1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _BCACHEFS_STR_HASH_H
3 #define _BCACHEFS_STR_HASH_H
4
5 #include "btree_iter.h"
6 #include "btree_update.h"
7 #include "checksum.h"
8 #include "error.h"
9 #include "inode.h"
10 #include "siphash.h"
11 #include "subvolume.h"
12 #include "super.h"
13
14 #include <linux/crc32c.h>
15 #include <crypto/sha2.h>
16
17 static inline enum bch_str_hash_type
bch2_str_hash_opt_to_type(struct bch_fs * c,enum bch_str_hash_opts opt)18 bch2_str_hash_opt_to_type(struct bch_fs *c, enum bch_str_hash_opts opt)
19 {
20 switch (opt) {
21 case BCH_STR_HASH_OPT_crc32c:
22 return BCH_STR_HASH_crc32c;
23 case BCH_STR_HASH_OPT_crc64:
24 return BCH_STR_HASH_crc64;
25 case BCH_STR_HASH_OPT_siphash:
26 return c->sb.features & (1ULL << BCH_FEATURE_new_siphash)
27 ? BCH_STR_HASH_siphash
28 : BCH_STR_HASH_siphash_old;
29 default:
30 BUG();
31 }
32 }
33
34 struct bch_hash_info {
35 u32 inum_snapshot;
36 u8 type;
37 struct unicode_map *cf_encoding;
38 /*
39 * For crc32 or crc64 string hashes the first key value of
40 * the siphash_key (k0) is used as the key.
41 */
42 SIPHASH_KEY siphash_key;
43 };
44
45 static inline struct bch_hash_info
bch2_hash_info_init(struct bch_fs * c,const struct bch_inode_unpacked * bi)46 bch2_hash_info_init(struct bch_fs *c, const struct bch_inode_unpacked *bi)
47 {
48 struct bch_hash_info info = {
49 .inum_snapshot = bi->bi_snapshot,
50 .type = INODE_STR_HASH(bi),
51 #ifdef CONFIG_UNICODE
52 .cf_encoding = bch2_inode_casefold(c, bi) ? c->cf_encoding : NULL,
53 #endif
54 .siphash_key = { .k0 = bi->bi_hash_seed }
55 };
56
57 if (unlikely(info.type == BCH_STR_HASH_siphash_old)) {
58 u8 digest[SHA256_DIGEST_SIZE];
59
60 sha256((const u8 *)&bi->bi_hash_seed,
61 sizeof(bi->bi_hash_seed), digest);
62 memcpy(&info.siphash_key, digest, sizeof(info.siphash_key));
63 }
64
65 return info;
66 }
67
68 struct bch_str_hash_ctx {
69 union {
70 u32 crc32c;
71 u64 crc64;
72 SIPHASH_CTX siphash;
73 };
74 };
75
bch2_str_hash_init(struct bch_str_hash_ctx * ctx,const struct bch_hash_info * info)76 static inline void bch2_str_hash_init(struct bch_str_hash_ctx *ctx,
77 const struct bch_hash_info *info)
78 {
79 switch (info->type) {
80 case BCH_STR_HASH_crc32c:
81 ctx->crc32c = crc32c(~0, &info->siphash_key.k0,
82 sizeof(info->siphash_key.k0));
83 break;
84 case BCH_STR_HASH_crc64:
85 ctx->crc64 = crc64_be(~0, &info->siphash_key.k0,
86 sizeof(info->siphash_key.k0));
87 break;
88 case BCH_STR_HASH_siphash_old:
89 case BCH_STR_HASH_siphash:
90 SipHash24_Init(&ctx->siphash, &info->siphash_key);
91 break;
92 default:
93 BUG();
94 }
95 }
96
bch2_str_hash_update(struct bch_str_hash_ctx * ctx,const struct bch_hash_info * info,const void * data,size_t len)97 static inline void bch2_str_hash_update(struct bch_str_hash_ctx *ctx,
98 const struct bch_hash_info *info,
99 const void *data, size_t len)
100 {
101 switch (info->type) {
102 case BCH_STR_HASH_crc32c:
103 ctx->crc32c = crc32c(ctx->crc32c, data, len);
104 break;
105 case BCH_STR_HASH_crc64:
106 ctx->crc64 = crc64_be(ctx->crc64, data, len);
107 break;
108 case BCH_STR_HASH_siphash_old:
109 case BCH_STR_HASH_siphash:
110 SipHash24_Update(&ctx->siphash, data, len);
111 break;
112 default:
113 BUG();
114 }
115 }
116
bch2_str_hash_end(struct bch_str_hash_ctx * ctx,const struct bch_hash_info * info)117 static inline u64 bch2_str_hash_end(struct bch_str_hash_ctx *ctx,
118 const struct bch_hash_info *info)
119 {
120 switch (info->type) {
121 case BCH_STR_HASH_crc32c:
122 return ctx->crc32c;
123 case BCH_STR_HASH_crc64:
124 return ctx->crc64 >> 1;
125 case BCH_STR_HASH_siphash_old:
