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 (*get_srcaddr)(struct rpc_xprt *xprt, char *buf,
143 size_t buflen);
144 unsigned short (*get_srcport)(struct rpc_xprt *xprt);
145 int (*buf_alloc)(struct rpc_task *task);
146 void (*buf_free)(struct rpc_task *task);
147 int (*prepare_request)(struct rpc_rqst *req,
148 struct xdr_buf *buf);
149 int (*send_request)(struct rpc_rqst *req);
150 void (*wait_for_reply_request)(struct rpc_task *task);
151 void (*timer)(struct rpc_xprt *xprt, struct rpc_task *task);
152 void (*release_request)(struct rpc_task *task);
153 void (*close)(struct rpc_xprt *xprt);
154 void (*destroy)(struct rpc_xprt *xprt);
155 void (*set_connect_timeout)(struct rpc_xprt *xprt,
156 unsigned long connect_timeout,
157 unsigned long reconnect_timeout);
158 void (*print_stats)(struct rpc_xprt *xprt, struct seq_file *seq);
159 int (*enable_swap)(struct rpc_xprt *xprt);
160 void (*disable_swap)(struct rpc_xprt *xprt);
161 void (*inject_disconnect)(struct rpc_xprt *xprt);
162 int (*bc_setup)(struct rpc_xprt *xprt,
163 unsigned int min_reqs);
164 size_t (*bc_maxpayload)(struct rpc_xprt *xprt);
165 unsigned int (*bc_num_slots)(struct rpc_xprt *xprt);
166 void (*bc_free_rqst)(struct rpc_rqst *rqst);
167 void (*bc_destroy)(struct rpc_xprt *xprt,
168 unsigned int max_reqs);
169 };
170
171 /*
172 * RPC transport identifiers
173 *
174 * To preserve compatibility with the historical use of raw IP protocol
175 * id's for transport selection, UDP and TCP identifiers are specified
176 * with the previous values. No such restriction exists for new transports,
177 * except that they may not collide with these values (17 and 6,
178 * respectively).
179 */
180 #define XPRT_TRANSPORT_BC (1 << 31)
181 enum xprt_transports {
182 XPRT_TRANSPORT_UDP = IPPROTO_UDP,
183 XPRT_TRANSPORT_TCP = IPPROTO_TCP,
184 XPRT_TRANSPORT_BC_TCP = IPPROTO_TCP | XPRT_TRANSPORT_BC,
185 XPRT_TRANSPORT_RDMA = 256,
186 XPRT_TRANSPORT_BC_RDMA = XPRT_TRANSPORT_RDMA | XPRT_TRANSPORT_BC,
187 XPRT_TRANSPORT_LOCAL = 257,
188 };
189
190 struct rpc_sysfs_xprt;
191 struct rpc_xprt {
192 struct kref kref; /* Reference count */
193 const struct rpc_xprt_ops *ops; /* transport methods */
194 unsigned int id; /* transport id */
195
196 const struct rpc_timeout *timeout; /* timeout parms */
197 struct sockaddr_storage addr; /* server address */
198 size_t addrlen; /* size of server address */
199 int prot; /* IP protocol */
200
201 unsigned long cong; /* current congestion */
202 unsigned long cwnd; /* congestion window */
203
204 size_t max_payload; /* largest RPC payload size,
205 in bytes */
206
207 struct rpc_wait_queue binding; /* requests waiting on rpcbind */
208 struct rpc_wait_queue sending; /* requests waiting to send */
209 struct rpc_wait_queue pending; /* requests in flight */
210 struct rpc_wait_queue backlog; /* waiting for slot */
211 struct list_head free; /* free slots */
212 unsigned int max_reqs; /* max number of slots */
213 unsigned int min_reqs; /* min number of slots */
214 unsigned int num_reqs; /* total slots */
215 unsigned long state; /* transport state */
216 unsigned char resvport : 1, /* use a reserved port */
217 reuseport : 1; /* reuse port on reconnect */
218 atomic_t swapper; /* we're swapping over this
219 transport */
220 unsigned int bind_index; /* bind function index */
221
222 /*
223 * Multipath
224 */
225 struct list_head xprt_switch;
226
227 /*
228 * Connection of transports
