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   1 /*
   2  *  linux/include/linux/sunrpc/xprt.h
   3  *
   4  *  Declarations for the RPC transport interface.
   5  *
   6  *  Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
   7  */
   8
   9 #ifndef _LINUX_SUNRPC_XPRT_H
  10 #define _LINUX_SUNRPC_XPRT_H
  11
  12 #include <linux/uio.h>
  13 #include <linux/socket.h>
  14 #include <linux/in.h>
  15 #include <linux/kref.h>
  16 #include <linux/sunrpc/sched.h>
  17 #include <linux/sunrpc/xdr.h>
  18 #include <linux/sunrpc/msg_prot.h>
  19
  20 #ifdef __KERNEL__
  21
  22 #define RPC_MIN_SLOT_TABLE      (2U)
  23 #define RPC_DEF_SLOT_TABLE      (16U)
  24 #define RPC_MAX_SLOT_TABLE      (128U)
  25
  26 /*
  27  * This describes a timeout strategy
  28  */
  29 struct rpc_timeout {
  30         unsigned long           to_initval,             /* initial timeout */
  31                                 to_maxval,              /* max timeout */
  32                                 to_increment;           /* if !exponential */
  33         unsigned int            to_retries;             /* max # of retries */
  34         unsigned char           to_exponential;
  35 };
  36
  37 enum rpc_display_format_t {
  38         RPC_DISPLAY_ADDR = 0,
  39         RPC_DISPLAY_PORT,
  40         RPC_DISPLAY_PROTO,
  41         RPC_DISPLAY_HEX_ADDR,
  42         RPC_DISPLAY_HEX_PORT,
  43         RPC_DISPLAY_NETID,
  44         RPC_DISPLAY_MAX,
  45 };
  46
  47 struct rpc_task;
  48 struct rpc_xprt;
  49 struct seq_file;
  50
  51 /*
  52  * This describes a complete RPC request
  53  */
  54 struct rpc_rqst {
  55         /*
  56          * This is the user-visible part
  57          */
  58         struct rpc_xprt *       rq_xprt;                /* RPC client */
  59         struct xdr_buf          rq_snd_buf;             /* send buffer */
  60         struct xdr_buf          rq_rcv_buf;             /* recv buffer */
  61
  62         /*
  63          * This is the private part
  64          */
  65         struct rpc_task *       rq_task;        /* RPC task data */
  66         __be32                  rq_xid;         /* request XID */
  67         int                     rq_cong;        /* has incremented xprt->cong */
  68         int                     rq_reply_bytes_recvd;   /* number of reply */
  69                                                         /* bytes received */
  70         u32                     rq_seqno;       /* gss seq no. used on req. */
  71         int                     rq_enc_pages_num;
  72         struct page             **rq_enc_pages; /* scratch pages for use by
  73                                                    gss privacy code */
  74         void (*rq_release_snd_buf)(struct rpc_rqst *); /* release rq_enc_pages */
  75         struct list_head        rq_list;
  76
  77         __u32 *                 rq_buffer;      /* XDR encode buffer */
  78         size_t                  rq_callsize,
  79                                 rq_rcvsize;
  80
  81         struct xdr_buf          rq_private_buf;         /* The receive buffer
  82                                                          * used in the softirq.
