2 * linux/net/sunrpc/sched.c
4 * Scheduling for synchronous and asynchronous RPC requests.
6 * Copyright (C) 1996 Olaf Kirch, <okir@monad.swb.de>
8 * TCP NFS related read + write fixes
9 * (C) 1999 Dave Airlie, University of Limerick, Ireland <airlied@linux.ie>
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/spinlock.h>
20 #include <linux/mutex.h>
22 #include <linux/sunrpc/clnt.h>
27 #define RPCDBG_FACILITY RPCDBG_SCHED
31 * RPC slabs and memory pools
33 #define RPC_BUFFER_MAXSIZE (2048)
34 #define RPC_BUFFER_POOLSIZE (8)
35 #define RPC_TASK_POOLSIZE (8)
36 static struct kmem_cache *rpc_task_slabp __read_mostly;
37 static struct kmem_cache *rpc_buffer_slabp __read_mostly;
38 static mempool_t *rpc_task_mempool __read_mostly;
39 static mempool_t *rpc_buffer_mempool __read_mostly;
41 static void rpc_async_schedule(struct work_struct *);
42 static void rpc_release_task(struct rpc_task *task);
43 static void __rpc_queue_timer_fn(unsigned long ptr);
46 * RPC tasks sit here while waiting for conditions to improve.
48 static struct rpc_wait_queue delay_queue;
51 * rpciod-related stuff
53 struct workqueue_struct *rpciod_workqueue;
56 * Disable the timer for a given RPC task. Should be called with
57 * queue->lock and bh_disabled in order to avoid races within
61 __rpc_disable_timer(struct rpc_wait_queue *queue, struct rpc_task *task)
63 if (task->tk_timeout == 0)
65 dprintk("RPC: %5u disabling timer\n", task->tk_pid);
67 list_del(&task->u.tk_wait.timer_list);
68 if (list_empty(&queue->timer_list.list))
69 del_timer(&queue->timer_list.timer);
73 rpc_set_queue_timer(struct rpc_wait_queue *queue, unsigned long expires)
75 queue->timer_list.expires = expires;
76 mod_timer(&queue->timer_list.timer, expires);
80 * Set up a timer for the current task.
83 __rpc_add_timer(struct rpc_wait_queue *queue, struct rpc_task *task)
85 if (!task->tk_timeout)
88 dprintk("RPC: %5u setting alarm for %lu ms\n",
89 task->tk_pid, task->tk_timeout * 1000 / HZ);
91 task->u.tk_wait.expires = jiffies + task->tk_timeout;
92 if (list_empty(&queue->timer_list.list) || time_before(task->u.tk_wait.expires, queue->timer_list.expires))
93 rpc_set_queue_timer(queue, task->u.tk_wait.expires);
94 list_add(&task->u.tk_wait.timer_list, &queue->timer_list.list);
98 * Add new request to a priority queue.
100 static void __rpc_add_wait_queue_priority(struct rpc_wait_queue *queue,
101 struct rpc_task *task,
102 unsigned char queue_priority)
107 INIT_LIST_HEAD(&task->u.tk_wait.links);
108 q = &queue->tasks[queue_priority];
109 if (unlikely(queue_priority > queue->maxpriority))
110 q = &queue->tasks[queue->maxpriority];
111 list_for_each_entry(t, q, u.tk_wait.list) {
112 if (t->tk_owner == task->tk_owner) {
113 list_add_tail(&task->u.tk_wait.list, &t->u.tk_wait.links);
117 list_add_tail(&task->u.tk_wait.list, q);
121 * Add new request to wait queue.
123 * Swapper tasks always get inserted at the head of the queue.
124 * This should avoid many nasty memory deadlocks and hopefully
125 * improve overall performance.
126 * Everyone else gets appended to the queue to ensure proper FIFO behavior.
