xref: /openbmc/linux/fs/xfs/libxfs/xfs_alloc_btree.c (revision c29b9772)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2000-2001,2005 Silicon Graphics, 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_mount.h"
13 #include "xfs_btree.h"
14 #include "xfs_btree_staging.h"
15 #include "xfs_alloc_btree.h"
16 #include "xfs_alloc.h"
17 #include "xfs_extent_busy.h"
18 #include "xfs_error.h"
19 #include "xfs_trace.h"
20 #include "xfs_trans.h"
21 #include "xfs_ag.h"
22 
23 static struct kmem_cache	*xfs_allocbt_cur_cache;
24 
25 STATIC struct xfs_btree_cur *
26 xfs_allocbt_dup_cursor(
27 	struct xfs_btree_cur	*cur)
28 {
29 	return xfs_allocbt_init_cursor(cur->bc_mp, cur->bc_tp,
30 			cur->bc_ag.agbp, cur->bc_ag.pag, cur->bc_btnum);
31 }
32 
33 STATIC void
34 xfs_allocbt_set_root(
35 	struct xfs_btree_cur		*cur,
36 	const union xfs_btree_ptr	*ptr,
37 	int				inc)
38 {
39 	struct xfs_buf		*agbp = cur->bc_ag.agbp;
40 	struct xfs_agf		*agf = agbp->b_addr;
41 	int			btnum = cur->bc_btnum;
42 
43 	ASSERT(ptr->s != 0);
44 
45 	agf->agf_roots[btnum] = ptr->s;
46 	be32_add_cpu(&agf->agf_levels[btnum], inc);
47 	cur->bc_ag.pag->pagf_levels[btnum] += inc;
48 
49 	xfs_alloc_log_agf(cur->bc_tp, agbp, XFS_AGF_ROOTS | XFS_AGF_LEVELS);
50 }
51 
52 STATIC int
53 xfs_allocbt_alloc_block(
54 	struct xfs_btree_cur		*cur,
55 	const union xfs_btree_ptr	*start,
56 	union xfs_btree_ptr		*new,
57 	int				*stat)
58 {
59 	int			error;
60 	xfs_agblock_t		bno;
61 
62 	/* Allocate the new block from the freelist. If we can't, give up.  */
63 	error = xfs_alloc_get_freelist(cur->bc_ag.pag, cur->bc_tp,
64 			cur->bc_ag.agbp, &bno, 1);
65 	if (error)
66 		return error;
67 
68 	if (bno == NULLAGBLOCK) {
69 		*stat = 0;
70 		return 0;
71 	}
72 
73 	atomic64_inc(&cur->bc_mp->m_allocbt_blks);
74 	xfs_extent_busy_reuse(cur->bc_mp, cur->bc_ag.pag, bno, 1, false);
75 
76 	new->s = cpu_to_be32(bno);
77 
78 	*stat = 1;
79 	return 0;
80 }
81 
82 STATIC int
83 xfs_allocbt_free_block(
84 	struct xfs_btree_cur	*cur,
85 	struct xfs_buf		*bp)
86 {
87 	struct xfs_buf		*agbp = cur->bc_ag.agbp;
88 	xfs_agblock_t		bno;
89 	int			error;
90 
91 	bno = xfs_daddr_to_agbno(cur->bc_mp, xfs_buf_daddr(bp));
92 	error = xfs_alloc_put_freelist(cur->bc_ag.pag, cur->bc_tp, agbp, NULL,
93 			bno, 1);
94 	if (error)
95 		return error;
96 
97 	atomic64_dec(&cur->bc_mp->m_allocbt_blks);
98 	xfs_extent_busy_insert(cur->bc_tp, agbp->b_pag, bno, 1,
99 			      XFS_EXTENT_BUSY_SKIP_DISCARD);
100 	return 0;
101 }
102 
103 /*
104  * Update the longest extent in the AGF
105  */
106 STATIC void
107 xfs_allocbt_update_lastrec(
108 	struct xfs_btree_cur		*cur,
109 	const struct xfs_btree_block	*block,
110 	const union xfs_btree_rec	*rec,
111 	int				ptr,
112 	int				reason)
113 {
114 	struct xfs_agf		*agf = cur->bc_ag.agbp->b_addr;
115 	struct xfs_perag	*pag;
116 	__be32			len;
117 	int			numrecs;
118 
119 	ASSERT(cur->bc_btnum == XFS_BTNUM_CNT);
120 
121 	switch (reason) {
122 	case LASTREC_UPDATE:
123 		/*
124 		 * If this is the last leaf block and it's the last record,
125 		 * then update the size of the longest extent in the AG.
