Merging upstream version 6.7.7.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 370 insertions, 0 deletions

diff --git a/fs/bcachefs/str_hash.h b/fs/bcachefs/str_hash.h
new file mode 100644
index 0000000000..ae21a8cca1
--- /dev/null
+++ b/fs/bcachefs/str_hash.h
@@ -0,0 +1,370 @@
+/* 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>
+
+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,
+			   int 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 &&
+		    !(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 && (flags & BCH_HASH_SET_MUST_REPLACE)) {
+		ret = -BCH_ERR_ENOENT_str_hash_set_must_replace;
+	} else if (found && (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, 0);
+	}
+
+	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, int 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, 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 */