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/sunrpc/sched.h> 17 #include <linux/sunrpc/xdr.h> 18 #include <linux/sunrpc/msg_prot.h> 19 20 #ifdef __KERNEL__ 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 58 /* 59 * This describes a complete RPC request 60 */ 61 struct rpc_rqst { 62 /* 63 * This is the user-visible part 64 */ 65 struct rpc_xprt * rq_xprt; /* RPC client */ 66 struct xdr_buf rq_snd_buf; /* send buffer */ 67 struct xdr_buf rq_rcv_buf; /* recv buffer */ 68 69 /* 70 * This is the private part 71 */ 72 struct rpc_task * rq_task; /* RPC task data */ 73 struct rpc_cred * rq_cred; /* Bound cred */ 74 __be32 rq_xid; /* request XID */ 75 int rq_cong; /* has incremented xprt->cong */ 76 u32 rq_seqno; /* gss seq no. used on req. */ 77 int rq_enc_pages_num; 78 struct page **rq_enc_pages; /* scratch pages for use by 79 gss privacy code */ 80 void (*rq_release_snd_buf)(struct rpc_rqst *); /* release rq_enc_pages */ 81 struct list_head rq_list; 82 83 __u32 * rq_buffer; /* XDR encode buffer */ 84 size_t rq_callsize, 85 rq_rcvsize; 86 size_t rq_xmit_bytes_sent; /* total bytes sent */ 87 size_t rq_reply_bytes_recvd; /* total reply bytes */ 88 /* received */ 89 90 struct xdr_buf rq_private_buf; /* The receive buffer 91 * used in the softirq. 92 */ 93 unsigned long rq_majortimeo; /* major timeout alarm */ 94 unsigned long rq_timeout; /* Current timeout value */ 95 ktime_t rq_rtt; /* round-trip time */ 96 unsigned int rq_retries; /* # of retries */ 97 unsigned int rq_connect_cookie; 98 /* A cookie used to track the 99 state of the transport 100 connection */ 101 102 /* 103 * Partial send handling 104 */ 105 u32 rq_bytes_sent; /* Bytes we have sent */ 106 107 ktime_t rq_xtime; /* transmit time stamp */ 108 int rq_ntrans; 109 110 #if defined(CONFIG_SUNRPC_BACKCHANNEL) 111 struct list_head rq_bc_list; /* Callback service list */ 112 unsigned long rq_bc_pa_state; /* Backchannel prealloc state */ 113 struct list_head rq_bc_pa_list; /* Backchannel prealloc list */ 114 #endif /* CONFIG_SUNRPC_BACKCHANEL */ 115 }; 116 #define rq_svec rq_snd_buf.head 117 #define rq_slen rq_snd_buf.len 118 119 struct rpc_xprt_ops { 120 void (*set_buffer_size)(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize); 121 int (*reserve_xprt)(struct rpc_xprt *xprt, struct rpc_task *task); 122 void (*release_xprt)(struct rpc_xprt *xprt, struct rpc_task *task); 123 void (*alloc_slot)(struct rpc_xprt *xprt, struct rpc_task *task); 124 void (*rpcbind)(struct rpc_task *task); 125 void (*set_port)(struct rpc_xprt *xprt, unsigned short port); 126 void (*connect)(struct rpc_xprt *xprt, struct rpc_task *task); 127 void * (*buf_alloc)(struct rpc_task *task, size_t size); 128 void (*buf_free)(void *buffer); 129 int (*send_request)(struct rpc_task *task); 130 void (*set_retrans_timeout)(struct rpc_task *task); 131 void (*timer)(struct rpc_xprt *xprt, struct rpc_task *task); 132 void (*release_request)(struct rpc_task *task); 133 void (*close)(struct rpc_xprt *xprt); 134 void (*destroy)(struct rpc_xprt *xprt); 135 void (*print_stats)(struct rpc_xprt *xprt, struct seq_file *seq); 136 int (*enable_swap)(struct rpc_xprt *xprt); 137 void (*disable_swap)(struct rpc_xprt *xprt); 138 void (*inject_disconnect)(struct rpc_xprt *xprt); 139 }; 140 141 /* 142 * RPC transport identifiers 143 * 144 * To preserve compatibility with the historical use of raw IP protocol 145 * id's for transport selection, UDP and TCP identifiers are specified 146 * with the previous values. No such restriction exists for new transports, 147 * except that they may not collide with these values (17 and 6, 148 * respectively). 