1 /* SPDX-License-Identifier: GPL-2.0 */
3 * linux/include/linux/sunrpc/xprt.h
5 * Declarations for the RPC transport interface.
7 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
10 #ifndef _LINUX_SUNRPC_XPRT_H
11 #define _LINUX_SUNRPC_XPRT_H
13 #include <linux/uio.h>
14 #include <linux/socket.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>
24 #define RPC_MIN_SLOT_TABLE (2U)
25 #define RPC_DEF_SLOT_TABLE (16U)
26 #define RPC_MAX_SLOT_TABLE_LIMIT (65536U)
27 #define RPC_MAX_SLOT_TABLE RPC_MAX_SLOT_TABLE_LIMIT
29 #define RPC_CWNDSHIFT (8U)
30 #define RPC_CWNDSCALE (1U << RPC_CWNDSHIFT)
31 #define RPC_INITCWND RPC_CWNDSCALE
32 #define RPC_MAXCWND(xprt) ((xprt)->max_reqs << RPC_CWNDSHIFT)
33 #define RPCXPRT_CONGESTED(xprt) ((xprt)->cong >= (xprt)->cwnd)
36 * This describes a timeout strategy
39 unsigned long to_initval, /* initial timeout */
40 to_maxval, /* max timeout */
41 to_increment; /* if !exponential */
42 unsigned int to_retries; /* max # of retries */
43 unsigned char to_exponential;
46 enum rpc_display_format_t {
63 * This describes a complete RPC request
67 * This is the user-visible part
69 struct rpc_xprt * rq_xprt; /* RPC client */
70 struct xdr_buf rq_snd_buf; /* send buffer */
71 struct xdr_buf rq_rcv_buf; /* recv buffer */
74 * This is the private part
76 struct rpc_task * rq_task; /* RPC task data */
77 struct rpc_cred * rq_cred; /* Bound cred */
78 __be32 rq_xid; /* request XID */
79 int rq_cong; /* has incremented xprt->cong */
80 u32 rq_seqno; /* gss seq no. used on req. */
82 struct page **rq_enc_pages; /* scratch pages for use by
84 void (*rq_release_snd_buf)(struct rpc_rqst *); /* release rq_enc_pages */
85 struct list_head rq_list;
87 void *rq_buffer; /* Call XDR encode buffer */
89 void *rq_rbuffer; /* Reply XDR decode buffer */
91 size_t rq_xmit_bytes_sent; /* total bytes sent */
92 size_t rq_reply_bytes_recvd; /* total reply bytes */
95 struct xdr_buf rq_private_buf; /* The receive buffer
96 * used in the softirq.
98 unsigned long rq_majortimeo; /* major timeout alarm */
99 unsigned long rq_timeout; /* Current timeout value */
100 ktime_t rq_rtt; /* round-trip time */
101 unsigned int rq_retries; /* # of retries */
102 unsigned int rq_connect_cookie;
103 /* A cookie used to track the
104 state of the transport
108 * Partial send handling
110 u32 rq_bytes_sent; /* Bytes we have sent */
112 ktime_t rq_xtime; /* transmit time stamp */
115 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
116 struct list_head rq_bc_list; /* Callback service list */
117 unsigned long rq_bc_pa_state; /* Backchannel prealloc state */
118 struct list_head rq_bc_pa_list; /* Backchannel prealloc list */
119 #endif /* CONFIG_SUNRPC_BACKCHANEL */
121 #define rq_svec rq_snd_buf.head
122 #define rq_slen rq_snd_buf.len
124 struct rpc_xprt_ops {
125 void (*set_buffer_size)(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize);
126 int (*reserve_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
127 void (*release_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
128 void (*alloc_slot)(struct rpc_xprt *xprt, struct rpc_task *task);
129 void (*free_slot)(struct rpc_xprt *xprt,
130 struct rpc_rqst *req);
131 void (*rpcbind)(struct rpc_task *task);
132 void (*set_port)(struct rpc_xprt *xprt, unsigned short port);
133 void (*connect)(struct rpc_xprt *xprt, struct rpc_task *task);
134 int (*buf_alloc)(struct rpc_task *task);
135 void (*buf_free)(struct rpc_task *task);
136 int (*send_request)(struct rpc_task *task);
137 void (*set_retrans_timeout)(struct rpc_task *task);
138 void (*timer)(struct rpc_xprt *xprt, struct rpc_task *task);
