xref: /linux/fs/xfs/libxfs/xfs_alloc_btree.c (revision 9acb51e9617c28a92f9ce2af767db6bd660a6d4f)
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_health.h"
20  #include "xfs_trace.h"
21  #include "xfs_trans.h"
22  #include "xfs_ag.h"
23  
24  static struct kmem_cache	*xfs_allocbt_cur_cache;
25  
26  STATIC struct xfs_btree_cur *
27  xfs_bnobt_dup_cursor(
28  	struct xfs_btree_cur	*cur)
29  {
30  	return xfs_bnobt_init_cursor(cur->bc_mp, cur->bc_tp, cur->bc_ag.agbp,
31  			cur->bc_ag.pag);
32  }
33  
34  STATIC struct xfs_btree_cur *
35  xfs_cntbt_dup_cursor(
36  	struct xfs_btree_cur	*cur)
37  {
38  	return xfs_cntbt_init_cursor(cur->bc_mp, cur->bc_tp, cur->bc_ag.agbp,
39  			cur->bc_ag.pag);
40  }
41  
42  
43  STATIC void
44  xfs_allocbt_set_root(
45  	struct xfs_btree_cur		*cur,
46  	const union xfs_btree_ptr	*ptr,
47  	int				inc)
48  {
49  	struct xfs_buf		*agbp = cur->bc_ag.agbp;
50  	struct xfs_agf		*agf = agbp->b_addr;
51  
52  	ASSERT(ptr->s != 0);
53  
54  	if (xfs_btree_is_bno(cur->bc_ops)) {
55  		agf->agf_bno_root = ptr->s;
56  		be32_add_cpu(&agf->agf_bno_level, inc);
57  		cur->bc_ag.pag->pagf_bno_level += inc;
58  	} else {
59  		agf->agf_cnt_root = ptr->s;
60  		be32_add_cpu(&agf->agf_cnt_level, inc);
61  		cur->bc_ag.pag->pagf_cnt_level += inc;
62  	}
63  
64  	xfs_alloc_log_agf(cur->bc_tp, agbp, XFS_AGF_ROOTS | XFS_AGF_LEVELS);
65  }
66  
67  STATIC int
68  xfs_allocbt_alloc_block(
69  	struct xfs_btree_cur		*cur,
70  	const union xfs_btree_ptr	*start,
71  	union xfs_btree_ptr		*new,
72  	int				*stat)
73  {
74  	int			error;
75  	xfs_agblock_t		bno;
76  
77  	/* Allocate the new block from the freelist. If we can't, give up.  */
78  	error = xfs_alloc_get_freelist(cur->bc_ag.pag, cur->bc_tp,
79  			cur->bc_ag.agbp, &bno, 1);
80  	if (error)
81  		return error;
82  
83  	if (bno == NULLAGBLOCK) {
84  		*stat = 0;
85  		return 0;
86  	}
87  
88  	atomic64_inc(&cur->bc_mp->m_allocbt_blks);
89  	xfs_extent_busy_reuse(cur->bc_mp, cur->bc_ag.pag, bno, 1, false);
90  
91  	new->s = cpu_to_be32(bno);
92  
93  	*stat = 1;
94  	return 0;
95  }
96  
97  STATIC int
98  xfs_allocbt_free_block(
99  	struct xfs_btree_cur	*cur,
100  	struct xfs_buf		*bp)
101  {
102  	struct xfs_buf		*agbp = cur->bc_ag.agbp;
103  	xfs_agblock_t		bno;
104  	int			error;
105  
106  	bno = xfs_daddr_to_agbno(cur->bc_mp, xfs_buf_daddr(bp));
107  	error = xfs_alloc_put_freelist(cur->bc_ag.pag, cur->bc_tp, agbp, NULL,
108  			bno, 1);
109  	if (error)
110  		return error;
111  
112  	atomic64_dec(&cur->bc_mp->m_allocbt_blks);
113  	xfs_extent_busy_insert(cur->bc_tp, agbp->b_pag, bno, 1,
114  			      XFS_EXTENT_BUSY_SKIP_DISCARD);
115  	return 0;
116  }
117  
118  STATIC int
119  xfs_allocbt_get_minrecs(
120  	struct xfs_btree_cur	*cur,
121  	int			level)
122  {
123  	return cur->bc_mp->m_alloc_mnr[level != 0];
124  }
125  
126  STATIC int
127  xfs_allocbt_get_maxrecs(
128  	struct xfs_btree_cur	*cur,
129  	int			level)
130  {
