1 /*
2 * linux/include/linux/sunrpc/xprt.h
3 *
4 * Declarations for the RPC transport interface.
5 *
6 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
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/kref.h>
17 #include <linux/sunrpc/sched.h>
18 #include <linux/sunrpc/xdr.h>
19 #include <linux/sunrpc/msg_prot.h>
20
21 #ifdef __KERNEL__
22
23 #define RPC_MIN_SLOT_TABLE (2U)
24 #define RPC_DEF_SLOT_TABLE (16U)
25 #define RPC_MAX_SLOT_TABLE_LIMIT (65536U)
26 #define RPC_MAX_SLOT_TABLE RPC_MAX_SLOT_TABLE_LIMIT
27
28 #define RPC_CWNDSHIFT (8U)
29 #define RPC_CWNDSCALE (1U << RPC_CWNDSHIFT)
30 #define RPC_INITCWND RPC_CWNDSCALE
31 #define RPC_MAXCWND(xprt) ((xprt)->max_reqs << RPC_CWNDSHIFT)
32 #define RPCXPRT_CONGESTED(xprt) ((xprt)->cong >= (xprt)->cwnd)
33
34 /*
35 * This describes a timeout strategy
36 */
37 struct rpc_timeout {
38 unsigned long to_initval, /* initial timeout */
39 to_maxval, /* max timeout */
40 to_increment; /* if !exponential */
41 unsigned int to_retries; /* max # of retries */
42 unsigned char to_exponential;
43 };
44
45 enum rpc_display_format_t {
46 RPC_DISPLAY_ADDR = 0,
47 RPC_DISPLAY_PORT,
48 RPC_DISPLAY_PROTO,
49 RPC_DISPLAY_HEX_ADDR,
50 RPC_DISPLAY_HEX_PORT,
51 RPC_DISPLAY_NETID,
52 RPC_DISPLAY_MAX,
53 };
54
55 struct rpc_task;
56 struct rpc_xprt;
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 struct list_head rq_list;
85
86 __u32 * rq_buffer; /* XDR encode buffer */
87 size_t rq_callsize,
88 rq_rcvsize;
89 size_t rq_xmit_bytes_sent; /* total bytes sent */
90 size_t rq_reply_bytes_recvd; /* total reply bytes */
91 /* received */
92
93 struct xdr_buf rq_private_buf; /* The receive buffer
94 * used in the softirq.
95 */
96 unsigned long rq_majortimeo; /* major timeout alarm */
97 unsigned long rq_timeout; /* Current timeout value */
98 ktime_t rq_rtt; /* round-trip time */
99 unsigned int rq_retries; /* # of retries */
100 unsigned int rq_connect_cookie;
101 /* A cookie used to track the
102 state of the transport
103 connection */
104
105 /*
106 * Partial send handling
107 */
108 u32 rq_bytes_sent; /* Bytes we have sent */
109
110 ktime_t rq_xtime; /* transmit time stamp */
111 int rq_ntrans;
112
113 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
114 struct list_head rq_bc_list; /* Callback service list */
115 unsigned long rq_bc_pa_state; /* Backchannel prealloc state */
116 struct list_head rq_bc_pa_list; /* Backchannel prealloc list */
117 #endif /* CONFIG_SUNRPC_BACKCHANEL */
118 };
119 #define rq_svec rq_snd_buf.head
120 #define rq_slen rq_snd_buf.len
121
122 struct rpc_xprt_ops {
123 void (*set_buffer_size)(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize);
124 int (*reserve_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
125 void (*release_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
126 void (*alloc_slot)(struct rpc_xprt *xprt, struct rpc_task *task);
127 void (*rpcbind)(struct rpc_task *task);
128 void (*set_port)(struct rpc_xprt *xprt, unsigned short port);
129 void (*connect)(struct rpc_xprt *xprt, struct rpc_task *task);
130 void * (*buf_alloc)(struct rpc_task *task, size_t size);
131 void (*buf_free)(void *buffer);
132 int (*send_request)(struct rpc_task *task);
133 void (*set_retrans_timeout)(struct rpc_task *task);
134 void (*timer)(struct rpc_xprt *xprt, struct rpc_task *task);
135 void (*release_request)(struct rpc_task *task);
136 void (*close)(struct rpc_xprt *xprt);
137 void (*destroy)(struct rpc_xprt *xprt);
138 void (*print_stats)(struct rpc_xprt *xprt, struct seq_file *seq);
139 int (*enable_swap)(struct rpc_xprt *xprt);
140 void (*disable_swap)(struct rpc_xprt *xprt);
141 void (*inject_disconnect)(struct rpc_xprt *xprt);
142 int (*bc_setup)(struct rpc_xprt *xprt,
143 unsigned int min_reqs);
144 int (*bc_up)(struct svc_serv *serv, struct net *net);
145 size_t (*bc_maxpayload)(struct rpc_xprt *xprt);
146 void (*bc_free_rqst)(struct rpc_rqst *rqst);
147 void (*bc_destroy)(struct rpc_xprt *xprt,
148 unsigned int max_reqs);
149 };
150
151 /*
152 * RPC transport identifiers
153 *
154 * To preserve compatibility with the historical use of raw IP protocol
155 * id's for transport selection, UDP and TCP identifiers are specified
156 * with the previous values. No such restriction exists for new transports,
157 * except that they may not collide with these values (17 and 6,
158 * respectively).
