_error;
793 
794 		cur->bc_rec.r.rm_startblock = bno + len;
795 		cur->bc_rec.r.rm_blockcount = orig_len - len -
796 						     ltrec.rm_blockcount;
797 		cur->bc_rec.r.rm_owner = ltrec.rm_owner;
798 		if (ignore_off)
799 			cur->bc_rec.r.rm_offset = 0;
800 		else
801 			cur->bc_rec.r.rm_offset = offset + len;
802 		cur->bc_rec.r.rm_flags = flags;
803 		trace_xfs_rmap_insert(mp, cur->bc_ag.pag->pag_agno,
804 				cur->bc_rec.r.rm_startblock,
805 				cur->bc_rec.r.rm_blockcount,
806 				cur->bc_rec.r.rm_owner,
807 				cur->bc_rec.r.rm_offset,
808 				cur->bc_rec.r.rm_flags);
809 		error = xfs_btree_insert(cur, &i);
810 		if (error)
811 			goto out_error;
812 	}
813 
814 out_done:
815 	trace_xfs_rmap_unmap_done(mp, cur->bc_ag.pag->pag_agno, bno, len,
816 			unwritten, oinfo);
817 out_error:
818 	if (error)
819 		trace_xfs_rmap_unmap_error(mp, cur->bc_ag.pag->pag_agno,
820 				error, _RET_IP_);
821 	return error;
822 }
823 
824 #ifdef CONFIG_XFS_LIVE_HOOKS
825 /*
826  * Use a static key here to reduce the overhead of rmapbt live updates.  If
827  * the compiler supports jump labels, the static branch will be replaced by a
828  * nop sled when there are no hook users.  Online fsck is currently the only
829  * caller, so this is a reasonable tradeoff.
830  *
831  * Note: Patching the kernel code requires taking the cpu hotplug lock.  Other
832  * parts of the kernel allocate memory with that lock held, which means that
833  * XFS callers cannot hold any locks that might be used by memory reclaim or
834  * writeback when calling the static_branch_{inc,dec} functions.
835  */
836 DEFINE_STATIC_XFS_HOOK_SWITCH(xfs_rmap_hooks_switch);
837 
838 void
839 xfs_rmap_hook_disable(void)
840 {
841 	xfs_hooks_switch_off(&xfs_rmap_hooks_switch);
842 }
843 
844 void
845 xfs_rmap_hook_enable(void)
846 {
847 	xfs_hooks_switch_on(&xfs_rmap_hooks_switch);
848 }
849 
850 /* Call downstream hooks for a reverse mapping update. */
851 static inline void
852 xfs_rmap_update_hook(
853 	struct xfs_trans		*tp,
854 	struct xfs_perag		*pag,
855 	enum xfs_rmap_intent_type	op,
856 	xfs_agblock_t			startblock,
857 	xfs_extlen_t			blockcount,
858 	bool				unwritten,
859 	const struct xfs_owner_info	*oinfo)
860 {
861 	if (xfs_hooks_switched_on(&xfs_rmap_hooks_switch)) {
862 		struct xfs_rmap_update_params	p = {
863 			.startblock	= startblock,
864 			.blockcount	= blockcount,
865 			.unwritten	= unwritten,
866 			.oinfo		= *oinfo, /* struct copy */
867 		};
868 
869 		if (pag)
870 			xfs_hooks_call(&pag->pag_rmap_update_hooks, op, &p);
871 	}
872 }
873 
874 /* Call the specified function during a reverse mapping update. */
875 int
876 xfs_rmap_hook_add(
877 	struct xfs_perag	*pag,
878 	struct xfs_rmap_hook	*hook)
879 {
880 	return xfs_hooks_add(&pag->pag_rmap_update_hooks, &hook->rmap_hook);
881 }
882 
883 /* Stop calling the specified function during a reverse mapping update. */
884 void
885 xfs_rmap_hook_del(
886 	struct xfs_perag	*pag,
887 	struct xfs_rmap_hook	*hook)
888 {
889 	xfs_hooks_del(&pag->pag_rmap_update_hooks, &hook->rmap_hook);
890 }
891 
892 /* Configure rmap update hook functions. */
893 void
894 xfs_rmap_hook_setup(
895 	struct xfs_rmap_hook	*hook,
896 	notifier_fn_t		mod_fn)
897 {
898 	xfs_hook_setup(&hook->rmap_hook, mod_fn);
899 }
900 #else
901 # define xfs_rmap_update_hook(t, p, o, s, b, u, oi)	do { } while (0)
902 #endif /* CONFIG_XFS_LIVE_HOOKS */
903 
904 /*
905  * Remove a reference to an extent in the rmap btree.
906  */
907 int
908 xfs_rmap_free(
909 	struct xfs_trans		*tp,
910 	struct xfs_buf			*agbp,
911 	struct xfs_perag		*pag,
912 	xfs_agblock_t			bno,
913 	xfs_extlen_t			len,
914 	const struct xfs_owner_info	*oinfo)
915 {
916 	struct xfs_mount		*mp = tp->t_mountp;
917 	struct xfs_btree_cur		*cur;
918 	int				error;
919 
920 	if (!xfs_has_rmapbt(mp))
921 		return 0;
922 
923 	cur = xfs_rmapbt_init_cursor(mp, tp, agbp, pag);
924 	xfs_rmap_update_hook(tp, pag, XFS_RMAP_UNMAP, bno, len, false, oinfo);
925 	error = xfs_rmap_unmap(cur, bno, len, false, oinfo);
926 
927 	xfs_btree_del_cursor(cur, error);
928 	return error;
929 }
930 
931 /*
932  * A mergeable rmap must have the same owner and the same values for
933  * the unwritten, attr_fork, and bmbt flags.  The startblock and
934  * offset are checked separately.
935  */
936 static bool
937 xfs_rmap_is_mergeable(
938 	struct xfs_rmap_irec	*irec,
939 	uint64_t		owner,
940 	unsigned int		flags)
941 {
942 	if (irec->rm_owner == XFS_RMAP_OWN_NULL)
943 		return false;
944 	if (irec->rm_owner != owner)
945 		return false;
946 	if ((flags & XFS_RMAP_UNWRITTEN) ^
947 	    (irec->rm_flags & XFS_RMAP_UNWRITTEN))
948 		return false;
949 	if ((flags & XFS_RMAP_ATTR_FORK) ^
950 	    (irec->rm_flags & XFS_RMAP_ATTR_FORK))
951 		return false;
952 	if ((flags & XFS_RMAP_BMBT_BLOCK) ^
953 	    (irec->rm_flags & XFS_RMAP_BMBT_BLOCK))
954 		return false;
955 	return true;
956 }
957 
958 /*
959  * When we allocate a new block, the first thing we do is add a reference to
960  * the extent in the rmap btree. This takes the form of a [agbno, length,
961  * owner, offset] record.  Flags are encoded in the high bits of the offset
962  * field.
963  */
964 STATIC int
965 xfs_rmap_map(
966 	struct xfs_btree_cur		*cur,
967 	xfs_agblock_t			bno,
968 	xfs_extlen_t			len,
969 	bool				unwritten,
970 	const struct xfs_owner_info	*oinfo)
971 {
972 	struct xfs_mount		*mp = cur->bc_mp;
973 	struct xfs_rmap_irec		ltrec;
974 	struct xfs_rmap_irec		gtrec;
975 	int				have_gt;
976 	int				have_lt;
977 	int				error = 0;
978 	int				i;
979 	uint64_t			owner;
980 	uint64_t			offset;
981 	unsigned int			flags = 0;
982 	bool				ignore_off;
983 
984 	xfs_owner_info_unpack(oinfo, &owner, &offset, &flags);
985 	ASSERT(owner != 0);
986 	ignore_off = XFS_RMAP_NON_INODE_OWNER(owner) ||
987 			(flags & XFS_RMAP_BMBT_BLOCK);
988 	if (unwritten)
989 		flags |= XFS_RMAP_UNWRITTEN;
990 	trace_xfs_rmap_map(mp, cur->bc_ag.pag->pag_agno, bno, len,
991 			unwritten, oinfo);
992 	ASSERT(!xfs_rmap_should_skip_owner_update(oinfo));
993 
994 	/*
995 	 * For the initial lookup, look for an exact match or the left-adjacent
996 	 * record for our insertion point. This will also give us the record for
997 	 * start block contiguity tests.
998 	 */
999 	error = xfs_rmap_lookup_le(cur, bno, owner, offset, flags, &ltrec,
1000 			&have_lt);
1001 	if (error)
1002 		goto out_error;
1003 	if (have_lt) {
1004 		trace_xfs_rmap_lookup_le_range_result(cur->bc_mp,
1005 				cur->bc_ag.pag->pag_agno, ltrec.rm_startblock,
1006 				ltrec.rm_blockcount, ltrec.rm_owner,
1007 				ltrec.rm_offset, ltrec.rm_flags);
1008 
1009 		if (!xfs_rmap_is_mergeable(&ltrec, owner, flags))
1010 			have_lt = 0;
1011 	}
1012 
1013 	if (XFS_IS_CORRUPT(mp,
1014 			   have_lt != 0 &&
1015 			   ltrec.rm_startblock + ltrec.rm_blockcount > bno)) {
1016 		xfs_btree_mark_sick(cur);
1017 		error = -EFSCORRUPTED;
1018 		goto out_error;
1019 	}
1020 
1021 	/*
1022 	 * Increment the cursor to see if we have a right-adjacent record to our
1023 	 * insertion point. This will give us the record for end block
1024 	 * contiguity tests.
1025 	 */
1026 	error = xfs_btree_increment(cur, 0, &have_gt);
1027 	if (error)
1028 		goto out_error;
1029 	if (have_gt) {
1030 		error = xfs_rmap_get_rec(cur, &gtrec, &have_gt);
1031 		if (error)
1032 			goto out_error;
1033 		if (XFS_IS_CORRUPT(mp, have_gt != 1)) {
1034 			xfs_btree_mark_sick(cur);
1035 			error = -EFSCORRUPTED;
1036 			goto out_error;
1037 		}
1038 		if (XFS_IS_CORRUPT(mp, bno + len > gtrec.rm_startblock)) {
1039 			xfs_btree_mark_sick(cur);
1040 			error = -EFSCORRUPTED;
1041 			goto out_error;
1042 		}
1043 		trace_xfs_rmap_find_right_neighbor_result(cur->bc_mp,
1044 			cur->bc_ag.pag->pag_agno, gtrec.rm_startblock,
1045 			gtrec.rm_blockcount, gtrec.rm_owner,
1046 			gtrec.rm_offset, gtrec.rm_flags);
1047 		if (!xfs_rmap_is_mergeable(&gtrec, owner, flags))
1048 			have_gt = 0;
1049 	}
1050 
1051 	/*
1052 	 * Note: cursor currently points one record to the right of ltrec, even
1053 	 * if there is no record in the tree to the right.
1054 	 */
1055 	if (have_lt &&
1056 	    ltrec.rm_startblock + ltrec.rm_blockcount == bno &&
1057 	    (ignore_off || ltrec.rm_offset + ltrec.rm_blockcount == offset)) {
1058 		/*
1059 		 * left edge contiguous, merge into left record.
1060 		 *
1061 		 *       ltbno     ltlen
1062 		 * orig:   |ooooooooo|
1063 		 * adding:           |aaaaaaaaa|
1064 		 * result: |rrrrrrrrrrrrrrrrrrr|
1065 		 *                  bno       len
1066 		 */
1067 		ltrec.rm_blockcount += len;
1068 		if (have_gt &&
1069 		    bno + len == gtrec.rm_startblock &&
1070 		    (ignore_off || offset + len == gtrec.rm_offset) &&
1071 		    (unsigned long)ltrec.rm_blockcount + len +
1072 				gtrec.rm_blockcount <= XFS_RMAP_LEN_MAX) {
1073 			/*
1074 			 * right edge also contiguous, delete right record
1075 			 * and merge into left record.
1076 			 *
1077 			 *       ltbno     ltlen    gtbno     gtlen
1078 			 * orig:   |ooooooooo|         |ooooooooo|
1079 			 * adding:           |aaaaaaaaa|
1080 			 * result: |rrrrrrrrrrrrrrrrrrrrrrrrrrrrr|
1081 			 */
1082 			ltrec.rm_blockcount += gtrec.rm_blockcount;
1083 			trace_xfs_rmap_delete(mp, cur->bc_ag.pag->pag_agno,
1084 					gtrec.rm_startblock,
1085 					gtrec.rm_blockcount,
1086 					gtrec.rm_owner,
1087 					gtrec.rm_offset,
1088 					gtrec.rm_flags);
1089 			error = xfs_btree_delete(cur, &i);
1090 			if (error)
1091 				goto out_error;
1092 			if (XFS_IS_CORRUPT(mp, i != 1)) {
1093 				xfs_btree_mark_sick(cur);
1094 				error = -EFSCORRUPTED;
1095 				goto out_error;
1096 			}
1097 		}
1098 
1099 		/* point the cursor back to the left record and update */
1100 		error = xfs_btree_decrement(cur, 0, &have_gt);
1101 		if (error)
1102 			goto out_error;
1103 		error = xfs_rmap_update(cur, &ltrec);
1104 		if (error)
1105 			goto out_error;
1106 	} else if (have_gt &&
1107 		   bno + len == gtrec.rm_startblock &&
1108 		   (ignore_off || offset + len == gtrec.rm_offset)) {
1109 		/*
1110 		 * right edge contiguous, merge into right record.
