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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/net/sunrpc/sched.c | |
3 | * | |
4 | * Scheduling for synchronous and asynchronous RPC requests. | |
5 | * | |
6 | * Copyright (C) 1996 Olaf Kirch, <okir@monad.swb.de> | |
7 | * | |
8 | * TCP NFS related read + write fixes | |
9 | * (C) 1999 Dave Airlie, University of Limerick, Ireland <airlied@linux.ie> | |
10 | */ | |
11 | ||
12 | #include <linux/module.h> | |
13 | ||
14 | #include <linux/sched.h> | |
15 | #include <linux/interrupt.h> | |
16 | #include <linux/slab.h> | |
17 | #include <linux/mempool.h> | |
18 | #include <linux/smp.h> | |
19 | #include <linux/smp_lock.h> | |
20 | #include <linux/spinlock.h> | |
4a3e2f71 | 21 | #include <linux/mutex.h> |
1da177e4 LT |
22 | |
23 | #include <linux/sunrpc/clnt.h> | |
1da177e4 LT |
24 | |
25 | #ifdef RPC_DEBUG | |
26 | #define RPCDBG_FACILITY RPCDBG_SCHED | |
27 | #define RPC_TASK_MAGIC_ID 0xf00baa | |
28 | static int rpc_task_id; | |
29 | #endif | |
30 | ||
31 | /* | |
32 | * RPC slabs and memory pools | |
33 | */ | |
34 | #define RPC_BUFFER_MAXSIZE (2048) | |
35 | #define RPC_BUFFER_POOLSIZE (8) | |
36 | #define RPC_TASK_POOLSIZE (8) | |
ba89966c ED |
37 | static kmem_cache_t *rpc_task_slabp __read_mostly; |
38 | static kmem_cache_t *rpc_buffer_slabp __read_mostly; | |
39 | static mempool_t *rpc_task_mempool __read_mostly; | |
40 | static mempool_t *rpc_buffer_mempool __read_mostly; | |
1da177e4 LT |
41 | |
42 | static void __rpc_default_timer(struct rpc_task *task); | |
43 | static void rpciod_killall(void); | |
1da177e4 LT |
44 | static void rpc_async_schedule(void *); |
45 | ||
1da177e4 LT |
46 | /* |
47 | * RPC tasks sit here while waiting for conditions to improve. | |
48 | */ | |
49 | static RPC_WAITQ(delay_queue, "delayq"); | |
50 | ||
51 | /* | |
52 | * All RPC tasks are linked into this list | |
53 | */ | |
54 | static LIST_HEAD(all_tasks); | |
55 | ||
56 | /* | |
57 | * rpciod-related stuff | |
58 | */ | |
4a3e2f71 | 59 | static DEFINE_MUTEX(rpciod_mutex); |
1da177e4 | 60 | static unsigned int rpciod_users; |
24c5d9d7 | 61 | struct workqueue_struct *rpciod_workqueue; |
1da177e4 LT |
62 | |
63 | /* | |
64 | * Spinlock for other critical sections of code. | |
65 | */ | |
66 | static DEFINE_SPINLOCK(rpc_sched_lock); | |
67 | ||
68 | /* | |
69 | * Disable the timer for a given RPC task. Should be called with | |
70 | * queue->lock and bh_disabled in order to avoid races within | |
71 | * rpc_run_timer(). | |
72 | */ | |
73 | static inline void | |
74 | __rpc_disable_timer(struct rpc_task *task) | |
75 | { | |
76 | dprintk("RPC: %4d disabling timer\n", task->tk_pid); | |
77 | task->tk_timeout_fn = NULL; | |
78 | task->tk_timeout = 0; | |
79 | } | |
80 | ||
81 | /* | |
82 | * Run a timeout function. | |
83 | * We use the callback in order to allow __rpc_wake_up_task() | |
84 | * and friends to disable the timer synchronously on SMP systems | |
85 | * without calling del_timer_sync(). The latter could cause a | |
86 | * deadlock if called while we're holding spinlocks... | |
87 | */ | |
88 | static void rpc_run_timer(struct rpc_task *task) | |
89 | { | |
90 | void (*callback)(struct rpc_task *); | |
91 | ||
92 | callback = task->tk_timeout_fn; | |
93 | task->tk_timeout_fn = NULL; | |
94 | if (callback && RPC_IS_QUEUED(task)) { | |
95 | dprintk("RPC: %4d running timer\n", task->tk_pid); | |
96 | callback(task); | |
97 | } | |
98 | smp_mb__before_clear_bit(); | |
99 | clear_bit(RPC_TASK_HAS_TIMER, &task->tk_runstate); | |
100 | smp_mb__after_clear_bit(); | |
101 | } | |
102 | ||
103 | /* | |
104 | * Set up a timer for the current task. | |
105 | */ | |
106 | static inline void | |
107 | __rpc_add_timer(struct rpc_task *task, rpc_action timer) | |
108 | { | |
109 | if (!task->tk_timeout) | |
110 | return; | |
111 | ||
112 | dprintk("RPC: %4d setting alarm for %lu ms\n", | |
113 | task->tk_pid, task->tk_timeout * 1000 / HZ); | |
114 | ||
115 | if (timer) | |
116 | task->tk_timeout_fn = timer; | |
117 | else | |
118 | task->tk_timeout_fn = __rpc_default_timer; | |
119 | set_bit(RPC_TASK_HAS_TIMER, &task->tk_runstate); | |
120 | mod_timer(&task->tk_timer, jiffies + task->tk_timeout); | |
121 | } | |
122 | ||
123 | /* | |
124 | * Delete any timer for the current task. Because we use del_timer_sync(), | |
125 | * this function should never be called while holding queue->lock. | |
126 | */ | |
127 | static void | |
128 | rpc_delete_timer(struct rpc_task *task) | |
129 | { | |
130 | if (RPC_IS_QUEUED(task)) | |
131 | return; | |
132 | if (test_and_clear_bit(RPC_TASK_HAS_TIMER, &task->tk_runstate)) { | |
133 | del_singleshot_timer_sync(&task->tk_timer); | |
134 | dprintk("RPC: %4d deleting timer\n", task->tk_pid); | |
