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>
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 {
61 * This describes a complete RPC request
65 * This is the user-visible part
67 struct rpc_xprt * rq_xprt; /* RPC client */
68 struct xdr_buf rq_snd_buf; /* send buffer */
69 struct xdr_buf rq_rcv_buf; /* recv buffer */
72 * This is the private part
74 struct rpc_task * rq_task; /* RPC task data */
75 struct rpc_cred * rq_cred; /* Bound cred */
76 __be32 rq_xid; /* request XID */
77 int rq_cong; /* has incremented xprt->cong */
78 u32 rq_seqno; /* gss seq no. used on req. */
80 struct page **rq_enc_pages; /* scratch pages for use by
82 void (*rq_release_snd_buf)(struct rpc_rqst *); /* release rq_enc_pages */
85 struct list_head rq_list; /* Slot allocation list */
86 struct rb_node rq_recv; /* Receive queue */
89 struct list_head rq_xmit; /* Send queue */
90 struct list_head rq_xmit2; /* Send queue */
92 void *rq_buffer; /* Call XDR encode buffer */
94 void *rq_rbuffer; /* Reply XDR decode buffer */
96 size_t rq_xmit_bytes_sent; /* total bytes sent */
97 size_t rq_reply_bytes_recvd; /* total reply bytes */
100 struct xdr_buf rq_private_buf; /* The receive buffer
101 * used in the softirq.
103 unsigned long rq_majortimeo; /* major timeout alarm */
104 unsigned long rq_timeout; /* Current timeout value */
105 ktime_t rq_rtt; /* round-trip time */
106 unsigned int rq_retries; /* # of retries */
107 unsigned int rq_connect_cookie;
108 /* A cookie used to track the
109 state of the transport
114 * Partial send handling
116 u32 rq_bytes_sent; /* Bytes we have sent */
118 ktime_t rq_xtime; /* transmit time stamp */
121 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
122 struct list_head rq_bc_list; /* Callback service list */
123 unsigned long rq_bc_pa_state; /* Backchannel prealloc state */
124 struct list_head rq_bc_pa_list; /* Backchannel prealloc list */
125 #endif /* CONFIG_SUNRPC_BACKCHANEL */
127 #define rq_svec rq_snd_buf.head
128 #define rq_slen rq_snd_buf.len
130 struct rpc_xprt_ops {
131 void (*set_buffer_size)(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize);
132 int (*reserve_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
133 void (*release_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
134 void (*alloc_slot)(struct rpc_xprt *xprt, struct rpc_task *task);
135 void (*free_slot)(struct rpc_xprt *xprt,
136 struct rpc_rqst *req);
137 void (*rpcbind)(struct rpc_task *task);
138 void (*set_port)(struct rpc_xprt *xprt, unsigned short port);
139 void (*connect)(struct rpc_xprt *xprt, struct rpc_task *task);
140 int (*buf_alloc)(struct rpc_task *task);
141 void (*buf_free)(struct rpc_task *task);
142 void (*prepare_request)(struct rpc_rqst *req);
143 int (*send_request)(struct rpc_rqst *req);
144 void (*wait_for_reply_request)(struct rpc_task *task);
145 void (*timer)(struct rpc_xprt *xprt, struct rpc_task *task);
146 void (*release_request)(struct rpc_task *task);
147 void (*close)(struct rpc_xprt *xprt);
148 void (*destroy)(struct rpc_xprt *xprt);
149 void (*set_connect_timeout)(struct rpc_xprt *xprt,
150 unsigned long connect_timeout,
151 unsigned long reconnect_timeout);
152 void (*print_stats)(struct rpc_xprt *xprt, struct seq_file *seq);
153 int (*enable_swap)(struct rpc_xprt *xprt);
154 void (*disable_swap)(struct rpc_xprt *xprt);
155 void (*inject_disconnect)(struct rpc_xprt *xprt);
156 int (*bc_setup)(struct rpc_xprt *xprt,
157 unsigned int min_reqs);
158 size_t (*bc_maxpayload)(struct rpc_xprt *xprt);
159 unsigned int (*bc_num_slots)(struct rpc_xprt *xprt);
