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> |
fda1bfef | 51 | #include <linux/rcupdate.h> |
1da177e4 | 52 | |
3705ad64 JL |
53 | #include <trace/events/sunrpc.h> |
54 | ||
55ae1aab RL |
55 | #include "sunrpc.h" |
56 | ||
1da177e4 LT |
57 | /* |
58 | * Local variables | |
59 | */ | |
60 | ||
f895b252 | 61 | #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) |
1da177e4 LT |
62 | # define RPCDBG_FACILITY RPCDBG_XPRT |
63 | #endif | |
64 | ||
1da177e4 LT |
65 | /* |
66 | * Local functions | |
67 | */ | |
21de0a95 | 68 | static void xprt_init(struct rpc_xprt *xprt, struct net *net); |
37ac86c3 | 69 | static __be32 xprt_alloc_xid(struct rpc_xprt *xprt); |
4e0038b6 | 70 | static void xprt_destroy(struct rpc_xprt *xprt); |
1da177e4 | 71 | |
5ba03e82 | 72 | static DEFINE_SPINLOCK(xprt_list_lock); |
81c098af TT |
73 | static LIST_HEAD(xprt_list); |
74 | ||
81c098af TT |
75 | /** |
76 | * xprt_register_transport - register a transport implementation | |
77 | * @transport: transport to register | |
78 | * | |
79 | * If a transport implementation is loaded as a kernel module, it can | |
80 | * call this interface to make itself known to the RPC client. | |
81 | * | |
82 | * Returns: | |
83 | * 0: transport successfully registered | |
84 | * -EEXIST: transport already registered | |
85 | * -EINVAL: transport module being unloaded | |
86 | */ | |
87 | int xprt_register_transport(struct xprt_class *transport) | |
88 | { | |
89 | struct xprt_class *t; | |
90 | int result; | |
91 | ||
92 | result = -EEXIST; | |
93 | spin_lock(&xprt_list_lock); | |
94 | list_for_each_entry(t, &xprt_list, list) { | |
95 | /* don't register the same transport class twice */ | |
4fa016eb | 96 | if (t->ident == transport->ident) |
81c098af TT |
97 | goto out; |
98 | } | |
99 | ||
c9f6cde6 DL |
100 | list_add_tail(&transport->list, &xprt_list); |
101 | printk(KERN_INFO "RPC: Registered %s transport module.\n", | |
102 | transport->name); | |
103 | result = 0; | |
81c098af TT |
104 | |
105 | out: | |
106 | spin_unlock(&xprt_list_lock); | |
107 | return result; | |
108 | } | |
109 | EXPORT_SYMBOL_GPL(xprt_register_transport); | |
110 | ||
111 | /** | |
112 | * xprt_unregister_transport - unregister a transport implementation | |
65b6e42c | 113 | * @transport: transport to unregister |
81c098af TT |
114 | * |
115 | * Returns: | |
116 | * 0: transport successfully unregistered | |
117 | * -ENOENT: transport never registered | |
118 | */ | |
119 | int xprt_unregister_transport(struct xprt_class *transport) | |
120 | { | |
121 | struct xprt_class *t; | |
122 | int result; | |
123 | ||
124 | result = 0; | |
125 | spin_lock(&xprt_list_lock); | |
126 | list_for_each_entry(t, &xprt_list, list) { | |
127 | if (t == transport) { | |
128 | printk(KERN_INFO | |
129 | "RPC: Unregistered %s transport module.\n", | |
130 | transport->name); | |
131 | list_del_init(&transport->list); | |
81c098af TT |
132 | goto out; |
133 | } | |
134 | } | |
135 | result = -ENOENT; | |
136 | ||
137 | out: | |
138 | spin_unlock(&xprt_list_lock); | |
139 | return result; | |
140 | } | |
141 | EXPORT_SYMBOL_GPL(xprt_unregister_transport); | |
142 | ||
441e3e24 TT |
143 | /** |
144 | * xprt_load_transport - load a transport implementation | |
145 | * @transport_name: transport to load | |
146 | * | |
147 | * Returns: | |
148 | * 0: transport successfully loaded | |
149 | * -ENOENT: transport module not available | |
150 | */ | |
151 | int xprt_load_transport(const char *transport_name) | |
152 | { | |
153 | struct xprt_class *t; | |
441e3e24 TT |
154 | int result; |
155 | ||
156 | result = 0; | |
157 | spin_lock(&xprt_list_lock); | |
158 | list_for_each_entry(t, &xprt_list, list) { | |
159 | if (strcmp(t->name, transport_name) == 0) { | |
160 | spin_unlock(&xprt_list_lock); | |
161 | goto out; | |
162 | } | |
163 | } | |
164 | spin_unlock(&xprt_list_lock); | |
ef7ffe8f | 165 | result = request_module("xprt%s", transport_name); |
441e3e24 TT |
166 | out: |
167 | return result; | |
168 | } | |
169 | EXPORT_SYMBOL_GPL(xprt_load_transport); | |
170 | ||
c544577d TM |
171 | static void xprt_clear_locked(struct rpc_xprt *xprt) |
172 | { | |
173 | xprt->snd_task = NULL; | |
174 | if (!test_bit(XPRT_CLOSE_WAIT, &xprt->state)) { | |
175 | smp_mb__before_atomic(); | |
176 | clear_bit(XPRT_LOCKED, &xprt->state); | |
177 | smp_mb__after_atomic(); | |
178 | } else | |
179 | queue_work(xprtiod_workqueue, &xprt->task_cleanup); | |
180 | } | |
181 | ||
12a80469 CL |
182 | /** |
183 | * xprt_reserve_xprt - serialize write access to transports | |
184 | * @task: task that is requesting access to the transport | |
177c27bf | 185 | * @xprt: pointer to the target transport |
12a80469 CL |
186 | * |
187 | * This prevents mixing the payload of separate requests, and prevents | |
188 | * transport connects from colliding with writes. No congestion control | |
189 | * is provided. | |
190 | */ | |
43cedbf0 | 191 | int xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task) |
12a80469 | 192 | { |
12a80469 CL |
193 | struct rpc_rqst *req = task->tk_rqstp; |
194 | ||
195 | if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) { | |
196 | if (task == xprt->snd_task) | |
197 | return 1; | |
12a80469 CL |
198 | goto out_sleep; |
199 | } | |
c544577d TM |
200 | if (test_bit(XPRT_WRITE_SPACE, &xprt->state)) |
201 | goto out_unlock; | |
12a80469 | 202 | xprt->snd_task = task; |
4d4a76f3 | 203 | |
12a80469 CL |
204 | return 1; |
205 | ||
c544577d TM |
206 | out_unlock: |
207 | xprt_clear_locked(xprt); | |
12a80469 | 208 | out_sleep: |
46121cf7 | 209 | dprintk("RPC: %5u failed to lock transport %p\n", |
12a80469 | 210 | task->tk_pid, xprt); |
f05d54ec | 211 | task->tk_timeout = RPC_IS_SOFT(task) ? req->rq_timeout : 0; |
12a80469 | 212 | task->tk_status = -EAGAIN; |
79c99152 | 213 | rpc_sleep_on(&xprt->sending, task, NULL); |
12a80469 CL |
214 | return 0; |
215 | } | |
12444809 | 216 | EXPORT_SYMBOL_GPL(xprt_reserve_xprt); |
12a80469 | 217 | |
75891f50 TM |
218 | static bool |
219 | xprt_need_congestion_window_wait(struct rpc_xprt *xprt) | |
220 | { | |
221 | return test_bit(XPRT_CWND_WAIT, &xprt->state); | |
222 | } | |
223 | ||
224 | static void | |
225 | xprt_set_congestion_window_wait(struct rpc_xprt *xprt) | |
226 | { | |
227 | if (!list_empty(&xprt->xmit_queue)) { | |
228 | /* Peek at head of queue to see if it can make progress */ | |
229 | if (list_first_entry(&xprt->xmit_queue, struct rpc_rqst, | |
230 | rq_xmit)->rq_cong) | |
231 | return; | |
232 | } | |
233 | set_bit(XPRT_CWND_WAIT, &xprt->state); | |
234 | } | |
235 | ||
236 | static void | |
237 | xprt_test_and_clear_congestion_window_wait(struct rpc_xprt *xprt) | |
238 | { | |
239 | if (!RPCXPRT_CONGESTED(xprt)) | |
240 | clear_bit(XPRT_CWND_WAIT, &xprt->state); | |
241 | } | |
242 | ||
1da177e4 | 243 | /* |
12a80469 CL |
244 | * xprt_reserve_xprt_cong - serialize write access to transports |
245 | * @task: task that is requesting access to the transport | |
246 | * | |
247 | * Same as xprt_reserve_xprt, but Van Jacobson congestion control is | |
248 | * integrated into the decision of whether a request is allowed to be | |
249 | * woken up and given access to the transport. | |
75891f50 | 250 | * Note that the lock is only granted if we know there are free slots. |
1da177e4 | 251 | */ |
43cedbf0 | 252 | int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task) |
1da177e4 LT |
253 | { |
254 | struct rpc_rqst *req = task->tk_rqstp; | |
255 | ||
2226feb6 | 256 | if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) { |
1da177e4 LT |
257 | if (task == xprt->snd_task) |
258 | return 1; | |
1da177e4 LT |
259 | goto out_sleep; |
260 | } | |
43cedbf0 TM |
261 | if (req == NULL) { |
262 | xprt->snd_task = task; | |
263 | return 1; | |
264 | } | |
c544577d TM |
265 | if (test_bit(XPRT_WRITE_SPACE, &xprt->state)) |
266 | goto out_unlock; | |
75891f50 | 267 | if (!xprt_need_congestion_window_wait(xprt)) { |
1da177e4 | 268 | xprt->snd_task = task; |
1da177e4 LT |
269 | return 1; |
270 | } | |
c544577d | 271 | out_unlock: |
632e3bdc | 272 | xprt_clear_locked(xprt); |
1da177e4 | 273 | out_sleep: |
46121cf7 | 274 | dprintk("RPC: %5u failed to lock transport %p\n", task->tk_pid, xprt); |
f05d54ec | 275 | task->tk_timeout = RPC_IS_SOFT(task) ? req->rq_timeout : 0; |
1da177e4 | 276 | task->tk_status = -EAGAIN; |
79c99152 | 277 | rpc_sleep_on(&xprt->sending, task, NULL); |
1da177e4 LT |
278 | return 0; |
279 | } | |
12444809 | 280 | EXPORT_SYMBOL_GPL(xprt_reserve_xprt_cong); |
1da177e4 | 281 | |
12a80469 | 282 | static inline int xprt_lock_write(struct rpc_xprt *xprt, struct rpc_task *task) |
1da177e4 LT |
283 | { |
284 | int retval; | |
285 | ||
bd79bc57 TM |
286 | if (test_bit(XPRT_LOCKED, &xprt->state) && xprt->snd_task == task) |
287 | return 1; | |
4a0f8c04 | 288 | spin_lock_bh(&xprt->transport_lock); |
43cedbf0 | 289 | retval = xprt->ops->reserve_xprt(xprt, task); |
4a0f8c04 | 290 | spin_unlock_bh(&xprt->transport_lock); |
1da177e4 LT |
291 | return retval; |
292 | } | |
