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 (16U)
  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 */
  18 struct 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 };
  25
  26 /* Sessions */
  27 #define SLOT_TABLE_SZ DIV_ROUND_UP(NFS4_MAX_SLOT_TABLE, 8*sizeof(long))
  28 struct nfs4_slot_table {
  29         struct nfs4_session *session;           /* Parent session */
  30         struct nfs4_slot *slots;                /* seqid per slot */
  31         unsigned long   used_slots[SLOT_TABLE_SZ]; /* used/unused bitmap */
  32         spinlock_t      slot_tbl_lock;
  33         struct rpc_wait_queue   slot_tbl_waitq; /* allocators may wait here */
  34         u32             max_slots;              /* # slots in table */
  35         u32             max_slotid;             /* Max allowed slotid value */
  36         u32             highest_used_slotid;    /* sent to server on each SEQ.
  37                                                  * op for dynamic resizing */
  38         u32             target_highest_slotid;  /* Server max_slot target */
  39         u32             server_highest_slotid;  /* Server highest slotid */
  40         s32             d_target_highest_slotid; /* Derivative */
  41         s32             d2_target_highest_slotid; /* 2nd derivative */
  42         unsigned long   generation;             /* Generation counter for
  43                                                    target_highest_slotid */
  44         struct completion complete;
  45 };
  46
  47 /*
  48  * Session related parameters
  49  */
  50 struct nfs4_session {
  51         struct nfs4_sessionid           sess_id;
  52         u32                             flags;
  53         unsigned long                   session_state;
  54         u32                             hash_alg;
  55         u32                             ssv_len;
  56
  57         /* The fore and back channel */
  58         struct nfs4_channel_attrs       fc_attrs;
  59         struct nfs4_slot_table          fc_slot_table;
  60         struct nfs4_channel_attrs       bc_attrs;
  61         struct nfs4_slot_table          bc_slot_table;
  62         struct nfs_client               *clp;
  63         /* Create session arguments */
  64         unsigned int                    fc_target_max_rqst_sz;
  65         unsigned int                    fc_target_max_resp_sz;
  66 };
  67
  68 enum nfs4_session_state {
  69         NFS4_SESSION_INITING,
  70         NFS4_SESSION_DRAINING,
  71 };
  72
  73 #if defined(CONFIG_NFS_V4_1)
  74 extern struct nfs4_slot *nfs4_alloc_slot(struct nfs4_slot_table *tbl);
  75 extern void nfs4_free_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot);
  76
  77 extern void nfs41_set_target_slotid(struct nfs4_slot_table *tbl,
  78                 u32 target_highest_slotid);
  79 extern void nfs41_update_target_slotid(struct nfs4_slot_table *tbl,
  80                 struct nfs4_slot *slot,
  81                 struct nfs4_sequence_res *res);
  82
  83 extern int nfs4_setup_session_slot_tables(struct nfs4_session *ses);
  84
  85 extern struct nfs4_session *nfs4_alloc_session(struct nfs_client *clp);
  86 extern void nfs4_destroy_session(struct nfs4_session *session);
  87 extern int nfs4_init_session(struct nfs_server *server);
  88 extern int nfs4_init_ds_session(struct nfs_client *, unsigned long);
  89
  90 extern void nfs4_session_drain_complete(struct nfs4_session *session,
  91                 struct nfs4_slot_table *tbl);
  92
  93 static inline bool nfs4_session_draining(struct nfs4_session *session)
  94 {
  95         return !!test_bit(NFS4_SESSION_DRAINING, &session->session_state);
  96 }
  97
  98 bool nfs41_wake_and_assign_slot(struct nfs4_slot_table *tbl,
  99                 struct nfs4_slot *slot);
 100 void nfs41_wake_slot_table(struct nfs4_slot_table *tbl);
 101
 102 /*
 103  * Determine if sessions are in use.
 104  */
 105 static inline int nfs4_has_session(const struct nfs_client *clp)
 106 {
 107         if (clp->cl_session)
 108                 return 1;
 109         return 0;
 110 }
 111
 112 static inline int nfs4_has_persistent_session(const struct nfs_client *clp)
 113 {
 114         if (nfs4_has_session(clp))
 115                 return (clp->cl_session->flags & SESSION4_PERSIST);
 116         return 0;
 117 }
 118
 119 #else /* defined(CONFIG_NFS_V4_1) */
 120
 121 static inline int nfs4_init_session(struct nfs_server *server)
 122 {
 123         return 0;
 124 }
 125
 126 /*
 127  * Determine if sessions are in use.
 128  */
 129 static inline int nfs4_has_session(const struct nfs_client *clp)
 130 {
 131         return 0;
 132 }
 133
 134 static inline int nfs4_has_persistent_session(const struct nfs_client *clp)
 135 {
 136         return 0;
 137 }
 138
 139 #endif /* defined(CONFIG_NFS_V4_1) */
 140 #endif /* IS_ENABLED(CONFIG_NFS_V4) */
 141 #endif /* __LINUX_FS_NFS_NFS4SESSION_H */