1111 		 *
1112 		 *                 gtbno     gtlen
1113 		 * Orig:             |ooooooooo|
1114 		 * adding: |aaaaaaaaa|
1115 		 * Result: |rrrrrrrrrrrrrrrrrrr|
1116 		 *        bno       len
1117 		 */
1118 		gtrec.rm_startblock = bno;
1119 		gtrec.rm_blockcount += len;
1120 		if (!ignore_off)
1121 			gtrec.rm_offset = offset;
1122 		error = xfs_rmap_update(cur, &gtrec);
1123 		if (error)
1124 			goto out_error;
1125 	} else {
1126 		/*
1127 		 * no contiguous edge with identical owner, insert
1128 		 * new record at current cursor position.
1129 		 */
1130 		cur->bc_rec.r.rm_startblock = bno;
1131 		cur->bc_rec.r.rm_blockcount = len;
1132 		cur->bc_rec.r.rm_owner = owner;
1133 		cur->bc_rec.r.rm_offset = offset;
1134 		cur->bc_rec.r.rm_flags = flags;
1135 		trace_xfs_rmap_insert(mp, cur->bc_ag.pag->pag_agno, bno, len,
1136 			owner, offset, flags);
1137 		error = xfs_btree_insert(cur, &i);
1138 		if (error)
1139 			goto out_error;
1140 		if (XFS_IS_CORRUPT(mp, i != 1)) {
1141 			xfs_btree_mark_sick(cur);
1142 			error = -EFSCORRUPTED;
1143 			goto out_error;
1144 		}
1145 	}
1146 
1147 	trace_xfs_rmap_map_done(mp, cur->bc_ag.pag->pag_agno, bno, len,
1148 			unwritten, oinfo);
1149 out_error:
1150 	if (error)
1151 		trace_xfs_rmap_map_error(mp, cur->bc_ag.pag->pag_agno,
1152 				error, _RET_IP_);
1153 	return error;
1154 }
1155 
1156 /*
1157  * Add a reference to an extent in the rmap btree.
1158  */
1159 int
1160 xfs_rmap_alloc(
1161 	struct xfs_trans		*tp,
1162 	struct xfs_buf			*agbp,
1163 	struct xfs_perag		*pag,
1164 	xfs_agblock_t			bno,
1165 	xfs_extlen_t			len,
1166 	const struct xfs_owner_info	*oinfo)
1167 {
1168 	struct xfs_mount		*mp = tp->t_mountp;
1169 	struct xfs_btree_cur		*cur;
1170 	int				error;
1171 
1172 	if (!xfs_has_rmapbt(mp))
1173 		return 0;
1174 
1175 	cur = xfs_rmapbt_init_cursor(mp, tp, agbp, pag);
1176 	xfs_rmap_update_hook(tp, pag, XFS_RMAP_MAP, bno, len, false, oinfo);
1177 	error = xfs_rmap_map(cur, bno, len, false, oinfo);
1178 
1179 	xfs_btree_del_cursor(cur, error);
1180 	return error;
1181 }
1182 
1183 #define RMAP_LEFT_CONTIG	(1 << 0)
1184 #define RMAP_RIGHT_CONTIG	(1 << 1)
1185 #define RMAP_LEFT_FILLING	(1 << 2)
1186 #define RMAP_RIGHT_FILLING	(1 << 3)
1187 #define RMAP_LEFT_VALID		(1 << 6)
1188 #define RMAP_RIGHT_VALID	(1 << 7)
1189 
1190 #define LEFT		r[0]
1191 #define RIGHT		r[1]
1192 #define PREV		r[2]
1193 #define NEW		r[3]
1194 
1195 /*
1196  * Convert an unwritten extent to a real extent or vice versa.
1197  * Does not handle overlapping extents.
1198  */
1199 STATIC int
1200 xfs_rmap_convert(
1201 	struct xfs_btree_cur		*cur,
1202 	xfs_agblock_t			bno,
1203 	xfs_extlen_t			len,
1204 	bool				unwritten,
1205 	const struct xfs_owner_info	*oinfo)
1206 {
1207 	struct xfs_mount		*mp = cur->bc_mp;
1208 	struct xfs_rmap_irec		r[4];	/* neighbor extent entries */
1209 						/* left is 0, right is 1, */
1210 						/* prev is 2, new is 3 */
1211 	uint64_t		owner;
1212 	uint64_t		offset;
1213 	uint64_t		new_endoff;
1214 	unsigned int		oldext;
1215 	unsigned int		newext;
1216 	unsigned int		flags = 0;
1217 	int			i;
1218 	int			state = 0;
1219 	int			error;
1220 
1221 	xfs_owner_info_unpack(oinfo, &owner, &offset, &flags);
1222 	ASSERT(!(XFS_RMAP_NON_INODE_OWNER(owner) ||
1223 			(flags & (XFS_RMAP_ATTR_FORK | XFS_RMAP_BMBT_BLOCK))));
1224 	oldext = unwritten ? XFS_RMAP_UNWRITTEN : 0;
1225 	new_endoff = offset + len;
1226 	trace_xfs_rmap_convert(mp, cur->bc_ag.pag->pag_agno, bno, len,
1227 			unwritten, oinfo);
1228 
1229 	/*
1230 	 * For the initial lookup, look for an exact match or the left-adjacent
1231 	 * record for our insertion point. This will also give us the record for
1232 	 * start block contiguity tests.
1233 	 */
1234 	error = xfs_rmap_lookup_le(cur, bno, owner, offset, oldext, &PREV, &i);
1235 	if (error)
1236 		goto done;
1237 	if (XFS_IS_CORRUPT(mp, i != 1)) {
1238 		xfs_btree_mark_sick(cur);
1239 		error = -EFSCORRUPTED;
1240 		goto done;
1241 	}
1242 
1243 	trace_xfs_rmap_lookup_le_range_result(cur->bc_mp,
1244 			cur->bc_ag.pag->pag_agno, PREV.rm_startblock,
1245 			PREV.rm_blockcount, PREV.rm_owner,
1246 			PREV.rm_offset, PREV.rm_flags);
1247 
1248 	ASSERT(PREV.rm_offset <= offset);
1249 	ASSERT(PREV.rm_offset + PREV.rm_blockcount >= new_endoff);
1250 	ASSERT((PREV.rm_flags & XFS_RMAP_UNWRITTEN) == oldext);
1251 	newext = ~oldext & XFS_RMAP_UNWRITTEN;
1252 
1253 	/*
1254 	 * Set flags determining what part of the previous oldext allocation
1255 	 * extent is being replaced by a newext allocation.
1256 	 */
1257 	if (PREV.rm_offset == offset)
1258 		state |= RMAP_LEFT_FILLING;
1259 	if (PREV.rm_offset + PREV.rm_blockcount == new_endoff)
1260 		state |= RMAP_RIGHT_FILLING;
1261 
1262 	/*
1263 	 * Decrement the cursor to see if we have a left-adjacent record to our
1264 	 * insertion point. This will give us the record for end block
1265 	 * contiguity tests.
1266 	 */
1267 	error = xfs_btree_decrement(cur, 0, &i);
1268 	if (error)
1269 		goto done;
1270 	if (i) {
1271 		state |= RMAP_LEFT_VALID;
1272 		error = xfs_rmap_get_rec(cur, &LEFT, &i);
1273 		if (error)
1274 			goto done;
1275 		if (XFS_IS_CORRUPT(mp, i != 1)) {
1276 			xfs_btree_mark_sick(cur);
1277 			error = -EFSCORRUPTED;
1278 			goto done;
1279 		}
1280 		if (XFS_IS_CORRUPT(mp,
1281 				   LEFT.rm_startblock + LEFT.rm_blockcount >
1282 				   bno)) {
1283 			xfs_btree_mark_sick(cur);
1284 			error = -EFSCORRUPTED;
1285 			goto done;
1286 		}
1287 		trace_xfs_rmap_find_left_neighbor_result(cur->bc_mp,
1288 				cur->bc_ag.pag->pag_agno, LEFT.rm_startblock,
1289 				LEFT.rm_blockcount, LEFT.rm_owner,
1290 				LEFT.rm_offset, LEFT.rm_flags);
1291 		if (LEFT.rm_startblock + LEFT.rm_blockcount == bno &&
1292 		    LEFT.rm_offset + LEFT.rm_blockcount == offset &&
1293 		    xfs_rmap_is_mergeable(&LEFT, owner, newext))
1294 			state |= RMAP_LEFT_CONTIG;
1295 	}
1296 
1297 	/*
1298 	 * Increment the cursor to see if we have a right-adjacent record to our
1299 	 * insertion point. This will give us the record for end block
1300 	 * contiguity tests.
1301 	 */
1302 	error = xfs_btree_increment(cur, 0, &i);
1303 	if (error)
1304 		goto done;
1305 	if (XFS_IS_CORRUPT(mp, i != 1)) {
1306 		xfs_btree_mark_sick(cur);
1307 		error = -EFSCORRUPTED;
1308 		goto done;
1309 	}
1310 	error = xfs_btree_increment(cur, 0, &i);
1311 	if (error)
1312 		goto done;
1313 	if (i) {
1314 		state |= RMAP_RIGHT_VALID;
1315 		error = xfs_rmap_get_rec(cur, &RIGHT, &i);
1316 		if (error)
1317 			goto done;
1318 		if (XFS_IS_CORRUPT(mp, i != 1)) {
1319 			xfs_btree_mark_sick(cur);
1320 			error = -EFSCORRUPTED;
1321 			goto done;
1322 		}
1323 		if (XFS_IS_CORRUPT(mp, bno + len > RIGHT.rm_startblock)) {
1324 			xfs_btree_mark_sick(cur);
1325 			error = -EFSCORRUPTED;
1326 			goto done;
1327 		}
1328 		trace_xfs_rmap_find_right_neighbor_result(cur->bc_mp,
1329 				cur->bc_ag.pag->pag_agno, RIGHT.rm_startblock,
1330 				RIGHT.rm_blockcount, RIGHT.rm_owner,
1331 				RIGHT.rm_offset, RIGHT.rm_flags);
1332 		if (bno + len == RIGHT.rm_startblock &&
1333 		    offset + len == RIGHT.rm_offset &&
1334 		    xfs_rmap_is_mergeable(&RIGHT, owner, newext))
1335 			state |= RMAP_RIGHT_CONTIG;
1336 	}
1337 
1338 	/* check that left + prev + right is not too long */
1339 	if ((state & (RMAP_LEFT_FILLING | RMAP_LEFT_CONTIG |
1340 			 RMAP_RIGHT_FILLING | RMAP_RIGHT_CONTIG)) ==
1341 	    (RMAP_LEFT_FILLING | RMAP_LEFT_CONTIG |
1342 	     RMAP_RIGHT_FILLING | RMAP_RIGHT_CONTIG) &&
1343 	    (unsigned long)LEFT.rm_blockcount + len +
1344 	     RIGHT.rm_blockcount > XFS_RMAP_LEN_MAX)
1345 		state &= ~RMAP_RIGHT_CONTIG;
1346 
1347 	trace_xfs_rmap_convert_state(mp, cur->bc_ag.pag->pag_agno, state,
1348 			_RET_IP_);
1349 
1350 	/* reset the cursor back to PREV */
1351 	error = xfs_rmap_lookup_le(cur, bno, owner, offset, oldext, NULL, &i);
1352 	if (error)
1353 		goto done;
1354 	if (XFS_IS_CORRUPT(mp, i != 1)) {
1355 		xfs_btree_mark_sick(cur);
1356 		error = -EFSCORRUPTED;
1357 		goto done;
1358 	}
1359 
1360 	/*
1361 	 * Switch out based on the FILLING and CONTIG state bits.
1362 	 */
1363 	switch (state & (RMAP_LEFT_FILLING | RMAP_LEFT_CONTIG |
1364 			 RMAP_RIGHT_FILLING | RMAP_RIGHT_CONTIG)) {
1365 	case RMAP_LEFT_FILLING | RMAP_LEFT_CONTIG |
1366 	     RMAP_RIGHT_FILLING | RMAP_RIGHT_CONTIG:
1367 		/*
1368 		 * Setting all of a previous oldext extent to newext.
1369 		 * The left and right neighbors are both contiguous with new.
