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1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Copyright (C) 2016 Oracle. All Rights Reserved.
4 * Author: Darrick J. Wong <darrick.wong@oracle.com>
5 */
6#include "xfs.h"
7#include "xfs_fs.h"
8#include "xfs_shared.h"
9#include "xfs_format.h"
10#include "xfs_log_format.h"
11#include "xfs_trans_resv.h"
12#include "xfs_mount.h"
13#include "xfs_defer.h"
14#include "xfs_btree.h"
15#include "xfs_bmap.h"
16#include "xfs_refcount_btree.h"
17#include "xfs_alloc.h"
18#include "xfs_errortag.h"
19#include "xfs_error.h"
20#include "xfs_trace.h"
21#include "xfs_trans.h"
22#include "xfs_bit.h"
23#include "xfs_refcount.h"
24#include "xfs_rmap.h"
25#include "xfs_ag.h"
26
27struct kmem_cache *xfs_refcount_intent_cache;
28
29/* Allowable refcount adjustment amounts. */
30enum xfs_refc_adjust_op {
31 XFS_REFCOUNT_ADJUST_INCREASE = 1,
32 XFS_REFCOUNT_ADJUST_DECREASE = -1,
33 XFS_REFCOUNT_ADJUST_COW_ALLOC = 0,
34 XFS_REFCOUNT_ADJUST_COW_FREE = -1,
35};
36
37STATIC int __xfs_refcount_cow_alloc(struct xfs_btree_cur *rcur,
38 xfs_agblock_t agbno, xfs_extlen_t aglen);
39STATIC int __xfs_refcount_cow_free(struct xfs_btree_cur *rcur,
40 xfs_agblock_t agbno, xfs_extlen_t aglen);
41
42/*
43 * Look up the first record less than or equal to [bno, len] in the btree
44 * given by cur.
45 */
46int
47xfs_refcount_lookup_le(
48 struct xfs_btree_cur *cur,
49 enum xfs_refc_domain domain,
50 xfs_agblock_t bno,
51 int *stat)
52{
53 trace_xfs_refcount_lookup(cur->bc_mp, cur->bc_ag.pag->pag_agno,
54 xfs_refcount_encode_startblock(bno, domain),
55 XFS_LOOKUP_LE);
56 cur->bc_rec.rc.rc_startblock = bno;
57 cur->bc_rec.rc.rc_blockcount = 0;
58 cur->bc_rec.rc.rc_domain = domain;
59 return xfs_btree_lookup(cur, XFS_LOOKUP_LE, stat);
60}
61
62/*
63 * Look up the first record greater than or equal to [bno, len] in the btree
64 * given by cur.
65 */
66int
67xfs_refcount_lookup_ge(
68 struct xfs_btree_cur *cur,
69 enum xfs_refc_domain domain,
70 xfs_agblock_t bno,
71 int *stat)
72{
73 trace_xfs_refcount_lookup(cur->bc_mp, cur->bc_ag.pag->pag_agno,
74 xfs_refcount_encode_startblock(bno, domain),
75 XFS_LOOKUP_GE);
76 cur->bc_rec.rc.rc_startblock = bno;
77 cur->bc_rec.rc.rc_blockcount = 0;
78 cur->bc_rec.rc.rc_domain = domain;
79 return xfs_btree_lookup(cur, XFS_LOOKUP_GE, stat);
80}
81
82/*
83 * Look up the first record equal to [bno, len] in the btree
84 * given by cur.
85 */
86int
87xfs_refcount_lookup_eq(
88 struct xfs_btree_cur *cur,
89 enum xfs_refc_domain domain,
90 xfs_agblock_t bno,
91 int *stat)
92{
93 trace_xfs_refcount_lookup(cur->bc_mp, cur->bc_ag.pag->pag_agno,
94 xfs_refcount_encode_startblock(bno, domain),
95 XFS_LOOKUP_LE);
96 cur->bc_rec.rc.rc_startblock = bno;
97 cur->bc_rec.rc.rc_blockcount = 0;
98 cur->bc_rec.rc.rc_domain = domain;
99 return xfs_btree_lookup(cur, XFS_LOOKUP_EQ, stat);
100}
101
102/* Convert on-disk record to in-core format. */
103void
104xfs_refcount_btrec_to_irec(
105 const union xfs_btree_rec *rec,
106 struct xfs_refcount_irec *irec)
107{
108 uint32_t start;
109
110 start = be32_to_cpu(rec->refc.rc_startblock);
111 if (start & XFS_REFC_COWFLAG) {
112 start &= ~XFS_REFC_COWFLAG;
113 irec->rc_domain = XFS_REFC_DOMAIN_COW;
114 } else {
115 irec->rc_domain = XFS_REFC_DOMAIN_SHARED;
116 }
117
118 irec->rc_startblock = start;
119 irec->rc_blockcount = be32_to_cpu(rec->refc.rc_blockcount);
120 irec->rc_refcount = be32_to_cpu(rec->refc.rc_refcount);
121}
122
123/* Simple checks for refcount records. */
124xfs_failaddr_t
125xfs_refcount_check_irec(
126 struct xfs_perag *pag,
127 const struct xfs_refcount_irec *irec)
128{
129 if (irec->rc_blockcount == 0 || irec->rc_blockcount > MAXREFCEXTLEN)
130 return __this_address;
131
132 if (!xfs_refcount_check_domain(irec))
133 return __this_address;
134
135 /* check for valid extent range, including overflow */
136 if (!xfs_verify_agbext(pag, irec->rc_startblock, irec->rc_blockcount))
137 return __this_address;
138
139 if (irec->rc_refcount == 0 || irec->rc_refcount > MAXREFCOUNT)
140 return __this_address;
141
142 return NULL;
143}
144
145static inline int
146xfs_refcount_complain_bad_rec(
147 struct xfs_btree_cur *cur,
148 xfs_failaddr_t fa,
149 const struct xfs_refcount_irec *irec)
150{
151 struct xfs_mount *mp = cur->bc_mp;
152
153 xfs_warn(mp,
154 "Refcount BTree record corruption in AG %d detected at %pS!",
155 cur->bc_ag.pag->pag_agno, fa);
156 xfs_warn(mp,
157 "Start block 0x%x, block count 0x%x, references 0x%x",
158 irec->rc_startblock, irec->rc_blockcount, irec->rc_refcount);
159 return -EFSCORRUPTED;
160}
161
162/*
163 * Get the data from the pointed-to record.
164 */
165int
166xfs_refcount_get_rec(
167 struct xfs_btree_cur *cur,
168 struct xfs_refcount_irec *irec,
169 int *stat)
170{
171 union xfs_btree_rec *rec;
172 xfs_failaddr_t fa;
173 int error;
174
175 error = xfs_btree_get_rec(cur, &rec, stat);
176 if (error || !*stat)
177 return error;
178
179 xfs_refcount_btrec_to_irec(rec, irec);
180 fa = xfs_refcount_check_irec(cur->bc_ag.pag, irec);
181 if (fa)
182 return xfs_refcount_complain_bad_rec(cur, fa, irec);
183
184 trace_xfs_refcount_get(cur->bc_mp, cur->bc_ag.pag->pag_agno, irec);
185 return 0;
186}
187
188/*
189 * Update the record referred to by cur to the value given
190 * by [bno, len, refcount].
191 * This either works (return 0) or gets an EFSCORRUPTED error.
192 */
193STATIC int
194xfs_refcount_update(
195 struct xfs_btree_cur *cur,
196 struct xfs_refcount_irec *irec)
197{
198 union xfs_btree_rec rec;
199 uint32_t start;
200 int error;
201
202 trace_xfs_refcount_update(cur->bc_mp, cur->bc_ag.pag->pag_agno, irec);
203
204 start = xfs_refcount_encode_startblock(irec->rc_startblock,
205 irec->rc_domain);
206 rec.refc.rc_startblock = cpu_to_be32(start);
207 rec.refc.rc_blockcount = cpu_to_be32(irec->rc_blockcount);
208 rec.refc.rc_refcount = cpu_to_be32(irec->rc_refcount);
209
210 error = xfs_btree_update(cur, &rec);
211 if (error)
212 trace_xfs_refcount_update_error(cur->bc_mp,
213 cur->bc_ag.pag->pag_agno, error, _RET_IP_);
214 return error;
215}
216
217/*
218 * Insert the record referred to by cur to the value given
219 * by [bno, len, refcount].
220 * This either works (return 0) or gets an EFSCORRUPTED error.
221 */
222int
223xfs_refcount_insert(
224 struct xfs_btree_cur *cur,
225 struct xfs_refcount_irec *irec,
226 int *i)
227{
228 int error;
229
230 trace_xfs_refcount_insert(cur->bc_mp, cur->bc_ag.pag->pag_agno, irec);
231
232 cur->bc_rec.rc.rc_startblock = irec->rc_startblock;
233 cur->bc_rec.rc.rc_blockcount = irec->rc_blockcount;
234 cur->bc_rec.rc.rc_refcount = irec->rc_refcount;
235 cur->bc_rec.rc.rc_domain = irec->rc_domain;
236
237 error = xfs_btree_insert(cur, i);
238 if (error)
239 goto out_error;
240 if (XFS_IS_CORRUPT(cur->bc_mp, *i != 1)) {
241 error = -EFSCORRUPTED;
242 goto out_error;
243 }
244
245out_error:
246 if (error)
247 trace_xfs_refcount_insert_error(cur->bc_mp,
248 cur->bc_ag.pag->pag_agno, error, _RET_IP_);
249 return error;
250}
251
252/*
253 * Remove the record referred to by cur, then set the pointer to the spot
254 * where the record could be re-inserted, in case we want to increment or
255 * decrement the cursor.
256 * This either works (return 0) or gets an EFSCORRUPTED error.
