include/linux/sunrpc/xprt.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  *  linux/include/linux/sunrpc/xprt.h
   4  *
   5  *  Declarations for the RPC transport interface.
   6  *
   7  *  Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
   8  */
   9
  10 #ifndef _LINUX_SUNRPC_XPRT_H
  11 #define _LINUX_SUNRPC_XPRT_H
  12
  13 #include <linux/uio.h>
  14 #include <linux/socket.h>
  15 #include <linux/in.h>
  16 #include <linux/ktime.h>
  17 #include <linux/kref.h>
  18 #include <linux/sunrpc/sched.h>
  19 #include <linux/sunrpc/xdr.h>
  20 #include <linux/sunrpc/msg_prot.h>
  21
  22 #ifdef __KERNEL__
  23
  24 #define RPC_MIN_SLOT_TABLE      (2U)
  25 #define RPC_DEF_SLOT_TABLE      (16U)
  26 #define RPC_MAX_SLOT_TABLE_LIMIT        (65536U)
  27 #define RPC_MAX_SLOT_TABLE      RPC_MAX_SLOT_TABLE_LIMIT
  28
  29 #define RPC_CWNDSHIFT           (8U)
  30 #define RPC_CWNDSCALE           (1U << RPC_CWNDSHIFT)
  31 #define RPC_INITCWND            RPC_CWNDSCALE
  32 #define RPC_MAXCWND(xprt)       ((xprt)->max_reqs << RPC_CWNDSHIFT)
  33 #define RPCXPRT_CONGESTED(xprt) ((xprt)->cong >= (xprt)->cwnd)
  34
  35 /*
  36  * This describes a timeout strategy
  37  */
  38 struct rpc_timeout {
  39         unsigned long           to_initval,             /* initial timeout */
  40                                 to_maxval,              /* max timeout */
  41                                 to_increment;           /* if !exponential */
  42         unsigned int            to_retries;             /* max # of retries */
  43         unsigned char           to_exponential;
  44 };
  45
  46 enum rpc_display_format_t {
  47         RPC_DISPLAY_ADDR = 0,
  48         RPC_DISPLAY_PORT,
  49         RPC_DISPLAY_PROTO,
  50         RPC_DISPLAY_HEX_ADDR,
  51         RPC_DISPLAY_HEX_PORT,
  52         RPC_DISPLAY_NETID,
  53         RPC_DISPLAY_MAX,
  54 };
  55
  56 struct rpc_task;
  57 struct rpc_xprt;
  58 struct seq_file;
  59 struct svc_serv;
  60 struct net;
  61
  62 /*
  63  * This describes a complete RPC request
  64  */
  65 struct rpc_rqst {
  66         /*
  67          * This is the user-visible part
  68          */
  69         struct rpc_xprt *       rq_xprt;                /* RPC client */
  70         struct xdr_buf          rq_snd_buf;             /* send buffer */
  71         struct xdr_buf          rq_rcv_buf;             /* recv buffer */
  72
  73         /*
  74          * This is the private part
  75          */
  76         struct rpc_task *       rq_task;        /* RPC task data */
  77         struct rpc_cred *       rq_cred;        /* Bound cred */
  78         __be32                  rq_xid;         /* request XID */
  79         int                     rq_cong;        /* has incremented xprt->cong */
  80         u32                     rq_seqno;       /* gss seq no. used on req. */
  81         int                     rq_enc_pages_num;
  82         struct page             **rq_enc_pages; /* scratch pages for use by
  83                                                    gss privacy code */
  84         void (*rq_release_snd_buf)(struct rpc_rqst *); /* release rq_enc_pages */
  85         struct list_head        rq_list;
  86
  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            (*free_slot)(struct rpc_xprt *xprt,
 130                                      struct rpc_rqst *req);
 131         void            (*rpcbind)(struct rpc_task *task);
 132         void            (*set_port)(struct rpc_xprt *xprt, unsigned short port);
 133         void            (*connect)(struct rpc_xprt *xprt, struct rpc_task *task);
 134         int             (*buf_alloc)(struct rpc_task *task);
 135         void            (*buf_free)(struct rpc_task *task);
 136         int             (*send_request)(struct rpc_task *task);
 137         void            (*set_retrans_timeout)(struct rpc_task *task);
 138         void            (*timer)(struct rpc_xprt *xprt, struct rpc_task *task);
 139         void            (*release_request)(struct rpc_task *task);
 140         void            (*close)(struct rpc_xprt *xprt);