229 */
230 unsigned long bind_timeout,
231 reestablish_timeout;
232 unsigned int connect_cookie; /* A cookie that gets bumped
233 every time the transport
234 is reconnected */
235
236 /*
237 * Disconnection of idle transports
238 */
239 struct work_struct task_cleanup;
240 struct timer_list timer;
241 unsigned long last_used,
242 idle_timeout,
243 connect_timeout,
244 max_reconnect_timeout;
245
246 /*
247 * Send stuff
248 */
249 atomic_long_t queuelen;
250 spinlock_t transport_lock; /* lock transport info */
251 spinlock_t reserve_lock; /* lock slot table */
252 spinlock_t queue_lock; /* send/receive queue lock */
253 u32 xid; /* Next XID value to use */
254 struct rpc_task * snd_task; /* Task blocked in send */
255
256 struct list_head xmit_queue; /* Send queue */
257 atomic_long_t xmit_queuelen;
258
259 struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */
260 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
261 struct svc_serv *bc_serv; /* The RPC service which will */
262 /* process the callback */
263 unsigned int bc_alloc_max;
264 unsigned int bc_alloc_count; /* Total number of preallocs */
265 atomic_t bc_slot_count; /* Number of allocated slots */
266 spinlock_t bc_pa_lock; /* Protects the preallocated
267 * items */
268 struct list_head bc_pa_list; /* List of preallocated
269 * backchannel rpc_rqst's */
270 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
271
272 struct rb_root recv_queue; /* Receive queue */
273
274 struct {
275 unsigned long bind_count, /* total number of binds */
276 connect_count, /* total number of connects */
277 connect_start, /* connect start timestamp */
278 connect_time, /* jiffies waiting for connect */
279 sends, /* how many complete requests */
280 recvs, /* how many complete requests */
281 bad_xids, /* lookup_rqst didn't find XID */
282 max_slots; /* max rpc_slots used */
283
284 unsigned long long req_u, /* average requests on the wire */
285 bklog_u, /* backlog queue utilization */
286 sending_u, /* send q utilization */
287 pending_u; /* pend q utilization */
288 } stat;
289
290 struct net *xprt_net;
291 netns_tracker ns_tracker;
292 const char *servername;
293 const char *address_strings[RPC_DISPLAY_MAX];
294 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
295 struct dentry *debugfs; /* debugfs directory */
296 #endif
297 struct rcu_head rcu;
298 const struct xprt_class *xprt_class;
299 struct rpc_sysfs_xprt *xprt_sysfs;
300 bool main; /*mark if this is the 1st transport */
301 };
302
303 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
304 /*
305 * Backchannel flags
306 */
307 #define RPC_BC_PA_IN_USE 0x0001 /* Preallocated backchannel */
308 /* buffer in use */
309 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
310
311 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
bc_prealloc(struct rpc_rqst * req)312 static inline int bc_prealloc(struct rpc_rqst *req)
313 {
314 return test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
315 }
316 #else
bc_prealloc(struct rpc_rqst * req)317 static inline int bc_prealloc(struct rpc_rqst *req)
318 {
319 return 0;
320 }
321 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
322
323 #define XPRT_CREATE_INFINITE_SLOTS (1U)
324 #define XPRT_CREATE_NO_IDLE_TIMEOUT (1U << 1)
325
326 struct xprt_create {
327 int ident; /* XPRT_TRANSPORT identifier */
328 struct net * net;
329 struct sockaddr * srcaddr; /* optional local address */
330 struct sockaddr * dstaddr; /* remote peer address */