293 | ||
961a828d | 294 | static bool __xprt_lock_write_func(struct rpc_task *task, void *data) |
49e9a890 | 295 | { |
961a828d | 296 | struct rpc_xprt *xprt = data; |
49e9a890 | 297 | |
49e9a890 | 298 | xprt->snd_task = task; |
961a828d TM |
299 | return true; |
300 | } | |
49e9a890 | 301 | |
961a828d TM |
302 | static void __xprt_lock_write_next(struct rpc_xprt *xprt) |
303 | { | |
304 | if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) | |
305 | return; | |
c544577d TM |
306 | if (test_bit(XPRT_WRITE_SPACE, &xprt->state)) |
307 | goto out_unlock; | |
f1dc237c TM |
308 | if (rpc_wake_up_first_on_wq(xprtiod_workqueue, &xprt->sending, |
309 | __xprt_lock_write_func, xprt)) | |
961a828d | 310 | return; |
c544577d | 311 | out_unlock: |
632e3bdc | 312 | xprt_clear_locked(xprt); |
49e9a890 CL |
313 | } |
314 | ||
961a828d TM |
315 | static void __xprt_lock_write_next_cong(struct rpc_xprt *xprt) |
316 | { | |
317 | if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) | |
318 | return; | |
c544577d TM |
319 | if (test_bit(XPRT_WRITE_SPACE, &xprt->state)) |
320 | goto out_unlock; | |
75891f50 | 321 | if (xprt_need_congestion_window_wait(xprt)) |
961a828d | 322 | goto out_unlock; |
f1dc237c | 323 | if (rpc_wake_up_first_on_wq(xprtiod_workqueue, &xprt->sending, |
75891f50 | 324 | __xprt_lock_write_func, xprt)) |
961a828d | 325 | return; |
1da177e4 | 326 | out_unlock: |
632e3bdc | 327 | xprt_clear_locked(xprt); |
1da177e4 LT |
328 | } |
329 | ||
49e9a890 CL |
330 | /** |
331 | * xprt_release_xprt - allow other requests to use a transport | |
332 | * @xprt: transport with other tasks potentially waiting | |
333 | * @task: task that is releasing access to the transport | |
334 | * | |
335 | * Note that "task" can be NULL. No congestion control is provided. | |
1da177e4 | 336 | */ |
49e9a890 | 337 | void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task) |
1da177e4 LT |
338 | { |
339 | if (xprt->snd_task == task) { | |
632e3bdc | 340 | xprt_clear_locked(xprt); |
1da177e4 LT |
341 | __xprt_lock_write_next(xprt); |
342 | } | |
343 | } | |
12444809 | 344 | EXPORT_SYMBOL_GPL(xprt_release_xprt); |
1da177e4 | 345 | |
49e9a890 CL |
346 | /** |
347 | * xprt_release_xprt_cong - allow other requests to use a transport | |
348 | * @xprt: transport with other tasks potentially waiting | |
349 | * @task: task that is releasing access to the transport | |
350 | * | |
351 | * Note that "task" can be NULL. Another task is awoken to use the | |
352 | * transport if the transport's congestion window allows it. | |
353 | */ | |
354 | void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task) | |
355 | { | |
356 | if (xprt->snd_task == task) { | |
632e3bdc | 357 | xprt_clear_locked(xprt); |
49e9a890 CL |
358 | __xprt_lock_write_next_cong(xprt); |
359 | } | |
360 | } | |
12444809 | 361 | EXPORT_SYMBOL_GPL(xprt_release_xprt_cong); |
49e9a890 CL |
362 | |
363 | static inline void xprt_release_write(struct rpc_xprt *xprt, struct rpc_task *task) | |
1da177e4 | 364 | { |
bd79bc57 TM |
365 | if (xprt->snd_task != task) |
366 | return; | |
4a0f8c04 | 367 | spin_lock_bh(&xprt->transport_lock); |
49e9a890 | 368 | xprt->ops->release_xprt(xprt, task); |
4a0f8c04 | 369 | spin_unlock_bh(&xprt->transport_lock); |
1da177e4 LT |
370 | } |
371 | ||
1da177e4 LT |
372 | /* |
373 | * Van Jacobson congestion avoidance. Check if the congestion window | |
374 | * overflowed. Put the task to sleep if this is the case. | |
375 | */ | |
376 | static int | |
75891f50 | 377 | __xprt_get_cong(struct rpc_xprt *xprt, struct rpc_rqst *req) |
1da177e4 | 378 | { |
1da177e4 LT |
379 | if (req->rq_cong) |
380 | return 1; | |
46121cf7 | 381 | dprintk("RPC: %5u xprt_cwnd_limited cong = %lu cwnd = %lu\n", |
75891f50 TM |
382 | req->rq_task->tk_pid, xprt->cong, xprt->cwnd); |
383 | if (RPCXPRT_CONGESTED(xprt)) { | |
384 | xprt_set_congestion_window_wait(xprt); | |
1da177e4 | 385 | return 0; |
75891f50 | 386 | } |
1da177e4 LT |
387 | req->rq_cong = 1; |
388 | xprt->cong += RPC_CWNDSCALE; | |
389 | return 1; | |
390 | } | |
391 | ||
392 | /* | |
393 | * Adjust the congestion window, and wake up the next task | |
394 | * that has been sleeping due to congestion | |
395 | */ | |
396 | static void | |
397 | __xprt_put_cong(struct rpc_xprt *xprt, struct rpc_rqst *req) | |
398 | { | |
399 | if (!req->rq_cong) | |
400 | return; | |
401 | req->rq_cong = 0; | |
402 | xprt->cong -= RPC_CWNDSCALE; | |
75891f50 | 403 | xprt_test_and_clear_congestion_window_wait(xprt); |
49e9a890 | 404 | __xprt_lock_write_next_cong(xprt); |
1da177e4 LT |
405 | } |
406 | ||
75891f50 TM |
407 | /** |
408 | * xprt_request_get_cong - Request congestion control credits | |
409 | * @xprt: pointer to transport | |
410 | * @req: pointer to RPC request | |
411 | * | |
412 | * Useful for transports that require congestion control. | |
413 | */ | |
414 | bool | |
415 | xprt_request_get_cong(struct rpc_xprt *xprt, struct rpc_rqst *req) | |
416 | { | |
417 | bool ret = false; | |
418 | ||
419 | if (req->rq_cong) | |
420 | return true; | |
421 | spin_lock_bh(&xprt->transport_lock); | |
422 | ret = __xprt_get_cong(xprt, req) != 0; | |
423 | spin_unlock_bh(&xprt->transport_lock); | |
424 | return ret; | |
425 | } | |
426 | EXPORT_SYMBOL_GPL(xprt_request_get_cong); | |
427 | ||
a58dd398 CL |
428 | /** |
429 | * xprt_release_rqst_cong - housekeeping when request is complete | |
430 | * @task: RPC request that recently completed | |
431 | * | |
432 | * Useful for transports that require congestion control. | |
433 | */ | |
434 | void xprt_release_rqst_cong(struct rpc_task *task) | |
435 | { | |
a4f0835c TM |
436 | struct rpc_rqst *req = task->tk_rqstp; |
437 | ||
438 | __xprt_put_cong(req->rq_xprt, req); | |
a58dd398 | 439 | } |
12444809 | 440 | EXPORT_SYMBOL_GPL(xprt_release_rqst_cong); |
a58dd398 | 441 | |
75891f50 TM |
442 | /* |
443 | * Clear the congestion window wait flag and wake up the next | |
444 | * entry on xprt->sending | |
445 | */ | |
446 | static void | |
447 | xprt_clear_congestion_window_wait(struct rpc_xprt *xprt) | |
448 | { | |
449 | if (test_and_clear_bit(XPRT_CWND_WAIT, &xprt->state)) { | |
450 | spin_lock_bh(&xprt->transport_lock); | |
451 | __xprt_lock_write_next_cong(xprt); | |
452 | spin_unlock_bh(&xprt->transport_lock); | |
453 | } | |
454 | } | |
455 | ||
46c0ee8b CL |
456 | /** |
457 | * xprt_adjust_cwnd - adjust transport congestion window | |
6a24dfb6 | 458 | * @xprt: pointer to xprt |
46c0ee8b CL |
459 | * @task: recently completed RPC request used to adjust window |
460 | * @result: result code of completed RPC request | |
461 | * | |
4f4cf5ad CL |
462 | * The transport code maintains an estimate on the maximum number of out- |
463 | * standing RPC requests, using a smoothed version of the congestion | |
464 | * avoidance implemented in 44BSD. This is basically the Van Jacobson | |
465 | * congestion algorithm: If a retransmit occurs, the congestion window is | |
466 | * halved; otherwise, it is incremented by 1/cwnd when | |
467 | * | |
468 | * - a reply is received and | |
469 | * - a full number of requests are outstanding and | |
470 | * - the congestion window hasn't been updated recently. | |
1da177e4 | 471 | */ |
6a24dfb6 | 472 | void xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result) |
1da177e4 | 473 | { |
46c0ee8b | 474 | struct rpc_rqst *req = task->tk_rqstp; |
46c0ee8b | 475 | unsigned long cwnd = xprt->cwnd; |
1da177e4 | 476 | |
1da177e4 LT |
477 | if (result >= 0 && cwnd <= xprt->cong) { |
478 | /* The (cwnd >> 1) term makes sure | |
479 | * the result gets rounded properly. */ | |
480 | cwnd += (RPC_CWNDSCALE * RPC_CWNDSCALE + (cwnd >> 1)) / cwnd; | |
481 | if (cwnd > RPC_MAXCWND(xprt)) | |
482 | cwnd = RPC_MAXCWND(xprt); | |
49e9a890 | 483 | __xprt_lock_write_next_cong(xprt); |
1da177e4 LT |
484 | } else if (result == -ETIMEDOUT) { |
485 | cwnd >>= 1; | |
486 | if (cwnd < RPC_CWNDSCALE) | |
487 | cwnd = RPC_CWNDSCALE; | |
488 | } | |
46121cf7 | 489 | dprintk("RPC: cong %ld, cwnd was %ld, now %ld\n", |
1da177e4 LT |
490 | xprt->cong, xprt->cwnd, cwnd); |
491 | xprt->cwnd = cwnd; | |
46c0ee8b | 492 | __xprt_put_cong(xprt, req); |
1da177e4 | 493 | } |
12444809 | 494 | EXPORT_SYMBOL_GPL(xprt_adjust_cwnd); |
1da177e4 | 495 | |
44fbac22 CL |
496 | /** |
497 | * xprt_wake_pending_tasks - wake all tasks on a transport's pending queue | |
498 | * @xprt: transport with waiting tasks | |
499 | * @status: result code to plant in each task before waking it | |
500 | * | |
501 | */ | |
502 | void xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status) | |
503 | { | |
504 | if (status < 0) | |
505 | rpc_wake_up_status(&xprt->pending, status); | |
506 | else | |
507 | rpc_wake_up(&xprt->pending); | |
508 | } | |
12444809 | 509 | EXPORT_SYMBOL_GPL(xprt_wake_pending_tasks); |
44fbac22 | 510 | |
c7b2cae8 CL |
511 | /** |
512 | * xprt_wait_for_buffer_space - wait for transport output buffer to clear | |
c544577d | 513 | * @xprt: transport |
a9a6b52e TM |
514 | * |