128 static void __rpc_add_wait_queue(struct rpc_wait_queue *queue,
129 struct rpc_task *task,
130 unsigned char queue_priority)
132 BUG_ON (RPC_IS_QUEUED(task));
134 if (RPC_IS_PRIORITY(queue))
135 __rpc_add_wait_queue_priority(queue, task, queue_priority);
136 else if (RPC_IS_SWAPPER(task))
137 list_add(&task->u.tk_wait.list, &queue->tasks[0]);
139 list_add_tail(&task->u.tk_wait.list, &queue->tasks[0]);
140 task->tk_waitqueue = queue;
142 rpc_set_queued(task);
144 dprintk("RPC: %5u added to queue %p \"%s\"\n",
145 task->tk_pid, queue, rpc_qname(queue));
149 * Remove request from a priority queue.
151 static void __rpc_remove_wait_queue_priority(struct rpc_task *task)
155 if (!list_empty(&task->u.tk_wait.links)) {
156 t = list_entry(task->u.tk_wait.links.next, struct rpc_task, u.tk_wait.list);
157 list_move(&t->u.tk_wait.list, &task->u.tk_wait.list);
158 list_splice_init(&task->u.tk_wait.links, &t->u.tk_wait.links);
163 * Remove request from queue.
164 * Note: must be called with spin lock held.
166 static void __rpc_remove_wait_queue(struct rpc_wait_queue *queue, struct rpc_task *task)
168 __rpc_disable_timer(queue, task);
169 if (RPC_IS_PRIORITY(queue))
170 __rpc_remove_wait_queue_priority(task);
171 list_del(&task->u.tk_wait.list);
173 dprintk("RPC: %5u removed from queue %p \"%s\"\n",
174 task->tk_pid, queue, rpc_qname(queue));
177 static inline void rpc_set_waitqueue_priority(struct rpc_wait_queue *queue, int priority)
179 queue->priority = priority;
180 queue->count = 1 << (priority * 2);
183 static inline void rpc_set_waitqueue_owner(struct rpc_wait_queue *queue, pid_t pid)
186 queue->nr = RPC_BATCH_COUNT;
189 static inline void rpc_reset_waitqueue_priority(struct rpc_wait_queue *queue)
191 rpc_set_waitqueue_priority(queue, queue->maxpriority);
192 rpc_set_waitqueue_owner(queue, 0);
195 static void __rpc_init_priority_wait_queue(struct rpc_wait_queue *queue, const char *qname, unsigned char nr_queues)
199 spin_lock_init(&queue->lock);
200 for (i = 0; i < ARRAY_SIZE(queue->tasks); i++)
201 INIT_LIST_HEAD(&queue->tasks[i]);
202 queue->maxpriority = nr_queues - 1;
203 rpc_reset_waitqueue_priority(queue);
205 setup_timer(&queue->timer_list.timer, __rpc_queue_timer_fn, (unsigned long)queue);
206 INIT_LIST_HEAD(&queue->timer_list.list);
212 void rpc_init_priority_wait_queue(struct rpc_wait_queue *queue, const char *qname)
214 __rpc_init_priority_wait_queue(queue, qname, RPC_NR_PRIORITY);
216 EXPORT_SYMBOL_GPL(rpc_init_priority_wait_queue);
218 void rpc_init_wait_queue(struct rpc_wait_queue *queue, const char *qname)
220 __rpc_init_priority_wait_queue(queue, qname, 1);
222 EXPORT_SYMBOL_GPL(rpc_init_wait_queue);
224 void rpc_destroy_wait_queue(struct rpc_wait_queue *queue)
226 del_timer_sync(&queue->timer_list.timer);
228 EXPORT_SYMBOL_GPL(rpc_destroy_wait_queue);
230 static int rpc_wait_bit_killable(void *word)
232 if (fatal_signal_pending(current))
239 static void rpc_task_set_debuginfo(struct rpc_task *task)
241 static atomic_t rpc_pid;
243 task->tk_pid = atomic_inc_return(&rpc_pid);
246 static inline void rpc_task_set_debuginfo(struct rpc_task *task)
251 static void rpc_set_active(struct rpc_task *task)
253 rpc_task_set_debuginfo(task);
254 set_bit(RPC_TASK_ACTIVE, &task->tk_runstate);
258 * Mark an RPC call as having completed by clearing the 'active' bit
259 * and then waking up all tasks that were sleeping.