159 */
160 #define XPRT_TRANSPORT_BC (1 << 31)
161 enum xprt_transports {
162 XPRT_TRANSPORT_UDP = IPPROTO_UDP,
163 XPRT_TRANSPORT_TCP = IPPROTO_TCP,
164 XPRT_TRANSPORT_BC_TCP = IPPROTO_TCP | XPRT_TRANSPORT_BC,
165 XPRT_TRANSPORT_RDMA = 256,
166 XPRT_TRANSPORT_BC_RDMA = XPRT_TRANSPORT_RDMA | XPRT_TRANSPORT_BC,
167 XPRT_TRANSPORT_LOCAL = 257,
168 };
169
170 struct rpc_xprt {
171 struct kref kref; /* Reference count */
172 struct rpc_xprt_ops * ops; /* transport methods */
173
174 const struct rpc_timeout *timeout; /* timeout parms */
175 struct sockaddr_storage addr; /* server address */
176 size_t addrlen; /* size of server address */
177 int prot; /* IP protocol */
178
179 unsigned long cong; /* current congestion */
180 unsigned long cwnd; /* congestion window */
181
182 size_t max_payload; /* largest RPC payload size,
183 in bytes */
184 unsigned int tsh_size; /* size of transport specific
185 header */
186
187 struct rpc_wait_queue binding; /* requests waiting on rpcbind */
188 struct rpc_wait_queue sending; /* requests waiting to send */
189 struct rpc_wait_queue pending; /* requests in flight */
190 struct rpc_wait_queue backlog; /* waiting for slot */
191 struct list_head free; /* free slots */
192 unsigned int max_reqs; /* max number of slots */
193 unsigned int min_reqs; /* min number of slots */
194 atomic_t num_reqs; /* total slots */
195 unsigned long state; /* transport state */
196 unsigned char resvport : 1; /* use a reserved port */
197 atomic_t swapper; /* we're swapping over this
198 transport */
199 unsigned int bind_index; /* bind function index */
200
201 /*
202 * Multipath
203 */
204 struct list_head xprt_switch;
205
206 /*
207 * Connection of transports
208 */
209 unsigned long bind_timeout,
210 reestablish_timeout;
211 unsigned int connect_cookie; /* A cookie that gets bumped
212 every time the transport
213 is reconnected */
214
215 /*
216 * Disconnection of idle transports
217 */
218 struct work_struct task_cleanup;
219 struct timer_list timer;
220 unsigned long last_used,
221 idle_timeout;
222
223 /*
224 * Send stuff
225 */
226 spinlock_t transport_lock; /* lock transport info */
227 spinlock_t reserve_lock; /* lock slot table */
228 u32 xid; /* Next XID value to use */
229 struct rpc_task * snd_task; /* Task blocked in send */
230 struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */
231 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
232 struct svc_serv *bc_serv; /* The RPC service which will */
233 /* process the callback */
234 int bc_alloc_count; /* Total number of preallocs */
235 atomic_t bc_free_slots;
236 spinlock_t bc_pa_lock; /* Protects the preallocated
237 * items */
238 struct list_head bc_pa_list; /* List of preallocated
239 * backchannel rpc_rqst's */
240 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
241 struct list_head recv;
242
243 struct {
244 unsigned long bind_count, /* total number of binds */
245 connect_count, /* total number of connects */
246 connect_start, /* connect start timestamp */
247 connect_time, /* jiffies waiting for connect */
248 sends, /* how many complete requests */
249 recvs, /* how many complete requests */
250 bad_xids, /* lookup_rqst didn't find XID */
251 max_slots; /* max rpc_slots used */
252
253 unsigned long long req_u, /* average requests on the wire */
254 bklog_u, /* backlog queue utilization */
255 sending_u, /* send q utilization */
256 pending_u; /* pend q utilization */
257 } stat;
258
259 struct net *xprt_net;
260 const char *servername;
