ia64/linux-2.6.18-xen.hg

view net/sunrpc/sched.c @ 871:9cbcc9008446

xen/x86: don't initialize cpu_data[]'s apicid field on generic code

Afaict, this is not only redundant with the intialization done in
drivers/xen/core/smpboot.c, but actually results - at least for
secondary CPUs - in the Xen-specific value written to be later
overwritten with whatever the generic code determines (with no
guarantee that the two values are identical).

Signed-off-by: Jan Beulich <jbeulich@novell.com>
author Keir Fraser <keir.fraser@citrix.com>
date Thu May 14 10:09:15 2009 +0100 (2009-05-14)
parents 831230e53067
children
line source
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 */
12 #include <linux/module.h>
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>
21 #include <linux/mutex.h>
23 #include <linux/sunrpc/clnt.h>
24 #include <linux/sunrpc/xprt.h>
26 #ifdef RPC_DEBUG
27 #define RPCDBG_FACILITY RPCDBG_SCHED
28 #define RPC_TASK_MAGIC_ID 0xf00baa
29 static int rpc_task_id;
30 #endif
32 /*
33 * RPC slabs and memory pools
34 */
35 #define RPC_BUFFER_MAXSIZE (2048)
36 #define RPC_BUFFER_POOLSIZE (8)
37 #define RPC_TASK_POOLSIZE (8)
38 static kmem_cache_t *rpc_task_slabp __read_mostly;
39 static kmem_cache_t *rpc_buffer_slabp __read_mostly;
40 static mempool_t *rpc_task_mempool __read_mostly;
41 static mempool_t *rpc_buffer_mempool __read_mostly;
43 static void __rpc_default_timer(struct rpc_task *task);
44 static void rpciod_killall(void);
45 static void rpc_async_schedule(void *);
47 /*
48 * RPC tasks that create another task (e.g. for contacting the portmapper)
49 * will wait on this queue for their child's completion
50 */
51 static RPC_WAITQ(childq, "childq");
53 /*
54 * RPC tasks sit here while waiting for conditions to improve.
55 */
56 static RPC_WAITQ(delay_queue, "delayq");
58 /*
59 * All RPC tasks are linked into this list
60 */
61 static LIST_HEAD(all_tasks);
63 /*
64 * rpciod-related stuff
65 */
66 static DEFINE_MUTEX(rpciod_mutex);
67 static unsigned int rpciod_users;
68 struct workqueue_struct *rpciod_workqueue;
70 /*
71 * Spinlock for other critical sections of code.
72 */
73 static DEFINE_SPINLOCK(rpc_sched_lock);
75 /*
76 * Disable the timer for a given RPC task. Should be called with
77 * queue->lock and bh_disabled in order to avoid races within
78 * rpc_run_timer().
79 */
80 static inline void
81 __rpc_disable_timer(struct rpc_task *task)
82 {
83 dprintk("RPC: %4d disabling timer\n", task->tk_pid);
84 task->tk_timeout_fn = NULL;
85 task->tk_timeout = 0;
86 }
88 /*
89 * Run a timeout function.
90 * We use the callback in order to allow __rpc_wake_up_task()
91 * and friends to disable the timer synchronously on SMP systems
92 * without calling del_timer_sync(). The latter could cause a
93 * deadlock if called while we're holding spinlocks...
94 */
95 static void rpc_run_timer(struct rpc_task *task)
96 {
97 void (*callback)(struct rpc_task *);
99 callback = task->tk_timeout_fn;
100 task->tk_timeout_fn = NULL;
101 if (callback && RPC_IS_QUEUED(task)) {
102 dprintk("RPC: %4d running timer\n", task->tk_pid);
103 callback(task);
104 }
105 smp_mb__before_clear_bit();
106 clear_bit(RPC_TASK_HAS_TIMER, &task->tk_runstate);
107 smp_mb__after_clear_bit();
108 }
110 /*
111 * Set up a timer for the current task.
112 */
113 static inline void
114 __rpc_add_timer(struct rpc_task *task, rpc_action timer)
115 {
116 if (!task->tk_timeout)
117 return;
119 dprintk("RPC: %4d setting alarm for %lu ms\n",
120 task->tk_pid, task->tk_timeout * 1000 / HZ);
122 if (timer)
123 task->tk_timeout_fn = timer;
124 else
125 task->tk_timeout_fn = __rpc_default_timer;
126 set_bit(RPC_TASK_HAS_TIMER, &task->tk_runstate);
127 mod_timer(&task->tk_timer, jiffies + task->tk_timeout);
128 }
130 /*
131 * Delete any timer for the current task. Because we use del_timer_sync(),
132 * this function should never be called while holding queue->lock.
133 */
134 static void
135 rpc_delete_timer(struct rpc_task *task)
136 {
137 if (RPC_IS_QUEUED(task))
138 return;
139 if (test_and_clear_bit(RPC_TASK_HAS_TIMER, &task->tk_runstate)) {
140 del_singleshot_timer_sync(&task->tk_timer);
141 dprintk("RPC: %4d deleting timer\n", task->tk_pid);
142 }
143 }
145 /*
146 * Add new request to a priority queue.