261 static int rpc_complete_task(struct rpc_task *task)
263 void *m = &task->tk_runstate;
264 wait_queue_head_t *wq = bit_waitqueue(m, RPC_TASK_ACTIVE);
265 struct wait_bit_key k = __WAIT_BIT_KEY_INITIALIZER(m, RPC_TASK_ACTIVE);
269 spin_lock_irqsave(&wq->lock, flags);
270 clear_bit(RPC_TASK_ACTIVE, &task->tk_runstate);
271 ret = atomic_dec_and_test(&task->tk_count);
272 if (waitqueue_active(wq))
273 __wake_up_locked_key(wq, TASK_NORMAL, &k);
274 spin_unlock_irqrestore(&wq->lock, flags);
279 * Allow callers to wait for completion of an RPC call
281 * Note the use of out_of_line_wait_on_bit() rather than wait_on_bit()
282 * to enforce taking of the wq->lock and hence avoid races with
283 * rpc_complete_task().
285 int __rpc_wait_for_completion_task(struct rpc_task *task, int (*action)(void *))
288 action = rpc_wait_bit_killable;
289 return out_of_line_wait_on_bit(&task->tk_runstate, RPC_TASK_ACTIVE,
290 action, TASK_KILLABLE);
292 EXPORT_SYMBOL_GPL(__rpc_wait_for_completion_task);
295 * Make an RPC task runnable.
297 * Note: If the task is ASYNC, this must be called with
298 * the spinlock held to protect the wait queue operation.
300 static void rpc_make_runnable(struct rpc_task *task)
302 rpc_clear_queued(task);
303 if (rpc_test_and_set_running(task))
305 if (RPC_IS_ASYNC(task)) {
306 INIT_WORK(&task->u.tk_work, rpc_async_schedule);
307 queue_work(rpciod_workqueue, &task->u.tk_work);
309 wake_up_bit(&task->tk_runstate, RPC_TASK_QUEUED);
313 * Prepare for sleeping on a wait queue.
314 * By always appending tasks to the list we ensure FIFO behavior.
315 * NB: An RPC task will only receive interrupt-driven events as long
316 * as it's on a wait queue.
318 static void __rpc_sleep_on_priority(struct rpc_wait_queue *q,
319 struct rpc_task *task,
321 unsigned char queue_priority)
323 dprintk("RPC: %5u sleep_on(queue \"%s\" time %lu)\n",
324 task->tk_pid, rpc_qname(q), jiffies);
326 __rpc_add_wait_queue(q, task, queue_priority);
328 BUG_ON(task->tk_callback != NULL);
329 task->tk_callback = action;
330 __rpc_add_timer(q, task);
333 void rpc_sleep_on(struct rpc_wait_queue *q, struct rpc_task *task,
336 /* We shouldn't ever put an inactive task to sleep */
337 BUG_ON(!RPC_IS_ACTIVATED(task));
340 * Protect the queue operations.
342 spin_lock_bh(&q->lock);
343 __rpc_sleep_on_priority(q, task, action, task->tk_priority);
344 spin_unlock_bh(&q->lock);
346 EXPORT_SYMBOL_GPL(rpc_sleep_on);
348 void rpc_sleep_on_priority(struct rpc_wait_queue *q, struct rpc_task *task,
349 rpc_action action, int priority)
351 /* We shouldn't ever put an inactive task to sleep */
352 BUG_ON(!RPC_IS_ACTIVATED(task));
355 * Protect the queue operations.
357 spin_lock_bh(&q->lock);
358 __rpc_sleep_on_priority(q, task, action, priority - RPC_PRIORITY_LOW);
359 spin_unlock_bh(&q->lock);
363 * __rpc_do_wake_up_task - wake up a single rpc_task
365 * @task: task to be woken up
367 * Caller must hold queue->lock, and have cleared the task queued flag.