515 | * Note that we only set the timer for the case of RPC_IS_SOFT(), since | |
516 | * we don't in general want to force a socket disconnection due to | |
517 | * an incomplete RPC call transmission. | |
c7b2cae8 | 518 | */ |
c544577d | 519 | void xprt_wait_for_buffer_space(struct rpc_xprt *xprt) |
c7b2cae8 | 520 | { |
c544577d | 521 | set_bit(XPRT_WRITE_SPACE, &xprt->state); |
c7b2cae8 | 522 | } |
12444809 | 523 | EXPORT_SYMBOL_GPL(xprt_wait_for_buffer_space); |
c7b2cae8 | 524 | |
c544577d TM |
525 | static bool |
526 | xprt_clear_write_space_locked(struct rpc_xprt *xprt) | |
527 | { | |
528 | if (test_and_clear_bit(XPRT_WRITE_SPACE, &xprt->state)) { | |
529 | __xprt_lock_write_next(xprt); | |
530 | dprintk("RPC: write space: waking waiting task on " | |
531 | "xprt %p\n", xprt); | |
532 | return true; | |
533 | } | |
534 | return false; | |
535 | } | |
536 | ||
c7b2cae8 CL |
537 | /** |
538 | * xprt_write_space - wake the task waiting for transport output buffer space | |
539 | * @xprt: transport with waiting tasks | |
540 | * | |
541 | * Can be called in a soft IRQ context, so xprt_write_space never sleeps. | |
542 | */ | |
c544577d | 543 | bool xprt_write_space(struct rpc_xprt *xprt) |
c7b2cae8 | 544 | { |
c544577d TM |
545 | bool ret; |
546 | ||
547 | if (!test_bit(XPRT_WRITE_SPACE, &xprt->state)) | |
548 | return false; | |
c7b2cae8 | 549 | spin_lock_bh(&xprt->transport_lock); |
c544577d | 550 | ret = xprt_clear_write_space_locked(xprt); |
c7b2cae8 | 551 | spin_unlock_bh(&xprt->transport_lock); |
c544577d | 552 | return ret; |
c7b2cae8 | 553 | } |
12444809 | 554 | EXPORT_SYMBOL_GPL(xprt_write_space); |
c7b2cae8 | 555 | |
fe3aca29 CL |
556 | /** |
557 | * xprt_set_retrans_timeout_def - set a request's retransmit timeout | |
558 | * @task: task whose timeout is to be set | |
559 | * | |
560 | * Set a request's retransmit timeout based on the transport's | |
561 | * default timeout parameters. Used by transports that don't adjust | |
562 | * the retransmit timeout based on round-trip time estimation. | |
563 | */ | |
564 | void xprt_set_retrans_timeout_def(struct rpc_task *task) | |
565 | { | |
566 | task->tk_timeout = task->tk_rqstp->rq_timeout; | |
567 | } | |
12444809 | 568 | EXPORT_SYMBOL_GPL(xprt_set_retrans_timeout_def); |
fe3aca29 | 569 | |
2c53040f | 570 | /** |
fe3aca29 CL |
571 | * xprt_set_retrans_timeout_rtt - set a request's retransmit timeout |
572 | * @task: task whose timeout is to be set | |
cca5172a | 573 | * |
fe3aca29 CL |
574 | * Set a request's retransmit timeout using the RTT estimator. |
575 | */ | |
576 | void xprt_set_retrans_timeout_rtt(struct rpc_task *task) | |
577 | { | |
578 | int timer = task->tk_msg.rpc_proc->p_timer; | |
ba7392bb TM |
579 | struct rpc_clnt *clnt = task->tk_client; |
580 | struct rpc_rtt *rtt = clnt->cl_rtt; | |
fe3aca29 | 581 | struct rpc_rqst *req = task->tk_rqstp; |
ba7392bb | 582 | unsigned long max_timeout = clnt->cl_timeout->to_maxval; |
fe3aca29 CL |
583 | |
584 | task->tk_timeout = rpc_calc_rto(rtt, timer); | |
585 | task->tk_timeout <<= rpc_ntimeo(rtt, timer) + req->rq_retries; | |
586 | if (task->tk_timeout > max_timeout || task->tk_timeout == 0) | |
587 | task->tk_timeout = max_timeout; | |
588 | } | |
12444809 | 589 | EXPORT_SYMBOL_GPL(xprt_set_retrans_timeout_rtt); |
fe3aca29 | 590 | |
1da177e4 LT |
591 | static void xprt_reset_majortimeo(struct rpc_rqst *req) |
592 | { | |
ba7392bb | 593 | const struct rpc_timeout *to = req->rq_task->tk_client->cl_timeout; |
1da177e4 LT |
594 | |
595 | req->rq_majortimeo = req->rq_timeout; | |
596 | if (to->to_exponential) | |
597 | req->rq_majortimeo <<= to->to_retries; | |
598 | else | |
599 | req->rq_majortimeo += to->to_increment * to->to_retries; | |
600 | if (req->rq_majortimeo > to->to_maxval || req->rq_majortimeo == 0) | |
601 | req->rq_majortimeo = to->to_maxval; | |
602 | req->rq_majortimeo += jiffies; | |
603 | } | |
604 | ||
9903cd1c CL |
605 | /** |
606 | * xprt_adjust_timeout - adjust timeout values for next retransmit | |
607 | * @req: RPC request containing parameters to use for the adjustment | |
608 | * | |
1da177e4 LT |
609 | */ |
610 | int xprt_adjust_timeout(struct rpc_rqst *req) | |
611 | { | |
612 | struct rpc_xprt *xprt = req->rq_xprt; | |
ba7392bb | 613 | const struct rpc_timeout *to = req->rq_task->tk_client->cl_timeout; |
1da177e4 LT |
614 | int status = 0; |
615 | ||
616 | if (time_before(jiffies, req->rq_majortimeo)) { | |
617 | if (to->to_exponential) | |
618 | req->rq_timeout <<= 1; | |
619 | else | |
620 | req->rq_timeout += to->to_increment; | |
621 | if (to->to_maxval && req->rq_timeout >= to->to_maxval) | |
622 | req->rq_timeout = to->to_maxval; | |
623 | req->rq_retries++; | |
1da177e4 LT |
624 | } else { |
625 | req->rq_timeout = to->to_initval; | |
626 | req->rq_retries = 0; | |
627 | xprt_reset_majortimeo(req); | |
628 | /* Reset the RTT counters == "slow start" */ | |
4a0f8c04 | 629 | spin_lock_bh(&xprt->transport_lock); |
1da177e4 | 630 | rpc_init_rtt(req->rq_task->tk_client->cl_rtt, to->to_initval); |
4a0f8c04 | 631 | spin_unlock_bh(&xprt->transport_lock); |
1da177e4 LT |
632 | status = -ETIMEDOUT; |
633 | } | |
634 | ||
635 | if (req->rq_timeout == 0) { | |
636 | printk(KERN_WARNING "xprt_adjust_timeout: rq_timeout = 0!\n"); | |
637 | req->rq_timeout = 5 * HZ; | |
638 | } | |
639 | return status; | |
640 | } | |
641 | ||
65f27f38 | 642 | static void xprt_autoclose(struct work_struct *work) |
1da177e4 | 643 | { |
65f27f38 DH |
644 | struct rpc_xprt *xprt = |
645 | container_of(work, struct rpc_xprt, task_cleanup); | |
1da177e4 | 646 | |
66af1e55 | 647 | clear_bit(XPRT_CLOSE_WAIT, &xprt->state); |
4876cc77 | 648 | xprt->ops->close(xprt); |
1da177e4 | 649 | xprt_release_write(xprt, NULL); |
79234c3d | 650 | wake_up_bit(&xprt->state, XPRT_LOCKED); |
1da177e4 LT |
651 | } |
652 | ||
9903cd1c | 653 | /** |
62da3b24 | 654 | * xprt_disconnect_done - mark a transport as disconnected |
9903cd1c CL |
655 | * @xprt: transport to flag for disconnect |
656 | * | |
1da177e4 | 657 | */ |
62da3b24 | 658 | void xprt_disconnect_done(struct rpc_xprt *xprt) |
1da177e4 | 659 | { |
46121cf7 | 660 | dprintk("RPC: disconnected transport %p\n", xprt); |
4a0f8c04 | 661 | spin_lock_bh(&xprt->transport_lock); |
1da177e4 | 662 | xprt_clear_connected(xprt); |
c544577d | 663 | xprt_clear_write_space_locked(xprt); |
2a491991 | 664 | xprt_wake_pending_tasks(xprt, -EAGAIN); |
4a0f8c04 | 665 | spin_unlock_bh(&xprt->transport_lock); |
1da177e4 | 666 | } |
62da3b24 | 667 | EXPORT_SYMBOL_GPL(xprt_disconnect_done); |
1da177e4 | 668 | |
66af1e55 TM |
669 | /** |
670 | * xprt_force_disconnect - force a transport to disconnect | |
671 | * @xprt: transport to disconnect | |
672 | * | |
673 | */ | |
674 | void xprt_force_disconnect(struct rpc_xprt *xprt) | |
675 | { | |
676 | /* Don't race with the test_bit() in xprt_clear_locked() */ | |
677 | spin_lock_bh(&xprt->transport_lock); | |
678 | set_bit(XPRT_CLOSE_WAIT, &xprt->state); | |
679 | /* Try to schedule an autoclose RPC call */ | |
680 | if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0) | |
40a5f1b1 | 681 | queue_work(xprtiod_workqueue, &xprt->task_cleanup); |
0445f92c TM |
682 | else if (xprt->snd_task) |
683 | rpc_wake_up_queued_task_set_status(&xprt->pending, | |
684 | xprt->snd_task, -ENOTCONN); | |
66af1e55 TM |
685 | spin_unlock_bh(&xprt->transport_lock); |
686 | } | |
e2a4f4fb | 687 | EXPORT_SYMBOL_GPL(xprt_force_disconnect); |
66af1e55 | 688 | |
7f3a1d1e TM |
689 | static unsigned int |
690 | xprt_connect_cookie(struct rpc_xprt *xprt) | |
691 | { | |
692 | return READ_ONCE(xprt->connect_cookie); | |
693 | } | |
694 | ||
695 | static bool | |
696 | xprt_request_retransmit_after_disconnect(struct rpc_task *task) | |
697 | { | |
698 | struct rpc_rqst *req = task->tk_rqstp; | |
699 | struct rpc_xprt *xprt = req->rq_xprt; | |
700 | ||
701 | return req->rq_connect_cookie != xprt_connect_cookie(xprt) || | |
702 | !xprt_connected(xprt); | |
703 | } | |
704 | ||
7c1d71cf TM |
705 | /** |
706 | * xprt_conditional_disconnect - force a transport to disconnect | |
707 | * @xprt: transport to disconnect | |
708 | * @cookie: 'connection cookie' | |
709 | * | |
710 | * This attempts to break the connection if and only if 'cookie' matches | |
711 | * the current transport 'connection cookie'. It ensures that we don't | |
712 | * try to break the connection more than once when we need to retransmit | |
713 | * a batch of RPC requests. | |
714 | * | |
715 | */ | |
716 | void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie) | |
717 | { | |
718 | /* Don't race with the test_bit() in xprt_clear_locked() */ | |
719 | spin_lock_bh(&xprt->transport_lock); | |
720 | if (cookie != xprt->connect_cookie) | |
721 | goto out; | |
2c2ee6d2 | 722 | if (test_bit(XPRT_CLOSING, &xprt->state)) |
7c1d71cf TM |
723 | goto out; |
724 | set_bit(XPRT_CLOSE_WAIT, &xprt->state); | |
725 | /* Try to schedule an autoclose RPC call */ | |
726 | if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0) | |
40a5f1b1 | 727 | queue_work(xprtiod_workqueue, &xprt->task_cleanup); |
