// SPDX-License-Identifier: GPL-2.0
#include "bcachefs.h"
#include "bkey.h"
#include "bkey_cmp.h"
#include "bkey_methods.h"
#include "bset.h"
#include "util.h"
const struct bkey_format bch2_bkey_format_current = BKEY_FORMAT_CURRENT;
void bch2_bkey_packed_to_binary_text(struct printbuf *out,
const struct bkey_format *f,
const struct bkey_packed *k)
{
const u64 *p = high_word(f, k);
unsigned word_bits = 64 - high_bit_offset;
unsigned nr_key_bits = bkey_format_key_bits(f) + high_bit_offset;
u64 v = *p & (~0ULL >> high_bit_offset);
if (!nr_key_bits) {
prt_str(out, "(empty)");
return;
}
while (1) {
unsigned next_key_bits = nr_key_bits;
if (nr_key_bits < 64) {
v >>= 64 - nr_key_bits;
next_key_bits = 0;
} else {
next_key_bits -= 64;
}
bch2_prt_u64_base2_nbits(out, v, min(word_bits, nr_key_bits));
if (!next_key_bits)
break;
prt_char(out, ' ');
p = next_word(p);
v = *p;
word_bits = 64;
nr_key_bits = next_key_bits;
}
}
#ifdef CONFIG_BCACHEFS_DEBUG
static void bch2_bkey_pack_verify(const struct bkey_packed *packed,
const struct bkey *unpacked,
const struct bkey_format *format)
{
struct bkey tmp;
BUG_ON(bkeyp_val_u64s(format, packed) !=
bkey_val_u64s(unpacked));
BUG_ON(packed->u64s < bkeyp_key_u64s(format, packed));
tmp = __bch2_bkey_unpack_key(format, packed);
if (memcmp(&tmp, unpacked, sizeof(struct bkey))) {
struct printbuf buf = PRINTBUF;
prt_printf(&buf, "keys differ: format u64s %u fields %u %u %u %u %u\n",
format->key_u64s,
format->bits_per_field[0],
format->bits_per_field[1],
format->bits_per_field[2],
format->bits_per_field[3],
format->bits_per_field[4]);
prt_printf(&buf, "compiled unpack: ");
bch2_bkey_to_text(&buf, unpacked);
prt_newline(&buf);
prt_printf(&buf, "c unpack: ");
bch2_bkey_to_text(&buf, &tmp);
prt_newline(&buf);
prt_printf(&buf, "compiled unpack: ");
bch2_bkey_packed_to_binary_text(&buf, &bch2_bkey_format_current,
(struct bkey_packed *) unpacked);
prt_newline(&buf);
prt_printf(&buf, "c unpack: ");
bch2_bkey_packed_to_binary_text(&buf, &bch2_bkey_format_current,
(struct bkey_packed *) &tmp);
prt_newline(&buf);
panic("%s", buf.buf);
}
}
#else
static inline void bch2_bkey_pack_verify(const struct bkey_packed *packed,
const struct bkey *unpacked,
const struct bkey_format *format) {}
#endif
struct pack_state {
const struct bkey_format *format;
unsigned bits; /* bits remaining in current word */
u64 w; /* current word */
u64 *p; /* pointer to next word */
};
__always_inline
static struct pack_state pack_state_init(const struct bkey_format *format,
struct bkey_packed *k)
{
u64 *p = high_word(format, k);
return (struct pack_state) {
.format = format,
.bits = 64 - high_bit_offset,
.w = 0,
.p = p,
};
}
__always_inline
static void pack_state_finish(struct pack_state *state,
struct bkey_packed *k)
{
EBUG_ON(state->p < k->_data);
EBUG_ON(state->p >= (u64 *) k->_data + state->format->key_u64s);
*state->p = state->w;
}
struct unpack_state {
const struct bkey_format *format;
unsigned bits; /* bits remaining in current word */
u64 w; /* current word */
const u64 *p; /* pointer to next word */
};
__always_inline
static struct unpack_state unpack_state_init(const struct bkey_format *format,
const struct bkey_packed *k)
{
const u64 *p = high_word(format, k);
return (struct unpack_state) {
.format = format,
.bits = 64 - high_bit_offset,
.w = *p << high_bit_offset,
.p = p,
};
}
__always_inline
static u64 get_inc_field(struct unpack_state *state, unsigned field)
{
unsigned bits = state->format->bits_per_field[field];
u64 v = 0, offset = le64_to_cpu(state->format->field_offset[field]);
if (bits >= state->bits) {
v = state->w >> (64 - bits);
