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