126 		 */
127 		if (ptr != xfs_btree_get_numrecs(block))
128 			return;
129 		len = rec->alloc.ar_blockcount;
130 		break;
131 	case LASTREC_INSREC:
132 		if (be32_to_cpu(rec->alloc.ar_blockcount) <=
133 		    be32_to_cpu(agf->agf_longest))
134 			return;
135 		len = rec->alloc.ar_blockcount;
136 		break;
137 	case LASTREC_DELREC:
138 		numrecs = xfs_btree_get_numrecs(block);
139 		if (ptr <= numrecs)
140 			return;
141 		ASSERT(ptr == numrecs + 1);
142 
143 		if (numrecs) {
144 			xfs_alloc_rec_t *rrp;
145 
146 			rrp = XFS_ALLOC_REC_ADDR(cur->bc_mp, block, numrecs);
147 			len = rrp->ar_blockcount;
148 		} else {
149 			len = 0;
150 		}
151 
152 		break;
153 	default:
154 		ASSERT(0);
155 		return;
156 	}
157 
158 	agf->agf_longest = len;
159 	pag = cur->bc_ag.agbp->b_pag;
160 	pag->pagf_longest = be32_to_cpu(len);
161 	xfs_alloc_log_agf(cur->bc_tp, cur->bc_ag.agbp, XFS_AGF_LONGEST);
162 }
163 
164 STATIC int
165 xfs_allocbt_get_minrecs(
166 	struct xfs_btree_cur	*cur,
167 	int			level)
168 {
169 	return cur->bc_mp->m_alloc_mnr[level != 0];
170 }
171 
172 STATIC int
173 xfs_allocbt_get_maxrecs(
174 	struct xfs_btree_cur	*cur,
175 	int			level)
176 {
177 	return cur->bc_mp->m_alloc_mxr[level != 0];
178 }
179 
180 STATIC void
181 xfs_allocbt_init_key_from_rec(
182 	union xfs_btree_key		*key,
183 	const union xfs_btree_rec	*rec)
184 {
185 	key->alloc.ar_startblock = rec->alloc.ar_startblock;
186 	key->alloc.ar_blockcount = rec->alloc.ar_blockcount;
187 }
188 
189 STATIC void
190 xfs_bnobt_init_high_key_from_rec(
191 	union xfs_btree_key		*key,
192 	const union xfs_btree_rec	*rec)
193 {
194 	__u32				x;
195 
196 	x = be32_to_cpu(rec->alloc.ar_startblock);
197 	x += be32_to_cpu(rec->alloc.ar_blockcount) - 1;
198 	key->alloc.ar_startblock = cpu_to_be32(x);
199 	key->alloc.ar_blockcount = 0;
200 }
201 
202 STATIC void
203 xfs_cntbt_init_high_key_from_rec(
204 	union xfs_btree_key		*key,
205 	const union xfs_btree_rec	*rec)
206 {
207 	key->alloc.ar_blockcount = rec->alloc.ar_blockcount;
208 	key->alloc.ar_startblock = 0;
209 }
210 
211 STATIC void
212 xfs_allocbt_init_rec_from_cur(
213 	struct xfs_btree_cur	*cur,
214 	union xfs_btree_rec	*rec)
215 {
216 	rec->alloc.ar_startblock = cpu_to_be32(cur->bc_rec.a.ar_startblock);
217 	rec->alloc.ar_blockcount = cpu_to_be32(cur->bc_rec.a.ar_blockcount);
218 }
219 
220 STATIC void
221 xfs_allocbt_init_ptr_from_cur(
222 	struct xfs_btree_cur	*cur,
223 	union xfs_btree_ptr	*ptr)
224 {
225 	struct xfs_agf		*agf = cur->bc_ag.agbp->b_addr;
226 
227 	ASSERT(cur->bc_ag.pag->pag_agno == be32_to_cpu(agf->agf_seqno));
228 
229 	ptr->s = agf->agf_roots[cur->bc_btnum];
230 }
231 
232 STATIC int64_t
233 xfs_bnobt_key_diff(
234 	struct xfs_btree_cur		*cur,
235 	const union xfs_btree_key	*key)
236 {
237 	struct xfs_alloc_rec_incore	*rec = &cur->bc_rec.a;
238 	const struct xfs_alloc_rec	*kp = &key->alloc;
239 
240 	return (int64_t)be32_to_cpu(kp->ar_startblock) - rec->ar_startblock;
241 }
242 
243 STATIC int64_t
244 xfs_cntbt_key_diff(
245 	struct xfs_btree_cur		*cur,
246 	const union xfs_btree_key	*key)
247 {
