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 rpc_task *task, *next;
504 struct list_head *head;
506 spin_lock_bh(&queue->lock);
507 head = &queue->tasks[queue->maxpriority];
509 list_for_each_entry_safe(task, next, head, u.tk_wait.list)
510 rpc_wake_up_task_queue_locked(queue, task);
511 if (head == &queue->tasks[0])
515 spin_unlock_bh(&queue->lock);
517 EXPORT_SYMBOL_GPL(rpc_wake_up);
520 * rpc_wake_up_status - wake up all rpc_tasks and set their status value.
521 * @queue: rpc_wait_queue on which the tasks are sleeping
522 * @status: status value to set
526 void rpc_wake_up_status(struct rpc_wait_queue *queue, int status)
528 struct rpc_task *task, *next;
529 struct list_head *head;
531 spin_lock_bh(&queue->lock);
532 head = &queue->tasks[queue->maxpriority];
534 list_for_each_entry_safe(task, next, head, u.tk_wait.list) {
535 task->tk_status = status;
536 rpc_wake_up_task_queue_locked(queue, task);
538 if (head == &queue->tasks[0])
542 spin_unlock_bh(&queue->lock);
544 EXPORT_SYMBOL_GPL(rpc_wake_up_status);
546 static void __rpc_queue_timer_fn(unsigned long ptr)
548 struct rpc_wait_queue *queue = (struct rpc_wait_queue *)ptr;
549 struct rpc_task *task, *n;
550 unsigned long expires, now, timeo;
552 spin_lock(&queue->lock);
553 expires = now = jiffies;
554 list_for_each_entry_safe(task, n, &queue->timer_list.list, u.tk_wait.timer_list) {
555 timeo = task->u.tk_wait.expires;
556 if (time_after_eq(now, timeo)) {
557 dprintk("RPC: %5u timeout\n", task->tk_pid);
558 task->tk_status = -ETIMEDOUT;
559 rpc_wake_up_task_queue_locked(queue, task);
562 if (expires == now || time_after(expires, timeo))
565 if (!list_empty(&queue->timer_list.list))
566 rpc_set_queue_timer(queue, expires);
567 spin_unlock(&queue->lock);
570 static void __rpc_atrun(struct rpc_task *task)
576 * Run a task at a later time
578 void rpc_delay(struct rpc_task *task, unsigned long delay)
580 task->tk_timeout = delay;
581 rpc_sleep_on(&delay_queue, task, __rpc_atrun);
583 EXPORT_SYMBOL_GPL(rpc_delay);
586 * Helper to call task->tk_ops->rpc_call_prepare
588 void rpc_prepare_task(struct rpc_task *task)
590 task->tk_ops->rpc_call_prepare(task, task->tk_calldata);
594 rpc_init_task_statistics(struct rpc_task *task)
596 /* Initialize retry counters */
597 task->tk_garb_retry = 2;
598 task->tk_cred_retry = 2;
599 task->tk_rebind_retry = 2;
601 /* starting timestamp */
602 task->tk_start = ktime_get();
606 rpc_reset_task_statistics(struct rpc_task *task)
608 task->tk_timeouts = 0;
609 task->tk_flags &= ~(RPC_CALL_MAJORSEEN|RPC_TASK_KILLED|RPC_TASK_SENT);
611 rpc_init_task_statistics(task);
615 * Helper that calls task->tk_ops->rpc_call_done if it exists
617 void rpc_exit_task(struct rpc_task *task)
619 task->tk_action = NULL;
620 if (task->tk_ops->rpc_call_done != NULL) {
621 task->tk_ops->rpc_call_done(task, task->tk_calldata);
622 if (task->tk_action != NULL) {
623 WARN_ON(RPC_ASSASSINATED(task));
624 /* Always release the RPC slot and buffer memory */
626 rpc_reset_task_statistics(task);
631 void rpc_exit(struct rpc_task *task, int status)
633 task->tk_status = status;
634 task->tk_action = rpc_exit_task;
635 if (RPC_IS_QUEUED(task))
636 rpc_wake_up_queued_task(task->tk_waitqueue, task);
638 EXPORT_SYMBOL_GPL(rpc_exit);
640 void rpc_release_calldata(const struct rpc_call_ops *ops, void *calldata)
642 if (ops->rpc_release != NULL)
643 ops->rpc_release(calldata);
647 * This is the RPC `scheduler' (or rather, the finite state machine).
