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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/net/sunrpc/xprt.c | |
3 | * | |
4 | * This is a generic RPC call interface supporting congestion avoidance, | |
5 | * and asynchronous calls. | |
6 | * | |
7 | * The interface works like this: | |
8 | * | |
9 | * - When a process places a call, it allocates a request slot if | |
10 | * one is available. Otherwise, it sleeps on the backlog queue | |
11 | * (xprt_reserve). | |
12 | * - Next, the caller puts together the RPC message, stuffs it into | |
13 | * the request struct, and calls xprt_call(). | |
14 | * - xprt_call transmits the message and installs the caller on the | |
15 | * socket's wait list. At the same time, it installs a timer that | |
16 | * is run after the packet's timeout has expired. | |
17 | * - When a packet arrives, the data_ready handler walks the list of | |
18 | * pending requests for that socket. If a matching XID is found, the | |
19 | * caller is woken up, and the timer removed. | |
20 | * - When no reply arrives within the timeout interval, the timer is | |
21 | * fired by the kernel and runs xprt_timer(). It either adjusts the | |
22 | * timeout values (minor timeout) or wakes up the caller with a status | |
23 | * of -ETIMEDOUT. | |
24 | * - When the caller receives a notification from RPC that a reply arrived, | |
25 | * it should release the RPC slot, and process the reply. | |
26 | * If the call timed out, it may choose to retry the operation by | |
27 | * adjusting the initial timeout value, and simply calling rpc_call | |
28 | * again. | |
29 | * | |
30 | * Support for async RPC is done through a set of RPC-specific scheduling | |
31 | * primitives that `transparently' work for processes as well as async | |
32 | * tasks that rely on callbacks. | |
33 | * | |
34 | * Copyright (C) 1995-1997, Olaf Kirch <okir@monad.swb.de> | |
1da177e4 LT |
35 | */ |
36 | ||
a246b010 CL |
37 | #include <linux/module.h> |
38 | ||
1da177e4 | 39 | #include <linux/types.h> |
a246b010 | 40 | #include <linux/interrupt.h> |
1da177e4 LT |
41 | #include <linux/workqueue.h> |
42 | #include <linux/random.h> | |
43 | ||
a246b010 | 44 | #include <linux/sunrpc/clnt.h> |
1da177e4 LT |
45 | |
46 | /* | |
47 | * Local variables | |
48 | */ | |
49 | ||
50 | #ifdef RPC_DEBUG | |
51 | # undef RPC_DEBUG_DATA | |
52 | # define RPCDBG_FACILITY RPCDBG_XPRT | |
53 | #endif | |
54 | ||
55 | #define XPRT_MAX_BACKOFF (8) | |
1da177e4 LT |
56 | |
57 | /* | |
58 | * Local functions | |
59 | */ | |
60 | static void xprt_request_init(struct rpc_task *, struct rpc_xprt *); | |
61 | static inline void do_xprt_reserve(struct rpc_task *); | |
1da177e4 | 62 | static void xprt_connect_status(struct rpc_task *task); |
1da177e4 LT |
63 | static int __xprt_get_cong(struct rpc_xprt *, struct rpc_task *); |
64 | ||
65 | static int xprt_clear_backlog(struct rpc_xprt *xprt); | |
66 | ||
1da177e4 LT |
67 | /* |
68 | * Serialize write access to sockets, in order to prevent different | |
69 | * requests from interfering with each other. | |
70 | * Also prevents TCP socket connects from colliding with writes. | |
71 | */ | |
72 | static int | |
73 | __xprt_lock_write(struct rpc_xprt *xprt, struct rpc_task *task) | |
74 | { | |
75 | struct rpc_rqst *req = task->tk_rqstp; | |
76 | ||
77 | if (test_and_set_bit(XPRT_LOCKED, &xprt->sockstate)) { | |
78 | if (task == xprt->snd_task) | |
79 | return 1; | |
1da177e4 LT |
80 | goto out_sleep; |
81 | } | |
82 | if (xprt->nocong || __xprt_get_cong(xprt, task)) { | |
83 | xprt->snd_task = task; | |
84 | if (req) { | |
85 | req->rq_bytes_sent = 0; | |
86 | req->rq_ntrans++; | |
87 | } | |
88 | return 1; | |
89 | } | |
90 | smp_mb__before_clear_bit(); | |
91 | clear_bit(XPRT_LOCKED, &xprt->sockstate); | |