257 */
258STATIC int
259xfs_refcount_delete(
260 struct xfs_btree_cur *cur,
261 int *i)
262{
263 struct xfs_refcount_irec irec;
264 int found_rec;
265 int error;
266
267 error = xfs_refcount_get_rec(cur, &irec, &found_rec);
268 if (error)
269 goto out_error;
270 if (XFS_IS_CORRUPT(cur->bc_mp, found_rec != 1)) {
271 error = -EFSCORRUPTED;
272 goto out_error;
273 }
274 trace_xfs_refcount_delete(cur->bc_mp, cur->bc_ag.pag->pag_agno, &irec);
275 error = xfs_btree_delete(cur, i);
276 if (XFS_IS_CORRUPT(cur->bc_mp, *i != 1)) {
277 error = -EFSCORRUPTED;
278 goto out_error;
279 }
280 if (error)
281 goto out_error;
282 error = xfs_refcount_lookup_ge(cur, irec.rc_domain, irec.rc_startblock,
283 &found_rec);
284out_error:
285 if (error)
286 trace_xfs_refcount_delete_error(cur->bc_mp,
287 cur->bc_ag.pag->pag_agno, error, _RET_IP_);
288 return error;
289}
290
291/*
292 * Adjusting the Reference Count
293 *
294 * As stated elsewhere, the reference count btree (refcbt) stores
295 * >1 reference counts for extents of physical blocks. In this
296 * operation, we're either raising or lowering the reference count of
297 * some subrange stored in the tree:
298 *
299 * <------ adjustment range ------>
300 * ----+ +---+-----+ +--+--------+---------
301 * 2 | | 3 | 4 | |17| 55 | 10
302 * ----+ +---+-----+ +--+--------+---------
303 * X axis is physical blocks number;
304 * reference counts are the numbers inside the rectangles
305 *
306 * The first thing we need to do is to ensure that there are no
307 * refcount extents crossing either boundary of the range to be
308 * adjusted. For any extent that does cross a boundary, split it into
309 * two extents so that we can increment the refcount of one of the
310 * pieces later:
311 *
312 * <------ adjustment range ------>
313 * ----+ +---+-----+ +--+--------+----+----
314 * 2 | | 3 | 2 | |17| 55 | 10 | 10
315 * ----+ +---+-----+ +--+--------+----+----
316 *
317 * For this next step, let's assume that all the physical blocks in
318 * the adjustment range are mapped to a file and are therefore in use
319 * at least once. Therefore, we can infer that any gap in the
320 * refcount tree within the adjustment range represents a physical
321 * extent with refcount == 1:
322 *
323 * <------ adjustment range ------>
324 * ----+---+---+-----+-+--+--------+----+----
325 * 2 |"1"| 3 | 2 |1|17| 55 | 10 | 10
326 * ----+---+---+-----+-+--+--------+----+----
327 * ^
328 *
329 * For each extent that falls within the interval range, figure out
330 * which extent is to the left or the right of that extent. Now we
331 * have a left, current, and right extent. If the new reference count
332 * of the center extent enables us to merge left, center, and right
333 * into one record covering all three, do so. If the center extent is
334 * at the left end of the range, abuts the left extent, and its new
335 * reference count matches the left extent's record, then merge them.
336 * If the center extent is at the right end of the range, abuts the
337 * right extent, and the reference counts match, merge those. In the
338 * example, we can left merge (assuming an increment operation):
339 *
340 * <------ adjustment range ------>
341 * --------+---+-----+-+--+--------+----+----
342 * 2 | 3 | 2 |1|17| 55 | 10 | 10
343 * --------+---+-----+-+--+--------+----+----
344 * ^
345 *
346 * For all other extents within the range, adjust the reference count
347 * or delete it if the refcount falls below 2. If we were
348 * incrementing, the end result looks like this:
349 *
350 * <------ adjustment range ------>
351 * --------+---+-----+-+--+--------+----+----
352 * 2 | 4 | 3 |2|18| 56 | 11 | 10
353 * --------+---+-----+-+--+--------+----+----
354 *
355 * The result of a decrement operation looks as such:
356 *
357 * <------ adjustment range ------>
358 * ----+ +---+ +--+--------+----+----
359 * 2 | | 2 | |16| 54 | 9 | 10
360 * ----+ +---+ +--+--------+----+----
361 * DDDD 111111DD
362 *
363 * The blocks marked "D" are freed; the blocks marked "1" are only
364 * referenced once and therefore the record is removed from the
365 * refcount btree.
366 */
367
368/* Next block after this extent. */
369static inline xfs_agblock_t
370xfs_refc_next(
371 struct xfs_refcount_irec *rc)
372{
373 return rc->rc_startblock + rc->rc_blockcount;
374}
375
376/*
377 * Split a refcount extent that crosses agbno.
378 */
379STATIC int
380xfs_refcount_split_extent(
381 struct xfs_btree_cur *cur,
382 enum xfs_refc_domain domain,
383 xfs_agblock_t agbno,
384 bool *shape_changed)
385{
386 struct xfs_refcount_irec rcext, tmp;
387 int found_rec;
388 int error;
389
390 *shape_changed = false;
391 error = xfs_refcount_lookup_le(cur, domain, agbno, &found_rec);
392 if (error)
393 goto out_error;
394 if (!found_rec)
395 return 0;
396
397 error = xfs_refcount_get_rec(cur, &rcext, &found_rec);
398 if (error)
399 goto out_error;
400 if (XFS_IS_CORRUPT(cur->bc_mp, found_rec != 1)) {
401 error = -EFSCORRUPTED;
402 goto out_error;
403 }
404 if (rcext.rc_domain != domain)
405 return 0;
406 if (rcext.rc_startblock == agbno || xfs_refc_next(&rcext) <= agbno)
407 return 0;
408
409 *shape_changed = true;
410 trace_xfs_refcount_split_extent(cur->bc_mp, cur->bc_ag.pag->pag_agno,
411 &rcext, agbno);
412
413 /* Establish the right extent. */
414 tmp = rcext;
415 tmp.rc_startblock = agbno;
416 tmp.rc_blockcount -= (agbno - rcext.rc_startblock);
417 error = xfs_refcount_update(cur, &tmp);
418 if (error)
419 goto out_error;
420
421 /* Insert the left extent. */
422 tmp = rcext;
423 tmp.rc_blockcount = agbno - rcext.rc_startblock;
424 error = xfs_refcount_insert(cur, &tmp, &found_rec);
425 if (error)
426 goto out_error;
427 if (XFS_IS_CORRUPT(cur->bc_mp, found_rec != 1)) {
428 error = -EFSCORRUPTED;
429 goto out_error;
430 }
431 return error;
432
433out_error:
434 trace_xfs_refcount_split_extent_error(cur->bc_mp,
435 cur->bc_ag.pag->pag_agno, error, _RET_IP_);
436 return error;
437}
438
439/*
440 * Merge the left, center, and right extents.
441 */
442STATIC int
443xfs_refcount_merge_center_extents(
444 struct xfs_btree_cur *cur,
445 struct xfs_refcount_irec *left,
446 struct xfs_refcount_irec *center,
447 struct xfs_refcount_irec *right,
448 unsigned long long extlen,
449 xfs_extlen_t *aglen)
450{
451 int error;
452 int found_rec;
453
454 trace_xfs_refcount_merge_center_extents(cur->bc_mp,
455 cur->bc_ag.pag->pag_agno, left, center, right);
456
457 ASSERT(left->rc_domain == center->rc_domain);
458 ASSERT(right->rc_domain == center->rc_domain);
459
460 /*
461 * Make sure the center and right extents are not in the btree.
462 * If the center extent was synthesized, the first delete call
463 * removes the right extent and we skip the second deletion.
464 * If center and right were in the btree, then the first delete
465 * call removes the center and the second one removes the right
466 * extent.
467 */
468 error = xfs_refcount_lookup_ge(cur, center->rc_domain,
469 center->rc_startblock, &found_rec);
470 if (error)
471 goto out_error;
472 if (XFS_IS_CORRUPT(cur->bc_mp, found_rec != 1)) {
473 error = -EFSCORRUPTED;
474 goto out_error;
475 }
476
477 error = xfs_refcount_delete(cur, &found_rec);
478 if (error)
479 goto out_error;
480 if (XFS_IS_CORRUPT(cur->bc_mp, found_rec != 1)) {
481 error = -EFSCORRUPTED;
482 goto out_error;
483 }
484
485 if (center->rc_refcount > 1) {
486 error = xfs_refcount_delete(cur, &found_rec);
487 if (error)
488 goto out_error;
489 if (XFS_IS_CORRUPT(cur->bc_mp, found_rec != 1)) {
490 error = -EFSCORRUPTED;
491 goto out_error;
492 }
493 }
494
495 /* Enlarge the left extent. */
496 error = xfs_refcount_lookup_le(cur, left->rc_domain,
497 left->rc_startblock, &found_rec);
498 if (error)
499 goto out_error;
500 if (XFS_IS_CORRUPT(cur->bc_mp, found_rec != 1)) {
501 error = -EFSCORRUPTED;
502 goto out_error;
503 }
504
505 left->rc_blockcount = extlen;
506 error = xfs_refcount_update(cur, left);
507 if (error)
508 goto out_error;
509
510 *aglen = 0;
511 return error;
512
513out_error:
514 trace_xfs_refcount_merge_center_extents_error(cur->bc_mp,
515 cur->bc_ag.pag->pag_agno, error, _RET_IP_);
516 return error;
517}
518
519/*
520 * Merge with the left extent.