1370 		 */
1371 		error = xfs_btree_increment(cur, 0, &i);
1372 		if (error)
1373 			goto done;
1374 		if (XFS_IS_CORRUPT(mp, i != 1)) {
1375 			xfs_btree_mark_sick(cur);
1376 			error = -EFSCORRUPTED;
1377 			goto done;
1378 		}
1379 		trace_xfs_rmap_delete(mp, cur->bc_ag.pag->pag_agno,
1380 				RIGHT.rm_startblock, RIGHT.rm_blockcount,
1381 				RIGHT.rm_owner, RIGHT.rm_offset,
1382 				RIGHT.rm_flags);
1383 		error = xfs_btree_delete(cur, &i);
1384 		if (error)
1385 			goto done;
1386 		if (XFS_IS_CORRUPT(mp, i != 1)) {
1387 			xfs_btree_mark_sick(cur);
1388 			error = -EFSCORRUPTED;
1389 			goto done;
1390 		}
1391 		error = xfs_btree_decrement(cur, 0, &i);
1392 		if (error)
1393 			goto done;
1394 		if (XFS_IS_CORRUPT(mp, i != 1)) {
1395 			xfs_btree_mark_sick(cur);
1396 			error = -EFSCORRUPTED;
1397 			goto done;
1398 		}
1399 		trace_xfs_rmap_delete(mp, cur->bc_ag.pag->pag_agno,
1400 				PREV.rm_startblock, PREV.rm_blockcount,
1401 				PREV.rm_owner, PREV.rm_offset,
1402 				PREV.rm_flags);
1403 		error = xfs_btree_delete(cur, &i);
1404 		if (error)
1405 			goto done;
1406 		if (XFS_IS_CORRUPT(mp, i != 1)) {
1407 			xfs_btree_mark_sick(cur);
1408 			error = -EFSCORRUPTED;
1409 			goto done;
1410 		}
1411 		error = xfs_btree_decrement(cur, 0, &i);
1412 		if (error)
1413 			goto done;
1414 		if (XFS_IS_CORRUPT(mp, i != 1)) {
1415 			xfs_btree_mark_sick(cur);
1416 			error = -EFSCORRUPTED;
1417 			goto done;
1418 		}
1419 		NEW = LEFT;
1420 		NEW.rm_blockcount += PREV.rm_blockcount + RIGHT.rm_blockcount;
1421 		error = xfs_rmap_update(cur, &NEW);
1422 		if (error)
1423 			goto done;
1424 		break;
1425 
1426 	case RMAP_LEFT_FILLING | RMAP_RIGHT_FILLING | RMAP_LEFT_CONTIG:
1427 		/*
1428 		 * Setting all of a previous oldext extent to newext.
1429 		 * The left neighbor is contiguous, the right is not.
1430 		 */
1431 		trace_xfs_rmap_delete(mp, cur->bc_ag.pag->pag_agno,
1432 				PREV.rm_startblock, PREV.rm_blockcount,
1433 				PREV.rm_owner, PREV.rm_offset,
1434 				PREV.rm_flags);
1435 		error = xfs_btree_delete(cur, &i);
1436 		if (error)
1437 			goto done;
1438 		if (XFS_IS_CORRUPT(mp, i != 1)) {
1439 			xfs_btree_mark_sick(cur);
1440 			error = -EFSCORRUPTED;
1441 			goto done;
1442 		}
1443 		error = xfs_btree_decrement(cur, 0, &i);
1444 		if (error)
1445 			goto done;
1446 		if (XFS_IS_CORRUPT(mp, i != 1)) {
1447 			xfs_btree_mark_sick(cur);
1448 			error = -EFSCORRUPTED;
1449 			goto done;
1450 		}
1451 		NEW = LEFT;
1452 		NEW.rm_blockcount += PREV.rm_blockcount;
1453 		error = xfs_rmap_update(cur, &NEW);
1454 		if (error)
1455 			goto done;
1456 		break;
1457 
1458 	case RMAP_LEFT_FILLING | RMAP_RIGHT_FILLING | RMAP_RIGHT_CONTIG:
1459 		/*
1460 		 * Setting all of a previous oldext extent to newext.
1461 		 * The right neighbor is contiguous, the left is not.
1462 		 */
1463 		error = xfs_btree_increment(cur, 0, &i);
1464 		if (error)
1465 			goto done;
1466 		if (XFS_IS_CORRUPT(mp, i != 1)) {
1467 			xfs_btree_mark_sick(cur);
1468 			error = -EFSCORRUPTED;
1469 			goto done;
1470 		}
1471 		trace_xfs_rmap_delete(mp, cur->bc_ag.pag->pag_agno,
1472 				RIGHT.rm_startblock, RIGHT.rm_blockcount,
1473 				RIGHT.rm_owner, RIGHT.rm_offset,
1474 				RIGHT.rm_flags);
1475 		error = xfs_btree_delete(cur, &i);
1476 		if (error)
1477 			goto done;
1478 		if (XFS_IS_CORRUPT(mp, i != 1)) {
1479 			xfs_btree_mark_sick(cur);
1480 			error = -EFSCORRUPTED;
1481 			goto done;
1482 		}
1483 		error = xfs_btree_decrement(cur, 0, &i);
1484 		if (error)
1485 			goto done;
1486 		if (XFS_IS_CORRUPT(mp, i != 1)) {
1487 			xfs_btree_mark_sick(cur);
1488 			error = -EFSCORRUPTED;
1489 			goto done;
1490 		}
1491 		NEW = PREV;
1492 		NEW.rm_blockcount = len + RIGHT.rm_blockcount;
1493 		NEW.rm_flags = newext;
1494 		error = xfs_rmap_update(cur, &NEW);
1495 		if (error)
1496 			goto done;
1497 		break;
1498 
1499 	case RMAP_LEFT_FILLING | RMAP_RIGHT_FILLING:
1500 		/*
1501 		 * Setting all of a previous oldext extent to newext.
1502 		 * Neither the left nor right neighbors are contiguous with
1503 		 * the new one.
1504 		 */
1505 		NEW = PREV;
1506 		NEW.rm_flags = newext;
1507 		error = xfs_rmap_update(cur, &NEW);
1508 		if (error)
1509 			goto done;
1510 		break;
1511 
1512 	case RMAP_LEFT_FILLING | RMAP_LEFT_CONTIG:
1513 		/*
1514 		 * Setting the first part of a previous oldext extent to newext.
1515 		 * The left neighbor is contiguous.
1516 		 */
1517 		NEW = PREV;
1518 		NEW.rm_offset += len;
1519 		NEW.rm_startblock += len;
1520 		NEW.rm_blockcount -= len;
1521 		error = xfs_rmap_update(cur, &NEW);
1522 		if (error)
1523 			goto done;
1524 		error = xfs_btree_decrement(cur, 0, &i);
1525 		if (error)
1526 			goto done;
1527 		NEW = LEFT;
1528 		NEW.rm_blockcount += len;
1529 		error = xfs_rmap_update(cur, &NEW);
1530 		if (error)
1531 			goto done;
1532 		break;
1533 
1534 	case RMAP_LEFT_FILLING:
1535 		/*
1536 		 * Setting the first part of a previous oldext extent to newext.
1537 		 * The left neighbor is not contiguous.
1538 		 */
1539 		NEW = PREV;
1540 		NEW.rm_startblock += len;
1541 		NEW.rm_offset += len;
1542 		NEW.rm_blockcount -= len;
1543 		error = xfs_rmap_update(cur, &NEW);
1544 		if (error)
1545 			goto done;
1546 		NEW.rm_startblock = bno;
1547 		NEW.rm_owner = owner;
1548 		NEW.rm_offset = offset;
1549 		NEW.rm_blockcount = len;
1550 		NEW.rm_flags = newext;
1551 		cur->bc_rec.r = NEW;
1552 		trace_xfs_rmap_insert(mp, cur->bc_ag.pag->pag_agno, bno,
1553 				len, owner, offset, newext);
1554 		error = xfs_btree_insert(cur, &i);
1555 		if (error)
1556 			goto done;
1557 		if (XFS_IS_CORRUPT(mp, i != 1)) {
1558 			xfs_btree_mark_sick(cur);
1559 			error = -EFSCORRUPTED;
1560 			goto done;
1561 		}
1562 		break;
1563 
1564 	case RMAP_RIGHT_FILLING | RMAP_RIGHT_CONTIG:
1565 		/*
1566 		 * Setting the last part of a previous oldext extent to newext.
1567 		 * The right neighbor is contiguous with the new allocation.
1568 		 */
1569 		NEW = PREV;
1570 		NEW.rm_blockcount -= len;
1571 		error = xfs_rmap_update(cur, &NEW);
1572 		if (error)
1573 			goto done;
1574 		error = xfs_btree_increment(cur, 0, &i);
1575 		if (error)
1576 			goto done;
1577 		NEW = RIGHT;
1578 		NEW.rm_offset = offset;
1579 		NEW.rm_startblock = bno;
1580 		NEW.rm_blockcount += len;
1581 		error = xfs_rmap_update(cur, &NEW);
1582 		if (error)
1583 			goto done;
1584 		break;
1585 
1586 	case RMAP_RIGHT_FILLING:
1587 		/*
1588 		 * Setting the last part of a previous oldext extent to newext.
1589 		 * The right neighbor is not contiguous.
1590 		 */
1591 		NEW = PREV;
1592 		NEW.rm_blockcount -= len;
1593 		error = xfs_rmap_update(cur, &NEW);
1594 		if (error)
1595 			goto done;
1596 		error = xfs_rmap_lookup_eq(cur, bno, len, owner, offset,
1597 				oldext, &i);
1598 		if (error)
1599 			goto done;
1600 		if (XFS_IS_CORRUPT(mp, i != 0)) {
1601 			xfs_btree_mark_sick(cur);
1602 			error = -EFSCORRUPTED;
1603 			goto done;
1604 		}
1605 		NEW.rm_startblock = bno;
1606 		NEW.rm_owner = owner;
1607 		NEW.rm_offset = offset;
1608 		NEW.rm_blockcount = len;
1609 		NEW.rm_flags = newext;
1610 		cur->bc_rec.r = NEW;
1611 		trace_xfs_rmap_insert(mp, cur->bc_ag.pag->pag_agno, bno,
1612 				len, owner, offset, newext);
1613 		error = xfs_btree_insert(cur, &i);
1614 		if (error)
1615 			goto done;
1616 		if (XFS_IS_CORRUPT(mp, i != 1)) {
1617 			xfs_btree_mark_sick(cur);
1618 			error = -EFSCORRUPTED;
1619 			goto done;
1620 		}
1621 		break;
1622 
1623 	case 0:
1624 		/*
1625 		 * Setting the middle part of a previous oldext extent to
1626 		 * newext.  Contiguity is impossible here.
1627 		 * One extent becomes three extents.
1628 		 */
1629 		/* new right extent - oldext */
1630 		NEW.rm_startblock = bno + len;
1631 		NEW.rm_owner = owner;
1632 		NEW.rm_offset = new_endoff;
1633 		NEW.rm_blockcount = PREV.rm_offset + PREV.rm_blockcount -
1634 				new_endoff;
1635 		NEW.rm_flags = PREV.rm_flags;
1636 		error = xfs_rmap_update(cur, &NEW);
1637 		if (error)
1638 			goto done;
1639 		/* new left extent - oldext */
1640 		NEW = PREV;
1641 		NEW.rm_blockcount = offset - PREV.rm_offset;
1642 		cur->bc_rec.r = NEW;
1643 		trace_xfs_rmap_insert(mp, cur->bc_ag.pag->pag_agno,
1644 				NEW.rm_startblock, NEW.rm_blockcount,
1645 				NEW.rm_owner, NEW.rm_offset,
1646 				NEW.rm_flags);
1647 		error = xfs_btree_insert(cur, &i);
1648 		if (error)
1649 			goto done;
1650 		if (XFS_IS_CORRUPT(mp, i != 1)) {
1651 			xfs_btree_mark_sick(cur);
1652 			error = -EFSCORRUPTED;
1653 			goto done;
1654 		}
1655 		/*
1656 		 * Reset the cursor to the position of the new extent
1657 		 * we are about to insert as we can't trust it after
1658 		 * the previous insert.