147 */
148 static void __rpc_add_wait_queue_priority(struct rpc_wait_queue *queue, struct rpc_task *task)
149 {
150 struct list_head *q;
151 struct rpc_task *t;
153 INIT_LIST_HEAD(&task->u.tk_wait.links);
154 q = &queue->tasks[task->tk_priority];
155 if (unlikely(task->tk_priority > queue->maxpriority))
156 q = &queue->tasks[queue->maxpriority];
157 list_for_each_entry(t, q, u.tk_wait.list) {
158 if (t->tk_cookie == task->tk_cookie) {
159 list_add_tail(&task->u.tk_wait.list, &t->u.tk_wait.links);
160 return;
161 }
162 }
163 list_add_tail(&task->u.tk_wait.list, q);
164 }
166 /*
167 * Add new request to wait queue.
168 *
169 * Swapper tasks always get inserted at the head of the queue.
170 * This should avoid many nasty memory deadlocks and hopefully
171 * improve overall performance.
172 * Everyone else gets appended to the queue to ensure proper FIFO behavior.
173 */
174 static void __rpc_add_wait_queue(struct rpc_wait_queue *queue, struct rpc_task *task)
175 {
176 BUG_ON (RPC_IS_QUEUED(task));
178 if (RPC_IS_PRIORITY(queue))
179 __rpc_add_wait_queue_priority(queue, task);
180 else if (RPC_IS_SWAPPER(task))
181 list_add(&task->u.tk_wait.list, &queue->tasks[0]);
182 else
183 list_add_tail(&task->u.tk_wait.list, &queue->tasks[0]);
184 task->u.tk_wait.rpc_waitq = queue;
185 queue->qlen++;
186 rpc_set_queued(task);
188 dprintk("RPC: %4d added to queue %p \"%s\"\n",
189 task->tk_pid, queue, rpc_qname(queue));
190 }
192 /*
193 * Remove request from a priority queue.
194 */
195 static void __rpc_remove_wait_queue_priority(struct rpc_task *task)
196 {
197 struct rpc_task *t;
199 if (!list_empty(&task->u.tk_wait.links)) {
200 t = list_entry(task->u.tk_wait.links.next, struct rpc_task, u.tk_wait.list);
201 list_move(&t->u.tk_wait.list, &task->u.tk_wait.list);
202 list_splice_init(&task->u.tk_wait.links, &t->u.tk_wait.links);
203 }
204 list_del(&task->u.tk_wait.list);
205 }
207 /*
208 * Remove request from queue.
209 * Note: must be called with spin lock held.
210 */
211 static void __rpc_remove_wait_queue(struct rpc_task *task)
212 {
213 struct rpc_wait_queue *queue;
214 queue = task->u.tk_wait.rpc_waitq;
216 if (RPC_IS_PRIORITY(queue))
217 __rpc_remove_wait_queue_priority(task);
218 else
219 list_del(&task->u.tk_wait.list);
220 queue->qlen--;
221 dprintk("RPC: %4d removed from queue %p \"%s\"\n",
222 task->tk_pid, queue, rpc_qname(queue));
223 }
225 static inline void rpc_set_waitqueue_priority(struct rpc_wait_queue *queue, int priority)
226 {
227 queue->priority = priority;
228 queue->count = 1 << (priority * 2);
229 }
231 static inline void rpc_set_waitqueue_cookie(struct rpc_wait_queue *queue, unsigned long cookie)
232 {
233 queue->cookie = cookie;
234 queue->nr = RPC_BATCH_COUNT;
235 }
237 static inline void rpc_reset_waitqueue_priority(struct rpc_wait_queue *queue)
238 {
239 rpc_set_waitqueue_priority(queue, queue->maxpriority);
240 rpc_set_waitqueue_cookie(queue, 0);
241 }
243 static void __rpc_init_priority_wait_queue(struct rpc_wait_queue *queue, const char *qname, int maxprio)
244 {
245 int i;
247 spin_lock_init(&queue->lock);
248 for (i = 0; i < ARRAY_SIZE(queue->tasks); i++)
249 INIT_LIST_HEAD(&queue->tasks[i]);
250 queue->maxpriority = maxprio;
251 rpc_reset_waitqueue_priority(queue);
252 #ifdef RPC_DEBUG
253 queue->name = qname;
254 #endif
255 }
257 void rpc_init_priority_wait_queue(struct rpc_wait_queue *queue, const char *qname)
258 {
259 __rpc_init_priority_wait_queue(queue, qname, RPC_PRIORITY_HIGH);
260 }
262 void rpc_init_wait_queue(struct rpc_wait_queue *queue, const char *qname)
263 {
264 __rpc_init_priority_wait_queue(queue, qname, 0);
265 }
266 EXPORT_SYMBOL(rpc_init_wait_queue);
268 static int rpc_wait_bit_interruptible(void *word)
269 {
270 if (signal_pending(current))
271 return -ERESTARTSYS;
272 schedule();
273 return 0;
274 }
276 /*
277 * Mark an RPC call as having completed by clearing the 'active' bit
278 */
279 static inline void rpc_mark_complete_task(struct rpc_task *task)
280 {
281 rpc_clear_active(task);
282 wake_up_bit(&task->tk_runstate, RPC_TASK_ACTIVE);
283 }
285 /*
286 * Allow callers to wait for completion of an RPC call
287 */
288 int __rpc_wait_for_completion_task(struct rpc_task *task, int (*action)(void *))
289 {
290 if (action == NULL)
291 action = rpc_wait_bit_interruptible;
292 return wait_on_bit(&task->tk_runstate, RPC_TASK_ACTIVE,
293 action, TASK_INTERRUPTIBLE);
294 }
295 EXPORT_SYMBOL(__rpc_wait_for_completion_task);
297 /*
298 * Make an RPC task runnable.
