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_btree.h"
14 #include "xfs_btree_staging.h"
15 #include "xfs_refcount_btree.h"
16 #include "xfs_alloc.h"
17 #include "xfs_error.h"
18 #include "xfs_trace.h"
19 #include "xfs_trans.h"
20 #include "xfs_bit.h"
21 #include "xfs_rmap.h"
22 #include "xfs_ag.h"
23 
24 static struct xfs_btree_cur *
25 xfs_refcountbt_dup_cursor(
26 	struct xfs_btree_cur	*cur)
27 {
28 	return xfs_refcountbt_init_cursor(cur->bc_mp, cur->bc_tp,
29 			cur->bc_ag.agbp, cur->bc_ag.pag);
30 }
31 
32 STATIC void
33 xfs_refcountbt_set_root(
34 	struct xfs_btree_cur		*cur,
35 	const union xfs_btree_ptr	*ptr,
36 	int				inc)
37 {
38 	struct xfs_buf		*agbp = cur->bc_ag.agbp;
39 	struct xfs_agf		*agf = agbp->b_addr;
40 	struct xfs_perag	*pag = agbp->b_pag;
41 
42 	ASSERT(ptr->s != 0);
43 
44 	agf->agf_refcount_root = ptr->s;
45 	be32_add_cpu(&agf->agf_refcount_level, inc);
46 	pag->pagf_refcount_level += inc;
47 
48 	xfs_alloc_log_agf(cur->bc_tp, agbp,
49 			XFS_AGF_REFCOUNT_ROOT | XFS_AGF_REFCOUNT_LEVEL);
50 }
51 
52 STATIC int
53 xfs_refcountbt_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 	struct xfs_buf		*agbp = cur->bc_ag.agbp;
60 	struct xfs_agf		*agf = agbp->b_addr;
61 	struct xfs_alloc_arg	args;		/* block allocation args */
62 	int			error;		/* error return value */
63 
64 	memset(&args, 0, sizeof(args));
65 	args.tp = cur->bc_tp;
66 	args.mp = cur->bc_mp;
67 	args.type = XFS_ALLOCTYPE_NEAR_BNO;
68 	args.fsbno = XFS_AGB_TO_FSB(cur->bc_mp, cur->bc_ag.pag->pag_agno,
69 			xfs_refc_block(args.mp));
70 	args.oinfo = XFS_RMAP_OINFO_REFC;
71 	args.minlen = args.maxlen = args.prod = 1;
72 	args.resv = XFS_AG_RESV_METADATA;
73 
74 	error = xfs_alloc_vextent(&args);
75 	if (error)
76 		goto out_error;
77 	trace_xfs_refcountbt_alloc_block(cur->bc_mp, cur->bc_ag.pag->pag_agno,
78 			args.agbno, 1);
79 	if (args.fsbno == NULLFSBLOCK) {
80 		*stat = 0;
81 		return 0;
82 	}
83 	ASSERT(args.agno == cur->bc_ag.pag->pag_agno);
84 	ASSERT(args.len == 1);
85 
86 	new->s = cpu_to_be32(args.agbno);
87 	be32_add_cpu(&agf->agf_refcount_blocks, 1);
88 	xfs_alloc_log_agf(cur->bc_tp, agbp, XFS_AGF_REFCOUNT_BLOCKS);
89 
90 	*stat = 1;
91 	return 0;
92 
93 out_error:
94 	return error;
95 }
96 
97 STATIC int
98 xfs_refcountbt_free_block(
99 	struct xfs_btree_cur	*cur,
100 	struct xfs_buf		*bp)
101 {
102 	struct xfs_mount	*mp = cur->bc_mp;
103 	struct xfs_buf		*agbp = cur->bc_ag.agbp;
104 	struct xfs_agf		*agf = agbp->b_addr;
105 	xfs_fsblock_t		fsbno = XFS_DADDR_TO_FSB(mp, xfs_buf_daddr(bp));
106 	int			error;
107 
108 	trace_xfs_refcountbt_free_block(cur->bc_mp, cur->bc_ag.pag->pag_agno,
109 			XFS_FSB_TO_AGBNO(cur->bc_mp, fsbno), 1);
110 	be32_add_cpu(&agf->agf_refcount_blocks, -1);
111 	xfs_alloc_log_agf(cur->bc_tp, agbp, XFS_AGF_REFCOUNT_BLOCKS);
