Line data Source code
1 : // SPDX-License-Identifier: GPL-2.0
2 : /*
3 : * Copyright (c) 2014 Red Hat, 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_trans.h"
14 : #include "xfs_alloc.h"
15 : #include "xfs_btree.h"
16 : #include "xfs_btree_staging.h"
17 : #include "xfs_rmap.h"
18 : #include "xfs_rmap_btree.h"
19 : #include "xfs_trace.h"
20 : #include "xfs_error.h"
21 : #include "xfs_extent_busy.h"
22 : #include "xfs_ag.h"
23 : #include "xfs_ag_resv.h"
24 :
25 : static struct kmem_cache *xfs_rmapbt_cur_cache;
26 :
27 : /*
28 : * Reverse map btree.
29 : *
30 : * This is a per-ag tree used to track the owner(s) of a given extent. With
31 : * reflink it is possible for there to be multiple owners, which is a departure
32 : * from classic XFS. Owner records for data extents are inserted when the
33 : * extent is mapped and removed when an extent is unmapped. Owner records for
34 : * all other block types (i.e. metadata) are inserted when an extent is
35 : * allocated and removed when an extent is freed. There can only be one owner
36 : * of a metadata extent, usually an inode or some other metadata structure like
37 : * an AG btree.
38 : *
39 : * The rmap btree is part of the free space management, so blocks for the tree
40 : * are sourced from the agfl. Hence we need transaction reservation support for
41 : * this tree so that the freelist is always large enough. This also impacts on
42 : * the minimum space we need to leave free in the AG.
43 : *
44 : * The tree is ordered by [ag block, owner, offset]. This is a large key size,
45 : * but it is the only way to enforce unique keys when a block can be owned by
46 : * multiple files at any offset. There's no need to order/search by extent
47 : * size for online updating/management of the tree. It is intended that most
48 : * reverse lookups will be to find the owner(s) of a particular block, or to
49 : * try to recover tree and file data from corrupt primary metadata.
50 : */
51 :
52 : static struct xfs_btree_cur *
53 41139506 : xfs_rmapbt_dup_cursor(
54 : struct xfs_btree_cur *cur)
55 : {
56 41139506 : return xfs_rmapbt_init_cursor(cur->bc_mp, cur->bc_tp,
57 : cur->bc_ag.agbp, cur->bc_ag.pag);
58 : }
59 :
60 : STATIC void
61 11828 : xfs_rmapbt_set_root(
62 : struct xfs_btree_cur *cur,
63 : const union xfs_btree_ptr *ptr,
64 : int inc)
65 : {
66 11828 : struct xfs_buf *agbp = cur->bc_ag.agbp;
67 11828 : struct xfs_agf *agf = agbp->b_addr;
68 11828 : int btnum = cur->bc_btnum;
69 :
70 11828 : ASSERT(ptr->s != 0);
71 :
72 11828 : agf->agf_roots[btnum] = ptr->s;
73 11828 : be32_add_cpu(&agf->agf_levels[btnum], inc);
74 11828 : cur->bc_ag.pag->pagf_levels[btnum] += inc;
75 :
76 11828 : xfs_alloc_log_agf(cur->bc_tp, agbp, XFS_AGF_ROOTS | XFS_AGF_LEVELS);
77 11828 : }
78 :
79 : STATIC int
80 297257 : xfs_rmapbt_alloc_block(
81 : struct xfs_btree_cur *cur,
82 : const union xfs_btree_ptr *start,
83 : union xfs_btree_ptr *new,
84 : int *stat)
85 : {
86 297257 : struct xfs_buf *agbp = cur->bc_ag.agbp;
87 297257 : struct xfs_agf *agf = agbp->b_addr;
88 297257 : struct xfs_perag *pag = cur->bc_ag.pag;
89 297257 : int error;
90 297257 : xfs_agblock_t bno;
91 :
92 : /* Allocate the new block from the freelist. If we can't, give up. */
