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)
bc_prealloc(struct rpc_rqst * req)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
bc_prealloc(struct rpc_rqst * req)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
xprt_enable_swap(struct rpc_xprt * xprt)371 xprt_enable_swap(struct rpc_xprt *xprt)
372 {
373 return xprt->ops->enable_swap(xprt);
374 }
375
376 static inline void
xprt_disable_swap(struct rpc_xprt * xprt)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
xprt_set_connected(struct rpc_xprt * xprt)422 static inline void xprt_set_connected(struct rpc_xprt *xprt)
423 {
424 set_bit(XPRT_CONNECTED, &xprt->state);
425 }
426
xprt_clear_connected(struct rpc_xprt * xprt)427 static inline void xprt_clear_connected(struct rpc_xprt *xprt)
428 {
429 clear_bit(XPRT_CONNECTED, &xprt->state);
430 }
431
xprt_connected(struct rpc_xprt * xprt)432 static inline int xprt_connected(struct rpc_xprt *xprt)
433 {
434 return test_bit(XPRT_CONNECTED, &xprt->state);
435 }
436
xprt_test_and_set_connected(struct rpc_xprt * xprt)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
xprt_test_and_clear_connected(struct rpc_xprt * xprt)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
xprt_clear_connecting(struct rpc_xprt * xprt)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
xprt_connecting(struct rpc_xprt * xprt)454 static inline int xprt_connecting(struct rpc_xprt *xprt)
455 {
456 return test_bit(XPRT_CONNECTING, &xprt->state);
457 }
458
xprt_test_and_set_connecting(struct rpc_xprt * xprt)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
xprt_set_bound(struct rpc_xprt * xprt)464 static inline void xprt_set_bound(struct rpc_xprt *xprt)
465 {
466 test_and_set_bit(XPRT_BOUND, &xprt->state);
467 }
468
xprt_bound(struct rpc_xprt * xprt)469 static inline int xprt_bound(struct rpc_xprt *xprt)
470 {
471 return test_bit(XPRT_BOUND, &xprt->state);
472 }
473
xprt_clear_bound(struct rpc_xprt * xprt)474 static inline void xprt_clear_bound(struct rpc_xprt *xprt)
475 {
476 clear_bit(XPRT_BOUND, &xprt->state);
477 }
478
xprt_clear_binding(struct rpc_xprt * xprt)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
xprt_test_and_set_binding(struct rpc_xprt * xprt)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;
xprt_inject_disconnect(struct rpc_xprt * xprt)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
xprt_inject_disconnect(struct rpc_xprt * xprt)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
