1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _BCACHEFS_STR_HASH_H
3 #define _BCACHEFS_STR_HASH_H
5 #include "btree_iter.h"
6 #include "btree_update.h"
13 #include <linux/crc32c.h>
14 #include <crypto/hash.h>
15 #include <crypto/sha2.h>
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)
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;
34 struct bch_hash_info {
37 * For crc32 or crc64 string hashes the first key value of
38 * the siphash_key (k0) is used as the key.
40 SIPHASH_KEY siphash_key;
43 static inline struct bch_hash_info
44 bch2_hash_info_init(struct bch_fs *c, const struct bch_inode_unpacked *bi)
47 struct bch_hash_info info = {
48 .type = (bi->bi_flags >> INODE_STR_HASH_OFFSET) &
49 ~(~0U << INODE_STR_HASH_BITS),
50 .siphash_key = { .k0 = bi->bi_hash_seed }
53 if (unlikely(info.type == BCH_STR_HASH_SIPHASH_OLD)) {
54 SHASH_DESC_ON_STACK(desc, c->sha256);
55 u8 digest[SHA256_DIGEST_SIZE];
57 desc->tfm = c->sha256;
59 crypto_shash_digest(desc, (void *) &bi->bi_hash_seed,
60 sizeof(bi->bi_hash_seed), digest);
61 memcpy(&info.siphash_key, digest, sizeof(info.siphash_key));
67 struct bch_str_hash_ctx {
75 static inline void bch2_str_hash_init(struct bch_str_hash_ctx *ctx,
76 const struct bch_hash_info *info)
79 case BCH_STR_HASH_CRC32C:
80 ctx->crc32c = crc32c(~0, &info->siphash_key.k0,
81 sizeof(info->siphash_key.k0));
83 case BCH_STR_HASH_CRC64:
84 ctx->crc64 = crc64_be(~0, &info->siphash_key.k0,
85 sizeof(info->siphash_key.k0));
87 case BCH_STR_HASH_SIPHASH_OLD:
88 case BCH_STR_HASH_SIPHASH:
89 SipHash24_Init(&ctx->siphash, &info->siphash_key);
96 static inline void bch2_str_hash_update(struct bch_str_hash_ctx *ctx,
97 const struct bch_hash_info *info,
98 const void *data, size_t len)
100 switch (info->type) {
101 case BCH_STR_HASH_CRC32C:
102 ctx->crc32c = crc32c(ctx->crc32c, data, len);
104 case BCH_STR_HASH_CRC64:
105 ctx->crc64 = crc64_be(ctx->crc64, data, len);
107 case BCH_STR_HASH_SIPHASH_OLD:
108 case BCH_STR_HASH_SIPHASH:
109 SipHash24_Update(&ctx->siphash, data, len);
116 static inline u64 bch2_str_hash_end(struct bch_str_hash_ctx *ctx,
117 const struct bch_hash_info *info)
119 switch (info->type) {
120 case BCH_STR_HASH_CRC32C:
122 case BCH_STR_HASH_CRC64:
123 return ctx->crc64 >> 1;
124 case BCH_STR_HASH_SIPHASH_OLD:
125 case BCH_STR_HASH_SIPHASH:
126 return SipHash24_End(&ctx->siphash) >> 1;
132 struct bch_hash_desc {
133 enum btree_id btree_id;
136 u64 (*hash_key)(const struct bch_hash_info *, const void *);
137 u64 (*hash_bkey)(const struct bch_hash_info *, struct bkey_s_c);
138 bool (*cmp_key)(struct bkey_s_c, const void *);
139 bool (*cmp_bkey)(struct bkey_s_c, struct bkey_s_c);
142 static __always_inline struct btree_iter *
143 bch2_hash_lookup(struct btree_trans *trans,
144 const struct bch_hash_desc desc,
145 const struct bch_hash_info *info,
146 u64 inode, const void *key,
149 struct btree_iter *iter;
153 for_each_btree_key(trans, iter, desc.btree_id,
154 POS(inode, desc.hash_key(info, key)),
155 BTREE_ITER_SLOTS|flags, k, ret) {
156 if (iter->pos.inode != inode)
159 if (k.k->type == desc.key_type) {
160 if (!desc.cmp_key(k, key))
162 } else if (k.k->type == KEY_TYPE_hash_whiteout) {
165 /* hole, not found */
