/* 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/* How out of date a pointer gen is allowed to be: */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 u8 alloc_gc_gen(struct bch_alloc_v4 a)
{
	return a.gen - a.oldest_gen;
}

enum bucket_state {
	BUCKET_free,
	BUCKET_need_gc_gens,
	BUCKET_need_discard,
	BUCKET_cached,
	BUCKET_dirty,
};

extern const char * const bch2_bucket_states[];

static inline enum bucket_state bucket_state(struct bch_alloc_v4 a)
{
	if (a.dirty_sectors || a.stripe)
		return BUCKET_dirty;
	if (a.cached_sectors)
		return BUCKET_cached;
	BUG_ON(a.data_type);
	if (BCH_ALLOC_V4_NEED_DISCARD(&a))
		return BUCKET_need_discard;
	if (alloc_gc_gen(a) >= BUCKET_GC_GEN_MAX)
		return BUCKET_need_gc_gens;
	return BUCKET_free;
}

static inline u64 alloc_lru_idx(struct bch_alloc_v4 a)
{
	return bucket_state(a) == BUCKET_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;
}

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 *);
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);

#define ALLOC_SCAN_BATCH(ca)		max_t(size_t, 1, (ca)->mi.nbuckets >> 9)

const char *bch2_alloc_v1_invalid(const struct bch_fs *, struct bkey_s_c);
const char *bch2_alloc_v2_invalid(const struct bch_fs *, struct bkey_s_c);
const char *bch2_alloc_v3_invalid(const struct bch_fs *, struct bkey_s_c);
const char *bch2_alloc_v4_invalid(const struct bch_fs *, struct bkey_s_c k);
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 *, bool, bool);

int bch2_trans_mark_alloc(struct btree_trans *, struct bkey_s_c,
			  struct bkey_i *, unsigned);
void bch2_do_discards(struct bch_fs *);

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 */