2a491991 | 728 | xprt_wake_pending_tasks(xprt, -EAGAIN); |
7c1d71cf TM |
729 | out: |
730 | spin_unlock_bh(&xprt->transport_lock); | |
731 | } | |
732 | ||
ad3331ac TM |
733 | static bool |
734 | xprt_has_timer(const struct rpc_xprt *xprt) | |
735 | { | |
736 | return xprt->idle_timeout != 0; | |
737 | } | |
738 | ||
739 | static void | |
740 | xprt_schedule_autodisconnect(struct rpc_xprt *xprt) | |
741 | __must_hold(&xprt->transport_lock) | |
742 | { | |
95f7691d | 743 | if (RB_EMPTY_ROOT(&xprt->recv_queue) && xprt_has_timer(xprt)) |
ad3331ac TM |
744 | mod_timer(&xprt->timer, xprt->last_used + xprt->idle_timeout); |
745 | } | |
746 | ||
1da177e4 | 747 | static void |
ff861c4d | 748 | xprt_init_autodisconnect(struct timer_list *t) |
1da177e4 | 749 | { |
ff861c4d | 750 | struct rpc_xprt *xprt = from_timer(xprt, t, timer); |
1da177e4 | 751 | |
4a0f8c04 | 752 | spin_lock(&xprt->transport_lock); |
95f7691d | 753 | if (!RB_EMPTY_ROOT(&xprt->recv_queue)) |
1da177e4 | 754 | goto out_abort; |
ad3331ac TM |
755 | /* Reset xprt->last_used to avoid connect/autodisconnect cycling */ |
756 | xprt->last_used = jiffies; | |
2226feb6 | 757 | if (test_and_set_bit(XPRT_LOCKED, &xprt->state)) |
1da177e4 | 758 | goto out_abort; |
4a0f8c04 | 759 | spin_unlock(&xprt->transport_lock); |
40a5f1b1 | 760 | queue_work(xprtiod_workqueue, &xprt->task_cleanup); |
1da177e4 LT |
761 | return; |
762 | out_abort: | |
4a0f8c04 | 763 | spin_unlock(&xprt->transport_lock); |
1da177e4 LT |
764 | } |
765 | ||
718ba5b8 TM |
766 | bool xprt_lock_connect(struct rpc_xprt *xprt, |
767 | struct rpc_task *task, | |
768 | void *cookie) | |
769 | { | |
770 | bool ret = false; | |
771 | ||
772 | spin_lock_bh(&xprt->transport_lock); | |
773 | if (!test_bit(XPRT_LOCKED, &xprt->state)) | |
774 | goto out; | |
775 | if (xprt->snd_task != task) | |
776 | goto out; | |
777 | xprt->snd_task = cookie; | |
778 | ret = true; | |
779 | out: | |
780 | spin_unlock_bh(&xprt->transport_lock); | |
781 | return ret; | |
782 | } | |
783 | ||
784 | void xprt_unlock_connect(struct rpc_xprt *xprt, void *cookie) | |
785 | { | |
786 | spin_lock_bh(&xprt->transport_lock); | |
787 | if (xprt->snd_task != cookie) | |
788 | goto out; | |
789 | if (!test_bit(XPRT_LOCKED, &xprt->state)) | |
790 | goto out; | |
791 | xprt->snd_task =NULL; | |
792 | xprt->ops->release_xprt(xprt, NULL); | |
ad3331ac | 793 | xprt_schedule_autodisconnect(xprt); |
718ba5b8 TM |
794 | out: |
795 | spin_unlock_bh(&xprt->transport_lock); | |
79234c3d | 796 | wake_up_bit(&xprt->state, XPRT_LOCKED); |
718ba5b8 TM |
797 | } |
798 | ||
9903cd1c CL |
799 | /** |
800 | * xprt_connect - schedule a transport connect operation | |
801 | * @task: RPC task that is requesting the connect | |
1da177e4 LT |
802 | * |
803 | */ | |
804 | void xprt_connect(struct rpc_task *task) | |
805 | { | |
ad2368d6 | 806 | struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt; |
1da177e4 | 807 | |
46121cf7 | 808 | dprintk("RPC: %5u xprt_connect xprt %p %s connected\n", task->tk_pid, |
1da177e4 LT |
809 | xprt, (xprt_connected(xprt) ? "is" : "is not")); |
810 | ||
ec739ef0 | 811 | if (!xprt_bound(xprt)) { |
01d37c42 | 812 | task->tk_status = -EAGAIN; |
1da177e4 LT |
813 | return; |
814 | } | |
815 | if (!xprt_lock_write(xprt, task)) | |
816 | return; | |
feb8ca37 TM |
817 | |
818 | if (test_and_clear_bit(XPRT_CLOSE_WAIT, &xprt->state)) | |
819 | xprt->ops->close(xprt); | |
820 | ||
718ba5b8 | 821 | if (!xprt_connected(xprt)) { |
a8ce4a8f | 822 | task->tk_timeout = task->tk_rqstp->rq_timeout; |
2c2ee6d2 | 823 | task->tk_rqstp->rq_connect_cookie = xprt->connect_cookie; |
abc13275 | 824 | rpc_sleep_on(&xprt->pending, task, NULL); |
0b9e7943 TM |
825 | |
826 | if (test_bit(XPRT_CLOSING, &xprt->state)) | |
827 | return; | |
828 | if (xprt_test_and_set_connecting(xprt)) | |
829 | return; | |
0a9a4304 TM |
830 | /* Race breaker */ |
831 | if (!xprt_connected(xprt)) { | |
832 | xprt->stat.connect_start = jiffies; | |
833 | xprt->ops->connect(xprt, task); | |
834 | } else { | |
835 | xprt_clear_connecting(xprt); | |
836 | task->tk_status = 0; | |
837 | rpc_wake_up_queued_task(&xprt->pending, task); | |
838 | } | |
1da177e4 | 839 | } |
718ba5b8 | 840 | xprt_release_write(xprt, task); |
1da177e4 LT |
841 | } |
842 | ||
95f7691d TM |
843 | enum xprt_xid_rb_cmp { |
844 | XID_RB_EQUAL, | |
845 | XID_RB_LEFT, | |
846 | XID_RB_RIGHT, | |
847 | }; | |
848 | static enum xprt_xid_rb_cmp | |
849 | xprt_xid_cmp(__be32 xid1, __be32 xid2) | |
850 | { | |
851 | if (xid1 == xid2) | |
852 | return XID_RB_EQUAL; | |
853 | if ((__force u32)xid1 < (__force u32)xid2) | |
854 | return XID_RB_LEFT; | |
855 | return XID_RB_RIGHT; | |
856 | } | |
857 | ||
858 | static struct rpc_rqst * | |
859 | xprt_request_rb_find(struct rpc_xprt *xprt, __be32 xid) | |
860 | { | |
861 | struct rb_node *n = xprt->recv_queue.rb_node; | |
862 | struct rpc_rqst *req; | |
863 | ||
864 | while (n != NULL) { | |
865 | req = rb_entry(n, struct rpc_rqst, rq_recv); | |
866 | switch (xprt_xid_cmp(xid, req->rq_xid)) { | |
867 | case XID_RB_LEFT: | |
868 | n = n->rb_left; | |
869 | break; | |
870 | case XID_RB_RIGHT: | |
871 | n = n->rb_right; | |
872 | break; | |
873 | case XID_RB_EQUAL: | |
874 | return req; | |
875 | } | |
876 | } | |
877 | return NULL; | |
878 | } | |
879 | ||
880 | static void | |
881 | xprt_request_rb_insert(struct rpc_xprt *xprt, struct rpc_rqst *new) | |
882 | { | |
883 | struct rb_node **p = &xprt->recv_queue.rb_node; | |
884 | struct rb_node *n = NULL; | |
885 | struct rpc_rqst *req; | |
886 | ||
887 | while (*p != NULL) { | |
888 | n = *p; | |
889 | req = rb_entry(n, struct rpc_rqst, rq_recv); | |
890 | switch(xprt_xid_cmp(new->rq_xid, req->rq_xid)) { | |
891 | case XID_RB_LEFT: | |
892 | p = &n->rb_left; | |
893 | break; | |
894 | case XID_RB_RIGHT: | |
895 | p = &n->rb_right; | |
896 | break; | |
897 | case XID_RB_EQUAL: | |
898 | WARN_ON_ONCE(new != req); | |
899 | return; | |
900 | } | |
901 | } | |
902 | rb_link_node(&new->rq_recv, n, p); | |
903 | rb_insert_color(&new->rq_recv, &xprt->recv_queue); | |
904 | } | |
905 | ||
906 | static void | |
907 | xprt_request_rb_remove(struct rpc_xprt *xprt, struct rpc_rqst *req) | |
908 | { | |
909 | rb_erase(&req->rq_recv, &xprt->recv_queue); | |
910 | } | |
911 | ||
9903cd1c CL |
912 | /** |
913 | * xprt_lookup_rqst - find an RPC request corresponding to an XID | |
914 | * @xprt: transport on which the original request was transmitted | |
915 | * @xid: RPC XID of incoming reply | |
916 | * | |
75c84151 | 917 | * Caller holds xprt->queue_lock. |
1da177e4 | 918 | */ |
d8ed029d | 919 | struct rpc_rqst *xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid) |
1da177e4 | 920 | { |
8f3a6de3 | 921 | struct rpc_rqst *entry; |
1da177e4 | 922 | |
95f7691d TM |
923 | entry = xprt_request_rb_find(xprt, xid); |
924 | if (entry != NULL) { | |
925 | trace_xprt_lookup_rqst(xprt, xid, 0); | |
926 | entry->rq_rtt = ktime_sub(ktime_get(), entry->rq_xtime); | |
927 | return entry; | |
928 | } | |
46121cf7 CL |
929 | |
930 | dprintk("RPC: xprt_lookup_rqst did not find xid %08x\n", | |
931 | ntohl(xid)); | |
3705ad64 | 932 | trace_xprt_lookup_rqst(xprt, xid, -ENOENT); |
262ca07d CL |
933 | xprt->stat.bad_xids++; |
934 | return NULL; | |
1da177e4 | 935 | } |
12444809 | 936 | EXPORT_SYMBOL_GPL(xprt_lookup_rqst); |
1da177e4 | 937 | |
cf9946cd TM |
938 | static bool |
939 | xprt_is_pinned_rqst(struct rpc_rqst *req) | |
940 | { | |
941 | return atomic_read(&req->rq_pin) != 0; | |
942 | } | |
943 | ||
729749bb TM |
944 | /** |
945 | * xprt_pin_rqst - Pin a request on the transport receive list | |
946 | * @req: Request to pin | |
947 | * | |
948 | * Caller must ensure this is atomic with the call to xprt_lookup_rqst() | |
cf9946cd | 949 | * so should be holding the xprt receive lock. |
729749bb TM |
950 | */ |
951 | void xprt_pin_rqst(struct rpc_rqst *req) | |
952 | { | |
cf9946cd | 953 | atomic_inc(&req->rq_pin); |
729749bb | 954 | } |
9590d083 | 955 | EXPORT_SYMBOL_GPL(xprt_pin_rqst); |
729749bb TM |
956 | |
957 | /** | |
958 | * xprt_unpin_rqst - Unpin a request on the transport receive list | |
959 | * @req: Request to pin | |
960 | * | |
cf9946cd | 961 | * Caller should be holding the xprt receive lock. |
729749bb TM |
962 | */ |
963 | void xprt_unpin_rqst(struct rpc_rqst *req) | |
964 | { | |
cf9946cd TM |
965 | if (!test_bit(RPC_TASK_MSG_PIN_WAIT, &req->rq_task->tk_runstate)) { |
966 | atomic_dec(&req->rq_pin); | |
967 | return; | |
968 | } | |
969 | if (atomic_dec_and_test(&req->rq_pin)) | |
970 | wake_up_var(&req->rq_pin); | |
729749bb | 971 | } |
9590d083 | 972 | EXPORT_SYMBOL_GPL(xprt_unpin_rqst); |
729749bb TM |
973 | |
974 | static void xprt_wait_on_pinned_rqst(struct rpc_rqst *req) | |
729749bb | 975 | { |
cf9946cd | 976 | wait_var_event(&req->rq_pin, !xprt_is_pinned_rqst(req)); |
729749bb TM |
977 | } |
978 | ||
edc81dcd TM |
979 | static bool |
980 | xprt_request_data_received(struct rpc_task *task) | |
981 | { | |