521 */
522STATIC int
523xfs_refcount_merge_left_extent(
524 struct xfs_btree_cur *cur,
525 struct xfs_refcount_irec *left,
526 struct xfs_refcount_irec *cleft,
527 xfs_agblock_t *agbno,
528 xfs_extlen_t *aglen)
529{
530 int error;
531 int found_rec;
532
533 trace_xfs_refcount_merge_left_extent(cur->bc_mp,
534 cur->bc_ag.pag->pag_agno, left, cleft);
535
536 ASSERT(left->rc_domain == cleft->rc_domain);
537
538 /* If the extent at agbno (cleft) wasn't synthesized, remove it. */
539 if (cleft->rc_refcount > 1) {
540 error = xfs_refcount_lookup_le(cur, cleft->rc_domain,
541 cleft->rc_startblock, &found_rec);
542 if (error)
543 goto out_error;
544 if (XFS_IS_CORRUPT(cur->bc_mp, found_rec != 1)) {
545 error = -EFSCORRUPTED;
546 goto out_error;
547 }
548
549 error = xfs_refcount_delete(cur, &found_rec);
550 if (error)
551 goto out_error;
552 if (XFS_IS_CORRUPT(cur->bc_mp, found_rec != 1)) {
553 error = -EFSCORRUPTED;
554 goto out_error;
555 }
556 }
557
558 /* Enlarge the left extent. */
559 error = xfs_refcount_lookup_le(cur, left->rc_domain,
560 left->rc_startblock, &found_rec);
561 if (error)
562 goto out_error;
563 if (XFS_IS_CORRUPT(cur->bc_mp, found_rec != 1)) {
564 error = -EFSCORRUPTED;
565 goto out_error;
566 }
567
568 left->rc_blockcount += cleft->rc_blockcount;
569 error = xfs_refcount_update(cur, left);
570 if (error)
571 goto out_error;
572
573 *agbno += cleft->rc_blockcount;
574 *aglen -= cleft->rc_blockcount;
575 return error;
576
577out_error:
578 trace_xfs_refcount_merge_left_extent_error(cur->bc_mp,
579 cur->bc_ag.pag->pag_agno, error, _RET_IP_);
580 return error;
581}
582
583/*
584 * Merge with the right extent.
585 */
586STATIC int
587xfs_refcount_merge_right_extent(
588 struct xfs_btree_cur *cur,
589 struct xfs_refcount_irec *right,
590 struct xfs_refcount_irec *cright,
591 xfs_extlen_t *aglen)
592{
593 int error;
594 int found_rec;
595
596 trace_xfs_refcount_merge_right_extent(cur->bc_mp,
597 cur->bc_ag.pag->pag_agno, cright, right);
598
599 ASSERT(right->rc_domain == cright->rc_domain);
600
601 /*
602 * If the extent ending at agbno+aglen (cright) wasn't synthesized,
603 * remove it.
604 */
605 if (cright->rc_refcount > 1) {
606 error = xfs_refcount_lookup_le(cur, cright->rc_domain,
607 cright->rc_startblock, &found_rec);
608 if (error)
609 goto out_error;
610 if (XFS_IS_CORRUPT(cur->bc_mp, found_rec != 1)) {
611 error = -EFSCORRUPTED;
612 goto out_error;
613 }
614
615 error = xfs_refcount_delete(cur, &found_rec);
616 if (error)
617 goto out_error;
618 if (XFS_IS_CORRUPT(cur->bc_mp, found_rec != 1)) {
619 error = -EFSCORRUPTED;
620 goto out_error;
621 }
622 }
623
624 /* Enlarge the right extent. */
625 error = xfs_refcount_lookup_le(cur, right->rc_domain,
626 right->rc_startblock, &found_rec);
627 if (error)
628 goto out_error;
629 if (XFS_IS_CORRUPT(cur->bc_mp, found_rec != 1)) {
630 error = -EFSCORRUPTED;
631 goto out_error;
632 }
633
634 right->rc_startblock -= cright->rc_blockcount;
635 right->rc_blockcount += cright->rc_blockcount;
636 error = xfs_refcount_update(cur, right);
637 if (error)
638 goto out_error;
639
640 *aglen -= cright->rc_blockcount;
641 return error;
642
643out_error:
644 trace_xfs_refcount_merge_right_extent_error(cur->bc_mp,
645 cur->bc_ag.pag->pag_agno, error, _RET_IP_);
646 return error;
647}
648
649/*
650 * Find the left extent and the one after it (cleft). This function assumes
651 * that we've already split any extent crossing agbno.
652 */
653STATIC int
654xfs_refcount_find_left_extents(
655 struct xfs_btree_cur *cur,
656 struct xfs_refcount_irec *left,
657 struct xfs_refcount_irec *cleft,
658 enum xfs_refc_domain domain,
659 xfs_agblock_t agbno,
660 xfs_extlen_t aglen)
661{
662 struct xfs_refcount_irec tmp;
663 int error;
664 int found_rec;
665
666 left->rc_startblock = cleft->rc_startblock = NULLAGBLOCK;
667 error = xfs_refcount_lookup_le(cur, domain, agbno - 1, &found_rec);
668 if (error)
669 goto out_error;
670 if (!found_rec)
671 return 0;
672
673 error = xfs_refcount_get_rec(cur, &tmp, &found_rec);
674 if (error)
675 goto out_error;
676 if (XFS_IS_CORRUPT(cur->bc_mp, found_rec != 1)) {
677 error = -EFSCORRUPTED;
678 goto out_error;
679 }
680
681 if (tmp.rc_domain != domain)
682 return 0;
683 if (xfs_refc_next(&tmp) != agbno)
684 return 0;
685 /* We have a left extent; retrieve (or invent) the next right one */
686 *left = tmp;
687
688 error = xfs_btree_increment(cur, 0, &found_rec);
689 if (error)
690 goto out_error;
691 if (found_rec) {
692 error = xfs_refcount_get_rec(cur, &tmp, &found_rec);
693 if (error)
694 goto out_error;
695 if (XFS_IS_CORRUPT(cur->bc_mp, found_rec != 1)) {
696 error = -EFSCORRUPTED;
697 goto out_error;
698 }
699
700 if (tmp.rc_domain != domain)
701 goto not_found;
702
703 /* if tmp starts at the end of our range, just use that */
704 if (tmp.rc_startblock == agbno)
705 *cleft = tmp;
706 else {
707 /*
708 * There's a gap in the refcntbt at the start of the
709 * range we're interested in (refcount == 1) so
710 * synthesize the implied extent and pass it back.
711 * We assume here that the agbno/aglen range was
712 * passed in from a data fork extent mapping and
713 * therefore is allocated to exactly one owner.
714 */
715 cleft->rc_startblock = agbno;
716 cleft->rc_blockcount = min(aglen,
717 tmp.rc_startblock - agbno);
718 cleft->rc_refcount = 1;
719 cleft->rc_domain = domain;
720 }
721 } else {
722not_found:
723 /*
724 * No extents, so pretend that there's one covering the whole
725 * range.
726 */
727 cleft->rc_startblock = agbno;
728 cleft->rc_blockcount = aglen;
729 cleft->rc_refcount = 1;
730 cleft->rc_domain = domain;
731 }
732 trace_xfs_refcount_find_left_extent(cur->bc_mp, cur->bc_ag.pag->pag_agno,
733 left, cleft, agbno);
734 return error;
735
736out_error:
737 trace_xfs_refcount_find_left_extent_error(cur->bc_mp,
738 cur->bc_ag.pag->pag_agno, error, _RET_IP_);
739 return error;
740}
741
742/*
743 * Find the right extent and the one before it (cright). This function
744 * assumes that we've already split any extents crossing agbno + aglen.
745 */
746STATIC int
747xfs_refcount_find_right_extents(
748 struct xfs_btree_cur *cur,
749 struct xfs_refcount_irec *right,
750 struct xfs_refcount_irec *cright,
751 enum xfs_refc_domain domain,
752 xfs_agblock_t agbno,
753 xfs_extlen_t aglen)
754{
755 struct xfs_refcount_irec tmp;
756 int error;
757 int found_rec;
758
759 right->rc_startblock = cright->rc_startblock = NULLAGBLOCK;
760 error = xfs_refcount_lookup_ge(cur, domain, agbno + aglen, &found_rec);
761 if (error)
762 goto out_error;
763 if (!found_rec)
764 return 0;
765
766 error = xfs_refcount_get_rec(cur, &tmp, &found_rec);
767 if (error)
768 goto out_error;
769 if (XFS_IS_CORRUPT(cur->bc_mp, found_rec != 1)) {
770 error = -EFSCORRUPTED;
771 goto out_error;
772 }
773
774 if (tmp.rc_domain != domain)
775 return 0;
776 if (tmp.rc_startblock != agbno + aglen)
777 return 0;
778 /* We have a right extent; retrieve (or invent) the next left one */
779 *right = tmp;
780
781 error = xfs_btree_decrement(cur, 0, &found_rec);
782 if (error)
783 goto out_error;
784 if (found_rec) {
785 error = xfs_refcount_get_rec(cur, &tmp, &found_rec);
786 if (error)
787 goto out_error;
788 if (XFS_IS_CORRUPT(cur->bc_mp, found_rec != 1)) {
789 error = -EFSCORRUPTED;
790 goto out_error;
791 }
792
793 if (tmp.rc_domain != domain)
794 goto not_found;
795
796 /* if tmp ends at the end of our range, just use that */
797 if (xfs_refc_next(&tmp) == agbno + aglen)
798 *cright = tmp;
799 else {
800 /*
801 * There's a gap in the refcntbt at the end of the
802 * range we're interested in (refcount == 1) so
803 * create the implied extent and pass it back.
804 * We assume here that the agbno/aglen range was
805 * passed in from a data fork extent mapping and
806 * therefore is allocated to exactly one owner.
807 */
808 cright->rc_startblock = max(agbno, xfs_refc_next(&tmp));
809 cright->rc_blockcount = right->rc_startblock -
810 cright->rc_startblock;
811 cright->rc_refcount = 1;
812 cright->rc_domain = domain;
813 }
814 } else {
815not_found:
816 /*
817 * No extents, so pretend that there's one covering the whole
818 * range.
