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/kref.h>
  17 #include <linux/sunrpc/sched.h>
  18 #include <linux/sunrpc/xdr.h>
  19 #include <linux/sunrpc/msg_prot.h>
  20
  21 #ifdef __KERNEL__
  22
  23 #define RPC_MIN_SLOT_TABLE      (2U)
  24 #define RPC_DEF_SLOT_TABLE      (16U)
  25 #define RPC_MAX_SLOT_TABLE_LIMIT        (65536U)
  26 #define RPC_MAX_SLOT_TABLE      RPC_MAX_SLOT_TABLE_LIMIT
  27
  28 #define RPC_CWNDSHIFT           (8U)
  29 #define RPC_CWNDSCALE           (1U << RPC_CWNDSHIFT)
  30 #define RPC_INITCWND            RPC_CWNDSCALE
  31 #define RPC_MAXCWND(xprt)       ((xprt)->max_reqs << RPC_CWNDSHIFT)
  32 #define RPCXPRT_CONGESTED(xprt) ((xprt)->cong >= (xprt)->cwnd)
  33
  34 /*
  35  * This describes a timeout strategy
  36  */
  37 struct rpc_timeout {
  38         unsigned long           to_initval,             /* initial timeout */
  39                                 to_maxval,              /* max timeout */
  40                                 to_increment;           /* if !exponential */
  41         unsigned int            to_retries;             /* max # of retries */
  42         unsigned char           to_exponential;
  43 };
  44
  45 enum rpc_display_format_t {
  46         RPC_DISPLAY_ADDR = 0,
  47         RPC_DISPLAY_PORT,
  48         RPC_DISPLAY_PROTO,
  49         RPC_DISPLAY_HEX_ADDR,
  50         RPC_DISPLAY_HEX_PORT,
  51         RPC_DISPLAY_NETID,
  52         RPC_DISPLAY_MAX,
  53 };
  54
  55 struct rpc_task;
  56 struct rpc_xprt;
  57 struct seq_file;
  58 struct svc_serv;
  59 struct net;
  60
  61 /*
  62  * This describes a complete RPC request
  63  */
  64 struct rpc_rqst {
  65         /*
  66          * This is the user-visible part
  67          */
  68         struct rpc_xprt *       rq_xprt;                /* RPC client */
  69         struct xdr_buf          rq_snd_buf;             /* send buffer */
  70         struct xdr_buf          rq_rcv_buf;             /* recv buffer */
  71
  72         /*
  73          * This is the private part
  74          */
  75         struct rpc_task *       rq_task;        /* RPC task data */
  76         struct rpc_cred *       rq_cred;        /* Bound cred */
  77         __be32                  rq_xid;         /* request XID */
  78         int                     rq_cong;        /* has incremented xprt->cong */
  79         u32                     rq_seqno;       /* gss seq no. used on req. */
  80         int                     rq_enc_pages_num;
  81         struct page             **rq_enc_pages; /* scratch pages for use by
  82                                                    gss privacy code */
  83         void (*rq_release_snd_buf)(struct rpc_rqst *); /* release rq_enc_pages */
  84         struct list_head        rq_list;
  85
  86         void                    *rq_xprtdata;   /* Per-xprt private data */
  87         void                    *rq_buffer;     /* Call XDR encode buffer */
  88         size_t                  rq_callsize;
  89         void                    *rq_rbuffer;    /* Reply XDR decode buffer */
  90         size_t                  rq_rcvsize;
  91         size_t                  rq_xmit_bytes_sent;     /* total bytes sent */
  92         size_t                  rq_reply_bytes_recvd;   /* total reply bytes */
  93                                                         /* received */
  94
  95         struct xdr_buf          rq_private_buf;         /* The receive buffer
  96                                                          * used in the softirq.
