diff options
Diffstat (limited to 'c_src/libbcachefs/str_hash.h')
-rw-r--r-- | c_src/libbcachefs/str_hash.h | 381 |
1 files changed, 0 insertions, 381 deletions
diff --git a/c_src/libbcachefs/str_hash.h b/c_src/libbcachefs/str_hash.h deleted file mode 100644 index 89fdb7c2..00000000 --- a/c_src/libbcachefs/str_hash.h +++ /dev/null @@ -1,381 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -#ifndef _BCACHEFS_STR_HASH_H -#define _BCACHEFS_STR_HASH_H - -#include "btree_iter.h" -#include "btree_update.h" -#include "checksum.h" -#include "error.h" -#include "inode.h" -#include "siphash.h" -#include "subvolume.h" -#include "super.h" - -#include <linux/crc32c.h> -#include <crypto/hash.h> -#include <crypto/sha2.h> - -typedef unsigned __bitwise bch_str_hash_flags_t; - -enum bch_str_hash_flags { - __BCH_HASH_SET_MUST_CREATE, - __BCH_HASH_SET_MUST_REPLACE, -}; - -#define BCH_HASH_SET_MUST_CREATE (__force bch_str_hash_flags_t) BIT(__BCH_HASH_SET_MUST_CREATE) -#define BCH_HASH_SET_MUST_REPLACE (__force bch_str_hash_flags_t) BIT(__BCH_HASH_SET_MUST_REPLACE) - -static inline enum bch_str_hash_type -bch2_str_hash_opt_to_type(struct bch_fs *c, enum bch_str_hash_opts opt) -{ - switch (opt) { - case BCH_STR_HASH_OPT_crc32c: - return BCH_STR_HASH_crc32c; - case BCH_STR_HASH_OPT_crc64: - return BCH_STR_HASH_crc64; - case BCH_STR_HASH_OPT_siphash: - return c->sb.features & (1ULL << BCH_FEATURE_new_siphash) - ? BCH_STR_HASH_siphash - : BCH_STR_HASH_siphash_old; - default: - BUG(); - } -} - -struct bch_hash_info { - u8 type; - /* - * For crc32 or crc64 string hashes the first key value of - * the siphash_key (k0) is used as the key. - */ - SIPHASH_KEY siphash_key; -}; - -static inline struct bch_hash_info -bch2_hash_info_init(struct bch_fs *c, const struct bch_inode_unpacked *bi) -{ - /* XXX ick */ - struct bch_hash_info info = { - .type = (bi->bi_flags >> INODE_STR_HASH_OFFSET) & - ~(~0U << INODE_STR_HASH_BITS), - .siphash_key = { .k0 = bi->bi_hash_seed } - }; - - if (unlikely(info.type == BCH_STR_HASH_siphash_old)) { - SHASH_DESC_ON_STACK(desc, c->sha256); - u8 digest[SHA256_DIGEST_SIZE]; - - desc->tfm = c->sha256; - - crypto_shash_digest(desc, (void *) &bi->bi_hash_seed, - sizeof(bi->bi_hash_seed), digest); - memcpy(&info.siphash_key, digest, sizeof(info.siphash_key)); - } - - return info; -} - -struct bch_str_hash_ctx { - union { - u32 crc32c; - u64 crc64; - SIPHASH_CTX siphash; - }; -}; - -static inline void bch2_str_hash_init(struct bch_str_hash_ctx *ctx, - const struct bch_hash_info *info) -{ - switch (info->type) { - case BCH_STR_HASH_crc32c: - ctx->crc32c = crc32c(~0, &info->siphash_key.k0, - sizeof(info->siphash_key.k0)); - break; - case BCH_STR_HASH_crc64: - ctx->crc64 = crc64_be(~0, &info->siphash_key.k0, - sizeof(info->siphash_key.k0)); - break; - case BCH_STR_HASH_siphash_old: - case BCH_STR_HASH_siphash: - SipHash24_Init(&ctx->siphash, &info->siphash_key); - break; - default: - BUG(); - } -} - -static inline void bch2_str_hash_update(struct bch_str_hash_ctx *ctx, - const struct bch_hash_info *info, - const void *data, size_t len) -{ - switch (info->type) { - case BCH_STR_HASH_crc32c: - ctx->crc32c = crc32c(ctx->crc32c, data, len); - break; - case BCH_STR_HASH_crc64: - ctx->crc64 = crc64_be(ctx->crc64, data, len); - break; - case BCH_STR_HASH_siphash_old: - case BCH_STR_HASH_siphash: - SipHash24_Update(&ctx->siphash, data, len); - break; - default: - BUG(); - } -} - -static inline u64 bch2_str_hash_end(struct bch_str_hash_ctx *ctx, - const struct bch_hash_info *info) -{ - switch (info->type) { - case BCH_STR_HASH_crc32c: - return ctx->crc32c; - case BCH_STR_HASH_crc64: - return ctx->crc64 >> 1; - case BCH_STR_HASH_siphash_old: - case BCH_STR_HASH_siphash: - return SipHash24_End(&ctx->siphash) >> 1; - default: - BUG(); - } -} - -struct bch_hash_desc { - enum btree_id btree_id; - u8 key_type; - - u64 (*hash_key)(const struct bch_hash_info *, const void *); - u64 (*hash_bkey)(const struct bch_hash_info *, struct bkey_s_c); - bool (*cmp_key)(struct bkey_s_c, const void *); - bool (*cmp_bkey)(struct bkey_s_c, struct bkey_s_c); - bool (*is_visible)(subvol_inum inum, struct bkey_s_c); -}; - -static inline bool is_visible_key(struct bch_hash_desc desc, subvol_inum inum, struct bkey_s_c k) -{ - return k.k->type == desc.key_type && - (!desc.is_visible || - !inum.inum || - desc.is_visible(inum, k)); -} - -static __always_inline int -bch2_hash_lookup(struct btree_trans *trans, - struct btree_iter *iter, - const struct bch_hash_desc desc, - const struct bch_hash_info *info, - subvol_inum inum, const void *key, - unsigned flags) -{ - struct bkey_s_c k; - u32 snapshot; - int ret; - - ret = bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot); - if (ret) - return ret; - - for_each_btree_key_upto_norestart(trans, *iter, desc.btree_id, - SPOS(inum.inum, desc.hash_key(info, key), snapshot), - POS(inum.inum, U64_MAX), - BTREE_ITER_SLOTS|flags, k, ret) { - if (is_visible_key(desc, inum, k)) { - if (!desc.cmp_key(k, key)) - return 0; - } else if (k.k->type == KEY_TYPE_hash_whiteout) { - ; - } else { - /* hole, not found */ - break; - } - } - bch2_trans_iter_exit(trans, iter); - - return ret ?: -BCH_ERR_ENOENT_str_hash_lookup; -} - -static __always_inline int -bch2_hash_hole(struct btree_trans *trans, - struct btree_iter *iter, - const struct bch_hash_desc desc, - const struct bch_hash_info *info, - subvol_inum inum, const void *key) -{ - struct bkey_s_c k; - u32 snapshot; - int ret; - - ret = bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot); - if (ret) - return ret; - - for_each_btree_key_upto_norestart(trans, *iter, desc.btree_id, - SPOS(inum.inum, desc.hash_key(info, key), snapshot), - POS(inum.inum, U64_MAX), - BTREE_ITER_SLOTS|BTREE_ITER_INTENT, k, ret) - if (!is_visible_key(desc, inum, k)) - return 0; - bch2_trans_iter_exit(trans, iter); - - return ret ?: -BCH_ERR_ENOSPC_str_hash_create; -} - -static __always_inline -int bch2_hash_needs_whiteout(struct btree_trans *trans, - const struct bch_hash_desc desc, - const struct bch_hash_info *info, - struct btree_iter *start) -{ - struct btree_iter iter; - struct bkey_s_c k; - int ret; - - bch2_trans_copy_iter(&iter, start); - - bch2_btree_iter_advance(&iter); - - for_each_btree_key_continue_norestart(iter, BTREE_ITER_SLOTS, k, ret) { - if (k.k->type != desc.key_type && - k.k->type != KEY_TYPE_hash_whiteout) - break; - - if (k.k->type == desc.key_type && - desc.hash_bkey(info, k) <= start->pos.offset) { - ret = 1; - break; - } - } - - bch2_trans_iter_exit(trans, &iter); - return ret; -} - -static __always_inline -int bch2_hash_set_snapshot(struct btree_trans *trans, - const struct bch_hash_desc desc, - const struct bch_hash_info *info, - subvol_inum inum, u32 snapshot, - struct bkey_i *insert, - bch_str_hash_flags_t str_hash_flags, - int update_flags) -{ - struct btree_iter iter, slot = { NULL }; - struct bkey_s_c k; - bool found = false; - int ret; - - for_each_btree_key_upto_norestart(trans, iter, desc.btree_id, - SPOS(insert->k.p.inode, - desc.hash_bkey(info, bkey_i_to_s_c(insert)), - snapshot), - POS(insert->k.p.inode, U64_MAX), - BTREE_ITER_SLOTS|BTREE_ITER_INTENT, k, ret) { - if (is_visible_key(desc, inum, k)) { - if (!desc.cmp_bkey(k, bkey_i_to_s_c(insert))) - goto found; - - /* hash collision: */ - continue; - } - - if (!slot.path && - !(str_hash_flags & BCH_HASH_SET_MUST_REPLACE)) - bch2_trans_copy_iter(&slot, &iter); - - if (k.k->type != KEY_TYPE_hash_whiteout) - goto not_found; - } - - if (!ret) - ret = -BCH_ERR_ENOSPC_str_hash_create; -out: - bch2_trans_iter_exit(trans, &slot); - bch2_trans_iter_exit(trans, &iter); - - return ret; -found: - found = true; -not_found: - - if (!found && (str_hash_flags & BCH_HASH_SET_MUST_REPLACE)) { - ret = -BCH_ERR_ENOENT_str_hash_set_must_replace; - } else if (found && (str_hash_flags & BCH_HASH_SET_MUST_CREATE)) { - ret = -EEXIST; - } else { - if (!found && slot.path) - swap(iter, slot); - - insert->k.p = iter.pos; - ret = bch2_trans_update(trans, &iter, insert, update_flags); - } - - goto out; -} - -static __always_inline -int bch2_hash_set(struct btree_trans *trans, - const struct bch_hash_desc desc, - const struct bch_hash_info *info, - subvol_inum inum, - struct bkey_i *insert, - bch_str_hash_flags_t str_hash_flags) -{ - u32 snapshot; - int ret; - - ret = bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot); - if (ret) - return ret; - - insert->k.p.inode = inum.inum; - - return bch2_hash_set_snapshot(trans, desc, info, inum, - snapshot, insert, str_hash_flags, 0); -} - -static __always_inline -int bch2_hash_delete_at(struct btree_trans *trans, - const struct bch_hash_desc desc, - const struct bch_hash_info *info, - struct btree_iter *iter, - unsigned update_flags) -{ - struct bkey_i *delete; - int ret; - - delete = bch2_trans_kmalloc(trans, sizeof(*delete)); - ret = PTR_ERR_OR_ZERO(delete); - if (ret) - return ret; - - ret = bch2_hash_needs_whiteout(trans, desc, info, iter); - if (ret < 0) - return ret; - - bkey_init(&delete->k); - delete->k.p = iter->pos; - delete->k.type = ret ? KEY_TYPE_hash_whiteout : KEY_TYPE_deleted; - - return bch2_trans_update(trans, iter, delete, update_flags); -} - -static __always_inline -int bch2_hash_delete(struct btree_trans *trans, - const struct bch_hash_desc desc, - const struct bch_hash_info *info, - subvol_inum inum, const void *key) -{ - struct btree_iter iter; - int ret; - - ret = bch2_hash_lookup(trans, &iter, desc, info, inum, key, - BTREE_ITER_INTENT); - if (ret) - return ret; - - ret = bch2_hash_delete_at(trans, desc, info, &iter, 0); - bch2_trans_iter_exit(trans, &iter); - return ret; -} - -#endif /* _BCACHEFS_STR_HASH_H */ |