1659 		 */
1660 		error = xfs_rmap_lookup_eq(cur, bno, len, owner, offset,
1661 				oldext, &i);
1662 		if (error)
1663 			goto done;
1664 		if (XFS_IS_CORRUPT(mp, i != 0)) {
1665 			xfs_btree_mark_sick(cur);
1666 			error = -EFSCORRUPTED;
1667 			goto done;
1668 		}
1669 		/* new middle extent - newext */
1670 		cur->bc_rec.r.rm_flags &= ~XFS_RMAP_UNWRITTEN;
1671 		cur->bc_rec.r.rm_flags |= newext;
1672 		trace_xfs_rmap_insert(mp, cur->bc_ag.pag->pag_agno, bno, len,
1673 				owner, offset, newext);
1674 		error = xfs_btree_insert(cur, &i);
1675 		if (error)
1676 			goto done;
1677 		if (XFS_IS_CORRUPT(mp, i != 1)) {
1678 			xfs_btree_mark_sick(cur);
1679 			error = -EFSCORRUPTED;
1680 			goto done;
1681 		}
1682 		break;
1683 
1684 	case RMAP_LEFT_FILLING | RMAP_LEFT_CONTIG | RMAP_RIGHT_CONTIG:
1685 	case RMAP_RIGHT_FILLING | RMAP_LEFT_CONTIG | RMAP_RIGHT_CONTIG:
1686 	case RMAP_LEFT_FILLING | RMAP_RIGHT_CONTIG:
1687 	case RMAP_RIGHT_FILLING | RMAP_LEFT_CONTIG:
1688 	case RMAP_LEFT_CONTIG | RMAP_RIGHT_CONTIG:
1689 	case RMAP_LEFT_CONTIG:
1690 	case RMAP_RIGHT_CONTIG:
1691 		/*
1692 		 * These cases are all impossible.
1693 		 */
1694 		ASSERT(0);
1695 	}
1696 
1697 	trace_xfs_rmap_convert_done(mp, cur->bc_ag.pag->pag_agno, bno, len,
1698 			unwritten, oinfo);
1699 done:
1700 	if (error)
1701 		trace_xfs_rmap_convert_error(cur->bc_mp,
1702 				cur->bc_ag.pag->pag_agno, error, _RET_IP_);
1703 	return error;
1704 }
1705 
1706 /*
1707  * Convert an unwritten extent to a real extent or vice versa.  If there is no
1708  * possibility of overlapping extents, delegate to the simpler convert
1709  * function.
1710  */
1711 STATIC int
1712 xfs_rmap_convert_shared(
1713 	struct xfs_btree_cur		*cur,
1714 	xfs_agblock_t			bno,
1715 	xfs_extlen_t			len,
1716 	bool				unwritten,
1717 	const struct xfs_owner_info	*oinfo)
1718 {
1719 	struct xfs_mount		*mp = cur->bc_mp;
1720 	struct xfs_rmap_irec		r[4];	/* neighbor extent entries */
1721 						/* left is 0, right is 1, */
1722 						/* prev is 2, new is 3 */
1723 	uint64_t		owner;
1724 	uint64_t		offset;
1725 	uint64_t		new_endoff;
1726 	unsigned int		oldext;
1727 	unsigned int		newext;
1728 	unsigned int		flags = 0;
1729 	int			i;
1730 	int			state = 0;
1731 	int			error;
1732 
1733 	xfs_owner_info_unpack(oinfo, &owner, &offset, &flags);
1734 	ASSERT(!(XFS_RMAP_NON_INODE_OWNER(owner) ||
1735 			(flags & (XFS_RMAP_ATTR_FORK | XFS_RMAP_BMBT_BLOCK))));
1736 	oldext = unwritten ? XFS_RMAP_UNWRITTEN : 0;
1737 	new_endoff = offset + len;
1738 	trace_xfs_rmap_convert(mp, cur->bc_ag.pag->pag_agno, bno, len,
1739 			unwritten, oinfo);
1740 
1741 	/*
1742 	 * For the initial lookup, look for and exact match or the left-adjacent
1743 	 * record for our insertion point. This will also give us the record for
1744 	 * start block contiguity tests.
1745 	 */
1746 	error = xfs_rmap_lookup_le_range(cur, bno, owner, offset, oldext,
1747 			&PREV, &i);
1748 	if (error)
1749 		goto done;
1750 	if (XFS_IS_CORRUPT(mp, i != 1)) {
1751 		xfs_btree_mark_sick(cur);
1752 		error = -EFSCORRUPTED;
1753 		goto done;
1754 	}
1755 
1756 	ASSERT(PREV.rm_offset <= offset);
1757 	ASSERT(PREV.rm_offset + PREV.rm_blockcount >= new_endoff);
1758 	ASSERT((PREV.rm_flags & XFS_RMAP_UNWRITTEN) == oldext);
1759 	newext = ~oldext & XFS_RMAP_UNWRITTEN;
1760 
1761 	/*
1762 	 * Set flags determining what part of the previous oldext allocation
1763 	 * extent is being replaced by a newext allocation.
1764 	 */
1765 	if (PREV.rm_offset == offset)
1766 		state |= RMAP_LEFT_FILLING;
1767 	if (PREV.rm_offset + PREV.rm_blockcount == new_endoff)
1768 		state |= RMAP_RIGHT_FILLING;
1769 
1770 	/* Is there a left record that abuts our range? */
1771 	error = xfs_rmap_find_left_neighbor(cur, bno, owner, offset, newext,
1772 			&LEFT, &i);
1773 	if (error)
1774 		goto done;
1775 	if (i) {
1776 		state |= RMAP_LEFT_VALID;
1777 		if (XFS_IS_CORRUPT(mp,
1778 				   LEFT.rm_startblock + LEFT.rm_blockcount >
1779 				   bno)) {
1780 			xfs_btree_mark_sick(cur);
1781 			error = -EFSCORRUPTED;
1782 			goto done;
1783 		}
1784 		if (xfs_rmap_is_mergeable(&LEFT, owner, newext))
1785 			state |= RMAP_LEFT_CONTIG;
1786 	}
1787 
1788 	/* Is there a right record that abuts our range? */
1789 	error = xfs_rmap_lookup_eq(cur, bno + len, len, owner, offset + len,
1790 			newext, &i);
1791 	if (error)
1792 		goto done;
1793 	if (i) {
1794 		state |= RMAP_RIGHT_VALID;
1795 		error = xfs_rmap_get_rec(cur, &RIGHT, &i);
1796 		if (error)
1797 			goto done;
1798 		if (XFS_IS_CORRUPT(mp, i != 1)) {
1799 			xfs_btree_mark_sick(cur);
1800 			error = -EFSCORRUPTED;
1801 			goto done;
1802 		}
1803 		if (XFS_IS_CORRUPT(mp, bno + len > RIGHT.rm_startblock)) {
1804 			xfs_btree_mark_sick(cur);
1805 			error = -EFSCORRUPTED;
1806 			goto done;
1807 		}
1808 		trace_xfs_rmap_find_right_neighbor_result(cur->bc_mp,
1809 				cur->bc_ag.pag->pag_agno, RIGHT.rm_startblock,
1810 				RIGHT.rm_blockcount, RIGHT.rm_owner,
1811 				RIGHT.rm_offset, RIGHT.rm_flags);
1812 		if (xfs_rmap_is_mergeable(&RIGHT, owner, newext))
1813 			state |= RMAP_RIGHT_CONTIG;
1814 	}
1815 
1816 	/* check that left + prev + right is not too long */
1817 	if ((state & (RMAP_LEFT_FILLING | RMAP_LEFT_CONTIG |
1818 			 RMAP_RIGHT_FILLING | RMAP_RIGHT_CONTIG)) ==
1819 	    (RMAP_LEFT_FILLING | RMAP_LEFT_CONTIG |
1820 	     RMAP_RIGHT_FILLING | RMAP_RIGHT_CONTIG) &&
1821 	    (unsigned long)LEFT.rm_blockcount + len +
1822 	     RIGHT.rm_blockcount > XFS_RMAP_LEN_MAX)
1823 		state &= ~RMAP_RIGHT_CONTIG;
1824 
1825 	trace_xfs_rmap_convert_state(mp, cur->bc_ag.pag->pag_agno, state,
1826 			_RET_IP_);
1827 	/*
1828 	 * Switch out based on the FILLING and CONTIG state bits.
1829 	 */
1830 	switch (state & (RMAP_LEFT_FILLING | RMAP_LEFT_CONTIG |
1831 			 RMAP_RIGHT_FILLING | RMAP_RIGHT_CONTIG)) {
1832 	case RMAP_LEFT_FILLING | RMAP_LEFT_CONTIG |
1833 	     RMAP_RIGHT_FILLING | RMAP_RIGHT_CONTIG:
1834 		/*
1835 		 * Setting all of a previous oldext extent to newext.
1836 		 * The left and right neighbors are both contiguous with new.
1837 		 */
1838 		error = xfs_rmap_delete(cur, RIGHT.rm_startblock,
1839 				RIGHT.rm_blockcount, RIGHT.rm_owner,
1840 				RIGHT.rm_offset, RIGHT.rm_flags);
1841 		if (error)
1842 			goto done;
1843 		error = xfs_rmap_delete(cur, PREV.rm_startblock,
1844 				PREV.rm_blockcount, PREV.rm_owner,
1845 				PREV.rm_offset, PREV.rm_flags);
1846 		if (error)
1847 			goto done;
1848 		NEW = LEFT;
1849 		error = xfs_rmap_lookup_eq(cur, NEW.rm_startblock,
1850 				NEW.rm_blockcount, NEW.rm_owner,
1851 				NEW.rm_offset, NEW.rm_flags, &i);
1852 		if (error)
1853 			goto done;
1854 		if (XFS_IS_CORRUPT(mp, i != 1)) {
1855 			xfs_btree_mark_sick(cur);
1856 			error = -EFSCORRUPTED;
1857 			goto done;
1858 		}
1859 		NEW.rm_blockcount += PREV.rm_blockcount + RIGHT.rm_blockcount;
1860 		error = xfs_rmap_update(cur, &NEW);
1861 		if (error)
1862 			goto done;
1863 		break;
1864 
1865 	case RMAP_LEFT_FILLING | RMAP_RIGHT_FILLING | RMAP_LEFT_CONTIG:
1866 		/*
1867 		 * Setting all of a previous oldext extent to newext.
1868 		 * The left neighbor is contiguous, the right is not.
1869 		 */
1870 		error = xfs_rmap_delete(cur, PREV.rm_startblock,
1871 				PREV.rm_blockcount, PREV.rm_owner,
1872 				PREV.rm_offset, PREV.rm_flags);
1873 		if (error)
1874 			goto done;
1875 		NEW = LEFT;
1876 		error = xfs_rmap_lookup_eq(cur, NEW.rm_startblock,
1877 				NEW.rm_blockcount, NEW.rm_owner,
1878 				NEW.rm_offset, NEW.rm_flags, &i);
1879 		if (error)
1880 			goto done;
1881 		if (XFS_IS_CORRUPT(mp, i != 1)) {
1882 			xfs_btree_mark_sick(cur);
1883 			error = -EFSCORRUPTED;
1884 			goto done;
1885 		}
1886 		NEW.rm_blockcount += PREV.rm_blockcount;
1887 		error = xfs_rmap_update(cur, &NEW);
1888 		if (error)
1889 			goto done;
1890 		break;
1891 
1892 	case RMAP_LEFT_FILLING | RMAP_RIGHT_FILLING | RMAP_RIGHT_CONTIG:
1893 		/*
1894 		 * Setting all of a previous oldext extent to newext.
1895 		 * The right neighbor is contiguous, the left is not.
1896 		 */
1897 		error = xfs_rmap_delete(cur, RIGHT.rm_startblock,
1898 				RIGHT.rm_blockcount, RIGHT.rm_owner,
1899 				RIGHT.rm_offset, RIGHT.rm_flags);
1900 		if (error)
1901 			goto done;
1902 		NEW = PREV;
1903 		error = xfs_rmap_lookup_eq(cur, NEW.rm_startblock,
1904 				NEW.rm_blockcount, NEW.rm_owner,
1905 				NEW.rm_offset, NEW.rm_flags, &i);
1906 		if (error)
1907 			goto done;
1908 		if (XFS_IS_CORRUPT(mp, i != 1)) {
1909 			xfs_btree_mark_sick(cur);
1910 			error = -EFSCORRUPTED;
1911 			goto done;
1912 		}
1913 		NEW.rm_blockcount += RIGHT.rm_blockcount;
1914 		NEW.rm_flags = RIGHT.rm_flags;
1915 		error = xfs_rmap_update(cur, &NEW);
1916 		if (error)
1917 			goto done;
1918 		break;
1919 
1920 	case RMAP_LEFT_FILLING | RMAP_RIGHT_FILLING:
1921 		/*
1922 		 * Setting all of a previous oldext extent to newext.
1923 		 * Neither the left nor right neighbors are contiguous with
1924 		 * the new one.
1925 		 */
1926 		NEW = PREV;
1927 		error = xfs_rmap_lookup_eq(cur, NEW.rm_startblock,
1928 				NEW.rm_blockcount, NEW.rm_owner,
1929 				NEW.rm_offset, NEW.rm_flags, &i);
1930 		if (error)
1931 			goto done;
1932 		if (XFS_IS_CORRUPT(mp, i != 1)) {
1933 			xfs_btree_mark_sick(cur);
1934 			error = -EFSCORRUPTED;
1935 			goto done;
1936 		}
1937 		NEW.rm_flags = newext;
1938 		error = xfs_rmap_update(cur, &NEW);
1939 		if (error)
1940 			goto done;
1941 		break;
1942 
1943 	case RMAP_LEFT_FILLING | RMAP_LEFT_CONTIG:
1944 		/*
1945 		 * Setting the first part of a previous oldext extent to newext.