bits -= state->bits;
state->p = next_word(state->p);
state->w = *state->p;
state->bits = 64;
}
/* avoid shift by 64 if bits is 0 - bits is never 64 here: */
v |= (state->w >> 1) >> (63 - bits);
state->w <<= bits;
state->bits -= bits;
return v + offset;
}
__always_inline
static void __set_inc_field(struct pack_state *state, unsigned field, u64 v)
{
unsigned bits = state->format->bits_per_field[field];
if (bits) {
if (bits > state->bits) {
bits -= state->bits;
/* avoid shift by 64 if bits is 64 - bits is never 0 here: */
state->w |= (v >> 1) >> (bits - 1);
*state->p = state->w;
state->p = next_word(state->p);
state->w = 0;
state->bits = 64;
}
state->bits -= bits;
state->w |= v << state->bits;
}
}
__always_inline
static bool set_inc_field(struct pack_state *state, unsigned field, u64 v)
{
unsigned bits = state->format->bits_per_field[field];
u64 offset = le64_to_cpu(state->format->field_offset[field]);
if (v < offset)
return false;
v -= offset;
if (fls64(v) > bits)
return false;
__set_inc_field(state, field, v);
return true;
}
/*
* Note: does NOT set out->format (we don't know what it should be here!)
*
* Also: doesn't work on extents - it doesn't preserve the invariant that
* if k is packed bkey_start_pos(k) will successfully pack
*/
static bool bch2_bkey_transform_key(const struct bkey_format *out_f,
struct bkey_packed *out,
const struct bkey_format *in_f,
const struct bkey_packed *in)
{
struct pack_state out_s = pack_state_init(out_f, out);
struct unpack_state in_s = unpack_state_init(in_f, in);
u64 *w = out->_data;
unsigned i;
*w = 0;
for (i = 0; i < BKEY_NR_FIELDS; i++)
if (!set_inc_field(&out_s, i, get_inc_field(&in_s, i)))
return false;
/* Can't happen because the val would be too big to unpack: */
EBUG_ON(in->u64s - in_f->key_u64s + out_f->key_u64s > U8_MAX);
pack_state_finish(&out_s, out);
out->u64s = out_f->key_u64s + in->u64s - in_f->key_u64s;
out->needs_whiteout = in->needs_whiteout;
out->type = in->type;
return true;
}
bool bch2_bkey_transform(const struct bkey_format *out_f,
struct bkey_packed *out,
const struct bkey_format *in_f,
const struct bkey_packed *in)
{
if (!bch2_bkey_transform_key(out_f, out, in_f, in))
return false;
memcpy_u64s((u64 *) out + out_f->key_u64s,
(u64 *) in + in_f->key_u64s,
(in->u64s - in_f->key_u64s));
return true;
}
struct bkey __bch2_bkey_unpack_key(const struct bkey_format *format,
const struct bkey_packed *in)
{
struct unpack_state state = unpack_state_init(format, in);
struct bkey out;
EBUG_ON(format->nr_fields != BKEY_NR_FIELDS);
EBUG_ON(in->u64s < format->key_u64s);
EBUG_ON(in->format != KEY_FORMAT_LOCAL_BTREE);
EBUG_ON(in->u64s - format->key_u64s + BKEY_U64s > U8_MAX);
out.u64s = BKEY_U64s + in->u64s - format->key_u64s;
out.format = KEY_FORMAT_CURRENT;
out.needs_whiteout = in->needs_whiteout;
out.type = in->type;
out.pad[0] = 0;
#define x(id, field) out.field = get_inc_field(&state, id);
bkey_fields()
#undef x
return out;
}
#ifndef HAVE_BCACHEFS_COMPILED_UNPACK
struct bpos __bkey_unpack_pos(const struct bkey_format *format,
const struct bkey_packed *in)
{
struct unpack_state state = unpack_state_init(format, in);
struct bpos out;
EBUG_ON(format->nr_fields != BKEY_NR_FIELDS);
EBUG_ON(in->u64s < format->key_u64s);
EBUG_ON(in->format != KEY_FORMAT_LOCAL_BTREE);
out.inode = get_inc_field(&state, BKEY_FIELD_INODE);
out.offset = get_inc_field(&state, BKEY_FIELD_OFFSET);
out.snapshot = get_inc_field(&state, BKEY_FIELD_SNAPSHOT);
return out;
}
#endif
/**
* bch2_bkey_pack_key -- pack just the key, not the value
* @out: packed result
* @in: key to pack
* @format: format of packed result
*
