linux/fs/bcachefs/checksum.h
Kent Overstreet 04c2c34f00 bcachefs: use crc64 from lib/
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:14 -04:00

189 lines
4.8 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _BCACHEFS_CHECKSUM_H
#define _BCACHEFS_CHECKSUM_H
#include "bcachefs.h"
#include "extents_types.h"
#include "super-io.h"
#include <linux/crc64.h>
#include <crypto/chacha.h>
static inline u64 bch2_crc64_update(u64 crc, const void *p, size_t len)
{
return crc64_be(crc, p, len);
}
#define BCH_NONCE_EXTENT cpu_to_le32(1 << 28)
#define BCH_NONCE_BTREE cpu_to_le32(2 << 28)
#define BCH_NONCE_JOURNAL cpu_to_le32(3 << 28)
#define BCH_NONCE_PRIO cpu_to_le32(4 << 28)
#define BCH_NONCE_POLY cpu_to_le32(1 << 31)
struct bch_csum bch2_checksum(struct bch_fs *, unsigned, struct nonce,
const void *, size_t);
/*
* This is used for various on disk data structures - bch_sb, prio_set, bset,
* jset: The checksum is _always_ the first field of these structs
*/
#define csum_vstruct(_c, _type, _nonce, _i) \
({ \
const void *start = ((const void *) (_i)) + sizeof((_i)->csum); \
const void *end = vstruct_end(_i); \
\
bch2_checksum(_c, _type, _nonce, start, end - start); \
})
int bch2_chacha_encrypt_key(struct bch_key *, struct nonce, void *, size_t);
int bch2_request_key(struct bch_sb *, struct bch_key *);
void bch2_encrypt(struct bch_fs *, unsigned, struct nonce,
void *data, size_t);
struct bch_csum bch2_checksum_bio(struct bch_fs *, unsigned,
struct nonce, struct bio *);
int bch2_rechecksum_bio(struct bch_fs *, struct bio *, struct bversion,
struct bch_extent_crc_unpacked,
struct bch_extent_crc_unpacked *,
struct bch_extent_crc_unpacked *,
unsigned, unsigned, unsigned);
void bch2_encrypt_bio(struct bch_fs *, unsigned,
struct nonce, struct bio *);
int bch2_decrypt_sb_key(struct bch_fs *, struct bch_sb_field_crypt *,
struct bch_key *);
int bch2_disable_encryption(struct bch_fs *);
int bch2_enable_encryption(struct bch_fs *, bool);
void bch2_fs_encryption_exit(struct bch_fs *);
int bch2_fs_encryption_init(struct bch_fs *);
static inline enum bch_csum_type bch2_csum_opt_to_type(enum bch_csum_opts type,
bool data)
{
switch (type) {
case BCH_CSUM_OPT_NONE:
return BCH_CSUM_NONE;
case BCH_CSUM_OPT_CRC32C:
return data ? BCH_CSUM_CRC32C : BCH_CSUM_CRC32C_NONZERO;
case BCH_CSUM_OPT_CRC64:
return data ? BCH_CSUM_CRC64 : BCH_CSUM_CRC64_NONZERO;
default:
BUG();
}
}
static inline enum bch_csum_type bch2_data_checksum_type(struct bch_fs *c,
unsigned opt)
{
if (c->sb.encryption_type)
return c->opts.wide_macs
? BCH_CSUM_CHACHA20_POLY1305_128
: BCH_CSUM_CHACHA20_POLY1305_80;
return bch2_csum_opt_to_type(opt, true);
}
static inline enum bch_csum_type bch2_meta_checksum_type(struct bch_fs *c)
{
if (c->sb.encryption_type)
return BCH_CSUM_CHACHA20_POLY1305_128;
return bch2_csum_opt_to_type(c->opts.metadata_checksum, false);
}
static const unsigned bch2_compression_opt_to_type[] = {
#define x(t) [BCH_COMPRESSION_OPT_##t] = BCH_COMPRESSION_##t,
BCH_COMPRESSION_TYPES()
#undef x
};
static inline bool bch2_checksum_type_valid(const struct bch_fs *c,
unsigned type)
{
if (type >= BCH_CSUM_NR)
return false;
if (bch2_csum_type_is_encryption(type) && !c->chacha20)
return false;
return true;
}
/* returns true if not equal */
static inline bool bch2_crc_cmp(struct bch_csum l, struct bch_csum r)
{
/*
* XXX: need some way of preventing the compiler from optimizing this
* into a form that isn't constant time..
*/
return ((l.lo ^ r.lo) | (l.hi ^ r.hi)) != 0;
}
/* for skipping ahead and encrypting/decrypting at an offset: */
static inline struct nonce nonce_add(struct nonce nonce, unsigned offset)
{
EBUG_ON(offset & (CHACHA_BLOCK_SIZE - 1));
le32_add_cpu(&nonce.d[0], offset / CHACHA_BLOCK_SIZE);
return nonce;
}
static inline struct nonce null_nonce(void)
{
struct nonce ret;
memset(&ret, 0, sizeof(ret));
return ret;
}
static inline struct nonce extent_nonce(struct bversion version,
struct bch_extent_crc_unpacked crc)
{
unsigned size = crc.compression_type ? crc.uncompressed_size : 0;
struct nonce nonce = (struct nonce) {{
[0] = cpu_to_le32(size << 22),
[1] = cpu_to_le32(version.lo),
[2] = cpu_to_le32(version.lo >> 32),
[3] = cpu_to_le32(version.hi|
(crc.compression_type << 24))^BCH_NONCE_EXTENT,
}};
return nonce_add(nonce, crc.nonce << 9);
}
static inline bool bch2_key_is_encrypted(struct bch_encrypted_key *key)
{
return le64_to_cpu(key->magic) != BCH_KEY_MAGIC;
}
static inline struct nonce __bch2_sb_key_nonce(struct bch_sb *sb)
{
__le64 magic = __bch2_sb_magic(sb);
return (struct nonce) {{
[0] = 0,
[1] = 0,
[2] = ((__le32 *) &magic)[0],
[3] = ((__le32 *) &magic)[1],
}};
}
static inline struct nonce bch2_sb_key_nonce(struct bch_fs *c)
{
__le64 magic = bch2_sb_magic(c);
return (struct nonce) {{
[0] = 0,
[1] = 0,
[2] = ((__le32 *) &magic)[0],
[3] = ((__le32 *) &magic)[1],
}};
}
#endif /* _BCACHEFS_CHECKSUM_H */