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-rw-r--r--fs/bcachefs/str_hash.h319
1 files changed, 319 insertions, 0 deletions
diff --git a/fs/bcachefs/str_hash.h b/fs/bcachefs/str_hash.h
new file mode 100644
index 000000000000..0947fdcdc4cd
--- /dev/null
+++ b/fs/bcachefs/str_hash.h
@@ -0,0 +1,319 @@
+/* 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 "super.h"
+
+#include <linux/crc32c.h>
+#include <crypto/hash.h>
+#include <crypto/sha2.h>
+
+struct bch_hash_info {
+ u8 type;
+ union {
+ __le64 crc_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)
+ };
+
+ switch (info.type) {
+ case BCH_STR_HASH_CRC32C:
+ case BCH_STR_HASH_CRC64:
+ info.crc_key = bi->bi_hash_seed;
+ break;
+ case BCH_STR_HASH_SIPHASH: {
+ 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));
+ break;
+ }
+ default:
+ BUG();
+ }
+
+ 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->crc_key, sizeof(info->crc_key));
+ break;
+ case BCH_STR_HASH_CRC64:
+ ctx->crc64 = bch2_crc64_update(~0, &info->crc_key, sizeof(info->crc_key));
+ break;
+ 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 = bch2_crc64_update(ctx->crc64, data, len);
+ break;
+ 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:
+ return SipHash24_End(&ctx->siphash) >> 1;
+ default:
+ BUG();
+ }
+}
+
+struct bch_hash_desc {
+ enum btree_id btree_id;
+ u8 key_type;
+ u8 whiteout_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);
+};
+
+static inline struct btree_iter *
+bch2_hash_lookup(struct btree_trans *trans,
+ const struct bch_hash_desc desc,
+ const struct bch_hash_info *info,
+ u64 inode, const void *key,
+ unsigned flags)
+{
+ struct btree_iter *iter;
+ struct bkey_s_c k;
+
+ iter = bch2_trans_get_iter(trans, desc.btree_id,
+ POS(inode, desc.hash_key(info, key)),
+ BTREE_ITER_SLOTS|flags);
+ if (IS_ERR(iter))
+ return iter;
+
+ for_each_btree_key_continue(iter, BTREE_ITER_SLOTS, k) {
+ if (iter->pos.inode != inode)
+ break;
+
+ if (k.k->type == desc.key_type) {
+ if (!desc.cmp_key(k, key))
+ return iter;
+ } else if (k.k->type == desc.whiteout_type) {
+ ;
+ } else {
+ /* hole, not found */
+ break;
+ }
+ }
+
+ return IS_ERR(k.k) ? ERR_CAST(k.k) : ERR_PTR(-ENOENT);
+}
+
+static inline struct btree_iter *
+bch2_hash_hole(struct btree_trans *trans,
+ const struct bch_hash_desc desc,
+ const struct bch_hash_info *info,
+ u64 inode, const void *key)
+{
+ struct btree_iter *iter;
+ struct bkey_s_c k;
+
+ iter = bch2_trans_get_iter(trans, desc.btree_id,
+ POS(inode, desc.hash_key(info, key)),
+ BTREE_ITER_SLOTS|BTREE_ITER_INTENT);
+ if (IS_ERR(iter))
+ return iter;
+
+ for_each_btree_key_continue(iter, BTREE_ITER_SLOTS, k) {
+ if (iter->pos.inode != inode)
+ break;
+
+ if (k.k->type != desc.key_type)
+ return iter;
+ }
+
+ return IS_ERR(k.k) ? ERR_CAST(k.k) : ERR_PTR(-ENOSPC);
+}
+
+static 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;
+
+ iter = bch2_trans_copy_iter(trans, start);
