Commit | Line | Data |
---|---|---|
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 | |
55aa4f58 CL |
13 | * the request struct, and calls xprt_transmit(). |
14 | * - xprt_transmit sends the message and installs the caller on the | |
55ae1aab RL |
15 | * transport's wait list. At the same time, if a reply is expected, |
16 | * it installs a timer that is run after the packet's timeout has | |
17 | * expired. | |
1da177e4 | 18 | * - When a packet arrives, the data_ready handler walks the list of |
55aa4f58 | 19 | * pending requests for that transport. If a matching XID is found, the |
1da177e4 LT |
20 | * caller is woken up, and the timer removed. |
21 | * - When no reply arrives within the timeout interval, the timer is | |
22 | * fired by the kernel and runs xprt_timer(). It either adjusts the | |
23 | * timeout values (minor timeout) or wakes up the caller with a status | |
24 | * of -ETIMEDOUT. | |
25 | * - When the caller receives a notification from RPC that a reply arrived, | |
26 | * it should release the RPC slot, and process the reply. | |
27 | * If the call timed out, it may choose to retry the operation by | |
28 | * adjusting the initial timeout value, and simply calling rpc_call | |
29 | * again. | |
30 | * | |
31 | * Support for async RPC is done through a set of RPC-specific scheduling | |
32 | * primitives that `transparently' work for processes as well as async | |
33 | * tasks that rely on callbacks. | |
34 | * | |
35 | * Copyright (C) 1995-1997, Olaf Kirch <okir@monad.swb.de> | |
55aa4f58 CL |
36 | * |
37 | * Transport switch API copyright (C) 2005, Chuck Lever <cel@netapp.com> | |
1da177e4 LT |
38 | */ |
39 | ||
a246b010 CL |
40 | #include <linux/module.h> |
41 | ||
1da177e4 | 42 | #include <linux/types.h> |
a246b010 | 43 | #include <linux/interrupt.h> |
1da177e4 | 44 | #include <linux/workqueue.h> |
bf3fcf89 | 45 | #include <linux/net.h> |
ff839970 | 46 | #include <linux/ktime.h> |
1da177e4 | 47 | |
a246b010 | 48 | #include <linux/sunrpc/clnt.h> |
11c556b3 | 49 | #include <linux/sunrpc/metrics.h> |
c9acb42e | 50 | #include <linux/sunrpc/bc_xprt.h> |
1da177e4 | 51 | |
55ae1aab RL |
52 | #include "sunrpc.h" |
53 | ||
1da177e4 LT |
54 | /* |
55 | * Local variables | |
56 | */ | |
57 | ||
58 | #ifdef RPC_DEBUG | |
1da177e4 LT |
59 | # define RPCDBG_FACILITY RPCDBG_XPRT |
60 | #endif | |
61 | ||
1da177e4 LT |
62 | /* |
63 | * Local functions | |
64 | */ | |
21de0a95 | 65 | static void xprt_init(struct rpc_xprt *xprt, struct net *net); |
1da177e4 | 66 | static void xprt_request_init(struct rpc_task *, struct rpc_xprt *); |
1da177e4 | 67 | static void xprt_connect_status(struct rpc_task *task); |
1da177e4 LT |
68 | static int __xprt_get_cong(struct rpc_xprt *, struct rpc_task *); |
69 | ||
5ba03e82 | 70 | static DEFINE_SPINLOCK(xprt_list_lock); |
81c098af TT |
71 | static LIST_HEAD(xprt_list); |
72 | ||
555ee3af CL |
73 | /* |
74 | * The transport code maintains an estimate on the maximum number of out- | |
75 | * standing RPC requests, using a smoothed version of the congestion | |
76 | * avoidance implemented in 44BSD. This is basically the Van Jacobson | |
77 | * congestion algorithm: If a retransmit occurs, the congestion window is | |
78 | * halved; otherwise, it is incremented by 1/cwnd when | |
79 | * | |
80 | * - a reply is received and | |
81 | * - a full number of requests are outstanding and | |
82 | * - the congestion window hasn't been updated recently. | |
83 | */ | |
84 | #define RPC_CWNDSHIFT (8U) | |
85 | #define RPC_CWNDSCALE (1U << RPC_CWNDSHIFT) | |
86 | #define RPC_INITCWND RPC_CWNDSCALE | |
87 | #define RPC_MAXCWND(xprt) ((xprt)->max_reqs << RPC_CWNDSHIFT) | |
88 | ||
89 | #define RPCXPRT_CONGESTED(xprt) ((xprt)->cong >= (xprt)->cwnd) | |
1da177e4 | 90 | |
81c098af TT |
91 | /** |
92 | * xprt_register_transport - register a transport implementation | |
93 | * @transport: transport to register | |
94 | * | |
95 | * If a transport implementation is loaded as a kernel module, it can | |
96 | * call this interface to make itself known to the RPC client. | |
97 | * | |
98 | * Returns: | |
99 | * 0: transport successfully registered | |
100 | * -EEXIST: transport already registered | |
101 | * -EINVAL: transport module being unloaded | |
102 | */ | |
103 | int xprt_register_transport(struct xprt_class *transport) | |
104 | { | |
105 | struct xprt_class *t; | |
106 | int result; | |
107 | ||
108 | result = -EEXIST; | |
109 | spin_lock(&xprt_list_lock); | |
110 | list_for_each_entry(t, &xprt_list, list) { | |
111 | /* don't register the same transport class twice */ | |
4fa016eb | 112 | if (t->ident == transport->ident) |
81c098af TT |
113 | goto out; |
114 | } | |
115 | ||
c9f6cde6 DL |
116 | list_add_tail(&transport->list, &xprt_list); |
117 | printk(KERN_INFO "RPC: Registered %s transport module.\n", | |
118 | transport->name); | |
119 | result = 0; | |
81c098af TT |
120 | |
121 | out: | |
122 | spin_unlock(&xprt_list_lock); | |
123 | return result; | |
124 | } | |
125 | EXPORT_SYMBOL_GPL(xprt_register_transport); | |
126 | ||
127 | /** | |
128 | * xprt_unregister_transport - unregister a transport implementation | |
65b6e42c | 129 | * @transport: transport to unregister |
81c098af TT |
130 | * |
131 | * Returns: | |
132 | * 0: transport successfully unregistered | |
133 | * -ENOENT: transport never registered | |
134 | */ | |
135 | int xprt_unregister_transport(struct xprt_class *transport) | |
136 | { | |
137 | struct xprt_class *t; | |
138 | int result; | |
139 | ||
140 | result = 0; | |
141 | spin_lock(&xprt_list_lock); | |
142 | list_for_each_entry(t, &xprt_list, list) { | |
143 | if (t == transport) { | |
144 | printk(KERN_INFO | |
145 | "RPC: Unregistered %s transport module.\n", | |
146 | transport->name); | |
147 | list_del_init(&transport->list); | |
81c098af TT |
148 | goto out; |
149 | } | |
150 | } | |
151 | result = -ENOENT; | |
152 | ||
153 | out: | |
154 | spin_unlock(&xprt_list_lock); | |
155 | return result; | |
156 | } | |
157 | EXPORT_SYMBOL_GPL(xprt_unregister_transport); | |
158 | ||
441e3e24 TT |
159 | /** |
160 | * xprt_load_transport - load a transport implementation | |
161 | * @transport_name: transport to load | |
162 | * | |
163 | * Returns: | |
