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_minortimeo; /* minor timeout alarm */ 105 unsigned long rq_timeout; /* Current timeout value */ 106 ktime_t rq_rtt; /* round-trip time */ 107 unsigned int rq_retries; /* # of retries */ 108 unsigned int rq_connect_cookie; 109 /* A cookie used to track the 110 state of the transport 111 connection */ 112 atomic_t rq_pin; 113 114 /* 115 * Partial send handling 116 */ 117 u32 rq_bytes_sent; /* Bytes we have sent */ 118 119 ktime_t rq_xtime; /* transmit time stamp */ 120 int rq_ntrans; 121 122 #if defined(CONFIG_SUNRPC_BACKCHANNEL) 123 struct list_head rq_bc_list; /* Callback service list */ 124 unsigned long rq_bc_pa_state; /* Backchannel prealloc state */ 125 struct list_head rq_bc_pa_list; /* Backchannel prealloc list */ 126 #endif /* CONFIG_SUNRPC_BACKCHANEL */ 127 }; 128 #define rq_svec rq_snd_buf.head 129 #define rq_slen rq_snd_buf.len 130 131 struct rpc_xprt_ops { 132 void (*set_buffer_size)(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize); 133 int (*reserve_xprt)(struct rpc_xprt *xprt, struct rpc_task *task); 134 void (*release_xprt)(struct rpc_xprt *xprt, struct rpc_task *task); 135 void (*alloc_slot)(struct rpc_xprt *xprt, struct rpc_task *task); 136 void (*free_slot)(struct rpc_xprt *xprt, 137 struct rpc_rqst *req); 138 void (*rpcbind)(struct rpc_task *task); 139 void (*set_port)(struct rpc_xprt *xprt, unsigned short port); 140 void (*connect)(struct rpc_xprt *xprt, struct rpc_task *task); 141 int (*buf_alloc)(struct rpc_task *task); 142 void (*buf_free)(struct rpc_task *task); 143 void (*prepare_request)(struct rpc_rqst *req); 144 int (*send_request)(struct rpc_rqst *req); 145 void (*wait_for_reply_request)(struct rpc_task *task); 146 void (*timer)(struct rpc_xprt *xprt, struct rpc_task *task); 147 void (*release_request)(struct rpc_task *task); 148 void (*close)(struct rpc_xprt *xprt); 149 void (*destroy)(struct rpc_xprt *xprt); 150 void (*set_connect_timeout)(struct rpc_xprt *xprt, 151 unsigned long connect_timeout, 152 unsigned long reconnect_timeout); 153 void (*print_stats)(struct rpc_xprt *xprt, struct seq_file *seq); 154 int (*enable_swap)(struct rpc_xprt *xprt); 155 void (*disable_swap)(struct rpc_xprt *xprt); 156 void (*inject_disconnect)(struct rpc_xprt *xprt); 157 int (*bc_setup)(struct rpc_xprt *xprt, 158 unsigned int min_reqs); 159 size_t (*bc_maxpayload)(struct rpc_xprt *xprt); 160 unsigned int (*bc_num_slots)(struct rpc_xprt *xprt); 161 void (*bc_free_rqst)(struct rpc_rqst *rqst); 162 void (*bc_destroy)(struct rpc_xprt *xprt, 163 unsigned int max_reqs); 164 }; 165 166 /* 167 * RPC transport identifiers 168 * 169 * To preserve compatibility with the historical use of raw IP protocol 170 * id's for transport selection, UDP and TCP identifiers are specified 171 * with the previous values. No such restriction exists for new transports, 172 * except that they may not collide with these values (17 and 6, 173 * respectively). 174 */ 175 #define XPRT_TRANSPORT_BC (1 << 31) 176 enum xprt_transports { 177 XPRT_TRANSPORT_UDP = IPPROTO_UDP, 178 XPRT_TRANSPORT_TCP = IPPROTO_TCP, 179 XPRT_TRANSPORT_BC_TCP = IPPROTO_TCP | XPRT_TRANSPORT_BC, 180 XPRT_TRANSPORT_RDMA = 256, 181 XPRT_TRANSPORT_BC_RDMA = XPRT_TRANSPORT_RDMA | XPRT_TRANSPORT_BC, 182 XPRT_TRANSPORT_LOCAL = 257, 183 }; 184 185 struct rpc_xprt { 186 struct kref kref; /* Reference count */ 187 const struct rpc_xprt_ops *ops; /* transport methods */ 188 189 const struct rpc_timeout *timeout; /* timeout parms */ 190 struct