Commit | Line | Data |
---|---|---|
457c8996 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
2 | /* |
3 | * linux/net/sunrpc/sched.c | |
4 | * | |
5 | * Scheduling for synchronous and asynchronous RPC requests. | |
6 | * | |
7 | * Copyright (C) 1996 Olaf Kirch, <okir@monad.swb.de> | |
cca5172a | 8 | * |
1da177e4 LT |
9 | * TCP NFS related read + write fixes |
10 | * (C) 1999 Dave Airlie, University of Limerick, Ireland <airlied@linux.ie> | |
11 | */ | |
12 | ||
13 | #include <linux/module.h> | |
14 | ||
15 | #include <linux/sched.h> | |
16 | #include <linux/interrupt.h> | |
17 | #include <linux/slab.h> | |
18 | #include <linux/mempool.h> | |
19 | #include <linux/smp.h> | |
1da177e4 | 20 | #include <linux/spinlock.h> |
4a3e2f71 | 21 | #include <linux/mutex.h> |
d310310c | 22 | #include <linux/freezer.h> |
a1231fda | 23 | #include <linux/sched/mm.h> |
1da177e4 LT |
24 | |
25 | #include <linux/sunrpc/clnt.h> | |
9dfe52a9 | 26 | #include <linux/sunrpc/metrics.h> |
1da177e4 | 27 | |
6951867b BH |
28 | #include "sunrpc.h" |
29 | ||
82b0a4c3 TM |
30 | #define CREATE_TRACE_POINTS |
31 | #include <trace/events/sunrpc.h> | |
32 | ||
1da177e4 LT |
33 | /* |
34 | * RPC slabs and memory pools | |
35 | */ | |
36 | #define RPC_BUFFER_MAXSIZE (2048) | |
37 | #define RPC_BUFFER_POOLSIZE (8) | |
38 | #define RPC_TASK_POOLSIZE (8) | |
e18b890b CL |
39 | static struct kmem_cache *rpc_task_slabp __read_mostly; |
40 | static struct kmem_cache *rpc_buffer_slabp __read_mostly; | |
ba89966c ED |
41 | static mempool_t *rpc_task_mempool __read_mostly; |
42 | static mempool_t *rpc_buffer_mempool __read_mostly; | |
1da177e4 | 43 | |
65f27f38 | 44 | static void rpc_async_schedule(struct work_struct *); |
bde8f00c | 45 | static void rpc_release_task(struct rpc_task *task); |
7e0a0e38 | 46 | static void __rpc_queue_timer_fn(struct work_struct *); |
1da177e4 | 47 | |
1da177e4 LT |
48 | /* |
49 | * RPC tasks sit here while waiting for conditions to improve. | |
50 | */ | |
a4a87499 | 51 | static struct rpc_wait_queue delay_queue; |
1da177e4 | 52 | |
1da177e4 LT |
53 | /* |
54 | * rpciod-related stuff | |
55 | */ | |
40a5f1b1 TM |
56 | struct workqueue_struct *rpciod_workqueue __read_mostly; |
57 | struct workqueue_struct *xprtiod_workqueue __read_mostly; | |
675dd90a | 58 | EXPORT_SYMBOL_GPL(xprtiod_workqueue); |
1da177e4 | 59 | |
33e5c765 TM |
60 | gfp_t rpc_task_gfp_mask(void) |
61 | { | |
62 | if (current->flags & PF_WQ_WORKER) | |
63 | return GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN; | |
64 | return GFP_KERNEL; | |
65 | } | |
4b8dbdfb | 66 | EXPORT_SYMBOL_GPL(rpc_task_gfp_mask); |
33e5c765 | 67 | |
39494194 TM |
68 | bool rpc_task_set_rpc_status(struct rpc_task *task, int rpc_status) |
69 | { | |
70 | if (cmpxchg(&task->tk_rpc_status, 0, rpc_status) == 0) | |
71 | return true; | |
72 | return false; | |
73 | } | |
74 | ||
5efd1876 TM |
75 | unsigned long |
76 | rpc_task_timeout(const struct rpc_task *task) | |
77 | { | |
78 | unsigned long timeout = READ_ONCE(task->tk_timeout); | |
79 | ||
80 | if (timeout != 0) { | |
81 | unsigned long now = jiffies; | |
82 | if (time_before(now, timeout)) | |
83 | return timeout - now; | |
84 | } | |
85 | return 0; | |
86 | } | |
87 | EXPORT_SYMBOL_GPL(rpc_task_timeout); | |
88 | ||
1da177e4 LT |
89 | /* |
90 | * Disable the timer for a given RPC task. Should be called with | |
91 | * queue->lock and bh_disabled in order to avoid races within | |
92 | * rpc_run_timer(). | |
93 | */ | |
5d00837b | 94 | static void |
eb276c0e | 95 | __rpc_disable_timer(struct rpc_wait_queue *queue, struct rpc_task *task) |
1da177e4 | 96 | { |
6b2e6856 | 97 | if (list_empty(&task->u.tk_wait.timer_list)) |
36df9aae | 98 | return; |
1da177e4 | 99 | task->tk_timeout = 0; |
36df9aae | 100 | list_del(&task->u.tk_wait.timer_list); |
eb276c0e | 101 | if (list_empty(&queue->timer_list.list)) |
7e0a0e38 | 102 | cancel_delayed_work(&queue->timer_list.dwork); |
36df9aae TM |
103 | } |
104 | ||
105 | static void | |
106 | rpc_set_queue_timer(struct rpc_wait_queue *queue, unsigned long expires) | |
107 | { | |
7e0a0e38 TM |
108 | unsigned long now = jiffies; |
109 | queue->timer_list.expires = expires; | |
110 | if (time_before_eq(expires, now)) | |
111 | expires = 0; | |
112 | else | |
113 | expires -= now; | |
114 | mod_delayed_work(rpciod_workqueue, &queue->timer_list.dwork, expires); | |
1da177e4 LT |
115 | } |
116 | ||
1da177e4 LT |
117 | /* |
118 | * Set up a timer for the current task. | |
119 | */ | |
5d00837b | 120 | static void |
6b2e6856 TM |
121 | __rpc_add_timer(struct rpc_wait_queue *queue, struct rpc_task *task, |
122 | unsigned long timeout) | |
1da177e4 | 123 | { |
6b2e6856 | 124 | task->tk_timeout = timeout; |
7e0a0e38 TM |
125 | if (list_empty(&queue->timer_list.list) || time_before(timeout, queue->timer_list.expires)) |
126 | rpc_set_queue_timer(queue, timeout); | |
eb276c0e | 127 | list_add(&task->u.tk_wait.timer_list, &queue->timer_list.list); |
1da177e4 LT |
128 | } |
129 | ||
c05eecf6 TM |
130 | static void rpc_set_waitqueue_priority(struct rpc_wait_queue *queue, int priority) |
131 | { | |
edd2e36f | 132 | if (queue->priority != priority) { |
edd2e36f | 133 | queue->priority = priority; |
f42f7c28 | 134 | queue->nr = 1U << priority; |
edd2e36f | 135 | } |
c05eecf6 TM |
136 | } |
137 | ||
c05eecf6 TM |
138 | static void rpc_reset_waitqueue_priority(struct rpc_wait_queue *queue) |
139 | { | |
140 | rpc_set_waitqueue_priority(queue, queue->maxpriority); | |
c05eecf6 TM |
141 | } |
142 | ||
1da177e4 | 143 | /* |
f42f7c28 | 144 | * Add a request to a queue list |
1da177e4 | 145 | */ |
f42f7c28 TM |
146 | static void |
147 | __rpc_list_enqueue_task(struct list_head *q, struct rpc_task *task) | |
1da177e4 | 148 | { |
1da177e4 LT |
149 | struct rpc_task *t; |
150 | ||
1da177e4 | 151 | list_for_each_entry(t, q, u.tk_wait.list) { |
3ff7576d | 152 | if (t->tk_owner == task->tk_owner) { |
f42f7c28 TM |
153 | list_add_tail(&task->u.tk_wait.links, |
154 | &t->u.tk_wait.links); | |
155 | /* Cache the queue head in task->u.tk_wait.list */ | |
156 | task->u.tk_wait.list.next = q; | |
157 | task->u.tk_wait.list.prev = NULL; | |
1da177e4 LT |
158 | return; |
159 | } | |
160 | } | |
f42f7c28 | 161 | INIT_LIST_HEAD(&task->u.tk_wait.links); |
1da177e4 LT |
162 | list_add_tail(&task->u.tk_wait.list, q); |
163 | } | |
164 | ||
f42f7c28 TM |
165 | /* |
166 | * Remove request from a queue list | |
167 | */ | |
168 | static void | |
169 | __rpc_list_dequeue_task(struct rpc_task *task) | |
170 | { | |
171 | struct list_head *q; | |
172 | struct rpc_task *t; | |
173 | ||
174 | if (task->u.tk_wait.list.prev == NULL) { | |
175 | list_del(&task->u.tk_wait.links); | |
