include/linux/sunrpc/xprt.h

   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/ktime.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_LIMIT        (65536U)
  25 #define RPC_MAX_SLOT_TABLE      RPC_MAX_SLOT_TABLE_LIMIT
  26
  27 /*
  28  * This describes a timeout strategy
  29  */
  30 struct rpc_timeout {
  31         unsigned long           to_initval,             /* initial timeout */
  32                                 to_maxval,              /* max timeout */
  33                                 to_increment;           /* if !exponential */
  34         unsigned int            to_retries;             /* max # of retries */
  35         unsigned char           to_exponential;
  36 };
  37
  38 enum rpc_display_format_t {
  39         RPC_DISPLAY_ADDR = 0,
  40         RPC_DISPLAY_PORT,
  41         RPC_DISPLAY_PROTO,
  42         RPC_DISPLAY_HEX_ADDR,
  43         RPC_DISPLAY_HEX_PORT,
  44         RPC_DISPLAY_NETID,
  45         RPC_DISPLAY_MAX,
  46 };
  47
  48 struct rpc_task;
  49 struct rpc_xprt;
  50 struct seq_file;
  51
  52 /*
  53  * This describes a complete RPC request
  54  */
  55 struct rpc_rqst {
  56         /*
  57          * This is the user-visible part
  58          */
  59         struct rpc_xprt *       rq_xprt;                /* RPC client */
  60         struct xdr_buf          rq_snd_buf;             /* send buffer */
  61         struct xdr_buf          rq_rcv_buf;             /* recv buffer */
  62
  63         /*
  64          * This is the private part
  65          */
  66         struct rpc_task *       rq_task;        /* RPC task data */
  67         struct rpc_cred *       rq_cred;        /* Bound cred */
  68         __be32                  rq_xid;         /* request XID */
  69         int                     rq_cong;        /* has incremented xprt->cong */
  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         size_t                  rq_xmit_bytes_sent;     /* total bytes sent */
  81         size_t                  rq_reply_bytes_recvd;   /* total reply bytes */
  82                                                         /* received */
  83
  84         struct xdr_buf          rq_private_buf;         /* The receive buffer
  85                                                          * used in the softirq.
  86                                                          */
  87         unsigned long           rq_majortimeo;  /* major timeout alarm */
  88         unsigned long           rq_timeout;     /* Current timeout value */
  89         ktime_t                 rq_rtt;         /* round-trip time */
  90         unsigned int            rq_retries;     /* # of retries */
  91         unsigned int            rq_connect_cookie;
  92                                                 /* A cookie used to track the
  93                                                    state of the transport
  94                                                    connection */
  95
  96         /*
  97          * Partial send handling
  98          */
  99         u32                     rq_bytes_sent;  /* Bytes we have sent */
 100
 101         ktime_t                 rq_xtime;       /* transmit time stamp */
 102         int                     rq_ntrans;
 103
 104 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 105         struct list_head        rq_bc_list;     /* Callback service list */
 106         unsigned long           rq_bc_pa_state; /* Backchannel prealloc state */
 107         struct list_head        rq_bc_pa_list;  /* Backchannel prealloc list */
 108 #endif /* CONFIG_SUNRPC_BACKCHANEL */
 109 };
 110 #define rq_svec                 rq_snd_buf.head
 111 #define rq_slen                 rq_snd_buf.len
 112
 113 struct rpc_xprt_ops {
 114         void            (*set_buffer_size)(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize);
 115         int             (*reserve_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
 116         void            (*release_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
 117         void            (*alloc_slot)(struct rpc_xprt *xprt, struct rpc_task *task);
 118         void            (*rpcbind)(struct rpc_task *task);
 119         void            (*set_port)(struct rpc_xprt *xprt, unsigned short port);
 120         void            (*connect)(struct rpc_xprt *xprt, struct rpc_task *task);
 121         void *          (*buf_alloc)(struct rpc_task *task, size_t size);
 122         void            (*buf_free)(void *buffer);
 123         int             (*send_request)(struct rpc_task *task);
 124         void            (*set_retrans_timeout)(struct rpc_task *task);
 125         void            (*timer)(struct rpc_xprt *xprt, struct rpc_task *task);
 126         void            (*release_request)(struct rpc_task *task);
 127         void            (*close)(struct rpc_xprt *xprt);
 128         void            (*destroy)(struct rpc_xprt *xprt);
 129         void            (*print_stats)(struct rpc_xprt *xprt, struct seq_file *seq);
 130 };
 131
 132 /*
 133  * RPC transport identifiers
 134  *
 135  * To preserve compatibility with the historical use of raw IP protocol
 136  * id's for transport selection, UDP and TCP identifiers are specified
 137  * with the previous values. No such restriction exists for new transports,
 138  * except that they may not collide with these values (17 and 6,
 139  * respectively).
