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 | 68 | static int __xprt_get_cong(struct rpc_xprt *, struct rpc_task *); |
4e0038b6 | 69 | static void xprt_destroy(struct rpc_xprt *xprt); |
1da177e4 | 70 | |
5ba03e82 | 71 | static DEFINE_SPINLOCK(xprt_list_lock); |
81c098af TT |
72 | static LIST_HEAD(xprt_list); |
73 | ||
555ee3af CL |
74 | /* |
75 | * The transport code maintains an estimate on the maximum number of out- | |
76 | * standing RPC requests, using a smoothed version of the congestion | |
77 | * avoidance implemented in 44BSD. This is basically the Van Jacobson | |
78 | * congestion algorithm: If a retransmit occurs, the congestion window is | |
79 | * halved; otherwise, it is incremented by 1/cwnd when | |
80 | * | |
81 | * - a reply is received and | |
82 | * - a full number of requests are outstanding and | |
83 | * - the congestion window hasn't been updated recently. | |
84 | */ | |
85 | #define RPC_CWNDSHIFT (8U) | |
86 | #define RPC_CWNDSCALE (1U << RPC_CWNDSHIFT) | |
87 | #define RPC_INITCWND RPC_CWNDSCALE | |
88 | #define RPC_MAXCWND(xprt) ((xprt)->max_reqs << RPC_CWNDSHIFT) | |
89 | ||
90 | #define RPCXPRT_CONGESTED(xprt) ((xprt)->cong >= (xprt)->cwnd) | |
1da177e4 | 91 | |
81c098af TT |
92 | /** |
93 | * xprt_register_transport - register a transport implementation | |
94 | * @transport: transport to register | |
95 | * | |
96 | * If a transport implementation is loaded as a kernel module, it can | |
97 | * call this interface to make itself known to the RPC client. | |
98 | * | |
99 | * Returns: | |
100 | * 0: transport successfully registered | |
101 | * -EEXIST: transport already registered | |
102 | * -EINVAL: transport module being unloaded | |
103 | */ | |
104 | int xprt_register_transport(struct xprt_class *transport) | |
105 | { | |
106 | struct xprt_class *t; | |
107 | int result; | |
108 | ||
109 | result = -EEXIST; | |
110 | spin_lock(&xprt_list_lock); | |
111 | list_for_each_entry(t, &xprt_list, list) { | |
112 | /* don't register the same transport class twice */ | |
4fa016eb | 113 | if (t->ident == transport->ident) |
81c098af TT |
114 | goto out; |
115 | } | |
116 | ||
c9f6cde6 DL |
117 | list_add_tail(&transport->list, &xprt_list); |
118 | printk(KERN_INFO "RPC: Registered %s transport module.\n", | |
119 | transport->name); | |
120 | result = 0; | |
81c098af TT |
121 | |
122 | out: | |
123 | spin_unlock(&xprt_list_lock); | |
124 | return result; | |
125 | } | |
126 | EXPORT_SYMBOL_GPL(xprt_register_transport); | |
127 | ||
128 | /** | |
129 | * xprt_unregister_transport - unregister a transport implementation | |
65b6e42c | 130 | * @transport: transport to unregister |
81c098af TT |
131 | * |
132 | * Returns: | |
133 | * 0: transport successfully unregistered | |
134 | * -ENOENT: transport never registered | |
135 | */ | |
136 | int xprt_unregister_transport(struct xprt_class *transport) | |
137 | { | |
138 | struct xprt_class *t; | |
139 | int result; | |
140 | ||
141 | result = 0; | |
142 | spin_lock(&xprt_list_lock); | |
143 | list_for_each_entry(t, &xprt_list, list) { | |
144 | if (t == transport) { | |
145 | printk(KERN_INFO | |
146 | "RPC: Unregistered %s transport module.\n", | |
147 | transport->name); | |
148 | list_del_init(&transport->list); | |
81c098af TT |
149 | goto out; |
150 | } | |
151 | } | |
152 | result = -ENOENT; | |
153 | ||
154 | out: | |
155 | spin_unlock(&xprt_list_lock); | |
156 | return result; | |
157 | } | |
158 | EXPORT_SYMBOL_GPL(xprt_unregister_transport); | |
159 | ||
441e3e24 TT |
160 | /** |
161 | * xprt_load_transport - load a transport implementation | |
162 | * @transport_name: transport to load | |
163 | * | |
164 | * Returns: | |
165 | * 0: transport successfully loaded | |
166 | * -ENOENT: transport module not available | |
167 | */ | |
168 | int xprt_load_transport(const char *transport_name) | |
169 | { | |
170 | struct xprt_class *t; | |
441e3e24 TT |
171 | int result; |
172 | ||
173 | result = 0; | |
174 | spin_lock(&xprt_list_lock); | |
175 | list_for_each_entry(t, &xprt_list, list) { | |
176 | if (strcmp(t->name, transport_name) == 0) { | |
177 | spin_unlock(&xprt_list_lock); | |
178 | goto out; | |
179 | } | |
180 | } | |
181 | spin_unlock(&xprt_list_lock); | |
ef7ffe8f | 182 | result = request_module("xprt%s", transport_name); |
441e3e24 TT |
183 | out: |
184 | return result; | |
185 | } | |
186 | EXPORT_SYMBOL_GPL(xprt_load_transport); | |
187 | ||
12a80469 CL |
188 | /** |
189 | * xprt_reserve_xprt - serialize write access to transports | |
190 | * @task: task that is requesting access to the transport | |
177c27bf | 191 | * @xprt: pointer to the target transport |
12a80469 CL |
192 | * |
193 | * This prevents mixing the payload of separate requests, and prevents | |
194 | * transport connects from colliding with writes. No congestion control | |
195 | * is provided. | |
196 | */ | |
43cedbf0 | 197 | int xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task) |
12a80469 | 198 | { |
12a80469 | 199 | struct rpc_rqst *req = task->tk_rqstp; |
34006cee | 200 | int priority; |
12a80469 CL |
201 | |
202 | if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) { | |
203 | if (task == xprt->snd_task) | |
204 | return 1; | |
12a80469 CL |
205 | goto out_sleep; |
206 | } | |
207 | xprt->snd_task = task; | |
43cedbf0 TM |
208 | if (req != NULL) { |
209 | req->rq_bytes_sent = 0; | |
210 | req->rq_ntrans++; | |
211 | } | |
4d4a76f3 | 212 | |
12a80469 CL |
213 | return 1; |
214 | ||
215 | out_sleep: | |
46121cf7 | 216 | dprintk("RPC: %5u failed to lock transport %p\n", |
12a80469 CL |
217 | task->tk_pid, xprt); |
218 | task->tk_timeout = 0; | |
219 | task->tk_status = -EAGAIN; | |
34006cee TM |
220 | if (req == NULL) |
221 | priority = RPC_PRIORITY_LOW; | |
222 | else if (!req->rq_ntrans) | |
223 | priority = RPC_PRIORITY_NORMAL; | |
12a80469 | 224 | else |
34006cee TM |
225 | priority = RPC_PRIORITY_HIGH; |
226 | rpc_sleep_on_priority(&xprt->sending, task, NULL, priority); | |
12a80469 CL |
227 | return 0; |
228 | } | |
12444809 | 229 | EXPORT_SYMBOL_GPL(xprt_reserve_xprt); |
12a80469 | 230 | |
