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