  97                                                          */
  98         unsigned long           rq_majortimeo;  /* major timeout alarm */
  99         unsigned long           rq_timeout;     /* Current timeout value */
 100         ktime_t                 rq_rtt;         /* round-trip time */
 101         unsigned int            rq_retries;     /* # of retries */
 102         unsigned int            rq_connect_cookie;
 103                                                 /* A cookie used to track the
 104                                                    state of the transport
 105                                                    connection */
 106
 107         /*
 108          * Partial send handling
 109          */
 110         u32                     rq_bytes_sent;  /* Bytes we have sent */
 111
 112         ktime_t                 rq_xtime;       /* transmit time stamp */
 113         int                     rq_ntrans;
 114
 115 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 116         struct list_head        rq_bc_list;     /* Callback service list */
 117         unsigned long           rq_bc_pa_state; /* Backchannel prealloc state */
 118         struct list_head        rq_bc_pa_list;  /* Backchannel prealloc list */
 119 #endif /* CONFIG_SUNRPC_BACKCHANEL */
 120 };
 121 #define rq_svec                 rq_snd_buf.head
 122 #define rq_slen                 rq_snd_buf.len
 123
 124 struct rpc_xprt_ops {
 125         void            (*set_buffer_size)(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize);
 126         int             (*reserve_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
 127         void            (*release_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
 128         void            (*alloc_slot)(struct rpc_xprt *xprt, struct rpc_task *task);
 129         void            (*rpcbind)(struct rpc_task *task);
 130         void            (*set_port)(struct rpc_xprt *xprt, unsigned short port);
 131         void            (*connect)(struct rpc_xprt *xprt, struct rpc_task *task);
 132         int             (*buf_alloc)(struct rpc_task *task);
 133         void            (*buf_free)(struct rpc_task *task);
 134         int             (*send_request)(struct rpc_task *task);
 135         void            (*set_retrans_timeout)(struct rpc_task *task);
 136         void            (*timer)(struct rpc_xprt *xprt, struct rpc_task *task);
 137         void            (*release_request)(struct rpc_task *task);
 138         void            (*close)(struct rpc_xprt *xprt);
 139         void            (*destroy)(struct rpc_xprt *xprt);
 140         void            (*set_connect_timeout)(struct rpc_xprt *xprt,
 141                                         unsigned long connect_timeout,
 142                                         unsigned long reconnect_timeout);
 143         void            (*print_stats)(struct rpc_xprt *xprt, struct seq_file *seq);
 144         int             (*enable_swap)(struct rpc_xprt *xprt);
 145         void            (*disable_swap)(struct rpc_xprt *xprt);
 146         void            (*inject_disconnect)(struct rpc_xprt *xprt);
 147         int             (*bc_setup)(struct rpc_xprt *xprt,
 148                                     unsigned int min_reqs);
 149         int             (*bc_up)(struct svc_serv *serv, struct net *net);
 150         size_t          (*bc_maxpayload)(struct rpc_xprt *xprt);
 151         void            (*bc_free_rqst)(struct rpc_rqst *rqst);
 152         void            (*bc_destroy)(struct rpc_xprt *xprt,
 153                                       unsigned int max_reqs);
 154 };
 155
 156 /*
 157  * RPC transport identifiers
 158  *
 159  * To preserve compatibility with the historical use of raw IP protocol
 160  * id's for transport selection, UDP and TCP identifiers are specified
 161  * with the previous values. No such restriction exists for new transports,
 162  * except that they may not collide with these values (17 and 6,
 163  * respectively).
