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         unsigned int            interrupted : 1;
  25 };
  26
  27 /* Sessions */
  28 enum 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))
  33 struct 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  */
  56 struct 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         /* Create session arguments */
  70         unsigned int                    fc_target_max_rqst_sz;
  71         unsigned int                    fc_target_max_resp_sz;
  72 };
  73
  74 enum nfs4_session_state {
  75         NFS4_SESSION_INITING,
  76 };
  77
  78 #if defined(CONFIG_NFS_V4_1)
  79 extern struct nfs4_slot *nfs4_alloc_slot(struct nfs4_slot_table *tbl);
  80 extern void nfs4_free_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot);
  81
  82 extern void nfs41_set_target_slotid(struct nfs4_slot_table *tbl,
  83                 u32 target_highest_slotid);
  84 extern void nfs41_update_target_slotid(struct nfs4_slot_table *tbl,
  85                 struct nfs4_slot *slot,
  86                 struct nfs4_sequence_res *res);
  87
  88 extern int nfs4_setup_session_slot_tables(struct nfs4_session *ses);
  89
  90 extern struct nfs4_session *nfs4_alloc_session(struct nfs_client *clp);
  91 extern void nfs4_destroy_session(struct nfs4_session *session);
  92 extern int nfs4_init_session(struct nfs_server *server);
  93 extern int nfs4_init_ds_session(struct nfs_client *, unsigned long);
  94
  95 extern void nfs4_slot_tbl_drain_complete(struct nfs4_slot_table *tbl);
  96
  97 static inline bool nfs4_slot_tbl_draining(struct nfs4_slot_table *tbl)
  98 {
  99         return !!test_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state);
 100 }
 101
 102 bool nfs41_wake_and_assign_slot(struct nfs4_slot_table *tbl,
 103                 struct nfs4_slot *slot);
 104 void nfs41_wake_slot_table(struct nfs4_slot_table *tbl);
 105
 106 /*
 107  * Determine if sessions are in use.
 108  */
 109 static inline int nfs4_has_session(const struct nfs_client *clp)
 110 {
 111         if (clp->cl_session)
 112                 return 1;
 113         return 0;
 114 }
 115
 116 static inline int nfs4_has_persistent_session(const struct nfs_client *clp)
 117 {
 118         if (nfs4_has_session(clp))
 119                 return (clp->cl_session->flags & SESSION4_PERSIST);
 120         return 0;
 121 }
 122
 123 #else /* defined(CONFIG_NFS_V4_1) */
 124
 125 static inline int nfs4_init_session(struct nfs_server *server)
 126 {
 127         return 0;
 128 }
 129
 130 /*
 131  * Determine if sessions are in use.
 132  */
 133 static inline int nfs4_has_session(const struct nfs_client *clp)
 134 {
 135         return 0;
 136 }
 137
 138 static inline int nfs4_has_persistent_session(const struct nfs_client *clp)
 139 {
 140         return 0;
 141 }
 142
 143 #endif /* defined(CONFIG_NFS_V4_1) */
 144 #endif /* IS_ENABLED(CONFIG_NFS_V4) */
 145 #endif /* __LINUX_FS_NFS_NFS4SESSION_H */