248 	struct xfs_alloc_rec_incore	*rec = &cur->bc_rec.a;
249 	const struct xfs_alloc_rec	*kp = &key->alloc;
250 	int64_t				diff;
251 
252 	diff = (int64_t)be32_to_cpu(kp->ar_blockcount) - rec->ar_blockcount;
253 	if (diff)
254 		return diff;
255 
256 	return (int64_t)be32_to_cpu(kp->ar_startblock) - rec->ar_startblock;
257 }
258 
259 STATIC int64_t
260 xfs_bnobt_diff_two_keys(
261 	struct xfs_btree_cur		*cur,
262 	const union xfs_btree_key	*k1,
263 	const union xfs_btree_key	*k2)
264 {
265 	return (int64_t)be32_to_cpu(k1->alloc.ar_startblock) -
266 			  be32_to_cpu(k2->alloc.ar_startblock);
267 }
268 
269 STATIC int64_t
270 xfs_cntbt_diff_two_keys(
271 	struct xfs_btree_cur		*cur,
272 	const union xfs_btree_key	*k1,
273 	const union xfs_btree_key	*k2)
274 {
275 	int64_t				diff;
276 
277 	diff =  be32_to_cpu(k1->alloc.ar_blockcount) -
278 		be32_to_cpu(k2->alloc.ar_blockcount);
279 	if (diff)
280 		return diff;
281 
282 	return  be32_to_cpu(k1->alloc.ar_startblock) -
283 		be32_to_cpu(k2->alloc.ar_startblock);
284 }
285 
286 static xfs_failaddr_t
287 xfs_allocbt_verify(
288 	struct xfs_buf		*bp)
289 {
290 	struct xfs_mount	*mp = bp->b_mount;
291 	struct xfs_btree_block	*block = XFS_BUF_TO_BLOCK(bp);
292 	struct xfs_perag	*pag = bp->b_pag;
293 	xfs_failaddr_t		fa;
294 	unsigned int		level;
295 	xfs_btnum_t		btnum = XFS_BTNUM_BNOi;
296 
297 	if (!xfs_verify_magic(bp, block->bb_magic))
298 		return __this_address;
299 
300 	if (xfs_has_crc(mp)) {
301 		fa = xfs_btree_sblock_v5hdr_verify(bp);
302 		if (fa)
303 			return fa;
304 	}
305 
306 	/*
307 	 * The perag may not be attached during grow operations or fully
308 	 * initialized from the AGF during log recovery. Therefore we can only
309 	 * check against maximum tree depth from those contexts.
310 	 *
311 	 * Otherwise check against the per-tree limit. Peek at one of the
312 	 * verifier magic values to determine the type of tree we're verifying
313 	 * against.
314 	 */
315 	level = be16_to_cpu(block->bb_level);
316 	if (bp->b_ops->magic[0] == cpu_to_be32(XFS_ABTC_MAGIC))
317 		btnum = XFS_BTNUM_CNTi;
318 	if (pag && xfs_perag_initialised_agf(pag)) {
319 		if (level >= pag->pagf_levels[btnum])
320 			return __this_address;
321 	} else if (level >= mp->m_alloc_maxlevels)
322 		return __this_address;
323 
324 	return xfs_btree_sblock_verify(bp, mp->m_alloc_mxr[level != 0]);
325 }
326 
327 static void
328 xfs_allocbt_read_verify(
329 	struct xfs_buf	*bp)
330 {
331 	xfs_failaddr_t	fa;
332 
333 	if (!xfs_btree_sblock_verify_crc(bp))
334 		xfs_verifier_error(bp, -EFSBADCRC, __this_address);
335 	else {
336 		fa = xfs_allocbt_verify(bp);
337 		if (fa)
338 			xfs_verifier_error(bp, -EFSCORRUPTED, fa);
339 	}
340 
341 	if (bp->b_error)
342 		trace_xfs_btree_corrupt(bp, _RET_IP_);
343 }
344 
345 static void
346 xfs_allocbt_write_verify(
347 	struct xfs_buf	*bp)
348 {
349 	xfs_failaddr_t	fa;
350 
351 	fa = xfs_allocbt_verify(bp);
352 	if (fa) {
353 		trace_xfs_btree_corrupt(bp, _RET_IP_);
354 		xfs_verifier_error(bp, -EFSCORRUPTED, fa);
355 		return;
356 	}
357 	xfs_btree_sblock_calc_crc(bp);
358 
359 }
360 