92 | smp_mb__after_clear_bit(); | |
93 | out_sleep: | |
94 | dprintk("RPC: %4d failed to lock socket %p\n", task->tk_pid, xprt); | |
95 | task->tk_timeout = 0; | |
96 | task->tk_status = -EAGAIN; | |
97 | if (req && req->rq_ntrans) | |
98 | rpc_sleep_on(&xprt->resend, task, NULL, NULL); | |
99 | else | |
100 | rpc_sleep_on(&xprt->sending, task, NULL, NULL); | |
101 | return 0; | |
102 | } | |
103 | ||
104 | static inline int | |
105 | xprt_lock_write(struct rpc_xprt *xprt, struct rpc_task *task) | |
106 | { | |
107 | int retval; | |
108 | ||
4a0f8c04 | 109 | spin_lock_bh(&xprt->transport_lock); |
1da177e4 | 110 | retval = __xprt_lock_write(xprt, task); |
4a0f8c04 | 111 | spin_unlock_bh(&xprt->transport_lock); |
1da177e4 LT |
112 | return retval; |
113 | } | |
114 | ||
115 | ||
116 | static void | |
117 | __xprt_lock_write_next(struct rpc_xprt *xprt) | |
118 | { | |
119 | struct rpc_task *task; | |
120 | ||
121 | if (test_and_set_bit(XPRT_LOCKED, &xprt->sockstate)) | |
122 | return; | |
123 | if (!xprt->nocong && RPCXPRT_CONGESTED(xprt)) | |
124 | goto out_unlock; | |
125 | task = rpc_wake_up_next(&xprt->resend); | |
126 | if (!task) { | |
127 | task = rpc_wake_up_next(&xprt->sending); | |
128 | if (!task) | |
129 | goto out_unlock; | |
130 | } | |
131 | if (xprt->nocong || __xprt_get_cong(xprt, task)) { | |
132 | struct rpc_rqst *req = task->tk_rqstp; | |
133 | xprt->snd_task = task; | |
134 | if (req) { | |
135 | req->rq_bytes_sent = 0; | |
136 | req->rq_ntrans++; | |
137 | } | |
138 | return; | |
139 | } | |
140 | out_unlock: | |
141 | smp_mb__before_clear_bit(); | |
142 | clear_bit(XPRT_LOCKED, &xprt->sockstate); | |
143 | smp_mb__after_clear_bit(); | |
144 | } | |
145 | ||
146 | /* | |
147 | * Releases the socket for use by other requests. | |
148 | */ | |
149 | static void | |
150 | __xprt_release_write(struct rpc_xprt *xprt, struct rpc_task *task) | |
151 | { | |
152 | if (xprt->snd_task == task) { | |
153 | xprt->snd_task = NULL; | |
154 | smp_mb__before_clear_bit(); | |
155 | clear_bit(XPRT_LOCKED, &xprt->sockstate); | |
156 | smp_mb__after_clear_bit(); | |
157 | __xprt_lock_write_next(xprt); | |
158 | } | |
159 | } | |
160 | ||
161 | static inline void | |
162 | xprt_release_write(struct rpc_xprt *xprt, struct rpc_task *task) | |
163 | { | |
4a0f8c04 | 164 | spin_lock_bh(&xprt->transport_lock); |
1da177e4 | 165 | __xprt_release_write(xprt, task); |
4a0f8c04 | 166 | spin_unlock_bh(&xprt->transport_lock); |
1da177e4 LT |
167 | } |
168 | ||
1da177e4 LT |
169 | /* |
170 | * Van Jacobson congestion avoidance. Check if the congestion window | |
171 | * overflowed. Put the task to sleep if this is the case. | |
172 | */ | |
173 | static int | |
174 | __xprt_get_cong(struct rpc_xprt *xprt, struct rpc_task *task) | |
175 | { | |
176 | struct rpc_rqst *req = task->tk_rqstp; | |
177 | ||
178 | if (req->rq_cong) | |
179 | return 1; | |
180 | dprintk("RPC: %4d xprt_cwnd_limited cong = %ld cwnd = %ld\n", | |
181 | task->tk_pid, xprt->cong, xprt->cwnd); | |
182 | if (RPCXPRT_CONGESTED(xprt)) | |
183 | return 0; | |
184 | req->rq_cong = 1; | |
185 | xprt->cong += RPC_CWNDSCALE; | |
186 | return 1; | |
187 | } | |
188 | ||
189 | /* | |
190 | * Adjust the congestion window, and wake up the next task | |
191 | * that has been sleeping due to congestion | |
192 | */ | |
193 | static void | |
194 | __xprt_put_cong(struct rpc_xprt *xprt, struct rpc_rqst *req) | |
195 | { | |
196 | if (!req->rq_cong) | |
197 | return; | |
198 | req->rq_cong = 0; | |
199 | xprt->cong -= RPC_CWNDSCALE; | |
200 | __xprt_lock_write_next(xprt); | |
201 | } | |
202 | ||
203 | /* | |
204 | * Adjust RPC congestion window | |
205 | * We use a time-smoothed congestion estimator to avoid heavy oscillation. | |
206 | */ | |
207 | static void | |
208 | xprt_adjust_cwnd(struct rpc_xprt *xprt, int result) | |