+ if (IS_ERR(iter))
+ return PTR_ERR(iter);
+
+ bch2_btree_iter_next_slot(iter);
+
+ for_each_btree_key_continue(iter, BTREE_ITER_SLOTS, k) {
+ if (k.k->type != desc.key_type &&
+ k.k->type != desc.whiteout_type)
+ return false;
+
+ if (k.k->type == desc.key_type &&
+ desc.hash_bkey(info, k) <= start->pos.offset)
+ return true;
+ }
+ return btree_iter_err(k);
+}
+
+static inline int __bch2_hash_set(struct btree_trans *trans,
+ const struct bch_hash_desc desc,
+ const struct bch_hash_info *info,
+ u64 inode, struct bkey_i *insert, int flags)
+{
+ struct btree_iter *iter, *slot = NULL;
+ struct bkey_s_c k;
+
+ iter = bch2_trans_get_iter(trans, desc.btree_id,
+ POS(inode, desc.hash_bkey(info, bkey_i_to_s_c(insert))),
+ BTREE_ITER_SLOTS|BTREE_ITER_INTENT);
+ if (IS_ERR(iter))
+ return PTR_ERR(iter);
+
+ for_each_btree_key_continue(iter, BTREE_ITER_SLOTS, k) {
+ if (iter->pos.inode != inode)
+ break;
+
+ if (k.k->type == desc.key_type) {
+ if (!desc.cmp_bkey(k, bkey_i_to_s_c(insert)))
+ goto found;
+
+ /* hash collision: */
+ continue;
+ }
+
+ if (!slot &&
+ !(flags & BCH_HASH_SET_MUST_REPLACE)) {
+ slot = bch2_trans_copy_iter(trans, iter);
+ if (IS_ERR(slot))
+ return PTR_ERR(slot);
+ }
+
+ if (k.k->type != desc.whiteout_type)
+ goto not_found;
+ }
+
+ return btree_iter_err(k) ?: -ENOSPC;
+not_found:
+ if (flags & BCH_HASH_SET_MUST_REPLACE)
+ return -ENOENT;
+
+ insert->k.p = slot->pos;
+ bch2_trans_update(trans, slot, insert, 0);
+ return 0;
+found:
+ if (flags & BCH_HASH_SET_MUST_CREATE)
+ return -EEXIST;
+
+ insert->k.p = iter->pos;
+ bch2_trans_update(trans, iter, insert, 0);
+ return 0;
+}
+
+static inline int bch2_hash_set(const struct bch_hash_desc desc,
+ const struct bch_hash_info *info,
+ struct bch_fs *c, u64 inode,
+ u64 *journal_seq,
+ struct bkey_i *insert, int flags)
+{
+ return bch2_trans_do(c, journal_seq, flags|BTREE_INSERT_ATOMIC,
+ __bch2_hash_set(&trans, desc, info,
+ inode, insert, flags));
+}
+
+static 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)
+{
+ struct bkey_i *delete;
+ int ret;
+
+ ret = bch2_hash_needs_whiteout(trans, desc, info, iter);
+ if (ret < 0)
+ return ret;
+
+ delete = bch2_trans_kmalloc(trans, sizeof(*delete));
+ if (IS_ERR(delete))
+ return PTR_ERR(delete);
+
+ bkey_init(&delete->k);
+ delete->k.p = iter->pos;
+ delete->k.type = ret ? desc.whiteout_type : KEY_TYPE_DELETED;
+
+ bch2_trans_update(trans, iter, delete, 0);
+ return 0;
+}
+
+static inline int bch2_hash_delete(struct btree_trans *trans,
+ const struct bch_hash_desc desc,
+ const struct bch_hash_info *info,
+ u64 inode, const void *key)
+{
+ struct btree_iter *iter;
+
+ iter = bch2_hash_lookup(trans, desc, info, inode, key,
+ BTREE_ITER_INTENT);
+ if (IS_ERR(iter))
+ return PTR_ERR(iter);
+
+ return bch2_hash_delete_at(trans, desc, info, iter);
+}
+
+#endif /* _BCACHEFS_STR_HASH_H */
generated by cgit v1.2.3-58-ga151 (git 2.39.0) at 2024-11-25 23:09:53 +0000