* Returns: true on success, false on failure
*/
bool bch2_bkey_pack_key(struct bkey_packed *out, const struct bkey *in,
const struct bkey_format *format)
{
struct pack_state state = pack_state_init(format, out);
u64 *w = out->_data;
EBUG_ON((void *) in == (void *) out);
EBUG_ON(format->nr_fields != BKEY_NR_FIELDS);
EBUG_ON(in->format != KEY_FORMAT_CURRENT);
*w = 0;
#define x(id, field) if (!set_inc_field(&state, id, in->field)) return false;
bkey_fields()
#undef x
pack_state_finish(&state, out);
out->u64s = format->key_u64s + in->u64s - BKEY_U64s;
out->format = KEY_FORMAT_LOCAL_BTREE;
out->needs_whiteout = in->needs_whiteout;
out->type = in->type;
bch2_bkey_pack_verify(out, in, format);
return true;
}
/**
* bch2_bkey_unpack -- unpack the key and the value
* @b: btree node of @src key (for packed format)
* @dst: unpacked result
* @src: packed input
*/
void bch2_bkey_unpack(const struct btree *b, struct bkey_i *dst,
const struct bkey_packed *src)
{
__bkey_unpack_key(b, &dst->k, src);
memcpy_u64s(&dst->v,
bkeyp_val(&b->format, src),
bkeyp_val_u64s(&b->format, src));
}
/**
* bch2_bkey_pack -- pack the key and the value
* @dst: packed result
* @src: unpacked input
* @format: format of packed result
*
* Returns: true on success, false on failure
*/
bool bch2_bkey_pack(struct bkey_packed *dst, const struct bkey_i *src,
const struct bkey_format *format)
{
struct bkey_packed tmp;
if (!bch2_bkey_pack_key(&tmp, &src->k, format))
return false;
memmove_u64s((u64 *) dst + format->key_u64s,
&src->v,
bkey_val_u64s(&src->k));
memcpy_u64s_small(dst, &tmp, format->key_u64s);
return true;
}
__always_inline
static bool set_inc_field_lossy(struct pack_state *state, unsigned field, u64 v)
{
unsigned bits = state->format->bits_per_field[field];
u64 offset = le64_to_cpu(state->format->field_offset[field]);
bool ret = true;
EBUG_ON(v < offset);
v -= offset;
if (fls64(v) > bits) {
v = ~(~0ULL << bits);
ret = false;
}
__set_inc_field(state, field, v);
return ret;
}
#ifdef CONFIG_BCACHEFS_DEBUG
static bool bkey_packed_successor(struct bkey_packed *out,
const struct btree *b,
struct bkey_packed k)
{
const struct bkey_format *f = &b->format;
unsigned nr_key_bits = b->nr_key_bits;
unsigned first_bit, offset;
u64 *p;
EBUG_ON(b->nr_key_bits != bkey_format_key_bits(f));
if (!nr_key_bits)
return false;
*out = k;
first_bit = high_bit_offset + nr_key_bits - 1;
p = nth_word(high_word(f, out), first_bit >> 6);
offset = 63 - (first_bit & 63);
while (nr_key_bits) {
unsigned bits = min(64 - offset, nr_key_bits);
u64 mask = (~0ULL >> (64 - bits)) << offset;
if ((*p & mask) != mask) {
*p += 1ULL << offset;
EBUG_ON(bch2_bkey_cmp_packed(b, out, &k) <= 0);
return true;
}
*p &= ~mask;
p = prev_word(p);
nr_key_bits -= bits;
offset = 0;
}
return false;
}
static bool bkey_format_has_too_big_fields(const struct bkey_format *f)
{
for (unsigned i = 0; i < f->nr_fields; i++) {
unsigned unpacked_bits = bch2_bkey_format_current.bits_per_field[i];
u64 unpacked_max = ~((~0ULL << 1) << (unpacked_bits - 1));
u64 packed_max = f->bits_per_field[i]
? ~((~0ULL << 1) << (f->bits_per_field[i] - 1))
: 0;
u64 field_offset = le64_to_cpu(f->field_offset[i]);
if (packed_max + field_offset < packed_max ||
packed_max + field_offset > unpacked_max)
return true;
}
return false;
}
#endif
/*
* Returns a packed key that compares <= in
*
* This is used in bset_search_tree(), where we need a packed pos in order to be
* able to compare against the keys in the auxiliary search tree - and it's
* legal to use a packed pos that isn't equivalent to the original pos,
* _provided_ it compares <= to the original pos.