209 | { | |
210 | unsigned long cwnd; | |
211 | ||
212 | cwnd = xprt->cwnd; | |
213 | if (result >= 0 && cwnd <= xprt->cong) { | |
214 | /* The (cwnd >> 1) term makes sure | |
215 | * the result gets rounded properly. */ | |
216 | cwnd += (RPC_CWNDSCALE * RPC_CWNDSCALE + (cwnd >> 1)) / cwnd; | |
217 | if (cwnd > RPC_MAXCWND(xprt)) | |
218 | cwnd = RPC_MAXCWND(xprt); | |
219 | __xprt_lock_write_next(xprt); | |
220 | } else if (result == -ETIMEDOUT) { | |
221 | cwnd >>= 1; | |
222 | if (cwnd < RPC_CWNDSCALE) | |
223 | cwnd = RPC_CWNDSCALE; | |
224 | } | |
225 | dprintk("RPC: cong %ld, cwnd was %ld, now %ld\n", | |
226 | xprt->cong, xprt->cwnd, cwnd); | |
227 | xprt->cwnd = cwnd; | |
228 | } | |
229 | ||
1da177e4 LT |
230 | static void xprt_reset_majortimeo(struct rpc_rqst *req) |
231 | { | |
232 | struct rpc_timeout *to = &req->rq_xprt->timeout; | |
233 | ||
234 | req->rq_majortimeo = req->rq_timeout; | |
235 | if (to->to_exponential) | |
236 | req->rq_majortimeo <<= to->to_retries; | |
237 | else | |
238 | req->rq_majortimeo += to->to_increment * to->to_retries; | |
239 | if (req->rq_majortimeo > to->to_maxval || req->rq_majortimeo == 0) | |
240 | req->rq_majortimeo = to->to_maxval; | |
241 | req->rq_majortimeo += jiffies; | |
242 | } | |
243 | ||
9903cd1c CL |
244 | /** |
245 | * xprt_adjust_timeout - adjust timeout values for next retransmit | |
246 | * @req: RPC request containing parameters to use for the adjustment | |
247 | * | |
1da177e4 LT |
248 | */ |
249 | int xprt_adjust_timeout(struct rpc_rqst *req) | |
250 | { | |
251 | struct rpc_xprt *xprt = req->rq_xprt; | |
252 | struct rpc_timeout *to = &xprt->timeout; | |
253 | int status = 0; | |
254 | ||
255 | if (time_before(jiffies, req->rq_majortimeo)) { | |
256 | if (to->to_exponential) | |
257 | req->rq_timeout <<= 1; | |
258 | else | |
259 | req->rq_timeout += to->to_increment; | |
260 | if (to->to_maxval && req->rq_timeout >= to->to_maxval) | |
261 | req->rq_timeout = to->to_maxval; | |
262 | req->rq_retries++; | |
263 | pprintk("RPC: %lu retrans\n", jiffies); | |
264 | } else { | |
265 | req->rq_timeout = to->to_initval; | |
266 | req->rq_retries = 0; | |
267 | xprt_reset_majortimeo(req); | |
268 | /* Reset the RTT counters == "slow start" */ | |
4a0f8c04 | 269 | spin_lock_bh(&xprt->transport_lock); |
1da177e4 | 270 | rpc_init_rtt(req->rq_task->tk_client->cl_rtt, to->to_initval); |
4a0f8c04 | 271 | spin_unlock_bh(&xprt->transport_lock); |
1da177e4 LT |
272 | pprintk("RPC: %lu timeout\n", jiffies); |
273 | status = -ETIMEDOUT; | |
274 | } | |
275 | ||
276 | if (req->rq_timeout == 0) { | |
277 | printk(KERN_WARNING "xprt_adjust_timeout: rq_timeout = 0!\n"); | |
278 | req->rq_timeout = 5 * HZ; | |
279 | } | |
280 | return status; | |
281 | } | |
282 | ||
1da177e4 LT |
283 | static void |
284 | xprt_socket_autoclose(void *args) | |
285 | { | |
286 | struct rpc_xprt *xprt = (struct rpc_xprt *)args; | |
287 | ||
288 | xprt_disconnect(xprt); | |
a246b010 | 289 | xprt->ops->close(xprt); |
1da177e4 LT |
290 | xprt_release_write(xprt, NULL); |
291 | } | |
292 | ||
9903cd1c CL |
293 | /** |
294 | * xprt_disconnect - mark a transport as disconnected | |
295 | * @xprt: transport to flag for disconnect | |
296 | * | |
1da177e4 | 297 | */ |
a246b010 | 298 | void xprt_disconnect(struct rpc_xprt *xprt) |
1da177e4 LT |
299 | { |
300 | dprintk("RPC: disconnected transport %p\n", xprt); | |
4a0f8c04 | 301 | spin_lock_bh(&xprt->transport_lock); |
1da177e4 LT |
302 | xprt_clear_connected(xprt); |
303 | rpc_wake_up_status(&xprt->pending, -ENOTCONN); | |
4a0f8c04 | 304 | spin_unlock_bh(&xprt->transport_lock); |
1da177e4 LT |
305 | } |
306 | ||
1da177e4 LT |
307 | static void |
308 | xprt_init_autodisconnect(unsigned long data) | |
309 | { | |
310 | struct rpc_xprt *xprt = (struct rpc_xprt *)data; | |
