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xprt.h
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1 /*
2  * linux/include/linux/sunrpc/xprt.h
3  *
4  * Declarations for the RPC transport interface.
5  *
6  * Copyright (C) 1995, 1996 Olaf Kirch <[email protected]>
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 /*
28  * This describes a timeout strategy
29  */
30 struct rpc_timeout {
31  unsigned long to_initval, /* initial timeout */
32  to_maxval, /* max timeout */
33  to_increment; /* if !exponential */
34  unsigned int to_retries; /* max # of retries */
35  unsigned char to_exponential;
36 };
37 
38 enum rpc_display_format_t {
39  RPC_DISPLAY_ADDR = 0,
40  RPC_DISPLAY_PORT,
41  RPC_DISPLAY_PROTO,
42  RPC_DISPLAY_HEX_ADDR,
43  RPC_DISPLAY_HEX_PORT,
44  RPC_DISPLAY_NETID,
45  RPC_DISPLAY_MAX,
46 };
47 
48 struct rpc_task;
49 struct rpc_xprt;
50 struct seq_file;
51 
52 /*
53  * This describes a complete RPC request
54  */
55 struct rpc_rqst {
56  /*
57  * This is the user-visible part
58  */
59  struct rpc_xprt * rq_xprt; /* RPC client */
60  struct xdr_buf rq_snd_buf; /* send buffer */
61  struct xdr_buf rq_rcv_buf; /* recv buffer */
62 
63  /*
64  * This is the private part
65  */
66  struct rpc_task * rq_task; /* RPC task data */
67  struct rpc_cred * rq_cred; /* Bound cred */
68  __be32 rq_xid; /* request XID */
69  int rq_cong; /* has incremented xprt->cong */
70  u32 rq_seqno; /* gss seq no. used on req. */
71  int rq_enc_pages_num;
72  struct page **rq_enc_pages; /* scratch pages for use by
73  gss privacy code */
74  void (*rq_release_snd_buf)(struct rpc_rqst *); /* release rq_enc_pages */
75  struct list_head rq_list;
76 
77  __u32 * rq_buffer; /* XDR encode buffer */
78  size_t rq_callsize,
79  rq_rcvsize;
80  size_t rq_xmit_bytes_sent; /* total bytes sent */
81  size_t rq_reply_bytes_recvd; /* total reply bytes */
82  /* received */
83 
84  struct xdr_buf rq_private_buf; /* The receive buffer
85  * used in the softirq.
86  */
87  unsigned long rq_majortimeo; /* major timeout alarm */
88  unsigned long rq_timeout; /* Current timeout value */
89  ktime_t rq_rtt; /* round-trip time */
90  unsigned int rq_retries; /* # of retries */
91  unsigned int rq_connect_cookie;
92  /* A cookie used to track the
93  state of the transport
94  connection */
95 
96  /*
97  * Partial send handling
98  */
99  u32 rq_bytes_sent; /* Bytes we have sent */
100 
101  ktime_t rq_xtime; /* transmit time stamp */
102  int rq_ntrans;
103 
104 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
105  struct list_head rq_bc_list; /* Callback service list */
106  unsigned long rq_bc_pa_state; /* Backchannel prealloc state */
107  struct list_head rq_bc_pa_list; /* Backchannel prealloc list */
108 #endif /* CONFIG_SUNRPC_BACKCHANEL */
109 };
110 #define rq_svec rq_snd_buf.head
111 #define rq_slen rq_snd_buf.len
112 
113 struct rpc_xprt_ops {
114  void (*set_buffer_size)(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize);
115  int (*reserve_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
116  void (*release_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
117  void (*alloc_slot)(struct rpc_xprt *xprt, struct rpc_task *task);
118  void (*rpcbind)(struct rpc_task *task);
119  void (*set_port)(struct rpc_xprt *xprt, unsigned short port);
120  void (*connect)(struct rpc_task *task);
121  void * (*buf_alloc)(struct rpc_task *task, size_t size);
122  void (*buf_free)(void *buffer);
123  int (*send_request)(struct rpc_task *task);
124  void (*set_retrans_timeout)(struct rpc_task *task);
125  void (*timer)(struct rpc_task *task);
126  void (*release_request)(struct rpc_task *task);
127  void (*close)(struct rpc_xprt *xprt);
128  void (*destroy)(struct rpc_xprt *xprt);
129  void (*print_stats)(struct rpc_xprt *xprt, struct seq_file *seq);
130 };
131 
132 /*
133  * RPC transport identifiers
134  *
135  * To preserve compatibility with the historical use of raw IP protocol
136  * id's for transport selection, UDP and TCP identifiers are specified
137  * with the previous values. No such restriction exists for new transports,
138  * except that they may not collide with these values (17 and 6,
139  * respectively).