131  	return cur->bc_mp->m_alloc_mxr[level != 0];
132  }
133  
134  STATIC void
135  xfs_allocbt_init_key_from_rec(
136  	union xfs_btree_key		*key,
137  	const union xfs_btree_rec	*rec)
138  {
139  	key->alloc.ar_startblock = rec->alloc.ar_startblock;
140  	key->alloc.ar_blockcount = rec->alloc.ar_blockcount;
141  }
142  
143  STATIC void
144  xfs_bnobt_init_high_key_from_rec(
145  	union xfs_btree_key		*key,
146  	const union xfs_btree_rec	*rec)
147  {
148  	__u32				x;
149  
150  	x = be32_to_cpu(rec->alloc.ar_startblock);
151  	x += be32_to_cpu(rec->alloc.ar_blockcount) - 1;
152  	key->alloc.ar_startblock = cpu_to_be32(x);
153  	key->alloc.ar_blockcount = 0;
154  }
155  
156  STATIC void
157  xfs_cntbt_init_high_key_from_rec(
158  	union xfs_btree_key		*key,
159  	const union xfs_btree_rec	*rec)
160  {
161  	key->alloc.ar_blockcount = rec->alloc.ar_blockcount;
162  	key->alloc.ar_startblock = 0;
163  }
164  
165  STATIC void
166  xfs_allocbt_init_rec_from_cur(
167  	struct xfs_btree_cur	*cur,
168  	union xfs_btree_rec	*rec)
169  {
170  	rec->alloc.ar_startblock = cpu_to_be32(cur->bc_rec.a.ar_startblock);
171  	rec->alloc.ar_blockcount = cpu_to_be32(cur->bc_rec.a.ar_blockcount);
172  }
173  
174  STATIC void
175  xfs_allocbt_init_ptr_from_cur(
176  	struct xfs_btree_cur	*cur,
177  	union xfs_btree_ptr	*ptr)
178  {
179  	struct xfs_agf		*agf = cur->bc_ag.agbp->b_addr;
180  
181  	ASSERT(cur->bc_ag.pag->pag_agno == be32_to_cpu(agf->agf_seqno));
182  
183  	if (xfs_btree_is_bno(cur->bc_ops))
184  		ptr->s = agf->agf_bno_root;
185  	else
186  		ptr->s = agf->agf_cnt_root;
187  }
188  
189  STATIC int64_t
190  xfs_bnobt_key_diff(
191  	struct xfs_btree_cur		*cur,
192  	const union xfs_btree_key	*key)
193  {
194  	struct xfs_alloc_rec_incore	*rec = &cur->bc_rec.a;
195  	const struct xfs_alloc_rec	*kp = &key->alloc;
196  
197  	return (int64_t)be32_to_cpu(kp->ar_startblock) - rec->ar_startblock;
198  }
199  
200  STATIC int64_t
201  xfs_cntbt_key_diff(
202  	struct xfs_btree_cur		*cur,
203  	const union xfs_btree_key	*key)
204  {
205  	struct xfs_alloc_rec_incore	*rec = &cur->bc_rec.a;
206  	const struct xfs_alloc_rec	*kp = &key->alloc;
207  	int64_t				diff;
208  
209  	diff = (int64_t)be32_to_cpu(kp->ar_blockcount) - rec->ar_blockcount;
210  	if (diff)
211  		return diff;
212  
213  	return (int64_t)be32_to_cpu(kp->ar_startblock) - rec->ar_startblock;
214  }
215  
216  STATIC int64_t
217  xfs_bnobt_diff_two_keys(
218  	struct xfs_btree_cur		*cur,
219  	const union xfs_btree_key	*k1,
220  	const union xfs_btree_key	*k2,
221  	const union xfs_btree_key	*mask)
222  {
223  	ASSERT(!mask || mask->alloc.ar_startblock);
224  
225  	return (int64_t)be32_to_cpu(k1->alloc.ar_startblock) -
226  			be32_to_cpu(k2->alloc.ar_startblock);
227  }
228  
229  STATIC int64_t
230  xfs_cntbt_diff_two_keys(
231  	struct xfs_btree_cur		*cur,
232  	const union xfs_btree_key	*k1,
233  	const union xfs_btree_key	*k2,
234  	const union xfs_btree_key	*mask)