93 297257 : error = xfs_alloc_get_freelist(pag, cur->bc_tp, cur->bc_ag.agbp,
94 : &bno, 1);
95 297257 : if (error)
96 : return error;
97 :
98 297257 : trace_xfs_rmapbt_alloc_block(cur->bc_mp, pag->pag_agno, bno, 1);
99 297257 : if (bno == NULLAGBLOCK) {
100 0 : *stat = 0;
101 0 : return 0;
102 : }
103 :
104 297257 : xfs_extent_busy_reuse(cur->bc_mp, pag, bno, 1, false);
105 :
106 297257 : new->s = cpu_to_be32(bno);
107 297257 : be32_add_cpu(&agf->agf_rmap_blocks, 1);
108 297257 : xfs_alloc_log_agf(cur->bc_tp, agbp, XFS_AGF_RMAP_BLOCKS);
109 :
110 297257 : xfs_ag_resv_rmapbt_alloc(cur->bc_mp, pag->pag_agno);
111 :
112 297257 : *stat = 1;
113 297257 : return 0;
114 : }
115 :
116 : STATIC int
117 121985 : xfs_rmapbt_free_block(
118 : struct xfs_btree_cur *cur,
119 : struct xfs_buf *bp)
120 : {
121 121985 : struct xfs_buf *agbp = cur->bc_ag.agbp;
122 121985 : struct xfs_agf *agf = agbp->b_addr;
123 121985 : struct xfs_perag *pag = cur->bc_ag.pag;
124 121985 : xfs_agblock_t bno;
125 121985 : int error;
126 :
127 121985 : bno = xfs_daddr_to_agbno(cur->bc_mp, xfs_buf_daddr(bp));
128 121985 : trace_xfs_rmapbt_free_block(cur->bc_mp, pag->pag_agno,
129 : bno, 1);
130 121985 : be32_add_cpu(&agf->agf_rmap_blocks, -1);
131 121985 : xfs_alloc_log_agf(cur->bc_tp, agbp, XFS_AGF_RMAP_BLOCKS);
132 121985 : error = xfs_alloc_put_freelist(pag, cur->bc_tp, agbp, NULL, bno, 1);
133 121985 : if (error)
134 : return error;
135 :
136 121985 : xfs_extent_busy_insert(cur->bc_tp, pag, bno, 1,
137 : XFS_EXTENT_BUSY_SKIP_DISCARD);
138 :
139 121985 : xfs_ag_resv_free_extent(pag, XFS_AG_RESV_RMAPBT, NULL, 1);
140 121985 : return 0;
141 : }
142 :
143 : STATIC int
144 94717078 : xfs_rmapbt_get_minrecs(
145 : struct xfs_btree_cur *cur,
146 : int level)
147 : {
148 94717078 : return cur->bc_mp->m_rmap_mnr[level != 0];
149 : }
150 :
151 : STATIC int
152 >12054*10^7 : xfs_rmapbt_get_maxrecs(
153 : struct xfs_btree_cur *cur,
154 : int level)
155 : {
156 >12054*10^7 : return cur->bc_mp->m_rmap_mxr[level != 0];
157 : }
158 :
159 : /*
160 : * Convert the ondisk record's offset field into the ondisk key's offset field.
161 : * Fork and bmbt are significant parts of the rmap record key, but written
162 : * status is merely a record attribute.
163 : */
164 : static inline __be64 ondisk_rec_offset_to_key(const union xfs_btree_rec *rec)
165 : {
166 >19879*10^7 : return rec->rmap.rm_offset & ~cpu_to_be64(XFS_RMAP_OFF_UNWRITTEN);
167 : }
168 :
169 : STATIC void
170 >10606*10^7 : xfs_rmapbt_init_key_from_rec(
171 : union xfs_btree_key *key,
172 : const union xfs_btree_rec *rec)
173 : {
174 >10606*10^7 : key->rmap.rm_startblock = rec->rmap.rm_startblock;
175 >10606*10^7 : key->rmap.rm_owner = rec->rmap.rm_owner;
176 >10606*10^7 : key->rmap.rm_offset = ondisk_rec_offset_to_key(rec);
177 >10606*10^7 : }
178 :
179 : /*
180 : * The high key for a reverse mapping record can be computed by shifting
181 : * the startblock and offset to the highest value that would still map
182 : * to that record. In practice this means that we add blockcount-1 to
183 : * the startblock for all records, and if the record is for a data/attr
184 : * fork mapping, we add blockcount-1 to the offset too.