164 | * 0: transport successfully loaded | |
165 | * -ENOENT: transport module not available | |
166 | */ | |
167 | int xprt_load_transport(const char *transport_name) | |
168 | { | |
169 | struct xprt_class *t; | |
441e3e24 TT |
170 | int result; |
171 | ||
172 | result = 0; | |
173 | spin_lock(&xprt_list_lock); | |
174 | list_for_each_entry(t, &xprt_list, list) { | |
175 | if (strcmp(t->name, transport_name) == 0) { | |
176 | spin_unlock(&xprt_list_lock); | |
177 | goto out; | |
178 | } | |
179 | } | |
180 | spin_unlock(&xprt_list_lock); | |
ef7ffe8f | 181 | result = request_module("xprt%s", transport_name); |
441e3e24 TT |
182 | out: |
183 | return result; | |
184 | } | |
185 | EXPORT_SYMBOL_GPL(xprt_load_transport); | |
186 | ||
12a80469 CL |
187 | /** |
188 | * xprt_reserve_xprt - serialize write access to transports | |
189 | * @task: task that is requesting access to the transport | |
177c27bf | 190 | * @xprt: pointer to the target transport |
12a80469 CL |
191 | * |
192 | * This prevents mixing the payload of separate requests, and prevents | |
193 | * transport connects from colliding with writes. No congestion control | |
194 | * is provided. | |
195 | */ | |
43cedbf0 | 196 | int xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task) |
12a80469 | 197 | { |
12a80469 | 198 | struct rpc_rqst *req = task->tk_rqstp; |
34006cee | 199 | int priority; |
12a80469 CL |
200 | |
201 | if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) { | |
202 | if (task == xprt->snd_task) | |
203 | return 1; | |
12a80469 CL |
204 | goto out_sleep; |
205 | } | |
206 | xprt->snd_task = task; | |
43cedbf0 TM |
207 | if (req != NULL) { |
208 | req->rq_bytes_sent = 0; | |
209 | req->rq_ntrans++; | |
210 | } | |
4d4a76f3 | 211 | |
12a80469 CL |
212 | return 1; |
213 | ||
214 | out_sleep: | |
46121cf7 | 215 | dprintk("RPC: %5u failed to lock transport %p\n", |
12a80469 CL |
216 | task->tk_pid, xprt); |
217 | task->tk_timeout = 0; | |
218 | task->tk_status = -EAGAIN; | |
34006cee TM |
219 | if (req == NULL) |
220 | priority = RPC_PRIORITY_LOW; | |
221 | else if (!req->rq_ntrans) | |
222 | priority = RPC_PRIORITY_NORMAL; | |
12a80469 | 223 | else |
34006cee TM |
224 | priority = RPC_PRIORITY_HIGH; |
225 | rpc_sleep_on_priority(&xprt->sending, task, NULL, priority); | |
12a80469 CL |
226 | return 0; |
227 | } | |
12444809 | 228 | EXPORT_SYMBOL_GPL(xprt_reserve_xprt); |
12a80469 | 229 | |
632e3bdc TM |
230 | static void xprt_clear_locked(struct rpc_xprt *xprt) |
231 | { | |
232 | xprt->snd_task = NULL; | |
233 | if (!test_bit(XPRT_CLOSE_WAIT, &xprt->state) || xprt->shutdown) { | |
234 | smp_mb__before_clear_bit(); | |
235 | clear_bit(XPRT_LOCKED, &xprt->state); | |
236 | smp_mb__after_clear_bit(); | |
237 | } else | |
c1384c9c | 238 | queue_work(rpciod_workqueue, &xprt->task_cleanup); |
632e3bdc TM |
239 | } |
240 | ||
1da177e4 | 241 | /* |
12a80469 CL |
242 | * xprt_reserve_xprt_cong - serialize write access to transports |
243 | * @task: task that is requesting access to the transport | |
244 | * | |
245 | * Same as xprt_reserve_xprt, but Van Jacobson congestion control is | |
246 | * integrated into the decision of whether a request is allowed to be | |
247 | * woken up and given access to the transport. | |
1da177e4 | 248 | */ |
43cedbf0 | 249 | int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task) |
1da177e4 LT |
250 | { |
251 | struct rpc_rqst *req = task->tk_rqstp; | |
34006cee | 252 | int priority; |
1da177e4 | 253 | |
2226feb6 | 254 | if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) { |
1da177e4 LT |
255 | if (task == xprt->snd_task) |
256 | return 1; | |
1da177e4 LT |
257 | goto out_sleep; |
258 | } | |
43cedbf0 TM |
259 | if (req == NULL) { |
260 | xprt->snd_task = task; | |
261 | return 1; | |
262 | } | |
12a80469 | 263 | if (__xprt_get_cong(xprt, task)) { |
1da177e4 | 264 | xprt->snd_task = task; |
43cedbf0 TM |
265 | req->rq_bytes_sent = 0; |
266 | req->rq_ntrans++; | |
1da177e4 LT |
267 | return 1; |
268 | } | |
632e3bdc | 269 | xprt_clear_locked(xprt); |
1da177e4 | 270 | out_sleep: |
46121cf7 | 271 | dprintk("RPC: %5u failed to lock transport %p\n", task->tk_pid, xprt); |
1da177e4 LT |
272 | task->tk_timeout = 0; |
273 | task->tk_status = -EAGAIN; | |
34006cee TM |
274 | if (req == NULL) |
275 | priority = RPC_PRIORITY_LOW; | |
276 | else if (!req->rq_ntrans) | |
277 | priority = RPC_PRIORITY_NORMAL; | |
1da177e4 | 278 | else |
34006cee TM |
279 | priority = RPC_PRIORITY_HIGH; |
280 | rpc_sleep_on_priority(&xprt->sending, task, NULL, priority); | |
1da177e4 LT |
281 | return 0; |
282 | } | |
12444809 | 283 | EXPORT_SYMBOL_GPL(xprt_reserve_xprt_cong); |
1da177e4 | 284 | |
12a80469 | 285 | static inline int xprt_lock_write(struct rpc_xprt *xprt, struct rpc_task *task) |
1da177e4 LT |
286 | { |
287 | int retval; | |
288 | ||
4a0f8c04 | 289 | spin_lock_bh(&xprt->transport_lock); |
43cedbf0 | 290 | retval = xprt->ops->reserve_xprt(xprt, task); |
4a0f8c04 | 291 | spin_unlock_bh(&xprt->transport_lock); |
1da177e4 LT |
292 | return retval; |
293 | } | |
294 | ||
12a80469 | 295 | static void __xprt_lock_write_next(struct rpc_xprt *xprt) |
49e9a890 CL |
296 | { |
297 | struct rpc_task *task; | |
298 | struct rpc_rqst *req; | |
299 | ||
300 | if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) | |
301 | return; | |
302 | ||
34006cee TM |
303 | task = rpc_wake_up_next(&xprt->sending); |
304 | if (task == NULL) | |
305 | goto out_unlock; | |
49e9a890 CL |
306 | |
307 | req = task->tk_rqstp; | |
308 | xprt->snd_task = task; | |
309 | if (req) { | |
310 | req->rq_bytes_sent = 0; | |
311 | req->rq_ntrans++; | |
312 | } | |
313 | return; | |
314 | ||
315 | out_unlock: | |
632e3bdc | 316 | xprt_clear_locked(xprt); |
49e9a890 CL |
317 | } |
318 | ||
319 | static void __xprt_lock_write_next_cong(struct rpc_xprt *xprt) | |
1da177e4 LT |
320 | { |
321 | struct rpc_task *task; | |
43cedbf0 | 322 | struct rpc_rqst *req; |
1da177e4 | 323 | |
2226feb6 | 324 | if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) |
1da177e4 | 325 | return; |
49e9a890 | 326 | if (RPCXPRT_CONGESTED(xprt)) |
1da177e4 | 327 | goto out_unlock; |
34006cee TM |
328 | task = rpc_wake_up_next(&xprt->sending); |
329 | if (task == NULL) | |
330 | goto out_unlock; | |
