/*
 *  Copyright (c) 2001 The Regents of the University of Michigan.
 *  All rights reserved.
 *
 *  Kendrick Smith <kmsmith@umich.edu>
 *  Andy Adamson <andros@umich.edu>
 *  
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *  
 *  1. Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *  2. Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *  3. Neither the name of the University nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
 *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

#ifndef _NFSD4_STATE_H
#define _NFSD4_STATE_H

#include <linux/sunrpc/svc_xprt.h>
#include <linux/nfsd/nfsfh.h>
#include "nfsfh.h"

typedef struct {
        u32             cl_boot;
        u32             cl_id;
} clientid_t;

typedef struct {
        u32             so_boot;
        u32             so_stateownerid;
        u32             so_fileid;
} stateid_opaque_t;

typedef struct {
        u32                     si_generation;
        stateid_opaque_t        si_opaque;
} stateid_t;
#define si_boot           si_opaque.so_boot
#define si_stateownerid   si_opaque.so_stateownerid
#define si_fileid         si_opaque.so_fileid

#define STATEID_FMT     "(%08x/%08x/%08x/%08x)"
#define STATEID_VAL(s) \
        (s)->si_boot, \
        (s)->si_stateownerid, \
        (s)->si_fileid, \
        (s)->si_generation

struct nfsd4_callback {
        void *cb_op;
        struct nfs4_client *cb_clp;
        struct list_head cb_per_client;
        u32 cb_minorversion;
        struct rpc_message cb_msg;
        const struct rpc_call_ops *cb_ops;
        struct work_struct cb_work;
        bool cb_done;
};

struct nfs4_delegation {
        struct list_head        dl_perfile;
        struct list_head        dl_perclnt;
        struct list_head        dl_recall_lru;  /* delegation recalled */
        atomic_t                dl_count;       /* ref count */
        struct nfs4_client      *dl_client;
        struct nfs4_file        *dl_file;
        u32                     dl_type;
        time_t                  dl_time;
/* For recall: */
        stateid_t               dl_stateid;
        struct knfsd_fh         dl_fh;
        int                     dl_retries;
        struct nfsd4_callback   dl_recall;
};

/* client delegation callback info */
struct nfs4_cb_conn {
        /* SETCLIENTID info */
        struct sockaddr_storage cb_addr;
        struct sockaddr_storage cb_saddr;
        size_t                  cb_addrlen;
        u32                     cb_prog; /* used only in 4.0 case;
                                            per-session otherwise */
        u32                     cb_ident;       /* minorversion 0 only */
        struct svc_xprt         *cb_xprt;       /* minorversion 1 only */
};

/* Maximum number of slots per session. 160 is useful for long haul TCP */
#define NFSD_MAX_SLOTS_PER_SESSION     160
/* Maximum number of operations per session compound */
#define NFSD_MAX_OPS_PER_COMPOUND       16
/* Maximum  session per slot cache size */
#define NFSD_SLOT_CACHE_SIZE            1024
/* Maximum number of NFSD_SLOT_CACHE_SIZE slots per session */
#define NFSD_CACHE_SIZE_SLOTS_PER_SESSION       32
#define NFSD_MAX_MEM_PER_SESSION  \
                (NFSD_CACHE_SIZE_SLOTS_PER_SESSION * NFSD_SLOT_CACHE_SIZE)

struct nfsd4_slot {
        bool    sl_inuse;
        bool    sl_cachethis;
        u16     sl_opcnt;
        u32     sl_seqid;
        __be32  sl_status;
        u32     sl_datalen;
        char    sl_data[];
};

struct nfsd4_channel_attrs {
        u32             headerpadsz;
        u32             maxreq_sz;
        u32             maxresp_sz;
        u32             maxresp_cached;
        u32             maxops;
        u32             maxreqs;
        u32             nr_rdma_attrs;
        u32             rdma_attrs;
};

struct nfsd4_create_session {
        clientid_t                      clientid;
        struct nfs4_sessionid           sessionid;
        u32                             seqid;
        u32                             flags;
        struct nfsd4_channel_attrs      fore_channel;
        struct nfsd4_channel_attrs      back_channel;
        u32                             callback_prog;
        u32                             uid;
        u32                             gid;
};

struct nfsd4_bind_conn_to_session {
        struct nfs4_sessionid           sessionid;
        u32                             dir;
};

