/* SPDX-License-Identifier: GPL-2.0 */

#ifndef BTRFS_BLOCK_RSV_H
#define BTRFS_BLOCK_RSV_H

#include <linux/types.h>
#include <linux/compiler.h>
#include <linux/spinlock.h>

struct btrfs_trans_handle;
struct btrfs_root;
struct btrfs_space_info;
struct btrfs_block_rsv;
struct btrfs_fs_info;
enum btrfs_reserve_flush_enum;

/*
 * Types of block reserves
 */
enum btrfs_rsv_type {
        BTRFS_BLOCK_RSV_GLOBAL,
        BTRFS_BLOCK_RSV_DELALLOC,
        BTRFS_BLOCK_RSV_TRANS,
        BTRFS_BLOCK_RSV_CHUNK,
        BTRFS_BLOCK_RSV_REMAP,
        BTRFS_BLOCK_RSV_DELOPS,
        BTRFS_BLOCK_RSV_DELREFS,
        BTRFS_BLOCK_RSV_TREELOG,
        BTRFS_BLOCK_RSV_EMPTY,
        BTRFS_BLOCK_RSV_TEMP,
};

struct btrfs_block_rsv {
        u64 size;
        u64 reserved;
        struct btrfs_space_info *space_info;
        spinlock_t lock;
        bool full;
        bool failfast;
        /* Block reserve type, one of BTRFS_BLOCK_RSV_* */
        enum btrfs_rsv_type type:8;

        /*
         * Qgroup equivalent for @size @reserved
         *
         * Unlike normal @size/@reserved for inode rsv, qgroup doesn't care
         * about things like csum size nor how many tree blocks it will need to
         * reserve.
         *
         * Qgroup cares more about net change of the extent usage.
         *
         * So for one newly inserted file extent, in worst case it will cause
         * leaf split and level increase, nodesize for each file extent is
         * already too much.
         *
         * In short, qgroup_size/reserved is the upper limit of possible needed
         * qgroup metadata reservation.
         */
        u64 qgroup_rsv_size;
        u64 qgroup_rsv_reserved;
};

void btrfs_init_block_rsv(struct btrfs_block_rsv *rsv, enum btrfs_rsv_type type);
void btrfs_init_root_block_rsv(struct btrfs_root *root);
struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_fs_info *fs_info,
                                              enum btrfs_rsv_type type);
void btrfs_init_metadata_block_rsv(struct btrfs_fs_info *fs_info,
                                   struct btrfs_block_rsv *rsv,
                                   enum btrfs_rsv_type type);
void btrfs_free_block_rsv(struct btrfs_fs_info *fs_info,
                          struct btrfs_block_rsv *rsv);
int btrfs_block_rsv_add(struct btrfs_fs_info *fs_info,
                        struct btrfs_block_rsv *block_rsv, u64 num_bytes,
                        enum btrfs_reserve_flush_enum flush);
int btrfs_block_rsv_check(struct btrfs_block_rsv *block_rsv, int min_percent);
int btrfs_block_rsv_refill(struct btrfs_fs_info *fs_info,
                           struct btrfs_block_rsv *block_rsv, u64 num_bytes,
                           enum btrfs_reserve_flush_enum flush);
int btrfs_block_rsv_migrate(struct btrfs_block_rsv *src_rsv,
                            struct btrfs_block_rsv *dst_rsv, u64 num_bytes,
                            bool update_size);
int btrfs_block_rsv_use_bytes(struct btrfs_block_rsv *block_rsv, u64 num_bytes);
void btrfs_block_rsv_add_bytes(struct btrfs_block_rsv *block_rsv,
                               u64 num_bytes, bool update_size);
u64 btrfs_block_rsv_release(struct btrfs_fs_info *fs_info,
                              struct btrfs_block_rsv *block_rsv,
                              u64 num_bytes, u64 *qgroup_to_release);
void btrfs_update_global_block_rsv(struct btrfs_fs_info *fs_info);
void btrfs_init_global_block_rsv(struct btrfs_fs_info *fs_info);
void btrfs_release_global_block_rsv(struct btrfs_fs_info *fs_info);
struct btrfs_block_rsv *btrfs_use_block_rsv(struct btrfs_trans_handle *trans,
                                            struct btrfs_root *root,
                                            u32 blocksize);
int btrfs_check_trunc_cache_free_space(const struct btrfs_fs_info *fs_info,
                                       struct btrfs_block_rsv *rsv);
static inline void btrfs_unuse_block_rsv(struct btrfs_fs_info *fs_info,
                                         struct btrfs_block_rsv *block_rsv,
                                         u32 blocksize)
{
        btrfs_block_rsv_add_bytes(block_rsv, blocksize, false);
        btrfs_block_rsv_release(fs_info, block_rsv, 0, NULL);
}

/*
 * Fast path to check if the reserve is full, may be carefully used outside of
 * locks.
 */
static inline bool btrfs_block_rsv_full(const struct btrfs_block_rsv *rsv)
{
        return data_race(rsv->full);
}

/*
 * Get the reserved mount of a block reserve in a context where getting a stale
 * value is acceptable, instead of accessing it directly and trigger data race
 * warning from KCSAN.
 */
static inline u64 btrfs_block_rsv_reserved(struct btrfs_block_rsv *rsv)
{
        u64 ret;

        spin_lock(&rsv->lock);
        ret = rsv->reserved;
        spin_unlock(&rsv->lock);

        return ret;
}

/*
 * Get the size of a block reserve in a context where getting a stale value is
 * acceptable, instead of accessing it directly and trigger data race warning
 * from KCSAN.
 */
static inline u64 btrfs_block_rsv_size(struct btrfs_block_rsv *rsv)
{
        u64 ret;

        spin_lock(&rsv->lock);
        ret = rsv->size;
        spin_unlock(&rsv->lock);

        return ret;
}

#endif /* BTRFS_BLOCK_RSV_H */