126 case BCH_STR_HASH_siphash:
127 return SipHash24_End(&ctx->siphash) >> 1;
128 default:
129 BUG();
130 }
131 }
132
133 struct bch_hash_desc {
134 enum btree_id btree_id;
135 u8 key_type;
136
137 u64 (*hash_key)(const struct bch_hash_info *, const void *);
138 u64 (*hash_bkey)(const struct bch_hash_info *, struct bkey_s_c);
139 bool (*cmp_key)(struct bkey_s_c, const void *);
140 bool (*cmp_bkey)(struct bkey_s_c, struct bkey_s_c);
141 bool (*is_visible)(subvol_inum inum, struct bkey_s_c);
142 };
143
is_visible_key(struct bch_hash_desc desc,subvol_inum inum,struct bkey_s_c k)144 static inline bool is_visible_key(struct bch_hash_desc desc, subvol_inum inum, struct bkey_s_c k)
145 {
146 return k.k->type == desc.key_type &&
147 (!desc.is_visible ||
148 !inum.inum ||
149 desc.is_visible(inum, k));
150 }
151
152 static __always_inline struct bkey_s_c
bch2_hash_lookup_in_snapshot(struct btree_trans * trans,struct btree_iter * iter,const struct bch_hash_desc desc,const struct bch_hash_info * info,subvol_inum inum,const void * key,enum btree_iter_update_trigger_flags flags,u32 snapshot)153 bch2_hash_lookup_in_snapshot(struct btree_trans *trans,
154 struct btree_iter *iter,
155 const struct bch_hash_desc desc,
156 const struct bch_hash_info *info,
157 subvol_inum inum, const void *key,
158 enum btree_iter_update_trigger_flags flags,
159 u32 snapshot)
160 {
161 struct bkey_s_c k;
162 int ret;
163
164 for_each_btree_key_max_norestart(trans, *iter, desc.btree_id,
165 SPOS(inum.inum, desc.hash_key(info, key), snapshot),
166 POS(inum.inum, U64_MAX),
167 BTREE_ITER_slots|flags, k, ret) {
168 if (is_visible_key(desc, inum, k)) {
169 if (!desc.cmp_key(k, key))
170 return k;
171 } else if (k.k->type == KEY_TYPE_hash_whiteout) {
172 ;
173 } else {
174 /* hole, not found */
175 break;
176 }
177 }
178 bch2_trans_iter_exit(trans, iter);
179
180 return bkey_s_c_err(ret ?: -BCH_ERR_ENOENT_str_hash_lookup);
181 }
182
183 static __always_inline struct bkey_s_c
bch2_hash_lookup(struct btree_trans * trans,struct btree_iter * iter,const struct bch_hash_desc desc,const struct bch_hash_info * info,subvol_inum inum,const void * key,enum btree_iter_update_trigger_flags flags)184 bch2_hash_lookup(struct btree_trans *trans,
185 struct btree_iter *iter,
186 const struct bch_hash_desc desc,
187 const struct bch_hash_info *info,
188 subvol_inum inum, const void *key,
189 enum btree_iter_update_trigger_flags flags)
190 {
191 u32 snapshot;
192 int ret = bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot);
193 if (ret)
194 return bkey_s_c_err(ret);
195
196 return bch2_hash_lookup_in_snapshot(trans, iter, desc, info, inum, key, flags, snapshot);
197 }
198
199 static __always_inline int
bch2_hash_hole(struct btree_trans * trans,struct btree_iter * iter,const struct bch_hash_desc desc,const struct bch_hash_info * info,subvol_inum inum,const void * key)200 bch2_hash_hole(struct btree_trans *trans,
201 struct btree_iter *iter,
202 const struct bch_hash_desc desc,
203 const struct bch_hash_info *info,
204 subvol_inum inum, const void *key)
205 {
206 struct bkey_s_c k;
207 u32 snapshot;
208 int ret;
209
210 ret = bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot);
211 if (ret)
212 return ret;
213
214 for_each_btree_key_max_norestart(trans, *iter, desc.btree_id,
215 SPOS(inum.inum, desc.hash_key(info, key), snapshot),
216 POS(inum.inum, U64_MAX),
217 BTREE_ITER_slots|BTREE_ITER_intent, k, ret)
218 if (!is_visible_key(desc, inum, k))
219 return 0;
220 bch2_trans_iter_exit(trans, iter);
221
222 return ret ?: -BCH_ERR_ENOSPC_str_hash_create;
223 }
224
225 static __always_inline
