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Update bcachefs sources to 1210f6c925 bcachefs: BCH_SB_FEATURES_ALL
[bcachefs-tools-debian] / libbcachefs / str_hash.h
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 "super.h"
12
13 #include <linux/crc32c.h>
14 #include <crypto/hash.h>
15 #include <crypto/sha.h>
16
17 static inline enum bch_str_hash_type
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         u8                      type;
36         union {
37                 __le64          crc_key;
38                 SIPHASH_KEY     siphash_key;
39         };
40 };
41
42 static inline struct bch_hash_info
43 bch2_hash_info_init(struct bch_fs *c, const struct bch_inode_unpacked *bi)
44 {
45         /* XXX ick */
46         struct bch_hash_info info = {
47                 .type = (bi->bi_flags >> INODE_STR_HASH_OFFSET) &
48                         ~(~0U << INODE_STR_HASH_BITS),
49                 .crc_key = bi->bi_hash_seed,
50         };
51
52         if (unlikely(info.type == BCH_STR_HASH_SIPHASH_OLD)) {
53                 SHASH_DESC_ON_STACK(desc, c->sha256);
54                 u8 digest[SHA256_DIGEST_SIZE];
55
56                 desc->tfm = c->sha256;
57
58                 crypto_shash_digest(desc, (void *) &bi->bi_hash_seed,
59                                     sizeof(bi->bi_hash_seed), digest);
60                 memcpy(&info.siphash_key, digest, sizeof(info.siphash_key));
61         }
62
63         return info;
64 }
65
66 struct bch_str_hash_ctx {
67         union {
68                 u32             crc32c;
69                 u64             crc64;
70                 SIPHASH_CTX     siphash;
71         };
72 };
73
74 static inline void bch2_str_hash_init(struct bch_str_hash_ctx *ctx,
75                                      const struct bch_hash_info *info)
76 {
77         switch (info->type) {
78         case BCH_STR_HASH_CRC32C:
79                 ctx->crc32c = crc32c(~0, &info->crc_key, sizeof(info->crc_key));
80                 break;
81         case BCH_STR_HASH_CRC64:
82                 ctx->crc64 = crc64_be(~0, &info->crc_key, sizeof(info->crc_key));
83                 break;
84         case BCH_STR_HASH_SIPHASH_OLD:
85         case BCH_STR_HASH_SIPHASH:
86                 SipHash24_Init(&ctx->siphash, &info->siphash_key);
87                 break;
88         default:
89                 BUG();
90         }
91 }
92
93 static inline void bch2_str_hash_update(struct bch_str_hash_ctx *ctx,
94                                        const struct bch_hash_info *info,
95                                        const void *data, size_t len)
96 {
97         switch (info->type) {
98         case BCH_STR_HASH_CRC32C:
99                 ctx->crc32c = crc32c(ctx->crc32c, data, len);
100                 break;
101         case BCH_STR_HASH_CRC64:
102                 ctx->crc64 = crc64_be(ctx->crc64, data, len);
103                 break;
104         case BCH_STR_HASH_SIPHASH_OLD:
105         case BCH_STR_HASH_SIPHASH:
106                 SipHash24_Update(&ctx->siphash, data, len);
107                 break;
108         default:
109                 BUG();
110         }
111 }
112
113 static inline u64 bch2_str_hash_end(struct bch_str_hash_ctx *ctx,
114                                    const struct bch_hash_info *info)
115 {
116         switch (info->type) {
117         case BCH_STR_HASH_CRC32C:
118                 return ctx->crc32c;
119         case BCH_STR_HASH_CRC64:
120                 return ctx->crc64 >> 1;
121         case BCH_STR_HASH_SIPHASH_OLD:
122         case BCH_STR_HASH_SIPHASH:
123                 return SipHash24_End(&ctx->siphash) >> 1;
124         default:
125                 BUG();
126         }
127 }
128
129 struct bch_hash_desc {
130         enum btree_id   btree_id;
131         u8              key_type;
132
133         u64             (*hash_key)(const struct bch_hash_info *, const void *);
134         u64             (*hash_bkey)(const struct bch_hash_info *, struct bkey_s_c);
135         bool            (*cmp_key)(struct bkey_s_c, const void *);
136         bool            (*cmp_bkey)(struct bkey_s_c, struct bkey_s_c);
137 };
138
139 static __always_inline struct btree_iter *
140 bch2_hash_lookup(struct btree_trans *trans,
141                  const struct bch_hash_desc desc,
142                  const struct bch_hash_info *info,
143                  u64 inode, const void *key,
144                  unsigned flags)
145 {
146         struct btree_iter *iter;
147         struct bkey_s_c k;
148         int ret;
149
150         for_each_btree_key(trans, iter, desc.btree_id,
151                            POS(inode, desc.hash_key(info, key)),
152                            BTREE_ITER_SLOTS|flags, k, ret) {
153                 if (iter->pos.inode != inode)
154                         break;
155
156                 if (k.k->type == desc.key_type) {
157                         if (!desc.cmp_key(k, key))
158                                 return iter;
159                 } else if (k.k->type == KEY_TYPE_whiteout) {
160                         ;
161                 } else {
162                         /* hole, not found */
163                         break;
164                 }
165         }
166         bch2_trans_iter_put(trans, iter);
167
168         return ERR_PTR(ret ?: -ENOENT);
169 }
170
171 static __always_inline struct btree_iter *
172 bch2_hash_hole(struct btree_trans *trans,
173                const struct bch_hash_desc desc,
174                const struct bch_hash_info *info,