112 	error = xfs_free_extent(cur->bc_tp, fsbno, 1, &XFS_RMAP_OINFO_REFC,
113 			XFS_AG_RESV_METADATA);
114 	if (error)
115 		return error;
116 
117 	return error;
118 }
119 
120 STATIC int
121 xfs_refcountbt_get_minrecs(
122 	struct xfs_btree_cur	*cur,
123 	int			level)
124 {
125 	return cur->bc_mp->m_refc_mnr[level != 0];
126 }
127 
128 STATIC int
129 xfs_refcountbt_get_maxrecs(
130 	struct xfs_btree_cur	*cur,
131 	int			level)
132 {
133 	return cur->bc_mp->m_refc_mxr[level != 0];
134 }
135 
136 STATIC void
137 xfs_refcountbt_init_key_from_rec(
138 	union xfs_btree_key		*key,
139 	const union xfs_btree_rec	*rec)
140 {
141 	key->refc.rc_startblock = rec->refc.rc_startblock;
142 }
143 
144 STATIC void
145 xfs_refcountbt_init_high_key_from_rec(
146 	union xfs_btree_key		*key,
147 	const union xfs_btree_rec	*rec)
148 {
149 	__u32				x;
150 
151 	x = be32_to_cpu(rec->refc.rc_startblock);
152 	x += be32_to_cpu(rec->refc.rc_blockcount) - 1;
153 	key->refc.rc_startblock = cpu_to_be32(x);
154 }
155 
156 STATIC void
157 xfs_refcountbt_init_rec_from_cur(
158 	struct xfs_btree_cur	*cur,
159 	union xfs_btree_rec	*rec)
160 {
161 	rec->refc.rc_startblock = cpu_to_be32(cur->bc_rec.rc.rc_startblock);
162 	rec->refc.rc_blockcount = cpu_to_be32(cur->bc_rec.rc.rc_blockcount);
163 	rec->refc.rc_refcount = cpu_to_be32(cur->bc_rec.rc.rc_refcount);
164 }
165 
166 STATIC void
167 xfs_refcountbt_init_ptr_from_cur(
168 	struct xfs_btree_cur	*cur,
169 	union xfs_btree_ptr	*ptr)
170 {
171 	struct xfs_agf		*agf = cur->bc_ag.agbp->b_addr;
172 
173 	ASSERT(cur->bc_ag.pag->pag_agno == be32_to_cpu(agf->agf_seqno));
174 
175 	ptr->s = agf->agf_refcount_root;
176 }
177 
178 STATIC int64_t
179 xfs_refcountbt_key_diff(
180 	struct xfs_btree_cur		*cur,
181 	const union xfs_btree_key	*key)
182 {
183 	struct xfs_refcount_irec	*rec = &cur->bc_rec.rc;
184 	const struct xfs_refcount_key	*kp = &key->refc;
185 
186 	return (int64_t)be32_to_cpu(kp->rc_startblock) - rec->rc_startblock;
187 }
188 
189 STATIC int64_t
190 xfs_refcountbt_diff_two_keys(
191 	struct xfs_btree_cur		*cur,
192 	const union xfs_btree_key	*k1,
193 	const union xfs_btree_key	*k2)
194 {
195 	return (int64_t)be32_to_cpu(k1->refc.rc_startblock) -
196 			  be32_to_cpu(k2->refc.rc_startblock);
197 }
198 
199 STATIC xfs_failaddr_t
200 xfs_refcountbt_verify(
201 	struct xfs_buf		*bp)
202 {
203 	struct xfs_mount	*mp = bp->b_mount;
204 	struct xfs_btree_block	*block = XFS_BUF_TO_BLOCK(bp);
205 	struct xfs_perag	*pag = bp->b_pag;
206 	xfs_failaddr_t		fa;
207 	unsigned int		level;
208 
209 	if (!xfs_verify_magic(bp, block->bb_magic))
210 		return __this_address;
211 
212 	if (!xfs_has_reflink(mp))
213 		return __this_address;
214 	fa = xfs_btree_sblock_v5hdr_verify(bp);
215 	if (fa)
216 		return fa;
217 
218 	level = be16_to_cpu(block->bb_level);
219 	if (pag && pag->pagf_init) {
220 		if (level >= pag->pagf_refcount_level)