/* The single slot clientid cache structure */
struct nfsd4_clid_slot {
        u32                             sl_seqid;
        __be32                          sl_status;
        struct nfsd4_create_session     sl_cr_ses;
};

struct nfsd4_conn {
        struct list_head cn_persession;
        struct svc_xprt *cn_xprt;
        struct svc_xpt_user cn_xpt_user;
        struct nfsd4_session *cn_session;
/* CDFC4_FORE, CDFC4_BACK: */
        unsigned char cn_flags;
};

struct nfsd4_session {
        struct kref             se_ref;
        struct list_head        se_hash;        /* hash by sessionid */
        struct list_head        se_perclnt;
        u32                     se_flags;
        struct nfs4_client      *se_client;
        struct nfs4_sessionid   se_sessionid;
        struct nfsd4_channel_attrs se_fchannel;
        struct nfsd4_channel_attrs se_bchannel;
        struct list_head        se_conns;
        u32                     se_cb_prog;
        u32                     se_cb_seq_nr;
        struct nfsd4_slot       *se_slots[];    /* forward channel slots */
};

static inline void
nfsd4_put_session(struct nfsd4_session *ses)
{
        extern void free_session(struct kref *kref);
        kref_put(&ses->se_ref, free_session);
}

static inline void
nfsd4_get_session(struct nfsd4_session *ses)
{
        kref_get(&ses->se_ref);
}

/* formatted contents of nfs4_sessionid */
struct nfsd4_sessionid {
        clientid_t      clientid;
        u32             sequence;
        u32             reserved;
};

#define HEXDIR_LEN     33 /* hex version of 16 byte md5 of cl_name plus '\0' */

/*
 * struct nfs4_client - one per client.  Clientids live here.
 *      o Each nfs4_client is hashed by clientid.
 *
 *      o Each nfs4_clients is also hashed by name 
 *        (the opaque quantity initially sent by the client to identify itself).
 *        
 *      o cl_perclient list is used to ensure no dangling stateowner references
 *        when we expire the nfs4_client
 */
struct nfs4_client {
        struct list_head        cl_idhash;      /* hash by cl_clientid.id */
        struct list_head        cl_strhash;     /* hash by cl_name */
        struct list_head        cl_openowners;
        struct list_head        cl_delegations;
        struct list_head        cl_lru;         /* tail queue */
        struct xdr_netobj       cl_name;        /* id generated by client */
        char                    cl_recdir[HEXDIR_LEN]; /* recovery dir */
        nfs4_verifier           cl_verifier;    /* generated by client */
        time_t                  cl_time;        /* time of last lease renewal */
        struct sockaddr_storage cl_addr;        /* client ipaddress */
        u32                     cl_flavor;      /* setclientid pseudoflavor */
        char                    *cl_principal;  /* setclientid principal name */
        struct svc_cred         cl_cred;        /* setclientid principal */
        clientid_t              cl_clientid;    /* generated by server */
        nfs4_verifier           cl_confirm;     /* generated by server */
        u32                     cl_firststate;  /* recovery dir creation */
        u32                     cl_minorversion;

        /* for v4.0 and v4.1 callbacks: */
        struct nfs4_cb_conn     cl_cb_conn;
#define NFSD4_CLIENT_CB_UPDATE  1
#define NFSD4_CLIENT_KILL       2
        unsigned long           cl_cb_flags;
        struct rpc_clnt         *cl_cb_client;
        u32                     cl_cb_ident;
#define NFSD4_CB_UP             0
#define NFSD4_CB_UNKNOWN        1
#define NFSD4_CB_DOWN           2
        int                     cl_cb_state;
        struct nfsd4_callback   cl_cb_null;
        struct nfsd4_session    *cl_cb_session;
        struct list_head        cl_callbacks; /* list of in-progress callbacks */

        /* for all client information that callback code might need: */
        spinlock_t              cl_lock;

        /* for nfs41 */
        struct list_head        cl_sessions;
        struct nfsd4_clid_slot  cl_cs_slot;     /* create_session slot */
        u32                     cl_exchange_flags;
        /* number of rpc's in progress over an associated session: */
        atomic_t                cl_refcount;

        /* for nfs41 callbacks */
        /* We currently support a single back channel with a single slot */
        unsigned long           cl_cb_slot_busy;
        struct rpc_wait_queue   cl_cb_waitq;    /* backchannel callers may */
                                                /* wait here for slots */
};

static inline void
mark_client_expired(struct nfs4_client *clp)
{
        clp->cl_time = 0;
}

static inline bool
is_client_expired(struct nfs4_client *clp)
{
        return clp->cl_time == 0;
}

