2 * linux/include/linux/sunrpc/xprt.h
4 * Declarations for the RPC transport interface.
6 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
9 #ifndef _LINUX_SUNRPC_XPRT_H
10 #define _LINUX_SUNRPC_XPRT_H
12 #include <linux/uio.h>
13 #include <linux/socket.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>
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
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)
34 * This describes a timeout strategy
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;
44 enum rpc_display_format_t {
59 * This describes a complete RPC request
63 * This is the user-visible part
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 */
70 * This is the private part
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. */
78 struct page **rq_enc_pages; /* scratch pages for use by
80 void (*rq_release_snd_buf)(struct rpc_rqst *); /* release rq_enc_pages */
81 struct list_head rq_list;
83 __u32 * rq_buffer; /* XDR encode buffer */
86 size_t rq_xmit_bytes_sent; /* total bytes sent */
87 size_t rq_reply_bytes_recvd; /* total reply bytes */
90 struct xdr_buf rq_private_buf; /* The receive buffer
91 * used in the softirq.
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
103 * Partial send handling
105 u32 rq_bytes_sent; /* Bytes we have sent */
107 ktime_t rq_xtime; /* transmit time stamp */
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 */
116 #define rq_svec rq_snd_buf.head
117 #define rq_slen rq_snd_buf.len
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 int (*enable_swap)(struct rpc_xprt *xprt);
137 void (*disable_swap)(struct rpc_xprt *xprt);
138 void (*inject_disconnect)(struct rpc_xprt *xprt);
142 * RPC transport identifiers
144 * To preserve compatibility with the historical use of raw IP protocol
145 * id's for transport selection, UDP and TCP identifiers are specified
146 * with the previous values. No such restriction exists for new transports,
147 * except that they may not collide with these values (17 and 6,
150 #define XPRT_TRANSPORT_BC (1 << 31)
151 enum xprt_transports {
152 XPRT_TRANSPORT_UDP = IPPROTO_UDP,
153 XPRT_TRANSPORT_TCP = IPPROTO_TCP,
154 XPRT_TRANSPORT_BC_TCP = IPPROTO_TCP | XPRT_TRANSPORT_BC,
155 XPRT_TRANSPORT_RDMA = 256,
156 XPRT_TRANSPORT_LOCAL = 257,
160 atomic_t count; /* Reference count */
161 struct rpc_xprt_ops * ops; /* transport methods */
163 const struct rpc_timeout *timeout; /* timeout parms */
164 struct sockaddr_storage addr; /* server address */
165 size_t addrlen; /* size of server address */
166 int prot; /* IP protocol */
168 unsigned long cong; /* current congestion */
169 unsigned long cwnd; /* congestion window */
171 size_t max_payload; /* largest RPC payload size,
173 unsigned int tsh_size; /* size of transport specific
176 struct rpc_wait_queue binding; /* requests waiting on rpcbind */
177 struct rpc_wait_queue sending; /* requests waiting to send */
178 struct rpc_wait_queue pending; /* requests in flight */
179 struct rpc_wait_queue backlog; /* waiting for slot */
180 struct list_head free; /* free slots */
181 unsigned int max_reqs; /* max number of slots */
182 unsigned int min_reqs; /* min number of slots */
183 atomic_t num_reqs; /* total slots */
184 unsigned long state; /* transport state */
185 unsigned char resvport : 1; /* use a reserved port */
186 atomic_t swapper; /* we're swapping over this
188 unsigned int bind_index; /* bind function index */
191 * Connection of transports
193 unsigned long bind_timeout,
195 unsigned int connect_cookie; /* A cookie that gets bumped
196 every time the transport
200 * Disconnection of idle transports
202 struct work_struct task_cleanup;
203 struct timer_list timer;
204 unsigned long last_used,