299 *
300 * Note: If the task is ASYNC, this must be called with
301 * the spinlock held to protect the wait queue operation.
302 */
303 static void rpc_make_runnable(struct rpc_task *task)
304 {
305 int do_ret;
307 BUG_ON(task->tk_timeout_fn);
308 do_ret = rpc_test_and_set_running(task);
309 rpc_clear_queued(task);
310 if (do_ret)
311 return;
312 if (RPC_IS_ASYNC(task)) {
313 int status;
315 INIT_WORK(&task->u.tk_work, rpc_async_schedule, (void *)task);
316 status = queue_work(task->tk_workqueue, &task->u.tk_work);
317 if (status < 0) {
318 printk(KERN_WARNING "RPC: failed to add task to queue: error: %d!\n", status);
319 task->tk_status = status;
320 return;
321 }
322 } else
323 wake_up_bit(&task->tk_runstate, RPC_TASK_QUEUED);
324 }
326 /*
327 * Place a newly initialized task on the workqueue.
328 */
329 static inline void
330 rpc_schedule_run(struct rpc_task *task)
331 {
332 rpc_set_active(task);
333 rpc_make_runnable(task);
334 }
336 /*
337 * Prepare for sleeping on a wait queue.
338 * By always appending tasks to the list we ensure FIFO behavior.
339 * NB: An RPC task will only receive interrupt-driven events as long
340 * as it's on a wait queue.
341 */
342 static void __rpc_sleep_on(struct rpc_wait_queue *q, struct rpc_task *task,
343 rpc_action action, rpc_action timer)
344 {
345 dprintk("RPC: %4d sleep_on(queue \"%s\" time %ld)\n", task->tk_pid,
346 rpc_qname(q), jiffies);
348 if (!RPC_IS_ASYNC(task) && !RPC_IS_ACTIVATED(task)) {
349 printk(KERN_ERR "RPC: Inactive synchronous task put to sleep!\n");
350 return;
351 }
353 /* Mark the task as being activated if so needed */
354 rpc_set_active(task);
356 __rpc_add_wait_queue(q, task);
358 BUG_ON(task->tk_callback != NULL);
359 task->tk_callback = action;
360 __rpc_add_timer(task, timer);
361 }
363 void rpc_sleep_on(struct rpc_wait_queue *q, struct rpc_task *task,
364 rpc_action action, rpc_action timer)
365 {
366 /*
367 * Protect the queue operations.
368 */
369 spin_lock_bh(&q->lock);
370 __rpc_sleep_on(q, task, action, timer);
371 spin_unlock_bh(&q->lock);
372 }
374 /**
375 * __rpc_do_wake_up_task - wake up a single rpc_task
376 * @task: task to be woken up
377 *
378 * Caller must hold queue->lock, and have cleared the task queued flag.
379 */
380 static void __rpc_do_wake_up_task(struct rpc_task *task)
381 {
382 dprintk("RPC: %4d __rpc_wake_up_task (now %ld)\n", task->tk_pid, jiffies);
384 #ifdef RPC_DEBUG
385 BUG_ON(task->tk_magic != RPC_TASK_MAGIC_ID);
386 #endif
387 /* Has the task been executed yet? If not, we cannot wake it up! */
388 if (!RPC_IS_ACTIVATED(task)) {
389 printk(KERN_ERR "RPC: Inactive task (%p) being woken up!\n", task);
390 return;
391 }
393 __rpc_disable_timer(task);
394 __rpc_remove_wait_queue(task);
396 rpc_make_runnable(task);
398 dprintk("RPC: __rpc_wake_up_task done\n");
399 }
401 /*
402 * Wake up the specified task
403 */
404 static void __rpc_wake_up_task(struct rpc_task *task)
405 {
406 if (rpc_start_wakeup(task)) {
407 if (RPC_IS_QUEUED(task))
408 __rpc_do_wake_up_task(task);
409 rpc_finish_wakeup(task);
410 }
411 }
413 /*
414 * Default timeout handler if none specified by user
415 */
416 static void
417 __rpc_default_timer(struct rpc_task *task)
418 {
419 dprintk("RPC: %d timeout (default timer)\n", task->tk_pid);
420 task->tk_status = -ETIMEDOUT;
421 rpc_wake_up_task(task);
422 }
424 /*
425 * Wake up the specified task
426 */
427 void rpc_wake_up_task(struct rpc_task *task)
428 {
429 if (rpc_start_wakeup(task)) {
430 if (RPC_IS_QUEUED(task)) {
431 struct rpc_wait_queue *queue = task->u.tk_wait.rpc_waitq;
433 spin_lock_bh(&queue->lock);
434 __rpc_do_wake_up_task(task);
435 spin_unlock_bh(&queue->lock);
436 }
437 rpc_finish_wakeup(task);
438 }
439 }
441 /*
442 * Wake up the next task on a priority queue.