 164  */
 165 #define XPRT_TRANSPORT_BC       (1 << 31)
 166 enum xprt_transports {
 167         XPRT_TRANSPORT_UDP      = IPPROTO_UDP,
 168         XPRT_TRANSPORT_TCP      = IPPROTO_TCP,
 169         XPRT_TRANSPORT_BC_TCP   = IPPROTO_TCP | XPRT_TRANSPORT_BC,
 170         XPRT_TRANSPORT_RDMA     = 256,
 171         XPRT_TRANSPORT_BC_RDMA  = XPRT_TRANSPORT_RDMA | XPRT_TRANSPORT_BC,
 172         XPRT_TRANSPORT_LOCAL    = 257,
 173 };
 174
 175 struct rpc_xprt {
 176         struct kref             kref;           /* Reference count */
 177         struct rpc_xprt_ops *   ops;            /* transport methods */
 178
 179         const struct rpc_timeout *timeout;      /* timeout parms */
 180         struct sockaddr_storage addr;           /* server address */
 181         size_t                  addrlen;        /* size of server address */
 182         int                     prot;           /* IP protocol */
 183
 184         unsigned long           cong;           /* current congestion */
 185         unsigned long           cwnd;           /* congestion window */
 186
 187         size_t                  max_payload;    /* largest RPC payload size,
 188                                                    in bytes */
 189         unsigned int            tsh_size;       /* size of transport specific
 190                                                    header */
 191
 192         struct rpc_wait_queue   binding;        /* requests waiting on rpcbind */
 193         struct rpc_wait_queue   sending;        /* requests waiting to send */
 194         struct rpc_wait_queue   pending;        /* requests in flight */
 195         struct rpc_wait_queue   backlog;        /* waiting for slot */
 196         struct list_head        free;           /* free slots */
 197         unsigned int            max_reqs;       /* max number of slots */
 198         unsigned int            min_reqs;       /* min number of slots */
 199         atomic_t                num_reqs;       /* total slots */
 200         unsigned long           state;          /* transport state */
 201         unsigned char           resvport   : 1; /* use a reserved port */
 202         atomic_t                swapper;        /* we're swapping over this
 203                                                    transport */
 204         unsigned int            bind_index;     /* bind function index */
 205
 206         /*
 207          * Multipath
 208          */
 209         struct list_head        xprt_switch;
 210
 211         /*
 212          * Connection of transports
 213          */
 214         unsigned long           bind_timeout,
 215                                 reestablish_timeout;
 216         unsigned int            connect_cookie; /* A cookie that gets bumped
 217                                                    every time the transport
 218                                                    is reconnected */
 219
 220         /*
 221          * Disconnection of idle transports
 222          */
 223         struct work_struct      task_cleanup;
 224         struct timer_list       timer;
 225         unsigned long           last_used,
 226                                 idle_timeout,
 227                                 connect_timeout,
 228                                 max_reconnect_timeout;
 229
 230         /*
 231          * Send stuff
 232          */
 233         spinlock_t              transport_lock; /* lock transport info */
 234         spinlock_t              reserve_lock;   /* lock slot table */
 235         u32                     xid;            /* Next XID value to use */
 236         struct rpc_task *       snd_task;       /* Task blocked in send */
 237         struct svc_xprt         *bc_xprt;       /* NFSv4.1 backchannel */
 238 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 239         struct svc_serv         *bc_serv;       /* The RPC service which will */
 240                                                 /* process the callback */
 241         int                     bc_alloc_count; /* Total number of preallocs */
 242         atomic_t                bc_free_slots;
 243         spinlock_t              bc_pa_lock;     /* Protects the preallocated
 244                                                  * items */
 245         struct list_head        bc_pa_list;     /* List of preallocated
 246                                                  * backchannel rpc_rqst's */
 247 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
 248         struct list_head        recv;
 249
 250         struct {
 251                 unsigned long           bind_count,     /* total number of binds */
 252                                         connect_count,  /* total number of connects */
 253                                         connect_start,  /* connect start timestamp */
