linux/fs/bcachefs/str_hash.h
Kent Overstreet 098ef98d5b bcachefs: Add private error codes for ENOSPC
Continuing the saga of introducing private dedicated error codes for
each error path, this patch converts ENOSPC to error codes that are
subtypes of ENOSPC. We've recently had a test failure where we got
-ENOSPC where we shouldn't have, and didn't have enough information to
tell where it came from, so this patch will solve that problem.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:40 -04:00

371 lines
8.6 KiB
C

/* 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 ?: -ENOENT;
}
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 = -ENOENT;
} 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 */