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 #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 atomic_long_t xmit_queuelen;
251
252 struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */
253 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
254 struct svc_serv *bc_serv; /* The RPC service which will */
255 /* process the callback */
256 unsigned int bc_alloc_max;
257 unsigned int bc_alloc_count; /* Total number of preallocs */
258 atomic_t bc_slot_count; /* Number of allocated slots */
259 spinlock_t bc_pa_lock; /* Protects the preallocated
260 * items */
261 struct list_head bc_pa_list; /* List of preallocated
262 * backchannel rpc_rqst's */
263 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
264
265 struct rb_root recv_queue; /* Receive queue */
266
267 struct {
268 unsigned long bind_count, /* total number of binds */
269 connect_count, /* total number of connects */
270 connect_start, /* connect start timestamp */
271 connect_time, /* jiffies waiting for connect */
272 sends, /* how many complete requests */
273 recvs, /* how many complete requests */
274 bad_xids, /* lookup_rqst didn't find XID */
275 max_slots; /* max rpc_slots used */
276
277 unsigned long long req_u, /* average requests on the wire */
278 bklog_u, /* backlog queue utilization */
279 sending_u, /* send q utilization */
280 pending_u; /* pend q utilization */
281 } stat;
282
283 struct net *xprt_net;
284 const char *servername;
285 const char *address_strings[RPC_DISPLAY_MAX];
286 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
287 struct dentry *debugfs; /* debugfs directory */
288 atomic_t inject_disconnect;
289 #endif
290 struct rcu_head rcu;
291 };
292
293 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
294 /*
295 * Backchannel flags
296 */
297 #define RPC_BC_PA_IN_USE 0x0001 /* Preallocated backchannel */
298 /* buffer in use */
299 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
300
301 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
bc_prealloc(struct rpc_rqst * req)302 static inline int bc_prealloc(struct rpc_rqst *req)
303 {
304 return test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
305 }
306 #else
bc_prealloc(struct rpc_rqst * req)307 static inline int bc_prealloc(struct rpc_rqst *req)
308 {
309 return 0;
310 }
311 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
312
313 #define XPRT_CREATE_INFINITE_SLOTS (1U)
314 #define XPRT_CREATE_NO_IDLE_TIMEOUT (1U << 1)
315
316 struct xprt_create {
317 int ident; /* XPRT_TRANSPORT identifier */
318 struct net * net;
319 struct sockaddr * srcaddr; /* optional local address */
320 struct sockaddr * dstaddr; /* remote peer address */
321 size_t addrlen;
322 const char *servername;
323 struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */
324 struct rpc_xprt_switch *bc_xps;
325 unsigned int flags;
326 };
327
328 struct xprt_class {
329 struct list_head list;
330 int ident; /* XPRT_TRANSPORT identifier */
331 struct rpc_xprt * (*setup)(struct xprt_create *);
332 struct module *owner;
333 char name[32];
334 const char * netid[];
335 };
336
337 /*
338 * Generic internal transport functions
339 */
340 struct rpc_xprt *xprt_create_transport(struct xprt_create *args);
341 void xprt_connect(struct rpc_task *task);
342 unsigned long xprt_reconnect_delay(const struct rpc_xprt *xprt);
343 void xprt_reconnect_backoff(struct rpc_xprt *xprt,
344 unsigned long init_to);
345 void xprt_reserve(struct rpc_task *task);
346 void xprt_retry_reserve(struct rpc_task *task);
347 int xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
348 int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
349 void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
350 void xprt_free_slot(struct rpc_xprt *xprt,
351 struct rpc_rqst *req);
352 void xprt_request_prepare(struct rpc_rqst *req);
353 bool xprt_prepare_transmit(struct rpc_task *task);
354 void xprt_request_enqueue_transmit(struct rpc_task *task);
355 void xprt_request_enqueue_receive(struct rpc_task *task);
356 void xprt_request_wait_receive(struct rpc_task *task);
357 void xprt_request_dequeue_xprt(struct rpc_task *task);
358 bool xprt_request_need_retransmit(struct rpc_task *task);
359 void xprt_transmit(struct rpc_task *task);
360 void xprt_end_transmit(struct rpc_task *task);
361 int xprt_adjust_timeout(struct rpc_rqst *req);
362 void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
363 void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
364 void xprt_release(struct rpc_task *task);
365 struct rpc_xprt * xprt_get(struct rpc_xprt *xprt);
366 void xprt_put(struct rpc_xprt *xprt);
367 struct rpc_xprt * xprt_alloc(struct net *net, size_t size,
368 unsigned int num_prealloc,
369 unsigned int max_req);
370 void xprt_free(struct rpc_xprt *);
371
372 static inline int
xprt_enable_swap(struct rpc_xprt * xprt)373 xprt_enable_swap(struct rpc_xprt *xprt)
374 {
375 return xprt->ops->enable_swap(xprt);