369 static void __rpc_do_wake_up_task(struct rpc_wait_queue *queue, struct rpc_task *task)
371 dprintk("RPC: %5u __rpc_wake_up_task (now %lu)\n",
372 task->tk_pid, jiffies);
374 /* Has the task been executed yet? If not, we cannot wake it up! */
375 if (!RPC_IS_ACTIVATED(task)) {
376 printk(KERN_ERR "RPC: Inactive task (%p) being woken up!\n", task);
380 __rpc_remove_wait_queue(queue, task);
382 rpc_make_runnable(task);
384 dprintk("RPC: __rpc_wake_up_task done\n");
388 * Wake up a queued task while the queue lock is being held
390 static void rpc_wake_up_task_queue_locked(struct rpc_wait_queue *queue, struct rpc_task *task)
392 if (RPC_IS_QUEUED(task) && task->tk_waitqueue == queue)
393 __rpc_do_wake_up_task(queue, task);
397 * Tests whether rpc queue is empty
399 int rpc_queue_empty(struct rpc_wait_queue *queue)
403 spin_lock_bh(&queue->lock);
405 spin_unlock_bh(&queue->lock);
408 EXPORT_SYMBOL_GPL(rpc_queue_empty);
411 * Wake up a task on a specific queue
413 void rpc_wake_up_queued_task(struct rpc_wait_queue *queue, struct rpc_task *task)
415 spin_lock_bh(&queue->lock);
416 rpc_wake_up_task_queue_locked(queue, task);
417 spin_unlock_bh(&queue->lock);
419 EXPORT_SYMBOL_GPL(rpc_wake_up_queued_task);
422 * Wake up the next task on a priority queue.
424 static struct rpc_task * __rpc_wake_up_next_priority(struct rpc_wait_queue *queue)
427 struct rpc_task *task;
430 * Service a batch of tasks from a single owner.
432 q = &queue->tasks[queue->priority];
433 if (!list_empty(q)) {
434 task = list_entry(q->next, struct rpc_task, u.tk_wait.list);
435 if (queue->owner == task->tk_owner) {
438 list_move_tail(&task->u.tk_wait.list, q);
441 * Check if we need to switch queues.
448 * Service the next queue.
451 if (q == &queue->tasks[0])
452 q = &queue->tasks[queue->maxpriority];
455 if (!list_empty(q)) {
456 task = list_entry(q->next, struct rpc_task, u.tk_wait.list);
459 } while (q != &queue->tasks[queue->priority]);
461 rpc_reset_waitqueue_priority(queue);
465 rpc_set_waitqueue_priority(queue, (unsigned int)(q - &queue->tasks[0]));
467 rpc_set_waitqueue_owner(queue, task->tk_owner);
469 rpc_wake_up_task_queue_locked(queue, task);
474 * Wake up the next task on the wait queue.
476 struct rpc_task * rpc_wake_up_next(struct rpc_wait_queue *queue)
478 struct rpc_task *task = NULL;
480 dprintk("RPC: wake_up_next(%p \"%s\")\n",
481 queue, rpc_qname(queue));
482 spin_lock_bh(&queue->lock);
483 if (RPC_IS_PRIORITY(queue))
484 task = __rpc_wake_up_next_priority(queue);
486 task_for_first(task, &queue->tasks[0])
487 rpc_wake_up_task_queue_locked(queue, task);
489 spin_unlock_bh(&queue->lock);
493 EXPORT_SYMBOL_GPL(rpc_wake_up_next);
496 * rpc_wake_up - wake up all rpc_tasks
497 * @queue: rpc_wait_queue on which the tasks are sleeping
501 void rpc_wake_up(struct rpc_wait_queue *queue)
503 struct list_head *head;
505 spin_lock_bh(&queue->lock);
506 head = &queue->tasks[queue->maxpriority];
508 while (!list_empty(head)) {
509 struct rpc_task *task;
510 task = list_first_entry(head,
513 rpc_wake_up_task_queue_locked(queue, task);
515 if (head == &queue->tasks[0])
519 spin_unlock_bh(&queue->lock);
521 EXPORT_SYMBOL_GPL(rpc_wake_up);
524 * rpc_wake_up_status - wake up all rpc_tasks and set their status value.