443 */
444 static struct rpc_task * __rpc_wake_up_next_priority(struct rpc_wait_queue *queue)
445 {
446 struct list_head *q;
447 struct rpc_task *task;
449 /*
450 * Service a batch of tasks from a single cookie.
451 */
452 q = &queue->tasks[queue->priority];
453 if (!list_empty(q)) {
454 task = list_entry(q->next, struct rpc_task, u.tk_wait.list);
455 if (queue->cookie == task->tk_cookie) {
456 if (--queue->nr)
457 goto out;
458 list_move_tail(&task->u.tk_wait.list, q);
459 }
460 /*
461 * Check if we need to switch queues.
462 */
463 if (--queue->count)
464 goto new_cookie;
465 }
467 /*
468 * Service the next queue.
469 */
470 do {
471 if (q == &queue->tasks[0])
472 q = &queue->tasks[queue->maxpriority];
473 else
474 q = q - 1;
475 if (!list_empty(q)) {
476 task = list_entry(q->next, struct rpc_task, u.tk_wait.list);
477 goto new_queue;
478 }
479 } while (q != &queue->tasks[queue->priority]);
481 rpc_reset_waitqueue_priority(queue);
482 return NULL;
484 new_queue:
485 rpc_set_waitqueue_priority(queue, (unsigned int)(q - &queue->tasks[0]));
486 new_cookie:
487 rpc_set_waitqueue_cookie(queue, task->tk_cookie);
488 out:
489 __rpc_wake_up_task(task);
490 return task;
491 }
493 /*
494 * Wake up the next task on the wait queue.
495 */
496 struct rpc_task * rpc_wake_up_next(struct rpc_wait_queue *queue)
497 {
498 struct rpc_task *task = NULL;
500 dprintk("RPC: wake_up_next(%p \"%s\")\n", queue, rpc_qname(queue));
501 spin_lock_bh(&queue->lock);
502 if (RPC_IS_PRIORITY(queue))
503 task = __rpc_wake_up_next_priority(queue);
504 else {
505 task_for_first(task, &queue->tasks[0])
506 __rpc_wake_up_task(task);
507 }
508 spin_unlock_bh(&queue->lock);
510 return task;
511 }
513 /**
514 * rpc_wake_up - wake up all rpc_tasks
515 * @queue: rpc_wait_queue on which the tasks are sleeping
516 *
517 * Grabs queue->lock
518 */
519 void rpc_wake_up(struct rpc_wait_queue *queue)
520 {
521 struct rpc_task *task, *next;
522 struct list_head *head;
524 spin_lock_bh(&queue->lock);
525 head = &queue->tasks[queue->maxpriority];
526 for (;;) {
527 list_for_each_entry_safe(task, next, head, u.tk_wait.list)
528 __rpc_wake_up_task(task);
529 if (head == &queue->tasks[0])
530 break;
531 head--;
532 }
533 spin_unlock_bh(&queue->lock);
534 }
536 /**
537 * rpc_wake_up_status - wake up all rpc_tasks and set their status value.
538 * @queue: rpc_wait_queue on which the tasks are sleeping
539 * @status: status value to set
540 *
541 * Grabs queue->lock
542 */
543 void rpc_wake_up_status(struct rpc_wait_queue *queue, int status)
544 {
545 struct rpc_task *task, *next;
546 struct list_head *head;
548 spin_lock_bh(&queue->lock);
549 head = &queue->tasks[queue->maxpriority];
550 for (;;) {
551 list_for_each_entry_safe(task, next, head, u.tk_wait.list) {
552 task->tk_status = status;
553 __rpc_wake_up_task(task);
554 }
555 if (head == &queue->tasks[0])
556 break;
557 head--;
558 }
559 spin_unlock_bh(&queue->lock);
560 }
562 /*
563 * Run a task at a later time
564 */
565 static void __rpc_atrun(struct rpc_task *);
566 void
567 rpc_delay(struct rpc_task *task, unsigned long delay)
568 {
569 task->tk_timeout = delay;
570 rpc_sleep_on(&delay_queue, task, NULL, __rpc_atrun);
571 }
573 static void
574 __rpc_atrun(struct rpc_task *task)
575 {
576 task->tk_status = 0;
577 rpc_wake_up_task(task);
578 }
580 /*
581 * Helper to call task->tk_ops->rpc_call_prepare
582 */
583 static void rpc_prepare_task(struct rpc_task *task)
584 {
585 task->tk_ops->rpc_call_prepare(task, task->tk_calldata);
586 }
588 /*
589 * Helper that calls task->tk_ops->rpc_call_done if it exists
590 */
591 void rpc_exit_task(struct rpc_task *task)
592 {
593 task->tk_action = NULL;
594 if (task->tk_ops->rpc_call_done != NULL) {
595 task->tk_ops->rpc_call_done(task, task->tk_calldata);
596 if (task->tk_action != NULL) {
597 WARN_ON(RPC_ASSASSINATED(task));
598 /* Always release the RPC slot and buffer memory */
599 xprt_release(task);
600 }
601 }
602 }
603 EXPORT_SYMBOL(rpc_exit_task);
605 /*
606 * This is the RPC `scheduler' (or rather, the finite state machine).