135 | } | |
136 | } | |
137 | ||
138 | /* | |
139 | * Add new request to a priority queue. | |
140 | */ | |
141 | static void __rpc_add_wait_queue_priority(struct rpc_wait_queue *queue, struct rpc_task *task) | |
142 | { | |
143 | struct list_head *q; | |
144 | struct rpc_task *t; | |
145 | ||
146 | INIT_LIST_HEAD(&task->u.tk_wait.links); | |
147 | q = &queue->tasks[task->tk_priority]; | |
148 | if (unlikely(task->tk_priority > queue->maxpriority)) | |
149 | q = &queue->tasks[queue->maxpriority]; | |
150 | list_for_each_entry(t, q, u.tk_wait.list) { | |
151 | if (t->tk_cookie == task->tk_cookie) { | |
152 | list_add_tail(&task->u.tk_wait.list, &t->u.tk_wait.links); | |
153 | return; | |
154 | } | |
155 | } | |
156 | list_add_tail(&task->u.tk_wait.list, q); | |
157 | } | |
158 | ||
159 | /* | |
160 | * Add new request to wait queue. | |
161 | * | |
162 | * Swapper tasks always get inserted at the head of the queue. | |
163 | * This should avoid many nasty memory deadlocks and hopefully | |
164 | * improve overall performance. | |
165 | * Everyone else gets appended to the queue to ensure proper FIFO behavior. | |
166 | */ | |
167 | static void __rpc_add_wait_queue(struct rpc_wait_queue *queue, struct rpc_task *task) | |
168 | { | |
169 | BUG_ON (RPC_IS_QUEUED(task)); | |
170 | ||
171 | if (RPC_IS_PRIORITY(queue)) | |
172 | __rpc_add_wait_queue_priority(queue, task); | |
173 | else if (RPC_IS_SWAPPER(task)) | |
174 | list_add(&task->u.tk_wait.list, &queue->tasks[0]); | |
175 | else | |
176 | list_add_tail(&task->u.tk_wait.list, &queue->tasks[0]); | |
177 | task->u.tk_wait.rpc_waitq = queue; | |
e19b63da | 178 | queue->qlen++; |
1da177e4 LT |
179 | rpc_set_queued(task); |
180 | ||
181 | dprintk("RPC: %4d added to queue %p \"%s\"\n", | |
182 | task->tk_pid, queue, rpc_qname(queue)); | |
183 | } | |
184 | ||
185 | /* | |
186 | * Remove request from a priority queue. | |
187 | */ | |
188 | static void __rpc_remove_wait_queue_priority(struct rpc_task *task) | |
189 | { | |
190 | struct rpc_task *t; | |
191 | ||
192 | if (!list_empty(&task->u.tk_wait.links)) { | |
193 | t = list_entry(task->u.tk_wait.links.next, struct rpc_task, u.tk_wait.list); | |
194 | list_move(&t->u.tk_wait.list, &task->u.tk_wait.list); | |
195 | list_splice_init(&task->u.tk_wait.links, &t->u.tk_wait.links); | |
196 | } | |
197 | list_del(&task->u.tk_wait.list); | |
198 | } | |
199 | ||
200 | /* | |
201 | * Remove request from queue. | |
202 | * Note: must be called with spin lock held. | |
203 | */ | |
204 | static void __rpc_remove_wait_queue(struct rpc_task *task) | |
205 | { | |
206 | struct rpc_wait_queue *queue; | |
207 | queue = task->u.tk_wait.rpc_waitq; | |
208 | ||
209 | if (RPC_IS_PRIORITY(queue)) | |
210 | __rpc_remove_wait_queue_priority(task); | |
211 | else | |
212 | list_del(&task->u.tk_wait.list); | |
e19b63da | 213 | queue->qlen--; |
1da177e4 LT |
214 | dprintk("RPC: %4d removed from queue %p \"%s\"\n", |
215 | task->tk_pid, queue, rpc_qname(queue)); | |
216 | } | |
217 | ||
218 | static inline void rpc_set_waitqueue_priority(struct rpc_wait_queue *queue, int priority) | |
219 | { | |
220 | queue->priority = priority; | |
221 | queue->count = 1 << (priority * 2); | |
222 | } | |
223 | ||
224 | static inline void rpc_set_waitqueue_cookie(struct rpc_wait_queue *queue, unsigned long cookie) | |
225 | { | |
226 | queue->cookie = cookie; | |
227 | queue->nr = RPC_BATCH_COUNT; | |
228 | } | |
229 | ||
230 | static inline void rpc_reset_waitqueue_priority(struct rpc_wait_queue *queue) | |
231 | { | |
232 | rpc_set_waitqueue_priority(queue, queue->maxpriority); | |
233 | rpc_set_waitqueue_cookie(queue, 0); | |
234 | } | |
235 | ||
236 | static void __rpc_init_priority_wait_queue(struct rpc_wait_queue *queue, const char *qname, int maxprio) | |
237 | { | |
238 | int i; | |
239 | ||
240 | spin_lock_init(&queue->lock); | |
241 | for (i = 0; i < ARRAY_SIZE(queue->tasks); i++) | |
242 | INIT_LIST_HEAD(&queue->tasks[i]); | |
243 | queue->maxpriority = maxprio; | |
244 | rpc_reset_waitqueue_priority(queue); | |
245 | #ifdef RPC_DEBUG | |
246 | queue->name = qname; | |
247 | #endif | |
248 | } | |
249 | ||
250 | void rpc_init_priority_wait_queue(struct rpc_wait_queue *queue, const char *qname) | |
251 | { | |
252 | __rpc_init_priority_wait_queue(queue, qname, RPC_PRIORITY_HIGH); | |
253 | } | |
254 | ||
255 | void rpc_init_wait_queue(struct rpc_wait_queue *queue, const char *qname) | |
256 | { | |
257 | __rpc_init_priority_wait_queue(queue, qname, 0); | |
258 | } | |
259 | EXPORT_SYMBOL(rpc_init_wait_queue); | |
260 | ||
44c28873 TM |
261 | static int rpc_wait_bit_interruptible(void *word) |
262 | { | |
263 | if (signal_pending(current)) | |