1946 		 * The left neighbor is contiguous.
1947 		 */
1948 		NEW = PREV;
1949 		error = xfs_rmap_delete(cur, NEW.rm_startblock,
1950 				NEW.rm_blockcount, NEW.rm_owner,
1951 				NEW.rm_offset, NEW.rm_flags);
1952 		if (error)
1953 			goto done;
1954 		NEW.rm_offset += len;
1955 		NEW.rm_startblock += len;
1956 		NEW.rm_blockcount -= len;
1957 		error = xfs_rmap_insert(cur, NEW.rm_startblock,
1958 				NEW.rm_blockcount, NEW.rm_owner,
1959 				NEW.rm_offset, NEW.rm_flags);
1960 		if (error)
1961 			goto done;
1962 		NEW = LEFT;
1963 		error = xfs_rmap_lookup_eq(cur, NEW.rm_startblock,
1964 				NEW.rm_blockcount, NEW.rm_owner,
1965 				NEW.rm_offset, NEW.rm_flags, &i);
1966 		if (error)
1967 			goto done;
1968 		if (XFS_IS_CORRUPT(mp, i != 1)) {
1969 			xfs_btree_mark_sick(cur);
1970 			error = -EFSCORRUPTED;
1971 			goto done;
1972 		}
1973 		NEW.rm_blockcount += len;
1974 		error = xfs_rmap_update(cur, &NEW);
1975 		if (error)
1976 			goto done;
1977 		break;
1978 
1979 	case RMAP_LEFT_FILLING:
1980 		/*
1981 		 * Setting the first part of a previous oldext extent to newext.
1982 		 * The left neighbor is not contiguous.
1983 		 */
1984 		NEW = PREV;
1985 		error = xfs_rmap_delete(cur, NEW.rm_startblock,
1986 				NEW.rm_blockcount, NEW.rm_owner,
1987 				NEW.rm_offset, NEW.rm_flags);
1988 		if (error)
1989 			goto done;
1990 		NEW.rm_offset += len;
1991 		NEW.rm_startblock += len;
1992 		NEW.rm_blockcount -= len;
1993 		error = xfs_rmap_insert(cur, NEW.rm_startblock,
1994 				NEW.rm_blockcount, NEW.rm_owner,
1995 				NEW.rm_offset, NEW.rm_flags);
1996 		if (error)
1997 			goto done;
1998 		error = xfs_rmap_insert(cur, bno, len, owner, offset, newext);
1999 		if (error)
2000 			goto done;
2001 		break;
2002 
2003 	case RMAP_RIGHT_FILLING | RMAP_RIGHT_CONTIG:
2004 		/*
2005 		 * Setting the last part of a previous oldext extent to newext.
2006 		 * The right neighbor is contiguous with the new allocation.
2007 		 */
2008 		NEW = PREV;
2009 		error = xfs_rmap_lookup_eq(cur, NEW.rm_startblock,
2010 				NEW.rm_blockcount, NEW.rm_owner,
2011 				NEW.rm_offset, NEW.rm_flags, &i);
2012 		if (error)
2013 			goto done;
2014 		if (XFS_IS_CORRUPT(mp, i != 1)) {
2015 			xfs_btree_mark_sick(cur);
2016 			error = -EFSCORRUPTED;
2017 			goto done;
2018 		}
2019 		NEW.rm_blockcount = offset - NEW.rm_offset;
2020 		error = xfs_rmap_update(cur, &NEW);
2021 		if (error)
2022 			goto done;
2023 		NEW = RIGHT;
2024 		error = xfs_rmap_delete(cur, NEW.rm_startblock,
2025 				NEW.rm_blockcount, NEW.rm_owner,
2026 				NEW.rm_offset, NEW.rm_flags);
2027 		if (error)
2028 			goto done;
2029 		NEW.rm_offset = offset;
2030 		NEW.rm_startblock = bno;
2031 		NEW.rm_blockcount += len;
2032 		error = xfs_rmap_insert(cur, NEW.rm_startblock,
2033 				NEW.rm_blockcount, NEW.rm_owner,
2034 				NEW.rm_offset, NEW.rm_flags);
2035 		if (error)
2036 			goto done;
2037 		break;
2038 
2039 	case RMAP_RIGHT_FILLING:
2040 		/*
2041 		 * Setting the last part of a previous oldext extent to newext.
2042 		 * The right neighbor is not contiguous.
2043 		 */
2044 		NEW = PREV;
2045 		error = xfs_rmap_lookup_eq(cur, NEW.rm_startblock,
2046 				NEW.rm_blockcount, NEW.rm_owner,
2047 				NEW.rm_offset, NEW.rm_flags, &i);
2048 		if (error)
2049 			goto done;
2050 		if (XFS_IS_CORRUPT(mp, i != 1)) {
2051 			xfs_btree_mark_sick(cur);
2052 			error = -EFSCORRUPTED;
2053 			goto done;
2054 		}
2055 		NEW.rm_blockcount -= len;
2056 		error = xfs_rmap_update(cur, &NEW);
2057 		if (error)
2058 			goto done;
2059 		error = xfs_rmap_insert(cur, bno, len, owner, offset, newext);
2060 		if (error)
2061 			goto done;
2062 		break;
2063 
2064 	case 0:
2065 		/*
2066 		 * Setting the middle part of a previous oldext extent to
2067 		 * newext.  Contiguity is impossible here.
2068 		 * One extent becomes three extents.
2069 		 */
2070 		/* new right extent - oldext */
2071 		NEW.rm_startblock = bno + len;
2072 		NEW.rm_owner = owner;
2073 		NEW.rm_offset = new_endoff;
2074 		NEW.rm_blockcount = PREV.rm_offset + PREV.rm_blockcount -
2075 				new_endoff;
2076 		NEW.rm_flags = PREV.rm_flags;
2077 		error = xfs_rmap_insert(cur, NEW.rm_startblock,
2078 				NEW.rm_blockcount, NEW.rm_owner, NEW.rm_offset,
2079 				NEW.rm_flags);
2080 		if (error)
2081 			goto done;
2082 		/* new left extent - oldext */
2083 		NEW = PREV;
2084 		error = xfs_rmap_lookup_eq(cur, NEW.rm_startblock,
2085 				NEW.rm_blockcount, NEW.rm_owner,
2086 				NEW.rm_offset, NEW.rm_flags, &i);
2087 		if (error)
2088 			goto done;
2089 		if (XFS_IS_CORRUPT(mp, i != 1)) {
2090 			xfs_btree_mark_sick(cur);
2091 			error = -EFSCORRUPTED;
2092 			goto done;
2093 		}
2094 		NEW.rm_blockcount = offset - NEW.rm_offset;
2095 		error = xfs_rmap_update(cur, &NEW);
2096 		if (error)
2097 			goto done;
2098 		/* new middle extent - newext */
2099 		NEW.rm_startblock = bno;
2100 		NEW.rm_blockcount = len;
2101 		NEW.rm_owner = owner;
2102 		NEW.rm_offset = offset;
2103 		NEW.rm_flags = newext;
2104 		error = xfs_rmap_insert(cur, NEW.rm_startblock,
2105 				NEW.rm_blockcount, NEW.rm_owner, NEW.rm_offset,
2106 				NEW.rm_flags);
2107 		if (error)
2108 			goto done;
2109 		break;
2110 
2111 	case RMAP_LEFT_FILLING | RMAP_LEFT_CONTIG | RMAP_RIGHT_CONTIG:
2112 	case RMAP_RIGHT_FILLING | RMAP_LEFT_CONTIG | RMAP_RIGHT_CONTIG:
2113 	case RMAP_LEFT_FILLING | RMAP_RIGHT_CONTIG:
2114 	case RMAP_RIGHT_FILLING | RMAP_LEFT_CONTIG:
2115 	case RMAP_LEFT_CONTIG | RMAP_RIGHT_CONTIG:
2116 	case RMAP_LEFT_CONTIG:
2117 	case RMAP_RIGHT_CONTIG:
2118 		/*
2119 		 * These cases are all impossible.
2120 		 */
2121 		ASSERT(0);
2122 	}
2123 
2124 	trace_xfs_rmap_convert_done(mp, cur->bc_ag.pag->pag_agno, bno, len,
2125 			unwritten, oinfo);
2126 done:
2127 	if (error)
2128 		trace_xfs_rmap_convert_error(cur->bc_mp,
2129 				cur->bc_ag.pag->pag_agno, error, _RET_IP_);
2130 	return error;
2131 }
2132 
2133 #undef	NEW
2134 #undef	LEFT
2135 #undef	RIGHT
2136 #undef	PREV
2137 
2138 /*
2139  * Find an extent in the rmap btree and unmap it.  For rmap extent types that
2140  * can overlap (data fork rmaps on reflink filesystems) we must be careful
2141  * that the prev/next records in the btree might belong to another owner.
2142  * Therefore we must use delete+insert to alter any of the key fields.
2143  *
2144  * For every other situation there can only be one owner for a given extent,
2145  * so we can call the regular _free function.
2146  */
2147 STATIC int
2148 xfs_rmap_unmap_shared(
2149 	struct xfs_btree_cur		*cur,
2150 	xfs_agblock_t			bno,
2151 	xfs_extlen_t			len,
2152 	bool				unwritten,
2153 	const struct xfs_owner_info	*oinfo)
2154 {
2155 	struct xfs_mount		*mp = cur->bc_mp;
2156 	struct xfs_rmap_irec		ltrec;
2157 	uint64_t			ltoff;
2158 	int				error = 0;
2159 	int				i;
2160 	uint64_t			owner;
2161 	uint64_t			offset;
2162 	unsigned int			flags;
2163 
2164 	xfs_owner_info_unpack(oinfo, &owner, &offset, &flags);
2165 	if (unwritten)
2166 		flags |= XFS_RMAP_UNWRITTEN;
2167 	trace_xfs_rmap_unmap(mp, cur->bc_ag.pag->pag_agno, bno, len,
2168 			unwritten, oinfo);
2169 
2170 	/*
2171 	 * We should always have a left record because there's a static record
2172 	 * for the AG headers at rm_startblock == 0 created by mkfs/growfs that
2173 	 * will not ever be removed from the tree.
2174 	 */
2175 	error = xfs_rmap_lookup_le_range(cur, bno, owner, offset, flags,
2176 			&ltrec, &i);
2177 	if (error)
2178 		goto out_error;
2179 	if (XFS_IS_CORRUPT(mp, i != 1)) {
2180 		xfs_btree_mark_sick(cur);
2181 		error = -EFSCORRUPTED;
2182 		goto out_error;
2183 	}
2184 	ltoff = ltrec.rm_offset;
2185 
2186 	/* Make sure the extent we found covers the entire freeing range. */
2187 	if (XFS_IS_CORRUPT(mp,
2188 			   ltrec.rm_startblock > bno ||
2189 			   ltrec.rm_startblock + ltrec.rm_blockcount <
2190 			   bno + len)) {
2191 		xfs_btree_mark_sick(cur);
2192 		error = -EFSCORRUPTED;
2193 		goto out_error;
2194 	}
2195 
2196 	/* Make sure the owner matches what we expect to find in the tree. */
2197 	if (XFS_IS_CORRUPT(mp, owner != ltrec.rm_owner)) {
2198 		xfs_btree_mark_sick(cur);
2199 		error = -EFSCORRUPTED;
2200 		goto out_error;
2201 	}
2202 
2203 	/* Make sure the unwritten flag matches. */
2204 	if (XFS_IS_CORRUPT(mp,
2205 			   (flags & XFS_RMAP_UNWRITTEN) !=
2206 			   (ltrec.rm_flags & XFS_RMAP_UNWRITTEN))) {
2207 		xfs_btree_mark_sick(cur);
2208 		error = -EFSCORRUPTED;
2209 		goto out_error;
2210 	}
2211 
2212 	/* Check the offset. */
2213 	if (XFS_IS_CORRUPT(mp, ltrec.rm_offset > offset)) {
2214 		xfs_btree_mark_sick(cur);
2215 		error = -EFSCORRUPTED;
2216 		goto out_error;
2217 	}
2218 	if (XFS_IS_CORRUPT(mp, offset > ltoff + ltrec.rm_blockcount)) {
2219 		xfs_btree_mark_sick(cur);
2220 		error = -EFSCORRUPTED;
2221 		goto out_error;
2222 	}
2223 
2224 	if (ltrec.rm_startblock == bno && ltrec.rm_blockcount == len) {
2225 		/* Exact match, simply remove the record from rmap tree. */
2226 		error = xfs_rmap_delete(cur, ltrec.rm_startblock,
2227 				ltrec.rm_blockcount, ltrec.rm_owner,
2228 				ltrec.rm_offset, ltrec.rm_flags);
2229 		if (error)
2230 			goto out_error;
2231 	} else if (ltrec.rm_startblock == bno) {
2232 		/*
2233 		 * Overlap left hand side of extent: move the start, trim the
2234 		 * length and update the current record.