sockaddr_storage addr; /* server address */ 191 size_t addrlen; /* size of server address */ 192 int prot; /* IP protocol */ 193 194 unsigned long cong; /* current congestion */ 195 unsigned long cwnd; /* congestion window */ 196 197 size_t max_payload; /* largest RPC payload size, 198 in bytes */ 199 200 struct rpc_wait_queue binding; /* requests waiting on rpcbind */ 201 struct rpc_wait_queue sending; /* requests waiting to send */ 202 struct rpc_wait_queue pending; /* requests in flight */ 203 struct rpc_wait_queue backlog; /* waiting for slot */ 204 struct list_head free; /* free slots */ 205 unsigned int max_reqs; /* max number of slots */ 206 unsigned int min_reqs; /* min number of slots */ 207 unsigned int num_reqs; /* total slots */ 208 unsigned long state; /* transport state */ 209 unsigned char resvport : 1, /* use a reserved port */ 210 reuseport : 1; /* reuse port on reconnect */ 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 const char * netid[]; 334 }; 335 336 /* 337 * Generic internal transport functions 338 */ 339 struct rpc_xprt *xprt_create_transport(struct xprt_create *args); 340 void xprt_connect(struct rpc_task *task); 341 unsigned long xprt_reconnect_delay(const struct rpc_xprt *xprt); 342 void xprt_reconnect_backoff(struct rpc_xprt *xprt, 343 unsigned long init_to); 344 void xprt_reserve(struct rpc_task *task); 345 void xprt_retry_reserve(struct rpc_task *task); 346 int xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task); 347 int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task); 348 void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task); 349 void xprt_free_slot(struct rpc_xprt *xprt, 350 struct rpc_rqst *req); 351 void xprt_request_prepare(struct rpc_rqst *req); 352 bool xprt_prepare_transmit(struct rpc_task *task); 353 void xprt_request_enqueue_transmit(struct rpc_task *task); 354 void xprt_request_enqueue_receive(struct rpc_task *task); 355 void xprt_request_wait_receive(struct rpc_task *task); 356 void xprt_request_dequeue_xprt(struct rpc_task *task); 357 bool xprt_request_need_retransmit(struct rpc_task *task); 358 void xprt_transmit(struct rpc_task *task); 359 void xprt_end_transmit(struct rpc_task *task); 360 int xprt_adjust_timeout(struct rpc_rqst *req); 361 void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task); 362 void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task); 363 void xprt_release(struct rpc_task *task); 364 struct rpc_xprt * xprt_get(struct rpc_xprt *xprt); 365 void xprt_put(struct rpc_xprt *xprt); 366 struct rpc_xprt * xprt_alloc(struct net *net, size_t size, 367 unsigned int num_prealloc, 368 unsigned int max_req); 369 void xprt_free(struct rpc_xprt *); 370 371 static inline int 372 xprt_enable_swap(struct rpc_xprt *xprt) 373 { 374 return xprt->ops->enable_swap(xprt); 375 } 376 377 static inline void 378 xprt_disable_swap(struct rpc_xprt *xprt) 379 { 380 xprt->ops->disable_swap(xprt); 381 } 382 383 /* 384 * Transport switch helper functions 385 */ 386 int xprt_register_transport(struct xprt_class *type); 387 int xprt_unregister_transport(struct xprt_class *type); 388 int xprt_find_transport_ident(const char *); 389 void xprt_wait_for_reply_request_def(struct rpc_task *task); 390 void xprt_wait_for_reply_request_rtt(struct rpc_task *task); 391 void xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status); 392 void xprt_wait_for_buffer_space(struct rpc_xprt *xprt); 393 bool xprt_write_space(struct rpc_xprt *xprt); 394 void xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result); 