160 void (*bc_free_rqst)(struct rpc_rqst *rqst);
161 void (*bc_destroy)(struct rpc_xprt *xprt,
162 unsigned int max_reqs);
166 * RPC transport identifiers
168 * To preserve compatibility with the historical use of raw IP protocol
169 * id's for transport selection, UDP and TCP identifiers are specified
170 * with the previous values. No such restriction exists for new transports,
171 * except that they may not collide with these values (17 and 6,
174 #define XPRT_TRANSPORT_BC (1 << 31)
175 enum xprt_transports {
176 XPRT_TRANSPORT_UDP = IPPROTO_UDP,
177 XPRT_TRANSPORT_TCP = IPPROTO_TCP,
178 XPRT_TRANSPORT_BC_TCP = IPPROTO_TCP | XPRT_TRANSPORT_BC,
179 XPRT_TRANSPORT_RDMA = 256,
180 XPRT_TRANSPORT_BC_RDMA = XPRT_TRANSPORT_RDMA | XPRT_TRANSPORT_BC,
181 XPRT_TRANSPORT_LOCAL = 257,
185 struct kref kref; /* Reference count */
186 const struct rpc_xprt_ops *ops; /* transport methods */
188 const struct rpc_timeout *timeout; /* timeout parms */
189 struct sockaddr_storage addr; /* server address */
190 size_t addrlen; /* size of server address */
191 int prot; /* IP protocol */
193 unsigned long cong; /* current congestion */
194 unsigned long cwnd; /* congestion window */
196 size_t max_payload; /* largest RPC payload size,
199 struct rpc_wait_queue binding; /* requests waiting on rpcbind */
200 struct rpc_wait_queue sending; /* requests waiting to send */
201 struct rpc_wait_queue pending; /* requests in flight */
202 struct rpc_wait_queue backlog; /* waiting for slot */
203 struct list_head free; /* free slots */
204 unsigned int max_reqs; /* max number of slots */
205 unsigned int min_reqs; /* min number of slots */
206 unsigned int num_reqs; /* total slots */
207 unsigned long state; /* transport state */
208 unsigned char resvport : 1, /* use a reserved port */
209 reuseport : 1; /* reuse port on reconnect */
210 atomic_t swapper; /* we're swapping over this
212 unsigned int bind_index; /* bind function index */
217 struct list_head xprt_switch;
220 * Connection of transports
222 unsigned long bind_timeout,
224 unsigned int connect_cookie; /* A cookie that gets bumped
225 every time the transport
229 * Disconnection of idle transports
231 struct work_struct task_cleanup;
232 struct timer_list timer;
233 unsigned long last_used,
236 max_reconnect_timeout;
241 atomic_long_t queuelen;
242 spinlock_t transport_lock; /* lock transport info */
243 spinlock_t reserve_lock; /* lock slot table */
244 spinlock_t queue_lock; /* send/receive queue lock */
245 u32 xid; /* Next XID value to use */
246 struct rpc_task * snd_task; /* Task blocked in send */
248 struct list_head xmit_queue; /* Send queue */
250 struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */
251 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
252 struct svc_serv *bc_serv; /* The RPC service which will */
253 /* process the callback */
254 unsigned int bc_alloc_max;
255 unsigned int bc_alloc_count; /* Total number of preallocs */
256 atomic_t bc_slot_count; /* Number of allocated slots */
257 spinlock_t bc_pa_lock; /* Protects the preallocated
259 struct list_head bc_pa_list; /* List of preallocated
260 * backchannel rpc_rqst's */
261 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
263 struct rb_root recv_queue; /* Receive queue */
266 unsigned long bind_count, /* total number of binds */
267 connect_count, /* total number of connects */
268 connect_start, /* connect start timestamp */
269 connect_time, /* jiffies waiting for connect */
270 sends, /* how many complete requests */
271 recvs, /* how many complete requests */