185 : */
186 : STATIC void
187 92712727659 : xfs_rmapbt_init_high_key_from_rec(
188 : union xfs_btree_key *key,
189 : const union xfs_btree_rec *rec)
190 : {
191 92712727659 : uint64_t off;
192 92712727659 : int adj;
193 :
194 92712727659 : adj = be32_to_cpu(rec->rmap.rm_blockcount) - 1;
195 :
196 92712727659 : key->rmap.rm_startblock = rec->rmap.rm_startblock;
197 92712727659 : be32_add_cpu(&key->rmap.rm_startblock, adj);
198 92737786796 : key->rmap.rm_owner = rec->rmap.rm_owner;
199 92737786796 : key->rmap.rm_offset = ondisk_rec_offset_to_key(rec);
200 92737786796 : if (XFS_RMAP_NON_INODE_OWNER(be64_to_cpu(rec->rmap.rm_owner)) ||
201 87434358101 : XFS_RMAP_IS_BMBT_BLOCK(be64_to_cpu(rec->rmap.rm_offset)))
202 : return;
203 87000753669 : off = be64_to_cpu(key->rmap.rm_offset);
204 87000753669 : off = (XFS_RMAP_OFF(off) + adj) | (off & ~XFS_RMAP_OFF_MASK);
205 87000753669 : key->rmap.rm_offset = cpu_to_be64(off);
206 : }
207 :
208 : STATIC void
209 2085196941 : xfs_rmapbt_init_rec_from_cur(
210 : struct xfs_btree_cur *cur,
211 : union xfs_btree_rec *rec)
212 : {
213 2085196941 : rec->rmap.rm_startblock = cpu_to_be32(cur->bc_rec.r.rm_startblock);
214 2085196941 : rec->rmap.rm_blockcount = cpu_to_be32(cur->bc_rec.r.rm_blockcount);
215 2085196941 : rec->rmap.rm_owner = cpu_to_be64(cur->bc_rec.r.rm_owner);
216 2085196941 : rec->rmap.rm_offset = cpu_to_be64(
217 : xfs_rmap_irec_offset_pack(&cur->bc_rec.r));
218 2085196941 : }
219 :
220 : STATIC void
221 1360408429 : xfs_rmapbt_init_ptr_from_cur(
222 : struct xfs_btree_cur *cur,
223 : union xfs_btree_ptr *ptr)
224 : {
225 1360408429 : struct xfs_agf *agf = cur->bc_ag.agbp->b_addr;
226 :
227 2720816858 : ASSERT(cur->bc_ag.pag->pag_agno == be32_to_cpu(agf->agf_seqno));
228 :
229 1360408429 : ptr->s = agf->agf_roots[cur->bc_btnum];
230 1360415005 : }
231 :
232 : /*
233 : * Mask the appropriate parts of the ondisk key field for a key comparison.
234 : * Fork and bmbt are significant parts of the rmap record key, but written
235 : * status is merely a record attribute.
236 : */
237 : static inline uint64_t offset_keymask(uint64_t offset)
238 : {
239 10746881937 : return offset & ~XFS_RMAP_OFF_UNWRITTEN;
240 : }
241 :
242 : STATIC int64_t
243 8765991123 : xfs_rmapbt_key_diff(
244 : struct xfs_btree_cur *cur,
245 : const union xfs_btree_key *key)
246 : {
247 8765991123 : struct xfs_rmap_irec *rec = &cur->bc_rec.r;
248 8765991123 : const struct xfs_rmap_key *kp = &key->rmap;
249 8765991123 : __u64 x, y;
250 8765991123 : int64_t d;
251 :
252 8765991123 : d = (int64_t)be32_to_cpu(kp->rm_startblock) - rec->rm_startblock;
253 8765991123 : if (d)
254 : return d;
255 :
256 971310671 : x = be64_to_cpu(kp->rm_owner);
257 971310671 : y = rec->rm_owner;
258 971310671 : if (x > y)
259 : return 1;
260 935845672 : else if (y > x)
261 : return -1;
262 :
263 762691461 : x = offset_keymask(be64_to_cpu(kp->rm_offset));
264 762691461 : y = offset_keymask(xfs_rmap_irec_offset_pack(rec));
265 762691461 : if (x > y)
266 : return 1;
267 691349843 : else if (y > x)
268 341026123 : return -1;
269 : return 0;
270 : }
271 :
272 : STATIC int64_t
273 >23922*10^7 : xfs_rmapbt_diff_two_keys(