632e3bdc TM |
231 | static void xprt_clear_locked(struct rpc_xprt *xprt) |
232 | { | |
233 | xprt->snd_task = NULL; | |
d19751e7 | 234 | if (!test_bit(XPRT_CLOSE_WAIT, &xprt->state)) { |
632e3bdc TM |
235 | smp_mb__before_clear_bit(); |
236 | clear_bit(XPRT_LOCKED, &xprt->state); | |
237 | smp_mb__after_clear_bit(); | |
238 | } else | |
c1384c9c | 239 | queue_work(rpciod_workqueue, &xprt->task_cleanup); |
632e3bdc TM |
240 | } |
241 | ||
1da177e4 | 242 | /* |
12a80469 CL |
243 | * xprt_reserve_xprt_cong - serialize write access to transports |
244 | * @task: task that is requesting access to the transport | |
245 | * | |
246 | * Same as xprt_reserve_xprt, but Van Jacobson congestion control is | |
247 | * integrated into the decision of whether a request is allowed to be | |
248 | * woken up and given access to the transport. | |
1da177e4 | 249 | */ |
43cedbf0 | 250 | int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task) |
1da177e4 LT |
251 | { |
252 | struct rpc_rqst *req = task->tk_rqstp; | |
34006cee | 253 | int priority; |
1da177e4 | 254 | |
2226feb6 | 255 | if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) { |
1da177e4 LT |
256 | if (task == xprt->snd_task) |
257 | return 1; | |
1da177e4 LT |
258 | goto out_sleep; |
259 | } | |
43cedbf0 TM |
260 | if (req == NULL) { |
261 | xprt->snd_task = task; | |
262 | return 1; | |
263 | } | |
12a80469 | 264 | if (__xprt_get_cong(xprt, task)) { |
1da177e4 | 265 | xprt->snd_task = task; |
43cedbf0 TM |
266 | req->rq_bytes_sent = 0; |
267 | req->rq_ntrans++; | |
1da177e4 LT |
268 | return 1; |
269 | } | |
632e3bdc | 270 | xprt_clear_locked(xprt); |
1da177e4 | 271 | out_sleep: |
46121cf7 | 272 | dprintk("RPC: %5u failed to lock transport %p\n", task->tk_pid, xprt); |
1da177e4 LT |
273 | task->tk_timeout = 0; |
274 | task->tk_status = -EAGAIN; | |
34006cee TM |
275 | if (req == NULL) |
276 | priority = RPC_PRIORITY_LOW; | |
277 | else if (!req->rq_ntrans) | |
278 | priority = RPC_PRIORITY_NORMAL; | |
1da177e4 | 279 | else |
34006cee TM |
280 | priority = RPC_PRIORITY_HIGH; |
281 | rpc_sleep_on_priority(&xprt->sending, task, NULL, priority); | |
1da177e4 LT |
282 | return 0; |
283 | } | |
12444809 | 284 | EXPORT_SYMBOL_GPL(xprt_reserve_xprt_cong); |
1da177e4 | 285 | |
12a80469 | 286 | static inline int xprt_lock_write(struct rpc_xprt *xprt, struct rpc_task *task) |
1da177e4 LT |
287 | { |
288 | int retval; | |
289 | ||
4a0f8c04 | 290 | spin_lock_bh(&xprt->transport_lock); |
43cedbf0 | 291 | retval = xprt->ops->reserve_xprt(xprt, task); |
4a0f8c04 | 292 | spin_unlock_bh(&xprt->transport_lock); |
1da177e4 LT |
293 | return retval; |
294 | } | |
295 | ||
961a828d | 296 | static bool __xprt_lock_write_func(struct rpc_task *task, void *data) |
49e9a890 | 297 | { |
961a828d | 298 | struct rpc_xprt *xprt = data; |
49e9a890 CL |
299 | struct rpc_rqst *req; |
300 | ||
49e9a890 CL |
301 | req = task->tk_rqstp; |
302 | xprt->snd_task = task; | |
303 | if (req) { | |
304 | req->rq_bytes_sent = 0; | |
305 | req->rq_ntrans++; | |
306 | } | |
961a828d TM |
307 | return true; |
308 | } | |
49e9a890 | 309 | |
961a828d TM |
310 | static void __xprt_lock_write_next(struct rpc_xprt *xprt) |
311 | { | |
312 | if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) | |
313 | return; | |
314 | ||
315 | if (rpc_wake_up_first(&xprt->sending, __xprt_lock_write_func, xprt)) | |
316 | return; | |
632e3bdc | 317 | xprt_clear_locked(xprt); |
49e9a890 CL |
318 | } |
319 | ||
961a828d | 320 | static bool __xprt_lock_write_cong_func(struct rpc_task *task, void *data) |
1da177e4 | 321 | { |
961a828d | 322 | struct rpc_xprt *xprt = data; |
43cedbf0 | 323 | struct rpc_rqst *req; |
1da177e4 | 324 | |
43cedbf0 TM |
325 | req = task->tk_rqstp; |
326 | if (req == NULL) { | |
327 | xprt->snd_task = task; | |
961a828d | 328 | return true; |
43cedbf0 | 329 | } |
49e9a890 | 330 | if (__xprt_get_cong(xprt, task)) { |
1da177e4 | 331 | xprt->snd_task = task; |
43cedbf0 TM |
332 | req->rq_bytes_sent = 0; |
333 | req->rq_ntrans++; | |
961a828d | 334 | return true; |
1da177e4 | 335 | } |
961a828d TM |
336 | return false; |
337 | } | |
338 | ||
339 | static void __xprt_lock_write_next_cong(struct rpc_xprt *xprt) | |
340 | { | |
341 | if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) | |
342 | return; | |
343 | if (RPCXPRT_CONGESTED(xprt)) | |
344 | goto out_unlock; | |
345 | if (rpc_wake_up_first(&xprt->sending, __xprt_lock_write_cong_func, xprt)) | |
346 | return; | |
1da177e4 | 347 | out_unlock: |
632e3bdc | 348 | xprt_clear_locked(xprt); |
1da177e4 LT |
349 | } |
350 | ||
49e9a890 CL |
351 | /** |
352 | * xprt_release_xprt - allow other requests to use a transport | |
353 | * @xprt: transport with other tasks potentially waiting | |
354 | * @task: task that is releasing access to the transport | |
355 | * | |
356 | * Note that "task" can be NULL. No congestion control is provided. | |
1da177e4 | 357 | */ |
49e9a890 | 358 | void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task) |
1da177e4 LT |
359 | { |
360 | if (xprt->snd_task == task) { | |
632e3bdc | 361 | xprt_clear_locked(xprt); |
1da177e4 LT |
362 | __xprt_lock_write_next(xprt); |
363 | } | |
364 | } | |
12444809 | 365 | EXPORT_SYMBOL_GPL(xprt_release_xprt); |
1da177e4 | 366 | |
49e9a890 CL |
367 | /** |
368 | * xprt_release_xprt_cong - allow other requests to use a transport | |
369 | * @xprt: transport with other tasks potentially waiting | |
370 | * @task: task that is releasing access to the transport | |
371 | * | |
372 | * Note that "task" can be NULL. Another task is awoken to use the | |
373 | * transport if the transport's congestion window allows it. | |
374 | */ | |
375 | void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task) | |
376 | { | |
377 | if (xprt->snd_task == task) { | |
632e3bdc | 378 | xprt_clear_locked(xprt); |
49e9a890 CL |
379 | __xprt_lock_write_next_cong(xprt); |
380 | } | |
381 | } | |
12444809 | 382 | EXPORT_SYMBOL_GPL(xprt_release_xprt_cong); |
49e9a890 CL |
383 | |
384 | static inline void xprt_release_write(struct rpc_xprt *xprt, struct rpc_task *task) | |
1da177e4 | 385 | { |
