// SPDX-License-Identifier: GPL-2.0

#include "bcachefs.h"
#include "alloc_background.h"
#include "btree_iter.h"
#include "btree_update.h"
#include "error.h"
#include "lru.h"
#include "recovery.h"

/* KEY_TYPE_lru is obsolete: */
int bch2_lru_invalid(const struct bch_fs *c, struct bkey_s_c k,
		     unsigned flags, struct printbuf *err)
{
	const struct bch_lru *lru = bkey_s_c_to_lru(k).v;

	if (bkey_val_bytes(k.k) < sizeof(*lru)) {
		prt_printf(err, "incorrect value size (%zu < %zu)",
		       bkey_val_bytes(k.k), sizeof(*lru));
		return -BCH_ERR_invalid_bkey;
	}

	if (!lru_pos_time(k.k->p)) {
		prt_printf(err, "lru entry at time=0");
		return -BCH_ERR_invalid_bkey;

	}

	return 0;
}

void bch2_lru_to_text(struct printbuf *out, struct bch_fs *c,
		      struct bkey_s_c k)
{
	const struct bch_lru *lru = bkey_s_c_to_lru(k).v;

	prt_printf(out, "idx %llu", le64_to_cpu(lru->idx));
}

static int __bch2_lru_set(struct btree_trans *trans, u16 lru_id,
			u64 dev_bucket, u64 time, unsigned key_type)
{
	struct btree_iter iter;
	struct bkey_i *k;
	int ret = 0;

	if (!time)
		return 0;

	k = bch2_trans_kmalloc_nomemzero(trans, sizeof(*k));
	ret = PTR_ERR_OR_ZERO(k);
	if (unlikely(ret))
		return ret;

	bkey_init(&k->k);
	k->k.type = key_type;
	k->k.p = lru_pos(lru_id, dev_bucket, time);

	EBUG_ON(lru_pos_id(k->k.p) != lru_id);
	EBUG_ON(lru_pos_time(k->k.p) != time);
	EBUG_ON(k->k.p.offset != dev_bucket);

	bch2_trans_iter_init(trans, &iter, BTREE_ID_lru,
			     k->k.p, BTREE_ITER_INTENT);

	ret = bch2_btree_iter_traverse(&iter) ?:
		bch2_trans_update(trans, &iter, k, 0);
	bch2_trans_iter_exit(trans, &iter);
	return ret;
}

int bch2_lru_del(struct btree_trans *trans, u16 lru_id, u64 dev_bucket, u64 time)
{
	return __bch2_lru_set(trans, lru_id, dev_bucket, time, KEY_TYPE_deleted);
}

int bch2_lru_set(struct btree_trans *trans, u16 lru_id, u64 dev_bucket, u64 time)
{
	return __bch2_lru_set(trans, lru_id, dev_bucket, time, KEY_TYPE_set);
}

int bch2_lru_change(struct btree_trans *trans,
		    u16 lru_id, u64 dev_bucket,
		    u64 old_time, u64 new_time)
{
	if (old_time == new_time)
		return 0;

	return  bch2_lru_del(trans, lru_id, dev_bucket, old_time) ?:
		bch2_lru_set(trans, lru_id, dev_bucket, new_time);
}

static int bch2_check_lru_key(struct btree_trans *trans,
			      struct btree_iter *lru_iter,
			      struct bkey_s_c lru_k)
{
	struct bch_fs *c = trans->c;
	struct btree_iter iter;
	struct bkey_s_c k;
	struct bch_alloc_v4 a_convert;
	const struct bch_alloc_v4 *a;
	struct printbuf buf1 = PRINTBUF;
	struct printbuf buf2 = PRINTBUF;
	struct bpos alloc_pos = u64_to_bucket(lru_k.k->p.offset);
	int ret;

	if (fsck_err_on(!bch2_dev_bucket_exists(c, alloc_pos), c,
			"lru key points to nonexistent device:bucket %llu:%llu",
			alloc_pos.inode, alloc_pos.offset))
		return bch2_btree_delete_at(trans, lru_iter, 0);

	bch2_trans_iter_init(trans, &iter, BTREE_ID_alloc, alloc_pos, 0);
	k = bch2_btree_iter_peek_slot(&iter);
	ret = bkey_err(k);
	if (ret)
		goto err;

	a = bch2_alloc_to_v4(k, &a_convert);

	if (fsck_err_on(lru_k.k->type != KEY_TYPE_set ||
			a->data_type != BCH_DATA_cached ||
			a->io_time[READ] != lru_pos_time(lru_k.k->p), c,
			"incorrect lru entry (time %llu) %s\n"
			"  for %s",
			lru_pos_time(lru_k.k->p),
			(bch2_bkey_val_to_text(&buf1, c, lru_k), buf1.buf),
			(bch2_bkey_val_to_text(&buf2, c, k), buf2.buf))) {
		ret = bch2_btree_delete_at(trans, lru_iter, 0);
		if (ret)
			goto err;
	}
err:
fsck_err:
	bch2_trans_iter_exit(trans, &iter);
	printbuf_exit(&buf2);
	printbuf_exit(&buf1);
	return ret;
}

int bch2_check_lrus(struct bch_fs *c)
{
	struct btree_trans trans;
	struct btree_iter iter;
	struct bkey_s_c k;
	int ret = 0;

	bch2_trans_init(&trans, c, 0, 0);

	ret = for_each_btree_key_commit(&trans, iter,
			BTREE_ID_lru, POS_MIN, BTREE_ITER_PREFETCH, k,
			NULL, NULL, BTREE_INSERT_NOFAIL|BTREE_INSERT_LAZY_RW,
		bch2_check_lru_key(&trans, &iter, k));

	bch2_trans_exit(&trans);
	return ret;

}