982 | return !test_bit(RPC_TASK_NEED_RECV, &task->tk_runstate) && | |
983 | READ_ONCE(task->tk_rqstp->rq_reply_bytes_recvd) != 0; | |
984 | } | |
985 | ||
986 | static bool | |
987 | xprt_request_need_enqueue_receive(struct rpc_task *task, struct rpc_rqst *req) | |
988 | { | |
989 | return !test_bit(RPC_TASK_NEED_RECV, &task->tk_runstate) && | |
990 | READ_ONCE(task->tk_rqstp->rq_reply_bytes_recvd) == 0; | |
991 | } | |
992 | ||
993 | /** | |
994 | * xprt_request_enqueue_receive - Add an request to the receive queue | |
995 | * @task: RPC task | |
996 | * | |
997 | */ | |
998 | void | |
999 | xprt_request_enqueue_receive(struct rpc_task *task) | |
1000 | { | |
1001 | struct rpc_rqst *req = task->tk_rqstp; | |
1002 | struct rpc_xprt *xprt = req->rq_xprt; | |
1003 | ||
1004 | if (!xprt_request_need_enqueue_receive(task, req)) | |
1005 | return; | |
1006 | spin_lock(&xprt->queue_lock); | |
1007 | ||
1008 | /* Update the softirq receive buffer */ | |
1009 | memcpy(&req->rq_private_buf, &req->rq_rcv_buf, | |
1010 | sizeof(req->rq_private_buf)); | |
1011 | ||
1012 | /* Add request to the receive list */ | |
95f7691d | 1013 | xprt_request_rb_insert(xprt, req); |
edc81dcd TM |
1014 | set_bit(RPC_TASK_NEED_RECV, &task->tk_runstate); |
1015 | spin_unlock(&xprt->queue_lock); | |
1016 | ||
1017 | xprt_reset_majortimeo(req); | |
1018 | /* Turn off autodisconnect */ | |
1019 | del_singleshot_timer_sync(&xprt->timer); | |
1020 | } | |
1021 | ||
1022 | /** | |
1023 | * xprt_request_dequeue_receive_locked - Remove a request from the receive queue | |
1024 | * @task: RPC task | |
1025 | * | |
1026 | * Caller must hold xprt->queue_lock. | |
1027 | */ | |
1028 | static void | |
1029 | xprt_request_dequeue_receive_locked(struct rpc_task *task) | |
1030 | { | |
95f7691d TM |
1031 | struct rpc_rqst *req = task->tk_rqstp; |
1032 | ||
edc81dcd | 1033 | if (test_and_clear_bit(RPC_TASK_NEED_RECV, &task->tk_runstate)) |
95f7691d | 1034 | xprt_request_rb_remove(req->rq_xprt, req); |
edc81dcd TM |
1035 | } |
1036 | ||
ecd465ee CL |
1037 | /** |
1038 | * xprt_update_rtt - Update RPC RTT statistics | |
1039 | * @task: RPC request that recently completed | |
1040 | * | |
75c84151 | 1041 | * Caller holds xprt->queue_lock. |
ecd465ee CL |
1042 | */ |
1043 | void xprt_update_rtt(struct rpc_task *task) | |
1570c1e4 CL |
1044 | { |
1045 | struct rpc_rqst *req = task->tk_rqstp; | |
1046 | struct rpc_rtt *rtt = task->tk_client->cl_rtt; | |
95c96174 | 1047 | unsigned int timer = task->tk_msg.rpc_proc->p_timer; |
d60dbb20 | 1048 | long m = usecs_to_jiffies(ktime_to_us(req->rq_rtt)); |
1570c1e4 CL |
1049 | |
1050 | if (timer) { | |
1051 | if (req->rq_ntrans == 1) | |
ff839970 | 1052 | rpc_update_rtt(rtt, timer, m); |
1570c1e4 CL |
1053 | rpc_set_timeo(rtt, timer, req->rq_ntrans - 1); |
1054 | } | |
1055 | } | |
ecd465ee | 1056 | EXPORT_SYMBOL_GPL(xprt_update_rtt); |
1570c1e4 | 1057 | |
9903cd1c CL |
1058 | /** |
1059 | * xprt_complete_rqst - called when reply processing is complete | |
1570c1e4 | 1060 | * @task: RPC request that recently completed |
9903cd1c CL |
1061 | * @copied: actual number of bytes received from the transport |
1062 | * | |
75c84151 | 1063 | * Caller holds xprt->queue_lock. |
1da177e4 | 1064 | */ |
1570c1e4 | 1065 | void xprt_complete_rqst(struct rpc_task *task, int copied) |
1da177e4 | 1066 | { |
1570c1e4 | 1067 | struct rpc_rqst *req = task->tk_rqstp; |
fda13939 | 1068 | struct rpc_xprt *xprt = req->rq_xprt; |
1da177e4 | 1069 | |
1570c1e4 CL |
1070 | dprintk("RPC: %5u xid %08x complete (%d bytes received)\n", |
1071 | task->tk_pid, ntohl(req->rq_xid), copied); | |
3705ad64 | 1072 | trace_xprt_complete_rqst(xprt, req->rq_xid, copied); |
1da177e4 | 1073 | |
fda13939 | 1074 | xprt->stat.recvs++; |
ef759a2e | 1075 | |
1e799b67 | 1076 | req->rq_private_buf.len = copied; |
dd2b63d0 RL |
1077 | /* Ensure all writes are done before we update */ |
1078 | /* req->rq_reply_bytes_recvd */ | |
43ac3f29 | 1079 | smp_wmb(); |
dd2b63d0 | 1080 | req->rq_reply_bytes_recvd = copied; |
edc81dcd | 1081 | xprt_request_dequeue_receive_locked(task); |
fda13939 | 1082 | rpc_wake_up_queued_task(&xprt->pending, task); |
1da177e4 | 1083 | } |
12444809 | 1084 | EXPORT_SYMBOL_GPL(xprt_complete_rqst); |
1da177e4 | 1085 | |
46c0ee8b | 1086 | static void xprt_timer(struct rpc_task *task) |
1da177e4 | 1087 | { |
46c0ee8b | 1088 | struct rpc_rqst *req = task->tk_rqstp; |
1da177e4 LT |
1089 | struct rpc_xprt *xprt = req->rq_xprt; |
1090 | ||
5d00837b TM |
1091 | if (task->tk_status != -ETIMEDOUT) |
1092 | return; | |
1da177e4 | 1093 | |
82476d9f | 1094 | trace_xprt_timer(xprt, req->rq_xid, task->tk_status); |
dd2b63d0 | 1095 | if (!req->rq_reply_bytes_recvd) { |
46c0ee8b | 1096 | if (xprt->ops->timer) |
6a24dfb6 | 1097 | xprt->ops->timer(xprt, task); |
5d00837b TM |
1098 | } else |
1099 | task->tk_status = 0; | |
1da177e4 LT |
1100 | } |
1101 | ||
7f3a1d1e TM |
1102 | /** |
1103 | * xprt_request_wait_receive - wait for the reply to an RPC request | |
1104 | * @task: RPC task about to send a request | |
1105 | * | |
1106 | */ | |
1107 | void xprt_request_wait_receive(struct rpc_task *task) | |
1108 | { | |
1109 | struct rpc_rqst *req = task->tk_rqstp; | |
1110 | struct rpc_xprt *xprt = req->rq_xprt; | |
1111 | ||
1112 | if (!test_bit(RPC_TASK_NEED_RECV, &task->tk_runstate)) | |
1113 | return; | |
1114 | /* | |
1115 | * Sleep on the pending queue if we're expecting a reply. | |
1116 | * The spinlock ensures atomicity between the test of | |
1117 | * req->rq_reply_bytes_recvd, and the call to rpc_sleep_on(). | |
1118 | */ | |
1119 | spin_lock(&xprt->queue_lock); | |
1120 | if (test_bit(RPC_TASK_NEED_RECV, &task->tk_runstate)) { | |
1121 | xprt->ops->set_retrans_timeout(task); | |
1122 | rpc_sleep_on(&xprt->pending, task, xprt_timer); | |
1123 | /* | |
1124 | * Send an extra queue wakeup call if the | |
1125 | * connection was dropped in case the call to | |
1126 | * rpc_sleep_on() raced. | |
1127 | */ | |
1128 | if (xprt_request_retransmit_after_disconnect(task)) | |
1129 | rpc_wake_up_queued_task_set_status(&xprt->pending, | |
1130 | task, -ENOTCONN); | |
1131 | } | |
1132 | spin_unlock(&xprt->queue_lock); | |
1133 | } | |
1134 | ||
944b0429 TM |
1135 | static bool |
1136 | xprt_request_need_enqueue_transmit(struct rpc_task *task, struct rpc_rqst *req) | |
1137 | { | |
762e4e67 | 1138 | return !test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate); |
944b0429 TM |
1139 | } |
1140 | ||
1141 | /** | |
1142 | * xprt_request_enqueue_transmit - queue a task for transmission | |
1143 | * @task: pointer to rpc_task | |
1144 | * | |
1145 | * Add a task to the transmission queue. | |
1146 | */ | |
1147 | void | |
1148 | xprt_request_enqueue_transmit(struct rpc_task *task) | |
1149 | { | |
918f3c1f | 1150 | struct rpc_rqst *pos, *req = task->tk_rqstp; |
944b0429 TM |
1151 | struct rpc_xprt *xprt = req->rq_xprt; |
1152 | ||
1153 | if (xprt_request_need_enqueue_transmit(task, req)) { | |
1154 | spin_lock(&xprt->queue_lock); | |
75891f50 TM |
1155 | /* |
1156 | * Requests that carry congestion control credits are added | |
1157 | * to the head of the list to avoid starvation issues. | |
1158 | */ | |
1159 | if (req->rq_cong) { | |
1160 | xprt_clear_congestion_window_wait(xprt); | |
1161 | list_for_each_entry(pos, &xprt->xmit_queue, rq_xmit) { | |
1162 | if (pos->rq_cong) | |
1163 | continue; | |
1164 | /* Note: req is added _before_ pos */ | |
1165 | list_add_tail(&req->rq_xmit, &pos->rq_xmit); | |
1166 | INIT_LIST_HEAD(&req->rq_xmit2); | |
1167 | goto out; | |
1168 | } | |
86aeee0e TM |
1169 | } else if (RPC_IS_SWAPPER(task)) { |
1170 | list_for_each_entry(pos, &xprt->xmit_queue, rq_xmit) { | |
1171 | if (pos->rq_cong || pos->rq_bytes_sent) | |
1172 | continue; | |
1173 | if (RPC_IS_SWAPPER(pos->rq_task)) | |
1174 | continue; | |
1175 | /* Note: req is added _before_ pos */ | |
1176 | list_add_tail(&req->rq_xmit, &pos->rq_xmit); | |
1177 | INIT_LIST_HEAD(&req->rq_xmit2); | |
1178 | goto out; | |
1179 | } | |
75891f50 TM |
1180 | } else { |
1181 | list_for_each_entry(pos, &xprt->xmit_queue, rq_xmit) { | |
1182 | if (pos->rq_task->tk_owner != task->tk_owner) | |
1183 | continue; | |
1184 | list_add_tail(&req->rq_xmit2, &pos->rq_xmit2); | |
1185 | INIT_LIST_HEAD(&req->rq_xmit); | |
1186 | goto out; | |
1187 | } | |
918f3c1f | 1188 | } |
944b0429 | 1189 | list_add_tail(&req->rq_xmit, &xprt->xmit_queue); |
918f3c1f TM |
1190 | INIT_LIST_HEAD(&req->rq_xmit2); |
1191 | out: | |
944b0429 TM |
1192 | set_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate); |
1193 | spin_unlock(&xprt->queue_lock); | |
1194 | } | |
1195 | } | |
1196 | ||
1197 | /** | |
1198 | * xprt_request_dequeue_transmit_locked - remove a task from the transmission queue | |
1199 | * @task: pointer to rpc_task | |
1200 | * | |
1201 | * Remove a task from the transmission queue | |
1202 | * Caller must hold xprt->queue_lock | |
1203 | */ | |
1204 | static void | |
1205 | xprt_request_dequeue_transmit_locked(struct rpc_task *task) | |
1206 | { | |
918f3c1f TM |