 141         void            (*destroy)(struct rpc_xprt *xprt);
 142         void            (*set_connect_timeout)(struct rpc_xprt *xprt,
 143                                         unsigned long connect_timeout,
 144                                         unsigned long reconnect_timeout);
 145         void            (*print_stats)(struct rpc_xprt *xprt, struct seq_file *seq);
 146         int             (*enable_swap)(struct rpc_xprt *xprt);
 147         void            (*disable_swap)(struct rpc_xprt *xprt);
 148         void            (*inject_disconnect)(struct rpc_xprt *xprt);
 149         int             (*bc_setup)(struct rpc_xprt *xprt,
 150                                     unsigned int min_reqs);
 151         int             (*bc_up)(struct svc_serv *serv, struct net *net);
 152         size_t          (*bc_maxpayload)(struct rpc_xprt *xprt);
 153         void            (*bc_free_rqst)(struct rpc_rqst *rqst);
 154         void            (*bc_destroy)(struct rpc_xprt *xprt,
 155                                       unsigned int max_reqs);
 156 };
 157
 158 /*
 159  * RPC transport identifiers
 160  *
 161  * To preserve compatibility with the historical use of raw IP protocol
 162  * id's for transport selection, UDP and TCP identifiers are specified
 163  * with the previous values. No such restriction exists for new transports,
 164  * except that they may not collide with these values (17 and 6,
 165  * respectively).
 166  */
 167 #define XPRT_TRANSPORT_BC       (1 << 31)
 168 enum xprt_transports {
 169         XPRT_TRANSPORT_UDP      = IPPROTO_UDP,
 170         XPRT_TRANSPORT_TCP      = IPPROTO_TCP,
 171         XPRT_TRANSPORT_BC_TCP   = IPPROTO_TCP | XPRT_TRANSPORT_BC,
 172         XPRT_TRANSPORT_RDMA     = 256,
 173         XPRT_TRANSPORT_BC_RDMA  = XPRT_TRANSPORT_RDMA | XPRT_TRANSPORT_BC,
 174         XPRT_TRANSPORT_LOCAL    = 257,
 175 };
 176
 177 struct rpc_xprt {
 178         struct kref             kref;           /* Reference count */
 179         const struct rpc_xprt_ops *ops;         /* transport methods */
 180
 181         const struct rpc_timeout *timeout;      /* timeout parms */
 182         struct sockaddr_storage addr;           /* server address */
 183         size_t                  addrlen;        /* size of server address */
 184         int                     prot;           /* IP protocol */
 185
 186         unsigned long           cong;           /* current congestion */
 187         unsigned long           cwnd;           /* congestion window */
 188
 189         size_t                  max_payload;    /* largest RPC payload size,
 190                                                    in bytes */
 191         unsigned int            tsh_size;       /* size of transport specific
 192                                                    header */
 193
 194         struct rpc_wait_queue   binding;        /* requests waiting on rpcbind */
 195         struct rpc_wait_queue   sending;        /* requests waiting to send */
 196         struct rpc_wait_queue   pending;        /* requests in flight */
 197         struct rpc_wait_queue   backlog;        /* waiting for slot */
 198         struct list_head        free;           /* free slots */
 199         unsigned int            max_reqs;       /* max number of slots */
 200         unsigned int            min_reqs;       /* min number of slots */
 201         unsigned int            num_reqs;       /* total slots */
 202         unsigned long           state;          /* transport state */
 203         unsigned char           resvport   : 1; /* use a reserved port */
 204         atomic_t                swapper;        /* we're swapping over this
 205                                                    transport */
 206         unsigned int            bind_index;     /* bind function index */
 207
 208         /*
 209          * Multipath
 210          */
 211         struct list_head        xprt_switch;
 212
 213         /*
 214          * Connection of transports
 215          */
 216         unsigned long           bind_timeout,
 217                                 reestablish_timeout;