149 */ 150 #define XPRT_TRANSPORT_BC (1 << 31) 151 enum xprt_transports { 152 XPRT_TRANSPORT_UDP = IPPROTO_UDP, 153 XPRT_TRANSPORT_TCP = IPPROTO_TCP, 154 XPRT_TRANSPORT_BC_TCP = IPPROTO_TCP | XPRT_TRANSPORT_BC, 155 XPRT_TRANSPORT_RDMA = 256, 156 XPRT_TRANSPORT_LOCAL = 257, 157 }; 158 159 struct rpc_xprt { 160 atomic_t count; /* Reference count */ 161 struct rpc_xprt_ops * ops; /* transport methods */ 162 163 const struct rpc_timeout *timeout; /* timeout parms */ 164 struct sockaddr_storage addr; /* server address */ 165 size_t addrlen; /* size of server address */ 166 int prot; /* IP protocol */ 167 168 unsigned long cong; /* current congestion */ 169 unsigned long cwnd; /* congestion window */ 170 171 size_t max_payload; /* largest RPC payload size, 172 in bytes */ 173 unsigned int tsh_size; /* size of transport specific 174 header */ 175 176 struct rpc_wait_queue binding; /* requests waiting on rpcbind */ 177 struct rpc_wait_queue sending; /* requests waiting to send */ 178 struct rpc_wait_queue pending; /* requests in flight */ 179 struct rpc_wait_queue backlog; /* waiting for slot */ 180 struct list_head free; /* free slots */ 181 unsigned int max_reqs; /* max number of slots */ 182 unsigned int min_reqs; /* min number of slots */ 183 atomic_t num_reqs; /* total slots */ 184 unsigned long state; /* transport state */ 185 unsigned char resvport : 1; /* use a reserved port */ 186 atomic_t swapper; /* we're swapping over this 187 transport */ 188 unsigned int bind_index; /* bind function index */ 189 190 /* 191 * Connection of transports 192 */ 193 unsigned long bind_timeout, 194 reestablish_timeout; 195 unsigned int connect_cookie; /* A cookie that gets bumped 196 every time the transport 197 is reconnected */ 198 199 /* 200 * Disconnection of idle transports 201 */ 202 struct work_struct task_cleanup; 203 struct timer_list timer; 204 unsigned long last_used, 205 idle_timeout; 206 207 /* 208 * Send stuff 209 */ 210 spinlock_t transport_lock; /* lock transport info */ 211 spinlock_t reserve_lock; /* lock slot table */ 212 u32 xid; /* Next XID value to use */ 213 struct rpc_task * snd_task; /* Task blocked in send */ 214 struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */ 215 #if defined(CONFIG_SUNRPC_BACKCHANNEL) 216 struct svc_serv *bc_serv; /* The RPC service which will */ 217 /* process the callback */ 218 int bc_alloc_count; /* Total number of preallocs */ 219 atomic_t bc_free_slots; 220 spinlock_t bc_pa_lock; /* Protects the preallocated 221 * items */ 222 struct list_head bc_pa_list; /* List of preallocated 223 * backchannel rpc_rqst's */ 224 #endif /* CONFIG_SUNRPC_BACKCHANNEL */ 225 struct list_head recv; 226 227 struct { 228 unsigned long bind_count, /* total number of binds */ 229 connect_count, /* total number of connects */ 230 connect_start, /* connect start timestamp */ 231 connect_time, /* jiffies waiting for connect */ 232 sends, /* how many complete requests */ 233 recvs, /* how many complete requests */ 234 bad_xids, /* lookup_rqst didn't find XID */ 235 max_slots; /* max rpc_slots used */ 236 237 unsigned long long req_u, /* average requests on the wire */ 238 bklog_u, /* backlog queue utilization */ 239 sending_u, /* send q utilization */ 240 pending_u; /* pend q utilization */ 241 } stat; 242 243 struct net *xprt_net; 244 const char *servername; 245 const char *address_strings[RPC_DISPLAY_MAX]; 246 