607 */
608 static int __rpc_execute(struct rpc_task *task)
609 {
610 int status = 0;
612 dprintk("RPC: %4d rpc_execute flgs %x\n",
613 task->tk_pid, task->tk_flags);
615 BUG_ON(RPC_IS_QUEUED(task));
617 for (;;) {
618 /*
619 * Garbage collection of pending timers...
620 */
621 rpc_delete_timer(task);
623 /*
624 * Execute any pending callback.
625 */
626 if (RPC_DO_CALLBACK(task)) {
627 /* Define a callback save pointer */
628 void (*save_callback)(struct rpc_task *);
630 /*
631 * If a callback exists, save it, reset it,
632 * call it.
633 * The save is needed to stop from resetting
634 * another callback set within the callback handler
635 * - Dave
636 */
637 save_callback=task->tk_callback;
638 task->tk_callback=NULL;
639 lock_kernel();
640 save_callback(task);
641 unlock_kernel();
642 }
644 /*
645 * Perform the next FSM step.
646 * tk_action may be NULL when the task has been killed
647 * by someone else.
648 */
649 if (!RPC_IS_QUEUED(task)) {
650 if (task->tk_action == NULL)
651 break;
652 lock_kernel();
653 task->tk_action(task);
654 unlock_kernel();
655 }
657 /*
658 * Lockless check for whether task is sleeping or not.
659 */
660 if (!RPC_IS_QUEUED(task))
661 continue;
662 rpc_clear_running(task);
663 if (RPC_IS_ASYNC(task)) {
664 /* Careful! we may have raced... */
665 if (RPC_IS_QUEUED(task))
666 return 0;
667 if (rpc_test_and_set_running(task))
668 return 0;
669 continue;
670 }
672 /* sync task: sleep here */
673 dprintk("RPC: %4d sync task going to sleep\n", task->tk_pid);
674 /* Note: Caller should be using rpc_clnt_sigmask() */
675 status = out_of_line_wait_on_bit(&task->tk_runstate,
676 RPC_TASK_QUEUED, rpc_wait_bit_interruptible,
677 TASK_INTERRUPTIBLE);
678 if (status == -ERESTARTSYS) {
679 /*
680 * When a sync task receives a signal, it exits with
681 * -ERESTARTSYS. In order to catch any callbacks that
682 * clean up after sleeping on some queue, we don't
683 * break the loop here, but go around once more.
684 */
685 dprintk("RPC: %4d got signal\n", task->tk_pid);
686 task->tk_flags |= RPC_TASK_KILLED;
687 rpc_exit(task, -ERESTARTSYS);
688 rpc_wake_up_task(task);
689 }
690 rpc_set_running(task);
691 dprintk("RPC: %4d sync task resuming\n", task->tk_pid);
692 }
694 dprintk("RPC: %4d, return %d, status %d\n", task->tk_pid, status, task->tk_status);
695 /* Wake up anyone who is waiting for task completion */
696 rpc_mark_complete_task(task);
697 /* Release all resources associated with the task */
698 rpc_release_task(task);
699 return status;
700 }
702 /*
703 * User-visible entry point to the scheduler.
704 *
705 * This may be called recursively if e.g. an async NFS task updates
706 * the attributes and finds that dirty pages must be flushed.
707 * NOTE: Upon exit of this function the task is guaranteed to be
708 * released. In particular note that tk_release() will have
709 * been called, so your task memory may have been freed.
710 */
711 int
712 rpc_execute(struct rpc_task *task)
713 {
714 rpc_set_active(task);
715 rpc_set_running(task);
716 return __rpc_execute(task);
717 }
719 static void rpc_async_schedule(void *arg)
720 {
721 __rpc_execute((struct rpc_task *)arg);
722 }
724 /**
725 * rpc_malloc - allocate an RPC buffer
726 * @task: RPC task that will use this buffer
727 * @size: requested byte size
728 *
729 * We try to ensure that some NFS reads and writes can always proceed
730 * by using a mempool when allocating 'small' buffers.
731 * In order to avoid memory starvation triggering more writebacks of
732 * NFS requests, we use GFP_NOFS rather than GFP_KERNEL.