264 | return -ERESTARTSYS; | |
265 | schedule(); | |
266 | return 0; | |
267 | } | |
268 | ||
269 | /* | |
270 | * Mark an RPC call as having completed by clearing the 'active' bit | |
271 | */ | |
272 | static inline void rpc_mark_complete_task(struct rpc_task *task) | |
273 | { | |
274 | rpc_clear_active(task); | |
275 | wake_up_bit(&task->tk_runstate, RPC_TASK_ACTIVE); | |
276 | } | |
277 | ||
278 | /* | |
279 | * Allow callers to wait for completion of an RPC call | |
280 | */ | |
281 | int __rpc_wait_for_completion_task(struct rpc_task *task, int (*action)(void *)) | |
282 | { | |
283 | if (action == NULL) | |
284 | action = rpc_wait_bit_interruptible; | |
285 | return wait_on_bit(&task->tk_runstate, RPC_TASK_ACTIVE, | |
286 | action, TASK_INTERRUPTIBLE); | |
287 | } | |
288 | EXPORT_SYMBOL(__rpc_wait_for_completion_task); | |
289 | ||
1da177e4 LT |
290 | /* |
291 | * Make an RPC task runnable. | |
292 | * | |
293 | * Note: If the task is ASYNC, this must be called with | |
294 | * the spinlock held to protect the wait queue operation. | |
295 | */ | |
296 | static void rpc_make_runnable(struct rpc_task *task) | |
297 | { | |
1da177e4 | 298 | BUG_ON(task->tk_timeout_fn); |
1da177e4 | 299 | rpc_clear_queued(task); |
cc4dc59e CS |
300 | if (rpc_test_and_set_running(task)) |
301 | return; | |
302 | /* We might have raced */ | |
303 | if (RPC_IS_QUEUED(task)) { | |
304 | rpc_clear_running(task); | |
1da177e4 | 305 | return; |
cc4dc59e | 306 | } |
1da177e4 LT |
307 | if (RPC_IS_ASYNC(task)) { |
308 | int status; | |
309 | ||
310 | INIT_WORK(&task->u.tk_work, rpc_async_schedule, (void *)task); | |
311 | status = queue_work(task->tk_workqueue, &task->u.tk_work); | |
312 | if (status < 0) { | |
313 | printk(KERN_WARNING "RPC: failed to add task to queue: error: %d!\n", status); | |
314 | task->tk_status = status; | |
315 | return; | |
316 | } | |
317 | } else | |
96651ab3 | 318 | wake_up_bit(&task->tk_runstate, RPC_TASK_QUEUED); |
1da177e4 LT |
319 | } |
320 | ||
1da177e4 LT |
321 | /* |
322 | * Prepare for sleeping on a wait queue. | |
323 | * By always appending tasks to the list we ensure FIFO behavior. | |
324 | * NB: An RPC task will only receive interrupt-driven events as long | |
325 | * as it's on a wait queue. | |
326 | */ | |
327 | static void __rpc_sleep_on(struct rpc_wait_queue *q, struct rpc_task *task, | |
328 | rpc_action action, rpc_action timer) | |
329 | { | |
330 | dprintk("RPC: %4d sleep_on(queue \"%s\" time %ld)\n", task->tk_pid, | |
331 | rpc_qname(q), jiffies); | |
332 | ||
333 | if (!RPC_IS_ASYNC(task) && !RPC_IS_ACTIVATED(task)) { | |
334 | printk(KERN_ERR "RPC: Inactive synchronous task put to sleep!\n"); | |
335 | return; | |
336 | } | |
337 | ||
338 | /* Mark the task as being activated if so needed */ | |
44c28873 | 339 | rpc_set_active(task); |
1da177e4 LT |
340 | |
341 | __rpc_add_wait_queue(q, task); | |
342 | ||
343 | BUG_ON(task->tk_callback != NULL); | |
344 | task->tk_callback = action; | |
345 | __rpc_add_timer(task, timer); | |
346 | } | |
347 | ||
348 | void rpc_sleep_on(struct rpc_wait_queue *q, struct rpc_task *task, | |
349 | rpc_action action, rpc_action timer) | |
350 | { | |
351 | /* | |
352 | * Protect the queue operations. | |
353 | */ | |
354 | spin_lock_bh(&q->lock); | |
355 | __rpc_sleep_on(q, task, action, timer); | |
356 | spin_unlock_bh(&q->lock); | |
357 | } | |
358 | ||
359 | /** | |
360 | * __rpc_do_wake_up_task - wake up a single rpc_task | |
361 | * @task: task to be woken up | |
362 | * | |
363 | * Caller must hold queue->lock, and have cleared the task queued flag. | |
364 | */ | |
365 | static void __rpc_do_wake_up_task(struct rpc_task *task) | |
366 | { | |
367 | dprintk("RPC: %4d __rpc_wake_up_task (now %ld)\n", task->tk_pid, jiffies); | |
368 | ||
369 | #ifdef RPC_DEBUG | |
370 | BUG_ON(task->tk_magic != RPC_TASK_MAGIC_ID); | |
371 | #endif | |
372 | /* Has the task been executed yet? If not, we cannot wake it up! */ | |
373 | if (!RPC_IS_ACTIVATED(task)) { | |
374 | printk(KERN_ERR "RPC: Inactive task (%p) being woken up!\n", task); | |
375 | return; | |
376 | } | |
377 | ||
378 | __rpc_disable_timer(task); | |
379 | __rpc_remove_wait_queue(task); | |
380 | ||
381 | rpc_make_runnable(task); | |
382 | ||
383 | dprintk("RPC: __rpc_wake_up_task done\n"); | |
384 | } | |
385 | ||
386 | /* | |
387 | * Wake up the specified task | |
388 | */ | |
389 | static void __rpc_wake_up_task(struct rpc_task *task) | |
390 | { | |
391 | if (rpc_start_wakeup(task)) { | |
392 | if (RPC_IS_QUEUED(task)) | |
393 | __rpc_do_wake_up_task(task); | |
394 | rpc_finish_wakeup(task); | |
395 | } | |
396 | } | |
397 | ||
398 | /* | |
399 | * Default timeout handler if none specified by user | |
400 | */ | |
401 | static void | |