649 static void __rpc_execute(struct rpc_task *task)
651 struct rpc_wait_queue *queue;
652 int task_is_async = RPC_IS_ASYNC(task);
655 dprintk("RPC: %5u __rpc_execute flags=0x%x\n",
656 task->tk_pid, task->tk_flags);
658 BUG_ON(RPC_IS_QUEUED(task));
661 void (*do_action)(struct rpc_task *);
664 * Execute any pending callback first.
666 do_action = task->tk_callback;
667 task->tk_callback = NULL;
668 if (do_action == NULL) {
670 * Perform the next FSM step.
671 * tk_action may be NULL if the task has been killed.
672 * In particular, note that rpc_killall_tasks may
673 * do this at any time, so beware when dereferencing.
675 do_action = task->tk_action;
676 if (do_action == NULL)
682 * Lockless check for whether task is sleeping or not.
684 if (!RPC_IS_QUEUED(task))
687 * The queue->lock protects against races with
688 * rpc_make_runnable().
690 * Note that once we clear RPC_TASK_RUNNING on an asynchronous
691 * rpc_task, rpc_make_runnable() can assign it to a
692 * different workqueue. We therefore cannot assume that the
693 * rpc_task pointer may still be dereferenced.
695 queue = task->tk_waitqueue;
696 spin_lock_bh(&queue->lock);
697 if (!RPC_IS_QUEUED(task)) {
698 spin_unlock_bh(&queue->lock);
701 rpc_clear_running(task);
702 spin_unlock_bh(&queue->lock);
706 /* sync task: sleep here */
707 dprintk("RPC: %5u sync task going to sleep\n", task->tk_pid);
708 status = out_of_line_wait_on_bit(&task->tk_runstate,
709 RPC_TASK_QUEUED, rpc_wait_bit_killable,
711 if (status == -ERESTARTSYS) {
713 * When a sync task receives a signal, it exits with
714 * -ERESTARTSYS. In order to catch any callbacks that
715 * clean up after sleeping on some queue, we don't
716 * break the loop here, but go around once more.
718 dprintk("RPC: %5u got signal\n", task->tk_pid);
719 task->tk_flags |= RPC_TASK_KILLED;
720 rpc_exit(task, -ERESTARTSYS);
722 rpc_set_running(task);
723 dprintk("RPC: %5u sync task resuming\n", task->tk_pid);
726 dprintk("RPC: %5u return %d, status %d\n", task->tk_pid, status,
728 /* Release all resources associated with the task */
729 rpc_release_task(task);
733 * User-visible entry point to the scheduler.
735 * This may be called recursively if e.g. an async NFS task updates
736 * the attributes and finds that dirty pages must be flushed.
737 * NOTE: Upon exit of this function the task is guaranteed to be
738 * released. In particular note that tk_release() will have
739 * been called, so your task memory may have been freed.
741 void rpc_execute(struct rpc_task *task)
743 rpc_set_active(task);
744 rpc_make_runnable(task);
745 if (!RPC_IS_ASYNC(task))
749 static void rpc_async_schedule(struct work_struct *work)
751 __rpc_execute(container_of(work, struct rpc_task, u.tk_work));
755 * rpc_malloc - allocate an RPC buffer
756 * @task: RPC task that will use this buffer
757 * @size: requested byte size
759 * To prevent rpciod from hanging, this allocator never sleeps,
760 * returning NULL if the request cannot be serviced immediately.
761 * The caller can arrange to sleep in a way that is safe for rpciod.
