+++ /dev/null
-/* 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 */
projects / bcachefs-tools-debian / blobdiff