xref: /openbmc/linux/fs/xfs/libxfs/xfs_ialloc_btree.c (revision 4eb5928d)
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_bit.h"
13 #include "xfs_mount.h"
14 #include "xfs_btree.h"
15 #include "xfs_btree_staging.h"
16 #include "xfs_ialloc.h"
17 #include "xfs_ialloc_btree.h"
18 #include "xfs_alloc.h"
19 #include "xfs_error.h"
20 #include "xfs_trace.h"
21 #include "xfs_trans.h"
22 #include "xfs_rmap.h"
23 
24 STATIC int
25 xfs_inobt_get_minrecs(
26 	struct xfs_btree_cur	*cur,
27 	int			level)
28 {
29 	return M_IGEO(cur->bc_mp)->inobt_mnr[level != 0];
30 }
31 
32 STATIC struct xfs_btree_cur *
33 xfs_inobt_dup_cursor(
34 	struct xfs_btree_cur	*cur)
35 {
36 	return xfs_inobt_init_cursor(cur->bc_mp, cur->bc_tp,
37 			cur->bc_ag.agbp, cur->bc_ag.agno,
38 			cur->bc_btnum);
39 }
40 
41 STATIC void
42 xfs_inobt_set_root(
43 	struct xfs_btree_cur	*cur,
44 	union xfs_btree_ptr	*nptr,
45 	int			inc)	/* level change */
46 {
47 	struct xfs_buf		*agbp = cur->bc_ag.agbp;
48 	struct xfs_agi		*agi = agbp->b_addr;
49 
50 	agi->agi_root = nptr->s;
51 	be32_add_cpu(&agi->agi_level, inc);
52 	xfs_ialloc_log_agi(cur->bc_tp, agbp, XFS_AGI_ROOT | XFS_AGI_LEVEL);
53 }
54 
55 STATIC void
56 xfs_finobt_set_root(
57 	struct xfs_btree_cur	*cur,
58 	union xfs_btree_ptr	*nptr,
59 	int			inc)	/* level change */
60 {
61 	struct xfs_buf		*agbp = cur->bc_ag.agbp;
62 	struct xfs_agi		*agi = agbp->b_addr;
63 
64 	agi->agi_free_root = nptr->s;
65 	be32_add_cpu(&agi->agi_free_level, inc);
66 	xfs_ialloc_log_agi(cur->bc_tp, agbp,
67 			   XFS_AGI_FREE_ROOT | XFS_AGI_FREE_LEVEL);
68 }
69 
70 STATIC int
71 __xfs_inobt_alloc_block(
72 	struct xfs_btree_cur	*cur,
73 	union xfs_btree_ptr	*start,
74 	union xfs_btree_ptr	*new,
75 	int			*stat,
76 	enum xfs_ag_resv_type	resv)
77 {
78 	xfs_alloc_arg_t		args;		/* block allocation args */
79 	int			error;		/* error return value */
80 	xfs_agblock_t		sbno = be32_to_cpu(start->s);
81 
82 	memset(&args, 0, sizeof(args));
83 	args.tp = cur->bc_tp;
84 	args.mp = cur->bc_mp;
85 	args.oinfo = XFS_RMAP_OINFO_INOBT;
86 	args.fsbno = XFS_AGB_TO_FSB(args.mp, cur->bc_ag.agno, sbno);
87 	args.minlen = 1;
88 	args.maxlen = 1;
89 	args.prod = 1;
90 	args.type = XFS_ALLOCTYPE_NEAR_BNO;
91 	args.resv = resv;
92 
93 	error = xfs_alloc_vextent(&args);
94 	if (error)
95 		return error;
96 
97 	if (args.fsbno == NULLFSBLOCK) {
98 		*stat = 0;
99 		return 0;
100 	}
101 	ASSERT(args.len == 1);
102 
103 	new->s = cpu_to_be32(XFS_FSB_TO_AGBNO(args.mp, args.fsbno));
104 	*stat = 1;
105 	return 0;
106 }
107 
108 STATIC int
109 xfs_inobt_alloc_block(
110 	struct xfs_btree_cur	*cur,
111 	union xfs_btree_ptr	*start,
112 	union xfs_btree_ptr	*new,
113 	int			*stat)
114 {
115 	return __xfs_inobt_alloc_block(cur, start, new, stat, XFS_AG_RESV_NONE);