43cedbf0 TM |
331 | |
332 | req = task->tk_rqstp; | |
333 | if (req == NULL) { | |
334 | xprt->snd_task = task; | |
335 | return; | |
336 | } | |
49e9a890 | 337 | if (__xprt_get_cong(xprt, task)) { |
1da177e4 | 338 | xprt->snd_task = task; |
43cedbf0 TM |
339 | req->rq_bytes_sent = 0; |
340 | req->rq_ntrans++; | |
1da177e4 LT |
341 | return; |
342 | } | |
343 | out_unlock: | |
632e3bdc | 344 | xprt_clear_locked(xprt); |
1da177e4 LT |
345 | } |
346 | ||
49e9a890 CL |
347 | /** |
348 | * xprt_release_xprt - allow other requests to use a transport | |
349 | * @xprt: transport with other tasks potentially waiting | |
350 | * @task: task that is releasing access to the transport | |
351 | * | |
352 | * Note that "task" can be NULL. No congestion control is provided. | |
1da177e4 | 353 | */ |
49e9a890 | 354 | void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task) |
1da177e4 LT |
355 | { |
356 | if (xprt->snd_task == task) { | |
632e3bdc | 357 | xprt_clear_locked(xprt); |
1da177e4 LT |
358 | __xprt_lock_write_next(xprt); |
359 | } | |
360 | } | |
12444809 | 361 | EXPORT_SYMBOL_GPL(xprt_release_xprt); |
1da177e4 | 362 | |
49e9a890 CL |
363 | /** |
364 | * xprt_release_xprt_cong - allow other requests to use a transport | |
365 | * @xprt: transport with other tasks potentially waiting | |
366 | * @task: task that is releasing access to the transport | |
367 | * | |
368 | * Note that "task" can be NULL. Another task is awoken to use the | |
369 | * transport if the transport's congestion window allows it. | |
370 | */ | |
371 | void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task) | |
372 | { | |
373 | if (xprt->snd_task == task) { | |
632e3bdc | 374 | xprt_clear_locked(xprt); |
49e9a890 CL |
375 | __xprt_lock_write_next_cong(xprt); |
376 | } | |
377 | } | |
12444809 | 378 | EXPORT_SYMBOL_GPL(xprt_release_xprt_cong); |
49e9a890 CL |
379 | |
380 | static inline void xprt_release_write(struct rpc_xprt *xprt, struct rpc_task *task) | |
1da177e4 | 381 | { |
4a0f8c04 | 382 | spin_lock_bh(&xprt->transport_lock); |
49e9a890 | 383 | xprt->ops->release_xprt(xprt, task); |
4a0f8c04 | 384 | spin_unlock_bh(&xprt->transport_lock); |
1da177e4 LT |
385 | } |
386 | ||
1da177e4 LT |
387 | /* |
388 | * Van Jacobson congestion avoidance. Check if the congestion window | |
389 | * overflowed. Put the task to sleep if this is the case. | |
390 | */ | |
391 | static int | |
392 | __xprt_get_cong(struct rpc_xprt *xprt, struct rpc_task *task) | |
393 | { | |
394 | struct rpc_rqst *req = task->tk_rqstp; | |
395 | ||
396 | if (req->rq_cong) | |
397 | return 1; | |
46121cf7 | 398 | dprintk("RPC: %5u xprt_cwnd_limited cong = %lu cwnd = %lu\n", |
1da177e4 LT |
399 | task->tk_pid, xprt->cong, xprt->cwnd); |
400 | if (RPCXPRT_CONGESTED(xprt)) | |
401 | return 0; | |
402 | req->rq_cong = 1; | |
403 | xprt->cong += RPC_CWNDSCALE; | |
404 | return 1; | |
405 | } | |
406 | ||
407 | /* | |
408 | * Adjust the congestion window, and wake up the next task | |
409 | * that has been sleeping due to congestion | |
410 | */ | |
411 | static void | |
412 | __xprt_put_cong(struct rpc_xprt *xprt, struct rpc_rqst *req) | |
413 | { | |
414 | if (!req->rq_cong) | |
415 | return; | |
416 | req->rq_cong = 0; | |
417 | xprt->cong -= RPC_CWNDSCALE; | |
49e9a890 | 418 | __xprt_lock_write_next_cong(xprt); |
1da177e4 LT |
419 | } |
420 | ||
a58dd398 CL |
421 | /** |
422 | * xprt_release_rqst_cong - housekeeping when request is complete | |
423 | * @task: RPC request that recently completed | |
424 | * | |
425 | * Useful for transports that require congestion control. | |
426 | */ | |
427 | void xprt_release_rqst_cong(struct rpc_task *task) | |
428 | { | |
429 | __xprt_put_cong(task->tk_xprt, task->tk_rqstp); | |
430 | } | |
12444809 | 431 | EXPORT_SYMBOL_GPL(xprt_release_rqst_cong); |
a58dd398 | 432 | |
46c0ee8b CL |
433 | /** |
434 | * xprt_adjust_cwnd - adjust transport congestion window | |
435 | * @task: recently completed RPC request used to adjust window | |
436 | * @result: result code of completed RPC request | |
437 | * | |
1da177e4 LT |
438 | * We use a time-smoothed congestion estimator to avoid heavy oscillation. |
439 | */ | |
46c0ee8b | 440 | void xprt_adjust_cwnd(struct rpc_task *task, int result) |
1da177e4 | 441 | { |
46c0ee8b CL |
442 | struct rpc_rqst *req = task->tk_rqstp; |
443 | struct rpc_xprt *xprt = task->tk_xprt; | |
444 | unsigned long cwnd = xprt->cwnd; | |
1da177e4 | 445 | |
1da177e4 LT |
446 | if (result >= 0 && cwnd <= xprt->cong) { |
447 | /* The (cwnd >> 1) term makes sure | |
448 | * the result gets rounded properly. */ | |
449 | cwnd += (RPC_CWNDSCALE * RPC_CWNDSCALE + (cwnd >> 1)) / cwnd; | |
450 | if (cwnd > RPC_MAXCWND(xprt)) | |
451 | cwnd = RPC_MAXCWND(xprt); | |
49e9a890 | 452 | __xprt_lock_write_next_cong(xprt); |
1da177e4 LT |
453 | } else if (result == -ETIMEDOUT) { |
454 | cwnd >>= 1; | |
455 | if (cwnd < RPC_CWNDSCALE) | |
456 | cwnd = RPC_CWNDSCALE; | |
457 | } | |
46121cf7 | 458 | dprintk("RPC: cong %ld, cwnd was %ld, now %ld\n", |
1da177e4 LT |
459 | xprt->cong, xprt->cwnd, cwnd); |
460 | xprt->cwnd = cwnd; | |
46c0ee8b | 461 | __xprt_put_cong(xprt, req); |
1da177e4 | 462 | } |
12444809 | 463 | EXPORT_SYMBOL_GPL(xprt_adjust_cwnd); |
1da177e4 | 464 | |
44fbac22 CL |
465 | /** |
466 | * xprt_wake_pending_tasks - wake all tasks on a transport's pending queue | |
467 | * @xprt: transport with waiting tasks | |
468 | * @status: result code to plant in each task before waking it | |
469 | * | |
470 | */ | |
471 | void xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status) | |
472 | { | |
473 | if (status < 0) | |
474 | rpc_wake_up_status(&xprt->pending, status); | |
475 | else | |
476 | rpc_wake_up(&xprt->pending); | |
477 | } | |
12444809 | 478 | EXPORT_SYMBOL_GPL(xprt_wake_pending_tasks); |
44fbac22 | 479 | |
c7b2cae8 CL |
480 | /** |
481 | * xprt_wait_for_buffer_space - wait for transport output buffer to clear | |
482 | * @task: task to be put to sleep | |
0b80ae42 | 483 | * @action: function pointer to be executed after wait |
c7b2cae8 | 484 | */ |
b6ddf64f | 485 | void xprt_wait_for_buffer_space(struct rpc_task *task, rpc_action action) |
c7b2cae8 CL |
486 | { |
487 | struct rpc_rqst *req = task->tk_rqstp; | |
