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 <[email protected]> 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 #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 #define RPC_CWNDSHIFT (8U) 28 #define RPC_CWNDSCALE (1U << RPC_CWNDSHIFT) 29 #define RPC_INITCWND RPC_CWNDSCALE 30 #define RPC_MAXCWND(xprt) ((xprt)->max_reqs << RPC_CWNDSHIFT) 31 #define RPCXPRT_CONGESTED(xprt) ((xprt)->cong >= (xprt)->cwnd) 32 33 /* 34 * This describes a timeout strategy 35 */ 36 struct rpc_timeout { 37 unsigned long to_initval, /* initial timeout */ 38 to_maxval, /* max timeout */ 39 to_increment; /* if !exponential */ 40 unsigned int to_retries; /* max # of retries */ 41 unsigned char to_exponential; 42 }; 43 44 enum rpc_display_format_t { 45 RPC_DISPLAY_ADDR = 0, 46 RPC_DISPLAY_PORT, 47 RPC_DISPLAY_PROTO, 48 RPC_DISPLAY_HEX_ADDR, 49 RPC_DISPLAY_HEX_PORT, 50 RPC_DISPLAY_NETID, 51 RPC_DISPLAY_MAX, 52 }; 53 54 struct rpc_task; 55 struct rpc_xprt; 56 struct seq_file; 57 struct svc_serv; 58 struct net; 59 60 /* 61 * This describes a complete RPC request 62 */ 63 struct rpc_rqst { 64 /* 65 * This is the user-visible part 66 */ 67 struct rpc_xprt * rq_xprt; /* RPC client */ 68 struct xdr_buf rq_snd_buf; /* send buffer */ 69 struct xdr_buf rq_rcv_buf; /* recv buffer */ 70 71 /* 72 * This is the private part 73 */ 74 struct rpc_task * rq_task; /* RPC task data */ 75 struct rpc_cred * rq_cred; /* Bound cred */ 76 __be32 rq_xid; /* request XID */ 77 int rq_cong; /* has incremented xprt->cong */ 78 u32 rq_seqno; /* gss seq no. used on req. */ 79 int rq_enc_pages_num; 80 struct page **rq_enc_pages; /* scratch pages for use by 81 gss privacy code */ 82 void (*rq_release_snd_buf)(struct rpc_rqst *); /* release rq_enc_pages */ 83 84 union { 85 struct list_head rq_list; /* Slot allocation list */ 86 struct rb_node rq_recv; /* Receive queue */ 87 }; 88 89 struct list_head rq_xmit; /* Send queue */ 90 struct list_head rq_xmit2; /* Send queue */ 91 92 void *rq_buffer; /* Call XDR encode buffer */ 93 size_t rq_callsize; 94 void *rq_rbuffer; /* Reply XDR decode buffer */ 95 size_t rq_rcvsize; 96 size_t rq_xmit_bytes_sent; /* total bytes sent */ 97 size_t rq_reply_bytes_recvd; /* total reply bytes */ 98 /* received */ 99 100 struct xdr_buf rq_private_buf; /* The receive buffer 101 * used in the softirq. 102 */ 103 unsigned long rq_majortimeo; /* major timeout alarm */ 104 unsigned long rq_timeout; /* Current timeout value */ 105 ktime_t rq_rtt; /* round-trip time */ 106 unsigned int rq_retries; /* # of retries */ 107 unsigned int rq_connect_cookie; 108 /* A cookie used to track the 109 state of the transport 110 connection */ 111 atomic_t rq_pin; 112 113 /* 114 * Partial send handling 115 */ 116 u32 rq_bytes_sent; /* Bytes we have sent */ 117 118 ktime_t rq_xtime; /* transmit time stamp */ 119 int rq_ntrans; 120 121 #if defined(CONFIG_SUNRPC_BACKCHANNEL) 122 struct list_head rq_bc_list; /* Callback service list */ 123 unsigned long rq_bc_pa_state; /* Backchannel prealloc state */ 124 struct list_head rq_bc_pa_list; /* Backchannel prealloc list */ 125 #endif /* CONFIG_SUNRPC_BACKCHANEL */ 126 }; 127 #define rq_svec rq_snd_buf.head 128 #define rq_slen rq_snd_buf.len 129 130 struct rpc_xprt_ops { 131 void (*set_buffer_size)(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize); 