116 }
117 
118 STATIC int
119 xfs_finobt_alloc_block(
120 	struct xfs_btree_cur	*cur,
121 	union xfs_btree_ptr	*start,
122 	union xfs_btree_ptr	*new,
123 	int			*stat)
124 {
125 	if (cur->bc_mp->m_finobt_nores)
126 		return xfs_inobt_alloc_block(cur, start, new, stat);
127 	return __xfs_inobt_alloc_block(cur, start, new, stat,
128 			XFS_AG_RESV_METADATA);
129 }
130 
131 STATIC int
132 __xfs_inobt_free_block(
133 	struct xfs_btree_cur	*cur,
134 	struct xfs_buf		*bp,
135 	enum xfs_ag_resv_type	resv)
136 {
137 	return xfs_free_extent(cur->bc_tp,
138 			XFS_DADDR_TO_FSB(cur->bc_mp, XFS_BUF_ADDR(bp)), 1,
139 			&XFS_RMAP_OINFO_INOBT, resv);
140 }
141 
142 STATIC int
143 xfs_inobt_free_block(
144 	struct xfs_btree_cur	*cur,
145 	struct xfs_buf		*bp)
146 {
147 	return __xfs_inobt_free_block(cur, bp, XFS_AG_RESV_NONE);
148 }
149 
150 STATIC int
151 xfs_finobt_free_block(
152 	struct xfs_btree_cur	*cur,
153 	struct xfs_buf		*bp)
154 {
155 	if (cur->bc_mp->m_finobt_nores)
156 		return xfs_inobt_free_block(cur, bp);
157 	return __xfs_inobt_free_block(cur, bp, XFS_AG_RESV_METADATA);
158 }
159 
160 STATIC int
161 xfs_inobt_get_maxrecs(
162 	struct xfs_btree_cur	*cur,
163 	int			level)
164 {
165 	return M_IGEO(cur->bc_mp)->inobt_mxr[level != 0];
166 }
167 
168 STATIC void
169 xfs_inobt_init_key_from_rec(
170 	union xfs_btree_key	*key,
171 	union xfs_btree_rec	*rec)
172 {
173 	key->inobt.ir_startino = rec->inobt.ir_startino;
174 }
175 
176 STATIC void
177 xfs_inobt_init_high_key_from_rec(
178 	union xfs_btree_key	*key,
179 	union xfs_btree_rec	*rec)
180 {
181 	__u32			x;
182 
183 	x = be32_to_cpu(rec->inobt.ir_startino);
184 	x += XFS_INODES_PER_CHUNK - 1;
185 	key->inobt.ir_startino = cpu_to_be32(x);
186 }
187 
188 STATIC void
189 xfs_inobt_init_rec_from_cur(
190 	struct xfs_btree_cur	*cur,
191 	union xfs_btree_rec	*rec)
192 {
193 	rec->inobt.ir_startino = cpu_to_be32(cur->bc_rec.i.ir_startino);
194 	if (xfs_sb_version_hassparseinodes(&cur->bc_mp->m_sb)) {
195 		rec->inobt.ir_u.sp.ir_holemask =
196 					cpu_to_be16(cur->bc_rec.i.ir_holemask);
197 		rec->inobt.ir_u.sp.ir_count = cur->bc_rec.i.ir_count;
198 		rec->inobt.ir_u.sp.ir_freecount = cur->bc_rec.i.ir_freecount;
199 	} else {
200 		/* ir_holemask/ir_count not supported on-disk */
201 		rec->inobt.ir_u.f.ir_freecount =
202 					cpu_to_be32(cur->bc_rec.i.ir_freecount);
203 	}
204 	rec->inobt.ir_free = cpu_to_be64(cur->bc_rec.i.ir_free);
205 }
206 
207 /*
208  * initial value of ptr for lookup
209  */
210 STATIC void
211 xfs_inobt_init_ptr_from_cur(
212 	struct xfs_btree_cur	*cur,
213 	union xfs_btree_ptr	*ptr)
214 {
215 	struct xfs_agi		*agi = cur->bc_ag.agbp->b_addr;
216 
217 	ASSERT(cur->bc_ag.agno == be32_to_cpu(agi->agi_seqno));
218 
219 	ptr->s = agi->agi_root;
220 }
221 
222 STATIC void