235  {
236  	int64_t				diff;
237  
238  	ASSERT(!mask || (mask->alloc.ar_blockcount &&
239  			 mask->alloc.ar_startblock));
240  
241  	diff =  be32_to_cpu(k1->alloc.ar_blockcount) -
242  		be32_to_cpu(k2->alloc.ar_blockcount);
243  	if (diff)
244  		return diff;
245  
246  	return  be32_to_cpu(k1->alloc.ar_startblock) -
247  		be32_to_cpu(k2->alloc.ar_startblock);
248  }
249  
250  static xfs_failaddr_t
251  xfs_allocbt_verify(
252  	struct xfs_buf		*bp)
253  {
254  	struct xfs_mount	*mp = bp->b_mount;
255  	struct xfs_btree_block	*block = XFS_BUF_TO_BLOCK(bp);
256  	struct xfs_perag	*pag = bp->b_pag;
257  	xfs_failaddr_t		fa;
258  	unsigned int		level;
259  
260  	if (!xfs_verify_magic(bp, block->bb_magic))
261  		return __this_address;
262  
263  	if (xfs_has_crc(mp)) {
264  		fa = xfs_btree_agblock_v5hdr_verify(bp);
265  		if (fa)
266  			return fa;
267  	}
268  
269  	/*
270  	 * The perag may not be attached during grow operations or fully
271  	 * initialized from the AGF during log recovery. Therefore we can only
272  	 * check against maximum tree depth from those contexts.
273  	 *
274  	 * Otherwise check against the per-tree limit. Peek at one of the
275  	 * verifier magic values to determine the type of tree we're verifying
276  	 * against.
277  	 */
278  	level = be16_to_cpu(block->bb_level);
279  	if (pag && xfs_perag_initialised_agf(pag)) {
280  		unsigned int	maxlevel, repair_maxlevel = 0;
281  
282  		/*
283  		 * Online repair could be rewriting the free space btrees, so
284  		 * we'll validate against the larger of either tree while this
285  		 * is going on.
286  		 */
287  		if (bp->b_ops->magic[0] == cpu_to_be32(XFS_ABTC_MAGIC)) {
288  			maxlevel = pag->pagf_cnt_level;
289  #ifdef CONFIG_XFS_ONLINE_REPAIR
290  			repair_maxlevel = pag->pagf_repair_cnt_level;
291  #endif
292  		} else {
293  			maxlevel = pag->pagf_bno_level;
294  #ifdef CONFIG_XFS_ONLINE_REPAIR
295  			repair_maxlevel = pag->pagf_repair_bno_level;
296  #endif
297  		}
298  
299  		if (level >= max(maxlevel, repair_maxlevel))
300  			return __this_address;
301  	} else if (level >= mp->m_alloc_maxlevels)
302  		return __this_address;
303  
304  	return xfs_btree_agblock_verify(bp, mp->m_alloc_mxr[level != 0]);
305  }
306  
307  static void
308  xfs_allocbt_read_verify(
309  	struct xfs_buf	*bp)
310  {
311  	xfs_failaddr_t	fa;
312  
313  	if (!xfs_btree_agblock_verify_crc(bp))
314  		xfs_verifier_error(bp, -EFSBADCRC, __this_address);
315  	else {
316  		fa = xfs_allocbt_verify(bp);
317  		if (fa)
318  			xfs_verifier_error(bp, -EFSCORRUPTED, fa);
319  	}
320  
321  	if (bp->b_error)
322  		trace_xfs_btree_corrupt(bp, _RET_IP_);
323  }
324  
325  static void
326  xfs_allocbt_write_verify(
327  	struct xfs_buf	*bp)
328  {
329  	xfs_failaddr_t	fa;
330  
331  	fa = xfs_allocbt_verify(bp);
332  	if (fa) {
333  		trace_xfs_btree_corrupt(bp, _RET_IP_);
334  		xfs_verifier_error(bp, -EFSCORRUPTED, fa);
335  		return;
336  	}
337  	xfs_btree_agblock_calc_crc(bp);
338  
339  }
340  
341  const struct xfs_buf_ops xfs_bnobt_buf_ops = {
342  	.name = "xfs_bnobt",
343  	.magic = { cpu_to_be32(XFS_ABTB_MAGIC),
344  		   cpu_to_be32(XFS_ABTB_CRC_MAGIC) },
345  	.verify_read = xfs_allocbt_read_verify,
346  	.verify_write = xfs_allocbt_write_verify,
347  	.verify_struct = xfs_allocbt_verify,
348  };
349  
350  const struct xfs_buf_ops xfs_cntbt_buf_ops = {
351  	.name = "xfs_cntbt",
352  	.magic = { cpu_to_be32(XFS_ABTC_MAGIC),
353  		   cpu_to_be32(XFS_ABTC_CRC_MAGIC) },
354  	.verify_read = xfs_allocbt_read_verify,
355  	.verify_write = xfs_allocbt_write_verify,
356  	.verify_struct = xfs_allocbt_verify,
357  };
358  
359  STATIC int
360  xfs_bnobt_keys_inorder(
361  	struct xfs_btree_cur		*cur,
362  	const union xfs_btree_key	*k1,
363  	const union xfs_btree_key	*k2)
364  {
365  	return be32_to_cpu(k1->alloc.ar_startblock) <
366  	       be32_to_cpu(k2->alloc.ar_startblock);
367  }
368  
369  STATIC int
370  xfs_bnobt_recs_inorder(
371  	struct xfs_btree_cur		*cur,
372  	const union xfs_btree_rec	*r1,
373  	const union xfs_btree_rec	*r2)
374  {
375  	return be32_to_cpu(r1->alloc.ar_startblock) +
376  		be32_to_cpu(r1->alloc.ar_blockcount) <=
377  		be32_to_cpu(r2->alloc.ar_startblock);
378  }
379  
380  STATIC int
381  xfs_cntbt_keys_inorder(
382  	struct xfs_btree_cur		*cur,
383  	const union xfs_btree_key	*k1,
384  	const union xfs_btree_key	*k2)
385  {
386  	return be32_to_cpu(k1->alloc.ar_blockcount) <
387  		be32_to_cpu(k2->alloc.ar_blockcount) ||
388  		(k1->alloc.ar_blockcount == k2->alloc.ar_blockcount &&
389  		 be32_to_cpu(k1->alloc.ar_startblock) <
390  		 be32_to_cpu(k2->alloc.ar_startblock));
391  }
392  
393  STATIC int
394  xfs_cntbt_recs_inorder(
395  	struct xfs_btree_cur		*cur,
396  	const union xfs_btree_rec	*r1,
397  	const union xfs_btree_rec	*r2)
398  {
399  	return be32_to_cpu(r1->alloc.ar_blockcount) <
400  		be32_to_cpu(r2->alloc.ar_blockcount) ||
401  		(r1->alloc.ar_blockcount == r2->alloc.ar_blockcount &&
402  		 be32_to_cpu(r1->alloc.ar_startblock) <
403  		 be32_to_cpu(r2->alloc.ar_startblock));
404  }
405  
406  STATIC enum xbtree_key_contig
407  xfs_allocbt_keys_contiguous(
408  	struct xfs_btree_cur		*cur,
409  	const union xfs_btree_key	*key1,
410  	const union xfs_btree_key	*key2,
411  	const union xfs_btree_key	*mask)
412  {
413  	ASSERT(!mask || mask->alloc.ar_startblock);
414  
415  	return xbtree_key_contig(be32_to_cpu(key1->alloc.ar_startblock),
416  				 be32_to_cpu(key2->alloc.ar_startblock));
417  }
418  
419  const struct xfs_btree_ops xfs_bnobt_ops = {
420  	.name			= "bno",
421  	.type			= XFS_BTREE_TYPE_AG,
422  
423  	.rec_len		= sizeof(xfs_alloc_rec_t),
424  	.key_len		= sizeof(xfs_alloc_key_t),
425  	.ptr_len		= XFS_BTREE_SHORT_PTR_LEN,
426  
427  	.lru_refs		= XFS_ALLOC_BTREE_REF,
428  	.statoff		= XFS_STATS_CALC_INDEX(xs_abtb_2),
429  	.sick_mask		= XFS_SICK_AG_BNOBT,
430  
