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                                 seq_done : 1;
  26 };
  27
  28 /* Sessions */
  29 enum 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))
  34 struct 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  */
  58 struct 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
  73 enum nfs4_session_state {
  74         NFS4_SESSION_INITING,
  75         NFS4_SESSION_ESTABLISHED,
  76 };
  77
  78 extern int nfs4_setup_slot_table(struct nfs4_slot_table *tbl,
  79                 unsigned int max_reqs, const char *queue);
  80 extern void nfs4_shutdown_slot_table(struct nfs4_slot_table *tbl);
  81 extern struct nfs4_slot *nfs4_alloc_slot(struct nfs4_slot_table *tbl);
  82 extern struct nfs4_slot *nfs4_lookup_slot(struct nfs4_slot_table *tbl, u32 slotid);
  83 extern int nfs4_slot_wait_on_seqid(struct nfs4_slot_table *tbl,
  84                 u32 slotid, u32 seq_nr,
  85                 unsigned long timeout);
  86 extern bool nfs4_try_to_lock_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot);
  87 extern void nfs4_free_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot);
  88 extern void nfs4_slot_tbl_drain_complete(struct nfs4_slot_table *tbl);
  89 bool nfs41_wake_and_assign_slot(struct nfs4_slot_table *tbl,
  90                 struct nfs4_slot *slot);
  91 void nfs41_wake_slot_table(struct nfs4_slot_table *tbl);
  92
  93 static 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
  98 static 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)
 105 extern void nfs41_set_target_slotid(struct nfs4_slot_table *tbl,
 106                 u32 target_highest_slotid);
 107 extern void nfs41_update_target_slotid(struct nfs4_slot_table *tbl,
 108                 struct nfs4_slot *slot,
 109                 struct nfs4_sequence_res *res);
 110
 111 extern int nfs4_setup_session_slot_tables(struct nfs4_session *ses);
 112
 113 extern struct nfs4_session *nfs4_alloc_session(struct nfs_client *clp);
 114 extern void nfs4_destroy_session(struct nfs4_session *session);
 115 extern int nfs4_init_session(struct nfs_client *clp);
 116 extern int nfs4_init_ds_session(struct nfs_client *, unsigned long);
 117
 118 /*
 119  * Determine if sessions are in use.
 120  */
 121 static inline int nfs4_has_session(const struct nfs_client *clp)
 122 {
 123         if (clp->cl_session)
 124                 return 1;
 125         return 0;
 126 }
 127
 128 static 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
 135 static 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
 153 static inline int nfs4_init_session(struct nfs_client *clp)
 154 {
 155         return 0;
 156 }
 157
 158 /*
 159  * Determine if sessions are in use.
 160  */
 161 static inline int nfs4_has_session(const struct nfs_client *clp)
 162 {
 163         return 0;
 164 }
 165
 166 static 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 */