2235 		 *
2236 		 *       ltbno                ltlen
2237 		 * Orig:    |oooooooooooooooooooo|
2238 		 * Freeing: |fffffffff|
2239 		 * Result:            |rrrrrrrrrr|
2240 		 *         bno       len
2241 		 */
2242 
2243 		/* Delete prev rmap. */
2244 		error = xfs_rmap_delete(cur, ltrec.rm_startblock,
2245 				ltrec.rm_blockcount, ltrec.rm_owner,
2246 				ltrec.rm_offset, ltrec.rm_flags);
2247 		if (error)
2248 			goto out_error;
2249 
2250 		/* Add an rmap at the new offset. */
2251 		ltrec.rm_startblock += len;
2252 		ltrec.rm_blockcount -= len;
2253 		ltrec.rm_offset += len;
2254 		error = xfs_rmap_insert(cur, ltrec.rm_startblock,
2255 				ltrec.rm_blockcount, ltrec.rm_owner,
2256 				ltrec.rm_offset, ltrec.rm_flags);
2257 		if (error)
2258 			goto out_error;
2259 	} else if (ltrec.rm_startblock + ltrec.rm_blockcount == bno + len) {
2260 		/*
2261 		 * Overlap right hand side of extent: trim the length and
2262 		 * update the current record.
2263 		 *
2264 		 *       ltbno                ltlen
2265 		 * Orig:    |oooooooooooooooooooo|
2266 		 * Freeing:            |fffffffff|
2267 		 * Result:  |rrrrrrrrrr|
2268 		 *                    bno       len
2269 		 */
2270 		error = xfs_rmap_lookup_eq(cur, ltrec.rm_startblock,
2271 				ltrec.rm_blockcount, ltrec.rm_owner,
2272 				ltrec.rm_offset, ltrec.rm_flags, &i);
2273 		if (error)
2274 			goto out_error;
2275 		if (XFS_IS_CORRUPT(mp, i != 1)) {
2276 			xfs_btree_mark_sick(cur);
2277 			error = -EFSCORRUPTED;
2278 			goto out_error;
2279 		}
2280 		ltrec.rm_blockcount -= len;
2281 		error = xfs_rmap_update(cur, &ltrec);
2282 		if (error)
2283 			goto out_error;
2284 	} else {
2285 		/*
2286 		 * Overlap middle of extent: trim the length of the existing
2287 		 * record to the length of the new left-extent size, increment
2288 		 * the insertion position so we can insert a new record
2289 		 * containing the remaining right-extent space.
2290 		 *
2291 		 *       ltbno                ltlen
2292 		 * Orig:    |oooooooooooooooooooo|
2293 		 * Freeing:       |fffffffff|
2294 		 * Result:  |rrrrr|         |rrrr|
2295 		 *               bno       len
2296 		 */
2297 		xfs_extlen_t	orig_len = ltrec.rm_blockcount;
2298 
2299 		/* Shrink the left side of the rmap */
2300 		error = xfs_rmap_lookup_eq(cur, ltrec.rm_startblock,
2301 				ltrec.rm_blockcount, ltrec.rm_owner,
2302 				ltrec.rm_offset, ltrec.rm_flags, &i);
2303 		if (error)
2304 			goto out_error;
2305 		if (XFS_IS_CORRUPT(mp, i != 1)) {
2306 			xfs_btree_mark_sick(cur);
2307 			error = -EFSCORRUPTED;
2308 			goto out_error;
2309 		}
2310 		ltrec.rm_blockcount = bno - ltrec.rm_startblock;
2311 		error = xfs_rmap_update(cur, &ltrec);
2312 		if (error)
2313 			goto out_error;
2314 
2315 		/* Add an rmap at the new offset */
2316 		error = xfs_rmap_insert(cur, bno + len,
2317 				orig_len - len - ltrec.rm_blockcount,
2318 				ltrec.rm_owner, offset + len,
2319 				ltrec.rm_flags);
2320 		if (error)
2321 			goto out_error;
2322 	}
2323 
2324 	trace_xfs_rmap_unmap_done(mp, cur->bc_ag.pag->pag_agno, bno, len,
2325 			unwritten, oinfo);
2326 out_error:
2327 	if (error)
2328 		trace_xfs_rmap_unmap_error(cur->bc_mp,
2329 				cur->bc_ag.pag->pag_agno, error, _RET_IP_);
2330 	return error;
2331 }
2332 
2333 /*
2334  * Find an extent in the rmap btree and map it.  For rmap extent types that
2335  * can overlap (data fork rmaps on reflink filesystems) we must be careful
2336  * that the prev/next records in the btree might belong to another owner.
2337  * Therefore we must use delete+insert to alter any of the key fields.
2338  *
2339  * For every other situation there can only be one owner for a given extent,
2340  * so we can call the regular _alloc function.
2341  */
2342 STATIC int
2343 xfs_rmap_map_shared(
2344 	struct xfs_btree_cur		*cur,
2345 	xfs_agblock_t			bno,
2346 	xfs_extlen_t			len,
2347 	bool				unwritten,
2348 	const struct xfs_owner_info	*oinfo)
2349 {
2350 	struct xfs_mount		*mp = cur->bc_mp;
2351 	struct xfs_rmap_irec		ltrec;
2352 	struct xfs_rmap_irec		gtrec;
2353 	int				have_gt;
2354 	int				have_lt;
2355 	int				error = 0;
2356 	int				i;
2357 	uint64_t			owner;
2358 	uint64_t			offset;
2359 	unsigned int			flags = 0;
2360 
2361 	xfs_owner_info_unpack(oinfo, &owner, &offset, &flags);
2362 	if (unwritten)
2363 		flags |= XFS_RMAP_UNWRITTEN;
2364 	trace_xfs_rmap_map(mp, cur->bc_ag.pag->pag_agno, bno, len,
2365 			unwritten, oinfo);
2366 
2367 	/* Is there a left record that abuts our range? */
2368 	error = xfs_rmap_find_left_neighbor(cur, bno, owner, offset, flags,
2369 			&ltrec, &have_lt);
2370 	if (error)
2371 		goto out_error;
2372 	if (have_lt &&
2373 	    !xfs_rmap_is_mergeable(&ltrec, owner, flags))
2374 		have_lt = 0;
2375 
2376 	/* Is there a right record that abuts our range? */
2377 	error = xfs_rmap_lookup_eq(cur, bno + len, len, owner, offset + len,
2378 			flags, &have_gt);
2379 	if (error)
2380 		goto out_error;
2381 	if (have_gt) {
2382 		error = xfs_rmap_get_rec(cur, &gtrec, &have_gt);
2383 		if (error)
2384 			goto out_error;
2385 		if (XFS_IS_CORRUPT(mp, have_gt != 1)) {
2386 			xfs_btree_mark_sick(cur);
2387 			error = -EFSCORRUPTED;
2388 			goto out_error;
2389 		}
2390 		trace_xfs_rmap_find_right_neighbor_result(cur->bc_mp,
2391 			cur->bc_ag.pag->pag_agno, gtrec.rm_startblock,
2392 			gtrec.rm_blockcount, gtrec.rm_owner,
2393 			gtrec.rm_offset, gtrec.rm_flags);
2394 
2395 		if (!xfs_rmap_is_mergeable(&gtrec, owner, flags))
2396 			have_gt = 0;
2397 	}
2398 
2399 	if (have_lt &&
2400 	    ltrec.rm_startblock + ltrec.rm_blockcount == bno &&
2401 	    ltrec.rm_offset + ltrec.rm_blockcount == offset) {
2402 		/*
2403 		 * Left edge contiguous, merge into left record.
2404 		 *
2405 		 *       ltbno     ltlen
2406 		 * orig:   |ooooooooo|
2407 		 * adding:           |aaaaaaaaa|
2408 		 * result: |rrrrrrrrrrrrrrrrrrr|
2409 		 *                  bno       len
2410 		 */
2411 		ltrec.rm_blockcount += len;
2412 		if (have_gt &&
2413 		    bno + len == gtrec.rm_startblock &&
2414 		    offset + len == gtrec.rm_offset) {
2415 			/*
2416 			 * Right edge also contiguous, delete right record
2417 			 * and merge into left record.
2418 			 *
2419 			 *       ltbno     ltlen    gtbno     gtlen
2420 			 * orig:   |ooooooooo|         |ooooooooo|
2421 			 * adding:           |aaaaaaaaa|
2422 			 * result: |rrrrrrrrrrrrrrrrrrrrrrrrrrrrr|
2423 			 */
2424 			ltrec.rm_blockcount += gtrec.rm_blockcount;
2425 			error = xfs_rmap_delete(cur, gtrec.rm_startblock,
2426 					gtrec.rm_blockcount, gtrec.rm_owner,
2427 					gtrec.rm_offset, gtrec.rm_flags);
2428 			if (error)
2429 				goto out_error;
2430 		}
2431 
2432 		/* Point the cursor back to the left record and update. */
2433 		error = xfs_rmap_lookup_eq(cur, ltrec.rm_startblock,
2434 				ltrec.rm_blockcount, ltrec.rm_owner,
2435 				ltrec.rm_offset, ltrec.rm_flags, &i);
2436 		if (error)
2437 			goto out_error;
2438 		if (XFS_IS_CORRUPT(mp, i != 1)) {
2439 			xfs_btree_mark_sick(cur);
2440 			error = -EFSCORRUPTED;
2441 			goto out_error;
2442 		}
2443 
2444 		error = xfs_rmap_update(cur, &ltrec);
2445 		if (error)
2446 			goto out_error;
2447 	} else if (have_gt &&
2448 		   bno + len == gtrec.rm_startblock &&
2449 		   offset + len == gtrec.rm_offset) {
2450 		/*
2451 		 * Right edge contiguous, merge into right record.
2452 		 *
2453 		 *                 gtbno     gtlen
2454 		 * Orig:             |ooooooooo|
2455 		 * adding: |aaaaaaaaa|
2456 		 * Result: |rrrrrrrrrrrrrrrrrrr|
2457 		 *        bno       len
2458 		 */
2459 		/* Delete the old record. */
2460 		error = xfs_rmap_delete(cur, gtrec.rm_startblock,
2461 				gtrec.rm_blockcount, gtrec.rm_owner,
2462 				gtrec.rm_offset, gtrec.rm_flags);
2463 		if (error)
2464 			goto out_error;
2465 
2466 		/* Move the start and re-add it. */
2467 		gtrec.rm_startblock = bno;
2468 		gtrec.rm_blockcount += len;
2469 		gtrec.rm_offset = offset;
2470 		error = xfs_rmap_insert(cur, gtrec.rm_startblock,
2471 				gtrec.rm_blockcount, gtrec.rm_owner,
2472 				gtrec.rm_offset, gtrec.rm_flags);
2473 		if (error)
2474 			goto out_error;
2475 	} else {
2476 		/*
2477 		 * No contiguous edge with identical owner, insert
2478 		 * new record at current cursor position.
