linux/fs/bcachefs/bkey.h
Kent Overstreet e751c01a8e bcachefs: Start using bpos.snapshot field
This patch starts treating the bpos.snapshot field like part of the key
in the btree code:

* bpos_successor() and bpos_predecessor() now include the snapshot field
* Keys in btrees that will be using snapshots (extents, inodes, dirents
  and xattrs) now always have their snapshot field set to U32_MAX

The btree iterator code gets a new flag, BTREE_ITER_ALL_SNAPSHOTS, that
determines whether we're iterating over keys in all snapshots or not -
internally, this controlls whether bkey_(successor|predecessor)
increment/decrement the snapshot field, or only the higher bits of the
key.

We add a new member to struct btree_iter, iter->snapshot: when
BTREE_ITER_ALL_SNAPSHOTS is not set, iter->pos.snapshot should always
equal iter->snapshot, which will be 0 for btrees that don't use
snapshots, and alsways U32_MAX for btrees that will use snapshots
(until we enable snapshot creation).

This patch also introduces a new metadata version number, and compat
code for reading from/writing to older versions - this isn't a forced
upgrade (yet).

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:08:57 -04:00

606 lines
15 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _BCACHEFS_BKEY_H
#define _BCACHEFS_BKEY_H
#include <linux/bug.h>
#include "bcachefs_format.h"
#include "util.h"
#include "vstructs.h"
#if 0
/*
* compiled unpack functions are disabled, pending a new interface for
* dynamically allocating executable memory:
*/
#ifdef CONFIG_X86_64
#define HAVE_BCACHEFS_COMPILED_UNPACK 1
#endif
#endif
void bch2_to_binary(char *, const u64 *, unsigned);
/* bkey with split value, const */
struct bkey_s_c {
const struct bkey *k;
const struct bch_val *v;
};
/* bkey with split value */
struct bkey_s {
union {
struct {
struct bkey *k;
struct bch_val *v;
};
struct bkey_s_c s_c;
};
};
#define bkey_next(_k) vstruct_next(_k)
#define bkey_val_u64s(_k) ((_k)->u64s - BKEY_U64s)
static inline size_t bkey_val_bytes(const struct bkey *k)
{
return bkey_val_u64s(k) * sizeof(u64);
}
static inline void set_bkey_val_u64s(struct bkey *k, unsigned val_u64s)
{
k->u64s = BKEY_U64s + val_u64s;
}
static inline void set_bkey_val_bytes(struct bkey *k, unsigned bytes)
{
k->u64s = BKEY_U64s + DIV_ROUND_UP(bytes, sizeof(u64));
}
#define bkey_val_end(_k) ((void *) (((u64 *) (_k).v) + bkey_val_u64s((_k).k)))
#define bkey_deleted(_k) ((_k)->type == KEY_TYPE_deleted)
#define bkey_whiteout(_k) \
((_k)->type == KEY_TYPE_deleted || (_k)->type == KEY_TYPE_discard)
enum bkey_lr_packed {
BKEY_PACKED_BOTH,
BKEY_PACKED_RIGHT,
BKEY_PACKED_LEFT,
BKEY_PACKED_NONE,
};
#define bkey_lr_packed(_l, _r) \
((_l)->format + ((_r)->format << 1))
#define bkey_copy(_dst, _src) \
do { \
BUILD_BUG_ON(!type_is(_dst, struct bkey_i *) && \
!type_is(_dst, struct bkey_packed *)); \
BUILD_BUG_ON(!type_is(_src, struct bkey_i *) && \
!type_is(_src, struct bkey_packed *)); \
EBUG_ON((u64 *) (_dst) > (u64 *) (_src) && \
(u64 *) (_dst) < (u64 *) (_src) + \
((struct bkey *) (_src))->u64s); \
\
memcpy_u64s_small((_dst), (_src), \
((struct bkey *) (_src))->u64s); \
} while (0)
struct btree;
struct bkey_format_state {
u64 field_min[BKEY_NR_FIELDS];
u64 field_max[BKEY_NR_FIELDS];
};
void bch2_bkey_format_init(struct bkey_format_state *);
void bch2_bkey_format_add_key(struct bkey_format_state *, const struct bkey *);
void bch2_bkey_format_add_pos(struct bkey_format_state *, struct bpos);
struct bkey_format bch2_bkey_format_done(struct bkey_format_state *);
const char *bch2_bkey_format_validate(struct bkey_format *);
__pure
unsigned bch2_bkey_greatest_differing_bit(const struct btree *,
const struct bkey_packed *,
const struct bkey_packed *);
__pure
unsigned bch2_bkey_ffs(const struct btree *, const struct bkey_packed *);
__pure
int __bch2_bkey_cmp_packed_format_checked(const struct bkey_packed *,