210 spinlock_t transport_lock; /* lock transport info */
211 spinlock_t reserve_lock; /* lock slot table */
212 u32 xid; /* Next XID value to use */
213 struct rpc_task * snd_task; /* Task blocked in send */
214 struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */
215 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
216 struct svc_serv *bc_serv; /* The RPC service which will */
217 /* process the callback */
218 int bc_alloc_count; /* Total number of preallocs */
219 atomic_t bc_free_slots;
220 spinlock_t bc_pa_lock; /* Protects the preallocated
222 struct list_head bc_pa_list; /* List of preallocated
223 * backchannel rpc_rqst's */
224 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
225 struct list_head recv;
228 unsigned long bind_count, /* total number of binds */
229 connect_count, /* total number of connects */
230 connect_start, /* connect start timestamp */
231 connect_time, /* jiffies waiting for connect */
232 sends, /* how many complete requests */
233 recvs, /* how many complete requests */
234 bad_xids, /* lookup_rqst didn't find XID */
235 max_slots; /* max rpc_slots used */
237 unsigned long long req_u, /* average requests on the wire */
238 bklog_u, /* backlog queue utilization */
239 sending_u, /* send q utilization */
240 pending_u; /* pend q utilization */
243 struct net *xprt_net;
244 const char *servername;
245 const char *address_strings[RPC_DISPLAY_MAX];
246 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
247 struct dentry *debugfs; /* debugfs directory */
248 atomic_t inject_disconnect;
252 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
256 #define RPC_BC_PA_IN_USE 0x0001 /* Preallocated backchannel */
258 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
260 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
261 static inline int bc_prealloc(struct rpc_rqst *req)
263 return test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
266 static inline int bc_prealloc(struct rpc_rqst *req)
270 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
272 #define XPRT_CREATE_INFINITE_SLOTS (1U)
273 #define XPRT_CREATE_NO_IDLE_TIMEOUT (1U << 1)
276 int ident; /* XPRT_TRANSPORT identifier */
278 struct sockaddr * srcaddr; /* optional local address */
279 struct sockaddr * dstaddr; /* remote peer address */
281 const char *servername;
282 struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */
287 struct list_head list;
288 int ident; /* XPRT_TRANSPORT identifier */
289 struct rpc_xprt * (*setup)(struct xprt_create *);
290 struct module *owner;
295 * Generic internal transport functions
297 struct rpc_xprt *xprt_create_transport(struct xprt_create *args);
298 void xprt_connect(struct rpc_task *task);
299 void xprt_reserve(struct rpc_task *task);
300 void xprt_retry_reserve(struct rpc_task *task);
301 int xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
302 int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
303 void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
304 void xprt_lock_and_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
305 bool xprt_prepare_transmit(struct rpc_task *task);
306 void xprt_transmit(struct rpc_task *task);
307 void xprt_end_transmit(struct rpc_task *task);
308 int xprt_adjust_timeout(struct rpc_rqst *req);
309 void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
310 void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
311 void xprt_release(struct rpc_task *task);
312 void xprt_put(struct rpc_xprt *xprt);
313 struct rpc_xprt * xprt_alloc(struct net *net, size_t size,
314 unsigned int num_prealloc,
315 unsigned int max_req);
316 void xprt_free(struct rpc_xprt *);
319 * xprt_get - return a reference to an RPC transport.