819 */
820 cright->rc_startblock = agbno;
821 cright->rc_blockcount = aglen;
822 cright->rc_refcount = 1;
823 cright->rc_domain = domain;
824 }
825 trace_xfs_refcount_find_right_extent(cur->bc_mp, cur->bc_ag.pag->pag_agno,
826 cright, right, agbno + aglen);
827 return error;
828
829out_error:
830 trace_xfs_refcount_find_right_extent_error(cur->bc_mp,
831 cur->bc_ag.pag->pag_agno, error, _RET_IP_);
832 return error;
833}
834
835/* Is this extent valid? */
836static inline bool
837xfs_refc_valid(
838 const struct xfs_refcount_irec *rc)
839{
840 return rc->rc_startblock != NULLAGBLOCK;
841}
842
843static inline xfs_nlink_t
844xfs_refc_merge_refcount(
845 const struct xfs_refcount_irec *irec,
846 enum xfs_refc_adjust_op adjust)
847{
848 /* Once a record hits MAXREFCOUNT, it is pinned there forever */
849 if (irec->rc_refcount == MAXREFCOUNT)
850 return MAXREFCOUNT;
851 return irec->rc_refcount + adjust;
852}
853
854static inline bool
855xfs_refc_want_merge_center(
856 const struct xfs_refcount_irec *left,
857 const struct xfs_refcount_irec *cleft,
858 const struct xfs_refcount_irec *cright,
859 const struct xfs_refcount_irec *right,
860 bool cleft_is_cright,
861 enum xfs_refc_adjust_op adjust,
862 unsigned long long *ulenp)
863{
864 unsigned long long ulen = left->rc_blockcount;
865 xfs_nlink_t new_refcount;
866
867 /*
868 * To merge with a center record, both shoulder records must be
869 * adjacent to the record we want to adjust. This is only true if
870 * find_left and find_right made all four records valid.
871 */
872 if (!xfs_refc_valid(left) || !xfs_refc_valid(right) ||
873 !xfs_refc_valid(cleft) || !xfs_refc_valid(cright))
874 return false;
875
876 /* There must only be one record for the entire range. */
877 if (!cleft_is_cright)
878 return false;
879
880 /* The shoulder record refcounts must match the new refcount. */
881 new_refcount = xfs_refc_merge_refcount(cleft, adjust);
882 if (left->rc_refcount != new_refcount)
883 return false;
884 if (right->rc_refcount != new_refcount)
885 return false;
886
887 /*
888 * The new record cannot exceed the max length. ulen is a ULL as the
889 * individual record block counts can be up to (u32 - 1) in length
890 * hence we need to catch u32 addition overflows here.
891 */
892 ulen += cleft->rc_blockcount + right->rc_blockcount;
893 if (ulen >= MAXREFCEXTLEN)
894 return false;
895
896 *ulenp = ulen;
897 return true;
898}
899
900static inline bool
901xfs_refc_want_merge_left(
902 const struct xfs_refcount_irec *left,
903 const struct xfs_refcount_irec *cleft,
904 enum xfs_refc_adjust_op adjust)
905{
906 unsigned long long ulen = left->rc_blockcount;
907 xfs_nlink_t new_refcount;
908
909 /*
910 * For a left merge, the left shoulder record must be adjacent to the
911 * start of the range. If this is true, find_left made left and cleft
912 * contain valid contents.
913 */
914 if (!xfs_refc_valid(left) || !xfs_refc_valid(cleft))
915 return false;
916
917 /* Left shoulder record refcount must match the new refcount. */
918 new_refcount = xfs_refc_merge_refcount(cleft, adjust);
919 if (left->rc_refcount != new_refcount)
920 return false;
921
922 /*
923 * The new record cannot exceed the max length. ulen is a ULL as the
924 * individual record block counts can be up to (u32 - 1) in length
925 * hence we need to catch u32 addition overflows here.
926 */
927 ulen += cleft->rc_blockcount;
928 if (ulen >= MAXREFCEXTLEN)
929 return false;
930
931 return true;
932}
933
934static inline bool
935xfs_refc_want_merge_right(
936 const struct xfs_refcount_irec *cright,
937 const struct xfs_refcount_irec *right,
938 enum xfs_refc_adjust_op adjust)
939{
940 unsigned long long ulen = right->rc_blockcount;
941 xfs_nlink_t new_refcount;
942
943 /*
944 * For a right merge, the right shoulder record must be adjacent to the
945 * end of the range. If this is true, find_right made cright and right
946 * contain valid contents.
947 */
948 if (!xfs_refc_valid(right) || !xfs_refc_valid(cright))
949 return false;
950
951 /* Right shoulder record refcount must match the new refcount. */
952 new_refcount = xfs_refc_merge_refcount(cright, adjust);
953 if (right->rc_refcount != new_refcount)
954 return false;
955
956 /*
957 * The new record cannot exceed the max length. ulen is a ULL as the
958 * individual record block counts can be up to (u32 - 1) in length
959 * hence we need to catch u32 addition overflows here.
960 */
961 ulen += cright->rc_blockcount;
962 if (ulen >= MAXREFCEXTLEN)
963 return false;
964
965 return true;
966}
967
968/*
969 * Try to merge with any extents on the boundaries of the adjustment range.
970 */
971STATIC int
972xfs_refcount_merge_extents(
973 struct xfs_btree_cur *cur,
974 enum xfs_refc_domain domain,
975 xfs_agblock_t *agbno,
976 xfs_extlen_t *aglen,
977 enum xfs_refc_adjust_op adjust,
978 bool *shape_changed)
979{
980 struct xfs_refcount_irec left = {0}, cleft = {0};
981 struct xfs_refcount_irec cright = {0}, right = {0};
982 int error;
983 unsigned long long ulen;
984 bool cequal;
985
986 *shape_changed = false;
987 /*
988 * Find the extent just below agbno [left], just above agbno [cleft],
989 * just below (agbno + aglen) [cright], and just above (agbno + aglen)
990 * [right].
991 */
992 error = xfs_refcount_find_left_extents(cur, &left, &cleft, domain,
993 *agbno, *aglen);
994 if (error)
995 return error;
996 error = xfs_refcount_find_right_extents(cur, &right, &cright, domain,
997 *agbno, *aglen);
998 if (error)
999 return error;
1000
1001 /* No left or right extent to merge; exit. */
1002 if (!xfs_refc_valid(&left) && !xfs_refc_valid(&right))
1003 return 0;
1004
1005 cequal = (cleft.rc_startblock == cright.rc_startblock) &&
1006 (cleft.rc_blockcount == cright.rc_blockcount);
1007
1008 /* Try to merge left, cleft, and right. cleft must == cright. */
1009 if (xfs_refc_want_merge_center(&left, &cleft, &cright, &right, cequal,
1010 adjust, &ulen)) {
1011 *shape_changed = true;
1012 return xfs_refcount_merge_center_extents(cur, &left, &cleft,
1013 &right, ulen, aglen);
1014 }
1015
1016 /* Try to merge left and cleft. */
1017 if (xfs_refc_want_merge_left(&left, &cleft, adjust)) {
1018 *shape_changed = true;
1019 error = xfs_refcount_merge_left_extent(cur, &left, &cleft,
1020 agbno, aglen);
1021 if (error)
1022 return error;
1023
1024 /*
1025 * If we just merged left + cleft and cleft == cright,
1026 * we no longer have a cright to merge with right. We're done.
1027 */
1028 if (cequal)
1029 return 0;
1030 }
1031
1032 /* Try to merge cright and right. */
1033 if (xfs_refc_want_merge_right(&cright, &right, adjust)) {
1034 *shape_changed = true;
1035 return xfs_refcount_merge_right_extent(cur, &right, &cright,
1036 aglen);
1037 }
1038
1039 return 0;
1040}
1041
1042/*
1043 * XXX: This is a pretty hand-wavy estimate. The penalty for guessing
1044 * true incorrectly is a shutdown FS; the penalty for guessing false
1045 * incorrectly is more transaction rolls than might be necessary.
1046 * Be conservative here.
1047 */
1048static bool
1049xfs_refcount_still_have_space(
1050 struct xfs_btree_cur *cur)
1051{
1052 unsigned long overhead;
1053
1054 /*
1055 * Worst case estimate: full splits of the free space and rmap btrees
1056 * to handle each of the shape changes to the refcount btree.
1057 */
1058 overhead = xfs_allocfree_block_count(cur->bc_mp,
1059 cur->bc_ag.refc.shape_changes);
1060 overhead += cur->bc_mp->m_refc_maxlevels;
1061 overhead *= cur->bc_mp->m_sb.sb_blocksize;
1062
1063 /*
1064 * Only allow 2 refcount extent updates per transaction if the
1065 * refcount continue update "error" has been injected.
1066 */
1067 if (cur->bc_ag.refc.nr_ops > 2 &&
1068 XFS_TEST_ERROR(false, cur->bc_mp,
1069 XFS_ERRTAG_REFCOUNT_CONTINUE_UPDATE))
1070 return false;
1071
1072 if (cur->bc_ag.refc.nr_ops == 0)
1073 return true;
1074 else if (overhead > cur->bc_tp->t_log_res)
1075 return false;
1076 return cur->bc_tp->t_log_res - overhead >
1077 cur->bc_ag.refc.nr_ops * XFS_REFCOUNT_ITEM_OVERHEAD;
1078}
1079
1080/*
1081 * Adjust the refcounts of middle extents. At this point we should have
1082 * split extents that crossed the adjustment range; merged with adjacent
1083 * extents; and updated agbno/aglen to reflect the merges. Therefore,
1084 * all we have to do is update the extents inside [agbno, agbno + aglen].
