fs/nfs/nfs4session.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * fs/nfs/nfs4session.h
   4  *
   5  * Copyright (c) 2012 Trond Myklebust <Trond.Myklebust@netapp.com>
   6  *
   7  */
   8 #ifndef __LINUX_FS_NFS_NFS4SESSION_H
   9 #define __LINUX_FS_NFS_NFS4SESSION_H
  10
  11 /* maximum number of slots to use */
  12 #define NFS4_DEF_SLOT_TABLE_SIZE (64U)
  13 #define NFS4_DEF_CB_SLOT_TABLE_SIZE (16U)
  14 #define NFS4_MAX_SLOT_TABLE (1024U)
  15 #define NFS4_MAX_SLOTID (NFS4_MAX_SLOT_TABLE - 1U)
  16 #define NFS4_NO_SLOT ((u32)-1)
  17
  18 #if IS_ENABLED(CONFIG_NFS_V4)
  19
  20 /* Sessions slot seqid */
  21 struct nfs4_slot {
  22         struct nfs4_slot_table  *table;
  23         struct nfs4_slot        *next;
  24         unsigned long           generation;
  25         u32                     slot_nr;
  26         u32                     seq_nr;
  27         u32                     seq_nr_last_acked;
  28         u32                     seq_nr_highest_sent;
  29         unsigned int            privileged : 1,
  30                                 seq_done : 1;
  31 };
  32
  33 /* Sessions */
  34 enum nfs4_slot_tbl_state {
  35         NFS4_SLOT_TBL_DRAINING,
  36 };
  37
  38 #define SLOT_TABLE_SZ DIV_ROUND_UP(NFS4_MAX_SLOT_TABLE, BITS_PER_LONG)
  39 struct nfs4_slot_table {
  40         struct nfs4_session *session;           /* Parent session */
  41         struct nfs4_slot *slots;                /* seqid per slot */
  42         unsigned long   used_slots[SLOT_TABLE_SZ]; /* used/unused bitmap */
  43         spinlock_t      slot_tbl_lock;
  44         struct rpc_wait_queue   slot_tbl_waitq; /* allocators may wait here */
  45         wait_queue_head_t       slot_waitq;     /* Completion wait on slot */
  46         u32             max_slots;              /* # slots in table */
  47         u32             max_slotid;             /* Max allowed slotid value */
  48         u32             highest_used_slotid;    /* sent to server on each SEQ.
  49                                                  * op for dynamic resizing */
  50         u32             target_highest_slotid;  /* Server max_slot target */
  51         u32             server_highest_slotid;  /* Server highest slotid */
  52         s32             d_target_highest_slotid; /* Derivative */
  53         s32             d2_target_highest_slotid; /* 2nd derivative */
  54         unsigned long   generation;             /* Generation counter for
  55                                                    target_highest_slotid */
  56         struct completion complete;
  57         unsigned long   slot_tbl_state;
  58 };
  59
  60 /*
  61  * Session related parameters
  62  */
  63 struct nfs4_session {
  64         struct nfs4_sessionid           sess_id;
  65         u32                             flags;
  66         unsigned long                   session_state;
  67         u32                             hash_alg;
  68         u32                             ssv_len;
  69
  70         /* The fore and back channel */
  71         struct nfs4_channel_attrs       fc_attrs;
  72         struct nfs4_slot_table          fc_slot_table;
  73         struct nfs4_channel_attrs       bc_attrs;
  74         struct nfs4_slot_table          bc_slot_table;
  75         struct nfs_client               *clp;
  76 };
  77
  78 enum nfs4_session_state {
  79         NFS4_SESSION_INITING,
  80         NFS4_SESSION_ESTABLISHED,
  81 };
  82
  83 extern int nfs4_setup_slot_table(struct nfs4_slot_table *tbl,
  84                 unsigned int max_reqs, const char *queue);
  85 extern void nfs4_shutdown_slot_table(struct nfs4_slot_table *tbl);
