/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Copyright (c) 2018 Red Hat, Inc.
 * All rights reserved.
 */

#ifndef __LIBXFS_AG_H
#define __LIBXFS_AG_H 1

#include "xfs_group.h"

struct xfs_mount;
struct xfs_trans;
struct xfs_perag;

/*
 * Per-ag infrastructure
 */

/* per-AG block reservation data structures*/
struct xfs_ag_resv {
        /* number of blocks originally reserved here */
        xfs_extlen_t                    ar_orig_reserved;
        /* number of blocks reserved here */
        xfs_extlen_t                    ar_reserved;
        /* number of blocks originally asked for */
        xfs_extlen_t                    ar_asked;
};

/*
 * Per-ag incore structure, copies of information in agf and agi, to improve the
 * performance of allocation group selection.
 */
struct xfs_perag {
        struct xfs_group pag_group;
        unsigned long   pag_opstate;
        uint8_t         pagf_bno_level; /* # of levels in bno btree */
        uint8_t         pagf_cnt_level; /* # of levels in cnt btree */
        uint8_t         pagf_rmap_level;/* # of levels in rmap btree */
        uint32_t        pagf_flcount;   /* count of blocks in freelist */
        xfs_extlen_t    pagf_freeblks;  /* total free blocks */
        xfs_extlen_t    pagf_longest;   /* longest free space */
        uint32_t        pagf_btreeblks; /* # of blocks held in AGF btrees */
        xfs_agino_t     pagi_freecount; /* number of free inodes */
        xfs_agino_t     pagi_count;     /* number of allocated inodes */

        /*
         * Inode allocation search lookup optimisation.
         * If the pagino matches, the search for new inodes
         * doesn't need to search the near ones again straight away
         */
        xfs_agino_t     pagl_pagino;
        xfs_agino_t     pagl_leftrec;
        xfs_agino_t     pagl_rightrec;

        uint8_t         pagf_refcount_level; /* recount btree height */

        /* Blocks reserved for all kinds of metadata. */
        struct xfs_ag_resv      pag_meta_resv;
        /* Blocks reserved for the reverse mapping btree. */
        struct xfs_ag_resv      pag_rmapbt_resv;

        /* Precalculated geometry info */
        xfs_agino_t             agino_min;
        xfs_agino_t             agino_max;

#ifdef __KERNEL__
        /* -- kernel only structures below this line -- */

#ifdef CONFIG_XFS_ONLINE_REPAIR
        /*
         * Alternate btree heights so that online repair won't trip the write
         * verifiers while rebuilding the AG btrees.
         */
        uint8_t         pagf_repair_bno_level;
        uint8_t         pagf_repair_cnt_level;
        uint8_t         pagf_repair_refcount_level;
        uint8_t         pagf_repair_rmap_level;
#endif

        atomic_t        pagf_fstrms;    /* # of filestreams active in this AG */

        spinlock_t      pag_ici_lock;   /* incore inode cache lock */
        struct radix_tree_root pag_ici_root;    /* incore inode cache root */
        int             pag_ici_reclaimable;    /* reclaimable inodes */
        unsigned long   pag_ici_reclaim_cursor; /* reclaim restart point */

        struct xfs_buf_cache    pag_bcache;

        /* background prealloc block trimming */
        struct delayed_work     pag_blockgc_work;
#endif /* __KERNEL__ */
};

static inline struct xfs_perag *to_perag(struct xfs_group *xg)
{
        return container_of(xg, struct xfs_perag, pag_group);
}

static inline struct xfs_group *pag_group(struct xfs_perag *pag)
{
        return &pag->pag_group;
}

static inline struct xfs_mount *pag_mount(const struct xfs_perag *pag)
{
        return pag->pag_group.xg_mount;
}

static inline xfs_agnumber_t pag_agno(const struct xfs_perag *pag)
{
        return pag->pag_group.xg_gno;
}

/*
 * Per-AG operational state. These are atomic flag bits.
 */
#define XFS_AGSTATE_AGF_INIT            0
#define XFS_AGSTATE_AGI_INIT            1
#define XFS_AGSTATE_PREFERS_METADATA    2
#define XFS_AGSTATE_ALLOWS_INODES       3
#define XFS_AGSTATE_AGFL_NEEDS_RESET    4

