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/sunrpc/sched.h>
16 #include <linux/sunrpc/xdr.h>
19 * The transport code maintains an estimate on the maximum number of out-
20 * standing RPC requests, using a smoothed version of the congestion
21 * avoidance implemented in 44BSD. This is basically the Van Jacobson
22 * congestion algorithm: If a retransmit occurs, the congestion window is
23 * halved; otherwise, it is incremented by 1/cwnd when
25 * - a reply is received and
26 * - a full number of requests are outstanding and
27 * - the congestion window hasn't been updated recently.
29 * Upper procedures may check whether a request would block waiting for
30 * a free RPC slot by using the RPC_CONGESTED() macro.
32 extern unsigned int xprt_udp_slot_table_entries;
33 extern unsigned int xprt_tcp_slot_table_entries;
35 #define RPC_MIN_SLOT_TABLE (2U)
36 #define RPC_DEF_SLOT_TABLE (16U)
37 #define RPC_MAX_SLOT_TABLE (128U)
39 #define RPC_CWNDSHIFT (8U)
40 #define RPC_CWNDSCALE (1U << RPC_CWNDSHIFT)
41 #define RPC_INITCWND RPC_CWNDSCALE
42 #define RPC_MAXCWND(xprt) ((xprt)->max_reqs << RPC_CWNDSHIFT)
43 #define RPCXPRT_CONGESTED(xprt) ((xprt)->cong >= (xprt)->cwnd)
45 /* Default timeout values */
46 #define RPC_MAX_UDP_TIMEOUT (60*HZ)
47 #define RPC_MAX_TCP_TIMEOUT (600*HZ)
50 * Wait duration for an RPC TCP connection to be established. Solaris
51 * NFS over TCP uses 60 seconds, for example, which is in line with how
52 * long a server takes to reboot.
54 #define RPC_CONNECT_TIMEOUT (60*HZ)
57 * Delay an arbitrary number of seconds before attempting to reconnect
60 #define RPC_REESTABLISH_TIMEOUT (15*HZ)
63 * RPC transport idle timeout.
65 #define RPC_IDLE_DISCONNECT_TIMEOUT (5*60*HZ)
68 * RPC call and reply header size as number of 32bit words (verifier
69 * size computed separately)
71 #define RPC_CALLHDRSIZE 6
72 #define RPC_REPHDRSIZE 4
75 * This describes a timeout strategy
78 unsigned long to_initval, /* initial timeout */
79 to_maxval, /* max timeout */
80 to_increment; /* if !exponential */
81 unsigned int to_retries; /* max # of retries */
82 unsigned char to_exponential;
86 * This describes a complete RPC request
90 * This is the user-visible part
92 struct rpc_xprt * rq_xprt; /* RPC client */
93 struct xdr_buf rq_snd_buf; /* send buffer */
94 struct xdr_buf rq_rcv_buf; /* recv buffer */
97 * This is the private part
99 struct rpc_task * rq_task; /* RPC task data */
100 __u32 rq_xid; /* request XID */
101 int rq_cong; /* has incremented xprt->cong */
102 int rq_received; /* receive completed */
103 u32 rq_seqno; /* gss seq no. used on req. */
105 struct list_head rq_list;
107 struct xdr_buf rq_private_buf; /* The receive buffer
108 * used in the softirq.
110 unsigned long rq_majortimeo; /* major timeout alarm */
111 unsigned long rq_timeout; /* Current timeout value */
112 unsigned int rq_retries; /* # of retries */
114 * For authentication (e.g. auth_des)
119 * Partial send handling
122 u32 rq_bytes_sent; /* Bytes we have sent */
124 unsigned long rq_xtime; /* when transmitted */
127 #define rq_svec rq_snd_buf.head
128 #define rq_slen rq_snd_buf.len
133 struct rpc_xprt_ops {
134 void (*set_buffer_size)(struct rpc_xprt *xprt);
135 int (*reserve_xprt)(struct rpc_task *task);
136 void (*release_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
137 void (*connect)(struct rpc_task *task);
138 int (*send_request)(struct rpc_task *task);
139 void (*set_retrans_timeout)(struct rpc_task *task);
140 void (*timer)(struct rpc_task *task);
141 void (*release_request)(struct rpc_task *task);
142 void (*close)(struct rpc_xprt *xprt);
143 void (*destroy)(struct rpc_xprt *xprt);
147 struct rpc_xprt_ops * ops; /* transport methods */
148 struct socket * sock; /* BSD socket layer */
149 struct sock * inet; /* INET layer */
151 struct rpc_timeout timeout; /* timeout parms */
152 struct sockaddr_in addr; /* server address */
153 int prot; /* IP protocol */
155 unsigned long cong; /* current congestion */
156 unsigned long cwnd; /* congestion window */
158 unsigned int rcvsize, /* transport rcv buffer size */
159 sndsize; /* transport send buffer size */
161 size_t max_payload; /* largest RPC payload size,
163 unsigned int tsh_size; /* size of transport specific
166 struct rpc_wait_queue sending; /* requests waiting to send */
167 struct rpc_wait_queue resend; /* requests waiting to resend */
168 struct rpc_wait_queue pending; /* requests in flight */