139 void (*release_request)(struct rpc_task *task);
140 void (*close)(struct rpc_xprt *xprt);
141 void (*destroy)(struct rpc_xprt *xprt);
142 void (*set_connect_timeout)(struct rpc_xprt *xprt,
143 unsigned long connect_timeout,
144 unsigned long reconnect_timeout);
145 void (*print_stats)(struct rpc_xprt *xprt, struct seq_file *seq);
146 int (*enable_swap)(struct rpc_xprt *xprt);
147 void (*disable_swap)(struct rpc_xprt *xprt);
148 void (*inject_disconnect)(struct rpc_xprt *xprt);
149 int (*bc_setup)(struct rpc_xprt *xprt,
150 unsigned int min_reqs);
151 int (*bc_up)(struct svc_serv *serv, struct net *net);
152 size_t (*bc_maxpayload)(struct rpc_xprt *xprt);
153 void (*bc_free_rqst)(struct rpc_rqst *rqst);
154 void (*bc_destroy)(struct rpc_xprt *xprt,
155 unsigned int max_reqs);
159 * RPC transport identifiers
161 * To preserve compatibility with the historical use of raw IP protocol
162 * id's for transport selection, UDP and TCP identifiers are specified
163 * with the previous values. No such restriction exists for new transports,
164 * except that they may not collide with these values (17 and 6,
167 #define XPRT_TRANSPORT_BC (1 << 31)
168 enum xprt_transports {
169 XPRT_TRANSPORT_UDP = IPPROTO_UDP,
170 XPRT_TRANSPORT_TCP = IPPROTO_TCP,
171 XPRT_TRANSPORT_BC_TCP = IPPROTO_TCP | XPRT_TRANSPORT_BC,
172 XPRT_TRANSPORT_RDMA = 256,
173 XPRT_TRANSPORT_BC_RDMA = XPRT_TRANSPORT_RDMA | XPRT_TRANSPORT_BC,
174 XPRT_TRANSPORT_LOCAL = 257,
178 struct kref kref; /* Reference count */
179 const struct rpc_xprt_ops *ops; /* transport methods */
181 const struct rpc_timeout *timeout; /* timeout parms */
182 struct sockaddr_storage addr; /* server address */
183 size_t addrlen; /* size of server address */
184 int prot; /* IP protocol */
186 unsigned long cong; /* current congestion */
187 unsigned long cwnd; /* congestion window */
189 size_t max_payload; /* largest RPC payload size,
191 unsigned int tsh_size; /* size of transport specific
194 struct rpc_wait_queue binding; /* requests waiting on rpcbind */
195 struct rpc_wait_queue sending; /* requests waiting to send */
196 struct rpc_wait_queue pending; /* requests in flight */
197 struct rpc_wait_queue backlog; /* waiting for slot */
198 struct list_head free; /* free slots */
199 unsigned int max_reqs; /* max number of slots */
200 unsigned int min_reqs; /* min number of slots */
201 unsigned int num_reqs; /* total slots */
202 unsigned long state; /* transport state */
203 unsigned char resvport : 1; /* use a reserved port */
204 atomic_t swapper; /* we're swapping over this
206 unsigned int bind_index; /* bind function index */
211 struct list_head xprt_switch;
214 * Connection of transports
216 unsigned long bind_timeout,
218 unsigned int connect_cookie; /* A cookie that gets bumped
219 every time the transport
223 * Disconnection of idle transports
225 struct work_struct task_cleanup;
226 struct timer_list timer;
227 unsigned long last_used,
230 max_reconnect_timeout;
235 spinlock_t transport_lock; /* lock transport info */
236 spinlock_t reserve_lock; /* lock slot table */
237 spinlock_t recv_lock; /* lock receive list */
238 u32 xid; /* Next XID value to use */
239 struct rpc_task * snd_task; /* Task blocked in send */
240 struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */
241 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
242 struct svc_serv *bc_serv; /* The RPC service which will */
243 /* process the callback */
244 int bc_alloc_count; /* Total number of preallocs */
245 atomic_t bc_free_slots;
246 spinlock_t bc_pa_lock; /* Protects the preallocated
248 struct list_head bc_pa_list; /* List of preallocated