#define __XFS_AG_OPSTATE(name, NAME) \
static inline bool xfs_perag_ ## name (struct xfs_perag *pag) \
{ \
        return test_bit(XFS_AGSTATE_ ## NAME, &pag->pag_opstate); \
}

__XFS_AG_OPSTATE(initialised_agf, AGF_INIT)
__XFS_AG_OPSTATE(initialised_agi, AGI_INIT)
__XFS_AG_OPSTATE(prefers_metadata, PREFERS_METADATA)
__XFS_AG_OPSTATE(allows_inodes, ALLOWS_INODES)
__XFS_AG_OPSTATE(agfl_needs_reset, AGFL_NEEDS_RESET)

int xfs_initialize_perag(struct xfs_mount *mp, xfs_agnumber_t orig_agcount,
                xfs_agnumber_t new_agcount, xfs_rfsblock_t dcount,
                xfs_agnumber_t *maxagi);
void xfs_free_perag_range(struct xfs_mount *mp, xfs_agnumber_t first_agno,
                xfs_agnumber_t end_agno);
int xfs_initialize_perag_data(struct xfs_mount *mp, xfs_agnumber_t agno);
int xfs_update_last_ag_size(struct xfs_mount *mp, xfs_agnumber_t prev_agcount);

/* Passive AG references */
static inline struct xfs_perag *
xfs_perag_get(
        struct xfs_mount        *mp,
        xfs_agnumber_t          agno)
{
        return to_perag(xfs_group_get(mp, agno, XG_TYPE_AG));
}

static inline struct xfs_perag *
xfs_perag_hold(
        struct xfs_perag        *pag)
{
        return to_perag(xfs_group_hold(pag_group(pag)));
}

static inline void
xfs_perag_put(
        struct xfs_perag        *pag)
{
        xfs_group_put(pag_group(pag));
}

/* Active AG references */
static inline struct xfs_perag *
xfs_perag_grab(
        struct xfs_mount        *mp,
        xfs_agnumber_t          agno)
{
        return to_perag(xfs_group_grab(mp, agno, XG_TYPE_AG));
}

static inline void
xfs_perag_rele(
        struct xfs_perag        *pag)
{
        xfs_group_rele(pag_group(pag));
}

static inline struct xfs_perag *
xfs_perag_next_range(
        struct xfs_mount        *mp,
        struct xfs_perag        *pag,
        xfs_agnumber_t          start_agno,
        xfs_agnumber_t          end_agno)
{
        return to_perag(xfs_group_next_range(mp, pag ? pag_group(pag) : NULL,
                        start_agno, end_agno, XG_TYPE_AG));
}

static inline struct xfs_perag *
xfs_perag_next_from(
        struct xfs_mount        *mp,
        struct xfs_perag        *pag,
        xfs_agnumber_t          start_agno)
{
        return xfs_perag_next_range(mp, pag, start_agno, mp->m_sb.sb_agcount - 1);
}

static inline struct xfs_perag *
xfs_perag_next(
        struct xfs_mount        *mp,
        struct xfs_perag        *pag)
{
        return xfs_perag_next_from(mp, pag, 0);
}

/*
 * Per-ag geometry infomation and validation
 */
xfs_agblock_t xfs_ag_block_count(struct xfs_mount *mp, xfs_agnumber_t agno);
void xfs_agino_range(struct xfs_mount *mp, xfs_agnumber_t agno,
                xfs_agino_t *first, xfs_agino_t *last);

static inline bool
xfs_verify_agbno(struct xfs_perag *pag, xfs_agblock_t agbno)
{
        return xfs_verify_gbno(pag_group(pag), agbno);
}

static inline bool
xfs_verify_agbext(
        struct xfs_perag        *pag,
        xfs_agblock_t           agbno,
        xfs_agblock_t           len)
{
        return xfs_verify_gbext(pag_group(pag), agbno, len);
}

/*
 * Verify that an AG inode number pointer neither points outside the AG
 * nor points at static metadata.
 */
static inline bool
xfs_verify_agino(struct xfs_perag *pag, xfs_agino_t agino)
{
        if (agino < pag->agino_min)
                return false;
        if (agino > pag->agino_max)
                return false;
        return true;
}