402 | __rpc_default_timer(struct rpc_task *task) | |
403 | { | |
404 | dprintk("RPC: %d timeout (default timer)\n", task->tk_pid); | |
405 | task->tk_status = -ETIMEDOUT; | |
406 | rpc_wake_up_task(task); | |
407 | } | |
408 | ||
409 | /* | |
410 | * Wake up the specified task | |
411 | */ | |
412 | void rpc_wake_up_task(struct rpc_task *task) | |
413 | { | |
414 | if (rpc_start_wakeup(task)) { | |
415 | if (RPC_IS_QUEUED(task)) { | |
416 | struct rpc_wait_queue *queue = task->u.tk_wait.rpc_waitq; | |
417 | ||
418 | spin_lock_bh(&queue->lock); | |
419 | __rpc_do_wake_up_task(task); | |
420 | spin_unlock_bh(&queue->lock); | |
421 | } | |
422 | rpc_finish_wakeup(task); | |
423 | } | |
424 | } | |
425 | ||
426 | /* | |
427 | * Wake up the next task on a priority queue. | |
428 | */ | |
429 | static struct rpc_task * __rpc_wake_up_next_priority(struct rpc_wait_queue *queue) | |
430 | { | |
431 | struct list_head *q; | |
432 | struct rpc_task *task; | |
433 | ||
434 | /* | |
435 | * Service a batch of tasks from a single cookie. | |
436 | */ | |
437 | q = &queue->tasks[queue->priority]; | |
438 | if (!list_empty(q)) { | |
439 | task = list_entry(q->next, struct rpc_task, u.tk_wait.list); | |
440 | if (queue->cookie == task->tk_cookie) { | |
441 | if (--queue->nr) | |
442 | goto out; | |
443 | list_move_tail(&task->u.tk_wait.list, q); | |
444 | } | |
445 | /* | |
446 | * Check if we need to switch queues. | |
447 | */ | |
448 | if (--queue->count) | |
449 | goto new_cookie; | |
450 | } | |
451 | ||
452 | /* | |
453 | * Service the next queue. | |
454 | */ | |
455 | do { | |
456 | if (q == &queue->tasks[0]) | |
457 | q = &queue->tasks[queue->maxpriority]; | |
458 | else | |
459 | q = q - 1; | |
460 | if (!list_empty(q)) { | |
461 | task = list_entry(q->next, struct rpc_task, u.tk_wait.list); | |
462 | goto new_queue; | |
463 | } | |
464 | } while (q != &queue->tasks[queue->priority]); | |
465 | ||
466 | rpc_reset_waitqueue_priority(queue); | |
467 | return NULL; | |
468 | ||
469 | new_queue: | |
470 | rpc_set_waitqueue_priority(queue, (unsigned int)(q - &queue->tasks[0])); | |
471 | new_cookie: | |
472 | rpc_set_waitqueue_cookie(queue, task->tk_cookie); | |
473 | out: | |
474 | __rpc_wake_up_task(task); | |
475 | return task; | |
476 | } | |
477 | ||
478 | /* | |
479 | * Wake up the next task on the wait queue. | |
480 | */ | |
481 | struct rpc_task * rpc_wake_up_next(struct rpc_wait_queue *queue) | |
482 | { | |
483 | struct rpc_task *task = NULL; | |
484 | ||
485 | dprintk("RPC: wake_up_next(%p \"%s\")\n", queue, rpc_qname(queue)); | |
486 | spin_lock_bh(&queue->lock); | |
487 | if (RPC_IS_PRIORITY(queue)) | |
488 | task = __rpc_wake_up_next_priority(queue); | |
489 | else { | |
490 | task_for_first(task, &queue->tasks[0]) | |
491 | __rpc_wake_up_task(task); | |
492 | } | |
493 | spin_unlock_bh(&queue->lock); | |
494 | ||
495 | return task; | |
496 | } | |
497 | ||
498 | /** | |
499 | * rpc_wake_up - wake up all rpc_tasks | |
500 | * @queue: rpc_wait_queue on which the tasks are sleeping | |
501 | * | |
502 | * Grabs queue->lock | |
503 | */ | |
504 | void rpc_wake_up(struct rpc_wait_queue *queue) | |
505 | { | |
e6d83d55 | 506 | struct rpc_task *task, *next; |
1da177e4 | 507 | struct list_head *head; |
e6d83d55 | 508 | |
1da177e4 LT |
509 | spin_lock_bh(&queue->lock); |
510 | head = &queue->tasks[queue->maxpriority]; | |
511 | for (;;) { | |
e6d83d55 | 512 | list_for_each_entry_safe(task, next, head, u.tk_wait.list) |
1da177e4 | 513 | __rpc_wake_up_task(task); |
1da177e4 LT |
514 | if (head == &queue->tasks[0]) |
515 | break; | |
516 | head--; | |
517 | } | |
518 | spin_unlock_bh(&queue->lock); | |
519 | } | |
520 | ||
521 | /** | |
522 | * rpc_wake_up_status - wake up all rpc_tasks and set their status value. | |
523 | * @queue: rpc_wait_queue on which the tasks are sleeping | |
524 | * @status: status value to set | |
525 | * | |
526 | * Grabs queue->lock | |
527 | */ | |
528 | void rpc_wake_up_status(struct rpc_wait_queue *queue, int status) | |
529 | { | |
e6d83d55 | 530 | struct rpc_task *task, *next; |
1da177e4 | 531 | struct list_head *head; |
1da177e4 LT |
532 | |
533 | spin_lock_bh(&queue->lock); | |
534 | head = &queue->tasks[queue->maxpriority]; | |
535 | for (;;) { | |
e6d83d55 | 536 | list_for_each_entry_safe(task, next, head, u.tk_wait.list) { |
1da177e4 LT |
537 | task->tk_status = status; |
538 | __rpc_wake_up_task(task); | |
539 | } | |
540 | if (head == &queue->tasks[0]) | |
541 | break; | |
542 | head--; | |
543 | } | |
544 | spin_unlock_bh(&queue->lock); | |
545 | } | |
546 | ||
8014793b TM |
547 | static void __rpc_atrun(struct rpc_task *task) |
548 | { | |
549 | rpc_wake_up_task(task); | |
550 | } | |
551 | ||
