linux/fs/bcachefs/alloc_background.h
Kent Overstreet a8c752bb1d bcachefs: New on disk format: Backpointers
This patch adds backpointers: we now have a reverse index from device
and offset on that device (specifically, offset within a bucket) back to
btree nodes and (non cached) data extents.

The first 40 backpointers within a bucket are stored in the alloc key;
after that backpointers spill over to the next backpointers btree. This
is to help avoid performance regressions from additional btree updates
on large streaming workloads.

This patch adds all the code for creating, checking and repairing
backpointers. The next patch in the series is going to use backpointers
for copygc - finally getting rid of the need to scan all extents to do
copygc.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:09:50 -04:00

202 lines
5.7 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _BCACHEFS_ALLOC_BACKGROUND_H
#define _BCACHEFS_ALLOC_BACKGROUND_H
#include "bcachefs.h"
#include "alloc_types.h"
#include "buckets.h"
#include "debug.h"
#include "super.h"
/* How out of date a pointer gen is allowed to be: */
#define BUCKET_GC_GEN_MAX 96U
static inline bool bch2_dev_bucket_exists(struct bch_fs *c, struct bpos pos)
{
struct bch_dev *ca;
if (!bch2_dev_exists2(c, pos.inode))
return false;
ca = bch_dev_bkey_exists(c, pos.inode);
return pos.offset >= ca->mi.first_bucket &&
pos.offset < ca->mi.nbuckets;
}
static inline u8 alloc_gc_gen(struct bch_alloc_v4 a)
{
return a.gen - a.oldest_gen;
}
static inline enum bch_data_type __alloc_data_type(u32 dirty_sectors,
u32 cached_sectors,
u32 stripe,
struct bch_alloc_v4 a,
enum bch_data_type data_type)
{
if (dirty_sectors)
return data_type;
if (stripe)
return BCH_DATA_stripe;
if (cached_sectors)
return BCH_DATA_cached;
if (BCH_ALLOC_V4_NEED_DISCARD(&a))
return BCH_DATA_need_discard;
if (alloc_gc_gen(a) >= BUCKET_GC_GEN_MAX)
return BCH_DATA_need_gc_gens;
return BCH_DATA_free;
}
static inline enum bch_data_type alloc_data_type(struct bch_alloc_v4 a,
enum bch_data_type data_type)
{
return __alloc_data_type(a.dirty_sectors, a.cached_sectors,
a.stripe, a, data_type);
}
static inline u64 alloc_lru_idx(struct bch_alloc_v4 a)
{
return a.data_type == BCH_DATA_cached ? a.io_time[READ] : 0;
}
static inline u64 alloc_freespace_genbits(struct bch_alloc_v4 a)
{
return ((u64) alloc_gc_gen(a) >> 4) << 56;
}
static inline struct bpos alloc_freespace_pos(struct bpos pos, struct bch_alloc_v4 a)
{
pos.offset |= alloc_freespace_genbits(a);
return pos;
}
static inline unsigned alloc_v4_u64s(const struct bch_alloc_v4 *a)
{
unsigned ret = (BCH_ALLOC_V4_BACKPOINTERS_START(a) ?:
BCH_ALLOC_V4_U64s_V0) +
BCH_ALLOC_V4_NR_BACKPOINTERS(a) *
(sizeof(struct bch_backpointer) / sizeof(u64));
BUG_ON(ret > U8_MAX - BKEY_U64s);
return ret;
}
static inline void set_alloc_v4_u64s(struct bkey_i_alloc_v4 *a)
{
set_bkey_val_u64s(&a->k, alloc_v4_u64s(&a->v));
}
struct bkey_i_alloc_v4 *
bch2_trans_start_alloc_update(struct btree_trans *, struct btree_iter *, struct bpos);
void __bch2_alloc_to_v4(struct bkey_s_c, struct bch_alloc_v4 *);
static inline const struct bch_alloc_v4 *bch2_alloc_to_v4(struct bkey_s_c k, struct bch_alloc_v4 *convert)
{
const struct bch_alloc_v4 *ret;
if (unlikely(k.k->type != KEY_TYPE_alloc_v4))
