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 */
  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 extern int nfs4_setup_slot_table(struct nfs4_slot_table *tbl,
  76                 unsigned int max_reqs, const char *queue);
  77 extern void nfs4_shutdown_slot_table(struct nfs4_slot_table *tbl);
  78 extern struct nfs4_slot *nfs4_alloc_slot(struct nfs4_slot_table *tbl);
  79 extern void nfs4_free_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot);
  80 extern void nfs4_slot_tbl_drain_complete(struct nfs4_slot_table *tbl);
  81 bool nfs41_wake_and_assign_slot(struct nfs4_slot_table *tbl,
  82                 struct nfs4_slot *slot);
  83 void nfs41_wake_slot_table(struct nfs4_slot_table *tbl);
  84
  85 static 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)
  91 extern void nfs41_set_target_slotid(struct nfs4_slot_table *tbl,
  92                 u32 target_highest_slotid);
  93 extern void nfs41_update_target_slotid(struct nfs4_slot_table *tbl,
  94                 struct nfs4_slot *slot,
  95                 struct nfs4_sequence_res *res);
  96
  97 extern int nfs4_setup_session_slot_tables(struct nfs4_session *ses);
  98
  99 extern struct nfs4_session *nfs4_alloc_session(struct nfs_client *clp);
 100 extern void nfs4_destroy_session(struct nfs4_session *session);
 101 extern int nfs4_init_session(struct nfs_client *clp);
 102 extern int nfs4_init_ds_session(struct nfs_client *, unsigned long);
 103
 104 /*
 105  * Determine if sessions are in use.
 106  */
 107 static inline int nfs4_has_session(const struct nfs_client *clp)
 108 {
 109         if (clp->cl_session)
 110                 return 1;
 111         return 0;
 112 }
 113
 114 static 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 static inline void nfs4_copy_sessionid(struct nfs4_sessionid *dst,
 122                 const struct nfs4_sessionid *src)
 123 {
 124         memcpy(dst->data, src->data, NFS4_MAX_SESSIONID_LEN);
 125 }
 126
 127 #ifdef CONFIG_CRC32
 128 /*
 129  * nfs_session_id_hash - calculate the crc32 hash for the session id
 130  * @session - pointer to session
 131  */
 132 #define nfs_session_id_hash(sess_id) \
 133         (~crc32_le(0xFFFFFFFF, &(sess_id)->data[0], sizeof((sess_id)->data)))
 134 #else
 135 #define nfs_session_id_hash(session) (0)
 136 #endif
 137 #else /* defined(CONFIG_NFS_V4_1) */
 138
 139 static inline int nfs4_init_session(struct nfs_client *clp)
 140 {
 141         return 0;
 142 }
 143
 144 /*
 145  * Determine if sessions are in use.
 146  */
 147 static inline int nfs4_has_session(const struct nfs_client *clp)
 148 {
 149         return 0;
 150 }
 151
 152 static inline int nfs4_has_persistent_session(const struct nfs_client *clp)
 153 {
 154         return 0;
 155 }
 156
 157 #endif /* defined(CONFIG_NFS_V4_1) */
 158 #endif /* IS_ENABLED(CONFIG_NFS_V4) */
 159 #endif /* __LINUX_FS_NFS_NFS4SESSION_H */