376 }
377
378 static inline void
xprt_disable_swap(struct rpc_xprt * xprt)379 xprt_disable_swap(struct rpc_xprt *xprt)
380 {
381 xprt->ops->disable_swap(xprt);
382 }
383
384 /*
385 * Transport switch helper functions
386 */
387 int xprt_register_transport(struct xprt_class *type);
388 int xprt_unregister_transport(struct xprt_class *type);
389 int xprt_find_transport_ident(const char *);
390 void xprt_wait_for_reply_request_def(struct rpc_task *task);
391 void xprt_wait_for_reply_request_rtt(struct rpc_task *task);
392 void xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status);
393 void xprt_wait_for_buffer_space(struct rpc_xprt *xprt);
394 bool xprt_write_space(struct rpc_xprt *xprt);
395 void xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result);
396 struct rpc_rqst * xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid);
397 void xprt_update_rtt(struct rpc_task *task);
398 void xprt_complete_rqst(struct rpc_task *task, int copied);
399 void xprt_pin_rqst(struct rpc_rqst *req);
400 void xprt_unpin_rqst(struct rpc_rqst *req);
401 void xprt_release_rqst_cong(struct rpc_task *task);
402 bool xprt_request_get_cong(struct rpc_xprt *xprt, struct rpc_rqst *req);
403 void xprt_disconnect_done(struct rpc_xprt *xprt);
404 void xprt_force_disconnect(struct rpc_xprt *xprt);
405 void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie);
406
407 bool xprt_lock_connect(struct rpc_xprt *, struct rpc_task *, void *);
408 void xprt_unlock_connect(struct rpc_xprt *, void *);
409
410 /*
411 * Reserved bit positions in xprt->state
412 */
413 #define XPRT_LOCKED (0)
414 #define XPRT_CONNECTED (1)
415 #define XPRT_CONNECTING (2)
416 #define XPRT_CLOSE_WAIT (3)
417 #define XPRT_BOUND (4)
418 #define XPRT_BINDING (5)
419 #define XPRT_CLOSING (6)
420 #define XPRT_CONGESTED (9)
421 #define XPRT_CWND_WAIT (10)
422 #define XPRT_WRITE_SPACE (11)
423
xprt_set_connected(struct rpc_xprt * xprt)424 static inline void xprt_set_connected(struct rpc_xprt *xprt)
425 {
426 set_bit(XPRT_CONNECTED, &xprt->state);
427 }
428
xprt_clear_connected(struct rpc_xprt * xprt)429 static inline void xprt_clear_connected(struct rpc_xprt *xprt)
430 {
431 clear_bit(XPRT_CONNECTED, &xprt->state);
432 }
433
xprt_connected(struct rpc_xprt * xprt)434 static inline int xprt_connected(struct rpc_xprt *xprt)
435 {
436 return test_bit(XPRT_CONNECTED, &xprt->state);
437 }
438
xprt_test_and_set_connected(struct rpc_xprt * xprt)439 static inline int xprt_test_and_set_connected(struct rpc_xprt *xprt)
440 {
441 return test_and_set_bit(XPRT_CONNECTED, &xprt->state);
442 }
443
xprt_test_and_clear_connected(struct rpc_xprt * xprt)444 static inline int xprt_test_and_clear_connected(struct rpc_xprt *xprt)
445 {
446 return test_and_clear_bit(XPRT_CONNECTED, &xprt->state);
447 }
448
xprt_clear_connecting(struct rpc_xprt * xprt)449 static inline void xprt_clear_connecting(struct rpc_xprt *xprt)
450 {
451 smp_mb__before_atomic();
452 clear_bit(XPRT_CONNECTING, &xprt->state);
453 smp_mb__after_atomic();
454 }
455
xprt_connecting(struct rpc_xprt * xprt)456 static inline int xprt_connecting(struct rpc_xprt *xprt)
457 {
458 return test_bit(XPRT_CONNECTING, &xprt->state);
459 }
460
xprt_test_and_set_connecting(struct rpc_xprt * xprt)461 static inline int xprt_test_and_set_connecting(struct rpc_xprt *xprt)
462 {
463 return test_and_set_bit(XPRT_CONNECTING, &xprt->state);
464 }
465
xprt_set_bound(struct rpc_xprt * xprt)466 static inline void xprt_set_bound(struct rpc_xprt *xprt)
467 {
468 test_and_set_bit(XPRT_BOUND, &xprt->state);
469 }
470
xprt_bound(struct rpc_xprt * xprt)471 static inline int xprt_bound(struct rpc_xprt *xprt)
472 {
473 return test_bit(XPRT_BOUND, &xprt->state);
474 }
475
xprt_clear_bound(struct rpc_xprt * xprt)476 static inline void xprt_clear_bound(struct rpc_xprt *xprt)
477 {
478 clear_bit(XPRT_BOUND, &xprt->state);
479 }
480
xprt_clear_binding(struct rpc_xprt * xprt)481 static inline void xprt_clear_binding(struct rpc_xprt *xprt)
482 {
483 smp_mb__before_atomic();
484 clear_bit(XPRT_BINDING, &xprt->state);
485 smp_mb__after_atomic();
486 }
487
xprt_test_and_set_binding(struct rpc_xprt * xprt)488 static inline int xprt_test_and_set_binding(struct rpc_xprt *xprt)
489 {
490 return test_and_set_bit(XPRT_BINDING, &xprt->state);
491 }
492
493 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
494 extern unsigned int rpc_inject_disconnect;
xprt_inject_disconnect(struct rpc_xprt * xprt)495 static inline void xprt_inject_disconnect(struct rpc_xprt *xprt)
496 {
497 if (!rpc_inject_disconnect)
498 return;
499 if (atomic_dec_return(&xprt->inject_disconnect))
500 return;
501 atomic_set(&xprt->inject_disconnect, rpc_inject_disconnect);
502 xprt->ops->inject_disconnect(xprt);
503 }
504 #else
xprt_inject_disconnect(struct rpc_xprt * xprt)505 static inline void xprt_inject_disconnect(struct rpc_xprt *xprt)
506 {
507 }
508 #endif
509
510 #endif /* _LINUX_SUNRPC_XPRT_H */
511