431  	.dup_cursor		= xfs_bnobt_dup_cursor,
432  	.set_root		= xfs_allocbt_set_root,
433  	.alloc_block		= xfs_allocbt_alloc_block,
434  	.free_block		= xfs_allocbt_free_block,
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  	.keys_contiguous	= xfs_allocbt_keys_contiguous,
447  };
448  
449  const struct xfs_btree_ops xfs_cntbt_ops = {
450  	.name			= "cnt",
451  	.type			= XFS_BTREE_TYPE_AG,
452  
453  	.rec_len		= sizeof(xfs_alloc_rec_t),
454  	.key_len		= sizeof(xfs_alloc_key_t),
455  	.ptr_len		= XFS_BTREE_SHORT_PTR_LEN,
456  
457  	.lru_refs		= XFS_ALLOC_BTREE_REF,
458  	.statoff		= XFS_STATS_CALC_INDEX(xs_abtc_2),
459  	.sick_mask		= XFS_SICK_AG_CNTBT,
460  
461  	.dup_cursor		= xfs_cntbt_dup_cursor,
462  	.set_root		= xfs_allocbt_set_root,
463  	.alloc_block		= xfs_allocbt_alloc_block,
464  	.free_block		= xfs_allocbt_free_block,
465  	.get_minrecs		= xfs_allocbt_get_minrecs,
466  	.get_maxrecs		= xfs_allocbt_get_maxrecs,
467  	.init_key_from_rec	= xfs_allocbt_init_key_from_rec,
468  	.init_high_key_from_rec	= xfs_cntbt_init_high_key_from_rec,
469  	.init_rec_from_cur	= xfs_allocbt_init_rec_from_cur,
470  	.init_ptr_from_cur	= xfs_allocbt_init_ptr_from_cur,
471  	.key_diff		= xfs_cntbt_key_diff,
472  	.buf_ops		= &xfs_cntbt_buf_ops,
473  	.diff_two_keys		= xfs_cntbt_diff_two_keys,
474  	.keys_inorder		= xfs_cntbt_keys_inorder,
475  	.recs_inorder		= xfs_cntbt_recs_inorder,
476  	.keys_contiguous	= NULL, /* not needed right now */
477  };
478  
479  /*
480   * Allocate a new bnobt cursor.
481   *
482   * For staging cursors tp and agbp are NULL.
483   */
484  struct xfs_btree_cur *
485  xfs_bnobt_init_cursor(
486  	struct xfs_mount	*mp,
487  	struct xfs_trans	*tp,
488  	struct xfs_buf		*agbp,
489  	struct xfs_perag	*pag)
490  {
491  	struct xfs_btree_cur	*cur;
492  
493  	cur = xfs_btree_alloc_cursor(mp, tp, &xfs_bnobt_ops,
494  			mp->m_alloc_maxlevels, xfs_allocbt_cur_cache);
495  	cur->bc_ag.pag = xfs_perag_hold(pag);
496  	cur->bc_ag.agbp = agbp;
497  	if (agbp) {
498  		struct xfs_agf		*agf = agbp->b_addr;
499  
500  		cur->bc_nlevels = be32_to_cpu(agf->agf_bno_level);
501  	}
502  	return cur;
503  }
504  
505  /*
506   * Allocate a new cntbt cursor.
507   *
508   * For staging cursors tp and agbp are NULL.
509   */
510  struct xfs_btree_cur *
511  xfs_cntbt_init_cursor(
512  	struct xfs_mount	*mp,
513  	struct xfs_trans	*tp,
514  	struct xfs_buf		*agbp,
515  	struct xfs_perag	*pag)
516  {
517  	struct xfs_btree_cur	*cur;
518  
519  	cur = xfs_btree_alloc_cursor(mp, tp, &xfs_cntbt_ops,
520  			mp->m_alloc_maxlevels, xfs_allocbt_cur_cache);
521  	cur->bc_ag.pag = xfs_perag_hold(pag);
522  	cur->bc_ag.agbp = agbp;
523  	if (agbp) {
524  		struct xfs_agf		*agf = agbp->b_addr;
525  
526  		cur->bc_nlevels = be32_to_cpu(agf->agf_cnt_level);
527  	}
528  	return cur;
529  }
530  
531  /*
532   * Install a new free space btree root.  Caller is responsible for invalidating
533   * and freeing the old btree blocks.