361 const struct xfs_buf_ops xfs_bnobt_buf_ops = {
362 	.name = "xfs_bnobt",
363 	.magic = { cpu_to_be32(XFS_ABTB_MAGIC),
364 		   cpu_to_be32(XFS_ABTB_CRC_MAGIC) },
365 	.verify_read = xfs_allocbt_read_verify,
366 	.verify_write = xfs_allocbt_write_verify,
367 	.verify_struct = xfs_allocbt_verify,
368 };
369 
370 const struct xfs_buf_ops xfs_cntbt_buf_ops = {
371 	.name = "xfs_cntbt",
372 	.magic = { cpu_to_be32(XFS_ABTC_MAGIC),
373 		   cpu_to_be32(XFS_ABTC_CRC_MAGIC) },
374 	.verify_read = xfs_allocbt_read_verify,
375 	.verify_write = xfs_allocbt_write_verify,
376 	.verify_struct = xfs_allocbt_verify,
377 };
378 
379 STATIC int
380 xfs_bnobt_keys_inorder(
381 	struct xfs_btree_cur		*cur,
382 	const union xfs_btree_key	*k1,
383 	const union xfs_btree_key	*k2)
384 {
385 	return be32_to_cpu(k1->alloc.ar_startblock) <
386 	       be32_to_cpu(k2->alloc.ar_startblock);
387 }
388 
389 STATIC int
390 xfs_bnobt_recs_inorder(
391 	struct xfs_btree_cur		*cur,
392 	const union xfs_btree_rec	*r1,
393 	const union xfs_btree_rec	*r2)
394 {
395 	return be32_to_cpu(r1->alloc.ar_startblock) +
396 		be32_to_cpu(r1->alloc.ar_blockcount) <=
397 		be32_to_cpu(r2->alloc.ar_startblock);
398 }
399 
400 STATIC int
401 xfs_cntbt_keys_inorder(
402 	struct xfs_btree_cur		*cur,
403 	const union xfs_btree_key	*k1,
404 	const union xfs_btree_key	*k2)
405 {
406 	return be32_to_cpu(k1->alloc.ar_blockcount) <
407 		be32_to_cpu(k2->alloc.ar_blockcount) ||
408 		(k1->alloc.ar_blockcount == k2->alloc.ar_blockcount &&
409 		 be32_to_cpu(k1->alloc.ar_startblock) <
410 		 be32_to_cpu(k2->alloc.ar_startblock));
411 }
412 
413 STATIC int
414 xfs_cntbt_recs_inorder(
415 	struct xfs_btree_cur		*cur,
416 	const union xfs_btree_rec	*r1,
417 	const union xfs_btree_rec	*r2)
418 {
419 	return be32_to_cpu(r1->alloc.ar_blockcount) <
420 		be32_to_cpu(r2->alloc.ar_blockcount) ||
421 		(r1->alloc.ar_blockcount == r2->alloc.ar_blockcount &&
422 		 be32_to_cpu(r1->alloc.ar_startblock) <
423 		 be32_to_cpu(r2->alloc.ar_startblock));
424 }
425 
426 static const struct xfs_btree_ops xfs_bnobt_ops = {
427 	.rec_len		= sizeof(xfs_alloc_rec_t),
428 	.key_len		= sizeof(xfs_alloc_key_t),
429 
430 	.dup_cursor		= xfs_allocbt_dup_cursor,
431 	.set_root		= xfs_allocbt_set_root,
432 	.alloc_block		= xfs_allocbt_alloc_block,
433 	.free_block		= xfs_allocbt_free_block,
434 	.update_lastrec		= xfs_allocbt_update_lastrec,
435 	.get_minrecs		= xfs_allocbt_get_minrecs,
436 	.get_maxrecs		= xfs_allocbt_get_maxrecs,
437 	.init_key_from_rec	= xfs_allocbt_init_key_from_rec,
438 	.init_high_key_from_rec	= xfs_bnobt_init_high_key_from_rec,
439 	.init_rec_from_cur	= xfs_allocbt_init_rec_from_cur,
440 	.init_ptr_from_cur	= xfs_allocbt_init_ptr_from_cur,
441 	.key_diff		= xfs_bnobt_key_diff,
442 	.buf_ops		= &xfs_bnobt_buf_ops,
443 	.diff_two_keys		= xfs_bnobt_diff_two_keys,
444 	.keys_inorder		= xfs_bnobt_keys_inorder,
445 	.recs_inorder		= xfs_bnobt_recs_inorder,
446 };
447 
448 static const struct xfs_btree_ops xfs_cntbt_ops = {
449 	.rec_len		= sizeof(xfs_alloc_rec_t),
450 	.key_len		= sizeof(xfs_alloc_key_t),
451 
452 	.dup_cursor		= xfs_allocbt_dup_cursor,
