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};
  74
  75extern int nfs4_setup_slot_table(struct nfs4_slot_table *tbl,
  76                unsigned int max_reqs, const char *queue);
  77extern void nfs4_release_slot_table(struct nfs4_slot_table *tbl);
  78extern struct nfs4_slot *nfs4_alloc_slot(struct nfs4_slot_table *tbl);
  79extern void nfs4_free_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot);
  80extern void nfs4_slot_tbl_drain_complete(struct nfs4_slot_table *tbl);
  81bool nfs41_wake_and_assign_slot(struct nfs4_slot_table *tbl,
  82                struct nfs4_slot *slot);
  83void nfs41_wake_slot_table(struct nfs4_slot_table *tbl);
  84
  85static inline bool nfs4_slot_tbl_draining(struct nfs4_slot_table *tbl)
  86{
  87        return !!test_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state);
  88}
  89
  90#if defined(CONFIG_NFS_V4_1)
  91extern void nfs41_set_target_slotid(struct nfs4_slot_table *tbl,
  92                u32 target_highest_slotid);
  93extern void nfs41_update_target_slotid(struct nfs4_slot_table *tbl,
  94                struct nfs4_slot *slot,
  95                struct nfs4_sequence_res *res);
  96
  97extern int nfs4_setup_session_slot_tables(struct nfs4_session *ses);
  98
  99extern struct nfs4_session *nfs4_alloc_session(struct nfs_client *clp);
 100extern void nfs4_destroy_session(struct nfs4_session *session);
 101extern int nfs4_init_session(struct nfs_client *clp);
 102extern int nfs4_init_ds_session(struct nfs_client *, unsigned long);
 103
 104/*
 105 * Determine if sessions are in use.
 106 */
 107static inline int nfs4_has_session(const struct nfs_client *clp)
 108{
 109        if (clp->cl_session)
 110                return 1;
 111        return 0;
 112}
 113
 114static inline int nfs4_has_persistent_session(const struct nfs_client *clp)
 115{
 116        if (nfs4_has_session(clp))
 117                return (clp->cl_session->flags & SESSION4_PERSIST);
 118        return 0;
 119}
 120
 121#ifdef CONFIG_CRC32
 122/*
 123 * nfs_session_id_hash - calculate the crc32 hash for the session id
 124 * @session - pointer to session
 125 */
 126#define nfs_session_id_hash(sess_id) \
 127        (~crc32_le(0xFFFFFFFF, &(sess_id)->data[0], sizeof((sess_id)->data)))
 128#else
 129#define nfs_session_id_hash(session) (0)
 130#endif
 131#else /* defined(CONFIG_NFS_V4_1) */
 132
 133static inline int nfs4_init_session(struct nfs_client *clp)
 134{
 135        return 0;
 136}
 137
 138/*
 139 * Determine if sessions are in use.
 140 */
 141static inline int nfs4_has_session(const struct nfs_client *clp)
 142{
 143        return 0;
 144}
 145
 146static inline int nfs4_has_persistent_session(const struct nfs_client *clp)
 147{
 148        return 0;
 149}
 150
 151#endif /* defined(CONFIG_NFS_V4_1) */
 152#endif /* IS_ENABLED(CONFIG_NFS_V4) */
 153#endif /* __LINUX_FS_NFS_NFS4SESSION_H */
 154