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"
11 #include "subvolume.h"
14 #include <linux/crc32c.h>
15 #include <crypto/hash.h>
16 #include <crypto/sha2.h>
18 static inline enum bch_str_hash_type
19 bch2_str_hash_opt_to_type(struct bch_fs *c, enum bch_str_hash_opts opt)
22 case BCH_STR_HASH_OPT_crc32c:
23 return BCH_STR_HASH_crc32c;
24 case BCH_STR_HASH_OPT_crc64:
25 return BCH_STR_HASH_crc64;
26 case BCH_STR_HASH_OPT_siphash:
27 return c->sb.features & (1ULL << BCH_FEATURE_new_siphash)
28 ? BCH_STR_HASH_siphash
29 : BCH_STR_HASH_siphash_old;
35 struct bch_hash_info {
38 * For crc32 or crc64 string hashes the first key value of
39 * the siphash_key (k0) is used as the key.
41 SIPHASH_KEY siphash_key;
44 static inline struct bch_hash_info
45 bch2_hash_info_init(struct bch_fs *c, const struct bch_inode_unpacked *bi)
48 struct bch_hash_info info = {
49 .type = (bi->bi_flags >> INODE_STR_HASH_OFFSET) &
50 ~(~0U << INODE_STR_HASH_BITS),
51 .siphash_key = { .k0 = bi->bi_hash_seed }
54 if (unlikely(info.type == BCH_STR_HASH_siphash_old)) {
55 SHASH_DESC_ON_STACK(desc, c->sha256);
56 u8 digest[SHA256_DIGEST_SIZE];
58 desc->tfm = c->sha256;
60 crypto_shash_digest(desc, (void *) &bi->bi_hash_seed,
61 sizeof(bi->bi_hash_seed), digest);
62 memcpy(&info.siphash_key, digest, sizeof(info.siphash_key));
68 struct bch_str_hash_ctx {
76 static inline void bch2_str_hash_init(struct bch_str_hash_ctx *ctx,
77 const struct bch_hash_info *info)
80 case BCH_STR_HASH_crc32c:
81 ctx->crc32c = crc32c(~0, &info->siphash_key.k0,
82 sizeof(info->siphash_key.k0));
84 case BCH_STR_HASH_crc64:
85 ctx->crc64 = crc64_be(~0, &info->siphash_key.k0,
86 sizeof(info->siphash_key.k0));
88 case BCH_STR_HASH_siphash_old:
89 case BCH_STR_HASH_siphash:
90 SipHash24_Init(&ctx->siphash, &info->siphash_key);
97 static inline void bch2_str_hash_update(struct bch_str_hash_ctx *ctx,
98 const struct bch_hash_info *info,
99 const void *data, size_t len)
101 switch (info->type) {
102 case BCH_STR_HASH_crc32c:
103 ctx->crc32c = crc32c(ctx->crc32c, data, len);
105 case BCH_STR_HASH_crc64:
106 ctx->crc64 = crc64_be(ctx->crc64, data, len);
108 case BCH_STR_HASH_siphash_old:
109 case BCH_STR_HASH_siphash:
110 SipHash24_Update(&ctx->siphash, data, len);
117 static inline u64 bch2_str_hash_end(struct bch_str_hash_ctx *ctx,
118 const struct bch_hash_info *info)
120 switch (info->type) {
121 case BCH_STR_HASH_crc32c:
123 case BCH_STR_HASH_crc64:
124 return ctx->crc64 >> 1;
125 case BCH_STR_HASH_siphash_old:
126 case BCH_STR_HASH_siphash:
127 return SipHash24_End(&ctx->siphash) >> 1;
133 struct bch_hash_desc {
134 enum btree_id btree_id;
137 u64 (*hash_key)(const struct bch_hash_info *, const void *);
138 u64 (*hash_bkey)(const struct bch_hash_info *, struct bkey_s_c);
139 bool (*cmp_key)(struct bkey_s_c, const void *);
140 bool (*cmp_bkey)(struct bkey_s_c, struct bkey_s_c);
141 bool (*is_visible)(subvol_inum inum, struct bkey_s_c);
144 static inline bool is_visible_key(struct bch_hash_desc desc, subvol_inum inum, struct bkey_s_c k)
146 return k.k->type == desc.key_type &&
149 desc.is_visible(inum, k));
152 static __always_inline int
153 bch2_hash_lookup(struct btree_trans *trans,
154 struct btree_iter *iter,
155 const struct bch_hash_desc desc,
156 const struct bch_hash_info *info,
157 subvol_inum inum, const void *key,
164 ret = bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot);
168 for_each_btree_key_upto_norestart(trans, *iter, desc.btree_id,
169 SPOS(inum.inum, desc.hash_key(info, key), snapshot),
170 POS(inum.inum, U64_MAX),
171 BTREE_ITER_SLOTS|flags, k, ret) {
172 if (is_visible_key(desc, inum, k)) {
173 if (!desc.cmp_key(k, key))
175 } else if (k.k->type == KEY_TYPE_hash_whiteout) {
178 /* hole, not found */
182 bch2_trans_iter_exit(trans, iter);