140  */
141 #define XPRT_TRANSPORT_BC (1 << 31)
142 enum xprt_transports {
143  XPRT_TRANSPORT_UDP = IPPROTO_UDP,
144  XPRT_TRANSPORT_TCP = IPPROTO_TCP,
145  XPRT_TRANSPORT_BC_TCP = IPPROTO_TCP | XPRT_TRANSPORT_BC,
146  XPRT_TRANSPORT_RDMA = 256,
147  XPRT_TRANSPORT_LOCAL = 257,
148 };
149 
150 struct rpc_xprt {
151  atomic_t count; /* Reference count */
152  struct rpc_xprt_ops * ops; /* transport methods */
153 
154  const struct rpc_timeout *timeout; /* timeout parms */
155  struct sockaddr_storage addr; /* server address */
156  size_t addrlen; /* size of server address */
157  int prot; /* IP protocol */
158 
159  unsigned long cong; /* current congestion */
160  unsigned long cwnd; /* congestion window */
161 
162  size_t max_payload; /* largest RPC payload size,
163  in bytes */
164  unsigned int tsh_size; /* size of transport specific
165  header */
166 
167  struct rpc_wait_queue binding; /* requests waiting on rpcbind */
168  struct rpc_wait_queue sending; /* requests waiting to send */
169  struct rpc_wait_queue pending; /* requests in flight */
170  struct rpc_wait_queue backlog; /* waiting for slot */
171  struct list_head free; /* free slots */
172  unsigned int max_reqs; /* max number of slots */
173  unsigned int min_reqs; /* min number of slots */
174  atomic_t num_reqs; /* total slots */
175  unsigned long state; /* transport state */
176  unsigned char resvport : 1; /* use a reserved port */
177  unsigned int swapper; /* we're swapping over this
178  transport */
179  unsigned int bind_index; /* bind function index */
180 
181  /*
182  * Connection of transports
183  */
184  unsigned long bind_timeout,
185  reestablish_timeout;
186  unsigned int connect_cookie; /* A cookie that gets bumped
187  every time the transport
188  is reconnected */
189 
190  /*
191  * Disconnection of idle transports
192  */
193  struct work_struct task_cleanup;
194  struct timer_list timer;
195  unsigned long last_used,
196  idle_timeout;
197 
198  /*
199  * Send stuff
200  */
201  spinlock_t transport_lock; /* lock transport info */
202  spinlock_t reserve_lock; /* lock slot table */
203  u32 xid; /* Next XID value to use */
204  struct rpc_task * snd_task; /* Task blocked in send */
205  struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */
206 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
207  struct svc_serv *bc_serv; /* The RPC service which will */
208  /* process the callback */
209  unsigned int bc_alloc_count; /* Total number of preallocs */
210  spinlock_t bc_pa_lock; /* Protects the preallocated
211  * items */
212  struct list_head bc_pa_list; /* List of preallocated
213  * backchannel rpc_rqst's */
214 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
215  struct list_head recv;
216 
217  struct {
218  unsigned long bind_count, /* total number of binds */
219  connect_count, /* total number of connects */
220  connect_start, /* connect start timestamp */
221  connect_time, /* jiffies waiting for connect */
222  sends, /* how many complete requests */
223  recvs, /* how many complete requests */
224  bad_xids, /* lookup_rqst didn't find XID */
225  max_slots; /* max rpc_slots used */
226 
227  unsigned long long req_u, /* average requests on the wire */
228  bklog_u, /* backlog queue utilization */
229  sending_u, /* send q utilization */
230  pending_u; /* pend q utilization */
231  } stat;
232 
233  struct net *xprt_net;
234  const char *servername;
235  const char *address_strings[RPC_DISPLAY_MAX];
236 };
237 
238 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
239 /*
240  * Backchannel flags
241  */
242 #define RPC_BC_PA_IN_USE 0x0001 /* Preallocated backchannel */
243  /* buffer in use */
244 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
245 
246 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
247 static inline int bc_prealloc(struct rpc_rqst *req)
248 {
249  return test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
250 }
251 #else
252 static inline int bc_prealloc(struct rpc_rqst *req)
253 {
254  return 0;
255 }
256 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
257 
258 struct xprt_create {
259  int ident; /* XPRT_TRANSPORT identifier */
260  struct net * net;
261  struct sockaddr * srcaddr; /* optional local address */
262  struct sockaddr * dstaddr; /* remote peer address */
263  size_t addrlen;
264  const char *servername;
265  struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */
266 };
267 
268 struct xprt_class {
269  struct list_head list;
270  int ident; /* XPRT_TRANSPORT identifier */
271  struct rpc_xprt * (*setup)(struct xprt_create *);
272  struct module *owner;
273  char name[32];