320 * @xprt: pointer to the transport
323 static inline struct rpc_xprt *xprt_get(struct rpc_xprt *xprt)
325 if (atomic_inc_not_zero(&xprt->count))
330 static inline __be32 *xprt_skip_transport_header(struct rpc_xprt *xprt, __be32 *p)
332 return p + xprt->tsh_size;
336 xprt_enable_swap(struct rpc_xprt *xprt)
338 return xprt->ops->enable_swap(xprt);
342 xprt_disable_swap(struct rpc_xprt *xprt)
344 xprt->ops->disable_swap(xprt);
348 * Transport switch helper functions
350 int xprt_register_transport(struct xprt_class *type);
351 int xprt_unregister_transport(struct xprt_class *type);
352 int xprt_load_transport(const char *);
353 void xprt_set_retrans_timeout_def(struct rpc_task *task);
354 void xprt_set_retrans_timeout_rtt(struct rpc_task *task);
355 void xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status);
356 void xprt_wait_for_buffer_space(struct rpc_task *task, rpc_action action);
357 void xprt_write_space(struct rpc_xprt *xprt);
358 void xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result);
359 struct rpc_rqst * xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid);
360 void xprt_complete_rqst(struct rpc_task *task, int copied);
361 void xprt_release_rqst_cong(struct rpc_task *task);
362 void xprt_disconnect_done(struct rpc_xprt *xprt);
363 void xprt_force_disconnect(struct rpc_xprt *xprt);
364 void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie);
366 bool xprt_lock_connect(struct rpc_xprt *, struct rpc_task *, void *);
367 void xprt_unlock_connect(struct rpc_xprt *, void *);
370 * Reserved bit positions in xprt->state
372 #define XPRT_LOCKED (0)
373 #define XPRT_CONNECTED (1)
374 #define XPRT_CONNECTING (2)
375 #define XPRT_CLOSE_WAIT (3)
376 #define XPRT_BOUND (4)
377 #define XPRT_BINDING (5)
378 #define XPRT_CLOSING (6)
379 #define XPRT_CONGESTED (9)
381 static inline void xprt_set_connected(struct rpc_xprt *xprt)
383 set_bit(XPRT_CONNECTED, &xprt->state);
386 static inline void xprt_clear_connected(struct rpc_xprt *xprt)
388 clear_bit(XPRT_CONNECTED, &xprt->state);
391 static inline int xprt_connected(struct rpc_xprt *xprt)
393 return test_bit(XPRT_CONNECTED, &xprt->state);
396 static inline int xprt_test_and_set_connected(struct rpc_xprt *xprt)
398 return test_and_set_bit(XPRT_CONNECTED, &xprt->state);
401 static inline int xprt_test_and_clear_connected(struct rpc_xprt *xprt)
403 return test_and_clear_bit(XPRT_CONNECTED, &xprt->state);
406 static inline void xprt_clear_connecting(struct rpc_xprt *xprt)
408 smp_mb__before_atomic();
409 clear_bit(XPRT_CONNECTING, &xprt->state);
410 smp_mb__after_atomic();
413 static inline int xprt_connecting(struct rpc_xprt *xprt)
415 return test_bit(XPRT_CONNECTING, &xprt->state);
418 static inline int xprt_test_and_set_connecting(struct rpc_xprt *xprt)
420 return test_and_set_bit(XPRT_CONNECTING, &xprt->state);
423 static inline void xprt_set_bound(struct rpc_xprt *xprt)
425 test_and_set_bit(XPRT_BOUND, &xprt->state);
428 static inline int xprt_bound(struct rpc_xprt *xprt)
430 return test_bit(XPRT_BOUND, &xprt->state);
433 static inline void xprt_clear_bound(struct rpc_xprt *xprt)
435 clear_bit(XPRT_BOUND, &xprt->state);
438 static inline void xprt_clear_binding(struct rpc_xprt *xprt)
440 smp_mb__before_atomic();
441 clear_bit(XPRT_BINDING, &xprt->state);
442 smp_mb__after_atomic();
445 static inline int xprt_test_and_set_binding(struct rpc_xprt *xprt)
447 return test_and_set_bit(XPRT_BINDING, &xprt->state);
450 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
451 extern unsigned int rpc_inject_disconnect;
452 static inline void xprt_inject_disconnect(struct rpc_xprt *xprt)
454 if (!rpc_inject_disconnect)
456 if (atomic_dec_return(&xprt->inject_disconnect))
458 atomic_set(&xprt->inject_disconnect, rpc_inject_disconnect);
459 xprt->ops->inject_disconnect(xprt);
462 static inline void xprt_inject_disconnect(struct rpc_xprt *xprt)
467 #endif /* __KERNEL__*/
469 #endif /* _LINUX_SUNRPC_XPRT_H */