525 * @queue: rpc_wait_queue on which the tasks are sleeping
526 * @status: status value to set
530 void rpc_wake_up_status(struct rpc_wait_queue *queue, int status)
532 struct list_head *head;
534 spin_lock_bh(&queue->lock);
535 head = &queue->tasks[queue->maxpriority];
537 while (!list_empty(head)) {
538 struct rpc_task *task;
539 task = list_first_entry(head,
542 task->tk_status = status;
543 rpc_wake_up_task_queue_locked(queue, task);
545 if (head == &queue->tasks[0])
549 spin_unlock_bh(&queue->lock);
551 EXPORT_SYMBOL_GPL(rpc_wake_up_status);
553 static void __rpc_queue_timer_fn(unsigned long ptr)
555 struct rpc_wait_queue *queue = (struct rpc_wait_queue *)ptr;
556 struct rpc_task *task, *n;
557 unsigned long expires, now, timeo;
559 spin_lock(&queue->lock);
560 expires = now = jiffies;
561 list_for_each_entry_safe(task, n, &queue->timer_list.list, u.tk_wait.timer_list) {
562 timeo = task->u.tk_wait.expires;
563 if (time_after_eq(now, timeo)) {
564 dprintk("RPC: %5u timeout\n", task->tk_pid);
565 task->tk_status = -ETIMEDOUT;
566 rpc_wake_up_task_queue_locked(queue, task);
569 if (expires == now || time_after(expires, timeo))
572 if (!list_empty(&queue->timer_list.list))
573 rpc_set_queue_timer(queue, expires);
574 spin_unlock(&queue->lock);
577 static void __rpc_atrun(struct rpc_task *task)
583 * Run a task at a later time
585 void rpc_delay(struct rpc_task *task, unsigned long delay)
587 task->tk_timeout = delay;
588 rpc_sleep_on(&delay_queue, task, __rpc_atrun);
590 EXPORT_SYMBOL_GPL(rpc_delay);
593 * Helper to call task->tk_ops->rpc_call_prepare
595 void rpc_prepare_task(struct rpc_task *task)
597 task->tk_ops->rpc_call_prepare(task, task->tk_calldata);
601 rpc_init_task_statistics(struct rpc_task *task)
603 /* Initialize retry counters */
604 task->tk_garb_retry = 2;
605 task->tk_cred_retry = 2;
606 task->tk_rebind_retry = 2;
608 /* starting timestamp */
609 task->tk_start = ktime_get();
613 rpc_reset_task_statistics(struct rpc_task *task)
615 task->tk_timeouts = 0;
616 task->tk_flags &= ~(RPC_CALL_MAJORSEEN|RPC_TASK_KILLED|RPC_TASK_SENT);
618 rpc_init_task_statistics(task);
622 * Helper that calls task->tk_ops->rpc_call_done if it exists
624 void rpc_exit_task(struct rpc_task *task)
626 task->tk_action = NULL;
627 if (task->tk_ops->rpc_call_done != NULL) {
628 task->tk_ops->rpc_call_done(task, task->tk_calldata);
629 if (task->tk_action != NULL) {
630 WARN_ON(RPC_ASSASSINATED(task));
631 /* Always release the RPC slot and buffer memory */
633 rpc_reset_task_statistics(task);
638 void rpc_exit(struct rpc_task *task, int status)
640 task->tk_status = status;
641 task->tk_action = rpc_exit_task;
642 if (RPC_IS_QUEUED(task))
643 rpc_wake_up_queued_task(task->tk_waitqueue, task);
645 EXPORT_SYMBOL_GPL(rpc_exit);
647 void rpc_release_calldata(const struct rpc_call_ops *ops, void *calldata)
649 if (ops->rpc_release != NULL)
650 ops->rpc_release(calldata);
654 * This is the RPC `scheduler' (or rather, the finite state machine).