169 bch2_trans_iter_put(trans, iter);
171 return ERR_PTR(ret ?: -ENOENT);
174 static __always_inline struct btree_iter *
175 bch2_hash_hole(struct btree_trans *trans,
176 const struct bch_hash_desc desc,
177 const struct bch_hash_info *info,
178 u64 inode, const void *key)
180 struct btree_iter *iter;
184 for_each_btree_key(trans, iter, desc.btree_id,
185 POS(inode, desc.hash_key(info, key)),
186 BTREE_ITER_SLOTS|BTREE_ITER_INTENT, k, ret) {
187 if (iter->pos.inode != inode)
190 if (k.k->type != desc.key_type)
194 iter->flags |= BTREE_ITER_KEEP_UNTIL_COMMIT;
195 bch2_trans_iter_put(trans, iter);
197 return ERR_PTR(ret ?: -ENOSPC);
200 static __always_inline
201 int bch2_hash_needs_whiteout(struct btree_trans *trans,
202 const struct bch_hash_desc desc,
203 const struct bch_hash_info *info,
204 struct btree_iter *start)
206 struct btree_iter *iter;
210 iter = bch2_trans_copy_iter(trans, start);
212 bch2_btree_iter_next_slot(iter);
214 for_each_btree_key_continue(iter, BTREE_ITER_SLOTS, k, ret) {
215 if (k.k->type != desc.key_type &&
216 k.k->type != KEY_TYPE_hash_whiteout)
219 if (k.k->type == desc.key_type &&
220 desc.hash_bkey(info, k) <= start->pos.offset) {
221 iter->flags |= BTREE_ITER_KEEP_UNTIL_COMMIT;
227 bch2_trans_iter_put(trans, iter);
231 static __always_inline
232 int bch2_hash_set(struct btree_trans *trans,
233 const struct bch_hash_desc desc,
234 const struct bch_hash_info *info,
235 u64 inode, struct bkey_i *insert, int flags)
237 struct btree_iter *iter, *slot = NULL;
242 for_each_btree_key(trans, iter, desc.btree_id,
243 POS(inode, desc.hash_bkey(info, bkey_i_to_s_c(insert))),
244 BTREE_ITER_SLOTS|BTREE_ITER_INTENT, k, ret) {
245 if (iter->pos.inode != inode)
248 if (k.k->type == desc.key_type) {
249 if (!desc.cmp_bkey(k, bkey_i_to_s_c(insert)))
252 /* hash collision: */
257 !(flags & BCH_HASH_SET_MUST_REPLACE))
258 slot = bch2_trans_copy_iter(trans, iter);
260 if (k.k->type != KEY_TYPE_hash_whiteout)
267 bch2_trans_iter_put(trans, slot);
268 bch2_trans_iter_put(trans, iter);
275 if (!found && (flags & BCH_HASH_SET_MUST_REPLACE)) {
277 } else if (found && (flags & BCH_HASH_SET_MUST_CREATE)) {
283 insert->k.p = iter->pos;
284 ret = bch2_trans_update(trans, iter, insert, 0);
290 static __always_inline
291 int bch2_hash_delete_at(struct btree_trans *trans,
292 const struct bch_hash_desc desc,
293 const struct bch_hash_info *info,
294 struct btree_iter *iter)
296 struct bkey_i *delete;
299 delete = bch2_trans_kmalloc(trans, sizeof(*delete));
300 ret = PTR_ERR_OR_ZERO(delete);
304 ret = bch2_hash_needs_whiteout(trans, desc, info, iter);
308 bkey_init(&delete->k);
309 delete->k.p = iter->pos;
310 delete->k.type = ret ? KEY_TYPE_hash_whiteout : KEY_TYPE_deleted;
312 return bch2_trans_update(trans, iter, delete, 0);
315 static __always_inline
316 int bch2_hash_delete(struct btree_trans *trans,
317 const struct bch_hash_desc desc,
318 const struct bch_hash_info *info,
319 u64 inode, const void *key)
321 struct btree_iter *iter;
324 iter = bch2_hash_lookup(trans, desc, info, inode, key,
327 return PTR_ERR(iter);
329 ret = bch2_hash_delete_at(trans, desc, info, iter);
330 bch2_trans_iter_put(trans, iter);
334 #endif /* _BCACHEFS_STR_HASH_H */