4a0f8c04 | 386 | spin_lock_bh(&xprt->transport_lock); |
49e9a890 | 387 | xprt->ops->release_xprt(xprt, task); |
4a0f8c04 | 388 | spin_unlock_bh(&xprt->transport_lock); |
1da177e4 LT |
389 | } |
390 | ||
1da177e4 LT |
391 | /* |
392 | * Van Jacobson congestion avoidance. Check if the congestion window | |
393 | * overflowed. Put the task to sleep if this is the case. | |
394 | */ | |
395 | static int | |
396 | __xprt_get_cong(struct rpc_xprt *xprt, struct rpc_task *task) | |
397 | { | |
398 | struct rpc_rqst *req = task->tk_rqstp; | |
399 | ||
400 | if (req->rq_cong) | |
401 | return 1; | |
46121cf7 | 402 | dprintk("RPC: %5u xprt_cwnd_limited cong = %lu cwnd = %lu\n", |
1da177e4 LT |
403 | task->tk_pid, xprt->cong, xprt->cwnd); |
404 | if (RPCXPRT_CONGESTED(xprt)) | |
405 | return 0; | |
406 | req->rq_cong = 1; | |
407 | xprt->cong += RPC_CWNDSCALE; | |
408 | return 1; | |
409 | } | |
410 | ||
411 | /* | |
412 | * Adjust the congestion window, and wake up the next task | |
413 | * that has been sleeping due to congestion | |
414 | */ | |
415 | static void | |
416 | __xprt_put_cong(struct rpc_xprt *xprt, struct rpc_rqst *req) | |
417 | { | |
418 | if (!req->rq_cong) | |
419 | return; | |
420 | req->rq_cong = 0; | |
421 | xprt->cong -= RPC_CWNDSCALE; | |
49e9a890 | 422 | __xprt_lock_write_next_cong(xprt); |
1da177e4 LT |
423 | } |
424 | ||
a58dd398 CL |
425 | /** |
426 | * xprt_release_rqst_cong - housekeeping when request is complete | |
427 | * @task: RPC request that recently completed | |
428 | * | |
429 | * Useful for transports that require congestion control. | |
430 | */ | |
431 | void xprt_release_rqst_cong(struct rpc_task *task) | |
432 | { | |
433 | __xprt_put_cong(task->tk_xprt, task->tk_rqstp); | |
434 | } | |
12444809 | 435 | EXPORT_SYMBOL_GPL(xprt_release_rqst_cong); |
a58dd398 | 436 | |
46c0ee8b CL |
437 | /** |
438 | * xprt_adjust_cwnd - adjust transport congestion window | |
439 | * @task: recently completed RPC request used to adjust window | |
440 | * @result: result code of completed RPC request | |
441 | * | |
1da177e4 LT |
442 | * We use a time-smoothed congestion estimator to avoid heavy oscillation. |
443 | */ | |
46c0ee8b | 444 | void xprt_adjust_cwnd(struct rpc_task *task, int result) |
1da177e4 | 445 | { |
46c0ee8b CL |
446 | struct rpc_rqst *req = task->tk_rqstp; |
447 | struct rpc_xprt *xprt = task->tk_xprt; | |
448 | unsigned long cwnd = xprt->cwnd; | |
1da177e4 | 449 | |
1da177e4 LT |
450 | if (result >= 0 && cwnd <= xprt->cong) { |
451 | /* The (cwnd >> 1) term makes sure | |
452 | * the result gets rounded properly. */ | |
453 | cwnd += (RPC_CWNDSCALE * RPC_CWNDSCALE + (cwnd >> 1)) / cwnd; | |
454 | if (cwnd > RPC_MAXCWND(xprt)) | |
455 | cwnd = RPC_MAXCWND(xprt); | |
49e9a890 | 456 | __xprt_lock_write_next_cong(xprt); |
1da177e4 LT |
457 | } else if (result == -ETIMEDOUT) { |
458 | cwnd >>= 1; | |
459 | if (cwnd < RPC_CWNDSCALE) | |
460 | cwnd = RPC_CWNDSCALE; | |
461 | } | |
46121cf7 | 462 | dprintk("RPC: cong %ld, cwnd was %ld, now %ld\n", |
1da177e4 LT |
463 | xprt->cong, xprt->cwnd, cwnd); |
464 | xprt->cwnd = cwnd; | |
46c0ee8b | 465 | __xprt_put_cong(xprt, req); |
1da177e4 | 466 | } |
12444809 | 467 | EXPORT_SYMBOL_GPL(xprt_adjust_cwnd); |
1da177e4 | 468 | |
44fbac22 CL |
469 | /** |
470 | * xprt_wake_pending_tasks - wake all tasks on a transport's pending queue | |
471 | * @xprt: transport with waiting tasks | |
472 | * @status: result code to plant in each task before waking it | |
473 | * | |
474 | */ | |
475 | void xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status) | |
476 | { | |
477 | if (status < 0) | |
478 | rpc_wake_up_status(&xprt->pending, status); | |
479 | else | |
480 | rpc_wake_up(&xprt->pending); | |
481 | } | |
12444809 | 482 | EXPORT_SYMBOL_GPL(xprt_wake_pending_tasks); |
44fbac22 | 483 | |
c7b2cae8 CL |
484 | /** |
485 | * xprt_wait_for_buffer_space - wait for transport output buffer to clear | |
486 | * @task: task to be put to sleep | |
0b80ae42 | 487 | * @action: function pointer to be executed after wait |
c7b2cae8 | 488 | */ |
b6ddf64f | 489 | void xprt_wait_for_buffer_space(struct rpc_task *task, rpc_action action) |
c7b2cae8 CL |
490 | { |
491 | struct rpc_rqst *req = task->tk_rqstp; | |
492 | struct rpc_xprt *xprt = req->rq_xprt; | |
493 | ||
494 | task->tk_timeout = req->rq_timeout; | |
b6ddf64f | 495 | rpc_sleep_on(&xprt->pending, task, action); |
c7b2cae8 | 496 | } |
12444809 | 497 | EXPORT_SYMBOL_GPL(xprt_wait_for_buffer_space); |
c7b2cae8 CL |
498 | |
499 | /** | |
500 | * xprt_write_space - wake the task waiting for transport output buffer space | |
501 | * @xprt: transport with waiting tasks | |
502 | * | |
503 | * Can be called in a soft IRQ context, so xprt_write_space never sleeps. | |
504 | */ | |
505 | void xprt_write_space(struct rpc_xprt *xprt) | |
506 | { | |
c7b2cae8 CL |
507 | spin_lock_bh(&xprt->transport_lock); |
508 | if (xprt->snd_task) { | |
46121cf7 CL |
509 | dprintk("RPC: write space: waking waiting task on " |
510 | "xprt %p\n", xprt); | |
fda13939 | 511 | rpc_wake_up_queued_task(&xprt->pending, xprt->snd_task); |
c7b2cae8 CL |
512 | } |
513 | spin_unlock_bh(&xprt->transport_lock); | |
514 | } | |
12444809 | 515 | EXPORT_SYMBOL_GPL(xprt_write_space); |
c7b2cae8 | 516 | |
fe3aca29 CL |
517 | /** |
518 | * xprt_set_retrans_timeout_def - set a request's retransmit timeout | |
519 | * @task: task whose timeout is to be set | |
520 | * | |
521 | * Set a request's retransmit timeout based on the transport's | |
522 | * default timeout parameters. Used by transports that don't adjust | |
523 | * the retransmit timeout based on round-trip time estimation. | |
524 | */ | |
525 | void xprt_set_retrans_timeout_def(struct rpc_task *task) | |
526 | { | |
527 | task->tk_timeout = task->tk_rqstp->rq_timeout; | |
528 | } | |
12444809 | 529 | EXPORT_SYMBOL_GPL(xprt_set_retrans_timeout_def); |
fe3aca29 | 530 | |
2c53040f | 531 | /** |
fe3aca29 CL |
532 | * xprt_set_retrans_timeout_rtt - set a request's retransmit timeout |
533 | * @task: task whose timeout is to be set | |
cca5172a | 534 | * |
fe3aca29 CL |