  83                                                          */
  84         unsigned long           rq_majortimeo;  /* major timeout alarm */
  85         unsigned long           rq_timeout;     /* Current timeout value */
  86         unsigned int            rq_retries;     /* # of retries */
  87         unsigned int            rq_connect_cookie;
  88                                                 /* A cookie used to track the
  89                                                    state of the transport
  90                                                    connection */
  91
  92         /*
  93          * Partial send handling
  94          */
  95         u32                     rq_bytes_sent;  /* Bytes we have sent */
  96
  97         unsigned long           rq_xtime;       /* when transmitted */
  98         int                     rq_ntrans;
  99
 100 #if defined(CONFIG_NFS_V4_1)
 101         struct list_head        rq_bc_list;     /* Callback service list */
 102         unsigned long           rq_bc_pa_state; /* Backchannel prealloc state */
 103         struct list_head        rq_bc_pa_list;  /* Backchannel prealloc list */
 104 #endif /* CONFIG_NFS_V4_1 */
 105 };
 106 #define rq_svec                 rq_snd_buf.head
 107 #define rq_slen                 rq_snd_buf.len
 108
 109 struct rpc_xprt_ops {
 110         void            (*set_buffer_size)(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize);
 111         int             (*reserve_xprt)(struct rpc_task *task);
 112         void            (*release_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
 113         void            (*rpcbind)(struct rpc_task *task);
 114         void            (*set_port)(struct rpc_xprt *xprt, unsigned short port);
 115         void            (*connect)(struct rpc_task *task);
 116         void *          (*buf_alloc)(struct rpc_task *task, size_t size);
 117         void            (*buf_free)(void *buffer);
 118         int             (*send_request)(struct rpc_task *task);
 119         void            (*set_retrans_timeout)(struct rpc_task *task);
 120         void            (*timer)(struct rpc_task *task);
 121         void            (*release_request)(struct rpc_task *task);
 122         void            (*close)(struct rpc_xprt *xprt);
 123         void            (*destroy)(struct rpc_xprt *xprt);
 124         void            (*print_stats)(struct rpc_xprt *xprt, struct seq_file *seq);
 125 };
 126
 127 /*
 128  * RPC transport identifiers
 129  *
 130  * To preserve compatibility with the historical use of raw IP protocol
 131  * id's for transport selection, UDP and TCP identifiers are specified
 132  * with the previous values. No such restriction exists for new transports,
 133  * except that they may not collide with these values (17 and 6,
 134  * respectively).
 135  */
 136 #define XPRT_TRANSPORT_BC       (1 << 31)
 137 enum xprt_transports {
 138         XPRT_TRANSPORT_UDP      = IPPROTO_UDP,
 139         XPRT_TRANSPORT_TCP      = IPPROTO_TCP,
 140         XPRT_TRANSPORT_BC_TCP   = IPPROTO_TCP | XPRT_TRANSPORT_BC,
 141         XPRT_TRANSPORT_RDMA     = 256
 142 };
 143
 144 struct rpc_xprt {
 145         struct kref             kref;           /* Reference count */
 146         struct rpc_xprt_ops *   ops;            /* transport methods */
 147
 148         const struct rpc_timeout *timeout;      /* timeout parms */
 149         struct sockaddr_storage addr;           /* server address */
 150         size_t                  addrlen;        /* size of server address */
 151         int                     prot;           /* IP protocol */
 152
 153         unsigned long           cong;           /* current congestion */
 154         unsigned long           cwnd;           /* congestion window */
 155
 156         size_t                  max_payload;    /* largest RPC payload size,
 157                                                    in bytes */
 158         unsigned int            tsh_size;       /* size of transport specific
 159                                                    header */
 160
 161         struct rpc_wait_queue   binding;        /* requests waiting on rpcbind */
 162         struct rpc_wait_queue   sending;        /* requests waiting to send */
 163         struct rpc_wait_queue   resend;         /* requests waiting to resend */
 164         struct rpc_wait_queue   pending;        /* requests in flight */
 165         struct rpc_wait_queue   backlog;        /* waiting for slot */
 166         struct list_head        free;           /* free slots */
 167         struct rpc_rqst *       slot;           /* slot table storage */
 168         unsigned int            max_reqs;       /* total slots */
 169         unsigned long           state;          /* transport state */