311 | ||
4a0f8c04 | 312 | spin_lock(&xprt->transport_lock); |
1da177e4 LT |
313 | if (!list_empty(&xprt->recv) || xprt->shutdown) |
314 | goto out_abort; | |
315 | if (test_and_set_bit(XPRT_LOCKED, &xprt->sockstate)) | |
316 | goto out_abort; | |
4a0f8c04 | 317 | spin_unlock(&xprt->transport_lock); |
1da177e4 LT |
318 | /* Let keventd close the socket */ |
319 | if (test_bit(XPRT_CONNECTING, &xprt->sockstate) != 0) | |
320 | xprt_release_write(xprt, NULL); | |
321 | else | |
322 | schedule_work(&xprt->task_cleanup); | |
323 | return; | |
324 | out_abort: | |
4a0f8c04 | 325 | spin_unlock(&xprt->transport_lock); |
1da177e4 LT |
326 | } |
327 | ||
9903cd1c CL |
328 | /** |
329 | * xprt_connect - schedule a transport connect operation | |
330 | * @task: RPC task that is requesting the connect | |
1da177e4 LT |
331 | * |
332 | */ | |
333 | void xprt_connect(struct rpc_task *task) | |
334 | { | |
335 | struct rpc_xprt *xprt = task->tk_xprt; | |
336 | ||
337 | dprintk("RPC: %4d xprt_connect xprt %p %s connected\n", task->tk_pid, | |
338 | xprt, (xprt_connected(xprt) ? "is" : "is not")); | |
339 | ||
340 | if (xprt->shutdown) { | |
341 | task->tk_status = -EIO; | |
342 | return; | |
343 | } | |
344 | if (!xprt->addr.sin_port) { | |
345 | task->tk_status = -EIO; | |
346 | return; | |
347 | } | |
348 | if (!xprt_lock_write(xprt, task)) | |
349 | return; | |
350 | if (xprt_connected(xprt)) | |
a246b010 CL |
351 | xprt_release_write(xprt, task); |
352 | else { | |
353 | if (task->tk_rqstp) | |
354 | task->tk_rqstp->rq_bytes_sent = 0; | |
1da177e4 | 355 | |
a246b010 CL |
356 | task->tk_timeout = RPC_CONNECT_TIMEOUT; |
357 | rpc_sleep_on(&xprt->pending, task, xprt_connect_status, NULL); | |
358 | xprt->ops->connect(task); | |
1da177e4 LT |
359 | } |
360 | return; | |
1da177e4 LT |
361 | } |
362 | ||
9903cd1c | 363 | static void xprt_connect_status(struct rpc_task *task) |
1da177e4 LT |
364 | { |
365 | struct rpc_xprt *xprt = task->tk_xprt; | |
366 | ||
367 | if (task->tk_status >= 0) { | |
368 | dprintk("RPC: %4d xprt_connect_status: connection established\n", | |
369 | task->tk_pid); | |
370 | return; | |
371 | } | |
372 | ||
1da177e4 LT |
373 | switch (task->tk_status) { |
374 | case -ECONNREFUSED: | |
375 | case -ECONNRESET: | |
23475d66 CL |
376 | dprintk("RPC: %4d xprt_connect_status: server %s refused connection\n", |
377 | task->tk_pid, task->tk_client->cl_server); | |
378 | break; | |
1da177e4 | 379 | case -ENOTCONN: |
23475d66 CL |
380 | dprintk("RPC: %4d xprt_connect_status: connection broken\n", |
381 | task->tk_pid); | |
382 | break; | |
1da177e4 | 383 | case -ETIMEDOUT: |
23475d66 | 384 | dprintk("RPC: %4d xprt_connect_status: connect attempt timed out\n", |
1da177e4 LT |
385 | task->tk_pid); |
386 | break; | |
387 | default: | |
23475d66 CL |
388 | dprintk("RPC: %4d xprt_connect_status: error %d connecting to server %s\n", |
389 | task->tk_pid, -task->tk_status, task->tk_client->cl_server); | |
390 | xprt_release_write(xprt, task); | |
391 | task->tk_status = -EIO; | |
392 | return; | |
393 | } | |
394 | ||
395 | /* if soft mounted, just cause this RPC to fail */ | |
396 | if (RPC_IS_SOFT(task)) { | |
397 | xprt_release_write(xprt, task); | |
398 | task->tk_status = -EIO; | |
1da177e4 | 399 | } |
1da177e4 LT |
400 | } |
401 | ||
9903cd1c CL |
402 | /** |
403 | * xprt_lookup_rqst - find an RPC request corresponding to an XID | |
404 | * @xprt: transport on which the original request was transmitted | |
405 | * @xid: RPC XID of incoming reply | |
406 | * | |
1da177e4 | 407 | */ |
a246b010 | 408 | struct rpc_rqst *xprt_lookup_rqst(struct rpc_xprt *xprt, u32 xid) |
1da177e4 LT |
409 | { |
410 | struct list_head *pos; | |
411 | struct rpc_rqst *req = NULL; | |
412 | ||
413 | list_for_each(pos, &xprt->recv) { | |