274 : struct xfs_btree_cur *cur,
275 : const union xfs_btree_key *k1,
276 : const union xfs_btree_key *k2,
277 : const union xfs_btree_key *mask)
278 : {
279 >23922*10^7 : const struct xfs_rmap_key *kp1 = &k1->rmap;
280 >23922*10^7 : const struct xfs_rmap_key *kp2 = &k2->rmap;
281 >23922*10^7 : int64_t d;
282 >23922*10^7 : __u64 x, y;
283 :
284 : /* Doesn't make sense to mask off the physical space part */
285 >23922*10^7 : ASSERT(!mask || mask->rmap.rm_startblock);
286 :
287 >23922*10^7 : d = (int64_t)be32_to_cpu(kp1->rm_startblock) -
288 >23922*10^7 : be32_to_cpu(kp2->rm_startblock);
289 >23922*10^7 : if (d)
290 : return d;
291 :
292 11083434974 : if (!mask || mask->rmap.rm_owner) {
293 11083413545 : x = be64_to_cpu(kp1->rm_owner);
294 11083413545 : y = be64_to_cpu(kp2->rm_owner);
295 11083413545 : if (x > y)
296 : return 1;
297 5473976845 : else if (y > x)
298 : return -1;
299 : }
300 :
301 4979970500 : if (!mask || mask->rmap.rm_offset) {
302 : /* Doesn't make sense to allow offset but not owner */
303 4979973131 : ASSERT(!mask || mask->rmap.rm_owner);
304 :
305 4979973131 : x = offset_keymask(be64_to_cpu(kp1->rm_offset));
306 4979973131 : y = offset_keymask(be64_to_cpu(kp2->rm_offset));
307 4979973131 : if (x > y)
308 : return 1;
309 648417180 : else if (y > x)
310 22463256 : return -1;
311 : }
312 :
313 : return 0;
314 : }
315 :
316 : static xfs_failaddr_t
317 23562210 : xfs_rmapbt_verify(
318 : struct xfs_buf *bp)
319 : {
320 23562210 : struct xfs_mount *mp = bp->b_mount;
321 23562210 : struct xfs_btree_block *block = XFS_BUF_TO_BLOCK(bp);
322 23562210 : struct xfs_perag *pag = bp->b_pag;
323 23562210 : xfs_failaddr_t fa;
324 23562210 : unsigned int level;
325 :
326 : /*
327 : * magic number and level verification
328 : *
329 : * During growfs operations, we can't verify the exact level or owner as
330 : * the perag is not fully initialised and hence not attached to the
331 : * buffer. In this case, check against the maximum tree depth.
332 : *
333 : * Similarly, during log recovery we will have a perag structure
334 : * attached, but the agf information will not yet have been initialised
335 : * from the on disk AGF. Again, we can only check against maximum limits
336 : * in this case.
337 : */
338 23562210 : if (!xfs_verify_magic(bp, block->bb_magic))
339 0 : return __this_address;
340 :
341 23562232 : if (!xfs_has_rmapbt(mp))
342 0 : return __this_address;
343 23562232 : fa = xfs_btree_sblock_v5hdr_verify(bp);
344 23562244 : if (fa)
345 : return fa;
346 :
347 23562225 : level = be16_to_cpu(block->bb_level);
348 47119049 : if (pag && xfs_perag_initialised_agf(pag)) {
349 18546763 : if (level >= pag->pagf_levels[XFS_BTNUM_RMAPi])
350 0 : return __this_address;
351 5015473 : } else if (level >= mp->m_rmap_maxlevels)
352 0 : return __this_address;
353 :
354 23562225 : return xfs_btree_sblock_verify(bp, mp->m_rmap_mxr[level != 0]);
355 : }
356 :
357 : static void
358 1489158 : xfs_rmapbt_read_verify(
359 : struct xfs_buf *bp)
360 : {
361 1489158 : xfs_failaddr_t fa;
362 :
363 1489158 : if (!xfs_btree_sblock_verify_crc(bp))
364 4 : xfs_verifier_error(bp, -EFSBADCRC, __this_address);
