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 xprt_class;
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
85 union {
86 struct list_head rq_list; /* Slot allocation list */
87 struct rb_node rq_recv; /* Receive queue */
88 };
89
90 struct list_head rq_xmit; /* Send queue */
91 struct list_head rq_xmit2; /* Send queue */
92
93 void *rq_buffer; /* Call XDR encode buffer */
94 size_t rq_callsize;
95 void *rq_rbuffer; /* Reply XDR decode buffer */
96 size_t rq_rcvsize;
97 size_t rq_xmit_bytes_sent; /* total bytes sent */
98 size_t rq_reply_bytes_recvd; /* total reply bytes */
99 /* received */
100
101 struct xdr_buf rq_private_buf; /* The receive buffer
102 * used in the softirq.
103 */
104 unsigned long rq_majortimeo; /* major timeout alarm */
105 unsigned long rq_minortimeo; /* minor 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_sysfs_xprt;
187 struct rpc_xprt {
188 struct kref kref; /* Reference count */
189 const struct rpc_xprt_ops *ops; /* transport methods */
190 unsigned int id; /* transport id */
191
192 const struct rpc_timeout *timeout; /* timeout parms */
193 struct sockaddr_storage addr; /* server address */
194 size_t addrlen; /* size of server address */
195 int prot; /* IP protocol */
196
197 unsigned long cong; /* current congestion */
198 unsigned long cwnd; /* congestion window */
199
200 size_t max_payload; /* largest RPC payload size,
201 in bytes */
202
203 struct rpc_wait_queue binding; /* requests waiting on rpcbind */
204 struct rpc_wait_queue sending; /* requests waiting to send */
205 struct rpc_wait_queue pending; /* requests in flight */
206 struct rpc_wait_queue backlog; /* waiting for slot */
207 struct list_head free; /* free slots */
208 unsigned int max_reqs; /* max number of slots */
209 unsigned int min_reqs; /* min number of slots */
210 unsigned int num_reqs; /* total slots */
211 unsigned long state; /* transport state */
212 unsigned char resvport : 1, /* use a reserved port */
213 reuseport : 1; /* reuse port on reconnect */
214 atomic_t swapper; /* we're swapping over this
215 transport */
216 unsigned int bind_index; /* bind function index */
217
218 /*
219 * Multipath
220 */
221 struct list_head xprt_switch;
222
223 /*
224 * Connection of transports
225 */
226 unsigned long bind_timeout,
227 reestablish_timeout;
228 unsigned int connect_cookie; /* A cookie that gets bumped
229 every time the transport
230 is reconnected */
231
232 /*
233 * Disconnection of idle transports
234 */
235 struct work_struct task_cleanup;
236 struct timer_list timer;
237 unsigned long last_used,
238 idle_timeout,
239 connect_timeout,
240 max_reconnect_timeout;
241
242 /*
243 * Send stuff
244 */
245 atomic_long_t queuelen;
246 spinlock_t transport_lock; /* lock transport info */
247 spinlock_t reserve_lock; /* lock slot table */
248 spinlock_t queue_lock; /* send/receive queue lock */
249 u32 xid; /* Next XID value to use */
250 struct rpc_task * snd_task; /* Task blocked in send */
251
252 struct list_head xmit_queue; /* Send queue */
253 atomic_long_t xmit_queuelen;
254
255 struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */
256 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
257 struct svc_serv *bc_serv; /* The RPC service which will */
258 /* process the callback */
259 unsigned int bc_alloc_max;
260 unsigned int bc_alloc_count; /* Total number of preallocs */
261 atomic_t bc_slot_count; /* Number of allocated slots */
262 spinlock_t bc_pa_lock; /* Protects the preallocated
263 * items */
264 struct list_head bc_pa_list; /* List of preallocated
265 * backchannel rpc_rqst's */
266 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
267
268 struct rb_root recv_queue; /* Receive queue */
269
270 struct {
271 unsigned long bind_count, /* total number of binds */
272 connect_count, /* total number of connects */
273 connect_start, /* connect start timestamp */
274 connect_time, /* jiffies waiting for connect */
275 sends, /* how many complete requests */
276 recvs, /* how many complete requests */
277 bad_xids, /* lookup_rqst didn't find XID */
278 max_slots; /* max rpc_slots used */
279
280 unsigned long long req_u, /* average requests on the wire */
