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 86 union { 87 struct list_head rq_list; /* Slot allocation list */ 88 struct rb_node rq_recv; /* Receive queue */ 89 }; 90 91 struct list_head rq_xmit; /* Send queue */ 92 struct list_head rq_xmit2; /* Send queue */ 93 94 void *rq_buffer; /* Call XDR encode buffer */ 95 size_t rq_callsize; 96 void *rq_rbuffer; /* Reply XDR decode buffer */ 97 size_t rq_rcvsize; 98 size_t rq_xmit_bytes_sent; /* total bytes sent */ 99 size_t rq_reply_bytes_recvd; /* total reply bytes */ 100 /* received */ 101 102 struct xdr_buf rq_private_buf; /* The receive buffer 103 * used in the softirq. 104 */ 105 unsigned long rq_majortimeo; /* major timeout alarm */ 106 unsigned long rq_timeout; /* Current timeout value */ 107 ktime_t rq_rtt; /* round-trip time */ 108 unsigned int rq_retries; /* # of retries */ 109 unsigned int rq_connect_cookie; 110 /* A cookie used to track the 111 state of the transport 112 connection */ 113 atomic_t rq_pin; 114 115 /* 116 * Partial send handling 117 */ 118 u32 rq_bytes_sent; /* Bytes we have sent */ 119 120 ktime_t rq_xtime; /* transmit time stamp */ 121 int rq_ntrans; 122 123 #if defined(CONFIG_SUNRPC_BACKCHANNEL) 124 struct list_head rq_bc_list; /* Callback service list */ 125 unsigned long rq_bc_pa_state; /* Backchannel prealloc state */ 126 struct list_head rq_bc_pa_list; /* Backchannel prealloc list */ 127 #endif /* CONFIG_SUNRPC_BACKCHANEL */ 128 }; 129 #define rq_svec rq_snd_buf.head 130 #define rq_slen rq_snd_buf.len 131 132 struct rpc_xprt_ops { 133 void (*set_buffer_size)(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize); 134 int (*reserve_xprt)(struct rpc_xprt *xprt, struct rpc_task *task); 135 void (*release_xprt)(struct rpc_xprt *xprt, struct rpc_task *task); 136 void (*alloc_slot)(struct rpc_xprt *xprt, struct rpc_task *task); 137 void (*free_slot)(struct rpc_xprt *xprt, 138 struct rpc_rqst *req); 139 void (*rpcbind)(struct rpc_task *task); 140 void (*set_port)(struct rpc_xprt *xprt, unsigned short port); 141 void (*connect)(struct rpc_xprt *xprt, struct rpc_task *task); 142 int (*buf_alloc)(struct rpc_task *task); 143 void (*buf_free)(struct rpc_task *task); 144 void (*prepare_request)(struct rpc_rqst *req); 145 int (*send_request)(struct rpc_rqst *req); 146 void (*wait_for_reply_request)(struct rpc_task *task); 147 void (*timer)(struct rpc_xprt *xprt, struct rpc_task *task); 148 void (*release_request)(struct rpc_task *task); 149 void (*close)(struct rpc_xprt *xprt); 150 void (*destroy)(struct rpc_xprt *xprt); 151 void (*set_connect_timeout)(struct rpc_xprt *xprt, 152 unsigned long connect_timeout, 153 unsigned long reconnect_timeout); 154 void (*print_stats)(struct rpc_xprt *xprt, struct seq_file *seq); 155 int (*enable_swap)(struct rpc_xprt *xprt); 156 void (*disable_swap)(struct rpc_xprt *xprt); 157 void (*inject_disconnect)(struct rpc_xprt *xprt); 158 int (*bc_setup)(struct rpc_xprt *xprt, 159 unsigned int min_reqs); 160 size_t (*bc_maxpayload)(struct rpc_xprt *xprt); 161 unsigned int (*bc_num_slots)(struct rpc_xprt *xprt); 162 void (*bc_free_rqst)(struct rpc_rqst *rqst); 163 void (*bc_destroy)(struct rpc_xprt *xprt, 164 unsigned int max_reqs); 165 }; 166 167 /* 168 * RPC transport identifiers 169 * 170 * To preserve compatibility with the historical use of raw IP protocol 171 * id's for transport selection, UDP and TCP identifiers are specified 172 * with the previous values. No such restriction exists for new transports, 173 * except that they may not collide with these values (17 and 6, 174 * respectively). 