656 static void __rpc_execute(struct rpc_task *task)
658 struct rpc_wait_queue *queue;
659 int task_is_async = RPC_IS_ASYNC(task);
662 dprintk("RPC: %5u __rpc_execute flags=0x%x\n",
663 task->tk_pid, task->tk_flags);
665 BUG_ON(RPC_IS_QUEUED(task));
668 void (*do_action)(struct rpc_task *);
671 * Execute any pending callback first.
673 do_action = task->tk_callback;
674 task->tk_callback = NULL;
675 if (do_action == NULL) {
677 * Perform the next FSM step.
678 * tk_action may be NULL if the task has been killed.
679 * In particular, note that rpc_killall_tasks may
680 * do this at any time, so beware when dereferencing.
682 do_action = task->tk_action;
683 if (do_action == NULL)
689 * Lockless check for whether task is sleeping or not.
691 if (!RPC_IS_QUEUED(task))
694 * The queue->lock protects against races with
695 * rpc_make_runnable().
697 * Note that once we clear RPC_TASK_RUNNING on an asynchronous
698 * rpc_task, rpc_make_runnable() can assign it to a
699 * different workqueue. We therefore cannot assume that the
700 * rpc_task pointer may still be dereferenced.
702 queue = task->tk_waitqueue;
703 spin_lock_bh(&queue->lock);
704 if (!RPC_IS_QUEUED(task)) {
705 spin_unlock_bh(&queue->lock);
708 rpc_clear_running(task);
709 spin_unlock_bh(&queue->lock);
713 /* sync task: sleep here */
714 dprintk("RPC: %5u sync task going to sleep\n", task->tk_pid);
715 status = out_of_line_wait_on_bit(&task->tk_runstate,
716 RPC_TASK_QUEUED, rpc_wait_bit_killable,
718 if (status == -ERESTARTSYS) {
720 * When a sync task receives a signal, it exits with
721 * -ERESTARTSYS. In order to catch any callbacks that
722 * clean up after sleeping on some queue, we don't
723 * break the loop here, but go around once more.
725 dprintk("RPC: %5u got signal\n", task->tk_pid);
726 task->tk_flags |= RPC_TASK_KILLED;
727 rpc_exit(task, -ERESTARTSYS);
729 rpc_set_running(task);
730 dprintk("RPC: %5u sync task resuming\n", task->tk_pid);
733 dprintk("RPC: %5u return %d, status %d\n", task->tk_pid, status,
735 /* Release all resources associated with the task */
736 rpc_release_task(task);
740 * User-visible entry point to the scheduler.
742 * This may be called recursively if e.g. an async NFS task updates
743 * the attributes and finds that dirty pages must be flushed.
744 * NOTE: Upon exit of this function the task is guaranteed to be
745 * released. In particular note that tk_release() will have
746 * been called, so your task memory may have been freed.
748 void rpc_execute(struct rpc_task *task)
750 rpc_set_active(task);
751 rpc_make_runnable(task);
752 if (!RPC_IS_ASYNC(task))
756 static void rpc_async_schedule(struct work_struct *work)
758 current->flags |= PF_FSTRANS;
759 __rpc_execute(container_of(work, struct rpc_task, u.tk_work));
760 current->flags &= ~PF_FSTRANS;
764 * rpc_malloc - allocate an RPC buffer
765 * @task: RPC task that will use this buffer
766 * @size: requested byte size
768 * To prevent rpciod from hanging, this allocator never sleeps,
769 * returning NULL if the request cannot be serviced immediately.
770 * The caller can arrange to sleep in a way that is safe for rpciod.
772 * Most requests are 'small' (under 2KiB) and can be serviced from a
773 * mempool, ensuring that NFS reads and writes can always proceed,
774 * and that there is good locality of reference for these buffers.