176 | return; | |
177 | } | |
178 | if (!list_empty(&task->u.tk_wait.links)) { | |
179 | t = list_first_entry(&task->u.tk_wait.links, | |
180 | struct rpc_task, | |
181 | u.tk_wait.links); | |
182 | /* Assume __rpc_list_enqueue_task() cached the queue head */ | |
183 | q = t->u.tk_wait.list.next; | |
184 | list_add_tail(&t->u.tk_wait.list, q); | |
185 | list_del(&task->u.tk_wait.links); | |
186 | } | |
187 | list_del(&task->u.tk_wait.list); | |
188 | } | |
189 | ||
190 | /* | |
191 | * Add new request to a priority queue. | |
192 | */ | |
193 | static void __rpc_add_wait_queue_priority(struct rpc_wait_queue *queue, | |
194 | struct rpc_task *task, | |
195 | unsigned char queue_priority) | |
196 | { | |
197 | if (unlikely(queue_priority > queue->maxpriority)) | |
198 | queue_priority = queue->maxpriority; | |
199 | __rpc_list_enqueue_task(&queue->tasks[queue_priority], task); | |
200 | } | |
201 | ||
1da177e4 LT |
202 | /* |
203 | * Add new request to wait queue. | |
1da177e4 | 204 | */ |
3b27bad7 TM |
205 | static void __rpc_add_wait_queue(struct rpc_wait_queue *queue, |
206 | struct rpc_task *task, | |
207 | unsigned char queue_priority) | |
1da177e4 | 208 | { |
6b2e6856 | 209 | INIT_LIST_HEAD(&task->u.tk_wait.timer_list); |
1da177e4 | 210 | if (RPC_IS_PRIORITY(queue)) |
3b27bad7 | 211 | __rpc_add_wait_queue_priority(queue, task, queue_priority); |
1da177e4 LT |
212 | else |
213 | list_add_tail(&task->u.tk_wait.list, &queue->tasks[0]); | |
96ef13b2 | 214 | task->tk_waitqueue = queue; |
e19b63da | 215 | queue->qlen++; |
1166fde6 TM |
216 | /* barrier matches the read in rpc_wake_up_task_queue_locked() */ |
217 | smp_wmb(); | |
1da177e4 | 218 | rpc_set_queued(task); |
1da177e4 LT |
219 | } |
220 | ||
221 | /* | |
222 | * Remove request from a priority queue. | |
223 | */ | |
224 | static void __rpc_remove_wait_queue_priority(struct rpc_task *task) | |
225 | { | |
f42f7c28 | 226 | __rpc_list_dequeue_task(task); |
1da177e4 LT |
227 | } |
228 | ||
229 | /* | |
230 | * Remove request from queue. | |
231 | * Note: must be called with spin lock held. | |
232 | */ | |
96ef13b2 | 233 | static void __rpc_remove_wait_queue(struct rpc_wait_queue *queue, struct rpc_task *task) |
1da177e4 | 234 | { |
eb276c0e | 235 | __rpc_disable_timer(queue, task); |
1da177e4 LT |
236 | if (RPC_IS_PRIORITY(queue)) |
237 | __rpc_remove_wait_queue_priority(task); | |
f42f7c28 TM |
238 | else |
239 | list_del(&task->u.tk_wait.list); | |
e19b63da | 240 | queue->qlen--; |
1da177e4 LT |
241 | } |
242 | ||
3ff7576d | 243 | static void __rpc_init_priority_wait_queue(struct rpc_wait_queue *queue, const char *qname, unsigned char nr_queues) |
1da177e4 LT |
244 | { |
245 | int i; | |
246 | ||
247 | spin_lock_init(&queue->lock); | |
248 | for (i = 0; i < ARRAY_SIZE(queue->tasks); i++) | |
249 | INIT_LIST_HEAD(&queue->tasks[i]); | |
3ff7576d | 250 | queue->maxpriority = nr_queues - 1; |
1da177e4 | 251 | rpc_reset_waitqueue_priority(queue); |
36df9aae | 252 | queue->qlen = 0; |
7e0a0e38 | 253 | queue->timer_list.expires = 0; |
66eb3add | 254 | INIT_DELAYED_WORK(&queue->timer_list.dwork, __rpc_queue_timer_fn); |
36df9aae | 255 | INIT_LIST_HEAD(&queue->timer_list.list); |
2f09c242 | 256 | rpc_assign_waitqueue_name(queue, qname); |
1da177e4 LT |
257 | } |
258 | ||
259 | void rpc_init_priority_wait_queue(struct rpc_wait_queue *queue, const char *qname) | |
260 | { | |
3ff7576d | 261 | __rpc_init_priority_wait_queue(queue, qname, RPC_NR_PRIORITY); |
1da177e4 | 262 | } |
689cf5c1 | 263 | EXPORT_SYMBOL_GPL(rpc_init_priority_wait_queue); |
1da177e4 LT |
264 | |
265 | void rpc_init_wait_queue(struct rpc_wait_queue *queue, const char *qname) | |
266 | { | |
3ff7576d | 267 | __rpc_init_priority_wait_queue(queue, qname, 1); |
1da177e4 | 268 | } |
e8914c65 | 269 | EXPORT_SYMBOL_GPL(rpc_init_wait_queue); |
1da177e4 | 270 | |
f6a1cc89 TM |
271 | void rpc_destroy_wait_queue(struct rpc_wait_queue *queue) |
272 | { | |
7e0a0e38 | 273 | cancel_delayed_work_sync(&queue->timer_list.dwork); |
f6a1cc89 TM |
274 | } |
275 | EXPORT_SYMBOL_GPL(rpc_destroy_wait_queue); | |
276 | ||
dfd01f02 | 277 | static int rpc_wait_bit_killable(struct wait_bit_key *key, int mode) |
44c28873 | 278 | { |
f5d39b02 | 279 | schedule(); |
dfd01f02 PZ |
280 | if (signal_pending_state(mode, current)) |
281 | return -ERESTARTSYS; | |
44c28873 TM |
282 | return 0; |
283 | } | |
284 | ||
1306729b | 285 | #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS) |
c44fe705 TM |
286 | static void rpc_task_set_debuginfo(struct rpc_task *task) |
287 | { | |
0392dd51 | 288 | struct rpc_clnt *clnt = task->tk_client; |
c44fe705 | 289 | |
0392dd51 CL |
290 | /* Might be a task carrying a reverse-direction operation */ |
291 | if (!clnt) { | |
292 | static atomic_t rpc_pid; | |
293 | ||
294 | task->tk_pid = atomic_inc_return(&rpc_pid); | |
295 | return; | |
296 | } | |
297 | ||
298 | task->tk_pid = atomic_inc_return(&clnt->cl_pid); | |
c44fe705 TM |
299 | } |
300 | #else | |
301 | static inline void rpc_task_set_debuginfo(struct rpc_task *task) | |
302 | { | |
303 | } | |
304 | #endif | |
305 | ||
e6b3c4db TM |
306 | static void rpc_set_active(struct rpc_task *task) |
307 | { | |
c44fe705 | 308 | rpc_task_set_debuginfo(task); |
58f9612c | 309 | set_bit(RPC_TASK_ACTIVE, &task->tk_runstate); |
e671edb9 | 310 | trace_rpc_task_begin(task, NULL); |
e6b3c4db TM |
311 | } |
312 | ||
44c28873 TM |
313 | /* |
314 | * Mark an RPC call as having completed by clearing the 'active' bit | |
bf294b41 | 315 | * and then waking up all tasks that were sleeping. |
44c28873 | 316 | */ |
bf294b41 | 317 | static int rpc_complete_task(struct rpc_task *task) |
44c28873 | 318 | { |
bf294b41 TM |
319 | void *m = &task->tk_runstate; |
320 | wait_queue_head_t *wq = bit_waitqueue(m, RPC_TASK_ACTIVE); | |
321 | struct wait_bit_key k = __WAIT_BIT_KEY_INITIALIZER(m, RPC_TASK_ACTIVE); | |
322 | unsigned long flags; | |
323 | int ret; | |
324 | ||
e671edb9 | 325 | trace_rpc_task_complete(task, NULL); |
82b0a4c3 | 326 | |
bf294b41 | 327 | spin_lock_irqsave(&wq->lock, flags); |
e6b3c4db | 328 | clear_bit(RPC_TASK_ACTIVE, &task->tk_runstate); |
bf294b41 TM |
329 | ret = atomic_dec_and_test(&task->tk_count); |
330 | if (waitqueue_active(wq)) | |
ac5be6b4 | 331 | __wake_up_locked_key(wq, TASK_NORMAL, &k); |
bf294b41 TM |
332 | spin_unlock_irqrestore(&wq->lock, flags); |
333 | return ret; | |
44c28873 TM |
334 | } |
335 | ||
336 | /* | |
337 | * Allow callers to wait for completion of an RPC call | |
bf294b41 TM |
338 | * |
339 | * Note the use of out_of_line_wait_on_bit() rather than wait_on_bit() | |
340 | * to enforce taking of the wq->lock and hence avoid races with | |
