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 */
166 bch2_trans_iter_put(trans, iter);
168 return ERR_PTR(ret ?: -ENOENT);
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)
177 struct btree_iter *iter;
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)
187 if (k.k->type != desc.key_type)
191 iter->flags |= BTREE_ITER_KEEP_UNTIL_COMMIT;
192 bch2_trans_iter_put(trans, iter);
194 return ERR_PTR(ret ?: -ENOSPC);
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)
203 struct btree_iter *iter;
207 iter = bch2_trans_copy_iter(trans, start);
209 bch2_btree_iter_next_slot(iter);
211 for_each_btree_key_continue(iter, BTREE_ITER_SLOTS, k, ret) {
212 if (k.k->type != desc.key_type &&
213 k.k->type != KEY_TYPE_whiteout)
216 if (k.k->type == desc.key_type &&
217 desc.hash_bkey(info, k) <= start->pos.offset) {
218 iter->flags |= BTREE_ITER_KEEP_UNTIL_COMMIT;
224 bch2_trans_iter_put(trans, iter);
228 static __always_inline
229 int bch2_hash_set(struct btree_trans *trans,
230 const struct bch_hash_desc desc,
231 const struct bch_hash_info *info,
232 u64 inode, struct bkey_i *insert, int flags)
234 struct btree_iter *iter, *slot = NULL;
239 for_each_btree_key(trans, iter, desc.btree_id,
240 POS(inode, desc.hash_bkey(info, bkey_i_to_s_c(insert))),
241 BTREE_ITER_SLOTS|BTREE_ITER_INTENT, k, ret) {
242 if (iter->pos.inode != inode)
245 if (k.k->type == desc.key_type) {
246 if (!desc.cmp_bkey(k, bkey_i_to_s_c(insert)))
249 /* hash collision: */
254 !(flags & BCH_HASH_SET_MUST_REPLACE))
255 slot = bch2_trans_copy_iter(trans, iter);
257 if (k.k->type != KEY_TYPE_whiteout)
264 bch2_trans_iter_put(trans, slot);
265 bch2_trans_iter_put(trans, iter);
272 if (!found && (flags & BCH_HASH_SET_MUST_REPLACE)) {
274 } else if (found && (flags & BCH_HASH_SET_MUST_CREATE)) {
280 insert->k.p = iter->pos;
281 bch2_trans_update(trans, iter, insert, 0);
287 static __always_inline
288 int bch2_hash_delete_at(struct btree_trans *trans,
289 const struct bch_hash_desc desc,
290 const struct bch_hash_info *info,
291 struct btree_iter *iter)
293 struct bkey_i *delete;
296 ret = bch2_hash_needs_whiteout(trans, desc, info, iter);
300 delete = bch2_trans_kmalloc(trans, sizeof(*delete));
302 return PTR_ERR(delete);
304 bkey_init(&delete->k);
305 delete->k.p = iter->pos;
306 delete->k.type = ret ? KEY_TYPE_whiteout : KEY_TYPE_deleted;
308 bch2_trans_update(trans, iter, delete, 0);
312 static __always_inline
313 int bch2_hash_delete(struct btree_trans *trans,
314 const struct bch_hash_desc desc,
315 const struct bch_hash_info *info,
316 u64 inode, const void *key)
318 struct btree_iter *iter;
321 iter = bch2_hash_lookup(trans, desc, info, inode, key,
324 return PTR_ERR(iter);
326 ret = bch2_hash_delete_at(trans, desc, info, iter);
327 bch2_trans_iter_put(trans, iter);
331 #endif /* _BCACHEFS_STR_HASH_H */