223 xfs_finobt_init_ptr_from_cur(
224 	struct xfs_btree_cur	*cur,
225 	union xfs_btree_ptr	*ptr)
226 {
227 	struct xfs_agi		*agi = cur->bc_ag.agbp->b_addr;
228 
229 	ASSERT(cur->bc_ag.agno == be32_to_cpu(agi->agi_seqno));
230 	ptr->s = agi->agi_free_root;
231 }
232 
233 STATIC int64_t
234 xfs_inobt_key_diff(
235 	struct xfs_btree_cur	*cur,
236 	union xfs_btree_key	*key)
237 {
238 	return (int64_t)be32_to_cpu(key->inobt.ir_startino) -
239 			  cur->bc_rec.i.ir_startino;
240 }
241 
242 STATIC int64_t
243 xfs_inobt_diff_two_keys(
244 	struct xfs_btree_cur	*cur,
245 	union xfs_btree_key	*k1,
246 	union xfs_btree_key	*k2)
247 {
248 	return (int64_t)be32_to_cpu(k1->inobt.ir_startino) -
249 			  be32_to_cpu(k2->inobt.ir_startino);
250 }
251 
252 static xfs_failaddr_t
253 xfs_inobt_verify(
254 	struct xfs_buf		*bp)
255 {
256 	struct xfs_mount	*mp = bp->b_mount;
257 	struct xfs_btree_block	*block = XFS_BUF_TO_BLOCK(bp);
258 	xfs_failaddr_t		fa;
259 	unsigned int		level;
260 
261 	if (!xfs_verify_magic(bp, block->bb_magic))
262 		return __this_address;
263 
264 	/*
265 	 * During growfs operations, we can't verify the exact owner as the
266 	 * perag is not fully initialised and hence not attached to the buffer.
267 	 *
268 	 * Similarly, during log recovery we will have a perag structure
269 	 * attached, but the agi information will not yet have been initialised
270 	 * from the on disk AGI. We don't currently use any of this information,
271 	 * but beware of the landmine (i.e. need to check pag->pagi_init) if we
272 	 * ever do.
273 	 */
274 	if (xfs_sb_version_hascrc(&mp->m_sb)) {
275 		fa = xfs_btree_sblock_v5hdr_verify(bp);
276 		if (fa)
277 			return fa;
278 	}
279 
280 	/* level verification */
281 	level = be16_to_cpu(block->bb_level);
282 	if (level >= M_IGEO(mp)->inobt_maxlevels)
283 		return __this_address;
284 
285 	return xfs_btree_sblock_verify(bp,
286 			M_IGEO(mp)->inobt_mxr[level != 0]);
287 }
288 
289 static void
290 xfs_inobt_read_verify(
291 	struct xfs_buf	*bp)
292 {
293 	xfs_failaddr_t	fa;
294 
295 	if (!xfs_btree_sblock_verify_crc(bp))
296 		xfs_verifier_error(bp, -EFSBADCRC, __this_address);
297 	else {
298 		fa = xfs_inobt_verify(bp);
299 		if (fa)
300 			xfs_verifier_error(bp, -EFSCORRUPTED, fa);
301 	}
302 
303 	if (bp->b_error)
304 		trace_xfs_btree_corrupt(bp, _RET_IP_);
305 }
306 
307 static void
308 xfs_inobt_write_verify(
309 	struct xfs_buf	*bp)
310 {
311 	xfs_failaddr_t	fa;
312 
313 	fa = xfs_inobt_verify(bp);
314 	if (fa) {
315 		trace_xfs_btree_corrupt(bp, _RET_IP_);
316 		xfs_verifier_error(bp, -EFSCORRUPTED, fa);
317 		return;
318 	}
319 	xfs_btree_sblock_calc_crc(bp);
320 
321 }
322 
323 const struct xfs_buf_ops xfs_inobt_buf_ops = {
324 	.name = "xfs_inobt",