365 : else {
366 1489154 : fa = xfs_rmapbt_verify(bp);
367 1489154 : if (fa)
368 0 : xfs_verifier_error(bp, -EFSCORRUPTED, fa);
369 : }
370 :
371 1489158 : if (bp->b_error)
372 4 : trace_xfs_btree_corrupt(bp, _RET_IP_);
373 1489158 : }
374 :
375 : static void
376 8706716 : xfs_rmapbt_write_verify(
377 : struct xfs_buf *bp)
378 : {
379 8706716 : xfs_failaddr_t fa;
380 :
381 8706716 : fa = xfs_rmapbt_verify(bp);
382 8706716 : if (fa) {
383 0 : trace_xfs_btree_corrupt(bp, _RET_IP_);
384 0 : xfs_verifier_error(bp, -EFSCORRUPTED, fa);
385 0 : return;
386 : }
387 8706716 : xfs_btree_sblock_calc_crc(bp);
388 :
389 : }
390 :
391 : const struct xfs_buf_ops xfs_rmapbt_buf_ops = {
392 : .name = "xfs_rmapbt",
393 : .magic = { 0, cpu_to_be32(XFS_RMAP_CRC_MAGIC) },
394 : .verify_read = xfs_rmapbt_read_verify,
395 : .verify_write = xfs_rmapbt_write_verify,
396 : .verify_struct = xfs_rmapbt_verify,
397 : };
398 :
399 : STATIC int
400 4770959 : xfs_rmapbt_keys_inorder(
401 : struct xfs_btree_cur *cur,
402 : const union xfs_btree_key *k1,
403 : const union xfs_btree_key *k2)
404 : {
405 4770959 : uint32_t x;
406 4770959 : uint32_t y;
407 4770959 : uint64_t a;
408 4770959 : uint64_t b;
409 :
410 4770959 : x = be32_to_cpu(k1->rmap.rm_startblock);
411 4770959 : y = be32_to_cpu(k2->rmap.rm_startblock);
412 4770959 : if (x < y)
413 : return 1;
414 56513 : else if (x > y)
415 : return 0;
416 56513 : a = be64_to_cpu(k1->rmap.rm_owner);
417 56513 : b = be64_to_cpu(k2->rmap.rm_owner);
418 56513 : if (a < b)
419 : return 1;
420 52947 : else if (a > b)
421 : return 0;
422 52947 : a = offset_keymask(be64_to_cpu(k1->rmap.rm_offset));
423 52947 : b = offset_keymask(be64_to_cpu(k2->rmap.rm_offset));
424 52947 : if (a <= b)
425 52947 : return 1;
426 : return 0;
427 : }
428 :
429 : STATIC int
430 822885236 : xfs_rmapbt_recs_inorder(
431 : struct xfs_btree_cur *cur,
432 : const union xfs_btree_rec *r1,
433 : const union xfs_btree_rec *r2)
434 : {
435 822885236 : uint32_t x;
436 822885236 : uint32_t y;
437 822885236 : uint64_t a;
438 822885236 : uint64_t b;
439 :
440 822885236 : x = be32_to_cpu(r1->rmap.rm_startblock);
441 822885236 : y = be32_to_cpu(r2->rmap.rm_startblock);
442 822885236 : if (x < y)
443 : return 1;
444 38828836 : else if (x > y)
445 : return 0;
446 38828836 : a = be64_to_cpu(r1->rmap.rm_owner);
447 38828836 : b = be64_to_cpu(r2->rmap.rm_owner);
448 38828836 : if (a < b)
449 : return 1;
450 12069160 : else if (a > b)
451 : return 0;
452 12069160 : a = offset_keymask(be64_to_cpu(r1->rmap.rm_offset));
453 12069160 : b = offset_keymask(be64_to_cpu(r2->rmap.rm_offset));
454 12069160 : if (a <= b)
455 12069160 : return 1;
456 : return 0;
457 : }
458 :
459 : STATIC enum xbtree_key_contig
460 0 : xfs_rmapbt_keys_contiguous(
461 : struct xfs_btree_cur *cur,
462 : const union xfs_btree_key *key1,
463 : const union xfs_btree_key *key2,
464 : const union xfs_btree_key *mask)
465 : {
466 0 : ASSERT(!mask || mask->rmap.rm_startblock);
467 :
468 : /*
469 : * We only support checking contiguity of the physical space component.
470 : * If any callers ever need more specificity than that, they'll have to
471 : * implement it here.