*/
enum bkey_pack_pos_ret bch2_bkey_pack_pos_lossy(struct bkey_packed *out,
struct bpos in,
const struct btree *b)
{
const struct bkey_format *f = &b->format;
struct pack_state state = pack_state_init(f, out);
u64 *w = out->_data;
#ifdef CONFIG_BCACHEFS_DEBUG
struct bpos orig = in;
#endif
bool exact = true;
unsigned i;
/*
* bch2_bkey_pack_key() will write to all of f->key_u64s, minus the 3
* byte header, but pack_pos() won't if the len/version fields are big
* enough - we need to make sure to zero them out:
*/
for (i = 0; i < f->key_u64s; i++)
w[i] = 0;
if (unlikely(in.snapshot <
le64_to_cpu(f->field_offset[BKEY_FIELD_SNAPSHOT]))) {
if (!in.offset-- &&
!in.inode--)
return BKEY_PACK_POS_FAIL;
in.snapshot = KEY_SNAPSHOT_MAX;
exact = false;
}
if (unlikely(in.offset <
le64_to_cpu(f->field_offset[BKEY_FIELD_OFFSET]))) {
if (!in.inode--)
return BKEY_PACK_POS_FAIL;
in.offset = KEY_OFFSET_MAX;
in.snapshot = KEY_SNAPSHOT_MAX;
exact = false;
}
if (unlikely(in.inode <
le64_to_cpu(f->field_offset[BKEY_FIELD_INODE])))
return BKEY_PACK_POS_FAIL;
if (unlikely(!set_inc_field_lossy(&state, BKEY_FIELD_INODE, in.inode))) {
in.offset = KEY_OFFSET_MAX;
in.snapshot = KEY_SNAPSHOT_MAX;
exact = false;
}
if (unlikely(!set_inc_field_lossy(&state, BKEY_FIELD_OFFSET, in.offset))) {
in.snapshot = KEY_SNAPSHOT_MAX;
exact = false;
}
if (unlikely(!set_inc_field_lossy(&state, BKEY_FIELD_SNAPSHOT, in.snapshot)))
exact = false;
pack_state_finish(&state, out);
out->u64s = f->key_u64s;
out->format = KEY_FORMAT_LOCAL_BTREE;
out->type = KEY_TYPE_deleted;
#ifdef CONFIG_BCACHEFS_DEBUG
if (exact) {
BUG_ON(bkey_cmp_left_packed(b, out, &orig));
} else {
struct bkey_packed successor;
BUG_ON(bkey_cmp_left_packed(b, out, &orig) >= 0);
BUG_ON(bkey_packed_successor(&successor, b, *out) &&
bkey_cmp_left_packed(b, &successor, &orig) < 0 &&
!bkey_format_has_too_big_fields(f));
}
#endif
return exact ? BKEY_PACK_POS_EXACT : BKEY_PACK_POS_SMALLER;
}
void bch2_bkey_format_init(struct bkey_format_state *s)
{
unsigned i;
for (i = 0; i < ARRAY_SIZE(s->field_min); i++)
s->field_min[i] = U64_MAX;
for (i = 0; i < ARRAY_SIZE(s->field_max); i++)
s->field_max[i] = 0;
/* Make sure we can store a size of 0: */
s->field_min[BKEY_FIELD_SIZE] = 0;
}
void bch2_bkey_format_add_pos(struct bkey_format_state *s, struct bpos p)
{
unsigned field = 0;
__bkey_format_add(s, field++, p.inode);
__bkey_format_add(s, field++, p.offset);
__bkey_format_add(s, field++, p.snapshot);
}
/*
* We don't want it to be possible for the packed format to represent fields
* bigger than a u64... that will cause confusion and issues (like with
* bkey_packed_successor())
*/
static void set_format_field(struct bkey_format *f, enum bch_bkey_fields i,
unsigned bits, u64 offset)
{