325 	.magic = { cpu_to_be32(XFS_IBT_MAGIC), cpu_to_be32(XFS_IBT_CRC_MAGIC) },
326 	.verify_read = xfs_inobt_read_verify,
327 	.verify_write = xfs_inobt_write_verify,
328 	.verify_struct = xfs_inobt_verify,
329 };
330 
331 const struct xfs_buf_ops xfs_finobt_buf_ops = {
332 	.name = "xfs_finobt",
333 	.magic = { cpu_to_be32(XFS_FIBT_MAGIC),
334 		   cpu_to_be32(XFS_FIBT_CRC_MAGIC) },
335 	.verify_read = xfs_inobt_read_verify,
336 	.verify_write = xfs_inobt_write_verify,
337 	.verify_struct = xfs_inobt_verify,
338 };
339 
340 STATIC int
341 xfs_inobt_keys_inorder(
342 	struct xfs_btree_cur	*cur,
343 	union xfs_btree_key	*k1,
344 	union xfs_btree_key	*k2)
345 {
346 	return be32_to_cpu(k1->inobt.ir_startino) <
347 		be32_to_cpu(k2->inobt.ir_startino);
348 }
349 
350 STATIC int
351 xfs_inobt_recs_inorder(
352 	struct xfs_btree_cur	*cur,
353 	union xfs_btree_rec	*r1,
354 	union xfs_btree_rec	*r2)
355 {
356 	return be32_to_cpu(r1->inobt.ir_startino) + XFS_INODES_PER_CHUNK <=
357 		be32_to_cpu(r2->inobt.ir_startino);
358 }
359 
360 static const struct xfs_btree_ops xfs_inobt_ops = {
361 	.rec_len		= sizeof(xfs_inobt_rec_t),
362 	.key_len		= sizeof(xfs_inobt_key_t),
363 
364 	.dup_cursor		= xfs_inobt_dup_cursor,
365 	.set_root		= xfs_inobt_set_root,
366 	.alloc_block		= xfs_inobt_alloc_block,
367 	.free_block		= xfs_inobt_free_block,
368 	.get_minrecs		= xfs_inobt_get_minrecs,
369 	.get_maxrecs		= xfs_inobt_get_maxrecs,
370 	.init_key_from_rec	= xfs_inobt_init_key_from_rec,
371 	.init_high_key_from_rec	= xfs_inobt_init_high_key_from_rec,
372 	.init_rec_from_cur	= xfs_inobt_init_rec_from_cur,
373 	.init_ptr_from_cur	= xfs_inobt_init_ptr_from_cur,
374 	.key_diff		= xfs_inobt_key_diff,
375 	.buf_ops		= &xfs_inobt_buf_ops,
376 	.diff_two_keys		= xfs_inobt_diff_two_keys,
377 	.keys_inorder		= xfs_inobt_keys_inorder,
378 	.recs_inorder		= xfs_inobt_recs_inorder,
379 };
380 
381 static const struct xfs_btree_ops xfs_finobt_ops = {
382 	.rec_len		= sizeof(xfs_inobt_rec_t),
383 	.key_len		= sizeof(xfs_inobt_key_t),
384 
385 	.dup_cursor		= xfs_inobt_dup_cursor,
386 	.set_root		= xfs_finobt_set_root,
387 	.alloc_block		= xfs_finobt_alloc_block,
388 	.free_block		= xfs_finobt_free_block,
389 	.get_minrecs		= xfs_inobt_get_minrecs,
390 	.get_maxrecs		= xfs_inobt_get_maxrecs,
391 	.init_key_from_rec	= xfs_inobt_init_key_from_rec,
392 	.init_high_key_from_rec	= xfs_inobt_init_high_key_from_rec,
393 	.init_rec_from_cur	= xfs_inobt_init_rec_from_cur,
394 	.init_ptr_from_cur	= xfs_finobt_init_ptr_from_cur,
395 	.key_diff		= xfs_inobt_key_diff,
396 	.buf_ops		= &xfs_finobt_buf_ops,
397 	.diff_two_keys		= xfs_inobt_diff_two_keys,
398 	.keys_inorder		= xfs_inobt_keys_inorder,
399 	.recs_inorder		= xfs_inobt_recs_inorder,
400 };
401 
402 /*
403  * Initialize a new inode btree cursor.