1085 */
1086STATIC int
1087xfs_refcount_adjust_extents(
1088 struct xfs_btree_cur *cur,
1089 xfs_agblock_t *agbno,
1090 xfs_extlen_t *aglen,
1091 enum xfs_refc_adjust_op adj)
1092{
1093 struct xfs_refcount_irec ext, tmp;
1094 int error;
1095 int found_rec, found_tmp;
1096 xfs_fsblock_t fsbno;
1097
1098 /* Merging did all the work already. */
1099 if (*aglen == 0)
1100 return 0;
1101
1102 error = xfs_refcount_lookup_ge(cur, XFS_REFC_DOMAIN_SHARED, *agbno,
1103 &found_rec);
1104 if (error)
1105 goto out_error;
1106
1107 while (*aglen > 0 && xfs_refcount_still_have_space(cur)) {
1108 error = xfs_refcount_get_rec(cur, &ext, &found_rec);
1109 if (error)
1110 goto out_error;
1111 if (!found_rec || ext.rc_domain != XFS_REFC_DOMAIN_SHARED) {
1112 ext.rc_startblock = cur->bc_mp->m_sb.sb_agblocks;
1113 ext.rc_blockcount = 0;
1114 ext.rc_refcount = 0;
1115 ext.rc_domain = XFS_REFC_DOMAIN_SHARED;
1116 }
1117
1118 /*
1119 * Deal with a hole in the refcount tree; if a file maps to
1120 * these blocks and there's no refcountbt record, pretend that
1121 * there is one with refcount == 1.
1122 */
1123 if (ext.rc_startblock != *agbno) {
1124 tmp.rc_startblock = *agbno;
1125 tmp.rc_blockcount = min(*aglen,
1126 ext.rc_startblock - *agbno);
1127 tmp.rc_refcount = 1 + adj;
1128 tmp.rc_domain = XFS_REFC_DOMAIN_SHARED;
1129
1130 trace_xfs_refcount_modify_extent(cur->bc_mp,
1131 cur->bc_ag.pag->pag_agno, &tmp);
1132
1133 /*
1134 * Either cover the hole (increment) or
1135 * delete the range (decrement).
1136 */
1137 cur->bc_ag.refc.nr_ops++;
1138 if (tmp.rc_refcount) {
1139 error = xfs_refcount_insert(cur, &tmp,
1140 &found_tmp);
1141 if (error)
1142 goto out_error;
1143 if (XFS_IS_CORRUPT(cur->bc_mp,
1144 found_tmp != 1)) {
1145 error = -EFSCORRUPTED;
1146 goto out_error;
1147 }
1148 } else {
1149 fsbno = XFS_AGB_TO_FSB(cur->bc_mp,
1150 cur->bc_ag.pag->pag_agno,
1151 tmp.rc_startblock);
1152 error = xfs_free_extent_later(cur->bc_tp, fsbno,
1153 tmp.rc_blockcount, NULL,
1154 XFS_AG_RESV_NONE, false);
1155 if (error)
1156 goto out_error;
1157 }
1158
1159 (*agbno) += tmp.rc_blockcount;
1160 (*aglen) -= tmp.rc_blockcount;
1161
1162 /* Stop if there's nothing left to modify */
1163 if (*aglen == 0 || !xfs_refcount_still_have_space(cur))
1164 break;
1165
1166 /* Move the cursor to the start of ext. */
1167 error = xfs_refcount_lookup_ge(cur,
1168 XFS_REFC_DOMAIN_SHARED, *agbno,
1169 &found_rec);
1170 if (error)
1171 goto out_error;
1172 }
1173
1174 /*
1175 * A previous step trimmed agbno/aglen such that the end of the
1176 * range would not be in the middle of the record. If this is
1177 * no longer the case, something is seriously wrong with the
1178 * btree. Make sure we never feed the synthesized record into
1179 * the processing loop below.
1180 */
1181 if (XFS_IS_CORRUPT(cur->bc_mp, ext.rc_blockcount == 0) ||
1182 XFS_IS_CORRUPT(cur->bc_mp, ext.rc_blockcount > *aglen)) {
1183 error = -EFSCORRUPTED;
1184 goto out_error;
1185 }
1186
1187 /*
1188 * Adjust the reference count and either update the tree
1189 * (incr) or free the blocks (decr).
1190 */
1191 if (ext.rc_refcount == MAXREFCOUNT)
1192 goto skip;
1193 ext.rc_refcount += adj;
1194 trace_xfs_refcount_modify_extent(cur->bc_mp,
1195 cur->bc_ag.pag->pag_agno, &ext);
1196 cur->bc_ag.refc.nr_ops++;
1197 if (ext.rc_refcount > 1) {
1198 error = xfs_refcount_update(cur, &ext);
1199 if (error)
1200 goto out_error;
1201 } else if (ext.rc_refcount == 1) {
1202 error = xfs_refcount_delete(cur, &found_rec);
1203 if (error)
1204 goto out_error;
1205 if (XFS_IS_CORRUPT(cur->bc_mp, found_rec != 1)) {
1206 error = -EFSCORRUPTED;
1207 goto out_error;
1208 }
1209 goto advloop;
1210 } else {
1211 fsbno = XFS_AGB_TO_FSB(cur->bc_mp,
1212 cur->bc_ag.pag->pag_agno,
1213 ext.rc_startblock);
1214 error = xfs_free_extent_later(cur->bc_tp, fsbno,
1215 ext.rc_blockcount, NULL,
1216 XFS_AG_RESV_NONE, false);
1217 if (error)
1218 goto out_error;
1219 }
1220
1221skip:
1222 error = xfs_btree_increment(cur, 0, &found_rec);
1223 if (error)
1224 goto out_error;
1225
1226advloop:
1227 (*agbno) += ext.rc_blockcount;
1228 (*aglen) -= ext.rc_blockcount;
1229 }
1230
1231 return error;
1232out_error:
1233 trace_xfs_refcount_modify_extent_error(cur->bc_mp,
1234 cur->bc_ag.pag->pag_agno, error, _RET_IP_);
1235 return error;
1236}
1237
1238/* Adjust the reference count of a range of AG blocks. */
1239STATIC int
1240xfs_refcount_adjust(
1241 struct xfs_btree_cur *cur,
1242 xfs_agblock_t *agbno,
1243 xfs_extlen_t *aglen,
1244 enum xfs_refc_adjust_op adj)
1245{
1246 bool shape_changed;
1247 int shape_changes = 0;
1248 int error;
1249
1250 if (adj == XFS_REFCOUNT_ADJUST_INCREASE)
1251 trace_xfs_refcount_increase(cur->bc_mp,
1252 cur->bc_ag.pag->pag_agno, *agbno, *aglen);
1253 else
1254 trace_xfs_refcount_decrease(cur->bc_mp,
1255 cur->bc_ag.pag->pag_agno, *agbno, *aglen);
1256
1257 /*
1258 * Ensure that no rcextents cross the boundary of the adjustment range.
1259 */
1260 error = xfs_refcount_split_extent(cur, XFS_REFC_DOMAIN_SHARED,
1261 *agbno, &shape_changed);
1262 if (error)
1263 goto out_error;
1264 if (shape_changed)
1265 shape_changes++;
1266
1267 error = xfs_refcount_split_extent(cur, XFS_REFC_DOMAIN_SHARED,
1268 *agbno + *aglen, &shape_changed);
1269 if (error)
1270 goto out_error;
1271 if (shape_changed)
1272 shape_changes++;
1273
1274 /*
1275 * Try to merge with the left or right extents of the range.
1276 */
1277 error = xfs_refcount_merge_extents(cur, XFS_REFC_DOMAIN_SHARED,
1278 agbno, aglen, adj, &shape_changed);
1279 if (error)
1280 goto out_error;
1281 if (shape_changed)
1282 shape_changes++;
1283 if (shape_changes)
1284 cur->bc_ag.refc.shape_changes++;
1285
1286 /* Now that we've taken care of the ends, adjust the middle extents */
1287 error = xfs_refcount_adjust_extents(cur, agbno, aglen, adj);
1288 if (error)
1289 goto out_error;
1290
1291 return 0;
1292
1293out_error:
1294 trace_xfs_refcount_adjust_error(cur->bc_mp, cur->bc_ag.pag->pag_agno,
1295 error, _RET_IP_);
1296 return error;
1297}
1298
1299/* Clean up after calling xfs_refcount_finish_one. */
1300void
1301xfs_refcount_finish_one_cleanup(
1302 struct xfs_trans *tp,
1303 struct xfs_btree_cur *rcur,
1304 int error)
1305{
1306 struct xfs_buf *agbp;
1307
1308 if (rcur == NULL)
1309 return;
1310 agbp = rcur->bc_ag.agbp;
1311 xfs_btree_del_cursor(rcur, error);
1312 if (error)
1313 xfs_trans_brelse(tp, agbp);
1314}
1315
1316/*
1317 * Set up a continuation a deferred refcount operation by updating the intent.
1318 * Checks to make sure we're not going to run off the end of the AG.
1319 */
1320static inline int
1321xfs_refcount_continue_op(
1322 struct xfs_btree_cur *cur,
1323 struct xfs_refcount_intent *ri,
1324 xfs_agblock_t new_agbno)
1325{
1326 struct xfs_mount *mp = cur->bc_mp;
1327 struct xfs_perag *pag = cur->bc_ag.pag;
1328
1329 if (XFS_IS_CORRUPT(mp, !xfs_verify_agbext(pag, new_agbno,
1330 ri->ri_blockcount)))
1331 return -EFSCORRUPTED;
1332
1333 ri->ri_startblock = XFS_AGB_TO_FSB(mp, pag->pag_agno, new_agbno);
1334
1335 ASSERT(xfs_verify_fsbext(mp, ri->ri_startblock, ri->ri_blockcount));
1336 ASSERT(pag->pag_agno == XFS_FSB_TO_AGNO(mp, ri->ri_startblock));
1337
1338 return 0;
1339}
1340
1341/*
1342 * Process one of the deferred refcount operations. We pass back the
1343 * btree cursor to maintain our lock on the btree between calls.
1344 * This saves time and eliminates a buffer deadlock between the
1345 * superblock and the AGF because we'll always grab them in the same
1346 * order.