unsigned unpacked_bits = bch2_bkey_format_current.bits_per_field[i];
u64 unpacked_max = ~((~0ULL << 1) << (unpacked_bits - 1));
bits = min(bits, unpacked_bits);
offset = bits == unpacked_bits ? 0 : min(offset, unpacked_max - ((1ULL << bits) - 1));
f->bits_per_field[i] = bits;
f->field_offset[i] = cpu_to_le64(offset);
}
struct bkey_format bch2_bkey_format_done(struct bkey_format_state *s)
{
unsigned i, bits = KEY_PACKED_BITS_START;
struct bkey_format ret = {
.nr_fields = BKEY_NR_FIELDS,
};
for (i = 0; i < ARRAY_SIZE(s->field_min); i++) {
s->field_min[i] = min(s->field_min[i], s->field_max[i]);
set_format_field(&ret, i,
fls64(s->field_max[i] - s->field_min[i]),
s->field_min[i]);
bits += ret.bits_per_field[i];
}
/* allow for extent merging: */
if (ret.bits_per_field[BKEY_FIELD_SIZE]) {
unsigned b = min(4U, 32U - ret.bits_per_field[BKEY_FIELD_SIZE]);
ret.bits_per_field[BKEY_FIELD_SIZE] += b;
bits += b;
}
ret.key_u64s = DIV_ROUND_UP(bits, 64);
/* if we have enough spare bits, round fields up to nearest byte */
bits = ret.key_u64s * 64 - bits;
for (i = 0; i < ARRAY_SIZE(ret.bits_per_field); i++) {
unsigned r = round_up(ret.bits_per_field[i], 8) -
ret.bits_per_field[i];
if (r <= bits) {
set_format_field(&ret, i,
ret.bits_per_field[i] + r,
le64_to_cpu(ret.field_offset[i]));
bits -= r;
}
}
#ifdef CONFIG_BCACHEFS_DEBUG
{
struct printbuf buf = PRINTBUF;
BUG_ON(bch2_bkey_format_invalid(NULL, &ret, 0, &buf));
printbuf_exit(&buf);
}
#endif
return ret;
}
int bch2_bkey_format_invalid(struct bch_fs *c,
struct bkey_format *f,
enum bch_validate_flags flags,
struct printbuf *err)
{
unsigned i, bits = KEY_PACKED_BITS_START;
if (f->nr_fields != BKEY_NR_FIELDS) {
prt_printf(err, "incorrect number of fields: got %u, should be %u",
f->nr_fields, BKEY_NR_FIELDS);
return -BCH_ERR_invalid;
}
/*
* Verify that the packed format can't represent fields larger than the
* unpacked format:
*/
for (i = 0; i < f->nr_fields; i++) {
if ((!c || c->sb.version_min >= bcachefs_metadata_version_snapshot) &&
bch2_bkey_format_field_overflows(f, i)) {
unsigned unpacked_bits = bch2_bkey_format_current.bits_per_field[i];
u64 unpacked_max = ~((~0ULL << 1) << (unpacked_bits - 1));
unsigned packed_bits = min(64, f->bits_per_field[i]);
u64 packed_max = packed_bits
? ~((~0ULL << 1) << (packed_bits - 1))
: 0;
prt_printf(err, "field %u too large: %llu + %llu > %llu",
i, packed_max, le64_to_cpu(f->field_offset[i]), unpacked_max);
return -BCH_ERR_invalid;
}
bits += f->bits_per_field[i];
}
if (f->key_u64s != DIV_ROUND_UP(bits, 64)) {
prt_printf(err, "incorrect key_u64s: got %u, should be %u",
f->key_u64s, DIV_ROUND_UP(bits, 64));
return -BCH_ERR_invalid;
}
return 0;
}
void bch2_bkey_format_to_text(struct printbuf *out, const struct bkey_format *f)
{
prt_printf(out, "u64s %u fields ", f->key_u64s);
