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