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