535 | * Set a request's retransmit timeout using the RTT estimator. |
536 | */ | |
537 | void xprt_set_retrans_timeout_rtt(struct rpc_task *task) | |
538 | { | |
539 | int timer = task->tk_msg.rpc_proc->p_timer; | |
ba7392bb TM |
540 | struct rpc_clnt *clnt = task->tk_client; |
541 | struct rpc_rtt *rtt = clnt->cl_rtt; | |
fe3aca29 | 542 | struct rpc_rqst *req = task->tk_rqstp; |
ba7392bb | 543 | unsigned long max_timeout = clnt->cl_timeout->to_maxval; |
fe3aca29 CL |
544 | |
545 | task->tk_timeout = rpc_calc_rto(rtt, timer); | |
546 | task->tk_timeout <<= rpc_ntimeo(rtt, timer) + req->rq_retries; | |
547 | if (task->tk_timeout > max_timeout || task->tk_timeout == 0) | |
548 | task->tk_timeout = max_timeout; | |
549 | } | |
12444809 | 550 | EXPORT_SYMBOL_GPL(xprt_set_retrans_timeout_rtt); |
fe3aca29 | 551 | |
1da177e4 LT |
552 | static void xprt_reset_majortimeo(struct rpc_rqst *req) |
553 | { | |
ba7392bb | 554 | const struct rpc_timeout *to = req->rq_task->tk_client->cl_timeout; |
1da177e4 LT |
555 | |
556 | req->rq_majortimeo = req->rq_timeout; | |
557 | if (to->to_exponential) | |
558 | req->rq_majortimeo <<= to->to_retries; | |
559 | else | |
560 | req->rq_majortimeo += to->to_increment * to->to_retries; | |
561 | if (req->rq_majortimeo > to->to_maxval || req->rq_majortimeo == 0) | |
562 | req->rq_majortimeo = to->to_maxval; | |
563 | req->rq_majortimeo += jiffies; | |
564 | } | |
565 | ||
9903cd1c CL |
566 | /** |
567 | * xprt_adjust_timeout - adjust timeout values for next retransmit | |
568 | * @req: RPC request containing parameters to use for the adjustment | |
569 | * | |
1da177e4 LT |
570 | */ |
571 | int xprt_adjust_timeout(struct rpc_rqst *req) | |
572 | { | |
573 | struct rpc_xprt *xprt = req->rq_xprt; | |
ba7392bb | 574 | const struct rpc_timeout *to = req->rq_task->tk_client->cl_timeout; |
1da177e4 LT |
575 | int status = 0; |
576 | ||
577 | if (time_before(jiffies, req->rq_majortimeo)) { | |
578 | if (to->to_exponential) | |
579 | req->rq_timeout <<= 1; | |
580 | else | |
581 | req->rq_timeout += to->to_increment; | |
582 | if (to->to_maxval && req->rq_timeout >= to->to_maxval) | |
583 | req->rq_timeout = to->to_maxval; | |
584 | req->rq_retries++; | |
1da177e4 LT |
585 | } else { |
586 | req->rq_timeout = to->to_initval; | |
587 | req->rq_retries = 0; | |
588 | xprt_reset_majortimeo(req); | |
589 | /* Reset the RTT counters == "slow start" */ | |
4a0f8c04 | 590 | spin_lock_bh(&xprt->transport_lock); |
1da177e4 | 591 | rpc_init_rtt(req->rq_task->tk_client->cl_rtt, to->to_initval); |
4a0f8c04 | 592 | spin_unlock_bh(&xprt->transport_lock); |
1da177e4 LT |
593 | status = -ETIMEDOUT; |
594 | } | |
595 | ||
596 | if (req->rq_timeout == 0) { | |
597 | printk(KERN_WARNING "xprt_adjust_timeout: rq_timeout = 0!\n"); | |
598 | req->rq_timeout = 5 * HZ; | |
599 | } | |
600 | return status; | |
601 | } | |
602 | ||
65f27f38 | 603 | static void xprt_autoclose(struct work_struct *work) |
1da177e4 | 604 | { |
65f27f38 DH |
605 | struct rpc_xprt *xprt = |
606 | container_of(work, struct rpc_xprt, task_cleanup); | |
1da177e4 | 607 | |
a246b010 | 608 | xprt->ops->close(xprt); |
66af1e55 | 609 | clear_bit(XPRT_CLOSE_WAIT, &xprt->state); |
1da177e4 LT |
610 | xprt_release_write(xprt, NULL); |
611 | } | |
612 | ||
9903cd1c | 613 | /** |
62da3b24 | 614 | * xprt_disconnect_done - mark a transport as disconnected |
9903cd1c CL |
615 | * @xprt: transport to flag for disconnect |
616 | * | |
1da177e4 | 617 | */ |
62da3b24 | 618 | void xprt_disconnect_done(struct rpc_xprt *xprt) |
1da177e4 | 619 | { |
46121cf7 | 620 | dprintk("RPC: disconnected transport %p\n", xprt); |
4a0f8c04 | 621 | spin_lock_bh(&xprt->transport_lock); |
1da177e4 | 622 | xprt_clear_connected(xprt); |
2a491991 | 623 | xprt_wake_pending_tasks(xprt, -EAGAIN); |
4a0f8c04 | 624 | spin_unlock_bh(&xprt->transport_lock); |
1da177e4 | 625 | } |
62da3b24 | 626 | EXPORT_SYMBOL_GPL(xprt_disconnect_done); |
1da177e4 | 627 | |
66af1e55 TM |
628 | /** |
629 | * xprt_force_disconnect - force a transport to disconnect | |
630 | * @xprt: transport to disconnect | |
631 | * | |
632 | */ | |
633 | void xprt_force_disconnect(struct rpc_xprt *xprt) | |
634 | { | |
635 | /* Don't race with the test_bit() in xprt_clear_locked() */ | |
636 | spin_lock_bh(&xprt->transport_lock); | |
637 | set_bit(XPRT_CLOSE_WAIT, &xprt->state); | |
638 | /* Try to schedule an autoclose RPC call */ | |
639 | if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0) | |
640 | queue_work(rpciod_workqueue, &xprt->task_cleanup); | |
2a491991 | 641 | xprt_wake_pending_tasks(xprt, -EAGAIN); |
66af1e55 TM |
642 | spin_unlock_bh(&xprt->transport_lock); |
643 | } | |
66af1e55 | 644 | |
7c1d71cf TM |
645 | /** |
646 | * xprt_conditional_disconnect - force a transport to disconnect | |
647 | * @xprt: transport to disconnect | |
648 | * @cookie: 'connection cookie' | |
649 | * | |
650 | * This attempts to break the connection if and only if 'cookie' matches | |
651 | * the current transport 'connection cookie'. It ensures that we don't | |
652 | * try to break the connection more than once when we need to retransmit | |
653 | * a batch of RPC requests. | |
654 | * | |
655 | */ | |
656 | void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie) | |
657 | { | |
658 | /* Don't race with the test_bit() in xprt_clear_locked() */ | |
659 | spin_lock_bh(&xprt->transport_lock); | |
660 | if (cookie != xprt->connect_cookie) | |
661 | goto out; | |
662 | if (test_bit(XPRT_CLOSING, &xprt->state) || !xprt_connected(xprt)) | |
663 | goto out; | |
664 | set_bit(XPRT_CLOSE_WAIT, &xprt->state); | |
665 | /* Try to schedule an autoclose RPC call */ | |
666 | if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0) | |
667 | queue_work(rpciod_workqueue, &xprt->task_cleanup); | |
2a491991 | 668 | xprt_wake_pending_tasks(xprt, -EAGAIN); |
7c1d71cf TM |
669 | out: |
670 | spin_unlock_bh(&xprt->transport_lock); | |
671 | } | |
672 | ||
1da177e4 LT |
673 | static void |
674 | xprt_init_autodisconnect(unsigned long data) | |
675 | { | |
676 | struct rpc_xprt *xprt = (struct rpc_xprt *)data; | |