 170         unsigned char           shutdown   : 1, /* being shut down */
 171                                 resvport   : 1; /* use a reserved port */
 172         unsigned int            bind_index;     /* bind function index */
 173
 174         /*
 175          * Connection of transports
 176          */
 177         unsigned long           connect_timeout,
 178                                 bind_timeout,
 179                                 reestablish_timeout;
 180         unsigned int            connect_cookie; /* A cookie that gets bumped
 181                                                    every time the transport
 182                                                    is reconnected */
 183
 184         /*
 185          * Disconnection of idle transports
 186          */
 187         struct work_struct      task_cleanup;
 188         struct timer_list       timer;
 189         unsigned long           last_used,
 190                                 idle_timeout;
 191
 192         /*
 193          * Send stuff
 194          */
 195         spinlock_t              transport_lock; /* lock transport info */
 196         spinlock_t              reserve_lock;   /* lock slot table */
 197         u32                     xid;            /* Next XID value to use */
 198         struct rpc_task *       snd_task;       /* Task blocked in send */
 199         struct svc_xprt         *bc_xprt;       /* NFSv4.1 backchannel */
 200 #if defined(CONFIG_NFS_V4_1)
 201         struct svc_serv         *bc_serv;       /* The RPC service which will */
 202                                                 /* process the callback */
 203         unsigned int            bc_alloc_count; /* Total number of preallocs */
 204         spinlock_t              bc_pa_lock;     /* Protects the preallocated
 205                                                  * items */
 206         struct list_head        bc_pa_list;     /* List of preallocated
 207                                                  * backchannel rpc_rqst's */
 208 #endif /* CONFIG_NFS_V4_1 */
 209         struct list_head        recv;
 210
 211         struct {
 212                 unsigned long           bind_count,     /* total number of binds */
 213                                         connect_count,  /* total number of connects */
 214                                         connect_start,  /* connect start timestamp */
 215                                         connect_time,   /* jiffies waiting for connect */
 216                                         sends,          /* how many complete requests */
 217                                         recvs,          /* how many complete requests */
 218                                         bad_xids;       /* lookup_rqst didn't find XID */
 219
 220                 unsigned long long      req_u,          /* average requests on the wire */
 221                                         bklog_u;        /* backlog queue utilization */
 222         } stat;
 223
 224         const char              *address_strings[RPC_DISPLAY_MAX];
 225 };
 226
 227 #if defined(CONFIG_NFS_V4_1)
 228 /*
 229  * Backchannel flags
 230  */
 231 #define RPC_BC_PA_IN_USE        0x0001          /* Preallocated backchannel */
 232                                                 /* buffer in use */
 233 #endif /* CONFIG_NFS_V4_1 */
 234
 235 #if defined(CONFIG_NFS_V4_1)
 236 static inline int bc_prealloc(struct rpc_rqst *req)
 237 {
 238         return test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
 239 }
 240 #else
 241 static inline int bc_prealloc(struct rpc_rqst *req)
 242 {
 243         return 0;
 244 }
 245 #endif /* CONFIG_NFS_V4_1 */
 246
 247 struct xprt_create {
 248         int                     ident;          /* XPRT_TRANSPORT identifier */
 249         struct sockaddr *       srcaddr;        /* optional local address */
 250         struct sockaddr *       dstaddr;        /* remote peer address */
 251         size_t                  addrlen;
 252         struct svc_xprt         *bc_xprt;       /* NFSv4.1 backchannel */
 253 };
 254
 255 struct xprt_class {
 256         struct list_head        list;
 257         int                     ident;          /* XPRT_TRANSPORT identifier */
 258         struct rpc_xprt *       (*setup)(struct xprt_create *);
 259         struct module           *owner;
 260         char                    name[32];
 261 };
 262
 263 /*
 264  * Generic internal transport functions
 265  */
 266 struct rpc_xprt         *xprt_create_transport(struct xprt_create *args);
 267 void                    xprt_connect(struct rpc_task *task);
 268 void                    xprt_reserve(struct rpc_task *task);
 269 int                     xprt_reserve_xprt(struct rpc_task *task);