1207 | struct rpc_rqst *req = task->tk_rqstp; |
1208 | ||
1209 | if (!test_and_clear_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) | |
1210 | return; | |
1211 | if (!list_empty(&req->rq_xmit)) { | |
1212 | list_del(&req->rq_xmit); | |
1213 | if (!list_empty(&req->rq_xmit2)) { | |
1214 | struct rpc_rqst *next = list_first_entry(&req->rq_xmit2, | |
1215 | struct rpc_rqst, rq_xmit2); | |
1216 | list_del(&req->rq_xmit2); | |
1217 | list_add_tail(&next->rq_xmit, &next->rq_xprt->xmit_queue); | |
1218 | } | |
1219 | } else | |
1220 | list_del(&req->rq_xmit2); | |
944b0429 TM |
1221 | } |
1222 | ||
1223 | /** | |
1224 | * xprt_request_dequeue_transmit - remove a task from the transmission queue | |
1225 | * @task: pointer to rpc_task | |
1226 | * | |
1227 | * Remove a task from the transmission queue | |
1228 | */ | |
1229 | static void | |
1230 | xprt_request_dequeue_transmit(struct rpc_task *task) | |
1231 | { | |
1232 | struct rpc_rqst *req = task->tk_rqstp; | |
1233 | struct rpc_xprt *xprt = req->rq_xprt; | |
1234 | ||
1235 | spin_lock(&xprt->queue_lock); | |
1236 | xprt_request_dequeue_transmit_locked(task); | |
1237 | spin_unlock(&xprt->queue_lock); | |
1238 | } | |
1239 | ||
9d96acbc TM |
1240 | /** |
1241 | * xprt_request_prepare - prepare an encoded request for transport | |
1242 | * @req: pointer to rpc_rqst | |
1243 | * | |
1244 | * Calls into the transport layer to do whatever is needed to prepare | |
1245 | * the request for transmission or receive. | |
1246 | */ | |
1247 | void | |
1248 | xprt_request_prepare(struct rpc_rqst *req) | |
1249 | { | |
1250 | struct rpc_xprt *xprt = req->rq_xprt; | |
1251 | ||
1252 | if (xprt->ops->prepare_request) | |
1253 | xprt->ops->prepare_request(req); | |
1254 | } | |
1255 | ||
762e4e67 TM |
1256 | /** |
1257 | * xprt_request_need_retransmit - Test if a task needs retransmission | |
1258 | * @task: pointer to rpc_task | |
1259 | * | |
1260 | * Test for whether a connection breakage requires the task to retransmit | |
1261 | */ | |
1262 | bool | |
1263 | xprt_request_need_retransmit(struct rpc_task *task) | |
1264 | { | |
1265 | return xprt_request_retransmit_after_disconnect(task); | |
1266 | } | |
1267 | ||
9903cd1c CL |
1268 | /** |
1269 | * xprt_prepare_transmit - reserve the transport before sending a request | |
1270 | * @task: RPC task about to send a request | |
1271 | * | |
1da177e4 | 1272 | */ |
90051ea7 | 1273 | bool xprt_prepare_transmit(struct rpc_task *task) |
1da177e4 LT |
1274 | { |
1275 | struct rpc_rqst *req = task->tk_rqstp; | |
1276 | struct rpc_xprt *xprt = req->rq_xprt; | |
1da177e4 | 1277 | |
46121cf7 | 1278 | dprintk("RPC: %5u xprt_prepare_transmit\n", task->tk_pid); |
1da177e4 | 1279 | |
5f2f6bd9 TM |
1280 | if (!xprt_lock_write(xprt, task)) { |
1281 | /* Race breaker: someone may have transmitted us */ | |
944b0429 | 1282 | if (!test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) |
5f2f6bd9 TM |
1283 | rpc_wake_up_queued_task_set_status(&xprt->sending, |
1284 | task, 0); | |
1285 | return false; | |
1286 | ||
90051ea7 | 1287 | } |
5f2f6bd9 | 1288 | return true; |
1da177e4 LT |
1289 | } |
1290 | ||
e0ab53de | 1291 | void xprt_end_transmit(struct rpc_task *task) |
5e5ce5be | 1292 | { |
343952fa | 1293 | xprt_release_write(task->tk_rqstp->rq_xprt, task); |
5e5ce5be TM |
1294 | } |
1295 | ||
9903cd1c | 1296 | /** |
89f90fe1 TM |
1297 | * xprt_request_transmit - send an RPC request on a transport |
1298 | * @req: pointer to request to transmit | |
1299 | * @snd_task: RPC task that owns the transport lock | |
9903cd1c | 1300 | * |
89f90fe1 TM |
1301 | * This performs the transmission of a single request. |
1302 | * Note that if the request is not the same as snd_task, then it | |
1303 | * does need to be pinned. | |
1304 | * Returns '0' on success. | |
9903cd1c | 1305 | */ |
89f90fe1 TM |
1306 | static int |
1307 | xprt_request_transmit(struct rpc_rqst *req, struct rpc_task *snd_task) | |
1da177e4 | 1308 | { |
89f90fe1 TM |
1309 | struct rpc_xprt *xprt = req->rq_xprt; |
1310 | struct rpc_task *task = req->rq_task; | |
90d91b0c | 1311 | unsigned int connect_cookie; |
dcbbeda8 | 1312 | int is_retrans = RPC_WAS_SENT(task); |
ff699ea8 | 1313 | int status; |
1da177e4 | 1314 | |
46121cf7 | 1315 | dprintk("RPC: %5u xprt_transmit(%u)\n", task->tk_pid, req->rq_slen); |
1da177e4 | 1316 | |
edc81dcd | 1317 | if (!req->rq_bytes_sent) { |
89f90fe1 TM |
1318 | if (xprt_request_data_received(task)) { |
1319 | status = 0; | |
944b0429 | 1320 | goto out_dequeue; |
89f90fe1 | 1321 | } |
3021a5bb | 1322 | /* Verify that our message lies in the RPCSEC_GSS window */ |
edc81dcd | 1323 | if (rpcauth_xmit_need_reencode(task)) { |
89f90fe1 | 1324 | status = -EBADMSG; |
944b0429 | 1325 | goto out_dequeue; |
3021a5bb | 1326 | } |
edc81dcd | 1327 | } |
1da177e4 | 1328 | |
dcbbeda8 TM |
1329 | /* |
1330 | * Update req->rq_ntrans before transmitting to avoid races with | |
1331 | * xprt_update_rtt(), which needs to know that it is recording a | |
1332 | * reply to the first transmission. | |
1333 | */ | |
1334 | req->rq_ntrans++; | |
1335 | ||
90d91b0c | 1336 | connect_cookie = xprt->connect_cookie; |
adfa7144 | 1337 | status = xprt->ops->send_request(req); |
3705ad64 | 1338 | trace_xprt_transmit(xprt, req->rq_xid, status); |
c8485e4d | 1339 | if (status != 0) { |
dcbbeda8 | 1340 | req->rq_ntrans--; |
89f90fe1 | 1341 | return status; |
c8485e4d | 1342 | } |
7ebbbc6e | 1343 | |
dcbbeda8 TM |
1344 | if (is_retrans) |
1345 | task->tk_client->cl_stats->rpcretrans++; | |
1346 | ||
4a068258 | 1347 | xprt_inject_disconnect(xprt); |
262ca07d | 1348 | |
c8485e4d | 1349 | dprintk("RPC: %5u xmit complete\n", task->tk_pid); |
468f8613 | 1350 | task->tk_flags |= RPC_TASK_SENT; |
c8485e4d | 1351 | spin_lock_bh(&xprt->transport_lock); |
262ca07d | 1352 | |
c8485e4d TM |
1353 | xprt->stat.sends++; |
1354 | xprt->stat.req_u += xprt->stat.sends - xprt->stat.recvs; | |
1355 | xprt->stat.bklog_u += xprt->backlog.qlen; | |
15a45206 AA |
1356 | xprt->stat.sending_u += xprt->sending.qlen; |
1357 | xprt->stat.pending_u += xprt->pending.qlen; | |
90d91b0c | 1358 | spin_unlock_bh(&xprt->transport_lock); |
1da177e4 | 1359 | |
90d91b0c | 1360 | req->rq_connect_cookie = connect_cookie; |
944b0429 TM |
1361 | out_dequeue: |
1362 | xprt_request_dequeue_transmit(task); | |
89f90fe1 TM |
1363 | rpc_wake_up_queued_task_set_status(&xprt->sending, task, status); |
1364 | return status; | |
1365 | } | |
1366 | ||
1367 | /** | |
1368 | * xprt_transmit - send an RPC request on a transport | |
1369 | * @task: controlling RPC task | |
1370 | * | |
1371 | * Attempts to drain the transmit queue. On exit, either the transport | |
1372 | * signalled an error that needs to be handled before transmission can | |
1373 | * resume, or @task finished transmitting, and detected that it already | |
1374 | * received a reply. | |
1375 | */ | |
1376 | void | |
1377 | xprt_transmit(struct rpc_task *task) | |
1378 | { | |
1379 | struct rpc_rqst *next, *req = task->tk_rqstp; | |
1380 | struct rpc_xprt *xprt = req->rq_xprt; | |
1381 | int status; | |
1382 | ||
1383 | spin_lock(&xprt->queue_lock); | |
1384 | while (!list_empty(&xprt->xmit_queue)) { | |
1385 | next = list_first_entry(&xprt->xmit_queue, | |
1386 | struct rpc_rqst, rq_xmit); | |
1387 | xprt_pin_rqst(next); | |
1388 | spin_unlock(&xprt->queue_lock); | |
1389 | status = xprt_request_transmit(next, task); | |
1390 | if (status == -EBADMSG && next != req) | |
1391 | status = 0; | |
1392 | cond_resched(); | |
1393 | spin_lock(&xprt->queue_lock); | |
1394 | xprt_unpin_rqst(next); | |
1395 | if (status == 0) { | |
1396 | if (!xprt_request_data_received(task) || | |
1397 | test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) | |
1398 | continue; | |
c544577d | 1399 | } else if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) |
89f90fe1 TM |
1400 | task->tk_status = status; |
1401 | break; | |
1402 | } | |
1403 | spin_unlock(&xprt->queue_lock); | |
1da177e4 LT |
1404 | } |
1405 | ||
ba60eb25 TM |
1406 | static void xprt_add_backlog(struct rpc_xprt *xprt, struct rpc_task *task) |
1407 | { | |
1408 | set_bit(XPRT_CONGESTED, &xprt->state); | |
1409 | rpc_sleep_on(&xprt->backlog, task, NULL); | |
1410 | } | |
1411 | ||
1412 | static void xprt_wake_up_backlog(struct rpc_xprt *xprt) | |
1413 | { | |
1414 | if (rpc_wake_up_next(&xprt->backlog) == NULL) | |
1415 | clear_bit(XPRT_CONGESTED, &xprt->state); | |
1416 | } | |
1417 | ||
1418 | static bool xprt_throttle_congested(struct rpc_xprt *xprt, struct rpc_task *task) | |
1419 | { | |
1420 | bool ret = false; | |
1421 | ||
1422 | if (!test_bit(XPRT_CONGESTED, &xprt->state)) | |
1423 | goto out; | |
1424 | spin_lock(&xprt->reserve_lock); | |
1425 | if (test_bit(XPRT_CONGESTED, &xprt->state)) { | |
1426 | rpc_sleep_on(&xprt->backlog, task, NULL); | |
1427 | ret = true; | |
1428 | } | |
1429 | spin_unlock(&xprt->reserve_lock); | |
1430 | out: | |
1431 | return ret; | |
1432 | } | |
1433 | ||
92ea011f | 1434 | static struct rpc_rqst *xprt_dynamic_alloc_slot(struct rpc_xprt *xprt) |