132 int (*reserve_xprt)(struct rpc_xprt *xprt, struct rpc_task *task); 133 void (*release_xprt)(struct rpc_xprt *xprt, struct rpc_task *task); 134 void (*alloc_slot)(struct rpc_xprt *xprt, struct rpc_task *task); 135 void (*free_slot)(struct rpc_xprt *xprt, 136 struct rpc_rqst *req); 137 void (*rpcbind)(struct rpc_task *task); 138 void (*set_port)(struct rpc_xprt *xprt, unsigned short port); 139 void (*connect)(struct rpc_xprt *xprt, struct rpc_task *task); 140 int (*buf_alloc)(struct rpc_task *task); 141 void (*buf_free)(struct rpc_task *task); 142 void (*prepare_request)(struct rpc_rqst *req); 143 int (*send_request)(struct rpc_rqst *req); 144 void (*wait_for_reply_request)(struct rpc_task *task); 145 void (*timer)(struct rpc_xprt *xprt, struct rpc_task *task); 146 void (*release_request)(struct rpc_task *task); 147 void (*close)(struct rpc_xprt *xprt); 148 void (*destroy)(struct rpc_xprt *xprt); 149 void (*set_connect_timeout)(struct rpc_xprt *xprt, 150 unsigned long connect_timeout, 151 unsigned long reconnect_timeout); 152 void (*print_stats)(struct rpc_xprt *xprt, struct seq_file *seq); 153 int (*enable_swap)(struct rpc_xprt *xprt); 154 void (*disable_swap)(struct rpc_xprt *xprt); 155 void (*inject_disconnect)(struct rpc_xprt *xprt); 156 int (*bc_setup)(struct rpc_xprt *xprt, 157 unsigned int min_reqs); 158 size_t (*bc_maxpayload)(struct rpc_xprt *xprt); 159 unsigned int (*bc_num_slots)(struct rpc_xprt *xprt); 160 void (*bc_free_rqst)(struct rpc_rqst *rqst); 161 void (*bc_destroy)(struct rpc_xprt *xprt, 162 unsigned int max_reqs); 163 }; 164 165 /* 166 * RPC transport identifiers 167 * 168 * To preserve compatibility with the historical use of raw IP protocol 169 * id's for transport selection, UDP and TCP identifiers are specified 170 * with the previous values. No such restriction exists for new transports, 171 * except that they may not collide with these values (17 and 6, 172 * respectively). 173 */ 174 #define XPRT_TRANSPORT_BC (1 << 31) 175 enum xprt_transports { 176 XPRT_TRANSPORT_UDP = IPPROTO_UDP, 177 XPRT_TRANSPORT_TCP = IPPROTO_TCP, 178 XPRT_TRANSPORT_BC_TCP = IPPROTO_TCP | XPRT_TRANSPORT_BC, 179 XPRT_TRANSPORT_RDMA = 256, 180 XPRT_TRANSPORT_BC_RDMA = XPRT_TRANSPORT_RDMA | XPRT_TRANSPORT_BC, 181 XPRT_TRANSPORT_LOCAL = 257, 182 }; 183 184 struct rpc_xprt { 185 struct kref kref; /* Reference count */ 186 const struct rpc_xprt_ops *ops; /* transport methods */ 187 188 const struct rpc_timeout *timeout; /* timeout parms */ 189 struct sockaddr_storage addr; /* server address */ 190 size_t addrlen; /* size of server address */ 191 int prot; /* IP protocol */ 192 193 unsigned long cong; /* current congestion */ 194 unsigned long cwnd; /* congestion window */ 195 196 size_t max_payload; /* largest RPC payload size, 197 in bytes */ 198 199 struct rpc_wait_queue binding; /* requests waiting on rpcbind */ 200 struct rpc_wait_queue sending; /* requests waiting to send */ 201 struct rpc_wait_queue pending; /* requests in flight */ 202 struct rpc_wait_queue backlog; /* waiting for slot */ 203 struct list_head free; /* free slots */ 204 unsigned int max_reqs; /* max number of slots */ 205 unsigned int min_reqs; /* min number of slots */ 206 unsigned int num_reqs; /* total slots */ 207 unsigned long state; /* transport state */ 208 