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/sunrpc/sched.h>
17 #include <linux/sunrpc/xdr.h>
18 #include <linux/sunrpc/msg_prot.h>
19
20 #ifdef __KERNEL__
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 struct list_head rq_list;
84
85 __u32 * rq_buffer; /* XDR encode buffer */
86 size_t rq_callsize,
87 rq_rcvsize;
88 size_t rq_xmit_bytes_sent; /* total bytes sent */
89 size_t rq_reply_bytes_recvd; /* total reply bytes */
90 /* received */
91
92 struct xdr_buf rq_private_buf; /* The receive buffer
93 * used in the softirq.
94 */
95 unsigned long rq_majortimeo; /* major timeout alarm */
96 unsigned long rq_timeout; /* Current timeout value */
97 ktime_t rq_rtt; /* round-trip time */
98 unsigned int rq_retries; /* # of retries */
99 unsigned int rq_connect_cookie;
100 /* A cookie used to track the
101 state of the transport
102 connection */
103
104 /*
105 * Partial send handling
106 */
107 u32 rq_bytes_sent; /* Bytes we have sent */
108
109 ktime_t rq_xtime; /* transmit time stamp */
110 int rq_ntrans;
111
112 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
113 struct list_head rq_bc_list; /* Callback service list */
114 unsigned long rq_bc_pa_state; /* Backchannel prealloc state */
115 struct list_head rq_bc_pa_list; /* Backchannel prealloc list */
116 #endif /* CONFIG_SUNRPC_BACKCHANEL */
117 };
118 #define rq_svec rq_snd_buf.head
119 #define rq_slen rq_snd_buf.len
120
121 struct rpc_xprt_ops {
122 void (*set_buffer_size)(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize);
123 int (*reserve_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
124 void (*release_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
125 void (*alloc_slot)(struct rpc_xprt *xprt, struct rpc_task *task);
126 void (*rpcbind)(struct rpc_task *task);
127 void (*set_port)(struct rpc_xprt *xprt, unsigned short port);
128 void (*connect)(struct rpc_xprt *xprt, struct rpc_task *task);
129 void * (*buf_alloc)(struct rpc_task *task, size_t size);
130 void (*buf_free)(void *buffer);
131 int (*send_request)(struct rpc_task *task);
132 void (*set_retrans_timeout)(struct rpc_task *task);
133 void (*timer)(struct rpc_xprt *xprt, struct rpc_task *task);
134 void (*release_request)(struct rpc_task *task);
135 void (*close)(struct rpc_xprt *xprt);
136 void (*destroy)(struct rpc_xprt *xprt);
137 void (*print_stats)(struct rpc_xprt *xprt, struct seq_file *seq);
138 int (*enable_swap)(struct rpc_xprt *xprt);
139 void (*disable_swap)(struct rpc_xprt *xprt);
140 void (*inject_disconnect)(struct rpc_xprt *xprt);
141 int (*bc_setup)(struct rpc_xprt *xprt,
142 unsigned int min_reqs);
143 int (*bc_up)(struct svc_serv *serv, struct net *net);
144 void (*bc_free_rqst)(struct rpc_rqst *rqst);
145 void (*bc_destroy)(struct rpc_xprt *xprt,
146 unsigned int max_reqs);
147 };
148
149 /*
150 * RPC transport identifiers
151 *
152 * To preserve compatibility with the historical use of raw IP protocol
153 * id's for transport selection, UDP and TCP identifiers are specified
154 * with the previous values. No such restriction exists for new transports,
155 * except that they may not collide with these values (17 and 6,
156 * respectively).
157 */
158 #define XPRT_TRANSPORT_BC (1 << 31)
159 enum xprt_transports {
160 XPRT_TRANSPORT_UDP = IPPROTO_UDP,
161 XPRT_TRANSPORT_TCP = IPPROTO_TCP,
162 XPRT_TRANSPORT_BC_TCP = IPPROTO_TCP | XPRT_TRANSPORT_BC,
163 XPRT_TRANSPORT_RDMA = 256,
164 XPRT_TRANSPORT_BC_RDMA = XPRT_TRANSPORT_RDMA | XPRT_TRANSPORT_BC,
165 XPRT_TRANSPORT_LOCAL = 257,
166 };
167
168 struct rpc_xprt {
169 atomic_t count; /* Reference count */
170 struct rpc_xprt_ops * ops; /* transport methods */
171
172 const struct rpc_timeout *timeout; /* timeout parms */
173 struct sockaddr_storage addr; /* server address */
174 size_t addrlen; /* size of server address */
175 int prot; /* IP protocol */
176
177 unsigned long cong; /* current congestion */
178 unsigned long cwnd; /* congestion window */
179
180 size_t max_payload; /* largest RPC payload size,
181 in bytes */
182 unsigned int tsh_size; /* size of transport specific
183 header */
184
185 struct rpc_wait_queue binding; /* requests waiting on rpcbind */
186 struct rpc_wait_queue sending; /* requests waiting to send */
187 struct rpc_wait_queue pending; /* requests in flight */
188 struct rpc_wait_queue backlog; /* waiting for slot */
189 struct list_head free; /* free slots */
190 unsigned int max_reqs; /* max number of slots */
191 unsigned int min_reqs; /* min number of slots */
192 atomic_t num_reqs; /* total slots */
193 unsigned long state; /* transport state */
194 unsigned char resvport : 1; /* use a reserved port */
195 atomic_t swapper; /* we're swapping over this
196 transport */
197 unsigned int bind_index; /* bind function index */
198
199 /*
200 * Connection of transports
201 */
202 unsigned long bind_timeout,
203 reestablish_timeout;
204 unsigned int connect_cookie; /* A cookie that gets bumped
205 every time the transport
206 is reconnected */
207
208 /*
209 * Disconnection of idle transports
210 */
211 struct work_struct task_cleanup;
212 struct timer_list timer;
213 unsigned long last_used,
214 idle_timeout;
215
216 /*
217 * Send stuff
218 */
219 spinlock_t transport_lock; /* lock transport info */
220 spinlock_t reserve_lock; /* lock slot table */
221 u32 xid; /* Next XID value to use */
222 struct rpc_task * snd_task; /* Task blocked in send */
223 struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */
224 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
225 struct svc_serv *bc_serv; /* The RPC service which will */
226 /* process the callback */
227 int bc_alloc_count; /* Total number of preallocs */
228 atomic_t bc_free_slots;
229 spinlock_t bc_pa_lock; /* Protects the preallocated
230 * items */
231 struct list_head bc_pa_list; /* List of preallocated
232 * backchannel rpc_rqst's */
233 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
234 struct list_head recv;
235
236 struct {
237 unsigned long bind_count, /* total number of binds */
238 connect_count, /* total number of connects */
239 connect_start, /* connect start timestamp */
240 connect_time, /* jiffies waiting for connect */
241 sends, /* how many complete requests */
242 recvs, /* how many complete requests */
243 bad_xids, /* lookup_rqst didn't find XID */
244 max_slots; /* max rpc_slots used */
245
246 unsigned long long req_u, /* average requests on the wire */
247 bklog_u, /* backlog queue utilization */
248 sending_u, /* send q utilization */
249 pending_u; /* pend q utilization */
250 } stat;
251
252 struct net *xprt_net;
253 const char *servername;
254 const char *address_strings[RPC_DISPLAY_MAX];
255 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
256 struct dentry *debugfs; /* debugfs directory */
257 atomic_t inject_disconnect;
258 #endif
259 };
260
261 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
262 /*
263 * Backchannel flags
264 */
265 #define RPC_BC_PA_IN_USE 0x0001 /* Preallocated backchannel */
266 /* buffer in use */
267 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
268
269 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
bc_prealloc(struct rpc_rqst * req)270 static inline int bc_prealloc(struct rpc_rqst *req)
271 {
272 return test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
273 }
274 #else
bc_prealloc(struct rpc_rqst * req)275 static inline int bc_prealloc(struct rpc_rqst *req)
276 {
277 return 0;
278 }
279 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
280
281 #define XPRT_CREATE_INFINITE_SLOTS (1U)
282 #define XPRT_CREATE_NO_IDLE_TIMEOUT (1U << 1)
283
284 struct xprt_create {
285 int ident; /* XPRT_TRANSPORT identifier */
286 struct net * net;
287 struct sockaddr * srcaddr; /* optional local address */
288 struct sockaddr * dstaddr; /* remote peer address */
289 size_t addrlen;
290 const char *servername;
291 struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */
292 unsigned int flags;
293 };
294
295 struct xprt_class {
296 struct list_head list;
297 int ident; /* XPRT_TRANSPORT identifier */
298 struct rpc_xprt * (*setup)(struct xprt_create *);
299 struct module *owner;
300 char name[32];
301 };
302
303 /*
304 * Generic internal transport functions
305 */
306 struct rpc_xprt *xprt_create_transport(struct xprt_create *args);
307 void xprt_connect(struct rpc_task *task);
308 void xprt_reserve(struct rpc_task *task);
309 void xprt_retry_reserve(struct rpc_task *task);
310 int xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
311 int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
312 void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
313 void xprt_lock_and_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
314 bool xprt_prepare_transmit(struct rpc_task *task);
315 void xprt_transmit(struct rpc_task *task);
316 void xprt_end_transmit(struct rpc_task *task);
317 int xprt_adjust_timeout(struct rpc_rqst *req);
318 void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
319 void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
320 void xprt_release(struct rpc_task *task);
321 void xprt_put(struct rpc_xprt *xprt);
322 struct rpc_xprt * xprt_alloc(struct net *net, size_t size,
323 unsigned int num_prealloc,
324 unsigned int max_req);
325 void xprt_free(struct rpc_xprt *);
326
327 /**
328 * xprt_get - return a reference to an RPC transport.
329 * @xprt: pointer to the transport
330 *
331 */
xprt_get(struct rpc_xprt * xprt)332 static inline struct rpc_xprt *xprt_get(struct rpc_xprt *xprt)
333 {
334 if (atomic_inc_not_zero(&xprt->count))
335 return xprt;
336 return NULL;
337 }
338
xprt_skip_transport_header(struct rpc_xprt * xprt,__be32 * p)339 static inline __be32 *xprt_skip_transport_header(struct rpc_xprt *xprt, __be32 *p)
340 {
341 return p + xprt->tsh_size;
342 }
343
344 static inline int
xprt_enable_swap(struct rpc_xprt * xprt)345 xprt_enable_swap(struct rpc_xprt *xprt)
346 {
347 return xprt->ops->enable_swap(xprt);
348 }
349
350 static inline void
xprt_disable_swap(struct rpc_xprt * xprt)351 xprt_disable_swap(struct rpc_xprt *xprt)
352 {
353 xprt->ops->disable_swap(xprt);
354 }
355
356 /*
357 * Transport switch helper functions
358 */
359 int xprt_register_transport(struct xprt_class *type);
360 int xprt_unregister_transport(struct xprt_class *type);
361 int xprt_load_transport(const char *);
362 void xprt_set_retrans_timeout_def(struct rpc_task *task);
363 void xprt_set_retrans_timeout_rtt(struct rpc_task *task);
364 void xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status);
365 void xprt_wait_for_buffer_space(struct rpc_task *task, rpc_action action);
366 void xprt_write_space(struct rpc_xprt *xprt);
367 void xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result);
368 struct rpc_rqst * xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid);
369 void xprt_complete_rqst(struct rpc_task *task, int copied);
370 void xprt_release_rqst_cong(struct rpc_task *task);
371 void xprt_disconnect_done(struct rpc_xprt *xprt);
372 void xprt_force_disconnect(struct rpc_xprt *xprt);
373 void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie);
374
375 bool xprt_lock_connect(struct rpc_xprt *, struct rpc_task *, void *);
376 void xprt_unlock_connect(struct rpc_xprt *, void *);
377
378 /*
379 * Reserved bit positions in xprt->state
380 */
381 #define XPRT_LOCKED (0)
382 #define XPRT_CONNECTED (1)
383 #define XPRT_CONNECTING (2)
384 #define XPRT_CLOSE_WAIT (3)
385 #define XPRT_BOUND (4)
386 #define XPRT_BINDING (5)
387 #define XPRT_CLOSING (6)
388 #define XPRT_CONGESTED (9)
389
xprt_set_connected(struct rpc_xprt * xprt)390 static inline void xprt_set_connected(struct rpc_xprt *xprt)
391 {
392 set_bit(XPRT_CONNECTED, &xprt->state);
393 }
394
xprt_clear_connected(struct rpc_xprt * xprt)395 static inline void xprt_clear_connected(struct rpc_xprt *xprt)
396 {
397 clear_bit(XPRT_CONNECTED, &xprt->state);
398 }
399
xprt_connected(struct rpc_xprt * xprt)400 static inline int xprt_connected(struct rpc_xprt *xprt)
401 {
402 return test_bit(XPRT_CONNECTED, &xprt->state);
403 }
404
xprt_test_and_set_connected(struct rpc_xprt * xprt)405 static inline int xprt_test_and_set_connected(struct rpc_xprt *xprt)
406 {
407 return test_and_set_bit(XPRT_CONNECTED, &xprt->state);
408 }
409
xprt_test_and_clear_connected(struct rpc_xprt * xprt)410 static inline int xprt_test_and_clear_connected(struct rpc_xprt *xprt)
411 {
412 return test_and_clear_bit(XPRT_CONNECTED, &xprt->state);
413 }
414
xprt_clear_connecting(struct rpc_xprt * xprt)415 static inline void xprt_clear_connecting(struct rpc_xprt *xprt)
416 {
417 smp_mb__before_atomic();
418 clear_bit(XPRT_CONNECTING, &xprt->state);
419 smp_mb__after_atomic();
420 }
421
xprt_connecting(struct rpc_xprt * xprt)422 static inline int xprt_connecting(struct rpc_xprt *xprt)
423 {
424 return test_bit(XPRT_CONNECTING, &xprt->state);
425 }
426
xprt_test_and_set_connecting(struct rpc_xprt * xprt)427 static inline int xprt_test_and_set_connecting(struct rpc_xprt *xprt)
428 {
429 return test_and_set_bit(XPRT_CONNECTING, &xprt->state);
430 }
431
xprt_set_bound(struct rpc_xprt * xprt)432 static inline void xprt_set_bound(struct rpc_xprt *xprt)
433 {
434 test_and_set_bit(XPRT_BOUND, &xprt->state);
435 }
436
xprt_bound(struct rpc_xprt * xprt)437 static inline int xprt_bound(struct rpc_xprt *xprt)
438 {
439 return test_bit(XPRT_BOUND, &xprt->state);
440 }
441
xprt_clear_bound(struct rpc_xprt * xprt)442 static inline void xprt_clear_bound(struct rpc_xprt *xprt)
443 {
444 clear_bit(XPRT_BOUND, &xprt->state);
445 }
446
xprt_clear_binding(struct rpc_xprt * xprt)447 static inline void xprt_clear_binding(struct rpc_xprt *xprt)
448 {
449 smp_mb__before_atomic();
450 clear_bit(XPRT_BINDING, &xprt->state);
451 smp_mb__after_atomic();
452 }
453
xprt_test_and_set_binding(struct rpc_xprt * xprt)454 static inline int xprt_test_and_set_binding(struct rpc_xprt *xprt)
455 {
456 return test_and_set_bit(XPRT_BINDING, &xprt->state);
457 }
458
459 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
460 extern unsigned int rpc_inject_disconnect;
xprt_inject_disconnect(struct rpc_xprt * xprt)461 static inline void xprt_inject_disconnect(struct rpc_xprt *xprt)
462 {
463 if (!rpc_inject_disconnect)
464 return;
465 if (atomic_dec_return(&xprt->inject_disconnect))
466 return;
467 atomic_set(&xprt->inject_disconnect, rpc_inject_disconnect);
468 xprt->ops->inject_disconnect(xprt);
469 }
470 #else
xprt_inject_disconnect(struct rpc_xprt * xprt)471 static inline void xprt_inject_disconnect(struct rpc_xprt *xprt)
472 {
473 }
474 #endif
475
476 #endif /* __KERNEL__*/
477
478 #endif /* _LINUX_SUNRPC_XPRT_H */
479