272 bad_xids, /* lookup_rqst didn't find XID */
273 max_slots; /* max rpc_slots used */
275 unsigned long long req_u, /* average requests on the wire */
276 bklog_u, /* backlog queue utilization */
277 sending_u, /* send q utilization */
278 pending_u; /* pend q utilization */
281 struct net *xprt_net;
282 const char *servername;
283 const char *address_strings[RPC_DISPLAY_MAX];
284 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
285 struct dentry *debugfs; /* debugfs directory */
286 atomic_t inject_disconnect;
291 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
295 #define RPC_BC_PA_IN_USE 0x0001 /* Preallocated backchannel */
297 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
299 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
300 static inline int bc_prealloc(struct rpc_rqst *req)
302 return test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
305 static inline int bc_prealloc(struct rpc_rqst *req)
309 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
311 #define XPRT_CREATE_INFINITE_SLOTS (1U)
312 #define XPRT_CREATE_NO_IDLE_TIMEOUT (1U << 1)
315 int ident; /* XPRT_TRANSPORT identifier */
317 struct sockaddr * srcaddr; /* optional local address */
318 struct sockaddr * dstaddr; /* remote peer address */
320 const char *servername;
321 struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */
322 struct rpc_xprt_switch *bc_xps;
327 struct list_head list;
328 int ident; /* XPRT_TRANSPORT identifier */
329 struct rpc_xprt * (*setup)(struct xprt_create *);
330 struct module *owner;
335 * Generic internal transport functions
337 struct rpc_xprt *xprt_create_transport(struct xprt_create *args);
338 void xprt_connect(struct rpc_task *task);
339 unsigned long xprt_reconnect_delay(const struct rpc_xprt *xprt);
340 void xprt_reconnect_backoff(struct rpc_xprt *xprt,
341 unsigned long init_to);
342 void xprt_reserve(struct rpc_task *task);
343 void xprt_retry_reserve(struct rpc_task *task);
344 int xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
345 int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
346 void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
347 void xprt_free_slot(struct rpc_xprt *xprt,
348 struct rpc_rqst *req);
349 void xprt_request_prepare(struct rpc_rqst *req);
350 bool xprt_prepare_transmit(struct rpc_task *task);
351 void xprt_request_enqueue_transmit(struct rpc_task *task);
352 void xprt_request_enqueue_receive(struct rpc_task *task);
353 void xprt_request_wait_receive(struct rpc_task *task);
354 void xprt_request_dequeue_xprt(struct rpc_task *task);
355 bool xprt_request_need_retransmit(struct rpc_task *task);
356 void xprt_transmit(struct rpc_task *task);
357 void xprt_end_transmit(struct rpc_task *task);
358 int xprt_adjust_timeout(struct rpc_rqst *req);
359 void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
360 void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
361 void xprt_release(struct rpc_task *task);
362 struct rpc_xprt * xprt_get(struct rpc_xprt *xprt);
363 void xprt_put(struct rpc_xprt *xprt);
364 struct rpc_xprt * xprt_alloc(struct net *net, size_t size,
365 unsigned int num_prealloc,
366 unsigned int max_req);
367 void xprt_free(struct rpc_xprt *);
370 xprt_enable_swap(struct rpc_xprt *xprt)
372 return xprt->ops->enable_swap(xprt);
376 xprt_disable_swap(struct rpc_xprt *xprt)
378 xprt->ops->disable_swap(xprt);
382 * Transport switch helper functions
384 int xprt_register_transport(struct xprt_class *type);
385 int xprt_unregister_transport(struct xprt_class *type);
386 int xprt_load_transport(const char *);