unsigned char resvport : 1, /* use a reserved port */ 209 reuseport : 1; /* reuse port on reconnect */ 210 atomic_t swapper; /* we're swapping over this 211 transport */ 212 unsigned int bind_index; /* bind function index */ 213 214 /* 215 * Multipath 216 */ 217 struct list_head xprt_switch; 218 219 /* 220 * Connection of transports 221 */ 222 unsigned long bind_timeout, 223 reestablish_timeout; 224 unsigned int connect_cookie; /* A cookie that gets bumped 225 every time the transport 226 is reconnected */ 227 228 /* 229 * Disconnection of idle transports 230 */ 231 struct work_struct task_cleanup; 232 struct timer_list timer; 233 unsigned long last_used, 234 idle_timeout, 235 connect_timeout, 236 max_reconnect_timeout; 237 238 /* 239 * Send stuff 240 */ 241 atomic_long_t queuelen; 242 spinlock_t transport_lock; /* lock transport info */ 243 spinlock_t reserve_lock; /* lock slot table */ 244 spinlock_t queue_lock; /* send/receive queue lock */ 245 u32 xid; /* Next XID value to use */ 246 struct rpc_task * snd_task; /* Task blocked in send */ 247 248 struct list_head xmit_queue; /* Send queue */ 249 250 struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */ 251 #if defined(CONFIG_SUNRPC_BACKCHANNEL) 252 struct svc_serv *bc_serv; /* The RPC service which will */ 253 /* process the callback */ 254 unsigned int bc_alloc_max; 255 unsigned int bc_alloc_count; /* Total number of preallocs */ 256 atomic_t bc_slot_count; /* Number of allocated slots */ 257 spinlock_t bc_pa_lock; /* Protects the preallocated 258 * items */ 259 struct list_head bc_pa_list; /* List of preallocated 260 * backchannel rpc_rqst's */ 261 #endif /* CONFIG_SUNRPC_BACKCHANNEL */ 262 263 struct rb_root recv_queue; /* Receive queue */ 264 265 struct { 266 unsigned long bind_count, /* total number of binds */ 267 connect_count, /* total number of connects */ 268 connect_start, /* connect start timestamp */ 269 connect_time, /* jiffies waiting for connect */ 270 sends, /* how many complete requests */ 271 recvs, /* how many complete requests */ 272 bad_xids, /* lookup_rqst didn't find XID */ 273 max_slots; /* max rpc_slots used */ 274 275 unsigned long long req_u, /* average requests on the wire */ 276 bklog_u, /* backlog queue utilization */ 277 sending_u, /* send q utilization */ 278 pending_u; /* pend q utilization */ 279 } stat; 280 281 struct net *xprt_net; 282 const char *servername; 283 const char *address_strings[RPC_DISPLAY_MAX]; 284 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) 285 struct dentry *debugfs; /* debugfs directory */ 286 atomic_t inject_disconnect; 287 #endif 288 struct rcu_head rcu; 289 }; 290 291 #if defined(CONFIG_SUNRPC_BACKCHANNEL) 292 /* 293 * Backchannel flags 294 */ 295 #define RPC_BC_PA_IN_USE 0x0001 /* Preallocated backchannel */ 296 /* buffer in use */ 297 #endif /* CONFIG_SUNRPC_BACKCHANNEL */ 298 299 #if defined(CONFIG_SUNRPC_BACKCHANNEL) 300 static inline int bc_prealloc(struct rpc_rqst *req) 301 { 302 return test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state); 303 } 304 #else 305 static inline int bc_prealloc(struct rpc_rqst *req) 306 { 307 return 0; 308 } 309 #endif /* CONFIG_SUNRPC_BACKCHANNEL */ 310 311 #define XPRT_CREATE_INFINITE_SLOTS (1U) 312 #define XPRT_CREATE_NO_IDLE_TIMEOUT (1U << 1) 313 314 struct xprt_create { 315 int ident; /* XPRT_TRANSPORT identifier */ 316 struct net * net; 317 struct sockaddr * srcaddr; /* optional local address */ 318 struct sockaddr * dstaddr; /* remote peer address */ 319 size_t addrlen; 320 const char *servername; 321 struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */ 322 struct rpc_xprt_switch *bc_xps; 323 unsigned int flags; 324 }; 325 326 struct xprt_class { 327 struct list_head list; 328 int ident; /* XPRT_TRANSPORT identifier */ 329 struct rpc_xprt * (*setup)(struct xprt_create *); 330 struct module *owner; 331 char name[32]; 332 }; 333 334 /* 335 * Generic internal transport functions 336 */ 337 struct rpc_xprt *xprt_create_transport(struct xprt_create *args); 338 void xprt_connect(struct rpc_task *task); 339 unsigned long xprt_reconnect_delay(const struct rpc_xprt *xprt); 340 void xprt_reconnect_backoff(struct rpc_xprt *xprt, 341 unsigned long init_to); 342 void xprt_reserve(struct rpc_task *task); 343 void xprt_retry_reserve(struct rpc_task *task); 344 int xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task); 345 int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task); 346 void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task); 347 void xprt_free_slot(struct rpc_xprt *xprt, 348 struct rpc_rqst *req); 349 void xprt_request_prepare(struct rpc_rqst *req); 350 bool xprt_prepare_transmit(struct rpc_task *task); 351 void xprt_request_enqueue_transmit(struct rpc_task *task); 352 void xprt_request_enqueue_receive(struct rpc_task *task); 353 void xprt_request_wait_receive(struct rpc_task *task); 354 void xprt_request_dequeue_xprt(struct rpc_task *task); 355 bool xprt_request_need_retransmit(struct rpc_task *task); 356 void xprt_transmit(struct rpc_task *task); 357 void xprt_end_transmit(struct rpc_task *task); 358 int xprt_adjust_timeout(struct rpc_rqst *req); 359 void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task); 360 void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task); 361 void xprt_release(struct rpc_task *task); 362 struct rpc_xprt * xprt_get(struct rpc_xprt *xprt); 363 void xprt_put(struct rpc_xprt *xprt); 364 struct rpc_xprt * xprt_alloc(struct net *net, size_t size, 365 unsigned int num_prealloc, 366 unsigned int max_req); 367 void xprt_free(struct rpc_xprt *); 368 369 static inline int 370 xprt_enable_swap(struct rpc_xprt *xprt) 371 { 372 return xprt->ops->enable_swap(xprt); 373 } 374 375 static inline void 376 xprt_disable_swap(struct rpc_xprt *xprt) 377 { 378 xprt->ops->disable_swap(xprt); 379 } 380 381 /* 382 * Transport switch helper functions 383 */ 384 int xprt_register_transport(struct xprt_class *type); 385 int xprt_unregister_transport(struct xprt_class *type); 386 int xprt_load_transport(const char *); 387 void xprt_wait_for_reply_request_def(struct rpc_task *task); 388 void xprt_wait_for_reply_request_rtt(struct rpc_task *task); 389 void xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status); 390 void xprt_wait_for_buffer_space(struct rpc_xprt *xprt); 391 bool xprt_write_space(struct rpc_xprt *xprt); 392 void xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result); 393 struct rpc_rqst * xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid); 394 void xprt_update_rtt(struct rpc_task *task); 395 void xprt_complete_rqst(struct rpc_task *task, int copied); 396 void xprt_pin_rqst(struct rpc_rqst *req); 397 void xprt_unpin_rqst(struct rpc_rqst *req); 398 void xprt_release_rqst_cong(struct rpc_task *task); 399 bool xprt_request_get_cong(struct rpc_xprt *xprt, struct rpc_rqst *req); 400 void xprt_disconnect_done(struct rpc_xprt *xprt); 401 void xprt_force_disconnect(struct rpc_xprt *xprt); 402 void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie); 403 404 bool xprt_lock_connect(struct rpc_xprt *, struct rpc_task *, void *); 405 void xprt_unlock_connect(struct rpc_xprt *, void *); 406 407 /* 408 * Reserved bit positions in xprt->state 409 */ 410 #define XPRT_LOCKED (0) 411 #define XPRT_CONNECTED (1) 412 #define XPRT_CONNECTING (2) 413 #define XPRT_CLOSE_WAIT (3) 414 #define XPRT_BOUND (4) 415 #define XPRT_BINDING (5) 416 #define XPRT_CLOSING (6) 417 #define XPRT_CONGESTED (9) 418 #define XPRT_CWND_WAIT (10) 419 #define XPRT_WRITE_SPACE (11) 420 421 static inline void xprt_set_connected(struct rpc_xprt *xprt) 422 { 423 set_bit(XPRT_CONNECTED, &xprt->state); 424 } 425 426 static inline void xprt_clear_connected(struct rpc_xprt *xprt) 427 { 428 clear_bit(XPRT_CONNECTED, &xprt->state); 429 } 430 431 static inline int xprt_connected(struct rpc_xprt *xprt) 432 { 433 return test_bit(XPRT_CONNECTED, &xprt->state); 434 } 435 436 static inline int xprt_test_and_set_connected(struct rpc_xprt *xprt) 437 { 438 return test_and_set_bit(XPRT_CONNECTED, &xprt->state); 439 } 440 441 static inline int xprt_test_and_clear_connected(struct rpc_xprt *xprt) 442 { 443 return test_and_clear_bit(XPRT_CONNECTED, &xprt->state); 444 } 445 446 static inline void xprt_clear_connecting(struct rpc_xprt *xprt) 447 { 448 smp_mb__before_atomic(); 449 clear_bit(XPRT_CONNECTING, &xprt->state); 450 smp_mb__after_atomic(); 451 } 452 453 static inline int xprt_connecting(struct rpc_xprt *xprt) 454 { 455 return test_bit(XPRT_CONNECTING, &xprt->state); 456 } 457 458 static inline int xprt_test_and_set_connecting(struct rpc_xprt *xprt) 459 { 460 return test_and_set_bit(XPRT_CONNECTING, &xprt->state); 461 } 462 463 static inline void xprt_set_bound(struct rpc_xprt *xprt) 464 { 465 test_and_set_bit(XPRT_BOUND, &xprt->state); 466 } 467 468 static inline int xprt_bound(struct rpc_xprt *xprt) 469 { 470 return test_bit(XPRT_BOUND, &xprt->state); 471 } 472 473 static inline void xprt_clear_bound(struct rpc_xprt *xprt) 474 { 475 clear_bit(XPRT_BOUND, &xprt->state); 476 } 477 478 static inline void xprt_clear_binding(struct rpc_xprt *xprt) 479 { 480 smp_mb__before_atomic(); 481 clear_bit(XPRT_BINDING, &xprt->state); 482 smp_mb__after_atomic(); 483 } 484 485 static inline int xprt_test_and_set_binding(struct rpc_xprt *xprt) 486 { 487 return test_and_set_bit(XPRT_BINDING, &xprt->state); 488 } 489 490 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) 491 extern unsigned int rpc_inject_disconnect; 492 static inline void xprt_inject_disconnect(struct rpc_xprt *xprt) 493 { 494 if (!rpc_inject_disconnect) 495 return; 496 if (atomic_dec_return(&xprt->inject_disconnect)) 497 return; 498 atomic_set(&xprt->inject_disconnect, rpc_inject_disconnect); 499 xprt->ops->inject_disconnect(xprt); 500 } 501 #else 502 static inline void xprt_inject_disconnect(struct rpc_xprt *xprt) 503 { 504 } 505 #endif 506 507 #endif /* _LINUX_SUNRPC_XPRT_H */ 508