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 return PTR_ERR(iter);
211 bch2_btree_iter_next_slot(iter);
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)
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;
226 bch2_trans_iter_put(trans, iter);
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)
236 struct btree_iter *iter, *slot = NULL;
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)
247 if (k.k->type == desc.key_type) {
248 if (!desc.cmp_bkey(k, bkey_i_to_s_c(insert)))
251 /* hash collision: */
256 !(flags & BCH_HASH_SET_MUST_REPLACE)) {
257 slot = bch2_trans_copy_iter(trans, iter);
259 return PTR_ERR(slot);
262 if (k.k->type != KEY_TYPE_whiteout)
269 bch2_trans_iter_put(trans, slot);
270 bch2_trans_iter_put(trans, iter);
277 if (!found && (flags & BCH_HASH_SET_MUST_REPLACE)) {
279 } else if (found && (flags & BCH_HASH_SET_MUST_CREATE)) {
285 insert->k.p = iter->pos;
286 bch2_trans_update(trans, iter, insert, 0);
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)
298 struct bkey_i *delete;
301 ret = bch2_hash_needs_whiteout(trans, desc, info, iter);
305 delete = bch2_trans_kmalloc(trans, sizeof(*delete));
307 return PTR_ERR(delete);
309 bkey_init(&delete->k);
310 delete->k.p = iter->pos;
311 delete->k.type = ret ? KEY_TYPE_whiteout : KEY_TYPE_deleted;
313 bch2_trans_update(trans, iter, delete, 0);
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)
323 struct btree_iter *iter;
326 iter = bch2_hash_lookup(trans, desc, info, inode, key,
329 return PTR_ERR(iter);
331 ret = bch2_hash_delete_at(trans, desc, info, iter);
332 bch2_trans_iter_put(trans, iter);
336 #endif /* _BCACHEFS_STR_HASH_H */