261 const char *address_strings[RPC_DISPLAY_MAX];
262 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
263 struct dentry *debugfs; /* debugfs directory */
264 atomic_t inject_disconnect;
265 #endif
266 struct rcu_head rcu;
267 };
268
269 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
270 /*
271 * Backchannel flags
272 */
273 #define RPC_BC_PA_IN_USE 0x0001 /* Preallocated backchannel */
274 /* buffer in use */
275 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
276
277 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
278 static inline int bc_prealloc(struct rpc_rqst *req)
279 {
280 return test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
281 }
282 #else
283 static inline int bc_prealloc(struct rpc_rqst *req)
284 {
285 return 0;
286 }
287 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
288
289 #define XPRT_CREATE_INFINITE_SLOTS (1U)
290 #define XPRT_CREATE_NO_IDLE_TIMEOUT (1U << 1)
291
292 struct xprt_create {
293 int ident; /* XPRT_TRANSPORT identifier */
294 struct net * net;
295 struct sockaddr * srcaddr; /* optional local address */
296 struct sockaddr * dstaddr; /* remote peer address */
297 size_t addrlen;
298 const char *servername;
299 struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */
300 struct rpc_xprt_switch *bc_xps;
301 unsigned int flags;
302 };
303
304 struct xprt_class {
305 struct list_head list;
306 int ident; /* XPRT_TRANSPORT identifier */
307 struct rpc_xprt * (*setup)(struct xprt_create *);
308 struct module *owner;
309 char name[32];
310 };
311
312 /*
313 * Generic internal transport functions
314 */
315 struct rpc_xprt *xprt_create_transport(struct xprt_create *args);
316 void xprt_connect(struct rpc_task *task);
317 void xprt_reserve(struct rpc_task *task);
318 void xprt_retry_reserve(struct rpc_task *task);
319 int xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
320 int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
321 void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
322 void xprt_lock_and_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
323 bool xprt_prepare_transmit(struct rpc_task *task);
324 void xprt_transmit(struct rpc_task *task);
325 void xprt_end_transmit(struct rpc_task *task);
326 int xprt_adjust_timeout(struct rpc_rqst *req);
327 void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
328 void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
329 void xprt_release(struct rpc_task *task);
330 struct rpc_xprt * xprt_get(struct rpc_xprt *xprt);
331 void xprt_put(struct rpc_xprt *xprt);
332 struct rpc_xprt * xprt_alloc(struct net *net, size_t size,
333 unsigned int num_prealloc,
334 unsigned int max_req);
335 void xprt_free(struct rpc_xprt *);
336
337 static inline __be32 *xprt_skip_transport_header(struct rpc_xprt *xprt, __be32 *p)
338 {
339 return p + xprt->tsh_size;
340 }
341
342 static inline int
343 xprt_enable_swap(struct rpc_xprt *xprt)
344 {
345 return xprt->ops->enable_swap(xprt);
346 }
347
348 static inline void
349 xprt_disable_swap(struct rpc_xprt *xprt)
350 {
351 xprt->ops->disable_swap(xprt);
352 }
353
354 /*
355 * Transport switch helper functions
356 */
357 int xprt_register_transport(struct xprt_class *type);
358 int xprt_unregister_transport(struct xprt_class *type);
359 int xprt_load_transport(const char *);
360 void xprt_set_retrans_timeout_def(struct rpc_task *task);
361 void xprt_set_retrans_timeout_rtt(struct rpc_task *task);
362 void xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status);