341 | * rpc_complete_task(). | |
44c28873 | 342 | */ |
f5d39b02 | 343 | int rpc_wait_for_completion_task(struct rpc_task *task) |
44c28873 | 344 | { |
bf294b41 | 345 | return out_of_line_wait_on_bit(&task->tk_runstate, RPC_TASK_ACTIVE, |
f5d39b02 | 346 | rpc_wait_bit_killable, TASK_KILLABLE|TASK_FREEZABLE_UNSAFE); |
44c28873 | 347 | } |
f5d39b02 | 348 | EXPORT_SYMBOL_GPL(rpc_wait_for_completion_task); |
44c28873 | 349 | |
1da177e4 LT |
350 | /* |
351 | * Make an RPC task runnable. | |
352 | * | |
506026c3 JL |
353 | * Note: If the task is ASYNC, and is being made runnable after sitting on an |
354 | * rpc_wait_queue, this must be called with the queue spinlock held to protect | |
355 | * the wait queue operation. | |
a3c3cac5 TM |
356 | * Note the ordering of rpc_test_and_set_running() and rpc_clear_queued(), |
357 | * which is needed to ensure that __rpc_execute() doesn't loop (due to the | |
358 | * lockless RPC_IS_QUEUED() test) before we've had a chance to test | |
359 | * the RPC_TASK_RUNNING flag. | |
1da177e4 | 360 | */ |
f1dc237c TM |
361 | static void rpc_make_runnable(struct workqueue_struct *wq, |
362 | struct rpc_task *task) | |
1da177e4 | 363 | { |
a3c3cac5 TM |
364 | bool need_wakeup = !rpc_test_and_set_running(task); |
365 | ||
1da177e4 | 366 | rpc_clear_queued(task); |
a3c3cac5 | 367 | if (!need_wakeup) |
cc4dc59e | 368 | return; |
1da177e4 | 369 | if (RPC_IS_ASYNC(task)) { |
65f27f38 | 370 | INIT_WORK(&task->u.tk_work, rpc_async_schedule); |
f1dc237c | 371 | queue_work(wq, &task->u.tk_work); |
1da177e4 | 372 | } else |
96651ab3 | 373 | wake_up_bit(&task->tk_runstate, RPC_TASK_QUEUED); |
1da177e4 LT |
374 | } |
375 | ||
1da177e4 LT |
376 | /* |
377 | * Prepare for sleeping on a wait queue. | |
378 | * By always appending tasks to the list we ensure FIFO behavior. | |
379 | * NB: An RPC task will only receive interrupt-driven events as long | |
380 | * as it's on a wait queue. | |
381 | */ | |
1fab7dc4 | 382 | static void __rpc_do_sleep_on_priority(struct rpc_wait_queue *q, |
3b27bad7 | 383 | struct rpc_task *task, |
3b27bad7 | 384 | unsigned char queue_priority) |
1da177e4 | 385 | { |
e671edb9 | 386 | trace_rpc_task_sleep(task, q); |
82b0a4c3 | 387 | |
3b27bad7 | 388 | __rpc_add_wait_queue(q, task, queue_priority); |
6b2e6856 TM |
389 | } |
390 | ||
1fab7dc4 TM |
391 | static void __rpc_sleep_on_priority(struct rpc_wait_queue *q, |
392 | struct rpc_task *task, | |
393 | unsigned char queue_priority) | |
394 | { | |
395 | if (WARN_ON_ONCE(RPC_IS_QUEUED(task))) | |
396 | return; | |
397 | __rpc_do_sleep_on_priority(q, task, queue_priority); | |
398 | } | |
399 | ||
6b2e6856 TM |
400 | static void __rpc_sleep_on_priority_timeout(struct rpc_wait_queue *q, |
401 | struct rpc_task *task, unsigned long timeout, | |
402 | unsigned char queue_priority) | |
403 | { | |
1fab7dc4 TM |
404 | if (WARN_ON_ONCE(RPC_IS_QUEUED(task))) |
405 | return; | |
6b2e6856 | 406 | if (time_is_after_jiffies(timeout)) { |
1fab7dc4 | 407 | __rpc_do_sleep_on_priority(q, task, queue_priority); |
6b2e6856 TM |
408 | __rpc_add_timer(q, task, timeout); |
409 | } else | |
410 | task->tk_status = -ETIMEDOUT; | |
1da177e4 LT |
411 | } |
412 | ||
87150aae TM |
413 | static void rpc_set_tk_callback(struct rpc_task *task, rpc_action action) |
414 | { | |
415 | if (action && !WARN_ON_ONCE(task->tk_callback != NULL)) | |
416 | task->tk_callback = action; | |
417 | } | |
418 | ||
419 | static bool rpc_sleep_check_activated(struct rpc_task *task) | |
1da177e4 | 420 | { |
58f9612c | 421 | /* We shouldn't ever put an inactive task to sleep */ |
87150aae | 422 | if (WARN_ON_ONCE(!RPC_IS_ACTIVATED(task))) { |
e454a7a8 WAA |
423 | task->tk_status = -EIO; |
424 | rpc_put_task_async(task); | |
87150aae | 425 | return false; |
e454a7a8 | 426 | } |
87150aae TM |
427 | return true; |
428 | } | |
429 | ||
6b2e6856 TM |
430 | void rpc_sleep_on_timeout(struct rpc_wait_queue *q, struct rpc_task *task, |
431 | rpc_action action, unsigned long timeout) | |
432 | { | |
433 | if (!rpc_sleep_check_activated(task)) | |
434 | return; | |
435 | ||
436 | rpc_set_tk_callback(task, action); | |
437 | ||
438 | /* | |
439 | * Protect the queue operations. | |
440 | */ | |
c049f8ea | 441 | spin_lock(&q->lock); |
6b2e6856 | 442 | __rpc_sleep_on_priority_timeout(q, task, timeout, task->tk_priority); |
c049f8ea | 443 | spin_unlock(&q->lock); |
6b2e6856 TM |
444 | } |
445 | EXPORT_SYMBOL_GPL(rpc_sleep_on_timeout); | |
446 | ||
87150aae TM |
447 | void rpc_sleep_on(struct rpc_wait_queue *q, struct rpc_task *task, |
448 | rpc_action action) | |
449 | { | |
450 | if (!rpc_sleep_check_activated(task)) | |
451 | return; | |
452 | ||
453 | rpc_set_tk_callback(task, action); | |
e6b3c4db | 454 | |
6b2e6856 | 455 | WARN_ON_ONCE(task->tk_timeout != 0); |
1da177e4 LT |
456 | /* |
457 | * Protect the queue operations. | |
458 | */ | |
c049f8ea | 459 | spin_lock(&q->lock); |
87150aae | 460 | __rpc_sleep_on_priority(q, task, task->tk_priority); |
c049f8ea | 461 | spin_unlock(&q->lock); |
1da177e4 | 462 | } |
e8914c65 | 463 | EXPORT_SYMBOL_GPL(rpc_sleep_on); |
1da177e4 | 464 | |
6b2e6856 TM |
465 | void rpc_sleep_on_priority_timeout(struct rpc_wait_queue *q, |
466 | struct rpc_task *task, unsigned long timeout, int priority) | |
467 | { | |
468 | if (!rpc_sleep_check_activated(task)) | |
469 | return; | |
470 | ||
471 | priority -= RPC_PRIORITY_LOW; | |
472 | /* | |
473 | * Protect the queue operations. | |
474 | */ | |
c049f8ea | 475 | spin_lock(&q->lock); |
6b2e6856 | 476 | __rpc_sleep_on_priority_timeout(q, task, timeout, priority); |
c049f8ea | 477 | spin_unlock(&q->lock); |
6b2e6856 TM |
478 | } |
479 | EXPORT_SYMBOL_GPL(rpc_sleep_on_priority_timeout); | |
480 | ||
3b27bad7 | 481 | void rpc_sleep_on_priority(struct rpc_wait_queue *q, struct rpc_task *task, |
8357a9b6 | 482 | int priority) |
3b27bad7 | 483 | { |
87150aae | 484 | if (!rpc_sleep_check_activated(task)) |
e454a7a8 | 485 | return; |
87150aae | 486 | |
6b2e6856 | 487 | WARN_ON_ONCE(task->tk_timeout != 0); |
8357a9b6 | 488 | priority -= RPC_PRIORITY_LOW; |
3b27bad7 TM |
489 | /* |
490 | * Protect the queue operations. | |
491 | */ | |
c049f8ea | 492 | spin_lock(&q->lock); |
8357a9b6 | 493 | __rpc_sleep_on_priority(q, task, priority); |
c049f8ea | 494 | spin_unlock(&q->lock); |
3b27bad7 | 495 | } |
1e1093c7 | 496 | EXPORT_SYMBOL_GPL(rpc_sleep_on_priority); |
3b27bad7 | 497 | |
1da177e4 | 498 | /** |
f1dc237c TM |
499 | * __rpc_do_wake_up_task_on_wq - wake up a single rpc_task |
500 | * @wq: workqueue on which to run task | |
96ef13b2 | 501 | * @queue: wait queue |
1da177e4 LT |
502 | * @task: task to be woken up |
503 | * | |