d9ba131d TM |
1435 | { |
1436 | struct rpc_rqst *req = ERR_PTR(-EAGAIN); | |
1437 | ||
ff699ea8 | 1438 | if (xprt->num_reqs >= xprt->max_reqs) |
d9ba131d | 1439 | goto out; |
ff699ea8 | 1440 | ++xprt->num_reqs; |
92ea011f TM |
1441 | spin_unlock(&xprt->reserve_lock); |
1442 | req = kzalloc(sizeof(struct rpc_rqst), GFP_NOFS); | |
1443 | spin_lock(&xprt->reserve_lock); | |
d9ba131d TM |
1444 | if (req != NULL) |
1445 | goto out; | |
ff699ea8 | 1446 | --xprt->num_reqs; |
d9ba131d TM |
1447 | req = ERR_PTR(-ENOMEM); |
1448 | out: | |
1449 | return req; | |
1450 | } | |
1451 | ||
1452 | static bool xprt_dynamic_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *req) | |
1453 | { | |
ff699ea8 CL |
1454 | if (xprt->num_reqs > xprt->min_reqs) { |
1455 | --xprt->num_reqs; | |
d9ba131d TM |
1456 | kfree(req); |
1457 | return true; | |
1458 | } | |
1459 | return false; | |
1460 | } | |
1461 | ||
f39c1bfb | 1462 | void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task) |
1da177e4 | 1463 | { |
d9ba131d | 1464 | struct rpc_rqst *req; |
1da177e4 | 1465 | |
f39c1bfb | 1466 | spin_lock(&xprt->reserve_lock); |
1da177e4 | 1467 | if (!list_empty(&xprt->free)) { |
d9ba131d TM |
1468 | req = list_entry(xprt->free.next, struct rpc_rqst, rq_list); |
1469 | list_del(&req->rq_list); | |
1470 | goto out_init_req; | |
1471 | } | |
92ea011f | 1472 | req = xprt_dynamic_alloc_slot(xprt); |
d9ba131d TM |
1473 | if (!IS_ERR(req)) |
1474 | goto out_init_req; | |
1475 | switch (PTR_ERR(req)) { | |
1476 | case -ENOMEM: | |
d9ba131d TM |
1477 | dprintk("RPC: dynamic allocation of request slot " |
1478 | "failed! Retrying\n"); | |
1afeaf5c | 1479 | task->tk_status = -ENOMEM; |
d9ba131d TM |
1480 | break; |
1481 | case -EAGAIN: | |
ba60eb25 | 1482 | xprt_add_backlog(xprt, task); |
d9ba131d | 1483 | dprintk("RPC: waiting for request slot\n"); |
e9d47639 | 1484 | /* fall through */ |
1afeaf5c TM |
1485 | default: |
1486 | task->tk_status = -EAGAIN; | |
1da177e4 | 1487 | } |
f39c1bfb | 1488 | spin_unlock(&xprt->reserve_lock); |
d9ba131d TM |
1489 | return; |
1490 | out_init_req: | |
ff699ea8 CL |
1491 | xprt->stat.max_slots = max_t(unsigned int, xprt->stat.max_slots, |
1492 | xprt->num_reqs); | |
37ac86c3 CL |
1493 | spin_unlock(&xprt->reserve_lock); |
1494 | ||
d9ba131d TM |
1495 | task->tk_status = 0; |
1496 | task->tk_rqstp = req; | |
f39c1bfb TM |
1497 | } |
1498 | EXPORT_SYMBOL_GPL(xprt_alloc_slot); | |
1499 | ||
a9cde23a | 1500 | void xprt_free_slot(struct rpc_xprt *xprt, struct rpc_rqst *req) |
ee5ebe85 | 1501 | { |
ee5ebe85 | 1502 | spin_lock(&xprt->reserve_lock); |
c25573b5 TM |
1503 | if (!xprt_dynamic_free_slot(xprt, req)) { |
1504 | memset(req, 0, sizeof(*req)); /* mark unused */ | |
1505 | list_add(&req->rq_list, &xprt->free); | |
1506 | } | |
ba60eb25 | 1507 | xprt_wake_up_backlog(xprt); |
ee5ebe85 TM |
1508 | spin_unlock(&xprt->reserve_lock); |
1509 | } | |
a9cde23a | 1510 | EXPORT_SYMBOL_GPL(xprt_free_slot); |
ee5ebe85 | 1511 | |
21de0a95 TM |
1512 | static void xprt_free_all_slots(struct rpc_xprt *xprt) |
1513 | { | |
1514 | struct rpc_rqst *req; | |
1515 | while (!list_empty(&xprt->free)) { | |
1516 | req = list_first_entry(&xprt->free, struct rpc_rqst, rq_list); | |
1517 | list_del(&req->rq_list); | |
1518 | kfree(req); | |
1519 | } | |
1520 | } | |
1521 | ||
d9ba131d TM |
1522 | struct rpc_xprt *xprt_alloc(struct net *net, size_t size, |
1523 | unsigned int num_prealloc, | |
1524 | unsigned int max_alloc) | |
bd1722d4 PE |
1525 | { |
1526 | struct rpc_xprt *xprt; | |
21de0a95 TM |
1527 | struct rpc_rqst *req; |
1528 | int i; | |
bd1722d4 PE |
1529 | |
1530 | xprt = kzalloc(size, GFP_KERNEL); | |
1531 | if (xprt == NULL) | |
1532 | goto out; | |
1533 | ||
21de0a95 TM |
1534 | xprt_init(xprt, net); |
1535 | ||
1536 | for (i = 0; i < num_prealloc; i++) { | |
1537 | req = kzalloc(sizeof(struct rpc_rqst), GFP_KERNEL); | |
1538 | if (!req) | |
8313164c | 1539 | goto out_free; |
21de0a95 TM |
1540 | list_add(&req->rq_list, &xprt->free); |
1541 | } | |
d9ba131d TM |
1542 | if (max_alloc > num_prealloc) |
1543 | xprt->max_reqs = max_alloc; | |
1544 | else | |
1545 | xprt->max_reqs = num_prealloc; | |
1546 | xprt->min_reqs = num_prealloc; | |
ff699ea8 | 1547 | xprt->num_reqs = num_prealloc; |
bd1722d4 PE |
1548 | |
1549 | return xprt; | |
1550 | ||
1551 | out_free: | |
21de0a95 | 1552 | xprt_free(xprt); |
bd1722d4 PE |
1553 | out: |
1554 | return NULL; | |
1555 | } | |
1556 | EXPORT_SYMBOL_GPL(xprt_alloc); | |
1557 | ||
e204e621 PE |
1558 | void xprt_free(struct rpc_xprt *xprt) |
1559 | { | |
37aa2133 | 1560 | put_net(xprt->xprt_net); |
21de0a95 | 1561 | xprt_free_all_slots(xprt); |
fda1bfef | 1562 | kfree_rcu(xprt, rcu); |
e204e621 PE |
1563 | } |
1564 | EXPORT_SYMBOL_GPL(xprt_free); | |
1565 | ||
902c5887 TM |
1566 | static void |
1567 | xprt_init_connect_cookie(struct rpc_rqst *req, struct rpc_xprt *xprt) | |
1568 | { | |
1569 | req->rq_connect_cookie = xprt_connect_cookie(xprt) - 1; | |
1570 | } | |
1571 | ||
9dc6edcf TM |
1572 | static __be32 |
1573 | xprt_alloc_xid(struct rpc_xprt *xprt) | |
1574 | { | |
1575 | __be32 xid; | |
1576 | ||
1577 | spin_lock(&xprt->reserve_lock); | |
1578 | xid = (__force __be32)xprt->xid++; | |
1579 | spin_unlock(&xprt->reserve_lock); | |
1580 | return xid; | |
1581 | } | |
1582 | ||
1583 | static void | |
1584 | xprt_init_xid(struct rpc_xprt *xprt) | |
1585 | { | |
1586 | xprt->xid = prandom_u32(); | |
1587 | } | |
1588 | ||
1589 | static void | |
1590 | xprt_request_init(struct rpc_task *task) | |
1591 | { | |
1592 | struct rpc_xprt *xprt = task->tk_xprt; | |
1593 | struct rpc_rqst *req = task->tk_rqstp; | |
1594 | ||
9dc6edcf TM |
1595 | req->rq_timeout = task->tk_client->cl_timeout->to_initval; |
1596 | req->rq_task = task; | |
1597 | req->rq_xprt = xprt; | |
1598 | req->rq_buffer = NULL; | |
1599 | req->rq_xid = xprt_alloc_xid(xprt); | |
902c5887 | 1600 | xprt_init_connect_cookie(req, xprt); |
9dc6edcf TM |
1601 | req->rq_bytes_sent = 0; |
1602 | req->rq_snd_buf.len = 0; | |
1603 | req->rq_snd_buf.buflen = 0; | |
1604 | req->rq_rcv_buf.len = 0; | |
1605 | req->rq_rcv_buf.buflen = 0; | |
71700bb9 TM |
1606 | req->rq_snd_buf.bvec = NULL; |
1607 | req->rq_rcv_buf.bvec = NULL; | |
9dc6edcf TM |
1608 | req->rq_release_snd_buf = NULL; |
1609 | xprt_reset_majortimeo(req); | |
1610 | dprintk("RPC: %5u reserved req %p xid %08x\n", task->tk_pid, | |
1611 | req, ntohl(req->rq_xid)); | |
1612 | } | |
1613 | ||
1614 | static void | |
1615 | xprt_do_reserve(struct rpc_xprt *xprt, struct rpc_task *task) | |
1616 | { | |
1617 | xprt->ops->alloc_slot(xprt, task); | |
1618 | if (task->tk_rqstp != NULL) | |
1619 | xprt_request_init(task); | |
1620 | } | |
1621 | ||
9903cd1c CL |
1622 | /** |
1623 | * xprt_reserve - allocate an RPC request slot | |
1624 | * @task: RPC task requesting a slot allocation | |
1625 | * | |
ba60eb25 TM |
1626 | * If the transport is marked as being congested, or if no more |
1627 | * slots are available, place the task on the transport's | |
9903cd1c CL |
1628 | * backlog queue. |
1629 | */ | |
1630 | void xprt_reserve(struct rpc_task *task) | |
1da177e4 | 1631 | { |
fb43d172 | 1632 | struct rpc_xprt *xprt = task->tk_xprt; |
1da177e4 | 1633 | |
43cedbf0 TM |
1634 | task->tk_status = 0; |
1635 | if (task->tk_rqstp != NULL) | |
1636 | return; | |
1637 | ||
43cedbf0 TM |
1638 | task->tk_timeout = 0; |
1639 | task->tk_status = -EAGAIN; | |
ba60eb25 | 1640 | if (!xprt_throttle_congested(xprt, task)) |
9dc6edcf | 1641 | xprt_do_reserve(xprt, task); |
ba60eb25 TM |
1642 | } |
1643 | ||
1644 | /** | |
1645 | * xprt_retry_reserve - allocate an RPC request slot | |
1646 | * @task: RPC task requesting a slot allocation | |
1647 | * | |
1648 | * If no more slots are available, place the task on the transport's | |
1649 | * backlog queue. | |
1650 | * Note that the only difference with xprt_reserve is that we now | |
1651 | * ignore the value of the XPRT_CONGESTED flag. | |
1652 | */ | |
1653 | void xprt_retry_reserve(struct rpc_task *task) | |
1654 | { | |
fb43d172 | 1655 | struct rpc_xprt *xprt = task->tk_xprt; |
ba60eb25 TM |
1656 | |
1657 | task->tk_status = 0; | |
1658 | if (task->tk_rqstp != NULL) | |
1659 | return; | |
1660 | ||
1661 | task->tk_timeout = 0; | |
1662 | task->tk_status = -EAGAIN; | |
9dc6edcf | 1663 | xprt_do_reserve(xprt, task); |
1da177e4 LT |
1664 | } |
1665 | ||
edc81dcd TM |
1666 | static void |
1667 | xprt_request_dequeue_all(struct rpc_task *task, struct rpc_rqst *req) | |
1668 | { | |
1669 | struct rpc_xprt *xprt = req->rq_xprt; | |
1670 | ||
944b0429 TM |
1671 | if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate) || |
1672 | test_bit(RPC_TASK_NEED_RECV, &task->tk_runstate) || | |
edc81dcd TM |
1673 | xprt_is_pinned_rqst(req)) { |
1674 | spin_lock(&xprt->queue_lock); | |
944b0429 | 1675 | xprt_request_dequeue_transmit_locked(task); |
edc81dcd TM |
1676 | xprt_request_dequeue_receive_locked(task); |
1677 | while (xprt_is_pinned_rqst(req)) { | |