1347 */
1348int
1349xfs_refcount_finish_one(
1350 struct xfs_trans *tp,
1351 struct xfs_refcount_intent *ri,
1352 struct xfs_btree_cur **pcur)
1353{
1354 struct xfs_mount *mp = tp->t_mountp;
1355 struct xfs_btree_cur *rcur;
1356 struct xfs_buf *agbp = NULL;
1357 int error = 0;
1358 xfs_agblock_t bno;
1359 unsigned long nr_ops = 0;
1360 int shape_changes = 0;
1361
1362 bno = XFS_FSB_TO_AGBNO(mp, ri->ri_startblock);
1363
1364 trace_xfs_refcount_deferred(mp, XFS_FSB_TO_AGNO(mp, ri->ri_startblock),
1365 ri->ri_type, XFS_FSB_TO_AGBNO(mp, ri->ri_startblock),
1366 ri->ri_blockcount);
1367
1368 if (XFS_TEST_ERROR(false, mp, XFS_ERRTAG_REFCOUNT_FINISH_ONE))
1369 return -EIO;
1370
1371 /*
1372 * If we haven't gotten a cursor or the cursor AG doesn't match
1373 * the startblock, get one now.
1374 */
1375 rcur = *pcur;
1376 if (rcur != NULL && rcur->bc_ag.pag != ri->ri_pag) {
1377 nr_ops = rcur->bc_ag.refc.nr_ops;
1378 shape_changes = rcur->bc_ag.refc.shape_changes;
1379 xfs_refcount_finish_one_cleanup(tp, rcur, 0);
1380 rcur = NULL;
1381 *pcur = NULL;
1382 }
1383 if (rcur == NULL) {
1384 error = xfs_alloc_read_agf(ri->ri_pag, tp,
1385 XFS_ALLOC_FLAG_FREEING, &agbp);
1386 if (error)
1387 return error;
1388
1389 rcur = xfs_refcountbt_init_cursor(mp, tp, agbp, ri->ri_pag);
1390 rcur->bc_ag.refc.nr_ops = nr_ops;
1391 rcur->bc_ag.refc.shape_changes = shape_changes;
1392 }
1393 *pcur = rcur;
1394
1395 switch (ri->ri_type) {
1396 case XFS_REFCOUNT_INCREASE:
1397 error = xfs_refcount_adjust(rcur, &bno, &ri->ri_blockcount,
1398 XFS_REFCOUNT_ADJUST_INCREASE);
1399 if (error)
1400 return error;
1401 if (ri->ri_blockcount > 0)
1402 error = xfs_refcount_continue_op(rcur, ri, bno);
1403 break;
1404 case XFS_REFCOUNT_DECREASE:
1405 error = xfs_refcount_adjust(rcur, &bno, &ri->ri_blockcount,
1406 XFS_REFCOUNT_ADJUST_DECREASE);
1407 if (error)
1408 return error;
1409 if (ri->ri_blockcount > 0)
1410 error = xfs_refcount_continue_op(rcur, ri, bno);
1411 break;
1412 case XFS_REFCOUNT_ALLOC_COW:
1413 error = __xfs_refcount_cow_alloc(rcur, bno, ri->ri_blockcount);
1414 if (error)
1415 return error;
1416 ri->ri_blockcount = 0;
1417 break;
1418 case XFS_REFCOUNT_FREE_COW:
1419 error = __xfs_refcount_cow_free(rcur, bno, ri->ri_blockcount);
1420 if (error)
1421 return error;
1422 ri->ri_blockcount = 0;
1423 break;
1424 default:
1425 ASSERT(0);
1426 return -EFSCORRUPTED;
1427 }
1428 if (!error && ri->ri_blockcount > 0)
1429 trace_xfs_refcount_finish_one_leftover(mp, ri->ri_pag->pag_agno,
1430 ri->ri_type, bno, ri->ri_blockcount);
1431 return error;
1432}
1433
1434/*
1435 * Record a refcount intent for later processing.
1436 */
1437static void
1438__xfs_refcount_add(
1439 struct xfs_trans *tp,
1440 enum xfs_refcount_intent_type type,
1441 xfs_fsblock_t startblock,
1442 xfs_extlen_t blockcount)
1443{
1444 struct xfs_refcount_intent *ri;
1445
1446 trace_xfs_refcount_defer(tp->t_mountp,
1447 XFS_FSB_TO_AGNO(tp->t_mountp, startblock),
1448 type, XFS_FSB_TO_AGBNO(tp->t_mountp, startblock),
1449 blockcount);
1450
1451 ri = kmem_cache_alloc(xfs_refcount_intent_cache,
1452 GFP_NOFS | __GFP_NOFAIL);
1453 INIT_LIST_HEAD(&ri->ri_list);
1454 ri->ri_type = type;
1455 ri->ri_startblock = startblock;
1456 ri->ri_blockcount = blockcount;
1457
1458 xfs_refcount_update_get_group(tp->t_mountp, ri);
1459 xfs_defer_add(tp, &ri->ri_list, &xfs_refcount_update_defer_type);
1460}
1461
1462/*
1463 * Increase the reference count of the blocks backing a file's extent.
1464 */
1465void
1466xfs_refcount_increase_extent(
1467 struct xfs_trans *tp,
1468 struct xfs_bmbt_irec *PREV)
1469{
1470 if (!xfs_has_reflink(tp->t_mountp))
1471 return;
1472
1473 __xfs_refcount_add(tp, XFS_REFCOUNT_INCREASE, PREV->br_startblock,
1474 PREV->br_blockcount);
1475}
1476
1477/*
1478 * Decrease the reference count of the blocks backing a file's extent.
1479 */
1480void
1481xfs_refcount_decrease_extent(
1482 struct xfs_trans *tp,
1483 struct xfs_bmbt_irec *PREV)
1484{
1485 if (!xfs_has_reflink(tp->t_mountp))
1486 return;
1487
1488 __xfs_refcount_add(tp, XFS_REFCOUNT_DECREASE, PREV->br_startblock,
1489 PREV->br_blockcount);
1490}
1491
1492/*
1493 * Given an AG extent, find the lowest-numbered run of shared blocks
1494 * within that range and return the range in fbno/flen. If
1495 * find_end_of_shared is set, return the longest contiguous extent of
1496 * shared blocks; if not, just return the first extent we find. If no
1497 * shared blocks are found, fbno and flen will be set to NULLAGBLOCK
1498 * and 0, respectively.
1499 */
1500int
1501xfs_refcount_find_shared(
1502 struct xfs_btree_cur *cur,
1503 xfs_agblock_t agbno,
1504 xfs_extlen_t aglen,
1505 xfs_agblock_t *fbno,
1506 xfs_extlen_t *flen,
1507 bool find_end_of_shared)
1508{
1509 struct xfs_refcount_irec tmp;
1510 int i;
1511 int have;
1512 int error;
1513
1514 trace_xfs_refcount_find_shared(cur->bc_mp, cur->bc_ag.pag->pag_agno,
1515 agbno, aglen);
1516
1517 /* By default, skip the whole range */
1518 *fbno = NULLAGBLOCK;
1519 *flen = 0;
1520
1521 /* Try to find a refcount extent that crosses the start */
1522 error = xfs_refcount_lookup_le(cur, XFS_REFC_DOMAIN_SHARED, agbno,
1523 &have);
1524 if (error)
1525 goto out_error;
1526 if (!have) {
1527 /* No left extent, look at the next one */
1528 error = xfs_btree_increment(cur, 0, &have);
1529 if (error)
1530 goto out_error;
1531 if (!have)
1532 goto done;
1533 }
1534 error = xfs_refcount_get_rec(cur, &tmp, &i);
1535 if (error)
1536 goto out_error;
1537 if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
1538 error = -EFSCORRUPTED;
1539 goto out_error;
1540 }
1541 if (tmp.rc_domain != XFS_REFC_DOMAIN_SHARED)
1542 goto done;
1543
1544 /* If the extent ends before the start, look at the next one */
1545 if (tmp.rc_startblock + tmp.rc_blockcount <= agbno) {
1546 error = xfs_btree_increment(cur, 0, &have);
1547 if (error)
1548 goto out_error;
1549 if (!have)
1550 goto done;
1551 error = xfs_refcount_get_rec(cur, &tmp, &i);
1552 if (error)
1553 goto out_error;
1554 if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
1555 error = -EFSCORRUPTED;
1556 goto out_error;
1557 }
1558 if (tmp.rc_domain != XFS_REFC_DOMAIN_SHARED)
1559 goto done;
1560 }
1561
1562 /* If the extent starts after the range we want, bail out */
1563 if (tmp.rc_startblock >= agbno + aglen)
1564 goto done;
1565
1566 /* We found the start of a shared extent! */
1567 if (tmp.rc_startblock < agbno) {
1568 tmp.rc_blockcount -= (agbno - tmp.rc_startblock);
1569 tmp.rc_startblock = agbno;
1570 }
1571
1572 *fbno = tmp.rc_startblock;
1573 *flen = min(tmp.rc_blockcount, agbno + aglen - *fbno);
1574 if (!find_end_of_shared)
1575 goto done;
1576
1577 /* Otherwise, find the end of this shared extent */
1578 while (*fbno + *flen < agbno + aglen) {
1579 error = xfs_btree_increment(cur, 0, &have);
1580 if (error)
1581 goto out_error;
1582 if (!have)
1583 break;
1584 error = xfs_refcount_get_rec(cur, &tmp, &i);
1585 if (error)
1586 goto out_error;
1587 if (XFS_IS_CORRUPT(cur->bc_mp, i != 1)) {
1588 error = -EFSCORRUPTED;
1589 goto out_error;
1590 }
1591 if (tmp.rc_domain != XFS_REFC_DOMAIN_SHARED ||
1592 tmp.rc_startblock >= agbno + aglen ||
1593 tmp.rc_startblock != *fbno + *flen)
1594 break;
1595 *flen = min(*flen + tmp.rc_blockcount, agbno + aglen - *fbno);
1596 }
1597
1598done:
1599 trace_xfs_refcount_find_shared_result(cur->bc_mp,
1600 cur->bc_ag.pag->pag_agno, *fbno, *flen);
1601
1602out_error:
1603 if (error)
1604 trace_xfs_refcount_find_shared_error(cur->bc_mp,
1605 cur->bc_ag.pag->pag_agno, error, _RET_IP_);
1606 return error;
1607}
1608
1609/*
1610 * Recovering CoW Blocks After a Crash
1611 *
1612 * Due to the way that the copy on write mechanism works, there's a window of
1613 * opportunity in which we can lose track of allocated blocks during a crash.