472 : */
473 0 : ASSERT(!mask || (!mask->rmap.rm_owner && !mask->rmap.rm_offset));
474 :
475 0 : return xbtree_key_contig(be32_to_cpu(key1->rmap.rm_startblock),
476 0 : be32_to_cpu(key2->rmap.rm_startblock));
477 : }
478 :
479 : static const struct xfs_btree_ops xfs_rmapbt_ops = {
480 : .rec_len = sizeof(struct xfs_rmap_rec),
481 : .key_len = 2 * sizeof(struct xfs_rmap_key),
482 :
483 : .dup_cursor = xfs_rmapbt_dup_cursor,
484 : .set_root = xfs_rmapbt_set_root,
485 : .alloc_block = xfs_rmapbt_alloc_block,
486 : .free_block = xfs_rmapbt_free_block,
487 : .get_minrecs = xfs_rmapbt_get_minrecs,
488 : .get_maxrecs = xfs_rmapbt_get_maxrecs,
489 : .init_key_from_rec = xfs_rmapbt_init_key_from_rec,
490 : .init_high_key_from_rec = xfs_rmapbt_init_high_key_from_rec,
491 : .init_rec_from_cur = xfs_rmapbt_init_rec_from_cur,
492 : .init_ptr_from_cur = xfs_rmapbt_init_ptr_from_cur,
493 : .key_diff = xfs_rmapbt_key_diff,
494 : .buf_ops = &xfs_rmapbt_buf_ops,
495 : .diff_two_keys = xfs_rmapbt_diff_two_keys,
496 : .keys_inorder = xfs_rmapbt_keys_inorder,
497 : .recs_inorder = xfs_rmapbt_recs_inorder,
498 : .keys_contiguous = xfs_rmapbt_keys_contiguous,
499 : };
500 :
501 : static struct xfs_btree_cur *
502 566155149 : xfs_rmapbt_init_common(
503 : struct xfs_mount *mp,
504 : struct xfs_trans *tp,
505 : struct xfs_perag *pag)
506 : {
507 566155149 : struct xfs_btree_cur *cur;
508 :
509 : /* Overlapping btree; 2 keys per pointer. */
510 566155149 : cur = xfs_btree_alloc_cursor(mp, tp, XFS_BTNUM_RMAP,
511 566155149 : mp->m_rmap_maxlevels, xfs_rmapbt_cur_cache);
512 566160647 : cur->bc_flags = XFS_BTREE_CRC_BLOCKS | XFS_BTREE_OVERLAPPING;
513 566160647 : cur->bc_statoff = XFS_STATS_CALC_INDEX(xs_rmap_2);
514 566160647 : cur->bc_ops = &xfs_rmapbt_ops;
515 :
516 566160647 : cur->bc_ag.pag = xfs_perag_hold(pag);
517 566156772 : return cur;
518 : }
519 :
520 : /* Create a new reverse mapping btree cursor. */
521 : struct xfs_btree_cur *
522 566148734 : xfs_rmapbt_init_cursor(
523 : struct xfs_mount *mp,
524 : struct xfs_trans *tp,
525 : struct xfs_buf *agbp,
526 : struct xfs_perag *pag)
527 : {
528 566148734 : struct xfs_agf *agf = agbp->b_addr;
529 566148734 : struct xfs_btree_cur *cur;
530 :
531 566148734 : cur = xfs_rmapbt_init_common(mp, tp, pag);
532 566151564 : cur->bc_nlevels = be32_to_cpu(agf->agf_levels[XFS_BTNUM_RMAP]);
533 566151564 : cur->bc_ag.agbp = agbp;
534 566151564 : return cur;
535 : }
536 :
537 : /* Create a new reverse mapping btree cursor with a fake root for staging. */
538 : struct xfs_btree_cur *
539 0 : xfs_rmapbt_stage_cursor(
540 : struct xfs_mount *mp,
541 : struct xbtree_afakeroot *afake,
542 : struct xfs_perag *pag)
543 : {
544 0 : struct xfs_btree_cur *cur;
545 :
546 0 : cur = xfs_rmapbt_init_common(mp, NULL, pag);
547 0 : xfs_btree_stage_afakeroot(cur, afake);
548 0 : return cur;
549 : }
550 :
551 : /*
552 : * Install a new reverse mapping btree root. Caller is responsible for
553 : * invalidating and freeing the old btree blocks.