 218         unsigned int            connect_cookie; /* A cookie that gets bumped
 219                                                    every time the transport
 220                                                    is reconnected */
 221
 222         /*
 223          * Disconnection of idle transports
 224          */
 225         struct work_struct      task_cleanup;
 226         struct timer_list       timer;
 227         unsigned long           last_used,
 228                                 idle_timeout,
 229                                 connect_timeout,
 230                                 max_reconnect_timeout;
 231
 232         /*
 233          * Send stuff
 234          */
 235         spinlock_t              transport_lock; /* lock transport info */
 236         spinlock_t              reserve_lock;   /* lock slot table */
 237         spinlock_t              recv_lock;      /* lock receive list */
 238         u32                     xid;            /* Next XID value to use */
 239         struct rpc_task *       snd_task;       /* Task blocked in send */
 240         struct svc_xprt         *bc_xprt;       /* NFSv4.1 backchannel */
 241 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 242         struct svc_serv         *bc_serv;       /* The RPC service which will */
 243                                                 /* process the callback */
 244         int                     bc_alloc_count; /* Total number of preallocs */
 245         atomic_t                bc_free_slots;
 246         spinlock_t              bc_pa_lock;     /* Protects the preallocated
 247                                                  * items */
 248         struct list_head        bc_pa_list;     /* List of preallocated
 249                                                  * backchannel rpc_rqst's */
 250 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
 251         struct list_head        recv;
 252
 253         struct {
 254                 unsigned long           bind_count,     /* total number of binds */
 255                                         connect_count,  /* total number of connects */
 256                                         connect_start,  /* connect start timestamp */
 257                                         connect_time,   /* jiffies waiting for connect */
 258                                         sends,          /* how many complete requests */
 259                                         recvs,          /* how many complete requests */
 260                                         bad_xids,       /* lookup_rqst didn't find XID */
 261                                         max_slots;      /* max rpc_slots used */
 262
 263                 unsigned long long      req_u,          /* average requests on the wire */
 264                                         bklog_u,        /* backlog queue utilization */
 265                                         sending_u,      /* send q utilization */
 266                                         pending_u;      /* pend q utilization */
 267         } stat;
 268
 269         struct net              *xprt_net;
 270         const char              *servername;
 271         const char              *address_strings[RPC_DISPLAY_MAX];
 272 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 273         struct dentry           *debugfs;               /* debugfs directory */
 274         atomic_t                inject_disconnect;
 275 #endif
 276         struct rcu_head         rcu;
 277 };
 278
 279 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 280 /*
 281  * Backchannel flags
 282  */
 283 #define RPC_BC_PA_IN_USE        0x0001          /* Preallocated backchannel */
 284                                                 /* buffer in use */
 285 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
 286
 287 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 288 static inline int bc_prealloc(struct rpc_rqst *req)
 289 {
 290         return test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
 291 }
 292 #else
 293 static inline int bc_prealloc(struct rpc_rqst *req)