2479 		 */
2480 		error = xfs_rmap_insert(cur, bno, len, owner, offset, flags);
2481 		if (error)
2482 			goto out_error;
2483 	}
2484 
2485 	trace_xfs_rmap_map_done(mp, cur->bc_ag.pag->pag_agno, bno, len,
2486 			unwritten, oinfo);
2487 out_error:
2488 	if (error)
2489 		trace_xfs_rmap_map_error(cur->bc_mp,
2490 				cur->bc_ag.pag->pag_agno, error, _RET_IP_);
2491 	return error;
2492 }
2493 
2494 /* Insert a raw rmap into the rmapbt. */
2495 int
2496 xfs_rmap_map_raw(
2497 	struct xfs_btree_cur	*cur,
2498 	struct xfs_rmap_irec	*rmap)
2499 {
2500 	struct xfs_owner_info	oinfo;
2501 
2502 	xfs_owner_info_pack(&oinfo, rmap->rm_owner, rmap->rm_offset,
2503 			rmap->rm_flags);
2504 
2505 	if ((rmap->rm_flags & (XFS_RMAP_ATTR_FORK | XFS_RMAP_BMBT_BLOCK |
2506 			       XFS_RMAP_UNWRITTEN)) ||
2507 	    XFS_RMAP_NON_INODE_OWNER(rmap->rm_owner))
2508 		return xfs_rmap_map(cur, rmap->rm_startblock,
2509 				rmap->rm_blockcount,
2510 				rmap->rm_flags & XFS_RMAP_UNWRITTEN,
2511 				&oinfo);
2512 
2513 	return xfs_rmap_map_shared(cur, rmap->rm_startblock,
2514 			rmap->rm_blockcount,
2515 			rmap->rm_flags & XFS_RMAP_UNWRITTEN,
2516 			&oinfo);
2517 }
2518 
2519 struct xfs_rmap_query_range_info {
2520 	xfs_rmap_query_range_fn	fn;
2521 	void				*priv;
2522 };
2523 
2524 /* Format btree record and pass to our callback. */
2525 STATIC int
2526 xfs_rmap_query_range_helper(
2527 	struct xfs_btree_cur		*cur,
2528 	const union xfs_btree_rec	*rec,
2529 	void				*priv)
2530 {
2531 	struct xfs_rmap_query_range_info	*query = priv;
2532 	struct xfs_rmap_irec			irec;
2533 	xfs_failaddr_t				fa;
2534 
2535 	fa = xfs_rmap_btrec_to_irec(rec, &irec);
2536 	if (!fa)
2537 		fa = xfs_rmap_check_btrec(cur, &irec);
2538 	if (fa)
2539 		return xfs_rmap_complain_bad_rec(cur, fa, &irec);
2540 
2541 	return query->fn(cur, &irec, query->priv);
2542 }
2543 
2544 /* Find all rmaps between two keys. */
2545 int
2546 xfs_rmap_query_range(
2547 	struct xfs_btree_cur			*cur,
2548 	const struct xfs_rmap_irec		*low_rec,
2549 	const struct xfs_rmap_irec		*high_rec,
2550 	xfs_rmap_query_range_fn			fn,
2551 	void					*priv)
2552 {
2553 	union xfs_btree_irec			low_brec = { .r = *low_rec };
2554 	union xfs_btree_irec			high_brec = { .r = *high_rec };
2555 	struct xfs_rmap_query_range_info	query = { .priv = priv, .fn = fn };
2556 
2557 	return xfs_btree_query_range(cur, &low_brec, &high_brec,
2558 			xfs_rmap_query_range_helper, &query);
2559 }
2560 
2561 /* Find all rmaps. */
2562 int
2563 xfs_rmap_query_all(
2564 	struct xfs_btree_cur			*cur,
2565 	xfs_rmap_query_range_fn			fn,
2566 	void					*priv)
2567 {
2568 	struct xfs_rmap_query_range_info	query;
2569 
2570 	query.priv = priv;
2571 	query.fn = fn;
2572 	return xfs_btree_query_all(cur, xfs_rmap_query_range_helper, &query);
2573 }
2574 
2575 /* Clean up after calling xfs_rmap_finish_one. */
2576 void
2577 xfs_rmap_finish_one_cleanup(
2578 	struct xfs_trans	*tp,
2579 	struct xfs_btree_cur	*rcur,
2580 	int			error)
2581 {
2582 	struct xfs_buf		*agbp;
2583 
2584 	if (rcur == NULL)
2585 		return;
2586 	agbp = rcur->bc_ag.agbp;
2587 	xfs_btree_del_cursor(rcur, error);
2588 	if (error)
2589 		xfs_trans_brelse(tp, agbp);
2590 }
2591 
2592 /* Commit an rmap operation into the ondisk tree. */
2593 int
2594 __xfs_rmap_finish_intent(
2595 	struct xfs_btree_cur		*rcur,
2596 	enum xfs_rmap_intent_type	op,
2597 	xfs_agblock_t			bno,
2598 	xfs_extlen_t			len,
2599 	const struct xfs_owner_info	*oinfo,
2600 	bool				unwritten)
2601 {
2602 	switch (op) {
2603 	case XFS_RMAP_ALLOC:
2604 	case XFS_RMAP_MAP:
2605 		return xfs_rmap_map(rcur, bno, len, unwritten, oinfo);
2606 	case XFS_RMAP_MAP_SHARED:
2607 		return xfs_rmap_map_shared(rcur, bno, len, unwritten, oinfo);
2608 	case XFS_RMAP_FREE:
2609 	case XFS_RMAP_UNMAP:
2610 		return xfs_rmap_unmap(rcur, bno, len, unwritten, oinfo);
2611 	case XFS_RMAP_UNMAP_SHARED:
2612 		return xfs_rmap_unmap_shared(rcur, bno, len, unwritten, oinfo);
2613 	case XFS_RMAP_CONVERT:
2614 		return xfs_rmap_convert(rcur, bno, len, !unwritten, oinfo);
2615 	case XFS_RMAP_CONVERT_SHARED:
2616 		return xfs_rmap_convert_shared(rcur, bno, len, !unwritten,
2617 				oinfo);
2618 	default:
2619 		ASSERT(0);
2620 		return -EFSCORRUPTED;
2621 	}
2622 }
2623 
2624 /*
2625  * Process one of the deferred rmap operations.  We pass back the
2626  * btree cursor to maintain our lock on the rmapbt between calls.
2627  * This saves time and eliminates a buffer deadlock between the
2628  * superblock and the AGF because we'll always grab them in the same
2629  * order.
2630  */
2631 int
2632 xfs_rmap_finish_one(
2633 	struct xfs_trans		*tp,
2634 	struct xfs_rmap_intent		*ri,
2635 	struct xfs_btree_cur		**pcur)
2636 {
2637 	struct xfs_mount		*mp = tp->t_mountp;
2638 	struct xfs_btree_cur		*rcur;
2639 	struct xfs_buf			*agbp = NULL;
2640 	int				error = 0;
2641 	struct xfs_owner_info		oinfo;
2642 	xfs_agblock_t			bno;
2643 	bool				unwritten;
2644 
2645 	bno = XFS_FSB_TO_AGBNO(mp, ri->ri_bmap.br_startblock);
2646 
2647 	trace_xfs_rmap_deferred(mp, ri->ri_pag->pag_agno, ri->ri_type, bno,
2648 			ri->ri_owner, ri->ri_whichfork,
2649 			ri->ri_bmap.br_startoff, ri->ri_bmap.br_blockcount,
2650 			ri->ri_bmap.br_state);
2651 
2652 	if (XFS_TEST_ERROR(false, mp, XFS_ERRTAG_RMAP_FINISH_ONE))
2653 		return -EIO;
2654 
2655 	/*
2656 	 * If we haven't gotten a cursor or the cursor AG doesn't match
2657 	 * the startblock, get one now.
2658 	 */
2659 	rcur = *pcur;
2660 	if (rcur != NULL && rcur->bc_ag.pag != ri->ri_pag) {
2661 		xfs_rmap_finish_one_cleanup(tp, rcur, 0);
2662 		rcur = NULL;
2663 		*pcur = NULL;
2664 	}
2665 	if (rcur == NULL) {
2666 		/*
2667 		 * Refresh the freelist before we start changing the
2668 		 * rmapbt, because a shape change could cause us to
2669 		 * allocate blocks.
2670 		 */
2671 		error = xfs_free_extent_fix_freelist(tp, ri->ri_pag, &agbp);
2672 		if (error) {
2673 			xfs_ag_mark_sick(ri->ri_pag, XFS_SICK_AG_AGFL);
2674 			return error;
2675 		}
2676 		if (XFS_IS_CORRUPT(tp->t_mountp, !agbp)) {
2677 			xfs_ag_mark_sick(ri->ri_pag, XFS_SICK_AG_AGFL);
2678 			return -EFSCORRUPTED;
2679 		}
2680 
2681 		rcur = xfs_rmapbt_init_cursor(mp, tp, agbp, ri->ri_pag);
2682 	}
2683 	*pcur = rcur;
2684 
2685 	xfs_rmap_ino_owner(&oinfo, ri->ri_owner, ri->ri_whichfork,
2686 			ri->ri_bmap.br_startoff);
2687 	unwritten = ri->ri_bmap.br_state == XFS_EXT_UNWRITTEN;
2688 	bno = XFS_FSB_TO_AGBNO(rcur->bc_mp, ri->ri_bmap.br_startblock);
2689 
2690 	error = __xfs_rmap_finish_intent(rcur, ri->ri_type, bno,
2691 			ri->ri_bmap.br_blockcount, &oinfo, unwritten);
2692 	if (error)
2693 		return error;
2694 
2695 	xfs_rmap_update_hook(tp, ri->ri_pag, ri->ri_type, bno,
2696 			ri->ri_bmap.br_blockcount, unwritten, &oinfo);
2697 	return 0;
2698 }
2699 
2700 /*
2701  * Don't defer an rmap if we aren't an rmap filesystem.
2702  */
2703 static bool
2704 xfs_rmap_update_is_needed(
2705 	struct xfs_mount	*mp,
2706 	int			whichfork)
2707 {
2708 	return xfs_has_rmapbt(mp) && whichfork != XFS_COW_FORK;
2709 }
2710 
2711 /*
2712  * Record a rmap intent; the list is kept sorted first by AG and then by
2713  * increasing age.
2714  */
2715 static void
2716 __xfs_rmap_add(
2717 	struct xfs_trans		*tp,
2718 	enum xfs_rmap_intent_type	type,
2719 	uint64_t			owner,
2720 	int				whichfork,
2721 	struct xfs_bmbt_irec		*bmap)
2722 {
2723 	struct xfs_rmap_intent		*ri;
2724 
2725 	trace_xfs_rmap_defer(tp->t_mountp,
2726 			XFS_FSB_TO_AGNO(tp->t_mountp, bmap->br_startblock),
2727 			type,
2728 			XFS_FSB_TO_AGBNO(tp->t_mountp, bmap->br_startblock),
2729 			owner, whichfork,
2730 			bmap->br_startoff,
2731 			bmap->br_blockcount,
2732 			bmap->br_state);
2733 
2734 	ri = kmem_cache_alloc(xfs_rmap_intent_cache, GFP_KERNEL | __GFP_NOFAIL);
2735 	INIT_LIST_HEAD(&ri->ri_list);
2736 	ri->ri_type = type;
2737 	ri->ri_owner = owner;
2738 	ri->ri_whichfork = whichfork;
2739 	ri->ri_bmap = *bmap;
2740 
2741 	xfs_rmap_update_get_group(tp->t_mountp, ri);
2742 	xfs_defer_add(tp, &ri->ri_list, &xfs_rmap_update_defer_type);
2743 }
2744 
2745 /* Map an extent into a file. */
2746 void
2747 xfs_rmap_map_extent(
2748 	struct xfs_trans	*tp,
2749 	struct xfs_inode	*ip,
2750 	int			whichfork,
2751 	struct xfs_bmbt_irec	*PREV)
2752 {
2753 	enum xfs_rmap_intent_type type = XFS_RMAP_MAP;
2754 
2755 	if (!xfs_rmap_update_is_needed(tp->t_mountp, whichfork))
2756 		return;
2757 
2758 	if (whichfork != XFS_ATTR_FORK && xfs_is_reflink_inode(ip))
2759 		type = XFS_RMAP_MAP_SHARED;
2760 
2761 	__xfs_rmap_add(tp, type, ip->i_ino, whichfork, PREV);
2762 }
2763 
2764 /* Unmap an extent out of a file. */
2765 void
2766 xfs_rmap_unmap_extent(
2767 	struct xfs_trans	*tp,
2768 	struct xfs_inode	*ip,
2769 	int			whichfork,
2770 	struct xfs_bmbt_irec	*PREV)
2771 {
2772 	enum xfs_rmap_intent_type type = XFS_RMAP_UNMAP;
2773 
2774 	if (!xfs_rmap_update_is_needed(tp->t_mountp, whichfork))
2775 		return;
2776 
2777 	if (whichfork != XFS_ATTR_FORK && xfs_is_reflink_inode(ip))
2778 		type = XFS_RMAP_UNMAP_SHARED;
2779 
2780 	__xfs_rmap_add(tp, type, ip->i_ino, whichfork, PREV);
2781 }
2782 
2783 /*
2784  * Convert a data fork extent from unwritten to real or vice versa.
2785  *
2786  * Note that tp can be NULL here as no transaction is used for COW fork
2787  * unwritten conversion.
