LXR linux/fs/nfs/nfs4session.h

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