184 return ret ?: -BCH_ERR_ENOENT_str_hash_lookup;
187 static __always_inline int
188 bch2_hash_hole(struct btree_trans *trans,
189 struct btree_iter *iter,
190 const struct bch_hash_desc desc,
191 const struct bch_hash_info *info,
192 subvol_inum inum, const void *key)
198 ret = bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot);
202 for_each_btree_key_upto_norestart(trans, *iter, desc.btree_id,
203 SPOS(inum.inum, desc.hash_key(info, key), snapshot),
204 POS(inum.inum, U64_MAX),
205 BTREE_ITER_SLOTS|BTREE_ITER_INTENT, k, ret)
206 if (!is_visible_key(desc, inum, k))
208 bch2_trans_iter_exit(trans, iter);
210 return ret ?: -BCH_ERR_ENOSPC_str_hash_create;
213 static __always_inline
214 int bch2_hash_needs_whiteout(struct btree_trans *trans,
215 const struct bch_hash_desc desc,
216 const struct bch_hash_info *info,
217 struct btree_iter *start)
219 struct btree_iter iter;
223 bch2_trans_copy_iter(&iter, start);
225 bch2_btree_iter_advance(&iter);
227 for_each_btree_key_continue_norestart(iter, BTREE_ITER_SLOTS, k, ret) {
228 if (k.k->type != desc.key_type &&
229 k.k->type != KEY_TYPE_hash_whiteout)
232 if (k.k->type == desc.key_type &&
233 desc.hash_bkey(info, k) <= start->pos.offset) {
239 bch2_trans_iter_exit(trans, &iter);
243 static __always_inline
244 int bch2_hash_set_snapshot(struct btree_trans *trans,
245 const struct bch_hash_desc desc,
246 const struct bch_hash_info *info,
247 subvol_inum inum, u32 snapshot,
248 struct bkey_i *insert,
252 struct btree_iter iter, slot = { NULL };
257 for_each_btree_key_upto_norestart(trans, iter, desc.btree_id,
258 SPOS(insert->k.p.inode,
259 desc.hash_bkey(info, bkey_i_to_s_c(insert)),
261 POS(insert->k.p.inode, U64_MAX),
262 BTREE_ITER_SLOTS|BTREE_ITER_INTENT, k, ret) {
263 if (is_visible_key(desc, inum, k)) {
264 if (!desc.cmp_bkey(k, bkey_i_to_s_c(insert)))
267 /* hash collision: */
272 !(flags & BCH_HASH_SET_MUST_REPLACE))
273 bch2_trans_copy_iter(&slot, &iter);
275 if (k.k->type != KEY_TYPE_hash_whiteout)
280 ret = -BCH_ERR_ENOSPC_str_hash_create;
282 bch2_trans_iter_exit(trans, &slot);
283 bch2_trans_iter_exit(trans, &iter);
290 if (!found && (flags & BCH_HASH_SET_MUST_REPLACE)) {
291 ret = -BCH_ERR_ENOENT_str_hash_set_must_replace;
292 } else if (found && (flags & BCH_HASH_SET_MUST_CREATE)) {
295 if (!found && slot.path)
298 insert->k.p = iter.pos;
299 ret = bch2_trans_update(trans, &iter, insert, 0);
305 static __always_inline
306 int bch2_hash_set(struct btree_trans *trans,
307 const struct bch_hash_desc desc,
308 const struct bch_hash_info *info,
310 struct bkey_i *insert, int flags)
315 ret = bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot);
319 insert->k.p.inode = inum.inum;
321 return bch2_hash_set_snapshot(trans, desc, info, inum,
322 snapshot, insert, flags, 0);
325 static __always_inline
326 int bch2_hash_delete_at(struct btree_trans *trans,
327 const struct bch_hash_desc desc,
328 const struct bch_hash_info *info,
329 struct btree_iter *iter,
330 unsigned update_flags)
332 struct bkey_i *delete;
335 delete = bch2_trans_kmalloc(trans, sizeof(*delete));
336 ret = PTR_ERR_OR_ZERO(delete);
340 ret = bch2_hash_needs_whiteout(trans, desc, info, iter);
344 bkey_init(&delete->k);
345 delete->k.p = iter->pos;
346 delete->k.type = ret ? KEY_TYPE_hash_whiteout : KEY_TYPE_deleted;
348 return bch2_trans_update(trans, iter, delete, update_flags);
351 static __always_inline
352 int bch2_hash_delete(struct btree_trans *trans,
353 const struct bch_hash_desc desc,
354 const struct bch_hash_info *info,
355 subvol_inum inum, const void *key)
357 struct btree_iter iter;
360 ret = bch2_hash_lookup(trans, &iter, desc, info, inum, key,
365 ret = bch2_hash_delete_at(trans, desc, info, &iter, 0);
366 bch2_trans_iter_exit(trans, &iter);
370 #endif /* _BCACHEFS_STR_HASH_H */