1da177e4 LT |
552 | /* |
553 | * Run a task at a later time | |
554 | */ | |
8014793b | 555 | void rpc_delay(struct rpc_task *task, unsigned long delay) |
1da177e4 LT |
556 | { |
557 | task->tk_timeout = delay; | |
558 | rpc_sleep_on(&delay_queue, task, NULL, __rpc_atrun); | |
559 | } | |
560 | ||
4ce70ada TM |
561 | /* |
562 | * Helper to call task->tk_ops->rpc_call_prepare | |
563 | */ | |
564 | static void rpc_prepare_task(struct rpc_task *task) | |
565 | { | |
566 | task->tk_ops->rpc_call_prepare(task, task->tk_calldata); | |
567 | } | |
568 | ||
d05fdb0c | 569 | /* |
963d8fe5 | 570 | * Helper that calls task->tk_ops->rpc_call_done if it exists |
d05fdb0c | 571 | */ |
abbcf28f | 572 | void rpc_exit_task(struct rpc_task *task) |
d05fdb0c | 573 | { |
abbcf28f | 574 | task->tk_action = NULL; |
963d8fe5 TM |
575 | if (task->tk_ops->rpc_call_done != NULL) { |
576 | task->tk_ops->rpc_call_done(task, task->tk_calldata); | |
d05fdb0c | 577 | if (task->tk_action != NULL) { |
abbcf28f TM |
578 | WARN_ON(RPC_ASSASSINATED(task)); |
579 | /* Always release the RPC slot and buffer memory */ | |
580 | xprt_release(task); | |
d05fdb0c TM |
581 | } |
582 | } | |
d05fdb0c | 583 | } |
abbcf28f | 584 | EXPORT_SYMBOL(rpc_exit_task); |
d05fdb0c | 585 | |
1da177e4 LT |
586 | /* |
587 | * This is the RPC `scheduler' (or rather, the finite state machine). | |
588 | */ | |
589 | static int __rpc_execute(struct rpc_task *task) | |
590 | { | |
591 | int status = 0; | |
592 | ||
593 | dprintk("RPC: %4d rpc_execute flgs %x\n", | |
594 | task->tk_pid, task->tk_flags); | |
595 | ||
596 | BUG_ON(RPC_IS_QUEUED(task)); | |
597 | ||
d05fdb0c | 598 | for (;;) { |
1da177e4 LT |
599 | /* |
600 | * Garbage collection of pending timers... | |
601 | */ | |
602 | rpc_delete_timer(task); | |
603 | ||
604 | /* | |
605 | * Execute any pending callback. | |
606 | */ | |
607 | if (RPC_DO_CALLBACK(task)) { | |
608 | /* Define a callback save pointer */ | |
609 | void (*save_callback)(struct rpc_task *); | |
610 | ||
611 | /* | |
612 | * If a callback exists, save it, reset it, | |
613 | * call it. | |
614 | * The save is needed to stop from resetting | |
615 | * another callback set within the callback handler | |
616 | * - Dave | |
617 | */ | |
618 | save_callback=task->tk_callback; | |
619 | task->tk_callback=NULL; | |
620 | lock_kernel(); | |
621 | save_callback(task); | |
622 | unlock_kernel(); | |
623 | } | |
624 | ||
625 | /* | |
626 | * Perform the next FSM step. | |
627 | * tk_action may be NULL when the task has been killed | |
628 | * by someone else. | |
629 | */ | |
630 | if (!RPC_IS_QUEUED(task)) { | |
abbcf28f | 631 | if (task->tk_action == NULL) |
1da177e4 | 632 | break; |
abbcf28f TM |
633 | lock_kernel(); |
634 | task->tk_action(task); | |
635 | unlock_kernel(); | |
1da177e4 LT |
636 | } |
637 | ||
638 | /* | |
639 | * Lockless check for whether task is sleeping or not. | |
640 | */ | |
641 | if (!RPC_IS_QUEUED(task)) | |
642 | continue; | |
643 | rpc_clear_running(task); | |
644 | if (RPC_IS_ASYNC(task)) { | |
645 | /* Careful! we may have raced... */ | |
646 | if (RPC_IS_QUEUED(task)) | |
647 | return 0; | |
648 | if (rpc_test_and_set_running(task)) | |
649 | return 0; | |
650 | continue; | |
651 | } | |
652 | ||
653 | /* sync task: sleep here */ | |
654 | dprintk("RPC: %4d sync task going to sleep\n", task->tk_pid); | |
96651ab3 TM |
655 | /* Note: Caller should be using rpc_clnt_sigmask() */ |
656 | status = out_of_line_wait_on_bit(&task->tk_runstate, | |
657 | RPC_TASK_QUEUED, rpc_wait_bit_interruptible, | |
658 | TASK_INTERRUPTIBLE); | |
659 | if (status == -ERESTARTSYS) { | |
1da177e4 LT |
660 | /* |
661 | * When a sync task receives a signal, it exits with | |
662 | * -ERESTARTSYS. In order to catch any callbacks that | |
663 | * clean up after sleeping on some queue, we don't | |
664 | * break the loop here, but go around once more. | |
665 | */ | |
96651ab3 TM |
666 | dprintk("RPC: %4d got signal\n", task->tk_pid); |
667 | task->tk_flags |= RPC_TASK_KILLED; | |
668 | rpc_exit(task, -ERESTARTSYS); | |
669 | rpc_wake_up_task(task); | |
1da177e4 LT |
670 | } |
671 | rpc_set_running(task); | |
672 | dprintk("RPC: %4d sync task resuming\n", task->tk_pid); | |
673 | } | |
674 | ||
e60859ac | 675 | dprintk("RPC: %4d, return %d, status %d\n", task->tk_pid, status, task->tk_status); |
44c28873 TM |
676 | /* Wake up anyone who is waiting for task completion */ |
677 | rpc_mark_complete_task(task); | |
1da177e4 LT |
678 | /* Release all resources associated with the task */ |
679 | rpc_release_task(task); | |
680 | return status; | |
681 | } | |
682 | ||
683 | /* | |
684 | * User-visible entry point to the scheduler. | |
685 | * | |
686 | * This may be called recursively if e.g. an async NFS task updates | |