 294 {
 295         return 0;
 296 }
 297 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
 298
 299 #define XPRT_CREATE_INFINITE_SLOTS      (1U)
 300 #define XPRT_CREATE_NO_IDLE_TIMEOUT     (1U << 1)
 301
 302 struct xprt_create {
 303         int                     ident;          /* XPRT_TRANSPORT identifier */
 304         struct net *            net;
 305         struct sockaddr *       srcaddr;        /* optional local address */
 306         struct sockaddr *       dstaddr;        /* remote peer address */
 307         size_t                  addrlen;
 308         const char              *servername;
 309         struct svc_xprt         *bc_xprt;       /* NFSv4.1 backchannel */
 310         struct rpc_xprt_switch  *bc_xps;
 311         unsigned int            flags;
 312 };
 313
 314 struct xprt_class {
 315         struct list_head        list;
 316         int                     ident;          /* XPRT_TRANSPORT identifier */
 317         struct rpc_xprt *       (*setup)(struct xprt_create *);
 318         struct module           *owner;
 319         char                    name[32];
 320         const char *            netid[];
 321 };
 322
 323 /*
 324  * Generic internal transport functions
 325  */
 326 struct rpc_xprt         *xprt_create_transport(struct xprt_create *args);
 327 void                    xprt_connect(struct rpc_task *task);
 328 void                    xprt_reserve(struct rpc_task *task);
 329 void                    xprt_retry_reserve(struct rpc_task *task);
 330 int                     xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
 331 int                     xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
 332 void                    xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
 333 void                    xprt_free_slot(struct rpc_xprt *xprt,
 334                                        struct rpc_rqst *req);
 335 void                    xprt_lock_and_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
 336 bool                    xprt_prepare_transmit(struct rpc_task *task);
 337 void                    xprt_transmit(struct rpc_task *task);
 338 void                    xprt_end_transmit(struct rpc_task *task);
 339 int                     xprt_adjust_timeout(struct rpc_rqst *req);
 340 void                    xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
 341 void                    xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
 342 void                    xprt_release(struct rpc_task *task);
 343 struct rpc_xprt *       xprt_get(struct rpc_xprt *xprt);
 344 void                    xprt_put(struct rpc_xprt *xprt);
 345 struct rpc_xprt *       xprt_alloc(struct net *net, size_t size,
 346                                 unsigned int num_prealloc,
 347                                 unsigned int max_req);
 348 void                    xprt_free(struct rpc_xprt *);
 349
 350 static inline __be32 *xprt_skip_transport_header(struct rpc_xprt *xprt, __be32 *p)
 351 {
 352         return p + xprt->tsh_size;
 353 }
 354
 355 static inline int
 356 xprt_enable_swap(struct rpc_xprt *xprt)
 357 {
 358         return xprt->ops->enable_swap(xprt);
 359 }
 360
 361 static inline void
 362 xprt_disable_swap(struct rpc_xprt *xprt)
 363 {
 364         xprt->ops->disable_swap(xprt);
 365 }
 366
 367 /*
 368  * Transport switch helper functions
 369  */
 370 int                     xprt_register_transport(struct xprt_class *type);
 371 int                     xprt_unregister_transport(struct xprt_class *type);
 372 int                     xprt_load_transport(const char *);
 373 void                    xprt_set_retrans_timeout_def(struct rpc_task *task);
 374 void                    xprt_set_retrans_timeout_rtt(struct rpc_task *task);
 375 void                    xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status);
 376 void                    xprt_wait_for_buffer_space(struct rpc_task *task, rpc_action action);
 377 void                    xprt_write_space(struct rpc_xprt *xprt);
 378 void                    xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result);
