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d2fda304bb
Add a new helper, bch2_hash_lookup_in_snapshot(), for when we're not operating in a subvolume and already have a snapshot ID, and then use it in lookup_lostfound() -> __lookup_dirent(). This is a bugfix - lookup_lostfound() doesn't take a subvolume ID, we were passing a nonsense subvolume ID before, and don't have one to pass since we may be operating in an interior snapshot node that doesn't have a subvolume ID. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
390 lines
9.4 KiB
C
390 lines
9.4 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _BCACHEFS_STR_HASH_H
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#define _BCACHEFS_STR_HASH_H
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#include "btree_iter.h"
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#include "btree_update.h"
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#include "checksum.h"
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#include "error.h"
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#include "inode.h"
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#include "siphash.h"
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#include "subvolume.h"
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#include "super.h"
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#include <linux/crc32c.h>
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#include <crypto/hash.h>
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#include <crypto/sha2.h>
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typedef unsigned __bitwise bch_str_hash_flags_t;
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enum bch_str_hash_flags {
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__BCH_HASH_SET_MUST_CREATE,
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__BCH_HASH_SET_MUST_REPLACE,
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};
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#define BCH_HASH_SET_MUST_CREATE (__force bch_str_hash_flags_t) BIT(__BCH_HASH_SET_MUST_CREATE)
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#define BCH_HASH_SET_MUST_REPLACE (__force bch_str_hash_flags_t) BIT(__BCH_HASH_SET_MUST_REPLACE)
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static inline enum bch_str_hash_type
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bch2_str_hash_opt_to_type(struct bch_fs *c, enum bch_str_hash_opts opt)
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{
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switch (opt) {
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case BCH_STR_HASH_OPT_crc32c:
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return BCH_STR_HASH_crc32c;
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case BCH_STR_HASH_OPT_crc64:
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return BCH_STR_HASH_crc64;
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case BCH_STR_HASH_OPT_siphash:
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return c->sb.features & (1ULL << BCH_FEATURE_new_siphash)
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? BCH_STR_HASH_siphash
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: BCH_STR_HASH_siphash_old;
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default:
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BUG();
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}
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}
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struct bch_hash_info {
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u8 type;
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/*
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* For crc32 or crc64 string hashes the first key value of
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* the siphash_key (k0) is used as the key.
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*/
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SIPHASH_KEY siphash_key;
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};
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static inline struct bch_hash_info
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bch2_hash_info_init(struct bch_fs *c, const struct bch_inode_unpacked *bi)
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{
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/* XXX ick */
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struct bch_hash_info info = {
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.type = (bi->bi_flags >> INODE_STR_HASH_OFFSET) &
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~(~0U << INODE_STR_HASH_BITS),
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.siphash_key = { .k0 = bi->bi_hash_seed }
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};
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if (unlikely(info.type == BCH_STR_HASH_siphash_old)) {
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SHASH_DESC_ON_STACK(desc, c->sha256);
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u8 digest[SHA256_DIGEST_SIZE];
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desc->tfm = c->sha256;
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crypto_shash_digest(desc, (void *) &bi->bi_hash_seed,
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sizeof(bi->bi_hash_seed), digest);
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memcpy(&info.siphash_key, digest, sizeof(info.siphash_key));
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}
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return info;
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}
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struct bch_str_hash_ctx {
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union {
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u32 crc32c;
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u64 crc64;
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SIPHASH_CTX siphash;
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};
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};
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static inline void bch2_str_hash_init(struct bch_str_hash_ctx *ctx,
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const struct bch_hash_info *info)
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{
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switch (info->type) {
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case BCH_STR_HASH_crc32c:
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ctx->crc32c = crc32c(~0, &info->siphash_key.k0,
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sizeof(info->siphash_key.k0));
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break;
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case BCH_STR_HASH_crc64:
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ctx->crc64 = crc64_be(~0, &info->siphash_key.k0,
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sizeof(info->siphash_key.k0));
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break;
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case BCH_STR_HASH_siphash_old:
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case BCH_STR_HASH_siphash:
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SipHash24_Init(&ctx->siphash, &info->siphash_key);
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break;
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default:
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BUG();
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}
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}
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static inline void bch2_str_hash_update(struct bch_str_hash_ctx *ctx,
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const struct bch_hash_info *info,
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const void *data, size_t len)
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{
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switch (info->type) {
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case BCH_STR_HASH_crc32c:
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ctx->crc32c = crc32c(ctx->crc32c, data, len);
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break;
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case BCH_STR_HASH_crc64:
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ctx->crc64 = crc64_be(ctx->crc64, data, len);
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break;
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case BCH_STR_HASH_siphash_old:
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case BCH_STR_HASH_siphash:
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SipHash24_Update(&ctx->siphash, data, len);
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break;
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default:
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BUG();