488 | struct rpc_xprt *xprt = req->rq_xprt; | |
489 | ||
490 | task->tk_timeout = req->rq_timeout; | |
b6ddf64f | 491 | rpc_sleep_on(&xprt->pending, task, action); |
c7b2cae8 | 492 | } |
12444809 | 493 | EXPORT_SYMBOL_GPL(xprt_wait_for_buffer_space); |
c7b2cae8 CL |
494 | |
495 | /** | |
496 | * xprt_write_space - wake the task waiting for transport output buffer space | |
497 | * @xprt: transport with waiting tasks | |
498 | * | |
499 | * Can be called in a soft IRQ context, so xprt_write_space never sleeps. | |
500 | */ | |
501 | void xprt_write_space(struct rpc_xprt *xprt) | |
502 | { | |
503 | if (unlikely(xprt->shutdown)) | |
504 | return; | |
505 | ||
506 | spin_lock_bh(&xprt->transport_lock); | |
507 | if (xprt->snd_task) { | |
46121cf7 CL |
508 | dprintk("RPC: write space: waking waiting task on " |
509 | "xprt %p\n", xprt); | |
fda13939 | 510 | rpc_wake_up_queued_task(&xprt->pending, xprt->snd_task); |
c7b2cae8 CL |
511 | } |
512 | spin_unlock_bh(&xprt->transport_lock); | |
513 | } | |
12444809 | 514 | EXPORT_SYMBOL_GPL(xprt_write_space); |
c7b2cae8 | 515 | |
fe3aca29 CL |
516 | /** |
517 | * xprt_set_retrans_timeout_def - set a request's retransmit timeout | |
518 | * @task: task whose timeout is to be set | |
519 | * | |
520 | * Set a request's retransmit timeout based on the transport's | |
521 | * default timeout parameters. Used by transports that don't adjust | |
522 | * the retransmit timeout based on round-trip time estimation. | |
523 | */ | |
524 | void xprt_set_retrans_timeout_def(struct rpc_task *task) | |
525 | { | |
526 | task->tk_timeout = task->tk_rqstp->rq_timeout; | |
527 | } | |
12444809 | 528 | EXPORT_SYMBOL_GPL(xprt_set_retrans_timeout_def); |
fe3aca29 CL |
529 | |
530 | /* | |
531 | * xprt_set_retrans_timeout_rtt - set a request's retransmit timeout | |
532 | * @task: task whose timeout is to be set | |
cca5172a | 533 | * |
fe3aca29 CL |
534 | * Set a request's retransmit timeout using the RTT estimator. |
535 | */ | |
536 | void xprt_set_retrans_timeout_rtt(struct rpc_task *task) | |
537 | { | |
538 | int timer = task->tk_msg.rpc_proc->p_timer; | |
ba7392bb TM |
539 | struct rpc_clnt *clnt = task->tk_client; |
540 | struct rpc_rtt *rtt = clnt->cl_rtt; | |
fe3aca29 | 541 | struct rpc_rqst *req = task->tk_rqstp; |
ba7392bb | 542 | unsigned long max_timeout = clnt->cl_timeout->to_maxval; |
fe3aca29 CL |
543 | |
544 | task->tk_timeout = rpc_calc_rto(rtt, timer); | |
545 | task->tk_timeout <<= rpc_ntimeo(rtt, timer) + req->rq_retries; | |
546 | if (task->tk_timeout > max_timeout || task->tk_timeout == 0) | |
547 | task->tk_timeout = max_timeout; | |
548 | } | |
12444809 | 549 | EXPORT_SYMBOL_GPL(xprt_set_retrans_timeout_rtt); |
fe3aca29 | 550 | |
1da177e4 LT |
551 | static void xprt_reset_majortimeo(struct rpc_rqst *req) |
552 | { | |
ba7392bb | 553 | const struct rpc_timeout *to = req->rq_task->tk_client->cl_timeout; |
1da177e4 LT |
554 | |
555 | req->rq_majortimeo = req->rq_timeout; | |
556 | if (to->to_exponential) | |
557 | req->rq_majortimeo <<= to->to_retries; | |
558 | else | |
559 | req->rq_majortimeo += to->to_increment * to->to_retries; | |
560 | if (req->rq_majortimeo > to->to_maxval || req->rq_majortimeo == 0) | |
561 | req->rq_majortimeo = to->to_maxval; | |
562 | req->rq_majortimeo += jiffies; | |
563 | } | |
564 | ||
9903cd1c CL |
565 | /** |
566 | * xprt_adjust_timeout - adjust timeout values for next retransmit | |
567 | * @req: RPC request containing parameters to use for the adjustment | |
568 | * | |
1da177e4 LT |
569 | */ |
570 | int xprt_adjust_timeout(struct rpc_rqst *req) | |
571 | { | |
572 | struct rpc_xprt *xprt = req->rq_xprt; | |
ba7392bb | 573 | const struct rpc_timeout *to = req->rq_task->tk_client->cl_timeout; |
1da177e4 LT |
574 | int status = 0; |
575 | ||
576 | if (time_before(jiffies, req->rq_majortimeo)) { | |
577 | if (to->to_exponential) | |
578 | req->rq_timeout <<= 1; | |
579 | else | |
580 | req->rq_timeout += to->to_increment; | |
581 | if (to->to_maxval && req->rq_timeout >= to->to_maxval) | |
582 | req->rq_timeout = to->to_maxval; | |
583 | req->rq_retries++; | |
1da177e4 LT |
584 | } else { |
585 | req->rq_timeout = to->to_initval; | |
586 | req->rq_retries = 0; | |
587 | xprt_reset_majortimeo(req); | |
588 | /* Reset the RTT counters == "slow start" */ | |
4a0f8c04 | 589 | spin_lock_bh(&xprt->transport_lock); |
1da177e4 | 590 | rpc_init_rtt(req->rq_task->tk_client->cl_rtt, to->to_initval); |
4a0f8c04 | 591 | spin_unlock_bh(&xprt->transport_lock); |
1da177e4 LT |
592 | status = -ETIMEDOUT; |
593 | } | |
594 | ||
595 | if (req->rq_timeout == 0) { | |
596 | printk(KERN_WARNING "xprt_adjust_timeout: rq_timeout = 0!\n"); | |
597 | req->rq_timeout = 5 * HZ; | |
598 | } | |
599 | return status; | |
600 | } | |
601 | ||
65f27f38 | 602 | static void xprt_autoclose(struct work_struct *work) |
1da177e4 | 603 | { |
65f27f38 DH |
604 | struct rpc_xprt *xprt = |
605 | container_of(work, struct rpc_xprt, task_cleanup); | |
1da177e4 | 606 | |
a246b010 | 607 | xprt->ops->close(xprt); |
66af1e55 | 608 | clear_bit(XPRT_CLOSE_WAIT, &xprt->state); |
1da177e4 LT |
609 | xprt_release_write(xprt, NULL); |
610 | } | |
611 | ||
9903cd1c | 612 | /** |
62da3b24 | 613 | * xprt_disconnect_done - mark a transport as disconnected |
9903cd1c CL |
614 | * @xprt: transport to flag for disconnect |
615 | * | |
1da177e4 | 616 | */ |
62da3b24 | 617 | void xprt_disconnect_done(struct rpc_xprt *xprt) |
1da177e4 | 618 | { |
46121cf7 | 619 | dprintk("RPC: disconnected transport %p\n", xprt); |
4a0f8c04 | 620 | spin_lock_bh(&xprt->transport_lock); |
1da177e4 | 621 | xprt_clear_connected(xprt); |
2a491991 | 622 | xprt_wake_pending_tasks(xprt, -EAGAIN); |
4a0f8c04 | 623 | spin_unlock_bh(&xprt->transport_lock); |
1da177e4 | 624 | } |
62da3b24 | 625 | EXPORT_SYMBOL_GPL(xprt_disconnect_done); |
1da177e4 | 626 | |
66af1e55 TM |
627 | /** |
628 | * xprt_force_disconnect - force a transport to disconnect | |
629 | * @xprt: transport to disconnect | |
630 | * | |
631 | */ | |
632 | void xprt_force_disconnect(struct rpc_xprt *xprt) | |
633 | { | |
634 | /* Don't race with the test_bit() in xprt_clear_locked() */ | |
635 | spin_lock_bh(&xprt->transport_lock); | |
636 | set_bit(XPRT_CLOSE_WAIT, &xprt->state); | |
