linux/fs/nfs/nfs4session.h
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   1/* SPDX-License-Identifier: GPL-2.0 */
   2/*
   3 * fs/nfs/nfs4session.h
   4 *
   5 * Copyright (c) 2012 Trond Myklebust <Trond.Myklebust@netapp.com>
   6 *
   7 */
   8#ifndef __LINUX_FS_NFS_NFS4SESSION_H
   9#define __LINUX_FS_NFS_NFS4SESSION_H
  10
  11/* maximum number of slots to use */
  12#define NFS4_DEF_SLOT_TABLE_SIZE (64U)
  13#define NFS4_DEF_CB_SLOT_TABLE_SIZE (16U)
  14#define NFS4_MAX_SLOT_TABLE (1024U)
  15#define NFS4_NO_SLOT ((u32)-1)
  16
  17#if IS_ENABLED(CONFIG_NFS_V4)
  18
  19/* Sessions slot seqid */
  20struct nfs4_slot {
  21        struct nfs4_slot_table  *table;
  22        struct nfs4_slot        *next;
  23        unsigned long           generation;
  24        u32                     slot_nr;
  25        u32                     seq_nr;
  26        u32                     seq_nr_last_acked;
  27        u32                     seq_nr_highest_sent;
  28        unsigned int            privileged : 1,
  29                                seq_done : 1;
  30};
  31
  32/* Sessions */
  33enum nfs4_slot_tbl_state {
  34        NFS4_SLOT_TBL_DRAINING,
  35};
  36
  37#define SLOT_TABLE_SZ DIV_ROUND_UP(NFS4_MAX_SLOT_TABLE, 8*sizeof(long))
  38struct nfs4_slot_table {
  39        struct nfs4_session *session;           /* Parent session */
  40        struct nfs4_slot *slots;                /* seqid per slot */
  41        unsigned long   used_slots[SLOT_TABLE_SZ]; /* used/unused bitmap */
  42        spinlock_t      slot_tbl_lock;
  43        struct rpc_wait_queue   slot_tbl_waitq; /* allocators may wait here */
  44        wait_queue_head_t       slot_waitq;     /* Completion wait on slot */
  45        u32             max_slots;              /* # slots in table */
  46        u32             max_slotid;             /* Max allowed slotid value */
  47        u32             highest_used_slotid;    /* sent to server on each SEQ.
  48                                                 * op for dynamic resizing */
  49        u32             target_highest_slotid;  /* Server max_slot target */
  50        u32             server_highest_slotid;  /* Server highest slotid */
  51        s32             d_target_highest_slotid; /* Derivative */
  52        s32             d2_target_highest_slotid; /* 2nd derivative */
  53        unsigned long   generation;             /* Generation counter for
  54                                                   target_highest_slotid */
  55        struct completion complete;
  56        unsigned long   slot_tbl_state;
  57};
  58
  59/*
  60 * Session related parameters
  61 */
  62struct nfs4_session {
  63        struct nfs4_sessionid           sess_id;
  64        u32                             flags;
  65        unsigned long                   session_state;
  66        u32                             hash_alg;
  67        u32                             ssv_len;
  68
  69        /* The fore and back channel */
  70        struct nfs4_channel_attrs       fc_attrs;
  71        struct nfs4_slot_table          fc_slot_table;
  72        struct nfs4_channel_attrs       bc_attrs;
  73        struct nfs4_slot_table          bc_slot_table;
  74        struct nfs_client               *clp;
  75};
  76
  77enum nfs4_session_state {
  78        NFS4_SESSION_INITING,
  79        NFS4_SESSION_ESTABLISHED,
  80};
  81
  82extern int nfs4_setup_slot_table(struct nfs4_slot_table *tbl,
  83                unsigned int max_reqs, const char *queue);
  84extern void nfs4_shutdown_slot_table(struct nfs4_slot_table *tbl);
