/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * per net namespace data structures for nfsd
 *
 * Copyright (C) 2012, Jeff Layton <jlayton@redhat.com>
 */

#ifndef __NFSD_NETNS_H__
#define __NFSD_NETNS_H__

#include <net/net_namespace.h>
#include <net/netns/generic.h>
#include <linux/filelock.h>
#include <linux/nfs4.h>
#include <linux/percpu_counter.h>
#include <linux/percpu-refcount.h>
#include <linux/siphash.h>
#include <linux/sunrpc/stats.h>

/* Hash tables for nfs4_clientid state */
#define CLIENT_HASH_BITS                 4
#define CLIENT_HASH_SIZE                (1 << CLIENT_HASH_BITS)
#define CLIENT_HASH_MASK                (CLIENT_HASH_SIZE - 1)

#define SESSION_HASH_SIZE       512

struct cld_net;
struct nfsd4_client_tracking_ops;

enum {
        /* cache misses due only to checksum comparison failures */
        NFSD_STATS_PAYLOAD_MISSES,
        /* amount of memory (in bytes) currently consumed by the DRC */
        NFSD_STATS_DRC_MEM_USAGE,
        NFSD_STATS_RC_HITS,             /* repcache hits */
        NFSD_STATS_RC_MISSES,           /* repcache misses */
        NFSD_STATS_RC_NOCACHE,          /* uncached reqs */
        NFSD_STATS_FH_STALE,            /* FH stale error */
        NFSD_STATS_IO_READ,             /* bytes returned to read requests */
        NFSD_STATS_IO_WRITE,            /* bytes passed in write requests */
#ifdef CONFIG_NFSD_V4
        NFSD_STATS_FIRST_NFS4_OP,       /* count of individual nfsv4 operations */
        NFSD_STATS_LAST_NFS4_OP = NFSD_STATS_FIRST_NFS4_OP + LAST_NFS4_OP,
#define NFSD_STATS_NFS4_OP(op)  (NFSD_STATS_FIRST_NFS4_OP + (op))
        NFSD_STATS_WDELEG_GETATTR,      /* count of getattr conflict with wdeleg */
#endif
        NFSD_STATS_COUNTERS_NUM
};

/*
 * Represents a nfsd "container". With respect to nfsv4 state tracking, the
 * fields of interest are the *_id_hashtbls and the *_name_tree. These track
 * the nfs4_client objects by either short or long form clientid.
 *
 * Each nfsd_net runs a nfs4_laundromat workqueue job when necessary to clean
 * up expired clients and delegations within the container.
 */
struct nfsd_net {
        struct cld_net *cld_net;

        struct cache_detail *svc_expkey_cache;
        struct cache_detail *svc_export_cache;

        struct cache_detail *idtoname_cache;
        struct cache_detail *nametoid_cache;

        struct lock_manager nfsd4_manager;
        bool grace_ended;
        bool grace_end_forced;
        time64_t boot_time;

        struct dentry *nfsd_client_dir;

        /*
         * reclaim_str_hashtbl[] holds known client info from previous reset/reboot
         * used in reboot/reset lease grace period processing
         *
         * conf_id_hashtbl[], and conf_name_tree hold confirmed
         * setclientid_confirmed info.
         *
         * unconf_str_hastbl[] and unconf_name_tree hold unconfirmed
         * setclientid info.
         */
        struct list_head *reclaim_str_hashtbl;
        int reclaim_str_hashtbl_size;
        struct list_head *conf_id_hashtbl;
        struct rb_root conf_name_tree;
        struct list_head *unconf_id_hashtbl;
        struct rb_root unconf_name_tree;
        struct list_head *sessionid_hashtbl;
        /*
         * client_lru holds client queue ordered by nfs4_client.cl_time
         * for lease renewal.
         *
         * close_lru holds (open) stateowner queue ordered by nfs4_stateowner.so_time
         * for last close replay.
         *
         * All of the above fields are protected by the client_mutex.
         */
        struct list_head client_lru;
        struct list_head close_lru;
        struct list_head del_recall_lru;

        /* protected by blocked_locks_lock */
        struct list_head blocked_locks_lru;

        struct delayed_work laundromat_work;