  86 extern struct nfs4_slot *nfs4_alloc_slot(struct nfs4_slot_table *tbl);
  87 extern struct nfs4_slot *nfs4_lookup_slot(struct nfs4_slot_table *tbl, u32 slotid);
  88 extern int nfs4_slot_wait_on_seqid(struct nfs4_slot_table *tbl,
  89                 u32 slotid, u32 seq_nr,
  90                 unsigned long timeout);
  91 extern bool nfs4_try_to_lock_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot);
  92 extern void nfs4_free_slot(struct nfs4_slot_table *tbl, struct nfs4_slot *slot);
  93 extern void nfs4_slot_tbl_drain_complete(struct nfs4_slot_table *tbl);
  94 bool nfs41_wake_and_assign_slot(struct nfs4_slot_table *tbl,
  95                 struct nfs4_slot *slot);
  96 void nfs41_wake_slot_table(struct nfs4_slot_table *tbl);
  97
  98 static inline bool nfs4_slot_tbl_draining(struct nfs4_slot_table *tbl)
  99 {
 100         return !!test_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state);
 101 }
 102
 103 static inline bool nfs4_test_locked_slot(const struct nfs4_slot_table *tbl,
 104                 u32 slotid)
 105 {
 106         return !!test_bit(slotid, tbl->used_slots);
 107 }
 108
 109 static inline struct nfs4_session *nfs4_get_session(const struct nfs_client *clp)
 110 {
 111         return clp->cl_session;
 112 }
 113
 114 #if defined(CONFIG_NFS_V4_1)
 115 extern void nfs41_set_target_slotid(struct nfs4_slot_table *tbl,
 116                 u32 target_highest_slotid);
 117 extern void nfs41_update_target_slotid(struct nfs4_slot_table *tbl,
 118                 struct nfs4_slot *slot,
 119                 struct nfs4_sequence_res *res);
 120
 121 extern int nfs4_setup_session_slot_tables(struct nfs4_session *ses);
 122
 123 extern struct nfs4_session *nfs4_alloc_session(struct nfs_client *clp);
 124 extern void nfs4_destroy_session(struct nfs4_session *session);
 125 extern int nfs4_init_session(struct nfs_client *clp);
 126 extern int nfs4_init_ds_session(struct nfs_client *, unsigned long);
 127
 128 /*
 129  * Determine if sessions are in use.
 130  */
 131 static inline int nfs4_has_session(const struct nfs_client *clp)
 132 {
 133         if (clp->cl_session)
 134                 return 1;
 135         return 0;
 136 }
 137
 138 static inline int nfs4_has_persistent_session(const struct nfs_client *clp)
 139 {
 140         if (nfs4_has_session(clp))
 141                 return (clp->cl_session->flags & SESSION4_PERSIST);
 142         return 0;
 143 }
 144
 145 static inline void nfs4_copy_sessionid(struct nfs4_sessionid *dst,
 146                 const struct nfs4_sessionid *src)
 147 {
 148         memcpy(dst->data, src->data, NFS4_MAX_SESSIONID_LEN);
 149 }
 150
 151 #ifdef CONFIG_CRC32
 152 /*
 153  * nfs_session_id_hash - calculate the crc32 hash for the session id
 154  * @session - pointer to session
 155  */
 156 #define nfs_session_id_hash(sess_id) \
 157         (~crc32_le(0xFFFFFFFF, &(sess_id)->data[0], sizeof((sess_id)->data)))
 158 #else
 159 #define nfs_session_id_hash(session) (0)
 160 #endif
 161 #else /* defined(CONFIG_NFS_V4_1) */
 162
 163 static inline int nfs4_init_session(struct nfs_client *clp)
 164 {
 165         return 0;
 166 }
 167
 168 /*
 169  * Determine if sessions are in use.
 170  */
 171 static inline int nfs4_has_session(const struct nfs_client *clp)
 172 {
 173         return 0;
 174 }
 175
 176 static inline int nfs4_has_persistent_session(const struct nfs_client *clp)
 177 {
 178         return 0;
 179 }
 180
 181 #define nfs_session_id_hash(session) (0)
 182
 183 #endif /* defined(CONFIG_NFS_V4_1) */
 184 #endif /* IS_ENABLED(CONFIG_NFS_V4) */
 185 #endif /* __LINUX_FS_NFS_NFS4SESSION_H */