/* struct nfs4_client_reset
 * one per old client. Populates reset_str_hashtbl. Filled from conf_id_hashtbl
 * upon lease reset, or from upcall to state_daemon (to read in state
 * from non-volitile storage) upon reboot.
 */
struct nfs4_client_reclaim {
        struct list_head        cr_strhash;     /* hash by cr_name */
        char                    cr_recdir[HEXDIR_LEN]; /* recover dir */
};

static inline void
update_stateid(stateid_t *stateid)
{
        stateid->si_generation++;
}

/* A reasonable value for REPLAY_ISIZE was estimated as follows:  
 * The OPEN response, typically the largest, requires 
 *   4(status) + 8(stateid) + 20(changeinfo) + 4(rflags) +  8(verifier) + 
 *   4(deleg. type) + 8(deleg. stateid) + 4(deleg. recall flag) + 
 *   20(deleg. space limit) + ~32(deleg. ace) = 112 bytes 
 */

#define NFSD4_REPLAY_ISIZE       112 

/*
 * Replay buffer, where the result of the last seqid-mutating operation 
 * is cached. 
 */
struct nfs4_replay {
        __be32                  rp_status;
        unsigned int            rp_buflen;
        char                    *rp_buf;
        unsigned                intrp_allocated;
        struct knfsd_fh         rp_openfh;
        char                    rp_ibuf[NFSD4_REPLAY_ISIZE];
};

/*
* nfs4_stateowner can either be an open_owner, or a lock_owner
*
*    so_idhash:  stateid_hashtbl[] for open owner, lockstateid_hashtbl[]
*         for lock_owner
*    so_strhash: ownerstr_hashtbl[] for open_owner, lock_ownerstr_hashtbl[]
*         for lock_owner
*    so_perclient: nfs4_client->cl_perclient entry - used when nfs4_client
*         struct is reaped.
*    so_perfilestate: heads the list of nfs4_stateid (either open or lock) 
*         and is used to ensure no dangling nfs4_stateid references when we 
*         release a stateowner.
*    so_perlockowner: (open) nfs4_stateid->st_perlockowner entry - used when
*         close is called to reap associated byte-range locks
*    so_close_lru: (open) stateowner is placed on this list instead of being
*         reaped (when so_perfilestate is empty) to hold the last close replay.
*         reaped by laundramat thread after lease period.
*/
struct nfs4_stateowner {
        struct kref             so_ref;
        struct list_head        so_idhash;   /* hash by so_id */
        struct list_head        so_strhash;   /* hash by op_name */
        struct list_head        so_perclient;
        struct list_head        so_stateids;
        struct list_head        so_perstateid; /* for lockowners only */
        struct list_head        so_close_lru; /* tail queue */
        time_t                  so_time; /* time of placement on so_close_lru */
        int                     so_is_open_owner; /* 1=openowner,0=lockowner */
        u32                     so_id;
        struct nfs4_client *    so_client;
        /* after increment in ENCODE_SEQID_OP_TAIL, represents the next
         * sequence id expected from the client: */
        u32                     so_seqid;
        struct xdr_netobj       so_owner;     /* open owner name */
        int                     so_confirmed; /* successful OPEN_CONFIRM? */
        struct nfs4_replay      so_replay;
};

/*
*  nfs4_file: a file opened by some number of (open) nfs4_stateowners.
*    o fi_perfile list is used to search for conflicting 
*      share_acces, share_deny on the file.
*/
struct nfs4_file {
        atomic_t                fi_ref;
        struct list_head        fi_hash;    /* hash by "struct inode *" */
        struct list_head        fi_stateids;
        struct list_head        fi_delegations;
        /* One each for O_RDONLY, O_WRONLY, O_RDWR: */
        struct file *           fi_fds[3];
        /* One each for O_RDONLY, O_WRONLY: */
        atomic_t                fi_access[2];
        /*
         * Each open stateid contributes 1 to either fi_readers or
         * fi_writers, or both, depending on the open mode.  A
         * delegation also takes an fi_readers reference.  Lock
         * stateid's take none.
         */
        atomic_t                fi_readers;
        atomic_t                fi_writers;
        struct file             *fi_deleg_file;
        struct file_lock        *fi_lease;
        atomic_t                fi_delegees;
        struct inode            *fi_inode;
        u32                     fi_id;      /* used with stateowner->so_id 
                                             * for stateid_hashtbl hash */
        bool                    fi_had_conflict;
};

