LXR linux/fs/nfs/nfs4session.h

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