for (unsigned i = 0; i < ARRAY_SIZE(f->bits_per_field); i++) {
if (i)
prt_str(out, ", ");
prt_printf(out, "%u:%llu",
f->bits_per_field[i],
le64_to_cpu(f->field_offset[i]));
}
}
/*
* Most significant differing bit
* Bits are indexed from 0 - return is [0, nr_key_bits)
*/
__pure
unsigned bch2_bkey_greatest_differing_bit(const struct btree *b,
const struct bkey_packed *l_k,
const struct bkey_packed *r_k)
{
const u64 *l = high_word(&b->format, l_k);
const u64 *r = high_word(&b->format, r_k);
unsigned nr_key_bits = b->nr_key_bits;
unsigned word_bits = 64 - high_bit_offset;
u64 l_v, r_v;
EBUG_ON(b->nr_key_bits != bkey_format_key_bits(&b->format));
/* for big endian, skip past header */
l_v = *l & (~0ULL >> high_bit_offset);
r_v = *r & (~0ULL >> high_bit_offset);
while (nr_key_bits) {
if (nr_key_bits < word_bits) {
l_v >>= word_bits - nr_key_bits;
r_v >>= word_bits - nr_key_bits;
nr_key_bits = 0;
} else {
nr_key_bits -= word_bits;
}
if (l_v != r_v)
return fls64(l_v ^ r_v) - 1 + nr_key_bits;
l = next_word(l);
r = next_word(r);
l_v = *l;
r_v = *r;
word_bits = 64;
}
return 0;
}
/*
* First set bit
* Bits are indexed from 0 - return is [0, nr_key_bits)
*/
__pure
unsigned bch2_bkey_ffs(const struct btree *b, const struct bkey_packed *k)
{
const u64 *p = high_word(&b->format, k);
unsigned nr_key_bits = b->nr_key_bits;
unsigned ret = 0, offset;
EBUG_ON(b->nr_key_bits != bkey_format_key_bits(&b->format));
offset = nr_key_bits;
while (offset > 64) {
p = next_word(p);
offset -= 64;
}
offset = 64 - offset;
while (nr_key_bits) {
unsigned bits = nr_key_bits + offset < 64
? nr_key_bits
: 64 - offset;
u64 mask = (~0ULL >> (64 - bits)) << offset;
if (*p & mask)
return ret + __ffs64(*p & mask) - offset;
p = prev_word(p);
nr_key_bits -= bits;
ret += bits;
offset = 0;
}
return 0;
}
#ifdef HAVE_BCACHEFS_COMPILED_UNPACK
#define I(_x) (*(out)++ = (_x))
#define I1(i0) I(i0)
#define I2(i0, i1) (I1(i0), I(i1))
#define I3(i0, i1, i2) (I2(i0, i1), I(i2))
#define I4(i0, i1, i2, i3) (I3(i0, i1, i2), I(i3))
#define I5(i0, i1, i2, i3, i4) (I4(i0, i1, i2, i3), I(i4))
static u8 *compile_bkey_field(const struct bkey_format *format, u8 *out,
enum bch_bkey_fields field,
unsigned dst_offset, unsigned dst_size,
bool *eax_zeroed)
{
unsigned bits = format->bits_per_field[field];
u64 offset = le64_to_cpu(format->field_offset[field]);
unsigned i, byte, bit_offset, align, shl, shr;
if (!bits && !offset) {
if (!*eax_zeroed) {
/* xor eax, eax */
I2(0x31, 0xc0);
}
*eax_zeroed = true;
goto set_field;
}
if (!bits) {
/* just return offset: */
switch (dst_size) {
case 8:
if (offset > S32_MAX) {
/* mov [rdi + dst_offset], offset */
I3(0xc7, 0x47, dst_offset);
memcpy(out, &offset, 4);
out += 4;
I3(0xc7, 0x47, dst_offset + 4);