goto slowpath;
ret = bkey_s_c_to_alloc_v4(k).v;
if (BCH_ALLOC_V4_BACKPOINTERS_START(ret) != BCH_ALLOC_V4_U64s)
goto slowpath;
return ret;
slowpath:
__bch2_alloc_to_v4(k, convert);
return convert;
}
struct bkey_i_alloc_v4 *bch2_alloc_to_v4_mut(struct btree_trans *, struct bkey_s_c);
int bch2_bucket_io_time_reset(struct btree_trans *, unsigned, size_t, int);
int bch2_alloc_v1_invalid(const struct bch_fs *, struct bkey_s_c, int, struct printbuf *);
int bch2_alloc_v2_invalid(const struct bch_fs *, struct bkey_s_c, int, struct printbuf *);
int bch2_alloc_v3_invalid(const struct bch_fs *, struct bkey_s_c, int, struct printbuf *);
int bch2_alloc_v4_invalid(const struct bch_fs *, struct bkey_s_c, int, struct printbuf *);
void bch2_alloc_v4_swab(struct bkey_s);
void bch2_alloc_to_text(struct printbuf *, struct bch_fs *, struct bkey_s_c);
#define bch2_bkey_ops_alloc ((struct bkey_ops) { \
.key_invalid = bch2_alloc_v1_invalid, \
.val_to_text = bch2_alloc_to_text, \
.trans_trigger = bch2_trans_mark_alloc, \
.atomic_trigger = bch2_mark_alloc, \
})
#define bch2_bkey_ops_alloc_v2 ((struct bkey_ops) { \
.key_invalid = bch2_alloc_v2_invalid, \
.val_to_text = bch2_alloc_to_text, \
.trans_trigger = bch2_trans_mark_alloc, \
.atomic_trigger = bch2_mark_alloc, \
})
#define bch2_bkey_ops_alloc_v3 ((struct bkey_ops) { \
.key_invalid = bch2_alloc_v3_invalid, \
.val_to_text = bch2_alloc_to_text, \
.trans_trigger = bch2_trans_mark_alloc, \
.atomic_trigger = bch2_mark_alloc, \
})
#define bch2_bkey_ops_alloc_v4 ((struct bkey_ops) { \
.key_invalid = bch2_alloc_v4_invalid, \
.val_to_text = bch2_alloc_to_text, \
.swab = bch2_alloc_v4_swab, \
.trans_trigger = bch2_trans_mark_alloc, \
.atomic_trigger = bch2_mark_alloc, \
})
static inline bool bkey_is_alloc(const struct bkey *k)
{
return k->type == KEY_TYPE_alloc ||
k->type == KEY_TYPE_alloc_v2 ||
k->type == KEY_TYPE_alloc_v3;
}
int bch2_alloc_read(struct bch_fs *);
int bch2_trans_mark_alloc(struct btree_trans *, enum btree_id, unsigned,
struct bkey_s_c, struct bkey_i *, unsigned);
int bch2_check_alloc_info(struct bch_fs *);
int bch2_check_alloc_to_lru_refs(struct bch_fs *);
void bch2_do_discards(struct bch_fs *);
static inline u64 should_invalidate_buckets(struct bch_dev *ca,
struct bch_dev_usage u)
{
u64 want_free = ca->mi.nbuckets >> 7;
u64 free = max_t(s64, 0,
u.d[BCH_DATA_free].buckets
+ u.d[BCH_DATA_need_discard].buckets
- bch2_dev_buckets_reserved(ca, RESERVE_none));
return clamp_t(s64, want_free - free, 0, u.d[BCH_DATA_cached].buckets);
}
void bch2_do_invalidates(struct bch_fs *);
static inline struct bch_backpointer *alloc_v4_backpointers(struct bch_alloc_v4 *a)
{
return (void *) ((u64 *) &a->v +
(BCH_ALLOC_V4_BACKPOINTERS_START(a) ?:
BCH_ALLOC_V4_U64s_V0));
}
static inline const struct bch_backpointer *alloc_v4_backpointers_c(const struct bch_alloc_v4 *a)
{
return (void *) ((u64 *) &a->v + BCH_ALLOC_V4_BACKPOINTERS_START(a));
}
int bch2_fs_freespace_init(struct bch_fs *);
void bch2_recalc_capacity(struct bch_fs *);
void bch2_dev_allocator_remove(struct bch_fs *, struct bch_dev *);
void bch2_dev_allocator_add(struct bch_fs *, struct bch_dev *);
void bch2_fs_allocator_background_init(struct bch_fs *);
#endif /* _BCACHEFS_ALLOC_BACKGROUND_H */