 140  */
 141 #define XPRT_TRANSPORT_BC       (1 << 31)
 142 enum xprt_transports {
 143         XPRT_TRANSPORT_UDP      = IPPROTO_UDP,
 144         XPRT_TRANSPORT_TCP      = IPPROTO_TCP,
 145         XPRT_TRANSPORT_BC_TCP   = IPPROTO_TCP | XPRT_TRANSPORT_BC,
 146         XPRT_TRANSPORT_RDMA     = 256,
 147         XPRT_TRANSPORT_LOCAL    = 257,
 148 };
 149
 150 struct rpc_xprt {
 151         atomic_t                count;          /* Reference count */
 152         struct rpc_xprt_ops *   ops;            /* transport methods */
 153
 154         const struct rpc_timeout *timeout;      /* timeout parms */
 155         struct sockaddr_storage addr;           /* server address */
 156         size_t                  addrlen;        /* size of server address */
 157         int                     prot;           /* IP protocol */
 158
 159         unsigned long           cong;           /* current congestion */
 160         unsigned long           cwnd;           /* congestion window */
 161
 162         size_t                  max_payload;    /* largest RPC payload size,
 163                                                    in bytes */
 164         unsigned int            tsh_size;       /* size of transport specific
 165                                                    header */
 166
 167         struct rpc_wait_queue   binding;        /* requests waiting on rpcbind */
 168         struct rpc_wait_queue   sending;        /* requests waiting to send */
 169         struct rpc_wait_queue   pending;        /* requests in flight */
 170         struct rpc_wait_queue   backlog;        /* waiting for slot */
 171         struct list_head        free;           /* free slots */
 172         unsigned int            max_reqs;       /* max number of slots */
 173         unsigned int            min_reqs;       /* min number of slots */
 174         atomic_t                num_reqs;       /* total slots */
 175         unsigned long           state;          /* transport state */
 176         unsigned char           resvport   : 1; /* use a reserved port */
 177         unsigned int            swapper;        /* we're swapping over this
 178                                                    transport */
 179         unsigned int            bind_index;     /* bind function index */
 180
 181         /*
 182          * Connection of transports
 183          */
 184         unsigned long           bind_timeout,
 185                                 reestablish_timeout;
 186         unsigned int            connect_cookie; /* A cookie that gets bumped
 187                                                    every time the transport
 188                                                    is reconnected */
 189
 190         /*
 191          * Disconnection of idle transports
 192          */
 193         struct work_struct      task_cleanup;
 194         struct timer_list       timer;
 195         unsigned long           last_used,
 196                                 idle_timeout;
 197
 198         /*
 199          * Send stuff
 200          */
 201         spinlock_t              transport_lock; /* lock transport info */
 202         spinlock_t              reserve_lock;   /* lock slot table */
 203         u32                     xid;            /* Next XID value to use */
 204         struct rpc_task *       snd_task;       /* Task blocked in send */
 205         struct svc_xprt         *bc_xprt;       /* NFSv4.1 backchannel */
 206 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 207         struct svc_serv         *bc_serv;       /* The RPC service which will */
 208                                                 /* process the callback */
 209         unsigned int            bc_alloc_count; /* Total number of preallocs */
 210         spinlock_t              bc_pa_lock;     /* Protects the preallocated
 211                                                  * items */
 212         struct list_head        bc_pa_list;     /* List of preallocated
 213                                                  * backchannel rpc_rqst's */
 214 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
 215         struct list_head        recv;
 216
 217         struct {
 218                 unsigned long           bind_count,     /* total number of binds */
 219                                         connect_count,  /* total number of connects */