1614 * Because CoW uses delayed allocation in the in-core CoW fork, writeback
1615 * causes blocks to be allocated and stored in the CoW fork. The blocks are
1616 * no longer in the free space btree but are not otherwise recorded anywhere
1617 * until the write completes and the blocks are mapped into the file. A crash
1618 * in between allocation and remapping results in the replacement blocks being
1619 * lost. This situation is exacerbated by the CoW extent size hint because
1620 * allocations can hang around for long time.
1621 *
1622 * However, there is a place where we can record these allocations before they
1623 * become mappings -- the reference count btree. The btree does not record
1624 * extents with refcount == 1, so we can record allocations with a refcount of
1625 * 1. Blocks being used for CoW writeout cannot be shared, so there should be
1626 * no conflict with shared block records. These mappings should be created
1627 * when we allocate blocks to the CoW fork and deleted when they're removed
1628 * from the CoW fork.
1629 *
1630 * Minor nit: records for in-progress CoW allocations and records for shared
1631 * extents must never be merged, to preserve the property that (except for CoW
1632 * allocations) there are no refcount btree entries with refcount == 1. The
1633 * only time this could potentially happen is when unsharing a block that's
1634 * adjacent to CoW allocations, so we must be careful to avoid this.
1635 *
1636 * At mount time we recover lost CoW allocations by searching the refcount
1637 * btree for these refcount == 1 mappings. These represent CoW allocations
1638 * that were in progress at the time the filesystem went down, so we can free
1639 * them to get the space back.
1640 *
1641 * This mechanism is superior to creating EFIs for unmapped CoW extents for
1642 * several reasons -- first, EFIs pin the tail of the log and would have to be
1643 * periodically relogged to avoid filling up the log. Second, CoW completions
1644 * will have to file an EFD and create new EFIs for whatever remains in the
1645 * CoW fork; this partially takes care of (1) but extent-size reservations
1646 * will have to periodically relog even if there's no writeout in progress.
1647 * This can happen if the CoW extent size hint is set, which you really want.
1648 * Third, EFIs cannot currently be automatically relogged into newer
1649 * transactions to advance the log tail. Fourth, stuffing the log full of
1650 * EFIs places an upper bound on the number of CoW allocations that can be
1651 * held filesystem-wide at any given time. Recording them in the refcount
1652 * btree doesn't require us to maintain any state in memory and doesn't pin
1653 * the log.
1654 */
1655/*
1656 * Adjust the refcounts of CoW allocations. These allocations are "magic"
1657 * in that they're not referenced anywhere else in the filesystem, so we
1658 * stash them in the refcount btree with a refcount of 1 until either file
1659 * remapping (or CoW cancellation) happens.
1660 */
1661STATIC int
1662xfs_refcount_adjust_cow_extents(
1663 struct xfs_btree_cur *cur,
1664 xfs_agblock_t agbno,
1665 xfs_extlen_t aglen,
1666 enum xfs_refc_adjust_op adj)
1667{
1668 struct xfs_refcount_irec ext, tmp;
1669 int error;
1670 int found_rec, found_tmp;
1671
1672 if (aglen == 0)
1673 return 0;
1674
1675 /* Find any overlapping refcount records */
1676 error = xfs_refcount_lookup_ge(cur, XFS_REFC_DOMAIN_COW, agbno,
1677 &found_rec);
1678 if (error)
1679 goto out_error;
1680 error = xfs_refcount_get_rec(cur, &ext, &found_rec);
1681 if (error)
1682 goto out_error;
1683 if (XFS_IS_CORRUPT(cur->bc_mp, found_rec &&
1684 ext.rc_domain != XFS_REFC_DOMAIN_COW)) {
1685 error = -EFSCORRUPTED;
1686 goto out_error;
1687 }
1688 if (!found_rec) {
1689 ext.rc_startblock = cur->bc_mp->m_sb.sb_agblocks;
1690 ext.rc_blockcount = 0;
1691 ext.rc_refcount = 0;
1692 ext.rc_domain = XFS_REFC_DOMAIN_COW;
1693 }
1694
1695 switch (adj) {
1696 case XFS_REFCOUNT_ADJUST_COW_ALLOC:
1697 /* Adding a CoW reservation, there should be nothing here. */
1698 if (XFS_IS_CORRUPT(cur->bc_mp,
1699 agbno + aglen > ext.rc_startblock)) {
1700 error = -EFSCORRUPTED;
1701 goto out_error;
1702 }
1703
1704 tmp.rc_startblock = agbno;
1705 tmp.rc_blockcount = aglen;
1706 tmp.rc_refcount = 1;
1707 tmp.rc_domain = XFS_REFC_DOMAIN_COW;
1708
1709 trace_xfs_refcount_modify_extent(cur->bc_mp,
1710 cur->bc_ag.pag->pag_agno, &tmp);
1711
1712 error = xfs_refcount_insert(cur, &tmp,
1713 &found_tmp);
1714 if (error)
1715 goto out_error;
1716 if (XFS_IS_CORRUPT(cur->bc_mp, found_tmp != 1)) {
1717 error = -EFSCORRUPTED;
1718 goto out_error;
1719 }
1720 break;
1721 case XFS_REFCOUNT_ADJUST_COW_FREE:
1722 /* Removing a CoW reservation, there should be one extent. */
1723 if (XFS_IS_CORRUPT(cur->bc_mp, ext.rc_startblock != agbno)) {
1724 error = -EFSCORRUPTED;
1725 goto out_error;
1726 }
1727 if (XFS_IS_CORRUPT(cur->bc_mp, ext.rc_blockcount != aglen)) {
1728 error = -EFSCORRUPTED;
1729 goto out_error;
1730 }
1731 if (XFS_IS_CORRUPT(cur->bc_mp, ext.rc_refcount != 1)) {
1732 error = -EFSCORRUPTED;
1733 goto out_error;
1734 }
1735
1736 ext.rc_refcount = 0;
1737 trace_xfs_refcount_modify_extent(cur->bc_mp,
1738 cur->bc_ag.pag->pag_agno, &ext);
1739 error = xfs_refcount_delete(cur, &found_rec);
1740 if (error)
1741 goto out_error;
1742 if (XFS_IS_CORRUPT(cur->bc_mp, found_rec != 1)) {
1743 error = -EFSCORRUPTED;
1744 goto out_error;
1745 }
1746 break;
1747 default:
1748 ASSERT(0);
1749 }
1750
1751 return error;
1752out_error:
1753 trace_xfs_refcount_modify_extent_error(cur->bc_mp,
1754 cur->bc_ag.pag->pag_agno, error, _RET_IP_);
1755 return error;
1756}
1757
1758/*
1759 * Add or remove refcount btree entries for CoW reservations.
1760 */
1761STATIC int
1762xfs_refcount_adjust_cow(
1763 struct xfs_btree_cur *cur,
1764 xfs_agblock_t agbno,
1765 xfs_extlen_t aglen,
1766 enum xfs_refc_adjust_op adj)
1767{
1768 bool shape_changed;
1769 int error;
1770
1771 /*
1772 * Ensure that no rcextents cross the boundary of the adjustment range.
1773 */
1774 error = xfs_refcount_split_extent(cur, XFS_REFC_DOMAIN_COW,
1775 agbno, &shape_changed);
1776 if (error)
1777 goto out_error;
1778
1779 error = xfs_refcount_split_extent(cur, XFS_REFC_DOMAIN_COW,
1780 agbno + aglen, &shape_changed);
1781 if (error)
1782 goto out_error;
1783
1784 /*
1785 * Try to merge with the left or right extents of the range.
1786 */
1787 error = xfs_refcount_merge_extents(cur, XFS_REFC_DOMAIN_COW, &agbno,
1788 &aglen, adj, &shape_changed);
1789 if (error)
1790 goto out_error;
1791
1792 /* Now that we've taken care of the ends, adjust the middle extents */
1793 error = xfs_refcount_adjust_cow_extents(cur, agbno, aglen, adj);
1794 if (error)
1795 goto out_error;
1796
1797 return 0;
1798
1799out_error:
1800 trace_xfs_refcount_adjust_cow_error(cur->bc_mp, cur->bc_ag.pag->pag_agno,
1801 error, _RET_IP_);
1802 return error;
1803}
1804
1805/*
1806 * Record a CoW allocation in the refcount btree.
1807 */
1808STATIC int
1809__xfs_refcount_cow_alloc(
1810 struct xfs_btree_cur *rcur,
1811 xfs_agblock_t agbno,
1812 xfs_extlen_t aglen)
1813{
1814 trace_xfs_refcount_cow_increase(rcur->bc_mp, rcur->bc_ag.pag->pag_agno,
1815 agbno, aglen);
1816
1817 /* Add refcount btree reservation */
1818 return xfs_refcount_adjust_cow(rcur, agbno, aglen,
1819 XFS_REFCOUNT_ADJUST_COW_ALLOC);
1820}
1821
1822/*
1823 * Remove a CoW allocation from the refcount btree.