221 			return __this_address;
222 	} else if (level >= mp->m_refc_maxlevels)
223 		return __this_address;
224 
225 	return xfs_btree_sblock_verify(bp, mp->m_refc_mxr[level != 0]);
226 }
227 
228 STATIC void
229 xfs_refcountbt_read_verify(
230 	struct xfs_buf	*bp)
231 {
232 	xfs_failaddr_t	fa;
233 
234 	if (!xfs_btree_sblock_verify_crc(bp))
235 		xfs_verifier_error(bp, -EFSBADCRC, __this_address);
236 	else {
237 		fa = xfs_refcountbt_verify(bp);
238 		if (fa)
239 			xfs_verifier_error(bp, -EFSCORRUPTED, fa);
240 	}
241 
242 	if (bp->b_error)
243 		trace_xfs_btree_corrupt(bp, _RET_IP_);
244 }
245 
246 STATIC void
247 xfs_refcountbt_write_verify(
248 	struct xfs_buf	*bp)
249 {
250 	xfs_failaddr_t	fa;
251 
252 	fa = xfs_refcountbt_verify(bp);
253 	if (fa) {
254 		trace_xfs_btree_corrupt(bp, _RET_IP_);
255 		xfs_verifier_error(bp, -EFSCORRUPTED, fa);
256 		return;
257 	}
258 	xfs_btree_sblock_calc_crc(bp);
259 
260 }
261 
262 const struct xfs_buf_ops xfs_refcountbt_buf_ops = {
263 	.name			= "xfs_refcountbt",
264 	.magic			= { 0, cpu_to_be32(XFS_REFC_CRC_MAGIC) },
265 	.verify_read		= xfs_refcountbt_read_verify,
266 	.verify_write		= xfs_refcountbt_write_verify,
267 	.verify_struct		= xfs_refcountbt_verify,
268 };
269 
270 STATIC int
271 xfs_refcountbt_keys_inorder(
272 	struct xfs_btree_cur		*cur,
273 	const union xfs_btree_key	*k1,
274 	const union xfs_btree_key	*k2)
275 {
276 	return be32_to_cpu(k1->refc.rc_startblock) <
277 	       be32_to_cpu(k2->refc.rc_startblock);
278 }
279 
280 STATIC int
281 xfs_refcountbt_recs_inorder(
282 	struct xfs_btree_cur		*cur,
283 	const union xfs_btree_rec	*r1,
284 	const union xfs_btree_rec	*r2)
285 {
286 	return  be32_to_cpu(r1->refc.rc_startblock) +
287 		be32_to_cpu(r1->refc.rc_blockcount) <=
288 		be32_to_cpu(r2->refc.rc_startblock);
289 }
290 
291 static const struct xfs_btree_ops xfs_refcountbt_ops = {
292 	.rec_len		= sizeof(struct xfs_refcount_rec),
293 	.key_len		= sizeof(struct xfs_refcount_key),
294 
295 	.dup_cursor		= xfs_refcountbt_dup_cursor,
296 	.set_root		= xfs_refcountbt_set_root,
297 	.alloc_block		= xfs_refcountbt_alloc_block,
298 	.free_block		= xfs_refcountbt_free_block,
299 	.get_minrecs		= xfs_refcountbt_get_minrecs,
300 	.get_maxrecs		= xfs_refcountbt_get_maxrecs,
301 	.init_key_from_rec	= xfs_refcountbt_init_key_from_rec,
302 	.init_high_key_from_rec	= xfs_refcountbt_init_high_key_from_rec,
303 	.init_rec_from_cur	= xfs_refcountbt_init_rec_from_cur,
304 	.init_ptr_from_cur	= xfs_refcountbt_init_ptr_from_cur,
305 	.key_diff		= xfs_refcountbt_key_diff,
306 	.buf_ops		= &xfs_refcountbt_buf_ops,
307 	.diff_two_keys		= xfs_refcountbt_diff_two_keys,
308 	.keys_inorder		= xfs_refcountbt_keys_inorder,
309 	.recs_inorder		= xfs_refcountbt_recs_inorder,
310 };
311 
312 /*
313  * Initialize a new refcount btree cursor.