414 | struct rpc_rqst *entry = list_entry(pos, struct rpc_rqst, rq_list); | |
415 | if (entry->rq_xid == xid) { | |
416 | req = entry; | |
417 | break; | |
418 | } | |
419 | } | |
420 | return req; | |
421 | } | |
422 | ||
9903cd1c CL |
423 | /** |
424 | * xprt_complete_rqst - called when reply processing is complete | |
425 | * @xprt: controlling transport | |
426 | * @req: RPC request that just completed | |
427 | * @copied: actual number of bytes received from the transport | |
428 | * | |
1da177e4 | 429 | */ |
a246b010 | 430 | void xprt_complete_rqst(struct rpc_xprt *xprt, struct rpc_rqst *req, int copied) |
1da177e4 LT |
431 | { |
432 | struct rpc_task *task = req->rq_task; | |
433 | struct rpc_clnt *clnt = task->tk_client; | |
434 | ||
435 | /* Adjust congestion window */ | |
436 | if (!xprt->nocong) { | |
437 | unsigned timer = task->tk_msg.rpc_proc->p_timer; | |
438 | xprt_adjust_cwnd(xprt, copied); | |
439 | __xprt_put_cong(xprt, req); | |
440 | if (timer) { | |
441 | if (req->rq_ntrans == 1) | |
442 | rpc_update_rtt(clnt->cl_rtt, timer, | |
443 | (long)jiffies - req->rq_xtime); | |
444 | rpc_set_timeo(clnt->cl_rtt, timer, req->rq_ntrans - 1); | |
445 | } | |
446 | } | |
447 | ||
448 | #ifdef RPC_PROFILE | |
449 | /* Profile only reads for now */ | |
450 | if (copied > 1024) { | |
451 | static unsigned long nextstat; | |
452 | static unsigned long pkt_rtt, pkt_len, pkt_cnt; | |
453 | ||
454 | pkt_cnt++; | |
455 | pkt_len += req->rq_slen + copied; | |
456 | pkt_rtt += jiffies - req->rq_xtime; | |
457 | if (time_before(nextstat, jiffies)) { | |
458 | printk("RPC: %lu %ld cwnd\n", jiffies, xprt->cwnd); | |
459 | printk("RPC: %ld %ld %ld %ld stat\n", | |
460 | jiffies, pkt_cnt, pkt_len, pkt_rtt); | |
461 | pkt_rtt = pkt_len = pkt_cnt = 0; | |
462 | nextstat = jiffies + 5 * HZ; | |
463 | } | |
464 | } | |
465 | #endif | |
466 | ||
467 | dprintk("RPC: %4d has input (%d bytes)\n", task->tk_pid, copied); | |
468 | list_del_init(&req->rq_list); | |
469 | req->rq_received = req->rq_private_buf.len = copied; | |
470 | ||
471 | /* ... and wake up the process. */ | |
472 | rpc_wake_up_task(task); | |
473 | return; | |
474 | } | |
475 | ||
1da177e4 LT |
476 | /* |
477 | * RPC receive timeout handler. | |
478 | */ | |
479 | static void | |
480 | xprt_timer(struct rpc_task *task) | |
481 | { | |
482 | struct rpc_rqst *req = task->tk_rqstp; | |
483 | struct rpc_xprt *xprt = req->rq_xprt; | |
484 | ||
4a0f8c04 | 485 | spin_lock(&xprt->transport_lock); |
1da177e4 LT |
486 | if (req->rq_received) |
487 | goto out; | |
488 | ||
489 | xprt_adjust_cwnd(req->rq_xprt, -ETIMEDOUT); | |
490 | __xprt_put_cong(xprt, req); | |
491 | ||
492 | dprintk("RPC: %4d xprt_timer (%s request)\n", | |
493 | task->tk_pid, req ? "pending" : "backlogged"); | |
494 | ||
495 | task->tk_status = -ETIMEDOUT; | |
496 | out: | |
497 | task->tk_timeout = 0; | |
498 | rpc_wake_up_task(task); | |
4a0f8c04 | 499 | spin_unlock(&xprt->transport_lock); |
1da177e4 LT |
500 | } |
501 | ||
9903cd1c CL |
502 | /** |
503 | * xprt_prepare_transmit - reserve the transport before sending a request | |
504 | * @task: RPC task about to send a request | |
505 | * | |
1da177e4 | 506 | */ |
9903cd1c | 507 | int xprt_prepare_transmit(struct rpc_task *task) |
1da177e4 LT |
508 | { |
509 | struct rpc_rqst *req = task->tk_rqstp; | |
510 | struct rpc_xprt *xprt = req->rq_xprt; | |
511 | int err = 0; | |
512 | ||
513 | dprintk("RPC: %4d xprt_prepare_transmit\n", task->tk_pid); | |
514 | ||
515 | if (xprt->shutdown) | |
516 | return -EIO; | |
517 | ||
4a0f8c04 | 518 | spin_lock_bh(&xprt->transport_lock); |
1da177e4 LT |
519 | if (req->rq_received && !req->rq_bytes_sent) { |
520 | err = req->rq_received; | |
521 | goto out_unlock; | |
522 | } | |
523 | if (!__xprt_lock_write(xprt, task)) { | |