281 bklog_u, /* backlog queue utilization */
282 sending_u, /* send q utilization */
283 pending_u; /* pend q utilization */
284 } stat;
285
286 struct net *xprt_net;
287 const char *servername;
288 const char *address_strings[RPC_DISPLAY_MAX];
289 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
290 struct dentry *debugfs; /* debugfs directory */
291 #endif
292 struct rcu_head rcu;
293 const struct xprt_class *xprt_class;
294 struct rpc_sysfs_xprt *xprt_sysfs;
295 bool main; /*mark if this is the 1st transport */
296 };
297
298 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
299 /*
300 * Backchannel flags
301 */
302 #define RPC_BC_PA_IN_USE 0x0001 /* Preallocated backchannel */
303 /* buffer in use */
304 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
305
306 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
bc_prealloc(struct rpc_rqst * req)307 static inline int bc_prealloc(struct rpc_rqst *req)
308 {
309 return test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
310 }
311 #else
bc_prealloc(struct rpc_rqst * req)312 static inline int bc_prealloc(struct rpc_rqst *req)
313 {
314 return 0;
315 }
316 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
317
318 #define XPRT_CREATE_INFINITE_SLOTS (1U)
319 #define XPRT_CREATE_NO_IDLE_TIMEOUT (1U << 1)
320
321 struct xprt_create {
322 int ident; /* XPRT_TRANSPORT identifier */
323 struct net * net;
324 struct sockaddr * srcaddr; /* optional local address */
325 struct sockaddr * dstaddr; /* remote peer address */
326 size_t addrlen;
327 const char *servername;
328 struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */
329 struct rpc_xprt_switch *bc_xps;
330 unsigned int flags;
331 };
332
333 struct xprt_class {
334 struct list_head list;
335 int ident; /* XPRT_TRANSPORT identifier */
336 struct rpc_xprt * (*setup)(struct xprt_create *);
337 struct module *owner;
338 char name[32];
339 const char * netid[];
340 };
341
342 /*
343 * Generic internal transport functions
344 */
345 struct rpc_xprt *xprt_create_transport(struct xprt_create *args);
346 void xprt_connect(struct rpc_task *task);
347 unsigned long xprt_reconnect_delay(const struct rpc_xprt *xprt);
348 void xprt_reconnect_backoff(struct rpc_xprt *xprt,
349 unsigned long init_to);
350 void xprt_reserve(struct rpc_task *task);
351 void xprt_retry_reserve(struct rpc_task *task);
352 int xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
353 int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
354 void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
355 void xprt_free_slot(struct rpc_xprt *xprt,
356 struct rpc_rqst *req);
357 void xprt_request_prepare(struct rpc_rqst *req);
358 bool xprt_prepare_transmit(struct rpc_task *task);
359 void xprt_request_enqueue_transmit(struct rpc_task *task);
360 void xprt_request_enqueue_receive(struct rpc_task *task);
361 void xprt_request_wait_receive(struct rpc_task *task);
362 void xprt_request_dequeue_xprt(struct rpc_task *task);
363 bool xprt_request_need_retransmit(struct rpc_task *task);
364 void xprt_transmit(struct rpc_task *task);
365 void xprt_end_transmit(struct rpc_task *task);
366 int xprt_adjust_timeout(struct rpc_rqst *req);
367 void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
368 void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
369 void xprt_release(struct rpc_task *task);
370 struct rpc_xprt * xprt_get(struct rpc_xprt *xprt);
371 void xprt_put(struct rpc_xprt *xprt);
372 struct rpc_xprt * xprt_alloc(struct net *net, size_t size,
373 unsigned int num_prealloc,
374 unsigned int max_req);
375 void xprt_free(struct rpc_xprt *);
376 void xprt_add_backlog(struct rpc_xprt *xprt, struct rpc_task *task);
377 bool xprt_wake_up_backlog(struct rpc_xprt *xprt, struct rpc_rqst *req);
378 void xprt_cleanup_ids(void);
379
380 static inline int
xprt_enable_swap(struct rpc_xprt * xprt)381 xprt_enable_swap(struct rpc_xprt *xprt)
382 {
383 return xprt->ops->enable_swap(xprt);
384 }
385
386 static inline void
xprt_disable_swap(struct rpc_xprt * xprt)387 xprt_disable_swap(struct rpc_xprt *xprt)
388 {
389 xprt->ops->disable_swap(xprt);
390 }
391
392 /*
393 * Transport switch helper functions
394 */
395 int xprt_register_transport(struct xprt_class *type);