memcpy(out, (void *) &offset + 4, 4);
out += 4;
} else {
/* mov [rdi + dst_offset], offset */
/* sign extended */
I4(0x48, 0xc7, 0x47, dst_offset);
memcpy(out, &offset, 4);
out += 4;
}
break;
case 4:
/* mov [rdi + dst_offset], offset */
I3(0xc7, 0x47, dst_offset);
memcpy(out, &offset, 4);
out += 4;
break;
default:
BUG();
}
return out;
}
bit_offset = format->key_u64s * 64;
for (i = 0; i <= field; i++)
bit_offset -= format->bits_per_field[i];
byte = bit_offset / 8;
bit_offset -= byte * 8;
*eax_zeroed = false;
if (bit_offset == 0 && bits == 8) {
/* movzx eax, BYTE PTR [rsi + imm8] */
I4(0x0f, 0xb6, 0x46, byte);
} else if (bit_offset == 0 && bits == 16) {
/* movzx eax, WORD PTR [rsi + imm8] */
I4(0x0f, 0xb7, 0x46, byte);
} else if (bit_offset + bits <= 32) {
align = min(4 - DIV_ROUND_UP(bit_offset + bits, 8), byte & 3);
byte -= align;
bit_offset += align * 8;
BUG_ON(bit_offset + bits > 32);
/* mov eax, [rsi + imm8] */
I3(0x8b, 0x46, byte);
if (bit_offset) {
/* shr eax, imm8 */
I3(0xc1, 0xe8, bit_offset);
}
if (bit_offset + bits < 32) {
unsigned mask = ~0U >> (32 - bits);
/* and eax, imm32 */
I1(0x25);
memcpy(out, &mask, 4);
out += 4;
}
} else if (bit_offset + bits <= 64) {
align = min(8 - DIV_ROUND_UP(bit_offset + bits, 8), byte & 7);
byte -= align;
bit_offset += align * 8;
BUG_ON(bit_offset + bits > 64);
/* mov rax, [rsi + imm8] */
I4(0x48, 0x8b, 0x46, byte);
shl = 64 - bit_offset - bits;
shr = bit_offset + shl;
if (shl) {
/* shl rax, imm8 */
I4(0x48, 0xc1, 0xe0, shl);
}
if (shr) {
/* shr rax, imm8 */
I4(0x48, 0xc1, 0xe8, shr);
}
} else {
align = min(4 - DIV_ROUND_UP(bit_offset + bits, 8), byte & 3);
byte -= align;
bit_offset += align * 8;
BUG_ON(bit_offset + bits > 96);
/* mov rax, [rsi + byte] */
I4(0x48, 0x8b, 0x46, byte);
/* mov edx, [rsi + byte + 8] */
I3(0x8b, 0x56, byte + 8);
/* bits from next word: */
shr = bit_offset + bits - 64;
BUG_ON(shr > bit_offset);
/* shr rax, bit_offset */
I4(0x48, 0xc1, 0xe8, shr);
/* shl rdx, imm8 */
I4(0x48, 0xc1, 0xe2, 64 - shr);
/* or rax, rdx */
I3(0x48, 0x09, 0xd0);
shr = bit_offset - shr;
if (shr) {
/* shr rax, imm8 */
I4(0x48, 0xc1, 0xe8, shr);
}
}
/* rax += offset: */
if (offset > S32_MAX) {
/* mov rdx, imm64 */
I2(0x48, 0xba);
memcpy(out, &offset, 8);
out += 8;
/* add %rdx, %rax */
I3(0x48, 0x01, 0xd0);
} else if (offset + (~0ULL >> (64 - bits)) > U32_MAX) {
/* add rax, imm32 */
I2(0x48, 0x05);
memcpy(out, &offset, 4);
out += 4;
} else if (offset) {
/* add eax, imm32 */
I1(0x05);
memcpy(out, &offset, 4);
out += 4;
}
set_field:
switch (dst_size) {
case 8:
/* mov [rdi + dst_offset], rax */
I4(0x48, 0x89, 0x47, dst_offset);
break;
case 4:
/* mov [rdi + dst_offset], eax */
I3(0x89, 0x47, dst_offset);
break;
default:
BUG();
}
return out;
}