/*
 * Verify that an AG inode number pointer neither points outside the AG
 * nor points at static metadata, or is NULLAGINO.
 */
static inline bool
xfs_verify_agino_or_null(struct xfs_perag *pag, xfs_agino_t agino)
{
        if (agino == NULLAGINO)
                return true;
        return xfs_verify_agino(pag, agino);
}

static inline bool
xfs_ag_contains_log(struct xfs_mount *mp, xfs_agnumber_t agno)
{
        return mp->m_sb.sb_logstart > 0 &&
               agno == XFS_FSB_TO_AGNO(mp, mp->m_sb.sb_logstart);
}

static inline struct xfs_perag *
xfs_perag_next_wrap(
        struct xfs_perag        *pag,
        xfs_agnumber_t          *agno,
        xfs_agnumber_t          stop_agno,
        xfs_agnumber_t          restart_agno,
        xfs_agnumber_t          wrap_agno)
{
        struct xfs_mount        *mp = pag_mount(pag);

        *agno = pag_agno(pag) + 1;
        xfs_perag_rele(pag);
        while (*agno != stop_agno) {
                if (*agno >= wrap_agno) {
                        if (restart_agno >= stop_agno)
                                break;
                        *agno = restart_agno;
                }

                pag = xfs_perag_grab(mp, *agno);
                if (pag)
                        return pag;
                (*agno)++;
        }
        return NULL;
}

/*
 * Iterate all AGs from start_agno through wrap_agno, then restart_agno through
 * (start_agno - 1).
 */
#define for_each_perag_wrap_range(mp, start_agno, restart_agno, wrap_agno, agno, pag) \
        for ((agno) = (start_agno), (pag) = xfs_perag_grab((mp), (agno)); \
                (pag) != NULL; \
                (pag) = xfs_perag_next_wrap((pag), &(agno), (start_agno), \
                                (restart_agno), (wrap_agno)))
/*
 * Iterate all AGs from start_agno through wrap_agno, then 0 through
 * (start_agno - 1).
 */
#define for_each_perag_wrap_at(mp, start_agno, wrap_agno, agno, pag) \
        for_each_perag_wrap_range((mp), (start_agno), 0, (wrap_agno), (agno), (pag))

/*
 * Iterate all AGs from start_agno through to the end of the filesystem, then 0
 * through (start_agno - 1).
 */
#define for_each_perag_wrap(mp, start_agno, agno, pag) \
        for_each_perag_wrap_at((mp), (start_agno), (mp)->m_sb.sb_agcount, \
                                (agno), (pag))


struct aghdr_init_data {
        /* per ag data */
        xfs_agblock_t           agno;           /* ag to init */
        xfs_extlen_t            agsize;         /* new AG size */
        struct list_head        buffer_list;    /* buffer writeback list */
        xfs_rfsblock_t          nfree;          /* cumulative new free space */

        /* per header data */
        xfs_daddr_t             daddr;          /* header location */
        size_t                  numblks;        /* size of header */
        const struct xfs_btree_ops *bc_ops;     /* btree ops */
};

int xfs_ag_init_headers(struct xfs_mount *mp, struct aghdr_init_data *id);
int xfs_ag_shrink_space(struct xfs_perag *pag, struct xfs_trans **tpp,
                        xfs_extlen_t delta);
void
xfs_growfs_compute_deltas(struct xfs_mount *mp, xfs_rfsblock_t nb,
                        int64_t *deltap, xfs_agnumber_t *nagcountp);
int xfs_ag_extend_space(struct xfs_perag *pag, struct xfs_trans *tp,
                        xfs_extlen_t len);
int xfs_ag_get_geometry(struct xfs_perag *pag, struct xfs_ag_geometry *ageo);

static inline xfs_fsblock_t
xfs_agbno_to_fsb(
        struct xfs_perag        *pag,
        xfs_agblock_t           agbno)
{
        return XFS_AGB_TO_FSB(pag_mount(pag), pag_agno(pag), agbno);
}

static inline xfs_daddr_t
xfs_agbno_to_daddr(
        struct xfs_perag        *pag,
        xfs_agblock_t           agbno)
{
        return XFS_AGB_TO_DADDR(pag_mount(pag), pag_agno(pag), agbno);
}

static inline xfs_ino_t
xfs_agino_to_ino(
        struct xfs_perag        *pag,
        xfs_agino_t             agino)
{
        return XFS_AGINO_TO_INO(pag_mount(pag), pag_agno(pag), agino);
}

#endif /* __LIBXFS_AG_H */