504 | * Caller must hold queue->lock, and have cleared the task queued flag. | |
505 | */ | |
f1dc237c TM |
506 | static void __rpc_do_wake_up_task_on_wq(struct workqueue_struct *wq, |
507 | struct rpc_wait_queue *queue, | |
508 | struct rpc_task *task) | |
1da177e4 | 509 | { |
1da177e4 LT |
510 | /* Has the task been executed yet? If not, we cannot wake it up! */ |
511 | if (!RPC_IS_ACTIVATED(task)) { | |
512 | printk(KERN_ERR "RPC: Inactive task (%p) being woken up!\n", task); | |
513 | return; | |
514 | } | |
515 | ||
e671edb9 | 516 | trace_rpc_task_wakeup(task, queue); |
82b0a4c3 | 517 | |
96ef13b2 | 518 | __rpc_remove_wait_queue(queue, task); |
1da177e4 | 519 | |
f1dc237c | 520 | rpc_make_runnable(wq, task); |
1da177e4 LT |
521 | } |
522 | ||
523 | /* | |
96ef13b2 | 524 | * Wake up a queued task while the queue lock is being held |
1da177e4 | 525 | */ |
359c48c0 TM |
526 | static struct rpc_task * |
527 | rpc_wake_up_task_on_wq_queue_action_locked(struct workqueue_struct *wq, | |
528 | struct rpc_wait_queue *queue, struct rpc_task *task, | |
529 | bool (*action)(struct rpc_task *, void *), void *data) | |
1da177e4 | 530 | { |
1166fde6 TM |
531 | if (RPC_IS_QUEUED(task)) { |
532 | smp_rmb(); | |
359c48c0 TM |
533 | if (task->tk_waitqueue == queue) { |
534 | if (action == NULL || action(task, data)) { | |
535 | __rpc_do_wake_up_task_on_wq(wq, queue, task); | |
536 | return task; | |
537 | } | |
538 | } | |
1166fde6 | 539 | } |
359c48c0 TM |
540 | return NULL; |
541 | } | |
542 | ||
f1dc237c TM |
543 | /* |
544 | * Wake up a queued task while the queue lock is being held | |
545 | */ | |
691b45dd CL |
546 | static void rpc_wake_up_task_queue_locked(struct rpc_wait_queue *queue, |
547 | struct rpc_task *task) | |
f1dc237c | 548 | { |
691b45dd CL |
549 | rpc_wake_up_task_on_wq_queue_action_locked(rpciod_workqueue, queue, |
550 | task, NULL, NULL); | |
2275cde4 TM |
551 | } |
552 | ||
1da177e4 | 553 | /* |
96ef13b2 | 554 | * Wake up a task on a specific queue |
1da177e4 | 555 | */ |
96ef13b2 | 556 | void rpc_wake_up_queued_task(struct rpc_wait_queue *queue, struct rpc_task *task) |
1da177e4 | 557 | { |
5ce97039 TM |
558 | if (!RPC_IS_QUEUED(task)) |
559 | return; | |
c049f8ea | 560 | spin_lock(&queue->lock); |
96ef13b2 | 561 | rpc_wake_up_task_queue_locked(queue, task); |
c049f8ea | 562 | spin_unlock(&queue->lock); |
1da177e4 | 563 | } |
96ef13b2 TM |
564 | EXPORT_SYMBOL_GPL(rpc_wake_up_queued_task); |
565 | ||
359c48c0 TM |
566 | static bool rpc_task_action_set_status(struct rpc_task *task, void *status) |
567 | { | |
568 | task->tk_status = *(int *)status; | |
569 | return true; | |
570 | } | |
571 | ||
572 | static void | |
573 | rpc_wake_up_task_queue_set_status_locked(struct rpc_wait_queue *queue, | |
574 | struct rpc_task *task, int status) | |
575 | { | |
576 | rpc_wake_up_task_on_wq_queue_action_locked(rpciod_workqueue, queue, | |
577 | task, rpc_task_action_set_status, &status); | |
578 | } | |
579 | ||
580 | /** | |
581 | * rpc_wake_up_queued_task_set_status - wake up a task and set task->tk_status | |
582 | * @queue: pointer to rpc_wait_queue | |
583 | * @task: pointer to rpc_task | |
584 | * @status: integer error value | |
585 | * | |
586 | * If @task is queued on @queue, then it is woken up, and @task->tk_status is | |
587 | * set to the value of @status. | |
588 | */ | |
589 | void | |
590 | rpc_wake_up_queued_task_set_status(struct rpc_wait_queue *queue, | |
591 | struct rpc_task *task, int status) | |
592 | { | |
593 | if (!RPC_IS_QUEUED(task)) | |
594 | return; | |
c049f8ea | 595 | spin_lock(&queue->lock); |
359c48c0 | 596 | rpc_wake_up_task_queue_set_status_locked(queue, task, status); |
c049f8ea | 597 | spin_unlock(&queue->lock); |
359c48c0 TM |
598 | } |
599 | ||
1da177e4 LT |
600 | /* |
601 | * Wake up the next task on a priority queue. | |
602 | */ | |
961a828d | 603 | static struct rpc_task *__rpc_find_next_queued_priority(struct rpc_wait_queue *queue) |
1da177e4 LT |
604 | { |
605 | struct list_head *q; | |
606 | struct rpc_task *task; | |
607 | ||
5483b904 ZX |
608 | /* |
609 | * Service the privileged queue. | |
610 | */ | |
611 | q = &queue->tasks[RPC_NR_PRIORITY - 1]; | |
612 | if (queue->maxpriority > RPC_PRIORITY_PRIVILEGED && !list_empty(q)) { | |
613 | task = list_first_entry(q, struct rpc_task, u.tk_wait.list); | |
614 | goto out; | |
615 | } | |
616 | ||
1da177e4 | 617 | /* |
3ff7576d | 618 | * Service a batch of tasks from a single owner. |
1da177e4 LT |
619 | */ |
620 | q = &queue->tasks[queue->priority]; | |
fcb170a9 ZX |
621 | if (!list_empty(q) && queue->nr) { |
622 | queue->nr--; | |
f42f7c28 TM |
623 | task = list_first_entry(q, struct rpc_task, u.tk_wait.list); |
624 | goto out; | |
1da177e4 LT |
625 | } |
626 | ||
627 | /* | |
628 | * Service the next queue. | |
629 | */ | |
630 | do { | |
631 | if (q == &queue->tasks[0]) | |
632 | q = &queue->tasks[queue->maxpriority]; | |
633 | else | |
634 | q = q - 1; | |
635 | if (!list_empty(q)) { | |
f42f7c28 | 636 | task = list_first_entry(q, struct rpc_task, u.tk_wait.list); |
1da177e4 LT |
637 | goto new_queue; |
638 | } | |
639 | } while (q != &queue->tasks[queue->priority]); | |
640 | ||
641 | rpc_reset_waitqueue_priority(queue); | |
642 | return NULL; | |
643 | ||
644 | new_queue: | |
645 | rpc_set_waitqueue_priority(queue, (unsigned int)(q - &queue->tasks[0])); | |
1da177e4 | 646 | out: |
1da177e4 LT |
647 | return task; |
648 | } | |
649 | ||
961a828d TM |
650 | static struct rpc_task *__rpc_find_next_queued(struct rpc_wait_queue *queue) |
651 | { | |
652 | if (RPC_IS_PRIORITY(queue)) | |
653 | return __rpc_find_next_queued_priority(queue); | |
654 | if (!list_empty(&queue->tasks[0])) | |
655 | return list_first_entry(&queue->tasks[0], struct rpc_task, u.tk_wait.list); | |
656 | return NULL; | |
657 | } | |
658 | ||
1da177e4 | 659 | /* |
961a828d | 660 | * Wake up the first task on the wait queue. |
1da177e4 | 661 | */ |
f1dc237c TM |
662 | struct rpc_task *rpc_wake_up_first_on_wq(struct workqueue_struct *wq, |
663 | struct rpc_wait_queue *queue, | |
961a828d | 664 | bool (*func)(struct rpc_task *, void *), void *data) |
1da177e4 LT |
665 | { |
666 | struct rpc_task *task = NULL; | |
667 | ||
c049f8ea | 668 | spin_lock(&queue->lock); |
961a828d | 669 | task = __rpc_find_next_queued(queue); |
359c48c0 TM |
670 | if (task != NULL) |
671 | task = rpc_wake_up_task_on_wq_queue_action_locked(wq, queue, | |
672 | task, func, data); | |
c049f8ea | 673 | spin_unlock(&queue->lock); |
1da177e4 LT |
674 | |
675 | return task; | |
676 | } | |
f1dc237c TM |
677 | |
678 | /* | |
679 | * Wake up the first task on the wait queue. | |
680 | */ | |