 379 struct rpc_rqst *       xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid);
 380 void                    xprt_update_rtt(struct rpc_task *task);
 381 void                    xprt_complete_rqst(struct rpc_task *task, int copied);
 382 void                    xprt_pin_rqst(struct rpc_rqst *req);
 383 void                    xprt_unpin_rqst(struct rpc_rqst *req);
 384 void                    xprt_release_rqst_cong(struct rpc_task *task);
 385 void                    xprt_disconnect_done(struct rpc_xprt *xprt);
 386 void                    xprt_force_disconnect(struct rpc_xprt *xprt);
 387 void                    xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie);
 388
 389 bool                    xprt_lock_connect(struct rpc_xprt *, struct rpc_task *, void *);
 390 void                    xprt_unlock_connect(struct rpc_xprt *, void *);
 391
 392 /*
 393  * Reserved bit positions in xprt->state
 394  */
 395 #define XPRT_LOCKED             (0)
 396 #define XPRT_CONNECTED          (1)
 397 #define XPRT_CONNECTING         (2)
 398 #define XPRT_CLOSE_WAIT         (3)
 399 #define XPRT_BOUND              (4)
 400 #define XPRT_BINDING            (5)
 401 #define XPRT_CLOSING            (6)
 402 #define XPRT_CONGESTED          (9)
 403
 404 static inline void xprt_set_connected(struct rpc_xprt *xprt)
 405 {
 406         set_bit(XPRT_CONNECTED, &xprt->state);
 407 }
 408
 409 static inline void xprt_clear_connected(struct rpc_xprt *xprt)
 410 {
 411         clear_bit(XPRT_CONNECTED, &xprt->state);
 412 }
 413
 414 static inline int xprt_connected(struct rpc_xprt *xprt)
 415 {
 416         return test_bit(XPRT_CONNECTED, &xprt->state);
 417 }
 418
 419 static inline int xprt_test_and_set_connected(struct rpc_xprt *xprt)
 420 {
 421         return test_and_set_bit(XPRT_CONNECTED, &xprt->state);
 422 }
 423
 424 static inline int xprt_test_and_clear_connected(struct rpc_xprt *xprt)
 425 {
 426         return test_and_clear_bit(XPRT_CONNECTED, &xprt->state);
 427 }
 428
 429 static inline void xprt_clear_connecting(struct rpc_xprt *xprt)
 430 {
 431         smp_mb__before_atomic();
 432         clear_bit(XPRT_CONNECTING, &xprt->state);
 433         smp_mb__after_atomic();
 434 }
 435
 436 static inline int xprt_connecting(struct rpc_xprt *xprt)
 437 {
 438         return test_bit(XPRT_CONNECTING, &xprt->state);
 439 }
 440
 441 static inline int xprt_test_and_set_connecting(struct rpc_xprt *xprt)
 442 {
 443         return test_and_set_bit(XPRT_CONNECTING, &xprt->state);
 444 }
 445
 446 static inline int xprt_close_wait(struct rpc_xprt *xprt)
 447 {
 448         return test_bit(XPRT_CLOSE_WAIT, &xprt->state);
 449 }
 450
 451 static inline void xprt_set_bound(struct rpc_xprt *xprt)
 452 {
 453         test_and_set_bit(XPRT_BOUND, &xprt->state);
 454 }
 455
 456 static inline int xprt_bound(struct rpc_xprt *xprt)
 457 {
 458         return test_bit(XPRT_BOUND, &xprt->state);
 459 }
 460
 461 static inline void xprt_clear_bound(struct rpc_xprt *xprt)
 462 {
 463         clear_bit(XPRT_BOUND, &xprt->state);
 464 }
 465
 466 static inline void xprt_clear_binding(struct rpc_xprt *xprt)
 467 {
 468         smp_mb__before_atomic();
 469         clear_bit(XPRT_BINDING, &xprt->state);
 470         smp_mb__after_atomic();
 471 }
 472
 473 static inline int xprt_test_and_set_binding(struct rpc_xprt *xprt)
 474 {
 475         return test_and_set_bit(XPRT_BINDING, &xprt->state);
 476 }
 477
 478 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 479 extern unsigned int rpc_inject_disconnect;
 480 static inline void xprt_inject_disconnect(struct rpc_xprt *xprt)
 481 {
 482         if (!rpc_inject_disconnect)
 483                 return;
 484         if (atomic_dec_return(&xprt->inject_disconnect))
 485                 return;
 486         atomic_set(&xprt->inject_disconnect, rpc_inject_disconnect);
 487         xprt->ops->inject_disconnect(xprt);
 488 }
 489 #else
 490 static inline void xprt_inject_disconnect(struct rpc_xprt *xprt)
 491 {
 492 }
 493 #endif
 494
 495 #endif /* __KERNEL__*/
 496
 497 #endif /* _LINUX_SUNRPC_XPRT_H */