314  */
315 static struct xfs_btree_cur *
316 xfs_refcountbt_init_common(
317 	struct xfs_mount	*mp,
318 	struct xfs_trans	*tp,
319 	struct xfs_perag	*pag)
320 {
321 	struct xfs_btree_cur	*cur;
322 
323 	ASSERT(pag->pag_agno < mp->m_sb.sb_agcount);
324 
325 	cur = kmem_cache_zalloc(xfs_btree_cur_zone, GFP_NOFS | __GFP_NOFAIL);
326 	cur->bc_tp = tp;
327 	cur->bc_mp = mp;
328 	cur->bc_btnum = XFS_BTNUM_REFC;
329 	cur->bc_blocklog = mp->m_sb.sb_blocklog;
330 	cur->bc_statoff = XFS_STATS_CALC_INDEX(xs_refcbt_2);
331 
332 	cur->bc_flags |= XFS_BTREE_CRC_BLOCKS;
333 
334 	/* take a reference for the cursor */
335 	atomic_inc(&pag->pag_ref);
336 	cur->bc_ag.pag = pag;
337 
338 	cur->bc_ag.refc.nr_ops = 0;
339 	cur->bc_ag.refc.shape_changes = 0;
340 	cur->bc_ops = &xfs_refcountbt_ops;
341 	return cur;
342 }
343 
344 /* Create a btree cursor. */
345 struct xfs_btree_cur *
346 xfs_refcountbt_init_cursor(
347 	struct xfs_mount	*mp,
348 	struct xfs_trans	*tp,
349 	struct xfs_buf		*agbp,
350 	struct xfs_perag	*pag)
351 {
352 	struct xfs_agf		*agf = agbp->b_addr;
353 	struct xfs_btree_cur	*cur;
354 
355 	cur = xfs_refcountbt_init_common(mp, tp, pag);
356 	cur->bc_nlevels = be32_to_cpu(agf->agf_refcount_level);
357 	cur->bc_ag.agbp = agbp;
358 	return cur;
359 }
360 
361 /* Create a btree cursor with a fake root for staging. */
362 struct xfs_btree_cur *
363 xfs_refcountbt_stage_cursor(
364 	struct xfs_mount	*mp,
365 	struct xbtree_afakeroot	*afake,
366 	struct xfs_perag	*pag)
367 {
368 	struct xfs_btree_cur	*cur;
369 
370 	cur = xfs_refcountbt_init_common(mp, NULL, pag);
371 	xfs_btree_stage_afakeroot(cur, afake);
372 	return cur;
373 }
374 
375 /*
376  * Swap in the new btree root.  Once we pass this point the newly rebuilt btree
377  * is in place and we have to kill off all the old btree blocks.