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}
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}
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static inline u64 bch2_str_hash_end(struct bch_str_hash_ctx *ctx,
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const struct bch_hash_info *info)
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{
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switch (info->type) {
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case BCH_STR_HASH_crc32c:
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return ctx->crc32c;
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case BCH_STR_HASH_crc64:
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return ctx->crc64 >> 1;
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case BCH_STR_HASH_siphash_old:
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case BCH_STR_HASH_siphash:
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return SipHash24_End(&ctx->siphash) >> 1;
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default:
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BUG();
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}
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}
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struct bch_hash_desc {
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enum btree_id btree_id;
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u8 key_type;
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u64 (*hash_key)(const struct bch_hash_info *, const void *);
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u64 (*hash_bkey)(const struct bch_hash_info *, struct bkey_s_c);
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bool (*cmp_key)(struct bkey_s_c, const void *);
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bool (*cmp_bkey)(struct bkey_s_c, struct bkey_s_c);
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bool (*is_visible)(subvol_inum inum, struct bkey_s_c);
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};
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static inline bool is_visible_key(struct bch_hash_desc desc, subvol_inum inum, struct bkey_s_c k)
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{
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return k.k->type == desc.key_type &&
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(!desc.is_visible ||
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!inum.inum ||
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desc.is_visible(inum, k));
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}
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static __always_inline int
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bch2_hash_lookup_in_snapshot(struct btree_trans *trans,
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struct btree_iter *iter,
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const struct bch_hash_desc desc,
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const struct bch_hash_info *info,
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subvol_inum inum, const void *key,
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unsigned flags, u32 snapshot)
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{
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struct bkey_s_c k;
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int ret;
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for_each_btree_key_upto_norestart(trans, *iter, desc.btree_id,
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SPOS(inum.inum, desc.hash_key(info, key), snapshot),
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POS(inum.inum, U64_MAX),
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BTREE_ITER_SLOTS|flags, k, ret) {
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if (is_visible_key(desc, inum, k)) {
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if (!desc.cmp_key(k, key))
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return 0;
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} else if (k.k->type == KEY_TYPE_hash_whiteout) {
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;
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} else {
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/* hole, not found */
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break;
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}
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}
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bch2_trans_iter_exit(trans, iter);
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return ret ?: -BCH_ERR_ENOENT_str_hash_lookup;
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}
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static __always_inline int
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bch2_hash_lookup(struct btree_trans *trans,
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struct btree_iter *iter,
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const struct bch_hash_desc desc,
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const struct bch_hash_info *info,
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subvol_inum inum, const void *key,
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unsigned flags)
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{
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u32 snapshot;
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return bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot) ?:
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bch2_hash_lookup_in_snapshot(trans, iter, desc, info, inum, key, flags, snapshot);
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}
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static __always_inline int
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bch2_hash_hole(struct btree_trans *trans,
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struct btree_iter *iter,
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const struct bch_hash_desc desc,
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const struct bch_hash_info *info,
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subvol_inum inum, const void *key)
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{
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struct bkey_s_c k;
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u32 snapshot;
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int ret;
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ret = bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot);
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if (ret)
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return ret;
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for_each_btree_key_upto_norestart(trans, *iter, desc.btree_id,
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SPOS(inum.inum, desc.hash_key(info, key), snapshot),
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POS(inum.inum, U64_MAX),
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BTREE_ITER_SLOTS|BTREE_ITER_INTENT, k, ret)
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if (!is_visible_key(desc, inum, k))
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return 0;
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bch2_trans_iter_exit(trans, iter);
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return ret ?: -BCH_ERR_ENOSPC_str_hash_create;
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}
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static __always_inline
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int bch2_hash_needs_whiteout(struct btree_trans *trans,
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const struct bch_hash_desc desc,
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const struct bch_hash_info *info,
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struct btree_iter *start)
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{
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struct btree_iter iter;
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struct bkey_s_c k;
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int ret;
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bch2_trans_copy_iter(&iter, start);
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bch2_btree_iter_advance(&iter);
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for_each_btree_key_continue_norestart(iter, BTREE_ITER_SLOTS, k, ret) {
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if (k.k->type != desc.key_type &&
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k.k->type != KEY_TYPE_hash_whiteout)
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break;
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if (k.k->type == desc.key_type &&
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desc.hash_bkey(info, k) <= start->pos.offset) {