395 struct rpc_rqst * xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid); 396 void xprt_update_rtt(struct rpc_task *task); 397 void xprt_complete_rqst(struct rpc_task *task, int copied); 398 void xprt_pin_rqst(struct rpc_rqst *req); 399 void xprt_unpin_rqst(struct rpc_rqst *req); 400 void xprt_release_rqst_cong(struct rpc_task *task); 401 bool xprt_request_get_cong(struct rpc_xprt *xprt, struct rpc_rqst *req); 402 void xprt_disconnect_done(struct rpc_xprt *xprt); 403 void xprt_force_disconnect(struct rpc_xprt *xprt); 404 void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie); 405 406 bool xprt_lock_connect(struct rpc_xprt *, struct rpc_task *, void *); 407 void xprt_unlock_connect(struct rpc_xprt *, void *); 408 409 /* 410 * Reserved bit positions in xprt->state 411 */ 412 #define XPRT_LOCKED (0) 413 #define XPRT_CONNECTED (1) 414 #define XPRT_CONNECTING (2) 415 #define XPRT_CLOSE_WAIT (3) 416 #define XPRT_BOUND (4) 417 #define XPRT_BINDING (5) 418 #define XPRT_CLOSING (6) 419 #define XPRT_CONGESTED (9) 420 #define XPRT_CWND_WAIT (10) 421 #define XPRT_WRITE_SPACE (11) 422 423 static inline void xprt_set_connected(struct rpc_xprt *xprt) 424 { 425 set_bit(XPRT_CONNECTED, &xprt->state); 426 } 427 428 static inline void xprt_clear_connected(struct rpc_xprt *xprt) 429 { 430 clear_bit(XPRT_CONNECTED, &xprt->state); 431 } 432 433 static inline int xprt_connected(struct rpc_xprt *xprt) 434 { 435 return test_bit(XPRT_CONNECTED, &xprt->state); 436 } 437 438 static inline int xprt_test_and_set_connected(struct rpc_xprt *xprt) 439 { 440 return test_and_set_bit(XPRT_CONNECTED, &xprt->state); 441 } 442 443 static inline int xprt_test_and_clear_connected(struct rpc_xprt *xprt) 444 { 445 return test_and_clear_bit(XPRT_CONNECTED, &xprt->state); 446 } 447 448 static inline void xprt_clear_connecting(struct rpc_xprt *xprt) 449 { 450 smp_mb__before_atomic(); 451 clear_bit(XPRT_CONNECTING, &xprt->state); 452 smp_mb__after_atomic(); 453 } 454 455 static inline int xprt_connecting(struct rpc_xprt *xprt) 456 { 457 return test_bit(XPRT_CONNECTING, &xprt->state); 458 } 459 460 static inline int xprt_test_and_set_connecting(struct rpc_xprt *xprt) 461 { 462 return test_and_set_bit(XPRT_CONNECTING, &xprt->state); 463 } 464 465 static inline void xprt_set_bound(struct rpc_xprt *xprt) 466 { 467 test_and_set_bit(XPRT_BOUND, &xprt->state); 468 } 469 470 static inline int xprt_bound(struct rpc_xprt *xprt) 471 { 472 return test_bit(XPRT_BOUND, &xprt->state); 473 } 474 475 static inline void xprt_clear_bound(struct rpc_xprt *xprt) 476 { 477 clear_bit(XPRT_BOUND, &xprt->state); 478 } 479 480 static inline void xprt_clear_binding(struct rpc_xprt *xprt) 481 { 482 smp_mb__before_atomic(); 483 clear_bit(XPRT_BINDING, &xprt->state); 484 smp_mb__after_atomic(); 485 } 486 487 static inline int xprt_test_and_set_binding(struct rpc_xprt *xprt) 488 { 489 return test_and_set_bit(XPRT_BINDING, &xprt->state); 490 } 491 492 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) 493 extern unsigned int rpc_inject_disconnect; 494 static inline void xprt_inject_disconnect(struct rpc_xprt *xprt) 495 { 496 if (!rpc_inject_disconnect) 497 return; 498 if (atomic_dec_return(&xprt->inject_disconnect)) 499 return; 500 atomic_set(&xprt->inject_disconnect, rpc_inject_disconnect); 501 xprt->ops->inject_disconnect(xprt); 502 } 503 #else 504 static inline void xprt_inject_disconnect(struct rpc_xprt *xprt) 505 { 506 } 507 #endif 508 509 #endif /* _LINUX_SUNRPC_XPRT_H */ 510