bch2_hash_needs_whiteout(struct btree_trans * trans,const struct bch_hash_desc desc,const struct bch_hash_info * info,struct btree_iter * start)226 int bch2_hash_needs_whiteout(struct btree_trans *trans,
227 const struct bch_hash_desc desc,
228 const struct bch_hash_info *info,
229 struct btree_iter *start)
230 {
231 struct btree_iter iter;
232 struct bkey_s_c k;
233 int ret;
234
235 bch2_trans_copy_iter(trans, &iter, start);
236
237 bch2_btree_iter_advance(trans, &iter);
238
239 for_each_btree_key_continue_norestart(trans, iter, BTREE_ITER_slots, k, ret) {
240 if (k.k->type != desc.key_type &&
241 k.k->type != KEY_TYPE_hash_whiteout)
242 break;
243
244 if (k.k->type == desc.key_type &&
245 desc.hash_bkey(info, k) <= start->pos.offset) {
246 ret = 1;
247 break;
248 }
249 }
250
251 bch2_trans_iter_exit(trans, &iter);
252 return ret;
253 }
254
255 static __always_inline
bch2_hash_set_or_get_in_snapshot(struct btree_trans * trans,struct btree_iter * iter,const struct bch_hash_desc desc,const struct bch_hash_info * info,subvol_inum inum,u32 snapshot,struct bkey_i * insert,enum btree_iter_update_trigger_flags flags)256 struct bkey_s_c bch2_hash_set_or_get_in_snapshot(struct btree_trans *trans,
257 struct btree_iter *iter,
258 const struct bch_hash_desc desc,
259 const struct bch_hash_info *info,
260 subvol_inum inum, u32 snapshot,
261 struct bkey_i *insert,
262 enum btree_iter_update_trigger_flags flags)
263 {
264 struct bch_fs *c = trans->c;
265 struct btree_iter slot = {};
266 struct bkey_s_c k;
267 bool found = false;
268 int ret;
269
270 for_each_btree_key_max_norestart(trans, *iter, desc.btree_id,
271 SPOS(insert->k.p.inode,
272 desc.hash_bkey(info, bkey_i_to_s_c(insert)),
273 snapshot),
274 POS(insert->k.p.inode, U64_MAX),
275 BTREE_ITER_slots|BTREE_ITER_intent|flags, k, ret) {
276 if (is_visible_key(desc, inum, k)) {
277 if (!desc.cmp_bkey(k, bkey_i_to_s_c(insert)))
278 goto found;
279
280 /* hash collision: */
281 continue;
282 }
283
284 if (!slot.path && !(flags & STR_HASH_must_replace))
285 bch2_trans_copy_iter(trans, &slot, iter);
286
287 if (k.k->type != KEY_TYPE_hash_whiteout)
288 goto not_found;
289 }
290
291 if (!ret)
292 ret = bch_err_throw(c, ENOSPC_str_hash_create);
293 out:
294 bch2_trans_iter_exit(trans, &slot);
295 bch2_trans_iter_exit(trans, iter);
296 return ret ? bkey_s_c_err(ret) : bkey_s_c_null;
297 found:
298 found = true;
299 not_found:
300 if (found && (flags & STR_HASH_must_create)) {
301 bch2_trans_iter_exit(trans, &slot);
302 return k;
303 } else if (!found && (flags & STR_HASH_must_replace)) {
304 ret = bch_err_throw(c, ENOENT_str_hash_set_must_replace);
305 } else {
306 if (!found && slot.path)
307 swap(*iter, slot);
308
309 insert->k.p = iter->pos;
310 ret = bch2_trans_update(trans, iter, insert, flags);
311 }
312
313 goto out;
314 }
315
316 static __always_inline
bch2_hash_set_in_snapshot(struct btree_trans * trans,const struct bch_hash_desc desc,const struct bch_hash_info * info,subvol_inum inum,u32 snapshot,struct bkey_i * insert,enum btree_iter_update_trigger_flags flags)317 int bch2_hash_set_in_snapshot(struct btree_trans *trans,
318 const struct bch_hash_desc desc,
319 const struct bch_hash_info *info,
320 subvol_inum inum, u32 snapshot,
321 struct bkey_i *insert,
322 enum btree_iter_update_trigger_flags flags)
323 {
324 struct btree_iter iter;
325 struct bkey_s_c k = bch2_hash_set_or_get_in_snapshot(trans, &iter, desc, info, inum,
326 snapshot, insert, flags);
327 int ret = bkey_err(k);
328 if (ret)
329 return ret;
330 if (k.k) {
331 bch2_trans_iter_exit(trans, &iter);
332 return bch_err_throw(trans->c, EEXIST_str_hash_set);
333 }