274 };
275 
276 /*
277  * Generic internal transport functions
278  */
279 struct rpc_xprt *xprt_create_transport(struct xprt_create *args);
280 void xprt_connect(struct rpc_task *task);
281 void xprt_reserve(struct rpc_task *task);
282 int xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
283 int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
284 void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
285 void xprt_lock_and_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
286 int xprt_prepare_transmit(struct rpc_task *task);
287 void xprt_transmit(struct rpc_task *task);
288 void xprt_end_transmit(struct rpc_task *task);
289 int xprt_adjust_timeout(struct rpc_rqst *req);
290 void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
291 void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
292 void xprt_release(struct rpc_task *task);
293 struct rpc_xprt * xprt_get(struct rpc_xprt *xprt);
294 void xprt_put(struct rpc_xprt *xprt);
295 struct rpc_xprt * xprt_alloc(struct net *net, size_t size,
296  unsigned int num_prealloc,
297  unsigned int max_req);
298 void xprt_free(struct rpc_xprt *);
299 
300 static inline __be32 *xprt_skip_transport_header(struct rpc_xprt *xprt, __be32 *p)
301 {
302  return p + xprt->tsh_size;
303 }
304 
305 /*
306  * Transport switch helper functions
307  */
308 int xprt_register_transport(struct xprt_class *type);
309 int xprt_unregister_transport(struct xprt_class *type);
310 int xprt_load_transport(const char *);
311 void xprt_set_retrans_timeout_def(struct rpc_task *task);
312 void xprt_set_retrans_timeout_rtt(struct rpc_task *task);
313 void xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status);
314 void xprt_wait_for_buffer_space(struct rpc_task *task, rpc_action action);
315 void xprt_write_space(struct rpc_xprt *xprt);
316 void xprt_adjust_cwnd(struct rpc_task *task, int result);
317 struct rpc_rqst * xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid);
318 void xprt_complete_rqst(struct rpc_task *task, int copied);
319 void xprt_release_rqst_cong(struct rpc_task *task);
320 void xprt_disconnect_done(struct rpc_xprt *xprt);
321 void xprt_force_disconnect(struct rpc_xprt *xprt);
322 void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie);
323 int xs_swapper(struct rpc_xprt *xprt, int enable);
324 
325 /*
326  * Reserved bit positions in xprt->state
327  */
328 #define XPRT_LOCKED (0)
329 #define XPRT_CONNECTED (1)
330 #define XPRT_CONNECTING (2)
331 #define XPRT_CLOSE_WAIT (3)
332 #define XPRT_BOUND (4)
333 #define XPRT_BINDING (5)
334 #define XPRT_CLOSING (6)
335 #define XPRT_CONNECTION_ABORT (7)
336 #define XPRT_CONNECTION_CLOSE (8)
337 
338 static inline void xprt_set_connected(struct rpc_xprt *xprt)
339 {
340  set_bit(XPRT_CONNECTED, &xprt->state);
341 }
342 
343 static inline void xprt_clear_connected(struct rpc_xprt *xprt)
344 {
345  clear_bit(XPRT_CONNECTED, &xprt->state);
346 }
347 
348 static inline int xprt_connected(struct rpc_xprt *xprt)
349 {
350  return test_bit(XPRT_CONNECTED, &xprt->state);
351 }
352 
353 static inline int xprt_test_and_set_connected(struct rpc_xprt *xprt)
354 {
355  return test_and_set_bit(XPRT_CONNECTED, &xprt->state);
356 }
357 
358 static inline int xprt_test_and_clear_connected(struct rpc_xprt *xprt)
359 {
360  return test_and_clear_bit(XPRT_CONNECTED, &xprt->state);
361 }
362 
363 static inline void xprt_clear_connecting(struct rpc_xprt *xprt)
364 {
365  smp_mb__before_clear_bit();
366  clear_bit(XPRT_CONNECTING, &xprt->state);
367  smp_mb__after_clear_bit();
368 }
369 
370 static inline int xprt_connecting(struct rpc_xprt *xprt)
371 {
372  return test_bit(XPRT_CONNECTING, &xprt->state);
373 }
374 
375 static inline int xprt_test_and_set_connecting(struct rpc_xprt *xprt)
376 {
377  return test_and_set_bit(XPRT_CONNECTING, &xprt->state);
378 }
379 
380 static inline void xprt_set_bound(struct rpc_xprt *xprt)
381 {
382  test_and_set_bit(XPRT_BOUND, &xprt->state);
383 }
384 
385 static inline int xprt_bound(struct rpc_xprt *xprt)
386 {
387  return test_bit(XPRT_BOUND, &xprt->state);
388 }
389 
390 static inline void xprt_clear_bound(struct rpc_xprt *xprt)
391 {
392  clear_bit(XPRT_BOUND, &xprt->state);
393 }
394 
395 static inline void xprt_clear_binding(struct rpc_xprt *xprt)
396 {
397  smp_mb__before_clear_bit();
398  clear_bit(XPRT_BINDING, &xprt->state);
399  smp_mb__after_clear_bit();
400 }
401 
402 static inline int xprt_test_and_set_binding(struct rpc_xprt *xprt)
403 {
404  return test_and_set_bit(XPRT_BINDING, &xprt->state);
405 }
406 
407 #endif /* __KERNEL__*/
408 
409 #endif /* _LINUX_SUNRPC_XPRT_H */
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