453 	.set_root		= xfs_allocbt_set_root,
454 	.alloc_block		= xfs_allocbt_alloc_block,
455 	.free_block		= xfs_allocbt_free_block,
456 	.update_lastrec		= xfs_allocbt_update_lastrec,
457 	.get_minrecs		= xfs_allocbt_get_minrecs,
458 	.get_maxrecs		= xfs_allocbt_get_maxrecs,
459 	.init_key_from_rec	= xfs_allocbt_init_key_from_rec,
460 	.init_high_key_from_rec	= xfs_cntbt_init_high_key_from_rec,
461 	.init_rec_from_cur	= xfs_allocbt_init_rec_from_cur,
462 	.init_ptr_from_cur	= xfs_allocbt_init_ptr_from_cur,
463 	.key_diff		= xfs_cntbt_key_diff,
464 	.buf_ops		= &xfs_cntbt_buf_ops,
465 	.diff_two_keys		= xfs_cntbt_diff_two_keys,
466 	.keys_inorder		= xfs_cntbt_keys_inorder,
467 	.recs_inorder		= xfs_cntbt_recs_inorder,
468 };
469 
470 /* Allocate most of a new allocation btree cursor. */
471 STATIC struct xfs_btree_cur *
472 xfs_allocbt_init_common(
473 	struct xfs_mount	*mp,
474 	struct xfs_trans	*tp,
475 	struct xfs_perag	*pag,
476 	xfs_btnum_t		btnum)
477 {
478 	struct xfs_btree_cur	*cur;
479 
480 	ASSERT(btnum == XFS_BTNUM_BNO || btnum == XFS_BTNUM_CNT);
481 
482 	cur = xfs_btree_alloc_cursor(mp, tp, btnum, mp->m_alloc_maxlevels,
483 			xfs_allocbt_cur_cache);
484 	cur->bc_ag.abt.active = false;
485 
486 	if (btnum == XFS_BTNUM_CNT) {
487 		cur->bc_ops = &xfs_cntbt_ops;
488 		cur->bc_statoff = XFS_STATS_CALC_INDEX(xs_abtc_2);
489 		cur->bc_flags = XFS_BTREE_LASTREC_UPDATE;
490 	} else {
491 		cur->bc_ops = &xfs_bnobt_ops;
492 		cur->bc_statoff = XFS_STATS_CALC_INDEX(xs_abtb_2);
493 	}
494 
495 	/* take a reference for the cursor */
496 	atomic_inc(&pag->pag_ref);
497 	cur->bc_ag.pag = pag;
498 
499 	if (xfs_has_crc(mp))
500 		cur->bc_flags |= XFS_BTREE_CRC_BLOCKS;
501 
502 	return cur;
503 }
504 
505 /*
506  * Allocate a new allocation btree cursor.
507  */
508 struct xfs_btree_cur *			/* new alloc btree cursor */
509 xfs_allocbt_init_cursor(
510 	struct xfs_mount	*mp,		/* file system mount point */
511 	struct xfs_trans	*tp,		/* transaction pointer */
512 	struct xfs_buf		*agbp,		/* buffer for agf structure */
513 	struct xfs_perag	*pag,
514 	xfs_btnum_t		btnum)		/* btree identifier */
515 {
516 	struct xfs_agf		*agf = agbp->b_addr;
517 	struct xfs_btree_cur	*cur;
518 
519 	cur = xfs_allocbt_init_common(mp, tp, pag, btnum);
520 	if (btnum == XFS_BTNUM_CNT)
521 		cur->bc_nlevels = be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNT]);
522 	else
523 		cur->bc_nlevels = be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNO]);
524 
525 	cur->bc_ag.agbp = agbp;
526 
527 	return cur;
528 }
529 
530 /* Create a free space btree cursor with a fake root for staging. */
531 struct xfs_btree_cur *
532 xfs_allocbt_stage_cursor(
533 	struct xfs_mount	*mp,
534 	struct xbtree_afakeroot	*afake,
535 	struct xfs_perag	*pag,
536 	xfs_btnum_t		btnum)
537 {
538 	struct xfs_btree_cur	*cur;
539 
540 	cur = xfs_allocbt_init_common(mp, NULL, pag, btnum);
541 	xfs_btree_stage_afakeroot(cur, afake);
542 	return cur;
543 }
544 
545 /*
546  * Install a new free space btree root.  Caller is responsible for invalidating
547  * and freeing the old btree blocks.