677 | ||
4a0f8c04 | 678 | spin_lock(&xprt->transport_lock); |
d19751e7 | 679 | if (!list_empty(&xprt->recv)) |
1da177e4 | 680 | goto out_abort; |
2226feb6 | 681 | if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) |
1da177e4 | 682 | goto out_abort; |
4a0f8c04 | 683 | spin_unlock(&xprt->transport_lock); |
f75e6745 TM |
684 | set_bit(XPRT_CONNECTION_CLOSE, &xprt->state); |
685 | queue_work(rpciod_workqueue, &xprt->task_cleanup); | |
1da177e4 LT |
686 | return; |
687 | out_abort: | |
4a0f8c04 | 688 | spin_unlock(&xprt->transport_lock); |
1da177e4 LT |
689 | } |
690 | ||
9903cd1c CL |
691 | /** |
692 | * xprt_connect - schedule a transport connect operation | |
693 | * @task: RPC task that is requesting the connect | |
1da177e4 LT |
694 | * |
695 | */ | |
696 | void xprt_connect(struct rpc_task *task) | |
697 | { | |
698 | struct rpc_xprt *xprt = task->tk_xprt; | |
699 | ||
46121cf7 | 700 | dprintk("RPC: %5u xprt_connect xprt %p %s connected\n", task->tk_pid, |
1da177e4 LT |
701 | xprt, (xprt_connected(xprt) ? "is" : "is not")); |
702 | ||
ec739ef0 | 703 | if (!xprt_bound(xprt)) { |
01d37c42 | 704 | task->tk_status = -EAGAIN; |
1da177e4 LT |
705 | return; |
706 | } | |
707 | if (!xprt_lock_write(xprt, task)) | |
708 | return; | |
feb8ca37 TM |
709 | |
710 | if (test_and_clear_bit(XPRT_CLOSE_WAIT, &xprt->state)) | |
711 | xprt->ops->close(xprt); | |
712 | ||
1da177e4 | 713 | if (xprt_connected(xprt)) |
a246b010 CL |
714 | xprt_release_write(xprt, task); |
715 | else { | |
87e3c055 | 716 | task->tk_rqstp->rq_bytes_sent = 0; |
a8ce4a8f | 717 | task->tk_timeout = task->tk_rqstp->rq_timeout; |
5d00837b | 718 | rpc_sleep_on(&xprt->pending, task, xprt_connect_status); |
0b9e7943 TM |
719 | |
720 | if (test_bit(XPRT_CLOSING, &xprt->state)) | |
721 | return; | |
722 | if (xprt_test_and_set_connecting(xprt)) | |
723 | return; | |
262ca07d | 724 | xprt->stat.connect_start = jiffies; |
a246b010 | 725 | xprt->ops->connect(task); |
1da177e4 | 726 | } |
1da177e4 LT |
727 | } |
728 | ||
9903cd1c | 729 | static void xprt_connect_status(struct rpc_task *task) |
1da177e4 LT |
730 | { |
731 | struct rpc_xprt *xprt = task->tk_xprt; | |
732 | ||
cd983ef8 | 733 | if (task->tk_status == 0) { |
262ca07d CL |
734 | xprt->stat.connect_count++; |
735 | xprt->stat.connect_time += (long)jiffies - xprt->stat.connect_start; | |
46121cf7 | 736 | dprintk("RPC: %5u xprt_connect_status: connection established\n", |
1da177e4 LT |
737 | task->tk_pid); |
738 | return; | |
739 | } | |
740 | ||
1da177e4 | 741 | switch (task->tk_status) { |
2a491991 TM |
742 | case -EAGAIN: |
743 | dprintk("RPC: %5u xprt_connect_status: retrying\n", task->tk_pid); | |
23475d66 | 744 | break; |
1da177e4 | 745 | case -ETIMEDOUT: |
46121cf7 CL |
746 | dprintk("RPC: %5u xprt_connect_status: connect attempt timed " |
747 | "out\n", task->tk_pid); | |
1da177e4 LT |
748 | break; |
749 | default: | |
46121cf7 CL |
750 | dprintk("RPC: %5u xprt_connect_status: error %d connecting to " |
751 | "server %s\n", task->tk_pid, -task->tk_status, | |
4e0038b6 | 752 | xprt->servername); |
23475d66 CL |
753 | xprt_release_write(xprt, task); |
754 | task->tk_status = -EIO; | |
1da177e4 | 755 | } |
1da177e4 LT |
756 | } |
757 | ||
9903cd1c CL |
758 | /** |
759 | * xprt_lookup_rqst - find an RPC request corresponding to an XID | |
760 | * @xprt: transport on which the original request was transmitted | |
761 | * @xid: RPC XID of incoming reply | |
762 | * | |
1da177e4 | 763 | */ |
d8ed029d | 764 | struct rpc_rqst *xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid) |
1da177e4 | 765 | { |
8f3a6de3 | 766 | struct rpc_rqst *entry; |
1da177e4 | 767 | |
8f3a6de3 | 768 | list_for_each_entry(entry, &xprt->recv, rq_list) |
262ca07d CL |
769 | if (entry->rq_xid == xid) |
770 | return entry; | |
46121cf7 CL |
771 | |
772 | dprintk("RPC: xprt_lookup_rqst did not find xid %08x\n", | |
773 | ntohl(xid)); | |
262ca07d CL |
774 | xprt->stat.bad_xids++; |
775 | return NULL; | |
1da177e4 | 776 | } |
12444809 | 777 | EXPORT_SYMBOL_GPL(xprt_lookup_rqst); |
1da177e4 | 778 | |
bbc72cea | 779 | static void xprt_update_rtt(struct rpc_task *task) |
1570c1e4 CL |
780 | { |
781 | struct rpc_rqst *req = task->tk_rqstp; | |
782 | struct rpc_rtt *rtt = task->tk_client->cl_rtt; | |
95c96174 | 783 | unsigned int timer = task->tk_msg.rpc_proc->p_timer; |
d60dbb20 | 784 | long m = usecs_to_jiffies(ktime_to_us(req->rq_rtt)); |
1570c1e4 CL |
785 | |
786 | if (timer) { | |
787 | if (req->rq_ntrans == 1) | |
ff839970 | 788 | rpc_update_rtt(rtt, timer, m); |
1570c1e4 CL |
789 | rpc_set_timeo(rtt, timer, req->rq_ntrans - 1); |
790 | } | |
791 | } | |
792 | ||
9903cd1c CL |
793 | /** |
794 | * xprt_complete_rqst - called when reply processing is complete | |
1570c1e4 | 795 | * @task: RPC request that recently completed |
9903cd1c CL |
796 | * @copied: actual number of bytes received from the transport |
797 | * | |
1570c1e4 | 798 | * Caller holds transport lock. |
1da177e4 | 799 | */ |
1570c1e4 | 800 | void xprt_complete_rqst(struct rpc_task *task, int copied) |
1da177e4 | 801 | { |
1570c1e4 | 802 | struct rpc_rqst *req = task->tk_rqstp; |
fda13939 | 803 | struct rpc_xprt *xprt = req->rq_xprt; |
1da177e4 | 804 | |
1570c1e4 CL |
805 | dprintk("RPC: %5u xid %08x complete (%d bytes received)\n", |
806 | task->tk_pid, ntohl(req->rq_xid), copied); | |
1da177e4 | 807 | |
fda13939 | 808 | xprt->stat.recvs++; |
d60dbb20 | 809 | req->rq_rtt = ktime_sub(ktime_get(), req->rq_xtime); |
bbc72cea CL |
810 | if (xprt->ops->timer != NULL) |
811 | xprt_update_rtt(task); | |
ef759a2e | 812 | |
1da177e4 | 813 | list_del_init(&req->rq_list); |
1e799b67 | 814 | req->rq_private_buf.len = copied; |
dd2b63d0 RL |
815 | /* Ensure all writes are done before we update */ |
816 | /* req->rq_reply_bytes_recvd */ | |
43ac3f29 | 817 | smp_wmb(); |
dd2b63d0 | 818 | req->rq_reply_bytes_recvd = copied; |
fda13939 | 819 | rpc_wake_up_queued_task(&xprt->pending, task); |
1da177e4 | 820 | } |
12444809 | 821 | EXPORT_SYMBOL_GPL(xprt_complete_rqst); |
1da177e4 | 822 | |
46c0ee8b | 823 | static void xprt_timer(struct rpc_task *task) |