1824 */
1825STATIC int
1826__xfs_refcount_cow_free(
1827 struct xfs_btree_cur *rcur,
1828 xfs_agblock_t agbno,
1829 xfs_extlen_t aglen)
1830{
1831 trace_xfs_refcount_cow_decrease(rcur->bc_mp, rcur->bc_ag.pag->pag_agno,
1832 agbno, aglen);
1833
1834 /* Remove refcount btree reservation */
1835 return xfs_refcount_adjust_cow(rcur, agbno, aglen,
1836 XFS_REFCOUNT_ADJUST_COW_FREE);
1837}
1838
1839/* Record a CoW staging extent in the refcount btree. */
1840void
1841xfs_refcount_alloc_cow_extent(
1842 struct xfs_trans *tp,
1843 xfs_fsblock_t fsb,
1844 xfs_extlen_t len)
1845{
1846 struct xfs_mount *mp = tp->t_mountp;
1847
1848 if (!xfs_has_reflink(mp))
1849 return;
1850
1851 __xfs_refcount_add(tp, XFS_REFCOUNT_ALLOC_COW, fsb, len);
1852
1853 /* Add rmap entry */
1854 xfs_rmap_alloc_extent(tp, XFS_FSB_TO_AGNO(mp, fsb),
1855 XFS_FSB_TO_AGBNO(mp, fsb), len, XFS_RMAP_OWN_COW);
1856}
1857
1858/* Forget a CoW staging event in the refcount btree. */
1859void
1860xfs_refcount_free_cow_extent(
1861 struct xfs_trans *tp,
1862 xfs_fsblock_t fsb,
1863 xfs_extlen_t len)
1864{
1865 struct xfs_mount *mp = tp->t_mountp;
1866
1867 if (!xfs_has_reflink(mp))
1868 return;
1869
1870 /* Remove rmap entry */
1871 xfs_rmap_free_extent(tp, XFS_FSB_TO_AGNO(mp, fsb),
1872 XFS_FSB_TO_AGBNO(mp, fsb), len, XFS_RMAP_OWN_COW);
1873 __xfs_refcount_add(tp, XFS_REFCOUNT_FREE_COW, fsb, len);
1874}
1875
1876struct xfs_refcount_recovery {
1877 struct list_head rr_list;
1878 struct xfs_refcount_irec rr_rrec;
1879};
1880
1881/* Stuff an extent on the recovery list. */
1882STATIC int
1883xfs_refcount_recover_extent(
1884 struct xfs_btree_cur *cur,
1885 const union xfs_btree_rec *rec,
1886 void *priv)
1887{
1888 struct list_head *debris = priv;
1889 struct xfs_refcount_recovery *rr;
1890
1891 if (XFS_IS_CORRUPT(cur->bc_mp,
1892 be32_to_cpu(rec->refc.rc_refcount) != 1))
1893 return -EFSCORRUPTED;
1894
1895 rr = kmalloc(sizeof(struct xfs_refcount_recovery),
1896 GFP_KERNEL | __GFP_NOFAIL);
1897 INIT_LIST_HEAD(&rr->rr_list);
1898 xfs_refcount_btrec_to_irec(rec, &rr->rr_rrec);
1899
1900 if (xfs_refcount_check_irec(cur->bc_ag.pag, &rr->rr_rrec) != NULL ||
1901 XFS_IS_CORRUPT(cur->bc_mp,
1902 rr->rr_rrec.rc_domain != XFS_REFC_DOMAIN_COW)) {
1903 kfree(rr);
1904 return -EFSCORRUPTED;
1905 }
1906
1907 list_add_tail(&rr->rr_list, debris);
1908 return 0;
1909}
1910
1911/* Find and remove leftover CoW reservations. */
1912int
1913xfs_refcount_recover_cow_leftovers(
1914 struct xfs_mount *mp,
1915 struct xfs_perag *pag)
1916{
1917 struct xfs_trans *tp;
1918 struct xfs_btree_cur *cur;
1919 struct xfs_buf *agbp;
1920 struct xfs_refcount_recovery *rr, *n;
1921 struct list_head debris;
1922 union xfs_btree_irec low = {
1923 .rc.rc_domain = XFS_REFC_DOMAIN_COW,
1924 };
1925 union xfs_btree_irec high = {
1926 .rc.rc_domain = XFS_REFC_DOMAIN_COW,
1927 .rc.rc_startblock = -1U,
1928 };
1929 xfs_fsblock_t fsb;
1930 int error;
1931
1932 /* reflink filesystems mustn't have AGs larger than 2^31-1 blocks */
1933 BUILD_BUG_ON(XFS_MAX_CRC_AG_BLOCKS >= XFS_REFC_COWFLAG);
1934 if (mp->m_sb.sb_agblocks > XFS_MAX_CRC_AG_BLOCKS)
1935 return -EOPNOTSUPP;
1936
1937 INIT_LIST_HEAD(&debris);
1938
1939 /*
1940 * In this first part, we use an empty transaction to gather up
1941 * all the leftover CoW extents so that we can subsequently
1942 * delete them. The empty transaction is used to avoid
1943 * a buffer lock deadlock if there happens to be a loop in the
1944 * refcountbt because we're allowed to re-grab a buffer that is
1945 * already attached to our transaction. When we're done
1946 * recording the CoW debris we cancel the (empty) transaction
1947 * and everything goes away cleanly.
1948 */
1949 error = xfs_trans_alloc_empty(mp, &tp);
1950 if (error)
1951 return error;
1952
1953 error = xfs_alloc_read_agf(pag, tp, 0, &agbp);
1954 if (error)
1955 goto out_trans;
1956 cur = xfs_refcountbt_init_cursor(mp, tp, agbp, pag);
1957
1958 /* Find all the leftover CoW staging extents. */
1959 error = xfs_btree_query_range(cur, &low, &high,
1960 xfs_refcount_recover_extent, &debris);
1961 xfs_btree_del_cursor(cur, error);
1962 xfs_trans_brelse(tp, agbp);
1963 xfs_trans_cancel(tp);
1964 if (error)
1965 goto out_free;
1966
1967 /* Now iterate the list to free the leftovers */
1968 list_for_each_entry_safe(rr, n, &debris, rr_list) {
1969 /* Set up transaction. */
1970 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, 0, 0, 0, &tp);
1971 if (error)
1972 goto out_free;
1973
1974 trace_xfs_refcount_recover_extent(mp, pag->pag_agno,
1975 &rr->rr_rrec);
1976
1977 /* Free the orphan record */
1978 fsb = XFS_AGB_TO_FSB(mp, pag->pag_agno,
1979 rr->rr_rrec.rc_startblock);
1980 xfs_refcount_free_cow_extent(tp, fsb,
1981 rr->rr_rrec.rc_blockcount);
1982
1983 /* Free the block. */
1984 error = xfs_free_extent_later(tp, fsb,
1985 rr->rr_rrec.rc_blockcount, NULL,
1986 XFS_AG_RESV_NONE, false);
1987 if (error)
1988 goto out_trans;
1989
1990 error = xfs_trans_commit(tp);
1991 if (error)
1992 goto out_free;
1993
1994 list_del(&rr->rr_list);
1995 kfree(rr);
1996 }
1997
1998 return error;
1999out_trans:
2000 xfs_trans_cancel(tp);
2001out_free:
2002 /* Free the leftover list */
2003 list_for_each_entry_safe(rr, n, &debris, rr_list) {
2004 list_del(&rr->rr_list);
2005 kfree(rr);
2006 }
2007 return error;
2008}
2009
2010/*
2011 * Scan part of the keyspace of the refcount records and tell us if the area
2012 * has no records, is fully mapped by records, or is partially filled.
2013 */
2014int
2015xfs_refcount_has_records(
2016 struct xfs_btree_cur *cur,
2017 enum xfs_refc_domain domain,
2018 xfs_agblock_t bno,
2019 xfs_extlen_t len,
2020 enum xbtree_recpacking *outcome)
2021{
2022 union xfs_btree_irec low;
2023 union xfs_btree_irec high;
2024
2025 memset(&low, 0, sizeof(low));
2026 low.rc.rc_startblock = bno;
2027 memset(&high, 0xFF, sizeof(high));
2028 high.rc.rc_startblock = bno + len - 1;
2029 low.rc.rc_domain = high.rc.rc_domain = domain;
2030
2031 return xfs_btree_has_records(cur, &low, &high, NULL, outcome);
2032}
2033
2034struct xfs_refcount_query_range_info {
2035 xfs_refcount_query_range_fn fn;
2036 void *priv;
2037};
2038
2039/* Format btree record and pass to our callback. */
2040STATIC int
2041xfs_refcount_query_range_helper(
2042 struct xfs_btree_cur *cur,
2043 const union xfs_btree_rec *rec,
2044 void *priv)
2045{
2046 struct xfs_refcount_query_range_info *query = priv;
2047 struct xfs_refcount_irec irec;
2048 xfs_failaddr_t fa;
2049
2050 xfs_refcount_btrec_to_irec(rec, &irec);
2051 fa = xfs_refcount_check_irec(cur->bc_ag.pag, &irec);
2052 if (fa)
2053 return xfs_refcount_complain_bad_rec(cur, fa, &irec);
2054
2055 return query->fn(cur, &irec, query->priv);
2056}
2057
2058/* Find all refcount records between two keys. */
2059int
2060xfs_refcount_query_range(
2061 struct xfs_btree_cur *cur,
2062 const struct xfs_refcount_irec *low_rec,
2063 const struct xfs_refcount_irec *high_rec,
2064 xfs_refcount_query_range_fn fn,
2065 void *priv)
2066{
2067 union xfs_btree_irec low_brec = { .rc = *low_rec };
2068 union xfs_btree_irec high_brec = { .rc = *high_rec };
2069 struct xfs_refcount_query_range_info query = { .priv = priv, .fn = fn };
2070
2071 return xfs_btree_query_range(cur, &low_brec, &high_brec,
2072 xfs_refcount_query_range_helper, &query);
2073}
2074
2075int __init
2076xfs_refcount_intent_init_cache(void)
2077{
2078 xfs_refcount_intent_cache = kmem_cache_create("xfs_refc_intent",
2079 sizeof(struct xfs_refcount_intent),
2080 0, 0, NULL);
2081
2082 return xfs_refcount_intent_cache != NULL ? 0 : -ENOMEM;
2083}
2084
2085void
2086xfs_refcount_intent_destroy_cache(void)
2087{
2088 kmem_cache_destroy(xfs_refcount_intent_cache);
2089 xfs_refcount_intent_cache = NULL;
2090}