776 * In order to avoid memory starvation triggering more writebacks of
777 * NFS requests, we avoid using GFP_KERNEL.
779 void *rpc_malloc(struct rpc_task *task, size_t size)
781 struct rpc_buffer *buf;
782 gfp_t gfp = RPC_IS_SWAPPER(task) ? GFP_ATOMIC : GFP_NOWAIT;
784 size += sizeof(struct rpc_buffer);
785 if (size <= RPC_BUFFER_MAXSIZE)
786 buf = mempool_alloc(rpc_buffer_mempool, gfp);
788 buf = kmalloc(size, gfp);
794 dprintk("RPC: %5u allocated buffer of size %zu at %p\n",
795 task->tk_pid, size, buf);
798 EXPORT_SYMBOL_GPL(rpc_malloc);
801 * rpc_free - free buffer allocated via rpc_malloc
802 * @buffer: buffer to free
805 void rpc_free(void *buffer)
808 struct rpc_buffer *buf;
813 buf = container_of(buffer, struct rpc_buffer, data);
816 dprintk("RPC: freeing buffer of size %zu at %p\n",
819 if (size <= RPC_BUFFER_MAXSIZE)
820 mempool_free(buf, rpc_buffer_mempool);
824 EXPORT_SYMBOL_GPL(rpc_free);
827 * Creation and deletion of RPC task structures
829 static void rpc_init_task(struct rpc_task *task, const struct rpc_task_setup *task_setup_data)
831 memset(task, 0, sizeof(*task));
832 atomic_set(&task->tk_count, 1);
833 task->tk_flags = task_setup_data->flags;
834 task->tk_ops = task_setup_data->callback_ops;
835 task->tk_calldata = task_setup_data->callback_data;
836 INIT_LIST_HEAD(&task->tk_task);
838 task->tk_priority = task_setup_data->priority - RPC_PRIORITY_LOW;
839 task->tk_owner = current->tgid;
841 /* Initialize workqueue for async tasks */
842 task->tk_workqueue = task_setup_data->workqueue;
844 if (task->tk_ops->rpc_call_prepare != NULL)
845 task->tk_action = rpc_prepare_task;
847 rpc_init_task_statistics(task);
849 dprintk("RPC: new task initialized, procpid %u\n",
850 task_pid_nr(current));
853 static struct rpc_task *
856 return (struct rpc_task *)mempool_alloc(rpc_task_mempool, GFP_NOFS);
860 * Create a new task for the specified client.
862 struct rpc_task *rpc_new_task(const struct rpc_task_setup *setup_data)
864 struct rpc_task *task = setup_data->task;
865 unsigned short flags = 0;
868 task = rpc_alloc_task();
870 rpc_release_calldata(setup_data->callback_ops,
871 setup_data->callback_data);
872 return ERR_PTR(-ENOMEM);
874 flags = RPC_TASK_DYNAMIC;
877 rpc_init_task(task, setup_data);
878 task->tk_flags |= flags;
879 dprintk("RPC: allocated task %p\n", task);
883 static void rpc_free_task(struct rpc_task *task)
885 const struct rpc_call_ops *tk_ops = task->tk_ops;
886 void *calldata = task->tk_calldata;
888 if (task->tk_flags & RPC_TASK_DYNAMIC) {
889 dprintk("RPC: %5u freeing task\n", task->tk_pid);
890 mempool_free(task, rpc_task_mempool);
892 rpc_release_calldata(tk_ops, calldata);
895 static void rpc_async_release(struct work_struct *work)
897 rpc_free_task(container_of(work, struct rpc_task, u.tk_work));
900 static void rpc_release_resources_task(struct rpc_task *task)
904 if (task->tk_msg.rpc_cred) {
905 put_rpccred(task->tk_msg.rpc_cred);
906 task->tk_msg.rpc_cred = NULL;
908 rpc_task_release_client(task);