/* XXX: for first cut may fall back on returning file that doesn't work
 * at all? */
static inline struct file *find_writeable_file(struct nfs4_file *f)
{
        if (f->fi_fds[O_WRONLY])
                return f->fi_fds[O_WRONLY];
        return f->fi_fds[O_RDWR];
}

static inline struct file *find_readable_file(struct nfs4_file *f)
{
        if (f->fi_fds[O_RDONLY])
                return f->fi_fds[O_RDONLY];
        return f->fi_fds[O_RDWR];
}

static inline struct file *find_any_file(struct nfs4_file *f)
{
        if (f->fi_fds[O_RDWR])
                return f->fi_fds[O_RDWR];
        else if (f->fi_fds[O_WRONLY])
                return f->fi_fds[O_WRONLY];
        else
                return f->fi_fds[O_RDONLY];
}

/*
* nfs4_stateid can either be an open stateid or (eventually) a lock stateid
*
* (open)nfs4_stateid: one per (open)nfs4_stateowner, nfs4_file
*
*       st_hash: stateid_hashtbl[] entry or lockstateid_hashtbl entry
*       st_perfile: file_hashtbl[] entry.
*       st_perfile_state: nfs4_stateowner->so_perfilestate
*       st_perlockowner: (open stateid) list of lock nfs4_stateowners
*       st_access_bmap: used only for open stateid
*       st_deny_bmap: used only for open stateid
*       st_openstp: open stateid lock stateid was derived from
*
* XXX: open stateids and lock stateids have diverged sufficiently that
* we should consider defining separate structs for the two cases.
*/

struct nfs4_stateid {
        struct list_head              st_hash; 
        struct list_head              st_perfile;
        struct list_head              st_perstateowner;
        struct list_head              st_lockowners;
        struct nfs4_stateowner      * st_stateowner;
        struct nfs4_file            * st_file;
        stateid_t                     st_stateid;
        unsigned long                 st_access_bmap;
        unsigned long                 st_deny_bmap;
        struct nfs4_stateid         * st_openstp;
};

/* flags for preprocess_seqid_op() */
#define HAS_SESSION             0x00000001
#define CONFIRM                 0x00000002
#define OPEN_STATE              0x00000004
#define LOCK_STATE              0x00000008
#define RD_STATE                0x00000010
#define WR_STATE                0x00000020
#define CLOSE_STATE             0x00000040

#define seqid_mutating_err(err)                       \
        (((err) != nfserr_stale_clientid) &&    \
        ((err) != nfserr_bad_seqid) &&          \
        ((err) != nfserr_stale_stateid) &&      \
        ((err) != nfserr_bad_stateid))

struct nfsd4_compound_state;

extern __be32 nfs4_preprocess_stateid_op(struct nfsd4_compound_state *cstate,
                stateid_t *stateid, int flags, struct file **filp);
extern void nfs4_lock_state(void);
extern void nfs4_unlock_state(void);
extern int nfs4_in_grace(void);
extern __be32 nfs4_check_open_reclaim(clientid_t *clid);
extern void nfs4_free_stateowner(struct kref *kref);
extern int set_callback_cred(void);
extern void nfsd4_probe_callback(struct nfs4_client *clp);
extern void nfsd4_probe_callback_sync(struct nfs4_client *clp);
extern void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *);
extern void nfsd4_do_callback_rpc(struct work_struct *);
extern void nfsd4_cb_recall(struct nfs4_delegation *dp);
extern int nfsd4_create_callback_queue(void);
extern void nfsd4_destroy_callback_queue(void);
extern void nfsd4_shutdown_callback(struct nfs4_client *);
extern void nfs4_put_delegation(struct nfs4_delegation *dp);
extern __be32 nfs4_make_rec_clidname(char *clidname, struct xdr_netobj *clname);
extern void nfsd4_init_recdir(char *recdir_name);
extern int nfsd4_recdir_load(void);
extern void nfsd4_shutdown_recdir(void);
extern int nfs4_client_to_reclaim(const char *name);
extern int nfs4_has_reclaimed_state(const char *name, bool use_exchange_id);
extern void nfsd4_recdir_purge_old(void);
extern int nfsd4_create_clid_dir(struct nfs4_client *clp);
extern void nfsd4_remove_clid_dir(struct nfs4_client *clp);
extern void release_session_client(struct nfsd4_session *);

static inline void
nfs4_put_stateowner(struct nfs4_stateowner *so)
{
        kref_put(&so->so_ref, nfs4_free_stateowner);
}

static inline void
nfs4_get_stateowner(struct nfs4_stateowner *so)
{
        kref_get(&so->so_ref);
}

#endif   /* NFSD4_STATE_H */