363 void xprt_wait_for_buffer_space(struct rpc_task *task, rpc_action action);
364 void xprt_write_space(struct rpc_xprt *xprt);
365 void xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result);
366 struct rpc_rqst * xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid);
367 void xprt_complete_rqst(struct rpc_task *task, int copied);
368 void xprt_release_rqst_cong(struct rpc_task *task);
369 void xprt_disconnect_done(struct rpc_xprt *xprt);
370 void xprt_force_disconnect(struct rpc_xprt *xprt);
371 void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie);
372
373 bool xprt_lock_connect(struct rpc_xprt *, struct rpc_task *, void *);
374 void xprt_unlock_connect(struct rpc_xprt *, void *);
375
376 /*
377 * Reserved bit positions in xprt->state
378 */
379 #define XPRT_LOCKED (0)
380 #define XPRT_CONNECTED (1)
381 #define XPRT_CONNECTING (2)
382 #define XPRT_CLOSE_WAIT (3)
383 #define XPRT_BOUND (4)
384 #define XPRT_BINDING (5)
385 #define XPRT_CLOSING (6)
386 #define XPRT_CONGESTED (9)
387
388 static inline void xprt_set_connected(struct rpc_xprt *xprt)
389 {
390 set_bit(XPRT_CONNECTED, &xprt->state);
391 }
392
393 static inline void xprt_clear_connected(struct rpc_xprt *xprt)
394 {
395 clear_bit(XPRT_CONNECTED, &xprt->state);
396 }
397
398 static inline int xprt_connected(struct rpc_xprt *xprt)
399 {
400 return test_bit(XPRT_CONNECTED, &xprt->state);
401 }
402
403 static inline int xprt_test_and_set_connected(struct rpc_xprt *xprt)
404 {
405 return test_and_set_bit(XPRT_CONNECTED, &xprt->state);
406 }
407
408 static inline int xprt_test_and_clear_connected(struct rpc_xprt *xprt)
409 {
410 return test_and_clear_bit(XPRT_CONNECTED, &xprt->state);
411 }
412
413 static inline void xprt_clear_connecting(struct rpc_xprt *xprt)
414 {
415 smp_mb__before_atomic();
416 clear_bit(XPRT_CONNECTING, &xprt->state);
417 smp_mb__after_atomic();
418 }
419
420 static inline int xprt_connecting(struct rpc_xprt *xprt)
421 {
422 return test_bit(XPRT_CONNECTING, &xprt->state);
423 }
424
425 static inline int xprt_test_and_set_connecting(struct rpc_xprt *xprt)
426 {
427 return test_and_set_bit(XPRT_CONNECTING, &xprt->state);
428 }
429
430 static inline void xprt_set_bound(struct rpc_xprt *xprt)
431 {
432 test_and_set_bit(XPRT_BOUND, &xprt->state);
433 }
434
435 static inline int xprt_bound(struct rpc_xprt *xprt)
436 {
437 return test_bit(XPRT_BOUND, &xprt->state);
438 }
439
440 static inline void xprt_clear_bound(struct rpc_xprt *xprt)
441 {
442 clear_bit(XPRT_BOUND, &xprt->state);
443 }
444
445 static inline void xprt_clear_binding(struct rpc_xprt *xprt)
446 {
447 smp_mb__before_atomic();
448 clear_bit(XPRT_BINDING, &xprt->state);
449 smp_mb__after_atomic();
450 }
451
452 static inline int xprt_test_and_set_binding(struct rpc_xprt *xprt)
453 {
454 return test_and_set_bit(XPRT_BINDING, &xprt->state);
455 }
456
457 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
458 extern unsigned int rpc_inject_disconnect;
459 static inline void xprt_inject_disconnect(struct rpc_xprt *xprt)
460 {
461 if (!rpc_inject_disconnect)
462 return;
463 if (atomic_dec_return(&xprt->inject_disconnect))
464 return;
465 atomic_set(&xprt->inject_disconnect, rpc_inject_disconnect);
466 xprt->ops->inject_disconnect(xprt);
467 }
468 #else
469 static inline void xprt_inject_disconnect(struct rpc_xprt *xprt)
470 {
471 }
472 #endif
473
474 #endif /* __KERNEL__*/
475
476 #endif /* _LINUX_SUNRPC_XPRT_H */
477
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