733 */
734 void * rpc_malloc(struct rpc_task *task, size_t size)
735 {
736 struct rpc_rqst *req = task->tk_rqstp;
737 gfp_t gfp;
739 if (task->tk_flags & RPC_TASK_SWAPPER)
740 gfp = GFP_ATOMIC;
741 else
742 gfp = GFP_NOFS;
744 if (size > RPC_BUFFER_MAXSIZE) {
745 req->rq_buffer = kmalloc(size, gfp);
746 if (req->rq_buffer)
747 req->rq_bufsize = size;
748 } else {
749 req->rq_buffer = mempool_alloc(rpc_buffer_mempool, gfp);
750 if (req->rq_buffer)
751 req->rq_bufsize = RPC_BUFFER_MAXSIZE;
752 }
753 return req->rq_buffer;
754 }
756 /**
757 * rpc_free - free buffer allocated via rpc_malloc
758 * @task: RPC task with a buffer to be freed
759 *
760 */
761 void rpc_free(struct rpc_task *task)
762 {
763 struct rpc_rqst *req = task->tk_rqstp;
765 if (req->rq_buffer) {
766 if (req->rq_bufsize == RPC_BUFFER_MAXSIZE)
767 mempool_free(req->rq_buffer, rpc_buffer_mempool);
768 else
769 kfree(req->rq_buffer);
770 req->rq_buffer = NULL;
771 req->rq_bufsize = 0;
772 }
773 }
775 /*
776 * Creation and deletion of RPC task structures
777 */
778 void rpc_init_task(struct rpc_task *task, struct rpc_clnt *clnt, int flags, const struct rpc_call_ops *tk_ops, void *calldata)
779 {
780 memset(task, 0, sizeof(*task));
781 init_timer(&task->tk_timer);
782 task->tk_timer.data = (unsigned long) task;
783 task->tk_timer.function = (void (*)(unsigned long)) rpc_run_timer;
784 atomic_set(&task->tk_count, 1);
785 task->tk_client = clnt;
786 task->tk_flags = flags;
787 task->tk_ops = tk_ops;
788 if (tk_ops->rpc_call_prepare != NULL)
789 task->tk_action = rpc_prepare_task;
790 task->tk_calldata = calldata;
792 /* Initialize retry counters */
793 task->tk_garb_retry = 2;
794 task->tk_cred_retry = 2;
796 task->tk_priority = RPC_PRIORITY_NORMAL;
797 task->tk_cookie = (unsigned long)current;
799 /* Initialize workqueue for async tasks */
800 task->tk_workqueue = rpciod_workqueue;
802 if (clnt) {
803 atomic_inc(&clnt->cl_users);
804 if (clnt->cl_softrtry)
805 task->tk_flags |= RPC_TASK_SOFT;
806 if (!clnt->cl_intr)
807 task->tk_flags |= RPC_TASK_NOINTR;
808 }
810 #ifdef RPC_DEBUG
811 task->tk_magic = RPC_TASK_MAGIC_ID;
812 task->tk_pid = rpc_task_id++;
813 #endif
814 /* Add to global list of all tasks */
815 spin_lock(&rpc_sched_lock);
816 list_add_tail(&task->tk_task, &all_tasks);
817 spin_unlock(&rpc_sched_lock);
819 BUG_ON(task->tk_ops == NULL);
821 /* starting timestamp */
822 task->tk_start = jiffies;
824 dprintk("RPC: %4d new task procpid %d\n", task->tk_pid,
825 current->pid);
826 }
828 static struct rpc_task *
829 rpc_alloc_task(void)
830 {
831 return (struct rpc_task *)mempool_alloc(rpc_task_mempool, GFP_NOFS);
832 }
834 static void rpc_free_task(struct rpc_task *task)
835 {
836 dprintk("RPC: %4d freeing task\n", task->tk_pid);
837 mempool_free(task, rpc_task_mempool);
838 }
840 /*
841 * Create a new task for the specified client. We have to
842 * clean up after an allocation failure, as the client may
843 * have specified "oneshot".
844 */
845 struct rpc_task *rpc_new_task(struct rpc_clnt *clnt, int flags, const struct rpc_call_ops *tk_ops, void *calldata)
846 {
847 struct rpc_task *task;
849 task = rpc_alloc_task();
850 if (!task)
851 goto cleanup;
853 rpc_init_task(task, clnt, flags, tk_ops, calldata);
855 dprintk("RPC: %4d allocated task\n", task->tk_pid);
856 task->tk_flags |= RPC_TASK_DYNAMIC;
857 out:
858 return task;
860 cleanup:
861 /* Check whether to release the client */
862 if (clnt) {
863 printk("rpc_new_task: failed, users=%d, oneshot=%d\n",
864 atomic_read(&clnt->cl_users), clnt->cl_oneshot);
865 atomic_inc(&clnt->cl_users); /* pretend we were used ... */
866 rpc_release_client(clnt);
867 }
868 goto out;
869 }
871 void rpc_release_task(struct rpc_task *task)
872 {
873 const struct rpc_call_ops *tk_ops = task->tk_ops;
874 void *calldata = task->tk_calldata;
876 #ifdef RPC_DEBUG
877 BUG_ON(task->tk_magic != RPC_TASK_MAGIC_ID);
878 #endif
879 if (!atomic_dec_and_test(&task->tk_count))
880 return;
881 dprintk("RPC: %4d release task\n", task->tk_pid);
883 /* Remove from global task list */
884 spin_lock(&rpc_sched_lock);
885 list_del(&task->tk_task);
886 spin_unlock(&rpc_sched_lock);