175 */ 176 #define XPRT_TRANSPORT_BC (1 << 31) 177 enum xprt_transports { 178 XPRT_TRANSPORT_UDP = IPPROTO_UDP, 179 XPRT_TRANSPORT_TCP = IPPROTO_TCP, 180 XPRT_TRANSPORT_BC_TCP = IPPROTO_TCP | XPRT_TRANSPORT_BC, 181 XPRT_TRANSPORT_RDMA = 256, 182 XPRT_TRANSPORT_BC_RDMA = XPRT_TRANSPORT_RDMA | XPRT_TRANSPORT_BC, 183 XPRT_TRANSPORT_LOCAL = 257, 184 }; 185 186 struct rpc_xprt { 187 struct kref kref; /* Reference count */ 188 const struct rpc_xprt_ops *ops; /* transport methods */ 189 190 const struct rpc_timeout *timeout; /* timeout parms */ 191 struct sockaddr_storage addr; /* server address */ 192 size_t addrlen; /* size of server address */ 193 int prot; /* IP protocol */ 194 195 unsigned long cong; /* current congestion */ 196 unsigned long cwnd; /* congestion window */ 197 198 size_t max_payload; /* largest RPC payload size, 199 in bytes */ 200 201 struct rpc_wait_queue binding; /* requests waiting on rpcbind */ 202 struct rpc_wait_queue sending; /* requests waiting to send */ 203 struct rpc_wait_queue pending; /* requests in flight */ 204 struct rpc_wait_queue backlog; /* waiting for slot */ 205 struct list_head free; /* free slots */ 206 unsigned int max_reqs; /* max number of slots */ 207 unsigned int min_reqs; /* min number of slots */ 208 unsigned int num_reqs; /* total slots */ 209 unsigned long state; /* transport state */ 210 unsigned char resvport : 1; /* use a reserved port */ 211 atomic_t swapper; /* we're swapping over this 212 transport */ 213 unsigned int bind_index; /* bind function index */ 214 215 /* 216 * Multipath 217 */ 218 struct list_head xprt_switch; 219 220 /* 221 * Connection of transports 222 */ 223 unsigned long bind_timeout, 224 reestablish_timeout; 225 unsigned int connect_cookie; /* A cookie that gets bumped 226 every time the transport 227 is reconnected */ 228 229 /* 230 * Disconnection of idle transports 231 */ 232 struct work_struct task_cleanup; 233 struct timer_list timer; 234 unsigned long last_used, 235 idle_timeout, 236 connect_timeout, 237 max_reconnect_timeout; 238 239 /* 240 * Send stuff 241 */ 242 atomic_long_t queuelen; 243 spinlock_t transport_lock; /* lock transport info */ 244 spinlock_t reserve_lock; /* lock slot table */ 245 spinlock_t queue_lock; /* send/receive queue lock */ 246 u32 xid; /* Next XID value to use */ 247 struct rpc_task * snd_task; /* Task blocked in send */ 248 249 struct list_head xmit_queue; /* Send queue */ 250 251 struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */ 252 #if defined(CONFIG_SUNRPC_BACKCHANNEL) 253 struct svc_serv *bc_serv; /* The RPC service which will */ 254 /* process the callback */ 255 unsigned int bc_alloc_max; 256 unsigned int bc_alloc_count; /* Total number of preallocs */ 257 atomic_t bc_slot_count; /* Number of allocated slots */ 258 spinlock_t bc_pa_lock; /* Protects the preallocated 259 * items */ 260 struct list_head bc_pa_list; /* List of preallocated 261 * backchannel rpc_rqst's */ 262 #endif /* CONFIG_SUNRPC_BACKCHANNEL */ 263 264 struct rb_root recv_queue; /* Receive queue */ 265 266 struct { 267 unsigned long bind_count, /* total number of binds */ 268 connect_count, /* total number of connects */ 269 connect_start, /* connect start timestamp */ 270 connect_time, /* jiffies waiting for connect */ 271 sends, /* how many complete requests */ 272 recvs, /* how many complete requests */ 273 bad_xids, /* lookup_rqst didn't find XID */ 274 max_slots; /* max rpc_slots used */ 275 276 unsigned long long req_u, /* average requests on the wire */ 277 bklog_u, /* backlog queue utilization */ 278 sending_u, /* send q utilization */ 279 pending_u; /* pend q utilization */ 280 } stat; 281 282 struct net *xprt_net; 283 const char *servername; 284 const char *address_strings[RPC_DISPLAY_MAX]; 285 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) 286 struct dentry *debugfs; /* debugfs