249 * backchannel rpc_rqst's */
250 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
251 struct list_head recv;
254 unsigned long bind_count, /* total number of binds */
255 connect_count, /* total number of connects */
256 connect_start, /* connect start timestamp */
257 connect_time, /* jiffies waiting for connect */
258 sends, /* how many complete requests */
259 recvs, /* how many complete requests */
260 bad_xids, /* lookup_rqst didn't find XID */
261 max_slots; /* max rpc_slots used */
263 unsigned long long req_u, /* average requests on the wire */
264 bklog_u, /* backlog queue utilization */
265 sending_u, /* send q utilization */
266 pending_u; /* pend q utilization */
269 struct net *xprt_net;
270 const char *servername;
271 const char *address_strings[RPC_DISPLAY_MAX];
272 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
273 struct dentry *debugfs; /* debugfs directory */
274 atomic_t inject_disconnect;
279 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
283 #define RPC_BC_PA_IN_USE 0x0001 /* Preallocated backchannel */
285 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
287 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
288 static inline int bc_prealloc(struct rpc_rqst *req)
290 return test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
293 static inline int bc_prealloc(struct rpc_rqst *req)
297 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
299 #define XPRT_CREATE_INFINITE_SLOTS (1U)
300 #define XPRT_CREATE_NO_IDLE_TIMEOUT (1U << 1)
303 int ident; /* XPRT_TRANSPORT identifier */
305 struct sockaddr * srcaddr; /* optional local address */
306 struct sockaddr * dstaddr; /* remote peer address */
308 const char *servername;
309 struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */
310 struct rpc_xprt_switch *bc_xps;
315 struct list_head list;
316 int ident; /* XPRT_TRANSPORT identifier */
317 struct rpc_xprt * (*setup)(struct xprt_create *);
318 struct module *owner;
320 const char * netid[];
324 * Generic internal transport functions
326 struct rpc_xprt *xprt_create_transport(struct xprt_create *args);
327 void xprt_connect(struct rpc_task *task);
328 void xprt_reserve(struct rpc_task *task);
329 void xprt_retry_reserve(struct rpc_task *task);
330 int xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
331 int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
332 void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
333 void xprt_free_slot(struct rpc_xprt *xprt,
334 struct rpc_rqst *req);
335 void xprt_lock_and_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
336 bool xprt_prepare_transmit(struct rpc_task *task);
337 void xprt_transmit(struct rpc_task *task);
338 void xprt_end_transmit(struct rpc_task *task);
339 int xprt_adjust_timeout(struct rpc_rqst *req);
340 void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
341 void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
342 void xprt_release(struct rpc_task *task);
343 struct rpc_xprt * xprt_get(struct rpc_xprt *xprt);
344 void xprt_put(struct rpc_xprt *xprt);
345 struct rpc_xprt * xprt_alloc(struct net *net, size_t size,
346 unsigned int num_prealloc,
347 unsigned int max_req);
348 void xprt_free(struct rpc_xprt *);
350 static inline __be32 *xprt_skip_transport_header(struct rpc_xprt *xprt, __be32 *p)
352 return p + xprt->tsh_size;
356 xprt_enable_swap(struct rpc_xprt *xprt)
358 return xprt->ops->enable_swap(xprt);
362 xprt_disable_swap(struct rpc_xprt *xprt)
364 xprt->ops->disable_swap(xprt);
368 * Transport switch helper functions
370 int xprt_register_transport(struct xprt_class *type);
371 int xprt_unregister_transport(struct xprt_class *type);