334
335 return 0;
336 }
337
338 static __always_inline
bch2_hash_set(struct btree_trans * trans,const struct bch_hash_desc desc,const struct bch_hash_info * info,subvol_inum inum,struct bkey_i * insert,enum btree_iter_update_trigger_flags flags)339 int bch2_hash_set(struct btree_trans *trans,
340 const struct bch_hash_desc desc,
341 const struct bch_hash_info *info,
342 subvol_inum inum,
343 struct bkey_i *insert,
344 enum btree_iter_update_trigger_flags flags)
345 {
346 insert->k.p.inode = inum.inum;
347
348 u32 snapshot;
349 return bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot) ?:
350 bch2_hash_set_in_snapshot(trans, desc, info, inum,
351 snapshot, insert, flags);
352 }
353
354 static __always_inline
bch2_hash_delete_at(struct btree_trans * trans,const struct bch_hash_desc desc,const struct bch_hash_info * info,struct btree_iter * iter,enum btree_iter_update_trigger_flags flags)355 int bch2_hash_delete_at(struct btree_trans *trans,
356 const struct bch_hash_desc desc,
357 const struct bch_hash_info *info,
358 struct btree_iter *iter,
359 enum btree_iter_update_trigger_flags flags)
360 {
361 struct bkey_i *delete;
362 int ret;
363
364 delete = bch2_trans_kmalloc(trans, sizeof(*delete));
365 ret = PTR_ERR_OR_ZERO(delete);
366 if (ret)
367 return ret;
368
369 ret = bch2_hash_needs_whiteout(trans, desc, info, iter);
370 if (ret < 0)
371 return ret;
372
373 bkey_init(&delete->k);
374 delete->k.p = iter->pos;
375 delete->k.type = ret ? KEY_TYPE_hash_whiteout : KEY_TYPE_deleted;
376
377 return bch2_trans_update(trans, iter, delete, flags);
378 }
379
380 static __always_inline
bch2_hash_delete(struct btree_trans * trans,const struct bch_hash_desc desc,const struct bch_hash_info * info,subvol_inum inum,const void * key)381 int bch2_hash_delete(struct btree_trans *trans,
382 const struct bch_hash_desc desc,
383 const struct bch_hash_info *info,
384 subvol_inum inum, const void *key)
385 {
386 struct btree_iter iter;
387 struct bkey_s_c k = bch2_hash_lookup(trans, &iter, desc, info, inum, key,
388 BTREE_ITER_intent);
389 int ret = bkey_err(k);
390 if (ret)
391 return ret;
392
393 ret = bch2_hash_delete_at(trans, desc, info, &iter, 0);
394 bch2_trans_iter_exit(trans, &iter);
395 return ret;
396 }
397
398 int bch2_repair_inode_hash_info(struct btree_trans *, struct bch_inode_unpacked *);
399
400 struct snapshots_seen;
401 int bch2_str_hash_repair_key(struct btree_trans *,
402 struct snapshots_seen *,
403 const struct bch_hash_desc *,
404 struct bch_hash_info *,
405 struct btree_iter *, struct bkey_s_c,
406 struct btree_iter *, struct bkey_s_c,
407 bool *);
408
409 int __bch2_str_hash_check_key(struct btree_trans *,
410 struct snapshots_seen *,
411 const struct bch_hash_desc *,
412 struct bch_hash_info *,
413 struct btree_iter *, struct bkey_s_c,
414 bool *);
415
bch2_str_hash_check_key(struct btree_trans * trans,struct snapshots_seen * s,const struct bch_hash_desc * desc,struct bch_hash_info * hash_info,struct btree_iter * k_iter,struct bkey_s_c hash_k,bool * updated_before_k_pos)416 static inline int bch2_str_hash_check_key(struct btree_trans *trans,
417 struct snapshots_seen *s,
418 const struct bch_hash_desc *desc,
419 struct bch_hash_info *hash_info,
420 struct btree_iter *k_iter, struct bkey_s_c hash_k,
421 bool *updated_before_k_pos)
422 {
423 if (hash_k.k->type != desc->key_type)
424 return 0;
425
426 if (likely(desc->hash_bkey(hash_info, hash_k) == hash_k.k->p.offset))
427 return 0;
428
429 return __bch2_str_hash_check_key(trans, s, desc, hash_info, k_iter, hash_k,
430 updated_before_k_pos);
431 }
432
433 #endif /* _BCACHEFS_STR_HASH_H */
434