534   */
535  void
536  xfs_allocbt_commit_staged_btree(
537  	struct xfs_btree_cur	*cur,
538  	struct xfs_trans	*tp,
539  	struct xfs_buf		*agbp)
540  {
541  	struct xfs_agf		*agf = agbp->b_addr;
542  	struct xbtree_afakeroot	*afake = cur->bc_ag.afake;
543  
544  	ASSERT(cur->bc_flags & XFS_BTREE_STAGING);
545  
546  	if (xfs_btree_is_bno(cur->bc_ops)) {
547  		agf->agf_bno_root = cpu_to_be32(afake->af_root);
548  		agf->agf_bno_level = cpu_to_be32(afake->af_levels);
549  	} else {
550  		agf->agf_cnt_root = cpu_to_be32(afake->af_root);
551  		agf->agf_cnt_level = cpu_to_be32(afake->af_levels);
552  	}
553  	xfs_alloc_log_agf(tp, agbp, XFS_AGF_ROOTS | XFS_AGF_LEVELS);
554  
555  	xfs_btree_commit_afakeroot(cur, tp, agbp);
556  }
557  
558  /* Calculate number of records in an alloc btree block. */
559  static inline unsigned int
560  xfs_allocbt_block_maxrecs(
561  	unsigned int		blocklen,
562  	bool			leaf)
563  {
564  	if (leaf)
565  		return blocklen / sizeof(xfs_alloc_rec_t);
566  	return blocklen / (sizeof(xfs_alloc_key_t) + sizeof(xfs_alloc_ptr_t));
567  }
568  
569  /*
570   * Calculate number of records in an alloc btree block.
571   */
572  int
573  xfs_allocbt_maxrecs(
574  	struct xfs_mount	*mp,
575  	int			blocklen,
576  	int			leaf)
577  {
578  	blocklen -= XFS_ALLOC_BLOCK_LEN(mp);
579  	return xfs_allocbt_block_maxrecs(blocklen, leaf);
580  }
581  
582  /* Free space btrees are at their largest when every other block is free. */
583  #define XFS_MAX_FREESP_RECORDS	((XFS_MAX_AG_BLOCKS + 1) / 2)
584  
585  /* Compute the max possible height for free space btrees. */
586  unsigned int
587  xfs_allocbt_maxlevels_ondisk(void)
588  {
589  	unsigned int		minrecs[2];
590  	unsigned int		blocklen;
591  
592  	blocklen = min(XFS_MIN_BLOCKSIZE - XFS_BTREE_SBLOCK_LEN,
593  		       XFS_MIN_CRC_BLOCKSIZE - XFS_BTREE_SBLOCK_CRC_LEN);
594  
595  	minrecs[0] = xfs_allocbt_block_maxrecs(blocklen, true) / 2;
596  	minrecs[1] = xfs_allocbt_block_maxrecs(blocklen, false) / 2;
597  
598  	return xfs_btree_compute_maxlevels(minrecs, XFS_MAX_FREESP_RECORDS);
599  }
600  
601  /* Calculate the freespace btree size for some records. */
602  xfs_extlen_t
603  xfs_allocbt_calc_size(
604  	struct xfs_mount	*mp,
605  	unsigned long long	len)
606  {
607  	return xfs_btree_calc_size(mp->m_alloc_mnr, len);
608  }
609  
610  int __init
611  xfs_allocbt_init_cur_cache(void)
612  {
613  	xfs_allocbt_cur_cache = kmem_cache_create("xfs_bnobt_cur",
614  			xfs_btree_cur_sizeof(xfs_allocbt_maxlevels_ondisk()),
615  			0, 0, NULL);
616  
617  	if (!xfs_allocbt_cur_cache)
618  		return -ENOMEM;
619  	return 0;
620  }
621  
622  void
623  xfs_allocbt_destroy_cur_cache(void)
624  {
625  	kmem_cache_destroy(xfs_allocbt_cur_cache);
626  	xfs_allocbt_cur_cache = NULL;
627  }
628