637 | /* Try to schedule an autoclose RPC call */ | |
638 | if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0) | |
639 | queue_work(rpciod_workqueue, &xprt->task_cleanup); | |
2a491991 | 640 | xprt_wake_pending_tasks(xprt, -EAGAIN); |
66af1e55 TM |
641 | spin_unlock_bh(&xprt->transport_lock); |
642 | } | |
66af1e55 | 643 | |
7c1d71cf TM |
644 | /** |
645 | * xprt_conditional_disconnect - force a transport to disconnect | |
646 | * @xprt: transport to disconnect | |
647 | * @cookie: 'connection cookie' | |
648 | * | |
649 | * This attempts to break the connection if and only if 'cookie' matches | |
650 | * the current transport 'connection cookie'. It ensures that we don't | |
651 | * try to break the connection more than once when we need to retransmit | |
652 | * a batch of RPC requests. | |
653 | * | |
654 | */ | |
655 | void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie) | |
656 | { | |
657 | /* Don't race with the test_bit() in xprt_clear_locked() */ | |
658 | spin_lock_bh(&xprt->transport_lock); | |
659 | if (cookie != xprt->connect_cookie) | |
660 | goto out; | |
661 | if (test_bit(XPRT_CLOSING, &xprt->state) || !xprt_connected(xprt)) | |
662 | goto out; | |
663 | set_bit(XPRT_CLOSE_WAIT, &xprt->state); | |
664 | /* Try to schedule an autoclose RPC call */ | |
665 | if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0) | |
666 | queue_work(rpciod_workqueue, &xprt->task_cleanup); | |
2a491991 | 667 | xprt_wake_pending_tasks(xprt, -EAGAIN); |
7c1d71cf TM |
668 | out: |
669 | spin_unlock_bh(&xprt->transport_lock); | |
670 | } | |
671 | ||
1da177e4 LT |
672 | static void |
673 | xprt_init_autodisconnect(unsigned long data) | |
674 | { | |
675 | struct rpc_xprt *xprt = (struct rpc_xprt *)data; | |
676 | ||
4a0f8c04 | 677 | spin_lock(&xprt->transport_lock); |
1da177e4 LT |
678 | if (!list_empty(&xprt->recv) || xprt->shutdown) |
679 | goto out_abort; | |
2226feb6 | 680 | if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) |
1da177e4 | 681 | goto out_abort; |
4a0f8c04 | 682 | spin_unlock(&xprt->transport_lock); |
f75e6745 TM |
683 | set_bit(XPRT_CONNECTION_CLOSE, &xprt->state); |
684 | queue_work(rpciod_workqueue, &xprt->task_cleanup); | |
1da177e4 LT |
685 | return; |
686 | out_abort: | |
4a0f8c04 | 687 | spin_unlock(&xprt->transport_lock); |
1da177e4 LT |
688 | } |
689 | ||
9903cd1c CL |
690 | /** |
691 | * xprt_connect - schedule a transport connect operation | |
692 | * @task: RPC task that is requesting the connect | |
1da177e4 LT |
693 | * |
694 | */ | |
695 | void xprt_connect(struct rpc_task *task) | |
696 | { | |
697 | struct rpc_xprt *xprt = task->tk_xprt; | |
698 | ||
46121cf7 | 699 | dprintk("RPC: %5u xprt_connect xprt %p %s connected\n", task->tk_pid, |
1da177e4 LT |
700 | xprt, (xprt_connected(xprt) ? "is" : "is not")); |
701 | ||
ec739ef0 | 702 | if (!xprt_bound(xprt)) { |
01d37c42 | 703 | task->tk_status = -EAGAIN; |
1da177e4 LT |
704 | return; |
705 | } | |
706 | if (!xprt_lock_write(xprt, task)) | |
707 | return; | |
feb8ca37 TM |
708 | |
709 | if (test_and_clear_bit(XPRT_CLOSE_WAIT, &xprt->state)) | |
710 | xprt->ops->close(xprt); | |
711 | ||
1da177e4 | 712 | if (xprt_connected(xprt)) |
a246b010 CL |
713 | xprt_release_write(xprt, task); |
714 | else { | |
715 | if (task->tk_rqstp) | |
716 | task->tk_rqstp->rq_bytes_sent = 0; | |
1da177e4 | 717 | |
a8ce4a8f | 718 | task->tk_timeout = task->tk_rqstp->rq_timeout; |
5d00837b | 719 | rpc_sleep_on(&xprt->pending, task, xprt_connect_status); |
0b9e7943 TM |
720 | |
721 | if (test_bit(XPRT_CLOSING, &xprt->state)) | |
722 | return; | |
723 | if (xprt_test_and_set_connecting(xprt)) | |
724 | return; | |
262ca07d | 725 | xprt->stat.connect_start = jiffies; |
a246b010 | 726 | xprt->ops->connect(task); |
1da177e4 | 727 | } |
1da177e4 LT |
728 | } |
729 | ||
9903cd1c | 730 | static void xprt_connect_status(struct rpc_task *task) |
1da177e4 LT |
731 | { |
732 | struct rpc_xprt *xprt = task->tk_xprt; | |
733 | ||
cd983ef8 | 734 | if (task->tk_status == 0) { |
262ca07d CL |
735 | xprt->stat.connect_count++; |
736 | xprt->stat.connect_time += (long)jiffies - xprt->stat.connect_start; | |
46121cf7 | 737 | dprintk("RPC: %5u xprt_connect_status: connection established\n", |
1da177e4 LT |
738 | task->tk_pid); |
739 | return; | |
740 | } | |
741 | ||
1da177e4 | 742 | switch (task->tk_status) { |
2a491991 TM |
743 | case -EAGAIN: |
744 | dprintk("RPC: %5u xprt_connect_status: retrying\n", task->tk_pid); | |
23475d66 | 745 | break; |
1da177e4 | 746 | case -ETIMEDOUT: |
46121cf7 CL |
747 | dprintk("RPC: %5u xprt_connect_status: connect attempt timed " |
748 | "out\n", task->tk_pid); | |
1da177e4 LT |
749 | break; |
750 | default: | |
46121cf7 CL |
751 | dprintk("RPC: %5u xprt_connect_status: error %d connecting to " |
752 | "server %s\n", task->tk_pid, -task->tk_status, | |
753 | task->tk_client->cl_server); | |
23475d66 CL |
754 | xprt_release_write(xprt, task); |
755 | task->tk_status = -EIO; | |
1da177e4 | 756 | } |
1da177e4 LT |
757 | } |
758 | ||
9903cd1c CL |
759 | /** |
760 | * xprt_lookup_rqst - find an RPC request corresponding to an XID | |
761 | * @xprt: transport on which the original request was transmitted | |
762 | * @xid: RPC XID of incoming reply | |
763 | * | |
1da177e4 | 764 | */ |
d8ed029d | 765 | struct rpc_rqst *xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid) |
1da177e4 | 766 | { |
8f3a6de3 | 767 | struct rpc_rqst *entry; |
1da177e4 | 768 | |
8f3a6de3 | 769 | list_for_each_entry(entry, &xprt->recv, rq_list) |
262ca07d CL |
770 | if (entry->rq_xid == xid) |
771 | return entry; | |
46121cf7 CL |
772 | |
773 | dprintk("RPC: xprt_lookup_rqst did not find xid %08x\n", | |
774 | ntohl(xid)); | |
262ca07d CL |
775 | xprt->stat.bad_xids++; |
776 | return NULL; | |
1da177e4 | 777 | } |
12444809 | 778 | EXPORT_SYMBOL_GPL(xprt_lookup_rqst); |
1da177e4 | 779 | |
bbc72cea | 780 | static void xprt_update_rtt(struct rpc_task *task) |
1570c1e4 CL |
781 | { |
782 | struct rpc_rqst *req = task->tk_rqstp; | |
783 | struct rpc_rtt *rtt = task->tk_client->cl_rtt; | |
784 | unsigned timer = task->tk_msg.rpc_proc->p_timer; | |
d60dbb20 | 785 | long m = usecs_to_jiffies(ktime_to_us(req->rq_rtt)); |
1570c1e4 CL |
786 | |
787 | if (timer) { | |
