/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _FS_CEPH_MDSMAP_H
#define _FS_CEPH_MDSMAP_H

#include <linux/bug.h>
#include <linux/ceph/types.h>

struct ceph_mds_client;

/*
 * mds map - describe servers in the mds cluster.
 *
 * we limit fields to those the client actually xcares about
 */
struct ceph_mds_info {
        u64 global_id;
        struct ceph_entity_addr addr;
        s32 state;
        int num_export_targets;
        bool laggy;
        u32 *export_targets;
};

struct ceph_mdsmap {
        u32 m_epoch, m_client_epoch, m_last_failure;
        u32 m_root;
        u32 m_session_timeout;          /* seconds */
        u32 m_session_autoclose;        /* seconds */
        u64 m_max_file_size;
        /*
         * maximum size for xattrs blob.
         * Zeroed by default to force the usage of the (sync) SETXATTR Op.
         */
        u64 m_max_xattr_size;
        u32 m_max_mds;                  /* expected up:active mds number */
        u32 m_num_active_mds;           /* actual up:active mds number */
        u32 possible_max_rank;          /* possible max rank index */
        struct ceph_mds_info *m_info;

        /* which object pools file data can be stored in */
        int m_num_data_pg_pools;
        u64 *m_data_pg_pools;
        u64 m_cas_pg_pool;

        bool m_enabled;
        bool m_damaged;
        int m_num_laggy;
        char *m_fs_name;
};

static inline struct ceph_entity_addr *
ceph_mdsmap_get_addr(struct ceph_mdsmap *m, int w)
{
        if (w >= m->possible_max_rank)
                return NULL;
        return &m->m_info[w].addr;
}

static inline int ceph_mdsmap_get_state(struct ceph_mdsmap *m, int w)
{
        BUG_ON(w < 0);
        if (w >= m->possible_max_rank)
                return CEPH_MDS_STATE_DNE;
        return m->m_info[w].state;
}

static inline bool ceph_mdsmap_is_laggy(struct ceph_mdsmap *m, int w)
{
        if (w >= 0 && w < m->possible_max_rank)
                return m->m_info[w].laggy;
        return false;
}

extern int ceph_mdsmap_get_random_mds(struct ceph_mdsmap *m);
struct ceph_mdsmap *ceph_mdsmap_decode(struct ceph_mds_client *mdsc, void **p,
                                       void *end, bool msgr2);
extern void ceph_mdsmap_destroy(struct ceph_mdsmap *m);
extern bool ceph_mdsmap_is_cluster_available(struct ceph_mdsmap *m);

#endif