404  */
405 static struct xfs_btree_cur *
406 xfs_inobt_init_common(
407 	struct xfs_mount	*mp,		/* file system mount point */
408 	struct xfs_trans	*tp,		/* transaction pointer */
409 	xfs_agnumber_t		agno,		/* allocation group number */
410 	xfs_btnum_t		btnum)		/* ialloc or free ino btree */
411 {
412 	struct xfs_btree_cur	*cur;
413 
414 	cur = kmem_cache_zalloc(xfs_btree_cur_zone, GFP_NOFS | __GFP_NOFAIL);
415 	cur->bc_tp = tp;
416 	cur->bc_mp = mp;
417 	cur->bc_btnum = btnum;
418 	if (btnum == XFS_BTNUM_INO) {
419 		cur->bc_statoff = XFS_STATS_CALC_INDEX(xs_ibt_2);
420 		cur->bc_ops = &xfs_inobt_ops;
421 	} else {
422 		cur->bc_statoff = XFS_STATS_CALC_INDEX(xs_fibt_2);
423 		cur->bc_ops = &xfs_finobt_ops;
424 	}
425 
426 	cur->bc_blocklog = mp->m_sb.sb_blocklog;
427 
428 	if (xfs_sb_version_hascrc(&mp->m_sb))
429 		cur->bc_flags |= XFS_BTREE_CRC_BLOCKS;
430 
431 	cur->bc_ag.agno = agno;
432 	return cur;
433 }
434 
435 /* Create an inode btree cursor. */
436 struct xfs_btree_cur *
437 xfs_inobt_init_cursor(
438 	struct xfs_mount	*mp,
439 	struct xfs_trans	*tp,
440 	struct xfs_buf		*agbp,
441 	xfs_agnumber_t		agno,
442 	xfs_btnum_t		btnum)
443 {
444 	struct xfs_btree_cur	*cur;
445 	struct xfs_agi		*agi = agbp->b_addr;
446 
447 	cur = xfs_inobt_init_common(mp, tp, agno, btnum);
448 	if (btnum == XFS_BTNUM_INO)
449 		cur->bc_nlevels = be32_to_cpu(agi->agi_level);
450 	else
451 		cur->bc_nlevels = be32_to_cpu(agi->agi_free_level);
452 	cur->bc_ag.agbp = agbp;
453 	return cur;
454 }
455 
456 /* Create an inode btree cursor with a fake root for staging. */
457 struct xfs_btree_cur *
458 xfs_inobt_stage_cursor(
459 	struct xfs_mount	*mp,
460 	struct xbtree_afakeroot	*afake,
461 	xfs_agnumber_t		agno,
462 	xfs_btnum_t		btnum)
463 {
464 	struct xfs_btree_cur	*cur;
465 
466 	cur = xfs_inobt_init_common(mp, NULL, agno, btnum);
467 	xfs_btree_stage_afakeroot(cur, afake);
468 	return cur;
469 }
470 
471 /*
472  * Install a new inobt btree root.  Caller is responsible for invalidating
473  * and freeing the old btree blocks.
474  */
475 void
476 xfs_inobt_commit_staged_btree(
477 	struct xfs_btree_cur	*cur,
478 	struct xfs_trans	*tp,
479 	struct xfs_buf		*agbp)
480 {
481 	struct xfs_agi		*agi = agbp->b_addr;
482 	struct xbtree_afakeroot	*afake = cur->bc_ag.afake;
483 
484 	ASSERT(cur->bc_flags & XFS_BTREE_STAGING);
485 
486 	if (cur->bc_btnum == XFS_BTNUM_INO) {
487 		agi->agi_root = cpu_to_be32(afake->af_root);
488 		agi->agi_level = cpu_to_be32(afake->af_levels);
489 		xfs_ialloc_log_agi(tp, agbp, XFS_AGI_ROOT | XFS_AGI_LEVEL);
490 		xfs_btree_commit_afakeroot(cur, tp, agbp, &xfs_inobt_ops);
491 	} else {
492 		agi->agi_free_root = cpu_to_be32(afake->af_root);
493 		agi->agi_free_level = cpu_to_be32(afake->af_levels);
494 		xfs_ialloc_log_agi(tp, agbp, XFS_AGI_FREE_ROOT |
495 					     XFS_AGI_FREE_LEVEL);
496 		xfs_btree_commit_afakeroot(cur, tp, agbp, &xfs_finobt_ops);
497 	}
498 }
499 
500 /*
501  * Calculate number of records in an inobt btree block.