911 static void rpc_final_put_task(struct rpc_task *task,
912 struct workqueue_struct *q)
915 INIT_WORK(&task->u.tk_work, rpc_async_release);
916 queue_work(q, &task->u.tk_work);
921 static void rpc_do_put_task(struct rpc_task *task, struct workqueue_struct *q)
923 if (atomic_dec_and_test(&task->tk_count)) {
924 rpc_release_resources_task(task);
925 rpc_final_put_task(task, q);
929 void rpc_put_task(struct rpc_task *task)
931 rpc_do_put_task(task, NULL);
933 EXPORT_SYMBOL_GPL(rpc_put_task);
935 void rpc_put_task_async(struct rpc_task *task)
937 rpc_do_put_task(task, task->tk_workqueue);
939 EXPORT_SYMBOL_GPL(rpc_put_task_async);
941 static void rpc_release_task(struct rpc_task *task)
943 dprintk("RPC: %5u release task\n", task->tk_pid);
945 BUG_ON (RPC_IS_QUEUED(task));
947 rpc_release_resources_task(task);
950 * Note: at this point we have been removed from rpc_clnt->cl_tasks,
951 * so it should be safe to use task->tk_count as a test for whether
952 * or not any other processes still hold references to our rpc_task.
954 if (atomic_read(&task->tk_count) != 1 + !RPC_IS_ASYNC(task)) {
955 /* Wake up anyone who may be waiting for task completion */
956 if (!rpc_complete_task(task))
959 if (!atomic_dec_and_test(&task->tk_count))
962 rpc_final_put_task(task, task->tk_workqueue);
967 return try_module_get(THIS_MODULE) ? 0 : -EINVAL;
970 void rpciod_down(void)
972 module_put(THIS_MODULE);
976 * Start up the rpciod workqueue.
978 static int rpciod_start(void)
980 struct workqueue_struct *wq;
983 * Create the rpciod thread and wait for it to start.
985 dprintk("RPC: creating workqueue rpciod\n");
986 wq = alloc_workqueue("rpciod", WQ_MEM_RECLAIM, 0);
987 rpciod_workqueue = wq;
988 return rpciod_workqueue != NULL;
991 static void rpciod_stop(void)
993 struct workqueue_struct *wq = NULL;
995 if (rpciod_workqueue == NULL)
997 dprintk("RPC: destroying workqueue rpciod\n");
999 wq = rpciod_workqueue;
1000 rpciod_workqueue = NULL;
1001 destroy_workqueue(wq);
1005 rpc_destroy_mempool(void)
1008 if (rpc_buffer_mempool)
1009 mempool_destroy(rpc_buffer_mempool);
1010 if (rpc_task_mempool)
1011 mempool_destroy(rpc_task_mempool);
1013 kmem_cache_destroy(rpc_task_slabp);
1014 if (rpc_buffer_slabp)
1015 kmem_cache_destroy(rpc_buffer_slabp);
1016 rpc_destroy_wait_queue(&delay_queue);
1020 rpc_init_mempool(void)
1023 * The following is not strictly a mempool initialisation,
1024 * but there is no harm in doing it here
1026 rpc_init_wait_queue(&delay_queue, "delayq");
1027 if (!rpciod_start())
1030 rpc_task_slabp = kmem_cache_create("rpc_tasks",
1031 sizeof(struct rpc_task),
1032 0, SLAB_HWCACHE_ALIGN,
1034 if (!rpc_task_slabp)
1036 rpc_buffer_slabp = kmem_cache_create("rpc_buffers",
1038 0, SLAB_HWCACHE_ALIGN,
1040 if (!rpc_buffer_slabp)
1042 rpc_task_mempool = mempool_create_slab_pool(RPC_TASK_POOLSIZE,
1044 if (!rpc_task_mempool)
1046 rpc_buffer_mempool = mempool_create_slab_pool(RPC_BUFFER_POOLSIZE,
1048 if (!rpc_buffer_mempool)
1052 rpc_destroy_mempool();