 270 int                     xprt_reserve_xprt_cong(struct rpc_task *task);
 271 int                     xprt_prepare_transmit(struct rpc_task *task);
 272 void                    xprt_transmit(struct rpc_task *task);
 273 void                    xprt_end_transmit(struct rpc_task *task);
 274 int                     xprt_adjust_timeout(struct rpc_rqst *req);
 275 void                    xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
 276 void                    xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
 277 void                    xprt_release(struct rpc_task *task);
 278 struct rpc_xprt *       xprt_get(struct rpc_xprt *xprt);
 279 void                    xprt_put(struct rpc_xprt *xprt);
 280
 281 static inline __be32 *xprt_skip_transport_header(struct rpc_xprt *xprt, __be32 *p)
 282 {
 283         return p + xprt->tsh_size;
 284 }
 285
 286 /*
 287  * Transport switch helper functions
 288  */
 289 int                     xprt_register_transport(struct xprt_class *type);
 290 int                     xprt_unregister_transport(struct xprt_class *type);
 291 int                     xprt_load_transport(const char *);
 292 void                    xprt_set_retrans_timeout_def(struct rpc_task *task);
 293 void                    xprt_set_retrans_timeout_rtt(struct rpc_task *task);
 294 void                    xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status);
 295 void                    xprt_wait_for_buffer_space(struct rpc_task *task, rpc_action action);
 296 void                    xprt_write_space(struct rpc_xprt *xprt);
 297 void                    xprt_update_rtt(struct rpc_task *task);
 298 void                    xprt_adjust_cwnd(struct rpc_task *task, int result);
 299 struct rpc_rqst *       xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid);
 300 void                    xprt_complete_rqst(struct rpc_task *task, int copied);
 301 void                    xprt_release_rqst_cong(struct rpc_task *task);
 302 void                    xprt_disconnect_done(struct rpc_xprt *xprt);
 303 void                    xprt_force_disconnect(struct rpc_xprt *xprt);
 304 void                    xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie);
 305
 306 /*
 307  * Reserved bit positions in xprt->state
 308  */
 309 #define XPRT_LOCKED             (0)
 310 #define XPRT_CONNECTED          (1)
 311 #define XPRT_CONNECTING         (2)
 312 #define XPRT_CLOSE_WAIT         (3)
 313 #define XPRT_BOUND              (4)
 314 #define XPRT_BINDING            (5)
 315 #define XPRT_CLOSING            (6)
 316 #define XPRT_CONNECTION_ABORT   (7)
 317 #define XPRT_CONNECTION_CLOSE   (8)
 318
 319 static inline void xprt_set_connected(struct rpc_xprt *xprt)
 320 {
 321         set_bit(XPRT_CONNECTED, &xprt->state);
 322 }
 323
 324 static inline void xprt_clear_connected(struct rpc_xprt *xprt)
 325 {
 326         clear_bit(XPRT_CONNECTED, &xprt->state);
 327 }
 328
 329 static inline int xprt_connected(struct rpc_xprt *xprt)
 330 {
 331         return test_bit(XPRT_CONNECTED, &xprt->state);
 332 }
 333
 334 static inline int xprt_test_and_set_connected(struct rpc_xprt *xprt)
 335 {
 336         return test_and_set_bit(XPRT_CONNECTED, &xprt->state);
 337 }
 338
 339 static inline int xprt_test_and_clear_connected(struct rpc_xprt *xprt)
 340 {
 341         return test_and_clear_bit(XPRT_CONNECTED, &xprt->state);
 342 }
 343
 344 static inline void xprt_clear_connecting(struct rpc_xprt *xprt)
 345 {
 346         smp_mb__before_clear_bit();
 347         clear_bit(XPRT_CONNECTING, &xprt->state);
 348         smp_mb__after_clear_bit();
 349 }
 350
 351 static inline int xprt_connecting(struct rpc_xprt *xprt)
 352 {
 353         return test_bit(XPRT_CONNECTING, &xprt->state);
 354 }
 355
 356 static inline int xprt_test_and_set_connecting(struct rpc_xprt *xprt)
 357 {
 358         return test_and_set_bit(XPRT_CONNECTING, &xprt->state);
 359 }
 360
 361 static inline void xprt_set_bound(struct rpc_xprt *xprt)
 362 {
 363         test_and_set_bit(XPRT_BOUND, &xprt->state);
 364 }
 365
 366 static inline int xprt_bound(struct rpc_xprt *xprt)
 367 {
 368         return test_bit(XPRT_BOUND, &xprt->state);
 369 }
 370
 371 static inline void xprt_clear_bound(struct rpc_xprt *xprt)
 372 {
 373         clear_bit(XPRT_BOUND, &xprt->state);
 374 }
 375
 376 static inline void xprt_clear_binding(struct rpc_xprt *xprt)
 377 {
 378         smp_mb__before_clear_bit();
 379         clear_bit(XPRT_BINDING, &xprt->state);
 380         smp_mb__after_clear_bit();
 381 }
 382
 383 static inline int xprt_test_and_set_binding(struct rpc_xprt *xprt)
 384 {
 385         return test_and_set_bit(XPRT_BINDING, &xprt->state);
 386 }
 387
 388 #endif /* __KERNEL__*/
 389
 390 #endif /* _LINUX_SUNRPC_XPRT_H */