175                u64 inode, const void *key)
176 {
177         struct btree_iter *iter;
178         struct bkey_s_c k;
179         int ret;
180
181         for_each_btree_key(trans, iter, desc.btree_id,
182                            POS(inode, desc.hash_key(info, key)),
183                            BTREE_ITER_SLOTS|BTREE_ITER_INTENT, k, ret) {
184                 if (iter->pos.inode != inode)
185                         break;
186
187                 if (k.k->type != desc.key_type)
188                         return iter;
189         }
190
191         iter->flags |= BTREE_ITER_KEEP_UNTIL_COMMIT;
192         bch2_trans_iter_put(trans, iter);
193
194         return ERR_PTR(ret ?: -ENOSPC);
195 }
196
197 static __always_inline
198 int bch2_hash_needs_whiteout(struct btree_trans *trans,
199                              const struct bch_hash_desc desc,
200                              const struct bch_hash_info *info,
201                              struct btree_iter *start)
202 {
203         struct btree_iter *iter;
204         struct bkey_s_c k;
205         int ret;
206
207         iter = bch2_trans_copy_iter(trans, start);
208         if (IS_ERR(iter))
209                 return PTR_ERR(iter);
210
211         bch2_btree_iter_next_slot(iter);
212
213         for_each_btree_key_continue(iter, BTREE_ITER_SLOTS, k, ret) {
214                 if (k.k->type != desc.key_type &&
215                     k.k->type != KEY_TYPE_whiteout)
216                         break;
217
218                 if (k.k->type == desc.key_type &&
219                     desc.hash_bkey(info, k) <= start->pos.offset) {
220                         iter->flags |= BTREE_ITER_KEEP_UNTIL_COMMIT;
221                         ret = 1;
222                         break;
223                 }
224         }
225
226         bch2_trans_iter_put(trans, iter);
227         return ret;
228 }
229
230 static __always_inline
231 int bch2_hash_set(struct btree_trans *trans,
232                   const struct bch_hash_desc desc,
233                   const struct bch_hash_info *info,
234                   u64 inode, struct bkey_i *insert, int flags)
235 {
236         struct btree_iter *iter, *slot = NULL;
237         struct bkey_s_c k;
238         bool found = false;
239         int ret;
240
241         for_each_btree_key(trans, iter, desc.btree_id,
242                            POS(inode, desc.hash_bkey(info, bkey_i_to_s_c(insert))),
243                            BTREE_ITER_SLOTS|BTREE_ITER_INTENT, k, ret) {
244                 if (iter->pos.inode != inode)
245                         break;
246
247                 if (k.k->type == desc.key_type) {
248                         if (!desc.cmp_bkey(k, bkey_i_to_s_c(insert)))
249                                 goto found;
250
251                         /* hash collision: */
252                         continue;
253                 }
254
255                 if (!slot &&
256                     !(flags & BCH_HASH_SET_MUST_REPLACE)) {
257                         slot = bch2_trans_copy_iter(trans, iter);
258                         if (IS_ERR(slot))
259                                 return PTR_ERR(slot);
260                 }
261
262                 if (k.k->type != KEY_TYPE_whiteout)
263                         goto not_found;
264         }
265
266         if (!ret)
267                 ret = -ENOSPC;
268 out:
269         bch2_trans_iter_put(trans, slot);
270         bch2_trans_iter_put(trans, iter);
271
272         return ret;
273 found:
274         found = true;
275 not_found:
276
277         if (!found && (flags & BCH_HASH_SET_MUST_REPLACE)) {
278                 ret = -ENOENT;
279         } else if (found && (flags & BCH_HASH_SET_MUST_CREATE)) {
280                 ret = -EEXIST;
281         } else {
282                 if (!found && slot)
283                         swap(iter, slot);
284
285                 insert->k.p = iter->pos;
286                 bch2_trans_update(trans, iter, insert, 0);
287         }
288
289         goto out;
290 }
291
292 static __always_inline
293 int bch2_hash_delete_at(struct btree_trans *trans,
294                         const struct bch_hash_desc desc,
295                         const struct bch_hash_info *info,
296                         struct btree_iter *iter)
297 {
298         struct bkey_i *delete;
299         int ret;
300
301         ret = bch2_hash_needs_whiteout(trans, desc, info, iter);
302         if (ret < 0)
303                 return ret;
304
305         delete = bch2_trans_kmalloc(trans, sizeof(*delete));
306         if (IS_ERR(delete))
307                 return PTR_ERR(delete);
308
309         bkey_init(&delete->k);
310         delete->k.p = iter->pos;
311         delete->k.type = ret ? KEY_TYPE_whiteout : KEY_TYPE_deleted;
312
313         bch2_trans_update(trans, iter, delete, 0);
314         return 0;
315 }
316
317 static __always_inline
318 int bch2_hash_delete(struct btree_trans *trans,
319                      const struct bch_hash_desc desc,
320                      const struct bch_hash_info *info,
321                      u64 inode, const void *key)
322 {
323         struct btree_iter *iter;
324         int ret;
325
326         iter = bch2_hash_lookup(trans, desc, info, inode, key,
327                                 BTREE_ITER_INTENT);
328         if (IS_ERR(iter))
329                 return PTR_ERR(iter);
330
331         ret = bch2_hash_delete_at(trans, desc, info, iter);
332         bch2_trans_iter_put(trans, iter);
333         return ret;
334 }
335
336 #endif /* _BCACHEFS_STR_HASH_H */