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/kref.h>
17 #include <linux/sunrpc/sched.h>
18 #include <linux/sunrpc/xdr.h>
19 #include <linux/sunrpc/msg_prot.h>
23 #define RPC_MIN_SLOT_TABLE (2U)
24 #define RPC_DEF_SLOT_TABLE (16U)
25 #define RPC_MAX_SLOT_TABLE_LIMIT (65536U)
26 #define RPC_MAX_SLOT_TABLE RPC_MAX_SLOT_TABLE_LIMIT
28 #define RPC_CWNDSHIFT (8U)
29 #define RPC_CWNDSCALE (1U << RPC_CWNDSHIFT)
30 #define RPC_INITCWND RPC_CWNDSCALE
31 #define RPC_MAXCWND(xprt) ((xprt)->max_reqs << RPC_CWNDSHIFT)
32 #define RPCXPRT_CONGESTED(xprt) ((xprt)->cong >= (xprt)->cwnd)
35 * This describes a timeout strategy
38 unsigned long to_initval, /* initial timeout */
39 to_maxval, /* max timeout */
40 to_increment; /* if !exponential */
41 unsigned int to_retries; /* max # of retries */
42 unsigned char to_exponential;
45 enum rpc_display_format_t {
62 * This describes a complete RPC request
66 * This is the user-visible part
68 struct rpc_xprt * rq_xprt; /* RPC client */
69 struct xdr_buf rq_snd_buf; /* send buffer */
70 struct xdr_buf rq_rcv_buf; /* recv buffer */
73 * This is the private part
75 struct rpc_task * rq_task; /* RPC task data */
76 struct rpc_cred * rq_cred; /* Bound cred */
77 __be32 rq_xid; /* request XID */
78 int rq_cong; /* has incremented xprt->cong */
79 u32 rq_seqno; /* gss seq no. used on req. */
81 struct page **rq_enc_pages; /* scratch pages for use by
83 void (*rq_release_snd_buf)(struct rpc_rqst *); /* release rq_enc_pages */
84 struct list_head rq_list;
86 __u32 * rq_buffer; /* XDR encode buffer */
89 size_t rq_xmit_bytes_sent; /* total bytes sent */
90 size_t rq_reply_bytes_recvd; /* total reply bytes */
93 struct xdr_buf rq_private_buf; /* The receive buffer
94 * used in the softirq.
96 unsigned long rq_majortimeo; /* major timeout alarm */
97 unsigned long rq_timeout; /* Current timeout value */
98 ktime_t rq_rtt; /* round-trip time */
99 unsigned int rq_retries; /* # of retries */
100 unsigned int rq_connect_cookie;
101 /* A cookie used to track the
102 state of the transport
106 * Partial send handling
108 u32 rq_bytes_sent; /* Bytes we have sent */
110 ktime_t rq_xtime; /* transmit time stamp */
113 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
114 struct list_head rq_bc_list; /* Callback service list */
115 unsigned long rq_bc_pa_state; /* Backchannel prealloc state */
116 struct list_head rq_bc_pa_list; /* Backchannel prealloc list */
117 #endif /* CONFIG_SUNRPC_BACKCHANEL */
119 #define rq_svec rq_snd_buf.head
120 #define rq_slen rq_snd_buf.len
122 struct rpc_xprt_ops {
123 void (*set_buffer_size)(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize);
124 int (*reserve_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
125 void (*release_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
126 void (*alloc_slot)(struct rpc_xprt *xprt, struct rpc_task *task);
127 void (*rpcbind)(struct rpc_task *task);
128 void (*set_port)(struct rpc_xprt *xprt, unsigned short port);
129 void (*connect)(struct rpc_xprt *xprt, struct rpc_task *task);
130 void * (*buf_alloc)(struct rpc_task *task, size_t size);
131 void (*buf_free)(void *buffer);
132 int (*send_request)(struct rpc_task *task);
133 void (*set_retrans_timeout)(struct rpc_task *task);
134 void (*timer)(struct rpc_xprt *xprt, struct rpc_task *task);
135 void (*release_request)(struct rpc_task *task);
136 void (*close)(struct rpc_xprt *xprt);
137 void (*destroy)(struct rpc_xprt *xprt);
138 void (*print_stats)(struct rpc_xprt *xprt, struct seq_file *seq);
139 int (*enable_swap)(struct rpc_xprt *xprt);
140 void (*disable_swap)(struct rpc_xprt *xprt);
141 void (*inject_disconnect)(struct rpc_xprt *xprt);
142 int (*bc_setup)(struct rpc_xprt *xprt,
143 unsigned int min_reqs);
144 int (*bc_up)(struct svc_serv *serv, struct net *net);
145 void (*bc_free_rqst)(struct rpc_rqst *rqst);
146 void (*bc_destroy)(struct rpc_xprt *xprt,
147 unsigned int max_reqs);
151 * RPC transport identifiers
153 * To preserve compatibility with the historical use of raw IP protocol
154 * id's for transport selection, UDP and TCP identifiers are specified
155 * with the previous values. No such restriction exists for new transports,
156 * except that they may not collide with these values (17 and 6,
159 #define XPRT_TRANSPORT_BC (1 << 31)
160 enum xprt_transports {
161 XPRT_TRANSPORT_UDP = IPPROTO_UDP,
162 XPRT_TRANSPORT_TCP = IPPROTO_TCP,
163 XPRT_TRANSPORT_BC_TCP = IPPROTO_TCP | XPRT_TRANSPORT_BC,
164 XPRT_TRANSPORT_RDMA = 256,
165 XPRT_TRANSPORT_BC_RDMA = XPRT_TRANSPORT_RDMA | XPRT_TRANSPORT_BC,
166 XPRT_TRANSPORT_LOCAL = 257,
170 struct kref kref; /* Reference count */
171 struct rpc_xprt_ops * ops; /* transport methods */
173 const struct rpc_timeout *timeout; /* timeout parms */
174 struct sockaddr_storage addr; /* server address */
175 size_t addrlen; /* size of server address */
176 int prot; /* IP protocol */