681 | struct rpc_task *rpc_wake_up_first(struct rpc_wait_queue *queue, | |
682 | bool (*func)(struct rpc_task *, void *), void *data) | |
683 | { | |
684 | return rpc_wake_up_first_on_wq(rpciod_workqueue, queue, func, data); | |
685 | } | |
961a828d TM |
686 | EXPORT_SYMBOL_GPL(rpc_wake_up_first); |
687 | ||
688 | static bool rpc_wake_up_next_func(struct rpc_task *task, void *data) | |
689 | { | |
690 | return true; | |
691 | } | |
692 | ||
693 | /* | |
694 | * Wake up the next task on the wait queue. | |
695 | */ | |
696 | struct rpc_task *rpc_wake_up_next(struct rpc_wait_queue *queue) | |
697 | { | |
698 | return rpc_wake_up_first(queue, rpc_wake_up_next_func, NULL); | |
699 | } | |
e8914c65 | 700 | EXPORT_SYMBOL_GPL(rpc_wake_up_next); |
1da177e4 | 701 | |
e4c72201 TM |
702 | /** |
703 | * rpc_wake_up_locked - wake up all rpc_tasks | |
704 | * @queue: rpc_wait_queue on which the tasks are sleeping | |
705 | * | |
706 | */ | |
707 | static void rpc_wake_up_locked(struct rpc_wait_queue *queue) | |
708 | { | |
709 | struct rpc_task *task; | |
710 | ||
711 | for (;;) { | |
712 | task = __rpc_find_next_queued(queue); | |
713 | if (task == NULL) | |
714 | break; | |
715 | rpc_wake_up_task_queue_locked(queue, task); | |
716 | } | |
717 | } | |
718 | ||
1da177e4 LT |
719 | /** |
720 | * rpc_wake_up - wake up all rpc_tasks | |
721 | * @queue: rpc_wait_queue on which the tasks are sleeping | |
722 | * | |
723 | * Grabs queue->lock | |
724 | */ | |
725 | void rpc_wake_up(struct rpc_wait_queue *queue) | |
726 | { | |
c049f8ea | 727 | spin_lock(&queue->lock); |
e4c72201 TM |
728 | rpc_wake_up_locked(queue); |
729 | spin_unlock(&queue->lock); | |
730 | } | |
731 | EXPORT_SYMBOL_GPL(rpc_wake_up); | |
732 | ||
733 | /** | |
734 | * rpc_wake_up_status_locked - wake up all rpc_tasks and set their status value. | |
735 | * @queue: rpc_wait_queue on which the tasks are sleeping | |
736 | * @status: status value to set | |
737 | */ | |
738 | static void rpc_wake_up_status_locked(struct rpc_wait_queue *queue, int status) | |
739 | { | |
740 | struct rpc_task *task; | |
741 | ||
1da177e4 | 742 | for (;;) { |
e4c72201 TM |
743 | task = __rpc_find_next_queued(queue); |
744 | if (task == NULL) | |
1da177e4 | 745 | break; |
e4c72201 | 746 | rpc_wake_up_task_queue_set_status_locked(queue, task, status); |
1da177e4 | 747 | } |
1da177e4 LT |
748 | } |
749 | ||
750 | /** | |
751 | * rpc_wake_up_status - wake up all rpc_tasks and set their status value. | |
752 | * @queue: rpc_wait_queue on which the tasks are sleeping | |
753 | * @status: status value to set | |
754 | * | |
755 | * Grabs queue->lock | |
756 | */ | |
757 | void rpc_wake_up_status(struct rpc_wait_queue *queue, int status) | |
758 | { | |
c049f8ea | 759 | spin_lock(&queue->lock); |
e4c72201 | 760 | rpc_wake_up_status_locked(queue, status); |
c049f8ea | 761 | spin_unlock(&queue->lock); |
1da177e4 | 762 | } |
e8914c65 | 763 | EXPORT_SYMBOL_GPL(rpc_wake_up_status); |
1da177e4 | 764 | |
7e0a0e38 | 765 | static void __rpc_queue_timer_fn(struct work_struct *work) |
36df9aae | 766 | { |
7e0a0e38 TM |
767 | struct rpc_wait_queue *queue = container_of(work, |
768 | struct rpc_wait_queue, | |
769 | timer_list.dwork.work); | |
36df9aae TM |
770 | struct rpc_task *task, *n; |
771 | unsigned long expires, now, timeo; | |
772 | ||
773 | spin_lock(&queue->lock); | |
774 | expires = now = jiffies; | |
775 | list_for_each_entry_safe(task, n, &queue->timer_list.list, u.tk_wait.timer_list) { | |
6b2e6856 | 776 | timeo = task->tk_timeout; |
36df9aae | 777 | if (time_after_eq(now, timeo)) { |
721a1d38 | 778 | trace_rpc_task_timeout(task, task->tk_action); |
36df9aae TM |
779 | task->tk_status = -ETIMEDOUT; |
780 | rpc_wake_up_task_queue_locked(queue, task); | |
781 | continue; | |
782 | } | |
783 | if (expires == now || time_after(expires, timeo)) | |
784 | expires = timeo; | |
785 | } | |
786 | if (!list_empty(&queue->timer_list.list)) | |
787 | rpc_set_queue_timer(queue, expires); | |
788 | spin_unlock(&queue->lock); | |
789 | } | |
790 | ||
8014793b TM |
791 | static void __rpc_atrun(struct rpc_task *task) |
792 | { | |
6bd14416 TM |
793 | if (task->tk_status == -ETIMEDOUT) |
794 | task->tk_status = 0; | |
8014793b TM |
795 | } |
796 | ||
1da177e4 LT |
797 | /* |
798 | * Run a task at a later time | |
799 | */ | |
8014793b | 800 | void rpc_delay(struct rpc_task *task, unsigned long delay) |
1da177e4 | 801 | { |
6b2e6856 | 802 | rpc_sleep_on_timeout(&delay_queue, task, __rpc_atrun, jiffies + delay); |
1da177e4 | 803 | } |
e8914c65 | 804 | EXPORT_SYMBOL_GPL(rpc_delay); |
1da177e4 | 805 | |
4ce70ada TM |
806 | /* |
807 | * Helper to call task->tk_ops->rpc_call_prepare | |
808 | */ | |
aae2006e | 809 | void rpc_prepare_task(struct rpc_task *task) |
4ce70ada TM |
810 | { |
811 | task->tk_ops->rpc_call_prepare(task, task->tk_calldata); | |
812 | } | |
813 | ||
7fdcf13b TM |
814 | static void |
815 | rpc_init_task_statistics(struct rpc_task *task) | |
816 | { | |
817 | /* Initialize retry counters */ | |
818 | task->tk_garb_retry = 2; | |
819 | task->tk_cred_retry = 2; | |
7fdcf13b TM |
820 | |
821 | /* starting timestamp */ | |
822 | task->tk_start = ktime_get(); | |
823 | } | |
824 | ||
825 | static void | |
826 | rpc_reset_task_statistics(struct rpc_task *task) | |
827 | { | |
828 | task->tk_timeouts = 0; | |
ae67bd38 | 829 | task->tk_flags &= ~(RPC_CALL_MAJORSEEN|RPC_TASK_SENT); |
7fdcf13b TM |
830 | rpc_init_task_statistics(task); |
831 | } | |
832 | ||
d05fdb0c | 833 | /* |
963d8fe5 | 834 | * Helper that calls task->tk_ops->rpc_call_done if it exists |
d05fdb0c | 835 | */ |
abbcf28f | 836 | void rpc_exit_task(struct rpc_task *task) |
d05fdb0c | 837 | { |
a264abad | 838 | trace_rpc_task_end(task, task->tk_action); |
abbcf28f | 839 | task->tk_action = NULL; |
9dfe52a9 DW |
840 | if (task->tk_ops->rpc_count_stats) |
841 | task->tk_ops->rpc_count_stats(task, task->tk_calldata); | |
842 | else if (task->tk_client) | |
843 | rpc_count_iostats(task, task->tk_client->cl_metrics); | |
963d8fe5 | 844 | if (task->tk_ops->rpc_call_done != NULL) { |
b40887e1 | 845 | trace_rpc_task_call_done(task, task->tk_ops->rpc_call_done); |
963d8fe5 | 846 | task->tk_ops->rpc_call_done(task, task->tk_calldata); |
d05fdb0c | 847 | if (task->tk_action != NULL) { |
abbcf28f TM |
848 | /* Always release the RPC slot and buffer memory */ |
849 | xprt_release(task); | |
7fdcf13b | 850 | rpc_reset_task_statistics(task); |
d05fdb0c TM |
851 | } |
852 | } | |
d05fdb0c | 853 | } |
d9b6cd94 | 854 | |
ae67bd38 TM |
855 | void rpc_signal_task(struct rpc_task *task) |
856 | { | |
857 | struct rpc_wait_queue *queue; | |
858 | ||
859 | if (!RPC_IS_ACTIVATED(task)) | |