 254                                         connect_time,   /* jiffies waiting for connect */
 255                                         sends,          /* how many complete requests */
 256                                         recvs,          /* how many complete requests */
 257                                         bad_xids,       /* lookup_rqst didn't find XID */
 258                                         max_slots;      /* max rpc_slots used */
 259
 260                 unsigned long long      req_u,          /* average requests on the wire */
 261                                         bklog_u,        /* backlog queue utilization */
 262                                         sending_u,      /* send q utilization */
 263                                         pending_u;      /* pend q utilization */
 264         } stat;
 265
 266         struct net              *xprt_net;
 267         const char              *servername;
 268         const char              *address_strings[RPC_DISPLAY_MAX];
 269 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 270         struct dentry           *debugfs;               /* debugfs directory */
 271         atomic_t                inject_disconnect;
 272 #endif
 273         struct rcu_head         rcu;
 274 };
 275
 276 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 277 /*
 278  * Backchannel flags
 279  */
 280 #define RPC_BC_PA_IN_USE        0x0001          /* Preallocated backchannel */
 281                                                 /* buffer in use */
 282 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
 283
 284 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 285 static inline int bc_prealloc(struct rpc_rqst *req)
 286 {
 287         return test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
 288 }
 289 #else
 290 static inline int bc_prealloc(struct rpc_rqst *req)
 291 {
 292         return 0;
 293 }
 294 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
 295
 296 #define XPRT_CREATE_INFINITE_SLOTS      (1U)
 297 #define XPRT_CREATE_NO_IDLE_TIMEOUT     (1U << 1)
 298
 299 struct xprt_create {
 300         int                     ident;          /* XPRT_TRANSPORT identifier */
 301         struct net *            net;
 302         struct sockaddr *       srcaddr;        /* optional local address */
 303         struct sockaddr *       dstaddr;        /* remote peer address */
 304         size_t                  addrlen;
 305         const char              *servername;
 306         struct svc_xprt         *bc_xprt;       /* NFSv4.1 backchannel */
 307         struct rpc_xprt_switch  *bc_xps;
 308         unsigned int            flags;
 309 };
 310
 311 struct xprt_class {
 312         struct list_head        list;
 313         int                     ident;          /* XPRT_TRANSPORT identifier */
 314         struct rpc_xprt *       (*setup)(struct xprt_create *);
 315         struct module           *owner;
 316         char                    name[32];
 317 };
 318
 319 /*
 320  * Generic internal transport functions
 321  */
 322 struct rpc_xprt         *xprt_create_transport(struct xprt_create *args);
 323 void                    xprt_connect(struct rpc_task *task);
 324 void                    xprt_reserve(struct rpc_task *task);
 325 void                    xprt_retry_reserve(struct rpc_task *task);
 326 int                     xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
 327 int                     xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
 328 void                    xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
 329 void                    xprt_lock_and_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
 330 bool                    xprt_prepare_transmit(struct rpc_task *task);
 331 void                    xprt_transmit(struct rpc_task *task);
 332 void                    xprt_end_transmit(struct rpc_task *task);
 333 int                     xprt_adjust_timeout(struct rpc_rqst *req);
 334 void                    xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
 335 void                    xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
 336 void                    xprt_release(struct rpc_task *task);
 337 struct rpc_xprt *       xprt_get(struct rpc_xprt *xprt);
 338 void                    xprt_put(struct rpc_xprt *xprt);
 339 struct rpc_xprt *       xprt_alloc(struct net *net, size_t size,
 340                                 unsigned int num_prealloc,
 341                                 unsigned int max_req);
 342 void                    xprt_free(struct rpc_xprt *);
 343
 344 static inline __be32 *xprt_skip_transport_header(struct rpc_xprt *xprt, __be32 *p)
 345 {
 346         return p + xprt->tsh_size;
 347 }
 348
 349 static inline int