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ret = 1;
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break;
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}
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}
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bch2_trans_iter_exit(trans, &iter);
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return ret;
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}
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static __always_inline
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int bch2_hash_set_snapshot(struct btree_trans *trans,
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const struct bch_hash_desc desc,
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const struct bch_hash_info *info,
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subvol_inum inum, u32 snapshot,
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struct bkey_i *insert,
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bch_str_hash_flags_t str_hash_flags,
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int update_flags)
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{
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struct btree_iter iter, slot = { NULL };
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struct bkey_s_c k;
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bool found = false;
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int ret;
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for_each_btree_key_upto_norestart(trans, iter, desc.btree_id,
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SPOS(insert->k.p.inode,
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desc.hash_bkey(info, bkey_i_to_s_c(insert)),
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snapshot),
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POS(insert->k.p.inode, U64_MAX),
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BTREE_ITER_SLOTS|BTREE_ITER_INTENT, k, ret) {
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if (is_visible_key(desc, inum, k)) {
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if (!desc.cmp_bkey(k, bkey_i_to_s_c(insert)))
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goto found;
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/* hash collision: */
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continue;
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}
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if (!slot.path &&
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!(str_hash_flags & BCH_HASH_SET_MUST_REPLACE))
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bch2_trans_copy_iter(&slot, &iter);
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if (k.k->type != KEY_TYPE_hash_whiteout)
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goto not_found;
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}
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if (!ret)
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ret = -BCH_ERR_ENOSPC_str_hash_create;
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out:
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bch2_trans_iter_exit(trans, &slot);
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bch2_trans_iter_exit(trans, &iter);
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return ret;
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found:
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found = true;
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not_found:
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if (!found && (str_hash_flags & BCH_HASH_SET_MUST_REPLACE)) {
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ret = -BCH_ERR_ENOENT_str_hash_set_must_replace;
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} else if (found && (str_hash_flags & BCH_HASH_SET_MUST_CREATE)) {
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ret = -EEXIST;
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} else {
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if (!found && slot.path)
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swap(iter, slot);
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insert->k.p = iter.pos;
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ret = bch2_trans_update(trans, &iter, insert, update_flags);
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}
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goto out;
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}
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static __always_inline
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int bch2_hash_set(struct btree_trans *trans,
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const struct bch_hash_desc desc,
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const struct bch_hash_info *info,
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subvol_inum inum,
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struct bkey_i *insert,
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bch_str_hash_flags_t str_hash_flags)
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{
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u32 snapshot;
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int ret;
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ret = bch2_subvolume_get_snapshot(trans, inum.subvol, &snapshot);
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if (ret)
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return ret;
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insert->k.p.inode = inum.inum;
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return bch2_hash_set_snapshot(trans, desc, info, inum,
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snapshot, insert, str_hash_flags, 0);
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}
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static __always_inline
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int bch2_hash_delete_at(struct btree_trans *trans,
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const struct bch_hash_desc desc,
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const struct bch_hash_info *info,
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struct btree_iter *iter,
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unsigned update_flags)
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{
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struct bkey_i *delete;
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int ret;
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delete = bch2_trans_kmalloc(trans, sizeof(*delete));
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ret = PTR_ERR_OR_ZERO(delete);
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if (ret)
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return ret;
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ret = bch2_hash_needs_whiteout(trans, desc, info, iter);
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if (ret < 0)
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return ret;
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bkey_init(&delete->k);
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delete->k.p = iter->pos;
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delete->k.type = ret ? KEY_TYPE_hash_whiteout : KEY_TYPE_deleted;
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return bch2_trans_update(trans, iter, delete, update_flags);
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}
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static __always_inline
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int bch2_hash_delete(struct btree_trans *trans,
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const struct bch_hash_desc desc,
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const struct bch_hash_info *info,
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subvol_inum inum, const void *key)
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{
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struct btree_iter iter;
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int ret;
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ret = bch2_hash_lookup(trans, &iter, desc, info, inum, key,
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BTREE_ITER_INTENT);
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if (ret)
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return ret;
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ret = bch2_hash_delete_at(trans, desc, info, &iter, 0);
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bch2_trans_iter_exit(trans, &iter);
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return ret;
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}
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#endif /* _BCACHEFS_STR_HASH_H */
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