378  */
379 void
380 xfs_refcountbt_commit_staged_btree(
381 	struct xfs_btree_cur	*cur,
382 	struct xfs_trans	*tp,
383 	struct xfs_buf		*agbp)
384 {
385 	struct xfs_agf		*agf = agbp->b_addr;
386 	struct xbtree_afakeroot	*afake = cur->bc_ag.afake;
387 
388 	ASSERT(cur->bc_flags & XFS_BTREE_STAGING);
389 
390 	agf->agf_refcount_root = cpu_to_be32(afake->af_root);
391 	agf->agf_refcount_level = cpu_to_be32(afake->af_levels);
392 	agf->agf_refcount_blocks = cpu_to_be32(afake->af_blocks);
393 	xfs_alloc_log_agf(tp, agbp, XFS_AGF_REFCOUNT_BLOCKS |
394 				    XFS_AGF_REFCOUNT_ROOT |
395 				    XFS_AGF_REFCOUNT_LEVEL);
396 	xfs_btree_commit_afakeroot(cur, tp, agbp, &xfs_refcountbt_ops);
397 }
398 
399 /*
400  * Calculate the number of records in a refcount btree block.
401  */
402 int
403 xfs_refcountbt_maxrecs(
404 	int			blocklen,
405 	bool			leaf)
406 {
407 	blocklen -= XFS_REFCOUNT_BLOCK_LEN;
408 
409 	if (leaf)
410 		return blocklen / sizeof(struct xfs_refcount_rec);
411 	return blocklen / (sizeof(struct xfs_refcount_key) +
412 			   sizeof(xfs_refcount_ptr_t));
413 }
414 
415 /* Compute the maximum height of a refcount btree. */
416 void
417 xfs_refcountbt_compute_maxlevels(
418 	struct xfs_mount		*mp)
419 {
420 	mp->m_refc_maxlevels = xfs_btree_compute_maxlevels(
421 			mp->m_refc_mnr, mp->m_sb.sb_agblocks);
422 }
423 
424 /* Calculate the refcount btree size for some records. */
425 xfs_extlen_t
426 xfs_refcountbt_calc_size(
427 	struct xfs_mount	*mp,
428 	unsigned long long	len)
429 {
430 	return xfs_btree_calc_size(mp->m_refc_mnr, len);
431 }
432 
433 /*
434  * Calculate the maximum refcount btree size.
435  */
436 xfs_extlen_t
437 xfs_refcountbt_max_size(
438 	struct xfs_mount	*mp,
439 	xfs_agblock_t		agblocks)
440 {
441 	/* Bail out if we're uninitialized, which can happen in mkfs. */
442 	if (mp->m_refc_mxr[0] == 0)
443 		return 0;
444 
445 	return xfs_refcountbt_calc_size(mp, agblocks);
446 }
447 
448 /*
449  * Figure out how many blocks to reserve and how many are used by this btree.
450  */
451 int
452 xfs_refcountbt_calc_reserves(
453 	struct xfs_mount	*mp,
454 	struct xfs_trans	*tp,
455 	struct xfs_perag	*pag,
456 	xfs_extlen_t		*ask,
457 	xfs_extlen_t		*used)
458 {
459 	struct xfs_buf		*agbp;
460 	struct xfs_agf		*agf;
461 	xfs_agblock_t		agblocks;
462 	xfs_extlen_t		tree_len;
463 	int			error;
464 
465 	if (!xfs_has_reflink(mp))
466 		return 0;
467 
468 	error = xfs_alloc_read_agf(mp, tp, pag->pag_agno, 0, &agbp);
469 	if (error)
470 		return error;
471 
472 	agf = agbp->b_addr;
473 	agblocks = be32_to_cpu(agf->agf_length);
474 	tree_len = be32_to_cpu(agf->agf_refcount_blocks);
475 	xfs_trans_brelse(tp, agbp);
476 
477 	/*
478 	 * The log is permanently allocated, so the space it occupies will
479 	 * never be available for the kinds of things that would require btree
480 	 * expansion.  We therefore can pretend the space isn't there.
481 	 */
482 	if (mp->m_sb.sb_logstart &&
483 	    XFS_FSB_TO_AGNO(mp, mp->m_sb.sb_logstart) == pag->pag_agno)
484 		agblocks -= mp->m_sb.sb_logblocks;
485 
486 	*ask += xfs_refcountbt_max_size(mp, agblocks);
487 	*used += tree_len;
488 
489 	return error;
490 }
491