788 | if (req->rq_ntrans == 1) | |
ff839970 | 789 | rpc_update_rtt(rtt, timer, m); |
1570c1e4 CL |
790 | rpc_set_timeo(rtt, timer, req->rq_ntrans - 1); |
791 | } | |
792 | } | |
793 | ||
9903cd1c CL |
794 | /** |
795 | * xprt_complete_rqst - called when reply processing is complete | |
1570c1e4 | 796 | * @task: RPC request that recently completed |
9903cd1c CL |
797 | * @copied: actual number of bytes received from the transport |
798 | * | |
1570c1e4 | 799 | * Caller holds transport lock. |
1da177e4 | 800 | */ |
1570c1e4 | 801 | void xprt_complete_rqst(struct rpc_task *task, int copied) |
1da177e4 | 802 | { |
1570c1e4 | 803 | struct rpc_rqst *req = task->tk_rqstp; |
fda13939 | 804 | struct rpc_xprt *xprt = req->rq_xprt; |
1da177e4 | 805 | |
1570c1e4 CL |
806 | dprintk("RPC: %5u xid %08x complete (%d bytes received)\n", |
807 | task->tk_pid, ntohl(req->rq_xid), copied); | |
1da177e4 | 808 | |
fda13939 | 809 | xprt->stat.recvs++; |
d60dbb20 | 810 | req->rq_rtt = ktime_sub(ktime_get(), req->rq_xtime); |
bbc72cea CL |
811 | if (xprt->ops->timer != NULL) |
812 | xprt_update_rtt(task); | |
ef759a2e | 813 | |
1da177e4 | 814 | list_del_init(&req->rq_list); |
1e799b67 | 815 | req->rq_private_buf.len = copied; |
dd2b63d0 RL |
816 | /* Ensure all writes are done before we update */ |
817 | /* req->rq_reply_bytes_recvd */ | |
43ac3f29 | 818 | smp_wmb(); |
dd2b63d0 | 819 | req->rq_reply_bytes_recvd = copied; |
fda13939 | 820 | rpc_wake_up_queued_task(&xprt->pending, task); |
1da177e4 | 821 | } |
12444809 | 822 | EXPORT_SYMBOL_GPL(xprt_complete_rqst); |
1da177e4 | 823 | |
46c0ee8b | 824 | static void xprt_timer(struct rpc_task *task) |
1da177e4 | 825 | { |
46c0ee8b | 826 | struct rpc_rqst *req = task->tk_rqstp; |
1da177e4 LT |
827 | struct rpc_xprt *xprt = req->rq_xprt; |
828 | ||
5d00837b TM |
829 | if (task->tk_status != -ETIMEDOUT) |
830 | return; | |
46121cf7 | 831 | dprintk("RPC: %5u xprt_timer\n", task->tk_pid); |
1da177e4 | 832 | |
5d00837b | 833 | spin_lock_bh(&xprt->transport_lock); |
dd2b63d0 | 834 | if (!req->rq_reply_bytes_recvd) { |
46c0ee8b CL |
835 | if (xprt->ops->timer) |
836 | xprt->ops->timer(task); | |
5d00837b TM |
837 | } else |
838 | task->tk_status = 0; | |
839 | spin_unlock_bh(&xprt->transport_lock); | |
1da177e4 LT |
840 | } |
841 | ||
4cfc7e60 RI |
842 | static inline int xprt_has_timer(struct rpc_xprt *xprt) |
843 | { | |
844 | return xprt->idle_timeout != 0; | |
845 | } | |
846 | ||
9903cd1c CL |
847 | /** |
848 | * xprt_prepare_transmit - reserve the transport before sending a request | |
849 | * @task: RPC task about to send a request | |
850 | * | |
1da177e4 | 851 | */ |
9903cd1c | 852 | int xprt_prepare_transmit(struct rpc_task *task) |
1da177e4 LT |
853 | { |
854 | struct rpc_rqst *req = task->tk_rqstp; | |
855 | struct rpc_xprt *xprt = req->rq_xprt; | |
856 | int err = 0; | |
857 | ||
46121cf7 | 858 | dprintk("RPC: %5u xprt_prepare_transmit\n", task->tk_pid); |
1da177e4 | 859 | |
4a0f8c04 | 860 | spin_lock_bh(&xprt->transport_lock); |
dd2b63d0 RL |
861 | if (req->rq_reply_bytes_recvd && !req->rq_bytes_sent) { |
862 | err = req->rq_reply_bytes_recvd; | |
1da177e4 LT |
863 | goto out_unlock; |
864 | } | |
43cedbf0 | 865 | if (!xprt->ops->reserve_xprt(xprt, task)) |
1da177e4 | 866 | err = -EAGAIN; |
1da177e4 | 867 | out_unlock: |
4a0f8c04 | 868 | spin_unlock_bh(&xprt->transport_lock); |
1da177e4 LT |
869 | return err; |
870 | } | |
871 | ||
e0ab53de | 872 | void xprt_end_transmit(struct rpc_task *task) |
5e5ce5be | 873 | { |
343952fa | 874 | xprt_release_write(task->tk_rqstp->rq_xprt, task); |
5e5ce5be TM |
875 | } |
876 | ||
9903cd1c CL |
877 | /** |
878 | * xprt_transmit - send an RPC request on a transport | |
879 | * @task: controlling RPC task | |
880 | * | |
881 | * We have to copy the iovec because sendmsg fiddles with its contents. | |
882 | */ | |
883 | void xprt_transmit(struct rpc_task *task) | |
1da177e4 | 884 | { |
1da177e4 LT |
885 | struct rpc_rqst *req = task->tk_rqstp; |
886 | struct rpc_xprt *xprt = req->rq_xprt; | |
a246b010 | 887 | int status; |
1da177e4 | 888 | |
46121cf7 | 889 | dprintk("RPC: %5u xprt_transmit(%u)\n", task->tk_pid, req->rq_slen); |
1da177e4 | 890 | |
dd2b63d0 | 891 | if (!req->rq_reply_bytes_recvd) { |
55ae1aab RL |
892 | if (list_empty(&req->rq_list) && rpc_reply_expected(task)) { |
893 | /* | |
894 | * Add to the list only if we're expecting a reply | |
895 | */ | |
4a0f8c04 | 896 | spin_lock_bh(&xprt->transport_lock); |
1da177e4 LT |
897 | /* Update the softirq receive buffer */ |
898 | memcpy(&req->rq_private_buf, &req->rq_rcv_buf, | |
899 | sizeof(req->rq_private_buf)); | |
900 | /* Add request to the receive list */ | |
901 | list_add_tail(&req->rq_list, &xprt->recv); | |
4a0f8c04 | 902 | spin_unlock_bh(&xprt->transport_lock); |
1da177e4 | 903 | xprt_reset_majortimeo(req); |
0f9dc2b1 TM |
904 | /* Turn off autodisconnect */ |
905 | del_singleshot_timer_sync(&xprt->timer); | |
1da177e4 LT |
906 | } |
907 | } else if (!req->rq_bytes_sent) | |
908 | return; | |
909 | ||
7c1d71cf | 910 | req->rq_connect_cookie = xprt->connect_cookie; |
ff839970 | 911 | req->rq_xtime = ktime_get(); |
a246b010 | 912 | status = xprt->ops->send_request(task); |
c8485e4d TM |
913 | if (status != 0) { |
914 | task->tk_status = status; | |
915 | return; | |
916 | } | |
262ca07d | 917 | |
c8485e4d | 918 | dprintk("RPC: %5u xmit complete\n", task->tk_pid); |
468f8613 | 919 | task->tk_flags |= RPC_TASK_SENT; |
c8485e4d | 920 | spin_lock_bh(&xprt->transport_lock); |
262ca07d | 921 | |
c8485e4d | 922 | xprt->ops->set_retrans_timeout(task); |
262ca07d | 923 | |
c8485e4d TM |
924 | xprt->stat.sends++; |
925 | xprt->stat.req_u += xprt->stat.sends - xprt->stat.recvs; | |
926 | xprt->stat.bklog_u += xprt->backlog.qlen; | |
1da177e4 | 927 | |
c8485e4d TM |
928 | /* Don't race with disconnect */ |
929 | if (!xprt_connected(xprt)) | |
930 | task->tk_status = -ENOTCONN; | |
dd2b63d0 | 931 | else if (!req->rq_reply_bytes_recvd && rpc_reply_expected(task)) { |
55ae1aab RL |
932 | /* |
933 | * Sleep on the pending queue since | |
934 | * we're expecting a reply. | |
935 | */ | |
c8485e4d | 936 | rpc_sleep_on(&xprt->pending, task, xprt_timer); |
55ae1aab | 937 | } |
c8485e4d | 938 | spin_unlock_bh(&xprt->transport_lock); |