1da177e4 | 824 | { |
46c0ee8b | 825 | struct rpc_rqst *req = task->tk_rqstp; |
1da177e4 LT |
826 | struct rpc_xprt *xprt = req->rq_xprt; |
827 | ||
5d00837b TM |
828 | if (task->tk_status != -ETIMEDOUT) |
829 | return; | |
46121cf7 | 830 | dprintk("RPC: %5u xprt_timer\n", task->tk_pid); |
1da177e4 | 831 | |
5d00837b | 832 | spin_lock_bh(&xprt->transport_lock); |
dd2b63d0 | 833 | if (!req->rq_reply_bytes_recvd) { |
46c0ee8b CL |
834 | if (xprt->ops->timer) |
835 | xprt->ops->timer(task); | |
5d00837b TM |
836 | } else |
837 | task->tk_status = 0; | |
838 | spin_unlock_bh(&xprt->transport_lock); | |
1da177e4 LT |
839 | } |
840 | ||
4cfc7e60 RI |
841 | static inline int xprt_has_timer(struct rpc_xprt *xprt) |
842 | { | |
843 | return xprt->idle_timeout != 0; | |
844 | } | |
845 | ||
9903cd1c CL |
846 | /** |
847 | * xprt_prepare_transmit - reserve the transport before sending a request | |
848 | * @task: RPC task about to send a request | |
849 | * | |
1da177e4 | 850 | */ |
9903cd1c | 851 | int xprt_prepare_transmit(struct rpc_task *task) |
1da177e4 LT |
852 | { |
853 | struct rpc_rqst *req = task->tk_rqstp; | |
854 | struct rpc_xprt *xprt = req->rq_xprt; | |
855 | int err = 0; | |
856 | ||
46121cf7 | 857 | dprintk("RPC: %5u xprt_prepare_transmit\n", task->tk_pid); |
1da177e4 | 858 | |
4a0f8c04 | 859 | spin_lock_bh(&xprt->transport_lock); |
dd2b63d0 RL |
860 | if (req->rq_reply_bytes_recvd && !req->rq_bytes_sent) { |
861 | err = req->rq_reply_bytes_recvd; | |
1da177e4 LT |
862 | goto out_unlock; |
863 | } | |
43cedbf0 | 864 | if (!xprt->ops->reserve_xprt(xprt, task)) |
1da177e4 | 865 | err = -EAGAIN; |
1da177e4 | 866 | out_unlock: |
4a0f8c04 | 867 | spin_unlock_bh(&xprt->transport_lock); |
1da177e4 LT |
868 | return err; |
869 | } | |
870 | ||
e0ab53de | 871 | void xprt_end_transmit(struct rpc_task *task) |
5e5ce5be | 872 | { |
343952fa | 873 | xprt_release_write(task->tk_rqstp->rq_xprt, task); |
5e5ce5be TM |
874 | } |
875 | ||
9903cd1c CL |
876 | /** |
877 | * xprt_transmit - send an RPC request on a transport | |
878 | * @task: controlling RPC task | |
879 | * | |
880 | * We have to copy the iovec because sendmsg fiddles with its contents. | |
881 | */ | |
882 | void xprt_transmit(struct rpc_task *task) | |
1da177e4 | 883 | { |
1da177e4 LT |
884 | struct rpc_rqst *req = task->tk_rqstp; |
885 | struct rpc_xprt *xprt = req->rq_xprt; | |
15a45206 | 886 | int status, numreqs; |
1da177e4 | 887 | |
46121cf7 | 888 | dprintk("RPC: %5u xprt_transmit(%u)\n", task->tk_pid, req->rq_slen); |
1da177e4 | 889 | |
dd2b63d0 | 890 | if (!req->rq_reply_bytes_recvd) { |
55ae1aab RL |
891 | if (list_empty(&req->rq_list) && rpc_reply_expected(task)) { |
892 | /* | |
893 | * Add to the list only if we're expecting a reply | |
894 | */ | |
4a0f8c04 | 895 | spin_lock_bh(&xprt->transport_lock); |
1da177e4 LT |
896 | /* Update the softirq receive buffer */ |
897 | memcpy(&req->rq_private_buf, &req->rq_rcv_buf, | |
898 | sizeof(req->rq_private_buf)); | |
899 | /* Add request to the receive list */ | |
900 | list_add_tail(&req->rq_list, &xprt->recv); | |
4a0f8c04 | 901 | spin_unlock_bh(&xprt->transport_lock); |
1da177e4 | 902 | xprt_reset_majortimeo(req); |
0f9dc2b1 TM |
903 | /* Turn off autodisconnect */ |
904 | del_singleshot_timer_sync(&xprt->timer); | |
1da177e4 LT |
905 | } |
906 | } else if (!req->rq_bytes_sent) | |
907 | return; | |
908 | ||
7c1d71cf | 909 | req->rq_connect_cookie = xprt->connect_cookie; |
ff839970 | 910 | req->rq_xtime = ktime_get(); |
a246b010 | 911 | status = xprt->ops->send_request(task); |
c8485e4d TM |
912 | if (status != 0) { |
913 | task->tk_status = status; | |
914 | return; | |
915 | } | |
262ca07d | 916 | |
c8485e4d | 917 | dprintk("RPC: %5u xmit complete\n", task->tk_pid); |
468f8613 | 918 | task->tk_flags |= RPC_TASK_SENT; |
c8485e4d | 919 | spin_lock_bh(&xprt->transport_lock); |
262ca07d | 920 | |
c8485e4d | 921 | xprt->ops->set_retrans_timeout(task); |
262ca07d | 922 | |
15a45206 AA |
923 | numreqs = atomic_read(&xprt->num_reqs); |
924 | if (numreqs > xprt->stat.max_slots) | |
925 | xprt->stat.max_slots = numreqs; | |
c8485e4d TM |
926 | xprt->stat.sends++; |
927 | xprt->stat.req_u += xprt->stat.sends - xprt->stat.recvs; | |
928 | xprt->stat.bklog_u += xprt->backlog.qlen; | |
15a45206 AA |
929 | xprt->stat.sending_u += xprt->sending.qlen; |
930 | xprt->stat.pending_u += xprt->pending.qlen; | |
1da177e4 | 931 | |
c8485e4d TM |
932 | /* Don't race with disconnect */ |
933 | if (!xprt_connected(xprt)) | |
934 | task->tk_status = -ENOTCONN; | |
dd2b63d0 | 935 | else if (!req->rq_reply_bytes_recvd && rpc_reply_expected(task)) { |
55ae1aab RL |
936 | /* |
937 | * Sleep on the pending queue since | |
938 | * we're expecting a reply. | |
939 | */ | |
c8485e4d | 940 | rpc_sleep_on(&xprt->pending, task, xprt_timer); |
55ae1aab | 941 | } |
c8485e4d | 942 | spin_unlock_bh(&xprt->transport_lock); |
1da177e4 LT |
943 | } |
944 | ||
d9ba131d TM |
945 | static struct rpc_rqst *xprt_dynamic_alloc_slot(struct rpc_xprt *xprt, gfp_t gfp_flags) |
946 | { | |
947 | struct rpc_rqst *req = ERR_PTR(-EAGAIN); | |
948 | ||
949 | if (!atomic_add_unless(&xprt->num_reqs, 1, xprt->max_reqs)) | |
950 | goto out; | |
951 | req = kzalloc(sizeof(struct rpc_rqst), gfp_flags); | |
952 | if (req != NULL) | |
953 | goto out; | |
954 | atomic_dec(&xprt->num_reqs); | |
955 | req = ERR_PTR(-ENOMEM); | |
956 | out: | |
957 | return req; | |
958 | } | |
959 | ||
960 | static bool xprt_dynamic_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *req) | |
961 | { | |
962 | if (atomic_add_unless(&xprt->num_reqs, -1, xprt->min_reqs)) { | |
963 | kfree(req); | |
964 | return true; | |
965 | } | |
966 | return false; | |
967 | } | |
968 | ||
f39c1bfb | 969 | void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task) |
1da177e4 | 970 | { |
d9ba131d | 971 | struct rpc_rqst *req; |
1da177e4 | 972 | |
f39c1bfb | 973 | spin_lock(&xprt->reserve_lock); |
1da177e4 | 974 | if (!list_empty(&xprt->free)) { |
d9ba131d TM |
975 | req = list_entry(xprt->free.next, struct rpc_rqst, rq_list); |
976 | list_del(&req->rq_list); | |
