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bcachefs: Don't use sha256 for siphash str hash key

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With the refactoring that's coming to add fuse support, we want
bch2_hash_info_init() to be cheaper so we don't have to rely on anything
cached besides the inode in the btree.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This commit is contained in:
Kent Overstreet 2019-10-04 15:58:43 -04:00 committed by Kent Overstreet
parent bd09d26897
commit 73501ab82c
4 changed files with 41 additions and 20 deletions
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15
fs/bcachefs/bcachefs_format.h
View File

@ -1318,6 +1318,7 @@ enum bch_sb_features {
BCH_FEATURE_EC = 4,
BCH_FEATURE_JOURNAL_SEQ_BLACKLIST_V3 = 5,
BCH_FEATURE_REFLINK = 6,
BCH_FEATURE_NEW_SIPHASH = 7,
BCH_FEATURE_NR,
};
@ -1344,11 +1345,19 @@ enum bch_csum_opts {
BCH_CSUM_OPT_NR = 3,
};
enum bch_str_hash_opts {
enum bch_str_hash_type {
BCH_STR_HASH_CRC32C = 0,
BCH_STR_HASH_CRC64 = 1,
BCH_STR_HASH_SIPHASH = 2,
BCH_STR_HASH_NR = 3,
BCH_STR_HASH_SIPHASH_OLD = 2,
BCH_STR_HASH_SIPHASH = 3,
BCH_STR_HASH_NR = 4,
};
enum bch_str_hash_opts {
BCH_STR_HASH_OPT_CRC32C = 0,
BCH_STR_HASH_OPT_CRC64 = 1,
BCH_STR_HASH_OPT_SIPHASH = 2,
BCH_STR_HASH_OPT_NR = 3,
};
#define BCH_COMPRESSION_TYPES() \

7
fs/bcachefs/inode.c
View File

@ -6,8 +6,7 @@
#include "error.h"
#include "extents.h"
#include "inode.h"
#include "io.h"
#include "keylist.h"
#include "str_hash.h"
#include <linux/random.h>
@ -303,11 +302,13 @@ void bch2_inode_init(struct bch_fs *c, struct bch_inode_unpacked *inode_u,
struct bch_inode_unpacked *parent)
{
s64 now = bch2_current_time(c);
enum bch_str_hash_type str_hash =
bch2_str_hash_opt_to_type(c, c->opts.str_hash);
memset(inode_u, 0, sizeof(*inode_u));
/* ick */
inode_u->bi_flags |= c->opts.str_hash << INODE_STR_HASH_OFFSET;
inode_u->bi_flags |= str_hash << INODE_STR_HASH_OFFSET;
get_random_bytes(&inode_u->bi_hash_seed,
sizeof(inode_u->bi_hash_seed));

2
fs/bcachefs/opts.h
View File

@ -127,7 +127,7 @@ enum opt_type {
x(str_hash, u8, \
OPT_FORMAT|OPT_MOUNT|OPT_RUNTIME, \
OPT_STR(bch2_str_hash_types), \
BCH_SB_STR_HASH_TYPE, BCH_STR_HASH_SIPHASH, \
BCH_SB_STR_HASH_TYPE, BCH_STR_HASH_OPT_SIPHASH, \
NULL, "Hash function for directory entries and xattrs")\
x(foreground_target, u16, \
OPT_FORMAT|OPT_MOUNT|OPT_RUNTIME|OPT_INODE, \

37
fs/bcachefs/str_hash.h
View File

@ -14,6 +14,23 @@
#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;
union {
@ -23,21 +40,16 @@ struct bch_hash_info {
};
static inline struct bch_hash_info
bch2_hash_info_init(struct bch_fs *c,
const struct bch_inode_unpacked *bi)
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)
~(~0U << INODE_STR_HASH_BITS),
.crc_key = bi->bi_hash_seed,
};
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: {
if (unlikely(info.type == BCH_STR_HASH_SIPHASH_OLD)) {
SHASH_DESC_ON_STACK(desc, c->sha256);
u8 digest[SHA256_DIGEST_SIZE];
@ -46,10 +58,6 @@ bch2_hash_info_init(struct bch_fs *c,
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;
@ -73,6 +81,7 @@ static inline void bch2_str_hash_init(struct bch_str_hash_ctx *ctx,
case BCH_STR_HASH_CRC64:
ctx->crc64 = crc64_be(~0, &info->crc_key, sizeof(info->crc_key));
break;
case BCH_STR_HASH_SIPHASH_OLD:
case BCH_STR_HASH_SIPHASH:
SipHash24_Init(&ctx->siphash, &info->siphash_key);
break;
@ -92,6 +101,7 @@ static inline void bch2_str_hash_update(struct bch_str_hash_ctx *ctx,
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;
@ -108,6 +118,7 @@ static inline u64 bch2_str_hash_end(struct bch_str_hash_ctx *ctx,
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: