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
58 /*
59 * This describes a complete RPC request
60 */
61 struct rpc_rqst {
62 /*
63 * This is the user-visible part
64 */
65 struct rpc_xprt * rq_xprt; /* RPC client */
66 struct xdr_buf rq_snd_buf; /* send buffer */
67 struct xdr_buf rq_rcv_buf; /* recv buffer */
68
69 /*
70 * This is the private part
71 */
72 struct rpc_task * rq_task; /* RPC task data */
73 struct rpc_cred * rq_cred; /* Bound cred */
74 __be32 rq_xid; /* request XID */
75 int rq_cong; /* has incremented xprt->cong */
76 u32 rq_seqno; /* gss seq no. used on req. */
77 int rq_enc_pages_num;
78 struct page **rq_enc_pages; /* scratch pages for use by
79 gss privacy code */
80 void (*rq_release_snd_buf)(struct rpc_rqst *); /* release rq_enc_pages */
81 struct list_head rq_list;
82
83 __u32 * rq_buffer; /* XDR encode buffer */
84 size_t rq_callsize,
85 rq_rcvsize;
86 size_t rq_xmit_bytes_sent; /* total bytes sent */
87 size_t rq_reply_bytes_recvd; /* total reply bytes */
88 /* received */
89
90 struct xdr_buf rq_private_buf; /* The receive buffer
91 * used in the softirq.
92 */
93 unsigned long rq_majortimeo; /* major timeout alarm */
94 unsigned long rq_timeout; /* Current timeout value */
95 ktime_t rq_rtt; /* round-trip time */
96 unsigned int rq_retries; /* # of retries */
97 unsigned int rq_connect_cookie;
98 /* A cookie used to track the
99 state of the transport
100 connection */
101
102 /*
103 * Partial send handling
104 */
105 u32 rq_bytes_sent; /* Bytes we have sent */
106
107 ktime_t rq_xtime; /* transmit time stamp */
108 int rq_ntrans;
109
110 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
111 struct list_head rq_bc_list; /* Callback service list */
112 unsigned long rq_bc_pa_state; /* Backchannel prealloc state */
113 struct list_head rq_bc_pa_list; /* Backchannel prealloc list */
114 #endif /* CONFIG_SUNRPC_BACKCHANEL */
115 };
116 #define rq_svec rq_snd_buf.head
117 #define rq_slen rq_snd_buf.len
118
119 struct rpc_xprt_ops {
120 void (*set_buffer_size)(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize);
121 int (*reserve_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
122 void (*release_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
123 void (*alloc_slot)(struct rpc_xprt *xprt, struct rpc_task *task);
124 void (*rpcbind)(struct rpc_task *task);
125 void (*set_port)(struct rpc_xprt *xprt, unsigned short port);
126 void (*connect)(struct rpc_xprt *xprt, struct rpc_task *task);
127 void * (*buf_alloc)(struct rpc_task *task, size_t size);
128 void (*buf_free)(void *buffer);
129 int (*send_request)(struct rpc_task *task);
130 void (*set_retrans_timeout)(struct rpc_task *task);
131 void (*timer)(struct rpc_xprt *xprt, struct rpc_task *task);
132 void (*release_request)(struct rpc_task *task);
133 void (*close)(struct rpc_xprt *xprt);
134 void (*destroy)(struct rpc_xprt *xprt);
135 void (*print_stats)(struct rpc_xprt *xprt, struct seq_file *seq);
136 };
137
138 /*
139 * RPC transport identifiers
140 *
141 * To preserve compatibility with the historical use of raw IP protocol
142 * id's for transport selection, UDP and TCP identifiers are specified
143 * with the previous values. No such restriction exists for new transports,
144 * except that they may not collide with these values (17 and 6,
145 * respectively).
146 */
147 #define XPRT_TRANSPORT_BC (1 << 31)
148 enum xprt_transports {
149 XPRT_TRANSPORT_UDP = IPPROTO_UDP,
150 XPRT_TRANSPORT_TCP = IPPROTO_TCP,
151 XPRT_TRANSPORT_BC_TCP = IPPROTO_TCP | XPRT_TRANSPORT_BC,
152 XPRT_TRANSPORT_RDMA = 256,
153 XPRT_TRANSPORT_LOCAL = 257,
154 };
155
156 struct rpc_xprt {
157 atomic_t count; /* Reference count */
158 struct rpc_xprt_ops * ops; /* transport methods */
159
160 const struct rpc_timeout *timeout; /* timeout parms */
161 struct sockaddr_storage addr; /* server address */
162 size_t addrlen; /* size of server address */
163 int prot; /* IP protocol */
164
165 unsigned long cong; /* current congestion */
166 unsigned long cwnd; /* congestion window */
167
168 size_t max_payload; /* largest RPC payload size,
169 in bytes */
170 unsigned int tsh_size; /* size of transport specific
171 header */
172
173 struct rpc_wait_queue binding; /* requests waiting on rpcbind */
174 struct rpc_wait_queue sending; /* requests waiting to send */
175 struct rpc_wait_queue pending; /* requests in flight */
176 struct rpc_wait_queue backlog; /* waiting for slot */
177 struct list_head free; /* free slots */
178 unsigned int max_reqs; /* max number of slots */
179 unsigned int min_reqs; /* min number of slots */
180 atomic_t num_reqs; /* total slots */
181 unsigned long state; /* transport state */
182 unsigned char resvport : 1; /* use a reserved port */
183 unsigned int swapper; /* we're swapping over this
184 transport */
185 unsigned int bind_index; /* bind function index */
186
187 /*
188 * Connection of transports
189 */
190 unsigned long bind_timeout,
191 reestablish_timeout;
192 unsigned int connect_cookie; /* A cookie that gets bumped
193 every time the transport
194 is reconnected */
195
196 /*
197 * Disconnection of idle transports
198 */
199 struct work_struct task_cleanup;
200 struct timer_list timer;
201 unsigned long last_used,
202 idle_timeout;
203
204 /*
205 * Send stuff
206 */
207 spinlock_t transport_lock; /* lock transport info */
208 spinlock_t reserve_lock; /* lock slot table */
209 u32 xid; /* Next XID value to use */
210 struct rpc_task * snd_task; /* Task blocked in send */
211 struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */
212 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
213 struct svc_serv *bc_serv; /* The RPC service which will */
214 /* process the callback */
215 unsigned int bc_alloc_count; /* Total number of preallocs */
216 spinlock_t bc_pa_lock; /* Protects the preallocated
217 * items */
218 struct list_head bc_pa_list; /* List of preallocated
219 * backchannel rpc_rqst's */
220 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
221 struct list_head recv;
222
223 struct {
224 unsigned long bind_count, /* total number of binds */
225 connect_count, /* total number of connects */
226 connect_start, /* connect start timestamp */
227 connect_time, /* jiffies waiting for connect */
228 sends, /* how many complete requests */
229 recvs, /* how many complete requests */
230 bad_xids, /* lookup_rqst didn't find XID */
231 max_slots; /* max rpc_slots used */
232
233 unsigned long long req_u, /* average requests on the wire */
234 bklog_u, /* backlog queue utilization */
235 sending_u, /* send q utilization */
236 pending_u; /* pend q utilization */
237 } stat;
238
239 struct net *xprt_net;
240 const char *servername;
241 const char *address_strings[RPC_DISPLAY_MAX];
242 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
243 struct dentry *debugfs; /* debugfs directory */
244 #endif
245 };
246
247 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
248 /*
249 * Backchannel flags
250 */
251 #define RPC_BC_PA_IN_USE 0x0001 /* Preallocated backchannel */
252 /* buffer in use */
253 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
254
255 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
bc_prealloc(struct rpc_rqst * req)256 static inline int bc_prealloc(struct rpc_rqst *req)
257 {
258 return test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
259 }
260 #else
bc_prealloc(struct rpc_rqst * req)261 static inline int bc_prealloc(struct rpc_rqst *req)
262 {
263 return 0;
264 }
265 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
266
267 #define XPRT_CREATE_INFINITE_SLOTS (1U)
268 #define XPRT_CREATE_NO_IDLE_TIMEOUT (1U << 1)
269
270 struct xprt_create {
271 int ident; /* XPRT_TRANSPORT identifier */
272 struct net * net;
273 struct sockaddr * srcaddr; /* optional local address */
274 struct sockaddr * dstaddr; /* remote peer address */
275 size_t addrlen;
276 const char *servername;
277 struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */
278 unsigned int flags;
279 };
280
281 struct xprt_class {
282 struct list_head list;
283 int ident; /* XPRT_TRANSPORT identifier */
284 struct rpc_xprt * (*setup)(struct xprt_create *);
285 struct module *owner;
286 char name[32];
287 };
288
289 /*
290 * Generic internal transport functions
291 */
292 struct rpc_xprt *xprt_create_transport(struct xprt_create *args);
293 void xprt_connect(struct rpc_task *task);
294 void xprt_reserve(struct rpc_task *task);
295 void xprt_retry_reserve(struct rpc_task *task);
296 int xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
297 int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
298 void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
299 void xprt_lock_and_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
300 bool xprt_prepare_transmit(struct rpc_task *task);
301 void xprt_transmit(struct rpc_task *task);
302 void xprt_end_transmit(struct rpc_task *task);
303 int xprt_adjust_timeout(struct rpc_rqst *req);
304 void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
305 void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
306 void xprt_release(struct rpc_task *task);
307 void xprt_put(struct rpc_xprt *xprt);
308 struct rpc_xprt * xprt_alloc(struct net *net, size_t size,
309 unsigned int num_prealloc,
310 unsigned int max_req);
311 void xprt_free(struct rpc_xprt *);
312
313 /**
314 * xprt_get - return a reference to an RPC transport.
315 * @xprt: pointer to the transport
316 *
317 */
xprt_get(struct rpc_xprt * xprt)318 static inline struct rpc_xprt *xprt_get(struct rpc_xprt *xprt)
319 {
320 if (atomic_inc_not_zero(&xprt->count))
321 return xprt;
322 return NULL;
323 }
324
xprt_skip_transport_header(struct rpc_xprt * xprt,__be32 * p)325 static inline __be32 *xprt_skip_transport_header(struct rpc_xprt *xprt, __be32 *p)
326 {
327 return p + xprt->tsh_size;
328 }
329
330 /*
331 * Transport switch helper functions
332 */
333 int xprt_register_transport(struct xprt_class *type);
334 int xprt_unregister_transport(struct xprt_class *type);
335 int xprt_load_transport(const char *);
336 void xprt_set_retrans_timeout_def(struct rpc_task *task);
337 void xprt_set_retrans_timeout_rtt(struct rpc_task *task);
338 void xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status);
339 void xprt_wait_for_buffer_space(struct rpc_task *task, rpc_action action);
340 void xprt_write_space(struct rpc_xprt *xprt);
341 void xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result);
342 struct rpc_rqst * xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid);
343 void xprt_complete_rqst(struct rpc_task *task, int copied);
344 void xprt_release_rqst_cong(struct rpc_task *task);
345 void xprt_disconnect_done(struct rpc_xprt *xprt);
346 void xprt_force_disconnect(struct rpc_xprt *xprt);
347 void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie);
348 int xs_swapper(struct rpc_xprt *xprt, int enable);
349
350 bool xprt_lock_connect(struct rpc_xprt *, struct rpc_task *, void *);
351 void xprt_unlock_connect(struct rpc_xprt *, void *);
352
353 /*
354 * Reserved bit positions in xprt->state
355 */
356 #define XPRT_LOCKED (0)
357 #define XPRT_CONNECTED (1)
358 #define XPRT_CONNECTING (2)
359 #define XPRT_CLOSE_WAIT (3)
360 #define XPRT_BOUND (4)
361 #define XPRT_BINDING (5)
362 #define XPRT_CLOSING (6)
363 #define XPRT_CONGESTED (9)
364
xprt_set_connected(struct rpc_xprt * xprt)365 static inline void xprt_set_connected(struct rpc_xprt *xprt)
366 {
367 set_bit(XPRT_CONNECTED, &xprt->state);
368 }
369
xprt_clear_connected(struct rpc_xprt * xprt)370 static inline void xprt_clear_connected(struct rpc_xprt *xprt)
371 {
372 clear_bit(XPRT_CONNECTED, &xprt->state);
373 }
374
xprt_connected(struct rpc_xprt * xprt)375 static inline int xprt_connected(struct rpc_xprt *xprt)
376 {
377 return test_bit(XPRT_CONNECTED, &xprt->state);
378 }
379
xprt_test_and_set_connected(struct rpc_xprt * xprt)380 static inline int xprt_test_and_set_connected(struct rpc_xprt *xprt)
381 {
382 return test_and_set_bit(XPRT_CONNECTED, &xprt->state);
383 }
384
xprt_test_and_clear_connected(struct rpc_xprt * xprt)385 static inline int xprt_test_and_clear_connected(struct rpc_xprt *xprt)
386 {
387 return test_and_clear_bit(XPRT_CONNECTED, &xprt->state);
388 }
389
xprt_clear_connecting(struct rpc_xprt * xprt)390 static inline void xprt_clear_connecting(struct rpc_xprt *xprt)
391 {
392 smp_mb__before_atomic();
393 clear_bit(XPRT_CONNECTING, &xprt->state);
394 smp_mb__after_atomic();
395 }
396
xprt_connecting(struct rpc_xprt * xprt)397 static inline int xprt_connecting(struct rpc_xprt *xprt)
398 {
399 return test_bit(XPRT_CONNECTING, &xprt->state);
400 }
401
xprt_test_and_set_connecting(struct rpc_xprt * xprt)402 static inline int xprt_test_and_set_connecting(struct rpc_xprt *xprt)
403 {
404 return test_and_set_bit(XPRT_CONNECTING, &xprt->state);
405 }
406
xprt_set_bound(struct rpc_xprt * xprt)407 static inline void xprt_set_bound(struct rpc_xprt *xprt)
408 {
409 test_and_set_bit(XPRT_BOUND, &xprt->state);
410 }
411
xprt_bound(struct rpc_xprt * xprt)412 static inline int xprt_bound(struct rpc_xprt *xprt)
413 {
414 return test_bit(XPRT_BOUND, &xprt->state);
415 }
416
xprt_clear_bound(struct rpc_xprt * xprt)417 static inline void xprt_clear_bound(struct rpc_xprt *xprt)
418 {
419 clear_bit(XPRT_BOUND, &xprt->state);
420 }
421
xprt_clear_binding(struct rpc_xprt * xprt)422 static inline void xprt_clear_binding(struct rpc_xprt *xprt)
423 {
424 smp_mb__before_atomic();
425 clear_bit(XPRT_BINDING, &xprt->state);
426 smp_mb__after_atomic();
427 }
428
xprt_test_and_set_binding(struct rpc_xprt * xprt)429 static inline int xprt_test_and_set_binding(struct rpc_xprt *xprt)
430 {
431 return test_and_set_bit(XPRT_BINDING, &xprt->state);
432 }
433
434 #endif /* __KERNEL__*/
435
436 #endif /* _LINUX_SUNRPC_XPRT_H */
437