554 : */
555 : void
556 0 : xfs_rmapbt_commit_staged_btree(
557 : struct xfs_btree_cur *cur,
558 : struct xfs_trans *tp,
559 : struct xfs_buf *agbp)
560 : {
561 0 : struct xfs_agf *agf = agbp->b_addr;
562 0 : struct xbtree_afakeroot *afake = cur->bc_ag.afake;
563 :
564 0 : ASSERT(cur->bc_flags & XFS_BTREE_STAGING);
565 :
566 0 : agf->agf_roots[cur->bc_btnum] = cpu_to_be32(afake->af_root);
567 0 : agf->agf_levels[cur->bc_btnum] = cpu_to_be32(afake->af_levels);
568 0 : agf->agf_rmap_blocks = cpu_to_be32(afake->af_blocks);
569 0 : xfs_alloc_log_agf(tp, agbp, XFS_AGF_ROOTS | XFS_AGF_LEVELS |
570 : XFS_AGF_RMAP_BLOCKS);
571 0 : xfs_btree_commit_afakeroot(cur, tp, agbp, &xfs_rmapbt_ops);
572 0 : }
573 :
574 : /* Calculate number of records in a reverse mapping btree block. */
575 : static inline unsigned int
576 : xfs_rmapbt_block_maxrecs(
577 : unsigned int blocklen,
578 : bool leaf)
579 : {
580 45002 : if (leaf)
581 22501 : return blocklen / sizeof(struct xfs_rmap_rec);
582 22501 : return blocklen /
583 : (2 * sizeof(struct xfs_rmap_key) + sizeof(xfs_rmap_ptr_t));
584 : }
585 :
586 : /*
587 : * Calculate number of records in an rmap btree block.
588 : */
589 : int
590 45002 : xfs_rmapbt_maxrecs(
591 : int blocklen,
592 : int leaf)
593 : {
594 45002 : blocklen -= XFS_RMAP_BLOCK_LEN;
595 45002 : return xfs_rmapbt_block_maxrecs(blocklen, leaf);
596 : }
597 :
598 : /* Compute the max possible height for reverse mapping btrees. */
599 : unsigned int
600 22280 : xfs_rmapbt_maxlevels_ondisk(void)
601 : {
602 22280 : unsigned int minrecs[2];
603 22280 : unsigned int blocklen;
604 :
605 22280 : blocklen = XFS_MIN_CRC_BLOCKSIZE - XFS_BTREE_SBLOCK_CRC_LEN;
606 :
607 22280 : minrecs[0] = xfs_rmapbt_block_maxrecs(blocklen, true) / 2;
608 22280 : minrecs[1] = xfs_rmapbt_block_maxrecs(blocklen, false) / 2;
609 :
610 : /*
611 : * Compute the asymptotic maxlevels for an rmapbt on any reflink fs.
612 : *
613 : * On a reflink filesystem, each AG block can have up to 2^32 (per the
614 : * refcount record format) owners, which means that theoretically we
615 : * could face up to 2^64 rmap records. However, we're likely to run
616 : * out of blocks in the AG long before that happens, which means that
617 : * we must compute the max height based on what the btree will look
618 : * like if it consumes almost all the blocks in the AG due to maximal
619 : * sharing factor.
620 : */
621 22280 : return xfs_btree_space_to_height(minrecs, XFS_MAX_CRC_AG_BLOCKS);
622 : }
623 :
624 : /* Compute the maximum height of an rmap btree. */
625 : void
626 22495 : xfs_rmapbt_compute_maxlevels(
627 : struct xfs_mount *mp)
628 : {
629 22495 : if (!xfs_has_rmapbt(mp)) {
630 227 : mp->m_rmap_maxlevels = 0;
631 227 : return;
632 : }
633 :
634 22268 : if (xfs_has_reflink(mp)) {
635 : /*
636 : * Compute the asymptotic maxlevels for an rmap btree on a
637 : * filesystem that supports reflink.
638 : *
639 : * On a reflink filesystem, each AG block can have up to 2^32
640 : * (per the refcount record format) owners, which means that
641 : * theoretically we could face up to 2^64 rmap records.