169 struct rpc_wait_queue backlog; /* waiting for slot */
170 struct list_head free; /* free slots */
171 struct rpc_rqst * slot; /* slot table storage */
172 unsigned int max_reqs; /* total slots */
173 unsigned long state; /* transport state */
174 unsigned char shutdown : 1, /* being shut down */
175 resvport : 1; /* use a reserved port */
180 __u32 xid; /* Next XID value to use */
183 * State of TCP reply receive stuff
185 u32 tcp_recm, /* Fragment header */
186 tcp_xid, /* Current XID */
187 tcp_reclen, /* fragment length */
188 tcp_offset; /* fragment offset */
189 unsigned long tcp_copied, /* copied to request */
192 * Connection of transports
194 struct work_struct connect_worker;
197 * Disconnection of idle transports
199 struct work_struct task_cleanup;
200 struct timer_list timer;
201 unsigned long last_used;
206 spinlock_t transport_lock; /* lock transport info */
207 spinlock_t reserve_lock; /* lock slot table */
208 struct rpc_task * snd_task; /* Task blocked in send */
210 struct list_head recv;
213 void (*old_data_ready)(struct sock *, int);
214 void (*old_state_change)(struct sock *);
215 void (*old_write_space)(struct sock *);
217 wait_queue_head_t cong_wait;
220 #define XPRT_LAST_FRAG (1 << 0)
221 #define XPRT_COPY_RECM (1 << 1)
222 #define XPRT_COPY_XID (1 << 2)
223 #define XPRT_COPY_DATA (1 << 3)
228 * Transport operations used by ULPs
230 struct rpc_xprt * xprt_create_proto(int proto, struct sockaddr_in *addr, struct rpc_timeout *to);
231 void xprt_set_timeout(struct rpc_timeout *to, unsigned int retr, unsigned long incr);
234 * Generic internal transport functions
236 void xprt_connect(struct rpc_task *task);
237 void xprt_reserve(struct rpc_task *task);
238 int xprt_reserve_xprt(struct rpc_task *task);
239 int xprt_reserve_xprt_cong(struct rpc_task *task);
240 int xprt_prepare_transmit(struct rpc_task *task);
241 void xprt_transmit(struct rpc_task *task);
242 int xprt_adjust_timeout(struct rpc_rqst *req);
243 void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
244 void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
245 void xprt_release(struct rpc_task *task);
246 int xprt_destroy(struct rpc_xprt *xprt);
248 static inline u32 *xprt_skip_transport_header(struct rpc_xprt *xprt, u32 *p)
250 return p + xprt->tsh_size;
254 * Transport switch helper functions
256 void xprt_set_retrans_timeout_def(struct rpc_task *task);
257 void xprt_set_retrans_timeout_rtt(struct rpc_task *task);
258 void xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status);
259 void xprt_wait_for_buffer_space(struct rpc_task *task);
260 void xprt_write_space(struct rpc_xprt *xprt);
261 void xprt_update_rtt(struct rpc_task *task);
262 void xprt_adjust_cwnd(struct rpc_task *task, int result);
263 struct rpc_rqst * xprt_lookup_rqst(struct rpc_xprt *xprt, u32 xid);
264 void xprt_complete_rqst(struct rpc_task *task, int copied);
265 void xprt_release_rqst_cong(struct rpc_task *task);
266 void xprt_disconnect(struct rpc_xprt *xprt);
269 * Socket transport setup operations
271 int xs_setup_udp(struct rpc_xprt *xprt, struct rpc_timeout *to);
272 int xs_setup_tcp(struct rpc_xprt *xprt, struct rpc_timeout *to);
275 * Reserved bit positions in xprt->state
277 #define XPRT_LOCKED (0)
278 #define XPRT_CONNECTED (1)
279 #define XPRT_CONNECTING (2)
281 static inline void xprt_set_connected(struct rpc_xprt *xprt)
283 set_bit(XPRT_CONNECTED, &xprt->state);
286 static inline void xprt_clear_connected(struct rpc_xprt *xprt)
288 clear_bit(XPRT_CONNECTED, &xprt->state);
291 static inline int xprt_connected(struct rpc_xprt *xprt)
293 return test_bit(XPRT_CONNECTED, &xprt->state);
296 static inline int xprt_test_and_set_connected(struct rpc_xprt *xprt)
298 return test_and_set_bit(XPRT_CONNECTED, &xprt->state);
301 static inline int xprt_test_and_clear_connected(struct rpc_xprt *xprt)
303 return test_and_clear_bit(XPRT_CONNECTED, &xprt->state);
306 static inline void xprt_clear_connecting(struct rpc_xprt *xprt)
308 smp_mb__before_clear_bit();
309 clear_bit(XPRT_CONNECTING, &xprt->state);
310 smp_mb__after_clear_bit();
313 static inline int xprt_connecting(struct rpc_xprt *xprt)
315 return test_bit(XPRT_CONNECTING, &xprt->state);
318 static inline int xprt_test_and_set_connecting(struct rpc_xprt *xprt)
320 return test_and_set_bit(XPRT_CONNECTING, &xprt->state);
323 #endif /* __KERNEL__*/
325 #endif /* _LINUX_SUNRPC_XPRT_H */