const struct bkey_packed *,
const struct btree *);
__pure
int __bch2_bkey_cmp_left_packed_format_checked(const struct btree *,
const struct bkey_packed *,
const struct bpos *);
__pure
int bch2_bkey_cmp_packed(const struct btree *,
const struct bkey_packed *,
const struct bkey_packed *);
__pure
int __bch2_bkey_cmp_left_packed(const struct btree *,
const struct bkey_packed *,
const struct bpos *);
static inline __pure
int bkey_cmp_left_packed(const struct btree *b,
const struct bkey_packed *l, const struct bpos *r)
{
return __bch2_bkey_cmp_left_packed(b, l, r);
}
/*
* we prefer to pass bpos by ref, but it's often enough terribly convenient to
* pass it by by val... as much as I hate c++, const ref would be nice here:
*/
__pure __flatten
static inline int bkey_cmp_left_packed_byval(const struct btree *b,
const struct bkey_packed *l,
struct bpos r)
{
return bkey_cmp_left_packed(b, l, &r);
}
static __always_inline int bpos_cmp(struct bpos l, struct bpos r)
{
return cmp_int(l.inode, r.inode) ?:
cmp_int(l.offset, r.offset) ?:
cmp_int(l.snapshot, r.snapshot);
}
static __always_inline int bkey_cmp(struct bpos l, struct bpos r)
{
return cmp_int(l.inode, r.inode) ?:
cmp_int(l.offset, r.offset);
}
static inline struct bpos bpos_min(struct bpos l, struct bpos r)
{
return bpos_cmp(l, r) < 0 ? l : r;
}
static inline struct bpos bpos_max(struct bpos l, struct bpos r)
{
return bpos_cmp(l, r) > 0 ? l : r;
}
#define sbb(a, b, borrow) \
do { \
typeof(a) d1, d2; \
\
d1 = a - borrow; \
borrow = d1 > a; \
\
d2 = d1 - b; \
borrow += d2 > d1; \
a = d2; \
} while (0)
/* returns a - b: */
static inline struct bpos bpos_sub(struct bpos a, struct bpos b)
{
int borrow = 0;
sbb(a.snapshot, b.snapshot, borrow);
sbb(a.offset, b.offset, borrow);
sbb(a.inode, b.inode, borrow);
return a;
}
static inline struct bpos bpos_diff(struct bpos l, struct bpos r)
{
if (bpos_cmp(l, r) > 0)
swap(l, r);
return bpos_sub(r, l);
}
void bch2_bpos_swab(struct bpos *);
void bch2_bkey_swab_key(const struct bkey_format *, struct bkey_packed *);
static __always_inline int bversion_cmp(struct bversion l, struct bversion r)
{
return cmp_int(l.hi, r.hi) ?:
cmp_int(l.lo, r.lo);
}
#define ZERO_VERSION ((struct bversion) { .hi = 0, .lo = 0 })
#define MAX_VERSION ((struct bversion) { .hi = ~0, .lo = ~0ULL })
static __always_inline int bversion_zero(struct bversion v)
{
return !bversion_cmp(v, ZERO_VERSION);
}
#ifdef CONFIG_BCACHEFS_DEBUG
/* statement expressions confusing unlikely()? */
#define bkey_packed(_k) \
({ EBUG_ON((_k)->format > KEY_FORMAT_CURRENT); \
(_k)->format != KEY_FORMAT_CURRENT; })
#else
#define bkey_packed(_k) ((_k)->format != KEY_FORMAT_CURRENT)
#endif
/*
* It's safe to treat an unpacked bkey as a packed one, but not the reverse
*/
static inline struct bkey_packed *bkey_to_packed(struct bkey_i *k)
{
return (struct bkey_packed *) k;
}
static inline const struct bkey_packed *bkey_to_packed_c(const struct bkey_i *k)
{
return (const struct bkey_packed *) k;
}
static inline struct bkey_i *packed_to_bkey(struct bkey_packed *k)
{
return bkey_packed(k) ? NULL : (struct bkey_i *) k;
}
static inline const struct bkey *packed_to_bkey_c(const struct bkey_packed *k)
{
return bkey_packed(k) ? NULL : (const struct bkey *) k;
}
static inline unsigned bkey_format_key_bits(const struct bkey_format *format)
{
return format->bits_per_field[BKEY_FIELD_INODE] +
format->bits_per_field[BKEY_FIELD_OFFSET] +
format->bits_per_field[BKEY_FIELD_SNAPSHOT];
}
static inline struct bpos bpos_successor(struct bpos p)
{
if (!++p.snapshot &&
!++p.offset &&
!++p.inode)
BUG();
return p;
}
static inline struct bpos bpos_predecessor(struct bpos p)
{
if (!p.snapshot-- &&
!p.offset-- &&
!p.inode--)
BUG();
return p;
}
static inline struct bpos bpos_nosnap_successor(struct bpos p)
{
p.snapshot = 0;
if (!++p.offset &&
!++p.inode)
BUG();
return p;
}
static inline struct bpos bpos_nosnap_predecessor(struct bpos p)