1da177e4 LT |
939 | } |
940 | ||
d9ba131d TM |
941 | static struct rpc_rqst *xprt_dynamic_alloc_slot(struct rpc_xprt *xprt, gfp_t gfp_flags) |
942 | { | |
943 | struct rpc_rqst *req = ERR_PTR(-EAGAIN); | |
944 | ||
945 | if (!atomic_add_unless(&xprt->num_reqs, 1, xprt->max_reqs)) | |
946 | goto out; | |
947 | req = kzalloc(sizeof(struct rpc_rqst), gfp_flags); | |
948 | if (req != NULL) | |
949 | goto out; | |
950 | atomic_dec(&xprt->num_reqs); | |
951 | req = ERR_PTR(-ENOMEM); | |
952 | out: | |
953 | return req; | |
954 | } | |
955 | ||
956 | static bool xprt_dynamic_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *req) | |
957 | { | |
958 | if (atomic_add_unless(&xprt->num_reqs, -1, xprt->min_reqs)) { | |
959 | kfree(req); | |
960 | return true; | |
961 | } | |
962 | return false; | |
963 | } | |
964 | ||
ee5ebe85 | 965 | static void xprt_alloc_slot(struct rpc_task *task) |
1da177e4 LT |
966 | { |
967 | struct rpc_xprt *xprt = task->tk_xprt; | |
d9ba131d | 968 | struct rpc_rqst *req; |
1da177e4 | 969 | |
1da177e4 | 970 | if (!list_empty(&xprt->free)) { |
d9ba131d TM |
971 | req = list_entry(xprt->free.next, struct rpc_rqst, rq_list); |
972 | list_del(&req->rq_list); | |
973 | goto out_init_req; | |
974 | } | |
975 | req = xprt_dynamic_alloc_slot(xprt, GFP_NOWAIT); | |
976 | if (!IS_ERR(req)) | |
977 | goto out_init_req; | |
978 | switch (PTR_ERR(req)) { | |
979 | case -ENOMEM: | |
980 | rpc_delay(task, HZ >> 2); | |
981 | dprintk("RPC: dynamic allocation of request slot " | |
982 | "failed! Retrying\n"); | |
983 | break; | |
984 | case -EAGAIN: | |
985 | rpc_sleep_on(&xprt->backlog, task, NULL); | |
986 | dprintk("RPC: waiting for request slot\n"); | |
1da177e4 | 987 | } |
1da177e4 | 988 | task->tk_status = -EAGAIN; |
d9ba131d TM |
989 | return; |
990 | out_init_req: | |
991 | task->tk_status = 0; | |
992 | task->tk_rqstp = req; | |
993 | xprt_request_init(task, xprt); | |
1da177e4 LT |
994 | } |
995 | ||
ee5ebe85 TM |
996 | static void xprt_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *req) |
997 | { | |
ee5ebe85 | 998 | spin_lock(&xprt->reserve_lock); |
c25573b5 TM |
999 | if (!xprt_dynamic_free_slot(xprt, req)) { |
1000 | memset(req, 0, sizeof(*req)); /* mark unused */ | |
1001 | list_add(&req->rq_list, &xprt->free); | |
1002 | } | |
ee5ebe85 TM |
1003 | rpc_wake_up_next(&xprt->backlog); |
1004 | spin_unlock(&xprt->reserve_lock); | |
1005 | } | |
1006 | ||
21de0a95 TM |
1007 | static void xprt_free_all_slots(struct rpc_xprt *xprt) |
1008 | { | |
1009 | struct rpc_rqst *req; | |
1010 | while (!list_empty(&xprt->free)) { | |
1011 | req = list_first_entry(&xprt->free, struct rpc_rqst, rq_list); | |
1012 | list_del(&req->rq_list); | |
1013 | kfree(req); | |
1014 | } | |
1015 | } | |
1016 | ||
d9ba131d TM |
1017 | struct rpc_xprt *xprt_alloc(struct net *net, size_t size, |
1018 | unsigned int num_prealloc, | |
1019 | unsigned int max_alloc) | |
bd1722d4 PE |
1020 | { |
1021 | struct rpc_xprt *xprt; | |
21de0a95 TM |
1022 | struct rpc_rqst *req; |
1023 | int i; | |
bd1722d4 PE |
1024 | |
1025 | xprt = kzalloc(size, GFP_KERNEL); | |
1026 | if (xprt == NULL) | |
1027 | goto out; | |
1028 | ||
21de0a95 TM |
1029 | xprt_init(xprt, net); |
1030 | ||
1031 | for (i = 0; i < num_prealloc; i++) { | |
1032 | req = kzalloc(sizeof(struct rpc_rqst), GFP_KERNEL); | |
1033 | if (!req) | |
1034 | break; | |
1035 | list_add(&req->rq_list, &xprt->free); | |
1036 | } | |
1037 | if (i < num_prealloc) | |
bd1722d4 | 1038 | goto out_free; |
d9ba131d TM |
1039 | if (max_alloc > num_prealloc) |
1040 | xprt->max_reqs = max_alloc; | |
1041 | else | |
1042 | xprt->max_reqs = num_prealloc; | |
1043 | xprt->min_reqs = num_prealloc; | |
1044 | atomic_set(&xprt->num_reqs, num_prealloc); | |
bd1722d4 PE |
1045 | |
1046 | return xprt; | |
1047 | ||
1048 | out_free: | |
21de0a95 | 1049 | xprt_free(xprt); |
bd1722d4 PE |
1050 | out: |
1051 | return NULL; | |
1052 | } | |
1053 | EXPORT_SYMBOL_GPL(xprt_alloc); | |
1054 | ||
e204e621 PE |
1055 | void xprt_free(struct rpc_xprt *xprt) |
1056 | { | |
37aa2133 | 1057 | put_net(xprt->xprt_net); |
21de0a95 | 1058 | xprt_free_all_slots(xprt); |
e204e621 PE |
1059 | kfree(xprt); |
1060 | } | |
1061 | EXPORT_SYMBOL_GPL(xprt_free); | |
1062 | ||
9903cd1c CL |
1063 | /** |
1064 | * xprt_reserve - allocate an RPC request slot | |
1065 | * @task: RPC task requesting a slot allocation | |
1066 | * | |
1067 | * If no more slots are available, place the task on the transport's | |
1068 | * backlog queue. | |
1069 | */ | |
1070 | void xprt_reserve(struct rpc_task *task) | |
1da177e4 LT |
1071 | { |
1072 | struct rpc_xprt *xprt = task->tk_xprt; | |
1073 | ||
43cedbf0 TM |
1074 | task->tk_status = 0; |
1075 | if (task->tk_rqstp != NULL) | |
1076 | return; | |
1077 | ||
1078 | /* Note: grabbing the xprt_lock_write() here is not strictly needed, | |
1079 | * but ensures that we throttle new slot allocation if the transport | |
1080 | * is congested (e.g. if reconnecting or if we're out of socket | |
1081 | * write buffer space). | |
1082 | */ | |
1083 | task->tk_timeout = 0; | |
1084 | task->tk_status = -EAGAIN; | |
1085 | if (!xprt_lock_write(xprt, task)) | |
1086 | return; | |
1087 | ||
0065db32 | 1088 | spin_lock(&xprt->reserve_lock); |
ee5ebe85 | 1089 | xprt_alloc_slot(task); |
0065db32 | 1090 | spin_unlock(&xprt->reserve_lock); |
43cedbf0 | 1091 | xprt_release_write(xprt, task); |
1da177e4 LT |
1092 | } |
1093 | ||
d8ed029d | 1094 | static inline __be32 xprt_alloc_xid(struct rpc_xprt *xprt) |
1da177e4 | 1095 | { |
0eae88f3 | 1096 | return (__force __be32)xprt->xid++; |
1da177e4 LT |
1097 | } |
1098 | ||
1099 | static inline void xprt_init_xid(struct rpc_xprt *xprt) | |
1100 | { | |
bf3fcf89 | 1101 | xprt->xid = net_random(); |
1da177e4 LT |
1102 | } |
1103 | ||
9903cd1c | 1104 | static void xprt_request_init(struct rpc_task *task, struct rpc_xprt *xprt) |
1da177e4 LT |
1105 | { |
1106 | struct rpc_rqst *req = task->tk_rqstp; | |
1107 | ||
d9ba131d | 1108 | INIT_LIST_HEAD(&req->rq_list); |
ba7392bb | 1109 | req->rq_timeout = task->tk_client->cl_timeout->to_initval; |
1da177e4 LT |
1110 | req->rq_task = task; |
1111 | req->rq_xprt = xprt; | |
02107148 | 1112 | req->rq_buffer = NULL; |