888 BUG_ON (RPC_IS_QUEUED(task));
890 /* Synchronously delete any running timer */
891 rpc_delete_timer(task);
893 /* Release resources */
894 if (task->tk_rqstp)
895 xprt_release(task);
896 if (task->tk_msg.rpc_cred)
897 rpcauth_unbindcred(task);
898 if (task->tk_client) {
899 rpc_release_client(task->tk_client);
900 task->tk_client = NULL;
901 }
903 #ifdef RPC_DEBUG
904 task->tk_magic = 0;
905 #endif
906 if (task->tk_flags & RPC_TASK_DYNAMIC)
907 rpc_free_task(task);
908 if (tk_ops->rpc_release)
909 tk_ops->rpc_release(calldata);
910 }
912 /**
913 * rpc_run_task - Allocate a new RPC task, then run rpc_execute against it
914 * @clnt: pointer to RPC client
915 * @flags: RPC flags
916 * @ops: RPC call ops
917 * @data: user call data
918 */
919 struct rpc_task *rpc_run_task(struct rpc_clnt *clnt, int flags,
920 const struct rpc_call_ops *ops,
921 void *data)
922 {
923 struct rpc_task *task;
924 task = rpc_new_task(clnt, flags, ops, data);
925 if (task == NULL) {
926 if (ops->rpc_release != NULL)
927 ops->rpc_release(data);
928 return ERR_PTR(-ENOMEM);
929 }
930 atomic_inc(&task->tk_count);
931 rpc_execute(task);
932 return task;
933 }
934 EXPORT_SYMBOL(rpc_run_task);
936 /**
937 * rpc_find_parent - find the parent of a child task.
938 * @child: child task
939 * @parent: parent task
940 *
941 * Checks that the parent task is still sleeping on the
942 * queue 'childq'. If so returns a pointer to the parent.
943 * Upon failure returns NULL.
944 *
945 * Caller must hold childq.lock
946 */
947 static inline struct rpc_task *rpc_find_parent(struct rpc_task *child, struct rpc_task *parent)
948 {
949 struct rpc_task *task;
950 struct list_head *le;
952 task_for_each(task, le, &childq.tasks[0])
953 if (task == parent)
954 return parent;
956 return NULL;
957 }
959 static void rpc_child_exit(struct rpc_task *child, void *calldata)
960 {
961 struct rpc_task *parent;
963 spin_lock_bh(&childq.lock);
964 if ((parent = rpc_find_parent(child, calldata)) != NULL) {
965 parent->tk_status = child->tk_status;
966 __rpc_wake_up_task(parent);
967 }
968 spin_unlock_bh(&childq.lock);
969 }
971 static const struct rpc_call_ops rpc_child_ops = {
972 .rpc_call_done = rpc_child_exit,
973 };
975 /*
976 * Note: rpc_new_task releases the client after a failure.
977 */
978 struct rpc_task *
979 rpc_new_child(struct rpc_clnt *clnt, struct rpc_task *parent)
980 {
981 struct rpc_task *task;
983 task = rpc_new_task(clnt, RPC_TASK_ASYNC | RPC_TASK_CHILD, &rpc_child_ops, parent);
984 if (!task)
985 goto fail;
986 return task;
988 fail:
989 parent->tk_status = -ENOMEM;
990 return NULL;
991 }
993 void rpc_run_child(struct rpc_task *task, struct rpc_task *child, rpc_action func)
994 {
995 spin_lock_bh(&childq.lock);
996 /* N.B. Is it possible for the child to have already finished? */
997 __rpc_sleep_on(&childq, task, func, NULL);
998 rpc_schedule_run(child);
999 spin_unlock_bh(&childq.lock);
1002 /*
1003 * Kill all tasks for the given client.
1004 * XXX: kill their descendants as well?
1005 */
1006 void rpc_killall_tasks(struct rpc_clnt *clnt)
1008 struct rpc_task *rovr;
1009 struct list_head *le;
1011 dprintk("RPC: killing all tasks for client %p\n", clnt);
1013 /*
1014 * Spin lock all_tasks to prevent changes...
1015 */
1016 spin_lock(&rpc_sched_lock);
1017 alltask_for_each(rovr, le, &all_tasks) {
1018 if (! RPC_IS_ACTIVATED(rovr))
1019 continue;
1020 if (!clnt || rovr->tk_client == clnt) {
1021 rovr->tk_flags |= RPC_TASK_KILLED;
1022 rpc_exit(rovr, -EIO);
1023 rpc_wake_up_task(rovr);
1026 spin_unlock(&rpc_sched_lock);
1029 static DECLARE_MUTEX_LOCKED(rpciod_running);
1031 static void rpciod_killall(void)
1033 unsigned long flags;
1035 while (!list_empty(&all_tasks)) {
1036 clear_thread_flag(TIF_SIGPENDING);
1037 rpc_killall_tasks(NULL);
1038 flush_workqueue(rpciod_workqueue);
1039 if (!list_empty(&all_tasks)) {
1040 dprintk("rpciod_killall: waiting for tasks to exit\n");
1041 yield();
1045 spin_lock_irqsave(&current->sighand->siglock, flags);
1046 recalc_sigpending();
1047 spin_unlock_irqrestore(&current->sighand->siglock, flags);
1050 /*
1051 * Start up the rpciod process if it's not already running.