977 | goto out_init_req; | |
978 | } | |
6b343099 | 979 | req = xprt_dynamic_alloc_slot(xprt, GFP_NOWAIT|__GFP_NOWARN); |
d9ba131d TM |
980 | if (!IS_ERR(req)) |
981 | goto out_init_req; | |
982 | switch (PTR_ERR(req)) { | |
983 | case -ENOMEM: | |
d9ba131d TM |
984 | dprintk("RPC: dynamic allocation of request slot " |
985 | "failed! Retrying\n"); | |
1afeaf5c | 986 | task->tk_status = -ENOMEM; |
d9ba131d TM |
987 | break; |
988 | case -EAGAIN: | |
989 | rpc_sleep_on(&xprt->backlog, task, NULL); | |
990 | dprintk("RPC: waiting for request slot\n"); | |
1afeaf5c TM |
991 | default: |
992 | task->tk_status = -EAGAIN; | |
1da177e4 | 993 | } |
f39c1bfb | 994 | spin_unlock(&xprt->reserve_lock); |
d9ba131d TM |
995 | return; |
996 | out_init_req: | |
997 | task->tk_status = 0; | |
998 | task->tk_rqstp = req; | |
999 | xprt_request_init(task, xprt); | |
f39c1bfb TM |
1000 | spin_unlock(&xprt->reserve_lock); |
1001 | } | |
1002 | EXPORT_SYMBOL_GPL(xprt_alloc_slot); | |
1003 | ||
1004 | void xprt_lock_and_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task) | |
1005 | { | |
1006 | /* Note: grabbing the xprt_lock_write() ensures that we throttle | |
1007 | * new slot allocation if the transport is congested (i.e. when | |
1008 | * reconnecting a stream transport or when out of socket write | |
1009 | * buffer space). | |
1010 | */ | |
1011 | if (xprt_lock_write(xprt, task)) { | |
1012 | xprt_alloc_slot(xprt, task); | |
1013 | xprt_release_write(xprt, task); | |
1014 | } | |
1da177e4 | 1015 | } |
f39c1bfb | 1016 | EXPORT_SYMBOL_GPL(xprt_lock_and_alloc_slot); |
1da177e4 | 1017 | |
ee5ebe85 TM |
1018 | static void xprt_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *req) |
1019 | { | |
ee5ebe85 | 1020 | spin_lock(&xprt->reserve_lock); |
c25573b5 TM |
1021 | if (!xprt_dynamic_free_slot(xprt, req)) { |
1022 | memset(req, 0, sizeof(*req)); /* mark unused */ | |
1023 | list_add(&req->rq_list, &xprt->free); | |
1024 | } | |
ee5ebe85 TM |
1025 | rpc_wake_up_next(&xprt->backlog); |
1026 | spin_unlock(&xprt->reserve_lock); | |
1027 | } | |
1028 | ||
21de0a95 TM |
1029 | static void xprt_free_all_slots(struct rpc_xprt *xprt) |
1030 | { | |
1031 | struct rpc_rqst *req; | |
1032 | while (!list_empty(&xprt->free)) { | |
1033 | req = list_first_entry(&xprt->free, struct rpc_rqst, rq_list); | |
1034 | list_del(&req->rq_list); | |
1035 | kfree(req); | |
1036 | } | |
1037 | } | |
1038 | ||
d9ba131d TM |
1039 | struct rpc_xprt *xprt_alloc(struct net *net, size_t size, |
1040 | unsigned int num_prealloc, | |
1041 | unsigned int max_alloc) | |
bd1722d4 PE |
1042 | { |
1043 | struct rpc_xprt *xprt; | |
21de0a95 TM |
1044 | struct rpc_rqst *req; |
1045 | int i; | |
bd1722d4 PE |
1046 | |
1047 | xprt = kzalloc(size, GFP_KERNEL); | |
1048 | if (xprt == NULL) | |
1049 | goto out; | |
1050 | ||
21de0a95 TM |
1051 | xprt_init(xprt, net); |
1052 | ||
1053 | for (i = 0; i < num_prealloc; i++) { | |
1054 | req = kzalloc(sizeof(struct rpc_rqst), GFP_KERNEL); | |
1055 | if (!req) | |
1056 | break; | |
1057 | list_add(&req->rq_list, &xprt->free); | |
1058 | } | |
1059 | if (i < num_prealloc) | |
bd1722d4 | 1060 | goto out_free; |
d9ba131d TM |
1061 | if (max_alloc > num_prealloc) |
1062 | xprt->max_reqs = max_alloc; | |
1063 | else | |
1064 | xprt->max_reqs = num_prealloc; | |
1065 | xprt->min_reqs = num_prealloc; | |
1066 | atomic_set(&xprt->num_reqs, num_prealloc); | |
bd1722d4 PE |
1067 | |
1068 | return xprt; | |
1069 | ||
1070 | out_free: | |
21de0a95 | 1071 | xprt_free(xprt); |
bd1722d4 PE |
1072 | out: |
1073 | return NULL; | |
1074 | } | |
1075 | EXPORT_SYMBOL_GPL(xprt_alloc); | |
1076 | ||
e204e621 PE |
1077 | void xprt_free(struct rpc_xprt *xprt) |
1078 | { | |
37aa2133 | 1079 | put_net(xprt->xprt_net); |
21de0a95 | 1080 | xprt_free_all_slots(xprt); |
e204e621 PE |
1081 | kfree(xprt); |
1082 | } | |
1083 | EXPORT_SYMBOL_GPL(xprt_free); | |
1084 | ||
9903cd1c CL |
1085 | /** |
1086 | * xprt_reserve - allocate an RPC request slot | |
1087 | * @task: RPC task requesting a slot allocation | |
1088 | * | |
1089 | * If no more slots are available, place the task on the transport's | |
1090 | * backlog queue. | |
1091 | */ | |
1092 | void xprt_reserve(struct rpc_task *task) | |
1da177e4 LT |
1093 | { |
1094 | struct rpc_xprt *xprt = task->tk_xprt; | |
1095 | ||
43cedbf0 TM |
1096 | task->tk_status = 0; |
1097 | if (task->tk_rqstp != NULL) | |
1098 | return; | |
1099 | ||
43cedbf0 TM |
1100 | task->tk_timeout = 0; |
1101 | task->tk_status = -EAGAIN; | |
f39c1bfb | 1102 | xprt->ops->alloc_slot(xprt, task); |
1da177e4 LT |
1103 | } |
1104 | ||
d8ed029d | 1105 | static inline __be32 xprt_alloc_xid(struct rpc_xprt *xprt) |
1da177e4 | 1106 | { |
0eae88f3 | 1107 | return (__force __be32)xprt->xid++; |
1da177e4 LT |
1108 | } |
1109 | ||
1110 | static inline void xprt_init_xid(struct rpc_xprt *xprt) | |
1111 | { | |
bf3fcf89 | 1112 | xprt->xid = net_random(); |
1da177e4 LT |
1113 | } |
1114 | ||
9903cd1c | 1115 | static void xprt_request_init(struct rpc_task *task, struct rpc_xprt *xprt) |
1da177e4 LT |
1116 | { |
1117 | struct rpc_rqst *req = task->tk_rqstp; | |
1118 | ||
d9ba131d | 1119 | INIT_LIST_HEAD(&req->rq_list); |
ba7392bb | 1120 | req->rq_timeout = task->tk_client->cl_timeout->to_initval; |
1da177e4 LT |
1121 | req->rq_task = task; |
1122 | req->rq_xprt = xprt; | |
02107148 | 1123 | req->rq_buffer = NULL; |
1da177e4 | 1124 | req->rq_xid = xprt_alloc_xid(xprt); |
ead5e1c2 | 1125 | req->rq_release_snd_buf = NULL; |
da45828e | 1126 | xprt_reset_majortimeo(req); |
46121cf7 | 1127 | dprintk("RPC: %5u reserved req %p xid %08x\n", task->tk_pid, |
1da177e4 LT |
1128 | req, ntohl(req->rq_xid)); |
1129 | } | |
1130 | ||
9903cd1c CL |
1131 | /** |
1132 | * xprt_release - release an RPC request slot | |
1133 | * @task: task which is finished with the slot | |
1134 | * | |
1da177e4 | 1135 | */ |
9903cd1c | 1136 | void xprt_release(struct rpc_task *task) |
1da177e4 | 1137 | { |
55ae1aab | 1138 | struct rpc_xprt *xprt; |
1da177e4 LT |
1139 | struct rpc_rqst *req; |
1140 | ||
1141 | if (!(req = task->tk_rqstp)) | |
1142 | return; | |