1da177e4 | 1113 | req->rq_xid = xprt_alloc_xid(xprt); |
ead5e1c2 | 1114 | req->rq_release_snd_buf = NULL; |
da45828e | 1115 | xprt_reset_majortimeo(req); |
46121cf7 | 1116 | dprintk("RPC: %5u reserved req %p xid %08x\n", task->tk_pid, |
1da177e4 LT |
1117 | req, ntohl(req->rq_xid)); |
1118 | } | |
1119 | ||
9903cd1c CL |
1120 | /** |
1121 | * xprt_release - release an RPC request slot | |
1122 | * @task: task which is finished with the slot | |
1123 | * | |
1da177e4 | 1124 | */ |
9903cd1c | 1125 | void xprt_release(struct rpc_task *task) |
1da177e4 | 1126 | { |
55ae1aab | 1127 | struct rpc_xprt *xprt; |
1da177e4 LT |
1128 | struct rpc_rqst *req; |
1129 | ||
1130 | if (!(req = task->tk_rqstp)) | |
1131 | return; | |
55ae1aab | 1132 | |
55ae1aab | 1133 | xprt = req->rq_xprt; |
11c556b3 | 1134 | rpc_count_iostats(task); |
4a0f8c04 | 1135 | spin_lock_bh(&xprt->transport_lock); |
49e9a890 | 1136 | xprt->ops->release_xprt(xprt, task); |
a58dd398 CL |
1137 | if (xprt->ops->release_request) |
1138 | xprt->ops->release_request(task); | |
1da177e4 LT |
1139 | if (!list_empty(&req->rq_list)) |
1140 | list_del(&req->rq_list); | |
1141 | xprt->last_used = jiffies; | |
4cfc7e60 | 1142 | if (list_empty(&xprt->recv) && xprt_has_timer(xprt)) |
a246b010 | 1143 | mod_timer(&xprt->timer, |
03bf4b70 | 1144 | xprt->last_used + xprt->idle_timeout); |
4a0f8c04 | 1145 | spin_unlock_bh(&xprt->transport_lock); |
ee5ebe85 | 1146 | if (req->rq_buffer) |
55ae1aab | 1147 | xprt->ops->buf_free(req->rq_buffer); |
a17c2153 TM |
1148 | if (req->rq_cred != NULL) |
1149 | put_rpccred(req->rq_cred); | |
1da177e4 | 1150 | task->tk_rqstp = NULL; |
ead5e1c2 BF |
1151 | if (req->rq_release_snd_buf) |
1152 | req->rq_release_snd_buf(req); | |
55ae1aab | 1153 | |
46121cf7 | 1154 | dprintk("RPC: %5u release request %p\n", task->tk_pid, req); |
ee5ebe85 TM |
1155 | if (likely(!bc_prealloc(req))) |
1156 | xprt_free_slot(xprt, req); | |
1157 | else | |
c9acb42e | 1158 | xprt_free_bc_request(req); |
1da177e4 LT |
1159 | } |
1160 | ||
21de0a95 | 1161 | static void xprt_init(struct rpc_xprt *xprt, struct net *net) |
c2866763 | 1162 | { |
21de0a95 | 1163 | atomic_set(&xprt->count, 1); |
c2866763 CL |
1164 | |
1165 | spin_lock_init(&xprt->transport_lock); | |
1166 | spin_lock_init(&xprt->reserve_lock); | |
1167 | ||
1168 | INIT_LIST_HEAD(&xprt->free); | |
1169 | INIT_LIST_HEAD(&xprt->recv); | |
9e00abc3 | 1170 | #if defined(CONFIG_SUNRPC_BACKCHANNEL) |
f9acac1a RL |
1171 | spin_lock_init(&xprt->bc_pa_lock); |
1172 | INIT_LIST_HEAD(&xprt->bc_pa_list); | |
9e00abc3 | 1173 | #endif /* CONFIG_SUNRPC_BACKCHANNEL */ |
f9acac1a | 1174 | |
c2866763 CL |
1175 | xprt->last_used = jiffies; |
1176 | xprt->cwnd = RPC_INITCWND; | |
a509050b | 1177 | xprt->bind_index = 0; |
c2866763 CL |
1178 | |
1179 | rpc_init_wait_queue(&xprt->binding, "xprt_binding"); | |
1180 | rpc_init_wait_queue(&xprt->pending, "xprt_pending"); | |
34006cee | 1181 | rpc_init_priority_wait_queue(&xprt->sending, "xprt_sending"); |
c2866763 CL |
1182 | rpc_init_priority_wait_queue(&xprt->backlog, "xprt_backlog"); |
1183 | ||
c2866763 CL |
1184 | xprt_init_xid(xprt); |
1185 | ||
21de0a95 | 1186 | xprt->xprt_net = get_net(net); |
8d9266ff TM |
1187 | } |
1188 | ||
1189 | /** | |
1190 | * xprt_create_transport - create an RPC transport | |
1191 | * @args: rpc transport creation arguments | |
1192 | * | |
1193 | */ | |
1194 | struct rpc_xprt *xprt_create_transport(struct xprt_create *args) | |
1195 | { | |
1196 | struct rpc_xprt *xprt; | |
1197 | struct xprt_class *t; | |
1198 | ||
1199 | spin_lock(&xprt_list_lock); | |
1200 | list_for_each_entry(t, &xprt_list, list) { | |
1201 | if (t->ident == args->ident) { | |
1202 | spin_unlock(&xprt_list_lock); | |
1203 | goto found; | |
1204 | } | |
1205 | } | |
1206 | spin_unlock(&xprt_list_lock); | |
1207 | printk(KERN_ERR "RPC: transport (%d) not supported\n", args->ident); | |
1208 | return ERR_PTR(-EIO); | |
1209 | ||
1210 | found: | |
1211 | xprt = t->setup(args); | |
1212 | if (IS_ERR(xprt)) { | |
1213 | dprintk("RPC: xprt_create_transport: failed, %ld\n", | |
1214 | -PTR_ERR(xprt)); | |
21de0a95 | 1215 | goto out; |
8d9266ff | 1216 | } |
21de0a95 TM |
1217 | INIT_WORK(&xprt->task_cleanup, xprt_autoclose); |
1218 | if (xprt_has_timer(xprt)) | |
1219 | setup_timer(&xprt->timer, xprt_init_autodisconnect, | |
1220 | (unsigned long)xprt); | |
1221 | else | |
1222 | init_timer(&xprt->timer); | |
46121cf7 | 1223 | dprintk("RPC: created transport %p with %u slots\n", xprt, |
c2866763 | 1224 | xprt->max_reqs); |
21de0a95 | 1225 | out: |
c2866763 CL |
1226 | return xprt; |
1227 | } | |
1228 | ||
9903cd1c CL |
1229 | /** |
1230 | * xprt_destroy - destroy an RPC transport, killing off all requests. | |
a8de240a | 1231 | * @xprt: transport to destroy |
9903cd1c | 1232 | * |
1da177e4 | 1233 | */ |
a8de240a | 1234 | static void xprt_destroy(struct rpc_xprt *xprt) |
1da177e4 | 1235 | { |
46121cf7 | 1236 | dprintk("RPC: destroying transport %p\n", xprt); |
0065db32 TM |
1237 | xprt->shutdown = 1; |
1238 | del_timer_sync(&xprt->timer); | |
c8541ecd | 1239 | |
f6a1cc89 TM |
1240 | rpc_destroy_wait_queue(&xprt->binding); |
1241 | rpc_destroy_wait_queue(&xprt->pending); | |
1242 | rpc_destroy_wait_queue(&xprt->sending); | |
f6a1cc89 | 1243 | rpc_destroy_wait_queue(&xprt->backlog); |
c3ae62ae | 1244 | cancel_work_sync(&xprt->task_cleanup); |
c8541ecd CL |
1245 | /* |
1246 | * Tear down transport state and free the rpc_xprt | |
1247 | */ | |
a246b010 | 1248 | xprt->ops->destroy(xprt); |
6b6ca86b | 1249 | } |
1da177e4 | 1250 | |
6b6ca86b TM |
1251 | /** |
1252 | * xprt_put - release a reference to an RPC transport. | |
1253 | * @xprt: pointer to the transport | |
1254 | * | |
1255 | */ | |
1256 | void xprt_put(struct rpc_xprt *xprt) | |
1257 | { | |
a8de240a TM |
1258 | if (atomic_dec_and_test(&xprt->count)) |
1259 | xprt_destroy(xprt); | |
6b6ca86b TM |
1260 | } |
1261 | ||
1262 | /** | |
1263 | * xprt_get - return a reference to an RPC transport. | |
1264 | * @xprt: pointer to the transport | |
1265 | * | |
1266 | */ | |
1267 | struct rpc_xprt *xprt_get(struct rpc_xprt *xprt) | |
1268 | { | |
a8de240a TM |
1269 | if (atomic_inc_not_zero(&xprt->count)) |
1270 | return xprt; | |
1271 | return NULL; | |
1da177e4 | 1272 | } |