1678 | set_bit(RPC_TASK_MSG_PIN_WAIT, &task->tk_runstate); | |
1679 | spin_unlock(&xprt->queue_lock); | |
1680 | xprt_wait_on_pinned_rqst(req); | |
1681 | spin_lock(&xprt->queue_lock); | |
1682 | clear_bit(RPC_TASK_MSG_PIN_WAIT, &task->tk_runstate); | |
1683 | } | |
1684 | spin_unlock(&xprt->queue_lock); | |
1685 | } | |
1686 | } | |
1687 | ||
9903cd1c CL |
1688 | /** |
1689 | * xprt_release - release an RPC request slot | |
1690 | * @task: task which is finished with the slot | |
1691 | * | |
1da177e4 | 1692 | */ |
9903cd1c | 1693 | void xprt_release(struct rpc_task *task) |
1da177e4 | 1694 | { |
55ae1aab | 1695 | struct rpc_xprt *xprt; |
87ed5003 | 1696 | struct rpc_rqst *req = task->tk_rqstp; |
1da177e4 | 1697 | |
87ed5003 TM |
1698 | if (req == NULL) { |
1699 | if (task->tk_client) { | |
fb43d172 | 1700 | xprt = task->tk_xprt; |
bd79bc57 | 1701 | xprt_release_write(xprt, task); |
87ed5003 | 1702 | } |
1da177e4 | 1703 | return; |
87ed5003 | 1704 | } |
55ae1aab | 1705 | |
55ae1aab | 1706 | xprt = req->rq_xprt; |
0a702195 WAA |
1707 | if (task->tk_ops->rpc_count_stats != NULL) |
1708 | task->tk_ops->rpc_count_stats(task, task->tk_calldata); | |
1709 | else if (task->tk_client) | |
1710 | rpc_count_iostats(task, task->tk_client->cl_metrics); | |
edc81dcd | 1711 | xprt_request_dequeue_all(task, req); |
4a0f8c04 | 1712 | spin_lock_bh(&xprt->transport_lock); |
49e9a890 | 1713 | xprt->ops->release_xprt(xprt, task); |
a58dd398 CL |
1714 | if (xprt->ops->release_request) |
1715 | xprt->ops->release_request(task); | |
1da177e4 | 1716 | xprt->last_used = jiffies; |
ad3331ac | 1717 | xprt_schedule_autodisconnect(xprt); |
4a0f8c04 | 1718 | spin_unlock_bh(&xprt->transport_lock); |
ee5ebe85 | 1719 | if (req->rq_buffer) |
3435c74a | 1720 | xprt->ops->buf_free(task); |
4a068258 | 1721 | xprt_inject_disconnect(xprt); |
9d96acbc | 1722 | xdr_free_bvec(&req->rq_rcv_buf); |
a17c2153 TM |
1723 | if (req->rq_cred != NULL) |
1724 | put_rpccred(req->rq_cred); | |
1da177e4 | 1725 | task->tk_rqstp = NULL; |
ead5e1c2 BF |
1726 | if (req->rq_release_snd_buf) |
1727 | req->rq_release_snd_buf(req); | |
55ae1aab | 1728 | |
46121cf7 | 1729 | dprintk("RPC: %5u release request %p\n", task->tk_pid, req); |
ee5ebe85 | 1730 | if (likely(!bc_prealloc(req))) |
a9cde23a | 1731 | xprt->ops->free_slot(xprt, req); |
ee5ebe85 | 1732 | else |
c9acb42e | 1733 | xprt_free_bc_request(req); |
1da177e4 LT |
1734 | } |
1735 | ||
902c5887 TM |
1736 | #ifdef CONFIG_SUNRPC_BACKCHANNEL |
1737 | void | |
1738 | xprt_init_bc_request(struct rpc_rqst *req, struct rpc_task *task) | |
1739 | { | |
1740 | struct xdr_buf *xbufp = &req->rq_snd_buf; | |
1741 | ||
1742 | task->tk_rqstp = req; | |
1743 | req->rq_task = task; | |
1744 | xprt_init_connect_cookie(req, req->rq_xprt); | |
1745 | /* | |
1746 | * Set up the xdr_buf length. | |
1747 | * This also indicates that the buffer is XDR encoded already. | |
1748 | */ | |
1749 | xbufp->len = xbufp->head[0].iov_len + xbufp->page_len + | |
1750 | xbufp->tail[0].iov_len; | |
1751 | req->rq_bytes_sent = 0; | |
1752 | } | |
1753 | #endif | |
1754 | ||
21de0a95 | 1755 | static void xprt_init(struct rpc_xprt *xprt, struct net *net) |
c2866763 | 1756 | { |
30c5116b | 1757 | kref_init(&xprt->kref); |
c2866763 CL |
1758 | |
1759 | spin_lock_init(&xprt->transport_lock); | |
1760 | spin_lock_init(&xprt->reserve_lock); | |
75c84151 | 1761 | spin_lock_init(&xprt->queue_lock); |
c2866763 CL |
1762 | |
1763 | INIT_LIST_HEAD(&xprt->free); | |
95f7691d | 1764 | xprt->recv_queue = RB_ROOT; |
944b0429 | 1765 | INIT_LIST_HEAD(&xprt->xmit_queue); |
9e00abc3 | 1766 | #if defined(CONFIG_SUNRPC_BACKCHANNEL) |
f9acac1a RL |
1767 | spin_lock_init(&xprt->bc_pa_lock); |
1768 | INIT_LIST_HEAD(&xprt->bc_pa_list); | |
9e00abc3 | 1769 | #endif /* CONFIG_SUNRPC_BACKCHANNEL */ |
80b14d5e | 1770 | INIT_LIST_HEAD(&xprt->xprt_switch); |
f9acac1a | 1771 | |
c2866763 CL |
1772 | xprt->last_used = jiffies; |
1773 | xprt->cwnd = RPC_INITCWND; | |
a509050b | 1774 | xprt->bind_index = 0; |
c2866763 CL |
1775 | |
1776 | rpc_init_wait_queue(&xprt->binding, "xprt_binding"); | |
1777 | rpc_init_wait_queue(&xprt->pending, "xprt_pending"); | |
79c99152 | 1778 | rpc_init_wait_queue(&xprt->sending, "xprt_sending"); |
c2866763 CL |
1779 | rpc_init_priority_wait_queue(&xprt->backlog, "xprt_backlog"); |
1780 | ||
c2866763 CL |
1781 | xprt_init_xid(xprt); |
1782 | ||
21de0a95 | 1783 | xprt->xprt_net = get_net(net); |
8d9266ff TM |
1784 | } |
1785 | ||
1786 | /** | |
1787 | * xprt_create_transport - create an RPC transport | |
1788 | * @args: rpc transport creation arguments | |
1789 | * | |
1790 | */ | |
1791 | struct rpc_xprt *xprt_create_transport(struct xprt_create *args) | |
1792 | { | |
1793 | struct rpc_xprt *xprt; | |
1794 | struct xprt_class *t; | |
1795 | ||
1796 | spin_lock(&xprt_list_lock); | |
1797 | list_for_each_entry(t, &xprt_list, list) { | |
1798 | if (t->ident == args->ident) { | |
1799 | spin_unlock(&xprt_list_lock); | |
1800 | goto found; | |
1801 | } | |
1802 | } | |
1803 | spin_unlock(&xprt_list_lock); | |
3c45ddf8 | 1804 | dprintk("RPC: transport (%d) not supported\n", args->ident); |
8d9266ff TM |
1805 | return ERR_PTR(-EIO); |
1806 | ||
1807 | found: | |
1808 | xprt = t->setup(args); | |
1809 | if (IS_ERR(xprt)) { | |
1810 | dprintk("RPC: xprt_create_transport: failed, %ld\n", | |
1811 | -PTR_ERR(xprt)); | |
21de0a95 | 1812 | goto out; |
8d9266ff | 1813 | } |
33d90ac0 BF |
1814 | if (args->flags & XPRT_CREATE_NO_IDLE_TIMEOUT) |
1815 | xprt->idle_timeout = 0; | |
21de0a95 TM |
1816 | INIT_WORK(&xprt->task_cleanup, xprt_autoclose); |
1817 | if (xprt_has_timer(xprt)) | |
ff861c4d | 1818 | timer_setup(&xprt->timer, xprt_init_autodisconnect, 0); |
21de0a95 | 1819 | else |
ff861c4d | 1820 | timer_setup(&xprt->timer, NULL, 0); |
4e0038b6 TM |
1821 | |
1822 | if (strlen(args->servername) > RPC_MAXNETNAMELEN) { | |
1823 | xprt_destroy(xprt); | |
1824 | return ERR_PTR(-EINVAL); | |
1825 | } | |
1826 | xprt->servername = kstrdup(args->servername, GFP_KERNEL); | |
1827 | if (xprt->servername == NULL) { | |
1828 | xprt_destroy(xprt); | |
1829 | return ERR_PTR(-ENOMEM); | |
1830 | } | |
1831 | ||
3f940098 | 1832 | rpc_xprt_debugfs_register(xprt); |
388f0c77 | 1833 | |
46121cf7 | 1834 | dprintk("RPC: created transport %p with %u slots\n", xprt, |
c2866763 | 1835 | xprt->max_reqs); |
21de0a95 | 1836 | out: |
c2866763 CL |
1837 | return xprt; |
1838 | } | |
1839 | ||
528fd354 TM |
1840 | static void xprt_destroy_cb(struct work_struct *work) |
1841 | { | |
1842 | struct rpc_xprt *xprt = | |
1843 | container_of(work, struct rpc_xprt, task_cleanup); | |
1844 | ||
1845 | rpc_xprt_debugfs_unregister(xprt); | |
1846 | rpc_destroy_wait_queue(&xprt->binding); | |
1847 | rpc_destroy_wait_queue(&xprt->pending); | |
1848 | rpc_destroy_wait_queue(&xprt->sending); | |
1849 | rpc_destroy_wait_queue(&xprt->backlog); | |
1850 | kfree(xprt->servername); | |
1851 | /* | |
1852 | * Tear down transport state and free the rpc_xprt | |
1853 | */ | |
1854 | xprt->ops->destroy(xprt); | |
1855 | } | |
1856 | ||
9903cd1c CL |
1857 | /** |
1858 | * xprt_destroy - destroy an RPC transport, killing off all requests. | |
a8de240a | 1859 | * @xprt: transport to destroy |
9903cd1c | 1860 | * |
1da177e4 | 1861 | */ |
a8de240a | 1862 | static void xprt_destroy(struct rpc_xprt *xprt) |
1da177e4 | 1863 | { |
46121cf7 | 1864 | dprintk("RPC: destroying transport %p\n", xprt); |
79234c3d | 1865 | |
528fd354 TM |
1866 | /* |
1867 | * Exclude transport connect/disconnect handlers and autoclose | |
1868 | */ | |
79234c3d TM |
1869 | wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_UNINTERRUPTIBLE); |
1870 | ||
0065db32 | 1871 | del_timer_sync(&xprt->timer); |
c8541ecd CL |
1872 | |
1873 | /* | |
528fd354 TM |
1874 | * Destroy sockets etc from the system workqueue so they can |
1875 | * safely flush receive work running on rpciod. | |
c8541ecd | 1876 | */ |
528fd354 TM |
1877 | INIT_WORK(&xprt->task_cleanup, xprt_destroy_cb); |
1878 | schedule_work(&xprt->task_cleanup); | |
6b6ca86b | 1879 | } |
1da177e4 | 1880 | |
30c5116b TM |
1881 | static void xprt_destroy_kref(struct kref *kref) |
1882 | { | |
1883 | xprt_destroy(container_of(kref, struct rpc_xprt, kref)); | |
1884 | } | |
1885 | ||
1886 | /** | |
1887 | * xprt_get - return a reference to an RPC transport. | |
1888 | * @xprt: pointer to the transport | |
1889 | * | |
1890 | */ | |
1891 | struct rpc_xprt *xprt_get(struct rpc_xprt *xprt) | |
1892 | { | |
1893 | if (xprt != NULL && kref_get_unless_zero(&xprt->kref)) | |
1894 | return xprt; | |
1895 | return NULL; | |
1896 | } | |
1897 | EXPORT_SYMBOL_GPL(xprt_get); | |
1898 | ||
6b6ca86b TM |
1899 | /** |
1900 | * xprt_put - release a reference to an RPC transport. | |
1901 | * @xprt: pointer to the transport | |
1902 | * | |
1903 | */ | |
1904 | void xprt_put(struct rpc_xprt *xprt) | |
1905 | { | |
30c5116b TM |
1906 | if (xprt != NULL) |
1907 | kref_put(&xprt->kref, xprt_destroy_kref); | |
6b6ca86b | 1908 | } |
5d252f90 | 1909 | EXPORT_SYMBOL_GPL(xprt_put); |