524 | err = -EAGAIN; | |
525 | goto out_unlock; | |
526 | } | |
527 | ||
528 | if (!xprt_connected(xprt)) { | |
529 | err = -ENOTCONN; | |
530 | goto out_unlock; | |
531 | } | |
532 | out_unlock: | |
4a0f8c04 | 533 | spin_unlock_bh(&xprt->transport_lock); |
1da177e4 LT |
534 | return err; |
535 | } | |
536 | ||
9903cd1c CL |
537 | /** |
538 | * xprt_transmit - send an RPC request on a transport | |
539 | * @task: controlling RPC task | |
540 | * | |
541 | * We have to copy the iovec because sendmsg fiddles with its contents. | |
542 | */ | |
543 | void xprt_transmit(struct rpc_task *task) | |
1da177e4 LT |
544 | { |
545 | struct rpc_clnt *clnt = task->tk_client; | |
546 | struct rpc_rqst *req = task->tk_rqstp; | |
547 | struct rpc_xprt *xprt = req->rq_xprt; | |
a246b010 | 548 | int status; |
1da177e4 LT |
549 | |
550 | dprintk("RPC: %4d xprt_transmit(%u)\n", task->tk_pid, req->rq_slen); | |
551 | ||
1da177e4 LT |
552 | smp_rmb(); |
553 | if (!req->rq_received) { | |
554 | if (list_empty(&req->rq_list)) { | |
4a0f8c04 | 555 | spin_lock_bh(&xprt->transport_lock); |
1da177e4 LT |
556 | /* Update the softirq receive buffer */ |
557 | memcpy(&req->rq_private_buf, &req->rq_rcv_buf, | |
558 | sizeof(req->rq_private_buf)); | |
559 | /* Add request to the receive list */ | |
560 | list_add_tail(&req->rq_list, &xprt->recv); | |
4a0f8c04 | 561 | spin_unlock_bh(&xprt->transport_lock); |
1da177e4 | 562 | xprt_reset_majortimeo(req); |
0f9dc2b1 TM |
563 | /* Turn off autodisconnect */ |
564 | del_singleshot_timer_sync(&xprt->timer); | |
1da177e4 LT |
565 | } |
566 | } else if (!req->rq_bytes_sent) | |
567 | return; | |
568 | ||
a246b010 CL |
569 | status = xprt->ops->send_request(task); |
570 | if (!status) | |
571 | goto out_receive; | |
1da177e4 LT |
572 | |
573 | /* Note: at this point, task->tk_sleeping has not yet been set, | |
574 | * hence there is no danger of the waking up task being put on | |
575 | * schedq, and being picked up by a parallel run of rpciod(). | |
576 | */ | |
577 | task->tk_status = status; | |
578 | ||
579 | switch (status) { | |
1da177e4 LT |
580 | case -ECONNREFUSED: |
581 | task->tk_timeout = RPC_REESTABLISH_TIMEOUT; | |
582 | rpc_sleep_on(&xprt->sending, task, NULL, NULL); | |
a246b010 | 583 | case -EAGAIN: |
1da177e4 LT |
584 | case -ENOTCONN: |
585 | return; | |
586 | default: | |
587 | if (xprt->stream) | |
588 | xprt_disconnect(xprt); | |
589 | } | |
590 | xprt_release_write(xprt, task); | |
591 | return; | |
592 | out_receive: | |
593 | dprintk("RPC: %4d xmit complete\n", task->tk_pid); | |
594 | /* Set the task's receive timeout value */ | |
4a0f8c04 | 595 | spin_lock_bh(&xprt->transport_lock); |
1da177e4 LT |
596 | if (!xprt->nocong) { |
597 | int timer = task->tk_msg.rpc_proc->p_timer; | |
598 | task->tk_timeout = rpc_calc_rto(clnt->cl_rtt, timer); | |
599 | task->tk_timeout <<= rpc_ntimeo(clnt->cl_rtt, timer) + req->rq_retries; | |
600 | if (task->tk_timeout > xprt->timeout.to_maxval || task->tk_timeout == 0) | |
601 | task->tk_timeout = xprt->timeout.to_maxval; | |
602 | } else | |
603 | task->tk_timeout = req->rq_timeout; | |
604 | /* Don't race with disconnect */ | |
605 | if (!xprt_connected(xprt)) | |
606 | task->tk_status = -ENOTCONN; | |
607 | else if (!req->rq_received) | |
608 | rpc_sleep_on(&xprt->pending, task, NULL, xprt_timer); | |
609 | __xprt_release_write(xprt, task); | |
4a0f8c04 | 610 | spin_unlock_bh(&xprt->transport_lock); |
1da177e4 LT |
611 | } |
612 | ||
9903cd1c | 613 | static inline void do_xprt_reserve(struct rpc_task *task) |
1da177e4 LT |
614 | { |
615 | struct rpc_xprt *xprt = task->tk_xprt; | |
616 | ||
617 | task->tk_status = 0; | |
618 | if (task->tk_rqstp) | |
619 | return; | |
620 | if (!list_empty(&xprt->free)) { | |
621 | struct rpc_rqst *req = list_entry(xprt->free.next, struct rpc_rqst, rq_list); | |