860 | return; | |
abf8af78 | 861 | |
39494194 TM |
862 | if (!rpc_task_set_rpc_status(task, -ERESTARTSYS)) |
863 | return; | |
abf8af78 | 864 | trace_rpc_task_signalled(task, task->tk_action); |
ae67bd38 TM |
865 | set_bit(RPC_TASK_SIGNALLED, &task->tk_runstate); |
866 | smp_mb__after_atomic(); | |
867 | queue = READ_ONCE(task->tk_waitqueue); | |
868 | if (queue) | |
39494194 | 869 | rpc_wake_up_queued_task(queue, task); |
ae67bd38 TM |
870 | } |
871 | ||
f8423909 TM |
872 | void rpc_task_try_cancel(struct rpc_task *task, int error) |
873 | { | |
874 | struct rpc_wait_queue *queue; | |
875 | ||
876 | if (!rpc_task_set_rpc_status(task, error)) | |
877 | return; | |
878 | queue = READ_ONCE(task->tk_waitqueue); | |
879 | if (queue) | |
880 | rpc_wake_up_queued_task(queue, task); | |
ae67bd38 TM |
881 | } |
882 | ||
d9b6cd94 TM |
883 | void rpc_exit(struct rpc_task *task, int status) |
884 | { | |
885 | task->tk_status = status; | |
886 | task->tk_action = rpc_exit_task; | |
6b5f5900 | 887 | rpc_wake_up_queued_task(task->tk_waitqueue, task); |
d9b6cd94 TM |
888 | } |
889 | EXPORT_SYMBOL_GPL(rpc_exit); | |
d05fdb0c | 890 | |
bbd5a1f9 TM |
891 | void rpc_release_calldata(const struct rpc_call_ops *ops, void *calldata) |
892 | { | |
a86dc496 | 893 | if (ops->rpc_release != NULL) |
bbd5a1f9 | 894 | ops->rpc_release(calldata); |
bbd5a1f9 TM |
895 | } |
896 | ||
8db55a03 N |
897 | static bool xprt_needs_memalloc(struct rpc_xprt *xprt, struct rpc_task *tk) |
898 | { | |
899 | if (!xprt) | |
900 | return false; | |
901 | if (!atomic_read(&xprt->swapper)) | |
902 | return false; | |
903 | return test_bit(XPRT_LOCKED, &xprt->state) && xprt->snd_task == tk; | |
904 | } | |
905 | ||
1da177e4 LT |
906 | /* |
907 | * This is the RPC `scheduler' (or rather, the finite state machine). | |
908 | */ | |
2efef837 | 909 | static void __rpc_execute(struct rpc_task *task) |
1da177e4 | 910 | { |
eb9b55ab TM |
911 | struct rpc_wait_queue *queue; |
912 | int task_is_async = RPC_IS_ASYNC(task); | |
913 | int status = 0; | |
8db55a03 | 914 | unsigned long pflags = current->flags; |
1da177e4 | 915 | |
2bd4eef8 WAA |
916 | WARN_ON_ONCE(RPC_IS_QUEUED(task)); |
917 | if (RPC_IS_QUEUED(task)) | |
918 | return; | |
1da177e4 | 919 | |
d05fdb0c | 920 | for (;;) { |
b55c5989 | 921 | void (*do_action)(struct rpc_task *); |
1da177e4 LT |
922 | |
923 | /* | |
21ead9ff CL |
924 | * Perform the next FSM step or a pending callback. |
925 | * | |
926 | * tk_action may be NULL if the task has been killed. | |
1da177e4 | 927 | */ |
21ead9ff | 928 | do_action = task->tk_action; |
39494194 | 929 | /* Tasks with an RPC error status should exit */ |
d180891f | 930 | if (do_action && do_action != rpc_exit_task && |
39494194 TM |
931 | (status = READ_ONCE(task->tk_rpc_status)) != 0) { |
932 | task->tk_status = status; | |
d180891f | 933 | do_action = rpc_exit_task; |
39494194 TM |
934 | } |
935 | /* Callbacks override all actions */ | |
21ead9ff CL |
936 | if (task->tk_callback) { |
937 | do_action = task->tk_callback; | |
938 | task->tk_callback = NULL; | |
1da177e4 | 939 | } |
21ead9ff CL |
940 | if (!do_action) |
941 | break; | |
8db55a03 N |
942 | if (RPC_IS_SWAPPER(task) || |
943 | xprt_needs_memalloc(task->tk_xprt, task)) | |
944 | current->flags |= PF_MEMALLOC; | |
945 | ||
e671edb9 | 946 | trace_rpc_task_run_action(task, do_action); |
b55c5989 | 947 | do_action(task); |
1da177e4 LT |
948 | |
949 | /* | |
950 | * Lockless check for whether task is sleeping or not. | |
951 | */ | |
47dd8796 TM |
952 | if (!RPC_IS_QUEUED(task)) { |
953 | cond_resched(); | |
1da177e4 | 954 | continue; |
47dd8796 | 955 | } |
ae67bd38 | 956 | |
eb9b55ab TM |
957 | /* |
958 | * The queue->lock protects against races with | |
959 | * rpc_make_runnable(). | |
960 | * | |
961 | * Note that once we clear RPC_TASK_RUNNING on an asynchronous | |
962 | * rpc_task, rpc_make_runnable() can assign it to a | |
963 | * different workqueue. We therefore cannot assume that the | |
964 | * rpc_task pointer may still be dereferenced. | |
965 | */ | |
966 | queue = task->tk_waitqueue; | |
c049f8ea | 967 | spin_lock(&queue->lock); |
eb9b55ab | 968 | if (!RPC_IS_QUEUED(task)) { |
c049f8ea | 969 | spin_unlock(&queue->lock); |
1da177e4 LT |
970 | continue; |
971 | } | |
39494194 TM |
972 | /* Wake up any task that has an exit status */ |
973 | if (READ_ONCE(task->tk_rpc_status) != 0) { | |
974 | rpc_wake_up_task_queue_locked(queue, task); | |
975 | spin_unlock(&queue->lock); | |
976 | continue; | |
977 | } | |
eb9b55ab | 978 | rpc_clear_running(task); |
c049f8ea | 979 | spin_unlock(&queue->lock); |
eb9b55ab | 980 | if (task_is_async) |
8db55a03 | 981 | goto out; |
1da177e4 LT |
982 | |
983 | /* sync task: sleep here */ | |
1466c221 | 984 | trace_rpc_task_sync_sleep(task, task->tk_action); |
96651ab3 | 985 | status = out_of_line_wait_on_bit(&task->tk_runstate, |
150030b7 | 986 | RPC_TASK_QUEUED, rpc_wait_bit_killable, |
f5d39b02 | 987 | TASK_KILLABLE|TASK_FREEZABLE); |
ae67bd38 | 988 | if (status < 0) { |
1da177e4 LT |
989 | /* |
990 | * When a sync task receives a signal, it exits with | |
991 | * -ERESTARTSYS. In order to catch any callbacks that | |
992 | * clean up after sleeping on some queue, we don't | |
993 | * break the loop here, but go around once more. | |
994 | */ | |
39494194 | 995 | rpc_signal_task(task); |
1da177e4 | 996 | } |
1466c221 | 997 | trace_rpc_task_sync_wake(task, task->tk_action); |
1da177e4 LT |
998 | } |
999 | ||
1da177e4 LT |
1000 | /* Release all resources associated with the task */ |
1001 | rpc_release_task(task); | |
8db55a03 N |
1002 | out: |
1003 | current_restore_flags(pflags, PF_MEMALLOC); | |
1da177e4 LT |
1004 | } |
1005 | ||
1006 | /* | |
1007 | * User-visible entry point to the scheduler. | |
1008 | * | |
1009 | * This may be called recursively if e.g. an async NFS task updates | |
1010 | * the attributes and finds that dirty pages must be flushed. | |
1011 | * NOTE: Upon exit of this function the task is guaranteed to be | |
1012 | * released. In particular note that tk_release() will have | |
1013 | * been called, so your task memory may have been freed. | |
1014 | */ | |
2efef837 | 1015 | void rpc_execute(struct rpc_task *task) |
1da177e4 | 1016 | { |
a76580fb TM |
1017 | bool is_async = RPC_IS_ASYNC(task); |
1018 | ||
44c28873 | 1019 | rpc_set_active(task); |
f1dc237c | 1020 | rpc_make_runnable(rpciod_workqueue, task); |
f0940f4b BC |
1021 | if (!is_async) { |
1022 | unsigned int pflags = memalloc_nofs_save(); | |
d6a1ed08 | 1023 | __rpc_execute(task); |
f0940f4b BC |
1024 | memalloc_nofs_restore(pflags); |
1025 | } | |
1da177e4 LT |
1026 | } |
1027 | ||