502  */
503 int
504 xfs_inobt_maxrecs(
505 	struct xfs_mount	*mp,
506 	int			blocklen,
507 	int			leaf)
508 {
509 	blocklen -= XFS_INOBT_BLOCK_LEN(mp);
510 
511 	if (leaf)
512 		return blocklen / sizeof(xfs_inobt_rec_t);
513 	return blocklen / (sizeof(xfs_inobt_key_t) + sizeof(xfs_inobt_ptr_t));
514 }
515 
516 /*
517  * Convert the inode record holemask to an inode allocation bitmap. The inode
518  * allocation bitmap is inode granularity and specifies whether an inode is
519  * physically allocated on disk (not whether the inode is considered allocated
520  * or free by the fs).
521  *
522  * A bit value of 1 means the inode is allocated, a value of 0 means it is free.
523  */
524 uint64_t
525 xfs_inobt_irec_to_allocmask(
526 	struct xfs_inobt_rec_incore	*rec)
527 {
528 	uint64_t			bitmap = 0;
529 	uint64_t			inodespbit;
530 	int				nextbit;
531 	uint				allocbitmap;
532 
533 	/*
534 	 * The holemask has 16-bits for a 64 inode record. Therefore each
535 	 * holemask bit represents multiple inodes. Create a mask of bits to set
536 	 * in the allocmask for each holemask bit.
537 	 */
538 	inodespbit = (1 << XFS_INODES_PER_HOLEMASK_BIT) - 1;
539 
540 	/*
541 	 * Allocated inodes are represented by 0 bits in holemask. Invert the 0
542 	 * bits to 1 and convert to a uint so we can use xfs_next_bit(). Mask
543 	 * anything beyond the 16 holemask bits since this casts to a larger
544 	 * type.
545 	 */
546 	allocbitmap = ~rec->ir_holemask & ((1 << XFS_INOBT_HOLEMASK_BITS) - 1);
547 
548 	/*
549 	 * allocbitmap is the inverted holemask so every set bit represents
550 	 * allocated inodes. To expand from 16-bit holemask granularity to
551 	 * 64-bit (e.g., bit-per-inode), set inodespbit bits in the target
552 	 * bitmap for every holemask bit.
553 	 */
554 	nextbit = xfs_next_bit(&allocbitmap, 1, 0);
555 	while (nextbit != -1) {
556 		ASSERT(nextbit < (sizeof(rec->ir_holemask) * NBBY));
557 
558 		bitmap |= (inodespbit <<
559 			   (nextbit * XFS_INODES_PER_HOLEMASK_BIT));
560 
561 		nextbit = xfs_next_bit(&allocbitmap, 1, nextbit + 1);
562 	}
563 
564 	return bitmap;
565 }
566 
567 #if defined(DEBUG) || defined(XFS_WARN)
568 /*
569  * Verify that an in-core inode record has a valid inode count.
570  */
571 int
572 xfs_inobt_rec_check_count(
573 	struct xfs_mount		*mp,
574 	struct xfs_inobt_rec_incore	*rec)
575 {
576 	int				inocount = 0;
577 	int				nextbit = 0;
578 	uint64_t			allocbmap;
579 	int				wordsz;
580 
581 	wordsz = sizeof(allocbmap) / sizeof(unsigned int);
582 	allocbmap = xfs_inobt_irec_to_allocmask(rec);
583 
584 	nextbit = xfs_next_bit((uint *) &allocbmap, wordsz, nextbit);
585 	while (nextbit != -1) {
586 		inocount++;
587 		nextbit = xfs_next_bit((uint *) &allocbmap, wordsz,
588 				       nextbit + 1);
589 	}
590 
591 	if (inocount != rec->ir_count)
592 		return -EFSCORRUPTED;
593 
594 	return 0;
595 }
596 #endif	/* DEBUG */
597 
598 static xfs_extlen_t
599 xfs_inobt_max_size(
600 	struct xfs_mount	*mp,
601 	xfs_agnumber_t		agno)
602 {
603 	xfs_agblock_t		agblocks = xfs_ag_block_count(mp, agno);
604 
605 	/* Bail out if we're uninitialized, which can happen in mkfs. */
606 	if (M_IGEO(mp)->inobt_mxr[0] == 0)
607 		return 0;
608 
609 	/*
610 	 * The log is permanently allocated, so the space it occupies will
611 	 * never be available for the kinds of things that would require btree
612 	 * expansion.  We therefore can pretend the space isn't there.