{
p.snapshot = 0;
if (!p.offset-- &&
!p.inode--)
BUG();
return p;
}
static inline u64 bkey_start_offset(const struct bkey *k)
{
return k->p.offset - k->size;
}
static inline struct bpos bkey_start_pos(const struct bkey *k)
{
return (struct bpos) {
.inode = k->p.inode,
.offset = bkey_start_offset(k),
.snapshot = k->p.snapshot,
};
}
/* Packed helpers */
static inline unsigned bkeyp_key_u64s(const struct bkey_format *format,
const struct bkey_packed *k)
{
unsigned ret = bkey_packed(k) ? format->key_u64s : BKEY_U64s;
EBUG_ON(k->u64s < ret);
return ret;
}
static inline unsigned bkeyp_key_bytes(const struct bkey_format *format,
const struct bkey_packed *k)
{
return bkeyp_key_u64s(format, k) * sizeof(u64);
}
static inline unsigned bkeyp_val_u64s(const struct bkey_format *format,
const struct bkey_packed *k)
{
return k->u64s - bkeyp_key_u64s(format, k);
}
static inline size_t bkeyp_val_bytes(const struct bkey_format *format,
const struct bkey_packed *k)
{
return bkeyp_val_u64s(format, k) * sizeof(u64);
}
static inline void set_bkeyp_val_u64s(const struct bkey_format *format,
struct bkey_packed *k, unsigned val_u64s)
{
k->u64s = bkeyp_key_u64s(format, k) + val_u64s;
}
#define bkeyp_val(_format, _k) \
((struct bch_val *) ((_k)->_data + bkeyp_key_u64s(_format, _k)))
extern const struct bkey_format bch2_bkey_format_current;
bool bch2_bkey_transform(const struct bkey_format *,
struct bkey_packed *,
const struct bkey_format *,
const struct bkey_packed *);
struct bkey __bch2_bkey_unpack_key(const struct bkey_format *,
const struct bkey_packed *);
#ifndef HAVE_BCACHEFS_COMPILED_UNPACK
struct bpos __bkey_unpack_pos(const struct bkey_format *,
const struct bkey_packed *);
#endif
bool bch2_bkey_pack_key(struct bkey_packed *, const struct bkey *,
const struct bkey_format *);
enum bkey_pack_pos_ret {
BKEY_PACK_POS_EXACT,
BKEY_PACK_POS_SMALLER,
BKEY_PACK_POS_FAIL,
};
enum bkey_pack_pos_ret bch2_bkey_pack_pos_lossy(struct bkey_packed *, struct bpos,
const struct btree *);
static inline bool bkey_pack_pos(struct bkey_packed *out, struct bpos in,
const struct btree *b)
{
return bch2_bkey_pack_pos_lossy(out, in, b) == BKEY_PACK_POS_EXACT;
}
void bch2_bkey_unpack(const struct btree *, struct bkey_i *,
const struct bkey_packed *);
bool bch2_bkey_pack(struct bkey_packed *, const struct bkey_i *,
const struct bkey_format *);
static inline u64 bkey_field_max(const struct bkey_format *f,
enum bch_bkey_fields nr)
{
return f->bits_per_field[nr] < 64
? (le64_to_cpu(f->field_offset[nr]) +
~(~0ULL << f->bits_per_field[nr]))
: U64_MAX;
}
#ifdef HAVE_BCACHEFS_COMPILED_UNPACK
int bch2_compile_bkey_format(const struct bkey_format *, void *);
#else
static inline int bch2_compile_bkey_format(const struct bkey_format *format,
void *out) { return 0; }
#endif
static inline void bkey_reassemble(struct bkey_i *dst,
struct bkey_s_c src)
{
dst->k = *src.k;
memcpy_u64s_small(&dst->v, src.v, bkey_val_u64s(src.k));
}
#define bkey_s_null ((struct bkey_s) { .k = NULL })
#define bkey_s_c_null ((struct bkey_s_c) { .k = NULL })
#define bkey_s_err(err) ((struct bkey_s) { .k = ERR_PTR(err) })
#define bkey_s_c_err(err) ((struct bkey_s_c) { .k = ERR_PTR(err) })
static inline struct bkey_s bkey_to_s(struct bkey *k)
{
return (struct bkey_s) { .k = k, .v = NULL };
}
static inline struct bkey_s_c bkey_to_s_c(const struct bkey *k)
{
return (struct bkey_s_c) { .k = k, .v = NULL };
}
static inline struct bkey_s bkey_i_to_s(struct bkey_i *k)
{
return (struct bkey_s) { .k = &k->k, .v = &k->v };
}
static inline struct bkey_s_c bkey_i_to_s_c(const struct bkey_i *k)
{
return (struct bkey_s_c) { .k = &k->k, .v = &k->v };
}
/*
* For a given type of value (e.g. struct bch_extent), generates the types for
* bkey + bch_extent - inline, split, split const - and also all the conversion
* functions, which also check that the value is of the correct type.