687 | * the attributes and finds that dirty pages must be flushed. | |
688 | * NOTE: Upon exit of this function the task is guaranteed to be | |
689 | * released. In particular note that tk_release() will have | |
690 | * been called, so your task memory may have been freed. | |
691 | */ | |
692 | int | |
693 | rpc_execute(struct rpc_task *task) | |
694 | { | |
44c28873 | 695 | rpc_set_active(task); |
1da177e4 LT |
696 | rpc_set_running(task); |
697 | return __rpc_execute(task); | |
698 | } | |
699 | ||
700 | static void rpc_async_schedule(void *arg) | |
701 | { | |
702 | __rpc_execute((struct rpc_task *)arg); | |
703 | } | |
704 | ||
02107148 CL |
705 | /** |
706 | * rpc_malloc - allocate an RPC buffer | |
707 | * @task: RPC task that will use this buffer | |
708 | * @size: requested byte size | |
1da177e4 LT |
709 | * |
710 | * We try to ensure that some NFS reads and writes can always proceed | |
711 | * by using a mempool when allocating 'small' buffers. | |
712 | * In order to avoid memory starvation triggering more writebacks of | |
713 | * NFS requests, we use GFP_NOFS rather than GFP_KERNEL. | |
714 | */ | |
02107148 | 715 | void * rpc_malloc(struct rpc_task *task, size_t size) |
1da177e4 | 716 | { |
02107148 | 717 | struct rpc_rqst *req = task->tk_rqstp; |
dd0fc66f | 718 | gfp_t gfp; |
1da177e4 LT |
719 | |
720 | if (task->tk_flags & RPC_TASK_SWAPPER) | |
721 | gfp = GFP_ATOMIC; | |
722 | else | |
723 | gfp = GFP_NOFS; | |
724 | ||
725 | if (size > RPC_BUFFER_MAXSIZE) { | |
02107148 CL |
726 | req->rq_buffer = kmalloc(size, gfp); |
727 | if (req->rq_buffer) | |
728 | req->rq_bufsize = size; | |
1da177e4 | 729 | } else { |
02107148 CL |
730 | req->rq_buffer = mempool_alloc(rpc_buffer_mempool, gfp); |
731 | if (req->rq_buffer) | |
732 | req->rq_bufsize = RPC_BUFFER_MAXSIZE; | |
1da177e4 | 733 | } |
02107148 | 734 | return req->rq_buffer; |
1da177e4 LT |
735 | } |
736 | ||
02107148 CL |
737 | /** |
738 | * rpc_free - free buffer allocated via rpc_malloc | |
739 | * @task: RPC task with a buffer to be freed | |
740 | * | |
741 | */ | |
742 | void rpc_free(struct rpc_task *task) | |
1da177e4 | 743 | { |
02107148 CL |
744 | struct rpc_rqst *req = task->tk_rqstp; |
745 | ||
746 | if (req->rq_buffer) { | |
747 | if (req->rq_bufsize == RPC_BUFFER_MAXSIZE) | |
748 | mempool_free(req->rq_buffer, rpc_buffer_mempool); | |
1da177e4 | 749 | else |
02107148 CL |
750 | kfree(req->rq_buffer); |
751 | req->rq_buffer = NULL; | |
752 | req->rq_bufsize = 0; | |
1da177e4 LT |
753 | } |
754 | } | |
755 | ||
756 | /* | |
757 | * Creation and deletion of RPC task structures | |
758 | */ | |
963d8fe5 | 759 | void rpc_init_task(struct rpc_task *task, struct rpc_clnt *clnt, int flags, const struct rpc_call_ops *tk_ops, void *calldata) |
1da177e4 LT |
760 | { |
761 | memset(task, 0, sizeof(*task)); | |
762 | init_timer(&task->tk_timer); | |
763 | task->tk_timer.data = (unsigned long) task; | |
764 | task->tk_timer.function = (void (*)(unsigned long)) rpc_run_timer; | |
44c28873 | 765 | atomic_set(&task->tk_count, 1); |
1da177e4 LT |
766 | task->tk_client = clnt; |
767 | task->tk_flags = flags; | |
963d8fe5 | 768 | task->tk_ops = tk_ops; |
4ce70ada TM |
769 | if (tk_ops->rpc_call_prepare != NULL) |
770 | task->tk_action = rpc_prepare_task; | |
963d8fe5 | 771 | task->tk_calldata = calldata; |
1da177e4 LT |
772 | |
773 | /* Initialize retry counters */ | |
774 | task->tk_garb_retry = 2; | |
775 | task->tk_cred_retry = 2; | |
776 | ||
777 | task->tk_priority = RPC_PRIORITY_NORMAL; | |
778 | task->tk_cookie = (unsigned long)current; | |
779 | ||
780 | /* Initialize workqueue for async tasks */ | |
781 | task->tk_workqueue = rpciod_workqueue; | |
1da177e4 LT |
782 | |
783 | if (clnt) { | |
784 | atomic_inc(&clnt->cl_users); | |
785 | if (clnt->cl_softrtry) | |
786 | task->tk_flags |= RPC_TASK_SOFT; | |
787 | if (!clnt->cl_intr) | |
788 | task->tk_flags |= RPC_TASK_NOINTR; | |
789 | } | |
790 | ||
791 | #ifdef RPC_DEBUG | |
792 | task->tk_magic = RPC_TASK_MAGIC_ID; | |
793 | task->tk_pid = rpc_task_id++; | |
794 | #endif | |
795 | /* Add to global list of all tasks */ | |
796 | spin_lock(&rpc_sched_lock); | |
797 | list_add_tail(&task->tk_task, &all_tasks); | |
798 | spin_unlock(&rpc_sched_lock); | |
799 | ||
963d8fe5 TM |
800 | BUG_ON(task->tk_ops == NULL); |
801 | ||
ef759a2e CL |
802 | /* starting timestamp */ |
803 | task->tk_start = jiffies; | |
804 | ||
1da177e4 LT |
805 | dprintk("RPC: %4d new task procpid %d\n", task->tk_pid, |
806 | current->pid); | |
807 | } | |
808 | ||
809 | static struct rpc_task * | |
810 | rpc_alloc_task(void) | |
811 | { | |
812 | return (struct rpc_task *)mempool_alloc(rpc_task_mempool, GFP_NOFS); | |