178 unsigned long cong; /* current congestion */
179 unsigned long cwnd; /* congestion window */
181 size_t max_payload; /* largest RPC payload size,
183 unsigned int tsh_size; /* size of transport specific
186 struct rpc_wait_queue binding; /* requests waiting on rpcbind */
187 struct rpc_wait_queue sending; /* requests waiting to send */
188 struct rpc_wait_queue pending; /* requests in flight */
189 struct rpc_wait_queue backlog; /* waiting for slot */
190 struct list_head free; /* free slots */
191 unsigned int max_reqs; /* max number of slots */
192 unsigned int min_reqs; /* min number of slots */
193 atomic_t num_reqs; /* total slots */
194 unsigned long state; /* transport state */
195 unsigned char resvport : 1; /* use a reserved port */
196 atomic_t swapper; /* we're swapping over this
198 unsigned int bind_index; /* bind function index */
201 * Connection of transports
203 unsigned long bind_timeout,
205 unsigned int connect_cookie; /* A cookie that gets bumped
206 every time the transport
210 * Disconnection of idle transports
212 struct work_struct task_cleanup;
213 struct timer_list timer;
214 unsigned long last_used,
220 spinlock_t transport_lock; /* lock transport info */
221 spinlock_t reserve_lock; /* lock slot table */
222 u32 xid; /* Next XID value to use */
223 struct rpc_task * snd_task; /* Task blocked in send */
224 struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */
225 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
226 struct svc_serv *bc_serv; /* The RPC service which will */
227 /* process the callback */
228 int bc_alloc_count; /* Total number of preallocs */
229 atomic_t bc_free_slots;
230 spinlock_t bc_pa_lock; /* Protects the preallocated
232 struct list_head bc_pa_list; /* List of preallocated
233 * backchannel rpc_rqst's */
234 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
235 struct list_head recv;
238 unsigned long bind_count, /* total number of binds */
239 connect_count, /* total number of connects */
240 connect_start, /* connect start timestamp */
241 connect_time, /* jiffies waiting for connect */
242 sends, /* how many complete requests */
243 recvs, /* how many complete requests */
244 bad_xids, /* lookup_rqst didn't find XID */
245 max_slots; /* max rpc_slots used */
247 unsigned long long req_u, /* average requests on the wire */
248 bklog_u, /* backlog queue utilization */
249 sending_u, /* send q utilization */
250 pending_u; /* pend q utilization */
253 struct net *xprt_net;
254 const char *servername;
255 const char *address_strings[RPC_DISPLAY_MAX];
256 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
257 struct dentry *debugfs; /* debugfs directory */
258 atomic_t inject_disconnect;
263 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
267 #define RPC_BC_PA_IN_USE 0x0001 /* Preallocated backchannel */
269 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
271 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
272 static inline int bc_prealloc(struct rpc_rqst *req)
274 return test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
277 static inline int bc_prealloc(struct rpc_rqst *req)
281 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
283 #define XPRT_CREATE_INFINITE_SLOTS (1U)
284 #define XPRT_CREATE_NO_IDLE_TIMEOUT (1U << 1)
287 int ident; /* XPRT_TRANSPORT identifier */
289 struct sockaddr * srcaddr; /* optional local address */
290 struct sockaddr * dstaddr; /* remote peer address */
292 const char *servername;
293 struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */
298 struct list_head list;
299 int ident; /* XPRT_TRANSPORT identifier */
300 struct rpc_xprt * (*setup)(struct xprt_create *);
301 struct module *owner;
306 * Generic internal transport functions
308 struct rpc_xprt *xprt_create_transport(struct xprt_create *args);
309 void xprt_connect(struct rpc_task *task);
310 void xprt_reserve(struct rpc_task *task);
311 void xprt_retry_reserve(struct rpc_task *task);
312 int xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
313 int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
314 void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
315 void xprt_lock_and_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
316 bool xprt_prepare_transmit(struct rpc_task *task);
317 void xprt_transmit(struct rpc_task *task);
318 void xprt_end_transmit(struct rpc_task *task);
319 int xprt_adjust_timeout(struct rpc_rqst *req);
320 void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
321 void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
322 void xprt_release(struct rpc_task *task);
323 struct rpc_xprt * xprt_get(struct rpc_xprt *xprt);
324 void xprt_put(struct rpc_xprt *xprt);
325 struct rpc_xprt * xprt_alloc(struct net *net, size_t size,
326 unsigned int num_prealloc,
327 unsigned int max_req);
328 void xprt_free(struct rpc_xprt *);
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 */