65f27f38 | 1028 | static void rpc_async_schedule(struct work_struct *work) |
1da177e4 | 1029 | { |
a1231fda TM |
1030 | unsigned int pflags = memalloc_nofs_save(); |
1031 | ||
65f27f38 | 1032 | __rpc_execute(container_of(work, struct rpc_task, u.tk_work)); |
a1231fda | 1033 | memalloc_nofs_restore(pflags); |
1da177e4 LT |
1034 | } |
1035 | ||
02107148 | 1036 | /** |
5fe6eaa1 CL |
1037 | * rpc_malloc - allocate RPC buffer resources |
1038 | * @task: RPC task | |
1039 | * | |
1040 | * A single memory region is allocated, which is split between the | |
1041 | * RPC call and RPC reply that this task is being used for. When | |
1042 | * this RPC is retired, the memory is released by calling rpc_free. | |
1da177e4 | 1043 | * |
c5a4dd8b | 1044 | * To prevent rpciod from hanging, this allocator never sleeps, |
5fe6eaa1 CL |
1045 | * returning -ENOMEM and suppressing warning if the request cannot |
1046 | * be serviced immediately. The caller can arrange to sleep in a | |
1047 | * way that is safe for rpciod. | |
c5a4dd8b CL |
1048 | * |
1049 | * Most requests are 'small' (under 2KiB) and can be serviced from a | |
1050 | * mempool, ensuring that NFS reads and writes can always proceed, | |
1051 | * and that there is good locality of reference for these buffers. | |
1da177e4 | 1052 | */ |
5fe6eaa1 | 1053 | int rpc_malloc(struct rpc_task *task) |
1da177e4 | 1054 | { |
5fe6eaa1 CL |
1055 | struct rpc_rqst *rqst = task->tk_rqstp; |
1056 | size_t size = rqst->rq_callsize + rqst->rq_rcvsize; | |
aa3d1fae | 1057 | struct rpc_buffer *buf; |
33e5c765 | 1058 | gfp_t gfp = rpc_task_gfp_mask(); |
1da177e4 | 1059 | |
aa3d1fae | 1060 | size += sizeof(struct rpc_buffer); |
33e5c765 TM |
1061 | if (size <= RPC_BUFFER_MAXSIZE) { |
1062 | buf = kmem_cache_alloc(rpc_buffer_slabp, gfp); | |
1063 | /* Reach for the mempool if dynamic allocation fails */ | |
1064 | if (!buf && RPC_IS_ASYNC(task)) | |
1065 | buf = mempool_alloc(rpc_buffer_mempool, GFP_NOWAIT); | |
1066 | } else | |
c5a4dd8b | 1067 | buf = kmalloc(size, gfp); |
ddce40df PZ |
1068 | |
1069 | if (!buf) | |
5fe6eaa1 | 1070 | return -ENOMEM; |
ddce40df | 1071 | |
aa3d1fae | 1072 | buf->len = size; |
5fe6eaa1 | 1073 | rqst->rq_buffer = buf->data; |
68778945 | 1074 | rqst->rq_rbuffer = (char *)rqst->rq_buffer + rqst->rq_callsize; |
5fe6eaa1 | 1075 | return 0; |
1da177e4 | 1076 | } |
12444809 | 1077 | EXPORT_SYMBOL_GPL(rpc_malloc); |
1da177e4 | 1078 | |
02107148 | 1079 | /** |
3435c74a CL |
1080 | * rpc_free - free RPC buffer resources allocated via rpc_malloc |
1081 | * @task: RPC task | |
02107148 CL |
1082 | * |
1083 | */ | |
3435c74a | 1084 | void rpc_free(struct rpc_task *task) |
1da177e4 | 1085 | { |
3435c74a | 1086 | void *buffer = task->tk_rqstp->rq_buffer; |
aa3d1fae CL |
1087 | size_t size; |
1088 | struct rpc_buffer *buf; | |
02107148 | 1089 | |
aa3d1fae CL |
1090 | buf = container_of(buffer, struct rpc_buffer, data); |
1091 | size = buf->len; | |
c5a4dd8b | 1092 | |
c5a4dd8b CL |
1093 | if (size <= RPC_BUFFER_MAXSIZE) |
1094 | mempool_free(buf, rpc_buffer_mempool); | |
1095 | else | |
1096 | kfree(buf); | |
1da177e4 | 1097 | } |
12444809 | 1098 | EXPORT_SYMBOL_GPL(rpc_free); |
1da177e4 LT |
1099 | |
1100 | /* | |
1101 | * Creation and deletion of RPC task structures | |
1102 | */ | |
47fe0648 | 1103 | static void rpc_init_task(struct rpc_task *task, const struct rpc_task_setup *task_setup_data) |
1da177e4 LT |
1104 | { |
1105 | memset(task, 0, sizeof(*task)); | |
44c28873 | 1106 | atomic_set(&task->tk_count, 1); |
84115e1c TM |
1107 | task->tk_flags = task_setup_data->flags; |
1108 | task->tk_ops = task_setup_data->callback_ops; | |
1109 | task->tk_calldata = task_setup_data->callback_data; | |
6529eba0 | 1110 | INIT_LIST_HEAD(&task->tk_task); |
1da177e4 | 1111 | |
3ff7576d TM |
1112 | task->tk_priority = task_setup_data->priority - RPC_PRIORITY_LOW; |
1113 | task->tk_owner = current->tgid; | |
1da177e4 LT |
1114 | |
1115 | /* Initialize workqueue for async tasks */ | |
32bfb5c0 | 1116 | task->tk_workqueue = task_setup_data->workqueue; |
1da177e4 | 1117 | |
a101b043 TM |
1118 | task->tk_xprt = rpc_task_get_xprt(task_setup_data->rpc_client, |
1119 | xprt_get(task_setup_data->rpc_xprt)); | |
9d61498d | 1120 | |
1de7eea9 N |
1121 | task->tk_op_cred = get_rpccred(task_setup_data->rpc_op_cred); |
1122 | ||
84115e1c TM |
1123 | if (task->tk_ops->rpc_call_prepare != NULL) |
1124 | task->tk_action = rpc_prepare_task; | |
963d8fe5 | 1125 | |
7fdcf13b | 1126 | rpc_init_task_statistics(task); |
1da177e4 LT |
1127 | } |
1128 | ||
910ad386 | 1129 | static struct rpc_task *rpc_alloc_task(void) |
1da177e4 | 1130 | { |
910ad386 TM |
1131 | struct rpc_task *task; |
1132 | ||
1133 | task = kmem_cache_alloc(rpc_task_slabp, rpc_task_gfp_mask()); | |
1134 | if (task) | |
1135 | return task; | |
1136 | return mempool_alloc(rpc_task_mempool, GFP_NOWAIT); | |
1da177e4 LT |
1137 | } |
1138 | ||
1da177e4 | 1139 | /* |
90c5755f | 1140 | * Create a new task for the specified client. |
1da177e4 | 1141 | */ |
84115e1c | 1142 | struct rpc_task *rpc_new_task(const struct rpc_task_setup *setup_data) |
1da177e4 | 1143 | { |
e8f5d77c TM |
1144 | struct rpc_task *task = setup_data->task; |
1145 | unsigned short flags = 0; | |
1146 | ||
1147 | if (task == NULL) { | |
1148 | task = rpc_alloc_task(); | |
25cf32ad TM |
1149 | if (task == NULL) { |
1150 | rpc_release_calldata(setup_data->callback_ops, | |
1151 | setup_data->callback_data); | |
1152 | return ERR_PTR(-ENOMEM); | |
1153 | } | |
e8f5d77c TM |
1154 | flags = RPC_TASK_DYNAMIC; |
1155 | } | |
1da177e4 | 1156 | |
84115e1c | 1157 | rpc_init_task(task, setup_data); |
e8f5d77c | 1158 | task->tk_flags |= flags; |
1da177e4 | 1159 | return task; |
1da177e4 LT |
1160 | } |
1161 | ||
c6567ed1 TM |
1162 | /* |
1163 | * rpc_free_task - release rpc task and perform cleanups | |
1164 | * | |
1165 | * Note that we free up the rpc_task _after_ rpc_release_calldata() | |
1166 | * in order to work around a workqueue dependency issue. | |
1167 | * | |
1168 | * Tejun Heo states: | |
1169 | * "Workqueue currently considers two work items to be the same if they're | |
1170 | * on the same address and won't execute them concurrently - ie. it | |
1171 | * makes a work item which is queued again while being executed wait | |
1172 | * for the previous execution to complete. | |
1173 | * | |
1174 | * If a work function frees the work item, and then waits for an event | |
1175 | * which should be performed by another work item and *that* work item | |
1176 | * recycles the freed work item, it can create a false dependency loop. | |
1177 | * There really is no reliable way to detect this short of verifying | |
1178 | * every memory free." | |