*
* We use anonymous unions for upcasting - e.g. converting from e.g. a
* bkey_i_extent to a bkey_i - since that's always safe, instead of conversion
* functions.
*/
#define x(name, ...) \
struct bkey_i_##name { \
union { \
struct bkey k; \
struct bkey_i k_i; \
}; \
struct bch_##name v; \
}; \
\
struct bkey_s_c_##name { \
union { \
struct { \
const struct bkey *k; \
const struct bch_##name *v; \
}; \
struct bkey_s_c s_c; \
}; \
}; \
\
struct bkey_s_##name { \
union { \
struct { \
struct bkey *k; \
struct bch_##name *v; \
}; \
struct bkey_s_c_##name c; \
struct bkey_s s; \
struct bkey_s_c s_c; \
}; \
}; \
\
static inline struct bkey_i_##name *bkey_i_to_##name(struct bkey_i *k) \
{ \
EBUG_ON(k->k.type != KEY_TYPE_##name); \
return container_of(&k->k, struct bkey_i_##name, k); \
} \
\
static inline const struct bkey_i_##name * \
bkey_i_to_##name##_c(const struct bkey_i *k) \
{ \
EBUG_ON(k->k.type != KEY_TYPE_##name); \
return container_of(&k->k, struct bkey_i_##name, k); \
} \
\
static inline struct bkey_s_##name bkey_s_to_##name(struct bkey_s k) \
{ \
EBUG_ON(k.k->type != KEY_TYPE_##name); \
return (struct bkey_s_##name) { \
.k = k.k, \
.v = container_of(k.v, struct bch_##name, v), \
}; \
} \
\
static inline struct bkey_s_c_##name bkey_s_c_to_##name(struct bkey_s_c k)\
{ \
EBUG_ON(k.k->type != KEY_TYPE_##name); \
return (struct bkey_s_c_##name) { \
.k = k.k, \
.v = container_of(k.v, struct bch_##name, v), \
}; \
} \
\
static inline struct bkey_s_##name name##_i_to_s(struct bkey_i_##name *k)\
{ \
return (struct bkey_s_##name) { \
.k = &k->k, \
.v = &k->v, \
}; \
} \
\
static inline struct bkey_s_c_##name \
name##_i_to_s_c(const struct bkey_i_##name *k) \
{ \
return (struct bkey_s_c_##name) { \
.k = &k->k, \
.v = &k->v, \
}; \
} \
\
static inline struct bkey_s_##name bkey_i_to_s_##name(struct bkey_i *k) \
{ \
EBUG_ON(k->k.type != KEY_TYPE_##name); \
return (struct bkey_s_##name) { \
.k = &k->k, \
.v = container_of(&k->v, struct bch_##name, v), \
}; \
} \
\
static inline struct bkey_s_c_##name \
bkey_i_to_s_c_##name(const struct bkey_i *k) \
{ \
EBUG_ON(k->k.type != KEY_TYPE_##name); \
return (struct bkey_s_c_##name) { \
.k = &k->k, \
.v = container_of(&k->v, struct bch_##name, v), \
}; \
} \
\
static inline struct bkey_i_##name *bkey_##name##_init(struct bkey_i *_k)\
{ \
struct bkey_i_##name *k = \
container_of(&_k->k, struct bkey_i_##name, k); \
\
bkey_init(&k->k); \
memset(&k->v, 0, sizeof(k->v)); \
k->k.type = KEY_TYPE_##name; \
set_bkey_val_bytes(&k->k, sizeof(k->v)); \
\
return k; \
}
BCH_BKEY_TYPES();
#undef x
/* byte order helpers */
#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
static inline unsigned high_word_offset(const struct bkey_format *f)
{
return f->key_u64s - 1;
}
#define high_bit_offset 0
#define nth_word(p, n) ((p) - (n))
#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
static inline unsigned high_word_offset(const struct bkey_format *f)
{
return 0;
}
#define high_bit_offset KEY_PACKED_BITS_START
#define nth_word(p, n) ((p) + (n))
#else
#error edit for your odd byteorder.
#endif
#define high_word(f, k) ((k)->_data + high_word_offset(f))
#define next_word(p) nth_word(p, 1)
#define prev_word(p) nth_word(p, -1)
#ifdef CONFIG_BCACHEFS_DEBUG
void bch2_bkey_pack_test(void);
#else
static inline void bch2_bkey_pack_test(void) {}
#endif
#endif /* _BCACHEFS_BKEY_H */