622 | list_del_init(&req->rq_list); | |
623 | task->tk_rqstp = req; | |
624 | xprt_request_init(task, xprt); | |
625 | return; | |
626 | } | |
627 | dprintk("RPC: waiting for request slot\n"); | |
628 | task->tk_status = -EAGAIN; | |
629 | task->tk_timeout = 0; | |
630 | rpc_sleep_on(&xprt->backlog, task, NULL, NULL); | |
631 | } | |
632 | ||
9903cd1c CL |
633 | /** |
634 | * xprt_reserve - allocate an RPC request slot | |
635 | * @task: RPC task requesting a slot allocation | |
636 | * | |
637 | * If no more slots are available, place the task on the transport's | |
638 | * backlog queue. | |
639 | */ | |
640 | void xprt_reserve(struct rpc_task *task) | |
1da177e4 LT |
641 | { |
642 | struct rpc_xprt *xprt = task->tk_xprt; | |
643 | ||
644 | task->tk_status = -EIO; | |
645 | if (!xprt->shutdown) { | |
646 | spin_lock(&xprt->xprt_lock); | |
647 | do_xprt_reserve(task); | |
648 | spin_unlock(&xprt->xprt_lock); | |
1da177e4 LT |
649 | } |
650 | } | |
651 | ||
1da177e4 LT |
652 | static inline u32 xprt_alloc_xid(struct rpc_xprt *xprt) |
653 | { | |
654 | return xprt->xid++; | |
655 | } | |
656 | ||
657 | static inline void xprt_init_xid(struct rpc_xprt *xprt) | |
658 | { | |
659 | get_random_bytes(&xprt->xid, sizeof(xprt->xid)); | |
660 | } | |
661 | ||
9903cd1c | 662 | static void xprt_request_init(struct rpc_task *task, struct rpc_xprt *xprt) |
1da177e4 LT |
663 | { |
664 | struct rpc_rqst *req = task->tk_rqstp; | |
665 | ||
666 | req->rq_timeout = xprt->timeout.to_initval; | |
667 | req->rq_task = task; | |
668 | req->rq_xprt = xprt; | |
669 | req->rq_xid = xprt_alloc_xid(xprt); | |
670 | dprintk("RPC: %4d reserved req %p xid %08x\n", task->tk_pid, | |
671 | req, ntohl(req->rq_xid)); | |
672 | } | |
673 | ||
9903cd1c CL |
674 | /** |
675 | * xprt_release - release an RPC request slot | |
676 | * @task: task which is finished with the slot | |
677 | * | |
1da177e4 | 678 | */ |
9903cd1c | 679 | void xprt_release(struct rpc_task *task) |
1da177e4 LT |
680 | { |
681 | struct rpc_xprt *xprt = task->tk_xprt; | |
682 | struct rpc_rqst *req; | |
683 | ||
684 | if (!(req = task->tk_rqstp)) | |
685 | return; | |
4a0f8c04 | 686 | spin_lock_bh(&xprt->transport_lock); |
1da177e4 LT |
687 | __xprt_release_write(xprt, task); |
688 | __xprt_put_cong(xprt, req); | |
689 | if (!list_empty(&req->rq_list)) | |
690 | list_del(&req->rq_list); | |
691 | xprt->last_used = jiffies; | |
692 | if (list_empty(&xprt->recv) && !xprt->shutdown) | |
a246b010 CL |
693 | mod_timer(&xprt->timer, |
694 | xprt->last_used + RPC_IDLE_DISCONNECT_TIMEOUT); | |
4a0f8c04 | 695 | spin_unlock_bh(&xprt->transport_lock); |
1da177e4 LT |
696 | task->tk_rqstp = NULL; |
697 | memset(req, 0, sizeof(*req)); /* mark unused */ | |
698 | ||
699 | dprintk("RPC: %4d release request %p\n", task->tk_pid, req); | |
700 | ||
701 | spin_lock(&xprt->xprt_lock); | |
702 | list_add(&req->rq_list, &xprt->free); | |
703 | xprt_clear_backlog(xprt); | |
704 | spin_unlock(&xprt->xprt_lock); | |
705 | } | |
706 | ||
9903cd1c CL |
707 | /** |
708 | * xprt_set_timeout - set constant RPC timeout | |
709 | * @to: RPC timeout parameters to set up | |
710 | * @retr: number of retries | |
711 | * @incr: amount of increase after each retry | |
712 | * | |
1da177e4 | 713 | */ |
9903cd1c | 714 | void xprt_set_timeout(struct rpc_timeout *to, unsigned int retr, unsigned long incr) |
1da177e4 LT |
715 | { |
716 | to->to_initval = | |
717 | to->to_increment = incr; | |
eab5c084 | 718 | to->to_maxval = to->to_initval + (incr * retr); |
1da177e4 LT |
719 | to->to_retries = retr; |
720 | to->to_exponential = 0; | |
721 | } | |
722 | ||
9903cd1c | 723 | static struct rpc_xprt *xprt_setup(int proto, struct sockaddr_in *ap, struct rpc_timeout *to) |
1da177e4 | 724 | { |
a246b010 | 725 | int result; |