642 : * However, we're likely to run out of blocks in the AG long
643 : * before that happens, which means that we must compute the
644 : * max height based on what the btree will look like if it
645 : * consumes almost all the blocks in the AG due to maximal
646 : * sharing factor.
647 : */
648 22268 : mp->m_rmap_maxlevels = xfs_btree_space_to_height(mp->m_rmap_mnr,
649 22268 : mp->m_sb.sb_agblocks);
650 : } else {
651 : /*
652 : * If there's no block sharing, compute the maximum rmapbt
653 : * height assuming one rmap record per AG block.
654 : */
655 0 : mp->m_rmap_maxlevels = xfs_btree_compute_maxlevels(
656 0 : mp->m_rmap_mnr, mp->m_sb.sb_agblocks);
657 : }
658 22268 : ASSERT(mp->m_rmap_maxlevels <= xfs_rmapbt_maxlevels_ondisk());
659 : }
660 :
661 : /* Calculate the refcount btree size for some records. */
662 : xfs_extlen_t
663 2439453 : xfs_rmapbt_calc_size(
664 : struct xfs_mount *mp,
665 : unsigned long long len)
666 : {
667 2674162 : return xfs_btree_calc_size(mp->m_rmap_mnr, len);
668 : }
669 :
670 : /*
671 : * Calculate the maximum refcount btree size.
672 : */
673 : xfs_extlen_t
674 0 : xfs_rmapbt_max_size(
675 : struct xfs_mount *mp,
676 : xfs_agblock_t agblocks)
677 : {
678 : /* Bail out if we're uninitialized, which can happen in mkfs. */
679 0 : if (mp->m_rmap_mxr[0] == 0)
680 : return 0;
681 :
682 234709 : return xfs_rmapbt_calc_size(mp, agblocks);
683 : }
684 :
685 : /*
686 : * Figure out how many blocks to reserve and how many are used by this btree.
687 : */
688 : int
689 239561 : xfs_rmapbt_calc_reserves(
690 : struct xfs_mount *mp,
691 : struct xfs_trans *tp,
692 : struct xfs_perag *pag,
693 : xfs_extlen_t *ask,
694 : xfs_extlen_t *used)
695 : {
696 239561 : struct xfs_buf *agbp;
697 239561 : struct xfs_agf *agf;
698 239561 : xfs_agblock_t agblocks;
699 239561 : xfs_extlen_t tree_len;
700 239561 : int error;
701 :
702 239561 : if (!xfs_has_rmapbt(mp))
703 : return 0;
704 :
705 234709 : error = xfs_alloc_read_agf(pag, tp, 0, &agbp);
706 234709 : if (error)
707 : return error;
708 :
709 234709 : agf = agbp->b_addr;
710 234709 : agblocks = be32_to_cpu(agf->agf_length);
711 234709 : tree_len = be32_to_cpu(agf->agf_rmap_blocks);
712 234709 : xfs_trans_brelse(tp, agbp);
713 :
714 : /*
715 : * The log is permanently allocated, so the space it occupies will
716 : * never be available for the kinds of things that would require btree
717 : * expansion. We therefore can pretend the space isn't there.
718 : */
719 234709 : if (xfs_ag_contains_log(mp, pag->pag_agno))
720 42735 : agblocks -= mp->m_sb.sb_logblocks;
721 :
722 : /* Reserve 1% of the AG or enough for 1 block per record. */
723 234709 : *ask += max(agblocks / 100, xfs_rmapbt_max_size(mp, agblocks));
724 234709 : *used += tree_len;
725 :
726 234709 : return error;
727 : }
728 :
729 : int __init
730 12 : xfs_rmapbt_init_cur_cache(void)
731 : {
732 12 : xfs_rmapbt_cur_cache = kmem_cache_create("xfs_rmapbt_cur",
733 12 : xfs_btree_cur_sizeof(xfs_rmapbt_maxlevels_ondisk()),
734 : 0, 0, NULL);
735 :
736 12 : if (!xfs_rmapbt_cur_cache)
737 0 : return -ENOMEM;
738 : return 0;
739 : }
740 :
741 : void
742 12 : xfs_rmapbt_destroy_cur_cache(void)
743 : {
744 12 : kmem_cache_destroy(xfs_rmapbt_cur_cache);
745 12 : xfs_rmapbt_cur_cache = NULL;
746 12 : }
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