 220                                         connect_start,  /* connect start timestamp */
 221                                         connect_time,   /* jiffies waiting for connect */
 222                                         sends,          /* how many complete requests */
 223                                         recvs,          /* how many complete requests */
 224                                         bad_xids,       /* lookup_rqst didn't find XID */
 225                                         max_slots;      /* max rpc_slots used */
 226
 227                 unsigned long long      req_u,          /* average requests on the wire */
 228                                         bklog_u,        /* backlog queue utilization */
 229                                         sending_u,      /* send q utilization */
 230                                         pending_u;      /* pend q utilization */
 231         } stat;
 232
 233         struct net              *xprt_net;
 234         const char              *servername;
 235         const char              *address_strings[RPC_DISPLAY_MAX];
 236 };
 237
 238 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 239 /*
 240  * Backchannel flags
 241  */
 242 #define RPC_BC_PA_IN_USE        0x0001          /* Preallocated backchannel */
 243                                                 /* buffer in use */
 244 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
 245
 246 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 247 static inline int bc_prealloc(struct rpc_rqst *req)
 248 {
 249         return test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
 250 }
 251 #else
 252 static inline int bc_prealloc(struct rpc_rqst *req)
 253 {
 254         return 0;
 255 }
 256 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
 257
 258 #define XPRT_CREATE_INFINITE_SLOTS      (1U)
 259 #define XPRT_CREATE_NO_IDLE_TIMEOUT     (1U << 1)
 260
 261 struct xprt_create {
 262         int                     ident;          /* XPRT_TRANSPORT identifier */
 263         struct net *            net;
 264         struct sockaddr *       srcaddr;        /* optional local address */
 265         struct sockaddr *       dstaddr;        /* remote peer address */
 266         size_t                  addrlen;
 267         const char              *servername;
 268         struct svc_xprt         *bc_xprt;       /* NFSv4.1 backchannel */
 269         unsigned int            flags;
 270 };
 271
 272 struct xprt_class {
 273         struct list_head        list;
 274         int                     ident;          /* XPRT_TRANSPORT identifier */
 275         struct rpc_xprt *       (*setup)(struct xprt_create *);
 276         struct module           *owner;
 277         char                    name[32];
 278 };
 279
 280 /*
 281  * Generic internal transport functions
 282  */
 283 struct rpc_xprt         *xprt_create_transport(struct xprt_create *args);
 284 void                    xprt_connect(struct rpc_task *task);
 285 void                    xprt_reserve(struct rpc_task *task);
 286 void                    xprt_retry_reserve(struct rpc_task *task);
 287 int                     xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
 288 int                     xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
 289 void                    xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
 290 void                    xprt_lock_and_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
 291 bool                    xprt_prepare_transmit(struct rpc_task *task);
 292 void                    xprt_transmit(struct rpc_task *task);
 293 void                    xprt_end_transmit(struct rpc_task *task);
 294 int                     xprt_adjust_timeout(struct rpc_rqst *req);
 295 void                    xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
 296 void                    xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
 297 void                    xprt_release(struct rpc_task *task);
 298 void                    xprt_put(struct rpc_xprt *xprt);
 299 struct rpc_xprt *       xprt_alloc(struct net *net, size_t size,
 300                                 unsigned int num_prealloc,
 301                                 unsigned int max_req);
 302 void                    xprt_free(struct rpc_xprt *);
 303
 304 /**
 305  * xprt_get - return a reference to an RPC transport.