387 void xprt_wait_for_reply_request_def(struct rpc_task *task);
388 void xprt_wait_for_reply_request_rtt(struct rpc_task *task);
389 void xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status);
390 void xprt_wait_for_buffer_space(struct rpc_xprt *xprt);
391 bool xprt_write_space(struct rpc_xprt *xprt);
392 void xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result);
393 struct rpc_rqst * xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid);
394 void xprt_update_rtt(struct rpc_task *task);
395 void xprt_complete_rqst(struct rpc_task *task, int copied);
396 void xprt_pin_rqst(struct rpc_rqst *req);
397 void xprt_unpin_rqst(struct rpc_rqst *req);
398 void xprt_release_rqst_cong(struct rpc_task *task);
399 bool xprt_request_get_cong(struct rpc_xprt *xprt, struct rpc_rqst *req);
400 void xprt_disconnect_done(struct rpc_xprt *xprt);
401 void xprt_force_disconnect(struct rpc_xprt *xprt);
402 void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie);
404 bool xprt_lock_connect(struct rpc_xprt *, struct rpc_task *, void *);
405 void xprt_unlock_connect(struct rpc_xprt *, void *);
408 * Reserved bit positions in xprt->state
410 #define XPRT_LOCKED (0)
411 #define XPRT_CONNECTED (1)
412 #define XPRT_CONNECTING (2)
413 #define XPRT_CLOSE_WAIT (3)
414 #define XPRT_BOUND (4)
415 #define XPRT_BINDING (5)
416 #define XPRT_CLOSING (6)
417 #define XPRT_CONGESTED (9)
418 #define XPRT_CWND_WAIT (10)
419 #define XPRT_WRITE_SPACE (11)
421 static inline void xprt_set_connected(struct rpc_xprt *xprt)
423 set_bit(XPRT_CONNECTED, &xprt->state);
426 static inline void xprt_clear_connected(struct rpc_xprt *xprt)
428 clear_bit(XPRT_CONNECTED, &xprt->state);
431 static inline int xprt_connected(struct rpc_xprt *xprt)
433 return test_bit(XPRT_CONNECTED, &xprt->state);
436 static inline int xprt_test_and_set_connected(struct rpc_xprt *xprt)
438 return test_and_set_bit(XPRT_CONNECTED, &xprt->state);
441 static inline int xprt_test_and_clear_connected(struct rpc_xprt *xprt)
443 return test_and_clear_bit(XPRT_CONNECTED, &xprt->state);
446 static inline void xprt_clear_connecting(struct rpc_xprt *xprt)
448 smp_mb__before_atomic();
449 clear_bit(XPRT_CONNECTING, &xprt->state);
450 smp_mb__after_atomic();
453 static inline int xprt_connecting(struct rpc_xprt *xprt)
455 return test_bit(XPRT_CONNECTING, &xprt->state);
458 static inline int xprt_test_and_set_connecting(struct rpc_xprt *xprt)
460 return test_and_set_bit(XPRT_CONNECTING, &xprt->state);
463 static inline void xprt_set_bound(struct rpc_xprt *xprt)
465 test_and_set_bit(XPRT_BOUND, &xprt->state);
468 static inline int xprt_bound(struct rpc_xprt *xprt)
470 return test_bit(XPRT_BOUND, &xprt->state);
473 static inline void xprt_clear_bound(struct rpc_xprt *xprt)
475 clear_bit(XPRT_BOUND, &xprt->state);
478 static inline void xprt_clear_binding(struct rpc_xprt *xprt)
480 smp_mb__before_atomic();
481 clear_bit(XPRT_BINDING, &xprt->state);
482 smp_mb__after_atomic();
485 static inline int xprt_test_and_set_binding(struct rpc_xprt *xprt)
487 return test_and_set_bit(XPRT_BINDING, &xprt->state);
490 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
491 extern unsigned int rpc_inject_disconnect;
492 static inline void xprt_inject_disconnect(struct rpc_xprt *xprt)
494 if (!rpc_inject_disconnect)
496 if (atomic_dec_return(&xprt->inject_disconnect))
498 atomic_set(&xprt->inject_disconnect, rpc_inject_disconnect);
499 xprt->ops->inject_disconnect(xprt);
502 static inline void xprt_inject_disconnect(struct rpc_xprt *xprt)
507 #endif /* _LINUX_SUNRPC_XPRT_H */