372 int xprt_load_transport(const char *);
373 void xprt_set_retrans_timeout_def(struct rpc_task *task);
374 void xprt_set_retrans_timeout_rtt(struct rpc_task *task);
375 void xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status);
376 void xprt_wait_for_buffer_space(struct rpc_task *task, rpc_action action);
377 void xprt_write_space(struct rpc_xprt *xprt);
378 void xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result);
379 struct rpc_rqst * xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid);
380 void xprt_update_rtt(struct rpc_task *task);
381 void xprt_complete_rqst(struct rpc_task *task, int copied);
382 void xprt_pin_rqst(struct rpc_rqst *req);
383 void xprt_unpin_rqst(struct rpc_rqst *req);
384 void xprt_release_rqst_cong(struct rpc_task *task);
385 void xprt_disconnect_done(struct rpc_xprt *xprt);
386 void xprt_force_disconnect(struct rpc_xprt *xprt);
387 void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie);
389 bool xprt_lock_connect(struct rpc_xprt *, struct rpc_task *, void *);
390 void xprt_unlock_connect(struct rpc_xprt *, void *);
393 * Reserved bit positions in xprt->state
395 #define XPRT_LOCKED (0)
396 #define XPRT_CONNECTED (1)
397 #define XPRT_CONNECTING (2)
398 #define XPRT_CLOSE_WAIT (3)
399 #define XPRT_BOUND (4)
400 #define XPRT_BINDING (5)
401 #define XPRT_CLOSING (6)
402 #define XPRT_CONGESTED (9)
404 static inline void xprt_set_connected(struct rpc_xprt *xprt)
406 set_bit(XPRT_CONNECTED, &xprt->state);
409 static inline void xprt_clear_connected(struct rpc_xprt *xprt)
411 clear_bit(XPRT_CONNECTED, &xprt->state);
414 static inline int xprt_connected(struct rpc_xprt *xprt)
416 return test_bit(XPRT_CONNECTED, &xprt->state);
419 static inline int xprt_test_and_set_connected(struct rpc_xprt *xprt)
421 return test_and_set_bit(XPRT_CONNECTED, &xprt->state);
424 static inline int xprt_test_and_clear_connected(struct rpc_xprt *xprt)
426 return test_and_clear_bit(XPRT_CONNECTED, &xprt->state);
429 static inline void xprt_clear_connecting(struct rpc_xprt *xprt)
431 smp_mb__before_atomic();
432 clear_bit(XPRT_CONNECTING, &xprt->state);
433 smp_mb__after_atomic();
436 static inline int xprt_connecting(struct rpc_xprt *xprt)
438 return test_bit(XPRT_CONNECTING, &xprt->state);
441 static inline int xprt_test_and_set_connecting(struct rpc_xprt *xprt)
443 return test_and_set_bit(XPRT_CONNECTING, &xprt->state);
446 static inline int xprt_close_wait(struct rpc_xprt *xprt)
448 return test_bit(XPRT_CLOSE_WAIT, &xprt->state);
451 static inline void xprt_set_bound(struct rpc_xprt *xprt)
453 test_and_set_bit(XPRT_BOUND, &xprt->state);
456 static inline int xprt_bound(struct rpc_xprt *xprt)
458 return test_bit(XPRT_BOUND, &xprt->state);
461 static inline void xprt_clear_bound(struct rpc_xprt *xprt)
463 clear_bit(XPRT_BOUND, &xprt->state);
466 static inline void xprt_clear_binding(struct rpc_xprt *xprt)
468 smp_mb__before_atomic();
469 clear_bit(XPRT_BINDING, &xprt->state);
470 smp_mb__after_atomic();
473 static inline int xprt_test_and_set_binding(struct rpc_xprt *xprt)
475 return test_and_set_bit(XPRT_BINDING, &xprt->state);
478 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
479 extern unsigned int rpc_inject_disconnect;
480 static inline void xprt_inject_disconnect(struct rpc_xprt *xprt)
482 if (!rpc_inject_disconnect)
484 if (atomic_dec_return(&xprt->inject_disconnect))
486 atomic_set(&xprt->inject_disconnect, rpc_inject_disconnect);
487 xprt->ops->inject_disconnect(xprt);
490 static inline void xprt_inject_disconnect(struct rpc_xprt *xprt)
495 #endif /* __KERNEL__*/
497 #endif /* _LINUX_SUNRPC_XPRT_H */