763 * Most requests are 'small' (under 2KiB) and can be serviced from a
764 * mempool, ensuring that NFS reads and writes can always proceed,
765 * and that there is good locality of reference for these buffers.
767 * In order to avoid memory starvation triggering more writebacks of
768 * NFS requests, we avoid using GFP_KERNEL.
770 void *rpc_malloc(struct rpc_task *task, size_t size)
772 struct rpc_buffer *buf;
773 gfp_t gfp = RPC_IS_SWAPPER(task) ? GFP_ATOMIC : GFP_NOWAIT;
775 size += sizeof(struct rpc_buffer);
776 if (size <= RPC_BUFFER_MAXSIZE)
777 buf = mempool_alloc(rpc_buffer_mempool, gfp);
779 buf = kmalloc(size, gfp);
785 dprintk("RPC: %5u allocated buffer of size %zu at %p\n",
786 task->tk_pid, size, buf);
789 EXPORT_SYMBOL_GPL(rpc_malloc);
792 * rpc_free - free buffer allocated via rpc_malloc
793 * @buffer: buffer to free
796 void rpc_free(void *buffer)
799 struct rpc_buffer *buf;
804 buf = container_of(buffer, struct rpc_buffer, data);
807 dprintk("RPC: freeing buffer of size %zu at %p\n",
810 if (size <= RPC_BUFFER_MAXSIZE)
811 mempool_free(buf, rpc_buffer_mempool);
815 EXPORT_SYMBOL_GPL(rpc_free);
818 * Creation and deletion of RPC task structures
820 static void rpc_init_task(struct rpc_task *task, const struct rpc_task_setup *task_setup_data)
822 memset(task, 0, sizeof(*task));
823 atomic_set(&task->tk_count, 1);
824 task->tk_flags = task_setup_data->flags;
825 task->tk_ops = task_setup_data->callback_ops;
826 task->tk_calldata = task_setup_data->callback_data;
827 INIT_LIST_HEAD(&task->tk_task);
829 task->tk_priority = task_setup_data->priority - RPC_PRIORITY_LOW;
830 task->tk_owner = current->tgid;
832 /* Initialize workqueue for async tasks */
833 task->tk_workqueue = task_setup_data->workqueue;
835 if (task->tk_ops->rpc_call_prepare != NULL)
836 task->tk_action = rpc_prepare_task;
838 rpc_init_task_statistics(task);
840 dprintk("RPC: new task initialized, procpid %u\n",
841 task_pid_nr(current));
844 static struct rpc_task *
847 return (struct rpc_task *)mempool_alloc(rpc_task_mempool, GFP_NOFS);
851 * Create a new task for the specified client.
853 struct rpc_task *rpc_new_task(const struct rpc_task_setup *setup_data)
855 struct rpc_task *task = setup_data->task;
856 unsigned short flags = 0;
859 task = rpc_alloc_task();
861 rpc_release_calldata(setup_data->callback_ops,
862 setup_data->callback_data);
863 return ERR_PTR(-ENOMEM);
865 flags = RPC_TASK_DYNAMIC;
868 rpc_init_task(task, setup_data);
869 task->tk_flags |= flags;
870 dprintk("RPC: allocated task %p\n", task);
874 static void rpc_free_task(struct rpc_task *task)
876 const struct rpc_call_ops *tk_ops = task->tk_ops;
877 void *calldata = task->tk_calldata;
879 if (task->tk_flags & RPC_TASK_DYNAMIC) {
880 dprintk("RPC: %5u freeing task\n", task->tk_pid);
881 mempool_free(task, rpc_task_mempool);
883 rpc_release_calldata(tk_ops, calldata);
886 static void rpc_async_release(struct work_struct *work)
888 rpc_free_task(container_of(work, struct rpc_task, u.tk_work));
891 static void rpc_release_resources_task(struct rpc_task *task)
895 if (task->tk_msg.rpc_cred) {