396 int xprt_unregister_transport(struct xprt_class *type);
397 int xprt_find_transport_ident(const char *);
398 void xprt_wait_for_reply_request_def(struct rpc_task *task);
399 void xprt_wait_for_reply_request_rtt(struct rpc_task *task);
400 void xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status);
401 void xprt_wait_for_buffer_space(struct rpc_xprt *xprt);
402 bool xprt_write_space(struct rpc_xprt *xprt);
403 void xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result);
404 struct rpc_rqst * xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid);
405 void xprt_update_rtt(struct rpc_task *task);
406 void xprt_complete_rqst(struct rpc_task *task, int copied);
407 void xprt_pin_rqst(struct rpc_rqst *req);
408 void xprt_unpin_rqst(struct rpc_rqst *req);
409 void xprt_release_rqst_cong(struct rpc_task *task);
410 bool xprt_request_get_cong(struct rpc_xprt *xprt, struct rpc_rqst *req);
411 void xprt_disconnect_done(struct rpc_xprt *xprt);
412 void xprt_force_disconnect(struct rpc_xprt *xprt);
413 void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie);
414
415 bool xprt_lock_connect(struct rpc_xprt *, struct rpc_task *, void *);
416 void xprt_unlock_connect(struct rpc_xprt *, void *);
417 void xprt_release_write(struct rpc_xprt *, struct rpc_task *);
418
419 /*
420 * Reserved bit positions in xprt->state
421 */
422 #define XPRT_LOCKED (0)
423 #define XPRT_CONNECTED (1)
424 #define XPRT_CONNECTING (2)
425 #define XPRT_CLOSE_WAIT (3)
426 #define XPRT_BOUND (4)
427 #define XPRT_BINDING (5)
428 #define XPRT_CLOSING (6)
429 #define XPRT_OFFLINE (7)
430 #define XPRT_REMOVE (8)
431 #define XPRT_CONGESTED (9)
432 #define XPRT_CWND_WAIT (10)
433 #define XPRT_WRITE_SPACE (11)
434 #define XPRT_SND_IS_COOKIE (12)
435
xprt_set_connected(struct rpc_xprt * xprt)436 static inline void xprt_set_connected(struct rpc_xprt *xprt)
437 {
438 set_bit(XPRT_CONNECTED, &xprt->state);
439 }
440
xprt_clear_connected(struct rpc_xprt * xprt)441 static inline void xprt_clear_connected(struct rpc_xprt *xprt)
442 {
443 clear_bit(XPRT_CONNECTED, &xprt->state);
444 }
445
xprt_connected(struct rpc_xprt * xprt)446 static inline int xprt_connected(struct rpc_xprt *xprt)
447 {
448 return test_bit(XPRT_CONNECTED, &xprt->state);
449 }
450
xprt_test_and_set_connected(struct rpc_xprt * xprt)451 static inline int xprt_test_and_set_connected(struct rpc_xprt *xprt)
452 {
453 return test_and_set_bit(XPRT_CONNECTED, &xprt->state);
454 }
455
xprt_test_and_clear_connected(struct rpc_xprt * xprt)456 static inline int xprt_test_and_clear_connected(struct rpc_xprt *xprt)
457 {
458 return test_and_clear_bit(XPRT_CONNECTED, &xprt->state);
459 }
460
xprt_clear_connecting(struct rpc_xprt * xprt)461 static inline void xprt_clear_connecting(struct rpc_xprt *xprt)
462 {
463 smp_mb__before_atomic();
464 clear_bit(XPRT_CONNECTING, &xprt->state);
465 smp_mb__after_atomic();
466 }
467
xprt_connecting(struct rpc_xprt * xprt)468 static inline int xprt_connecting(struct rpc_xprt *xprt)
469 {
470 return test_bit(XPRT_CONNECTING, &xprt->state);
471 }
472
xprt_test_and_set_connecting(struct rpc_xprt * xprt)473 static inline int xprt_test_and_set_connecting(struct rpc_xprt *xprt)
474 {
475 return test_and_set_bit(XPRT_CONNECTING, &xprt->state);
476 }
477
xprt_set_bound(struct rpc_xprt * xprt)478 static inline void xprt_set_bound(struct rpc_xprt *xprt)
479 {
480 test_and_set_bit(XPRT_BOUND, &xprt->state);
481 }
482
xprt_bound(struct rpc_xprt * xprt)483 static inline int xprt_bound(struct rpc_xprt *xprt)
484 {
485 return test_bit(XPRT_BOUND, &xprt->state);
486 }
487
xprt_clear_bound(struct rpc_xprt * xprt)488 static inline void xprt_clear_bound(struct rpc_xprt *xprt)
489 {
490 clear_bit(XPRT_BOUND, &xprt->state);
491 }
492
xprt_clear_binding(struct rpc_xprt * xprt)493 static inline void xprt_clear_binding(struct rpc_xprt *xprt)
494 {
495 smp_mb__before_atomic();
496 clear_bit(XPRT_BINDING, &xprt->state);
497 smp_mb__after_atomic();
498 }
499
xprt_test_and_set_binding(struct rpc_xprt * xprt)500 static inline int xprt_test_and_set_binding(struct rpc_xprt *xprt)
501 {
502 return test_and_set_bit(XPRT_BINDING, &xprt->state);
503 }
504
505 #endif /* _LINUX_SUNRPC_XPRT_H */
506