directory */ 287 atomic_t inject_disconnect; 288 #endif 289 struct rcu_head rcu; 290 }; 291 292 #if defined(CONFIG_SUNRPC_BACKCHANNEL) 293 /* 294 * Backchannel flags 295 */ 296 #define RPC_BC_PA_IN_USE 0x0001 /* Preallocated backchannel */ 297 /* buffer in use */ 298 #endif /* CONFIG_SUNRPC_BACKCHANNEL */ 299 300 #if defined(CONFIG_SUNRPC_BACKCHANNEL) 301 static inline int bc_prealloc(struct rpc_rqst *req) 302 { 303 return test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state); 304 } 305 #else 306 static inline int bc_prealloc(struct rpc_rqst *req) 307 { 308 return 0; 309 } 310 #endif /* CONFIG_SUNRPC_BACKCHANNEL */ 311 312 #define XPRT_CREATE_INFINITE_SLOTS (1U) 313 #define XPRT_CREATE_NO_IDLE_TIMEOUT (1U << 1) 314 315 struct xprt_create { 316 int ident; /* XPRT_TRANSPORT identifier */ 317 struct net * net; 318 struct sockaddr * srcaddr; /* optional local address */ 319 struct sockaddr * dstaddr; /* remote peer address */ 320 size_t addrlen; 321 const char *servername; 322 struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */ 323 struct rpc_xprt_switch *bc_xps; 324 unsigned int flags; 325 }; 326 327 struct xprt_class { 328 struct list_head list; 329 int ident; /* XPRT_TRANSPORT identifier */ 330 struct rpc_xprt * (*setup)(struct xprt_create *); 331 struct module *owner; 332 char name[32]; 333 }; 334 335 /* 336 * Generic internal transport functions 337 */ 338 struct rpc_xprt *xprt_create_transport(struct xprt_create *args); 339 void xprt_connect(struct rpc_task *task); 340 unsigned long xprt_reconnect_delay(const struct rpc_xprt *xprt); 341 void xprt_reconnect_backoff(struct rpc_xprt *xprt, 342 unsigned long init_to); 343 void xprt_reserve(struct rpc_task *task); 344 void xprt_retry_reserve(struct rpc_task *task); 345 int xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task); 346 int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task); 347 void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task); 348 void xprt_free_slot(struct rpc_xprt *xprt, 349 struct rpc_rqst *req); 350 void xprt_request_prepare(struct rpc_rqst *req); 351 bool xprt_prepare_transmit(struct rpc_task *task); 352 void xprt_request_enqueue_transmit(struct rpc_task *task); 353 void xprt_request_enqueue_receive(struct rpc_task *task); 354 void xprt_request_wait_receive(struct rpc_task *task); 355 void xprt_request_dequeue_xprt(struct rpc_task *task); 356 bool xprt_request_need_retransmit(struct rpc_task *task); 357 void xprt_transmit(struct rpc_task *task); 358 void xprt_end_transmit(struct rpc_task *task); 359 int xprt_adjust_timeout(struct rpc_rqst *req); 360 void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task); 361 void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task); 362 void xprt_release(struct rpc_task *task); 363 struct rpc_xprt * xprt_get(struct rpc_xprt *xprt); 364 void xprt_put(struct rpc_xprt *xprt); 365 struct rpc_xprt * xprt_alloc(struct net *net, size_t size, 366 unsigned int num_prealloc, 367 unsigned int max_req); 368 void xprt_free(struct rpc_xprt *); 369 370 static inline int 371 xprt_enable_swap(struct rpc_xprt *xprt) 372 { 373 return xprt->ops->enable_swap(xprt); 374 } 375 376 static inline void 377 xprt_disable_swap(struct rpc_xprt *xprt) 378 { 379 xprt->ops->disable_swap(xprt); 380 } 381 382 /* 383 * Transport switch helper functions 384 */ 385 int xprt_register_transport(struct xprt_class *type); 386 int xprt_unregister_transport(struct xprt_class *type); 387 int xprt_load_transport(const char *); 388 void xprt_wait_for_reply_request_def(struct rpc_task *task); 389 void xprt_wait_for_reply_request_rtt(struct rpc_task *task); 390 void xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status); 