2788  */
2789 void
2790 xfs_rmap_convert_extent(
2791 	struct xfs_mount	*mp,
2792 	struct xfs_trans	*tp,
2793 	struct xfs_inode	*ip,
2794 	int			whichfork,
2795 	struct xfs_bmbt_irec	*PREV)
2796 {
2797 	enum xfs_rmap_intent_type type = XFS_RMAP_CONVERT;
2798 
2799 	if (!xfs_rmap_update_is_needed(mp, whichfork))
2800 		return;
2801 
2802 	if (whichfork != XFS_ATTR_FORK && xfs_is_reflink_inode(ip))
2803 		type = XFS_RMAP_CONVERT_SHARED;
2804 
2805 	__xfs_rmap_add(tp, type, ip->i_ino, whichfork, PREV);
2806 }
2807 
2808 /* Schedule the creation of an rmap for non-file data. */
2809 void
2810 xfs_rmap_alloc_extent(
2811 	struct xfs_trans	*tp,
2812 	xfs_agnumber_t		agno,
2813 	xfs_agblock_t		bno,
2814 	xfs_extlen_t		len,
2815 	uint64_t		owner)
2816 {
2817 	struct xfs_bmbt_irec	bmap;
2818 
2819 	if (!xfs_rmap_update_is_needed(tp->t_mountp, XFS_DATA_FORK))
2820 		return;
2821 
2822 	bmap.br_startblock = XFS_AGB_TO_FSB(tp->t_mountp, agno, bno);
2823 	bmap.br_blockcount = len;
2824 	bmap.br_startoff = 0;
2825 	bmap.br_state = XFS_EXT_NORM;
2826 
2827 	__xfs_rmap_add(tp, XFS_RMAP_ALLOC, owner, XFS_DATA_FORK, &bmap);
2828 }
2829 
2830 /* Schedule the deletion of an rmap for non-file data. */
2831 void
2832 xfs_rmap_free_extent(
2833 	struct xfs_trans	*tp,
2834 	xfs_agnumber_t		agno,
2835 	xfs_agblock_t		bno,
2836 	xfs_extlen_t		len,
2837 	uint64_t		owner)
2838 {
2839 	struct xfs_bmbt_irec	bmap;
2840 
2841 	if (!xfs_rmap_update_is_needed(tp->t_mountp, XFS_DATA_FORK))
2842 		return;
2843 
2844 	bmap.br_startblock = XFS_AGB_TO_FSB(tp->t_mountp, agno, bno);
2845 	bmap.br_blockcount = len;
2846 	bmap.br_startoff = 0;
2847 	bmap.br_state = XFS_EXT_NORM;
2848 
2849 	__xfs_rmap_add(tp, XFS_RMAP_FREE, owner, XFS_DATA_FORK, &bmap);
2850 }
2851 
2852 /* Compare rmap records.  Returns -1 if a < b, 1 if a > b, and 0 if equal. */
2853 int
2854 xfs_rmap_compare(
2855 	const struct xfs_rmap_irec	*a,
2856 	const struct xfs_rmap_irec	*b)
2857 {
2858 	__u64				oa;
2859 	__u64				ob;
2860 
2861 	oa = xfs_rmap_irec_offset_pack(a);
2862 	ob = xfs_rmap_irec_offset_pack(b);
2863 
2864 	if (a->rm_startblock < b->rm_startblock)
2865 		return -1;
2866 	else if (a->rm_startblock > b->rm_startblock)
2867 		return 1;
2868 	else if (a->rm_owner < b->rm_owner)
2869 		return -1;
2870 	else if (a->rm_owner > b->rm_owner)
2871 		return 1;
2872 	else if (oa < ob)
2873 		return -1;
2874 	else if (oa > ob)
2875 		return 1;
2876 	else
2877 		return 0;
2878 }
2879 
2880 /*
2881  * Scan the physical storage part of the keyspace of the reverse mapping index
2882  * and tell us if the area has no records, is fully mapped by records, or is
2883  * partially filled.
2884  */
2885 int
2886 xfs_rmap_has_records(
2887 	struct xfs_btree_cur	*cur,
2888 	xfs_agblock_t		bno,
2889 	xfs_extlen_t		len,
2890 	enum xbtree_recpacking	*outcome)
2891 {
2892 	union xfs_btree_key	mask = {
2893 		.rmap.rm_startblock = cpu_to_be32(-1U),
2894 	};
2895 	union xfs_btree_irec	low;
2896 	union xfs_btree_irec	high;
2897 
2898 	memset(&low, 0, sizeof(low));
2899 	low.r.rm_startblock = bno;
2900 	memset(&high, 0xFF, sizeof(high));
2901 	high.r.rm_startblock = bno + len - 1;
2902 
2903 	return xfs_btree_has_records(cur, &low, &high, &mask, outcome);
2904 }
2905 
2906 struct xfs_rmap_ownercount {
2907 	/* Owner that we're looking for. */
2908 	struct xfs_rmap_irec	good;
2909 
2910 	/* rmap search keys */
2911 	struct xfs_rmap_irec	low;
2912 	struct xfs_rmap_irec	high;
2913 
2914 	struct xfs_rmap_matches	*results;
2915 
2916 	/* Stop early if we find a nonmatch? */
2917 	bool			stop_on_nonmatch;
2918 };
2919 
2920 /* Does this rmap represent space that can have multiple owners? */
2921 static inline bool
2922 xfs_rmap_shareable(
2923 	struct xfs_mount		*mp,
2924 	const struct xfs_rmap_irec	*rmap)
2925 {
2926 	if (!xfs_has_reflink(mp))
2927 		return false;
2928 	if (XFS_RMAP_NON_INODE_OWNER(rmap->rm_owner))
2929 		return false;
2930 	if (rmap->rm_flags & (XFS_RMAP_ATTR_FORK |
2931 			      XFS_RMAP_BMBT_BLOCK))
2932 		return false;
2933 	return true;
2934 }
2935 
2936 static inline void
2937 xfs_rmap_ownercount_init(
2938 	struct xfs_rmap_ownercount	*roc,
2939 	xfs_agblock_t			bno,
2940 	xfs_extlen_t			len,
2941 	const struct xfs_owner_info	*oinfo,
2942 	struct xfs_rmap_matches		*results)
2943 {
2944 	memset(roc, 0, sizeof(*roc));
2945 	roc->results = results;
2946 
2947 	roc->low.rm_startblock = bno;
2948 	memset(&roc->high, 0xFF, sizeof(roc->high));
2949 	roc->high.rm_startblock = bno + len - 1;
2950 
2951 	memset(results, 0, sizeof(*results));
2952 	roc->good.rm_startblock = bno;
2953 	roc->good.rm_blockcount = len;
2954 	roc->good.rm_owner = oinfo->oi_owner;
2955 	roc->good.rm_offset = oinfo->oi_offset;
2956 	if (oinfo->oi_flags & XFS_OWNER_INFO_ATTR_FORK)
2957 		roc->good.rm_flags |= XFS_RMAP_ATTR_FORK;
2958 	if (oinfo->oi_flags & XFS_OWNER_INFO_BMBT_BLOCK)
2959 		roc->good.rm_flags |= XFS_RMAP_BMBT_BLOCK;
2960 }
2961 
2962 /* Figure out if this is a match for the owner. */
2963 STATIC int
2964 xfs_rmap_count_owners_helper(
2965 	struct xfs_btree_cur		*cur,
2966 	const struct xfs_rmap_irec	*rec,
2967 	void				*priv)
2968 {
2969 	struct xfs_rmap_ownercount	*roc = priv;
2970 	struct xfs_rmap_irec		check = *rec;
2971 	unsigned int			keyflags;
2972 	bool				filedata;
2973 	int64_t				delta;
2974 
2975 	filedata = !XFS_RMAP_NON_INODE_OWNER(check.rm_owner) &&
2976 		   !(check.rm_flags & XFS_RMAP_BMBT_BLOCK);
2977 
2978 	/* Trim the part of check that comes before the comparison range. */
2979 	delta = (int64_t)roc->good.rm_startblock - check.rm_startblock;
2980 	if (delta > 0) {
2981 		check.rm_startblock += delta;
2982 		check.rm_blockcount -= delta;
2983 		if (filedata)
2984 			check.rm_offset += delta;
2985 	}
2986 
2987 	/* Trim the part of check that comes after the comparison range. */
2988 	delta = (check.rm_startblock + check.rm_blockcount) -
2989 		(roc->good.rm_startblock + roc->good.rm_blockcount);
2990 	if (delta > 0)
2991 		check.rm_blockcount -= delta;
2992 
2993 	/* Don't care about unwritten status for establishing ownership. */
2994 	keyflags = check.rm_flags & (XFS_RMAP_ATTR_FORK | XFS_RMAP_BMBT_BLOCK);
2995 
2996 	if (check.rm_startblock	== roc->good.rm_startblock &&
2997 	    check.rm_blockcount	== roc->good.rm_blockcount &&
2998 	    check.rm_owner	== roc->good.rm_owner &&
2999 	    check.rm_offset	== roc->good.rm_offset &&
3000 	    keyflags		== roc->good.rm_flags) {
3001 		roc->results->matches++;
3002 	} else {
3003 		roc->results->non_owner_matches++;
3004 		if (xfs_rmap_shareable(cur->bc_mp, &roc->good) ^
3005 		    xfs_rmap_shareable(cur->bc_mp, &check))
3006 			roc->results->bad_non_owner_matches++;
3007 	}
3008 
3009 	if (roc->results->non_owner_matches && roc->stop_on_nonmatch)
3010 		return -ECANCELED;
3011 
3012 	return 0;
3013 }
3014 
3015 /* Count the number of owners and non-owners of this range of blocks. */
3016 int
3017 xfs_rmap_count_owners(
3018 	struct xfs_btree_cur		*cur,
3019 	xfs_agblock_t			bno,
3020 	xfs_extlen_t			len,
3021 	const struct xfs_owner_info	*oinfo,
3022 	struct xfs_rmap_matches		*results)
3023 {
3024 	struct xfs_rmap_ownercount	roc;
3025 	int				error;
3026 
3027 	xfs_rmap_ownercount_init(&roc, bno, len, oinfo, results);
3028 	error = xfs_rmap_query_range(cur, &roc.low, &roc.high,
3029 			xfs_rmap_count_owners_helper, &roc);
3030 	if (error)
3031 		return error;
3032 
3033 	/*
3034 	 * There can't be any non-owner rmaps that conflict with the given
3035 	 * owner if we didn't find any rmaps matching the owner.
3036 	 */
3037 	if (!results->matches)
3038 		results->bad_non_owner_matches = 0;
3039 
3040 	return 0;
3041 }
3042 
3043 /*
3044  * Given an extent and some owner info, can we find records overlapping
3045  * the extent whose owner info does not match the given owner?
3046  */
3047 int
3048 xfs_rmap_has_other_keys(
3049 	struct xfs_btree_cur		*cur,
3050 	xfs_agblock_t			bno,
3051 	xfs_extlen_t			len,
3052 	const struct xfs_owner_info	*oinfo,
3053 	bool				*has_other)
3054 {
3055 	struct xfs_rmap_matches		res;
3056 	struct xfs_rmap_ownercount	roc;
3057 	int				error;
3058 
3059 	xfs_rmap_ownercount_init(&roc, bno, len, oinfo, &res);
3060 	roc.stop_on_nonmatch = true;
3061 
3062 	error = xfs_rmap_query_range(cur, &roc.low, &roc.high,
3063 			xfs_rmap_count_owners_helper, &roc);
3064 	if (error == -ECANCELED) {
3065 		*has_other = true;
3066 		return 0;
3067 	}
3068 	if (error)
3069 		return error;
3070 
3071 	*has_other = false;
3072 	return 0;
3073 }
3074 
3075 const struct xfs_owner_info XFS_RMAP_OINFO_SKIP_UPDATE = {
3076 	.oi_owner = XFS_RMAP_OWN_NULL,
3077 };
3078 const struct xfs_owner_info XFS_RMAP_OINFO_ANY_OWNER = {
3079 	.oi_owner = XFS_RMAP_OWN_UNKNOWN,
3080 };
3081 const struct xfs_owner_info XFS_RMAP_OINFO_FS = {
3082 	.oi_owner = XFS_RMAP_OWN_FS,
3083 };
3084 const struct xfs_owner_info XFS_RMAP_OINFO_LOG = {
3085 	.oi_owner = XFS_RMAP_OWN_LOG,
3086 };
3087 const struct xfs_owner_info XFS_RMAP_OINFO_AG = {
3088 	.oi_owner = XFS_RMAP_OWN_AG,
3089 };
3090 const struct xfs_owner_info XFS_RMAP_OINFO_INOBT = {
3091 	.oi_owner = XFS_RMAP_OWN_INOBT,
3092 };
3093 const struct xfs_owner_info XFS_RMAP_OINFO_INODES = {
3094 	.oi_owner = XFS_RMAP_OWN_INODES,
3095 };
3096 const struct xfs_owner_info XFS_RMAP_OINFO_REFC = {
3097 	.oi_owner = XFS_RMAP_OWN_REFC,
3098 };
3099 const struct xfs_owner_info XFS_RMAP_OINFO_COW = {
3100 	.oi_owner = XFS_RMAP_OWN_COW,
3101 };
3102 
3103 int __init
3104 xfs_rmap_intent_init_cache(void)
3105 {
3106 	xfs_rmap_intent_cache = kmem_cache_create("xfs_rmap_intent",
3107 			sizeof(struct xfs_rmap_intent),
3108 			0, 0, NULL);
3109 
3110 	return xfs_rmap_intent_cache != NULL ? 0 : -ENOMEM;
3111 }
3112 
3113 void
3114 xfs_rmap_intent_destroy_cache(void)
3115 {
3116 	kmem_cache_destroy(xfs_rmap_intent_cache);
3117 	xfs_rmap_intent_cache = NULL;
3118 }
3119