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) 247 struct dentry *debugfs; /* debugfs directory */ 248 atomic_t inject_disconnect; 249 #endif 250 }; 251 252 #if defined(CONFIG_SUNRPC_BACKCHANNEL) 253 /* 254 * Backchannel flags 255 */ 256 #define RPC_BC_PA_IN_USE 0x0001 /* Preallocated backchannel */ 257 /* buffer in use */ 258 #endif /* CONFIG_SUNRPC_BACKCHANNEL */ 259 260 #if defined(CONFIG_SUNRPC_BACKCHANNEL) 261 static inline int bc_prealloc(struct rpc_rqst *req) 262 { 263 return test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state); 264 } 265 #else 266 static inline int bc_prealloc(struct rpc_rqst *req) 267 { 268 return 0; 269 } 270 #endif /* CONFIG_SUNRPC_BACKCHANNEL */ 271 272 #define XPRT_CREATE_INFINITE_SLOTS (1U) 273 #define XPRT_CREATE_NO_IDLE_TIMEOUT (1U << 1) 274 275 struct xprt_create { 276 int ident; /* XPRT_TRANSPORT identifier */ 277 struct net * net; 278 struct sockaddr * srcaddr; /* optional local address */ 279 struct sockaddr * dstaddr; /* remote peer address */ 280 size_t addrlen; 281 const char *servername; 282 struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */ 283 unsigned int flags; 284 }; 285 286 struct xprt_class { 287 struct list_head list; 288 int ident; /* XPRT_TRANSPORT identifier */ 289 struct rpc_xprt * (*setup)(struct xprt_create *); 290 struct module *owner; 291 char name[32]; 292 }; 293 294 /* 295 * Generic internal transport functions 296 */ 297 struct rpc_xprt *xprt_create_transport(struct xprt_create *args); 298 void xprt_connect(struct rpc_task *task); 299 void xprt_reserve(struct rpc_task *task); 300 void xprt_retry_reserve(struct rpc_task *task); 301 int xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task); 302 int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task); 303 void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task); 304 void xprt_lock_and_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task); 305 bool xprt_prepare_transmit(struct rpc_task *task); 306 void xprt_transmit(struct rpc_task *task); 307 void xprt_end_transmit(struct rpc_task *task); 308 int xprt_adjust_timeout(struct rpc_rqst *req); 309 void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task); 310 void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task); 311 void xprt_release(struct rpc_task *task); 312 void xprt_put(struct rpc_xprt *xprt); 313 struct rpc_xprt * xprt_alloc(struct net *net, size_t size, 314 unsigned int num_prealloc, 315 unsigned int max_req); 316 void xprt_free(struct rpc_xprt *); 317 318 /** 319 * xprt_get - return a reference to an RPC transport. 320 * @xprt: pointer to the transport 321 * 322 */ 323 static inline struct rpc_xprt *xprt_get(struct rpc_xprt *xprt) 324 { 325 if (atomic_inc_not_zero(&xprt->count)) 326 return xprt; 327 return NULL; 328 } 329 330 static inline __be32 *xprt_skip_transport_header(struct rpc_xprt *xprt, __be32 *p) 331 { 332 return p + xprt->tsh_size; 333 } 334 335 static inline int 336 xprt_enable_swap(struct rpc_xprt *xprt) 337 { 338 return xprt->ops->enable_swap(xprt); 339 } 340 341 static inline void 342 xprt_disable_swap(struct rpc_xprt *xprt) 343 { 344 xprt->ops->disable_swap(xprt); 345 } 346 347 /* 348 * Transport switch helper functions 349 */ 350 int xprt_register_transport(struct xprt_class *type); 351 int xprt_unregister_transport(struct xprt_class *type); 352 int xprt_load_transport(const char *); 353 void xprt_set_retrans_timeout_def(struct rpc_task *task); 354 void xprt_set_retrans_timeout_rtt(struct rpc_task *task); 355 void xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status); 356 void xprt_wait_for_buffer_space(struct rpc_task *task, rpc_action action); 357 void xprt_write_space(struct rpc_xprt *xprt); 358 void xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result); 359 struct rpc_rqst * xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid); 360 void xprt_complete_rqst(struct rpc_task *task, int copied); 361 void xprt_release_rqst_cong(struct rpc_task *task); 362 void xprt_disconnect_done(struct rpc_xprt *xprt); 363 void xprt_force_disconnect(struct rpc_xprt *xprt); 364 void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie); 365 366 bool xprt_lock_connect(struct rpc_xprt *, struct rpc_task *, void *); 367 void xprt_unlock_connect(struct rpc_xprt *, void *); 368 369 /* 370 * Reserved bit positions in xprt->state 371 */ 372 #define XPRT_LOCKED (0) 373 #define XPRT_CONNECTED (1) 374 #define XPRT_CONNECTING (2) 375 #define XPRT_CLOSE_WAIT (3) 376 #define XPRT_BOUND (4) 377 #define XPRT_BINDING (5) 378 #define XPRT_CLOSING (6) 379 #define XPRT_CONGESTED (9) 380 381 static inline void xprt_set_connected(struct rpc_xprt *xprt) 382 { 383 set_bit(XPRT_CONNECTED, &xprt->state); 384 } 385 386 static inline void xprt_clear_connected(struct rpc_xprt *xprt) 387 { 388 clear_bit(XPRT_CONNECTED, &xprt->state); 389 } 390 391 static inline int xprt_connected(struct rpc_xprt *xprt) 392 { 393 return test_bit(XPRT_CONNECTED, &xprt->state); 394 } 395 396 static inline int xprt_test_and_set_connected(struct rpc_xprt *xprt) 397 { 398 return test_and_set_bit(XPRT_CONNECTED, &xprt->state); 399 } 400 401 static inline int xprt_test_and_clear_connected(struct rpc_xprt *xprt) 402 { 403 return test_and_clear_bit(XPRT_CONNECTED, &xprt->state); 404 } 405 406 static inline void xprt_clear_connecting(struct rpc_xprt *xprt) 407 { 408 smp_mb__before_atomic(); 409 clear_bit(XPRT_CONNECTING, &xprt->state); 410 smp_mb__after_atomic(); 411 } 412 413 static inline int xprt_connecting(struct rpc_xprt *xprt) 414 { 415 return test_bit(XPRT_CONNECTING, &xprt->state); 416 } 417 418 static inline int xprt_test_and_set_connecting(struct rpc_xprt *xprt) 419 { 420 return test_and_set_bit(XPRT_CONNECTING, &xprt->state); 421 } 422 423 static inline void xprt_set_bound(struct rpc_xprt *xprt) 424 { 425 test_and_set_bit(XPRT_BOUND, &xprt->state); 426 } 427 428 static inline int xprt_bound(struct rpc_xprt *xprt) 429 { 430 return test_bit(XPRT_BOUND, &xprt->state); 431 } 432 433 static inline void xprt_clear_bound(struct rpc_xprt *xprt) 434 { 435 clear_bit(XPRT_BOUND, &xprt->state); 436 } 437 438 static inline void xprt_clear_binding(struct rpc_xprt *xprt) 439 { 440 smp_mb__before_atomic(); 441 clear_bit(XPRT_BINDING, &xprt->state); 442 smp_mb__after_atomic(); 443 } 444 445 static inline int xprt_test_and_set_binding(struct rpc_xprt *xprt) 446 { 447 return test_and_set_bit(XPRT_BINDING, &xprt->state); 448 } 449 450 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) 451 extern unsigned int rpc_inject_disconnect; 452 static inline void xprt_inject_disconnect(struct rpc_xprt *xprt) 453 { 454 if (!rpc_inject_disconnect) 455 return; 456 if (atomic_dec_return(&xprt->inject_disconnect)) 457 return; 458 atomic_set(&xprt->inject_disconnect, rpc_inject_disconnect); 459 xprt->ops->inject_disconnect(xprt); 460 } 461 #else 462 static inline void xprt_inject_disconnect(struct rpc_xprt *xprt) 463 { 464 } 465 #endif 466 467 #endif /* __KERNEL__*/ 468 469 #endif /* _LINUX_SUNRPC_XPRT_H */ 470