 306  * @xprt: pointer to the transport
 307  *
 308  */
 309 static inline struct rpc_xprt *xprt_get(struct rpc_xprt *xprt)
 310 {
 311         if (atomic_inc_not_zero(&xprt->count))
 312                 return xprt;
 313         return NULL;
 314 }
 315
 316 static inline __be32 *xprt_skip_transport_header(struct rpc_xprt *xprt, __be32 *p)
 317 {
 318         return p + xprt->tsh_size;
 319 }
 320
 321 /*
 322  * Transport switch helper functions
 323  */
 324 int                     xprt_register_transport(struct xprt_class *type);
 325 int                     xprt_unregister_transport(struct xprt_class *type);
 326 int                     xprt_load_transport(const char *);
 327 void                    xprt_set_retrans_timeout_def(struct rpc_task *task);
 328 void                    xprt_set_retrans_timeout_rtt(struct rpc_task *task);
 329 void                    xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status);
 330 void                    xprt_wait_for_buffer_space(struct rpc_task *task, rpc_action action);
 331 void                    xprt_write_space(struct rpc_xprt *xprt);
 332 void                    xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result);
 333 struct rpc_rqst *       xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid);
 334 void                    xprt_complete_rqst(struct rpc_task *task, int copied);
 335 void                    xprt_release_rqst_cong(struct rpc_task *task);
 336 void                    xprt_disconnect_done(struct rpc_xprt *xprt);
 337 void                    xprt_force_disconnect(struct rpc_xprt *xprt);
 338 void                    xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie);
 339 int                     xs_swapper(struct rpc_xprt *xprt, int enable);
 340
 341 /*
 342  * Reserved bit positions in xprt->state
 343  */
 344 #define XPRT_LOCKED             (0)
 345 #define XPRT_CONNECTED          (1)
 346 #define XPRT_CONNECTING         (2)
 347 #define XPRT_CLOSE_WAIT         (3)
 348 #define XPRT_BOUND              (4)
 349 #define XPRT_BINDING            (5)
 350 #define XPRT_CLOSING            (6)
 351 #define XPRT_CONNECTION_ABORT   (7)
 352 #define XPRT_CONNECTION_CLOSE   (8)
 353 #define XPRT_CONGESTED          (9)
 354
 355 static inline void xprt_set_connected(struct rpc_xprt *xprt)
 356 {
 357         set_bit(XPRT_CONNECTED, &xprt->state);
 358 }
 359
 360 static inline void xprt_clear_connected(struct rpc_xprt *xprt)
 361 {
 362         clear_bit(XPRT_CONNECTED, &xprt->state);
 363 }
 364
 365 static inline int xprt_connected(struct rpc_xprt *xprt)
 366 {
 367         return test_bit(XPRT_CONNECTED, &xprt->state);
 368 }
 369
 370 static inline int xprt_test_and_set_connected(struct rpc_xprt *xprt)
 371 {
 372         return test_and_set_bit(XPRT_CONNECTED, &xprt->state);
 373 }
 374
 375 static inline int xprt_test_and_clear_connected(struct rpc_xprt *xprt)
 376 {
 377         return test_and_clear_bit(XPRT_CONNECTED, &xprt->state);
 378 }
 379
 380 static inline void xprt_clear_connecting(struct rpc_xprt *xprt)
 381 {
 382         smp_mb__before_atomic();
 383         clear_bit(XPRT_CONNECTING, &xprt->state);
 384         smp_mb__after_atomic();
 385 }
 386
 387 static inline int xprt_connecting(struct rpc_xprt *xprt)
 388 {
 389         return test_bit(XPRT_CONNECTING, &xprt->state);
 390 }
 391
 392 static inline int xprt_test_and_set_connecting(struct rpc_xprt *xprt)
 393 {
 394         return test_and_set_bit(XPRT_CONNECTING, &xprt->state);
 395 }
 396
 397 static inline void xprt_set_bound(struct rpc_xprt *xprt)
 398 {
 399         test_and_set_bit(XPRT_BOUND, &xprt->state);
 400 }
 401
 402 static inline int xprt_bound(struct rpc_xprt *xprt)
 403 {
 404         return test_bit(XPRT_BOUND, &xprt->state);
 405 }
 406
 407 static inline void xprt_clear_bound(struct rpc_xprt *xprt)
 408 {
 409         clear_bit(XPRT_BOUND, &xprt->state);
 410 }
 411
 412 static inline void xprt_clear_binding(struct rpc_xprt *xprt)
 413 {
 414         smp_mb__before_atomic();
 415         clear_bit(XPRT_BINDING, &xprt->state);
 416         smp_mb__after_atomic();
 417 }
 418
 419 static inline int xprt_test_and_set_binding(struct rpc_xprt *xprt)
 420 {
 421         return test_and_set_bit(XPRT_BINDING, &xprt->state);
 422 }
 423
 424 #endif /* __KERNEL__*/
 425
 426 #endif /* _LINUX_SUNRPC_XPRT_H */