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/sha.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 {
38 SIPHASH_KEY siphash_key;
42 static inline struct bch_hash_info
43 bch2_hash_info_init(struct bch_fs *c, const struct bch_inode_unpacked *bi)
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,
52 if (unlikely(info.type == BCH_STR_HASH_SIPHASH_OLD)) {
53 SHASH_DESC_ON_STACK(desc, c->sha256);
54 u8 digest[SHA256_DIGEST_SIZE];
56 desc->tfm = c->sha256;
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));
66 struct bch_str_hash_ctx {
74 static inline void bch2_str_hash_init(struct bch_str_hash_ctx *ctx,
75 const struct bch_hash_info *info)
78 case BCH_STR_HASH_CRC32C:
79 ctx->crc32c = crc32c(~0, &info->crc_key, sizeof(info->crc_key));
81 case BCH_STR_HASH_CRC64:
82 ctx->crc64 = crc64_be(~0, &info->crc_key, sizeof(info->crc_key));
84 case BCH_STR_HASH_SIPHASH_OLD:
85 case BCH_STR_HASH_SIPHASH:
86 SipHash24_Init(&ctx->siphash, &info->siphash_key);
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)
98 case BCH_STR_HASH_CRC32C:
99 ctx->crc32c = crc32c(ctx->crc32c, data, len);
101 case BCH_STR_HASH_CRC64:
102 ctx->crc64 = crc64_be(ctx->crc64, data, len);
104 case BCH_STR_HASH_SIPHASH_OLD:
105 case BCH_STR_HASH_SIPHASH:
106 SipHash24_Update(&ctx->siphash, data, len);
113 static inline u64 bch2_str_hash_end(struct bch_str_hash_ctx *ctx,
114 const struct bch_hash_info *info)
116 switch (info->type) {
117 case BCH_STR_HASH_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;
129 struct bch_hash_desc {
130 enum btree_id btree_id;
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);
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,
146 struct btree_iter *iter;
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)
156 if (k.k->type == desc.key_type) {
157 if (!desc.cmp_key(k, key))
159 } else if (k.k->type == KEY_TYPE_whiteout) {
162 /* hole, not found */
167 return ERR_PTR(ret ?: -ENOENT);
170 static __always_inline struct btree_iter *
171 bch2_hash_hole(struct btree_trans *trans,
172 const struct bch_hash_desc desc,
173 const struct bch_hash_info *info,
174 u64 inode, const void *key)
176 struct btree_iter *iter;
180 for_each_btree_key(trans, iter, desc.btree_id,
181 POS(inode, desc.hash_key(info, key)),
182 BTREE_ITER_SLOTS|BTREE_ITER_INTENT, k, ret) {
183 if (iter->pos.inode != inode)
186 if (k.k->type != desc.key_type)
190 return ERR_PTR(ret ?: -ENOSPC);
193 static __always_inline
194 int bch2_hash_needs_whiteout(struct btree_trans *trans,
195 const struct bch_hash_desc desc,
196 const struct bch_hash_info *info,
197 struct btree_iter *start)
199 struct btree_iter *iter;
203 iter = bch2_trans_copy_iter(trans, start);
205 return PTR_ERR(iter);
207 bch2_btree_iter_next_slot(iter);
209 for_each_btree_key_continue(iter, BTREE_ITER_SLOTS, k, ret) {
210 if (k.k->type != desc.key_type &&
211 k.k->type != KEY_TYPE_whiteout)
214 if (k.k->type == desc.key_type &&
215 desc.hash_bkey(info, k) <= start->pos.offset) {
216 iter->flags |= BTREE_ITER_KEEP_UNTIL_COMMIT;
222 bch2_trans_iter_put(trans, iter);
226 static __always_inline
227 int bch2_hash_set(struct btree_trans *trans,
228 const struct bch_hash_desc desc,
229 const struct bch_hash_info *info,
230 u64 inode, struct bkey_i *insert, int flags)
232 struct btree_iter *iter, *slot = NULL;
237 for_each_btree_key(trans, iter, desc.btree_id,
238 POS(inode, desc.hash_bkey(info, bkey_i_to_s_c(insert))),
239 BTREE_ITER_SLOTS|BTREE_ITER_INTENT, k, ret) {
240 if (iter->pos.inode != inode)
243 if (k.k->type == desc.key_type) {
244 if (!desc.cmp_bkey(k, bkey_i_to_s_c(insert)))
247 /* hash collision: */
252 !(flags & BCH_HASH_SET_MUST_REPLACE)) {
253 slot = bch2_trans_copy_iter(trans, iter);
255 return PTR_ERR(slot);
258 if (k.k->type != KEY_TYPE_whiteout)
265 if (!IS_ERR_OR_NULL(slot))
266 bch2_trans_iter_put(trans, slot);
267 if (!IS_ERR_OR_NULL(iter))
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 bch2_trans_update(trans, iter, insert);
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 ret = bch2_hash_needs_whiteout(trans, desc, info, iter);
303 delete = bch2_trans_kmalloc(trans, sizeof(*delete));
305 return PTR_ERR(delete);
307 bkey_init(&delete->k);
308 delete->k.p = iter->pos;
309 delete->k.type = ret ? KEY_TYPE_whiteout : KEY_TYPE_deleted;
311 bch2_trans_update(trans, iter, delete);
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;
323 iter = bch2_hash_lookup(trans, desc, info, inode, key,
326 return PTR_ERR(iter);
328 return bch2_hash_delete_at(trans, desc, info, iter);
331 #endif /* _BCACHEFS_STR_HASH_H */