896 put_rpccred(task->tk_msg.rpc_cred);
897 task->tk_msg.rpc_cred = NULL;
899 rpc_task_release_client(task);
902 static void rpc_final_put_task(struct rpc_task *task,
903 struct workqueue_struct *q)
906 INIT_WORK(&task->u.tk_work, rpc_async_release);
907 queue_work(q, &task->u.tk_work);
912 static void rpc_do_put_task(struct rpc_task *task, struct workqueue_struct *q)
914 if (atomic_dec_and_test(&task->tk_count)) {
915 rpc_release_resources_task(task);
916 rpc_final_put_task(task, q);
920 void rpc_put_task(struct rpc_task *task)
922 rpc_do_put_task(task, NULL);
924 EXPORT_SYMBOL_GPL(rpc_put_task);
926 void rpc_put_task_async(struct rpc_task *task)
928 rpc_do_put_task(task, task->tk_workqueue);
930 EXPORT_SYMBOL_GPL(rpc_put_task_async);
932 static void rpc_release_task(struct rpc_task *task)
934 dprintk("RPC: %5u release task\n", task->tk_pid);
936 BUG_ON (RPC_IS_QUEUED(task));
938 rpc_release_resources_task(task);
941 * Note: at this point we have been removed from rpc_clnt->cl_tasks,
942 * so it should be safe to use task->tk_count as a test for whether
943 * or not any other processes still hold references to our rpc_task.
945 if (atomic_read(&task->tk_count) != 1 + !RPC_IS_ASYNC(task)) {
946 /* Wake up anyone who may be waiting for task completion */
947 if (!rpc_complete_task(task))
950 if (!atomic_dec_and_test(&task->tk_count))
953 rpc_final_put_task(task, task->tk_workqueue);
958 return try_module_get(THIS_MODULE) ? 0 : -EINVAL;
961 void rpciod_down(void)
963 module_put(THIS_MODULE);
967 * Start up the rpciod workqueue.
969 static int rpciod_start(void)
971 struct workqueue_struct *wq;
974 * Create the rpciod thread and wait for it to start.
976 dprintk("RPC: creating workqueue rpciod\n");
977 wq = alloc_workqueue("rpciod", WQ_MEM_RECLAIM, 0);
978 rpciod_workqueue = wq;
979 return rpciod_workqueue != NULL;
982 static void rpciod_stop(void)
984 struct workqueue_struct *wq = NULL;
986 if (rpciod_workqueue == NULL)
988 dprintk("RPC: destroying workqueue rpciod\n");
990 wq = rpciod_workqueue;
991 rpciod_workqueue = NULL;
992 destroy_workqueue(wq);
996 rpc_destroy_mempool(void)
999 if (rpc_buffer_mempool)
1000 mempool_destroy(rpc_buffer_mempool);
1001 if (rpc_task_mempool)
1002 mempool_destroy(rpc_task_mempool);
1004 kmem_cache_destroy(rpc_task_slabp);
1005 if (rpc_buffer_slabp)
1006 kmem_cache_destroy(rpc_buffer_slabp);
1007 rpc_destroy_wait_queue(&delay_queue);
1011 rpc_init_mempool(void)
1014 * The following is not strictly a mempool initialisation,
1015 * but there is no harm in doing it here
1017 rpc_init_wait_queue(&delay_queue, "delayq");
1018 if (!rpciod_start())
1021 rpc_task_slabp = kmem_cache_create("rpc_tasks",
1022 sizeof(struct rpc_task),
1023 0, SLAB_HWCACHE_ALIGN,
1025 if (!rpc_task_slabp)
1027 rpc_buffer_slabp = kmem_cache_create("rpc_buffers",
1029 0, SLAB_HWCACHE_ALIGN,
1031 if (!rpc_buffer_slabp)
1033 rpc_task_mempool = mempool_create_slab_pool(RPC_TASK_POOLSIZE,
1035 if (!rpc_task_mempool)
1037 rpc_buffer_mempool = mempool_create_slab_pool(RPC_BUFFER_POOLSIZE,
1039 if (!rpc_buffer_mempool)
1043 rpc_destroy_mempool();