  85extern struct nfs4_slot *nfs4_alloc_slot(struct nfs4_slot_table *tbl);
  86extern struct nfs4_slot *nfs4_lookup_slot(struct nfs4_slot_table *tbl, u32 slotid);
  87extern int nfs4_slot_wait_on_seqid(struct nfs4_slot_table *tbl,
  88                u32 slotid, u32 seq_nr,
  89                unsigned long timeout);
  90extern bool nfs4_try_to_lock_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot);
  91extern void nfs4_free_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot);
  92extern void nfs4_slot_tbl_drain_complete(struct nfs4_slot_table *tbl);
  93bool nfs41_wake_and_assign_slot(struct nfs4_slot_table *tbl,
  94                struct nfs4_slot *slot);
  95void nfs41_wake_slot_table(struct nfs4_slot_table *tbl);
  96
  97static inline bool nfs4_slot_tbl_draining(struct nfs4_slot_table *tbl)
  98{
  99        return !!test_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state);
 100}
 101
 102static inline bool nfs4_test_locked_slot(const struct nfs4_slot_table *tbl,
 103                u32 slotid)
 104{
 105        return !!test_bit(slotid, tbl->used_slots);
 106}
 107
 108static inline struct nfs4_session *nfs4_get_session(const struct nfs_client *clp)
 109{
 110        return clp->cl_session;
 111}
 112
 113#if defined(CONFIG_NFS_V4_1)
 114extern void nfs41_set_target_slotid(struct nfs4_slot_table *tbl,
 115                u32 target_highest_slotid);
 116extern void nfs41_update_target_slotid(struct nfs4_slot_table *tbl,
 117                struct nfs4_slot *slot,
 118                struct nfs4_sequence_res *res);
 119
 120extern int nfs4_setup_session_slot_tables(struct nfs4_session *ses);
 121
 122extern struct nfs4_session *nfs4_alloc_session(struct nfs_client *clp);
 123extern void nfs4_destroy_session(struct nfs4_session *session);
 124extern int nfs4_init_session(struct nfs_client *clp);
 125extern int nfs4_init_ds_session(struct nfs_client *, unsigned long);
 126
 127/*
 128 * Determine if sessions are in use.
 129 */
 130static inline int nfs4_has_session(const struct nfs_client *clp)
 131{
 132        if (clp->cl_session)
 133                return 1;
 134        return 0;
 135}
 136
 137static inline int nfs4_has_persistent_session(const struct nfs_client *clp)
 138{
 139        if (nfs4_has_session(clp))
 140                return (clp->cl_session->flags & SESSION4_PERSIST);
 141        return 0;
 142}
 143
 144static inline void nfs4_copy_sessionid(struct nfs4_sessionid *dst,
 145                const struct nfs4_sessionid *src)
 146{
 147        memcpy(dst->data, src->data, NFS4_MAX_SESSIONID_LEN);
 148}
 149
 150#ifdef CONFIG_CRC32
 151/*
 152 * nfs_session_id_hash - calculate the crc32 hash for the session id
 153 * @session - pointer to session
 154 */
 155#define nfs_session_id_hash(sess_id) \
 156        (~crc32_le(0xFFFFFFFF, &(sess_id)->data[0], sizeof((sess_id)->data)))
 157#else
 158#define nfs_session_id_hash(session) (0)
 159#endif
 160#else /* defined(CONFIG_NFS_V4_1) */
 161
 162static inline int nfs4_init_session(struct nfs_client *clp)
 163{
 164        return 0;
 165}
 166
 167/*
 168 * Determine if sessions are in use.
 169 */
 170static inline int nfs4_has_session(const struct nfs_client *clp)
 171{
 172        return 0;
 173}
 174
 175static inline int nfs4_has_persistent_session(const struct nfs_client *clp)
 176{
 177        return 0;
 178}
 179
 180#define nfs_session_id_hash(session) (0)
 181
 182#endif /* defined(CONFIG_NFS_V4_1) */
 183#endif /* IS_ENABLED(CONFIG_NFS_V4) */
 184#endif /* __LINUX_FS_NFS_NFS4SESSION_H */
 185