391 void xprt_wait_for_buffer_space(struct rpc_xprt *xprt); 392 bool xprt_write_space(struct rpc_xprt *xprt); 393 void xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result); 394 struct rpc_rqst * xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid); 395 void xprt_update_rtt(struct rpc_task *task); 396 void xprt_complete_rqst(struct rpc_task *task, int copied); 397 void xprt_pin_rqst(struct rpc_rqst *req); 398 void xprt_unpin_rqst(struct rpc_rqst *req); 399 void xprt_release_rqst_cong(struct rpc_task *task); 400 bool xprt_request_get_cong(struct rpc_xprt *xprt, struct rpc_rqst *req); 401 void xprt_disconnect_done(struct rpc_xprt *xprt); 402 void xprt_force_disconnect(struct rpc_xprt *xprt); 403 void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie); 404 405 bool xprt_lock_connect(struct rpc_xprt *, struct rpc_task *, void *); 406 void xprt_unlock_connect(struct rpc_xprt *, void *); 407 408 /* 409 * Reserved bit positions in xprt->state 410 */ 411 #define XPRT_LOCKED (0) 412 #define XPRT_CONNECTED (1) 413 #define XPRT_CONNECTING (2) 414 #define XPRT_CLOSE_WAIT (3) 415 #define XPRT_BOUND (4) 416 #define XPRT_BINDING (5) 417 #define XPRT_CLOSING (6) 418 #define XPRT_CONGESTED (9) 419 #define XPRT_CWND_WAIT (10) 420 #define XPRT_WRITE_SPACE (11) 421 422 static inline void xprt_set_connected(struct rpc_xprt *xprt) 423 { 424 set_bit(XPRT_CONNECTED, &xprt->state); 425 } 426 427 static inline void xprt_clear_connected(struct rpc_xprt *xprt) 428 { 429 clear_bit(XPRT_CONNECTED, &xprt->state); 430 } 431 432 static inline int xprt_connected(struct rpc_xprt *xprt) 433 { 434 return test_bit(XPRT_CONNECTED, &xprt->state); 435 } 436 437 static inline int xprt_test_and_set_connected(struct rpc_xprt *xprt) 438 { 439 return test_and_set_bit(XPRT_CONNECTED, &xprt->state); 440 } 441 442 static inline int xprt_test_and_clear_connected(struct rpc_xprt *xprt) 443 { 444 return test_and_clear_bit(XPRT_CONNECTED, &xprt->state); 445 } 446 447 static inline void xprt_clear_connecting(struct rpc_xprt *xprt) 448 { 449 smp_mb__before_atomic(); 450 clear_bit(XPRT_CONNECTING, &xprt->state); 451 smp_mb__after_atomic(); 452 } 453 454 static inline int xprt_connecting(struct rpc_xprt *xprt) 455 { 456 return test_bit(XPRT_CONNECTING, &xprt->state); 457 } 458 459 static inline int xprt_test_and_set_connecting(struct rpc_xprt *xprt) 460 { 461 return test_and_set_bit(XPRT_CONNECTING, &xprt->state); 462 } 463 464 static inline void xprt_set_bound(struct rpc_xprt *xprt) 465 { 466 test_and_set_bit(XPRT_BOUND, &xprt->state); 467 } 468 469 static inline int xprt_bound(struct rpc_xprt *xprt) 470 { 471 return test_bit(XPRT_BOUND, &xprt->state); 472 } 473 474 static inline void xprt_clear_bound(struct rpc_xprt *xprt) 475 { 476 clear_bit(XPRT_BOUND, &xprt->state); 477 } 478 479 static inline void xprt_clear_binding(struct rpc_xprt *xprt) 480 { 481 smp_mb__before_atomic(); 482 clear_bit(XPRT_BINDING, &xprt->state); 483 smp_mb__after_atomic(); 484 } 485 486 static inline int xprt_test_and_set_binding(struct rpc_xprt *xprt) 487 { 488 return test_and_set_bit(XPRT_BINDING, &xprt->state); 489 } 490 491 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) 492 extern unsigned int rpc_inject_disconnect; 493 static inline void xprt_inject_disconnect(struct rpc_xprt *xprt) 494 { 495 if (!rpc_inject_disconnect) 496 return; 497 if (atomic_dec_return(&xprt->inject_disconnect)) 498 return; 499 atomic_set(&xprt->inject_disconnect, rpc_inject_disconnect); 500 xprt->ops->inject_disconnect(xprt); 501 } 502 #else 503 static inline void xprt_inject_disconnect(struct rpc_xprt *xprt) 504 { 505 } 506 #endif 507 508 #endif /* __KERNEL__*/ 509 510 #endif /* _LINUX_SUNRPC_XPRT_H */ 511