1da177e4 | 726 | struct rpc_xprt *xprt; |
1da177e4 LT |
727 | struct rpc_rqst *req; |
728 | ||
1da177e4 LT |
729 | if ((xprt = kmalloc(sizeof(struct rpc_xprt), GFP_KERNEL)) == NULL) |
730 | return ERR_PTR(-ENOMEM); | |
731 | memset(xprt, 0, sizeof(*xprt)); /* Nnnngh! */ | |
1da177e4 LT |
732 | |
733 | xprt->addr = *ap; | |
a246b010 CL |
734 | |
735 | switch (proto) { | |
736 | case IPPROTO_UDP: | |
737 | result = xs_setup_udp(xprt, to); | |
738 | break; | |
739 | case IPPROTO_TCP: | |
740 | result = xs_setup_tcp(xprt, to); | |
741 | break; | |
742 | default: | |
743 | printk(KERN_ERR "RPC: unrecognized transport protocol: %d\n", | |
744 | proto); | |
745 | result = -EIO; | |
746 | break; | |
747 | } | |
748 | if (result) { | |
749 | kfree(xprt); | |
750 | return ERR_PTR(result); | |
1da177e4 | 751 | } |
a246b010 | 752 | |
4a0f8c04 | 753 | spin_lock_init(&xprt->transport_lock); |
1da177e4 LT |
754 | spin_lock_init(&xprt->xprt_lock); |
755 | init_waitqueue_head(&xprt->cong_wait); | |
756 | ||
757 | INIT_LIST_HEAD(&xprt->free); | |
758 | INIT_LIST_HEAD(&xprt->recv); | |
1da177e4 LT |
759 | INIT_WORK(&xprt->task_cleanup, xprt_socket_autoclose, xprt); |
760 | init_timer(&xprt->timer); | |
761 | xprt->timer.function = xprt_init_autodisconnect; | |
762 | xprt->timer.data = (unsigned long) xprt; | |
763 | xprt->last_used = jiffies; | |
1da177e4 LT |
764 | |
765 | rpc_init_wait_queue(&xprt->pending, "xprt_pending"); | |
766 | rpc_init_wait_queue(&xprt->sending, "xprt_sending"); | |
767 | rpc_init_wait_queue(&xprt->resend, "xprt_resend"); | |
768 | rpc_init_priority_wait_queue(&xprt->backlog, "xprt_backlog"); | |
769 | ||
770 | /* initialize free list */ | |
a246b010 | 771 | for (req = &xprt->slot[xprt->max_reqs-1]; req >= &xprt->slot[0]; req--) |
1da177e4 LT |
772 | list_add(&req->rq_list, &xprt->free); |
773 | ||
774 | xprt_init_xid(xprt); | |
775 | ||
1da177e4 LT |
776 | dprintk("RPC: created transport %p with %u slots\n", xprt, |
777 | xprt->max_reqs); | |
778 | ||
779 | return xprt; | |
780 | } | |
781 | ||
9903cd1c CL |
782 | /** |
783 | * xprt_create_proto - create an RPC client transport | |
784 | * @proto: requested transport protocol | |
785 | * @sap: remote peer's address | |
786 | * @to: timeout parameters for new transport | |
787 | * | |
1da177e4 | 788 | */ |
9903cd1c | 789 | struct rpc_xprt *xprt_create_proto(int proto, struct sockaddr_in *sap, struct rpc_timeout *to) |
1da177e4 LT |
790 | { |
791 | struct rpc_xprt *xprt; | |
792 | ||
793 | xprt = xprt_setup(proto, sap, to); | |
794 | if (IS_ERR(xprt)) | |
795 | dprintk("RPC: xprt_create_proto failed\n"); | |
796 | else | |
797 | dprintk("RPC: xprt_create_proto created xprt %p\n", xprt); | |
798 | return xprt; | |
799 | } | |
800 | ||
9903cd1c | 801 | static void xprt_shutdown(struct rpc_xprt *xprt) |
1da177e4 LT |
802 | { |
803 | xprt->shutdown = 1; | |
804 | rpc_wake_up(&xprt->sending); | |
805 | rpc_wake_up(&xprt->resend); | |
806 | rpc_wake_up(&xprt->pending); | |
807 | rpc_wake_up(&xprt->backlog); | |
808 | wake_up(&xprt->cong_wait); | |
809 | del_timer_sync(&xprt->timer); | |
810 | } | |
811 | ||
9903cd1c | 812 | static int xprt_clear_backlog(struct rpc_xprt *xprt) { |
1da177e4 LT |
813 | rpc_wake_up_next(&xprt->backlog); |
814 | wake_up(&xprt->cong_wait); | |
815 | return 1; | |
816 | } | |
817 | ||
9903cd1c CL |
818 | /** |
819 | * xprt_destroy - destroy an RPC transport, killing off all requests. | |
820 | * @xprt: transport to destroy | |
821 | * | |
1da177e4 | 822 | */ |
9903cd1c | 823 | int xprt_destroy(struct rpc_xprt *xprt) |
1da177e4 LT |
824 | { |
825 | dprintk("RPC: destroying transport %p\n", xprt); | |
826 | xprt_shutdown(xprt); | |
a246b010 | 827 | xprt->ops->destroy(xprt); |
1da177e4 LT |
828 | kfree(xprt); |
829 | ||
830 | return 0; | |
831 | } |