1179 | * | |
1180 | */ | |
32bfb5c0 | 1181 | static void rpc_free_task(struct rpc_task *task) |
1da177e4 | 1182 | { |
c6567ed1 TM |
1183 | unsigned short tk_flags = task->tk_flags; |
1184 | ||
1de7eea9 | 1185 | put_rpccred(task->tk_op_cred); |
c6567ed1 | 1186 | rpc_release_calldata(task->tk_ops, task->tk_calldata); |
1da177e4 | 1187 | |
1466c221 | 1188 | if (tk_flags & RPC_TASK_DYNAMIC) |
5e4424af | 1189 | mempool_free(task, rpc_task_mempool); |
32bfb5c0 TM |
1190 | } |
1191 | ||
1192 | static void rpc_async_release(struct work_struct *work) | |
1193 | { | |
a1231fda TM |
1194 | unsigned int pflags = memalloc_nofs_save(); |
1195 | ||
32bfb5c0 | 1196 | rpc_free_task(container_of(work, struct rpc_task, u.tk_work)); |
a1231fda | 1197 | memalloc_nofs_restore(pflags); |
32bfb5c0 TM |
1198 | } |
1199 | ||
bf294b41 | 1200 | static void rpc_release_resources_task(struct rpc_task *task) |
32bfb5c0 | 1201 | { |
87ed5003 | 1202 | xprt_release(task); |
a271c5a0 | 1203 | if (task->tk_msg.rpc_cred) { |
7eac5264 TM |
1204 | if (!(task->tk_flags & RPC_TASK_CRED_NOREF)) |
1205 | put_cred(task->tk_msg.rpc_cred); | |
a271c5a0 OH |
1206 | task->tk_msg.rpc_cred = NULL; |
1207 | } | |
58f9612c | 1208 | rpc_task_release_client(task); |
bf294b41 TM |
1209 | } |
1210 | ||
1211 | static void rpc_final_put_task(struct rpc_task *task, | |
1212 | struct workqueue_struct *q) | |
1213 | { | |
1214 | if (q != NULL) { | |
32bfb5c0 | 1215 | INIT_WORK(&task->u.tk_work, rpc_async_release); |
bf294b41 | 1216 | queue_work(q, &task->u.tk_work); |
32bfb5c0 TM |
1217 | } else |
1218 | rpc_free_task(task); | |
e6b3c4db | 1219 | } |
bf294b41 TM |
1220 | |
1221 | static void rpc_do_put_task(struct rpc_task *task, struct workqueue_struct *q) | |
1222 | { | |
1223 | if (atomic_dec_and_test(&task->tk_count)) { | |
1224 | rpc_release_resources_task(task); | |
1225 | rpc_final_put_task(task, q); | |
1226 | } | |
1227 | } | |
1228 | ||
1229 | void rpc_put_task(struct rpc_task *task) | |
1230 | { | |
1231 | rpc_do_put_task(task, NULL); | |
1232 | } | |
e8914c65 | 1233 | EXPORT_SYMBOL_GPL(rpc_put_task); |
e6b3c4db | 1234 | |
bf294b41 TM |
1235 | void rpc_put_task_async(struct rpc_task *task) |
1236 | { | |
1237 | rpc_do_put_task(task, task->tk_workqueue); | |
1238 | } | |
1239 | EXPORT_SYMBOL_GPL(rpc_put_task_async); | |
1240 | ||
bde8f00c | 1241 | static void rpc_release_task(struct rpc_task *task) |
e6b3c4db | 1242 | { |
0a0c2a57 | 1243 | WARN_ON_ONCE(RPC_IS_QUEUED(task)); |
1da177e4 | 1244 | |
bf294b41 | 1245 | rpc_release_resources_task(task); |
e6b3c4db | 1246 | |
bf294b41 TM |
1247 | /* |
1248 | * Note: at this point we have been removed from rpc_clnt->cl_tasks, | |
1249 | * so it should be safe to use task->tk_count as a test for whether | |
1250 | * or not any other processes still hold references to our rpc_task. | |
1251 | */ | |
1252 | if (atomic_read(&task->tk_count) != 1 + !RPC_IS_ASYNC(task)) { | |
1253 | /* Wake up anyone who may be waiting for task completion */ | |
1254 | if (!rpc_complete_task(task)) | |
1255 | return; | |
1256 | } else { | |
1257 | if (!atomic_dec_and_test(&task->tk_count)) | |
1258 | return; | |
1259 | } | |
1260 | rpc_final_put_task(task, task->tk_workqueue); | |
1da177e4 LT |
1261 | } |
1262 | ||
b247bbf1 TM |
1263 | int rpciod_up(void) |
1264 | { | |
1265 | return try_module_get(THIS_MODULE) ? 0 : -EINVAL; | |
1266 | } | |
1267 | ||
1268 | void rpciod_down(void) | |
1269 | { | |
1270 | module_put(THIS_MODULE); | |
1271 | } | |
1272 | ||
1da177e4 | 1273 | /* |
b247bbf1 | 1274 | * Start up the rpciod workqueue. |
1da177e4 | 1275 | */ |
b247bbf1 | 1276 | static int rpciod_start(void) |
1da177e4 LT |
1277 | { |
1278 | struct workqueue_struct *wq; | |
ab418d70 | 1279 | |
1da177e4 LT |
1280 | /* |
1281 | * Create the rpciod thread and wait for it to start. | |
1282 | */ | |
f515f86b | 1283 | wq = alloc_workqueue("rpciod", WQ_MEM_RECLAIM | WQ_UNBOUND, 0); |
40a5f1b1 TM |
1284 | if (!wq) |
1285 | goto out_failed; | |
1da177e4 | 1286 | rpciod_workqueue = wq; |
6dbcbe3f | 1287 | wq = alloc_workqueue("xprtiod", WQ_UNBOUND | WQ_MEM_RECLAIM, 0); |
40a5f1b1 TM |
1288 | if (!wq) |
1289 | goto free_rpciod; | |
1290 | xprtiod_workqueue = wq; | |
1291 | return 1; | |
1292 | free_rpciod: | |
1293 | wq = rpciod_workqueue; | |
1294 | rpciod_workqueue = NULL; | |
1295 | destroy_workqueue(wq); | |
1296 | out_failed: | |
1297 | return 0; | |
1da177e4 LT |
1298 | } |
1299 | ||
b247bbf1 | 1300 | static void rpciod_stop(void) |
1da177e4 | 1301 | { |
b247bbf1 | 1302 | struct workqueue_struct *wq = NULL; |
ab418d70 | 1303 | |
b247bbf1 TM |
1304 | if (rpciod_workqueue == NULL) |
1305 | return; | |
1da177e4 | 1306 | |
b247bbf1 TM |
1307 | wq = rpciod_workqueue; |
1308 | rpciod_workqueue = NULL; | |
1309 | destroy_workqueue(wq); | |
40a5f1b1 TM |
1310 | wq = xprtiod_workqueue; |
1311 | xprtiod_workqueue = NULL; | |
1312 | destroy_workqueue(wq); | |
1da177e4 LT |
1313 | } |
1314 | ||
1da177e4 LT |
1315 | void |
1316 | rpc_destroy_mempool(void) | |
1317 | { | |
b247bbf1 | 1318 | rpciod_stop(); |
17a9618e JL |
1319 | mempool_destroy(rpc_buffer_mempool); |
1320 | mempool_destroy(rpc_task_mempool); | |
1321 | kmem_cache_destroy(rpc_task_slabp); | |
1322 | kmem_cache_destroy(rpc_buffer_slabp); | |
f6a1cc89 | 1323 | rpc_destroy_wait_queue(&delay_queue); |
1da177e4 LT |
1324 | } |
1325 | ||
1326 | int | |
1327 | rpc_init_mempool(void) | |
1328 | { | |
f6a1cc89 TM |
1329 | /* |
1330 | * The following is not strictly a mempool initialisation, | |
1331 | * but there is no harm in doing it here | |
1332 | */ | |
1333 | rpc_init_wait_queue(&delay_queue, "delayq"); | |
1334 | if (!rpciod_start()) | |
1335 | goto err_nomem; | |
1336 | ||
1da177e4 LT |
1337 | rpc_task_slabp = kmem_cache_create("rpc_tasks", |
1338 | sizeof(struct rpc_task), | |
1339 | 0, SLAB_HWCACHE_ALIGN, | |
20c2df83 | 1340 | NULL); |
1da177e4 LT |
1341 | if (!rpc_task_slabp) |
1342 | goto err_nomem; | |
1343 | rpc_buffer_slabp = kmem_cache_create("rpc_buffers", | |
1344 | RPC_BUFFER_MAXSIZE, | |
1345 | 0, SLAB_HWCACHE_ALIGN, | |
20c2df83 | 1346 | NULL); |
1da177e4 LT |
1347 | if (!rpc_buffer_slabp) |
1348 | goto err_nomem; | |
93d2341c MD |
1349 | rpc_task_mempool = mempool_create_slab_pool(RPC_TASK_POOLSIZE, |
1350 | rpc_task_slabp); | |
1da177e4 LT |
1351 | if (!rpc_task_mempool) |
1352 | goto err_nomem; | |
93d2341c MD |
1353 | rpc_buffer_mempool = mempool_create_slab_pool(RPC_BUFFER_POOLSIZE, |
1354 | rpc_buffer_slabp); | |
1da177e4 LT |
1355 | if (!rpc_buffer_mempool) |
1356 | goto err_nomem; | |
1357 | return 0; | |
1358 | err_nomem: | |
1359 | rpc_destroy_mempool(); | |
1360 | return -ENOMEM; | |
1361 | } |