613 	 */
614 	if (mp->m_sb.sb_logstart &&
615 	    XFS_FSB_TO_AGNO(mp, mp->m_sb.sb_logstart) == agno)
616 		agblocks -= mp->m_sb.sb_logblocks;
617 
618 	return xfs_btree_calc_size(M_IGEO(mp)->inobt_mnr,
619 				(uint64_t)agblocks * mp->m_sb.sb_inopblock /
620 					XFS_INODES_PER_CHUNK);
621 }
622 
623 /* Read AGI and create inobt cursor. */
624 int
625 xfs_inobt_cur(
626 	struct xfs_mount	*mp,
627 	struct xfs_trans	*tp,
628 	xfs_agnumber_t		agno,
629 	xfs_btnum_t		which,
630 	struct xfs_btree_cur	**curpp,
631 	struct xfs_buf		**agi_bpp)
632 {
633 	struct xfs_btree_cur	*cur;
634 	int			error;
635 
636 	ASSERT(*agi_bpp == NULL);
637 	ASSERT(*curpp == NULL);
638 
639 	error = xfs_ialloc_read_agi(mp, tp, agno, agi_bpp);
640 	if (error)
641 		return error;
642 
643 	cur = xfs_inobt_init_cursor(mp, tp, *agi_bpp, agno, which);
644 	if (!cur) {
645 		xfs_trans_brelse(tp, *agi_bpp);
646 		*agi_bpp = NULL;
647 		return -ENOMEM;
648 	}
649 	*curpp = cur;
650 	return 0;
651 }
652 
653 static int
654 xfs_inobt_count_blocks(
655 	struct xfs_mount	*mp,
656 	struct xfs_trans	*tp,
657 	xfs_agnumber_t		agno,
658 	xfs_btnum_t		btnum,
659 	xfs_extlen_t		*tree_blocks)
660 {
661 	struct xfs_buf		*agbp = NULL;
662 	struct xfs_btree_cur	*cur = NULL;
663 	int			error;
664 
665 	error = xfs_inobt_cur(mp, tp, agno, btnum, &cur, &agbp);
666 	if (error)
667 		return error;
668 
669 	error = xfs_btree_count_blocks(cur, tree_blocks);
670 	xfs_btree_del_cursor(cur, error);
671 	xfs_trans_brelse(tp, agbp);
672 
673 	return error;
674 }
675 
676 /*
677  * Figure out how many blocks to reserve and how many are used by this btree.
678  */
679 int
680 xfs_finobt_calc_reserves(
681 	struct xfs_mount	*mp,
682 	struct xfs_trans	*tp,
683 	xfs_agnumber_t		agno,
684 	xfs_extlen_t		*ask,
685 	xfs_extlen_t		*used)
686 {
687 	xfs_extlen_t		tree_len = 0;
688 	int			error;
689 
690 	if (!xfs_sb_version_hasfinobt(&mp->m_sb))
691 		return 0;
692 
693 	error = xfs_inobt_count_blocks(mp, tp, agno, XFS_BTNUM_FINO, &tree_len);
694 	if (error)
695 		return error;
696 
697 	*ask += xfs_inobt_max_size(mp, agno);
698 	*used += tree_len;
699 	return 0;
700 }
701 
702 /* Calculate the inobt btree size for some records. */
703 xfs_extlen_t
704 xfs_iallocbt_calc_size(
705 	struct xfs_mount	*mp,
706 	unsigned long long	len)
707 {
708 	return xfs_btree_calc_size(M_IGEO(mp)->inobt_mnr, len);
709 }
710