 350 xprt_enable_swap(struct rpc_xprt *xprt)
 351 {
 352         return xprt->ops->enable_swap(xprt);
 353 }
 354
 355 static inline void
 356 xprt_disable_swap(struct rpc_xprt *xprt)
 357 {
 358         xprt->ops->disable_swap(xprt);
 359 }
 360
 361 /*
 362  * Transport switch helper functions
 363  */
 364 int                     xprt_register_transport(struct xprt_class *type);
 365 int                     xprt_unregister_transport(struct xprt_class *type);
 366 int                     xprt_load_transport(const char *);
 367 void                    xprt_set_retrans_timeout_def(struct rpc_task *task);
 368 void                    xprt_set_retrans_timeout_rtt(struct rpc_task *task);
 369 void                    xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status);
 370 void                    xprt_wait_for_buffer_space(struct rpc_task *task, rpc_action action);
 371 void                    xprt_write_space(struct rpc_xprt *xprt);
 372 void                    xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result);
 373 struct rpc_rqst *       xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid);
 374 void                    xprt_complete_rqst(struct rpc_task *task, int copied);
 375 void                    xprt_release_rqst_cong(struct rpc_task *task);
 376 void                    xprt_disconnect_done(struct rpc_xprt *xprt);
 377 void                    xprt_force_disconnect(struct rpc_xprt *xprt);
 378 void                    xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie);
 379
 380 bool                    xprt_lock_connect(struct rpc_xprt *, struct rpc_task *, void *);
 381 void                    xprt_unlock_connect(struct rpc_xprt *, void *);
 382
 383 /*
 384  * Reserved bit positions in xprt->state
 385  */
 386 #define XPRT_LOCKED             (0)
 387 #define XPRT_CONNECTED          (1)
 388 #define XPRT_CONNECTING         (2)
 389 #define XPRT_CLOSE_WAIT         (3)
 390 #define XPRT_BOUND              (4)
 391 #define XPRT_BINDING            (5)
 392 #define XPRT_CLOSING            (6)
 393 #define XPRT_CONGESTED          (9)
 394
 395 static inline void xprt_set_connected(struct rpc_xprt *xprt)
 396 {
 397         set_bit(XPRT_CONNECTED, &xprt->state);
 398 }
 399
 400 static inline void xprt_clear_connected(struct rpc_xprt *xprt)
 401 {
 402         clear_bit(XPRT_CONNECTED, &xprt->state);
 403 }
 404
 405 static inline int xprt_connected(struct rpc_xprt *xprt)
 406 {
 407         return test_bit(XPRT_CONNECTED, &xprt->state);
 408 }
 409
 410 static inline int xprt_test_and_set_connected(struct rpc_xprt *xprt)
 411 {
 412         return test_and_set_bit(XPRT_CONNECTED, &xprt->state);
 413 }
 414
 415 static inline int xprt_test_and_clear_connected(struct rpc_xprt *xprt)
 416 {
 417         return test_and_clear_bit(XPRT_CONNECTED, &xprt->state);
 418 }
 419
 420 static inline void xprt_clear_connecting(struct rpc_xprt *xprt)
 421 {
 422         smp_mb__before_atomic();
 423         clear_bit(XPRT_CONNECTING, &xprt->state);
 424         smp_mb__after_atomic();
 425 }
 426
 427 static inline int xprt_connecting(struct rpc_xprt *xprt)
 428 {
 429         return test_bit(XPRT_CONNECTING, &xprt->state);
 430 }
 431
 432 static inline int xprt_test_and_set_connecting(struct rpc_xprt *xprt)
 433 {
 434         return test_and_set_bit(XPRT_CONNECTING, &xprt->state);
 435 }
 436
 437 static inline void xprt_set_bound(struct rpc_xprt *xprt)
 438 {
 439         test_and_set_bit(XPRT_BOUND, &xprt->state);
 440 }
 441
 442 static inline int xprt_bound(struct rpc_xprt *xprt)
 443 {
 444         return test_bit(XPRT_BOUND, &xprt->state);
 445 }
 446
 447 static inline void xprt_clear_bound(struct rpc_xprt *xprt)
 448 {
 449         clear_bit(XPRT_BOUND, &xprt->state);
 450 }
 451
 452 static inline void xprt_clear_binding(struct rpc_xprt *xprt)
 453 {
 454         smp_mb__before_atomic();
 455         clear_bit(XPRT_BINDING, &xprt->state);
 456         smp_mb__after_atomic();
 457 }
 458
 459 static inline int xprt_test_and_set_binding(struct rpc_xprt *xprt)
 460 {
 461         return test_and_set_bit(XPRT_BINDING, &xprt->state);
 462 }
 463
 464 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 465 extern unsigned int rpc_inject_disconnect;
 466 static inline void xprt_inject_disconnect(struct rpc_xprt *xprt)
 467 {
 468         if (!rpc_inject_disconnect)
 469                 return;
 470         if (atomic_dec_return(&xprt->inject_disconnect))
 471                 return;
 472         atomic_set(&xprt->inject_disconnect, rpc_inject_disconnect);
 473         xprt->ops->inject_disconnect(xprt);
 474 }
 475 #else
 476 static inline void xprt_inject_disconnect(struct rpc_xprt *xprt)
 477 {
 478 }
 479 #endif
 480
 481 #endif /* __KERNEL__*/
 482
 483 #endif /* _LINUX_SUNRPC_XPRT_H */