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