55ae1aab | 1143 | |
55ae1aab | 1144 | xprt = req->rq_xprt; |
0a702195 WAA |
1145 | if (task->tk_ops->rpc_count_stats != NULL) |
1146 | task->tk_ops->rpc_count_stats(task, task->tk_calldata); | |
1147 | else if (task->tk_client) | |
1148 | rpc_count_iostats(task, task->tk_client->cl_metrics); | |
4a0f8c04 | 1149 | spin_lock_bh(&xprt->transport_lock); |
49e9a890 | 1150 | xprt->ops->release_xprt(xprt, task); |
a58dd398 CL |
1151 | if (xprt->ops->release_request) |
1152 | xprt->ops->release_request(task); | |
1da177e4 LT |
1153 | if (!list_empty(&req->rq_list)) |
1154 | list_del(&req->rq_list); | |
1155 | xprt->last_used = jiffies; | |
4cfc7e60 | 1156 | if (list_empty(&xprt->recv) && xprt_has_timer(xprt)) |
a246b010 | 1157 | mod_timer(&xprt->timer, |
03bf4b70 | 1158 | xprt->last_used + xprt->idle_timeout); |
4a0f8c04 | 1159 | spin_unlock_bh(&xprt->transport_lock); |
ee5ebe85 | 1160 | if (req->rq_buffer) |
55ae1aab | 1161 | xprt->ops->buf_free(req->rq_buffer); |
a17c2153 TM |
1162 | if (req->rq_cred != NULL) |
1163 | put_rpccred(req->rq_cred); | |
1da177e4 | 1164 | task->tk_rqstp = NULL; |
ead5e1c2 BF |
1165 | if (req->rq_release_snd_buf) |
1166 | req->rq_release_snd_buf(req); | |
55ae1aab | 1167 | |
46121cf7 | 1168 | dprintk("RPC: %5u release request %p\n", task->tk_pid, req); |
ee5ebe85 TM |
1169 | if (likely(!bc_prealloc(req))) |
1170 | xprt_free_slot(xprt, req); | |
1171 | else | |
c9acb42e | 1172 | xprt_free_bc_request(req); |
1da177e4 LT |
1173 | } |
1174 | ||
21de0a95 | 1175 | static void xprt_init(struct rpc_xprt *xprt, struct net *net) |
c2866763 | 1176 | { |
21de0a95 | 1177 | atomic_set(&xprt->count, 1); |
c2866763 CL |
1178 | |
1179 | spin_lock_init(&xprt->transport_lock); | |
1180 | spin_lock_init(&xprt->reserve_lock); | |
1181 | ||
1182 | INIT_LIST_HEAD(&xprt->free); | |
1183 | INIT_LIST_HEAD(&xprt->recv); | |
9e00abc3 | 1184 | #if defined(CONFIG_SUNRPC_BACKCHANNEL) |
f9acac1a RL |
1185 | spin_lock_init(&xprt->bc_pa_lock); |
1186 | INIT_LIST_HEAD(&xprt->bc_pa_list); | |
9e00abc3 | 1187 | #endif /* CONFIG_SUNRPC_BACKCHANNEL */ |
f9acac1a | 1188 | |
c2866763 CL |
1189 | xprt->last_used = jiffies; |
1190 | xprt->cwnd = RPC_INITCWND; | |
a509050b | 1191 | xprt->bind_index = 0; |
c2866763 CL |
1192 | |
1193 | rpc_init_wait_queue(&xprt->binding, "xprt_binding"); | |
1194 | rpc_init_wait_queue(&xprt->pending, "xprt_pending"); | |
34006cee | 1195 | rpc_init_priority_wait_queue(&xprt->sending, "xprt_sending"); |
c2866763 CL |
1196 | rpc_init_priority_wait_queue(&xprt->backlog, "xprt_backlog"); |
1197 | ||
c2866763 CL |
1198 | xprt_init_xid(xprt); |
1199 | ||
21de0a95 | 1200 | xprt->xprt_net = get_net(net); |
8d9266ff TM |
1201 | } |
1202 | ||
1203 | /** | |
1204 | * xprt_create_transport - create an RPC transport | |
1205 | * @args: rpc transport creation arguments | |
1206 | * | |
1207 | */ | |
1208 | struct rpc_xprt *xprt_create_transport(struct xprt_create *args) | |
1209 | { | |
1210 | struct rpc_xprt *xprt; | |
1211 | struct xprt_class *t; | |
1212 | ||
1213 | spin_lock(&xprt_list_lock); | |
1214 | list_for_each_entry(t, &xprt_list, list) { | |
1215 | if (t->ident == args->ident) { | |
1216 | spin_unlock(&xprt_list_lock); | |
1217 | goto found; | |
1218 | } | |
1219 | } | |
1220 | spin_unlock(&xprt_list_lock); | |
1221 | printk(KERN_ERR "RPC: transport (%d) not supported\n", args->ident); | |
1222 | return ERR_PTR(-EIO); | |
1223 | ||
1224 | found: | |
1225 | xprt = t->setup(args); | |
1226 | if (IS_ERR(xprt)) { | |
1227 | dprintk("RPC: xprt_create_transport: failed, %ld\n", | |
1228 | -PTR_ERR(xprt)); | |
21de0a95 | 1229 | goto out; |
8d9266ff | 1230 | } |
21de0a95 TM |
1231 | INIT_WORK(&xprt->task_cleanup, xprt_autoclose); |
1232 | if (xprt_has_timer(xprt)) | |
1233 | setup_timer(&xprt->timer, xprt_init_autodisconnect, | |
1234 | (unsigned long)xprt); | |
1235 | else | |
1236 | init_timer(&xprt->timer); | |
4e0038b6 TM |
1237 | |
1238 | if (strlen(args->servername) > RPC_MAXNETNAMELEN) { | |
1239 | xprt_destroy(xprt); | |
1240 | return ERR_PTR(-EINVAL); | |
1241 | } | |
1242 | xprt->servername = kstrdup(args->servername, GFP_KERNEL); | |
1243 | if (xprt->servername == NULL) { | |
1244 | xprt_destroy(xprt); | |
1245 | return ERR_PTR(-ENOMEM); | |
1246 | } | |
1247 | ||
46121cf7 | 1248 | dprintk("RPC: created transport %p with %u slots\n", xprt, |
c2866763 | 1249 | xprt->max_reqs); |
21de0a95 | 1250 | out: |
c2866763 CL |
1251 | return xprt; |
1252 | } | |
1253 | ||
9903cd1c CL |
1254 | /** |
1255 | * xprt_destroy - destroy an RPC transport, killing off all requests. | |
a8de240a | 1256 | * @xprt: transport to destroy |
9903cd1c | 1257 | * |
1da177e4 | 1258 | */ |
a8de240a | 1259 | static void xprt_destroy(struct rpc_xprt *xprt) |
1da177e4 | 1260 | { |
46121cf7 | 1261 | dprintk("RPC: destroying transport %p\n", xprt); |
0065db32 | 1262 | del_timer_sync(&xprt->timer); |
c8541ecd | 1263 | |
f6a1cc89 TM |
1264 | rpc_destroy_wait_queue(&xprt->binding); |
1265 | rpc_destroy_wait_queue(&xprt->pending); | |
1266 | rpc_destroy_wait_queue(&xprt->sending); | |
f6a1cc89 | 1267 | rpc_destroy_wait_queue(&xprt->backlog); |
c3ae62ae | 1268 | cancel_work_sync(&xprt->task_cleanup); |
4e0038b6 | 1269 | kfree(xprt->servername); |
c8541ecd CL |
1270 | /* |
1271 | * Tear down transport state and free the rpc_xprt | |
1272 | */ | |
a246b010 | 1273 | xprt->ops->destroy(xprt); |
6b6ca86b | 1274 | } |
1da177e4 | 1275 | |
6b6ca86b TM |
1276 | /** |
1277 | * xprt_put - release a reference to an RPC transport. | |
1278 | * @xprt: pointer to the transport | |
1279 | * | |
1280 | */ | |
1281 | void xprt_put(struct rpc_xprt *xprt) | |
1282 | { | |
a8de240a TM |
1283 | if (atomic_dec_and_test(&xprt->count)) |
1284 | xprt_destroy(xprt); | |
6b6ca86b TM |
1285 | } |
1286 | ||
1287 | /** | |
1288 | * xprt_get - return a reference to an RPC transport. | |
1289 | * @xprt: pointer to the transport | |
1290 | * | |
1291 | */ | |
1292 | struct rpc_xprt *xprt_get(struct rpc_xprt *xprt) | |
1293 | { | |
a8de240a TM |
1294 | if (atomic_inc_not_zero(&xprt->count)) |
1295 | return xprt; | |
1296 | return NULL; | |
1da177e4 | 1297 | } |