        /* client_lock protects the client lru list and session hash table */
        spinlock_t client_lock;

        /* protects blocked_locks_lru */
        spinlock_t blocked_locks_lock;

        struct file *rec_file;
        bool in_grace;
        const struct nfsd4_client_tracking_ops *client_tracking_ops;

        time64_t nfsd4_lease;
        time64_t nfsd4_grace;
        bool somebody_reclaimed;

        bool track_reclaim_completes;
        atomic_t nr_reclaim_complete;

        bool nfsd_net_up;
        bool lockd_up;

        seqlock_t writeverf_lock;
        unsigned char writeverf[8];

        /*
         * Minimum number of threads to run per pool.  If 0 then the
         * min == max requested number of threads.
         */
        unsigned int min_threads;

        u32 clientid_base;
        u32 clientid_counter;
        u32 clverifier_counter;

        struct svc_info nfsd_info;
#define nfsd_serv nfsd_info.serv

        struct percpu_ref nfsd_net_ref;
        struct completion nfsd_net_confirm_done;
        struct completion nfsd_net_free_done;

        /*
         * clientid and stateid data for construction of net unique COPY
         * stateids.
         */
        u32             s2s_cp_cl_id;
        struct idr      s2s_cp_stateids;
        spinlock_t      s2s_cp_lock;
        atomic_t        pending_async_copies;

        /*
         * Version information
         */
        bool nfsd_versions[NFSD_MAXVERS + 1];
        bool nfsd4_minorversions[NFSD_SUPPORTED_MINOR_VERSION + 1];

        /*
         * Duplicate reply cache
         */
        struct nfsd_drc_bucket   *drc_hashtbl;

        /* max number of entries allowed in the cache */
        unsigned int             max_drc_entries;

        /* number of significant bits in the hash value */
        unsigned int             maskbits;
        unsigned int             drc_hashsize;

        /*
         * Stats and other tracking of on the duplicate reply cache.
         * The longest_chain* fields are modified with only the per-bucket
         * cache lock, which isn't really safe and should be fixed if we want
         * these statistics to be completely accurate.
         */

        /* total number of entries */
        atomic_t                 num_drc_entries;

        /* Per-netns stats counters */
        struct percpu_counter    counter[NFSD_STATS_COUNTERS_NUM];

        /* sunrpc svc stats */
        struct svc_stat          nfsd_svcstats;

        /* longest hash chain seen */
        unsigned int             longest_chain;

        /* size of cache when we saw the longest hash chain */
        unsigned int             longest_chain_cachesize;

        struct shrinker         *nfsd_reply_cache_shrinker;

        /* tracking server-to-server copy mounts */
        spinlock_t              nfsd_ssc_lock;
        struct list_head        nfsd_ssc_mount_list;
        wait_queue_head_t       nfsd_ssc_waitq;

        /* utsname taken from the process that starts the server */
        char                    nfsd_name[UNX_MAXNODENAME+1];

        struct nfsd_fcache_disposal *fcache_disposal;

        siphash_key_t           siphash_key;

        atomic_t                nfs4_client_count;
        int                     nfs4_max_clients;

        atomic_t                nfsd_courtesy_clients;
        struct shrinker         *nfsd_client_shrinker;
        struct work_struct      nfsd_shrinker_work;

        /* last time an admin-revoke happened for NFSv4.0 */
        time64_t                nfs40_last_revoke;

#if IS_ENABLED(CONFIG_NFS_LOCALIO)
        /* Local clients to be invalidated when net is shut down */
        spinlock_t              local_clients_lock;
        struct list_head        local_clients;
#endif
};

/* Simple check to find out if a given net was properly initialized */
#define nfsd_netns_ready(nn) ((nn)->sessionid_hashtbl)

extern bool nfsd_support_version(int vers);
extern unsigned int nfsd_net_id;

bool nfsd_net_try_get(struct net *net);
void nfsd_net_put(struct net *net);

void nfsd_copy_write_verifier(__be32 verf[2], struct nfsd_net *nn);
void nfsd_reset_write_verifier(struct nfsd_net *nn);
#endif /* __NFSD_NETNS_H__ */