1052 */
1053 int
1054 rpciod_up(void)
1056 struct workqueue_struct *wq;
1057 int error = 0;
1059 mutex_lock(&rpciod_mutex);
1060 dprintk("rpciod_up: users %d\n", rpciod_users);
1061 rpciod_users++;
1062 if (rpciod_workqueue)
1063 goto out;
1064 /*
1065 * If there's no pid, we should be the first user.
1066 */
1067 if (rpciod_users > 1)
1068 printk(KERN_WARNING "rpciod_up: no workqueue, %d users??\n", rpciod_users);
1069 /*
1070 * Create the rpciod thread and wait for it to start.
1071 */
1072 error = -ENOMEM;
1073 wq = create_workqueue("rpciod");
1074 if (wq == NULL) {
1075 printk(KERN_WARNING "rpciod_up: create workqueue failed, error=%d\n", error);
1076 rpciod_users--;
1077 goto out;
1079 rpciod_workqueue = wq;
1080 error = 0;
1081 out:
1082 mutex_unlock(&rpciod_mutex);
1083 return error;
1086 void
1087 rpciod_down(void)
1089 mutex_lock(&rpciod_mutex);
1090 dprintk("rpciod_down sema %d\n", rpciod_users);
1091 if (rpciod_users) {
1092 if (--rpciod_users)
1093 goto out;
1094 } else
1095 printk(KERN_WARNING "rpciod_down: no users??\n");
1097 if (!rpciod_workqueue) {
1098 dprintk("rpciod_down: Nothing to do!\n");
1099 goto out;
1101 rpciod_killall();
1103 destroy_workqueue(rpciod_workqueue);
1104 rpciod_workqueue = NULL;
1105 out:
1106 mutex_unlock(&rpciod_mutex);
1109 #ifdef RPC_DEBUG
1110 void rpc_show_tasks(void)
1112 struct list_head *le;
1113 struct rpc_task *t;
1115 spin_lock(&rpc_sched_lock);
1116 if (list_empty(&all_tasks)) {
1117 spin_unlock(&rpc_sched_lock);
1118 return;
1120 printk("-pid- proc flgs status -client- -prog- --rqstp- -timeout "
1121 "-rpcwait -action- ---ops--\n");
1122 alltask_for_each(t, le, &all_tasks) {
1123 const char *rpc_waitq = "none";
1125 if (RPC_IS_QUEUED(t))
1126 rpc_waitq = rpc_qname(t->u.tk_wait.rpc_waitq);
1128 printk("%05d %04d %04x %06d %8p %6d %8p %08ld %8s %8p %8p\n",
1129 t->tk_pid,
1130 (t->tk_msg.rpc_proc ? t->tk_msg.rpc_proc->p_proc : -1),
1131 t->tk_flags, t->tk_status,
1132 t->tk_client,
1133 (t->tk_client ? t->tk_client->cl_prog : 0),
1134 t->tk_rqstp, t->tk_timeout,
1135 rpc_waitq,
1136 t->tk_action, t->tk_ops);
1138 spin_unlock(&rpc_sched_lock);
1140 #endif
1142 void
1143 rpc_destroy_mempool(void)
1145 if (rpc_buffer_mempool)
1146 mempool_destroy(rpc_buffer_mempool);
1147 if (rpc_task_mempool)
1148 mempool_destroy(rpc_task_mempool);
1149 if (rpc_task_slabp && kmem_cache_destroy(rpc_task_slabp))
1150 printk(KERN_INFO "rpc_task: not all structures were freed\n");
1151 if (rpc_buffer_slabp && kmem_cache_destroy(rpc_buffer_slabp))
1152 printk(KERN_INFO "rpc_buffers: not all structures were freed\n");
1155 int
1156 rpc_init_mempool(void)
1158 rpc_task_slabp = kmem_cache_create("rpc_tasks",
1159 sizeof(struct rpc_task),
1160 0, SLAB_HWCACHE_ALIGN,
1161 NULL, NULL);
1162 if (!rpc_task_slabp)
1163 goto err_nomem;
1164 rpc_buffer_slabp = kmem_cache_create("rpc_buffers",
1165 RPC_BUFFER_MAXSIZE,
1166 0, SLAB_HWCACHE_ALIGN,
1167 NULL, NULL);
1168 if (!rpc_buffer_slabp)
1169 goto err_nomem;
1170 rpc_task_mempool = mempool_create_slab_pool(RPC_TASK_POOLSIZE,
1171 rpc_task_slabp);
1172 if (!rpc_task_mempool)
1173 goto err_nomem;
1174 rpc_buffer_mempool = mempool_create_slab_pool(RPC_BUFFER_POOLSIZE,
1175 rpc_buffer_slabp);
1176 if (!rpc_buffer_mempool)
1177 goto err_nomem;
1178 return 0;
1179 err_nomem:
1180 rpc_destroy_mempool();
1181 return -ENOMEM;