813 | } | |
814 | ||
963d8fe5 | 815 | static void rpc_free_task(struct rpc_task *task) |
1da177e4 LT |
816 | { |
817 | dprintk("RPC: %4d freeing task\n", task->tk_pid); | |
818 | mempool_free(task, rpc_task_mempool); | |
819 | } | |
820 | ||
821 | /* | |
822 | * Create a new task for the specified client. We have to | |
823 | * clean up after an allocation failure, as the client may | |
824 | * have specified "oneshot". | |
825 | */ | |
963d8fe5 | 826 | struct rpc_task *rpc_new_task(struct rpc_clnt *clnt, int flags, const struct rpc_call_ops *tk_ops, void *calldata) |
1da177e4 LT |
827 | { |
828 | struct rpc_task *task; | |
829 | ||
830 | task = rpc_alloc_task(); | |
831 | if (!task) | |
832 | goto cleanup; | |
833 | ||
963d8fe5 | 834 | rpc_init_task(task, clnt, flags, tk_ops, calldata); |
1da177e4 LT |
835 | |
836 | dprintk("RPC: %4d allocated task\n", task->tk_pid); | |
837 | task->tk_flags |= RPC_TASK_DYNAMIC; | |
838 | out: | |
839 | return task; | |
840 | ||
841 | cleanup: | |
842 | /* Check whether to release the client */ | |
843 | if (clnt) { | |
844 | printk("rpc_new_task: failed, users=%d, oneshot=%d\n", | |
845 | atomic_read(&clnt->cl_users), clnt->cl_oneshot); | |
846 | atomic_inc(&clnt->cl_users); /* pretend we were used ... */ | |
847 | rpc_release_client(clnt); | |
848 | } | |
849 | goto out; | |
850 | } | |
851 | ||
852 | void rpc_release_task(struct rpc_task *task) | |
853 | { | |
963d8fe5 TM |
854 | const struct rpc_call_ops *tk_ops = task->tk_ops; |
855 | void *calldata = task->tk_calldata; | |
1da177e4 LT |
856 | |
857 | #ifdef RPC_DEBUG | |
858 | BUG_ON(task->tk_magic != RPC_TASK_MAGIC_ID); | |
859 | #endif | |
44c28873 TM |
860 | if (!atomic_dec_and_test(&task->tk_count)) |
861 | return; | |
862 | dprintk("RPC: %4d release task\n", task->tk_pid); | |
1da177e4 LT |
863 | |
864 | /* Remove from global task list */ | |
865 | spin_lock(&rpc_sched_lock); | |
866 | list_del(&task->tk_task); | |
867 | spin_unlock(&rpc_sched_lock); | |
868 | ||
869 | BUG_ON (RPC_IS_QUEUED(task)); | |
1da177e4 LT |
870 | |
871 | /* Synchronously delete any running timer */ | |
872 | rpc_delete_timer(task); | |
873 | ||
874 | /* Release resources */ | |
875 | if (task->tk_rqstp) | |
876 | xprt_release(task); | |
877 | if (task->tk_msg.rpc_cred) | |
878 | rpcauth_unbindcred(task); | |
1da177e4 LT |
879 | if (task->tk_client) { |
880 | rpc_release_client(task->tk_client); | |
881 | task->tk_client = NULL; | |
882 | } | |
883 | ||
884 | #ifdef RPC_DEBUG | |
885 | task->tk_magic = 0; | |
886 | #endif | |
963d8fe5 TM |
887 | if (task->tk_flags & RPC_TASK_DYNAMIC) |
888 | rpc_free_task(task); | |
889 | if (tk_ops->rpc_release) | |
890 | tk_ops->rpc_release(calldata); | |
1da177e4 LT |
891 | } |
892 | ||
44c28873 TM |
893 | /** |
894 | * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it | |
99acf044 MW |
895 | * @clnt: pointer to RPC client |
896 | * @flags: RPC flags | |
897 | * @ops: RPC call ops | |
898 | * @data: user call data | |
44c28873 TM |
899 | */ |
900 | struct rpc_task *rpc_run_task(struct rpc_clnt *clnt, int flags, | |
901 | const struct rpc_call_ops *ops, | |
902 | void *data) | |
903 | { | |
904 | struct rpc_task *task; | |
905 | task = rpc_new_task(clnt, flags, ops, data); | |
7a1218a2 TM |
906 | if (task == NULL) { |
907 | if (ops->rpc_release != NULL) | |
908 | ops->rpc_release(data); | |
44c28873 | 909 | return ERR_PTR(-ENOMEM); |
7a1218a2 | 910 | } |
44c28873 TM |
911 | atomic_inc(&task->tk_count); |
912 | rpc_execute(task); | |
913 | return task; | |
914 | } | |
915 | EXPORT_SYMBOL(rpc_run_task); | |
916 | ||
1da177e4 LT |
917 | /* |
918 | * Kill all tasks for the given client. | |
919 | * XXX: kill their descendants as well? | |
920 | */ | |
921 | void rpc_killall_tasks(struct rpc_clnt *clnt) | |
922 | { | |
923 | struct rpc_task *rovr; | |
924 | struct list_head *le; | |
925 | ||
926 | dprintk("RPC: killing all tasks for client %p\n", clnt); | |
927 | ||
928 | /* | |
929 | * Spin lock all_tasks to prevent changes... | |
930 | */ | |
931 | spin_lock(&rpc_sched_lock); | |
932 | alltask_for_each(rovr, le, &all_tasks) { | |
933 | if (! RPC_IS_ACTIVATED(rovr)) | |
934 | continue; | |
935 | if (!clnt || rovr->tk_client == clnt) { | |
936 | rovr->tk_flags |= RPC_TASK_KILLED; | |
937 | rpc_exit(rovr, -EIO); | |
938 | rpc_wake_up_task(rovr); | |
939 | } | |
940 | } | |
941 | spin_unlock(&rpc_sched_lock); | |
942 | } | |
943 | ||
944 | static DECLARE_MUTEX_LOCKED(rpciod_running); | |
945 | ||
946 | static void rpciod_killall(void) | |
947 | { | |
948 | unsigned long flags; | |
949 | ||
950 | while (!list_empty(&all_tasks)) { | |
951 | clear_thread_flag(TIF_SIGPENDING); | |
952 | rpc_killall_tasks(NULL); | |
953 | flush_workqueue(rpciod_workqueue); | |