int bch2_compile_bkey_format(const struct bkey_format *format, void *_out)
{
bool eax_zeroed = false;
u8 *out = _out;
/*
* rdi: dst - unpacked key
* rsi: src - packed key
*/
/* k->u64s, k->format, k->type */
/* mov eax, [rsi] */
I2(0x8b, 0x06);
/* add eax, BKEY_U64s - format->key_u64s */
I5(0x05, BKEY_U64s - format->key_u64s, KEY_FORMAT_CURRENT, 0, 0);
/* and eax, imm32: mask out k->pad: */
I5(0x25, 0xff, 0xff, 0xff, 0);
/* mov [rdi], eax */
I2(0x89, 0x07);
#define x(id, field) \
out = compile_bkey_field(format, out, id, \
offsetof(struct bkey, field), \
sizeof(((struct bkey *) NULL)->field), \
&eax_zeroed);
bkey_fields()
#undef x
/* retq */
I1(0xc3);
return (void *) out - _out;
}
#else
#endif
__pure
int __bch2_bkey_cmp_packed_format_checked(const struct bkey_packed *l,
const struct bkey_packed *r,
const struct btree *b)
{
return __bch2_bkey_cmp_packed_format_checked_inlined(l, r, b);
}
__pure __flatten
int __bch2_bkey_cmp_left_packed_format_checked(const struct btree *b,
const struct bkey_packed *l,
const struct bpos *r)
{
return bpos_cmp(bkey_unpack_pos_format_checked(b, l), *r);
}
__pure __flatten
int bch2_bkey_cmp_packed(const struct btree *b,
const struct bkey_packed *l,
const struct bkey_packed *r)
{
return bch2_bkey_cmp_packed_inlined(b, l, r);
}
__pure __flatten
int __bch2_bkey_cmp_left_packed(const struct btree *b,
const struct bkey_packed *l,
const struct bpos *r)
{
const struct bkey *l_unpacked;
return unlikely(l_unpacked = packed_to_bkey_c(l))
? bpos_cmp(l_unpacked->p, *r)
: __bch2_bkey_cmp_left_packed_format_checked(b, l, r);
}
void bch2_bpos_swab(struct bpos *p)
{
u8 *l = (u8 *) p;
u8 *h = ((u8 *) &p[1]) - 1;
while (l < h) {
swap(*l, *h);
l++;
--h;
}
}
void bch2_bkey_swab_key(const struct bkey_format *_f, struct bkey_packed *k)
{
const struct bkey_format *f = bkey_packed(k) ? _f : &bch2_bkey_format_current;
u8 *l = k->key_start;
u8 *h = (u8 *) ((u64 *) k->_data + f->key_u64s) - 1;
while (l < h) {
swap(*l, *h);
l++;
--h;
}
}
#ifdef CONFIG_BCACHEFS_DEBUG
void bch2_bkey_pack_test(void)
{
struct bkey t = KEY(4134ULL, 1250629070527416633ULL, 0);
struct bkey_packed p;
struct bkey_format test_format = {
.key_u64s = 3,
.nr_fields = BKEY_NR_FIELDS,
.bits_per_field = {
13,
64,
32,
},
};
struct unpack_state in_s =
unpack_state_init(&bch2_bkey_format_current, (void *) &t);
struct pack_state out_s = pack_state_init(&test_format, &p);
unsigned i;
for (i = 0; i < out_s.format->nr_fields; i++) {
u64 a, v = get_inc_field(&in_s, i);
switch (i) {
#define x(id, field) case id: a = t.field; break;
bkey_fields()
#undef x
default:
BUG();
}
if (a != v)
panic("got %llu actual %llu i %u\n", v, a, i);
if (!set_inc_field(&out_s, i, v))
panic("failed at %u\n", i);
}
BUG_ON(!bch2_bkey_pack_key(&p, &t, &test_format));
}
#endif
Codebase Browser
linux