331 size_t addrlen;
332 const char *servername;
333 struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */
334 struct rpc_xprt_switch *bc_xps;
335 unsigned int flags;
336 };
337
338 struct xprt_class {
339 struct list_head list;
340 int ident; /* XPRT_TRANSPORT identifier */
341 struct rpc_xprt * (*setup)(struct xprt_create *);
342 struct module *owner;
343 char name[32];
344 const char * netid[];
345 };
346
347 /*
348 * Generic internal transport functions
349 */
350 struct rpc_xprt *xprt_create_transport(struct xprt_create *args);
351 void xprt_connect(struct rpc_task *task);
352 unsigned long xprt_reconnect_delay(const struct rpc_xprt *xprt);
353 void xprt_reconnect_backoff(struct rpc_xprt *xprt,
354 unsigned long init_to);
355 void xprt_reserve(struct rpc_task *task);
356 void xprt_retry_reserve(struct rpc_task *task);
357 int xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
358 int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
359 void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
360 void xprt_free_slot(struct rpc_xprt *xprt,
361 struct rpc_rqst *req);
362 bool xprt_prepare_transmit(struct rpc_task *task);
363 void xprt_request_enqueue_transmit(struct rpc_task *task);
364 int xprt_request_enqueue_receive(struct rpc_task *task);
365 void xprt_request_wait_receive(struct rpc_task *task);
366 void xprt_request_dequeue_xprt(struct rpc_task *task);
367 bool xprt_request_need_retransmit(struct rpc_task *task);
368 void xprt_transmit(struct rpc_task *task);
369 void xprt_end_transmit(struct rpc_task *task);
370 int xprt_adjust_timeout(struct rpc_rqst *req);
371 void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
372 void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
373 void xprt_release(struct rpc_task *task);
374 struct rpc_xprt * xprt_get(struct rpc_xprt *xprt);
375 void xprt_put(struct rpc_xprt *xprt);
376 struct rpc_xprt * xprt_alloc(struct net *net, size_t size,
377 unsigned int num_prealloc,
378 unsigned int max_req);
379 void xprt_free(struct rpc_xprt *);
380 void xprt_add_backlog(struct rpc_xprt *xprt, struct rpc_task *task);
381 bool xprt_wake_up_backlog(struct rpc_xprt *xprt, struct rpc_rqst *req);
382 void xprt_cleanup_ids(void);
383
384 static inline int
xprt_enable_swap(struct rpc_xprt * xprt)385 xprt_enable_swap(struct rpc_xprt *xprt)
386 {
387 return xprt->ops->enable_swap(xprt);
388 }
389
390 static inline void
xprt_disable_swap(struct rpc_xprt * xprt)391 xprt_disable_swap(struct rpc_xprt *xprt)
392 {
393 xprt->ops->disable_swap(xprt);
394 }
395
396 /*
397 * Transport switch helper functions
398 */
399 int xprt_register_transport(struct xprt_class *type);
400 int xprt_unregister_transport(struct xprt_class *type);
401 int xprt_find_transport_ident(const char *);
402 void xprt_wait_for_reply_request_def(struct rpc_task *task);
403 void xprt_wait_for_reply_request_rtt(struct rpc_task *task);
404 void xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status);
405 void xprt_wait_for_buffer_space(struct rpc_xprt *xprt);
406 bool xprt_write_space(struct rpc_xprt *xprt);
407 void xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result);
408 struct rpc_rqst * xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid);
409 void xprt_update_rtt(struct rpc_task *task);
410 void xprt_complete_rqst(struct rpc_task *task, int copied);
411 void xprt_pin_rqst(struct rpc_rqst *req);