954 | if (!list_empty(&all_tasks)) { | |
955 | dprintk("rpciod_killall: waiting for tasks to exit\n"); | |
956 | yield(); | |
957 | } | |
958 | } | |
959 | ||
960 | spin_lock_irqsave(¤t->sighand->siglock, flags); | |
961 | recalc_sigpending(); | |
962 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | |
963 | } | |
964 | ||
965 | /* | |
966 | * Start up the rpciod process if it's not already running. | |
967 | */ | |
968 | int | |
969 | rpciod_up(void) | |
970 | { | |
971 | struct workqueue_struct *wq; | |
972 | int error = 0; | |
973 | ||
4a3e2f71 | 974 | mutex_lock(&rpciod_mutex); |
1da177e4 LT |
975 | dprintk("rpciod_up: users %d\n", rpciod_users); |
976 | rpciod_users++; | |
977 | if (rpciod_workqueue) | |
978 | goto out; | |
979 | /* | |
980 | * If there's no pid, we should be the first user. | |
981 | */ | |
982 | if (rpciod_users > 1) | |
983 | printk(KERN_WARNING "rpciod_up: no workqueue, %d users??\n", rpciod_users); | |
984 | /* | |
985 | * Create the rpciod thread and wait for it to start. | |
986 | */ | |
987 | error = -ENOMEM; | |
988 | wq = create_workqueue("rpciod"); | |
989 | if (wq == NULL) { | |
990 | printk(KERN_WARNING "rpciod_up: create workqueue failed, error=%d\n", error); | |
991 | rpciod_users--; | |
992 | goto out; | |
993 | } | |
994 | rpciod_workqueue = wq; | |
995 | error = 0; | |
996 | out: | |
4a3e2f71 | 997 | mutex_unlock(&rpciod_mutex); |
1da177e4 LT |
998 | return error; |
999 | } | |
1000 | ||
1001 | void | |
1002 | rpciod_down(void) | |
1003 | { | |
4a3e2f71 | 1004 | mutex_lock(&rpciod_mutex); |
1da177e4 LT |
1005 | dprintk("rpciod_down sema %d\n", rpciod_users); |
1006 | if (rpciod_users) { | |
1007 | if (--rpciod_users) | |
1008 | goto out; | |
1009 | } else | |
1010 | printk(KERN_WARNING "rpciod_down: no users??\n"); | |
1011 | ||
1012 | if (!rpciod_workqueue) { | |
1013 | dprintk("rpciod_down: Nothing to do!\n"); | |
1014 | goto out; | |
1015 | } | |
1016 | rpciod_killall(); | |
1017 | ||
1018 | destroy_workqueue(rpciod_workqueue); | |
1019 | rpciod_workqueue = NULL; | |
1020 | out: | |
4a3e2f71 | 1021 | mutex_unlock(&rpciod_mutex); |
1da177e4 LT |
1022 | } |
1023 | ||
1024 | #ifdef RPC_DEBUG | |
1025 | void rpc_show_tasks(void) | |
1026 | { | |
1027 | struct list_head *le; | |
1028 | struct rpc_task *t; | |
1029 | ||
1030 | spin_lock(&rpc_sched_lock); | |
1031 | if (list_empty(&all_tasks)) { | |
1032 | spin_unlock(&rpc_sched_lock); | |
1033 | return; | |
1034 | } | |
1035 | printk("-pid- proc flgs status -client- -prog- --rqstp- -timeout " | |
963d8fe5 | 1036 | "-rpcwait -action- ---ops--\n"); |
1da177e4 LT |
1037 | alltask_for_each(t, le, &all_tasks) { |
1038 | const char *rpc_waitq = "none"; | |
1039 | ||
1040 | if (RPC_IS_QUEUED(t)) | |
1041 | rpc_waitq = rpc_qname(t->u.tk_wait.rpc_waitq); | |
1042 | ||
1043 | printk("%05d %04d %04x %06d %8p %6d %8p %08ld %8s %8p %8p\n", | |
1044 | t->tk_pid, | |
1045 | (t->tk_msg.rpc_proc ? t->tk_msg.rpc_proc->p_proc : -1), | |
1046 | t->tk_flags, t->tk_status, | |
1047 | t->tk_client, | |
1048 | (t->tk_client ? t->tk_client->cl_prog : 0), | |
1049 | t->tk_rqstp, t->tk_timeout, | |
1050 | rpc_waitq, | |
963d8fe5 | 1051 | t->tk_action, t->tk_ops); |
1da177e4 LT |
1052 | } |
1053 | spin_unlock(&rpc_sched_lock); | |
1054 | } | |
1055 | #endif | |
1056 | ||
1057 | void | |
1058 | rpc_destroy_mempool(void) | |
1059 | { | |
1060 | if (rpc_buffer_mempool) | |
1061 | mempool_destroy(rpc_buffer_mempool); | |
1062 | if (rpc_task_mempool) | |
1063 | mempool_destroy(rpc_task_mempool); | |
1a1d92c1 AD |
1064 | if (rpc_task_slabp) |
1065 | kmem_cache_destroy(rpc_task_slabp); | |
1066 | if (rpc_buffer_slabp) | |
1067 | kmem_cache_destroy(rpc_buffer_slabp); | |
1da177e4 LT |
1068 | } |
1069 | ||
1070 | int | |
1071 | rpc_init_mempool(void) | |
1072 | { | |
1073 | rpc_task_slabp = kmem_cache_create("rpc_tasks", | |
1074 | sizeof(struct rpc_task), | |
1075 | 0, SLAB_HWCACHE_ALIGN, | |
1076 | NULL, NULL); | |
1077 | if (!rpc_task_slabp) | |
1078 | goto err_nomem; | |
1079 | rpc_buffer_slabp = kmem_cache_create("rpc_buffers", | |
1080 | RPC_BUFFER_MAXSIZE, | |
1081 | 0, SLAB_HWCACHE_ALIGN, | |
1082 | NULL, NULL); | |
1083 | if (!rpc_buffer_slabp) | |
1084 | goto err_nomem; | |
93d2341c MD |
1085 | rpc_task_mempool = mempool_create_slab_pool(RPC_TASK_POOLSIZE, |
1086 | rpc_task_slabp); | |
1da177e4 LT |
1087 | if (!rpc_task_mempool) |
1088 | goto err_nomem; | |
93d2341c MD |
1089 | rpc_buffer_mempool = mempool_create_slab_pool(RPC_BUFFER_POOLSIZE, |
1090 | rpc_buffer_slabp); | |
1da177e4 LT |
1091 | if (!rpc_buffer_mempool) |
1092 | goto err_nomem; | |
1093 | return 0; | |
1094 | err_nomem: | |
1095 | rpc_destroy_mempool(); | |
1096 | return -ENOMEM; | |
1097 | } |