548  */
549 void
550 xfs_allocbt_commit_staged_btree(
551 	struct xfs_btree_cur	*cur,
552 	struct xfs_trans	*tp,
553 	struct xfs_buf		*agbp)
554 {
555 	struct xfs_agf		*agf = agbp->b_addr;
556 	struct xbtree_afakeroot	*afake = cur->bc_ag.afake;
557 
558 	ASSERT(cur->bc_flags & XFS_BTREE_STAGING);
559 
560 	agf->agf_roots[cur->bc_btnum] = cpu_to_be32(afake->af_root);
561 	agf->agf_levels[cur->bc_btnum] = cpu_to_be32(afake->af_levels);
562 	xfs_alloc_log_agf(tp, agbp, XFS_AGF_ROOTS | XFS_AGF_LEVELS);
563 
564 	if (cur->bc_btnum == XFS_BTNUM_BNO) {
565 		xfs_btree_commit_afakeroot(cur, tp, agbp, &xfs_bnobt_ops);
566 	} else {
567 		cur->bc_flags |= XFS_BTREE_LASTREC_UPDATE;
568 		xfs_btree_commit_afakeroot(cur, tp, agbp, &xfs_cntbt_ops);
569 	}
570 }
571 
572 /* Calculate number of records in an alloc btree block. */
573 static inline unsigned int
574 xfs_allocbt_block_maxrecs(
575 	unsigned int		blocklen,
576 	bool			leaf)
577 {
578 	if (leaf)
579 		return blocklen / sizeof(xfs_alloc_rec_t);
580 	return blocklen / (sizeof(xfs_alloc_key_t) + sizeof(xfs_alloc_ptr_t));
581 }
582 
583 /*
584  * Calculate number of records in an alloc btree block.
585  */
586 int
587 xfs_allocbt_maxrecs(
588 	struct xfs_mount	*mp,
589 	int			blocklen,
590 	int			leaf)
591 {
592 	blocklen -= XFS_ALLOC_BLOCK_LEN(mp);
593 	return xfs_allocbt_block_maxrecs(blocklen, leaf);
594 }
595 
596 /* Free space btrees are at their largest when every other block is free. */
597 #define XFS_MAX_FREESP_RECORDS	((XFS_MAX_AG_BLOCKS + 1) / 2)
598 
599 /* Compute the max possible height for free space btrees. */
600 unsigned int
601 xfs_allocbt_maxlevels_ondisk(void)
602 {
603 	unsigned int		minrecs[2];
604 	unsigned int		blocklen;
605 
606 	blocklen = min(XFS_MIN_BLOCKSIZE - XFS_BTREE_SBLOCK_LEN,
607 		       XFS_MIN_CRC_BLOCKSIZE - XFS_BTREE_SBLOCK_CRC_LEN);
608 
609 	minrecs[0] = xfs_allocbt_block_maxrecs(blocklen, true) / 2;
610 	minrecs[1] = xfs_allocbt_block_maxrecs(blocklen, false) / 2;
611 
612 	return xfs_btree_compute_maxlevels(minrecs, XFS_MAX_FREESP_RECORDS);
613 }
614 
615 /* Calculate the freespace btree size for some records. */
616 xfs_extlen_t
617 xfs_allocbt_calc_size(
618 	struct xfs_mount	*mp,
619 	unsigned long long	len)
620 {
621 	return xfs_btree_calc_size(mp->m_alloc_mnr, len);
622 }
623 
624 int __init
625 xfs_allocbt_init_cur_cache(void)
626 {
627 	xfs_allocbt_cur_cache = kmem_cache_create("xfs_bnobt_cur",
628 			xfs_btree_cur_sizeof(xfs_allocbt_maxlevels_ondisk()),
629 			0, 0, NULL);
630 
631 	if (!xfs_allocbt_cur_cache)
632 		return -ENOMEM;
633 	return 0;
634 }
635 
636 void
637 xfs_allocbt_destroy_cur_cache(void)
638 {
639 	kmem_cache_destroy(xfs_allocbt_cur_cache);
640 	xfs_allocbt_cur_cache = NULL;
641 }
642