412 void xprt_unpin_rqst(struct rpc_rqst *req);
413 void xprt_release_rqst_cong(struct rpc_task *task);
414 bool xprt_request_get_cong(struct rpc_xprt *xprt, struct rpc_rqst *req);
415 void xprt_disconnect_done(struct rpc_xprt *xprt);
416 void xprt_force_disconnect(struct rpc_xprt *xprt);
417 void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie);
418
419 bool xprt_lock_connect(struct rpc_xprt *, struct rpc_task *, void *);
420 void xprt_unlock_connect(struct rpc_xprt *, void *);
421 void xprt_release_write(struct rpc_xprt *, struct rpc_task *);
422
423 /*
424 * Reserved bit positions in xprt->state
425 */
426 #define XPRT_LOCKED (0)
427 #define XPRT_CONNECTED (1)
428 #define XPRT_CONNECTING (2)
429 #define XPRT_CLOSE_WAIT (3)
430 #define XPRT_BOUND (4)
431 #define XPRT_BINDING (5)
432 #define XPRT_CLOSING (6)
433 #define XPRT_OFFLINE (7)
434 #define XPRT_REMOVE (8)
435 #define XPRT_CONGESTED (9)
436 #define XPRT_CWND_WAIT (10)
437 #define XPRT_WRITE_SPACE (11)
438 #define XPRT_SND_IS_COOKIE (12)
439
xprt_set_connected(struct rpc_xprt * xprt)440 static inline void xprt_set_connected(struct rpc_xprt *xprt)
441 {
442 set_bit(XPRT_CONNECTED, &xprt->state);
443 }
444
xprt_clear_connected(struct rpc_xprt * xprt)445 static inline void xprt_clear_connected(struct rpc_xprt *xprt)
446 {
447 clear_bit(XPRT_CONNECTED, &xprt->state);
448 }
449
xprt_connected(struct rpc_xprt * xprt)450 static inline int xprt_connected(struct rpc_xprt *xprt)
451 {
452 return test_bit(XPRT_CONNECTED, &xprt->state);
453 }
454
xprt_test_and_set_connected(struct rpc_xprt * xprt)455 static inline int xprt_test_and_set_connected(struct rpc_xprt *xprt)
456 {
457 return test_and_set_bit(XPRT_CONNECTED, &xprt->state);
458 }
459
xprt_test_and_clear_connected(struct rpc_xprt * xprt)460 static inline int xprt_test_and_clear_connected(struct rpc_xprt *xprt)
461 {
462 return test_and_clear_bit(XPRT_CONNECTED, &xprt->state);
463 }
464
xprt_clear_connecting(struct rpc_xprt * xprt)465 static inline void xprt_clear_connecting(struct rpc_xprt *xprt)
466 {
467 smp_mb__before_atomic();
468 clear_bit(XPRT_CONNECTING, &xprt->state);
469 smp_mb__after_atomic();
470 }
471
xprt_connecting(struct rpc_xprt * xprt)472 static inline int xprt_connecting(struct rpc_xprt *xprt)
473 {
474 return test_bit(XPRT_CONNECTING, &xprt->state);
475 }
476
xprt_test_and_set_connecting(struct rpc_xprt * xprt)477 static inline int xprt_test_and_set_connecting(struct rpc_xprt *xprt)
478 {
479 return test_and_set_bit(XPRT_CONNECTING, &xprt->state);
480 }
481
xprt_set_bound(struct rpc_xprt * xprt)482 static inline void xprt_set_bound(struct rpc_xprt *xprt)
483 {
484 test_and_set_bit(XPRT_BOUND, &xprt->state);
485 }
486
xprt_bound(struct rpc_xprt * xprt)487 static inline int xprt_bound(struct rpc_xprt *xprt)
488 {
489 return test_bit(XPRT_BOUND, &xprt->state);
490 }
491
xprt_clear_bound(struct rpc_xprt * xprt)492 static inline void xprt_clear_bound(struct rpc_xprt *xprt)
493 {
494 clear_bit(XPRT_BOUND, &xprt->state);
495 }
496
xprt_clear_binding(struct rpc_xprt * xprt)497 static inline void xprt_clear_binding(struct rpc_xprt *xprt)
498 {
499 smp_mb__before_atomic();
500 clear_bit(XPRT_BINDING, &xprt->state);
501 smp_mb__after_atomic();
502 }
503
xprt_test_and_set_binding(struct rpc_xprt * xprt)504 static inline int xprt_test_and_set_binding(struct rpc_xprt *xprt)
505 {
506 return test_and_set_bit(XPRT_BINDING, &xprt->state);
507 }
508
509 #endif /* _LINUX_SUNRPC_XPRT_H */
510